Allentown, Pennsylvania Weather Conditions

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Current Conditions

  • 48°
  • Overcast
  • Wind: North 6 mph
  • Humidity: 58%
  • Visibility: 10.0 miles
  • Dew Point: 34°
  • Pressure: 29.99 in. -

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Forecast data from the National Digital Forecast Database.

5 Day Forecast

  • Monday
  • Chance of Rain
  • High: 68 °
  • Low: 43 °
  • Chance of Rain
  • Tuesday
  • Partly Cloudy
  • High: 50 °
  • Low: 36 °
  • Partly Cloudy
  • Wednesday
  • Chance of Snow
  • High: 39 °
  • Low: 28 °
  • Chance of Snow
  • Thursday
  • Partly Cloudy
  • High: 39 °
  • Low: 19 °
  • Partly Cloudy
  • Friday
  • Clear
  • High: 36 °
  • Low: 27 °
  • Clear

Forecast for Allentown, Pennsylvania

Updated: 4:00 PM EST on November 23, 2014

  • Sunday

    Overcast in the morning, then partly cloudy. High of 54F. Winds less than 5 mph.

  • Sunday Night

    Overcast with a chance of rain, then rain after midnight. Low of 43F. Winds from the SE at 5 to 15 mph. Chance of rain 100% with rainfall amounts near 0.7 in. possible.

  • Monday

    Overcast with a chance of rain. High of 68F. Breezy. Winds from the SSW at 10 to 20 mph. Chance of rain 60%.

  • Monday Night

    Partly cloudy with a chance of rain. Low of 43F. Winds from the WSW at 10 to 15 mph. Chance of rain 20%.

  • Tuesday

    Clear in the morning, then overcast. High of 50F. Winds from the West at 10 to 15 mph.

  • Tuesday Night

    Partly cloudy in the evening, then overcast. Low of 36F. Winds from the WNW at 5 to 10 mph.

  • Wednesday

    Overcast with a chance of snow and rain showers in the afternoon. Fog early. High of 39F. Winds from the NNE at 5 to 10 mph. Chance of snow 60% with accumulations up to 2 in. possible.

  • Wednesday Night

    Overcast with a chance of snow in the evening, then partly cloudy with a chance of snow. Low of 28F with a windchill as low as 21F. Winds from the NW at 5 to 15 mph. Chance of snow 50% with accumulations up to 1 in. possible.

  • Thursday

    Overcast in the morning, then mostly cloudy. High of 39F with a windchill as low as 25F. Winds from the West at 5 to 10 mph.

  • Thursday Night

    Partly cloudy. Low of 19F. Winds from the WNW at 10 to 15 mph.

  • Friday

    Clear. High of 36F with a windchill as low as 9F. Winds from the NW at 10 to 15 mph.

  • Friday Night

    Partly cloudy. Low of 27F. Winds less than 5 mph.

  • Saturday

    Mostly cloudy. High of 43F. Winds from the SSW at 10 to 15 mph.

  • Saturday Night

    Partly cloudy. Fog overnight. Low of 32F with a windchill as low as 25F. Winds from the SW at 5 to 15 mph.

  • Sunday

    Partly cloudy. High of 45F. Winds from the NW at 10 to 15 mph.

  • Sunday Night

    Partly cloudy. Low of 34F. Winds less than 5 mph.

  • Monday

    Mostly cloudy with a chance of rain. High of 63F. Winds less than 5 mph. Chance of rain 20%.

  • Monday Night

    Mostly cloudy. Low of 36F. Winds less than 5 mph.

  • Tuesday

    Partly cloudy. High of 46F. Winds less than 5 mph.

  • Tuesday Night

    Partly cloudy with a chance of rain. Low of 36F. Winds less than 5 mph. Chance of rain 40%.

  • Wednesday

    Mostly cloudy with a chance of rain. High of 46F. Winds less than 5 mph. Chance of rain 50%.

  • Wednesday Night

    Overcast with a chance of rain. Low of 36F. Winds less than 5 mph. Chance of rain 50%.

  • Thursday

    Clear with a chance of rain. High of 45F. Winds less than 5 mph. Chance of rain 30%.

  • Thursday Night

    Clear. Fog overnight. Low of 36F. Winds from the SSW at 10 to 15 mph.

Personal Weather Stations

Personal Weather Stations [Add your weather station!]

Location: South Filmore Street, Allentown, PA

Updated: 10:17 PM EST

Temperature: 48.6 °F Dew Point: 38 °F Humidity: 68% Wind: SE at 5.3 mph Pressure: 29.95 in Hourly Precipitation: - Windchill: 46 °F Graphs

Location: Park Ridge, Allentown, PA

Updated: 10:30 PM EST

Temperature: 49.1 °F Dew Point: 38 °F Humidity: 65% Wind: Calm Pressure: 29.77 in Hourly Precipitation: 0.00 in Windchill: 49 °F Graphs

Location: Whitehall, Whitehall, PA

Updated: 10:30 PM EST

Temperature: 48.4 °F Dew Point: 37 °F Humidity: 65% Wind: Calm Pressure: 29.60 in Hourly Precipitation: 0.00 in Windchill: 48 °F Graphs

Location: Hokendauqua, Whitehall, PA

Updated: 10:32 PM EST

Temperature: 47.3 °F Dew Point: 37 °F Humidity: 67% Wind: Calm Pressure: 29.96 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: Fountain Hill - Near ST Lukes hosp., Fountain Hill, PA

Updated: 10:31 PM EST

Temperature: 49.8 °F Dew Point: 41 °F Humidity: 71% Wind: NW at 6.0 mph Pressure: 30.00 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: Lower Saucon Township, Bethlehem, PA

Updated: 10:32 PM EST

Temperature: 45.7 °F Dew Point: 27 °F Humidity: 48% Wind: Calm Pressure: 30.20 in Hourly Precipitation: 0.00 in Windchill: 46 °F Graphs

Location: West Bethlehem, Bethlehem, PA

Updated: 10:31 PM EST

Temperature: 48.9 °F Dew Point: 40 °F Humidity: 72% Wind: ESE at 4.2 mph Pressure: 29.99 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: Emmaus, Emmaus, PA

Updated: 10:18 PM EST

Temperature: 49.5 °F Dew Point: 40 °F Humidity: 69% Wind: SW at 1.1 mph Pressure: 29.86 in Hourly Precipitation: - Windchill: 50 °F Graphs

Location: Harvest Fields, East Texas, Allentown, PA

Updated: 10:24 PM EST

Temperature: 48.6 °F Dew Point: 39 °F Humidity: 69% Wind: East at 2.7 mph Pressure: 29.94 in Hourly Precipitation: - Windchill: 49 °F Graphs

Location: Werner Ent. Allentown, Allentown, PA

Updated: 10:31 PM EST

Temperature: 47.7 °F Dew Point: 37 °F Humidity: 66% Wind: NNE at 1.0 mph Pressure: 29.95 in Hourly Precipitation: 0.00 in Windchill: 48 °F Graphs

Location: South Mountain Drive, Emmaus, PA

Updated: 10:26 PM EST

Temperature: 46.0 °F Dew Point: 38 °F Humidity: 73% Wind: North at - Pressure: 29.70 in Hourly Precipitation: - Windchill: 46 °F Graphs

Location: upper saucon township, Coopersburg, PA

Updated: 10:30 PM EST

Temperature: 46.8 °F Dew Point: 38 °F Humidity: 70% Wind: Calm Pressure: 30.01 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: Gwenmawr Road, Bethlehem, PA

Updated: 10:27 PM EST

Temperature: 45.9 °F Dew Point: 31 °F Humidity: 55% Wind: North at - Pressure: 30.07 in Hourly Precipitation: - Windchill: 46 °F Graphs

Location: West Allentown, Wescosville, PA

Updated: 10:30 PM EST

Temperature: 48.2 °F Dew Point: 41 °F Humidity: 76% Wind: ESE at 1.0 mph Pressure: 29.98 in Hourly Precipitation: 0.00 in Windchill: 48 °F Graphs

Location: Upper Macungie Twp, Allentown, PA

Updated: 10:24 PM EST

Temperature: 48.6 °F Dew Point: 39 °F Humidity: 69% Wind: ESE at 3.7 mph Pressure: 29.87 in Hourly Precipitation: - Windchill: 47 °F Graphs

Location: Windermerre Park, Allentown, PA

Updated: 10:29 PM EST

Temperature: 47.1 °F Dew Point: 35 °F Humidity: 62% Wind: Calm Pressure: 29.89 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: Schnecksville, PA

Updated: 10:30 PM EST

Temperature: 46.7 °F Dew Point: 35 °F Humidity: 64% Wind: ESE at 1.0 mph Pressure: 29.99 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: Macungie Area Weather, Macungie, PA

Updated: 10:32 PM EST

Temperature: 48.3 °F Dew Point: 40 °F Humidity: 74% Wind: SE at 2.8 mph Pressure: 29.97 in Hourly Precipitation: 0.00 in Windchill: 48 °F Graphs

Location: Blue Church Road South, Coopersburg, PA

Updated: 10:26 PM EST

Temperature: 45.5 °F Dew Point: 31 °F Humidity: 56% Wind: North at - Pressure: 30.07 in Hourly Precipitation: - Windchill: 46 °F Graphs

Location: Air Products Campus Wx, Allentown, PA

Updated: 10:31 PM EST

Temperature: 48.3 °F Dew Point: 39 °F Humidity: 71% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Windchill: 48 °F Graphs

Location: Strawberry Acres, Coplay, PA

Updated: 10:30 PM EST

Temperature: 46.2 °F Dew Point: 35 °F Humidity: 65% Wind: ENE at 1.0 mph Pressure: 29.87 in Hourly Precipitation: 0.00 in Windchill: 46 °F Graphs

Location: whispering hollow south, Northampton, PA

Updated: 10:32 PM EST

Temperature: 48.0 °F Dew Point: 5 °F Humidity: 17% Wind: East at 6.0 mph Pressure: 29.19 in Hourly Precipitation: 0.00 in Windchill: 45 °F Graphs

Location: Bethlehem Township, Bethlehem, PA

Updated: 10:31 PM EST

Temperature: 48.7 °F Dew Point: 39 °F Humidity: 70% Wind: Calm Pressure: 30.01 in Hourly Precipitation: 0.00 in Windchill: 49 °F Graphs

Location: Wassergass, Hellertown, PA

Updated: 10:32 PM EST

Temperature: 47.9 °F Dew Point: 41 °F Humidity: 78% Wind: Calm Pressure: 29.96 in Hourly Precipitation: 0.00 in Windchill: 48 °F Graphs

Location: Fogelsville, PA

Updated: 10:32 PM EST

Temperature: 43.6 °F Dew Point: 33 °F Humidity: 65% Wind: Calm Pressure: 29.73 in Hourly Precipitation: 0.00 in Windchill: 44 °F Graphs

Location: Jamesville, Bath, PA

Updated: 10:19 PM EST

Temperature: 46.0 °F Dew Point: 35 °F Humidity: 66% Wind: ESE at 1.6 mph Pressure: 29.80 in Hourly Precipitation: - Windchill: 46 °F Graphs

Location: Pointe West, Fogelsville, PA

Updated: 10:32 PM EST

Temperature: 47.1 °F Dew Point: 31 °F Humidity: 54% Wind: Calm Pressure: 29.89 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: The Vineyard, Easton, PA

Updated: 10:31 PM EST

Temperature: 48.8 °F Dew Point: 40 °F Humidity: 71% Wind: NNW at 1.0 mph Pressure: 29.86 in Hourly Precipitation: 0.00 in Windchill: 49 °F Graphs

Location: Upper Milford Twsp, Zionsville, PA

Updated: 10:30 PM EST

Temperature: 44.6 °F Dew Point: 38 °F Humidity: 78% Wind: Calm Pressure: 30.01 in Hourly Precipitation: 0.00 in Windchill: 45 °F Graphs

Location: Breinigsville / Lower Macungie, Mertztown, PA

Updated: 10:31 PM EST

Temperature: 50.2 °F Dew Point: 41 °F Humidity: 70% Wind: ESE at 1.0 mph Pressure: 29.95 in Hourly Precipitation: 0.00 in Windchill: - Graphs

Location: Kefallonia Drive, Hellertown, PA

Updated: 10:23 PM EST

Temperature: 44.1 °F Dew Point: 38 °F Humidity: 79% Wind: Calm Pressure: 29.90 in Hourly Precipitation: - Windchill: 44 °F Graphs

Location: Springtown, PA, Springtown, PA

Updated: 10:31 PM EST

Temperature: 47.3 °F Dew Point: 39 °F Humidity: 72% Wind: Calm Pressure: 30.02 in Hourly Precipitation: 0.00 in Windchill: 47 °F Graphs

Location: Washington Township, N3DL, Slatington, PA

Updated: 10:31 PM EST

Temperature: 47.7 °F Dew Point: 36 °F Humidity: 65% Wind: Calm Pressure: 29.96 in Hourly Precipitation: 0.00 in Windchill: 48 °F Graphs

Location: Eagles Landing, Nazareth, PA

Updated: 10:32 PM EST

Temperature: 47.0 °F Dew Point: 32 °F Humidity: 56% Wind: SSW at 3.1 mph Pressure: 29.56 in Hourly Precipitation: 0.00 in Windchill: 46 °F Graphs

Location: Saratoga Chase, Breinigsville, PA

Updated: 10:27 PM EST

Temperature: 48.8 °F Dew Point: 41 °F Humidity: 75% Wind: ESE at 1.0 mph Pressure: 29.97 in Hourly Precipitation: 0.00 in Windchill: 49 °F Graphs

Location: Bath, PA

Updated: 10:32 PM EST

Temperature: 46.5 °F Dew Point: 38 °F Humidity: 71% Wind: Calm Pressure: 29.98 in Hourly Precipitation: 0.00 in Windchill: 46 °F Graphs

MSN Maps of:

Temp: Dew Point: Humidity Wind Pressure Hr Precip -

NWS Forecaster Discussion




Area forecast discussion 
National Weather Service Mount Holly New Jersey 
928 PM EST sun Nov 23 2014 


Synopsis... 
intensifying low pressure in Missouri will arrive in the upper Great 
Lakes Monday yanking a strong warm front north through our region 
early Monday. It then sweeps a cold front off the East Coast Monday 
night. High pressure follows late Tuesday. A coastal storm forming 
off the North Carolina coast Wednesday morning moves east of New 
England by Thanksgiving. A cold front passes through our area 
Thursday evening and dry high pressure moves to the Carolinas next 
weekend. 


&& 


Near term /until 6 am Monday morning/... 
not much change needed with the update this evening, just slowed 
the timing of the probability of precipitation a bit with plenty of dry air still in place. 
Starting to see some over-running rain across southern Delaware-Maryland-Virginia 
while the heaviest rain remains well to our south and west. 


Otherwise, a potent synoptic setup will evolve through tonight. 
This involves a large upper-level trough that will amplify from 
the Midwest to the Gulf Coast states, which drives a deepening 
surface low into the central Great Lakes overnight. Meanwhile, a 
building ridge near the East Coast will shift offshore with its 
center mainly east of Florida. 


The strengthening of the upper-level trough to our west tonight is a 
result of a potent 250 mb jet carving it out. As this occurs, the 
height fields tighten quite a bit especially on the east and south 
side of the trough. This will drive an increasingly robust wind 
field across our area during the course of tonight. As this occurs, 
short wave energy in combination with strengthening warm air advection will drive 
increasing large scale ascent across our area. As a result, about a 
4-6 hour period of rain is expected to surge from southwest to 
northeast across the entire area during the night. As the Theta-E 
advection really ramps up this evening, the low-level dew points 
will be on the increase and this will lead to a jump in precipitable water values. 
Therefore, some of the rain will be moderate to heavy at times which 
could lead to localized poor drainage flooding. We therefore 
continued to rapidly increase the probability of precipitation from south to north this 
evening with categorical probability of precipitation everywhere overnight. There is some 
elevated instability forecast to arrive across our southeastern 
zones especially late, and this could produce a few isolated 
embedded thunderstorms. 


As the flow increases above the surface and the injection of a warm 
airmass works in across the area, we should start to mix better 
overnight especially near and east of Interstate 95 and in the 
higher terrain. This along with warm air advection will allow temperatures to warm 
across the entire area as a warm front lifts northward across our 
County Warning Area. As a result, we continued to indicate rising temperatures 
through the overnight. By daybreak, some east and southern areas may 
be into the lower 60s. The forecast soundings indicate better 
momentum Transfer developing late especially the farther southeast 
one GOES across the area, however given the warm air advection pattern there should 
be a decent inversion present during the night even with the 
boundary layer warming. As a result, the depth of the mixed layer 
should not allow the Transfer of the rather robust winds with the 
low-level jet down to the surface. There is a chance some fog develops 
late especially as the warmer and more moist air surges in. 


As for low temperatures, mostly a NAM/GFS MOS blend was used and 
these were set to occur this evening. As mentioned above, a 
temperature rise was then indicated through the night. 


&& 


Short term /6 am Monday morning through 6 PM Monday/... 
record warmth certainly possible Monday afternoon across the area. 


A sharp upper-level trough is forecast to be to our west, and this 
will drive a potent surface low across the Great Lakes and toward 
Hudson Bay. This places our area within the warm sector and 
southwesterly flow to its east. The main low-level jet and large 
scale lift and associated warm frontal forcing is forecast to 
quickly shift to our northeast during the morning. As this occurs, a 
dry slot overspreads our area. This will result in rain tapering to 
some showers and ending fairly quickly in the morning from southwest 
to northeast. Therefore, the probability of precipitation decrease rather quickly during the 
morning. There could be some low clouds and fog hanging on for a 
little while across the northern areas and along the coast, however 
confidence is low on this. After that, the forecast soundings 
indicate that drying occurs aloft first associated with the dry 
slot, however with our area being within the warm sector and still 
strong winds above the surface we should mix out much of the lower 
clouds. While a few showers could be around during the late morning 
and afternoon, the soundings generally show a middle level cap 
developing along with the drying. Therefore, this may limit any 
shower development for awhile despite some instability present. This 
brings US to the warmth and winds. 


The temperatures at 925 mb are forecast to be around +15c during the 
afternoon. The forecast soundings indicate that as we lose the lower 
clouds and the boundary layer warms, mixing will deepen. This will 
boost high temperatures into the 70s across much of the area. If we 
clear out more, then temperatures could be a few degrees higher than 
currently forecast. For now, used a MOS blend but did adjust up some 
especially for the Interstate 95 area on south and east. 


As for the surface winds Monday, while the intense low-level jet is 
forecast to be shifting to our northeast during the day, the wind 
field at 925 mb is forecast to be in the 40-50 knot range. The 
forecast soundings show better mixing becoming established and if we 
warm the boundary even more this depth would increase some. It still 
appears though that we do not mix up fully to the strongest winds, 
and therefore we carry gusts below advisory criteria. We did lean 
closer to the GFS winds which are a little stronger at the surface 
and boosted the gusts up to 35 miles per hour. 


&& 


Long term /Monday night through Sunday/... 
**winter storm-event vicinity I-95 corridor westward wednesday** 


500mb: the strong short wave associated with the Great Lakes storm 
lifts northeastward into Quebec Monday night. The next trough is on a more 
southerly Route and crosses the East Coast late Wednesday night 
with more coherence in ensemble solutions than presented 24 hours 
ago. Heights rise toward next weekend but a general cyclonic flow 
continues across North America with embedded short waves difficult 
to discern in the ensemble mean. 


Temperatures: temperatures for the month of November have so far 
averaged 4 to 5 degrees below normal with yesterday the 10th 
consecutive day of below normal temperatures. A brief hiatus from 
the cold is at hand but even so...the month as a whole projects to 
average well below normal. Did a quick extrapolation of maximum/min 
for the rest of the month based our office forecast and we are 
projecting 2.5 to 3.5 degrees below the monthly average of 47.6 degrees. 


Calendar day averages Tuesday should be around 5 to 10 degrees above 
normal (1201am Tuesday morning highs could be 60-63f phl eastward), 
slightly below normal Wednesday with maximum temperatures on Wednesday 6 
to 14 degrees below normal depending when the precipitation begins. Thursday 
through Saturday calendar day average temperatures should average 
below normal and next Sunday in may warm more than we have forecast. 


Forecast basis: unless otherwise noted the long term period of this 
forecast is generally based on a 50 50 blend of the 12z/23 NAM/GFS 
MOS for the period Monday night-Tuesday night. Then the 12z/23 GFS 
MOS was not applied Wednesday...it looks too warm by 3 to 5 degrees). 
Thereafter (thursday onward) the 1522z/23 wpc gridded guidance 
was used straight up. All this is eventually checked against the 
12z/23 European model (ecmwf) through Thursday to see if we're in the ballpark 
with European model (ecmwf) cyclically persistent 18z 2 meter temperatures. 
Precipitation probability guidance is checked against the 09z/23 
sref 3hrly probability of precipitation for .01 through 00z Thursday. The sref also has 
significant probabilities for 1 and 4 inch snowfall amounts by 7pm 
Wednesday i95 corridor westward but could be biased too cold! The 
12z/23 gefs 6hr probability of precipitation for 0.05 are used after 00z/Thursday as a 
check against other available guidance. 


The dailies... 


Monday night...small chance of a low top shower or sprinkle. 
Otherwise clearing and maybe a bit breezy (west wind gusts 20 miles per hour 
for a time) after the evening cold front passage when we see the boundary layer 
wind forecast increases around 03-06z. Still above average temperatures for 
this time of year...especially during the evening when temperatures will 
be in the 60s. Guidance temps: used the warmer of the available temperature 
guidance and blended with the even warmer 2m NAM temperatures at 00z and 
03z/25 (prior to cfp). 


Tuesday...partly to mostly sunny and breezy (first cirrus from Gulf 
Coast short wave moving eastward vicinity tex/la and also rrq strong 
250mb jet of 200 knots /230 miles per hour/ near l ontario). For the surface...am 
expecting westerly wind gusts 25 miles per hour. 


Tuesday night...becoming cloudy with light wind. Seasonable temperatures. 
Light rain spreads up onto the Delaware-Maryland-Virginia and possibly all the way 
to phl by 12z Tuesday. 




Wednesday-Wednesday night...our model of choice leans heavily on the 
European model (ecmwf) with GFS wpc and sref mix. A coastal storm deepens a mb per 
hour as it races northeastward east of the middle Atlantic coast. Low pressure 
development aided by rrq of 200kt 250mb jet over the Gulf of St 
Lawrence. 


One quarter to 1.25 inch amounts expected...heaviest probably in New Jersey. 


Snow map posted along with briefing package to give our first 
effort at snow accumulations Wednesday and Wednesday night. 
There will be adjustments. Thinking that this forecast can 
easily be in error 3 inches either side of what is posted on our 
web site this Sunday afternoon. 


Confidence on snow amounts reaching the posted values is highest 
from reading PA through the Poconos into far northwest New Jersey. Confidence 
lessens southeastward. 


No matter...there is a high probability of snow impacting travel 
sometime Wednesday or Wednesday night...especially just west of 
I-95. The 12z/23 European model (ecmwf) is the warmest model with the GFS colder 
but also probably too far east. The ec has a definite above 
freezing layer between 850 and 700mb. The GFS not. 


Snow/rain: I-95 corridor or 30 miles northwest looks to be general 
demarcation between mostly snow and mostly rain. Depending on your 
model selected and there will be adjustments needed...it could be 
rain-snow changing to all rain then ending as snow for i95; mostly 
snow further west and north through eastern PA and northwest New Jersey. 
Elevations will accumulate best where its colder. 


Temperatures for the Wednesday forecast are the 330 am phi forecast blended 50 50 
with the 00z-12z/23 European model (ecmwf) 2m temperatures and did not use the 12z/23 mexmos 
temperatures which looked 3 to 6 degrees too warm. Maximum temperatures appear to be 
occurring forenoon before precipitation wet bulbs colder readings during the 
afternoon. 


Temperatures for Wednesday night are at or just above the 12z/23 GFS mexmos 
values and slightly warmer than the wpc temperatures. 


Those looking at the models should be aware that guidance does not 
handle snow cooling the surface temperatures and the column will be cold 
enough for all snow not too far west of phl with only the lowest 
1000 feet air temperature structure determining the surface ptype. 


The larger accums for this event along I-95 may be reserved for the 
evening as precipitation probably changes to all snow. 


Southeast of i95...which includes most of Maryland East Shore and Delaware and 
coastal New Jersey...mainly rain is expected. It could end as a period of 
wet snow or flurries... all dependent on banding tail (500 mb vorticity 
maximum track/strength). 


Thursday...a secondary trough passage...surface cold front with 
instability and moisture (windex?) May be accompanied by snow 
showers northwest of i95. For now only gridded in the Poconos. 


Friday- Sunday...wpc guidance and high pressure slides to the 
Carolinas. Lows temperatures Friday and Saturday morning might be around 
8 degrees colder than forecast north of i78 if there is snow 
cover (10 to 15f). 


&& 


Aviation /02z Monday through Friday/... 
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg, 
kmiv, kacy and surrounding areas. 


Very little change in the current thinking/timing with the 00z 
tafs, though a delayed onset of MVFR is possible by an hour or two 
from south to north. 


Tonight...VFR to start, then ceilings are expected to quickly 
lower to MVFR and IFR /local LIFR/ as a warm front arrives. A 
period of rain is expected to move through, some of which could be 
heavy at times. This will also reduce the visibilities, with even 
some fog possible late especially toward the coast and from near 
kabe on northward. South to southeast winds at around 5 knots will 
increase to near 15 knots overnight and could become gusty at 
times. The strongest winds should be from near the kphl metropolitan on 
south and east. The amount of gustiness that occurs late carries 
lower confidence. An isolated thunderstorm cannot be ruled out 
late mainly south and east of kphl. A potent low-level jet moves 
across the area, and therefore low-level wind shear is included 
for the overnight. 


Monday...MVFR/IFR /local LIFR/ ceilings for a time in the morning, 
then ceilings should rise to VFR in the afternoon as a much warmer 
airmass is in place. It is possible though that some low clouds 
linger longer especially closer to the coast and north of kttn and 
kabe. Rain departs early, however a few showers through the day will 
be possible. Southwesterly winds increase to 15-20 knots with gusts 
up to 30 knots. The core of low-level jet shifts farther offshore 
during the day, therefore low-level wind shear should decrease 
during the morning. 


Outlook... 
Monday night-Tuesday night...mainly VFR. Westerly winds may briefly 
gust 20-25 knots Monday night subsequent to a cold front passage that could be 
accompanied by a sprinkle. West winds should gust 25 knots on Tuesday 
then diminish considerably late Tuesday night as they turn north 
to northwest. High confidence on this scenario. 


Wednesday...a coastal storm will bring MVFR or IFR conditions in 
rain coast (kacy/kmiv), rain snow kttn kpne ktphl and kilg and 
mostly snow kabe and krdg. In addition, expect persistent northerly 
or northeasterly winds for generally the latter half of the day 
with gusts 12-25 knots from west to east. Precipitation should end as 
snow most taf sites at night except possibly not at kmiv/kacy. 


Significant pavement accumulations possible krdg/kabe especially 
Wednesday evening. 


Thanksgiving...conditions slowly return to VFR and winds shift to 
westerly or northwest. There could be brief MVFR conds in scattered 
snow showers later Thursday mainly just north of krdg and kabe. Winds may 
gust to 25 knots. 


Friday...probably VFR. 


&& 


Marine... 
a potent storm system will track well to our west later tonight and 
Monday. This will drive a warm front north of the area tonight along 
with an increasingly robust wind field. The 925 mb winds are 
forecast to increase to 50-70 knots through the night, then decrease 
to about 40-50 knots on Monday. The forecast soundings indicate that 
better mixing occurs for awhile tonight before a much warmer airmass 
arrives late and during Monday. On Monday, the forecast soundings 
indicate that a very strong low-level inversion is present which 
would keep the stronger winds above the surface. Therefore, a Gale 
Warning remains in effect starting at midnight tonight for all our 
zones /lower confidence for upper Delaware Bay/ and continues 
through Monday morning. As we go through Monday, the best mixing 
should shift nearshore and over land. Therefore, we did not extend 
the Gale Warning at this time. The seas will build quite a bit during the 
night into Monday with strong southerly winds, although just how 
much wind actually makes it to the surface will influence the seas. 


Outlook... 
Monday night...SW wind shifting to west with the cold front passage. Small Craft Advisory likely. 


Tuesday...Small Craft Advisory expected during cold air advection on westerly flow. 


Tuesday night...probably below Small Craft Advisory conditions. 


Wednesday...strong northeast shifting to northwest Small Craft Advisory with a 
possible gale. Seas forecast on the Atlantic waters may be 2 
to 4 feet too low Wednesday afternoon and evening. 


Thanksgiving...winds are expected to eventually fall below Small Craft Advisory 
criteria but Atlantic seas may not drop below 5 feet until at night. 


Friday...possible Small Craft Advisory cold air advection west to northwest flow. 


&& 


Climate... 
for our eight climate sites, here are the record high temperatures 
for November 24th and the most recent year of occurrence. 


Record highs 11/24: 


Acy: 72 set in 1999 
phl: 71 set in 1979 
ilg: 73 set in 1979 
abe: 69 set in 1931 
ttn: 71 set in 1979 
ged: 75 set in 1992 
rdg: 69 set in 1979 
mpo: 64 set in 1931 


With the possibility of a midweek coastal storm bringing snow to the 
region, we have included daily snowfall records below for our four 
primary climate sites that have a long-standing unbroken period of 
record (por) with respect to historical snowfall data. 


Best chance of coming close to a "daily" record as of this Sunday 
afternoons collaboration appears to be kabe. 


Daily snowfall records: 


November 26th: November 27th: period of record: 


Acy: trace 1977,1957,1955 1.2 inches 1978 1874 


Phl: 6.0 inches 1898 6.9 inches 1949,1938 1872 


Ilg: 0.1 inches 1950 4.5 inches 1978 1894 


Abe: 1.7 inches 1925 7.0 inches 1938 1922 


&& 


Phi watches/warnings/advisories... 
PA...none. 
New Jersey...none. 
Delaware...none. 
Maryland...none. 
Marine...Gale Warning until 11 am EST Monday for anz430-431-450>455. 


&& 


$$ 
Synopsis...drag 
near term...gorse/Heavener 
short term...gorse/nierenberg 
long term...drag 
aviation...drag/gorse 
marine...drag/gorse 
climate...drag 












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