Severe Weather Alerts

Your Weather

To update your location please enter your ZIP code, city, state, airport code or country in the field below. Weather by E-mail: Forecast storm alerts. Weather E-Mail Alert Sign Up »

Next 12 Hours

Forecast data from the National Digital Forecast Database.

5 Day Forecast

• Friday
• 
• High: 64 °
• Low: 46 °
• Chance of T-Storms

• Saturday
• 
• High: 61 °
• Low: 45 °
• Chance of Rain

• Sunday
• 
• High: 68 °
• Low: 45 °
• Partly Cloudy

• Monday
• 
• High: 73 °
• Low: 46 °
• Clear

• Tuesday
• 
• High: 75 °
• Low: 55 °
• Partly Cloudy

Area forecast discussion 
National Weather Service Mount Holly New Jersey 
953 PM EDT Thursday may 23 2013 


Synopsis... 
a cold front will slowly cross the region tonight into Friday. A 
low pressure system will develop on the front off the New Jersey 
coast Friday and slowly move northeast reaching the Canadian 
Maritimes on Monday. High pressure will then build east in its 
wake early next week. A warm front is forecast to move through the 
forecast area on Tuesday into Wednesday. 


&& 


Near term /until 6 am Friday morning/... 
thunderstorms were into eastern PA, northwest New Jersey and the Maryland 
Eastern Shore late this evening. They were running ahead of the 
cold front that was expected to enter our far western zones by 
midnight. Surface based convective available potential energy were showing stable air advancing 
from the Atlantic to meet the activity somewhere around the 
Delaware valley. The main change (other than to make a Nowcast in 
the very near term grids) was to back off a bit on the 
strength/possibility of thunder as one moves into the eastern part 
of the forecast area and the Atlantic. For the western and perhaps 
the central part of the forecast area, the thunder, heavy rain 
and gusty winds still look on target. Temperatures were mainly 
left alone, except we had to nudge down the hourlies for a couple 
of hours along the coast thanks to the intrusion of stable air. 


&& 


Short term /6 am Friday morning through 6 PM Friday/... 
early Friday, a surface cold front is prognosticated to be just east of our 
forecast area, continuing to slowly progress offshore through the 
day. Meanwhile, a middle level low will be dropping south across the 
region through the course of the day, and we have kept chance to 
likely probability of precipitation for showers in place across the forecast area. Gusty 
northwest winds are expected to develop across the region through 
the day, with gusts reaching around 25 miles per hour. Cooler and drier air 
will be filtering in across the middle Atlantic, and maximum 
temperatures will be noticeably cooler than in recent days, with 
highs mainly from the lower 60s for our northwest areas to the 
middle and upper 60s in southern New Jersey and the Delaware-Maryland-Virginia. 


&& 


Long term /Friday night through Thursday/... 
low pressure will move slowly northeastward and away from the area 
Friday night into Saturday as an upper level trough is slow to exit. 
Unfortunately, this means that Saturday, which looked like a nice 
weather day earlier in the week doesn't look nearly as nice at this time. There 
will be showers overnight into Sat morning. Then, conds will slowly 
improve as the day progresses. However, there will still be an 
abundance of clouds and decent northwesterly flow until the low clears the 
area. The best chance of precipitation looks to be over northestern areas. 


High pressure will build down behind the departing low and this 
will keep a decent northwesterly flow Sat night into sun. However, overall 
conds will continue to improve and certainly by sun there will be 
more sunshine which will continue into Monday. 


The high will move eastward and off the CST by Tuesday as a warm front 
approaches and then passes through the region and then a strong ridge 
aloft begins to develop over the area. Probability of precipitation will be introduced to 
the forecast around Tuesday into Wednesday with the warm front. 


Temperatures will be much below normal Sat, in some cases 10 to 15 
degrees below normal....then temperatures rebound a bit on sun and Monday 
before rising to above normal values by Wednesday. 


&& 


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


We forecast thunder for the northwestern sites with some gusty 
winds (around 30 knots) late this evening. We forecast thunder 
through around midnight but do not play up the winds over the 
Delaware valley sites. We have kept the thunder out of the 
southeastern sites because of the stable air and low clouds that 
have moved in. If any thunder occurs there, it should be elevated. 
During the overnight hours, we expect ceilings to lower to IFR 
across much of the area. Winds will continue to be mainly out of 
the south until the cold front moves across the area, and then 
there should be a relatively placid shift in the winds to west. 


Friday...IFR conditions will likely begin the day, with improvement 
to MVFR expected by mid-morning. Winds will become northwesterly 
and then become rather gusty by middle-morning, with gusts in the 20 
to 30 knot range expected then through the afternoon to early 
evening. 




Outlook... 
Friday night through Sat...MVFR to possibly IFR conditions due to 
clouds and showers. Worst conditions expected at northeastern 
terminals and airports. Conditions could improve as Saturday 
continues. North to northwest wind gusts could exceed 20 kts. Low 
confidence on timing of improving conds. 


Sat night through Monday...mostly VFR. Some gusty northwest winds 
possible on Sunday. High confidence. 


Tuesday...mainly VFR. Lower ceilings/visibilities possible later in the day with warm 
front and rain. MDT confidence. 


&& 


Marine... 
with an approaching cold front nearing the region this evening and 
tonight, we maintain a Small Craft Advisory for our coastal waters, 
with wind gusts in the 20 to 25 knot range and seas around 5 feet. 
Following the cold front passage during Friday morning, winds will 
turn and become northwesterly for our waters through Friday. Wind 
gusts will pick up into the 25 to 30 knot range, with seas around 5 
to 6 feet for our coastal waters. In addition, we have raised a 
Small Craft Advisory for Delaware Bay starting 18z Friday, as wind 
gusts and seas are expected to reach criteria during Friday 
afternoon. 


Outlook... 
the Small Craft Advisory flag has been extended into Sat morning and may 
need to be extended further. Also, have expanded Small Craft Advisory to include 
del Bay. With the low off the coast and strong high pressure 
building in, there will be strengthening northwesterly flow through Sat seas 
will remain elevated and the wind will hit Small Craft Advisory as well. Some guidance 
is even indicating gale potential on Sat, but confidence is low 
enough on that at this time that no headlines were issued. After about 
Sunday morning. After no additional marine flags are anticipated 
through the period. 


&& 


Rip currents... 
we forecast a moderate risk of dangerous rip currents along the 
coast of New Jersey and Delaware on Friday. 


&& 


Phi watches/warnings/advisories... 
PA...none. 
New Jersey...none. 
Delaware...none. 
Maryland...none. 
Marine...Small Craft Advisory until 8 am EDT Saturday for anz450>455. 
Small Craft Advisory from 2 PM Friday to 8 am EDT Saturday for 
anz430-431. 


&& 


$$ 
Synopsis...nierenberg 
near term...Kline/delisi 
short term...Kline 
long term...nierenberg 
aviation...Kline/nierenberg/delisi 
marine...Kline/nierenberg 
rip currents...delisi