Tonight we have a major storm system developing over the Plains wich is spreading severe weather over the southern Plains which will spread into the Southeast and Mid Atlantic tomorrow , damaging winds, flooding rain and snow from Texas all the way to the Great Lakes , the associated developing warm front is producing showers over our region tonight, which will end later tonight when it moves north of the area
The low itself is rapidly developing in Kansas , and is pulling up abundant Gulf of Mexico moisture on its east side , the low will bomb out to a 970-972 mb storm passing through the Great Lakes, and the line of heavy rain and thunderstorms will come East- northeast coming though the area tomorrow night.
Rain showers will develop and overspread the area from west to east , and winds will increase through the day from south at 15-25 mph with higher gusts by late afternoon , the peak of the storm will begin over central PA between 6-8 pm and gradually move east with heavy downpours, strong winds and thunderstorms over spreading the area
The cause for this huge storm, is a deep and amplified trough digging into the central US , and arctic air is spilling in and interacting with warm conditions over the eastern 2/3 of the nation , we see a jet streak of 70-90 mph is developing with this system transporting moisture from SW to NE and producing damaging winds in thunderstorms as heavy rain pulls those winds to the surface, we will deal with the same thing tomorrow night
Images courtesy of Weather Bell
Above are the forecasted winds at 900 mb, (first is at 30 hrs , second is at 36 hrs) , which is above the surface but not by much, we will see this jet streak come through the area and intensify coming through the area due to the intensifying storm and less friction to play with as it approaches the coast and flatter land , with a jet streak of 65-90 knots passing through the area
In heavy rain and thunderstorms winds will gust to 50+ mph inland to as high as 70+ along the NJ coast, coastal CT and Long Island as the storm passes by , sustained winds of 25-35 mph can be expected so clearly damaging winds , and power outages are likely
The next aspect to this storm is flooding, a widespread 1.5-2.5 inches of rain is expected with localized areas up to 3 inches , for one all this liquid is going to fall over a relatively short period of time , and two, we have frozen ground and many areas have snow pack so flooding and fash flooding will be a big concern here as the ground will not be able to easily absorb the water either. Dont be surprised to see lightning and hear thunder with this system as it is very dynamic, we will no have the instability for severe lightning , the main threat with thunderstorms is the wind.
Flash flood watches and high wind watches have been issued area wide in anticipation for this storm system
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
251 PM EST TUE JAN 29 2013
MIDDLESEX-WESTERN MONMOUTH-EASTERN MONMOUTH-MERCER-SALEM-
EASTERN CHESTER-WESTERN MONTGOMERY-EASTERN MONTGOMERY-UPPER BUCKS-
INCLUDING THE CITIES OF…WILMINGTON…ELKTON…NEWTON…
NEW BRUNSWICK…FREEHOLD…SANDY HOOK…TRENTON…PENNSVILLE…
GLASSBORO…CAMDEN…CHERRY HILL…MOORESTOWN…MOUNT HOLLY…
WEST CHESTER…KENNET SQUARE…COLLEGEVILLE…POTTSTOWN…
251 PM EST TUE JAN 29 2013
…FLASH FLOOD WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A
* FLASH FLOOD WATCH FOR PORTIONS OF NORTHERN DELAWARE…
NORTHEAST MARYLAND…NEW JERSEY AND PENNSYLVANIA…INCLUDING
THE FOLLOWING AREAS…IN NORTHERN DELAWARE…NEW CASTLE. IN
NORTHEAST MARYLAND…CECIL. IN NEW JERSEY…CAMDEN…EASTERN
WARREN AND WESTERN MONMOUTH. IN PENNSYLVANIA…BERKS…
CARBON…DELAWARE…EASTERN CHESTER…EASTERN MONTGOMERY…
UPPER BUCKS…WESTERN CHESTER AND WESTERN MONTGOMERY.
* FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
* A SLOW-MOVING AND POTENT COLD FRONT WILL TAP THE GULF OF MEXICO,
AND IT IS FORECAST TO GENERATE RAINFALL AMOUNTS OF BETWEEN ONE AND
TWO AND ONE-HALF INCHES. LOCALLY HIGHER AMOUNTS UP TO 3 INCHES ARE POSSIBLE IN
PROLONGED AND HEAVY DOWNPOURS. MOREOVER, THUNDERSTORMS MAY
* PROLONGED AND HEAVY DOWNPOURS WOULD CAUSE FLASH FLOODING IN SOME
LOCATIONS. ROAD FLOODING IS LIKELY. SINCE THE GROUND IS FROZEN
JUST BELOW THE SURFACE AND PLANTS ARE TAKING IN VERY LITTLE
WATER, HEAVY RAINFALL WILL NOT BE ABSORBED. ANY LINGERING SNOW ON
THE GROUND NORTHWEST OF PHILADELPHIA WOULD MELT AND EXACERBATE
* FLOODING OF SMALLER AND MORE FLASHY CREEKS AND STREAMS ALSO IS
POSSIBLE. MAJOR RIVER FLOODING IS NOT LIKELY.
A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.
YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.
HIGH WIND WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
LATE WEDNESDAY NIGHT…
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A HIGH
WIND WATCH…WHICH IS IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
LATE WEDNESDAY NIGHT.
* WINDS…STRONG SOUTH WINDS WITH GUSTS OF OVER 60 MPH ARE
* TIMING…THE STRONGEST WINDS ARE EXPECTED JUST AHEAD OF THE COLD
FRONT, WHICH IS FORECAST TO ARRIVE AROUND MIDNIGHT WEDNESDAY
* IMPACTS…SOME TREES AND POWER LINES WOULD COME DOWN. THIS WOULD
RESULT IN POWER OUTAGES. SOME DAMAGE TO SMALL OR COMPROMISED
STRUCTURES WOULD OCCUR. MODERATE BEACH EROSION WOULD OCCUR.
A HIGH WIND WATCH MEANS THERE IS THE POTENTIAL FOR A HAZARDOUS
HIGH WIND EVENT. SUSTAINED WINDS OF AT LEAST 40 MPH OR GUSTS OF
58 MPH OR STRONGER MAY OCCUR. CONTINUE TO MONITOR THE LATEST
So prepare for a wind-blown heavy rain storm and be prepared for power outages and possible flooding if you live near streams or rivers. Coastal flooding is also likely along south-facing beaches , especially with the coast still severely damaged from superstorm Sandy