Stalling out
Posted by JAC on 11/12/2009, 7:18 am







SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
208 AM EST THU NOV 12 2009

VALID 12Z THU NOV 12 2009 - 00Z SAT NOV 14 2009

THE EXTRATROPICAL CYCLONE THAT WAS FORMERLY HURRICANE IDA...HAS
MOVED OFF THE SOUTHEAST COAST OF THE UNITED STATES AND HAS BEEN
ABSORBED BY AN UPPER-LEVEL TROUGH. OVER THE WEEKEND THE CENTRAL
LOW PRESSURE OF THIS SYSTEM IS EXPECTED TO DEEPEN WHILE REMAINING
QUASI-STATIONARY OFF THE COAST OF THE CAROLINAS. THIS MEANS
MODERATE TO HEAVY RAIN WILL CONTINUE TO PLAGUE THE MID-ATLANTIC
STATES THROUGH THE WEEKEND. HIGH TEMPERATURES IN WILL BE IN THE
UPPER 40'S TO MID 50'S IN STATES WHERE RAIN IS FALLING.
HOWEVER...IN THE SURROUNDING AREAS NOT AFFECTED BY THE RAIN FROM
THIS STORM TEMPERATURES WILL REACH MID TO UPPER 60'S DURING THE
DAY THIS WEEKEND.


WELL-ADVERTISED VERY HVY TO EXCESSIVE RNFL EVENT CONTINUES OVR THE
MID ATLC REGION AS SLOW MOVG UPPER VORTEX AND ASOCTD SFC DVLPMNT
MAINTAINS MOIST DEEP-LAYERED ELY FLOW INTO THE REGION.  THERE ARE
DISCREPANCIES BTWN MODELS AS TO WHERE HEAVIEST RNFL WILL OCCUR DUE
TO SLGT DIFFERENCES IN MID/UPPER LVL FCSTS AND THE EXTENT OF
DVLPMNT OF THE PIVOTING SFC LO.  THE AVBL INFLOW AND PWS CERTAINLY
ARGUE FOR THE POTENTIAL FOR RAINS IN EXCESS OF FIVE INCHES BUT THE
EVENT CAN BE CHARACTERIZED AS ONE OF DURATION MORE THAN INTENSITY
WHICH SHOULD LIMIT THE CHANCES FOR RAINFALL EXCEEDING FLASH FLOOD
GUIDANCE.  IN ANY CASE...COULD SEE 2.00 INCH RNFL TOTALS IN 3 TO 6
HOURS WITH RNFL TOTALS THRU THE PD EXPECTED TO EXCEED FIVE INCHES
OVR LOCALIZED AREAS.


MESOSCALE DISCUSSION 2175
  NWS STORM PREDICTION CENTER NORMAN OK
  0352 AM CST THU NOV 12 2009
 
  AREAS AFFECTED...FAR ERN NC
 
  CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
 
  VALID 120952Z - 121045Z
 
  A MARGINAL TORNADO THREAT WILL CONTINUE UNTIL AFTER DAYBREAK ACROSS
  THE OUTER BANKS OF NC. A TORNADO WATCH CAN NOT BE RULED OUT
  ESPECIALLY IF THE STRONGER ROTATING CELL ELEMENTS CAN APPROACH
  PAMLICO SOUND.
 
  A BROKEN LINE OF THUNDERSTORMS WITH EMBEDDED ROTATING CELLS WILL
  CONTINUE TO MOVE GRADUALLY NWD EARLY THIS MORNING AND WILL BEGIN TO
  AFFECT THE CAPE LOOKOUT NATIONAL SEASHORE OVER THE NEXT FEW HOURS.
  THE MOREHEAD CITY WSR-88D VWP CONTINUES TO SHOW STRONG LOW-LEVEL
  SHEAR PROFILES WITH ABOUT 40 KT OF FLOW AT 1 KM. THIS SUGGESTS A
  THREAT FOR ROTATING STORMS WITH A MARGINAL TORNADO POTENTIAL WILL
  EXIST EARLY THIS MORNING. ALTHOUGH THE LINE IS MOVING SLOWLY
  NEWD...THE THREAT MAY INCREASE AS THE INDIVIDUAL CELLS MOVE NWD INTO
  A BIT STRONGER FLOW CURRENTLY IN PLACE ACROSS CAPE HATTERAS.
  INSTABILITY IS ALSO FORECAST TO INCREASE WITH DEWPOINTS ACROSS THE
  OUTER BANKS REACHING THE UPPER 60S F. THE DISCRETE NATURE OF THE
  CONVECTION SUGGESTS A TORNADO WILL BE POSSIBLE AND WW ISSUANCE IS
  BEING CONSIDERED.
 
  ..BROYLES.. 11/12/2009
 
RICHMOND, Va. -- Virginia's governor declared a state of emergency Wednesday as unrelenting rain from the remnants of a tropical storm soaked the state, while officials in North Carolina braced for another day of heavy rain.

Gov. Tim Kaine's declaration mobilizes state agencies to prepare for the threat of flooding over a wide swath of Virginia.

The National Weather Service forecasts 3 to 8 inches through Friday morning for parts of Virginia as the remains of Tropical Storm Ida, which was once a hurricane, crawl across the state. Old Dominion University in Norfolk canceled classes Thursday.

A coastal flood warning was posted for some areas thanks to a storm surge coinciding with high tide. A flood watch is out for central, eastern and southeastern areas farther inland.

Kaine's declaration urges Virginians in tidal flood plains and areas prone to flash flooding to be on alert.

In North Carolina, the eastern two-thirds of the state was braced for another day of significant rain.

National Weather Service meteorologist Phil Badgett said heavy rainfall is expected east of a line from the Triad to the Research Triangle area and down to Wilmington. With strong, gusty winds expected, Badgett said falling trees could be a threat.

Raleigh had reported 4.25 inches of rain from daybreak Tuesday through 8 p.m. Wednesday. In the mountainous western part of the state, Asheville got nearly 4 inches.

Alabama also reported some impressive rainfall totals from the storm, which dumped 9.8 inches on Opelika and more than 6 inches near the coast in Baldwin County and in parts of central Alabama.

Ida came ashore at Dauphin Island early Tuesday.

In Georgia, National Weather Service meteorologist Verona Murrell said the rains have stopped, but officials are watching rivers and streams that have risen above flood stage.

"We've got several sites that are in flooding and quite a few places that have flood warnings out," Murrell said.

(Copyright 2009 by The Associated Press. All Rights Reserved.)



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Coastal low? Nor'easter? - BobbiStorm, 11/11/2009, 3:01 pm
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