Severe NE Weather Maybe 9-10 Nov 2005

[arlwx]

LWX may have gotten a little excited, as they posted this three times, but... (emphasis mine)

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
700 AM EST WED NOV 9 2005

HAVE SENT A QUICK UPDATE MAINLY TO CANCEL REMAINDER OF DENSE FOG ADV
AS LGT SHWRS HAVE CAUSED FOG CONDS TO IMPROVE SOMEWHAT. WHILE I WAS
AT IT...ALSO TWEAKED MAX TEMPS DOWN A COUPLE DEGS AND INCREASED POPS
A LITTLE IN THE NORTH WHERE LARGE AREA OF SHOWERS ARE ONGOING THIS
MORNING.

JB

&&

.SHORT TERM...TODAY AND TONIGHT...

AXIS OF SHWRS/TSTM LOCATED FROM ERN OH...ACROSS CENTRAL WV AND S
CTRL VA EARLY THIS MORNING IN ASSOC WITH WARM FRONT. EXPECT THIS
ACTIVITY TO CONTINUE SLOWLY MOVING E/NE THIS MORNING AND WILL AFFECT
OUR WESTERN AND SW COUNTIES THROUGH LATE MORNING. THEN WE BELIEVE
THE WARM FRONT WILL MOVE SLOWLY NORTH AND LOSE SOME IDENTITY THROUGH
MIDDAY. BELIEVE SOME SCATTERING OF THE LOW CLOUDS WILL OCCUR IN THE
SOUTH TODAY ALLOWING FOR SOME DESTABILIZATION THERE. HOWEVER BELIEVE
WARM FRONT WILL KEEP MAINLY CLOUDY CONDS IN TACT ACROSS THE NORTHERN
CWA INC AREAS N OF I-66.

PROMINENT ONSHORE E/NE WINDS FROM SFC TO BL IN PLACE IN OUR REGION
ATTM...REF 88D VWP...AND BELIEVE THIS WILL CONTINUE THROUGH MUCH OF
THE MORNING...REINFORCING THE SATURATED LOW LEVELS AND LACK OF SFC
BASED INSTABILITY. THEN BY LATE AFTN...WITH WIND SHIFTING TO THE SW
IN ADVANCE OF STRONG COLD FRONT...BELIEVE THIS WILL ALLOW CLOUDS TO
DECREASE SOMEWHAT AND FOR SOME MARG INSTABILITY BY LATE AFTN. BOTH
GFS AND NAM SNDGS INDICATE SFC LI'S OF -2 BY EARLY EVNG ACROSS OUR
CWA. IN ADDITION WIND PROFILES FAV FOR DAMAGING WIND GUSTS...AND IF
SFC INSTAB DVLPS THEN STRONG HELICITY VALUES WOULD SUPPORT ISO
TORNADOES. [b]HWVR NOT CONFIDENT ENOUGH FOR SFC HEATING TO OCCUR SO
WILL DECLINE TO MENTION TOR FOR NOW...BUT WILL CONTINUE TO MENTION
SLGT RISK FOR SVR MAINLY DUE TO LARGE HAIL (FRIG LVL ~10KFT) AND
DAMAGING WIND GUSTS[/b]. MODEL SNDGS INDICATE BEST SFC INSTAB OF -2 TO
-3 AT MANY LOCATIONS BTWN 4-8 PM SO WILL INDICATE THAT AS THE BEST
TIMING FOR NOW.

POPS TODAY LIKELY IN THE WEST. THIS EVENING HAVE INDICATED 60 POPS
EVERYWHERE FOR AT LEAST A COUPLE HRS WITH FROPA...BUT EXPECT THE
HIGHEST QPF VALUES ACROSS THE WEST AND NORTH CLOSER TO BETTER
FORCING AND U/L SUPPORT.

STRONG TEMP GRAD ACROSS THE CWA DUE TO THE FRONTAL BNDRY. THINK THE
GFS MOS MAY BE MORE IN LINE FOR MAX TEMPS TODAY WITH THE NAM SEEMING
TOO WARM EVEN ACROSS THE SOUTH WHERE WE ARE NOT CONFIDENT ABOUT SFC
HEATING THIS AFTN.

&&

.AVIATION...

LIFR CONDS AT MOST SITES THIS MORNING. EXPECT CONDS TO ONLY SLOWLY
IMPROVE BTWN MID AND LATE MORNING FROM S TO N DUE TO WARM FRONT.
DENSE FOG ADVISORY IN PLACE AS WELL TIL 10 AM.

&&

.MARINE...

SOUTHWEST WINDS WILL DEVELOP IN ADVANCE OF THE COLD FRONT THIS
AFTERNOON...ESP OVER THE SOUTHERN WATERS. HWVR DO NOT EXPECT SCA
CRITERIA WINDS TO DEVELOP TIL MIDNIGHT OR LATER WITH THE PASSING OF
THE COLD FRONT.

STRONG SMALL CRAFT CONDITIONS ARE FORECAST TO CONTINUE THROUGH
THURSDAY. WHILE MOS GUIDANCE SUGGESTS WINDS MAY BE SUSTAINED AROUND
25KT AND NAM/GFS BUFKIT INDICATE MIXING TO OR ABOVE 35 KNOT
GUSTS...HAVE DECIDED TO KEEP 20G30KT AS FORECAST...AND ALLOW FURTHER
REFINEMENT (POSSIBLE UPGRADE TO LOW END GALES) AS THE EVENT
APPROACHES. EXPECTING GRADIENT TO SUSTAIN 15 TO 20 KNOT WINDS
THROUGH FRIDAY.

&&

.LONG TERM (THURSDAY THROUGH TUESDAY)...

SYNOPSIS...MODELS IN GOOD AGREEMENT BLASTING A COLD FRONT THROUGH
THE FORECAST AREA DURING THE SECOND HALF OF WEDNESDAY NIGHT...WHICH
WILL YIELD A WINDY THURSDAY. UPSLOPE SNOW SHOWERS MAY OCCUR ALONG
AND WEST OF THE ALLEGHENY FRONT THURSDAY WITH AN ACCUMULATION OF AN
INCH POSSIBLE. RISING HEIGHTS WILL ALLOW REBOUNDING TEMPERATURES AND
RELATIVELY CLEAR CONDITIONS LATE DURING THE WEEK AND INTO THE
WEEKEND. DESPITE ENSEMBLE MEMBERS VARIANCE...OPERATIONAL MODELS ARE
IN GOOD AGREEMENT IN SHOWING A WEAKENING TROUGH APPROACHING FROM THE
WEST EARLY NEXT WEEK.

OBSERVATIONS...500MB HEIGHT/ANOMALY PATTERN DURING THE PAST 5 DAYS
INDICATES A TROUGH-RIDGE-TROUGH BLOCKING PATTERN HAS DOMINATED THE
PACIFIC...WHILE RATHER FLAT FLOW ACROSS THE NORTHERN CONUS HAS
ALLOWED OCCASIONAL WAVES TO RIDE ALONG THE CANADIAN BORDER. WATER
VAPOR LOOP SHOWS A TROUGH MOVING EAST INTO THE CANADIAN
MARITIMES...WHILE A STRONG WAVE PUSHES ACROSS THE UPPER MIDWEST ATOP
A FLATTENING RIDGE. 04Z SURFACE ANALYSIS PLACES A 1021MB ANTICYCLONE
ACROSS CENTRAL VIRGINIA. A WARM/STATIONARY BOUNDARY STRETCHES
SOUTHEAST FROM A TRIPLE POINT IN MINNESOTA THROUGH WEST
VIRGINIA...BEFORE BUCKLING SOUTH AND PARALLELING THE NORTH CAROLINA
BORDER. A 1025MB ANTICYCLONE DOMINATES SOUTHERN QUEBEC WHILE THE
NEXT COLD FRONT BEGINS TO SURGE EAST ACROSS THE CENTRAL CONUS.

MODELS...THE 00Z NAM/GFS/CANADIAN ALONG WITH THE 12Z UKMET/EUROPEAN
WERE INSPECTED. OPERATIONAL MODELS IN GOOD AGREEMENT WITH SHOWING A
COLD FRONTAL PASSAGE FROM THE NORTHWEST LATE WEDNESDAY NIGHT. RISING
HEIGHTS OCCUR THROUGH THE EARLY WEEKEND...BEFORE A WEAKENING TROUGH
APPROACHES FROM THE WEST EARLY NEXT WEEK.

ENSEMBLE DATA...12Z GFS 500MB HEIGHT ENSEMBLES INDICATE A WAVE
DEEPENS INTO A TROUGH WHICH PASSES FROM THE NORTHWEST THURSDAY (WITH
GOOD CONSISTENCY)...WITH RIDGING BUILDING IN FOR THE WEEKEND.
MEMBERS DIVERGE BY EARLY NEXT WEEK...WITH A HIGH AMOUNT OF
UNCERTAINTY IN THE HIGHT FIELD ACROSS THE REGION (WITH REGARD TO THE
NEXT TROUGH).

GFS ENSEMBLE MOS FROM MONDAY NIGHT INDICATES MEAN HIGH TEMPERATURES
IN THE MID 50S LATE DURING THE WEEK...BEFORE RECOVERING TO ABOUT 60
EARLY NEXT WEEK. MEAN LOW TEMPERATURES NEAR FREEZING LATE DURING THE
WEEK...RECOVER TO NEAR 40 BY MONDAY MORNING. MEAN POPS NEAR ZERO
LATE DURING THE WORK WEEK RISE NEAR THE LOW CHANCE RANGE EARLY NEXT
WEEK.

FORECAST RATIONALE...A STRONG COLD FRONT IS FORECAST TO CROSS THE
REGION LAST WEDNESDAY NIGHT. THIS WILL PROMOTE THE ONSET OF WINDY
CONDITIONS (WITH BUFKIT SHOWING 35 KNOTS OF MIXING POTENTIAL)...AND
UPSLOPE SNOW SHOWERS CONTINUING INTO THURSDAY ALONG AND WEST OF THE
ALLEGHENY FRONT. UPSLOPE EVENT SHOULD BE SHORT LIVED...AS RIDGING
SHOULD ENCOURAGE INCREASED BOUNDARY LAYER SHEAR AND WARMING THROUGH
THE COLUMN THURSDAY NIGHT AND FRIDAY.

FAIR WEATHER AND REBOUNDING TEMPERATURES ARE EXPECTED FRIDAY INTO
THE WEEKEND AS OPERATIONAL MODELS AND ENSEMBLE MEMBERS INDICATE A
RIDGE BUILDING INTO THE REGION. BY LATE IN THE FORECAST
CYCLE...CLOUDS MAY BE ON THE INCREASE WITH THE POTENTIAL OF SHOWERS
AHEAD OF A WEAKENING TROUGH.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...DENSE FOG ADVISORY FOR VAZ021-025>027-029-030-036>041-050>052-
055>057 UNTIL 10 AM WEDNESDAY.
WV...DENSE FOG ADVISORY FOR WVZ048-054-055 UNTIL 10 AM WEDNESDAY.
MARINE...SMALL CRAFT ADVISORY FOR ANZ530>537 FROM MIDNIGHT TO
6 PM FRIDAY.

&&

$$

SHORT TERM/AVIATION FORECASTER...BROTHERTON
LONG TERM FORECASTER...ROGOWSKI
MARINE FORECAST...BROTHERTON/ROGOWSKI

[wxmann_91]

Tornadoes are possible but I imagine with the marginal instability today it doesn't look very promising for tornadoes.

EDIT: Severe thunderstorm watch issued for portions of WESTERN NEW YORK, NORTHEASTERN OHIO, NORTHWESTERN PENNSYLVANIA, LAKE ERIE, and LAKE ONTARIO.