Post Reply 
Severe Weather 12-7-09 to 12-8-09
12-05-2009, 10:52 AM
Post: #1
Severe Weather 12-7-09 to 12-8-09
[Image: day3otlk_0830.gif]

Quote:DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0220 AM CST SAT DEC 05 2009

VALID 071200Z - 081200Z

...SYNOPSIS...
MODELS INDICATE THAT A STRONG SHORT WAVE TROUGH...DIGGING ALONG THE
PACIFIC NORTHWEST COAST EARLY MONDAY...WILL REMAIN PROGRESSIVE...AS
ANOTHER SIGNIFICANT SHORT WAVE IMPULSE DIGS TO THE EAST OF THE
BLOCKING HIGH CENTERED OVER ALASKA. THE LEAD FEATURE APPEARS LIKELY
TO CONTINUE DIGGING THROUGH CALIFORNIA EARLY IN THE PERIOD...BEFORE
TURNING EASTWARD INTO THE GREAT BASIN/SOUTHERN PLATEAU MONDAY NIGHT.
GUIDANCE IS SUGGESTIVE THAT ANOTHER IMPULSE...EMANATING FROM A
STRONG ZONAL BELT OF WESTERLIES UNDERCUTTING THE HIGH...WILL PRECEDE
IT...MIGRATING INLAND ACROSS SOUTHERN CALIFORNIA EARLY IN THE DAY.
AT THE SAME TIME...ANOTHER IMPULSE IS PROGGED TO ACCELERATE EAST
NORTHEASTWARD OUT OF THE SUBTROPICAL EASTERN PACIFIC.

COMPLEXITY ASSOCIATED WITH THE INTERACTING STREAMS AND EMBEDDED
PERTURBATIONS APPEARS TO BE THE SOURCE OF THE LARGE SPREAD AMONG THE
MODELS AND NCEP SREF/MREF MEMBERS CONCERNING THE LARGE-SCALE PATTERN
EVOLUTION INTO THE BEGINNING OF THE WORK WEEK. BUT...AN
INTENSIFYING MID-LEVEL JET STREAK /ON THE ORDER OF 100+ KT AT 500
MB/ APPEARS LIKELY ACROSS SOUTHERN CALIFORNIA INTO THE SOUTHERN
PLATEAU BY 12Z TUESDAY...ACCOMPANIED BY SURFACE CYCLOGENESIS ACROSS
THE GREAT BASIN. ADDITIONALLY...STRENGTHENING SOUTHERLY LOW-LEVEL
FLOW OFF THE GULF OF MEXICO APPEARS PROBABLE MONDAY NIGHT...ALONG
WITH A CONTINUED MOISTENING OF THE BOUNDARY LAYER OVER THE GULF OF
MEXICO.

THESE TRENDS ARE EXPECTED TO LEAD TO INCREASING PROBABILITIES OF
THUNDERSTORM ACTIVITY ACROSS PARTS OF THE INTERMOUNTAIN WEST AND
SOUTH CENTRAL STATES DURING THIS PERIOD. HOWEVER...AN INITIALLY
COOL/DRY BOUNDARY LAYER ACROSS THESE AREAS...AND MUCH OF THE REST OF
THE NATION...WILL BE DIFFICULT TO QUICKLY MODIFY...LIKELY LIMITING
CONVECTIVE POTENTIAL.

...WESTERN/CENTRAL GULF COAST...
STRENGTHENING LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION
ASSOCIATED WITH THE SUBTROPICAL IMPULSE IS EXPECTED TO CONTRIBUTE TO
INCREASING THUNDERSTORM ACTIVITY ACROSS PARTS OF THE NORTHWESTERN
GULF OF MEXICO INTO THE LOWER MISSISSIPPI VALLEY BY LATE MONDAY
NIGHT. THIS PROBABLY WILL OCCUR IN THE PRESENCE OF STRONG DEEP
LAYER SHEAR AND ENLARGING...CLOCKWISE CURVED... LOW-LEVEL HODOGRAPHS
THAT COULD BECOME SUPPORTIVE OF INCREASING SEVERE POTENTIAL. EVEN
WITH ONLY WEAK CAPE PROGGED BY MOST MODEL GUIDANCE...IT APPEARS A
POSSIBILITY THAT STORMS DEVELOPING OFFSHORE COULD APPROACH COASTAL
AREAS WITH A RISK FOR A TORNADO OR DAMAGING WINDS. BUT...A
LINGERING STABLE LAYER NEAR THE SURFACE OVER INLAND AREAS IS
CURRENTLY EXPECTED TO LIMIT THIS THREAT.

..KERR.. 12/05/2009

CLICK TO GET WUUS03 PTSDY3 PRODUCT





[Image: day48prob.gif]


Quote:ZCZC SPCSWOD48 ALL
ACUS48 KWNS 050956
SPC AC 050956

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0356 AM CST SAT DEC 05 2009

VALID 081200Z - 131200Z

...SEVERE STORMS POSSIBLE ACROSS THE SOUTHEAST TUE/TUE NIGHT...

MEDIUM RANGE GUIDANCE CONTINUES TO INDICATE THAT STRONG SURFACE
CYCLOGENESIS IS LIKELY FROM THE LEE OF THE CENTRAL/SOUTHERN ROCKIES
THROUGH THE NORTHEAST DURING THE EARLY TO MIDDLE PORTION OF THE
COMING WORK WEEK. SUBSTANTIAL SPREAD PERSISTS AMONG THE VARIOUS
MODELS AND MODEL ENSEMBLES CONCERNING THE DETAILS OF THIS EVOLUTION.
BUT...IT CURRENTLY SEEMS PROBABLE THAT THE MAIN SHORT WAVE TROUGH
ACCELERATING EAST OF THE GREAT BASIN ON TUESDAY WILL BE PRECEDED BY
A SIGNIFICANT SHORT WAVE IMPULSE...EMANATING FROM THE SUBTROPICAL
EASTERN PACIFIC...ACROSS THE EASTERN GULF COAST STATES THROUGH THE
MIDDLE/SOUTHERN ATLANTIC COAST STATES BY 12Z WEDNESDAY.
MODIFICATION OF THE BOUNDARY LAYER OVER THE GULF OF MEXICO LIKELY
WILL BE SUPPORTIVE OF A SUBSTANTIVE RETURN FLOW OF MOISTURE BY THIS
TIME. ASSOCIATED DESTABILIZATION...COINCIDENT WITH INTENSIFYING
SOUTHERLY LOW-LEVEL FLOW FIELDS THAT ARE PROGGED TO YIELD STRONG TO
EXTREME LOW-LEVEL SHEAR...SHOULD BECOME VERY FAVORABLE FOR SEVERE
STORMS WITH POTENTIAL FOR TORNADOES AND DAMAGING WINDS.

..KERR.. 12/05/2009
Find all posts by this user
Quote this message in a reply
12-06-2009, 04:15 PM
Post: #2
Severe Weather 12-7-09 to 12-8-09
[Image: image4.gif]

Twitter updates we will follow you back
http://twitter.com/Hardcoreweather
Now on Facebook We will like you back
http://www.facebook.com/pages/Hardcorewe...466?v=wall


Visit this user's website Find all posts by this user
Quote this message in a reply
12-07-2009, 06:41 AM
Post: #3
Severe Weather 12-7-09 to 12-8-09
N.O. NWS:

Quote:DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
WARM MOIST AIR WILL SURGE NORTH ON TUESDAY AS THE FRONT MOVES
FURTHER INLAND AND LOW PRESSURE DEVELOPS OVER NW TEXAS AND W OK. A
STRONG 50 TO 60 KNOT LOW LEVEL JET WILL DEVELOP...AND WITH
ADEQUATE DEEP LAYER SHEAR IN PLACE...SHOWERS AND THUNDERSTORMS ARE
EXPECTED. A FEW THUNDERSTORMS COULD BECOME SEVERE...WITH SPC
INDICATING A SLIGHT RISK FOR SEVERE WEATHER. THE PRIMARY THREATS
ASSOCIATED WITH ANY SEVERE STORMS WILL BE DAMAGING WINDS AND
POSSIBLY A FEW TORNADOES.

SHOWERS AND THUNDERSTORMS WILL END FROM WEST TO EAST TUESDAY NIGHT
AS A COLD FRONT PUSHES THROUGH THE AREA. DRIER COOLER WEATHER IS
EXPECTED FOR WEDNESDAY INTO THURSDAY. THE NEXT CHANCE FOR RAIN
COMES LATE IN THE WEEK AS ANOTHER LOW PRESSURE SYSTEM DEVELOPS
OVER THE GULF OF MEXICO.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED TUESDAY.

"The ultimate judge of your swing is the flight of the ball." - Ben Hogan
Find all posts by this user
Quote this message in a reply
12-07-2009, 07:43 AM
Post: #4
Severe Weather 12-7-09 to 12-8-09
Set up has diminished and severe weather is looking unlikely.. Looks like a more just rainy event.. heavy at times..
Find all posts by this user
Quote this message in a reply
12-07-2009, 08:37 AM
Post: #5
Severe Weather 12-7-09 to 12-8-09
Quote:SPC AC 070548

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1148 PM CST SUN DEC 06 2009

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE LOWER MS
VALLEY INTO THE CNTRL GULF STATES...

...SYNOPSIS...

CONSIDERABLE STRENGTHENING/BROADENING OF MID/HIGH-LEVEL JET STREAKS
IS FORECAST FROM THE SRN ROCKIES ENEWD INTO THE LOWER MS/LOWER OH
VALLEYS DURING THE DAY TWO PERIOD. THIS INCREASING FLOW FIELD WILL
OCCUR ON SRN FRINGE OF MIDLEVEL TROUGH WHICH WILL BECOME NEGATIVELY
TILTED WHILE TRANSLATING FROM THE FOUR CORNERS REGION INTO THE OH
VALLEY AND UPPER GREAT LAKES.

AT THE SURFACE...PRIMARY CYCLONE IS FORECAST TO INITIALLY DEVELOP
ESEWD FROM SWRN CO INTO OK BEFORE ACCELERATING NEWD INTO IL/IND BY
WEDNESDAY MORNING. 07/00Z MODEL GUIDANCE NOW SUGGESTS THAT THE MOST
INTENSE DEEPENING OF THE SURFACE LOW WILL OCCUR BETWEEN
09/06Z-09/12Z...WELL AWAY FROM EFFECTIVE WARM SECTOR. THE PRIMARY
FOCUS FOR STRONG TO SEVERE CONVECTIVE STORMS IS EXPECTED TO BE
DELINEATED BY NE-SW ORIENTED BOUNDARY/CONVERGENCE ZONE STRETCHING
FROM THE TX COASTAL PLAINS INTO THE MS DELTA REGION AND WARM FRONT
WHICH WILL BE RAPIDLY LIFTING NWD THROUGH MS AND AL. THE ERN
EXTENSION OF THE WARM FRONT WILL BE REMNANT WEDGE FRONT WHICH WILL
MOVE MORE SLUGGISHLY NWD THROUGH GA AND THE PIEDMONT AND COASTAL
PLAINS OF THE CAROLINAS.

...LOWER MS VALLEY INTO CNTRL GULF COAST STATES...

OVERALL DEEPENING OF SYNOPTIC SYSTEM WILL RESULT IN A CONSIDERABLE
BROADENING AND INTENSIFICATION OF SWLY LLJ TUESDAY WHICH WILL SERVE
TO ENHANCE THE NWD/NEWD FLUX OF AN INCREASINGLY MOIST BOUNDARY LAYER
WITH DEWPOINTS RISING THROUGH THE 60S. HOWEVER...AS WITH PREVIOUS
MODEL RUNS...IT APPEARS THAT WEAK LAPSE RATES /I.E. LESS THAN MOIST
ADIABATIC/ WILL LIMIT THE DEGREE OF AIR MASS DESTABILIZATION WITH
MLCAPE OF LESS THAN 500-1000 J/KG FORECAST THROUGH THE PEAK OF THE
DIURNAL HEATING CYCLE.

TSTMS ARE FORECAST TO BECOME QUITE NUMEROUS THROUGH THE DAY WITHIN
EXPANDING WARM SECTOR AS LOW-LEVEL WAA ATTENDANT TO BROAD LLJ ACTS
ON MOISTENING/DESTABILIZING BOUNDARY LAYER. KINEMATIC ENVIRONMENT
WILL BE QUITE FAVORABLE FOR UPDRAFT ROTATION/LONGEVITY WITH 45-65 KT
OF DEEP-LAYER SHEAR AND 0-1 KM SHEAR APPROACHING 40-45 KT. THE
PRIMARY INGREDIENT LIMITING A MORE WIDESPREAD SEVERE WEATHER EVENT
CURRENTLY APPEARS TO BE THE WEAK LAPSE RATES AND RESULTING MARGINAL
CONVECTIVE INSTABILITY. NONETHELESS...OVERALL SETUP WILL BE
SUPPORTIVE OF EMBEDDED BOWING AND/OR SUPERCELL STRUCTURES CAPABLE OF
DAMAGING WINDS AND TORNADOES.

THE POTENTIAL FOR DAMAGING WINDS AND A FEW TORNADOES WILL LIKELY
SPREAD NEWD/EWD OVERNIGHT...THOUGH THE THREAT SHOULD GENERALLY
DIMINISH WITH TIME AS ONGOING STORMS ENCOUNTER AN INCREASINGLY
STABLE AIR MASS.

...CAROLINAS...

EWD MIGRATION/DEVELOPMENT OF SLY LLJ WILL HASTEN THE INFLUX OF
MOISTURE OFF THE WRN ATLANTIC...AND EVENTUALLY ERN GULF OF MEXICO
BASIN IN WAKE OF RETREATING WEDGE FRONT. WHILE THE GREATER AIR MASS
DESTABILIZATION IS FORECAST TO REMAIN CONFINED TO THE VICINITY OF
THE GULF STREAM...IT DOES APPEAR THAT SUFFICIENT INSTABILITY MAY BE
PRESENT TO SUPPORT THE DEVELOPMENT OF ISOLATED/SCATTERED NOCTURNAL
STORMS WITHIN STRENGTHENING WAA REGIME. GIVEN THE STRONG...AMBIENT
VERTICAL SHEAR FORECAST...AT LEAST A LOW PROBABILITY THREAT FOR
SEVERE WEATHER WILL EXIST WITH ANY SUSTAINED UPDRAFTS.

..MEAD.. 12/07/2009

CLICK TO GET WUUS02 PTSDY2 PRODUCT

NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
<script type="text/javascript" src="http://www.spc.noaa.gov/misc/utctime.js"></script> CURRENT UTC TIME: 1335Z (7:35AM), RELOAD THIS PAGE TO UPDATE THE TIME

[Image: day2otlk_0700.gif]

Twitter updates we will follow you back
http://twitter.com/Hardcoreweather
Now on Facebook We will like you back
http://www.facebook.com/pages/Hardcorewe...466?v=wall


Visit this user's website Find all posts by this user
Quote this message in a reply
12-07-2009, 08:45 AM
Post: #6
Severe Weather 12-7-09 to 12-8-09
[Image: image3.gif]

Twitter updates we will follow you back
http://twitter.com/Hardcoreweather
Now on Facebook We will like you back
http://www.facebook.com/pages/Hardcorewe...466?v=wall


Visit this user's website Find all posts by this user
Quote this message in a reply
12-07-2009, 08:55 AM
Post: #7
Severe Weather 12-7-09 to 12-8-09

Twitter updates we will follow you back
http://twitter.com/Hardcoreweather
Now on Facebook We will like you back
http://www.facebook.com/pages/Hardcorewe...466?v=wall


Visit this user's website Find all posts by this user
Quote this message in a reply
12-07-2009, 12:21 PM
Post: #8
Severe Weather 12-7-09 to 12-8-09
Mobile

Quote:DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON TUESDAY WITH THE
AIRMASS BECOMING INCREASINGLY WARM AND HUMID TO THE SOUTH OF THE
BOUNDARY. A COLD FRONT WILL THEN MOVE ACROSS THE AREA DURING THE DAY
WEDNESDAY. WITH A MUCH WARMER AIRMASS ACROSS THE AREA AND A COLD
FRONT APPROACHING FROM THE WEST...THERE WILL BE A SMALL POTENTIAL
FOR A FEW STRONG TO SEVERE THUNDERSTORMS OVER THE NORTHERN GULF
COAST FROM TUESDAY AFTERNOON INTO EARLY WEDNESDAY. HOWEVER...THE
AMOUNT OF INSTABILITY CURRENTLY APPEARS TO BE LACKING TO SUPPORT A
WIDESPREAD SEVERE WEATHER EVENT
. IF ENOUGH INSTABILITY WERE TO
MATERIALIZE... THE STORMS WOULD BE CAPABLE OF PRODUCING DAMAGING
WIND GUSTS OF 60 MPH AND PERHAPS AN ISOLATED TORNADO. STAY TUNED FOR
UPDATES ON THIS DEVELOPING WEATHER SYSTEM AS ANY INCREASE IN
INSTABILITY WILL RESULT IN A MORE SUBSTANTIAL SEVERE WEATHER THREAT.

Twitter updates we will follow you back
http://twitter.com/Hardcoreweather
Now on Facebook We will like you back
http://www.facebook.com/pages/Hardcorewe...466?v=wall


Visit this user's website Find all posts by this user
Quote this message in a reply
12-07-2009, 02:22 PM
Post: #9
Severe Weather 12-7-09 to 12-8-09
This is another storm system that had a lot of tornadic potential, but there's just not enough instability. We may see a couple stray tornadoes, mainly across MS, but the primary threat will be damaging winds.

- South Alabama Met Student
- NWS Trained Storm Spotter
Find all posts by this user
Quote this message in a reply
12-07-2009, 04:38 PM
Post: #10
Severe Weather 12-7-09 to 12-8-09

Twitter updates we will follow you back
http://twitter.com/Hardcoreweather
Now on Facebook We will like you back
http://www.facebook.com/pages/Hardcorewe...466?v=wall


Visit this user's website Find all posts by this user
Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)