STRONG TORNADOES ARE POSSIBLE BY THIS AFTERNOON IN
N LA, S AR AND W CENTRAL MS
N LA, S AR AND W CENTRAL MS
Probability of a tornado within 25 miles of any point
From the SPC:
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0716 AM CST TUE DEC 09 2008
...SEVERE THUNDERSTORMS EXPECTED OVER PARTS OF THE LOWER MISSISSIPPI
VALLEY TODAY...
THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF A FEW STRONG TORNADOES OVER PARTS OF THE LOWER
MISSISSIPPI VALLEY TODAY.
THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE
MUCH OF NORTHERN LOUISIANA
MUCH OF CENTRAL AND SOUTHERN MISSISSIPPI
ELSEWHERE...SEVERE STORMS ARE ALSO POSSIBLE ACROSS THE REMAINDER OF
THE LOWER MISSISSIPPI VALLEY TODAY AND EARLY TONIGHT
A STRONG UPPER TROUGH IS DEVELOPING EWD ACROSS THE SRN PLAINS
PRECEEDED BY AN INCREASINGLY MOIST UNSTABLE FLOW OFF THE WESTERN
GULF OF MEXICO. STRONG/SEVERE THUNDERSTORMS HAVE BEEN OCCURRING
OVERNIGHT ACROSS PORTIONS OF ERN TX/OK INTO AR AND WILL BE
DEVELOPING EWD ACROSS LOWER MS VALLEY DURING THE DAY. WITH DAYTIME
HEATING AND CONTINUED INCREASING GULF MOISTURE...SEVERE
THUNDERSTORMS EXPECTED TO INCREASE IN NUMBER AND INTENSITY.
SUPERCELLS INCLUDING THE POSSIBILITY OF STRONG TORNADOES ARE
POSSIBLE GIVEN THE STRENGTH OF THE WINDS FIELDS ALONG WITH THE
EXPECTED INSTABILITY.
THOSE IN THE THREATENED AREA ARE URGED TO REVIEW SEVERE WEATHER
SAFETY RULES AND TO LISTEN TO RADIO...TELEVISION...AND NOAA WEATHER
RADIO FOR POSSIBLE WATCHES...WARNINGS...AND STATEMENTS LATER TODAY.
..HALES.. 12/09/2008
---
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0656 AM CST TUE DEC 09 2008
VALID 091300Z - 101200Z
...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF NRN LA AND SRN AND
CENTRAL MS...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS
VALLEY...
...SYNOPSIS...
MAJOR TROUGH CONTINUES TO EVOLVE OVER CENTRAL U.S. LEAD S/WV HAS
RACED RAPIDLY NEWD FROM SRN PLAINS TO LOWER MO VALLEY OVERNIGHT WITH
STRONG WIND MAX/TROUGH CONTINUING TO DIG SEWD FROM AZ/NM INTO S TX
TONIGHT. THIS WILL MAINTAIN A STRONG SWLY FLOW FROM S TX TO LOWER
MS VALLEY INTO TONIGHT. COLD FRONT WRN MO SWWD TO SWRN TX WILL
CONTINUE SEWD MOVING OFFSHORE TX COAST LATER THIS EVENING.
LOW LEVEL MOISTURE FROM WRN GULF CONTINUES TO INCREASE NWD THRU ERN
TX INTO LOWER MS VALLEY TODAY IN ADVANCE OF THE COLD FRONT. ACTIVE
THUNDERSTORMS INCLUDING SUPERCELLS CONTINUE TO DEVELOP WELL IN
ADVANCE OF THE COLD FRONT IN THE ZONE OF FAVORABLE SHEAR AND
INSTABILITY.
...LOWER MS VALLEY...
BASED ON GREATER INSTABILITY THAN EARLIER EXPECTED A SMALL AREA OF
LA AND MS HAS BEEN UPGRADED TO A MDT RISK.
VERY STRONG SHEAR PROFILES EXPECTED TO REMAIN IN PLACE MUCH OF LOWER
MS VALLEY THRU THE DAY...SUPPORTIVE OF ORGANIZED THUNDERSTORMS
INCLUDING POTENTIAL TORNADIC SUPERCELLS. WARM SECTOR AIR MASS WILL
SPREAD NWD THRU ERN AR/MS AS 50-60KT SLY LLJ SHIFTS SLOWLY EWD FROM
LA/AR INTO MS/WRN TN BY THIS EVENING. DEWPOINTS RISING INTO LOW/MID
60S THRU LA INTO SRN HALF OF MS...WILL LEAD TO MLCAPES FROM
1000-1500 J/KG. THIS IS SUPPORTED BY THE 12Z LCH SOUNDING
CHARACTERIZED BY STEEP MID LEVEL LAPSE RATES AND MLCAPE IN EXCESS OF
1500 J/KG. LESSER INSTABILITY FURTHER N IN WARM SECTOR SUCH THAT
MUCH OF SEVERE THREAT WILL BE MAINLY S OF A CENTRAL AR/NRN MS LINE.
ONGOING STRONG/SEVERE THUNDERSTORMS FROM AR SWWD INTO ERN TX/NWRN LA
WILL SPREAD EWD WITH INCREASING THREAT OF TORNADIC SUPERCELLS...
PARTICULARLY NRN LA/FAR SRN AR INTO W CENTRAL MS WHERE STRONG
TORNADOES ARE POSSIBLE BY THIS AFTERNOON. THUNDERSTORMS WILL TEND
TO DEVELOP INTO MORE OF A LINE LATER THIS AFTERNOON AS THEY MOVE EWD
ACROSS LOWER MS VALLEY. PRIMARY THREAT WITH A LINEAR MODE WILL BE
DAMAGING WINDS AND HAIL. INTENSITY SHOULD GRADUALLY DIMINISH AS
STORMS BEGIN TO OUTRUN FAVORABLE LOW LEVEL INSTABILITY TN VALLEY SWD
THIS EVENING. HOWEVER SEVERE THREAT WILL LIKELY CONTINUE AFTER DARK
ACROSS PARTS OF MS.
..HALES.. 12/09/2008
Posts
No comments:
Post a Comment