SWODY1
SPC AC 151955
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT THU APR 15 2010
VALID 152000Z - 161200Z
...NO SVR TSTM AREAS FORECAST...
...UPPER GREAT LAKES...
LOW SEVERE HAIL AND WIND PROBABILITIES ARE BEING MAINTAINED ACROSS
THIS REGION WITH THE AREA EXTENDED A LITTLE SWD ACROSS CENTRAL WI
WHERE WEAK INSTABILITY AND SRN EXTENT OF STRONGER EFFECTIVE BULK
SHEAR IS PRESENT PER OBJECTIVE ANALYSES. OTHERWISE...FORECAST
REMAINS ON TRACK ACROSS THIS REGION...GIVEN WEAK INSTABILITY
PRECLUDING A GREATER SEVERE WEATHER THREAT. GENERAL TSTM LINE HAS
BEEN SHIFTED EWD ACROSS MUCH OF ERN AND SOUTH CENTRAL MN GIVEN
CONTINUED EWD PROGRESSION OF COLD FRONT...AND SUBSEQUENT INTRUSION
OF DRIER POST-FRONTAL AIR MASS.
...PORTIONS OF CENTRAL NEB AND NERN AR/SERN MO AND SRN IL...
GENERAL TSTM AREA HAS BEEN EXPANDED ACROSS THESE AREAS GIVEN TRENDS
IN RADAR/SATELLITE IMAGERY AND LIGHTNING DATA. WEAK INSTABILITY AND
VERY WEAK SHEAR PRECLUDES THE NEED TO ADD ANY SEVERE WEATHER
PROBABILITIES.
...SRN APPALACHIANS...
REGIONAL RADARS/SATELLITE IMAGERY AND LIGHTNING DATA SHOWED CU AND A
FEW TSTMS HAVE DEVELOPED ACROSS THE SRN EXTENT OF THE APPALACHIANS.
AREA WSR-88D VWPS INDICATED FAVORABLE UPSLOPE...THOUGH GENERALLY
WEAK...WITHIN A WEAKLY UNSTABLE AIR MASS SUPPORTING THESE DIURNALLY
DRIVEN CU/CBS.
...ELSEWHERE...
NO CHANGES NEEDED ACROSS THE REMAINDER OF THE GENERAL TSTM AREAS AND
CENTRAL HIGH PLAINS AND S TX LOW SEVERE PROBABILITY AREAS.
..PETERS.. 04/15/2010
.PREV DISCUSSION... /ISSUED 1119 AM CDT THU APR 15 2010/
...UPPER GREAT LAKES...
STRONG TROUGH MANITOBA TO UPPER MS VALLEY WILL CONTINUE E DRIVING A
COLD FRONT CURRENTLY MN ACROSS UPPER GREAT LAKES BY THIS EVENING.
ALTHOUGH STRONG SHEAR PROFILES SUPPORT ORGANIZED CONVECTION
ASSOCIATED WITH THE COLD FRONT ACROSS NRN WI/UPPER MI THIS
AFTERNOON...THE SUPPORTING WARM SECTOR AIR MASS IS EXPECTED TO BE
DEFICIENT OF INSTABILITY FOR ANY SIGNIFICANT SEVERE THUNDERSTORM
THREAT. WITH HEATING MLCAPES COULD CLIMB TO 500 J/KG NERN WI INTO
UPPER MI WHICH SHOULD LEAD TO ISOLATED STRONG/SEVERE STORMS CAPABLE
OF HAIL AND GUSTY WINDS.
FURTHER S AHEAD OF THE FRONT INSTABILITY AND SHEAR WILL BE EVEN
LESS...WITH ANY FRONTAL THUNDERSTORM DEVELOPMENT EXPECTED TO REMAIN
BELOW SEVERE.
...CENTRAL HIGH PLAINS...
AS COLD FRONT NOW INTO NWRN KS/ERN CO CONTINUES SWD IT WILL INTERACT
WITH THE DEEPER PLUME OF MOISTURE STREAMING NWD FROM THE SRN HI
PLAINS. CLOUDS WILL SOMEWHAT LIMIT THE HEATING AHEAD OF THE
FRONT...BUT MID LEVEL LAPSE RATES AROUND 7C/KM AND DEWPOINTS INTO
THE MID/UPPER 50S WILL PROVIDE ENOUGH INSTABILITY FOR A FEW
STRONG/MARGINALLY SEVERE STORMS THIS AFTERNOON ALONG THE COLD FRONT.
IN THIS AREA SHEAR IS WEAK SO ANY STRONG UPDRAFT WILL BE OF SHORT
DURATION AND LIMITED TO THE AFTERNOON/EARLY EVENING PRIOR TO
CESSATION OF SURFACE HEATING.
...S TX...
INTRODUCTION OF A LOW TORNADO THREAT ACROSS S TX AT 13Z IS STILL
VALID...THUS LITTLE CHANGE.
INCREASINGLY MOIST /PW AOA 1.5 INCHES/ 2-3 KM DEEP ESELY FLOW WILL
CONTINUE ACROSS THE LWR RIO GRANDE VLY OF S TX THROUGH THIS
EVE...AHEAD OF SLOWLY-MOVING W TX UPR VORT. PERSISTENT
REDEVELOPMENT OF DEEP CONVECTION WITHIN THIS REGIME ALREADY HAS
RESULTED IN THE DEVELOPMENT OF A LOOSELY-ORGANIZED MCV-TYPE
CIRCULATION NEAR DRT. WITH MOIST UPSLOPE CONTINUING...DAYTIME
DESTABILIZATION MAY BE SUFFICIENT FOR SOME INCREASE IN UPDRAFT
STRENGTH/CELL LONGEVITY ALONG NRN AND ERN FRINGE OF THE MCV. GIVEN
CONSIDERABLE DEGREE OF LOW-LVL VEERING LIKELY TO PERSIST OVER
REGION...POTENTIAL WILL EXIST FOR ISOLD STORMS TO BRIEFLY ASSUME
LOW-LVL CIRCULATIONS. THESE COULD POSE A LOW PROBABILISTIC THREAT
FOR A TORNADO.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment