ACUS3 KMKC 121256
SWOMCD
MKC MCD 121256
TXZ000-LAZ000-121500-
SPC MESOSCALE DISCUSSION 0277 FOR CNTRL/SRN LA THROUGH SERN TX
CONCERNING...SEVERE THUNDERSTORM POTENTIAL AND HEAVY RAINFALL...REF
WW 57...
THREAT FOR ISOLATED DAMAGING WIND GUSTS CONTINUES WITH LINE MOVING
EWD THROUGH SERN TX AND NRN/CNTRL LA. LOCALLY HEAVY RAINFALL IS
LIKELY FROM SERN TX THROUGH SWRN LA.
SQUALL LINE HAS BECOME ORIENTED MORE PARALLEL TO UPPER FLOW AND HAS
SLOWED ITS MOVEMENT SOMEWHAT...SUGGESTING DAMAGING WIND THREAT MAY
LESSEN WITH TIME. SRN PORTION OF LINE IS MOVING EWD AT AROUND 30 KT
WHILE NRN PORTION IS MOVING EWD NEAR 40 KT. LOCALLY DAMAGING WIND
GUSTS REMAIN POSSIBLE...ESPECIALLY WITH FASTER MOVING NRN PORTION
OF LINE.
LINE HAS BECOME ORIENTED IN A MORE FAVORABLE POSITION FOR STORMS TO
TRAIN SW-NE FOR A WHILE AND RESULT IN RAINFALL RATES OF UP TO 1.5
INCHES PER HOUR FROM SERN TX THROUGH SWRN LA. MORNING SOUNDINGS
SHOW ATMOSPHERE TO BE MOIST THROUGH A DEEP LAYER ACROSS SRN LA
WHICH SHOULD LESSEN STRENGTH OF OUTFLOW AND PROMOTE SLOWER LINE
MOVEMENT.
..DIAL.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 121332
SWOMCD
MKC MCD 121332
LAZ000-MSZ000-ALZ000-121600-
SPC MESOSCALE DISCUSSION 0278 FOR SERN LA...SRN MS AND SWRN AL
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
WIDELY SCATTERED SUPERCELL STORMS CAPABLE OF PRODUCING LARGE HAIL
AND DAMAGING WIND GUSTS WILL CONTINUE ACROSS AREA NEXT FEW HOURS.
AN ISOLATED TORNADO OR TWO MAY ALSO BE POSSIBLE.
WIDELY SCATTERED SUPERCELLS CONTINUE PRIMARY ALONG AND N OF COASTAL
BOUNDARY EXTENDING FROM CNTRL LA SEWD THROUGH SERN LA AND INTO THE
GULF COAST. STRONGEST STORM IS OVER SERN LA IN TANGIPAHOA COUNTY
MOVING NEWD AT AROUND 45 KT. STRONG STORM RELATIVE HELICITY AND
PROXIMITY TO BOUNDARY SUGGEST THIS STORM MAY BE CAPABLE OF
PRODUCING A TORNADO. THIS STORM WILL LIKELY CROSS INTO SWRN MS
BEFORE 14Z. DAMAGING WIND SHOULD BE PRIMARY THREAT WITH SQUALL LINE
AS IT CROSSES INTO WW 58 ACROSS PORTIONS OF SWRN MS AND SERN LA
WITHIN NEXT HOUR.
..DIAL.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 121537
SWOMCD
MKC MCD 121536
MSZ000-121630-
SPC MESOSCALE DISCUSSION 0279 FOR SERN MS/SERN LA
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...SEVERE THUNDERSTORM
WATCH 058...
..TORNADO THREAT INCREASING ACROSS SERN MS AND SRN LA...
LINE OF STORMS FROM 40 E OF JAN TO 40 E MCB CONTINUES TO MOVE ESEWD
AT 45 KT. MORE CELLULAR STORMS ARE LOCATED ABOUT 70 MILES SE OF JAN
MOVING NEWD AT 45 KT. THESE STORMS ARE LOCATED NEAR THE WARM FRONT
AND THE LINE WILL COLLIDE WITH THESE STORMS WITHIN THE NEXT HOUR IN
OR NEAR SMITH/COVINGTON/JASPER/JONES COUNTIES. WINDS AT HBG ARE
SELY AND HAVE INCREASED IN SPEED WITH THE LOWEST PRESSURE LOCATED
NEAR THIS OBSERVATION POINT. THE MERGER OF THESE TWO SYSTEMS AND
STRONG SHEAR INDICATES A GREATER POTENTIAL OF TORNADOES IN THIS
AREA DURING THE NEXT HOUR.
STORMS ARE GRADUALLY BECOMING CELLULAR ALONG THE LINE FROM BTR TO
40 WSW LUL. SBCAPES AROUND 2000 J/KG AND STRONG SHEAR SUGGESTS THAT
THE TORNADO THREAT WILL INCREASE WITH THIS LINE AS IT MOVES ESEWD
AT 40-50 KT.
..IMY.. 03/12/01
000
ACUS3 KMKC 121551
SWOMCD
MKC MCD 121550
MNZ000-WIZ000-MIZ000-122000-
SPC MESOSCALE DISCUSSION 0280 FOR E-CENTRAL MN...CENTRAL/NRN WI...
UPPER MI
CONCERNING...WINTER MIXED PRECIPITATION...
SNOWFALL RATES OF 1 IN/HR ARE EXPECTED AT TIMES THROUGH THE
AFTERNOON HOURS FROM E-CENTRAL MN EWD ACROSS CENTRAL/NRN WI AND
UPPER MI. SNOW WILL LIKELY MIX WITH SLEET AND FREEZING RAIN BY
EARLY AFTERNOON IN VICINITY OF GREEN BAY.
SURFACE CYCLONE CENTERED OVER N-CENTRAL IA AT 12/15Z CONTINUES TO
MOVE NNEWD AND DEEPEN AT A RATE OF 0.5-1 MB/HR IN STRONGLY
DIFFLUENT UPPER TROPOSPHERIC FLOW. THE SYNOPTIC-SCALE WARM FRONT
EXTENDS SEWD ACROSS CENTRAL IL...WITH STRONG LOW-LEVEL WARM-AIR
ADVECTION ACROSS CENTRAL/SRN WI EXPECTED TO CONTINUE DURING THE
NEXT SEVERAL HOURS. ALTHOUGH A DRY SLOT IS DEVELOPING INTO EXTREME
SRN MN AT THE PRESENT TIME...VISIBLE SATELLITE IMAGERY INDICATES A
DEFORMATION ZONE STRENGTHENING IN THE NWRN QUADRANT OF THE SURFACE
LOW...WHICH WILL BRING A PERSISTENT BAND OF MODERATE TO
OCCASIONALLY HEAVY SNOW FROM 20 N RWF TO 70 NE MSP THROUGH MID-
AFTERNOON. FURTHER EAST...STRONG WARM AIR ADVECTION/UVV WILL
SUPPORT MODERATE TO OCCASIONALLY HEAVY SNOW ACROSS CENTRAL/NRN WI
AND UPPER MI. THERMAL STRATIFICATION WILL BECOME MORE FAVORABLE FOR
SLEET/FREEZING RAIN AROUND 12/18-19Z IN GREEN BAY VICINITY...WHILE
VERTICAL PROFILE WILL CONTINUE TO SUPPORT SNOW FURTHER NORTH AND
WEST.
..BANACOS.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 121614
SWOMCD
MKC MCD 121614
ALZ000-FLZ000-121900-
SPC MESOSCALE DISCUSSION 0281 FOR SRN AL AND FL PANHANDLE
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
...TORNADO WATCH LIKELY WILL BE ISSUED FOR THE REMAINDER OF SRN AL
AND THE FL PANHANDLE IN THE NEXT 1 TO 2 HOURS.
AT 16Z...WARM FRONT EXTENDED FROM NEAR LUL SEWD TO BETWEEN MOB/CEW.
AIR MASS TO THE SOUTH OF THE WARM FRONT HAS WARMED INTO THE LOWER
70S AND WITH MID LEVEL LAPSE RATES AROUND 7.0-7.5C/KM...SBCAPES
HAVE INCREASED TO NEAR 2000 J/KG. WARM FRONT IS EXPECTED TO LIFT
SLOWLY NWD AS LINE OF STORMS MOVES RAPIDLY EWD AT 45-50 KT INTO WRN
AL BY 17Z. THE STRONG LIFT ASSOCIATED WITH THE UPPER LEVEL TROUGH
OVER THE CENTRAL U.S. WILL ALSO RESULT IN NUMEROUS STORMS TO
DEVELOP AHEAD OF THE LINE. GIVEN THE VERY STRONG SHEAR AND MODERATE
INSTABILITY...A NEW WEATHER WATCH WILL LIKELY BEFORE 18Z FOR THE
REMAINDER OF SRN AL AND THE WRN/CENTRAL FL PANHANDLE.
..IMY.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 121640
SWOMCD
MKC MCD 121639
MSZ000-121715-
SPC MESOSCALE DISCUSSION 0282 FOR SERN MS/EXTREME WRN CENTRAL AL...
CONCERNING...SEVERE THUNDERSTORM WATCH 060...
...INCREASED TORNADO THREAT FROM WEST CENTRAL AL SEWD ACROSS SERN
MS...
SURFACE LOW WAS LOCATED NEAR HBG IN SERN MS WITH A WARM FRONT
EXTENDING SEWD TO NEAR CEW. SLY WINDS HAVE INCREASED TO 20-25 KT IN
THE WARM SECTOR AND THE STRONG AND VEERING WINDS WITH HEIGHT ARE
RESULTING IN STORM RELATIVE HELICITIES AROUND 400 M**2/S**2. THE
LINE OF STORMS HAS DEVELOPED SEVERAL SMALL CIRCULATIONS ALONG THE
LEADING EDGE AND IS MOVING EWD AT 50-60 KT WITH A HIGH LIKELIHOOD
OF WIND DAMAGE AND ISOLATED TORNADOES. ALSO...STORMS ARE DEVELOPING
AHEAD OF THE LINE AND MERGERS WOULD INCREASE THREAT OF TORNADOES.
THE STRENGTH OF THE DEEP LAYER SHEAR...PLUS INCREASED LOW LEVEL
SHEAR NEAR THE WARM FRONT...ALSO INDICATES A RISK OF ISOLATED
STRONG TORNADOES.
..IMY.. 03/12/01
000
ACUS3 KMKC 121657
SWOMCD
MKC MCD 121656
ALZ000-MSZ000-121800-
SPC MESOSCALE DISCUSSION 0283 FOR EAST CENTRAL MS/ WEST CENTRAL AL
CONCERNING...SEVERE THUNDERSTORM WATCH 059...
...STORMS INCREASING IN ALABAMA PORTION OF SEVERE THUNDERSTORM
WATCH 59...BUT WEAKENING IN EAST CENTRAL MS....
LINE HAS WEAKENED AS IT HAS MOVED EWD INTO EAST CENTRAL MS. THE
WEAKENING IN EAST CENTRAL MS IS IN RESPONSE TO THE LINE
STRENGTHENING IN SERN MS. HOWEVER...STORMS THAT DEVELOPED EARLIER
IN SERN MS ARE LOCATED NORTH OF THE WARM FRONT IN WEST CENTRAL AL
AND HAVE INTENSIFIED IN THE PAST HOUR. THE STORM UPDRAFT ROOTS ARE
LOCATED ABOVE THE SHALLOW COOL BOUNDARY LAYER...BUT ARE EMBEDDED IN
MODERATE INSTABILITY ALOFT AND STRONG SHEAR. THESE STORMS ARE
LIKELY TO INCREASE IN INTENSITY WITH LARGE HAIL EXPECTED WITH
STORMS THAT ACQUIRE MID LEVEL ROTATION. DESPITE THE SHALLOW COOL
BOUNDARY LAYER...THE STRONG DOWNDRAFTS MAY ALSO BE ABLE TO
PENETRATE THE SHALLOW STABLE BOUNDARY LAYER TO RESULT IN DAMAGING
WINDS.
..IMY.. 03/12/01
000
ACUS3 KMKC 121745
SWOMCD
MKC MCD 121744
GAZ000-FLZ000-122000-
SPC MESOSCALE DISCUSSION 0284 FOR SRN GA AND FL PANHANDLE...
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
...WEATHER WATCH MAY BE NEEDED FOR PORTIONS OF SRN GA AND THE
REMAINDER OF FL PANHANDLE BY 20Z...
SMALL CLUSTER OF LONG LIVED STORMS...THAT DEVELOP EARLIER THIS
MORNING OVER SRN AL...WERE LOCATED IN SOUTH CENTRAL GA OVER
IRWIN/TIFT COUNTIES AT 1730Z. THESE STORMS ARE MOVING EWD...WELL
AHEAD OF THE STRONGER UPPER LEVEL DYNAMICS...AND THROUGH A
MARGINALLY UNSTABLE AIR MASS. THIS SMALL CLUSTER OF STORMS HAS
PRODUCED ISOLATED SEVERE HAIL...BUT THE STORMS ARE EXPECTED TO
REMAIN MOSTLY BELOW SEVERE CRITERIA GIVEN THE WEAKER INSTABILITY.
HOWEVER...STORMS IN WRN AL ARE MOVING EWD AT 50-60 KT AND SHOULD
ENTER PORTIONS OF WRN GA AFTER 20Z. OTHER STORMS HAVE DEVELOPED
OVER THE WRN FL PANHANDLE AND THESE ARE EXPECTED TO GRADUALLY
INCREASE AS THE BROAD TROUGH OVER THE CENTRAL U.S. AND STRONGER
WINDS ALOFT OVER AL/MS SHIFT EWD DURING THE AFTERNOON. ALTHOUGH
INSTABILITY IS WEAK ATTM...DEEPER BOUNDARY MOISTURE OVER SRN AL AND
WRN FL PANHANDLE WILL SHIFT EWD AHEAD OF THE THUNDERSTORM LINE. THE
INCREASING INSTABILITY AND DEEP LAYER SHEAR SUGGESTS THAT A WATCH
MAY BE REQUIRED FOR PORTIONS OF SRN GA AND THE REMAINDER OF THE FL
PANHANDLE BY 20Z.
..IMY.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 121805
SWOMCD
MKC MCD 121804
ALZ000-MSZ000-LAZ000-FLZ000-121900-
SPC MESOSCALE DISCUSSION 0285 FOR SERN LA...EXTREME SERN MS AND SRN
AL AND WRN FL PANHANDLE...
CONCERNING...TORNADO WATCH 060...061...
DURING THE PAST HOUR...STORM DEVELOPMENT AHEAD OF THE LINE HAS
CEASED AND THE LINE HAS BECOME LESS CELLULAR. HOWEVER...SEVERAL
CIRCULATIONS ARE OBSERVED IN THE RADAR DATA AND THE EMBEDDED BOWS
AND LEWPS INDICATE A CONTINUED TORNADO THREAT. THE LIKELIHOOD FOR
WIDESPREAD WIND DAMAGE ALSO IS LIKELY...ESPECIALLY ACROSS SRN
AL/WRN FL PANHANDLE WHERE THE LINE IS ADVANCING EWD AT 55 KT.
GREATEST BOWING AND STRONGEST WINDS ARE LIKELY WITHIN THE NEXT HOUR
ACROSS CONECUH AND ESCAMBIA COUNTIES IN AL AND SANTA ROSA COUNTY IN
WRN FL PANHANDLE.
THE LINE ACROSS SERN LA IS MOVING 30 SEWD AT 20-30 KT...MAINLY DUE
TO PROPAGATIONAL DEVELOPMENT. A THREAT OF LARGE HAIL AND DAMAGING
WINDS ARE POSSIBLE WITH SOME OF THESE STORMS.
..IMY.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 121854
SWOMCD
MKC MCD 121854
ARZ000-122100-
SPC MESOSCALE DISCUSSION 0286 FOR AR
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
...WW MAY BE NEEDED FOR PORTIONS OF AR BY 21Z...
DECREASING CLOUDS IN THE PAST FEW HOURS HAVE ALLOWED TEMPERATURES
TO WARM INTO THE 60S ACROSS MOST OF ARKANSAS. THESE TEMPERATURES...
WITH DEWPOINTS IN MID AND UPPER 50S...AND MODERATELY STEEP LAPSE
RATES ARE RESULTING IN 500-1000 J/KG OF MUCAPE. WITH MORE HEATING
THE INSTABILITY WILL INCREASE AND A WEAK COLD FRONT...FROM NEAR HRO
TO SOUTH OF FSM...IS EXPECTED TO PROVIDE SUFFICIENT FOCUS FOR
CONVECTION. ALTHOUGH FORECAST SOUNDINGS SHOW UNIDIRECTIONAL WSWLY
VERTICAL WIND PROFILES...THE SPEED SHEAR WILL RESULT IN SUFFICIENT
DEEP LAYERED SHEAR FOR SEVERE STORMS. THE LOW WET BULB ZERO
HEIGHTS...AROUND 6000 FEET...SUGGEST THAT LARGE HAIL WILL BE THE
PRIMARY THREAT. HOWEVER...WATER VAPOR IMAGERY SHOWS DRIER AIR ALOFT
HAS SPREAD NEWD ACROSS AR. ALSO...FORECAST SOUNDINGS SHOW DRY AIR
MASS FROM 700-300 MB...INDICATING A THREAT OF DAMAGING WINDS ALSO.
CONVECTIVE INITIATION IS EXPECTED BY MID AFTERNOON AND A SEVERE
THUNDERSTORM WATCH MAY BE NEEDED BY 21Z.
..IMY.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
NNNN
000
ACUS3 KMKC 121932
SWOMCD
MKC MCD 121931
ALZ000-LAZ000-MSZ000-FLZ000-122030-
SPC MESOSCALE DISCUSSION 0287 FOR EXTREME SERN LA/COASTAL MS/
SRN AL AND WRN FL PANHANDLE
CONCERNING...TORNADO WATCH 060...061...
...SIGNIFICANT WIND DAMAGE AND ISOLATED TORNADOES EXPECTED ACROSS
SRN AL DURING THE NEXT COUPLE OF HOURS...
STRONG LINE OF STORMS MOVING EWD AT 50 KT EXTENDED FROM W OF TOI TO
25 W PNS. AN AREA OF LOW PRESSURE WAS LOCATED NEAR THE INTERSECTION
OF THE THUNDERSTORM LINE AND WARM FRONT...WHICH EXTENDED FROM NEAR
TOI SEWD TO NEAR TLH. A STRONG PERSISTENT CYCLONIC CIRCULATION HAS
ALSO BEEN INDICATED ON RADAR NEAR THE WARM FRONT/THUNDERSTORM LINE
INTERSECTION AND MAY BE RESULTING IN SIGNIFICANT DAMAGE NEAR THIS
FEATURE AND SOUTHWARD IN THE STRONGLY BOWING PORTION OF THE LINE.
SIGNIFICANT DAMAGE HAS BEEN REPORTED IN EVERGREEN IN SOUTH CENTRAL
WITH THIS FEATURE. STORM RELATIVE HELICITIES NEAR THE WARM FRONT
ARE IN EXCESS OF 500 M**2/S**2 AND A TORNADO THREAT CONTINUES WITH
THE LINE. WIDESPREAD SIGNIFICANT WIND DAMAGE WILL BE POSSIBLE IN
SOUTH CENTRAL AL WITH THE GREATEST THREAT OF WIND DAMAGE IN THE
NEXT HOUR IN COFFEE... PIKE...AND GENEVA COUNTIES IN AL...AND
OKALOOSA AND WALTON COUNTIES IN WRN FL.
ISOLATED SEVERE THUNDERSTORMS REMAIN POSSIBLE IN EXTREME SERN LA
AND COASTAL MS.
..IMY.. 03/12/01
000
ACUS3 KMKC 122056
SWOMCD
MKC MCD 122055
ARZ000-MOZ000-122300-
SPC MESOSCALE DISCUSSION 0288 FOR CENTRAL/NRN AR AND SERN MO
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
..MONITORING PORTIONS OF CENTRAL/NRN AR AND SERN MO FOR POSSIBLE
SEVERE THUNDERSTORM WATCH...
A COLD FRONT CONTINUES TO MOVE SLOWLY SEWD ACROSS NWRN AR AND IS
PROVIDING WEAK CONVERGENCE FROM ABOUT 60 NW CGI TO HRO SWWD INTO
WEST CENTRAL AR. A FEW SHOWERS HAVE DEVELOPED IN NORTH CENTRAL AR/S
CENTRAL MO...BUT VISIBLE SATELLITE INDICATES STRONG SPEED SHEAR MAY
BE PREVENTING UPDRAFTS IN WEAK INSTABILITY FROM BECOMING ORGANIZED.
HOWEVER...WITH A FEW MORE DEGREES OF HEATING...STORMS MAY BE ABLE
TO DEVELOP AND THE LOW WET BULB ZERO HEIGHTS AND DEEP LAYER SHEAR
WOULD BE SUPPORTIVE OF STORMS WITH LARGE HAIL AND DAMAGING WIND
GUSTS. THREAT FOR SEVERE IN SRN AR APPEARS MINIMAL AS THE WINDS
HAVE BECOME MORE SWLY BEHIND A WEAK WIND SHIFT SURFACE TROUGH.
WILL MONITOR AREA FROM CENTRAL AR NEWD INTO SERN MO FOR
THUNDERSTORM DEVELOPMENT. IF STORM UPDRAFTS CAN BECOME SUSTAINED...
SEVERE THUNDERSTORM WATCH MAY BE NEEDED.
..IMY.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
NNNN
000
ACUS3 KMKC 122319
SWOMCD
MKC MCD 122318
SCZ000-FLZ000-GAZ000-130200-
SPC MESOSCALE DISCUSSION 0289 FOR SERN GA/NRN FL/SRN SC
CONCERNING...TORNADO WATCH 0062...
SQUALL LINE CONTINUES TO DECELERATE AS IT PROPAGATES EWD ACROSS
CENTRAL PORTIONS OF WW...WITH ESTIMATED SPEED AROUND 25-30 KT. IT
APPEARS ACTIVITY MAY NOT EXIT ERN PORTIONS OF TORNADO WATCH BEFORE
EXPIRATION. WITH TIME THERE MAY BE A NEED TO REPLACE PORTIONS OF
THE WATCH ACROSS GA AND FL.
CURRENT WEDGE OF COOLER BOUNDARY LAYER AIR IS VERY SLOWLY LIFTING
NWD ACROSS ERN GA INTO COASTAL SC. THIS AIR MASS MAY NOT RECOVER
AHEAD OF SQUALL LINE...POTENTIALLY LIMITING DAMAGING WIND THREAT
NORTH OF THE BOUNDARY. SOUTH OF THIS FRONT...STRONG VERTICAL SHEAR
WILL SUPPORT EMBEDDED DAMAGING BOWS WITH SOME THREAT FOR ISOLATED
TORNADOES AS SQUALL LINE MOVES EWD. WITH TIME SRN EDGE OF LINE MAY
SLOW ENOUGH TO WARRANT INCREASED RISK OF HEAVY RAIN.
..DARROW.. 03/12/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 130436
SWOMCD
MKC MCD 130436
NYZ000-PAZ000-131000-
SPC MESOSCALE DISCUSSION 0291 FOR EXTREME NERN PA / CENTRAL AND
SERN NY
CONCERNING...FREEZING RAIN...
FREEZING RAINFALL RATES AROUND 0.1 INCH PER HOUR ARE EXPECTED TO
DEVELOP NEWD OVER EXTREME NERN PA INTO SOUTH CENTRAL AND PORTIONS
OF SERN NY AFTER 13/06-07Z AND CONTINUE THROUGH ABOUT 13/10Z.
DRY LOW-MID LEVELS OVER NY PER 00Z SOUNDINGS CONTINUE TO SATURATE
AS MOISTURE AND ABOVE 0 C AIR ADVECTS NNEWD ON A 50+ KT SLY LLJ
WHICH EXTENDS FROM VA TO BGM. REGIONAL RADARS SHOW MODERATE TO
HEAVY RAINFALL FROM ERN MD NWD INTO ERN PA WITH RAINFALL RATES
RANGING FROM 0.1-0.2 INCH PER HOUR. LATEST SURFACE ANALYSIS SHOWS
WET-BULB TEMPERATURES OVER THE AREA OF CONCERN IN THE MID-UPPER
20S. WITH SURFACE DEWPOINT DEPRESSIONS RANGING FROM 13-18
DEGREES...EVAPORATIVE COOLING WILL ALLOW SURFACE TEMPERATURES TO
FALL BELOW THE FREEZING MARK AS THE HIGHER PRECIPITATION RATES
REACH THIS REGION. STRONG LOW-LEVEL WAA AT THE NOSE OF THE LLJ
COMBINED WITH STRONG UPWARD MOTION WITH THE LEFT EXIT REGION OF AN
UPPER JET APPROACHING FROM THE LOWER MS/TN VALLEYS WILL ENHANCE THE
PRECIPITATION RATES OVERNIGHT. THE ELEVATED WARM LAYER IS EXPECTED
TO REMAIN OVER THIS REGION THROUGH AT LEAST 13/11Z SUPPORTING
FREEZING RAIN.
..PETERS.. 03/13/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 130728
SWOMCD
MKC MCD 130727
FLZ000-GAZ000-131100-
SPC MESOSCALE DISCUSSION 0292 FOR THE ERN FL PANHANDLE...NRN FL
PENINSULA AND SERN GA
CONCERNING...HEAVY RAINFALL...SEVERE THUNDERSTORM POTENTIAL...
RAINFALL RATES UP TO 2 INCHES PER HOUR POSSIBLE THROUGH 11Z. AN
ISOLATED TORNADO OR TWO MAY ALSO BE POSSIBLE WITH ANY STRONGLY
ROTATING DISCRETE CELL WITHIN THE LINE. UNLESS STORMS SHOW SIGNS
OF INTENSIFICATION...WW IS CURRENTLY NOT ANTICIPATED.
OUTFLOW BOUNDARY EXTENDS FROM THE NERN GULF THROUGH THE NRN FL
PENINSULA AND INTO SERN GA. STORMS CONTINUE DEVELOPING ALONG AND
N OF OUTFLOW SUPPORTED BY STRONG SWLY FLOW EMANATING FROM MOIST
AND UNSTABLE AIR OVER THE GULF. SWLY LOW TO MID LEVEL FLOW PARALLEL
TO LINE AND DEEP...MOIST THERMODYNAMIC PROFILES SHOULD LIMIT LINE
MOVEMENT...WHILE INDIVIDUAL CELLS TRAIN NEWD ALONG THE LINE.
PRECIPITABLE WATER VALUES FROM 1.5 TO 1.8 INCHES AND MODERATE
INSTABILITY OVER THE GULF WILL SUPPORT RAINFALL RATES IN EXCESS OF
1.5 INCHES PER HOUR AS STORMS WITHIN LINE TRAIN NEWD.
SHEAR PROFILES REMAIN SUPPORTIVE OF UPDRAFT ROTATION AND SEVERAL
CELLS WITHIN THE LINE CONTINUE TO ROTATE. LATEST VWP DATA SHOW
STORM RELATIVE HELICITY VALUES FROM 200 TO 300 M2/S2. THIS ALONG
WITH LOW LCLS SUGGEST AN ISOLATED TORNADO OR TWO MAY BE POSSIBLE
WITH ANY STRONGLY ROTATING DISCRETE CELL. HOWEVER...GIVEN WEAK
THERMODYNAMIC PROFILES WW IS NOT ANTICIPATED AT THIS TIME.
..DIAL.. 03/13/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 131105
SWOMCD
MKC MCD 131105
NCZ000-131300-
SPC MESOSCALE DISCUSSION 0293 FOR ERN NC
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...
LINE OF STORMS HAS INTENSIFIED ACROSS ERN NC. AN ISOLATED STRONG
WIND GUST OR TWO MAY BE POSSIBLE NEXT COUPLE HOURS WITH ANY LEWP
AND BOW ECHO STRUCTURES THAT DEVELOP WITHIN THE LINE. HOWEVER...
SEVERE POTENTIAL APPEARS MARGINAL.
SHALLOW SQUALL LINE HAS DEVELOPED ALONG A LOW LEVEL CONVERGENCE
AXIS AND EXTENDS FROM EXTREME SERN VA SWWD INTO ERN NC JUST E OF
GOLDSBORO. LINE IS MOVING SLOWLY EWD WHILE INDIVIDUAL CELLS WITHIN
THE LINE MOVE MORE RAPIDLY NEWD. BUOYANCY IS QUITE LIMITED RELATIVE
TO THE AMOUNT OF SHEAR SO UPDRAFTS ARE EXPECTED TO REMAIN WEAK AND
SHEARED TO THE NE. ACTIVITY IS EMBEDDED WITHIN STRONG LOW TO MID
LEVEL WIND FIELDS WITH SPEEDS UP TO 50 KT BETWEEN 1 AND 3 KM.
HOWEVER...FLOW IS MOSTLY PARALLEL TO LINE. FLOW IS EXPECTED TO
GRADUALLY VEER WITH TIME...POSSIBLY RESULTING IN EWD ACCELERATION
OF LINE. AN ISOLATED STRONG WIND GUST MAY BE POSSIBLE BEFORE LINE
MOVES OFFSHORE LATER THIS MORNING. HOWEVER...THREAT FOR AN
ORGANIZED SEVERE EVENT APPEARS VERY MARGINAL.
..DIAL.. 03/13/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
000
ACUS3 KMKC 131211
SWOMCD
MKC MCD 131210
MAZ000-NHZ000-VTZ000-MEZ000-131700-
SPC MESOSCALE DISCUSSION 0294 FOR WRN AND CENTRAL MA/SRN VT/PARTS
OF NH AND ME
CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION...
FREEZING RAIN WILL GRADUALLY CHANGE OVER TO RAIN WHILE DIMINISHING
IN COVERAGE AND INTENSITY ACROSS WRN AND CENTRAL MA/FAR SRN VT AND
NH THROUGH 13/14Z. ONGOING LIGHT SNOW ACROSS THE REST OF SRN NH AND
FAR SRN ME WILL CHANGE OVER TO FREEZING RAIN AND SLEET WITH
FREEZING RAIN RATES FROM 0.05 TO 0.15 INCHES PER HOUR FOR A 2 TO 3
HOUR PERIOD...THROUGH 13/16Z. SNOWFALL WILL CONTINUE TO DEVELOP
ACROSS THE REMAINDER OF ME WITH SNOWFALL BECOMING OCCASIONALLY
HEAVY ACROSS PORTIONS INTERIOR ME/NERN NH THROUGH 13/16Z.
LATEST IR/WV IMAGERY INDICATES PRONOUNCED DRY SLOT MOVING INTO
PORTIONS OF SRN NEW ENGLAND...WHICH WAS DIMINISHING PRECIP COVERAGE
AND INTENSITY RAPIDLY FROM THE SW. 11Z SURFACE ANALYSIS INDICATED
THAT SURFACE WET BULB ZERO LINE EXTENDED FROM NEAR BOS SWWD TO JUST
NORTH OF HFD. VWP OUT OF BOX INDICATES STRONG VEERING WIND PROFILE
WITH LLJ IN EXCESS OF 60 KTS...THUS AIDING IN STRONG MOISTURE
ADVECTION/LIFT CONTRIBUTING TO PRECIPITATION GENERATION ACROSS THE
AREA. PRECIPITATION WAS RAPIDLY DEVELOPING NWD INTO SRN ME AS
ATMOSPHERE CONTINUES TO QUICKLY SATURATE AND WILL CONTINUE TO
DEVELOP INTO THE REST OF ME THROUGH THE MID MORNING HOURS.
EXPECT FREEZING RAIN TO CONTINUE TO DIMINISH IN COVERAGE OVER THE
NEXT 1-2 HOURS ACROSS MA WHILE CHANGING OVER TO RAIN...AS DRY SLOT
RAPIDLY LIFTS NE. AS STRONG LLVL WAA CONTINUES INTO SRN NH AND SRN
ME SNOWFALL WILL CHANGE OVER TO A PERIOD OF 1-3 HOURS OF LIGHT TO
MODERATE FREEZING RAIN BETWEEN 13/13Z AND 13/16Z BEFORE PRECIP
DIMINISHES. AS REGION OF STRONGEST WAA/UVM CONTINUES TO MOVE NE
INTO PORTIONS OF CENTRAL/NRN ME AND NERN NH...THERMAL PROFILE WILL
NOT SUPPORT A CHANGEOVER FROM SNOW. THUS EXPECT PERIODS OF MODERATE
TO HEAVY SNOWFALL TO DEVELOP WITH RATES FROM 0.5 TO 1 IN PER HOUR
THROUGH 13/17Z...BEFORE DRY SLOT ENDS PRECIPITATION ACROSS AREA.
..CROSBIE.. 03/13/01
...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...