Central Indiana Skywarn

MD 0087 CONCERNING WINTER MIXED PRECIPITATION FOR PORTIONS NE TX...SERN OK...CENTRAL/SRN AR...CENTRAL/NRN LA...CENTRAL/NRN MS...EXTREME SWRN TN...EXTREME NWRN AL.
MESOSCALE DISCUSSION 0087 NWS STORM PREDICTION CENTER NORMAN OK 0528 AM CST FRI FEB 04 2011 AREAS AFFECTED...PORTIONS NE TX...SERN OK...CENTRAL/SRN AR...CENTRAL/NRN LA...CENTRAL/NRN MS...EXTREME SWRN TN...EXTREME NWRN AL. CONCERNING...WINTER MIXED PRECIPITATION VALID 041128Z - 041700Z FREEZING RAIN WITH GEN .05-.10 INCH/HOUR RATES SHOULD CONTINUE OVER BROAD SWATH FROM S-CENTRAL LA NEWD ACROSS W-CENTRAL MS...MOVING/EXPANDING NEWD OVER MORE OF N-CENTRAL AND CENTRAL MS THROUGH ABOUT 16Z. EMBEDDED CONVECTIVE BURSTS...SOME WITH THUNDER...BRIEFLY WILL OFFER .10-.25 INCH/HOUR FREEZING RAIN RATES. FREEZING RAIN WILL GRADE TO SNOW WWD ACROSS PORTIONS EXTREME N-CENTRAL/NWRN LA AND S-CENTRAL/SERN AR. SNOW RATES MAY REACH 1 INCH/HOUR IN HEAVIEST EMBEDDED BANDS AND SWATHS WWD ACROSS RED RIVER REGION OF NE TX AND SWRN OK...SWD TO NEAR I-20. BROAD PLUME OF PRECIP RELATED TO ELEVATED WAA/ASCENT AND MOISTURE TRANSPORT ALOFT IS EXPECTED TO EXPAND NEWD ACROSS ARKLATEX RETION...AR...AND MS AT FASTER RATE THAN ITS GENESIS REGION SHIFTS EWD ONLY VERY SLOWLY ACROSS LA AND E TX. LARGE-SCALE ASCENT RELATED TO DCVA...IMMEDIATELY PRECEDING MID-UPPER CYCLONE THAT IS EJECTING NEWD FROM W TX...ALSO WILL CONTRIBUTE TO ASCENT OVER WRN PORTIONS OF DISCUSSION AREA. NET EFFECT SHOULD BE EXPANSION OF ONGOING PRECIP PLUME...WHILE WET-BULB EFFECTS LEAD TO ADDITIONAL BOUNDARY-LAYER COOLING OVER MUCH OF THIS AREA. MODIFIED RUC/ETA-KF FCST SOUNDINGS INDICATE NEARLY 9 KFT DEEP SUPERFREEZING LAYER OVER PORTIONS SRN MS...TRENDING TO AROUND 4-5 KFT OVER CENTRAL LA AND DISAPPEARING OVER E TX AND NWRN LA...IN GOOD AGREEMENT WITH CURRENT TRANSITION ZONE FROM FREEZING RAIN TO SNOW. THIS TRANSITION ZONE...WHICH ALSO CORRESPONDS TO SATURATION/LIFT NEAR BASE OF DENDRITIC GROWTH LAYERS ALOFT...SHOULD DRIFT EWD ACROSS NRN LA AND SRN AR. LTG DETECTION EQUIPMENT ALSO HAS OBSERVED CG STROKES DURING PAST HOUR FROM MORE DISCRETELY CELLULAR CONVECTION FORMING INVOF POE...AND MOVING RAPIDLY NEWD BEFORE MERGING INTO BROADER PRECIP PLUME. MODIFIED FCST SOUNDINGS SUGGEST THIS ACTIVITY IS ROOTED AROUND 650 MB -- ABOVE SUPERFREEZING LAYER BUT WELL WITHIN RANGE WHERE SUPERCOOLED LIQUID DROPS ARE BEING PROCESSED THROUGH AN LFC...BENEATH MUCAPE 100-200 J/KG. ..EDWARDS.. 02/04/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BMX...HUN...MEG...JAN...LIX...LZK...LCH...SHV... TSA...FWD...OUN... LAT...LON 34579602 35029543 34829232 35198986 35028819 34568769 33688801 32348877 31139048 30559238 32039445 32519580 33629628 34579602 Read more

No Mesoscale Discussions are in effect as of Fri Feb 4 10:31:01 UTC 2011.

MD 0086 CONCERNING FREEZING RAIN FOR SWRN LA NEWD INTO W CENTRAL AND SWRN MS
MESOSCALE DISCUSSION 0086 NWS STORM PREDICTION CENTER NORMAN OK 1036 PM CST THU FEB 03 2011 AREAS AFFECTED...SWRN LA NEWD INTO W CENTRAL AND SWRN MS CONCERNING...FREEZING RAIN VALID 040436Z - 041030Z FREEZING RAIN RATES IN EXCESS OF .05"/HR SHOULD SPREAD/EXPAND ACROSS THE DISCUSSION AREA OVER THE NEXT FEW HOURS...WITH ICE ACCUMULATION ON ROADS EXPECTED TO RESULT IN HAZARDOUS TRAVEL CONDITIONS. LOW-LEVEL SLY/SWLY FLOW IN THE 850 TO 700 MB LAYER IS FORECAST TO CONTINUE INCREASING WITH TIME...AS AN UPPER TROUGH CENTERED OVER TX/NRN MEXICO PROGRESSES EWD. EVIDENCE OF INCREASING LARGE-SCALE ASCENT IS REVEALED BY WV AND RADAR IMAGERY ACROSS CENTRAL AND NRN TX ATTM...AS INCREASING LOW-LEVEL WARM ADVECTION ASSOCIATED WITH THE AFOREMENTIONED STRENGTHENING OF THE LOW-LEVEL FLOW CONTINUES BENEATH MID-LEVEL CVA. AS THIS ZONE OF FAVORABLE QG FORCING SPREADS EWD...EXPECT PRECIPITATION ONGOING ACROSS CENTRAL AND NERN LA TO INCREASE OVER THE NEXT SEVERAL HOURS. WHILE MOST PRECIPITATION EXPANDING ATTM FARTHER W ACROSS NRN TX SHOULD REMAIN IN THE FORM OF SNOW GIVEN COOLER AIR ALOFT...CONTINUED WARM ADVECTION ATOP A SUB-FREEZING LOWER TROPOSPHERE E OF THE SABINE RIVER WILL ALLOW PRECIPITATION TO REMAIN LIQUID -- FALLING AS FREEZING RAIN. AREAS OF NWRN LA -- NW OF A LINE FROM ROUGHLY LFK /LUFKIN TX/ TO ELD /EL DORADO AR/ -- MAY EXPERIENCE PRIMARILY SNOW...AS THE LOWER TROPOSPHERE IS LIKELY TO REMAIN BELOW FREEZING ACROSS THIS PORTION OF THE AREA DESPITE WARM ADVECTION. HOWEVER...LOCATIONS FARTHER SE ACROSS MUCH OF LA AND INTO SWRN AND WRN MS WILL LIKELY BE AFFECTED BY SEVERAL HOURS OF FREEZING RAIN -- WHICH MAY LAST INTO EARLY MORNING RUSH HOUR IN SOME AREAS. ..GOSS.. 02/04/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAN...LIX...LCH...SHV... LAT...LON 29989285 29999363 30629380 31889320 33189166 33308978 32788944 31449048 30229200 29989285 Read more