Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 03/17/08

AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
929 AM CDT SAT MAR 15 2008 .UPDATE... THE COLD FRONT WAS STEADILY PUSHING ITS WAY THROUGH SE TX THIS MORNING. EXPECT THE FRONT OFF THE COAST BY THE EARLY AFTERNOON. DRIER CONDITIONS WITH NORTHWEST WINDS WILL FOLLOW THE FRONT. MADE A FEW TWEAKS TO THE FORECAST PRODUCTS TO FOLLOW MORE CLOSELY CONDITIONS BEHIND THE FRONT. 40 && .PREV DISCUSSION... /ISSUED 638 AM CDT SAT MAR 15 2008/ AVIATION (12Z TAF)... OF PARTICULAR NOTICE THIS MORNING IS THE GRAVITY WAVE PUSHING THROUGH SE TX AND HAS REACHED THE COAST. MOST TAF SITES WILL SEE A PRESSURE RISE WITH WINDS SHIFTING TO THE NW FOR A BRIEF TIME. CEILINGS MAY ALSO LIFT A BIT FROM THE LOW STRATUS AS WELL. COASTAL TAFS FOR LBX AND GLS REFLECT THIS THINKING. OTHERWISE...SW WINDS WILL CONTINUE AHEAD OF A COLD FRONT EXPECTED TO PUSH THROUGH THE AREA LATER THIS MORNING. WINDS SHOULD BE FROM THE NORTH DURING THE AFTERNOON AND VEER TO THE NE OVERNIGHT. WINDS MAY ALSO INCREASE A BIT FROM THE NORTHEAST AS RETURN FLOW SETS UP QUICKLY. VFR CONDITIONS ARE EXPECTED ONCE PATCHY FOG AND STRATUS LIFT THIS MORNING. 39 PREV DISCUSSION... /ISSUED 519 AM CDT SAT MAR 15 2008/ DISCUSSION... VERY STRONG CAP IN PLACE WITH LATEST ACARS SOUNDING SHOWING INVERSION EVIDENT AT 975-950MB. SW FLOW JUST OFF THE SURFACE WITH ENOUGH MIXING GOING ON TO HAMPER FOG DEVELOPMENT AND INLAND STRATUS. DRYLINE NEAR A COT-AUS-CRS LINE AT 09Z AND SHOULD COME EAST THROUGHOUT THE MORNING LEADING TO WEST AND EVENTUALLY NORTHWEST WINDS THIS MORNING FOR THE AREA BY 18Z WITH THE COLD FRONT PUSHING THROUGH ON ITS HEELS. THE SWING TO WEST WINDS AND THE INVERSION SHOULD LEAD TO VERY QUICK RISE IN TEMPERATURES AND LOWER TO MID 80S LOOK TO BE GOOD BET INLAND. WILL FORECAST A RECORD HIGH AT GLS AS WINDS BRING THE MID 80 AIR SOUTH ACROSS WEST BAY (COOLING) AND OVER GLS ISLAND THIS AFTERNOON...FORECASTING 79 WHICH WOULD SURPASS THE VERY OLD RECORD OF 78 DEGREES SET IN 1887. HIGH PRESSURE QUICKLY TRAVERSES BY TO THE NORTH AND WINDS COME AROUND TO THE EAST SUNDAY AND INCREASE WITH COOLER TEMPS ON TAP. THE WEATHER TO GET MORE INTERESTING MONDAY AS UPPER TROUGH OVER AZ COMES EAST AND HEIGHTS FALL OVER TX WITH A VERY DEEP SOUTHEAST TO SOUTH FLOW THAT DEVELOPS TAPPING INTO MOISTURE OVER THE BAY OF CAMPHECHE AND THE YUCATAN REGION...ALOFT SW FLOW TAPS MOISTURE OVER THE PACIFIC. BREEZY CONDITIONS SHOULD PREVAIL MONDAY. AS THE ASSOCIATED SURFACE LOW MOVES EAST EXPECTING TO SEE STORMS DEVELOP NEAR THE DRYLINE WELL TO THE WEST OF THE REGION...BY MONDAY NIGHT LLJ ACROSS SETX WILL RUN 50-65 KNOTS AND EXPECT TO SEE BREEZY CONDITIONS WITH WINDY CONDITIONS ON THE COAST. IF ANY THUNDERSTORMS DEVELOP IN THIS ENVIRONMENT EXPECT THEM TO GO SEVERE QUICKLY. TUESDAY...SEVERE WEATHER. THE MAIN ACTION SHOULD BE EARLY TUESDAY MORNING THROUGH THE EARLY EVENING HOURS. ON TUESDAY 130 KNOT SSW UPPER JET WILL CONTINUE TO DRAG IN LL MOISTURE WITH NEAR RECORD SETTING PW CURRENTLY BEING FORECAST BY BOTH GFS/NAM AT 1.95" FOR MARCH. THE BIG ISSUE WILL BE THE SEVERE WEATHER THREAT AS THE EXTREME LL WINDS THAT VEER WITH HEIGHT YIELD UP HELICITY VALUES 500-700M2/S2!!! INSTABILITY WILL BE PRESENT WITH CAPE RUNNING 500 TO 1800 J/KG AND NO CAP. THIS LOOKS LIKE AN OUTBREAK AND HAVE ALREADY BEGUN THE MENTION OF SEVERE TUESDAY 06Z THROUGH TUESDAY EVENING. I DONT THINK I AM GOING OUT ON LIMB TO SAY THIS MAY BE SIGNIFICANT TORNADO OUTBREAK FOR TX...SETX...AND POINTS EAST. WILL TRY TO DO A SPECIAL WEBCAST BRIEFING LATER THIS MORNING THAT WILL RUN ON THE HGX WEB FRONT PAGE. THIS SYSTEM SHOULD BLOW THROUGH BY 06Z WEDNESDAY AND DRY SEASONAL TEMPERATURES TO FOLLOW. 45 MARINE... SCA HAS BEEN HOISTED FOR UPPER TX COASTAL WATERS OUT 20NM TO 60NM AS WINDS AT THE 19 BUOY REMAIN A STEADY 22KTS WITH SEAS INCREASING. EXPECT THESE CONDITIONS TO LAST THROUGH ABOUT 12Z AND WINDS SHOULD DIMINISH AFTER THAT. SEAS MAY TAKE A LITTLE LONGER TO RESPOND BUT THINK BY 15Z CONDITIONS WILL BE BELOW EVEN SCEC CONDITIONS. THE SCEC REMAINS FOR THE BAYS AND WATERS OUT 20NM. WEAK FRONT SHOULD PUSH OFF THE COAST AFTER 18Z. RETURN FLOW SETS UP AGAIN ON SUNDAY WITH E TO SE WINDS. WINDS REALLY INCREASE SUN NIGHT INTO MON AND SCA CONDITIONS ARE EXPECTED TO DEVELOP. STRONG SE WINDS WILL PERSIST ALL THE WAY INTO TUE WHICH WILL LIKELY BUILD SEAS CLOSE TO 12-14FT IN OFFSHORE AREAS GIVEN AN UNLIMITED FETCH. SCA ADVISORY WILL LIKELY CONTINUE INTO WEDNESDAY WITH THE COLD FRONT PUSHING OFF THE COAST. CONDITIONS SHOULD SLOWLY IMPROVE INTO THE END OF THE WEEK. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 84 52 72 64 76 / 0 0 0 20 30 HOUSTON (IAH) 85 55 72 63 78 / 0 0 0 20 30 GALVESTON (GLS) 79 62 69 66 72 / 0 0 10 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY... WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...40 AVIATION/MARINE...47
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
638 AM CDT SAT MAR 15 2008 .AVIATION (12Z TAF)... OF PARTICULAR NOTICE THIS MORNING IS THE GRAVITY WAVE PUSHING THROUGH SE TX AND HAS REACHED THE COAST. MOST TAF SITES WILL SEE A PRESSURE RISE WITH WINDS SHIFTING TO THE NW FOR A BRIEF TIME. CEILINGS MAY ALSO LIFT A BIT FROM THE LOW STRATUS AS WELL. COASTAL TAFS FOR LBX AND GLS REFLECT THIS THINKING. OTHERWISE...SW WINDS WILL CONTINUE AHEAD OF A COLD FRONT EXPECTED TO PUSH THROUGH THE AREA LATER THIS MORNING. WINDS SHOULD BE FROM THE NORTH DURING THE AFTERNOON AND VEER TO THE NE OVERNIGHT. WINDS MAY ALSO INCREASE A BIT FROM THE NORTHEAST AS RETURN FLOW SETS UP QUICKLY. VFR CONDITIONS ARE EXPECTED ONCE PATCHY FOG AND STRATUS LIFT THIS MORNING. 39 && .PREV DISCUSSION... /ISSUED 519 AM CDT SAT MAR 15 2008/ DISCUSSION... VERY STRONG CAP IN PLACE WITH LATEST ACARS SOUNDING SHOWING INVERSION EVIDENT AT 975-950MB. SW FLOW JUST OFF THE SURFACE WITH ENOUGH MIXING GOING ON TO HAMPER FOG DEVELOPMENT AND INLAND STRATUS. DRYLINE NEAR A COT-AUS-CRS LINE AT 09Z AND SHOULD COME EAST THROUGHOUT THE MORNING LEADING TO WEST AND EVENTUALLY NORTHWEST WINDS THIS MORNING FOR THE AREA BY 18Z WITH THE COLD FRONT PUSHING THROUGH ON ITS HEELS. THE SWING TO WEST WINDS AND THE INVERSION SHOULD LEAD TO VERY QUICK RISE IN TEMPERATURES AND LOWER TO MID 80S LOOK TO BE GOOD BET INLAND. WILL FORECAST A RECORD HIGH AT GLS AS WINDS BRING THE MID 80 AIR SOUTH ACROSS WEST BAY (COOLING) AND OVER GLS ISLAND THIS AFTERNOON...FORECASTING 79 WHICH WOULD SURPASS THE VERY OLD RECORD OF 78 DEGREES SET IN 1887. HIGH PRESSURE QUICKLY TRAVERSES BY TO THE NORTH AND WINDS COME AROUND TO THE EAST SUNDAY AND INCREASE WITH COOLER TEMPS ON TAP. THE WEATHER TO GET MORE INTERESTING MONDAY AS UPPER TROUGH OVER AZ COMES EAST AND HEIGHTS FALL OVER TX WITH A VERY DEEP SOUTHEAST TO SOUTH FLOW THAT DEVELOPS TAPPING INTO MOISTURE OVER THE BAY OF CAMPHECHE AND THE YUCATAN REGION...ALOFT SW FLOW TAPS MOISTURE OVER THE PACIFIC. BREEZY CONDITIONS SHOULD PREVAIL MONDAY. AS THE ASSOCIATED SURFACE LOW MOVES EAST EXPECTING TO SEE STORMS DEVELOP NEAR THE DRYLINE WELL TO THE WEST OF THE REGION...BY MONDAY NIGHT LLJ ACROSS SETX WILL RUN 50-65 KNOTS AND EXPECT TO SEE BREEZY CONDITIONS WITH WINDY CONDITIONS ON THE COAST. IF ANY THUNDERSTORMS DEVELOP IN THIS ENVIRONMENT EXPECT THEM TO GO SEVERE QUICKLY. TUESDAY...SEVERE WEATHER. THE MAIN ACTION SHOULD BE EARLY TUESDAY MORNING THROUGH THE EARLY EVENING HOURS. ON TUESDAY 130 KNOT SSW UPPER JET WILL CONTINUE TO DRAG IN LL MOISTURE WITH NEAR RECORD SETTING PW CURRENTLY BEING FORECAST BY BOTH GFS/NAM AT 1.95" FOR MARCH. THE BIG ISSUE WILL BE THE SEVERE WEATHER THREAT AS THE EXTREME LL WINDS THAT VEER WITH HEIGHT YIELD UP HELICITY VALUES 500-700M2/S2!!! INSTABILITY WILL BE PRESENT WITH CAPE RUNNING 500 TO 1800 J/KG AND NO CAP. THIS LOOKS LIKE AN OUTBREAK AND HAVE ALREADY BEGUN THE MENTION OF SEVERE TUESDAY 06Z THROUGH TUESDAY EVENING. I DONT THINK I AM GOING OUT ON LIMB TO SAY THIS MAY BE SIGNIFICANT TORNADO OUTBREAK FOR TX...SETX...AND POINTS EAST. WILL TRY TO DO A SPECIAL WEBCAST BRIEFING LATER THIS MORNING THAT WILL RUN ON THE HGX WEB FRONT PAGE. THIS SYSTEM SHOULD BLOW THROUGH BY 06Z WEDNESDAY AND DRY SEASONAL TEMPERATURES TO FOLLOW. 45 AVIATION... LOW STRATUS AND SEA FOG ALONG THE COAST ARE SLOWLY LIFTING EARLY THIS MORNING. SUSPECT THERE IS SOME MIXING OF DRIER AIR FROM ALOFT HELPING TO BREAK UP THE CLOUD COVER OVER SE TX. ANY MVFR/IFR CONDITIONS WILL QUICKLY BREAK UP THROUGH THE MORNING HOURS. THE 88D VWP SHOW 50KTS AT 2KFT SO WILL APPROACH LLWS THRESHOLDS. DRYLINE/FRONT REMAINS NW OF THE AREA AND WILL PUSH THROUGH SE TX GRADUALLY THROUGHOUT THE DAY. WINDS WILL SLOWLY TURN TO THE N AFTER 18Z ACROSS THE REGION. VFR CONDITIONS ARE EXPECTED WITH THE DRIER AIRMASS MAKING ITS WAY SOUTH. OVERNIGHT...WINDS WILL VEER TO THE EAST WITH VFR CONDITIONS PREVAILING. 39 MARINE... SCA HAS BEEN HOISTED FOR UPPER TX COASTAL WATERS OUT 20NM TO 60NM AS WINDS AT THE 19 BUOY REMAIN A STEADY 22KTS WITH SEAS INCREASING. EXPECT THESE CONDITIONS TO LAST THROUGH ABOUT 12Z AND WINDS SHOULD DIMINISH AFTER THAT. SEAS MAY TAKE A LITTLE LONGER TO RESPOND BUT THINK BY 15Z CONDITIONS WILL BE BELOW EVEN SCEC CONDITIONS. THE SCEC REMAINS FOR THE BAYS AND WATERS OUT 20NM. WEAK FRONT SHOULD PUSH OFF THE COAST AFTER 18Z. RETURN FLOW SETS UP AGAIN ON SUNDAY WITH E TO SE WINDS. WINDS REALLY INCREASE SUN NIGHT INTO MON AND SCA CONDITIONS ARE EXPECTED TO DEVELOP. STRONG SE WINDS WILL PERSIST ALL THE WAY INTO TUE WHICH WILL LIKELY BUILD SEAS CLOSE TO 12-14FT IN OFFSHORE AREAS GIVEN AN UNLIMITED FETCH. SCA ADVISORY WILL LIKELY CONTINUE INTO WEDNESDAY WITH THE COLD FRONT PUSHING OFF THE COAST. CONDITIONS SHOULD SLOWLY IMPROVE INTO THE END OF THE WEEK. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 84 52 72 64 76 / 0 0 0 20 30 HOUSTON (IAH) 85 55 72 63 78 / 0 0 0 20 30 GALVESTON (GLS) 79 62 69 66 72 / 0 0 10 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY... WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...45 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
519 AM CDT SAT MAR 15 2008 .DISCUSSION... VERY STRONG CAP IN PLACE WITH LATEST ACARS SOUNDING SHOWING INVERSION EVIDENT AT 975-950MB. SW FLOW JUST OFF THE SURFACE WITH ENOUGH MIXING GOING ON TO HAMPER FOG DEVELOPMENT AND INLAND STRATUS. DRYLINE NEAR A COT-AUS-CRS LINE AT 09Z AND SHOULD COME EAST THROUGHOUT THE MORNING LEADING TO WEST AND EVENTUALLY NORTHWEST WINDS THIS MORNING FOR THE AREA BY 18Z WITH THE COLD FRONT PUSHING THROUGH ON ITS HEELS. THE SWING TO WEST WINDS AND THE INVERSION SHOULD LEAD TO VERY QUICK RISE IN TEMPERATURES AND LOWER TO MID 80S LOOK TO BE GOOD BET INLAND. WILL FORECAST A RECORD HIGH AT GLS AS WINDS BRING THE MID 80 AIR SOUTH ACROSS WEST BAY (COOLING) AND OVER GLS ISLAND THIS AFTERNOON...FORECASTING 79 WHICH WOULD SURPASS THE VERY OLD RECORD OF 78 DEGREES SET IN 1887. HIGH PRESSURE QUICKLY TRAVERSES BY TO THE NORTH AND WINDS COME AROUND TO THE EAST SUNDAY AND INCREASE WITH COOLER TEMPS ON TAP. THE WEATHER TO GET MORE INTERESTING MONDAY AS UPPER TROUGH OVER AZ COMES EAST AND HEIGHTS FALL OVER TX WITH A VERY DEEP SOUTHEAST TO SOUTH FLOW THAT DEVELOPS TAPPING INTO MOISTURE OVER THE BAY OF CAMPHECHE AND THE YUCATAN REGION...ALOFT SW FLOW TAPS MOISTURE OVER THE PACIFIC. BREEZY CONDITIONS SHOULD PREVAIL MONDAY. AS THE ASSOCIATED SURFACE LOW MOVES EAST EXPECTING TO SEE STORMS DEVELOP NEAR THE DRYLINE WELL TO THE WEST OF THE REGION...BY MONDAY NIGHT LLJ ACROSS SETX WILL RUN 50-65 KNOTS AND EXPECT TO SEE BREEZY CONDITIONS WITH WINDY CONDITIONS ON THE COAST. IF ANY THUNDERSTORMS DEVELOP IN THIS ENVIRONMENT EXPECT THEM TO GO SEVERE QUICKLY. TUESDAY...SEVERE WEATHER. THE MAIN ACTION SHOULD BE EARLY TUESDAY MORNING THROUGH THE EARLY EVENING HOURS. ON TUESDAY 130 KNOT SSW UPPER JET WILL CONTINUE TO DRAG IN LL MOISTURE WITH NEAR RECORD SETTING PW CURRENTLY BEING FORECAST BY BOTH GFS/NAM AT 1.95" FOR MARCH. THE BIG ISSUE WILL BE THE SEVERE WEATHER THREAT AS THE EXTREME LL WINDS THAT VEER WITH HEIGHT YIELD UP HELICITY VALUES 500-700M2/S2!!! INSTABILITY WILL BE PRESENT WITH CAPE RUNNING 500 TO 1800 J/KG AND NO CAP. THIS LOOKS LIKE AN OUTBREAK AND HAVE ALREADY BEGUN THE MENTION OF SEVERE TUESDAY 06Z THROUGH TUESDAY EVENING. I DONT THINK I AM GOING OUT ON LIMB TO SAY THIS MAY BE SIGNIFICANT TORNADO OUTBREAK FOR TX...SETX...AND POINTS EAST. WILL TRY TO DO A SPECIAL WEBCAST BRIEFING LATER THIS MORNING THAT WILL RUN ON THE HGX WEB FRONT PAGE. THIS SYSTEM SHOULD BLOW THROUGH BY 06Z WEDNESDAY AND DRY SEASONAL TEMPERATURES TO FOLLOW. 45 && .AVIATION... LOW STRATUS AND SEA FOG ALONG THE COAST ARE SLOWLY LIFTING EARLY THIS MORNING. SUSPECT THERE IS SOME MIXING OF DRIER AIR FROM ALOFT HELPING TO BREAK UP THE CLOUD COVER OVER SE TX. ANY MVFR/IFR CONDITIONS WILL QUICKLY BREAK UP THROUGH THE MORNING HOURS. THE 88D VWP SHOW 50KTS AT 2KFT SO WILL APPROACH LLWS THRESHOLDS. DRYLINE/FRONT REMAINS NW OF THE AREA AND WILL PUSH THROUGH SE TX GRADUALLY THROUGHOUT THE DAY. WINDS WILL SLOWLY TURN TO THE N AFTER 18Z ACROSS THE REGION. VFR CONDITIONS ARE EXPECTED WITH THE DRIER AIRMASS MAKING ITS WAY SOUTH. OVERNIGHT...WINDS WILL VEER TO THE EAST WITH VFR CONDITIONS PREVAILING. 39 && .MARINE... SCA HAS BEEN HOISTED FOR UPPER TX COASTAL WATERS OUT 20NM TO 60NM AS WINDS AT THE 19 BUOY REMAIN A STEADY 22KTS WITH SEAS INCREASING. EXPECT THESE CONDITIONS TO LAST THROUGH ABOUT 12Z AND WINDS SHOULD DIMINISH AFTER THAT. SEAS MAY TAKE A LITTLE LONGER TO RESPOND BUT THINK BY 15Z CONDITIONS WILL BE BELOW EVEN SCEC CONDITIONS. THE SCEC REMAINS FOR THE BAYS AND WATERS OUT 20NM. WEAK FRONT SHOULD PUSH OFF THE COAST AFTER 18Z. RETURN FLOW SETS UP AGAIN ON SUNDAY WITH E TO SE WINDS. WINDS REALLY INCREASE SUN NIGHT INTO MON AND SCA CONDITIONS ARE EXPECTED TO DEVELOP. STRONG SE WINDS WILL PERSIST ALL THE WAY INTO TUE WHICH WILL LIKELY BUILD SEAS CLOSE TO 12-14FT IN OFFSHORE AREAS GIVEN AN UNLIMITED FETCH. SCA ADVISORY WILL LIKELY CONTINUE INTO WEDNESDAY WITH THE COLD FRONT PUSHING OFF THE COAST. CONDITIONS SHOULD SLOWLY IMPROVE INTO THE END OF THE WEEK. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 84 52 72 64 76 / 0 0 0 20 30 HOUSTON (IAH) 85 55 72 63 78 / 0 0 0 20 30 GALVESTON (GLS) 79 62 69 66 72 / 0 0 10 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY... WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY UNTIL 11 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...45
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
951 AM CDT MON MAR 17 2008 .DISCUSSION... 949 AM CDT HAVE MADE SOME ADJUSTMENTS TO FIRST PERIOD TO INCREASE POPS THIS AFTERNOON. SWATH OF SHOWERS AND THUNDERSTORMS CURRENTLY STRETCHING FROM SOUTHERN ILLINOIS WESTWARD ACROSS NORTHERN/CENTRAL MISSOURI AND WEST INTO THE CENTRAL PLAINS CONTINUES TO LIFT NORTHEASTWARD TOWARD THE CWA. MORNING SOUNDING FROM KSGF INDICATES OVER 500 J/KG OF MUCAPE WHICH IN CONJUNCTION WITH THE VERY STRONG THETA E ADVECTION BEING DRIVEN BY THE RIDICULOUSLY STRONG 70KT 850MB LLJ HAS BEEN SUPPORTING THIS PRECIPITATION AND THUNDERSTORM ACTIVITY. UNFORTUNATELY NO SOUNDING AVAILABLE FROM KDVN THIS MORNING...AND KILX SOUNDING WAS MISSING CRITICAL RH DATA FROM 900-750MB...SO WORKING WITH ONE HAND TIED BEHIND OUR BACK THIS MORNING. THERMAL PROFILE FROM ILX DID INDICATE FAIRLY WEAK LAPSE RATES WHICH SUPPORTS MODEL GUIDANCE ASSERTION THAT INSTABILITY WILL BE VIRTUALLY NIL THIS AFTERNOON THIS FAR NORTH. DESPITE THIS...GIVEN THE ONGOING CONVECTION AND EXTREMELY STRONG THETA E ADVECTION DID FEEL IT WAS PRUDENT TO INTRODUCE THUNDER INTO THE GRIDS THIS AFTERNOON OVER SOUTHERN PORTIONS OF THE CWA. OTHER QUESTION THIS AFTERNOON IS THE PRECIP TYPE. WHILE WHAT WE CAN SEE OF THE ILX SOUNDING IS FAIRLY SATURATED...A COUPLE OF WELL PLACED ACARS/TAMDAR SOUNDINGS FROM BMI AND MLI WITH MOISTURE PROFILES REVEALED A LAYER OF VERY DRY AIR FROM 900-750MB. THIS CONFIRMS WHAT THE MODELS HAVE SHOWN WITH WET BULB TEMPS <0C ABOVE ABOUT 2500FT AGL...SO AS RAIN FALLS INTO THIS SUB-SATURATED AIRMASS EVAPORATIVE COOLING WILL AT LEAST PARTIALLY OFFSET WARM AIR ADVECTION INITIALLY WITH THE POTENTIAL FOR PRECIP TO START AS SLEET OR SNOW. QUICK LOOK AT 09Z SREF AND 12Z WRF-NMM STILL SUPPORTS THE FLOOD WATCH WITH THE POTENTIAL FOR ONE TO THREE INCHES OF RAIN ACROSS THE FLOOD WATCH. ACROSS THE REMAINDER OF THE CWA RAINFALL AMOUNTS OF A HALF AN INCH TO AN INCH LOOK PLAUSIBLE WHICH WILL BE ENOUGH TO LEAD TO RE-NEWED RISES ON RIVERS AND MAINLY SOME MINOR NUISANCE TYPE FLOODING/HIGH WATER. UPDATED GRIDS/DERIVED PRODUCTS HAVE BEEN SHIPPED. UPDATED FFA TO FOLLOW SHORTLY. IZZI && .PREV DISCUSSION... 321 AM CDT A STRONG CIRCULATION IS SEEN ON THE 850 MB PROFILER DATA OVER NEW MEXICO AT 07 UTC. THE WIND HAS INCREASED TO 60 TO 65 KNOTS OVER OKLAHOMA. THIS WAVE IN THE SOUTHERN ROCKIES AND SOUTHERN PLAINS HAS A LOT OF KINETIC ENERGY WITH IT. A 130 KNOT 300 MB JET STREAM IS SEEN MOVING INTO SOUTHERN NEW MEXICO AT 00 UTC. THE 500 MB WAVE TROUGH MOVES INTO MISSISSIPPI VALLEY BY 12 UTC WEDNESDAY. WE USED THE ECMWF AND THE GFS MODELS. THE GFS MODEL BRINGS A DOUBLE LOW INTO THE OHIO VALLEY BY 12 UTC WEDNESDAY. ONE LOW IS FORECAST IN OHIO AND THE OTHER NEAR BOWLING GREEN KENTUCKY. A BAND OF HEAVY RAIN IS FORECAST ACROSS CENTRAL ILLINOIS AND NORTH CENTRAL INDIANA TONIGHT. THIS IS DUE TO THE WARM AIR OVERRUNNING COLD AIR IN NORTHERN ILLINOIS AND NORTHWEST INDIANA THIS EVENING THROUGH TUESDAY. THE OMEGA FORECAST FROM THE LOCAL WRF MODEL...GFS AND NAM SHOW A LOT OF LIFT WITH THIS STORM. HENCE THE MODELS SHOW LARGE VALUES OF PRECIPITATION OVER OUR SOUTHERN COUNTIES. WE SILL ISSUE A FLOOD WATCH FROM 00 UTC TUESDAY TO 12 UTC WEDNESDAY FOR OUR SOUTHERN COUNTIES. THE FORECAST SOUNDINGS SHOW THAT THE PRECIPITATION WILL BE RAIN. THE SNOW AND RAIN MIXTURE WILL NOT MOVE INTO OUR CWA UNTIL LATE TUESDAY NIGHT AND EARLY WEDNESDAY. && .AVIATION... 659 AM CDT RE 12Z TAFORS...MULTIPLE IMPULSES MOVING THRU STRONG BROAD SW FLO ACROSS NORTHERN MEX AND TX TO THE UPPER MIDWEST. RADAR COMPOSITE SHOWS BAND OF ECHOES LIFTING NORTHEASTWARD ACROSS SOUTHERN WI...NORTHEAST IL AND NORTHERN IN EARLY THIS MORNING BUT NOTHING OBSERVED AT THE SURFACE AS PRECIP FALLING INTO A SIGNIFICANTLY DEEP LAYER OF DRY AIR. SN FALLING FURTHER W ACROSS NORTHERN IA INTO SOUTHERN MN AHEAD OF A SHORT WAVE TROF LIFTING FM NEB AND SOUTHERN IA AND WHERE DEEP LAYER ADVECTION OF MOISTURE HAS BEEN OCCURRING. SATELLITE SHOWS NEXT SHORT WAVE LIFTING FROM THE TX PANHANDLE INTO S CENTRAL KS. STRONG THETA-E ADVECTION TO SPREAD ACROSS THE MID MS VALLEY AHEAD OF THE SHORT WAVE LATER TODAY. LOWER LEVELS WILL STILL NEED TO BE OVERCOME BEFORE PRECIP BREAKS OUT AND NAM MODEL SOUNDINGS SUGGEST EVAPORATIVE COOLING AT ONSET OF NEXT ROUND OF PRECIP LATE THIS AFTERNOON MAY BE ENOUGH FOR A BRIEF PERIOD OF PL OR SN BEFORE STRONG WAA OVERWHELMS. MODELS IN DECENT AGREEMENT IN BRINGING A PERIOD OF MODERATE TO HEAVY RA TO THE AREA THIS EVENING WITH STRONG H8 CONVERGENCE AS WELL AS STRONG ISENTROPIC LIFT. THIS PROGGED TO SHIFT ENE OF TERMINALS LATER TONIGHT BUT WILL STILL BE -RA AND DZ AROUND THRU THE END OF THE PD. MODELS KEEP SFC BOUNDARY S OF TERMINALS THRU 12Z SO EXPECT WIDESPREAD IFR/LIFR CIGS ACROSS NORTHERN IL. TRS && .MARINE... 333 AM CDT STRONG RIDGE OF HI PRES FROM QUEBEC S ACROSS THE CAROLINAS MOVES VERY SLOWLY E THRU TONIGHT WHILE LEAD LOW PRES MOVES NE ACROSS THE MID MS VALLEY. INCREASING PRES GRADIENT OVER THE WESTERN GREAT LAKES AS THE DISTANCE BETWEEN THE CENTERS OF THE HI AND LO DECREASES BUT LOW LEVEL TEMPERATURE PROFILE OVER LAKE MI INDICATING THAT SURFACE WINDS WILL BE SOMEWHAT DECOUPLED FROM THE STRONGER WINDS DUE TO LAMINAR FLO. MAIN LO PRES LIFTS ACROSS THE OH VALLEY TUE NIGHT AND FORECAST TO DEEPEN SIGNIFICANTLY AS TO REACHES THE EASTERN GREAT LAKES LATE WED. STRONG LO LEVEL COLD AIR ADVECTION OCCURRING OVER THE WESTERN LAKES AS THE MID LEVEL TROF IS MOVING E OVER THE CENTRAL BY THEN. WITH DEEPENING LOW MOVING UP THE ST. LAWRENCE VALLEY AND A RIDGE OF HI PRES BUILDING INTO WESTERN ONTARIO AND THE UPPER MIDWEST POTENTIAL FOR A PERIOD OF LOWER END GALES WED AFTERNOON INTO WED NIGHT BUT HAVE CAPPED FORECAST SUSTAINED WINDS AT 30 KTS FOR NOW DUE TO FORECAST UNCERTAINTY ON STRENGTH OF WINDS OVER LAKE MI AT THAT TIME. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH WEDNESDAY MORNING FOR ILZ023-032-033-039. IN...FLOOD WATCH FROM 7 PM CDT /8 PM EDT/ THIS EVENING THROUGH WEDNESDAY MORNING FOR INZ010-011-019. LM...NONE. && $$