Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/19/15


AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
933 AM PDT Fri Apr 17 2015 .Synopsis... Warm weekend then cooling trend into mid week. A weak weather system will bring a slight chance of mountain showers and thunderstorms this weekend into Monday. A cold upper level trough moves into the area by mid week bringing cooler temperatures and a chance of precipitation over all of interior Northern California. && .Discussion... Cooler morning in the Valley with light winds and mountains warmer with a warmer air mass. Temperatures this afternoon will rise into the mid 80s in the Valley and low 50s to low 70s in the mountains which is about 10 to 15 degrees above normal for mid April. Temperatures warm up a little more on Saturday with high in the mid 80s to around 90 in the Valley and mid 50s to mid 70s in the mountains. Similar temperatures are expected on Sunday then a little cooler temperatures on Monday as trough approaches the area and onshore flow increases. Air temperatures are warm but water temperatures in rivers and lakes remains cold in the low 40s to low 60s. People going in the rivers and lakes this weekend should use caution since cold water can lead to hypothermia. A weak disturbance moves into Northern California on Saturday then forms a weak upper level low off the Nor Cal coast late Saturday into Sunday. This will bring some instability for a slight chance of showers and thunderstorms over the mountains of interior Northern California on Saturday and Sunday, mainly in the afternoons and evenings. The best chance on Sunday looks like it will be over the Sierra as the disturbance moves southwest. Upper level trough trough digs offshore of the West Coast on Monday for continued instability over the mountains for a slight chance of showers and thunderstorms. .Extended Discussion (Tuesday through Friday) Mid range models zeroing in on idea of bringing weak Pacific trough onto the coast around Tuesday although ECMWF and GEM still have trough axis slightly offshore Tuesday afternoon. Rather limited moisture with this system will limit precipitation mainly to the mountain areas. GFS shows enough instability with this system Tuesday afternoon to warrant slight thunderstorm threat as well. Models all now pretty much centering the upper trough over the west coast by Wednesday morning so entire CWA has at least a slight threat of showers throughout the day Wednesday. GFS shows most of the instability has moved into Nevada by Wednesday but still somewhat borderline over central California so may need to readdress thunderstorm threat for Wednesday as we get closer. Weather change that appears fairly certain is the significant cool off expected Tuesday and Wednesday. Forecast highs between Monday and Wednesday showing a drop of anywhere from 15 to 20 degrees so this change will be quite noticeable with highs dropping to around normal for this time of year by mid week. Models vary a bit on positioning of low/trough on Thursday but whichever solution verifies...cyclonic flow over the region should continue the shower threat CWA wide. Extended models showing a transition to northerly flow aloft over the north state by Friday as upper system shifts into the Great Basin. As a result...shower threat shifts eastward with main precipitation threat from RAP around moisture over the Sierra. Daytime temperatures rebound a bit but still close to normal compared to very warm temperatures expected early in the week. && .Aviation... VFR conditions next 24 hours. Isolated thunderstorms possible over the mountains after 18z Saturday. Winds generally below 15 knots except in vicinity of thunderstorms. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
241 AM PDT Fri Apr 17 2015 .Synopsis... Very warm temperatures through the weekend. A weak weather system will bring a slight chance of mountain showers or an isolated thundertorm this weekend. Temperatures then start cooling Monday through Wednesday with a chance of rain most areas. && .Discussion... Very little change to previous forecast. Very warm conditions will continue today through Sunday. A weak upper disturbance will move into the area this weekend. It will bring some instability with it for just a slight chance of mainly afternoon and evening showers or a thunderstorm both Saturday and Sunday. Troughing still forecast to start carving out over the area on Monday which will allow temperatures to begin cooling. Moisture chances Monday look to remain only in the higher terrain. Rasch .Extended Discussion (Tuesday through Friday) Mid range models zeroing in on idea of bringing weak Pacific trough onto the coast around Tuesday although ECMWF and GEM still have trough axis slightly offshore Tuesday afternoon. Rather limited moisture with this system will limit precipitation mainly to the mountain areas. GFS shows enough instability with this system Tuesday afternoon to warrant slight thunderstorm threat as well. Models all now pretty much centering the upper trough over the west coast by Wednesday morning so entire CWA has at least a slight threat of showers throughout the day Wednesday. GFS shows most of the instability has moved into Nevada by Wednesday but still somewhat borderline over central California so may need to readdress thunderstorm threat for Wednesday as we get closer. Weather change that appears fairly certain is the significant cool off expected Tuesday and Wednesday. Forecast highs between Monday and Wednesday showing a drop of anywhere from 15 to 20 degrees so this change will be quite noticeable with highs dropping to around normal for this time of year by mid week. Models vary a bit on positioning of low/trough on Thursday but whichever solution verifies...cyclonic flow over the region should continue the shower threat CWA wide. Extended models showing a transition to northerly flow aloft over the north state by Friday as upper system shifts into the Great Basin. As a result...shower threat shifts eastward with main precipitation threat from RAP around moisture over the Sierra. Daytime temperatures rebound a bit but still close to normal compared to very warm temperatures expected early in the week. && .Aviation... VFR conditions next 24 hours. Isolated thunderstorms possible over the mountains after 18z Saturday. Winds generally below 15 knots except in vicinity of thunderstorms. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
749 PM MDT SAT APR 18 2015 .UPDATE... ISSUED AT 750 PM MDT SAT APR 18 2015 UPPER LEVEL LOW NOW OVER FAR EASTERN COLORADO AND WILL MOVE INTO WESTERN KANSAS OVERNIGHT. THE SHOWERS AND THUNDERSTORMS HAVE DECREASED THIS EVENING AS THE AIRMASS HAS STABILIZED SOME. STILL EXPECT SHOWERS TO INCREASE OVERNIGHT ON THE BACKSIDE OF THE LOW. WILL CONTINUE WITH HIGH POPS THIS EVENING AND OVERNIGHT. FOR THE MOUNTAINS...FAVORED AREAS WILL SEE 3 TO 6 INCHES WITH LESS ELSEWHERE. FOR THE FRONT RANGE AND EASTERN PLAINS...SNOW LEVEL WILL START OFF ABOVE 6000 FEET...BUT LOWER OVERNIGHT AS THE AIRMASS COOLS. COULD SEE AN INCH OR TWO OF SLUSHY ACCUMULATION ALONG THE PALMER DIVIDE AND NEAR THE FOOTHILLS BY DAY BREAK. WINDS WILL INCREASE TONIGHT AS THE LOW MOVES OFF. MAY SEE GUSTS OF 40 TO 50 MPH OVER THE PLAINS LATE TONIGHT AND EARLY SUNDAY. WILL INCREASE WINDS IN THE FORECAST A LITTLE MORE. ON SUNDAY...EXPECT DRIER AIR TO MOVE OVER THE PLAINS AND BRING THE SHOWERS TO AN END DURING THE MORNING. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 322 PM MDT SAT APR 18 2015 UPPER LEVEL LOW HAS MADE VERY LITTLE EASTWARD PROGRESS TODAY AND IS STILL LOCATED OVER SOUTHWEST WASHINGTON COUNTY...BASED ON THE RECENT MOTION OF RADAR ECHOES. AFTERNOON HEATING AND COLD TEMPERATURES ALOFT HAVE DE-STABILIZED THE AIRMASS ENOUGH FOR EMBEDDED THUNDERSTORMS TO DEVELOP OVER THE FAR NORTHEAST PLAINS. MOUNTAIN AREAS HAVE BEEN PICKING UP SCATTERED SNOW SHOWERS...BUT NOT MUCH NEW SNOW ACCUMULATION...BASED ON WEB CAMERAS AND SNOTEL DATA. THE SHOWERS AND THUNDERSTORMS THIS EVENING SHOULD TAPER IN THE EVENING...WITH THE LOSS OF DAYTIME HEATING. ADDITIONAL SHOWERS ARE EXPECTED OVERNIGHT AS THE UPPER LOW MOVES EASTWARD AND THE RETURN FLOW ON THE BACKSIDE OF THE LOW MOVES OUT OF THE MOUNTAINS AND ACROSS THE PLAINS. THE NAM AND RAP FORECASTS HAVE RAIN OCCURRING THROUGH MOST OF THE NIGHT AND THEN A DECREASE IN SHOWER ACTIVITY BY MIDDAY SUNDAY. TEMPERATURES OVERNIGHT WILL DROP TO THE MID AND UPPER 30S ON THE PLAINS WHICH MAY BE COOL ENOUGH FOR SOME SNOW TO FALL. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED THOUGH. SUNDAY WILL BE A MIX OF MORNING SHOWERS AND THEN DECREASING CLOUDS IN THE AFTERNOON. STRONG INSOLATION SHOULD ALLOW AFTERNOON TEMPERATURES TO CLIMB INTO THE LOWER 50S. MOUNTAIN AREAS COULD SEE SCATTERED SNOW SHOWERS CONTINUE AS WE REMAIN UNDER MOIST NORTHWESTERLY FLOW. SNOW ACCUMULATIONS SHOULD BE LESS THAN 3 OR 4 INCHES. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 322 PM MDT SAT APR 18 2015 A COLD NORTHWEST FLOW ON THE BACK SIDE OF EXITING LONG WAY UPPER TROUGH DRIVES A CLIPPER TYPE DISTURBANCE SOUTHWARD OUT OF WYOMING SUNDAY NIGHT AND MONDAY MORNING ACCORDING TO DETERMINISTIC MODELS. SYSTEM APPEARS TO PACK ADJACENT COLD AIR...MOISTURE AND OROGRAPHIC LIFT TO PRODUCE ANOTHER ROUND OF LIGHT SNOW ACCUMULATION IN THE HIGHER MTN RANGES. MTN PASSES AND EXPOSED NORTHWEST SLOPES COULD SEE ANYWHERE FROM 2-5 INCHES OF ADDITIONAL SNOW ACCUMULATION BY MONDAY EVENING. WETBULB TEMP IS PROGGED TO BE LOW ENOUGH FOR A RAIN/SNOW MIX ON THE NEAR BY PLAINS SUNDAY EVENING...AND POSSIBLY ALL SNOW LATE SUNDAY NIGHT INTO MONDAY MORNING. THIS SYSTEM DOES NOT LOOK LIKE A BIG PRECIP MAKER FOR THE PLAINS AND ANY SNOW THAT FALLS AT LOWER ELEVATIONS SHOULD NOT ACCUMULATE. MODELS SHOW THIS DISTURBANCE QUICKLY MOVING OUT OF THE FCST AREA DURING THE DAY MONDAY AND WITH LOW LEVEL WINDS TURNING WESTERLY... TEMPS SHOULD MANAGE TO REACH THE 50S ON THE PLAINS WITH SUNSHINE RETURNING LATE IN THE DAY. MODELS SHOW A BREAK IN THE COOL AND WET NWLY FLOW PATTERN TUESDAY INTO WEDNESDAY WHEN A DIRTY SHORTWAVE UPPER RIDGE OVER THE GREAT BASIN WORKS ITS WAY ACROSS COLORADO. GFS AND NAM INDICATE A FAIR AMOUNT OF MID AND HIGH LEVEL MOISTURE WITH THIS RIDGE...SUFFICIENT TO WARRANT A CHANCE OF RAIN/SNOW SHOWERS IN THE HIGH COUNTRY ON TUESDAY AND AGAIN BY WEDNESDAY AFTERNOON. LATE DAY SHOWERS ON WEDNESDAY COULD BE ACCOMPANIED BY SOME THUNDER DURING THE WARMEST TIME OF THE DAY. ON THE PLAINS...DRY CONDITIONS WILL PREVAIL WITH A PREVAILING W-SWLY LOW LEVEL FLOW. AS A RESULT...TEMPS REBOUND WITH AFTN READINGS 1-5 DEG F ABOVE AVERAGE ON TUES AND 5-10 DEG ABOVE AVERAGE BY WED. LATE ON WEDNESDAY UPPER RIDGE OVER COLORADO APPEARS TO FLATTEN OUT WITH MODELS SHOWING A WEAK SHORTWAVE TROUGH ZOOMING UP FROM THE DESERT SOUTHWEST AND THEN ROUNDING THE TOP OF RIDGE. SHOULD THIS HAPPEN...CAN SEE PRECIP CHANCES ON THE RISE AGAIN ACRS THE CWA WITH RAIN/SNOW IN THE HIGH COUNTRY AND RAIN SHOWERS ON THE PLAINS. THERE/S ALSO A SLIGHT CHANCE OF T-STORMS BY EVENING. THURSDAY AND BEYOND...LARGE SCALE FLOW PATTERN OVER THE WESTERN CONUS IS PROGGED TO BECOME MORE LIVELY WITH YET ANOTHER LARGE SCALE UPPER TROUGH MAKING ITSELF FELT IN THE GREAT BASIN WEDNESDAY INTO THURSDAY AND ACROSS THE NORTH CENTRAL AND NORTHEAST THURSDAY AND FRIDAY. WITH AS MUCH MOISTURE AND COOL AIR WITH THIS SYSTEM...WILL CONTINUE LOW POPS FOR ALL AREAS RIGHT THROUGH SATURDAY. && .AVIATION...(FOR THE TAFS THROUGH 06Z SUNDAY EVENING) ISSUED AT 750 PM MDT SAT APR 18 2015 SHOWERS AND THUNDERSTORMS HAVE DECREASED THIS EVENING AS THE AIRMASS HAS STABILIZED. ADDITIONAL RAIN AND SNOW SHOWERS ARE EXPECTED OVERNIGHT DUE TO LIFT FROM THE UPPER LEVEL LOW. LITTLE TO NO SNOW ACCUMULATION IS EXPECTED. THE BEST CHANCE FOR SNOW ACCUMULATION WILL BE AT KAPA. NORTHERLY WINDS WILL PREVAIL THROUGH SUNDAY AND BE GUSTY AT TIMES WITH GUSTS TO 30 KNOTS LATE TONIGHT AND SUNDAY. CEILINGS WILL FALL TO 1500 TO 3000 AS THE SHOWER ACTIVITY PUSHES THROUGH. CEILINGS WILL THEN SLOWLY RISE SUNDAY MORNING TO ABOVE 6000 FEET BY 20Z. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MEIER SHORT TERM...DANKERS LONG TERM...BAKER AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
744 PM MDT SAT APR 18 2015 .UPDATE... ISSUED AT 744 PM MDT SAT APR 18 2015 UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG AS WELL. && .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 325 PM MDT SAT APR 18 2015 THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING. CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT. BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE. TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO 10 DEGREES BELOW NORMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM MDT SAT APR 18 2015 UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY. TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT. GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 641 PM MDT SAT APR 18 2015 THE SLOW MOVING LOW PRESSURE SYSTEM WHICH HAS IMPACTED THE REGION FOR THE LATTER PART OF THE WEEK WILL CONTINUE TO BRING PRECIPITATION TO THE AREA TONIGHT. AIRPORTS WILL HAVE OCCASIONAL RAIN OR SNOW SHOWERS RESULTING MVFR CIGS/VSBY WITH LOCALIZED IFR CONDITIONS. MOUNTAINS WILL LARGELY BE OBSCURED IN CLOUDS AND SHOWERS. LATER TONIGHT SOME AREAS MAY EXPERIENCE FOG CAPABLE OF YIELDING IFR CONDITIONS. FOG WILL LINGER THROUGH 17Z THEN RAPIDLY DISSIPATE. VFR CONDITIONS RETURN TO THE AREA SUNDAY AFTERNOON AS THE STORM SHIFTS EAST. HOWEVER...MOUNTAIN SNOW SHOWERS WILL CONTINUE OVER THE DIVIDE MOUNTAINS AND THE EASTERN UINTAS THOUGH IMPACTS ON ADJACENT AIRPORTS IS UNLIKELY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010- 012-017-018. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003- 004-013. UT...NONE. && $$ UPDATE...15 SHORT TERM...TGR LONG TERM...JAD AVIATION...NL
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
641 PM MDT SAT APR 18 2015 .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 325 PM MDT SAT APR 18 2015 THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING. CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT. BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE. TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO 10 DEGREES BELOW NORMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM MDT SAT APR 18 2015 UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY. TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT. GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 641 PM MDT SAT APR 18 2015 THE SLOW MOVING LOW PRESSURE SYSTEM WHICH HAS IMPACTED THE REGION FOR THE LATTER PART OF THE WEEK WILL CONTINUE TO BRING PRECIPITATION TO THE AREA TONIGHT. AIRPORTS WILL HAVE OCCASIONAL RAIN OR SNOW SHOWERS RESULTING MVFR CIGS/VSBY WITH LOCALIZED IFR CONDITIONS. MOUNTAINS WILL LARGELY BE OBSCURED IN CLOUDS AND SHOWERS. LATER TONIGHT SOME AREAS MAY EXPERIENCE FOG CAPABLE OF YIELDING IFR CONDITIONS. FOG WILL LINGER THROUGH 17Z THEN RAPIDLY DISSIPATE. VFR CONDITIONS RETURN TO THE AREA SUNDAY AFTERNOON AS THE STORM SHIFTS EAST. HOWEVER...MOUNTAIN SNOW SHOWERS WILL CONTINUE OVER THE DIVIDE MOUNTAINS AND THE EASTERN UINTAS THOUGH IMPACTS ON ADJACENT AIRPORTS IS UNLIKELY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010- 012-017-018. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003- 004-013. UT...NONE. && $$ SHORT TERM...TGR LONG TERM...JAD AVIATION...NL
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1107 AM MDT FRI APR 17 2015 .UPDATE... ISSUED AT 1010 AM MDT FRI APR 17 2015 THE UPPER LOW OVER THE SW QUAD OF THE STATE IS CONTINUING TO SWEEP HEAVY SNOWFALL BACK INTO THE LAKE AND CHAFFEE COUNTY AREAS...AS PER LATEST SATELLITE IMAGERY AND SPOTTER REPORTS. THEREFORE...UPGRADED EXISTING SNOW ADVISORIES FOR LOWER PORTIONS OF LAKE AND CHAFFEE COUNTIES TO A WINTER STORM WARNING...IN EFFECT UNTIL 12Z TOMORROW MORNING. MOORE && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM MDT FRI APR 17 2015 THERE ARE SEVERAL CONCERNS FOR THE SHORT TERM FORECAST...INCLUDING THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS...THE POTENTIAL FOR SEVERE STORMS AND SNOW AMOUNTS. STILL SEE OCNL LIGHTNING STRIKES OVR SERN CO THIS MORNING. SATELLITE IMAGES SHOW THE UPR LOW CENTERED OVR NWRN NM THIS MORNING...AND IT IS FORECAST TO MOVE NORTHEASTWARD TODAY AND TONIGHT. BY 12Z SAT...THE NAM...GFS AND ECMWF SHOW THE LOW CENTER IN DIFFERENT LOCATIONS. THE GFS AND ECMWF ARE FAIRLY SIMILAR WITH THE LOW ABOUT OVR THE PALMER DVD...THE GFS IS A LITTLE FARTHER E AND S THAN THE ECMWF. THE NAM HAS THE LOW CENTER AT 12Z SAT OVR NRN SAGUACHE COUNTY. FOR THE FIRST HALF OF TODAY THE MODELS SHOW CONTINUED MOIST EASTERLY FLOW ACRS THE PIKES PEAK REGION...FREMONT COUNTY AND LAKE AND CHAFFEE COUNTIES...WITH SOME PCPN ALSO OVR THE SW MTNS AND SRN PORTIONS OF THE ERN MTNS...JUST NOT AS HEAVY AS NRN AREAS. AT THE SAME TIME...A DRY SLOT WL WORK ITS WAY INTO THE SERN PLAINS. HOWEVER...THE NAM HAS AN AREA OF CONVECTION DEVELOPING...MAINLY N OF HIGHWAY 50 OVR THE ERN PLAINS THIS AFTERNOON...WITH LAS ANIMAS AND BACA COUNTIES REMAINING DRY. THE GFS AND HRRR ARE DRY THIS AFTERNOON OVR THE FAR SERN PLAINS. STRONG SOUTHERLY WINDS OVR BACA AND LAS ANIMAS COUNTIES...ALONG WITH RH VALUES DROPPING BELOW 15 PERCENT ARE EXPECTED THIS AFTERNOON SO WL ISSUE A RED FLAG WARNING FOR THESE LOCATIONS. PORTIONS OF SRN PROWERS AND BENT COUNTIES MAY ALSO REACH RED FLAG CRITERIA...BUT UNCERTAINTY ABOUT PCPN OVR THESE COUNTIES WL KEEP ME FROM ISSUING A FIRE HIGHLIGHT AT THIS TIME. THE NAM DECREASES PCPN OVR MANY OF THE MTN AREAS THIS AFTERNOON...WHILE IT STILL LOOKS GOOD ON THE GFS OVR THE NRN MTNS PORTIONS OF THE CWA. THE ECMWF DECREASES PCPN OVR THE PIKES PEAK REGION BUT KEEPS GOOD PCPN GOING OVR LAKE AND CHAFFEE COUNTIES. THE GFS IS MUCH DRIER AT THE SFC THIS AFTERNOON OVR THE FAR SERN PLAINS THAN THE NAM...WHICH MAKES A DIFFERENCE IN THE POTENTIAL FOR SEVERE WX. WL LEAN THE FORECAST A LITTLE MORE TOWARD THE NAM OVR PROWERS...BENT...AND KIOWA COUNTIES. IF THE NAM IS CORRECT...CAPE VALUES COULD RANGE FROM ABOUT 600-1500 J/KG OVR PROWERS...NRN BENT AND KIOWA COUNTIES...WITH 0-6KM SHEAR VALUES OF 50-60 KTS...AND WE COULD SEE A COUPLE SEVERE STORMS. THE HRRR ALSO SETS UP A DRYLINE MAINLY NORTH OF HIGHWAY 50S THIS AFTERNOON OVR THE FAR SERN PLAINS. HOWEVER...IF THE DRIER GFS IS CORRECT THE BETTER MSTR AND SVR CHANCES WL BE EAST OF THE AREA. TONIGHT AS THE UPR LOW CONTINUES TO LIFT NORTHEASTWARD...MUCH OF THE SERN PLAINS LOOK TO BE DRY...WITH MANY OF THE MTN AREAS STILL SEEING SOME PCPN. ALTHOUGH THE DIFFERING POSITIONS OF THE UPR LOW CENTER RESULT IN DIFFERENCES IN WHAT MTNS AREAS WL HAVE THE BEST PCPN CHANCES. WILL NOT MAKE ANY CHANGES TO THE WINTER WEATHER HIGHLIGHTS THIS MORNING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 410 AM MDT FRI APR 17 2015 SATURDAY-SUNDAY...LATEST MODELS REMAIN IN DECENT AGREEMENT OF STRONG UPPER LOW ACROSS SOUTH CENTRAL COLORADO EARLY SATURDAY SLOWLY LIFTING NORTH AND EAST THROUGH SATURDAY NIGHT WITH THE SYSTEM THEN WEAKENING AND MERGING WITH A BROAD UPPER TROUGH TRANSLATING ACROSS THE NORTHERN TIER OF STATES. BEST CHANCES OF PRECIPITATION EARLY SATURDAY REMAINS ACROSS THE CONTDVD THROUGH THE SOUTHERN MTS WITH DEVELOPING WRAPAROUND PRECIPITATION SHIELD AND DEVELOPING NORTHWEST FLOW BEHIND THE PASSING SYSTEM. SHOULD SEE ISOLATED TO SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS THE EASTERN PLAINS SATURDAY AFTERNOON AND EVENING WITH COLD CORE UPPER LOW TRANSLATING INTO NORTHEASTERN COLORADO. MAY NEED TO EXTEND OR ADD WINTER HIGHLIGHTS ACROSS THE CENTRAL MTS INTO SATURDAY WITH SEVERAL INCHES OF SNOW EXPECTED...ESPECIALLY AOA 10KT FEET. MID LEVEL TEMPS SLOWLY WARM SATURDAY AS THE SYSTEM LIFTS OUT ACROSS THE AREA AND SHOULD SEE HIGHS SLIGHTLY WARMER AS A RESULT...THOUGH STILL BELOW SEASONAL AVERAGES. PASSING UPPER SYSTEM ACROSS THE AREA LATE SATURDAY SENDS A COLD FRONT ACROSS THE EASTERN PLAINS EARLY SUNDAY MORNING...WITH GUSTY NORTH TO NORTHWEST WINDS OF 20 TO 40 MPH EXPECTED IN ITS WAKE...WITH THE STRONGEST WINDS EXPECTED ACROSS THE FAR EASTERN PLAINS. A MINOR WAVE EMBEDDED WITHIN THE NORTHWEST FLOW ALOFT SUPPORTS ISOLATED TO SCATTERED SHOWERS ACROSS THE AREA ON SUNDAY...WITH TEMPERATURES SLIGHTLY COOLER THAN SATURDAY. MONDAY-TUESDAY...EMBEDDED DISTURBANCES IN THE SLOWLY MODERATING NORTHWEST FLOW ACROSS THE AREA WILL KEEP ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS IN THE FORECAST WITH TEMPERATURES WARMING BACK TO NEAR SEASONAL AVERAGES. WEDNESDAY-THURSDAY...A REX LIKE BLOCKING PATTERN LOOKS TO SET UP ACROSS THE REGION WITH RIDGING ACROSS THE ROCKIES AND TROUGHS SETTING UP OVER THE COASTS. THIS LOOKS TO KEEP UNSETTLED WEATHER ACROSS THE AREA WITH COOL HIGH PRESSURE ACROSS THE MIDWEST KEEPING UPSLOPE FLOW IN PLACE ACROSS EASTERN COLORADO ALONG WITH INCREASING MOISTURE WITHIN DEVELOPING SOUTHWEST FLOW ALOFT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1102 AM MDT FRI APR 17 2015 DRY AIR IS SPREADING ACROSS SOUTHERN AND EASTERN PORTIONS OF COLORADO RESULTING IN VFR CONDITIONS AT ALL THREE TAF SITES. MEANWHILE...WRAPPED UP INTENSE UPPER LOW WILL KEEP IFR TO LIFR AND HEAVY SNOW CONTINUING ACROSS THE CENTRAL MTS. GENERALLY SOUTHERLY WINDS CAN BE EXPECTED AT THE TAF SITES TODAY...THOUGH SHOWERS MAY SPREAD OFF THE MOUNTAINS INTO THE KCOS TAF SITE DURING THE AFTERNOON. IF THEY AFFECT THE TERMINAL...THEY SHOULD BE SHORT LIVED AND GIVEN THE ANTICIPATED SPOTTY NATURE...KCOS TAF WILL CARRY VCSH IN THE LATE AFTN/EARLY EVENING HOURS. WINDS WILL SHIFT OUT OF THE NORTH LATER TONIGHT FOR KCOS AND KPUB TAF SITES WITH WINDS GENERALLY UNDER 15 KTS. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058>063-072- 073-080-082. WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ077>079-084. RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ233-237. WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ076-081. WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ074-075. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ066. && $$ UPDATE...MOORE SHORT TERM...28 LONG TERM...MW AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1014 AM MDT FRI APR 17 2015 .UPDATE... ISSUED AT 1010 AM MDT FRI APR 17 2015 THE UPPER LOW OVER THE SW QUAD OF THE STATE IS CONTINUING TO SWEEP HEAVY SNOWFALL BACK INTO THE LAKE AND CHAFFEE COUNTY AREAS...AS PER LATEST SATELLITE IMAGERY AND SPOTTER REPORTS. THEREFORE...UPGRADED EXISTING SNOW ADVISORIES FOR LOWER PORTIONS OF LAKE AND CHAFFEE COUNTIES TO A WINTER STORM WARNING...IN EFFECT UNTIL 12Z TOMORROW MORNING. MOORE && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM MDT FRI APR 17 2015 THERE ARE SEVERAL CONCERNS FOR THE SHORT TERM FORECAST...INCLUDING THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS...THE POTENTIAL FOR SEVERE STORMS AND SNOW AMOUNTS. STILL SEE OCNL LIGHTNING STRIKES OVR SERN CO THIS MORNING. SATELLITE IMAGES SHOW THE UPR LOW CENTERED OVR NWRN NM THIS MORNING...AND IT IS FORECAST TO MOVE NORTHEASTWARD TODAY AND TONIGHT. BY 12Z SAT...THE NAM...GFS AND ECMWF SHOW THE LOW CENTER IN DIFFERENT LOCATIONS. THE GFS AND ECMWF ARE FAIRLY SIMILAR WITH THE LOW ABOUT OVR THE PALMER DVD...THE GFS IS A LITTLE FARTHER E AND S THAN THE ECMWF. THE NAM HAS THE LOW CENTER AT 12Z SAT OVR NRN SAGUACHE COUNTY. FOR THE FIRST HALF OF TODAY THE MODELS SHOW CONTINUED MOIST EASTERLY FLOW ACRS THE PIKES PEAK REGION...FREMONT COUNTY AND LAKE AND CHAFFEE COUNTIES...WITH SOME PCPN ALSO OVR THE SW MTNS AND SRN PORTIONS OF THE ERN MTNS...JUST NOT AS HEAVY AS NRN AREAS. AT THE SAME TIME...A DRY SLOT WL WORK ITS WAY INTO THE SERN PLAINS. HOWEVER...THE NAM HAS AN AREA OF CONVECTION DEVELOPING...MAINLY N OF HIGHWAY 50 OVR THE ERN PLAINS THIS AFTERNOON...WITH LAS ANIMAS AND BACA COUNTIES REMAINING DRY. THE GFS AND HRRR ARE DRY THIS AFTERNOON OVR THE FAR SERN PLAINS. STRONG SOUTHERLY WINDS OVR BACA AND LAS ANIMAS COUNTIES...ALONG WITH RH VALUES DROPPING BELOW 15 PERCENT ARE EXPECTED THIS AFTERNOON SO WL ISSUE A RED FLAG WARNING FOR THESE LOCATIONS. PORTIONS OF SRN PROWERS AND BENT COUNTIES MAY ALSO REACH RED FLAG CRITERIA...BUT UNCERTAINTY ABOUT PCPN OVR THESE COUNTIES WL KEEP ME FROM ISSUING A FIRE HIGHLIGHT AT THIS TIME. THE NAM DECREASES PCPN OVR MANY OF THE MTN AREAS THIS AFTERNOON...WHILE IT STILL LOOKS GOOD ON THE GFS OVR THE NRN MTNS PORTIONS OF THE CWA. THE ECMWF DECREASES PCPN OVR THE PIKES PEAK REGION BUT KEEPS GOOD PCPN GOING OVR LAKE AND CHAFFEE COUNTIES. THE GFS IS MUCH DRIER AT THE SFC THIS AFTERNOON OVR THE FAR SERN PLAINS THAN THE NAM...WHICH MAKES A DIFFERENCE IN THE POTENTIAL FOR SEVERE WX. WL LEAN THE FORECAST A LITTLE MORE TOWARD THE NAM OVR PROWERS...BENT...AND KIOWA COUNTIES. IF THE NAM IS CORRECT...CAPE VALUES COULD RANGE FROM ABOUT 600-1500 J/KG OVR PROWERS...NRN BENT AND KIOWA COUNTIES...WITH 0-6KM SHEAR VALUES OF 50-60 KTS...AND WE COULD SEE A COUPLE SEVERE STORMS. THE HRRR ALSO SETS UP A DRYLINE MAINLY NORTH OF HIGHWAY 50S THIS AFTERNOON OVR THE FAR SERN PLAINS. HOWEVER...IF THE DRIER GFS IS CORRECT THE BETTER MSTR AND SVR CHANCES WL BE EAST OF THE AREA. TONIGHT AS THE UPR LOW CONTINUES TO LIFT NORTHEASTWARD...MUCH OF THE SERN PLAINS LOOK TO BE DRY...WITH MANY OF THE MTN AREAS STILL SEEING SOME PCPN. ALTHOUGH THE DIFFERING POSITIONS OF THE UPR LOW CENTER RESULT IN DIFFERENCES IN WHAT MTNS AREAS WL HAVE THE BEST PCPN CHANCES. WILL NOT MAKE ANY CHANGES TO THE WINTER WEATHER HIGHLIGHTS THIS MORNING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 410 AM MDT FRI APR 17 2015 SATURDAY-SUNDAY...LATEST MODELS REMAIN IN DECENT AGREEMENT OF STRONG UPPER LOW ACROSS SOUTH CENTRAL COLORADO EARLY SATURDAY SLOWLY LIFTING NORTH AND EAST THROUGH SATURDAY NIGHT WITH THE SYSTEM THEN WEAKENING AND MERGING WITH A BROAD UPPER TROUGH TRANSLATING ACROSS THE NORTHERN TIER OF STATES. BEST CHANCES OF PRECIPITATION EARLY SATURDAY REMAINS ACROSS THE CONTDVD THROUGH THE SOUTHERN MTS WITH DEVELOPING WRAPAROUND PRECIPITATION SHIELD AND DEVELOPING NORTHWEST FLOW BEHIND THE PASSING SYSTEM. SHOULD SEE ISOLATED TO SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS THE EASTERN PLAINS SATURDAY AFTERNOON AND EVENING WITH COLD CORE UPPER LOW TRANSLATING INTO NORTHEASTERN COLORADO. MAY NEED TO EXTEND OR ADD WINTER HIGHLIGHTS ACROSS THE CENTRAL MTS INTO SATURDAY WITH SEVERAL INCHES OF SNOW EXPECTED...ESPECIALLY AOA 10KT FEET. MID LEVEL TEMPS SLOWLY WARM SATURDAY AS THE SYSTEM LIFTS OUT ACROSS THE AREA AND SHOULD SEE HIGHS SLIGHTLY WARMER AS A RESULT...THOUGH STILL BELOW SEASONAL AVERAGES. PASSING UPPER SYSTEM ACROSS THE AREA LATE SATURDAY SENDS A COLD FRONT ACROSS THE EASTERN PLAINS EARLY SUNDAY MORNING...WITH GUSTY NORTH TO NORTHWEST WINDS OF 20 TO 40 MPH EXPECTED IN ITS WAKE...WITH THE STRONGEST WINDS EXPECTED ACROSS THE FAR EASTERN PLAINS. A MINOR WAVE EMBEDDED WITHIN THE NORTHWEST FLOW ALOFT SUPPORTS ISOLATED TO SCATTERED SHOWERS ACROSS THE AREA ON SUNDAY...WITH TEMPERATURES SLIGHTLY COOLER THAN SATURDAY. MONDAY-TUESDAY...EMBEDDED DISTURBANCES IN THE SLOWLY MODERATING NORTHWEST FLOW ACROSS THE AREA WILL KEEP ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS IN THE FORECAST WITH TEMPERATURES WARMING BACK TO NEAR SEASONAL AVERAGES. WEDNESDAY-THURSDAY...A REX LIKE BLOCKING PATTERN LOOKS TO SET UP ACROSS THE REGION WITH RIDGING ACROSS THE ROCKIES AND TROUGHS SETTING UP OVER THE COASTS. THIS LOOKS TO KEEP UNSETTLED WEATHER ACROSS THE AREA WITH COOL HIGH PRESSURE ACROSS THE MIDWEST KEEPING UPSLOPE FLOW IN PLACE ACROSS EASTERN COLORADO ALONG WITH INCREASING MOISTURE WITHIN DEVELOPING SOUTHWEST FLOW ALOFT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 410 AM MDT FRI APR 17 2015 KCOS WL MAINLY HAVE MVFR CONDITIONS THIS MORNING WITH THE POTENTIAL FOR SNOW SHOWERS OR A MIX OF RAIN AND SNOW. THIS AFTERNOON FORECAST SOUNDINGS SHOW A RETURN TO VFR CONDITIONS THROUGH EARLY EVENING...AND THEN THE POTENTIAL FOR MVFR CONDITIONS DEVELOPING AGAIN. KPUB SHOULD GENERALLY HAVE MVFR CONDITIONS WITH THE POTENTIAL FOR RAIN SHOWERS AND MAYBE EVEN A THUNDERSTORM. FORECAST SOUNDINGS SHOW A RETURN TO VFR CONDITIONS IN THE LATE MORNING HOURS AND THROUGH THE REST OF THE PERIOD. KALS SHOULD GENERALLY SEE VFR CONDITIONS UNTIL LATE TONIGHT...WHEN THERE WILL BE THE POTENTIAL FOR MVFR OR IFR CONDITIONS. BREEZY SOUTHWEST WINDS ARE EXPECTED THIS AFTERNOON. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058>063-072- 073-080-082. WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ077>079-084. RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ233-237. WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ076-081. WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ074-075. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ066. && $$ UPDATE...MOORE SHORT TERM...28 LONG TERM...MW AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
410 AM MDT FRI APR 17 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 410 AM MDT FRI APR 17 2015 THERE ARE SEVERAL CONCERNS FOR THE SHORT TERM FORECAST...INCLUDING THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS...THE POTENTIAL FOR SEVERE STORMS AND SNOW AMOUNTS. STILL SEE OCNL LIGHTNING STRIKES OVR SERN CO THIS MORNING. SATELLITE IMAGES SHOW THE UPR LOW CENTERED OVR NWRN NM THIS MORNING...AND IT IS FORECAST TO MOVE NORTHEASTWARD TODAY AND TONIGHT. BY 12Z SAT...THE NAM...GFS AND ECMWF SHOW THE LOW CENTER IN DIFFERENT LOCATIONS. THE GFS AND ECMWF ARE FAIRLY SIMILAR WITH THE LOW ABOUT OVR THE PALMER DVD...THE GFS IS A LITTLE FARTHER E AND S THAN THE ECMWF. THE NAM HAS THE LOW CENTER AT 12Z SAT OVR NRN SAGUACHE COUNTY. FOR THE FIRST HALF OF TODAY THE MODELS SHOW CONTINUED MOIST EASTERLY FLOW ACRS THE PIKES PEAK REGION...FREMONT COUNTY AND LAKE AND CHAFFEE COUNTIES...WITH SOME PCPN ALSO OVR THE SW MTNS AND SRN PORTIONS OF THE ERN MTNS...JUST NOT AS HEAVY AS NRN AREAS. AT THE SAME TIME...A DRY SLOT WL WORK ITS WAY INTO THE SERN PLAINS. HOWEVER...THE NAM HAS AN AREA OF CONVECTION DEVELOPING...MAINLY N OF HIGHWAY 50 OVR THE ERN PLAINS THIS AFTERNOON...WITH LAS ANIMAS AND BACA COUNTIES REMAINING DRY. THE GFS AND HRRR ARE DRY THIS AFTERNOON OVR THE FAR SERN PLAINS. STRONG SOUTHERLY WINDS OVR BACA AND LAS ANIMAS COUNTIES...ALONG WITH RH VALUES DROPPING BELOW 15 PERCENT ARE EXPECTED THIS AFTERNOON SO WL ISSUE A RED FLAG WARNING FOR THESE LOCATIONS. PORTIONS OF SRN PROWERS AND BENT COUNTIES MAY ALSO REACH RED FLAG CRITERIA...BUT UNCERTAINTY ABOUT PCPN OVR THESE COUNTIES WL KEEP ME FROM ISSUING A FIRE HIGHLIGHT AT THIS TIME. THE NAM DECREASES PCPN OVR MANY OF THE MTN AREAS THIS AFTERNOON...WHILE IT STILL LOOKS GOOD ON THE GFS OVR THE NRN MTNS PORTIONS OF THE CWA. THE ECMWF DECREASES PCPN OVR THE PIKES PEAK REGION BUT KEEPS GOOD PCPN GOING OVR LAKE AND CHAFFEE COUNTIES. THE GFS IS MUCH DRIER AT THE SFC THIS AFTERNOON OVR THE FAR SERN PLAINS THAN THE NAM...WHICH MAKES A DIFFERENCE IN THE POTENTIAL FOR SEVERE WX. WL LEAN THE FORECAST A LITTLE MORE TOWARD THE NAM OVR PROWERS...BENT...AND KIOWA COUNTIES. IF THE NAM IS CORRECT...CAPE VALUES COULD RANGE FROM ABOUT 600-1500 J/KG OVR PROWERS...NRN BENT AND KIOWA COUNTIES...WITH 0-6KM SHEAR VALUES OF 50-60 KTS...AND WE COULD SEE A COUPLE SEVERE STORMS. THE HRRR ALSO SETS UP A DRYLINE MAINLY NORTH OF HIGHWAY 50S THIS AFTERNOON OVR THE FAR SERN PLAINS. HOWEVER...IF THE DRIER GFS IS CORRECT THE BETTER MSTR AND SVR CHANCES WL BE EAST OF THE AREA. TONIGHT AS THE UPR LOW CONTINUES TO LIFT NORTHEASTWARD...MUCH OF THE SERN PLAINS LOOK TO BE DRY...WITH MANY OF THE MTN AREAS STILL SEEING SOME PCPN. ALTHOUGH THE DIFFERING POSITIONS OF THE UPR LOW CENTER RESULT IN DIFFERENCES IN WHAT MTNS AREAS WL HAVE THE BEST PCPN CHANCES. WILL NOT MAKE ANY CHANGES TO THE WINTER WEATHER HIGHLIGHTS THIS MORNING. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 410 AM MDT FRI APR 17 2015 SATURDAY-SUNDAY...LATEST MODELS REMAIN IN DECENT AGREEMENT OF STRONG UPPER LOW ACROSS SOUTH CENTRAL COLORADO EARLY SATURDAY SLOWLY LIFTING NORTH AND EAST THROUGH SATURDAY NIGHT WITH THE SYSTEM THEN WEAKENING AND MERGING WITH A BROAD UPPER TROUGH TRANSLATING ACROSS THE NORTHERN TIER OF STATES. BEST CHANCES OF PRECIPITATION EARLY SATURDAY REMAINS ACROSS THE CONTDVD THROUGH THE SOUTHERN MTS WITH DEVELOPING WRAPAROUND PRECIPITATION SHIELD AND DEVELOPING NORTHWEST FLOW BEHIND THE PASSING SYSTEM. SHOULD SEE ISOLATED TO SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS ACROSS THE EASTERN PLAINS SATURDAY AFTERNOON AND EVENING WITH COLD CORE UPPER LOW TRANSLATING INTO NORTHEASTERN COLORADO. MAY NEED TO EXTEND OR ADD WINTER HIGHLIGHTS ACROSS THE CENTRAL MTS INTO SATURDAY WITH SEVERAL INCHES OF SNOW EXPECTED...ESPECIALLY AOA 10KT FEET. MID LEVEL TEMPS SLOWLY WARM SATURDAY AS THE SYSTEM LIFTS OUT ACROSS THE AREA AND SHOULD SEE HIGHS SLIGHTLY WARMER AS A RESULT...THOUGH STILL BELOW SEASONAL AVERAGES. PASSING UPPER SYSTEM ACROSS THE AREA LATE SATURDAY SENDS A COLD FRONT ACROSS THE EASTERN PLAINS EARLY SUNDAY MORNING...WITH GUSTY NORTH TO NORTHWEST WINDS OF 20 TO 40 MPH EXPECTED IN ITS WAKE...WITH THE STRONGEST WINDS EXPECTED ACROSS THE FAR EASTERN PLAINS. A MINOR WAVE EMBEDDED WITHIN THE NORTHWEST FLOW ALOFT SUPPORTS ISOLATED TO SCATTERED SHOWERS ACROSS THE AREA ON SUNDAY...WITH TEMPERATURES SLIGHTLY COOLER THAN SATURDAY. MONDAY-TUESDAY...EMBEDDED DISTURBANCES IN THE SLOWLY MODERATING NORTHWEST FLOW ACROSS THE AREA WILL KEEP ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS IN THE FORECAST WITH TEMPERATURES WARMING BACK TO NEAR SEASONAL AVERAGES. WEDNESDAY-THURSDAY...A REX LIKE BLOCKING PATTERN LOOKS TO SET UP ACROSS THE REGION WITH RIDGING ACROSS THE ROCKIES AND TROUGHS SETTING UP OVER THE COASTS. THIS LOOKS TO KEEP UNSETTLED WEATHER ACROSS THE AREA WITH COOL HIGH PRESSURE ACROSS THE MIDWEST KEEPING UPSLOPE FLOW IN PLACE ACROSS EASTERN COLORADO ALONG WITH INCREASING MOISTURE WITHIN DEVELOPING SOUTHWEST FLOW ALOFT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 410 AM MDT FRI APR 17 2015 KCOS WL MAINLY HAVE MVFR CONDITIONS THIS MORNING WITH THE POTENTIAL FOR SNOW SHOWERS OR A MIX OF RAIN AND SNOW. THIS AFTERNOON FORECAST SOUNDINGS SHOW A RETURN TO VFR CONDITIONS THROUGH EARLY EVENING...AND THEN THE POTENTIAL FOR MVFR CONDITIONS DEVELOPING AGAIN. KPUB SHOULD GENERALLY HAVE MVFR CONDITIONS WITH THE POTENTIAL FOR RAIN SHOWERS AND MAYBE EVEN A THUNDERSTORM. FORECAST SOUNDINGS SHOW A RETURN TO VFR CONDITIONS IN THE LATE MORNING HOURS AND THROUGH THE REST OF THE PERIOD. KALS SHOULD GENERALLY SEE VFR CONDITIONS UNTIL LATE TONIGHT...WHEN THERE WILL BE THE POTENTIAL FOR MVFR OR IFR CONDITIONS. BREEZY SOUTHWEST WINDS ARE EXPECTED THIS AFTERNOON. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ059-062- 063-074-075. WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ077>079-084. RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR COZ233-237. WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058-060-061- 072-073-080-082. WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ076-081. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ066. && $$ SHORT TERM...28 LONG TERM...MW AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1141 PM MDT THU APR 16 2015 .UPDATE... ISSUED AT 930 PM MDT THU APR 16 2015 UPDATED TO MAKE SOME MINOR ADJUSTMENTS TO POPS THROUGH TOMORROW BASED ON RADAR TRENDS AND 00Z GUIDANCE. LOOKS LIKE THE SVR THREAT IS OVER FOR NOW...BUT COULD STILL SEE SOME ISOLD TS OVER THE SE PLAINS TONIGHT. STILL EXPECTING SOME DRY AIR TO PUSH INTO SE CO TOMORROW...BUT THERE WILL BE SCT SHOWERS AROUND IN THE MORNING. MAIN AREA TO WATCH THROUGH TOMORROW WILL BE THE UPPER ARKANSAS AND GUNNISON VALLEY...WHERE SOME GUIDANCE IS SHOWING A PERSISTENT SNOW BAND DEVELOPING. ROSE UPDATE ISSUED AT 543 PM MDT THU APR 16 2015 UPDATED THE FORECAST TO INCLUDE TELLER COUNTY AND NORTHERN FREMONT COUNTY IN A WINTER STORM WARNING. MULTIPLE BANDS OF PRECIP EXPECTED TO ROTATE IN FROM THE SE TONIGHT...WITH VARIOUS MODELS SHOWING .7 TO 1.4 INCHES OF QPF. WITH COOLING TEMPS AFTER SUNSET EXPECT ROADS TO ICE OVER...LEADING TO HAZARDOUS TRAVEL IN THE WARNED AREAS. ROSE UPDATE ISSUED AT 423 PM MDT THU APR 16 2015 UPDATED THE FORECAST TO CANCEL THE RED FLAG FOR THE SAN LUIS VALLEY. SCATTERED SHOWERS ARE OVER THE VALLEY AND HUMIDITY IS NO LONGER CRITICAL. ROSE && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 356 PM MDT THU APR 16 2015 ...MODERATE TO HEAVY SNOW POSSIBLE FOR THE MOUNTAINS TONIGHT AND FRIDAY... ...CRITICAL FIRE WEATHER CONDITIONS POSSIBLE FOR THE FAR SOUTHEAST PLAINS AGAIN ON FRIDAY THOUGH THIS IS DEPENDENT ON HOW MUCH RAIN FALLS OVER THESE AREAS TONIGHT... ...MARGINAL POTENTIAL FOR SEVERE POSSIBLE FOR NORTHERN EL PASO AND KIOWA COUNTIES ON FRIDAY... STILL A HIGHLY DYNAMIC FORECAST AS MODELS HONE IN ON TRACK AND STRENGTH OF THE CLOSED LOW CURRENTLY ACROSS THE 4 CORNERS REGION. MODELS BOBBLE THE UPPER LOW SOUTHWARD A BIT THIS EVENING...THEN BACK TO THE NORTHEAST ACROSS THE CO/NM BORDER TONIGHT AS ENERGY ROTATES AROUND THE BASE OF THE UPPER LOW AND ACROSS CO. THEN IT MAKES STEADIER PROGRESS TO THE NORTHEAST INTO EAST CENTRAL CO ON FRIDAY. ALREADY SEEING ENHANCEMENT ACROSS THE SOUTHEAST MTS AND NRN NM AS THE NEXT IMPULSE APPROACHES. HRRR SEEMS TO HAVE PICKED UP ON THIS TREND FAIRLY WELL. WE SHOULD CONTINUE TO SEE SHOWERS FILL IN ACROSS THE SOUTHEAST MOUNTAINS...AND I-25 CORRIDOR...WITH SNOW LEVELS AROUND 6000-6500 FEET. SNOW LEVELS MAY ACTUALLY RISE A BIT FOR THE LOWER EASTERN SLOPES AS STRONG WAA OCCURS OVERNIGHT...WHICH COULD CAUSE A SWITCH BACK TO RAIN AT KCOS OVERNIGHT. HOWEVER...MTN AREAS SHOULD CONTINUE TO SEE SNOW AND HAVE EXPANDED ADVISORIES ACROSS MUCH OF THE MOUNTAIN AREAS. GIVEN THE CONVECTIVE POTENTIAL WITH THIS EVENINGS ROUND...CONCERNED THAT PORTIONS OF TELLER COUNTY COULD HIT WARNING CRITERIA...THOUGH DON`T THINK IT WILL BE WIDESPREAD ENOUGH ACROSS THE ZONE TO WARRANT AN UPGRADE. CENTRAL LAKE COUNTY COULD BE IN A SIMILAR BOAT...SO THESE AREAS WILL BE THE ONES TO WATCH CLOSELY. MEANWHILE...MODELS SHOW DEFORMATION BAND SNOW SPREADING WESTWARD INTO THE SOUTHWEST MOUNTAINS TONIGHT AND CONTINUING THROUGH FRIDAY. HAVE OPTED TO EXPAND ADVISORIES INTO THE LA GARITAS WHERE SNOW AMOUNTS ARE APPROACHING THE 6-12 INCH RANGE. STILL SOME QUESTION OVER THE EASTERN SAN JUANS THOUGH...COULD SEE A COUPLE INCHES FALL THERE TONIGHT...WITH ANOTHER 1-3 INCHES FALLING ON FRIDAY AS THE UPPER LOW WRAPS DEFORMATION BAND BACK TO THE SOUTHWEST ACROSS THE REGION. CONTEMPLATED AN ADVISORY FOR THIS REGION...BUT AM COMING UP SHY OF THE 6-12 INCHES NEEDED FOR A WINTER WX ADVISORY...THOUGH CERTAINLY SUBTLE CHANGES IN THE TRACK AND STRENGTH OF THE LOW COULD RESULT IN HEAVIER AMOUNTS FOR THIS REGION. STICKING TRUE TO THE GRIDS FOR NOW AND WILL LET LATER SHIFTS REASSESS. AS FOR SEVERE THUNDERSTORM POTENTIAL ACROSS THE PLAINS...APPEARS TIMING OF THE INITIAL WAVE THIS AFTERNOON WAS TOO QUICK FOR THE LOW LEVEL MOISTURE RETURN...AND NICE LINE OF THUNDERSTORMS HAS ALREADY DEVELOPED AND PUSHED EASTWARD INTO KANSAS. HOWEVER AS SURFACE WINDS HAVE VEERED MORE EASTERLY DUE TO FALLING SFC PRESSURES ACROSS NEW MEXICO...40S AND LOWER 50 DEW POINTS HAVE PULLED WESTWARD INTO THE FAR SOUTHEAST PLAINS. ACTIVITY INCREASING ACROSS NORTHERN NEW MEXICO MAY STILL HAVE A CHANCE TO INTERACT WITH THIS MOISTURE TO PRODUCE SOME ISOLATED SEVERE THUNDERSTORMS...WITH HAIL AND GUSTY WINDS THE PRIMARY STORM THREATS. OVERNIGHT...LATEST HRRR HINTS AT ANOTHER ROUND CLIPPING BY BACA COUNTY DURING THE 8Z TO 09Z TIMEFRAME...AND EVEN SOME SPOTTY THUNDERSTORMS POSSIBLE AS FAR WEST AS THE I-25 CORRIDOR. SO THOUGH MAIN THREAT FOR SEVERE THUNDERSTORMS WILL BE THIS EVENING...CAN`T RULE OUT A LOW GRADE SEVERE THREAT ACROSS THE FAR SOUTHEAST PLAINS EVEN DURING THE OVERNIGHT HOURS...THOUGH THUNDERSTORMS WILL TEND TO BE MORE ELEVATED. TOMORROW AS THE SURFACE LOW LIFTS INTO SOUTHEAST CO...COULD SEE SOME ISOLATED THUNDERSTORMS EVEN IN THE MORNING...AND LAPSE RATES WILL BE STEEP GIVEN THE MID LEVEL COOLING ASSOCIATED WITH THE SURFACE LOW. NAM12 SHOWS UP TO 1000 J/KG OF CAPE ACROSS NORTHERN PORTIONS OF THE SE PLAINS DURING THE MORNING...SO COULD HAVE ANOTHER CHANCE FOR SEVERE THUNDERSTORMS ON FRIDAY. BY AFTERNOON...DRY AIR SPREADS INTO THE SOUTHEAST PLAINS AS SURFACE LOW LIFTS NORTHWARD. THIS PUTS THE AXIS OF BEST INSTABILITY ALONG THE NORTHERN FRINGES OF THE SOUTHEAST PLAINS BY AFTERNOON...PRIMARILY NORTHEAST EL PASO AND KIOWA COUNTIES. THESE AREAS ARE OUTLOOKED FOR A MARGINAL SEVERE THREAT TOMORROW...AND THIS LOOKS ON TARGET. COULD SEE THIS MARGINAL THREAT SLIPPING SOUTHWARD A BIT TO ACCOUNT FOR ANY STRONG MORNING CONVECTION. BUT AS DRY AIR EXPANDS NORTHWARD...SO DOES THE POTENTIAL FOR CRITICAL FIRE WEATHER PARAMETERS...ESPECIALLY ACROSS LAS ANIMAS...BACA...BENT...PROWERS... AND OTERO COUNTIES. THE MITIGATING FACTOR WILL BE THE POTENTIAL FOR RAINFALL TO WET FUELS TONIGHT OVER THESE SAME ZONES. GIVEN THIS POTENTIAL...HAVE NOT GONE OUT WITH A FIRE WEATHER WATCH...BUT IF PRECIPITATION DOESN`T MATERIALIZE ACROSS A WIDESPREAD ENOUGH AREA ACROSS THESE REGION...THEN LATER SHIFTS MAY NEED TO HOIST A RED FLAG WARNING. -KT .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 356 PM MDT THU APR 16 2015 FRIDAY NIGHT THROUGH SATURDAY...MODELS HAVE SHIFTED A BIT OVER THE PST 24 HRS...BUT STILL REMAIN FAIRLY CONSISTENT WITH THE PLACEMENT AND PATH OF THE UPPER LOW. FRIDAY NIGHT THE LOW PRESSURE SYSTEM IS FORECAST TO BE CENTERED RIGHT OVER COLORADO...THEN OVER THE NEXT 24 HRS IT WILL WOBBLE A BIT BEFORE SLOWLY EXITING THE STATE VIA THE EASTERN BORDER. THIS PATTERN WOULD IMPLY THAT THE MTS...ESPECIALLY THE CONTDVD...WILL GET THE BRUNT OF SNOWFALL...MAINLY THROUGH FRIDAY NIGHT. THEREFORE...ONGOING WINTER HIGHLIGHTS RUNNING THROUGH 12Z SATURDAY LOOK REASONABLE. SNOW AMOUNTS WILL THEN TAPER OVER OVER THE DAY SATURDAY AS TEMPS BEGIN TO WARM AND THE SYSTEM WEAKENS. ISOLATED TO SCATTERED SHOWERS ARE FORECAST FOR THE REMAINDER OF THE LOWER ELEVATIONS...AND TEMPS DO NOT LOOK PARTICULARLY COLD WITH MIN TEMPS IN THE 30S TO AROUND 40 F FOR THE PLAINS...AND MAX TEMPS SATURDAY IN THE MID 50S TO LOWER 60S. SUNDAY AND MONDAY...THE UPPER SYSTEM WEAKENS AND EXITS TO THE EAST LATE SATURDAY...WITH BRISK NW FLOW ALOFT THEN SETTLING IN ACROSS THE STATE. A COUPLE OF UPPER SHORTWAVES ARE EXPECTED TO DROP DOWN ACROSS THE STATE ON BOTH DAYS...KEEPING THE THREAT OF SHOWER ACTIVITY FOR THE CWA IN PLACE. LOOK FOR SCATTERED SHOWERS OVER THE HIGHER TERRAIN...AND ISOLATED SHOWERS FOR THE PLAINS...WITH MAX TEMPS BOTH DAYS HOVERING IN THE 50S TO NEAR 60 F. TUESDAY THROUGH THURSDAY...CONFIDENCE IS FAIRLY LOW FOR WHAT HAPPENS BEYOND MONDAY...THOUGH LONG RANGE MODELS SEEM TO AGREE ON THE QUESTION MARK. A TEMPORARY RIDGE BUILDS INTO THE DESERT SW STARTING TUE...HELPING TO LOWERING PCPN CHANCES AS WELL AS BOOSTING MAX TEMPS FOR THE PLAINS BACK INTO THE 70S. TWO SEPARATE UPPER CLOSED LOW SYSTEMS APPROACH STARTING WED NIGHT...ONE OVER THE PAC NW AND THE OTHER OVER S CA...BUT THIS PATTERN WILL MOST LIKELY GO THROUGH MULTIPLE ADJUSTMENTS BEFORE THEN. MOORE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1128 PM MDT THU APR 16 2015 LARGE UPPER LOW SPINNING NEAR THE 4 CORNERS REGION WILL PRODUCE WIDESPREAD MVFR/IFR AND LOCAL LIFR CONDITIONS ACROSS THE FLIGHT AREA THROUGH THROUGH TONIGHT AND UP THROUGH ABOUT 18Z FRIDAY. AFTER 18Z...IT LOOKS LIKE THE FOCUS FOR THESE CONDITIONS WILL SHIFT MAINLY TO THE WESTERN MOUNTAINS...WITH CONDITIONS ELSEWHERE IMPROVING TO VFR...WITH JUST ISOLATED TO SCATTERED MVFR/IFR. THE KCOS...KPUB AND KALS TAF SITES SHOULD ALL FOLLOW THIS TREND...WITH IMPROVEMENT EXPECTED AFTER 18Z FRIDAY. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY FOR COZ059-062- 063-074-075. WINTER WEATHER ADVISORY UNTIL 6 PM MDT FRIDAY FOR COZ077>079-084. WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR COZ058-060-061- 072-073-080-082. WINTER STORM WARNING UNTIL MIDNIGHT MDT FRIDAY NIGHT FOR COZ076- 081. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT FRIDAY NIGHT FOR COZ066. && $$ UPDATE...ROSE SHORT TERM...KT LONG TERM...MOORE AVIATION...LW
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
445 AM EDT FRI APR 17 2015 .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UPPER LEVEL PATTERN THAT HAS CHANGED LITTLE OVER THE PAST 24 HOURS. NORTHERN STREAM WESTERLIES REMAIN MOSTLY ZONAL TO THE NORTH OF THE CANADIAN BORDER...WHILE MOIST SOUTHERN STREAM WESTERLIES CROSS OVER NORTHERN MEXICO FROM THE CENTRAL PACIFIC...AND THEN MOVE ALONG THE NORTHERN GULF COAST/SOUTHEAST CONUS. BETWEEN THESE TWO BELTS OF WESTERLIES...A LARGE CUTOFF LOW CENTERED OVER THE FOUR CORNERS REGION CONTINUES TO SPIN AND EJECT PIECES OF ENERGY OUT INTO THE SOUTHERN/CENTRAL PLAINS. A SERIES OF UPPER LEVEL IMPULSE ARE ALSO RIDING THE SOUTHERN STREAM FLOW AND FORCING PERIODIC FLARES OF CONVECTION OVER THE NORTH-CENTRAL GULF. THESE CONVECTIVE BURST WILL MAKE OUR LOCAL FORECAST A BIT TRICKY INTO SATURDAY AS WILL BE EXPLAINED IN THE SHORT TERM DISCUSSION BELOW. AT THE SURFACE...A COMPLEX PRESSURE PATTERN EXISTS JUST TO OUR NORTH AND NORTHEAST WITH A WEDGE HIGH IN PLACE ACROSS THE SOUTHEAST CONUS AND AN AREA OF LOW PRESSURE ANALYZED JUST OFF THE GA/SC COAST. THE FLOW AROUND THESE FEATURES HAS KEPT A WEAK FRONTAL BOUNDARY IN PLACE ACROSS NORTH-CENTRAL FLORIDA...BISECTING OUR FORECAST AREA FROM EAST TO WEST. THERE ARE AREAS OF LOWER CLOUDS EARLY THIS MORNING ALONG AND TO THE NORTH OF THIS BOUNDARY THAT WILL BE OF SOME CONCERN TO THE AVIATION COMMUNITY...ALTHOUGH THESE CIGS SHOULD LIFT QUICKLY...WITHIN A FEW HOURS OF SUNRISE. REGIONAL RADARS SHOW THAT THE LAST OF THE THURSDAY RESIDUAL SHOWER ACTIVITY ASSOCIATED WITH THE WEAK FRONT AND SEA BREEZES HAS DISSIPATED...LEAVING MOST OF THE FL PENINSULA DRY. HOWEVER...OFF TO THE NORTHWEST ACROSS THE NE GULF AND FL PANHANDLE WE SEE A BLOSSOMING AREA OF RAIN/EMBEDDED STORMS EXPANDING EASTWARD TOWARD THE NORTHERN NATURE COAST ZONES. THIS AREA OF RAIN LOOKS INCREASINGLY LIKELY TO IMPACT OUR NORTHERN NATURE COAST ZONES THIS MORNING. && .SHORT TERM (TODAY THROUGH SATURDAY)... TODAY...FIRST THINGS FIRST. THE FORECAST CONCERN FOR THE MORNING HOURS IS THE LARGE AREA OF RAIN OVER THE FL PANHANDLE/NORTHEAST GULF OF MEXICO. THIS CONVECTION CAN BE ATTRIBUTED TO THE SYNOPTIC LIFT ASSOCIATED WITH A SUBTLE SHORTWAVE PASSING OVER THE NORTH-CENTRAL GULF COAST...AND THE LOWER LEVEL RESPONSE OF A STRENGTHENING JET RESULTING IN A BROAD WAA/LIFT REGIME. THE MOST EFFICIENT LIFT WITH THE SHORTWAVE LOOKS TO PASS OFF TO OUR NORTH...HOWEVER...IT IS BECOMING MORE AND MORE EVIDENT THAT AT LEAST SOME OF THIS ACTIVITY WILL REACH OUR NORTHERN NATURE COAST ZONES...MAINLY LEVY/CITRUS/NORTHERN SUMTER. THE RAP AND HRRR FOR SEVERAL RUNS NOW HAVE BEEN AGGRESSIVE IN BRINGING THIS MOISTURE EASTWARD INTO THESE AREA AFTER 11-12Z. IT IS HARD TO ARGUE WITH THIS SOLUTION GIVEN THE CURRENT RADAR TRENDS. HAVE BUMPED UP RAIN CHANCES TO LIKELY OVER OUR FAR NORTHERN ZONES THIS MORNING TO ACCOUNT FOR THIS. NOW...THE ARRIVAL OF THIS RAINFALL...WHICH IS NOT HANDLED WELL BY MANY OF THE 00Z GUIDANCE MEMBERS...MAKES THE FORECAST TRICKY FOR THE AFTERNOON HOURS FURTHER SOUTH INTO THE I-4 CORRIDOR AND PERHAPS FURTHER SOUTH. THERE ARE TWO POSSIBILITIES. ONE IS THAT THE SHOWER ACTIVITY SLOWS THE DIURNAL HEATING ACROSS THE NATURE COAST AND ACTUALLY ENDS UP FORCING WEAK FRONTOGENESIS ALONG THE BOUNDARY DUE TO DIFFERENTIAL DIURNAL HEATING. IN THIS CASE THE SHOWERS/STORMS ACTIVITY INTO THE CENTRAL FORECAST AREA COULD BE ENHANCED (EVEN BACK TOWARD THE COAST). THE LATEST 07Z HRRR SOLUTION IS SHOWING SOMETHING SIMILAR TO THIS. THE SECOND POSSIBILITY IS THAT THE RAINFALL COOLING AND MOMENTUM ARE ENOUGH TO PUSH AN OUTFLOW BOUNDARY SOUTH THROUGH THE CENTRAL PENINSULA AND ACT TO INHIBIT ADDITIONAL CONVECTIVE DEVELOPMENT THIS AFTERNOON IN ITS WAKE. METEOROLOGY IS NEVER AN EXACT SCIENCE...AND THIS IS A TRICKY FORECAST TO SAY THE LEAST. IT IS LIKELY BEST IN THIS SCENARIO NOT TO GET TOO HUNG UP ON DETAILS...SINCE THIS JUST IS NOT A PATTERN WHERE THAT IS REALISTIC. SO...WILL GO WITH LIKELY RAIN CHANCES FAR NORTH THIS MORNING...WITH THE ENERGY AND HIGHEST RAIN CHANCES THEN PASSING OUT OF THESE AREA FOR THE AFTERNOON. FURTHER SOUTH...WILL EXPECT SOME ENHANCEMENT ALONG THE BOUNDARY FROM THE NORTH AND SOME SEA-BREEZE INTERACTION FURTHER SOUTH. IT APPEARS AS THROUGH THE SOUTHERN HALF OF THE AREA WILL HAVE THE BEST CHANCES AT A DEFINED SEA-BREEZE LATER TODAY. SO SOUTH OF THE I-4 CORRIDOR...THE BEST RAIN CHANCES WILL BE LATE AFTERNOON AND EVENING HOURS...AND GENERALLY INLAND AWAY FROM THE COAST. TONIGHT...SITUATION REMAIN TRICKY. THE QUESTION IS DO WE BELIEVE THE PARAMETERIZED GUIDANCE OR THE CONVECTION ALLOWING GUIDANCE? THE PARAMETERIZED GUIDANCE WOULD SUGGEST EVENING STORMS SETTLE DOWN AND MOST OF THE OVERNIGHT IS BENIGN IN TERMS OF SENSIBLE WEATHER. MANY OF THE HIRES CONVECTION ALLOWING MEMBERS SHOW A ROUND OF STORMS QUICKLY CROSSING THE NE GULF AND INTO THE NATURE COAST (EVEN AS FAR SOUTH AS THE TAMPA BAY AREA). THESE STORMS DEVELOP ALONG THE FOCUS OF A LARGE OUTFLOW SURGE INITIATED OFF THE LOUISIANA COAST TODAY. IT IS SURPRISING HOW MANY MEMBERS ARE SHOWING A SIMILAR SCENARIO. HOWEVER...SO MANY THINGS HAVE TO COME TOGETHER FOR THIS CONVECTIVE BLOB TO EVEN EXIST...INCLUDING THE PROPER PLACEMENT AND TIMING OF THE CONVECTION OF THE LOUISIANA COAST. TOO MANY UNCERTAINTIES HERE...AND HIRES GUIDANCE IS OFTEN OVER AGGRESSIVE IN THESE TYPE OF CASES. WILL ALLOW FOR LOW END POPS OVER THE NATURE COAST TONIGHT...BUT LEAN MORE TOWARD THE BENIGN GFS/NAM/ECMWF SOLUTIONS UNTIL WE SEE EVIDENCE TO GO AGAINST THESE RELIABLE SOURCES. SATURDAY...WELCOME TO THE WEEKEND. HEIGHT FALLS OVER THE SOUTHERN PLAINS ASSOCIATED WITH THE EASTWARD EJECTING CUTOFF LOW WILL ACTUALLY HELP TO RIDGE UP THE UPPER FLOW OVER OUR AREA. SO WHILE PLENTY OF SHOWER/STORM ACTIVITY WILL BE ONGOING ACROSS THE NORTH- CENTRAL GULF...THIS ORGANIZED CONVECTION WILL NOT BE ABLE TO COME EASTWARD JUST YET. ALSO...OUR SURFACE BOUNDARY LOOKS TO BE JUST ABOUT GONE BY THIS TIME...WITH A VERY WEAK GRADIENT LEFT BEHIND. THE WEAK GRADIENT MEANS OUR FLOW WILL BE DOMINATED BY THE DEVELOPING AFTERNOON SEA-BREEZES. JUST ABOVE THE SURFACE THE PREVAILING FLOW WILL BE FRONT THE WEST...SO THE WEST COAST SEA BREEZE SHOULD QUICKLY TRANSLATE INLAND AFTER INITIATION. WITH THIS IN MIND...WILL KEEP THE BEST CHANCE OF DIURNAL STORMS SATURDAY AFTERNOON/EVENING GENERALLY WELL INLAND...WITH ONLY LOW RAIN CHANCES BACK TOWARD THE COAST. EVEN THESE LOW POPS SHOULD END BY MID/LATE AFTERNOON IN THE WAKE OF THE SEA BREEZE PASSAGE. && .LONG TERM (SUNDAY THROUGH NEXT THURSDAY)... THE WEEKEND FINISHES WITH AN UPPER TROUGH OVER THE NORTH AND CENTRAL HIGH PLAINS WHILE A RIDGE REACHES FROM THE EAST GULF TO THE UPPER GREAT LAKES. A SURFACE LOW IN THE CENTRAL PLAINS HAS A COLD FRONT THAT ARCS DOWN THROUGH THE MISSISSIPPI VALLEY AND INTO THE GULF. HIGH PRESSURE IN EASTERN CANADA RIDGES SOUTH TO FL...BRIDGING A WARM FRONT LIKE BOUNDARY OVER GA AND NW FL COASTAL WATERS. THROUGH TUE - THE UPPER TROUGH AND SURFACE LOW LIFT UP OUT OF THE PLAINS AND ACROSS THE GREAT LAKES INTO CANADA...WITH THE COLD FRONT PUSHING EAST AND OFF THE EASTERN SEABOARD AND SETTLING SOUTHWARD OVER FL. THE UPPER RIDGE AND CANADIAN HIGH PRESSURE...ALONG WITH THE WARM FRONT OFF THE SE U.S COAST...SHIFT OUT OVER THE OPEN ATLANTIC. FOR WED AND THU - THE UPPER TROUGH SLOWS AS IT CONTINUES TO LIFT ACROSS EASTERN CANADA WITH ZONAL FLOW SETTING UP OVER THE GULF REGION. SURFACE HIGH PRESSURE BUILDS IN OVER THE CENTRAL AND SOUTHERN PLAINS THEN TRACKS ACROSS THE LOWER EASTERN SEABOARD TO THE ATLANTIC. THE FRONT ACROSS FL HAS NOW STALLED ACROSS THE SOUTHERN HALF OF THE STATE AS IT WEAKENS. THE DEPARTING WARM FRONT AND APPROACHING COLD FRONT WILL PROVIDE AMPLE MOISTURE...MAXIMUM PWAT VALUES ALONG THE TWO BOUNDARIES ARE IN THE 1.8 TO 2.0 RANGE...FOR SHOWERS IN THE SLIGHT CHANCE TO LIKELY CATEGORY ALONG WITH SOME THUNDERSTORMS. THE COLD FRONT MOVING IN ALONG WITH THE UPPER TROUGH...BEFORE IT LIFTS AWAY...WILL RESULT IN THE HIGHEST HIGHEST COVERAGE SUN AND MON. AS THE FRONT MOVES SOUTH AND WEAKENS THROUGH MID-WEEK THE RAIN CHANCES BEGIN TO TREND DOWN FROM NORTH TO SOUTH. TEMPERATURES WILL RUN A FEW DEGREES ABOVE NORMAL ALTHOUGH THEY WILL COOL SLIGHTLY THROUGH THE PERIOD...THANKS TO CLOUD COVER AND RAINFALL. && .AVIATION... AREA OF IFR/MVFR CIGS EARLY THIS MORNING FROM KTPA TO KLAL AND NORTHWARD. FURTHER SOUTH VFR CONDITIONS PREVAIL. THESE CIG RESTRICTIONS ARE ALONG AND NORTH OF A STATIONARY FRONTAL BOUNDARY. SO...EXPECT RESTRICTIONS TO CONTINUE FOR SEVERAL MORE HOURS AND THEN LIFT WITHIN A FEW HOURS AFTER SUNRISE. GENERAL VFR CONDITIONS WILL THEN PREVAIL THROUGH THE MAJORITY OF THE DAY AND EVENING HOURS. SCT THUNDERSTORMS ARE EXPECTED BY MID AFTERNOON...BUT GENERALLY SPEAKING THE HIGHEST COVERAGE WILL BE INLAND FROM TERMINALS. && .MARINE... WIND AND SEAS REMAIN LOW THROUGH SATURDAY AWAY FROM ANY THUNDERSTORMS. A WEAK FRONTAL BOUNDARY REMAINS IN PLACE ACROSS THE NORTHEAST GULF TODAY. WINDS WILL SHIFT ONSHORE THIS AFTERNOON TO THE SOUTH OF THIS BOUNDARY...MAINLY SOUTH OF TARPON SPRINGS...AND THEN RETURN TO AN EAST/SOUTHEAST DIRECTION TONIGHT. SEA BREEZE DEVELOPMENT IS EXPECTED FOR ALL COASTAL AREAS SATURDAY AFTERNOON. && .FIRE WEATHER... RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL LEVELS THROUGH THE WEEKEND KEEPING RED FLAG CONDITIONS FROM BEING REACHED. SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST TODAY FOR MAINLY THE NATURE COAST ZONES AND INTERIOR CENTRAL AND SOUTH-CENTRAL ZONES. SHOWERS AND THUNDERSTORMS WILL AGAIN DEVELOP ALONG THE SEA BREEZE SATURDAY AFTERNOON...WITH THE GREATEST CHANCE OF A WETTING RAIN WELL INLAND FROM THE COAST. FOG POTENTIAL... AREAS OF FOG EXPECTED AFTER MIDNIGHT TONIGHT AND AGAIN SATURDAY NIGHT. THE HIGHEST POTENTIAL FOR FOG WILL EXIST GENERALLY ALONG AND NORTH OF THE I-4 CORRIDOR. && .PRELIMINARY POINT TEMPS/POPS... TPA 85 71 85 73 / 30 30 30 10 FMY 88 71 88 72 / 10 10 30 20 GIF 87 70 86 71 / 60 50 50 50 SRQ 85 71 84 71 / 10 20 20 10 BKV 86 67 86 67 / 40 30 30 30 SPG 84 73 84 75 / 20 30 20 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
433 AM EDT FRI APR 17 2015 .NEAR TERM [THROUGH TODAY]... EARLY THIS MORNING A LARGE AREA OF RAIN WAS SITUATED ALONG THE NORTH- CENTRAL GULF COAST, WITH LIGHT TO MODERATE RAIN JUST BEGINNING TO ENTER OUR WESTERN FORECAST AREA AT 07 UTC. THE LAST SEVERAL RUNS OF THE HRRR APPEAR TO HAVE THE BEST HANDLE ON THE INITIAL CONDITIONS, BUT STILL DIVERGE AFTER ABOUT 5-6 HOURS. THEREFORE, CONFIDENCE IS MUCH HIGHER FOR THE PRE-DAWN HOURS WITH LIGHT TO MODERATE RAIN EXPECTED TO CONTINUE TO SPREAD INTO OUR AREA; HIGHEST POPS WILL BE IN THE FLORIDA PANHANDLE WITH HEAVIER RAIN RATES FOCUSED TOWARD THE GULF COAST. AFTER SUNRISE THE FORECAST BECOMES MORE UNCERTAIN WITH MODELS INDICATING A VARIETY OF SOLUTIONS. ONE GENERAL TREND APPEARS TO BE THE PRIMARY AREA OF RAIN BEGINNING TO DISSIPATE LATER IN THE MORNING, FOLLOWED BY REDEVELOPMENT OF RAIN (MORE CONVECTIVE THIS TIME) IN OUR WESTERN FORECAST AREA OR JUST WEST OF OUR AREA BETWEEN 16 UTC AND 19 UTC. HOWEVER, PINPOINTING A SPECIFIC AREA WHERE RAIN IS MORE LIKELY OR RAINFALL TOTALS MAY BE HIGHER DURING THE DAYTIME IS TOUGHER DUE TO MODEL DIFFERENCES AND THE LACK OF A STRONG FORCING MECHANISM. THEREFORE, WE KEPT A "LIKELY" POP IN THE FORECAST EVERYWHERE WITH AN EMPHASIS ON STRATIFORM PRECIP IN THE MORNING (RAIN, MORE STABLE) AND A TREND TOWARD CONVECTIVE PRECIP IN THE AFTERNOON (SHOWERS AND STORMS, MORE UNSTABLE). HOWEVER, OUR GENERAL FEELING IS THAT RAIN AND STORMS WILL BECOME FOCUSED CLOSER TO THE GULF COAST WITH TIME - NEARER TO THE SURFACE FRONT. WITH VERY HIGH PRECIPITABLE WATER FOR APRIL AND WEAK FLOW BELOW 20,000 FT, ANY LOW TOPPED CONVECTION WOULD HAVE THE POTENTIAL TO PRODUCE SOME LOCALIZED HEAVY RAINFALL AND FLOODING. GIVEN THE EXPECTED ABUNDANCE OF RAIN AND CLOUD COVER TODAY, WE TRENDED TEMPERATURES TOWARD THE LOWER END OF GUIDANCE WITH HIGHS MAINLY IN THE LOW-MID 70S. .SHORT TERM [TONIGHT THROUGH SUNDAY]... THE UNUSUALLY WET PATTERN FOR APRIL WILL CONTINUE THROUGH THE WEEKEND. HOWEVER, A CHANGE IS ON THE WAY. THE UPPER LOW OVER THE CENTRAL PLAINS TONIGHT WILL LIFT TO THE NORTHEAST AND BECOME ABSORBED IN THE NORTHERN STREAM ON SUNDAY. THE AXIS OF THE BROAD UPPER TROUGH AND ASSOCIATED COLD FRONT WILL APPROACH LATE SUNDAY WITH A DRIER AIRMASS ARRIVING EARLY NEXT WEEK. UNTIL THEN, SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EVEN DURING THE OVERNIGHT HOURS. THE BEST CHANCE WILL BE ON SUNDAY WITH LIKELY TO CATEGORICAL POPS. DESPITE THE EXTENSIVE CLOUD COVER AND RAIN CHANCES, TEMPS WILL CONTINUE TO BE ABOVE SEASONAL LEVELS. .LONG TERM [SUNDAY NIGHT THROUGH FRIDAY]... THE COLD FRONT WILL PUSH THROUGH LATE MONDAY INTO EARLY TUESDAY BUT SIGNIFICANT DRYING OF THE MID-UPPER LEVELS WILL HAVE ALREADY BEGUN ON MONDAY WITH POPS ONLY IN THE CHANCE CATEGORY. TEMPERATURES WILL NOT BE THAT COOL BEHIND THE FRONT, BUT THE LOWER HUMIDITY WILL MAKE IT FEEL MORE PLEASANT THAN WHAT WE HAVE EXPERIENCED THE PAST SEVERAL DAYS. ANOTHER COLD FRONT AND NEXT DECENT CHANCE FOR RAIN WILL ARRIVE BY THE END OF THE WORK WEEK. && .AVIATION... [THROUGH 06Z SATURDAY] IFR CIGS PREVAILED AT THE TERMINALS AT TAF ISSUANCE TIME, AND IFR-LIFR CIGS SHOULD LARGELY PREVAIL INTO THE MID MORNING HOURS AS RAIN BUILDS INTO THE AREA. RAIN WILL LIKELY OCCUR AT ALL OF THE TERMINALS AT SOME POINT TODAY, BUT TIMING IS SOMEWHAT UNCERTAIN. CIGS SHOULD IMPROVE SOMEWHAT IN THE AFTERNOON, PERHAPS INTO THE MVFR RANGE, BUT IFR-LIFR CIGS ARE LIKELY ONCE AGAIN TONIGHT. && .MARINE... LIGHT SOUTHERLY WINDS ARE EXPECTED TODAY AND SATURDAY. WINDS WILL INCREASE ON SUNDAY TO AT LEAST CAUTIONARY LEVELS AS A COLD FRONT APPROACHES. WINDS AND SEAS WILL DECREASE AS THEY BECOME OFFSHORE IN THE WAKE OF THE FRONT EARLY NEXT WEEK. && .FIRE WEATHER... RED FLAG CONDITIONS ARE NOT EXPECTED WITH HIGH RH PREVAILING THROUGH THE WEEKEND. WETTING RAINS ARE LIKELY AND FUEL MOISTURE LEVELS SHOULD STAY HIGH. && .HYDROLOGY... THOUGH NOT WIDESPREAD, RECENT HEAVY RAINS IN THE FL PANHANDLE, SOUTHEAST AL, AND SOUTHWEST GA HAVE RESULTED IN SOME SHARP RISES IN LOCAL RIVER STAGES. IN PARTICULAR, THE OCHLOCKONEE RIVER AT THOMASVILLE, APALACHICOLA RIVER AT BLOUNTSTOWN, AND CHOCTAWHATCHEE RIVER AT BRUCE ARE LIKELY TO BE ABOVE LOCAL ACTION STAGE FOR THE NEXT SEVERAL DAYS, BUT REMAIN BELOW FLOOD STAGE. OVER THE NEXT SEVERAL DAYS, WE EXPECT STORM TOTAL RAINFALL AMOUNTS TO RANGE FROM ABOUT AN INCH IN NORTH FL, TO 4 INCHES IN SOUTHEAST AL AND PORTIONS OF THE FL PANHANDLE. LOCALLY HIGHER AMOUNTS EXCEEDING 6 INCHES ARE POSSIBLE. FORTUNATELY MANY OF THE RIVER STAGES IN SOUTHEAST AL AND THE FL PANHANDLE WERE BELOW NORMAL BEFORE THIS WEEK. HOWEVER, THE RAINS FROM THIS WEEK HAVE BROUGHT MANY OF THESE RIVERS TO ABOVE- NORMAL FLOWS. DEPENDING ON WHERE THE HEAVIEST RAIN SETS UP OVER THE NEXT SEVERAL DAYS, MORE OF THESE RIVERS COULD REACH LOCAL ACTION STAGE NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 77 66 84 69 81 / 70 30 40 50 70 PANAMA CITY 75 68 79 71 77 / 70 30 60 60 70 DOTHAN 72 63 79 67 77 / 70 30 60 80 70 ALBANY 73 62 79 66 78 / 60 30 40 60 70 VALDOSTA 76 64 84 67 81 / 70 30 40 30 70 CROSS CITY 79 66 84 67 83 / 60 30 40 30 60 APALACHICOLA 77 70 80 72 79 / 70 30 50 60 70 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AL...NONE. GM...NONE. && $$ NEAR TERM...LAMERS SHORT TERM...BARRY LONG TERM...BARRY AVIATION...LAMERS MARINE...BARRY FIRE WEATHER...LAMERS HYDROLOGY...FOURNIER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
721 PM EDT SAT APR 18 2015 .SYNOPSIS... A WARM FRONT WILL LIFT NORTH OF THE AREA SUNDAY MORNING...AND AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH SUNDAY AFTERNOON AND EVENING. A COLD FRONT WILL APPROACH THE AREA MONDAY AND WILL CROSS THE AREA MONDAY NIGHT. HIGH PRESSURE WILL PREVAIL TUESDAY THROUGH THURSDAY. ANOTHER COLD FRONT COULD STALL OVER OR CLOSE TO THE REGION LATE WEEK INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... THIS EVENING...THE RISK FOR ISOLATED TO SCATTERED SHOWERS WILL LINGER INTO THE EARLY EVENING HOURS WITH WEAK INSTABILITY IN PLACE. CONVECTION WILL BE DIURNAL IN NATURE AND MAINLY DRIVEN BY MESOSCALE BOUNDARY COLLISIONS. THE HIGHER RISK FOR MEASURABLE RAINFALL WILL BE PRIMARY CONFINED TO NORTHERN PORTIONS OF DORCHESTER...COLLETON AND BERKELEY COUNTIES...POSSIBLY EXTENDING AS FAR EAST AS CHARLESTON COUNTY. INCREASED POPS TO 40-50 PERCENT IN THIS AREA WITH 20-30 PERCENT CHANCE POPS ELSEWHERE WHERE CONVECTION WILL BE MORE SPARSE. ACROSS THE FAR SOUTH...OUTFLOW BOUNDARY SPARKING STRONGER CONVECTION OVER FAR SOUTHEAST GEORGIA/NORTHEAST FLORIDA BETWEEN SAINT SIMONS AND JACKSONVILLE IS MOVING STEADILY NORTH. THE BULK OF THIS ACTIVITY IS EXPECTED TO REMAIN SOUTH OF THE ALTAMAHA RIVER...HOWEVER THE ATMOSPHERE BETWEEN SAVANNAH AND DARIEN HAS YET TO BE OVERTURNED BY CONVECTION. WILL SHOW 30 PERCENT POPS ACROSS THE FAR SOUTH FOR THE NEXT FEW HOURS TO TAKE THIS TREND INTO ACCOUNT. OVERNIGHT...INCOMING GUIDANCE HAS BACKED OFF A BIT ON THE AMOUNT OF SHOWER ACTIVITY THAT WILL REDEVELOP LATE AS A DEVELOPING WARM FRONT LIFTS NORTH ACROSS THE AREA. THE LATEST RAP AND H3R ARE TRENDING WITH THE 18Z NAM IN KEEPING THE STRONGEST LOW-LEVEL JETTING/ISENTROPIC ASSENT WEST OF THE AREA THROUGH SUNRISE...WHICH SHOULD TRANSLATE TO LESS SHOWER/TSTM ACTIVITY. IT IS UNCLEAR WHETHER THIS TREND WILL PERSIST...BUT THERE IS ENOUGH EVIDENCE IN THE VARIOUS DATA SETS TO LOWER POPS SLIGHTLY FOR THE OVERNIGHT PERIOD. WILL LIMIT POPS TO THE CHANCE CATEGORY ALL AREAS AND KEEP ANY MENTION OF LIKELY POPS UNTIL AFTER SUNRISE SUNDAY. WILL CONTINUE TO MONITOR MODEL TRENDS CAREFULLY AND MAKE FURTHER ADJUSTMENTS WITH THE LATE EVENING UPDATE AFTER 00Z UPPER AIR DATA ARE RECEIVED AND ANALYZED. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... SUNDAY MORNING...A WARM FRONT WILL LIFT NORTH OF THE REGION. OVERRUNNING SHOWERS...PERHAPS ACCOMPANIED BY ISOLATED THUNDERSTORMS...WILL INITIALLY FOCUS IN THE VICINITY OF THIS BOUNDARY. THUS...MORNING POPS TAPERED FROM LIKELY NORTH/INLAND TO CHANCE SOUTH. AFTER THE BOUNDARY LIFTS NORTH...THERE MAY BE A BREAK IN PRECIPITATION COVERAGE FOR A WIDE SWATH OF THE FORECAST AREA LATE MORNING INTO EARLY AFTERNOON. THEN...ON THE EASTERN PERIPHERY OF AN UPSTREAM LONGWAVE TROUGH...A SHORTWAVE TROUGH AND AND ASSOCIATED BAND OF DYNAMIC FORCING FOR ASCENT/BAND OF ENHANCED WARM CONVEYOR BELT MOISTURE WILL EJECT EAST/NORTHEAST ACROSS THE REGION...WITHIN AN ENVIRONMENT FEATURING SOME DEGREE OF DESTABILIZATION AND 0-6 KM BULK SHEAR 35-45 KNOTS. THIS REGIME WILL SUPPORT MULTICELL SHOWERS/THUNDERSTORMS...JUSTIFYING LIKELY/CATEGORICAL POPS. WHILE THE DEGREE OF DESTABILIZATION REMAINS UNCERTAIN DUE TO CLOUD COVER...SUFFICIENT INSTABILITY SHOULD DEVELOP WITHIN THIS FORCED/SHEARED ENVIRONMENT TO PRODUCE A THREAT FOR AT LEAST POCKETS OF SEVERE WEATHER PRIMARILY PRODUCING DAMAGING WIND GUSTS SUNDAY AFTERNOON. THUS...SPC HAS UPGRADED TO A SLIGHT RISK FOR SEVERE WEATHER SUNDAY. ALSO...SINCE PWATS WILL APPROACH 2 INCHES...ENHANCED RAINFALL RATES COULD PRODUCE A LOCALIZED FLOOD THREAT IF/WHERE PERSISTENT AND/OR MULTIPLE THUNDERSTORMS OCCUR. THE SHORTWAVE WILL PUSH OFF THE COAST SUNDAY NIGHT...AND ELEVATED POPS DURING THE EVENING SHOULD DECREASE BELOW 15 PERCENT AS SOMEWHAT DRIER AIR/TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO EARLY MONDAY. THE LONGWAVE TROUGH WILL DRIVE A SURFACE COLD FRONT TOWARD THE REGION MONDAY. AHEAD OF THE FRONT...WARMING/DESTABILIZATION AND STRENGTHENING LOW/MID LEVEL WIND FIELDS WILL DEVELOP...AND THUNDERSTORMS WILL LIKELY DEVELOP OVER THE REGION AND/OR ADVANCE INTO THE REGION FROM UPSTREAM MONDAY AFTERNOON/EVENING. FORECAST UNCERTAINTY REGARDING THUNDERSTORM COVERAGE ARISES FROM DRYING ALOFT DEPICTED BY MODEL SOUNDINGS...PERHAPS LIMITING COVERAGE OF CONVECTION. THUS...CAPPED POPS AT 30-50 PERCENT...HIGHEST INLAND. DESPITE THE POTENTIAL LIMITING INFLUENCE OF THIS DRY AIR...DYNAMIC FORCING FOR ASCENT AND KINEMATIC/THERMODYNAMIC PARAMETERS SUGGEST A POTENTIAL FOR ORGANIZED SEVERE WEATHER IN THE REGION MONDAY AFTERNOON/EVENING. MONDAY NIGHT...POPS LINGER BUT GRADUALLY DECREASE AS THE COLD FRONT MOVES THROUGH. THE THREAT FOR SEVERE WEATHER SHOULD WANE AFTER DARK. TUESDAY...HIGH PRESSURE WILL PUSH A DRIER AIRMASS INTO THE REGION...ACCOMPANIED BY TEMPERATURES MAINLY 75-80F. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... A RELATIVELY DRY AND SEASONABLE PATTERN WILL BE IN PLACE TUESDAY NIGHT THROUGH THURSDAY WITH ZONAL FLOW ALOFT AND WEAK HIGH PRESSURE AT THE SURFACE. HIGHS WILL CLIMB INTO THE LOWER 80S WITH LOWS IN THE 50S/60S. A WEAKENING COLD FRONT WILL DROP INTO THE REGION THURSDAY NIGHT OR FRIDAY...POTENTIALLY PRODUCING SCATTERED SHOWERS. THIS FRONT WILL LIKELY STALL OVER OR CLOSE TO THE REGION....THEN A PROGRESSIVE UPPER SHORTWAVE WILL PUSH THROUGH THE AREA AROUND SATURDAY...BRINGING INCREASING POPS. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... KCHS...SHOWER ACTIVITY BETWEEN KRBW-KDYB SHOULD DIMINISH AND REMAIN WEST OF THE TERMINAL THROUGH 03Z. CIGS ARE EXPECTED TO LOWER SLOWLY OVERNIGHT AS A WARM FRONT APPROACHES FROM THE SOUTH. GUIDANCE AND FORECAST SOUNDINGS SUPPORT IFR CIGS DEVELOPING AFTER MIDNIGHT AND REMAINING IN PLACE THROUGH SUNRISE...THEN SLOWLY RISING AS THE FRONT LIFTS NORTH. A BAND OF RAIN/TSTMS WILL LIKELY ACCOMPANY THE FRONT...SO WILL SHOW MVFR VSBYS IN -RA FROM 15-18Z. A RISK FOR TSTMS WILL INCREASE LATE IN THE TAF PERIOD...BUT TIMING TOO UNCERTAIN THIS FAR OUT FOR A MENTION. KSAV...SHOWER ACTIVITY FROM KSSI-KJAX SHOULD REMAIN WELL TO THE SOUTH. WILL WATCH FOR POSSIBLE REDEVELOPMENT ALONG MESOSCALE BOUNDARY COLLISIONS...BUT ATTM NO IMPACTS ARE EXPECTED AT KSAV. A WARM FRONT IS EXPECTED TO DEVELOP AND LIFT NORTH OVERNIGHT/EARLY SUNDAY. BEST LIFT/RISK FOR LOWER CIGS WILL REMAIN NORTH OF THE SAVANNAH RIVER...BUT ENOUGH EVIDENCE IS THERE TO JUSTIFY A PERIOD OF LOW-END MVFR CIGS FROM ROUGHLY 07-12Z WITH VFR THEREAFTER. COULD SEE A BRIEF TRANSITION PERIOD 04-07Z...BUT TIMING IS UNCERTAIN. WHILE THE RISK FOR IFR CIGS IS THERE...BETTER PROBABILITIES WILL REMAIN NORTH OF THE TERMINAL. A RISK FOR TSTMS WILL INCREASE LATE IN THE TAF PERIOD...BUT TIMING TOO UNCERTAIN THIS FAR OUT FOR A MENTION. EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY SUNDAY AFTERNOON INTO SUNDAY NIGHT...ESPECIALLY WITHIN SHOWERS/THUNDERSTORMS. OUTSIDE SCATTERED SHOWERS/THUNDERSTORMS AS A COLD FRONT APPROACHES THEN MOVES THROUGH THE REGION...MAINLY VFR MONDAY AND MONDAY NIGHT...THEN VFR THROUGH MID WEEK. && .MARINE... TONIGHT...THE SETUP WILL CONTINUE TO SUPPORT QUIET CONDITIONS ACROSS THE LOCAL WATERS. A SUBTLE WARM FRONT WILL LIFT NORTHWARD AND A PREVAILING EAST-SOUTHEAST TO SOUTHEAST FLOW WILL GRADUALLY BECOME MORE SOUTHERLY LATE. WINDS WILL BE LESS THAN 10 KT WITH SEAS 2-3 FT. A WARM FRONT WILL LIFT NORTH OF THE WATERS SUNDAY...FOLLOWED BY INTENSIFYING SOUTH/SOUTHWEST FLOW. THE PROBABILITY FOR SMALL CRAFT ADVISORY CONDITIONS WILL INCREASE ESPECIALLY SUNDAY NIGHT UNTIL A COLD FRONT ARRIVES MONDAY NIGHT...ESPECIALLY CLOSE TO THE COAST INCLUDING CHARLESTON HARBOR. THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE WATERS SUNDAY AFTERNOON/EVENING AND AGAIN MONDAY AFTERNOON/EVENING. AFTER THE COLD FRONT PASSES...A QUIETER PATTERN WILL DEVELOP TUESDAY UNTIL LATE WEEK AS HIGH PRESSURE PREVAILS. && .TIDES/COASTAL FLOODING... HAVE AGAIN OPTED AGAINST A COASTAL FLOOD ADVISORY. WINDS ARE ONSHORE WITH A SEABREEZE SETTING UP...BUT ARE STILL WEAK. ASTRONOMICAL INFLUENCES ARE LIKELY AT THEIR PEAK BUT CURRENT TIDAL DEPARTURES ARE ONLY BETWEEN 0.2-0.3 FT...AND SHOULD DECREASE FURTHER AS HIGH TIDE APPROACHES. THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR SUNDAY AND MONDAY EVENINGS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
637 AM EDT FRI APR 17 2015 .SYNOPSIS... A LOW-LEVEL WEDGE WILL REMAIN IN PLACE THROUGH EARLY TODAY AND BEGIN GRADUALLY DISSIPATING THIS AFTERNOON. AN UPPER DISTURBANCE WILL CONTRIBUTE TO SOME SHOWER ACTIVITY TODAY. AN UPPER RIDGE WILL PROVIDE FAIR WEATHER SATURDAY. EXPECT INCREASING MOISTURE AND PRECIPITATION CHANCES WITH SHOWERS AND POSSIBLY THUNDERSTORMS SUNDAY AND SUNDAY NIGHT. HEAVY RAIN MAY OCCUR. THE BULK OF THE MOISTURE WILL SHIFT TO OUR EAST MONDAY AHEAD OF A WEAK COLD FRONT THAT IS EXPECTED TO MOVE THROUGH THE AREA MONDAY AFTERNOON. FAIR WEATHER IF FORECAST BEHIND THE FRONT LATE MONDAY THROUGH WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... THE MODELS INDICATE DIMINISHED ISENTROPIC LIFT TODAY WITH THE WEDGE PATTERN DISSIPATING BY THE MIDDLE OF THE DAY. THERE WILL BE LIFT ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH. THE MODELS SHOW THE GREATER FORCING ASSOCIATED WITH THE UPPER FEATURE AFFECTING THE SOUTH PART TODAY. THE MODELS HAVE TRENDED WITH INCREASING POPS. THE ARW AND SPC WRF DISPLAY SCATTERED COVERAGE OF SHOWERS. THE HRRR IS TRENDING WITH GREATER COVERAGE APPROACHING THE CSRA BY EARLY AFTERNOON. INSTABILITY ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH PLUS THE BREAK DOWN OF THE SURFACE WEDGE PATTERN SUGGESTS POSSIBLE THUNDERSTORMS THIS AFTERNOON. BELIEVE CLOUDINESS WILL HELP KEEP INSTABILITY WEAK. THE MODELS ALSO INDICATE WEAK SHEAR. BELIEVE ANY THUNDERSTORMS THIS AFTERNOON WILL BE ISOLATED. THERE IS LOW CONFIDENCE WITH THE HIGH TEMPERATURE FORECAST TODAY BECAUSE OF TIMING UNCERTAINTY WITH THE DISSIPATING WEDGE PATTERN. THE MODELS TYPICALLY DIMINISH THE WEDGE TOO QUICKLY SUPPORTING THE COOLER GUIDANCE. THE MODELS DISPLAYED LINGERING HIGH LOW-LEVEL MOISTURE TONIGHT. THE GFS HAD MORE MID-LEVEL SHORTWAVE TROUGHING AFFECTING MAINLY THE SOUTH PART OF THE FORECAST AREA TONIGHT. THE GUIDANCE CONSENSUS SUPPORTED CHANCE POPS MAINLY IN THE SOUTH PART. THERE MAY BE AREAS OF FOG BECAUSE OF THE HIGH LOW-LEVEL MOISTURE WITH LIGHT WIND PLUS THE NAM FORECAST OF MID-LEVEL DRYING. THE GUIDANCE TEMPERATURES WERE CLOSE. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... LATEST MODEL RUNS TRENDING SLOWER WITH PROGRESSION OF SYSTEMS AFFECTING OUR REGION. UPPER LOW WILL CONTINUE TO MEANDER OVER THE W CONUS...FOUR CORNERS/FRONT RANGE REGION...THROUGH SATURDAY WITH THE MAIN UPPER FLOW REMAINING WELL TO OUR NORTH ACROSS CANADA. LATEST MODEL RUNS INDICATE UPPER SHORT WAVE TO TRAVERSE OUR REGION FRIDAY...WITH UPPER RIDGE AXIS NOT SHIFTING EAST INTO OUR REGION UNTIL SATURDAY. LOW LEVEL WEDGE WILL TRY TO GRADUALLY ERODE FRIDAY. MODELS INDICATE WEDGE ERODING DURING THE MORNING...BUT MODELS TEND TO ERODE WEDGES TOO QUICKLY. HOWEVER...WEDGE MAY INDEED ERODE DURING THE AFTERNOON. WITH UPPER SHORT WAVE...DIURNAL HEATING...AND APPEARANCE OF SUFFICIENT ATMOSPHERIC MOISTURE OVER THE REGION...BUMPED UP POPS FOR FRIDAY. SATURDAY NOW APPEARS WILL BE GENERALLY FAIR...WITH UPPER RIDGE AXIS AND DRIER MID LEVEL AIR OVER THE REGION...THOUGH DIURNAL HEATING AND SEA BREEZE COULD LEAD TO SOME AFTERNOON SHOWERS AND A POSSIBLE THUNDERSTORM MAINLY SOUTH. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRONT RANGE UPPER LOW IS PROGGED TO GRADUALLY OPEN AND SHIFT EAST INTO THE CENTRAL CONUS SAT NT AND SUN IN RESPONSE TO NORTHERN STREAM UPPER ENERGY DIGGING SE FROM W CANADA/PAC NW INTO THE NORTHERN ROCKIES/N PLAINS. UPPER HIGH AXIS WILL SHIFT TO OUR EAST OFFSHORE SAT NT. AHEAD OF THE UPPER LOW...SOUTHERN STREAM UPPER IMPULSES WILL MOVE NE FROM NORTHERN MEXICO INTO THE LOWER MISSISSIPPI VALLEY/GULF COAST REGION. THIS WILL LEAD TO SURFACE LOW DEVELOPING OVER THE LOWER MISSISSIPPI VALLEY AND TRACKING NE INTO THE MIDWEST/GREAT LAKES REGION...WHILE SURFACE HIGH SHIFTS SE INTO NEW ENGLAND. AN INCREASING SE LOW LEVEL FLOW SATURDAY...BECOMING SW SUNDAY...WILL BRING INCREASING MOISTURE BACK INTO OUR REGION. WITH MODELS SLOWING PROGRESSIONS OF SYSTEMS DOWN SOME...IT NOW APPEARS AXIS OF HIGH MOISTURE AND ASSOCIATED SHOWERS AND POSSIBLE THUNDERSTORMS WILL PROVIDE THE BEST THREAT OF PRECIPITATION AND POSSIBLY HEAVY RAIN...SUNDAY AFTERNOON THRU SUN NT TIME FRAME. THERE ARE INDICATIONS THAT WITH MUCH HIGHER THAN NORMAL PRECIPITABLE WATER VALUES FOR THIS TIME OF YEAR...THAT HEAVY RAIN WILL BE POSSIBLE. MODELS SHIFT THE AXIS OF HIGHEST MOISTURE TO OUR EAST BY MONDAY AHEAD OF A COLD FRONT PASSING THROUGH MONDAY AFTERNOON. HOWEVER...SOME SHOWER AND POSSIBLE THUNDERSTORM ACTIVITY WILL BE POSSIBLE WITH THE FROPA. DRIER AIR AND HIGH PRESSURE BEHIND THE FRONT APPEARS WILL PROVIDE FAIR WEATHER FOR OUR REGION MONDAY NIGHT THROUGH MID WEEK. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... COOL WEDGE REMAINS IN PLACE WITH MAINLY DRIZZLE OVER THE AREA EARLY THIS MORNING. IFR CIGS START THE FORECAST. MOST OF THE GFS AND NAM MOS PLUS SREF GUIDANCE SHOW AN IMPROVING TREND INTO THE MVFR CATEGORY THIS AFTERNOON. THE NAM SURFACE-BASED LI PATTERN SUGGESTED THE WEDGE PATTERN WILL DISSIPATE BY THE MIDDLE OF THE DAY. CONFIDENCE IS NOT HIGH WITH THE TIMING. THE MODELS TYPICALLY DIMINISH WEDGES TOO QUICKLY. THERE WILL BE LIFT ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH TODAY. THE MODELS INDICATED FORCING ASSOCIATED WITH THE UPPER FEATURE WILL BE STRONGER IN THE SOUTH. SHOWERS AND ASSOCIATED RESTRICTIONS MAY BE MORE WIDESPREAD AT AGS AND DNL AND WE FORECASTED MORE PESSIMISTIC CONDITIONS AT THESE TERMINALS THAN FARTHER NORTH. THE SPC WRF AND ARW MODELS DISPLAY SCATTERED SHOWER COVERAGE. THE HRRR IS TRENDING WITH GREATER COVERAGE APPROACHING THE CSRA BY EARLY AFTERNOON. INSTABILITY ASSOCIATED WITH THE MID-LEVEL SHORTWAVE TROUGH PLUS THE BREAK DOWN OF THE SURFACE WEDGE PATTERN SUGGESTS POSSIBLE THUNDERSTORMS THIS AFTERNOON. BELIEVE CLOUDINESS WILL HELP KEEP INSTABILITY WEAK. BELIEVE ANY THUNDERSTORMS THIS AFTERNOON WILL BE ISOLATED WITH THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. THE MODELS DISPLAYED LINGERING HIGH LOW-LEVEL MOISTURE TONIGHT. THE GFS HAD MORE MID-LEVEL SHORTWAVE TROUGHING AFFECTING MAINLY THE SOUTH PART OF THE FORECAST AREA TONIGHT SUPPORTING A CONTINUED SHOWER CHANCE. THERE MAY BE AREAS OF FOG BECAUSE OF THE HIGH LOW- LEVEL MOISTURE WITH LIGHT WIND PLUS THE NAM FORECAST OF MID-LEVEL DRYING. EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR IFR CONDITIONS MAY OCCUR SATURDAY MORNING BECAUSE OF RESIDUAL LOW-LEVEL MOISTURE. A WARM FRONT WILL LIKELY BRING WIDESPREAD MVFR OR IFR CONDITIONS SATURDAY NIGHT THROUGH EARLY MONDAY MORNING. && .HYDROLOGY... RAINFALL ACROSS THE AREA THE PAST COUPLE OF DAYS COMBINED WITH RELEASES FROM PARR RESERVOIR AND LAKE MURRAY WILL PRODUCES RISES ALONG THE CONGAREE RIVER. THE RIVER IS FORECAST TO CREST JUST BELOW THE ADVISORY STAGE OF 10 FEET AT COLUMBIA TODAY. A CREST NEAR FLOOD STAGE OF 115 FEET AT CAROLINA EASTMAN MAY OCCUR TODAY. THIS WILL PRODUCE SOME MINOR FLOODING ALONG THE THREE RIVERS GREENWAY AND ALSO DOWNSTREAM FROM COLUMBIA OVER THE WEEKEND AT THE CONGAREE NATIONAL PARK. ALL OTHER FORECAST POINTS ACROSS THE MIDLANDS AND CSRA ARE EXPECTED TO REMAIN BELOW FLOOD STAGE THROUGH SATURDAY...BUT POSSIBLE HEAVY RAIN IN THE HEADWATERS SUNDAY COULD LEAD TO RIVER FLOODING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
215 AM EDT FRI APR 17 2015 .UPDATE... AREA OF RAIN CONTINUES TO BLOSSOM ACROSS THE CWFA THIS EVENING. LATEST RUNS OF THE HRRR SHOW THE RAINFALL SHOULD TAPER OFF AFTER 06Z. UPDATED THE POPS EARLIER THIS EVENING...AND JUST UPDATED THEM AGAIN TO CATEGORICAL OVER A GOOD PORTION OF THE CWFA. HAVE ALSO TWEAKED THE HOURLY TEMPS AND DEWPOINTS. CHANCES OF CONVECTION REMAIN SMALL...BUT SHOULD CONTINUE THROUGH MIDNIGHT. && .PREV DISCUSSION... /ISSUED 348 PM EDT THU APR 16 2015/ SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... A WET/UNSETTLED PATTERN LOOKS TO PERSIST THROUGH THE SHORT TERM. THE WEDGE PERSISTS THIS AFTERNOON AND SHOULD CONTINUE INTO THE OVERNIGHT WITH THE WEDGE GRADUALLY BREAKING DOWN FRIDAY. SHOWERS AND A FEW THUNDERSTORMS WERE INCREASING TO THE WEST AND SHOULD CONTINUE TO MOVE NORTHEAST...WITH HIGH RESOLUTION MODELS SHOWING WIDESPREAD RAINFALL FOR MUCH OF THE NIGHT. THIS SHOULD CONTINUE INTO FRIDAY MORNING. MOST UNSTABLE AIR WILL BE AROUND THE EDGE OF THE COOLER AIR AND HAVE INCLUDED THUNDER FOR TONIGHT ALONG THE NORTHERN AND WESTERN ZONES. SOME GENERAL INCREASE IN INSTABILITY FOR FRIDAY AND HAVE MENTIONED THUNDER ACROSS THE AREA. MODELS HINT AT A BREAK UNTIL NEXT WAVE APPROACHES THE FORECAST AREA ON SATURDAY...SO HAVE REDUCED THE POPS FOR FRIDAY NIGHT. FLOODING ISSUES MAY BE HIT AND MISS AND HAVE NOT ISSUED ANY FLOOD WATCH. SOME LOCAL RIVER AND STREET FLOODING WILL CONTINUE TO BE POSSIBLE. TEMPERATURES THIS AFTERNOON ARE RUNNING A BIT LOWER THAN FORECAST AND MAY HOLD NEAR STEADY OVERNIGHT WITH THE EASTERLY WINDS. SOME WARMING EXPECTED ON FRIDAY. 41 LONG TERM /SATURDAY THROUGH THURSDAY/... NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. MODELS STILL A BIT SLOWER WITH INCREASING DEEP MOISTURE ON SATURDAY WITH THE BEST MOISTURE NOT BEGINNING TO MOVE IN UNTIL 00Z SUN. BEST OPPORTUNITY FOR RAINFALL CONTINUES TO BE SUN/SUN NIGHT WITH HIGH SHOWERS CHANCES AND A CHANCE OF THUNDERSTORMS ACROSS THE AREA. PWS ACROSS THE AREA INCREASE INTO THE 1.5 TO 1.75 INCH RANGE BEGINNING 00Z SUN THROUGH 00Z MON. THIS WILL BRING PERIODS OF MODERATE TO HEAVY RAIN THIS WEEKEND ACROSS THE ENTIRE CWA. THE POTENTIAL FOR LOCALIZED FLOODING WILL NEED TO BE CLOSELY MONITORED. A COLD FRONT MOVES ACROSS THE AREA MONDAY/MONDAY NIGHT AND RAIN CHANCES WILL END MONDAY NIGHT. TUESDAY AND WEDNESDAY ARE EXPECTED TO BE DRY AS THE WESTERLY UPPER FLOW DRIES OUT. A SHORT WAVE IN THE UPPER FLOW THU MORNING WILL NEED TO BE WATCHED FOR POSSIBLE LIGHT PRECIP CHANCES. HAVE INTRODUCE A SLIGHT CHANCE OF PRECIP FOR NOW. TEMPERATURES ARE GENERALLY EXPECTED TO BE NEAR TO ABOVE NORMAL. 01 PREVIOUS LONG TERM DISCUSSION /FRIDAY NIGHT THROUGH WEDNESDAY/ /ISSUED AT 505 AM EDT THU APR 16 2015/...WE LOOK TO BE IN BETWEEN SYSTEMS FRIDAY NIGHT AS WEAK SURFACE HIGH PRESSURE AND A SHORT WAVE RIDGE ALOFT PREDOMINATE. THIS WILL TRANSLATE TO ONLY LOW POPS DURING THE EVENING FOR CENTRAL AND PARTS OF NORTH GEORGIA. FORECAST LOW TEMPERATURES RUNNING 8-10 DEGREES ABOVE NORMAL. MODELS NOW SLOWER WITH INCREASING DEEP MOISTURE ON SATURDAY IN THE SW UPPER FLOW AND INCREASING SOUTHERLY LOW LEVEL FLOW. BEST RAIN CHANCES NOW LOOK TO BE LATE SATURDAY AND LIGHT. DEEPEST MOISTURE INCREASES SATURDAY NIGHT AND CONTINUES INTO SUNDAY NIGHT WITH HIGH SHOWERS CHANCES AND A CHANCE OF THUNDERSTORMS ACROSS THE AREA. A COLD FRONT MOVES ACROSS THE AREA MONDAY/MONDAY NIGHT AND RAIN CHANCES WILL END MONDAY NIGHT. TUESDAY AND WEDNESDAY ARE EXPECTED TO BE DRY AS THE WESTERLY UPPER FLOW DRIES OUT. A SHORT WAVE IN THE UPPER FLOW LATE WEDNESDAY WILL NEED TO BE WATCHED FOR POSSIBLE LIGHT PRECIP CHANCES. UPDATED... AT THIS TIME...A PERIOD OF MODERATE TO HEAVY RAIN WILL BE POSSIBLE THIS WEEKEND...MOST SO FOR NORTHEAST GEORGIA. THE POTENTIAL FOR LOCALIZED FLOODING WILL NEED TO BE CLOSELY MONITORED. TEMPERATURES ARE GENERALLY EXPECTED TO BE NEAR TO ABOVE NORMAL. BDL && .AVIATION... 06Z UPDATE... IFR OR LOWER CONDITIONS ARE EXPECTED TO PREDOMINATE ACROSS THE AREA THROUGH 14Z...WITH CONDITIONS IMPROVING TO MVFR BY 16Z-18Z MOST AREAS. MAY SEE SOME BRIEF...SCATTERED PERIODS OF VFR CONDITIONS BETWEEN 20Z AND 02Z. SOME LIGHT RAIN OR SHOWERS ARE POSSIBLE THROUGH 16Z...WITH MAINLY SHOWERS SCATTERED ACROSS THE AREA...AND A FEW ISOLATED THUNDERSTORMS...16Z-02Z. EAST WINDS 4-8KT THROUGH 16Z WITH WINDS BECOMING SOMEWHAT VARIABLE IN DIRECTION 16Z-20Z. WINDS ARE EXPECTED TO BE GENERALLY WESTERLY AFTER 20Z...BUT WILL BE LIGHT AT 5KTS OR LESS. //ATL CONFIDENCE...06Z UPDATE... MEDIUM CONFIDENCE ALL ELEMENTS. 20 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 54 72 58 81 / 90 40 20 40 ATLANTA 53 73 61 77 / 100 50 20 50 BLAIRSVILLE 52 71 54 75 / 100 40 20 40 CARTERSVILLE 53 73 57 79 / 100 50 20 50 COLUMBUS 57 73 61 79 / 100 60 20 50 GAINESVILLE 53 71 58 77 / 100 40 20 40 MACON 57 72 58 79 / 100 60 20 40 ROME 54 73 57 78 / 60 40 20 50 PEACHTREE CITY 53 73 57 77 / 100 50 20 50 VIDALIA 58 73 62 82 / 80 50 30 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1220 PM CDT FRI APR 17 2015 .UPDATE... ISSUED AT 1050 AM CDT FRI APR 17 2015 WEAK RIDGING OVER THE REGION KEEPING MILD WEATHER IN PLACE. QUICK MORNING WARM UP UNDER A MOSTLY SUNNY SKY AND TEMPS ON TRACK TO HEAD INTO THE UPPER 70S. ALTHOUGH CUMULUS CLOUDS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON...COVERAGE SHOULD BE LIGHTER IN THE NORTH THAN THE SOUTHERN TIER OF THE STATE...AND SHOULD NOT INTERFERE TOO MUCH WITH THE DIURNAL TREND UNDER SUCH LIGHT WINDS. FORECAST DOING WELL...HAVE ONLY MADE SOME MINOR ADJUSTMENTS. MAJOR UPDATES ARE NOT ANTICIPATED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CDT FRI APR 17 2015 A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I- 57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 331 AM CDT FRI APR 17 2015 DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING ANOTHER MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH MILDEST READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED. LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT. THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74 SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S WITH SOME UPPER 60S NORTH OF I-74. A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID 40S, WITH COOLEST READINGS FROM I-74 NORTH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1216 PM CDT FRI APR 17 2015 DIURNAL CU ACROSS THE REGION DEVELOPING AND VERY FEW OVER CMI...BUT MORE BKN TO THE SOUTH FOR SPI AND DEC POTENTIALLY THROUGH THE AFTERNOON. STILL VERY LIGHT AND VARIABLE WINDS EXPECTED ACROSS THE REGION...WITH MAINLY WESTERLY FLOW ALOFT. STILL PLENTY OF LLVL MOISTURE IN THE BOUNDARY LAYER TO LEND TO A SLIGHT REDUCTION OF VISIBILITY OVERNIGHT AND IN THE EARLY MORNING HOURS. HAVE CONTINUED THE TREND TO MAINLY MVFR VIS...BUT WILL HAVE TO KEEP A CLOSE EYE ON THE XOVER TEMPS THIS AFTERNOON. NOT MUCH IN THE WAY OF MIXING IS ANTICIPATED AGAIN WITH THE LIGHT FLOW...BUT SINCE WESTERN TERMINALS WERE RELATIVELY LIGHT VIS DROPS THIS MORNING...EXPECT SOME OF THAT WILL TRANSLATE EASTWARD. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HJS SHORT TERM...07 LONG TERM...07 AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1057 AM CDT FRI APR 17 2015 .UPDATE... ISSUED AT 1050 AM CDT FRI APR 17 2015 WEAK RIDGING OVER THE REGION KEEPING MILD WEATHER IN PLACE. QUICK MORNING WARM UP UNDER A MOSTLY SUNNY SKY AND TEMPS ON TRACK TO HEAD INTO THE UPPER 70S. ALTHOUGH CUMULUS CLOUDS ARE EXPECTED TO DEVELOP LATER THIS AFTERNOON...COVERAGE SHOULD BE LIGHTER IN THE NORTH THAN THE SOUTHERN TIER OF THE STATE...AND SHOULD NOT INTERFERE TOO MUCH WITH THE DIURNAL TREND UNDER SUCH LIGHT WINDS. FORECAST DOING WELL...HAVE ONLY MADE SOME MINOR ADJUSTMENTS. MAJOR UPDATES ARE NOT ANTICIPATED. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CDT FRI APR 17 2015 A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I- 57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 331 AM CDT FRI APR 17 2015 DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING ANOTHER MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH MILDEST READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED. LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT. THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74 SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S WITH SOME UPPER 60S NORTH OF I-74. A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID 40S, WITH COOLEST READINGS FROM I-74 NORTH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 639 AM CDT FRI APR 17 2015 DENSE FOG MOVED IN FROM THE EAST LAST NIGHT AND IS NOW COVERING CMI ONLY. DEC AND BMI HAVE SOME LIGHT FOG AND COULD SEE LOWER CONDITIONS FOR A COUPLE OF HOURS THIS MORNING. SO WILL HAVE TEMPO GROUP FOR CMI, DEC, AND BMI. SPI AND PIA SHOULD NOT SEE ANY FOG, GIVEN THE TEMP/DEWPOINT SPREAD, ESPECIALLY AT PIA. BESIDES THE FOG, HIGH CIRRUS WILL SPREAD OVER ALL TAF SITES THIS MORNING AND WILL CONTINUE THROUGH THE AFTERNOON AND INTO TONIGHT. MORE FOG IS POSSIBLE AGAIN TONIGHT, SO HAVE ADDED 3-4SM AT ALL SITES AROUND MIDNIGHT. WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE PERIOD AS HIGH PRESSURE WILL DOMINATE THE AREA NEXT 24HRS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HJS SHORT TERM...07 LONG TERM...07 AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
639 AM CDT FRI APR 17 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CDT FRI APR 17 2015 A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I- 57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 331 AM CDT FRI APR 17 2015 DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING ANOTHER MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH MILDEST READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED. LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT. THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74 SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S WITH SOME UPPER 60S NORTH OF I-74. A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID 40S, WITH COOLEST READINGS FROM I-74 NORTH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 639 AM CDT FRI APR 17 2015 DENSE FOG MOVED IN FROM THE EAST LAST NIGHT AND IS NOW COVERING CMI ONLY. DEC AND BMI HAVE SOME LIGHT FOG AND COULD SEE LOWER CONDITIONS FOR A COUPLE OF HOURS THIS MORNING. SO WILL HAVE TEMPO GROUP FOR CMI, DEC, AND BMI. SPI AND PIA SHOULD NOT SEE ANY FOG, GIVEN THE TEMP/DEWPOINT SPREAD, ESPECIALLY AT PIA. BESIDES THE FOG, HIGH CIRRUS WILL SPREAD OVER ALL TAF SITES THIS MORNING AND WILL CONTINUE THROUGH THE AFTERNOON AND INTO TONIGHT. MORE FOG IS POSSIBLE AGAIN TONIGHT, SO HAVE ADDED 3-4SM AT ALL SITES AROUND MIDNIGHT. WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE PERIOD AS HIGH PRESSURE WILL DOMINATE THE AREA NEXT 24HRS. && .ILX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR ILZ044>046- 054>057-061>063-066>068-071>073. && $$ SHORT TERM...07 LONG TERM...07 AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
331 AM CDT FRI APR 17 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CDT FRI APR 17 2015 A DENSE FOG ADVISORY ISSUED AROUND 2 AM FOR EASTERN IL WILL BE ALLOWED TO CONTINUE THROUGH 9 AM CDT. THE PAST HOUR OR TWO THE DENSE FOG WITH VSBYS 1/4 MILE OR LESS HAS BEEN CONFINED TO AREAS EAST OF I- 57 AND COULD EXPAND FURTHER WEST OF I-57 WITH AREAS OF FOG AND PATCHY DENSE FOG AS FAR WEST AS I-55 PER HRRR MODEL UNTIL 9 AM. ONCE THE FOG LIFTS LATER THIS MORNING A NICE MILD SPRING DAY IS SHAPING UP ACROSS CENTRAL AND SOUTHEAST IL WITH WEAK HIGH PRESSURE OVER IN AND SOME UPPER LEVEL RIDGING INTO IL GIVING MOSTLY SUNNY SKIES AND LIGHT WINDS AND MILD HIGHS IN THE MID TO UPPER 70S. && .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 331 AM CDT FRI APR 17 2015 DRY CONDITIONS STILL EXPECTED TO CONTINUE ACROSS CENTRAL AND SOUTHEAST IL THROUGH AT LEAST SAT MORNING WITH JUST ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE DURING MID/LATE SAT AFTERNOON ALONG AND SW OF A GALESBURG TO LINCOLN TO LAWRENCEVILLE LINE. UPPER LEVEL RIDGE INTO THE OHIO RIVER VALLEY AND IL YET ON SATURDAY TO BRING A NOTHER MILD SPRING DAY IN THE MID TO UPPER 70S SATURDAY, WITH MILDEST READINGS NEAR THE IN BORDER WHERE MORE SUNSHINE EXPECTED. LARGE CUTOFF UPPER LEVEL LOW OVER COLORADO TONIGHT AND SATURDAY GETS ABSORBED BY NORTHERN STREAM CUTOFF LOW NORTH OF ND/MN SUNDAY AND MONDAY. WARM AIR ADVECTION SHOWERS AND SCATTERED THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL AND SOUTHEAST IL DURING SATURDAY NIGHT ESPECIALLY AFTER MIDNIGHT AND CONTINUE SUNDAY. FAIRLY STRONG SURFACE LOW PRESSURE EJECTS NE FROM OK PANHANDLE TO NEAR CENTRAL IL BY SUNSET SUNDAY AND SWEEPS A COLD FRONT EAST THROUGH IL SUNDAY NIGHT. THIS TO LIKELY BRING MORE SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT AND SPC HAS MARGINAL RISK OF SEVERE STORMS SW OF I-74 SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING WITH SLIGHT RISK SW OF A PITTSFIELD TO EFFINGHAM TO LAWRENCEVILLE LINE FOR LARGE HAIL AND DAMAGING WIND GUSTS POSSIBLE. HIGHS SUNDAY MOSTLY IN THE LOWER 70S WITH SOME UPPER 60S NORTH OF I-74. A LARGE UPPER LEVEL TROF THEN DOMINATES THE MIDWEST MONDAY-THURSDAY AS STRONG CUTOFF LOW MOVES SLOWLY EAST ACROSS THE NORTHERN GREAT LAKES REGION. SHOWERS SHOULD DIMINISH TO WIDELY SCATTERED SHOWERS OVER CENTRAL IL ON MONDAY WITH BEST CHANCES OF SHOWERS OVER IN AND NORTHERN IL. COOLER HIGHS OF 60-65F MONDAY WITH MILDEST READINGS BY LAWRENCEVILLE. HAVE DRY AND COOL CONDITIONS MONDAY NIGHT THROUGH TUE NIGHT. THEN SMALL CHANCES OF SHOWERS WED/THU WITH A WEATHER SYSTEM APPROACHING FROM THE SW WITH GFS MODEL TRENDING MUCH WETTER DURING THIS TIME FRAME WHILE ECMWF MODEL IS KEEPING IL DRY. COOL HIGHS IN THE UPPER 50S/LOWER 60S TUE-WED WITH LOWS IN THE UPPER 30S TO MID 40S, WITH COOLEST READINGS FROM I-74 NORTH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1157 PM CDT THU APR 16 2015 AREAS MVFR CONDITIONS WITH LOCAL IFR IN FOG FROM AROUND KCMI-K1H2 EASTWARD THIS EVENING...WITH VFR TO THE WEST AS A SURFACE HIGH PRESSURE CENTER REMAINS NEAR THE NORTHEAST CORNER OF THE STATE. FOG WILL SPREAD WESTWARD TO AROUND KBMI-KSPI EASTWARD WHERE GREATEST AMOUNTS OF LOW LEVEL MOISTURE REMAIN ALONG WITH LIGHT WINDS AND LACK OF HIGHER LEVEL CLOUD COVER. WITH DAYTIME HEATING...FOG SHOULD DISSIPATE 13Z-15Z WITH SCATTERED CUMULUS DEVELOPMENT ABOVE MVFR THRESHOLDS. LIGHT SSE WINDS 5-8 KTS DEVELOPING IN THE DAYTIME PERIOD...CONTINUING INTO EVENING. && .ILX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR ILZ044>046- 054>057-061>063-066>068-071>073. && $$ SHORT TERM...07 LONG TERM...07 AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1157 PM CDT THU APR 16 2015 .UPDATE... ISSUED AT 901 PM CDT THU APR 16 2015 HIGH PRESSURE OVER THE REGION WILL RESULT IN MINIMAL CLOUD COVER OVERNIGHT. HOWEVER...FAIRLY HIGH DEWPOINTS MAINLY IN THE 50S WILL LIKELY PRODUCE AREAS OF FOG AS THE CLEAR SKIES ALLOW GOOD RADIATIONAL COOLING ALONG WITH LIGHT WINDS ASSOCIATED WITH THE HIGH. ALREADY HAVE AREAS OF FOG IN FORECAST FROM I-57 CORRIDOR EASTWARD...WHICH IS IN GOOD AGREEMENT WITH THE LATEST HRRR MODEL. MAIN UPDATE POSSIBILITY WOULD BE EXTENT OF FOG WESTWARD...AS WELL AS IF ANY DENSE AREAS DEVELOP. FOR NOW...CURRENT FORECAST LOOKS IN GOOD SHAPE WITH ONLY UPDATES FOR MINOR TEMPERATURE/CLOUD TRENDS SO FAR. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 310 PM CDT THU APR 16 2015 HIGH PRESSURE RIDGE SLIDING OFF TO THE EAST AS QUASI ZONAL FLOW TRANSITIONING TO A SLIGHTLY SOUTHWESTERLY FLOW WITH A DEEP LOW DIGGING IN AT H5 OVER THE DESERT SW. REMNANT MOISTURE AFFILIATED WITH WAVE PULLING OFF TO THE EAST STILL IMPACTING THE EASTERN EDGES OF THE STATE THIS AFTERNOON WITH A MORE PERSISTENT CLOUD COVER. LIGHT AND VARIABLE WINDS TONIGHT WITH CLEARING SKIES JUST BEFORE SUNSET SHOULD SET UP A GOOD ENVIRONMENT FOR SOME RADIATIONAL COOLING. WITH RELATIVELY HIGHER RH IN THE BOUNDARY LAYER TODAY NOT GETTING MUCH OF A CHANCE FOR MIXING...HAVE PUT FOG IN FOR THE OVERNIGHT IN THE EAST AND SOUTHEAST. CONCERN THAT IT MAY BE MORE WIDESPREAD THAN THE CURRENT PLACEMENT WITH THE DWPTS IN THE WEST STILL NEAR 50. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 310 PM CDT THU APR 16 2015 FRIDAY WILL FEATURE UPPER LEVEL RIDGING AND WARMING ACROSS ILLINOIS, AS A CUT-OFF LOW IN THE PLAINS SLOWLY DRIFTS FROM THE FOUR CORNERS INTO COLORADO. HIGHS WILL REACH INTO THE UPPER 70S IN MANY AREAS FRIDAY AFTERNOON, UNDER A LIGHT SOUTHEAST WIND. RAIN AHEAD OF THE CUT-OFF LOW WILL ADVANCE EASTWARD ACROSS THE PLAINS ON FRIDAY, EXPANDING ACROSS IOWA AND MISSOURI FRIDAY NIGHT AND SATURDAY. CENTRAL ILLINOIS SHOULD REMAIN DRY THROUGH FRIDAY NIGHT, WITH A FEW SHOWERS POSSIBLY AFFECTING AREAS SW OF SPI TO EFFINGHAM ON SATURDAY. INCREASING CLOUDS ON SATURDAY WILL WORK TO KEEP HIGHS A FEW DEGREES BELOW POTENTIAL HIGHS, BUT WE STILL EXPECT MID 70S TO PREVAIL FOR HIGHS. THE LOW WILL BECOME AN OPEN WAVE SATURDAY NIGHT, AS UPPER JET SUPPORT DEVELOPS IN THE LEE OF THE TROUGH. THAT WILL WORK TO INCREASE COVERAGE OF SHOWERS AND A FEW THUNDERSTORMS FROM SOUTHWEST TO NORTHEAST ACROSS CENTRAL ILLINOIS SATURDAY NIGHT. AN INFLUX OF GULF MOISTURE WILL INCREASE LOW LEVEL INSTABILITY THROUGH THE WEEKEND. A BETTER CHANCE OF STRONG TO SEVERE STORMS LOOKS TO BE ON SUNDAY WHEN A SURFACE LOW LIFTS NORTHEAST ACROSS ILLINOIS. THE PASSAGE OF THE UPPER TROUGH AXIS SUNDAY NIGHT WILL CAUSE THUNDERSTORM CHANCES TO LINGER AT LEAST THROUGH MIDNIGHT. SPC HAS WESTERN IL IN THE DAY 4 15 PERCENT SEVERE OUTLOOK, WHICH INCLUDES 12Z SUNDAY TO 12Z MONDAY. WE KEPT LIKELY POPS ACROSS OUR AREA FROM LATE SATURDAY NIGHT THROUGH SUNDAY NIGHT. RAINFALL AND PERSISTENT CLOUD COVER SATURDAY NIGHT THROUGH SUNDAY NIGHT WILL LIMIT DIURNAL TEMP SWINGS. LOWS SAT NIGHT WILL BE IN THE MID TO UPPER 50S, WITH HIGHS NEAR 70 ON SUNDAY. A MORE SIGNIFICANT AIRMASS CHANGE IS EXPECTED TO BEGIN SUNDAY NIGHT BEHIND A DEPARTING SURFACE COLD FRONT. A LONG WAVE TROUGH ALOFT WILL SETTLE INTO THE HEARTLAND, ALLOWING COOLER CANADIAN AIR TO SETTLE INTO OUR AREA. LIGHT RAINFALL WILL LINGER ON MONDAY MORNING, MAINLY EAST OF I-55, BUT CLOUDS SHOULD EVENTUALLY BEGIN TO CLEAR ACROSS WESTERN IL MONDAY AFTERNOON. AN EXTENDED PERIOD OF TEMPS AT OR BELOW NORMAL WILL CONTINUE FROM MONDAY THROUGH AT LEAST WEDNESDAY, AS THE UPPER TROUGH STALLS OVER THE GREAT LAKES AND NW FLOW DOMINATES ALOFT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1157 PM CDT THU APR 16 2015 AREAS MVFR CONDITIONS WITH LOCAL IFR IN FOG FROM AROUND KCMI-K1H2 EASTWARD THIS EVENING...WITH VFR TO THE WEST AS A SURFACE HIGH PRESSURE CENTER REMAINS NEAR THE NORTHEAST CORNER OF THE STATE. FOG WILL SPREAD WESTWARD TO AROUND KBMI-KSPI EASTWARD WHERE GREATEST AMOUNTS OF LOW LEVEL MOISTURE REMAIN ALONG WITH LIGHT WINDS AND LACK OF HIGHER LEVEL CLOUD COVER. WITH DAYTIME HEATING...FOG SHOULD DISSIPATE 13Z-15Z WITH SCATTERED CUMULUS DEVELOPMENT ABOVE MVFR THRESHOLDS. LIGHT SSE WINDS 5-8 KTS DEVELOPING IN THE DAYTIME PERIOD...CONTINUING INTO EVENING. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ONTON SHORT TERM...HJS LONG TERM...SHIMON AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1027 PM EDT SAT APR 18 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 159 PM EDT SAT APR 18 2015 AS HIGH PRESSURE DEPARTS THE AREA TONIGHT...AN ACTIVE WEATHER PATTERN IS READY TO SET UP AS THE NEW WEEK BEGINS. LOW PRESSURE OVER LOWER MISSISSIPPI RIVER VALLEY IS EXPECTED TO PUSH ACROSS INDIANA ON SUNDAY...BRINGING RAIN AND PERHAPS A THUNDERSTORM. AS THE LOW PUSHES NORTHEAST TO THE GREAT LAKES ON SUNDAY NIGHT...A BROAD UPPER LEVEL LOW PRESSURE SYSTEM IS SET TO REMAIN IN PLACE OVER THE GREAT LAKES. WEAK WEATHER DISTURBANCES ALONG WITH COOLER AIR WILL PUSH ACROSS INDIANA FROM TIME TO TIME THROUGH TUESDAY...BRINGING DAILY CHANCES FOR SHOWERS AND PERHAPS A THUNDERSTORM. COOLER WEATHER IS EXPECTED THROUGH THE END OF THE WORK WEEK AS NORTHWEST FLOW FROM CANADA IS EXPECTED IN THE WAKE OF THE DEPARTING LOW. && .NEAR TERM /TONIGHT/... ISSUED AT 1005 PM EDT SAT APR 18 2015 PUSHED OFF ARRIVAL OF PRECIP IN THE SOUTH FOR ANOTHER FEW HOURS PER RADAR AND HRRR TRENDS. REMAINDER OF FORECAST IN GOOD SHAPE. SHOULD NOT BE SIGNIFICANT CHANGES TO THE GIST OF THE GOING FORECAST. PREVIOUS DISCUSSION FOLLOWS. ISSUED AT 159 PM EDT SAT APR 18 2015 SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED OVER WEST VIRGINIA. LOW PRESSURE HAD DEVELOPED OVER NORTHERN LOUISIANA. WATER VAPOR CONTINUED TO SHOW AN UPPER LEVEL LOW OVER COLORADO WITH A STREAM OF TROPICAL MOISTURE AHEAD OF THIS SYSTEM...STREAMING NORTH THROUGH THE MISSISSIPPI AND INTO THE OHIO VALLEY. DEW POINT TEMPS ACROSS CENTRAL INDIANA REMAINED IN THE DRY 40S...WHILE MORE MOIST AIR WITH DEW POINTS IN THE 60S WAS NOT FAR AWAY OVER WESTERN KENTUCKY. MAIN FORECAST CHALLENGE TONIGHT WILL BE POPS AND TEMPS. MUCH OF THIS FORECAST PERIOD WILL BE DRY AS BEST FORCING ASSOCIATED WITH THE APPROACHING LOW PRESSURE SYSTEM FROM THE SOUTHWEST FAILS TO ARRIVE UNTIL AFTER 06Z. DRY AIR REMAINS IN PLACE ACROSS THE REGION THROUGH THE EVENING. 300K GFS ISENTROPIC SURFACE SHOWS GOOD UPGLIDE AND A SURGE OF SPECIFIC HUMIDITIES IN EXCESS OF 7 G/KG NEAR 12Z...WITH AN EVEN BETTER SURGE AFTER 12Z SUNDAY.; FORECAST SOUNDINGS SHOW INCREASING SATURATION BY 12Z...WITH BEST SATURATION ACROSS THE SOUTHERN AREA WHERE MOISTURE IS EXPECTED FIRST. WITH EXCELLENT FORCING EXPECTED AS WITH THE ARRIVAL OF UPPER DYNAMICS...WILL TREND POPS HIGHER ACROSS THE SOUTHWEST WHERE MOIST SHOULD ARRIVE PRIOR TO 12Z...BUT STICK CLOSE TO GUIDANCE ELSEWHERE. THE EVENING SHOULD REMAIN DRY. GIVEN THE EXPECTED CLOUDS AND PRECIP WILL TREND LOWS AT OR ABOVE MAVMOS. && .SHORT TERM /SATURDAY THROUGH TUESDAY/... ISSUED AT 159 PM EDT SAT APR 18 2015 A WET DAY IS A GIVEN ON SUNDAY. GFS AND NAM BOTH SHOW DEEPLY SATURATED COLUMNS ON SUNDAY THROUGH THE MIDDLE OF THE DAY AS STRONG FORCING WORKS ACROSS THE AREA ASSOCIATED WITH THE PASSING SURFACE LOW. AS STATED ABOVE...THE GFS 300K ISENTROPIC SURFACE SHOWS EXCELLENT UPGLIDE ALONG WITH VERY MOIST SPECIFIC HUMIDITIES IN EXCESS OF 7 G/KG. THUS WILL USE 100 POPS ON SUNDAY...ALONG WITH TEMPS COOLER THAN MAVMOS GIVEN THE EXPECTED CLOUDS AND RAIN. GFS AND NAM SHOW THE FIRST WAVE OF FORCING DEPARTING THE AREA AFTER 00Z...HOWEVER BROAD CYCLONIC UPPER FLOW APPEARS TO DEVELOP AS THE UPPER LOW REACHES THE GREAT LAKES AND BEGINS TO MERGE AND DEEPEN WITH ANOTHER UPPER LOW SINKING OUT OF NORTHERN CANADA. AN ADDITIONAL SHORT WAVE EMBEDDED WITH THE FLOW LOOKS TO PASS ACROSS CENTRAL INDIANA ON SUNDAY NIGHT AND INTO MONDAY. AGAIN GOOD MOISTURE AND FORCING APPEARS IN PLACE. FORECAST SOUNDINGS SHOW DEEP SATURATION AGAIN ON MONDAY MORNING AS THIS WAVE PASSES. THUS WILL AGAIN TREND POPS HIGHER ON ON LATE SUNDAY NIGHT AND AGAIN ON MONDAY. GIVEN THE EXPECTED CLOUDS AND COLD AIR ADVECTION AND POSSIBLE RAIN SHOWERS WILL TREND LOWS WARMER THAN MAVMOS AND HIGHS COOLER. A BRIEF BREAK APPEARS ON MONDAY NIGHT AS THE PREVIOUS SECOND SHORT WAVE DEPARTS ACROSS THE AREA AND SOME SUBSIDENCE IS SEEN WITHIN THE BROAD CYCLONIC FLOW. GOOD MID LEVEL DRY AIR IS SEEN AS WELL AS WITHIN FORECAST SOUNDINGS. WILL TREND TOWARD A DRIER FORECAST ON MONDAY NIGHT...WITH LOWS AT OR BELOW MAVMOS. NAM AND GFS BOTH SUGGEST A WEAKER AND POORLY DEFINED SHORT WAVE PUSHES INTO THE AREA LATE ON TUESDAY. BEST FORCING APPEARS TO BE ACROSS THE SOUTHERN PARTS OF THE FORECAST AREA. FORECAST SOUNDINGS CONTINUE TO SHOW A RATHER DRY COLUMN WITH CONVECTIVE TEMPS REACHABLE IN THE LOWER 50S. HOWEVER PLENTY OF DRY AIR ALOFT WILL HAMPER SHOWER DEVELOPMENT. OVERALL CONFIDENCE IS LOW FOR THAT TIME. THUS WILL TREND TO POPS AT OR BELOW MEXMOS...AND STICK CLOSE ON HIGHS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 215 PM EDT SAT APR 18 2015 MODELS IN GENERAL AGREEMENT THAT THE EXTENDED WILL BE COOL WITH THE POTENTIAL FOR A FEW SHOWERS MAINLY TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AND AGAIN NEXT WEEKEND. WITH GOOD MODEL AGREEMENT...MADE LITTLE CHANGES TO REGIONAL BLEND POPS. 5400 METER 1000-500 MILLIBAR THICKNESS LINE ACROSS THE AREA THROUGH THE PERIOD STRONGLY SUPPORTS THE BELOW NORMAL BLEND TEMPERATURES WITH AFTERNOON HIGHS IN THE MID 50S TO LOWER 60S AND LOWS IN THE MID 30S TO LOWER 40S. && .AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/... ISSUED AT 1027 PM EDT SAT APR 18 2015 HI RES MODELS HAVE COME IN LINE AND ARE SLOWING DOWN ARRIVAL OF PRECIP SO PUSHED BACK TIMING AT THE SITES BY A COUPLE HOURS WITH THE UPDATE. PREVIOUS DISCUSSION FOLLOWS... VFR TO START THE PERIOD WITH WINDS OF 5-10 KTS GENERALLY OUT OF THE EAST. A SURFACE LOW WILL MOVE UP THE MISSISSIPPI AND THROUGH WESTERN INDIANA BRINGING RAIN AND IFR CONDITIONS TO THE SITES. THIS SHOULD START IN THE SOUTHERN SITES SOMETIME AFTER AROUND 11Z AND SPREAD NORTH FROM THERE. THE LATEST NAM RUN SHOWS THINGS A BIT SLOWER AND SREFS ARE LEANING THAT WAY AS WELL BUT THE HIGH RES MODELS ARE NOT ON BOARD. FOR NOW SLOWED THE TIMING OF ARRIVAL SLIGHTLY TO A MORE AVERAGE SOLUTION. WIND SPEEDS WILL INCREASE AS THE PRESSURE GRADIENT ACROSS THE AREA INCREASES LATER TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...PUMA NEAR TERM...PUMA/NIELD SHORT TERM...PUMA LONG TERM...MK AVIATION...CP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1005 PM EDT SAT APR 18 2015 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 159 PM EDT SAT APR 18 2015 AS HIGH PRESSURE DEPARTS THE AREA TONIGHT...AN ACTIVE WEATHER PATTERN IS READY TO SET UP AS THE NEW WEEK BEGINS. LOW PRESSURE OVER LOWER MISSISSIPPI RIVER VALLEY IS EXPECTED TO PUSH ACROSS INDIANA ON SUNDAY...BRINGING RAIN AND PERHAPS A THUNDERSTORM. AS THE LOW PUSHES NORTHEAST TO THE GREAT LAKES ON SUNDAY NIGHT...A BROAD UPPER LEVEL LOW PRESSURE SYSTEM IS SET TO REMAIN IN PLACE OVER THE GREAT LAKES. WEAK WEATHER DISTURBANCES ALONG WITH COOLER AIR WILL PUSH ACROSS INDIANA FROM TIME TO TIME THROUGH TUESDAY...BRINGING DAILY CHANCES FOR SHOWERS AND PERHAPS A THUNDERSTORM. COOLER WEATHER IS EXPECTED THROUGH THE END OF THE WORK WEEK AS NORTHWEST FLOW FROM CANADA IS EXPECTED IN THE WAKE OF THE DEPARTING LOW. && .NEAR TERM /TONIGHT/... ISSUED AT 1005 PM EDT SAT APR 18 2015 PUSHED OFF ARRIVAL OF PRECIP IN THE SOUTH FOR ANOTHER FEW HOURS PER RADAR AND HRRR TRENDS. REMAINDER OF FORECAST IN GOOD SHAPE. SHOULD NOT BE SIGNIFICANT CHANGES TO THE GIST OF THE GOING FORECAST. PREVIOUS DISCUSSION FOLLOWS. ISSUED AT 159 PM EDT SAT APR 18 2015 SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED OVER WEST VIRGINIA. LOW PRESSURE HAD DEVELOPED OVER NORTHERN LOUISIANA. WATER VAPOR CONTINUED TO SHOW AN UPPER LEVEL LOW OVER COLORADO WITH A STREAM OF TROPICAL MOISTURE AHEAD OF THIS SYSTEM...STREAMING NORTH THROUGH THE MISSISSIPPI AND INTO THE OHIO VALLEY. DEW POINT TEMPS ACROSS CENTRAL INDIANA REMAINED IN THE DRY 40S...WHILE MORE MOIST AIR WITH DEW POINTS IN THE 60S WAS NOT FAR AWAY OVER WESTERN KENTUCKY. MAIN FORECAST CHALLENGE TONIGHT WILL BE POPS AND TEMPS. MUCH OF THIS FORECAST PERIOD WILL BE DRY AS BEST FORCING ASSOCIATED WITH THE APPROACHING LOW PRESSURE SYSTEM FROM THE SOUTHWEST FAILS TO ARRIVE UNTIL AFTER 06Z. DRY AIR REMAINS IN PLACE ACROSS THE REGION THROUGH THE EVENING. 300K GFS ISENTROPIC SURFACE SHOWS GOOD UPGLIDE AND A SURGE OF SPECIFIC HUMIDITIES IN EXCESS OF 7 G/KG NEAR 12Z...WITH AN EVEN BETTER SURGE AFTER 12Z SUNDAY.; FORECAST SOUNDINGS SHOW INCREASING SATURATION BY 12Z...WITH BEST SATURATION ACROSS THE SOUTHERN AREA WHERE MOISTURE IS EXPECTED FIRST. WITH EXCELLENT FORCING EXPECTED AS WITH THE ARRIVAL OF UPPER DYNAMICS...WILL TREND POPS HIGHER ACROSS THE SOUTHWEST WHERE MOIST SHOULD ARRIVE PRIOR TO 12Z...BUT STICK CLOSE TO GUIDANCE ELSEWHERE. THE EVENING SHOULD REMAIN DRY. GIVEN THE EXPECTED CLOUDS AND PRECIP WILL TREND LOWS AT OR ABOVE MAVMOS. && .SHORT TERM /SATURDAY THROUGH TUESDAY/... ISSUED AT 159 PM EDT SAT APR 18 2015 A WET DAY IS A GIVEN ON SUNDAY. GFS AND NAM BOTH SHOW DEEPLY SATURATED COLUMNS ON SUNDAY THROUGH THE MIDDLE OF THE DAY AS STRONG FORCING WORKS ACROSS THE AREA ASSOCIATED WITH THE PASSING SURFACE LOW. AS STATED ABOVE...THE GFS 300K ISENTROPIC SURFACE SHOWS EXCELLENT UPGLIDE ALONG WITH VERY MOIST SPECIFIC HUMIDITIES IN EXCESS OF 7 G/KG. THUS WILL USE 100 POPS ON SUNDAY...ALONG WITH TEMPS COOLER THAN MAVMOS GIVEN THE EXPECTED CLOUDS AND RAIN. GFS AND NAM SHOW THE FIRST WAVE OF FORCING DEPARTING THE AREA AFTER 00Z...HOWEVER BROAD CYCLONIC UPPER FLOW APPEARS TO DEVELOP AS THE UPPER LOW REACHES THE GREAT LAKES AND BEGINS TO MERGE AND DEEPEN WITH ANOTHER UPPER LOW SINKING OUT OF NORTHERN CANADA. AN ADDITIONAL SHORT WAVE EMBEDDED WITH THE FLOW LOOKS TO PASS ACROSS CENTRAL INDIANA ON SUNDAY NIGHT AND INTO MONDAY. AGAIN GOOD MOISTURE AND FORCING APPEARS IN PLACE. FORECAST SOUNDINGS SHOW DEEP SATURATION AGAIN ON MONDAY MORNING AS THIS WAVE PASSES. THUS WILL AGAIN TREND POPS HIGHER ON ON LATE SUNDAY NIGHT AND AGAIN ON MONDAY. GIVEN THE EXPECTED CLOUDS AND COLD AIR ADVECTION AND POSSIBLE RAIN SHOWERS WILL TREND LOWS WARMER THAN MAVMOS AND HIGHS COOLER. A BRIEF BREAK APPEARS ON MONDAY NIGHT AS THE PREVIOUS SECOND SHORT WAVE DEPARTS ACROSS THE AREA AND SOME SUBSIDENCE IS SEEN WITHIN THE BROAD CYCLONIC FLOW. GOOD MID LEVEL DRY AIR IS SEEN AS WELL AS WITHIN FORECAST SOUNDINGS. WILL TREND TOWARD A DRIER FORECAST ON MONDAY NIGHT...WITH LOWS AT OR BELOW MAVMOS. NAM AND GFS BOTH SUGGEST A WEAKER AND POORLY DEFINED SHORT WAVE PUSHES INTO THE AREA LATE ON TUESDAY. BEST FORCING APPEARS TO BE ACROSS THE SOUTHERN PARTS OF THE FORECAST AREA. FORECAST SOUNDINGS CONTINUE TO SHOW A RATHER DRY COLUMN WITH CONVECTIVE TEMPS REACHABLE IN THE LOWER 50S. HOWEVER PLENTY OF DRY AIR ALOFT WILL HAMPER SHOWER DEVELOPMENT. OVERALL CONFIDENCE IS LOW FOR THAT TIME. THUS WILL TREND TO POPS AT OR BELOW MEXMOS...AND STICK CLOSE ON HIGHS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... ISSUED AT 215 PM EDT SAT APR 18 2015 MODELS IN GENERAL AGREEMENT THAT THE EXTENDED WILL BE COOL WITH THE POTENTIAL FOR A FEW SHOWERS MAINLY TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AND AGAIN NEXT WEEKEND. WITH GOOD MODEL AGREEMENT...MADE LITTLE CHANGES TO REGIONAL BLEND POPS. 5400 METER 1000-500 MILLIBAR THICKNESS LINE ACROSS THE AREA THROUGH THE PERIOD STRONGLY SUPPORTS THE BELOW NORMAL BLEND TEMPERATURES WITH AFTERNOON HIGHS IN THE MID 50S TO LOWER 60S AND LOWS IN THE MID 30S TO LOWER 40S. && .AVIATION /DISCUSSION FOR 190000Z TAF ISSUANCE/... ISSUED AT 721 PM EDT SAT APR 18 2015 VFR TO START THE PERIOD WITH WINDS OF 5-10 KTS GENERALLY OUT OF THE EAST. A SURFACE LOW WILL MOVE UP THE MISSISSIPPI AND THROUGH WESTERN INDIANA BRINGING RAIN AND IFR CONDITIONS TO THE SITES. THIS SHOULD START IN THE SOUTHERN SITES SOMETIME AFTER AROUND 11Z AND SPREAD NORTH FROM THERE. THE LATEST NAM RUN SHOWS THINGS A BIT SLOWER AND SREFS ARE LEANING THAT WAY AS WELL BUT THE HIGH RES MODELS ARE NOT ON BOARD. FOR NOW SLOWED THE TIMING OF ARRIVAL SLIGHTLY TO A MORE AVERAGE SOLUTION. WIND SPEEDS WILL INCREASE AS THE PRESSURE GRADIENT ACROSS THE AREA INCREASES LATER TONIGHT. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...PUMA NEAR TERM...PUMA/NIELD SHORT TERM...PUMA LONG TERM...MK AVIATION...CP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSINDIANAPOLIS WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 PM CDT SAT APR 18 2015 ...UPDATED AVIATION DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 222 PM CDT SAT APR 18 2015 ABBREVIATED SHORT TERM DUE TO CONVECTION ALREADY IN PROGRESS. THE GENERAL STORY THIS AFTERNOON AND EVENING IS ANOTHER ROUND OF SEVERE WEATHER. THINK THE MOST LIKEST PLACE (IN ADDITION TO WHAT IS OCCURRING NOW), IS ALONG AND EAST OF A DRYLINE. THIS EXTENDS ROUGHLY FROM TREGO COUNTY, JUST EAST OF DODGE CITY, AND DOWN TO EAST CENTRAL CLARK COUNTY. INSTABILITY AND BULK SHEAR ARE SUPPORTIVE OF ORGANIZED THUNDERSTORMS. MESOSCALE GUIDANCE SUGGESTS SOME SUPERCELLS ARE POSSIBLE EARLY IN THE EVENT AND THEN STORM TYPE EVOLVING INTO A LINE ACROSS SOUTH CENTRAL KANSAS BY MID EVENING. INITIALLY, IT WILL BE A LARGE HAIL EVENT WITH THE LHP FORECAST HAIL SIZE OF AROUND 2". THIS SHOULD BE THE MAX SIZE. UPPER LEVEL WINDS BACK WITH HEIGHT WITH TIME, SO THINK BENEFICIAL COMPETITION WILL INCREASE AS TIME GOES FORWARD...HENCE, HAIL SIZE GROWTH POTENTIAL WILL BE SOMEWHAT MITIGATED. FOR A TORNADO CONCERN, LOW LEVEL SHEAR IS ON THE WEAK SIDE. THERE IS A SLIGHT WINDOW ACROSS BARBER, COMANCHE, AND PRATT COUNTIES, WHERE THIS IMPROVES THIS EVENING. HOWEVER, THINK ACTIVITY WON`T BE AS DISCRETE BY THAT TIME. THE MAIN THREAT WOULD THEN EVOLVE INTO A CONVECTIVE WIND OUTFLOW CONCERN. BOTTOM LINE, THE OVERALL ENVIRONMENT IS JUST NOT THAT CONDUCIVE FOR TORNADOES, EXCEPT IN THE ABOVE MENTIONED AREA ACROSS SOUTH-CENTRAL KANSAS AND ONLY FOR A SMALL WINDOW. OTHERWISE, SEVERE ACTIVITY WILL BE OUT OF THE REGION BY 03Z OR SO. A DEFORMATION BAND IS FORECAST BEHIND THE MID TO LOW LEVEL PRESSURE PERTURBATION AND THINK SHOWERS AND ISOLATED THUNDERSTORMS IN ITS WAKE. THE MESOSCALE MODELS SHOW DECENT QPF WITH THIS ACTIVITY, SO OUR WESTERN AND NORTHWESTERN COUNTIES MIGHT SEE ADDITIONAL RAINFALL. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 245 PM CDT SAT APR 18 2015 MEDIUM RANGE MODELS INDICATE A BROAD UPPER LEVEL TROUGH OF LOW PRESSURE TRANSITIONING SLOWLY EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS EARLY IN THE WEEK SETTING UP GENERAL WESTERLY FLOW ALOFT ACROSS THE WESTERN HIGH PLAINS. MEANWHILE, A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PUSH ASHORE INTO THE PACIFIC NORTHWEST. ALONG WITH A WEAKER FLOW ALOFT AND DRIER AIR PRESENT IN THE LOWER/MID LEVELS, PRECIP CHANCES WILL REMAIN ABSENT ACROSS MUCH OF WESTERN KANSAS THROUGH MONDAY EVENING. HOWEVER, THERE IS AN OUTSIDE CHANCE FOR THUNDERSTORMS ACROSS EXTREME SOUTHWESTERN KANSAS LATE MONDAY NIGHT AS INCREASED MOISTURE ASSOCIATED WITH A SERIES OF H5 VORT MAXIMA BEGINS TO MOVE OFF THE COLORADO ROCKIES SOUTHEASTWARD INTO THE HIGH PLAINS. HELPING SET THE STAGE FOR INCREASING PRECIP CHANCES WILL BE SURFACE HIGH PRESSURE MOVING SOUTHEAST OUT OF KANSAS INTO THE LOWER MISSISSIPPI RIVER VALLEY, BRINGING ABOUT A SOUTHEASTERLY UPSLOPE FLOW FROM THE SOUTH PLAINS UP INTO THE OKLAHOMA PANHANDLE AND SOUTHWEST KANSAS. BECAUSE OF DRIER AIR REMAINING IN THE LOWER/MID LEVELS, ANY STORM DEVELOPMENT IS LIKELY TO BE ISOLATED AND HIGH BASED. PRECIP CHANCES RETURN IN EARNEST MID TO LATE WEEK AS AN UPPER LEVEL SHORTWAVE PUSHING ASHORE INTO SOUTHERN CALIFORNIA EARLY IN THE WEEK MOVES FURTHER EAST INTO THE DESERT SOUTHWEST. COOLER AND BELOW NORMAL TEMPERATURES ARE TO BE EXPECTED MONDAY IN WAKE OF A COLD FRONTAL PASSAGE ON SUNDAY. COOLER AIR WILL FILTER SOUTHWARD INTO WESTERN KANSAS WITH H85 TEMPERATURES DOWN INTO THE MID SINGLE DIGITS(C) ACROSS CENTRAL AND SOUTHWEST KANSAS. WITH THE HELP OF A NORTHWESTERLY DOWNSLOPE FLOW, HIGHS MAY REACH THE LOWER TO MID 60S(F) MONDAY AFTERNOON. HIGHS ARE EXPECTED TO CLIMB WELL INTO THE 60S(F) TUESDAY WITH A SLIGHT WARM UP TO THE AIR MASS ACROSS THE HIGH PLAINS. THE GENERAL WARMING TREND IS LIKELY TO CONTINUE THROUGH WEDNESDAY AS THE GENERAL FLOW NEAR THE SURFACE BECOMES MORE SOUTHERLY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 614 PM CDT SAT APR 18 2015 VFR CONDITIONS CAN BE EXPECTED OVERNIGHT. WESTERLY WINDS AT 10 TO 15 KNOTS WILL DEVELOP EARLY TONIGHT AS A SURFACE BOUNDARY MOVES FROM WESTERN KANSAS INTO CENTRAL KANSAS THROUGH 06Z SUNDAY. WINDS JUST BEHIND THIS BOUNDARY GUSTY NORTHWEST WINDS WILL BRIEFLY DEVELOP. EVENING CONVECTION EAST OF DDC AND HYS IS ALSO EXPECTED TO TAPER OFF FROM WEST TO EAST AS AN UPPER LEVEL DISTURBANCE CROSSES WESTERN KANSAS. AS THE WINDS VEER MORE TO THE NORTHWEST TOWARDS 12Z SUNDAY THE LOWER LEVELS WILL BEGIN TO SATURATE. BASED ON THE HRRR AND RAP ALONG WITH THE BUFR SOUNDINGS SOME MVFR OR IFR STATUS WILL BE POSSIBLE EARLY SUNDAY MORNING AFTER 12Z SUNDAY. NORTHWESTERLY WINDS WILL ALSO BE ON THE INCREASE EARLY SUNDAY AND BY 18Z SUNDAY WIND SPEEDS OF AT LEAST 25 KNOTS WILL BE LIKELY AT ALL THREE TAF SITES. && .PRELIMINARY POINT TEMPS/POPS... DDC 46 59 36 61 / 50 70 10 10 GCK 43 56 34 60 / 50 70 10 10 EHA 41 57 36 61 / 30 30 10 20 LBL 43 58 37 61 / 30 40 10 10 HYS 49 58 34 61 / 70 70 0 10 P28 51 67 38 63 / 70 70 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SUGDEN LONG TERM...JJOHNSON AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
349 PM CDT Fri Apr 17 2015 .SHORT TERM...(This Evening through Saturday) Issued at 346 PM CDT FRI APR 17 2015 Upper low continues to spin over the Rockies this afternoon with an upper level jet rounding the base of the upper low and moving over New Mexico. Earlier showers and thunderstorms were moving out of the northern counties at 20Z. Some clearing was occurring across the southern and western sections of the cwa this afternoon. Latest meso analysis shows surface based CAPE around 500 to 1000 J/kg with an uncapped atmosphere. Expect scattered convection to develop in southwest Kansas along the dry line. additional scattered storms may develop in south west and south central Kansas per the latest runs of the RAP and HRRR. Models suggest additional development this evening across western and central Kansas moving northeast into north central Kansas with the increase and veering of the low level jet overnight. Models are in agreement with a lobe of energy working it`s way northeast out of Oklahoma later tonight and Saturday morning. May see a repeat of this morning with an area of showers and embedded thunderstorms moving across the area. Expect a break for a few hours in the afternoon, then chances increase again with storms developing again in the afternoon in western and central Kansas as upward vertical motion increases with the advance of the upper trough into the High Plains. Dryline looks to set up across western Kansas with the GFS the furthest east in central Kansas. Shear and instability will be favorable for some of the storms to be strong to severe with large hail and winds the main hazards in the late afternoon hours mainly west of a Herington to Washington line. .LONG TERM...(Saturday Night through Friday) Issued at 346 PM CDT FRI APR 17 2015 Short range models are relatively consistent in moving surface low and main piece of upper trough through eastern KS late Saturday night and Sunday. Ahead of this system Saturday night, increasing thunderstorm chances are expected, with some potential for severe weather, with the best chance in our forecast area over the western 2/3. Shear parameters are not very impressive and amount of sunshine and associated surface heating Sat afternoon and evening is also a little suspect so this is not a high probability thing. As the low and front move through on Sunday, some isolated thunder may continue in the east in the morning, but showers associated with cold air aloft just behind the front will continue precip chances into the afternoon hours. After that, subsidence and cold advection behind that system brings in dry conditions and cooler temperatures for Sunday night through Tuesday, with lows dipping into the upper 30s many places and highs in the low to mid 60s. Precip chances return to parts of eastern KS on Wednesday when weak low-level warm advection and a weak wave in northwest flow aloft interact. Latest ECMWF and GEM would indicate that the cool air at the surface is more entrenched in place than the GFS, thus have gone cooler than guidance for highs on Wednesday. Beyond Wednesday, considerable differences exist between 12Z GFS and ECMWF in upper flow pattern and precip chances. GFS and GFSEnsemble places us in a more favorable pattern for a couple days of precip for Thursday and Friday, while the ECMWF is slower in bringing a shortwave trough out of the southwest U.S., and would give us the better chances on Friday. Have gone with a general compromise with 25 to 40 percent POPs for those days. && .AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon) Issued at 105 PM CDT FRI APR 17 2015 VFR conditions are expected through the period outside of convection. Expect isolated tsra this afternoon and evening then a better chance of more widespread shra and isolated tsra after 08Z through the end of the period. MVFR vsbys are expected along with brief reductions of cigs into the mvfr category. Winds remain east southeast through the period generally less than 10 kts. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...GDP AVIATION...53
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
335 AM CDT FRI APR 17 2015 ...UPDATED FOR LONG TERM... .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 120 PM CDT THU APR 16 2015 IN THE SHORT TERM, A FEW (2-3) ROUNDS OF CONVECTION ARE ANTICIPATED THROUGH HE NEXT 24 TO 36 HOURS OR SO AS A LARGE UPPER LOW MOVES TOWARD THE REGION WITH FORCING FOR ASCENT, AND PERSISTENT MID LEVEL MOISTURE ADVECTION TO MAINTAIN INSTABILITY FOR A PROLONGED PERIOD. THE FIRST ROUNDS ARE EXPECTED ALREADY EARLY THIS AFTERNOON AS THE NESTED 4 KM NAM AND HRRR MODELS HAVE GENERALLY AGREED ON CONVECTIVE INITIATION BETWEEN AROUND 2 AND 4 PM, AND RAPIDLY DEVELOPING INTO A MULTICELLULAR LINE AFTER AN HOUR OR SO OF SLOWER GROWING DISCREET CELLS. THE INITIAL ROTATING STORMS GENERALLY WEST OF HIGHWAY 83 SHOULD BE CAPABLE OF PRODUCING HAIL LARGER THAN GOLFBALLS AND DAMAGING WIND BEFORE THE STORMS BECOME MORE CLUSTERED OR LINEAR, PRESENTING A SLIGHTLY SMALLER HAIL THREAT AND STILL DAMAGING WIND THREAT THROUGH THE HIGHWAY 283 AND 183 CORRIDORS INTO THE EARLY EVENING HOURS. THESE MODEL SOLUTIONS COULD BE INTERFERED WITH BY THE EXTENSIVE STRATUS ACROSS THE AREA REDUCING THE SEVERE THREAT. ANOTHER ROUND OF THUNDERSTORMS WILL PROBABLY OCCUR LATE TONIGHT INTO THE OVERNIGHT AND POSSIBLY STILL ONGOING EARLY FRIDAY MORNING, WITH A CONTINUED HAIL IF NOT AN ISOLATED WIND THREAT AS WELL, ALTHOUGH SOME BL STABILITY SHOULD HINDER THE WIND THREAT. THE DYNAMICS OF THE UPPER LOW WILL DRIVE A DRY SLOT THROUGH THE REGION OF FRIDAY, BUT NOT BEFORE LATE MORNING/EARLY AFTERNOON DESTABILIZATION CONTRIBUTES TO YET ANOTHER SEVERE EPISODE WITH AS GOOD OR BETTER CAPE AND SHEAR COMBINATIONS. TEMPERATURES WERE RAISED FOR FRIDAY MORNING, FOLLOWING THE NAM AND GFS, AS OVERNIGHT CONVECTION SHOULD LIMIT THE RADIATIONAL COOLING. ADDITIONALLY THE POPS WERE RAISED LOWERED FRIDAY MORNING AND INCREASED ALONG THE MOISTURE TRANSPORT AXIS INTO FRIDAY AFTERNOON WITH A MODEL CONSENSUS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 334 AM CDT FRI APR 17 2015 FOR SATURDAY, THE UPPER LOW IS FORECAST TO MOVE FROM CENTRAL COLORADO AND INTO EASTERN COLORADO BY EVENING. A DRYLINE IS FORECAST TO PUSH TOWARDS DODGE CITY BY LATE AFTERNOON AND EVENING. THE NAM MODEL KEEPS THE DRYLINE FARTHER WEST, WHILE THE GFS PUSHES IT WELL EAST INTO PARTS OF SOUTH CENTRAL KANSAS. TYPICALLY MODELS PUSH THE DRYLINE MORE EAST THAN WHAT ACTUAL HAPPENS SO WILL GO WITH THE NAM FOR NOW THAT AGREES WITH SPC SEVERE SLIGHT RISK FORECAST. CAPES ARE FORECAST TO RUN FROM 1500-2000 J/KG. SOME NEGATIVES FOR WIDESPREAD SEVERE ARE WEAKNESS IN THE MID AND UPPER LEVEL WINDS. SOME SEVERE THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF THE DRYLINE BY AFTERNOON INTO THE EVENING WITH LARGE HAIL FROM QUARTER TO GOLFBALL WITH THE MID LEVELS FAIRLY COLD AROUND -17 CELSIUS. HIGHS ON SATURDAY WILL RANGE FROM THE UPPER 60S FAR WEST TO THE MID 70 OVER SOUTH CENTRAL SECTIONS OF KANSAS. FOR SATURDAY NIGHT WILL CONTINUE WITH A CHANCE OR SHOWERS AND ISOLATED THUNDERSTORMS WITH OVERNIGHT LOWS IN THE MID AND UPPER 40S. FOR SUNDAY, THE UPPER LOW AND TROUGH MOVES INTO EASTERN KANSAS WITH ONLY SOME LEFT OVER RAIN SHOWERS MAINLY NORTH AND EAST OF DODGE CITY AS A COLD FRONT MOVES ACROSS WESTERN KANSAS. THUNDERSTORMS ARE ALSO POSSIBLE IN THE PARTS OF SOUTH CENTRAL KANSAS WITH BETTER INSTABILITY FROM PRATT AND COLDWATER AND SOUTH. HIGHS ON SUNDAY WILL BE IN THE LOW TO MID 60S. LOWS SUNDAY NIGHT WILL RANGE FROM THE MID 30 NORTH AROUND THE I-70 CORRIDOR TO UPPER 30S AND LOW 40S SOUTH FROM DODGE CITY TO THE OKLAHOMA BORDER. FOR THE PERIOD OF MONDAY INTO THURSDAY, SOME DISTURBANCES IN NORTHWESTERLY FLOW COULD BRING SOME SMALL CHANCES FOR RAIN SHOWERS AND OR THUNDERSTORMS, WITH THE BEST CHANCES TOWARDS WEDNESDAY INTO THURSDAY AS GULF MOISTURE RETURNS. HIGH TEMPS WILL RUN IN THE 60S MONDAY AND TUESDAY, AND AROUND 70 ON WEDNESDAY AND THURSDAY. LOWS WILL RANGE FROM THE UPPER 30S TUESDAY MORNING, THEN INTO THE 40S INTO THURSDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1256 AM CDT FRI APR 17 2015 AREAS OF RAIN AND THUNDERSTORMS WILL AFFECT THE TAF SITES PERIODICALLY THROUGH THE PERIOD. MUCH OF THE TIME, VFR CONDITIONS WILL PERSIST, WITH SOUTHEAST WINDS AT 10 TO 15 KTS OUTSIDE OF THUNDERSTORMS. VISIBILITIES MAY DROP TO MVFR IN ANY THUNDERSTORMS WITH CEILINGS REMAINING VFR/MVFR, EXCEPT FOR IN ANY HEAVIER SHOWERS. && .PRELIMINARY POINT TEMPS/POPS... DDC 71 52 72 46 / 60 60 40 50 GCK 71 48 69 45 / 50 50 30 40 EHA 71 42 68 44 / 10 20 20 30 LBL 71 46 71 46 / 30 40 30 30 HYS 70 56 72 49 / 70 70 50 50 P28 71 56 75 51 / 70 70 40 40 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING FOR KSZ084. && $$ SHORT TERM...RUSSELL LONG TERM...KRUSE AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1259 AM CDT FRI APR 17 2015 ...UPDATED FOR AVIATION DISCUSSION... .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 120 PM CDT THU APR 16 2015 IN THE SHORT TERM, A FEW (2-3) ROUNDS OF CONVECTION ARE ANTICIPATED THROUGH HE NEXT 24 TO 36 HOURS OR SO AS A LARGE UPPER LOW MOVES TOWARD THE REGION WITH FORCING FOR ASCENT, AND PERSISTENT MID LEVEL MOISTURE ADVECTION TO MAINTAIN INSTABILITY FOR A PROLONGED PERIOD. THE FIRST ROUNDS ARE EXPECTED ALREADY EARLY THIS AFTERNOON AS THE NESTED 4 KM NAM AND HRRR MODELS HAVE GENERALLY AGREED ON CONVECTIVE INITIATION BETWEEN AROUND 2 AND 4 PM, AND RAPIDLY DEVELOPING INTO A MULTICELLULAR LINE AFTER AN HOUR OR SO OF SLOWER GROWING DISCREET CELLS. THE INITIAL ROTATING STORMS GENERALLY WEST OF HIGHWAY 83 SHOULD BE CAPABLE OF PRODUCING HAIL LARGER THAN GOLFBALLS AND DAMAGING WIND BEFORE THE STORMS BECOME MORE CLUSTERED OR LINEAR, PRESENTING A SLIGHTLY SMALLER HAIL THREAT AND STILL DAMAGING WIND THREAT THROUGH THE HIGHWAY 283 AND 183 CORRIDORS INTO THE EARLY EVENING HOURS. THESE MODEL SOLUTIONS COULD BE INTERFERED WITH BY THE EXTENSIVE STRATUS ACROSS THE AREA REDUCING THE SEVERE THREAT. ANOTHER ROUND OF THUNDERSTORMS WILL PROBABLY OCCUR LATE TONIGHT INTO THE OVERNIGHT AND POSSIBLY STILL ONGOING EARLY FRIDAY MORNING, WITH A CONTINUED HAIL IF NOT AN ISOLATED WIND THREAT AS WELL, ALTHOUGH SOME BL STABILITY SHOULD HINDER THE WIND THREAT. THE DYNAMICS OF THE UPPER LOW WILL DRIVE A DRY SLOT THROUGH THE REGION OF FRIDAY, BUT NOT BEFORE LATE MORNING/EARLY AFTERNOON DESTABILIZATION CONTRIBUTES TO YET ANOTHER SEVERE EPISODE WITH AS GOOD OR BETTER CAPE AND SHEAR COMBINATIONS. TEMPERATURES WERE RAISED FOR FRIDAY MORNING, FOLLOWING THE NAM AND GFS, AS OVERNIGHT CONVECTION SHOULD LIMIT THE RADIATIONAL COOLING. ADDITIONALLY THE POPS WERE RAISED LOWERED FRIDAY MORNING AND INCREASED ALONG THE MOISTURE TRANSPORT AXIS INTO FRIDAY AFTERNOON WITH A MODEL CONSENSUS. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 1152 AM CDT THU APR 16 2015 FRIDAY NIGHT INTO SATURDAY WE WILL STILL BE DEALING WITH THE SLOW- MOVING UPPER LOW, BUT BY THIS TIME THE LOW WILL BE SEVERELY OCCLUDED WITH THE DRY INTRUSION WORKING IN FAST FROM THE SOUTHWEST. IN FACT, FRIDAY NIGHT LOOKS RATHER DRY NOW WITH THE SYNOPTIC DRY INTRUSION ACROSS MUCH OF KANSAS. WE HAVE REDUCED POPS AS A RESULT FRIDAY NIGHT. AS WE HEAD INTO SATURDAY, ANY DAYTIME HEATING WILL PROMOTE SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT AS THE CORE OF THE MID LEVEL CYCLONE WALLOWS SLOWLY EASTWARD INTO FAR WESTERN KANSAS. WE WILL MAINTAIN THE 20-40 POPS ACROSS MAINLY THE NORTHERN AND EASTERN ZONES WITH A DRY FORECAST ACROSS FAR SOUTHWEST KANSAS. WHAT IS LEFT OF THE LOW WILL FINALLY PULL AWAY SATURDAY NIGHT INTO EARLY SUNDAY WITH FAIRLY STRONG NORTH WINDS TO FOLLOW DURING THE DAY SUNDAY. WE COULD STILL SEE SOME WRAP-AROUND LIGHT PRECIPITATION IN THE WEAKENING MID LEVEL DEFORMATION AXIS, HENCE THE 20 TOP 30 POPS FOR MUCH OF THE AREA. LOOKING BEYOND THE WEEKEND, WE WILL ENTER A NORTHWEST FLOW PATTERN ON THE SOUTHWEST SIDE OF A LARGE-SCALE UPPER TROUGH ACROSS THE GREAT LAKES REGION. THE ATMOSPHERE WILL BE FAIRLY COOL EARLY NEXT WEEK AS A RESULT WITH LARGE SCALE HIGH PRESSURE AT THE SURFACE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1256 AM CDT FRI APR 17 2015 AREAS OF RAIN AND THUNDERSTORMS WILL AFFECT THE TAF SITES PERIODICALLY THROUGH THE PERIOD. MUCH OF THE TIME, VFR CONDITIONS WILL PERSIST, WITH SOUTHEAST WINDS AT 10 TO 15 KTS OUTSIDE OF THUNDERSTORMS. VISIBILITIES MAY DROP TO MVFR IN ANY THUNDERSTORMS WITH CEILINGS REMAINING VFR/MVFR, EXCEPT FOR IN ANY HEAVIER SHOWERS. && .PRELIMINARY POINT TEMPS/POPS... DDC 52 69 45 65 / 60 30 40 30 GCK 48 69 44 62 / 60 30 40 30 EHA 42 66 43 62 / 30 20 20 20 LBL 46 69 45 63 / 40 30 30 20 HYS 56 71 48 62 / 60 50 50 40 P28 56 72 51 67 / 60 40 50 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...RUSSELL LONG TERM...UMSCHEID AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS JACKSON KY
200 PM EDT FRI APR 17 2015 .UPDATE... ISSUED AT 200 PM EDT FRI APR 17 2015 QUICK UPDATE TO ALIGN T AND TD GRIDS WITH MOST RECENT OBS. NO OTHER CHANGES WERE MADE TO THE FORECAST. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 1058 AM EDT FRI APR 17 2015 WV IMAGERY INDICATES THAT THE WEAK TROUGH HAS PUSHED EAST OF THE AREA SO HAVE TRENDED POPS DOWN OVER THE NEXT 3 TO 6 HOURS...STILL KEPT A SLIGHT CHANCE IN OUR SOUTHEASTERN COUNTIES TO REMAIN WITHIN TOLERANCE WITH OUR NEIGHBORS DURING THAT TIME. OTHERWISE...IT/S JUST A CLOUD COVER AND TEMPERATURE FORECAST TODAY. SO HAVE UPDATED T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. NO OTHER CHANGES WERE MADE TO THE CURRENT FORECAST BUT WILL KEEP AN EYE ON CLOUD COVER AND TEMPS INTO THE AFTERNOON. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 809 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH. THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN. IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND ONLY SHOWERS EXPECTED. HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE PRECIP WILL BE AFTER 00Z SUNDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM EDT FRI APR 17 2015 CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS WOULD SUGGEST PWATS BETWEEN 1.2 AND 1.4 INCHES DURING THIS PERIOD AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM. PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 155 PM EDT FRI APR 17 2015 LOW LEVEL CLOUDS HAVE HAD A HARD TIME BREAKING UP THIS AFTERNOON. BUT GIVEN RECENT VIS IMAGERY TRENDS...EXPECT MUCH OF THE REMAINING CLOUD COVER TO CONTINUE BREAKING UP AND CIGS TO IMPROVE TO VFR THROUGHOUT THE REMAINDER OF THE AFTERNOON. HIGH PRESSURE MOVING IN LATER THIS EVENING AND TONIGHT ALONG WITH LIGHT WINDS WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR FOG DEVELOPMENT AND SO HAVE PUT IFR VIS IN THE LOZ...JKL...SJS...SYM TAF SITES AND ALTERNATE MINS AT THE SME TAF SITE TONIGHT AFTER 06Z. CONDITIONS SHOULD THEN IMPROVE TO VFR ACROSS ALL TAF SITES AROUND 13Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...SHALLENBERGER LONG TERM...DJ AVIATION...JVM
AREA FORECAST DISCUSSION
NWS JACKSON KY
155 PM EDT FRI APR 17 2015 .UPDATE... ISSUED AT 1058 AM EDT FRI APR 17 2015 WV IMAGERY INDICATES THAT THE WEAK TROUGH HAS PUSHED EAST OF THE AREA SO HAVE TRENDED POPS DOWN OVER THE NEXT 3 TO 6 HOURS...STILL KEPT A SLIGHT CHANCE IN OUR SOUTHEASTERN COUNTIES TO REMAIN WITHIN TOLERANCE WITH OUR NEIGHBORS DURING THAT TIME. OTHERWISE...IT/S JUST A CLOUD COVER AND TEMPERATURE FORECAST TODAY. SO HAVE UPDATED T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. NO OTHER CHANGES WERE MADE TO THE CURRENT FORECAST BUT WILL KEEP AN EYE ON CLOUD COVER AND TEMPS INTO THE AFTERNOON. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 809 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH. THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN. IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND ONLY SHOWERS EXPECTED. HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE PRECIP WILL BE AFTER 00Z SUNDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM EDT FRI APR 17 2015 CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS WOULD SUGGEST PWATS BETWEEN 1.2 AND 1.4 INCHES DURING THIS PERIOD AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM. PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 155 PM EDT FRI APR 17 2015 LOW LEVEL CLOUDS HAVE HAD A HARD TIME BREAKING UP THIS AFTERNOON. BUT GIVEN RECENT VIS IMAGERY TRENDS...EXPECT MUCH OF THE REMAINING CLOUD COVER TO CONTINUE BREAKING UP AND CIGS TO IMPROVE TO VFR THROUGHOUT THE REMAINDER OF THE AFTERNOON. HIGH PRESSURE MOVING IN LATER THIS EVENING AND TONIGHT ALONG WITH LIGHT WINDS WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR FOG DEVELOPMENT AND SO HAVE PUT IFR VIS IN THE LOZ...JKL...SJS...SYM TAF SITES AND ALTERNATE MINS AT THE SME TAF SITE TONIGHT AFTER 06Z. CONDITIONS SHOULD THEN IMPROVE TO VFR ACROSS ALL TAF SITES AROUND 13Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...SHALLENBERGER LONG TERM...DJ AVIATION...JVM
AREA FORECAST DISCUSSION
NWS JACKSON KY
1058 AM EDT FRI APR 17 2015 .UPDATE... ISSUED AT 1058 AM EDT FRI APR 17 2015 WV IMAGERY INDICATES THAT THE WEAK TROUGH HAS PUSHED EAST OF THE AREA SO HAVE TRENDED POPS DOWN OVER THE NEXT 3 TO 6 HOURS...STILL KEPT A SLIGHT CHANCE IN OUR SOUTHEASTERN COUNTIES TO REMAIN WITHIN TOLERANCE WITH OUR NEIGHBORS DURING THAT TIME. OTHERWISE...IT/S JUST A CLOUD COVER AND TEMPERATURE FORECAST TODAY. SO HAVE UPDATED T AND TD GRIDS TO ALIGN WITH MOST RECENT OBS. NO OTHER CHANGES WERE MADE TO THE CURRENT FORECAST BUT WILL KEEP AN EYE ON CLOUD COVER AND TEMPS INTO THE AFTERNOON. SENT UPDATED GRIDS TO NDFD AND WEB SERVERS. UPDATE ISSUED AT 809 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH. THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN. IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND ONLY SHOWERS EXPECTED. HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE PRECIP WILL BE AFTER 00Z SUNDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM EDT FRI APR 17 2015 CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS WOULD SUGGEST PWATS BETWEEN 1.2 AND 1.4 INCHES DURING THIS PERIOD AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM. PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 809 AM EDT FRI APR 17 2015 SOME LOW LEVEL CLOUD COVER ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH FROM THE NORTHWEST WILL BRING SOME 2 TO 3 KFT CEILINGS THROUGH THE AREA BETWEEN 12Z AND 15Z THIS MORNING. AFTERWARD...SKIES WILL BEGIN TO CLEAR OUT BY THE AFTERNOON AND EVENING. HIGH PRESSURE MOVING IN LATER THIS EVENING AND TONIGHT ALONG WITH LIGHT WINDS WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR FOG DEVELOPMENT AND SO HAVE PUT IFR VIS IN ALL THE TAF SITES TONIGHT AFTER 06Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JVM SHORT TERM...SHALLENBERGER LONG TERM...DJ AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
810 AM EDT FRI APR 17 2015 .UPDATE... ISSUED AT 809 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME LOW LEVEL CLOUDS JUST TO THE WEST ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH. THIS HAS ALSO SPAWNED A FEW SHOWERS ACROSS THE AREA. RECENT RADAR RETURNS HINT AT SOME OF THE ACTIVITY MAYBE DEVELOPING FURTHER SOUTH SO HAVE LEFT POPS IN THROUGH MIDDAY. AS WELL HAVE PUT FOG IN THE FORECAST LATE TONIGHT. WITH HIGH PRESSURE MOVING INTO THE AREA AND CLEARING SKIES LATER TODAY...AS WELL A MOIST SURFACE LAYER AND LIGHT WINDS WILL BE A FAVORABLE ENVIRONMENT FOR FOG DEVELOPMENT. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN. IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND ONLY SHOWERS EXPECTED. HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE PRECIP WILL BE AFTER 00Z SUNDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM EDT FRI APR 17 2015 CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS WOULD SUGGEST PWATS BETWEEN 1.2 AND AOA 1.4 INCHES DURING THIS PERIOD AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM. PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 809 AM EDT FRI APR 17 2015 SOME LOW LEVEL CLOUD COVER ASSOCIATED WITH A WEAK TROUGH MOVING THROUGH FROM THE NORTHWEST WILL BRING SOME 2 TO 3 KFT CEILINGS THROUGH THE AREA BETWEEN 12Z AND 15Z THIS MORNING. AFTERWARD...SKIES WILL BEGIN TO CLEAR OUT BY THE AFTERNOON AND EVENING. HIGH PRESSURE MOVING IN LATER THIS EVENING AND TONIGHT ALONG WITH LIGHT WINDS WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR FOG DEVELOPMENT AND SO HAVE PUT IFR VIS IN ALL THE TAF SITES TONIGHT AFTER 06Z. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHALLENBERGER SHORT TERM...SHALLENBERGER LONG TERM...DJ AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
335 AM EDT FRI APR 17 2015 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN. IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND ONLY SHOWERS EXPECTED. HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE PRECIP WILL BE AFTER 00Z SUNDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 335 AM EDT FRI APR 17 2015 CLOSED UPPER LEVEL LOW THAT HAS BEEN QUASI STATIONARY ACROSS THE DESERT SW WILL FINALLY BEGIN PHASING WITH A NORTHERN STREAM TROUGH AS WE MOVE INTO THE LONG RANGE PERIOD. DIFFLUENCE ALOFT...JET ENERGY... AND SHORTWAVE WILL AID IN DEVELOPING SURFACE LOW PRESSURE ACROSS THE SOUTHERN MISSISSIPPI RIVER VALLEY SATURDAY NIGHT. THIS WILL HELP TO SPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION AS WE MOVE THROUGH THE DAY ON SUNDAY. MODEL SOUNDINGS WOULD SUGGEST PWATS BETWEEN 1.2 AND AOA 1.4 INCHES DURING THIS PERIOD AS COLUMN SATURATES...THEREFORE SOME OF THESE SHOWERS AND STORMS WILL LIKELY BE MODERATE INTENSITY AT TIMES. GIVEN THE VERY WET ANTECEDENT CONDITIONS WE COULD SEE ISOLATED FLOODING THREAT ONCE AGAIN. THIS WILL DEPEND ON THE DEVELOPMENT AND MOVEMENT OF THE LOW PRESSURE THAT DEVELOPS AND MOVES NORTH NORTHEAST SUNDAY AND ALSO ANY CONVECTION THAT DEVELOPS. THIS UPPER LEVEL SYSTEM DOES LOOK TO PHASE WITH THE NORTHERN STREAM TROUGH AS MENTIONED ABOVE AND A CLOSED UPPER LEVEL LOW DEVELOPS ACROSS THE NORTHERN PLAINS. THIS WILL MAKE FOR A TWO PART SYSTEM AS ANOTHER SURFACE LOW DEVELOPS ACROSS THE UPPER MIDWEST SUNDAY EVENING ASSOCIATED WITH A SPOKE OF ENERGY FROM THE CLOSED UPPER LEVEL LOW. THIS LOW PRESSURE WILL DRAG A COLD FRONT ACROSS THE REGION MONDAY AND RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. UP TO THIS POINT WE DO SEE GOOD MODEL AGREEMENT IN REGARDS TO THIS SYSTEM. PASSAGE OF THIS FRONT WILL BREAKDOWN THE PATTERN WITH MORE OF A WESTERLY FLOW AND COOLER AIR USHERED IN BEHIND THE FRONT. AN AREA OF HIGH PRESSURE WILL BUILD TO THE SOUTH WITH HIGHS TEMPS IN THE LOW TO MID 60S AND LOWS IN THE UPPER TO EVEN LOWER 40S TUESDAY INTO WEDNESDAY. MORE DIVERGENCE IN THE MODEL GUIDANCE EXISTS IN THE WEDNESDAY TO THURSDAY TIME FRAME. RIGHT NOW THE GFS AND GFS ENSEMBLE MEAN ARE WETTER THAN THE ECMWF AT THIS POINT. GIVEN THE UNCERTAINTY THAT EXISTS WILL LEAN TOWARD THE MODEL BLEND. THIS WILL BRING SLIGHT POPS ACROSS THE NORTH WEDNESDAY AFTERNOON AND CHANCE TO SLIGHT POPS WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 150 AM EDT FRI APR 17 2015 UPPER AND MID LEVEL CLOUD COVER WILL CONTINUE TO STREAM NORTH INTO THE AREA THROUGH THE NIGHT. SOME WEAK INSTABILITY WILL CONTINUE TO ALLOW SOME LOWER LEVEL CLOUD COVER TO DEVELOP TONIGHT AS WELL AS A FEW SHOWERS. THIS LOOKS TO BE MAINLY ALONG THE SOUTHERN TAF SITES. THE NORTHERN TAF SITES MAY SEE A BREAK IN CLOUD COVER HERE AND THERE. TOWARD DAWN...SOME IFR CLOUD COVER LOOKS TO DEVELOP ACROSS THE AREA AND HAVE PUT THIS INTO THE TAFS. WINDS WILL REMAIN LIGHT THROUGH THE PERIOD. HIGH PRESSURE MOVING IN LATER IN THE TAF PERIOD WILL SHUNT THIS LOWER LEVEL CLOUD COVER TO THE EAST TOWARDS MIDDAY FRIDAY WITH MAINLY CLEAR SKIES OR CIRRUS EXPECTED. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SHALLENBERGER LONG TERM...DJ AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
332 AM EDT FRI APR 17 2015 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 330 AM EDT FRI APR 17 2015 CURRENT CONDITIONS ACROSS THE AREA FEATURE SOME MOIST SOUTHERLY FLOW MOVING INTO KENTUCKY FROM THE SOUTHWEST THIS MORNING. AT THIS TIME...WEAK SURFACE HIGH PRESSURE CENTERED OVER MI IS POISED TO SLOWLY CREEP SOUTHEAST. IN THIS AREA OVER THE LOWER GREAT LAKES...A BIT OF CLEARING MAY MAKE IT INTO EAST KENTUCKY THIS MORNING. THIS COMBINED WITH THE MOISTURE PRESENT OVER THE AREA MAY RESULT IN SOME DENSE FOG DEVELOPMENT TOWARDS DAWN. AT THIS POINT...IT LOOKS LIKE A TOUGH CALL WITH CLOUD COVER CONTINUING TO STREAM IN FROM THE SOUTHWEST. HAVE PUT PATCHY FOG IN THE FORECAST TO COVER THIS BUT WILL ALSO MONITOR FOG DEVELOPMENT TOWARDS DAWN. IN ADDITION TO THIS...A WEAK REMNANT TROUGH SLIDING EAST AHEAD OF HIGH PRESSURE MAY BE ENOUGH TO SPAWN A FEW SHOWERS. HI RES MODELS SUCH AS THE HRRR DO HINT AT THIS INTO THE DAY AS THIS TROUGH SLOWLY SLIDES THROUGH. WITH NO REAL SURFACE FEATURE THIS ACTIVITY IS TIED TO...WILL GO WITH SLIGHT CHANCE POPS THROUGH MIDDAY AND ONLY SHOWERS EXPECTED. HEADING INTO TONIGHT...MENTIONED HIGH PRESSURE WILL MOVE INTO THE AREA TONIGHT. SOME BREAKS IN THE CLOUD COVER IS EXPECTED...ESPECIALLY OVER THE NORTH WHERE SOME CLEAR SKIES LOOK TO DEVELOP. THIS MAY POSE AS A BETTER FOG SET UP AND MAY NEED TO MENTION THIS IN THE HWO. BY SATURDAY...A CLOSED UPPER LOW EJECTS INTO THE CENTRAL PLAINS...AND A SHORTWAVE MOVES OUT OF THE BASE OF THE LOW...CROSSING THE LOWER MS RIVER VALLEY AND NORTHEAST INTO THE OH AND TN VALLEYS. SURFACE LOW PRESSURE AND A DEVELOPING WARM FRONT WILL BRING A SURGE OF MOIST AIR INTO EAST KENTUCKY WITH A SLIGHT CHANCE POPS MAKING MAKING IT INTO POINTS SOUTH OF THE HAL ROGERS PARKWAY BY SATURDAY AFTERNOON. MODELS WITH THIS FEATURE HAVE BEEN PRETTY CONSISTENT AND THE BEST CHANCE OF MEASURABLE PRECIPWILL BE AFTER 00Z SUNDAY. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM EDT FRI APR 17 2015 THE LONG TERM DISCUSSION WILL BE ISSUED SHORTLY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 150 AM EDT FRI APR 17 2015 UPPER AND MID LEVEL CLOUD COVER WILL CONTINUE TO STREAM NORTH INTO THE AREA THROUGH THE NIGHT. SOME WEAK INSTABILITY WILL CONTINUE TO ALLOW SOME LOWER LEVEL CLOUD COVER TO DEVELOP TONIGHT AS WELL AS A FEW SHOWERS. THIS LOOKS TO BE MAINLY ALONG THE SOUTHERN TAF SITES. THE NORTHERN TAF SITES MAY SEE A BREAK IN CLOUD COVER HERE AND THERE. TOWARD DAWN...SOME IFR CLOUD COVER LOOKS TO DEVELOP ACROSS THE AREA AND HAVE PUT THIS INTO THE TAFS. WINDS WILL REMAIN LIGHT THROUGH THE PERIOD. HIGH PRESSURE MOVING IN LATER IN THE TAF PERIOD WILL SHUNT THIS LOWER LEVEL CLOUD COVER TO THE EAST TOWARDS MIDDAY FRIDAY WITH MAINLY CLEAR SKIES OR CIRRUS EXPECTED. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SHALLENBERGER LONG TERM...DJ AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
151 AM EDT FRI APR 17 2015 .UPDATE... ISSUED AT 150 AM EDT FRI APR 17 2015 ISSUED AN UPDATE TO INPUT THE LATEST TEMPS AND DEW POINTS ACROSS THE AREA. PRECIP HAS NOT REDEVELOPED INTO THE AREA YET BUT EVIDENCE OF A FEW VERY SMALL SHOWERS POPPING JUST NORTH OF THE OH RIVER WILL JUST BE ENOUGH EVIDENCE OF WEAK INSTABILITY TO LEAVE POPS IN FOR SLIGHT CHANCE SHOWERS THROUGH DAWN. A NEW ZFP WILL NOT BE NEEDED WITH THIS UPDATE. UPDATE ISSUED AT 1004 PM EDT THU APR 16 2015 PRECIP HAS DIED OUT OVER THE JKL FORECAST AREA FOR THE TIME BEING. THERE WERE SHOWERS OCCURRING FROM WESTERN KY TO SOUTHWESTERN OH. SHORT RANGE MODELS SUGGEST THIS AREA OF SHOWERS WILL SAG SOUTHEAST AND ADDITIONAL SHOWER DEVELOPMENT WILL ALSO OCCUR OVER EASTERN KY A LITTLE BEFORE DAWN. HAVE USED 20-30 PERCENT POP TO ACCOUNT FOR THIS. MODELS ALSO SHOW A SMALL RESURGENCE OF SHOWERS LATE FRIDAY AFTER SOME DESTABILIZATION OCCURS. IF IT OCCURS...THINK THE ACTIVITY WOULD BE VERY ISOLATED. FORECAST SOUNDINGS SHOW VERY DRY AIR ALOFT THAT THE CONVECTIVE CURRENTS WOULD BE RISING INTO. WITHOUT A STRONG FOCUS/FORCING MECHANISM...DRY AIR ENTRAINMENT COULD BE THE DEMISE OF WHAT WOULD OTHERWISE BE MORE PLENTIFUL ACTIVITY. UPDATE ISSUED AT 615 PM EDT THU APR 16 2015 UPDATED POPS FROM FRIDAY INTO SATURDAY. LATEST MODEL RUNS SUGGEST THE TIME FRAME FROM LATE FRIDAY THROUGH SATURDAY WILL LIKELY BE DRY. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 306 PM EDT THU APR 16 2015 WITH THE LATEST RUN OF THE HRRR MODEL BEING A BIT OFF WITH ITS HANDLING OF TODAYS CONVECTION...THE NAM12 WAS MODEL OF CHOICE FOR THE SHORT TERM PORTION OF THE FORECAST. SHOWERS AND STORMS THAT HAVE BEEN MOVING ACROSS EASTERN KENTUCKY THROUGHOUT THE DAY ARE CURRENTLY AFFECTING THE NORTHEASTERN PORTION OF THE THE AREA. THIS ACTIVITY IS EXPECTED TO MOVE ON OUT OF THE AREA IN THE NEXT FEW HOURS. CURRENT RADAR INDICATES THAT ISOLATED TO SCATTERED SHOWERS AND STORMS WILL CONTINUE TO MOVE INTO THE AREA FROM THE SOUTHWEST DURING THE REMAINDER OF THE AFTERNOON AND EVENING HOURS. ONLY ISOLATED ACTIVITY...IF THAT...WILL BE LEFT OVER FOR THE OVERNIGHT HOURS. SHOWERS AND STORMS WILL BE POSSIBLE DURING THE DAY ON FRIDAY...AS A WEAK FRONTAL BOUNDARY MOVES IN FROM THE WEST. WEAK DISTURBANCES AHEAD OF THIS FRONT MAY ALSO KICK OFF SHOWERS AND STORMS...BUT WITH A LACK OF INSTABILITY AND STRONG LIFT...IT APPEARS THAT THE COVERAGE OF PRECIPITATION WILL BE SPARSE. BASED ON THE LATEST MODEL DATA...THERE SHOULD BE LULL IN THE ACTION FROM LATE FRIDAY AFTERNOON THROUGH EARLY SATURDAY MORNING...AS A WEAK RIDGE OF HIGH PRESSURE BRIEFLY SETTLES OVER THE AREA. TEMPERATURES DURING THE PERIOD WILL BE WELL ABOVE NORMAL FOR THIS TIME OF YEAR...WITH HIGHS ON FRIDAY MAXING OUT IN THE 70S...AND OVERNIGHT LOWS TONIGHT AND FRIDAY NIGHT BOTTOMING OUT IN THE LOW TO MID 50S AREA WIDE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 340 PM EDT THU APR 16 2015 MAIN CONCERN DURING THE EXTENDED PERIOD IS FOCUSED ON A CUT OFF LOW CURRENTLY OVER THE FOUR CORNERS REGION. THIS LOW IS PROGGED TO PUSH SLOWLY EWD EARLY SATURDAY BEFORE ITS ENERGY GETS INGESTED AND HELPS DEEPEN A NORTHERN STREAM TROUGH. THIS TROUGH WILL MOVE ALONG THE US/CANADIAN BORDER UNTIL THE CLOSED LOW ENERGY PHASES WITH IT AND MOVES EAST. IN ADDITION TO THE UPPER LEVEL TROUGH...A SFC LOW IS FORECASTED TO DEVELOP SATURDAY NIGHT OVER THE PLAINS AND AHEAD OF IT...A STRONG SURGE OF GULF MOISTURE RETURNS TO THE OH AND TN VALLEYS. PW VALUES UP TO 1.4 INCHES ARE EXPECTED WITH THIS NEW SURGE OF MOISTURE....WHICH ARE WELL ABOVE AVERAGE. THERE WILL BE SOME MODERATE INSTABILITY AS WELL. THIS SYSTEM SHOULD PUSH OUT OF KY BY MONDAY NIGHT. ON TUESDAY...A LOW THAT IS NOW CUT OFF IN THE NORTHERN STREAM WILL UNDULATE OVER THE GREAT LAKES REGION THROUGH THURSDAY WITH PIECES OF ENERGY WRAPPING AROUND IT. HOWEVER...THIS SHOULDN/T CAUSE ANY ISSUES FOR KENTUCKY AS THE ENERGY APPEARS TO STAY FURTHER NORTH UNTIL THURSDAY WHEN THE LOW STARTS SAGGING SOUTHEASTWARD. AT THE SFC...SATURDAY WILL BE MAINLY DRY AND WARM UNTIL LATE AFTERNOON WHEN CHANCES FOR PRECIP BEGIN INCREASING. THE BULK OF THE RAINFALL WILL FALL SUNDAY INTO MONDAY WHERE AT LEAST AN INCH OF LIQUID IS LIKELY ACROSS EASTERN KENTUCKY. THERE IS ALSO A CHANCE FOR THUNDERSTORMS DURING THIS TIME GIVEN THE MOIST AIR MASS IN PLACE AND PLENTY OF SFC/UPPER LEVEL DYNAMICS. AS THIS SYSTEM EXITS THE AREA MONDAY NIGHT...THINGS WILL DRY OUT AND EASTERN KENTUCKY WILL GET A REPRIEVE FROM PRECIPITATION TUESDAY AND WEDNESDAY. TEMPERATURES DURING THIS TIME WILL BE A BIT BELOW NORMAL IF NOT RIGHT AT SEASONABLE LEVELS. RAIN CHANCES RETURN ON THURSDAY AS THE LOW SAGS SOUTHEASTWARD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 150 AM EDT FRI APR 17 2015 UPPER AND MID LEVEL CLOUD COVER WILL CONTINUE TO STREAM NORTH INTO THE AREA THROUGH THE NIGHT. SOME WEAK INSTABILITY WILL CONTINUE TO ALLOW SOME LOWER LEVEL CLOUD COVER TO DEVELOP TONIGHT AS WELL AS A FEW SHOWERS. THIS LOOKS TO BE MAINLY ALONG THE SOUTHERN TAF SITES. THE NORTHERN TAF SITES MAY SEE A BREAK IN CLOUD COVER HERE AND THERE. TOWARD DAWN...SOME IFR CLOUD COVER LOOKS TO DEVELOP ACROSS THE AREA AND HAVE PUT THIS INTO THE TAFS. WINDS WILL REMAIN LIGHT THROUGH THE PERIOD. HIGH PRESSURE MOVING IN LATER IN THE TAF PERIOD WILL SHUNT THIS LOWER LEVEL CLOUD COVER TO THE EAST TOWARDS MIDDAY FRIDAY WITH MAINLY CLEAR SKIES OR CIRRUS EXPECTED. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHALLENBERGER SHORT TERM...AR LONG TERM...JVM AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
925 PM CDT SAT APR 18 2015 .DISCUSSION... MAIN WX CONCERN IS THE MCS OVER C AND N TX...MOVING E. RADAR STILL SHOWS FAIRLY SOLID SQUALL LINE BETWEEN WHILE SOME WEAKENING IS EXPECTED TO CONTINUE...LATEST NAM12 & HRRR SUGGEST IT CONTINUING E THE NEXT SEVERAL HOURS...AFFECTING INLAND SE TX/C LA BETWEEN 06-09Z. THUS...HAVE INCREASED THE POPS AND QPF ACROSS THESE AREAS FOR THE EVENING UPDATE. FOR THE REMAINDER OF THE AREA...20% CONTINUES FOR ANY ISO SHRA/TSRA AHEAD OF THIS SYSTEM. DML && .PREV DISCUSSION... /ISSUED 734 PM CDT SAT APR 18 2015/ DISCUSSION... FOR THE 00Z TAF PACKAGE. AVIATION... MAINLY ISOLATED TO SCATTERED SHOWERS ACROSS PARTS OF EAST AND SOUTH CENTRAL LOUISIANA EARLY THIS EVENING. LATEST HRRR DEPICTS CONVECTIVE COMPLEX OVER CENTRAL TEXAS REACHING PERHAPS AS FAR AS JUST EAST OF THE SABINE RIVER SOMETIME AFTER MIDNIGHT BEFORE DISSIPATING. WILL CONTINUE TO MONITOR RADAR/MODEL TRENDS THROUGH THE EVENING. OTHERWISE...A MIX OF MVFR/VFR CIGS ACROSS THE AREA IS EXPECTED TO LOWER INTO MVFR/IFR AS LIGHT FOG AND/OR LOWER CIGS DEVELOP DURING THE OVERNIGHT HOURS. IMPROVEMENT TO VFR IS EXPECTED ON SUNDAY AS DRIER AIR MOVES IN FROM THE WEST. 13 PREV DISCUSSION... /ISSUED 421 PM CDT SAT APR 18 2015/ SYNOPSIS... LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX. THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA. DISCUSSION... OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW. THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE AHEAD AND CANCELLED THE FLASH FLOOD WATCH. DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN. HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER OF COUNTIES AND PARISHES. DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS OVER THE AREA THURSDAY AND FRIDAY. MARINE... LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST. && .PRELIMINARY POINT TEMPS/POPS... AEX 63 83 60 76 / 30 30 30 10 LCH 64 82 63 79 / 20 20 20 10 LFT 65 84 64 79 / 30 20 20 10 BPT 64 82 63 79 / 20 20 20 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ PUBLIC...04
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
734 PM CDT SAT APR 18 2015 .DISCUSSION... FOR THE 00Z TAF PACKAGE. && .AVIATION... MAINLY ISOLATED TO SCATTERED SHOWERS ACROSS PARTS OF EAST AND SOUTH CENTRAL LOUISIANA EARLY THIS EVENING. LATEST HRRR DEPICTS CONVECTIVE COMPLEX OVER CENTRAL TEXAS REACHING PERHAPS AS FAR AS JUST EAST OF THE SABINE RIVER SOMETIME AFTER MIDNIGHT BEFORE DISSIPATING. WILL CONTINUE TO MONITOR RADAR/MODEL TRENDS THROUGH THE EVENING. OTHERWISE...A MIX OF MVFR/VFR CIGS ACROSS THE AREA IS EXPECTED TO LOWER INTO MVFR/IFR AS LIGHT FOG AND/OR LOWER CIGS DEVELOP DURING THE OVERNIGHT HOURS. IMPROVEMENT TO VFR IS EXPECTED ON SUNDAY AS DRIER AIR MOVES IN FROM THE WEST. 13 && .PREV DISCUSSION... /ISSUED 421 PM CDT SAT APR 18 2015/ SYNOPSIS... LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX. THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA. DISCUSSION... OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW. THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE AHEAD AND CANCELLED THE FLASH FLOOD WATCH. DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN. HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER OF COUNTIES AND PARISHES. DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS OVER THE AREA THURSDAY AND FRIDAY. MARINE... LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST. && .PRELIMINARY POINT TEMPS/POPS... AEX 63 83 60 76 / 40 20 30 10 LCH 64 82 63 79 / 30 10 20 10 LFT 65 84 64 79 / 50 20 20 10 BPT 64 82 63 79 / 30 20 20 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ AVIATION...13
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
151 PM CDT FRI APR 17 2015 .DISCUSSION... 17/18Z TAF ISSUANCE. && .AVIATION... MUCH IMPROVED CONDITIONS TODAY COMPARED TO YESTERDAY. MAINLY SCT/BKN CUMULUS OVER THE REGION...WITH PREVAILING VFR AND OCNL MVFR CIGS AT TAF SITES EARLY THIS AFTN. THESE CONDITIONS WILL CONTINUE INTO THE EVENING...WITH CONDITIONS AGAIN DETERIORATING OVERNIGHT FROM WEST TO EAST AS THE NEXT DISTURBANCE APPROACHES. CIGS WILL LOWER TO LOW END MVFR OR IFR AFTER 06Z...WITH SHRA/TSRA DEVELOPING. CONVECTION WILL BECOME MORE WIDESPREAD THROUGH SATURDAY MORNING...WITH GUSTY WINDS AND HEAVY RAIN EXPECTED WITHIN SOME OF THE STRONGER STORMS. 24 && .PREV DISCUSSION... /ISSUED 1050 AM CDT FRI APR 17 2015/ DISCUSSION... AFTER A FUN DAY YESTERDAY...LOCAL 88DS ARE REFRESHINGLY QUIET THIS MORNING WITH MAINLY JUST RAINS ASSOCIATED WITH A DEPARTING DISTURBANCE ALOFT EXITING THE ERN COASTAL WATERS AND POSSIBLY BRUSHING LOWER ACADIANA. 12Z KLCH SOUNDING SHOWED A MUCH DRIER AIRMASS IN PLACE OVER THE REGION TODAY...WHILE THE MODIFIED SOUNDING SHOWED SIMILAR INSTABILITY TO THURSDAY. PLAYING TO OUR ADVANTAGE TODAY IS A RELATIVE LACK OF APPROACHING DISTURBANCES ROUNDING THE UPPER LOW OVER THE FOUR CORNERS REGION. HOWEVER GIVEN THAT WE ARE STILL REASONABLY MOIST AND FAIRLY UNSTABLE...DAYTIME HEATING OR PERHAPS SOME LINGERING BOUNDARIES FROM EARLIER CONVECTION COULD STILL SPARK SOME SHOWERS AND STORMS ESPECIALLY THIS AFTERNOON. DESPITE WHAT LOOKS LIKE A LACK OF PRECIP TODAY...STILL EXPECTING ANOTHER HEAVY RAINFALL EVENT BEGINNING TONIGHT AND RUNNING INTO SATURDAY. GIVEN THE FLOODING WHICH OCCURRED YESTERDAY AND THE SATURATED GROUNDS LEFT BEHIND FROM ALL THE RAIN...EXTENDED THE INHERITED FLASH FLOOD WATCH THROUGH LATE TOMORROW AFTERNOON. ELSEWHERE JUST TWEAKED GRIDS/ZONES BASED ON LATEST OBS/TRENDS... UPDATE ALREADY OUT. 25 PREV DISCUSSION... /ISSUED 616 AM CDT FRI APR 17 2015/ AVIATION...SINCE MIDNIGHT CONVECTIVE ACTIVITY HAS DECREASED SIGNIFICANTLY. RADAR NOW SHOWING JUST A FEW SHOWERS AND THUNDERSTORMS AND THESE OFFSHORE OVER THE NEAR COASTAL WATERS. TODAY LOOKS TO WITH MUCH LESS CONVECTION OVER THE AREA AS SOME SHARPLY DRIER MID LEVEL AIR ADVECTS INTO THE REGION. MODELS SUGGESTING A RAMPING UP OF PRECIP OVERNIGHT AS ANOTHER UPPER LEVEL DISTURBANCE APPROACHES. ALTOCU CLOUDS AT AROUND 10KT FT CURRENTLY OVER AREA. WILL SEE LOWER CLOUDS DEVELOP AS THE MORNING PROGRESSES BUT WILL MAINTAIN THESE WITHIN VFR. 25 PREV DISCUSSION... /ISSUED 335 AM CDT FRI APR 17 2015/ DISCUSSION...POPS AND HEAVY RAIN WILL BE THE MAIN FORECAST ISSUES OVER THE NEXT 48 HOURS. WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY YESTERDAY AND OVERNIGHT WAS BEGINNING TO DECREASE AS OF 08Z. THE LATEST HRRR CONFIRMS THIS WITH ACTIVITY DECREASING SIGNIFICANT LATER THIS MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA. WILL CONTINUE WITH FFA FOR NOW...BUT MAY CANCEL EARLY IF WEAKENING TREND CONTINUES. WILL TAPER POPS TO MID RANGE FOR THIS AFTERNOON. MODELS HAVE BEEN CONSISTENT IN LIFTING UPPER TROUGH NE THROUGH THE WEEKEND. ALSO...APPEARS THAT NEXT ROUND OF SHOWERS AND THUNDERSTORMS WILL BEGIN LATE TONIGHT AND BECOME MORE WIDESPREAD ON SATURDAY. WILL LIKELY NEED TO REISSUE FFA FOR TONIGHT AND SATURDAY. AFTER SATURDAY...A MUCH NEEDED PATTERN CHANGE IS FORECASTED. WEAK UPPER RIDGE SHOULD DEVELOP OVER THE GULF COAST STATES. A FRONTAL BOUNDARY SHOULD MOVE THROUGH THE AREA BY SUNDAY NIGHT AND THIS WILL LIKELY BRING DRY WEATHER FOR EARLY NEXT WEEK. FRONT IS FORECASTED TO STALL OVER THE GULF AND RETURN NORTH LATE IN THE WEEK. AT THIS TIME...WILL KEEP LOW POPS IN THE FORECAST ALTHOUGH LATEST MODELS ARE SHOWING A DEEPER MOISTURE PROFILE THIS CYCLE. MARINE...PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH THE EARLY PART OF THE WEEKEND. OTHERWISE HIGH PRESSURE OVER THE EASTERN GULF AND LOW PRESSURE OVER WEST TEXAS WILL MAINTAIN ONSHORE FLOW THROUGH SUNDAY. MODELS CONTINUE TO BRING FRONT INTO THE NORTHERN GULF SUNDAY NIGHT ALLOWING FOR A BRIEF PERIOD OF OFFSHORE FLOW. WEAK TO MODERATE EASTERLY FLOW IS ANTICIPATED FOR EARLY NEXT WEEK AS HIGH PRESSURE SETTLES OVER THE SE U.S. AP && .PRELIMINARY POINT TEMPS/POPS... AEX 81 66 77 62 / 30 70 80 40 LCH 82 67 77 64 / 40 70 80 40 LFT 81 69 78 65 / 40 60 90 40 BPT 82 67 79 64 / 40 70 70 40 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR LAZ027>033- 041>045-052>055-073-074. TX...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR TXZ180-201-215- 216-259>262. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1050 AM CDT FRI APR 17 2015 .DISCUSSION... AFTER A FUN DAY YESTERDAY...LOCAL 88DS ARE REFRESHINGLY QUIET THIS MORNING WITH MAINLY JUST RAINS ASSOCIATED WITH A DEPARTING DISTURBANCE ALOFT EXITING THE ERN COASTAL WATERS AND POSSIBLY BRUSHING LOWER ACADIANA. 12Z KLCH SOUNDING SHOWED A MUCH DRIER AIRMASS IN PLACE OVER THE REGION TODAY...WHILE THE MODIFIED SOUNDING SHOWED SIMILAR INSTABILITY TO THURSDAY. PLAYING TO OUR ADVANTAGE TODAY IS A RELATIVE LACK OF APPROACHING DISTURBANCES ROUNDING THE UPPER LOW OVER THE FOUR CORNERS REGION. HOWEVER GIVEN THAT WE ARE STILL REASONABLY MOIST AND FAIRLY UNSTABLE...DAYTIME HEATING OR PERHAPS SOME LINGERING BOUNDARIES FROM EARLIER CONVECTION COULD STILL SPARK SOME SHOWERS AND STORMS ESPECIALLY THIS AFTERNOON. DESPITE WHAT LOOKS LIKE A LACK OF PRECIP TODAY...STILL EXPECTING ANOTHER HEAVY RAINFALL EVENT BEGINNING TONIGHT AND RUNNING INTO SATURDAY. GIVEN THE FLOODING WHICH OCCURRED YESTERDAY AND THE SATURATED GROUNDS LEFT BEHIND FROM ALL THE RAIN...EXTENDED THE INHERITED FLASH FLOOD WATCH THROUGH LATE TOMORROW AFTERNOON. ELSEWHERE JUST TWEAKED GRIDS/ZONES BASED ON LATEST OBS/TRENDS... UPDATE ALREADY OUT. 25 && .PREV DISCUSSION... /ISSUED 616 AM CDT FRI APR 17 2015/ AVIATION...SINCE MIDNIGHT CONVECTIVE ACTIVITY HAS DECREASED SIGNIFICANTLY. RADAR NOW SHOWING JUST A FEW SHOWERS AND THUNDERSTORMS AND THESE OFFSHORE OVER THE NEAR COASTAL WATERS. TODAY LOOKS TO WITH MUCH LESS CONVECTION OVER THE AREA AS SOME SHARPLY DRIER MID LEVEL AIR ADVECTS INTO THE REGION. MODELS SUGGESTING A RAMPING UP OF PRECIP OVERNIGHT AS ANOTHER UPPER LEVEL DISTURBANCE APPROACHES. ALTOCU CLOUDS AT AROUND 10KT FT CURRENTLY OVER AREA. WILL SEE LOWER CLOUDS DEVELOP AS THE MORNING PROGRESSES BUT WILL MAINTAIN THESE WITHIN VFR. PREV DISCUSSION... /ISSUED 335 AM CDT FRI APR 17 2015/ DISCUSSION...POPS AND HEAVY RAIN WILL BE THE MAIN FORECAST ISSUES OVER THE NEXT 48 HOURS. WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY YESTERDAY AND OVERNIGHT WAS BEGINNING TO DECREASE AS OF 08Z. THE LATEST HRRR CONFIRMS THIS WITH ACTIVITY DECREASING SIGNIFICANT LATER THIS MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA. WILL CONTINUE WITH FFA FOR NOW...BUT MAY CANCEL EARLY IF WEAKENING TREND CONTINUES. WILL TAPER POPS TO MID RANGE FOR THIS AFTERNOON. MODELS HAVE BEEN CONSISTENT IN LIFTING UPPER TROUGH NE THROUGH THE WEEKEND. ALSO...APPEARS THAT NEXT ROUND OF SHOWERS AND THUNDERSTORMS WILL BEGIN LATE TONIGHT AND BECOME MORE WIDESPREAD ON SATURDAY. WILL LIKELY NEED TO REISSUE FFA FOR TONIGHT AND SATURDAY. AFTER SATURDAY...A MUCH NEEDED PATTERN CHANGE IS FORECASTED. WEAK UPPER RIDGE SHOULD DEVELOP OVER THE GULF COAST STATES. A FRONTAL BOUNDARY SHOULD MOVE THROUGH THE AREA BY SUNDAY NIGHT AND THIS WILL LIKELY BRING DRY WEATHER FOR EARLY NEXT WEEK. FRONT IS FORECASTED TO STALL OVER THE GULF AND RETURN NORTH LATE IN THE WEEK. AT THIS TIME...WILL KEEP LOW POPS IN THE FORECAST ALTHOUGH LATEST MODELS ARE SHOWING A DEEPER MOISTURE PROFILE THIS CYCLE. MARINE...PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH THE EARLY PART OF THE WEEKEND. OTHERWISE HIGH PRESSURE OVER THE EASTERN GULF AND LOW PRESSURE OVER WEST TEXAS WILL MAINTAIN ONSHORE FLOW THROUGH SUNDAY. MODELS CONTINUE TO BRING FRONT INTO THE NORTHERN GULF SUNDAY NIGHT ALLOWING FOR A BRIEF PERIOD OF OFFSHORE FLOW. WEAK TO MODERATE EASTERLY FLOW IS ANTICIPATED FOR EARLY NEXT WEEK AS HIGH PRESSURE SETTLES OVER THE SE U.S. && .PRELIMINARY POINT TEMPS/POPS... AEX 81 66 77 62 / 30 70 80 40 LCH 82 67 77 64 / 40 70 80 40 LFT 81 69 78 65 / 40 60 90 40 BPT 82 67 79 64 / 40 70 70 40 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR LAZ027>033- 041>045-052>055-073-074. TX...FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR TXZ180-201-215- 216-259>262. GM...NONE. && $$ PUBLIC...04
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
616 AM CDT FRI APR 17 2015 .AVIATION...SINCE MIDNIGHT CONVECTIVE ACTIVITY HAS DECREASED SIGNIFICANTLY. RADAR NOW SHOWING JUST A FEW SHOWERS AND THUNDERSTORMS AND THESE OFFSHORE OVER THE NEAR COASTAL WATERS. TODAY LOOKS TO WITH MUCH LESS CONVECTION OVER THE AREA AS SOME SHARPLY DRIER MID LEVEL AIR ADVECTS INTO THE REGION. MODELS SUGGESTING A RAMPING UP OF PRECIP OVERNIGHT AS ANOTHER UPPER LEVEL DISTURBANCE APPROACHES. ALTOCU CLOUDS AT AROUND 10KT FT CURRENTLY OVER AREA. WILL SEE LOWER CLOUDS DEVELOP AS THE MORNING PROGRESSES BUT WILL MAINTAIN THESE WITHIN VFR. && .PREV DISCUSSION... /ISSUED 335 AM CDT FRI APR 17 2015/ DISCUSSION...POPS AND HEAVY RAIN WILL BE THE MAIN FORECAST ISSUES OVER THE NEXT 48 HOURS. WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY YESTERDAY AND OVERNIGHT WAS BEGINNING TO DECREASE AS OF 08Z. THE LATEST HRRR CONFIRMS THIS WITH ACTIVITY DECREASING SIGNIFICANT LATER THIS MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA. WILL CONTINUE WITH FFA FOR NOW...BUT MAY CANCEL EARLY IF WEAKENING TREND CONTINUES. WILL TAPER POPS TO MID RANGE FOR THIS AFTERNOON. MODELS HAVE BEEN CONSISTENT IN LIFTING UPPER TROUGH NE THROUGH THE WEEKEND. ALSO...APPEARS THAT NEXT ROUND OF SHOWERS AND THUNDERSTORMS WILL BEGIN LATE TONIGHT AND BECOME MORE WIDESPREAD ON SATURDAY. WILL LIKELY NEED TO REISSUE FFA FOR TONIGHT AND SATURDAY. AFTER SATURDAY...A MUCH NEEDED PATTERN CHANGE IS FORECASTED. WEAK UPPER RIDGE SHOULD DEVELOP OVER THE GULF COAST STATES. A FRONTAL BOUNDARY SHOULD MOVE THROUGH THE AREA BY SUNDAY NIGHT AND THIS WILL LIKELY BRING DRY WEATHER FOR EARLY NEXT WEEK. FRONT IS FORECASTED TO STALL OVER THE GULF AND RETURN NORTH LATE IN THE WEEK. AT THIS TIME...WILL KEEP LOW POPS IN THE FORECAST ALTHOUGH LATEST MODELS ARE SHOWING A DEEPER MOISTURE PROFILE THIS CYCLE. MARINE...PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH THE EARLY PART OF THE WEEKEND. OTHERWISE HIGH PRESSURE OVER THE EASTERN GULF AND LOW PRESSURE OVER WEST TEXAS WILL MAINTAIN ONSHORE FLOW THROUGH SUNDAY. MODELS CONTINUE TO BRING FRONT INTO THE NORTHERN GULF SUNDAY NIGHT ALLOWING FOR A BRIEF PERIOD OF OFFSHORE FLOW. WEAK TO MODERATE EASTERLY FLOW IS ANTICIPATED FOR EARLY NEXT WEEK AS HIGH PRESSURE SETTLES OVER THE SE U.S. && .PRELIMINARY POINT TEMPS/POPS... AEX 80 66 77 62 / 60 70 80 40 LCH 81 67 77 64 / 70 70 80 40 LFT 80 69 78 65 / 70 60 90 40 BPT 81 67 79 64 / 70 70 70 40 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR LAZ027>033- 041>045-052>055-073-074. TX...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR TXZ180-201- 215-216-259>262. GM...NONE. && $$ AVIATION...23
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1036 AM EDT FRI APR 17 2015 .SYNOPSIS... A SURFACE TROUGH WILL PASS THROUGH THE REGION TODAY. HIGH PRESSURE WILL RETURN FOR SATURDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY AND A WARM FRONT WILL MOVE INTO THE AREA SUNDAY NIGHT INTO MONDAY. A COLD FRONT WILL PASS THROUGH LATE MONDAY INTO MONDAY NIGHT BEFORE HIGH PRESSURE RETURNS FOR THE MIDDLE PORTION OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... 14Z MSAS AND SURFACE ANALYSIS INDICATES SURFACE TROUGH HAS REACHED WRN PA AND FAR EASTERN OH. THIS TROUGH WILL MOVE THROUGH THE FORECAST AREA THIS AFTN. SOME SCATTERED AREAS OF LIGHT RAIN SHOWERS AHEAD OF THIS BOUNDARY HAVE MOVED INTO WESTERN MD AND EASTERN WV. JUST TO THE EAST...SKIES HAVE CLEARED OVER MOST AREAS ALONG AND EAST OF THE SHENANDOAH VALLEY...ALLOWING TEMPS TO REACH WELL INTO THE 60S. TEMPS SHOULD RISE INTO THE L-M 70S BY AFTERNOON. NW FLOW WILL DRAW IN COLD DRY AIR ALOFT TODAY. THIS WILL CAUSE LAPSE RATES TO INCREASE. SHOWERS ARE EXPECTED TO FORM ALONG THE SFC TROUGH BY EARLY AFTERNOON. LATEST HRRR GUIDANCE SHOWS CONVECTIVE SHOWERS INCREASING IN COVERAGE BY EARLY AFTN IN THE SHENANDOAH VALLEY AND SPREADING EWD TOWARD THE BALTIMORE/WASHINGTON METRO AREAS. WARMER SFC TEMPS AND DECENT BOUNDARY LAYER MIXING WILL ALLOW SEVERAL HUNDRED J/KG OF CAPE. A FEW THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND EARLY EVENING. CLEARING IS EXPECTED BEHIND THE SFC TROUGH INTO THE EVENING. HIGH PRESSURE WILL MOVE INTO THE REGION TONIGHT AND PERSIST SATURDAY. FCST MIN TEMPS INT HE 50S EXPECTED TONIGHT. FULL SUNSHINE WILL ALLOW TEMPS TO RISE INTO THE UPPER 70S TO NEAR 80 IN THE METROS SATURDAY. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... REGION REMAINS ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE CENTERED JUST NORTH OF THE GREAT LAKES. RIDGING BUILDS IN ALOFT...WITH THE RIDGE AXIS SHIFTING ACROSS THE MID ATLANTIC BY SUN MORNING. OVERALL PATTERN WILL KEEP THE AREA DRY. CLOUDS WILL BEGIN TO INCREASE FROM THE SOUTHWEST AHEAD OF THE NEXT FRONTAL SYSTEM. WINDS WILL LIGHTEN AND BECOME NE OVERNIGHT AS THE HIGH BUILDS SOUTH. && .LONG TERM /MONDAY THROUGH THURSDAY/... 00Z MODEL SUITE CONTINUING WITH A SLOWER PROGRESSION OF THE NEXT FRONTAL SYSTEM...AND THE ARRIVAL TIMING OF THE PCPN. RIDGE AXIS SHIFTS EAST DURING THE DAY SUNDAY AS A DEEPENING CLOSED LOW OVER THE NORTHERN PLAINS BUILDS EAST. BROAD LOW PRESSURE AT THE SFC OVER THE CENTRAL PLAINS BECOMES ORGANIZED DURING HE DAY AS WELL AS IT MOVES INTO THE WESTERN GREAT LAKES...GRADUALLY LIFTING THE ASSOCIATED WARM FRONT TO THE NORTH AND INTO THE MID ATLANTIC. GENERAL CONSENSUS AMONGST THE MODELS KEEPS THE WARM FRONT AT OR JUST SOUTH OF THE VA/NC BORDER THRU SUN NIGHT...WITH PCPN OCCURRING SUN-SUN NIGHT AS A RESULT OF DYNAMIC FORCING ALOFT WITH MULTIPLE MID LVL SHORTWAVES AND STRENGTHENING LLJ AND 250MB JET. PWATS INCRSG TO BETWEEN 1.2-1.4 IN...WHICH COULD RESULT IN PERIODS OF MODERATE TO HEAVY RAIN. SOME UNCERTAINTY STILL EXISTS WITH PCPN TIMING AND TSTM DEVELOPMENT ON MONDAY. WARM FRONT LOOKS TO BE NEAR THE VA/NC BORDER EARLY MONDAY...THEN GRADUALLY LIFTING NORTH DURING THE DAY. HOW QUICKLY IT CAN CLEAR THE CWA AND WARM SECTOR THE AREA WILL AFFECT THE EXTENT OF TSTM DEVELOPMENT...AND AS SUCH WILL CONTINUE TO MENTION SLIGHT CHC T FOR MOST OF THE AREA NOW...AND CHC OVER CENTRAL VA WHERE THE BEST DAYTIME HEATING SHOULD OCCUR. KEPT NORTHEASTERN MD OUT OF THE THUNDER MENTION FOR NOW WITH COOLER TEMPS EXPECTED. IN ADDITION...THINKING THERE SHOULD BE TWO ROUNDS OF PCPN...THE INITIAL SUN NIGHT...WITH A BREAK AT SOME POINT MONDAY WITH THE NEXT ROUND MOVING IN AHEAD OF THE APPROACHING COLD FRONT. THE COLD FRONT PUSHES THROUGH MONDAY NIGHT...WITH PCPN CLEARING TO THE EAST BY EARLY TUES MORNING. SFC HIGH PRESSURE BUILDS IN FROM THE SOUTH IN THE WAKE OF THE FRONT THRU WED...QUICKLY PROGRESSING OFFSHORE BY THURS...AND RESULTING IN BRIEF PERIOD OF DRY WX. THE REGION REMAINS POSITIONED AT THE BASE OF A BROAD UPPER LVL CLOSED LOW...WHICH WILL SEND THROUGH THE NEXT COLD FRONT MIDWEEK...BRINGING THE NEXT CHC FOR PCPN. NEAR NORMAL TEMPS EXPECTED THROUGH THE PERIOD ON WLY FLOW. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... VFR WITH DRY CONDITIONS EXPECTED AT THE TERMINALS THROUGH NOON. A SFC TROUGH ACROSS THE OHIO VALLEY WILL MOVE FROM WEST TO EAST ACROSS THE TERMINALS THIS AFTERNOON. SHOWERS WILL REDEVELOP. AN ISOLATED TS IS POSSIBLE MAINLY CHO-DCA. IN TERMS OF WINDS...SW FLOW IN THE MORNING WITH POTENTIAL FOR GUSTS TO AROUND 15 KT. GUSTS ARE EXPECTED TO DIMINISH BY EARLY AFTERNOON. WINDS WILL SHIFT TO THE W THIS AFTN AND EVENTUALLY TO THE NW BY LATE AFTERNOON. VFR CONDITIONS EXPECTED TONIGHT AND SATURDAY. VFR CONDITIONS SAT NIGHT-SUN. SUB-VFR CONDITIONS BCMG LIKELY BY SUN NIGHT WITH WIDESPREAD RAIN. PERIODS OF HEAVIER RAIN COULD DROP CONDITIONS TO SUB-IFR SUN NIGHT. LLWS CONCERNS PSBL MON MORNING WITH SE WINDS 40-50 KTS AT 2KFT...SHIFTING TO THE SOUTH DURING THE MORNING. SUB-VFR CONDITIONS REMAIN PSBL DURING THE DAY MON AS A COLD FRONT BRINGS ANOTHER ROUND OF PCPN. SLIGHT CHC OF THUNDER CURRENTLY FOR THE TAF SITES...MAINLY MON AFTN/EVENING. WIND SHIFT EXPECTED MON EVENING WITH FRONTAL PASSAGE. VFR CONDITIONS MON NIGHT AS THE PCPN TAPERS OFF...LASTING THRU WED. && .MARINE... SCA HAS BEEN CANCELLED...AS WINDS HAVE DIMINISHED TO AROUND 10KT OVER MOST OF THE WATERS. A SFC TROUGH WILL CROSS THE WATERS THIS AFTERNOON. SHOWERS ARE EXPECTED AND AN ISOLATED THUNDERSTORM IS POSSIBLE MAINLY ACROSS THE SOUTHERN WATERS. S WINDS BECOME W-NW THIS EVENING. HIGH PRESSURE BUILDS IN TONIGHT AND SATURDAY. GENERALLY SUB-SCA CONDITIONS SAT NIGHT-SUN. SCA CONDITIONS PSBL BY SUN NIGHT WITH INCRSG ELY FLOW. SCA CONDITIONS LAST DURING THE DAY MON AHEAD OF THE COLD FRONT...BCMG SUB-SCA MON EVENING. GUSTS TO 20 KTS PSBL AGAIN TUES AFTN IN THE WAKE OF THE FRONT. && .EQUIPMENT... AUDIO DEGRADATION AT THE NOAA WEATHER RADIO CHARLOTTESVILLE TRANSMITTER IS EXPECTED TO CONTINUE THROUGH THIS WEEKEND. TECHNICIANS ARE SCHEDULED TO PERFORM MAINTENANCE AT THE TRANSMITTER SITE MONDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...SEARS/KCS NEAR TERM...HAS/KCS SHORT TERM...HAS LONG TERM...SEARS AVIATION...SEARS/HAS/KCS MARINE...SEARS/HAS/KCS EQUIPMENT...KCS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
751 AM EDT FRI APR 17 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE COAST THIS MORNING. A SURFACE TROUGH WILL PASS THROUGH THE REGION TODAY AND HIGH PRESSURE WILL RETURN FOR SATURDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY AND A WARM FRONT WILL MOVE INTO THE AREA SUNDAY NIGHT INTO MONDAY. A COLD FRONT WILL PASS THROUGH LATE MONDAY INTO MONDAY NIGHT BEFORE HIGH PRESSURE RETURNS FOR THE MIDDLE PORTION OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... HIGH PRESSURE WILL PERSIST OFF THE EAST COAST THIS MORNING. AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE MID-ATLANTIC THIS MORNING...FOLLOWED BY A SURFACE TROUGH LATER TODAY. EARLIER SHOWER ACTIVITY HAS MOVED INTO THE DELMARVA REGION. SOME SCATTERED AREAS OF LIGHT RAIN ASSOCIATED WITH THE UPPER TROUGH TO OUR WEST ARE APPROACHING THE HIGHLANDS. FURTHER EAST... A PERIOD OF DRY CONDITIONS IS EXPECTED THIS MORNING BETWEEN THE EXITING UPPER LEVEL DISTURBANCE AND INCOMING SFC TROUGH. TEMPS SHOULD RISE INTO THE L-M 70S BY AFTERNOON. NW FLOW WILL DRAW IN COLD DRY AIR ALOFT TODAY. THIS WILL CAUSE LAPSE RATES TO INCREASE AND SHOWERS ARE EXPECTED TO FORM ALONG THE SFC TROUGH BY EARLY AFTERNOON. LATEST HRRR GUIDANCE SHOWS A BKN LINE OF CONVECTIVE SHOWERS TO MOVE E-SE THROUGH THE AFTERNOON. AS THE SHOWERS MOVE PAST I-66...WARMER SFC TEMPS AND DECENT BOUNDARY LAYER MIXING WILL ALLOW A FEW HUNDRED J/KG OF CAPE. A FEW THUNDERSTORMS ARE POSSIBLE SOUTH OF I-66/MD RT50 LATE THIS AFTERNOON AND EARLY EVENING. CLEARING IS EXPECTED BEHIND THE SFC TROUGH INTO THE EVENING. HIGH PRESSURE WILL MOVE INTO THE REGION TONIGHT AND PERSIST SATURDAY. FCST MIN TEMPS INT HE 50S EXPECTED TONIGHT. FULL SUNSHINE WILL ALLOW TEMPS TO RISE INTO THE UPPER 70S TO NEAR 80 IN THE METROS SATURDAY. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... REGION REMAINS ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE CENTERED JUST NORTH OF THE GREAT LAKES. RIDGING BUILDS IN ALOFT...WITH THE RIDGE AXIS SHIFTING ACROSS THE MID ATLANTIC BY SUN MORNING. OVERALL PATTERN WILL KEEP THE AREA DRY. CLOUDS WILL BEGIN TO INCREASE FROM THE SOUTHWEST AHEAD OF THE NEXT FRONTAL SYSTEM. WINDS WILL LIGHTEN AND BECOME NE OVERNIGHT AS THE HIGH BUILDS SOUTH. && .LONG TERM /MONDAY THROUGH THURSDAY/... 00Z MODEL SUITE CONTINUING WITH A SLOWER PROGRESSION OF THE NEXT FRONTAL SYSTEM...AND THE ARRIVAL TIMING OF THE PCPN. RIDGE AXIS SHIFTS EAST DURING THE DAY SUNDAY AS A DEEPENING CLOSED LOW OVER THE NORTHERN PLAINS BUILDS EAST. BROAD LOW PRESSURE AT THE SFC OVER THE CENTRAL PLAINS BECOMES ORGANIZED DURING HE DAY AS WELL AS IT MOVES INTO THE WESTERN GREAT LAKES...GRADUALLY LIFTING THE ASSOCIATED WARM FRONT TO THE NORTH AND INTO THE MID ATLANTIC. GENERAL CONSENSUS AMONGST THE MODELS KEEPS THE WARM FRONT AT OR JUST SOUTH OF THE VA/NC BORDER THRU SUN NIGHT...WITH PCPN OCCURRING SUN-SUN NIGHT AS A RESULT OF DYNAMIC FORCING ALOFT WITH MULTIPLE MID LVL SHORTWAVES AND STRENGTHENING LLJ AND 250MB JET. PWATS INCRSG TO BETWEEN 1.2-1.4 IN...WHICH COULD RESULT IN PERIODS OF MODERATE TO HEAVY RAIN. SOME UNCERTAINTY STILL EXISTS WITH PCPN TIMING AND TSTM DEVELOPMENT ON MONDAY. WARM FRONT LOOKS TO BE NEAR THE VA/NC BORDER EARLY MONDAY...THEN GRADUALLY LIFTING NORTH DURING THE DAY. HOW QUICKLY IT CAN CLEAR THE CWA AND WARM SECTOR THE AREA WILL AFFECT THE EXTENT OF TSTM DEVELOPMENT...AND AS SUCH WILL CONTINUE TO MENTION SLIGHT CHC T FOR MOST OF THE AREA NOW...AND CHC OVER CENTRAL VA WHERE THE BEST DAYTIME HEATING SHOULD OCCUR. KEPT NORTHEASTERN MD OUT OF THE THUNDER MENTION FOR NOW WITH COOLER TEMPS EXPECTED. IN ADDITION...THINKING THERE SHOULD BE TWO ROUNDS OF PCPN...THE INITIAL SUN NIGHT...WITH A BREAK AT SOME POINT MONDAY WITH THE NEXT ROUND MOVING IN AHEAD OF THE APPROACHING COLD FRONT. THE COLD FRONT PUSHES THROUGH MONDAY NIGHT...WITH PCPN CLEARING TO THE EAST BY EARLY TUES MORNING. SFC HIGH PRESSURE BUILDS IN FROM THE SOUTH IN THE WAKE OF THE FRONT THRU WED...QUICKLY PROGRESSING OFFSHORE BY THURS...AND RESULTING IN BRIEF PERIOD OF DRY WX. THE REGION REMAINS POSITIONED AT THE BASE OF A BROAD UPPER LVL CLOSED LOW...WHICH WILL SEND THROUGH THE NEXT COLD FRONT MIDWEEK...BRINGING THE NEXT CHC FOR PCPN. NEAR NORMAL TEMPS EXPECTED THROUGH THE PERIOD ON WLY FLOW. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... ANY LEFTOVER MVFR CIGS WILL IMPROVE TO VFR OVER THE NEXT HOUR OR SO. THEN VFR WITH DRY CONDITIONS EXPECTED THROUGH NOON. A SFC TROUGH ACROSS THE OHIO VALLEY WILL MOVE FROM WEST TO EAST ACROSS THE TERMINALS THIS AFTERNOON. SHOWERS WILL REDEVELOP. AN ISOLATED TS IS POSSIBLE MAINLY CHO-DCA. IN TERMS OF WINDS...SW FLOW IN THE MORNING WITH POTENTIAL FOR GUSTS TO AROUND 15 KT. GUSTS ARE EXPECTED TO DIMINISH BY EARLY AFTERNOON. WINDS WILL SHIFT TO THE W THIS AFTN AND EVENTUALLY TO THE NW BY LATE AFTERNOON. VFR CONDITIONS EXPECTED TONIGHT AND SATURDAY. VFR CONDITIONS SAT NIGHT-SUN. SUB-VFR CONDITIONS BCMG LIKELY BY SUN NIGHT WITH WIDESPREAD RAIN. PERIODS OF HEAVIER RAIN COULD DROP CONDITIONS TO SUB-IFR SUN NIGHT. LLWS CONCERNS PSBL MON MORNING WITH SE WINDS 40-50 KTS AT 2KFT...SHIFTING TO THE SOUTH DURING THE MORNING. SUB-VFR CONDITIONS REMAIN PSBL DURING THE DAY MON AS A COLD FRONT BRINGS ANOTHER ROUND OF PCPN. SLIGHT CHC OF THUNDER CURRENTLY FOR THE TAF SITES...MAINLY MON AFTN/EVENING. WIND SHIFT EXPECTED MON EVENING WITH FRONTAL PASSAGE. VFR CONDITIONS MON NIGHT AS THE PCPN TAPERS OFF...LASTING THRU WED. && .MARINE... SHOWERS HAVE MOVED EAST OF THE WATERS. SOUTHERLY CHANNELING IS EXPECTED THIS MORNING AS A PRESSURE GRADIENT TIGHTENS ACROSS THE WATERS. A SCA IS IN EFFECT FOR THE LOWER TIDAL POTOMAC AND MD CHESAPEAKE BAY FOR GUSTS 18-20KTS. A SFC TROUGH WILL CROSS THE WATERS THIS AFTERNOON. SHOWERS ARE EXPECTED AND AN ISOLATED THUNDERSTORM IS POSSIBLE MAINLY ACROSS THE SOUTHERN WATERS. S WINDS BECOME W-NW THIS EVENING. HIGH PRESSURE BUILDS IN TONIGHT AND SATURDAY. GENERALLY SUB-SCA CONDITIONS SAT NIGHT-SUN. SCA CONDITIONS PSBL BY SUN NIGHT WITH INCRSG ELY FLOW. SCA CONDITIONS LAST DURING THE DAY MON AHEAD OF THE COLD FRONT...BCMG SUB-SCA MON EVENING. GUSTS TO 20 KTS PSBL AGAIN TUES AFTN IN THE WAKE OF THE FRONT. && .EQUIPMENT... AUDIO DEGRADATION AT THE NOAA WEATHER RADIO CHARLOTTESVILLE TRANSMITTER IS EXPECTED TO CONTINUE THROUGH THIS WEEKEND. TECHNICIANS ARE SCHEDULED TO PERFORM MAINTENANCE AT THE TRANSMITTER SITE MONDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>534- 537>543. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>534- 537>543. && $$ SYNOPSIS...SEARS NEAR TERM...HAS/KCS SHORT TERM...HAS LONG TERM...SEARS AVIATION...SEARS/HAS/KCS MARINE...SEARS/HAS/KCS EQUIPMENT...KCS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
359 AM EDT FRI APR 17 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE COAST THIS MORNING. A SURFACE TROUGH WILL PASS THROUGH THE REGION TODAY AND HIGH PRESSURE WILL RETURN FOR SATURDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY AND A WARM FRONT WILL MOVE INTO THE AREA SUNDAY NIGHT INTO MONDAY. A COLD FRONT WILL PASS THROUGH LATE MONDAY INTO MONDAY NIGHT BEFORE HIGH PRESSURE RETURNS FOR THE MIDDLE PORTION OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE EAST COAST THIS MORNING. AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE MID- ATLANTIC THIS MORNING. WARM AIR ADVECTION COUPLED WITH AN UPPER LEVEL DISTURBANCE HAS ALLOWED SHOWERS TO MOVE ACROSS THE I-95 CORRIDOR THIS MORNING. LESS THAN A QUARTER INCH HAS BEEN REPORTED OVERNIGHT. AN UPPER LEVEL TROUGH WILL SWING THROUGH THE MID- ATLANTIC THIS MORNING AND MOISTURE AND LIFT WILL PUSH OFF THE EAST COAST GIVING WAY TO DRIER CONDITIONS. SHOWERS WILL DIMINISH BY MID- MORNING BUT A SFC TROUGH CURRENTLY ACROSS THE OHIO VALLEY WILL MOVE THROUGH THE REGION TODAY AND INCREASE POTENTIAL FOR MORE SHOWERS. A PERIOD OF DRY CONDITIONS ARE EXPECTED THIS MORNING BETWEEN THE EXITING UPPER LEVEL DISTURBANCE AND INCOMING SFC TROUGH. TEMPS SHOULD RISE INTO THE L-M 70S BY AFTERNOON. NW FLOW WILL DRAW IN COLD DRY AIR ALOFT TODAY. THIS WILL CAUSE LAPSE RATES TO INCREASE AND SHOWERS ARE EXPECTED TO FORM ALONG THE SFC TROUGH BY EARLY AFTERNOON. LATEST HRRR GUIDANCE SHOWS A BKN LINE OF CONVECTIVE SHOWERS TO MOVE E-SE THROUGH THE AFTERNOON. AS THE SHOWERS MOVE PAST I-66...WARMER SFC TEMPS AND DECENT BOUNDARY LAYER MIXING WILL ALLOW A FEW HUNDRED J/KG OF CAPE. A FEW THUNDERSTORMS ARE POSSIBLE SOUTH OF I-66/MD RT50 LATE THIS AFTERNOON AND EARLY EVENING. CLEARING IS EXPECTED BEHIND THE SFC TROUGH INTO THE EVENING. HIGH PRESSURE WILL MOVE INTO THE REGION TONIGHT AND PERSIST SATURDAY. FCST MIN TEMPS INT HE 50S EXPECTED TONIGHT. FULL SUNSHINE WILL ALLOW TEMPS TO RISE INTO THE UPPER 70S TO NEAR 80 IN THE METROS SATURDAY. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... REGION REMAINS ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE CENTERED JUST NORTH OF THE GREAT LAKES. RIDGING BUILDS IN ALOFT...WITH THE RIDGE AXIS SHIFTING ACROSS THE MID ATLANTIC BY SUN MORNING. OVERALL PATTERN WILL KEEP THE AREA DRY. CLOUDS WILL BEGIN TO INCREASE FROM THE SOUTHWEST AHEAD OF THE NEXT FRONTAL SYSTEM. WINDS WILL LIGHTEN AND BECOME NE OVERNIGHT AS THE HIGH BUILDS SOUTH. && .LONG TERM /MONDAY THROUGH THURSDAY/... 00Z MODEL SUITE CONTINUING WITH A SLOWER PROGRESSION OF THE NEXT FRONTAL SYSTEM...AND THE ARRIVAL TIMING OF THE PCPN. RIDGE AXIS SHIFTS EAST DURING THE DAY SUNDAY AS A DEEPENING CLOSED LOW OVER THE NORTHERN PLAINS BUILDS EAST. BROAD LOW PRESSURE AT THE SFC OVER THE CENTRAL PLAINS BECOMES ORGANIZED DURING HE DAY AS WELL AS IT MOVES INTO THE WESTERN GREAT LAKES...GRADUALLY LIFTING THE ASSOCIATED WARM FRONT TO THE NORTH AND INTO THE MID ATLANTIC. GENERAL CONSENSUS AMONGST THE MODELS KEEPS THE WARM FRONT AT OR JUST SOUTH OF THE VA/NC BORDER THRU SUN NIGHT...WITH PCPN OCCURRING SUN-SUN NIGHT AS A RESULT OF DYNAMIC FORCING ALOFT WITH MULTIPLE MID LVL SHORTWAVES AND STRENGTHENING LLJ AND 250MB JET. PWATS INCRSG TO BETWEEN 1.2-1.4 IN...WHICH COULD RESULT IN PERIODS OF MODERATE TO HEAVY RAIN. SOME UNCERTAINTY STILL EXISTS WITH PCPN TIMING AND TSTM DEVELOPMENT ON MONDAY. WARM FRONT LOOKS TO BE NEAR THE VA/NC BORDER EARLY MONDAY...THEN GRADUALLY LIFTING NORTH DURING THE DAY. HOW QUICKLY IT CAN CLEAR THE CWA AND WARM SECTOR THE AREA WILL AFFECT THE EXTENT OF TSTM DEVELOPMENT...AND AS SUCH WILL CONTINUE TO MENTION SLIGHT CHC T FOR MOST OF THE AREA NOW...AND CHC OVER CENTRAL VA WHERE THE BEST DAYTIME HEATING SHOULD OCCUR. KEPT NORTHEASTERN MD OUT OF THE THUNDER MENTION FOR NOW WITH COOLER TEMPS EXPECTED. IN ADDITION...THINKING THERE SHOULD BE TWO ROUNDS OF PCPN...THE INITIAL SUN NIGHT...WITH A BREAK AT SOME POINT MONDAY WITH THE NEXT ROUND MOVING IN AHEAD OF THE APPROACHING COLD FRONT. THE COLD FRONT PUSHES THROUGH MONDAY NIGHT...WITH PCPN CLEARING TO THE EAST BY EARLY TUES MORNING. SFC HIGH PRESSURE BUILDS IN FROM THE SOUTH IN THE WAKE OF THE FRONT THRU WED...QUICKLY PROGRESSING OFFSHORE BY THURS...AND RESULTING IN BRIEF PERIOD OF DRY WX. THE REGION REMAINS POSITIONED AT THE BASE OF A BROAD UPPER LVL CLOSED LOW...WHICH WILL SEND THROUGH THE NEXT COLD FRONT MIDWEEK...BRINGING THE NEXT CHC FOR PCPN. NEAR NORMAL TEMPS EXPECTED THROUGH THE PERIOD ON WLY FLOW. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... MVFR CONDITIONS POSSIBLE THIS MORNING AS CIGS LOWER BEHIND EXITING SHOWERS. CIGS SHOULD BECOME VFR SHORTLY AFTER SUNRISE AND A PERIOD OF DRY CONDTIONS EXPECTED THROUGH NOON. A SFC TROUGH ACROSS THE OHIO VALLEY WILL MOVE FROM WEST TO EAST ACROSS THE TERMINALS THIS AFTERNOON. SHOWERS WILL REDEVELOP. AN ISOLATED TS IS POSSIBLE MAINLY CHO-DCA. A WIND SHIFT FROM S-SW TO W-NW EXPECTED TODAY. VFR CONDITIONS EXPECTED TONIGHT AND SATURDAY. VFR CONDITIONS SAT NIGHT-SUN. SUB-VFR CONDITIONS BCMG LIKELY BY SUN NIGHT WITH WIDESPREAD RAIN. PERIODS OF HEAVIER RAIN COULD DROP CONDITIONS TO SUB-IFR SUN NIGHT. LLWS CONCERNS PSBL MON MORNING WITH SE WINDS 40-50 KTS AT 2KFT...SHIFTING TO THE SOUTH DURING THE MORNING. SUB-VFR CONDITIONS REMAIN PSBL DURING THE DAY MON AS A COLD FRONT BRINGS ANOTHER ROUND OF PCPN. SLIGHT CHC OF THUNDER CURRENTLY FOR THE TAF SITES...MAINLY MON AFTN/EVENING. WIND SHIFT EXPECTED MON EVENING WITH FRONTAL PASSAGE. VFR CONDITIONS MON NIGHT AS THE PCPN TAPERS OFF...LASTING THRU WED. && .MARINE... SHOWERS WILL MOVE EAST OF THE WATERS BY MID-MORNING. SOUTHERLY CHANNELING IS EXPECTED THIS MORNING AS A PRESSURE GRADIENT TIGHTENS ACROSS THE WATERS. A SCA IS IN EFFECT FOR THE LOWER TIDAL POTOMAC AND MD CHESAPEAKE BAY FOR GUSTS 18-20KTS. A SFC TROUGH WILL CROSS THE WATERS THIS AFTERNOON. SHOWERS ARE EXPECTED AND AN ISOLATED THUNDERSTORM IS POSSIBLE MAINLY ACROSS THE SOUTHERN WATERS. S WINDS BECOME W-NW THIS EVENING. HIGH PRESSURE BUILDS IN TONIGHT AND SATURDAY. GENERALLY SUB-SCA CONDITIONS SAT NIGHT-SUN. SCA CONDITIONS PSBL BY SUN NIGHT WITH INCRSG ELY FLOW. SCA CONDITIONS LAST DURING THE DAY MON AHEAD OF THE COLD FRONT...BCMG SUB-SCA MON EVENING. GUSTS TO 20 KTS PSBL AGAIN TUES AFTN IN THE WAKE OF THE FRONT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>534- 537>543. && $$ SYNOPSIS...SEARS/HAS NEAR TERM...HAS SHORT TERM...HAS LONG TERM...SEARS AVIATION...SEARS/HAS MARINE...SEARS/HAS
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
703 PM CDT Sat Apr 18 2015 ...Update to Aviation Section... .UPDATE... Issued at 703 PM CDT SAT APR 18 2015 Forecast will be updated shortly to account for short term trends from satellite/radar as well as to account for expected convective trends heading into the overnight hours. Over the past few hours, we have seen clearing across western portions of the area. This clearing will likely be short lived as mid/high level clouds increase from the west from convective exhaust. That said, this area did see a soaking rain this morning and dewpoints remain relatively high compared to expected lows. As a result, will include a mention of patchy fog and keep an eye on localized dense fog potential in places where skies can remain clear for a longer period of time. In addition, PoPs have been updated for the next 12 or so hours. The western half of the area will likely see little in the way of rain chances this evening. Chances over the eastern half look to remain in the solid chance range giving on again/off again showers and isolated thunder. HRRR and other short range models continue to indicate rain chances increasing across south central Missouri and the eastern Ozarks from late this evening into the overnight hours. In addition, remnant convection from KS/OK complexes will enter from the west, with rain chances steadily increasing across extreme southeastern Kansas and western Missouri. Interestingly, the Highway 65 corridor will likely be between these two areas of activity and PoPs are lowest in this area for tonight. Taking a peak at tomorrow`s severe weather potential. There remains some question as to just how much instability we will be able to generate as decaying convection continues to spread in from the west during the morning hours. The main upper trough will not arrive until later in the day, bringing and increase in deep layer shear. However, models struggle to bring much more that 500-1000 J/kg of most unstable CAPE into the southern half of the area. By far the better chances for severe convection will be to our south and southeast. Obviously this is close enough to keep a close eye on trends and we will see what the 00z suite of models have in store for the area. && .SHORT TERM...(This Evening through Sunday Night) Issued at 315 PM CDT SAT APR 18 2015 The coverage of showers and thunderstorms continued to decrease into the afternoon. However a band of scattered showers and storms persisted along a 925-850 MB convergence axis that stretched north to south east of the Highway 65 corridor and in advance of a mid level vorticity lobe lifting northeast across the area. Expect convection through early evening to be focused along and ahead of these features across south central Missouri. This 925-850 MB convergence axis may become the focus for additional development later tonight across the eastern Ozarks as another vorticity lobe lifts northeast toward southeastern Missouri. Coverage of precipitation will remain more isolated elsewhere much of tonight. However there may be increase in convection from the west into southeastern Kansas into far southwest late tonight as convection across the Plains shifts eastward. The closed upper level low now over eastern Colorado will open up and track eastward toward Missouri on Sunday. Expect the coverage of convection to increase Sunday as synoptic scale lift increases with the aide of an increasingly diffluent upper flow and the approach of vorticity maxima. Deep layer shear will increase Sunday as the mid level flow strengthens and lapse rates steepen as temperatures aloft cool in response to the approaching upper level trough. The question is the extent of instability that will develop. The potential for ongoing convection and cloud cover may limit surface heating and resulting instability. However if sufficient instability can be realized then ingredients would be in place for at least a few severe storms. At this time the greatest potential for strong to severe storms will be across far southern Missouri or generally along and south of Interstate 44. The risk for severe weather could decrease or increase depending on the amount of destabilization. The primary risks with any severe storms that can develop would damaging winds and large hail. With some areas already receiving moderate to heavy rainfall the past couple of days...the risk for localized flooding will have to be monitored particularly across far southwestern Missouri. Showers and some thunder will linger into Sunday night as the upper level trough and associated cold front track across the area. .LONG TERM...(Monday through Saturday) Issued at 315 PM CDT SAT APR 18 2015 Much cooler weather will prevail heading into early next week as an upper level trough digs into the Great Lakes and maintains a northwesterly flow aloft across the region. This cooler weather will persist most of next week. Weather conditions could also be rather unsettled as disturbances slide southeastward around the periphery of the upper trough. This will bring intervals clouds and the possibility of showers and thunderstorms at times mid through late week. However this activity is expected to be spotty in nature. Temperatures could fall into the upper 30s Monday night. Frost is not expected at this time but this potential should be monitored. && .AVIATION...(For the 00Z TAFS through 00Z Sunday Evening) Issued at 703 PM CDT SAT APR 18 2015 Partial clearing, light winds and most grounds from earlier today will bring a risk of fog to the area late this evening into the overnight hours. At this time, have inserted MVFR fog at all sites, however there is a chance for IFR (possibly lower) conditions at BBG and SGF if skies can remain clear long enough into the overnight hours. Better rain chances this evening will be well to the west and just to the east of the aerodromes. Rain chances will increase overnight at JLN as a decaying complex of showers/storms approaches from KS/OK. This activity will spread eastward into the SGF/BBG aerodromes during the daylight hours of Sunday morning, with redevelopment of showers/storms possible at all sites Sunday afternoon before exiting Sunday evening. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ UPDATE...Gagan SHORT TERM...Foster LONG TERM...Foster AVIATION...Gagan
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1222 PM CDT Fri Apr 17 2015 .DISCUSSION... Issued at 435 AM CDT FRI APR 17 2015 Today - Tonight: Today will be a transition day. An upper ridge, now overhead, has kept the KS/OK/TX Panhandle convection at bay since yesterday. However, as the upper ridge nudges east this convection will be able to edge closer and closer. This activity has been generated by weak impulses ejecting from a cut-off upper low near the 4-corners area and mid-level frontogenesis. This upper low has moved little over the past 24 hours as it awaits its kicker which is just now crossing into British Columbia. This latter feature is expected to strengthen later today as upstream ridging sharpens and forces this shortwave trough to dig southeast into the Northern Rockies...but not until tomorrow. What this means is any convection reaching the CWA today will weaken/fall apart as it moves away from the better upper support. Having said that there are some signals from the last couple runs of the HRRR and to a lesser extent the 00z NAM that convection now moving east through northern OK/south central KS could reach the far western counties by around the noon hour. Regional radars show an outflow boundary now expanding east from the KS convection with new activity sprouting over north central OK. This activity is what the HRRR picks up on and lifts northeast later this morning. So, will slowly shift chance PoPs across the far western CWA today while leaving the eastern half dry. Convective debris clouds will also thin as they spread east today providing a thin veil of high clouds. This shouldn`t hold back warming and expect temperatures to top out in the middle and upper 70s. The Southern Plateau closed low will gradually shift east tonight, allowing new convection to push further east and become more organized as it reaches the KS/MO state line towards sunrise. Will handle this with a steady and gradual increase in PoPs through the night. Saturday - Sunday: A very wet period with convection becoming numerous and likely coming in waves as cells track nne while shifting slowly east. Model precipitable water values 2 to 3 standard deviations are a cause for concern. Steering winds in the 20kt area plus this moisture heighten the threat of localized flooding. Have increased qpf and this may even be underdone as its certainly feasible that some areas could see up to 2 inches of rain through Saturday night. Extensive cloud cover and rain-cooled air forces me to lower highs on both days and won`t be surprised if they are lowered further in future forecasts. Modest MLCAPEs and 0-6km shear in the 20-30kt range are not likely to support any severe threat on Saturday. Sunday may be a slightly different story. By then the closed upper low will have opened up and accelerated eastward. There is a chance we could be rain free Sunday morning with some partial sunshine. Should this occur more robust afternoon convection could form within a marginally supportive airmass featuring MLCAPEs of 1200-1400 J/kg but only 25-30kt 0-6 km bulk shear. Monday - Friday: The shortwave trough which will act as the kicker to move the current closed upper low near the 4-corners will have formed into a well developed upper trough from the Upper MS Valley through the Mid MO Valley early in this period. As the upper trough axis passes through on Monday strong subsidence and cold air advection will provide ample sunshine but below average temperatures through Tuesday. By mid week, an upper ridge axis will build east into the Central Plains with warm air advection spreading east. The GFS is more aggressive and faster than the ECMWF in pushing weak mid level vorticity lobes through the ridge axis. These features will be ejected from a broad upper trough that will works into the desert southwest. Difficult to determine how soon any scattered convection could work its way back into the region. For now will introduce some low chance PoPs for late Wednesday into Thursday. The current closed upper low now over northern Mexico is expected to weaken as it lifts north-northeast through the Central Plains and CWA. While there should be decent moisture lifted northward with this feature minimal instability will limit amount of thunder. Given that the operational models have been generating a similar solution believe 30-40 PoPs are warranted for scattered convection. Thursday - Sunday: Roll of the dice as to how weather will evolve from Thursday through Sunday. Not especially fond of the blended model approach of carpet bombing chance PoPs in every period. The medium range models drop a deep upper trough into the Desert Southwest and then cut it off. Models typically are challenged significantly with these features initially. They tend to lift them out too soon and too far east. Will be interesting to see how this system is handled going forward. Difficult trying to time any weak impulse ejected from this system within the downstream southwesterly flow. For now will handle this with low chance PoPs with above average temperatures. && .AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon) Issued at 1217 PM CDT FRI APR 17 2015 Band of showers will continue moving northeast, gradually weakening while isolated convection will develop ahead of the activity. Lightning has been on the decrease as the band has weakened, and with the anticipated more scattered nature with time, expect VCSH instead of prevailing period of precipitation. Rain should clear terminal by mid-afternoon, with a lull in activity through midnight. Next round of showers and embedded thunderstorms expected overnight, with one or more rounds of convection through the end of the TAF period. Will likely see periods of reduced visibility with overnight activity, but prediction of specific reduction time is low and precludes mention at this time. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ DISCUSSION...MJ AVIATION...Blair
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
643 AM CDT Fri Apr 17 2015 .DISCUSSION... Issued at 435 AM CDT FRI APR 17 2015 Today - Tonight: Today will be a transition day. An upper ridge, now overhead, has kept the KS/OK/TX Panhandle convection at bay since yesterday. However, as the upper ridge nudges east this convection will be able to edge closer and closer. This activity has been generated by weak impulses ejecting from a cut-off upper low near the 4-corners area and mid-level frontogenesis. This upper low has moved little over the past 24 hours as it awaits its kicker which is just now crossing into British Columbia. This latter feature is expected to strengthen later today as upstream ridging sharpens and forces this shortwave trough to dig southeast into the Northern Rockies...but not until tomorrow. What this means is any convection reaching the CWA today will weaken/fall apart as it moves away from the better upper support. Having said that there are some signals from the last couple runs of the HRRR and to a lesser extent the 00z NAM that convection now moving east through northern OK/south central KS could reach the far western counties by around the noon hour. Regional radars show an outflow boundary now expanding east from the KS convection with new activity sprouting over north central OK. This activity is what the HRRR picks up on and lifts northeast later this morning. So, will slowly shift chance PoPs across the far western CWA today while leaving the eastern half dry. Convective debris clouds will also thin as they spread east today providing a thin veil of high clouds. This shouldn`t hold back warming and expect temperatures to top out in the middle and upper 70s. The Southern Plateau closed low will gradually shift east tonight, allowing new convection to push further east and become more organized as it reaches the KS/MO state line towards sunrise. Will handle this with a steady and gradual increase in PoPs through the night. Saturday - Sunday: A very wet period with convection becoming numerous and likely coming in waves as cells track nne while shifting slowly east. Model precipitable water values 2 to 3 standard deviations are a cause for concern. Steering winds in the 20kt area plus this moisture heighten the threat of localized flooding. Have increased qpf and this may even be underdone as its certainly feasible that some areas could see up to 2 inches of rain through Saturday night. Extensive cloud cover and rain-cooled air forces me to lower highs on both days and won`t be surprised if they are lowered further in future forecasts. Modest MLCAPEs and 0-6km shear in the 20-30kt range are not likely to support any severe threat on Saturday. Sunday may be a slightly different story. By then the closed upper low will have opened up and accelerated eastward. There is a chance we could be rain free Sunday morning with some partial sunshine. Should this occur more robust afternoon convection could form within a marginally supportive airmass featuring MLCAPEs of 1200-1400 J/kg but only 25-30kt 0-6 km bulk shear. Monday - Friday: The shortwave trough which will act as the kicker to move the current closed upper low near the 4-corners will have formed into a well developed upper trough from the Upper MS Valley through the Mid MO Valley early in this period. As the upper trough axis passes through on Monday strong subsidence and cold air advection will provide ample sunshine but below average temperatures through Tuesday. By mid week, an upper ridge axis will build east into the Central Plains with warm air advection spreading east. The GFS is more aggressive and faster than the ECMWF in pushing weak mid level vorticity lobes through the ridge axis. These features will be ejected from a broad upper trough that will works into the desert southwest. Difficult to determine how soon any scattered convection could work its way back into the region. For now will introduce some low chance PoPs for late Wednesday into Thursday. The current closed upper low now over northern Mexico is expected to weaken as it lifts north-northeast through the Central Plains and CWA. While there should be decent moisture lifted northward with this feature minimal instability will limit amount of thunder. Given that the operational models have been generating a similar solution believe 30-40 PoPs are warranted for scattered convection. Thursday - Sunday: Roll of the dice as to how weather will evolve from Thursday through Sunday. Not especially fond of the blended model approach of carpet bombing chance PoPs in every period. The medium range models drop a deep upper trough into the Desert Southwest and then cut it off. Models typically are challenged significantly with these features initially. They tend to lift them out too soon and too far east. Will be interesting to see how this system is handled going forward. Difficult trying to time any weak impulse ejected from this system within the downstream southwesterly flow. For now will handle this with low chance PoPs with above average temperatures. && .AVIATION...(For the 12Z TAFS through 12Z Saturday Morning) Issued at 639 AM CDT FRI APR 17 2015 Generally VFR conditions through this evening with a steady stream of higher based clouds. Watching a band of showers and storms over north central OK and south central KS that are starting to turn to the northeast. Seeing signs this activity could lift through far eastern KS and western MO but weaken during the afternoon hours. Rest of northern and central MO should stay dry through the afternoon hours. If current trends continue will likely need to amend forecast and increase chances for thunder. Should see a lull in activity this evening but another round of more robust convection should form over KS tonight and reach far eastern KS and western MO during the pre- dawn hours of Saturday morning. Should see MVFR visibilities with this batch of showers and storms. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ DISCUSSION...MJ AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
436 AM CDT Fri Apr 17 2015 .DISCUSSION... Issued at 435 AM CDT FRI APR 17 2015 Today - Tonight: Today will be a transition day. An upper ridge, now overhead, has kept the KS/OK/TX Panhandle convection at bay since yesterday. However, as the upper ridge nudges east this convection will be able to edge closer and closer. This activity has been generated by weak impulses ejecting from a cut-off upper low near the 4-corners area and mid-level frontogenesis. This upper low has moved little over the past 24 hours as it awaits its kicker which is just now crossing into British Columbia. This latter feature is expected to strengthen later today as upstream ridging sharpens and forces this shortwave trough to dig southeast into the Northern Rockies...but not until tomorrow. What this means is any convection reaching the CWA today will weaken/fall apart as it moves away from the better upper support. Having said that there are some signals from the last couple runs of the HRRR and to a lesser extent the 00z NAM that convection now moving east through northern OK/south central KS could reach the far western counties by around the noon hour. Regional radars show an outflow boundary now expanding east from the KS convection with new activity sprouting over north central OK. This activity is what the HRRR picks up on and lifts northeast later this morning. So, will slowly shift chance PoPs across the far western CWA today while leaving the eastern half dry. Convective debris clouds will also thin as they spread east today providing a thin veil of high clouds. This shouldn`t hold back warming and expect temperatures to top out in the middle and upper 70s. The Southern Plateau closed low will gradually shift east tonight, allowing new convection to push further east and become more organized as it reaches the KS/MO state line towards sunrise. Will handle this with a steady and gradual increase in PoPs through the night. Saturday - Sunday: A very wet period with convection becoming numerous and likely coming in waves as cells track nne while shifting slowly east. Model precipitable water values 2 to 3 standard deviations are a cause for concern. Steering winds in the 20kt area plus this moisture heighten the threat of localized flooding. Have increased qpf and this may even be underdone as its certainly feasible that some areas could see up to 2 inches of rain through Saturday night. Extensive cloud cover and rain-cooled air forces me to lower highs on both days and won`t be surprised if they are lowered further in future forecasts. Modest MLCAPEs and 0-6km shear in the 20-30kt range are not likely to support any severe threat on Saturday. Sunday may be a slightly different story. By then the closed upper low will have opened up and accelerated eastward. There is a chance we could be rain free Sunday morning with some partial sunshine. Should this occur more robust afternoon convection could form within a marginally supportive airmass featuring MLCAPEs of 1200-1400 J/kg but only 25-30kt 0-6 km bulk shear. Monday - Friday: The shortwave trough which will act as the kicker to move the current closed upper low near the 4-corners will have formed into a well developed upper trough from the Upper MS Valley through the Mid MO Valley early in this period. As the upper trough axis passes through on Monday strong subsidence and cold air advection will provide ample sunshine but below average temperatures through Tuesday. By mid week, an upper ridge axis will build east into the Central Plains with warm air advection spreading east. The GFS is more aggressive and faster than the ECMWF in pushing weak mid level vorticity lobes through the ridge axis. These features will be ejected from a broad upper trough that will works into the desert southwest. Difficult to determine how soon any scattered convection could work its way back into the region. For now will introduce some low chance PoPs for late Wednesday into Thursday. The current closed upper low now over northern Mexico is expected to weaken as it lifts north-northeast through the Central Plains and CWA. While there should be decent moisture lifted northward with this feature minimal instability will limit amount of thunder. Given that the operational models have been generating a similar solution believe 30-40 PoPs are warranted for scattered convection. Thursday - Sunday: Roll of the dice as to how weather will evolve from Thursday through Sunday. Not especially fond of the blended model approach of carpet bombing chance PoPs in every period. The medium range models drop a deep upper trough into the Desert Southwest and then cut it off. Models typically are challenged significantly with these features initially. They tend to lift them out too soon and too far east. Will be interesting to see how this system is handled going forward. Difficult trying to time any weak impulse ejected from this system within the downstream southwesterly flow. For now will handle this with low chance PoPs with above average temperatures. && .AVIATION...(For the 06Z TAFS through 06Z Friday Night) Issued at 1147 PM CDT THU APR 16 2015 VFR conditions to dominate through much of the fcst period...with winds remaining from the east and southeast between 5-10 kts. Clouds will be on the increase after 15z as long awaited storm system now across the Four Corners region slowly tracks east. Cannot rule out some isolated thunderstorms during the late afternoon...however more concentrated activity will likely hold off until after 00z. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ DISCUSSION...MJ AVIATION...32
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
613 PM CDT SAT APR 18 2015 .SYNOPSIS... ISSUED AT 255 PM CDT SAT APR 18 2015 ANALYSIS OF THE 19Z MSL DATA SHOWED LOW PRESSURE CENTERED IN WESTERN KANSAS WITH A WARM FRONT ACROSS NORTHERN KANSAS...A COLD FRONT INTO THE OKLAHOMA/TEXAS PANHANDLE AND AN INVERTED TROUGH FROM SOUTHWEST TO NORTH CENTRAL NEBRASKA. IN THE UPPER LEVELS...THE WATER VAPOR IMAGERY SHOWED A CLOSED CYCLONIC CIRCULATION LOCATED IN EASTERN COLORADO. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 255 PM CDT SAT APR 18 2015 THE CENTER OF STRONG CUT OFF LOW /H500 MB TEMP -25C/ IS NEAR AKRON COLORADO THIS AFTERNOON. HIGH RES MODELS INSIST THAT CONVECTION...AIDED BY A SIGNIFICANT PV ANOMALY ROTATING NORTHEAST INTO WESTERN KANSAS AROUND THE LOW CENTER...WILL DEVELOP ONCE AGAIN ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA LATE THIS AFTERNOON AND THIS EVENING. THE ACTIVITY WILL GROW UPSCALE MUCH LIKE LAST NIGHT AS IT MOVES NORTH/NORTHEAST INTO THE REST OF WESTERN...CENTRAL AND NORTH CENTRAL NEBRASKA TONIGHT. AS FAR AS SEVERE POTENTIAL...GOOD SURFACE HEATING UNDERWAY ATTM ACROSS SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. EXPECTING MUCAPE ON THE ORDER OF 1500 J/KG BY LATE AFTERNOON INTO THE EVENING HOURS. ONE WEAKNESS ARE THE WIND FIELDS ARE FAIRLY LIGHT...AND NOT A A LOT OF VEERING WITH HEIGHT. NEVERTHELESS WITH THE STEEP LOW AND MID LEVEL LAPSE RATES...WILL SEE SOME VIGOROUS UPDRAFTS...AND SOME HAIL LIKELY WITH THOSE STRONGER UPDRAFTS. TORNADO POTENTIAL IS NOT ZERO...BUT AGAIN WITH THE WEAK WIND FIELDS AND LIMITED VEERING...NOT EXPECTING THAT TO BE THE PRIMARY RISK. IF A TORNADO OCCURS IT WOULD MORE THAN LIKELY BE WEAK. K INDICES ARE HIGH...AND LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. THE CLOSED H500 MB CIRCULATION IS FORECASTED TO MIGRATE INTO NORTHWEST KANSAS BY SUNDAY MORNING...AND CONTINUE EAST ACROSS KANSAS DURING THE DAY. A SMALL DEFORMATION BAND OF PRECIPITATION IS LIKELY ON THE NORTH AND WEST SIDE OF THE TRACK. THE EXACT TRACK OF THE LOW CENTER IS UNCERTAIN...AS CONVECTION LIKELY TO INFLUENCE THE MASS FIELD AND EXPECT THE FINAL TRACK COULD END UP A LITTLE FARTHER NORTH. THIS IS HINTED IN THE LATEST RUN OF THE RAP MODEL. OTHERWISE A COLD FRONT ASSOCIATED WITH A SEPARATE NORTHERN STREAM SYSTEM WILL CRASH THROUGH THE AREA...BRINGING GUSTY NORTHWEST WINDS TO THE REGION. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 255 PM CDT SAT APR 18 2015 MEDIUM RANGE...(SUNDAY NIGHT THROUGH TUESDAY) THE UPPER LEVEL LOW ACROSS COLORADO WILL LIFT OUT AND COLLIDE WITH AN UPPER LEVEL SHORT WAVE ACROSS ACROSS THE NORTHERN GREAT LAKES FORMING A VERY LARGE CLOSED UPPER LOW. UPSTREAM HEIGHTS RISE SHARPLY ACROSS NRN CANADA SUPPORTING A BROAD AREA OF HIGH PRESSURE WHICH CIRCULATE COOL AIR SOUTH THROUGH THE PLAINS AND MIDWEST. THIS KEEPS THE FORECAST AREA IN COOL NORTHWEST FLOW. DAYTIME MIXING PRODUCES PARTLY CLOUDY SKIES MONDAY AND TUESDAY PLACING A LIMIT ON HEATING. MONDAY WOULD BE A WINDY DAY WITH NORTHWEST WINDS INCREASING TO 20 TO 30 MPH IN THE AFTN WHICH WEAKEN AT SUNSET. WINDS STAY REASONABLY STRONG SUNDAY NIGHT ALSO. THE EFFECT ON TEMPERATURES WOULD BE FOR LOWS MONDAY MORNING FALLING INTO THE UPPER 20S ACROSS WESTERN NEBRASKA BUT ABOVE FREEZING EAST OF HIGHWAY 83. LOWS FALL BELOW FREEZING EVERYWHERE MONDAY NIGHT EXCEPT ALONG HIGHWAY 281. HIGHS RISE INTO THE 50S MONDAY AND LOWER 60S TUESDAY. THE FORECAST IS DRY AND THE MODELS INDICATE DEW POINTS FALL INTO TEENS AND 20S SUNDAY NIGHT THROUGH TUESDAY. THE RISK TO THE FORECAST IS THAT THE VERY DRY AIR COULD SUPPORT COLDER LOWS THAN FORECAST BUT THAT WOULD COMPETE DIRECTLY WITH THE WARM WET GROUND FROM THE HEAVY RAINFALL. EXTENDED RANGE...(TUESDAY NIGHT THROUGH SATURDAY) A RIDGE IN WESTERN NORTH AMERICA CONTINUES TO BUILD INTO THE NORTHWEST TERRITORIES AND NORTHERN ALBERTA OPENING UP A PATH FROM NUNAVUT IN EXTREME NORTHERN CANADA TO NORTH CENTRAL AND NORTHEAST NEBRASKA. AS A RESULT...TEMPERATURES ARE EXPECTED TO BE A LITTLE BELOW THE SEASONAL AVERAGES IN THE NORTHEAST NEBRASKA SANDHILLS AND THE NIOBRARA VALLEY WITH NIGHTTIME TEMPERATURES AT OR BELOW FREEZING INTO FRIDAY MORNING. EVEN IN THE WESTERN SANDHILLS...THE EASTERN PANHANDLE AND SOUTHWEST NEBRASKA WILL BE SLIGHTLY BELOW AVERAGE WITH LOWS IN THE LOW TO MID 30S. IN THE SOUTHWEST STATES...A TROUGH DIGS INTO SOUTHERN CALIFORNIA RESULTING IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS. A WEAK INVERTED TROUGH MOVING ACROSS THE PLAINS COULD BRING THE POSSIBILITY OF SHOWERS TO CENTRAL AND WESTERN NEBRASKA THURSDAY THROUGH SATURDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 612 PM CDT SAT APR 18 2015 SCATTERED THUNDERSTORMS IN CENTRAL AND SOUTHWEST NEBRASKA ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY THIS EVENING UNTIL 02Z. DURING THAT TIME...HAIL AND VERY HEAVY RAIN CAN BE EXPECTED WITH LARGE HAIL POSSIBLE. AFTER 02Z...THE PROBABILITY OF THUNDERSTORMS WILL DECREASE. THEN...CEILING AND VISIBILITY WILL BE ABOVE THE INSTRUMENT THRESHOLD THOUGH MARGINAL CONDITIONS ARE POSSIBLE. AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN INCREASE TO 14-18G24-30KT BY 14Z. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SPRINGER SHORT TERM...TAYLOR LONG TERM...CDC/SPRINGER AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1203 PM CDT FRI APR 17 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 318 AM CDT FRI APR 17 2015 PCPN CHANCES AND TEMPERATURES ARE THE PRIMARY FORECAST CONCERNS IN THE TODAY PERIOD...THEN CONTINUED SHOWER/THUNDERSTORM CHANCES ESPECIALLY FRIDAY NIGHT THROUGH SATURDAY NIGHT...THEN THE COLD FRONTAL PASSAGE AND PRECIPITATION ENDING SUNDAY. REGIONAL RADAR EARLY THIS MORNING SHOWS AREA OF SHOWERS AND ISOLATED THUNDERSTORMS PIVOTING NORTH TO NORTHWEST FROM KANSAS INTO NEBRASKA AROUND CLOSED UPPER LOW OVER SOUTH CENTRAL COLORADO. WESTERN PORTIONS OF THE FORECAST AREA WILL BE MOST LIKELY TO SEE PRECIP TODAY WITH EASTERN AREAS HAVING TO WAIT UNTIL THE AFTERNOON FOR BETTER POPS AS THE UPPER LOW TRACKS SLOWLY EAST. RAP FORECAST SOUNDINGS SHOW LIMITED INSTABILITY THROUGH MOST OF THE DAY ESPECIALLY IN THE EAST AND NORTH WITH INCREASING INSTABILITY IN WESTERN PARTS OF THE AREA ALONG AND WEST OF A BEATRICE-LINCOLN- COLUMBUS ARC BY LATE AFTERNOON. CLOUD COVER IS EXPECTED TO REMAIN IN PLACE MUCH OF THE DAY FOR THE WEST HALF OF THE AREA WITH VARIABLE SKY COVER IN THE EAST HALF. THIS SPLIT SHOULD SEE LOWER TEMPS AROUND 70 CONFINED TO THE WEST WITH MID 70S IN THE EAST WHERE SOME PERIODS OF SUN ARE POSSIBLE. TONIGHT...THE OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT THE CLOSED H5 LOW OVER THE FOUR-CORNERS REGION WILL LIFT NORTHEAST TO COLORADO BY 00Z TONIGHT. THE H5 LOW MEANDERS OVER COLORADO THROUGH SATURDAY...THEN DRIFTS INTO WESTERN KANSAS BY 06Z. THE NAM IS SLIGHTLY DIFFERENT IN SPLITTING SOME OF THE H5 ENERGY TO THE NORTH IN SOUTH DAKOTA AND THE CLOSED LOW A LITTLE FARTHER SOUTH TOWARD OKLAHOMA. SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING OVER PARTS OF THE CWA AND WILL CONTINUE TO SPREAD NORTH AND EAST FRIDAY NIGHT AND SATURDAY. THESE PERIODS WILL HAVE THE HIGHEST POPS THIS WEEKEND. THE INSTABILITY AXIS DOES LIFT NORTHWARD FRIDAY NIGHT AND CONTINUES OVER THE AREA SATURDAY. THERE IS ALSO AN H85 BOUNDARY IN THIS REGION THAT LIFTS NORTH AND MAY PROVIDE A FOCUS FOR ENHANCED CONVECTIVE ACTIVITY. SOME .25-.5 INCH RAINS FELL ALONG WITH PEA TO DIME- SIZED HAIL WAS REPORTED WITH SOME OF THE STORMS IN SOUTHERN NEBRASKA THURSDAY NIGHT. FORECAST SOUNDINGS SHOW WEAK INSTABILITY WITH MLCAPE OF 200J/KG FRIDAY NIGHT...AND A LITTLE BETTER INSTABILITY WITH MLCAPE OF 500J/KG SATURDAY. SOME OF THE STRONGER STORMS MAY PRODUCE SOME HAIL. RAINFALL AMOUNTS THROUGH SATURDAY COULD RANGE FROM .5 TO 1 INCH. SATURDAY NIGHT...THE MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED TO SHIFT FARTHER EAST INTO IOWA AND EXTEND IN A LARGE AREA FROM THE GULF STATES THROUGH THE MISSISSIPPI VALLEY INTO MINNESOTA AND THE DAKOTA. THE LOW LEVEL JET OF 40-50KTS DEVELOPS OVER IOWA INTO MINNESOTA AND EVENTUALLY WI. THE H85 THERMAL RIDGE IS OVER THE FORECAST AREA. BY 12Z SUNDAY THE GFS/NAM/EC ARE SIMILAR AND HAVE THE SURFACE LOW OVER NORTHEAST NEBRASKA WITH A FRONT OVER FAR EASTERN NEBRASKA INTO WESTERN IOWA. THIS BOUNDARY IS EAST OF THE AREA BY 18Z. WITH THE LONGWAVE TROF STILL MOVING THROUGH THE AREA...THERE WILL STILL BE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY NIGHT AND SUNDAY MORESO IN SOUTHEAST NEBRASKA. NORTHWEST WINDS BEHIND THE FRONT TURN WINDY 15 TO 25KTS AT THE SURFACE WITH 40 TO 50KTS AT H85. THE MOISTURE DRIES OUT TO .5-.75 PWAT BY 00Z AND 0.25 OF AN INCH PWAT BY 12Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 318 AM CDT FRI APR 17 2015 THE CLOSED MID TROPOSPHERIC LOW OVER THE UPPER MISSISSIPPI VALLEY MONDAY...SHIFTS TO THE UPPER GREAT LAKES TUESDAY...AND LINGERS THERE THROUGH THURSDAY. IT SHOULD BE DRY SUNDAY NIGHT THROUGH TUESDAY. HIGHS SHOULD BE IN THE 50S AND 60S. THE GFS IS SLIGHTLY FARTHER NORTH WITH LOW...AND THIS ALLOWS A STORM SYSTEM THAT MOVES INTO THE WESTERN U.S. TO AFFECT THE LOCAL AREA WITH SHOWERS AND ISOLATED THUNDERSTORMS WEDNESDAY INTO THE REST OF THE WEEK. THE EC IS MAINLY DRY THRU THURSDAY. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1158 AM CDT FRI APR 17 2015 VFR CONDITIONS ARE EXPECTED THROUGH TODAY...WITH CEILINGS AROUND 5-8KFT. LATE AFTERNOON TO EVENING...INCREASING COVERAGE OF SHOWERS WILL BRING AT LEAST A VICINITY THREAT TO KOFK AND KLNK...WITH MORE WIDESPREAD POTENTIAL AFTER 02Z. ANY SHOWERS AFFECTING TAF SITES MAY BRING THUNDER...AS WELL AS VIS AND POSSIBLY EVEN CIGS INTO MVFR RANGE. HAVE JUST MENTIONED THE SHOWERS AND VIS RESTRICTIONS FOR NOW...WITH TIME YET TO MODIFY AS TIMING OF SHOWERS BECOMES MORE EVIDENT. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT/ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
332 AM CDT FRI APR 17 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 318 AM CDT FRI APR 17 2015 PCPN CHANCES AND TEMPERATURES ARE THE PRIMARY FORECAST CONCERNS IN THE TODAY PERIOD...THEN CONTINUED SHOWER/THUNDERSTORM CHANCES ESPECIALLY FRIDAY NIGHT THROUGH SATURDAY NIGHT...THEN THE COLD FRONTAL PASSAGE AND PRECIPITATION ENDING SUNDAY. REGIONAL RADAR EARLY THIS MORNING SHOWS AREA OF SHOWERS AND ISOLATED THUNDERSTORMS PIVOTING NORTH TO NORTHWEST FROM KANSAS INTO NEBRASKA AROUND CLOSED UPPER LOW OVER SOUTH CENTRAL COLORADO. WESTERN PORTIONS OF THE FORECAST AREA WILL BE MOST LIKELY TO SEE PRECIP TODAY WITH EASTERN AREAS HAVING TO WAIT UNTIL THE AFTERNOON FOR BETTER POPS AS THE UPPER LOW TRACKS SLOWLY EAST. RAP FORECAST SOUNDINGS SHOW LIMITED INSTABILITY THROUGH MOST OF THE DAY ESPECIALLY IN THE EAST AND NORTH WITH INCREASING INSTABILITY IN WESTERN PARTS OF THE AREA ALONG AND WEST OF A BEATRICE-LINCOLN- COLUMBUS ARC BY LATE AFTERNOON. CLOUD COVER IS EXPECTED TO REMAIN IN PLACE MUCH OF THE DAY FOR THE WEST HALF OF THE AREA WITH VARIABLE SKY COVER IN THE EAST HALF. THIS SPLIT SHOULD SEE LOWER TEMPS AROUND 70 CONFINED TO THE WEST WITH MID 70S IN THE EAST WHERE SOME PERIODS OF SUN ARE POSSIBLE. TONIGHT...THE OPERATIONAL MODELS ARE IN GOOD AGREEMENT THAT THE CLOSED H5 LOW OVER THE FOUR-CORNERS REGION WILL LIFT NORTHEAST TO COLORADO BY 00Z TONIGHT. THE H5 LOW MEANDERS OVER COLORADO THROUGH SATURDAY...THEN DRIFTS INTO WESTERN KANSAS BY 06Z. THE NAM IS SLIGHTLY DIFFERENT IN SPLITTING SOME OF THE H5 ENERGY TO THE NORTH IN SOUTH DAKOTA AND THE CLOSED LOW A LITTLE FARTHER SOUTH TOWARD OKLAHOMA. SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING OVER PARTS OF THE CWA AND WILL CONTINUE TO SPREAD NORTH AND EAST FRIDAY NIGHT AND SATURDAY. THESE PERIODS WILL HAVE THE HIGHEST POPS THIS WEEKEND. THE INSTABILITY AXIS DOES LIFT NORTHWARD FRIDAY NIGHT AND CONTINUES OVER THE AREA SATURDAY. THERE IS ALSO AN H85 BOUNDARY IN THIS REGION THAT LIFTS NORTH AND MAY PROVIDE A FOCUS FOR ENHANCED CONVECTIVE ACTIVITY. SOME .25-.5 INCH RAINS FELL ALONG WITH PEA TO DIME- SIZED HAIL WAS REPORTED WITH SOME OF THE STORMS IN SOUTHERN NEBRASKA THURSDAY NIGHT. FORECAST SOUNDINGS SHOW WEAK INSTABILITY WITH MLCAPE OF 200J/KG FRIDAY NIGHT...AND A LITTLE BETTER INSTABILITY WITH MLCAPE OF 500J/KG SATURDAY. SOME OF THE STRONGER STORMS MAY PRODUCE SOME HAIL. RAINFALL AMOUNTS THROUGH SATURDAY COULD RANGE FROM .5 TO 1 INCH. SATURDAY NIGHT...THE MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED TO SHIFT FARTHER EAST INTO IOWA AND EXTEND IN A LARGE AREA FROM THE GULF STATES THROUGH THE MISSISSIPPI VALLEY INTO MINNESOTA AND THE DAKOTA. THE LOW LEVEL JET OF 40-50KTS DEVELOPS OVER IOWA INTO MINNESOTA AND EVENTUALLY WI. THE H85 THERMAL RIDGE IS OVER THE FORECAST AREA. BY 12Z SUNDAY THE GFS/NAM/EC ARE SIMILAR AND HAVE THE SURFACE LOW OVER NORTHEAST NEBRASKA WITH A FRONT OVER FAR EASTERN NEBRASKA INTO WESTERN IOWA. THIS BOUNDARY IS EAST OF THE AREA BY 18Z. WITH THE LONGWAVE TROF STILL MOVING THROUGH THE AREA...THERE WILL STILL BE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY NIGHT AND SUNDAY MORESO IN SOUTHEAST NEBRASKA. NORTHWEST WINDS BEHIND THE FRONT TURN WINDY 15 TO 25KTS AT THE SURFACE WITH 40 TO 50KTS AT H85. THE MOISTURE DRIES OUT TO .5-.75 PWAT BY 00Z AND 0.25 OF AN INCH PWAT BY 12Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 318 AM CDT FRI APR 17 2015 THE CLOSED MID TROPOSPHERIC LOW OVER THE UPPER MISSISSIPPI VALLEY MONDAY...SHIFTS TO THE UPPER GREAT LAKES TUESDAY...AND LINGERS THERE THROUGH THURSDAY. IT SHOULD BE DRY SUNDAY NIGHT THROUGH TUESDAY. HIGHS SHOULD BE IN THE 50S AND 60S. THE GFS IS SLIGHTLY FARTHER NORTH WITH LOW...AND THIS ALLOWS A STORM SYSTEM THAT MOVES INTO THE WESTERN U.S. TO AFFECT THE LOCAL AREA WITH SHOWERS AND ISOLATED THUNDERSTORMS WEDNESDAY INTO THE REST OF THE WEEK. THE EC IS MAINLY DRY THRU THURSDAY. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1149 PM CDT THU APR 16 2015 SCT SHRA MAY AFFECT THE KLNK TAF OVER THE NEXT COUPLE OF HOURS BUT THIS PRECIP WILL HAVE A HARD TIME MOVING NWD TOWARD THE KOMA TAF DUE TO HIGHER STABILITY. SOME OF THIS -RA MAY MOVE INTO KOFK TOWARD MRNG AND WILL INCLUDE A TEMPO GROUP THERE FOR A COUPLE HOURS. MOST OF FRI SHOULD BE DRY FOR THE TAFS WITH A SCT-BKN MID LEVEL CLOUD DECK AND LIGHT WINDS. SCT SHRA MAY AGAIN DVLP FRI EVNG /ESPECIALLY FOR KOFK-KLNK THRU 06Z/ WITH AN EVEN BETTER CHANCE OF PRECIP AT ALL THE TAF SITES JUST AFTER THIS PERIOD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT/ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
144 PM EDT FRI APR 17 2015 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS CENTRAL NEW YORK EARLY THIS AFTERNOON AND NORTHEAST PENNSYLVANIA BY LATE AFTERNOON. THIS FRONT WILL TRIGGER A FEW SHOWERS WITH AN ISOLATED THUNDERSTORM IN NORTHEAST PENNSYLVANIA. ANOTHER COLD FRONT WILL PASS ACROSS THE REGION SATURDAY. THIS FRONT COULD TRIGGER SOME SHOWERS IN NORTHERN AND EASTERN NEW YORK WITH MAINLY DRY WEATHER IN CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA. HIGH PRESSURE AND COOLER WEATHER WILL BUILD ACROSS THE REGION FOR SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATER VAPOR IMAGERY SHOWS A SHORT WAVE MOVING ACROSS THE EASTERN GREAT LAKES AND EASTERN OHIO VALLEY THIS MORNING. THIS WAVE WILL PUSH A WEAK FRONT ACROSS THE REGION THIS AFTERNOON WITH SOME LL DRY ADVECTION BEHIND THE FRNT. THE FRONT AND LIFT ASSCTD WITH THE SHRT WAVE WILL TRIGGER ISLD TO SCT SHRA ACRS C NY/NE PA THIS AFTERNOON. THE FRNT COMES THRU AT MAX HEATING LATE THIS AFTERNOON ESP IN NE PA. CAPES ON THE HI RES MODELS NOW ARE RANGING FROM ARND 250 TO 500 J/KG IN NE PA ARND 21Z WITH THE HIGHER RESOLUTION MODELS SHOWING SCT CONVECTIVE CELLS FORMING ON SIMULATED RADAR FIELDS. THE BULK SHEAR IS ARND 20 KNOTS 0-1 KM AND 0-3 KM AND ABT 35 KNOTS 0-6 KM. FORCING IS NOT STRG BUT I HAVE ADDED ISLD TSRA TO NE PA GRIDS. I MAY HAVE TO ADJUST THIS UP EVEN MORE AS RECENT RAP AND HRRR RUNS HAVE MORE CAPE. WILL CONT TO MONITOR. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... NW FLOW ALOFT TNGT WITH WEAK SFC FEATURES WILL RESULT IN A QUIET PD WITH LGT WINDS AND BKN CLDS. WHILE A SHWR CAN/T BE RULED OUT...NOT ENUF OF A CHANCE TO INCLUDE IN THE FCST ATTM. SATURDAY WILL SEE A SHRT WV PASSING THRU NRN NEW ENG AND SOME LATE DAY CAA IN THE WAKE OF THE WV. MODELS SHOW VERY DRY AIR OVER THE AREA WITH THE BEST FRCG STAYING TO THE NE. SOME INSTABILITY LIKELY WITH THE LWRD HGTS BUT DRY AIR SHD INHIBIT ANY SHWRS FROM FRMG IN THE FCST AREA...ALTHOUGH NRN ONEIDA WILL BE CLOSE. UPR RDGG OVER THE GREAT LAKES WILL ALLOW SFC HIPRES TO SLIDE INTO THE AREA ON SUNDAY. TEMPS WILL BE A BIT LWR WITH THE CAA BUT DRIER AIR SHD ALLOW FOR MSTLY SUNNY SKIES. && .LONG TERM /MONDAY THROUGH FRIDAY/... 0245 AM UPDATE...ONLY MADE A FEW ADJUSTMENTS TO PREVIOUS FORECAST MADE DURING THE DAY SHIFT THURSDAY. MAIN CHANGE WAS TO ADJUST HIGH TEMPS DOWN FOR MONDAY, WEDNESDAY, AND THURSDAY OF NEXT WEEK AS GUIDANCE CONTINUES TO INDICATE WE WILL BE COOLER AND MORE UNSETTLED UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH. 445 PM THURSDAY UPDATE... MODELS IN GOOD AGREEMENT ON MOIST OCCLUDED FRONT LIKELY TO BRING RAIN AS IT SWEEPS THROUGH THE REGION LATE SUNDAY NIGHT THROUGH MONDAY. SHOWALTER INDICES ONLY GET TO AROUND ZERO...SHOWING ONLY SMALLEST HINT OF ELEVATED INSTABILITY...SO CHANCE OF EMBEDDED THUNDER DURING THAT PERIOD LOOKS MINIMAL TO NONE. QUARTER TO HALF INCH OF RAIN LOOKS QUITE DOABLE HOWEVER. CUTOFF LOW CURRENTLY OVER FOUR CORNERS REGION...IS DEPICTED BY GFS-ECMWF TO MERGE WITH A DIGGING NORTHERN STREAM TROUGH OVER THE MIDWEST THIS WEEKEND. THOSE FEATURES WILL COMBINE INTO A NEW LARGER CUTOFF LOW...THE CENTER OF WHICH WILL SLOWLY SLOG ITS WAY OVER THE WESTERN GREAT LAKES NEXT WEEK. THIS UPPER LOW WILL HAVE A LARGE FOOTPRINT WITH DISTURBANCES-WAVES ROTATING AROUND IT ACROSS GREAT LAKES TO NORTHEAST. MODELS DISAGREE ON LOCATION OF UPPER LOW CENTER BY THURSDAY /EITHER CENTRAL GREAT LAKES AND HEADING EAST...OR A BIT FURTHER NORTH AND STILL PARKED/ YET EITHER WAY IT LOOKS RATHER TROUGHY AND UNSETTLED WITH CYCLONIC FLOW OVER OUR REGION. SO AFTER BRIEFLY MILDER CONDITIONS TUESDAY...WE SHOULD TREND BACK TO NEAR CLIMATOLOGY FOR TEMPERATURES WEDNESDAY-THURSDAY. IF THE UPPER LOW SHIFTS EAST AS PER ECMWF...POSSIBLY A LITTLE COOLER THAN CLIMATOLOGY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SFC TROF IS MOVING THROUGH NRN PA AT 18Z WITH LOW LEVEL DRY AIR ADVECTION BEHIND BOUNDARY. MVFR/LOW MVFR CIGS WILL IMPROVE TO VFR BY LATE AFTERNOON WITH SKIES EXPECTED TO CLEAR EARLY THIS EVENING. PATCHY FOG IS POSSIBLE OVERNIGHT DUE TO LIGHT WINDS AND WET GROUND BUT MIST IS ONLY INCLUDED IN THE KRME TAF BETWEEN 09Z-13Z DUE TO LIGHT EASTERLY FLOW. ON SATURDAY JUST SCT CLOUDS AROUND 4K FT. W/NW WINDS AROUND 10 KNOTS BECOMING LIGHT AND VARIABLE THIS EVENING THEN NW ON SATURDAY AT 10-15 KNOTS WITH GUSTS AROUND 25 KNOTS. .OUTLOOK... SAT NIGHT THRU SUN...VFR. SUN NGT-WED...RESTRICTIONS IN -RA...ESP. SUN NGT-MON NGT. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJN NEAR TERM...DJN SHORT TERM...DGM LONG TERM...MDP/PCF AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1045 AM EDT FRI APR 17 2015 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS CENTRAL NEW YORK EARLY THIS AFTERNOON AND NORTHEAST PENNSYLVANIA BY LATE AFTERNOON. THIS FRONT WILL TRIGGER A FEW SHOWERS WITH AN ISOLATED THUNDERSTORM IN NORTHEAST PENNSYLVANIA. ANOTHER COLD FRONT WILL PASS ACROSS THE REGION SATURDAY. THIS FRONT COULD TRIGGER SOME SHOWERS IN NORTHERN AND EASTERN NEW YORK WITH MAINLY DRY WEATHER IN CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA. HIGH PRESSURE AND COOLER WEATHER WILL BUILD ACROSS THE REGION FOR SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATER VAPOR IMAGERY SHOWS A SHORT WAVE MOVING ACROSS THE EASTERN GREAT LAKES AND EASTERN OHIO VALLEY THIS MORNING. THIS WAVE WILL PUSH A WEAK FRONT ACROSS THE REGION THIS AFTERNOON WITH SOME LL DRY ADVECTION BEHIND THE FRNT. THE FRONT AND LIFT ASSCTD WITH THE SHRT WAVE WILL TRIGGER ISLD TO SCT SHRA ACRS C NY/NE PA THIS AFTERNOON. THE FRNT COMES THRU AT MAX HEATING LATE THIS AFTERNOON ESP IN NE PA. CAPES ON THE HI RES MODELS NOW ARE RANGING FROM ARND 250 TO 500 J/KG IN NE PA ARND 21Z WITH THE HIGHER RESOLUTION MODELS SHOWING SCT CONVECTIVE CELLS FORMING ON SIMULATED RADAR FIELDS. THE BULK SHEAR IS ARND 20 KNOTS 0-1 KM AND 0-3 KM AND ABT 35 KNOTS 0-6 KM. FORCING IS NOT STRG BUT I HAVE ADDED ISLD TSRA TO NE PA GRIDS. I MAY HAVE TO ADJUST THIS UP EVEN MORE AS RECENT RAP AND HRRR RUNS HAVE MORE CAPE. WILL CONT TO MONITOR. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... NW FLOW ALOFT TNGT WITH WEAK SFC FEATURES WILL RESULT IN A QUIET PD WITH LGT WINDS AND BKN CLDS. WHILE A SHWR CAN/T BE RULED OUT...NOT ENUF OF A CHANCE TO INCLUDE IN THE FCST ATTM. SATURDAY WILL SEE A SHRT WV PASSING THRU NRN NEW ENG AND SOME LATE DAY CAA IN THE WAKE OF THE WV. MODELS SHOW VERY DRY AIR OVER THE AREA WITH THE BEST FRCG STAYING TO THE NE. SOME INSTABILITY LIKELY WITH THE LWRD HGTS BUT DRY AIR SHD INHIBIT ANY SHWRS FROM FRMG IN THE FCST AREA...ALTHOUGH NRN ONEIDA WILL BE CLOSE. UPR RDGG OVER THE GREAT LAKES WILL ALLOW SFC HIPRES TO SLIDE INTO THE AREA ON SUNDAY. TEMPS WILL BE A BIT LWR WITH THE CAA BUT DRIER AIR SHD ALLOW FOR MSTLY SUNNY SKIES. && .LONG TERM /MONDAY THROUGH THURSDAY/... 0245 AM UPDATE...ONLY MADE A FEW ADJUSTMENTS TO PREVIOUS FORECAST MADE DURING THE DAY SHIFT THURSDAY. MAIN CHANGE WAS TO ADJUST HIGH TEMPS DOWN FOR MONDAY, WEDNESDAY, AND THURSDAY OF NEXT WEEK AS GUIDANCE CONTINUES TO INDICATE WE WILL BE COOLER AND MORE UNSETTLED UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH. 445 PM THURSDAY UPDATE... MODELS IN GOOD AGREEMENT ON MOIST OCCLUDED FRONT LIKELY TO BRING RAIN AS IT SWEEPS THROUGH THE REGION LATE SUNDAY NIGHT THROUGH MONDAY. SHOWALTER INDICES ONLY GET TO AROUND ZERO...SHOWING ONLY SMALLEST HINT OF ELEVATED INSTABILITY...SO CHANCE OF EMBEDDED THUNDER DURING THAT PERIOD LOOKS MINIMAL TO NONE. QUARTER TO HALF INCH OF RAIN LOOKS QUITE DOABLE HOWEVER. CUTOFF LOW CURRENTLY OVER FOUR CORNERS REGION...IS DEPICTED BY GFS-ECMWF TO MERGE WITH A DIGGING NORTHERN STREAM TROUGH OVER THE MIDWEST THIS WEEKEND. THOSE FEATURES WILL COMBINE INTO A NEW LARGER CUTOFF LOW...THE CENTER OF WHICH WILL SLOWLY SLOG ITS WAY OVER THE WESTERN GREAT LAKES NEXT WEEK. THIS UPPER LOW WILL HAVE A LARGE FOOTPRINT WITH DISTURBANCES-WAVES ROTATING AROUND IT ACROSS GREAT LAKES TO NORTHEAST. MODELS DISAGREE ON LOCATION OF UPPER LOW CENTER BY THURSDAY /EITHER CENTRAL GREAT LAKES AND HEADING EAST...OR A BIT FURTHER NORTH AND STILL PARKED/ YET EITHER WAY IT LOOKS RATHER TROUGHY AND UNSETTLED WITH CYCLONIC FLOW OVER OUR REGION. SO AFTER BRIEFLY MILDER CONDITIONS TUESDAY...WE SHOULD TREND BACK TO NEAR CLIMATOLOGY FOR TEMPERATURES WEDNESDAY-THURSDAY. IF THE UPPER LOW SHIFTS EAST AS PER ECMWF...POSSIBLY A LITTLE COOLER THAN CLIMATOLOGY. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... 12Z UPDATE... SHOWERS WILL CONTINUE DIMINISHING OVER THE AREA FROM WEST TO EAST THIS MORNING HOWEVER STILL EXPECTING AT LEAST MVFR FUEL ALT CONDITIONS FOR MOST SITES UNTIL THIS AFTERNOON DUE TO LOW CIGS. FOR KBGM, CIGS WILL LIKELY DROP AT TIMES TO HIGH END IFR THIS MORNING WITH IFR VISBYS LIKELY AT TIMES FOR KRME. CONDITIONS IMPROVE TO VFR AT ALL SITES THIS AFTERNOON WITH SKIES CLEARING OUT TONIGHT. WINDS WILL GENERALLY BE W/SW AROUND 5 KNOTS EARLY THIS MORNING BECOMING W/NW 5 TO 10 KNOTS BY THIS AFTERNOON. .OUTLOOK... SAT THRU SUN...VFR. SUN NGT-MON-TUE...RESTRICTIONS IN -RA...ESP. SUN NGT-MON. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJN NEAR TERM...DJN SHORT TERM...DGM LONG TERM...MDP/PCF AVIATION...PCF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1027 AM EDT FRI APR 17 2015 .SYNOPSIS... A WEAK PRESSURE PATTERN WILL CONTINUE TO BRING MOSTLY CLOUDY SKIES AND DRIZZLY CONDITIONS TODAY. SOME IMPROVEMENT CAN BE EXPECTED SATURDAY AND SUNDAY. A WARM FRONT BRING ANOTHER GOOD CHANCE OF RAIN LATER SUNDAY. NEXT WEEK LOOKS TO BE DRY AND SEASONABLE. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...LIGHT SHOWERS AND DRIZZLE CONTINUE ACROSS THE AREA THIS MORNING. SOME OF THE ACTIVITY NEAR WILMINGTON HAS BEEN A LITTLE HEAVIER. HRRR AND LATEST NAM SHOW A CONVECTIVE SIGNAL IN THEIR RESPECTIVE MODELS WHICH SHOW SHOWERS INCREASING THIS AFTERNOON. WILL MAINTAIN LOW CHANCE POPS AREAWIDE. FORECAST EMPHASIS THEN SHIFTS TO POSSIBLE OVERNIGHT ACTIVITY WITH THE SHORTWAVE IN THE TENNESSEE VALLEY. THE LATEST NAM IS A LITTLE LESS ROBUST BUT WILL WAIT UNTIL THE 1200 UTC GFS ARRIVES TO MAKE ANY CHANGES. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...THE FORECAST AREA WILL BE UNDER THE CONTROL OF NEARLY A FULL LATITUDE AMPLIFIED UPPER RIDGE THIS PERIOD. THE ROUGHLY NORTH TO SOUTH UPPER RIDGE AXIS WILL REMAIN WEST OF THE ILM CWA DURING SAT. WITH WEAK HIGH PRESSURE AT THE SFC AND MAINLY SUBSIDENCE ALOFT...THE CHANCE FOR CONVECTION HAS BEEN KEPT TO A MINIMUM AND WILL ONLY INDICATE SEA BREEZE INDUCED CONVECTION. THE UPPER RIDGE AXIS WILL DRIFT TO THE EAST AND ACROSS THE ILM CWA SAT NIGHT...AND FINALLY OFF THE CAROLINA COASTS SUN THRU SUN NIGHT. MODELS ARE IN DECENT AGREEMENT WITH THIS SCENARIO PANNING OUT. A POTENT S/W MID-LEVEL TROF OR ONE COULD CALL IT A CLIPPER...WILL DIVE SE AND RACE ACROSS THE NE STATES SAT...AND OFFSHORE FROM NEW ENGLAND BY SUNDAY. THE SFC COLD FRONT ASSOCIATED WITH THIS CLIPPER WILL BACKDOOR THE ILM CWA ON SUN FOLLOWED BY A WEDGE OF HIGH PRESSURE FROM THE NORTH THRU SUN NIGHT. POPS WILL BE ON THE LOW SIDE IF ANY WITH THIS FRONTAL PASSAGE. THE CENTRAL U.S. CUTOFF LOW IS PROGGED TO OPEN UP AND HOOK ONTO A S/W UPPER TROF DIVING OUT OF CENTRAL CANADA BY THE END OF THIS PERIOD. LOOK FOR AN AMPLIFYING PATTERN ALOFT WITH THE FA COMING UNDER THE INFLUENCE OF THE FULL LATITUDE UPPER TROF ACROSS THE CENTRAL U.S. BY LATE SUN. WITH SW FLOW ALOFT...GULF OF MEXICO MOISTURE WILL BECOME WELL TAPPED BY MID TO LATE SUN. A S/W MID- LEVEL TROF ROTATING THRU THE WELL AMPLIFIED UPPER PATTERN...WILL PUSH ACROSS THE FA BY LATE SUN INTO EARLY MON. THE DYNAMICS ASSOCIATED WITH IT AND THE STALLED SFC BOUNDARY IN THE VICINITY... WILL BE ENOUGH TO INCREASE POPS TO LIKELY OR POSSIBLY CATEGORICAL...BY AND DURING SUN NIGHT ACROSS THE ENTIRE ILM CWA. AS FOR TEMPS THIS PERIOD...WILL GO WITH AT OR SLIGHTLY ABOVE CLIMO WHICH IS BASICALLY 70S TO AROUND 80 FOR HIGHS...AND 50S TO AROUND 60 FOR LOWS. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...A WELL AMPLIFIED LONGWAVE UPPER PATTERN TO BECOME ESTABLISHED THIS PERIOD. THE ILM CWA WILL PRIMARILY BE UNDER THE INFLUENCED OF NEARLY A FULL LATITUDE UPPER TROF...WITH THE UPPER TROF N-S AXIS REMAINING WEST OF THE ILM CWA THIS PERIOD. ITS ONLY TOWARD THE END OF THE LONG TERM PERIOD WHEN MODELS WANT TO FLATTEN THIS AMPLIFIED FLOW...WITH MODELS DIVERGING FROM ONE ANOTHER FOR THEIR RESPECTIVE SOLUTIONS BY THE MID-LATE WEEK PERIOD OF NEXT WEEK. AS FOR POPS...THE PCPN FROM SUN NIGHT WILL EXTEND INTO EARLY MON BEFORE MOVING OFF TO THE NE. A COLD FRONT WILL APPROACH AND PUSH ACROSS THE ILM CWA MON NIGHT INTO TUE...WITH IDLEST CHANCE POPS BEING ADVERTISED. WEAK HIGH PRESSURE WILL FOLLOW FROM THE GULF COAST STATES TUE THRU MUCH OF THE MID-WEEK PERIOD OF NEXT WEEK. THIS COULD END UP FINALLY BEING A PERIOD OF DRYING OUT ACROSS THE ILM CWA. AS FOR MAX/MIN TEMPS THIS PERIOD...STAYED AT OR SLIGHTLY HIGHER THAN CLIMO FOR THIS TIME OF THE YEAR. DO NOT SEE ANY INFLUENCE OF COOL OR COLDER THAN NORMAL AIR MASSES AFFECTING THE ILM CWA DURING THIS TIME PERIOD. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...LOW PRESSURE REMAINS OFFSHORE...WITH SMALL POCKETS OF LIGHT SHOWERS MOVING ONSHORE. MOST OF THE SHOWERS WILL REMAIN AWAY FROM THE TERMINALS...BUT A SMALL SHOWER IS NOT OUT OF THE QUESTION. NORTHEAST FLOW IS EXPECTED TO CONTINUE TODAY...WITH MAINLY MVFR CEILINGS. TONIGHT...A MORE ORGANIZED SHORT WAVE WILL MOVE WEST TO EAST ACROSS THE REGION...WITH MORE ORGANIZED PRECIPITATION EXPECTED. CEILINGS MAY LOWER TO IFR...BUT WILL KEEP PREDOMINATELY MVFR AT THIS TIME. EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS MOVING BACK INTO THE REGION LATE SATURDAY NIGHT THROUGH MONDAY MORNING. BECOMING VFR MONDAY AFTERNOON THROUGH TUE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...WINDS AND SEAS ON THE WAY DOWN THIS MORNING WITH JMPN7 REPORTING EIGHT KNOTS FROM THE NORTHEAST. SEAS AT 41110 NOW BELOW FIVE FEET. FORECAST LOOKS GOOD WITH HEADLINES EXPIRING AS THE DAY PROCEDES. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SATURDAY TO START OFF WITH A WEAK SFC PRESSURE PATTERN AND GRADIENT. BY THE END OF THE DAY AND DURING SAT NIGHT...A BACKDOOR CUP IS EXPECTED TO OCCUR. IMMEDIATELY FOLLOWING THE CUP...A WEDGE OF HIGH PRESSURE WILL NOSE DOWN FROM SE CANADA AND THE NE STATES SAT NIGHT THRU SUN. THE SFC PRESSURE GRADIENT WILL TIGHTEN FOR THE REMAINDER OF THE SHORT TERM PERIOD WITH NE WINDS REACHING SCEC OR POSSIBLY SCA THRESHOLDS LATE SAT INTO EARLY SUN. A COASTAL FRONT/TROF WILL DEVELOP AND BECOME ESTABLISHED JUST OFFSHORE BY LATE SUN...BEFORE FINALLY LIFTING INLAND AND NORTHWARD AT THE SAME TIME SUN NIGHT. WINDS WILL VEER TO THE E THEN SE BY LATE SUN. THE SFC PG WILL FURTHER TIGHTEN AND COULD SEE WINDS AGAIN REACH SCEC/SCA THRESHOLDS. THE ONSHORE FLOW WILL CAPITALIZE ON A DECENT FETCH RESULTING IN SIGNIFICANT SEAS BUILDING FROM LATE SAT THRU SUN NIGHT...AND LIKELY REACHING SCA THRESHOLDS. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...COULD ARGUE THAT A SFC WARM FRONT WILL HAVE PUSHED NORTHEAST OF THE LOCAL ILM WATERS COME MONDAY MORNING. THUS THE STRONG SE-S WINDS WILL VEER TO THE SW AT REDUCED SPEEDS AS THE SFC PG RELAXES SOME. THIS WILL BE SHORT-LIVED AS THE GRADIENT ROOTEDNESS AGAIN AHEAD OF THE APPROACHING COLD FRONT...WHICH IS PROGGED TO PUSH ACROSS THE LOCAL WATERS BY DAYBREAK TUE. WINDS OVER THE WATERS WILL FURTHER VEER TO THE W-NW AS RIDGING FROM WEAK SFC HIGH CENTERED OVER THE GULF COAST STATES AFFECTS THE LOCAL WATERS ON TUESDAY. MODELS NOW INDICATE A SECONDARY SFC COLD FRONT OR SFC TROF TO PUSH ACROSS THE LOCAL WATERS TUE NIGHT...WHICH WILL FURTHER VEER THE WINDS TO THE NW-N. SCEC OR SCA THRESHOLDS WILL REMAIN POSSIBLE AT THE START OF THIS PERIOD...FADING QUICKLY BY LATE TUE NIGHT. SIGNIFICANT SEAS WILL PEAK DURING MONDAY...THAN WILL INDICATE A SUBSIDING TREND THERE- AFTER AS WINDS VEER TO EVENTUALLY AN OFFSHORE TRAJECTORY BY LATE TUE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR AMZ254-256. SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ250- 252. && $$ SYNOPSIS...SHK NEAR TERM...SHK SHORT TERM...DCH LONG TERM...DCH AVIATION...HDL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
955 PM CDT SAT APR 18 2015 .UPDATE... ISSUED AT 955 PM CDT SAT APR 18 2015 ALTHOUGH THE 01 UTC RAP/HRRR ARE OVERDOING THE QPF IN MOST AREAS...THEY HAVE A GOOD HANDLE ON THE AREA OF PRECIPITATION AND HAVE UTILIZED THIS BLEND FOR POPS THROUGH THE NIGHT AND INTO SUNDAY. BEST PRECIPITATION CHANCES WILL REMAIN OVER THE SOUTHEAST FORECAST AREA. EXPECT PRECIPITATION TO FILL IN OVER THE JAMES RIVER VALLEY OVER THE NEXT FEW HOURS. PRECIPITATION BAND FROM SOUTHWEST INTO NORTH CENTRAL NORTH DAKOTA WILL MOVE ACROSS CENTRAL NORTH DAKOTA AS WELL...WITH BEST PRECIPITATION CHANCES OVER BISMARCK THROUGH AROUND MIDNIGHT. PRECIPITATION IS EXPECTED TO MOVE OUT OF THE JAMES RIVER VALLEY AROUND 12-14Z...LOWERED POPS ACROSS THE AREA EARLY MORNING...THEN BUMPED THEM UP MID TO LATE MORNING INTO THE AFTERNOON AS WRAP AROUND MOISTURE MOVES INTO THE AREA ON THE BACK SIDE OF THE EXITING SYSTEM. UPDATE ISSUED AT |748 PM CDT SAT APR 18 2015 QUICK UPDATE FOR POPS BASED ON LATEST RADAR...ALSO REMOVED THUNDER OVER THE SOUTHWEST. HEAVIEST SHOWERS LOOK TO REMAIN OVER THE FAR SOUTH CENTRAL AND INTO EASTERN NORTH DAKOTA THIS EVENING. BAND MOVING EAST ACROSS THE CENTRAL FROM AROUND MINOT TO GARRISON TO HEBRON SHOULD HELP MOISTEN THE ATMOSPHERE NEAR KBIS THIS EVENING. SHOWERS IN THE FAR SOUTH CENTRAL MOVING TOWARD BISMARCK ARE NOW DISSIPATING ON THE NORTHERN FRINGE. 19 APRIL 00 UTC SOUNDING STILL SHOWS QUITE A BIT OF DRY AIR BELOW THE MID AND UPPER LEVEL MOISTURE BEGINNING AROUND 10K FEET. UPDATE ISSUED AT 638 PM CDT SAT APR 18 2015 UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES FROM THE GOING FORECAST. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM FORECAST. AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA. AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY THROUGH THE REMAINDER OF THE WEEK. AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES. THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS RELATIVE HUMIDITY DROPS BELOW 20 PERCENT. THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA. WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 955 PM CDT SAT APR 18 2015 A COLD FRONT FROM NORTH CENTRAL INTO WESTERN NORTH DAKOTA THIS EVENING WILL MOVE ACROSS THE CENTRAL THIS EVENING AND MERGE WITH A LOW DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT. SCATTERED RAIN SHOWERS ARE EXPECTED TO MOVE FROM WESTERN INTO CENTRAL NORTH DAKOTA THIS EVENING...AND BECOME MORE WIDESPREAD AS THEY MERGE WITH SHOWERS MOVING IN FROM THE SOUTH. EMBEDDED MVFR CONDITIONS POSSIBLE IN RAIN. && .FIRE WEATHER... ISSUED AT 315 PM CDT SAT APR 18 2015 CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...AYD LONG TERM...AJ AVIATION...TWH FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
748 PM CDT SAT APR 18 2015 .UPDATE... ISSUED AT |748 PM CDT SAT APR 18 2015 QUICK UPDATE FOR POPS BASED ON LATEST RADAR...ALSO REMOVED THUNDER OVER THE SOUTHWEST. HEAVIEST SHOWERS LOOK TO REMAIN OVER THE FAR SOUTH CENTRAL AND INTO EASTERN NORTH DAKOTA THIS EVENING. BAND MOVING EAST ACROSS THE CENTRAL FROM AROUND MINOT TO GARRISON TO HEBRON SHOULD HELP MOISTEN THE ATMOSPHERE NEAR KBIS THIS EVENING. SHOWERS IN THE FAR SOUTH CENTRAL MOVING TOWARD BISMARCK ARE NOW DISSIPATING ON THE NORTHERN FRINGE. 19 APRIL 00 UTC SOUNDING STILL SHOWS QUITE A BIT OF DRY AIR BELOW THE MID AND UPPER LEVEL MOISTURE BEGINNING AROUND 10K FEET. UPDATE ISSUED AT 638 PM CDT SAT APR 18 2015 UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES FROM THE GOING FORECAST. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM FORECAST. AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA. AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY THROUGH THE REMAINDER OF THE WEEK. AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES. THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS RELATIVE HUMIDITY DROPS BELOW 20 PERCENT. THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA. WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 748 PM CDT SAT APR 18 2015 A COLD FRONT FROM NORTH CENTRAL INTO WESTERN NORTH DAKOTA EARLY THIS EVENING WILL MOVE ACROSS THE CENTRAL THIS EVENING AND MERGE WITH A LOW DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT. SCATTERED RAIN SHOWERS ARE EXPECTED TO MOVE FROM WESTERN INTO CENTRAL NORTH DAKOTA THIS EVENING...AND BECOME MORE WIDESPREAD AS THEY MERGE WITH SHOWERS MOVING IN FROM THE SOUTH. EMBEDDED MVFR CONDITIONS POSSIBLE IN RAIN. && .FIRE WEATHER... ISSUED AT 315 PM CDT SAT APR 18 2015 CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...AYD LONG TERM...AJ AVIATION...TWH FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 PM CDT SAT APR 18 2015 .UPDATE... ISSUED AT 638 PM CDT SAT APR 18 2015 UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES FROM THE GOING FORECAST. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM FORECAST. AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA. AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY THROUGH THE REMAINDER OF THE WEEK. AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES. THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS RELATIVE HUMIDITY DROPS BELOW 20 PERCENT. THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA. WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 638 PM CDT SAT APR 18 2015 A COLD FRONT FROM NORTH CENTRAL INTO WESTERN NORTH DAKOTA EARLY THIS EVENING WILL MOVE ACROSS THE CENTRAL THIS EVENING AND MERGE WITH A LOW DEVELOPING ACROSS EASTERN SOUTH DAKOTA TONIGHT. SCATTERED RAIN SHOWERS ARE EXPECTED TO MOVE FROM WESTERN INTO CENTRAL NORTH DAKOTA THIS EVENING...AND BECOME MORE WIDESPREAD AS THEY MERGE WITH SHOWERS MOVING IN FROM THE SOUTH. EMBEDDED MVFR CONDITIONS POSSIBLE IN RAIN. && .FIRE WEATHER... ISSUED AT 315 PM CDT SAT APR 18 2015 CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...AYD LONG TERM...AJ AVIATION...TWH FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1253 AM CDT FRI APR 17 2015 .UPDATE... UPDATE ISSUED AT 1253 AM CDT FRI APR 17 2015 UPDATED FORECAST WITH THE CURRENT OBS. LOW TEMPERATURES HAVE BEEN DUMPED DOWN TO REFLECT THE CURRENT OBS AND DEWPOINTS. UPDATE ISSUED AT 1001 PM CDT THU APR 16 2015 AS DISCUSSED BELOW...DRY AIR/LIGHT WINDS/A CLEAR SKY RESULTING IN TEMPERATURES QUICKLY FALLING THROUGH THE 40S. ALREADY SOME MID 30S REPORTED AT HETTINGER AND TIOGA. WILL BUMP OVERNIGHT LOWS DOWN A BIT MORE. PRODUCTS OUT IN THE NEXT 15-20 MINUTES. UPDATE ISSUED AT 639 PM CDT THU APR 16 2015 VERY DRY AIR FILTERING IN FROM THE NORTHWEST. LOWERED DEW POINTS A BIT CLOSER TO THE HRRR WHICH SEEMS TO BEST CAPTURE THIS...TEENS TO LOW 20S WEST AND CENTRAL...30S OVER MY FAR SOUTHEAST. WITH A CLEAR SKY AND WINDS TAPERING OFF...A GOOD SETUP FOR RADIATIONAL COOLING TONIGHT SO DID TWEAK TEMPS DOWN A TAD...LOW 30S OVER MY WEST. MAY NEED TO GO LOWER AND WILL MONITOR TRENDS OVER THE NEXT FEW HOURS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 256 PM CDT THU APR 16 2015 H500 DEFORMATION ZONE BETWEEN THE CLOSED LOW ALOFT OVER THE FOUR CORNERS AREA AND THE WESTERLY FLOW OVER SOUTHERN CANADA FORMING A REGION OF SINKING/DRYING AIR OVER NORTHERN NORTH DAKOTA. AT THE SURFACE HIGH PRESSURE OVER WYOMING AND MONTANA WILL MOVE EAST. THESE FEATURES WILL CLEAR SKIES ACROSS THE REGION TONIGHT AND FRIDAY. USED THE RAWBLEND GUIDANCE WHICH HAS PERFORMED WELL PAST FEW NIGHT FOR MINIMUM TEMPERATURES. FOR HIGHS FRIDAY FOLLOWED THE EUROPEAN BIAS CORRECTED GUIDANCE. THIS GAVE HIGHS CLOSE TO 70. SEVERAL FACTORS COMBINING TO KEEP RELATIVE HUMIDITY LOW THROUGH THE SHORT TERM. VEGETATION STILL LARGELY DORMANT AND LACK OF SOIL MOISTURE KEEPS EVAPOTRANSPIRATION LOW. SO MAX RELATIVE HUMIDITY TONIGHT SHOULD BE WELL BELOW SATURATION AND IN THE 70S...WITH MIN RELATIVE HUMIDITY FRIDAY AROUND 20 PERCENT. WHAT WILL KEEP FIRE WEATHER CONCERNS LOW WILL BE THE LACK OF WIND. EXPECTING NORTHERLY WINDS AROUND 10 MPH FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 256 PM CDT THU APR 16 2015 A COOL AND DREARY PATTERN THROUGH THE EXTENDED. WIDESPREAD RAINFALL IS LIKELY SATURDAY INTO SUNDAY. OCCASIONAL SPRINKLES ARE POSSIBLE TROUGH TUESDAY. THE UPPER LEVEL LOW CURRENTLY SPINNING AROUND THE FOUR CORNERS REGION OF THE SOUTHWEST CONUS WILL SLOWLY LIFT NORTHEAST OVER THE NEXT COUPLE OF DAYS. THIS LOW WILL TRANSPORT MOISTURE NORTHWARD. MOISTURE WILL COMBINE WITH AMPLE LIFT SUPPLIED BY ANOTHER LOW...AND COLD FRONT...PROPAGATING ACROSS SOUTHERN CANADA THIS WEEKEND. WIDESPREAD RAINFALL IS LIKELY ACROSS PORTIONS OF THE DAKOTAS AND MINNESOTA. AT THIS TIME THE 12 UTC GFS/ECMWF/SREF INDICATE THE HEAVIEST RAINFALL (HALF INCH OR GREATER) WILL FALL ACROSS SOUTHEAST NORTH DAKOTA AND WESTERN MINNESOTA. AS THE TWO LOWS PROPAGATE EASTWARD AND COMBINE THEY SHOULD CREATE A RATHER DEEP AND SLOW MOVING TROUGH ACROSS THE GREAT LAKES BY EARLY NEXT WEEK. IT APPEARS THIS WILL LEAD TO A RATHER STAGNANT PATTERN OVER THE NEXT WEEK WITH GENERALLY COOL AND CLOUDY CONDITIONS FOR MOST OF NORTH DAKOTA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1253 AM CDT FRI APR 17 2015 VFR CONDITIONS WITH MOSTLY CLEAR SKIES AND LIGHT/VARIABLE WINDS ARE EXPECTED THROUGH THE TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AC SHORT TERM...WAA LONG TERM...AJ AVIATION...AC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1206 AM CDT FRI APR 17 2015 .UPDATE... ISSUED AT 1206 AM CDT FRI APR 17 2015 UPDATED FORECAST WITH THE CURRENT OBS...NO MAJOR ADJUSTMENTS NEEDED. WILL CONTINUE TO MONITOR LOW TEMPERATURES. UPDATE ISSUED AT 1001 PM CDT THU APR 16 2015 AS DISCUSSED BELOW...DRY AIR/LIGHT WINDS/A CLEAR SKY RESULTING IN TEMPERATURES QUICKLY FALLING THROUGH THE 40S. ALREADY SOME MID 30S REPORTED AT HETTINGER AND TIOGA. WILL BUMP OVERNIGHT LOWS DOWN A BIT MORE. PRODUCTS OUT IN THE NEXT 15-20 MINUTES. UPDATE ISSUED AT 639 PM CDT THU APR 16 2015 VERY DRY AIR FILTERING IN FROM THE NORTHWEST. LOWERED DEW POINTS A BIT CLOSER TO THE HRRR WHICH SEEMS TO BEST CAPTURE THIS...TEENS TO LOW 20S WEST AND CENTRAL...30S OVER MY FAR SOUTHEAST. WITH A CLEAR SKY AND WINDS TAPERING OFF...A GOOD SETUP FOR RADIATIONAL COOLING TONIGHT SO DID TWEAK TEMPS DOWN A TAD...LOW 30S OVER MY WEST. MAY NEED TO GO LOWER AND WILL MONITOR TRENDS OVER THE NEXT FEW HOURS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 256 PM CDT THU APR 16 2015 H500 DEFORMATION ZONE BETWEEN THE CLOSED LOW ALOFT OVER THE FOUR CORNERS AREA AND THE WESTERLY FLOW OVER SOUTHERN CANADA FORMING A REGION OF SINKING/DRYING AIR OVER NORTHERN NORTH DAKOTA. AT THE SURFACE HIGH PRESSURE OVER WYOMING AND MONTANA WILL MOVE EAST. THESE FEATURES WILL CLEAR SKIES ACROSS THE REGION TONIGHT AND FRIDAY. USED THE RAWBLEND GUIDANCE WHICH HAS PERFORMED WELL PAST FEW NIGHT FOR MINIMUM TEMPERATURES. FOR HIGHS FRIDAY FOLLOWED THE EUROPEAN BIAS CORRECTED GUIDANCE. THIS GAVE HIGHS CLOSE TO 70. SEVERAL FACTORS COMBINING TO KEEP RELATIVE HUMIDITY LOW THROUGH THE SHORT TERM. VEGETATION STILL LARGELY DORMANT AND LACK OF SOIL MOISTURE KEEPS EVAPOTRANSPIRATION LOW. SO MAX RELATIVE HUMIDITY TONIGHT SHOULD BE WELL BELOW SATURATION AND IN THE 70S...WITH MIN RELATIVE HUMIDITY FRIDAY AROUND 20 PERCENT. WHAT WILL KEEP FIRE WEATHER CONCERNS LOW WILL BE THE LACK OF WIND. EXPECTING NORTHERLY WINDS AROUND 10 MPH FRIDAY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 256 PM CDT THU APR 16 2015 A COOL AND DREARY PATTERN THROUGH THE EXTENDED. WIDESPREAD RAINFALL IS LIKELY SATURDAY INTO SUNDAY. OCCASIONAL SPRINKLES ARE POSSIBLE TROUGH TUESDAY. THE UPPER LEVEL LOW CURRENTLY SPINNING AROUND THE FOUR CORNERS REGION OF THE SOUTHWEST CONUS WILL SLOWLY LIFT NORTHEAST OVER THE NEXT COUPLE OF DAYS. THIS LOW WILL TRANSPORT MOISTURE NORTHWARD. MOISTURE WILL COMBINE WITH AMPLE LIFT SUPPLIED BY ANOTHER LOW...AND COLD FRONT...PROPAGATING ACROSS SOUTHERN CANADA THIS WEEKEND. WIDESPREAD RAINFALL IS LIKELY ACROSS PORTIONS OF THE DAKOTAS AND MINNESOTA. AT THIS TIME THE 12 UTC GFS/ECMWF/SREF INDICATE THE HEAVIEST RAINFALL (HALF INCH OR GREATER) WILL FALL ACROSS SOUTHEAST NORTH DAKOTA AND WESTERN MINNESOTA. AS THE TWO LOWS PROPAGATE EASTWARD AND COMBINE THEY SHOULD CREATE A RATHER DEEP AND SLOW MOVING TROUGH ACROSS THE GREAT LAKES BY EARLY NEXT WEEK. IT APPEARS THIS WILL LEAD TO A RATHER STAGNANT PATTERN OVER THE NEXT WEEK WITH GENERALLY COOL AND CLOUDY CONDITIONS FOR MOST OF NORTH DAKOTA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 639 PM CDT THU APR 16 2015 A FEW HIGH CLOUDS ACROSS THE NORTH MOVING THROUGH TONIGHT...OTHERWISE A CLEAR SKY AND VFR CONDITIONS THROUGH THE 00Z PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AC SHORT TERM...WAA LONG TERM...AJ AVIATION...NH
AREA FORECAST DISCUSSION
NWS TULSA OK
627 PM CDT SAT APR 18 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. MAINLY VFR CONDITIONS ACROSS THE AREA THIS EVENING WITH THUNDERSTORMS DEVELOPING TO THE WEST OF THE AREA. WENT WITH A TEMPO FOR THUNDER AT THE EASTERN OKLAHOMA TAF SITES AT 04Z. THIS IS IN LINE WITH WHAT THE LATEST HRRR IS PROJECTING. FOG WILL BE A CONCERN LATE TONIGHT AT THE NORTHWEST ARKSANS SITES...COULD SEE IFR CONDITIONS BEFORE IMPROVING MID-MORNING SUNDAY. && .PREV DISCUSSION... /ISSUED 405 PM CDT SAT APR 18 2015/ DISCUSSION... AN UPPER LEVEL LOW CONTINUES TO RESIDE THIS AFTERNOON OVER SOUTHERN COLORADO AND NORTHERN NEW MEXICO PER LATEST WATER VAPOR IMAGERY. OUT AHEAD OF THE UPPER LOW A DRYLINE HAS SET UP OVER FAR WESTERN OKLAHOMA INTO WESTERN TEXAS. SCATTERED STRONG/SEVERE CONVECTION HAS BEGUN TO INITIATE DURING THE PAST COUPLE OF HOURS ALONG AND NEAR THIS DRYLINE...MOVING TO THE NORTH. TO THE EAST ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...THE PRECIP FROM THIS MORNING/EARLY AFTERNOON HAS SHIFTED OUT OF THE CWA WITH PARTLY TO MOSTLY CLOUDY SKIES. THIS EVENING AND OVERNIGHT TONIGHT...THE UPPER LOW OUT WEST IS EXPECTED TO FINALLY PUSH OUT INTO WESTERN KANSAS AND BECOME MORE OF AN OPEN WAVE COMPARED TO THE CLOSED OFF LOW THAT IT HAS BEEN. AS THE LOW SHIFTS EASTWARD...THE SCATTERED CONVECTION SHOULD MAKE ITS WAY TOWARD AND INTO PORTIONS OF THE CWA TONIGHT. THE GREATER INSTABILITY WILL BE LOCATED CLOSER TO THE DRYLINE THIS AFTERNOON/EVENING WHICH SHOULD AID IN CONVECTION WEAKENING AS IT PUSHES INTO THE CWA OVERNIGHT. HOWEVER...ENOUGH SHEAR AND COLD TEMPS ALOFT WILL ALLOW FOR A LIMITED SEVERE POTENTIAL WITH LARGE HAIL AND STRONG WINDS BEGIN THE MAIN THREATS ACROSS THE CWA THIS EVENING AND OVERNIGHT. CLOUDY CONDITIONS ALONG WITH DEWPOINTS HOLDING IN THE UPPER 50/LOW 60S SHOULD KEEP LOW TEMPS SUNDAY MORNING CLOSE TO THIS MORNING LOWS. THE UPPER LOW IS FORECAST TO MOVE ACROSS THE REGION DURING THE DAY SUNDAY...PUSHING A COLD FRONT INTO EASTERN OKLAHOMA SUNDAY AFTERNOON AND THROUGH NORTHWEST ARKANSAS SUNDAY EVENING. AHEAD OF THE COLD FRONT...THUNDERSTORM CHANCES WILL CONTINUE OVER THE CWA WITH A LIMITED SEVERE POTENTIAL OVER MUCH OF THE REGION AS THE CAP LOOKS TO BE WEAK. AN ELEVATED SEVERE POTENTIAL LOOKS POSSIBLE OVER SOUTHEAST OKLAHOMA INTO WEST CENTRAL ARKANSAS AND EXTENDING EASTWARD WHERE THE WARMER TEMPS AND BETTER INSTABILITY LOOKS TO BE LOCATED. LARGE HAIL AND DAMAGING WINDS AGAIN LOOK TO BE THE MAIN HAZARDS WITH ANY CONVECTION AHEAD OF THE FRONT. BEHIND THE FRONT...GUSTY NORTHERLY WINDS IN THE 20 TO 30 MPH RANGE WILL BE POSSIBLE. LATEST MODEL SOLUTIONS INDICATE THE COLD FRONT EXITING THE CWA SUNDAY EVENING AS THE UPPER LOW GETS ABSORBED INTO A SECOND LOW PRESSURE SYSTEM DROPPING OUT OF CENTRAL CANADA AND INTO THE GREAT LAKES REGION. THIS WILL AID IN TEMPS FALLING INTO THE 40S FOR MOST LOCATIONS BY MONDAY MORNING AND COOL HIGH TEMPS MONDAY AFTERNOON. DRIER AIR OVER THE CWA WILL HELP TO DELAY THE NEXT PRECIP CHANCES INTO TUESDAY AS A PIECE OF ENERGY DROPS DOWN THROUGH THE PLAINS ON THE BACKSIDE OF THE SLOW MOVING UPPER LOW OVER THE GREAT LAKES. IN THE EXTENDED FORECAST...A FRONTAL BOUNDARY LOOKS TO MOVE INTO THE CWA THURSDAY AHEAD OF ANOTHER SHORTWAVE MOVING INTO THE SOUTHERN PLAINS WITHIN THE ZONAL FLOW ALOFT. THIS BOUNDARY SHOULD BECOME THE FOCUS FOR THUNDERSTORM DEVELOPMENT WEDNESDAY INTO THE WEEKEND BEFORE THE SHORTWAVE AND THE FRONT PUSHES EAST OF THE CWA. INCREASING MOISTURE...AN UPPER LEVEL JET STREAK OF 100-130KT PARALLEL TO THE NEARLY STATIONARY FRONTAL BOUNDARY AND INSTABILITY OVER THE REGION WILL ALLOW FOR THE POTENTIAL FOR SEVERE WEATHER TO BE POSSIBLE OVER THE REGION. TEMPS DURING THIS TIME FRAME LOOK TO BE COOLER ON THE NORTHERN SIDE OF THE FRONT AND WARMER TO THE SOUTH. LATEST INDICATIONS ARE THAT TEMPS COULD BE COOLER THAN WHAT HAS BEEN FORECAST WHICH COULD LIMITED THE OVERALL SEVERE POTENTIAL. THUS...WILL CONTINUE TO MONITOR LATEST DATA AS THIS SYSTEM SETS UP OVER THE NEXT SEVERAL DAYS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...10
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1030 AM MDT FRI APR 17 2015 .UPDATE... ISSUED AT 1022 AM MDT FRI APR 17 2015 UPPER LOW CONTINUES TO CHURN OVER THE FOUR CORNERS REGION WITH BANDS OF LIGHT RAIN MOVING NORTHWEST THROUGH NEBRASKA AND JUST EDGING INTO FAR SOUTHWEST SOUTH DAKOTA. EXPECT THESE BANDS OF LIGHT RAIN TO CONTINUE TO MOVE INTO FAR SOUTHERN PORTIONS OF SOUTH DAKOTA WITH RAIN EVENTUALLY MOVING NORTH TO THE INTERSTATE 90 CORRIDOR BY LATE THIS AFTERNOON. MADE MINOR ADJUSTMENTS TO THE PROGRESSION OF RAIN NORTHWARD - SLOWING IT DOWN...AND REMOVED MENTION OF ISOLATED THUNDER THROUGH LATE AFTERNOON...AS IT LOOKS LIKE LAPSE RATES AND AVAILABLE ENERGY ARE MEAGER AT BEST. BETTER CHANCES FOR THUNDER ACROSS NORTHEAST WYOMING AND SOUTHERN SOUTH DAKOTA SATURDAY AFTERNOON. REMAINDER OF FORECAST IN GOOD SHAPE. UPDATES ARE OUT. && .SHORT TERM...TODAY THROUGH SATURDAY NIGHT ISSUED AT 352 AM MDT FRI APR 17 2015 CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE OKLAHOMA PANHANDLE AREA RIGHT NOW...WITH WEAK HIGH PRESSURE OVER EASTERN MT INTO WESTERN ND. UPPER LEVEL ANALYSIS SHOWS LARGE LOW PRESSURE SYSTEM CENTERED OVER THE FOUR CORNERS AREA...WITH STRONG JET WRAPPING AROUND THE SOUTHERN AND EASTERN SIDES OF THE LOW. CLOUD SHIELD TO THE NORTH AND EAST OF THE SYSTEM IS PUSHING NORTHWARD INTO SOUTHERN PARTS OF THE CWA...BUT DRYING UP AS IT MOVES INTO VERY DRY AIRMASS OVER NORTHERN PORTIONS OF THE NORTHERN PLAINS RIGHT NOW. REGIONAL RADARS SHOWING SHOWERS MOVING WEST-NORTHWEST ACROSS MUCH OF WESTERN NEB INTO SOUTHEAST WY...WITH DRY CONDITIONS PREVAILING ACROSS OUR CWA AT THE MOMENT. TEMPS CURRENTLY RANGE FROM THE LOW TO MID 30S ACROSS PORTIONS OF NORTHEAST WY...THE BLACK HILLS...AND FAR NORTHWEST SD...TO THE UPPER 40S ACROSS SOUTH CENTRAL SD. WINDS ARE VARIABLE AT LESS THAN 10 MPH. THE SYSTEM OVER THE FOUR CORNERS AREA EARLY THIS MORNING WILL MOVE SLOWLY NORTHEASTWARD ACROSS SOUTHERN AND EASTERN CO OVER THE NEXT COUPLE OF DAYS AND THEN ACCELERATE EASTWARD ACROSS THE CENTRAL PLAINS SATURDAY NIGHT INTO SUNDAY. THE EXACT TRACK AND TIMING OF THE SYSTEM IS STILL UNCERTAIN AT THIS POINT AND WILL ULTIMATELY HELP DETERMINE HOW MUCH PCPN WE GET ACROSS THE AREA...ESPECIALLY NORTHERN AND WESTERN PORTIONS OF THE CWA...WHERE AMOUNTS OF VERY LITTLE TO A HALF INCH OR MORE ARE POSSIBLE DEPENDING ON THE TRACK. ALL THE 00Z SHORT RANGE MODELS SHOW MOST OR ALL OF THE CWA RECEIVING AT LEAST A LITTLE BIT OF RAINFALL...WITH THE HIGHEST AMOUNTS GENERALLY OVER FAR SOUTHWEST INTO SOUTH CENTRAL SD. THE 00Z GFS SHOWS THE HEAVIEST PCPN FURTHER EAST TOWARD CENTRAL SD...WHILE THE OTHER MODELS GENERALLY HAVE IT OVER FAR SOUTHWEST/SOUTHERN SD. WILL LEAN THE FORECAST MORE TOWARD THE CONSENSUS AT THIS POINT AND KEEP HEAVIER PCPN AMOUNTS OVER FAR SOUTHERN SD. FORECAST CONFIDENCE IS HIGHEST RIGHT NOW ON SOUTHERN PORTIONS OF THE CWA RECEIVING THE MOST RAINFALL...AS WELL AS THE BEST CHANCES FOR RAINFALL ACROSS THE CWA BEING LATER TONIGHT INTO SATURDAY EVENING. PROJECTED RAINFALL AMOUNTS ACROSS THE CWA WILL MOSTLY BE IN THE 0.25 TO 0.75 INCH RANGE...WITH LESSER AMOUNTS LIKELY OVER FAR NORTHWESTERN PORTIONS OF THE CWA AND POSSIBLY AN INCH OR MORE OVER FAR SOUTHWEST INTO SOUTH CENTRAL SD. HOWEVER...WOULD TEND TO LEAN MORE TOWARD THE LIGHTER AMOUNTS FOR MOST AREAS AS HAS BEEN THE CASE FOR SYSTEMS OF LATE. FOR TODAY...SKIES WILL STAY MOSTLY CLOUDY ACROSS FAR SOUTHERN PORTIONS OF THE CWA...WITH CLOUDS GRADUALLY INCREASING TO THE NORTH. WITH MORE SUNSHINE...TEMPS THIS AFTERNOON WILL BE HIGHEST OVER FAR NORTHERN AND EASTERN PORTIONS OF THE CWA...WITH HIGHS RANGING FROM THE 50S OVER THE BLACK HILLS AND FAR SOUTHWEST SD TO THE MID TO UPPER 60S OVER FAR NORTHWEST INTO CENTRAL SD. WINDS WILL BECOME EAST TO NORTHEAST IN MOST AREAS BY THE AFTERNOON. CHANCES FOR SHOWERS WILL MAINLY BE CONFINED TO SOUTHERN SD TODAY...WITH THE BEST CHANCES IN THE AFTERNOON. CAN NOT RULE OUT A THUNDERSTORM OR TWO ACROSS SOUTHERN AREAS AS WELL THIS AFTERNOON. AS THE UPPER LOW MOVES ACROSS CO TONIGHT AND SATURDAY...LOW LEVEL MOISTURE AND UPPER LEVEL ENERGY WILL EXPAND NORTHWARD INTO THE NORTHERN PLAINS...ESPECIALLY LATER TONIGHT AND SATURDAY. SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED ACROSS THE AREA. THE MOST WIDESPREAD COVERAGE OF SHOWERS SHOULD BE ON SATURDAY...SO WILL GO WITH LIKELY POPS ACROSS MOST OF THE CWA. WITH THE LOW STAYING FAR ENOUGH SOUTH OF THE CWA...TEMPS WILL STAY WARM ENOUGH FOR MOSTLY RAIN ACROSS EVEN THE BLACK HILLS...BUT COULD SEE A MIX OVER THE HIGHEST ELEVATIONS...MAINLY LATE TONIGHT/EARLY SATURDAY AND THEN SATURDAY NIGHT WHEN THE SYSTEM EXITS. A COLD FRONT WILL TRACK ACROSS THE CWA LATE SATURDAY AND SATURDAY NIGHT...HELPING TO PUSH THE SYSTEM OUT OF THE REGION...BUT WILL BRING GUSTY WINDS ACROSS THE AREA INTO SUNDAY. .LONG TERM...SUNDAY THROUGH THURSDAY ISSUED AT 352 AM MDT FRI APR 17 2015 BLOCKED FLOW TO DEVELOP OVER THE WESTERN ATLANTIC AND EASTERN NOAM...WHICH WILL SET THE STAGE FOR WESTERN NOAM RIDING AND POTENTIAL REX TYPE BLOCKING OVER THE WESTERN CONUS. THIS WILL SUPPORT A LOW CONFIDENCE FLOW REGIME AS FORECAST MODELS WILL CONTINUALLY ADJUST TO THE LATEST OBS GIVEN TYPICAL POOR MODEL PERFORMANCE IN THESE PATTERNS. GENERALLY DRY CONDS CAN BE EXPECTED GIVEN THE REGION/S PROXY TO THE EASTERN NOAM UPPER TROUGH. A WEAK SIGNAL FOR PRECIP DOES REMAIN TOWARD THE END OF THE PERIOD WHEN FORECAST MODELS TRY TO ADVECT A WANDERING UPPER TROUGH EAST. HOWEVER...AS ALREADY STATED...LOW CONFIDENCE PER FLOW DETAILS LENDS ONLY A 20 POP AT BEST...WITH DRY THE LIKELY SCENARIO GIVEN THE PATTERN. GIVEN STRONG INFLUENCE EXPECTED OF THE EVENTUAL EASTERN CONUS UPPER LOW...EXPECT TEMPS TO BE NEAR OR SLIGHTLY BELOW SEASONAL NORMS IN THE MAJORITY OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 538 AM MDT FRI APR 17 2015 VFR CONDS WILL PREVAIL MOST PLACES IN THE PERIOD. A SLOW MOVING UPPER LOW WILL SLIDE NE AND BRING MVFR CONDS IN RAIN TO MAINLY EXTREME SW SD TODAY. MVFR CONDS WILL SPREAD NORTH TONIGHT...AFFECTING THE RAP TERMINAL BY LATE IN THE PERIOD...WITH SCT IFR CIGS POSSIBLE IN THE BLACK HILLS. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...15 SHORT TERM...26 LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
542 AM MDT FRI APR 17 2015 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT ISSUED AT 352 AM MDT FRI APR 17 2015 CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER THE OKLAHOMA PANHANDLE AREA RIGHT NOW...WITH WEAK HIGH PRESSURE OVER EASTERN MT INTO WESTERN ND. UPPER LEVEL ANALYSIS SHOWS LARGE LOW PRESSURE SYSTEM CENTERED OVER THE FOUR CORNERS AREA...WITH STRONG JET WRAPPING AROUND THE SOUTHERN AND EASTERN SIDES OF THE LOW. CLOUD SHIELD TO THE NORTH AND EAST OF THE SYSTEM IS PUSHING NORTHWARD INTO SOUTHERN PARTS OF THE CWA...BUT DRYING UP AS IT MOVES INTO VERY DRY AIRMASS OVER NORTHERN PORTIONS OF THE NORTHERN PLAINS RIGHT NOW. REGIONAL RADARS SHOWING SHOWERS MOVING WEST-NORTHWEST ACROSS MUCH OF WESTERN NEB INTO SOUTHEAST WY...WITH DRY CONDITIONS PREVAILING ACROSS OUR CWA AT THE MOMENT. TEMPS CURRENTLY RANGE FROM THE LOW TO MID 30S ACROSS PORTIONS OF NORTHEAST WY...THE BLACK HILLS...AND FAR NORTHWEST SD...TO THE UPPER 40S ACROSS SOUTH CENTRAL SD. WINDS ARE VARIABLE AT LESS THAN 10 MPH. THE SYSTEM OVER THE FOUR CORNERS AREA EARLY THIS MORNING WILL MOVE SLOWLY NORTHEASTWARD ACROSS SOUTHERN AND EASTERN CO OVER THE NEXT COUPLE OF DAYS AND THEN ACCELERATE EASTWARD ACROSS THE CENTRAL PLAINS SATURDAY NIGHT INTO SUNDAY. THE EXACT TRACK AND TIMING OF THE SYSTEM IS STILL UNCERTAIN AT THIS POINT AND WILL ULTIMATELY HELP DETERMINE HOW MUCH PCPN WE GET ACROSS THE AREA...ESPECIALLY NORTHERN AND WESTERN PORTIONS OF THE CWA...WHERE AMOUNTS OF VERY LITTLE TO A HALF INCH OR MORE ARE POSSIBLE DEPENDING ON THE TRACK. ALL THE 00Z SHORT RANGE MODELS SHOW MOST OR ALL OF THE CWA RECEIVING AT LEAST A LITTLE BIT OF RAINFALL...WITH THE HIGHEST AMOUNTS GENERALLY OVER FAR SOUTHWEST INTO SOUTH CENTRAL SD. THE 00Z GFS SHOWS THE HEAVIEST PCPN FURTHER EAST TOWARD CENTRAL SD...WHILE THE OTHER MODELS GENERALLY HAVE IT OVER FAR SOUTHWEST/SOUTHERN SD. WILL LEAN THE FORECAST MORE TOWARD THE CONSENSUS AT THIS POINT AND KEEP HEAVIER PCPN AMOUNTS OVER FAR SOUTHERN SD. FORECAST CONFIDENCE IS HIGHEST RIGHT NOW ON SOUTHERN PORTIONS OF THE CWA RECEIVING THE MOST RAINFALL...AS WELL AS THE BEST CHANCES FOR RAINFALL ACROSS THE CWA BEING LATER TONIGHT INTO SATURDAY EVENING. PROJECTED RAINFALL AMOUNTS ACROSS THE CWA WILL MOSTLY BE IN THE 0.25 TO 0.75 INCH RANGE...WITH LESSER AMOUNTS LIKELY OVER FAR NORTHWESTERN PORTIONS OF THE CWA AND POSSIBLY AN INCH OR MORE OVER FAR SOUTHWEST INTO SOUTH CENTRAL SD. HOWEVER...WOULD TEND TO LEAN MORE TOWARD THE LIGHTER AMOUNTS FOR MOST AREAS AS HAS BEEN THE CASE FOR SYSTEMS OF LATE. FOR TODAY...SKIES WILL STAY MOSTLY CLOUDY ACROSS FAR SOUTHERN PORTIONS OF THE CWA...WITH CLOUDS GRADUALLY INCREASING TO THE NORTH. WITH MORE SUNSHINE...TEMPS THIS AFTERNOON WILL BE HIGHEST OVER FAR NORTHERN AND EASTERN PORTIONS OF THE CWA...WITH HIGHS RANGING FROM THE 50S OVER THE BLACK HILLS AND FAR SOUTHWEST SD TO THE MID TO UPPER 60S OVER FAR NORTHWEST INTO CENTRAL SD. WINDS WILL BECOME EAST TO NORTHEAST IN MOST AREAS BY THE AFTERNOON. CHANCES FOR SHOWERS WILL MAINLY BE CONFINED TO SOUTHERN SD TODAY...WITH THE BEST CHANCES IN THE AFTERNOON. CAN NOT RULE OUT A THUNDERSTORM OR TWO ACROSS SOUTHERN AREAS AS WELL THIS AFTERNOON. AS THE UPPER LOW MOVES ACROSS CO TONIGHT AND SATURDAY...LOW LEVEL MOISTURE AND UPPER LEVEL ENERGY WILL EXPAND NORTHWARD INTO THE NORTHERN PLAINS...ESPECIALLY LATER TONIGHT AND SATURDAY. SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED ACROSS THE AREA. THE MOST WIDESPREAD COVERAGE OF SHOWERS SHOULD BE ON SATURDAY...SO WILL GO WITH LIKELY POPS ACROSS MOST OF THE CWA. WITH THE LOW STAYING FAR ENOUGH SOUTH OF THE CWA...TEMPS WILL STAY WARM ENOUGH FOR MOSTLY RAIN ACROSS EVEN THE BLACK HILLS...BUT COULD SEE A MIX OVER THE HIGHEST ELEVATIONS...MAINLY LATE TONIGHT/EARLY SATURDAY AND THEN SATURDAY NIGHT WHEN THE SYSTEM EXITS. A COLD FRONT WILL TRACK ACROSS THE CWA LATE SATURDAY AND SATURDAY NIGHT...HELPING TO PUSH THE SYSTEM OUT OF THE REGION...BUT WILL BRING GUSTY WINDS ACROSS THE AREA INTO SUNDAY. .LONG TERM...SUNDAY THROUGH THURSDAY ISSUED AT 352 AM MDT FRI APR 17 2015 BLOCKED FLOW TO DEVELOP OVER THE WESTERN ATLANTIC AND EASTERN NOAM...WHICH WILL SET THE STAGE FOR WESTERN NOAM RIDING AND POTENTIAL REX TYPE BLOCKING OVER THE WESTERN CONUS. THIS WILL SUPPORT A LOW CONFIDENCE FLOW REGIME AS FORECAST MODELS WILL CONTINUALLY ADJUST TO THE LATEST OBS GIVEN TYPICAL POOR MODEL PERFORMANCE IN THESE PATTERNS. GENERALLY DRY CONDS CAN BE EXPECTED GIVEN THE REGION/S PROXY TO THE EASTERN NOAM UPPER TROUGH. A WEAK SIGNAL FOR PRECIP DOES REMAIN TOWARD THE END OF THE PERIOD WHEN FORECAST MODELS TRY TO ADVECT A WANDERING UPPER TROUGH EAST. HOWEVER...AS ALREADY STATED...LOW CONFIDENCE PER FLOW DETAILS LENDS ONLY A 20 POP AT BEST...WITH DRY THE LIKELY SCENARIO GIVEN THE PATTERN. GIVEN STRONG INFLUENCE EXPECTED OF THE EVENTUAL EASTERN CONUS UPPER LOW...EXPECT TEMPS TO BE NEAR OR SLIGHTLY BELOW SEASONAL NORMS IN THE MAJORITY OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 538 AM MDT FRI APR 17 2015 VFR CONDS WILL PREVAIL MOST PLACES IN THE PERIOD. A SLOW MOVING UPPER LOW WILL SLIDE NE AND BRING MVFR CONDS IN RAIN TO MAINLY EXTREME SW SD TODAY. MVFR CONDS WILL SPREAD NORTH TONIGHT...AFFECTING THE RAP TERMINAL BY LATE IN THE PERIOD...WITH SCT IFR CIGS POSSIBLE IN THE BLACK HILLS. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...26 LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1006 PM CDT SAT APR 18 2015 .UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO INCREASE SHWR/TSTM CHANCES FROM SW TO NE REST OF EVENING AND OVERNIGHT. TWEAKED HRLY TEMP...DEWPOINT... SKY...AND WIND SPEED/DIRECTION GRIDS ALSO. REMAINDER OF FORECAST REMAINS ON TRACK. && .PREV DISCUSSION.../ISSUED 633 PM CDT SAT APR 18 2015/ UPDATE...FOR AVIATION. AVIATION... 00Z TAFS...BNA/CKV/CSV...A LOW PRESSURE SYSTEM AND WARM FRONT WILL LIFT INTO MID TN OVERNIGHT BRINGING WIDESPREAD SHOWERS WITH EMBEDDED TSRA. LOOK FOR MVFR CIGS/VSBYS TO DEVELOP AROUND 06Z...DROPPING TO IFR AND SOME LIFR WITH POCKETS OF +SHRA BY 11Z. THE MAIN BAND OF MOISTURE WILL LIFT NORTH OF THE ARA BY 18Z...WITH IMPROVEMENT ON SUNDAY AFTERNOON. ANOTHER SYSTEM WILL APPROACH SUNDAY EVENING WITH SCATTERED TSRA...SOME POSSIBLY SEVERE. 13 PREV DISCUSSION... /ISSUED 530 PM CDT SAT APR 18 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT. PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/ DISCUSSION... AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING ANYTHING STRONG OR SEVERE TONIGHT. BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW 70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY. THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE 40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH TEMPERATURES IN THE MID 60S. THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM CHANCES FRIDAY NIGHT. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
633 PM CDT SAT APR 18 2015 .UPDATE...FOR AVIATION. && .AVIATION... 00Z TAFS...BNA/CKV/CSV...A LOW PRESSURE SYSTEM AND WARM FRONT WILL LIFT INTO MID TN OVERNIGHT BRINGING WIDESPREAD SHOWERS WITH EMBEDDED TSRA. LOOK FOR MVFR CIGS/VSBYS TO DEVELOP AROUND 06Z...DROPPING TO IFR AND SOME LIFR WITH POCKETS OF +SHRA BY 11Z. THE MAIN BAND OF MOISTURE WILL LIFT NORTH OF THE ARA BY 18Z...WITH IMPROVEMENT ON SUNDAY AFTERNOON. ANOTHER SYSTEM WILL APPROACH SUNDAY EVENING WITH SCATTERED TSRA...SOME POSSIBLY SEVERE. 13 && .PREV DISCUSSION... /ISSUED 530 PM CDT SAT APR 18 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT. PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/ DISCUSSION... AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING ANYTHING STRONG OR SEVERE TONIGHT. BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW 70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY. THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE 40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH TEMPERATURES IN THE MID 60S. THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM CHANCES FRIDAY NIGHT. && .OHX WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
336 AM CDT FRI APR 17 2015 .DISCUSSION... BROAD SOUTHWEST FLOW ALOFT REMAINS IN PLACE ACROSS THE MID SOUTH TODAY OUT AHEAD OF A LARGE UPPER LEVEL LOW PRESSURE SYSTEM SPINNING OVER THE FOUR CORNERS REGION OF THE INTERMOUNTAIN WEST. DEEPER MOISTURE REMAINS IN PLACE ACROSS THE SOUTHERN HALF OF THE FORECAST AREA TO THE SOUTH OF AN INVERTED SURFACE TROUGH THAT REMAINS STRETCHED ACROSS NORTHERN PORTIONS OF THE REGION. A MID LEVEL SHORTWAVE NOTED FROM WATER VAPOR IMAGERY OVER THE ARKLATEX EARLY THIS MORNING WILL CONTINUE TO LIFT NORTHEAST TODAY. THIS SHOULD COMBINE WITH INCREASING INSTABILITY TO SUPPORT HIGH END CHANCES FOR SHOWERS AND THUNDERSTORMS BASICALLY ALONG AND SOUTH OF INTERSTATE 40. CHANCES DECREASE WITH NORTHERN EXTENT AS OVERALL MOISTURE DECREASES. AS THE SHORTWAVE MOVES EAST OF THE REGION TONIGHT AND INSTABILITY WANES...CONVECTION SHOULD DIMINISH. A STRONGER MID LEVEL SHORTWAVE SHOULD EJECT OUT OF THE SOUTHERN PLAINS AND ACROSS THE MID SOUTH ON SATURDAY AND SATURDAY NIGHT. ENHANCED MOISTURE AND LIFT FROM THIS FEATURE SHOULD SUPPORT LIKELY TO CATEGORICAL CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE REGION BY SATURDAY AFTERNOON AND AREAWIDE SATURDAY NIGHT. PERIODS OF HEAVY RAINFALL WILL BE POSSIBLE DURING THIS TIME PERIOD AS RICH MOISTURE SPREADS NORTH FROM THE GULF OF MEXICO. CONSIDERING THE RECENT WET PATTERN OF LATE...SOME FLOODING CONCERNS WILL DEVELOP LATER SATURDAY AND SATURDAY NIGHT. A FLOOD WATCH MAY BE NEEDED IN LATER FORECASTS IF THIS TREND CONTINUES. THE UPPER LEVEL LOW PRESSURE WILL FINALLY LIFT NORTHEAST ACROSS THE MISSISSIPPI RIVER VALLEY AS AN OPEN WAVE BY SUNDAY AND SUNDAY NIGHT. THIS SHOULD FORCE A COLD FRONT EAST ACROSS THE REGION SUNDAY NIGHT. THE ATMOSPHERE SHOULD DESTABILIZE ACROSS THE REGION BY SUNDAY AFTERNOON AND EVENING AS THE UPPER TROUGH OVERSPREADS THE REGION. THIS SHOULD SUPPORT THE DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF THE FRONT. THE ENVIRONMENT APPEARS TO BECOME MORE SUPPORTIVE OF SEVERE STORM DEVELOPMENT DURING THIS TIME PERIOD AS DEEP LAYER SHEAR INCREASES AND LAPSE RATES STEEPEN. STORM MODE APPEARS TO INITIALLY SUPPORT A MIX OF SHORT LINE SEGMENTS AND POTENTIALLY SUPERCELLS WHICH QUICKLY CONGEAL INTO A SQUALL LINE AS MID LEVEL FORCING STRENGTHENS. IT STILL REMAINS A BIT EARLY TO FORECAST OVERALL THREATS WITH CERTAINTY THIS FAR OUT...BUT WILL BEGIN TO MENTION THIS SEVERE WEATHER THREAT IN THE LATEST HAZARDOUS WEATHER OUTLOOK. THE FRONT SHOULD SWEEP EAST OF THE REGION BY EARLY MONDAY MORNING WITH ANY LINGERING SHOWERS AND THUNDERSTORMS ACROSS THE EAST ENDING. MUCH DRIER AND SLIGHTLY COOLER CONDITIONS WILL MOVE INTO THE REGION FOR EARLY NEXT WEEK AS HIGH PRESSURE BUILDS OVERHEAD. PLEASANT SPRING WEATHER WITH SLIGHTLY BELOW AVERAGE TEMPERATURES WILL PERSIST FROM MONDAY THROUGH WEDNESDAY OF NEXT WEEK. A MORE UNSETTLED AND MOISTER WEATHER PATTERN SHOULD BECOME ESTABLISHED ACROSS THE MID SOUTH ONCE AGAIN BY THE END OF NEXT WEEK. JLH && .AVIATION... 06Z TAF CYCLE STRATUS IS CURRENTLY SPREADING NW ACROSS THE CWA. KTUP IS ALREADY EXPERIENCING IFR CIGS AND EXPECT KMKL AND KMEM TO SEE THEM BY 7Z. MEANWHILE...EXPECT SOME FOG TO BEGIN DEVELOPING AT KJBR AND CONDITIONS SHOULD DETERIORATE RAPIDLY TO VLIFR. STRATUS AND FOG MAY BE SLOW TO LIFT IN THE MORNING. LATEST HRRR SHOWS SHRAS POSSIBLY A FEW TSRAS DEVELOPING ACROSS N MS AROUND 15Z THAT WILL SPREAD NORTH AND EAST INTO THE KMEM AND KTUP AREA THROUGH AT LEAST 20-21Z. LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD. KRM && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1221 AM CDT FRI APR 17 2015 .UPDATE... UPDATED TO ADD 06Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 909 PM CDT THU APR 16 2015/ UPDATE...EVENING UPDATE. DISCUSSION... DECREASED POPS BASED ON RADAR COVERAGE. SHORT TERM GUIDANCE HAS BEEN PRETTY ACCURATE LATELY...AND IT HAS MORE DEVELOPMENT ACROSS EAST ARKANSAS AND NORTH MISSISSIPPI TOWARD MORNING. TEMPERATURES ARE ON TRACK. PREV DISCUSSION... /ISSUED 650 PM CDT THU APR 16 2015/ DISCUSSION... /ISSUED 307 PM CDT THU APR 16 2015/ SKIES ARE MOSTLY SUNNY OVER A LARGE PORTION OF THE FORECAST AREA THIS AFTERNOON WITH TEMPERATURES RANGING FROM THE UPPER 60S TO LOWER 80S. A FEW SHOWERS AND ISOLATED THUNDERSTORMS WERE MOVING ACROSS PORTIONS OF NORTHEAST MISSISSIPPI AT THIS TIME. THIS ACTIVITY HAS FORMED NEAR A WEAK FRONTAL BOUNDARY WHICH EXTENDS FROM CENTRAL MISSISSIPPI THROUGH SOUTHEAST ALABAMA AND INTO NORTH FLORIDA. THIS BOUNDARY IS EXPECTED TO LIFT NORTH TONIGHT AND AS IT DOES ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP WITH THE BEST CHANCE OF THUNDERSTORMS EXPECTED OVER NORTHEAST MISSISSIPPI. TEMPERATURES WILL REMAIN ON THE WARM SIDE WITH LOWS FRIDAY MORNING IN THE UPPER 50S TO MID 60S. BY FRIDAY MORNING THE BOUNDARY WILL RETREAT BACK SOUTH WITH ADDITIONAL SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP MAINLY OVER PORTIONS OF NORTH MISSISSIPPI. TEMPERATURES WILL REMAIN ON THE WARM SIDE WITH HIGHS IN THE UPPER 70S TO AROUND 80 DEGREES. BY FRIDAY NIGHT...AN UPPER LEVEL LOW WILL BE MOVING SLOWLY OUT OF THE CENTRAL ROCKIES AND INTO THE PLAINS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AHEAD OF THIS SYSTEM WITH SOME OF THIS ACTIVITY POSSIBLY MOVING INTO MAINLY WESTERN SECTIONS OF THE FORECAST AREA. ON SATURDAY AS THE UPPER LOW PUSHES FURTHER EAST THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL INCREASE FOR SATURDAY AND SATURDAY NIGHT. BY SUNDAY...A COLD FRONT WILL BE MOVING INTO EASTERN OKLAHOMA AND WESTERN ARKANSAS SO MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED. THE COLD FRONT WILL MOVE THROUGH THE FORECAST AREA SUNDAY NIGHT WITH ADDITIONAL SHOWERS AND THUNDERSTORMS. THERE MAY ALSO BE A SMALL CHANCE OF SEVERE THUNDERSTORMS AHEAD OF THE FRONT. COOLER AND DRIER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT ON MONDAY BRINING AN END TO THE THREAT OF THUNDERSTORMS WITH TEMPERATURES DROPPING BACK CLOSER TO NORMAL LEVELS. DRY WEATHER WILL CONTINUE INTO TUESDAY AND WEDNESDAY AS WELL WITH HIGH PRESSURE REMAINING IN CONTROL. TEMPERATURES WILL REMAIN NEAR NORMAL LEVELS. ANOTHER COLD FRONT IS EXPECTED TO DROP SOUTH INTO THE CENTRAL PLAINS AND OHIO VALLEY WEDNESDAY NIGHT AND NEXT THURSDAY. THIS WILL BRING ANOTHER CHANCE OF SHOWERS FOR WEDNESDAY NIGHT AND A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS FOR NEXT THURSDAY. ARS && .AVIATION... 06Z TAF CYCLE STRATUS IS CURRENTLY SPREADING NW ACROSS THE CWA. KTUP IS ALREADY EXPERIENCING IFR CIGS AND EXPECT KMKL AND KMEM TO SEE THEM BY 7Z. MEANWHILE...EXPECT SOME FOG TO BEGIN DEVELOPING AT KJBR AND CONDITIONS SHOULD DETERIORATE RAPIDLY TO VLIFR. STRATUS AND FOG MAY BE SLOW TO LIFT IN THE MORNING. LATEST HRRR SHOWS SHRAS POSSIBLY A FEW TSRAS DEVELOPING ACROSS N MS AROUND 15Z THAT WILL SPREAD NORTH AND EAST INTO THE KMEM AND KTUP AREA THROUGH AT LEAST 20-21Z. LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD. KRM && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1201 AM CDT FRI APR 17 2015 .UPDATE...FOR 06Z AVIATION DISCUSSION. && .AVIATION...06Z AVIATION DISCUSSION. SEVERAL ADMS POSSIBLE THRU AT LEAST 17/15Z DUE TO CEILING FORMATION/ FLUCTUATIONS AND FOG FORMATION POTENTIALLY LIMITING VSBYS. UPPER LEVEL RIDGING INFLUENCES SHOULD AMPLIFY THRU 18/06Z ALSO AND SHOULD LIMIT CONVECTION POTENTIAL AT TAF SITES...AS SHORT RANGE MODELS SHOWING LITTLE IN THE WAY OF CONVECTION AFFECTING TAF SITES THRU 17/12Z. EXPECT MVFR CEILINGS BNA/CSV TO PERSIST THRU AT LEAST 17/15Z. THERE SILL MAYBE ENOUGH BELIEVE THAT THERE MAYBE ENOUGH CLRING...ESPECIALLY ACROSS NW PORTIONS OF THE MID STATE...WITH LIGHT WINDS FOR PATCHY FOG DEVELOPMENT...FOR MVFR TO IFR FOG POSSIBLE...WITH TEMPO LIFR VSBYS POSSIBLE BNA/CSV. EXPECT FOG DISSIPATION AFTER 17/15Z WITH DISSIPATION IN MVFR/IFR CEILINGS GENERALLY AFTER 17/18Z. EXPECT VFR AC/CI CEILINGS AFTER 18/02Z AS UPPER LEVEL RIDGING INFLUENCES BECOME EVEN MORE ENHANCED. && .PREV DISCUSSION.../ISSUED 822 PM CDT THU APR 16 2015/ DISCUSSION... RADAR IS PRECIP FREE AT THIS TIME BUT CLOUDINESS STILL BLANKETS MUCH OF THE AREA. MOISTURE IN THE FORM OF SHOWERS AND THUNDERSTORMS DOES EXIST TO OUR SOUTH AND SOUTHWEST ACROSS MS AND AL. LATEST HRRR DOES INDICATE THAT SOME OF THIS MOISTURE MAY APPROACH OUR SOUTHWESTERN AREAS TOWARD 12Z. UPPER LEVEL PATTERN CONTINUES TO FLOW FROM THE SOUTHWEST. WE ARE EXPECTING SOME AMPLIFICATION OF A SE-NW UPPER RIDGE BY TOMORROW, BEFORE THAT HAPPENS HOWEVER...ONE MORE WEAK DISTURBANCE WILL RIDE NORTHEASTWARD AND JUST ENOUGH UPPER DIVERGENCE MAY HELP PRODUCE THAT AFOREMENTIONED ACTIVITY TOWARD 12Z. OTW...DEWPOINT DEPRESSIONS ARE VERY LOW CURRENTLY. NUMERICAL DATA DOES SUGGEST SOME LOW VSBY CATS. THUS...WILL GO AHEAD AND ADD PATCHY FOG AREA WIDE FOR AFT 06Z. ADDITIONALLY...WILL OPT TO LOWER POPS TO 20 PERCENT FOR THE ENTIRE MID STATE EXCEPT FOR OUR SOUTHWEST...WHERE POPS WILL REMAIN AT 30 PERCENT. JUST SHOWERS TONIGHT...NO T EXPECTED. PREV DISCUSSION... /ISSUED 652 PM CDT THU APR 16 2015/ UPDATE...FOR 00Z AVIATION DISCUSSION. AVIATION...00Z AVIATION DISCUSSION. SEVERAL ADMS POSSIBLE THRU 17/24Z DUE TO CEILING FORMATION/FLUCTUATIONS AND FOG FORMATION POTENTIALLY LIMITING VSBYS. UPPER LEVEL RIDGING INFLUENCES SHOULD AMPLIFY THRU 17/24Z ALSO AND SHOULD LIMIT CONVECTION POTENTIAL AT TAF SITES...AS SHORT RANGE MODELS SHOWING LITTLE IN THE WAY OF CONVECTION THRU 17/12Z. EXPECT MVFR CEILINGS BNA AND CSV TO PERSIST THRU AT LEAST 17/15Z. WITH MOISTURE RICH AIRMASS GENERALLY IN PLACE...BELIEVE THAT THERE MAYBE ENOUGH CLRING...ESPECIALLY ACROSS CNTRL/NW PORTIONS OF THE MID STATE...WITH LIGHT WINDS FOR PATCHY FOG DEVELOPMENT...FOR MVFR TO IFR FOG POSSIBLE...WITH TEMPO LIFR VSBYS POSSIBLE BNA/CSV. EXPECT FOG DISSIPATION AFTER 17/15Z WITH DISSIPATION IN MVFR/IFR CEILINGS AFTER 17/18Z...BUT FOR TAF BREVITY CONCERNS... DID NOT MENTION IN TAF FORECAST AS THIS TIME. PREV DISCUSSION.../ISSUED 318 PM CDT THU APR 16 2015/ SHORT TERM...SKIES REMAINED MOSTLY CLOUDY INTO THE EARLY AFTERNOON OVER EASTERN AND SOUTHERN PARTS OF THE MID-STATE. MEANWHILE, SKIES BECAME PARTLY CLOUDY OVER THE WEST. AS USUAL FOR THIS TIME OF YEAR, TEMPS WERE QUICK TO WARM UP ONCE THE SUN POPPED OUT AND AT 2 PM, CLARKSVILLE WAS EXPERIENCING A TOASTY 74 DEGREES. TEMPERATURES WERE STRUGGLING A BIT MORE IN THE MOSTLY CLOUDY AREAS, WITH 2 PM READINGS MAINLY IN THE MIDDLE AND UPPER 60S OVER EASTERN AND CENTRAL AREAS. THE SHORTWAVE THAT BROUGHT US THE ROUND OF SHOWERS AND THUNDERSTORMS LAST NIGHT AND THIS MORNING, WAS CROSSING THE OHIO VALLEY THIS AFTERNOON AND PUSHING MOST THE SHOWERS AND THUNDERSTORMS TO THE EAST OF OUR FORECAST AREA. HOWEVER, SINCE THE UPPER LEVEL DISTURBANCE WAS PASSING SO FAR TO OUR NORTH, A BAND OF RELATIVELY DEEP MOISTURE WAS SLOW TO PUSH OUT OF OUR EASTERN AND SOUTHERN COUNTIES. AS A RESULT, BY EARLY AFTERNOON SOME SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS REMAINED ALONG THE CUMBERLAND PLATEAU AND IN AREAS CLOSE TO THE ALABAMA BORDER. IT STILL LOOKS LIKE WE`LL GET A TEMPORARY BREAK TONIGHT THROUGH SATURDAY MORNING FROM THE MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY THAT WE`VE SEEN OVER RECENT DAYS. IN ADDITION, AS CLOUDS DIMINISH FRIDAY NIGHT, BELIEVE OUR SOGGY WET GROUND WILL AID THE DEVELOPMENT OF AREAS OF FOG--SOME OF WHICH COULD BECOME LOCALLY DENSE. ANOTHER SWATH OF DEEP MOISTURE SWINGS NORTHEASTWARD ACROSS THE AREA SATURDAY AFTERNOON AND SATURDAY NIGHT, BRINGING ANOTHER ROUND OF SHOWERS AND STORMS AND THE POTENTIAL FOR LOCALLY HEAVY RAINFALL. SINCE THE RESPONSIBLE SHORTWAVE SHEARS OFF ONCE AGAIN TO THE NORTH, THE RAIN IS SLOWER TO CLEAR OUT OF OUR EASTERN AREAS, AND THE CUMBERLAND PLATEAU COULD SEE SHOWERS AND THUNDERSTORMS FOR A GOOD PART OF SUNDAY AS WELL. ANOTHER INCH OR SO OF RAIN WILL LIKELY OCCUR, SOME OF WHICH WILL COME IN DOWNPOURS. SINCE GROUNDS WILL SILL BE PRETTY SOGGY BY THEN, EXPECT RUN OFF TO PRODUCE PONDING OF WATER IN URBAN LOCATIONS (LIKE NASHVILLE) AND IN LOW LYING AREAS. AFTER THE RAIN PASSES EAST OF OUR AREA SUNDAY EVENING, LOOK FOR A COLD FRONT TO SWEEP ACROSS THE AREA SUNDAY NIGHT AND MONDAY MORNING, BRINGING ANOTHER ROUND OF RAIN. THIS WILL PROBABLY COME ACROSS THE AREA AS A RELATIVELY FAST-MOVING BAND OF SHOWERS AND THUNDERSTORMS, AND BRIEF HEAVY DOWNPOURS MAY ONCE AGAIN OCCUR, AND CAUSE SOME PONDING IN LOW LYING SPOTS AND URBAN AREAS. HOWEVER, THE STORMS AND SHOWERS SHOULDN`T LAST LONG, AND BY MONDAY AFTERNOON WE SHOULD BE DRYING OUT PRETTY WELL, AS HIGH PRESSURE BUILDS IN FROM THE WEST. LONG TERM...A DRY SHORTWAVE SWINGS IN MONDAY NIGHT, DEEPENING AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND TENNESSEE VALLEY. SOME PATCHY CLOUDS WILL SPREAD ACROSS THE AREA, BUT DON`T EXPECT ANYTHING MORE THAN SOME LIGHT SPRINKLES. BY SUNRISE TUESDAY, COOLER AIR WILL HAVE WORKED IN FROM THE NORTHWEST AND WE`LL BE LOOKING AT TEMPERATURES IN THE MIDDLE AND UPPER 40S. DRY AND COOL WEATHER LINGERS INTO WEDNESDAY, WITH LOWS IN THE 40S AND HIGHS FROM THE MID 60S TO MID 70S. ATMOSPHERIC MOISTURE INCREASES AGAIN BY LATE NEXT WEEK, CREATING THE CHANCE FOR MORE SHOWERS AND THUNDERSTORMS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1039 PM CDT SAT APR 18 2015 .AVIATION... LIGHT NORTH TO NORTHWEST WINDS WILL INCREASE BY MID MORNING SUNDAY INTO THE 26 TO 32 KNOT RANGE WITH HIGHER GUSTS. WINDS WILL THEN DECREASE TO LESS THAN 10 KNOTS WITH SUNSET ON SUNDAY. SKIES ARE EXPECTED TO REMAIN VFR. && .PREV DISCUSSION... /ISSUED 615 PM CDT SAT APR 18 2015/ AVIATION... A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED UNDER THE COLD CORE OF THE LOW...SO HAVE ENTERED SOME GUSTY SHOWERS INTO THE TAFS FOR THIS EVENING. NORTHWEST WINDS WILL GENERALLY REMAIN AT 10 KNOTS OR LESS OUTSIDE OF THE SHOWERS. NORTHWEST TO NORTH WINDS WILL THEN PICK UP TO 25 TO 30 KNOTS WITH HIGHER GUSTS BY MID MORNING ON SUNDAY. SKIES SHOULD REMAIN VFR. PREV DISCUSSION... /ISSUED 521 PM CDT SAT APR 18 2015/ UPDATE... WEST TEXAS MESONET AND SCHOOL NET OBSERVATIONS SHOW A CONTINUED DECREASE IN SURFACE DEW POINTS AND VEERING OF SURFACE WINDS ACROSS THE FAR EASTERN PORTION OF THE TEXAS PANHANDLE. SPC RAP MESOANALYSIS HAS RESPONDED BY DEPICTING MUCH HIGHER LCL HEIGHTS THAT ARE LESS FAVORABLE FOR TORNADOES. A MORE FAVORABLE ENVIRONMENT EXISTS FURTHER EAST INTO OKLAHOMA WHERE SURFACE WINDS REMAINED BACKED AND AT LEAST SHALLOW LOW LEVEL MOISTURE /DEW POINTS IN THE MID TO UPPER 50S/ IS PRESENT. A FAIRLY POTENT VORT MAX IS MOVING ACROSS THE TEXAS PANHANDLE NOW AS SEEN ON WATER VAPOR LOOP AND THIS MAY RESULT IN AN UPTICK IN CONVECTION OVER THE NEXT COUPLE OF HOURS. HAIL AND WIND ARE STILL POSSIBLE WITH THE STRONGEST STORMS AS ENOUGH INSTABILITY REMAINS INTO EARLY EVENING. WILL CONTINUE TO MONITOR TRENDS IN THE OBSERVATIONS...ESPECIALLY LATER THIS EVENING WHEN MIXING SUBSIDES AND THE DRYLINE POSSIBLY SHIFTS WESTWARD SOME. THE BEST CHANCE OF BETTER LOW LEVEL MOISTURE RETURNING TO THE FORECAST AREA WILL BE ACROSS WHEELER AND COLLINGSWORTH COUNTIES. BRB PREV DISCUSSION... /ISSUED 221 PM CDT SAT APR 18 2015/ DISCUSSION... EARLY THIS AFTERNOON A DEEP CLOSED LOW WAS SITUATED OVER EASTERN COLORADO AND SLOWLY MOVING EAST. A BAND OF CLOUDS ASSOCIATED WITH A RELATIVELY POTENT VORT LOBE ROTATING AROUND THE MID-UPPER LOW WAS EVIDENT IN IR/VIS SATELLITE. SURFACE OBSERVATIONS SHOW LIGHT RAIN BENEATH THIS BAND OF CLOUDS AT CLAYTON NEW MEXICO AND PRESUMABLY FURTHER SOUTH-SOUTHWEST EAST OF TUCUMCARI INTO THE FAR WESTERN TEXAS PANHANDLE WHERE LIGHT ECHOS WERE PRESENT ON REGIONAL RADAR MOSAIC. FURTHER EAST ACROSS THE TEXAS AND OKLAHOMA PANHANDLE LOW CLOUDS HAVE DIMINISHED AND/OR SHIFTED INTO OKLAHOMA AS SURFACE WINDS CONTINUE TO VEER SLIGHTLY. SHALLOW LOW LEVEL MOISTURE SEEN ON 12Z KAMA SOUNDING REMAINS ACROSS THE EASTERN PANHANDLES EAST OF A DIFFUSE DRYLINE. THERE REMAINS SOME UNCERTAINTY ON THE POSITION OF THE DRYLINE THAT IS EXPECTED TO SHARPEN THIS AFTERNOON AS DIABATIC HEATING/MIXING COMMENCES. USING SHORT RANGE MODEL FORECAST SOUNDINGS AS GUIDANCE ON THE DEPTH OF MOISTURE OFF THE CAPROCK AND ESPECIALLY FURTHER EAST NEAR THE OKLAHOMA BORDER LEADS TO FAIRLY HIGH CONFIDENCE ON THE PREVIOUS FORECAST WHICH RELEGATES ANY SUBSTANTIAL DEEP CONVECTION TO NEAR OR JUST EAST OF THE OKLAHOMA STATE LINE LATER THIS AFTERNOON. LOW LEVEL MOISTURE IS DEEPER FROM THERE EASTWARD INTO OKLAHOMA AND THUS DRYLINE CIRCULATION THAT DEVELOPS STANDS A BETTER CHANCE AT INITIATING CONVECTION THERE THAN WAS THE CASE FURTHER WEST YESTERDAY. SO THROUGH THE LATE AFTERNOON AND EVENING THERE IS ONLY A LOW PROBABILITY OF ISOLATED-SCATTERED CONVECTION ACROSS THE EXTREME EASTERN PORTION OF THE PANHANDLES WITH BETTER CHANCES OUT OF THE FORECAST AREA ACROSS WESTERN OKLAHOMA. IF THE ABOVE ASSESSMENT IS MISPLACED SLIGHTLY EAST THAN ANY STORM THAT DOES DEVELOP ON OUR SIDE OF THE STATE LINE WOULD HAVE THE POTENTIAL TO BECOME SEVERE DUE TO MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR OF AROUND 30 KNOTS FOR STORM ORGANIZATION/PERSISTENCE. LARGE HAIL WOULD BE THE PRIMARY THREAT INTO THE EVENING GIVEN STEEP MID LEVEL LAPSE RATES OWING TO THE APPROACHING MID-UPPER LOW. WILL CONTINUE TO MONITOR TRENDS IN SURFACE OBSERVATIONS AND DRYLINE EVOLUTION THROUGHOUT THE AFTERNOON. FURTHER WEST OF THE DRYLINE...DEEP MIXING WILL OCCUR GENERALLY EAST OF THE AFOREMENTIONED BAND OF LOW-MID CLOUDS NOW ENTERING THE TEXAS PANHANDLE. CU FIELD IS INCREASING IMMEDIATELY AHEAD OF THIS. BASES SHOULD BECOME RELATIVELY HIGH AS MIXED LAYER DEEPENS THROUGH THE AFTERNOON. WITH FORCING FROM PREVIOUSLY MENTIONED VORT LOBE CONVECTION MAY BECOME DEEP ENOUGH FOR SHOWERS AND THUNDERSTORMS FOR MUCH OF THE AREA LATER THIS AFTERNOON. IF CONVECTION BECOMES DEEP ENOUGH FOR CHARGE SEPARATION AND LIGHTNING...LIMITED INSTABILITY SHOULD PRECLUDE THE THREAT OF SEVERE THUNDERSTORMS. PROGNOSTICATIONS FROM THE HI-RES CONVECTION ALLOWING GUIDANCE INCLUDING THE HRRR AND TTU WRF SEEM TO LINE UP WELL WITH THE ABOVE THINKING. AS THE MID-UPPER LOW CONTINUES TO SHIFT EAST A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. MODEL GUIDANCE IS IN AGREEMENT IN AN EVOLUTION OF THE LOW INTO A MORE OPEN AND PROGRESSIVE WAVE THAT WILL BE EAST OF THE AREA BY TOMORROW AFTERNOON. AN AREA OF MOISTURE ON THE BACK SIDE OF THIS EVOLVING SHORTWAVE TROUGH FAVORABLY TIMED WITH PEAK HEATING SHOULD BE ENOUGH FOR EXTENSIVE CUMULUS DEVELOPMENT DURING THE AFTERNOON POSSIBLY ENOUGH FOR BROKEN SKY CONDITIONS ESPECIALLY ACROSS THE EASTERN PORTION OF THE AREA. DEPTH OF CONVECTION IN ROUGHLY THE NORTHEAST THIRD WILL NEED TO BE MONITORED AS IT MAY BECOME SUFFICIENT FOR A FEW SHOWERS GIVEN RESIDUAL COOL MID LEVEL TEMPERATURES AND RELATIVELY HIGH TQ INDEX VALUES. ADJUSTED LOW POPS ON SUNDAY AFTERNOON TO EXTEND A BIT FURTHER SOUTH AND WEST TO ACCOUNT FOR THIS. EARLY NEXT WEEK A SPLIT UPPER FLOW PATTERN WILL EXIST WITH STRONG PERIODICALLY PERTURBED WESTERLY SOUTHERN BRANCH JUST SOUTH OF US AND NORTHWESTERLY NORTHERN BRANCH ACROSS THE CENTRAL PLAINS. MEAN RIDGING WILL BE PRESENT OVER THE WESTERN STATES. GRADUALLY INCREASING 500 MB HEIGHTS AND A SLIGHTLY MORE AMPLIFIED PATTERN WILL EVOLVE THROUGH THE WEEK ESPECIALLY AS ANOTHER CLOSED LOW DEVELOPS AND DEEPENS OVER THE SOUTHWESTERN CONUS BY THURSDAY. AS THIS MOVES EAST THIS WILL PROBABLY RESULT IN ANOTHER CONVECTIVELY ACTIVE PATTERN FOR THE LATTER HALF OF THE WEEK. AS IS TYPICALLY THE CASE AT THAT TIME RANGE MODEL GUIDANCE DIFFERS IN TIMING AND AMPLITUDE BUT THE SIGNAL IS THERE FOR A SCENARIO FAVORING A NORTH/WEST SURGE OF LOW LEVEL MOISTURE AND FORCING FOR ASCENT RESULTING IN ABOVE CLIMO PRECIPITATION PROBABILITIES AND THE POSSIBILITY OF SEVERE THUNDERSTORMS BY MID AND ESPECIALLY LATE WEEK. EVEN BEFORE THEN THERE WILL BE A FEW OPPORTUNITIES FOR PRECIPITATION EARLIER IN THE WEEK AS DIFFICULT TO RESOLVE SMALL SHORTWAVE TROUGHS WITHIN MEAN WEST-NORTHWESTERLY FLOW CROSS THE AREA. CONVECTION MAY EMANATE FROM THE HIGHER TERRAIN OF COLORADO AND NEW MEXICO AND MOVE INTO THE PANHANDLES LATE MONDAY AND AGAIN LATE TUESDAY...ALTHOUGH THIS FORECAST WILL BE LESS DETERMINISTIC WITH TIMING OF HIGHER PROBABILITIES OF PRECIPITATION AND MORE BROAD BRUSH GIVEN INHERENT UNCERTAINTIES OF THIS TYPE PATTERN. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 15/06
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
857 PM CDT SAT APR 18 2015 .DISCUSSION... WATCHING A LINE OF STRONG/SEVERE STORMS HEADING TOWARD OUR WESTERN COUNTIES THIS EVENING. AT THIS TIME...SPC WAS NOT PLANNING ON ISSUING ANY WATCHES WITH THIS STORM COMPLEX. IF THE LATEST RUN OF THE HRRR IS CORRECT...EXPECT THESE STORMS TO WEAKEN AS THEY MOVE INTO AND ACROSS OUR AREA. 42 && .PREV DISCUSSION... /ISSUED 610 PM CDT SAT APR 18 2015/ DISCUSSION... SEE 00Z AVIATION DISCUSSION. AVIATION... SOUTHERN TAF SITES WILL ENDURE AN HOUR OR SO OF TSRA BUT AFTER THAT THINGS LOOK TO FINALLY SETTLE DOWN. A DISTURBANCE OVER CENTRAL TEXAS WILL MOVE EAST THIS EVENING AND COULD BRING A BAND OF SHRA/TSRA ACROSS THE NORTHERN TAF SITES DURING THE MID EVENING. THE HRRR INITIALIZED REASONABLY WELL AND HAVE LEANED TOWARD THAT MODEL FOR TSRA CHANCES TONIGHT. FCST SOUNDINGS SHOW SOME POTENTIAL FOR CLEARING SKIES LATER TONIGHT. THE GROUND REMAINS SATURATED AND IF SKIES CLEAR...FEEL THE POTENTIAL FOR FOG...SOME LOCALLY DENSE WILL BE HIGH. 43 PREV DISCUSSION... /ISSUED 445 PM CDT SAT APR 18 2015/ DISCUSSION... SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS... LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER THREATS. 42 PREV DISCUSSION... /ISSUED 340 PM CDT SAT APR 18 2015/ DISCUSSION... THE UPPER LOW OVER EASTERN CO WILL OPEN UP AND SHEAR OUT OVER THE PLAINS DURING THE NEXT DAY OR TWO. A COUPLE OF SHORTWAVE TROUGHS MOVING OVERHEAD WILL BRING SCATTERED THUNDERSTORMS ACROSS SE TX DURING A COUPLE OF EPISODES TONIGHT...THE FIRST DURING THE LATE AFTERNOON AND EARLY EVENING AND THE SECOND FROM LATE EVENING INTO THE OVERNIGHT PERIOD. CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED OR STRONG THUNDERSTORM. ALTHOUGH THE MAIN STORM ACTION WELL OFFSHORE OF THE COAST HAS BEEN STEALING MOST OF THE INFLOW MOISTURE...THE LATEST SATELLITE TRENDS INDICATE THAT THE STORMS NEAR MATAGORDA BAY WERE BEGINNING TO EXHIBIT COOLING CLOUD TOPS. THERE IS ALSO A SLIGHT CHANCE THAT THE STORMS OVER THE FAR SOUTHWESTERN SET OF COUNTIES MAY CONTAIN LOCALLY HEAVY RAINFALL DURING THE REMAINING AFTERNOON HOURS. THE SECOND ROUND OF STORMS WAS BEING FORECASTED BY THE HRRR AND TEXAS TECH WRF TO MOVE OVER THE NORTHWESTERN AND NORTHERN SET OF COUNTIES BETWEEN ABOUT 9 PM AND 2 AM OR SO. RAP FORECAST SOUNDING SHOW THE POTENTIAL FOR ISOLATED STRONG OR SEVERE STORMS WITH THESE AS WELL. HIGH PRESSURE SHOULD THEN BUILD OVERHEAD SUNDAY AND MONDAY AND LOWER THE RAIN CHANCES. BOTH THE GFS AND ECMWF AGREE WITH ONSHORE WINDS AND RAIN CHANCES RETURNING BY WEDNESDAY. MARINE... AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING. SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE PUSHES OFF TO THE EAST. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 63 85 56 75 54 / 50 20 10 10 20 HOUSTON (IAH) 64 85 61 78 57 / 50 20 20 10 10 GALVESTON (GLS) 69 81 66 77 66 / 50 20 20 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...42
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
615 PM CDT SAT APR 18 2015 .AVIATION... A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED UNDER THE COLD CORE OF THE LOW...SO HAVE ENTERED SOME GUSTY SHOWERS INTO THE TAFS FOR THIS EVENING. NORTHWEST WINDS WILL GENERALLY REMAIN AT 10 KNOTS OR LESS OUTSIDE OF THE SHOWERS. NORTHWEST TO NORTH WINDS WILL THEN PICK UP TO 25 TO 30 KNOTS WITH HIGHER GUSTS BY MID MORNING ON SUNDAY. SKIES SHOULD REMAIN VFR. && .PREV DISCUSSION... /ISSUED 521 PM CDT SAT APR 18 2015/ UPDATE... WEST TEXAS MESONET AND SCHOOL NET OBSERVATIONS SHOW A CONTINUED DECREASE IN SURFACE DEW POINTS AND VEERING OF SURFACE WINDS ACROSS THE FAR EASTERN PORTION OF THE TEXAS PANHANDLE. SPC RAP MESOANALYSIS HAS RESPONDED BY DEPICTING MUCH HIGHER LCL HEIGHTS THAT ARE LESS FAVORABLE FOR TORNADOES. A MORE FAVORABLE ENVIRONMENT EXISTS FURTHER EAST INTO OKLAHOMA WHERE SURFACE WINDS REMAINED BACKED AND AT LEAST SHALLOW LOW LEVEL MOISTURE /DEW POINTS IN THE MID TO UPPER 50S/ IS PRESENT. A FAIRLY POTENT VORT MAX IS MOVING ACROSS THE TEXAS PANHANDLE NOW AS SEEN ON WATER VAPOR LOOP AND THIS MAY RESULT IN AN UPTICK IN CONVECTION OVER THE NEXT COUPLE OF HOURS. HAIL AND WIND ARE STILL POSSIBLE WITH THE STRONGEST STORMS AS ENOUGH INSTABILITY REMAINS INTO EARLY EVENING. WILL CONTINUE TO MONITOR TRENDS IN THE OBSERVATIONS...ESPECIALLY LATER THIS EVENING WHEN MIXING SUBSIDES AND THE DRYLINE POSSIBLY SHIFTS WESTWARD SOME. THE BEST CHANCE OF BETTER LOW LEVEL MOISTURE RETURNING TO THE FORECAST AREA WILL BE ACROSS WHEELER AND COLLINGSWORTH COUNTIES. BRB PREV DISCUSSION... /ISSUED 221 PM CDT SAT APR 18 2015/ DISCUSSION... EARLY THIS AFTERNOON A DEEP CLOSED LOW WAS SITUATED OVER EASTERN COLORADO AND SLOWLY MOVING EAST. A BAND OF CLOUDS ASSOCIATED WITH A RELATIVELY POTENT VORT LOBE ROTATING AROUND THE MID-UPPER LOW WAS EVIDENT IN IR/VIS SATELLITE. SURFACE OBSERVATIONS SHOW LIGHT RAIN BENEATH THIS BAND OF CLOUDS AT CLAYTON NEW MEXICO AND PRESUMABLY FURTHER SOUTH-SOUTHWEST EAST OF TUCUMCARI INTO THE FAR WESTERN TEXAS PANHANDLE WHERE LIGHT ECHOS WERE PRESENT ON REGIONAL RADAR MOSAIC. FURTHER EAST ACROSS THE TEXAS AND OKLAHOMA PANHANDLE LOW CLOUDS HAVE DIMINISHED AND/OR SHIFTED INTO OKLAHOMA AS SURFACE WINDS CONTINUE TO VEER SLIGHTLY. SHALLOW LOW LEVEL MOISTURE SEEN ON 12Z KAMA SOUNDING REMAINS ACROSS THE EASTERN PANHANDLES EAST OF A DIFFUSE DRYLINE. THERE REMAINS SOME UNCERTAINTY ON THE POSITION OF THE DRYLINE THAT IS EXPECTED TO SHARPEN THIS AFTERNOON AS DIABATIC HEATING/MIXING COMMENCES. USING SHORT RANGE MODEL FORECAST SOUNDINGS AS GUIDANCE ON THE DEPTH OF MOISTURE OFF THE CAPROCK AND ESPECIALLY FURTHER EAST NEAR THE OKLAHOMA BORDER LEADS TO FAIRLY HIGH CONFIDENCE ON THE PREVIOUS FORECAST WHICH RELEGATES ANY SUBSTANTIAL DEEP CONVECTION TO NEAR OR JUST EAST OF THE OKLAHOMA STATE LINE LATER THIS AFTERNOON. LOW LEVEL MOISTURE IS DEEPER FROM THERE EASTWARD INTO OKLAHOMA AND THUS DRYLINE CIRCULATION THAT DEVELOPS STANDS A BETTER CHANCE AT INITIATING CONVECTION THERE THAN WAS THE CASE FURTHER WEST YESTERDAY. SO THROUGH THE LATE AFTERNOON AND EVENING THERE IS ONLY A LOW PROBABILITY OF ISOLATED-SCATTERED CONVECTION ACROSS THE EXTREME EASTERN PORTION OF THE PANHANDLES WITH BETTER CHANCES OUT OF THE FORECAST AREA ACROSS WESTERN OKLAHOMA. IF THE ABOVE ASSESSMENT IS MISPLACED SLIGHTLY EAST THAN ANY STORM THAT DOES DEVELOP ON OUR SIDE OF THE STATE LINE WOULD HAVE THE POTENTIAL TO BECOME SEVERE DUE TO MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR OF AROUND 30 KNOTS FOR STORM ORGANIZATION/PERSISTENCE. LARGE HAIL WOULD BE THE PRIMARY THREAT INTO THE EVENING GIVEN STEEP MID LEVEL LAPSE RATES OWING TO THE APPROACHING MID-UPPER LOW. WILL CONTINUE TO MONITOR TRENDS IN SURFACE OBSERVATIONS AND DRYLINE EVOLUTION THROUGHOUT THE AFTERNOON. FURTHER WEST OF THE DRYLINE...DEEP MIXING WILL OCCUR GENERALLY EAST OF THE AFOREMENTIONED BAND OF LOW-MID CLOUDS NOW ENTERING THE TEXAS PANHANDLE. CU FIELD IS INCREASING IMMEDIATELY AHEAD OF THIS. BASES SHOULD BECOME RELATIVELY HIGH AS MIXED LAYER DEEPENS THROUGH THE AFTERNOON. WITH FORCING FROM PREVIOUSLY MENTIONED VORT LOBE CONVECTION MAY BECOME DEEP ENOUGH FOR SHOWERS AND THUNDERSTORMS FOR MUCH OF THE AREA LATER THIS AFTERNOON. IF CONVECTION BECOMES DEEP ENOUGH FOR CHARGE SEPARATION AND LIGHTNING...LIMITED INSTABILITY SHOULD PRECLUDE THE THREAT OF SEVERE THUNDERSTORMS. PROGNOSTICATIONS FROM THE HI-RES CONVECTION ALLOWING GUIDANCE INCLUDING THE HRRR AND TTU WRF SEEM TO LINE UP WELL WITH THE ABOVE THINKING. AS THE MID-UPPER LOW CONTINUES TO SHIFT EAST A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. MODEL GUIDANCE IS IN AGREEMENT IN AN EVOLUTION OF THE LOW INTO A MORE OPEN AND PROGRESSIVE WAVE THAT WILL BE EAST OF THE AREA BY TOMORROW AFTERNOON. AN AREA OF MOISTURE ON THE BACK SIDE OF THIS EVOLVING SHORTWAVE TROUGH FAVORABLY TIMED WITH PEAK HEATING SHOULD BE ENOUGH FOR EXTENSIVE CUMULUS DEVELOPMENT DURING THE AFTERNOON POSSIBLY ENOUGH FOR BROKEN SKY CONDITIONS ESPECIALLY ACROSS THE EASTERN PORTION OF THE AREA. DEPTH OF CONVECTION IN ROUGHLY THE NORTHEAST THIRD WILL NEED TO BE MONITORED AS IT MAY BECOME SUFFICIENT FOR A FEW SHOWERS GIVEN RESIDUAL COOL MID LEVEL TEMPERATURES AND RELATIVELY HIGH TQ INDEX VALUES. ADJUSTED LOW POPS ON SUNDAY AFTERNOON TO EXTEND A BIT FURTHER SOUTH AND WEST TO ACCOUNT FOR THIS. EARLY NEXT WEEK A SPLIT UPPER FLOW PATTERN WILL EXIST WITH STRONG PERIODICALLY PERTURBED WESTERLY SOUTHERN BRANCH JUST SOUTH OF US AND NORTHWESTERLY NORTHERN BRANCH ACROSS THE CENTRAL PLAINS. MEAN RIDGING WILL BE PRESENT OVER THE WESTERN STATES. GRADUALLY INCREASING 500 MB HEIGHTS AND A SLIGHTLY MORE AMPLIFIED PATTERN WILL EVOLVE THROUGH THE WEEK ESPECIALLY AS ANOTHER CLOSED LOW DEVELOPS AND DEEPENS OVER THE SOUTHWESTERN CONUS BY THURSDAY. AS THIS MOVES EAST THIS WILL PROBABLY RESULT IN ANOTHER CONVECTIVELY ACTIVE PATTERN FOR THE LATTER HALF OF THE WEEK. AS IS TYPICALLY THE CASE AT THAT TIME RANGE MODEL GUIDANCE DIFFERS IN TIMING AND AMPLITUDE BUT THE SIGNAL IS THERE FOR A SCENARIO FAVORING A NORTH/WEST SURGE OF LOW LEVEL MOISTURE AND FORCING FOR ASCENT RESULTING IN ABOVE CLIMO PRECIPITATION PROBABILITIES AND THE POSSIBILITY OF SEVERE THUNDERSTORMS BY MID AND ESPECIALLY LATE WEEK. EVEN BEFORE THEN THERE WILL BE A FEW OPPORTUNITIES FOR PRECIPITATION EARLIER IN THE WEEK AS DIFFICULT TO RESOLVE SMALL SHORTWAVE TROUGHS WITHIN MEAN WEST-NORTHWESTERLY FLOW CROSS THE AREA. CONVECTION MAY EMANATE FROM THE HIGHER TERRAIN OF COLORADO AND NEW MEXICO AND MOVE INTO THE PANHANDLES LATE MONDAY AND AGAIN LATE TUESDAY...ALTHOUGH THIS FORECAST WILL BE LESS DETERMINISTIC WITH TIMING OF HIGHER PROBABILITIES OF PRECIPITATION AND MORE BROAD BRUSH GIVEN INHERENT UNCERTAINTIES OF THIS TYPE PATTERN. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 15/06
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
610 PM CDT SAT APR 18 2015 .DISCUSSION... SEE 00Z AVIATION DISCUSSION. && .AVIATION... SOUTHERN TAF SITES WILL ENDURE AN HOUR OR SO OF TSRA BUT AFTER THAT THINGS LOOK TO FINALLY SETTLE DOWN. A DISTURBANCE OVER CENTRAL TEXAS WILL MOVE EAST THIS EVENING AND COULD BRING A BAND OF SHRA/TSRA ACROSS THE NORTHERN TAF SITES DURING THE MID EVENING. THE HRRR INITIALIZED REASONABLY WELL AND HAVE LEANED TOWARD THAT MODEL FOR TSRA CHANCES TONIGHT. FCST SOUNDINGS SHOW SOME POTENTIAL FOR CLEARING SKIES LATER TONIGHT. THE GROUND REMAINS SATURATED AND IF SKIES CLEAR...FEEL THE POTENTIAL FOR FOG...SOME LOCALLY DENSE WILL BE HIGH. 43 && .PREV DISCUSSION... /ISSUED 445 PM CDT SAT APR 18 2015/ DISCUSSION... SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS... LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER THREATS. 42 PREV DISCUSSION... /ISSUED 340 PM CDT SAT APR 18 2015/ DISCUSSION... THE UPPER LOW OVER EASTERN CO WILL OPEN UP AND SHEAR OUT OVER THE PLAINS DURING THE NEXT DAY OR TWO. A COUPLE OF SHORTWAVE TROUGHS MOVING OVERHEAD WILL BRING SCATTERED THUNDERSTORMS ACROSS SE TX DURING A COUPLE OF EPISODES TONIGHT...THE FIRST DURING THE LATE AFTERNOON AND EARLY EVENING AND THE SECOND FROM LATE EVENING INTO THE OVERNIGHT PERIOD. CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED OR STRONG THUNDERSTORM. ALTHOUGH THE MAIN STORM ACTION WELL OFFSHORE OF THE COAST HAS BEEN STEALING MOST OF THE INFLOW MOISTURE...THE LATEST SATELLITE TRENDS INDICATE THAT THE STORMS NEAR MATAGORDA BAY WERE BEGINNING TO EXHIBIT COOLING CLOUD TOPS. THERE IS ALSO A SLIGHT CHANCE THAT THE STORMS OVER THE FAR SOUTHWESTERN SET OF COUNTIES MAY CONTAIN LOCALLY HEAVY RAINFALL DURING THE REMAINING AFTERNOON HOURS. THE SECOND ROUND OF STORMS WAS BEING FORECASTED BY THE HRRR AND TEXAS TECH WRF TO MOVE OVER THE NORTHWESTERN AND NORTHERN SET OF COUNTIES BETWEEN ABOUT 9 PM AND 2 AM OR SO. RAP FORECAST SOUNDING SHOW THE POTENTIAL FOR ISOLATED STRONG OR SEVERE STORMS WITH THESE AS WELL. HIGH PRESSURE SHOULD THEN BUILD OVERHEAD SUNDAY AND MONDAY AND LOWER THE RAIN CHANCES. BOTH THE GFS AND ECMWF AGREE WITH ONSHORE WINDS AND RAIN CHANCES RETURNING BY WEDNESDAY. MARINE... AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING. SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE PUSHES OFF TO THE EAST. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 79 63 85 56 75 / 50 50 20 10 10 HOUSTON (IAH) 80 64 85 61 78 / 50 50 20 20 10 GALVESTON (GLS) 77 69 81 66 77 / 50 50 20 20 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...42 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
321 PM CDT FRI APR 17 2015 .SHORT TERM... DRYLINE AT 19Z EXTENDED FROM JUST WEST OF SILVERTON SOUTH TO WHITE RIVER LAKE AND NEAR LAKE ALAN HENRY. THIS BOUNDARY HAS BEEN FORCED WEST ALL DAY BY CONVECTIVE OUTFLOWS FARTHER EAST AND RECENT RUNS OF THE RUC HAVE THE DRYLINE ARRIVING ALONG INTERSTATE 27 BY THIS EVENING...PERHAPS MUCH SOONER. INSTABILITY-WISE...A NARROW AXIS OF SBCAPE AROUND 1000 J/KG MAY FULFILL SOME TSTORMS ALONG AND EAST OF THE DRYLINE THROUGH THE EVENING...BUT VISUAL TRENDS OF TOWERING AND MODERATE CU SUGGEST DEEPER ASCENT IS LACKING. WATER VAPOR IMAGERY INDICATE THIS AREA IS BATTLING SUBSIDENCE ALOFT DUE TO AN AXIS OF PERSISTENT DEEP CONVECTION 60-100 MILES FARTHER EAST. BECAUSE OF THIS AND LIMITED NWP SUPPORT...POPS HAVE BEEN SCALED BACK TO SLIGHT CHANCE FOR MOST AREAS OFF THE CAPROCK. AS THE FOUR CORNERS LOW BEGINS LIFTING NORTHEAST TONIGHT...LOWER TROPOSPHERIC WINDS WILL VEER MORE WESTERLY ACROSS THE WESTERN HALF OF THE CWA AND HELP TO NUDGE THE DRYLINE EASTWARD BEFORE DAYBREAK SAT. MODELS AGREE THE DRYLINE WILL MIX OUT OF OUR EASTERN ZONES BY MIDDAY AHEAD OF BREEZY SW WINDS...BUT ANY DISRUPTION TO THIS SUCH AS WE SAW TODAY WITH CONVECTIVE OUTFLOWS COULD SUPPORT A MORE WESTERLY DRYLINE LOCATION AND NECESSITATE MODIFICATIONS TO OUR DRY FORECAST FOR SATURDAY. WHEREVER THE DRYLINE ENDS UP...DEEP CONVECTION SHOULD EASILY UNFOLD BY SAT AFTN UNDER WEAK INHIBITION...STRONGER CYCLONIC FLOW AND A FAVORABLE MID-LEVEL COLD POCKET OF -20C AT 500MB. .LONG TERM... COLD FRONT PROGGED TO MOVE THROUGH THE FCST AREA SUNDAY MORNING WITH ENOUGH COLD ADVECTION TO RESULT IN HIGHS MAINLY UPPER 60S AND LOWER 70S WHILE ALSO SCOURING LOW LEVEL MOISTURE OUT OF THE FCST AREA. MAY SEE SOME CONVECTION ATTEMPT TO DEVELOP ON THE HIGH TERRAIN OF NRN NM/SRN COLO AND BE DRIVEN TO THE SE ON NWLY UPPER FLOW...BUT WITH DRY LOW LEVELS WOULD EXPECT IT TO HAVE A HARD TIME GETTING THIS FAR TO THE SE. SITUATION CHANGES SOME MONDAY WHEN SOUTH AND SE WINDS BEGIN TO BRING MOISTURE BACK INTO THE AREA. LOOKS LIKE HIGH TERRAIN CONVECTION WILL HAVE A BETTER CHANCE OF MOVING THROUGH THE PANHANDLE AND INTO NRN PARTS OF THE FCST AREA. THE MIDDLE PART OF THE WEEK WILL THEN BE ONE WITH POSSIBILITY OF WEAKLY-FORCED DIURNAL DRYLINE STORMS WITH LOW LEVEL MOISTURE INCREASING WITH TIME...CONFLUENT FLOW ALOFT TRANSITIONING TO WEAK UPPER RIDGING. 20-30 PCT STORM CHANCES TUESDAY THROUGH FRIDAY LOOK FINE WITH THIS SYNOPTIC SETUP. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 72 40 70 40 / 10 0 0 10 TULIA 76 43 73 44 / 20 0 0 10 PLAINVIEW 77 44 73 45 / 20 0 0 0 LEVELLAND 75 43 75 46 / 10 0 0 0 LUBBOCK 78 45 76 47 / 20 0 0 0 DENVER CITY 74 44 74 47 / 0 0 0 0 BROWNFIELD 76 45 76 48 / 10 0 0 0 CHILDRESS 68 55 79 51 / 50 20 10 10 SPUR 78 53 79 50 / 40 20 0 0 ASPERMONT 74 56 81 52 / 50 20 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 93/07
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1215 AM CDT FRI APR 17 2015 .DISCUSSION... 06Z TAF DISCUSSION IN AVIATION SECTION... && .AVIATION... CONVECTION STILL ONGOING SO START TARS WITH TSRA/VCTS UNTIL 09Z WHEN HRRR TRENDS SHOW CONVECTION ENDING. SHOULD HAVE MVFR TYPE CITS AFTER THAT WITH RAIN COOLED AIRMASS BUT NOT MUCH OTHER CLEARING. CIGS LIFT TO VFR LATE MORNING THROUGH AFTERNOON. BASED ON GFS/ECMWF AND WRF RUNS...POSSIBLE MCS MOVING INTO THE AREA LATE EVENING/FRI NIGHT TIME FRAME. START VCTS AT 22Z UNTIL 04Z TO HIGHLIGHT THAT THREAT. 39 && .PREV DISCUSSION... /ISSUED 953 PM CDT THU APR 16 2015/ UPDATE... VERY BUSY EVENING AS ADVERTISED. CATEGORICAL POPS IN ORDER THROUGH MID NIGHT AREA WIDE...OUTSIDE OF THE COAST/SWRN COUNTIES BEHIND MAIN AREA OF CONVECTION. LATEST MESO ANALYSIS INDICATES PRIMARY/EFFECTIVE WARM FRONT ESTABLISHED ROUGHLY ALONG AND JUST SOUTH OF I-10 WITH ABUNDANT MOISTURE /SURFACE DEWPOINTS IN THE LOWER 70S/ IN PLACE ACROSS THE WARM SECTOR. SPC HAS TORNADO WATCH IN EFFECT AS ACTIVITY NEAR AND SOUTH OF THIS FRONT INGESTS MODERATELY UNSTABLE AND WEAKLY CAPPED WARM SECTOR AIR. THIS WILL INCREASE THE POTENTIAL FOR SPIN UPS UNTIL THE WARM SECTOR ITSELF BEGINS TO CAP OFF LATER TONIGHT. IMPRESSIVE FEED OF MOISTURE WILL SUSTAIN THREAT OF HEAVY RAIN WITH ANY ACTIVITY AREA WIDE. CURRENTLY FFA IS CONFINED TO THE WARM SECTOR WHERE MOST ABUNDANT FEED OF MOISTURE SHOULD CONFINE THE MOST INTENSE RAINFALL RATES. HOWEVER FLOODING REMAINS A CONCERN AREA WIDE GIVEN THE EVENING RAINFALL ACROSS SOME NRN AREAS. THUS...FEEL FFA IS WARRANTED ACROSS THE CWA THROUGH THE DAY TOMORROW AND WILL EXPAND. WITH ANOTHER POSSIBLE LATE DAY/EVENING MCS...FFA MAY NEED TO BE EXTENDED IN LATER FORECASTS THROUGH THE NIGHT FRIDAY/SATURDAY MORNING. PREV DISCUSSION... /ISSUED 659 PM CDT THU APR 16 2015/ DISCUSSION... 00Z TAF DISCUSSION IN AVIATION... AVIATION... MAIN CONCERN IS OBVIOUSLY CONVECTION. LOOKS LIKE CONVECTION WILL BE ENDING THROUGH 02-03Z...WILL HOLD ONTO VCTS/TSRA FOR MOST TAF SITES AS CONVECTION WANES. BASED ON HRRR TRENDS MAY KEEP SOME VCSH GOING THROUGH THE NIGHT IF ANYTHING RE-DEVELOPS. CONFIDENCE IS NOT VERY HIGH ON THIS SO ANTICIPATE AMMENDING TAFS TO REMOVE CONVECTION IN THE SHORT TERM. CIGS SHOULD BE VFR/MVFR OVERNIGHT INTO TOMORROW MORNING. BASED ON WRF-ARW/TX TECH WRF AND EVEN SUPPORTED BY GFS...EXPECT LARGE MCS TO MOVE INTO THE AREA IN THE EVENING SO ADDED MENTION OF VCTS FOR TAFS. STILL TIME TO WORK OUT THESE DETAILS AND LIKELY BE FOCUS OF 06Z TAFS. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 66 79 63 83 59 / 60 50 40 20 20 HOUSTON (IAH) 67 80 64 84 63 / 60 50 40 20 20 GALVESTON (GLS) 70 76 69 78 68 / 60 50 40 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS... COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS... HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA... MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER... WALLER...WASHINGTON...WHARTON. GM...SMALL CRAFT ADVISORY UNTIL 4 AM CDT EARLY THIS MORNING FOR THE FOLLOWING ZONES: GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...33 AVIATION/MARINE...39
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
932 PM EDT SAT APR 18 2015 .SYNOPSIS... HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK. && .NEAR TERM /THROUGH SUNDAY/... AS OF 912 PM EDT SATURDAY STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS. PREVIOUS DISCUSSION... AS OF 300 PM EDT SATURDAY WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR POPS IN THE FORECAST. ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT. A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE CRITERIA. PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND EAST...IF HIGHER QPF TRENDS CONTINUE. CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... AS OF 335 PM EDT SATURDAY... HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF 20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME. UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE TO 70 EVEN TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 350 PM EDT SATURDAY... MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE CONCERN AT THIS POINT. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... AS OF 735 PM EDT SATURDAY... ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY WITH LOSS OF HEATING. MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE. A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND SHEAR. CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT. WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES. EXTENDED AVIATION... A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS. THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE IN THE MOUNTAINS ON WEDNESDAY. && .HYDROLOGY... AS OF 330 PM EDT SATURDAY... ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%. THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW 3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS. WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE MODEL TRENDS OF INCREASING QPF WITH EACH RUN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR VAZ015>017-032. NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR NCZ001>003-018>020. WV...NONE. && $$ SYNOPSIS...PH NEAR TERM...PH/RCS SHORT TERM...RAB LONG TERM...RAB AVIATION...PC/PH HYDROLOGY...PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
742 PM EDT SAT APR 18 2015 .SYNOPSIS... HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK. && .NEAR TERM /THROUGH SUNDAY/... AS OF 712 PM EDT SATURDAY A FEW ISOLATED SHOWERS AND THUNDERSTORMS POPPED UP THIS AFTERNOON...MAINLY SOUTH OF HIGHWAY 460 IN THE WEST AND SOUTH OF THE VA-NC BORDER EAST. THIS CONVECTION WILL FADE WITH LOSE OF HEATING THIS EVENING. RAIN CHANCES WILL INCREASE OVERNIGHT AS A STRONG AREA OF LOW PRESSURE APPROACHES THE REGION. PREVIOUS DISCUSSION... AS OF 300 PM EDT SATURDAY WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR POPS IN THE FORECAST. ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT. A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE CRITERIA. PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND EAST...IF HIGHER QPF TRENDS CONTINUE. CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... AS OF 335 PM EDT SATURDAY... HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF 20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME. UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE TO 70 EVEN TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 350 PM EDT SATURDAY... MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE CONCERN AT THIS POINT. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... AS OF 735 PM EDT SATURDAY... ISOLATED SHOWERS ALONG THE BLUE RIDGE SHOULD DISSIPATE SHORTLY WITH LOSS OF HEATING. MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS TO LOWER TO MVFR ON THE 06-09Z TIME RANGE. A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND SHEAR. CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT. WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION ARRIVES. EXTENDED AVIATION... A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE AHEAD OF AND ALONG IT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS. THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE IN THE MOUNTAINS ON WEDNESDAY. .HYDROLOGY... AS OF 330 PM EDT SATURDAY... ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%. THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW 3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS. WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE MODEL TRENDS OF INCREASING QPF WITH EACH RUN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR VAZ015>017-032. NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR NCZ001>003-018>020. WV...NONE. && $$ SYNOPSIS...PH NEAR TERM...PH/RCS SHORT TERM...RAB LONG TERM...RAB AVIATION...PC/PH HYDROLOGY...PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
712 PM EDT SAT APR 18 2015 .SYNOPSIS... A RIDGE OF HIGH PRESSURE OVER OUR AREA TODAY WILL MOVE EAST ALLOWING A MOISTURE EASTERLY FLOW TO DEVELOP TONIGHT. A COMPLEX STORM SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN...HEAVY AT TIMES...SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK. && .NEAR TERM /THROUGH SUNDAY/... AS OF 712 PM EDT SATURDAY A FEW ISOLATED SHOWERS AND THUNDERSTORMS POPPED UP THIS AFTERNOON...MAINLY SOUTH OF HIGHWAY 460 IN THE WEST AND SOUTH OF THE VA-NC BORDER EAST. THIS CONVECTION WILL FADE WITH LOSE OF HEATING THIS EVENING. RAIN CHANCES WILL INCREASE OVERNIGHT AS A STRONG AREA OF LOW PRESSURE APPROACHES THE REGION. PREVIOUS DISCUSSION... AS OF 300 PM EDT SATURDAY WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR POPS IN THE FORECAST. ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT. A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE CRITERIA. PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND EAST...IF HIGHER QPF TRENDS CONTINUE. CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... AS OF 335 PM EDT SATURDAY... HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF 20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME. UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE TO 70 EVEN TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 350 PM EDT SATURDAY... MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE CONCERN AT THIS POINT. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... AS OF 120 PM EDT SATURDAY... VFR CONDITIONS WERE NOTED AT ALL THE TAF SITES EARLY THIS AFTERNOON...BUT FLYING CONDITIONS ARE FORECAST TO DETERIORATE DURING THE OVERNIGHT HOURS/EARLY MORNING SUNDAY. FOR THE REMINDER OF TODAY...WEAK CONVERGENCE AND UPSLOPE MAY GENERATE ISOLD SHWRS OR TSTORMS THIS AFTERNOON...ESPECIALLY NEAR BLUE RIDGE ALONG OR SOUTH OF VA/NC BORDER...BUT PROBABILITY IS TOO LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME. MODELS HAVE BEEN CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS TO LOWER TO MVFR AFTER 08Z. HIGHEST CONFIDENCE IN MVFR CEILINGS IS AT KBCB AFTER 08Z/2AM. A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS AT KLBF EARLY SUNDAY AND CONTINUE THROUGH 18Z. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...THESE STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE AND KBCB AND KLWB...BUT WILL CREATE POTENTIALLY HAZARDOUS LOW LEVEL WIND SHEAR CONDITIONS. KROA WILL BE NEED TO BE CAREFULLY MONITORED TO POSSIBLE INCLUSION OF LL WIND SHEAR. CIGS WILL CONTINUE TO DROP AND RAIN WILL BECOME WIDESPREAD DURING THE DAY SUNDAY...AS A STRONG UPSLOPE FLOW TRANSPORTS ABUNDANT MOISTURE INTO THE REGION NORTH OF A NEARLY STATIONARY FRONT. WIDESPREAD IFR CONDITIONS ARE FORECAST IN THE MOUNTAINS AND FOOTHILLS...WITH MVFR CIGS AT KLYH AND KDAN LIKELY DETERIORATING AFTER 18Z SUNDAY WHEN THE HEAVIEST PRECIPITATION MOVES ARRIVES. EXTENDED AVIATION... A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION SUNDAY WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN INTO SUNDAY NIGHT. THIS WILL BE FOLLOWED BY ANOTHER COLD FRONT MONDAY. THIS IS LIKELY TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS. THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE IN THE MOUNTAINS ON WEDNESDAY. .HYDROLOGY... AS OF 330 PM EDT SATURDAY... ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%. THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW 3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS. WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE MODEL TRENDS OF INCREASING QPF WITH EACH RUN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR VAZ015>017-032. NC...FLOOD WATCH FROM 4 AM EDT SUNDAY THROUGH SUNDAY EVENING FOR NCZ001>003-018>020. WV...NONE. && $$ SYNOPSIS...PH NEAR TERM...PH/RCS SHORT TERM...RAB LONG TERM...RAB AVIATION...AMS/PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
636 PM EDT FRI APR 17 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND SATURDAY BRINGING DRY AND WARM WEATHER FOR THE START OF THE WEEKEND. A COMPLEX STORM SYSTEM PASSING TO THE WEST WILL RESULT IN MORE WIDESPREAD RAIN SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 635 PM EDT FRIDAY... UPDATE TO REFLECT CURRENT MAINLY ISOLD COVERAGE OF SHOWERS FROM FOOTHILLS INTO SOUTHSIDE VA. INCLUDED A COUPLE HOURS OF CHC POPS ACROSS SOUTHSIDE THROUGH EARLY EVENING WITH CLUSTER OF SHOWERS THERE...AND SO FAR NOT SEEING ANY SIGNS OF EVEN INTERCLOUD LIGHTNING WITH CELLS NEAR MTV AND DAN...BUT KEEPING ISOLD THUNDER IN FCST GIVEN SBCAPES OF 500-800 J/KG....AND SOME ISOL LTG IN CELLS JUST NORTHEAST OF BUCKINGHAM COUNTY. ALL THIS ACTIVITY SHOULD SLOWLY DIMINISH AS IT DRIFTS SOUTHEASTWARD INTO FAR NORTHERN NC BY 8 OR 9PM...AND RECENT HRRR RUNS SEEM TO BE DOING A BETTER JOB CAPTURING THE SPARSITY OF THE SHALLOW CONVECTION AND WEAKENING INTO THE EVENING HOURS WITH LOSS OF HEATING. SOME OF THE MORE WIDESPREAD LIGHT RAIN OVER FAR SW NC AND UPSTATE SC WILL SLIDE TO THE NORTHEAST IN ADVANCE OF WEAK SHORT WAVE HEADING EAST OUT OF TN...BUT PREVIOUS THINKING THAT IT WILL REMAIN SOUTH OF THE FCST AREA STILL LOOKS ON TRACK. WE DO KEEP A LINGERING SLIGHT CHC POP ACROSS NW NC MTNS UNTIL A LITTLE AFTER MIDNIGHT JUST IN CASE...BUT THEN DROP ALL POPS TOWARD MORNING. PREVIOUS DISCUSSION AS OF 235 PM EDT MONDAY... AT 18Z...A WEAK SURFACE TROF WAS NOTED JUST EAST OF THE BLUE RIDGE...AND WEAK CONVERGENCE ALONG THIS BOUNDARY COMBINED WITH SOME MODEST INSTABILITY (DCAPES 500-700 J/KG) SHOULD GENERATE ISOLATED SHOWERS AND STORMS ALONG THE BLUE RIDGE AS WELL AS AREAS NORTH OF I- 64 WHERE VISIBLE SATELLITE SHOWS SOME ENHANCED CUMULUS FORMING IN ADVANCE OF A FAINT UPPER LEVEL DISTURBANCE. MESOSCALE MODELS ARE OVERDONE ON THIS COVERAGE OF THIS PRECIP...BUT GENERALLY HAVE A GOOD HANDLE ON THE LOCATION OF DEVELOPMENT. ANY ISOLATED/WIDELY SCATTERED PRECIP THAT DEVELOPS SHOULD GRADUALLY DIMINISH TONIGHT...BEFORE AN UPPER LEVEL SHORTWAVE IN WEST TENNESSEE ZIPS ACROSS NRN NC LATE TONIGHT. THIS SYSTEM WILL BRING AN INCREASE IN CLOUD COVER...ESPECIALLY ACROSS THE SOUTHERN PORTION OF OUR FORECAST AREA LATE TONIGHT...AND A FEW SHOWERS MAY BE POSSIBLE. AT THE SFC...HIGH PRESSURE WILL SLOWLY NOSE SOUTH INTO THE EASTERN OHIO VALLEY BRINGING A LIGHT NORTH WIND. A SHALLOW LAYER OF MOISTURE NEAR THE SURFACE WILL REMAIN...WHICH WILL RESULT IN POCKETS OF FOG...ESPECIALLY WHERE CLOUDS ARE ABSENT TO THE NORTH. LEANED TOWARD THE WARMER GUIDANCE VALUES WITH CLOUDS. FOR SATURDAY...HEIGHTS BUILD IN ADVANCE OF A DEEP UPPER LEVEL TROF IN THE WEST AND TEMPS SHOULD AGAIN WARM WELL INTO THE 70S AND THE 80S IN THE EAST. A WEAK LOW LEVEL EAST FLOW COMBINED WITH A NOSE OF HIGHER THETA-E AIR IN NW NC INTO FAR SW VA MAY SPARK ISOLATED SHOWERS/STORMS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... AS OF 330 PM EDT FRIDAY... FOCUS THROUGH THIS PERIOD REMAINS ON A STRONG NEGATIVELY TILTED UPPER TROUGH PROGGED TO LIFT RAPIDLY NORTHEAST ACROSS THE REGION SUNDAY INTO EARLY MONDAY. MEANWHILE...ANTECEDENT HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC COAST INTO A NEAR CLASSIC WEDGE POSITION. STRONG PVA/ISENTROPIC LIFT INDUCED RAINFALL INTO THE WEDGE AIR MASS WILL ENHANCE/INTENSIFY THE WEDGE SUNDAY. RAINFALL/QPF WILL BE THE MAIN CONCERN AS THE WEDGE KEEPS A VERY STABLE/COOL AIR MASS IS PLACE. MOIST SOUTHEAST...UPSLOPE FLOW ALONG THE BLUE RIDGE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS WATAUGA NORTHEAST TOWARD FLOYD. AS NOTED YESTERDAY...HOWEVER...THE SYSTEM WILL REMAIN HIGHLY PROGRESSIVE...LIMITING THE PERIOD OF HEAVIER RAINFALL TO 12 HOURS OR LESS. WPC HAS PARTS OF THE NC/VA SOUTHERN VA PIEDMONT OUTLOOKED FOR EXCESSIVE RAINFALL. THE MAIN CONCERN WITHIN THIS AREA WOULD BE WATAUGA THROUGH ASHE/WILKES...WITH LESS CONCERN TOWARD THE DANVILLE AREA WHERE ANTECEDENT CONDITIONS ARE RELATIVELY DRY. IN ADDITION...THE CONVECTIVE THREAT THROUGH THE HEAVIER RAIN PERIOD AS NOTED ABOVE IS MINIMAL TO NONE...WHICH SHOULD FURTHER REDUCE THE FLASH FLOOD THREAT. WILL RE-EVALUATE AGAIN TOMORROW...BUT AT THIS POINT NO NEED FOR A FLOOD/FLASH FLOOD WATCH. ONE MAY EVENTUALLY BE NEEDED FOR A SMALL AREA INCLUDING THE NW NC MOUNTAINS AND THE ADJACENT FOOTHILLS. WENT WELL BELOW GUIDANCE ON MAX TEMPS IN THE WEDGE SUNDAY...BUT AT OR ABOVE GUIDANCE ON MONDAY IN THE WARM SECTOR. MAX TEMPS MONDAY WILL BE A GOOD 20 DEGREES WARMER IN MOST AREAS THAN ON SUNDAY. MONDAY IS A DIFFERENT STORY. A SIGNIFICANT WARM SECTOR WILL SURGE NORTHWARD INTO THE REGION MONDAY AFTERNOON BEHIND THE DEPARTING UPPER TROUGH AND AN APPROACHING STRONG COLD FRONT ASSOCIATED WITH A DEEPENING BROAD UPPER TROUGH ACROSS THE GREAT LAKES. SEVERAL OF THE MODELS CONTINUE TO ADVERTISE GOOD POTENTIAL FOR STRONG THUNDERSTORMS MONDAY AFTERNOON...WITH SIGNIFICANT SVR PARAMETER NEAR 20000 ACROSS THE PIEDMONT...CAPES NEARING 2000 J/KG WITH AT LEAST 20-30KTS OF 0-2KM LOW-LEVEL SHEAR AND LIS NEAR -4C. SPC DAY 4 OUTLOOK SUGGESTS THAT DAMAGING WINDS WOULD BE THE MAIN CONCERN WITH ANY CONVECTION...MOST LIKELY LINEAR ORIENTED...THAT DEVELOPS ALONG/IN ADVANCE OF THE COLD FRONT MONDAY AFTERNOON/EVENING. THIS ACTIVITY QUICKLY MOVES EAST OF THE REGION MON AFTERNOON. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 345 PM EDT FRIDAY... A TRANSITION TO A PATTERN MORE REMINISCENT OF WINTER CONTINUES TO BE IN THE CARDS FOR THE EARLY AND MID PART OF NEXT WEEK AS A DEEP AND BROAD UPPER TROUGH BUILDS INTO THE CENTRAL/EASTERN U.S. BY TUESDAY...500MB HEIGHTS DROP INTO THE 560DM RANGE AND 850MB TEMPS PLUNGE TOWARD THE 0C MARK ACROSS THE NORTH BY MIDWEEK. ANTICYCLONIC FLOW...A SERIES OF EMBEDDED UPPER DISTURBANCES...AND COLD ADVECTION WILL KEEP VARIABLE CLOUDINESS AND POTENTIALLY UPSLOPE SHOWERS IN PLACE ACROSS THE MOUNTAINS. THE CLOUDS AND CYCLONIC FLOW WILL HOLD MAX TEMPS INTO THE 50S AND LOWER 60S ACROSS THE MOUNTAINS THROUGH MUCH OF THE LATER HALF OF NEXT WEEK...WHILE 60S TO 70S PREVAIL TO THE EAST WITH DOWNSLOPE NORTHWEST FLOW AND SIGNIFICANTLY GREATER AMOUNTS OF SUNSHINE. AT THIS POINT A DISTURBANCE ON WED APPEARS TO BE THE MOST SIGNIFICANT IN POTENTIALLY BRINGING SHOWERS EAST OF THE MOUNTAINS. HAVE NOT INTRODUCED ANY THUNDER AT THIS POINT GIVEN THE LOW-LEVEL COLD/STABLE AIR MASS. BY MID-WEEK...THE GFS/ECMWF BEGIN TO DIVERGE ON THE OVERALL PATTERN...WITH THE ECMWF KEEPING THE DEEP UPPER TROUGH IN PLACE ACROSS THE NORTHEAST AND A STRONGER NW FLOW INTO OUR REGION AS WELL...WHILE THE GFS DEPICTS THE UPPER TROUGH LIFTING FURTHER NORTH AND PLACING A ZONAL FLOW WITH A BAROCLINIC ZONE STUCK ACROSS OUR CWA. THIS RESULTS IN SIGNIFICANT DIFFERENCES BETWEEN MOISTURE/POPS ACROSS OUR CWA BETWEEN THE TWO MODELS...WITH THE GFS VERY WET AND THE ECMWF MUCH DRIER...KEEPING THE BAROCLINIC ZONE MUCH FURTHER SOUTH. HAVE JUST ADVERTISED CHC POPS FOR NOW UNTIL A BETTER HANDLE ON THIS PATTERN AND TIMING IS OBTAINED. TEMPERATURES ARE EXPECTED TO REMAIN BELOW NORMAL THROUGH THE MID PART OF THE WEEK...GRADUALLY TRENDING CLOSER TO NORMAL BY THE END OF THE PERIOD. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AS OF 120 PM EDT FRIDAY... VFR WITH A FEW MVFR CIGS WERE NOTED ACROSS THE REGION EARLY THIS AFTERNOON. CLOUDS SHOULD GRADUALLY SCATTERED THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY EVENING HOURS WITH LIGHT WINDS. ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS AFTERNOON...BUT COVERAGE WILL BE VERY LIMITED AND THE CHANCES OF ONE OF THESE STRAY SHOWERS/STORMS IMPACTING A TAF SITE IS SMALL. A SHALLOW LAYER OF LOW LEVEL MOISTURE WILL REMAIN IN PLACE TONIGHT...AND WITH LIGHT WINDS...POCKETS FOG REDUCING VISIBILITIES TO IFR TO MVFR CATEGORIES WILL BE POSSIBLE LATE TONIGHT. HIGH PRESSURE BUILDS NOSING DOWN INTO OUR REGION SATURDAY...WILL USHER IN SLIGHTLY DRIER AIR ALLOWING MORNING FOG/STRATUS TO QUICKLY ERODE...BRINGING VFR CONDITIONS TO ALL AREAS BY MID-MORNING SATURDAY. EXTENDED AVIATION... A COMPLEX STORM SYSTEM WILL BEGIN TO AFFECT THE REGION LATER IN THE WEEKEND WITH A WARM FRONT BRINGING WIDESPREAD MVFR/IFR CONDITIONS IN RAIN SUNDAY/SUNDAY NIGHT FOLLOWED BY ANOTHER COLD FRONTAL PASSAGE MONDAY. THIS LIKELY TO KEEP PERIODS OF MVFR IN PLACE UNTIL THE FRONT POSSIBLY CLEARS THE REGION LATER MONDAY. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH GOOD DRYING EXPECTED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PH NEAR TERM...JH/PH/SK SHORT TERM...RAB LONG TERM...RAB AVIATION...JH/PH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
108 PM CDT FRI APR 17 2015 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND SATURDAY ISSUED AT 400 AM CDT FRI APR 17 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAK COLD FRONT SLOWLY MOVING TO THE SOUTHEAST OVER FAR NORTHWEST WISCONSIN. AHEAD OF THE FRONT...AREAS OF BROKEN MID-CLOUDS ARE MOVING TO THE EAST OVER CENTRAL AND NORTHERN WISCONSIN. CLEAR SKIES EXIST BEHIND THIS FRONT OVER THE NORTHERN PLAINS. MEANWHILE...SHOWERS AND THUNDERSTORMS ARE OCCURRING OVER THE CENTRAL PLAINS AHEAD OF AN UPPER LOW SPINNING OVER THE 4 CORNERS REGION. FORECAST CONCERNS INCLUDE HIGH TEMPS AND LOW HUMIDITIES FOR SATURDAY. TODAY...THE COLD FRONT WILL SLOW AS IT WEAKENS OVER THE NORTHWEST THIRD OF THE STATE. SCATTERED TO BROKEN MID-LEVEL CLOUD DECK WILL GRADUALLY DISSIPATE THROUGH THE MORNING AS SUBSIDENCE STRENGTHENS OVERHEAD. WILL STILL BE SOME RESIDUAL MOISTURE LEFT AROUND 800MB...HOWEVER...THAT WILL TURN INTO A CU FIELD BY LATE MORNING OVER CENTRAL TO NORTHEAST WISCONSIN. FAR NORTHERN WISCONSIN WILL SEE AN INFLUX OF DRIER AIR DURING THE AFTERNOON...WHICH WILL DROP HUMIDITIES INTO THE 20 TO 25 PCT RANGE. HUMIDITIES SHOULD BE ABOVE CRITICAL CRITERIA ELSEWHERE. RAISED HIGH TEMPS BASED ON 925MB TEMPS ON THE BETTER PERFORMING NAM AND ECMWF...AND MAY NOT BE HIGH ENOUGH. TEMPS TO MAX OUT TO NEAR 70 NORTH TO THE UPPER 70S IN THE WARM SPOTS. TONIGHT...THE WEAKENING FRONT WILL DROP ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING WHILE A SECONDARY AND MORE POTENT FRONT QUICKLY MOVES SOUTH ACROSS NORTHERN AND CENTRAL WISCONSIN AFTER MIDNIGHT. BEHIND THE SECOND FRONT...WINDS WILL SHIFT TO THE NORTHEAST AND COULD GUST FOR A COUPLE HOURS TO 20 OR 25 MPH. TEMPS WILL ALSO COOL OFF QUICKLY BEHIND THE FRONT WITH LOWS FALLING INTO THE MIDDLE 30S NORTH TO THE MIDDLE 40S SOUTH. SATURDAY...CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE CENTRAL GREAT LAKES. THE AIRMASS ASSOCIATED WITH THIS SURFACE HIGH IS EXCEPTIONALLY DRY (NAM 850-700MB RH FALLS TO 2 PCT!). THOUGH HIGH CLOUDS WILL BE ON THE INCREASE DURING THE AFTERNOON AHEAD OF THE CENTRAL ROCKIES UPPER LOW...SHOULD STILL SEE PLENTY OF SUNSHINE ALBEIT WITH COOLER TEMPERATURES. CRITICAL RELATIVE HUMIDITIES BETWEEN 15 TO 25 PCT WILL STILL OCCUR THOUGH NORTH AND WEST OF THE FOX VALLEY. POTENTIAL IS THERE FOR HUMIDITIES TO FALL LOWER THAN THIS IF TAPPING OCCURS INTO THIS BONE DRY AIR ALOFT. HIGHS MAINLY IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY ISSUED AT 400 AM CDT FRI APR 17 2015 500MB OPEN TROUGH WILL EVOLVE INTO A CLOSED LOW OVER THE WESTERN GREAT LAKES REGION BY EARLY NEXT WEEK. COOL CYCLONIC FLOW WILL CONTINUE FOR THE REMAINDER OF NEXT WEEK AS THE 500MB LOW MEANDERS ACROSS THE GREAT LAKES REGION/EASTERN CANADA. MODELS IN SOMEWHAT BETTER AGREEMENT TONIGHT BRINGING THE BEST CHANCE FOR RAIN SUNDAY INTO SUNDAY NIGHT. WILL CONTINUE A SMALL CHANCE OF SHOWERS AFTER MIDNIGHT ON SATURDAY NIGHT TO ACCOUNT FOR A SLIGHTLY QUICKER ARRIVAL THAT SOME OF THE MODELS ARE DEPICTING. WILL HAVE LIKELY OR LOW END CATEGORICAL CHANCES FOR RAIN ON SUNDAY. HIGH TEMPERATURES TRICKY DEPENDING ON QUICK THE STEADIER RAINS ARRIVE. IF RAIN ARRIVES EARLY IN THE DAY SUNDAY...HIGH TEMPERATURES WILL NEED TO BE LOWERED. COUNTING ON SOME DRY ON BACKSIDE OF THE RETREATING HIGH PRESSURE SYSTEM TO SLOW THE ARRIVAL OF THE RAIN ACROSS EASTERN WISCONSIN. OTHERWISE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE WEEK WITH CHANCES OF RAIN INTO THE MIDDLE OF NEXT WEEK. STILL HAVE A CHANCE OF SNOW LATE AT NIGHT OR EARLY IN THE DAY FOR EACH PERIOD FROM MONDAY NIGHT THROUGH WEDNESDAY. BY THURSDAY...UPPER LOW MAY BE FAR ENOUGH AWAY FOR JUST A SMALL CHANCE OF RAIN ACROSS THE FAR NORTH. PREVIOUS FORECAST TEMPERATURES SEEMED REASONABLE WITH ONLY MINOR CHANGES MADE IN SOME PERIODS. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 108 PM CDT FRI APR 17 2015 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SCATTERED TO BROKEN CUMULUS THIS AFTERNOON SHOULD DISSIPATE AROUND/SHORTLY AFTER SUNSET. A DRY COLD FRONT WILL ARRIVE LATER TONIGHT. WINDS WILL SHIFT TO THE NORTHEAST BEHIND THE FRONT...AND BECOME GUSTY FOR A FEW HOURS...ESPECIALLY IN EASTERN WISCONSIN. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ECKBERG AVIATION.......MG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
604 AM CDT FRI APR 17 2015 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND SATURDAY ISSUED AT 400 AM CDT FRI APR 17 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAK COLD FRONT SLOWLY MOVING TO THE SOUTHEAST OVER FAR NORTHWEST WISCONSIN. AHEAD OF THE FRONT...AREAS OF BROKEN MID-CLOUDS ARE MOVING TO THE EAST OVER CENTRAL AND NORTHERN WISCONSIN. CLEAR SKIES EXIST BEHIND THIS FRONT OVER THE NORTHERN PLAINS. MEANWHILE...SHOWERS AND THUNDERSTORMS ARE OCCURRING OVER THE CENTRAL PLAINS AHEAD OF AN UPPER LOW SPINNING OVER THE 4 CORNERS REGION. FORECAST CONCERNS INCLUDE HIGH TEMPS AND LOW HUMIDITIES FOR SATURDAY. TODAY...THE COLD FRONT WILL SLOW AS IT WEAKENS OVER THE NORTHWEST THIRD OF THE STATE. SCATTERED TO BROKEN MID-LEVEL CLOUD DECK WILL GRADUALLY DISSIPATE THROUGH THE MORNING AS SUBSIDENCE STRENGTHENS OVERHEAD. WILL STILL BE SOME RESIDUAL MOISTURE LEFT AROUND 800MB...HOWEVER...THAT WILL TURN INTO A CU FIELD BY LATE MORNING OVER CENTRAL TO NORTHEAST WISCONSIN. FAR NORTHERN WISCONSIN WILL SEE AN INFLUX OF DRIER AIR DURING THE AFTERNOON...WHICH WILL DROP HUMIDITIES INTO THE 20 TO 25 PCT RANGE. HUMIDITIES SHOULD BE ABOVE CRITICAL CRITERIA ELSEWHERE. RAISED HIGH TEMPS BASED ON 925MB TEMPS ON THE BETTER PERFORMING NAM AND ECMWF...AND MAY NOT BE HIGH ENOUGH. TEMPS TO MAX OUT TO NEAR 70 NORTH TO THE UPPER 70S IN THE WARM SPOTS. TONIGHT...THE WEAKENING FRONT WILL DROP ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING WHILE A SECONDARY AND MORE POTENT FRONT QUICKLY MOVES SOUTH ACROSS NORTHERN AND CENTRAL WISCONSIN AFTER MIDNIGHT. BEHIND THE SECOND FRONT...WINDS WILL SHIFT TO THE NORTHEAST AND COULD GUST FOR A COUPLE HOURS TO 20 OR 25 MPH. TEMPS WILL ALSO COOL OFF QUICKLY BEHIND THE FRONT WITH LOWS FALLING INTO THE MIDDLE 30S NORTH TO THE MIDDLE 40S SOUTH. SATURDAY...CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE CENTRAL GREAT LAKES. THE AIRMASS ASSOCIATED WITH THIS SURFACE HIGH IS EXCEPTIONALLY DRY (NAM 850-700MB RH FALLS TO 2 PCT!). THOUGH HIGH CLOUDS WILL BE ON THE INCREASE DURING THE AFTERNOON AHEAD OF THE CENTRAL ROCKIES UPPER LOW...SHOULD STILL SEE PLENTY OF SUNSHINE ALBEIT WITH COOLER TEMPERATURES. CRITICAL RELATIVE HUMIDITIES BETWEEN 15 TO 25 PCT WILL STILL OCCUR THOUGH NORTH AND WEST OF THE FOX VALLEY. POTENTIAL IS THERE FOR HUMIDITIES TO FALL LOWER THAN THIS IF TAPPING OCCURS INTO THIS BONE DRY AIR ALOFT. HIGHS MAINLY IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY ISSUED AT 400 AM CDT FRI APR 17 2015 500MB OPEN TROUGH WILL EVOLVE INTO A CLOSED LOW OVER THE WESTERN GREAT LAKES REGION BY EARLY NEXT WEEK. COOL CYCLONIC FLOW WILL CONTINUE FOR THE REMAINDER OF NEXT WEEK AS THE 500MB LOW MEANDERS ACROSS THE GREAT LAKES REGION/EASTERN CANADA. MODELS IN SOMEWHAT BETTER AGREEMENT TONIGHT BRINGING THE BEST CHANCE FOR RAIN SUNDAY INTO SUNDAY NIGHT. WILL CONTINUE A SMALL CHANCE OF SHOWERS AFTER MIDNIGHT ON SATURDAY NIGHT TO ACCOUNT FOR A SLIGHTLY QUICKER ARRIVAL THAT SOME OF THE MODELS ARE DEPICTING. WILL HAVE LIKELY OR LOW END CATEGORICAL CHANCES FOR RAIN ON SUNDAY. HIGH TEMPERATURES TRICKY DEPENDING ON QUICK THE STEADIER RAINS ARRIVE. IF RAIN ARRIVES EARLY IN THE DAY SUNDAY...HIGH TEMPERATURES WILL NEED TO BE LOWERED. COUNTING ON SOME DRY ON BACKSIDE OF THE RETREATING HIGH PRESSURE SYSTEM TO SLOW THE ARRIVAL OF THE RAIN ACROSS EASTERN WISCONSIN. OTHERWISE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE WEEK WITH CHANCES OF RAIN INTO THE MIDDLE OF NEXT WEEK. STILL HAVE A CHANCE OF SNOW LATE AT NIGHT OR EARLY IN THE DAY FOR EACH PERIOD FROM MONDAY NIGHT THROUGH WEDNESDAY. BY THURSDAY...UPPER LOW MAY BE FAR ENOUGH AWAY FOR JUST A SMALL CHANCE OF RAIN ACROSS THE FAR NORTH. PREVIOUS FORECAST TEMPERATURES SEEMED REASONABLE WITH ONLY MINOR CHANGES MADE IN SOME PERIODS. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 604 AM CDT FRI APR 17 2015 VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. SCATTERED TO BROKEN MID-LEVEL CLOUDS WILL DEPART THIS MORNING...WHICH WILL LEAVE CLEAR CONDITIONS THROUGH TONIGHT. A DRY COLD FRONT WILL ARRIVE AFTER MIDNIGHT. WINDS WILL SHIFT TO THE NORTHEAST BEHIND THE FRONT...AND BECOME GUSTY FOR A FEW HOURS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ECKBERG AVIATION.......MPC
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND SATURDAY ISSUED AT 400 AM CDT FRI APR 17 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAK COLD FRONT SLOWLY MOVING TO THE SOUTHEAST OVER FAR NORTHWEST WISCONSIN. AHEAD OF THE FRONT...AREAS OF BROKEN MID-CLOUDS ARE MOVING TO THE EAST OVER CENTRAL AND NORTHERN WISCONSIN. CLEAR SKIES EXIST BEHIND THIS FRONT OVER THE NORTHERN PLAINS. MEANWHILE...SHOWERS AND THUNDERSTORMS ARE OCCURRING OVER THE CENTRAL PLAINS AHEAD OF AN UPPER LOW SPINNING OVER THE 4 CORNERS REGION. FORECAST CONCERNS INCLUDE HIGH TEMPS AND LOW HUMIDITIES FOR SATURDAY. TODAY...THE COLD FRONT WILL SLOW AS IT WEAKENS OVER THE NORTHWEST THIRD OF THE STATE. SCATTERED TO BROKEN MID-LEVEL CLOUD DECK WILL GRADUALLY DISSIPATE THROUGH THE MORNING AS SUBSIDENCE STRENGTHENS OVERHEAD. WILL STILL BE SOME RESIDUAL MOISTURE LEFT AROUND 800MB...HOWEVER...THAT WILL TURN INTO A CU FIELD BY LATE MORNING OVER CENTRAL TO NORTHEAST WISCONSIN. FAR NORTHERN WISCONSIN WILL SEE AN INFLUX OF DRIER AIR DURING THE AFTERNOON...WHICH WILL DROP HUMIDITIES INTO THE 20 TO 25 PCT RANGE. HUMIDITIES SHOULD BE ABOVE CRITICAL CRITERIA ELSEWHERE. RAISED HIGH TEMPS BASED ON 925MB TEMPS ON THE BETTER PERFORMING NAM AND ECMWF...AND MAY NOT BE HIGH ENOUGH. TEMPS TO MAX OUT TO NEAR 70 NORTH TO THE UPPER 70S IN THE WARM SPOTS. TONIGHT...THE WEAKENING FRONT WILL DROP ACROSS CENTRAL AND NORTHEAST WISCONSIN DURING THE EVENING WHILE A SECONDARY AND MORE POTENT FRONT QUICKLY MOVES SOUTH ACROSS NORTHERN AND CENTRAL WISCONSIN AFTER MIDNIGHT. BEHIND THE SECOND FRONT...WINDS WILL SHIFT TO THE NORTHEAST AND COULD GUST FOR A COUPLE HOURS TO 20 OR 25 MPH. TEMPS WILL ALSO COOL OFF QUICKLY BEHIND THE FRONT WITH LOWS FALLING INTO THE MIDDLE 30S NORTH TO THE MIDDLE 40S SOUTH. SATURDAY...CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE CENTRAL GREAT LAKES. THE AIRMASS ASSOCIATED WITH THIS SURFACE HIGH IS EXCEPTIONALLY DRY (NAM 850-700MB RH FALLS TO 2 PCT!). THOUGH HIGH CLOUDS WILL BE ON THE INCREASE DURING THE AFTERNOON AHEAD OF THE CENTRAL ROCKIES UPPER LOW...SHOULD STILL SEE PLENTY OF SUNSHINE ALBEIT WITH COOLER TEMPERATURES. CRITICAL RELATIVE HUMIDITIES BETWEEN 15 TO 25 PCT WILL STILL OCCUR THOUGH NORTH AND WEST OF THE FOX VALLEY. POTENTIAL IS THERE FOR HUMIDITIES TO FALL LOWER THAN THIS IF TAPPING OCCURS INTO THIS BONE DRY AIR ALOFT. HIGHS MAINLY IN THE LOW TO MID 60S AWAY FROM LAKE MICHIGAN. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY ISSUED AT 400 AM CDT FRI APR 17 2015 500MB OPEN TROUGH WILL EVOLVE INTO A CLOSED LOW OVER THE WESTERN GREAT LAKES REGION BY EARLY NEXT WEEK. COOL CYCLONIC FLOW WILL CONTINUE FOR THE REMAINDER OF NEXT WEEK AS THE 500MB LOW MEANDERS ACROSS THE GREAT LAKES REGION/EASTERN CANADA. MODELS IN SOMEWHAT BETTER AGREEMENT TONIGHT BRINGING THE BEST CHANCE FOR RAIN SUNDAY INTO SUNDAY NIGHT. WILL CONTINUE A SMALL CHANCE OF SHOWERS AFTER MIDNIGHT ON SATURDAY NIGHT TO ACCOUNT FOR A SLIGHTLY QUICKER ARRIVAL THAT SOME OF THE MODELS ARE DEPICTING. WILL HAVE LIKELY OR LOW END CATEGORICAL CHANCES FOR RAIN ON SUNDAY. HIGH TEMPERATURES TRICKY DEPENDING ON QUICK THE STEADIER RAINS ARRIVE. IF RAIN ARRIVES EARLY IN THE DAY SUNDAY...HIGH TEMPERATURES WILL NEED TO BE LOWERED. COUNTING ON SOME DRY ON BACKSIDE OF THE RETREATING HIGH PRESSURE SYSTEM TO SLOW THE ARRIVAL OF THE RAIN ACROSS EASTERN WISCONSIN. OTHERWISE...BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF THE WEEK WITH CHANCES OF RAIN INTO THE MIDDLE OF NEXT WEEK. STILL HAVE A CHANCE OF SNOW LATE AT NIGHT OR EARLY IN THE DAY FOR EACH PERIOD FROM MONDAY NIGHT THROUGH WEDNESDAY. BY THURSDAY...UPPER LOW MAY BE FAR ENOUGH AWAY FOR JUST A SMALL CHANCE OF RAIN ACROSS THE FAR NORTH. PREVIOUS FORECAST TEMPERATURES SEEMED REASONABLE WITH ONLY MINOR CHANGES MADE IN SOME PERIODS. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1048 PM CDT THU APR 16 2015 VFR CONDITIONS EXPECTED TONIGHT INTO FRIDAY. A FRONTAL BOUNDARY WILL DROP SOUTHEASTWARD OVER THE STATE TONIGHT INTO FRIDAY MORNING. SINCE THE AIR MASS IS DRY...EXPECT A BAND OF MID LEVEL CLOUDS TO BE ASSOCIATED WITH THE FRONT. LIGHT SOUTHWEST WINDS SHIFTING NORTHWEST WILL MARK THE FRONTS PASSAGE. LATER FRIDAY MORNING...DEEP MIXING MAY PRODUCE A WEST WIND OF 5 TO 10 MPH WHILE WINDS TURN NORTHEAST TO EAST ALONG LAKE MICHIGAN FRIDAY AFTERNOON. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ECKBERG AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
945 PM MDT SAT APR 18 2015 .UPDATE... ISSUED AT 945 PM MDT SAT APR 18 2015 THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST TO CANCEL ALL WINTER HEADLINES AT THIS TIME. ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS THE FOG AROUND THROUGH 11PM-12AM. .UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015 TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR THE NEXT HOUR OR SO. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 440 PM MDT SAT APR 18 2015 LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS. THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN THE FORECAST AREA. SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE OVER THE NEXT FEW HOURS. ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY BE NEEDED EVENTUALLY. QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT. ACCUMULATIONS WILL BE MINIMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 250 PM MDT SAT APR 18 2015 MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER EAST DUE TO A PERSISTENT LLVL STRATUS DECK. MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30 PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY SATURDAY MORNING. && .AVIATION...(FOR THE 00Z TAFS THROUGH SUNDAY AFTERNOON) A BAND OF SNOW AND RAIN WILL REMAIN OVER CONVERSE...CARBON...AND ALBANY COUNTIES THIS EVENING...AND THEN WILL RAPIDLY PUSH SOUTHEAST NEAR A COLD FRONT...WHICH WILL PUSH SOUTHWARD TONIGHT. SCATTERED TSTORMS HAVE DEVELOPED NEAR KSNY AND JUST EAST OF KCYS THIS AFTERNOON. THESE TSTORMS WILL GRADUALLY MOVE NORTHWEST THIS AFTERNOON AND THIS EVENING. SMALL HAIL AND BRIEF HEAVY RAINFALL IS EXPECTED. A MORE STABLE AIRMASS WILL PUSH INTO THE REGION ON SUNDAY BEHIND A WEAK COLD FRONT...RESULTING IN LOW PRECIPITATION CHANCES ACROSS MOST OF THE FORECAST AREA. HOWEVER...IT WILL BE WINDY BEHIND THIS FRONT WITH NORTH WINDS BETWEEN 20 TO 30 KNOTS EAST OF THE LARAMIE RANGE. && .FIRE WEATHER... ISSUED AT 250 PM MDT SAT APR 18 2015 SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS. WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT WEEK...MAYBE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER STORM WARNING UNTIL 11 PM MDT THIS EVENING FOR WYZ110-114. WINTER WEATHER ADVISORY UNTIL 11 PM MDT THIS EVENING FOR WYZ103- 105-112-113. NE...NONE. && $$ UPDATE...RJM SHORT TERM...SML LONG TERM...TJT AVIATION...TJT FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1053 PM MDT THU APR 16 2015 .UPDATE... ISSUED AT 539 PM MDT THU APR 16 2015 LATEST RADAR TRENDS SHOWING PRECIP FILLING IN OVER NORTEASTERN COLORADO. LATEST INFRARED IMAGERY SHOWING RAPIDLY COOLING CLOUD TOPS OVER SOUTHEASTERN COLORADO...MOVING DUE NORTH...SO OUR DRY SLOT WE HAVE BEEN LOOKING AT LATE THIS AFTERNOON IS GETTING EDGED EASTWARD. BOTH GFS AND NAM SOUNDINGS SHOWING FAVORABLE TEMPERATURE PROFILES LATE THIS EVENING WITH SURFACE TEMPERATURES FALLING TO BELOW FREEZING DURING THE BEST TIME OF LOW LEVEL MOISTURE CONVERGENCE OVER THE SOUTH LARAMIE RANGE. VERY STRONG ISENTROPIC LIFT OVER EXTREME SOUTHEAST WYOMING THIS EVENING FROM THE 300-310K PRESSURE SURFACES. OPTED TO UPGRADE THE CURRENT WINTERWEATHER ADVISORY WE HAVE GOING FOR CENTRAL LARAMIE COUNTY TO A WINTER STORM WARNING AS WELL AS INCREASING SNOW AMOUNTS ACROSS THE WARNED AREA AS ALL GUIDANCE POINTING TOWARDS OVER AN INCH OF STORM TOTAL QPF WITH THIS EVENT. UPDATES HAVE BEEN SENT. NEXT CONCERN DEALS WITH POSSIBILITY OF UPGRADING ADVISORIES FURTHER NORTH ACROSS THE CENTRAL LARAMIE RANGE AND POSSIBLY PLATTE COUNTY. CURRENT THINKING RIGHT NOW IS THE AXIS OF HEAVIEST PRECIP WILL MOVE INTO THIS AREA TOMORROW AFTERNOON DURING DAYLIGHT HOURS...SO MAYBE THERE WOULD BE A LITTLE MORE MELTING. DECIDED TO LET THE NIGHT CREW TAKE ANOTHER LOOK AT THIS BEFORE ISSUING ANYTHING. && .SHORT TERM...(TONIGHT-SATURDAY NIGHT) ISSUED AT 248 PM MDT THU APR 16 2015 FORECAST PROBLEMS WILL BE TEMPERATURES AND PRECIPITATION AMOUNTS AND WHERE THE HEAVIER SNOWS WILL FALL OVER THE NEXT COUPLE DAYS. UPPER LOW SPINNING OVER THE 4 CORNERS AREA SHOULD BEGIN A SLOW ENE DRIFT ACROSS COLORADO LATER TONIGHT BEFORE LIKELY STALLING AGAIN OVER COLORADO. PERIODIC DISTURBANCES ROTATING AROUND THIS LOW WILL BRING SHOTS OF RAIN AND SNOW TO MOST OF THE CWA THROUGH SATURDAY BEFORE A SHORTWAVE DROPS OUT OF SW CANADA AND PICKS UP THE LOW...MOVING IT EAST INTO KANSAS AND DECREASING PCPN ACROSS THE CWA. HIGHEST SNOWFALL WILL BE OVER THE LARAMIE RANGE AND THE SNOWYS. ONE CONCERN IS CONVECTION CURRENTLY FIRING OVER KANSAS WHICH COULD CUT MOISTURE AVAILABILITY IN THIS AREA AND REDUCE SNOWFALL AMOUNTS. CURRENT WINTER STORM WARNING LOOKS IN GOOD SHAPE REGARDLESS BUT FOR AREAS SUCH AS AROUND CHEYENNE SNOWFALL COULD TURN OUT GREATER THAN CURRENTLY ANTICIPATED...WITH THE GREATEST RISK BEING LATER TONIGHT INTO FRIDAY MORNING. WILL STAY WITH THE WINTER WX ADVY BUT IT WONT TAKE MUCH TO UPGRADE IT. TEMPERATURES TRICKY THROUGH FRIDAY ESPECIALLY ADJACENT TO THE LAR RANGE WHERE EXPECTED WARMING TODAY DID NOT OCCUR DUE TO SOME COLD AIR DAMMING. SFC WINDS LIKELY TO REMAIN NORTH TO NORTHEASTERLY THUS WAA WILL BE LIMITED IF AT ALL IN THIS AREA. THUS EXPECT PCPN TO REMAIN ALL SNOW THUS HAVE UPPED SNOWFALL AMOUNTS THERE. SHOULD SEE IMPROVEMENT FRIDAY AFTERNOON OVER THE HIGH PLAINS WITH THE NEXT EXPECTED LULL. PCPN SHOULD BECOME MORE SHOWERY IN NATURE FRIDAY NIGHT AND SATURDAY WITH SNOW LEVEL RISING SLOWLY AS SOME WARMING OCCURS. .LONG TERM...(SUNDAY-WEDNESDAY) ISSUED AT 248 PM MDT THU APR 16 2015 OUR PROBLEM CHILD UPPER-LOW WILL FINALLY LOOSEN ITS GRIP ON SUN AS A STRONG KICKER SYSTEM DIVES SOUTHEAST ACROSS THE DAKOTAS. THE PATTERN WILL REMAIN UNSETTLED THOUGH AS CYCLONIC MID LEVEL FLOW WILL REMAIN INTACT OVER THE NORTHERN/CENTRAL ROCKIES. EXPECT INSTABILITY SHOWERS TO CONTINUE FOR MOST OF THE CWA LATE IN THE WEEKEND. GFS/ECMWF SHOW H7 TEMPS FALLING TO AROUND -8 TO -10 DEG C ON SUN AM BEHIND A STRONG COLD FROPA...SO EXPECT THE PTYPE TO BE SNOW. THIS SHOULD NOT AMOUNT TO MUCH OUTSIDE OF THE MOUNTAINS THOUGH. MOST MEDIUM RANGE GUIDANCE SHOWS THE COOL/MOIST CYCLONIC FLOW PERSISTING THROUGH THE MIDDLE OF NEXT WEEK...SO EXPECT CONTINUED DAILY CHANCES FOR RAIN/SNOW SHOWERS WITH LITTLE OR NO ACCUMULATIONS. A WARMING TREND SHOULD BEGIN BY WED AS RIDGING FINALLY TRANSLATES EASTWARD...ALLOWING H7 TEMPS TO CLIMB BACK ABOVE FREEZING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1049 PM MDT THU APR 16 2015 HRRR GUIDANCE USED FOR THE 06Z TAFS. IFR.LIFR CONDITIONS INITIALLY CONFINED TO KLAR AND KCYS WITH WRAP AROUND MOISTURE AND SNOW. LATEST IR IMAGERY SHOWS COOLING CLOUD TOPS THAT INDICATES MOE WIDESPREAD PRECIP LATER THIS MORNING. HRRR SHOWS IFR/LIFR SPREADING EAST INTO THE SOUTHERN NEBRASKA PANHANDLE DURING THE 09-10Z TIMEFRAME AND CONTINUING THROUGH THE DAY FRIDAY. COULD PERSIST THROUGH FRIDAY NIGHT. && .FIRE WEATHER... ISSUED AT 248 PM MDT THU APR 16 2015 MINIMAL CONCERNS SEEN THROUGH THE WEEKEND WITH GENEROUS RAIN AN/OR SNOWS FALLING OVER MUCH OF THE AREA. TEMPERATURES WILL BE COOL TO MILD WITH WEATHER CONDITIONS NON-CRITICAL. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...WINTER STORM WARNING UNTIL NOON MDT FRIDAY FOR WYZ114>118. WINTER WEATHER ADVISORY UNTIL NOON MDT FRIDAY FOR WYZ103-105-106- 110-112. NE...NONE. && $$ UPDATE...GCC SHORT TERM...RE LONG TERM...CLH AVIATION...GCC FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1252 AM MDT SUN APR 19 2015 .UPDATE... ISSUED AT 1250 AM MDT SUN APR 19 2015 UPDATED TO REMOVE EXPIRED WINTER WEATHER HEADLINES. SIGNIFICANT SNOWFALL HAS ENDED IN THE NORTHERN AND CENTRAL MTS OF CO AND ONLY LIGHT ADDITIONAL ACCUMULATIONS AREA EXPECTED. UPDATE ISSUED AT 744 PM MDT SAT APR 18 2015 UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG AS WELL. && .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 325 PM MDT SAT APR 18 2015 THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING. CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT. BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE. TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO 10 DEGREES BELOW NORMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM MDT SAT APR 18 2015 UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY. TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT. GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1040 PM MDT SAT APR 18 2015 A HIGH LATITUDE SYSTEM DIVING INTO THE NORTHERN PLAINS WILL BE KICKING THIS STORM SYSTEM THAT HAS BEEN PARKED OVER COLORADO THE PAST SEVERAL DAYS. THIS WILL ALLOW PRECIPITATION COVERAGE TO TREND DOWNWARD OVER MOST OF WESTERN COLORADO AND EASTERN UTAH. THE HIGH DIVIDE MOUNTAINS WILL THE MOST LIKELY AREA TO KEEP COLLECTING LIGHT SNOW OVERNIGHT AND BE UNDER OBSCURATION. THE BIG CHALLENGE INTO MID MORNING SUNDAY WILL BE LOW CLOUDS AND FOG DUE TO A MOIST NEAR SURFACE LAYER FROM RECENT PRECIPITATION. THERE IS ALREADY A HINT OF THIS AT KRIL...KASE AND KMTJ LATE THIS EVENING AS CLOUD COVER ALOFT HAS THINNED. ANTICIPATE THIS WILL BECOME MORE OF A WIDESPREAD PROBLEM THROUGH THE NIGHT BRINGING IFR/LIFR TO MANY VALLEYS INCLUDING THE COLORADO TAF SITES. IMPROVEMENT SHOULD BE QUICKER SUNDAY MORNING WITH MORE SUNSHINE AVAILABLE TO BURN OFF THE LOW LEVEL MOISTURE. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...CC SHORT TERM...TGR LONG TERM...JAD AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1040 PM MDT SAT APR 18 2015 .UPDATE... ISSUED AT 744 PM MDT SAT APR 18 2015 UPPER LOW CONTINUES TO ROTATE IN PLACE OVER THE EASTERN PLAINS THIS EVENING. WRAP AROUND MOISTURE KEEPING SNOW GOING IN THE HIGH COUNTRY...A MIXTURE ACROSS THE MESA AND PLATEAU REGION AND THUNDERSTORMS ACROSS EASTERN UTAH. STEEP LAPSE RATES DUE TO HEATING OUTSIDE OF THE THICKER CLOUD SHIELD IS AIDING THE WEAK WAVE DROPPING THROUGH EASTERN UTAH. STORMS STARTED OUT QUITE ROBUST WEST OF THE COLORADO RIVER...BUT AS THEY TRAVEL SOUTHEAST ACROSS THE INSTABILITY GRADIENT...THEY WEAKEN OVER OUR CWA. WILL LOSS OF HEATING EXPECT THE COVERAGE TO SLOWLY WANE OVER THE NEXT HOUR OR SO. WILL BE WATCHING THE AFFECT OF NIGHTFALL ON EASTERN PASSES AS MELTING HAS KEPT ROADS IN DECENT SHAPE. MAY KEEP SOME OF THE HEADLINES ALONG DIVIDE IF NECESSARY PAST MIDNIGHT. LASTLY DEW POINTS DID CREEP UP A BIT THIS AFTERNOON INTO THE 40S OVER THE WESTERN VALLEYS. WILL BE MONITORING THE THREAT OF DENSE FOG AS WELL. && .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 325 PM MDT SAT APR 18 2015 THE LOW PRESSURE RESPONSIBLE FOR THE MUCH NEEDED PRECIP OVER THE LAST FEW DAYS IS NOW LOCATED OVER THE FRONT PLAINS WHILE CYCLONIC FLOW CONTINUES TO PUMP IN MOISTURE FROM THE NORTH TO SOUTH. THIS FLOW STARTS IN NERN WY AND THE PLUME REACHES AS FAR SOUTH AS THE SAN JUANS. SNOW AND RAIN HAS FALLEN MUCH OF THE DAY UNDER THIS PLUME OF MOISTURE AND WILL CONTINUE TO DO SO THROUGH THIS EVENING. CURRENT WINTER HIGHLIGHTS LOOK GOOD SO NO CHANGES THERE. AN UPPER LEVEL DISTURBANCE OVER SRN CANADA IS TRAILING A TROUGH THAT IS CAUSING THE AREA OF LOW PRESSURE TO KEEP MOVING EWRD. THE REASON THIS IS HAPPENING SO SLOWLY IS THE LACK OF ANY STRONG JET FEATURES TO REALLY GET THIS SYSTEM MOVING. EVEN SO...THE CLOUD SHIELD/PLUME WILL BRING MORE PRECIP TO THE AREA AS THE ATTENDANT LOW PRESSURE MEANDERS EAST. BY MIDNIGHT...PRECIP WILL FAVOR THE NRN AND CENTRAL MTNS ALONG WITH THE FLATTOPS DUE TO THEIR FAVORABLE LOCATION SO ADDITIONAL ACCUMULATIONS STILL POSSIBLE UP THERE. THE REST OF THE CWA MAY SEE AN ODD SHOWER OR TWO BUT NOTHING TOO SIGNIFICANT. BY SUNDAY...THE CANADIAN LOW WILL BE JUST TO THE NORTH OF MINNESOTA WHILE HIGH PRESSURE BUILDS INTO THE PACNW. THIS WILL CAUSE OUR CWA TO BE SANDWICHED BETWEEN THESE TWO FEATURES. WEAK PIECES OF ENERGY WILL DROP DOWN FROM THE NW POSSIBLY CAUSING SOME PRECIP FOR THE CWA. THE GFS HIGHLIGHTING TWO DISTINCT WAVES...ONE SUNDAY EVENING AND ANOTHER MONDAY MORNING. THE NAM12 ONLY SHOWING SOME SPOTTY SHOWERS AT BEST WITH SOME CONVECTION THROWN IN. THE HRRR AND RAP SHOWING MUCH LESS IN THE WAY OF PRECIP. THIS ALL MEANS UNSETTLED WX WILL CONTINUE BUT WITH MUCH MORE DEFINITIVE BREAKS BETWEEN DISTURBANCES. FORECAST BRINGS MOSTLY BENIGN WEATHER SUNDAY WITH INCREASING CHANCES FOR PRECIP FROM MIDAFTERNOON ONWARDS...MAINLY FAVORING THE CONTINENTAL DIVIDE. TEMPS WILL WARM UP CONSIDERABLY TOMORROW THOUGH STILL REMAIN 5 TO 10 DEGREES BELOW NORMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM MDT SAT APR 18 2015 UNSETTLED NW FLOW IS EXPECTED MONDAY AND TUESDAY. AN EMBEDDED WAVE SHOULD FOCUS THE BEST CHANCE OF SHOWERS OVER THE NORTHERN AND CENTRAL MOUNTAINS MONDAY AFTERNOON AND EVENING. DAYTIME INSTABILITY WILL KEEP ISOLATED TO SCATTERED SHOWERS OVER THE MTNS ON TUESDAY. TEMPORARY RIDGING DEVELOPS OVER THE AREA BY MIDWEEK AS A TROUGH FORMS ALONG THE WEST COAST...WITH AN UPPER LOW OVER SRN CA BY THU MORNING. ENOUGH RESIDUAL MOISTURE LINGERS FOR A FEW AFTERNOON SHOWERS OR THUNDERSTORMS. FLOW ALOFT BECOMES SOUTHWEST...AND THE SRN CA LIFTS ACROSS THE FOUR CORNERS/DESERT SOUTHWEST THU NIGHT AND FRI MORNING. TIMING AND TRACK A BIT DIFFERENT BETWEEN MODELS BUT STILL LOOKING LIKE A BETTER CHANCE OF PRECIPITATION WITH SOME THUNDERSTORMS LATE NEXT WEEK. BOOSTED POPS FOR THU AFTERNOON THROUGH FRI OVER THE BLENDED FORECAST GUIDANCE AS A RESULT. GFS AND ECMWF SOLUTIONS CONTINUE TO DIVERGE ON SATURDAY. ECMWF MORE AMPLIFIED AS IT DIGS A PAC NW TROUGH TO THE SRN GREAT BASIN BY SATURDAY...RESULTING IN DOWNSTREAM RIDGING AND SW FLOW OVER OUR AREA. GFS DROPS SOME ENERGY FROM THE PAC NW TROUGH DOWN THE WEST COAST BUT SENDS MORE OF IT ACROSS THE NRN ROCKIES WITH WESTERLY FLOW ACROSS UT/CO. WILL FOLLOW THE BLENDED GUIDANCE FOR SAT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1040 PM MDT SAT APR 18 2015 A HIGH LATITUDE SYSTEM DIVING INTO THE NORTHERN PLAINS WILL BE KICKING THIS STORM SYSTEM THAT HAS BEEN PARKED OVER COLORADO THE PAST SEVERAL DAYS. THIS WILL ALLOW PRECIPITATION COVERAGE TO TREND DOWNWARD OVER MOST OF WESTERN COLORADO AND EASTERN UTAH. THE HIGH DIVIDE MOUNTAINS WILL THE MOST LIKELY AREA TO KEEP COLLECTING LIGHT SNOW OVERNIGHT AND BE UNDER OBSCURATION. THE BIG CHALLENGE INTO MID MORNING SUNDAY WILL BE LOW CLOUDS AND FOG DUE TO A MOIST NEAR SURFACE LAYER FROM RECENT PRECIPITATION. THERE IS ALREADY A HINT OF THIS AT KRIL...KASE AND KMTJ LATE THIS EVENING AS CLOUD COVER ALOFT HAS THINNED. ANTICIPATE THIS WILL BECOME MORE OF A WIDESPREAD PROBLEM THROUGH THE NIGHT BRINGING IFR/LIFR TO MANY VALLEYS INCLUDING THE COLORADO TAF SITES. IMPROVEMENT SHOULD BE QUICKER SUNDAY MORNING WITH MORE SUNSHINE AVAILABLE TO BURN OFF THE LOW LEVEL MOISTURE. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER STORM WARNING UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-010- 012-017-018. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ003- 004-013. UT...NONE. && $$ UPDATE...15 SHORT TERM...TGR LONG TERM...JAD AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 AM CDT SUN APR 19 2015 .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * EAST WINDS ARND 6 TO 10 KT...OCCASIONAL GUSTS TO 17KT. * WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON. * RAIN OVERSPREAD TAF SITES LATE THIS AFTN THRU TONIGHT. * POSSIBLE LOW END MVFR CIGS OR PATCHY IFR CIGS DEVELOPING. BEACHLER //DISCUSSION...UPDATED 06Z... WITH THE DEPARTING HIGH PRESSURE TO THE EAST...MID-LVL MOISTURE WAS SLOWLY LIFTING NORTH ACROSS THE NORTHERN IL/NORTHWEST IN AIRFIELDS. THIS HAS ALLOWED A CIRRUS CLOUD DECK TO THICKEN...AND ADDITIONAL MOISTURE IS EXPECTED TO LIFT NORTHEAST AS A LOW PRESSURE SYSTEM NEARS THE REGION LATER TONIGHT INTO EARLY MON. GUIDANCE HAS BEEN SLOWLY TRENDING LATER WITH THE ARRIVAL OF PRECIP UNTIL AFT 18Z...AND MAY NOT BE CLOSER TO 23Z. WILL CONTINUE TO MENTION VCSH BUT PUSH IT TO 20Z...THEN EXPECT THE COVERAGE TO INCREASE IN PRECIP CLOSER TO 23Z. WITH THE STEADILY THICKEN AND LOWER CLOUDS...THE CHALLENGE IS ALSO ON WIND SPEEDS. IT IS STILL POSSIBLE GUSTS WILL NEED TO BE PUT BACK INTO THE TAF...ALTHOUGH WITH THE ABUNDANT CLOUD COVER...IT IS QUESTIONABLE HOW FREQUENT GUSTS WILL OCCUR AT THE TAF SITES. SO HAVE REMOVED THE MENTION AT THIS TIME AND JUST INCREASED THE SUSTAINED WINDS. THEN AT SOME POINT LATE THIS EVENING CIGS ARE EXPECTED TO QUICKLY DIP TO MVFR AND POSSIBLY TO IFR CONDS. PRECIP COVERAGE WILL BEGIN TO DIMINISH EARLY MON...AND MAY TREND TOWARDS PATCHY DRIZZLE WHICH MAY ALSO FURTHER LOWER CIGS AND VSBYS EARLY MON MORNING. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE IN WIND DIR/SPEED AFT 18Z. * MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE. * HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT 21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...CHANCE OF SHRA/MVFR. GUSTY WEST-NORTHWESTERLY WINDS. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. KJB && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
344 AM CDT SUN APR 19 2015 .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * EAST WINDS ARND 6 TO 10 KT...OCCASIONAL GUSTS TO 17KT. * WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON. * RAIN OVERSPREAD TAF SITES LATE THIS AFTN THRU TONIGHT. * POSSIBLE LOW END MVFR CIGS OR PATCHY IFR CIGS DEVELOPING. BEACHLER //DISCUSSION...UPDATED 06Z... WITH THE DEPARTING HIGH PRESSURE TO THE EAST...MID-LVL MOISTURE WAS SLOWLY LIFTING NORTH ACROSS THE NORTHERN IL/NORTHWEST IN AIRFIELDS. THIS HAS ALLOWED A CIRRUS CLOUD DECK TO THICKEN...AND ADDITIONAL MOISTURE IS EXPECTED TO LIFT NORTHEAST AS A LOW PRESSURE SYSTEM NEARS THE REGION LATER TONIGHT INTO EARLY MON. GUIDANCE HAS BEEN SLOWLY TRENDING LATER WITH THE ARRIVAL OF PRECIP UNTIL AFT 18Z...AND MAY NOT BE CLOSER TO 23Z. WILL CONTINUE TO MENTION VCSH BUT PUSH IT TO 20Z...THEN EXPECT THE COVERAGE TO INCREASE IN PRECIP CLOSER TO 23Z. WITH THE STEADILY THICKEN AND LOWER CLOUDS...THE CHALLENGE IS ALSO ON WIND SPEEDS. IT IS STILL POSSIBLE GUSTS WILL NEED TO BE PUT BACK INTO THE TAF...ALTHOUGH WITH THE ABUNDANT CLOUD COVER...IT IS QUESTIONABLE HOW FREQUENT GUSTS WILL OCCUR AT THE TAF SITES. SO HAVE REMOVED THE MENTION AT THIS TIME AND JUST INCREASED THE SUSTAINED WINDS. THEN AT SOME POINT LATE THIS EVENING CIGS ARE EXPECTED TO QUICKLY DIP TO MVFR AND POSSIBLY TO IFR CONDS. PRECIP COVERAGE WILL BEGIN TO DIMINISH EARLY MON...AND MAY TREND TOWARDS PATCHY DRIZZLE WHICH MAY ALSO FURTHER LOWER CIGS AND VSBYS EARLY MON MORNING. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE IN WIND DIR/SPEED AFT 18Z. * MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE. * HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT 21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...CHANCE OF SHRA/MVFR. GUSTY WEST-NORTHWESTERLY WINDS. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. KJB && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
328 AM CDT SUN APR 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 328 AM CDT SUN APR 19 2015 LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER, SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING, THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO ARRIVE. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 328 AM CDT SUN APR 19 2015 LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS. MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING. SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE 500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE UPPER 30S AND LOWER 40S. 00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY: HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY. ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY, WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1145 PM CDT SAT APR 18 2015 VFR CONDITIONS CONTINUE ACROSS CENTRAL IL TAF SITES THIS EVENING AS A COMPLEX PATTERN OF A LARGE SCALE CENTRAL U.S. TROUGH WITH MULTIPLE EMBEDDED DISTURBANCES DEVELOPS. MAINLY VFR CONDITIONS EXPECTED UNTIL AROUND 12Z WHEN THE FIRST EMBEDDED DISTURBANCE LIFTS NORTHEASTWARD INTO SE ILLINOIS. EXPECT INCREASING PRECIPITATION AT SOUTHERN TERMINALS KSPI-KDEC AROUND 10Z SPREADING NORTH TO KPIA-KBMI-KCMI AROUND 12Z. BY 14-16Z...PREDOMINANT RAIN WITH MVFR CIGS/VSBYS LIKELY AND INCLUDED IN TAFS. ISOLATED THUNDERSTORMS POSSIBLE AS WELL...BUT LIKELIHOOD/TIMING NOT HIGH ENOUGH FOR EXPLICIT MENTION THIS FAR OUT. BRIEFLY IMPROVING CONDITIONS LATE AFTERNOON EARLY EVENING AS FIRST DISTURBANCE MOVES OUT OF CENTRAL IL...BUT TRAILING WAVE/COLD FRONT EXPECTED TO INITIATE ADDITIONAL SHOWERS/THUNDERSTORMS TOWARD 06Z. WITH A NARROW WINDOW OF UNCERTAIN IMPROVEMENT...KEPT MVFR CIGS/VSBYS THROUGH 06Z. WINDS E-NE5-10 KTS THROUGH 15Z BECOMING VARIABLE- NNW DURING AFTERNOON AS LOW LIFTS TO THE NE OF CENTRAL IL AREA. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...BARNES AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1205 AM CDT SUN APR 19 2015 .DISCUSSION... FOR THE 06Z TAF PACKAGE. && .AVIATION... AS ANTICIPATED...VISIBILITY RESTRICTIONS HAVE BEGUN TO DEVELOP ACROSS THE AREA...AND CONVECTIVE COMPLEX APPROACHING FROM THE NORTHWEST IS STARTING TO DECAY. TIMED THE REMNANTS OF THIS FEATURE INTO KBPT...KLCH...AND KAEX AS JUST A BRIEF PERIOD OF INCREASED WINDS AND LIGHT RAIN. NO EFFECTS CARRIED AT THE ACADIANA TERMINALS. EXPECT THAT THE RESULTANT MIXING WILL IMPROVE THE VISIBILITY...AT LEAST TEMPORARILY...BUT DID SHOW THE FOG RE- DEVELOPING A COUPLE HOURS LATER. VFR TO PREVAIL TOMORROW ONCE THE FOG ERODES. 13 && .PREV DISCUSSION... /ISSUED 925 PM CDT SAT APR 18 2015/ DISCUSSION... MAIN WX CONCERN IS THE MCS OVER C AND N TX...MOVING E. RADAR STILL SHOWS FAIRLY SOLID SQUALL LINE BETWEEN WHILE SOME WEAKENING IS EXPECTED TO CONTINUE...LATEST NAM12 & HRRR SUGGEST IT CONTINUING E THE NEXT SEVERAL HOURS...AFFECTING INLAND SE TX/C LA BETWEEN 06-09Z. THUS...HAVE INCREASED THE POPS AND QPF ACROSS THESE AREAS FOR THE EVENING UPDATE. FOR THE REMAINDER OF THE AREA...20% CONTINUES FOR ANY ISO SHRA/TSRA AHEAD OF THIS SYSTEM. DML PREV DISCUSSION... /ISSUED 734 PM CDT SAT APR 18 2015/ DISCUSSION... FOR THE 00Z TAF PACKAGE. AVIATION... MAINLY ISOLATED TO SCATTERED SHOWERS ACROSS PARTS OF EAST AND SOUTH CENTRAL LOUISIANA EARLY THIS EVENING. LATEST HRRR DEPICTS CONVECTIVE COMPLEX OVER CENTRAL TEXAS REACHING PERHAPS AS FAR AS JUST EAST OF THE SABINE RIVER SOMETIME AFTER MIDNIGHT BEFORE DISSIPATING. WILL CONTINUE TO MONITOR RADAR/MODEL TRENDS THROUGH THE EVENING. OTHERWISE...A MIX OF MVFR/VFR CIGS ACROSS THE AREA IS EXPECTED TO LOWER INTO MVFR/IFR AS LIGHT FOG AND/OR LOWER CIGS DEVELOP DURING THE OVERNIGHT HOURS. IMPROVEMENT TO VFR IS EXPECTED ON SUNDAY AS DRIER AIR MOVES IN FROM THE WEST. 13 PREV DISCUSSION... /ISSUED 421 PM CDT SAT APR 18 2015/ SYNOPSIS... LATEST UA ANALYSIS AND WV IMAGERY SHOWS SLOW-MOVING UPR LOW OVER ERN COLORADO...WITH MOIST SWLY FLOW CONTINUING TO STREAM OVER THE REGION. ONE IMPULSE ASSOCIATED WITH THIS SYSTEM WAS MOVING ACRS SRN TX INTO THE WRN GULF...WITH A SECOND IMPULSE CROSSING WRN TX. THESE TWO SYSTEMS WERE TRIGGERING STORMS ACRS THE NW/CNTL GULF COAST AS WELL AS ACRS WRN TX. OVER THE IMMEDIATE CWA...ACTIVITY HAS REMAINED FAIRLY SCTD...WITH A SWATH OF LT/MODT RAIN OVER THE COASTAL WATERS...AND SCT SHRA/TSRA ACRS CNTL/WRN LA. DISCUSSION... OVERNIGHT CONVECTIVE COMPLEX ALLOWED THE AIRMASS TO STABILIZE TODAY...AND ONGOING CONVECTION OVER THE GULF HAS LIMITED INFLOW. THIS COMBINATION HAS REDUCED THE POTENTIAL FOR HEAVY RAIN AND WIDESPREAD ACTIVITY TODAY AND LIKELY INTO TONIGHT. LOOKING AT A COMBINATION OF RECENT HRRR RUNS AS WELL AS RAP/NAM GUIDANCE SHOWS A DECREASING TREND DURING THE EVENING AND OVERNIGHT. ACTIVITY ALONG THE TX COAST IS EXPECTED TO TREK E/NE BUT GRADUALLY WEAKEN AS IT APPROACHES OUR COASTAL WATERS ZONES. LIKEWISE...THE STORMS ACRS WRN TX WILL MOVE EAST THIS EVENING...BUT ALSO WEAKEN AS THEY REACH THE AREA LATER TONIGHT. QPF VALUES ARE EXPECTED TO REMAIN BELOW AN INCH THROUGH SUNDAY...AND WITH THIS IN MIND...HAVE GONE AHEAD AND CANCELLED THE FLASH FLOOD WATCH. DRIER MID LVL AIR WILL BEGIN TO PUSH EAST OVER THE AREA ON SUNDAY...HELPING TO BRING A REPREIVE FROM THE RAINY PATTERN. HOWEVER...ENOUGH MOISTURE WILL LINGER TO ALLOW FOR AT LEAST A SLT CHC FOR A FEW SHOWERS OR TSTMS. BY SUNDAY NIGHT...A COOL FRONT WILL MOVE THROUGH THE REGION. ENOUGH CONVERGENCE AND LIFT ARE EXPECTED ALONG THE FRONTAL BOUNDARY TO PRODUCE A SCT BAND OF SHOWERS AND TSTMS AS IT CROSSES THE AREA. SPC DOES HAVE THE AREA OUTLINED IN A SLT RISK FOR SUNDAY/SUNDAY NIGHT AS INSTABILITY LOOKS TO INCREASE AHEAD OF THE BOUNDARY. THUS AN ISOLATED STRONG TO SEVERE STORM CANNOT BE RULED OUT ESPECIALLY ACRS THE NRN TIER OF COUNTIES AND PARISHES. DRY WEATHER FINALLY RETURNS ON MONDAY AND SHOULD CONTINUE INTO TUESDAY AS HIGH PRES BUILDS INTO THE AREA. SMALL RAIN CHCS WILL RETURN BY MIDWEEK WITH CHCS INCREASING TOWARD THE LATTER PART OF THE WEEK. ZONAL FLOW WILL PREVAIL THROUGH THE WEEK AND LIFT ASSOCIATED WITH EMBEDDED DISTURBANCES WILL KEEP AT LEAST CHC POPS OVER THE AREA THURSDAY AND FRIDAY. MARINE... LT TO MDT SWLY FLOW WILL CONTINUE THROUGH SUNDAY WITH SHOWERS AND TSTMS GRADUALLY DIMINISHING. A COOL FRONT WILL CROSS THE COASTAL WATERS LATE SUNDAY NIGHT...WITH MODT OFFSHORE FLOW DEVELOPING FOR MONDAY. EXERCISE CAUTION CONDITIONS COULD BE POSSIBLE AT TIMES MONDAY INTO TUESDAY. WINDS WILL GRADUALLY VEER ELY TUESDAY...THEN SELY BY WEDNESDAY AS SFC HIGH PRES MOVES EAST. && .PRELIMINARY POINT TEMPS/POPS... AEX 63 83 60 76 / 30 30 30 10 LCH 64 82 63 79 / 20 20 20 10 LFT 65 84 64 79 / 30 20 20 10 BPT 64 82 63 79 / 20 20 20 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS DULUTH MN
342 AM CDT SUN APR 19 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT. AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA. THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY WINDS. THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST AREA LATE THIS MORNING. THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN MANITOBA. LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA. LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING. MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS. SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO JUST NORTH OF KOOCHICHING COUNTY. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES... FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY. THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW. STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S ON THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 101 AM CDT SUN APR 19 2015 AN AREA OF LOW PRESSURE WILL SPREAD GRADUALLY LOWERING CLOUDS AND RAINFALL INTO THE AREA FROM THE SOUTHWEST THROUGH 10Z...WITH CEILINGS SLOWLY LOWERING TO IFR WITH VISIBILITIES TO MVFR IN LIGHT RAIN. THIS WILL CONTINUE THROUGH APPROXIMATELY 18Z BEFORE SLOWLY DIMINISHING AGAIN FROM SOUTHWEST TO NORTHEAST. CEILINGS EXPECTED TO REMAIN MVFR-IFR UNTIL AFTER LOW PASSAGE AND WINDS TURN TO NORTHWEST...ALLOWING CEILINGS AND VISIBILITIES TO GRADUALLY RETURN TO MVFR...THEN VFR BY 02Z THIS EVENING. && .PRELIMINARY POINT TEMPS/POPS... DLH 49 36 42 30 / 90 40 60 50 INL 49 32 40 27 / 100 50 70 60 BRD 55 36 42 30 / 90 20 60 40 HYR 56 37 44 31 / 90 60 50 50 ASX 56 38 45 32 / 80 60 50 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ142>147. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...DAP AVIATION...DAP
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
1201 AM CDT Sun Apr 19 2015 ...Updated Aviation Section... .UPDATE... Issued at 703 PM CDT SAT APR 18 2015 Forecast will be updated shortly to account for short term trends from satellite/radar as well as to account for expected convective trends heading into the overnight hours. Over the past few hours, we have seen clearing across western portions of the area. This clearing will likely be short lived as mid/high level clouds increase from the west from convective exhaust. That said, this area did see a soaking rain this morning and dewpoints remain relatively high compared to expected lows. As a result, will include a mention of patchy fog and keep an eye on localized dense fog potential in places where skies can remain clear for a longer period of time. In addition, PoPs have been updated for the next 12 or so hours. The western half of the area will likely see little in the way of rain chances this evening. Chances over the eastern half look to remain in the solid chance range giving on again/off again showers and isolated thunder. HRRR and other short range models continue to indicate rain chances increasing across south central Missouri and the eastern Ozarks from late this evening into the overnight hours. In addition, remnant convection from KS/OK complexes will enter from the west, with rain chances steadily increasing across extreme southeastern Kansas and western Missouri. Interestingly, the Highway 65 corridor will likely be between these two areas of activity and PoPs are lowest in this area for tonight. Taking a peak at tomorrow`s severe weather potential. There remains some question as to just how much instability we will be able to generate as decaying convection continues to spread in from the west during the morning hours. The main upper trough will not arrive until later in the day, bringing and increase in deep layer shear. However, models struggle to bring much more that 500-1000 J/kg of most unstable CAPE into the southern half of the area. By far the better chances for severe convection will be to our south and southeast. Obviously this is close enough to keep a close eye on trends and we will see what the 00z suite of models have in store for the area. && .SHORT TERM...(This Evening through Sunday Night) Issued at 315 PM CDT SAT APR 18 2015 The coverage of showers and thunderstorms continued to decrease into the afternoon. However a band of scattered showers and storms persisted along a 925-850 MB convergence axis that stretched north to south east of the Highway 65 corridor and in advance of a mid level vorticity lobe lifting northeast across the area. Expect convection through early evening to be focused along and ahead of these features across south central Missouri. This 925-850 MB convergence axis may become the focus for additional development later tonight across the eastern Ozarks as another vorticity lobe lifts northeast toward southeastern Missouri. Coverage of precipitation will remain more isolated elsewhere much of tonight. However there may be increase in convection from the west into southeastern Kansas into far southwest late tonight as convection across the Plains shifts eastward. The closed upper level low now over eastern Colorado will open up and track eastward toward Missouri on Sunday. Expect the coverage of convection to increase Sunday as synoptic scale lift increases with the aide of an increasingly diffluent upper flow and the approach of vorticity maxima. Deep layer shear will increase Sunday as the mid level flow strengthens and lapse rates steepen as temperatures aloft cool in response to the approaching upper level trough. The question is the extent of instability that will develop. The potential for ongoing convection and cloud cover may limit surface heating and resulting instability. However if sufficient instability can be realized then ingredients would be in place for at least a few severe storms. At this time the greatest potential for strong to severe storms will be across far southern Missouri or generally along and south of Interstate 44. The risk for severe weather could decrease or increase depending on the amount of destabilization. The primary risks with any severe storms that can develop would damaging winds and large hail. With some areas already receiving moderate to heavy rainfall the past couple of days...the risk for localized flooding will have to be monitored particularly across far southwestern Missouri. Showers and some thunder will linger into Sunday night as the upper level trough and associated cold front track across the area. .LONG TERM...(Monday through Saturday) Issued at 315 PM CDT SAT APR 18 2015 Much cooler weather will prevail heading into early next week as an upper level trough digs into the Great Lakes and maintains a northwesterly flow aloft across the region. This cooler weather will persist most of next week. Weather conditions could also be rather unsettled as disturbances slide southeastward around the periphery of the upper trough. This will bring intervals clouds and the possibility of showers and thunderstorms at times mid through late week. However this activity is expected to be spotty in nature. Temperatures could fall into the upper 30s Monday night. Frost is not expected at this time but this potential should be monitored. && .AVIATION...(For the 06Z TAFS through 06Z Sunday Night) Issued at 1201 AM CDT SUN APR 19 2015 Challenging forecast for area aerodromes as convection will fester around the region the rest of tonight, and regenerate Sunday afternoon. Decaying bands of showers/storms will attempt to enter from the west in the coming hours, however a lack of instability will likely result in this activity losing its punch and gradually dissipating as it moves through the JLN aerodrome. Earlier clearing at SGF/BBG is being replaced by mid/high level clouds. There is patchy ground fog around, but this may not become too widespread. Bouts of MVFR visibility are expected, with an outside chance of IFR at BBG. Main storm system will move into area Sunday afternoon/evening. Another round of showers/storms will be associated with this system, which will begin to exit to the east by the end of the TAF cycle. Winds will be light into the daylight hours of Sunday morning, becoming southwesterly during the day and shift to the northwest heading into the evening. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ UPDATE...Gagan SHORT TERM...Foster LONG TERM...Foster AVIATION...Gagan
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
314 AM CDT SUN APR 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT SUN APR 19 2015 THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE PANHANDLE. THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL WOULD BE EXPECTED. HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN THE AFTERNOON WITH THE COLD AIR ALOFT. TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA. GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER 30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER LOWS ARE EXPECTED. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 313 AM CDT SUN APR 19 2015 MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND. BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM CDT SAT APR 18 2015 THE THUNDERSTORMS IN CENTRAL NEBRASKA ARE WEAKENING. LATER TONIGHT...AS THE UPPER LOW MAKES ITS WAY ONTO THE PLAINS... SCATTERED SHOWERS WILL COALESCE INTO WIDESPREAD RAIN AFTER 06Z SOUTH OF AN ONL-MHN-OGA LINE. THEN...AS A FRONT COME THROUGH...RAIN WILL END FROM THE NORTH IN CENTRAL NEBRASKA BY 11Z AND IN SOUTH CENTRAL AND SOUTHWEST NEBRASKA EARLY AFTERNOON. THE RAIN IS EXPECTED TO END BBW-LBF-IML AROUND 13Z. AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN INCREASE TO 14-18G24-30KT BY 14Z && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1154 PM CDT SAT APR 18 2015 .SYNOPSIS... ISSUED AT 255 PM CDT SAT APR 18 2015 ANALYSIS OF THE 19Z MSL DATA SHOWED LOW PRESSURE CENTERED IN WESTERN KANSAS WITH A WARM FRONT ACROSS NORTHERN KANSAS...A COLD FRONT INTO THE OKLAHOMA/TEXAS PANHANDLE AND AN INVERTED TROUGH FROM SOUTHWEST TO NORTH CENTRAL NEBRASKA. IN THE UPPER LEVELS...THE WATER VAPOR IMAGERY SHOWED A CLOSED CYCLONIC CIRCULATION LOCATED IN EASTERN COLORADO. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 255 PM CDT SAT APR 18 2015 THE CENTER OF STRONG CUT OFF LOW /H500 MB TEMP -25C/ IS NEAR AKRON COLORADO THIS AFTERNOON. HIGH RES MODELS INSIST THAT CONVECTION...AIDED BY A SIGNIFICANT PV ANOMALY ROTATING NORTHEAST INTO WESTERN KANSAS AROUND THE LOW CENTER...WILL DEVELOP ONCE AGAIN ACROSS NORTHWEST KANSAS AND SOUTHWEST NEBRASKA LATE THIS AFTERNOON AND THIS EVENING. THE ACTIVITY WILL GROW UPSCALE MUCH LIKE LAST NIGHT AS IT MOVES NORTH/NORTHEAST INTO THE REST OF WESTERN...CENTRAL AND NORTH CENTRAL NEBRASKA TONIGHT. AS FAR AS SEVERE POTENTIAL...GOOD SURFACE HEATING UNDERWAY ATTM ACROSS SOUTHWEST NEBRASKA AND NORTHWEST KANSAS. EXPECTING MUCAPE ON THE ORDER OF 1500 J/KG BY LATE AFTERNOON INTO THE EVENING HOURS. ONE WEAKNESS ARE THE WIND FIELDS ARE FAIRLY LIGHT...AND NOT A A LOT OF VEERING WITH HEIGHT. NEVERTHELESS WITH THE STEEP LOW AND MID LEVEL LAPSE RATES...WILL SEE SOME VIGOROUS UPDRAFTS...AND SOME HAIL LIKELY WITH THOSE STRONGER UPDRAFTS. TORNADO POTENTIAL IS NOT ZERO...BUT AGAIN WITH THE WEAK WIND FIELDS AND LIMITED VEERING...NOT EXPECTING THAT TO BE THE PRIMARY RISK. IF A TORNADO OCCURS IT WOULD MORE THAN LIKELY BE WEAK. K INDICES ARE HIGH...AND LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. THE CLOSED H500 MB CIRCULATION IS FORECASTED TO MIGRATE INTO NORTHWEST KANSAS BY SUNDAY MORNING...AND CONTINUE EAST ACROSS KANSAS DURING THE DAY. A SMALL DEFORMATION BAND OF PRECIPITATION IS LIKELY ON THE NORTH AND WEST SIDE OF THE TRACK. THE EXACT TRACK OF THE LOW CENTER IS UNCERTAIN...AS CONVECTION LIKELY TO INFLUENCE THE MASS FIELD AND EXPECT THE FINAL TRACK COULD END UP A LITTLE FARTHER NORTH. THIS IS HINTED IN THE LATEST RUN OF THE RAP MODEL. OTHERWISE A COLD FRONT ASSOCIATED WITH A SEPARATE NORTHERN STREAM SYSTEM WILL CRASH THROUGH THE AREA...BRINGING GUSTY NORTHWEST WINDS TO THE REGION. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 255 PM CDT SAT APR 18 2015 MEDIUM RANGE...(SUNDAY NIGHT THROUGH TUESDAY) THE UPPER LEVEL LOW ACROSS COLORADO WILL LIFT OUT AND COLLIDE WITH AN UPPER LEVEL SHORT WAVE ACROSS ACROSS THE NORTHERN GREAT LAKES FORMING A VERY LARGE CLOSED UPPER LOW. UPSTREAM HEIGHTS RISE SHARPLY ACROSS NRN CANADA SUPPORTING A BROAD AREA OF HIGH PRESSURE WHICH CIRCULATE COOL AIR SOUTH THROUGH THE PLAINS AND MIDWEST. THIS KEEPS THE FORECAST AREA IN COOL NORTHWEST FLOW. DAYTIME MIXING PRODUCES PARTLY CLOUDY SKIES MONDAY AND TUESDAY PLACING A LIMIT ON HEATING. MONDAY WOULD BE A WINDY DAY WITH NORTHWEST WINDS INCREASING TO 20 TO 30 MPH IN THE AFTN WHICH WEAKEN AT SUNSET. WINDS STAY REASONABLY STRONG SUNDAY NIGHT ALSO. THE EFFECT ON TEMPERATURES WOULD BE FOR LOWS MONDAY MORNING FALLING INTO THE UPPER 20S ACROSS WESTERN NEBRASKA BUT ABOVE FREEZING EAST OF HIGHWAY 83. LOWS FALL BELOW FREEZING EVERYWHERE MONDAY NIGHT EXCEPT ALONG HIGHWAY 281. HIGHS RISE INTO THE 50S MONDAY AND LOWER 60S TUESDAY. THE FORECAST IS DRY AND THE MODELS INDICATE DEW POINTS FALL INTO TEENS AND 20S SUNDAY NIGHT THROUGH TUESDAY. THE RISK TO THE FORECAST IS THAT THE VERY DRY AIR COULD SUPPORT COLDER LOWS THAN FORECAST BUT THAT WOULD COMPETE DIRECTLY WITH THE WARM WET GROUND FROM THE HEAVY RAINFALL. EXTENDED RANGE...(TUESDAY NIGHT THROUGH SATURDAY) A RIDGE IN WESTERN NORTH AMERICA CONTINUES TO BUILD INTO THE NORTHWEST TERRITORIES AND NORTHERN ALBERTA OPENING UP A PATH FROM NUNAVUT IN EXTREME NORTHERN CANADA TO NORTH CENTRAL AND NORTHEAST NEBRASKA. AS A RESULT...TEMPERATURES ARE EXPECTED TO BE A LITTLE BELOW THE SEASONAL AVERAGES IN THE NORTHEAST NEBRASKA SANDHILLS AND THE NIOBRARA VALLEY WITH NIGHTTIME TEMPERATURES AT OR BELOW FREEZING INTO FRIDAY MORNING. EVEN IN THE WESTERN SANDHILLS...THE EASTERN PANHANDLE AND SOUTHWEST NEBRASKA WILL BE SLIGHTLY BELOW AVERAGE WITH LOWS IN THE LOW TO MID 30S. IN THE SOUTHWEST STATES...A TROUGH DIGS INTO SOUTHERN CALIFORNIA RESULTING IN SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL PLAINS. A WEAK INVERTED TROUGH MOVING ACROSS THE PLAINS COULD BRING THE POSSIBILITY OF SHOWERS TO CENTRAL AND WESTERN NEBRASKA THURSDAY THROUGH SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM CDT SAT APR 18 2015 THE THUNDERSTORMS IN CENTRAL NEBRASKA ARE WEAKENING. LATER TONIGHT...AS THE UPPER LOW MAKES ITS WAY ONTO THE PLAINS... SCATTERED SHOWERS WILL COALESCE INTO WIDESPREAD RAIN AFTER 06Z SOUTH OF AN ONL-MHN-OGA LINE. THEN...AS A FRONT COME THROUGH...RAIN WILL END FROM THE NORTH IN CENTRAL NEBRASKA BY 11Z AND IN SOUTH CENTRAL AND SOUTHWEST NEBRASKA EARLY AFTERNOON. THE RAIN IS EXPECTED TO END BBW-LBF-IML AROUND 13Z. AFTER 08Z...WIND WILL SHIFT TO 340-360 AT 10-16KT AND THEN INCREASE TO 14-18G24-30KT BY 14Z && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SPRINGER SHORT TERM...TAYLOR LONG TERM...CDC/SPRINGER AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
337 AM MDT SUN APR 19 2015 .SYNOPSIS... AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST. DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE OVER THE NORTH THROUGH NEXT WEEKEND. && .DISCUSSION... THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT. ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT TREND TOWARD NORMAL FOR THE FAR WEST. AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY. BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY DEFINED SHORTWAVE TROUGHS AND RIDGES. GUYER && .FIRE WEATHER... WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS DIMINISHED SOMEWHAT. A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN. GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST. LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF NORMAL EAST...VERY CLOSE TO NORMAL WEST. THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH AID OF AFTN HEATING. WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE THU AFTN. NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY SEE SOME EROSION OF VENTILATION RATES. 43 && .AVIATION... 06Z TAF CYCLE A POTENT BACKDOOR COLD FRONT WILL SLIDE DOWN THE ERN PLAINS OVERNIGHT INTO EARLY SUNDAY MORNING. STRONG NORTH WINDS OF 20 TO 30KT WITH GUSTS NEAR 45 KT WILL BE POSSIBLE ACROSS NE NM...ESPECIALLY BETWEEN 09Z AND 18Z SUNDAY. THE BACKDOOR FRONT WILL RESULT IN ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS SUNDAY...MAINLY OVER THE NORTHERN AND SOUTHWEST MOUNTAINS AND ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN INCLUDING KLVS. WITH WEST TO NORTHWEST FLOW ALOFT IN PLACE AND ELY UPSLOPE SFC FLOW...A FEW STRONG STORMS ARE POSSIBLE DURING THE LATE AFTERNOON AND EARLY EVENING FROM THE EAST SLOPES SANGRE DE CRISTOS EWD TO THE NE PLAINS. 33 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 65 34 70 37 / 5 0 5 5 DULCE........................... 62 25 62 28 / 10 10 20 10 CUBA............................ 62 32 64 35 / 10 10 10 10 GALLUP.......................... 65 29 69 32 / 5 5 10 5 EL MORRO........................ 59 33 64 35 / 10 10 10 5 GRANTS.......................... 63 29 67 31 / 10 5 10 5 QUEMADO......................... 61 37 65 37 / 10 5 10 5 GLENWOOD........................ 74 45 76 44 / 5 5 5 5 CHAMA........................... 54 25 55 25 / 20 20 20 10 LOS ALAMOS...................... 57 40 62 41 / 20 10 20 10 PECOS........................... 57 33 60 38 / 10 10 10 10 CERRO/QUESTA.................... 54 24 55 26 / 20 30 30 20 RED RIVER....................... 45 25 46 29 / 30 50 40 30 ANGEL FIRE...................... 48 21 51 24 / 30 30 30 20 TAOS............................ 55 28 59 30 / 20 20 20 20 MORA............................ 54 29 58 34 / 20 20 20 20 ESPANOLA........................ 62 38 66 39 / 10 10 10 10 SANTA FE........................ 57 38 61 41 / 10 10 10 10 SANTA FE AIRPORT................ 63 34 66 36 / 10 10 10 10 ALBUQUERQUE FOOTHILLS........... 65 43 69 46 / 10 5 5 10 ALBUQUERQUE HEIGHTS............. 67 44 71 46 / 5 5 5 5 ALBUQUERQUE VALLEY.............. 68 39 72 41 / 5 5 5 5 ALBUQUERQUE WEST MESA........... 69 41 71 45 / 5 5 5 5 LOS LUNAS....................... 70 36 74 39 / 5 5 5 5 RIO RANCHO...................... 68 42 70 46 / 5 5 5 5 SOCORRO......................... 71 44 75 46 / 10 5 10 5 SANDIA PARK/CEDAR CREST......... 62 38 65 44 / 10 10 10 10 TIJERAS......................... 65 38 67 43 / 10 10 10 10 MORIARTY/ESTANCIA............... 61 29 66 32 / 10 10 10 10 CLINES CORNERS.................. 61 32 63 39 / 10 10 10 10 GRAN QUIVIRA.................... 63 39 66 42 / 10 10 10 10 CARRIZOZO....................... 68 44 70 46 / 10 10 5 5 RUIDOSO......................... 65 37 65 43 / 10 10 5 5 CAPULIN......................... 48 30 55 35 / 40 30 30 30 RATON........................... 54 28 58 31 / 20 40 30 30 SPRINGER........................ 55 31 64 35 / 10 50 20 30 LAS VEGAS....................... 57 29 61 37 / 10 20 20 20 CLAYTON......................... 56 33 63 40 / 20 10 20 40 ROY............................. 56 30 63 37 / 5 20 20 30 CONCHAS......................... 63 39 70 44 / 0 5 10 20 SANTA ROSA...................... 64 35 69 43 / 5 5 10 10 TUCUMCARI....................... 66 35 72 43 / 0 5 10 30 CLOVIS.......................... 65 37 68 43 / 0 5 5 20 PORTALES........................ 68 38 70 45 / 0 0 0 20 FORT SUMNER..................... 67 38 70 44 / 0 5 5 10 ROSWELL......................... 71 44 72 45 / 0 5 0 5 PICACHO......................... 68 40 69 44 / 5 10 5 5 ELK............................. 65 38 65 44 / 10 10 5 5 && .ABQ WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING ZONES...NMZ530. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
121 AM EDT SUN APR 19 2015 .SYNOPSIS... AN APPROACHING FRONTAL SYSTEM WILL BRING SHOWERS AND A CHANCE OF THUNDERSTORMS TODAY THROUGH MONDAY. A FEW STORMS COULD BE STRONG TO SEVERE MONDAY. DRY AND SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND WEDNESDAY. A WEAK COLD FRONT MAY BRING SHOWERS AND ISOLATED THUNDERSTORMS INTO LATE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 130 AM SUNDAY...WE`RE PROBABLY AT A CONVECTIVE MINIMUM RIGHT NOW. LATEST HRRR AND HRRRX MODELS SHOW AN INCREASE IN SHOWER ACTIVITY LATE TONIGHT...AND ESPECIALLY AROUND DAYBREAK ACROSS THE PEE DEE REGION AS THE DEVELOPING WARM FRONT AND BETTER UPPER SUPPORT ARRIVES FROM THE SOUTHWEST. A FEW DOWNWARD TWEAKS HAVE BEEN MADE TO FORECAST LOW TEMPS NEAR THE COAST. DISCUSSION FROM 1030 PM FOLLOWS... THE DIURNALLY INDUCED CONVECTION CONTINUES TO DISSIPATE ACROSS THE FA AND IS NOW BASICALLY WIDELY SCATTERED IN COVERAGE...AND IN THE FORM OF LIGHT RAIN SHOWERS. WILL DROP POPS TO ISOLATED IN COVERAGE FOR PORTIONS OF THE ILM CWA BUT ONLY FOR TEMPORARILY THIS EVENING UP TO A FEW HRS AFTER MIDNIGHT. WITH A SFC COLD FRONTAL BOUNDARY DROPPING SOUTH AND POSSIBLY BACKDOORING THE FA OVERNIGHT BEFORE TEMPORARILY STALLING...AND A FEW LEFTOVER SHALLOW MESOSCALE SFC BOUNDARIES PRESENT. WILL NOT ENTIRELY REMOVE PCPN FOR THE REMAINDER OF THE OVERNIGHT. IN FACT...DURING THE PRE-DAWN HRS OF SUNDAY THRU DAYBREAK...LOOK FOR POPS TO RAMP BACK UP ACROSS THE ILM CWA FROM SW TO NE...WITH A GOOD CHANCE OR POSSIBLY LIKELY ACROSS THE SW PORTIONS BY SUNRISE SUN. INCREASING MID-LEVEL DYNAMICS FROM A SERIES OF S/W MID-LEVEL TROUGHS...PLENTY OF AVBL MOISTURE WITH 00Z SUNDAY NEARBY SOUNDINGS AND MODEL PROGS INDICATING PWS OF 1.5 TO 1.75 INCHES...AND AS MENTIONED EARLIER...SFC BASED BOUNDARIES WILL LIE ACROSS THE FA ALLOWING FOR SFC BASED CONVERGENCE TO AID MORE ORGANIZED PCPN DEVELOPMENT TO COMPLEMENT THE MID-LEVEL SUPPORT. LATEST MIN TEMPS FORECAST OVERNIGHT LOOKING AOK AND SEE NO REASON TO FURTHER TWEAK FROM EARLIER CHANGES. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...PRIMARY HEADLINES INCLUDE POTENTIAL FOR A GOOD SOAKING OF RAIN...AND A FEW STRONG THUNDERSTORMS. MONDAY APPEARS THE MORE OPTIMUM SET-UP FOR STRONG/SEVERE STORMS WITH MORE ROBUST KINEMATIC FIELDS AND STRONGER LOW-LEVEL HEATING JUST AHEAD OF A COLD FRONT. EXTENSIVE CLOUD CANOPY SUNDAY MAY IMPEDE CONVECTION INITIATION/GROWTH. SUNDAY MEANWHILE OFFERS THE HIGHER RAIN AMOUNTS AS COLUMN MOISTURE SURGES AS A WARM FRONT LIFTS N OF THE AREA AND PRECIPITABLE WATERS SURGE TO 1.8". SEVERAL MCV PERTURBATIONS ALOFT SWEPT NE IN WAKE OF THE WARM FRONT MAY SUSTAIN SHOWER AND STORM CHANCES INTO SUNDAY NIGHT. CURRENT IR ANIMATIONS SHOW COLD TOPS INDEED FLARING ALONG THE NORTHERN GULF OF MEXICO. WPC QPF DEPICTIONS SHOW .75-1 INCH BASIN AVERAGES SUNDAY...AND WITH CONVECTIVE ELEMENTS...SOME AREAS LIKELY TO RECEIVE GREATER AMOUNTS. MONDAY LESS BASIN QPF BUT MORE POWERFUL STORMS IN THE CARDS WITH MAXIMUMS RISING WELL INTO THE 80S AND PARTIAL SUNSHINE AIDING INSOLATION AND CELL POPS. SPC PAINTS SLIGHT RISK FOR BOTH LATE SUNDAY AND MONDAY. BALMY PERIOD OVERALL AND BEST GUESS ON FRONTAL PASSAGE NOW SLATED AROUND OR AFTER DAYBREAK TUESDAY. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 3 PM SATURDAY...AN ALMOST WINTERLIKE LOOKING UPPER PATTERN FOR MOST OF THE PERIOD WITH A LARGE VORTEX IN THE VICINITY OF THE GREAT LAKES. WESTERLY FLOW AROUND THIS FEATURE WILL KEEP MUCH OF THE COLUMN DRY AND LEAD TO RAIN-FREE CONDITIONS LOCALLY. LOW LEVELS WILL BE DRY AS WELL THROUGH SOME TIME WEDNESDAY AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. SOON THEREAFTER THIS HIGH MOVES OFFSHORE AND SOME MOISTENING RETURN FLOW ENSUES. SOME GUIDANCE SHOWING THIS CALLING FOR RAIN AS SOON AS THURSDAY BUT GIVEN THE AFOREMENTIONED DOWNSLOPE FLOW STILL FEEL THAT THURSDAY NIGHT INTO FRIDAY IS THE BETTER DAY TO INTRODUCE SOME RAIN CHANCES ESPECIALLY GIVEN THE APPROACH OF A COLD FRONT. THOUGH THIS SURFACE BOUNDARY MAY LIE TO OUR SOUTH ON SATURDAY SOME LOW LEVEL BAROCLINICITY PAIRED WITH MID LEVEL VORT APPROACHING TO KEEP RAIN IN THE FORECAST. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...A MIXTURE OF VFR/MVFR THROUGH THE EARLY OVERNIGHT HOURS DUE TO LOW CIGS AND PATCHY FOG...WITH CONDITIONS DETERIORATING TO MVFR/IFR LATE OVERNIGHT AND THROUGH INTO SUNDAY WITH AN APPROACHING FRONTAL SYSTEM. OVERALL...VFR PREVAILS ACROSS THE AREA TONIGHT WITH LIGHT AND VARIABLE WINDS AND INTERMITTENT LOW CIGS...AS WELL AS MID TO HIGH CLOUDS AS SEEN FROM LATEST SATELLITE IMAGERY. OBSERVATIONS ARE ALSO DEPICTING PATCHY FOG INLAND...JUST AT MARGINAL VFR/MVFR STATUS ATTM. WITH ISOLATED LIGHT SHOWERS SLOWLY MOVING ACROSS THE AREA...ANTICIPATE CONDITIONS TO DETERIORATE OVERNIGHT CREATING WIDESPREAD MVFR/IFR DUE TO LOW CIGS AND AREAS OF FOG. AFTER DAYBREAK...EXPECT EASTERLY WINDS AOB 12 KTS IN THE MORNING TO BECOME EAST-SOUTHEAST BY AFTERNOON WITH GUSTS UP NEAR 20 KTS POSSIBLE WITH A FRONTAL SYSTEM TO AFFECT THE AREA. A MIXTURE OF VFR/MVFR/IFR IS ANTICIPATED AS SHOWERS AND ISOLATED THUNDERSTORMS...ALONG WITH LOW CIGS AND PATCHY AREAS OF FOG MOVE THROUGHOUT THE AREA THROUGH THE END OF THE VALID TAF PERIOD. EXTENDED OUTLOOK...MVFR/IFR POSSIBLE INTO MONDAY WITH SHOWERS AND ISOLATED THUNDERSTORMS. A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS TUESDAY. POSSIBLE SHOWERS RETURNING LATER IN THE WEEK. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM SUNDAY...BASED ON OBSERVATIONS ALONG THE COAST I HAVE BACKED WIND DIRECTIONS MORE NORTHERLY. NO OTHER SIGNIFICANT CHANGES ARE NEEDED. DISCUSSION FROM 1030 PM FOLLOWS... NO CHANGES TO THE WINDS FROM THE PREVIOUS UPDATE. WINDS TO BECOME NE- E THROUGHOUT...AND INCREASE TO 10-15 KT...WITH THE HIGHER WIND SPEEDS FROM CAPE FEAR NORTHWARD. THIS A RESULT OF THE BACKDOOR FRONTS POSITIONING WITH ENOUGH TIGHTENING OF THE SFC PG AS RIDGING EXTENDS SOUTH FROM THE NE STATES SFC HIGH. SIGNIFICANT SEAS WILL RUN 2 TO 4 FT...WITH THE 4 FOOTERS PRIMARILY ACROSS THE OUTER WATERS OFF CAPE FEAR...AND NORTHWARD. DOMINANT PERIODS WILL RUN 8 TO 9 SECONDS IN RESPONSE TO THE 2 TO 3 FOOT ESE GROUND SWELL. HAVE REDUCED THE POPS FOR THIS EVENING BASED ON LATEST 88D TRENDS. SHOULD SEE POPS INCREASE DURING THE PRE-DAWN SUN HRS. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...EXERCISE CAUTION OR ADVISORY MARINE REGIME ON TAP THIS PERIOD AS A FRONTAL SYSTEM APPROACHES AND WORSENS LOCAL MARINE CONDITIONS. WAVE GROWTH HOWEVER MAY BE LIMITED SINCE SE-S WIND FLOW HAS LIMITED STAYING TIME BEFORE WINDS GO SW EARLY ON MONDAY. HAVE CAPPED SEAS AT 5 FEET SUNDAY FOR NOW WITH GUSTS TO 20 KT AHEAD OF THE COLD FRONT...SET TO CROSS THE WATERS TUESDAY MORNING. SEVERAL STRONG TSTMS ARE POSSIBLE SUNDAY THROUGH THROUGH EARLY TUESDAY AND SPECIAL MARINE WARNINGS MAY BE NEEDED AT TIMES. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 3 PM SATURDAY...OFFSHORE/NORTHWESTERLY POST COLD FRONTAL FLOW REGIME ON TUESDAY WILL GROW LIGHTER LATE IN THE DAY AND AT NIGHT AS CENTER OF HIGH PRESSURE APPROACHES. THE CENTER OF HIGH PRESSURE MOVES OFFSHORE BY WEDNESDAY EVENING. THIS WILL BRING A PERIOD OF VERY LIGHT GRADIENT WHEREIN WINDS REMAIN UNDER 10 KNOTS AND VEER IN DIRECTION FOR AN EXTENDED TIME UNTIL FINALLY SETTLING ON SOUTHERLY BY WED EVE. SUCH LIGHT WINDS IN THE ABSENCE OF SWELL ENERGY OUGHT TO BE GOOD FOR MINIMAL SEAS OF 2 FT OR LESS. THE HIGH MOVES FURTHER OFFSHORE ON THURSDAY ALLOWING FOR A ONE CATEGORY RISE IN WINDS AND A WAVES FORECAST RISING TO JUST THE 2 TO 3 FT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...DCH/TRA SHORT TERM...MJC LONG TERM...MBB AVIATION...SGL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1218 AM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 1218 AM CDT SUN APR 19 2015 NO CHANGES MADE TO THE PREVIOUS FORECAST. UPDATE ISSUED AT 955 PM CDT SAT APR 18 2015 ALTHOUGH THE 01 UTC RAP/HRRR ARE OVERDOING THE QPF IN MOST AREAS...THEY HAVE A GOOD HANDLE ON THE AREA OF PRECIPITATION AND HAVE UTILIZED THIS BLEND FOR POPS THROUGH THE NIGHT AND INTO SUNDAY. BEST PRECIPITATION CHANCES WILL REMAIN OVER THE SOUTHEAST FORECAST AREA. EXPECT PRECIPITATION TO FILL IN OVER THE JAMES RIVER VALLEY OVER THE NEXT FEW HOURS. PRECIPITATION BAND FROM SOUTHWEST INTO NORTH CENTRAL NORTH DAKOTA WILL MOVE ACROSS CENTRAL NORTH DAKOTA AS WELL...WITH BEST PRECIPITATION CHANCES OVER BISMARCK THROUGH AROUND MIDNIGHT. PRECIPITATION IS EXPECTED TO MOVE OUT OF THE JAMES RIVER VALLEY AROUND 12-14Z...LOWERED POPS ACROSS THE AREA EARLY MORNING...THEN BUMPED THEM UP MID TO LATE MORNING INTO THE AFTERNOON AS WRAP AROUND MOISTURE MOVES INTO THE AREA ON THE BACK SIDE OF THE EXITING SYSTEM. UPDATE ISSUED AT |748 PM CDT SAT APR 18 2015 QUICK UPDATE FOR POPS BASED ON LATEST RADAR...ALSO REMOVED THUNDER OVER THE SOUTHWEST. HEAVIEST SHOWERS LOOK TO REMAIN OVER THE FAR SOUTH CENTRAL AND INTO EASTERN NORTH DAKOTA THIS EVENING. BAND MOVING EAST ACROSS THE CENTRAL FROM AROUND MINOT TO GARRISON TO HEBRON SHOULD HELP MOISTEN THE ATMOSPHERE NEAR KBIS THIS EVENING. SHOWERS IN THE FAR SOUTH CENTRAL MOVING TOWARD BISMARCK ARE NOW DISSIPATING ON THE NORTHERN FRINGE. 19 APRIL 00 UTC SOUNDING STILL SHOWS QUITE A BIT OF DRY AIR BELOW THE MID AND UPPER LEVEL MOISTURE BEGINNING AROUND 10K FEET. UPDATE ISSUED AT 638 PM CDT SAT APR 18 2015 UPPER LEVEL LOW OVER SOUTHEAST COLORADO WITH A SHORTWAVE TROUGH LIFTING NORTH THROUGH WESTERN SOUTH DAKOTA IS PUSHING SHOWERS INTO CENTRAL NORTH DAKOTA. A NORTHERN STREAM WAVE WITH MORE INSOLATION TO WORK WITH IS PRODUCING A LINE OF POST FRONTAL SHOWERS AND ISOLATED THUNDER OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA. THE THUNDER IS LIMITED TO THE SOUTHWEST...AND WITH THE LOSS OF DAYTIME HEATING...DO NOT EXPECT THUNDER TO CONTINUE MUCH LONGER. WILL KEEP A MENTION THROUGH THE EARLY EVENING. EXPECT SHOWERS TO INCREASE OVER SOUTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS EVENING AS THE SHORTWAVES LIFTING NORTH AND TRACKING EAST CONVERGE OVER CENTRAL NORTH DAKOTA...AND THEN MOVE INTO BETTER MOISTURE AND SURFACE SUPPORT AS THE SYSTEM MOVES INTO EASTERN NORTH DAKOTA LATE TONIGHT. ADJUSTED POPS/SKY COVER BASED MAINLY ON SHORT TERM CONSENSUS MODEL AND LATEST RADAR. OTHERWISE NO SIGNIFICANT CHANGES FROM THE GOING FORECAST. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 RAINFALL POTENTIAL THROUGH TONIGHT HIGHLIGHTS THE SHORT TERM FORECAST. AS OF 1930 UTC...A COLD FRONT WAS JUST ENTERING NORTHWEST NORTH DAKOTA AND WILL CONTINUE TO PROPAGATE THROUGH CENTRAL NORTH DAKOTA THIS EVENING. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WITH WEAK INSTABILITY HAVE DEVELOPED ALONG THIS FRONT AND WILL APPROACH THE HIGHWAY 83 CORRIDOR BY 01-02 UTC. AS CYCLOGENESIS OCCURS ACROSS EASTERN SOUTH DAKOTA THROUGH THE NIGHT AND THE NORTHERN STREAM WAVE ASSOCIATED WITH THE COLD FRONT PHASES WITH THE LOW TO THE SOUTH...RAINFALL COVERAGE WILL INCREASE ACROSS CENTRAL NORTH DAKOTA THROUGH THE EVENING AND NIGHT. THEREAFTER...A WINDY SUNDAY IS FORECAST IN THE WAKE OF THE NOW DEEPENING LOW ACROSS MINNESOTA. AT THIS TIME...WIND GUSTS APPEAR TO STAY BELOW ADVISORY CRITERIA WITH 30 TO 35 KTS TO MIX IN COLD AIR ADVECTION. SCATTERED LIGHT RAIN SHOWERS ARE ALSO EXPECTED IN WRAP AROUND MOISTURE WITH PERHAPS A FEW SNOWFLAKES MIXING IN SUNDAY MORNING AS TEMPERATURES FALL INTO THE MID 30S NORTHWEST AND NORTH CENTRAL. GIVEN GOOD AGREEMENT...WILL WEIGH HEAVILY ON THE 16-18 UTC HRRR ITERATIONS BLENDED TO THE GLOBAL 12 UTC DETERMINISTIC AND ENSEMBLE SUITE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT SAT APR 18 2015 WINDY WITH SCATTERED SHOWERS TO BEGIN THE EXTENDED...COOL AND DRY THROUGH THE REMAINDER OF THE WEEK. AS THE MAIN SURFACE LOW ENTERS NORTHERN MINNESOTA AND SOUTHERN CANADA...MOISTURE SHOULD WRAP AROUND THE BACKSIDE...PROVIDING NORTH DAKOTA WITH SOME SCATTERED LIGHT RAIN. THE HIGH RESOLUTION SHORT TERM MODELS ARE A LITTLE MORE ROBUST WITH PRECIPITATION COVERAGE THAN THE GLOBAL MODELS (ECMWF/GFS). WITH THE LOW REMAINING NEARBY AND REMAINING UNDER THE INFLUENCE OF A FAVORABLE JET STREAK...LIGHT SHOWERS HERE AND THERE AREN`T OUT OF THE QUESTION THROUGH TUESDAY. GUSTY WINDS ARE EXPECTED THOUGH THE DAY SUNDAY AND MONDAY AS THE PRESSURE GRADIENT TIGHTENS WITH THE SURFACE LOW DEEPENING AND PROPAGATING TOWARD THE GREAT LAKES. THESE GUSTY NORTHWEST WINDS WILL BE ADVECTING DRIER AIR INTO THE AREA. THIS COULD CREATE RATHER CRITICAL FIRE CONDITIONS MONDAY AS RELATIVE HUMIDITY DROPS BELOW 20 PERCENT. THROUGH THE REMAINDER OF THE WORK WEEK...UPPER LOW SLOWLY WORKS OFF TO THE EAST KEEPING NORTH/NORTHWESTERLY FLOW OVER OUR AREA. WITH THE EXCEPTION OF ISOLATED SHOWERS EARLY THIS WEEK...DRY WEATHER IS EXPECTED. TEMPERATURES WILL REMAIN A BIT BELOW AVERAGE WITH READINGS IN THE 50S FOR HIGHS AND 20S/30S FOR LOWS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1218 AM CDT SUN APR 19 2015 WIDESPREAD RAIN IS EXPECTED TO CONTINUE THROUGH 06Z MONDAY. KBIS/KJMS HAVE THE GREATEST CHANCES FOR RAIN WITH PERIODS OF MVFR CONDITIONS POSSIBLE AT EACH OF THE TAF SITES. && .FIRE WEATHER... ISSUED AT 315 PM CDT SAT APR 18 2015 CRITICAL FIRE WEATHER CONDITIONS MAY BE POSSIBLE ON MONDAY...AND THIS WILL NEED TO BE MONITORED. WHILE TEMPERATURES WILL ONLY BE IN THE 50S...MINIMUM RELATIVE HUMIDITY LEVELS OF 15 TO 20 PERCENT AND NORTHWEST WINDS OF 25 TO 35 MPH ARE POSSIBLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AC SHORT TERM...AYD LONG TERM...AJ AVIATION...AC FIRE WEATHER...AYD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1135 PM CDT SAT APR 18 2015 .UPDATE...FOR AVIATION. && .AVIATION... 06Z TAFS...BNA/CKV/CSV...A LOW PRESSURE SYSTEM AND WARM FRONT WILL LIFT INTO MID TN OVERNIGHT BRINGING WIDESPREAD SHOWERS. LOOK FOR -SHRA WITH MVFR CIGS/VSBYS TO DEVELOP AROUND 08Z...WITH TEMPO IFR AND SOME LIFR 10Z-15Z. THE MAIN BAND OF MOISTURE WILL LIFT NORTH OF MID TN BY 18Z. ANOTHER SYSTEM WILL APPROACH SUNDAY AFTERNOON AND EVENING WITH SCATTERED TSRA...SOME POSSIBLY SEVERE. 13 && .PREV DISCUSSION... /ISSUED 1006 PM CDT SAT APR 18 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO INCREASE SHWR/TSTM CHANCES FROM SW TO NE REST OF EVENING AND OVERNIGHT. TWEAKED HRLY TEMP...DEWPOINT... SKY...AND WIND SPEED/DIRECTION GRIDS ALSO. REMAINDER OF FORECAST REMAINS ON TRACK. PREV DISCUSSION... /ISSUED 530 PM CDT SAT APR 18 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT REGIONAL SFC OBS...SATELLITE...AND MOSAIC RADAR TRENDS ALONG WITH THE LATEST IN SHORT RANGE MODEL CONSENSUS...THUS MAINTAINING ISO SHWRS/TSTMS THRU AT LEAST THE MID EVENING HRS. BULK OF SHWR/TSTMS ACTIVITY SHOULD SPREAD FROM THE SW TO THE NE ACROSS THE MID STATE AFTER MIDNIGHT. PREV DISCUSSION.../ISSUED 351 PM CDT SAT APR 18 2015/ DISCUSSION... AS AN UPPER TROUGH CENTERED OVER THE CENTRAL PLAINS MOVES EAST THIS AFTERNOON AND OVERNIGHT IT WILL INFLUENCE SHOWERS AND THUNDERSTORMS TO CONTINUE THEIR TREK NORTHWARD THROUGH MIDDLE TN. HRRR IS FORECASTING SCATTERED AFTERNOON ACTIVITY TO MOVE INTO KENTUCKY AND ANOTHER WAVE OF PRECIP TO SPREAD INTO MIDDLE TENNESSEE FROM THE SOUTH BEFORE MIDNIGHT. PWAT VALUES WILL BE AROUND 1.5 INCHES FOR SEVERAL HOURS OVERNIGHT TONIGHT. WITH THE GROUND ALREADY SATURATED FROM THIS PAST WEEK`S RAINFALL...WE COULD SEE CREEKS AND STREAMS RISE PRETTY QUICKLY DURING THE OVERNIGHT HOURS...WATCH FOR MINOR FLOODING IN LOW LYING AREAS AND PONDING OF WATER ON ROADWAYS OVERNIGHT. WHILE THERE MAY BE STORMS AROUND...NOT EXPECTING ANYTHING STRONG OR SEVERE TONIGHT. BETWEEN LATE SUNDAY MORNING AND EARLY AFTERNOON THE DEEPEST MOISTURE WILL PUSH NORTH OF OUR AREA. LINGERING CLOUD COVER...ESPECIALLY OVER THE NORTHEASTERN PORTION OF THE CWA MAY INHIBIT INSTABILITY...BUT CLOUDS SHOULD BREAK UP ENOUGH DURING THE AFTERNOON HOURS TO ALLOW FOR TEMPERATURES TO WARM INTO THE LOW 70S ALONG THE CUMBERLAND PLATEAU AND MID 70S ELSEWHERE. THIS SHOULD BE WARM ENOUGH TO INITIATE ISOLATED TO SCATTERED STORMS THROUGHOUT THE AFTERNOON. CURRENTLY SPC HAS THE MID-STATE IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR SUNDAY AFTERNOON THROUGH SUNDAY NIGHT. THE MAIN THREAT WITH ANY STORMS DURING THIS TIME FRAME WILL BE DAMAGING WINDS AND HAIL. WE COULD SEE A COUPLE OF ROUNDS OF THUNDERSTORMS OVERNIGHT SUNDAY NIGHT AHEAD OF A SHORTWAVE AND ITS ASSOCIATED SURFACE LOW...WHICH STRENGTHEN OVER SOUTHERN ILLINOIS AND HEAD NORTHEAST ON MONDAY. THE FRONTAL PASSAGE ASSOCIATED WITH THE AFOREMENTIONED LOW WILL OCCUR ON MONDAY AND WILL ALLOW FOR TEMPERATURES TO COOL INTO THE 40S OVERNIGHT MONDAY NIGHT. ALL PRECIP SHOULD PUSH EAST OF THE TENNESSEE VALLEY TUESDAY NIGHT. A SURFACE HIGH MOVES IN ON TUESDAY AND GIVES US A MUCH NEEDED DRY AND RELATIVELY COOL DAY WITH HIGH TEMPERATURES IN THE MID 60S. THE NEXT CHANCE OF PRECIP ENTERS THE FORECAST WEDNESDAY EVENING AS A WEAK FRONT BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE AREA. COULD SEE A BREAK ON FRIDAY AS THAT MOISTURE PUSHES SOUTH...THEN ANOTHER SURFACE LOW BRINGS ADDITIONAL THUNDERSTORM CHANCES FRIDAY NIGHT. && .OHX WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1239 AM CDT SUN APR 19 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...WIND SPEEDS ARE DECREASING AS TEMPERATURES COOL TONIGHT. CLEAR SKIES WILL OPEN UP FOR SOME AREAS OF GROUND FOG TO DEEPEN THROUGH THE NIGHT AND REFLECTED THAT IN THE TAFS. BRO/HRL WILL LIKELY CONTINUE TO GET WORSE THROUGH THE NIGHT BUT MFE MAY HOLD ON VFR MOST OF THE EVENING WITH A LARGER SFC DEWPOINT DEPRESSION. DRIER AIR JUST ABOVE THE SURFACE SHOULD ALLOW CONDITIONS TO IMPROVE PRETTY QUICKLY THROUGH MID MORNING. THERE IS A CONDITIONAL RISK FOR CONVECTION MAINLY THIS AFTERNOON. /68-JGG/ && .PREV DISCUSSION... /ISSUED 633 PM CDT SAT APR 18 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...A FEW SHOWERS HAVE ATTEMPTED TO GET GOING OVER THE COASTAL COUNTIES OF DEEP SOUTH TEXAS...HOWEVER THEY HAVE LARGELY FIZZLED OUT DUE TO A MORE STABLE ATMOSPHERE AIDED BY THE FRIDAY EVENING/NIGHT CONVECTION. CURRENT SATELLITE IMAGERY DOESN/T SHOW ANY CONVECTION IN THE VICINITY OF THE AERODROMES AND THIS HAS BEEN REMOVED FROM THE PREVIOUS TAFS. SURFACE WINDS WILL LIKELY REMAIN TOO STRONG OVERNIGHT TO ALLOW FOR SIGNIFICANT FORMATION OF FOG...BUT A TEMPO HAS BEEN INCLUDED FOR LIGHT FOG DEVELOPMENT FOR NEAR SUNRISE SUNDAY MORNING. PREVIOUSLY-LOWER CEILINGS HAVE BEEN BEEN DUMPED IN FAVOR OF THE MID AND HIGH LEVEL CLOUDINESS STREAMING OVERHEAD OUT OF NEIGHBORING MEXICO. OVERALL...VFR SHOULD BE THE RULE THROUGH THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 255 PM CDT SAT APR 18 2015/ SHORT TERM.../NOW THROUGH SUNDAY NIGHT/...A LOW PRESSURE SYSTEM CENTERED OVER EASTERN COLORADO IS MAINTAINING A BROAD AREA OF DIFFLUENT FLOW ALOFT OVER SOUTH CENTRAL TEXAS. ALSO ...A VERY ACTIVE SUB TROPICAL JET WITH SHORTWAVES WITHIN THE FLOW IS MOVING ACROSS SOUTH TX UNDERNEATH THIS LOW. THIS WILL CONTINUE TO PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE LOWER TEXAS GULF WATERS NORTHEAST INTO THE NORTHWEST GULF COAST. THERE IS AN AREA OF CONVECTION DEVELOPING ALONG A STATIONARY FRONT WHICH IS INTERACTING WITH PLENTY OF DEEP LAYER MOISTURE AND INSTABILITY POOLED ALONG IT. NEAR THE SURFACE DEW POINTS RANGE FROM 70 TO 75 DEGREES AND PRECIPITABLE WATER VALUES IN THE LAST KBRO 12Z SOUNDING SHOWS 1.96 INCHES AND THE LATEST RAP MODEL RUN SHOWS PWATS OF 1.5 TO 1.9 INCHES ESPECIALLY FROM HIDALGO COUNTY NORTHEAST AND EAST TOWARDS THE COAST. IN ADDITION...THE A SLIGHT BREAK IN THE CLOUDS IS ALLOWING FOR TEMPS TO WARM UP FOR THE NEXT FEW HOURS RESULTING IN INCREASE INSTABILITY ACROSS THE AREA. THIS WILL RESULT IN A CONTINUATION OF THE CONVECTION IN THE LATE AFTERNOON THROUGH THE OVERNIGHT HOURS THROUGH MIDNIGHT. THE CONVECTION WILL ALSO BE ENHANCE ALONG THE SIERRA MADRE AND MOVE NORTHEAST WHICH WILL MAKE ITS WAY INTO STARR AND HIDALGO COUNTY LATE EVENING INTO THE OVERNIGHT. THE MAIN THREAT WITH THESE STORMS WILL BE VERY HEAVY DOWNPOURS PRODUCING FLOODING...STRONG DAMAGING WINDS...HAIL AND FREQUENT CG LIGHTNING. INTO SUNDAY THE UPPER LEVEL JET WILL MAKE ITS WAY INTO SOUTH TEXAS PROVIDING SUPPORT FOR SOME CONVECTION TO DEVELOP SUNDAY AFTERNOON. EXPECT THE BEST POTENTIAL TO REMAIN ALONG THE COAST DUE TO THE INSTABILITY IN THE AREA. EXPECT A FEW OF THE STORMS TO BECOME SEVERE. THE CLOSED LOW BECOMES AN OPEN WAVE AS IT MOVES NORTHEAST INTO THE GREAT LAKES SUNDAY NIGHT PUSHING A COLD FRONT BEHIND IT ALONG THE CENTRAL PLAINS. THE CONVECTION WILL BE ENHANCE EVEN MORE OVERNIGHT SUNDAY ASSOCIATED TO THE BOUNDARY AS THE FRONT APPROACHES THE AREA. THE FRONT WILL ARRIVED BY THE END OF THE SHORT TERM OVER THE NORTHERN RANCHLANDS EARLY MONDAY MORNING. LONG TERM.../MONDAY THROUGH SATURDAY/...THE CLOSED LOW THAT HAS BEEN PLAUGING THE REGION WITH INTERMITTENT THUNDERSTORMS FOR THE LAST SEVERAL DAYS OPENS UP AND MERGES WITH A SHARP SHORTWAVE TROUGH UPPER TROUGH MOVING OUT OF CANADA. THE RESULT WILL BE A LARGE SCALE UPPER TROUGH DEVELOPING MONDAY INTO TUESDAY FROM THE NORTHERN PLAINS TO THE MIDWEST EXTENDING SOUTH INTO THE GULF SOUTH. THIS SENDS A COLD FRONT THROUGH SOUTH TEXAS SUNDAY NIGHT MOVING OFFSHORE THE LOWER TEXAS COAST AS EARLY AS SUNRISE MONDAY. MODELS ARE IN GOOD AGREEMENT AND REMAIN VERY CONSISTENT WITH THE EVOLUTION OF THE UPPER LEVEL AND SURFACE FEATURES. MODERATE TO HIGH CONFIDENCE IN THE FORECAST THROUGH TUESDAY MAINTAINS A LOWERING OF TEMPERATURES AND HIGHER CHANCES OF RAINFALL. THE COOLING OF THE LOWER ATMOSPHERE, LOWER LAPSE RATES, WEAKENING INSTABILITY WILL LIMIT THE THUNDERSTORM INTENSITY AND SEVERE WEATHER PROBABILITIES GO WAY LOW. GFS MODEL SOUNDING CONTINUE TO INDICATE THE BEST CHANCE OF THUNDER MONDAY MORNING AS THE FRONTAL BOUNDARY PASSES THROUGH BUT AS THE COOLER SURFACE AIR SETTLES IN THE INSTABILITY QUICKLY WEAKENS. ANY THUNDERSTORMS THAT LINGER INTO THE MONDAY AFTERNOON AND EVENING WILL BE ELEVATED. AS WE MOVE INTO TUESDAY AND THE REST OF THE WEEK THE FRONT INITIALLY REMAINS STATIONARY NEAR OR JUST SOUTH OF THE REGION KEEPING A MOIST EASTERLY FLOW AND POSSIBLY THE HIGHEST CHANCE OF RAIN. BOTH GFS AND ECMWF INDICATE ON AVERAGE THAT TUESDAY WILL HAVE THE BEST COVERAGE OF RAIN. THIS WILL ALSO KEEP TEMPERATURES BELOW NORMAL. AFTER TUESDAY FORECAST TRENDS DOWNWARD ON THE RAIN AND UP WITH THE TEMPERATURES. THE FRONT EVENTUALLY DISSIPATES OR MOVES BACK NORTH AS SHORTWAVE RIDGING BUILDS OVER WESTERN TEXAS WITH THE NEXT UPPER TROUGH APPROACHING THE PACIFIC COAST. GFS AND ECMWF DO LITTLE WITH THIS TROUGH AND IT LOOKS MUCH WEAKER THEN THE LAST FEW TROUGHS. SOME PERTURBATIONS DO ADVANCE THROUGH THE TROUGH AND RIDE ALONG STOUT SOUTHWESTERLY UPPER JET AND MAY SPARK SOME AFTERNOON CONVECTION OVER THE SIERRA MADRE AND THEN DRIFT INTO OUR CWA EACH AFTERNOON AND EVENING. THIS WILL BE INDICATED BY LOW GRADE POPS EACH LATE DAY AND EVENING. MARINE...NOW THROUGH SUNDAY NIGHT...THE SOUTHEAST WINDS WILL REMAIN LIGHT TO VARIABLE WITH LOW SEAS ACROSS THE GULF WATERS. THE MAIN CONCERNED THROUGH THE SHORT TERM WILL CONTINUE TO BE THE CONVECTION OVER THE GULF. THERE IS ENOUGH INSTABILITY IN THE AREA FROM A STATIONARY BOUNDARY PARALLEL TO THE COAST THAT WILL ENHANCE MORE CONVECTION INCREASING LATE THIS AFTERNOON AND CONTINUE OVERNIGHT. SUNDAY...THE POTENTIAL FOR CONVECTION WILL BEGIN TO DEVELOP IN THE AFTERNOON AND CONTINUE OVERNIGHT AS A COLD FRONT IS EXPECTED TO ARRIVED EARLY MONDAY INCREASING THE CHANCE OF RAIN EVEN MORE AND SHIFTING WINDS NORTHERLY. MONDAY THROUGH THURSDAY...COLD FRONT STILL ON TAP FOR EARLY MONDAY AS HIGH PRESSURE BUILDS DOWN THE CENTRAL PLAINS AS A MID LEVEL TROUGH DEEPENS INTO THE GULF SOUTH STATES. NORTHEAST WINDS INCREASE APPROACHING SMALL CRAFT ADVISORY CONDITIONS MONDAY AFTERNOON. SEAS TO RESPOND AND BUILD UPWARDS TO 6 FEET BY MONDAY NIGHT. MODERATE NORTHEAST TO EAST WINDS PERSIST TUESDAY AS THE FRONT BECOMES STATIONARY AND HIGH PRESSURE EXPANDS OVER THE CENTRAL GULF. A RETURN TO SOUTHEAST WINDS WEDNESDAY WITH A GRADUAL INCREASE THROUGH THE END OF THE WEEK IS EXPECTED. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS MONDAY AND TUESDAY WITH DECREASING COVERAGE MID TO LATE WEEK. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 72 77 72 78 / 30 40 40 40 BROWNSVILLE 72 78 72 80 / 30 50 40 40 HARLINGEN 71 80 70 79 / 40 50 40 40 MCALLEN 72 80 71 79 / 30 50 40 40 RIO GRANDE CITY 71 80 68 78 / 30 40 50 60 SOUTH PADRE ISLAND 72 76 72 76 / 30 40 40 40 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 68/60
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1137 PM CDT SAT APR 18 2015 .DISCUSSION... SEE 06Z AVIATION DISCUSSION. && .AVIATION... A LINE OF SHRA/TSRA WILL MOVE ACROSS THE NORTHERN TAF SITES BEFORE 06Z AND A PERIOD OF LIGHT RAIN WILL LIKELY PERSIST THROUGH 08S IN THE WAKE OF THIS LINE. THINGS ARE A BIT MORE MUDDLED AS TO HOW FAR SOUTH THIS LINE OF PRECIP WILL MOVE. LATEST HRRR SHOWS AN EASTWARD PUSH TO THE NORTHERN HALF AND A SOUTHWARD PUSH TO THE WESTERN HALF OF THE LINE. THE LINE IS STILL GENERATING WIND GUSTS BETWEEN 30-40 KNOTS SO FEEL IT IS BEST TO CARRY VCTS AND TEMPO A WIND GUST GROUP AS FAR AS KHOU AND KSGR. THE COLD POOL/PRESSURE RISES LOOK STRONG ENOUGH TO SUPPORT THE HRRR SOLUTION FURTHER SOUTH. WINDS WILL LIKELY BECOME W-SW OVERNIGHT AND SW ON SUNDAY IN RESPONSE TO LOW PRESSURE MOVING EAST ALONG THE RED RIVER. THE HRRR/GFS ADVERTISE A TIGHT GRADIENT IN THE AFTN SO ADDED GUSTS TO THE NORTHERN TAF SITES CLOSER TO THE TIGHTER GRADIENT. A COLD FRONT WILL APPROACH SE TX ON SUN AFTN. NAM 12 FCST SOUNDINGS SHOW AN UNSTABLE ATMOSPHERE OVER THE NORTH. JET DYNAMICS LOOK FAVORABLE WITH SE TX LYING IN A LFQ BETWEEN 18-00Z. HAVE ADDED VCTS FOR KCXO NORTHWARD. SOUNDINGS NOT QUITE AS UNSTABLE FOR THE HOUSTON TERMINALS TOMORROW AFTN BUT THIS COULD CHANGE. ONE LAST CAVEAT...IF SKIES CLEAR TONIGHT...WOULD EXPECT FOG TO DEVELOP BUT JUST NOT SURE HOW MUCH CLEARING WILL OCCUR IN THE WAKE OF TONIGHTS STORMS. 43 && .PREV DISCUSSION... /ISSUED 857 PM CDT SAT APR 18 2015/ DISCUSSION... WATCHING A LINE OF STRONG/SEVERE STORMS HEADING TOWARD OUR WESTERN COUNTIES THIS EVENING. AT THIS TIME...SPC WAS NOT PLANNING ON ISSUING ANY WATCHES WITH THIS STORM COMPLEX. IF THE LATEST RUN OF THE HRRR IS CORRECT...EXPECT THESE STORMS TO WEAKEN AS THEY MOVE INTO AND ACROSS OUR AREA. 42 PREV DISCUSSION... /ISSUED 445 PM CDT SAT APR 18 2015/ DISCUSSION... SENT OUT AN UPDATED FORECAST PACKAGE AND RAISED POPS AREA WIDE DUE TO ONGOING/DEVELOPING CONVECTION ACROSS THE COASTAL COUNTIES AND OFF THE COAST...AND FOR DEVELOPING STORMS OUT WEST THAT THE MODELS HAVE MOVING INTO THE AREA THIS EVENING. SOME OF THE STORMS COULD HAVE THE POTENTIAL TO BECOME STRONG OR SEVERE...WITH DAMAGING WINDS... LARGE HAIL...AND LOCALLY HEAVY RAINFALL THE PRIMARY SEVERE WEATHER THREATS. 42 MARINE... AN UPPER LEVEL DISTURBANCE WILL GENERATE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL WATERS THIS EVENING. SOME STORMS COULD BE STRONG. OTHERWISE...ONSHORE FLOW WILL PERSIST THROUGH SUNDAY. A COLD FRONT WILL PUSH OFF THE COAST SUNDAY NIGHT WITH MODERATE OFFSHORE WINDS IN ITS WAKE. WINDS WILL DIMINISH AND VEER BACK TO THE SOUTHEAST BY LATE TUESDAY NIGHT AS HIGH PRESSURE PUSHES OFF TO THE EAST. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 63 85 56 75 54 / 60 20 10 10 20 HOUSTON (IAH) 64 85 61 78 57 / 50 20 20 10 10 GALVESTON (GLS) 69 81 66 77 66 / 50 20 20 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...42 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
147 AM EDT SUN APR 19 2015 .SYNOPSIS... HIGH PRESSURE WILL DRIFT EAST TONIGHT ALLOWING CLOUDS FROM LOW PRESSURE OVER THE TENNESSEE VALLEY TO SPREAD ACROSS THE REGION OVERNIGHT. RAIN...HEAVY AT TIMES...WILL FALL SUNDAY INTO SUNDAY NIGHT BEFORE A COLD FRONT CROSSES THE REGION WITH A CHANCE OF SHOWERS AND POTENTIALLY STRONG STORMS ON MONDAY. DRY AND COOL CONDITIONS WILL PREVAIL FOR THE MIDDLE PART OF NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 912 PM EDT SATURDAY STILL A FEW DIURNAL SHOWERS ALONG THE BLUE RIDGE BUT THEY ARE FADING FAST. WILL REMOVE POPS FOR THE REST OF THE EVENING...THEN INCREASE POPS TOWARDS SUNRISE AS LOW PRESSURE ENTERS THE TENNESSEE VALLEY. MINOR UPDATES TO OTHER GRIDS. PREVIOUS DISCUSSION... AS OF 300 PM EDT SATURDAY WEAK LOW LEVEL CONVERGENCE JUST SOUTH OF OUR FORECAST AREA HAS IGNITED A FEW SHOWERS AND ISOLATED STORMS. THE HRRR MODEL LIFTS THIS BOUNDARY SLIGHTLY NORTH. THIS COMBINED WITH A WEAK UPSLOPE FLOW MAY FIRE A FEW SHOWERS AND ISOLATED STORMS SOUTH OF HIGHWAY 58 THIS AFTERNOON AND EARLY THIS EVENING...THEREFORE KEPT A SMALL CHANCE FOR POPS IN THE FORECAST. ALL THE MODELS ARE IN GOOD AGREEMENT ON DEVELOPING A STRONG LOW LEVEL SOUTHEAST JET...TRANSPORTING MOISTURE INTO THE AREA OVERNIGHT. A FEW GUSTS OVER 30KTS WILL BE POSSIBLE IN SOUTHEAST WV/CLINCH RIVER VALLEY VA OVERNIGHT AND SUNDAY...BUT VALUES ARE BELOW GUIDANCE CRITERIA. PWATS INCREASE TO 2-3 STANDARD DEVIATIONS ABOVE AVERAGE BY SUNDAY MORNING AND THROUGH MUCH OF THE DAY SUNDAY. MEANWHILE...A LARGE AREA UVV LIFTS NORTH INTO OUR REGION TOWARD DAWN THEN EAST OVER ENTIRE AREA ON SUNDAY. THIS IS IN ADVANCE OF A NEGATIVELY TILTED UPPER TROF LIFTING THROUGH THE OHIO VALLEY SUNDAY WHICH ALSO GENERATES STRONG UPPER DIFFLUENCE. AS A RESULT...EXPECT MODERATE TO HEAVY RAIN TO FALL FOR SEVERAL HOURS...ESPECIALLY ALONG THE EAST SLOPES OF THE BLUE RIDGE. MORE INFORMATION ABOUT THE FLOODING POTENTIAL FROM THIS SYSTEM CAN BE FOUND IN THE HYDROLOGY SECTION. BOTTOM LINE...A FLOOD WATCH WILL BE POSTED FOR THE NW NC MOUNTAINS/FOOTHILLS AND SOUTHERN BLUE RIDGE OF VA. FUTURE SHIFTS MAY NEED TO EXPAND THIS NORTH AND EAST...IF HIGHER QPF TRENDS CONTINUE. CONTINUED TO GO BELOW GUIDANCE FOR HIGHS SUNDAY...WITH WEDGE IN PLACE AND WIDESPREAD CLOUDS AND PRECIPITATION. IN FACT...MANY AREAS IN THE WEDGE LIKELY SEE LITTLE...IF ANY...RECOVERY IN TEMPS. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... AS OF 335 PM EDT SATURDAY... HEAVIER RAINFALL ASSOCIATED WITH NORTHEASTWARD MOVING STRONGLY NEGATIVELY TILTED UPPER TROUGH AND ASSOCIATED WARM/WEDGE FRONT WILL MOVE INTO THE PIEDMONT THROUGH 06Z MON...THEN EAST OF THE CWA BETWEEN 06Z AND 12Z MON. ADDITIONAL RAINFALL OF 1/2 TO 3/4 INCH DURING THIS TIME FRAME SHOULD BE CONFINED TO THE PIEDMONT. FLOOD WATCH ENDS AT 04Z MON...WHICH SHOULD BE GOOD TIMING. MEANWHILE...A BROAD UPPER TROUGH CONTINUES TO DEEPEN ACROSS THE GREAT LAKES WITH UPPER FLOW REMAINING SOUTHWEST BEHIND THE AFOREMENTIONED UPPER TROUGH. THE NEXT UPPER SHORT WAVE WILL BE APPROACHING THE WESTERN AREAS BY DAYBREAK MONDAY WITH A STRONG COLD FRONT MOVING INTO THE WESTERN TN/OH VALLEY. SCATTERED SHOWERS SHOULD DEVELOP ONCE AGAIN ACROSS THE WESTERN MOUNTAINS IN ADVANCE OF THESE FEATURES. BY AFTERNOON...MUCH OF THE CWA...ESPECIALLY EAST OF THE BLUE RIDGE WILL BE SOLIDLY IN THE WARM SECTOR WITH TEMPERATURES ACROSS THE PIEDMONT NEAR 80 DEGREES AND DEWPOINTS NEAR 60. A 6-HOUR WINDOW OF SUBSTANTIAL CAPE IN EXCESS OF 1000 J/KG...BULK 0-6KM SHEAR OF 20-30KTS...LIS TO -6 ALONG THE VA/NC BORDER...AND SIG SVR PARMS GREATER THAN 20000 COMBINED WITH STRONG PVA AND YET ANOTHER NEGATIVELY TILTED SHORT WAVE STRONGLY SUPPORT THE SLIGHT RISK OUTLOOK FROM SPC EAST OF THE BLUE RIDGE MON AFTERNOON...WITH THE MARGINAL RISK FURTHER WEST INTO THE MOUNTAINS. MAIN CONCERNS WILL BE THUNDERSTORM WIND GUSTS AND HAIL WITH COLD AIR ALOFT ADVECTING INTO THE REGION. A FEW MORE DISCRETE CELLS COULD DEVELOP EAST OF THE FRONT ACROSS THE PIEDMONT IF MAXIMUM INSTABILITY/HEATING IS REALIZED. THE SEVERE THREAT WILL END QUICKLY FROM WEST TO EAST AFT 00Z AS THE THERMODYNAMICS WANE QUICKLY AND THE UPPER SUPPORT SHIFTS NORTHEAST OF THE REGION. RAINFALL WILL NOT BE A CONCERN WITH THIS SECOND EVENT AS ACTIVITY WILL BE BRIEF AND SCATTERED...BUT A QUICK 1/2 INCH OF RAIN MAY OCCUR IN AREAS WITH HEAVIER SHOWERS/THUNDERSTORMS. SCATTERED UPSLOPE RAIN SHOWERS COULD PERSIST ACROSS THE MOUNTAINS INTO TUESDAY...BUT NO SIGNIFICANT DYNAMICS ARE FORESEEN WITHIN THIS TIME FRAME. UNSEASONABLY WARM TEMPERATURES MONDAY WILL GIVE WAY TO MUCH COOLER CONDITIONS ACROSS THE MOUNTAINS TUESDAY WITH VARIABLE CLOUDS AND A FEW SHOWERS...BUT DOWNSLOPE PIEDMONT AREAS SHOULD STILL BE CLOSE TO 70 EVEN TUESDAY. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 350 PM EDT SATURDAY... MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE PIEDMONT. THE ECMWF HAS COME INTO BETTER AGREEMENT WITH THE GFS NOW ON A DISTURBANCE ROTATING THROUGH THE BOTTOM OF THE UPPER TROUGH WEDNESDAY...BRINGING A BETTER THREAT OF SHOWERS TO THE REGION. THUS...HAVE INCREASED POPS IN ACCORDANCE WITH THE BETTER MODEL AGREEMENT AND SURROUNDING OFFICES. HAVE NOT INTRODUCED THUNDER AT THIS POINT...BUT COULD NOT TOTALLY RULE OUT SOME THUNDER BECAUSE OF RATHER COLD AIR ALOFT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE CONCERN AT THIS POINT. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 145 AM EDT SUNDAY... MODELS CONTINUE TO BE CONSISTENT WITH CLOUDS AND THEN RAIN WILL SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT CEILINGS TO LOWER TO MVFR ON THE 09Z/5AM-16Z/11AM TIME RANGE. A STRONG SOUTHEAST LOW LEVEL JET WILL DEVELOP JUST AFTER MIDNIGHT WHICH MAY BRING WIND GUSTS TO 30 KTS TODAY. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM. A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO IFR LATE THIS AFTERNOON INTO THE EVENING AND WILL REMAIN LOW OVERNIGHT. EXTENDED AVIATION... A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS. THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY. && .HYDROLOGY... AS OF 330 PM EDT SATURDAY... ANTECEDENT CONDITIONS ARE STILL MOIST ACROSS THE NW NC MOUNTAINS/FOOTHILLS INTO THE SOUTHERN BLUE RIDGE OF VA WITH THE PERCENT OF NORMAL PRECIP OVER THE PAST WEEK EXCEEDING OVER 150%. THIS ALSO IS SHOWN IN RIVER STAGE LEVELS ACROSS THIS REGION FROM THE USGS WITH STREAM LEVELS IN MANY LOCATIONS RUNNING GREATER THAN THE 75TH PERCENTILE. WITH 6 HOUR FLASH FLOOD GUIDANCE VALUES BELOW 3 INCHES IN THE REGION...AND FORECAST PW VALUES 2-3 STANDARD DEVIATIONS ABOVE NORMAL...EXPECT FLOODING OF CREEKS AND STREAMS. WHILE THE SREF MODEL ENSEMBLE RIVER FORECAST ONLY IS FORECASTING A SMALL CHANCE FOR RIVERS TO REACH ACTION STAGE...WOULD NOT BE SURPRISED TO SEE A FEW SITES REACH MINOR FLOODING CONSIDERING THE MODEL TRENDS OF INCREASING QPF WITH EACH RUN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ015>017-032. NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020. WV...NONE. && $$ SYNOPSIS...PH NEAR TERM...PH/RCS SHORT TERM...RAB LONG TERM...RAB AVIATION...AMS/PC HYDROLOGY...PH
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND MONDAY ISSUED AT 327 AM CDT SUN APR 19 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS. TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT MUCH COOLER READINGS OVER EASTERN WI THOUGH. TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH. MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S NORTH TO LOW 50S SOUTH. .LONG TERM...MONDAY NIGHT THROUGH SATURDAY ISSUED AT 327 AM CDT SUN APR 19 2015 CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN WEDNESDAY MORNING. BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION CHANCES AND TEMPERATURES DURING THE PERIOD. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1014 PM CDT SAT APR 18 2015 CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH THE NIGHT AND EARLY SUNDAY MORNING AS LOW PRESSURE SYSTEMS APPROACH FROM THE WEST AND SOUTH. RAIN IS EXPECTED TO BEGIN LATER SUNDAY MORNING ACROSS THE WEST AND SUNDAY AFTERNOON ACROSS THE EASTERN TAF SITES. TIMING OF THE RAIN SHOWERS IS A BIT TENUOUS AS THERE REMAINS SIGNIFICANT DIFFERENCES BETWEEN THE NWP MODELS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ECKBERG AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1123 PM MDT SAT APR 18 2015 .UPDATE... ISSUED AT 1108 PM MDT SAT APR 18 2015 CLOUD TOPS CONTINUE TO WARM ON IR IMAGERY...AND THE BAND OF MODERATE SNOW HAS SHIFTED EAST MORE INTO CENTRAL/SOUTHERN ALBANY COUNTY AND WESTERN LARAMIE COUNTY...SO ALLOWED THE WINTER HIGHLIGHTS TO EXPIRE. UPDATE ISSUED AT 945 PM MDT SAT APR 18 2015 THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST TO CANCEL ALL WINTER HEADLINES AT THIS TIME. ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS THE FOG AROUND THROUGH 11PM-12AM. .UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015 TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR THE NEXT HOUR OR SO. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 440 PM MDT SAT APR 18 2015 LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS. THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN THE FORECAST AREA. SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE OVER THE NEXT FEW HOURS. ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY BE NEEDED EVENTUALLY. QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT. ACCUMULATIONS WILL BE MINIMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 250 PM MDT SAT APR 18 2015 MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER EAST DUE TO A PERSISTENT LLVL STRATUS DECK. MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30 PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY SATURDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) AREAS OF MVFR AND IFR CIGS WILL AFFECT MOST TERMINALS OVERNIGHT WITH SOME RAIN AND SNOW EARLY IN THE PERIOD. GUSTY SFC WINDS EXPECTED ESPECIALLY OVER THE PLAINS TONIGHT AND SUNDAY. CIGS IMPVG DURING THE DAY SUNDAY. && .FIRE WEATHER... ISSUED AT 250 PM MDT SAT APR 18 2015 SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS. WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT WEEK...MAYBE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...RJM SHORT TERM...SML LONG TERM...TJT AVIATION...RE FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1108 PM MDT SAT APR 18 2015 .UPDATE... ISSUED AT 1108 PM MDT SAT APR 18 2015 CLOUD TOPS CONTINUE TO WARM ON IR IMAGERY...AND THE BAND OF MODERATE SNOW HAS SHIFTED EAST MORE INTO CENTRAL/SOUTHERN ALBANY COUNTY AND WESTERN LARAMIE COUNTY...SO ALLOWED THE WINTER HIGHLIGHTS TO EXPIRE. UPDATE ISSUED AT 945 PM MDT SAT APR 18 2015 THE BAND OF MODERATE TO LOCALLY HEAVY SNOW CONTINUES TO SLOWLY SHIFT EAST THIS EVENING...BUT PERHAPS SLIGHTLY SLOWER THAN PREVIOUS THINKING. EARLIER ANALYSIS SUGGESTED A FEW STRONGER SNOW SHOWERS WERE PERSISTING FROM THE NORTHERN LARAMIE RANGE SOUTHWEST THROUGH THE ARLINGTON AREA AND ON UP INTO THE SNOWY RANGE AND SOUTHERNMOST AREAS OF THE SIERRA MADRE MOUNTAINS. SHORT TERM MODELS ALSO SUGGESTED THAT THE BAND WOULD MOVE SLOW TO THE EAST THIS EVENING... SO FELT IT PRUDENT TO EXTEND THE WINTER STORM WARNING AND ADVISORY FOR A FEW MORE HOURS AS SNOW WOULD CONTINUE TO IMPACT THESE LOCATIONS. ENDED THE HEADLINES AT 11PM AS IR IMAGERY IS SHOWING A RAPID WARMING OF CLOUD TOPS...AND MODELS SUGGEST THE BAND WILL HAVE WEAKENED AND SHIFTED ENOUGH TO THE EAST TO CANCEL ALL WINTER HEADLINES AT THIS TIME. ALSO...ADDED AREAS OF FOG TO THE SUMMIT THROUGH MIDNIGHT AS WEBCAMS SHOWED THE DEVELOPMENT OF FOG EARLIER...AND HRRR KEEPS THE FOG AROUND THROUGH 11PM-12AM. .UPDATE ISSUED AT 546 PM MDT SAT APR 18 2015 TORNADO WATCH HAS BEEN CANCELLED. CONDITIONS ARE NO LONGER FAVORABLE FOR TORNADO DEVELOPMENT IN THE SOUTHERN NEBRASKA PANHANDLE WITH THE BOUNDARY LAYER STABILIZING. A FEW THUNDERSTORMS AREA STILL POSSIBLE OVER THE NEXT FEW HOURS INTO SOUTHEAST WYOMING AND PANHANDLE BUT SEVERE WEATHER IS VERY UNLIKELY. A ROUGE FUNNEL CLOUD AND SMALL HAIL STILL POSSIBLE FOR THE NEXT HOUR OR SO. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 440 PM MDT SAT APR 18 2015 LOTS OF WEATHER CONCERNS OVER THE NEXT 12 HOURS. HEAVY SNOW CONTINUES IN A NARROW BAND...MAINLY ACROSS EASTERN/CENTRAL CARBON COUNTY...STRETCHING NORTHEAST INTO THE NORTHERN LARAMIE RANGE. ON EITHER SIDE OF THE HEAVY BAND...MAINLY LOOKING AT LIGHT NON ACCUMULATING SNOW OR RAIN. THIS WILL CONTINUE TO BE THE CASE UNTIL LATE THIS EVENING WHEN THE DEFORMATION AXIS BEGINS TO SHIFT EAST AS THE NORTHWEST FLOW KICKER PUSHES THE UPPER LOW INTO THE PLAINS. THE BAND WILL SHIFT EAST LATE THIS EVENING INTO THE OVERNIGHT HOURS BUT IT WILL ALSO WEAKEN SUBSTANTIAL WILL LITTLE IN THE WAY OF ADDITION MEASURABLE PRECIPITATION AFTER MIDNIGHT ANYWHERE IN THE FORECAST AREA. SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER THE PLAINS. A TORNADO WATCH IS IN EFFECT FOR MORRILL AND CHEYENNE COUNTY IN THE SOUTHERN NEBRASKA PANHANDLE UNTIL 8 PM MDT. BASED ON RADAR TRENDS AND CURRENT ATMOSPHERIC ENVIRONMENT...ANY TORNADO THREAT IS RAPIDLY DECREASING. CURRENT SHOWER ACTIVITY WILL RAPIDLY STABILIZE THE BOUNDARY LAYER. ALSO...LIMITED SHEAR IS ONLY SUPPORTIVE OFF VERY SHORT LIVED AND WEAK TORNADIC ACTIVITY. WOULD NOT BE SURPRISED TO SEE A FEW FUNNEL CLOUD REPORTS WITH DEVELOPING SHOWERS AND THUNDERSTORMS AS THE OVERALL ENVIRONMENT IS MORE SUPPORTIVE OF FUNNEL CLOUDS BUT THAT TOO WILL QUICKLY WANE OVER THE NEXT FEW HOURS. ANOTHER CONCERN FOR TONIGHT IS NORTHERN WINDS WHICH WILL RAMP UP THIS EVENING INTO THE OVERNIGHT AS A COLD FRONT MOVES ACROSS THE AREA. COULD SEE A SHORT PERIOD OF NASTY WINTER CONDITIONS...MAINLY INTO THE SOUTHERN LARAMIE RANGE AND CHEYENNE AS THE SNOW BAND SHIFTS EAST AND INTERACTS WITH STRONG GUSTY NORTHERN WINDS. NAM AND GFS BUFKIT SOUNDINGS AROUND MIDNIGHT SHOWING 45 TO 50 KT WINDS AT CHEYENNE NOT TOO FAR OFF THE SURFACE. VERY WELL COULD SEE A 3 TO 4 HOUR PERIOD WITH LOW VISIBILITIES DUE TO FALLING SNOW AND GUSTY WINDS. FORTUNATELY THIS WILL BE SHORT LIVED IF IT THIS COMBINATIONS DOES INDEED OCCUR. ALSO WINDS SPEEDS WILL APPROACH WIND ADVISORY LEVELS INTO THE NEBRASKA PANHANDLE LATER TONIGHT AND INTO SUNDAY AFTERNOON. DID NOT ISSUE ANY WIND HEADLINES GIVEN WINTER WEATHER AND CONVECTIVE HEADLINES...BUT A WIND ADVISORY MAY BE NEEDED EVENTUALLY. QUIETER WEATHER ACROSS THE AREA SUNDAY WITH THE UPPER LOW OUT OF THE PICTURE. KEPT SOME LOW POPS GOING ACROSS THE WEST DURING THE DAY SUNDAY...BUT IT IS LOOKING LESS AND LESS LIKELY FOR ANY MEASURABLE PRECIPITATION FOR MOST OF SUNDAY. MAIN CHANCES WILL BE WITH NORTHERN STREAM SHORTWAVE AND UPPER LEVEL JET ENERGY WHICH SHOULD IMPACT THE SNOWY AND SIERRA MADRES SUNDAY NIGHT. ACCUMULATIONS WILL BE MINIMAL. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 250 PM MDT SAT APR 18 2015 MEDIUM TO LONG RANGE MODELS IN FAIR AGREEMENT THROUGH THE MIDDLE OF NEXT WEEK...WITH SOME DISAGREEMENT REGARDING THE TRACK AND EVOLUTION OF A DEVELOPING LOW PRESSURE SYSTEM LIFTING NORTHEAST ACROSS THE CENTRAL AND SOUTHERN ROCKY MOUNTAINS BY THURSDAY AND FRIDAY. FOR EARLY NEXT WEEK...ALL MODELS SHOW NORTHWEST FLOW INITIALLY WITH RELATIVELY DRY CONDITIONS LASTING INTO EARLY WEDNESDAY. A WEAK SHORTWAVE TROUGH WILL PUSH ACROSS THE REGION EMBEDDED IN THE NORTHWEST FLOW...BUT OUTSIDE OF SOME MOUNTAIN/HIGH VALLEY RAIN AND SNOW SHOWERS...DO NOT EXPECT ANYTHING SIGNIFICANT WITH HIGH TEMPERATURES ABOUT 10 TO 15 DEGREES COOLER THAN SEASONAL AVERAGES. TEMPERATURES WILL FINALLY MODERATE SOME BY TUES AND ESPECIALLY INTO WED...BACK INTO THE UPPER 50S TO UPPER 60S TO THE EAST OF THE LARAMIE RANGE. A SURFACE HIGH WILL BUILD OVER THE GREAT PLAINS LATE WEDNESDAY AND ON THURSDAY...RESULTING IN WINDS VEERING INTO THE EAST AND SOUTHEAST. KEPT TSTORMS IN THE FORECAST FOR THURSDAY WEST OF THE LARAMIE RANGE...BUT KEPT SHOWERS FURTHER EAST DUE TO A PERSISTENT LLVL STRATUS DECK. MODELS STRUGGLING WITH A SHORTWAVE DISTURBANCE LIFTING NORTHEAST OUT OF ARIZONA THURSDAY NIGHT. 12Z GFS ATTEMPTS TO FORM A CLOSED LOW ACROSS THE NORTH CENTRAL PLAINS OF COLORADO BY EARLY FRIDAY...WITH PRECIP EXTENDING INTO THE I80 CORRIDOR OF SOUTHEAST WYOMING AND WESTERN NEBRASKA. THE ECMWF ON THE OTHER HAND IS MUCH FURTHER SOUTH...MAINLY SHOWING THE FEATURE ACROSS NORTHERN NEW MEXICO LIFTING NORTHEAST INTO KANSAS BY FRIDAY. KEPT A 20 TO 30 PERCENT CHANCE OF RAIN AND HIGH ELEVATION SNOW FOR FRIDAY AND EARLY SATURDAY MORNING. && .AVIATION...(FOR THE 00Z TAFS THROUGH SUNDAY AFTERNOON) A BAND OF SNOW AND RAIN WILL REMAIN OVER CONVERSE...CARBON...AND ALBANY COUNTIES THIS EVENING...AND THEN WILL RAPIDLY PUSH SOUTHEAST NEAR A COLD FRONT...WHICH WILL PUSH SOUTHWARD TONIGHT. SCATTERED TSTORMS HAVE DEVELOPED NEAR KSNY AND JUST EAST OF KCYS THIS AFTERNOON. THESE TSTORMS WILL GRADUALLY MOVE NORTHWEST THIS AFTERNOON AND THIS EVENING. SMALL HAIL AND BRIEF HEAVY RAINFALL IS EXPECTED. A MORE STABLE AIRMASS WILL PUSH INTO THE REGION ON SUNDAY BEHIND A WEAK COLD FRONT...RESULTING IN LOW PRECIPITATION CHANCES ACROSS MOST OF THE FORECAST AREA. HOWEVER...IT WILL BE WINDY BEHIND THIS FRONT WITH NORTH WINDS BETWEEN 20 TO 30 KNOTS EAST OF THE LARAMIE RANGE. && .FIRE WEATHER... ISSUED AT 250 PM MDT SAT APR 18 2015 SHOWERS AND THUNDERSTORMS WILL END ACROSS ACROSS THE PLAINS TONIGHT WITH SNOW ENDING OVER HIGHER ELEVATIONS OF WYOMING AS THE UPPER LEVEL DISTURBANCE SHIFTS EAST INTO THE CENTRAL PLAINS. WARMING TREND THROUGH MID WEEK BUT GENERALLY ON THE COOLER SIDE AND DRY. NEXT CHANCE FOR WIDESPREAD PRECIPITATION IS LATE NEXT WEEK...MAYBE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...RJM SHORT TERM...SML LONG TERM...TJT AVIATION...TJT FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
901 AM EDT SUN APR 19 2015 ...INCREASING POTENTIAL FOR STRONG/SEVERE STORMS THIS AFTERNOON... .UPDATE... INTERESTING ENVIRONMENTAL SETUP FOR THIS AFTERNOON IN OUR AREA. INITIAL PRECIPITATION AREA EXITING TO NORTHEAST WITH INITIAL SHORTWAVE SEEN ON WATER VAPOR IMAGERY. VISIBLE IMAGERY SHOWING AREA OF CLEARING...JUST SOME HIGH CLOUDS...SOUTHWEST GA/NW AND WCTRL FL WHICH WILL SHIFT EASTWARD AHEAD OF DEVELOPING CONVECTION OVER GULF OF MEX. THUS SHOULD ALLOW SURFACE TEMPS TO RISE INTO 80-85 RANGE ACROSS FCST AREA...DESTABILIZING AIRMASS. GENERALLY FOLLOWING THE HRRR...ANTICIPATE INCREASE/UPSCALE IN CONVECTION W OF FORECAST AREA INTO NRN GULF THROUGH THE MORNING APPROACHING OUR WRN COUNTIES TOWARD 18Z...AHEAD OF A WELL-DEFINED SHORTWAVE SEEN ON WATER VAPOR. MODELS BRING SHORT WAVE OVER OUR FORECAST AREA LATE THIS AFTERNOON. MEANWHILE...MORNING SOUNDINGS SUGGEST POTENTIAL FOR EAST COAST SEA BREEZE TO MAKE SOME PROGRESS INLAND...PERHAPS TO I-95 CORRIDOR MID AFTERNOON WHILE WEST COAST SEA BREEZE MOVES EASTWARD DURING AFTERNOON. LATEST HRRR SUGGESTS TWO AREAS OF CONCERN...FIRST IS AN ORGANIZED LINE...OR LINE SEGMENTS...MOVING NORTHEAST ACROSS OUR WESTERN COUNTIES 18Z-21Z...AND EASTERN COUNTIES 21Z-00Z. PRIMARY THREAT WILL BE LOCALLY SEVERE WINDS WITH BOWING SEGMENTS GIVEN UNSTABLE AIRMASS AND DECENT LOW-LEVEL LAPSE RATES. FEEL THE BEST POTENTIAL FOR SEVERE WEATHER FROM THIS PORTION WILL BE SUWANNEE VALLEY REGION OF NE FL...AND MUCH OF SE GA. SUFFICIENT LOW-LEVEL SHEAR/HELICITY SUCH THAT ISOLATED TORNADOES WILL BE POSSIBLE. A TORNADO WATCH IS ISSUED WEST OF OUR AREA...AND WOULD ANTICIPATE EASTWARD EXPANSION THIS AFTERNOON. HRRR SUGGESTS WEAKENING OF THIS ACTIVITY AS IT MOVES EAST OVER OUR FORECAST AREA...BUT UNCERTAIN OF THIS SOLUTION GIVEN WELL DEFINED SHORT WAVE AND DIFFLUENCE IN RIGHT-REAR QUAD SUPPORTING CONVECTION. A SECOND AREA OF CONCERN IS ASSOCIATED WITH EASTWARD MOVING WEST COAST SEA BREEZE...WHICH HRRR SUGGESTS COULD INITIATE DISCRETE CELLULAR CONVECTION AFTER 18Z OVER EASTERN PORTION OF NE FL... PARTICULARLY LATER IN AFTERNOON AS IT CONVERGES WITH EAST COAST SEA BREEZE. COMBINATION OF CAPE VALUES 2000-3000 J/KG AND DEEP LAYER SHEAR VALUES NEAR 40KTS SUGGEST SOME SUPERCELL STRUCTURES POSSIBLE...WITH POTENTIAL FOR ISOLATED STRONG/SEVERE STORMS. PRIMARY THREAT HERE WOULD BE STRONG WINDS AND HAIL...BUT CANNOT RULE OUT ISOLATED TORNADO ESPECIALLY FAR EASTERN COUNTIES IF FLOW IS BACKED NEAR EAST COAST SEA BREEZE. && .AVIATION...VFR CONDITIONS THRU EARLY AFTERNOON...WITH POTENTIAL FOR MVFR CONDITIONS ASSOCIATED WITH SCATTERED TO NUMEROUS TSRA. && .MARINE...NO SIGNIFICANT CHANGES PLANNED IN NEXT CWF ISSUANCE. WINDS WILL BECOME SOUTH TODAY WITH 2-4 FT SEAS. SHOWERS/T-STORMS WILL INCREASE DURING THE AFTERNOON INTO THE EARLY EVENING HOURS. RIP CURRENTS: MODERATE RISK TODAY DUE TO LINGERING SWELL. && .PRELIMINARY POINT TEMPS/POPS... AMG 82 65 82 58 / 80 30 30 20 SSI 79 68 81 64 / 80 30 30 20 JAX 84 67 84 62 / 80 30 30 20 SGJ 82 68 82 65 / 70 30 40 20 GNV 85 67 83 64 / 70 20 40 20 OCF 86 67 83 65 / 60 20 40 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ WOLF/SANDRIK/WALKER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1121 AM EDT SUN APR 19 2015 .SYNOPSIS... A WARM FRONT WILL LIFT INTO THE AREA TODAY...ACCOMPANIED BY AN UPPER LEVEL DISTURBANCE. A COLD FRONT WILL APPROACH THE AREA MONDAY... MOVING OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN TUESDAY THROUGH THURSDAY. A WEAK COLD FRONT WILL DROP THROUGH THE AREA THURSDAY NIGHT...THEN A STORM SYSTEM WILL AFFECT THE REGION NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATE THIS MORNING...THE WARM FRONT PRECIPITATION THAT HAD BLOSSOMED EARLIER THIS MORNING ACROSS SOUTHEAST GEORGIA HAS DISSIPATED PRETTY RAPIDLY AS IT LIFTS TO THE NORTHEAST. AS SUCH...THE REST OF THE MORNING WILL BE RELATIVELY QUIET AHEAD OF THE MAIN FORECAST PROBLEM WHICH IS THE LARGE AREA OF CONVECTION CURRENTLY IMPACTING MUCH OF ALABAMA/GEORGIA/FLORIDA. OVERALL...THERE WILL BE LIMITED PRECIPITATION COVERAGE OUT AHEAD OF THE APPROACHING LINE OTHER THAN SCATTERED DISCRETE SHOWERS/THUNDERSTORMS THAT SHOULD DEVELOP RIGHT AS THE LINE PUSHES INTO THE WESTERN ZONES. CURRENTLY...THE RECENT RUNS OF THE HRRR SEEMS TO HAVE AN EXCELLENT HANDLE ON THE POSITION OF THE CONVECTION AND ITS AFTERNOON PROGRESSION SEEMS QUITE REASONABLE. REGARDING TIMING...THE HRRR IS RUNNING ABOUT AN HOUR OR TWO ON THE SLOW SIDE SO WE THINK THE LINE OF STORMS WILL BEGIN IMPACTING THE WESTERN ZONES IN THE 1-2PM WINDOW. THIS WOULD PUT THE LINE INTO THE SAVANNAH METRO AREA 3-5PM AND THEN THE CHARLESTON REGION BETWEEN 6-8PM. THE POTENTIAL FOR SEVERE WEATHER APPEARS TO BE INCREASING. UPSTREAM OFFICES HAVE BEEN ISSUING A MIXTURE OF SEVERE/TORNADO WARNINGS THIS MORNING WITH A NUMBER OF WIND DAMAGE REPORTS. BASED ON ITS LOCATION RELATIVE TO THE LINE AT 12Z...THE TAE MORNING SOUNDING IS LIKELY THE BEST SAMPLING OF THE APPROACHING NEAR STORM ENVIRONMENT. AS SUCH...WE EXPECT A STRONGLY SHEARED ENVIRONMENT WITH A NICE VEERING OF THE LOW LEVEL PROFILE AND CAPE VALUES INCREASING INTO THE 1500-2000 J/KG RANGE. IN FACT...THE TAE SOUNDING HAS A DISTINCT ELEVATED MIXED LAYER THAT ACTUALLY SHOWS UP WELL WHEN LOOKING AT HRRR SOUNDINGS LATER THIS AFTERNOON. ONE OF THE MORE TROUBLING ASPECTS IS THE POTENTIAL FOR A WINDOW OF CLEARING NOTED ON VISIBLE SATELLITE IMAGERY. AS THIS CLEARING HAS MOVED ACROSS SOUTH GEORGIA TEMPERATURES HAVE RISEN INTO THE UPPER 70S AND EVEN TO 80 WITHIN JUST AN HOUR. GIVEN LOW LEVEL THICKNESS VALUES AS THEY ARE...EVEN A BRIEF PERIOD OF SUN WILL LEAD TO A RAPID WARM UP AND INCREASE THE SURFACE DESTABILIZATION POTENTIAL. SO USING THE HRRR AND ITS SOUNDINGS AS THE BEST REPRESENTATION OF THE AFTERNOON NEAR STORM ENVIRONMENT...IT APPEARS WE ARE LOOKING AT CAPE VALUES AS HIGH AS 2500 J/KG...0-3 KM SHEAR OF 30-35 KT...AND SRH VALUES BETWEEN 150-250 THANKS TO THE SOUTHEAST BACKED LOW LEVEL FLOW. SUCH AN ENVIRONMENT WILL LIKELY FAVOR A CONVECTIVE MODE OF LINEAR SEGMENTS WITH EMBEDDED SUPERCELL ELEMENTS AND EVEN THE POTENTIAL FOR A DISCRETE SUPERCELL OR TWO. DAMAGING WIND GUSTS CONTINUES TO BE THE PRIMARY SEVERE WEATHER THREAT...BUT THE SHEAR AND LOW LEVEL VEERING WILL ALSO PROVIDE A TORNADO THREAT AS WELL. MUCH WILL BE DETERMINED BY HOW MUCH SUN CAN BREAK THROUGH AND TEMPERATURES WARM. ONE OTHER POTENTIAL THING TO WATCH IS THAT THE CURRENT SOUTHEAST WINDS COULD ADVECT IN A SLIGHTLY MORE STABLE MARINE ENVIRONMENT. HOWEVER...GIVEN THAT WE ARE OUT OF THE COOLEST SHELF WATER SEASON THIS IMPACT IS EXPECTED TO BE LIMITED. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... TONIGHT...THE SHORTWAVE WILL PUSH OFF THE COAST AND ELEVATED POPS DURING THE EVENING HOURS SHOULD DECREASE BELOW 15 PERCENT AS SOMEWHAT DRIER AIR AND TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO EARLY MONDAY. ANOTHER IN A SERIES OF VERY MILD OVERNIGHTS WITH TEMPS ONLY FALLING TO THE MID 60S ONCE AGAIN. THE LONGWAVE TROUGH WILL PERSIST TO OUR WEST ON MONDAY WHILE A SERIES OF POTENT SHORTWAVES LIFT NORTHEAST THROUGH THE LOCAL FORECAST AREA. A 145 KT SOUTHERN STREAM JET STREAK IS PROGGED TO SLIDE ALONG THE CENTRAL GULF COAST REGION DURING THE DAY...SPREADING A REGION OF ENHANCED UPPER LEVEL DIVERGENCE INTO SC/GA IN THE AFTERNOON. MODEL TIME SECTIONS SHOW CONSIDERABLE DRYING ABOVE 850 MB EARLY IN THE PERIOD...WITH PWATS DROPPING BELOW 1.25" BY MONDAY AFTERNOON. THE MAIN COLD FRONT WILL SLOWLY MOVE EAST DURING THE DAY...CROSSING THE REGION AT SOME POINT MONDAY EVENING. GIVEN THE DRY AIR ALOFT... CONSIDERABLE BREAKS IN THE CLOUDS AND COMPRESSIONAL HEATING AHEAD OF THE FRONT SHOULD HELP PUSH TEMPS INTO THE MID/UPPER 80S. THE BIG QUESTION ON MONDAY IS HOW MUCH CONVECTIVE COVERAGE DEVELOPS. THE DEEP DRY LAYER ABOVE THE SURFACE MAY LIMIT THE INITIAL CONVECTIVE DEVELOPMENT. HOWEVER...MODELS ARE HINTING AT AN UPSTREAM CONVECTIVE CLUSTER MOVING INTO WESTERN AREAS LATER IN THE AFTERNOON. THERMODYNAMICS AND KINEMATICS ARE QUITE IMPRESSIVE ON MONDAY. 40-50 KT OF 0-6 KM BULK SHEAR...CAPES OF 1500-2000 J/KG AND DOWNDRAFT CAPES 1000 TO 1500 J/KG. A FAIRLY ROBUST SEA BREEZE IS EXPECTED TO DEVELOP IN THE AFTERNOON GIVEN SUCH WARM TEMPS INLAND AND PREVAILING SOUTHERLY FLOW. THIS MAY COME INTO PLAY LATE IN THE DAY IF UPSTREAM CONVECTION MOVES IN FROM THE WEST. GIVEN THE SOMEWHAT DRIER TREND IN THE LATEST MODELS...WE MINIMIZED POPS MONDAY MORNING WITH VALUES INCREASING TO 30-40% IN THE AFTERNOON...ESPECIALLY ACROSS INTERIOR SC/GA. AS THE ACTIVITY AHEAD OF THE FRONT MOVES THROUGH OUR AREA IT SHOULD BE GRADUALLY WEAKENING. THEN SOME ADDITIONAL ACTIVITY...LIKELY WEAKER...COULD ACCOMPANY THE ACTUAL FRONT LATER IN THE EVENING OR OVERNIGHT. WE PLAN TO MAINTAIN SEVERE WEATHER POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT WITH DRY WEATHER AND SEASONABLE TEMPERATURES TUESDAY AND WEDNESDAY. HIGHS WILL CLIMB TO NEAR 80 BOTH DAYS WITH OVERNIGHT LOWS IN THE MID 50S. && .LONG TERM /MONDAY THROUGH SATURDAY/... A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT. PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER AND WEAK COLD ADVECTION. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... DEEP MOISTURE ACROSS THE TAF CORRIDOR TODAY. LAYERED CLOUDS THIS MORNING DIFFICULT TO PIN DOWN AS RECENTLY LOW STRATUS DECKS DEVELOPED IN THE WARM FRONTAL ZONE DEVELOPING ACROSS THE REGION. MODELS INDICATE THAT IFR/LIFR CIGS AND IFR VSBYS SHOULD BE CONFINED TO THE MORNING HOURS WITH MVFR TO VFR CIGS DEVELOPING IN A BIT OF A DRIER SLOT THIS AFTERNOON AHEAD OF CONVECTION THAT SHOULD SWEEP THROUGH THE TERMINALS IN THE 19Z TO 00Z TIME FRAME. TSTMS ARE POSSIBLE WITH HEAVY DOWNPOURS AND PERHAPS GUSTY AND SHIFTING WINDS. MAINLY VFR TONIGHT BUT MVFR/IFR CIGS ARE POSSIBLE LATE. EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED AT BOTH TERMINALS MONDAY AFTERNOON AND EVENING WITH BRIEF MVFR CEILING/VSBY RESTRICTIONS POSSIBLE. OTHERWISE VFR CONDITIONS EXPECTED. && .MARINE... A WARM FRONT WILL LIFT THROUGH THE WATERS TODAY...FOLLOWED BY INTENSIFYING SOUTH/SOUTHWEST FLOW. LIGHT AND VARIABLE WINDS EARLY THIS MORNING WILL BECOME SE PRIOR TO THE WARM FRONT WHICH WILL SHIFT FLOW SW TO S TONIGHT. WHILE SPEEDS INCREASE TONIGHT AND SEAS SLOWLY BUILD...THE AVERAGE SPEED COULD REACH ONLY 15 KT BY DAYBREAK OVER NEAR SHORE WATERS WITH SEAS 3 TO 4 FT. THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE WATERS THIS AFTERNOON EVENING. VERY HEAVY DOWNPOURS REDUCING LOCAL VSBYS BELOW 1 NM ARE ALSO POSSIBLE WITH THE STRONGEST STORMS MOVING OFFSHORE LATE IN THE DAY AND EARLY THIS EVENING. A PREVAILING SSW FLOW WILL EXIST MONDAY MORNING AS A COLD FRONT APPROACHES FROM THE WEST. THE GRADIENT WILL STRENGTHEN DURING THE AFTERNOON...ESPECIALLY ALONG THE COAST WHERE A STRONG SEA BREEZE DEVELOPS DUE TO MID/UPPER 80S TEMPS OVER LAND. THE LATEST GFS AND NAM MOS AT FOLLY BEACH SC SHOW SFC WINDS EXCEEDING 20 KT LATE MONDAY AFTERNOON WHEN THE SEA BREEZE IS STRONGEST. THIS SEEMS FAIRLY REASONABLE GIVEN THE PATTERN AND THE WARMER INLAND TEMPS EXPECTED. A SMALL CRAFT ADVISORY MAY EVENTUALLY BE REQUIRED FOR CHARLESTON HARBOR MONDAY AFTERNOON FOR WINDS/GUSTS IN THE 20-30 KT RANGE. A BRIEF PERIOD OF SMALL CRAFT ADVISORY CONDITIONS MAY DEVELOP OVER OFFSHORE WATERS MONDAY NIGHT AS THE COLD FRONT MOVES THROUGH AND WINDS GUST TO 25 KT WITH SOME 6 FT SEAS ALSO POSSIBLE. TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH PRESSURE PREVAILS. && .TIDES/COASTAL FLOODING... THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ NEAR TERM...BSH SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...JRL TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
952 AM CDT SUN APR 19 2015 .UPDATE... 952 AM CDT I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES. WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I RAISED HIGH TEMPERATURES TODAY. KJB && .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO 20KT THRU MIDDAY. * WEST WINDS GUSTING TO 20 KT TOMORROW. * RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR VSBY IS PSBL UNDER HEAVIER SHOWERS. * LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z THRU DAYBREAK MON. JEE //DISCUSSION...UPDATED 12Z... EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN. CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM-HIGH CONFIDENCE IN RAIN TIMING AND COVERAGE. * MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z. * HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY IFR...MEDIUM CONFIDENCE IN TIMING. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
856 AM CDT SUN APR 19 2015 .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO 20KT THRU MIDDAY. * WEST WINDS GUSTING TO 20 KT TOMORROW. * RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR VSBY IS PSBL UNDER HEAVIER SHOWERS. * LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z THRU DAYBREAK MON. JEE //DISCUSSION...UPDATED 12Z... EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN. CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 14Z... * MEDIUM-HIGH CONFIDENCE IN RAIN TIMING AND COVERAGE. * MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z. * HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY IFR...MEDIUM CONFIDENCE IN TIMING. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
647 AM CDT SUN APR 19 2015 .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * EAST WINDS BETWEEN 7-12KT INCREASING TO 12-15KT WITH GUSTS UP TO 20KT THRU MIDDAY. * WINDS TURN NORTH LATE TONIGHT...THEN NORTHWEST EARLY MON. * RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. * LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z THRU DAYBREAK MON. BEACHLER //DISCUSSION...UPDATED 12Z... EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN. CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 12Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 18Z...MEDIUM CONFIDENCE IN WIND DIR/SPEED AFT 18Z. * MEDIUM CONFIDENCE IN PRECIP TIMING/COVERAGE. * HIGH CONFIDENCE IN CIGS DIMINISHING TO AT LEAST MVFR CONDS AFT 21Z...AND MEDIUM CONFIDENCE IN CIGS BECOMING IFR AFT 3Z MON. BEACHLER //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
642 AM CDT SUN APR 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 328 AM CDT SUN APR 19 2015 LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER, SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING, THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO ARRIVE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 328 AM CDT SUN APR 19 2015 LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS. MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING. SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE 500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE UPPER 30S AND LOWER 40S. 00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY: HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY. ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY, WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 542 AM CDT SUN APR 19 2015 MID AND HIGH CLOUDS WILL CONTINUE OVER THE AREA THIS MORNING, EFFECTING ALL TAF SITES UNTIL THE PCPN MOVES INTO THE SITES. WILL START ALL SITES WITH VCSH AS THE PCPN MOVES NORTHWARD AND INITIALLY SATURATES THE LOWER LEVELS, DURING THE MORNING HOURS. THEN BETWEEN 10AM AND NOON, PCPN WILL BECOME MORE DOMINATE AND STEADY. TIMING OF ONSET OF PCPN WAS TAKEN FROM A BLEND OF THE BUFKIT DATA, NAM12, HRRR, AND RADAR TRENDS. MVFR CIGS AND VIS WILL ARRIVE WITH THE RAIN AND CONTINUE THROUGH REST OF TAF VALID PERIOD. PCPN COULD LET UP SOME LATE THIS EVENING, SO HAVE ADDED ANOTHER LINE FOR VCSH AFTER THE BULK OF THE RAIN MOVES THROUGH, AND BEFORE THE NEXT BATCH ARRIVES LATE TONIGHT/EARLY TOMORROW MORNING. WINDS WILL BE EASTERLY TO START, BUT THEN BECOME SOUTHEASTERLY AS THE SYSTEM GET CLOSER TO THE SITES. WITH THE SURFACE LOW PRESSURE AREA MOVING RIGHT OVER THE TAFS, WINDS WILL BE VARIABLE, ENDING AT WEST TO SOUTHWEST LATER TONIGHT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...BARNES AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
733 AM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 730 AM CDT SUN APR 19 2015 SCATTERED SHOWERS CONTINUE TO DEVELOP AND MOVE GENERALLY IN A NORTHWARD DIRECTION...AND WERE MAINLY WEST OF A MACOMB IL TO MANCHESTER IA LINE. THESE SHOWERS WERE OCCURRING IN THE AXIS OF THE BETTER 850 MB MOISTURE TRANSPORT AND PRECIPITABLE WATERS OVER AN INCH. ELSEWHERE...LOW PRESSURE WAS ORGANIZING IN THE LOWER MS VALLEY AND A BROAD AREA OF PRESSURE FALLS WAS NOTED TO THE NORTH INDICATING LARGE SCALE ASCENT/WARM AIR ADVECTION WAS INCREASING. ALSO PRESSURE FALLS WERE OCCURRING IN THE UPPER MS VALLEY IN ASSOCIATION WITH THE DIGGING NORTHERN STREAM TROUGH. REGIONAL DOPPLER RADARS WERE SHOWING THE LEADING EDGE OF A RATHER LARGE AREA OF RAIN/ISOLATED THUNDERSTORMS FROM THE MO OZARKS AND SOUTHERN IL...MOVING NORTHWARD. THE HRRR MESO MODEL HAS CAPTURED THIS RAIN AREA WITH THE LEADING EDGE REACHING MACOMB BY NOON...THE QUAD CITIES BY EARLY AFTERNOON AND DUBUQUE/FREEPORT BY LATE AFTERNOON. THEREFORE...WIDESPREAD RAIN APPEARS LIKELY THIS AFTERNOON AND CONTINUING TONIGHT...WHICH THE CURRENT GRIDS DEPICT. && .SYNOPSIS... ISSUED AT 345 AM CDT SUN APR 19 2015 MODELS CONTINUE TO STRUGGLE WITH THE EASTERLY FEED OF DRY AIR INTO OUR NORTHEAST CWA AND AT SOME LOCATIONS DEWPOINTS WERE 10 DEGREES LOWER THAN ANY GUIDANCE. IN OUR WESTERN CWA GUIDANCE WAS CLOSE TO REALITY AS WINDS WERE MORE SOUTHEAST. SPC MESO ANALYSIS SHOWED DECENT 850 MB MOISTURE TRANSPORT ALONG WITH PRECIPITABLE WATERS OVER AN INCH IN OUR WESTERN CWA. AND SURE ENOUGH DOPPLER RADAR HAS SHOWN POCKETS OF SHOWERS AND ISOLATED THUNDERSTORMS ALL NIGHT. RAINFALL ESTIMATES INDICATE 1/4 TO 3/4 OF AN INCH HAS FALLEN IN SOME SPOTS IN OUR WEST SINCE LAST EVENING. 3 AM TEMPERATURES RANGED FROM 50 AT FREEPORT TO 61 AT MACOMB. ELSEWHERE...CANADIAN HIGH PRESSURE WAS CENTERED NORTHEAST OF LAKE SUPERIOR AND SOME SITES IN NW WI WERE REPORTING DEWPOINTS IN THE TEENS. UPPER LEVEL TROUGH WAS DIGGING INTO THE NORTHERN PLAINS WHILE ANOTHER TROUGH WAS PUSHING INTO THE CENTRAL/SOUTHERN PLAINS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 345 AM CDT SUN APR 19 2015 FORECAST FOCUS ON INCREASING RAIN AND TEMPERATURES. TODAY...UPPER LEVEL TROUGH APPROACHES FROM THE WEST AND THIS WILL PROVIDE LARGE SCALE ASCENT ALONG WITH BETTER MOISTURE TRANSPORT AS THE DAY PROGRESSES. THE MORE WIDESPREAD RAIN APPEARS TO DEVELOP THIS AFTERNOON WITH THE ARRIVAL OF STRONGER FORCING...AS A SHORT WAVE PUSHES ACROSS IA AHEAD OF THE MAIN TROUGH. MEANWHILE...PHASING BEGINS TO OCCUR AND MODELS LIFT A DEEPENING CYCLONE OUT OF THE LOWER MS VALLEY INTO FAR WESTERN INDIANA BY 00Z. INTERESTING THAT THE NAM/ECMWF KEEP NW IL DRY MUCH OF THE DAY AND THEY MAY BE ON TO SOMETHING WITH SUCH A DRY EASTERLY FEED INTO THAT AREA. I WILL MENTION ISOLATED THUNDERSTORMS THIS AFTERNOON AS DEEP LAYER SHEAR IS WEAK AND MUCAPE IS 500 J/KG OR LESS. WITH MORE CLOUDINESS TODAY MAXIMUM TEMPERATURES SHOULD BE COOLER THAN THAN THE PAST COUPLE OF DAYS. I AM EXPECTING HIGHS IN THE UPPER 60S TO LOWER 70S AT MOST LOCATIONS. TONIGHT...PHASING IS NEARLY COMPLETE AND A LONG WAVE TROUGH PUSHES ACROSS THE MIDWEST WITH DECENT FORCING AND GOOD MOISTURE IN PLACE. IN THE MEANTIME...THE SLOWLY DEEPENING CYCLONE LIFTS INTO NORTHERN LOWER MI BY 12Z. MODELS INDICATE WIDESPREAD RAIN OVER THE CWA MUCH OF THE NIGHT. THIS LOOKS TO BE MORE OF A STRATIFORM/DEFORMATION TYPE RAIN RATHER THAN ALL OUT CONVECTIVE/MCS TYPE SO WILL NOT MENTION THUNDER AS INSTABILITY IS VERY LIMITED...AND THE ENTIRE COLUMN IS VERY SATURATED. A COLD FRONT WILL PUSH ACROSS THE CWA DURING THE NIGHT USHERING MUCH COOLER TEMPERATURES INTO THE AREA BY MORNING. MINIMUM TEMPERATURES WILL RANGE FROM THE LOWER 40S AT INDEPENDENCE TO THE UPPER 40S AT PRINCETON AND MACOMB IN ILLINOIS. RAINFALL AMOUNTS TODAY THROUGH TONIGHT SHOULD BE 0.3 TO 0.7 INCHES OVER MUCH OF THE CWA. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 345 AM CDT SUN APR 19 2015 COOLER AND MAINLY DRY FOR MUCH OF UPCOMING WEEK WITH FROST/FREEZE POTENTIAL LATER IN THE WEEK. MUCH OF THE UPCOMING WEEK AHEAD WILL FEATURE A LARGE AND SLOW MOVING UPPER LOW FROM THE GREAT LAKES TO EASTERN CANADA DUE TO HIGHLY AMPLIFIED RIDGING OVER THE EASTERN ATLANTIC AND GREENLAND. OUR CWA WILL BE GOVERNED BY NORTHWEST FLOW ON BACKSIDE OF THE LARGE UPPER LOW WHICH WILL USHER IN REINFORCING BOUTS OF CANADIAN AIR RESULTING IN COOLER HIGHS IN THE 50S AND 60S... WITH LOWS MAINLY IN THE 30S. THE COOLER AIR WILL ALSO BE ACCOMPANIED BY WINDY CONDITIONS MONDAY AND TUESDAY WITH THE POTENTIAL TO BE NEAR WIND ADVISORY CRITERIA GIVEN JUXTAPOSITION OF TIGHT PRESSURE GRADIENT... COLD ADVECTION AND DEEP MIXING. AFTER SOME LINGERING SHOWERS POSSIBLE EARLY MONDAY AM... WILL HAVE THE POTENTIAL FOR AFTERNOON POPCORN SHOWERS ACROSS MAINLY THE NORTHERN CWA BOTH MONDAY AND TUESDAY WITH STEEP MID LEVEL LAPSE RATES... COLD AIR ALOFT... AND SKINNY CAPE NOTED ON FORECAST SOUNDINGS. WILL NEED TO WATCH FOR ENHANCED WIND GUSTS WITH ANY SHOWERS VIA EVAPORATIVE COOLING OF PCPN IN LARGE... DRY SUB-CLOUD LAYER WITH CLASSIC INVERTED V SOUNDINGS. CANADIAN SURFACE RIDGE AXIS BUILDING IN THURSDAY INTO FRIDAY WILL BRING POTENTIAL FOR FROST AND POSSIBLY FREEZING TEMPS ONE OR BOTH MORNINGS. MIN TEMPS MAY NEED LOWERING BY 3-5 DEGS SOME LOCATIONS ESPECIALLY THURSDAY AM BASED ON 850 MB TEMPS -4C TO -7C WITH MORE WIDESPREAD 20S POSSIBLE WITH ANY DURATION OF CLEAR SKIES AND LIGHT WINDS. RAIN CHANCES LOOK TO RETURN BY EITHER LATE IN THE WEEK AND/OR NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 730 AM CDT SUN APR 19 2015 VFR CONDS BECOMING MVFR/LCL IFR CONDS. SCATTERED SHOWERS IN EASTERN IA THIS MORNING WILL EXPAND IN COVERAGE AND THE RAIN WILL BE WIDESPREAD THIS AFTERNOON AND TONIGHT. ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE...MAINLY THIS AFTERNOON. A COLD FRONT WILL ALSO ARRIVE TONIGHT. EAST TO SOUTHEAST WINDS LESS THAN 10 KNOTS TODAY THEN BECOMING NORTHWEST 15 TO 25 KNOTS BEHIND THE COLD FRONT TONIGHT. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...HAASE SYNOPSIS...HAASE SHORT TERM...HAASE LONG TERM...MCCLURE AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS DULUTH MN
949 AM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 945 AM CDT SUN APR 19 2015 RAIN WILL CONTINUE TO AFFECT THE FORECAST AREA THROUGH THE DAY. HOWEVER...THERE WILL BE AN HOUR OR TWO WHEN NO RAIN IS OCCURRING AND TRIED TO ACCOUNT FOR THIS IN THE FORECAST. KEPT THE MAX TEMPS THE SAME FOR NOW...BUT WILL LOOK INTO LOWERING LATER TODAY. REST OF THE FORECAST IN THE BALLPARK. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT. AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA. THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY WINDS. THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST AREA LATE THIS MORNING. THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN MANITOBA. LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA. LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING. MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS. SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO JUST NORTH OF KOOCHICHING COUNTY. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES... FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY. THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW. STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S ON THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 656 AM CDT SUN APR 19 2015 A LARGE AREA OF LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST INTO THE NORTHLAND TODAY AND TONIGHT. ABUNDANT MOISTURE THROUGH THE PLAINS WILL CONTINUE TO BRING AREAS OF LIGHT RAIN TODAY INTO TONIGHT. CLOUD HEIGHTS ARE EXPECTED TO GRADUALLY DECREASE TO MVFR OR EVEN IFR DURING THE MORNING...AND REMAIN THAT WAY THROUGH THE AFTERNOON. SOME IMPROVEMENT IN CLOUD HEIGHTS WILL BE POSSIBLE FROM THE WEST...AS SOMEWHAT DRIER AIR PUSHES EASTWARD BEHIND A COLD FRONT. && .PRELIMINARY POINT TEMPS/POPS... DLH 49 34 44 29 / 90 30 30 60 INL 49 32 40 28 / 100 40 60 60 BRD 56 35 43 31 / 80 20 40 40 HYR 58 37 46 30 / 90 80 30 60 ASX 58 37 47 32 / 80 80 20 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ142>147. && $$ UPDATE...GSF SHORT TERM...GROCHOCINSKI LONG TERM...DAP AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
701 AM CDT SUN APR 19 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT. AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA. THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY WINDS. THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST AREA LATE THIS MORNING. THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN MANITOBA. LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA. LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING. MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS. SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO JUST NORTH OF KOOCHICHING COUNTY. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES... FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY. THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW. STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S ON THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 656 AM CDT SUN APR 19 2015 A LARGE AREA OF LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST INTO THE NORTHLAND TODAY AND TONIGHT. ABUNDANT MOISTURE THROUGH THE PLAINS WILL CONTINUE TO BRING AREAS OF LIGHT RAIN TODAY INTO TONIGHT. CLOUD HEIGHTS ARE EXPECTED TO GRADUALLY DECREASE TO MVFR OR EVEN IFR DURING THE MORNING...AND REMAIN THAT WAY THROUGH THE AFTERNOON. SOME IMPROVEMENT IN CLOUD HEIGHTS WILL BE POSSIBLE FROM THE WEST...AS SOMEWHAT DRIER AIR PUSHES EASTWARD BEHIND A COLD FRONT. && .PRELIMINARY POINT TEMPS/POPS... DLH 49 34 44 29 / 80 30 30 60 INL 49 32 40 28 / 90 40 60 60 BRD 56 35 43 31 / 80 20 40 40 HYR 58 37 46 30 / 80 80 30 60 ASX 58 37 47 32 / 80 80 20 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ142>147. && $$ SHORT TERM...GROCHOCINSKI LONG TERM...DAP AVIATION...DAP
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
727 AM CDT Sun Apr 19 2015 .UPDATE... Issued at 723 AM CDT SUN APR 19 2015 Made major adjustments to the forecast. Lowered PoPs considerably for the rest of the morning south and west of a h7 vorticity lobe that defines the back edge of showers over northern and into central MO...roughly along an arc from St. Joseph to Sedalia. Trend of the HRRR, RUC and even the NAM supports the above scenario. Convective cluster over north central OK may graze the far southern counties this afternoon so likely PoPs this area seems reasonable. So, for a good portion of today many areas will see little in the way of measurable rainfall. Still believe we`ll see a band of stratiform type rain tied to the post-frontal baroclinic zone/deformation zone that will slide ese across the CWA from late afternoon through this evening. && .SHORT TERM...(Today through Tuesday) Issued at 407 AM CDT SUN APR 19 2015 Today - Tonight: Today`s weather will be governed by the transition of an upper level closed low to an open wave. Latest water vapor satellite imagery shows the closed upper low has now shifted east into west central KS early this morning. A shortwave trough digging into the Northern High Plains will push this feature and its associated convection through the CWA today with the rain ending from west to east this evening. Scattered showers and isolated thunderstorms will accompany a couple mid level vorticity lobes as they rotate northeast across KS and MO. No severe storms are expected today as less than impressive MUCAPEs in the 400-800 J/kg range and bulk shear values around 25kts will limit the strength of the storms. Like yesterday a few cells could produce small hail during peak heating. Temperatures will again be negatively impacted by the convection and cloud cover. A more organized band of stratiform rain tied to post-frontal frontogenesis and an elongated deformation zone overspreads the region during the evening hours. Monday - Tuesday: The Northern Plains upper trough will gradually sharpen south and shift east on Monday with strong subsidence spilling southeast on the backside of the trough. Clearing skies will help offset cold air advection yielding slightly below average temperatures both days. The operational models are showing similar weak signals on Tuesday that we`ll need to start considering the chance of some shower activity. The models generate a series of weak strung out vorticity lobes stretching southeast from NE through MO. Moisture will be the main limiting factor so if any rain forms it will be light and scattered. .LONG TERM...(Wednesday through Saturday) Issued at 407 AM CDT SUN APR 19 2015 Slightly below normal temperatures will stretch through the latter half of the week as deep low pressure very slowly transitions SE across the Great Lakes, and northwest flow aloft ushers cooler temperatures into the region. At the same time a surface boundary will drift southward through Wednesday, leaving the forecast area in north to northeast surface flow and also helping to keep highs in the lower to mid 60s. A few light showers and isolated storms are possible over the southern tier of the CWA Wednesday and Wednesday night as the front heads south, then a period of drier conditions is expected on the north side of the boundary Thursday. Southerly surface flow will eventually return by the end of the work week ahead of a shortwave trough that will eject out of the desert southwest and into the Plains by Friday. Widely scattered showers and storms are possible as early as Friday afternoon, but are more likely Friday night as the upper trough passes over the CWA. Timing of this system is still a bit uncertain, and the probability of any embedded storms will depend on how quickly southerly flow and low- level moisture return to the region ahead of the shortwave trough. At this time, the southern track of the associated surface low and the environment in place ahead of the system suggests that the potential for strong storms is very low. The clouds and any rain associated with the system will keep temperatures down despite the transition to southerly flow, so have kept highs mainly in the lower 60s through the end of the work week and into the weekend. Current model trends show the wet weather clearing out by Saturday evening and a dry Sunday, but will have to watch the potential for Friday`s system to slow down and impact the coming weekend. && .AVIATION...(For the 12Z TAFS through 12Z Monday Morning) Issued at 635 AM CDT SUN APR 19 2015 Scattered showers and a few storms lifting north through northern MO may define the last of the rain till late this afternoon and evening when deformation band of stratiform type rain moves in. The onset of gusty northwest winds will likely signal when this band will move in with its MVFR ceilings. Till then think much of the day will only see spotty hit/miss type showers. Thunderstorm risk looks minimal. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...MJ SHORT TERM...MJ LONG TERM...Laflin AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT SUN APR 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT SUN APR 19 2015 THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE PANHANDLE. THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL WOULD BE EXPECTED. HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN THE AFTERNOON WITH THE COLD AIR ALOFT. TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA. GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER 30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER LOWS ARE EXPECTED. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 313 AM CDT SUN APR 19 2015 MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND. BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 620 AM CDT SUN APR 19 2015 SATELLITE SUGGESTS THE DEFROMATION ZONE CAUSING MVFR CIGS/-RA MAY HAVE STALLED ACROSS SOUTHERN NEBRASKA. A COLD FRONT IS RACING SOUTH WHICH SHOULD DRY THIS AIR OUT ENDING THE RAIN AND LOW CIGS. THIS SUGGESTS VFR WOULD BE WIDESPREAD THROUGHOUT THE FCST AREA BY 15Z-18Z. VFR IS EXPECTED ALL AREAS THEREAFTER. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
913 AM MDT SUN APR 19 2015 .UPDATE... ADDED QUAY AND CURRY COUNTIES TO THE WIND ADVY FOR TODAY AND TWEAKED UP WIND SPEEDS OUT THERE. OTHERWISE NO CHANGES. && .PREV DISCUSSION...553 AM MDT SUN APR 19 2015... .AVIATION... 12Z TAF CYCLE SIGNIFICANT BACKDOOR COLD FRONT WILL SLIDE FARTHER SOUTH ACROSS THE ERN PLAINS THIS MORN. NORTH WINDS OF 18 TO 30KT WITH GUSTS BETWEEN 35 AND 45KT CAN BE EXPECTED ACROSS THE NE QUARTER OF NM... THE STRONGEST IN THE VICINITY OF UNION COUNTY BETWEEN 14Z AND 19Z SUNDAY. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED AFTERNOON AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE NORTHERN MTS AND ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN INCLUDING KLVS...EAST SLOPES OF THE SANGRE DE CRISTOS MOST FAVORED. ISOLATED EVEN HIGHER BASED CONVECTION POSSIBLE ALSO ACROSS THE SW MTS THIS AFTN. LATE TONIGHT THERE IS A POSSIBILITY OF SOME NEAR MVFR CIGS ACROSS AREAS E AND SE FROM THE E SLOPES OF THE SANGRE DE CRISTOS. 43 && .PREV DISCUSSION...337 AM MDT SUN APR 19 2015... .SYNOPSIS... AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST. DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE OVER THE NORTH THROUGH NEXT WEEKEND. && .DISCUSSION... THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT. ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT TREND TOWARD NORMAL FOR THE FAR WEST. AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY. BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY DEFINED SHORTWAVE TROUGHS AND RIDGES. GUYER && .FIRE WEATHER... WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS DIMINISHED SOMEWHAT. A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN. GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST. LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF NORMAL EAST...VERY CLOSE TO NORMAL WEST. THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH AID OF AFTN HEATING. WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE THU AFTN. NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY SEE SOME EROSION OF VENTILATION RATES. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING ZONES...NMZ530-534-535. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
553 AM MDT SUN APR 19 2015 .AVIATION... 12Z TAF CYCLE SIGNIFICANT BACKDOOR COLD FRONT WILL SLIDE FARTHER SOUTH ACROSS THE ERN PLAINS THIS MORN. NORTH WINDS OF 18 TO 30KT WITH GUSTS BETWEEN 35 AND 45KT CAN BE EXPECTED ACROSS THE NE QUARTER OF NM... THE STRONGEST IN THE VICINITY OF UNION COUNTY BETWEEN 14Z AND 19Z SUNDAY. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED AFTERNOON AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE NORTHERN MTS AND ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAIN CHAIN INCLUDING KLVS...EAST SLOPES OF THE SANGRE DE CRISTOS MOST FAVORED. ISOLATED EVEN HIGHER BASED CONVECTION POSSIBLE ALSO ACROSS THE SW MTS THIS AFTN. LATE TONIGHT THERE IS A POSSIBILITY OF SOME NEAR MVFR CIGS ACROSS AREAS E AND SE FROM THE E SLOPES OF THE SANGRE DE CRISTOS. 43 && .PREV DISCUSSION...337 AM MDT SUN APR 19 2015... .SYNOPSIS... AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST. DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE OVER THE NORTH THROUGH NEXT WEEKEND. && .DISCUSSION... THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT. ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT TREND TOWARD NORMAL FOR THE FAR WEST. AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY. BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY DEFINED SHORTWAVE TROUGHS AND RIDGES. GUYER && .FIRE WEATHER... WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS DIMINISHED SOMEWHAT. A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN. GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST. LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF NORMAL EAST...VERY CLOSE TO NORMAL WEST. THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH AID OF AFTN HEATING. WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE THU AFTN. NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY SEE SOME EROSION OF VENTILATION RATES. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING ZONES...NMZ530. && $$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
930 AM EDT SUN APR 19 2015 .SYNOPSIS... HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE NORTHWEST THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 925 AM SUNDAY...MADE SOME SLIGHT ADJUSTMENTS TO NEAR-TERM POPS AS LEADING EDGE OF PRECIPITATION SHIELD NOW MOVING INTO NORTHEAST SOUTH CAROLINA AND WILL LIKELY BE A FEW MORE HOURS UNTIL IT ARRIVES IN OUR CWA. THERE ARE A FEW ISOLATED SHOWERS OCCURRING INLAND DUE TO SOME WEAK ISENTROPIC LIFT. GENERALLY FOLLOWED THE 3KM HRRR WHICH IS DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO CHANGES THROUGH THE AFTERNOON AS RAIN BECOMES WIDESPREAD AND STEADY. CONVECTIVE DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON CURRENT PARAMETERS AS BEST INSTABILITY OCCURRING MUCH FURTHER SOUTHWEST ACROSS GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO CHANGE TO TEMPERATURE FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST AREAS STILL SEEING 1/2 TO 1 INCH. PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT. GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN LIMITING INSTABILITY. MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/ VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA- BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT. INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES. MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON. TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND TO AFTERNOON HIGHS IN THE MID 70S. WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER 70S THURSDAY AFTERNOON. THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE. FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL CHANCE OF RAIN IN THE AFTERNOON. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... SHORT TERM /THROUGH 12Z MONDAY/... AS OF 700 AM SUNDAY...LIFT STRATUS CIGS DEVELOPED ALL TAF SITES 10-11Z WITH LIFR VSBYS AS WELL AT KPGV AND KISO. CONDITIONS EXPECTED TO LIFT TO VFR BY AROUND 13Z. VFR PERSISTING INTO EARLY AFTN...THEN CONDITIONS DETERIORATING. WIDESPREAD SHOWERS/ISOLD TSTMS EXPECTED TO DEVELOP AND SPREAD SW TO NE ACROSS AREA THIS AFTN INTO EARLY EVENING...WITH WDSPRD IFR CIGS LIKELY ALL TAF SITES BY 00Z AND PERSISTING OVERNIGHT WITH VSBYS 3-5 SM IN SHRA. LIGHT WINDS THIS MORNING WILL BECOME SE 10-15 KT THIS AFTN INTO EVENING. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 930 AM SUNDAY...NO MAJOR CHANGES TO THE CURRENT FORECAST WITH LIGHT NORTHEAST WINDS INTO EARLY AFTERNOON...BECOMING E-SE AS WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO 20 KNOTS BY THIS EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM FRONT MOVING IN FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25 KT. SEAS BUILDING TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING 6-8 FT LATE TONIGHT. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY. HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO 2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT REMAIN 5-15 KT WITH SEAS 2-4 FEET. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT TUESDAY FOR AMZ150-152-154-156-158. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...DAG AVIATION...JBM/DAG MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
929 AM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 929 AM CDT SUN APR 19 2015 THE FORECAST FOR THE REMAINDER OF TODAY IS ON TRACK WITH THE STRATUS FIELD OVERTAKING WESTERN AND CENTRAL NORTH DAKOTA EXPECTED TO SLOWLY SCATTER WITH DIURNAL HEATING WITH RAIN SHOWER COVERAGE INCREASING THROUGH THE AFTERNOON. THIS IS IN LINE WITH THE 12-13 UTC HRRR ITERATIONS. UPDATE ISSUED AT 629 AM CDT SUN APR 19 2015 INITIAL BATCH OF WIDESPREAD RAIN CONTINUES TO PUSH OFF TO THE EAST...THOUGH SECONDARY ROUND OF SCATTERED WRAP AROUND SHOWERS ARE STARTING TO DEVELOP AND WORK INTO FAR NORTHWEST NORTH DAKOTA. HAVE ADJUSTED POPS TO ACCOUNT FOR THIS. HAVE ALSO INCREASED CLOUD COVER MAINLY OVER THE WEST AS CLOUDS CONTINUE TO STREAM IN BEHIND THE LOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT SUN APR 19 2015 CONTINUED CHANCES FOR RAIN AND WINDY CONDITIONS THROUGH SUNDAY...HIGHLIGHT THE SHORT TERM. AN UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS WILL CONTINUE TO PROVIDE AMPLE MOISTURE AND INSTABILITY...PROLONGING CHANCES FOR WIDESPREAD SHOWERS IN CENTRAL AND EASTERN AREAS OF THE STATE THROUGH THE DAY. ADDITIONALLY...TEMPERATURES SLIGHTLY BELOW AVERAGE AND STRONG NORTHWEST WINDS WILL ACCOMPANY THE DEEPENING TROUGH. THE CURRENT 00Z MODEL SUITE PROVIDES GOOD AGREEMENT ON THE UPPER LEVEL TROUGH DIGGING AND SLOWLY MOVING EASTWARD...PUSHING OVER MINNESOTA/EASTERN MANITOBA AND CLOSING OFF BY 12Z MONDAY. NORTH CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY HAVE THE POTENTIAL FOR A FEW SNOW FLAKES EARLY MONDAY MORNING...AS COLD AIR FILTERING SOUTHWARD FROM CANADA IS EXPECTED TO DROP OVERNIGHT LOWS TO JUST BELOW FREEZING. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 400 AM CDT SUN APR 19 2015 UPPER LOW WILL WORK ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY. THIS SHOULD KEEP PRECIPITATION TO THE EAST OF OUR AREA THROUGH THE DAY...THOUGH GUSTY NORTHWEST WINDS WILL CONTINUE IN THE WAKE OF THE SYSTEM. A FAST MOVING WAVE WILL MOVE IN BEHIND THE SYSTEM LATE TUESDAY NIGHT INTO EARLY WEDNESDAY WHICH MAY BRING A LITTLE LIGHT PRECIPITATION TO CENTRAL NORTH DAKOTA...BUT WILL KEEP POPS LOW WITH LACK OF MUCH MOISTURE TO WORK WITH. QUIET AND COOL CONDITIONS ARE THEN EXPECTED WITH RIDGING TO THE WEST AND NORTHWESTERLY FLOW OVER OUR AREA. MODELS START TO DISAGREE WITH THE POSITION OF THE RIDGE AND WHETHER A FEW UPPER WAVES WILL MAKE IT THROUGH THE AREA TOWARDS THE END OF THE WEEK. THEREFORE...WILL KEEP ANY PRECIPITATION CHANCES ON THE LOW SIDE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 925 AM CDT SUN APR 19 2015 MVFR/VFR STRATUS WILL CONTINUE TO SPREAD ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING. THIS DECK IS EXPECTED TO SLOWLY LIFT AND SCATTER INTO THE AFTERNOON WITH RAIN SHOWER COVERAGE ALSO INCREASING INTO THE AFTERNOON. STRONG NORTHWEST WIND GUSTS OF 30-35 KTS ARE ALSO FORECAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA TODAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...AC LONG TERM...JJS AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
959 AM EDT SUN APR 19 2015 .SYNOPSIS... HIGH PRESSURE WAS OVER SOUTHEAST CANADA AND LOW PRESSURE WAS IN ARKANSAS WITH A WARM FROM EXTENDING INTO SOUTH CAROLINA. THE LOW AND WARM FRONT WILL MOVE NORTH TODAY AND TONIGHT. A COLD FRONT CROSSES THE REGION ON MONDAY THEN HIGH PRESSURE BUILDS IN FOR TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 958 AM EDT SUNDAY... FLOOD WATCHES REMAIN IN EFFECT FROM THIS AFTERNOON INTO TONIGHT. A WARM FRONT WILL LIFT NORTH TODAY AND CROSS THE FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE FRONT. THE RNK WRF-ARW...HIRESW-ARW AND HRRR SHOWED WIDESPREAD RAIN LIFTING NORTHWARD ACROSS OUR AREA. LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF CWA. MODIFIED TEMPERATURES...DEW POINT AND POPS FR THIS MORNING INTO THIS AFTERNOON. MORE ADJUSTMENTS AS THE DAY PROGRESSES... AS OF 430 AM EDT SUNDAY... WARM FRONT ASSOCIATED WITH A LOW IN ARKANSAS WILL MOVE NORTH TODAY AND WILL CROSS THROUGH THE FORECAST AREA TONIGHT. STRONG SYNOPTIC SCALE LIFT WILL PRODUCE WIDESPREAD RAIN ACROSS THE FORECAST AREA. LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. RAIN WILL SPREAD INTO THE AREA FROM SOUTHWEST TO NORTHEAST BEFORE 18Z/2PM. MOST LOCATIONS WILL HAVE ABOUT A 12 HOUR PERIOD OF LIGHT TO MODERATE RAIN. HAVE PRECIPITATION ENDING FROM SOUTHWEST TO NORTHEAST AFTER 06Z/2AM. TEMPERATURES STARTING THE DAY QUITE MILD. GRIDDED LAMP GUIDANCE INDICATED STEADY AND POSSIBLY SLIGHTLY FALLING TEMPERATURES TODAY. LITTLE CHANGE IN AIR MASS IS EXPECTED TONIGHT WITH TEMPERATURES AND DEW POINTS REMAINING MAINLY IN THE 50S. THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON INTO THIS EVENING. THERE IS A LOW CHANCE THERE COULD BE ENHANCED DIRECTIONAL SHEAR AS THE WARM FRONT CROSSES. FOR NOW WILL LEAVE OUT ANY THUNDER. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... AS OF 345 AM EDT SUNDAY... THE NEW WEEK STARTS OFF WITH OUR REGION IN A WARM AND MOIST AIRMASS. AS TEMPERATURES RISE WELL INTO THE 70S ON MONDAY THE ATMOSPHERE WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT AND THUNDERSTORMS ARE EXPECTED TO DEVELOP. THE DYNAMIC ENVIRONMENT SUPPORTS THE CHANCE FOR SOME SEVERE STORMS AND THE SPC SLIGHT RISK LOOKS TO BE ON TARGET ACROSS OUR AREA WITH THE POTENTIAL FOR SVR WEATHER INCREASING EASTWARD WHERE INSTABILITY WILL BE GREATER. IT WILL ALSO BE QUITE BREEZY WITH EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER. THE FRONT SHOULD BE CLEARING THE EASTERN ZONES EARLY MONDAY EVENING. COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR WESTERN SLOPES MONDAY NIGHT. A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE RIDGE AND MID 60S TO AROUND 70 EAST. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 350 PM EDT SATURDAY... MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE CONCERN AT THIS POINT. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... AS OF 745 AM EDT SUNDAY... RAIN HAD ADVANCED INTO SOUTHWEST VIRGINIA AND WESTERN NORTH CAROLINA THIS MORNING WITH CEILINGS LOWERING IN ADVANCE OF THE RAIN. RAIN WILL BEGIN AT KBLF AROUND THE 12Z START OF THE TAF TIME AND BY 16Z/NOON AT THE OTHER TAF SITES. A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE TODAY AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS TODAY. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. HAVE LLWS IN THE KDAN...KLWB AND KBCB TAFS AFTER 00Z/8PM. A STRONG UPSLOPE FLOW WILL TRANSPORT ABUNDANT MOISTURE INTO THE REGION NORTH OF A STATIONARY FRONT TODAY. CEILINGS WILL LOWER TO IFR BY THIS AFTERNOON AND WILL REMAIN LOW OVERNIGHT. EXTENDED AVIATION... A COLD FRONT APPROACHES LATER MONDAY WITH SOME STORMS POSSIBLE AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING. VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS. THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY. && .HYDROLOGY... AS OF 430 AM EDT SUNDAY... HAVE EXPANDED THE FLOOD WATCH FOR MORE OF THE SOUTHERN BLUE RIDGE AND FOR THE BLUE RIDGE AND ADJACENT EASTERN COUNTIES NORTH OF OF ROANOKE. BUFKIT SOUNDINGS SHOWED A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE ATMOSPHERE WITH SOUTHEAST WINDS...THAT WILL BE INCREASING TO AROUND 50 KNOTS THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME. TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH 12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO 2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS. PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER. HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL THROUGH MONDAY MORNING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012>017-032. FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT FOR VAZ022>024-033>035. NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...MBS LONG TERM...RAB AVIATION...AMS/PC HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
551 AM CDT SUN APR 19 2015 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND MONDAY ISSUED AT 327 AM CDT SUN APR 19 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS. TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT MUCH COOLER READINGS OVER EASTERN WI THOUGH. TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH. MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S NORTH TO LOW 50S SOUTH. .LONG TERM...MONDAY NIGHT THROUGH SATURDAY ISSUED AT 327 AM CDT SUN APR 19 2015 CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN WEDNESDAY MORNING. BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION CHANCES AND TEMPERATURES DURING THE PERIOD. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 551 AM CDT SUN APR 19 2015 BROKEN MID-LEVEL CLOUDS THROUGH THIS AFTERNOON WITH SPOTTY SHOWERS POSSIBLE. THEN AS LOW PRESSURE MOVES ACROSS THE REGION TONIGHT...STEADY RAIN WILL MOVE ACROSS THE TAF SITES BEGINNING THIS EVENING AND CONTINUING FOR MUCH OF THE NIGHT. EXPECT CIGS AND VSBYS TO LOWER ONCE THE RAIN ARRIVES. IFR CIGS LOOK LIKELY...AND SOME THREAT OF LIFR CIGS BASED ON UPSTREAM OBS OVER THE NORTHERN PLAINS AND MOS GUIDANCE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ECKBERG AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 PM EDT SUN APR 19 2015 .DISCUSSION... TONIGHT...SOUTHERN EDGE OF CONVECTIVE BAND MOVING INTO NE GULF AND NORTH FL HAS BEEN WEAKENING RECENTLY AND HRRR/WRF MODELS INDICATE THIS TREND WILL CONTINUE. HOWEVER SOME PRECIP/EMBEDDED STORM ACTIVITY FROM THIS BAND MAY REACH LAKE COUNTY TOWARD SUNSET. AHEAD OF THIS LINE HRRR CONTINUES TO SHOW SOME ISO/SCT STORMS FORMING ESPECIALLY NEAR THE COAST FROM BOUNDARY COLLISIONS WITH THE EAST COAST SEA BREEZE. LATEST SFC OBS SHOW THE SEA BREEZE HAS BEEN ABLE TO HOLD ON RIGHT ALONG THE COAST AT SOME LOCATIONS. HOWEVER AN INCREASING LOW LEVEL S/SW FLOW INTO LATE DAY MAY PUSH WHAT SEA BREEZE REMAINS OFFSHORE. IF SO CONVECTIVE ACTIVITY MAY BE LIMITED INTO THIS EVENING. FOR NOW WILL HOLD ONTO A CHANCE FOR STORMS INTO THE EVENING MAINLY ALONG THE COAST. IF ANY BOUNDARY COLLISIONS DO OCCUR ISO STRONG STORMS NOT OUT OF THE QUESTION. RAIN CHANCES END BY MIDNIGHT WITH ANY SHOWERS/STORMS PUSHING OFFSHORE. OVERNIGHT LOWS WILL BE IN THE UPPER 60S TO LOW 70S. MONDAY...MODELS SHOW ANOTHER MID LEVEL S/W PUSHING THROUGH THE NRN GULF AHEAD OF WEAK FRONT MOVING INTO THE SOUTHEAST STATES. THIS DISTURBANCE WILL LIKELY LEAD TO ANOTHER BAND OF CONVECTION DEVELOPING OVER THE CENTRAL/EASTERN GULF SHIFTING EASTWARD TOWARD THE FL PENINSULA IN THE EARLY MORNING HOURS. NAM AND TO A DEGREE THE WRF SHOW THIS BAND DEVELOPING FARTHER NORTH AND PUSHING ACROSS MUCH OF THE REGION INTO THE AFT WHILE THE GFS/ECMWF KEEP GREATEST RAIN CHANCES/MOISTURE SOUTH OF ORLANDO. HAVE LEANED TOWARD A BLEND FOR NOW WHICH KEEPS RAIN CHANCES FAIRLY CONSISTENT AROUND 50-60 PERCENT. SOME STRONG TO ISO SEVERE STORMS POSSIBLE IF ENOUGH HEATING CAN OCCUR OUT AHEAD OF ANY CONVECTION OVER THE GULF. MAIN THREAT WOULD BE STRONG WIND GUSTS AND HAIL. TUE...A COOL FRONT WILL SETTLE SOUTH ACROSS CENTRAL FL BRINGING SOME DRIER AIR AND TEMPERATURES MORE SEASONABLE FOR THIS TIME OF YEAR IN THE LOW TO MID 80S. HAVE LOWERED RAIN CHANCES ACROSS THE NORTH TO 20 PERCENT NORTH OF ORLANDO AND THIS MAY BE GENEROUS. MOISTURE LINGERING ACROSS THE SOUTH WILL KEEP RAIN CHANCES 40 TO 50 PERCENT FROM OKEECHOBEE TO THE TREASURE COAST. REST OF WEEK (PREVIOUS)...DEPARTURE OF STRONG UPR WIND MAXIMA WL BRING EVOLUTION TO ZONAL PATTERN WITH BROAD WEAK HIGH DOWNSTREAM ACTING TO STABILIZE AIRMASS...WITH SOME DRYING AS WELL OVER THE NORTH AT MIDWEEK. AFTERNOON BOUNDARY INTERACTION AND SUFFICIENT LL MOISTURE WL FORCE SOME SHOWERS AND SLOW MOVING STORMS WED-THU WITH AT LEAST MENTIONABLE RAIN CHCS IN THE EXTENDED FCST LACKING ANY NOTABLE PATTERN CHG AND OR DRYING OF THE AMBIENT AIRMASS. && .AVIATION... TEMPO IFR/MVFR CONDS IN ISO/SCT SHRA/TSRA MAINLY TOWARD THE COAST WILL OCCUR AHEAD OF APPROACHING BAND OF CONVECTION THAT IS WEAKENING OVER THE NE GULF. THIS BAND MAY REACH AREAS WEST OF I-4 TOWARD SUNSET...PRODUCING ADDITIONAL REDUCTIONS TO CIG/VIS MAINLY AT KLEE. CONVECTION THEN DIMINISHING/PUSHING OFFSHORE INTO LATE EVENING WITH MAINLY VFR OVERNIGHT. DEEP MOISTURE AND AN APPROACHING DISTURBANCE ALOFT WILL KEEP HIGH RAIN CHANCES IN THE FORECAST FOR TOMORROW WITH SCT-NMRS SHRA/TSRA PRODUCING TEMPO IFR/MVFR CONDS INTO THE AFT. && .MARINE... TONIGHT-MONDAY...S/SW WINDS UP TO 10-15 KNOTS WILL BECOME MORE W/SW INTO LATE MON AS A WEAK FRONTAL BOUNDARY PUSHES INTO THE SOUTHEAST STATES. SEAS WILL REMAIN AROUND 2-4 FEET. MAIN CONCERN WILL CONTINUE TO BE FOR OFFSHORE MOVING STORMS THIS EVENING AND TOMORROW AFT/EVE... PRODUCING STRONG GUSTY WINDS. TUE-THU...WEAK FRONT PROGGED TO MOVE DOWN THE FL PENINSULA TUE SO WIND FLOW WILL BE W/NW 10 KNOTS. FLOW BEHIND THE FRONT MID WEEK WILL BECOME ONSHORE AROUND 10 KNOTS. SEAS WILL REMAIN 4 FEET OR LESS. && .PRELIMINARY POINT TEMPS/POPS... DAB 69 84 68 80 / 40 40 20 20 MCO 70 87 69 83 / 20 50 20 30 MLB 71 87 70 82 / 40 60 30 30 VRB 70 87 70 83 / 40 60 30 50 LEE 70 84 68 82 / 20 50 20 20 SFB 70 85 69 83 / 30 50 20 20 ORL 71 86 69 83 / 20 50 20 30 FPR 69 87 70 83 / 40 60 30 50 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...WEITLICH LONG TERM....KELLY
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
127 PM EDT SUN APR 19 2015 ...TORNADO WATCH TIL 8PM I-10 CORRIDOR NORTHWARD... ...POTENTIAL FOR A FEW STRONG/SEVERE STORMS AGAIN MONDAY... .NEAR TERM...THROUGH TONIGHT... WATER VAPOR SHOWING AN IMPRESSIVE SHORTWAVE THAT WILL MOVE EASTWARD TOWARD AND OVER FORECAST AREA THROUGH THIS EVENING. BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL ACCOMPANY WAVE THIS AFTERNOON. SUFFICIENT INSTABILITY AND DEEP-LAYER SHEAR AHEAD OF SYSTEM TO SUPPORT A FEW STRONG OR SEVERE STORMS EMBEDDED WITHIN THE LINE...MAINLY BOWING LINE SEGMENTS WITH DAMAGING WIND POTENTIAL...THOUGH AN ISOLATED TORNADO IS ALSO POSSIBLE. IN ADDITION...STARTING TO SEE CONVECTION BREAK OUT AHEAD OF SYSTEM OVER OUR WRN COUNTIES. GIVEN THE ENVIRONMENT IN PLACE...THERE IS POTENTIAL FOR A FEW DISCRETE STRONG/SEVERE CELLS TO DEVELOP THIS AFTERNOON. LATEST HRRR SUGGESTS THIS ACTIVITY COULD INTENSIFY AS IT SPREADS NORTHEAST OVER THE NEXT FEW HOURS. TORNADO WATCH IS IN EFFECT FOR AREAS FROM THE I-10 CORRIDOR NORTHWARD TIL 8PM. BAND OF SHOWERS/STORMS WILL MOVE QUICKLY NORTH AND EAST ACROSS FORECAST AREA BETWEEN 2PM AND 7PM...THEN MOVE OFFSHORE. LOW TEMPS EXPECTED TO BE 68-70 MOST LOCATIONS. SHORT TERM...MONDAY THROUGH TUESDAY NIGHT... FOR MONDAY...COLD FRONT APPROACHES FROM THE NORTHWEST. MORE WESTERLY FLOW AT LOW AND MID LEVELS BRINGS IN DRIER AIR...AND AS A RESULT THE MODELS DEVELOP CONSIDERABLY LESS PRECIP COVERAGE MONDAY AFTERNOON COMPARED TO THIS AFTERNOON. WILL MAINTAIN 30-40 POP FOR MONDAY AFTERNOON. ONCE AGAIN SPC HAS SLIGHT RISK OF SEVERE STORMS OVER OUR AREA...AND ONCE AGAIN WE SHOULD HAVE FAVORABLE COMBINATION OF MODERATE CAPE AND SUFFICIENT DEEP LAYER SHEAR. LOW-LEVEL WINDS WILL BE MORE SW AHEAD OF COLD FRONT...AND THIS WILL REDUCE HELICITY...SO PRIMARY THREAT WILL BE STRONG WINDS. WARM AGAIN MONDAY WITH HIGHS IN THE MID 80S ACROSS THE FORECAST AREA. COLD FRONT MOVES ACROSS THE AREA LATE MONDAY NIGHT...WITH SOMEWHAT COOLER DRIER CONDITIONS TUESDAY. CURRENT FORECAST HIGH TEMPS OF UPPER 70S SE GA...AROUND 80 I-10 CORRIDOR...AND LOW 80S GNV/OCF LOOKS FINE. COOLER NIGHT TUESDAY NIGHT WITH LOW TEMPS 55-60 ACROSS THE AREA...EXCEPT LOW 60S COAST. LONG TERM...WEDNESDAY THROUGH SUNDAY... GIVEN THE HIGH IMPACT THREATS THROUGH MONDAY...DID NOT MAKE SIGNIFICANT CHANGES TO THE MEDIUM RANGE GIVEN NOT MUCH SIGNIFICANT CHANGE IN LATEST MODEL GUIDANCE. STILL EXPECT WEAK SURFACE RIDGING AND ZONAL FLOW ALOFT THROUGH THE END OF THE WORKWEEK...WITH SOME INCREASE IN TEMPS AS WELL AS SLIGHT CHANCES FOR SHOWERS WITH SEA BREEZES. BETTER RAIN CHANCES MAY STILL COME OVER WEEKENDD... THOUGH SOME UNCERTAINTY AS TO TRACK OF NEXT WEEK SYSTEM AND WHERE THE MORE WIDESPREAD PRECIPITATION WILL END UP. && .AVIATION...MAIN SQUALL LINE WELL WEST OF THE LOCAL FIELDS WITH GAINESVILLE MOST LIKELY TO FEEL ITS IMPACT. EXPECT CONVECTION TO MOVE IN THERE BETWEEN 19-21 UTC WITH CEILINGS IN THE 2.5 KFT RANGE. THE COAST FIELDS FROM SAINT AUGUSTINE THROUGH THE JACKSONVILLE METRO AREA TO SAINT SIMONS ISLAND SHOULD SEE A CONVERGENCE BETWEEN THE DOMINANT SOUTHWESTERLY LOW LEVEL FLOW PATTERN AND THE DEVELOPING ATLANTIC SEA BREEZE FRONT. EXPECT STRONG TO POSSIBLY SEVERE CONVECTION TO FIRE UP ALONG THE ATLANTIC COAST WITH CEILINGS BETWEEN 2.5-5 KFT. THESE STORMS SHOULD PASS OFFSHORE THIS EVENING BY 23OO UTC AS THE WEAKENING SQUALL LINE MAKES ITS RUN AT THE COAST. && .MARINE....WINDS WILL GRADUALLY INCREASE AND VEER OUT AHEAD OF APPROACHING COLD FRONT ALTHOUGH NO HEADLINES EXPECTED THRU MONDAY. THE COLD FRONT CROSSES THE WATERS MONDAY NIGHT BRINGING A BRIEF PERIOD OF CONDITIONS APPROACHING ADVISORY CRITERIA IN THE OFFSHORE COMPONENT. SCATTERED TO NUMEROUS AFTERNOON AND EVENING SHOWERS/TSMS THRU MONDAY... WITH STRONG WINDS POSSIBLE WITH THE MORE INTENSE STORMS. HIGH PRESSURE QUICKLY BUILDS IN BEHIND THE FRONT TUE WITH WIND/SEAS DECREASING FOR REMAINDER OF WEEK. .RIP CURRENTS...MODERATE RISK THIS AFTERNOON...LOW RISK MONDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 67 85 60 77 / 30 30 20 10 SSI 69 82 65 75 / 30 30 20 10 JAX 69 85 64 79 / 30 30 20 10 SGJ 70 83 67 77 / 30 40 20 10 GNV 68 85 65 81 / 20 40 20 10 OCF 69 85 66 82 / 20 40 20 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ WOLF/SANDRIK/WALKER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
425 PM EDT SUN APR 19 2015 .SYNOPSIS... A COLD FRONT WILL APPROACH THE AREA MONDAY. THE FRONT WILL CROSS THE REGION MONDAY NIGHT AND WILL SHIFT OFFSHORE BY EARLY TUESDAY. HIGH PRESSURE WILL THEN PREVAIL TUESDAY INTO THURSDAY. A WEAK COLD FRONT WILL DROP THROUGH THE AREA THURSDAY NIGHT...THEN WILL STALL JUST SOUTH OF THE REGION LATE WEEK. A STORM SYSTEM WILL AFFECT THE REGION NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... REST OF THE AFTERNOON AND EVENING...THUNDERSTORMS ARE CURRENTLY PROGRESSING THROUGH SOUTHEAST GEORGIA AND THE TORNADO WATCH HAS BEEN EXPANDED TO INCLUDE CHARLESTON COUNTY...BERKELEY COUNTY...CHARLESTON HARBOR...AND AMZ350. THE ENVIRONMENT HAS SET UP MUCH LIKE WAS ANTICIPATED THIS MORNING. TEMPERATURES ACROSS SOUTHEAST GEORGIA HAVE WARMED INTO THE LOW 80S IN MANY AREAS WITH DEW POINTS IN THE LOW 70S. SURFACE BASED CAPE VALUES ARE IN THE 2000-2500 J/KG RANGE AND 0-3 KM SHEAR IS ON THE ORDER OF 30-35 KT. THE NEAR SURFACE FLOW IS BACKED TO MORE SOUTHEASTERLY WHICH IS ENHANCING THE STORM RELATIVE HELICITY VALUES INTO THE 200 RANGE. CURRENT RADAR TRENDS SHOW LINEAR CONVECTION JUST TO THE WEST WITH MORE DISCRETE CELLULAR DEVELOPMENT FURTHER SOUTH ACROSS THE NORTHERN EXTENT OF JAX/S FORECAST AREA. THE CONVECTIVE MODE WILL CONTINUE TO FAVOR LINEAR SEGMENTS AND WITH THE SHEAR/INSTABILITY COMBINATION EMBEDDED SUPERCELL ELEMENTS ARE EXPECTED. HI-RES MODEL RUNS SUCH AS THE HRRR CONTINUE TO SHOW AN ELEVATED MIXED LAYER SIGNATURE IN THE SOUNDINGS. DAMAGING WINDS CONTINUE TO BE THE PRIMARY THREAT...THOUGH LARGE HAIL CANNOT BE TOTALLY RULED OUT. THERE ALSO REMAINS THE THREAT OF BRIEF TORNADOES SPINNING UP WITHIN ANY QLCS SEGMENTS. TIMING IS LARGELY UNCHANGED...WITH THE CONVECTION REACHING THE SAVANNAH METRO AREA RIGHT NOW AND THEN WILL REACH THE CHARLESTON AREA AROUND 22Z-23Z. TONIGHT...THE LINE OF CONVECTION WILL PUSH EAST OF THE AREA AND OFFSHORE RIGHT AROUND MIDNIGHT. THEREAFTER...MODEL TIME HEIGHTS AND SOUNDING SHOWS NOTABLE MID/UPPER LEVEL DRYING AND THE REMAINDER OF THE NIGHT IS EXPECTED TO BE DRY. STRATUS WILL FILL IN OVERNIGHT AND OVERCAST SKIES WILL PREVAIL. ANOTHER VERY WARM NIGHT IS EXPECTED...WITH YET ANOTHER PERSISTENCE FORECAST FOR LOWS. THE FORECAST FEATURES MID TO UPPER 60S AGAIN. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... THE UPSTREAM LONGWAVE TROUGH WILL PUSH A STRONG COLD FRONT TOWARD THE REGION MONDAY. AFTER A RAIN-FREE MORNING...THE CHANCE FOR THUNDERSTORMS WILL INCREASE DURING THE AFTERNOON. DESTABILIZATION SUPPORTED BY FEATURING MLCAPES INCREASING TO 2000-3000 J/KG...FAIRLY UNIDIRECTIONAL 0-6 KM BULK SHEAR 40-50 KNOTS AND SOME DYNAMIC FORCING FOR ASCENT PROVIDED BY AN APPROACHING SHORTWAVE TROUGH ALOFT/LARGE SCALE HEIGHT FALLS PRODUCED BY THE PARENT LONGWAVE TROUGH WILL SUPPORT THE POTENTIAL FOR ANOTHER ROUND OF ORGANIZED THUNDERSTORMS PRODUCING SEVERE WEATHER. DOWNDRAFT CAPES AROUND 1500 J/KG AND DRIER AIR ALOFT WILL SUPPORT DAMAGING WIND GUSTS AND EVEN LARGE HAIL. THUNDERSTORM COVERAGE REMAINS UNCERTAIN MONDAY AFTERNOON/EVENING. WHILE ORGANIZED THUNDERSTORMS COULD PUSH INTO THE REGION FROM THE WEST...STRONG THUNDERSTORMS SOUTH OF THE REGION COULD LIMIT COVERAGE OVER THE REGION. ALSO POSSIBLE...STRONGEST THUNDERSTORMS COULD REMAIN JUST NORTH OF THE REGION. FOR NOW...CAPPED POPS AT 50 PERCENT OR LESS...HIGHEST INLAND/NORTH...BUT ADJUSTMENTS COULD YET BE REQUIRED. WILL CONTINUE TO HIGHLIGHT THE SEVERE WEATHER THREAT WITHIN THE HAZARDOUS WEATHER OUTLOOK. THE COLD FRONT WILL CROSS THE REGION MONDAY NIGHT. THE CHANCE FOR THE SHOWERS/THUNDERSTORMS WILL GRADUALLY WANE...AND THE POTENTIAL FOR SEVERE WEATHER WILL ALSO DIMINISH WITH DIURNAL STABILIZATION. MUCH DRIER HIGH PRESSURE WILL PREVAIL TUESDAY AND WEDNESDAY. HIGHS WILL AVERAGE IN THE MID TO UPPER 70S...AND LOWS IN THE 50S WILL BE COMMON TUESDAY NIGHT. GUIDANCE PULLS VARYING DEGREES OF MID/HIGH LEVEL MOISTURE INTO THE REGION WITHIN A ZONAL FLOW AHEAD OF AN APPROACHING COLD FRONT WEDNESDAY. WHILE CLOUD COVER SHOULD INCREASE...CONVECTIVE PRECIPITATION PRODUCED BY THE GFS APPEARS OVERDONE. THUS...HELD POPS BELOW 15 PERCENT WITH NO MENTION OF PRECIPITATION WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT. PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER AND WEAK COLD ADVECTION. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... MVFR CEILINGS HAVE RETURNED TO BOTH TERMINALS EARLY THIS AFTERNOON AND THE MAIN FORECAST ISSUE THROUGH THE EVENING WILL BE TIMING THUNDERSTORMS INTO THE FORECAST. BASED ON CURRENT RADAR TRENDS AND HI-RES MODEL GUIDANCE...IT LOOKS LIKE THUNDER WILL REACH KSAV AND IMPACT THE TERMINAL BETWEEN 20Z-22Z. HAVE GONE WITH IFR CONDITIONS IN THUNDER WITH GUSTY WINDS TO ALMOST 40 KT BASED ON SOME UPSTREAM OBSERVATIONS. AT KCHS...THUNDER WILL ARRIVE LATER AND IT IS UNCLEAR IF IT WILL BE AS STRONG AS IT IS EXPECTED AT KSAV. HAVE GONE WITH 22Z-00Z AT KCHS WITH IFR CONDITIONS AND SLIGHTLY LESSER WIND GUSTS. ONCE THE CONVECTION MOVE EAST OF THE TERMINALS THERE WILL BE A BIT OF A LULL UNTIL IFR CEILINGS ARE PROGGED TO RETURN AFTER MIDNIGHT. BOTH SITES GET PREVAILING IFR CEILINGS THROUGH THE LATE NIGHT...SCATTERING OUT MONDAY MORNING. EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS WITHIN SCATTERED SHOWERS/TSTMS POSSIBLE AT BOTH TERMINALS MONDAY AFTERNOON AND EVENING. OTHERWISE...VFR THROUGH THE PERIOD. && .MARINE... THIS EVENING AND TONIGHT...THE MAIN FORECAST ISSUE WILL BE THE LINE OF THUNDERSTORMS EXPECTED TO MOVE THROUGH THE LOCAL WATERS THIS EVENING AND THE FIRST PART OF TONIGHT. THESE STORMS COULD BE QUITE STRONG...PRODUCING 35 KT OR GREATER WINDS GUSTS...FREQUENT LIGHTNING...AND EVEN THE POTENTIAL FOR A TORNADIC WATERSPOUT. THE STORMS WILL IMPACT THE GEORGIA AND SOUTHERN SOUTH CAROLINA WATERS THROUGH ABOUT 10 PM...AND THEN MOVE OFF THE CHARLESTON COUNTY WATERS JUST AFTER MIDNIGHT. OTHERWISE...SOUTHERLY FLOW WILL PREVAIL AND THEN TURN MORE SOUTHWESTERLY LATE. OUTSIDE OF CONVECTION WINDS WILL TOP OUT IN THE 15-20 KT RANGE AND NO SMALL CRAFT ADVISORIES ARE ANTICIPATED. AHEAD OF AN APPROACHING COLD FRONT...SMALL CRAFT ADVISORY GUSTS FROM THE SOUTHWEST ARE POSSIBLE MONDAY AND MONDAY EVENING...ESPECIALLY ACROSS NEARSHORE WATERS. HOWEVER...SINCE THIS EVENT APPEARS MARGINAL...OPTED NOT TO RAISE A SMALL CRAFT ADVISORY. IN THE WAKE OF COLD FROPA...WINDS WILL SHIFT TOWARD THE NORTHWEST. TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH PRESSURE PREVAILS. && .TIDES/COASTAL FLOODING... THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ NEAR TERM...BSH SHORT TERM...SPR LONG TERM...JRL AVIATION...BSH/SPR MARINE...BSH/SPR TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
147 PM EDT SUN APR 19 2015 .SYNOPSIS... A WARM FRONT WILL LIFT INTO THE AREA TODAY...ACCOMPANIED BY AN UPPER LEVEL DISTURBANCE. A COLD FRONT WILL APPROACH THE AREA MONDAY... MOVING OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN TUESDAY THROUGH THURSDAY. A WEAK COLD FRONT WILL DROP THROUGH THE AREA THURSDAY NIGHT...THEN A STORM SYSTEM WILL AFFECT THE REGION NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY THIS AFTERNOON...QUICK UPDATE TO INCLUDE TORNADO WATCH 79 WHICH IS IN EFFECT THROUGH 8 PM. NO CHANGE TO PREVIOUS FORECAST THINKING AND PREVIOUS DISCUSSION FOLLOWS BELOW. LATE THIS MORNING...THE WARM FRONT PRECIPITATION THAT HAD BLOSSOMED EARLIER THIS MORNING ACROSS SOUTHEAST GEORGIA HAS DISSIPATED PRETTY RAPIDLY AS IT LIFTS TO THE NORTHEAST. AS SUCH...THE REST OF THE MORNING WILL BE RELATIVELY QUIET AHEAD OF THE MAIN FORECAST PROBLEM WHICH IS THE LARGE AREA OF CONVECTION CURRENTLY IMPACTING MUCH OF ALABAMA/GEORGIA/FLORIDA. OVERALL...THERE WILL BE LIMITED PRECIPITATION COVERAGE OUT AHEAD OF THE APPROACHING LINE OTHER THAN SCATTERED DISCRETE SHOWERS/THUNDERSTORMS THAT SHOULD DEVELOP RIGHT AS THE LINE PUSHES INTO THE WESTERN ZONES. CURRENTLY...THE RECENT RUNS OF THE HRRR SEEMS TO HAVE AN EXCELLENT HANDLE ON THE POSITION OF THE CONVECTION AND ITS AFTERNOON PROGRESSION SEEMS QUITE REASONABLE. REGARDING TIMING...THE HRRR IS RUNNING ABOUT AN HOUR OR TWO ON THE SLOW SIDE SO WE THINK THE LINE OF STORMS WILL BEGIN IMPACTING THE WESTERN ZONES IN THE 1-2PM WINDOW. THIS WOULD PUT THE LINE INTO THE SAVANNAH METRO AREA 3-5PM AND THEN THE CHARLESTON REGION BETWEEN 6-8PM. THE POTENTIAL FOR SEVERE WEATHER APPEARS TO BE INCREASING. UPSTREAM OFFICES HAVE BEEN ISSUING A MIXTURE OF SEVERE/TORNADO WARNINGS THIS MORNING WITH A NUMBER OF WIND DAMAGE REPORTS. BASED ON ITS LOCATION RELATIVE TO THE LINE AT 12Z...THE TAE MORNING SOUNDING IS LIKELY THE BEST SAMPLING OF THE APPROACHING NEAR STORM ENVIRONMENT. AS SUCH...WE EXPECT A STRONGLY SHEARED ENVIRONMENT WITH A NICE VEERING OF THE LOW LEVEL PROFILE AND CAPE VALUES INCREASING INTO THE 1500-2000 J/KG RANGE. IN FACT...THE TAE SOUNDING HAS A DISTINCT ELEVATED MIXED LAYER THAT ACTUALLY SHOWS UP WELL WHEN LOOKING AT HRRR SOUNDINGS LATER THIS AFTERNOON. ONE OF THE MORE TROUBLING ASPECTS IS THE POTENTIAL FOR A WINDOW OF CLEARING NOTED ON VISIBLE SATELLITE IMAGERY. AS THIS CLEARING HAS MOVED ACROSS SOUTH GEORGIA TEMPERATURES HAVE RISEN INTO THE UPPER 70S AND EVEN TO 80 WITHIN JUST AN HOUR. GIVEN LOW LEVEL THICKNESS VALUES AS THEY ARE...EVEN A BRIEF PERIOD OF SUN WILL LEAD TO A RAPID WARM UP AND INCREASE THE SURFACE DESTABILIZATION POTENTIAL. SO USING THE HRRR AND ITS SOUNDINGS AS THE BEST REPRESENTATION OF THE AFTERNOON NEAR STORM ENVIRONMENT...IT APPEARS WE ARE LOOKING AT CAPE VALUES AS HIGH AS 2500 J/KG...0-3 KM SHEAR OF 30-35 KT...AND SRH VALUES BETWEEN 150-250 THANKS TO THE SOUTHEAST BACKED LOW LEVEL FLOW. SUCH AN ENVIRONMENT WILL LIKELY FAVOR A CONVECTIVE MODE OF LINEAR SEGMENTS WITH EMBEDDED SUPERCELL ELEMENTS AND EVEN THE POTENTIAL FOR A DISCRETE SUPERCELL OR TWO. DAMAGING WIND GUSTS CONTINUES TO BE THE PRIMARY SEVERE WEATHER THREAT...BUT THE SHEAR AND LOW LEVEL VEERING WILL ALSO PROVIDE A TORNADO THREAT AS WELL. MUCH WILL BE DETERMINED BY HOW MUCH SUN CAN BREAK THROUGH AND TEMPERATURES WARM. ONE OTHER POTENTIAL THING TO WATCH IS THAT THE CURRENT SOUTHEAST WINDS COULD ADVECT IN A SLIGHTLY MORE STABLE MARINE ENVIRONMENT. HOWEVER...GIVEN THAT WE ARE OUT OF THE COOLEST SHELF WATER SEASON THIS IMPACT IS EXPECTED TO BE LIMITED. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... TONIGHT...THE SHORTWAVE WILL PUSH OFF THE COAST AND ELEVATED POPS DURING THE EVENING HOURS SHOULD DECREASE BELOW 15 PERCENT AS SOMEWHAT DRIER AIR AND TEMPORARY SUBSIDENCE DEVELOP OVERNIGHT INTO EARLY MONDAY. ANOTHER IN A SERIES OF VERY MILD OVERNIGHTS WITH TEMPS ONLY FALLING TO THE MID 60S ONCE AGAIN. THE LONGWAVE TROUGH WILL PERSIST TO OUR WEST ON MONDAY WHILE A SERIES OF POTENT SHORTWAVES LIFT NORTHEAST THROUGH THE LOCAL FORECAST AREA. A 145 KT SOUTHERN STREAM JET STREAK IS PROGGED TO SLIDE ALONG THE CENTRAL GULF COAST REGION DURING THE DAY...SPREADING A REGION OF ENHANCED UPPER LEVEL DIVERGENCE INTO SC/GA IN THE AFTERNOON. MODEL TIME SECTIONS SHOW CONSIDERABLE DRYING ABOVE 850 MB EARLY IN THE PERIOD...WITH PWATS DROPPING BELOW 1.25" BY MONDAY AFTERNOON. THE MAIN COLD FRONT WILL SLOWLY MOVE EAST DURING THE DAY...CROSSING THE REGION AT SOME POINT MONDAY EVENING. GIVEN THE DRY AIR ALOFT... CONSIDERABLE BREAKS IN THE CLOUDS AND COMPRESSIONAL HEATING AHEAD OF THE FRONT SHOULD HELP PUSH TEMPS INTO THE MID/UPPER 80S. THE BIG QUESTION ON MONDAY IS HOW MUCH CONVECTIVE COVERAGE DEVELOPS. THE DEEP DRY LAYER ABOVE THE SURFACE MAY LIMIT THE INITIAL CONVECTIVE DEVELOPMENT. HOWEVER...MODELS ARE HINTING AT AN UPSTREAM CONVECTIVE CLUSTER MOVING INTO WESTERN AREAS LATER IN THE AFTERNOON. THERMODYNAMICS AND KINEMATICS ARE QUITE IMPRESSIVE ON MONDAY. 40-50 KT OF 0-6 KM BULK SHEAR...CAPES OF 1500-2000 J/KG AND DOWNDRAFT CAPES 1000 TO 1500 J/KG. A FAIRLY ROBUST SEA BREEZE IS EXPECTED TO DEVELOP IN THE AFTERNOON GIVEN SUCH WARM TEMPS INLAND AND PREVAILING SOUTHERLY FLOW. THIS MAY COME INTO PLAY LATE IN THE DAY IF UPSTREAM CONVECTION MOVES IN FROM THE WEST. GIVEN THE SOMEWHAT DRIER TREND IN THE LATEST MODELS...WE MINIMIZED POPS MONDAY MORNING WITH VALUES INCREASING TO 30-40% IN THE AFTERNOON...ESPECIALLY ACROSS INTERIOR SC/GA. AS THE ACTIVITY AHEAD OF THE FRONT MOVES THROUGH OUR AREA IT SHOULD BE GRADUALLY WEAKENING. THEN SOME ADDITIONAL ACTIVITY...LIKELY WEAKER...COULD ACCOMPANY THE ACTUAL FRONT LATER IN THE EVENING OR OVERNIGHT. WE PLAN TO MAINTAIN SEVERE WEATHER POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT WITH DRY WEATHER AND SEASONABLE TEMPERATURES TUESDAY AND WEDNESDAY. HIGHS WILL CLIMB TO NEAR 80 BOTH DAYS WITH OVERNIGHT LOWS IN THE MID 50S. && .LONG TERM /MONDAY THROUGH SUNDAY/... A ZONAL PATTERN WILL EXIST MUCH OF THE PERIOD. A WEAK BACK DOOR COLD FRONT DROPS THROUGH THE AREA THURSDAY NIGHT. THE FRONT WILL STALL TO THE SOUTH BEFORE LIFTING BACK NORTH AS A WARM FRONT FRIDAY NIGHT AND SATURDAY. A PRONOUNCED SHORTWAVE EMBEDDED IN THE QUASI-ZONAL FLOW WILL MOVE THROUGH SATURDAY NIGHT ACCOMPANIED BY A COLD FRONT. PRECIPITATION POSSIBLE STARTING FRIDAY NIGHT AND CONTINUING INTO SATURDAY NIGHT. TEMPS WILL BE MODERATED BY INCREASING CLOUD COVER AND WEAK COLD ADVECTION. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... MVFR CEILINGS HAVE RETURNED TO BOTH TERMINALS EARLY THIS AFTERNOON AND THE MAIN FORECAST ISSUE THROUGH THE EVENING WILL BE TIMING THUNDERSTORMS INTO THE FORECAST. BASED ON CURRENT RADAR TRENDS AND HI-RES MODEL GUIDANCE...IT LOOKS LIKE THUNDER WILL REACH KSAV AND IMPACT THE TERMINAL BETWEEN 20Z-22Z. HAVE GONE WITH IFR CONDITIONS IN THUNDER WITH GUSTY WINDS TO ALMOST 40 KT BASED ON SOME UPSTREAM OBSERVATIONS. AT KCHS...THUNDER WILL ARRIVE LATER AND IT IS UNCLEAR IF IT WILL BE AS STRONG AS IT IS EXPECTED AT KSAV. HAVE GONE WITH 22Z-00Z AT KCHS WITH IFR CONDITIONS AND SLIGHTLY LESSER WIND GUSTS. ONCE THE CONVECTION MOVE EAST OF THE TERMINALS THERE WILL BE A BIT OF A LULL UNTIL IFR CEILINGS ARE PROGGED TO RETURN AFTER MIDNIGHT. BOTH SITES GET PREVAILING IFR CEILINGS THROUGH THE LATE NIGHT...SCATTERING OUT MONDAY MORNING. EXTENDED AVIATION OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED AT BOTH TERMINALS MONDAY AFTERNOON AND EVENING WITH BRIEF MVFR CEILING/VSBY RESTRICTIONS POSSIBLE. OTHERWISE VFR CONDITIONS EXPECTED. && .MARINE... A WARM FRONT WILL LIFT THROUGH THE WATERS TODAY...FOLLOWED BY INTENSIFYING SOUTH/SOUTHWEST FLOW. LIGHT AND VARIABLE WINDS EARLY THIS MORNING WILL BECOME SE PRIOR TO THE WARM FRONT WHICH WILL SHIFT FLOW SW TO S TONIGHT. WHILE SPEEDS INCREASE TONIGHT AND SEAS SLOWLY BUILD...THE AVERAGE SPEED COULD REACH ONLY 15 KT BY DAYBREAK OVER NEAR SHORE WATERS WITH SEAS 3 TO 4 FT. THE POTENTIAL EXISTS FOR THUNDERSTORMS WITH STRONG WINDS OVER THE WATERS THIS AFTERNOON EVENING. VERY HEAVY DOWNPOURS REDUCING LOCAL VSBYS BELOW 1 NM ARE ALSO POSSIBLE WITH THE STRONGEST STORMS MOVING OFFSHORE LATE IN THE DAY AND EARLY THIS EVENING. A PREVAILING SSW FLOW WILL EXIST MONDAY MORNING AS A COLD FRONT APPROACHES FROM THE WEST. THE GRADIENT WILL STRENGTHEN DURING THE AFTERNOON...ESPECIALLY ALONG THE COAST WHERE A STRONG SEA BREEZE DEVELOPS DUE TO MID/UPPER 80S TEMPS OVER LAND. THE LATEST GFS AND NAM MOS AT FOLLY BEACH SC SHOW SFC WINDS EXCEEDING 20 KT LATE MONDAY AFTERNOON WHEN THE SEA BREEZE IS STRONGEST. THIS SEEMS FAIRLY REASONABLE GIVEN THE PATTERN AND THE WARMER INLAND TEMPS EXPECTED. A SMALL CRAFT ADVISORY MAY EVENTUALLY BE REQUIRED FOR CHARLESTON HARBOR MONDAY AFTERNOON FOR WINDS/GUSTS IN THE 20-30 KT RANGE. A BRIEF PERIOD OF SMALL CRAFT ADVISORY CONDITIONS MAY DEVELOP OVER OFFSHORE WATERS MONDAY NIGHT AS THE COLD FRONT MOVES THROUGH AND WINDS GUST TO 25 KT WITH SOME 6 FT SEAS ALSO POSSIBLE. TUESDAY THROUGH FRIDAY LOOK FAIRLY QUIET OVER THE WATERS AS HIGH PRESSURE PREVAILS. && .TIDES/COASTAL FLOODING... THERE IS A CHANCE THAT THE HIGH TIDE COULD REACH OR SLIGHTLY EXCEED 7.0 FT MLLW ON CHARLESTON HARBOR THIS EVENING. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ NEAR TERM...BSH SHORT TERM...JRL LONG TERM...JRL AVIATION...BSH MARINE...JRL TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
508 PM CDT SUN APR 19 2015 .SHORT TERM... 319 PM CDT THROUGH MONDAY NIGHT... AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN THE RAIN. THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND SOUTHERN CANADA. CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON. THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR MORE INFO ON TUESDAY`S WINDS. KJB && .LONG TERM... 319 PM CDT TUESDAY THROUGH SUNDAY... MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS THROUGH THE FORECAST. LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS. EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * EAST TO NORTHEAST WINDS AROUND 10 KT THROUGH MID EVENING. * LIGHT TO MODERATE RAIN THROUGH MID-EVENING THEN BECOMING MORE SHOWERY. * QUICKLY LOWERING CIGS THROUGH SUNDOWN THEN GRADUALLY LOWERING THROUGH IFR CATEGORY...POSSIBLY EVEN TO LIFR BY 03Z. * GRADUALLY LOWERING VISIBILITY THROUGH THIS EVENING WITH IFR VISIBILITY LIKELY PREVAILING BY MID EVENING. * ANOTHER ROUND OF -SHRA PROBABLE EARLY MONDAY MORNING. * GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN. MTF/JEE //DISCUSSION...UPDATED 18Z... RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS ACROSS THE TERMINALS. WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST EARLY MONDAY MORNING. EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING. GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR. JEE //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM-HIGH IN WINDS. * HIGH IN RAIN TIMING. * MEDIUM-HIGH IN IFR CIG TIMING AND MEDIUM IN VISIBILITY TIMING. * HIGH IN IFR CIG DURATION. LOW-MEDIUM IN IFR VISIBILITY DURATION. MTF/JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 324 PM CDT AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30 KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE NEARSHORE WATERS DURING THE DAY. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...11 AM MONDAY TO 9 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
325 PM CDT SUN APR 19 2015 .SHORT TERM... 319 PM CDT THROUGH MONDAY NIGHT... AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN THE RAIN. THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND SOUTHERN CANADA. CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON. THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR MORE INFO ON TUESDAY`S WINDS. KJB && .LONG TERM... 319 PM CDT TUESDAY THROUGH SUNDAY... MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS THROUGH THE FORECAST. LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS. EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING. * RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS. * CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING. * SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY MONDAY MORNING. * GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN. JEE //DISCUSSION...UPDATED 18Z... RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS ACROSS THE TERMINALS. WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST EARLY MONDAY MORNING. EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING. GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING. * HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN OCCURRENCE AND PERSISTENCE OF IFR VSBY. * HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND PERSISTENCE. * HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN TIMING OF BACKING WINDS. * HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 324 PM CDT AS A TROUGH OF LOW PRESSURE AND SECONDARY LOW PRESSURE CENTER MOVE ACROSS THE GREAT LAKES REGION TONIGHT...WINDS WILL LIKELY BE VARIABLE AT TIMES. THIS WILL ESPECIALLY BE THE CASE OVER THE SOUTHERN HALF OF THE LAKE WHERE THE LOW PRESSURE SYSTEM IS EXPECTED TO MOVE THROUGH. IN THE NEAR TERM...EAST NORTHEAST WINDS WILL PREVAIL OVER THE LAKE WITH THE HIGHEST SPEEDS TO 30 KT OCCURRING OVER THE NORTHERN HALF AND WHILE 15 TO 25 KT WINDS ARE BEING OBSERVED OVER THE SOUTH...WITH SPEEDS EXPECTED TO SLIGHTLY DIMINISH TONIGHT. AS THIS TROUGH/LOW EXIT TO THE EAST ON MONDAY...STRONGER WESTERLY WINDS WILL DEVELOP. HIGHEST WINDS TO 30 KT WILL OCCUR ALONG THE NEARSHORE WATERS WHILE ONLY 15 TO 25 KT ARE LIKELY OVER THE OPEN WATERS. A SIMILAR SETUP IS EXPECTED ON TUESDAY BUT WITH SPEEDS SLIGHTLY HIGHER...AS TO 30 KT WILL LIKELY PREVAIL FOR BOTH LOCATIONS AND WITH EVEN GALES POSSIBLE ALONG THE NEARSHORE WATERS DURING THE DAY. RODRIGUEZ && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 PM CDT SUN APR 19 2015 .SHORT TERM... 319 PM CDT THROUGH MONDAY NIGHT... AFTER ANOTHER WARM EARLY AFTERNOON ACROSS MUCH OF THE REGION RAIN IS BEGINNING TO SPREAD NORTHWARD ACROSS SOUTHERN SECTIONS OF THE CHICAGO METRO AREA AS OF THIS WRITING. THIS ACTIVITY WILL CONTINUE TO OVERSPREAD THE REGION THROUGH THE AFTERNOON AND EVENING...WITH TEMPERATURES LIKELY TO DROP BACK INTO THE UPPER 50S AND LOW 60S IN THE RAIN. THE MID-LEVEL DISTURBANCE...AND THE ASSOCIATED SURFACE SYSTEM WILL QUICKLY SHIFT NORTHWARD OVER LOWER MICHIGAN OVERNIGHT...AND IT APPEARS THAT THE RAIN WILL BECOME MORE SHOWERY AND INTERMITTENT OR POSSIBLY JUST SOME DRIZZLE LATER THIS EVENING AND INTO THE EARLY MORNING ACROSS MUCH OF THE AREA AS THIS INITIAL MID LEVEL DISTURBANCE SHIFTS NORTH OF THE AREA AND SOME DRIER MID LEVEL AIR SHIFTS OVER THE SOUTHEASTERN HALF OF MY AREA. SOME ADDITIONAL RAIN SHOWERS ARE POSSIBLE AGAIN EARLY MONDAY WITHIN A REGION OF MID LEVEL DEFORMATION AND RAP AROUND MOISTURE ASSOCIATED WITH THE DEEPENING LOWER AND MID LEVEL LOW OVER THE UPPER GREAT LAKES REGION AND SOUTHERN CANADA. CONDITIONS SHOULD DRY OUT MONDAY AFTERNOON...WITH ONLY A SMALL CHANCE OF AN ADDITIONAL SHOWER DEVELOPING AS COLDER AIR ALOFT STEEPENS THE LOWER LEVEL LAPSE RATES. THE MAIN STORY DURING THE AFTERNOON WILL BE THE WINDS. WINDS ARE EXPECTED TO INCREASE OUT OF THE WEST-NORTHWEST DURING THE DAY AS STOUT SURFACE PRESSURE GRADIENT SETS UP OVER THE REGION AS THE SURFACE LOW DEEPENS TO AROUND 985 MB ACROSS ONTARIO MONDAY AFTERNOON. MODEL SOUNDINGS SUGGEST GOOD AFTERNOON MIXING TO AROUND 850 MB SHOULD ALLOW FOR GUSTS OF AROUND 30 KT AT TIMES...ESPECIALLY DURING THE AFTERNOON. THESE WIND GUSTS SHOULD ABATE MONDAY EVENING...BUT STRONG WINDS LOOK TO DEVELOP AGAIN ON TUESDAY. SEE LONG TERM DISCUSSION FOR MORE INFO ON TUESDAY`S WINDS. KJB && .LONG TERM... 319 PM CDT TUESDAY THROUGH SUNDAY... MAIN FORECAST CONCERNS/CHALLENGES ARE WITH BELOW NORMAL TEMPS THROUGH THE FORECAST. LARGE UPPER LEVEL CENTER WILL BE CENTERED ACROSS THE REGION AT THE START OF THE PERIOD...AND REMAIN SITUATED THROUGH MUCH OF THE WORK WEEK AS IT SLOWLY MOVES EAST. SEVERAL VORT LOBES ARE ANTICIPATED TO WRAP AROUND THIS UPPER LEVEL LOW ON TUESDAY AND WITH STEEPENING LAPSE RATES...EXPECT SKY COVER TO INCREASE THROUGH THE DAY WHILE SCATTERED SHOWERS BECOME POSSIBLE...ESPECIALLY ACROSS NORTHERN ILLINOIS. AS THIS OCCURS...LIKELY DEEP MIXING WITH STRONG FLOW ALOFT WILL ALLOW FOR ANOTHER WINDY DAY. GUIDANCE IS SUGGESTING THAT ADVISORY CONDITIONS COULD BE REACHED IN THE AFTERNOON...AND WILL NEED TO CONTINUE MONITORING THIS POTENTIAL. ANY REMAINING PRECIP AND CLOUD COVER SHOULD EXIT THE AREA TUESDAY NIGHT WITH DRY CONDITIONS EXPECTED. SOME GUIDANCE DEVELOPS A SWATH OF PRECIP OVER THE CWA LATE IN THE NIGHT INTO EARLY WEDNESDAY. HOWEVER...A MORE LIKELY SCENARIO AT THIS TIME WOULD BE FOR DRY CONDITIONS AND SO HAVE LEFT OUT ANY POPS AT THIS TIME. ONGOING CAA WILL MAKE FOR CHILLY CONDITIONS TUESDAY NIGHT...WITH LOW TEMPS IN THE 30S. IF PRECIP WERE TO OCCUR DURING THIS PERIOD...THESE COLDER CONDITIONS COULD SUPPORT THE POTENTIAL FOR AT LEAST A RAIN SNOW MIX ACROSS NORTHERN ILLINOIS. EXPECT DRY CONDITIONS WITH BELOW NORMAL TEMPS THROUGH THE REST OF THE FORECAST PERIOD...WITH FORECAST HIGHS IN THE 50S. COLD NIGHT TIME LOWS IN THE 30S COULD BECOME AN ISSUE LATE IN THE WORK WEEK AS HIGH PRESSURE IS ANTICIPATED TO MOVE OVERHEAD...WITH LIGHTER WINDS AND THE COLD TEMPS POSSIBLY CREATING A SETUP FOR FROST. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING. * RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS. * CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING. * SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY MONDAY MORNING. * GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN. JEE //DISCUSSION...UPDATED 18Z... RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS ACROSS THE TERMINALS. WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST EARLY MONDAY MORNING. EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING. GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING. * HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN OCCURRENCE AND PERSISTENCE OF IFR VSBY. * HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND PERSISTENCE. * HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN TIMING OF BACKING WINDS. * HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
248 PM CDT SUN APR 19 2015 .UPDATE... 952 AM CDT I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES. WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I RAISED HIGH TEMPERATURES TODAY. KJB && .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * EAST WINDS ARND 10 KT BCMG NORTH LESS THAN 10 KT THIS EVENING. * RAIN MOVING IN OVER THE NEXT 1-2 HOURS WITH MVFR VSBY. COULD HAVE PERIODS OF IFR VSBY WITH HEAVIEST SHOWERS. * CIGS LOWER TO IFR LATE THIS AFTN THROUGH EARLY MONDAY MORNING. * SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY MONDAY MORNING. * GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN. JEE //DISCUSSION...UPDATED 18Z... RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS ACROSS THE TERMINALS. WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST EARLY MONDAY MORNING. EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING. GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING. * HIGH CONFIDENCE IN PERIODS OF MVFR VSBY...LOW CONFIDENCE IN OCCURRENCE AND PERSISTENCE OF IFR VSBY. * HIGH CONFIDENCE IN IFR CIGS...MEDIUM CONFIDENCE TIMING AND PERSISTENCE. * HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN TIMING OF BACKING WINDS. * HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1237 PM CDT SUN APR 19 2015 .UPDATE... 952 AM CDT I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES. WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I RAISED HIGH TEMPERATURES TODAY. KJB && .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * EAST WINDS 10-14 KT BCMG NORTH LESS THAN 10 KT THIS EVENING. * RAIN ARRIVES 21-22Z WITH 5SM VSBY WITH HEAVIER SHOWERS. * CIGS LOWER TO MVFR LATE THIS AFTN THEN TO IFR THIS EVENING THROUGH EARLY MONDAY MORNING. * SCATTERED SHOWERS OVERNIGHT WITH ANOTHER ROUND OF -SHRA EARLY MONDAY MORNING. * GUSTY WEST WINDS WITH MAX GUSTS ARND 30 KT MONDAY AFTN. JEE //DISCUSSION...UPDATED 18Z... RAIN IS SLOWLY PUSHING NORTH AND IS JUST SOUTH OF I-80 AT THIS TIME. MVFR AND LOWER CIGS ARE OVER CENTRAL AND SOUTHERN IL AND INDIANA BUT ALSO PUSHING NORTH. ADJUSTED PRECIP AND CIG TIMING BASED ON RADAR AND SATELLITE TRENDS. MVFR VSBY WILL BE TIED TO THE HEAVIER RAIN SHOWERS...AND CIGS WILL LOWER TO MVFR LATE THIS AFTN AND THEN TO IFR THIS EVENING. ALL GUIDANCE MEMBERS SHOW IFR CIGS ACROSS THE TERMINALS. WILL EITHER SEE SCATTERED SHOWERS OR A BREAK IN RAIN AFTER MIDNIGHT TONIGHT WITH ANOTHER ROUND OF RAIN PUSHING WEST TO EAST EARLY MONDAY MORNING. EAST WINDS BCM NORTHEAST ARND 10 KT LATE THIS AFTN AND BACK TO NW BY 03Z. WINDS CONTINUE TO BACK TO WEST BY EARLY MONDAY MORNING. GUSTY WINDS FOLLOW THE BAND OF RAIN SHOWERS...WITH 20G30KT EXPECTED BY MONDAY AFTERNOON. THINKING THE GUSTY WINDS AND DRIER AIR WILL HELP CIGS LIFT LATE MONDAY MORNING AND AFTN...BUT HAVE MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN RAIN SHOWERS THIS AFTERNOON AND EVENING. * HIGH CONFIDENCE IN MVFR CIGS...MEDIUM CONFIDENCE IN MVFR CIG TIMING AND OCCURRENCE AND TIMING OF IFR CIGS. * HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT...MEDIUM CONFIDENCE IN TIMING OF BACKING WINDS. * MEDIUM CONFIDENCE IN HOW QUICKLY CIGS LIFT TO VFR MONDAY. * HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1229 PM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 1114 AM CDT SUN APR 19 2015 SFC LOW LIFTING NORTHWARD INTO THE REGION AND PUSHING PLENTY OF WAA RAIN AHEAD OF IT ACROSS THE FA. PLENTY OF PRECIP EXPECTED TODAY AND INTO TONIGHT, BUT MORE SCATTERED IN NATURE IN THE OVERNIGHT HOURS. SOME DRY AIR WORKING AROUND THE LOW AND ERODING SOME OF THE RAINFALL MAY BRING A BREAK IN THE RAINFALL BRIEFLY...BUT NOT ENOUGH TO PULL PRECIP ANYWHERE FOR LONG. HAVE MADE A FEW ADJUSTMENTS TO THE FORECAST, BUT NO MAJOR UPDATES ARE ANTICIPATED AT THIS TIME. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 328 AM CDT SUN APR 19 2015 LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER, SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING, THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO ARRIVE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 328 AM CDT SUN APR 19 2015 LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS. MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING. SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE 500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE UPPER 30S AND LOWER 40S. 00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY: HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY. ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY, WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1226 PM CDT SUN APR 19 2015 MODELS BRINGING THE SFC LOW UP AND THROUGH THE AREA WITHIN THE TAF PD. TWO MAJOR CONCERNS...VIS DROP AND LOW CIGS ASSOCIATED WITH THE PROLONGED RAIN. HAVE KEPT THE LOWER VIS/CIGS ON THE EASTERN TERMINALS. CONCERN ON THE WEST SIDE IS THE MODEL HINT AT A SECONDARY LINE OF PRECIP SHOWING UP WITH THE 500MB TROF LATER AS THE LOW PULLS OUT TO THE EAST. GUIDANCE NOT REALLY REFLECTING THAT WELL...AND WILL BE IN CONFLICT WITH SOME OF THE DRIER AIR BEING PULLED INTO THE WEST SIDE OF THE SYSTEM. CONFIDENCE LOWER FOR PIA AND SPI THAN THE OTHER SITES. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HJS SHORT TERM...BARNES LONG TERM...BARNES AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1119 AM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 1114 AM CDT SUN APR 19 2015 SFC LOW LIFTING NORTHWARD INTO THE REGION AND PUSHING PLENTY OF WAA RAIN AHEAD OF IT ACROSS THE FA. PLENTY OF PRECIP EXPECTED TODAY AND INTO TONIGHT, BUT MORE SCATTERED IN NATURE IN THE OVERNIGHT HOURS. SOME DRY AIR WORKING AROUND THE LOW AND ERODING SOME OF THE RAINFALL MAY BRING A BREAK IN THE RAINFALL BRIEFLY...BUT NOT ENOUGH TO PULL PRECIP ANYWHERE FOR LONG. HAVE MADE A FEW ADJUSTMENTS TO THE FORECAST, BUT NO MAJOR UPDATES ARE ANTICIPATED AT THIS TIME. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 328 AM CDT SUN APR 19 2015 LATEST WATER VAPOR IMAGERY CONTINUES TO SHOW CLOSED UPPER LOW OVER EASTERN COLORADO, WITH LEAD SHORT-WAVE ROTATING AROUND THIS FEATURE ACROSS ARKANSAS/LOUISIANA. AS THIS WAVE LIFTS NORTHWARD, PRECIP WILL EVENTUALLY SPREAD INTO CENTRAL ILLINOIS TODAY. 07Z/2AM RADAR MOSAIC SHOWS DRY CONDITIONS ACROSS THE ENTIRE KILX CWA: HOWEVER, SHOWERS ARE BEGINNING TO DEVELOP AND BECOME MORE WIDESPREAD FURTHER SOUTH ACROSS WESTERN KENTUCKY AND FAR SOUTHERN ILLINOIS. BASED ON RADAR TIMING TOOLS AND LATEST HRRR FORECAST, THINK SCATTERED SHOWERS WILL ARRIVE SOUTH OF I-70 OVER THE NEXT COUPLE OF HOURS, THEN WILL SPREAD NORTHWARD TOWARD THE I-74 CORRIDOR BY MIDDAY. HAVE ADJUSTED POPS TO ACCOUNT FOR THE SLOWER ARRIVAL OF PRECIP DURING THE MORNING, THEN HAVE GONE WITH CATEGORICAL POPS ACROSS THE BOARD THIS AFTERNOON. ASIDE FROM SOME SBCAPES OF AROUND 1000J/KG ACROSS THE FAR SE CWA, FORECAST SOUNDINGS REMAIN FAIRLY STABLE TODAY. AS A RESULT, AM EXPECTING MAINLY SHOWERS WITH JUST A FEW EMBEDDED THUNDERSTORMS. DUE TO CLOUD COVER AND PRECIP, HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS, WITH READINGS MAINLY IN THE 60S. WARMEST TEMPS OF AROUND 70 WILL BE FOCUSED ALONG/WEST OF THE ILLINOIS RIVER WHERE PRECIP WILL BE SLOWEST TO ARRIVE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 328 AM CDT SUN APR 19 2015 LEAD SHORT-WAVE WILL LIFT INTO NORTHERN ILLINOIS/INDIANA BY EARLY EVENING, LIKELY LEADING TO A TEMPORARY LULL IN THE SHOWERS. MEANWHILE, THE MAIN UPPER LOW WILL GET A SOLID PUSH EASTWARD AND WILL ARRIVE ACROSS ILLINOIS LATER TONIGHT INTO MONDAY MORNING. SHOWERS AND PERHAPS A THUNDERSTORM WILL ACCOMPANY THIS FEATURE, SO WILL CONTINUE LIKELY POPS TONIGHT THROUGH MONDAY MORNING. ONCE THE 500MB VORT MAX AND THE ASSOCIATED SURFACE COLD FRONT PASS TO THE EAST, RAIN CHANCES WILL COME TO AN END BY MONDAY AFTERNOON. THANKS TO A TIGHT PRESSURE GRADIENT BEHIND THE DEPARTING FRONT, STRONG W/NW WINDS GUSTING TO BETWEEN 25 AND 30 MPH WILL DEVELOP ON MONDAY. THE WINDS WILL SUBSIDE FOR A TIME MONDAY NIGHT, BUT WILL ONCE AGAIN INCREASE MARKEDLY DURING THE DAY TUESDAY. HIGH TEMPERATURES BOTH DAYS WILL REMAIN IN THE LOWER 60S, WHILE OVERNIGHT LOWS DIP INTO THE UPPER 30S AND LOWER 40S. 00Z APR 19 MODELS HAVE COME INTO MUCH BETTER AGREEMENT CONCERNING THE EXTENDED FORECAST, WITH CONSENSUS FEATURING A CHILLY AND LARGELY DRY WEEK AHEAD. BOTH THE GFS AND ECMWF INDICATE A WEAK COLD FRONT WILL PASS THROUGH CENTRAL ILLINOIS TUESDAY NIGHT INTO WEDNESDAY: HOWEVER, THEY DISAGREE ON HOW MUCH PRECIP IT WILL GENERATE. THE GFS IS SLIGHTLY WETTER AND FASTER WITH FROPA, WHILE THE ECMWF IS DRIER AND ABOUT 6 HOURS SLOWER WITH THE FRONT. DUE TO THE STRONG NORTHWESTERLY UPPER FLOW PATTERN IN PLACE ACROSS THE MIDWEST, THINK THE FASTER GFS IS THE WAY TO GO WITH TIMING, BUT THINK THE DRIER ECMWF IS BETTER WITH QPF AS DEEP MOISTURE WILL BE LACKING WITH THIS FEATURE. AS A RESULT, HAVE OPTED TO CARRY LOW CHANCE POPS EVERYWHERE TUESDAY NIGHT, THEN ONLY ACROSS THE SE CWA ON WEDNESDAY. ONCE THE FRONT PASSES, A COOL/CANADIAN AIRMASS WILL SETTLE INTO THE REGION FOR THE MIDDLE AND END OF THE WEEK. HIGH TEMPERATURES WILL STRUGGLE TO REACH THE 60 DEGREE MARK ON BOTH WEDNESDAY AND THURSDAY, WHILE LOWS DROP INTO THE 30S. COLDEST MORNING MAY END UP BEING FRIDAY MORNING, WHEN RIDGE OF HIGH PRESSURE IS OVERHEAD AND WINDS WILL BE LIGHTEST. WILL NEED TO KEEP AN EYE ON TEMPS, AS FROST ADVISORIES WILL BE POSSIBLE ACROSS PARTS OF CENTRAL/SOUTHEAST ILLINOIS LATER THIS WEEK. AFTER THAT, ANOTHER SYSTEM WILL APPROACH FROM THE SOUTHWEST BY THE END OF THE WEEK: HOWEVER, ITS INFLUENCE LIKELY WILL NOT BE FELT UNTIL FRIDAY NIGHT/SATURDAY AT THE EARLIEST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 542 AM CDT SUN APR 19 2015 MID AND HIGH CLOUDS WILL CONTINUE OVER THE AREA THIS MORNING, EFFECTING ALL TAF SITES UNTIL THE PCPN MOVES INTO THE SITES. WILL START ALL SITES WITH VCSH AS THE PCPN MOVES NORTHWARD AND INITIALLY SATURATES THE LOWER LEVELS, DURING THE MORNING HOURS. THEN BETWEEN 10AM AND NOON, PCPN WILL BECOME MORE DOMINATE AND STEADY. TIMING OF ONSET OF PCPN WAS TAKEN FROM A BLEND OF THE BUFKIT DATA, NAM12, HRRR, AND RADAR TRENDS. MVFR CIGS AND VIS WILL ARRIVE WITH THE RAIN AND CONTINUE THROUGH REST OF TAF VALID PERIOD. PCPN COULD LET UP SOME LATE THIS EVENING, SO HAVE ADDED ANOTHER LINE FOR VCSH AFTER THE BULK OF THE RAIN MOVES THROUGH, AND BEFORE THE NEXT BATCH ARRIVES LATE TONIGHT/EARLY TOMORROW MORNING. WINDS WILL BE EASTERLY TO START, BUT THEN BECOME SOUTHEASTERLY AS THE SYSTEM GET CLOSER TO THE SITES. WITH THE SURFACE LOW PRESSURE AREA MOVING RIGHT OVER THE TAFS, WINDS WILL BE VARIABLE, ENDING AT WEST TO SOUTHWEST LATER TONIGHT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HJS SHORT TERM...BARNES LONG TERM...BARNES AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1110 AM CDT SUN APR 19 2015 .UPDATE... 952 AM CDT I MADE SOME UPDATES TO THE FORECAST FOR TODAY TO RAISE TEMPERATURES AND PUSH OFF THE TIMING OF THE RAIN CHANCES. WATER VAPOR IMAGERY INDICATES OUR MID/UPPER LEVEL DISTURBANCE OF INTEREST FOR LATER TODAY NOW LIFTING NORTHWARD ACROSS WESTERN KENTUCKY. THIS FEATURE IS CURRENTLY SUPPORTING AN AREA OF NORTHWARD MOVING SHOWERS ACROSS SOUTHERN PORTIONS OF ILLINOIS AND INDIANA. THEREFORE...THIS AREA OF SHOWERS WILL GRADUALLY WORK NORTHWARD ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA DURING THE AFTERNOON. IT APPEARS THE THREAT FOR THUNDERSTORMS WILL BE VERY LOW WITH THIS ACTIVITY...WITH TRENDS SUGGESTING NO LIGHTNING STRIKES OVER THE PAST FEW HOURS...SO I HAVE REMOVED THE MENTION OF SUCH THIS AFTERNOON. IN ADDITION...WITH THE SLOWER ONSET OF PRECIP TODAY...IT APPEARS TEMPERATURES WILL BE ABLE TO WARM TO NEAR 70 IN MOST AREAS AWAY FROM LAKE MICHIGAN...SO I RAISED HIGH TEMPERATURES TODAY. KJB && .SHORT TERM... 340 AM CDT THROUGH MONDAY... UPPER AIR ANALYSIS EARLY THIS MORNING DEPICTS DEEP UPPER LEVEL LOW PRESSURE NOW PUSHING INTO WESTERN KANSAS. MULTIPLE VORT MAXES ARE ROTATING AROUND THE LOW. THE STRONGEST OF THESE EXIST IN TEXAS AND THROUGH THE CENTRAL PLAINS...WITH SOME SMALLER SCALE WAVES EXTENDING INTO EASTERN MO/FAR WESTERN IL WERE SOME SCATTERED THUNDERSTORMS WERE ONGOING. A NORTHERN STREAM SHORTWAVE IS ENTERING THE NORTHERN PLAINS WITH SOME SHOWERS OUT AHEAD OF IT AS WELL. AT THE SURFACE...THE COLD FRONT THAT PASSED THROUGH NORTHEAST ILLINOIS AND NW INDIANA SATURDAY HAS PUSHED INTO CENTRAL ILLINOIS...BUT HAS LIKELY COMPLETED ITS SOUTHWARD RETREAT AND HAS WASHED OUT OVER THE PAST FEW HOURS. OVER THE LOCAL AREA...MUCH DRIER NE FLOW EXISTS WITH DEWPOINTS IN THE MID TO UPPER 20S IN THE CITY TO NEAR 40 SOUTH...THOUGH DEWPOINTS ARE POOLING ALONG THE FRONT IN THE UPPER 40S JUST SOUTH OF THE LOT CWA. THE SURFACE LOW THAT IS EXPECTED TO DEVELOP FROM THE SOUTHERN STREAM SHORTWAVE IS ALSO TAKING SHAPE OVER THE SOUTHERN STATES WITH A WARM FRONTAL BOUNDARY EXTENDING FROM WESTERN ARKANSAS THROUGH THE LOWER TENNESSEE VALLEY. AN EXPANSION OF LOWER CLOUD TOPS ON IR IMAGERY ALONG AND AHEAD OF THE WARM FRONT IS OCCURRING. LOW LEVEL WARM/MOIST ADVECTION WILL CONTINUE ITS SLOW PROGRESSION NORTHWARD UNDER MODEST SOUTH/SOUTHEAST FLOW. DEEPER MOISTURE/LIFT REALLY HOLD OFF UNTIL THE AFTERNOON PERIOD ACROSS MOST OF THE AREA. A SOMEWHAT COMPLICATED EVOLUTION AS A MAIN SURFACE LOW CENTER IS FORECAST TO STRENGTHEN AS IT LIFTS NORTH THROUGH INDIANA TODAY THEN FURTHER STRENGTHEN TONIGHT INTO MONDAY WHILE SEVERAL ADDITIONAL SURFACE LOWS DEVELOP AND EVENTUALLY MERGE WITH THE MAIN LOW CENTER. THE SURFACE LOW WILL EVENTUALLY BECOME DRIVEN BY A COMBINATION OF THE SW FLOW AHEAD OF THE SOUTHERN STREAM UPPER LOW AND THE NORTHERN STREAM SHORTWAVE. OF NOTE LATER TODAY...EXPECT COVERAGE OF SHOWERS TO INITIALLY BE SLOW GIVEN THE DRIER AIR PLACE...BUT INCREASING ASCENT ALOFT...LOW LEVEL SSE ISENTROPIC ASCENT AHEAD OF THE LOW AND WRAPPING AROUND THE CLOSED CIRCULATION EXTENDING THROUGH 850 AND EVEN 700 MB COMBINED WITH MODEST LOWER LEVEL FGEN SHOULD ALLOW FOR A BLOSSOMING OF SHOWERS ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. THE HIGHEST PWAT AXIS EXPANDS ACROSS INDIANA TODAY BUT SHOULD GET WRAPPED INTO NE ILLINOIS. RAP MOST UNSTABLE CAPE VALUES RELATIVELY LOW BUT DO EXPAND FROM SE TO NW THIS AFTERNOON AND THIS COUPLED WITH THE PUNCH FROM THE DRY SLOT OF THIS SYSTEM MAY ENABLE A FEW T-STORMS AS WELL...SO SOME OF THE SHOWERS WILL HAVE A MODEST KICK TO THEM IN THE MODERATE/HEAVY RAINFALL DEPARTMENT. EXPECT THAT NORTH CENTRAL ILLINOIS MAY BE UNDER A BIT OF SQUEEZE PLAY FROM THESE TWO SYSTEMS...THUS WHILE SHOWERS ARE STILL EXPECTED...HIGHER CONFIDENCE EXISTS IN COVERAGE FARTHER EAST. THIS EVENING THE FIRST MAIN SHORTWAVE WILL BE PASSING NE WHILE THE MAIN SOUTHERN STREAM ENERGY PASSES EAST THROUGH THE OHIO VALLEY...AND THE NORTHERN STREAM SHORTWAVE LAGS BEHIND BACK IN MN/IA. THERE IS ALSO THE LOSS OF DEEPER MOISTURE...THEREFORE EXPECT SHOWERS TO TAPER/END/TURN TO DRIZZLE POSSIBLY OVERNIGHT FOR A TIME. THEN MONDAY MORNING WE GET THE COUPLED UPPER LEVEL FORCING FROM THE NORTHERN STREAM LOW AND SURFACE COLD FRONT WHICH WILL LIKELY BRING ANOTHER ROUND OF SHOWERS MONDAY MORNING. SHOWERS WILL EASE MONDAY AFTERNOON. IT WILL BE QUITE BREEZY/WINDY BEHIND THE FRONT ON MONDAY IN THE COLD ADVECTION REGIME. KMD && .LONG TERM... 340 AM CDT MONDAY NIGHT THROUGH SATURDAY... THE THEME OF THE EXTENDED WILL BE THE UNSEASONABLY COOL WEATHER. A HIGH AMPLITUDE PATTERN WILL BE IN PLACE WITH STRONG UPPER LEVEL RIDGING EXTENDING WELL NORTH INTO THE CANADIAN ROCKIES AND SIMILARLY HIGH AMPLITUDE RIDGING IN THE NORTH ATLANTIC. THAT LEAVES OUR NORTHERN STREAM SHORTWAVE FROM SUNDAY/MONDAY WITH NO WHERE TO GO. THIS WILL KEEP MUCH OF THE EASTERN HALF OF THE COUNTY...INCLUDING OUR REGION...UNDER COOL NORTHWEST FLOW. THIS PATTERN ALSO FAVORED STRONGLY SHEARED OUT AND ELONGATED VORT MAXES TO PIVOT THROUGH BRINGING PERIODS OF SHOWERS. WITH PWAT VALUES QUITE LOW IN THIS AIRMASS...MUCH OF THE PERIOD WILL BE DRY AND EVEN THE SHOWERS SHOULD NOT BE VERY STRONG. BUT MORE IMPORTANTLY...SEASONAL AVERAGE HIGHS/LOWS FOR LATE APRIL ARE THE LOWER 60S (MID 60S SOUTH) AND LOWER 40S RESPECTIVELY...AND MUCH OF THIS PERIOD WILL FEATURE HIGHS IN THE 50S AND LOWS IN THE MID 30S...POSSIBLY COOLER A NIGHT OR TWO IF WINDS ARE LIGHTER. TEMPERATURE ANOMALIES ARE NOT THAT EXTREME THOUGH...SO RECORD COLD IS NOT ANTICIPATED. KMD && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * EAST WINDS BETWEEN 10-15KT INTO THIS EVENING. * WEST WINDS GUSTING TO 20 KT TOMORROW. * RAIN OVERSPREADS TAF SITES LATER THIS AFTN THRU TONIGHT. MVFR VSBY UNDER HEAVIER SHOWERS. * LOW END MVFR CIGS DEVELOP...POSSIBLY IFR CONDS DEVELOP BY 3Z THRU DAYBREAK MON. * A SECOND ROUND OF RAIN ARRIVES EARLY MONDAY MORNING. JEE //DISCUSSION...UPDATED 12Z... EAST WINDS CONTINUE TO KEEP THE LOW LEVELS RELATIVELY DRY AND LACK OF LOW CLOUDS...HOWEVER MOISTURE IS CREEPING NORTH ACROSS SOUTHERN IL/IN. WINDS WILL OCCASIONALLY GUST TO 20KT THRU MIDDAY...THEN EXPECT WITH THE ABUNDANCE OF MOISTURE AND RAIN THE GUSTS MAY BECOME LESS FREQUENT WITH SUSTAINED WINDS INCREASING SLIGHTLY TO ARND 12-15KT. AS A LOW PRESSURE LIFTS NORTHEAST TOWARDS THE REGION TONIGHT...CIGS ARE EXPECTED TO LOWER TO MVFR AND LIKELY TO IFR CONDS WITH BASES ARND 800FT AGL BY 3Z. A FEW GUIDANCE MEMBERS SUGGEST CIGS MAY DIP FURTHER TO ARND 400FT AGL BY 6Z AS A BRIEF LULL IN THE PRECIP IS POISED TO LIFT OVERHEAD. AT THIS TIME WILL MENTION VCSH BY 6Z MON...WHICH MAY END UP AS DRIZZLE OR LGT RAIN. CIGS WILL REMAIN IFR THRU DAYBREAK MON...UNTIL A TIGHT GRADIENT RETURNS AND WINDS INCREASE FROM THE WEST/NORTHWEST. THIS SHUD HELP TO LIFT CIGS BACK TO MVFR AND EVENTUALLY VFR CONDS BY LATER MON. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN RAIN TIMING...MEDIUM-HIGH CONFIDENCE IN PRECIP COVERAGE THIS EVENING. MEDIUM CONFIDENCE IN PRECIP COVERAGE TONIGHT AND MONDAY MORNING. * MEDIUM CONFIDENCE IN WIND SPEED AND DIRECTION AFTER 18Z. * HIGH CONFIDENCE IN CIGS BCMG AT LEAST MVFR AND PSBLY IFR...MEDIUM CONFIDENCE IN TIMING. JEE //OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z... MONDAY NIGHT...MVFR BECOMING VFR. TUESDAY...SLGT CHANCE PM SHRA...BUT MAINLY VFR. GUSTY WEST WINDS. WEDNESDAY...SLGT CHANCE SHRA. MAINLY VFR. WEST-NORTHWEST WINDS. THURSDAY...VFR. NORTH-NORTHEAST WINDS. FRIDAY...MAINLY VFR. CHC PM SHRA. SATURDAY...MAINLY VFR. BEACHLER && .MARINE... 257 AM CDT LOW PRESSURE OVER THE CENTRAL PLAINS WILL SLOWLY LIFT NORTHEAST TOWARDS THE LOWER GREAT LAKES REGION TONIGHT/EARLY MON. GUIDANCE CONTINUES TO INDICATE THE GRADIENT WILL TIGHTEN ACROSS THE LAKE...HOWEVER THIS APPEARS TO BE MORE FOCUSED ALONG THE SOUTHERN TIP OF THE LAKE. WITH THE CONTINUED EASTERLY WINDS...IT IS POSSIBLE MARGINAL SMALL CRAFT CONDITIONS MAY DEVELOP FOR THE ILLINOIS SHORELINE LATER TODAY INTO TONIGHT. THE LOW PRESSURE WILL THEN APPROACH THE LAKE AND BRIEFLY WEAKEN THE GRADIENT EARLY MON. THEN AS THE LOW LIFTS NORTHEAST LATER IN THE DAY MON...IT WILL DEEPEN AND MERGE WITH ANOTHER LOW...WHICH WILL CREATE A TIGHT GRADIENT OVER THE LAKE AND INCREASING WEST/NORTHWEST TUE. AFTER TUE THE DOMINANT WIND DIRECTION WILL BE NORTHWEST THROUGH MID- WEEK...BEFORE RELAXING TO THE WEST. THIS WILL ALLOW HIGHER WAVES TO BE FOCUSED IN THE SOUTHERN HALF OF LAKE MICHIGAN THROUGH MID- WEEK. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
248 PM EDT SUN APR 19 2015 .SYNOPSIS... SHOWERS WILL OVERSPREAD THE REGION THIS EVENING AND CONTINUE THROUGH MONDAY. UNSEASONABLY COOL TEMPERATURES ARE EXPECTED FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH MONDAY/... DRY AIR SAMPLED BY THE 12Z UPPER AIR SOUNDING REVEALS A SUBSTANTIAL LAYER OF DRY AIR. THIS HAS KEPT THE RAIN AND CLOUDS AT BAY FOR MUCH OF THE DAY...ALLOWING FOR TEMPERATURES TO RISE QUICKLY ABOVE NORMAL. TEMPERATURE RISES HAVE BEEN AIDED...AT LEAST IN PART...BY DOWNSLOPING EASTERLY FLOW SUSTAINED AT 10-15KTS WITH GUSTS CLOSE TO 25KTS. TEMPERATURES THIS EVENING WILL DECREASE ACROSS THE SOUTH FIRST AS THE THICKER CLOUD COVER AND EVENTUAL RAIN SHOWERS MOVE IN. TIMING THE ONSET OF PRECIPITATION HAS BEEN PUSHED BACK AN HOUR OR TWO FOR MOST LOCATIONS TO ACCOUNT FOR THE DRY AIR IN PLACE. KEEPING CATEGORICAL POPS IN FOR THIS EVENING/EARLY TONIGHT...DESPITE SEVERAL OF THE LATEST HRRR RUNS CONTINUING TO SHOW CONSIDERABLE MOISTURE EROSION UPON ARRIVAL...RESULTING IN TRIMMING OF QPF GENERATION. ALL OTHER GUIDANCE INCLUDING THE VARIOUS OTHER HI-RES MODELS SHOW THE CURRENT SWATH OF RAIN ALONG THE WARM FRONT HOLDING TOGETHER THROUGH OUR AREA. TONIGHT THE DRY SLOT IN THE WARM SECTOR WILL RESULT IN A LULL IN PRECIPITATION THAT IS EXPECTED TO LAST THROUGH DAYBREAK. CLOUDS MAY DIMINISH TO THE POINT WHERE POCKETS OF CLEARING COULD AID THE MONDAY MORNING WARM-UP AS STRONG SOUTHEASTERLY FLOW VEERS SOUTHERLY. COLDER AIR ADVANCING EASTWARD ALOFT WILL RESULT IN INSTABILITY AND DRIVE THUNDERSTORM ACTIVITY ALONG AND AHEAD OF THE COLD FRONT. A SLIGHT RISK OF SEVERE THUNDERSTORMS IS INCLUDED FOR OUR AREA...WITH THE MAIN THREAT BEING DAMAGING WINDS. TAX && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... FRONT WILL BE IN OR JUST EAST OF THE RIDGES AT 00Z TUESDAY...WITH A SECONDARY COLD FRONT LAGGING BEHIND WITH THE UPPER LEVEL COLD AIR. ENOUGH MOISTURE AND STEEP ENOUGH LAPSE RATES REMAIN BEHIND THE IMMEDIATE SURFACE BOUNDARY TO KEEP SHRA/TSRA CHANCES GOING THROUGH MUCH OF THE NIGHT. DRIER AIR SHOULD ALLOW PRECIPITATION TO CEASE AREAWIDE BY 12Z. MODELS ARE IN GENERAL AGREEMENT THAT DECAYING MISSISSIPPI VALLEY SHORTWAVE GETS ABSORBED BY DEEPENING UPPER LOW...WHICH DROPS INTO THE NORTHERN GREAT LAKES BY 12Z TUESDAY. THIS LEADS TO A TROUGHING PATTERN FOR THE NORTHEAST U.S. WHICH LOOKS TO PERSIST FOR SOME TIME. CONFIDENCE IS HIGH IN THESE DETAILS. HOWEVER...TIMING OF INDIVIDUAL SHORTWAVES ROTATING AROUND BECOMES MORE PROBLEMATIC WITH TIME. MAIN VORT LOBE RESIDES IN OR NEAR OUR NORTHERN COUNTIES TUESDAY. THIS PLUS BETTER INSTABILITY LEADS TO HIGHER POPS IN THIS AREA TUESDAY AFTERNOON/EVENING. HELD OFF ON THUNDER FOR NOW WITH EQUILIBRIUM LEVELS MOSTLY BELOW 15K FEET...BUT THIS MAY HAVE TO BE REEVALUATED WITH COLD TEMPS ALOFT EXPECTED. A WEAK IMPULSE MAINLY AFFECTS THE SOUTHERN COUNTIES WITH A FEW SHRA TUESDAY NIGHT. THE NEXT...MORE ORGANIZED...FRONTAL BOUNDARY ARRIVES WEDNESDAY WITH BETTER RAIN CHANCES AREAWIDE. BEHIND THE FRONT...BOUNDARY LAYER MAY BE ABLE TO COOL SUFFICIENTLY TO ALLOW SNOWFLAKES TO MIX IN NORTH OF PIT LATE WEDNESDAY NIGHT...BUT NO ACCUMULATION IS FORESEEN. A GENERAL COOLING TREND IN TEMPERATURE WILL BE SEEN WITH VALUES SINKING BELOW NORMAL BY THE END OF THE PERIOD. CL && .LONG TERM /THURSDAY THROUGH SATURDAY/... BROAD UPPER TROUGHING WILL REMAIN OVER THE EASTERN CONUS THROUGH THE EXTENDED AND RESULT IN BELOW NORMAL TEMPERATURES EACH DAY ALONG WITH CLOUDY SKIES AND SLIGHT CHANCES FOR PRECIPITATION THROUGHOUT THE PERIOD AS SHORTWAVES TRANSITION THROUGH THE FLOW AND CAA ALOFT PERSISTS. CONFIDENCE IS HIGH IN THE GENERAL FORECAST AS MODELS HAVE BEEN FAIRLY CONSISTENT IN PROGGING THIS LONGWAVE PATTERN...REFLECTED IN LATEST RMOP AND MODTRENDS GUIDANCE. HOWEVER...CONFIDENCE IN TIMING OF ANY MORE SIGNIFICANT PERIODS OF PRECIPITATION IS RELATIVELY LOW. FORECAST MAX/MIN TEMPERATURES ARE NOT EXCEPTIONALLY COLD...BUT PERSISTENT AROUND 10 DEGREES BELOW NORMALS AS ENSEMBLE ANOMALIES ARE SHOWING TEMPS AND HEIGHTS ALOFT ONLY RANGING FROM 1-2 STANDARD DEVIATIONS BELOW NORMAL THROUGH THE PERIOD. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... HIGH CIRRUS CONTINUES TO MOVE SLOWLY ACROSS THE AREA...BUT NO RESTRICTIONS ARE ANTICIPATED UNTIL THE RAIN SHOWERS ASSOCIATED WITH THE WARM FRONT ARRIVE THIS EVENING. EXPECTING RAIN TO FALL OUT OF MOSTLY VFR CIGS INITIALLY...BUT HEADING INTO THE OVERNIGHT THE CIGS SHOULD CONTINUE THIER DESCENT TO MVFR. CEILINGS MAY BE BROKEN AS WE HEAD INTO MIDDAY MONDAY...WITH THUNDERSTORMS EXPECTED THROUGH AFTERNOON. GUSTY EAST-SOUTHEASTERLY FLOW WILL CONTINUE EVENING AND OVERNIGHT...GRADUALLY RELAXING THROUGH THE EARLY MORNING MONDAY. SURFACE FLOW WILL AGAIN INCREASE AS IT VEERS MORE SOUTHERLY MONDAY AFTERNOON. TAX .OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... RESTRICTIONS ARE POSSIBLE WITH A MID WEEK UPPER TROUGH. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
218 PM EDT SUN APR 19 2015 .SYNOPSIS... SHOWERS WILL OVERSPREAD THE REGION THIS EVENING AND CONTINUE THROUGH MONDAY. UNSEASONABLY COOL TEMPERATURES ARE EXPECTED FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH MONDAY/... DRY AIR SAMPLED BY THE 12Z UPPER AIR SOUNDING REVEALS A SUBSTANTIAL LAYER OF DRY AIR. THIS HAS KEPT THE RAIN AND CLOUDS AT BAY FOR MUCH OF THE DAY...ALLOWING FOR TEMPERATURES TO RISE QUICKLY ABOVE NORMAL. TEMPERATURE RISES HAVE BEEN AIDED...AT LEAST IN PART...BY DOWNSLOPING EASTERLY FLOW SUSTAINED AT 10-15KTS WITH GUSTS CLOSE TO 25KTS. TEMPERATURES THIS EVENING WILL DECREASE ACROSS THE SOUTH FIRST AS THE THICKER CLOUD COVER AND EVENTUAL RAIN SHOWERS MOVE IN. TIMING THE ONSET OF PRECIPITATION HAS BEEN PUSHED BACK AN HOUR OR TWO FOR MOST LOCATIONS TO ACCOUNT FOR THE DRY AIR IN PLACE. KEEPING CATEGORICAL POPS IN FOR THIS EVENING/EARLY TONIGHT...DESPITE SEVERAL OF THE LATEST HRRR RUNS CONTINUING TO SHOW CONSIDERABLE MOISTURE EROSION UPON ARRIVAL...RESULTING IN TRIMMING OF QPF GENERATION. ALL OTHER GUIDANCE INCLUDING THE VARIOUS OTHER HI-RES MODELS SHOW THE CURRENT SWATH OF RAIN ALONG THE WARM FRONT HOLDING TOGETHER THROUGH OUR AREA. TONIGHT THE DRY SLOT IN THE WARM SECTOR WILL RESULT IN A LULL IN PRECIPITATION THAT IS EXPECTED TO LAST THROUGH DAYBREAK. CLOUDS MAY DIMINISH TO THE POINT WHERE POCKETS OF CLEARING COULD AID THE MONDAY MORNING WARM-UP AS STRONG SOUTHEASTERLY FLOW VEERS SOUTHERLY. COLDER AIR ADVANCING EASTWARD ALOFT WILL RESULT IN INSTABILITY AND DRIVE THUNDERSTORM ACTIVITY ALONG AND AHEAD OF THE COLD FRONT. A SLIGHT RISK OF THUNDERSTORMS IS INCLUDED FOR OUR AREA...WITH THE MAIN THREAT BEING DAMAGING WINDS. TAX && .SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/... SHOWER COVERAGE WILL DECREASE OVERNIGHT AS UPPER LEVEL SUPPORT SHIFTS TO THE EAST AND A LARGE UPPER LEVEL DRY SLOT OVERSPREADS THE AREA. THE RESULTING SUBSIDENCE IS EXPECTED TO CONTINUE THROUGH MONDAY MORNING...AND MAY PROMOTE MODEST HEATING OF A RELATIVELY-MOIST BOUNDARY LAYER WITH 45-50KT OF SOUTHWEST FLOW ALOFT. A SECOND SHORTWAVE TROUGH IS PROJECTED TO MOVE QUICKLY NORTHEASTWARD AND CROSS THE REGION BY LATE DAY. LIFT IN ASSOCIATION WITH THAT DISTURBANCE WOULD AID CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH THIS SCENARIO. WIDESPREAD SEVERE THUNDERSTORMS ARE NOT EXPECTED OWING TO PROGNOSIS OF WEAK MID LEVEL LAPSE RATES. UNUSUALLY STRONG UPPER LOW PRESSURE IS FORECAST TO BUILD SEWD INTO THE GREAT LAKES REGION BY TUESDAY...WITH ITS ASSOCIATED COLD FRONT TO CROSS THE FORECAST AREA DURING THE MORNING. COLD ADVECTION BEHIND THE FRONTAL PASSAGE IS PROGGED TO PROVIDE INCREASED COVERAGE OF STRATOCU AND POSSIBLE LAKE ENHANCEMENT TO LIGHT PRECIPITATION...WITH THAT LIMITED TO THE NORTHERN ZONES WITH EXPECTATIONS OF WESTERLY FETCH AND DRY ADVECTION. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... BROAD UPPER TROUGHING WILL REMAIN OVER THE EASTERN CONUS THROUGH THE EXTENDED AND RESULT IN BELOW NORMAL TEMPERATURES EACH DAY ALONG WITH CLOUDY SKIES AND SLIGHT CHANCES FOR PRECIPITATION THROUGHOUT THE PERIOD AS SHORTWAVES TRANSITION THROUGH THE FLOW AND CAA ALOFT PERSISTS. CONFIDENCE IS HIGH IN THE GENERAL FORECAST AS MODELS HAVE BEEN FAIRLY CONSISTENT IN PROGGING THIS LONGWAVE PATTERN...REFLECTED IN LATEST RMOP AND MODTRENDS GUIDANCE. HOWEVER...CONFIDENCE IN TIMING OF ANY MORE SIGNIFICANT PERIODS OF PRECIPITATION IS RELATIVELY LOW. FORECAST MAX/MIN TEMPERATURES ARE NOT EXCEPTIONALLY COLD...BUT PERSISTENT AROUND 10 DEGREES BELOW NORMALS AS ENSEMBLE ANOMALIES ARE SHOWING TEMPS AND HEIGHTS ALOFT ONLY RANGING FROM 1-2 STANDARD DEVIATIONS BELOW NORMAL THROUGH THE PERIOD. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... HIGH CIRRUS CONTINUES TO MOVE SLOWLY ACROSS THE AREA...BUT NO RESTRICTIONS ARE ANTICIPATED UNTIL THE RAIN SHOWERS ASSOCIATED WITH THE WARM FRONT ARRIVE THIS EVENING. EXPECTING RAIN TO FALL OUT OF MOSTLY VFR CIGS INITIALLY...BUT HEADING INTO THE OVERNIGHT THE CIGS SHOULD CONTINUE THIER DESCENT TO MVFR. CEILINGS MAY BE BROKEN AS WE HEAD INTO MIDDAY MONDAY...WITH THUNDERSTORMS EXPECTED THROUGH AFTERNOON. GUSTY EAST-SOUTHEASTERLY FLOW WILL CONTINUE EVENING AND OVERNIGHT...GRADUALLY RELAXING THROUGH THE EARLY MORNING MONDAY. SURFACE FLOW WILL AGAIN INCREASE AS IT VEERS MORE SOUTHERLY MONDAY AFTERNOON. TAX .OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... RESTRICTIONS ARE POSSIBLE WITH A MID WEEK UPPER TROUGH. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1220 PM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 945 AM CDT SUN APR 19 2015 RAIN WILL CONTINUE TO AFFECT THE FORECAST AREA THROUGH THE DAY. HOWEVER...THERE WILL BE AN HOUR OR TWO WHEN NO RAIN IS OCCURRING AND TRIED TO ACCOUNT FOR THIS IN THE FORECAST. KEPT THE MAX TEMPS THE SAME FOR NOW...BUT WILL LOOK INTO LOWERING LATER TODAY. REST OF THE FORECAST IN THE BALLPARK. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 THE FOCUS REMAINS ON THE RAIN TODAY AND TONIGHT. REFINED THE PCPN CHANCES BY USING A BLEND OF THE RAP13 AND HRRR MODEL RUNS THROUGH THIS MORNING SINCE THE TWO MODELS SEEM TO BE DOING PRETTY WELL CAPTURING THE LOCATION OF THE CURRENT RAIN. DID NOT MAKE ANY DRAMATIC CHANGES TO RAINFALL. OVERALL...MUCH OF THE FORECAST AREA CAN EXPECT ABOUT 0.30 TO 0.75 INCHES OF RAINFALL THROUGH TONIGHT. AT 330 AM...AN AREA OF LOW PRESSURE WAS OVER THE BORDER BETWEEN SOUTH DAKOTA AND SW MINNESOTA. A FRONTAL BOUNDARY EXTENDED NORTHWARD TO ANOTHER AREA OF LOW PRESSURE IN SOUTHERN MANITOBA. THERE WAS AN UPPER LEVEL TROUGH OVER THE NORTHERN HIGH PLAINS AND SASKATCHEWAN/MANITOBA DIGGING AND DEEPENING TOWARDS THE NORTHERN PLAINS AND ONTARIO. A LARGE AREA OF RAIN WAS LIFTING TO NNE THROUGH THE SOUTHERN TWO THIRDS OF THE FORECAST AREA. THIS RAIN WAS ASSOCIATED WITH A BAND OF MID LEVEL FRONTOGENESIS AHEAD OF THE LOW NEAR THE SD/MN BORDER. THERE WAS ADDITIONAL RAIN IN EASTERN SOUTH DAKOTA AND NW MINNESOTA MOVING TO THE EAST IN THE WAKE OF THE TROUGH BOUNDARY AND AHEAD OF THE UPPER LEVEL TO THE WEST. THE NORTHLAND HAD CLOUDY SKIES WITH TEMPERATURES IN THE UPPER 30S TO MIDDLE 40S. THE NORTHLAND HAD LIGHT EASTERLY TO SOUTHEASTERLY WINDS. THIS MORNING...THE SURFACE LOW NEAR THE SD/MN BORDER WILL LIFT NE TO THE AITKIN AREA BY THIS AFTERNOON. THE SURFACE LOW IN SOUTHERN MANITOBA WILL DIG TO THE SE. THE RAIN OVER THE FORECAST AREA EARLY THIS MORNING WILL CONTINUE LIFTING TO THE NORTH WITH THE BAND OF MID LEVEL FRONTOGENESIS. PARTS OF THE NORTHERN FORECAST COULD PICK UP TO AROUND A HALF INCH OF RAIN THROUGH THIS MORNING. THE COLD FRONT IN NORTH DAKOTA WILL BEGIN TO MOVE INTO THE WESTERN FORECAST AREA LATE THIS MORNING. THIS AFTERNOON AND EVENING...THE TWO LOWS WILL GRADUALLY MERGE INTO ONE LOW OVER NW ONTARIO. CLOUDY AND COOL WEATHER IS EXPECTED WITH HIGHS RANGING FROM THE UPPER 40S OVER THE NORTH TO THE 50S OVER THE SOUTH. MOST OF THE AFTERNOON AND EVENING RAIN WILL BE OVER THE EASTERN FORECAST AREA AHEAD OF THE EASTWARD ADVANCING COLD FRONT. A DRY SLOT WILL MOVE INTO THE WESTERN FORECAST AREA...AND THERE COULD BE PARTIAL CLEARING IN THE SW FORECAST AREA. ALSO...A PROMINENT BAND OF LOW/MID LEVEL FRONTOGENESIS WILL SET UP OVER NW WISCONSIN THIS EVENING WHICH DEVELOP AND INTENSIFY A BAND OF RAIN OVER THAT AREA. THE UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA WILL DEEPEN AND DEVELOP INTO A WELL DEFINED UPPER LEVEL OVER SOUTHERN MANITOBA THIS AFTERNOON AND CONTINUE DEEPENING AS IT APPROACHES NORTHERN MANITOBA. LATER TONIGHT AND EARLY MONDAY...THE COLD FRONT WILL FINISH MOVING THROUGH THE FORECAST AREA. THE UPPER LEVEL LOW WILL CONTINUE DEEPENING OVER NW ONTARIO. THE LOW/MID LEVEL FRONTOGENETICAL BAND IN NW WISCONSIN SHOULD EXIT TO THE EAST BY AROUND DAWN. TEMPERATURES WILL DROP INTO THE MIDDLE AND LOWER 30S TONIGHT. THE SYNOPTIC LIFT FROM THE UPPER LEVEL LOW WILL LIKELY RESULT IN LIGHT RAIN AND SNOW MOVING INTO THE NW FORECAST AREA. LITTLE OF ANY SNOW ACCUMULATION IS EXPECTED SINCE MUCH OF IT SHOULD MELT...EITHER ON IMPACT OR LATER IN THE MORNING. MONDAY...IT WILL BE MUCH COOLER DAY WITH BLUSTERY NW WINDS. SUSTAINED WINDS OF 10 TO 20 MPH WILL DEVELOP BY THE AFTERNOON...AND THERE COULD BE GUSTS UP TO 30 MPH. THE 850 HPA TEMPERATURES WILL BE ABOUT -5 TO -6 DEGREES CELSIUS. HEAVY CLOUD COVER AND THE COOL NW FLOW WILL PREVENT HIGHS FROM GETTING MUCH HIGHER THAN THE LOW TO MIDDLE 40S. THERE WILL BE INCREASING CHANCES OF COLD RAIN SHOWERS AS THE UPPER LOW DEEPENS AND MOVES TO JUST NORTH OF KOOCHICHING COUNTY. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 342 AM CDT SUN APR 19 2015 A DEEP AREA OF LOW PRESSURE WILL SETTLE SOUTHWARD INTO THE LAKE SUPERIOR REGION MONDAY NIGHT AND TUESDAY. THE CLOSED H5 LOW WILL REACH WESTERN LAKE SUPERIOR BY TUESDAY AFTERNOON. NUMEROUS SHOWERS WILL ROTATE SOUTHWARD AROUND THE UPPER LOW...GENERALLY IN THE FORM OF SNOW SHOWERS AT NIGHT AND RAIN OR SNOW SHOWERS DURING THE DAY THROUGH THE MIDDLE OF THE WEEK. DEFINITELY COULD BE SOME SLUSHY ACCUMULATION AT TIMES...ESPECIALLY IN THE NORTH. WOULD NOT BE SURPRISED TO SEE A COUPLE EPISODES OF UP TO A COUPLE INCHES... FOLLOWED BY SOME PARTIAL TO FULL MELTING DURING THE DAY. THIS MASSIVE UPPER LEVEL TROUGH WILL EVENTUALLY LOSE ITS GRIP ON THE AREA FROM THE MIDDLE TO THE END OF THE WORK WEEK. THE GEM AND TO SOME EXTENT THE ECMWF ARE THE MOST AGGRESSIVE IN PUSHING THE UPPER TROUGH EASTWARD THROUGH THE END OF THE WEEK...WITH THE GEM BRINGING UPPER LEVEL RIDGING ALREADY INTO THE CWA BY 12Z FRIDAY. THE GFS IS MUCH SLOWER AND DEEPER WITH THE UPPER LEVEL LOW. STRONGLY FAVORING THE GEM/ECMWF SOLUTION...ESPECIALLY LATE IN THE WEEK AND INTO THE WEEKEND. HIGH TEMPERATURES WILL REMAIN ON THE COOL SIDE DURING THE WEEK...REACHING BACK INTO THE LOW TO MID 50S ON THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1220 PM CDT SUN APR 19 2015 CONDITIONS VARIED FROM LIFR TO MVFR ACROSS THE NORTHLAND WITH PERIODS OF RAIN/FOG/DRIZZLE MOVING THROUGH THE AREA. THESE CONDITIONS WILL PERSIST THROUGH THE AFTERNOON INTO TONIGHT. THE RAIN WILL BE MOST WIDESPREAD OVER EASTERN AREAS...ESPECIALLY NORTHWEST WISCONSIN TONIGHT. SOUTHWEST AREAS INCLUDING KBRD MAY GO VFR BRIEFLY LATER THIS EVENING...BUT AS COLDER AIR MOVES BACK IN ON THE BACKSIDE OF THE LOW...LOWER CEILINGS WILL ONCE AGAIN RETURN. TEMPERATURES MAY GET COLD ENOUGH FOR SOME SNOW OVER PORTIONS OF NORTHERN MINNESOTA LATER TONIGHT. GUSTY WEST/NORTHWEST WINDS WILL ALSO DEVELOP LATER IN THE PERIOD...ESPECIALLY ON MONDAY. && .PRELIMINARY POINT TEMPS/POPS... DLH 49 34 44 29 / 90 30 30 60 INL 49 32 40 28 / 100 40 60 60 BRD 56 35 43 31 / 80 20 40 40 HYR 58 37 46 30 / 90 80 30 60 ASX 58 37 47 32 / 90 80 20 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ142>147. && $$ UPDATE...GSF SHORT TERM...GROCHOCINSKI LONG TERM...DAP AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1239 PM CDT Sun Apr 19 2015 .UPDATE... Issued at 723 AM CDT SUN APR 19 2015 Made major adjustments to the forecast. Lowered PoPs considerably for the rest of the morning south and west of a h7 vorticity lobe that defines the back edge of showers over northern and into central MO...roughly along an arc from St. Joseph to Sedalia. Trend of the HRRR, RUC and even the NAM supports the above scenario. Convective cluster over north central OK may graze the far southern counties this afternoon so likely PoPs this area seems reasonable. So, for a good portion of today many areas will see little in the way of measurable rainfall. Still believe we`ll see a band of stratiform type rain tied to the post-frontal baroclinic zone/deformation zone that will slide ese across the CWA from late afternoon through this evening. && .SHORT TERM...(Today through Tuesday) Issued at 407 AM CDT SUN APR 19 2015 Today - Tonight: Today`s weather will be governed by the transition of an upper level closed low to an open wave. Latest water vapor satellite imagery shows the closed upper low has now shifted east into west central KS early this morning. A shortwave trough digging into the Northern High Plains will push this feature and its associated convection through the CWA today with the rain ending from west to east this evening. Scattered showers and isolated thunderstorms will accompany a couple mid level vorticity lobes as they rotate northeast across KS and MO. No severe storms are expected today as less than impressive MUCAPEs in the 400-800 J/kg range and bulk shear values around 25kts will limit the strength of the storms. Like yesterday a few cells could produce small hail during peak heating. Temperatures will again be negatively impacted by the convection and cloud cover. A more organized band of stratiform rain tied to post-frontal frontogenesis and an elongated deformation zone overspreads the region during the evening hours. Monday - Tuesday: The Northern Plains upper trough will gradually sharpen south and shift east on Monday with strong subsidence spilling southeast on the backside of the trough. Clearing skies will help offset cold air advection yielding slightly below average temperatures both days. The operational models are showing similar weak signals on Tuesday that we`ll need to start considering the chance of some shower activity. The models generate a series of weak strung out vorticity lobes stretching southeast from NE through MO. Moisture will be the main limiting factor so if any rain forms it will be light and scattered. .LONG TERM...(Wednesday through Saturday) Issued at 407 AM CDT SUN APR 19 2015 Slightly below normal temperatures will stretch through the latter half of the week as deep low pressure very slowly transitions SE across the Great Lakes, and northwest flow aloft ushers cooler temperatures into the region. At the same time a surface boundary will drift southward through Wednesday, leaving the forecast area in north to northeast surface flow and also helping to keep highs in the lower to mid 60s. A few light showers and isolated storms are possible over the southern tier of the CWA Wednesday and Wednesday night as the front heads south, then a period of drier conditions is expected on the north side of the boundary Thursday. Southerly surface flow will eventually return by the end of the work week ahead of a shortwave trough that will eject out of the desert southwest and into the Plains by Friday. Widely scattered showers and storms are possible as early as Friday afternoon, but are more likely Friday night as the upper trough passes over the CWA. Timing of this system is still a bit uncertain, and the probability of any embedded storms will depend on how quickly southerly flow and low- level moisture return to the region ahead of the shortwave trough. At this time, the southern track of the associated surface low and the environment in place ahead of the system suggests that the potential for strong storms is very low. The clouds and any rain associated with the system will keep temperatures down despite the transition to southerly flow, so have kept highs mainly in the lower 60s through the end of the work week and into the weekend. Current model trends show the wet weather clearing out by Saturday evening and a dry Sunday, but will have to watch the potential for Friday`s system to slow down and impact the coming weekend. && .AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon) Issued at 1237 PM CDT SUN APR 19 2015 Rain will stay out of the terminals for the next few hours, but by this evening rain, with some embedded thunder will move through the terminals. Expect the bulk of the rainy activity to only last a couple hours, with perhaps a few lingering hours of low ceilings and drizzle or very light rain. Expect winds to be gusty all night, but they should really pick up out of the NW by mid morning on Monday. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...MJ SHORT TERM...MJ LONG TERM...Laflin AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
129 PM CDT SUN APR 19 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT SUN APR 19 2015 THE UPPER LOW WHICH PRODUCED UP TO 52 INCHES OF SNOW IN COLORADO HAS DRIFTED EAST INTO WRN KS THIS MORNING. RAIN AND THUNDERSTORMS ARE FALLING UNDER THE LOW. A DEFORMATION ZONE OF RAIN AND ISOLATED THUNDERSTORMS IS WEAKENING ACROSS NCNTL AND SWRN NEB THIS MORNING. THE MODELS DRAG THIS AREA OF RAIN SOUTH AND OUT OF THE FORECAST AREA BY 15Z-18Z. A STRONG COLD FRONT WITH SCATTERED SHOWERS WILL DROP THROUGH THE FCST AREA THIS MORNING SETTING UP A WINDY AND COOL DAY. NORTHWEST WINDS WILL INCREASE TO 20 TO 30 MPH WITH GUSTS TO 40 MPH. THESE WINDS ARE ALREADY UNDERWAY IN THE PANHANDLE. THE STRONG WINDS BEND AROUND THE BLACK HILLS PRODUCING CONVERGENCE ACROSS SHERIDAN AND CHERRY COUNTIES. THE HRRR SHOWS SPRINKLES DEVELOPING BUT GIVEN THE VERY DRY AIR MOVING IN WITH DEW POINTS FALLING INTO THE 20S BY NOON...NO MEASURABLE RAINFALL WOULD BE EXPECTED. HIGHS TODAY RISE INTO THE 50S WITH PARTLY CLOUDY SKIES. THE MODELS ARE BRINGING IN COLD AIR ALOFT FROM AN UPPER LEVEL ACROSS MANITOBA. THE RESULT IS H700MB TEMPERATURES FALL TO AROUND -10C BY 21Z. SOME SUN IS EXPECTED BUT SKIES WOULD LIKELY CLOUD UP IN THE AFTERNOON WITH THE COLD AIR ALOFT. TONIGHT...THE UPPER LOW ACROSS WRN KS WILL LIFT INTO THE UPPER MIDWEST AND BE ABSORBED THE A DISTURBANCE ACROSS WRN ONTARIO TONIGHT. THIS WILL PULL PACIFIC HIGH PRESSURE INTO THE FCST AREA. GENERALLY CLEAR SKIES ARE EXPECTED WITH LOWS IN THE 20S TO LOWER 30S. WINDS STAY UP AT 10 TO 15 MPH NEAR ONEILL WHERE THE WARMER LOWS ARE EXPECTED. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 313 AM CDT SUN APR 19 2015 MONDAY INTO MID WEEK WILL SEE THE LOW PRESSURE SYSTEMS TO THE NORTHEAST AND EAST MERGE NEAR/NORTH OF THE GREAT LAKES. MEANWHILE NORTHWEST FLOW DOMINATES THE HIGH PLAINS AND AN UPPER LEVEL TROUGH DIGS ACROSS THE PACIFIC COAST. THE LOW PRESSURE SYSTEM TO THE NORTHEAST WILL DRAW SOME COOL AND DRY CANADIAN AIR TO THE REGION. TEMPERATURES WILL BE THE MAIN FOCUS THROUGH MID WEEK AND ARE TRICKY. THE DRY AIR MOVING SOUTH WILL ALLOW FOR DEW POINTS TO FALL INTO THE TEENS AND 20S...HOWEVER WITH THE RECENT HEAVY RAIN...THOUGHT MODELS ARE A TAD TO DRY SO DID RAISE SLIGHTLY BUT COULD SEE THEM BEING HIGHER...ESPECIALLY BY WED. SKIES WILL GENERALLY BE MOSTLY CLEAR...ALTHOUGH A COUPLE WEAK CLIPPERS MAY BRING A BRIEF INCREASE OF CLOUDS. WITH MOSTLY CLEAR SKIES AND DRY AIR TEMPS TO LIKELY FALL TO OR BELOW THE FREEZING MARK FOR THE FIRST FEW DAYS OF THE WEEK...UNLESS BL MOISTURE ENDS UP BEING MORE THAN EXPECTED FROM RECENT RAIN. MEANWHILE AFTERNOON SUN WILL HELP OFFSET THE COOL CONDITIONS AND BE ABLE TO AID IN MIXING THE BL...SEASONAL HIGHS /50S AND 60S/ EXPECTED. ONE CONCERN WITH HIGHS IS THE COOL TEMPS ALOFT...WHICH MAY RESULT IN SOME AFTERNOON CLOUDS DUE TO STEEP LAPSE RATES DEVELOPING. FAIRLY DRY AIR AT THE SFC SO NOTHING EXPECTED TO REACH THE GROUND. BY THE END OF THE WEEK THE WEST COAST TROUGH WILL BECOME AN OPEN WAVE CROSSING THE DESERT SW/4 CORNERS. A TRANSITION FROM NW TO SW FLOW WILL BRING A RETURN FOR WET WEATHER. MODELS NOT IN THE BEST OF AGREEMENT ON TIMING...BUT DO PUSH THE WAVE ONTO THE SOUTHERN/CENTRAL PLAINS BY THE WEEKEND. SHOULD SEE A BRIEF WINDOW OF RETURN MOIST SOUTHEASTERLY FLOW AHEAD OF THE WAVE. THIS TRACK AND THE INCREASE OF MOISTURE WILL FAVOR A CHANCE FOR RAIN...ALBEIT BETTER FOR SOUTHERN ZONES THAN NORTHERN ZONES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 116 PM CDT SUN APR 19 2015 THE LARGE SLOW MOVING STORM SYSTEM RESPONSIBLE FOR THE WEATHER OF LATE WILL CONTINUE TO MOVE AWAY FROM THE AREA. VFR CONDITIONS WILL BE THE RULE...WITH GUSTY NORTHWEST WINDS UP TO 35 KTS THIS AFTERNOON. WINDS WILL DIMINISH TONIGHT...BUT INCREASE ONCE AGAIN MONDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...MASEK AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1149 AM MDT SUN APR 19 2015 .AVIATION... 18Z TAF CYCLE STRONG BACKDOOR COLD FRONT HAS MOVED SOUTH ACROSS OF THE EASTERN PLAINS. N WIND GUSTS OF 30 TO 35 KT WILL CONTINUE FOR A COUPLE MORE HOURS AT RTN AND TCC BEFORE DIMINISHING. GUSTS AROUND 40 KT AT CAO AND CVN. THE BACKDOOR FRONT WILL HELP TRIGGER ISOLATED AFTERNOON AND EARLY EVE -SHRA AND -TSRA TODAY...MAINLY OVER THE SANGRE DE CRISTO MOUNTAINS AND ACROSS THE NE. MORE ISOLATED ACTIVITY POSSIBLE ALONG THE CENTRAL MOUNTAIN CHAIN AND THEIR E SLOPES. WILL CARRY VCTS AND VCSH AT LVS WITH NO MENTION AT THE OTHER TAF SITES. ISOLATED...HIGHER BASED CONVECTION POSSIBLE ACROSS THE SW MTS THIS AFTN. LATE TONIGHT THERE IS A POSSIBILITY OF SOME NEAR MVFR CIGS ACROSS THE E...INCLUDING LVS..TCC AND ROW. && .PREV DISCUSSION...913 AM MDT SUN APR 19 2015... .UPDATE... ADDED QUAY AND CURRY COUNTIES TO THE WIND ADVY FOR TODAY AND TWEAKED UP WIND SPEEDS OUT THERE. OTHERWISE NO CHANGES. && .PREV DISCUSSION...337 AM MDT SUN APR 19 2015... .SYNOPSIS... AN OVERALL UNSETTLED WEATHER PATTERN WILL CONTINUE FOR THE NORTHERN HIGH TERRAIN AND THE NORTHEAST PLAINS THROUGH ALL OF THIS WEEK. HIGH TEMPERATURES WILL SLOWLY TREND BACK TOWARD NORMAL THROUGH THE MIDDLE OF THE WEEK AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE WEST. DRY SOUTHWEST WINDS WILL INCREASE WEDNESDAY AND THURSDAY FOR WESTERN AND CENTRAL NEW MEXICO. THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN FOR ALL AREAS FRIDAY AS THE CORE OF AN UPPER LOW SLIDES OVERHEAD. COOLER TEMPERATURES WILL MOVE BACK INTO THE AREA BEHIND THIS SYSTEM...WHILE THE CHANCES OF PRECIPITATION CONTINUE OVER THE NORTH THROUGH NEXT WEEKEND. && .DISCUSSION... THE FINAL VESTIGES OF WRAP-AROUND PRECIP ARE IMPACTING THE FRONT RANGE OF COLORADO THIS MORNING AS EVIDENCED BY WIDESPREAD SHOWERS AND GUSTY NORTH WINDS. THIS ACTIVITY IS INDICATED BY THE 00Z/06Z NAM AND HRRR GUIDANCE TO CLIP NORTHEAST NM THIS MORNING. QPF WILL BE LIGHT WITH MOST AREAS REPORTING LESS THAN A TENTH. HIGHS AGAIN TODAY WILL BE BELOW NORMAL ALL AREAS...WITH READINGS 10-15F BELOW NORMAL FOR THE EAST. HIGH PRESSURE BUILDING DOWN THE FRONT RANGE TONIGHT BEHIND THE DEPARTING UPPER LOW WILL HELP FORCE LIGHT GAP WINDS INTO THE RIO GRANDE VALLEY LATE TONIGHT. ONE LAST UPPER VORT TRANSLATION WITHIN NW FLOW BEHIND THE DEPARTING WAVE WILL SLIDE OVER THE NORTHERN MTS AND NE PLAINS MONDAY. THIS WILL FORCE ANOTHER ROUND OF AFTERNOON SHOWERS NEAR THE HIGH TERRAIN AS FAR SOUTH AS I-40. AGAIN TEMPS WILL BE BELOW NORMAL WITH A SLIGHT TREND TOWARD NORMAL FOR THE FAR WEST. AN AMORPHOUS COMPLEX OF UPPER LEVEL LOW PRESSURE CURRENTLY TAKING SHAPE ALONG THE WEST COAST WILL BECOME THE NEXT WEATHER PLAYER FOR MID TO LATE WEEK. GUIDANCE SHOWS H5 HEIGHTS DEEPENING INTO A 562DM LOW TUESDAY OVER SOUTHERN CALIFORNIA WITH A WEAK SHORTWAVE RIDGE SLIDING OVER NM. THIS WILL TREND SHOWER AND WIND ACTIVITY DOWNWARD FOR NM. A 90-110KT 300MB JET AXIS THEN CARVES SOUTHWARD ALONG THE WEST COAST AND DEEPENS THE TROUGH INTO A TIGHTLY WOUND 550DM H5 LOW OVER SOUTHERN CALIFORNIA THROUGH THURSDAY. THIS WILL INCREASE MID LEVEL FLOW AND DEEPEN THE LEE SIDE TROUGH OVER EASTERN NM. WINDS AND TEMPS WILL INCREASE OVER THE STATE WITH SOME POSSIBLE MARGINAL FIRE WEATHER ISSUES NOTED WEDNESDAY AND/OR THURSDAY. BEYOND THURSDAY THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE TRANSLATION OF LOW PRESSURE OVER NM BY FRIDAY/SATURDAY AND INTO NEXT WEEK. THE GFS AND ECMWF OPEN THE WAVE AND SLIDE DISORGANIZED PRECIP OVER THE AREA...FOLLOWED BY A SERIES OF FAST MOVING WEAKLY DEFINED SHORTWAVE TROUGHS AND RIDGES. GUYER && .FIRE WEATHER... WHILE SOME POTENTIAL STILL REMAINS...AS IT CURRENTLY LOOKS THE RISK OF A RETURN OF CRITICAL FIRE WX CONDITIONS THURSDAY AND FRIDAY HAS DIMINISHED SOMEWHAT. A BACK DOOR FRONT MOVING ACROSS THE EASTERN PLAINS THIS MORN AND INTO THE AFTN WILL BRING INCREASINGLY STRONG AND GUSTY WINDS TO THE NE PLAINS AND TO A LESSER DEGREE THE EAST CENTRAL PLAINS THIS MORN. GUSTS NEAR 45 OR 50 MPH ARE POSSIBLE NEAR CLAYTON THIS MORN. WIND SPEEDS ARE EXPECTED TO DECREASE SOMEWHAT THIS AFTN. CRITICAL FIRE WX CONDITIONS NOT EXPECTED AS HUMIDITIES TO REMAIN TOO HIGH. AFTN TEMPS WILL ONLY BE SLIGHTLY COOLER TODAY AS COMPARED TO SATURDAY BEHIND THE FRONT. AS THE FRONT BACKS UP TO THE CENTRAL MTN CHAIN...EXPECT A FEW HIGH BASED SHOWERS AND THUNDERSTORMS TO DEVELOP DUE TO UPSLOPE FLOW...MORE SO ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO MTNS AND LESS SO FARTHER SOUTH. HUMIDITY RECOVERIES TONIGHT WILL BE GOOD TO EXCELLENT MOST AREAS OUTSIDE OF WEST CENTRAL AND SW NM WHERE FAIR TO GOOD RECOVERIES TO BE THE RULE. LOW TEMPS WILL BE A LITTLE ABOVE NORMAL WEST AND CENTRAL...A BIT BELOW EAST. HIGH TEMPS ON SUNDAY WILL REMAIN BELOW NORMAL ACROSS THE EAST DUE TO THE FRONTAL PASSAGE...THOUGH WILL BE INCHING UP TOWARD NORMAL ACROSS THE WEST. LATER MON...WEAK RIDGE ALOFT WILL DEVELOP ACROSS WESTERN NM...THOUGH ENOUGH RESIDUAL MOISTURE WILL BE AROUND TO TRIGGER A FEW HIGH BASED BUILDUPS AND VIRGA IN THE AFTERNOON HOURS. A FEW SPRINKLES MAY ACTUALLY REACH THE GROUND ACROSS THE NORTHERN HIGH TERRAIN...THOUGH THE BIGGER CONCERN MAY BE ERRATIC WIND GUSTS WITH ANY VIRGA ACROSS WESTERN NM. OTHERWISE TEMPS SHOULD WARM TO AROUND 5 DEGREES OF NORMAL EAST...VERY CLOSE TO NORMAL WEST. THE BACK DOOR COLD FRONT EARLIER SCHEDULED TO ARRIVE LATER MON NIGHT INTO TUE MORN HAS BEEN MARGINALIZED AND IN SOME MODELS ELIMINATED FROM THE SCENE COMPLETELY. STILL MAY BE JUST ENOUGH MOISTURE AND WEAK UPSLOPE TO CREATE A FEW SHOWERS AND THUNDERSTORMS TUE AFTN WITH AID OF AFTN HEATING. WED LOOKS TO BE BREEZY IN MANY AREAS...BUT FOR THE MOST PART THE STRONGEST WINDS STILL ARE EXPECTED TO ARRIVE THU AND FRI. BUT CRITICAL CONDITIONS HAVE SHRUNK SIGNIFICANTLY THU AND DO NOT APPEAR AT ALL FOR FRI. THIS MAY ONLY BE A TEMPORARY REDUCTION AS FCST MODELS SEEM TO BE IN TRANSITION AGAIN IN THEIR DEPICTION OF UPPER LVL LOW PRESSURE EVOLUTION OFF TO OUR WEST. THE BACK DOOR FRONT WILL BE REINFORCED ACROSS NE NM AND SOME THUNDERSTORMS MAY DEVELOP THERE THU AFTN. NO VENTILATION ISSUES ARE EXPECTED FOR THE NEXT 6 DAYS...WITH MAINLY VERY GOOD TO EXCELLENT VENT RATES EXPECTED...THOUGH FAR NORTHEAST NM MAY DROP INTO THE FAIR OR GOOD CATEGORIES MID TO LATE WEEK. SAT MAY SEE SOME EROSION OF VENTILATION RATES. 43 && .ABQ WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 4 PM MDT THIS AFTERNOON FOR THE FOLLOWING ZONES...NMZ530-534-535. && $$ 40
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
622 PM EDT SUN APR 19 2015 .SYNOPSIS... A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE LATE WEEK AND INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 555 PM SUNDAY...TORNADO WATCH NUMBER 82 THRU 11 PM REMAINS IN EFFECT FOR THE ILM SC CWA...PLUS ROBESON COUNTY OF THE ILM NC CWA. BROKEN LINE OF STRONG TO SEVERE THUNDERSTORMS IS ON THE WESTERN DOORSTEPS OF THE ILM CWA AT THE MOMENT. POPS HAVE BEEN RE-ADJUSTED THRUOUT THIS EVENING TO TAKE INTO ACCOUNT OF THE TIMING AND PROGRESSION OF THIS LINE AS IT TRAVERSES THE ILM CWA. AT THIS POINT...THE CUMULATIVE THINKING IS THAT THE CONVECTION WILL WEAKEN TO BELOW SEVERE LIMITS BY THE TIME IT PROGRESSES ACROSS THE ILM NC COUNTIES LATER THIS EVENING AND OVERNIGHT AND THEREFORE A WATCH IS WAS NOT PLANNED AT THIS TIME. PREVIOUS........................................................ AS OF 315 PM SUNDAY...AS LIGHT STRATIFORM RAINFALL PULLS NE AWAY FROM THE REGION THIS AFTERNOON...A MORE ORGANIZED BAND OF SHOWERS AND TSTMS WILL MOVE INTO NE SC 6 PM - 7 PM...AND INTO SE NC IN THE MIDDLE AND LATE EVENING. THIS IS APT TO BRING SIGNIFICANTLY MORE RAINFALL AMOUNTS TO THE AREA TONIGHT. SATELLITE DERIVED SENSORS OF PRECIPITABLE WATERS SHOW A LARGE SWATH OF 46MM/1.81 INCH PWATS MOVING INTO THE AREA THAT WILL HELP FUEL THE CONVECTION. SEVERAL ISOLATED OR DISCREET CELLS MAY ALSO FIRE AHEAD OF THE ORGANIZED RAIN AREA AFTER THE STRATIFORM RAIN HAS CLEARED. SEVERAL RECENT NEAR TERM MODELS SHOWS THE BULK OF RAINFALL MOVING NE OF SE NC AFTER 5Z/1AM. THE ORGANIZED NATURE OF THIS FEATURE IF HELD INTACT WILL INTRODUCE A SLIGHT CHANCE OF WIND DAMAGE OR HAIL TONIGHT. MINIMUMS TONIGHT WILL NOT FALL MUCH BELOW THE MIDDLE 60S EVEN IN RAIN COOLED LOCATIONS AS DEWPOINTS REMAIN ELEVATED. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...THE CWA WILL BE IN A RATHER WARM AND BLUSTERY SOUTHWEST FLOW AT THE BEGINNING OF THE PERIOD...IN BETWEEN A DEPARTING WARM FRONT TO THE NORTHEAST AND A COLD FRONT ACROSS THE TENNESSEE VALLEY. THIS FRONT MOVES STEADILY ACROSS THE SOUTHEAST DURING THE DAY AND SHOULD BE JUST ACROSS OUR WESTERN COUNTIES BY 0000 UTC TUESDAY. SEVERE PARAMETERS STILL LOOK CONDUCIVE FOR AN EVENT WITH ADEQUATE INSTABILITY AND SHEAR. HOWEVER HIGH RESOLUTION GUIDANCE IS SHOWING A LACK OF ACTIVITY WITH THE FRONT. THE MET HAS SIX HOUR POPS IN THE SINGLE DIGITS FOR THE 18-00 UTC TIME FRAME IN LBT AND ILM. THE GFS REMAINS MORE BULLISH WITH SCATTERED ACTIVITY AHEAD OF A CONVECTIVE LINE. WILL MAINTAIN THE CHANCE POPS AND FINE TUNE FOR THE TIMING FOR LATE AFTERNOON INTO THE EVENING. SPC MAINTAINS THE SLIGHT RISK FOR THE AREA CITING THE UNCERTAINTY. BEYOND THIS HIGH PRESSURE BUILDS IN FOR A NICE TUESDAY AND PEACEFUL WEDNESDAY MORNING. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...HIGH PRESSURE BOTH MOVES OFFSHORE AND WEAKENS CONSIDERABLY. PAIR THIS WITH ZONAL MID FLOW AND THE AFTERNOON SHOULD BE SEASONABLE AND RAIN-FREE WITH A FAIR AMOUNT OF SUNSHINE. THE APPROACH OF A COLD FRONT WILL YIELD A SMALL RISE IN POPS ON THURSDAY OR POSSIBLY EVEN WEDNESDAY NIGHT. THIS SLOW MOVING BOUNDARY MOVES THROUGH ON THURSDAY BUT WILL HAVE TO DEAL WITH MIDLEVEL DOWNSLOPING PREVENTING DEEP MOISTURE. THE FRONT STALLS SOUTH OF THE REGION POSSIBLY CLOSE ENOUGH FOR THE MAINTENANCE OF LOW END POPS. SOME DEEPER MOISTURE AND MORE MEANINGFUL RAIN CHANCES MAY MATERIALIZE OVER THE WEEKEND AS THE FRONT REMAINS TO OUR SOUTH BUT SOME WEAK MID LEVEL IMPULSES WORK TO PROVIDE LIFT ATOP SOME LOW LEVEL ISENTROPIC UPGLIDE. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/... AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z. WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE AFTER THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 555 PM SUNDAY...TOR WATCH 82 AFFECTS THE ILM SC WATERS THRU 11 PM. THE MARINE BOUNDARY LAYER OVER THE COOLER SHELF WATERS WILL ACT TO WEAKEN CONVECTION AS IT REACHES AND MOVES ACROSS ALL WATERS DURING THIS EVENING. THE STRONGER STORMS THIS EVENING THAT AFFECT THE ILM SC WATERS COULD PRODUCE SMW CRITERIA BRIEF GALE FORCE WIND GUSTS OR WATERSPOUTS. OTHERWISE...THE MAJORITY OF THE CONVECTION WILL PRODUCE MWS CRITERIA WINDS AND LIGHTNING. PREVIOUS........................................................ AS OF 315 PM SUNDAY...SEAS SLOWLY ON THE RISE IN THE MODERATE ONSHORE WIND FLOW AND 3-5 FOOT SEAS EXPECTED OVERNIGHT. SEVERAL TSTMS ARRIVING FROM THE SW TONIGHT MAY PRODUCE LOCALLY HIGHER WINDS AND SEAS...AND SEVERAL SPECIAL MARINE WARNINGS MAY BE NEEDED FOR TONIGHT WITH CLOUD TO SEA LIGHTNING POSING AN ADDITIONAL HAZARD. WINDS WILL VEER TO S AND SW OVERNIGHT WHICH WILL HELP TO LIMIT WAVE GROWTH AND A SMALL CRAFT ADVISORY IS NOT PLANNED ALTHOUGH AN EXERCISE CAUTION STATEMENT COULD BE NEEDED. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...A SOUTHWEST FLOW OF 10-15 KNOTS INITIALLY WILL INCREASE TO 15-20 BY THE END OF THE DAY MONDAY AS A FRONT MOVES CLOSER FROM THE WEST. THE FRONT FINALLY CROSSES THE WATERS EARLY TUESDAY MORNING WITH A MODEST WESTERLY FLOW OF 10-15 KNOTS IN ITS WAKE. SMOOTH SAILING FOR THE REMAINDER OF THE PERIOD WITH WINDS TEN KNOTS OR LESS FROM THE WEST NORTHWEST AND SEAS OF 2-4 FEET. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 PM SUNDAY...WEDNESDAY BRINGS NEARLY MINIMAL WIND AND SEAS DUE TO HIGH PRESSURE MOVING OVERHEAD. WINDS THOUGH LIGHT WILL VEER CONSIDERABLY AS THE DAY PROGRESSES UNTIL A S TO SW FLOW BECOMES PREDOMINANT LATE IN THE DAY OR AT NIGHT. MORE VEERING IS SLATED FOR THURSDAY AS A COLD FRONT APPROACHES AND VERY SLOWLY CROSSES THE WATERS. WITH THIS FRONT STALLING NEARBY TO OUR SOUTH ON FRIDAY A LIGHT NORTHERLY FLOW WILL BE MAINTAINED. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...DCH/MJC SHORT TERM...SHK LONG TERM...MBB AVIATION...MJC/SHK/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
319 PM EDT SUN APR 19 2015 .SYNOPSIS... A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE LATE WEEK AND INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 315 PM SUNDAY...AS LIGHT STRATIFORM RAINFALL PULLS NE AWAY FROM THE REGION THIS AFTERNOON...A MORE ORGANIZED BAND OF SHOWERS AND TSTMS WILL MOVE INTO NE SC 6 PM - 7 PM...AND INTO SE NC IN THE MIDDLE AND LATE EVENING. THIS IS APT TO BRING SIGNIFICANTLY MORE RAINFALL AMOUNTS TO THE AREA TONIGHT. SATELLITE DERIVED SENSORS OF PRECIPITABLE WATERS SHOW A LARGE SWATH OF 46MM/1.81 INCH PWATS MOVING INTO THE AREA THAT WILL HELP FUEL THE CONVECTION. SEVERAL ISOLATED OR DISCREET CELLS MAY ALSO FIRE AHEAD OF THE ORGANIZED RAIN AREA AFTER THE STRATIFORM RAIN HAS CLEARED. SEVERAL RECENT NEAR TERM MODELS SHOWS THE BULK OF RAINFALL MOVING NE OF SE NC AFTER 5Z/1AM. THE ORGANIZED NATURE OF THIS FEATURE IF HELD INTACT WILL INTRODUCE A SLIGHT CHANCE OF WIND DAMAGE OR HAIL TONIGHT. MINIMUMS TONIGHT WILL NOT FALL MUCH BELOW THE MIDDLE 60S EVEN IN RAIN COOLED LOCATIONS AS DEWPOINTS REMAIN ELEVATED. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...THE CWA WILL BE IN A RATHER WARM AND BLUSTERY SOUTHWEST FLOW AT THE BEGINNING OF THE PERIOD...IN BETWEEN A DEPARTING WARM FRONT TO THE NORTHEAST AND A COLD FRONT ACROSS THE TENNESSEE VALLEY. THIS FRONT MOVES STEADILY ACROSS THE SOUTHEAST DURING THE DAY AND SHOULD BE JUST ACROSS OUR WESTERN COUNTIES BY 0000 UTC TUESDAY. SEVERE PARAMETERS STILL LOOK CONDUCIVE FOR AN EVENT WITH ADEQUATE INSTABILITY AND SHEAR. HOWEVE HIGH RESOLUTION GUIDANCE IS SHOWING A LACK OF ACVITITY WITH THE FRONT. THE MET HAS SIX HOUR POPS IN THE SINGLE DIGITS FOR THE 18-00 UTC TIME FRAME IN LBT AND ILM. THE GFS REMAINS MORE BULLISH WITH SCATTERED ACTIVITY AHEAD OF A CONVECTIVE LINE. WILL MAINTAIN THE CHANCE POPS AND FINE TUNE FOR THE TIMING FOR LATE AFTERNOON INTO THE EVENING. SPC MAINTAINS THE SLIGHT RISK FOR THE AREA CITING THE UNCERTAINTY. BEYOND THIS HIGH PRESSURE BUILDS IN FOR A NICE TUESDAY AND PEACEFUL WEDNESDAY MORNING. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...HIGH PRESSURE BOTH MOVES OFFSHORE AND WEAKENS CONSIDERABLY. PAIR THIS WITH ZONAL MID FLOW AND THE AFTERNOON SHOULD BE SEASONABLE AND RAIN-FREE WITH A FAIR AMOUNT OF SUNSHINE. THE APPROACH OF A COLD FRONT WILL YIELD A SMALL RISE IN POPS ON THURSDAY OR POSSIBLY EVEN WEDNESDAY NIGHT. THIS SLOW MOVING BOUNDARY MOVES THROUGH ON THURSDAY BUT WILL HAVE TO DEAL WITH MIDLEVEL DOWNSLOPING PREVENTING DEEP MOISTURE. THE FRONT STALLS SOUTH OF THE REGION POSSIBLY CLOSE ENOUGH FOR THE MAINTENANCE OF LOW END POPS. SOME DEEPER MOISTURE AND MORE MEANINGFUL RAIN CHANCES MAY MATERIALIZE OVER THE WEEKEND AS THE FRONT REMAINS TO OUR SOUTH BUT SOME WEAK MID LEVEL IMPULSES WORK TO PROVIDE LIFT ATOP SOME LOW LEVEL ISENTROPIC UPGLIDE. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z. WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE AFTER THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 315 PM SUNDAY...SEAS SLOWLY ON THE RISE IN THE MODERATE ONSHORE WIND FLOW AND 3-5 FOOT SEAS EXPECTED OVERNIGHT. SEVERAL TSTMS ARRIVING FROM THE SW TONIGHT MAY PRODUCE LOCALLY HIGHER WINDS AND SEAS...AND SEVERAL SPECIAL MARINE WARNINGS MAY BE NEEDED FOR TONIGHT WITH CLOUD TO SEA LIGHTNING POSING AN ADDITIONAL HAZARD. WINDS WILL VEER TO S AND SW OVERNIGHT WHICH WILL HELP TO LIMIT WAVE GROWTH AND A SMALL CRAFT ADVISORY IS NOT PLANNED ALTHOUGH AN EXERCISE CAUTION STATEMENT COULD BE NEEDED. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...A SOUTHWEST FLOW OF 10-15 KNOTS INITIALLY WILL INCREASE TO 15-20 BY THE END OF THE DAY MONDAY AS A FRONT MOVES CLOSER FROM THE WEST. THE FRONT FINALLY CROSSES THE WATERS EARLY TUESDAY MORNING WITH A MODEST WESTERLY FLOW OF 10-15 KNOTS IN ITS WAKE. SMOOTH SAILING FOR THE REMAINDER OF THE PERIOD WITH WINDS TEN KNOTS OR LESS FROM THE WEST NORTHWEST AND SEAS OF 2-4 FEET. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 PM SUNDAY...WEDNESDAY BRINGS NEARLY MINIMAL WIND AND SEAS DUE TO HIGH PRESSURE MOVING OVERHEAD. WINDS THOUGH LIGHT WILL VEER CONSIDERABLY AS THE DAY PROGRESSES UNTIL A S TO SW FLOW BECOMES PREDOMINANT LATE IN THE DAY OR AT NIGHT. MORE VEERING IS SLATED FOR THURSDAY AS A COLD FRONT APPROACHES AND VERY SLOWLY CROSSES THE WATERS. WITH THIS FRONT STALLING NEARBY TO OUR SOUTH ON FRIDAY A LIGHT NORTHERLY FLOW WILL BE MAINTAINED. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...MJC SHORT TERM...SHK LONG TERM...MBB AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
201 PM EDT SUN APR 19 2015 .SYNOPSIS... HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE NORTHWEST THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 110 PM SUNDAY...FORECAST PRETTY MUCH ON TRACK WITH A MODERATE TO HEAVY SHOWERS DRIFTING IN FROM THE OCEAN AND THE LEADING EDGE OF THE WIDESPREAD RAIN SHIELD IS MOVING INTO SOUTH CENTRAL NORTH CAROLINA. GENERALLY FOLLOWED THE 3KM HRRR WHICH IS DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO CHANGES THROUGH THE AFTERNOON AS RAIN BECOMES WIDESPREAD AND STEADY. CONVECTIVE DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON CURRENT PARAMETERS AS BEST INSTABILITY OCCURRING MUCH FURTHER SOUTHWEST ACROSS GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO CHANGE TO TEMPERATURE FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST AREAS STILL SEEING 1/2 TO 1 INCH. PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT. GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN LIMITING INSTABILITY. MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/ VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA- BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT. INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES. MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON. TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND TO AFTERNOON HIGHS IN THE MID 70S. WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER 70S THURSDAY AFTERNOON. THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE. FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL CHANCE OF RAIN IN THE AFTERNOON. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... SHORT TERM /THROUGH 18Z MONDAY/... AS OF 140 PM SUNDAY...VFR CONDITIONS WILL PERSIST FOR ANOTHER ONE TO TWO HOURS...BEFORE CONDITIONS BEGIN TO DETERIORATE THIS AFTERNOON. SE WINDS WILL CONTINUE THROUGH THIS EVENING AT 10 TO 15 KNOTS. WIDESPREAD SHOWERS WILL SPREAD FROM THE SW TO NE THIS AFTERNOON WITH A SLIGHT CHANCE OF THUNDERSTORMS THROUGH LATE THIS EVENING. GUIDANCE AND MODEL SOUNDING ARE SHOWING WIDESPREAD IFR CONDITIONS FOR ALL TAF SITES SHORTLY AFTER 00Z. IFR CONDITIONS WILL PERSIST THROUGH THE OVERNIGHT UNDER WIDESPREAD RAIN SHOWERS. CONDITIONS WILL IMPROVE BY 12Z MONDAY AS RAIN SHOWERS TAPERS OFF TO THE EAST. EXPECTING VFR CONDITIONS TO RETURN BY 15Z MONDAY UNDER SCT CLOUDS. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 115 PM SUNDAY...WINDS HAVE DROPPED A BIT FROM THIS MORNING WITH GENERALLY E/NE WIND 10 TO 15 KNOTS WITH SOME GUSTS TO AROUND 21 KNOTS AT DIAMOND SHOALS. SEAS STILL 3 TO 5 FEET WITH LONG PERIOD SWELLS OVER THE CENTRAL AND NORTHERN WATERS. WINDS BECOME SE LATER TODAY AS WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO 20 KNOTS BY THIS EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM FRONT MOVING IN FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25 KT. SEAS BUILDING TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING 6-8 FT LATE TONIGHT. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY. HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO 2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT REMAIN 5-15 KT WITH SEAS 2-4 FEET. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT TUESDAY FOR AMZ150-152-154-156-158. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...DAG AVIATION...DAG/BM MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
148 PM EDT SUN APR 19 2015 .SYNOPSIS... A FRONTAL SYSTEM WILL BRING SHOWERS AND A FEW THUNDERSTORMS THROUGH MONDAY. A FEW STORMS MAY BE STRONG TO SEVERE. DRY AND SEASONABLE HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY AND WEDNESDAY. WARMER TEMPERATURES ARE EXPECTED THURSDAY AHEAD OF THE NEXT COLD FRONT. MUCH COOLER TEMPERATURES ARE POSSIBLE LATE WEEK AND INTO NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1244 PM SUNDAY...NO SIGNIFICANT CHANGES FOR THE EARLY AFTERNOON UPDATE...WITH POP DISTRIBUTION RANGING FROM SCATTERED TO LIKELY ACROSS THE AREA AND A SLIGHT CHANCE OF A THUNDERSTORM. EXTENSIVE CLOUD COVER WILL LIMIT SURFACE BASED BUOYANCY BUT A RAMPING UP IN PRECIPITABLE WATERS AS SEEN IN SATELLITE DATA WILL LIKELY REMOVE ANY CONVECTIVE INHIBITION AND POP-UP SHOWERS COULD OCCUR ANYWHERE NEAR SMALL OUTFLOWS...DIFFERENTIAL HEATING...AND WEAK SEA BREEZE CONVERGENCE ZONES. A BROAD AREA OF PATCHY LIGHT RAIN WILL SPREAD NE ACROSS THE AREA THROUGH THE AFTERNOON. THE PREVIOUS DISCUSSION FOLLOWS. ADJUSTMENTS WERE REQUIRED TO SCALE BACK TIMING AND COVERAGE OF PRECIPITATION TODAY...BASED ON DECLINING NATURE OF SHOWERS ASSOCIATED WITH AN APPROACHING WARM FRONTAL FEATURE. SEVERAL SHOWERS WILL MAKE A RUN TOWARD THE NORTH COAST FROM THE OCEAN...AND AREAS WEST OF I-95 APPEAR POISED TO RECEIVE A TENTH OF AN INCH THROUGH MIDDAY...OTHERWISE PROSPECTS OF SOLID RAIN MEASUREMENTS WERE DECREASED IN THE FORECAST AND THE GRIDDED PRODUCTS THROUGH EARLY AFTERNOON. SOME HOPE REMAINS FOR BREAKS IN THE CLOUD COVER TO OFFER LOW-LEVEL HEATING WHICH COULD INITIATE CONVECTION WITH WEAK SEA BREEZE CONVERGENCE. BETTER RAIN CHANCES APPEAR OVERNIGHT PER SEVERAL OF THE NEAR TERM MODELS. FORECAST FOR TODAY NOW READS SCATTERED EXCEPT FAR WESTERN ZONES LIKELY. DESPITE REDUCTION IN POPS AND TIMING...A FEW TSTMS COULD BECOME STRONG AND SPC MAINTAINS MARGINAL RISK OVER NC AND SLIGHT RISK OVER PORTIONS OF NE SC TODAY. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 AM SUNDAY...INTERESTING START TO THE WORK WEEK AS A SHORTWAVE EMBEDDED WITHIN A DEEPENING TROUGH WILL CREATE THE POTENTIAL FOR STRONG THUNDERSTORMS ON MONDAY. WARM FRONT WILL BE WELL NORTH OF THE AREA MONDAY MORNING...AND MOST OF THE HEAVY RAINFALL ANTICIPATED SUNDAY NIGHT WILL BE NORTH/OFFSHORE BY THE BEGINNING OF THE PERIOD. SOME RESIDUAL SHOWERS MAY PERSIST ON THE COAST EARLY...BUT ACTUALLY EXPECT THE MORNING HOURS TO BE DRY FOR THE MOST PART LOCALLY. THE COLUMN WILL DRY CONSIDERABLY FROM SUNDAY AS THE BEST MOISTURE DEPARTS TO THE NE...AND SOME SUBSIDENCE IS EXPECTED BEHIND AN EXITING SHORTWAVE. THIS WILL LEAVE AT LEAST PARTIAL INSOLATION...AND AS WARM/MOIST ADVECTION CONTINUES THE ATMOSPHERE WILL BECOME QUITE UNSTABLE MONDAY AFTN/EVE. FORECAST MLCAPE VALUES RISE TOWARDS 2000 J/KG...WITH THE SREF MEAN AROUND 1500 J/KG. AT THE SAME TIME...A SHORTWAVE WILL RIDE THROUGH THE DEEPENING TROUGH SO PVA COMBINED WITH HEIGHT FALLS /STEEPENING MID-LEVEL LAPSE RATES/ WILL DRIVE AN ENVIRONMENT CONDUCIVE TO STRONG CONVECTION. ADDITIONALLY...LFQ OF A SUBTROPICAL 250MB JET WILL APPROACH FROM THE SW. HOWEVER...SURFACE FORCING IS MOSTLY WEAK AND THE MID-LEVELS REMAIN QUITE DRY DURING THE MOST UNSTABLE PART OF THE DAY. THIS SUGGESTS THAT ACTIVITY WILL BE ISOLATED OR SCATTERED MONDAY AFTN/EVE...BUT ANY STORM WILL HAVE THE POTENTIAL TO BECOME STRONG AND SPC HAS THE AREA IN A SLIGHT RISK FOR MONDAY. DO NOT EXPECT WIDESPREAD STRONG/SEVERE STORMS...AND ATTM THE BEST FOCUS MAY BE ALONG THE PIEDMONT TROUGH AND WESTERN PORTIONS OF THE CWA. COLD FRONT WILL APPROACH SLOWLY FROM THE NW DRIVEN BY THE DEEPENING UPPER TROUGH...AND IS NOW SLATED FOR A CROSSING JUST BEFORE DAWN TUESDAY. THIS FRONT WILL BE ACCOMPANIED BY MORE WIDESPREAD SHOWER ACTIVITY...BUT NOT EXPECTING STRONG CONVECTION WITH ITS PASSAGE. COLD ADVECTION LAGS THE FRONT CONSIDERABLY...SO WHILE TUESDAY WILL BE DRY WITH MUCH MORE SUNSHINE AS HIGH PRESSURE BUILDS ACROSS THE REGION...TEMPS WILL NOT BE SIGNIFICANTLY COOLER THAN MONDAY. ON THE DISCUSSION OF TEMPERATURES...MONDAY WILL LIKELY BE WELL ABOVE NORMAL WITH WIDESPREAD 80S AWAY FROM THE BEACHES ON STRONG WARM ADVECTION AHEAD OF THE FRONT. A RELATIVELY WARM NIGHT EXPECTED MONDAY NIGHT AS FROPA OCCURS LATE...AND LOWS WILL DROP ONLY INTO THE LOW 60S. SLIGHTLY COOLER TUESDAY WITH HIGHS REACHING WELL INTO THE 70S TO NEAR 80...BEFORE COOL DRY HIGH PRESSURE ALLOWS FOR TEMPS TO CRASH TO AROUND 50 TUESDAY NIGHT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 300 AM SUNDAY...MID-LEVELS EVOLVE INTO A DECIDEDLY WINTER-LIKE APPEARANCE THROUGH THE EXTENDED WITH A LARGE VORTEX CUTOFF ACROSS SOUTHEAST CANADA WHICH WILL SLOWLY DROP ACROSS NEW ENGLAND BY THE WKND. INITIALLY THIS PRODUCES BENIGN AND SEASONABLE WEATHER ACROSS THE CAROLINAS...AS THE FLOW BECOMES ZONAL BENEATH THE CUTOFF...SO SURFACE HIGH PRESSURE WILL BECOME THE DOMINANT FEATURE WED/THU. THIS HIGH WILL MOVE OFFSHORE THURSDAY AHEAD OF THE NEXT COLD FRONT...DRIVEN BY A PIECE OF VORT ENERGY ROTATING AROUND THE LARGE MID-LEVEL VORTEX. MID-LEVEL FLOW REMAINS W/NW HOWEVER...SO ALTHOUGH PRECIP CHANCES INCREASE WITH THE COLD FRONT...SIGNIFICANT SHOWER ACTIVITY IS NOT ANTICIPATED. THE BIGGER STORY COULD BE MUCH COOLER TEMPS BEHIND THIS FRONT FRI/SAT THANKS TO 1000-500MB THICKNESSES DROPPING TOWARDS -2 SD`S FROM CLIMO...AND HIGHS/LOWS BY SATURDAY COULD FALL WELL BELOW NORMAL. A LOW PRESSURE SYSTEM MAY BEGIN TO EMERGE FROM THE GULF COAST STATES AND MOVE TOWARDS THE AREA AT THE END OF THE PERIOD...AND WILL MAINTAIN INHERITED LOW-CHC POP FOR SATURDAY. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... AS OF 18Z...SOME CONVECTION IS TRYING TO MOVE ONSHORE NEAR ILM...OTHERWISE THE COASTAL TERMINALS MAY NOT SEE TOO MUCH ACTION INITIALLY. MAINLY A EAST SOUTHEAST WIND THIS AFTERNOON. THIS EVENING...THE HRRR IS STAYING FAIRLY CONSISTENT IN BRINGING IN AN ORGANIZED LINE OF OF CONVECTION TO THE INLAND TERMINALS AROUND 23Z. WILL LEAN HEAVILY ON THIS MODEL THROUGH THE EVENING HOURS. AFTER THE CONVECTION MOVES THROUGH...EXPECT IFR CEILING THROUGH THE OVERNIGHT HOURS...WITH SOME LIGHT FOG. MONDAY...IMPROVING CEILINGS AS THE DAY WEARS ON WITH A GUSTY SOUTHWEST WIND. CONVECTION IS EXPECTED TO FIRE AFTER THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...A COLD FRONT WILL PUSH THROUGH THE AREA MONDAY NIGHT WITH SHOWERS POSSIBLE FOLLOWED BY MAINLY VFR CONDITIONS TUESDAY AND WEDNESDAY. POSSIBLE SHOWERS THURSDAY AND FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1244 PM SUNDAY...LOW PRESSURE OVER THE MID-MISSISSIPPI VALLEY WILL DEEPEN TODAY. THE INCREASING SOUTHERLY WIND AHEAD OF THIS SYSTEM WILL DRAG A WARM FRONT THROUGH THE COASTAL CAROLINAS THIS AFTERNOON. GENERALLY EASTERLY WINDS THIS MORNING WILL VEER SOUTHEASTERLY THIS AFTERNOON...THEN SOUTHERLY TONIGHT. WINDS WILL INCREASE BUT NOT EXCESSIVELY SO GIVEN THE PRETTY LARGE DISTANCE FROM HERE BACK TO THE LOW...AND ALSO THE FACT THAT THE INCOMING AIRMASS WILL BE SIGNIFICANTLY WARMER THAN THE OCEAN SURFACE LEADING TO MOST OF THE WIND ENERGY RIDING UP AND OVER A COOL AND STABLE LAYER OF AIR AT THE SURFACE. WIDESPREAD SHOWERS AND EMBEDDED T-STORMS SHOULD AFFECT THE COASTAL WATERS THIS AFTERNOON AND TONIGHT. REDUCED VISIBILITY IN HEAVY RAINFALL AND ALSO OCCASIONAL LIGHTNING STRIKES WILL BE THE MOST SIGNIFICANT IMPACTS. SEAS WILL GRADUALLY BUILD DUE TO THE ONSHORE FLOW...WITH THE WORST CONDITIONS EXPECTED NORTH OF CAPE FEAR. THERE IS A 4-6 HOUR WINDOW LATE THIS EVENING INTO EARLY MONDAY MORNING WHERE A SMALL CRAFT ADVISORY MAY BE NEEDED NORTH OF CAPE FEAR DUE TO 6 FOOT SEAS...BUT GIVEN SOME REMAINING UNCERTAINTY ABOUT HOW LONG SOUTHERLY WINDS BLOW BEFORE VEERING SOUTHWESTERLY AND WEAKENING...I WILL DELAY RAISING THE ADVISORY JUST YET. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 AM SUNDAY...COLD FRONT APPROACHING FROM THE WEST WILL PINCH THE GRADIENT MONDAY...AND GUSTY SW WINDS WILL REACH 15-20 KTS WITH SLIGHTLY HIGHER GUSTS. THIS WILL PERSIST ALL OF MONDAY SINCE THE COLD FRONT IS NOT EXPECTED TO CROSS OFFSHORE UNTIL FIRST LIGHT TUESDAY...AND THUS A CHOPPY SEA STATE IS EXPECTED. WAVE HEIGHTS WILL RISE TO 4-5 FT...AND A SCEC MAY BE NEEDED MUCH OF MONDAY. WINDS WILL SHIFT QUICKLY TO THE W AND THEN NW BEHIND THE FRONT TUESDAY MORNING...AND THEN SLOWLY DECREASE IN SPEED FROM 10-15 KTS...TO AROUND 5 KTS AS HIGH PRESSURE BUILDS TOWARDS THE AREA REDUCING THE PRESSURE GRADIENT. SEAS WILL FALL INITIALLY ON THE OFFSHORE WIND TO 2-4 FT...BEFORE DROPPING FURTHER TO 1-2 FT TUESDAY NIGHT. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 300 AM SUNDAY...BROAD HIGH PRESSURE WILL SKIRT ACROSS THE WATERS AND OFFSHORE WEDNESDAY...SO LIGHT AND VARIABLE WINDS WILL GRADUALLY TRANSITION TO A SW DIRECTION WEDNESDAY NIGHT AS RETURN FLOW DEVELOPS. THIS SW FLOW WILL PERSIST MOST OF THURSDAY BUT WITH SPEEDS INCREASING TO 10-15 KTS AHEAD OF A COLD FRONT WHICH WILL CROSS THE WATERS AT THE END OF THE PERIOD. WAVE HEIGHTS OF 1-2 FT WILL BUILD SLOWLY ONCE THE WIND BECOMES PREDOMINANTLY FROM THE SW LATE WEDNESDAY...AND THEN CONTINUE TO SLOWLY RISE THURSDAY TO 3-4 FT BEFORE THE COLD FRONTAL PASSAGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MJC SHORT TERM...JDW LONG TERM...JDW AVIATION...DL MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
117 PM EDT SUN APR 19 2015 .SYNOPSIS... HIGH PRESSURE EXTENDING OVER THE AREA FROM THE NORTH WILL SHIFT OFFSHORE TODAY. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE AREA TONIGHT AS LOW PRESSURE MOVES INTO THE OHIO VALLEY. A COLD FRONT WILL MOVE THROUGH FROM THE WEST EARLY TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY. ANOTHER COLD FRONT WILL MOVE IN FROM THE NORTHWEST THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 110 PM SUNDAY...FORECAST PRETTY MUCH ON TRACK WITH A MODERATE TO HEAVY SHOWERS DRIFTING IN FROM THE OCEAN AND THE LEADING EDGE OF THE WIDESPREAD RAIN SHIELD IS MOVING INTO SOUTH CENTRAL NORTH CAROLINA. GENERALLY FOLLOWED THE 3KM HRRR WHICH IS DOING A GOOD JOB OF DEPICTING THE RAINFALL. NO CHANGES THROUGH THE AFTERNOON AS RAIN BECOMES WIDESPREAD AND STEADY. CONVECTIVE DEVELOPMENT POTENTIAL SEEMS LIMITED BASED ON CURRENT PARAMETERS AS BEST INSTABILITY OCCURRING MUCH FURTHER SOUTHWEST ACROSS GEORGIA...ALABAMA AND THE FLORIDA PANHANDLE. NO CHANGE TO TEMPERATURE FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AS OF 400 AM SUNDAY...LATEST GDNC CONTINUES TO INDICATE WET CONDITIONS TONIGHT AND INCREASED POPS TO 100% ALL ZONES. DIFFLUENT UPR FLOW AHEAD OF UPR TROF LIFTING OUT OF SRN PLAINS WILL INDUCE LARGE SCALE ASCENT ACROSS AREA ALONG WITH DEEP MSTR PLUME FROM GULFMEX. SFC WARM FRONT WILL APPROACH FROM SW AS DEVELOPING LOW PRES MOVES INTO WRN OH VLY. WDSPRD SHOWERS AND PSBLY SCT TSTMS EXPECTED TO GRADUALLY SPREAD SW TO NE ACROSS ERN NC OVERNIGHT. QPF LOWERED SLIGHTLY BASED ON HPC AND LATEST MODEL BLEND...BUT MOST AREAS STILL SEEING 1/2 TO 1 INCH. PER NEAR-TERM...MARGINAL SVR THREAT FOR SW SECTIONS WITH SOME POTENTIAL FOR ROTATING STORMS ALONG AND AHEAD OF WARM FRONT. GENERALLY A HIGH SHEAR/LOW CAPE THREAT WITH WDSPRD CLOUDS AND PCPN LIMITING INSTABILITY. MIN TEMPS MAINLY LOW-MID 60S EVEN WITH WDSPRD RAIN. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 350 AM SUNDAY...BY MONDAY, THE UPPER TROUGH WILL SHIFT EAST NEAR THE GREAT LAKES REGION WITH SEVERAL SHORTWAVES/ VORTICITY MAXIMA ROTATING AROUND THE BASE OF THE UPPER TROUGH. THE SURFACE LOW WILL MOVE NORTHEAST INTO SOUTHEASTERN CANADA WITH THE ATTENDANT COLD FRONT WELL NORTH OF THE REGION. THE BEST LIFT FROM THE NORTHERN STREAM LIFTS WELL NORTH OF THE AREA WHILE THE SOUTHERN STREAM JET REMAINS WELL SOUTHWEST OF EASTERN NC. THE BEST MOISTURE ALSO LIFTS WELL NORTH OF EASTERN NC WITH FORECAST SOUNDINGS INDICATING PWATS FALLING TO 1.20 INCHES MONDAY AFTERNOON. GUIDANCE IS IN GOOD AGREEMENT WITH A SHORTWAVE/VORT MAX MOVING THROUGH EASTERN NC MONDAY AFTERNOON/EVENING WHICH COULD HELP SUPPORT OR ENHANCE ONGOING CONVECTION. 500 MB TEMPS FALL FROM AROUND -11/-12 C SUNDAY TO -15/-16 C MONDAY AFTERNOON INDICATING A FAVORABLE ENVIRONMENT FOR LARGE HAIL SHOULD STORMS BECOME SEVERE. GIVEN SOUTHWESTERLY UNIDIRECTIONAL SHEAR, CAN ALSO EXPECT A FEW SHOWERS/THUNDERSTORMS ALONG THE INLAND MOVING SEA- BREEZE. AS DRY SLOTTING DEVELOPS MONDAY MORNING, CLOUD COVER WILL DIMINISH ALLOWING EXCELLENT INSOLATION. INSTABILITY WILL BE PLENTIFUL THOUGH THE ENVIRONMENT WILL A TRIGGER FOR CONVECTIVE INITIATION, AND LACK VEERING LOW LEVEL WINDS. SPC MAINTAINS A SLIGHT RISK FOR EASTERN NC THROUGH MONDAY EVENING/NIGHT. BIGGEST THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS, THOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT. INCREASED POPS TO CHANCE INLAND MONDAY AFTERNOON. HIGHS MONDAY WILL BE IN THE LOW 80S INLAND AND MID 70S BEACHES. MONDAY NIGHT/TUESDAY...COLD FRONT MOVES OFFSHORE LATE MONDAY NIGHT AND EARLY TUESDAY MORNING WITH SLIGHTLY COOLER AND DRIER AIR MOVING IN. TUESDAY`S HIGHS SHOULD BE IN THE MID 70S...BUT WITH DEWPOINTS DOWN IN THE LOWER 50S BY AFTERNOON. TUESDAY NIGHT/WEDNESDAY...HIGH PRESSURE BUILDS OVERHEAD WITH MAINLY HIGH CLOUDS WEDNESDAY. COOL MORNING LOWS AROUND 50 REBOUND TO AFTERNOON HIGHS IN THE MID 70S. WEDNESDAY NIGHT/THURSDAY...ZONAL FLOW ALOFT CONTINUES AS A COLD FRONT CROSSES THE REGION LATE THURSDAY. GUIDANCE IN MODEST AGREEMENT FOR LIGHT SHOWERS/THUNDERSTORMS THURSDAY, THUS HAVE INTRODUCED SLIGHT CHANCE POP WITH FRONTAL PASSAGE. ANOTHER COOL MORNING THURSDAY WITH LOWS 50 TO 55...REBOUNDING INTO THE UPPER 70S THURSDAY AFTERNOON. THURSDAY NIGHT/FRIDAY...DRY WEATHER BEHIND THE FRONT WITH SUNNY COOLER WEATHER FOR FRIDAY. LOWS AGAIN IN THE 50 TO 55 DEGREE RANGE WITH HIGHS UPPER 60S FAR NORTHEAST AND LOW 70S ELSEWHERE. FRIDAY NIGHT/SATURDAY...ANOTHER SOUTHERN STREAM SYSTEM APPROACHES LATE SATURDAY. HAVE INDICATED INCREASED CLOUD COVER AND A SMALL CHANCE OF RAIN IN THE AFTERNOON. && .AVIATION /17Z SUNDAY THROUGH THURSDAY/... SHORT TERM /THROUGH 12Z MONDAY/... AS OF 700 AM SUNDAY...LIFT STRATUS CIGS DEVELOPED ALL TAF SITES 10-11Z WITH LIFR VSBYS AS WELL AT KPGV AND KISO. CONDITIONS EXPECTED TO LIFT TO VFR BY AROUND 13Z. VFR PERSISTING INTO EARLY AFTN...THEN CONDITIONS DETERIORATING. WIDESPREAD SHOWERS/ISOLD TSTMS EXPECTED TO DEVELOP AND SPREAD SW TO NE ACROSS AREA THIS AFTN INTO EARLY EVENING...WITH WDSPRD IFR CIGS LIKELY ALL TAF SITES BY 00Z AND PERSISTING OVERNIGHT WITH VSBYS 3-5 SM IN SHRA. LIGHT WINDS THIS MORNING WILL BECOME SE 10-15 KT THIS AFTN INTO EVENING. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM SUNDAY...PRECIPITATION DIMINISHES MONDAY BUT SOME ISOLATED STRONG TO SEVERE TSTMS MAY BE POSSIBLE, ESPECIALLY KPGV AND KISO, MONDAY AFTERNOON AND EVENING WHICH COULD PRODUCE SUB-VFR AVIATION CONDITIONS. HIGH PRESSURE BUILDS IN ACROSS EASTERN NC TUESDAY INTO WEDNESDAY YIELDING MOSTLY VFR CONDITIONS. A WEAK FRONT WILL MOVE SOUTH INTO EASTERN NC THURSDAY BUT WITH LIMITED MOISTURE SO EXPECT MOSTLY VFR CONDITIONS THURSDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 115 PM SUNDAY...WINDS HAVE DROPPED A BIT FROM THIS MORNING WITH GENERALLY E/NE WIND 10 TO 15 KNOTS WITH SOME GUSTS TO AROUND 21 KNOTS AT DIAMOND SHOALS. SEAS STILL 3 TO 5 FEET WITH LONG PERIOD SWELLS OVER THE CENTRAL AND NORTHERN WATERS. WINDS BECOME SE LATER TODAY AS WARM FRONT LIFTS NORTH. WINDS INCREASE TO 15 TO 20 KNOTS BY THIS EVENING. PRES GRAD WILL TIGHTEN TONIGHT WITH WARM FRONT MOVING IN FROM SW...RESULTING IN WINDS BECOMING S-SW 20-25 KT. SEAS BUILDING TO 4-6 FT OUTER WATERS LATE TODAY AND PEAKING 6-8 FT LATE TONIGHT. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM SUNDAY...GUSTY S/SW WINDS WILL BUILD SEAS TO 7-8 FEET MONDAY. SEAS WILL REMAIN ELEVATED INTO TUESDAY MORNING AND CURRENT SCA FOR ALL COASTAL WATERS WILL REMAIN IN EFFECT UNTIL 12Z TUESDAY. HIGH PRESSURE WILL BUILD OVER THE NC WATERS TUESDAY INTO WEDNESDAY WITH WINDS SHIFTING MORE WESTERLY, 5-15 KT. SEAS WILL DIMINISH TO 2-4 FT TUESDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT WILL MOVE SOUTH INTO THE NORTHERN WATERS THURSDAY AND SHIFT SOUTH OF THE WATERS THURSDAY NIGHT. WINDS VEER NORTHWEST BEHIND THE FRONT BUT REMAIN 5-15 KT WITH SEAS 2-4 FEET. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM EDT TUESDAY FOR AMZ150-152-154-156-158. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...DAG AVIATION...JBM/DAG MARINE...CTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1203 PM CDT SUN APR 19 2015 .UPDATE... ISSUED AT 1202 PM CDT SUN APR 19 2015 QUICK UPDATE TO ADD A MENTION OF ISOLATED THUNDERSTORMS THIS AFTERNOON WITH SMALL HAIL BEING REPORTED ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA WITH SHALLOW CONVECTION ASSOCIATED WITH COOL TEMPERATURES ALOFT. UPDATE ISSUED AT 929 AM CDT SUN APR 19 2015 THE FORECAST FOR THE REMAINDER OF TODAY IS ON TRACK WITH THE STRATUS FIELD OVERTAKING WESTERN AND CENTRAL NORTH DAKOTA EXPECTED TO SLOWLY SCATTER WITH DIURNAL HEATING WITH RAIN SHOWER COVERAGE INCREASING THROUGH THE AFTERNOON. THIS IS IN LINE WITH THE 12-13 UTC HRRR ITERATIONS. UPDATE ISSUED AT 629 AM CDT SUN APR 19 2015 INITIAL BATCH OF WIDESPREAD RAIN CONTINUES TO PUSH OFF TO THE EAST...THOUGH SECONDARY ROUND OF SCATTERED WRAP AROUND SHOWERS ARE STARTING TO DEVELOP AND WORK INTO FAR NORTHWEST NORTH DAKOTA. HAVE ADJUSTED POPS TO ACCOUNT FOR THIS. HAVE ALSO INCREASED CLOUD COVER MAINLY OVER THE WEST AS CLOUDS CONTINUE TO STREAM IN BEHIND THE LOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT SUN APR 19 2015 CONTINUED CHANCES FOR RAIN AND WINDY CONDITIONS THROUGH SUNDAY...HIGHLIGHT THE SHORT TERM. AN UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS WILL CONTINUE TO PROVIDE AMPLE MOISTURE AND INSTABILITY...PROLONGING CHANCES FOR WIDESPREAD SHOWERS IN CENTRAL AND EASTERN AREAS OF THE STATE THROUGH THE DAY. ADDITIONALLY...TEMPERATURES SLIGHTLY BELOW AVERAGE AND STRONG NORTHWEST WINDS WILL ACCOMPANY THE DEEPENING TROUGH. THE CURRENT 00Z MODEL SUITE PROVIDES GOOD AGREEMENT ON THE UPPER LEVEL TROUGH DIGGING AND SLOWLY MOVING EASTWARD...PUSHING OVER MINNESOTA/EASTERN MANITOBA AND CLOSING OFF BY 12Z MONDAY. NORTH CENTRAL NORTH DAKOTA INTO THE JAMES RIVER VALLEY HAVE THE POTENTIAL FOR A FEW SNOW FLAKES EARLY MONDAY MORNING...AS COLD AIR FILTERING SOUTHWARD FROM CANADA IS EXPECTED TO DROP OVERNIGHT LOWS TO JUST BELOW FREEZING. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 400 AM CDT SUN APR 19 2015 UPPER LOW WILL WORK ALONG THE MINNESOTA/ONTARIO BORDER ON MONDAY. THIS SHOULD KEEP PRECIPITATION TO THE EAST OF OUR AREA THROUGH THE DAY...THOUGH GUSTY NORTHWEST WINDS WILL CONTINUE IN THE WAKE OF THE SYSTEM. A FAST MOVING WAVE WILL MOVE IN BEHIND THE SYSTEM LATE TUESDAY NIGHT INTO EARLY WEDNESDAY WHICH MAY BRING A LITTLE LIGHT PRECIPITATION TO CENTRAL NORTH DAKOTA...BUT WILL KEEP POPS LOW WITH LACK OF MUCH MOISTURE TO WORK WITH. QUIET AND COOL CONDITIONS ARE THEN EXPECTED WITH RIDGING TO THE WEST AND NORTHWESTERLY FLOW OVER OUR AREA. MODELS START TO DISAGREE WITH THE POSITION OF THE RIDGE AND WHETHER A FEW UPPER WAVES WILL MAKE IT THROUGH THE AREA TOWARDS THE END OF THE WEEK. THEREFORE...WILL KEEP ANY PRECIPITATION CHANCES ON THE LOW SIDE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1202 PM CDT SUN APR 19 2015 MVFR/VFR STRATUS THIS MORNING IS EXPECTED TO SLOWLY LIFT AND SCATTER INTO THE AFTERNOON WITH RAIN SHOWER COVERAGE ALSO INCREASING INTO THE AFTERNOON. ISOLATED THUNDERSTORMS WITH SMALL HAIL ARE POSSIBLE. STRONG NORTHWEST WIND GUSTS OF 30-35 KTS ARE ALSO FORECAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA TODAY. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...AC LONG TERM...JJS AVIATION...AYD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1221 PM EDT SUN APR 19 2015 .SYNOPSIS... A WARM FRONT AND UPPER LEVEL DISTURBANCE APPROACHING FROM THE TENNESSEE VALLEY WILL BRING A SOAKING RAIN TO THE REGION TONIGHT AND EARLY MONDAY. ADDITIONAL SHOWERS AND SCATTERED THUNDERSTORMS WILL ACCOMPANY A COLD FRONT AS IT PUSHES EAST ACROSS THE STATE MONDAY AFTERNOON AND EVENING. A LARGE UPPER LEVEL LOW WILL SET UP OVER ONTARIO AND QUEBEC FOR THE MIDDLE AND LATTER PART OF THE WEEK...USHERING IN UNSEASONABLY COOL AIR WHICH WILL LAST INTO THE WEEKEND OR LONGER. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... EARLIER...THICKER CIRROSTRATUS HAS THINNED ACROSS MUCH OF CENTRAL AND NEPA...BUT THIS WINDOW WILL BE FLEETING AS THICKENING MID AND HIGH CLOUDS STREAM IN QUICKLY FROM THE SW DURING THE MID TO LATE AFTERNOON HOURS...WITH THE ONSET OF RAIN 4-6 HOURS AFTERWARD. THE DECENT AMOUNT OF SUNSHINE HAS HELPED TO BOOST TEMPS A FEW-SVRL DEG F ABOVE FCST HOURLY VALUES DURING THE LATE MORNING...BUT NOT MUCH ABOVE ACTUAL FCST HIGHS FOR TODAY. SOME MAX TEMP TWEAKS WERE DONE TO THE GRIDDED FCST DATABASE. OVERALL...A RATHER NICE EARLY SPRING AFTERNOON...WITH A LIGHT TO MODERATE SERLY BREEZE AND HIGH TEMPS RANGING FROM AROUND 60F ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST...TO THE UPPER 60S THROUGHOUT MUCH OF THE SUSQ VALLEY. LATEST MODEL TIMING OF THE LEADING...NE EDGE OF RAIN /INCLUDING THE 12Z NAM...09Z SREF...AND LATEST 14Z HRRR RUN/ SUGGESTS THE BULK OF THE REGION WILL BE DRY FOR MUCH OF THE DAY. FAR SOUTHWESTERN AREAS WILL LIKELY SEE SHOWERS BEGIN AROUND 5 PM /21Z/...WHILE THE ONSET OF RAIN/SHOWERS MOVES TO NEAR A KBFD...TO KUNV AND KMRB LINE AROUND 01Z MONDAY...THEN ACROSS THE SUSQ VALLEY BETWEEN 03Z-05Z MONDAY. && .SHORT TERM /8 PM THIS EVENING THROUGH MONDAY NIGHT/... LITTLE TO NO CHANGE WAS NECESSARY FROM THE PREVIOUS FEW FORECAST CYCLES FOR THIS SHORT TERM PERIOD. THE MAIN CHANGE WAS TO FURTHER REFINE THE TIMING AND TO SHOW A SLIGHTLY MORE-OBVIOUS 4-6HR BREAK BETWEEN THE OVERNIGHT/MORNING RAIN AND THE STORMS IN THE AFTERNOON/EVENING. MINS WILL BE HELD UP AS THE WINDS WILL BE BREEZY. USUALLY...CENTRAL PA DOES NOT GET STRONG WIND GUSTS DURING STABLE SERLY FLOW RAIN EVENTS. SO THOUGHTS OF A WIND ADVY WERE DISCOUNTED RATHER EARLY IN THE FORECAST PROCESS TONIGHT. HOWEVER...THE STRONG LOW AND MID LEVEL FLOW WILL BUMP THE PWATS INTO THE 1-1.5 INCH RANGE TONIGHT AND MONDAY. THUS...RAIN COULD BE HEAVY AT TIMES. WITH THE ADDITIONAL TSRA MON PM...THE QPF REACHES BETWEEN 0.75 AND 1.25 INCHES OVER A LARGE PORTION OF THE AREA. BUT THE STREAM FLOWS ARE REALLY LOW AND NO THUNDER TONIGHT SHOULD TRANSLATE INTO NO FLOOD WORRIES OTHER THAN SOME PONDING OF WATER ON ROADS AND A FEW SMALL CREEKS AT BANKFULL. THINGS ARE GROWING NICELY NOW IN THE SE AND EVEN LOCALLY IN HAPPY VALLEY WHICH SHOULD TAKE UP PLENTY OF WATER COMPARED TO JUST TWO WEEKS AGO. SPC HAS PLACED ALL OF THE AREA INTO MRGL RISK AND BROUGHT THE DAY2 SLGT RISK INTO SRN PA...RIGHTFULLY SO. THE BREAK AND ASSOCIATED BREAKS IN THE CLOUDS/WARM SECTOR ON MONDAY WILL LEAD TO GOOD HEATING AND THE FRONT/FORCING COMES THROUGH AT AN OPPORTUNE TIME TO GRAB THE MAX CAPES AND MIN STABILITY. CAPES MAY BE AROUND 1500J/KG AND LI/S DROP TO -3 TO -5. WIND PROFILES ARE MAINLY MULTI-CELLULAR - BUT WITH THE WARM FRONT LIKELY CUTTING THROUGH THE AREA AT THE TIME...WILL NEED TO KEEP AN EYE OUT FOR ROTATING STORMS - ESPECIALLY IF THEY OCCUR ON OR NEAR LLVL BOUNDARIES. && .LONG TERM /TUESDAY THROUGH SUNDAY/... BEHIND THE COLD FRONT MIDWEEK...THE UPPER LOW HANGS AROUND S CANADA/NEW ENGLAND FOR SEVERAL DAYS KEEPING FAIRLY BRISK W/NW FLOW ACROSS PA. THIS WILL BRING A STEADY STREAM OF COLDER AIR AS TEMPS SLOWLY SLIP A BIT LOWER EACH DAY WITH BELOW NORMAL READINGS FOR A SEVERAL DAY PERIOD LINGERING INTO NEXT WEEKEND. PROXIMITY OF UPPER LOW WILL ALSO KEEP MENTION OF SCT SHOWERS IN THE FORECAST... MAINLY DURING THE DAYTIME HOURS. WEDNESDAY MAY HOLD A FAST-MOVING SHORT-WAVE WHICH COULD PRODUCE WHITE PRECIP - BUT DURING THE MIDDLE OF THE DAY. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS WILL PREVAIL MUCH OF THE DAY...BUT RAPIDLY DETERIORATE FROM SOUTHWEST TO NORTHEAST TONIGHT. EXPECT RESTRICTIONS TO REACH THE FIRST CENTRAL PENNSYLVANIA AIRFIELDS AROUND 00Z MONDAY /KJST/. TIGHTENING GRADIENT LATER TODAY AND TONIGHT AHEAD OF AN APPROACHING COLD FRONT WILL PRODUCE GUSTY WINDS...AND LOW LEVEL WIND SHEAR CONDITIONS. THESE HAVE NOW BEEN ADDED TO ALL TAFS STARTING BETWEEN 00 AND 04Z. RAIN AND WIDESPREAD IFR TO LIFR TONIGHT INTO MONDAY...BEFORE THE PRECIPITATION BECOMES MORE SHOWERY WITH THE APPROACH OF THE FRONT. THIS COLD FRONT WILL ALSO INTRODUCE THE CHANCE OF THUNDERSTORMS MONDAY TO THE ENTIRE REGION. OUTLOOK... MON...WIDESPREAD RESTRICTIONS IN RAIN EARLY...SOME IMPROVEMENT IN THE AFTERNOON...BUT TSRA POSSIBLE. TUE- THU...UNSETTLED WITH NW FLOW EACH DAY...WITH AREAS OF RESTRICTED CIGS/VSBYS IN SHRA IN THE WESTERN AND NORTHERN MOUNTAINS...SPOTTY RESTRICTIONS IN MORE SCATTERED SHRA IN CENTRAL MOUNTAINS...AND MAINLY VFR IN THE EAST AND SOUTHEAST. && .FIRE WEATHER... SFC WIND FROM THE SOUTHEAST WILL BE 10-15 KTS WITH GUSTS AROUND 20KT ACROSS THE HIGHER TERRAIN OF SOUTHERN AND WESTERN PENN THIS AFTERNOON...WHILE THE WIND STAYS A BIT LIGHTER ACROSS THE NE HALF OF THE STATE - WHERE REL HUMIDITY IS EXPECTED TO DIP TO/STAY BELOW 30 PERCENT FOR THE REST OF THE AFTERNOON. GUSTS OF 15 TO 20 MPH ARE POSSIBLE IN THE NORTHEAST BY LATE AFTERNOON. BUT THE GUSTS OVER 20MPH WILL ONLY MATCH UP WITH THE LOW RH/S FOR AN HOUR OR TWO AT THE MOST AND ONLY IN A SMALL PORTION OF THE NORTHERN MOUNTAINS. THEREFORE...PLAN IS AT THIS POINT - NOT TO ISSUE A RED FLAG WARNING. A SIGNIFICANT RAINFALL IS EXPECTED STARTING THIS EVENING AND LASTING UNTIL A COLD FRONT PUSHES THROUGH ON MONDAY AFTERNOON AND EVENING. COOLER TEMPERATURES FOR THE REST OF THE WEEK WILL LIKELY LEAD TO HIGHER RH/S AND KEEP FIRE WEATHER CONDITIONS BELOW CRITICAL. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...DANGELO/LAMBERT LONG TERM...CERU/RXR AVIATION...JUNG FIRE WEATHER...LAMBERT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
200 PM CDT SUN APR 19 2015 .DISCUSSION...SURFACE MAP AT 18Z SHOWS A 1000 MB LOW CENTERED OVER SOUTHERN ILLINOIS, WITH A WARM FROM SITUATED TO OUR NORTH, A COLD FRONT STILL WEST OF THE MISSISSIPPI RIVER, AND A PRE-FRONTAL TROUGH JUST NOW CROSSING THE TENNESSEE RIVER THAT IS PROVIDING THE FOCUS FOR A DEVELOPING LINE OF CONVECTION. SATELLITE IMAGERY IS STARTING TO SHOW SOME BREAKS IN THE CLOUDS, ESPECIALLY WEST OF NASHVILLE. LAPS SOUNDING FOR BNA AT 18Z SHOWS WEAK INSTABILITY, WITH A LIFTED INDEX OF -3.3 AND A CAPE OF 962 J/KG. ATMOSPHERE REMAINS SUFFICIENTLY MOIST, WITH PRECIPITABLE WATER OF 1.44 INCHES AND A K-INDEX OF 34. LATEST HRRR SHOWS SCATTERED CELLS ACROSS MIDDLE TENNESSEE UNTIL A MORE ORGANIZED LINE OF CONVECTION COMES THROUGH WITH THE COLD FRONT BETWEEN 04Z AND 09Z. GIVEN THE TIMING OF THE FRONT, THE POTENTIAL FOR WIDESPREAD SEVERE STORMS APPEARS LOW, ALTHOUGH MIDDLE TENNESSEE DOES REMAIN UNDER A SLIGHT RISK OF SEVERE WEATHER TODAY AND TONIGHT, SO ISOLATED CASES OF SEVERE ACTIVITY ARE STILL POSSIBLE. AFTER A FEW LINGERING SHOWERS ON MONDAY, LOOK FOR A BRIEF RESPITE ON TUESDAY BEFORE THE NEXT COLD FRONT DROPS SOUTHWARD THROUGH MIDDLE TENNESSEE WEDNESDAY AND THURSDAY. GIVEN THAT THE UPPER FLOW ACROSS THE REGION WILL REMAIN EITHER CYCLONIC OR ZONAL, WARM ADVECTION WILL BE HARD TO COME BY, AND SO TEMPERATURES DURING THE NEXT 7 DAYS WILL REMAIN AT OR BELOW NORMAL. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 60 67 43 72 / 50 40 10 10 CLARKSVILLE 57 66 41 71 / 50 40 05 10 CROSSVILLE 58 62 42 63 / 50 60 20 10 COLUMBIA 59 68 43 73 / 60 30 10 10 LAWRENCEBURG 57 67 43 72 / 60 20 10 10 WAVERLY 57 68 42 72 / 60 30 05 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ROSE
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
412 PM EDT SUN APR 19 2015 .SYNOPSIS... LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY. && .NEAR TERM /THROUGH MONDAY/... AS OF 333 PM EDT SUNDAY... FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT. A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z. USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z TONIGHT INTO MONDAY MORNING. NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT. A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER. THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE PIEDMONT. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... AS OF 345 PM EDT SUNDAY... TAIL END OF COLD FRONT AND ASSOCIATED CONVECTION WILL BE EXITING THE AREA JUST AFT 00Z. HOWEVER...A BROAD UPPER TROUGH...ALMOST WINTERLIKE PATTERN CONTINUES TO EVOLVE AND DEEPEN ACROSS THE GREAT LAKES WITH NUMEROUS SPOKES OF PVA/SHORT WAVES REMAINING UPSTREAM. THIS LEAVES THE REGION...ESPECIALLY THE MOUNTAINS...WITH A VERY UNSETTLED PATTERN. AT A MINIMUM...EXPECT VARIABLE CLOUDINESS. TIMING OF EMBEDDED DISTURBANCES WILL BE THE KEY TO THE TIMES FOR THE BETTER CHANCES OF SHOWERS. FOR SEVERAL DAYS...THE GFS HAS INSISTED ON A SIGNIFICANT DISTURBANCE MOVING THROUGH THE REGION WED WITH WIDESPREAD -SHRA AS A RESULT. THE OTHER MODELS REMAIN LACKLUSTER WITH THIS FEATURE...BUT DO SUGGEST AT LEAST SOME SMALL CHANCE WITHIN THIS TIME FRAME. GIVEN THE UNSETTLED NATURE OF THE PATTERN WITH UPSLOPE FLOW AND VERY DIFFICULT TO TIME UPPER DISTURBANCES...CANNOT REALLY DROP POPS AT ANY TIME. BEST FOCUS THROUGH THE PERIOD WILL REMAIN WEST OF THE BLUE RIDGE...AND ESPECIALLY ACROSS THE MOUNTAINS OF WV/FAR SW VA. IN ADDITION...ENOUGH INSTABILITY SUGGESTED WITH COLD AIR ALOFT...TO INTRODUCE ISOLD TSRA WITH THE WED DISTURBANCE AS WELL. 850MB TEMPS DROP TO NEAR 0C ACROSS THE NORTHERN PART OF THE FORECAST AREA BY WED...BUT THE BETTER COLD ADVECTION COMES IN THE EXTENDED PERIOD BEHIND THE WED DISTURBANCE. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 400 PM EDT SUNDAY... BROAD UPPER TROUGH REMAINS IN PLACE AND DOMINATES THE EXTENDED FORECAST...GRADUALLY SHIFTING FURTHER ESE LATE IN THE PERIOD. THIS KEEPS THE REGION IN AN UNSTABLE/UNSETTLED NORTHWEST FLOW WITH NUMEROUS EMBEDDED SHORT WAVES. MODELS VARY CONSIDERABLY AS TO THE TIMING AND PLACEMENT OF THESE DISTURBANCES...BUT ENOUGH AGREEMENT THAT POPS CANNOT BE DROPPED REALLY AT ANY TIME THE OVERALL TREND IS TO PUSH THE BETTER MOISTURE FURTHER SOUTH OF THE REGION AS THE WEEK PROGRESSES AND 850MB TEMPS DROP BELOW 0C IN THE NORTHERN COUNTIES. THE ENTIRE PERIOD SHOULD FEATURE BELOW NORMAL TEMPERATURES WITH LOW CHC POPS...HIGHEST ACROSS THE MOUNTAINS AND TOWARD THE SOUTHERN COUNTIES...WITH THE NORTHERN PIEDMONT THE DRIEST. ALTHOUGH TEMPERATURES WILL BE BELOW NORMAL THROUGHOUT THE PERIOD...NO REAL CLEAR CONCERN AT THIS POINT FOR FROST/FREEZE BECAUSE OF CYCLONIC FLOW AND CLOUDS. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... AS OF 142 PM EDT SUNDAY... KFCX WSR-88D SHOWED RAIN SPREADING NORTHEAST ACROSS THE FORECAST AREA THIS AFTERNOON...AS A WARM FRONT LIFTS NORTH ACROSS THE REGION. CEILINGS WILL LOWER TO MVFR AND IFR WITH RAIN. A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE THIS AFTERNOON AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. SHORTEN THE TIME WINDOW AND KEPT LLWS IN THE KLWB AND KBCB TAFS AFTER 00Z/8PM. CEILINGS WILL LOWER TO IFR THIS EVENING INTO TONIGHT AND WILL REMAIN LOW OVERNIGHT. A COLD FRONT APPROACHES LATER MONDAY WITH SOME THUNDERSTORMS POSSIBLE AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING. MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE TAF PERIOD. EXTENDED AVIATION... VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS. THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY. && .HYDROLOGY... AS OF 330 PM EDT SUNDAY... HAVE EXPANDED THE FLOOD WATCH FOR THE ALLEGHANY HIGHLANDS OF VIRGINIA. A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE ATMOSPHERE OF SOUTHEAST WINDS...WILL BE INCREASING TO AROUND 50 KNOTS LATER THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME. TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH 12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO 2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS. PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER. HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL THROUGH MONDAY MORNING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ018>020-022>024- 033>035. FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012>017-032. NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020. WV...NONE. && $$ SYNOPSIS...AMS/KK NEAR TERM...KK SHORT TERM...RAB LONG TERM...RAB AVIATION...AMS/KK HYDROLOGY...KK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
334 PM EDT SUN APR 19 2015 .SYNOPSIS... LOW PRESSURE OVER WESTERN KENTUCKY WITH A WARM FRONT EXTENDING EAST AND COLD FRONT TRAILING SOUTHWARD FROM THE LOW WILL LIFT NORTHEAST TONIGHT INTO MONDAY. A COLD FRONT CROSSES THE REGION ON MONDAY...THEN HIGH PRESSURE BUILDS IN FOR TUESDAY. && .NEAR TERM /THROUGH MONDAY/... AS OF 333 PM EDT SUNDAY... FLOOD WATCHES REMAIN IN EFFECT INTO TONIGHT. A WARM FRONT TO OUR SOUTH WILL LIFT NORTH THIS EVENING AND CROSS THE FORECAST AREA TONIGHT. DEEPER MOISTURE AND HIGHER PWATS WILL INCREASE IN THE WARM ADVECTION WITH THE NORTHWARD ADVANCE OF THE FRONT. THE REGIONAL RADAR IMAGE SHOWED WIDESPREAD CONVECTION ACROSS THE MID ATLANTIC REGION SOUTHWARD TO THE SOUTHEAST US. THERE ARE SOME CONCERNS OF STRONG CONVECTION ACROSS GEORGIA THIS AFTERNOON MAY TAKE SOME OF THE MOISTURE AWAY FROM OUR AREA. OUR LOCAL RNK WRFARW...HIRESW-ARW...NAM AND GFS WAIT UNTIL AFTER 00Z BEFORE BRINGING IN HEAVIER CONVECTION THIS EVENING...WHILE HRRR AND ECMWF ARE A LITTLE FASTER WITH TIMING. THE HRRR AND HIRESW-ARW LIFTS THE PRECIPITATION NORTHEAST WITH MOST OF RAIN PULLING OUT BY 06-08Z. USED A BLEND OF HRRR AND NAM FOR POPS...TAPERING POPS BACK AFTER 06Z TONIGHT INTO MONDAY MORNING. NOT EXPECTING ANY STRONG THUNDERSTORMS THIS AFTERNOON INTO TONIGHT WITH CLOUD COVER HINDERING INSTABILITIES. HOWEVER...THE LOW LEVEL JET INCREASING TO 50-60 KNOTS FROM THE SOUTHEAST WILL RESULT IN STRONG UPSLOPE AND ISENTROPIC LIFT. THE STRONG WINDS THROUGH A DEEP LAYER WILL PROVIDE LARGE HELICITY VALUES LATE THIS AFTERNOON INTO THIS EVENING. THE DAY ONE CONVECTIVE OUTLOOK (SWODY1) PLACED A MARGINAL (5 PERCENT CHANCE OF WIND) ACROSS SOUTHWEST PORTION OF CWA. PLAYED LOW TEMPERATURES CLOSE TO ADJMAV WITH READINGS FROM THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO AROUND 60 DEGREES IN THE PIEDMONT. A WARM...MOIST AND UNSTABLE AIRMASS EXPECTED MONDAY. THE ATMOSPHERE WILL DESTABILIZE AHEAD OF THE APPROACHING COLD FRONT WITH SHOWERS AND THUNDERSTORMS DEVELOPING MONDAY. INITIALLY CUT BACK POPS CLOSER TO NAM FOR MONDAY MORNING...THEN INCREASED TO LIKELY BY MONDAY AFTERNOON. SPC CONTINUES OUR SLIGHT RISK FOR MONDAY ACROSS MOST OF OUR CWA. THIS IS SUPPORTED BY THE DYNAMIC ENVIRONMENT WITH HEALTHY SHEAR AND DECENT CAPES AROUND 2K. IT WILL ALSO BE QUITE BREEZY WITH EFFICIENT DOWNWARD MOMENTUM TRANSFER IN A WELL MIXED BOUNDARY LAYER. THE FRONT SHOULD BE CLEARING MONDAY NIGHT. HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO THE LOWER 80S IN THE PIEDMONT. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... AS OF 345 AM EDT SUNDAY... COLDER AIR WORKING IN ON NW WINDS BEHIND THE FRONT WILL COMBINE WITH LOW LEVEL MOISTURE TO GENERATE SOME UPSLOPE SHOWERS ACROSS THE FAR WESTERN SLOPES MONDAY NIGHT. A BROAD CLOSED UPPER LOW BUILDING IN OVER THE NORTHEAST US WILL THEN KEEP COOL...BREEZY...AND UNSETTLED WEATHER CONDITIONS ACROSS THE REGION THROUGH MIDWEEK. TUESDAY LOOKS TO BE THE BEST CHANCE FOR A BREAK IN THE ACTION AS ANY LINGERING SHOWERS ACROSS THE FAR WEST DISSIPATE BY EARLY MORNING. BY WEDNESDAY THE NEXT COLD FRONT WILL BE ROTATING IN FROM THE WEST WITH A CHANCE FOR SHOWERS AND MAYBE SOME THUNDER ESPECIALLY WEST OF THE BLUE RIDGE. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE RUNNING AT OR SLIGHTLY BELOW NORMAL WITH UPPER 50S/LOWER 60S WEST OF THE BLUE RIDGE AND MID 60S TO AROUND 70 EAST. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 350 PM EDT SATURDAY... MODELS IN BETTER AGREEMENT TODAY ON A DEEP AND BROAD UPPER LOW CENTERED ACROSS THE EASTERN GREAT LAKES DOMINATING THE WEATHER THROUGH MOST OF THE REMAINDER OF THE WORK WEEK. THIS WILL LEAVE UNSETTLED CONDITIONS ACROSS THE MOUNTAINS...SOMEWHAT LESS SO ACROSS THE PIEDMONT. FOLLOWING THIS DISTURBANCE COMES THE BONAFIDE COLDER AIR WHICH PROMISES TO PUSH 850MB TEMPS DOWN TO 0C OR BELOW FOR MUCH OF THE REMAINDER OF THE WEEK ACROSS THE NORTHERN AREAS. THE UPPER TROUGH GRADUALLY SHIFTS MORE TOWARD THE MID-ATLANTIC LATE IN THE PERIOD...STRENGTHENING THE NORTHWEST FLOW ACROSS THE REGION...AND ALLOWING 850MB TEMPS TO BOTTOM OUT ACROSS THE NORTH AROUND -5C BY SATURDAY. THIS PATTERN WILL CONTINUE TO RESULT IN A SIGNIFICANT TEMPERATURE DIFFERENCE FROM THE WESTERN MOUNTAINS WITH CLOUDS AND VARIABLE CLOUDS/SCATTERED SHOWERS AND MORE SUNNY/DOWNSLOPE NORTHWEST FLOW ACROSS THE PIEDMONT. OVERALL...TEMPERATURES SHOULD AVERAGE BELOW NORMAL THROUGH THE PERIOD...PERHAPS MUCH BELOW IN THE WEST. MEXMOS SHOWS SEVERAL DAYS WITH HIGHS ONLY IN THE 50S/60S WEST AND LOWS IN THE UPPER 30S TO LOWER 40S. WIND AND CLOUDS SHOULD PREVENT ANY FROST/FREEZE CONCERN AT THIS POINT. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... AS OF 142 PM EDT SUNDAY... KFCX WSR-88D SHOWED RAIN SPREADING NORTHEAST ACROSS THE FORECAST AREA THIS AFTERNOON...AS A WARM FRONT LIFTS NORTH ACROSS THE REGION. CEILINGS WILL LOWER TO MVFR AND IFR WITH RAIN. A STRONG SOUTHEAST LOW LEVEL JET WILL CONTINUE TO INCREASE THIS AFTERNOON AND TONIGHT WHICH WILL BRING WIND GUSTS AS HIGH AS 30 KTS. WITH A WEDGE OF HIGH PRESSURE IN PLACE ALONG AND EAST OF THE BLUE RIDGE...AFTER SUNSET THESE STRONG WINDS ARE NOT EXPECTED TO REACH THE SURFACE. SHORTEN THE TIME WINDOW AND KEPT LLWS IN THE KLWB AND KBCB TAFS AFTER 00Z/8PM. CEILINGS WILL LOWER TO IFR THIS EVENING INTO TONIGHT AND WILL REMAIN LOW OVERNIGHT. A COLD FRONT APPROACHES LATER MONDAY WITH SOME THUNDERSTORMS POSSIBLE AHEAD OF AND ALONG THE FRONT...ESPECIALLY EAST OF THE BLUE RIDGE. THIS IS LIKELY TO KEEP PERIODS OF MVFR AND BRIEF IFR IN STORMS UNTIL THE FRONT CLEARS THE REGION MONDAY EVENING. MEDIUM CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING THE TAF PERIOD. EXTENDED AVIATION... VFR RETURNS LATER MONDAY NIGHT AND TUESDAY WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT WITH A DRIER AIRMASS. THEN THE NEXT CHANCE OF MVFR CONDITIONS AND PRECIPITATION WILL BE IN THE MOUNTAINS ON WEDNESDAY AND THURSDAY. && .HYDROLOGY... AS OF 330 PM EDT SUNDAY... HAVE EXPANDED THE FLOOD WATCH FOR THE ALLEGHANY HIGHLANDS OF VIRGINIA. A DEEP LAYER FROM THE SURFACE THROUGH MID LEVELS OF THE ATMOSPHERE OF SOUTHEAST WINDS...WILL BE INCREASING TO AROUND 50 KNOTS LATER THIS AFTERNOON AND EVENING. PRECIPITABLE WATER VALUES JUST ABOVE 1.5 INCHES WILL BE ADVECTED INTO THE FORECAST AREA. THE STRONGEST LIFT AND HIGHEST RAINFALL AMOUNTS WILL BE FROM 18Z/2PM THROUGH 06Z/2AM SO HAVE ADDED HEAVY RAIN TO THE FORECAST ALONG THE BLUE RIDGE FOR THIS TIME FRAME. TOTAL RAINFALL AMOUNTS WILL RANGE FROM 1 TO 3 INCHES THROUGH 12Z/8AM MONDAY. FLASH FLOOD GUIDANCE VALUES WERE ROUGHLY 1.5 TO 2.5 INCHES FOR 3 HOURS. SO THIS AMOUNT OF RAINFALL HAS THE POTENTIAL TO PRODUCE FLOODING ON SMALL STREAMS AND CREEKS. PROBABILISTIC GUIDANCE FOR MAINSTEM RIVERS SUGGESTS A SMALL POSSIBILITY FOR MINOR FLOODING ALONG THE DAN RIVER AND NEW RIVER. HOWEVER...THE IS HIGHLY DEPENDENT ON THE AMOUNT OF RAINFALL THROUGH MONDAY MORNING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...FLOOD WATCH THROUGH LATE TONIGHT FOR VAZ018>020-022>024- 033>035. FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012>017-032. NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020. WV...NONE. && $$ SYNOPSIS...AMS/KK NEAR TERM...KK SHORT TERM...MBS LONG TERM...RAB AVIATION...AMS/KK HYDROLOGY...AMS/KK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1158 AM CDT SUN APR 19 2015 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND MONDAY ISSUED AT 327 AM CDT SUN APR 19 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW OVER CENTRAL NORTH AMERICA EARLY THIS MORNING. IN THE SOUTHERN STREAM...UPPER LEVEL LOW PRESSURE IS SPINNING OVER WESTERN KANSAS/EASTERN COLORADO. AHEAD OF THIS FEATURE...SHOWERS AND THUNDERSTORMS ARE OCCURRING FROM NEBRASKA TO LOUISIANA. EVEN FURTHER NORTHEAST...MID-LEVEL MOISTURE TRANSPORT AND ILL-DEFINED SHORTWAVES ARE ALSO CREATING SHOWERS AND A FEW THUNDERSTORMS FROM WESTERN WISCONSIN INTO ILLINOIS. A COUPLE SPOTTY SHOWERS POPPED UP SHORTLY AFTER MIDNIGHT OVER WOOD COUNTY TO THE DELLS...AND WILL HAVE TO CARRY AN ISOLATED MENTION EARLY THIS MORNING ACROSS THE I-39/ROUTE 51 CORRIDOR. IN THE NORTHERN STREAM...SHORTWAVE ENERGY IS PROGRESSING EAST OVER THE NORTHWEST PLAINS. AS THESE FEATURES MOVE EAST...PRECIP CHANCES AND TIMING ARE THE MAIN FORECAST CONCERNS. TODAY...LOW PRESSURE OVER THE NORTHERN PLAINS WILL HEAD EAST WHILE THE SOUTHERN STREAM LOW WILL LIFT NORTHEAST OVER THE CENTRAL MISSISSIPPI VALLEY. WEAK SHORTWAVE ACTIVITY ROTATING ON THE EASTERN PERIPHERY OF THE UPPER LOW OVER WESTERN KANSAS WILL LIFT NORTH ACROSS THE WESTERN GREAT LAKES TODAY BUT INTO A MORE STABLE AND DRIER AIRMASS. DESPITE THIS...THE HIGHER RES MODELS AND RUC DEPICT SPOTTY SHOWERS DEVELOPING OVER CENTRAL AND NORTHEAST WISCONSIN THIS MORNING WHICH BEAR SOME WEIGHT GIVEN THE SPOTTY SHOWERS POPPING UP OVER THE DELLS AT THIS HOUR. AS A RESULT...QUITE DIFFICULT TO ADD MUCH TEMPORAL RESOLUTION TO THE FORECAST THIS MORNING OTHER THAN SAYING SLIGHT CHANCE OF A SHOWER. FORCING INCREASES OVER WESTERN WISCONSIN DURING THE AFTERNOON WHEN A FGEN BAND MOVES ACROSS THAT PART OF THE STATE. THE EASTERN EDGE OF THE INDUCED RAIN BAND WILL LIKELY BE PUSHING INTO N-C WISCONSIN LATE IN THE AFTERNOON. AM THINKING EASTERN WISCONSIN WILL REMAIN MOSTLY DRY DUE TO NE FLOW. THE SLOWER ARRIVAL OF THE PRECIP WILL HELP TEMPERATURES RISE INTO THE MID 60S OVER CENTRAL WI. CLOUD COVER AND EAST WINDS WILL SUPPORT MUCH COOLER READINGS OVER EASTERN WI THOUGH. TONIGHT...THE MEDIUM RANGE MODELS TRACK THE SOUTHERN STREAM SURFACE LOW FROM CENTRAL ILLINOIS/INDIANA TO NORTHERN LOWER MICHIGAN. SOME POSSIBILITY THAT THE LOW WILL TRACK WEST OF THIS LINE IN THE MESOMODELS THOUGH. COMMA HEAD PRECIP FROM THIS LOW LOOKS TO MOVE INTO NORTHEAST WISCONSIN BY MID TO LATE EVENING. MEANWHILE...RAIN BAND ASSOCIATED WITH MID-LEVEL FGEN AHEAD OF THE NORTHERN STREAM WAVE WILL SHIFT EAST THROUGH THE NIGHT ACROSS CENTRAL AND EASTERN WISCONSIN. SEEMS LIKE A GOOD RECIPE FOR PERIODS OF RAIN ACROSS THE REGION. LOWS RANGING FROM THE UPPER 30S NORTH TO MID 40S SOUTH. MONDAY...THE FGEN RAIN BAND WILL GRADUALLY BE WEAKENING AS IT MOVES EAST ACROSS EASTERN WISCONSIN DURING THE MORNING AND EXITS DURING THE AFTERNOON. THE MID-LEVEL DRY SLOT WILL WORK OVERHEAD IN THE WAKE OF THE RAIN DURING THE AFTERNOON AND MAY SEE A FEW PEAKS OF SUNSHINE. OTHERWISE...BECOMING BREEZY WITH HIGHS IN THE MID 40S NORTH TO LOW 50S SOUTH. .LONG TERM...MONDAY NIGHT THROUGH SATURDAY ISSUED AT 327 AM CDT SUN APR 19 2015 CLOSED UPPER LOW WILL BRING UNSETTLED AND COOL CONDITIONS TO THE REGION TUESDAY INTO WEDNESDAY. THE UPPER LOW WILL GRADUALLY PULL AWAY THURSDAY AND FRIDAY...BUT CYCLONIC FLOW COULD STILL BRING A SMALL CHANCE OF PRECIPITATION THURSDAY INTO FRIDAY ACROSS THE FAR NORTH. DESPITE THE CALENDER STATING ITS LATE APRIL...SOME SNOW IS IN THE FORECAST LATE AT NIGHT INTO THE MORNING HOURS. COULD BE SOME MINOR ACCUMULATION ACROSS THE FAR NORTH TUESDAY MORNING AND AGAIN WEDNESDAY MORNING. BELOW NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEKEND WITH DRY CONDITIONS EXPECTED ON FRIDAY. ONLY MINOR CHANGES MADE TO PRECIPITATION CHANCES AND TEMPERATURES DURING THE PERIOD. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1146 AM CDT SUN APR 19 2015 BROKEN MIDLEVEL CIGS CONTINUE THIS AFTERNOON INTO THE EVENING...THOUGH VFR CONDITIONS SHOULD PREVAIL. LOW PRESSURE THEN MOVE ACROSS THE GREAT LAKES REGION TONIGHT AND WILL RESULT IN AN AREA OF STEADY RAIN OVERNIGHT. PRECIP SHOULD BE SLOWER TO ARRIVE THAN PREVIOUSLY FORECASTED...WITH RAIN ARRIVING LATE EARLY TONIGHT THROUGH MIDNIGHT. LOW END IFR CONDITIONS ARE EXPECTED WITH THIS AREA OF RAIN...WITH LIFR CIGS POSSIBLE AS CURRENT OBS IN AREA OF INCOMING PRECIP IN IL/IN SHOW SCATTERED CIGS BELOW 500FT. LIFR CONDITIONS IN CURRENT RAIN NOT WIDESPREAD ENOUGH AND GUIDANCE WAFFLING ON HOW LOW CIGS WILL GO...SO NOT ENOUGH CONFIDENCE TO ADD IT TO THE TAFS AT THIS TIME...BUT WILL BE SOMETHING TO MONITOR. HEAVIEST RAIN AND WORST CONDITIONS WILL LIKELY BE OVER EASTERN TAF SITES. RAIN WILL TAPER OFF MONDAY MORNING IN NORTH-CENTRAL WISCONSIN WITH MVFR CIGS POSSIBLE BY THE SECOND HALF OF THE MORNING. LIGHT RAIN WILL CONTINUE FURTHER EAST WITH IFR CONDITIONS MOST LIKELY HOLDING TIGHT UNTIL LATER IN THE MORNING. WINDS WILL BACK FROM SOUTHEAST THIS AFTERNOON...TO NORTH OVERNIGHT...TO NORTHEAST MONDAY AS A COLD FRONT SWEEPS THROUGH THE STATE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......ECKBERG AVIATION.......ALLEN