Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/29/14


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
910 AM MST WED AUG 27 2014 .SYNOPSIS... DRIER AIR WILL CONTINUE TO MOVE INTO THE REGION TODAY...USHERING IN A DRIER AND WARMER PATTERN ACROSS THE DESERT SOUTHWEST THROUGH AT LEAST EARLY NEXT WEEK. HIGH TEMPERATURES WILL RETURN TO NEAR NORMAL VALUES BY THURSDAY...PEAKING BETWEEN 105 AND 110 FRIDAY AND SATURDAY...BEFORE RETREATING SLIGHTLY NEXT WEEK. && .DISCUSSION... TAIL END OF A SHORTWAVE TROUGH IS MOVING THROUGH GILA COUNTY THIS MORNING...WITH A FEW LINGERING SHOWERS AND ISOLATED THUNDERSTORMS NOTED ON SATELLITE AND RADAR. WV IMAGERY REVEALS THE PARENT CIRCULATION ACROSS EASTERN UTAH WITH SUBSTANTIAL MID LEVEL DRYING STRETCHING FROM SOUTH-CENTRAL ARIZONA WESTWARD INTO CENTRAL CALIFORNIA. SURFACE DEWPOINTS HAVE BEEN SLOW TO RESPOND AND ARE GENERALLY IN THE LOW TO MID 60S AS OF 16Z. STRONG SUBSIDENCE AND MID LEVEL WARM ADVECTION HAS ALREADY COMMENCED ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA AND WILL CONTINUE TO SPREAD WESTWARD THIS AFTERNOON. THE HRRR ALONG WITH SEVERAL OTHER LOCAL HI-RES MODELS INDICATE A FEW POP-UP SHOWERS ARE POSSIBLE WELL EAST OF PHOENIX THIS AFTERNOON...BUT THE DESERTS WILL REMAIN DRY. THE INHERITED FORECAST INDICATED 10-20 POPS FOR THIS AFTERNOON BUT BASED ON HOW QUICKLY THE SHORTWAVE IS EXITING THE AREA...I MADE SLIGHT REDUCTIONS TO POPS FOR LATER TODAY. ALL IN ALL IT SHOULD BE A QUIET DAY...NO MAJOR UPDATES NECESSARY. && .PREVIOUS DISCUSSION... FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW 500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY AND SATURDAY. THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN GILA COUNTY. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH... GIVEN THE STRONG SUBSIDENCE FORECAST TO MOVE INTO THE AREA TODAY...WEATHER CONCERNS ARE MINIMAL THROUGH THURSDAY. MOSTLY CLEAR SKIES AND LIGHT DIURNAL WINDS ARE FORECAST AT ALL SITES. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... FRIDAY THROUGH TUESDAY... STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...LEINS/KUHLMAN AVIATION...LEINS FIRE WEATHER...CB/MO
AREA FORECAST DISCUSSION
NWS PUEBLO CO
614 PM MDT THU AUG 28 2014 .UPDATE... ISSUED AT 612 PM MDT THU AUG 28 2014 AS UPPER LOW PULLS AWAY TO THE EAST...SHOWERS AND THUNDERSTORMS HAVE BEEN DECREASING EARLIER THAN GRIDS PROTRAYED FOR NORTHERN/WESTERN PORTIONS OF THE FORECAST AREA. GRIDS WERE UPDATED TO REFLECT EARLIER END TO PRECIPITATION. LATEST HRRR SUGGESTS THAT PRECIPITATION SHOULD COME TO AN END FOR MOST AREAS SHORTLY AFTER MIDNIGHT. -KT && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 238 PM MDT THU AUG 28 2014 CURRENTLY... SCATTERED SHOWERS WERE MAINLY OVER THE GREATER PIKES PEAK REGION AND C MTNS...WITH MOST OF THE ACTIVITY ON THE LIGHT SIDE. TEMPS ACROSS THE REGION WERE ON THE COOL SIDE...WITH READING MAINLY IN THE 60S TO LOWER 70S. WAT VAP IMGY SHOWS THE TROUGH ALOFT WAS OVER THE EASTERN PLAINS OF CO AND WAS MOVING SLOWLY EAST. SCATTERED SHOWERS WILL CONTINUE TO MOVE SOUTHEAST ON THE BACKSIDE OF THE UPPER LOW THROUGH THE EARLY EVENING HOURS. AS HEATING DECREASES...PRECIP WILL DECREASE WITH ONLY SOME ISOLD SHOWERS OVER THE FAR E PLAINS BY LATE EVENING. WITH LIMITED CAPE...NOT EXPECTING MUCH IN THE WAY OF STRONG STORM ACTIVITY OR HEAVY RAIN...AND ANY STORMS SHOULD MOVE SOUTHEAST AT A STEADY CLIP. FOR TOMORROW...AS UPPER TROUGH MOVE EAST AND HEIGHTS BEING TO RISE...ALL GUIDANCE SHOWS AREAS DRYING OUT AND TEMPS WARMING UP INTO THE 80S ACROSS THE PLAINS...60S AND 70S VALLEYS AND 40S AND 50S MTNS. SHOWERS WILL MAINLY BE RELEGATED TO THE MTNS TOMORROW AFTERNOON...WITH NEARLY ALL OF THE LOWER ELEVATIONS REMAINING DRY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 238 PM MDT THU AUG 28 2014 ...HOT AND DRY END OF AUGUST AND BEGINNING OF SEPTEMBER... EXTENDED FORECAST NOT LOOKING TOO ACTIVE AT THIS POINT. AFTER THIS CURRENT SYSTEM MOVES TO THE EAST OUR AREA WILL BE UNDER STRENGTHENING W-SW FLOW...WHICH WILL TEND TO KEEP THE PLAINS ON THE WARM SIDE AND MAINLY DRY. THERE WILL BE ENOUGH MID LEVEL MOISTURE FOR SOME ISOLD STORMS OVER THE MTS...BUT NOT MUCH ELSEWHERE. SHOULD GET INTO THE 90S OVER THE PLAINS FOR BOTH SAT AND SUN...WITH POPS NEGLIGIBLE. MT AREAS WILL SEE COMFORTABLE 70S THIS WEEKEND. AS THE JET STAYS MAINLY TO OUR NORTH...A SHORT WAVE TROUGH WILL PASS THROUGH ON SUNDAY...BUT SHOULD HAVE LITTLE IMPACT OTHER THAN A SLIGHT COOLING OFF FOR MONDAY. WE THEN STAY UNDER BROAD CYCLONIC TO ZONAL FLOW AS THE JET REMAINS OVER THE NORTHERN ROCKIES INTO THE HIGH PLAINS. A FEW WEAK DISTURBANCES WILL SET OFF SOME CONVECTION OVER KS AND NE CO...POSSIBLY SNEAKING INTO NE PORTIONS OF OUR CWA...BUT FOR THE MOST PART WE REMAIN ON THE DRY AND WARM SIDE. DOES NOT LOOK LIKE ANY REAL RETURN OF THE MONSOON UNTIL POSSIBLY THE LATTER PART OF NEXT WEEK...AS A DEEPER TROUGH BUILDS OVER THE PACNW AND WE BEGIN TO SEE A RETURN OF SRLY FLOW ALOFT. NEXT WEEKEND LOOKS && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 238 PM MDT THU AUG 28 2014 VFR CONDITIONS WILL PREDOMINATE NEXT 24H AT ALL 3 TAF SITES...KCOS...KALS AND KPUB. A FEW SHOWERS COULD OCCUR THIS AFTERNOON AND EARLY EVENING AT EACH SITE...BUT PRECIP WILL BE BRIEF AS STORMS MOVE OFF TO THE SOUTHEAST. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KT SHORT TERM...HODANISH LONG TERM...ROSE AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
311 PM MDT WED AUG 27 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 240 PM MDT WED AUG 27 2014 ...FEW STRONG STORMS POSSIBLE LATER TODAY AND THIS EVENING...SOME SNOW AT THE HIGHEST PEAKS... CURRENTLY... VERY WELL DEFINED UPPER LOW AS SEEN BY WATER VAPOR IMGY WAS SPINNING OVER NE UTAH. A VORT LOBE FROM THIS SYSTEM WAS OVER WESTERN COLORADO AS A LINE OF TSRA WAS ADVANCING EAST OVER THIS REGION. OVER THE NWS PUB CWA...A DRY SLOT ASSOCIATED WITH THIS UPPER LVL LOW WAS OVER THE WESTERN 1/2 OF THE PLAINS...AS SKIES WERE GENERALLY SUNNY. TEMPS OVER THE PLAINS HAVE WARMED UP INTO THE 80S GENERALLY BELOW 5500 FEET...WITH 60S AND 70S MOST OTHER LOCATIONS. LOOKING AT THE THERMODYNAMIC FIELDS...CAPE VALUES FROM THE SPC WERE IN THE 1000 RANGE WHILE FARTHER EAST VALUES WERE 2500 J/KG. EFFECTIVE DEEP SHEAR WAS 30-35 KNTS. AT THE SFC ACROSS THE REGION...A WEEK COOL FRONT WAS CLEARLY SEEN IN THE VIS SAT PIX IMGY ALONG THE EL PASO/DOUGLAS/ELBERT COUNTY LINE AND IT WAS PROGRESSING SLOWLY SWD. REST OF THIS AFTERNOON AND EVENING... VORT LOBE OVER W CO WILL LIKELY START AFFECTING THE GREATER PIKES PEAK REGION LATE THIS AFTERNOON AND INTO THIS EVENING. HRRR REALLY DOES NOT GET THINGS GOING UNTIL AFTER 9 PM...AND I BELIEVE THIS IS TOO LATE AS THINGS WILL LIKELY GET GOING BY VERY LATE AFTERNOON OR EARLY EVENING. AS MENTIONED ABOVE...SHEAR AND CAPE ARE INCREASING AND I DO EXPECT WE WILL SEE A FEW SUPERCELLS OVER THE EASTERN PLAINS OF COLORADO. SPC RECENTLY ISSUED AN MCD DISCUSSING THIS THREAT. WALDO WILL ALSO NEED TO BE WATCHED. ALTHOUGH STORMS WILL MOVE AT A GOOD CLIP TODAY...ATMOSPHERE HAS PLENTY OF MOISTURE AND ANY HEAVY RAIN OVER A SHORT PERIOD OF TIME WILL CAUSE ISSUES OVER THE BURN SCARS. OVERALL...I BELIEVE BEST CHANCE OF SEVERE WILL GENERALLY BE ALONG AND NORTH OF HIGHWAY 50...ASSOCIATED WITH SOUTHWARD MOVING BOUNDARY...ALTHOUGH STRONG STORMS COULD OCCUR ANYWHERE ACROSS THE REGION GIVEN THE MOISTURE AND DYNAMIC FORCING ASSOCIATED WITH THE UPPER LOW HEADING OUR WAY. TONIGHT... UPPER LOW WILL BE OVER THE STATE. ISOLATED SHOWERS ARE LIKELY TO CONTINUE THROUGHOUT THE NIGHT...BUT AS MENTIONED...BELIEVE THEY WILL BE ISOLATED. BEST CHANCE WILL BE OVER THE CONTDVD REGION. SNOW SHOWERS WILL OCCUR AT HIGHER ELEVATIONS WITH SOME LIGHT ACCUMS LIKELY. TOMORROW... COOL NORTHEAST LLVL FLOW WILL PREVAIL OVER REGION. WITH UPPER LOW OVERHEAD...ANTICIPATE SKIES WILL CLOUD UP RELATIVELY EARLY. ALTHOUGH QUITE A FEW SHOWERS WILL LIKELY DEVELOP TOMORROW...OVERALL HEAVY RAIN THREAT LOOKS LOW AT THIS TIME. IT WILL BE NOTICEABLY COOLER TOMORROW ACROSS THE REGION AS HIGHS WILL ONLY BE IN THE 70S ALONG THE I-25 CORRIDOR WITH TEMPS AOA 80F OVER THE FAR E PLAINS. 60S AND 70S ELSEWHERE ACROSS THE VALLEYS. IT WILL BE COOL ABOVE TREELINE WITH HIGHS ONLY IN THE 30S AND 40S. SNOWSHOWERS WILL BE POSSIBLE. OVERALL BEST CHANCE OF SHOWERS TOMORROW WILL BE ALONG THE EAST FACING SLOPES OF THE EASTERN MTNS. /HODANISH .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 240 PM MDT WED AUG 27 2014 UPPER LOW FINALLY EXITS THE STATE EARLY FRI MORNING...WITH WEAK CONVECTION ENDING FROM WEST TO EAST ACROSS THE REGION THU EVENING. FLAT UPPER RIDGE THEN BUILDS ACROSS THE AREA FRI LEADING TO MOSTLY DRY CONDITIONS AND SEASONABLY MILD TEMPS...ALTHOUGH SOME ISOLATED WEAK TSRA MAY FORM OVER THE MTS IN THE AFTERNOON AS RESIDUAL LOW LEVEL MOISTURE LINGERS. NEW WESTERN U.S. TROUGH BEGINS TO MOVE ONSHORE DURING THE WEEKEND...WITH INCREASING W-SW FLOW ACROSS COLORADO SAT INTO SUN. STILL A VERY SMALL CHANCE OF SOME ISOLATED TSRA OVER THE HIGHER TERRAIN SAT AFTERNOON...THOUGH AGAIN STORMS SHOULD BE HIGH BASED AND WEAK AS MOIST LAYER IS FAIRLY SHALLOW. UPPER TROUGH THEN MOVES INTO THE NORTHERN HIGH PLAINS SUN...PUSHING A COLD FRONT THROUGH COLORADO DURING THE AFTERNOON. WITH NOSE OF THE UPPER JET MOVING ACROSS NORTHERN COLORADO...STRONGEST UPWARD MOTION WILL LIKELY STAY NORTH OF THE AREA...AND ONLY A SLIGHT CHANCE OF TSRA IS EXPECTED OVER THE CENTRAL MTS AND FAR EASTERN PLAINS SUN AFTERNOON/EVENING. TEMPS BOTH SAT AND SUN WILL CLIMB BACK ABOVE NORMAL...WITH WARMEST READINGS JUST AHEAD OF THE COLD FRONT ON SUN. WEAK LOW LEVEL MOISTURE RETURN DEVELOPS BEHIND THE FRONT ON MON...THOUGH AIR MASS STAYS FAIRLY STABLE THROUGH THE DAY UNDER SUBSIDENT UPPER FLOW BEHIND THE DEPARTING TROUGH. AS A RESULT...SUSPECT ANY CONVECTION ON THE PLAINS WILL HAVE TO WAIT FOR DEVELOPING WARM ADVECTIVE LIFT LATE MON NIGHT AS LOW LEVEL JET DEVELOPS. ON TUE/WED...SHALLOW UPSLOPE FLOW WILL CONTINUE OVER THE EASTERN MOUNTAINS AND PLAINS...THOUGH WITH FORCING STAYING RATHER WEAK...SUSPECT CONVECTIVE COVERAGE WILL BE ONLY ISOLATED BOTH DAYS. AFTER SOME MODEST COOLING ON MON...TEMPS BEGIN TO SLOWLY CREEP BACK TO ABOVE SEASONAL LEVELS BY WED...ESPECIALLY OVER THE PLAINS WERE A FEW 90S WILL REAPPEAR. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 240 PM MDT WED AUG 27 2014 MAIN CONCERN IS CONVECTIVE ACTIVITY...ESPECIALLY AT KCOS LATE THIS AFTERNOON AND EVENING. LOCALLY HEAVY RAIN AND POSSIBLY SOME SMALL HAIL WILL BE POSSIBLE. LATER TONIGHT...MODELS HINTING AT SOME LOW CIGS POSSIBLE NEAR DAYBREAK. CIGS WILL LIFT BY MID TO LATE MORNING BUT CLOUDS MAY HANG AROUND A GOOD PART OF TOMORROW WITH PATCHY ON AND OFF SHOWERS. KPUB AND KALS WILL HAVE SOME ISOLD TSRA LATE THIS AFTERNOON AND EVENING...OTHERWISE GENERALLY VFR. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HODANISH LONG TERM...PETERSEN AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1120 PM MDT TUE AUG 26 2014 .UPDATE... ISSUED AT 938 PM MDT TUE AUG 26 2014 SWRN UTAH CONVECTION MOVES INTO SERN UTAH LATER THIS EVENING...BUT WILL BE ENCOUNTERING A MORE STABLE REGIME. SURFACE TEMPS HAVE COOLED SIGNIFICANTLY WITH READINGS IN THE UPPER 50S TO MID 60S. SPC MESOANALYSIS ALSO SHOW OUR AIR MASS HAVE LESS INSTABILITY PER MLCAPE VALUES. STRONG STORMS OVER SWRN UTAH WILL HAVE WEAKENED SIGNIFICANTLY ONCE THIS ACTIVITY REACHES SERN UTAH. THUS THE FLASH FLOOD WATCH WAS CANCELLED EARLIER THIS EVENING. SHOWERS WITH EMBEDDED STORMS HAVE NOT ENDED AS A VORTICITY LOBE ROTATES AROUND THE ANOMALOUS CLOSED LOW ALONG THE NEVADA/UTAH BORDER. THE BAND OF MOISTURE OVER THE FOUR CORNERS GETS LIFTED NORTHWARD AND WRAPS AROUND THE UPPER LOW...EXPANDING IN THE PROCESS. THIS WILL RESULT IN WIDESPREAD SHOWERS ACROSS NE UTAH AND THE NRN 2/3RDS WRN COLORADO. POTENTIAL EXISTS FOR SIGNIFICANT PCPN IN THE UPSLOPE REGION OF THE UINTA MOUNTAINS...THE AREA NORTHWEST OF VERNAL NEEDS TO MONITORED FOR ANY FLOOD POTENTIAL GIVEN NEAR SATURATED GROUND. AREAL FLOOD ADVISORY ALREADY ISSUED FOR ERN DAGGETT COUNTY IN THE JARVIE RANCH AS GRAVEL/DIRT ROADS HAVE BEEN REPORTEDLY WASHED OUT. UPPER LOW WILL BE ABOVE THE WESTERN SLOPE WEDNESDAY AFTERNOON. MAY NEED TO CONSIDER THIS A SPRING COLD CORE SYSTEM WITH HIGHER PRECIPITABLE WATER CONTENT. THE RAIN COOLED AIR MASS WILL HAVE STABILIZE THE AIR MASS...EXPECT AFTERNOON DESTABILIZATION FROM MID LEVEL COLD ADVECTION. WITH LOWER FREEZING LEVELS...SOME THUNDERSTORMS WILL CONTAIN HAIL. ISOLATED LARGE HAIL IS POSSIBLE (ALTHOUGH THE WIND SHEAR PROFILE IS NOT FAVORABLE)...BUT THE MORE LIKELY SCENARIO IS PLENTY OF SMALL HAIL WITH SIGNIFICANT ACCUMULATION. THE COOL WET AUGUST FOR THE NORTHERN AND CENTRAL AREAS OF THE FORECAST AREA CONTINUES FOR ANOTHER DAY. UPDATE ISSUED AT 625 PM MDT TUE AUG 26 2014 ANOMALOUS CLOSED LOW WILL TRACK TOWARD WRN COLORADO TONIGHT AND WILL BE OVERHEAD ON WEDNESDAY AFTERNOON. MOISTURE SURGING NORTHEAST FROM SRN UTAH AND ARIZONA WILL EVENTUALLY WRAP AROUND THE MID LEVEL CIRCULATION WITH PRECIPITATION MORE FOCUSED ACROSS THE NORTH BY WEDNESDAY. APPEARS THAT MUCH OF THE AREA WILL RECEIVE SHOWERS WITH EMBEDDED STORMS ON WEDNESDAY. WILL TAKE ANOTHER LOOK AT THE FORECAST PACKAGE WHEN THE 00Z HRRR ARRIVES WITH POSSIBLE FORECAST UPDATES FOR WEDNESDAY. && .SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT) ISSUED AT 234 PM MDT TUE AUG 26 2014 CONVECTION STARTING TO GET GOING THIS AFTERNOON THANKS TO THE CLOSED LOW OVER UTAH...AVAILABLE MOISTURE...UPPER LEVEL TROUGH ROTATING AROUND LOW AND UPPER LEVEL DYNAMIC SUPPORT. MODEL DIFFERENCES CONTINUE WITH SOME MODELS BEING MORE AGGRESSIVE THAN OTHERS WITH HRRR STILL DOING PRETTY WELL PICKING UP ON MOST CONVECTION ACROSS NM...UT...AZ...AND CO. WHILE SOME SHOWERS AND STORMS ARE MOVING ACROSS THE CWA...THE HRRR SHOWS THE STRONGER CONVECTION ENTERING SERN UT THIS EVENING AND THIS LOOKS TO BE PANNING OUT AS A LINE OF SHOWERS AND STORMS HAS FORMED OVER CENTRAL AND S CENTRAL UTAH AND IS TRACKING EASTWARD. HIGH SPECIFIC HUMIDITIES LENDING THEMSELVES TO SOME HEAVY RAINERS SO THE FLASH FLOOD WATCHES WILL REMAIN IN EFFECT. RAIN WITH SOME EMBEDDED STORMS WILL CONTINUE OVERNIGHT AS THE UPPER LEVEL LOW APPROACHES THE FORECAST AREA. THE STORMS AND SHOWERS OVER THE SAN JUANS WILL SHIFT NORTHWARD AS THE NIGHT PROGRESSES AND BEST UPPER LEVEL SUPPORT ALSO SHIFTS TO THE NORTH...STILL ROTATING AROUND THE LOW PRESSURE. SNOW LEVELS ARE EXPECTED TO DROP NEAR 13K FEET OR SO OVERNIGHT WITH A LIGHT DUSTING OF SNOW POSSIBLE FOR ELEVATIONS ABOVE THAT. FOR TOMORROW...MOST PRECIP WILL BE UP NORTH AS THE LOW PRESSURE STARTS TO FILL AND MOVE OVER UT AND CO. HOWEVER...AS THE LOW MOVES OVER THE CWA DURING THE DAY UPPER LEVEL DYNAMICS WILL AGAIN PLAY A FACTOR WITH MORE PRECIP ON TAP FOR MAINLY THE SAN JUANS NORTHWARD. TEMPERATURES WILL STAY BELOW NORMAL THROUGH THE PERIOD DUE TO PRECIP AND CLOUDINESS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 234 PM MDT TUE AUG 26 2014 THE UPPER TROUGH DROPS ONTO THE EASTERN PLAINS ON THURSDAY WITH THE WESTERN MOST ASSOCIATED SHOWERS CLOSE TO THE CONTINENTAL DIVIDE FAVORING NW-FACING SLOPES. THESE SHOWERS ARE EXPECTED TO END BY THURSDAY EVENING. A FLAT RIDGE TRIES TO BUILD IN FROM THE SOUTHWEST ON FRIDAY. RESIDUAL MOISTURE WILL ALLOW LATE-DAY STORMS TO FIRE MAINLY OVER THE HIGHER COLORADO TERRAIN. THE RIDGE GETS FLATTENED ON SATURDAY AS THE NEXT GULF OF ALASKA TROUGH DIGS INTO THE PACIFIC NW. SATURDAY STILL LOOKS LIKE THE WARMEST DAY OF THE WEEK PERHAPS HITTING 90 DEGREES ONCE AGAIN IN GRAND JUNCTION AND NEAR 100 IN THE SE UTAH LOWLANDS. THE PACIFIC TROUGH WILL PROGRESS THROUGH THE NORTHERN ROCKIES SUNDAY INTO MONDAY. ITS 100KT JET STREAK SWEEPS THROUGH SOUTHERN WYOMING. THIS MAY PRODUCE SCATTERED STORMS ACROSS THE NORTHERN MTNS SUNDAY WITH A FEW STORMS PERSISTING INTO MONDAY. THESE STORMS WILL BE MOVING TO THE EAST AT 45 MPH SO STRONG WINDS ARE A THREAT. ELSEWHERE SUNDAY AND MONDAY WILL HAVE BREEZY AFTERNOON WINDS WITH A SLIGHT COOL DOWN RECOVERING SOMEWHAT ON TUESDAY AS THE TROUGH WORKS ACROSS THE NORTHERN PLAINS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1119 PM MDT TUE AUG 26 2014 NUMEROUS SHOWERS EXPECTED WITH EMBEDDED THUNDERSTORMS THROUGH THE FORECAST PERIOD. THE STRONGEST STORMS WILL PRODUCE 4SM +SHRA/+TSRAGS WITH CIGS LOWERING TO BELOW AIRFIELD MINIMUMS FOR THE MOUNTAIN TAF SITES. CONVECTIVE TURBULENCE SHOULD BE EXPECTED WITH OCCASIONAL MOUNTAIN TOP OBSCURATIONS. SOME IMPROVEMENT IS EXPECTED ACROSS THE FAR SOUTH ON LATE WEDNESDAY AFTERNOON AND EVENING WITH A DECREASING CHANCE FOR -SHRA/-TSRA. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...PF SHORT TERM...TGR LONG TERM...JOE AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
419 PM EDT WED AUG 27 2014 .SYNOPSIS... A COLD FRONT APPROACHING THE REGION WILL TRIGGER A FEW SHOWERS AND THUNDERSTORMS THIS EVENING AND OVERNIGHT. THE FRONT MOVES OFFSHORE EARLY THU MORNING WITH DRIER AND LESS HUMID AIR OVERSPREADING SOUTHERN NEW ENGLAND THU AND FRI...YIELDING MILD DAYS AND COOL NIGHTS. HURRICANE CRISTOBAL WILL PASS WELL OFFSHORE LATE TONIGHT INTO THURSDAY...BUT WILL BRING DANGEROUS SURF AND RIP CURRENTS TO SOUTH FACING OCEAN BEACHES OF RI AND MA. PLEASANT WEATHER LINGERS INTO SAT...THEN A FRONT MAY STALL ACROSS NEW ENGLAND SUN INTO MON BRINGING UNSETTLED CONDITIONS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 4 PM UPDATE... LATEST RUNS OF NAM...12Z ECMWF ALONG WITH HRRR AND RAP13 HAVE BEEN TRENDING TOWARD LESS CONVECTIVE QPF THIS EVENING AND OVERNIGHT. DESPITE MODEST INSTABILITY BEING OBSERVED ON SPC MESOANALYSIS OF 1000-1500 J/KG FROM CENTRAL MA WESTWARD INTO EASTERN NY...THE LACK OF SHEAR AND SURFACE CONVERGENCE IS KEEPING CONVECTION ISOLATED TO WIDELY SCATTERED SO FAR. GIVEN THE ARRIVAL OF THE MID LEVEL TROUGH AND ASSOCIATED DEEP LAYER SHEAR IS AFTER PEAK HEATING /00Z- 06Z/...NOT EXPECTING MUCH IF ANY SEVERE STORMS. HOWEVER CAN/T COMPLETELY RULE OUT AN ISOLATED STRONG STORM OVER WESTERN CT/MA WITH GUSTY WINDS GIVEN INVERTED / SOUNDING SIGNATURE AND BRIEF HEAVY RAIN WITH PWATS UP TO 1.7 INCHES OVER THE LOWER HUDSON VALLEY. CONVECTION WILL WEAKEN AFTER 00Z GIVEN BOUNDARY LAYER COOLING AND WEAK MID LEVEL LAPSE RATES. HOWEVER MODEST SYNOPTIC SCALE FORCING FOR ASCENT AND INCREASING DEEP LAYER SHEAR MAY BE SUFFICIENT FOR A BROKEN LINE OF SHOWERS TO TRAVERSE TO THE COAST LATER THIS EVENING. GIVEN THE LATER TROUGH ARRIVAL COLD FRONTAL PASSAGE NOT EXPECTED TO CLEAR OUR REGION UNTIL OVERNIGHT AND PROBABLY NOT UNTIL SUNRISE FOR THE SOUTH COAST INCLUDING CAPE COD AND THE ISLANDS. THUS ANOTHER WARM NIGHT. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... THURSDAY... POST FRONTAL AIRMASS OVERSPREADS THE REGION AS COLD FRONT DEPARTS THE SOUTH COAST DURING THE EARLY MORNING. MID LEVEL FLOW REMAINS CYCLONIC AS MEAN TROUGH AXIS ALOFT REMAINS OVER NEW ENGLAND. HOWEVER STRONG DRYING THROUGH THE COLUMN WITH NEGATIVE K-INDICES OVERSPREADING THE REGION ALONG WITH DEW PTS TUMBLING INTO THE 50S AND POSSIBLY THE U40S. HOWEVER GIVEN THE COOL TEMPS ALOFT AND CYCLONIC FLOW SHOULD SEE SCT-BKN CU/SCU DURING THE PEAK HEATING HOURS OF THE AFTERNOON. NEVERTHELESS A SPECTULAR DAY WITH LOW HUMIDITY...A REFRESHING NW BREEZE OF 10 TO 20 MPH AND TEMPS NOTICEABLY COOLER WITH HIGHS 75 TO 80. HIGH SURF.... HURRICANE CRISTOBAL PASSES WELL OFFSHORE BUT WNA AND THE HURRICANE VERSION OF THE WNA YIELDS 5-10 FT SWELLS ENTERING THE NEAR SHORE WATERS AND UP TO 12 FT WELL SOUTH OF MVY AND ACK. OUR IN HOUSE SURF CALCULATION SUGGEST BREAKERS OF 6-12 FT AT SOUTH FACING OCEAN BEACHES TOMORROW. THUS VERY DANGEROUS SURF AND RIP CURRENTS. OBVIOUSLY WILL CONTINUE THE HIGH SURFACE ADVISORY WHICH MAY HAVE TO BE EXTENDED INTO FRI AS THE WAVE MODELS TYPICALLY ERODE SWELL ENERGY TOO QUICKLY. SURF AND RIP CURRENTS WILL NOT BE AS DANGEROUS ALONG THE EASTERN MA COAST AS THE SWELL ENERGY WILL BE PARALLEL TO THIS COASTLINE. THU NIGHT... CORE OF COOL AIRMASS MOVES OVER THE REGION WITH 850 MB AND 925 MB TEMPS ABOUT +1 SD COOLER THAN NORMAL. N-NE WINDS WILL PRECLUDE EASTERN MA FROM COOLING OFF TOO /L60S/ MUCH GIVEN OCEAN WIND TRAJECTORY. HOWEVER INTERIOR VALLEYS THAT DECOUPLE COULD SEE MINS IN THE MU40S WITH 50S ELSEWHERE. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... */ HIGHLIGHTS... - SEASONABLE AND DRY WEATHER FOR FRIDAY...ENJOY IT! - HOT AND HUMID CONDITIONS THROUGH THE WEEKEND - THUNDERSTORMS POSSIBLE ACROSS N/W NEW ENGLAND SUNDAY - WET WEATHER ANTICIPATED SUNDAY NIGHT INTO MONDAY NIGHT - COULD REMAIN WARMER THAN AVERAGE INTO NEXT WEEK */ OVERVIEW AND MODEL PREFERENCE... BETTER AGREEMENT AMONG ENSEMBLE MEMBERS WOULD SUGGEST A ZONAL FLOW REGIME WITH SOME WEAK RIDGING AS BOTH THE NAO/PNA REMAIN NEGATIVE TO NEAR-NEUTRAL. EXPECTING AN ABOVE AVERAGE TEMPERATURE PATTERN AS THE ECENS/GEFS/NAEFS/CPC WOULD SUGGEST INTO EARLY SEPTEMBER...ANOMALOUS ON THE ORDER OF +2-3 STANDARD DEVIATIONS. WITH ANTICIPATED WARMER CONDITIONS SUBSEQUENT OF RIDGING...EXPECTING PROLONGED S-FLOW TO ADVECT MUGGY CONDITIONS N. LOOKING TO BE A WARM AND HUMID TIMEFRAME. FOR THE FORECAST PERIOD OVER THE NEXT WEEK BEGINNING FRIDAY...EXPECT THE W-ATLANTIC RIDGE TO BE THE DOMINANT INFLUENCE OVER THE REGIONS WEATHER. FAVOR THE ECMWF WITH THE CONFLUENT FLOW SETUP AND ATTENDANT SURFACE FRONTAL POSITION BETWEEN THE NE-CANADA TROUGH AND W-ATLANTIC RIDGE REMAINING N OF THE REGION PARENT WITH BETTER JET-DYNAMICS AND SHEARED MID-LEVEL ENERGY. ONLY AS A C-CONUS DISTURBANCE INVOKES A WEAK-WAVE LOW ALONG THE FRONT WILL WET-WEATHER SHIFT INTO OUR AREA AROUND MONDAY BASED ON A CONSENSUS OF MODEL DATA. DESPITE MODEL VARIANCE...A BROAD SIGNAL IS DISCERNABLE OF A BRIEF PERIOD OF DRY WEATHER AFTER PASSAGE OF THE WEAK-WAVE LOW...FOLLOWED BY A SHARP COLD FRONT AND PERHAPS THE RETURN OF MORE SEASONABLE CONDITIONS. LOW CONFIDENCE AT THIS TIME AS ENSEMBLE MEANS WOULD SUGGEST THE PROPENSITY FOR ZONAL-FLOW WITH WEAK RIDGING. FAVOR THE DETERMINISTIC ECMWF WITH POSSIBLE OUTCOMES. HIGHLIGHTS/CONFIDENCE ARE BROKEN DOWN IN THE DAILY DISCUSSION BELOW. */ DAY-TO-DAY DETAILS... FRIDAY... HIGH PRESSURE. LIGHT/VARIABLE WINDS. SEA-BREEZES ALONG THE COASTS. SEASONABLE AND MOSTLY CLEAR CONDITIONS...SLIGHTLY COOLER ALONG THE SHORES...WITH HIGHS AROUND THE MID-70S. MID- TO HIGH-LEVEL CLOUDS POSSIBLE AHEAD OF AN ENCROACHING WARM-FRONT FROM THE SW. ALONG WITH WINDS TURNING S OVERNIGHT AS HIGH PRESSURE SHIFTS E...EXPECT MILDER CONDITIONS WITH LOWS AROUND THE MID-50S. SATURDAY... SURFACE WARM FRONT LIFTING NE ACROSS NEW ENGLAND LATE...JOINING WITH A TRAILING COLD FRONT FROM A LOW DISTURBANCE OVER NE-CANADA. AS THE RIDGE SUBSEQUENTLY ENHANCES AHEAD OF THE FRONTAL DISTURBANCE AND A WEAKER DISTURBANCE OVER THE C-CONUS...BELIEVE WET-WEATHER ACTIVITY WILL BE PUSHED WELL N OF THE REGION BY THE INFLUENCE OF THE RIDGE. THUS WILL GO WITH A DRY-WEATHER FORECAST. EXPECT PREVAILING S-FLOW TO BEGIN USHERING WARMER / HUMID CONDITIONS ACROSS THE REGION. WILL SEE HIGHS WARM INTO THE LOW-80S AS A WELL- MIXED BOUNDARY LAYER ALLOWS FOR SCATTERED CUMULUS ALONG WITH THE MIX- DOWN OF BREEZY S/SW FLOW. FEEL THIS WILL RESTRICT SEA-BREEZES...SO EXPECT INTERIOR WINDS TO PUSH THE WARM / HUMID CONDITIONS ALL THE WAY TO THE E-SHORES. MILD AND DRY OVERNIGHT. WITH A LINGERING DRY-SUBSIDENCE INVERSION... HIGHER DEWPOINT AIR ADVECTING N COULD LEND TO LOW CLOUDS / FOG ALONG THE S-SHORE. EXPECTING LOWS AROUND THE LOW- TO MID-60S. SUNDAY... WARM-FRONT WELL-DEFINED TO THE N. PUSH OF H85 +16-18C AIR ACROSS THE REGION. EXPECT S NEW ENGLAND TO BE WITHIN THE WARM-SECTOR OF A HOT AND HUMID AIRMASS. COLLOCATED WITHIN A WELL-MIXED BOUNDARY LAYER... BREEZY S/SW-FLOW DURING THE DAY SHOULD ALLOW FOR INTERIOR WINDS ONCE AGAIN TO RESTRICT SEA-BREEZES AND PUSH FORECAST HIGH TEMPERATURES AROUND THE UPPER-80S TO THE E-SHORES. HEIGHTS FALL AS THE C-CONUS DISTURBANCE SHIFTS E WITHIN THE QUASI- ZONAL FLOW REGIME. SHOWERS / THUNDERSTORMS ARE CERTAINLY PLAUSIBLE N AND W WITHIN MODEST INSTABILITY AND SHEAR...CLOSER TO REGIONS OF FAVORABLE DYNAMICS / ASCENT AS WELL AS THE CONVERGENT NOSE OF HIGHER THETA-E AIR AHEAD OF THE FRONT. LIKELY THE MAJORITY OF ACTIVITY IS ACROSS THE E GREAT LAKES INTO NY/PA...BUT ITS POSSIBLE THAT ACTIVITY DEVELOPS INTO N/W NEW ENGLAND LATE. THIS WOULD POSSIBLY BE THE CASE AS THE CONVECTIVE TEMPERATURE IS MET SUCH THAT ANY INVERSION WOULD ERODE AND BOTH SURFACE-BASED INSTABILITY AND EFFECTIVE SHEAR COULD BE UTILIZED. CAN NOT RULE OUT STRONG STORMS...ESPECIALLY ACROSS S/W FACING SLOPES OF HIGH TERRAIN OVER NW CT / W MA / S NH AS OROGRAPHIC PROCESSES AID IN LIFTING THE WARM / JUICY AIRMASS ALOFT. BUT IT IS POSSIBLE THAT THE RIDGE WINS OUT. STILL A FORECAST WAY OUT IN TIME AND AS WE HAVE SEEN JUST IN THE PAST SEVERAL MODEL RUNS THERE HAS BEEN A FAIR AMOUNT OF VARIABILITY. HAVE MODERATE CONFIDENCE WITH THIS FORECAST TIMEFRAME. RIDGE AND SUBSIDENCE INVERSION LINGERS FOR THE S/E SO WILL KEEP WITH A DRY-FROECAST FOR THOSE AREAS. SUNDAY NIGHT THROUGH MONDAY NIGHT... WEAK-WAVE LOW ALONG THE FRONT THROUGH THE QUASI-ZONAL FLOW PUSHES E AND ACROSS THE REGION. THOUGH APPEARING AS A NOCTURNAL PASSAGE...THE COLLOCATION OF DEEP-LAYER MOISTURE...MINOR INSTABILITY AND SHEAR... AND FORCING ALONG THE FRONTAL BOUNDARY WILL LIKELY YIELD WIDESPREAD SHOWERS WITH THE POSSIBILITY OF HEAVY RAIN AND THUNDERSTORMS. THOUGH IT APPEARS THE BETTER FORCING DYNAMICS SHIFT N/E...SHUNTED BY THE RIDGING PATTERN AND BERMUDA HIGH REMAINING DOMINANT. LOW CONFIDENCE FORECAST AS THE CONSENSUS OF MODEL SOLUTIONS CONTAINS A FAIR AMOUNT OF VARIABILITY. WILL PREVAIL WITH SLIGHTLY ABOVE- AVERAGE CONDITIONS. TUESDAY ONWARD... A LULL IN ACTIVITY IS POSSIBLE BEHIND THE WEAK-WAVE DISTURBANCE. A SHARPER COLD FRONT INTO MIDWEEK FOLLOWED BY HIGH PRESSURE. NOT ALL ENTIRELY CONVINCED ON SUCH OUTCOMES BASED ON ENSEMBLE TRENDS. WOULD ANTICIPATE RIDGING TO REMAIN DOMINANT WITH TEMPERATURES BEING ABOVE- AVERAGE FOR THE TIMEFRAME. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /TODAY THROUGH THURSDAY/...MODERATE CONFIDENCE. THRU 00Z...ANY -TSRA NOT FIRING UNTIL 20Z/21Z WESTERN NEW ENGLAND WITH CHANCES FARTHER EAST FADING TOWARD 00Z. ACTIVITY WILL BE ISOLATED OR WIDELY SCATTERED. VFR PREVAILS WITH LOW RISK OF BRIEF MVFR IN -TSRA. AFTER 00Z...ISOLATED TO WIDELY SCATTERED SHOWERS TIL 06Z THEN MOVING OFFSHORE WITH FRONTAL PASSAGE AND WIND SHIFT FROM SW TO NW 06Z-12Z FROM NW TO SE. VFR PREVAILS WITH BRIEF MVFR POSSIBLE IN ANY HEAVIER SHOWERS. LOW RISK OF BRIEF IFR SOUTH COAST UNTIL FRONTAL PASSAGE 06Z-12Z. THURSDAY...VFR. NORTHWEST WINDS MAY GUST TO 20 KNOTS WITH SCATTERED TO BROKEN SKY COVER AROUND 5000 FEET FROM MIDDAY TO EVENING. THU NIGHT...VFR AND DRY WITH A MODEST NW WIND 10-20 KT DIMINISHING TOWARD MORNING. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. ISOLATED -SHRA/-TSRA 22Z- 04Z POSSIBLE. GIVEN LIMITED AREAL COVERAGE DECIDED NOT TO INCLUDE VCTS AND JUST GO WITH VCSH...THE HIGHER PROBABILITY. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. ISOLATED -SHRA/-TSRA 21Z-03Z. GIVEN LIMITED AREAL COVERAGE DECIDED NOT TO INCLUDE VCTS AND JUST GO WITH VCSH...THE HIGHER PROBABILITY. OUTLOOK...FRI THROUGH MONDAY... FRIDAY...HIGH CONFIDENCE. VFR. LIGHT WINDS. SEA-BREEZES ALONG THE SHORES. SKC. SATURDAY INTO SUNDAY...MODERATE CONFIDENCE. VFR. BREEZY S/SW WINDS. SCT CIGS 4-6 KFT SATURDAY. MVFR-IFR CIGS / VSBYS POSSIBLE ALONG THE S-COAST SATURDAY NIGHT. SHRA/TSRA POSSIBLE FOR N/W NEW ENGLAND LATE SUNDAY. SUNDAY NIGHT INTO MONDAY...LOW CONFIDENCE. MIX OF LOW-END VFR TO MVFR. WIDESPREAD SHRA ACROSS THE TERMINALS. POSSIBLE TSRA. CONTINUED S/SW WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /TONIGHT THROUGH THURSDAY/...HIGH CONFIDENCE. TONIGHT... SOUTH SWELLS FROM CRISTOBAL CONTINUE TO INCREASE. A FEW SHOWERS POSSIBLE THIS EVENING AND OVERNIGHT. SSW WINDS BECOME NW TOWARD SUNRISE AS COLD FRONT APPROACHES FROM THE WEST. THU... SWELLS PEAK AT 5 TO 11 FT TOMORROW ACROSS THE SOUTH COAST WATERS. ADDING TO THE ROUGH SEAS WILL BE A DEVELOPING NW WIND WAVE BEHIND THE FRONTAL PASSAGE. OTHERWISE DRY WEATHER WITH GOOD VSBY. HOWEVER A FEW SHOWERS MAY LINGER EARLY IN THE MORNIGN ACROSS THE SOUTH COASTAL WATERS. THU NIGHT... NW WINDS BECOME N-NE LATE. GOOD VSBY AND DRY WEATHER. OUTLOOK...FRIDAY THROUGH MONDAY... FRIDAY...HIGH CONFIDENCE. HIGH PRESSURE IN CONTROL. LIGHT WINDS. DIMINISHING SEAS WITH ONLY THE S/SE OUTER WATERS EXPERIENCING WAVE HEIGHTS IN EXCESS OF 5-FEET BY MORNING. GOOD BOATING WEATHER. SATURDAY INTO SUNDAY...MODERATE CONFIDENCE. INCREASING S-WINDS. PROLONGED S-FETCH LENDING TO WAVE HEIGHTS IN EXCESS OF 5-FEET ACROSS THE S/SE WATERS. FOG POSSIBLE DURING THE OVERNIGHT HOURS...ESPECIALLY ALONG THE S-COAST. MONDAY...MODERATE CONFIDENCE. CONTINUED S-WINDS. WET-WEATHER MOVING ACROSS THE WATERS. FOG MAY REMAIN AN ISSUE OVER THE WATERS...ESPECIALLY DURING OVERNIGHT PERIODS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 9 PM EDT THIS EVENING FOR CTZ002>004. MA...HIGH SURF ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT THURSDAY FOR MAZ020-022>024. NH...NONE. RI...HIGH SURF ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT THURSDAY FOR RIZ006>008. AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR RIZ001>005. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT FRIDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...NOCERA/SIPPRELL NEAR TERM...NOCERA SHORT TERM...NOCERA LONG TERM...SIPPRELL AVIATION...NOCERA/SIPPRELL MARINE...NOCERA/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
215 PM EDT WED AUG 27 2014 .SYNOPSIS... HIGH PRESSURE OFFSHORE WILL DRAW WARMER AIR ACROSS NEW ENGLAND TODAY WITH HIGHS AROUND 90 FOR MANY LOCATIONS. A COLD FRONT WILL THEN SWEEP THROUGH DURING THE LATE AFTERNOON AND EARLY NIGHT...BRINGING WIDELY SCATTERED SHOWERS AND THUNDERSTORMS. DRY AND COOLER CONDITIONS RETURN THURSDAY AND FRIDAY BEHIND THE FRONT. HURRICANE CRISTOBAL WILL PASS WELL OFFSHORE LATE TONIGHT INTO THURSDAY MORNING...BUT WILL BRING LARGE SURF AND DANGEROUS RIP CURRENTS TO SOUTH FACING OCEAN BEACHES. A FRONT MAY STALL ACROSS NEW ENGLAND...BRINGING UNSETTLED CONDITIONS SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 2 PM UPDATE... TEMPERATURES... FINALLY HIT 90 DEGREES AT LOGAN AT 139 PM THIS AFTERNOON. LAST OCCURRENCE WAS 7/23 WHEN IT WAS 92. NOT MUCH CHANGE FROM PREVIOUS FORECAST OTHER THAN INCREASING HIGHS BY A FEW DEGS. A MODEST SW WIND 10 TO 20 MPH IS HELPING TO TAKE THE EDGE OFF THE HEAT ALONG WITH DEW PTS REMAINING BELOW 70. CONVECTION... 12Z NAM ALONG WITH LATEST HRRR AND RAP13 HAVE REALLY BACKED OFF ON CONVECTIVE QPF AND HAVE DIMINISHED THE EASTWARD TREND...KEEPING THE BULK OF ANY ACTIVITY ACROSS WESTERN NEW ENGLAND LATER THIS AFTERNOON AND EVENING. THIS SEEMS REASONABLE GIVEN MARGINAL INSTABILITY /500-1000J-KG/ ALONG WITH DEEP LAYER SHEAR AND JET DYNAMICS ARRIVING 00Z-06Z...WELL AFTER PEAKING HEATING. THIS MAY BE ABLE TO SUSTAIN SOME SHOWERS INTO THE COASTAL PLAIN THIS EVENING BUT THUNDER NOT LIKELY. WORSE CASE SCENARIO REMAINS AN ISOLATED STRONG T-STORM POSSIBLE WESTERN CT/MA WITH BRIEF GUSTY WINDS AND HEAVY DOWNPOURS. HIGH SURF... FIRST SET OF SWELLS /SWELL FRONT/ APPEAR TO BE ON THE EDGE OF ENTERING SOUTHERN NEW ENGLAND WATERS...WITH BUOY 44097 SOUTHEAST OF BLOCK ISLAND NOW REPORTING 4 FT SWELLS EVERY 12 SECONDS. THIS SHOULD RESULT IN SURF BUILDING RAPIDLY LATER THIS AFTERNOON AND ESPECIALLY TOWARD SUNSET AT SOUTH AND SOUTHEAST FACING OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... TONIGHT... CONSENSUS OF THE MODEL SOLUTIONS BRINGS THE COLD FRONT TO THE COASTAL PLAIN AROUND SUNSET AND OFFSHORE EARLY TONIGHT. EXPECT LINGERING SHOWER/TSTM THROUGH 10 PM IN RI AND EASTERN MASS...AND THROUGH MIDNIGHT CAPE AND ISLANDS. WINDS TURN NORTHWEST BEHIND THE COLD FRONT AND DRAW COOLER DRIER AIR DOWN FROM CANADA. THIS WILL MEAN CLEARING SKIES AND DEW POINTS IN THE 50S AND LOWER 60S. SWELL FROM HURRICANE CRISTOBAL CONTINUES TO INCREASE...WITH 5 FOOT SWELL MOVING INTO OUR SOUTHERN WATERS EARLY TONIGHT. WE HAVE ISSUED A HIGH SURF ADVISORY STARTING TONIGHT. THURSDAY... UPPER SHORTWAVE MOVES ACROSS NEW ENGLAND WITH BRIEF COOLING ALOFT. MOISTURE FIELDS SHOW LINGERING 80 PCT RH VALUES BETWEEN 800 AND 900 MB. THIS SUGGESTS DIURNAL CUMULUS WILL FORM DURING THE DAY. MIXING WILL REACH TO 850 MB WHERE TEMPS OF 10-12C WOULD SUPPORT MAX SFC TEMPS IN THE UPPER 70S AND LOW 80S. WINDS ALOFT WITHIN THE MIXED LAYER ARE FORECAST AT 20 KNOTS...WHICH MAY GET MIXED TO THE SURFACE IN GUSTS. HIGH SURF WILL CONTINUE THROUGH THE DAY AS CRISTOBAL PASSES WELL OFFSHORE. THE HIGH SURFACE ADVISORY WILL CONTINUE THROUGH THE DAY. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * COOL AND DRY WEATHER UNDER HIGH PRESSURE FRIDAY * WARM AND HUMID CONDITIONS INTO THE WEEKEND * SCT SHOWERS/THUNDERSTORMS SUNDAY INTO EARLY NEXT WEEK OVERVIEW AND MODEL PREFERENCES... MEDIUM RANGE MODELS AND THEIR ENSEMBLES ALL CONTINUE TO SIGNAL A LOW AMPLITUDE UPPER LEVEL PATTERN ACROSS THE NORTHERN TIER STATES... WHICH GENERALLY MEANS A FAST MOVING PATTERN IN PLACE. NOTING A DECENT SHORT WAVE DEVELOPING ACROSS THE GREAT LAKES LATE THIS WEEK...THEN PUSHING ALONG IN THE GENERAL W-NW UPPER FLOW TOWARD NEW ENGLAND. A FRONT ALSO TRIES TO SHIFT S...BUT BECOMES PARALLEL TO THIS UPPER FLOW...SO MAY SEE UNSETTLED CONDITIONS MOVE IN FOR SUNDAY AND LABOR DAY. NOTING INCREASING VARIANCE AMONGST THE OP MODEL RUNS EARLY NEXT WEEK IN TRYING TO CLEAR THE SHORT WAVE...WITH POSSIBLY ANOTHER WEAKER ONE MOVING IN. LEANED TOWARD A BLEND OF AVAILABLE MODELS FOR THE EARLY PORTION OF THE FORECAST...WHICH SHOWED GOOD CONTINUITY AND RUN TO RUN CONSISTENCY OVER THE LAST SEVERAL MODEL RUNS...THEN TRENDED TOWARD THE GFS/EC ENSEMBLES BEGINNING SUNDAY THROUGH TUESDAY. DETAILS... THURSDAY NIGHT THROUGH FRIDAY NIGHT... EXPECT DRY AND COOL CONDITIONS AS LARGE HIGH PRES BUILDS OUT OF THE GREAT LAKES...SHIFTING E IN THE BROAD UPPER LEVEL WESTERLY WIND FLOW. WILL MAINLY CLEAR SKIES THU NIGHT AND WINDS BECOMING LIGHT/VRBL MAINLY AFTER MIDNIGHT...TEMPS WILL TUMBLE...WITH READINGS AWAY FROM THE IMMEDIATE COAST AND URBAN CENTERS DROPPING TO THE MID 40S TO AROUND 50. SOME DIURNAL CLOUDS WILL DEVELOP DURING FRIDAY...BUT IT WILL REMAIN COOL WITH HIGHS MAINLY IN THE LOWER-MID 70S. NW WINDS MAY GUST UP TO AROUND 20 KT DURING THE AFTERNOON. CONDITIONS WILL REMAIN DRY FRI NIGHT...BUT THE HIGH WILL CREST ACROSS THE REGION OVERNIGHT. EXPECT SOME MID AND HIGH LEVEL CLOUDS WORKING IN WITH LOWS IN THE 50S. SATURDAY... TRANSITION DAY AS H5 SHORT WAVE MOVES OUT OF THE GREAT LAKES. TEMPS WILL REBOUND AS W-SW WINDS KICK IN...BRINGING IN THE MILDER CONDITIONS WITH INCREASING HUMIDITY ESPECIALLY LATE IN THE DAY INTO SAT NIGHT. A FRONT WILL BEGIN TO SLOWLY SHIFT S OUT OF QUEBEC AND S ONTARIO...SO MAY START TO SEE SOME SHOWERS MOVE INTO WESTERN AREAS SAT NIGHT. CARRIED ONLY LOW CHANCE POPS AT THIS POINT. HIGHS WILL BE IN THE 70S...UP TO AROUND 80 IN THE CT AND MERRIMACK VALLEYS. SUNDAY THROUGH MONDAY... WITH THE HIGH ANCHORED OFF THE MID ATLC AND SE U.S. COAST...ALONG WITH GENERAL W WIND FLOW ALOFT...THE FRONT THAT TRIES TO PUSH S WILL GET HUNG UP IN THIS UPPER FLOW. THE SHORT WAVE WILL MOVE ALONG THE FRONT...SO WILL SEE SCT SHOWERS PUSH ACROSS SUNDAY INTO THE HOLIDAY...WITH BEST SHOT SUNDAY NIGHT AND MON MORNING. DEWPTS ALSO INCREASE. PWATS WILL ALSO INCREASE...ON ORDER OF 1.7 TO 1.8 INCHES /ABOUT +2 SD FOR LATE AUGUST/. SOME MARGINAL INSTABILITY ALSO WORKS IN...SO CAN NOT RULE OUT SOME THUNDERSTORMS. MAY ALSO SEE A FEW PRODUCING LOCALLY HEAVY RAINFALL. TEMPS WILL RISE TO THE UPPER 70S TO MID 80S...MILDEST ON SUNDAY...WITH DEWPTS RISING TO THE MID 60S BOTH DAYS. TUESDAY... SOME QUESTION AS TO TIMING OF EXIT OF PRECIP...AND WHETHER ANOTHER SHORT WAVE DEVELOPS AND PUSHES TOWARD THE REGION. FOR NOW...EXPECT MAINLY DRY BUT WARM CONDITIONS...BUT NOT A LOT OF CONFIDENCE FOR THIS PORTION OF THE FORECAST. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /TODAY THROUGH THURSDAY/...MODERATE CONFIDENCE. THRU 00Z...ANY -TSRA NOT FIRING UNTIL 20Z/21Z WESTERN NEW ENGLAND WITH CHANCES FARTHER EAST FADING TOWARD 00Z. ACTIVITY WILL BE ISOLATED OR WIDELY SCATTERED. VFR PREVAILS WITH LOW RISK OF BRIEF MVFR IN -TSRA. AFTER 00Z...ISOLATED TO WIDELY SCATTERED SHOWERS TIL 06Z THEN MOVING OFFSHORE WITH FRONTAL PASSAGE AND WIND SHIFT FROM SW TO NW 06Z-12Z FROM NW TO SE. VFR PREVAILS WITH BRIEF MVFR POSSIBLE IN ANY HEAVIER SHOWERS. LOW RISK OF BRIEF IFR SOUTH COAST UNTIL FRONTAL PASSAGE 06Z-12Z. THURSDAY...VFR. NORTHWEST WINDS MAY GUST TO 20 KNOTS WITH SCATTERED TO BROKEN SKY COVER AROUND 5000 FEET FROM MIDDAY TO EVENING. THU NIGHT...VFR AND DRY WITH A MODEST NW WIND 10-20 KT DIMINISHING TOWARD MORNING. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. ISOLATED -SHRA/-TSRA 22Z- 04Z POSSIBLE. GIVEN LIMITED AREAL COVERAGE DECIDED NOT TO INCLUDE VCTS AND JUST GO WITH VCSH...THE HIGHER PROBABILITY. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. ISOLATED -SHRA/-TSRA 21Z-03Z. GIVEN LIMITED AREAL COVERAGE DECIDED NOT TO INCLUDE VCTS AND JUST GO WITH VCSH...THE HIGHER PROBABILITY. OUTLOOK...FRI THROUGH SUNDAY... FRIDAY...HIGH CONFIDENCE. VFR WITH SKC THURSDAY NIGHT INTO FRIDAY. LIGHT WINDS. PATCHY FOG AFTER 06Z FRI WITH LOCAL MVFR TO IFR CONDITIONS POSSIBLE IN NORMALLY PRONE AREAS. SEA BREEZES FRIDAY. SATURDAY INTO SUNDAY...MODERATE CONFIDENCE. VFR. INCREASING S-SW WINDS. BETTER CHANCES FOR SHRA/TSRA SUNDAY ACROSS THE INTERIOR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /TODAY THROUGH THURSDAY/...HIGH CONFIDENCE. 2 PM UPDATE... 3-5 FT SOUTHERLY SWELLS WITH A PERIOD OF 12 SECONDS AT BUOY 44097 SOUTHEAST OF BLOCK ISLAND. THUS SWELLS FROM CRISTOBAL HAVE ENTERED SOUTHERN NEW ENGLAND WATERS. EARLIER DISCUSSION BELOW. ============================================================ TODAY...HIGH PRESSURE OVER THE WATERS WILL SHIFT FARTHER OFFSHORE. EXPECT LIGHT WINDS/PATCHY FOG FIRST THING THIS MORNING...OTHERWISE GOOD VSBY WITH SOUTHWEST WINDS 10-15 KNOTS. AN APPROACHING COLD FRONT MAY BRING SCATTERED SHOWERS/TSTMS TOWARD EVENING. TONIGHT...INCREASING SOUTH SWELL FROM HURRICANE CRISTOBAL. THE SOUTHERN WATERS WILL EXPERIENCE A 5 FOOT SWELL IN THE EARLY NIGHT AND 6 TO 8 FOOT SWELL BY MORNING. THURSDAY...SOUTH SWELL CONTINUES THROUGH THE DAY WITH 6 TO 9 FOOT SEAS...MAINLY SWELL...ON THE SOUTHERN WATERS. NORTHWEST WIND WILL BE GUSTY NEAR SHORE WITH MAXIMUM GUSTS AROUND 20 KNOTS. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... THURSDAY NIGHT...HIGH CONFIDENCE. EXPECT S SWELL FROM HURRICANE CRISTOBAL TO CONTINUE THROUGH THE NIGHT...THOUGH MAY START TO SUBSIDE LATE. SEAS UP TO 7-9 FT ON THE OUTER WATERS. N-NW WIND GUSTS UP TO 20 KT ON THE EASTERN OUTER WATERS. FRIDAY...HIGH CONFIDENCE. N WINDS GUSTING TO 20 KT EARLY...THEN WILL VEER TO E-NE AND DIMINISH DURING THE DAY. SEAS MAY LINGER AT AROUND 5 FT ON THE OUTER WATERS DURING THE DAY BEFORE SUBSIDING. SATURDAY AND SUNDAY...MODERATE CONFIDENCE. WINDS BECOME S-SW DURING SAT AND CONTINUE THROUGH SUN. GUSTS SHOULD REMAIN BELOW SMALL CRAFT CRITERIA...BUT SEAS MAY BUILD UP TO AROUND 5 FT ON THE SOUTHERN OUTER WATERS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 9 PM EDT THIS EVENING FOR CTZ002>004. MA...HIGH SURF ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT THURSDAY FOR MAZ020-022>024. NH...NONE. RI...HIGH SURF ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT THURSDAY FOR RIZ006>008. AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR RIZ001>005. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 5 PM THIS AFTERNOON TO 8 PM EDT THURSDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...WTB/EVT NEAR TERM...NOCERA SHORT TERM...WTB LONG TERM...EVT AVIATION...NOCERA/EVT MARINE...WTB/EVT
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
958 AM EDT WED AUG 27 2014 .DISCUSSION... MORNING SOUNDINGS FROM KXMR AND KTBW CONTINUE TO SHOW A VERY DRY AND STABLE AIRMASS ACROSS CENTRAL FLORIDA TODAY. LINGERING MOISTURE AND 10-15 KT NORTH-NORTHEAST FLOW IN THE LOWER LEVELS IS STILL BEING ABLE TO SQUEEZE OUT A FEW SHOWERS OVER THE COASTAL WATERS WHICH ARE BEING STEERED ONSHORE THIS MORNING. HRRR MODEL SHOWS ADDITIONAL ISOLATED SHOWERS POSSIBLE ALONG THE INLAND MOVING EAST COAST SEA BREEZE THIS AFTERNOON. SO WILL KEEP A SLIGHT CHANCE FOR SHOWERS MENTIONED IN THE FORECAST FOR TODAY. HOWEVER MOST AREAS LOOK TO REMAIN DRY. HIGHS WILL RANGE FROM THE UPPER 80S/AROUND 90 DEGREES ALONG THE COAST UP TO THE LOW/MID 90S INLAND WITH PARTLY SUNNY SKIES FORECAST. && .AVIATION...VFR CONDS GENERALLY EXPECTED. A FEW ONSHORE MOVING SHOWERS WILL OCCUR ALONG THE COAST THIS MORNING AND ADDITIONAL ISOLATED SHOWERS POSSIBLE INLAND ALONG THE EAST COAST SEA BREEZE THIS AFTERNOON. && .MARINE...WEAKENING PRESSURE GRADIENT WILL ALLOW N/NE WINDS TO DECREASE INTO TONIGHT. HOWEVER WIND SPEEDS UP TO AROUND 15 KNOTS STILL POSSIBLE OFFSHORE THROUGH THIS AFTERNOON WITH LINGERING SWELLS CONTRIBUTING TO SEAS UP TO 6-8 FEET. WILL MAINTAIN SMALL CRAFT ADVISORY FOR SEAS OFFSHORE WITH SMALL CRAFT EXERCISE CAUTION NEARSHORE. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM EDT THURSDAY FOR WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE. && $$ WEITLICH/JOHNSON
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
340 AM EDT WED AUG 27 2014 .SYNOPSIS... 07Z WATER VAPOR AND H4 RAP ANALYSIS SHOW THE MAIN NORTHERN STREAM FLOW ALIGNED WELL TO THE NORTH NEAR THE CONUS/CANADIAN BORDER. SOUTH OF THIS MAIN FLOW...TWO FEATURES DOMINATE THE CONUS WEATHER INCLUDING A POTENT TROUGH/UPPER LOW PROGRESSING EASTWARD OVER THE INTERMOUNTAIN WEST...AND A LONGWAVE RIDGE COVERING MUCH OF THE DEEP SOUTH TO THE EASTERN SEABOARD. THIS RIDGE HAS EXPANDED SOUTHWARD OVER THE PAST 24 HOURS AND IS NOW FIRMLY IN CONTROL OVER THE FL PENINSULA. HURRICANE CRISTOBAL STICKS OUT ON THE UPPER AIR CHARTS AS WELL OFF THE SE CONUS COASTLINE EARLY THIS MORNING...HOWEVER CRISTOBAL IS NOW PULLING AWAY FROM OUR REGION AND WILL ONLY INCREASE ITS DISTANCE THROUGH THE DAY. AS WAS TALKED ABOUT MONDAY NIGHT...A VERY ANOMALOUS AIRMASS HAS ARRIVED OVERHEAD WITHIN DEEP LAYER NORTH/NE FLOW. THE 27/00Z KTBW SOUNDING PROFILE SHOWS ALL THE ANTICIPATED FEATURES. THE COLUMN PW IS NOT RECORD SETTING...BUT IS EXTREMELY DRY FOR AUGUST...AND OUR MID-LEVEL TEMPS ARE NEAR OR AT ALL TIME HIGHS FOR AUGUST. THE MEASURED PW VALUE OFF THE KTBW SOUNDING WAS AROUND 1.25"...WHICH IS MORE THAN 2 STANDARD DEVIATIONS BELOW CLIMATOLOGY FOR LATE AUGUST. THE 500MB TEMP WAS BETWEEN -1C AND -2C WHICH IS GREATER THAN THE 99% PERCENTILE OF VALUES FOR AUGUST. THIS VERY DRY COLUMN AND EXTREMELY POOR LAPSE RATES BELOW 500MB CONTRIBUTED HIGHLY THE LACK OF DEEP CONVECTION ON TUESDAY. THE ONLY REAL MOISTURE IN THE COLUMN IS IN THE LOWER LEVELS ASSOCIATED WITH ATLANTIC MOISTURE ARRIVING ON STEADY NORTHEAST WINDS. SEEING A FEW ISOLATED AND VERY SHALLOW SPEED CONVERGENCE SPRINKLES MAKING THERE WAY ACROSS THE PENINSULA FROM THE EAST COAST EARLY THIS MORNING...HOWEVER DO NOT EXPECT ANY MEASURABLE PRECIP FROM ANY OF THESE. IN FACT...AS CRISTOBAL CONTINUES TO MOVE AWAY AND HIGH PRESSURE DIGS SOUTHWARD INTO THE SOUTHEAST CONUS...THE GRADIENT WILL BE WEAKENING WITH TIME TODAY...MAKING CONDITIONS LESS EFFICIENT FOR THE SPEED CONVERGENCE SHOWERS PRODUCTION. && .SHORT TERM (TODAY THROUGH THURSDAY)... TODAY... WE ARE ONLY GOING TO SEE SLIGHT COOLING ALOFT TODAY...AND ONLY SLIGHT MOISTENING THROUGH THE COLUMN. THEREFORE...DEEP CONVECTIVE IS STILL GOING TO ONCE AGAIN HAVE A VERY DIFFICULT TIME . IF ANY ISOLATED STORMS WILL BE ABLE TO GROW LATE IN THE AFTERNOON OR EVENING...IT SHOULD BE WELL SOUTH OF THE I-4 CORRIDOR WHERE THE "GREATEST" MODERATION OF THE AIRMASS WILL HAVE OCCURRED BY 21-00Z. GREATEST IS IN QUOTES BECAUSE EVEN OVER OUR SOUTHERN ZONES THE MODERATION IS MINOR. YESTERDAY WE WERE DISCUSSING HOW THE NAM WAS AGGRESSIVE IN PIVOTING A SURFACE TROUGH NORTHWARD OUT OF THE SOUTHEAST GULF OF MEXICO AND RETURNING DECENT MOISTURE TO OUR SOUTHERN ZONES BY LATE TODAY. WELL...THE NAM IS STILL THE MOST AGGRESSIVE BUT HAS BACKED OFF CONSIDERABLY FROM ITS SOLUTION FROM 24 HOURS AGO. IT APPEARS AS THOUGH THE GFS/ECMWF SOLUTIONS FROM YESTERDAY WILL BE CLOSER TO REALITY WITH THE TRUE TRANSITION DAY TOWARD A COLUMN MORE FAVORABLE TO DEEP CONVECTION BEING THURSDAY. USING THE ABOVE PHILOSOPHY...THE SENSIBLE WEATHER FORECAST FOR TODAY WILL FEATURE MAINLY DRY CONDITIONS WITH TEMPERATURES IN THE LOWER TO MIDDLE 90S. THERE WILL BE A SLIGHT CHANCE OF A VERY LATE DAY SHOWER OR ISOLATED STORM TO THE SOUTH OF I-4...BUT COVERAGE SHOULD BE VERY LIMITED (IF THEY OCCUR). MOST OF THE HIRES CONVECTION ALLOWING GUIDANCE MEMBERS ONLY SHOW ISOLATED AND BRIEF DURATION CELLS...AND HAVE FOUND THAT MANY OF THESE MODELS AND THERE MICROPHYSICS SCHEMES ARE OFTEN BIASED TOWARD THE AGGRESSIVE SIDE WHEN IT COMES TO DEEP CONVECTION. THE GRADIENT WILL BE WEAKENING TODAY...SO THE BREEZY CONDITIONS FROM THE EAST SEEN THE PAST TWO DAYS WILL NOT BE AS PRONOUNCED. GRADIENT SHOULD RELAX ENOUGH BY THE SECOND HALF OF THE AFTERNOON TO SUPPORT SEA-BREEZE DEVELOPMENT...SO EXPECT WINDS TO EVENTUALLY SHIFT ONSHORE NEAR THE BEACHES. TONIGHT... ENSEMBLE NWP SUITE SHOW THE WEST TO EAST ELONGATED SURFACE TROUGH WILL BEGIN TO PIVOT NORTHWARD INTO THE SOUTHERN HALF OF THE PENINSULA DURING THE OVERNIGHT. THIS TROUGH AXIS REPRESENTS THE LEADING EDGE OF THE DEEPER MOISTURE RETURN WHICH LOOKS TO BE REACHING OUR FAR SOUTHERN ZONES DOWN TOWARD FORT MYERS EARLY THURSDAY MORNING. THIS TROUGH IS DEFINED ENOUGH THAT THERE IS A DECENT SWATH OF SURFACE FOCUS/CONVERGENCE PIVOTING NORTHWARD WITH IT. GENERALLY SPEAKING...DO NOT ANTICIPATE MUCH SHOWER ACTIVITY DURING THE OVERNIGHT OVER OUR SOUTHERN LAND ZONES DUE TO THE MINIMUM OF INSTABILITY AND RESIDUAL DRY AIR ALOFT. HOWEVER...ANTICIPATE BETTER CHANCES FOR SHOWERS DURING THE SECOND HALF OF THE NIGHT OVER THE SOUTHERN COASTAL WATERS WHERE LOW LEVEL INSTABILITY IS MAXIMIZED. STILL WILL BE DEALING WITH THE DRIER AIR ALOFT TO LIMIT THE GROWTH POTENTIAL...BUT WILL INCLUDE CHANCE POPS FOR SHOWERS/ISO STORMS OVER THE COASTAL WATERS AFTER 06Z TO THE SOUTH OF TAMPA BAY. THURSDAY... THURSDAY BEGINS THE TRUE TRANSITION BACK TO A MORE TYPICAL LATE SUMMER PATTERN FOR THE END OF THE WEEK. LOOKING AT PRETTY GOOD AGREEMENT BETWEEN THE NWP MEMBERS REGARDING THE TIMING OF A RATHER SHARP MOISTURE GRADIENT IN THE LOWER/MIDDLE LEVELS MOVING NORTHWARD THROUGH THE DAY. APPEARS THIS GRADIENT WILL REACH NORTHWARD TO AROUND THE I-4 CORRIDOR BY EARLY EVENING. THEREFORE THE BEST ENVIRONMENT FOR DIURNAL STORMS GROWTH...AIDED BY THE FOCUS OF THE SURFACE TROUGH WILL BE SOUTH OF TAMPA BAY. THIS BETTER ENVIRONMENT MAY REACH AS FAR NORTH AS THE I-4 CORRIDOR BY THE EVENING HOURS ALLOWING FOR SOME STORM DEVELOPMENT...BUT APPEARS ANY FURTHER NORTH INTO THE NATURE COAST...AND THE MOISTURE WILL ARRIVE A LITTLE TOO LATE FOR ANY SIGNIFICANT CONVECTIVE DEVELOPMENT. ANY SPEEDING UP OF THIS MOISTURE RETURN AND BETTER STORM CHANCES WILL NEED TO BE ADJUSTED NORTHWARD THURSDAY AFTERNOON/EVENING...BUT THE OUTLINED SCENARIO ABOVE IS HOW IT CURRENTLY LOOKS WITH THE AVAILABLE GUIDANCE...AND WILL BE THE FORECAST WE GO WITH EARLY THIS MORNING. RAIN CHANCES THE SECOND HALF OF THURSDAY WILL RANGE FROM 10% UP TOWARD CITRUS/LEVY COUNTIES...TO 30% ALONG THE I-4 CORRIDOR...AND THEN RANGE UP TO LIKELY 60% THUNDER CHANCES DOWN TOWARD CHARLOTTE/LEE COUNTIES. THEREAFTER IT APPEARS AS THROUGH EVERYONE WILL BE GETTING INTO THE HIGHER RAIN CHANCES BY FRIDAY AFTERNOON AND EVENING. ENJOY THE DRIER CONDITIONS AND HAVE A GREAT WEDNESDAY! && .LONG TERM (FRIDAY THROUGH NEXT TUESDAY)... AN UPPER RIDGE MEANDERS AROUND THE REGION...WHILE REMAINING GENERALLY CENTERED ABOVE THE SOUTHEAST U.S. COAST...THROUGH THE PERIOD AS IT DOMINATES THE LOCAL AREA. HOWEVER A WEAK UPPER TROUGH/LOW APPROACHES FROM THE EAST...REACHING THE BAHAMAS AS A TROUGH (GFS) OR CUBA AS A LOW (ECMWF) TUE. AT THE SURFACE A BROAD RIDGE STRETCHES ACROSS FL FROM THE ATLANTIC TO THE CENTRAL GULF. INITIALLY THE RIDGE AXIS... SOME WHAT ILL DEFINED...IS ACROSS CENTRAL FL BUT LIFTS UP TO ALONG THE GA/FL LINE FOR THE WEEKEND THEN DROPS BACK INTO NORTHERN FL FOR THE START OF NEXT WEEK. BOTH THE GFS AND ECMWF ARE SIMILAR WITH THE SURFACE FEATURES EXCEPT FOR THE GFS TRACKING AN INVERTED TROUGH...ON THE SOUTH SIDE OF THE RIDGE...INTO THE BAHAMAS TUE. THE FORECAST PHILOSOPHY FROM 24 HOURS AGO CONTINUES WITH LITTLE CHANGE. THE UPPER RIDGE WILL HELP KEEP TEMPERATURES ON THE WARM SIDE OF NORMAL...LOWS BY A DEGREE OR TWO AND HIGHS AROUND A COUPLE OF DEGREES. LOW LEVEL SOUTHEAST AND SOUTHERLY FLOW WILL RESULT IN ENOUGH MOISTURE...MODEL PWAT VALUES RUN IN THE 1.8 TO 2 INCH RANGE...FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. SOME DRIER AIR MAY WORK IN LATE MON AND TUE...IN THE GFS SOLUTION...BUT STILL ENOUGH FOR SCATTERED COVERAGE. THE GRADIENT STAYS RELAXED WITH SEA BREEZES SHIFTING THE FLOW TO ONSHORE IN THE AFTERNOONS... FOCUSING THE GREATEST COVERAGE INLAND BUT NEAR THE COAST. && .AVIATION... VFR CONDITIONS ACROSS THE REGION EARLY THIS MORNING. PATCHES OF CLOUDS HAVE BEEN MOVING NORTHEAST TO SOUTHWEST ACROSS THE CENTRAL PENINSULA WITH PERIOD OF BROKEN CIGS FOR KSRQ/KPIE/KTPA/KLAL...BUT BASES ARE GENERALLY ABOVE 5KFT. GENERAL VFR CONDITIONS WILL CONTINUE THROUGH THE DAYLIGHT HOURS. JUST A SLIGHT CHANCE A LATE DAY SHOWER FOR KFMY/KRSW. ALLOWED A SEA-BREEZE WINDS SHIFT LATE IN THE AFTERNOON FOR KTPA/KPIE/KSRQ. LESS CONFIDENT IN THE BREEZE REACHING KFMY/KRSW AND KEPT WINDS FROM THE EAST INTO THE EVENING HOURS. && .MARINE... THE GRADIENT REMAINS TIGHT ENOUGH EARLY THIS MORNING TO SUPPORT AREAS OF CAUTIONARY LEVEL WINDS OVER THE EASTERN GULF OF MEXICO...HOWEVER AS HURRICANE CRISTOBAL CONTINUES TO PULL FURTHER AWAY FROM THE REGION AND HIGH PRESSURE DIGS SOUTHWARD TOWARD THE AREA...THIS GRADIENT WILL BE RELAXING AND SHOULD SEE AN EARLY END TO THE CAUTIONARY CONDITIONS THIS MORNING. WINDS WILL SHIFT TO THE SOUTHEAST FOR THE LATER PORTION OF THE WEEK AS A WEAK SURFACE TROUGH PIVOTS NORTHWARD ACROSS THE CENTRAL AND EASTERN GULF OF MEXICO. ALTHOUGH WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW HEADLINE CRITERIA...THIS TROUGH WILL BRING GREATER COVERAGE OF SHOWERS AND STORMS TO THE COASTAL WATERS. && .FIRE WEATHER... ANOTHER GENERALLY DRY DAY WITH LITTLE IN THE WAY OF THUNDERSTORM ACTIVITY. RELATIVE HUMIDITY VALUES WILL BE LOW FOR LATE SUMMER...BUT ARE NOT EXPECTED TO DROP BELOW CRITICAL LEVELS. LOW LEVEL MOISTURE ALONG WITH THUNDERSTORM CHANCES WILL THEN QUICKLY INCREASE BACK TO NORMAL LEVELS FOR LATE AUGUST BY THE END OF THE WEEK. NO SIGNIFICANT FOG IS EXPECTED THE NEXT SEVERAL DAYS. && .PRELIMINARY POINT TEMPS/POPS... TPA 94 77 93 78 / 10 10 20 20 FMY 95 76 93 76 / 20 20 60 30 GIF 93 74 95 75 / 10 10 20 20 SRQ 92 75 92 77 / 10 10 40 30 BKV 94 70 95 73 / 10 10 20 20 SPG 93 80 93 80 / 10 10 30 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1008 PM CDT THU AUG 28 2014 .DISCUSSION... 714 PM CDT PAIR OF MCVS NOTED ON RADAR IMAGERY CONTINUE TO MOVE EASTWARD DRIVING SLOWLY DECAYING CONVECTIVE COMPLEX EASTWARD INTO OUR CWA EARLY THIS EVENING DESPITE THE MUCH MORE STABLE AND SOMEWHAT DRIER AIR MASS OVER THE REGION. HAVE ALREADY UPDATED PRECIP TRENDS A COUPLE TIME TO ACCOUNT FOR THE RAIN THIS EVENING. ANTICIPATE CONTINUED WEAKENING TREND...PARTICULARLY FROM THE NORTH...IN THIS AREA OF LEFT OVER RAIN AND EVEN SOME LINGERING THUNDER. THE THREAT OF THUNDER WITH THE NORTHERN MCV TRACKING CLOSE TO I-88 LOOKS TO END VERY SOON...WHILE THE CONVECTION WITH THE SOUTHERN MOST MCV LIES CLOSE ENOUGH TO MORE UNSTABLE AIR TO POTENTIALLY MAINTAIN THUNDERSTORMS ACROSS THE SOUTHERN TIER OF OUR CWA THE NEXT FEW HOURS. IN THE WAKE OF THESE MCVS...WHICH REALLY HAVENT BEEN HANDLED WELL BY NUMERICAL GUIDANCE...SHOULD SEE A PERIOD OF DRY CONDITIONS HOWEVER MODELS DO BREAK OUT ADDITIONAL CONVECTION OVERNIGHT WHICH ISN`T THAT UNREASONABLE GIVEN THE NORTHWARD ADVANCING WARM FRONT. IZZI //PREV DISCUSSION... 230 PM CDT VISIBLE IMAGERY THIS AFTERNOON SHOWS A MID/UPR LEVEL CLOUD DECK LIFTING NORTHEAST ACROSS NORTHERN IL. REMNANTS FROM A MORNING COMPLEX OF THUNDERSTORMS RESIDES OVER IOWA...WITH SOME CONVECTIVE LOOK TO THE CLOUDS LINGERING INTO THIS AFTN. SFC TEMPS ACROSS THE FORECAST AREA HAVE BEEN ABLE TO WARM INTO THE MID/UPR 70S. A FEW POINTS SOUTH OF PONTIAC TO KANKAKEE HAVE PUSHED TO ARND 80 DEG...BUT WITH THE LIGHT EASTERLY FLOW AT THE SFC SOME WEAK SUBSIDENCE HAS BEEN NOTED WITH DEW POINTS BEING PUSHED INTO THE LOW 50S ALONG THE LAKESHORE AND MID/UPR 50S INLAND. THE MAIN CHALLENGE FOR THIS EVENING WILL FOCUS ON CONVECTIVE CHANCES/COVERAGE...WHICH WILL CONTINUE THROUGH DAYBREAK FRI. GUIDANCE HAS CONTINUED TO BACK OFF ON THE ARRIVAL OF PRECIP INTO THE FORECAST AREA...WHICH SEEMS TO LINE UP RELATIVELY WELL WITH THE CURRENT TRENDS. THE FRONTAL BOUNDARY WILL SLOWLY LIFT NORTH THIS EVENING...BUT NOT EXPECTING MUCH IN THE WAY OF PRECIP UNTIL PERHAPS AFT 04Z WITH A GRADUAL UPGLIDE OF PARCELS ALLOWS FOR MOISTENING. SOME ELEVATED CONVECTION COULD BEGIN TO DEVELOP...ALTHOUGH NOT EXPECTING MUCH COVERAGE OVERNIGHT. THE FOCUS FOR SLIGHTLY BETTER PRECIP COVERAGE WILL REMAIN ALONG THE NORTHERN ROW OF COUNTIES IN NORTHERN IL...HOWEVER CLOSER TO DAYBREAK FRI IT APPEARS SOME PRECIP/CONVECTION COULD SAG SOUTHEAST AND CLIP NORTHEAST IL/NORTHWEST IN BEFORE DISSIPATING. WITH INCREASING CLOUD COVER TONIGHT...IT SHUD LIMIT HOW COOL TEMPS BECOME. SO HAVE MADE ONLY MINOR ADJUSTMENTS TO THE TEMPS WITH GENERALLY MID/UPR 60S FOR LOWS. BEACHLER FRIDAY AND FRIDAY NIGHT... CLOSED UPPER LOW CURRENTLY NEAR THE COLORADO FRONT RANGE WILL SLOWLY TRAVERSE EAST TOWARDS THE MID-MISSOURI VALLEY FRIDAY BECOMING AN OPEN WAVE. AT THE SURFACE...BROAD AND WEAK SURFACE LOW WILL LIFT INTO THE UPPER MIDWEST WHILE SOUTHWEST FLOW RAMPS UP THROUGH THE COLUMN AS THE WARM FRONT LIFTS INTO THE CENTRAL GREAT LAKES. HEAT AND HUMIDITY WILL MAKE A RETURN AS THIS OCCURS. H85 TEMPS WARMING TO AROUND 18C WILL HELP SUPPORT MID/UPPER 80S DURING THE DAY FRIDAY...AND SURFACE DEWPOINTS ARE PROGGED TO PUSH BACK INTO THE LOW POSSIBLY MID 70S. THIS WILL RESULT IN MODERATE INSTABILITY DEVELOPING DURING THE DAY...AND ONLY WEAKLY CAPPED DURING THE AFTERNOON AS BROAD HEIGHT FALLS ASSOCIATED WITH THE UPPER WAVE START TO OVERSPREAD THE AREA. THERE DOESNT SEEM TO BE MUCH FOCUS IN THE LOWER LEVELS SO WOULD EXPECT ONLY SCATTERED THUNDERSTORM DEVELOPMENT ACROSS THE REGION FRIDAY AFTERNOON/EVENING. UPPER WAVE BEGINS TO MOVE INTO THE UPPER MIDWEST TOMORROW NIGHT AND BROAD WARM ADVECTION OUT AHEAD DURING THE EVENING AND OVERNIGHT HOURS WILL HELP SUSTAIN SOME CONVECTION LATE BUT WOULD EXPECT SOME NOCTURNAL DOWNTICK IN ACTIVITY OVERNIGHT WITH THE LOW LEVEL JET FOCUSED WELL TO OUR NORTH. GFS/NAM SEEM TO BE OVERDOING POPS MUCH OF THE DAY AND NIGHT FRIDAY...AND OPTED TO LEAN CLOSER TO ECMWF THESE PERIODS. THIS WEEKEND... COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA STARTING VERY EARLY ON SATURDAY. WHILE NOT A FAVORABLE DIURNAL TIME...WE SHOULD STILL HAVE SOME VERY MODEST INSTABILITY IN PLACE THAT WILL SUPPORT SOME EARLY DAY THUNDERSTORMS ALONG THE FRONTAL BOUNDARY...WHICH WOULD BE ABLE TO EXPAND IN COVERAGE AS THE DAY PROGRESSES AND THE BOUNDARY LAYER WARMS. IN ADDITION...GUIDANCE SUGGESTS A SECOND SHORTWAVE WILL WRAP INTO THE AREA THAT WILL PROVIDE ADDITIONAL BROAD SCALE ASCENT. THE ECMWF IS ABOUT SIX HOURS SLOWER WITH THIS FEATURE COMPARED TO THE NAM/GFS...WITH THE GEM A COMPROMISE...SO THERE REMAINS SOME UNCERTAINTY IN TIMING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT SATURDAY NIGHT INTO SUNDAY AND WILL PROVIDE A BRIEF RESPITE FROM THE ACTIVE WEATHER. THE ATMOSPHERE LOOKS TO QUICKLY RELOAD HOWEVER WITH THERMAL RIDGE ONCE AGAIN STARTING TO TILT BACK OVER THE AREA WITH H85 TEMPS AROUND 20C BY LATER IN THE DAY SUNDAY. NEXT WEEK... AN ACTIVE PATTERN LOOKS TO PERSIST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH A SERIES OF WAVES PUSHING ACROSS THE REGION BRINGING CONTINUED PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. ANOTHER COLD FRONT WILL PUSH ACROSS THE AREA LATER ON MONDAY WITH THE FRONTAL BOUNDARY STALLING JUST TO OUR SOUTH. THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY ON HOW FAR NORTH THE BOUNDARY MAY LIFT WITH THE BEST PRECIP CHANCES FOCUSED IN THE VICINITY OF THE FRONT AS A SERIES OF UPPER LEVEL DISTURBANCES PUSH ACROSS THE AREA. PWATS REMAIN JUICY ALONG THE FRONT...AROUND TWO INCHES...AND GUIDANCE SUGGESTS THAT THERE COULD BE SEVERAL CONVECTIVE COMPLEXES NEXT WEEK WITH A CONCERN FOR HEAVY RAIN AND FLOODING SHOULD THIS PAN OUT. DEUBELBEISS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * ISOLATED SHRA/TSRA LATE TONIGHT INTO EARLY FRIDAY MORNING. * SCATTERED TSRA FRIDAY AFTERNOON/EARLY EVENING. * SOUTH WIND WITH GUSTS DEVELOPING TO 20KT MIDDAY FRI. KMD //DISCUSSION...UPDATED 00Z... CHALLENGING FORECAST FOR THE NEXT 24-30 HOURS. AREA OF SHOWERS WILL CONTINUE TO PUSH EASTWARD AND WEAKEN SOME THIS EVENING. THUNDER ACTIVITY LOOKS TO REMAIN SOUTH OF THE INTERSTATE 80 CORRIDOR ALONG A LINE FROM KVYS TO KLOT TO KGYY. CIGS AND VSBYS SHOULD GENERALLY REMAIN VFR THOUGH BRIEF MVFR VISBYS ARE POSSIBLE MAINLY WEST OF THE MAIN CHICAGO TERMINALS. EXPECTING A LULL THIS EVENING...THEN AS A WARM FRONT LIFTS THROUGH TONIGHT...ADDITIONAL CONVECTION IS EXPECTED IN NW IOWA AND SPREADING INTO WISCONSIN OVERNIGHT. AS AN UPPER RIDGE BUCKLES SOME LATE TONIGHT INTO EARLY FRIDAY...SOME OF THIS ACTIVITY MAY GRAZE NORTHEAST ILLINOIS IN THE 12Z-15Z TIME FRAME. INSTABILITY MAY SUPPORT SHRA WITH ISOLATED TS. INSTABILITY THEN INCREASES VERY QUICKLY ON FRIDAY AS WE GET IN THE WARM SECTOR AND DEWPOINTS RISE. UPPER HEIGHT FALLS COMBINED WITH PEAK HEATING SUGGESTS AFTERNOON AIR MASS THUNDERSTORMS THOUGH DIFFICULT ON TIMING. COULD BE THUNDERSTORMS AT ANY TIME FRIDAY AFTERNOON EARLY EVENING WITH NO OBVIOUS SURFACE FOCUS. WITH HIGH PRECIPITABLE WATER VALUES...HEAVY DOWNPOURS ARE POSSIBLE. KMD //ORD AND MDW CONFIDENCE...UPDATED 03Z... * LOW-MEDIUM IN PRECIP COVERAGE LATE TONIGHT INTO EARLY FRIDAY. * LOW IN THUNDER CHANCES/COVERAGE AND SPECIFIC TIMING FRIDAY AFTERNOON. * HIGH IN WIND DIR/SPEED AND TRENDS KMD //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... * SATURDAY...TSRA LIKELY. * SUNDAY...SLIGHT CHANCE OF TSRA. * MONDAY AND TUESDAY...CHANCE OF TSRA. * WEDNESDAY AND THURSDAY...SLIGHT CHANCE OF TSRA KMD && .MARINE... 123 PM CDT SURFACE HIGH PRESSURE OVER THE GREAT LAKES REGION THIS AFTERNOON WILL DRIFT TO THE EAST TONIGHT IN THE WAKE OF A DEPARTING UPPER TROUGH OVER NEW ENGLAND/QUEBEC...AND AHEAD OF ANOTHER SURFACE TROUGH AND WEAK COLD FRONT STRETCHING FROM FAR NORTHWEST ONTARIO TO THE CENTRAL PLAINS. WINDS ON LAKE MICHIGAN WILL SHIFT TO THE SOUTHEAST AND EVENTUALLY SOUTH HEADING INTO FRIDAY...AS AN AREA OF SURFACE LOW PRESSURE DEVELOPS ACROSS THE PLAINS AND LIFTS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. TIGHTENING OF THE PRESSURE GRADIENT SOUTHEAST OF THE LOW TRACK WILL RESULT IN S-SE WINDS INCREASING INTO THE 15-25 KT RANGE TONIGHT AND FRIDAY...GRADUALLY WEAKENING SATURDAY AS THE LOW MOVES OFF TO THE NORTHEAST AND A WEAK COLD FRONT TRAILS ACROSS THE LAKE FOLLOWED BY WEAK HIGH PRESSURE. THIS COLD FRONT APPEARS TO DISSIPATE OR STALL ACROSS FAR SOUTHERN LAKE MICHIGAN OR NORTHERN IL/IND LATE SATURDAY NIGHT OR EARLY SUNDAY BEFORE DEVELOPING BACK TO THE NORTH AS A WARM FRONT SUNDAY NIGHT AS ANOTHER AREA OF LOW PRESSURE DEVELOPS OVER THE PLAINS AND LIFTS NORTHEAST INTO THE WESTERN/NORTHERN LAKES LATE SUNDAY NIGHT INTO MONDAY. AGAIN...A TIGHTENING OF THE PRESSURE GRADIENT ALONG THE SOUTHEAST PERIPHERY OF THE LOW TRACK IS EXPECTED WITH WINDS AGAIN BECOMING SOUTHERLY INTO THE 15-25 KT RANGE ON MONDAY. ANOTHER TRAILING COLD FRONT WILL PASS ACROSS THE LAKE MONDAY NIGHT...WITH WEAK HIGH PRESSURE AND LIGHTER WINDS DEVELOPING TUESDAY. RATZER && .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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 720 PM CDT Thu Aug 28 2014 .SHORT TERM...(This evening through Friday) ISSUED AT 255 PM CDT THU AUG 28 2014 18z/1pm surface map shows warm front extending from northern Missouri into western Kentucky. Aloft...vigorous upper-level low is evident on water vapor imagery over eastern Colorado/western Kansas. Large cluster of showers/storms associated with the low developed along the front across Iowa last night and has since weakened as it lifted northeastward into drier air over the Upper Midwest/Great Lakes. Convection is still ongoing along outflow boundary from eastern Iowa into northern Missouri: however, most of this will remain W/NW of the KILX CWA late this afternoon into the early evening. Meanwhile, scattered convection is firing further south along the front across western Kentucky and this is expected to develop further north into central Illinois over the next couple of hours. HRRR has had a good handle on the convection and have followed its solution closely for the immediate short-term. Have therefore gone with scattered showers/thunder across all but the far NE CWA around Champaign and Danville this afternoon into the evening. Think convection will be diurnally driven and will dissipate shortly after sunset. As upper low slowly approaches from the west, corresponding downstream ridging will help push the warm front northward tonight into Friday. With strongest upper support remaining west of Illinois through the day, think convection will once again only be scattered in nature and primarily occur during peak heating. Have therefore gone with a mostly dry forecast during the morning, followed by chance PoPs during the afternoon. Best rain chances will be focused closer to the frontal boundary across the northern two-thirds of the CWA. High temperatures on Friday will be held down a bit by clouds/precip, but will still rise well into the 80s, with locations along/south of I-70 perhaps hitting the 90-degree mark. && .LONG TERM...(Friday night through Thursday) ISSUED AT 255 PM CDT THU AUG 28 2014 Upper wave currently over the Rockies expected to slowly move out and bring rain chances to the area, particularly Friday night and Saturday as the upper trof moves through the Midwest. Keeping the precip around on Saturday may result in slightly cooler temperatures by the afternoon. Once again, the cold front associated with the upper trof moves across the region, losing its distinct baroclinic zone and becoming more diffuse as it slows considerably just to the southeast near the Ohio River Valley. The remaining boundary will keep pops around for the areas in the southeastern portions of the state through the remains of the weekend until another larger trof moves across the country bringing more widespread rain and thunder for Sunday night into Monday. Signif differences between the ECMWF and the GFS with the GFS being weaker with the boundary and leaving a more stationary focus for prolonged showers...whereas the ECMWF is more progressive and dries out the region on Tuesday. At this point, the ECMWF builds a weak upper ridge into the Midwest and the GFS stays more active. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 705 PM CDT THU AUG 28 2014 The new 00Z TAF valid time is expected to be much like the past couple. Predominantly VFR/quiet weather conditions are expected. However, scattered, mainly diurnally driven showers/storms are possible. As such, it is difficult to pinpoint precipitation until it is closer to arrival time. So, have limited most mention to VCTS during the day (aside from a few TEMPOs in the first 6 hours based on radar trends. Storms, if they impact a terminal, may briefly reduce cigs/vsbys to MVFR or lower. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...HJS AVIATION...BAK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1238 AM CDT WED AUG 27 2014 .DISCUSSION... 255 PM CDT AS HAS BEEN THE NORM IN THE PAST WEEK TO TEN DAYS...THE PRIMARY FORECAST CHALLENGES ARE TRYING TO DETECT WHEN BETTER THUNDERSTORM CHANCES MAY BE AND WHAT INFLUENCE THOSE HAVE...IF ANY...ON TEMPERATURES. .TONIGHT... THE INITIAL SYNOPTIC COLD FRONT HAS APPEARED TO CLEAR THE FORECAST AREA. THIS SURGE WAS CONVECTIVELY ENHANCED AND LINGERING HIGH DEW POINT AIR...E.G. UPPER 60S TO LOWER 70S...REMAINS ACROSS THE SOUTH. THERE ALSO ARE ONE OR TWO WESTWARD-PROPAGATING OUTFLOW BOUNDARIES THAT ARE LIKELY TO LAST INTO LATE THIS AFTERNOON. CUMULUS HAS FORMED NEAR PONTIAC AND GIBSON CITY...AND BACK TOWARD PRINCETON TO MENDOTA...WITH THESE FEATURES. WOULD NOT BE TOTALLY SURPRISED TO SEE ISOLATED STORMS POP ON THESE AS MIXED LAYER INHIBITION APPEARS SHALLOW WITH RECOVERING TEMPERATURES INTO THE MID 80S AND EVEN 88 AT PONTIAC. A COUPLE SUBTLE SHORT WAVES ARE NOTED ON WATER VAPOR...WITH ONE A LITTLE BETTER DEFINED ON VISIBLE SATELLITE NEARING THE MISSISSIPPI RIVER FROM IA ASSOCIATED WITH A 35 KT 500MB SPEED MAXIMUM. THIS LOOKS TO PASS OVER NORTH CENTRAL IL EARLY THIS EVE AND COULD SEE SOME SHOWER/STORM ACTIVITY WITH THAT...ALTHOUGH CONFIDENCE IS LOW FOR SHORT TERM STORM CHANCES...SO HAVE KEPT POPS FAIRLY LOW. CONFLUENT 700-850MB FLOW CONTINUES OVERNIGHT WITH ANOTHER LITTLE RIPPLE IN THE FLOW FORECAST TO MOVE OVER THE AREA. SO CONTINUE CHANCE FOR A STORM THROUGH THE ENTIRE NIGHT...BUT NOT EXPECTING ANYTHING WIDESPREAD. INCOMING CLOUDS FROM THE DISTURBED MID-LEVEL FLOW SHOULD KEEP THE FOG THREAT MINIMAL...AND TEMP/DEW POINT SPREADS LOOK TO BE MODESTLY HIGH GOING INTO TONIGHT IN MOST AREAS...OUTSIDE OF THE FAR SOUTH. MTF .WEDNESDAY THROUGH TUESDAY... THE LONGWAVE PATTERN OVER THE CENTRAL CONUS HAS BECOME MORE ZONAL WITH TROPICAL SYSTEM OVER SERN ATLANTIC...NERN PACIFIC WHILE A BROAD HIGH SITS OVER THE SRN CONUS AND A CLOSED UPPER LOW SWINGS THROUGH THE GREAT BASIN. THE SENSIBLE WEATHER OVER THE CWA WILL CONTINUE TO BE UNSETTLED AS A STRONG SHORTWAVE QUICKLY MOVES ACROSS THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES WEDNESDAY. UPPER RIDGING SHOULD BUILD ACROSS THE MIDWEST ON THURSDAY AS MORE SHORT WAVE ENERGY OVERTOPS THE RIDGE AND TRACKS ACROSS THE UPPER MIDWEST AND THE LOWER GREAT LAKES REGIONS. BY THURSDAY NIGHT AND FRIDAY...THE UPPER RIDGE SHOULD BUILD TO THE EAST OF THE REGION AS THE UPPER LOW OVER THE GREAT BASIN FINALLY OPENS UP AND LIFTS EAST ACROSS THE CENTRAL PLAINS AS AN OPEN WAVE FRIDAY AND FRIDAY NIGHT. THIS WAVE WILL CROSS THE UPPER MIDWEST INTO THE WESTERN GREAT LAKES BY SUNDAY. THE LONGER RANGE GUIDANCE SUGGESTS THAT THIS WAVE WILL PHASE WITH ANOTHER NORTHERN STREAM SHORTWAVE OVER THE UPPER GREAT LAKES BY SUNDAY. THE PROGRESSIVE AND RELATIVELY LOW AMPLITUDE UPPER LEVEL PATTERN OVER THE CONUS WILL LEAD TO A CONTINUES ACTIVE WEATHER PATTERN FOR THE LOCAL AREA...WITH PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE PERIOD. THE SOUTHERN PORTIONS OF THE CWA WILL BE MORE FAVORABLE FOR ADDITIONAL PCPN WEDNESDAY AS SFC HIGH PRESSURE SPREADS ACROSS THE GREAT LAKES REGION AND THE OLD FRONTAL BOUNDARY LAYS OUT ALONG THE OHIO VALLEY INTO SRN ILLINOIS. AS A SFC LOW DEEPENS OVER THE CENTRAL PLAINS ON THURSDAY...IT WILL DRAG THE FRONT NORTH AGAIN AS A WARM FRONT...BRINGING GREATER CHANCES FOR MORE WIDESPREAD PCPN TO THE AREA FOR THURSDAY AND THURSDAY NIGHT. WHILE THE FRONT REMAINS TO THE SOUTH AND HIGH PRESSURE SPREADS ACROSS THE GREAT LAKES REGION...TEMPERATURES WILL DIP BACK INTO THE MIDDLE 70S ACROSS THE NORTHERN PORTIONS OF THE CWA WHILE THE SOUTHERN LOCATIONS MAY REACH THE LOWER 80S. BY FRIDAY...WHEN THE WARM FRONT LIFTS NORTH OF THE CWA...HOT AND HUMID CONDITIONS WILL RETURN...WITH HIGHS IN THE MIDDLE 80S...DEWPOINTS IN THE LOWER 70S AND MAX HEAT INDEX VALUES INTO THE LOWER 90S. THE DEVELOPING SFC LOW IS EXPECTED TO SLOWLY LIFT ACROSS THE UPPER MISSISSIPPI VALLEY ON SATURDAY...KEEPING THE LOCAL AREA UNDER WARM SECTOR AIR AHEAD OF AN ASSOCIATED COLD FRONT. WHILE THE AREA REMAINS IN THE WARM SECTOR THROUGH THE WEEKEND...THERE WILL CONTINUE TO BE CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS...BUT WITHOUT A STRONG FOCUSING MECHANISM...WILL KEEP POPS IN THE CHANCE RANGE. BY EARLY NEXT WEEK...THE LONG RANGE GUIDANCE IS SUGGESTING THAT THE COLD FRONT SHOULD FINALLY PUSH THROUGH THE AREA...BUT THERE SHOULD BE LITTLE IN THE WAY OF AIRMASS CHANGE WITH THE FROPA AS ANOTHER DEEPENING TROUGH OVER THE NORTHERN PLAINS SHOULD QUICKLY BRING A RETURN TO WARM...MOIST SOUTHERLY FLOW FOR EARLY NEXT WEEK...WHICH WILL...IN TURN...KEEP CONTINUES CHANCES FOR PCPN ACROSS THE REGION. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * POSSIBLE MVFR CIGS EARLY THIS MORNING. * EAST/NORTHEAST WINDS THRU THE PERIOD...POSSIBLY AROUND 10KT THIS AFTERNOON. CMS //DISCUSSION...UPDATED 06Z... HIGH PRESSURE OVER THE NORTHERN PLAINS WILL MOVE EAST ACROSS THE LAKES REGION LATER TODAY AND TONIGHT. THIS WILL MAINTAIN EAST/ NORTHEAST WINDS THROUGH THE PERIOD. SPEEDS COULD INCREASE TO 10KTS OR SLIGHTLY HIGHER THIS AFTERNOON INTO EARLY THIS EVENING WITH A POSSIBLE LAKE BREEZE. CIGS AROUND 3KFT HAVE DEVELOPED ACROSS NORTHEAST IL BUT APPEAR TO BE SHIFTING EAST AND FOR NOW WILL JUST CARRY SCT MENTION. APPEARS A BKN/OVC MID DECK WILL SPREAD ACROSS MUCH OF THE REGION OVERNIGHT AND CONTINUE INTO THIS AFTERNOON. SOME FOG IS POSSIBLE WHERE SKIES REMAIN MOSTLY CLEAR AND GENERALLY SOUTH AND SOUTHEAST OF THE TERMINALS. CONTINUED FOG MENTION AT GYY BUT CONFIDENCE TOO LOW ELSEWHERE. A FEW ECHOS SHOWING UP ON RADAR NEAR THE QUAD CITIES AND ITS POSSIBLE FOR A LIGHT SHOWER OR SOME SPRINKLES OUT OF THE MID DECK THRU MID MORNING. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW FOR MVFR CIGS EARLY THIS MORNING. * MEDIUM FOR WINDS THRU THE PERIOD. CMS //OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z... * THURSDAY THROUGH MONDAY...CHANCE OF TSRA. KJB && .MARINE... 250 PM CDT LOW PRESSURE CONTINUES TO TRACK OUT OF NORTHERN QUEBEC AS A TRAILING COLD FRONT EXTENDS SOUTHWEST THROUGH NORTHERN INDIANA AND INTO SOUTHERN ILLINOIS. THE FRONT SHOULD STALL OUT OVER THE OHIO VALLEY OVERNIGHT TONIGHT AND HIGH PRESSURE BUILDS ACROSS UPPER MISSISSIPPI VALLEY AND WESTERN GREAT LAKES. WINDS OVER THE LAKE HAVE BEEN DISRUPTED BY THUNDERSTORM ACTIVITY TODAY...BUT SHOULD SETTLE INTO A MORE NORTHERLY TO NORTHEASTERLY DIRECTION OVERNIGHT TONIGHT. THE HIGH IS EXPECTED TO BUILD ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT WHILE LOW PRESSURE DEEPENS OVER THE CENTRAL PLAINS. WINDS OVER THE NORTHERN PORTIONS OF THE LAKE SHOULD THEN BECOME SOMEWHAT VARIABLE IN DIRECTION AS THE CENTER OF THE HIGH MOVES OVER THE FAR NORTHERN PORTION OF THE LAKE...BUT THE SOUTHERN PORTIONS OF THE LAKE SHOULD MAINTAIN A NORTHEASTERLY TO EASTERLY FETCH. THE PERSISTENT NORTHEASTERLY TO EASTERLY FETCH SHOULD CAUSE WINDS TO PILE UP OVER THE WESTERN SHORE OF THE LAKE...APPROACHING 3-4FT AS WINDS REACH 10-20KT. THE HIGH WILL CONTINUE TO BUILD TO THE EAST THURSDAY AND FRIDAY AS LOW PRESSURE TRACKS NEWD ONTO THE UPPER MISSOURI VALLEY. THIS WILL...IN TURN...LIFT THE OLD FRONTAL BOUNDARY THAT HAD GONE STATIONARY OVER THE OHIO VALLEY TO LIFT NORTH AS A WARM FRONT TURING WINDS THROUGH SOUTHEASTERLY TO SOUTHERLY BY FRIDAY. AS HAS BEEN THE NORM IN THE PAST WEEK TO TEN DAYS...THE PRIMARY FORECAST CHALLENGES ARE MUCH WHAT THEY HAVE BEEN...TRYING TO DETECT WHEN BETTER THUNDERSTORM CHANCES MAY BE AND WHAT INFLUENCE THOSE CONVECTIVE CHANCES HAVE ON TEMPERATURES. KREIN && .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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1151 PM CDT Tue Aug 26 2014 .UPDATE... ISSUED AT 845 PM CDT TUE AUG 26 2014 Band of strong/severe storms has been slowly trudging southward along the frontal boundary roughly along the the I-72 corridor. The models are generally handling this convection extremely poorly, although the 21Z online HopWRF is doing a pretty decent job, with the NamDNG5 also in the general vicinity. The HopWRF shows a general push toward the I-70 corridor over the next couple hours, and there is a lingering outflow that extends from near Flora northwest toward Taylorville, so that could feed some additional development. The front will not be moving too much overnight, and the RAP and 18Z NAM show some redevelopment north of it after 2-3am. Have sent some updated grids/zones to significantly increase the PoP`s this evening with this convection. Have not looked too closely at the temperatures yet, so further updates may be needed once that is evaluated. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 316 PM CDT TUE AUG 26 2014 An outflow boundary is draped over the area this afternoon and this could be the focus for more showers and thunderstorm development this evening and into tonight. So will be keeping a chance pops in the forecast for tonight, but mainly along and northeast of I-74. By tomorrow, all models indicate a good chance of thunderstorms across most of the area through tomorrow afternoon. Things will then shift back to the west after that. Temps and dew points are remaining high so will keep the heat advisory and warning going through this evening. Temps will remain warm through tomorrow, but with clouds and pcpn, advisory/warning criteria for heat indices will not be met. Model guidance numbers look to be too warm. && .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 316 PM CDT TUE AUG 26 2014 Upper level ridging will be broken down, which will allow another cold front to move into the area late in the week. Unfortunately this means that the chance of showers and thunderstorms will continue into the weekend. Most of the pcpn chances will remain to the northwest or northern part of the CWA through Friday. Then when the front drops into the area Friday afternoon, the chance of thunderstorms will spread across the whole CWA for most of the weekend. There could be a break in the pcpn over some of the area Sunday night, but another frontal system will move into the region for the beginning of next week...so chance pops continue. Temps will cool through the period, but then warm back up during the beginning of next week. Model guidance still looks to be too warm. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) ISSUED AT 1150 PM CDT TUE AUG 26 2014 Predominantly VFR aviation weather conditions expected across the central Illinois terminals through the 06Z TAF valid time. Still looks like a brief period of MVFR fog is possible later tonight, although the convective debris cloud in the area make this a little less certain than it seemed earlier tonight. Precipitation for the period is likely to be quite tricky. Feel the bulk of the night should be dry, and much of Wednesday may be as well. However, with a weak cold front slipping south through the area, and/or the presence of outflow boundaries, and expected arrival of a weak upper wave Wednesday, feel a mention of VCSH or VCTS if warranted. Confidence in timing of any precipitation is too low to go with a tempo or predominant period. If convection were to impact a terminal directly, lower than VFR conditions are possible. Winds through the period should be light/variable away from any convection with weak boundaries in the vicinity. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEELHART SHORT TERM...HJS LONG TERM...AUTEN AVIATION...BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
657 PM CDT THU AUG 28 2014 .SHORT TERM /TONIGHT/... ISSUED AT 315 PM CDT THU AUG 28 2014 PRIMARY FORECAST QUESTION FOR TONIGHT IS COVERAGE AND TIMING OF PRECIPITATION. RECENT RADAR TRENDS AND HIGH RESOLUTION MODELS SUCH AS THE WRF AND HRRR HAVE INDICATED A SIGNIFICANT DECREASING TREND IN PRECIP COVERAGE LATE THIS AFTERNOON AND EVENING...HOWEVER MOST SHORT RANGE MODELS CONTINUE TO FORECAST AN INCREASE ONCE AGAIN AFTER DARK TONIGHT. THIS IS CONSISTENT WITH THE SYNOPTIC SCENARIO CHARACTERIZED BY BROAD UPPER LEVEL DIFFLUENCE OVER A SATURATED ATMOSPHERE. HAVE CARRIED GENERALLY CHANCE POPS/SCATTERED WORDING THROUGH THE NIGHT GIVEN THE SUPPORT FOR REDEVELOPMENT...BUT HAVE LITTLE CONFIDENCE IN DETAILS OF TIMING AND LOCATION THUS THE POP FORECAST IS BROADBRUSHED FOR NOW. OTHERWISE LITTLE CHANGE WAS MADE TO THE ONGOING FORECAST. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 315 PM CDT THU AUG 28 2014 WITH UPPER LEVEL TROUGH STILL WEST OF THE AREA THROUGH EARLY SATURDAY MORNING...LIKELY TO SEE SOME ADDITIONAL ROUNDS OF THUNDERSTORMS ACROSS THE REGION THROUGH THAT TIME. OVER THE NEXT 24 TO 36 HOURS...THE HIGHEST PRECIPITABLE WATER VALUES WILL GRADUALLY SHIFT EAST OF THE REGION AS H850 MOISTURE TRANSPORT BEGINS TO SHIFT EAST AS WELL. BY 12Z FRIDAY...ONE ADDITIONAL WAVE...THE KICKER WAVE...WILL BE LOCATED OVER SOUTHEAST KS/WESTERN MO. THIS SHOULD LIFT NORTHEAST DURING THE NEXT 24 HOURS RESULTING IN INCREASING LIFT OVER THE REGION FRIDAY AFTERNOON AND EVENING. IN COMBINATION WITH THAT A COLD FRONT AND UPPER LEVEL LOW OVER SOUTHERN CANADA WILL DRIFT SOUTHEAST AND ALSO AID IN DISPLACING THE TROUGH ACROSS THE GREAT PLAINS. THROUGH THE PERIOD FRIDAY INTO EARLY SATURDAY... ANOTHER HALF INCH TO INCH OF RAINFALL IS LIKELY TO FALL WITH THE HEAVIER TOTALS OVER THE NORTH AND NORTHEAST PORTION OF THE FORECAST AREA. WITH RAINFALL RATES SLOWING DOWN...FLASH FLOODING IS PROBABLY NO LONGER A THREAT...BUT SATURATED GROUND MAY LEAD TO SOME MINOR RUNOFF PROBLEMS AT TIMES INCLUDING SOME PONDING OF WATER AND MINOR STREET FLOODING IN AREAS OF POOR DRAINAGE. TEMPERATURES TOMORROW WILL LIKELY WARM A BIT IN THE SOUTHEAST IN THE LOWER 80S...AHEAD OF THE WAVE WITH WARM AIR ADVECTION AND SOME POTENTIAL BREAKS IN THE CLOUD COVER IN THE SOUTHEAST. AS THE COOL FRONT MOVES EAST PRECIP CHANCES SHOULD END ACROSS THE REGION SATURDAY MORNING WITH SOME SUNSHINE RETURNING TO THE AREA BY MORNING. HIGHS WILL BE SLIGHTLY WARMER...BUT STILL WITHIN THE A FEW DEGREES OF HIGHS OF FRIDAY WITH MORE SUNSHINE...BUT SOME SLIGHT COOL AIR ADVECTION. MODELS IN GENERAL AGREEMENT WITH THE NEXT STRONG WAVE EXPECTED TO ARRIVE BY SUNDAY AFTERNOON....WITH A RATHER WARM DAY AHEAD AS H850 RISE TO NEAR 20C BY AFTERNOON. THE GFS SHOWS THAT PWATS WILL ONCE AGAIN RISE TO NEAR OR SLIGHTLY ABOVE 2 INCHES ALONG THE BOUNDARY AS IT MOVES INTO WESTERN IOWA BY 00Z. UPPER LEVEL WIND FIELDS AGAIN SHOW A MODEST INCREASE AS A MODESTLY STRONG WAVE APPROACHES FROM THE SOUTHWEST WITH 0-6KM BULK SHEAR OVER 40 KTS ACROSS THE AREA. THIS SHOULD BE ENOUGH TO PROMOTE SEVERE STORMS DURING THE LATE AFTERNOON AND EVENING HOURS. ANOTHER ROUND OF STORMS WITH OVER AN INCH OF RAIN IN SOME OF THE HEAVIER STORMS IS EXPECTED. FINALLY...THE REMAINDER OF THE FORECAST SUGGESTS THAT A BREAK FROM THE ACTIVE WEATHER WILL RETURN FROM LATER ON MONDAY THROUGH WEDNESDAY...WITH SOME POTENTIAL FOR A QUICK MOVING STORM AGAIN BY THURSDAY. && .AVIATION...29/00Z ISSUED AT 657 PM CDT THU AUG 28 2014 ALL ELEMENTS WILL BE A CONCERN THROUGH THE PERIOD...ESPECIALLY TONIGHT. CONFIDENCE WILL BE LOW AS WELL DUE TO SCATTERED CONVECTION AND VARIABLE VSBYS AND CIGS. 00Z SURFACE ANALYSIS SHOWS WARM FRONT FROM NW INTO E CENTRAL IA WITH HIT TAFS N AND E OF THOSE LOCATIONS THE HARDEST WITH IFR/LIFR CONDITIONS BY EARLY FRI MORNING WITH AT LEAST MVFR LIKELY ELSEWHERE DUE TO HIGH LOW LEVEL MOISTURE LEVELS. EXPECT SCT CONVECTION MAINLY TONIGHT AND AGAIN FRI AFTERNOON. POSSIBLE OTHER PERIODS AS WELL BUT TRIED TO HIGHLIGHT THOSE RATHER THAN BLANKET THE ENTIRE PERIOD WITH VICINITY WORDING. && .HYDROLOGY... ISSUED AT 315 PM CDT THU AUG 28 2014 SEVERAL ADDITIONAL EPISODES OF RAIN ARE EXPECTED THROUGH SATURDAY MORNING AND AGAIN ANOTHER SUNDAY AFTERNOON THROUGH MONDAY MORNING. AT THIS TIME EXPECTED RAINFALL AMOUNTS THROUGH SATURDAY MORNING WITH EACH EVENT SHOULD BE LIGHT TO MODERATE. THIS WILL LIMIT THE LIKELIHOOD OF FLASH FLOODING BUT STILL HAVE SOME EFFECT ON RISES ON SMALL STREAM AND AREA RIVERS. THERE IS A GREATER RISK OF MORE SUBSTANTIAL RAINFALL OVER PORTIONS OF THE FORECAST AREA SUNDAY EVENING. THIS TIME PERIOD WILL BE MONITORED FOR BOTH SHORT TERM FLOODING AND RIVER FLOODING OVER THE UPCOMING HOLIDAY WEEKEND. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...LEE LONG TERM...REV AVIATION...SMALL HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
124 PM CDT WED AUG 27 2014 .UPDATE... ISSUED AT 1232 PM CDT WED AUG 27 2014 RECENT RUNS OF THE HRRR AND HOP-WRF SUGGEST SCATTERED SHOWERS AND ISOLATED STORMS WILL LINGER ALONG AND SOUTH OF THE HIGHWAY 34 CORRIDOR THROUGH MID TO LATE AFTERNOON. PER THE LATEST SWOMCD...AN ISOLATED NEAR SEVERE STORM IS NOT TOTALLY OUT OF THE QUESTION IN THE EXTREME SOUTH. OTHERWISE...MORE WIDESPREAD CONVECTION STILL ON TARGET FOR LATE TONIGHT INTO THURSDAY MORNING WITH SCATTERED COVERAGE LIKELY LINGERING INTO THE AFTERNOON. && .SYNOPSIS... ISSUED AT 331 AM CDT WED AUG 27 2014 AT 3 AM...MSAS SURFACE PRESSURE FIELDS INDICATED HIGH PRESSURE OVER NORTHERN MN...WITH THE SURFACE FRONT WELL SOUTH ALONG THE I-70 CORRIDOR IN IL AND MO. AREA RADARS SHOWED SCATTERED...ELEVATED WEAK SHOWERS STREAMING EAST ALONG THE I-80 CORRIDOR FROM DSM TO THE QUAD CITIES WITH A ISOLATED SHOWERS OVER SE IA AND W CENTRAL IL. A MORE SIGNIFICANT...AND SO FAR SLOW MOVING...MCS WAS ALONG THE IA/NE/MO BORDER AREA...IN AN AXIS OF MORE SIGNIFICANT 850 THETAE CONVERGENCE. VERY LIGHT NORTH TO NORTHEAST WINDS OUT OF THE MN HIGH WAS PULLING IN COOLER AND DRIER AIR AT THE LOW LEVELS...WITH WIDESPREAD TEMPERATURES IN THE MID TO UPPER 60S AND A FEW READINGS NEAR 70 IN THE FAR SOUTH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 331 AM CDT WED AUG 27 2014 IN THE NEAR TERM...ELEVATED THETAE CONVERGENCE FIELDS IN THE RAP...WHICH HAD A GOOD CORRELATION WITH THE STORMS IN SW IA...WOULD SUPPORT THE STORM CLUSTER SLOWLY DRIFTING EAST THROUGH SUNRISE...REACHING THE FAR SOUTHWEST AND SOUTH BEFORE DISSIPATING BY MID MORNING. ELSEWHERE...THERE IS NOT MUCH SUPPORT OR MID LEVEL INSTABILITY TO SUGGEST THE ELEVATED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE CENTRAL AND SOUTH WILL RAMP UP LIKE PREVIOUS MORNINGS AND WILL MAINTAIN LOW CHANCE POPS. HIGHER CHANCE POPS ARE MAINTAINED MAINLY SOUTH OF THE HIGHWAY 34 CORRIDOR IN SE IA...WHERE WEAK MOISTURE CONVERGENCE AT 850 MB CONTINUES THIS MORNING. BEYOND...RAIN CHANCES HAVE BEEN REMOVED OVER ALL BUT THE FAR SOUTH FROM LATE MORNING THROUGH AFTERNOON AS A LOW LEVEL EASTERLY FLOW CONTINUES TO ADVECT IN DRIER AIR UNDER A WEAK MID LEVEL RIDGE. TEMPERATURES WILL BE SIMILAR TO A BIT COOLER THAN YESTERDAY DUE TO THE EASTERLY FLOW AND LIKELY INCREASED CLOUD COVER. TONIGHT...ALL MODELS HAVE THE NEXT MCS DEVELOPING OVER WESTERN OR NW IA AROUND MIDNIGHT...EXPANDING EAST TOWARD MORNING. HAVE ADJUSTED POPS ACCORDINGLY...WITH MUCH SLOWER TIMING RESULTING IN A DRY NIGHT IN THE EAST AND LATER ONSET CENTRAL AND WEST. HEAVY RAINFALL DOES NOT LOOK TO BE A MAJOR THREAT AS MCS GENERATION AND MAINTENANCE TOOLS POINT TOWARD THE BEST FORCING NOT ADVANCING MUCH PAST NW OR POSSIBLY N CENTRAL IA BY 12Z. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 331 AM CDT WED AUG 27 2014 THERE SHOULD BE A RESPECTABLE THUNDERSTORM COMPLEX ACROSS NORTHERN IOWA THURSDAY MORNING WITH A WING OF CONVECTION MOVING ACROSS THE AREA. THE NORTHWEST HALF OF THE AREA HAS THE BETTER CHANCES FOR RAIN. BOUNDARIES LEFT OVER FROM THE MORNING STORM COMPLEX WILL PROVIDE THE FOCUS FOR SCATTERED CONVECTION IN THE AFTERNOON AND EVENING. ALTHOUGH THE SIGNAL IS NOT AS CLEAR...ANOTHER ORGANIZED THUNDERSTORM COMPLEX SHOULD DEVELOP WEST OF THE AREA THURSDAY EVENING AND MOVE EAST NORTHEAST LATE THURSDAY NIGHT INTO FRIDAY MORNING. THE NORTHWEST THIRD TO HALF OF THE AREA HAS THE BETTER CHANCES FOR RAIN. BOUNDARIES FROM THE FRIDAY MORNING STORM COMPLEX WOULD AGAIN PROVIDE THE FOCUS FOR SCATTERED CONVECTION THAT DEVELOPS FRIDAY AFTERNOON AND EVENING. LATE FRIDAY NIGHT ANOTHER FRONT OR BOUNDARY IS FORECAST TO BEGIN MOVING INTO THE AREA. THE COMBINATION OF MOISTURE AND FORCING SHOULD RESULT IN SCATTERED CONVECTION PERSISTING THROUGH SUNRISE SATURDAY. SATURDAY ON... THE OVERALL WEATHER PATTERN IS SUPPORTIVE OF NOCTURNAL THUNDERSTORM COMPLEXES ACROSS THE MIDWEST. WHERE EACH DEVELOPS AND MOVES AFFECTS SUBSEQUENT DEVELOPMENT. AS A RESULT...THERE WILL BE PERIODS OF DRY WEATHER THAT MAY BE 6-12 HOURS IN DURATION. TEMPERATURES SATURDAY THROUGH TUESDAY SHOULD BE NEAR NORMAL. THE MODEL CONSENSUS HAS CHANCE TO LIKELY POPS FOR SATURDAY AND SLIGHT CHANCE TO CHANCE POPS SATURDAY NIGHT. THE MODEL CONSENSUS HAS SLIGHT CHANCE POPS FOR THE AREA SUNDAY/SUNDAY NIGHT. SEVERAL MODELS ARE SUGGESTING HIGH PRESSURE MOVING THROUGH THE AREA ON SUNDAY WHICH MAY RESULT IN DRY CONDITIONS. MONDAY THROUGH TUESDAY THE MODEL CONSENSUS HAS CHANCE POPS FOR EACH 12 HOUR PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1232 PM CDT WED AUG 27 2014 ISOLD SHOWERS WILL CONTINUE INVOF KBRL THIS AFTERNOON. OTHERWISE...EXPECT VFR CONDITIONS UNTIL LATE TONIGHT...WHEN THUNDERSTORMS ARE FORECAST TO BECOME WIDESPREAD ACROSS EASTERN IOWA INTO NORTHWEST ILLINOIS. HAVE INTRODUCED PREVAILING TSRA GROUPS WITH MVFR CIGS/VSBYS AT KCID/KDBQ/KBRL BETWEEN 09Z-11Z. TIMING EXPECTED TO BE SLIGHTLY LATER AT KMLI. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...RP KINNEY SYNOPSIS...SHEETS SHORT TERM...SHEETS LONG TERM...08 AVIATION...RP KINNEY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
753 PM CDT THU AUG 28 2014 ...UPDATE FOR MESOSCALE TRENDS... .UPDATE... ISSUED AT 748 PM CDT THU AUG 28 2014 MADE SPATIOTEMPORAL ADJUSTMENTS OF POPS AND WX GRIDS BASED OFF RADAR TRENDS AS WELL AS HRRR GUIDANCE. CONVECTION IS STRUGGLING, AND NOT VERY CONFIDENT OF EASTWARD PROPAGATION GIVEN UPCOMING DECREASE IN DIURNAL INDUCED INSTABILITY AND LACK OF FORMIDABLE COLD POOL GENERATION FOR MCS LONGEVITY. 00Z KDDC RAOB IS CONSIDERABLY DRIER WITH A LOWER PWAT OF 1.03". && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 139 PM CDT THU AUG 28 2014 THERE IS A FRONT WHICH HAS BEEN NEARLY STATIONARY TODAY FROM JUST WEST OF TOPEKA SOUTH-SOUTHWEST TO NEAR ANTHONY, KS AND THEN FURTHER SOUTHWEST INTO SOUTHWESTERN OKLAHOMA. CONVECTION HAS BEEN ONGOING AND SPREADING OUT TODAY JUST EAST OF THIS CONVERGENCE BOUNDARY. ANOTHER SURFACE TROUGH IS QUICKLY MOVING EAST THROUGH OUR CWA, AND CROSSED DDC AT 1952Z. CLOUDS HAVE BEEN SLOWER TO CLEAR OUT IN OUR EASTERN CWA THAN IN THE WEST, BUT STILL THINK THERE WILL BE ENOUGH OF A CONVERCENCE BOUNDARY TO INITIATE SOME THUNDERSTORMS. AT THIS TIME, I DO NOT EXPECT ANY SEVERE STORMS, WITH THE NAM AND HRRR MODELS BOTH SHOWING AROUND 1200 TO 1400 J/KG OF MUCAPE THIS EVENING, AND THE BULK SHEAR VALUES IN THE 18 TO 22 KNOT RANGE. THERE IS A SMALL CHANCE FOR SOME SMALL HAIL AND DOWN BURST WINDS IN THE 50 MPH RANGE. I HAVE MIGRATED THE 50-60 PERCENT POPS FROM DDC TO PTT FROM 22Z TO 02Z. ALSO, THERE IS AN UPPER POOL OF COLD AIR COMING IN FROM COLORADO THIS EVENING, AND A FEW SHOWERS AND THUNDERSTORMS MAY TRIGGER OFF THE COLD POOL IN OUR WESTERN ZONES. THE HEAVIER RAIN CHANCES WILL BE IN OUR EASTERN 2-TIER OF COUNTIES, WHERE THE FRONT AND TROUGH ARE, DEW POINTS ARE MUCH HIGHER IN OUR EAST. I DO NOT EXPECT ANY POTENTIAL FLOODING PROBLEMS OF THE PAST TWO NIGHTS WHICH AFFECTED NESS, SCOTT AND TREGO COUNTIES. OVERNIGHT, THE UPPER COLD POOL WILL HELP TO DE-STABILIZE THE ATMOSPHERE, AND THE RAIN CHANCES WILL MOVE EAST TOWARDS MORNING, ALONG WITH THE UPPER COLD POOL. THE PRECIPITATION TYPE SHOULD BE MORE SHOWERY OVERNIGHT VERSUS THE THUNDERSTORM TYPE. WILL STILL MENTION THE CHANCE FOR SHOWERS AND ISOLATED THUNDER, BECAUSE IT WON`T TAKE MUCH OF AN UPDRAFT TO UPGRADE A SHOWER INTO A THUNDERSTORM. BY 12Z, MOST OF ANY CONVECTION WILL BE CONCENTRATED INTO OUR EASTERN ZONES, AND OUT OF OUR EASTERN ZONES BY 18Z FRIDAY. LOW TEMPERATURES TONIGHT SHOULD BE COOLER THAN LAST NIGHT, WITH MINS RANGING FROM THE UPPER 50S ALONG THE COLORADO BORDER TO THE MID 60S IN OUR EASTERN CWA FROM HAYS TO MEDICINE LODGE. FRIDAY`S TEMPERATURES SHOULD MATCH TODAY`S MAX TEMPS VERY SIMILARLY, AND BE BASICALLY IN THE MIDDLE TO UPPER 80S. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 205 PM CDT THU AUG 28 2014 MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH LIFTING NORTHEAST OUT OF THE CENTRAL PLAINS INTO THE UPPER MIDWEST SATURDAY WHILE WEAK UPPER LEVEL RIDGING BEGINS TO MOVE OUT OF THE ROCKIES INTO THE WESTERN HIGH PLAINS. ALONG WITH A FAIRLY WEAK FLOW ALOFT, DRIER CONDITIONS ARE LIKELY THROUGH LATE SATURDAY AFTERNOON. PRECIP CHANCES PICK UP A LITTLE SATURDAY NIGHT AS AN UPPER LEVEL TROUGH MOVES EAST-SOUTHEAST ACROSS THE PACIFIC NORTHWEST INTO THE GREAT BASIN REGION. A SERIES OF H5 VORT MAXIMA WILL BEGIN TO EJECT OUT OF THE ROCKIES INTO THE WESTERN HIGH PLAINS AS A LOW LEVEL SOUTHEASTERLY UPSLOPE FLOW SETS UP ACROSS EASTERN AND EXTREME WESTERN KANSAS. ALTHOUGH THE FLOW ALOFT WILL REMAIN FAIRLY WEAK, MODEST INSTABILITY WITH CAPE VALUES AROUND 500 TO 1000 J/KG AND FAVORABLE ENOUGH DIRECTIONAL SHEAR WILL BE PRESENT TO SUPPORT THE POTENTIAL FOR ISOLATED THUNDERSTORMS ACROSS THE HIGH PLAINS IN THE VICINITY OF A DEVELOPING LEE SIDE TROUGH. WIDESPREAD SEVERE IS UNLIKELY. PRECIP CHANCES MAY PICK UP A LITTLE MORE LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT AS AN OPEN SHORTWAVE TRANSITIONS EASTWARD ACROSS THE NORTHERN ROCKIES INTO INTO THE NORTHERN PLAINS. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH SOUTHEASTWARD INTO WESTERN KANSAS LATE IN THE DAY WHILE A PREVAILING SOUTHEASTERLY FLOW NEAR THE SURFACE CONTINUES TO DRAW MOISTURE UP INTO MUCH OF KANSAS. MEANWHILE, A +90KT UPPER LEVEL JET ASSOCIATED WITH THE OPEN WAVE IS PROJECTED TO DIG SOUTHEAST ACROSS THE NORTHERN ROCKIES NOSING INTO THE HIGH PLAINS OF WESTERN NEBRASKA AND POSSIBLY NORTHERN PORTIONS OF WESTERN KANSAS. AS A RESULT, THUNDERSTORMS ARE LIKELY TO FIRE UP ALONG AND AHEAD OF THE FRONT AS IT PUSHES EASTWARD INTO THE UPPER MIDWEST SUNDAY NIGHT. HOWEVER, THUNDERSTORM CHANCES MAY BE MORE LIMITED FURTHER SOUTH ALONG THE FRONT INTO KANSAS WITH WEAKER DYNAMIC SUPPORT ALOFT. THE BETTER CHANCE FOR CONVECTION WILL REMAIN ACROSS OUR NORTHEAST IN CENTRAL KANSAS WHERE LOW LEVEL FORCING WILL BE MORE IDEAL NORTHEAST OF A DEVELOPING SURFACE LOW ACROSS EXTREME SOUTHWEST KANSAS. ALTHOUGH LESS CERTAIN, THUNDERSTORMS MAY BE POSSIBLE AGAIN MONDAY NIGHT INTO EARLY TUESDAY AS THE AFOREMENTIONED COLD FRONT IS FORECAST TO STALL OUT SOMEWHERE GENERALLY ALONG THE OKLAHOMA BORDER. TEMPERATURES ARE EXPECTED TO BE NEAR THE SEASONAL SATURDAY AS SURFACE PRESSURE BEGINS TO FALL ACROSS EASTERN COLORADO. ALTHOUGH THIS WILL HELP QUICKLY RETURN A LOW LEVEL SOUTHEASTERLY FLOW TO WESTERN KANSAS BY SATURDAY AFTERNOON, LITTLE CHANGE IS EXPECTED TO THE OVERALL AIR MASS IN PLACE ACROSS THE REGION. LOOK FOR HIGHS ONLY UP INTO THE MID TO UPPER 80S(F) IN CENTRAL KANSAS WITH THE LOWER 90S(F) POSSIBLE IN EXTREME SOUTHWEST KANSAS WHERE SOME WARM AIR ADVECTION IS LIKELY BY SATURDAY AFTERNOON. THE WARMING TREND WILL CONTINUE INTO SUNDAY AS THE PREVAILING SOUTHERLY FLOW DRAWS WARMER AIR NORTHWARD. WIDESPREAD 90S(F) ARE LIKELY TO FINISH OUT THE WEEKEND AS A RESULT. COOLER TEMPERATURES ARRIVE MONDAY IN WAKE OF A COLD FRONT PUSHING THROUGH WESTERN KANSAS BY MID DAY DROPPING HIGHS BACK DOWN INTO THE 80S(F) TO START THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 600 PM CDT THU AUG 28 2014 THE BEST CHANCE FOR VCTS WILL BE NEAR KGCK/KHYS. HAVE LOWER CONFIDENCE OF VCTS FOR KDDC. TEMPORARILY REDUCED CIGS/VIS IS POSSIBLE IF A HEAVY THUNDERSTORM CORE TRACKS DIRECTLY OVER A TERMINAL, BUT CONFIDENCE IS LOW AND LONG TERM FORECAST TRENDS DO NOT SUGGEST AS SUCH. WINDS WILL BE VARIABLE THIS EVENING THEN NORTHWESTERLY 5-10 KT TOMORROW. && .PRELIMINARY POINT TEMPS/POPS... DDC 64 86 61 90 / 40 10 10 10 GCK 62 86 59 91 / 40 10 10 10 EHA 60 88 61 91 / 30 10 10 10 LBL 62 87 61 91 / 20 10 10 10 HYS 64 85 61 89 / 20 10 10 10 P28 68 87 66 90 / 50 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SUGDEN SHORT TERM...BURKE LONG TERM...JJOHNSON AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
132 PM CDT WED AUG 27 2014 ...UPDATE TO LONG TERM... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CDT WED AUG 27 2014 SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN A SOUTHWEST FLOW WILL CROSS THE CENTRAL PLAINS OVER THE NEXT 36 TO 48 HOURS AS THE MAIN UPPER LEVEL TROUGH MOVES SLOWLY EAST ACROSS THE FOUR CORNERS REGION. EARLIER THIS MORNING THE WATER VAPOR LOOP, AND 00Z WEDNESDAY UPPER AIR ANALYSIS PLACED ONE OF THE UPPER WAVES WERE LOCATED OVER NORTHEAST NEW MEXICO. RADAR MOSAIC AND SURFACE OBSERVATION INDICATED SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AHEAD OF THIS FEATURE ACROSS THE OKLAHOMA AND TEXAS PANHANDLE. NAM, GFS, AND HRRR WERE ALL IN GOOD AGREEMENT IN MOVING THIS AREA OF PRECIPITATION ACROSS WESTERN KANSAS DURING THE EARLY MORNING HOURS AND BASED ON 06Z VERIFICATION OF THE UPPER WAVE AND AREA FAVORABLE FOR PRECIPITATION THESE MODELS APPEAR TO HAVE A GOOD HANDLE ON THIS EARLY MORNING EVENT. WILL THEREFORE KEEP HIGH CHANCE OR EVEN LIKELY WORDING FOR THUNDERSTORMS THROUGH AT LEAST 15Z ACROSS NORTH CENTRAL AND MUCH OF WESTERN KANSAS AS THE UPPER WAVE PASSES. AS THIS FIRST SYSTEM LIFTS NORTHEAST TOWARDS SOUTHERN NEBRASKA LATER THIS MORNING...A SECOND UPPER LEVEL DISTURBANCE WILL BEGIN TO APPROACH THE AREA FROM THE SOUTHWEST. THIS NEXT SYSTEM APPEARS TO BE LOCATED NEAR THE NOSE OF AN 300MB JET STREAK AND IS CURRENTLY FORECAST TO CROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. GIVEN THE LOCATION OF AN UPPER LEVEL JET LATE TODAY/EARLY EVENING ALONG WITH MOISTURE, AND INSTABILITY AHEAD OF THIS NEXT DISTURBANCE WILL INCREASE PRECIPITATION CHANCES DURING THE AFTERNOON AND EARLY EVENING. MAIN HAZARD CURRENTLY APPEARS TO BE PERIODS OF HEAVY RAINFALL, HOWEVER A FEW OF THE STRONGER THUNDERSTORMS IN WEST CENTRAL AND PARTS OF NORTH CENTRAL KANSAS MAY ALSO PRODUCE HAIL AND STRONG GUSTY WINDS. AS FOR TEMPERATURES TODAY WILL UNDERCUT GUIDANCE AND TREND TOWARDS WHAT THE 850MB 00Z THURSDAY MIX DOWN TEMPERATURES SUGGESTED FOR HIGHS. GIVEN THE EXPECTED CLOUD COVER AND THE 00Z 850MB TEMPERATURES WILL FAVOR AFTERNOON TEMPERATURES MAINLY IN THE MID 80S ACROSS WEST CENTRAL KANSAS AND UPPER 80S TO NEAR 90 ELSEWHERE. IN SOUTH CENTRAL KANSAS WHERE MORE SUN AND LESS CLOUDS ARE EXPECTED WILL TREND SLIGHTLY WARMER. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 128 PM CDT WED AUG 27 2014 SHOWERS AND ISOLATED THUNDERSTORMS WILL LINGER ACROSS CENTRAL AND EASTERN PORTIONS OF WESTERN KANSAS FRIDAY AS AN UPPER LEVEL SHORTWAVE PUSHES EASTWARD OUT OF THE WESTERN HIGH PLAINS INTO THE CENTRAL PLAINS EARLY IN THE PERIOD. AS THE UPPER LEVEL SHORTWAVE MOVES ACROSS THE REGION, A PREVAILING SOUTHEASTERLY FLOW WILL CONTINUE TO DRAW MOISTURE UP INTO CENTRAL KANSAS AHEAD OF A SURFACE TROUGH EDGING EASTWARD ACROSS THE AREA. MEANWHILE, A +60KT UPPER LEVEL JET CORE ASSOCIATED WITH THE SHORTWAVE IS PROJECTED TO LIFT NORTHEAST AS IT SHIFTS EAST ACROSS WESTERN AND CENTRAL KANSAS. ALONG WITH THE INCREASED DYNAMIC SUPPORT ALOFT PRESENT, SHOWERS AND THUNDERSTORMS ARE LIKELY EARLY FRIDAY ACROSS CENTRAL KANSAS IN A CORRIDOR OF INCREASED INSTABILITY ALONG AND AHEAD OF THE SURFACE TROUGH AS IT MOVES THROUGH. DRIER CONDITIONS ARE THEN EXPECTED ACROSS WESTERN KANSAS THROUGH THE WEEKEND AS THE UPPER LEVEL SHORTWAVE KICKS EAST OUT OF THE CENTRAL PLAINS WHILE WEAK RIDGING ALOFT MOVES OUT OF THE ROCKIES INTO THE WESTERN HIGH PLAINS. BELOW NORMAL TEMPERATURES ARE EXPECTED FRIDAY AS SLIGHTLY COOLER AIR BEGINS TO FILTER SOUTHWARD INTO WESTERN KANSAS IN WAKE OF THE SURFACE TROUGH PASSING THROUGH. THE GFS AND ECMWF SHOW H85 TEMPERATURES AROUND 20C ACROSS CENTRAL KANSAS WITH NEAR 25C IN EXTREME SOUTHWEST KANSAS. ALTHOUGH INCREASED CLOUD COVER MAY BE PRESENT EARLY IN THE DAY, LOOK FOR HIGHS GENERALLY UP INTO THE LOWER TO MID 80S(F) FRIDAY AFTERNOON. A WARMING TREND IS THEN EXPECTED THROUGH THE WEEKEND AS A WEAK UPPER LEVEL RIDGE TRANSITIONS EAST ACROSS THE CENTRAL PLAINS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1210 PM CDT WED AUG 27 2014 THERE IS PLENTY OF MOISTURE IN THE AIR, AND MID LEVEL CLOUDS BLANKET THE TAF AREA. A RATHER STRONG UPPER LEVEL WAVE WILL MOVE IN FROM THE NORTHWEST THIS EVENING, AND THERE IS A CHANCE FOR SOME STRONG STORMS AT EACH TAF SITE FROM APPROXIMATELY 21Z-03Z. CIGS MAY GO DOWN TO OVC050 AND VSBYS TO 4-5SM IN RAIN AND FOG, BUT IFR CONDITIONS ARE NOT ANTICIPATED. OVERNIGHT, EXPECT SOUTHEAST WINDS OF 10 TO 13 KNOTS AND CIGS IN THE BKN090 RANGE. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 86 63 83 / 50 50 70 40 GCK 66 84 62 83 / 60 50 60 20 EHA 64 83 61 82 / 50 50 60 20 LBL 67 86 64 82 / 50 50 60 20 HYS 68 85 65 83 / 60 50 60 40 P28 71 88 67 85 / 40 60 70 40 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...JJOHNSON AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1217 PM CDT WED AUG 27 2014 ...UPDATED FOR THE AVIATION DISCUSSION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CDT WED AUG 27 2014 SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN A SOUTHWEST FLOW WILL CROSS THE CENTRAL PLAINS OVER THE NEXT 36 TO 48 HOURS AS THE MAIN UPPER LEVEL TROUGH MOVES SLOWLY EAST ACROSS THE FOUR CORNERS REGION. EARLIER THIS MORNING THE WATER VAPOR LOOP, AND 00Z WEDNESDAY UPPER AIR ANALYSIS PLACED ONE OF THE UPPER WAVES WERE LOCATED OVER NORTHEAST NEW MEXICO. RADAR MOSAIC AND SURFACE OBSERVATION INDICATED SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AHEAD OF THIS FEATURE ACROSS THE OKLAHOMA AND TEXAS PANHANDLE. NAM, GFS, AND HRRR WERE ALL IN GOOD AGREEMENT IN MOVING THIS AREA OF PRECIPITATION ACROSS WESTERN KANSAS DURING THE EARLY MORNING HOURS AND BASED ON 06Z VERIFICATION OF THE UPPER WAVE AND AREA FAVORABLE FOR PRECIPITATION THESE MODELS APPEAR TO HAVE A GOOD HANDLE ON THIS EARLY MORNING EVENT. WILL THEREFORE KEEP HIGH CHANCE OR EVEN LIKELY WORDING FOR THUNDERSTORMS THROUGH AT LEAST 15Z ACROSS NORTH CENTRAL AND MUCH OF WESTERN KANSAS AS THE UPPER WAVE PASSES. AS THIS FIRST SYSTEM LIFTS NORTHEAST TOWARDS SOUTHERN NEBRASKA LATER THIS MORNING...A SECOND UPPER LEVEL DISTURBANCE WILL BEGIN TO APPROACH THE AREA FROM THE SOUTHWEST. THIS NEXT SYSTEM APPEARS TO BE LOCATED NEAR THE NOSE OF AN 300MB JET STREAK AND IS CURRENTLY FORECAST TO CROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. GIVEN THE LOCATION OF AN UPPER LEVEL JET LATE TODAY/EARLY EVENING ALONG WITH MOISTURE, AND INSTABILITY AHEAD OF THIS NEXT DISTURBANCE WILL INCREASE PRECIPITATION CHANCES DURING THE AFTERNOON AND EARLY EVENING. MAIN HAZARD CURRENTLY APPEARS TO BE PERIODS OF HEAVY RAINFALL, HOWEVER A FEW OF THE STRONGER THUNDERSTORMS IN WEST CENTRAL AND PARTS OF NORTH CENTRAL KANSAS MAY ALSO PRODUCE HAIL AND STRONG GUSTY WINDS. AS FOR TEMPERATURES TODAY WILL UNDERCUT GUIDANCE AND TREND TOWARDS WHAT THE 850MB 00Z THURSDAY MIX DOWN TEMPERATURES SUGGESTED FOR HIGHS. GIVEN THE EXPECTED CLOUD COVER AND THE 00Z 850MB TEMPERATURES WILL FAVOR AFTERNOON TEMPERATURES MAINLY IN THE MID 80S ACROSS WEST CENTRAL KANSAS AND UPPER 80S TO NEAR 90 ELSEWHERE. IN SOUTH CENTRAL KANSAS WHERE MORE SUN AND LESS CLOUDS ARE EXPECTED WILL TREND SLIGHTLY WARMER. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 306 AM CDT WED AUG 27 2014 AN UPPER LEVEL LOW WILL MOVE THROUGH THE CENTRAL ROCKIES THURSDAY THEN THROUGH THE CENTRAL PLAINS FRIDAY BEFORE WEAKENING AND EXITING INTO THE UPPER MISSISSIPPI VALLEY ON SATURDAY. THIS FEATURE WILL HELP PUSH A SURFACE COLD FRONT THROUGH WESTERN KANSAS THURSDAY INTO THURSDAY NIGHT. THE FRONT WILL THEN BE POSITIONED ACROSS CENTRAL KANSAS ON FRIDAY. LOWER AND MID LEVELS OF THE ATMOSPHERE WILL BE SATURATED AND WITH THE LIFT CREATED BY THIS SYSTEM, MOSTLY CLOUDY SKIES ARE EXPECTED THROUGH FRIDAY. STORM CHANCES WILL ALSO BE PRESENT THROUGH FRIDAY WITH THE BEST CHANCE OCCURRING THURSDAY AFTERNOON INTO THURSDAY NIGHT WHEN THE COLD FRONT MOVES ACROSS THE CWA. THUNDERSTORM CHANCES END FROM WEST TO EAST ON FRIDAY THEN BE CONFINED ACROSS CENTRAL AND EASTERN KANSAS BY SATURDAY. A DRIER PERIOD IS THEN EXPECTED THROUGH THIS WEEKEND INTO THE BEGINNING OF NEXT WEEK AS A WEAK UPPER LEVEL RIDGE MOVING THROUGH THE ROCKIES AND HIGH PRESSURE BUILDING ACROSS THE AREA AT THE SURFACE. MEANWHILE, A UPPER LEVEL LONG WAVE TROUGH IS PROGGED TO DIG INTO THE PACIFIC NORTHWEST AND INTER-MOUNTAIN WEST THIS WEEKEND INTO THE FIRST PART OF NEXT WEEK, THEN MOVE INTO THE THE NORTHERN PLAINS BY MID WEEK. THIS COULD BRING A CHANCE OF THUNDERSTORMS TUESDAY INTO WEDNESDAY, HOWEVER, IT IS TOO FAR OUT TO PIN POINT EXACTLY THE BEST LIFT WILL OCCUR. OTHERWISE EXPECT PARTLY CLOUDY SKIES SATURDAY THROUGH THE MIDDLE OF NEXT WEEK. AS FOR TEMPERATURES, HIGHS LOOK TO BE IN THE 80S THURSDAY THROUGH SATURDAY THEN INCREASE INTO THE LOWER TO MID 90S ON SUNDAY. HIGHS MONDAY THROUGH WEDNESDAY ARE FORECASTED TO RANGE FROM THE UPPER 80S ACROSS WEST CENTRAL KANSAS TO MID 90S ACROSS SOUTH CENTRAL KANSAS. LOWS THROUGH THE EXTENDED PERIOD LOOK TO GENERALLY BE IN THE 60S WITH A FEW LOWER 70S ACROSS SOUTH CENTRAL KANSAS MONDAY AND TUESDAY MORNINGS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1210 PM CDT WED AUG 27 2014 THERE IS PLENTY OF MOISTURE IN THE AIR, AND MID LEVEL CLOUDS BLANKET THE TAF AREA. A RATHER STRONG UPPER LEVEL WAVE WILL MOVE IN FROM THE NORTHWEST THIS EVENING, AND THERE IS A CHANCE FOR SOME STRONG STORMS AT EACH TAF SITE FROM APPROXIMATELY 21Z-03Z. CIGS MAY GO DOWN TO OVC050 AND VSBYS TO 4-5SM IN RAIN AND FOG, BUT IFR CONDITIONS ARE NOT ANTICIPATED. OVERNIGHT, EXPECT SOUTHEAST WINDS OF 10 TO 13 KNOTS AND CIGS IN THE BKN090 RANGE. && .PRELIMINARY POINT TEMPS/POPS... DDC 90 67 86 63 / 60 50 50 70 GCK 87 66 84 62 / 50 60 50 60 EHA 87 64 83 61 / 40 50 40 60 LBL 91 67 86 64 / 40 50 40 60 HYS 88 68 85 65 / 50 60 50 60 P28 93 71 88 67 / 20 40 60 70 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...HOVORKA_42 AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
622 AM CDT WED AUG 27 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CDT WED AUG 27 2014 SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN A SOUTHWEST FLOW WILL CROSS THE CENTRAL PLAINS OVER THE NEXT 36 TO 48 HOURS AS THE MAIN UPPER LEVEL TROUGH MOVES SLOWLY EAST ACROSS THE FOUR CORNERS REGION. EARLIER THIS MORNING THE WATER VAPOR LOOP, AND 00Z WEDNESDAY UPPER AIR ANALYSIS PLACED ONE OF THE UPPER WAVES WERE LOCATED OVER NORTHEAST NEW MEXICO. RADAR MOSAIC AND SURFACE OBSERVATION INDICATED SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AHEAD OF THIS FEATURE ACROSS THE OKLAHOMA AND TEXAS PANHANDLE. NAM, GFS, AND HRRR WERE ALL IN GOOD AGREEMENT IN MOVING THIS AREA OF PRECIPITATION ACROSS WESTERN KANSAS DURING THE EARLY MORNING HOURS AND BASED ON 06Z VERIFICATION OF THE UPPER WAVE AND AREA FAVORABLE FOR PRECIPITATION THESE MODELS APPEAR TO HAVE A GOOD HANDLE ON THIS EARLY MORNING EVENT. WILL THEREFORE KEEP HIGH CHANCE OR EVEN LIKELY WORDING FOR THUNDERSTORMS THROUGH AT LEAST 15Z ACROSS NORTH CENTRAL AND MUCH OF WESTERN KANSAS AS THE UPPER WAVE PASSES. AS THIS FIRST SYSTEM LIFTS NORTHEAST TOWARDS SOUTHERN NEBRASKA LATER THIS MORNING...A SECOND UPPER LEVEL DISTURBANCE WILL BEGIN TO APPROACH THE AREA FROM THE SOUTHWEST. THIS NEXT SYSTEM APPEARS TO BE LOCATED NEAR THE NOSE OF AN 300MB JET STREAK AND IS CURRENTLY FORECAST TO CROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. GIVEN THE LOCATION OF AN UPPER LEVEL JET LATE TODAY/EARLY EVENING ALONG WITH MOISTURE, AND INSTABILITY AHEAD OF THIS NEXT DISTURBANCE WILL INCREASE PRECIPITATION CHANCES DURING THE AFTERNOON AND EARLY EVENING. MAIN HAZARD CURRENTLY APPEARS TO BE PERIODS OF HEAVY RAINFALL, HOWEVER A FEW OF THE STRONGER THUNDERSTORMS IN WEST CENTRAL AND PARTS OF NORTH CENTRAL KANSAS MAY ALSO PRODUCE HAIL AND STRONG GUSTY WINDS. AS FOR TEMPERATURES TODAY WILL UNDERCUT GUIDANCE AND TREND TOWARDS WHAT THE 850MB 00Z THURSDAY MIX DOWN TEMPERATURES SUGGESTED FOR HIGHS. GIVEN THE EXPECTED CLOUD COVER AND THE 00Z 850MB TEMPERATURES WILL FAVOR AFTERNOON TEMPERATURES MAINLY IN THE MID 80S ACROSS WEST CENTRAL KANSAS AND UPPER 80S TO NEAR 90 ELSEWHERE. IN SOUTH CENTRAL KANSAS WHERE MORE SUN AND LESS CLOUDS ARE EXPECTED WILL TREND SLIGHTLY WARMER. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 306 AM CDT WED AUG 27 2014 AN UPPER LEVEL LOW WILL MOVE THROUGH THE CENTRAL ROCKIES THURSDAY THEN THROUGH THE CENTRAL PLAINS FRIDAY BEFORE WEAKENING AND EXITING INTO THE UPPER MISSISSIPPI VALLEY ON SATURDAY. THIS FEATURE WILL HELP PUSH A SURFACE COLD FRONT THROUGH WESTERN KANSAS THURSDAY INTO THURSDAY NIGHT. THE FRONT WILL THEN BE POSITIONED ACROSS CENTRAL KANSAS ON FRIDAY. LOWER AND MID LEVELS OF THE ATMOSPHERE WILL BE SATURATED AND WITH THE LIFT CREATED BY THIS SYSTEM, MOSTLY CLOUDY SKIES ARE EXPECTED THROUGH FRIDAY. STORM CHANCES WILL ALSO BE PRESENT THROUGH FRIDAY WITH THE BEST CHANCE OCCURRING THURSDAY AFTERNOON INTO THURSDAY NIGHT WHEN THE COLD FRONT MOVES ACROSS THE CWA. THUNDERSTORM CHANCES END FROM WEST TO EAST ON FRIDAY THEN BE CONFINED ACROSS CENTRAL AND EASTERN KANSAS BY SATURDAY. A DRIER PERIOD IS THEN EXPECTED THROUGH THIS WEEKEND INTO THE BEGINNING OF NEXT WEEK AS A WEAK UPPER LEVEL RIDGE MOVING THROUGH THE ROCKIES AND HIGH PRESSURE BUILDING ACROSS THE AREA AT THE SURFACE. MEANWHILE, A UPPER LEVEL LONG WAVE TROUGH IS PROGGED TO DIG INTO THE PACIFIC NORTHWEST AND INTER-MOUNTAIN WEST THIS WEEKEND INTO THE FIRST PART OF NEXT WEEK, THEN MOVE INTO THE THE NORTHERN PLAINS BY MID WEEK. THIS COULD BRING A CHANCE OF THUNDERSTORMS TUESDAY INTO WEDNESDAY, HOWEVER, IT IS TOO FAR OUT TO PIN POINT EXACTLY THE BEST LIFT WILL OCCUR. OTHERWISE EXPECT PARTLY CLOUDY SKIES SATURDAY THROUGH THE MIDDLE OF NEXT WEEK. AS FOR TEMPERATURES, HIGHS LOOK TO BE IN THE 80S THURSDAY THROUGH SATURDAY THEN INCREASE INTO THE LOWER TO MID 90S ON SUNDAY. HIGHS MONDAY THROUGH WEDNESDAY ARE FORECASTED TO RANGE FROM THE UPPER 80S ACROSS WEST CENTRAL KANSAS TO MID 90S ACROSS SOUTH CENTRAL KANSAS. LOWS THROUGH THE EXTENDED PERIOD LOOK TO GENERALLY BE IN THE 60S WITH A FEW LOWER 70S ACROSS SOUTH CENTRAL KANSAS MONDAY AND TUESDAY MORNINGS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 619 AM CDT WED AUG 27 2014 MVFR CONDITIONS WILL BE OBSERVED ACROSS THE DDC TERMINAL OVER THE NEXT COUPLE OF HOURS AS LIGHT TO MODERATE RAIN REDUCE VISIBILITIESBELOW 5 MILES. OTHERWISE EXPECT VFR CONDITIONS ACROSS THE TAF SITES. WINDS WILL GENERALLY BE FROM A SOUTHERLY DIRECTION AROUND 10 KNOTS THIS MORNING INCREASING TO AROUND 13 KNOTS BY LATE MORNING WITH HIGHER GUSTS. A CHANCE OF THUNDERSTORMS IS IN THE FORECAST LATE THIS AFTERNOON INTO THIS EVENING AND HAVE PLACED A TEMPO GROUP TO REFLECT THIS. && .PRELIMINARY POINT TEMPS/POPS... DDC 90 67 86 64 / 60 50 50 50 GCK 87 66 84 63 / 50 60 50 60 EHA 87 64 83 62 / 40 50 40 40 LBL 91 67 86 65 / 40 50 40 40 HYS 88 68 85 66 / 50 60 50 70 P28 93 71 88 68 / 20 40 60 60 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...HOVORKA_42 AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
307 AM CDT WED AUG 27 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CDT WED AUG 27 2014 SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN A SOUTHWEST FLOW WILL CROSS THE CENTRAL PLAINS OVER THE NEXT 36 TO 48 HOURS AS THE MAIN UPPER LEVEL TROUGH MOVES SLOWLY EAST ACROSS THE FOUR CORNERS REGION. EARLIER THIS MORNING THE WATER VAPOR LOOP, AND 00Z WEDNESDAY UPPER AIR ANALYSIS PLACED ONE OF THE UPPER WAVES WERE LOCATED OVER NORTHEAST NEW MEXICO. RADAR MOSAIC AND SURFACE OBSERVATION INDICATED SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AHEAD OF THIS FEATURE ACROSS THE OKLAHOMA AND TEXAS PANHANDLE. NAM, GFS, AND HRRR WERE ALL IN GOOD AGREEMENT IN MOVING THIS AREA OF PRECIPITATION ACROSS WESTERN KANSAS DURING THE EARLY MORNING HOURS AND BASED ON 06Z VERIFICATION OF THE UPPER WAVE AND AREA FAVORABLE FOR PRECIPITATION THESE MODELS APPEAR TO HAVE A GOOD HANDLE ON THIS EARLY MORNING EVENT. WILL THEREFORE KEEP HIGH CHANCE OR EVEN LIKELY WORDING FOR THUNDERSTORMS THROUGH AT LEAST 15Z ACROSS NORTH CENTRAL AND MUCH OF WESTERN KANSAS AS THE UPPER WAVE PASSES. AS THIS FIRST SYSTEM LIFTS NORTHEAST TOWARDS SOUTHERN NEBRASKA LATER THIS MORNING...A SECOND UPPER LEVEL DISTURBANCE WILL BEGIN TO APPROACH THE AREA FROM THE SOUTHWEST. THIS NEXT SYSTEM APPEARS TO BE LOCATED NEAR THE NOSE OF AN 300MB JET STREAK AND IS CURRENTLY FORECAST TO CROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. GIVEN THE LOCATION OF AN UPPER LEVEL JET LATE TODAY/EARLY EVENING ALONG WITH MOISTURE, AND INSTABILITY AHEAD OF THIS NEXT DISTURBANCE WILL INCREASE PRECIPITATION CHANCES DURING THE AFTERNOON AND EARLY EVENING. MAIN HAZARD CURRENTLY APPEARS TO BE PERIODS OF HEAVY RAINFALL, HOWEVER A FEW OF THE STRONGER THUNDERSTORMS IN WEST CENTRAL AND PARTS OF NORTH CENTRAL KANSAS MAY ALSO PRODUCE HAIL AND STRONG GUSTY WINDS. AS FOR TEMPERATURES TODAY WILL UNDERCUT GUIDANCE AND TREND TOWARDS WHAT THE 850MB 00Z THURSDAY MIX DOWN TEMPERATURES SUGGESTED FOR HIGHS. GIVEN THE EXPECTED CLOUD COVER AND THE 00Z 850MB TEMPERATURES WILL FAVOR AFTERNOON TEMPERATURES MAINLY IN THE MID 80S ACROSS WEST CENTRAL KANSAS AND UPPER 80S TO NEAR 90 ELSEWHERE. IN SOUTH CENTRAL KANSAS WHERE MORE SUN AND LESS CLOUDS ARE EXPECTED WILL TREND SLIGHTLY WARMER. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 306 AM CDT WED AUG 27 2014 AN UPPER LEVEL LOW WILL MOVE THROUGH THE CENTRAL ROCKIES THURSDAY THEN THROUGH THE CENTRAL PLAINS FRIDAY BEFORE WEAKENING AND EXITING INTO THE UPPER MISSISSIPPI VALLEY ON SATURDAY. THIS FEATURE WILL HELP PUSH A SURFACE COLD FRONT THROUGH WESTERN KANSAS THURSDAY INTO THURSDAY NIGHT. THE FRONT WILL THEN BE POSITIONED ACROSS CENTRAL KANSAS ON FRIDAY. LOWER AND MID LEVELS OF THE ATMOSPHERE WILL BE SATURATED AND WITH THE LIFT CREATED BY THIS SYSTEM, MOSTLY CLOUDY SKIES ARE EXPECTED THROUGH FRIDAY. STORM CHANCES WILL ALSO BE PRESENT THROUGH FRIDAY WITH THE BEST CHANCE OCCURRING THURSDAY AFTERNOON INTO THURSDAY NIGHT WHEN THE COLD FRONT MOVES ACROSS THE CWA. THUNDERSTORM CHANCES END FROM WEST TO EAST ON FRIDAY THEN BE CONFINED ACROSS CENTRAL AND EASTERN KANSAS BY SATURDAY. A DRIER PERIOD IS THEN EXPECTED THROUGH THIS WEEKEND INTO THE BEGINNING OF NEXT WEEK AS A WEAK UPPER LEVEL RIDGE MOVING THROUGH THE ROCKIES AND HIGH PRESSURE BUILDING ACROSS THE AREA AT THE SURFACE. MEANWHILE, A UPPER LEVEL LONG WAVE TROUGH IS PROGGED TO DIG INTO THE PACIFIC NORTHWEST AND INTER-MOUNTAIN WEST THIS WEEKEND INTO THE FIRST PART OF NEXT WEEK, THEN MOVE INTO THE THE NORTHERN PLAINS BY MID WEEK. THIS COULD BRING A CHANCE OF THUNDERSTORMS TUESDAY INTO WEDNESDAY, HOWEVER, IT IS TOO FAR OUT TO PIN POINT EXACTLY THE BEST LIFT WILL OCCUR. OTHERWISE EXPECT PARTLY CLOUDY SKIES SATURDAY THROUGH THE MIDDLE OF NEXT WEEK. AS FOR TEMPERATURES, HIGHS LOOK TO BE IN THE 80S THURSDAY THROUGH SATURDAY THEN INCREASE INTO THE LOWER TO MID 90S ON SUNDAY. HIGHS MONDAY THROUGH WEDNESDAY ARE FORECASTED TO RANGE FROM THE UPPER 80S ACROSS WEST CENTRAL KANSAS TO MID 90S ACROSS SOUTH CENTRAL KANSAS. LOWS THROUGH THE EXTENDED PERIOD LOOK TO GENERALLY BE IN THE 60S WITH A FEW LOWER 70S ACROSS SOUTH CENTRAL KANSAS MONDAY AND TUESDAY MORNINGS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1208 AM CDT WED AUG 27 2014 WATER VAPOR LOOP AND 00Z UPPER AIR ANALYSIS INDICATING AT LEAST TWO SUBTLE UPPER LEVEL WAVES WILL BE CROSSING SOUTHWEST KANSAS OVER THE NEXT 18 TO 24 HOURS. FIRST OF THESE TWO SYSTEMS WILL CROSS SOUTHWEST KANSAS LATE TONIGHT/EARLY WEDNESDAY. THE SECOND WILL CROSS WESTERN KANSAS DURING THE AFTERNOON/EARLY EVENING. BASED ON THE MOISTURE AND LIFT AHEAD OF THESE TWO UPPER LEVEL DISTURBANCES THERE WILL BE A CHANCE THUNDERSTORMS IN ALL THREE TAFS EARLY THIS MORNING AND AGAIN LATER THIS AFTERNOON/EVENING. 00Z NAM BUFR SOUNDINGS INDICATING THE CLOUD BASES THROUGH WEDNESDAY AFTERNOON WILL BE AT OR ABOVE THE 3000FT AGL LEVEL. GUSTY WINDS WINDS WILL BE POSSIBLE FROM ANY THUNDERSTORM EARLY THIS MORNING OR LATER THIS AFTERNOON, HOWEVER THE PREVAILING WINDS WILL BE SOUTHERLY AT 10 KNOTS OR LESS THROUGH EARLY WEDNESDAY MORNING. GUSTY SOUTH/SOUTHEAST WINDS AT AROUND 15 KNOTS WILL DEVELOP BY LATE MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 88 67 86 64 / 30 50 50 50 GCK 85 66 84 63 / 50 60 40 40 EHA 85 64 83 62 / 40 50 40 40 LBL 88 67 86 65 / 40 50 40 40 HYS 87 68 85 66 / 50 60 50 50 P28 92 71 88 68 / 20 40 60 60 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...HOVORKA_42 AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
203 AM CDT WED AUG 27 2014 ...UPDATED SHORT TERM DISCUSSION .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 202 AM CDT WED AUG 27 2014 SUBTLE UPPER LEVEL DISTURBANCES EMBEDDED IN A SOUTHWEST FLOW WILL CROSS THE CENTRAL PLAINS OVER THE NEXT 36 TO 48 HOURS AS THE MAIN UPPER LEVEL TROUGH MOVES SLOWLY EAST ACROSS THE FOUR CORNERS REGION. EARLIER THIS MORNING THE WATER VAPOR LOOP, AND 00Z WEDNESDAY UPPER AIR ANALYSIS PLACED ONE OF THE UPPER WAVES WERE LOCATED OVER NORTHEAST NEW MEXICO. RADAR MOSAIC AND SURFACE OBSERVATION INDICATED SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AHEAD OF THIS FEATURE ACROSS THE OKLAHOMA AND TEXAS PANHANDLE. NAM, GFS, AND HRRR WERE ALL IN GOOD AGREEMENT IN MOVING THIS AREA OF PRECIPITATION ACROSS WESTERN KANSAS DURING THE EARLY MORNING HOURS AND BASED ON 06Z VERIFICATION OF THE UPPER WAVE AND AREA FAVORABLE FOR PRECIPITATION THESE MODELS APPEAR TO HAVE A GOOD HANDLE ON THIS EARLY MORNING EVENT. WILL THEREFORE KEEP HIGH CHANCE OR EVEN LIKELY WORDING FOR THUNDERSTORMS THROUGH AT LEAST 15Z ACROSS NORTH CENTRAL AND MUCH OF WESTERN KANSAS AS THE UPPER WAVE PASSES. AS THIS FIRST SYSTEM LIFTS NORTHEAST TOWARDS SOUTHERN NEBRASKA LATER THIS MORNING...A SECOND UPPER LEVEL DISTURBANCE WILL BEGIN TO APPROACH THE AREA FROM THE SOUTHWEST. THIS NEXT SYSTEM APPEARS TO BE LOCATED NEAR THE NOSE OF AN 300MB JET STREAK AND IS CURRENTLY FORECAST TO CROSS WESTERN KANSAS LATE THIS AFTERNOON AND EARLY THIS EVENING. GIVEN THE LOCATION OF AN UPPER LEVEL JET LATE TODAY/EARLY EVENING ALONG WITH MOISTURE, AND INSTABILITY AHEAD OF THIS NEXT DISTURBANCE WILL INCREASE PRECIPITATION CHANCES DURING THE AFTERNOON AND EARLY EVENING. MAIN HAZARD CURRENTLY APPEARS TO BE PERIODS OF HEAVY RAINFALL, HOWEVER A FEW OF THE STRONGER THUNDERSTORMS IN WEST CENTRAL AND PARTS OF NORTH CENTRAL KANSAS MAY ALSO PRODUCE HAIL AND STRONG GUSTY WINDS. AS FOR TEMPERATURES TODAY WILL UNDERCUT GUIDANCE AND TREND TOWARDS WHAT THE 850MB 00Z THURSDAY MIX DOWN TEMPERATURES SUGGESTED FOR HIGHS. GIVEN THE EXPECTED CLOUD COVER AND THE 00Z 850MB TEMPERATURES WILL FAVOR AFTERNOON TEMPERATURES MAINLY IN THE MID 80S ACROSS WEST CENTRAL KANSAS AND UPPER 80S TO NEAR 90 ELSEWHERE. IN SOUTH CENTRAL KANSAS WHERE MORE SUN AND LESS CLOUDS ARE EXPECTED WILL TREND SLIGHTLY WARMER. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 120 PM CDT TUE AUG 26 2014 MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE PUSHING EASTWARD OUT OF THE CENTRAL AND SOUTHERN ROCKIES INTO THE WESTERN HIGH PLAINS THURSDAY BRINGING ADDITIONAL PRECIP CHANCES TO PORTIONS OF WESTERN AND CENTRAL KANSAS EARLY IN THE PERIOD. AS THE UPPER LEVEL SHORTWAVE KICKS OUT OF THE ROCKIES, A PREVAILING SURFACE TROUGH ACROSS EASTERN COLORADO WILL BEGIN TO SHIFT EASTWARD INTO EXTREME WESTERN KANSAS PROVIDING INCREASED CONVERGENCE ACROSS THE AREA. MEANWHILE, AMPLE MOISTURE WILL CONTINUE TO POOL AHEAD OF THE ADVANCING SURFACE TROUGH WITHIN A SOUTHEASTERLY UPSLOPE FLOW WITH H85 DEWPOINTS UP NEAR 15C. ADDITIONALLY, A +70KT UPPER LEVEL JET LIFTING NORTHEAST OUT OF THE APPROACHING TROUGH AXIS, IS PROJECTED TO MOVE EASTWARD ACROSS WESTERN KANSAS TOWARD THURSDAY AFTERNOON. AS LOW/MID LEVEL LAPSE RATES STEEPEN THURSDAY AFTERNOON, THUNDERSTORMS WILL BE POSSIBLE ACROSS CENTRAL AND PORTIONS OF WESTERN KANSAS AHEAD OF THE SURFACE TROUGH IN A CORRIDOR OF INCREASED INSTABILITY. ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT EXPECTED, ENOUGH DEEP LAYER SHEAR AND INSTABILITY WILL BE PRESENT TO SUPPORT THE POTENTIAL FOR STRONG TO MARGINALLY SEVERE STORMS. THE FOCUS FOR PRECIP SHIFTS EASTWARD MORE INTO CENTRAL AND EASTERN KANSAS FRIDAY AS THE SURFACE TROUGH MIGRATES FURTHER EAST. DRIER CONDITIONS WILL RETURN TO WESTERN KANSAS OVER THE WEEKEND AS THE UPPER LEVEL SHORTWAVE PUSHES FURTHER EAST INTO THE MISSISSIPPI RIVER VALLEY WHILE WEAK RIDGING ALOFT MOVES OUT OF THE ROCKIES INTO THE WESTERN HIGH PLAINS. NEAR NORMAL TEMPERATURES ARE EXPECTED THURSDAY EVEN AS THE SURFACE TROUGH PUSHES ACROSS WESTERN KANSAS THROUGHOUT THE DAY. THE GFS AND ECMWF SHOW H85 TEMPERATURES GENERALLY AROUND 20C ACROSS CENTRAL AND SOUTHWEST KANSAS WITH THE WARMEST AIR IN PLACE ACROSS SOUTH CENTRAL KANSAS AHEAD OF THE TROUGH. LOOK FOR HIGHS WELL UP INTO THE 80S(F) THURSDAY AFTERNOON WITH NEAR 90F STILL POSSIBLE IN SOUTH CENTRAL KANSAS. SLIGHTLY COOLER TEMPERATURES ARE LIKELY FRIDAY AS A NORTHERLY FLOW SETS UP BEHIND THE DEPARTING SURFACE TROUGH. COOLER AIR WILL FILTER SOUTHWARD INTO CENTRAL AND WESTERN KANSAS AS A RESULT WITH H85 TEMPERATURES DROPPING BELOW 20C NEAR THE I-70 CORRIDOR. HIGHS ONLY UP INTO THE LOWER TO MID 80S(F) ARE EXPECTED FRIDAY AFTERNOON. TEMPERATURES WILL REBOUND SOMEWHAT INTO THE WEEKEND AS THE AFOREMENTIONED WEAK UPPER LEVEL RIDGE TRANSITIONS EAST ACROSS THE CENTRAL PLAINS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1208 AM CDT WED AUG 27 2014 WATER VAPOR LOOP AND 00Z UPPER AIR ANALYSIS INDICATING AT LEAST TWO SUBTLE UPPER LEVEL WAVES WILL BE CROSSING SOUTHWEST KANSAS OVER THE NEXT 18 TO 24 HOURS. FIRST OF THESE TWO SYSTEMS WILL CROSS SOUTHWEST KANSAS LATE TONIGHT/EARLY WEDNESDAY. THE SECOND WILL CROSS WESTERN KANSAS DURING THE AFTERNOON/EARLY EVENING. BASED ON THE MOISTURE AND LIFT AHEAD OF THESE TWO UPPER LEVEL DISTURBANCES THERE WILL BE A CHANCE THUNDERSTORMS IN ALL THREE TAFS EARLY THIS MORNING AND AGAIN LATER THIS AFTERNOON/EVENING. 00Z NAM BUFR SOUNDINGS INDICATING THE CLOUD BASES THROUGH WEDNESDAY AFTERNOON WILL BE AT OR ABOVE THE 3000FT AGL LEVEL. GUSTY WINDS WINDS WILL BE POSSIBLE FROM ANY THUNDERSTORM EARLY THIS MORNING OR LATER THIS AFTERNOON, HOWEVER THE PREVAILING WINDS WILL BE SOUTHERLY AT 10 KNOTS OR LESS THROUGH EARLY WEDNESDAY MORNING. GUSTY SOUTH/SOUTHEAST WINDS AT AROUND 15 KNOTS WILL DEVELOP BY LATE MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 92 68 87 66 / 60 50 50 50 GCK 90 66 85 63 / 40 50 50 40 EHA 89 64 84 62 / 40 50 50 40 LBL 92 67 87 64 / 40 50 50 40 HYS 91 68 86 66 / 60 60 50 50 P28 96 71 89 69 / 30 50 60 60 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BURGERT LONG TERM...JJOHNSON AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
946 PM EDT THU AUG 28 2014 .SYNOPSIS... A WEAK COLD FRONT SETTLES SOUTH INTO NORTH CAROLINA OVERNIGHT INTO FRIDAY...BEFORE LIFTING NORTH AS A WARM FRONT FRIDAY NIGHT AND SATURDAY. A WEAK TROUGH DEVELOPS ON SUNDAY AND SHOULD RESULT IN INCREASING PRECIPITATION CHANCES LATER IN THE DAY. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... WK SFC BNDRY RMNS DRAPED FM ALG THE VA/NC BORDER IN SRN/SE VA...TO WCNTRL VA. ISOLD/SCT CONVECTION CONTS TO TRACK SLOLY SE THROUGH AREAS OF THE PIEDMONT W OF I 95. DEWPTS RMN FM THE U60S TO L70S S ALONG/S OF THAT BNDRY...AND MNLY IN THE L60S N (ALONG NNE WNDS). 00Z/29 RUC CONT TO PUSH THAT CONVECTION TO THE SE INTO NE NC AFT MIDNIGHT AS THE BNDRY SINKS S. WILL KEEP POPS FOR THOSE AREAS UNTIL AFT MDNGT...ELSW JUST CLR-PC. MAY NEED TO ADD FOG OVR SRN AREAS OF THE FA...THOUGH XPCG A GRADUAL LWRG OF DEWPTS FM THE NNE AS THE BNDRY SINKS TO THE S. LO TEMPS FM THE L60S N TO THE U60S/ARND 70F S. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... A WEAK FRONTAL BOUNDARY REMAINS STALLED ACROSS NRN NC FRIDAY AS A SFC HIGH PRESSURE OVER NEW ENGLAND EXTENDS SWD INTO THE MID ATLANTIC REGION. ONCE AGAIN...THE WEAK FRONTAL BOUNDARY SHOULD PROVIDE JUST ENOUGH FORCING/INSTABILITY FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS INVOF THE STALLED FRONT (STILL PRIMARILY SOUTH OF INTERSTATE 64 WITH BEST PRECIP CHANCES ALONG THE VA/NC BORDER INTO NE NC). THE AXIS OF THE SFC HIGH SITS OVER CNTRL NY TO CNTRL VA FRIDAY MORNING AND THEN PIVOTS EWD ALONG THE COAST FROM NC TO NEW ENGLAND BY FRIDAY EVENING. THIS WILL BRING A SLIGHTLY COOLER AIRMASS ACROSS THE NRN HALF OF THE CWA WHILE TEMPS STAY ON THE COOLER SIDE INVOF THE FRONT DUE TO PARTLY TO MOSTLY CLOUDY SKIES. IT IS DIFFICULT TO SAY EXACTLY WHERE THE DIVIDING LINE WILL SET-UP BTWN HIGHS IN THE MID-UPPER 80S SW TO LOW-MID 80S NE. CURRENT FORECAST THINKING GENERALLY KEEPS THE COOLER HIGHS ACROSS THE NRN NECK/MD LOWER EASTERN SHORE/ACCOMACK COUNTY VA...DESPITE MOSTLY SUNNY SKIES ACROSS THESE AREAS. THE STALLED BOUNDARY LIFTS NWD AS A WARM FRONT FRIDAY NIGHT INTO SATURDAY AS THE SFC HIGH OVER NEW ENGLAND SLIDES OFF THE NEW ENGLAND COAST LATE FRIDAY NIGHT INTO SATURDAY. AS IT DOES SO... WILL NEED TO CARRY SLIGHT CHC POPS ACROSS MUCH OF THE FA FRIDAY NIGHT...WITH THE BEST CHANCES FOR PRECIPITATION (STILL IN THE 20 PERCENT RANGE) ALONG AND N-NE OF INTERSTATE 64 DURING MOST OF SATURDAY. RETURN FLOW ALSO DEVELOPS ON SATURDAY AS THE RIDGE AXIS MOVES OFFSHORE...BRINGING WARMER TEMPS AND A MORE HUMID AIRMASS INTO THE REGION. LOWS FRIDAY NIGHT IN THE LOW-MID 60S NORTH AND UPPER 60S TO LOWER 70S SOUTH. HIGHS SATURDAY AROUND 90/MID-UPPER 80S IMMEDIATE COAST. A GENERALLY DRY FORECAST FOR SATURDAY NIGHT INTO THE FIRST HALF OF SUNDAY AS HIGH PRESSURE DOMINATES AT THE SFC AND ALOFT. LOWS SATURDAY NIGHT AROUND 70 UNDER PARTLY CLOUDY SKIES. A WEAK TROUGH DEVELOPS ALONG THE LEE OF THE APPALACHIANS ON SUNDAY AND MAY BE JUST ENOUGH OF A FOCUSING MECHANISM FOR SHOWERS AND THUNDERSTORMS DURING THE AFTN/EVENING AS WEAK SHORTWAVE ENERGY STREAMS ALONG THE PERIPHERY OF AN UPPER LEVEL RIDGE...WHICH SHOULD BE CENTERED OVER THE WRN ATLANTIC AS A BERMUDA HIGH. MID-RANGE MODEL SOLUTIONS VARY REGARDING OVERALL PRECIPITATION PLACEMENT... BUT THE GENERAL TREND HAS HIGHER POPS OF 30-40 PERCENT ALONG AND NW OF A LINE FROM AVC-RIC-SBY AND LOWER POPS AROUND 20 PERCENT ACROSS NE NC/FAR SE VA. TEMPERATURES REMAIN WARM IN THE PERSISTENT RETURN FLOW WITH HIGHS ONCE AGAIN AROUND 90/MID-UPPER 80S IMMEDIATE COAST. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... SUMMER-LIKE PATTERN WILL TEND TO PREVAIL THROUGH THE MEDIUM RANGE PERIOD AS MID/UPPER LEVEL RIDGING CENTERED ALONG/OFF THE SE US COAST...GRADUALLY SHIFTS TO THE WSW AND BECOMES ANCHORED OVER THE DEEP SOUTH/GULF COAST REGION. TEMPERATURES WILL GENLY RUN ABOUT 5 F ABOVE AVG WITH HIGHS INTO THE UPPER 80S TO LOWER 90S AND LOWS IN THE UPPER 60S TO LOWER/MID 70S. A COUPLE OF WEAK MID LEVEL SHORTWAVES WILL BRING SOMEWHAT HIGHER POPS TO THE AREA FOR LABOR DAY...WILL CARRY 40% POPS THROUGHOUT...FOLLOWED BY POPS ONLY ~20% ON TUE IN BETWEEN THE DEPARTING WAVE AND A COLD FRONT APPROACHING FROM THE NW. TUE LIKELY THE HOTTEST DAY..WITH MOST LOCATIONS GETTING ABOVE 90 F AND PERHAPS INTO THE MID 90S OVER THE INTERIOR. ANOTHER ROUND OF SOMEWHAT HIGH POPS IS SLATED FOR TUE EVENING/TUE NIGHT AS THE COLD FRONT MOVES CLOSER TO THE LOCAL AREA AND HEIGHTS ALOFT DROP AS THE RIDGE BREAKS DOWN. BY LATE WED-THU...A GENERAL CONSENSUS OF THE GFS/ECMWF/WPC FORECAST DOES PUSH A SFC COLD FRONT SOUTH OF THE AREA WITH HIGH PRESSURE BUILDING ACRS THE NE CONUS. THIS SHOULD ALLOW SLIGHTLY COOLER/DRIER AIR TO MOVE INTO THE REGION...BUT THE FRONT DOES NOT LOOKS VERY STRONG SO HIGHS WILL STILL AVG IN THE MID-UPPER 80S ON THU. WILL FOCUS HIGHEST POPS WED-THU ACRS THE SOUTH (20-30%) WITH GENLY A DRY FORECAST ACRS THE ERN SHORE. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... COLD FRONT WILL STALL ALONG AND JUST SOUTH OF THE LOCAL AREA LATE TONIGHT AND FRIDAY, WITH GUIDANCE INDICATING POTENTIAL FOR SOME LOW STRATUS EARLY FRIDAY MORNING, AS LOW LEVEL MOISTURE GETS TRAPPED BENEATH THE NOCTURNAL INVERSION. HAVE GONE WITH MENTION FOR SCT-BKN CIGS ~ 4-5 KFT OVER SOUTHERN TERMINALS (PHF/ORF/ECG), WITH POTENTIAL FOR SOME LIGHT FOG/MIST AT/INVOF ECG FRIDAY MORNING. OUTLOOK...MAINLY DRY WEATHER WITH CONTINUED VFR CONDITIONS EXPECTED FRIDAY AND THROUGH MUCH OF THE UPCOMING HOLIDAY WEEKEND. SLIGHT TO LOW CHANCE POPS FOR AFTN/EVENING TSTMS SUNDAY EVENING INCREASE TO 30 TO 40 PERCENT MONDAY AHEAD OF THE NEXT FRONTAL PASSAGE. OTHERWISE, SOME POTENTIAL FOR FOG OR LOW CLOUDS WILL EXIST EACH DAY WITHIN A FEW HOURS OF SUNRISE. && .MARINE... CRISTOBAL NOW >500 NM ENE OF THE LOCAL AREA...WITH A WEAK SFC BOUNDARY HAVE PUSHED SOUTH OF THE WATERS. N/NE WINDS AVG AROUND 10 KT...WILL LIKELY INCREASE A BIT LATER TONIGHT AS MODEST PUSH OF COOLER AIR MOVES OVER THE WATERS WITH SFC HIGH PRESSURE MOVING ESE FROM MICHIGAN INTO THE NE AND NRN MID ATLC REGION. AS FOR HEADLINES...WILL MAINTAIN SCHS HEADLINE FOR COASTAL WATERS N OF PARRAMORE ISLAND THROUGH 10PM...WITH NO HEADLINES ELSEWHERE EVEN THOUGH THERE WILL BE SOME INCREASE IN WINDS OVER THE BAY OVERNIGHT INTO EARLY FRI. (MUCH LIKE WHAT OCCURRED EARLIER TODAY). N/NE WINDS WILL SLOWLY VEER TO THE E/NE IN THE AFTN AND AVG 10-15 KT ACRS THE LOWER BAY AND SOUTHERN COASTAL WATERS TO 5-10 KT FARTHER NORTH. SEAS WILL GENLY ONLY BE AROUND 3 FT...BUT WILL GENLY STILL HAVE A MODERATE RISK FOR RIP CURRENTS ALONG AREA BEACHES AS ENERGY FROM CRISTOBAL IS SLOW TO DIMINISH. WINDS THEN GRADUALLY VEER AND BECOME SE AND GRADUALLY INCREASE BY SATURDAY AFTN/EVENING. WINDS THEN BECOME S/SW SUNDAY. SEAS WILL GENERALLY RUN 3 FT OR LESS BUT MAY INCREASE TO 4 FT IN THE OUTER PORTION OF 20NM LATE SATURDAY AND SUNDAY...WITH A PERIOD OF 2-3 FT WAVES IN THE BAY SAT NIGHT. FAIRLY QUIET (OUTSIDE OF CONVECTION) INTO EARLY NEXT WEEK WITH SEAS 2-3 FT AND WAVES 1-2 FT OR LESS AS SFC HIGH REMAINS ANCHORED OFFSHORE AND NO SIGNIFICANT FRONTS MOVE INTO THE AREA UNTIL LATE TUE/WED. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH FRIDAY EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH FRIDAY EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH FRIDAY EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM EDT THIS EVENING FOR ANZ650-652. && $$ SYNOPSIS...ALB/BMD/JDM NEAR TERM...ALB/BMD SHORT TERM...BMD LONG TERM...LKB AVIATION...MAM/DAP MARINE...LKB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 PM EDT WED AUG 27 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 349 AM EDT WED AUG 27 2014 MUCH OF THE FOCUS OF THE SHORT TERM FORECAST IS WITH THE SHORTWAVE QUICKLY MOVING EAST-SOUTHEAST INTO THE UPPER GREAT LAKES REGION. THE AXIS OF THE SHORTWAVE IS LOCATED IN NORTHERN MINNESOTA AT 07Z...BUT THERE ARE TWO AREAS OF SHOWERS AHEAD OF THIS WAVE...ONE STRETCHING FROM ISLE ROYALE TO LITTLE FALLS MINNESOTA AND THE OTHER FROM WESTERN MARQUETTE COUNTY TO EAU CLAIRE WISCONSIN. EVEN THOUGH THE 00Z KMPX RAOB INDICATED DRY AIR BELOW THE CLOUDS BASE...RAIN HAS BEEN REACHING THE GROUND UNDER MOST OF THE RADAR RETURNS AND GENERALLY PRODUCING ANYWHERE FROM A TRACE TO 0.05IN OF RAIN AS IT HAS MOVED THROUGH MINNESOTA AND NORTHWEST WISCONSIN. EXPECT THESE SHOWERS TO CONTINUE TO THE EAST AS THE SHORTWAVE QUICKLY MOVES THROUGH THE WEST HALF OF UPPER MICHIGAN BY 12Z AND OUT OF THE ENTIRE AREA BY 15Z. THE 04Z/05Z HRRR RUNS HAVE HAD A DECENT HANDLE ON PRECIP AND WEIGHTED THE POP FORECAST TOWARDS THAT FOR THE FIRST 6HRS. THEREFORE...HAVE SHOWN SCATTERED/ISOLATED SHOWERS MOVING THROUGH THE CWA THIS MORNING AND QUICKLY COMING TO AN END FROM WEST TO EAST. BEHIND THE SHORTWAVE...DRY AIR ASSOCIATED WITH A HIGH CURRENTLY CENTERED IN MINNESOTA WILL QUICKLY MOVE OVER MUCH OF THE AREA AND LEAD TO ANOTHER COOL DAY ACROSS THE U.P. EXPECT SOME DIURNAL CLOUD DEVELOPMENT AFTER THE MID CLOUDS DEPART...AS A POCKET OF MOISTURE AROUND 850MB OR 4KFT SEEN OVER LAKE SUPERIOR THIS PAST EVENING AND KCMX OBS OVERNIGHT GRADUALLY SHIFTS SOUTHEAST AND DISSIPATES. WITH THE LIGHT WEST-NORTHWEST FLOW IN THE LOW LEVELS...EXPECT THE CLOUDS TO BE INLAND FROM LAKE SUPERIOR AND GENERALLY OVER CENTRAL/EASTERN UPPER MICHIGAN. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY OVER THE WEST THIRD (MID-UPPER 60S) AND SLIGHTLY COOLER OVER THE CENTRAL/EAST (65-71). HIGH PRESSURE WILL REMAIN IN PLACE TONIGHT AND PRODUCE MOSTLY CLEAR SKIES (JUST A FEW HIGH CLOUDS APPROACHING FROM THE SOUTHWEST AHEAD OF THE NEXT SHORTWAVE). THE MOSTLY CLEAR SKIES...LIGHT WINDS...AND PWATS AROUND 45 PERCENT OF NORMAL WILL LEAD TO A GOOD RADIATIONAL COOLING NIGHT. HAVE THE INTERIOR LOCATIONS FALLING INTO THE LOWER 40S TO UPPER 30S...WHICH IS A LITTLE COOLER THAN THE PREVIOUS FORECAST. WOULD NOT BE SURPRISED IF SOME OF THE TRADITIONAL COLD RAWS SITES REACH THE MIDDLE 30S AND DID DROP A FEW OF THEM TO THOSE VALUES (WHICH COULD LEAD TO SOME PATCHY FROST). WILL CONTINUE THE MENTION OF PATCHY RADIATIONAL/GROUND FOG FOR TONIGHT...BUT DON/T EXPECT IT TO BE TOO THICK DUE TO THE EXISTING DRY AIR. THE PLACES WHERE IT SHOULD BE THE THICKEST WOULD BE IN ANY LOW SPOTS OR NEAR LAKES (DUE TO THEIR WARMER WATER TEMPERATURES). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 519 AM EDT WED AUG 27 2014 THRU THE BEGINNING OF THE UPCOMING WEEKEND...A LOW AMPLITUDE PROGRESSIVE NRN STREAM FLOW REGIME WILL PREVAIL ACROSS SRN CANADA. A WEAKER SRN BRANCH FLOW ACROSS THE CONUS WILL CAUSE ISSUES WITH REGARD TO PCPN OVER THE UPPER LAKES...DEPENDING ON INTERACTION OF SHORTWAVES WITH THE MORE PROGRESSIVE FLOW TO THE N. RIGHT NOW...THE SRN BRANCH FEATURES A TROF AND WELL-DEFINED SHORTWAVE OVER THE SRN ROCKIES. EARLY NEXT WEEK...FLOW WILL AMPLIFY SOME AS A MORE SUBSTANTIAL TROF MOVES INTO THE NW CONUS AND THEN SHIFTS EASTWARD. OVERALL...THIS PATTERN WILL SUPPORT TEMPS GENERALLY AROUND NORMAL TO A BIT BLO OVER THE NEXT FEW DAYS. BRIEF WARMING WILL OCCUR EARLY NEXT WEEK AHEAD OF THE MORE SUBSTANTIAL TROF PROGRESSING E ACROSS THE NW AND NCNTRL CONUS. PCPN FCST IS QUITE UNCERTAIN. THERE IS THE POTENTIAL FOR AT LEAST A COUPLE OF ROUNDS OF PCPN THRU THE UPCOMING WEEKEND...DEPENDING ON EVOLUTION OF SRN BRANCH SHORTWAVES. ANOTHER PERIOD OF PCPN SHOULD OCCUR EARLY NEXT WEEK AS COLD FRONT SWEEPS ACROSS THE AREA IN ASSOCIATION WITH AFOREMENTIONED TROF MOVING ACROSS THE NW/NCNTRL CONUS. BEGINNING THU/FRI...ATTENTION TURNS TO SHORTWAVE LIFTING OUT OF THE SRN BRANCH TROF CURRENTLY OVER THE SRN ROCKIES. WITH NRN STREAM TROFS MOVING ACROSS THE CANADIAN ROCKIES AND QUEBEC/NEW ENGLAND... THERE WILL BE AN OPPORTUNITY FOR THE SRN BRANCH SHORTWAVE TO MAKE SOME NORTHWARD PROGRESS. MODELS HAVE OVERALL MOVED INTO BETTER AGREEMENT ON WAA/MOISTURE ADVECTION LIFTING N AND SPREADING PCPN INTO UPPER MI THU NIGHT/FRI. HOWEVER...THERE ARE STILL SOME DIFFERENCES AS THE GEM/ECMWF/NAM ARE MORE AGGRESSIVE SPREADING MAIN AREA OF PCPN MORE SQUARELY ACROSS THE FCST AREA. THE GFS IS FOCUSED MORE TO THE S AND E. GIVEN TRENDS AND GFS SOMEWHAT ON ITS OWN... RAISED POPS SOME FOR LATER THU NIGHT/FRI MORNING WITH LIKELY POPS FROM THE SCNTRL TO THE ERN FCST AREA. WILL NEED TO CONTINUE UPWARD TREND IF NEXT ROUND OF MODELS STAYS ON TRACK. INSTABILITY IS RATHER LIMITED. ONLY INCLUDED THUNDER SCNTRL AND E. AFTER SOME PATCHY FOG EARLY THU...SUNSHINE WILL GIVE WAY TO INCREASING HIGH CLOUDS. MIXING TO 850-800MB ON FCST SOUNDINGS SUGGEST HIGH TEMPS THU WILL BE MOSTLY IN THE LOW/MID 70S AWAY FROM LAKE COOLING. OVER THE WEEKEND...FCST HAS BECOME MORE UNCERTAIN AS THERE IS A TREND FOR THE MAIN ENERGY CURRENTLY IN THE SRN ROCKIES TROF TO LIFT FARTHER N. ASSOCIATED WEAK SFC WAVE IS FCST TO TRACK ACROSS SRN WI AND THRU NRN LWR MI. GIVEN TRENDS ALONG WITH DECENT AGREEMENT AMONG 00Z MEDIUM RANGE GUIDANCE...WILL LINGER CHC POPS OVER THE SE HALF OF THE FCST AREA FRI NIGHT...THEN SPREAD CHC POPS BACK N AND W SAT/SAT NIGHT. LOOKS LIKE SUN SHOULD DRY OUT WITH SHORTWAVE RIDGE ARRIVING BTWN DEPARTING SHORTWAVE AND AHEAD OF MORE SIGNIFICANT TROF DEVELOPING INTO THE NW CONUS. AS THE MORE SUBSTANTIAL TROF OVER THE NW CONUS SHIFTS EASTWARD EARLY NEXT WEEK...A COLD FRONT WILL SWEEP E ACROSS THE GREAT LAKES... BRINGING A DECENT POTENTIAL FOR SHRA/TSRA. FOR THIS FAR OUT IN THE MODEL RUNS...AGREEMENT IS GOOD ON TIMING FRONT. THE ECMWF HAS NOTABLY TRENDED FASTER TOWARD THE GFS WHICH IS TYPICALLY MORE PROGRESSIVE...AND THE GEM OFFERS SIMILAR TIMING. THESE LATEST RUNS SUGGEST FRONT CROSSING UPPER MI MON AFTN/NIGHT. SO IT LOOKS LIKE LABOR DAY MIGHT TURN WET WITH SHRA AND TSTMS SPREADING E ACROSS THE AREA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 133 PM EDT WED AUG 27 2014 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT ALL SITES...EXCEPT FOR SOME MVFR VIS AT SAW OVERNIGHT. SCATTERED TO BROKEN LOW-END VFR STRATOCUMULUS WILL DISSIPATE BY AROUND 00Z. HIGH PRESSURE WILL THEN BRING MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT...ALLOWING FOR PATCHY BR TO DEVELOP AT SAW. VIS MAY FLUCTUATE CONSIDERABLY DURING THE OVERNIGHT HOURS...BUT ANY BR OR FG SHOULD BE QUITE SHALLOW AND DISSIPATE SHORTLY AFTER SUNRISE THURSDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 349 AM EDT WED AUG 27 2014 HIGH PRESSURE MOVING THROUGH THE UPPER GREAT LAKES REGION TODAY AND THURSDAY WILL LEAD TO WINDS STAYING BELOW 15KTS. THIS HIGH WILL SHIFT EAST THURSDAY NIGHT...ALLOWING A COUPLE WEAK SURFACE TROUGHS TO MOVE THROUGH THE REGION. THE WEAK PRESSURE GRADIENT ASSOCIATED WITH THESE TROUGHS WILL KEEP WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...ROLFSON AVIATION...KLUBER MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
733 AM EDT WED AUG 27 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 349 AM EDT WED AUG 27 2014 MUCH OF THE FOCUS OF THE SHORT TERM FORECAST IS WITH THE SHORTWAVE QUICKLY MOVING EAST-SOUTHEAST INTO THE UPPER GREAT LAKES REGION. THE AXIS OF THE SHORTWAVE IS LOCATED IN NORTHERN MINNESOTA AT 07Z...BUT THERE ARE TWO AREAS OF SHOWERS AHEAD OF THIS WAVE...ONE STRETCHING FROM ISLE ROYALE TO LITTLE FALLS MINNESOTA AND THE OTHER FROM WESTERN MARQUETTE COUNTY TO EAU CLAIRE WISCONSIN. EVEN THOUGH THE 00Z KMPX RAOB INDICATED DRY AIR BELOW THE CLOUDS BASE...RAIN HAS BEEN REACHING THE GROUND UNDER MOST OF THE RADAR RETURNS AND GENERALLY PRODUCING ANYWHERE FROM A TRACE TO 0.05IN OF RAIN AS IT HAS MOVED THROUGH MINNESOTA AND NORTHWEST WISCONSIN. EXPECT THESE SHOWERS TO CONTINUE TO THE EAST AS THE SHORTWAVE QUICKLY MOVES THROUGH THE WEST HALF OF UPPER MICHIGAN BY 12Z AND OUT OF THE ENTIRE AREA BY 15Z. THE 04Z/05Z HRRR RUNS HAVE HAD A DECENT HANDLE ON PRECIP AND WEIGHTED THE POP FORECAST TOWARDS THAT FOR THE FIRST 6HRS. THEREFORE...HAVE SHOWN SCATTERED/ISOLATED SHOWERS MOVING THROUGH THE CWA THIS MORNING AND QUICKLY COMING TO AN END FROM WEST TO EAST. BEHIND THE SHORTWAVE...DRY AIR ASSOCIATED WITH A HIGH CURRENTLY CENTERED IN MINNESOTA WILL QUICKLY MOVE OVER MUCH OF THE AREA AND LEAD TO ANOTHER COOL DAY ACROSS THE U.P. EXPECT SOME DIURNAL CLOUD DEVELOPMENT AFTER THE MID CLOUDS DEPART...AS A POCKET OF MOISTURE AROUND 850MB OR 4KFT SEEN OVER LAKE SUPERIOR THIS PAST EVENING AND KCMX OBS OVERNIGHT GRADUALLY SHIFTS SOUTHEAST AND DISSIPATES. WITH THE LIGHT WEST-NORTHWEST FLOW IN THE LOW LEVELS...EXPECT THE CLOUDS TO BE INLAND FROM LAKE SUPERIOR AND GENERALLY OVER CENTRAL/EASTERN UPPER MICHIGAN. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY OVER THE WEST THIRD (MID-UPPER 60S) AND SLIGHTLY COOLER OVER THE CENTRAL/EAST (65-71). HIGH PRESSURE WILL REMAIN IN PLACE TONIGHT AND PRODUCE MOSTLY CLEAR SKIES (JUST A FEW HIGH CLOUDS APPROACHING FROM THE SOUTHWEST AHEAD OF THE NEXT SHORTWAVE). THE MOSTLY CLEAR SKIES...LIGHT WINDS...AND PWATS AROUND 45 PERCENT OF NORMAL WILL LEAD TO A GOOD RADIATIONAL COOLING NIGHT. HAVE THE INTERIOR LOCATIONS FALLING INTO THE LOWER 40S TO UPPER 30S...WHICH IS A LITTLE COOLER THAN THE PREVIOUS FORECAST. WOULD NOT BE SURPRISED IF SOME OF THE TRADITIONAL COLD RAWS SITES REACH THE MIDDLE 30S AND DID DROP A FEW OF THEM TO THOSE VALUES (WHICH COULD LEAD TO SOME PATCHY FROST). WILL CONTINUE THE MENTION OF PATCHY RADIATIONAL/GROUND FOG FOR TONIGHT...BUT DON/T EXPECT IT TO BE TOO THICK DUE TO THE EXISTING DRY AIR. THE PLACES WHERE IT SHOULD BE THE THICKEST WOULD BE IN ANY LOW SPOTS OR NEAR LAKES (DUE TO THEIR WARMER WATER TEMPERATURES). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 519 AM EDT WED AUG 27 2014 THRU THE BEGINNING OF THE UPCOMING WEEKEND...A LOW AMPLITUDE PROGRESSIVE NRN STREAM FLOW REGIME WILL PREVAIL ACROSS SRN CANADA. A WEAKER SRN BRANCH FLOW ACROSS THE CONUS WILL CAUSE ISSUES WITH REGARD TO PCPN OVER THE UPPER LAKES...DEPENDING ON INTERACTION OF SHORTWAVES WITH THE MORE PROGRESSIVE FLOW TO THE N. RIGHT NOW...THE SRN BRANCH FEATURES A TROF AND WELL-DEFINED SHORTWAVE OVER THE SRN ROCKIES. EARLY NEXT WEEK...FLOW WILL AMPLIFY SOME AS A MORE SUBSTANTIAL TROF MOVES INTO THE NW CONUS AND THEN SHIFTS EASTWARD. OVERALL...THIS PATTERN WILL SUPPORT TEMPS GENERALLY AROUND NORMAL TO A BIT BLO OVER THE NEXT FEW DAYS. BRIEF WARMING WILL OCCUR EARLY NEXT WEEK AHEAD OF THE MORE SUBSTANTIAL TROF PROGRESSING E ACROSS THE NW AND NCNTRL CONUS. PCPN FCST IS QUITE UNCERTAIN. THERE IS THE POTENTIAL FOR AT LEAST A COUPLE OF ROUNDS OF PCPN THRU THE UPCOMING WEEKEND...DEPENDING ON EVOLUTION OF SRN BRANCH SHORTWAVES. ANOTHER PERIOD OF PCPN SHOULD OCCUR EARLY NEXT WEEK AS COLD FRONT SWEEPS ACROSS THE AREA IN ASSOCIATION WITH AFOREMENTIONED TROF MOVING ACROSS THE NW/NCNTRL CONUS. BEGINNING THU/FRI...ATTENTION TURNS TO SHORTWAVE LIFTING OUT OF THE SRN BRANCH TROF CURRENTLY OVER THE SRN ROCKIES. WITH NRN STREAM TROFS MOVING ACROSS THE CANADIAN ROCKIES AND QUEBEC/NEW ENGLAND... THERE WILL BE AN OPPORTUNITY FOR THE SRN BRANCH SHORTWAVE TO MAKE SOME NORTHWARD PROGRESS. MODELS HAVE OVERALL MOVED INTO BETTER AGREEMENT ON WAA/MOISTURE ADVECTION LIFTING N AND SPREADING PCPN INTO UPPER MI THU NIGHT/FRI. HOWEVER...THERE ARE STILL SOME DIFFERENCES AS THE GEM/ECMWF/NAM ARE MORE AGGRESSIVE SPREADING MAIN AREA OF PCPN MORE SQUARELY ACROSS THE FCST AREA. THE GFS IS FOCUSED MORE TO THE S AND E. GIVEN TRENDS AND GFS SOMEWHAT ON ITS OWN... RAISED POPS SOME FOR LATER THU NIGHT/FRI MORNING WITH LIKELY POPS FROM THE SCNTRL TO THE ERN FCST AREA. WILL NEED TO CONTINUE UPWARD TREND IF NEXT ROUND OF MODELS STAYS ON TRACK. INSTABILITY IS RATHER LIMITED. ONLY INCLUDED THUNDER SCNTRL AND E. AFTER SOME PATCHY FOG EARLY THU...SUNSHINE WILL GIVE WAY TO INCREASING HIGH CLOUDS. MIXING TO 850-800MB ON FCST SOUNDINGS SUGGEST HIGH TEMPS THU WILL BE MOSTLY IN THE LOW/MID 70S AWAY FROM LAKE COOLING. OVER THE WEEKEND...FCST HAS BECOME MORE UNCERTAIN AS THERE IS A TREND FOR THE MAIN ENERGY CURRENTLY IN THE SRN ROCKIES TROF TO LIFT FARTHER N. ASSOCIATED WEAK SFC WAVE IS FCST TO TRACK ACROSS SRN WI AND THRU NRN LWR MI. GIVEN TRENDS ALONG WITH DECENT AGREEMENT AMONG 00Z MEDIUM RANGE GUIDANCE...WILL LINGER CHC POPS OVER THE SE HALF OF THE FCST AREA FRI NIGHT...THEN SPREAD CHC POPS BACK N AND W SAT/SAT NIGHT. LOOKS LIKE SUN SHOULD DRY OUT WITH SHORTWAVE RIDGE ARRIVING BTWN DEPARTING SHORTWAVE AND AHEAD OF MORE SIGNIFICANT TROF DEVELOPING INTO THE NW CONUS. AS THE MORE SUBSTANTIAL TROF OVER THE NW CONUS SHIFTS EASTWARD EARLY NEXT WEEK...A COLD FRONT WILL SWEEP E ACROSS THE GREAT LAKES... BRINGING A DECENT POTENTIAL FOR SHRA/TSRA. FOR THIS FAR OUT IN THE MODEL RUNS...AGREEMENT IS GOOD ON TIMING FRONT. THE ECMWF HAS NOTABLY TRENDED FASTER TOWARD THE GFS WHICH IS TYPICALLY MORE PROGRESSIVE...AND THE GEM OFFERS SIMILAR TIMING. THESE LATEST RUNS SUGGEST FRONT CROSSING UPPER MI MON AFTN/NIGHT. SO IT LOOKS LIKE LABOR DAY MIGHT TURN WET WITH SHRA AND TSTMS SPREADING E ACROSS THE AREA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 733 AM EDT WED AUG 27 2014 VFR CONDITIONS WILL PREVAIL AT ALL THREE SITES THROUGH THE TAF PERIOD. THE UPPER LEVEL DISTURBANCE THAT PRODUCE A FEW SHOWERS AT THE TAF SITES EARLY THIS MORNING IS QUICKLY DEPARTING THE REGION AND SHOULD BE EAST OF KSAW BY TAF VALID TIME. BEHIND THIS WAVE...THERE COULD BE SOME LINGERING DIURNAL CLOUDS...ESPECIALLY AT KSAW/KCMX DUE TO THEIR CLOSER PROXIMITY TO THE MOISTURE. TONIGHT WILL BE CLEAR...WHICH COULD LEAD TO VERY PATCHY GROUND FOG OVER CENTRAL UPPER MICHIGAN. DUE TO THE SHALLOW NATURE OF THIS FOG...HAVE LEFT KSAW VISIBILITIES AT VFR. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 349 AM EDT WED AUG 27 2014 HIGH PRESSURE MOVING THROUGH THE UPPER GREAT LAKES REGION TODAY AND THURSDAY WILL LEAD TO WINDS STAYING BELOW 15KTS. THIS HIGH WILL SHIFT EAST THURSDAY NIGHT...ALLOWING A COUPLE WEAK SURFACE TROUGHS TO MOVE THROUGH THE REGION. THE WEAK PRESSURE GRADIENT ASSOCIATED WITH THESE TROUGHS WILL KEEP WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...ROLFSON AVIATION...SRF MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
520 AM EDT WED AUG 27 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 349 AM EDT WED AUG 27 2014 MUCH OF THE FOCUS OF THE SHORT TERM FORECAST IS WITH THE SHORTWAVE QUICKLY MOVING EAST-SOUTHEAST INTO THE UPPER GREAT LAKES REGION. THE AXIS OF THE SHORTWAVE IS LOCATED IN NORTHERN MINNESOTA AT 07Z...BUT THERE ARE TWO AREAS OF SHOWERS AHEAD OF THIS WAVE...ONE STRETCHING FROM ISLE ROYALE TO LITTLE FALLS MINNESOTA AND THE OTHER FROM WESTERN MARQUETTE COUNTY TO EAU CLAIRE WISCONSIN. EVEN THOUGH THE 00Z KMPX RAOB INDICATED DRY AIR BELOW THE CLOUDS BASE...RAIN HAS BEEN REACHING THE GROUND UNDER MOST OF THE RADAR RETURNS AND GENERALLY PRODUCING ANYWHERE FROM A TRACE TO 0.05IN OF RAIN AS IT HAS MOVED THROUGH MINNESOTA AND NORTHWEST WISCONSIN. EXPECT THESE SHOWERS TO CONTINUE TO THE EAST AS THE SHORTWAVE QUICKLY MOVES THROUGH THE WEST HALF OF UPPER MICHIGAN BY 12Z AND OUT OF THE ENTIRE AREA BY 15Z. THE 04Z/05Z HRRR RUNS HAVE HAD A DECENT HANDLE ON PRECIP AND WEIGHTED THE POP FORECAST TOWARDS THAT FOR THE FIRST 6HRS. THEREFORE...HAVE SHOWN SCATTERED/ISOLATED SHOWERS MOVING THROUGH THE CWA THIS MORNING AND QUICKLY COMING TO AN END FROM WEST TO EAST. BEHIND THE SHORTWAVE...DRY AIR ASSOCIATED WITH A HIGH CURRENTLY CENTERED IN MINNESOTA WILL QUICKLY MOVE OVER MUCH OF THE AREA AND LEAD TO ANOTHER COOL DAY ACROSS THE U.P. EXPECT SOME DIURNAL CLOUD DEVELOPMENT AFTER THE MID CLOUDS DEPART...AS A POCKET OF MOISTURE AROUND 850MB OR 4KFT SEEN OVER LAKE SUPERIOR THIS PAST EVENING AND KCMX OBS OVERNIGHT GRADUALLY SHIFTS SOUTHEAST AND DISSIPATES. WITH THE LIGHT WEST-NORTHWEST FLOW IN THE LOW LEVELS...EXPECT THE CLOUDS TO BE INLAND FROM LAKE SUPERIOR AND GENERALLY OVER CENTRAL/EASTERN UPPER MICHIGAN. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY OVER THE WEST THIRD (MID-UPPER 60S) AND SLIGHTLY COOLER OVER THE CENTRAL/EAST (65-71). HIGH PRESSURE WILL REMAIN IN PLACE TONIGHT AND PRODUCE MOSTLY CLEAR SKIES (JUST A FEW HIGH CLOUDS APPROACHING FROM THE SOUTHWEST AHEAD OF THE NEXT SHORTWAVE). THE MOSTLY CLEAR SKIES...LIGHT WINDS...AND PWATS AROUND 45 PERCENT OF NORMAL WILL LEAD TO A GOOD RADIATIONAL COOLING NIGHT. HAVE THE INTERIOR LOCATIONS FALLING INTO THE LOWER 40S TO UPPER 30S...WHICH IS A LITTLE COOLER THAN THE PREVIOUS FORECAST. WOULD NOT BE SURPRISED IF SOME OF THE TRADITIONAL COLD RAWS SITES REACH THE MIDDLE 30S AND DID DROP A FEW OF THEM TO THOSE VALUES (WHICH COULD LEAD TO SOME PATCHY FROST). WILL CONTINUE THE MENTION OF PATCHY RADIATIONAL/GROUND FOG FOR TONIGHT...BUT DON/T EXPECT IT TO BE TOO THICK DUE TO THE EXISTING DRY AIR. THE PLACES WHERE IT SHOULD BE THE THICKEST WOULD BE IN ANY LOW SPOTS OR NEAR LAKES (DUE TO THEIR WARMER WATER TEMPERATURES). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 519 AM EDT WED AUG 27 2014 THRU THE BEGINNING OF THE UPCOMING WEEKEND...A LOW AMPLITUDE PROGRESSIVE NRN STREAM FLOW REGIME WILL PREVAIL ACROSS SRN CANADA. A WEAKER SRN BRANCH FLOW ACROSS THE CONUS WILL CAUSE ISSUES WITH REGARD TO PCPN OVER THE UPPER LAKES...DEPENDING ON INTERACTION OF SHORTWAVES WITH THE MORE PROGRESSIVE FLOW TO THE N. RIGHT NOW...THE SRN BRANCH FEATURES A TROF AND WELL-DEFINED SHORTWAVE OVER THE SRN ROCKIES. EARLY NEXT WEEK...FLOW WILL AMPLIFY SOME AS A MORE SUBSTANTIAL TROF MOVES INTO THE NW CONUS AND THEN SHIFTS EASTWARD. OVERALL...THIS PATTERN WILL SUPPORT TEMPS GENERALLY AROUND NORMAL TO A BIT BLO OVER THE NEXT FEW DAYS. BRIEF WARMING WILL OCCUR EARLY NEXT WEEK AHEAD OF THE MORE SUBSTANTIAL TROF PROGRESSING E ACROSS THE NW AND NCNTRL CONUS. PCPN FCST IS QUITE UNCERTAIN. THERE IS THE POTENTIAL FOR AT LEAST A COUPLE OF ROUNDS OF PCPN THRU THE UPCOMING WEEKEND...DEPENDING ON EVOLUTION OF SRN BRANCH SHORTWAVES. ANOTHER PERIOD OF PCPN SHOULD OCCUR EARLY NEXT WEEK AS COLD FRONT SWEEPS ACROSS THE AREA IN ASSOCIATION WITH AFOREMENTIONED TROF MOVING ACROSS THE NW/NCNTRL CONUS. BEGINNING THU/FRI...ATTENTION TURNS TO SHORTWAVE LIFTING OUT OF THE SRN BRANCH TROF CURRENTLY OVER THE SRN ROCKIES. WITH NRN STREAM TROFS MOVING ACROSS THE CANADIAN ROCKIES AND QUEBEC/NEW ENGLAND... THERE WILL BE AN OPPORTUNITY FOR THE SRN BRANCH SHORTWAVE TO MAKE SOME NORTHWARD PROGRESS. MODELS HAVE OVERALL MOVED INTO BETTER AGREEMENT ON WAA/MOISTURE ADVECTION LIFTING N AND SPREADING PCPN INTO UPPER MI THU NIGHT/FRI. HOWEVER...THERE ARE STILL SOME DIFFERENCES AS THE GEM/ECMWF/NAM ARE MORE AGGRESSIVE SPREADING MAIN AREA OF PCPN MORE SQUARELY ACROSS THE FCST AREA. THE GFS IS FOCUSED MORE TO THE S AND E. GIVEN TRENDS AND GFS SOMEWHAT ON ITS OWN... RAISED POPS SOME FOR LATER THU NIGHT/FRI MORNING WITH LIKELY POPS FROM THE SCNTRL TO THE ERN FCST AREA. WILL NEED TO CONTINUE UPWARD TREND IF NEXT ROUND OF MODELS STAYS ON TRACK. INSTABILITY IS RATHER LIMITED. ONLY INCLUDED THUNDER SCNTRL AND E. AFTER SOME PATCHY FOG EARLY THU...SUNSHINE WILL GIVE WAY TO INCREASING HIGH CLOUDS. MIXING TO 850-800MB ON FCST SOUNDINGS SUGGEST HIGH TEMPS THU WILL BE MOSTLY IN THE LOW/MID 70S AWAY FROM LAKE COOLING. OVER THE WEEKEND...FCST HAS BECOME MORE UNCERTAIN AS THERE IS A TREND FOR THE MAIN ENERGY CURRENTLY IN THE SRN ROCKIES TROF TO LIFT FARTHER N. ASSOCIATED WEAK SFC WAVE IS FCST TO TRACK ACROSS SRN WI AND THRU NRN LWR MI. GIVEN TRENDS ALONG WITH DECENT AGREEMENT AMONG 00Z MEDIUM RANGE GUIDANCE...WILL LINGER CHC POPS OVER THE SE HALF OF THE FCST AREA FRI NIGHT...THEN SPREAD CHC POPS BACK N AND W SAT/SAT NIGHT. LOOKS LIKE SUN SHOULD DRY OUT WITH SHORTWAVE RIDGE ARRIVING BTWN DEPARTING SHORTWAVE AND AHEAD OF MORE SIGNIFICANT TROF DEVELOPING INTO THE NW CONUS. AS THE MORE SUBSTANTIAL TROF OVER THE NW CONUS SHIFTS EASTWARD EARLY NEXT WEEK...A COLD FRONT WILL SWEEP E ACROSS THE GREAT LAKES... BRINGING A DECENT POTENTIAL FOR SHRA/TSRA. FOR THIS FAR OUT IN THE MODEL RUNS...AGREEMENT IS GOOD ON TIMING FRONT. THE ECMWF HAS NOTABLY TRENDED FASTER TOWARD THE GFS WHICH IS TYPICALLY MORE PROGRESSIVE...AND THE GEM OFFERS SIMILAR TIMING. THESE LATEST RUNS SUGGEST FRONT CROSSING UPPER MI MON AFTN/NIGHT. SO IT LOOKS LIKE LABOR DAY MIGHT TURN WET WITH SHRA AND TSTMS SPREADING E ACROSS THE AREA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 122 AM EDT WED AUG 27 2014 MID-LEVEL CLOUDS WILL INCREASE FOR A TIME OVERNIGHT UNTIL AROUND DAYBREAK ON WEDNESDAY AS A DISTURBANCE CROSSES THE REGION. ALTHOUGH A FEW SPRINKLES MAY BE POSSIBLE...ESPECIALLY AT IWD...LOW LEVELS WILL REMAIN DRY ENOUGH SO THAT VFR CONDITIONS WILL PREVAIL. THE MID CLOUDS ARE EXPECTED TO MOVE OUT BY LATE MORNING INTO THE AFTERNOON IN THE WAKE OF THE DISTURBANCE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 349 AM EDT WED AUG 27 2014 HIGH PRESSURE MOVING THROUGH THE UPPER GREAT LAKES REGION TODAY AND THURSDAY WILL LEAD TO WINDS STAYING BELOW 15KTS. THIS HIGH WILL SHIFT EAST THURSDAY NIGHT...ALLOWING A COUPLE WEAK SURFACE TROUGHS TO MOVE THROUGH THE REGION. THE WEAK PRESSURE GRADIENT ASSOCIATED WITH THESE TROUGHS WILL KEEP WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...ROLFSON AVIATION...JLB MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
350 AM EDT WED AUG 27 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 349 AM EDT WED AUG 27 2014 MUCH OF THE FOCUS OF THE SHORT TERM FORECAST IS WITH THE SHORTWAVE QUICKLY MOVING EAST-SOUTHEAST INTO THE UPPER GREAT LAKES REGION. THE AXIS OF THE SHORTWAVE IS LOCATED IN NORTHERN MINNESOTA AT 07Z...BUT THERE ARE TWO AREAS OF SHOWERS AHEAD OF THIS WAVE...ONE STRETCHING FROM ISLE ROYALE TO LITTLE FALLS MINNESOTA AND THE OTHER FROM WESTERN MARQUETTE COUNTY TO EAU CLAIRE WISCONSIN. EVEN THOUGH THE 00Z KMPX RAOB INDICATED DRY AIR BELOW THE CLOUDS BASE...RAIN HAS BEEN REACHING THE GROUND UNDER MOST OF THE RADAR RETURNS AND GENERALLY PRODUCING ANYWHERE FROM A TRACE TO 0.05IN OF RAIN AS IT HAS MOVED THROUGH MINNESOTA AND NORTHWEST WISCONSIN. EXPECT THESE SHOWERS TO CONTINUE TO THE EAST AS THE SHORTWAVE QUICKLY MOVES THROUGH THE WEST HALF OF UPPER MICHIGAN BY 12Z AND OUT OF THE ENTIRE AREA BY 15Z. THE 04Z/05Z HRRR RUNS HAVE HAD A DECENT HANDLE ON PRECIP AND WEIGHTED THE POP FORECAST TOWARDS THAT FOR THE FIRST 6HRS. THEREFORE...HAVE SHOWN SCATTERED/ISOLATED SHOWERS MOVING THROUGH THE CWA THIS MORNING AND QUICKLY COMING TO AN END FROM WEST TO EAST. BEHIND THE SHORTWAVE...DRY AIR ASSOCIATED WITH A HIGH CURRENTLY CENTERED IN MINNESOTA WILL QUICKLY MOVE OVER MUCH OF THE AREA AND LEAD TO ANOTHER COOL DAY ACROSS THE U.P. EXPECT SOME DIURNAL CLOUD DEVELOPMENT AFTER THE MID CLOUDS DEPART...AS A POCKET OF MOISTURE AROUND 850MB OR 4KFT SEEN OVER LAKE SUPERIOR THIS PAST EVENING AND KCMX OBS OVERNIGHT GRADUALLY SHIFTS SOUTHEAST AND DISSIPATES. WITH THE LIGHT WEST-NORTHWEST FLOW IN THE LOW LEVELS...EXPECT THE CLOUDS TO BE INLAND FROM LAKE SUPERIOR AND GENERALLY OVER CENTRAL/EASTERN UPPER MICHIGAN. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY OVER THE WEST THIRD (MID-UPPER 60S) AND SLIGHTLY COOLER OVER THE CENTRAL/EAST (65-71). HIGH PRESSURE WILL REMAIN IN PLACE TONIGHT AND PRODUCE MOSTLY CLEAR SKIES (JUST A FEW HIGH CLOUDS APPROACHING FROM THE SOUTHWEST AHEAD OF THE NEXT SHORTWAVE). THE MOSTLY CLEAR SKIES...LIGHT WINDS...AND PWATS AROUND 45 PERCENT OF NORMAL WILL LEAD TO A GOOD RADIATIONAL COOLING NIGHT. HAVE THE INTERIOR LOCATIONS FALLING INTO THE LOWER 40S TO UPPER 30S...WHICH IS A LITTLE COOLER THAN THE PREVIOUS FORECAST. WOULD NOT BE SURPRISED IF SOME OF THE TRADITIONAL COLD RAWS SITES REACH THE MIDDLE 30S AND DID DROP A FEW OF THEM TO THOSE VALUES (WHICH COULD LEAD TO SOME PATCHY FROST). WILL CONTINUE THE MENTION OF PATCHY RADIATIONAL/GROUND FOG FOR TONIGHT...BUT DON/T EXPECT IT TO BE TOO THICK DUE TO THE EXISTING DRY AIR. THE PLACES WHERE IT SHOULD BE THE THICKEST WOULD BE IN ANY LOW SPOTS OR NEAR LAKES (DUE TO THEIR WARMER WATER TEMPERATURES). .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 352 PM EDT TUE AUG 26 2014 AS HAS BEEN THE CASE THE LAST SEVERAL DAYS...FCST CONCERNS IN THE MIDDLE/LONGER TERM WL FOCUS ON THE INTERACTION BTWN A FAIRLY ZONAL NRN BRANCH FLOW OVER SRN CANADA/A WEAKER SRN BRANCH FLOW OVER THE CONUS AND POTENTIAL FOR PCPN ACRS UPR MI. THE BULK OF THE LATEST MODEL GUIDANCE HINTS THE SE CWA WL BE IMPACTED MOST BY WAVES REMAINING MAINLY IN THE SRN BRANCH. NEAR SEASONABLE TEMPS INTO THE WEEKEND WL GIVE WAY TO WARMER WX EARLY NEXT WEEK AND SOME SHOWERS/TS LATER ON LABOR DAY AS A STRONG COLD FNT APRCHS THE AREA. WED NGT...SFC HI PRES IN ADVANCE OF SHRTWV RDG WITHIN NRN BRANCH FLOW WL BRING MOCLR SKIES AND LGT WINDS. SOME HI CLDS MAY BEGIN TO FILTER INTO THE SW CWA LATE AT NGT AS THE SFC HI SHIFTS TO THE E AND A BIT OF A RETURN SLY FLOW BEGINS TO DVLP IN ADVANCE OF SHRTWV EMBEDDED IN WEAKER SRN BRANCH THAT WL BE SHIFTING THRU THE NCENTRAL PLAINS. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR E AND CENTRAL CLOSER TO THE CORE OF THE HI PRES/PWAT AS LO AS 0.50 INCH OR ABOUT 50 PCT OF NORMAL. PREVIOUS FCST TEMPS APPEAR ON TRACK. MAINTAINED MENTION OF PATCHY FOG IN THIS AREA. THU THRU SAT...NOT SURPRISINGLY...MODEL FCST DIFFERENCES BECOME MORE APRNT REGARDING THE POTENTIAL INTERACTION BTWN THE STRONGER NRN BRANCH FLOW IN SRN CANADA/WEAKER FLOW OVER THE CONUS AND HOW QUICKLY AND HOW FAR N PCPN WL SPREAD IN ADVANCE OF A DISTURBANCE RIPPLING THRU THE SRN BRANCH FM THE NCENTRAL PLAINS TOWARD THE UPR MIDWEST/ GREAT LKS AND WHEN/HOW QUICKLY ANY PCPN WOULD EXIT THE AREA. FOR INSTANCE...THE 00Z CNDN MODEL WAS MUCH FASTER AT BRINGING PCPN INTO THE WRN CWA ON THU...BUT THIS MODEL SHOWED MORE PHASING BTWN THE BRANCHES/A DEEPER SFC LO LIFTING NEWD THRU MN/SSW H85 WINDS UP TO 50 KTS AGGRESSIVELY RETURNING MSTR/HIER INSTABILITY INTO THE UPR LKS. THIS MODEL THEN SHOWED MORE RAPID DRYING/SUBSIDENCE ON SAT BEHIND THE STRONGER/MORE PHASED DISTURBANCE. GIVEN THE LACK OF MEANINGFUL INTERACTION APRNT ON THE SEPARATE FCST H5 FLOWS AND THE SHIFT OF THE 12Z CNDN MODEL TOWARD THE OTHER MORE SUPPRESSED GUIDANCE...WL TEND TOWARD A CONSENSUS OF THE 12Z GFS AND 00Z ECMWF THAT SHOW A RIBBON OF HIER QPF OVER MAINLY THE SE CWA ON THE SE EDGE OF FCST CONFLUENCE ZN IN THE H5 FLOW AND CLOSER TO MORE PERSISTENT SFC LO PRES TROF... WHERE THE FCST PWAT REMAINS AS HI AS 1.50-2.00 INCHES. ON SAT...A SHRTWV IN THE NRN BRANCH IS FCST TO SWING THRU NW ONTARIO...WITH ATTENDANT COLD FNT CROSSING THE UPR LKS. BUT SINCE THE BULK OF THE MSTR IS LIKELY TO REMAIN TO THE SE CLOSER TO SRN BRANCH DISTURBANCE TRACK/SFC LO PRES TROF...SUSPECT THE FROPA WL BE RELATIVELY DRY. HIER POPS WL REMAIN OVER THE SE CWA. EXTENDED...BEST CHC FOR A DRY DAY APPEARS TO BE ON SUN...WHEN SFC HI PRES IS FCST TO PASS THRU ONTARIO UNDER A SHRTWV RDG IN THE NRN BRANCH. BUT SOME OF THE EXTENDED MODELS SHOWED A SLOWER SRN BRANCH SHRTWV MOVING THRU LOWER MI BRINGING SOME PCPN INTO AT LEAST THE SE CWA. SO FCST WL SHOW SOME LO CHC POPS OVER MAINLY THAT AREA. ON LABOR DAY/TUE...STRENGTHENING SSW FLOW BTWN THE HI SHIFTING INTO QUEBEC AND A FAIRLY STRONG DISTURBANCE/ATTENDANT COLD FNT MOVING ACRS SRN CANADA WL BRING A RETURN OF WARMER...MOISTER AIR/GREATER SHOWER AND TS CHCS. WL RELY ON THE MODEL CONSENSUS FOR FCST PREPARATION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 122 AM EDT WED AUG 27 2014 MID-LEVEL CLOUDS WILL INCREASE FOR A TIME OVERNIGHT UNTIL AROUND DAYBREAK ON WEDNESDAY AS A DISTURBANCE CROSSES THE REGION. ALTHOUGH A FEW SPRINKLES MAY BE POSSIBLE...ESPECIALLY AT IWD...LOW LEVELS WILL REMAIN DRY ENOUGH SO THAT VFR CONDITIONS WILL PREVAIL. THE MID CLOUDS ARE EXPECTED TO MOVE OUT BY LATE MORNING INTO THE AFTERNOON IN THE WAKE OF THE DISTURBANCE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 349 AM EDT WED AUG 27 2014 HIGH PRESSURE MOVING THROUGH THE UPPER GREAT LAKES REGION TODAY AND THURSDAY WILL LEAD TO WINDS STAYING BELOW 15KTS. THIS HIGH WILL SHIFT EAST THURSDAY NIGHT...ALLOWING A COUPLE WEAK SURFACE TROUGHS TO MOVE THROUGH THE REGION. THE WEAK PRESSURE GRADIENT ASSOCIATED WITH THESE TROUGHS WILL KEEP WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...KC AVIATION...JLB MARINE...SRF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
244 AM CDT Wed Aug 27 2014 .SYNOPSIS: Issued at 237 AM CDT Wed Aug 27 2014 Front is slowly making progress into the CWA early this morning and is currently stretching from near Kansas City, Missouri to Quincy, Illinois. Some isolated thunderstorms continue to pop up here and there on outflow boundaries across eastern Missouri and west central Illinois, with a better defined cluster of convection now taking shape across far northwest Missouri. Temperatures remain mild with all locations still in the 70s this morning. CVKING && .SHORT TERM: (Through Tonight) Issued at 237 AM CDT Wed Aug 27 2014 Elevated convection will continue to develop across northern Missouri early this morning with scattered thunderstorms forecast through the lunch hour across the northern counties of the CWA. Front will make very slow progress south today. Temperatures will quickly rise into the 90s south of the front and due to pooled dewpoints in the lower to middle 70s, produce at least a few hours of heat indices above 100 degrees along and south of I-70. Although it won`t be as hot as the past few days - feel current heat headlines are warranted given potential for one more day of heat indices reaching 105 degrees this afternoon. The front will also serve as the focus for convective initiation with scattered thunderstorms expected along and south of I-70 this afternoon. As was the case yesterday, a few of the storms could produce some gusty winds to 50 mph and torrential downpours. Diurnal convection expected to dissipate quickly after sunset with the focus for more elevated development shifting back north of the boundary across the northern reaches of the CWA after midnight. CVKING .LONG TERM: (Thursday through Tuesday) Issued at 237 AM CDT Wed Aug 27 2014 Boundary will be slow to lift back north on Thursday and may become orientated more northwest to southeast across the CWA...paralleling the Mississippi River. Once again, afternoon convection will be possible in the vicinity of this front. The boundary should finally lift north as a warm front Thursday night with dry and seasonably warm weather expected on Friday ahead of the shortwave/cold front that approaches from the west. Have tried to focus likely POPs Friday night and Saturday with this next system as blended guidance seems to give too long of a period of POPs when compared to reality. So, after a wet and cooler beginning to the Labor Day Weekend, it appears chances of precipitation will decrease for Sunday and Monday (Labor Day), with temperatures beginning to inch back up above normal in the wake of this storm system. CVKING && .AVIATION: (For the 06z TAFs through 06z Wednesday Night) Issued at 1054 PM CDT Tue Aug 26 2014 Cluster of storms northeast of the St Louis metro area will likely slowly dissipate late tonight, although could not rule out an isolated storm along the outflow boundary moving southwestward through the St Louis metro. The surface wind will temporarily switch to a northeast direction and pick up behind the outflow boundary. A cold front was across northern MO, just south of UIN this evening. This front will sag slowly southward late tonight and Wednesday with scattered convection possible along and just north of this front. Latest HRRR model run keeps UIN dry late tonight, but there may be at least isolated showers/storms in the UIN area late tonight into Wednesday morning. Due to uncertainty in timing and coverage may keep the UIN taf dry for now. With mostly light surface winds, mainly just high level clouds, and high surface dew points there will likely be some fog late tonight/early Wednesday morning mainly in SUS and CPS. The surface wind will be mainly nely in UIN and COU Wednesday, and becoming nely Wednesday afternoon in the St Louis metro area after fropa. Specifics for KSTL: May need to include VCTS in the STL taf around 06-07z late tonight if storms develop along outflow boundary dropping southwestward through STL. The wind will also briefly switch to a nely direction and become gusty around 06z behind the outflow boundary. Should have scattered diurnal cumulus clouds late Wednesday morning and afternoon as the atmosphere becomes very unstable along the weakening cold front which will sag southward through central MO. Will likely be isolated to scattered thunderstorms Wednesday afternoon, but may leave out of the STL taf for now. The surface wind will become nely Wednesday afternoon as the front sags south of STL. GKS && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 94 77 92 77 / 40 20 40 20 Quincy 87 71 88 71 / 20 20 40 20 Columbia 92 72 92 72 / 20 20 20 10 Jefferson City 93 72 92 72 / 30 20 10 10 Salem 93 71 89 71 / 30 20 30 20 Farmington 95 71 91 71 / 40 20 20 10 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO- Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO- Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO- Washington MO. EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO. IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL- Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL- Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL- Randolph IL-St. Clair IL-Washington IL. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1120 PM CDT Tue Aug 26 2014 .SHORT TERM: (Through Late Tonight) Issued at 324 PM CDT Tue Aug 26 2014 A fairly well-defined convergence zone extends along an axis from Champaign through St. Louis towards Springfield this afternoon associated with an old convective boundary. SBCAPE is over 4000 j/kg with little CIN along this corridor, and scattered storms were noted along portions of the boundary. Short range HRRR and RAP guidance suggests some of this activity may linger past sunset and thus have included some low pops within the region. Otherwise the other threat of showers and thunderstorms tonight will shift northward along and north of the real east-west frontal boundary which will be drapped across northern KS and northern MO into central IL, mainly late tonight. Glass .LONG TERM: (Wednesday through Next Tuesday) Issued at 324 PM CDT Tue Aug 26 2014 The east-west frontal boundary will gradually sink southward throughout the day Wednesday settling into southern MO and southern IL by early evening. Very unstable conditions due to daytime heating and high dew points will persist and maintain a threat of scattered showers and thunderstorms will the front, and just to its north. Present indications are that overall the atmosphere will be slightly cooler in the low-mid levels. This cooling along with the front and attendant clouds/precipitation are expected to diminish the magnitude of the recent heat. However despite slightly cooler temperatures, the pooling of surface dew points in the 70s will continue to produce afternoon heat index values of 100-105 degrees along and south of a Columbia to Litchfield line. I have extended the heat advisories and warnings in this region, while the excessive heat appears to be over across northern MO and central IL where cooler conditions have also been noted today. The east-west front is expected to retreat back northward on Thursday as an upper trof migrates out of the Rockies and the associated surface low lifts northeastward. The highest pops will remain along and north of the retreating boundary, primarily northern sections of the CWA Thursday-Thursday night. Heat is a tough call on Thursday and the current forecast calls for highs in the upper 80s to lower 90s. There could potentially be some lingering pockets of afternoon HI values of 100+ but there is too much uncertainty to extend any heat headlines to this time period. The heat should definitely come to an end by the weekend. The models move the upper trof from the Plains on Friday into and through the MS Valley by late Sunday. A good chance of showers and thunderstorms will accompany this trof and the attendant frontal system, with cooler temperatures closer to normal for this time of year. Glass && .AVIATION: (For the 06z TAFs through 06z Wednesday Night) Issued at 1054 PM CDT Tue Aug 26 2014 Cluster of storms northeast of the St Louis metro area will likely slowly dissipate late tonight, although could not rule out an isolated storm along the outflow boundary moving southwestward through the St Louis metro. The surface wind will temporarily switch to a northeast direction and pick up behind the outflow boundary. A cold front was across northern MO, just south of UIN this evening. This front will sag slowly southward late tonight and Wednesday with scattered convection possible along and just north of this front. Latest HRRR model run keeps UIN dry late tonight, but there may be at least isolated showers/storms in the UIN area late tonight into Wednesday morning. Due to uncertainty in timing and coverage may keep the UIN taf dry for now. With mostly light surface winds, mainly just high level clouds, and high surface dew points there will likely be some fog late tonight/early Wednesday morning mainly in SUS and CPS. The surface wind will be mainly nely in UIN and COU Wednesday, and becoming nely Wednesday afternoon in the St Louis metro area after fropa. Specifics for KSTL: May need to include VCTS in the STL taf around 06-07z late tonight if storms develop along outflow boundary dropping southwestward through STL. The wind will also briefly switch to a nely direction and become gusty around 06z behind the outflow boundary. Should have scattered diurnal cumulus clouds late Wednesday morning and afternoon as the atmosphere becomes very unstable along the weakening cold front which will sag southward through central MO. Will likely be isolated to scattered thunderstorms Wednesday afternoon, but may leave out of the STL taf for now. The surface wind will become nely Wednesday afternoon as the front sags south of STL. GKS && .LSX WATCHES/WARNINGS/ADVISORIES: MO...HEAT ADVISORY until 8 PM CDT Wednesday FOR Audrain MO-Boone MO- Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO- Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO- Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO- Washington MO. EXCESSIVE HEAT WARNING until 8 PM CDT Wednesday FOR Jefferson MO- Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO. IL...EXCESSIVE HEAT WARNING until 8 PM CDT Wednesday FOR Bond IL- Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL- Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL- Randolph IL-St. Clair IL-Washington IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
644 PM CDT THU AUG 28 2014 .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 309 PM CDT THU AUG 28 2014 THE PRIMARY FORECAST CONCERN THROUGH TONIGHT WILL ONCE AGAIN CENTER AROUND THE CHANCE OF THUNDERSTORMS...LOCALLY HEAVY RAINFALL...AND POSSIBLE FLOODING. SHOWERS AND THUNDERSTORMS SHOULD BE LESS WIDESPREAD AND OVERALL LESS HEAVY THAN WHAT WE SAW LAST NIGHT. THE PRIMARY TRIGGERING MECHANISM CONTINUES TO BE AN UPPER LEVEL TROUGH THAT HAS VERY SLOWLY BEEN SLIDING EAST ACROSS NEBRASKA. THE 500 MB TROUGH AXIS WILL EVENTUALLY SLIDE EAST INTO OUR CWA BY DAWN. AS LONG AS WE ARE OUT AHEAD OF THIS TROUGH AXIS WE WILL SEE AT LEAST SOME CHANCE OF SHOWERS AND THUNDERSTORMS...WHICH WILL BE THE CASE THROUGH THE NIGHT. THE 18Z NAM AND A RUN OR TWO OF THE HRRR ARE NOW HINTING AT THE POSSIBILITY OF SOME ELEVATED THUNDERSTORMS FORMING WITHIN A FEW HOURS AFTER SUNSET AROUND HIGHWAY 281 OR A LITTLE EAST OF HIGHWAY 281. IF THESE STORMS FORM THEY WILL TRACK NORTHEAST AND COULD BE HEAVY RAIN PRODUCERS WITH AN OUTSIDE CHANCE OF A LOW END SEVERE HAIL OR WIND EVENT. INSTABILITY HAS BEEN RATHER LOW TODAY DUE TO THE EXTENSIVE CLOUD COVER...WHICH IS THE PRIMARY LIMITING FACTOR FOR SEVERE POTENTIAL. IN ADDITION...THE DEEP LAYER WIND SHEAR IS ONLY AROUND 30 KTS...WHICH IS WEAK TO MODEST AND CERTAINLY NOT OVERLY IMPRESSIVE FOR SEVERE POTENTIAL. THEREFORE...GIVEN A FAIRLY SIMILAR MOIST ENVIRONMENT TO LAST NIGHT BEING LOCATED OUT AHEAD OF THE UPPER TROUGH...WITH JUST A BIT LESS LIFT OUR PRIMARY CONCERN WILL REALLY CONTINUE TO BE HEAVY RAIN...BUT JUST LIKELY NOT AS WIDESPREAD AS THE OTHER NIGHT. THE GROUND IS VERY SATURATED ACROSS PRETTY MUCH OUR ENTIRE FORECAST AREA SO ANY HEAVY RAIN WILL RESULT IN RUNOFF AND POSSIBLE FLOODING. AM MOST CONCERNED FOR THE AREA ALONG AND EAST OF HIGHWAY 281 BASED ON THE LATEST 18Z NAM. OVERALL...THE PROBABILITY OF RAIN IS LOWER TONIGHT THAN LAST NIGHT GIVEN THAT THE COVERAGE AREA WILL BE LESS AND IT IS HARD TO PIN POINT EXACTLY WHERE THE THUNDERSTORMS WILL DEVELOP WITHIN THE MORE BROAD FAVORABLE ZONE. .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 309 PM CDT THU AUG 28 2014 FORECAST FOCUS IS ON THE CHANCES OF STORMS FRIDAY AND THEN CHANCES OF SEVERE STORMS ON SUNDAY. MODELS ARE IN GOOD AGREEMENT WITH MOVING AND TIMING OF MAJOR FEATURES AT LEAST THROUGH MONDAY. IN GENERAL THE ATMOSPHERE IS FORECAST TO MORPH FROM A CUTOFF LOW PATTERN BACK TO A MORE ZONAL FLOW...SO OUT OF A HEAVY RAIN PATTERN AND BACK INTO A SEVERE WEATHER TYPE REGIME. THE LOW PRESSURE AREA THAT HAD BEEN PARKED OVER THE CENTRAL ROCKIES THE LAST SEVERAL DAYS WILL EJECT EASTWARD ON FRIDAY AND LEAVE DRY WEATHER BEHIND. AS IT MOVES THROUGH THERE WILL BE A THREAT OF STORMS...BUT MAINLY OVER THE EASTERN THIRD OF THE AREA ON FRIDAY AFTERNOON AND EARLY EVENING. A RIDGE BUILDS OVER THE AREA ON SATURDAY BRINGING THE FIRST DRY AND WARM DAY IN QUITE A WHILE. LOW CHANCES OF STORMS ARE BACK IN THE FORECAST FOR SATURDAY NIGHT AND SUNDAY MORNING WITH A WEAK WAVE MOVING ACROSS THE AREA. HOWEVER...THE CHANCE OF STORMS FROM MID DAY SUNDAY INTO THE EVENING IS MORE IMPRESSIVE. A COLD FRONT AND FAIRLY STRONG MID LEVEL WAVE MOVE THROUGH DURING THAT TIME FRAME. MOST MODELS ARE IN AGREEMENT WITH THE THE TIMING AN STRENGTH OF THE SYSTEM. THE STRONG INSTABILITY AND GOOD SHEAR ARE MORE COMMON FOR MAY THAN AUGUST. SO THERE IS A THREAT OF DAMAGING WINDS AND LARGE HAIL WITH STORMS THAT DEVELOP. AS WITH ANY FORECAST OF CONVECTION SO MANY DAYS OUT THE MODELS WILL LIKELY CHANGE...SO WE WILL CONTINUE TO MONITOR IT. AS FOR THE WORK WEEK (MONDAY THROUGH THURSDAY)...OVERALL...MUCH DRIER THAN THIS LAST WEEK...BUT HARD TO RULE OUT A HIT AND MISS AFTERNOON AND EVENING STORM ESPECIALLY MONDAY...BUT THE MODELS ARE STILL WAFFLING WITH TIMING AND STRENGTH OF FEATURES SO WILL LEAVE DRY OR LOW PROBABILITIES UNTIL OUR CONFIDENCE RISES MORE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 640 PM CDT THU AUG 28 2014 QUITE AND ACTIVE WEATHER PATTERN IN THE CENTRAL PLAINS...BUT THE TIMING AND TRAJECTORY OF AN UPPER LEVEL SYSTEM SEEMS TO KEEP MOST OF THE ACTIVE WEATHER AT BAY. A WEAK SURFACE WILL PASS THROUGH THE AREA TOWARD FRIDAY AS THE UPPER LEVEL LOW SLOWLY MIGRATES EAST. AHEAD OF THE TROUGH...SEEMINGLY SOME RISK FOR RAIN...BUT MOST MODELS HAVE LIMITED COVERAGE IN THE KEAR/KGRI AREAS AND HAVE OPTED FOR DRY CONDITIONS AT THIS TIME. AS TROUGH APPROACHES A PERIOD LIGHT FOG MAY DEVELOP...PROBABLY CLOSER TO KGRI. EVENTUALLY WEST/NORTHWEST WINDS WILL SETTLE IN DURING THE DAY FRIDAY AND LEAD TO A GRADUAL CLEARING TREND. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...WESELY LONG TERM...EDDY AVIATION...MORITZ
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 PM EDT THU AUG 28 2014 .SYNOPSIS...A BACK DOOR COLD FRONT WILL TRACK SOUTHWARD FROM VIRGINIA INTO NORTH CAROLINA...THEN STALL OUT ACROSS THE REGION THROUGH FRIDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 PM THURSDAY... THE BACKDOOR SEGMENT OF THE COLD FRONT ORIENTED FROM NW TO SE ACROSS SOUTH-CENTRAL VA HAS MAINTAINED A BAND OF WEAK CONVECTION CENTERED NEAR FARMVILLE...VA FOR THE PAST SEVERAL HOURS. A PRECEDING...PRE- FRONTAL TROUGH DRAPED ACROSS CENTRAL NC HAS BEEN DEVOID OF ANY SUCH ACTIVITY...HOWEVER...DESPITE A RIBBON OF LOW-MID LEVEL MOISTURE CONVERGENCE AND WEAK AND SEEMINGLY UNINHIBITED ML INSTABILITY PER 00Z GSO AND MHX RAOB DATA. RECENT RUNS OF THE HRRR CONTINUE TO SUGGEST THE CONVECTION OVER SOUTH-CENTRAL VA WILL DRIFT SOUTH ACROSS THE NORTHEAST PIEDMONT AND NORTHERN COASTAL PLAIN...AND SUCH A SCENARIO SEEMS PLAUSIBLE GIVEN THE ENVIRONMENT DESCRIBED ABOVE. WILL CONSEQUENTLY MAINTAIN A SLIGHT-SMALL CHANCE OF A SHOWER OR STORM THERE OVERNIGHT. THE OTHER...AND HIGHER PROBABILITY...CONCERNS INCLUDE THE DEVELOPMENT OF AREAS OF FOG...OWING TO SAID LOW LEVEL MOISTURE POOLING ALONG THE PRE-FRONTAL TROUGH AXIS...AND LOW CLOUDS IN POST-FRONTAL NE LOW LEVEL FLOW ONCE THE FRONT SETTLES SOUTH INTO THE SANDHILLS AND SOUTHERN PIEDMONT BY EARLY FRI. IN FACT...A LOW OVERCAST IS APT TO DEVELOP GENERALLY ALONG AND NORTH OF HWY 64 VERY LATE TONIGHT THROUGH EARLY FRI. IF THE LOW CLOUDS INDEED MATERIALIZE...THEIR DISPERSION THROUGHOUT THE DAY FRI WOULD BE SLOW OWING A TRAPPING FRONTAL INVERSION BEHIND THE SOUTHWARD-SETTLING FRONT...WHICH COULD IMPACT HIGH TEMPS FRI. LOWS TONIGHT IN THE MID 60S TO LOW 70S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 200 PM THURSDAY... FRIDAY AND FRIDAY NIGHT: THE UPPER LEVEL RIDGE WILL AMPLIFY OVER THE MID-ATLANTIC ON FRIDAY. AT THE SURFACE...THE FRONT WILL BE STALLED IN THE VICINITY OF THE NC/VA BORDER DURING THE DAY BEFORE SLOWLY RETREATING TO THE NE OVERNIGHT. MUCH OF THE WEATHER WILL DEPEND ON THE LOCATION OF THE FRONTAL BOUNDARY THROUGHOUT THE DAY. THE LOWER TEMPS WILL BE ALONG AND NORTH OF THE FRONT...WITH HIGHER HIGHS ACROSS THE SOUTH. ANY CONVECTION THAT DEVELOPS WILL BE MAINLY ALONG AND SOUTH OF THE FRONT...BUT EXPECT COVERAGE TO BE ISOLATED AT BEST AND CONFIDENCE THAT IT WILL DEVELOP IS NOT TERRIBLY HIGH AT THIS TIME. CONTINUED MID LEVEL MOISTURE ADVECTION SHOULD RESULT IN CLOUDY CONDITIONS THROUGH A GOOD PART OF THE DAY. NORTHEASTERLY WINDS ALONG AND NORTH OF THE FRONT AND SOUTHWESTERLY SOUTH OF IT DURING THE DAY/EVENING SHOULD BECOME GENERALLY SOUTHEASTERLY ACROSS THE AREA OVERNIGHT. HIGHS EXPECTED TO RANGE FROM THE MID 80S NORTH TO LOW 90S SOUTH. LOWS IN THE UPPER 80S TO AROUND 70 DEGREES. -KC SATURDAY AND SATURDAY NIGHT: NORTH CAROLINA WILL STILL BE UNDER THE INFLUENCE OF A STRONG UPPER LEVEL RIDGE AND AN EXITING SURFACE HIGH PRESSURE TO THE NORTHEAST. THIS WILL KEEP WEATHER DRY AND SETTLED ON SATURDAY AND SATURDAY AFTERNOON. CONDITIONS WILL BE STABLE AND A SLIGHT DECREASE IN MOISTURE MAY HELP HIGH TEMPERATURES TO REACH THE LOWER 90S IN MOST LOCATIONS WITH UPPER 80S ACROSS THE NORTHERN COUNTIES. WINDS WILL BE OUT OF THE SOUTH AT AROUND 5 KTS GUSTING TO 10 KTS. THE HIGH WILL CONTINUE TO MOVE OFFSHORE SATURDAY NIGHT...ALLOWING MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO TO INCREASE AS A DISSIPATING LOW PRESSURE SYSTEM MOVES EASTWARD OUT OF THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THIS WILL SET THE STAGE FOR A MORE UNSETTLED PATTERN BEGINNING ON SUNDAY. LOWS SATURDAY NIGHT UPPER 60S TO LOWER 70S. -ELLIS && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 245 PM THURSDAY... SUNDAY THROUGH TUESDAY NIGHT: A MORE UNSETTLED PERIOD OF WEATHER WILL BEGIN ON SUNDAY WITH HIGH PRESSURE OFFSHORE SETTING UP A RETURN FLOW REGIME OVER CENTRAL NC THAT WILL TRANSPORT MOISTURE INTO THE AREA FROM THE GULF OF MEXICO AND SOUTHWESTERN ATLANTIC. AS PW VALUES CREEP UP OVER TWO INCHES THE CHANCES FOR CONVECTION WILL INCREASE...MAINLY DRIVEN BY INSTABILITY DURING THE DIURNALLY FAVORABLE TIMES AS SHEAR WILL REMAIN VERY WEAK. HIGH TEMPERATURES ARE EXPECTED TO RISE INTO THE LOWER 90S EACH DAY WITH LOWS IN THE LOWER 70S. WEDNESDAY AND THURSDAY: A MORE DEFINED FRONTAL SYSTEM WILL MOVE IN ON WEDNESDAY AS LOW PRESSURE MOVES THROUGH SOUTHERN QUEBEC AND A STRONG SURFACE HIGH BUILDS IN OVER THE GREAT LAKES AND EXTENDING DOWN INTO THE OHIO VALLEY. WITH THE LOW RAPIDLY MOVING OFF TO THE NORTHEAST...FORCING ALONG THE ATTENDANT COLD FRONT WILL REMAIN WEAK AS SHOWN BY SMALL STRAIGHT HODOGRAPHS THROUGH THE LOWEST 6KM ON MODEL FORECAST SOUNDINGS. TIMING OF THE FRONT AND ASSOCIATED PRECIPIATION IS IN QUESTION AT THIS TIME WITH MODELS HINTING AT A LATE WEDNESDAY/EARLY THURSDAY ARRIVAL AND THEN STALLING OUT SOMEWHERE OVER THE AREA FOR LATE WEEK. MOST CONVECTIVE ACTIVITY WILL REMAIN DIURNAL WITH THE SLIGHT CHANCES OVERNIGHT. TEMPERATURES SLIGHTLY COOLER WITH MORE ANTICIPATED CLOUD COVER AND SLIGHT AIRMASS CHANGE. UPPER 80S TO NEAR 90 FOR HIGHS WITH LOWS UPPER 60S TO NEAR 70 DEGREES. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AS OF 815 PM THURSDAY... VFR CONDITIONS CURRENTLY OBSERVED ACROSS CENTRAL NC WILL CONTINUE THROUGH 06Z. A COLD FRONT OVER VA WILL PUSH INTO NC FROM THE NORTH- NORTHEAST TONIGHT...WITH WINDS BECOMING NORTHEASTERLY BEHIND THE FRONT. LOW CLOUDS...AND POTENTIALLY A FEW ISOLATED SHOWERS... ARE EXPECTED TO DEVELOP ALONG AND IMMEDIATELY BEHIND THE FRONT. BASED ON A CONSENSUS OF MOST MODEL GUIDANCE...IFR CEILINGS ARE MOST LIKELY FROM JUST EAST OF KGSO/KINT TO KRDU AND KRWI AFTER 09Z. KFAY SHOULD REMAIN TO THE SOUTH OF THE FRONT AND CLEAR OF ANY SUB-VFR CEILINGS. LOW-CLOUDS WILL LIFT THROUGH MID-MORNING FRIDAY...THOUGH WITH AN EAST-NORTHEASTERLY LOW-LEVEL WIND...CEILINGS MAY REMAIN IN THE 2000- 3000FT RANGE FOR A GOOD PORTION OF THE DAY. ISOLATED TO WIDELY SCATTERED SHOWERS/STORMS WILL BE POSSIBLY FRIDAY AFTERNOON...MAINLY NEAR THE FRONT AS IT BEGINS TO LIFT BACK TO THE NORTH. LOOKING AHEAD: CONFIDENCE REMAINS BELOW NORMAL IN THIS PERIOD. EXPECT THE FRONT TO SLOWLY LIFT NNE AWAY FROM THE REGION FRIDAY NIGHT...WITH AN INCREASE IN SOUTHERLY RETURN FLOW INTO THE REGION... INCREASING LOW TO MID LEVEL MOISTURE THROUGH THE WEEKEND. THIS WILL YIELD INCREASED CHANCES FOR LOW CEILINGS IN THE PRE-DAWN HOURS THROUGH EARLY NEXT WEEK. FOR NOW EXPECT SATURDAY TO BE DRY...WITH INCREASING CHANCES FOR CONVECTION...MAINLY IN THE AFT/EVE...SUNDAY NIGHT THROUGH TUESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...MWS SHORT TERM...KC/ELLIS LONG TERM...ELLIS AVIATION...KC/BLS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
934 PM CDT THU AUG 28 2014 .UPDATE... ISSUED AT 934 PM CDT THU AUG 28 2014 NO CHANGES PLANNED FOR THIS UPDATE. UPDATE ISSUED AT 648 PM CDT THU AUG 28 2014 SATELLITE AND OBSERVATIONS SHOW CLOUD COVER PERSISTING OVER THE AREA. HRRR AND RUC SHOWING A DELAY IN MOVING CLOUDS OUT OF THE DVL BASIN SO ADJUSTED SKY GRIDS FOR THIS UPDATE. OTHERWISE...REST OF FORECAST LOOKS GOOD. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 250 PM CDT THU AUG 28 2014 THE MAIN CHALLENGE WILL BE PRECIP CHANCES. MODELS ARE IN GOOD OVERALL AGREEMENT WITH NO REAL PREFERENCE TODAY. FOR THIS EVENING AND OVERNIGHT...EXPECT SOME SHOWERS AND PERHAPS A RUMBLE OF THUNDER THIS EVENING IN ALL BUT THE FAR NW. THE BEST CHANCE FOR SHOWERS OVERNIGHT WILL BE ALONG AND SOUTHEAST OF A WAHPETON TO BAUDETTE LINE...WHERE DEEPER MOISTURE AND THE BEST LIFT WILL BE. HAVE LINGERED POPS A BIT LONGER IN THE EAST THROUGH MOST OF THE OVERNIGHT. ON FRIDAY...A COOL FRONT WILL MOVE FROM NW TO SE. THERE SHOULD BE A BAND OF SHOWERS AND STORMS ALONG AND BEHIND THE COLD FRONT...WITH THE BEST CHANCE FOR MEASURABLE PRECIP IN THE NORTH DURING THE MORNING...THEN IN THE SOUTH AND EAST DURING THE AFTERNOON. THERE WILL BE MLCAPES OVER 1500 J/KG...SO A FEW STRONGER STORMS ARE POSSIBLE DURING THE AFTERNOON. DEEP LAYERED SHEAR WILL BE WEAK THOUGH...LESS THAN 20 KT...SO EXPECT PULSE TYPE STORMS WITH PERHAPS SOME SMALL HAIL AND/OR BRIEF WIND GUSTS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 250 PM CDT THU AUG 28 2014 FOR SATURDAY...IT SHOULD BE A DRY AND SEASONABLE DAY WITH HIGH PRESSURE IN CONTROL. FOR SAT NIGHT...A FAIRLY CLASSIC ELEVATED CONVECTIVE EVENT IS POSSIBLE. A LLJ WILL INCREASE TO AROUND 50 KT INTO CENTRAL ND AFTER 00Z SUN...ALONG WITH SHOWALTERS FALLING TO AROUND -4C SAT NIGHT WITH 40KT OF EFFECTIVE SHEAR. THIS SHOULD LEAD TO AN ELEVATED MCS MOVING FROM SW TO NE SAT NIGHT INTO SUNDAY MORNING. A FEW STORMS COULD BE STRONG TO SEVERE WITH LARGE HAIL THE MAIN THREAT. ON SUNDAY...THE SEVERE POTENTIAL WILL INCREASE DURING THE AFTERNOON IN THE EAST AND SOUTH. THERE WILL BE AMPLE DEEP LAYERED SHEAR AND INSTABILITY...AND THE POTENTIAL FOR FAIRLY WIDESPREAD SHOWERS AND STORMS. SPC HAS OUTLOOKED THE EASTERN AREAS IN A DAY4 OUTLOOK...SO WE WILL HAVE TO MONITOR SUNDAY AFTERNOON FOR SEVERE POTENTIAL DEPENDING ON THE EXACT LOCATION OF THE FRONT AND WHICH AREAS RECEIVE INSOLATION DURING THE AFTERNOON. FOR SUN NIGHT THROUGH THU...MODELS IN SIMILAR AGREEMENT EARLY IN THE PERIOD WITH ZONAL UPPER AIR PATTERN AND A FRONT EXITING THE REGION...WITH MOST ASSOCIATED CONVECTION EAST OF THE AREA BY SUN NIGHT. MAIN DIFFERENCE IS DEPTH OF UPPER LOW OVER WRN ONTARIO...WITH GFS SHOWING A DEEPER LOW THAN ECMWF. CONSALL YIELDING CHANCE POPS BACK INTO THE VALLEY WITH THIS EXITING SYSTEM. WITH 12Z MODEL RUNS FASTER THAN THIS AND NO COORD ISSUES TO MY WEST...WILL LOWER POPS IN THE VALLEY TO 20S OR DRY. MON THROUGH WED THEN GENERALLY DRY...WITH A FEW MINOR SHORT WAVES YIELDING SOME LOW END POPS...AND SEASONAL TEMPS BEFORE NEXT SYSTEM WORKS ITS WAY ACROSS SRN CANADA AND BRINGS A CHANCE FOR TSTMS ACROSS THE NORTHERN PORTION OF THE CWA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 648 PM CDT THU AUG 28 2014 EXPECT MOSTLY -SHRA TO CONTINUE ACROSS THE SRN VALLEY WITH SPOTTY SHOWERS FARTHER NORTH. CIGS CONTINUE TO BE A CHALLENGE AS THEY BOB BACK AND FORTH BETWEEN VFR/MVFR INITIALLY...BUT EXPECT CLOUDS TO FILL BACK IN OVERNIGHT DROPPING CIGS INTO MVFR/IFR TERRITORY. AREAS OF FOG CAN BE EXPECTED BUT NOT EXPECTED TO DROP BELOW VFR AT THE TAF SITES ATTM. A SFC TROUGH WILL PUSH THROUGH THE AREA AND SWITCH WINDS TO THE SW...THEN NW NEAR END OF TAF PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...HOPKINS SHORT TERM...DK LONG TERM...DK/SPEICHER AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
648 PM CDT THU AUG 28 2014 .UPDATE... ISSUED AT 648 PM CDT THU AUG 28 2014 SATELLITE AND OBSERVATIONS SHOW CLOUD COVER PERSISTING OVER THE AREA. HRRR AND RUC SHOWING A DELAY IN MOVING CLOUDS OUT OF THE DVL BASIN SO ADJUSTED SKY GRIDS FOR THIS UPDATE. OTHERWISE...REST OF FORECAST LOOKS GOOD. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 250 PM CDT THU AUG 28 2014 THE MAIN CHALLENGE WILL BE PRECIP CHANCES. MODELS ARE IN GOOD OVERALL AGREEMENT WITH NO REAL PREFERENCE TODAY. FOR THIS EVENING AND OVERNIGHT...EXPECT SOME SHOWERS AND PERHAPS A RUMBLE OF THUNDER THIS EVENING IN ALL BUT THE FAR NW. THE BEST CHANCE FOR SHOWERS OVERNIGHT WILL BE ALONG AND SOUTHEAST OF A WAHPETON TO BAUDETTE LINE...WHERE DEEPER MOISTURE AND THE BEST LIFT WILL BE. HAVE LINGERED POPS A BIT LONGER IN THE EAST THROUGH MOST OF THE OVERNIGHT. ON FRIDAY...A COOL FRONT WILL MOVE FROM NW TO SE. THERE SHOULD BE A BAND OF SHOWERS AND STORMS ALONG AND BEHIND THE COLD FRONT...WITH THE BEST CHANCE FOR MEASURABLE PRECIP IN THE NORTH DURING THE MORNING...THEN IN THE SOUTH AND EAST DURING THE AFTERNOON. THERE WILL BE MLCAPES OVER 1500 J/KG...SO A FEW STRONGER STORMS ARE POSSIBLE DURING THE AFTERNOON. DEEP LAYERED SHEAR WILL BE WEAK THOUGH...LESS THAN 20 KT...SO EXPECT PULSE TYPE STORMS WITH PERHAPS SOME SMALL HAIL AND/OR BRIEF WIND GUSTS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 250 PM CDT THU AUG 28 2014 FOR SATURDAY...IT SHOULD BE A DRY AND SEASONABLE DAY WITH HIGH PRESSURE IN CONTROL. FOR SAT NIGHT...A FAIRLY CLASSIC ELEVATED CONVECTIVE EVENT IS POSSIBLE. A LLJ WILL INCREASE TO AROUND 50 KT INTO CENTRAL ND AFTER 00Z SUN...ALONG WITH SHOWALTERS FALLING TO AROUND -4C SAT NIGHT WITH 40KT OF EFFECTIVE SHEAR. THIS SHOULD LEAD TO AN ELEVATED MCS MOVING FROM SW TO NE SAT NIGHT INTO SUNDAY MORNING. A FEW STORMS COULD BE STRONG TO SEVERE WITH LARGE HAIL THE MAIN THREAT. ON SUNDAY...THE SEVERE POTENTIAL WILL INCREASE DURING THE AFTERNOON IN THE EAST AND SOUTH. THERE WILL BE AMPLE DEEP LAYERED SHEAR AND INSTABILITY...AND THE POTENTIAL FOR FAIRLY WIDESPREAD SHOWERS AND STORMS. SPC HAS OUTLOOKED THE EASTERN AREAS IN A DAY4 OUTLOOK...SO WE WILL HAVE TO MONITOR SUNDAY AFTERNOON FOR SEVERE POTENTIAL DEPENDING ON THE EXACT LOCATION OF THE FRONT AND WHICH AREAS RECEIVE INSOLATION DURING THE AFTERNOON. FOR SUN NIGHT THROUGH THU...MODELS IN SIMILAR AGREEMENT EARLY IN THE PERIOD WITH ZONAL UPPER AIR PATTERN AND A FRONT EXITING THE REGION...WITH MOST ASSOCIATED CONVECTION EAST OF THE AREA BY SUN NIGHT. MAIN DIFFERENCE IS DEPTH OF UPPER LOW OVER WRN ONTARIO...WITH GFS SHOWING A DEEPER LOW THAN ECMWF. CONSALL YIELDING CHANCE POPS BACK INTO THE VALLEY WITH THIS EXITING SYSTEM. WITH 12Z MODEL RUNS FASTER THAN THIS AND NO COORD ISSUES TO MY WEST...WILL LOWER POPS IN THE VALLEY TO 20S OR DRY. MON THROUGH WED THEN GENERALLY DRY...WITH A FEW MINOR SHORT WAVES YIELDING SOME LOW END POPS...AND SEASONAL TEMPS BEFORE NEXT SYSTEM WORKS ITS WAY ACROSS SRN CANADA AND BRINGS A CHANCE FOR TSTMS ACROSS THE NORTHERN PORTION OF THE CWA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 648 PM CDT THU AUG 28 2014 EXPECT MOSTLY -SHRA TO CONTINUE ACROSS THE SRN VALLEY WITH SPOTTY SHOWERS FARTHER NORTH. CIGS CONTINUE TO BE A CHALLENGE AS THEY BOB BACK AND FORTH BETWEEN VFR/MVFR INITIALLY...BUT EXPECT CLOUDS TO FILL BACK IN OVERNIGHT DROPPING CIGS INTO MVFR/IFR TERRITORY. AREAS OF FOG CAN BE EXPECTED BUT NOT EXPECTED TO DROP BELOW VFR AT THE TAF SITES ATTM. A SFC TROUGH WILL PUSH THROUGH THE AREA AND SWITCH WINDS TO THE SW...THEN NW NEAR END OF TAF PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...HOPKINS SHORT TERM...DK LONG TERM...DK/SPEICHER AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1257 PM CDT WED AUG 27 2014 .UPDATE... ISSUED AT 1258 PM CDT WED AUG 27 2014 HIGH PRESSURE OVER THE AREA WILL MOVE EAST TODAY. MAINLY CLEAR SKIES NORTHWEST WITH CU DEVELOPING SOUTH AND EAST. SHORT RANGE MODELS CONTINUE TO BRING SOME LIGHT RETURNS INTO THE SOUTH CENTRAL THIS AFTERNOON. ADDED SOME VERY SMALL POPS...WHICH WILL KEEP THE MENTION OF SHOWERS OUT OF THE WORDED FORECAST. LATEST 12 UTC NAM AND 15 UTC RAP SHOW ONLY A SHALLOW LAYER OF MOISTURE AROUND 3-5K FEET. MADE SOME MINOR CHANGES TO SKY COVER AND TEMPERATURES. UPDATE ISSUED AT 950 AM CDT WED AUG 27 2014 LATEST SATELLITE SHOWS QUITE A BIT OF FOG REMAINING OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA. HOWEVER...LOOKS LIKE IT IS DISSIPATING QUICKLY THUS WILL LIKELY DROP THE ADVISORY AFTER TAKING A LOOK AT THE 10 AM OBSERVATIONS. OTHERWISE NO SIGNIFICANT ISSUES TO THE GOING FORECAST. WILL UPDATE TEXT PRODUCTS WILL BE SENT WITH THE EXPIRATION/CANCELLATION OF THE DENSE FOG ADVISORY. UPDATE ISSUED AT 623 AM CDT WED AUG 27 2014 REFINED THE FOG AREAS TO REFLECT FOG OVER MOST OF THE WEST AND CENTRAL THIS MORNING. LEFT THE ADVISORY AREA IN PLACE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 431 AM CDT WED AUG 27 2014 FOR THE NEAR TERM/EARLY THIS MORNING...THE CURRENT FOG/STRATUS IMAGERY LOOP IN COMBINATION WITH SURFACE OBSERVATIONS SHOWS DENSE FOG EXPANDING OVER MOST OF CENTRAL NORTH DAKOTA. BASED ON CURRENT VISIBILITY TRENDS AND LATEST HRRR VISIBILITY FORECAST...HAVE ISSUED A DENSE FOG ADVISORY FOR MOST OF CENTRAL NORTH DAKOTA THROUGH LATE WEDNESDAY MORNING. OTHERWISE...A CLEAR SKY DOMINATES WEST AND NORTH WITH THE LATEST WATER VAPOR IMAGERY SHOWING SUBSIDENCE BEHIND A NORTHERN STREAM SHORTWAVE NOW INTO MINNESOTA. SPLIT FLOW CONTINUES WITH THE SOUTHERN BRANCH EXTENDING FROM THE GREAT BASIN INTO SOUTH DAKOTA. AN UPPER LOW/TROUGH WAS SEEN OVER WESTERN NEVADA EARLY THIS MORNING. EXPECTING PLENTY OF SUNSHINE TODAY WITH TEMPERATURES WARMING INTO THE 70S...AND LOWER 80S IN THE FAR WEST. ALL MODEL GUIDANCE...WITH THE EXCEPTION OF THE GFS...ARE IN AGREEMENT THAT THE SOUTHERN BRANCH MAKES A RETURN INTO SOUTHERN NORTH DAKOTA WEDNESDAY NIGHT. AS THE AFOREMENTIONED GREAT BASIN LOW/TROUGH SHIFTS EAST...A SURFACE LOW WILL TAKE SHAPE OVER NEBRASKA AND SOUTH DAKOTA LATER TODAY INTO TONIGHT. LATEST TRENDS INDICATE THE NORTHERN FRINGE OF PRECIPITATION WILL REACH THE JAMES RIVER VALLEY BETWEEN 06Z AND 12Z THURSDAY. AFTER COLLABORATING WITH ABERDEEN AND GRAND FORKS...HAVE INTRODUCED A SLIGHT CHANCE MENTION FOR SHOWERS AND WILL LET SUBSEQUENT SHIFTS LOOK AT THE LATEST DATA TO FINE TUNE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 431 AM CDT WED AUG 27 2014 DURING THIS PERIOD THERE WILL BE SEVERAL COLD FRONTAL PASSAGES THAT WILL BRING SOME ACTIVE WEATHER TO THE REGION OVER THE LABOR DAY WEEKEND. FIRST...THE REMNANTS OF AN UPPER LEVEL LOW WILL TRACK SOUTH OF THE STATE THURSDAY. WHILE THIS FEATURE WILL IMPACT THE AREAS SOUTH OF THE STATE WITH SEVERAL LARGE MCS TYPE CONVECTIVE SYSTEMS...THERE WILL BE SOME RESIDUAL MOISTURE PULLED INTO THE STATE...MAINLY ACROSS THE JAMES RIVER VALLEY THURSDAY MORNING. BUT THERE WILL LIKELY BE MORE CLOUDS THROUGH THE DAY THURSDAY THAN PREVIOUSLY THOUGHT ACROSS A LARGE PORTION OF SOUTHERN AND EASTERN NORTH DAKOTA. AFTER THIS A COLD FRONT WILL ENTER THE NORTHWEST SUPPORTED BY A RATHER WEAK LEADING SHORTWAVE TROUGH AHEAD OF A MORE SIGNIFICANT SHORTWAVE STILL LINGERING ACROSS THE NORTHWEST US FRIDAY. OVERALL...HAVE DOWN PLAYED THE POPS THURSDAY NIGHT AND FRIDAY...WAITING INSTEAD FOR THE MORE SIGNIFICANT SHORTWAVE DUE IN SATURDAY NIGHT AND SUNDAY. WITH THIS NEXT SYSTEM WILL SEE MORE SIGNIFICANT PRECIPITATION WITH STRONGER WARM/COLD FRONTAL PASSAGES. SO THE HOLIDAY WEEKEND SHOULD BE A BIT SOGGY SATURDAY NIGHT WITH SCATTERED SHOWERS ON SUNDAY. COOL CYCLONIC FLOW ALOFT SHOULD MAINTAIN SLIGHT THREAT FOR THUNDERSTORMS MONDAY AND TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1258 PM CDT WED AUG 27 2014 SKIES INITIALLY CLEAR AT 17 UTC...BUT CU IS FILLING IN QUICKLY ACROSS THE SOUTH CENTRAL AND EAST. KDIK...KISN AND KMOT SHOULD BE VFR THIS AFTERNOON. KBIS-KJMS MAINLY VFR BUT A BRIEF PERIOD OF MVFR CEILINGS POSSIBLE BEFORE CU FIELD LIFTS ABOVE 3K FEET. THEN LOW VFR CEILING LATE AFTERNOON AND TONIGHT. SYSTEM BRUSHES THE SOUTHEAST TONIGHT AND ADDED A VCSH AT KJMS AND KEPT LOW VFR CEILINGS AT KBIS AND KJMS. LEFT KDIK-KISN-KMOT VFR FOR NOW WITH A MENTION OF VCFG AROUND 10-14 UTC THURSDAY. WILL NEED TO MONITOR FOR HITTING FOG HARDER WITH LATER SHIFTS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...KS LONG TERM...WAA AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
950 AM CDT WED AUG 27 2014 .UPDATE... ISSUED AT 950 AM CDT WED AUG 27 2014 LATEST SATELLITE SHOWS QUITE A BIT OF FOG REMAINING OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA. HOWEVER...LOOKS LIKE IT IS DISSIPATING QUICKLY THUS WILL LIKELY DROP THE ADVISORY AFTER TAKING A LOOK AT THE 10 AM OBSERVATIONS. OTHERWISE NO SIGNIFICANT ISSUES TO THE GOING FORECAST. WILL UPDATE TEXT PRODUCTS WILL BE SENT WITH THE EXPIRATION/CANCELLATION OF THE DENSE FOG ADVISORY. UPDATE ISSUED AT 623 AM CDT WED AUG 27 2014 REFINED THE FOG AREAS TO REFLECT FOG OVER MOST OF THE WEST AND CENTRAL THIS MORNING. LEFT THE ADVISORY AREA IN PLACE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 431 AM CDT WED AUG 27 2014 FOR THE NEAR TERM/EARLY THIS MORNING...THE CURRENT FOG/STRATUS IMAGERY LOOP IN COMBINATION WITH SURFACE OBSERVATIONS SHOWS DENSE FOG EXPANDING OVER MOST OF CENTRAL NORTH DAKOTA. BASED ON CURRENT VISIBILITY TRENDS AND LATEST HRRR VISIBILITY FORECAST...HAVE ISSUED A DENSE FOG ADVISORY FOR MOST OF CENTRAL NORTH DAKOTA THROUGH LATE WEDNESDAY MORNING. OTHERWISE...A CLEAR SKY DOMINATES WEST AND NORTH WITH THE LATEST WATER VAPOR IMAGERY SHOWING SUBSIDENCE BEHIND A NORTHERN STREAM SHORTWAVE NOW INTO MINNESOTA. SPLIT FLOW CONTINUES WITH THE SOUTHERN BRANCH EXTENDING FROM THE GREAT BASIN INTO SOUTH DAKOTA. AN UPPER LOW/TROUGH WAS SEEN OVER WESTERN NEVADA EARLY THIS MORNING. EXPECTING PLENTY OF SUNSHINE TODAY WITH TEMPERATURES WARMING INTO THE 70S...AND LOWER 80S IN THE FAR WEST. ALL MODEL GUIDANCE...WITH THE EXCEPTION OF THE GFS...ARE IN AGREEMENT THAT THE SOUTHERN BRANCH MAKES A RETURN INTO SOUTHERN NORTH DAKOTA WEDNESDAY NIGHT. AS THE AFOREMENTIONED GREAT BASIN LOW/TROUGH SHIFTS EAST...A SURFACE LOW WILL TAKE SHAPE OVER NEBRASKA AND SOUTH DAKOTA LATER TODAY INTO TONIGHT. LATEST TRENDS INDICATE THE NORTHERN FRINGE OF PRECIPITATION WILL REACH THE JAMES RIVER VALLEY BETWEEN 06Z AND 12Z THURSDAY. AFTER COLLABORATING WITH ABERDEEN AND GRAND FORKS...HAVE INTRODUCED A SLIGHT CHANCE MENTION FOR SHOWERS AND WILL LET SUBSEQUENT SHIFTS LOOK AT THE LATEST DATA TO FINE TUNE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 431 AM CDT WED AUG 27 2014 DURING THIS PERIOD THERE WILL BE SEVERAL COLD FRONTAL PASSAGES THAT WILL BRING SOME ACTIVE WEATHER TO THE REGION OVER THE LABOR DAY WEEKEND. FIRST...THE REMNANTS OF AN UPPER LEVEL LOW WILL TRACK SOUTH OF THE STATE THURSDAY. WHILE THIS FEATURE WILL IMPACT THE AREAS SOUTH OF THE STATE WITH SEVERAL LARGE MCS TYPE CONVECTIVE SYSTEMS...THERE WILL BE SOME RESIDUAL MOISTURE PULLED INTO THE STATE...MAINLY ACROSS THE JAMES RIVER VALLEY THURSDAY MORNING. BUT THERE WILL LIKELY BE MORE CLOUDS THROUGH THE DAY THURSDAY THAN PREVIOUSLY THOUGHT ACROSS A LARGE PORTION OF SOUTHERN AND EASTERN NORTH DAKOTA. AFTER THIS A COLD FRONT WILL ENTER THE NORTHWEST SUPPORTED BY A RATHER WEAK LEADING SHORTWAVE TROUGH AHEAD OF A MORE SIGNIFICANT SHORTWAVE STILL LINGERING ACROSS THE NORTHWEST US FRIDAY. OVERALL...HAVE DOWN PLAYED THE POPS THURSDAY NIGHT AND FRIDAY...WAITING INSTEAD FOR THE MORE SIGNIFICANT SHORTWAVE DUE IN SATURDAY NIGHT AND SUNDAY. WITH THIS NEXT SYSTEM WILL SEE MORE SIGNIFICANT PRECIPITATION WITH STRONGER WARM/COLD FRONTAL PASSAGES. SO THE HOLIDAY WEEKEND SHOULD BE A BIT SOGGY SATURDAY NIGHT WITH SCATTERED SHOWERS ON SUNDAY. COOL CYCLONIC FLOW ALOFT SHOULD MAINTAIN SLIGHT THREAT FOR THUNDERSTORMS MONDAY AND TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 950 AM CDT WED AUG 27 2014 FOG LIFTING AT KBIS AND KJMS AND SHOULD BE VFR BY 15 UTC OR SHORTLY THEREAFTER. VFR CONDITIONS EXPECTED THE REST OF THE DAY...THEN CLOUDS/LOW VFR CIGS RETURN TO KBIS/KJMS WEDNESDAY NIGHT...WITH A VCSH AT KJMS AFTER 08Z THURSDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING FOR NDZ019>023-025-034>037-041-042-044>048-050-051. && $$ UPDATE...TWH SHORT TERM...KS LONG TERM...WAA AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
627 AM CDT WED AUG 27 2014 .UPDATE... ISSUED AT 623 AM CDT WED AUG 27 2014 REFINED THE FOG AREAS TO REFLECT FOG OVER MOST OF THE WEST AND CENTRAL THIS MORNING. LEFT THE ADVISORY AREA IN PLACE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 431 AM CDT WED AUG 27 2014 FOR THE NEAR TERM/EARLY THIS MORNING...THE CURRENT FOG/STRATUS IMAGERY LOOP IN COMBINATION WITH SURFACE OBSERVATIONS SHOWS DENSE FOG EXPANDING OVER MOST OF CENTRAL NORTH DAKOTA. BASED ON CURRENT VISIBILITY TRENDS AND LATEST HRRR VISIBILITY FORECAST...HAVE ISSUED A DENSE FOG ADVISORY FOR MOST OF CENTRAL NORTH DAKOTA THROUGH LATE WEDNESDAY MORNING. OTHERWISE...A CLEAR SKY DOMINATES WEST AND NORTH WITH THE LATEST WATER VAPOR IMAGERY SHOWING SUBSIDENCE BEHIND A NORTHERN STREAM SHORTWAVE NOW INTO MINNESOTA. SPLIT FLOW CONTINUES WITH THE SOUTHERN BRANCH EXTENDING FROM THE GREAT BASIN INTO SOUTH DAKOTA. AN UPPER LOW/TROUGH WAS SEEN OVER WESTERN NEVADA EARLY THIS MORNING. EXPECTING PLENTY OF SUNSHINE TODAY WITH TEMPERATURES WARMING INTO THE 70S...AND LOWER 80S IN THE FAR WEST. ALL MODEL GUIDANCE...WITH THE EXCEPTION OF THE GFS...ARE IN AGREEMENT THAT THE SOUTHERN BRANCH MAKES A RETURN INTO SOUTHERN NORTH DAKOTA WEDNESDAY NIGHT. AS THE AFOREMENTIONED GREAT BASIN LOW/TROUGH SHIFTS EAST...A SURFACE LOW WILL TAKE SHAPE OVER NEBRASKA AND SOUTH DAKOTA LATER TODAY INTO TONIGHT. LATEST TRENDS INDICATE THE NORTHERN FRINGE OF PRECIPITATION WILL REACH THE JAMES RIVER VALLEY BETWEEN 06Z AND 12Z THURSDAY. AFTER COLLABORATING WITH ABERDEEN AND GRAND FORKS...HAVE INTRODUCED A SLIGHT CHANCE MENTION FOR SHOWERS AND WILL LET SUBSEQUENT SHIFTS LOOK AT THE LATEST DATA TO FINE TUNE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 431 AM CDT WED AUG 27 2014 DURING THIS PERIOD THERE WILL BE SEVERAL COLD FRONTAL PASSAGES THAT WILL BRING SOME ACTIVE WEATHER TO THE REGION OVER THE LABOR DAY WEEKEND. FIRST...THE REMNANTS OF AN UPPER LEVEL LOW WILL TRACK SOUTH OF THE STATE THURSDAY. WHILE THIS FEATURE WILL IMPACT THE AREAS SOUTH OF THE STATE WITH SEVERAL LARGE MCS TYPE CONVECTIVE SYSTEMS...THERE WILL BE SOME RESIDUAL MOISTURE PULLED INTO THE STATE...MAINLY ACROSS THE JAMES RIVER VALLEY THURSDAY MORNING. BUT THERE WILL LIKELY BE MORE CLOUDS THROUGH THE DAY THURSDAY THAN PREVIOUSLY THOUGHT ACROSS A LARGE PORTION OF SOUTHERN AND EASTERN NORTH DAKOTA. AFTER THIS A COLD FRONT WILL ENTER THE NORTHWEST SUPPORTED BY A RATHER WEAK LEADING SHORTWAVE TROUGH AHEAD OF A MORE SIGNIFICANT SHORTWAVE STILL LINGERING ACROSS THE NORTHWEST US FRIDAY. OVERALL...HAVE DOWN PLAYED THE POPS THURSDAY NIGHT AND FRIDAY...WAITING INSTEAD FOR THE MORE SIGNIFICANT SHORTWAVE DUE IN SATURDAY NIGHT AND SUNDAY. WITH THIS NEXT SYSTEM WILL SEE MORE SIGNIFICANT PRECIPITATION WITH STRONGER WARM/COLD FRONTAL PASSAGES. SO THE HOLIDAY WEEKEND SHOULD BE A BIT SOGGY SATURDAY NIGHT WITH SCATTERED SHOWERS ON SUNDAY. COOL CYCLONIC FLOW ALOFT SHOULD MAINTAIN SLIGHT THREAT FOR THUNDERSTORMS MONDAY AND TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 623 AM CDT WED AUG 27 2014 AREAS OF DENSE FOG FROM KBIS TO KJMS WILL POSE AS THE HIGHEST IMPACT TO AVIATION THROUGH 14Z WEDNESDAY WITH VLIFR CIGS/VSBYS. FROM 14Z THROUGH 16Z EXPECT A GRADUAL IMPROVEMENT TO MVFR THEN VFR. KDIK WILL LIKELY SEE A BRIEF PERIOD OF LIFR CIGS AND MVFR VSBYS THROUGH 15Z. VFR CONDITIONS EXPECTED THE REST OF THE DAY...THEN CLOUDS/LOW VFR CIGS RETURN TO KBIS/KJMS WEDNESDAY NIGHT...WITH A VCSH AT KJMS AFTER 08Z THURSDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING FOR NDZ019>023-025-034>037-041-042-044>048-050-051. && $$ UPDATE...WAA SHORT TERM...KS LONG TERM...WAA AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
431 AM CDT WED AUG 27 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 431 AM CDT WED AUG 27 2014 FOR THE NEAR TERM/EARLY THIS MORNING...THE CURRENT FOG/STRATUS IMAGERY LOOP IN COMBINATION WITH SURFACE OBSERVATIONS SHOWS DENSE FOG EXPANDING OVER MOST OF CENTRAL NORTH DAKOTA. BASED ON CURRENT VISIBILITY TRENDS AND LATEST HRRR VISIBILITY FORECAST...HAVE ISSUED A DENSE FOG ADVISORY FOR MOST OF CENTRAL NORTH DAKOTA THROUGH LATE WEDNESDAY MORNING. OTHERWISE...A CLEAR SKY DOMINATES WEST AND NORTH WITH THE LATEST WATER VAPOR IMAGERY SHOWING SUBSIDENCE BEHIND A NORTHERN STREAM SHORTWAVE NOW INTO MINNESOTA. SPLIT FLOW CONTINUES WITH THE SOUTHERN BRANCH EXTENDING FROM THE GREAT BASIN INTO SOUTH DAKOTA. AN UPPER LOW/TROUGH WAS SEEN OVER WESTERN NEVADA EARLY THIS MORNING. EXPECTING PLENTY OF SUNSHINE TODAY WITH TEMPERATURES WARMING INTO THE 70S...AND LOWER 80S IN THE FAR WEST. ALL MODEL GUIDANCE...WITH THE EXCEPTION OF THE GFS...ARE IN AGREEMENT THAT THE SOUTHERN BRANCH MAKES A RETURN INTO SOUTHERN NORTH DAKOTA WEDNESDAY NIGHT. AS THE AFOREMENTIONED GREAT BASIN LOW/TROUGH SHIFTS EAST...A SURFACE LOW WILL TAKE SHAPE OVER NEBRASKA AND SOUTH DAKOTA LATER TODAY INTO TONIGHT. LATEST TRENDS INDICATE THE NORTHERN FRINGE OF PRECIPITATION WILL REACH THE JAMES RIVER VALLEY BETWEEN 06Z AND 12Z THURSDAY. AFTER COLLABORATING WITH ABERDEEN AND GRAND FORKS...HAVE INTRODUCED A SLIGHT CHANCE MENTION FOR SHOWERS AND WILL LET SUBSEQUENT SHIFTS LOOK AT THE LATEST DATA TO FINE TUNE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 431 AM CDT WED AUG 27 2014 DURING THIS PERIOD THERE WILL BE SEVERAL COLD FRONTAL PASSAGES THAT WILL BRING SOME ACTIVE WEATHER TO THE REGION OVER THE LABOR DAY WEEKEND. FIRST...THE REMNANTS OF AN UPPER LEVEL LOW WILL TRACK SOUTH OF THE STATE THURSDAY. WHILE THIS FEATURE WILL IMPACT THE AREAS SOUTH OF THE STATE WITH SEVERAL LARGE MCS TYPE CONVECTIVE SYSTEMS...THERE WILL BE SOME RESIDUAL MOISTURE PULLED INTO THE STATE...MAINLY ACROSS THE JAMES RIVER VALLEY THURSDAY MORNING. BUT THERE WILL LIKELY BE MORE CLOUDS THROUGH THE DAY THURSDAY THAN PREVIOUSLY THOUGHT ACROSS A LARGE PORTION OF SOUTHERN AND EASTERN NORTH DAKOTA. AFTER THIS A COLD FRONT WILL ENTER THE NORTHWEST SUPPORTED BY A RATHER WEAK LEADING SHORTWAVE TROUGH AHEAD OF A MORE SIGNIFICANT SHORTWAVE STILL LINGERING ACROSS THE NORTHWEST US FRIDAY. OVERALL...HAVE DOWN PLAYED THE POPS THURSDAY NIGHT AND FRIDAY...WAITING INSTEAD FOR THE MORE SIGNIFICANT SHORTWAVE DUE IN SATURDAY NIGHT AND SUNDAY. WITH THIS NEXT SYSTEM WILL SEE MORE SIGNIFICANT PRECIPITATION WITH STRONGER WARM/COLD FRONTAL PASSAGES. SO THE HOLIDAY WEEKEND SHOULD BE A BIT SOGGY SATURDAY NIGHT WITH SCATTERED SHOWERS ON SUNDAY. COOL CYCLONIC FLOW ALOFT SHOULD MAINTAIN SLIGHT THREAT FOR THUNDERSTORMS MONDAY AND TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 431 AM CDT WED AUG 27 2014 WIDESPREAD DENSE FOG FROM KBIS TO KJMS WILL POSE AS THE HIGHEST IMPACT TO AVIATION THROUGH 16Z WEDNESDAY. EXPECT VLIFR CIGS/VSBYS THROUGH 16Z WEDNESDAY. OTHERWISE SKC FOR THE REMAINING TERMINALS WITH LIGHT WINDS THROUGH 00Z THURSDAY. MOISTURE IS FORECAST TO RETURN TO KBIS/KJMS WEDNESDAY NIGHT RESULTING IN A SLIGHT CHANCE FOR SHOWERS AT KJMS. MVFR CIGS POSSIBLE AT BOTH KBIS AND KJMS AFTER 01Z THURSDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING FOR NDZ019>023-025-034>037-041-042-044>048-050-051. && $$ SHORT TERM...KS LONG TERM...WAA AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
421 AM CDT WED AUG 27 2014 .UPDATE... ISSUED AT 421 AM CDT WED AUG 27 2014 DENSE FOG CONTINUES TO FORM OVER MOST OF CENTRAL NORTH DAKOTA. WITH VISIBILITIES AT OR LESS THAN ONE QUARTER OF A MILE IN SEVERAL LOCATIONS. A DENSE FOG ADVISORY HAS BEEN ISSUED. UPDATES TO PRODUCTS FORTHCOMING. UPDATE ISSUED AT 1157 PM CDT TUE AUG 26 2014 LATEST FOG/STRATUS LOOP SHOWS MOSTLY CLOUDY TO CLOUDY CONDITIONS FROM BISMARCK/MANDAN...EAST AND SOUTH. A CLEAR SKY WAS OBSERVED ELSEWHERE. LATEST HRRR CIG/VSBY FORECAST SHOWS CLOUDS ERODING WHICH IS ON TRACK PER SATELLITE LOOP OVER THE LAST HOUR. HOWEVER THIS AREA OF CLEARING IS REPLACED BY FOG OVERNIGHT WHERE WE HAD THE LIGHT RAIN EARLIER TUESDAY. CONCUR WITH THIS IDEA...BUT UNCERTAINTY ON HOW WIDESPREAD AND DENSE FOG WILL BECOME IS THE MAIN ISSUE FOR THE REST OF THE OVERNIGHT PERIOD. WILL CONTINUE WITH THE CURRENT PATCHY FOG WORDING AND MONITOR OVERNIGHT. REST OF FORECAST ELEMENTS ARE ON TRACK. UPDATE ISSUED AT 1000 PM CDT TUE AUG 26 2014 CONTINUED TREND TO DECREASE RAIN SOUTHEAST...LAMOURE AND DICKEY COUNTIES...OVER THE NEXT TWO HOURS...AND DECREASE CLOUDS THROUGH THE NIGHT. PATCHY FOG CONTINUES IN THE FORECAST FOR THE DAYBREAK TIME FRAME. JP MARTIN UPDATE ISSUED AT 735 PM CDT TUE AUG 26 2014 HAVE TIMED THE SHOWERS OUT OF THE SOUTHEAST ART OF THE FORECAST AREA FOR BETWEEN 10 AND 11 PM CDT THIS EVENING. THEN DECREASED CLOUDS NORTHWEST TO SOUTHEAST. HAVE INTRODUCED PATCHY FOG ACROSS THE SOUTH...FROM BOWMAN AND BISMARCK TO ELLENDALE AND JAMESTOWN FOR AROUND DAYBREAK. DEW POINTS ARE FORECAST TO DROP INTO THE UPPER 40S WITH ACTUAL TEMPERATURES IN THE SAME BALLPARK. THIS IS ALSO THE AREA THAT RECEIVED LIGHT RAIN THIS AFTERNOON / EVENING. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 310 PM CDT TUE AUG 26 2014 LATEST SATELLITE IMAGERY SHOWS A NICE SHORTWAVE TROUGH CURRENTLY DROPPING SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN...IN ADDITION TO AN AREA OF STRONG UPPER LEVEL FLOW ACROSS THE CENTRAL/NORTHERN ROCKIES INTO THE DAKOTAS. THIS HAS PRODUCED SUFFICIENT FORCING...COMBINED WITH WEAK ISENTROPIC LIFT TO PRODUCE A NARROW BAND OF SHOWERS ACROSS SOUTHWEST INTO SOUTH CENTRAL NORTH DAKOTA. THE PAST FEW RUNS OF THE RAP/HRRR HAVE COME INTO BETTER AGREEMENT IN SPREADING THIS BAND ACROSS CENTRAL AND INTO EASTERN NORTH DAKOTA...ALONG AND SOUTH OF INTERSTATE 94. AREAS AFFECTED WILL REMAIN CONFINED TO AN PRETTY NARROW BAND WITH RAINFALL AMOUNTS OF ONLY A COUPLE HUNDREDTHS. EXPECT THESE SHOWERS TO EXIT THE JAMES RIVER VALLEY LATER THIS EVENING WITH CLEAR TO PARTLY CLOUDY SKIES THEREAFTER. STILL A COOL NIGHT IN STORE...BUT WITH LOW-MID LEVEL TEMPERATURES EXPECTED TO CONTINUE TO WARM...LOWS TONIGHT SHOULD BE MAINLY IN THE 40S TO LOWER 50S. WEAK UPPER LEVEL RIDGING ON WEDNESDAY WILL HELP BUMP OUR DAYTIME TEMPERATURES INTO THE 70S...WITH A FEW LOWER 80S POSSIBLE FAR WEST. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 310 PM CDT TUE AUG 26 2014 QUIET/ZONAL FLOW AT THE ONSET OF THE LONG TERM PERIOD WILL TRANSITION TO MORE ACTIVE LATE THURSDAY NIGHT THROUGH THE WEEKEND AS AN UPPER TROUGH MOVES INLAND AND ACROSS THE CENTRAL CONUS. DRY CONDITIONS PREVAIL WEDNESDAY NIGHT THROUGH THURSDAY EVENING WITH THE MAIN STORM TRACKS NORTH AND SOUTH OF NORTH DAKOTA. EMBEDDED LEAD S/WV IMPULSE EJECTING OUT OF AN ALASKAN LONG WAVE TROUGH IS THEN DEPICTED TO APPROACH AND MOVE ACROSS THE NORTHERN PLAINS LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON BRINGING AN ISOLATED THREAT FOR THUNDERSTORMS TO THE REGION. BETTER AND MORE WIDESPREAD PRECIPITATION CHANCES ARRIVE SATURDAY NIGHT INTO EARLY NEXT WEEK WHEN OUR FLOW ALOFT BECOMES SOUTHWESTERLY AS THE AFOREMENTIONED LONG WAVE TROUGH DEVELOPS SOUTHWEST INTO THE PACIFIC NORTHWEST...THEN MOVES EAST ACROSS THE ROCKIES AND THROUGH THE GREAT PLAINS. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY BELOW NORMAL...WITH HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE UPPER 40S AND 50S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1157 PM CDT TUE AUG 26 2014 LIGHT RAIN FROM TUESDAY...ALONG WITH DECREASING CLOUDS AND LIGHT WINDS AT KBIS TO KJMS WILL PROMOTE FOG DEVELOPMENT THROUGH 15Z WEDNESDAY. WILL MAINTAIN MVFR VSBYS FOR THE 06Z TAF ISSUANCE AND MONITOR OVERNIGHT FOR POSSIBLE ADJUSTMENTS DOWNWARD. OTHERWISE...SKC FOR THE REMAINING TERMINALS WITH LIGHT WINDS THROUGH 00Z THURSDAY. INDICATION BEYOND 00Z THURSDAY IS POTENTIAL FOR MVFR CIGS APPEARING AT KBIS AND KJMS AS MOISTURE IS FORECAST TO MOVE NORTH FROM SOUTH DAKOTA WEDNESDAY NIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 11 AM CDT /10 AM MDT/ THIS MORNING FOR NDZ019>023-025-034>037-041-042-044>048-050-051. && $$ UPDATE...KS SHORT TERM...TWH LONG TERM...NH AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1157 PM CDT TUE AUG 26 2014 .UPDATE... ISSUED AT 1157 PM CDT TUE AUG 26 2014 LATEST FOG/STRATUS LOOP SHOWS MOSTLY CLOUDY TO CLOUDY CONDITIONS FROM BISMARCK/MANDAN...EAST AND SOUTH. A CLEAR SKY WAS OBSERVED ELSEWHERE. LATEST HRRR CIG/VSBY FORECAST SHOWS CLOUDS ERODING WHICH IS ON TRACK PER SATELLITE LOOP OVER THE LAST HOUR. HOWEVER THIS AREA OF CLEARING IS REPLACED BY FOG OVERNIGHT WHERE WE HAD THE LIGHT RAIN EARLIER TUESDAY. CONCUR WITH THIS IDEA...BUT UNCERTAINTY ON HOW WIDESPREAD AND DENSE FOG WILL BECOME IS THE MAIN ISSUE FOR THE REST OF THE OVERNIGHT PERIOD. WILL CONTINUE WITH THE CURRENT PATCHY FOG WORDING AND MONITOR OVERNIGHT. REST OF FORECAST ELEMENTS ARE ON TRACK. UPDATE ISSUED AT 1000 PM CDT TUE AUG 26 2014 CONTINUED TREND TO DECREASE RAIN SOUTHEAST...LAMOURE AND DICKEY COUNTIES...OVER THE NEXT TWO HOURS...AND DECREASE CLOUDS THROUGH THE NIGHT. PATCHY FOG CONTINUES IN THE FORECAST FOR THE DAYBREAK TIME FRAME. JP MARTIN UPDATE ISSUED AT 735 PM CDT TUE AUG 26 2014 HAVE TIMED THE SHOWERS OUT OF THE SOUTHEAST ART OF THE FORECAST AREA FOR BETWEEN 10 AND 11 PM CDT THIS EVENING. THEN DECREASED CLOUDS NORTHWEST TO SOUTHEAST. HAVE INTRODUCED PATCHY FOG ACROSS THE SOUTH...FROM BOWMAN AND BISMARCK TO ELLENDALE AND JAMESTOWN FOR AROUND DAYBREAK. DEW POINTS ARE FORECAST TO DROP INTO THE UPPER 40S WITH ACTUAL TEMPERATURES IN THE SAME BALLPARK. THIS IS ALSO THE AREA THAT RECEIVED LIGHT RAIN THIS AFTERNOON / EVENING. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 310 PM CDT TUE AUG 26 2014 LATEST SATELLITE IMAGERY SHOWS A NICE SHORTWAVE TROUGH CURRENTLY DROPPING SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN...IN ADDITION TO AN AREA OF STRONG UPPER LEVEL FLOW ACROSS THE CENTRAL/NORTHERN ROCKIES INTO THE DAKOTAS. THIS HAS PRODUCED SUFFICIENT FORCING...COMBINED WITH WEAK ISENTROPIC LIFT TO PRODUCE A NARROW BAND OF SHOWERS ACROSS SOUTHWEST INTO SOUTH CENTRAL NORTH DAKOTA. THE PAST FEW RUNS OF THE RAP/HRRR HAVE COME INTO BETTER AGREEMENT IN SPREADING THIS BAND ACROSS CENTRAL AND INTO EASTERN NORTH DAKOTA...ALONG AND SOUTH OF INTERSTATE 94. AREAS AFFECTED WILL REMAIN CONFINED TO AN PRETTY NARROW BAND WITH RAINFALL AMOUNTS OF ONLY A COUPLE HUNDREDTHS. EXPECT THESE SHOWERS TO EXIT THE JAMES RIVER VALLEY LATER THIS EVENING WITH CLEAR TO PARTLY CLOUDY SKIES THEREAFTER. STILL A COOL NIGHT IN STORE...BUT WITH LOW-MID LEVEL TEMPERATURES EXPECTED TO CONTINUE TO WARM...LOWS TONIGHT SHOULD BE MAINLY IN THE 40S TO LOWER 50S. WEAK UPPER LEVEL RIDGING ON WEDNESDAY WILL HELP BUMP OUR DAYTIME TEMPERATURES INTO THE 70S...WITH A FEW LOWER 80S POSSIBLE FAR WEST. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 310 PM CDT TUE AUG 26 2014 QUIET/ZONAL FLOW AT THE ONSET OF THE LONG TERM PERIOD WILL TRANSITION TO MORE ACTIVE LATE THURSDAY NIGHT THROUGH THE WEEKEND AS AN UPPER TROUGH MOVES INLAND AND ACROSS THE CENTRAL CONUS. DRY CONDITIONS PREVAIL WEDNESDAY NIGHT THROUGH THURSDAY EVENING WITH THE MAIN STORM TRACKS NORTH AND SOUTH OF NORTH DAKOTA. EMBEDDED LEAD S/WV IMPULSE EJECTING OUT OF AN ALASKAN LONG WAVE TROUGH IS THEN DEPICTED TO APPROACH AND MOVE ACROSS THE NORTHERN PLAINS LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON BRINGING AN ISOLATED THREAT FOR THUNDERSTORMS TO THE REGION. BETTER AND MORE WIDESPREAD PRECIPITATION CHANCES ARRIVE SATURDAY NIGHT INTO EARLY NEXT WEEK WHEN OUR FLOW ALOFT BECOMES SOUTHWESTERLY AS THE AFOREMENTIONED LONG WAVE TROUGH DEVELOPS SOUTHWEST INTO THE PACIFIC NORTHWEST...THEN MOVES EAST ACROSS THE ROCKIES AND THROUGH THE GREAT PLAINS. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY BELOW NORMAL...WITH HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE UPPER 40S AND 50S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1157 PM CDT TUE AUG 26 2014 LIGHT RAIN FROM TUESDAY...ALONG WITH DECREASING CLOUDS AND LIGHT WINDS AT KBIS TO KJMS WILL PROMOTE FOG DEVELOPMENT THROUGH 15Z WEDNESDAY. WILL MAINTAIN MVFR VSBYS FOR THE 06Z TAF ISSUANCE AND MONITOR OVERNIGHT FOR POSSIBLE ADJUSTMENTS DOWNWARD. OTHERWISE...SKC FOR THE REMAINING TERMINALS WITH LIGHT WINDS THROUGH 00Z THURSDAY. INDICATION BEYOND 00Z THURSDAY IS POTENTIAL FOR MVFR CIGS APPEARING AT KBIS AND KJMS AS MOISTURE IS FORECAST TO MOVE NORTH FROM SOUTH DAKOTA WEDNESDAY NIGHT. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...TWH LONG TERM...NH AVIATION...KS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
428 PM EDT WED AUG 27 2014 .SYNOPSIS... A COLD FRONT OVER NORTHERN PENNSYLVANIA WILL CLEAR THE SOUTHERN TIER OF THE STATE EARLY TONIGHT. HIGH PRESSURE WILL ARRIVE BEHIND THE FRONT AND BRING DRY WEATHER TO THE AREA THROUGH THE END OF THE WEEK. ABOVE NORMAL TEMPERATURES AND INCREASINGLY HUMID AND UNSETTLED CONDITIONS ARE FORECAST OVER THE LABOR DAY HOLIDAY WEEKEND AND INTO THE FIRST WEEK OF SEPTEMBER. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... FIRST FEW SHRA/TSRA NOW SHOWING UP OVER KPIT/KAGC AND OVER THE KCCX SITE ITSELF ON TOP OF RATTLESNAKE RIDGE. COVERAGE IS STILL EXPECTED TO BE RATHER SPARSE BUT THE BACKYARD LOOKS LIKE IT WILL GET WET SOON. HRRR AND RAP STILL PLACE BIGGER CONCENTRATION OF SHOWERS THIS EVENING WHERE LLVL CONVERGENCE IS BEST - OVER THE NERO MTG AND POCONOS...AND IN THE LAURELS. HOWEVER...THE SHOWERS IN BLACK SHOW THAT THE HOT TEMPS TODAY ARE COOKING UP PLENTY OF INSTABILITY. THE CAPES COULD BE HEALTHY ENOUGH TO MAKE SOME OF THE STORMS TAP INTO SOME OF THE 35-40KT WINDS ALOFT. SPIC CONTINUES TO MENTION AREA IN THE DAY1 OUTLOOK. SO...SOME MARGINAL WIND GUSTS ARE STILL POSSIBLE...BUT NOT WIDESPREAD. THE COLD FRONT LAGS BEHIND THE CURRENT CONVECTION AND WILL LIKELY FIRE UP MORE ISOLD/SCT CONVECTION AS IT MOVES INTO THE MORE-HUMID AIR OVER THE CENTRAL AND SERN COS. POPS IN THE CHC/SCT CATEGORY FOR ANY ONE HOUR STILL SEEM LIKE THE BEST APPROACH. THE FRONT AND DRIER AIR SHOULD ARRIVE IN THE CENTRAL COS AROUND SUNSET AND MOVE OUT OF THE CWA HEADED SOUTH AROUND MIDNIGHT. SKIES SHOULD CLEAR OUT NICELY BEHIND THE FRONT AND TEMPS COULD GET INTO THE 40S IN THE NAN MTG. ALSO...DECOUPLING SHOULD OCCUR IN MOST PLACES. THUS...YE OLDEN RIVER VALLEY FOG IS EXPECTED THERE. MINS WILL PROBABLY STAY IN THE L60S IN THE SRN TIER. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... COOL POST-FRONTAL NW FLOW WILL MAKE FOR A MOSTLY SUNNY DAY OVER MOST OF THE REGION. THE ONLY FLY IN THE OINTMENT MIGHT BE THE APPROACH OF A LOWER CLOUD DECK FROM THE N/NE AS A STRONG PORT MAX DROPS S ACROSS NY STATE. WILL KEEP POPS UP NEAR ISOLD NUMBERS IN THE NE...BUT NOT MENTION PRECIP QUITE YET. A SPRINKLE IS POSSIBLE IN THE NE THOUGH. MAXES WILL BE ABOUT 8-10F BELOW WEDNESDAY/S LOFTY NUMBERS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... THE MEDIUM RANGE FLOW PATTERN WILL FEATURE TROUGHING IN THE WEST AND FAIRLY HIGH HEIGHTS FCST TO PREVAIL OVER THE EAST SUPPORTED BY A SUBTROPICAL RIDGE THAT SHOULD ANCHOR OVER THE SOUTHEAST. THIS RIDGE WILL ALLOW HIGH PRESSURE TO CENTER OVER UPSTATE NY AT THE START OF THE PERIOD. THIS WILL SLOWLY MOVE OFF THE NEW ENGLAND COAST ON SATURDAY. A LONG FRONTAL BOUNDARY EXTENDING FROM AN UPPER LEVEL LOW CENTERED OVER NORTHERN CANADA...AND TO A NEGATIVELY TILTING TROUGH WHICH SHOULD BE MOVING INTO THE MIDWEST. THE BIGGEST MOISTURE FROM THE FRONTAL BOUNDARY IS PROGGED TO STAY NORTH OF PA. HOWEVER...THERE SHOULD BE ENOUGH MOISTURE...WITH ENOUGH FORCING TO WARRANT INCREASING PROBABILITY/OPPORTUNITY FOR RAIN SATURDAY NIGHT INTO EARLY MONDAY. DAYTIME CONVECTION WILL ALSO BE SPURRED ON BY A WARMING TREND WITH MAX TEMPS 5-10F ABOVE NORMAL OVER THE WEEKEND AND INTO THE FIRST WEEK OF SEPT. THE BEST CHANCE FOR PRECIPITATION THROUGH THIS TIMEFRAME SHOULD BE SUNDAY AFTERNOON INTO SUNDAY EVENING. THERE IS SOME MODEL VARIATION SO EXPECT SOME MODIFICATIONS AS TIME PROGRESSES. A GFS AND EC IN THE LONG RANGE ARE ACTUALLY IN FAIR AGREEMENT THROUGH THE FIRST HALF OF NEXT WEEK...INCLUDING THE SUBSTANTIAL TROUGH THAT SHOULD MOVE THROUGH WEDNESDAY AS MORE DEFINED COLD FRONT SHOULD APPROACHES THE AREA. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... COLD FRONT APPEARS TO BE JUST THROUGH KBFD AT 18Z. ONE BATCH OF TSRA OVER KAGC IS HEADED SOUTH OF KJST. ALL BUT KBFD WILL CONTINUE TO HAVE THE POSSIBILITY FOR TSRA IN THE VCTY...BUT HAVE ONLY INCLUDED VCSH/TS FOR NOW DUE TO SPARSE COVERAGE. THIS THREAT SHOULD END AROUND 23Z-00Z IN IPT/UNV BUT COULD LINGER UNTIL 03Z IN THE SRN TERMINALS. WIND SHIFT TO THE NW BEHIND THE FRONT WILL BRING DRIER AND COOLER AIR. NORMAL VALLEY FOG IS EXPECTED IN THE NRN VALLEYS AS THE TEMPS DROP OFF WELL BELOW THE RIVER WATER TEMPS. BUT THERE COULD BE A LITTLE WIND WHICH COULD IMPEDE FOG FORMATION. WILL PUT MVFR FOG IN MOST TAFS AND IFR FOG IN BFD FOR A FEW HRS LATE TONIGHT. THE NW WINDS PICK UP AFTER SUNRISE BUT SKIES AND VIS SHOULD BE VFR. A LOW-END VFR CLOUD DECK MAY DROP DOWN FROM WRN NY STATE DURING THE DAYLIGHT HRS ON THURS. OUTLOOK... FRI-SAT...EARLY MORNING FOG RESTRICTIONS POSSIBLE...OTHERWISE VFR. SUN-MON...MAINLY VFR. SCT AFTERNOON SHOWERS/TSTMS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...CERU/STEINBUGL AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
256 PM EDT WED AUG 27 2014 .SYNOPSIS... A COLD FRONT OVER NORTHERN PENNSYLVANIA WILL CLEAR THE SOUTHERN TIER OF THE STATE EARLY TONIGHT. HIGH PRESSURE WILL ARRIVE BEHIND THE FRONT AND BRING DRY WEATHER TO THE AREA THROUGH THE END OF THE WEEK. ABOVE NORMAL TEMPERATURES AND INCREASINGLY HUMID AND UNSETTLED CONDITIONS ARE FORECAST OVER THE LABOR DAY HOLIDAY WEEKEND AND INTO THE FIRST WEEK OF SEPTEMBER. && .NEAR TERM /THROUGH TONIGHT/... FIRST FEW SHRA/TSRA NOW SHOWING UP OVER KPIT/KAGC AND OVER THE KCCX SITE ITSELF ON TOP OF RATTLESNAKE RIDGE. COVERAGE IS STILL EXPECTED TO BE RATHER SPARSE BUT THE BACKYARD LOOKS LIKE IT WILL GET WET SOON. HRRR AND RAP STILL PLACE BIGGER CONCENTRATION OF SHOWERS THIS EVENING WHERE LLVL CONVERGENCE IS BEST - OVER THE NERO MTG AND POCONOS...AND IN THE LAURELS. HOWEVER...THE SHOWERS IN BLACK SHOW THAT THE HOT TEMPS TODAY ARE COOKING UP PLENTY OF INSTABILITY. THE CAPES COULD BE HEALTHY ENOUGH TO MAKE SOME OF THE STORMS TAP INTO SOME OF THE 35-40KT WINDS ALOFT. SPIC CONTINUES TO MENTION AREA IN THE DAY1 OUTLOOK. SO...SOME MARGINAL WIND GUSTS ARE STILL POSSIBLE...BUT NOT WIDESPREAD. THE COLD FRONT LAGS BEHIND THE CURRENT CONVECTION AND WILL LIKELY FIRE UP MORE ISOLD/SCT CONVECTION AS IT MOVES INTO THE MORE-HUMID AIR OVER THE CENTRAL AND SERN COS. POPS IN THE CHC/SCT CATEGORY FOR ANY ONE HOUR STILL SEEM LIKE THE BEST APPROACH. THE FRONT AND DRIER AIR SHOULD ARRIVE IN THE CENTRAL COS AROUND SUNSET AND MOVE OUT OF THE CWA HEADED SOUTH AROUND MIDNIGHT. SKIES SHOULD CLEAR OUT NICELY BEHIND THE FRONT AND TEMPS COULD GET INTO THE 40S IN THE NAN MTG. ALSO...DECOUPLING SHOULD OCCUR IN MOST PLACES. THUS...YE OLDEN RIVER VALLEY FOG IS EXPECTED THERE. MINS WILL PROBABLY STAY IN THE L60S IN THE SRN TIER. && .SHORT TERM /THURSDAY/... COOL POST-FRONTAL NW FLOW WILL MAKE FOR A MOSTLY SUNNY DAY OVER MOST OF THE REGION. THE ONLY FLY IN THE OINTMENT MIGHT BE THE APPROACH OF A LOWER CLOUD DECK FROM THE N/NE AS A STRONG PORT MAX DROPS S ACROSS NY STATE. WILL KEEP POPS UP NEAR ISOLD NUMBERS IN THE NE...BUT NOT MENTION PRECIP QUITE YET. A SPRINKLE IS POSSIBLE IN THE NE THOUGH. MAXES WILL BE ABOUT 8-10F BELOW WEDNESDAY/S LOFTY NUMBERS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... MEDIUM RANGE FLOW PATTERN ACTS THE ONUS WILL FEATURE DROVING IN THE WEST AND FAIRLY HIGH HEIGHTS FCST TO PREVAIL OVER THE EAST (FOR A CHANGE) SUPPORTED BY SUBTROPICAL RIDGE ANCHORED OVER THE SOUTHEAST. HIGH PRESSURE CENTERED OVER UPSTATE NY AT THE START OF THE PERIOD WILL MOVE OFF THE NAN NEW ENGLAND COAST ON SATURDAY AS TODAYS FRONTAL BOUNDARY PIVOTS BACK NOD AS A WARM FRONT...IN RESPONSE TO SHORTWAVE/SFC WAVE FCST TO TRACK NEED FROM THE ERN PLAINS/MS CLY. OVER THE PAST 12-24 HOURS THE LATEST GUIDANCE HAS TRENDED NOD WITH SFC LOW TRACKS THRU THE GREAT LAKES AROUND D4/SUN AND WITH LEADING FRONTAL BOUNDARY WHICH IS NOW PROGGED BY WP TO STAY NORTH OF PA. A MORE DEFINED COLD FRONT SHOULD APPROACH THE AREA BY THE MIDDLE OF NEXT WEEK. A RATHER MOIST RETURN FLOW AROUND SOUTHEAST RIDGE AND AHEAD MID LVL SHORTWAVE TRACKING NEWD FROM THE ERN PLAINS/MS VLY ALONG WITH INTERACTION WITH ASSOCIATED SFC WAVE/WAVY LEADING FRONTAL ZONE SHOULD SPELL AN INCREASING PROBABILITY/OPPORTUNITY FOR RAIN INTO THE WEEKEND. HOWEVER CONFIDENCE IN PCPN DETAILS (I.E. POPS) IS MEDIUM AT BEST DUE TO MODEL SPREAD/DEPENDENCE ON SMALLER SCALE FEATURES. THE FCST MAY BE PERCEIVED AS SOMEWHAT PESSIMISTIC WITH NEARLY DAILY CHC FOR SHWRS/TSTMS HOWEVER PCPN WILL CERTAINLY NOT BE CONTINUOUS WITH PERIODS OF DRY WX MIXED IN BTWN GENERALLY SCT AND LARGELY DISORGANIZED/WEAKLY FORCED PCPN. THERE IS HIGHER CONFIDENCE IN A WARMING TREND WITH MAX TEMPS 5-10F ABOVE NORMAL OVER THE WEEKEND AND INTO THE FIRST WEEK OF SEPT. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... COLD FRONT APPEARS TO BE JUST THROUGH KBFD AT 18Z. ONE BATCH OF TSRA OVER KAGC IS HEADED SOUTH OF KJST. ALL BUT KBFD WILL CONTINUE TO HAVE THE POSSIBILITY FOR TSRA IN THE VCTY...BUT HAVE ONLY INCLUDED VCSH/TS FOR NOW DUE TO SPARSE COVERAGE. THIS THREAT SHOULD END AROUND 23Z-00Z IN IPT/UNV BUT COULD LINGER UNTIL 03Z IN THE SRN TERMINALS. WIND SHIFT TO THE NW BEHIND THE FRONT WILL BRING DRIER AND COOLER AIR. NORMAL VALLEY FOG IS EXPECTED IN THE NRN VALLEYS AS THE TEMPS DROP OFF WELL BELOW THE RIVER WATER TEMPS. BUT THERE COULD BE A LITTLE WIND WHICH COULD IMPEDE FOG FORMATION. WILL PUT MVFR FOG IN MOST TAFS AND IFR FOG IN BFD FOR A FEW HRS LATE TONIGHT. THE NW WINDS PICK UP AFTER SUNRISE BUT SKIES AND VIS SHOULD BE VFR. A LOW-END VFR CLOUD DECK MAY DROP DOWN FROM WRN NY STATE DURING THE DAYLIGHT HRS ON THURS. OUTLOOK... FRI-SAT...EARLY MORNING FOG RESTRICTIONS POSSIBLE...OTHERWISE VFR. SUN-MON...MAINLY VFR. SCT AFTERNOON SHOWERS/TSTMS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...STEINBUGL AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1011 AM EDT WED AUG 27 2014 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE REGION THIS AFTERNOON AND PROVIDE A FOCUS FOR THUNDERSTORMS. HIGH PRESSURE WILL ARRIVE BEHIND THE FRONT AND BRING DRY WEATHER TO THE AREA THROUGH THE END OF THE WEEK. ABOVE NORMAL TEMPERATURES AND INCREASINGLY HUMID CONDITIONS ARE FORECAST OVER THE LABOR DAY HOLIDAY WEEKEND AND INTO THE FIRST WEEK OF SEPTEMBER. && .NEAR TERM /THROUGH TONIGHT/... 10 AM UPDATE... PATCHY CLOUDS OVER MOST OF THE AREA AT THIS POINT WITH LITTLE TO NO DIURNAL CU DEVELOPMENT. CONVECTIVE TEMPS SHOULD BE REACHED FAIRLY SOON...THOUGH. SOLID CLOUD COVER IN THE NRN TIER IS STARTING TO SHOW SIGNS OF BREAKING UP A BIT. BUT THE FRONT IS MOST LIKELY THE THIN LINE WHICH IS VISIBLE ON KBUF RADAR AS IT COINCIDES WITH THE MOST NOTICABLE WIND SHIFT. LATEST NAM AND THE RAP AND HRRR ALL PRODUCE ISOLD/SCT SHRA/TSRA THIS AFTERNOON AND EARLY EVENING AS THE FRONT PUSHES THROUGH. FEW CHANGES TO THE POPS/WX GRIDS...EXCEPT FOR A LITTLE NUDGE DOWNWARD TO THE NW WITH THE COOLER AIR AND FROPA WHICH SHOULD HAPPEN SOON. SPC CONTINUES TO MENTION THE AREA IN THE DAY1 OUTLOOK FOR ALL THE REASONS OUTLINED BELOW. ITS A WAITING GAME AT THIS POINT. MORE ACTIVITY CENTERED ON THE NERN MTS AND POCONOS AND THE LAURELS THIS AFTN/EVENING...WITH PERHAPS A LULL IN THE CENTRAL MTS WITH DEWPOINTS PERHAPS LOWERING SLIGHTLY DUE TO MIXING BEFORE FROPA. THE HURRICANE OFF THE COAST COULD ALSO CONTRIBUTE TO SOME TINY BIT OF CONVECTIVE SUPPRESSION LOCALLY - BUT IT IS A LITTLE TOO FAR AWAY FOR THAT TO BE A BIG FACTOR. PREV... PATCHY FOG IN THE RIVER/STREAM VALLEYS OF SCENTRL/SERN PA WILL ERODE SHORTLY AFTER SUNRISE WITH LCL VISBYS IMPROVING BY 14Z. CLOUDS ARE INCREASING OVER THE NW MTNS IN ADVANCE OF SFC COLD FRONT SHIFTING SEWD FROM THE LAKE ERIE SHORELINE. A LOW AMPLITUDE UPPER TROUGH OVER THE GREAT LAKES REGION THIS MORNING WILL TRANSLATE EWD INTO THE NORTHEAST STATES TONIGHT AND MOVE OFFSHORE DURING THE D2 PERIOD. AT THE SFC...A COLD FRONT ANALYZED FROM THE ST. LAWRENCE VLY SWWD BACK ACRS THE LWR LKS WILL PUSH SEWD ACRS CENTRAL PA THIS AFTN BEFORE SHIFTING SOUTH OF THE MASON DIXON LINE AFTER 00Z. THE GLOBAL MODELS ARE WELL CLUSTERED WITH THE UPPER TROUGH AND ASSOCIATED COLD FRONT CROSSING THE NORTHEAST...WITH A NON-NAM CONSENSUS SOLUTION PREFERRED BY WPC AS IT APPEARS TO BE STRONGER ALOFT AND A TAD SLOWER WITH THE ADVANCE OF THE SFC FRONT. THE MAIN FCST CONCERN IN THE NEAR TERM IS THE POTENTIAL FOR STRONG TO LOCALLY SVR STORMS THIS AFTN. MODELS ADVECT RICH BLYR MSTR EWD FROM THE OH VLY INTO CENTRAL PA IN ADVANCE OF THE SFC COLD FRONT...WITH 60-65F DEWPOINTS PROGGED BY THE CONSENSUS GUIDANCE. THE NAM IS LKLY TOO MOIST WITH LOW 70S DEWPOINTS. STRONG HEATING AND DESTABILIZATION WILL LEAD TO MU CAPES IN EXCESS OF 1000 J/KG ALONG A NARROW CORRIDOR PRECEDING THE COLD FRONT. THE LOW-MID LVL BACKGROUND WIND FIELDS WILL NOT BE PARTICULARLY STRONG...AND THE BEST DEEP SHEAR LAGS THE FRONT. HOWEVER...A FEW CELLS CAPABLE OF PRODUCING SMALL TO MARGINALLY SEVERE HAIL AND LOCALLY STRONG TO DMGG WIND GUSTS WILL BE POSSIBLE GIVEN COMBO OF "SUFFICIENT" SHEAR AND DECENT INSTABILITY. THE D1 SPC OUTLOOK PLACES THE ERN ZONES IN THE CATEGORICAL SEE TEXT WITH 5% SVR PROBS BUT COULD SEE AN ISOLD SVR STORM FURTHER WEST ACROSS S-CENTRAL PA TO THE LAUREL HIGHLANDS. CONVECTIVE ACTIVITY SHOULD WEAKEN QUICKLY WITH THE LOSS OF DAYTIME HEATING AND EVENTUALLY DISSIPATE/SHIFT S-SEWD AFTER MIDNIGHT. AFTERNOON TEMPS WILL APPROACH 90F FROM THE SCNTRL RIDGE/VALLEY REGION INTO THE LWR SUSQ VLY...WITH UPPER 70S TO LOW 80S COMMON IN THE NW/NCNTRL HIGH TERRAIN. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... HIGH PRESSURE AND MUCH DRIER AIR WITH LOW/COMFORTABLE HUMIDITY WILL OVERSPREAD THE AREA ON THURSDAY. ENS DATA SHOWS TEMPS ALOFT SLIGHTLY BLW NORMAL OVER NRN/NERN PA WHICH SHOULD PROMOTE AFTN CU/SC CLOUDS. TEMPS RANGE FROM AROUND 70F IN THE NW TO 80F IN THE SE. THU NGT LOOKS SEASONABLY COOL WITH VALLEY FOG PROBABLE UNDER SFC RIDGE WITH M/CLR SKIES AND NEARLY CALM WINDS. WAA CLOUDS MAY IMPACT MIN TEMP FCST BUT FOR NOW SEE NO REASON TO DEVIATE FROM CONSENSUS GUIDANCE. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MEDIUM RANGE FLOW PATTERN ACRS THE CONUS WILL FEATURE TROUGHING IN THE WEST AND FAIRLY HIGH HEIGHTS FCST TO PREVAIL OVER THE EAST (FOR A CHANGE) SUPPORTED BY SUBTROPICAL RIDGE ANCHORED OVER THE SOUTHEAST. HIGH PRESSURE CENTERED OVER UPSTATE NY AT THE START OF THE PERIOD WILL MOVE OFF THE NRN NEW ENGLAND COAST ON SATURDAY AS TODAYS FRONTAL BOUNDARY PIVOTS BACK NWD AS A WARM FRONT...IN RESPONSE TO SHORTWAVE/SFC WAVE FCST TO TRACK NEWD FROM THE ERN PLAINS/MS VLY. OVER THE PAST 12-24 HOURS THE LATEST GUIDANCE HAS TRENDED NWD WITH SFC LOW TRACKS THRU THE GREAT LAKES AROUND D4/SUN AND WITH LEADING FRONTAL BOUNDARY WHICH IS NOW PROGGED BY WPC TO STAY NORTH OF PA. A MORE DEFINED COLD FRONT SHOULD APPROACH THE AREA BY THE MIDDLE OF NEXT WEEK. A RATHER MOIST RETURN FLOW AROUND SOUTHEAST RIDGE AND AHEAD MID LVL SHORTWV TRACKING NEWD FROM THE ERN PLAINS/MS VLY ALONG WITH INTERACTION WITH ASSOCIATED SFC WAVE/WAVY LEADING FRONTAL ZONE SHOULD SPELL AN INCREASING PROBABILITY/OPPORTUNITY FOR RAIN INTO THE WEEKEND. HOWEVER CONFIDENCE IN PCPN DETAILS (I.E. POPS) IS MEDIUM AT BEST DUE TO MODEL SPREAD/DEPENDENCE ON SMALLER SCALE FEATURES. THE FCST MAY BE PERCEIVED AS SOMEWHAT PESSIMISTIC WITH NEARLY DAILY CHC FOR SHWRS/TSTMS HOWEVER PCPN WILL CERTAINLY NOT BE CONTINUOUS WITH PERIODS OF DRY WX MIXED IN BTWN GENERALLY SCT AND LARGELY DISORGANIZED/WEAKLY FORCED PCPN. THERE IS HIGHER CONFIDENCE IN A WARMING TREND WITH MAX TEMPS 5-10F ABOVE NORMAL OVER THE WEEKEND AND INTO THE FIRST WEEK OF SEPT. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... LEADING EDGE OF STRATO CU AND LOW-END ALTO CU ASSOCIATED WITH AN AXIS OF MUCH HIGHER PWAT AIR /NEAR 1.75 INCHES FROM NERN OHIO TO SWRN NEW YORK/ WERE DRIFTING INTO THE CENTRAL RIDGE AND VALLEY REGION AT SUNRISE...WHILE SKIES WERE MAINLY CLEAR ACROSS THE SOUTHEASTERN HALF OF THE STATE. LIGHT AND VARIABLE...TO LIGHT SOUTHWESTERLY WIND WAS NOTED AT ALL AIRFIELDS. SFC COLD FRONT WAS SLIDING JUST SE OF THE I-90 CORRIDOR FROM KCLE TO KERI AND KROC ATTM. CLOUD BASES AT KBFD AND KJST SHOULD DIP INTO THE MVFR RANGE AT TIMES LATER THIS MORNING AND EARLY THIS AFTERNOON /WITH SOME OCNL IFR POSSIBLE AT BRADFORD BETWEEN 11-14Z/. THE COLD FRONT WILL DRIFT SLOWLY SE AND CROSS CENTRAL PA AIRFIELDS DURING THE LATE AFTERNOON HOURS...BEFORE REACHING THE LOWER SUSQUEHANNA VALLEY /KMDT AND KLNS/ LATER THIS EVENING. INSTABILITY AND MOISTURE WILL BE QUITE HIGH AHEAD OF THE COLD FRONT...SO INCLUDED VCTS FOR ABOUT A 4-HOUR PERIOD PRECEDING THE FRONTAL PASSAGE. BRIEF MVFR CONDITIONS ARE POSSIBLE IN THE THUNDERSTORMS. MAINLY VFR IS EXPECTED TONIGHT INTO THURSDAY IN THE WAKE OF THE CFROPA. A 6-10 HOUR PERIOD OF NW WINDS AVERAGE 8-10 KTS...WITH GUSTS IN THE MID-UPPER TEENS IS EXPECTED LATE TODAY AND TONIGHT IN THE MDTLY TIGHT LLVL PRESSURE GRADIENT FOLLOWING THE COLD FRONT. OUTLOOK... THU-FRI...LATE NIGHT-EARLY MORNING RESTRICTIONS IN FOG POSSIBLE...OTHERWISE VFR. SAT-SUN...MAINLY VFR. CHC OF AFTERNOON SHOWERS/ISOLD TSTMS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/STEINBUGL NEAR TERM...DANGELO/STEINBUGL SHORT TERM...STEINBUGL LONG TERM...STEINBUGL AVIATION...DANGELO/LAMBERT
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1012 AM MDT WED AUG 27 2014 .UPDATE... ISSUED AT 1012 AM MDT WED AUG 27 2014 CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR NORTHEAST CO...WITH A NEARLY STATIONARY FRONTAL BOUNDARY FROM WESTERN WY TO NORTHEAST KS. UPPER LEVEL ANALYSIS SHOWS LOW PRESSURE OVER EASTERN UT...WITH TROF COVERING THE ROCKIES AND MUCH OF THE HIGH PLAINS. SKIES ARE VARIABLY CLOUDY ACROSS THE AREA...WITH AREAS OF FOG LIFTING OVER EASTERN PORTIONS OF THE CWA. REGIONAL RADARS SHOW MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY IN TWO AREAS. THE MAIN AREA IS OVER SOUTHERN AND CENTRAL WY...MOVING NORTH- NORTHWESTWARD AROUND THE UPPER LOW. ANOTHER AREA OF LIGHTER ACTIVITY IS LOCATED OVER CENTRAL NEB INTO PORTIONS OF SOUTHEAST SD...MOVING NORTH-NORTHEAST. OUR AREA IS DRY AT THE MOMENT...BUT SHOWERS AND STORMS WILL MOVE IN FROM THE SOUTH AND ALSO DEVELOP AS THE UPPER LOW MOVES ACROSS SOUTHERN WY/NORTHERN CO THIS AFTERNOON AND EVENING...ESPECIALLY OVER THE BLACK HILLS AND SOUTHERN PORTIONS OF THE CWA. THERE SHOULD BE A FAIRLY SHARP CUT-OFF TO THE COVERAGE OF SHOWERS... LIKELY SOMEWHERE NEAR OR JUST NORTH OF THE I-90 CORRIDOR. THE THREAT FOR SEVERE STORMS REMAINS LOW WITH MAIN AREA OF INSTABILITY STAYING SOUTH OF THE AREA. HAVE MADE A MINOR UPDATE TO THE FORECAST...MAINLY TO LOWER POPS ACROSS THE AREA THIS MORNING AND RAISE THEM OVER THE BLACK HILLS THIS AFTERNOON. ALSO MADE SOME ADJUSTMENTS TO CLOUD COVER FOR THE NEXT FEW HOURS. TEMP FORECAST FOR TODAY LOOKS GOOD AT THE MOMENT... BUT MAY HAVE TO TWEAK THEM A BIT LATER ON...DEPENDING ON CLOUD AND SHOWER COVERAGE. && .SHORT TERM...TODAY THROUGH THURSDAY NIGHT ISSUED AT 251 AM MDT WED AUG 27 2014 LATEST WATER VAPOR IMAGERY SHOWS AN AREA OF LOW PRESSURE OVER NEVADA/UTAH WITH A NORTHERN STREAM TROUGH EXTENDING FROM CENTRAL CANADA INTO THE NORTHERN PLAINS. THE NORTHERN STREAM TROF WILL QUICKLY MOVE EASTWARD AS THE CUTOFF LOW SLOWLY PROPAGATES INTO THE CENTRAL ROCKIES. SOUTHWESTERLY FLOW CONTINUES OVER THE CENTRAL/NORTHERN PLAINS. FOR TODAY THE BEST FORCING REMAINS SOUTH OF THE CWA. BEST CHANCES OF PRECIP THROUGH THURSDAY WILL BE ACROSS THE FAR SOUTHERN PORTIONS OF THE FORECAST AREA AS A SERIES OF WAVES CROSS THE COLORADO/NEBRASKA AREA. MODELS ARE VARYING WITH TIMING OF WAVES AND HOW FAR NORTH THE PRECIP WILL EXTEND WITHIN THE CWA. EITHER WAY QPF AMOUNTS WILL BE LIMITED...EXCEPT WITH THE POSSIBILITY OF SOME STRONGER STORMS CROSSING AREAS NEAR THE NEBRASKA BORDER. HIGH TEMPERATURES TODAY WILL ONCE AGAIN BE BELOW AVERAGE DUE TO CLOUD COVER. AS THE UPPER LOW MOVES THROUGH NEBRASKA/KANSAS...PRECIP CHANCES WILL DIMINISH ACROSS THE AREA WITH DRY CONDITIONS BY THURSDAY AFTERNOON/EVENING. && .LONG TERM...FRIDAY THROUGH TUESDAY ISSUED AT 251 AM MDT WED AUG 27 2014 PROGRESSIVE NORTHERN STREAM FLOW WILL CONTINUE THROUGH THE PERIOD. TWO MAIN SYSTEMS EXPECTED TO AFFECT THE REGION IN THE PERIOD...A WEAK NORTHERN STREAM TROUGH FRIDAY...AND A MORE ROBUST LONGWAVE UPPER TROUGH SAT NIGHT INTO MONDAY. FORECAST MODELS IN GOOD AGREEMENT PER WAVE AMPLITUDE AND TRACK. HOWEVER...SOME SUBSTANTIAL DIFFERENCES BEGIN TO EMERGE IN THE SUNDAY NIGHT INTO MONDAY PERIOD BETWEEN THE ECMWF AND GFS...MAINLY THE HANDLING OF THE NW CONUS SOUTHERN PERIPHERY EJECTING IMPULSE. THE ECMWF HAS A SOUTHERN BIAS TO THE SYSTEM WITH THE BULK OF LSA PASSING THROUGH THE FA AS OPPOSED TO A MORE NORTHERN TRACK IN THE GFS...WHICH IS ALSO FASTER. THE ECMWF SOLUTION WOULD SUPPORT BETTER CHANCES FOR RAIN IN THE FA HOWEVER MOISTURE LIMITATIONS MAY PRECLUDE ANY PRECIP TOTALS THEN. RETAINED PREV POPS FOR FRIDAY AFTERNOON...WITH A SLIGHT UPTICK AND EXPANSION OF SLIGHT MENTION. FORECAST MODELS CONTINUE TO INDICATE A SFC TROUGH STALLING ACROSS THE SW HALF FRIDAY...WITH A PASSING UPPER LEVEL IMPULSE. SUFFICIENT LL MOISTURE ND RESULTING CAPE WOULD BE CONDUCIVE FOR CONVECTION IN THE AFTERNOON...ESP OVER THE BLACK HILLS. OTHERWISE...A MORE IMPRESSIVE UPPER LEVEL TROUGH WILL PUSH OUT OF THE NE PAC AND INTO THE NORTHERN PLAINS...SUPPORTING INCREASING LSA SAT NIGHT THROUGH SUNDAY NIGHT. BETTER SFC CYCLONE DEVELOPMENT LOOKS TO REMAIN WELL EAST OF THE REGION...SUPPORTING MORE ELEVATED/CONVECTIVE CHANCES BEHIND THE SFC TROUGH RATHER THAN WIDESPREAD DEFORMATION RAINS. HENCE...KEPT POPS IN THE SLIGHT TO LOW CHANCE CAT FOR NOW...ESP AS DEEPER MOISTURE WILL SHIFT QUICKLY EAST OUT OF THE REGION. KEPT MOST OF THE REGION DRY MONDAY THROUGH TUES...WITH UPPER LEVEL RIDGING COMMENCING AND DRY PROFILES. SEASONAL TEMPS EXPECTED IN MOST OF THE PERIOD...WITH BELOW NORMAL TEMPS /5-10 DEGREES/ EXPECTED MONDAY AND PERHAPS TUES BEHIND SUNDAY/S COLD FRONT...ESP NW AREAS. && .AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY NIGHT ISSUED AT 251 AM MDT WED AUG 27 2014 SCT-ISOLD SHOWERS/THUNDERSTORMS EXPECTED ACROSS THE SOUTHERN HALF THROUGH MOST OF THE PERIOD AS A SERIES OF IMPULSES CROSS THE REGION. LCL MVFR/IFR CONDS EXP WITH HEAVIER PRECIPITATION. ADDITIONALLY...IFR CIGS WILL SPREAD NORTH ACROSS SW AND SCENTRAL SD THIS MORNING...WITH CIGS TRENDING TO MVFR LATE MORNING/EARLY AFTERNOON. CIGS MAY LINGER THROUGH THE PERIOD THERE. WINDS WILL VEER SE AROUND KRAP THIS AFTERNOON...WITH THE POTENTIAL FOR MVFR CIGS TO SPREAD INTO THE RAP TERMINAL THEN. HAVE HINTED AT THIS IN THE TAF. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...26 SHORT TERM...MLS LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
254 AM MDT WED AUG 27 2014 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT ISSUED AT 251 AM MDT WED AUG 27 2014 LATEST WATER VAPOR IMAGERY SHOWS AN AREA OF LOW PRESSURE OVER NEVADA/UTAH WITH A NORTHERN STREAM TROUGH EXTENDING FROM CENTRAL CANADA INTO THE NORTHERN PLAINS. THE NORTHERN STREAM TROF WILL QUICKLY MOVE EASTWARD AS THE CUTOFF LOW SLOWLY PROPAGATES INTO THE CENTRAL ROCKIES. SOUTHWESTERLY FLOW CONTINUES OVER THE CENTRAL/NORTHERN PLAINS. FOR TODAY THE BEST FORCING REMAINS SOUTH OF THE CWA. BEST CHANCES OF PRECIP THROUGH THURSDAY WILL BE ACROSS THE FAR SOUTHERN PORTIONS OF THE FORECAST AREA AS A SERIES OF WAVES CROSS THE COLORADO/NEBRASKA AREA. MODELS ARE VARYING WITH TIMING OF WAVES AND HOW FAR NORTH THE PRECIP WILL EXTEND WITHIN THE CWA. EITHER WAY QPF AMOUNTS WILL BE LIMITED...EXCEPT WITH THE POSSIBILITY OF SOME STRONGER STORMS CROSSING AREAS NEAR THE NEBRASKA BORDER. HIGH TEMPERATURES TODAY WILL ONCE AGAIN BE BELOW AVERAGE DUE TO CLOUD COVER. AS THE UPPER LOW MOVES THROUGH NEBRASKA/KANSAS...PRECIP CHANCES WILL DIMINISH ACROSS THE AREA WITH DRY CONDITIONS BY THURSDAY AFTERNOON/EVENING. && .LONG TERM...FRIDAY THROUGH TUESDAY ISSUED AT 251 AM MDT WED AUG 27 2014 PROGRESSIVE NORTHERN STREAM FLOW WILL CONTINUE THROUGH THE PERIOD. TWO MAIN SYSTEMS EXPECTED TO AFFECT THE REGION IN THE PERIOD...A WEAK NORTHERN STREAM TROUGH FRIDAY...AND A MORE ROBUST LONGWAVE UPPER TROUGH SAT NIGHT INTO MONDAY. FORECAST MODELS IN GOOD AGREEMENT PER WAVE AMPLITUDE AND TRACK. HOWEVER...SOME SUBSTANTIAL DIFFERENCES BEGIN TO EMERGE IN THE SUNDAY NIGHT INTO MONDAY PERIOD BETWEEN THE ECMWF AND GFS...MAINLY THE HANDLING OF THE NW CONUS SOUTHERN PERIPHERY EJECTING IMPULSE. THE ECMWF HAS A SOUTHERN BIAS TO THE SYSTEM WITH THE BULK OF LSA PASSING THROUGH THE FA AS OPPOSED TO A MORE NORTHERN TRACK IN THE GFS...WHICH IS ALSO FASTER. THE ECMWF SOLUTION WOULD SUPPORT BETTER CHANCES FOR RAIN IN THE FA HOWEVER MOISTURE LIMITATIONS MAY PRECLUDE ANY PRECIP TOTALS THEN. RETAINED PREV POPS FOR FRIDAY AFTERNOON...WITH A SLIGHT UPTICK AND EXPANSION OF SLIGHT MENTION. FORECAST MODELS CONTINUE TO INDICATE A SFC TROUGH STALLING ACROSS THE SW HALF FRIDAY...WITH A PASSING UPPER LEVEL IMPULSE. SUFFICIENT LL MOISTURE ND RESULTING CAPE WOULD BE CONDUCIVE FOR CONVECTION IN THE AFTERNOON...ESP OVER THE BLACK HILLS. OTHERWISE...A MORE IMPRESSIVE UPPER LEVEL TROUGH WILL PUSH OUT OF THE NE PAC AND INTO THE NORTHERN PLAINS...SUPPORTING INCREASING LSA SAT NIGHT THROUGH SUNDAY NIGHT. BETTER SFC CYCLONE DEVELOPMENT LOOKS TO REMAIN WELL EAST OF THE REGION...SUPPORTING MORE ELEVATED/CONVECTIVE CHANCES BEHIND THE SFC TROUGH RATHER THAN WIDESPREAD DEFORMATION RAINS. HENCE...KEPT POPS IN THE SLIGHT TO LOW CHANCE CAT FOR NOW...ESP AS DEEPER MOISTURE WILL SHIFT QUICKLY EAST OUT OF THE REGION. KEPT MOST OF THE REGION DRY MONDAY THROUGH TUES...WITH UPPER LEVEL RIDGING COMMENCING AND DRY PROFILES. SEASONAL TEMPS EXPECTED IN MOST OF THE PERIOD...WITH BELOW NORMAL TEMPS /5-10 DEGREES/ EXPECTED MONDAY AND PERHAPS TUES BEHIND SUNDAY/S COLD FRONT...ESP NW AREAS. && .AVIATION...FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY NIGHT ISSUED AT 251 AM MDT WED AUG 27 2014 SCT-ISOLD SHOWERS/THUNDERSTORMS EXPECTED ACROSS THE SOUTHERN HALF THROUGH MOST OF THE PERIOD AS A SERIES OF IMPULSES CROSS THE REGION. LCL MVFR/IFR CONDS EXP WITH HEAVIER PRECIPITATION. ADDITIONALLY...IFR CIGS WILL SPREAD NORTH ACROSS SW AND SCENTRAL SD THIS MORNING...WITH CIGS TRENDING TO MVFR LATE MORNING/EARLY AFTERNOON. CIGS MAY LINGER THROUGH THE PERIOD THERE. WINDS WILL VEER SE AROUND KRAP THIS AFTERNOON...WITH THE POTENTIAL FOR MVFR CIGS TO SPREAD INTO THE RAP TERMINAL THEN. HAVE HINTED AT THIS IN THE TAF. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...MLS LONG TERM...JC AVIATION...JC
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
203 PM CDT WED AUG 27 2014 .UPDATE... 18Z TAF DISCUSSION. && .AVIATION... ISO -SHRA WILL DEVELOP NEAR CKV THIS AFTERNOON. OTHERWISE...VFR CONDITIONS ARE ANTICIPATED AT AIRPORTS THROUGH THIS EVENING BEFORE FOG BRINGS MVFR/IFR VIS TO CKV/CSV AFTER MIDNIGHT. LIGHT NORTHEAST WINDS ARE ANTICIPATED THROUGHOUT THE TAF PERIOD. SHAMBURGER && .PREV DISCUSSION... /ISSUED 1016 AM CDT WED AUG 27 2014/ UPDATE... LATEST VISIBLE SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES WITH CUMULUS DEVELOPMENT UNDERWAY ACROSS CENTRAL PARTS OF THE MID STATE AND THE PLATEAU ALONG WITH SOME CIRRUS MOVING ACROSS. TEMPERATURES RISING QUICKLY AND CURRENTLY IN THE UPPER 70S EAST TO MID 80S ELSEWHERE. DEWPOINT CURRENTLY IN THE MID 60S TO MID 70S WILL MIX OUT SOME OVER EASTERN HALF OF THE AREA THIS AFTERNOON...BUT STILL ANTICIPATING A HOT AND HUMID DAY ON TAP FOR MOST LOCATIONS AND NO CHANGES WERE MADE TO TEMPS. STILL CANNOT RULE OUT AN ISOLATED SHOWER OR STORM OVER NORTHWEST ZONES WHERE DEEPER MOISTURE IS PRESENT...AND ADJUSTED POPS SOMEWHAT BASED ON THE LATEST HRRR MODEL. SHAMBURGER PREV DISCUSSION... /ISSUED 526 AM CDT WED AUG 27 2014/ UPDATE...FOR 12Z TAFS. AVIATION... MORELESS A REPEAT OF THE PAST FEW DAYS WITH CONVECTION TODAY MAINLY ACROSS THE NORTHWEST. EARLY MORNING FOG EXPECTED TO CLEAR 14-15Z LEAVING VFR CONDITIONS THROUGHOUT THE DAY AND INTO THE EVENING. FOG IS EXPECTED TO REDEVELOP LATE EVENING CSV...THEN AGAIN OVERNIGHT CKV/BNA. CONDITIONS LIKELY TO DROP BRIEFLY TO IFR CSV/CKV 06-13Z THU. PREV DISCUSSION... /ISSUED 345 AM CDT WED AUG 27 2014 UPPER RIDGING IN CONTROL ACROSS THE SOUTHEASTERN U.S.. AT THE SFC...HIGH PRESSURE IS LOCATED OVER THE GREAT LAKES REGION. THIS FEATURE IS LARGE ENOUGH TO CONTROL OUR WEATHER AND A LIGHT NE FLOW IS EXPECTED TODAY. ON THURSDAY...THE UPPER HIGH WILL BUILD SE TOWARD NRN FL WITH A RIDGE AXIS EXTENDING NW ACROSS TN. ALL OF THIS RIDGING WILL ACT TO IMPEDE ANY LOW LEVEL BOUNDARY INFLUENCE. CONVECTIVE PARAMETERS SHOW VERY LITTLE CHANCE OF CONVECTION FOR TODAY. BUT...WE DO SEE AN INCREASE IN CAPE VALUES ON THU AFTERNOON...BUT THIS IS ACROSS THE NORTH ONLY. SO...WILL INCLUDE A SLIGHT CHANCE OF AFT SHOWERS AND TSTMS. FURTHERMORE...THE HRRR IS SHOWING SOME AFT DEVELOPMENT ACROSS THE KY AREA THIS AFTERNOON. MID/UPPER LEVEL FLOW PATTERN DICTATES THAT THIS ACTIVITY WILL MOVE SE. THEREFORE...MAY NEED TO INCLUDE A SLIGHT CHANCE OF AFT SHOWERS AND TSTMS ACROSS THE NORTH FOR TODAY AS WELL. WILL LEAN TOWARD ISC AND CURRENT GRIDS FOR A FINAL DECISION. FOR THE NEAR TERM TEMPS...ABOVE NORMAL TEMPS EXPECTED WITH HIGHS GENERALLY IN THE LOWER 90S...LOWS LOWER 70S...COOLER PLATEAU. IN THE EXT FCST...SHORTWAVE TO DEVELOP OVER THE NATIONS INTERIOR THIS WEEKEND. WIND FLOW PATTERN WILL THEN EVOLVE INTO A MORE UNIFORM SOUTHERLY FLOW WHICH WILL BRING INCREASING MOISTURE LEVELS BACK ACROSS THE AREA. THOUGH THE SHORTWAVE WILL LIFT OFF TO THE NE AND NOT DIRECTLY IMPACT THE MID STATE...CONVECTIVE CONDITIONS WILL BECOME MORE FAVORABLE. THE GFS ACTUALLY EMPHASIZES AN UPSTREAM IMPULSE IN CLOSE PROXIMITY FOR SAT NT. SO...ALL IN ALL... POPS WILL BE ON THE INCREASE FOR THE SAT THROUGH MON PERIOD. THEREAFTER...W-E UPPER RIDGING WILL REDEVELOP ACROSS THE DEEP SOUTH WITH POPS ON THE DOWNSWING. FOR THE EXT TEMPS...ABOVE NORMAL VALUES TO CONTINUE EVEN THOUGH RIDGING BACKS OFF DURING THE SAT THROUGH MON PERIOD. HEIGHTS REMAIN ON THE ELEVATED SIDE. 21 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1016 AM CDT WED AUG 27 2014 .UPDATE... LATEST VISIBLE SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES WITH CUMULUS DEVELOPMENT UNDERWAY ACROSS CENTRAL PARTS OF THE MID STATE AND THE PLATEAU ALONG WITH SOME CIRRUS MOVING ACROSS. TEMPERATURES RISING QUICKLY AND CURRENTLY IN THE UPPER 70S EAST TO MID 80S ELSEWHERE. DEWPOINT CURRENTLY IN THE MID 60S TO MID 70S WILL MIX OUT SOME OVER EASTERN HALF OF THE AREA THIS AFTERNOON...BUT STILL ANTICIPATING A HOT AND HUMID DAY ON TAP FOR MOST LOCATIONS AND NO CHANGES WERE MADE TO TEMPS. STILL CANNOT RULE OUT AN ISOLATED SHOWER OR STORM OVER NORTHWEST ZONES WHERE DEEPER MOISTURE IS PRESENT...AND ADJUSTED POPS SOMEWHAT BASED ON THE LATEST HRRR MODEL. SHAMBURGER && .PREV DISCUSSION... /ISSUED 526 AM CDT WED AUG 27 2014/ UPDATE...FOR 12Z TAFS. AVIATION... MORELESS A REPEAT OF THE PAST FEW DAYS WITH CONVECTION TODAY MAINLY ACROSS THE NORTHWEST. EARLY MORNING FOG EXPECTED TO CLEAR 14-15Z LEAVING VFR CONDITIONS THROUGHOUT THE DAY AND INTO THE EVENING. FOG IS EXPECTED TO REDEVELOP LATE EVENING CSV...THEN AGAIN OVERNIGHT CKV/BNA. CONDITIONS LIKELY TO DROP BRIEFLY TO IFR CSV/CKV 06-13Z THU. PREV DISCUSSION... /ISSUED 345 AM CDT WED AUG 27 2014 UPPER RIDGING IN CONTROL ACROSS THE SOUTHEASTERN U.S.. AT THE SFC...HIGH PRESSURE IS LOCATED OVER THE GREAT LAKES REGION. THIS FEATURE IS LARGE ENOUGH TO CONTROL OUR WEATHER AND A LIGHT NE FLOW IS EXPECTED TODAY. ON THURSDAY...THE UPPER HIGH WILL BUILD SE TOWARD NRN FL WITH A RIDGE AXIS EXTENDING NW ACROSS TN. ALL OF THIS RIDGING WILL ACT TO IMPEDE ANY LOW LEVEL BOUNDARY INFLUENCE. CONVECTIVE PARAMETERS SHOW VERY LITTLE CHANCE OF CONVECTION FOR TODAY. BUT...WE DO SEE AN INCREASE IN CAPE VALUES ON THU AFTERNOON...BUT THIS IS ACROSS THE NORTH ONLY. SO...WILL INCLUDE A SLIGHT CHANCE OF AFT SHOWERS AND TSTMS. FURTHERMORE...THE HRRR IS SHOWING SOME AFT DEVELOPMENT ACROSS THE KY AREA THIS AFTERNOON. MID/UPPER LEVEL FLOW PATTERN DICTATES THAT THIS ACTIVITY WILL MOVE SE. THEREFORE...MAY NEED TO INCLUDE A SLIGHT CHANCE OF AFT SHOWERS AND TSTMS ACROSS THE NORTH FOR TODAY AS WELL. WILL LEAN TOWARD ISC AND CURRENT GRIDS FOR A FINAL DECISION. FOR THE NEAR TERM TEMPS...ABOVE NORMAL TEMPS EXPECTED WITH HIGHS GENERALLY IN THE LOWER 90S...LOWS LOWER 70S...COOLER PLATEAU. IN THE EXT FCST...SHORTWAVE TO DEVELOP OVER THE NATIONS INTERIOR THIS WEEKEND. WIND FLOW PATTERN WILL THEN EVOLVE INTO A MORE UNIFORM SOUTHERLY FLOW WHICH WILL BRING INCREASING MOISTURE LEVELS BACK ACROSS THE AREA. THOUGH THE SHORTWAVE WILL LIFT OFF TO THE NE AND NOT DIRECTLY IMPACT THE MID STATE...CONVECTIVE CONDITIONS WILL BECOME MORE FAVORABLE. THE GFS ACTUALLY EMPHASIZES AN UPSTREAM IMPULSE IN CLOSE PROXIMITY FOR SAT NT. SO...ALL IN ALL... POPS WILL BE ON THE INCREASE FOR THE SAT THROUGH MON PERIOD. THEREAFTER...W-E UPPER RIDGING WILL REDEVELOP ACROSS THE DEEP SOUTH WITH POPS ON THE DOWNSWING. FOR THE EXT TEMPS...ABOVE NORMAL VALUES TO CONTINUE EVEN THOUGH RIDGING BACKS OFF DURING THE SAT THROUGH MON PERIOD. HEIGHTS REMAIN ON THE ELEVATED SIDE. 21 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
345 AM CDT WED AUG 27 2014 .DISCUSSION... UPPER RIDGING IN CONTROL ACROSS THE SOUTHEASTERN U.S.. AT THE SFC...HIGH PRESSURE IS LOCATED OVER THE GREAT LAKES REGION. THIS FEATURE IS LARGE ENOUGH TO CONTROL OUR WEATHER AND A LIGHT NE FLOW IS EXPECTED TODAY. ON THURSDAY...THE UPPER HIGH WILL BUILD SE TOWARD NRN FL WITH A RIDGE AXIS EXTENDING NW ACROSS TN. ALL OF THIS RIDGING WILL ACT TO IMPEDE ANY LOW LEVEL BOUNDARY INFLUENCE. CONVECTIVE PARAMETERS SHOW VERY LITTLE CHANCE OF CONVECTION FOR TODAY. BUT...WE DO SEE AN INCREASE IN CAPE VALUES ON THU AFTERNOON...BUT THIS IS ACROSS THE NORTH ONLY. SO...WILL INCLUDE A SLIGHT CHANCE OF AFT SHOWERS AND TSTMS. FURTHERMORE...THE HRRR IS SHOWING SOME AFT DEVELOPMENT ACROSS THE KY AREA THIS AFTERNOON. MID/UPPER LEVEL FLOW PATTERN DICTATES THAT THIS ACTIVITY WILL MOVE SE. THEREFORE...MAY NEED TO INCLUDE A SLIGHT CHANCE OF AFT SHOWERS AND TSTMS ACROSS THE NORTH FOR TODAY AS WELL. WILL LEAN TOWARD ISC AND CURRENT GRIDS FOR A FINAL DECISION. FOR THE NEAR TERM TEMPS...ABOVE NORMAL TEMPS EXPECTED WITH HIGHS GENERALLY IN THE LOWER 90S...LOWS LOWER 70S...COOLER PLATEAU. IN THE EXT FCST...SHORTWAVE TO DEVELOP OVER THE NATIONS INTERIOR THIS WEEKEND. WIND FLOW PATTERN WILL THEN EVOLVE INTO A MORE UNIFORM SOUTHERLY FLOW WHICH WILL BRING INCREASING MOISTURE LEVELS BACK ACROSS THE AREA. THOUGH THE SHORTWAVE WILL LIFT OFF TO THE NE AND NOT DIRECTLY IMPACT THE MID STATE...CONVECTIVE CONDITIONS WILL BECOME MORE FAVORABLE. THE GFS ACTUALLY EMPHASIZES AN UPSTREAM IMPULSE IN CLOSE PROXIMITY FOR SAT NT. SO...ALL IN ALL... POPS WILL BE ON THE INCREASE FOR THE SAT THROUGH MON PERIOD. THEREAFTER...W-E UPPER RIDGING WILL REDEVELOP ACROSS THE DEEP SOUTH WITH POPS ON THE DOWNSWING. FOR THE EXT TEMPS...ABOVE NORMAL VALUES TO CONTINUE EVEN THOUGH RIDGING BACKS OFF DURING THE SAT THROUGH MON PERIOD. HEIGHTS REMAIN ON THE ELEVATED SIDE. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 92 72 94 72 / 05 05 20 05 CLARKSVILLE 93 69 94 69 / 10 05 20 10 CROSSVILLE 86 65 89 67 / 05 0 20 05 COLUMBIA 92 70 94 70 / 0 05 10 05 LAWRENCEBURG 92 66 94 67 / 0 05 10 05 WAVERLY 93 69 94 69 / 10 05 10 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
646 PM CDT THU AUG 28 2014 .AVIATION... /00Z TAFS/ Scattered showers and thunderstorms over west and northwest Texas are slowly moving east this evening. A few of these may enter our western and northwestern counties, through early tonight. Have more uncertainty on whether any of our TAF sites will be affected. KABI and KSJT may potentially be affected, and will monitor radar trends for possible update and inclusion of TSRA. Otherwise, high cloud cover from the aforementioned convection will overspread West Central Texas this evening and early tonight. On Friday, scattered showers and thunderstorms will be possible, mainly during the afternoon and across the Big Country area north of Interstate 20. Patchy low cloud development is possible toward morning across some of our southern counties, and have a scattered layer included at KSOA and KJCT. Southeast winds will veer to the south overnight and continue on Friday morning. && .PREV DISCUSSION... /ISSUED 340 PM CDT THU AUG 28 2014/ SHORT TERM... (Tonight and Friday) Rain chances for the next 24 hours continue to look more promising. The latest WSR-88D data indicate showers and thunderstorms are developing across the Big Country. The RUC indicates this activity will continue to develop and spread into mainly our northwestern counties during the next 6 hours. Overnight tonight, the NAM fragments the QPF into small areas across mainly our northwestern counties. Given the uncertainty across our southeastern counties, slight chance PoPs still look good there. Elsewhere, and especially north of our Interstate 20 corridor, chance PoPs look best. As the upper trough axis pushes farther east tomorrow, the better rain chances will expand south and include more of our southern counties. The main thunderstorm threats for the next 24 hours are deadly lightning and flash flooding from locally heavy rainfall. Huber LONG TERM... (Friday night to Thursday) While the upper trough will be east of the region Friday night and Saturday, a weakly capped atmosphere will remain. Therefore, isolated, mainly afternoon and evening showers and thunderstorms will continue to be possible. The upper ridge strengthens Sunday, however, with hot and dry conditions expected through next week. Highs are expected mainly in the mid 90s. 04 && .PRELIMINARY POINT TEMPS/POPS... Abilene 72 93 72 96 73 / 40 30 20 20 10 San Angelo 73 94 72 96 74 / 30 30 20 20 10 Junction 73 93 73 95 74 / 20 20 20 20 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
321 PM CDT WED AUG 27 2014 .SHORT TERM... WV SHOWS THE UPPER LEVEL LOW OF INTEREST CURRENTLY POSITIONED OVER UT WITH EASTERN NM/WESTERN TX SITTING UNDER A PLUME OF MONSOONAL MOISTURE THAT IS BEING SUCKED INTO THE LOW. A FEW SHORTWAVES MAKING THEIR WAY ACROSS NM ARE NOTICED AHEAD OF THE MAIN LOW. THESE SHORTWAVES WILL TRIGGER OUR FIRST ROUND OF PRECIP LATER TONIGHT. POPS THROUGH TOMORROW MORNING REMAIN MOSTLY UNCHANGED WITH THE EXCEPTION OF CHANCE MENTION HAVING BEEN EXPANDED SLIGHTLY EASTWARD. WHILE THE MAIN SOURCE OF LIFT WILL BE TO OUR WEST...UPPER LEVEL FLOW OVERHEAD WILL REMAIN SLIGHTLY DIFFLUENT. AS HAS BEEN SEEN THE PAST SEVERAL DAYS...IT DOES NOT TAKE MUCH LIFT TO FIRE SHALLOW CONVECTION. ONE NOTE OF INTEREST IS THE 15Z HRRR DEVELOPING A LINE SHALLOW CONVECTION ALONG THE EDGE OF THE CAPROCK THIS AFTERNOON WHERE WEAK SURFACE CONVERGENCE IS OBSERVED. CHANCES WILL INCREASE AFTER 12Z TOMORROW MORNING AS AN UPPER LEVEL JET BEGINS TO FORM JUST TO OUR NORTHEAST PUTTING A MAJORITY OF OUR EASTERN ZONES IN THE ENTRANCE REGION OF THE JET HELPING PROMOTE DIVERGENCE. DUE TO INCREASING DIVERGENCE THROUGH THE AFTERNOON COUPLED WITH PWATS APPROACHING 2 INCHES SUB-LIKELY POPS HAVE BEEN INSERTED ACROSS MUCH OF THE ROLLING PLAINS. ONE ISSUE THAT WILL NEED TO BE WATCHED IS THE POSSIBILITY OF LOCALIZED FLOODING DUE TO TRAINING THUNDERSTORMS. THE SURFACE FRONT WILL APPROACH OUR NORTHWESTERN ZONES EARLY TOMORROW MORNING BUT SHOULD NOT MAKE IT FAR INTO THE FA WITH THE FARTHEST EXTENT BEING ALONG A LINE FROM DIMMIT TO BROWNFIELD. CAA WILL BE RATHER WEAK WITH THIS FRONT WITH TEMPS MODERATING ONLY A FEW DEGREES FROM WHAT WE WILL SEE TODAY. HIGHS ACROSS THE WESTERN SOUTH PLAINS AND SOUTHWESTERN TX PANHANDLE SHOULD BE IN THE UPPER 80S/LOW 90S. WITH THE FRONT BEING WEAK COMPRESSIONAL HEATING SHOULD NOT BE TOO HUGE OF AN ISSUE WHICH WILL PREVENT HIGHS FROM MELTING THE PAVEMENT OFF OF ROADS. && .LONG TERM... THE UA TROUGH NOTED ACROSS NERN UTAH LATE THIS AFTN...IS PROGGED TO CONTINUE TO PROGRESS EWRD TO ACROSS THE CNTRL/SRN PLAINS BY TOMORROW NIGHT. A PERSISTENT UPSLOPE SFC REGIME WILL ALLOW FOR PWATS TO INCREASE ON THE ORDER OF 1.25-1.70 INCHES ACROSS THE FA WHICH COUPLED WITH INCREASED LARGE SCALE ASCENT...WILL AID IN CONTINUED CHANCES FOR SHOWER AND THUNDERSTORM DEVELOPMENT TOMORROW NIGHT. FURTHERMORE...A COLD FRONT ASSOCIATED WITH THE AFOREMENTIONED UA TROUGH MAY IMPINGE ON THE FAR SRN TX PANHANDLE...NRN SOUTH PLAINS AND NRN ROLLING PLAINS DURING THE DAY FRIDAY AS HINTED AT BY MODEL SOLUTIONS...WHICH COULD AID IN CONTINUAL PRECIP CHANCES. HOWEVER...UL SUPPORT WILL COMMENCE TO DECLINE AS THE UA TROUGH EXITS EAST OF THE REGION BY FRIDAY AFTN. NONETHELESS...THE PRESENCE OF THE FRONT IS ENOUGH TO MAINTAIN MENTIONABLE POPS FRIDAY...WITH HIGHEST POPS ACROSS THE ROLLING PLAINS NEAREST TO THE DEPARTING LARGE SCALE ASCENT. THE POTENTIAL FOR STORMS TO BECOME SEVERE APPEARS LOW AS A BIT OF A VEERING WIND PROFILE LACKS SIGNIFICANT WIND SPEEDS ALOFT...HOWEVER LOCALIZED FLOODING CAN NOT BE RULED DUE TO THE ANTICIPATED ABOVE NORMAL PWATS. BY SATURDAY...RATHER LOW AMPLITUDE RIDGING WILL PROGRESS EWRD ACROSS THE CNTRL CONUS...THOUGH IT IS INTERESTING TO NOTE THAT MODEL SOLUTIONS DISPLAY LIGHT QPF SIGNALS ACROSS THE CWA. WITH THE PREVIOUSLY MENTIONED COLD FRONT WASHED OUT/RETREATED NORTH...THE LIGHT PRECIP APPEARS TO BE CAUSED BY AN EMBEDDED IMPULSE IN THE FLOW ALOFT. WILL GO AHEAD AND INSERT 10-14 POPS FOR NOW. A NEARBY SFC TROUGH WILL PROMOTE BREEZY SRLY SFC WINDS FOR THE WEEKEND...WHILST A BROAD UA LOW AFFECTING SRN CANADA/NORTHERN ROCKIES WILL CAUSE FLOW ALOFT TO BECOME ZONAL ACROSS THE SRN PLAINS. AS THE SAID UA SYSTEM TRANSLATES EAST ACROSS THE NRN PLAINS...IT WILL PUSH A BACKDOOR COLD FRONT TO ACROSS THE FAR SERN TX PANHANDLE MONDAY...WHICH COULD SERVE AS A PRECIP FOCUS. WILL HOLD ON TO SILENT POPS BEYOND FRIDAY ATTM...THOUGH WILL NEED TO KEEP AN EYE ON LATER MODEL RUNS AND SEE IF THIS TRENDS HOLDS FOR NEXT WEEK. WITH THE ANTICIPATED RAINFALL AND INCREASED CLOUDINESS EXPECTED EARLY IN THE EXTENDED PERIOD...TEMPS WILL COOL INTO THE UPPER 80S-LOWER 90S ON FRIDAY. TEMPS WILL QUICKLY REBOUND BACK INTO THE 90S BY THE WEEKEND...AND POSSIBLY NEAR LOWER TRIPLE DIGITS OFF THE CAPROCK BY EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 62 88 59 86 60 / 40 30 30 20 20 TULIA 66 88 62 86 63 / 40 40 40 30 20 PLAINVIEW 66 89 63 87 64 / 30 40 40 20 20 LEVELLAND 66 91 64 88 64 / 30 40 40 20 20 LUBBOCK 69 91 67 91 67 / 30 40 40 30 20 DENVER CITY 66 93 65 90 65 / 30 40 40 20 20 BROWNFIELD 67 93 65 90 65 / 30 40 40 20 20 CHILDRESS 73 92 69 90 70 / 30 50 50 30 30 SPUR 68 94 66 91 67 / 20 50 50 30 30 ASPERMONT 72 97 70 94 70 / 20 50 50 30 30 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 51/29
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1225 PM CDT WED AUG 27 2014 .AVIATION... /18Z TAFS/ ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP WITHIN AN AXIS OF MOISTURE EITHER SIDE OF THE I-35 CORRIDOR BETWEEN 18Z AND 20Z THIS AFTERNOON. MOISTURE IS A LITTLE RICHER NEAR WACO FROM GOES SOUNDER ANALYSIS AND CORRELATES WELL BEING CLOSER TO THE LOW PRESSURE SYSTEM OFFSHORE FROM KCRP. ONLY CHANGE ON THIS FORECAST WILL BE TO INCLUDED VCSH AT WACO THROUGH EARLY EVENING. OTHERWISE...WILL PLAY THE WAITING GAME FOR ANY AMENDMENTS REGARDING ISOLATED CONVECTIVE ACTIVITY AND THE DFW METRO AREA WHERE CONFIDENCE IS NOT QUITE AS HIGH. EAST WINDS WILL RANGE BETWEEN 6-10 KTS THIS AFTERNOON. WINDS WILL BECOME SOUTH OR SOUTH-SOUTHEAST NEAR 10 KTS LATER ON THURSDAY MORNING. 05/ && .UPDATE... TODAY WILL BE A WARM DAY WITH ISOLATED SHOWERS AND THUNDERSTORMS ACROSS THE REGION THROUGH THE EARLY EVENING HOURS. TEMPERATURES TODAY WILL BE VERY SIMILAR TO YESTERDAYS HIGH TEMPERATURES. THE 12Z FWD SOUNDING THIS MORNING MEASURED A PWAT OF 1.66 INCHES...INDICATIVE OF DECENT MOISTURE ACROSS THE REGION. HOWEVER...UNDER THE INFLUENCE OF EASTERLY FLOW FROM THE SURFACE TO MID LEVELS OF THE ATMOSPHERE...BOTH THE NAM AND RAP INDICATE DRIER AIR WILL MOVE INTO THE REGION THIS AFTERNOON FROM THE EAST. THIS TREND IS SUPPORTIVE BY THE GOES PW SOUNDER WHICH INDICATES DRIER AIR IS CURRENTLY TO OUR EAST. THE NAM AND RAP INDICATE THE DRIEST AIR...WITH PWATS CLOSER TO 1-1.25 INCHES...WILL MOVE ACROSS OUR SOUTHEAST COUNTIES THIS AFTERNOON AND CONTINUE A WESTWARD TRACK THIS EVENING AND TONIGHT. WHILE DRIER AIR MAY ARRIVE IN OUR EASTERN AND SOUTHEASTERN COUNTIES LATER TODAY...THE REST OF THE REGION WILL REMAIN MOIST AND HUMID. SINCE THE RIDGE HAS BEEN WEAKENED...EXPECT ISOLATED CONVECTION TO OCCUR TODAY AND HAVE EXPANDED THE MENTION OF ISOLATED SHOWERS/STORMS ACROSS ALL OF NORTH AND CENTRAL TEXAS. IT WILL BE MORE DIFFICULT FOR CONVECTION TO DEVELOP IN OUR SOUTHEAST ZONES WHEN THE DRIER AIR ARRIVES LATER BUT UNTIL THEN THERE IS STILL A CHANCE FOR ISOLATED ACTIVITY. GUSTY WINDS AND BRIEF HEAVY RAINFALL WILL OCCUR WITH ANY CONVECTION THIS AFTERNOON. 82/JLD && .PREV DISCUSSION... /ISSUED 324 AM CDT WED AUG 27 2014/ A WEAK TUTT WAS LOCATED JUST EAST OF CORPUS CHRISTI THIS MORNING AND HAS RESULTED IN AN INCREASE IN PWATS AND INSTABILITY ACROSS THE REGION. ISOLATED SHOWERS/THUNDERSTORMS ARE POSSIBLE OVER THE WESTERN AND SOUTHERN COUNTIES THIS AFTERNOON AND EVENING. UPSTREAM...UPPER TROUGH OVER THE GREAT BASIN WILL MOVE OUT OF THE CENTRAL ROCKIES ON THURSDAY NIGHT AND ACROSS THE GREAT PLAINS BY LATE FRIDAY NIGHT. SHORT WAVE FORCING FOR CONVECTION WILL BE BEST ACROSS AREAS TO THE NORTH BUT IT WILL BE ADEQUATE FOR SCATTERED SHOWERS/THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS AS THE SOUTHERN END OF THE TROUGH MOVES ACROSS THE REGION. WE WILL START OUT WITH LOW CHANCE POPS THURSDAY AFTERNOON/EVENING...THEN INCREASE POPS WEST TO EAST ON FRIDAY AS THE UPPER TROUGH NEARS. ALTHOUGH SHEAR WILL BE LOW ON FRIDAY...CAPE WILL BE ADEQUATE FOR SOME STRONG STORMS WITH GUSTY WINDS...AND LOCALLY HEAVY RAINFALL DUE TO PWATS NEAR 2 INCHES. AS THE UPPER TROUGH MOVES INTO THE MIDWEST AND EAST TEXAS OVER THE WEEKEND...WE WILL BE TRIMMING POPS WEST TO EAST TO MATCH ITS POSITION. BY SUNDAY...POPS WILL BE LIMITED TO 20S OVER THE FAR EASTERN COUNTIES. DRY WEATHER WILL SETTLE IN FOR SUNDAY NIGHT THROUGH TUESDAY. TEMPERATURES WILL BE RESPONDING TO SLIGHTLY LOWER HEIGHTS ALOFT DUE TO THE TUTT AND THE PASSAGE OF THE UPPER TROUGH LATER IN THE WEEK. HIGHS ON THURSDAY WILL WILL BE A DEGREE OR TWO COOLER THAN THOSE EXPECTED TODAY...AND ABOUT 5 DEGREES COOLER ON FRIDAY DUE TO ADDITIONAL CLOUDS AND SCATTERED CONVECTION. EXPECTING HIGHS TO CREEP UP A FEW DEGREES ON SUNDAY WITH GENERALLY MID 90S THE FIRST OF NEXT WEEK. LOW TEMPS WILL NOT CHANGE MUCH....BUT FRIDAYS CONVECTION COULD RESULT IN SOME LOWER 70S OUT WEST AND ALONG THE RED RIVER ON SATURDAY MORNING. LOOKING AHEAD...HIGH PRESSURE ALOFT WILL BE BUILDING BACK OVER THE REGION THE FIRST WEEK OF SEPTEMBER WITH THE WESTERLIES REMAINING OVER THE NORTHERN PART OF THE COUNTRY. AS A RESULT...THERE DOES NOT SEEM TO BE ANOTHER OPPORTUNITY FOR COOLER WEATHER OR RAIN/STORMS UNTIL AFTER THE 10TH OF SEPTEMBER. 75 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 98 77 97 78 93 / 10 10 10 20 50 WACO, TX 99 74 97 76 93 / 10 10 20 10 40 PARIS, TX 94 71 95 73 92 / 10 10 10 20 50 DENTON, TX 96 74 96 76 92 / 10 10 10 20 50 MCKINNEY, TX 96 72 96 75 92 / 10 10 10 20 50 DALLAS, TX 98 77 97 78 92 / 10 10 10 20 50 TERRELL, TX 97 75 96 75 93 / 10 10 10 20 50 CORSICANA, TX 96 76 97 75 93 / 10 10 10 10 40 TEMPLE, TX 98 73 96 75 93 / 10 10 20 20 50 MINERAL WELLS, TX 99 72 98 74 93 / 10 10 10 20 50 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 05/82
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1041 AM CDT WED AUG 27 2014 .UPDATE... TODAY WILL BE A WARM DAY WITH ISOLATED SHOWERS AND THUNDERSTORMS ACROSS THE REGION THROUGH THE EARLY EVENING HOURS. TEMPERATURES TODAY WILL BE VERY SIMILAR TO YESTERDAYS HIGH TEMPERATURES. THE 12Z FWD SOUNDING THIS MORNING MEASURED A PWAT OF 1.66 INCHES...INDICATIVE OF DECENT MOISTURE ACROSS THE REGION. HOWEVER...UNDER THE INFLUENCE OF EASTERLY FLOW FROM THE SURFACE TO MID LEVELS OF THE ATMOSPHERE...BOTH THE NAM AND RAP INDICATE DRIER AIR WILL MOVE INTO THE REGION THIS AFTERNOON FROM THE EAST. THIS TREND IS SUPPORTIVE BY THE GOES PW SOUNDER WHICH INDICATES DRIER AIR IS CURRENTLY TO OUR EAST. THE NAM AND RAP INDICATE THE DRIEST AIR...WITH PWATS CLOSER TO 1-1.25 INCHES...WILL MOVE ACROSS OUR SOUTHEAST COUNTIES THIS AFTERNOON AND CONTINUE A WESTWARD TRACK THIS EVENING AND TONIGHT. WHILE DRIER AIR MAY ARRIVE IN OUR EASTERN AND SOUTHEASTERN COUNTIES LATER TODAY...THE REST OF THE REGION WILL REMAIN MOIST AND HUMID. SINCE THE RIDGE HAS BEEN WEAKENED...EXPECT ISOLATED CONVECTION TO OCCUR TODAY AND HAVE EXPANDED THE MENTION OF ISOLATED SHOWERS/STORMS ACROSS ALL OF NORTH AND CENTRAL TEXAS. IT WILL BE MORE DIFFICULT FOR CONVECTION TO DEVELOP IN OUR SOUTHEAST ZONES WHEN THE DRIER AIR ARRIVES LATER BUT UNTIL THEN THERE IS STILL A CHANCE FOR ISOLATED ACTIVITY. GUSTY WINDS AND BRIEF HEAVY RAINFALL WILL OCCUR WITH ANY CONVECTION THIS AFTERNOON. 82/JLD && .AVIATION... /ISSUED 603 AM CDT WED AUG 27 2014/ VFR WILL PREVAIL WITH JUST SOME FAIR WX CUMULUS. LIGHT SOUTHEAST WINDS WILL BECOME EASTERLY BY MIDDAY WITH SPEEDS NEAR 10KT. WINDS WILL DIMINISH AND BECOME MORE SOUTHERLY TONIGHT. && .PREV DISCUSSION... /ISSUED 324 AM CDT WED AUG 27 2014/ A WEAK TUTT WAS LOCATED JUST EAST OF CORPUS CHRISTI THIS MORNING AND HAS RESULTED IN AN INCREASE IN PWATS AND INSTABILITY ACROSS THE REGION. ISOLATED SHOWERS/THUNDERSTORMS ARE POSSIBLE OVER THE WESTERN AND SOUTHERN COUNTIES THIS AFTERNOON AND EVENING. UPSTREAM...UPPER TROUGH OVER THE GREAT BASIN WILL MOVE OUT OF THE CENTRAL ROCKIES ON THURSDAY NIGHT AND ACROSS THE GREAT PLAINS BY LATE FRIDAY NIGHT. SHORT WAVE FORCING FOR CONVECTION WILL BE BEST ACROSS AREAS TO THE NORTH BUT IT WILL BE ADEQUATE FOR SCATTERED SHOWERS/THUNDERSTORMS ACROSS NORTH AND CENTRAL TEXAS AS THE SOUTHERN END OF THE TROUGH MOVES ACROSS THE REGION. WE WILL START OUT WITH LOW CHANCE POPS THURSDAY AFTERNOON/EVENING...THEN INCREASE POPS WEST TO EAST ON FRIDAY AS THE UPPER TROUGH NEARS. ALTHOUGH SHEAR WILL BE LOW ON FRIDAY...CAPE WILL BE ADEQUATE FOR SOME STRONG STORMS WITH GUSTY WINDS...AND LOCALLY HEAVY RAINFALL DUE TO PWATS NEAR 2 INCHES. AS THE UPPER TROUGH MOVES INTO THE MIDWEST AND EAST TEXAS OVER THE WEEKEND...WE WILL BE TRIMMING POPS WEST TO EAST TO MATCH ITS POSITION. BY SUNDAY...POPS WILL BE LIMITED TO 20S OVER THE FAR EASTERN COUNTIES. DRY WEATHER WILL SETTLE IN FOR SUNDAY NIGHT THROUGH TUESDAY. TEMPERATURES WILL BE RESPONDING TO SLIGHTLY LOWER HEIGHTS ALOFT DUE TO THE TUTT AND THE PASSAGE OF THE UPPER TROUGH LATER IN THE WEEK. HIGHS ON THURSDAY WILL WILL BE A DEGREE OR TWO COOLER THAN THOSE EXPECTED TODAY...AND ABOUT 5 DEGREES COOLER ON FRIDAY DUE TO ADDITIONAL CLOUDS AND SCATTERED CONVECTION. EXPECTING HIGHS TO CREEP UP A FEW DEGREES ON SUNDAY WITH GENERALLY MID 90S THE FIRST OF NEXT WEEK. LOW TEMPS WILL NOT CHANGE MUCH....BUT FRIDAYS CONVECTION COULD RESULT IN SOME LOWER 70S OUT WEST AND ALONG THE RED RIVER ON SATURDAY MORNING. LOOKING AHEAD...HIGH PRESSURE ALOFT WILL BE BUILDING BACK OVER THE REGION THE FIRST WEEK OF SEPTEMBER WITH THE WESTERLIES REMAINING OVER THE NORTHERN PART OF THE COUNTRY. AS A RESULT...THERE DOES NOT SEEM TO BE ANOTHER OPPORTUNITY FOR COOLER WEATHER OR RAIN/STORMS UNTIL AFTER THE 10TH OF SEPTEMBER. 75 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 98 77 97 78 93 / 10 10 10 20 50 WACO, TX 99 74 97 76 93 / 10 10 20 10 40 PARIS, TX 94 71 95 73 92 / 10 10 10 20 50 DENTON, TX 96 74 96 76 92 / 10 10 10 20 50 MCKINNEY, TX 96 72 96 75 92 / 10 10 10 20 50 DALLAS, TX 98 77 97 78 92 / 10 10 10 20 50 TERRELL, TX 97 75 96 75 93 / 10 10 10 20 50 CORSICANA, TX 96 76 97 75 93 / 10 10 10 10 40 TEMPLE, TX 98 73 96 75 93 / 10 10 20 20 50 MINERAL WELLS, TX 99 72 98 74 93 / 10 10 10 20 50 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 05/82
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1237 AM CDT WED AUG 27 2014 .DISCUSSION...UPDATED FOR 06Z AVIATION. && .AVIATION...MOISTURE WILL CONTINUE TO INCREASE ACROSS THE GULF WATERS AND COASTAL LOCATIONS. APPROACHING UPPER DISTURBANCE WILL RESULT IN SHOWERS AND THUNDERSTORMS MAINLY ACROSS THE COASTAL BEND AND HAVE INCLUDED VCSH/VCTS REMARKS AT CRP/VCT. WILL PREVAIL OR TEMPO SHRA/TSRA IN LATER FORECASTS IF CONFIDENCE INCREASES. GENERALLY VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD... BUT LOWER CIGS/VSBYS WILL BE POSSIBLE IF SHOWERS/STORMS DIRECTLY IMPACT A TAF SITE. && .PREV DISCUSSION... /ISSUED 943 PM CDT TUE AUG 26 2014/ DISCUSSION...SATELLITE IMAGERY SHOWS THE MID LEVEL LOW OVER THE NORTHERN GULF OF MEXICO SOUTH OF LAKE CHARLES. THE SURFACE TROUGH AXIS EXTENDS ACROSS THE GULF OF MEXICO FROM THE YUCATAN CHANNEL NORTHWEST TO THE UPPER TEXAS COAST. 00Z CRP SOUNDING INDICATED AN INCREASE IN MOISTURE OVER THE REGION UP TO 2 INCHES...WHILE GOES SOUNDER SHOWS HIGHER MOISTURE OVER THE NORTHWEST GULF OF MEXICO NEAR THE MID LEVEL LOW. THIS MOISTURE WILL BE MOVING INTO THE COASTAL WATERS OVERNIGHT. LATEST RUNS OF NAM/GFS SHOWED AN INCREASE IN LOW LEVEL CONVERGENCE OVER THE COASTAL WATERS LATE TONIGHT INTO WEDNESDAY MORNING. HI RES MODELS FROM TEXAS TECH WRF AND HRRR SHOWED AREAS OF CONVECTION INCREASING OVER THE COASTAL WATERS LATER TONIGHT INTO WEDNESDAY. RAISED POPS TO LIKELY CATEGORY FOR THE OFFSHORE WATERS LATE TONIGHT THROUGH WEDNESDAY. NORTHEAST WINDS MAY APPROACH SCEC LEVELS OVER THE GULF WATERS ON WEDNESDAY. PREV DISCUSSION... /ISSUED 636 PM CDT TUE AUG 26 2014/ DISCUSSION...UPDATED FOR 00Z AVIATION. AVIATION...SHOWERS MAINLY ENDING THIS EVENING...BUT HAVE A FEW REMAINING BETWEEN ALI AND COT. THESE WILL NOT AFFECT TAF SITES FOR THE REST OF TONIGHT. OVERNIGHT SHOULD HAVE MAINLY VFR CONDITIONS...WILL SEE SOME LOW LEVEL CU DEVELOP...BUT DONT EXPECT A CIG CONDITION. WITH MORE MOISTURE BUILDING IN AND AN APPROACHING UPPER DISTURBANCE...WILL CONTINUE SHOWER/STORM CHANCES TOMORROW FOR CRP/VCT TAF SITES. ALI WOULD HAVE SMALLER CHANCE...TOO SMALL TO INCLUDE IN TAFS THIS SOON. PREV DISCUSSION... /ISSUED 352 PM CDT TUE AUG 26 2014/ SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...EXPECTING ACTIVITY OVER INLAND AREAS TO END AROUND OR BEFORE SUNSET...WITH ACTIVITY PICKING UP AGAIN OVER THE EASTERN AREAS/GULF WATERS OVERNIGHT. HOWEVER...ACTIVITY MAY LINGER A BIT MORE OVER THE NORTHEAST BUT SHOULD EVENTUALLY DIE OFF BEFORE MIDNIGHT...WITH SHOWERS DEVELOPING OVER THE GULF WATERS OVERNIGHT. THEN...SHOULD BE SEEING AN INCREASE IN CONVECTION SPREADING FARTHER INLAND ON WEDNESDAY...WITH THE BETTER CHANCES MORE TOWARD THE NORTHEAST. AM GOING TO GO WITH ISOLATED TO SCATTERED CONVECTION AS DO EXPECT CONVECTION WEDNESDAY OVER MOST INLAND AREAS (OBVIOUSLY THE SCATTERED CONVECTION CLOSER TO THE COAST AND ISOLATED FARTHER WEST). WILL LIKELY HAVE A BRIEF LULL IN CONVECTION IN THE EVENING...THEN START UP AGAIN DURING THE LATE EVENING/OVERNIGHT HOURS WEDNESDAY NIGHT OVER THE COASTAL AREAS. WITH INCREASE IN MOISTURE...SHOULD SEE A SLIGHT WARM-UP IN OVERNIGHT LOWS TONIGHT AND WEDNESDAY NIGHT...BUT COOLER TEMPERATURES WEDNESDAY DUE TO CLOUDS AND RAIN-COOLED AREAS. MARINE (TONIGHT THROUGH WEDNESDAY NIGHT)...BELOW SCEC CONDITIONS EXPECTED THROUGH THE PERIOD. SCATTERED SHOWERS/THUNDERSTORMS BECOME MORE PREVALENT THROUGH THE PERIOD...AS THE TROUGH APPROACHES THE AREA BRINGING IN DEEPER TROPICAL MOISTURE. WINDS AND SEAS HIGHER IN THUNDERSTORMS. LONG TERM (THURSDAY THROUGH TUESDAY)...WITH RESPECT TO THE GFS ENSEMBLE MEAN...THE UPPER TROUGH/LOW IS EXPECTED TO MEANDER OVER THE CWA/MSA THURSDAY THEN DISSIPATE FRIDAY AS A PROGRESSIVE SYSTEM MOVES ACRS THE SRN PLAINS/NRN AND CNTRL TX. SELECT GFS DETERMINISTIC SOUNDINGS SUGGEST COPIOUS MSTR/VERY HIGH PWAT VALUES OVER THE CWA/MSA THURSDAY THROUGH SUNDAY. YET...GFS ENSEMBLE MEAN SUGGEST THAT AN UPPER RIDGE WILL BUILD OVER THE CWA/MSA BEGINNING SUNDAY/ MONDAY. THUS...EXPECT SCT CONVECTION OVER THE CWA/MSA (OWING TO COPIOUS MSTR AND TO UPPER/SFC FORCING) WITH LOCALLY HEAVY RAINFALL (EFFICIENT RAINFALL PRODUCTION) THURSDAY/FRIDAY...A DECREASE IN COVERAGE SATURDAY/SUNDAY...AND NO PCPN MONDAY/TUESDAY. ANTICIPATE LOWER MAX TEMPS THURSDAY THROUGH SATURDAY WITH A STEADY INCREASE AFTERWARD. ANTICIPATE MAX HEAT INDEX VALUES 105-109F MONDAY/TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 95 78 91 78 91 / 40 30 40 30 40 VICTORIA 95 77 92 76 92 / 50 30 40 30 40 LAREDO 102 80 100 80 99 / 10 10 20 20 20 ALICE 98 76 95 77 94 / 30 20 30 30 30 ROCKPORT 91 80 88 80 88 / 50 40 40 30 40 COTULLA 100 76 100 76 98 / 10 10 20 20 20 KINGSVILLE 97 76 94 77 93 / 40 20 40 30 40 NAVY CORPUS 90 81 87 80 88 / 50 40 40 30 40 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1107 PM EDT THU AUG 28 2014 .SYNOPSIS... A WEAK COLD FRONT WILL STALL ACROSS NORTH CAROLINA LATE TONIGHT... THEN HEAD BACK NORTH AGAIN FOR FRIDAY INTO SATURDAY. A STRONGER UPPER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS TO CLOSE OUT THE LABOR DAY WEEKEND. && .NEAR TERM /THROUGH FRIDAY/... AS OF 1100 PM EDT THURSDAY... BACKDOOR FRONT CURRENTLY HUNG UP OVER SOUTHSIDE VA AND NW NC...ALONG A UKF-MWK-MTV-LYH-FVX LINE. DEWPOINTS ALONG AND SOUTH OF THE FRONT ARE IN THE LOWER 70S. NORTH OF THE FRONT DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S. FRONT NOT EXPECTED TO MAKE MUCH PROGRESS OVERNIGHT...MAY DRIFT TO ALONG THE VA/NC BORDER OR JUST INTO NORTHERN NC. THERE HAS BEEN AN ONGOING CLUSTER OF SHRA/TSRA NEAR BUCKINGHAM AND FARMVILLE VCNTY OF THE FRONTAL BOUNDARY...RADAR ESTIMATING UPWARDS OF AN INCH OF RAIN FALLING OVER PARTS OF SOUTHERN BUCKINGHAM COUNTY DURING THE EVENING. THE HRRR MODEL SHOWS A GRADUAL DRIFT OF THIS PRECIP TOWARD I-95 COORIDOR DURING THE OVERNIGHT WITH POTENTIAL REDEVELOPMENT OF SHRA VCNTY OF THE FRONT FROM CHARLOTTE COURT HOUSE EAST DURING THE OVERNIGHT. ASIDE FOR THE SHOWER THREAT ALONG THE FRONT...NOT MUCH GOING ON WEATHERWISE. THE NORTHERN/WESTERN CWA...FROM THE NC MTNS INTO THE NRV OF VA...AND FROM THE THE GREENBRIER VALLEY OF WV EAST ALONG THE I-64 CORRIDOR INTO CENTRAL VA WILL RESIDE NORTH OF THE FRONT OVERNIGHT. WITH DEWPOINTS IN THE 50S...TEMPERATURES SHOULD BE ABOUT 10 DEGREES COOLER THAN FOLKS SOUTH OF THE FRONTAL BOUNDARY WHERE READINGS WILL BE CLOSER TO 70. OVERNIGHT...SOME OF THE MODELS...ESP THE NAM...INDICATE INCREASING LOW LEVEL CLOUD COVER PER DEVELOPMENT OF EASTERLY LOW LEVEL WINDS VCNTY OF THE FRONT...THE RESULTANT UPSLOPE FLOW INTO THE BLUE RIDGE RESULTING IN CLOUD DEVELOPMENT LATE TONIGHT. ATTM WILL CONTINUE TO ADVERTISE SOME STRATUS IN THE MORNING...BUT PREFER TO KEEP OVERALL SKY CONDITIONS TONED DOWN FROM THE NAM BUT THINK AREAS OVER THE FOOTHILLS AND PIEDMONT COULD BE MOSTLY CLOUDY IN THE MORNING. PATCHY FOG WILL FORM IN THE MOUNTAIN VALLEYS LATE TONIGHT WHERE SKIES SHOULD STAY MOSTLY CLEAR...PARTLY CLOUDY AT WORST. LOWS TONIGHT WILL BE A LITTLE COOLER IN THE NORTH PER DRIER AIR WITH READINGS IN THE MID TO UPPER 50S...WHILE TEMPERATURES WILL BE CLOSER TO THE 65-70 DEGREE RANG IN THE SOUTH. FRIDAY...FRONT STARTS WORKING BACK NORTH ACROSS US. MODELS ARE AGREEMENT THAT LIFT AND MOISTURE WILL BE LIMITED OVER US BUT CANNOT RULE OUT ISOLATED SHRA/TSRA IN THE REGION. BEST LIFT WILL BE ACROSS THE SW VA MTNS TOWARD TN...SO HAVE 30ISH POPS HERE. ANOTHER AREA IS OVER THE RALEIGH-DURHAM AREA AND EAST...SO MAY SEE SOME SCATTERED STORMS TOWARD YANCEYVILLE. SE WINDS WILL BE KEEPING TEMPS FROM GETTING TOO HIGH...PLUS DEALING WITH POTENTIAL LOW CLOUDS INTO MORNING OVER THE EAST. HIGHS WILL MAY WORK OUT TO BE HOMOGENEOUS ACROSS THE ENTIRE CWA OUTSIDE THE HIGHER ELEVATIONS WITH LOWER TO MID 80S. SE FLOW DOWNSLOPE WARMING MAY INCREASE TEMPS OVER THE MTN EMPIRE BUT STORMS FIRING UP IN THE AFTERNOON SHOULD PREVENT IT FROM TOPPING OUT CLOSE TO THE MAV GUIDANCE OF UPPER 80S. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... AS OF 310 PM EDT THURSDAY... UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A SRN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL STREAK OVER THE GULF COAST STATES AND ACROSS THE WRN SLOPES OF THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SSE FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN THE EAST...MAINLY FROM THE ERN WV PANHANDLE SOUTHEAST TOWARD THE TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST WITH MID 80S WEST. SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER FRIDAY EVENING STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT LEAST SLIGHT CHANCE INTO THE MTNS LATE. SUNDAY LOOKS ACTIVE AS THE SHORTWAVE SHIFTS ACROSS KY INTO NRN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR IN THE WEST WHERE A FEW STORMS COULD PRODUCE GUSTY WINDS. HIGHS SUNDAY WILL RANGE FROM THE UPPER 70S MTNS TO UPPER 80S SE. OVERALL...LABOR DAY WEEKEND LOOKING VERY WARM/HOT/HUMID. SATURDAY NOT TOO BAD RAIN WISE...BUT STAY COOL WHILE DRINKING PLENTY OF WATER IF OUTDOORS. SUNDAY APPEARS POOR FOR OUTDOOR ACTIVITIES. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE GULF COAST STATES BY THE END OF THE FORECAST PERIOD. SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO AND THROUGH THE GREAT LAKES INTO NEW ENGLAND. HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED OVER THE AREA. GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME. PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64 BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR. PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER 80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... AS OF 730 PM EDT THURSDAY... CLEAR SKIES ACROSS THE TAF SITES THIS EVENING. HIGH CONFIDENCE OF VFR CONDITIONS THROUGH MUCH OF THE EVENING AND OVERNIGHT. EXPECT SOME PATCHY FOG AGAIN FRIDAY MORNING. MVFR/IFR CONDITIONS MAY EXIST FOR A FEW HOURS AT BLF/LWB/BCB...WHILE THE REMAINING TAF LOCATIONS SHOULD REMAIN VFR THROUGH THE ENTIRE TAF PERIOD. PATCHY FOG ACROSS THE MOUNTAINS WILL QUICKLY BURN OFF AFTER SUNRISE RETURNING THOSE LOCATIONS TO VFR FOR THE REMAINDER OF THE PERIOD. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE AFTERNOON/EARLY EVENING AS A WARM FRONT LIFTS NORTH...HOWEVER THE CONVECTION IS EXPECTED TO BE WIDELY SCATTERED SO THERE IS CURRENTLY NO MENTION OF THUNDER OR PRECIP IN THE TAFS. THE WINDS WILL SHIFT TO AN EASTERLY DIRECTION EARLY IN THE DAY ON FRIDAY AND EVENTUALLY BECOME SOUTHERLY BY LATE IN THE TAF PERIOD...WITH WIND SPEEDS REMAINING LIGHT. EXTENDED DISCUSSION... WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION AGAIN ON SATURDAY MAINLY DURING THE LATE AFTERNOON AND EARLY EVENING. SHOULD ONE OF THESE STORMS DEVELOP NEAR A TAF LOCATION IT COULD RESULT IN A BRIEF PERIOD OF SUB VFR CONDITIONS. AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND MONDAY. SHOWER COVERAGE SUNDAY/MONDAY IS EXPECTED TO BE MORE WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY. && .EQUIPMENT... AS OF 100 PM EDT THURSDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...REMAINS OUT OF SERVICE. A PART HAS BEEN ORDERED. REPAIRS WILL BE DONE THIS FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/WP NEAR TERM...PM/WP SHORT TERM...WP LONG TERM...WERT AVIATION...AMS/CF/WP EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
904 PM CDT THU AUG 28 2014 .UPDATE... IT/S BEEN EXCEPTIONALLY QUIET ACROSS SOUTHERN WISCONSIN THIS EVENING AND THAT TREND SHOULD CONTINUE THROUGH MUCH OF THE NIGHT...POSSIBLY UNTIL FRIDAY AFTERNOON. FOR TONIGHT...THE AREA REMAINS UNDER A RATHER PRONOUNCED UPPER LEVEL RIDGE AXIS. THERE WAS SOME WEAK SHORT WAVE ENERGY MOVING THROUGH IT LATE THIS AFTERNOON...BUT FOR THE MOST PART THE RIDGE IS INTACT. THE SHOWERS NORTH OF MILWAUKEE AND MADISON HAVE BEEN ASSOCIATED WITH SOME 850MB WARM AIR ADVECTION THAT WILL ONLY LIFT FARTHER NORTHEAST WITH TIME. THE HRRR AND THE 18Z NAM TRY TO FIRE SOMETHING UP OVER NW IL/NE IA AND LIFT IT NORTH INTO THE AREA. THERE IS CONVECTION CURRENTLY FIRING OVER PORTIONS OF SOUTHWEST IOWA IN A REGION OF UNINHIBITED DEEP CAPE. THE PROBLEM IS THAT CAPE DROPS OFF TO NOTHING OVER NORTHEAST IOWA...SO IT WOULD BE A STRUGGLE FOR ANYTHING TO SURVIVE UP IN OUR MORE UNFAVORABLE AIRMASS. PLUS...OUR SOUTHEAST LOW LEVEL FLOW IS KEEPING A DRY FEED OF AIR INTO THE FORECAST AREA. WILL KEEP POPS CHCY LATER TONIGHT...BUT CONFIDENCE IS LOW THAT WE WILL SEE ANYTHING. THE UPPER RIDGE BREAKS DOWN ON FRIDAY AND THE ATMOSPHERE DESTABILIZES WITH CAPE BUILDING. THAT SHOULD RESULT IN A ROUND OF THUNDERSTORMS...BUT THAT WOULD HAVE TO WAIT UNTIL THE AFTERNOON/EVENING HOURS. && .AVIATION/06Z TAFS/... THE CHANCE FOR STORMS WAS TRIMMED SIGNIFICANTLY AT THE 00Z ISSUANCE GIVEN THE LOW CONFIDENCE THAT ANYTHING WOULD REACH THE AIRPORT LOCATIONS BEFORE FRIDAY AFTERNOON. FORCING IS WEAK OVERNIGHT INTO FRIDAY MORNING. WE/LL HAVE TO WATCH IF ANYTHING DEVELOPS OVER PORTIONS OF EASTERN IOWA AND NORTHWEST IL OVERNIGHT...AS THIS WOULD LIKELY ROLL NORTH ACROSS THE AREA LATE TONIGHT INTO FRIDAY MORNING. THE CHANCE FOR STORMS INCREASES FRIDAY AFTERNOON AND EVENING WITH BUILDING INSTABILITY AND A VERY MOIST AIRMASS. THE CURRENT FORECAST IS GENERALLY VFR THROUGH THE TAF PERIOD. HOWEVER...THERE IS CONCERN THAT AN AREA OF MVFR CIGS OVER SOUTHWEST WISCONSIN MAY GET INTO MADISON BEFORE IT LIFTS NORTH OF SOUTHERN WISCONSIN. THE THREAT FOR THOSE LOWER CLOUDS WOULD BE BETWEEN 06-12Z FRI. BEYOND THAT...ALL SITES SHOULD STAY VFR. ANY STORMS THAT DEVELOP LATER IN THE TAF PERIOD COULD ALWAYS BRING BRIEF LOWER CONDITIONS. && .PREV DISCUSSION... /ISSUED 318 PM CDT THU AUG 28 2014/ SHORT TERM... TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM. AREA OF RAIN SHOWERS CURRENTLY MOVING EAST NORTHEAST INTO THE FAR WESTERN COUNTIES AND WEAKENING. THIS IS BEING DRIVEN BY REMNANT 500 MB MESOSCALE CONVECTIVE VORTEX. MESOSCALE MODELS ARE SHOWING THIS AREA OF SHOWERS MOVING EAST NORTHEAST THROUGH MOST OF THE AREA THROUGH THE LATE AFTERNOON HOURS...CONTINUING TO WEAKEN AS IT MOVES INTO DRIER AIR. THERE IS A MORE ORGANIZED AREA OF RAIN SHOWERS IN NORTHERN ILLINOIS...WHICH COULD ALSO MOVE INTO THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. LITTLE TO NO ELEVATED CAPE SEEN ON AREA FORECAST SOUNDINGS...SO PULLED MENTION OF THUNDER LATE THIS AFTERNOON. HAVE HIGHEST POPS WEST WITH LOWER POPS IN THE EAST UNTIL 00Z FRIDAY. MAIN 850 MB LOW LEVEL JET NOSE WILL FOCUS TO THE NORTHWEST AND NORTH OF THE AREA THIS EVENING AND OVERNIGHT...WHICH SHOULD KEEP THE STRONGEST UPWARD VERTICAL MOTION AND MOISTURE CONVERGENCE IN THAT AREA. SYNOPTIC AND MESOSCALE MODELS ARE IN GENERAL AGREEMENT WITH THIS OCCURRING. STILL SHOULD SEE SOME SHOWERS AND STORMS WITHIN FOCUSED 850 MB WARM AIR ADVECTION ZONE AND PASSING WARM FRONT TONIGHT INTO EARLY FRIDAY MORNING. HIGHEST POPS ARE IN THE NORTHERN HALF OF THE AREA...CLOSEST TO BEST UPWARD VERTICAL MOTION. LEFT CHANCE POPS IN THE SOUTH. AREA FORECAST SOUNDINGS DO SHOW ELEVATED CAPE SLOWLY INCREASING THROUGH THE NIGHT. PRECIPITABLE WATER VALUES REMAIN IN THE 1.80 TO 1.90 INCH RANGE...BUT CORFIDI VECTORS REMAIN ON THE HIGH SIDE. SO...JUST LOCALIZED HEAVY RAIN IS ANTICIPATED. MODELS SHOWING AREA GETTING INTO WARM SECTOR AIR ON FRIDAY...AS WARM FRONT MOVES NORTH OF THE AREA. AGAIN...BEST UPWARD VERTICAL MOTION WILL BE FOCUSED NORTH AND WEST OF THE AREA...SO THERE MAY BE A LULL IN THE PRECIPITATION. LEFT CHANCE POPS GOING ON FRIDAY FOR NOW. STILL...NO CAPPING WITH 1500 TO 2000 PLUS J/KG MEAN LAYER CAPE AND WEAK TO MODEST DEEP LAYER SHEAR SUGGEST SOME STRONG STORMS POSSIBLE IF THEY CAN GET GOING. PRECIPITABLE WATER VALUES AROUND 1.50 TO 1.75 INCHES WITH WEAK CORFIDI VECTORS...SO LOCALIZED HEAVY RAINFALL IS AGAIN A POSSIBILITY. SOUTH WINDS AND SOME SUN IN THE AFTERNOON SHOULD BRING HIGHS INTO THE LOWER TO MID 80S ACROSS MOST OF THE AREA. FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE IS HIGH THE MID/UPPER LEVEL SHORTWAVE PUSHES INTO WISCONSIN. SOMEWHAT OF A COUPLED JET STRUCTURE FRIDAY NIGHT...BUT THE JET MAX IS RATHER WEAK AT 50 TO 60 KNOTS. UPPER LEVEL DIVERGENCE IS MODERATE DURING THE EVENING TO AROUND MIDNIGHT BEFORE WEAKENING. 700 MB UPWARD MOTION IS RATHER STRONG AS IT APPROACHES SOUTH CENTRAL WISCONSIN BUT WEAKENS AS IT MOVES ACROSS THE SOUTH. 700 MB RH INCREASES... BUT IS NOT QUITE SATURATED. THE 850/700 MB SPEED MAX IS ACROSS THE UPPER GREAT LAKES...WITH SOUTHERN WISCONSIN IN THE ENTRANCE REGION. 850 MB DEWPOINTS ARE AROUND 16 CELSIUS DURING THE EARLY EVENING...BUT THEN DECREASES TO AROUND 11 CELSIUS BY SUNRISE. THE SURFACE COLD FRONT REACHES SOUTH CENTRAL WISCONSIN FRIDAY NIGHT AND EXITS THE SOUTHEAST SATURDAY MORNING. EVENING ZERO TO 1 KM CAPE VALUES AROUND 2000 JOULES/KG DURING THE EARLY EVENING... DECREASES TO AROUND 600 JOULES/KG OVER THE SOUTHEAST LATE. THE HIGHER CAPE IS THEN TO THE SOUTH ON SATURDAY WITH WEAK HIGH PRESSURE BUILDING INTO WISCONSIN. THE NAM/GFS AND 00Z ECMWF BRING HEAVY PRECIPITATION INTO SOUTH CENTRAL WISCONSIN FRIDAY EVENING...WITH DIMINISHING MAINLY MODERATE AMOUNTS OVER THE SOUTHEAST LATER SATURDAY NIGHT. THE LOCAL SEVERE WEATHER PARAMETER INCREASES TO AROUND 70 PCT OVER SOUTH CENTRAL WISCONSIN FRIDAY EVENING AND AROUND 70 PCT OVER THE SOUTHEAST OVERNIGHT. THE NSHARP FORECAST SOUNDINGS GIVES A SEVERE POTENTIAL SOUTH CENTRAL AND MARGINAL SEVERE POTENTIAL SOUTHEAST. SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE IS HIGH THE MAIN SHORTWAVE MOVES EAST BUT A SECONDARY WEAKER SHORTWAVE MOVES INTO WISCONSIN LATE SATURDAY NIGHT AND SUNDAY MORNING AHEAD OF THE NEXT STRONG SHORTWAVE MOVING INTO THE PLAINS. UPPER DIVERGENCE ACROSS SOUTHERN WISCONSIN IS WEAK...AS IS THE 700 MB UPWARD MOTION. THE NAM DOES HAVE SCATTERED MAINLY LIGHT PRECIPITATION SATURDAY NIGHT AND SUNDAY MORNING. LONG TERM... SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE IS HIGH THE GFS AND ECMWF TAKES A STRONG SHORTWAVE ACROSS WISCONSIN DURING THIS PERIOD. THE GFS/ECMWF AND DGEX BRING A BAND OF HEAVY RAIN INTO SOUTH CENTRAL WISCONSIN LATER SUNDAY NIGHT...AND ACROSS THE SOUTHEAST SUNDAY MORNING. THE GFS IS A LITTLE QUICKER THAN THE 12Z ECMWF. MONDAY NIGHT AND TUESDAY...FORECAST CONFIDENCE IS HIGH THE GFS AND ECMWF TAKES A SECOND SHORTWAVE ACROSS WISCONSIN TUESDAY. THE GFS/ECMWF AND DGEX HAVE JUST LIGHT PRECIPITATION...MAINLY MORE NORTH TOWARD CENTRAL AND NORTHERN WISCONSIN. WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE IS HIGH THE GFS AND ECMWF HAVE A ZONAL FLOW ACROSS THE U.S./CANADIAN BORDER AREA AS ANOTHER TROUGH PUSHES ACROSS THE NORTHWEST U.S. WEAK HIGH PRESSURE MOVES ACROSS THE GREAT LAKES WEDNESDAY WITH A WARM FRONT AND PRECIPITATION MOVING INTO SOUTHERN WISCONSIN WEDNESDAY NIGHT AND THURSDAY ON THE 12Z ECMWF BUT IS DRY ON THE 12Z GFS. AVIATION/00Z TAFS/... EXPECT BAND OF SHOWERS TO PUSH EAST NORTHEAST THROUGH MADISON AND POSSIBLY THE EASTERN TAF SITES BETWEEN 21Z THURSDAY AND 00Z FRIDAY. MVFR CEILINGS ARE POSSIBLE. EAST SOUTHEAST WINDS WILL LINGER DURING THIS TIME. MAIN AREA OF SHOWERS AND THUNDERSTORMS WILL REMAIN NORTH AND WEST OF TAF SITES TONIGHT INTO EARLY FRIDAY MORNING. STILL SHOULD SEE SOME SHOWERS AND STORMS AT TIMES...AS WARM FRONT MOVES NORTH THROUGH THE AREA. FOR NOW...WILL USE VICINITY THUNDER WORDING IN TAFS DUE TO LOW CONFIDENCE IN SPECIFIC TIMING. MVFR CEILINGS AND MVFR/IFR VISIBILITIES ARE POSSIBLE IN ANY STORMS. MAY BE A PERIOD OF QUIET WEATHER LATER FRIDAY MORNING INTO THE AFTERNOON...AS BEST PRECIPITATION AREA WILL REMAIN TO THE NORTH OF THE AREA. SOME UNCERTAINTY HERE WITH THE PRECIPITATION TRENDS...THUS THE VICINITY THUNDER WORDING CONTINUES. SOUTHEAST WINDS TONIGHT WILL SHIFT TO THE SOUTH FRIDAY AND INCREASE IN MAGNITUDE. MARINE... EAST SOUTHEAST WINDS TONIGHT WILL INCREASE AND BECOME SOUTHEAST TO SOUTH ON FRIDAY ACROSS THE NEARSHORE WATERS. WINDS WILL INCREASE INTO THE 10 TO 20 KNOT RANGE ON FRIDAY. THIS WILL BUILD WAVES TO 2 TO 4 FEET TOWARD SHEBOYGAN. WINDS AND WAVES WILL GRADUALLY SUBSIDE FRIDAY NIGHT. BEACHES... INCREASING SOUTHEAST TO SOUTH WINDS OF 10 TO 20 KNOTS LATER TONIGHT AND FRIDAY SHOULD BUILD WAVES TO 2 TO 4 FEET ALONG BEACHES IN SHEBOYGAN COUNTY. THUS...A MODERATE SWIM RISK IS EXPECTED TO OCCUR LATER TONIGHT INTO FRIDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DAVIS TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD FRIDAY NIGHT THROUGH THURSDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
637 PM CDT THU AUG 28 2014 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 329 PM CDT THU AUG 28 2014 MAIN FOCUS FOR THE NEXT 24 TO 48 HOURS IS ON THE HEAVY RAINFALL POTENTIAL AS A FEW ROUNDS OF STORMS LIFT THROUGH THE UPPER MISSISSIPPI RIVER VALLEY. AS OF MID AFTERNOON...WATER VAPOR IMAGERY OVERLAID WITH RAP 500MB RAP HEIGHTS SHOWED THE SHORTWAVE TROUGH PUSHING OFF THE COLORADO ROCKIES WITH WEAK IMPULSES LIFTING THROUGH THE CENTRAL PLAINS TOWARD THE UPPER MIDWEST. ONE SUCH WAVE IS BRINGING THE SHIELD OF MAINLY RAIN SHOWERS THIS AFTERNOON...WHILE ANOTHER ONE IS NOTED NEAR THE TX PANHANDLE INTO SOUTHERN KANSAS. THIS ONE...ALONG WITH THE MAIN TROUGH...WILL BE OUR PLAYER FOR FRIDAY AFTERNOON AND EVENING. THE SURFACE HIGH PRESSURE ANCHORED OVER THE GREAT LAKES KEPT FLOW OF DRIER AIR...LIMITING THE FORWARD PROGRESS OF RAIN SHIELD. A LOT OF THE MOISTURE WENT INTO SATURATION...AND COMBINED WITH THE WEAKENING LLJ MOISTURE TRANSPORT FROM THIS MORNING...THE HEAVIER RAINFALL DID NOT MATERIALIZE. WITH THAT SAID...THE ENVIRONMENT WILL BEGIN TO BECOME MORE FAVORABLE TONIGHT AND RECENT 1-HR RAINFALL TOTALS HAVE BEEN GENERALLY 0.1 TO 0.2 INCH...WITH SOME ISOLATED 0.3-0.5 AMOUNTS. VERY LITTLE INSTABILITY FOUND ACROSS THE AREA WHICH IS KEEPING ACTIVITY AS SHOWERS/RAIN. WENT AHEAD AND LIMITED THUNDER CHANCES TO ISOLATED/SCATTERED THROUGH THE OVERNIGHT HOURS...ESPECIALLY MN/WI AREAS. IT WILL BE MORE STEADY RAINFALL. AS THE CURRENT SHIELD OF RAIN LIFTS NORTHEAST...EXPECTING THE BACK EDGES TO FILL IN SOME KEEPING THE HIGHER POPS IN PLACE THROUGH THE OVERNIGHT. THE TIMING OF ANY SPECIFIC UPPER LEVEL WAVES...WITH CONFLICTING STRENGTH IN MOISTURE TRANSPORT AND SURFACE FOCUS...LENDS A BIT LOWER CONFIDENCE IN WHERE HEAVIEST RAINFALL WILL FALL. WHAT HAS HIGHER CONFIDENCE IS THAT THE ATMOSPHERE SHOULD BETTER PRIMED FOR EFFICIENT RAIN PRODUCERS. NO CHANGES TO THE IDEA THAT PWATS ARE HIGH...WARM CLOUD DEPTHS ARE ABOVE 4 KM...AND THERE IS A CONTINUOUS FLOW OF MOISTURE STREAMING IN FROM THE SOUTHWEST IN ADVANCE OF THE SHORTWAVE. PERUSAL OF 28.12Z MODELS SHOW SIGNALS FOR ANOTHER IMPULSE TO SPARK CONVECTION OVERNIGHT ACROSS WESTERN INTO SOUTHWEST IOWA. THIS WOULD LIFT THROUGH NORTHEAST IOWA AND SOUTHEAST MINNESOTA EARLY MORNING. AFTER THE MORNING LLJ WEAKENS...THERE SEEMS TO NOT BE ANOTHER KICKER UNTIL LATE FRIDAY AFTERNOON AND EVENING. AS SUCH...THE LATE MORNING AND EARLY AFTERNOON HOURS COULD END UP DRIER...AND HAVE TRIED TO REFLECT THIS THINKING IN THE HOURLY POPS. THE MORE SIGNIFICANT WAVE ARRIVES FRIDAY AFTERNOON THROUGH THE EARLY MORNING HOURS SATURDAY. FINALLY THE MAIN SHORTWAVE TROUGH ENERGY WILL BE FELT...AND WITH A GOOD FEED OF MOISTURE TRANSPORT AND WARM AIR ADVECTION...THERE SHOULD BE WIDESPREAD SHOWERS AND ISOLATED/EMBEDDED THUNDERSTORMS THROUGHOUT FROM LATE AFTERNOON ONWARD. ALTHOUGH THE FAVORABLE ATMOSPHERIC CONDITIONS WILL BE IN PLACE FOR HEAVY RAINFALL TOMORROW...THE LACK OF HIGHER RAINFALL TOTALS TODAY DAMPENS THE OVERALL FLASH FLOODING THREAT. RAINFALL TOTALS THROUGH SATURDAY HAVE BEEN TEMPERED A BIT...AND ARE MORE IN THE 1-2 INCH RANGE. A LOT OF THE AREA CAN TAKE THIS TYPE OF RAINFALL. OF COURSE LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE...BUT FEEL THE OVERALL THREAT IS REDUCED COMPARED TO THE THINKING IN THE PAST 24 HOURS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 PM CDT THU AUG 28 2014 THE MAIN FOCUS IN THE LONG TERM IS CENTERED ON THE THREAT FOR SEVERE WEATHER SUNDAY NIGHT INTO MONDAY. WITH THE HOLIDAY WEEKEND APPROACHING...AND WITH MANY FOLKS PLANNING OUTDOOR ACTIVITIES...IT IS THIS PERIOD THAT WARRANTS CLOSE WATCHING. IN THE UPPER LEVELS...THE 28.12Z GUIDANCE FOLLOWED THE PAST SEVERAL MODEL CYCLES IN SHOWING A DIGGING WESTERN CONUS LONGWAVE TROUGH APPROACHING THE NORTHERN PLAINS BY SUNDAY EVENING. 250MB JET DYNAMICS PUTS THE AREA IN A FAVORABLE RIGHT ENTRANCE REGION...AND THIS JET STRENGTHENS BETWEEN 00-06Z MONDAY. AT THE SURFACE...A COLD FRONT LOOKS LIKELY TO MOVE ACROSS MINNESOTA LATE SUNDAY NIGHT...REACHING THE MISSISSIPPI RIVER EARLY MONDAY MORNING. MUCAPE RANGES FROM 1500 TO 2000 J/KG ACROSS THE REGION LATE SUNDAY...WITH HEALTHY PROFILES AS NCAPE VALUES APPROACH 0.15. THIS IS AIDED BY 700-500MB LAPSE RATES AROUND 7.5C/KM. THE SHEAR ENVIRONMENT IS A BIT MUDDLED BETWEEN THE VARIOUS GUIDANCE...BUT OVERALL 0-3KM SHEAR VALUES RANGE FROM 20 TO 30 KTS. HODOGRAPHS SHOW SOME CURVATURE BUT A LOT OF THE SHEAR IS SPEED RELATED. OVERALL...THE CURRENT TIMING WOULD SUGGEST CONVECTION TO DEVELOP IN THE AFTERNOON ACROSS THE EASTERN DAKOTAS / WESTERN INTO CENTRAL MINNESOTA...POSSIBLY AS SUPERCELLS...THEN MERGE IN LINE SEGMENTS TOWARD THE WESTERN CWA IF MAINTAINED. THERE ARE STRONG MOISTURE TRANSPORT SIGNALS WITH HIGHER PWATS RETURNING...SO THERE COULD BE SOME HEALTHY RAIN PRODUCERS. THE MAIN LIMITING FACTOR WOULD BE STORM SPEED...WHICH SHOULD BE RATHER PROGRESSIVE. REGARDLESS...MAIN THREATS LOOK TO BE HEAVY RAIN...DAMAGING WINDS...AND LARGE HAIL. AT THIS TIME...GIVEN TIMING...WEST OF THE MS RIVER WOULD BE MORE FAVORABLE AND THIS LINES UP WELL WITH THE CURRENT DAY 4 OUTLOOK FROM THE SPC. OVERALL...WILL NEED TO WATCH THIS PERIOD. THE FRONT SLIDES INTO WESTERN WISCONSIN MONDAY MORNING...WHICH MAY ALLOW FOR ANOTHER ROUND OF DESTABILIZATION AND STRONG STORMS FOR OUR EASTERN AREAS MONDAY AFTERNOON. THAT IS A BIT MORE UNCERTAIN BUT IF THE SYSTEM SLOWS DOWN...WHICH SEEMS TO BE A TREND...THIS PERIOD MAY NEED TO BE WATCHED CLOSER. THE TUESDAY-THURSDAY PERIOD LOOKS TO FEATURE ZONAL UPPER LEVEL FLOW WITH THE POSSIBILITY OF A FEW RIPPLES SLIDING THROUGH. NOT MUCH CONSISTENCY IN THE MODEL RUNS TO ADD ANY DETAILS AT THIS POINT. LOTS OF WEATHER TO GET THROUGH UNTIL THEN. SLIGHT CHANCES WITH SEASONABLE TEMPERATURES LOOKS GOOD AT THIS POINT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 638 PM CDT THU AUG 28 2014 AREA OF MODERATE TO HEAVY RAIN WITH MVFR/IFR CEILINGS AND OCCASIONAL VISIBILITY REDUCTIONS AS LOW AS 1SM FROM KSYN TO KVOK AT 28.2330Z WILL LIFT NORTH AND EAST THIS EVENING...IMPACTING BOTH TAF AIRFIELDS OVER THE NEXT FEW HOURS. SHOULD SEE A SLOW TAPERING OF RAIN SHOWERS AFTER 29.06Z ALTHOUGH MODEL GUIDANCE SUGGESTS CEILINGS WILL REMAIN WELL BELOW 2000 FT AGL THROUGH THE NIGHT. CLOUD BASES WILL BE SLOW TO LIFT FRIDAY MORNING AND MAY REMAIN WITHIN THE MVFR/IFR RANGE THROUGH 29.18Z. WINDS FROM 5 TO 10 KTS WILL GRADUALLY SHIFT TO THE SOUTH THROUGH THE PERIOD. THUNDERSTORM CHANCES WILL BE HIGHLY DEPENDENT TOMORROW ON WHETHER ANY CLEARING OCCURS ALLOWING INSTABILITY TO BE REALIZED AS AN UPPER LEVEL DISTURBANCE APPROACHES THE UPPER MISSISSIPPI RIVER VALLEY. TO HEIGHTEN AWARENESS...ADDED 4 HOUR TEMPO GROUPS FRIDAY AFTERNOON FOR THUNDER POTENTIAL. && .HYDROLOGY...THROUGH SATURDAY MORNING ISSUED AT 329 PM CDT THU AUG 28 2014 WITH LESS THAN EXPECTED RAINFALL TODAY...OVERALL TOTALS THROUGH SATURDAY HAVE BEEN REDUCED TO THE 1.5 TO 2.5 INCH RANGE. THE SURGE IN EFFICIENT RAIN PRODUCING ATMOSPHERIC CONDITIONS...CHARACTERIZED BY WARM CLOUD DEPTHS 3.5 TO 4.0 KM...PWATS 1.5 TO 2.0 INCHES...AND LOWER 70F DEWPOINTS...WILL REMAIN IN PLACE THROUGH EARLY SATURDAY. OVERALL...THE THREAT FOR EXCESSIVE RAINFALL HAS BEEN DIMINISHED A BIT AS THE ROUNDS OF STORMS LOOK PROGRESSIVE ENOUGH AND MUCH OF THE AREA CAN HANDLE THE EXPECTED AMOUNTS. AS SUCH...WILL CONTINUE THE HYDROLOGIC OUTLOOK /ESFARX/ && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ZT LONG TERM....ZT AVIATION...ROGERS HYDROLOGY....ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
328 PM CDT WED AUG 27 2014 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 328 PM CDT WED AUG 27 2014 FORECAST FOCUS IS ON PRECIPITATION TIMING AND AMOUNTS...THREAT FOR HEAVY RAIN WITH LOCALIZED FLOODING. AS OF MID AFTERNOON...WATER VAPOR IMAGERY OVERLAID WITH RAP 500 MB HEIGHTS SHOWED DECAYING DISTURBANCE ACROSS IOWA...WITH MAIN CLOSED LOW ROTATING INTO NORTHWESTERN COLORADO. WEAK IMPULSES WERE RIDING THE PERIPHERY OF THE TROUGH...AND IT IS THESE IMPULSES THAT WILL BE THE PLAYERS FOR THE NEXT 24 TO 48 HOURS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. AT THE SURFACE...LINGERING SHOWERS AND THUNDERSTORMS HAVE BEEN CONFINED TO SOUTHERN AND SOUTHWESTERN IOWA...KEEPING FRONTAL BOUNDARY ACROSS SOUTHERN IOWA / NORTHERN MISSOURI. THE 65F DEWPOINT LINE IS GENERALLY SOUTH OF I-80. THE LARGEST CHANGES TO ONGOING FORECAST HAVE BEEN RELATED TO PRECIPITATION TIMING...AS 27.12Z MODEL CYCLES TREND TOWARD A LATER ARRIVAL OF THE GREATEST 850MB MOISTURE TRANSPORT OVERNIGHT THROUGH THE DAY ON THURSDAY. MOST OF THE DETERMINISTIC AND HI-RES MODELS SHOW A SHIELD OF RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS REACHING NORTHEAST IOWA / SOUTHEAST NOT UNTIL THE EARLY MORNING HOURS /4 TO 6 AM/ THEN MOVING INTO WESTERN WISCONSIN MID TO LATE MORNING. PRECIPITATION CHANCES HAVE BEEN ADJUSTED...BUT OVERALL CONFIDENCE REMAINS VERY HIGH SO KEPT 90 TO 100 CHANCES. THE NOSE OF THE 850MB MOISTURE TRANSPORT LIFTS THROUGH THE AREA DURING THE DAY...SO ANY COMPLEX OF SHOWERS/STORMS WILL LIKELY BE PROGRESSIVE. HOWEVER...THE ATMOSPHERE WILL INCREASINGLY BECOME MORE FAVORABLE FOR HEAVY RAINFALL RATES...AS PWATS APPROACH 2 INCHES. WARM CLOUD DEPTHS EXCEED 4 KM ACROSS MUCH OF THE AREA. THE STORM TOP WINDS ARE PROGGED TO BE 25 TO 30 KTS...WHICH SHOULD HELP KEEP CONVECTION PROGRESSIVE ENOUGH. THOUGH WITH BROAD WARM AIR ADVECTION AND ISENTROPIC LIFT DURING THE DAY...HAVE KEPT HIGH PRECIPITATION CHANCES THROUGH THE EVENING HOURS. THE GREATER FOCUS SEEMS TO BE ON WESTERN INTO NORTH CENTRAL WISCONSIN...THOUGH MOST AREAS WILL SEE SHOWERS/STORMS THROUGHOUT THE DAY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 328 PM CDT WED AUG 27 2014 THE MAIN 500MB SHORTWAVE BEGINS TO SWING THROUGH THE UPPER MIDWEST FRIDAY EVENING INTO SATURDAY MORNING...WITH THE GREATEST 500-300MB PV ADVECTION ALIGNED FROM CENTRAL AND EASTERN IOWA INTO SOUTHERN WISCONSIN. THE MOIST AIRMASS WILL LINGER THROUGH THIS PERIOD AS WELL...AS THE OVERALL ENVIRONMENT SUPPORTS EFFICIENT RAIN PRODUCES. THE SURFACE FRONT WILL LIKELY STALL FROM IOWA INTO SOUTHERN WISCONSIN AND COULD BE THE FOCUS FOR SEVERAL EPISODES FOR SHOWERS/STORMS. DEPENDING ON THE HEAVY RAINFALL OUTCOME IN ROUND ONE...THIS PERIOD WILL NEED TO BE WATCHED FOR REPEATED ROUNDS. THOUGH AT THIS POINT...IT LOOKS LIKE DIFFERENT AREAS WILL SEE THE ROUNDS OF HEAVIER RAINFALL. IT DOES LOOK LIKE BY SATURDAY MOST OF THE UPPER LEVEL ENERGY MOVES EAST...AND THE PRECIPITATION CHANCES ARE CONFINED TO SOUTHERN AND CENTRAL WISCONSIN. FOR THOSE PLANNING ACTIVITIES THIS UPCOMING HOLIDAY WEEKEND...THE SATURDAY NIGHT TO SUNDAY MORNING TIMEFRAME HAS THE GREATEST LIKELIHOOD TO SEE DRIER PERIODS. SUNDAY THROUGH MONDAY WILL FEATURE AN APPROACHING UPPER LEVEL SHORTWAVE FROM THE NORTHERN PLAINS. 27.12Z MODELS ALREADY SHOW THIS FEATURE TO BE A BIT VIGOROUS AS IT SWINGS THROUGH. AT THE SURFACE...THIS WILL DRIVE A COLD FRONT THROUGH THE UPPER MIDWEST. THERE REMAINS SOME TIMING DIFFERENCES BETWEEN THE GFS/ECMWF/GEM BUT THE TREND HAS BEEN FOR THE FRONTAL PASSAGE TO BE LATE SUNDAY NIGHT OR EARLY MONDAY MORNING. SEVERE CHANCES LOOK LIMITED RIGHT NOW GIVEN TIMING BUT 500 TO 1000 MUCAPE TRANSLATES AHEAD OF THE FRONT WITH MARGINAL 0-6KM SHEAR VALUES /20 KTS/. SOMETHING TO KEEP AN EYE WITH THE HOLIDAY WEEKEND...ESPECIALLY IF THE TIMING BECOMES MORE FAVORABLE DURING PEAK HEATING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1230 PM CDT WED AUG 27 2014 GOOD VFR CONDITION EXPECT THRU THIS AFTERNOON/EVENING AS COOLER/DRIER HIGH PRESSURE HOLDS OVER THE AREA. INCREASING MOISTURE/LIFT SPREAD NORTHEAST TOWARD THE AREA AFTER MIDNIGHT...REACHING THE KRST AREA TOWARD MORNING AND THE KLSE AREA AROUND MID MORNING THU. INSTABILITY IS INITIALLY LIMITED...WITH MAINLY -SHRA EXPECTED WHEN THE PRECIP SPREADS INTO THE AREA. WITH THE DRIER HIGH PRESSURE TO OVERCOME... CIGS/VSBYS WILL BE VFR/MVFR AS THE PRECIP FIRST ARRIVES. WITH INCREASING LIFT/INSTABILITY THRU THU MORNING...TSRA EXPECTED TO BECOME EMBEDDED IN THE BROADER SHRA/RAIN AREA. INCLUDED TEMPO TSRA AT KRST AFTER 13Z AND KLSE AFTER 16Z...HOWEVER TSRA THU MORNING MAY BE MORE OCCASIONAL RUMBLES OF THUNDER VS. MORE TYPICAL JULY/AUG CONVECTION. WITH CONTINUED RAIN THU MORNING AND SATURATION OF THE LOWER LEVELS...CIGS/VSBYS AT KRST TO LOWER INTO MVFR/IFR AFTER 15Z...WITH THESE LOWER CIGS/VSBYS LOOKING TO REACH KLSE NEAR/AFTER 18Z. MVFR/IFR CIGS/VSBYS IN SHRA/TSRA THEN LOOK TO PERSIST THU AFTERNOON/NIGHT. && .HYDROLOGY...THURSDAY THROUGH FRIDAY NIGHT ISSUED AT 328 PM CDT WED AUG 27 2014 VERY FAVORABLE SETUP FOR EFFICIENT...HEAVY RAIN PRODUCERS OVER THE NEXT FEW DAYS. WARM CLOUD DEPTHS CONTINUE TO HOVER NEAR 4000 M /IF NOT HIGHER/ WHILE PWATS PEAK AROUND 2 INCHES THURSDAY- THURSDAY NIGHT. HEAVIER RAIN SIGNALS ARE PROGRESSIVE...THROUGH NORTHERN IOWA INTO SOUTHEAST MINNESOTA AND THEN NORTH CENTRAL WISCONSIN. FOR ROUND TWO...THE HIGHER THREAT LOOKS TO BE ACROSS EASTERN IOWA INTO SOUTHERN WISCONSIN. RUN TOTAL QPF FROM THE EC/GFS/GEM THROUGH SATURDAY RANGE FROM 2 TO 4 INCHES. LOCALLY HIGHER AMOUNTS ARE LIKELY. AT THIS MOMENT...THINK THERE COULD BE QUICK RISES ON SOME RIVERS...BUT SHOULD STAY WITHIN BANK. AS ALONG AS STORMS MOVE...AND AREAS DON/T GET REPEATED HITS...THE FLASH FLOOD THREAT IS REDUCED. ALL SAID...WITH THE HIGH LIKELIHOOD OF HEAVY RAIN...AND THE POTENTIAL FOR SIGNIFICANT AMOUNTS...WILL MAINTAIN HYDROLOGIC OUTLOOK TO HIGHLIGHT THE THREATS. A FLASH FLOOD WATCH MAY BE NECESSARY IF SIGNALS ARE FOR THE ROUNDS OF HEAVY RAINFALL LOOK TO REPEAT OVER THE SAME AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ZT LONG TERM....ZT AVIATION.....RRS HYDROLOGY....ZT/RIECK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1137 AM MDT WED AUG 27 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 355 AM MDT WED AUG 27 2014 CLOSED UPPER LOW WAS ENTERING UT FROM NV PER WATER VAPOR IMAGERY. SOUTHERLY FLOW ALOFT DRAWING MOISTURE FROM HURRICANE MARIE WEST OF BAJA CA INTO THE CENTRAL AND SOUTHERN ROCKY MOUNTAIN REGION. SHORTWAVE LIFTING NORTHWARD ACROSS NORTHWEST CO PRODUCING SCATTERED SHOWERS AND ISOLATED TSTORMS. OTHER CONVECTION WAS DEVELOPING NORTH OF A STALLED SURFACE FRONT FROM NORTHEAST CO INTO CENTRAL NE. SKIES WERE PARTLY TO MOSTLY CLOUDY WITH SOME STRATUS FORMING OVER EAST CENTRAL WY. WINDS WERE LIGHT AND VARIABLE. THE 00Z SHORT RANGE MODEL GUIDANCE IS IN GOOD AGREEMENT PROGGING THE UPPER LOW PRESSURE CENTER EVOLVING INTO A OPEN WAVE AS IT PROGRESSES SLOWLY EAST INTO WESTERN CO THIS AFTERNOON. THE MAJORITY OF THE MODELS INCLUDING THE ESRL HRRR DEVELOP AN WEST-EAST BAND OF SHOWERS AND EMBEDDED TSTORMS ALONG THE I-80 CORRIDOR AFTER 12Z AS THE SHORTWAVE LIFTS NORTH INTO SOUTHERN WY. ADDITIONAL SHOWERS AND SCATTERED TSTORMS DEVELOP THIS AFTERNOON WITH UPSLOPE SOUTHEASTERLY FLOW. LOW/MID LEVEL INSTABILITY AND 0-6KM SHEAR PROFILES ARE NOT CONDUCIVE FOR SEVERE TSTORM DEVELOPMENT...HOWEVER PRECIP WATER VALUES EXCEED AN INCH MORE INDICATIVE OF LOCALLY HEAVY RAINFALL. STORM MOTION WILL BE TO THE NORTH AND NORTHEAST AROUND 25 KT WHICH SHOULD MITIGATE THE FLOOD THREAT. FOLLOWED THE HPC QPF WHICH PROGS 0.5-1.0 INCH RAINFALL OVER THE CWA. IT WILL BE 5-10 DEGREES COOLER TODAY COMPARED TO YESTERDAY WITH 700MB TEMPERATURES AROUND 7C. SHOWER COVERAGE WILL DECREASE FROM NUMEROUS THIS EVENING TO LOW END SCATTERED LATER TONIGHT. THURSDAY WILL TREND DRIER AS THE UPPER TROUGH AND BETTER MOISTURE SHIFT SOUTH AND EAST OF THE CWA. STILL CANNOT RULE OUT ISOLATED TO SCATTERED CONVECTION ALONG AND SOUTH OF I-80 THOUGH. QPF WILL BE LIGHTER...GENERALLY LESS THAN A QUARTER INCH. HIGH TEMPERATURES WILL BE 3-5 DEGREES WARMER...ESPECIALLY EAST CENTRAL WY AND NORTHERN NE PANHANDLE WITH GREATER INSOLATION. TRANSITORY SHORTWAVE RIDGE THURSDAY NIGHT SHIFTS EAST FRIDAY AS A SHORTWAVE TROUGH MOVES EAST ACROSS MT AND NORTHERN WY. THIS SYSTEM WILL NOT HAVE MUCH AVAILABLE MOISTURE TO WORK WITH...BUT DYNAMICS ENOUGH TO OVERCOME AND PRODUCE ISOLATED AFTERNOON CONVECTION ALONG AND NORTH OF A LINE FROM DOUGLAS TO CHADRON...AS WELL AS OVER THE MOUNTAINS. 700MB TEMPERATURES RISE TO AROUND 10C FRIDAY AFTERNOON WITH READINGS IN THE 80S EAST OF THE LARAMIE RANGE. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM MDT WED AUG 27 2014 MILD AND MAINLY DRY WEATHER FRI NIGHT INTO SATURDAY AS A MINOR UPPER RIDGE MOVES EAST ACROSS THE AREA. A QUICK-MOVING SHORTWAVE SHOULD PASS MAINLY NORTH OF THE CWA LATE SAT BUT COULD BRING A FEW SHOWERS TO MAINLY NORTHERN PARTS OF THE CWA THEN. MORE SIGNIFICANT UPPER TROF WILL MOVE ACROSS SUNDAY BRINGING MORE WIDESPREAD SHOWERS AND A FEW TSTMS. ECMWF MORE BULLISH WITH THIS SYSTEM WITH THE GFS CONSIDERABLY WEAKER. MILD AND MAINLY DRY WEATHER RETURNS FOR MONDAY AND TUESDAY AS THE CWA RESIDES ON THE SOUTHERN SIDE OF BROAD UPPER CYCLONIC FLOW THAT WILL PROGRESS ACROSS THE NORTHERN PART OF THE COUNTRY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING) ISSUED AT 1130 AM MDT WED AUG 27 2014 SCATTERED TO NUMEROUS SHOWERS AND STORMS CAN BE EXPECTED ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE TODAY. MOST TERMINALS WILL SEE LOWER CIGS BETWEEN 5K AND 8K FEET AGL THROUGH THE TAF PERIOD...WITH OCCASIONAL MVFR CONDITIONS WITH BKN-TO-OVC SKIES AROUND 2K FEET. LOWEST CIGS/VSBYS WILL OCCUR BENEATH SHOWERS AND STORMS. A FEW STRONGER STORMS ARE POSSIBLE THIS AFTN FOR THE NE PANHANDLE SITES...WITH TORRENTIAL DOWNPOURS AND STRONG/VARIABLE WINDS POSSIBLE ALONG WITH SMALL HAIL. SHOWER ACTIVITY IS LIKELY TO PERSIST ACROSS MUCH OF THE REGION OVERNIGHT. WE CANNOT RULE OUT MVFR CIGS LATE TONIGHT OR EARLY THU...ESPECIALLY IN AREAS WHICH RECIEVE HEAVIER RAINFALL THIS AFTN. && .FIRE WEATHER... ISSUED AT 252 AM MDT WED AUG 27 2014 A LOW PRESSURE SYSTEM OVER UTAH EARLY THIS MORNING WILL SLOWLY TRACK EAST THROUGH COLORADO DURING THE NEXT 24 HOURS...AND INTO THE CENTRAL PLAINS BY FRIDAY. NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL PRODUCE WETTING RAINFALL TODAY AND TONIGHT. DRIER AND WARMER WEATHER WILL RETURN THURSDAY AND CONTINUE THROUGH SATURDAY...ALONG WITH GUSTY WEST TO SOUTHWEST WINDS. THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS SUNDAY AND LABOR DAY WITH THE PASSAGE OF A UPPER LEVEL TROUGH AND PACIFIC COLD FRONT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...JAMSKI LONG TERM...RE AVIATION...HAMMER FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
355 AM MDT WED AUG 27 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 355 AM MDT WED AUG 27 2014 CLOSED UPPER LOW WAS ENTERING UT FROM NV PER WATER VAPOR IMAGERY. SOUTHERLY FLOW ALOFT DRAWING MOISTURE FROM HURRICANE MARIE WEST OF BAJA CA INTO THE CENTRAL AND SOUTHERN ROCKY MOUNTAIN REGION. SHORTWAVE LIFTING NORTHWARD ACROSS NORTHWEST CO PRODUCING SCATTERED SHOWERS AND ISOLATED TSTORMS. OTHER CONVECTION WAS DEVELOPING NORTH OF A STALLED SURFACE FRONT FROM NORTHEAST CO INTO CENTRAL NE. SKIES WERE PARTLY TO MOSTLY CLOUDY WITH SOME STRATUS FORMING OVER EAST CENTRAL WY. WINDS WERE LIGHT AND VARIABLE. THE 00Z SHORT RANGE MODEL GUIDANCE IS IN GOOD AGREEMENT PROGGING THE UPPER LOW PRESSURE CENTER EVOLVING INTO A OPEN WAVE AS IT PROGRESSES SLOWLY EAST INTO WESTERN CO THIS AFTERNOON. THE MAJORITY OF THE MODELS INCLUDING THE ESRL HRRR DEVELOP AN WEST-EAST BAND OF SHOWERS AND EMBEDDED TSTORMS ALONG THE I-80 CORRIDOR AFTER 12Z AS THE SHORTWAVE LIFTS NORTH INTO SOUTHERN WY. ADDITIONAL SHOWERS AND SCATTERED TSTORMS DEVELOP THIS AFTERNOON WITH UPSLOPE SOUTHEASTERLY FLOW. LOW/MID LEVEL INSTABILITY AND 0-6KM SHEAR PROFILES ARE NOT CONDUCIVE FOR SEVERE TSTORM DEVELOPMENT...HOWEVER PRECIP WATER VALUES EXCEED AN INCH MORE INDICATIVE OF LOCALLY HEAVY RAINFALL. STORM MOTION WILL BE TO THE NORTH AND NORTHEAST AROUND 25 KT WHICH SHOULD MITIGATE THE FLOOD THREAT. FOLLOWED THE HPC QPF WHICH PROGS 0.5-1.0 INCH RAINFALL OVER THE CWA. IT WILL BE 5-10 DEGREES COOLER TODAY COMPARED TO YESTERDAY WITH 700MB TEMPERATURES AROUND 7C. SHOWER COVERAGE WILL DECREASE FROM NUMEROUS THIS EVENING TO LOW END SCATTERED LATER TONIGHT. THURSDAY WILL TREND DRIER AS THE UPPER TROUGH AND BETTER MOISTURE SHIFT SOUTH AND EAST OF THE CWA. STILL CANNOT RULE OUT ISOLATED TO SCATTERED CONVECTION ALONG AND SOUTH OF I-80 THOUGH. QPF WILL BE LIGHTER...GENERALLY LESS THAN A QUARTER INCH. HIGH TEMPERATURES WILL BE 3-5 DEGREES WARMER...ESPECIALLY EAST CENTRAL WY AND NORTHERN NE PANHANDLE WITH GREATER INSOLATION. TRANSITORY SHORTWAVE RIDGE THURSDAY NIGHT SHIFTS EAST FRIDAY AS A SHORTWAVE TROUGH MOVES EAST ACROSS MT AND NORTHERN WY. THIS SYSTEM WILL NOT HAVE MUCH AVAILABLE MOISTURE TO WORK WITH...BUT DYNAMICS ENOUGH TO OVERCOME AND PRODUCE ISOLATED AFTERNOON CONVECTION ALONG AND NORTH OF A LINE FROM DOUGLAS TO CHADRON...AS WELL AS OVER THE MOUNTAINS. 700MB TEMPERATURES RISE TO AROUND 10C FRIDAY AFTERNOON WITH READINGS IN THE 80S EAST OF THE LARAMIE RANGE. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM MDT WED AUG 27 2014 MILD AND MAINLY DRY WEATHER FRI NIGHT INTO SATURDAY AS A MINOR UPPER RIDGE MOVES EAST ACROSS THE AREA. A QUICK-MOVING SHORTWAVE SHOULD PASS MAINLY NORTH OF THE CWA LATE SAT BUT COULD BRING A FEW SHOWERS TO MAINLY NORTHERN PARTS OF THE CWA THEN. MORE SIGNIFICANT UPPER TROF WILL MOVE ACROSS SUNDAY BRINGING MORE WIDESPREAD SHOWERS AND A FEW TSTMS. ECMWF MORE BULLISH WITH THIS SYSTEM WITH THE GFS CONSIDERABLY WEAKER. MILD AND MAINLY DRY WEATHER RETURNS FOR MONDAY AND TUESDAY AS THE CWA RESIDES ON THE SOUTHERN SIDE OF BROAD UPPER CYCLONIC FLOW THAT WILL PROGRESS ACROSS THE NORTHERN PART OF THE COUNTRY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 330 AM MDT WED AUG 27 2014 SHOULD SEE LOWERING CIGS ACROSS MANY AERODROMES THIS MORNING TO MOSTLY MVFR AS SHOWERS AND A FEW TSTMS INCREASE IN COVERAGE WITH THE APPROACH OF AN UPPER DISTURBANCE. SFC LOW WILL DEVELOP OVER SE COLORADO THIS AFTERNOON TURNING WINDS ACROSS THE AREA TO A MORE UPSLOPE DIRECTION. IMPROVING CONDITIONS EXPECTED OVER SE WY TONIGHT BUT MVFR CIGS SHOULD HOLD ACROSS PARTS OF THE NEB PANHANDLE. && .FIRE WEATHER... ISSUED AT 252 AM MDT WED AUG 27 2014 A LOW PRESSURE SYSTEM OVER UTAH EARLY THIS MORNING WILL SLOWLY TRACK EAST THROUGH COLORADO DURING THE NEXT 24 HOURS...AND INTO THE CENTRAL PLAINS BY FRIDAY. NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL PRODUCE WETTING RAINFALL TODAY AND TONIGHT. DRIER AND WARMER WEATHER WILL RETURN THURSDAY AND CONTINUE THROUGH SATURDAY...ALONG WITH GUSTY WEST TO SOUTHWEST WINDS. THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS SUNDAY AND LABOR DAY WITH THE PASSAGE OF A UPPER LEVEL TROUGH AND PACIFIC COLD FRONT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...JAMSKI LONG TERM...RE AVIATION...RE FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1125 PM MDT THU AUG 28 2014 .UPDATE... ISSUED AT 612 PM MDT THU AUG 28 2014 AS UPPER LOW PULLS AWAY TO THE EAST...SHOWERS AND THUNDERSTORMS HAVE BEEN DECREASING EARLIER THAN GRIDS PORTRAYED FOR NORTHERN/WESTERN PORTIONS OF THE FORECAST AREA. GRIDS WERE UPDATED TO REFLECT EARLIER END TO PRECIPITATION. LATEST HRRR SUGGESTS THAT PRECIPITATION SHOULD COME TO AN END FOR MOST AREAS SHORTLY AFTER MIDNIGHT. -KT && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 238 PM MDT THU AUG 28 2014 CURRENTLY... SCATTERED SHOWERS WERE MAINLY OVER THE GREATER PIKES PEAK REGION AND C MTNS...WITH MOST OF THE ACTIVITY ON THE LIGHT SIDE. TEMPS ACROSS THE REGION WERE ON THE COOL SIDE...WITH READING MAINLY IN THE 60S TO LOWER 70S. WAT VAP IMGY SHOWS THE TROUGH ALOFT WAS OVER THE EASTERN PLAINS OF CO AND WAS MOVING SLOWLY EAST. SCATTERED SHOWERS WILL CONTINUE TO MOVE SOUTHEAST ON THE BACKSIDE OF THE UPPER LOW THROUGH THE EARLY EVENING HOURS. AS HEATING DECREASES...PRECIP WILL DECREASE WITH ONLY SOME ISOLD SHOWERS OVER THE FAR E PLAINS BY LATE EVENING. WITH LIMITED CAPE...NOT EXPECTING MUCH IN THE WAY OF STRONG STORM ACTIVITY OR HEAVY RAIN...AND ANY STORMS SHOULD MOVE SOUTHEAST AT A STEADY CLIP. FOR TOMORROW...AS UPPER TROUGH MOVE EAST AND HEIGHTS BEING TO RISE...ALL GUIDANCE SHOWS AREAS DRYING OUT AND TEMPS WARMING UP INTO THE 80S ACROSS THE PLAINS...60S AND 70S VALLEYS AND 40S AND 50S MTNS. SHOWERS WILL MAINLY BE RELEGATED TO THE MTNS TOMORROW AFTERNOON...WITH NEARLY ALL OF THE LOWER ELEVATIONS REMAINING DRY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 238 PM MDT THU AUG 28 2014 ...HOT AND DRY END OF AUGUST AND BEGINNING OF SEPTEMBER... EXTENDED FORECAST NOT LOOKING TOO ACTIVE AT THIS POINT. AFTER THIS CURRENT SYSTEM MOVES TO THE EAST OUR AREA WILL BE UNDER STRENGTHENING W-SW FLOW...WHICH WILL TEND TO KEEP THE PLAINS ON THE WARM SIDE AND MAINLY DRY. THERE WILL BE ENOUGH MID LEVEL MOISTURE FOR SOME ISOLD STORMS OVER THE MTS...BUT NOT MUCH ELSEWHERE. SHOULD GET INTO THE 90S OVER THE PLAINS FOR BOTH SAT AND SUN...WITH POPS NEGLIGIBLE. MT AREAS WILL SEE COMFORTABLE 70S THIS WEEKEND. AS THE JET STAYS MAINLY TO OUR NORTH...A SHORT WAVE TROUGH WILL PASS THROUGH ON SUNDAY...BUT SHOULD HAVE LITTLE IMPACT OTHER THAN A SLIGHT COOLING OFF FOR MONDAY. WE THEN STAY UNDER BROAD CYCLONIC TO ZONAL FLOW AS THE JET REMAINS OVER THE NORTHERN ROCKIES INTO THE HIGH PLAINS. A FEW WEAK DISTURBANCES WILL SET OFF SOME CONVECTION OVER KS AND NE CO...POSSIBLY SNEAKING INTO NE PORTIONS OF OUR CWA...BUT FOR THE MOST PART WE REMAIN ON THE DRY AND WARM SIDE. DOES NOT LOOK LIKE ANY REAL RETURN OF THE MONSOON UNTIL POSSIBLY THE LATTER PART OF NEXT WEEK...AS A DEEPER TROUGH BUILDS OVER THE PACNW AND WE BEGIN TO SEE A RETURN OF SRLY FLOW ALOFT. NEXT WEEKEND LOOKS && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1119 PM MDT THU AUG 28 2014 VFR CONDITIONS EXPECTED OVERNIGHT AS SKIES CLEAR OUT BEHIND THE DEPARTING SYSTEM. THERE MAY BE SOME ENHANCED NORTHERLY DRAINAGE WINDS AT TIMES AT KCOS OVERNIGHT. ON FRIDAY THERE WILL BE POCKETS OF WESTERLY WINDS 10-15 KTS IN THE MORNING ALONG THE LEE OF THE SOUTHEAST MTS...HOWEVER WINDS WILL LIGHTEN AND SHIFT AROUND TO THE SOUTH TO SOUTHEAST AT KCOS AND KPUB WITH SPEEDS AROUND 10 KTS DURING THE AFTERNOON. KALS WILL SEE LIGHT SOUTHERLY WINDS AROUND 10 KTS DEVELOP IN THE AFTERNOON. ISOLATED THUNDERSTORMS WILL DEVELOP OVER THE MTNS AFTER 18Z THEN DRIFT TO THE SOUTHEAST ACROSS THE ADJACENT PLAINS. KCOS HAS THE BEST CHANCE OF SEEING -TSRA AFFECT THE TERMINAL SO HAVE INTRODUCED A VCTS GROUP AFTER 21Z. ISOLATED -TSRA COULD AFFECT KALS AND KPUB...BUT PROBABILITY LOOKS TOO LOW TO WARRANT INCLUSION IN THE TAF AT THIS POINT. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KT SHORT TERM...HODANISH LONG TERM...ROSE AVIATION...KT
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
112 AM CDT FRI AUG 29 2014 .DISCUSSION... 714 PM CDT PAIR OF MCVS NOTED ON RADAR IMAGERY CONTINUE TO MOVE EASTWARD DRIVING SLOWLY DECAYING CONVECTIVE COMPLEX EASTWARD INTO OUR CWA EARLY THIS EVENING DESPITE THE MUCH MORE STABLE AND SOMEWHAT DRIER AIR MASS OVER THE REGION. HAVE ALREADY UPDATED PRECIP TRENDS A COUPLE TIME TO ACCOUNT FOR THE RAIN THIS EVENING. ANTICIPATE CONTINUED WEAKENING TREND...PARTICULARLY FROM THE NORTH...IN THIS AREA OF LEFT OVER RAIN AND EVEN SOME LINGERING THUNDER. THE THREAT OF THUNDER WITH THE NORTHERN MCV TRACKING CLOSE TO I-88 LOOKS TO END VERY SOON...WHILE THE CONVECTION WITH THE SOUTHERN MOST MCV LIES CLOSE ENOUGH TO MORE UNSTABLE AIR TO POTENTIALLY MAINTAIN THUNDERSTORMS ACROSS THE SOUTHERN TIER OF OUR CWA THE NEXT FEW HOURS. IN THE WAKE OF THESE MCVS...WHICH REALLY HAVENT BEEN HANDLED WELL BY NUMERICAL GUIDANCE...SHOULD SEE A PERIOD OF DRY CONDITIONS HOWEVER MODELS DO BREAK OUT ADDITIONAL CONVECTION OVERNIGHT WHICH ISN`T THAT UNREASONABLE GIVEN THE NORTHWARD ADVANCING WARM FRONT. IZZI //PREV DISCUSSION... 230 PM CDT VISIBLE IMAGERY THIS AFTERNOON SHOWS A MID/UPR LEVEL CLOUD DECK LIFTING NORTHEAST ACROSS NORTHERN IL. REMNANTS FROM A MORNING COMPLEX OF THUNDERSTORMS RESIDES OVER IOWA...WITH SOME CONVECTIVE LOOK TO THE CLOUDS LINGERING INTO THIS AFTN. SFC TEMPS ACROSS THE FORECAST AREA HAVE BEEN ABLE TO WARM INTO THE MID/UPR 70S. A FEW POINTS SOUTH OF PONTIAC TO KANKAKEE HAVE PUSHED TO ARND 80 DEG...BUT WITH THE LIGHT EASTERLY FLOW AT THE SFC SOME WEAK SUBSIDENCE HAS BEEN NOTED WITH DEW POINTS BEING PUSHED INTO THE LOW 50S ALONG THE LAKESHORE AND MID/UPR 50S INLAND. THE MAIN CHALLENGE FOR THIS EVENING WILL FOCUS ON CONVECTIVE CHANCES/COVERAGE...WHICH WILL CONTINUE THROUGH DAYBREAK FRI. GUIDANCE HAS CONTINUED TO BACK OFF ON THE ARRIVAL OF PRECIP INTO THE FORECAST AREA...WHICH SEEMS TO LINE UP RELATIVELY WELL WITH THE CURRENT TRENDS. THE FRONTAL BOUNDARY WILL SLOWLY LIFT NORTH THIS EVENING...BUT NOT EXPECTING MUCH IN THE WAY OF PRECIP UNTIL PERHAPS AFT 04Z WITH A GRADUAL UPGLIDE OF PARCELS ALLOWS FOR MOISTENING. SOME ELEVATED CONVECTION COULD BEGIN TO DEVELOP...ALTHOUGH NOT EXPECTING MUCH COVERAGE OVERNIGHT. THE FOCUS FOR SLIGHTLY BETTER PRECIP COVERAGE WILL REMAIN ALONG THE NORTHERN ROW OF COUNTIES IN NORTHERN IL...HOWEVER CLOSER TO DAYBREAK FRI IT APPEARS SOME PRECIP/CONVECTION COULD SAG SOUTHEAST AND CLIP NORTHEAST IL/NORTHWEST IN BEFORE DISSIPATING. WITH INCREASING CLOUD COVER TONIGHT...IT SHUD LIMIT HOW COOL TEMPS BECOME. SO HAVE MADE ONLY MINOR ADJUSTMENTS TO THE TEMPS WITH GENERALLY MID/UPR 60S FOR LOWS. BEACHLER FRIDAY AND FRIDAY NIGHT... CLOSED UPPER LOW CURRENTLY NEAR THE COLORADO FRONT RANGE WILL SLOWLY TRAVERSE EAST TOWARDS THE MID-MISSOURI VALLEY FRIDAY BECOMING AN OPEN WAVE. AT THE SURFACE...BROAD AND WEAK SURFACE LOW WILL LIFT INTO THE UPPER MIDWEST WHILE SOUTHWEST FLOW RAMPS UP THROUGH THE COLUMN AS THE WARM FRONT LIFTS INTO THE CENTRAL GREAT LAKES. HEAT AND HUMIDITY WILL MAKE A RETURN AS THIS OCCURS. H85 TEMPS WARMING TO AROUND 18C WILL HELP SUPPORT MID/UPPER 80S DURING THE DAY FRIDAY...AND SURFACE DEWPOINTS ARE PROGGED TO PUSH BACK INTO THE LOW POSSIBLY MID 70S. THIS WILL RESULT IN MODERATE INSTABILITY DEVELOPING DURING THE DAY...AND ONLY WEAKLY CAPPED DURING THE AFTERNOON AS BROAD HEIGHT FALLS ASSOCIATED WITH THE UPPER WAVE START TO OVERSPREAD THE AREA. THERE DOESNT SEEM TO BE MUCH FOCUS IN THE LOWER LEVELS SO WOULD EXPECT ONLY SCATTERED THUNDERSTORM DEVELOPMENT ACROSS THE REGION FRIDAY AFTERNOON/EVENING. UPPER WAVE BEGINS TO MOVE INTO THE UPPER MIDWEST TOMORROW NIGHT AND BROAD WARM ADVECTION OUT AHEAD DURING THE EVENING AND OVERNIGHT HOURS WILL HELP SUSTAIN SOME CONVECTION LATE BUT WOULD EXPECT SOME NOCTURNAL DOWNTICK IN ACTIVITY OVERNIGHT WITH THE LOW LEVEL JET FOCUSED WELL TO OUR NORTH. GFS/NAM SEEM TO BE OVERDOING POPS MUCH OF THE DAY AND NIGHT FRIDAY...AND OPTED TO LEAN CLOSER TO ECMWF THESE PERIODS. THIS WEEKEND... COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA STARTING VERY EARLY ON SATURDAY. WHILE NOT A FAVORABLE DIURNAL TIME...WE SHOULD STILL HAVE SOME VERY MODEST INSTABILITY IN PLACE THAT WILL SUPPORT SOME EARLY DAY THUNDERSTORMS ALONG THE FRONTAL BOUNDARY...WHICH WOULD BE ABLE TO EXPAND IN COVERAGE AS THE DAY PROGRESSES AND THE BOUNDARY LAYER WARMS. IN ADDITION...GUIDANCE SUGGESTS A SECOND SHORTWAVE WILL WRAP INTO THE AREA THAT WILL PROVIDE ADDITIONAL BROAD SCALE ASCENT. THE ECMWF IS ABOUT SIX HOURS SLOWER WITH THIS FEATURE COMPARED TO THE NAM/GFS...WITH THE GEM A COMPROMISE...SO THERE REMAINS SOME UNCERTAINTY IN TIMING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT SATURDAY NIGHT INTO SUNDAY AND WILL PROVIDE A BRIEF RESPITE FROM THE ACTIVE WEATHER. THE ATMOSPHERE LOOKS TO QUICKLY RELOAD HOWEVER WITH THERMAL RIDGE ONCE AGAIN STARTING TO TILT BACK OVER THE AREA WITH H85 TEMPS AROUND 20C BY LATER IN THE DAY SUNDAY. NEXT WEEK... AN ACTIVE PATTERN LOOKS TO PERSIST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH A SERIES OF WAVES PUSHING ACROSS THE REGION BRINGING CONTINUED PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS. ANOTHER COLD FRONT WILL PUSH ACROSS THE AREA LATER ON MONDAY WITH THE FRONTAL BOUNDARY STALLING JUST TO OUR SOUTH. THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY ON HOW FAR NORTH THE BOUNDARY MAY LIFT WITH THE BEST PRECIP CHANCES FOCUSED IN THE VICINITY OF THE FRONT AS A SERIES OF UPPER LEVEL DISTURBANCES PUSH ACROSS THE AREA. PWATS REMAIN JUICY ALONG THE FRONT...AROUND TWO INCHES...AND GUIDANCE SUGGESTS THAT THERE COULD BE SEVERAL CONVECTIVE COMPLEXES NEXT WEEK WITH A CONCERN FOR HEAVY RAIN AND FLOODING SHOULD THIS PAN OUT. DEUBELBEISS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * ISOLATED SHRA/TSRA LATE TONIGHT INTO EARLY FRIDAY MORNING. * SCATTERED TSRA FRIDAY AFTERNOON/EARLY EVENING. * SOUTH WIND WITH GUSTS DEVELOPING TO 20KT LATE MORNING FRIDAY. KREIN //DISCUSSION...UPDATED 06Z... FORECAST CONCERNS WILL FOCUS ON SHRA/TSRA POTENTIAL THROUGH THE PERIOD AS WELL AS GUSTY SOUTH WINDS DEVELOPING LATE FRIDAY MORNING AND PERSISTING INTO EARLY FRIDAY EVENING. FOR THE REMAINDER OF THE OVERNIGHT HOURS...THE REGION WILL REMAIN UNDER SELY FLOW...NORTH OF A WARM FRONT CURRENTLY OVER CNTRL MO TO SRN IL. SOME REMNANT SHOWERS FROM EARLIER CONVECTIVE ACTIVITY ARE STILL SEEN ON THE LATEST RADAR IMAGERY...BUT THIS ACTIVITY IS DIMINISHING WITH TIME FOR MUCH OF THE REGION. THE EXCEPTION IS A SMALL AREA OF RAIN WHICH IS MORE PERSISTENT OVER ECNTRL IL. WITH MID LEVEL FLOW MORE SOUTHWESTERLY...THERE HAS BEEN A MORE PERSISTENT FETCH OF LIGHT PCPN INTO NWRN IL...SO KGYY COULD LIKELY SEE SOME LIGHT RAIN THROUGH THE NIGHT THOUGH NO ADDITION THUNDER IS ANTICIPATED WITH THIS PCPN. WITH A VERY MOIST AIRMASS IN PLACE FROM RECENT PCPN ALONG WITH LIGHT WINDS...THERE WILL BE THE POTENTIAL FOR SOME PATCHY BR WITH KDPA/KRFD BEING THE MORE LIKELY TAF SITES TO SEE VIS DROP AT LEAST INTO MVFR LEVELS. EXPECT THAT ORD/MDW SHOULD REMAIN VFR AS WINDS WILL REMAIN A LITTLE STRONGER AND TEMP/DEWPOINT SPREADS A LITTLE HIGHER. THE WARM FRONT WILL SLOWLY LIFT NWD THROUGH THE NIGHT AND PUSH NORTH OF THE TERMINALS BY LATE FRIDAY MORNING. AT THIS POINT...WINDS WILL SHIFT TO MORE SOUTHERLY. SOME BREAKS IN THE CLOUD COVER SHOULD ALLOW FOR DEEPER LAYER MIXING...TAPPING STRONGER WINDS ALOFT AND EXPECT THAT WINDS WILL BEGIN TO GUST TO 20KT FOLLOWING THE WARM FROPA. INSTABILITY WILL INCREASES VERY QUICKLY AS THE WARM FRONT PASSES TO THE NORTH AND WARM SECTOR AIR OVERSPREADS THE REGION BRINGING INCREASING TEMPERATURES AND DEWPOINTS. MID LEVEL IMPULSES SHOULD TRACK ACROSS THE AREA FRIDAY AFTERNOON AND EVENING IN UPPER LEVEL SWLY FLOW AS THE UPPER RIDGE PUSHES TO THE EAST AND A LARGER SCALE UPPER TROUGH MOVES ACROSS THE CENTRAL PLAINS. THESE IMPULSES WILL BE THE TRIGGERING MECHANISM FOR ADDITIONAL SHRA/TSRA...BUT IN THE ABSENCE OF ANY SFC FORCING...ACTIVITY WILL GENERALLY BE SCATTERED AND DIFFICULT TO TIME AT THE TERMINALS. SO...WILL MAINTAIN THE GOING PROB30 GROUP FOR TSRA WITH THE MOST FAVORABLE TIMING DURG THE AFTERNOON HOURS. HOWEVER...WITH SCATTERED COVERAGE...ANY OF THE TERMINALS COULD SEE SOME SHRA/TSRA A LITTLE EARLIER OR A LITTLE LATER THAN THE GOING PROB30 TIMING. KREIN //ORD AND MDW CONFIDENCE...UPDATED 06Z... * LOW CONFIDENCE IN THUNDER CHANCES/COVERAGE AND SPECIFIC TIMING FRIDAY AFTERNOON. * HIGH CONFIDENCE IN WIND TRENDS THROUGH THE PERIOD. * MEDIUM CONFIDENCE THAT ORD/MDW WILL REMAIN VFR THROUGH THE REMAINDER OF THE NIGHT AND INTO EARLY FRIDAY MORNING. KREIN //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... * SATURDAY...TSRA LIKELY. * SUNDAY...SLIGHT CHANCE OF TSRA. * MONDAY AND TUESDAY...CHANCE OF TSRA. * WEDNESDAY AND THURSDAY...SLIGHT CHANCE OF TSRA KMD && .MARINE... 123 PM CDT SURFACE HIGH PRESSURE OVER THE GREAT LAKES REGION THIS AFTERNOON WILL DRIFT TO THE EAST TONIGHT IN THE WAKE OF A DEPARTING UPPER TROUGH OVER NEW ENGLAND/QUEBEC...AND AHEAD OF ANOTHER SURFACE TROUGH AND WEAK COLD FRONT STRETCHING FROM FAR NORTHWEST ONTARIO TO THE CENTRAL PLAINS. WINDS ON LAKE MICHIGAN WILL SHIFT TO THE SOUTHEAST AND EVENTUALLY SOUTH HEADING INTO FRIDAY...AS AN AREA OF SURFACE LOW PRESSURE DEVELOPS ACROSS THE PLAINS AND LIFTS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. TIGHTENING OF THE PRESSURE GRADIENT SOUTHEAST OF THE LOW TRACK WILL RESULT IN S-SE WINDS INCREASING INTO THE 15-25 KT RANGE TONIGHT AND FRIDAY...GRADUALLY WEAKENING SATURDAY AS THE LOW MOVES OFF TO THE NORTHEAST AND A WEAK COLD FRONT TRAILS ACROSS THE LAKE FOLLOWED BY WEAK HIGH PRESSURE. THIS COLD FRONT APPEARS TO DISSIPATE OR STALL ACROSS FAR SOUTHERN LAKE MICHIGAN OR NORTHERN IL/IND LATE SATURDAY NIGHT OR EARLY SUNDAY BEFORE DEVELOPING BACK TO THE NORTH AS A WARM FRONT SUNDAY NIGHT AS ANOTHER AREA OF LOW PRESSURE DEVELOPS OVER THE PLAINS AND LIFTS NORTHEAST INTO THE WESTERN/NORTHERN LAKES LATE SUNDAY NIGHT INTO MONDAY. AGAIN...A TIGHTENING OF THE PRESSURE GRADIENT ALONG THE SOUTHEAST PERIPHERY OF THE LOW TRACK IS EXPECTED WITH WINDS AGAIN BECOMING SOUTHERLY INTO THE 15-25 KT RANGE ON MONDAY. ANOTHER TRAILING COLD FRONT WILL PASS ACROSS THE LAKE MONDAY NIGHT...WITH WEAK HIGH PRESSURE AND LIGHTER WINDS DEVELOPING TUESDAY. RATZER && .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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1159 PM CDT Thu Aug 28 2014 .SHORT TERM...(This evening through Friday) ISSUED AT 255 PM CDT THU AUG 28 2014 18z/1pm surface map shows warm front extending from northern Missouri into western Kentucky. Aloft...vigorous upper-level low is evident on water vapor imagery over eastern Colorado/western Kansas. Large cluster of showers/storms associated with the low developed along the front across Iowa last night and has since weakened as it lifted northeastward into drier air over the Upper Midwest/Great Lakes. Convection is still ongoing along outflow boundary from eastern Iowa into northern Missouri: however, most of this will remain W/NW of the KILX CWA late this afternoon into the early evening. Meanwhile, scattered convection is firing further south along the front across western Kentucky and this is expected to develop further north into central Illinois over the next couple of hours. HRRR has had a good handle on the convection and have followed its solution closely for the immediate short-term. Have therefore gone with scattered showers/thunder across all but the far NE CWA around Champaign and Danville this afternoon into the evening. Think convection will be diurnally driven and will dissipate shortly after sunset. As upper low slowly approaches from the west, corresponding downstream ridging will help push the warm front northward tonight into Friday. With strongest upper support remaining west of Illinois through the day, think convection will once again only be scattered in nature and primarily occur during peak heating. Have therefore gone with a mostly dry forecast during the morning, followed by chance PoPs during the afternoon. Best rain chances will be focused closer to the frontal boundary across the northern two-thirds of the CWA. High temperatures on Friday will be held down a bit by clouds/precip, but will still rise well into the 80s, with locations along/south of I-70 perhaps hitting the 90-degree mark. && .LONG TERM...(Friday night through Thursday) ISSUED AT 255 PM CDT THU AUG 28 2014 Upper wave currently over the Rockies expected to slowly move out and bring rain chances to the area, particularly Friday night and Saturday as the upper trof moves through the Midwest. Keeping the precip around on Saturday may result in slightly cooler temperatures by the afternoon. Once again, the cold front associated with the upper trof moves across the region, losing its distinct baroclinic zone and becoming more diffuse as it slows considerably just to the southeast near the Ohio River Valley. The remaining boundary will keep pops around for the areas in the southeastern portions of the state through the remains of the weekend until another larger trof moves across the country bringing more widespread rain and thunder for Sunday night into Monday. Signif differences between the ECMWF and the GFS with the GFS being weaker with the boundary and leaving a more stationary focus for prolonged showers...whereas the ECMWF is more progressive and dries out the region on Tuesday. At this point, the ECMWF builds a weak upper ridge into the Midwest and the GFS stays more active. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) ISSUED AT 1156 PM CDT THU AUG 28 2014 The new 06Z TAF valid time is expected to be much like the past couple. Predominantly VFR/quiet weather conditions are expected. However, scattered showers/storms are possible. Initially the main precipitation threat will be diurnally driven on Friday, but chances will also be increasing Friday evening with the approach of a cold front. As such, it is difficult to pinpoint precipitation until it is closer to arrival time. So, have limited most mention to VCTS. Storms, if they impact a terminal, may briefly reduce cigs/vsbys to MVFR or lower. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...HJS AVIATION...BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1210 AM CDT FRI AUG 29 2014 .SHORT TERM /TONIGHT/... ISSUED AT 315 PM CDT THU AUG 28 2014 PRIMARY FORECAST QUESTION FOR TONIGHT IS COVERAGE AND TIMING OF PRECIPITATION. RECENT RADAR TRENDS AND HIGH RESOLUTION MODELS SUCH AS THE WRF AND HRRR HAVE INDICATED A SIGNIFICANT DECREASING TREND IN PRECIP COVERAGE LATE THIS AFTERNOON AND EVENING...HOWEVER MOST SHORT RANGE MODELS CONTINUE TO FORECAST AN INCREASE ONCE AGAIN AFTER DARK TONIGHT. THIS IS CONSISTENT WITH THE SYNOPTIC SCENARIO CHARACTERIZED BY BROAD UPPER LEVEL DIFFLUENCE OVER A SATURATED ATMOSPHERE. HAVE CARRIED GENERALLY CHANCE POPS/SCATTERED WORDING THROUGH THE NIGHT GIVEN THE SUPPORT FOR REDEVELOPMENT...BUT HAVE LITTLE CONFIDENCE IN DETAILS OF TIMING AND LOCATION THUS THE POP FORECAST IS BROADBRUSHED FOR NOW. OTHERWISE LITTLE CHANGE WAS MADE TO THE ONGOING FORECAST. .LONG TERM /FRIDAY THROUGH THURSDAY/... ISSUED AT 315 PM CDT THU AUG 28 2014 WITH UPPER LEVEL TROUGH STILL WEST OF THE AREA THROUGH EARLY SATURDAY MORNING...LIKELY TO SEE SOME ADDITIONAL ROUNDS OF THUNDERSTORMS ACROSS THE REGION THROUGH THAT TIME. OVER THE NEXT 24 TO 36 HOURS...THE HIGHEST PRECIPITABLE WATER VALUES WILL GRADUALLY SHIFT EAST OF THE REGION AS H850 MOISTURE TRANSPORT BEGINS TO SHIFT EAST AS WELL. BY 12Z FRIDAY...ONE ADDITIONAL WAVE...THE KICKER WAVE...WILL BE LOCATED OVER SOUTHEAST KS/WESTERN MO. THIS SHOULD LIFT NORTHEAST DURING THE NEXT 24 HOURS RESULTING IN INCREASING LIFT OVER THE REGION FRIDAY AFTERNOON AND EVENING. IN COMBINATION WITH THAT A COLD FRONT AND UPPER LEVEL LOW OVER SOUTHERN CANADA WILL DRIFT SOUTHEAST AND ALSO AID IN DISPLACING THE TROUGH ACROSS THE GREAT PLAINS. THROUGH THE PERIOD FRIDAY INTO EARLY SATURDAY... ANOTHER HALF INCH TO INCH OF RAINFALL IS LIKELY TO FALL WITH THE HEAVIER TOTALS OVER THE NORTH AND NORTHEAST PORTION OF THE FORECAST AREA. WITH RAINFALL RATES SLOWING DOWN...FLASH FLOODING IS PROBABLY NO LONGER A THREAT...BUT SATURATED GROUND MAY LEAD TO SOME MINOR RUNOFF PROBLEMS AT TIMES INCLUDING SOME PONDING OF WATER AND MINOR STREET FLOODING IN AREAS OF POOR DRAINAGE. TEMPERATURES TOMORROW WILL LIKELY WARM A BIT IN THE SOUTHEAST IN THE LOWER 80S...AHEAD OF THE WAVE WITH WARM AIR ADVECTION AND SOME POTENTIAL BREAKS IN THE CLOUD COVER IN THE SOUTHEAST. AS THE COOL FRONT MOVES EAST PRECIP CHANCES SHOULD END ACROSS THE REGION SATURDAY MORNING WITH SOME SUNSHINE RETURNING TO THE AREA BY MORNING. HIGHS WILL BE SLIGHTLY WARMER...BUT STILL WITHIN THE A FEW DEGREES OF HIGHS OF FRIDAY WITH MORE SUNSHINE...BUT SOME SLIGHT COOL AIR ADVECTION. MODELS IN GENERAL AGREEMENT WITH THE NEXT STRONG WAVE EXPECTED TO ARRIVE BY SUNDAY AFTERNOON....WITH A RATHER WARM DAY AHEAD AS H850 RISE TO NEAR 20C BY AFTERNOON. THE GFS SHOWS THAT PWATS WILL ONCE AGAIN RISE TO NEAR OR SLIGHTLY ABOVE 2 INCHES ALONG THE BOUNDARY AS IT MOVES INTO WESTERN IOWA BY 00Z. UPPER LEVEL WIND FIELDS AGAIN SHOW A MODEST INCREASE AS A MODESTLY STRONG WAVE APPROACHES FROM THE SOUTHWEST WITH 0-6KM BULK SHEAR OVER 40 KTS ACROSS THE AREA. THIS SHOULD BE ENOUGH TO PROMOTE SEVERE STORMS DURING THE LATE AFTERNOON AND EVENING HOURS. ANOTHER ROUND OF STORMS WITH OVER AN INCH OF RAIN IN SOME OF THE HEAVIER STORMS IS EXPECTED. FINALLY...THE REMAINDER OF THE FORECAST SUGGESTS THAT A BREAK FROM THE ACTIVE WEATHER WILL RETURN FROM LATER ON MONDAY THROUGH WEDNESDAY...WITH SOME POTENTIAL FOR A QUICK MOVING STORM AGAIN BY THURSDAY. && .AVIATION...29/06Z ISSUED AT 1210 AM CDT FRI AUG 29 2014 ALL ELEMENTS WILL BE A CONCERN THROUGH THE PERIOD...ESPECIALLY OVERNIGHT. CONFIDENCE WILL BE LOW AS WELL DUE TO CONVECTION AND VARIABLE VSBYS AND CIGS. 05Z SURFACE ANALYSIS SHOWS WARM FRONT HAS LIFTED A BIT TOWARD THE MN BORDER WITH IFR/LIFR CONDITIONS IN THE VICINITY OVER NRN IA WHICH SHOULD PERSIST UNTIL TYPICAL DIURNAL RISES. ALSO EXPECT AT LEAST MVFR LIKELY ELSEWHERE DUE TO HIGH LOW LEVEL MOISTURE LEVELS. CENTRAL IA SHOWERS/STORMS SHOULD CONTINUE LIFTING N AND E THROUGH THE EARLY MORNING HOURS WITH ASSOCIATED DEGRADATIONS AS WELL. PRECIP SHOULD DIMINISH WITH RETURN OF VFR INTO MIDDAY...BUT ADDITIONAL CONVECTION MAY DEVELOP DURING THE AFTERNOON AND EARLY EVENING HOURS. NOTHING MORE THAN VFR VCSH WORDING UNTIL CONFIDENCE INCREASES HOWEVER. && .HYDROLOGY... ISSUED AT 315 PM CDT THU AUG 28 2014 SEVERAL ADDITIONAL EPISODES OF RAIN ARE EXPECTED THROUGH SATURDAY MORNING AND AGAIN ANOTHER SUNDAY AFTERNOON THROUGH MONDAY MORNING. AT THIS TIME EXPECTED RAINFALL AMOUNTS THROUGH SATURDAY MORNING WITH EACH EVENT SHOULD BE LIGHT TO MODERATE. THIS WILL LIMIT THE LIKELIHOOD OF FLASH FLOODING BUT STILL HAVE SOME EFFECT ON RISES ON SMALL STREAM AND AREA RIVERS. THERE IS A GREATER RISK OF MORE SUBSTANTIAL RAINFALL OVER PORTIONS OF THE FORECAST AREA SUNDAY EVENING. THIS TIME PERIOD WILL BE MONITORED FOR BOTH SHORT TERM FLOODING AND RIVER FLOODING OVER THE UPCOMING HOLIDAY WEEKEND. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LEE LONG TERM...REV AVIATION...SMALL HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1259 AM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 748 PM CDT THU AUG 28 2014 MADE SPATIOTEMPORAL ADJUSTMENTS OF POPS AND WX GRIDS BASED OFF RADAR TRENDS AS WELL AS HRRR GUIDANCE. CONVECTION IS STRUGGLING, AND NOT VERY CONFIDENT OF EASTWARD PROPAGATION GIVEN UPCOMING DECREASE IN DIURNAL INDUCED INSTABILITY AND LACK OF FORMIDABLE COLD POOL GENERATION FOR MCS LONGEVITY. 00Z KDDC RAOB IS CONSIDERABLY DRIER WITH A LOWER PWAT OF 1.03". && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 139 PM CDT THU AUG 28 2014 THERE IS A FRONT WHICH HAS BEEN NEARLY STATIONARY TODAY FROM JUST WEST OF TOPEKA SOUTH-SOUTHWEST TO NEAR ANTHONY, KS AND THEN FURTHER SOUTHWEST INTO SOUTHWESTERN OKLAHOMA. CONVECTION HAS BEEN ONGOING AND SPREADING OUT TODAY JUST EAST OF THIS CONVERGENCE BOUNDARY. ANOTHER SURFACE TROUGH IS QUICKLY MOVING EAST THROUGH OUR CWA, AND CROSSED DDC AT 1952Z. CLOUDS HAVE BEEN SLOWER TO CLEAR OUT IN OUR EASTERN CWA THAN IN THE WEST, BUT STILL THINK THERE WILL BE ENOUGH OF A CONVERCENCE BOUNDARY TO INITIATE SOME THUNDERSTORMS. AT THIS TIME, I DO NOT EXPECT ANY SEVERE STORMS, WITH THE NAM AND HRRR MODELS BOTH SHOWING AROUND 1200 TO 1400 J/KG OF MUCAPE THIS EVENING, AND THE BULK SHEAR VALUES IN THE 18 TO 22 KNOT RANGE. THERE IS A SMALL CHANCE FOR SOME SMALL HAIL AND DOWN BURST WINDS IN THE 50 MPH RANGE. I HAVE MIGRATED THE 50-60 PERCENT POPS FROM DDC TO PTT FROM 22Z TO 02Z. ALSO, THERE IS AN UPPER POOL OF COLD AIR COMING IN FROM COLORADO THIS EVENING, AND A FEW SHOWERS AND THUNDERSTORMS MAY TRIGGER OFF THE COLD POOL IN OUR WESTERN ZONES. THE HEAVIER RAIN CHANCES WILL BE IN OUR EASTERN 2-TIER OF COUNTIES, WHERE THE FRONT AND TROUGH ARE, DEW POINTS ARE MUCH HIGHER IN OUR EAST. I DO NOT EXPECT ANY POTENTIAL FLOODING PROBLEMS OF THE PAST TWO NIGHTS WHICH AFFECTED NESS, SCOTT AND TREGO COUNTIES. OVERNIGHT, THE UPPER COLD POOL WILL HELP TO DE-STABILIZE THE ATMOSPHERE, AND THE RAIN CHANCES WILL MOVE EAST TOWARDS MORNING, ALONG WITH THE UPPER COLD POOL. THE PRECIPITATION TYPE SHOULD BE MORE SHOWERY OVERNIGHT VERSUS THE THUNDERSTORM TYPE. WILL STILL MENTION THE CHANCE FOR SHOWERS AND ISOLATED THUNDER, BECAUSE IT WON`T TAKE MUCH OF AN UPDRAFT TO UPGRADE A SHOWER INTO A THUNDERSTORM. BY 12Z, MOST OF ANY CONVECTION WILL BE CONCENTRATED INTO OUR EASTERN ZONES, AND OUT OF OUR EASTERN ZONES BY 18Z FRIDAY. LOW TEMPERATURES TONIGHT SHOULD BE COOLER THAN LAST NIGHT, WITH MINS RANGING FROM THE UPPER 50S ALONG THE COLORADO BORDER TO THE MID 60S IN OUR EASTERN CWA FROM HAYS TO MEDICINE LODGE. FRIDAY`S TEMPERATURES SHOULD MATCH TODAY`S MAX TEMPS VERY SIMILARLY, AND BE BASICALLY IN THE MIDDLE TO UPPER 80S. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 205 PM CDT THU AUG 28 2014 MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH LIFTING NORTHEAST OUT OF THE CENTRAL PLAINS INTO THE UPPER MIDWEST SATURDAY WHILE WEAK UPPER LEVEL RIDGING BEGINS TO MOVE OUT OF THE ROCKIES INTO THE WESTERN HIGH PLAINS. ALONG WITH A FAIRLY WEAK FLOW ALOFT, DRIER CONDITIONS ARE LIKELY THROUGH LATE SATURDAY AFTERNOON. PRECIP CHANCES PICK UP A LITTLE SATURDAY NIGHT AS AN UPPER LEVEL TROUGH MOVES EAST-SOUTHEAST ACROSS THE PACIFIC NORTHWEST INTO THE GREAT BASIN REGION. A SERIES OF H5 VORT MAXIMA WILL BEGIN TO EJECT OUT OF THE ROCKIES INTO THE WESTERN HIGH PLAINS AS A LOW LEVEL SOUTHEASTERLY UPSLOPE FLOW SETS UP ACROSS EASTERN AND EXTREME WESTERN KANSAS. ALTHOUGH THE FLOW ALOFT WILL REMAIN FAIRLY WEAK, MODEST INSTABILITY WITH CAPE VALUES AROUND 500 TO 1000 J/KG AND FAVORABLE ENOUGH DIRECTIONAL SHEAR WILL BE PRESENT TO SUPPORT THE POTENTIAL FOR ISOLATED THUNDERSTORMS ACROSS THE HIGH PLAINS IN THE VICINITY OF A DEVELOPING LEE SIDE TROUGH. WIDESPREAD SEVERE IS UNLIKELY. PRECIP CHANCES MAY PICK UP A LITTLE MORE LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT AS AN OPEN SHORTWAVE TRANSITIONS EASTWARD ACROSS THE NORTHERN ROCKIES INTO INTO THE NORTHERN PLAINS. AN ATTENDANT COLD FRONT IS PROJECTED TO PUSH SOUTHEASTWARD INTO WESTERN KANSAS LATE IN THE DAY WHILE A PREVAILING SOUTHEASTERLY FLOW NEAR THE SURFACE CONTINUES TO DRAW MOISTURE UP INTO MUCH OF KANSAS. MEANWHILE, A +90KT UPPER LEVEL JET ASSOCIATED WITH THE OPEN WAVE IS PROJECTED TO DIG SOUTHEAST ACROSS THE NORTHERN ROCKIES NOSING INTO THE HIGH PLAINS OF WESTERN NEBRASKA AND POSSIBLY NORTHERN PORTIONS OF WESTERN KANSAS. AS A RESULT, THUNDERSTORMS ARE LIKELY TO FIRE UP ALONG AND AHEAD OF THE FRONT AS IT PUSHES EASTWARD INTO THE UPPER MIDWEST SUNDAY NIGHT. HOWEVER, THUNDERSTORM CHANCES MAY BE MORE LIMITED FURTHER SOUTH ALONG THE FRONT INTO KANSAS WITH WEAKER DYNAMIC SUPPORT ALOFT. THE BETTER CHANCE FOR CONVECTION WILL REMAIN ACROSS OUR NORTHEAST IN CENTRAL KANSAS WHERE LOW LEVEL FORCING WILL BE MORE IDEAL NORTHEAST OF A DEVELOPING SURFACE LOW ACROSS EXTREME SOUTHWEST KANSAS. ALTHOUGH LESS CERTAIN, THUNDERSTORMS MAY BE POSSIBLE AGAIN MONDAY NIGHT INTO EARLY TUESDAY AS THE AFOREMENTIONED COLD FRONT IS FORECAST TO STALL OUT SOMEWHERE GENERALLY ALONG THE OKLAHOMA BORDER. TEMPERATURES ARE EXPECTED TO BE NEAR THE SEASONAL SATURDAY AS SURFACE PRESSURE BEGINS TO FALL ACROSS EASTERN COLORADO. ALTHOUGH THIS WILL HELP QUICKLY RETURN A LOW LEVEL SOUTHEASTERLY FLOW TO WESTERN KANSAS BY SATURDAY AFTERNOON, LITTLE CHANGE IS EXPECTED TO THE OVERALL AIR MASS IN PLACE ACROSS THE REGION. LOOK FOR HIGHS ONLY UP INTO THE MID TO UPPER 80S(F) IN CENTRAL KANSAS WITH THE LOWER 90S(F) POSSIBLE IN EXTREME SOUTHWEST KANSAS WHERE SOME WARM AIR ADVECTION IS LIKELY BY SATURDAY AFTERNOON. THE WARMING TREND WILL CONTINUE INTO SUNDAY AS THE PREVAILING SOUTHERLY FLOW DRAWS WARMER AIR NORTHWARD. WIDESPREAD 90S(F) ARE LIKELY TO FINISH OUT THE WEEKEND AS A RESULT. COOLER TEMPERATURES ARRIVE MONDAY IN WAKE OF A COLD FRONT PUSHING THROUGH WESTERN KANSAS BY MID DAY DROPPING HIGHS BACK DOWN INTO THE 80S(F) TO START THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1258 AM CDT FRI AUG 29 2014 NUMEROUS SHOWERS AND A FEW OCCASIONAL LIGHTNING STRIKES WILL AFFECT THE HAYS TERMINAL OVER THE NEXT ONE TO POSSIBLY TWO HOURS AS AN UPPER LOW MOVES THROUGH THE HIGH PLAINS REGION. POST FRONTAL SURFACE WINDS WILL REMAIN LIGHT AND OUT OF THE NORTH UNTIL AT LEAST MID AFTERNOON FRIDY AT ALL TERMINAL LOCATIONS. && .PRELIMINARY POINT TEMPS/POPS... DDC 61 90 68 95 / 10 10 10 20 GCK 59 91 67 95 / 10 10 10 20 EHA 61 91 67 97 / 10 10 10 10 LBL 61 91 68 97 / 10 10 10 10 HYS 61 89 68 93 / 10 10 10 40 P28 66 90 69 95 / 10 10 10 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SUGDEN SHORT TERM...BURKE LONG TERM...JJOHNSON AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
215 AM EDT FRI AUG 29 2014 .SYNOPSIS... A WEAK COLD FRONT SETTLES SOUTH INTO NORTH CAROLINA OVERNIGHT INTO FRIDAY...BEFORE LIFTING NORTH AS A WARM FRONT FRIDAY NIGHT AND SATURDAY. A WEAK TROUGH DEVELOPS ON SUNDAY AND SHOULD RESULT IN INCREASING PRECIPITATION CHANCES LATER IN THE DAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... WK SFC BNDRY RMNS DRAPED FM ALG THE VA/NC BORDER IN SRN/SE VA...TO WCNTRL VA. ISOLD/SCT CONVECTION CONTS TO TRACK SLOLY SE THROUGH AREAS OF THE PIEDMONT W OF I 95. DEWPTS RMN FM THE U60S TO L70S S ALONG/S OF THAT BNDRY...AND MNLY IN THE L60S N (ALONG NNE WNDS). 00Z/29 RUC CONT TO PUSH THAT CONVECTION TO THE SE INTO NE NC AFT MIDNIGHT AS THE BNDRY SINKS S. WILL KEEP POPS FOR THOSE AREAS UNTIL AFT MDNGT...ELSW JUST CLR-PC. MAY NEED TO ADD FOG OVR SRN AREAS OF THE FA...THOUGH XPCG A GRADUAL LWRG OF DEWPTS FM THE NNE AS THE BNDRY SINKS TO THE S. LO TEMPS FM THE L60S N TO THE U60S/ARND 70F S. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... A WEAK FRONTAL BOUNDARY REMAINS STALLED ACROSS NRN NC FRIDAY AS A SFC HIGH PRESSURE OVER NEW ENGLAND EXTENDS SWD INTO THE MID ATLANTIC REGION. ONCE AGAIN...THE WEAK FRONTAL BOUNDARY SHOULD PROVIDE JUST ENOUGH FORCING/INSTABILITY FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS INVOF THE STALLED FRONT (STILL PRIMARILY SOUTH OF INTERSTATE 64 WITH BEST PRECIP CHANCES ALONG THE VA/NC BORDER INTO NE NC). THE AXIS OF THE SFC HIGH SITS OVER CNTRL NY TO CNTRL VA FRIDAY MORNING AND THEN PIVOTS EWD ALONG THE COAST FROM NC TO NEW ENGLAND BY FRIDAY EVENING. THIS WILL BRING A SLIGHTLY COOLER AIRMASS ACROSS THE NRN HALF OF THE CWA WHILE TEMPS STAY ON THE COOLER SIDE INVOF THE FRONT DUE TO PARTLY TO MOSTLY CLOUDY SKIES. IT IS DIFFICULT TO SAY EXACTLY WHERE THE DIVIDING LINE WILL SET-UP BTWN HIGHS IN THE MID-UPPER 80S SW TO LOW-MID 80S NE. CURRENT FORECAST THINKING GENERALLY KEEPS THE COOLER HIGHS ACROSS THE NRN NECK/MD LOWER EASTERN SHORE/ACCOMACK COUNTY VA...DESPITE MOSTLY SUNNY SKIES ACROSS THESE AREAS. THE STALLED BOUNDARY LIFTS NWD AS A WARM FRONT FRIDAY NIGHT INTO SATURDAY AS THE SFC HIGH OVER NEW ENGLAND SLIDES OFF THE NEW ENGLAND COAST LATE FRIDAY NIGHT INTO SATURDAY. AS IT DOES SO... WILL NEED TO CARRY SLIGHT CHC POPS ACROSS MUCH OF THE FA FRIDAY NIGHT...WITH THE BEST CHANCES FOR PRECIPITATION (STILL IN THE 20 PERCENT RANGE) ALONG AND N-NE OF INTERSTATE 64 DURING MOST OF SATURDAY. RETURN FLOW ALSO DEVELOPS ON SATURDAY AS THE RIDGE AXIS MOVES OFFSHORE...BRINGING WARMER TEMPS AND A MORE HUMID AIRMASS INTO THE REGION. LOWS FRIDAY NIGHT IN THE LOW-MID 60S NORTH AND UPPER 60S TO LOWER 70S SOUTH. HIGHS SATURDAY AROUND 90/MID-UPPER 80S IMMEDIATE COAST. A GENERALLY DRY FORECAST FOR SATURDAY NIGHT INTO THE FIRST HALF OF SUNDAY AS HIGH PRESSURE DOMINATES AT THE SFC AND ALOFT. LOWS SATURDAY NIGHT AROUND 70 UNDER PARTLY CLOUDY SKIES. A WEAK TROUGH DEVELOPS ALONG THE LEE OF THE APPALACHIANS ON SUNDAY AND MAY BE JUST ENOUGH OF A FOCUSING MECHANISM FOR SHOWERS AND THUNDERSTORMS DURING THE AFTN/EVENING AS WEAK SHORTWAVE ENERGY STREAMS ALONG THE PERIPHERY OF AN UPPER LEVEL RIDGE...WHICH SHOULD BE CENTERED OVER THE WRN ATLANTIC AS A BERMUDA HIGH. MID-RANGE MODEL SOLUTIONS VARY REGARDING OVERALL PRECIPITATION PLACEMENT... BUT THE GENERAL TREND HAS HIGHER POPS OF 30-40 PERCENT ALONG AND NW OF A LINE FROM AVC-RIC-SBY AND LOWER POPS AROUND 20 PERCENT ACROSS NE NC/FAR SE VA. TEMPERATURES REMAIN WARM IN THE PERSISTENT RETURN FLOW WITH HIGHS ONCE AGAIN AROUND 90/MID-UPPER 80S IMMEDIATE COAST. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... SUMMER-LIKE PATTERN WILL TEND TO PREVAIL THROUGH THE MEDIUM RANGE PERIOD AS MID/UPPER LEVEL RIDGING CENTERED ALONG/OFF THE SE US COAST...GRADUALLY SHIFTS TO THE WSW AND BECOMES ANCHORED OVER THE DEEP SOUTH/GULF COAST REGION. TEMPERATURES WILL GENLY RUN ABOUT 5 F ABOVE AVG WITH HIGHS INTO THE UPPER 80S TO LOWER 90S AND LOWS IN THE UPPER 60S TO LOWER/MID 70S. A COUPLE OF WEAK MID LEVEL SHORTWAVES WILL BRING SOMEWHAT HIGHER POPS TO THE AREA FOR LABOR DAY...WILL CARRY 40% POPS THROUGHOUT...FOLLOWED BY POPS ONLY ~20% ON TUE IN BETWEEN THE DEPARTING WAVE AND A COLD FRONT APPROACHING FROM THE NW. TUE LIKELY THE HOTTEST DAY..WITH MOST LOCATIONS GETTING ABOVE 90 F AND PERHAPS INTO THE MID 90S OVER THE INTERIOR. ANOTHER ROUND OF SOMEWHAT HIGH POPS IS SLATED FOR TUE EVENING/TUE NIGHT AS THE COLD FRONT MOVES CLOSER TO THE LOCAL AREA AND HEIGHTS ALOFT DROP AS THE RIDGE BREAKS DOWN. BY LATE WED-THU...A GENERAL CONSENSUS OF THE GFS/ECMWF/WPC FORECAST DOES PUSH A SFC COLD FRONT SOUTH OF THE AREA WITH HIGH PRESSURE BUILDING ACRS THE NE CONUS. THIS SHOULD ALLOW SLIGHTLY COOLER/DRIER AIR TO MOVE INTO THE REGION...BUT THE FRONT DOES NOT LOOKS VERY STRONG SO HIGHS WILL STILL AVG IN THE MID-UPPER 80S ON THU. WILL FOCUS HIGHEST POPS WED-THU ACRS THE SOUTH (20-30%) WITH GENLY A DRY FORECAST ACRS THE ERN SHORE. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE FRONT HAS STALL JUST SOUTH OF THE AREA AND A BAND OF SHOWERS AND THUNDERSTORMS HAS FORMED JUST ON THE NORTH SIDE OF THE FRONT. THIS CONVECTION IS SLOWLY SLIDING SE AND LOOKS LIKE IT WILL MISS ECG...BUT IS PROVIDING SOME OVERCAST CONDITIONS FOR PHF/ORF/ECG. THIS CLOUD COVER SHOULD KEEP ANY GROUND FOG FROM FORMING. SBY IS DEEPER INTO THE DRIER AIR MASS TO THE NORTH AND IS CLEAR TO BEGIN THE PERIOD. THIS LOOKS LIKELY TO CONTINUE THROUGH THE OVERNIGHT HOURS. ON FRIDAY...THE FRONTAL BOUNDARY WILL BEGIN TO LIFT BACK NORTH AS A WARM FRONT. THE MODELS DIFFER ON HOW MUCH CLOUD COVER WILL EXIST...BUT CEILINGS SHOULD REMAIN AROUND 5K TO 8K FT. FOR NOW HAVE ALLOWED FOR A BKN CEILING DURING THE AFTERNOON HOURS ACROSS VA INTO NE NC. FURTHER NORTH NEAR SBY HAVE JUST ALLOWED FOR SOME SCATTERED CU TO FORM. THE MID DECK CLOUDS CONTINUE ACROSS VA AND NERN NC TONIGHT AS THE FRONT SLOWLY EDGES NORTHWARD. BUT AT THIS POINT...ALL CEILINGS SHOULD REMAIN IN THE VFR RANGE. OUTLOOK...MAINLY DRY WEATHER WITH CONTINUED VFR CONDITIONS EXPECTED FRIDAY AND THROUGH MUCH OF THE UPCOMING HOLIDAY WEEKEND. SLIGHT TO LOW CHANCE POPS FOR AFTN/EVENING TSTMS SUNDAY EVENING INCREASE TO 30 TO 40 PERCENT MONDAY AHEAD OF THE NEXT FRONTAL PASSAGE. OTHERWISE, SOME POTENTIAL FOR FOG OR LOW CLOUDS WILL EXIST EACH DAY WITHIN A FEW HOURS OF SUNRISE. && .MARINE... CRISTOBAL NOW >500 NM ENE OF THE LOCAL AREA...WITH A WEAK SFC BOUNDARY HAVE PUSHED SOUTH OF THE WATERS. N/NE WINDS AVG AROUND 10 KT...WILL LIKELY INCREASE A BIT LATER TONIGHT AS MODEST PUSH OF COOLER AIR MOVES OVER THE WATERS WITH SFC HIGH PRESSURE MOVING ESE FROM MICHIGAN INTO THE NE AND NRN MID ATLC REGION. AS FOR HEADLINES...WILL MAINTAIN SCHS HEADLINE FOR COASTAL WATERS N OF PARRAMORE ISLAND THROUGH 10PM...WITH NO HEADLINES ELSEWHERE EVEN THOUGH THERE WILL BE SOME INCREASE IN WINDS OVER THE BAY OVERNIGHT INTO EARLY FRI. (MUCH LIKE WHAT OCCURRED EARLIER TODAY). N/NE WINDS WILL SLOWLY VEER TO THE E/NE IN THE AFTN AND AVG 10-15 KT ACRS THE LOWER BAY AND SOUTHERN COASTAL WATERS TO 5-10 KT FARTHER NORTH. SEAS WILL GENLY ONLY BE AROUND 3 FT...BUT WILL GENLY STILL HAVE A MODERATE RISK FOR RIP CURRENTS ALONG AREA BEACHES AS ENERGY FROM CRISTOBAL IS SLOW TO DIMINISH. WINDS THEN GRADUALLY VEER AND BECOME SE AND GRADUALLY INCREASE BY SATURDAY AFTN/EVENING. WINDS THEN BECOME S/SW SUNDAY. SEAS WILL GENERALLY RUN 3 FT OR LESS BUT MAY INCREASE TO 4 FT IN THE OUTER PORTION OF 20NM LATE SATURDAY AND SUNDAY...WITH A PERIOD OF 2-3 FT WAVES IN THE BAY SAT NIGHT. FAIRLY QUIET (OUTSIDE OF CONVECTION) INTO EARLY NEXT WEEK WITH SEAS 2-3 FT AND WAVES 1-2 FT OR LESS AS SFC HIGH REMAINS ANCHORED OFFSHORE AND NO SIGNIFICANT FRONTS MOVE INTO THE AREA UNTIL LATE TUE/WED. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100. MARINE...NONE. && $$ SYNOPSIS...ALB/BMD/JDM NEAR TERM...ALB/BMD SHORT TERM...BMD LONG TERM...LKB AVIATION...ESS MARINE...LKB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
431 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT FRI AUG 29 2014 RATHER UGLY MORNING OUT THERE IN TERMS OF AVIATION...WITH PLENTIFUL AMOUNTS OF LOW CIGS AND FOG OUT AHEAD OF A WARM FRONT THAT WAS STARTING TO MAKE PROGRESS NORTH INTO MN AND AT 3 AM WAS NEAR THE I-90 CORRIDOR. BESIDE THE LOW CLOUDS...ISENTROPIC LIFT AND ELEVATED INSTABILITY ADVECTION ASSOCIATED WITH A MODEST 20-30 KT SWRLY LLJ HAS ALLOWED FOR AN AREA SHOWERS/THUNDERSTORMS TO MOVE NNE ACROSS THE AREA. THE HRRR HAS HAD A GOOD HANDEL ON THIS ACTIVITY OVERNIGHT...AND FOLLOWED IT FAIRLY CLOSELY TO TIME THIS MORNINGS BATCH OF ACTIVITY THROUGH THE AREA. THIS BATCH OF RAIN LOOKS TO BE MOSTLY NORTH OF THE MPX AREA BY 15Z...WITH A BRIEF BREAK IN PRECIP EXPECTED UNTIL THUNDERSTORMS GET GOING AGAIN LATER IN THE AFTERNOON. FOR THE AFTERNOON...WE WILL BE DEALING WITH A RATHER MESSY SFC PATTERN AS THE MESO LOW CURRENTLY NEAR SIOUX FALLS WASHES OUT OVER MN AS IT GETS ABSORBED BY THE MAIN COLD FRONT...WHICH WAS STILL BACK ACROSS WRN NODAK. BIGGEST CHANGE SEEN FROM THE 28.12 TO THE 29.00 MODEL RUNS WAS A WHOLESALE SLOWING OF THE FRONT/SFC TROUGH ACROSS THE AREA. THIS HAS RESULTED IN HIGHER POPS BEING PUSHED BACK WEST THIS AFTERNOON...AS WHAT WAS LOOKING LIKE WAS MAINLY GOING TO BE A SHOW FOR AREAS ALONG/EAST OF I-35 IS NOW MORE OF AN ALONG/EAST OF A ST. CLOUD TO FAIRMONT LINE. THE HI-RES MODELS THAT LOOK TO ADHERE TO WHAT IS SEEN FORCING WISE WITH THE DETERMINISTIC MODELS THE BEST ARE THE 29.00 NMM AND MPX WRFS...WHICH BOTH SHOW STORMS FORMING WEST OF THE TWIN CITIES BETWEEN 19-21Z AND MOVING EAST FROM THERE AS A BROKEN LINE OF STORMS. ONE THING THAT HAS NOT CHANGED...IS THE MOST WIDESPREAD RAIN/HIGHEST AMOUNTS LOOK TO FALL ACROSS SE MN/WRN WI AS THE AFTERNOON ACTIVITY TO THE WEST OF I-35 CONGEALS INTO A BROADER MASS EAST OF I-35. STILL NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER TODAY EITHER...AS CLOUD COVER LOOKS TO BE EXTENSIVE...WHICH WILL LIMIT THE DEGREE OF DESTABILIZATION WE SEE BY THE AFTERNOON. IN ADDITION...MID LEVEL LAPSE RATES WILL REMAIN RATHER WEAK...FURTHER POINTING TO INSTABILITY SOMEWHAT LACKING WHEN IT COMES TO THE SEVERE WEATHER POTENTIAL. BESIDE THE INSTABILITY...THE SFC PATTERN LOOKS TO BE RATHER DIFFUSE...WITH NO CLEAR FOCUS EXISTING FOR THUNDERSTORM ACTIVITY /SEE FRONT SUNDAY FOR A CLEAR FOCUS FOR THUNDERSTORM DEVELOPMENT/. WITH THAT SAID...BULK SHEAR WILL BE UP IN THE 30-40 KT RANGE AHEAD OF THE SFC TROUGH...SUFFICIENT ENOUGH TO ALLOW FOR A MULTI-CELL CLUSTER OR TWO TO PULSE UP ENOUGH TO POSE AN ISOLATED WIND/HAIL THREAT TODAY. FOR HIGHS TODAY...THERE IS ADMITTEDLY SOME BUST POTENTIAL WITH THE CURRENT FORECAST OF HIGHS IN THE 70S AS THAT IS PREDICATED ON CLOUD COVER BEING DOMINATE TODAY. IF WE INSTEAD GET SOME DECENT SUN BEFORE STORMS DEVELOP THIS AFTERNOON...THEN HIGHS IN THE LOWER/MID 80S WILL BE MORE COMMON. FOR TONIGHT...SHOWER AND THUNDERSTORM ACTIVITY LOOKS SLOWLY CLEAR OUT TO THE EAST...WITH TO MUCH LEFT OUTSIDE OF SOME DRIZZLE IN WRN WI BY 12Z SATURDAY. HOWEVER...THE SFC THROUGH/FRONT WILL BE VERY SLOW IN WORKING ACROSS THE AREA...WITH PLENTIFUL LOW LEVEL MOISTURE LOOKING TO HANG AROUND MOST OF THE NIGHT. THIS SHOULD ALLOW FOR ANOTHER ROUND OF LOW STRATUS AND FOG TO EXPAND ACROSS THE AREA TONIGHT...WHICH IN TURN WILL HELP KEEP LOWS UP MAINLY IN THE MID/UPPER 60S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 338 AM CDT FRI AUG 29 2014 THE MAIN STORY IN THE EXTENDED IS THE SYSTEM EXPECTED SUNDAY AFTERNOON AND SUNDAY NIGHT WITH THE HIGH LIKELIHOOD OF WIDESPREAD THUNDERSTORMS AND THE POTENTIAL FOR SEVERE WEATHER. THE RAIN SHOULD CLEAR EARLY ON LABOR DAY...LEAVING MAINLY DRY WEATHER ACROSS THE FORECAST AREA THROUGH AT LEAST MID WEEK. THE TROUGH EXPECTED TO MOVE ACROSS THE NORTHERN CONUS SUN-MON AND BRING WIDESPREAD THUNDERSTORMS TO THE NATION`S MID SECTION IS ALREADY AN ESTABLISHED CIRCULATION WITH A WELL-DEFINED PV FEATURE IN THE GULF OF ALASKA THIS MORNING. THE TROUGH WILL DIG SOUTHEAST OVER THE NEXT 48 HOURS AND DEVELOP MORE OF A NEGATIVE TILT BEFORE LIFTING NORTH TOWARD HUDSON BAY MONDAY NIGHT. THE JET STRUCTURE SUPPORTS WIDESPREAD UPPER DIVERGENCE AND 500MB 12-HR HEIGHT FALLS BETWEEN 80-100M SLIP ACROSS NORTHERN MN SUNDAY NIGHT. LOWER IN THE ATMOSPHERE...850-700MB FGEN INCREASES IN WESTERN MN NEAR OR JUST AFTER 18Z ON SUNDAY. THE BOUNDARY MAKES GRADUAL PROGRESS TO THE EAST FROM 18Z SUNDAY UNTIL 12Z MONDAY. A SLOWLY DEEPENING AND EASTWARD-MOVING SURFACE CYCLONE PRODUCES 4-6MB 6-HR MSLP PRESSURE FALLS ACROSS THE FORECAST AREA ON SUNDAY. CONVECTIVE INITIATION SHOULD NOT BE A PROBLEM...IN FACT...STORMS SHOULD ALREADY BE ONGOING IN THE EASTERN DAKOTAS SATURDAY MORNING. ELEVATED CONVECTION SHOULD TRANSITION TO MORE SURFACE BASED CONVECTION WITH HEATING AND THE LIKELY ESTABLISHMENT OF LARGE LINE SEGMENTS OR CLUSTERS OF THUNDERSTORMS DUE TO THE LARGE-SCALE FORCING. THE DEEP LAYER SHEAR SHOULD BE GOOD ENOUGH TO ORGANIZE STORMS INTO MULTCELL WITH EMBEDDED SUPERCELLS /EVEN IF THEY EXIST IN LINES/. THE INSTABILITY SHOULD BE SUFFICIENT TO SUPPORT STRONG UPDRAFTS. IT LOOKS PRIMARILY LIKE A WIND AND HAIL THREAT IN THE AFTERNOON AND EVENING HOURS ACROSS MN. BOTH THE NAM AND GFS HAVE 0-3KM SHEAR ON THE ORDER OF 25-40KTS FROM 18Z-06Z ACROSS THE FORECAST AREA. THE SEVERE THREAT DIMINISHES IN WI GIVEN THE LOSS OF INSTABILITY SUNDAY NIGHT AND QUICKLY NORTHWARD LIFTING SURFACE LOW. BEYOND THE WEEKEND...THE TROUGH FLATTENS OUT AND WE`RE LEFT WITH A RELATIVELY DRY AND COOL WESTERLY FLOW PATTERN THROUGH AT LEAST MID WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1155 PM CDT THU AUG 28 2014 IFR OR LIFR CONDITIONS WILL PERSIST THROUGH THE OVERNIGHT AND INTO AT LEAST MID MORNING FRIDAY...WITH THE WORST CONDITIONS ACROSS SOUTHERN AND WESTERN MINNESOTA. MODELS SHOW A SOMEWHAT RAPID IMPROVEMENT BY LATE MORNING...BUT AM A BIT SKEPTICAL GIVEN THE AMPLE LOW LEVEL MOISTURE IN PLACE. WILL NEED TO WATCH TRENDS OVERNIGHT. SCATTERED SHOWERS WILL ALSO CONTINUE TONIGHT...BECOMING A BIT MORE WIDESPREAD ACROSS ERN MN AND WRN WI FRIDAY AFTERNOON. KMSP...CIGS HAVE HAD A HARD TIME MAINTAINING IFR STATUS THIS EVENING...BUT SURROUNDING OBS CONTINUE TO DETERIORATE AND BELIEVE IT WON/T BE TOO MUCH LONGER THAT MSP WILL FINALLY JOIN THE IFR CLUB. IMPROVEMENTS ARE CURRENTLY FORECAST BY LATE MORNING...BUT AS ALLUDED TO ABOVE THIS MAY BE A BIT TOO OPTIMISTIC. /OUTLOOK FOR KMSP/ SAT...VFR. WIND NNE AT 5-10 KTS. SUN...VFR WITH MVFR/TSRA LATE. WINDS SSE AT 10KTS. MON...VFR WITH MVFR/TSRA EARLY. WINDS W 10-15KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
325 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 THE PRIMARY FORECAST CHALLENGES WILL BE IN REGARDS TO PCPN CHANCES TODAY INTO TONIGHT AND THEN TIMING THE NEXT ROUND OF CONVECTION SUNDAY INTO SUNDAY NIGHT. SOME SEVERE STORMS WILL BE POSSIBLE MAINLY FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING. MAIN FEATURES FROM THE UPPER AIR CHARTS LAST EVENING INCLUDED THE FOLLOWING. AT 300 MB A JET SEGMENT OF AROUND 70 KNOTS WAS PUNCHING NORTHEAST FROM SOUTHWEST KS. THIS WAS AHEAD OF A 500 MB TROUGH THAT STRETCHED FROM THE DAKOTAS DOWN INTO WEST TEXAS. 12 HOUR HEIGHT FALLS OF UP TO AROUND 40 METERS WERE NOTED AT AMARILLO AND DODGE CITY. DECENT MOISTURE WAS STILL IN PLACE AT 700 MB AND 850 MB AHEAD OF THE MID LEVEL TROUGH. THE KOAX SOUNDING WAS STILL FAIRLY MOIST WITH 1.70 PRECIPITABLE WATER. SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER SOUTHEAST SOUTH DAKOTA AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW INTO WEST TEXAS. DEWPOINTS WERE IN THE 60S TO LOWER 70S. WATER VAPOR LOOP EARLY THIS MORNING SHOWED THAT THE TROUGH TO OUR WEST HAD MADE SOME EASTWARD PROGRESS SINCE LAST EVENING. IT SHOULD CONTINUE TO HAVE AN IMPACT ON US UNTIL A LITTLE AFTER MIDNIGHT TONIGHT. KEPT FAIRLY HIGH POPS GOING TODAY...SINCE WE SHOULD SEE REDEVELOPMENT THIS AFTERNOON WITH DAYTIME HEATING. FORECAST SOUNDINGS FROM THE 00Z NAM INDICATED ELEVATED INSTABILITY OF OVER 2000 J/KG BY AROUND NOON. RECENT RUNS OF THE RAP MODEL SHOW AN INCREASE IN PCPN COVERAGE AFTER 1 PM. HIGHS WILL BE MAINLY IN THE UPPER 70S AND LOWER 80S. LOWS TONIGHT SHOULD DROP TO THE LOWER AND MID 60S AS DRIER AIR WORKS ITS WAY IN FROM THE NORTHWEST BEHIND THE COLD FRONT. SOME PATCHY FOG COULD DEVELOP LATE TONIGHT...BUT OVERALL THE ATMOSPHERE WILL BE DRYING OUT. SATURDAY LOOKS LIKE A DECENT DAY WITH A FAIR AMOUNT OF SUNSHINE AND HIGHS IN THE 80S. CLOUDS WILL START TO INCREASE SATURDAY NIGHT... ESPECIALLY IN OUR FAR WESTERN ZONES. KEPT A SMALL CHANCE OF LATE NIGHT TSTMS IN NORTHEAST NEBRASKA. MODELS HAVE SOME TIMING DIFFERENCES FOR SUNDAY INTO SUNDAY NIGHT. KEPT SOME LOW POPS LATE SATURDAY NIGHT WEST OF A LINE FROM WAYNE TO COLUMBUS. 00Z RUNS OF THE NAM AND CANADIAN MODEL WERE A BIT SLOWER WITH DEVELOPMENT OF STORMS SUNDAY AFTERNOON. FOR NOW...BLENDED IN SOME OF THE GFS AND ECMWF WHICH SHOW SOME RAINFALL AMOUNTS OVER A QUARTER OF AN INCH SUNDAY AFTERNOON. IF THE NAM IS MORE CORRECT... THE SEVERE WEATHER POTENTIAL IS PROBABLY HIGHER SUNDAY EVENING THAN IF THE GFS AND ECMWF VERIFY BETTER. LOOK FOR HIGHS MAINLY IN THE 80S AND MAYBE NEAR 90 FOR PARTS OF SOUTHEAST NEBRASKA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 TRENDED POPS DOWNWARD SUNDAY NIGHT FROM NORTHWEST TO SOUTHEAST AS THE SYSTEM MOVES THROUGH...BUT LINGERED A SLIGHT CHANCE OF TSTMS INTO MONDAY MORNING. A 500 MB LONGWAVE TROUGH AXIS WILL BE LOCATED OVER THE EASTERN ROCKIES AND WESTERN HIGH PLAINS AT THE BEGINNING OF THIS PERIOD. BY TUESDAY...THAT SHIFTS EAST OF OUR AREA AND THEN THE FLOW IS FAIRLY ZONAL ACROSS MID AMERICA INTO WEDNESDAY. LATER IN THE WEEK ANOTHER TROUGH WILL DIG INTO THE PACIFIC NORTHWEST...WITH OUR AREA UNDER THE INFLUENCE OF SOUTHWEST MID LEVEL FLOW. ALTHOUGH THUNDERSTORM CHANCES WILL NOT BE COMPLETELY ABSENT...NEXT WEEK SHOULD BE A LOT DRIER THAN THIS WEEK HAS BEEN. HIGHS WILL MODERATE FROM MAINLY 80S TO AROUND 90 AND LOWS WILL INCREASE FROM 60S TO AROUND 70 OR THE LOWER 70S. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1137 PM CDT THU AUG 28 2014 CONVECTION AROUND OR DEVELOPING IN THE AREA WILL AFFECT KOFK THROUGH ABOUT 08Z...KLNK THROUGH ABOUT 10Z...AND KOMA 08-12Z. OTHERWISE...VFR CONDITIONS EARLY IN THE PERIOD...BUT COULD SEE TEMPORARY MVFR CONDITIONS AT ALL THREE TAF SITES 10-15Z...WITH TEMPORARY IFR CONDITIONS POSSIBLE AT KOFK. COULD ALSO SEE AN ADDITIONAL 30 PERCENT CHANCE OF OF SHOWERS/THUNDERSTORMS AT KLNK/KOMA 16-22Z. WEAK WIND SHIFT FROM SOUTHEAST TO NORTHWEST THROUGH THE PERIOD AS WELL. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1257 AM CDT FRI AUG 29 2014 .SHORT TERM...(THIS EVENING THROUGH TONIGHT) ISSUED AT 309 PM CDT THU AUG 28 2014 THE PRIMARY FORECAST CONCERN THROUGH TONIGHT WILL ONCE AGAIN CENTER AROUND THE CHANCE OF THUNDERSTORMS...LOCALLY HEAVY RAINFALL...AND POSSIBLE FLOODING. SHOWERS AND THUNDERSTORMS SHOULD BE LESS WIDESPREAD AND OVERALL LESS HEAVY THAN WHAT WE SAW LAST NIGHT. THE PRIMARY TRIGGERING MECHANISM CONTINUES TO BE AN UPPER LEVEL TROUGH THAT HAS VERY SLOWLY BEEN SLIDING EAST ACROSS NEBRASKA. THE 500 MB TROUGH AXIS WILL EVENTUALLY SLIDE EAST INTO OUR CWA BY DAWN. AS LONG AS WE ARE OUT AHEAD OF THIS TROUGH AXIS WE WILL SEE AT LEAST SOME CHANCE OF SHOWERS AND THUNDERSTORMS...WHICH WILL BE THE CASE THROUGH THE NIGHT. THE 18Z NAM AND A RUN OR TWO OF THE HRRR ARE NOW HINTING AT THE POSSIBILITY OF SOME ELEVATED THUNDERSTORMS FORMING WITHIN A FEW HOURS AFTER SUNSET AROUND HIGHWAY 281 OR A LITTLE EAST OF HIGHWAY 281. IF THESE STORMS FORM THEY WILL TRACK NORTHEAST AND COULD BE HEAVY RAIN PRODUCERS WITH AN OUTSIDE CHANCE OF A LOW END SEVERE HAIL OR WIND EVENT. INSTABILITY HAS BEEN RATHER LOW TODAY DUE TO THE EXTENSIVE CLOUD COVER...WHICH IS THE PRIMARY LIMITING FACTOR FOR SEVERE POTENTIAL. IN ADDITION...THE DEEP LAYER WIND SHEAR IS ONLY AROUND 30 KTS...WHICH IS WEAK TO MODEST AND CERTAINLY NOT OVERLY IMPRESSIVE FOR SEVERE POTENTIAL. THEREFORE...GIVEN A FAIRLY SIMILAR MOIST ENVIRONMENT TO LAST NIGHT BEING LOCATED OUT AHEAD OF THE UPPER TROUGH...WITH JUST A BIT LESS LIFT OUR PRIMARY CONCERN WILL REALLY CONTINUE TO BE HEAVY RAIN...BUT JUST LIKELY NOT AS WIDESPREAD AS THE OTHER NIGHT. THE GROUND IS VERY SATURATED ACROSS PRETTY MUCH OUR ENTIRE FORECAST AREA SO ANY HEAVY RAIN WILL RESULT IN RUNOFF AND POSSIBLE FLOODING. AM MOST CONCERNED FOR THE AREA ALONG AND EAST OF HIGHWAY 281 BASED ON THE LATEST 18Z NAM. OVERALL...THE PROBABILITY OF RAIN IS LOWER TONIGHT THAN LAST NIGHT GIVEN THAT THE COVERAGE AREA WILL BE LESS AND IT IS HARD TO PIN POINT EXACTLY WHERE THE THUNDERSTORMS WILL DEVELOP WITHIN THE MORE BROAD FAVORABLE ZONE. .LONG TERM...(FRIDAY THROUGH THURSDAY) ISSUED AT 309 PM CDT THU AUG 28 2014 FORECAST FOCUS IS ON THE CHANCES OF STORMS FRIDAY AND THEN CHANCES OF SEVERE STORMS ON SUNDAY. MODELS ARE IN GOOD AGREEMENT WITH MOVING AND TIMING OF MAJOR FEATURES AT LEAST THROUGH MONDAY. IN GENERAL THE ATMOSPHERE IS FORECAST TO MORPH FROM A CUTOFF LOW PATTERN BACK TO A MORE ZONAL FLOW...SO OUT OF A HEAVY RAIN PATTERN AND BACK INTO A SEVERE WEATHER TYPE REGIME. THE LOW PRESSURE AREA THAT HAD BEEN PARKED OVER THE CENTRAL ROCKIES THE LAST SEVERAL DAYS WILL EJECT EASTWARD ON FRIDAY AND LEAVE DRY WEATHER BEHIND. AS IT MOVES THROUGH THERE WILL BE A THREAT OF STORMS...BUT MAINLY OVER THE EASTERN THIRD OF THE AREA ON FRIDAY AFTERNOON AND EARLY EVENING. A RIDGE BUILDS OVER THE AREA ON SATURDAY BRINGING THE FIRST DRY AND WARM DAY IN QUITE A WHILE. LOW CHANCES OF STORMS ARE BACK IN THE FORECAST FOR SATURDAY NIGHT AND SUNDAY MORNING WITH A WEAK WAVE MOVING ACROSS THE AREA. HOWEVER...THE CHANCE OF STORMS FROM MID DAY SUNDAY INTO THE EVENING IS MORE IMPRESSIVE. A COLD FRONT AND FAIRLY STRONG MID LEVEL WAVE MOVE THROUGH DURING THAT TIME FRAME. MOST MODELS ARE IN AGREEMENT WITH THE THE TIMING AN STRENGTH OF THE SYSTEM. THE STRONG INSTABILITY AND GOOD SHEAR ARE MORE COMMON FOR MAY THAN AUGUST. SO THERE IS A THREAT OF DAMAGING WINDS AND LARGE HAIL WITH STORMS THAT DEVELOP. AS WITH ANY FORECAST OF CONVECTION SO MANY DAYS OUT THE MODELS WILL LIKELY CHANGE...SO WE WILL CONTINUE TO MONITOR IT. AS FOR THE WORK WEEK (MONDAY THROUGH THURSDAY)...OVERALL...MUCH DRIER THAN THIS LAST WEEK...BUT HARD TO RULE OUT A HIT AND MISS AFTERNOON AND EVENING STORM ESPECIALLY MONDAY...BUT THE MODELS ARE STILL WAFFLING WITH TIMING AND STRENGTH OF FEATURES SO WILL LEAVE DRY OR LOW PROBABILITIES UNTIL OUR CONFIDENCE RISES MORE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1252 AM CDT FRI AUG 29 2014 VFR CONDITIONS ARE FORECAST. WIND WILL REMAIN LIGHT AND SKY COVER WILL REMAIN MID-HIGH LEVEL. DISCOUNTING FOG AND STRATUS ADVERTISED BY THE NAM NUMERICAL MODEL. WE COULD GET A THUNDERSHOWER DURING THE DAY FRIDAY ASSOCIATED WITH A PASSING TROUGH AXIS...BUT CHANCES ARE FAIRLY LOW AND TIMING IS DIFFICULT TO DETERMINE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...WESELY LONG TERM...EDDY AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
158 AM EDT FRI AUG 29 2014 .SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT IN SOUTHERN VIRGINIA WILL STALL OUT NEAR OR JUST SOUTH OF THE NORTH CAROLINA BORDER TODAY. THE FRONT WILL GRADUALLY DISSIPATE OVER THE WEEKEND AS A LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 PM THURSDAY... THE BACKDOOR SEGMENT OF THE COLD FRONT ORIENTED FROM NW TO SE ACROSS SOUTH-CENTRAL VA HAS MAINTAINED A BAND OF WEAK CONVECTION CENTERED NEAR FARMVILLE...VA FOR THE PAST SEVERAL HOURS. A PRECEDING...PRE- FRONTAL TROUGH DRAPED ACROSS CENTRAL NC HAS BEEN DEVOID OF ANY SUCH ACTIVITY...HOWEVER...DESPITE A RIBBON OF LOW-MID LEVEL MOISTURE CONVERGENCE AND WEAK AND SEEMINGLY UNINHIBITED ML INSTABILITY PER 00Z GSO AND MHX RAOB DATA. RECENT RUNS OF THE HRRR CONTINUE TO SUGGEST THE CONVECTION OVER SOUTH-CENTRAL VA WILL DRIFT SOUTH ACROSS THE NORTHEAST PIEDMONT AND NORTHERN COASTAL PLAIN...AND SUCH A SCENARIO SEEMS PLAUSIBLE GIVEN THE ENVIRONMENT DESCRIBED ABOVE. WILL CONSEQUENTLY MAINTAIN A SLIGHT-SMALL CHANCE OF A SHOWER OR STORM THERE OVERNIGHT. THE OTHER...AND HIGHER PROBABILITY...CONCERNS INCLUDE THE DEVELOPMENT OF AREAS OF FOG...OWING TO SAID LOW LEVEL MOISTURE POOLING ALONG THE PRE-FRONTAL TROUGH AXIS...AND LOW CLOUDS IN POST-FRONTAL NE LOW LEVEL FLOW ONCE THE FRONT SETTLES SOUTH INTO THE SANDHILLS AND SOUTHERN PIEDMONT BY EARLY FRI. IN FACT...A LOW OVERCAST IS APT TO DEVELOP GENERALLY ALONG AND NORTH OF HWY 64 VERY LATE TONIGHT THROUGH EARLY FRI. IF THE LOW CLOUDS INDEED MATERIALIZE...THEIR DISPERSION THROUGHOUT THE DAY FRI WOULD BE SLOW OWING A TRAPPING FRONTAL INVERSION BEHIND THE SOUTHWARD-SETTLING FRONT...WHICH COULD IMPACT HIGH TEMPS FRI. LOWS TONIGHT IN THE MID 60S TO LOW 70S. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 200 PM THURSDAY... FRIDAY AND FRIDAY NIGHT: THE UPPER LEVEL RIDGE WILL AMPLIFY OVER THE MID-ATLANTIC ON FRIDAY. AT THE SURFACE...THE FRONT WILL BE STALLED IN THE VICINITY OF THE NC/VA BORDER DURING THE DAY BEFORE SLOWLY RETREATING TO THE NE OVERNIGHT. MUCH OF THE WEATHER WILL DEPEND ON THE LOCATION OF THE FRONTAL BOUNDARY THROUGHOUT THE DAY. THE LOWER TEMPS WILL BE ALONG AND NORTH OF THE FRONT...WITH HIGHER HIGHS ACROSS THE SOUTH. ANY CONVECTION THAT DEVELOPS WILL BE MAINLY ALONG AND SOUTH OF THE FRONT...BUT EXPECT COVERAGE TO BE ISOLATED AT BEST AND CONFIDENCE THAT IT WILL DEVELOP IS NOT TERRIBLY HIGH AT THIS TIME. CONTINUED MID LEVEL MOISTURE ADVECTION SHOULD RESULT IN CLOUDY CONDITIONS THROUGH A GOOD PART OF THE DAY. NORTHEASTERLY WINDS ALONG AND NORTH OF THE FRONT AND SOUTHWESTERLY SOUTH OF IT DURING THE DAY/EVENING SHOULD BECOME GENERALLY SOUTHEASTERLY ACROSS THE AREA OVERNIGHT. HIGHS EXPECTED TO RANGE FROM THE MID 80S NORTH TO LOW 90S SOUTH. LOWS IN THE UPPER 80S TO AROUND 70 DEGREES. -KC SATURDAY AND SATURDAY NIGHT: NORTH CAROLINA WILL STILL BE UNDER THE INFLUENCE OF A STRONG UPPER LEVEL RIDGE AND AN EXITING SURFACE HIGH PRESSURE TO THE NORTHEAST. THIS WILL KEEP WEATHER DRY AND SETTLED ON SATURDAY AND SATURDAY AFTERNOON. CONDITIONS WILL BE STABLE AND A SLIGHT DECREASE IN MOISTURE MAY HELP HIGH TEMPERATURES TO REACH THE LOWER 90S IN MOST LOCATIONS WITH UPPER 80S ACROSS THE NORTHERN COUNTIES. WINDS WILL BE OUT OF THE SOUTH AT AROUND 5 KTS GUSTING TO 10 KTS. THE HIGH WILL CONTINUE TO MOVE OFFSHORE SATURDAY NIGHT...ALLOWING MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO TO INCREASE AS A DISSIPATING LOW PRESSURE SYSTEM MOVES EASTWARD OUT OF THE NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THIS WILL SET THE STAGE FOR A MORE UNSETTLED PATTERN BEGINNING ON SUNDAY. LOWS SATURDAY NIGHT UPPER 60S TO LOWER 70S. -ELLIS && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 245 PM THURSDAY... SUNDAY THROUGH TUESDAY NIGHT: A MORE UNSETTLED PERIOD OF WEATHER WILL BEGIN ON SUNDAY WITH HIGH PRESSURE OFFSHORE SETTING UP A RETURN FLOW REGIME OVER CENTRAL NC THAT WILL TRANSPORT MOISTURE INTO THE AREA FROM THE GULF OF MEXICO AND SOUTHWESTERN ATLANTIC. AS PW VALUES CREEP UP OVER TWO INCHES THE CHANCES FOR CONVECTION WILL INCREASE...MAINLY DRIVEN BY INSTABILITY DURING THE DIURNALLY FAVORABLE TIMES AS SHEAR WILL REMAIN VERY WEAK. HIGH TEMPERATURES ARE EXPECTED TO RISE INTO THE LOWER 90S EACH DAY WITH LOWS IN THE LOWER 70S. WEDNESDAY AND THURSDAY: A MORE DEFINED FRONTAL SYSTEM WILL MOVE IN ON WEDNESDAY AS LOW PRESSURE MOVES THROUGH SOUTHERN QUEBEC AND A STRONG SURFACE HIGH BUILDS IN OVER THE GREAT LAKES AND EXTENDING DOWN INTO THE OHIO VALLEY. WITH THE LOW RAPIDLY MOVING OFF TO THE NORTHEAST...FORCING ALONG THE ATTENDANT COLD FRONT WILL REMAIN WEAK AS SHOWN BY SMALL STRAIGHT HODOGRAPHS THROUGH THE LOWEST 6KM ON MODEL FORECAST SOUNDINGS. TIMING OF THE FRONT AND ASSOCIATED PRECIPIATION IS IN QUESTION AT THIS TIME WITH MODELS HINTING AT A LATE WEDNESDAY/EARLY THURSDAY ARRIVAL AND THEN STALLING OUT SOMEWHERE OVER THE AREA FOR LATE WEEK. MOST CONVECTIVE ACTIVITY WILL REMAIN DIURNAL WITH THE SLIGHT CHANCES OVERNIGHT. TEMPERATURES SLIGHTLY COOLER WITH MORE ANTICIPATED CLOUD COVER AND SLIGHT AIRMASS CHANGE. UPPER 80S TO NEAR 90 FOR HIGHS WITH LOWS UPPER 60S TO NEAR 70 DEGREES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 150 AM FRIDAY... 24-HR TAF PERIOD: BELOW AVERAGE CONFIDENCE IN THE FORECAST THROUGH TONIGHT. A BACK DOOR COLD FRONT ORIENTED WEST-EAST ACROSS SOUTHERN VA AT 06Z WILL MOVE SLOWLY SOUTH TOWARD THE NC BORDER TODAY... EVENTUALLY STALLING OUT NEAR OR JUST SOUTH OF THE BORDER ACROSS THE NORTHERN PIEDMONT. MODEL GUIDANCE CONTINUES TO VARY CONSIDERABLY WITH REGARD TO CEILINGS AND PRECIP CHANCES TODAY INTO TONIGHT. THE 00Z NAM INDICATES A HYBRID COLD AIR DAMMING WEDGE WITH MVFR/IFR CEILINGS AND ELEVATED SHOWER ACTIVITY DEVELOPING BETWEEN 12-18Z AT ALL OF THE NORTHERN TERMINALS (INT/GSO/RDU/RWI)...WHILE THE GFS INDICATES VFR CONDITIONS PREVAILING OUTSIDE OF MVFR CONDITIONS ASSOC/W ISOLD SFC-BASED CONVECTION. WITH LITTLE INDICATION ONE WAY OR THE OTHER...WILL SPLIT THE DIFFERENCE AND INTRODUCE A TEMPO GROUP FOR BKN015 BETWEEN 12-16Z EVERYWHERE EXCEPT THE FAY TERMINAL. LOOKING AHEAD: EXPECT A NEAR CLIMATOLOGICAL PATTERN THROUGH EARLY NEXT WEEK WITH A SLIGHT CHANCE OF AFTERNOON/EVENING CONVECTION AND A POTENTIAL FOR EARLY MORNING FOG/STRATUS. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...MWS SHORT TERM...KC/ELLIS LONG TERM...ELLIS AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
434 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY... WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS... EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MIDAFTERNOON... SO AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500 J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK CONTAINS A /SEE TEXT/ OVER OUR AREA. TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE LATE EVENING OVER NORTHCENTRAL MN LAKES. SATURDAY SHOULD BE DRY AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY... OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3 OUTLOOKS. MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION. HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 415 AM CDT FRI AUG 29 2014 EXPECT -SHRA TO CONTINUE ACROSS THE FAR SRN VALLEY AND INTO LAKES COUNTY. OTHERWISE MOST AREAS WILL SEE MVFR/IFR CIGS AND PATCHY FOG THROUGH TEH EARLY MORNING. CIGS WILL BECOME MAINLY VFR BY NOON FRIDAY AHEAD OF A SFC COLD FRONT FORECAST TO CROSS THE AREA. SCT SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT AND WILL INCLUDE SOME MENTION AND TIMING IN 12Z TAFS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...GUST LONG TERM...GUST/JR AVIATION...GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
337 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT FRI AUG 29 2014 THE 07 UTC SURFACE OBSERVATIONS PLACE THE COLD FRONT IN FAR NORTHWEST NORTH DAKOTA. THE COLD FRONT HAS BEEN SLOW MOVING EARLY THIS MORNING AND IS EXPECTED TO CONTINUE A SLOW PROGRESSION SOUTHEAST ACROSS THE AREA. LATEST RUNS OF THE HRRR AND WRF HAVE HAD A DIFFICULT TIME FORECASTING PRECIPITATION AHEAD AND BEHIND THE FRONT. AT THIS TIME EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH THE MORNING AND AFTERNOON AS THE FRONT PASSES. FOR NOW LEFT THE POSSIBILITY OF THUNDER IN THE FORECAST UP TO 12 UTC THIS MORNING THEN REMOVED THUNDER CHANCES FROM 12 TO 18 UTC. AFTER 18 UTC THERE SHOULD BE ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED THUNDER ALONG THE FRONT. LATEST 07 UTC SURFACE OBSERVATIONS SHOW WIND HAS WENT MOSTLY CALM OVER THE SOUTHEASTERN PORTION OF NORTH DAKOTA. WITH AMPLE LOW LEVEL MOISTURE FOG HAS STARTED TO DEVELOP ACROSS THE SOUTH CENTRAL AND SOUTHEAST. AT THIS TIME DO NOT BELIEVE ANY HEADLINE FOR FOG IS NEEDED AND HAVE OPTED WITH A SPECIAL WEATHER STATEMENT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 335 AM CDT FRI AUG 29 2014 BEGINNING SATURDAY A WELL DEFINED SHORTWAVE TROUGH WILL BE MOVING FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS. A SURFACE TROUGH AND FRONTAL BOUNDARY WILL MOVE THROUGH WESTERN NORTH DAKOTA BY SATURDAY NIGHT. MODELS HAVE BEEN CONSISTENT IN GENERATING A LINE OF CONVECTION WITH THE FRONT. MODEL CAPES ARE INITIALLY AROUND 2000 SATURDAY AFTERNOON WEST. AS THE SHORTWAVE AND SURFACE TROUGH MOVE EAST AN H850 SOUTHERLY INFLOW OF 50 KTS WILL SUPPLY ABUNDANT MOISTURE. THE PROGRESSIVE LINE OF STORMS LIKELY WILL PRODUCE AN INCH OF QPF ACROSS CENTRAL NORTH DAKOTA....WITH LOCALLY HIGHER AMOUNTS. CAPE AND SHEAR SUGGEST A PERIOD OF SEVERE STORMS (LARGE HAIL/WINDS) ARE POSSIBLE WESTERN NORTH DAKOTA LATE SATURDAY AFTERNOON/EVENING. KEPT THE HIGH POPS ACROSS WEST AND CENTRAL SECTION SATURDAY EVENING AND TRAILED THEM DOWN AFTER MIDNIGHT. FOLLOWING THIS A PERIOD (SUNDAY THROUGH TUESDAY) OF A RELATIVELY COOL AND WEAKLY CYCLONIC FLOW ALOFT. THIS SHOULD SUPPORT WIDELY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. WEDNESDAY WILL BECOME A TRANSITION DAY WITH DRY WEATHER AS THE NEXT SHORTWAVE IS MOVING INTO THE NORTHWEST US WITH A DOWNSTREAM RIDGE OVER THE NORTHERN PLAINS. THURSDAY WILL PICK UP A CHANCE FOR THUNDERSTORMS AGAIN WITH THIS NEXT SHORTWAVE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 335 AM CDT FRI AUG 29 2014 LIFR CONDITIONS AT KJMS AND PERIODICALLY AT KBIS THIS MORNING DUE TO LOW CLOUDS AND FOG. AN ISOLATED THUNDERSTORM WILL BE POSSIBLE AT SITE KISN EARLY THIS MORNING. THE MAIN THREAT WILL BE THE GUSTY WINDS AS ANY PRECIPITATION SHOULD BE BRIEF. ELSEWHERE VFR CONDITIONS ARE ANTICIPATED THROUGH THE 06 TAF PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MM LONG TERM...WAA AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1144 PM CDT THU AUG 28 2014 .UPDATE... ISSUED AT 1144 PM CDT THU AUG 28 2014 NO CHANGES PLANNED FOR THIS UPDATE. UPDATE ISSUED AT 934 PM CDT THU AUG 28 2014 NO CHANGES PLANNED FOR THIS UPDATE. UPDATE ISSUED AT 648 PM CDT THU AUG 28 2014 SATELLITE AND OBSERVATIONS SHOW CLOUD COVER PERSISTING OVER THE AREA. HRRR AND RUC SHOWING A DELAY IN MOVING CLOUDS OUT OF THE DVL BASIN SO ADJUSTED SKY GRIDS FOR THIS UPDATE. OTHERWISE...REST OF FORECAST LOOKS GOOD. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 250 PM CDT THU AUG 28 2014 THE MAIN CHALLENGE WILL BE PRECIP CHANCES. MODELS ARE IN GOOD OVERALL AGREEMENT WITH NO REAL PREFERENCE TODAY. FOR THIS EVENING AND OVERNIGHT...EXPECT SOME SHOWERS AND PERHAPS A RUMBLE OF THUNDER THIS EVENING IN ALL BUT THE FAR NW. THE BEST CHANCE FOR SHOWERS OVERNIGHT WILL BE ALONG AND SOUTHEAST OF A WAHPETON TO BAUDETTE LINE...WHERE DEEPER MOISTURE AND THE BEST LIFT WILL BE. HAVE LINGERED POPS A BIT LONGER IN THE EAST THROUGH MOST OF THE OVERNIGHT. ON FRIDAY...A COOL FRONT WILL MOVE FROM NW TO SE. THERE SHOULD BE A BAND OF SHOWERS AND STORMS ALONG AND BEHIND THE COLD FRONT...WITH THE BEST CHANCE FOR MEASURABLE PRECIP IN THE NORTH DURING THE MORNING...THEN IN THE SOUTH AND EAST DURING THE AFTERNOON. THERE WILL BE MLCAPES OVER 1500 J/KG...SO A FEW STRONGER STORMS ARE POSSIBLE DURING THE AFTERNOON. DEEP LAYERED SHEAR WILL BE WEAK THOUGH...LESS THAN 20 KT...SO EXPECT PULSE TYPE STORMS WITH PERHAPS SOME SMALL HAIL AND/OR BRIEF WIND GUSTS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 250 PM CDT THU AUG 28 2014 FOR SATURDAY...IT SHOULD BE A DRY AND SEASONABLE DAY WITH HIGH PRESSURE IN CONTROL. FOR SAT NIGHT...A FAIRLY CLASSIC ELEVATED CONVECTIVE EVENT IS POSSIBLE. A LLJ WILL INCREASE TO AROUND 50 KT INTO CENTRAL ND AFTER 00Z SUN...ALONG WITH SHOWALTERS FALLING TO AROUND -4C SAT NIGHT WITH 40KT OF EFFECTIVE SHEAR. THIS SHOULD LEAD TO AN ELEVATED MCS MOVING FROM SW TO NE SAT NIGHT INTO SUNDAY MORNING. A FEW STORMS COULD BE STRONG TO SEVERE WITH LARGE HAIL THE MAIN THREAT. ON SUNDAY...THE SEVERE POTENTIAL WILL INCREASE DURING THE AFTERNOON IN THE EAST AND SOUTH. THERE WILL BE AMPLE DEEP LAYERED SHEAR AND INSTABILITY...AND THE POTENTIAL FOR FAIRLY WIDESPREAD SHOWERS AND STORMS. SPC HAS OUTLOOKED THE EASTERN AREAS IN A DAY4 OUTLOOK...SO WE WILL HAVE TO MONITOR SUNDAY AFTERNOON FOR SEVERE POTENTIAL DEPENDING ON THE EXACT LOCATION OF THE FRONT AND WHICH AREAS RECEIVE INSOLATION DURING THE AFTERNOON. FOR SUN NIGHT THROUGH THU...MODELS IN SIMILAR AGREEMENT EARLY IN THE PERIOD WITH ZONAL UPPER AIR PATTERN AND A FRONT EXITING THE REGION...WITH MOST ASSOCIATED CONVECTION EAST OF THE AREA BY SUN NIGHT. MAIN DIFFERENCE IS DEPTH OF UPPER LOW OVER WRN ONTARIO...WITH GFS SHOWING A DEEPER LOW THAN ECMWF. CONSALL YIELDING CHANCE POPS BACK INTO THE VALLEY WITH THIS EXITING SYSTEM. WITH 12Z MODEL RUNS FASTER THAN THIS AND NO COORD ISSUES TO MY WEST...WILL LOWER POPS IN THE VALLEY TO 20S OR DRY. MON THROUGH WED THEN GENERALLY DRY...WITH A FEW MINOR SHORT WAVES YIELDING SOME LOW END POPS...AND SEASONAL TEMPS BEFORE NEXT SYSTEM WORKS ITS WAY ACROSS SRN CANADA AND BRINGS A CHANCE FOR TSTMS ACROSS THE NORTHERN PORTION OF THE CWA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1144 PM CDT THU AUG 28 2014 EXPECT -SHRA TO CONTINUE ACROSS THE SRN VALLEY AND INTO LAKES COUNTY...WITH SPOTTY SHOWERS FARTHER NORTH. CIGS CONTINUE TO BE A CHALLENGE BUT EXPECT CIGS TO LOWER INTO THE MVFR/IFR CATEGORY OVER THE NEXT FEW HOURS...WITH AREAS OF PATCHY FOG. CIGS WILL BECOME MAINLY VFR BY NOON FRIDAY AHEAD OF A SFC TROF FORECAST TO CROSS THE AREA. SOME SHOWERS MAY POP UP AHEAD OF THE TROF BUT NOT ENOUGH TO MENTION IN TAFS ATTM. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...HOPKINS SHORT TERM...DK LONG TERM...DK/SPEICHER AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1116 PM CDT THU AUG 28 2014 .UPDATE...ADDED AVIATION SECTION FOR 06Z TAF`S. && .AVIATION...BNA/CKV/CSV...EXCELLENT RADIATIONAL COOLING IS UNDERWAY THIS EVENING WITH FOG ALREADY DEVELOPING AT CSV AND EXPECTED TO FORM AT CKV LATER TONIGHT. LOOK FOR FOG TO SCATTER OUT SHORTLY AFTER 12Z FRIDAY MORNING, WITH VFR WX THE REST OF THE WAY. && .PREV DISCUSSION... /ISSUED 934 PM CDT THU AUG 28 2014/ UPDATE...FOR EVENING DISCUSSION. DISCUSSION... CONVECTION HAS COME TO AN END FOR NOW. A COUPLE OF OUTFLOW BOUNDARIES ARE STILL FLOATING AROUND MIDDLE TENNESSEE WITH PLENTY OF INSTABILITY TO BE TAPPED INTO. WILL KEEP A SLIGHT CHANCE POP FOR AREAS BASICALLY ALONG AND NORTH OF INTERSTATE 40 UNTIL MIDNIGHT OR SO TO ACCOUNT FOR THIS. SOME PATCHY LATE-NIGHT/EARLY MORNING FOG WILL BE LIKELY FOR THOSE WHO SAW RAINFALL THIS EVENING. THE FRONTAL BOUNDARY THAT HAS BEEN RESPONSIBLE FOR THIS EVENING`S CONVECTION WILL PULL OFF TO THE NORTH LATER TONIGHT AND THIS SHOULD TAKE POPS OUT OF THE FORECAST FOR FRIDAY. UPDATES ON THE WAY. UNGER AVIATION...00Z TAF DISCUSSION. BNA/CKV/CSV...ISOLATED CELLS CONTINUE ACROSS MAINLY NORTHERN MIDDLE TENNESSEE LATE THIS AFTERNOON. HRRR SHOWS EXISTING ACTIVITY DISSIPATING DURING THE EVENING AS WE LOSE DAYTIME HEATING. SURFACE RIDGE HAS SLIPPED TO OUR EAST WITH WEAK RETURN FLOW NOW UNDERWAY. EXPECT FULL RADIATIONAL COOLING OVERNIGHT, WITH LIGHT FOG POSSIBLE AT CKV AND CSV. VERY LITTLE CHANCE OF CONVECTION ON FRIDAY, SO WE SHOULD BE VFR THE NEXT 24 HRS OUTSIDE OF EARLY MORNING FOG. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ROSE
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
424 AM CDT FRI AUG 29 2014 .SHORT TERM (TODAY THROUGH SATURDAY)...WEAK SURFACE LOW AND MID LEVEL WEAKNESS CURRENTLY LOCATED NEAR THE COAST OF DEEP SOUTH TEXAS WITH ABUNDANT MOISTURE ASSOCIATED WITH IT. WHAT HAPPENS TODAY WILL HAVE EVERYTHING TO DO WITH THE MOVEMENT OF THIS LOW THROUGH THE DAY. A NEARLY STATIONARY POSITION WAS THE GENERAL CONSENSUS EARLY TONIGHT...BUT LATEST MESO MODELS ARE STARTING TO SUGGEST THE LOW PULLING SOUTH AND EAST THIS MORNING. THIS WOULD LEAD TO SLIGHTLY LOWER MOISTURE...AND LESS LIFT OVER FORECAST AREA...HOLDING THE MUCH NEEDED RAIN MOSTLY OFFSHORE DURING THE DAY. WHILE THE 06Z HRRR HAS ALSO GONE THIS DIRECTION...WILL STILL HOLD OUT HOPE THAT ENOUGH MOISTURE IS IN PLACE TO VERIFY CHANCE TO LIKELY POPS ACROSS EASTERN AREAS. THERE WAS SOME CONCERN FOR HEAVY RAINFALL...BUT THINK THAT SHOULD REMAIN SOUTH OF FORECAST AREA. HAVE LOWER POPS WEST...BUT THINK SOME AFTERNOON CONVECTION SHOULD MAKE ITS WAY WEST. HAVE GONE A BIT COOLER WITH MAX TEMPS...ESPECIALLY EAST WHERE DEEPER MOISTURE/CLOUD COVER IS EXPECTED. STILL HAVE EVERYONE IN THE 90S...BUT LOWER 90S...ESPECIALLY SOUTHEAST ZONES. TOMORROW NIGHT LOOKS QUITE SIMILAR TO TONIGHT...EXCEPT FEEL BETTER CHANCE FOR POPS WILL BE A BIT FURTHER EAST AS UPPER ENERGY BECOMES ELONGATED JUST OFFSHORE THE MIDDLE TEXAS COAST. HAVE SLIGHTLY LOWER POPS THAN TODAY...AND TEMPS BACK TOWARD NORMAL FOR SATURDAY. A LIGHT TO MODERATE SOUTHEAST WIND CAN BE EXPECTED BOTH FRIDAY AND SATURDAY. && .LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...UPPER LEVEL WEAKNESS WILL RESIDE OVER SOUTH TEXAS TO BEGIN THE LONG TERM. MOISTURE WILL REMAIN SUFFICIENT ESPECIALLY OVER THE COASTAL PLAINS SATURDAY NIGHT AND SUNDAY...RESULTING IN ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. BY MONDAY...FLATTENED UPPER LEVEL RIDGE WILL SETTLE OVER SOUTH TEXAS ALONG WITH SLIGHTLY DRIER AIR. THIS SHOULD KEEP CHANCES FOR SHOWERS AND STORMS TOO LOW TO MENTION IN THE FORECAST. A TROPICAL WAVE CURRENTLY LOCATED IN THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE WESTWARD THROUGH THE WEEKEND. BY EARLY NEXT WEEK... THIS SYSTEM WILL EMERGE INTO THE BAY OF CAMPECHE AND SOUTHERN GULF OF MEXICO. WHILE DEEPEST MOISTURE SHOULD REMAIN TO THE SOUTH OF THE REGION...PW VALUES WILL RETURN TO AROUND 2 INCHES OVER THE COASTAL LOCATIONS/MARINE ZONES BY WEDNESDAY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN BY TUESDAY...AND CONTINUING THROUGH THURSDAY. WARMEST DAYS OF THE EXTENDED WILL BE SUNDAY AND MONDAY...WITH TEMPS BEING SET BACK A FEW DEGREES BY MID WEEK AS THE DEEPER MOISTURE RETURNS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 90 78 92 78 96 / 60 40 40 20 30 VICTORIA 93 76 93 76 98 / 50 30 40 20 30 LAREDO 98 79 98 79 103 / 30 30 20 20 10 ALICE 91 77 93 76 99 / 50 30 30 20 20 ROCKPORT 88 79 90 79 93 / 60 40 40 20 30 COTULLA 97 76 97 76 101 / 30 20 20 20 10 KINGSVILLE 91 78 92 78 98 / 60 40 30 20 20 NAVY CORPUS 87 80 89 80 92 / 60 50 40 20 30 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...RIP CURRENT RISK THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. GM...NONE. && $$ PZ/83...SHORT TERM TB/78...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1201 AM CDT FRI AUG 29 2014 .AVIATION... /06Z TAFS/ Numerous showers and thunderstorms are moving east across the northern half of West Central Texas. Initially Carrying a TSRA mention at KABI, with VCSH at KSJT. The showers and storms will move east and gradually dissipate overnight, with considerable high cloudiness remaining over the northern half of the area. Patchy low cloud development is possible early Friday morning in some of our southern/southeastern counties, and including a scattered layer at our southern TAF sites. Scattered showers and thunderstorms could develop by Friday afternoon, but with uncertainty on coverage and placement, holding off with VCTS groups at this time. Wind field has been disrupted by passage of an outflow boundary at KABI and near TAF issuance time at KSJT. Winds overnight will veer from southeast to south. On Friday, south winds in the morning will back to the southeast during the afternoon. 19 && .PREV DISCUSSION... /ISSUED 646 PM CDT THU AUG 28 2014/ AVIATION... /00Z TAFS/ Scattered showers and thunderstorms over west and northwest Texas are slowly moving east this evening. A few of these may enter our western and northwestern counties, through early tonight. Have more uncertainty on whether any of our TAF sites will be affected. KABI and KSJT may potentially be affected, and will monitor radar trends for possible update and inclusion of TSRA. Otherwise, high cloud cover from the aforementioned convection will overspread West Central Texas this evening and early tonight. On Friday, scattered showers and thunderstorms will be possible, mainly during the afternoon and across the Big Country area north of Interstate 20. Patchy low cloud development is possible toward morning across some of our southern counties, and have a scattered layer included at KSOA and KJCT. Southeast winds will veer to the south overnight and continue on Friday morning. PREV DISCUSSION... /ISSUED 340 PM CDT THU AUG 28 2014/ SHORT TERM... (Tonight and Friday) Rain chances for the next 24 hours continue to look more promising. The latest WSR-88D data indicate showers and thunderstorms are developing across the Big Country. The RUC indicates this activity will continue to develop and spread into mainly our northwestern counties during the next 6 hours. Overnight tonight, the NAM fragments the QPF into small areas across mainly our northwestern counties. Given the uncertainty across our southeastern counties, slight chance PoPs still look good there. Elsewhere, and especially north of our Interstate 20 corridor, chance PoPs look best. As the upper trough axis pushes farther east tomorrow, the better rain chances will expand south and include more of our southern counties. The main thunderstorm threats for the next 24 hours are deadly lightning and flash flooding from locally heavy rainfall. Huber LONG TERM... (Friday night to Thursday) While the upper trough will be east of the region Friday night and Saturday, a weakly capped atmosphere will remain. Therefore, isolated, mainly afternoon and evening showers and thunderstorms will continue to be possible. The upper ridge strengthens Sunday, however, with hot and dry conditions expected through next week. Highs are expected mainly in the mid 90s. 04 && .PRELIMINARY POINT TEMPS/POPS... Abilene 72 93 72 96 73 / 50 30 20 20 10 San Angelo 73 94 72 96 74 / 30 30 20 20 10 Junction 73 93 73 95 74 / 20 20 20 20 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1123 PM CDT THU AUG 28 2014 .AVIATION...TRANQUIL CONDITIONS ARE IN EFFECT ACROSS ALL OF SOUTH- CENTRAL TEXAS. MINOR CHANGES WERE MADE TO THE EXISTING TAFS WITH A COUPLE OF PERIODS APPENDED TO THE END OF MOST OF THE TAFS. VFR WILL PREVAIL THROUGH THE NEXT HANDFUL OF HOURS UNTIL THE FORMATION OF A DECK OF STRATUS AROUND 2K FEET INITIATES MVFR AS SURFACE WINDS BECOME LIGHT. TOMORROW...WINDS WILL INCREASE TO MODERATE LEVELS AS DAYTIME HEATING RESUMES VFR FOR THE AFTERNOON/EVENING HOURS. WILL LET THE INCOMING SHIFT DETERMINE IF ANY CONVECTIVE MARKERS (VCSH/TSRA) NEED TO BE INSERTED INTO ANY OF THE TAFS AROUND SUNRISE FRIDAY MORNING...A REAL DEBATE SINCE THE OFFICIAL FORECAST STILL SHOWS SCATTERED SHOWERS/THUNDERSTORMS WHILE MAV/MET GUIDANCE LEANS MORE TOWARDS ISOLATED. MVFR SHOULD SET UP TOMORROW NIGHT WITH SURFACE WINDS BECOMING NEARLY CALM AND CLOUD DECKS LOWERING. && .PREV DISCUSSION... /ISSUED 1109 PM CDT THU AUG 28 2014/ UPDATE...UPDATE TO INCLUDE 20 POPS FOR OVERNIGHT ACROSS THE NORTHERN HILL COUNTRY AND PORTIONS OF EDWARDS PLATEAU. RADAR TRENDS INDICATE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE LOW ROLLING PLAINS OF NORTHWEST TEXAS HAVE PROGRESSED SLIGHTLY FARTHER SOUTH AND EAST THAN SEVERAL MODELS WERE INDICATING. WHILE EVENTUAL WEAKENING TREND IS EXPECTED...A FEW SHOWERS MAY CLIP THE NORTHERN ROW OF COUNTIES BEFORE THIS HAPPENS...INDICATED NOW BY HRRR AND RUC. PREV DISCUSSION... /ISSUED 620 PM CDT THU AUG 28 2014/ AVIATION...TAFS INHERITED FROM THE PREVIOUS SHIFT LOOKED GREAT SO NO MAJOR ADJUSTMENTS WERE MADE. THE ONLY SLIGHT CHANGES THAT WERE MADE WERE TO INITIAL CONDITIONS AND TO APPEND A FM291900 PERIOD ON THE END OF 3 OUT OF 4 OF THE TAFS. RADAR STILL SHOWING ISOLATED SHOWERS IN THE VICINITY OF AUS...SO THE VCSH WAS RETAINED FOR THAT TAF...DESPITE THE RECENT TREND OF RAPIDLY DIMINISHING CONVECTION ACROSS THE VAST MAJORITY OF SOUTH-CENTRAL TEXAS. VFR WILL REIGN THROUGH THE NEXT FEW HOURS UNTIL THE DEVELOPMENT OF A LOWERED STRATUS DECK AROUND 2K FEET INITIATES MVFR CONDITIONS FOR 75 PERCENT OF THE TAF SITES. MVFR WILL CONTINUE THROUGH THE FRIDAY MORNING HOURS UNTIL DAYTIME HEATING AND INCREASING SURFACE WINDS RETURNS VFR TO THE AREA WITH RISING CLOUD DECKS LIKELY FOR THE AFTERNOON AND EVENING HOURS. CURRENT FORECAST FOR FRIDAY INDICATES SCATTERED (30 PERCENT) CONVECTION FOR THE DAY...HOWEVER MET/MAV MODEL GUIDANCE ONLY SHOWS ISOLATED. CONSIDERED INCLUDING A VCSH IN THE FM291900 PERIOD BASED ON THE CURRENT FORECAST...BUT WILL ALLOW THE OVERNIGHT SHIFT TO ADDRESS THIS ISSUE USING MODEL GUIDANCE AND FORECAST REASONING CLOSER TO THE FRIDAY TIME FRAME. PREV DISCUSSION... /ISSUED 320 PM CDT THU AUG 28 2014/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)... ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE CONTINUING EAST OF INTERSTATE 35 THIS AFTERNOON. THIS ACTIVITY IS IN RESPONSE TO INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE BROAD LOW PRESSURE SYSTEM IN THE WESTERN GULF OF MEXICO. AS THE ACTIVITY PUSHES WEST...NEAR THE I-35 CORRIDOR...THE SHOWERS AND STORMS ARE DISSIPATING DUE TO LIMITED MOISTURE. DEW POINTS IN THESE LOCATIONS ARE IN THE MIDDLE 60S VERSUS THE LOWER 70S IN THE SOUTHEASTERN ZONES. THESE SHOWERS AND STORMS ARE PRIMARILY DIURNALLY DRIVEN AND SHOULD WEAKEN AND DISSIPATE AROUND SUNSET. LOWS TONIGHT ARE EXPECTED TO BE IN THE LOWER TO MIDDLE 70S ACROSS MUCH OF THE AREA. THERE COULD BE SOME LEFT OVER SHOWERS AND STORMS IN THE EASTERN ZONES AS WELL AS WEAKENING CONVECTION NEAR VAL VERDE COUNTY THIS EVENING FROM STORMS MOVING EAST IN WEST TEXAS. SOME OF THE HIGH-RES GUIDANCE IS HINTING AT OVERNIGHT STORMS REGENERATING ACROSS THE EASTERN ZONES. THIS CAN BE SOMEWHAT EXPECTED FROM TROPICAL SYSTEMS...THE MAIN QUESTIONS ARE IF AND WHERE ANY CONVECTION WILL DEVELOP NEAR DAYBREAK. LOW POPS ACROSS THE EASTERN ZONES SHOULD COVER THIS. FRIDAY SHOULD BE SOMEWHAT SIMILAR TO TODAY. THE MAIN LIFT ASSOCIATED WITH THE UPPER TROUGH CURRENTLY IN COLORADO WILL PUSH NORTH OF THE AREA. THUS...THE MAIN LIFT WILL PASS NORTH AS WELL. THERE SHOULD BE A WEAK SHEAR AXIS TO THE SOUTH OF THE LOW AND THIS SHOULD ALLOW A SLIGHT INCREASE TO THE EXPECTED COVERAGE OF SHOWERS AND THUNDERSTORMS FOR TOMORROW. PW VALUES WILL BE GREATER THAN 2 INCHES FOR THE EASTERN ZONES AND SOME LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. LONG TERM (SATURDAY THROUGH THURSDAY)... LINGERING CONVECTION WILL REMAIN POSSIBLE SATURDAY ACROSS MUCH OF THE AREA. THE LOW PRESSURE SYSTEM CURRENTLY IN THE GULF OF MEXICO WILL BE SLOW TO MOVE AND WE WILL BE IN A FAVORABLE LOCATION OF INCREASED MOISTURE AND DIURNAL LIFT ASSOCIATED WITH DAY TIME HEATING. POPS WILL LINGER ACROSS THE EASTERN ZONES SUNDAY AND A DRY FORECAST IS EXPECTED ON MONDAY AS WEAK RIDGING RETURNS TO THE AREA. THE WEAK RIDGE SHIFTS EAST BY TUESDAY AND WILL KEEP LOW CHANCES OF RAIN IN THE FORECAST FOR THE SOUTHEASTERN ZONES IN THE EXTENDED FORECAST. 850 TEMPS NEXT WEEK REMAIN IN THE 18-22C RANGE AND TEMPERATURES SHOULD REMAIN BELOW THE 100 DEGREE MARK FOR MOST LOCATIONS. HAMPSHIRE && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 76 95 76 94 76 / 10 30 20 20 10 AUSTIN BERGSTROM INTL AIRPORT 75 97 74 94 74 / 10 30 20 20 20 NEW BRAUNFELS MUNI AIRPORT 74 96 74 96 74 / 10 30 20 20 20 BURNET MUNI AIRPORT 74 93 74 94 75 / 20 30 20 20 10 DEL RIO INTL AIRPORT 78 99 77 99 77 / 10 20 20 10 10 GEORGETOWN MUNI AIRPORT 76 94 76 94 76 / 20 30 20 20 10 HONDO MUNI AIRPORT 74 96 73 97 74 / 10 20 20 20 10 SAN MARCOS MUNI AIRPORT 75 97 75 95 75 / 10 30 20 20 20 LA GRANGE - FAYETTE REGIONAL 77 95 76 93 76 / 20 40 20 40 20 SAN ANTONIO INTL AIRPORT 78 98 77 96 77 / 10 30 20 20 10 STINSON MUNI AIRPORT 77 97 77 97 76 / 10 30 20 20 20 && .EWX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ MESOSCALE/AVIATION...TOMASELLI
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1109 PM CDT THU AUG 28 2014 .UPDATE...UPDATE TO INCLUDE 20 POPS FOR OVERNIGHT ACROSS THE NORTHERN HILL COUNTRY AND PORTIONS OF EDWARDS PLATEAU. RADAR TRENDS INDICATE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE LOW ROLLING PLAINS OF NORTHWEST TEXAS HAVE PROGRESSED SLIGHTLY FARTHER SOUTH AND EAST THAN SEVERAL MODELS WERE INDICATING. WHILE EVENTUAL WEAKENING TREND IS EXPECTED...A FEW SHOWERS MAY CLIP THE NORTHERN ROW OF COUNTIES BEFORE THIS HAPPENS...INDICATED NOW BY HRRR AND RUC. && .PREV DISCUSSION... /ISSUED 620 PM CDT THU AUG 28 2014/ AVIATION...TAFS INHERITED FROM THE PREVIOUS SHIFT LOOKED GREAT SO NO MAJOR ADJUSTMENTS WERE MADE. THE ONLY SLIGHT CHANGES THAT WERE MADE WERE TO INITIAL CONDITIONS AND TO APPEND A FM291900 PERIOD ON THE END OF 3 OUT OF 4 OF THE TAFS. RADAR STILL SHOWING ISOLATED SHOWERS IN THE VICINITY OF AUS...SO THE VCSH WAS RETAINED FOR THAT TAF...DESPITE THE RECENT TREND OF RAPIDLY DIMINISHING CONVECTION ACROSS THE VAST MAJORITY OF SOUTH-CENTRAL TEXAS. VFR WILL REIGN THROUGH THE NEXT FEW HOURS UNTIL THE DEVELOPMENT OF A LOWERED STRATUS DECK AROUND 2K FEET INITIATES MVFR CONDITIONS FOR 75 PERCENT OF THE TAF SITES. MVFR WILL CONTINUE THROUGH THE FRIDAY MORNING HOURS UNTIL DAYTIME HEATING AND INCREASING SURFACE WINDS RETURNS VFR TO THE AREA WITH RISING CLOUD DECKS LIKELY FOR THE AFTERNOON AND EVENING HOURS. CURRENT FORECAST FOR FRIDAY INDICATES SCATTERED (30 PERCENT) CONVECTION FOR THE DAY...HOWEVER MET/MAV MODEL GUIDANCE ONLY SHOWS ISOLATED. CONSIDERED INCLUDING A VCSH IN THE FM291900 PERIOD BASED ON THE CURRENT FORECAST...BUT WILL ALLOW THE OVERNIGHT SHIFT TO ADDRESS THIS ISSUE USING MODEL GUIDANCE AND FORECAST REASONING CLOSER TO THE FRIDAY TIME FRAME. PREV DISCUSSION... /ISSUED 320 PM CDT THU AUG 28 2014/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)... ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE CONTINUING EAST OF INTERSTATE 35 THIS AFTERNOON. THIS ACTIVITY IS IN RESPONSE TO INCREASING MOISTURE AND LIFT ASSOCIATED WITH THE BROAD LOW PRESSURE SYSTEM IN THE WESTERN GULF OF MEXICO. AS THE ACTIVITY PUSHES WEST...NEAR THE I-35 CORRIDOR...THE SHOWERS AND STORMS ARE DISSIPATING DUE TO LIMITED MOISTURE. DEW POINTS IN THESE LOCATIONS ARE IN THE MIDDLE 60S VERSUS THE LOWER 70S IN THE SOUTHEASTERN ZONES. THESE SHOWERS AND STORMS ARE PRIMARILY DIURNALLY DRIVEN AND SHOULD WEAKEN AND DISSIPATE AROUND SUNSET. LOWS TONIGHT ARE EXPECTED TO BE IN THE LOWER TO MIDDLE 70S ACROSS MUCH OF THE AREA. THERE COULD BE SOME LEFT OVER SHOWERS AND STORMS IN THE EASTERN ZONES AS WELL AS WEAKENING CONVECTION NEAR VAL VERDE COUNTY THIS EVENING FROM STORMS MOVING EAST IN WEST TEXAS. SOME OF THE HIGH-RES GUIDANCE IS HINTING AT OVERNIGHT STORMS REGENERATING ACROSS THE EASTERN ZONES. THIS CAN BE SOMEWHAT EXPECTED FROM TROPICAL SYSTEMS...THE MAIN QUESTIONS ARE IF AND WHERE ANY CONVECTION WILL DEVELOP NEAR DAYBREAK. LOW POPS ACROSS THE EASTERN ZONES SHOULD COVER THIS. FRIDAY SHOULD BE SOMEWHAT SIMILAR TO TODAY. THE MAIN LIFT ASSOCIATED WITH THE UPPER TROUGH CURRENTLY IN COLORADO WILL PUSH NORTH OF THE AREA. THUS...THE MAIN LIFT WILL PASS NORTH AS WELL. THERE SHOULD BE A WEAK SHEAR AXIS TO THE SOUTH OF THE LOW AND THIS SHOULD ALLOW A SLIGHT INCREASE TO THE EXPECTED COVERAGE OF SHOWERS AND THUNDERSTORMS FOR TOMORROW. PW VALUES WILL BE GREATER THAN 2 INCHES FOR THE EASTERN ZONES AND SOME LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. LONG TERM (SATURDAY THROUGH THURSDAY)... LINGERING CONVECTION WILL REMAIN POSSIBLE SATURDAY ACROSS MUCH OF THE AREA. THE LOW PRESSURE SYSTEM CURRENTLY IN THE GULF OF MEXICO WILL BE SLOW TO MOVE AND WE WILL BE IN A FAVORABLE LOCATION OF INCREASED MOISTURE AND DIURNAL LIFT ASSOCIATED WITH DAY TIME HEATING. POPS WILL LINGER ACROSS THE EASTERN ZONES SUNDAY AND A DRY FORECAST IS EXPECTED ON MONDAY AS WEAK RIDGING RETURNS TO THE AREA. THE WEAK RIDGE SHIFTS EAST BY TUESDAY AND WILL KEEP LOW CHANCES OF RAIN IN THE FORECAST FOR THE SOUTHEASTERN ZONES IN THE EXTENDED FORECAST. 850 TEMPS NEXT WEEK REMAIN IN THE 18-22C RANGE AND TEMPERATURES SHOULD REMAIN BELOW THE 100 DEGREE MARK FOR MOST LOCATIONS. HAMPSHIRE && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 96 76 95 76 94 / 20 10 30 20 20 AUSTIN BERGSTROM INTL AIRPORT 93 75 97 74 94 / 20 10 30 20 20 NEW BRAUNFELS MUNI AIRPORT 96 74 96 74 96 / 20 10 30 20 20 BURNET MUNI AIRPORT 96 74 93 74 94 / 20 20 30 20 20 DEL RIO INTL AIRPORT 100 78 99 77 99 / 10 10 20 20 10 GEORGETOWN MUNI AIRPORT 97 76 94 76 94 / 20 20 30 20 20 HONDO MUNI AIRPORT 96 74 96 73 97 / 20 10 20 20 20 SAN MARCOS MUNI AIRPORT 93 75 97 75 95 / 20 10 30 20 20 LA GRANGE - FAYETTE REGIONAL 94 77 95 76 93 / 40 20 40 20 40 SAN ANTONIO INTL AIRPORT 97 78 98 77 96 / 20 10 30 20 20 STINSON MUNI AIRPORT 96 77 97 77 97 / 20 10 30 20 20 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...99 SYNOPTIC/GRIDS...76
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
143 AM EDT FRI AUG 29 2014 .SYNOPSIS... A WEAK COLD FRONT WILL STALL ACROSS NORTH CAROLINA LATE TONIGHT... THEN HEAD BACK NORTH AGAIN FOR FRIDAY INTO SATURDAY. A STRONGER UPPER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS TO CLOSE OUT THE LABOR DAY WEEKEND. && .NEAR TERM /THROUGH TODAY/... AS OF 1100 PM EDT THURSDAY... BACKDOOR FRONT CURRENTLY HUNG UP OVER SOUTHSIDE VA AND NW NC...ALONG A UKF-MWK-MTV-LYH-FVX LINE. DEWPOINTS ALONG AND SOUTH OF THE FRONT ARE IN THE LOWER 70S. NORTH OF THE FRONT DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S. FRONT NOT EXPECTED TO MAKE MUCH PROGRESS OVERNIGHT...MAY DRIFT TO ALONG THE VA/NC BORDER OR JUST INTO NORTHERN NC. THERE HAS BEEN AN ONGOING CLUSTER OF SHRA/TSRA NEAR BUCKINGHAM AND FARMVILLE VCNTY OF THE FRONTAL BOUNDARY...RADAR ESTIMATING UPWARDS OF AN INCH OF RAIN FALLING OVER PARTS OF SOUTHERN BUCKINGHAM COUNTY DURING THE EVENING. THE HRRR MODEL SHOWS A GRADUAL DRIFT OF THIS PRECIP TOWARD I-95 CORRIDOR DURING THE OVERNIGHT WITH POTENTIAL REDEVELOPMENT OF SHRA VCNTY OF THE FRONT FROM CHARLOTTE COURT HOUSE EAST DURING THE OVERNIGHT. ASIDE FOR THE SHOWER THREAT ALONG THE FRONT...NOT MUCH GOING ON WEATHERWISE. THE NORTHERN/WESTERN CWA...FROM THE NC MTNS INTO THE NRV OF VA...AND FROM THE THE GREENBRIER VALLEY OF WV EAST ALONG THE I-64 CORRIDOR INTO CENTRAL VA WILL RESIDE NORTH OF THE FRONT OVERNIGHT. WITH DEWPOINTS IN THE 50S...TEMPERATURES SHOULD BE ABOUT 10 DEGREES COOLER THAN FOLKS SOUTH OF THE FRONTAL BOUNDARY WHERE READINGS WILL BE CLOSER TO 70. OVERNIGHT...SOME OF THE MODELS...ESP THE NAM...INDICATE INCREASING LOW LEVEL CLOUD COVER PER DEVELOPMENT OF EASTERLY LOW LEVEL WINDS VCNTY OF THE FRONT...THE RESULTANT UPSLOPE FLOW INTO THE BLUE RIDGE RESULTING IN CLOUD DEVELOPMENT LATE TONIGHT. ATTM WILL CONTINUE TO ADVERTISE SOME STRATUS IN THE MORNING...BUT PREFER TO KEEP OVERALL SKY CONDITIONS TONED DOWN FROM THE NAM BUT THINK AREAS OVER THE FOOTHILLS AND PIEDMONT COULD BE MOSTLY CLOUDY IN THE MORNING. PATCHY FOG WILL FORM IN THE MOUNTAIN VALLEYS LATE TONIGHT WHERE SKIES SHOULD STAY MOSTLY CLEAR...PARTLY CLOUDY AT WORST. LOWS TONIGHT WILL BE A LITTLE COOLER IN THE NORTH PER DRIER AIR WITH READINGS IN THE MID TO UPPER 50S...WHILE TEMPERATURES WILL BE CLOSER TO THE 65-70 DEGREE RANG IN THE SOUTH. FRIDAY...FRONT STARTS WORKING BACK NORTH ACROSS US. MODELS ARE AGREEMENT THAT LIFT AND MOISTURE WILL BE LIMITED OVER US BUT CANNOT RULE OUT ISOLATED SHRA/TSRA IN THE REGION. BEST LIFT WILL BE ACROSS THE SW VA MTNS TOWARD TN...SO HAVE 30ISH POPS HERE. ANOTHER AREA IS OVER THE RALEIGH-DURHAM AREA AND EAST...SO MAY SEE SOME SCATTERED STORMS TOWARD YANCEYVILLE. SE WINDS WILL BE KEEPING TEMPS FROM GETTING TOO HIGH...PLUS DEALING WITH POTENTIAL LOW CLOUDS INTO MORNING OVER THE EAST. HIGHS WILL MAY WORK OUT TO BE HOMOGENEOUS ACROSS THE ENTIRE CWA OUTSIDE THE HIGHER ELEVATIONS WITH LOWER TO MID 80S. SE FLOW DOWNSLOPE WARMING MAY INCREASE TEMPS OVER THE MTN EMPIRE BUT STORMS FIRING UP IN THE AFTERNOON SHOULD PREVENT IT FROM TOPPING OUT CLOSE TO THE MAV GUIDANCE OF UPPER 80S. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... AS OF 310 PM EDT THURSDAY... UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A SRN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL STREAK OVER THE GULF COAST STATES AND ACROSS THE WRN SLOPES OF THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SSE FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN THE EAST...MAINLY FROM THE ERN WV PANHANDLE SOUTHEAST TOWARD THE TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST WITH MID 80S WEST. SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER FRIDAY EVENING STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT LEAST SLIGHT CHANCE INTO THE MTNS LATE. SUNDAY LOOKS ACTIVE AS THE SHORTWAVE SHIFTS ACROSS KY INTO NRN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR IN THE WEST WHERE A FEW STORMS COULD PRODUCE GUSTY WINDS. HIGHS SUNDAY WILL RANGE FROM THE UPPER 70S MTNS TO UPPER 80S SE. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE GULF COAST STATES BY THE END OF THE FORECAST PERIOD. SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO AND THROUGH THE GREAT LAKES INTO NEW ENGLAND. HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED OVER THE AREA. GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME. PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64 BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR. PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER 80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 135 AM EDT FRIDAY... A STATIONARY FRONT EXTENDED FROM AROUND NORFOLK TO JUST SOUTH OF KDAN TO NORTHEAST TENNESSEE. EAST WINDS NORTH OF THE BOUNDARY WERE EXPECTED TO BRING A STRATUS LAYER IN FROM THE COAST. LOW CONFIDENCE AT THIS TIME THAT KLYH OR KDAN WILL DROP TO MVFR CEILINGS OR LOWER BEFORE 12Z/8AM. THE SKY WAS CLEAR AT KLWB AND WITH A SMALL TEMPERATURE/DEW POINT DEPRESSION...EXPECTING FOG WILL DEVELOP EARLY THIS MORNING. MEDIUM CONFIDENCE OF AT LEAST IFR VISIBILITY AT THIS AIRPORT AFTER 09Z/5AM. THERE WILL BE LITTLE CHANGE IN THE WEATHER PATTERN TODAY AND TONIGHT. THE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING WILL REMAIN SOUTH OF THE FORECAST AREA. NO MENTION OF SHOWERS OR THUNDERSTORMS NEEDED IN THE TAFS AT THIS TIME. EXTENDED DISCUSSION... WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION AGAIN ON SATURDAY...MAINLY DURING THE LATE AFTERNOON AND EARLY EVENING. SHOULD ONE OF THESE STORMS DEVELOP NEAR A TAF LOCATION IT COULD RESULT IN A BRIEF PERIOD OF SUB VFR CONDITIONS. AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND MONDAY. SHOWER COVERAGE SUNDAY/MONDAY IS EXPECTED TO BE MORE WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY. && .EQUIPMENT... AS OF 100 PM EDT THURSDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...REMAINS OUT OF SERVICE. A PART HAS BEEN ORDERED. REPAIRS WILL BE DONE THIS FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/WP NEAR TERM...PM/WP SHORT TERM...WP LONG TERM...WERT AVIATION...AMS/CF EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD. LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE 29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30 TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS MORNING. THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF 1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80 PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS. ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES. HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS THE FAR WESTERN SECTIONS SUNDAY AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE 500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80 PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60 PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND 40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN CHANCES WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1140 PM CDT THU AUG 28 2014 ALTHOUGH RAIN SHOWERS FROM EARLIER THIS EVENING HAVE MOVED NORTHEAST OF TAF AIRFIELDS...A SECONDARY AREA OF CONVECTION HAS DEVELOPED ACROSS CENTRAL IA. THESE STORMS ARE EXPECTED TO WEAKEN AS THEY MOVE NORTHEASTWARD...BUT SHOULD IMPACT KRST AND KLSE BETWEEN 29.08 AND 29.14Z. PERIODS OF HEAVY RAIN AND VISIBILITY RESTRICTIONS TO ONE MILE WILL BE THE PRIMARY IMPACTS. EXPECT MVFR/IFR CEILINGS TO PERSIST THROUGH THE NIGHT ONLY TO SLOWLY LIFT FRIDAY MORNING. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED FRIDAY AFTERNOON/EVENING WITH AN APPROACHING COLD FRONT. WILL CONTINUE TO HIGHLIGHT THIS THREAT USING TEMPO GROUPS UNTIL BETTER TIMING/COVERAGE CERTAINTY IS ACHIEVED. LIGHT SOUTHEAST WIND WILL GRADUALLY BECOME MORE SOUTHERLY THROUGH THE PERIOD. && .HYDROLOGY... ISSUED AT 309 AM CDT FRI AUG 29 2014 PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF 3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN PRODUCERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...ROGERS HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT THU AUG 28 2014 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 329 PM CDT THU AUG 28 2014 MAIN FOCUS FOR THE NEXT 24 TO 48 HOURS IS ON THE HEAVY RAINFALL POTENTIAL AS A FEW ROUNDS OF STORMS LIFT THROUGH THE UPPER MISSISSIPPI RIVER VALLEY. AS OF MID AFTERNOON...WATER VAPOR IMAGERY OVERLAID WITH RAP 500MB RAP HEIGHTS SHOWED THE SHORTWAVE TROUGH PUSHING OFF THE COLORADO ROCKIES WITH WEAK IMPULSES LIFTING THROUGH THE CENTRAL PLAINS TOWARD THE UPPER MIDWEST. ONE SUCH WAVE IS BRINGING THE SHIELD OF MAINLY RAIN SHOWERS THIS AFTERNOON...WHILE ANOTHER ONE IS NOTED NEAR THE TX PANHANDLE INTO SOUTHERN KANSAS. THIS ONE...ALONG WITH THE MAIN TROUGH...WILL BE OUR PLAYER FOR FRIDAY AFTERNOON AND EVENING. THE SURFACE HIGH PRESSURE ANCHORED OVER THE GREAT LAKES KEPT FLOW OF DRIER AIR...LIMITING THE FORWARD PROGRESS OF RAIN SHIELD. A LOT OF THE MOISTURE WENT INTO SATURATION...AND COMBINED WITH THE WEAKENING LLJ MOISTURE TRANSPORT FROM THIS MORNING...THE HEAVIER RAINFALL DID NOT MATERIALIZE. WITH THAT SAID...THE ENVIRONMENT WILL BEGIN TO BECOME MORE FAVORABLE TONIGHT AND RECENT 1-HR RAINFALL TOTALS HAVE BEEN GENERALLY 0.1 TO 0.2 INCH...WITH SOME ISOLATED 0.3-0.5 AMOUNTS. VERY LITTLE INSTABILITY FOUND ACROSS THE AREA WHICH IS KEEPING ACTIVITY AS SHOWERS/RAIN. WENT AHEAD AND LIMITED THUNDER CHANCES TO ISOLATED/SCATTERED THROUGH THE OVERNIGHT HOURS...ESPECIALLY MN/WI AREAS. IT WILL BE MORE STEADY RAINFALL. AS THE CURRENT SHIELD OF RAIN LIFTS NORTHEAST...EXPECTING THE BACK EDGES TO FILL IN SOME KEEPING THE HIGHER POPS IN PLACE THROUGH THE OVERNIGHT. THE TIMING OF ANY SPECIFIC UPPER LEVEL WAVES...WITH CONFLICTING STRENGTH IN MOISTURE TRANSPORT AND SURFACE FOCUS...LENDS A BIT LOWER CONFIDENCE IN WHERE HEAVIEST RAINFALL WILL FALL. WHAT HAS HIGHER CONFIDENCE IS THAT THE ATMOSPHERE SHOULD BETTER PRIMED FOR EFFICIENT RAIN PRODUCERS. NO CHANGES TO THE IDEA THAT PWATS ARE HIGH...WARM CLOUD DEPTHS ARE ABOVE 4 KM...AND THERE IS A CONTINUOUS FLOW OF MOISTURE STREAMING IN FROM THE SOUTHWEST IN ADVANCE OF THE SHORTWAVE. PERUSAL OF 28.12Z MODELS SHOW SIGNALS FOR ANOTHER IMPULSE TO SPARK CONVECTION OVERNIGHT ACROSS WESTERN INTO SOUTHWEST IOWA. THIS WOULD LIFT THROUGH NORTHEAST IOWA AND SOUTHEAST MINNESOTA EARLY MORNING. AFTER THE MORNING LLJ WEAKENS...THERE SEEMS TO NOT BE ANOTHER KICKER UNTIL LATE FRIDAY AFTERNOON AND EVENING. AS SUCH...THE LATE MORNING AND EARLY AFTERNOON HOURS COULD END UP DRIER...AND HAVE TRIED TO REFLECT THIS THINKING IN THE HOURLY POPS. THE MORE SIGNIFICANT WAVE ARRIVES FRIDAY AFTERNOON THROUGH THE EARLY MORNING HOURS SATURDAY. FINALLY THE MAIN SHORTWAVE TROUGH ENERGY WILL BE FELT...AND WITH A GOOD FEED OF MOISTURE TRANSPORT AND WARM AIR ADVECTION...THERE SHOULD BE WIDESPREAD SHOWERS AND ISOLATED/EMBEDDED THUNDERSTORMS THROUGHOUT FROM LATE AFTERNOON ONWARD. ALTHOUGH THE FAVORABLE ATMOSPHERIC CONDITIONS WILL BE IN PLACE FOR HEAVY RAINFALL TOMORROW...THE LACK OF HIGHER RAINFALL TOTALS TODAY DAMPENS THE OVERALL FLASH FLOODING THREAT. RAINFALL TOTALS THROUGH SATURDAY HAVE BEEN TEMPERED A BIT...AND ARE MORE IN THE 1-2 INCH RANGE. A LOT OF THE AREA CAN TAKE THIS TYPE OF RAINFALL. OF COURSE LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE...BUT FEEL THE OVERALL THREAT IS REDUCED COMPARED TO THE THINKING IN THE PAST 24 HOURS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 PM CDT THU AUG 28 2014 THE MAIN FOCUS IN THE LONG TERM IS CENTERED ON THE THREAT FOR SEVERE WEATHER SUNDAY NIGHT INTO MONDAY. WITH THE HOLIDAY WEEKEND APPROACHING...AND WITH MANY FOLKS PLANNING OUTDOOR ACTIVITIES...IT IS THIS PERIOD THAT WARRANTS CLOSE WATCHING. IN THE UPPER LEVELS...THE 28.12Z GUIDANCE FOLLOWED THE PAST SEVERAL MODEL CYCLES IN SHOWING A DIGGING WESTERN CONUS LONGWAVE TROUGH APPROACHING THE NORTHERN PLAINS BY SUNDAY EVENING. 250MB JET DYNAMICS PUTS THE AREA IN A FAVORABLE RIGHT ENTRANCE REGION...AND THIS JET STRENGTHENS BETWEEN 00-06Z MONDAY. AT THE SURFACE...A COLD FRONT LOOKS LIKELY TO MOVE ACROSS MINNESOTA LATE SUNDAY NIGHT...REACHING THE MISSISSIPPI RIVER EARLY MONDAY MORNING. MUCAPE RANGES FROM 1500 TO 2000 J/KG ACROSS THE REGION LATE SUNDAY...WITH HEALTHY PROFILES AS NCAPE VALUES APPROACH 0.15. THIS IS AIDED BY 700-500MB LAPSE RATES AROUND 7.5C/KM. THE SHEAR ENVIRONMENT IS A BIT MUDDLED BETWEEN THE VARIOUS GUIDANCE...BUT OVERALL 0-3KM SHEAR VALUES RANGE FROM 20 TO 30 KTS. HODOGRAPHS SHOW SOME CURVATURE BUT A LOT OF THE SHEAR IS SPEED RELATED. OVERALL...THE CURRENT TIMING WOULD SUGGEST CONVECTION TO DEVELOP IN THE AFTERNOON ACROSS THE EASTERN DAKOTAS / WESTERN INTO CENTRAL MINNESOTA...POSSIBLY AS SUPERCELLS...THEN MERGE IN LINE SEGMENTS TOWARD THE WESTERN CWA IF MAINTAINED. THERE ARE STRONG MOISTURE TRANSPORT SIGNALS WITH HIGHER PWATS RETURNING...SO THERE COULD BE SOME HEALTHY RAIN PRODUCERS. THE MAIN LIMITING FACTOR WOULD BE STORM SPEED...WHICH SHOULD BE RATHER PROGRESSIVE. REGARDLESS...MAIN THREATS LOOK TO BE HEAVY RAIN...DAMAGING WINDS...AND LARGE HAIL. AT THIS TIME...GIVEN TIMING...WEST OF THE MS RIVER WOULD BE MORE FAVORABLE AND THIS LINES UP WELL WITH THE CURRENT DAY 4 OUTLOOK FROM THE SPC. OVERALL...WILL NEED TO WATCH THIS PERIOD. THE FRONT SLIDES INTO WESTERN WISCONSIN MONDAY MORNING...WHICH MAY ALLOW FOR ANOTHER ROUND OF DESTABILIZATION AND STRONG STORMS FOR OUR EASTERN AREAS MONDAY AFTERNOON. THAT IS A BIT MORE UNCERTAIN BUT IF THE SYSTEM SLOWS DOWN...WHICH SEEMS TO BE A TREND...THIS PERIOD MAY NEED TO BE WATCHED CLOSER. THE TUESDAY-THURSDAY PERIOD LOOKS TO FEATURE ZONAL UPPER LEVEL FLOW WITH THE POSSIBILITY OF A FEW RIPPLES SLIDING THROUGH. NOT MUCH CONSISTENCY IN THE MODEL RUNS TO ADD ANY DETAILS AT THIS POINT. LOTS OF WEATHER TO GET THROUGH UNTIL THEN. SLIGHT CHANCES WITH SEASONABLE TEMPERATURES LOOKS GOOD AT THIS POINT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1140 PM CDT THU AUG 28 2014 ALTHOUGH RAIN SHOWERS FROM EARLIER THIS EVENING HAVE MOVED NORTHEAST OF TAF AIRFIELDS...A SECONDARY AREA OF CONVECTION HAS DEVELOPED ACROSS CENTRAL IA. THESE STORMS ARE EXPECTED TO WEAKEN AS THEY MOVE NORTHEASTWARD...BUT SHOULD IMPACT KRST AND KLSE BETWEEN 29.08 AND 29.14Z. PERIODS OF HEAVY RAIN AND VISIBILITY RESTRICTIONS TO ONE MILE WILL BE THE PRIMARY IMPACTS. EXPECT MVFR/IFR CEILINGS TO PERSIST THROUGH THE NIGHT ONLY TO SLOWLY LIFT FRIDAY MORNING. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED FRIDAY AFTERNOON/EVENING WITH AN APPROACHING COLD FRONT. WILL CONTINUE TO HIGHLIGHT THIS THREAT USING TEMPO GROUPS UNTIL BETTER TIMING/COVERAGE CERTAINTY IS ACHIEVED. LIGHT SOUTHEAST WIND WILL GRADUALLY BECOME MORE SOUTHERLY THROUGH THE PERIOD. && .HYDROLOGY...THROUGH SATURDAY MORNING ISSUED AT 329 PM CDT THU AUG 28 2014 WITH LESS THAN EXPECTED RAINFALL TODAY...OVERALL TOTALS THROUGH SATURDAY HAVE BEEN REDUCED TO THE 1.5 TO 2.5 INCH RANGE. THE SURGE IN EFFICIENT RAIN PRODUCING ATMOSPHERIC CONDITIONS...CHARACTERIZED BY WARM CLOUD DEPTHS 3.5 TO 4.0 KM...PWATS 1.5 TO 2.0 INCHES...AND LOWER 70F DEWPOINTS...WILL REMAIN IN PLACE THROUGH EARLY SATURDAY. OVERALL...THE THREAT FOR EXCESSIVE RAINFALL HAS BEEN DIMINISHED A BIT AS THE ROUNDS OF STORMS LOOK PROGRESSIVE ENOUGH AND MUCH OF THE AREA CAN HANDLE THE EXPECTED AMOUNTS. AS SUCH...WILL CONTINUE THE HYDROLOGIC OUTLOOK /ESFARX/ && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ZT LONG TERM....ZT AVIATION...ROGERS HYDROLOGY....ZT
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
1013 AM EDT FRI AUG 29 2014 .SYNOPSIS... A BUILDING UPPER RIDGE WILL KEEP VERY WARM TEMPERATURES IN THE FORECAST THROUGH EARLY NEXT WEEK. MOISTURE WILL INCREASE OVER THE WEEKEND INTO EARLY NEXT WEEK BRINGING BACK A LOW CHANCE OF AFTERNOON THUNDERSTORMS AND HIGHER HUMIDITY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... BACKDOOR COLD FRONT PUSHED INTO SOUTHERN NORTH CAROLINA OVERNIGHT AND LOOKS TO BE SITUATED FROM NEAR GREENVILLE TO LANCASTER EASTWARD TOWARDS NEWPORT NC WITH SURFACE WINDS FROM THE NORTH BEHIND THE FRONT. MOST OF THE ATMOSPHERIC MOISTURE IS POOLED ALONG THE BOUNDARY WITH THE BEST 925MB MOISTURE ACROSS SOUTHERN NC AND HIGHEST PRECIPITABLE WATER ALSO EXTENDING ACROSS CENTRAL NORTH CAROLINA. HIGH RESOLUTION MODEL DATA FROM HRRR AND SPC WRF INDICATE ISOLATED CONVECTION IN THE VICINITY OF THE FRONT OVER SOUTHERN NC BUT THE FORECAST AREA SHOULD REMAIN RAIN FREE ONCE AGAIN. THE BOUNDARY IS QUITE SHALLOW AND LIKELY WILL MIX OUT AND BECOME RE-ESTABLISHED FURTHER NORTH OVER CENTRAL NC BY AFTERNOON. TEMPERATURES TODAY WILL QUICKLY RISE THROUGH THE 80S AND PEAK IN THE MID TO POSSIBLE UPPER 90S THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... UNDER MOSTLY CLEAR SKIES AND A SLIGHT INCREASE IN LOW-LEVEL MOISTURE...LOWS TONIGHT WILL ONLY FALL INTO THE UPPER 60S. FOR SATURDAY THE UPPER RIDGE REMAINS ACROSS THE AREA. MUCH OF THE FORECAST AREA SHOULD REMAIN DRY ONCE AGAIN ON SATURDAY. LOW-LEVEL MOISTURE CONTINUES TO INCREASE THROUGH THE DAY...BUT THE BEST MOISTURE AND RAIN SHOULD REMAIN ACROSS THE EXTREME WESTERN PORTIONS OF THE CWA. WILL CARRY A SLIGHT CHANCE FOR RAIN ACROSS THE WEST...BUT CONFIDENCE NOT HIGH. MODELS CONTINUE TO TREND DRIER FOR SATURDAY. CONTINUE WARM TEMPERATURES AS READINGS REMAIN ABOVE NORMAL. FOR SATURDAY NIGHT...WILL HOLD ONTO THE SLIGHT CHANCE EARLY IN THE EVENING...THEN EXPECTING CONDITIONS TO DRY OUT FOR THE REMAINDER OF THE NIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... UPPER RIDGE CONTINUES OVER THE AREA THROUGH THE EXTENDED PERIOD. LOW-LEVEL MOISTURE CONTINUES TO SLOWLY INCREASE THROUGH THE REMAINDER OF THE WEEKEND AND INTO EARLY NEXT WEEK WITH SOUTHEAST FLOW OFF THE ATLANTIC. EXPECT A LOW CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE MIDDLE OF NEXT WEEK. AT THIS TIME IT APPEARS THAT ANY SHOWERS AND THUNDERSTORMS WILL BE MAINLY DIURNALLY DRIVEN WITH LITTLE UPPER LEVEL FORCING. TEMPERATURES WILL CONTINUE ABOVE NORMAL THROUGH THE REMAINDER OF THE LONG TERM PERIOD. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... ATMOSPHERE REMAINS DRY. EXPECT VFR CONDITIONS TODAY. AN UPPER RIDGE AND DRY AND CAPPED ATMOSPHERE WILL REMAIN IN PLACE AND CONTINUE TO PRECLUDE ANY CONVECTION CONCERNS. LIGHT SOUTHEAST WINDS EXPECTED THROUGH THE PERIOD. FOG LOOKS TO BE MORE LIKELY TONIGHT AS LOW LEVEL MOISTURE INCREASES WITH THE SOUTHEAST FLOW. EXTENDED AVIATION OUTLOOK...LATE NIGHT AND EARLY MORNING STRATUS AND FOG POSSIBLE. SCATTERED MAINLY AFTERNOON THUNDERSTORMS SUNDAY THROUGH TUESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ NEAR TERM...HC AVIATION...HC
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
648 AM EDT Fri Aug 29 2014 ...Updated Forecast and Aviation Discussions... ...Forecast Update... Issued at 635 AM EDT Fri Aug 29 2014 Seeing a few light returns just north of our IN counties. These are developing on the north edge of a theta-e ridge currently over KHNB. Latest RUC keeps this going on for a few more hours before the frontal lift dominates the rest of the morning. Added in some isolated showers over the west this morning before switching over to storms this afternoon over the northeast. Rest of forecast pretty much on track. Climate Note: BWG received 1.16 inches of rain, bringing their monthly total to 9.26". This total is the second wettest August on record for that station. An additional 0.08" over the next 3 days will tie the record, set back in 1926. .SHORT TERM (Now through Saturday)... Issued at 300 AM EDT Fri Aug 29 2014 Weak frontal boundary is roughly located along our southern border this hour. This boundary is forecast to lift northward today, with a wind shift from easterly ahead of it to southerly behind it. Lift along this front as well as instability from late afternoon heating should produce isolated to scattered storms, with the best chance over southern Indiana and the Bluegrass region of Kentucky. The stronger storms will produce brief gusty winds and heavy rain. Those storms should exit to the northeast this evening before another round comes in from the west late tonight. This action will be as a low-level jet aids in development over the Bootheel region that will shift eastward toward daybreak. Precipitable water values will climb to near 2 inches during the day. The main focus for heavier storms will be along another front to our northwest, but any heating over our region should be able to produce scattered storms. The main problem with these storms will be the torrential rainfall, given the high atmospheric moisture. Storm motion vectors indicate enough motion that we should be able to avoid flash flooding, but areas that receive multiple rounds of storms could see some minor flooding, especially in poor drainage areas. Temperatures will continue above normal this period. .LONG TERM (Saturday Night through Thursday)... Issued at 300 AM EDT Fri Aug 29 2014 ...Unsettled Weather Through the Holiday Weekend and into Next Week... Multiple rounds of shower and thunderstorms are expected through the long term with storms likely for a portion of the holiday weekend. A weakening upper level trough will cross the upper Midwest Saturday and move into the Great Lakes region by Sunday morning. Another vortmax will track northeast through the upper level flow and into the Lower Ohio Valley Saturday night into Sunday. At the surface southerly flow will remain in place with high pressure centered off the east coast. The best chance for showers and storms during the long term will be right at the beginning on Saturday night and Sunday as the upper level disturbances move through the area. Wind fields are not overly impressive, but a few strong storms will be possible with gusty winds. However, soundings do reveal a very saturated atmosphere with PWAT values rising to over 2 inches. Long skinny CAPE is also suggestive of very heavy rain. Storms should be moving somewhat quicker than previous episodes of heavy rain we have seen this month. However, given torrential rainfall potential from storms, if there is any training some minor flooding issues will be possible. This would particularly be a concern in urban areas. Another vortmax will set off another round of showers and storms Monday afternoon. With drier air filtering in at mid levels PWATs will drop Monday and heavy rainfall should be less of a concern. By Tuesday a frontal boundary will drop south towards the area from the north. This boundary looks to get hung up north of the forecast area, though the models do have some differences in the details towards the end of the forecast period. Regardless, scattered showers and storms will be possible through Thursday along and south of this front. Temperatures for the most part will be in the mid 80s to lower 90s. The exception will be Sunday. With all the clouds and precipitation in the area temperatures will top out in the lower to mid 80s. Lows will be in the upper 60s to lower 70s. && .AVIATION (12Z TAF Update)... Issued at 645 AM EDT Fri Aug 29 2014 KBWG had a few clouds go over the last couple of hours, which generally has kept them in the MVFR range for vsby. Could still get an hour or two of IFR conditions down there before going VFR the rest of the day. May see some light showers west of KSDF by late morning. The best chance for a storm there would be in the mid afternoon, but chance is still low enough to keep out of TAFs at this point. Better chance continues to be at KLEX, as a front moves north across the region and combines with daytime heating to produce scattered storms. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........RJS Short Term.....RJS Long Term......EER Aviation.......RJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1133 AM EDT FRI AUG 29 2014 LATEST UPDATE... UPDATE/MARINE .SYNOPSIS... ISSUED AT 325 AM EDT FRI AUG 29 2014 SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE TODAY AS A WARM FRONT MOVES THROUGH THE AREA. MORE WIDESPREAD THUNDERSTORM ACTIVITY IS EXPECTED SATURDAY AHEAD OF THE COLD FRONT...WHICH COMES THROUGH EARLY SUNDAY MORNING. BEHIND THE COLD FRONT ON SUNDAY EXPECT PARTIAL CLEARING BY AFTERNOON. THEN A STRONG COLD FRONT WILL BRING THE RISK OF ADDI TONAL STORMS MONDAY. && .UPDATE... ISSUED AT 1130 AM EDT FRI AUG 29 2014 LOWERED TEMPERATURES SLIGHTLY AND ADDED A RISK FOR THUNDERSTORMS THIS AFTERNOON. ELEVATED INSTABILITY MOVES IN FOR THE AFTERNOON. ALSO RADAR SHOWS CONVECTION CROSSING THE LAKE. CLOUDS WILL LIKELY LIMIT HIGH TEMPERATURES TODAY. WARMEST READINGS MAY BE LATER IN THE AFTERNOON WHEN WE WILL POTENTIALLY SEE MORE SUN. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 325 AM EDT FRI AUG 29 2014 WE ARE TRACKING SHOWERS AND THUNDERSTORMS TODAY THROUGH SATURDAY NIGHT. WHILE THERE COULD BE SOME SHOWERS AND ISOLATED THUNDERSTORMS AROUND TODAY....IT WOULD SEEM OUR BEST POTENTIAL FOR WIDESPREAD CONVECTION IS SATURDAY AS THE UPPER WAVE MOVES THROUGH. THE BIG PICTURE FINDS A OPENING UP SOUTHERN STREAM CLOSED UPPER LOW MOVING EAST AS IT SHEARS OUT AND MOVES OVER MICHIGAN DURING THE DAY TIME SATURDAY. THE MODELS AS NEARLY ALWAYS WEAK THESE FEATURE TO FAST SO I WOULD EXPECT STRONG DYNAMICS SATURDAY THEN ANY OF THE MODELS CURRENTLY WOULD SUGGEST. IN ANY EVENT AS THIS UPPER WAVE HEADS TOWARD MICHIGAN IT DISPLACES A SHORTWAVE RIDGE CURRENTLY IN PLACE OVER MICHIGAN. THAT RESULTS IN A SURGE OF MID LEVEL MOISTURE THAT SHOULD LEAD TO SOME SHOWER AND THUNDERSTORM ACTIVITY OVER THE WESTERN AND NORTHER SECTIONS OF THE CWA TODAY. THEN THE PASSAGE OF THE MAIN SYSTEM SATURDAY WILL BRING MORE WIDESPREAD CONVECTION TO THE AREA. LOOKING AT THE 1000/850 MOISTURE TRANSPORT VECTORS FROM THE GFS...NAM AND ECMWF FOR TODAY THE STORY THEY TELL IS SIMILAR TO WHAT THEY SHOWED YESTERDAY AND THE DAY BEFORE THAT. FOR THE MOST PART THE BEST MOISTURE TRANSPORT WILL BE NORTH AND WEST OF THE GRR CWA TODAY. THE LOW LEVEL JET AXIS IS WEST OF MICHIGAN EARLY THIS MORNING AND IS MOSTLY OVER NORTHERN LOWER AND UPPER MICHIGAN THIS AFTERNOON INTO TONIGHT. ALSO THE INSTABILITY IS RATHER LIMITED AND WHAT THERE IS OF IT IS MOSTLY OVER WESTERN SECTIONS OF LOWER MICHIGAN INTO THIS AFTERNOON. THE SHORTWAVE RIDGE AHEAD OF THE UPPER WAVE HAS BROUGHT TO WARM OF AIR ABOVE 700 MB SO THAT VERTICAL TOTALS ARE MARGINAL AT BEST FOR THUNDERSTORMS TODAY. WHAT BRING THE SHOWERS TO THE AREA TODAY IS A SURGE OF MID LEVEL MOISTURE AS THE PRECIPITABLE WATER SURGES FROM UNDER A SEVEN TENTS OF AN INCH EARLY THIS MORNING TO ABOVE ONE AND THREE QUARTER INCHES OVER MOST OF THE CWA BY NOON. THE FOCUS OF THIS WILL BE ON THE WARM FRONT NEAR THE AXIS OF THE LOW LEVEL JET. THAT MEANS MOST OF THE CONVECTION WILL BE NORTH AND WEST OF THE GRR CWA TODAY. SATURDAY IS WHEN THE MAIN UPPER WAVE MOVES THROUGH THE AREA AND THERE IS WORKABLE LOW LEVEL JET IN THE AREA AND SOME UPPER LEVEL JET SUPPORT SO WE SHOULD HAVE WIDESPREAD SHOWERS AND A FEW NON SEVERE THUNDERSTORMS (CAPE IS LIMITED AND DEEP LAYER SHEAR IS WEAK TOO). ALL OF THIS MOVES OUT SATURDAY NIGHT AND SUNDAY FINES US WITH SHORT WAVER RIDING. SO I EXPECT CLEARING TO OCCUR DURING THE DAY SUNDAY AS DRY AIR MOVES IN FROM THE NORTHWEST. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM EDT FRI AUG 29 2014 THE MAIN WEATHER IN THE LONG TERM WILL BE FOCUSED ON THE CONVECTION CHCS EARLY ON IN THE PERIOD WITH A SYSTEM THAT WILL BE MOVING THROUGH THE AREA. THE AREA WILL SEE A BREAK IN THE WEATHER FOR SUN NIGHT IN THE WAKE OF THE DEPARTING SYSTEM FROM SAT/SAT NIGHT...AND WELL OUT AHEAD OF THE SYSTEM POISED TO MOVE THROUGH THE AREA ON MON. THE BREAK WILL BE A SHORT ONE AS THE STORM CHCS WILL BE INCREASING ON MON MORNING AND LASTING INTO MON EVENING. SHORT WAVE ENERGY EXPECTED TO COME ONSHORE ACROSS OREGON ON SAT WILL TRAVERSE THE COUNTRY OVER THE HOLIDAY WEEKEND AND WILL BE LIFTING INTO ONTARIO BY MON AFTERNOON. THE SHORT WAVE REMAINS MAINLY NORTH OF THE AREA. HOWEVER THE ASSOCIATED LLJ AND STRONG MOISTURE TRANSPORT DOES MOVE RIGHT INTO THE AREA MON. WE ENVISION A RESIDUAL LINE OF SHOWERS/ STORMS COMING INTO THE AREA FROM THE WEST ON MON...AND STRENGTHENING AS IT ENCOUNTERS AN INCREASINGLY UNSTABLE AIR MASS WITH DIURNAL HEATING THAT TAKES PLACE. WE CAN NOT RULE SOME OF THE STORMS BECOMING SEVERE MON. DEEP LAYER SHEAR WILL BE ON THE INCREASE WITH THE UPPER JET NEARBY. LI/S ARE EXPECTED TO DROP DOWN AROUND -6C WITH CAPES APPROACHING OVER 1500 J/KG. THE LLJ OVERHEAD WILL INCREASE THE 0-3 KM SHEAR WHICH WILL HELP THE CAUSE. THE LIMITATIONS OF POSSIBLE SEVERE WEATHER WOULD BE LIMITED INSTABILITY IF NOT MUCH HEATING CAN TAKE PLACE...AND NOT IDEAL UPPER JET DYNAMICS OVERHEAD. MOST OF THE REST OF THE WEEK SHOULD BE RATHER QUIET AND SEASONABLE FOR THE AREA. SOME RESIDUAL CHCS OF PCPN WILL HOLD ON TUE UNTIL THE SECONDARY SHORT WAVE MOVES THROUGH. AFTER THAT...WE GET INTO A NEARLY ZONAL FLOW WITH LOWER MICHIGAN JUST DOWNSTREAM OF SOME RIDGING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 740 AM EDT FRI AUG 29 2014 ALL OF THE HIGH RESOLUTION MODELS (HRRR 09Z AND RAP 10Z) SHOW THE AREA OF SCATTERED SHOWERS OVER LAKE MICHIGAN BECOMING A SOLID AREA OF SHOWERS WITH EMBEDDED HEAVER RAIN SHOWERS (INSTABILITY QUESTIONABLE FOR THUNDERSTORMS). THE AREA OF SHOWERS WILL IMPACT THE TAF SITES FROM AROUND 15Z TILL AROUND 21Z BEFORE DISSIPATING. I ALSO ADDED MVFR CIGS AFTER 07Z IN THE WESTERN TAF SITES TO REFLECT INCREASED LOW LEVEL MOISTURE ADVECTION AS THE UPPER SHORTWAVE GETS CLOSER TO LOWER MICHIGAN. SO EXPECT MVFR VSBY/CIGS IN SHOWERS AT MOST OF THE TAR SITES FROM 15Z TILL 19Z....THEN BECOMING VFR. && .MARINE... ISSUED AT 1130 AM EDT FRI AUG 29 2014 KEPT THE HAZARDS GOING. SOUTHEAST WINDS BECOME MORE SOUTHERLY AND INCREASE. THIS SHOULD RESULT IN WAVES POTENTIALLY CLIMBING ABOVE 4 FT. && .HYDROLOGY... ISSUED AT 328 PM EDT THU AUG 28 2014 THE HEAVY RAIN THREAT APPEARS TO BE LIMITED TO THE MUSKEGON AND PERE MARQUETTE BASINS AS AN INCH OF QPF CAN BE EXPECTED THERE BY SUNDAY MORNING...WHICH WOULD RESULT IN RISES BY EARLY NEXT WEEK. MUCH LESS RAIN IS EXPECTED IN THE GRAND AND KALAMAZOO RIVER BASINS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM 8 PM EDT THIS EVENING THROUGH SATURDAY EVENING FOR MIZ037-043-050-056-064-071. LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT SATURDAY FOR LMZ848-849. SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 11 PM EDT SATURDAY FOR LMZ844>847. && $$ UPDATE...MJS SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...NJJ AVIATION...WDM HYDROLOGY...OSTUNO MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
742 AM EDT FRI AUG 29 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 325 AM EDT FRI AUG 29 2014 SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE TODAY AS A WARM FRONT MOVES THROUGH THE AREA. MORE WIDESPREAD THUNDERSTORM ACTIVITY IS EXPECTED SATURDAY AHEAD OF THE COLD FRONT...WHICH COMES THROUGH EARLY SUNDAY MORNING. BEHIND THE COLD FRONT ON SUNDAY EXPECT PARTIAL CLEARING BY AFTERNOON. THEN A STRONG COLD FRONT WILL BRING THE RISK OF ADDI TONAL STORMS MONDAY. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 325 AM EDT FRI AUG 29 2014 WE ARE TRACKING SHOWERS AND THUNDERSTORMS TODAY THROUGH SATURDAY NIGHT. WHILE THERE COULD BE SOME SHOWERS AND ISOLATED THUNDERSTORMS AROUND TODAY....IT WOULD SEEM OUR BEST POTENTIAL FOR WIDESPREAD CONVECTION IS SATURDAY AS THE UPPER WAVE MOVES THROUGH. THE BIG PICTURE FINDS A OPENING UP SOUTHERN STREAM CLOSED UPPER LOW MOVING EAST AS IT SHEARS OUT AND MOVES OVER MICHIGAN DURING THE DAY TIME SATURDAY. THE MODELS AS NEARLY ALWAYS WEAK THESE FEATURE TO FAST SO I WOULD EXPECT STRONG DYNAMICS SATURDAY THEN ANY OF THE MODELS CURRENTLY WOULD SUGGEST. IN ANY EVENT AS THIS UPPER WAVE HEADS TOWARD MICHIGAN IT DISPLACES A SHORTWAVE RIDGE CURRENTLY IN PLACE OVER MICHIGAN. THAT RESULTS IN A SURGE OF MID LEVEL MOISTURE THAT SHOULD LEAD TO SOME SHOWER AND THUNDERSTORM ACTIVITY OVER THE WESTERN AND NORTHER SECTIONS OF THE CWA TODAY. THEN THE PASSAGE OF THE MAIN SYSTEM SATURDAY WILL BRING MORE WIDESPREAD CONVECTION TO THE AREA. LOOKING AT THE 1000/850 MOISTURE TRANSPORT VECTORS FROM THE GFS...NAM AND ECMWF FOR TODAY THE STORY THEY TELL IS SIMILAR TO WHAT THEY SHOWED YESTERDAY AND THE DAY BEFORE THAT. FOR THE MOST PART THE BEST MOISTURE TRANSPORT WILL BE NORTH AND WEST OF THE GRR CWA TODAY. THE LOW LEVEL JET AXIS IS WEST OF MICHIGAN EARLY THIS MORNING AND IS MOSTLY OVER NORTHERN LOWER AND UPPER MICHIGAN THIS AFTERNOON INTO TONIGHT. ALSO THE INSTABILITY IS RATHER LIMITED AND WHAT THERE IS OF IT IS MOSTLY OVER WESTERN SECTIONS OF LOWER MICHIGAN INTO THIS AFTERNOON. THE SHORTWAVE RIDGE AHEAD OF THE UPPER WAVE HAS BROUGHT TO WARM OF AIR ABOVE 700 MB SO THAT VERTICAL TOTALS ARE MARGINAL AT BEST FOR THUNDERSTORMS TODAY. WHAT BRING THE SHOWERS TO THE AREA TODAY IS A SURGE OF MID LEVEL MOISTURE AS THE PRECIPITABLE WATER SURGES FROM UNDER A SEVEN TENTS OF AN INCH EARLY THIS MORNING TO ABOVE ONE AND THREE QUARTER INCHES OVER MOST OF THE CWA BY NOON. THE FOCUS OF THIS WILL BE ON THE WARM FRONT NEAR THE AXIS OF THE LOW LEVEL JET. THAT MEANS MOST OF THE CONVECTION WILL BE NORTH AND WEST OF THE GRR CWA TODAY. SATURDAY IS WHEN THE MAIN UPPER WAVE MOVES THROUGH THE AREA AND THERE IS WORKABLE LOW LEVEL JET IN THE AREA AND SOME UPPER LEVEL JET SUPPORT SO WE SHOULD HAVE WIDESPREAD SHOWERS AND A FEW NON SEVERE THUNDERSTORMS (CAPE IS LIMITED AND DEEP LAYER SHEAR IS WEAK TOO). ALL OF THIS MOVES OUT SATURDAY NIGHT AND SUNDAY FINES US WITH SHORT WAVER RIDING. SO I EXPECT CLEARING TO OCCUR DURING THE DAY SUNDAY AS DRY AIR MOVES IN FROM THE NORTHWEST. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM EDT FRI AUG 29 2014 THE MAIN WEATHER IN THE LONG TERM WILL BE FOCUSED ON THE CONVECTION CHCS EARLY ON IN THE PERIOD WITH A SYSTEM THAT WILL BE MOVING THROUGH THE AREA. THE AREA WILL SEE A BREAK IN THE WEATHER FOR SUN NIGHT IN THE WAKE OF THE DEPARTING SYSTEM FROM SAT/SAT NIGHT...AND WELL OUT AHEAD OF THE SYSTEM POISED TO MOVE THROUGH THE AREA ON MON. THE BREAK WILL BE A SHORT ONE AS THE STORM CHCS WILL BE INCREASING ON MON MORNING AND LASTING INTO MON EVENING. SHORT WAVE ENERGY EXPECTED TO COME ONSHORE ACROSS OREGON ON SAT WILL TRAVERSE THE COUNTRY OVER THE HOLIDAY WEEKEND AND WILL BE LIFTING INTO ONTARIO BY MON AFTERNOON. THE SHORT WAVE REMAINS MAINLY NORTH OF THE AREA. HOWEVER THE ASSOCIATED LLJ AND STRONG MOISTURE TRANSPORT DOES MOVE RIGHT INTO THE AREA MON. WE ENVISION A RESIDUAL LINE OF SHOWERS/ STORMS COMING INTO THE AREA FROM THE WEST ON MON...AND STRENGTHENING AS IT ENCOUNTERS AN INCREASINGLY UNSTABLE AIR MASS WITH DIURNAL HEATING THAT TAKES PLACE. WE CAN NOT RULE SOME OF THE STORMS BECOMING SEVERE MON. DEEP LAYER SHEAR WILL BE ON THE INCREASE WITH THE UPPER JET NEARBY. LI/S ARE EXPECTED TO DROP DOWN AROUND -6C WITH CAPES APPROACHING OVER 1500 J/KG. THE LLJ OVERHEAD WILL INCREASE THE 0-3 KM SHEAR WHICH WILL HELP THE CAUSE. THE LIMITATIONS OF POSSIBLE SEVERE WEATHER WOULD BE LIMITED INSTABILITY IF NOT MUCH HEATING CAN TAKE PLACE...AND NOT IDEAL UPPER JET DYNAMICS OVERHEAD. MOST OF THE REST OF THE WEEK SHOULD BE RATHER QUIET AND SEASONABLE FOR THE AREA. SOME RESIDUAL CHCS OF PCPN WILL HOLD ON TUE UNTIL THE SECONDARY SHORT WAVE MOVES THROUGH. AFTER THAT...WE GET INTO A NEARLY ZONAL FLOW WITH LOWER MICHIGAN JUST DOWNSTREAM OF SOME RIDGING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 740 AM EDT FRI AUG 29 2014 ALL OF THE HIGH RESOLUTION MODELS (HRRR 09Z AND RAP 10Z) SHOW THE AREA OF SCATTERED SHOWERS OVER LAKE MICHIGAN BECOMING A SOLID AREA OF SHOWERS WITH EMBEDDED HEAVER RAIN SHOWERS (INSTABILITY QUESTIONABLE FOR THUNDERSTORMS). THE AREA OF SHOWERS WILL IMPACT THE TAF SITES FROM AROUND 15Z TILL AROUND 21Z BEFORE DISSIPATING. I ALSO ADDED MVFR CIGS AFTER 07Z IN THE WESTERN TAF SITES TO REFLECT INCREASED LOW LEVEL MOISTURE ADVECTION AS THE UPPER SHORTWAVE GETS CLOSER TO LOWER MICHIGAN. SO EXPECT MVFR VSBY/CIGS IN SHOWERS AT MOST OF THE TAR SITES FROM 15Z TILL 19Z....THEN BECOMING VFR. && .MARINE... ISSUED AT 325 AM EDT FRI AUG 29 2014 WE WILL BE HOISTING A SMALL CRAFT ADVISORY FOR THE NRN MARINE ZONES FOR TODAY AND LASTING THROUGH SAT. WE WILL ALSO HOIST A SMALL CRAFT ADVISORY FOR THE REMAINDER OF THE ZONES FOR TONIGHT AND SAT. THE GRADIENT WILL BE INCREASING AHEAD OF THE INCOMING SYSTEM OUT OF THE SOUTH. THIS WILL LAST INTO SAT EVENING BEFORE IT DIMINISHES A BIT. && .HYDROLOGY... ISSUED AT 328 PM EDT THU AUG 28 2014 THE HEAVY RAIN THREAT APPEARS TO BE LIMITED TO THE MUSKEGON AND PERE MARQUETTE BASINS AS AN INCH OF QPF CAN BE EXPECTED THERE BY SUNDAY MORNING...WHICH WOULD RESULT IN RISES BY EARLY NEXT WEEK. MUCH LESS RAIN IS EXPECTED IN THE GRAND AND KALAMAZOO RIVER BASINS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT FROM THIS EVENING THROUGH SATURDAY EVENING FOR MIZ037-043-050-056-064-071. LM...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT SATURDAY FOR LMZ848-849. SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 11 PM EDT SATURDAY FOR LMZ844>847. && $$ SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...NJJ AVIATION...WDM HYDROLOGY...OSTUNO MARINE...NJJ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
614 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT FRI AUG 29 2014 RATHER UGLY MORNING OUT THERE IN TERMS OF AVIATION...WITH PLENTIFUL AMOUNTS OF LOW CIGS AND FOG OUT AHEAD OF A WARM FRONT THAT WAS STARTING TO MAKE PROGRESS NORTH INTO MN AND AT 3 AM WAS NEAR THE I-90 CORRIDOR. BESIDE THE LOW CLOUDS...ISENTROPIC LIFT AND ELEVATED INSTABILITY ADVECTION ASSOCIATED WITH A MODEST 20-30 KT SWRLY LLJ HAS ALLOWED FOR AN AREA SHOWERS/THUNDERSTORMS TO MOVE NNE ACROSS THE AREA. THE HRRR HAS HAD A GOOD HANDEL ON THIS ACTIVITY OVERNIGHT...AND FOLLOWED IT FAIRLY CLOSELY TO TIME THIS MORNINGS BATCH OF ACTIVITY THROUGH THE AREA. THIS BATCH OF RAIN LOOKS TO BE MOSTLY NORTH OF THE MPX AREA BY 15Z...WITH A BRIEF BREAK IN PRECIP EXPECTED UNTIL THUNDERSTORMS GET GOING AGAIN LATER IN THE AFTERNOON. FOR THE AFTERNOON...WE WILL BE DEALING WITH A RATHER MESSY SFC PATTERN AS THE MESO LOW CURRENTLY NEAR SIOUX FALLS WASHES OUT OVER MN AS IT GETS ABSORBED BY THE MAIN COLD FRONT...WHICH WAS STILL BACK ACROSS WRN NODAK. BIGGEST CHANGE SEEN FROM THE 28.12 TO THE 29.00 MODEL RUNS WAS A WHOLESALE SLOWING OF THE FRONT/SFC TROUGH ACROSS THE AREA. THIS HAS RESULTED IN HIGHER POPS BEING PUSHED BACK WEST THIS AFTERNOON...AS WHAT WAS LOOKING LIKE WAS MAINLY GOING TO BE A SHOW FOR AREAS ALONG/EAST OF I-35 IS NOW MORE OF AN ALONG/EAST OF A ST. CLOUD TO FAIRMONT LINE. THE HI-RES MODELS THAT LOOK TO ADHERE TO WHAT IS SEEN FORCING WISE WITH THE DETERMINISTIC MODELS THE BEST ARE THE 29.00 NMM AND MPX WRFS...WHICH BOTH SHOW STORMS FORMING WEST OF THE TWIN CITIES BETWEEN 19-21Z AND MOVING EAST FROM THERE AS A BROKEN LINE OF STORMS. ONE THING THAT HAS NOT CHANGED...IS THE MOST WIDESPREAD RAIN/HIGHEST AMOUNTS LOOK TO FALL ACROSS SE MN/WRN WI AS THE AFTERNOON ACTIVITY TO THE WEST OF I-35 CONGEALS INTO A BROADER MASS EAST OF I-35. STILL NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER TODAY EITHER...AS CLOUD COVER LOOKS TO BE EXTENSIVE...WHICH WILL LIMIT THE DEGREE OF DESTABILIZATION WE SEE BY THE AFTERNOON. IN ADDITION...MID LEVEL LAPSE RATES WILL REMAIN RATHER WEAK...FURTHER POINTING TO INSTABILITY SOMEWHAT LACKING WHEN IT COMES TO THE SEVERE WEATHER POTENTIAL. BESIDE THE INSTABILITY...THE SFC PATTERN LOOKS TO BE RATHER DIFFUSE...WITH NO CLEAR FOCUS EXISTING FOR THUNDERSTORM ACTIVITY /SEE FRONT SUNDAY FOR A CLEAR FOCUS FOR THUNDERSTORM DEVELOPMENT/. WITH THAT SAID...BULK SHEAR WILL BE UP IN THE 30-40 KT RANGE AHEAD OF THE SFC TROUGH...SUFFICIENT ENOUGH TO ALLOW FOR A MULTI-CELL CLUSTER OR TWO TO PULSE UP ENOUGH TO POSE AN ISOLATED WIND/HAIL THREAT TODAY. FOR HIGHS TODAY...THERE IS ADMITTEDLY SOME BUST POTENTIAL WITH THE CURRENT FORECAST OF HIGHS IN THE 70S AS THAT IS PREDICATED ON CLOUD COVER BEING DOMINATE TODAY. IF WE INSTEAD GET SOME DECENT SUN BEFORE STORMS DEVELOP THIS AFTERNOON...THEN HIGHS IN THE LOWER/MID 80S WILL BE MORE COMMON. FOR TONIGHT...SHOWER AND THUNDERSTORM ACTIVITY LOOKS SLOWLY CLEAR OUT TO THE EAST...WITH TO MUCH LEFT OUTSIDE OF SOME DRIZZLE IN WRN WI BY 12Z SATURDAY. HOWEVER...THE SFC THROUGH/FRONT WILL BE VERY SLOW IN WORKING ACROSS THE AREA...WITH PLENTIFUL LOW LEVEL MOISTURE LOOKING TO HANG AROUND MOST OF THE NIGHT. THIS SHOULD ALLOW FOR ANOTHER ROUND OF LOW STRATUS AND FOG TO EXPAND ACROSS THE AREA TONIGHT...WHICH IN TURN WILL HELP KEEP LOWS UP MAINLY IN THE MID/UPPER 60S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 338 AM CDT FRI AUG 29 2014 THE MAIN STORY IN THE EXTENDED IS THE SYSTEM EXPECTED SUNDAY AFTERNOON AND SUNDAY NIGHT WITH THE HIGH LIKELIHOOD OF WIDESPREAD THUNDERSTORMS AND THE POTENTIAL FOR SEVERE WEATHER. THE RAIN SHOULD CLEAR EARLY ON LABOR DAY...LEAVING MAINLY DRY WEATHER ACROSS THE FORECAST AREA THROUGH AT LEAST MID WEEK. THE TROUGH EXPECTED TO MOVE ACROSS THE NORTHERN CONUS SUN-MON AND BRING WIDESPREAD THUNDERSTORMS TO THE NATION`S MID SECTION IS ALREADY AN ESTABLISHED CIRCULATION WITH A WELL-DEFINED PV FEATURE IN THE GULF OF ALASKA THIS MORNING. THE TROUGH WILL DIG SOUTHEAST OVER THE NEXT 48 HOURS AND DEVELOP MORE OF A NEGATIVE TILT BEFORE LIFTING NORTH TOWARD HUDSON BAY MONDAY NIGHT. THE JET STRUCTURE SUPPORTS WIDESPREAD UPPER DIVERGENCE AND 500MB 12-HR HEIGHT FALLS BETWEEN 80-100M SLIP ACROSS NORTHERN MN SUNDAY NIGHT. LOWER IN THE ATMOSPHERE...850-700MB FGEN INCREASES IN WESTERN MN NEAR OR JUST AFTER 18Z ON SUNDAY. THE BOUNDARY MAKES GRADUAL PROGRESS TO THE EAST FROM 18Z SUNDAY UNTIL 12Z MONDAY. A SLOWLY DEEPENING AND EASTWARD-MOVING SURFACE CYCLONE PRODUCES 4-6MB 6-HR MSLP PRESSURE FALLS ACROSS THE FORECAST AREA ON SUNDAY. CONVECTIVE INITIATION SHOULD NOT BE A PROBLEM...IN FACT...STORMS SHOULD ALREADY BE ONGOING IN THE EASTERN DAKOTAS SATURDAY MORNING. ELEVATED CONVECTION SHOULD TRANSITION TO MORE SURFACE BASED CONVECTION WITH HEATING AND THE LIKELY ESTABLISHMENT OF LARGE LINE SEGMENTS OR CLUSTERS OF THUNDERSTORMS DUE TO THE LARGE-SCALE FORCING. THE DEEP LAYER SHEAR SHOULD BE GOOD ENOUGH TO ORGANIZE STORMS INTO MULTI-CELL WITH EMBEDDED SUPERCELLS /EVEN IF THEY EXIST IN LINES/. THE INSTABILITY SHOULD BE SUFFICIENT TO SUPPORT STRONG UPDRAFTS. IT LOOKS PRIMARILY LIKE A WIND AND HAIL THREAT IN THE AFTERNOON AND EVENING HOURS ACROSS MN. BOTH THE NAM AND GFS HAVE 0-3KM SHEAR ON THE ORDER OF 25-40KTS FROM 18Z-06Z ACROSS THE FORECAST AREA. THE SEVERE THREAT DIMINISHES IN WI GIVEN THE LOSS OF INSTABILITY SUNDAY NIGHT AND QUICKLY NORTHWARD LIFTING SURFACE LOW. BEYOND THE WEEKEND...THE TROUGH FLATTENS OUT AND WE`RE LEFT WITH A RELATIVELY DRY AND COOL WESTERLY FLOW PATTERN THROUGH AT LEAST MID WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 557 AM CDT FRI AUG 29 2014 THE RAP CAUGHT ON TO THE VFR CONDITIONS MOVING NORTH OUT OF SOUTHERN MN PRETTY QUICK THIS MORNING...AND FOLLOWED IT/S IDEA FOR BRINGING VFR CONDITIONS UP INTO ERN MN/WRN WI. WITH THE SFC LOW MOVING INTO SW MN...WILL TAKE A BIT LONGER FOR AXN TO SEE IMPROVEMENTS. FOR TSRA THIS AFTERNOON...FOLLOWED THE TRENDS OF HRRR/MPXWRF/NMMWRF...WHICH ARE ALL PRETTY SIMILAR WITH THEIR HANDLING OF TSRA THIS AFTERNOON/EVENING. STORMS LOOK TO DEVELOP BETWEEN 18Z AND 20Z NEAR/EAST OF A RWF TO STC LINE AND MOVE EAST FROM THERE. BEHIND THE AFTERNOON STORMS...THE PRESSURE GRADIENT LOOKS WEAK...WITH THE MAIN COLD FRONT AND ITS DRY AIR STILL HUNG UP NORTHWEST OF THE MPX CWA. THIS MEANS WE WILL HAVE ANOTHER NIGHT WITH VLIFR/LIFR CIGS. GIVEN LOW LEVEL WINDS...STRATUS IS MOST LIKELY IN MN...BUT WINDS WILL BE LIGHT ENOUGH IN WRN WI TO LEAD TO HEIGHTENED THREAT FOR FOG AT RNH/EAU. KMSP...VFR CONDITIONS MOVING UP FROM THE SOUTH LOOK TO BE HERE TO STAY FOR THE REST OF THE MORNING GIVEN THE FACT WE HAVE NOT SEEN CIGS FILL BACK IN ACROSS SRN MN/NRN IA...SO WILL KEEP CIGS VFR UNTIL TONIGHT. FRONTAL BOUNDARY FOR THE AFTERNOON IS LOOKING SLOWER IN GETTING HERE...ALLOWING CONFIDENCE TO BE QUITE HIGH IN MSP SEEING ANOTHER ROUND OF TSRA THIS AFTERNOON. TONIGHT...AGAIN THERE IS HIGH CONFIDENCE IN ANOTHER ROUND OF IFR STRATUS...JUST A QUESTION OF HOW QUICKLY DOES IT COME IN AND HOW LOW DOES IT GO. /OUTLOOK FOR KMSP/ SAT...VFR. WIND NNE AT 5-10 KTS. SUN...VFR WITH MVFR/TSRA LATE. WINDS SSE AT 10-20 KTS. MON...MVFR/TSRA ENDING EARLY. VFR BY AFTNOON WINDS W 10-15KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1012 AM CDT Fri Aug 29 2014 .UPDATE... Issued at 1012 AM CDT FRI AUG 29 2014 Quick update this morning to account for latest radar and satellite trends. Fairly potent upper-level wave inbound this morning as seen on latest water vapor imagery. Ahead of this feature...upper- level pressure along the 1.5 PVU surface showing a nice "treble clef" signature with latest RUC analysis showing the trop undulation down to almost 500-mb...not bad for this time of year! Pressure advection in advance of this feature combined with decent upper divergence aloft should continue to support organized shwrs and thunderstorms. As this feature continues sliding east this morning...expect a gradual increase in precip chances from west to east which should result in very beneficial rainfall for a good portion of the area. In general...QPF totals will likely range from a quarter to half inch...with localized higher amounts possible with thunderstorm activity. Pop/wx grids updated to reflect a slightly delayed arrival time...but overall fcst trends remain unchanged. && .SHORT TERM...(Today through Sunday) Issued at 326 AM CDT FRI AUG 29 2014 For today, areas of scattered thunderstorms will continue to develop along and ahead of an eastward-moving shortwave trough, resulting in slowly increasing chances of precipitation this morning into the evening across the CWA. The best chance of storms will spread from early afternoon across eastern KS and far western MO to late evening in central MO. Afternoon temperatures will be held down by clouds and precipitation, keeping highs mainly in the 80s and the highest readings in central MO where storms will be later to arrive. Not much instability is expected to develop today with clouds arriving early and temperatures aloft and no real significant temperature perturbation along the trough to increase lapse rates, so do not expect much of a strong/severe storm threat this afternoon or this evening. However, if areas of central MO see a few peeks of sun through early afternoon, an isolated more robust storm could develop and could produce briefly gusty winds. Precipitation will generally clear out from northwest to southeast on Friday night, but may linger into Saturday across portions of central MO as a second weak shortwave trough rides up over central MO, especially if the weak surface boundary associated with today`s shortwave trough can stall over the region and support convective initiation on Saturday. High temperatures should be several degrees warmer for Saturday and especially Sunday as skies clear, southerly surface flow returns, and 850 hPa temperatures remain in the 18 to 21 C range. The next round of thunderstorms is expected to be a bit more robust Sunday night into early Monday morning along a southeastward moving cold front. General model consensus brings the front through the CWA between midnight and 9 AM Monday morning, although timing could change a bit. MUCAPE values in the 1000-2000 J/kg range and bulk shear values as high as 40 kts could support organized, potentially strong multicell storms especially across northwest MO. Heavy rain is also a threat with PWATs climbing to around 2 inches and bulk shear vectors orienting parallel to the front to support training storms. The overall severe threat will depend on timing of frontal passage as storms should become elevated with time and instability will decrease, but is expected mainly across northwest and northern MO where upper-level forcing and flow is a bit stronger. .LONG TERM...(Monday through Thursday) Issued at 326 AM CDT FRI AUG 29 2014 A complex of showers and thunderstorms will likely be ongoing over portions of the forecast area Monday morning as a cold front settles into northwest Missouri. While not an optimal diurnal time for severe weather with only modest instability forecast, will need to monitor potential as dynamics from the large upper trough over the northern tier of the country will yield moderate shear in advance of the cold front. The upper trough will gradually deamplify, leaving the surface cold front largely stationary Monday into Tuesday across the northern half of the CWA. Periodic thunderstorm chances will remain possible through Tuesday night as the region remains on the southern periphery of strong upper dynamics and associated embedded shortwave troughs traversing the area. A few storms may be strong with moderate shear and instability, especially during the afternoon and evening hours. With the boundary layer winds expected to remain weak, the primary threat would be brief periods of damaging wind gusts and hail to quarter-size. Pinpointing the timing and specific locations of highest precipitation potential remains challenging at this stage with convective details that will play some role in frontal position and windows of strongest ascent both unresolved. The surface boundary is expected to retreat northward as a warm front by Wednesday as heights begin to rise across the region. Only a slight chance of thunderstorms is anticipated on Wednesday, with dry conditions for the remainder of the work week. Likewise, temperatures will return to above normal readings, with afternoon highs in the upper 80s to lower 90s. && .AVIATION...(For the 12Z TAFS through 12Z Saturday Morning) Issued at 628 AM CDT FRI AUG 29 2014 VFR conditions are expected through most of the morning and early afternoon across the region; however, a few isolated storms could form in the vicinity of all TAF sites by 14z-17z along with scattered to broken 4-5 kft ceilings. Showers and storms should become more numerous across western MO this afternoon, then should push out of the terminals between 00z-03z. Winds will become light and variable early Saturday morning, resulting in patchy fog that could become dense in places. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...32 SHORT TERM...Laflin LONG TERM...Blair AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
658 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 THE PRIMARY FORECAST CHALLENGES WILL BE IN REGARDS TO PCPN CHANCES TODAY INTO TONIGHT AND THEN TIMING THE NEXT ROUND OF CONVECTION SUNDAY INTO SUNDAY NIGHT. SOME SEVERE STORMS WILL BE POSSIBLE MAINLY FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING. MAIN FEATURES FROM THE UPPER AIR CHARTS LAST EVENING INCLUDED THE FOLLOWING. AT 300 MB A JET SEGMENT OF AROUND 70 KNOTS WAS PUNCHING NORTHEAST FROM SOUTHWEST KS. THIS WAS AHEAD OF A 500 MB TROUGH THAT STRETCHED FROM THE DAKOTAS DOWN INTO WEST TEXAS. 12 HOUR HEIGHT FALLS OF UP TO AROUND 40 METERS WERE NOTED AT AMARILLO AND DODGE CITY. DECENT MOISTURE WAS STILL IN PLACE AT 700 MB AND 850 MB AHEAD OF THE MID LEVEL TROUGH. THE KOAX SOUNDING WAS STILL FAIRLY MOIST WITH 1.70 PRECIPITABLE WATER. SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER SOUTHEAST SOUTH DAKOTA AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW INTO WEST TEXAS. DEWPOINTS WERE IN THE 60S TO LOWER 70S. WATER VAPOR LOOP EARLY THIS MORNING SHOWED THAT THE TROUGH TO OUR WEST HAD MADE SOME EASTWARD PROGRESS SINCE LAST EVENING. IT SHOULD CONTINUE TO HAVE AN IMPACT ON US UNTIL A LITTLE AFTER MIDNIGHT TONIGHT. KEPT FAIRLY HIGH POPS GOING TODAY...SINCE WE SHOULD SEE REDEVELOPMENT THIS AFTERNOON WITH DAYTIME HEATING. FORECAST SOUNDINGS FROM THE 00Z NAM INDICATED ELEVATED INSTABILITY OF OVER 2000 J/KG BY AROUND NOON. RECENT RUNS OF THE RAP MODEL SHOW AN INCREASE IN PCPN COVERAGE AFTER 1 PM. HIGHS WILL BE MAINLY IN THE UPPER 70S AND LOWER 80S. LOWS TONIGHT SHOULD DROP TO THE LOWER AND MID 60S AS DRIER AIR WORKS ITS WAY IN FROM THE NORTHWEST BEHIND THE COLD FRONT. SOME PATCHY FOG COULD DEVELOP LATE TONIGHT...BUT OVERALL THE ATMOSPHERE WILL BE DRYING OUT. SATURDAY LOOKS LIKE A DECENT DAY WITH A FAIR AMOUNT OF SUNSHINE AND HIGHS IN THE 80S. CLOUDS WILL START TO INCREASE SATURDAY NIGHT... ESPECIALLY IN OUR FAR WESTERN ZONES. KEPT A SMALL CHANCE OF LATE NIGHT TSTMS IN NORTHEAST NEBRASKA. MODELS HAVE SOME TIMING DIFFERENCES FOR SUNDAY INTO SUNDAY NIGHT. KEPT SOME LOW POPS LATE SATURDAY NIGHT WEST OF A LINE FROM WAYNE TO COLUMBUS. 00Z RUNS OF THE NAM AND CANADIAN MODEL WERE A BIT SLOWER WITH DEVELOPMENT OF STORMS SUNDAY AFTERNOON. FOR NOW...BLENDED IN SOME OF THE GFS AND ECMWF WHICH SHOW SOME RAINFALL AMOUNTS OVER A QUARTER OF AN INCH SUNDAY AFTERNOON. IF THE NAM IS MORE CORRECT... THE SEVERE WEATHER POTENTIAL IS PROBABLY HIGHER SUNDAY EVENING THAN IF THE GFS AND ECMWF VERIFY BETTER. LOOK FOR HIGHS MAINLY IN THE 80S AND MAYBE NEAR 90 FOR PARTS OF SOUTHEAST NEBRASKA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 TRENDED POPS DOWNWARD SUNDAY NIGHT FROM NORTHWEST TO SOUTHEAST AS THE SYSTEM MOVES THROUGH...BUT LINGERED A SLIGHT CHANCE OF TSTMS INTO MONDAY MORNING. A 500 MB LONGWAVE TROUGH AXIS WILL BE LOCATED OVER THE EASTERN ROCKIES AND WESTERN HIGH PLAINS AT THE BEGINNING OF THIS PERIOD. BY TUESDAY...THAT SHIFTS EAST OF OUR AREA AND THEN THE FLOW IS FAIRLY ZONAL ACROSS MID AMERICA INTO WEDNESDAY. LATER IN THE WEEK ANOTHER TROUGH WILL DIG INTO THE PACIFIC NORTHWEST...WITH OUR AREA UNDER THE INFLUENCE OF SOUTHWEST MID LEVEL FLOW. ALTHOUGH THUNDERSTORM CHANCES WILL NOT BE COMPLETELY ABSENT...NEXT WEEK SHOULD BE A LOT DRIER THAN THIS WEEK HAS BEEN. HIGHS WILL MODERATE FROM MAINLY 80S TO AROUND 90 AND LOWS WILL INCREASE FROM 60S TO AROUND 70 OR THE LOWER 70S. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 624 AM CDT FRI AUG 29 2014 LATEST OBS SHOWING MID LVL CIGS PREVAILING OVER ERN NEB THIS MORNING WITH -SHRA MOVING NWD OUT OF ERN KS. EXPECT ACTIVITY WILL DIMINISH WITHIN THE NEXT COUPLE HOURS...THUS HAVE ADDED TEMPO GROUPS TO KOMA/KLNK. MEANWHILE...A STALLED FRONTAL BNDRY EXTENDING FROM NW IA TO CNTRL KS WILL BE THE FOCUS FOR CONVECTIVE REDEVELOPMENT LATE THIS AFTN. AREAL COVERAGE IS IN QUESTION AT THIS POINT...THUS OPTED FOR PROB30 GROUPS. VFR CONDITIONS THEN DURING THE EVENING AND OVERNIGHT HOURS. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...DEE
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1001 AM EDT FRI AUG 29 2014 .SYNOPSIS... SURFACE HIGH PRESSURE TRANSLATING EASTWARD ACROSS NEW YORK AND NEW ENGLAND WILL BRING PLEASANT AND DRY WEATHER CONDITIONS TO THE NORTH COUNTRY TODAY AND TONIGHT. WARMER AND MORE HUMID WEATHER WILL RETURN FOR THE WEEKEND AS HIGH PRESSURE SHIFTS EAST OF THE REGION AND SOUTH TO SOUTHWEST FLOW DEVELOPS. SATURDAY SHOULD BE PRECIPITATION FREE... BUT SHOWERS AND THUNDERSTORMS ARE LIKELY SUNDAY AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES INTO THE REGION FROM THE GREAT LAKES. SOME THUNDERSTORMS ON SUNDAY ARE EXPECTED TO PRODUCE BRIEF HEAVY DOWNPOURS. ABOVE NORMAL TEMPERATURES...WITH VALLEY HIGHS GENERALLY IN THE 80S...WILL CONTINUE THROUGH MOST OF NEXT WEEK. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... AS OF 954 AM EDT FRIDAY...HIGH PRESSURE WILL CONTINUE TO CREST OVER THE REGION TODAY BRINGING A MOSTLY SUNNY DAY TO MUCH OF THE AREA. STILL HAVE A LOW STRATUS DECK TRAPPED UNDER THE SUBSIDENCE INVERSION AND NORTHERLY FLOW IN THE CHAMPLAIN VALLEY AND ALONG THE WESTERN SLOPES OF THE GREEN MOUNTAINS. THIS HAS BEEN BEGINNING TO SHRINK OVER THE PAST 1-2 HOURS. ALSO STARTING TO SEE OTHER AREAS MIX OUT AS INDICATED BY DAYTIME CUMULUS FORMING IN PARTS OF EASTERN VERMONT. THUS EXPECTING THE CHAMPLAIN VALLEY STRATUS TO CLEAR OUT AROUND 16Z (NOON). LATEST RAP/HRRR/4KM NAM SUPPORT THIS TIMING AS WELL. TEMPERATURES WARMING UP NICELY IN AREAS THAT ARE SEEING SUN...SO HIGHS FROM 70 TO 75 STILL LOOK GOOD. PREVIOUS DISCUSSION FROM 740 AM FRIDAY... MODERATELY STRONG SURFACE ANTICYCLONE AND ASSOCIATED MID- TROPOSPHERIC RIDGE WILL BUILD EWD INTO THE NORTH COUNTRY TODAY. LINGERING STRATOCUMULUS ACROSS NRN VT AND IN THE CHAMPLAIN VALLEY WILL DISSIPATE THRU 15-16Z (PER RAP LOW-LEVEL RH TRENDS) OWING TO INCREASED SUBSIDENCE AND PBL MIXING...AND PATCHY EARLY AM FOG WILL QUICKLY DISSIPATE AFTER 12Z WITH NEAR FULL SUNSHINE EXPECTED TODAY. WINDS WILL BE LIGHT AND VARIABLE IN VICINITY OF HIGH PRESSURE...AND DEWPOINTS WILL REMAIN LOW - GENERALLY IN THE UPPER 40S TO LOWER 50S. LEANED TOWARD WARMER NAM- MOS GUIDANCE...WITH VALLEY HIGHS IN THE 72-76F RANGE. ALL IN ALL A VERY PLEASANT DAY FOR OUTDOOR ACTIVITIES UNDER RESPLENDENT BLUE SKIES. SURFACE HIGH PRESSURE REMAINS IN CONTROL TONIGHT WILL DRIFTING EWD TOWARD THE GULF OF MAINE AFTER MIDNIGHT. AS A RESULT...SHOULD SEE SOME SOUTHERLY RETURN FLOW DEVELOP LATE...ESPECIALLY IN THE CHAMPLAIN VALLEY WITH CHANNELING EFFECTS. WINDS GENERALLY AROUND 10 MPH IN THE CHAMPLAIN VALLEY...BUT WITH STEEP LAPSE RATES OVER LAKE CHAMPLAIN DUE TO WARM LAKE WATERS...WILL SEE THE DEVELOPMENT OF 15-25 KT SOUTH WINDS BY 09Z OVER THE OPEN WATERS OF LAKE CHAMPLAIN. MODELS SUGGEST INCREASING RH IN 300-500MB LAYER...SO WILL LIKELY SEE AN INCREASE IN CIRRUS FROM WEST TO EAST OVERNIGHT. NO PRECIPITATION IS EXPECTED. FOG WILL BE MOST PREVALENT ACROSS THE VALLEYS OF CENTRAL AND ERN VT WHERE WINDS JUST ABOVE THE PBL WILL BE LIGHTEST AND CIRRUS CLOUDS WILL ARRIVE A BIT LATER. OVERNIGHT LOWS WILL GENERALLY BE IN THE LOW-MID 50S...WITH A FEW UPPER 40S IN THE NRN ADIRONDACKS AND FAR NERN VT. && .SHORT TERM /11 PM THIS EVENING THROUGH SUNDAY/... AS OF 329 AM EDT FRIDAY...SOUTH TO SOUTHWESTERLY LOW-LEVEL FLOW WILL BE IN PLACE ACROSS THE NORTH COUNTRY ON SATURDAY...BETWEEN SFC HIGH PRESSURE DEPARTING TO THE EAST AND A WEAK SFC LOW AND MID- LEVEL TROUGH ACROSS THE GREAT LAKES. MODERATE LOW-TO-MID LEVEL WAA IS PROGGED BY 00Z NAM/GFS...WITH 850MB THERMAL RIDGE OF +15 TO +16C BUILDING INTO THE REGION BY 00Z SUNDAY. ISSUE ON TEMPERATURE WILL BE CLOUDS...AS HIGH 500-300MB RH SUGGESTS FILTERED SUNSHINE THROUGH CIRRUS/ALTOSTRATUS LAYER. ADJUSTED A BIT ABOVE MOS CONSENSUS...WITH HIGHS IN THE 80-83F FOR MOST VALLEY SECTIONS...BUT NOT QUITE AS WARM AS IT COULD BE UNDER FULL SUN. S-SW WINDS GENERALLY 10-15 MPH. WITH MID-LEVEL RIDGING STILL IN PLACE AND NOT MUCH EVIDENCE FOR LOW- LEVEL CONVERGENCE...IT APPEARS SATURDAY WILL REMAIN DRY AREAWIDE...AND WILL KEEP POPS BELOW 15 PERCENT. DEWPOINTS WILL SLOWLY CLIMB...LIKELY REACHING THE UPR 50S. WEAK MID-LEVEL HEIGHT FALLS COMMENCE SATURDAY NIGHT AS MID-LEVEL SHORTWAVE TROUGH PROGRESSES EWD ACROSS THE GREAT LAKES. SHOULD SEE MOSTLY CLOUDY SKIES...WITH A CHANCE FOR A FEW SHOWERS DEVELOPING ACROSS NRN NY...AND PERHAPS FAR NRN VT TOWARD DAYBREAK SUNDAY. CLOUDS AND CONTINUED LIGHT SOUTH WINDS SAT NIGHT...COMBINED WITH WARMER AIR MASS WILL RESULT IN VERY MILD OVERNIGHT LOWS...RANGING FROM THE UPR 50S ACROSS THE CT RIVER VALLEY...TO 65-68F IN THE CHAMPLAIN AND ST. LAWRENCE VALLEYS. SUNDAY LOOKS LIKE THE BEST CHANCE FOR PRECIPITATION OVER THE NEXT SEVERAL DAYS. SHORTWAVE TROUGH PROVIDES MID-LEVEL UVV WHILE WEAK SURFACE-BASED INSTABILITY DEVELOPS WITH DAYTIME HEATING (SBCAPE VALUES OF 500-1000 J/KG). DEEP LAYER SHEAR IS NOT PARTICULARLY IMPRESSIVE...WITH SFC-6KM BULK SHEAR OF ONLY 20-25 KTS. COMBINED WITH ONLY WEAK INSTABILITY WITH ABUNDANT CLOUD COVER IN PLACE...NOT ANTICIPATING ANY SEVERE WEATHER ACTIVITY. THAT SAID...SHOWER AND THUNDERSTORM ACTIVITY WILL GRADUALLY BECOME MORE WIDESPREAD TOWARD AFTERNOON WITH PEAK HEATING. WHILE NOT A "WASHOUT"...THESE SHOWERS COULD BE LOCALLY HEAVY...AS PW VALUES APPROACH 2.00" IN BOTH THE NAM AND GFS. HAVE INCLUDED HEAVY DOWNPOUR MENTION IN THE HAZARDOUS WEATHER OUTLOOK AND IN THE FORECAST GRIDS. DEFINITELY WOULD BE GOOD TO HAVE AN INDOOR BACKUP PLAN FOR ANY PLANNED OUTINGS ON SUNDAY GIVING POTENTIAL FOR BRIEF HEAVY RAINFALL. HIGH TEMPERATURES WILL RANGE FROM THE UPR 70S TO LOWER 80S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 329 AM EDT FRIDAY...FAIRLY ACTIVE WEATHER EXPECTED FOR THE FIRST PART OF THE EXTENDED FORECAST PERIOD...SUNDAY NIGHT THROUGH TUESDAY NIGHT...WITH DRYING TAKING PLACE WEDNESDAY AND THURSDAY. COLD FRONT MOVES ACROSS THE AREA SUNDAY NIGHT AND THUS GOING FORECAST OF LIKELY SHOWERS AND THUNDERSTORMS LOOKS REAL GOOD. NOT MUCH AIR MASS CHANGE BEHIND THE FRONT ON MONDAY AND THUS SUFFICIENT INSTABILITY SHOULD DEVELOP MONDAY AFTERNOON FOR SOME SHOWERS AND STORMS TO DEVELOP. A BRIEF BREAK IN THE CONVECTION TAKES PLACE LATER MONDAY NIGHT AND TUESDAY MORNING BEFORE ANOTHER COLD FRONT MOVES INTO THE REGION TUESDAY AFTERNOON. THUS LOOKING AT ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH TUESDAY EVENING BEFORE DRIER WESTERLY FLOW ALOFT DEVELOPS OVER THE AREA WEDNESDAY AND THURSDAY. THERMAL PROFILE THROUGHOUT THE EXTENDED SUGGESTS DAYTIME HIGHS WILL BE AT OR A FEW DEGREES ABOVE SEASONAL NORMALS. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... THROUGH 12Z SATURDAY...VFR-MVFR CEILINGS WILL EXIST THROUGH ABOUT 16Z BEFORE ALL SITES BECOME VFR WITH VERY LITTLE IN THE WAY OF ANY CLOUDS FOR THE REMAINDER OF THE PERIOD. IFR-LIFR VISIBILITIES WILL EXIST AT KSLK THROUGH 14Z BEFORE BECOMING VFR LIKE ALL OTHER SITES FOR THE REMAINDER OF THE PERIOD. WINDS WILL GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD. OUTLOOK 12Z SATURDAY THROUGH TUESDAY... 12Z SAT ONWARD...MAINLY VFR...WITH MVFR/BRIEF IFR IN SCATTERED SHOWERS AND THUNDERSTORMS. && .MARINE... SOUTH WINDS WILL INCREASE SHARPLY ON LAKE CHAMPLAIN TOWARD DAYBREAK SATURDAY...AS THE PRESSURE GRADIENT INCREASES BETWEEN HIGH PRESSURE DEPARTING EAST OF NEW ENGLAND...AND A DEVELOPING LOW PRESSURE SYSTEM ACROSS THE CENTRAL GREAT LAKES. LOOKING AT WINDS 15-20 KNOTS WITH GUSTS TO 25 KNOTS AFTER 5 AM...WITH SUSTAINED SOUTH WINDS 15-25 KNOTS THROUGH MUCH OF THE DAYLIGHT HOURS ON SATURDAY. WAVES OVER THE BROAD PORTION OF LAKE CHAMPLAIN WILL BUILD TO 2 TO 3 FEET SATURDAY MORNING. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/MUCCILLI SHORT TERM...BANACOS LONG TERM...EVENSON AVIATION...EVENSON/KGM MARINE...TEAM BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
748 AM EDT FRI AUG 29 2014 .SYNOPSIS... SURFACE HIGH PRESSURE TRANSLATING EASTWARD ACROSS NEW YORK AND NEW ENGLAND WILL BRING PLEASANT AND DRY WEATHER CONDITIONS TO THE NORTH COUNTRY TODAY AND TONIGHT. WARMER AND MORE HUMID WEATHER WILL RETURN FOR THE WEEKEND AS HIGH PRESSURE SHIFTS EAST OF THE REGION AND SOUTH TO SOUTHWEST FLOW DEVELOPS. SATURDAY SHOULD BE PRECIPITATION FREE... BUT SHOWERS AND THUNDERSTORMS ARE LIKELY SUNDAY AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES INTO THE REGION FROM THE GREAT LAKES. SOME THUNDERSTORMS ON SUNDAY ARE EXPECTED TO PRODUCE BRIEF HEAVY DOWNPOURS. ABOVE NORMAL TEMPERATURES...WITH VALLEY HIGHS GENERALLY IN THE 80S...WILL CONTINUE THROUGH MOST OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 740 AM EDT FRIDAY...MODERATELY STRONG SURFACE ANTICYCLONE AND ASSOCIATED MID-TROPOSPHERIC RIDGE WILL BUILD EWD INTO THE NORTH COUNTRY TODAY. LINGERING STRATOCUMULUS ACROSS NRN VT AND IN THE CHAMPLAIN VALLEY WILL DISSIPATE THRU 15-16Z (PER RAP LOW-LEVEL RH TRENDS) OWING TO INCREASED SUBSIDENCE AND PBL MIXING...AND PATCHY EARLY AM FOG WILL QUICKLY DISSIPATE AFTER 12Z WITH NEAR FULL SUNSHINE EXPECTED TODAY. WINDS WILL BE LIGHT AND VARIABLE IN VICINITY OF HIGH PRESSURE...AND DEWPOINTS WILL REMAIN LOW - GENERALLY IN THE UPPER 40S TO LOWER 50S. LEANED TOWARD WARMER NAM- MOS GUIDANCE...WITH VALLEY HIGHS IN THE 72-76F RANGE. ALL IN ALL A VERY PLEASANT DAY FOR OUTDOOR ACTIVITIES UNDER RESPLENDENT BLUE SKIES. SURFACE HIGH PRESSURE REMAINS IN CONTROL TONIGHT WILL DRIFTING EWD TOWARD THE GULF OF MAINE AFTER MIDNIGHT. AS A RESULT...SHOULD SEE SOME SOUTHERLY RETURN FLOW DEVELOP LATE...ESPECIALLY IN THE CHAMPLAIN VALLEY WITH CHANNELING EFFECTS. WINDS GENERALLY AROUND 10 MPH IN THE CHAMPLAIN VALLEY...BUT WITH STEEP LAPSE RATES OVER LAKE CHAMPLAIN DUE TO WARM LAKE WATERS...WILL SEE THE DEVELOPMENT OF 15-25 KT SOUTH WINDS BY 09Z OVER THE OPEN WATERS OF LAKE CHAMPLAIN. MODELS SUGGEST INCREASING RH IN 300-500MB LAYER...SO WILL LIKELY SEE AN INCREASE IN CIRRUS FROM WEST TO EAST OVERNIGHT. NO PRECIPITATION IS EXPECTED. FOG WILL BE MOST PREVALENT ACROSS THE VALLEYS OF CENTRAL AND ERN VT WHERE WINDS JUST ABOVE THE PBL WILL BE LIGHTEST AND CIRRUS CLOUDS WILL ARRIVE A BIT LATER. OVERNIGHT LOWS WILL GENERALLY BE IN THE LOW-MID 50S...WITH A FEW UPPER 40S IN THE NRN ADIRONDACKS AND FAR NERN VT. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... AS OF 329 AM EDT FRIDAY...SOUTH TO SOUTHWESTERLY LOW-LEVEL FLOW WILL BE IN PLACE ACROSS THE NORTH COUNTRY ON SATURDAY...BETWEEN SFC HIGH PRESSURE DEPARTING TO THE EAST AND A WEAK SFC LOW AND MID- LEVEL TROUGH ACROSS THE GREAT LAKES. MODERATE LOW-TO-MID LEVEL WAA IS PROGGED BY 00Z NAM/GFS...WITH 850MB THERMAL RIDGE OF +15 TO +16C BUILDING INTO THE REGION BY 00Z SUNDAY. ISSUE ON TEMPERATURE WILL BE CLOUDS...AS HIGH 500-300MB RH SUGGESTS FILTERED SUNSHINE THROUGH CIRRUS/ALTOSTRATUS LAYER. ADJUSTED A BIT ABOVE MOS CONSENSUS...WITH HIGHS IN THE 80-83F FOR MOST VALLEY SECTIONS...BUT NOT QUITE AS WARM AS IT COULD BE UNDER FULL SUN. S-SW WINDS GENERALLY 10-15 MPH. WITH MID-LEVEL RIDGING STILL IN PLACE AND NOT MUCH EVIDENCE FOR LOW- LEVEL CONVERGENCE...IT APPEARS SATURDAY WILL REMAIN DRY AREAWIDE...AND WILL KEEP POPS BELOW 15 PERCENT. DEWPOINTS WILL SLOWLY CLIMB...LIKELY REACHING THE UPR 50S. WEAK MID-LEVEL HEIGHT FALLS COMMENCE SATURDAY NIGHT AS MID-LEVEL SHORTWAVE TROUGH PROGRESSES EWD ACROSS THE GREAT LAKES. SHOULD SEE MOSTLY CLOUDY SKIES...WITH A CHANCE FOR A FEW SHOWERS DEVELOPING ACROSS NRN NY...AND PERHAPS FAR NRN VT TOWARD DAYBREAK SUNDAY. CLOUDS AND CONTINUED LIGHT SOUTH WINDS SAT NIGHT...COMBINED WITH WARMER AIR MASS WILL RESULT IN VERY MILD OVERNIGHT LOWS...RANGING FROM THE UPR 50S ACROSS THE CT RIVER VALLEY...TO 65-68F IN THE CHAMPLAIN AND ST. LAWRENCE VALLEYS. SUNDAY LOOKS LIKE THE BEST CHANCE FOR PRECIPITATION OVER THE NEXT SEVERAL DAYS. SHORTWAVE TROUGH PROVIDES MID-LEVEL UVV WHILE WEAK SURFACE-BASED INSTABILITY DEVELOPS WITH DAYTIME HEATING (SBCAPE VALUES OF 500-1000 J/KG). DEEP LAYER SHEAR IS NOT PARTICULARLY IMPRESSIVE...WITH SFC-6KM BULK SHEAR OF ONLY 20-25 KTS. COMBINED WITH ONLY WEAK INSTABILITY WITH ABUNDANT CLOUD COVER IN PLACE...NOT ANTICIPATING ANY SEVERE WEATHER ACTIVITY. THAT SAID...SHOWER AND THUNDERSTORM ACTIVITY WILL GRADUALLY BECOME MORE WIDESPREAD TOWARD AFTERNOON WITH PEAK HEATING. WHILE NOT A "WASHOUT"...THESE SHOWERS COULD BE LOCALLY HEAVY...AS PW VALUES APPROACH 2.00" IN BOTH THE NAM AND GFS. HAVE INCLUDED HEAVY DOWNPOUR MENTION IN THE HAZARDOUS WEATHER OUTLOOK AND IN THE FORECAST GRIDS. DEFINITELY WOULD BE GOOD TO HAVE AN INDOOR BACKUP PLAN FOR ANY PLANNED OUTINGS ON SUNDAY GIVING POTENTIAL FOR BRIEF HEAVY RAINFALL. HIGH TEMPERATURES WILL RANGE FROM THE UPR 70S TO LOWER 80S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 329 AM EDT FRIDAY...FAIRLY ACTIVE WEATHER EXPECTED FOR THE FIRST PART OF THE EXTENDED FORECAST PERIOD...SUNDAY NIGHT THROUGH TUESDAY NIGHT...WITH DRYING TAKING PLACE WEDNESDAY AND THURSDAY. COLD FRONT MOVES ACROSS THE AREA SUNDAY NIGHT AND THUS GOING FORECAST OF LIKELY SHOWERS AND THUNDERSTORMS LOOKS REAL GOOD. NOT MUCH AIR MASS CHANGE BEHIND THE FRONT ON MONDAY AND THUS SUFFICIENT INSTABILITY SHOULD DEVELOP MONDAY AFTERNOON FOR SOME SHOWERS AND STORMS TO DEVELOP. A BRIEF BREAK IN THE CONVECTION TAKES PLACE LATER MONDAY NIGHT AND TUESDAY MORNING BEFORE ANOTHER COLD FRONT MOVES INTO THE REGION TUESDAY AFTERNOON. THUS LOOKING AT ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH TUESDAY EVENING BEFORE DRIER WESTERLY FLOW ALOFT DEVELOPS OVER THE AREA WEDNESDAY AND THURSDAY. THERMAL PROFILE THROUGHOUT THE EXTENDED SUGGESTS DAYTIME HIGHS WILL BE AT OR A FEW DEGREES ABOVE SEASONAL NORMALS. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... THROUGH 12Z SATURDAY...VFR-MVFR CEILINGS WILL EXIST THROUGH ABOUT 16Z BEFORE ALL SITES BECOME VFR WITH VERY LITTLE IN THE WAY OF ANY CLOUDS FOR THE REMAINDER OF THE PERIOD. IFR-LIFR VISIBILITIES WILL EXIST AT KSLK THROUGH 14Z BEFORE BECOMING VFR LIKE ALL OTHER SITES FOR THE REMAINDER OF THE PERIOD. WINDS WILL GENERALLY BE LIGHT AND VARIABLE THROUGH THE PERIOD. OUTLOOK 12Z SATURDAY THROUGH TUESDAY... 12Z SAT ONWARD...MAINLY VFR...WITH MVFR/BRIEF IFR IN SCATTERED SHOWERS AND THUNDERSTORMS. && .MARINE... SOUTH WINDS WILL INCREASE SHARPLY ON LAKE CHAMPLAIN TOWARD DAYBREAK SATURDAY...AS THE PRESSURE GRADIENT INCREASES BETWEEN HIGH PRESSURE DEPARTING EAST OF NEW ENGLAND...AND A DEVELOPING LOW PRESSURE SYSTEM ACROSS THE CENTRAL GREAT LAKES. LOOKING AT WINDS 15-20 KNOTS WITH GUSTS TO 25 KNOTS AFTER 5 AM...WITH SUSTAINED SOUTH WINDS 15-25 KNOTS THROUGH MUCH OF THE DAYLIGHT HOURS ON SATURDAY. WAVES OVER THE BROAD PORTION OF LAKE CHAMPLAIN WILL BUILD TO 2 TO 3 FEET SATURDAY MORNING. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS SHORT TERM...BANACOS LONG TERM...EVENSON AVIATION...EVENSON/KGM MARINE...TEAM BTV
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1005 AM EDT FRI AUG 29 2014 .SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT WILL STALL OUT ACROSS CENTRAL NORTH CAROLINA TODAY. THE FRONT WILL GRADUALLY DISSIPATE OVER THE WEEKEND AS A LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 1000 AM FRIDAY... AS OF 13Z...LATEST OBSERVATIONS/ANALYSIS INDICATES THE SURFACE FRONT IS BISECTING THE FORECAST AREA. EXTENSIVE CLOUD COVER IS NOTED WITHIN THE NORTHEASTERLY FLOW ALONG AND NORTH OF THE FRONT...WITH MOSTLY CLEAR SKIES TO THE SOUTH. THERE STILL IS A GREAT LEVEL OF DISAGREEMENT AMONG THE MODELS WITH RESPECT TO THE EVOLUTION OF THIS CLOUD COVER...WITH THE NAM KEEPING THE NORTHERN HALF OF THE FORECAST AREA MOSTLY CLOUDY ALL DAY AND THE GFS AND RAP BREAKING OUT THE CLOUDS WITH MORE IN THE WAY OF EASTERLY/SOUTHEASTERLY FLOW LATER TODAY. BEING THERE ARE ALREADY INDICATIONS OF SOME BREAKS IN THE CLOUDS (VIA VISIBLE SATELLITE)...WILL FOLLOW CLOSER TO THE GFS AND RAP BUT WILL STILL SHOW SOME ENHANCED CLOUD COVER ACROSS NORTH. THIS WILL HAVE AN IMPACT ON HIGH TEMPS (ACROSS THE NORTH) TODAY...AS THE NAM SHOWS HIGHS ONLY REACHING THE UPPER 70/LOWER 80S...WITH UPPER 80S INDICATED BY THE OTHER MODELS. THEREFORE...WILL TREND THE HIGHS UPWARD ACROSS THE NORTH...BUT ONLY INTO THE MID 80S. WITH REGARDS TO PRECIP CHANCES...ISOLATED TO SCATTERED CONVECTION IS EXPECTED LATER THIS AFTERNOON...ESPECIALLY IN THE VICINITY OF THE FRONT. OVERNIGHT LOWS WILL GENERALLY RANGE FROM THE UPPER 60S ACROSS THE NORTH TO THE LOWER 70S FURTHER SOUTH. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 220 AM FRIDAY... CENTRAL NC WILL REMAIN UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE SAT/SAT NIGHT AS THE CENTER OF THE RIDGE CURRENTLY OVER THE SOUTHEAST STATES SHIFTS SLIGHTLY EAST TOWARD THE COAST. THE LINGERING FRONTAL ZONE OVER PORTIONS OF CENTRAL NC SHOULD WASH OUT DURING THE DAY AS A LIGHT S/SE RETURN FLOW DEVELOPS ACROSS THE REGION. FORECAST SOUNDINGS SUGGEST MARGINAL DESTABILIZATION WITH 500- 1500 J/KG OF MLCAPE SAT AFTERNOON. GIVEN A PROTOTYPICAL SUMMERTIME `RIDGE` PATTERN...EXPECT ABOVE NORMAL TEMPS...IN THE LOWER 90S. MARGINAL INSTABILITY AND SEASONABLE MOISTURE (PWAT VALUES OF 1.50- 1.75") WOULD SUPPORT ISOLD CONVECTION ON SATURDAY...THOUGH FORCING FOR ASCENT WILL BE LIMITED TO THE SEABREEZE AND DIFFERENTIAL HEATING...PRIMARILY ALONG THE HIGHER TERRAIN IN WESTERN NC...AND IT IS POSSIBLE THAT NO CONVECTION WILL DEVELOP IN CENTRAL NC. WITH THE ABOVE IN MIND...WILL INDICATE A SLIGHT CHANCE OF CONVECTION DURING THE AFT AND EARLY EVE HOURS IN THE WESTERN PIEDMONT AND SE COASTAL PLAIN. EXPECT NEAR NORMAL LOWS SAT NIGHT IN THE UPPER 60S TO LOWER 70S. -VINCENT && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 245 AM FRIDAY... A RIDGE WILL BUILD OVER THE SOUTHEASTERN STATES EARLY TO MID WEEK. THIS WILL EXTEND OUR CURRENT MORE SUMMER-LIKE PATTERN ACROSS NC WELL INTO WEDNESDAY. THE CORE OF THE UPPER RIDGE IS FORECAST TO BE OVER THE NC/SC COAST SUNDAY. THE APPROACHING UPPER TROUGH FROM THE OHIO VALLEY WILL BE DEFLECTED TO OUR NORTH AND WEAKEN SUNDAY NIGHT AND MONDAY. EVEN WITH THE HEAT AND HUMIDITY WITH THE SOUTHERLY RETURN FLOW... ONLY ISOLATED AFTERNOON THUNDERSTORMS ARE EXPECTED. THE BEST CHANCE IS FORECAST OVER AND NEAR THE BLUE RIDGE WHERE INSTABILITY... MOISTURE... AND LIFT WILL BE HIGHEST. HIGHS SHOULD REACH THE 88-93 RANGE. THE CORE OF THE UPPER RIDGE IS FORECAST TO SHIFT SOUTHWEST WITH TIME TO OVER THE GULF COAST STATES TUE-WED. THIS WILL ALLOW A WEAK PIEDMONT TROUGH AT THE SURFACE WHICH MAY AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS DURING THE AFTERNOON AND EVENING EARLY TO MID WEEK. OTHERWISE... SIMPLY WARM AND HUMID WITH PARTLY CLOUDY SKIES. LOWS 69-74. HIGHS 88-93 NW TO SANDHILLS. FOR MID TO LATE WEEK... ANY SURFACE FRONT IS EXPECTED TO BE WEAK AND PROVIDE LITTLE IF ANY COOLING OR DRYING. HOWEVER... IT MAY ACT AS A CONTINUED FOCUS FOR SCATTERED MAINLY AFTERNOON THUNDERSTORMS WED- FRI. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 730 AM FRIDAY... 24-HR TAF PERIOD: BELOW AVERAGE CONFIDENCE IN THE FORECAST THROUGH TONIGHT. THE NAM MODEL GUIDANCE BEST MATCHES THE LATEST OBS DATA... WHICH SUGGESTS THE NORTHERN TERMINALS (INT/GSO/RDU/RWI) WILL BE AFFECTED BY PERIODIC OR PERSISTENT IFR/MVFR CEILINGS THIS MORNING... WITH IMPROVEMENT TO MVFR DURING THE AFTERNOON. MVFR CEILINGS AND ISOLD CONVECTION WILL BE POSSIBLE THROUGH THE AFTERNOON AND EVENING HOURS. GIVEN THE LATEST TRENDS...A MORE PESSIMISTIC FORECAST MAY BE NECESSARY TONIGHT THROUGH SAT MORNING AT THE NORTHERN TERMINALS WHERE CONDITIONS MAY DETERIORATE TO IFR/LIFR OVERNIGHT BEFORE GRADUALLY IMPROVING TO VFR BY SAT AFTERNOON. LOOKING AHEAD: EXPECT A NEAR CLIMATOLOGICAL PATTERN THROUGH EARLY NEXT WEEK WITH A SLIGHT CHANCE OF AFTERNOON/EVENING CONVECTION AND A POTENTIAL FOR EARLY MORNING FOG/STRATUS. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...KRD SHORT TERM...VINCENT LONG TERM...PWB AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
954 AM EDT FRI AUG 29 2014 .SYNOPSIS... STRENGTHENING BERMUDA HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL BRING TYPICAL LATE SUMMER WEATHER CONDITIONS ACROSS THE AREA. WARMTH WILL CONTINUE ALONG WITH ISOLATED THUNDERSTORMS OVER THE LABOR DAY WEEKEND. A WEAK FRONT WILL STALL NEAR THE COAST NEXT WEEK INCREASING OUR RAIN CHANCES. && .NEAR TERM /THROUGH TONIGHT/... AS OF 952 AM FRIDAY...A COLD FRONT HAS REACHED A LINE FROM SOUTH OF CHARLOTTE TO GOLDSBORO AND EAST TO THE OUTER BANKS. THIS BOUNDARY IS DEPICTED WELL IN THE 925 MB THETA FIELD. THE 13 UTC RUC IS SHOWING THE EAST-WEST THETA GRADIENT DISSIPATING WITH THE AFTERNOON HEATING. MORNING SOUNDINGS AND THE BLENDED TOTAL PRECIPITABLE WATER IS SHOWING A MOISTURE GRADIENT FROM 1.6 INCHES TO THE NORTH TO 1.25 INCHES IN THE SOUTH. WITH THE BEST MOISTURE TO OUR NORTH. THE 12 UTC HRRR REFLECTIVITY FIELD IS DEPICTING SCATTERED AFTERNOON CONVECTION DEVELOPING JUST NORTH OF SOUTHEAST NORTH CAROLINA AND REMAINING DRY OVER THE FORECAST AREA. THUS AT THIS TIME WILL KEEP THE FORECAST RAIN FREE. FORECAST HIGHS WILL REMAIN THE SAME WITH HIGHS REACHING THE MIDDLE 90S MAINLY WEST OF LUMBERTON TO ANDREWS AND LOWER 90S CLOSER TO THE COAST. THERE WILL BE A FEW UPPER 80S ALONG THE IMMEDIATE BEACHES. CALM WINDS ARE EXPECTED OVERNIGHT AND WITH HIGH PRESSURE TO THE NORTH...WINDS WILL SHIFT TO AN ONSHORE FLOW. THIS WILL INCREASE THE LOW LEVEL MOISTURE AND IT IS EXPECTED TO INCREASE THE PROBABILITY OF FOG AND LOW STRATUS OVERNIGHT. LOWS OVERNIGHT ARE EXPECTED TO FALL TO AROUND 70. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...NOT A LOT OF CHANGES WARRANTED FOR THE SHORT TERM FORECAST AS HIGH PRESSURE WILL DOMINATE THROUGH ALL LEVELS OF THE ATMOSPHERE. GUIDANCE IS STILL SHOWING A RATHER WEAK SIGNAL FOR MOSTLY SEA BREEZE CONVECTION AND HAVE MAINTAINED THESE MINIMAL POPS IN THE FORECAST. PERHAPS A FEW MORE MID LEVEL CLOUDS WILL ADVANCE ON THE REGION SUNDAY AFTERNOON AND EVENING AS THE SYSTEM NOW LIGHTING UP THE CENTRAL PLAINS SLOWLY MAKES IT EAST. TEMPERATURE FORECAST/GUIDANCE WARRANTS ONLY TOKEN CHANGES AS UPPER 80S ALONG THE COASTAL AREAS AND LOWER 90S INLAND CONTINUE. 70S FOR MORNING LOWS. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...THE MID LEVEL PATTERN WILL CONTINUE TO BE DOMINATED BY RIDGING AS BASICALLY A ZONAL FLOW DEVELOPS. AN ELONGATED RIDGE WILL BUILD EAST TO WEST BY THE END OF THE PERIOD TRANSITIONING FROM A MORE AMPLIFIED PATTERN EARLY IN THE WEEK. AT THE SURFACE...NOTABLE FEATURES WILL BE HIGH PRESSURE ACROSS THE SOUTHEAST AND THE PIEDMONT TROUGH CLOSER TO OUR AREA. THERE WILL BE POPS ESSENTIALLY EVERY DAY WITH THE BEST CHANCES TUESDAY AND WEDNESDAY WHEN THE SURFACE FEATURES GET AN ASSIST FROM THE UPPER LEVELS. THE TIMING HOWEVER IS LOWER CONFIDENCE. WITH THE PERIOD MODULATED BY HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT...NO SURPRISE THAT TEMPERATURES BOTH MAX AND MINS WILL BE ABOVE NORMAL...BY JUST ABOUT A CATEGORY ACROSS THE BOARD. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...EXPECT VFR CONDITIONS THROUGH MUCH OF THE FORECAST PERIOD WITH WEST TO SOUTHWEST WINDS AROUND 5 KT THIS AM BECOMING S TO SE AT 5 TO 10 KT THIS AFTERNOON BEFORE DIMINISHING TONIGHT. WITH THE S TO SE FLOW...AN INCREASE IN LOW LEVEL MOISTURE IS EXPECTED THIS AFTERNOON INTO TONIGHT SUCH THAT FOG MAY DEVELOP OVERNIGHT. FOR NOW...TAFS HAVE MVFR FOG AND SCATTERED CLOUDS AT 500 FEET BUT THERE IS THE POTENTIAL FOR IFR FOG AFTER 06Z. EXTENDED OUTLOOK...MORNING FOG WITH MVFR/IFR CONDITIONS POSSIBLE SATURDAY. A SLIGHT CHANCE OF SHOWERS WITH MVFR FOR OUR NORTHERN TERMINALS SAT. INCREASING CHANCES FOR PRECIP SUNDAY THROUGH TUESDAY WITH MVFR CONDITIONS POSSIBLE. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 952 AM FRIDAY...CURRENTLY A WEST-SOUTHWEST FLOW OF 5 TO 10 KNOTS IS BLOWING OVER THE COASTAL WATERS WITH 2 TO 2.5 FT WAVES. THE BUOYS ARE PICKING UP A 1/3 FOOT SWELL FROM THE EAST SOUTHEAST THIS MORNING AND THE WAVE WATCH IS SHOWING THIS DECREASING WITH TIME. AS A FRONTAL BOUNDARY STALLING TO THE NORTH OF THE WATERS THE PRESSURE GRADIENT IS WEAK AND WIND SPEED ARE NOT EXPECTED TO INCREASE OVERNIGHT. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTH TO SOUTHEAST WINDS WILL CONTINUE FOR MOST OF THE PERIOD ON THE ORDER OF 10-15 KNOTS. THERE MAY BE A SLIGHT VEERING TO SOUTHWEST LATE SUNDAY INTO MONDAY MORNING AS A SYSTEM CREEPS IN FROM THE WEST BUT THIS WILL BE A VERY GRADUAL TRANSITION. SWAN SEAS SHOW A CONSISTENT 1-3 FEET THROUGHOUT THE PERIOD. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...LATE SUMMERTIME PATTERN WILL BE IN FULL FORCE ACROSS THE COASTAL WATERS. SOUTH TO SOUTHWEST WINDS OF 10-15 KNOTS WILL PREVAIL WITH A SLIGHT INCREASE DURING THE AFTERNOON HOURS. SIGNIFICANT SEAS...NOW VOID OF ANY SIGNIFICANT SWELL COMPONENT WILL BE 1-3 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...HAWKINS SHORT TERM...SHK LONG TERM...SHK AVIATION...RAN
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
954 AM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 952 AM CDT FRI AUG 29 2014 CURRENT RADAR SHOWING SOME WEAK SHOWERS OVER THE FAR SOUTHERN VALLEY DRIFTING OUT OF CWA. ALSO A STRONG STORM SOUTH OF MANITOBA MOVING EASTWARD ACROSS SOUTHERN MANITOBA AND NOT EXPECTED TO DROP INTO THE CONUS...HOWEVER WILL NEED TO WATCH LOW COUNTY IF IT HOLDS TOGETHER THAT LONG. MAIN ISSUE TODAY WILL BE CLOUDS. WHILE THE NAM SEEMS RATHER BULLISH WITH QPFS ASSOCIATED WITH ACTIVITY ACROSS EASTERN SD AND NORTH CENTRAL/EASTERN MN...POPS FOR THE SHARP SFC TROUGH MOVING ACROSS THE CWA TODAY SEEM REASONABLE. WILL TREND POPS TOWARD THE NAM SOLUTION FOR THIS AFTN. THERE ARE SOME SIGNS OF SKY BREAKING UP ACROSS EASTERN ND THIS MORNING TO PROVIDE SOME SOLAR FOR AFTN CONVECTION AS THE TROUGH MOVES THROUGH...HOWEVER THIS ACTIVITY WILL BE VERY DEPENDENT ON HOW MUCH SOLAR CAN GET THROUGH SO WILL LIMIT POPS TO LOW END OF CHANCE CATEGORY. ALSO HAVE REMOVED THUNDER AS PREDOMINANT PTYPE AND CHANGED OVER TO RAIN SHOWERS WITH ISOLD TSTMS. NO OTHER CHANGES EXPECTED THIS UPDATE. UPDATE ISSUED AT 655 AM CDT FRI AUG 29 2014 NO SIG UPDATES NEEDED AT THIS TIME. BANDS OF LIGHT RAIN ARE MOVING THROUGH THE BWP-FFM-PKD-BJI AREA IN THE DEFORMATION ZONE AT THE AHEAD OF THE LOW PRESSURE SYSTEM NOW IN SOUTHWEST MN. MEANWHILE A WINDSHIFT LINE IS APPARENT ON RADAR IMAGERY ALG A YWG-DVL-BIS LINE SHOWING THE APPROACHING LOW PRESSURE SYSTEM NOW EDGING INTO THE NORTHWEST CORNER OF THE FA. FOCUS FOR SHOWERS AND THUNDER SHOULD SHIFT TO THIS SYSTEM FOR LATER IN THE DAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY... WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS... EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MID AFTERNOON... SO AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500 J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK CONTAINS A /SEE TEXT/ OVER OUR AREA. TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE LATE EVENING OVER NORTH CENTRAL MN LAKES. SATURDAY SHOULD BE DRY AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY... OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3 OUTLOOKS. MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION. HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 415 AM CDT FRI AUG 29 2014 EXPECT -SHRA TO CONTINUE ACROSS THE FAR SRN VALLEY AND INTO LAKES COUNTY. OTHERWISE MOST AREAS WILL SEE MVFR/IFR CIGS AND PATCHY FOG THROUGH THE MORNING. AREAS MVFR CIGS LIKELY THROUGH MIDDAY AHEAD OF A SFC COLD FRONT FORECAST TO CROSS THE AREA. SCT SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT THROUGH THE AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...SPEICHER SHORT TERM...GUST LONG TERM...GUST/JR AVIATION...GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
822 AM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 813 AM CDT FRI AUG 29 2014 FRONTAL BOUNDARY CONTINUES TO MAKE ITS WAY THROUGH CENTRAL NORTH DAKOTA. MOST SHOWERS ARE REMAINING POST FRONTAL AS MAIN UPPER FORCING CONTINUES TO PUSH ITS WAY IN FROM EASTERN MONTANA. HAVE UPPED PRECIPITATION CHANCES SOME WITH CURRENT TRENDS. WILL HAVE TO KEEP AN EYE ON THE SOUTHERN JAMES RIVER VALLEY TOWARDS MID-DAY INTO EARLY AFTERNOON FOR SOME STORMS DEVELOPING AND POSSIBLY BECOMING STRONG AS MODELS CONTINUE TO SHOW INCREASING INSTABILITY THROUGH THE DAY THOUGH THE SHEAR COMPONENT REMAINS MODEST. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 642 AM CDT FRI AUG 29 2014 COLD FRONT MAKING ITS WAY INTO CENTRAL NORTH DAKOTA WITH VERY LIMITED CONVECTION ALONG IT. POST FRONTAL SHOWERS CONTINUE ACROSS THE WEST. CURRENT THINKING IS THE FRONTAL BOUNDARY WILL BECOME MORE ACTIVE AS IT ENTERS THE JAMES RIVER VALLEY LATER THIS MORNING/AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT FRI AUG 29 2014 THE 07 UTC SURFACE OBSERVATIONS PLACE THE COLD FRONT IN FAR NORTHWEST NORTH DAKOTA. THE COLD FRONT HAS BEEN SLOW MOVING EARLY THIS MORNING AND IS EXPECTED TO CONTINUE A SLOW PROGRESSION SOUTHEAST ACROSS THE AREA. LATEST RUNS OF THE HRRR AND WRF HAVE HAD A DIFFICULT TIME FORECASTING PRECIPITATION AHEAD AND BEHIND THE FRONT. AT THIS TIME EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH THE MORNING AND AFTERNOON AS THE FRONT PASSES. FOR NOW LEFT THE POSSIBILITY OF THUNDER IN THE FORECAST UP TO 12 UTC THIS MORNING THEN REMOVED THUNDER CHANCES FROM 12 TO 18 UTC. AFTER 18 UTC THERE SHOULD BE ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED THUNDER ALONG THE FRONT. LATEST 07 UTC SURFACE OBSERVATIONS SHOW WIND HAS WENT MOSTLY CALM OVER THE SOUTHEASTERN PORTION OF NORTH DAKOTA. WITH AMPLE LOW LEVEL MOISTURE FOG HAS STARTED TO DEVELOP ACROSS THE SOUTH CENTRAL AND SOUTHEAST. AT THIS TIME DO NOT BELIEVE ANY HEADLINE FOR FOG IS NEEDED AND HAVE OPTED WITH A SPECIAL WEATHER STATEMENT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 335 AM CDT FRI AUG 29 2014 BEGINNING SATURDAY A WELL DEFINED SHORTWAVE TROUGH WILL BE MOVING FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS. A SURFACE TROUGH AND FRONTAL BOUNDARY WILL MOVE THROUGH WESTERN NORTH DAKOTA BY SATURDAY NIGHT. MODELS HAVE BEEN CONSISTENT IN GENERATING A LINE OF CONVECTION WITH THE FRONT. MODEL CAPES ARE INITIALLY AROUND 2000 SATURDAY AFTERNOON WEST. AS THE SHORTWAVE AND SURFACE TROUGH MOVE EAST AN H850 SOUTHERLY INFLOW OF 50 KTS WILL SUPPLY ABUNDANT MOISTURE. THE PROGRESSIVE LINE OF STORMS LIKELY WILL PRODUCE AN INCH OF QPF ACROSS CENTRAL NORTH DAKOTA....WITH LOCALLY HIGHER AMOUNTS. CAPE AND SHEAR SUGGEST A PERIOD OF SEVERE STORMS (LARGE HAIL/WINDS) ARE POSSIBLE WESTERN NORTH DAKOTA LATE SATURDAY AFTERNOON/EVENING. KEPT THE HIGH POPS ACROSS WEST AND CENTRAL SECTION SATURDAY EVENING AND TRAILED THEM DOWN AFTER MIDNIGHT. FOLLOWING THIS A PERIOD (SUNDAY THROUGH TUESDAY) OF A RELATIVELY COOL AND WEAKLY CYCLONIC FLOW ALOFT. THIS SHOULD SUPPORT WIDELY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. WEDNESDAY WILL BECOME A TRANSITION DAY WITH DRY WEATHER AS THE NEXT SHORTWAVE IS MOVING INTO THE NORTHWEST US WITH A DOWNSTREAM RIDGE OVER THE NORTHERN PLAINS. THURSDAY WILL PICK UP A CHANCE FOR THUNDERSTORMS AGAIN WITH THIS NEXT SHORTWAVE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 642 AM CDT FRI AUG 29 2014 A COLD FRONT HAS PASSED KISN...KMOT...AND KDIK THIS MORNING AND WILL CONTINUE SOUTHEAST THROUGH THE MORNING. THIS WILL SHIFT WINDS AT SITES KBIS AND KJMS NORTHWESTERLY. THIS WILL ALSO PROVIDE A CHANCE OF SHOWERS AT KMOT...KDIK...KBIS...AND KJMS TODAY. ISOLATED THUNDERSTORMS WILL ALSO BE POSSIBLE...HOWEVER HAVE LEFT TSRA OUT OF THE TAFS FOR NOW. ANTICIPATE FOG TO DISSIPATE AT SITES KBIS AND KJMS OVER THE NEXT FEW HOURS. OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE 12Z TAF CYCLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JJS SHORT TERM...MM LONG TERM...WAA AVIATION...MM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
657 AM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 655 AM CDT FRI AUG 29 2014 NO SIG UPDATES NEEDED AT THIS TIME. BANDS OF LIGHT RAIN ARE MOVING THROUGH THE BWP-FFM-PKD-BJI AREA IN THE DEFORMATION ZONE AT THE AHEAD OF THE LOW PRESSURE SYSTEM NOW IN SOUTHWEST MN. MEANWHILE A WINDSHIFT LINE IS APPARENT ON RADAR IMAGERY ALG A YWG-DVL-BIS LINE SHOWING THE APPROACHING LOW PRESSURE SYSTEM NOW EDGING INTO THE NORTHWEST CORNER OF THE FA. FOCUS FOR SHOWERS AND THUNDER SHOULD SHIFT TO THIS SYSTEM FOR LATER IN THE DAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY... WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS... EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MIDAFTERNOON... SO AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500 J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK CONTAINS A /SEE TEXT/ OVER OUR AREA. TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE LATE EVENING OVER NORTHCENTRAL MN LAKES. SATURDAY SHOULD BE DRY AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY... OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3 OUTLOOKS. MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION. HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 415 AM CDT FRI AUG 29 2014 EXPECT -SHRA TO CONTINUE ACROSS THE FAR SRN VALLEY AND INTO LAKES COUNTY. OTHERWISE MOST AREAS WILL SEE MVFR/IFR CIGS AND PATCHY FOG THROUGH THE MORNING. AREAS MVFR CIGS LIKELY THROUGH MIDDAY AHEAD OF A SFC COLD FRONT FORECAST TO CROSS THE AREA. SCT SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT THROUGH THE AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...GUST SHORT TERM...GUST LONG TERM...GUST/JR AVIATION...GUST
AREA FORECAST DISCUSSION
NWS BISMARCK ND
648 AM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 642 AM CDT FRI AUG 29 2014 COLD FRONT MAKING ITS WAY INTO CENTRAL NORTH DAKOTA WITH VERY LIMITED CONVECTION ALONG IT. POST FRONTAL SHOWERS CONTINUE ACROSS THE WEST. CURRENT THINKING IS THE FRONTAL BOUNDARY WILL BECOME MORE ACTIVE AS IT ENTERS THE JAMES RIVER VALLEY LATER THIS MORNING/AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 335 AM CDT FRI AUG 29 2014 THE 07 UTC SURFACE OBSERVATIONS PLACE THE COLD FRONT IN FAR NORTHWEST NORTH DAKOTA. THE COLD FRONT HAS BEEN SLOW MOVING EARLY THIS MORNING AND IS EXPECTED TO CONTINUE A SLOW PROGRESSION SOUTHEAST ACROSS THE AREA. LATEST RUNS OF THE HRRR AND WRF HAVE HAD A DIFFICULT TIME FORECASTING PRECIPITATION AHEAD AND BEHIND THE FRONT. AT THIS TIME EXPECT ISOLATED TO SCATTERED SHOWERS THROUGH THE MORNING AND AFTERNOON AS THE FRONT PASSES. FOR NOW LEFT THE POSSIBILITY OF THUNDER IN THE FORECAST UP TO 12 UTC THIS MORNING THEN REMOVED THUNDER CHANCES FROM 12 TO 18 UTC. AFTER 18 UTC THERE SHOULD BE ENOUGH INSTABILITY FOR ISOLATED TO SCATTERED THUNDER ALONG THE FRONT. LATEST 07 UTC SURFACE OBSERVATIONS SHOW WIND HAS WENT MOSTLY CALM OVER THE SOUTHEASTERN PORTION OF NORTH DAKOTA. WITH AMPLE LOW LEVEL MOISTURE FOG HAS STARTED TO DEVELOP ACROSS THE SOUTH CENTRAL AND SOUTHEAST. AT THIS TIME DO NOT BELIEVE ANY HEADLINE FOR FOG IS NEEDED AND HAVE OPTED WITH A SPECIAL WEATHER STATEMENT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 335 AM CDT FRI AUG 29 2014 BEGINNING SATURDAY A WELL DEFINED SHORTWAVE TROUGH WILL BE MOVING FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS. A SURFACE TROUGH AND FRONTAL BOUNDARY WILL MOVE THROUGH WESTERN NORTH DAKOTA BY SATURDAY NIGHT. MODELS HAVE BEEN CONSISTENT IN GENERATING A LINE OF CONVECTION WITH THE FRONT. MODEL CAPES ARE INITIALLY AROUND 2000 SATURDAY AFTERNOON WEST. AS THE SHORTWAVE AND SURFACE TROUGH MOVE EAST AN H850 SOUTHERLY INFLOW OF 50 KTS WILL SUPPLY ABUNDANT MOISTURE. THE PROGRESSIVE LINE OF STORMS LIKELY WILL PRODUCE AN INCH OF QPF ACROSS CENTRAL NORTH DAKOTA....WITH LOCALLY HIGHER AMOUNTS. CAPE AND SHEAR SUGGEST A PERIOD OF SEVERE STORMS (LARGE HAIL/WINDS) ARE POSSIBLE WESTERN NORTH DAKOTA LATE SATURDAY AFTERNOON/EVENING. KEPT THE HIGH POPS ACROSS WEST AND CENTRAL SECTION SATURDAY EVENING AND TRAILED THEM DOWN AFTER MIDNIGHT. FOLLOWING THIS A PERIOD (SUNDAY THROUGH TUESDAY) OF A RELATIVELY COOL AND WEAKLY CYCLONIC FLOW ALOFT. THIS SHOULD SUPPORT WIDELY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS. WEDNESDAY WILL BECOME A TRANSITION DAY WITH DRY WEATHER AS THE NEXT SHORTWAVE IS MOVING INTO THE NORTHWEST US WITH A DOWNSTREAM RIDGE OVER THE NORTHERN PLAINS. THURSDAY WILL PICK UP A CHANCE FOR THUNDERSTORMS AGAIN WITH THIS NEXT SHORTWAVE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 642 AM CDT FRI AUG 29 2014 A COLD FRONT HAS PASSED KISN...KMOT...AND KDIK THIS MORNING AND WILL CONTINUE SOUTHEAST THROUGH THE MORNING. THIS WILL SHIFT WINDS AT SITES KBIS AND KJMS NORTHWESTERLY. THIS WILL ALSO PROVIDE A CHANCE OF SHOWERS AT KMOT...KDIK...KBIS...AND KJMS TODAY. ISOLATED THUNDERSTORMS WILL ALSO BE POSSIBLE...HOWEVER HAVE LEFT TSRA OUT OF THE TAFS FOR NOW. ANTICIPATE FOG TO DISSIPATE AT SITES KBIS AND KJMS OVER THE NEXT FEW HOURS. OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE 12Z TAF CYCLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...MM LONG TERM...WAA AVIATION...MM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1053 AM EDT FRI AUG 29 2014 .SYNOPSIS... A COLD FRONT WILL LINGER OVER NORTH CAROLINA TODAY BEFORE DISSIPATING TONIGHT. A BERMUDA HIGH WILL SET UP FOR THE WEEKEND AND EARLY NEXT WEEK...BRINGING TYPICAL SUMMERTIME HEAT AND HUMIDITY...WITH SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS EACH DAY. && .NEAR TERM /THROUGH TONIGHT/... 1015 AM UPDATE...STRATUS DECK HAS EXPANDED INTO THE NW NC PIEDMONT WITHIN WEDGELIKE AIR MASS NORTH OF PESKY BACK DOOR FRONT. THE DECK/S PROGRESS HAS SLOWED EVIDENTLY DUE TO MIXING ALONG THE EDGES AS TEMPERATURES RISE. NONETHELESS IT STANDS A GOOD CHANCE OF LASTING INTO MIDDAY DUE TO UPGLIDE ATOP THE COOLER LAYER. BIGGEST CHANGE TO THE FCST AT THIS UPDATE WAS TO REFLECT THE MCLDY SKIES IN THIS AREA. AS FOR POPS...MOST OF THE GUIDANCE DEVELOPS DEEP CONVECTION ONLY OVER THE RIDGETOPS TODAY...DESPITE THE ELEVATED INSTABILITY SEEN ABOVE THE STRATUS LAYER. THIS EVIDENCED BY RAP SOUNDINGS AS WELL AS THE TOWERS SEEN EMBEDDED IN THE DECK ON SATELLITE OVER THE TRIAD REGION. MAINTAINED SIMILAR POP TRENDS TO THOSE FROM EARLIER PACKAGE BUT FOCUSED THEM MORE OVER THE NW NC PIEDMONT THIS MRNG FOR THE LATTER REASON. NEWEST GUID ALSO ALLOWS SOME ELEVATED ACTIVITY TO FIRE OVERNIGHT TONIGHT...BUT WITH THE WEDGE BEGINNING TO BREAK DOWN BY THEN I WOULD LIKE TO SEE MORE OF A CONSENSUS BEFORE ADDING ANY POPS FOR IT. PREVIOUS DISCUSSION... AS OF 330 AM EDT FRIDAY...UPPER LEVEL RIDGE CENTERED OVER THE SOUTHEAST WILL CONTINUE TO DOMINATE THE PATTERN THROUGH THE NEAR TERM FORECAST PERIOD. MEANWHILE...DEEPENING SHORT WAVE TROF ACROSS THE CENTRAL/SOUTHERN PLAINS CONTINUES TO PROMOTE PRESSURE FALLS AT THE SURFACE LEADING TO STRONG MOISTURE ADVECTION ACROSS THE LOWER MISSISSIPPI RIVER VALLEY. ALSO AT THE SURFACE...QUASI STATIONARY BACK DOOR FRONT REMAINS DRAPED IN AN EAST/WEST ORIENTATION ACROSS NORTH CAROLINA...WEST INTO TENNESSEE. A 1020MB SURFACE HIGH ACROSS THE NORTHEAST CONTINUES SLIDE EAST AND WEDGE DOWN THE LEE SIDE OF THE CENTRAL AND SOUTHERN APPS. LATEST SATELLITE DIFFERENCE PRODUCT IMAGERY AND SURFACE OBS ANALYSIS INDICATE AREA OF STRATUS DEVELOPMENT TIED TO A ZONE OF SURFACE CONVERGENCE ALONG THE ABOVE MENTIONED BACK DOOR FRONT AND INTRUDING SURFACE RIDGE. GUIDANCE HAS HANDLED THIS SITUATION FAIRLY WELL AND ALSO INDICATES FURTHER EXPANSION OF LOW STRATUS INTO THE CENTRAL/SOUTHERN PIEDMONT REGION THROUGH LATE MORNING. MEANWHILE...CALMING WINDS AND VERY MOIST DECOUPLING PBL ACROSS THE HIGH TERRAIN WILL LEAD TO DEVELOPMENT OF PATCHY FOG THIS MORNING WITH VISIBILITIES DROPPING TO LESS THAN 2 MILES...MAINLY IN AND AROUND THE MOUNTAIN VALLEYS. EXPECTING ABOVE MENTIONED HIGH PRESSURE BOUNDARY AND OLD BACK DOOR FRONTAL BOUNDARY TO BE THE PRIMARY FOCUS OF CONCERN THROUGH THE NEAR TERM PERIOD. LOCATIONS SOUTH OF THIS AXIS SUCH AS THE UPSTATE OF SOUTH CAROLINA AND NORTHEAST GEORGIA WILL EXPERIENCE A FAIRLY NICE FRIDAY WITH MOSTLY SUNNY SKIES AND DRY CONDITIONS PREVAILING AMONGST WEAK/INCREASING SOUTHERLY FLOW AND UPPER LEVEL SUBSIDENCE. AS FOR LOCATIONS TO THE NORTH...SURFACE CONVERGENCE...BETTER MOISTURE PROFILES...AND WEAKER CAPPING WILL WARRANT MENTION OF ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS. FORECAST SOUNDINGS DO INDICATE MODEST INSTABILITY ACROSS THE SOUTHERN TIER OF WESTERN NORTH CAROLINA WERE BETTER DIFFERENTIAL HEATING IS EXPECTED. HOWEVER THIS THREAT SEEMS TO BE TIED TO A RATHER SMALL AREA WERE ENOUGH INSTABILITY WILL EXIST ADJACENT TO THE SURFACE CONVERGENCE AXIS PROVIDING NEEDED FORCING. ALL SAID...THE HWO WILL MENTION LOW END THREAT FOR DIURNAL HEATING AIDED ISOLATED THUNDERSTORMS ALONG THE I40 CORRIDOR WITH DAMAGING WINDS AND FREQUENT LIGHTNING BEING THE PRIMARY THREATS. CONVECTION WILL TAPER INTO THE EARLY EVENING HOURS AS HEATING SUBSIDES WITH ALL POPS BEING REMOVED BY MIDNIGHT. TEMPERATURES ON FRIDAY WILL REACH NORMAL LEVELS ACROSS MUCH OF THE UPSTATE AND NORTHEAST GEORGIA WITH HIGHS BEING SLIGHTLY COOLER ACROSS WESTERN NORTH CAROLINA DUE TO SKY COVER AND POSSIBLE CONVECTION. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 340 AM FRIDAY...UPPER ANTICYCLONE OVER THE SERN CONUS SLIDES TO COAST SAT...THEN REMAINS THERE THRU THE PERIOD. THE ASSOCIATED RIDGING REMAINS IN PLACE...BUT SLOWLY WEAKENS OR IS SUPPRESSED AS NRN AND SRN STREAM SHORT WAVES MOVE EAST OVER AND INTO THE RIDGE. AT THE SFC...SLY FLOW DEVELOPS AS A WEAK COLD FRONT MOVES TOWARD THE AREA. THE FRONT WASHES OUT SUN...BUT SLY FLOW REMAINS AS A LEE TROF DEVELOPS. WITH THE MOISTURE INCREASE...INSTABILITY DEVELOPS ACROSS THE MTNS AND UPPER SAV RIVER VALLEY...LEADING TO SCT DIURNAL CONVECTION. COULD SEE ISOLATED CONVECTION ACROSS THE FOOTHILLS AND WRN UPSTATE IN THE TRANSITION ZONE BETWEEN AN UNSTABLE ATMOS AND A CAPPED ATMOS OVER THE NC PIEDMONT AND ERN UPSTATE. TEMPS WILL BE NEAR TO A LITTLE ABOVE NORMAL. MODERATE INSTABILITY DEVELOPS ACROSS THE AREA SUN AS LOW LEVEL MOISTURE CONTINUES TO INCREASE. THE WEAKENING BOUNDARY AND LEE TROF SHUD PROVIDE LOW LEVEL CONVERGENCE WHILE THE SHORT WAVES AND UPPER DIVERGENCE FROM THE RIGHT ENTRANCE REGION OF A JET STREAK PROVIDE SYNOPTIC SCALE FORCING. THE RESULT WILL BE NUMEROUS COVERAGE OF DIURNAL CONVECTION ACROSS THE MTNS AND SOLID SCT COVERAGE ALONG AND NORTH OF THE I-85 CORRIDOR...TAPERING OFF SLIGHTLY TO THE SOUTH. PW VALUES INCREASE TO AROUND 2 INCHES SUNDAY AND COULD LEAD TO STORMS WITH HEAVY RAINFALL...AND POSSIBLY ISOLATED EXCESSIVE RAINFALL. HIGHS SUN WILL BE NEAR NORMAL WITH LOWS SUN NITE A LITTLE ABOVE NORMAL. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM FRIDAY...THE UPPER ANTICYCLONE REMAINS SUPPRESSED OVER THE SERN CONUS AT THE START OF THE PERIOD...THEN SLOWLY RETROGRADES ACROSS THE GULF COAST STATES INTO THE MID SOUTH WITH RIDGING BUILDING OVER THE MS RIVER VALLEY. NEARLY ZONAL FLOW ON TOP OF THE ANTICYCLONE WILL BRING WEAK SHORT WAVES NEAR OR ACROSS THE AREA. WEAK SLY LOW LEVEL FLOW AND A SFC LEE TROF REMAIN ACROSS THE AREA THRU THE PERIOD. A COLD FRONT DOES DROP SOUTH TOWARD THE AREA WED... BUT DISSIPATES BEFORE REACHING THE AREA. THIS WILL LEAD TO GENERALLY SCT DIURNAL CONVECTION EACH DAY...WITH A RELATIVELY LULL ON TUE OF LOW END SCT MTNS AND FOOTHILLS AND ISOLATED ELSEWHERE. HIGHS WILL BE NEAR TO A LITTLE ABOVE NORMAL EACH DAY...WITH LOWS A LITTLE ABOVE NORMAL THRU THE PERIOD. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... AT KCLT...STATIONARY FRONTAL BOUNDARY WILL REMAIN IN THE AREA THROUGH THE DAY BEFORE LIFTING NORTH OF THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. MVFR STRATUS DECK WILL LINGER IN THE AREA AS HIGH PRESSURE WEDGES SOUTHWARD AND INTERACTS WITH ABOVE MENTIONED BOUNDARY...BUT MIXING IS EXPECTED TO PREVENT IT FROM FORMING A CIG AT THE FIELD EXCEPT MAYBE BRIEFLY. NORTHEAST WINDS WILL INCREASE INTO THE 5-7KTS RANGE THROUGH MORNING BEFORE VEERING SOUTHERLY AS THE BOUNDARY PUSHES NORTH LATE IN THE DAY OR EARLY EVENING. SOME LOW END GUSTS ARE LIKELY AT TIMES THIS MORNING. CARRIED LIGHT SOUTHEASTERLY WINDS UNDER LOW VFR CU FROM 00Z THROUGH THE REMAINDER OF THE PERIOD. ELSEWHERE...EXPECTING VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD AT ALL SITES WITH THE POSSIBLE EXCEPTION OF FOG RESTRICITONS AT KAVL SATURDAY MORNING. INITIALIZED ALL TAFS VFR WITH AN INTRODUCTION OF MVFR LEVEL STRATUS AROUND 14Z AT KHKY AS MOISTURE CONDENSES ALONG CONVERGENCE AXIS BETWEEN INTRUDING HIGH PRESSURE AND OLD STATIONARY FRONT. VFR WILL RETURN TO ALL SITES BY MIDDAY WITH SKIES SCT OUT AND WINDS SHIFTING SOUTHERLY AT THE SC SITES AND KAVL AS THE ABOVE MENTIONED FRONT MIGRATES NORTH WHILE KHKY REMAINS NORTHERLY THROUGH THE END OF THE PERIOD. OUTLOOK...MOISTURE RETURN THROUGH THE WEEKEND WILL LEAD TO INCREASING CHANCES FOR ISOLATED/SCATTERED DIURNAL SHRA AND TSRA WITH THE GREATEST PROBABILITIES RESIDING ALONG THE HIGH TERRAIN. IN ADDITION...MORNING FOG/STRATUS WILL BE POSSIBLE WITH THE MOUNTAINS ONCE AGAIN HAVING THE GREATEST CHANCES AT RESTRICTIONS. CONFIDENCE TABLE... 15-21Z 21-03Z 03-09Z 09-15Z KCLT MED 78% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% MED 65% MED 65% KHKY MED 61% HIGH 100% MED 70% MED 62% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...WIMBERLEY NEAR TERM...CDG/WIMBERLEY SHORT TERM...RWH LONG TERM...RWH AVIATION...CDG/WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1032 AM EDT FRI AUG 29 2014 .SYNOPSIS... A COLD FRONT WILL DROP DOWN INTO NORTH CAROLINA FROM THE NORTH THIS MORNING...LINGERING OVER THE REGION BRIEFLY BEFORE DISSIPATING TONIGHT. A BERMUDA HIGH WILL SET UP FOR THE WEEKEND AND EARLY NEXT WEEK...BRINGING TYPICAL SUMMERTIME HEAT AND HUMIDITY...WITH SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS EACH DAY. && .NEAR TERM /THROUGH TONIGHT/... 1015 AM UPDATE...STRATUS DECK HAS EXPANDED INTO THE NW NC PIEDMONT WITHIN WEDGELIKE AIR MASS NORTH OF PESKY BACK DOOR FRONT. THE DECK/S PROGRESS HAS SLOWED EVIDENTLY DUE TO MIXING ALONG THE EDGES AS TEMPERATURES RISE. NONETHELESS IT STANDS A GOOD CHANCE OF LASTING INTO MIDDAY DUE TO UPGLIDE ATOP THE COOLER LAYER. BIGGEST CHANGE TO THE FCST AT THIS UPDATE WAS TO REFLECT THE MCLDY SKIES IN THIS AREA. AS FOR POPS...MOST OF THE GUIDANCE DEVELOPS DEEP CONVECTION ONLY OVER THE RIDGETOPS TODAY...DESPITE THE ELEVATED INSTABILITY SEEN ABOVE THE STRATUS LAYER. THIS EVIDENCED BY RAP SOUNDINGS AS WELL AS THE TOWERS SEEN EMBEDDED IN THE DECK ON SATELLITE OVER THE TRIAD REGION. MAINTAINED SIMILAR POP TRENDS TO THOSE FROM EARLIER PACKAGE BUT FOCUSED THEM MORE OVER THE NW NC PIEDMONT THIS MRNG FOR THE LATTER REASON. NEWEST GUID ALSO ALLOWS SOME ELEVATED ACTIVITY TO FIRE OVERNIGHT TONIGHT...BUT WITH THE WEDGE BEGINNING TO BREAK DOWN BY THEN I WOULD LIKE TO SEE MORE OF A CONSENSUS BEFORE ADDING ANY POPS FOR IT. PREVIOUS DISCUSSION... AS OF 330 AM EDT FRIDAY...UPPER LEVEL RIDGE CENTERED OVER THE SOUTHEAST WILL CONTINUE TO DOMINATE THE PATTERN THROUGH THE NEAR TERM FORECAST PERIOD. MEANWHILE...DEEPENING SHORT WAVE TROF ACROSS THE CENTRAL/SOUTHERN PLAINS CONTINUES TO PROMOTE PRESSURE FALLS AT THE SURFACE LEADING TO STRONG MOISTURE ADVECTION ACROSS THE LOWER MISSISSIPPI RIVER VALLEY. ALSO AT THE SURFACE...QUASI STATIONARY BACK DOOR FRONT REMAINS DRAPED IN AN EAST/WEST ORIENTATION ACROSS NORTH CAROLINA...WEST INTO TENNESSEE. A 1020MB SURFACE HIGH ACROSS THE NORTHEAST CONTINUES SLIDE EAST AND WEDGE DOWN THE LEE SIDE OF THE CENTRAL AND SOUTHERN APPS. LATEST SATELLITE DIFFERENCE PRODUCT IMAGERY AND SURFACE OBS ANALYSIS INDICATE AREA OF STRATUS DEVELOPMENT TIED TO A ZONE OF SURFACE CONVERGENCE ALONG THE ABOVE MENTIONED BACK DOOR FRONT AND INTRUDING SURFACE RIDGE. GUIDANCE HAS HANDLED THIS SITUATION FAIRLY WELL AND ALSO INDICATES FURTHER EXPANSION OF LOW STRATUS INTO THE CENTRAL/SOUTHERN PIEDMONT REGION THROUGH LATE MORNING. MEANWHILE...CALMING WINDS AND VERY MOIST DECOUPLING PBL ACROSS THE HIGH TERRAIN WILL LEAD TO DEVELOPMENT OF PATCHY FOG THIS MORNING WITH VISIBILITIES DROPPING TO LESS THAN 2 MILES...MAINLY IN AND AROUND THE MOUNTAIN VALLEYS. EXPECTING ABOVE MENTIONED HIGH PRESSURE BOUNDARY AND OLD BACK DOOR FRONTAL BOUNDARY TO BE THE PRIMARY FOCUS OF CONCERN THROUGH THE NEAR TERM PERIOD. LOCATIONS SOUTH OF THIS AXIS SUCH AS THE UPSTATE OF SOUTH CAROLINA AND NORTHEAST GEORGIA WILL EXPERIENCE A FAIRLY NICE FRIDAY WITH MOSTLY SUNNY SKIES AND DRY CONDITIONS PREVAILING AMONGST WEAK/INCREASING SOUTHERLY FLOW AND UPPER LEVEL SUBSIDENCE. AS FOR LOCATIONS TO THE NORTH...SURFACE CONVERGENCE...BETTER MOISTURE PROFILES...AND WEAKER CAPPING WILL WARRANT MENTION OF ISOLATED/SCATTERED SHOWERS AND THUNDERSTORMS. FORECAST SOUNDINGS DO INDICATE MODEST INSTABILITY ACROSS THE SOUTHERN TIER OF WESTERN NORTH CAROLINA WERE BETTER DIFFERENTIAL HEATING IS EXPECTED. HOWEVER THIS THREAT SEEMS TO BE TIED TO A RATHER SMALL AREA WERE ENOUGH INSTABILITY WILL EXIST ADJACENT TO THE SURFACE CONVERGENCE AXIS PROVIDING NEEDED FORCING. ALL SAID...THE HWO WILL MENTION LOW END THREAT FOR DIURNAL HEATING AIDED ISOLATED THUNDERSTORMS ALONG THE I40 CORRIDOR WITH DAMAGING WINDS AND FREQUENT LIGHTNING BEING THE PRIMARY THREATS. CONVECTION WILL TAPER INTO THE EARLY EVENING HOURS AS HEATING SUBSIDES WITH ALL POPS BEING REMOVED BY MIDNIGHT. TEMPERATURES ON FRIDAY WILL REACH NORMAL LEVELS ACROSS MUCH OF THE UPSTATE AND NORTHEAST GEORGIA WITH HIGHS BEING SLIGHTLY COOLER ACROSS WESTERN NORTH CAROLINA DUE TO SKY COVER AND POSSIBLE CONVECTION. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 340 AM FRIDAY...UPPER ANTICYCLONE OVER THE SERN CONUS SLIDES TO COAST SAT...THEN REMAINS THERE THRU THE PERIOD. THE ASSOCIATED RIDGING REMAINS IN PLACE...BUT SLOWLY WEAKENS OR IS SUPPRESSED AS NRN AND SRN STREAM SHORT WAVES MOVE EAST OVER AND INTO THE RIDGE. AT THE SFC...SLY FLOW DEVELOPS AS A WEAK COLD FRONT MOVES TOWARD THE AREA. THE FRONT WASHES OUT SUN...BUT SLY FLOW REMAINS AS A LEE TROF DEVELOPS. WITH THE MOISTURE INCREASE...INSTABILITY DEVELOPS ACROSS THE MTNS AND UPPER SAV RIVER VALLEY...LEADING TO SCT DIURNAL CONVECTION. COULD SEE ISOLATED CONVECTION ACROSS THE FOOTHILLS AND WRN UPSTATE IN THE TRANSITION ZONE BETWEEN AN UNSTABLE ATMOS AND A CAPPED ATMOS OVER THE NC PIEDMONT AND ERN UPSTATE. TEMPS WILL BE NEAR TO A LITTLE ABOVE NORMAL. MODERATE INSTABILITY DEVELOPS ACROSS THE AREA SUN AS LOW LEVEL MOISTURE CONTINUES TO INCREASE. THE WEAKENING BOUNDARY AND LEE TROF SHUD PROVIDE LOW LEVEL CONVERGENCE WHILE THE SHORT WAVES AND UPPER DIVERGENCE FROM THE RIGHT ENTRANCE REGION OF A JET STREAK PROVIDE SYNOPTIC SCALE FORCING. THE RESULT WILL BE NUMEROUS COVERAGE OF DIURNAL CONVECTION ACROSS THE MTNS AND SOLID SCT COVERAGE ALONG AND NORTH OF THE I-85 CORRIDOR...TAPERING OFF SLIGHTLY TO THE SOUTH. PW VALUES INCREASE TO AROUND 2 INCHES SUNDAY AND COULD LEAD TO STORMS WITH HEAVY RAINFALL...AND POSSIBLY ISOLATED EXCESSIVE RAINFALL. HIGHS SUN WILL BE NEAR NORMAL WITH LOWS SUN NITE A LITTLE ABOVE NORMAL. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 355 AM FRIDAY...THE UPPER ANTICYCLONE REMAINS SUPPRESSED OVER THE SERN CONUS AT THE START OF THE PERIOD...THEN SLOWLY RETROGRADES ACROSS THE GULF COAST STATES INTO THE MID SOUTH WITH RIDGING BUILDING OVER THE MS RIVER VALLEY. NEARLY ZONAL FLOW ON TOP OF THE ANTICYCLONE WILL BRING WEAK SHORT WAVES NEAR OR ACROSS THE AREA. WEAK SLY LOW LEVEL FLOW AND A SFC LEE TROF REMAIN ACROSS THE AREA THRU THE PERIOD. A COLD FRONT DOES DROP SOUTH TOWARD THE AREA WED... BUT DISSIPATES BEFORE REACHING THE AREA. THIS WILL LEAD TO GENERALLY SCT DIURNAL CONVECTION EACH DAY...WITH A RELATIVELY LULL ON TUE OF LOW END SCT MTNS AND FOOTHILLS AND ISOLATED ELSEWHERE. HIGHS WILL BE NEAR TO A LITTLE ABOVE NORMAL EACH DAY...WITH LOWS A LITTLE ABOVE NORMAL THRU THE PERIOD. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. STATIONARY FRONTAL BOUNDARY WILL REMAIN IN THE AREA THROUGH THE DAY BEFORE LIFTING NORTH OF THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. STILL EXPECTING SKY COVER TO INCREASE ACROSS THE NC PIEDMONT LATER THIS MORNING AS HIGH PRESSURE WEDGES SOUTHWARD AND INTERACTS WITH ABOVE MENTIONED BOUNDARY. THUS...LOW STRATUS CURRENTLY TO THE NORTH IS EXPECTED TO EXPAND SOUTHWARD AND LOWER OVER THE AIRFIELD AROUND THE 14Z TIMEFRAME WITH NO CIG RESTRICIONS FORECAST AT THIS TIME AS TAF ONLY HIGHLIGHTS SCT025. THIS LOW SCT STRATUS WILL LINGER THROUGH MUCH OF THE MORNING...EVENTUALLY LIFTING BY APPROX 18Z. NORTHEAST WINDS WILL INCREASE INTO THE 5-7KTS RANGE THROUGH MORNING BEFORE VEERING SOUTHERLY AS THE BOUNDARY PUSHES NORTH LATE IN THE DAY OR EARLY EVENING. CARRIED LIGHT SOUTHEASTERLY WINDS UNDER LOW VFR CU FROM 00Z THROUGH THE REMAINDER OF THE PERIOD. ELSEWHERE...EXPECTING VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD AT ALL SITES WITH THE POSSIBLE EXCEPTION OF FOG RESTRICITONS AT KAVL SATURDAY MORNING. INITIALIZED ALL TAFS VFR WITH AN INTRODUCTION OF MVFR LEVEL STRATUS AROUND 14Z AT KHKY AS MOISTURE CONDENSES ALONG CONVERGENCE AXIS BETWEEN INTRUDING HIGH PRESSURE AND OLD STATIONARY FRONT. VFR WILL RETURN TO ALL SITES BY MIDDAY WITH SKIES SCT OUT AND WINDS SHIFTING SOUTHERLY AT THE SC SITES AND KAVL AS THE ABOVE MENTIONED FRONT MIGRATES NORTH WHILE KHKY REMAINS NORTHERLY THROUGH THE END OF THE PERIOD. OUTLOOK...MOISTURE RETURN THROUGH THE WEEKEND WILL LEAD TO INCREASING CHANCES FOR ISOLATED/SCATTERED DIURNAL SHRA AND TSRA WITH THE GREATEST PROBABILITIES RESIDING ALONG THE HIGH TERRAIN. IN ADDITION...MORNING FOG/STRATUS WILL BE POSSIBLE WITH THE MOUNTAINS ONCE AGAIN HAVING THE GREATEST CHANCES AT RESTRICTIONS. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-14Z KCLT MED 70% HIGH 100% HIGH 100% HIGH 90% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% MED 73% MED 74% KHKY MED 66% HIGH 92% MED 66% MED 75% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RWH NEAR TERM...CDG/WIMBERLEY SHORT TERM...RWH LONG TERM...RWH AVIATION...CDG
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
628 AM CDT FRI AUG 29 2014 .DISCUSSION...UPDATED FOR 12Z AVIATION. && .AVIATION...EXPECT SH/TSRA POTENTIAL THROUGH MUCH OF THE DAY FOR EASTERN TAF SITES. LATE THIS EVENING WE SHOULD HAVE A BREAK IN THE ACTIVITY...BUT HAVE PROB 30 GROUP FOR CRP AND VCT AGAIN SATURDAY MORNING FOR ADDITIONAL CONVECTION DEVELOPING. FOR THE MOST PART SHOULD HAVE VFR CIGS THROUGH THE PERIOD...BUT WILL SEE TEMPO MVFR NEAR THUNDERSTORMS. && .PREV DISCUSSION... /ISSUED 424 AM CDT FRI AUG 29 2014/ SHORT TERM (TODAY THROUGH SATURDAY)...WEAK SURFACE LOW AND MID LEVEL WEAKNESS CURRENTLY LOCATED NEAR THE COAST OF DEEP SOUTH TEXAS WITH ABUNDANT MOISTURE ASSOCIATED WITH IT. WHAT HAPPENS TODAY WILL HAVE EVERYTHING TO DO WITH THE MOVEMENT OF THIS LOW THROUGH THE DAY. A NEARLY STATIONARY POSITION WAS THE GENERAL CONSENSUS EARLY TONIGHT...BUT LATEST MESO MODELS ARE STARTING TO SUGGEST THE LOW PULLING SOUTH AND EAST THIS MORNING. THIS WOULD LEAD TO SLIGHTLY LOWER MOISTURE...AND LESS LIFT OVER FORECAST AREA...HOLDING THE MUCH NEEDED RAIN MOSTLY OFFSHORE DURING THE DAY. WHILE THE 06Z HRRR HAS ALSO GONE THIS DIRECTION...WILL STILL HOLD OUT HOPE THAT ENOUGH MOISTURE IS IN PLACE TO VERIFY CHANCE TO LIKELY POPS ACROSS EASTERN AREAS. THERE WAS SOME CONCERN FOR HEAVY RAINFALL...BUT THINK THAT SHOULD REMAIN SOUTH OF FORECAST AREA. HAVE LOWER POPS WEST...BUT THINK SOME AFTERNOON CONVECTION SHOULD MAKE ITS WAY WEST. HAVE GONE A BIT COOLER WITH MAX TEMPS...ESPECIALLY EAST WHERE DEEPER MOISTURE/CLOUD COVER IS EXPECTED. STILL HAVE EVERYONE IN THE 90S...BUT LOWER 90S...ESPECIALLY SOUTHEAST ZONES. TOMORROW NIGHT LOOKS QUITE SIMILAR TO TONIGHT...EXCEPT FEEL BETTER CHANCE FOR POPS WILL BE A BIT FURTHER EAST AS UPPER ENERGY BECOMES ELONGATED JUST OFFSHORE THE MIDDLE TEXAS COAST. HAVE SLIGHTLY LOWER POPS THAN TODAY...AND TEMPS BACK TOWARD NORMAL FOR SATURDAY. A LIGHT TO MODERATE SOUTHEAST WIND CAN BE EXPECTED BOTH FRIDAY AND SATURDAY. LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...UPPER LEVEL WEAKNESS WILL RESIDE OVER SOUTH TEXAS TO BEGIN THE LONG TERM. MOISTURE WILL REMAIN SUFFICIENT ESPECIALLY OVER THE COASTAL PLAINS SATURDAY NIGHT AND SUNDAY...RESULTING IN ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. BY MONDAY...FLATTENED UPPER LEVEL RIDGE WILL SETTLE OVER SOUTH TEXAS ALONG WITH SLIGHTLY DRIER AIR. THIS SHOULD KEEP CHANCES FOR SHOWERS AND STORMS TOO LOW TO MENTION IN THE FORECAST. A TROPICAL WAVE CURRENTLY LOCATED IN THE EASTERN CARIBBEAN WILL CONTINUE TO MOVE WESTWARD THROUGH THE WEEKEND. BY EARLY NEXT WEEK... THIS SYSTEM WILL EMERGE INTO THE BAY OF CAMPECHE AND SOUTHERN GULF OF MEXICO. WHILE DEEPEST MOISTURE SHOULD REMAIN TO THE SOUTH OF THE REGION...PW VALUES WILL RETURN TO AROUND 2 INCHES OVER THE COASTAL LOCATIONS/MARINE ZONES BY WEDNESDAY. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN BY TUESDAY...AND CONTINUING THROUGH THURSDAY. WARMEST DAYS OF THE EXTENDED WILL BE SUNDAY AND MONDAY...WITH TEMPS BEING SET BACK A FEW DEGREES BY MID WEEK AS THE DEEPER MOISTURE RETURNS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 90 78 92 78 96 / 60 40 40 20 30 VICTORIA 93 76 93 76 98 / 50 30 40 20 30 LAREDO 98 79 98 79 103 / 30 30 20 20 10 ALICE 91 77 93 76 99 / 50 30 30 20 20 ROCKPORT 88 79 90 79 93 / 60 40 40 20 30 COTULLA 97 76 97 76 101 / 30 20 20 20 10 KINGSVILLE 91 78 92 78 98 / 60 40 30 20 20 NAVY CORPUS 87 80 89 80 92 / 60 50 40 20 30 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. GM...NONE. && $$ PZ/83...AVIATION
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1022 AM CDT FRI AUG 29 2014 .UPDATE...BOOSTED POPS EARLIER IN THE SE TO ACCOUNT FOR CORRIDOR OF SHRA/TSRA WRAPPING NE ON PERIPHERY OF SE US UPPER RIDGE. ALSO LOWERED POPS IN THE WRN CWA WHERE MORE STABLE AIRMASS RESIDES WITH LINGERING STRATUS. APPEARS UPPER DYNAMICS ASSOCIATED PLAINS MID LEVEL TROUGH AXIS WILL HOLD OFF ON IMPACTING CWA UNTIL TONIGHT. SO LEANING MORE TOWARDS LATEST HRRR VERSUS THE MORE AGGRESSIVE 00Z RUNS OF ARW AND NMM. SURFACE WARM FRONT HAS LIFTED NORTH OUT OF CWA. WITH SOUTH WINDS AS FAR NORTH AS KSBM. PC && .AVIATION/18Z TAFS/...CORRIDOR OF ISOLD/SCT CONVECTION WRAPPING INTO SE WI WILL POTENTIALLY AFFECT THE 3 EASTERN TAF SITES THIS AFTN. MEANWHILE KMSN IS NEAR EASTERN EDGE OF MVFR STRATUS FIELD. EXPECT THIS TO SCATTER A BIT AND LIFT A BIT BUT LIKELY REMAIN AT MVFR LEVELS. EXPECT CONVECTION TO BECOME MORE WIDESPREAD TONIGHT INTO AT LEAST SATURDAY MORNING AS MID LEVEL TROUGH AXIS AND SURFACE LOW MOVE INTO WI. PC && .PREV DISCUSSION... /ISSUED 518 AM CDT FRI AUG 29 2014/ TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM. INFLUENCE OF DRY SOUTHEAST FLOW AROUND WESTERN FLANK OF DEPARTING HIGH PRESSURE EVIDENT IN TIGHT SURFACE DEW POINT GRADIENT THAT REMAINS ALONG IL/WI BORDER AND THE MS RIVER VALLEY. SHOWERS ACROSS CENTRAL/NE WI IN REGION OF 850 MB FRONTOGENETIC RESPONSE TO 20-30 KT WINDS ACROSS EAST-WEST 850 MB BAROCLINIC ZONE BISECTING THE STATE. MCV-DRIVEN POCKET OF SHOWERS/THUNDERSTORMS IN NORTHEAST IOWA IS WEAKENING AS IT LIFTS NE TOWARD SW WI AND INTO THE DRIER...MORE STABLE AIR...WITH THE MCV SHEARING OUT/ WEAKENING AS IT MOVES INTO THE MEAN RIDGE POSITION. HOWEVER MOISTURE TRANSPORT INTO STATE ON 30 KT 850 MB WINDS ALONG WITH ADDITIONAL FORCING FOR ASCENT FROM UPPER LEVEL DIFFLUENCE/DIVERGENCE WILL BE ENOUGH TO SUPPORT THE SHOWERS ACROSS THE NORTHWEST HALF OF THE FORECAST AREA THIS MORNING...WITH SOME SCATTERED SHOWERS IN THE SOUTHEAST. A FEW RUMBLES OF THUNDER ARE POSSIBLE. MODELS INDICATE A BREAK IN THE PCPN LATE THIS MORNING INTO THIS AFTERNOON. UPPER RIDGING SLOWLY MOVING EAST WITH APPROACHING TROUGH OMEGA INCREASES AS LLJ STRENGTHENS LATE THIS AFTERNOON AND EVENING AS MAIN 500 MB TROUGH MOVES INTO WRN WI BY 12Z SAT. NORTHWEST HALF OF FORECAST AREA IN FAVORABLE AREA FOR HEAVY RAIN TONIGHT AS CAPE IS TALL AND SKINNY WITH CORFIDI VECTORS HOVERING AROUND 10KTS...WITH PRECIP WATER VALUES RISING FROM 1.6 TO 2 INCHES. WPC HAS LOCATIONS NORTHWEST OF A PORT WASHINGTON...FORT ATKINSON TO MONROE LINE ARE IN A SLIGHT RISK FOR RAINFALL TO EXCEED FLASH FLOOD GUIDANCE. HOWEVER...WITH PREVIOUS 24 HOURS MUCH DRIER THAN ORIGINALLY FORECAST AND HIGHEST WPC-BASED QPF TOTALS THROUGH SATURDAY MORNING TO THE NORTH AND WEST OF THE FORECAST AREA...WITH IN-CWA TOTALS BELOW THE 1 TO 6-HOUR FLASH FLOOD GUIDANCE BETWEEN 2 AND 3 INCHES...WILL KEEP THE ESF STATEMENT GOING FOR LOCALIZED URBAN/SMALL STREAM FLOODING POTENTIAL BUT NO FLASH FLOOD WATCH AT THIS TIME. SPC HAS A 5 PCT CHANCE FOR WIND GUSTS WITH STEEP LOW-LEVEL LAPSE RATES PRODUCING AN INVERTED V DRY ADIABATIC PROFILE UP TO 4K TO 5K FT ON WESTERN CWA FORECAST SOUNDINGS LATE THIS AFTERNOON/EARLY EVENING IF FORECAST CAPE VALUES CAN BE REALIZED. SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM LATEST MODEL GUIDANCE SUGGEST THAT A SURFACE FRONTAL BOUNDARY AND UPPER LEVEL SHORTWAVE AXIS WILL BE POSITIONED JUST TO THE WEST OF THE FORECAST AREA SATURDAY MORNING. SHOWERS AND STORMS ARE LIKELY AHEAD OF THESE DURING SATURDAY MORNING...WITH A CHANCE CONTINUING INTO THE AFTERNOON AS THE TROUGH MOVES THROUGH AND THE FRONT STALLS NEAR THE WI/IL BORDER. ANOTHER SHORTWAVE WILL MOVE THROUGH SATURDAY EVENING AND OVERNIGHT...BUT KEPT THE FORECAST DRY DUE TO MUCH DRIER AIR ALOFT. SUNDAY THEN LOOKS LIKE A PLEASANT DAY IN BETWEEN LOW PRESSURE SYSTEMS. HIGH TEMPERATURES SATURDAY SHOULD BE RIGHT AROUND NORMAL...RISING TO A COUPLE DEGREES ABOVE NORMAL FOR SUNDAY. MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM SHOWERS AND STORMS ARE LIKELY IN THE WEST BY DAYBREAK MONDAY MORNING AND THEN ACROSS THE FORECAST AREA DURING THE DAY AS A COLD FRONT MOVES THROUGH. SOME STRONGER STORMS ARE POSSIBLE MONDAY...BUT THIS WILL BE DEPENDENT ON THE TIMING OF THE FRONT. IT LOOKS LIKE A DECENT AMOUNT OF INSTABILITY TO GO ALONG WITH AROUND 40 KNOTS OF 0-6 KM BULK SHEAR. MODELS ARE HINTING AT THE FRONT MOVING THROUGH EARLIER IN THE DAY THOUGH...WHICH WOULD LIMIT THE TIME FOR DAYTIME HEATING AND RESULTANT DESTABILIZATION. IT LOOKS MAINLY DRY TUESDAY AND WEDNESDAY WITH THE FRONTAL BOUNDARY AND HIGHER MOISTURE/INSTABILITY REMAINING SOUTH. A RETURN OF MOISTURE UNDER SOUTHERLY LOW LEVEL FLOW MAY BRING SHOWERS AND STORMS BACK TO THE AREA FOR THURSDAY. TEMPERATURES FOR THE MONDAY THROUGH THURSDAY TIME PERIOD SHOULD REMAIN NEAR TO A COUPLE DEGREES ABOVE NORMAL. AVIATION/12Z TAFS/...MOISTURE ADVECTION IS BRINGING IN SOME MVFR/IFR CIGS AND REDUCED VISIBILITIES ALONG AND JUST AHEAD OF THE SURFACE WARM FRONT. THESE LOWER CIGS/VSBYS SHOULD CLEAR THE TAF SITES BY LATE MORNING AS THE FRONT LIFTS NORTH THEN STALLS OVER CENTRAL WISCONSIN. SOME CONCERN FOR KMKE...AND POSSIBLY KENW...THAT IF WINDS ARE MORE SOUTHEAST THAN SOUTH TODAY THAT THE FRONT MAY NOT CLEAR TO THE NORTH AND WILL LEAVE THOSE SITES WITH LESS THAN VFR CONDITIONS THE ENTIRE DAY. WILL GO WITH THE CONSENSUS OF THE MODEL GUIDANCE AND GO WITH PREVAILING VFR TODAY...WITH BRIEF MVFR CIGS/VSBYS WITH SCATTERED SHOWER AND ISOLATED THUNDERSTORMS PASSING THROUGH WITH THE FRONT THIS MORNING. LIKELY TO SEE MVFR SHOWERS AND THUNDERSTORMS SPREAD FROM WEST TO EAST LATER THIS AFTERNOON AND EVENING WITH LOW PRESSURE PASSING THROUGH THE REGION. AGAIN WILL GO WITH NO LOWER THAN MVFR CIGS/VSBYS FOR NOW...THOUGH IFR VSBYS IN HEAVY RAIN POSSIBLE...ESPECIALLY AT KMSN. NAM GUIDANCE HINTING AT IFR/LIFR CIGS AS THE PCPN TAPERS OFF TOWARDS 12Z SATURDAY...BUT CONSENSUS TRACK OF THE LOW KEEPS ENOUGH GRADIENT AT TAF SITES TO KEEP LOW LEVELS MIXED WELL ENOUGH TO PREVENT LOW STRATUS AND FOG...BUT IT WILL HAVE TO BE WATCHED FOR WITH THE NEXT ROUND OF MODEL DATA. MARINE...SOUTHEAST TO SOUTH WINDS WILL GUST TO BETWEEN 20 AND 25 KNOTS AS LOW PRESSURE APPROACHES...BUT NOT FREQUENTLY ENOUGH OR LONG ENOUGH TO WARRANT A SMALL CRAFT ADVISORY AT THIS TIME. HOWEVER SMALL VESSEL OPERATORS SHOULD EXERCISE CAUTION...ESPECIALLY NORTH OF MILWAUKEE WHERE THE LONGER FETCH WILL BUILD HIGHER WAVES. BEACHES...THERE IS A MODERATE SWIM RISK AT THE LAKE MICHIGAN BEACHES FROM SHEBOYGAN TO KENOSHA THIS MORNING THROUGH THIS EVENING WHERE SOUTHEAST TO SOUTH WINDS INCREASING TO 10 TO 20 KNOTS WILL BUILD HIGH WAVES AND RESULT IN STRONG CURRENTS ALONG THE SHORE. RACINE COUNTY IS LISTED AS HAVING A LOW RISK IN THE SURF ZONE FORECAST AS SOME SHELTERING DUE TO SHORELINE TOPOGRAPHY RESULTED IN SLIGHTLY LOWER AVERAGE WAVE HEIGHTS...BUT SWIMMERS SHOULD STILL BE ALERT FOR STRONG CURRENTS AND HIGHER WAVES AT WINDWARD-FACING BEACHES. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SATURDAY THROUGH THURSDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
706 AM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD. LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE 29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30 TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS MORNING. THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF 1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80 PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS. ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES. HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS THE FAR WESTERN SECTIONS SUNDAY AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE 500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80 PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60 PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND 40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN CHANCES WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 700 AM CDT FRI AUG 29 2014 RAIN AREA SHIFTING NORTHWARD SO FEEL ANY RAIN WILL BE OUT OF THE AIRFIELDS BY MID-MORNING. AS UPPER SYSTEM CONTINUES TO MOVE TOWARD THE REGION...LOOKING LIKE THE DRY SLOT WILL PROVIDE FOR SOME PARTIAL SUNSHINE FOR A TIME LATE THIS MORNING. BUT THAT WILL ONLY HELP TO DESTABLIZE THE ATMOSPHERE...LEADING TO MORE CONVECTIVE DEVELOPMENT. VARIOUS MESOSCALE MODEL SOLUTIONS SUGGEST SCATTERED CONVECTION DEVELOPS IN THE WARM AND MOIST AIR...WITH A MORE FOCUSED BAND OF STORMS WHERE SOME FRONTAL CONVERGENCE LOOKS TO EXIST. THIS LOOKS TO BE PRIMARILY NEAR THE KRST AIRFIELD. EITHER WAY...BOTH TAF FORECASTS WILL INCLUDE A TSRA RISK FOR SEVERAL HOURS FROM THE AFTERNOON INTO EVENING. ONCE THE RAIN MOVES THROUGH BY MIDNIGHT...LOW STRATUS AND FOG LOOK TO BE A GOOD BET...WITH LIFR CONDITIONS ANTICIPATED. && .HYDROLOGY... ISSUED AT 309 AM CDT FRI AUG 29 2014 PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF 3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN PRODUCERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...MW HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 PM CDT FRI AUG 29 2014 .MESOSCALE DISCUSSION... 411 PM CDT THUNDERSTORMS ARE GENERALLY ISOLATED IN NORTHEAST ILLNOIS THIS AFTERNOON WITH SCATTERED ACTIVITY EAST OF INTERSTATE 57 IN ILLNOIS AND ALONG THE INTERSTATE CORRIDOR IN NW INDIANA. RADAR ESTIMATES A QUICK THREE QUARTERS OF AN INCH TO 1 INCH HAS FALLEN IN THE HEAVIER DOWNPOURS...WITH STREET FLOODING REPORTED IN LANSING. EXPECT HEAVY RAIN AND LOCALIZED PONDING OF WATER TO REMAIN A THREAT INTO THE EARLY EVENING...ESPECIALLY IN NW INDIANA...THOUGH STORMS MAY INCREASE AS THE WARM FRONT TO THE SOUTH AND DEEPER MOISTURE SPREAD NORTHWARD. KMD && .DISCUSSION... 221 PM CDT SYNOPSIS...UNSETTLED WEATHER CONTINUES THROUGH TOMORROW WITH SCATTERED THUNDERSTORMS EXPECTED. CONFIDENCE REMAINS LOW IN WHEN AND WHERE THUNDERSTORMS WILL FORM. SUNDAY STILL LOOKS DRY BUT MULTIPLE CHANCES FOR STORMS RETURN MONDAY THROUGH THE END OF THE WEEK. ABOVE NORMAL TEMPERATURES ARE ALSO EXPECTED THROUGH THE PERIOD AS WELL. //NEAR TERM FORECAST// THROUGH TONIGHT... A LARGE RIDGE IS OVER THE EAST COAST WHILE A TROUGH IS OVER THE PLAINS. THE TROUGH WILL WEAKEN AS IT APPROACHES OUR AREA AND PASS OVERHEAD LATE SATURDAY NIGHT INTO SUNDAY MORNING. AT THE SURFACE THE HIGH HAS PUSHED EAST WHILE A DEVELOPING LOW PRESSURE SYSTEM IS OVER MINNESOTA. THE LOWS WARM FRONT LIES TO OUR SOUTH ACROSS SOUTHERN IL...AND IT WILL LIFT NORTH THROUGH THE REGION THIS AFTERNOON. HAVE VERY LOW CONFIDENCE IN EXACT TIMING AND LOCATION OF THUNDERSTORMS THROUGH THIS EVENING. THERE IS NO CLEAR FORCING MECHANISM BUT WITH AROUND 2000 J/KG OF CAPE AVAILABLE...STORMS ARE CERTAINLY POSSIBLE. PWAT VALUES ARE AROUND 2 INCHES SO THE MAIN CONCERN REMAINS HEAVY DOWNPOURS. THE STRONGEST STORMS MAY PRODUCE WIND GUSTS TO 50 KT BUT NO SEVERE WEATHER IS EXPECTED AS WIND SHEAR IS BASICALLY NIL. FOR POPS USED A BLEND OF NEAR TERM GUIDANCE WHICH HAS BEEN DOING REASONABLY WELL THIS MORNING. HOWEVER...KEPT A CHANCE OF STORMS ACROSS THE REGION THIS AFTERNOON AND EVENING DUE TO THE SCATTERED NATURE OF THE STORMS THAT ARE EXPECTED. A WASH OUT IS NOT EXPECTED. THE BEST CHANCE FOR WIDESPREAD STORMS WILL BE OVERNIGHT AS THE UPPER LEVEL TROUGH APPROACHES. IN FACT THE STORMS ASSOCIATED WITH THE TROUGH STRETCH FROM MINNESOTA THROUGH ARKANSAS. MODELS DIFFER IN HOW WELL THIS AREA OF PRECIP WILL HOLD TOGETHER SO LIMITED POPS TO THE LIKELY CATEGORY. LOWS WILL BE IN THE UPPER 60S TO LOWER 70S TONIGHT AND FOG IS POSSIBLE. GIVEN THAT WE HAVE NOT SEEN MUCH RAIN TODAY...HAVE LIMITED CONFIDENCE SO LEFT FOG OUT OF THE FORECAST FOR NOW. SATURDAY AND SATURDAY NIGHT... THE SURFACE LOW PASSES OVER LAKE MICHIGAN SATURDAY AFTERNOON WHILE ITS COLD FRONT GETS DRAGGED THROUGH THE AREA SATURDAY AFTERNOON/EVENING. SCATTERED STORMS ARE AGAIN POSSIBLE IN THE MORNING IN THE WARM AND MOIST ENVIRONMENT WITH LINGERING 2 INCH PWAT VALUES. STORMS WILL THEN FORM ALONG THE COLD FRONT SOUTH OF A GARY IN TO PONTIAC IL LINE. STORMS ARE POSSIBLE NORTH AND WEST OF THIS LINE...BUT CONFIDENCE IS SIGNIFICANTLY LOWER. CAPE VALUES WILL BE AROUND 1000 J/KG TOMORROW WITH WEAK SHEAR ONCE AGAIN. THEREFORE EXPECTING STORMS TO PRODUCE HEAVY DOWNPOURS AND THE STRONGEST MAY BE CAPABLE OF GUSTY WINDS. SEVERE WEATHER IS NOT EXPECTED. TOMORROW LOOKS LIKE ANOTHER WARM AND STICKY DAY AHEAD OF THE COLD FRONT. LOWS WILL BE IN THE 60S AND FOG IS POSSIBLE OVERNIGHT. JEE //EXTENDED FORECAST// SUNDAY... EXPECT A BRIEF LULL IN THE PRECIP CHANCES DURING MUCH OF THE DAY SUNDAY AS THE FIRST COLD FRONT DEPARTS TO THE EAST AND ANOTHER LOW TAKES SHAPE OVER THE NORTHERN PLAINS. IN BETWEEN THESE TWO SYSTEMS...WEAK INDUCED SURFACE HIGH SHOULD RESULT IN QUIET WEATHER LOCALLY...WITH THE H85 THERMAL RIDGE ADVECTING OVERHEARD THROUGHOUT THE DAY. RETURN FLOW WILL HELP PUSH THE DEWPOINTS BACK UP TO AROUND 70 WITH AFTERNOON HIGH TEMPS EXPECTED TO BE IN THE MID 80S. STEEP LOW/MID LEVEL LAPSE RATES WILL RESULT IN MODERATE INSTABILITY DEVELOPING DURING THE AFTERNOON...BUT MODEST SBCIN IS PROGGED TO STAY IN PLACE CAPPING ANY SURFACE BASED CONVECTION. IN ADDITION... THE AREA SHOULD BE SQUARELY UNDER AREA OF MID LEVEL HEIGHT RISES WHICH SHOULD HELP REINFORCE THE INVERSION...AND NO SIGNIFICANT FORCING NOTED OVER THE AREA. MONDAY... TROUGHING CURRENTLY MOVING ONSHORE OVER THE PAC NORTHWEST TODAY WILL MOVE ACROSS THE CENTRAL PLAINS THIS WEEKEND...THEN BEGIN TO LIFT ACROSS THE UPPER MIDWEST EARLY NEXT WEEK. SURFACE LOW IS PROGGED TO DEEPEN FROM THE NORTHERN PLAINS SUNDAY AS IT LIFTS TO NEAR HUDSON BAY LATE ON MONDAY. THIS WILL DRAG A COLD FRONT ACROSS THE REGION ON MONDAY. WITH THE LOW LIFTING AWAY FROM THE AREA...CONVERGENCE ALONG THE FRONT IS PROGGED TO WEAKEN AS IT COMES ACROSS NORTHERN ILLINOIS EARLY MONDAY WITH THE BETTER DYNAMICS STAYING TO OUR NORTH. MEANWHILE...THE LOCAL AREA APPEARS TO LIE ON THE NORTHERN PERIPHERY OF THE BETTER INSTABILITY TO OUR SOUTH. GFS SHOWS SOME HINTS THAT PARTICULARLY NORTH CENTRAL ILLINOIS MAY BE SPLIT BY THE PRECIP...ESPECIALLY CONSIDERING THE CAPPING EARLY IN THE DAY...BUT WILL HOLD OFF ON FINE TUNING THIS DETAIL FOR NOW. IN ADDITION...THE REGION DOES FALL WITHIN AN OVERLAPPED AREA OF FAVORABLE SHEAR/INSTABILITY THAT COULD POTENTIALLY SUPPORT A SEVERE WEATHER THREAT. TUESDAY THROUGH FRIDAY... FRONTAL BOUNDARY IS PROGGED TO STALL ACROSS/NEAR CENTRAL ILLINOIS TUESDAY GRADUALLY LIFTING BACK NORTH ACROSS THE FORECAST AREA BY THE END OF THE WORK WEEK AS A SERIES OF UPPER LEVEL DISTURBANCES MOVE ACROSS THE REGION. THIS WILL RESULT IN PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS THE AREA...THOUGH TIMING AND LOCATION DETAILS WILL BE DIFFICULT TO PIN DOWN THIS FAR OUT GIVEN THE PATTERN. THE ATMOSPHERE REMAINS QUITE SOUPY IN THE VICINITY OF THE FRONT WHERE PWATS REMAIN AROUND 2 INCHES. THUS THE HEAVY RAIN AND FLOODING THREAT WILL HAVE TO BE CLOSELY MONITORED THROUGH MUCH OF THE UPCOMING WEEK. DEUBELBEISS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * ISOLATED-SCATTERED SHRA/TSRA THIS AFTERNOON THRU EARLY EVENING. * SOUTH WINDS WITH GUSTS 15-20 KT THIS AFTERNOON. * ANOTHER PERIOD OF SHRA/TSRA LIKELY AFTER MIDNIGHT INTO SATURDAY MORNING. * SOUTHWEST WINDS GUSTING AROUND 20 KT SATURDAY. RATZER //DISCUSSION...UPDATED 20Z... ISOLATED TSRA DEVELOPING FROM NORTHEAST OF DOWNTOWN CHICAGO SOUTH INTO IKK AREA. THINK COVERAGE WILL REMAIN FAIRLY LOW...THOUGH HAVE ADDED VCTS FOR THE NEXT FEW HOURS FOR CHICAGO TERMINALS AS THEY WILL BE SPARSE BUT IN THE NEIGHBORHOOD SO TO SPEAK. RATZER PREVIOUS DISCUSSION FROM 18Z... FAIRLY LOW CONFIDENCE CONVECTIVE FORECAST THIS PERIOD...WITH TERMINALS WITHIN A BROAD AREA OF SOUTH WARM/MOIST ADVECTION DOWNSTREAM OF AN UPPER TROUGH OVER THE CENTRAL PLAINS BUT WITH OTHERWISE LITTLE ORGANIZED FOCUS FOR TSRA. SATELLITE EVIDENCE OF WEAK MID-LEVEL DISTURBANCE OVER NORTHEAST IL EARLY THIS AFTERNOON...WITH MORNING ELEVATED SHRA/TSRA DECAYING OVER NORTH CENTRAL IL. DIURNAL TSRA WERE FORMING IN LOW LEVEL INSTABILITY AXIS ALONG IL/IN BORDER REGION GENERALLY ALONG A DEC- GIJ-MKG LINE...AND THIS LOOKS TO REMAIN THE FOCUS REGION FOR HIGHEST COVERAGE TSRA THIS AFTERNOON. HIGH-RES GUIDANCE STILL DEVELOPS SOME ISOLATED SHRA/TSRA INTO THE TERMINAL REGION IN ASSOCIATION WITH AFOREMENTIONED MID-LEVEL DISTURBANCE AND NORTH OF SURFACE WARM FRONT WHICH IS ACROSS DOWNSTATE IL AT THIS TIME... THOUGH COVERAGE IS EXPECTED TO REMAIN LOW. A GREATER CHANCE OF SHRA/TSRA APPEARS TO BE LATE TONIGHT AND EARLY SATURDAY AS THE MAIN UPPER TROUGH APPROACHES. WEAK COLD FRONT APPROACHES FROM THE WEST SATURDAY MIDDAY AND AFTERNOON...WITH THUNDERSTORMS EXPECTED TO DEVELOP ALONG THE FRONT BY EARLY AFTERNOON. CURRENT SUITE OF HIGH-RES GUIDANCE SUGGESTS TSRA POTENTIAL MAY BE GREATER JUST EAST/SOUTH OF CHICAGO TERMINALS SATURDAY AFTERNOON. OUTSIDE OF ANY PRECIP VIS REDUCTION EARLY SATURDAY...SOME MVFR HAZE POSSIBLE OVERNIGHT IN MOIST WARM SECTOR AIR. WINDS...GENERALLY SOUTH 10-12 KT WITH GUSTS TO 20 KT OR SO POSSIBLE THIS AFTERNOON. WIND MAY BACK A BIT TO THE SOUTH- SOUTHEAST LATE THIS AFTERNOON/EARLY EVENING AS SURFACE WARM FRONT APPROACHES...BEFORE SHIFTING SOUTHWEST OVERNIGHT AND SUNDAY AHEAD OF THE COLD FRONT. DEEPER MIXING SUNDAY SUGGESTS GUSTS AGAIN IN THE 20 KT RANGE OR A LITTLE HIGHER DURING THE LATE MORNING AND AFTERNOON. RATZER //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM IN SHRA/TSRA BEING LOW IN COVERAGE IN IMMEDIATE TERMINAL AREA THIS AFTERNOON...GREATER COVERAGE EAST/SOUTH OF CHICAGO. * LOW IN TSRA TIMING/COVERAGE LATER TONIGHT/SATURDAY. * MEDIUM-HIGH IN WIND TRENDS THROUGH PERIOD. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... * SATURDAY NIGHT THROUGH SUNDAY NIGHT...VFR. WX NIL. * MONDAY...CHANCE OF TSRA. * TUESDAY...VFR. WX NIL. * WEDNESDAY THROUGH THURSDAY NIGHT...SLIGHT CHANCE OF TSRA KREIN && .MARINE... 221 PM CDT MODERATE SOUTHERLY WINDS ARE IN PLACE TODAY AHEAD OF LOW PRESSURE OVER THE NORTHERN PLAINS. SOUTH TO SOUTHWEST WINDS 20 TO 25 KT WITH AN OCCASIONAL 30 KT GUSTS POSSIBLE WILL BE IN PLACE THROUGH TOMORROW...THEN A COLD FRONT WILL START TO PUSH ACROSS THE LAKE TURNING WINDS NORTHWESTERLY. HIGH PRESSURE WILL PROVIDE A BRIEF LULL IN THE WINDS SUNDAY ALLOWING LAKE BREEZES TO DEVELOP...BUT THEN SOUTHERLY WINDS RAMP BACK UP TO 25 TO 30 KT SUNDAY NIGHT INTO MONDAY AHEAD OF ANOTHER LOW. THIS LOW IS PROGGED TO DEEPEN AS IT LIFTS FROM THE NORTHERN PLAINS SUNDAY TO HUDSON BAY LATE MONDAY. BMD && .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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 303 PM CDT Fri Aug 29 2014 .SHORT TERM...(This evening through Saturday) ISSUED AT 302 PM CDT FRI AUG 29 2014 19z/2pm surface analysis shows warm front extending from southern Minnesota to southern Indiana, generally along the I-74 corridor across central Illinois. Widely scattered showers and thunderstorms have developed along the front and will continue to do so for the balance of the afternoon. Meanwhile further upstream, a trough of low pressure is evident across central Missouri where thunderstorms are becoming more numerous. As this trough shifts northeastward, storm chances will begin to increase across southwest Illinois early this evening, then across the entire KILX CWA by mid to late evening. May see a gradual decrease in areal coverage as daytime instability is lost, so will keep PoPs in the 50-60 range tonight. As has been the case for the past several days, any storms that occur will be capable of frequent lightning and very high rainfall rates of 1.5 to 2 inches per hour. The trough axis will lift northeast of the area late tonight into Saturday morning, with only scattered showers/storms lingering early in the day. As a cold front currently across the Plains pushes eastward and interacts with the very moist airmass in place across the region, a renewed round of convection will be likely Saturday afternoon/evening. Will carry high chance PoPs in the Illinois River Valley and likely further east across the remainder of the CWA accordingly. && .LONG TERM...(Saturday night through Friday) ISSUED AT 302 PM CDT FRI AUG 29 2014 In the wake of Saturdays precip, the boundary at the sfc slows and becomes a bit more diffuse overall and models are starting to speed up the clearing as the boundary slips to the southeast into the Ohio River Valley. Though precip chances linger in southern and east central Illinois on Saturday night, Sunday may be a break in the widespread chances for rain. Next wave slowing in the 12z runs of the ECMWF and the NAM...though the wave aloft is slowing, the GFS qpf is slower to respond. Postponing the pops resulting in a dry Sunday evening for the eastern half of the state with pops increasing in the overnight hours along and west of Interstate 55, with precip spreading and dominating much of the day on Monday. Given the high PW values in the atmosphere, heavy rains will remain a threat for the forecast pd. Delaying the onset of precip from Sunday night into Monday also resulting in a prolonging into Monday night. Question for the models beyond Monday night really revolving around the boundary stalling in quasi zonal flow aloft not really supporting any major progression of the sfc boundary and yet another pd of being just on the edge of the unsettled weather with a signif lack of 500mb height gradient over the southern half of the CONUS. Whereas the GFS is pushing a series of MCSs on the edge of the weak flow, the ECMWF is far more conservative...though both models are tempering the amplification significantly over the latter half of the work week. Thermal ridging in the south keeps above normal temps over the region. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 1250 PM CDT FRI AUG 29 2014 Widely scattered thunderstorms will continue to develop across central Illinois over the next couple of hours as a warm front lifts north of the area. Will carry VCTS at all terminals accordingly. Meanwhile further upstream, regional radar mosaic is showing a band of showers/thunder developing across western Missouri into northern Arkansas. HRRR is showing this band lifting N/NE this afternoon, eventually arriving in west-central Illinois early this evening. Have therefore opted to carry predominant light rain with VCTS for a 6-hour period at all sites this evening into the overnight hours. Based on HRRR and observed trends, have brought precip into KSPI after 02z, then further east to KCMI after 05z. After this initial band lifts through the area, only widely scattered showers will be noted Saturday morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...HJS AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
107 PM CDT FRI AUG 29 2014 .DISCUSSION... 326 AM CDT THE MAIN FORECAST CONCERNS WILL CENTER AROUND CONVECTIVE CHANCES AND TIMING...AS WELL AS TEMPERATURES TODAY...AND THROUGH THE HOLIDAY WEEKEND. CURRENTLY...THE REMNANT MCV FROM YESTERDAY EVENINGS SHOWERS AND STORMS CONTINUES TO SHIFT ACROSS MY SOUTHERN COUNTIES EARLY THIS MORNING. HOWEVER...ONLY A FEW LIGHT SHOWERS/SPRINKLES REMAIN ACROSS THIS AREA...WITH DRIER AND FAIRLY STABLE CONDITIONS IN PLACE TO THE EAST. ANOTHER AREA OF CONVECTION IS ONGOING TO OUR WEST ACROSS IOWA AND INTO SOUTHERN MN. THIS ACTIVITY IS OCCURRING WITHIN A REGION OF GOOD LOWER LEVEL WARM AIR ADVECTION/ISENTROPIC ASCENT ON THE DOWNSTREAM PERIPHERY OF A REMNANT MID/UPPER LEVEL TROUGH OVER THE PLAINS STATES. DOWN STREAM UPPER RIDGING OVER THE GREAT LAKES REGION IS LEADING TO A STEERING FLOW TO THE NORTHEAST. THEREFORE...MOST IF NOT ALL OF THIS CONVECTIVE ACTIVITY WILL SHIFT INTO SOUTHERN WISCONSIN AND PERHAPS FAR NORTHWESTERN ILLINOIS THIS MORNING. IN SPITE OF THIS...I HAVE LEFT SLIGHT CHANCE POPS IN THIS MORNING AS IT IS POSSIBLE THAT SOME ADDITIONAL CELLS COULD DEVELOP IN ASSOCIATION WITH AN EASTWARD MOVING OUTFLOW BOUNDARY...AS EVIDENT OFF OF THE DMX RADAR MOVING TOWARDS EASTERN IOWA. THIS ACTIVITY...IF IT OCCURS IN ANY OF NORTHERN ILLINOIS EARLY THIS MORNING...WOULD LIKELY BE ISOLATED TO WIDELY SCATTERED...WITH THE MAIN FOCUS REMAINING NORTH. A SURFACE WARM FRONT IS EXPECTED TO LIFT NORTHWARD OVER THE AREA INTO THIS AFTERNOON...WITH A WARMER AIRMASS EXPECTED IN ITS WAKE. IN SPITE OF THIS...HOWEVER...HIGH TEMPERATURES ACROSS THE AREA WILL BE TRICKY AS IT APPEARS THAT SOME SCATTERED THUNDERSTORMS COULD DEVELOP ACROSS PORTIONS OF THE AREA THIS AFTERNOON...AND HAMPER THE MAGNITUDE OF THE WARMTH ACROSS SOME AREAS. MODEST HEIGHT FALLS ALOFT ARE FORECAST ACROSS NORTHERN ILLINOIS IN ASSOCIATION WITH THE AFOREMENTIONED UPPER TROUGH SHIFTING EASTWARD OVER THE MID MISSOURI VALLEY THIS AFTERNOON. IN SPITE OF THE FACT THAT THE BEST LARGE SCALE FORCING FOR ASCENT WITH THIS DISTURBANCE SHOULD REMAIN WEST OF THE AREA THIS AFTERNOON...THE EXPECTED INCREASE IN LOW-LEVEL THETA E IS EXPECTED TO PRODUCE AN UNCAPPED ATMOSPHERE FEATURING MLCAPES OF AROUND 1500 J/KG BY THIS AFTERNOON. A MAJORITY OF THE GLOBAL MODELS...AS WELL AS THE HIRES CONVECTIVE ALLOWING MODELS FIRE UP ACTIVITY WITHIN THIS REGIME THIS AFTERNOON. IT APPEARS WE WILL HAVE TO WATCH MORNING CLOUD COVER...HOWEVER...AS THIS COULD INHIBIT THE DEGREE OF WARMING A BIT THROUGH THE MORNING...AND POSSIBLY LEAD TO WEAKER INSTABILITY THAN WHAT THE MODELS ARE CURRENTLY ADVERTISING. IF THE CONVECTION DOES DEVELOP AS EXPECTED...MARGINAL DEEP LAYER SHEAR OF 25 TO 30 KT COULD ALLOW FOR A FEW STRONGER STORMS CAPABLE OF SOME ISOLATED HIGH WIND GUSTS. SOME TORRENTIAL DOWNPOURS WOULD ALSO BE A THREAT FROM THESE STORMS GIVEN THE JUICY AIRMASS FEATURING PWATS UP AROUND 1.75 INCHES. HOWEVER...EXTREME RAINFALL AMOUNTS APPEAR UNLIKELY GIVEN STORM MOTIONS SHOULD BE TO THE NORTHEAST AROUND 30 KT. SO THE STORMS SHOULD NOT BE OVER A GIVEN AREA TOO LONG. MUCH OF THIS ACTIVITY APPEARS TO BE HIGHLY DIURNAL IN NATURE...SO A RAPID DOWNWARD TREND IS EXPECTED AFTER SUNSET THIS EVENING. ANOTHER ROUND OF THUNDERSTORMS APPEARS LIKELY ON SATURDAY...ESPECIALLY DURING THE MORNING AS THE UPPER LEVEL TROUGH...AND AN ASSOCIATED SURFACE LOW AND COLD FRONT SHIFTS EASTWARD ACROSS ACROSS SOUTHERN WI AND NORTHERN IL. THIS ACTIVITY COULD LINGER INTO SATURDAY EVENING ACROSS MY FAR SOUTHEASTERN COUNTIES. HOWEVER...IT APPEARS THAT FOLLOWING THIS FRONTAL PASSAGE WE WILL BE GREETED WITH A NICE DRY SUNDAY ACROSS THE AREA. UNFORTUNATELY...LABOR DAY APPEARS THAT IT COULD BE ANOTHER ACTIVE WEATHER DAY ACROSS THE REGION. ANOTHER POTENT UPPER LEVEL DISTURBANCE AND SURFACE FRONT IS FORECAST TO SHIFT OVER THE AREA BY MONDAY. WE WILL ALSO HAVE TO WATCH FOR THE THREAT OF SEVERE THUNDERSTORMS ON MONDAY AND MONDAY NIGHT AS A 45 TO 50 KT MID LEVEL JET IS PROGGED TO DEVELOP ACROSS THE AREA. THIS COULD RESULT IN DEEP LAYER SHEAR STRONG ENOUGH TO PRODUCE MORE ORGANIZED STRONG TO SEVERE CONVECTION. VERY HEAVY RAINFALL WOULD AGAIN BE A CONCERN WITH THIS ACTIVITY...ESPECIALLY IF THE FRONTAL ZONE STALLS OUT OVER THE AREA MONDAY NIGHT. AT THIS TIME...HOWEVER...UNCERTAINTY IS HIGH ON WHERE THE SURFACE FRONT MAY STALL AND HENCE WHAT AREAS COULD BE FAVORED FOR EXTENDED PERIODS OF VERY HEAVY RAINFALL. THE ACTIVE WEATHER PATTERN COULD SHIFT SOUTH OF THE AREA FOR A DAY OR TWO INTO MID TO LATE WEEK BEFORE MORE PERIODS OF CONVECTION ARE POSSIBLE. OVERALL...IT APPEARS TEMPERATURES WILL REMAIN ON THE WARM SIDE OF AVERAGE...WITH THE POTENTIAL FOR SOME VERY WARM AND HUMID DAYS LATER NEXT WEEK. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * ISOLATED-SCATTERED SHRA/TSRA THIS AFTERNOON THRU EARLY EVENING. * SOUTH WINDS WITH GUSTS 15-20 KT THIS AFTERNOON. * ANOTHER PERIOD OF SHRA/TSRA LIKELY AFTER MIDNIGHT INTO SATURDAY MORNING. * SOUTHWEST WINDS GUSTING AROUND 20 KT SATURDAY. RATZER //DISCUSSION...UPDATED 18Z... FAIRLY LOW CONFIDENCE CONVECTIVE FORECAST THIS PERIOD...WITH TERMINALS WITHIN A BROAD AREA OF SOUTH WARM/MOIST ADVECTION DOWNSTREAM OF AN UPPER TROUGH OVER THE CENTRAL PLAINS BUT WITH OTHERWISE LITTLE ORGANIZED FOCUS FOR TSRA. SATELLITE EVIDENCE OF WEAK MID-LEVEL DISTURBANCE OVER NORTHEAST IL EARLY THIS AFTERNOON...WITH MORNING ELEVATED SHRA/TSRA DECAYING OVER NORTH CENTRAL IL. DIURNAL TSRA WERE FORMING IN LOW LEVEL INSTABILITY AXIS ALONG IL/IN BORDER REGION GENERALLY ALONG A DEC- GIJ-MKG LINE...AND THIS LOOKS TO REMAIN THE FOCUS REGION FOR HIGHEST COVERAGE TSRA THIS AFTERNOON. HIGH-RES GUIDANCE STILL DEVELOPS SOME ISOLATED SHRA/TSRA INTO THE TERMINAL REGION IN ASSOCIATION WITH AFOREMENTIONED MID-LEVEL DISTURBANCE AND NORTH OF SURFACE WARM FRONT WHICH IS ACROSS DOWNSTATE IL AT THIS TIME... THOUGH COVERAGE IS EXPECTED TO REMAIN LOW. A GREATER CHANCE OF SHRA/TSRA APPEARS TO BE LATE TONIGHT AND EARLY SATURDAY AS THE MAIN UPPER TROUGH APPROACHES. WEAK COLD FRONT APPROACHES FROM THE WEST SATURDAY MIDDAY AND AFTERNOON...WITH THUNDERSTORMS EXPECTED TO DEVELOP ALONG THE FRONT BY EARLY AFTERNOON. CURRENT SUITE OF HIGH-RES GUIDANCE SUGGESTS TSRA POTENTIAL MAY BE GREATER JUST EAST/SOUTH OF CHICAGO TERMINALS SATURDAY AFTERNOON. OUTSIDE OF ANY PRECIP VIS REDUCTION EARLY SATURDAY...SOME MVFR HAZE POSSIBLE OVERNIGHT IN MOIST WARM SECTOR AIR. WINDS...GENERALLY SOUTH 10-12 KT WITH GUSTS TO 20 KT OR SO POSSIBLE THIS AFTERNOON. WIND MAY BACK A BIT TO THE SOUTH- SOUTHEAST LATE THIS AFTERNOON/EARLY EVENING AS SURFACE WARM FRONT APPROACHES...BEFORE SHIFTING SOUTHWEST OVERNIGHT AND SUNDAY AHEAD OF THE COLD FRONT. DEEPER MIXING SUNDAY SUGGESTS GUSTS AGAIN IN THE 20 KT RANGE OR A LITTLE HIGHER DURING THE LATE MORNING AND AFTERNOON. RATZER //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM IN SHRA/TSRA BEING LOW IN COVERAGE IN IMMEDIATE TERMINAL AREA THIS AFTERNOON...GREATER COVERAGE EAST/SOUTH OF CHICAGO. * LOW IN TSRA TIMING/COVERAGE LATER TONIGHT/SATURDAY. * MEDIUM-HIGH IN WIND TRENDS THROUGH PERIOD. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... * SATURDAY NIGHT THROUGH SUNDAY NIGHT...VFR. WX NIL. * MONDAY...CHANCE OF TSRA. * TUESDAY...VFR. WX NIL. * WEDNESDAY THROUGH THURSDAY NIGHT...SLIGHT CHANCE OF TSRA KREIN && .MARINE... 315 AM CDT HIGH PRESSURE OVER THE EASTERN GREAT LAKES WILL MOVE EAST OFF THE NEW ENGLAND COAST FRIDAY EVENING...WHILE A TROUGH OF LOW PRESSURE DEVELOPS ACROSS THE CENTRAL PLAINS AND UPPER MIDWEST. THIS WILL SET UP A PERIOD OF SOUTHERLY WINDS AND AS THE TROUGH MOVES EAST...THE GRADIENT OVER THE LAKE WILL STRENGTHEN AND WINDS SHOULD INCREASE TO THE 20-25 KT RANGE. A DEEPENING LOW CENTER WITHIN THE TROUGH WILL MOVE TO WISCONSIN SATURDAY AND ACROSS NORTHERN LAKE MICHIGAN SATURDAY EVENING. AS THE LOW TRACKS TO THE NORTHEAST...AN ASSOCIATED COLD FRONT WILL MOVE DOWN THE LAKE SATURDAY AFTERNOON AND EVENING...QUICKLY SHIFTING WINDS TO NWLY FOLLOWING THE FROPA. THE LATEST MODEL GUIDANCE SUGGESTS THAT THE FRONT WILL WASH OUT LATE SATURDAY NIGHT BEFORE REACHING THE SOUTH END OF THE LAKE AND WINDS THERE SHOULD NEVER TRULY SHIFT NWLY...BUT RATHER BECOMING LIGHT AND VARIABLE LATE SATURDAY NIGHT THROUGH SUNDAY MORNING. A DEEPER LOW IS EXPECTED TO DEVELOP OVER THE DAKOTAS AND LIFT THROUGH WESTERN ONTARIO SUNDAY NIGHT AND MONDAY BRINGING A RETURN TO BRISK SOUTH TO SOUTHWEST WINDS TO THE LAKE FOR MONDAY AND TUESDAY. KREIN && .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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion NATIONAL WEATHER SERVICE LINCOLN IL 1250 PM CDT Fri Aug 29 2014 .UPDATE... ISSUED AT 948 AM CDT FRI AUG 29 2014 Made a quick update to the forecast to raise PoPs from Lincoln northward to Henry due to current radar trends. A cluster of thunderstorms with high rainfall rates of 1.5 to 2 inches per hour is lifting northward into Tazewell and western McLean counties at this time and will continue northward across Woodford and Marshall counties over the next couple of hours. Once this cluster weakens/exits the KILX CWA toward midday, additional showers/storms will develop along outflow boundaries as well as the synoptic warm front as it pushes northward later today. Have gone with low chance PoPs across the board this afternoon, with highs climbing well into the 80s. && .SHORT TERM...(Today and tonight) ISSUED AT 337 AM CDT FRI AUG 29 2014 Frontal boundary from NW Missouri through southern Illinois into Kentucky will push northward today as southwesterly flow increases ahead of a trough currently over the central plains. For this afternoon convection will be primarily driven by surface heating and not well organized, therefore have ramped up pops through early afternoon and trended them downward in early evening in eastern IL. In the early evening, the upper level trough and weak surface cold front associated with the plains system begin to move into western IL. This will bring a good chance of showers and thunderstorms pushing across central and southeast IL overnight. Temperatures for today will be similar to Thursdays...generally mid to upper 80s with dew points in the low 70s resulting in heat index values in the low to mid 90s. && .LONG TERM...(Saturday through Thursday) ISSUED AT 337 AM CDT FRI AUG 29 2014 Cold front accompanying current deep Plains upper trough will be losing some of its punch as it comes into the mid-Mississippi Valley, but will still be potent enough for showers and thunderstorms to be likely on Saturday over our area. Some heavier rains will be possible with the stronger storms, primarily over the southeast CWA where precipitable water values will be around 1.8 inches Saturday afternoon, about 2 standard deviations above normal for the end of August. The precipitation threat will continue Saturday night and Sunday over the southeast CWA as moisture continues to surge into the Ohio Valley. However, the northwest half of the forecast area should be dry during this period. West-east upper high to dominate the lower CONUS into mid week, as a broad trough tracks across the northern states. Showers and storms ahead of the surface front should begin spreading in northwest of the I-55 corridor after midnight Sunday night. Most of the models try to form some sort of dual MCS`s, one tracking east across Wisconsin and the other southwest through Missouri, with some potential for lesser amounts of rain Monday morning. However, redevelopment is expected by afternoon as the front starts to hang up in the upper flow, so have likely PoP`s over most of the CWA for Monday. With the frontal boundary in the vicinity, the 00Z models are trending more toward additional MCS activity tracking over our forecast area Monday night. Have increased the PoP`s some, especially across the north which had been dry Monday night. The front should start to be dragged a bit further south on Tuesday as a surface wave moves along it, but have kept PoP`s in the 30-40% range into Tuesday night before the focus shifts more into the Ohio Valley. Mid to late week, the upper high begins to ridge again across the Mississippi Valley. 850 mb temperatures of 20-22C should allow for highs to return to the 90s late next week. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 1250 PM CDT FRI AUG 29 2014 Widely scattered thunderstorms will continue to develop across central Illinois over the next couple of hours as a warm front lifts north of the area. Will carry VCTS at all terminals accordingly. Meanwhile further upstream, regional radar mosaic is showing a band of showers/thunder developing across western Missouri into northern Arkansas. HRRR is showing this band lifting N/NE this afternoon, eventually arriving in west-central Illinois early this evening. Have therefore opted to carry predominant light rain with VCTS for a 6-hour period at all sites this evening into the overnight hours. Based on HRRR and observed trends, have brought precip into KSPI after 02z, then further east to KCMI after 05z. After this initial band lifts through the area, only widely scattered showers will be noted Saturday morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARNES SHORT TERM...ONTON LONG TERM...GEELHART AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
212 PM CDT FRI AUG 29 2014 .SYNOPSIS... ISSUED AT 1244 PM CDT FRI AUG 29 2014 A DEEP RICH MOISTURE PLUME CONTINUES TO FEED INTO EASTERN IOWA AND MUCH OF THE UPPER MIDWEST. OUR CWA FELL WEST OF A FEW HEAVY RAIN PRODUCING STORMS IN ILLINOIS EARLIER TODAY...AND UNDER A WEAK AREA OF SUBSIDENCE THROUGH EARLY AFTERNOON. THIS HAS ALLOWED LOW LEVELS TO HEAT UP UNINHIBITED. AS OF 1 PM...WIDESPREAD LOWER TO MID 80S ARE FOUND OVER EASTERN IOWA AND WESTERN ILLINOIS...WITH DEWPOINTS IN THE 70 TO 73 RANGE. HIGHS TODAY SHOULD REACH THE MID TO UPPER 80S. CAPE VALUES ESTIMATED BY SPC RAP AS OF 1 PM ARE 2000 TO 3000 OVER ALL OF THE CWA. A VORTICITY MAXIMA IS LOCATED IN EASTERN KS...WITH A PVA WING OF LIFT FOUND INTO CENTRAL MISSOURI. THIS IS ALREADY DEVELOPING A LINE OF DEEP CONVECTION FROM NORTH CENTRAL TO SOUTH && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 1244 PM CDT FRI AUG 29 2014 THE VORT MAX TO THE SOUTHWEST WILL LIFT THROUGH IOWA THIS EVENING...HELPING ORGANIZE STORMS AS THEY MOVE THROUGH THE CWA. FROM LATE AFTERNOON THROUGH MID EVENING...THESE SHOULD IMPACT MUCH OF THE CWA. A LACK OF SHEAR SHOULD DECREASE ANY WIDESPREAD SEVERE WEATHER THREAT...BUT SOME ISOLATED WIND DAMAGE IS POSSIBLE THROUGH WET MICROBURST ACTIVITY IN THE STRONGEST CELLS. OTHERWISE....THIS SHOULD BE HEAVY RAIN PRODUCING LINE OF STORMS...WITH SOME BRIEF TRAINING POSSIBLE. A WIDESPREAD RAIN OF 0.25 TO 0.75 IS EXPECTED...WITH SWATHS OF 1 TO 2 INCHES. WE ARE LIKELY TO HANDLE THIS MINOR FLOOD/URBAN RUNOFF THREAT WITH SPS PRODUCTS. TONIGHT...STORMS SHOULD BECOME LESS NUMEROUS...AND POSSIBLY END FULLY. HOWEVER...WITH THE PARENT VORT MOVING BY WITH AMPLE MOISTURE...WE WILL LEAVE POPS GOING THROUGH THE NIGHT. SATURDAY...MODELS BRING ANOTHER QUICK SHOT OF ENERGY THROUGH WHILE MOISTURE IS DEPARTING. THIS MAY BRING SOME SHOWERS AND STORMS TO ROUGHLY THE EAST HALF...BUT SHOULD SUBSIDENCE BECOME MORE CONFIDENT BEHIND TONIGHTS STORMS...WE MAY BE DRY ALL DAY SATURDAY. TEMPERATURES LOOK MILD TONIGHT...IN THE UPPER 60S...WHILE SATURDAY SHOULD SEE A DRY AFTERNOON REBOUND TO THE UPPER 70S TO LOWER 80S. CLOUDS WHILE THICK IN THE MORNING SHOULD BECOME SCATTERED BY MID DAY. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 1244 PM CDT FRI AUG 29 2014 THE MAIN FORECAST CONCERN IN THE LONG TERM PERIOD IS STORM COVERAGE/RAINFALL AMOUNTS/SEVERE POTENTIAL WITH THE ARRIVAL OF THE NEXT SYSTEM SUNDAY NIGHT INTO MONDAY. EARLY IN THE PERIOD...HAVE MAINTAINED DRY FORECAST FOR SATURDAY NIGHT THROUGH SUNDAY AFTERNOON. MEDIUM RANGE MODELS HAVE CONTINUED A GENERAL TREND OF SLOWING THE ARRIVAL OF THE NEXT FRONTAL BOUNDARY AND UPPER LEVEL TROUGH. HAVE REDUCED AND TRIMMED POPS BACK TO THE NORTHWEST FOR SUNDAY EVENING...AND ADDITIONAL ADJUSTMENTS MAY BE NEEDED OVER THE NEXT COUPLE OF DAYS. THE MAIN WINDOW OF SHOWERS/STORMS IS NOW EXPECTED LATE SUNDAY NIGHT INTO MONDAY MORNING. THE LATER TIMING MEANS FAVORABLE SEVERE WEATHER PARAMETERS WILL LIKELY STAY WEST OF THE FORECAST AREA...WITH THE MOST LIKELY SCENARIO BEING A DECAYING MCS AND POSSIBLY SOME LOCALLY HEAVY RAIN. STORMS MAY CONTINUE INTO THE AFTERNOON...AND POSSIBLY MONDAY NIGHT DEPENDING ON HOW FAR SOUTH THE FRONT PUSHES. LOOKING AHEAD...CONFIDENCE IN FORECAST DETAILS IS LOWER AS THE OPERATIONAL GFS AND EURO VACILLATE BETWEEN WEAK TROUGHING AND ZONAL FLOW ACROSS THE REGION. TIMING AND LOCATION OF THE VARIOUS WEAK IMPULSES IS CHALLENGING AND RIGHT NOW THERE IS NO REASON TO VARY FROM THE CONSENSUS BLEND POPS...ESSENTIALLY SLIGHT TO LOW CHANCE IN EVERY PERIOD THROUGH FRIDAY. TEMPERATURES ARE EXPECTED TO BE NEAR TO SLIGHT ABOVE NORMAL THROUGH THE PERIOD...WITH AFTERNOON HIGHS GENERALLY IN THE 8OS AND LOWS IN THE 60S TO LOWER 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1244 PM CDT FRI AUG 29 2014 A LARGE AREA OF STORMS WILL SWEEP NORTHEAST THROUGH EASTERN IOWA AND NORTHWEST ILLINOIS BETWEEN 21Z AND 04Z THIS AFTERNOON AND TONIGHT. THIS WILL BRING A PERIOD OF IFR/MVFR HEAVY RAIN IN THUNDERSTORMS WITH MVFR CIGS LIKELY AS WELL. WINDS WILL BE SOUTHERLY TODAY AROUND 12KTS...BECOME WEST TOWARD MORNING. SCATTERED TO ISOLATED SHOWERS AND STORMS REMAIN A THREAT UNTIL SATURDAY MORNING AROUND 15Z...BUT COVERAGE. AFTER STORMS MOVE OUT OF THE AREA OVERNIGHT...A MOIST AIR MASS IN PLACE IS LIKELY TO PRODUCE MVFR CIGS AND VISIBILITY THROUGH LATE SATURDAY MORNING. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...ERVIN SHORT TERM...ERVIN LONG TERM...ERVIN AVIATION...RP KINNEY
AREA FORECAST DISCUSSION
NWS WICHITA KS
256 PM CDT FRI AUG 29 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 256 PM CDT FRI AUG 29 2014 MODERATE INSTABILITY UNDER UPPER TROF ACROSS CENTRAL AND EASTERN KANSAS WILL SUPPORT SCATTERED DIURNAL CONVECTION LATE THIS AFTERNOON/EVENING. VISIBLE SATELLITE SHOWED AGITATED CU FIELD JUST WEST OF WICHITA METRO WITH CONVECTIVE DEVELOPMENT IN RENO COUNTY SINCE 1930Z. THE RUC AND HRRR WHERE SUGGESTIVE OF CONVECTIVE DEVELOPMENT ALONG/JUST WEST OF THE TURNPIKE CORRIDOR BEFORE SHIFTING CHANCES FURTHER EAST THRU THE EVENING. THIS IS HANDLED FAIRLY WELL IN THE GOING FORECAST. OTHERWISE THE WEEKEND LOOKS TO BEGIN ON A WARM BUT DRY NOTE FOR MOST OF THE AREA ON SATURDAY AS THE UPPER TROF MOVES SLOWLY EAST AWAY FROM THE AREA. HOWEVER THE LATTER PART OF THE HOLIDAY WEEKEND LOOKS A BIT MORE VOLATILE AS INCREASING WESTERLY FLOW ALOFT OVER THE PACIFIC MOVES ACROSS THE WESTERN CONUS WITH THE DEVELOPMENT OF A PROGRESSIVE UPPER TROF MOVING FROM THE CENTRAL/NORTHERN ROCKIES ACROSS THE PLAINS BY LATE SUNDAY. A MODERATE TO VERY UNSTABLE AIRMASS WILL DEVELOP AHEAD OF THE ASSOCIATED SURFACE DRYLINE AND COLD FRONT LATE SUNDAY AFTERNOON AND EVENING ACROSS CENTRAL KANSAS. DIURNAL SURFACE BASED CONVECTION WILL LIKELY BE SUPPRESSED BY A STOUT CAPPING INVERSION UNTIL VERY LATE IN THE AFTERNOON OR PERHAPS EARLY EVENING ON SUNDAY. HOWEVER THE FORCING FOR ASCENT SHOULD BE MORE THAN SUFFICIENT ALONG THE FRONT WITH DEEP LAYER SHEAR SUPPORTIVE OF A SEVERE CONVECTIVE EPISODE SUNDAY EVENING INTO PART OF SUNDAY NIGHT. WHILE THIS COMPLEX WILL LIKELY EXIT STAGE RIGHT BY MONDAY MORNING...THE SURFACE FRONT IS EXPECTED TO LAY OUT ACROSS SOUTH CENTRAL INTO EASTERN KANSAS DURING THE DAY. THE COMBINATION OF DIURNAL HEATING AND A TRAILING SHORTWAVE ALOFT MIGRATING EAST ACROSS THE AREA SHOULD RESULT IN RENEWED CONVECTION BY LATE MONDAY. MODERATE TO STRONG INSTABILITY AND SHEAR COULD ALSO GIVE RISE TO ANOTHER ROUND OF SEVERE STORMS. DARMOFAL .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 256 PM CDT FRI AUG 29 2014 PLAN TO MAKE LITTLE CHANGES TO THE OUTER PERIODS OF THE FORECAST...WITH CHANCES FOR CONVECTION WANING AND TEMPERATURES GRADUALLY WARMING WITH GEOPOTENTIAL HEIGHT RISES EXPECTED AS THE UPPER RIDGE BUILDS IN ACROSS THE AREA AGAIN DURING THE WEEK. KED && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1219 PM CDT FRI AUG 29 2014 AS WEAK WIND SHIFT AND ASSOCIATED UPPER TROUGH MOVE ACROSS THE AREA TODAY...THINKING ISOLATED TO WIDELY SCATTERED SHOWERS/THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING...MAINLY EAST OF I-135. FOR NOW INCLUDED VCSH AT ICT-CNU AFTER 20Z. OTHERWISE...THREAT SHOULD EXIT ICT BY 00Z...AND CNU BY 06Z. ADK && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 66 92 69 95 / 20 0 10 10 HUTCHINSON 63 92 69 96 / 20 0 10 10 NEWTON 65 91 69 95 / 20 0 10 10 ELDORADO 65 91 68 94 / 30 10 10 10 WINFIELD-KWLD 67 92 69 95 / 30 10 10 10 RUSSELL 63 92 69 96 / 10 10 20 30 GREAT BEND 62 92 69 97 / 10 10 20 20 SALINA 64 93 69 97 / 20 0 20 20 MCPHERSON 64 92 69 96 / 20 0 10 20 COFFEYVILLE 69 91 69 94 / 40 20 20 10 CHANUTE 67 90 68 93 / 40 20 20 10 IOLA 67 89 68 93 / 40 20 10 10 PARSONS-KPPF 68 90 69 94 / 40 20 20 10 && .ICT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1209 PM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT FRI AUG 29 2014 RATHER UGLY MORNING OUT THERE IN TERMS OF AVIATION...WITH PLENTIFUL AMOUNTS OF LOW CIGS AND FOG OUT AHEAD OF A WARM FRONT THAT WAS STARTING TO MAKE PROGRESS NORTH INTO MN AND AT 3 AM WAS NEAR THE I-90 CORRIDOR. BESIDE THE LOW CLOUDS...ISENTROPIC LIFT AND ELEVATED INSTABILITY ADVECTION ASSOCIATED WITH A MODEST 20-30 KT SWRLY LLJ HAS ALLOWED FOR AN AREA SHOWERS/THUNDERSTORMS TO MOVE NNE ACROSS THE AREA. THE HRRR HAS HAD A GOOD HANDEL ON THIS ACTIVITY OVERNIGHT...AND FOLLOWED IT FAIRLY CLOSELY TO TIME THIS MORNINGS BATCH OF ACTIVITY THROUGH THE AREA. THIS BATCH OF RAIN LOOKS TO BE MOSTLY NORTH OF THE MPX AREA BY 15Z...WITH A BRIEF BREAK IN PRECIP EXPECTED UNTIL THUNDERSTORMS GET GOING AGAIN LATER IN THE AFTERNOON. FOR THE AFTERNOON...WE WILL BE DEALING WITH A RATHER MESSY SFC PATTERN AS THE MESO LOW CURRENTLY NEAR SIOUX FALLS WASHES OUT OVER MN AS IT GETS ABSORBED BY THE MAIN COLD FRONT...WHICH WAS STILL BACK ACROSS WRN NODAK. BIGGEST CHANGE SEEN FROM THE 28.12 TO THE 29.00 MODEL RUNS WAS A WHOLESALE SLOWING OF THE FRONT/SFC TROUGH ACROSS THE AREA. THIS HAS RESULTED IN HIGHER POPS BEING PUSHED BACK WEST THIS AFTERNOON...AS WHAT WAS LOOKING LIKE WAS MAINLY GOING TO BE A SHOW FOR AREAS ALONG/EAST OF I-35 IS NOW MORE OF AN ALONG/EAST OF A ST. CLOUD TO FAIRMONT LINE. THE HI-RES MODELS THAT LOOK TO ADHERE TO WHAT IS SEEN FORCING WISE WITH THE DETERMINISTIC MODELS THE BEST ARE THE 29.00 NMM AND MPX WRFS...WHICH BOTH SHOW STORMS FORMING WEST OF THE TWIN CITIES BETWEEN 19-21Z AND MOVING EAST FROM THERE AS A BROKEN LINE OF STORMS. ONE THING THAT HAS NOT CHANGED...IS THE MOST WIDESPREAD RAIN/HIGHEST AMOUNTS LOOK TO FALL ACROSS SE MN/WRN WI AS THE AFTERNOON ACTIVITY TO THE WEST OF I-35 CONGEALS INTO A BROADER MASS EAST OF I-35. STILL NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER TODAY EITHER...AS CLOUD COVER LOOKS TO BE EXTENSIVE...WHICH WILL LIMIT THE DEGREE OF DESTABILIZATION WE SEE BY THE AFTERNOON. IN ADDITION...MID LEVEL LAPSE RATES WILL REMAIN RATHER WEAK...FURTHER POINTING TO INSTABILITY SOMEWHAT LACKING WHEN IT COMES TO THE SEVERE WEATHER POTENTIAL. BESIDE THE INSTABILITY...THE SFC PATTERN LOOKS TO BE RATHER DIFFUSE...WITH NO CLEAR FOCUS EXISTING FOR THUNDERSTORM ACTIVITY /SEE FRONT SUNDAY FOR A CLEAR FOCUS FOR THUNDERSTORM DEVELOPMENT/. WITH THAT SAID...BULK SHEAR WILL BE UP IN THE 30-40 KT RANGE AHEAD OF THE SFC TROUGH...SUFFICIENT ENOUGH TO ALLOW FOR A MULTI-CELL CLUSTER OR TWO TO PULSE UP ENOUGH TO POSE AN ISOLATED WIND/HAIL THREAT TODAY. FOR HIGHS TODAY...THERE IS ADMITTEDLY SOME BUST POTENTIAL WITH THE CURRENT FORECAST OF HIGHS IN THE 70S AS THAT IS PREDICATED ON CLOUD COVER BEING DOMINATE TODAY. IF WE INSTEAD GET SOME DECENT SUN BEFORE STORMS DEVELOP THIS AFTERNOON...THEN HIGHS IN THE LOWER/MID 80S WILL BE MORE COMMON. FOR TONIGHT...SHOWER AND THUNDERSTORM ACTIVITY LOOKS SLOWLY CLEAR OUT TO THE EAST...WITH TO MUCH LEFT OUTSIDE OF SOME DRIZZLE IN WRN WI BY 12Z SATURDAY. HOWEVER...THE SFC THROUGH/FRONT WILL BE VERY SLOW IN WORKING ACROSS THE AREA...WITH PLENTIFUL LOW LEVEL MOISTURE LOOKING TO HANG AROUND MOST OF THE NIGHT. THIS SHOULD ALLOW FOR ANOTHER ROUND OF LOW STRATUS AND FOG TO EXPAND ACROSS THE AREA TONIGHT...WHICH IN TURN WILL HELP KEEP LOWS UP MAINLY IN THE MID/UPPER 60S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 338 AM CDT FRI AUG 29 2014 THE MAIN STORY IN THE EXTENDED IS THE SYSTEM EXPECTED SUNDAY AFTERNOON AND SUNDAY NIGHT WITH THE HIGH LIKELIHOOD OF WIDESPREAD THUNDERSTORMS AND THE POTENTIAL FOR SEVERE WEATHER. THE RAIN SHOULD CLEAR EARLY ON LABOR DAY...LEAVING MAINLY DRY WEATHER ACROSS THE FORECAST AREA THROUGH AT LEAST MID WEEK. THE TROUGH EXPECTED TO MOVE ACROSS THE NORTHERN CONUS SUN-MON AND BRING WIDESPREAD THUNDERSTORMS TO THE NATION`S MID SECTION IS ALREADY AN ESTABLISHED CIRCULATION WITH A WELL-DEFINED PV FEATURE IN THE GULF OF ALASKA THIS MORNING. THE TROUGH WILL DIG SOUTHEAST OVER THE NEXT 48 HOURS AND DEVELOP MORE OF A NEGATIVE TILT BEFORE LIFTING NORTH TOWARD HUDSON BAY MONDAY NIGHT. THE JET STRUCTURE SUPPORTS WIDESPREAD UPPER DIVERGENCE AND 500MB 12-HR HEIGHT FALLS BETWEEN 80-100M SLIP ACROSS NORTHERN MN SUNDAY NIGHT. LOWER IN THE ATMOSPHERE...850-700MB FGEN INCREASES IN WESTERN MN NEAR OR JUST AFTER 18Z ON SUNDAY. THE BOUNDARY MAKES GRADUAL PROGRESS TO THE EAST FROM 18Z SUNDAY UNTIL 12Z MONDAY. A SLOWLY DEEPENING AND EASTWARD-MOVING SURFACE CYCLONE PRODUCES 4-6MB 6-HR MSLP PRESSURE FALLS ACROSS THE FORECAST AREA ON SUNDAY. CONVECTIVE INITIATION SHOULD NOT BE A PROBLEM...IN FACT...STORMS SHOULD ALREADY BE ONGOING IN THE EASTERN DAKOTAS SATURDAY MORNING. ELEVATED CONVECTION SHOULD TRANSITION TO MORE SURFACE BASED CONVECTION WITH HEATING AND THE LIKELY ESTABLISHMENT OF LARGE LINE SEGMENTS OR CLUSTERS OF THUNDERSTORMS DUE TO THE LARGE-SCALE FORCING. THE DEEP LAYER SHEAR SHOULD BE GOOD ENOUGH TO ORGANIZE STORMS INTO MULTI-CELL WITH EMBEDDED SUPERCELLS /EVEN IF THEY EXIST IN LINES/. THE INSTABILITY SHOULD BE SUFFICIENT TO SUPPORT STRONG UPDRAFTS. IT LOOKS PRIMARILY LIKE A WIND AND HAIL THREAT IN THE AFTERNOON AND EVENING HOURS ACROSS MN. BOTH THE NAM AND GFS HAVE 0-3KM SHEAR ON THE ORDER OF 25-40KTS FROM 18Z-06Z ACROSS THE FORECAST AREA. THE SEVERE THREAT DIMINISHES IN WI GIVEN THE LOSS OF INSTABILITY SUNDAY NIGHT AND QUICKLY NORTHWARD LIFTING SURFACE LOW. BEYOND THE WEEKEND...THE TROUGH FLATTENS OUT AND WE`RE LEFT WITH A RELATIVELY DRY AND COOL WESTERLY FLOW PATTERN THROUGH AT LEAST MID WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1153 AM CDT FRI AUG 29 2014 TWO AREAS OF CONVECTION ACROSS THE PLAINS AND UPPER MIDWEST WILL LEAD TO OCCASIONAL SHRA/TSRA FOR MOST OF MPX TAF AREA THRU THE AFTN WITH THE EXCEPTION OF KAXN WHERE THE SFC TROUGH HAS MOVED THRU AS OF 17Z. AN UPPER LOW WHICH IS CURRENTLY NEAR KOMA WILL LIKELY HOLD THE SFC TROUGH ACROSS CENTRAL MN THIS AFTN AS THE UPPER LOW MOVES NE ACROSS NC IA/SE MN. THIS WILL LEAD TO THE CONTINUATION OF SHRA/TSRA FROM KRWF TO KSTC...EASTWARD TOWARD EC MN/WC WI THRU THE AFTN. TIMING OF HEAVIER TSRA WILL BE PROBLEMATIC SO WILL CONTINUE WITH TEMPO PERIOD FOR MOST AREAS WITH 2SM +TSRA. ALTHOUGH VSBYS WILL BE REDUCED TO LESS THAN 1SM AT TIMES...IT SHOULD BE VERY SHORT AND LAST 5 TO 10 MINS. MORE MODERATE SHRA/TSRA WILL MEAN PERIODS OF 2-3SM WITH A PREDOMINATE 4-6SM IN LIGHTER ACTIVITY. MOST OF THE SHRA/TSRA SHOULD MOVE OFF INTO WC WI BY 23-01Z...WITH IFR/LIFR CIGS/VSBYS DEVELOPING IN THE WAKE OF THIS SYSTEM. WINDS WILL BE FROM THE S/SW AHEAD OF THE SFC TROUGH...WITH A WEAK WEST/NW FLOW BEHIND IT THRU THIS EVENING. A MORE NW/NNW IS EXPECTED BY SATURDAY MORNING ARND 5-10 KTS. KMSP... TWO AREAS OF CONVECTION WILL LEAD TO A CONTINUED TREND OF SHRA AND EMBEDDED TSRA THRU THE AFTN. NOT UNTIL THE SFC TROUGH MOVES EAST OF THE AREA ALONG WITH THE UPPER LOW...WILL CHC/S OF SHRA/TSRA DIMINISH. TIMING OF THE HEAVIER TSRA REMAINS QUESTIONABLE...SO WILL CONTINUE WITH A TEMPO OF 2SM +TSRA DURING THE AFTN. A BRIEF PERIOD OF VSBYS LESS THAN 1SM IS LIKELY...BUT SHOULD ONLY LAST 5 TO 10 MINS. MOST OF THE STEADIER SHRA SHOULD MOVE OUT OF MSP TERMINAL AREA BY 1-3Z WITH IFR/LIFR CIGS/VSBYS DEVELOPING OVERNIGHT. VFR CONDS ARE NOT EXPECTED UNTIL AFT 18Z ON SATURDAY. WINDS WILL BE GENERALLY FROM THE SW THIS AFTN ARND 5-10 KTS...THEN WEAKEN AND VEER WEST TO NORTHWEST OVERNIGHT. /OUTLOOK FOR KMSP/ SAT AFTN...VFR. WIND NNE AT 5-10 KTS. SUN...VFR WITH MVFR/TSRA LATE. WINDS SSE AT 10-20 KTS. MON...MVFR/TSRA ENDING EARLY. VFR BY AFTN WINDS W 10-15KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...JLT
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
401 PM CDT Fri Aug 29 2014 .DISCUSSION... Issued at 401 PM CDT FRI AUG 29 2014 Out of the gate this afternoon...first round of convection continuing to track east-northeast as initial shot of vorticity and pressure advection associated with inbound upper wave slides east across the region. Upstream behind this afternoon/s activity...skies have cleared and weak destabilization has occurred with latest SPC mesoanalysis suggesting anywhere between 1000-1500 J/Kg of MLCAPE exists across eastern KS and western MO. Heading into the late afternoon...main concern is for redeveloping convection as next piece of shortwave energy and associated vorticity slides over the area. As this occurs...long-lived frontal boundary which has been in place across the central Plains in recent days should slowly slide across the region which should also help with possible redevelopment. Fcst models have been playing this card quite well with latest HRRR high- res data supporting renewed convection across eastern KS this afternoon. For now...have advertised chc pops pretty much across the western 2/3rds of the fcst area...before gradually spreading them east during the early overnight period. In terms of severe threats...latest mesoanalysis shows fairly weak shear aloft. This along with a DCAPE min/trough across our region should largely prevent widespread severe. That said though...a few strong downbursts cannot be ruled out if convection actually does develop. Main front to slide through the forecast area tonight as discussed above. This should result in a gradual decrease in storm coverage from west to east during the early morning hrs if storms do in fact develop. Overnight lows tonight will largely reside in the middle to upper 60s. By all accounts...upcoming holiday weekend shaping up to be beautiful...at least early on that is as region will reside in a post frontal airmass both Saturday and Sunday. Despite the fropa tonight...limited to no cooling seeing in the 850-mb temp field thus expect high temps in the mid to upper 80s on Saturday...and potentially into the lower to middle 90s on Sunday as warm air advection increases ahead of next incoming wave/front. Much more interesting weather by Sunday night/early Monday as well advertised longwave trough continues to dig along the Front Range. As this occurs...cyclogenesis expected across the northern Plains with strengthening future then expected to quickly exit into the upper Miss Vly/western Great Lakes region by early Monday. The end result for our area will be a slowly progressing cold front which will begin sliding south during this period...with increasing chances for rain from Sunday night through the Tuesday time frame. Main issue seen from this vantage point is that this feature will likely stall somewhere across central Missouri as it begins to interact with stout sfc ridging in place across the lwr Miss Vly and southern Plains. A severe wx concern initially Sunday night may quickly morph into a hydro concern as continued moisture advection resulting from a strengthening low-level jet of 2-3 standard deviations above normal ascends the stalled feature and cloud layer winds remain parallel to the front. Will have to maintain vigilance with this feature as many locations across our northwestern zones have received heavy rainfall in recent days. If severe wx were to develop Sunday night...bulk shear vectors orientation parallel to the incoming front will likely support multicell type storm morphologies...with high winds winds posing the biggest threat before concerns change over to possible heavy rain. That said...better frontal convergence for forced ascent will likely remain north of our fcst area which could ultimately limit the severe threat for our region. In any event...both flooding and possible severe pose a risk as seen this afternoon and will maintain mention in the HWO product for now. Beyond this...returning southerly flow will finally lift the front north across the region with dry weather returning in its wake by midweek. With zonal flow expected to dominate across the lower 48...temps through the conclusion of the period should remain near or slightly above normal. && .AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon) Issued at 1227 PM CDT FRI AUG 29 2014 Complicated fcst this afternoon as large scale upper trough and associated cold front will move through the area this afternoon/evening. That said...latest radar trends showing a decent swath of rain inbound to MCI with upstream obs over eastern KS supporting a tempo IFR mention out of the gate. As this activity clears to the north by 20z or so...attention then shifts to areas upstream which are now destabilizing thanks to mostly clear skies. As result...expect renewed shwr/storm activity later this afternoon with a second tempo group added at all sites to account for this possibility. Skies to slowly clear from west to east overnight which should give rise to developing VSBY and low CIG restrictions. For now...IFR restrictions offered at STJ with MVFR elsewhere. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...32 DISCUSSION...32 AVIATION...32
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1228 PM CDT Fri Aug 29 2014 .UPDATE... Issued at 1012 AM CDT FRI AUG 29 2014 Quick update this morning to account for latest radar and satellite trends. Fairly potent upper-level wave inbound this morning as seen on latest water vapor imagery. Ahead of this feature...upper- level pressure along the 1.5 PVU surface showing a nice "treble clef" signature with latest RUC analysis showing the trop undulation down to almost 500-mb...not bad for this time of year! Pressure advection in advance of this feature combined with decent upper divergence aloft should continue to support organized shwrs and thunderstorms. As this feature continues sliding east this morning...expect a gradual increase in precip chances from west to east which should result in very beneficial rainfall for a good portion of the area. In general...QPF totals will likely range from a quarter to half inch...with localized higher amounts possible with thunderstorm activity. Pop/wx grids updated to reflect a slightly delayed arrival time...but overall fcst trends remain unchanged. && .SHORT TERM...(Today through Sunday) Issued at 326 AM CDT FRI AUG 29 2014 For today, areas of scattered thunderstorms will continue to develop along and ahead of an eastward-moving shortwave trough, resulting in slowly increasing chances of precipitation this morning into the evening across the CWA. The best chance of storms will spread from early afternoon across eastern KS and far western MO to late evening in central MO. Afternoon temperatures will be held down by clouds and precipitation, keeping highs mainly in the 80s and the highest readings in central MO where storms will be later to arrive. Not much instability is expected to develop today with clouds arriving early and temperatures aloft and no real significant temperature perturbation along the trough to increase lapse rates, so do not expect much of a strong/severe storm threat this afternoon or this evening. However, if areas of central MO see a few peeks of sun through early afternoon, an isolated more robust storm could develop and could produce briefly gusty winds. Precipitation will generally clear out from northwest to southeast on Friday night, but may linger into Saturday across portions of central MO as a second weak shortwave trough rides up over central MO, especially if the weak surface boundary associated with today`s shortwave trough can stall over the region and support convective initiation on Saturday. High temperatures should be several degrees warmer for Saturday and especially Sunday as skies clear, southerly surface flow returns, and 850 hPa temperatures remain in the 18 to 21 C range. The next round of thunderstorms is expected to be a bit more robust Sunday night into early Monday morning along a southeastward moving cold front. General model consensus brings the front through the CWA between midnight and 9 AM Monday morning, although timing could change a bit. MUCAPE values in the 1000-2000 J/kg range and bulk shear values as high as 40 kts could support organized, potentially strong multicell storms especially across northwest MO. Heavy rain is also a threat with PWATs climbing to around 2 inches and bulk shear vectors orienting parallel to the front to support training storms. The overall severe threat will depend on timing of frontal passage as storms should become elevated with time and instability will decrease, but is expected mainly across northwest and northern MO where upper-level forcing and flow is a bit stronger. .LONG TERM...(Monday through Thursday) Issued at 326 AM CDT FRI AUG 29 2014 A complex of showers and thunderstorms will likely be ongoing over portions of the forecast area Monday morning as a cold front settles into northwest Missouri. While not an optimal diurnal time for severe weather with only modest instability forecast, will need to monitor potential as dynamics from the large upper trough over the northern tier of the country will yield moderate shear in advance of the cold front. The upper trough will gradually deamplify, leaving the surface cold front largely stationary Monday into Tuesday across the northern half of the CWA. Periodic thunderstorm chances will remain possible through Tuesday night as the region remains on the southern periphery of strong upper dynamics and associated embedded shortwave troughs traversing the area. A few storms may be strong with moderate shear and instability, especially during the afternoon and evening hours. With the boundary layer winds expected to remain weak, the primary threat would be brief periods of damaging wind gusts and hail to quarter-size. Pinpointing the timing and specific locations of highest precipitation potential remains challenging at this stage with convective details that will play some role in frontal position and windows of strongest ascent both unresolved. The surface boundary is expected to retreat northward as a warm front by Wednesday as heights begin to rise across the region. Only a slight chance of thunderstorms is anticipated on Wednesday, with dry conditions for the remainder of the work week. Likewise, temperatures will return to above normal readings, with afternoon highs in the upper 80s to lower 90s. && .AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon) Issued at 1227 PM CDT FRI AUG 29 2014 Complicated fcst this afternoon as large scale upper trough and associated cold front will move through the area this afternoon/evening. That said...latest radar trends showing a decent swath of rain inbound to MCI with upstream obs over eastern KS supporting a tempo IFR mention out of the gate. As this activity clears to the north by 20z or so...attention then shifts to areas upstream which are now destabilizing thanks to mostly clear skies. As result...expect renewed shwr/storm activity later this afternoon with a second tempo group added at all sites to account for this possibility. Skies to slowly clear from west to east overnight which should give rise to developing VSBY and low CIG restrictions. For now...IFR restrictions offered at STJ with MVFR elsewhere. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...32 SHORT TERM...Laflin LONG TERM...Blair AVIATION...32
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
238 PM CDT FRI AUG 29 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 238 PM CDT FRI AUG 29 2014 THE MAIN FORECAST CHALLENGE REMAINS A MINIMAL THREAT FOR PRECIPITATION THIS EVENING. FOR THIS EVENING AND THE OVERNIGHT...COMPACT PV ANOMALY OVER SE NEBRASKA WILL CONTINUE TO THE EAST NORTHEAST WHILE THE NEXT DISTURBANCE CURRENTLY ENTERING THE WESTERN DAKOTAS PUSHES EAST INTO THE REGION. SHOWERS AND STORMS WILL EXIT NORTH CENTRAL NEBRASKA WHILE ADDITIONAL STORMS FORM ACROSS THE NORTHWEST WITH THE APPROACH OF THE SECOND DISTURBANCE. PROXIMITY SOUNDINGS ACROSS THE AREA SHOW SIGNIFICANTLY LESS MOISTURE AS COMPARED TO A DAY OR TWO AGO. SHEAR IS LIMITED AT BEST IN A LOW CAPE ENVIRONMENT AS WELL...SO ISOLATED PULSE STORMS WOULD BE ANTICIPATED AT BEST. WILL CARRY A SLIGHT CHANCE MENTION ACROSS THE SANDHILLS AND NORTH CENTRAL NEBRASKA THIS EVENING...BUT WITH THE COOLING...STORMS SHOULD BE OVER BY 03-04Z. WITH DRY AIR ALOFT PUSHING IN FROM THE WEST...BUT A RELATIVELY MOIST BL...FOG MAY BE A CONCERN FOR OUR EAST AND IN FAVORED RIVER VALLEYS. WILL INTRODUCE PATCHY WORDING IN THE FORECAST FOR NOW AROUND THE DAWN HOURS. TRANSITORY SHORTWAVE RIDGING TO BUILD ACROSS THE NORTHERN AND CENTRAL PLAINS ON SATURDAY. WITH AN OVERALL LACK OF KINEMATIC FORCING AND A DRIER AIRMASS IN PLACE...STORMS AND/OR SHOWERS ARE NOT ANTICIPATED THROUGH 00Z SUNDAY. AFTER PLEASANTLY COOL LOWS IN THE 50S SATURDAY MORNING...HIGHS SHOULD REBOUND INTO THE 80S FOR MOST LOCATIONS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 238 PM CDT FRI AUG 29 2014 SATURDAY NIGHT THROUGH MONDAY... A LEAD DISTURBANCE WILL EMERGE ONTO THE PLAINS REGION SATURDAY NIGHT. MOISTURE WILL REMAIN SOMEWHAT LIMITED...BUT WILL BE OFFSET BY A DEVELOPING LOW LEVEL JET. COVERAGE SHOULD MOSTLY BE ISOLATED AND HAVE A SLIGHT CHANCE OVERNIGHT...EXCEPT NEAR 30 PERCENT CHANCE IN THE NORTHEAST. ON SUNDAY...UPPER TROUGH WILL MOVE INTO WESTERN NEBRASKA AS A COLD FRONT MOVES SOUTHEAST. THE COLD FRONT IS FORECAST BY MODELS TO BE SLIGHTLY FASTER AND HAVE LOWERED POPS MOST AREAS TO 20 TO 40 PERCENT. AREAS EAST OF ONEILL THROUGH STOCKVILLE WILL HAVE A 40 TO 50 POP SUNDAY AFTERNOON/EARLY EVENING WHERE STRONG LIFT ALONG THE FRONT COULD PRODUCE A FEW STRONG TO SEVERE STORMS. ON MONDAY...FLOW WILL REMAIN FAIRLY ZONAL. SOMEWHAT DRIER AIR WILL WORK INTO WRN NEBR AS DEWPOINTS RANGE FROM THE MID 40S TO LOW 50S WEST TO THE LOWER TO MID 50S SOUTHEAST. A WEAK DISTURBANCE WILL PRODUCE CONVECTION FROM EASTERN WY INTO WRN SOUTH DAKOTA. A FEW STORMS MAY MOVE INTO THE PANHANDLE AND FAR NWRN FORECAST AREA BY LATE AFTERNOON. MONDAY NIGHT THROUGH FRIDAY... A DISTURBANCE IS INDICATED FROM EASTERN MT INTO EASTERN WYOMING MONDAY AFTERNOON...WHICH WILL MOVE ACROSS THE NRN AND CNTRL PLAINS MONDAY NIGHT. MOISTURE RETURN WILL BE VERY LIMITED AND MAINTAINING ONLY SLIGHT CHANCE POPS FOR MONDAY NIGHT LOOKS APPROPRIATE. UPPER FLOW ACROSS THE CENTRAL PLAINS WILL BE ZONAL ON TUESDAY AND GRADUALLY TRANSITION TO SOUTHWEST FLOW BY WEDNESDAY NIGHT. THIS IN RESPONSE TO AN UPPER TROUGH DIGGING INTO THE PACIFIC NORTHWEST AND AN UPPER RIDGE PERSISTING OVER THE TENNESSEE VALLEY. HIGHS WILL WARM FROM THE MID 80S TUESDAY TO THE MID/UPPER 80S WEDNESDAY. BY THURSDAY...SURFACE LOW PRESSURE WILL DEEPEN IN WESTERN KANSAS AS CANADIAN HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS. THIS WILL SETTLE A COLD FRONT INTO SOUTHERN NEBRASKA DURING THE DAY WITH CHANCES FOR THUNDERSTORMS THURSDAY INTO FRIDAY. THE 12Z GFS HAS COME INTO FAIRLY GOOD AGREEMENT WITH THE ECMWF WITH POPS APPROPRIATELY ADDED IN THURSDAY THROUGH FRIDAY. AS CANADIAN HIGH PRESSURE BUILD IN THURSDAY NIGHT...HIGHS FRIDAY TO COOL TO THE MID 70S TO NEAR 80. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 102 PM CDT FRI AUG 29 2014 FOR THE 18Z TAF ISSUANCE...STORMS WILL ONCE AGAIN BE POSSIBLE FOR MOST AREA TERMINALS THIS AFTERNOON AND EVENING. ATTM...THE LATEST GUIDANCE INDICATES THE HIGHEST PROBABILITY OF STORMS ACROSS CENTRAL AND NORTHERN TERMINALS. CONFIDENCE IS NOT ENOUGH TO WARRANT A TSRA MENTION AT KLBF THIS EVENING. AT KVTN...DEBATED WHETHER TO GO WITH VCTS OR ACTUAL TSRA...BUT EVENTUALLY SIDED WITH THE LATEST HRRR WHICH INDICATES STORMS AFTER 00Z. ERRATIC WIND AND MODERATE RAINFALL WOULD ACCOMPANY ANY STORM THAT DEVELOPS. OTHERWISE ONGOING STORMS ACROSS FAR NORTH CENTRAL NEBRASKA WILL CONTINUE THIS AFTERNOON. MVFR OR LOWER RESTRICTIONS CAN BE EXPECTED AT KONL WHEN IMPACTED BY A STORM. FOG MAY BE A CONCERN TOMORROW MORNING...GUIDANCE IS SUGGESTING REDUCED VISIBILITY AT BOTH KVTN AND KLBF. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JACOBS LONG TERM...ROBERG AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
102 PM CDT FRI AUG 29 2014 .SYNOPSIS... ISSUED AT 359 AM CDT FRI AUG 29 2014 H5 ANALYSIS FROM EARLIER THIS EVENING HAS A VERY ACTIVE NORTHERN STREAM ACROSS CANADA AND ALASKA WITH SEVERAL UPPER LEVEL LOWS PRESENT. CLOSED LOWS WERE LOCATED OVER THE GULF OF ALASKA...NORTHERN PORTIONS OF HUDSON BAY...THE CANADIAN MARITIMES...AS WELL AS OFF THE COAST OF NRN ALASKA. ACROSS THE CONUS...HIGH PRESSURE WAS PRESENT OFF THE COAST OF SRN CA...AS WELL AS THE FAR SERN CONUS. CLOSER TO WESTERN AND NORTH CENTRAL NEBRASKA...A TROUGH OF LOW PRESSURE EXTENDED FROM CENTRAL PORTIONS OF THE DAKOTAS...SWD INTO THE TX PANHANDLE. UPSTREAM OF THIS FEATURE...A NICE SHORTWAVE WAS PRESENT OVER SRN PORTIONS OF MT. RADAR IMAGERY ACROSS THE CENTRAL AND SRN PLAINS...HAS A NICE AREA OF SHOWERS AND THUNDERSTORMS EXTENDING FROM EASTERN KS INTO FAR EASTERN NEBRASKA THIS MORNING WITH ALL ACTIVITY OFF TO THE EAST OF THE FORECAST AREA. SKIES HAVE GRADUALLY CLEARED OVERNIGHT WEST OF A LINE FROM ATKINSON TO BROKEN BOW WHERE DRIER MID LEVEL AIR HAS PUSHED INTO CENTRAL AND WESTERN NEBRASKA. TEMPERATURES AS OF 3 AM CDT...RANGED FROM 54 AT OGALLALA TO 65 AT BROKEN BOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT FRI AUG 29 2014 FOR TODAY AND TONIGHT...THE MAIN FORECAST CHALLENGE IS A MINIMAL THREAT FOR PRECIPITATION THIS AFTERNOON AND EARLY THIS EVENING. FOR TODAY...SKIES WILL CONTINUE TO CLEAR THIS MORNING IN THE EASTERN CWA AS THE UPPER LEVEL TROUGH OF LOW PRESSURE SHIFTS EAST INTO THE MISSOURI VALLEY. FURTHER WEST...SKIES WILL BEGIN TO CLOUD UP THIS AFTERNOON AS THE BEFORE MENTIONED DISTURBANCE OVER SRN MT APPROACHES THE NEBR PANHANDLE. WITH HEATING THIS AFTERNOON...LOW AND MID LEVEL LAPSE RATES WILL STEEPEN SIGNIFICANTLY...INCREASING THE THREAT FOR AN ISOLATED THUNDERSTORM OR TWO. DECIDED TO KEEP SHOWER COVERAGE TO A MINIMUM AS AVAILABLE MOISTURE IS SIGNIFICANTLY LESS THAN WHAT WE HAD A COUPLE OF DAYS AGO. THIS IS EVIDENT IN PWATS OF 0.75 TO 1.00 INCH VS. THE 1.5 TO 2.0 INCH PWATS OF A COUPLE OF DAYS AGO. WE WILL BE IN A VERY WEAK SHEAR ENVIRONMENT AS WELL...SO STORMS WILL BE OF THE PULSE TYPE WITH SHORT DURATION EXPECTED. WITH COOLING THIS EVENING...THE THREAT FOR STORMS IS EXPECTED TO END QUICKLY BY 03Z. AFTER HIGHS TODAY IN THE LOWER TO MIDDLE 80S...DRIER AIR WILL PUSH INTO THE FORECAST AREA TONIGHT. THE COMBINATION OF DRIER AIR AND CLEARING SKIES WILL ALLOW LOWS TO BOTTOM OUT IN THE LOWER TO MIDDLE 50S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 359 AM CDT FRI AUG 29 2014 SATURDAY WILL SEE THE HIGH PLAINS BETWEEN SUBTLE DISTURBANCES WITH MODELS IN AGREEMENT WITH A LITTLE RIDGING OVERHEAD. THIS SHOULD AID IN LITTLE CLOUD COVER THROUGH THE DAY. MOS GUIDANCE HAS TEMPS WELL INTO THE 80S AND A FEW LOWER 90S. FORECAST IS ON THE CONSERVATIVE SIDE...GOING WITH THE LOWER GUIDANCE OR SLIGHTLY BELOW...CONSIDERING MOST AREAS HAVE RECEIVED AT LEAST A COUPLE OF INCHES THE PAST FEW DAYS AND THE GROUND WILL STILL BE DAMP. MEANWHILE EYES BEGIN TO FOCUS ON THE TROUGH MOVING INTO THE PAC NW. THIS TROUGH WILL PUSH ACROSS THE ROCKIES EARLY ON SUNDAY...AS A SFC COLD FRONT PUSHES ACROSS THE AREA. GOOD AGREEMENT WITH CAPE VALUES OF 2K TO 4K J/KG AND 40 TO 55 KTS OF SHEAR AHEAD OF THE FRONT. THE CONCERN IS WHERE THE FRONT WILL BE LOCATED AT PEAK HEAT. GENERAL MODEL BLEND IS ACROSS CENTRAL NEBRASKA...WITH THE EASTERN PORTIONS OF THE CWA TO SEE DEVELOPMENT. STEEP LAPSES RATE POST FRONT MAY BE ENOUGH FOR SOME ISOLD/SCT SHOWERS. ACTIVITY QUICKLY MOVES EAST SUNDAY NIGHT AND MODELS IN AGREEMENT ENDING PRECIP BY MIDNIGHT...AND FORECAST HAS GONE DRY OVERNIGHT. THIS WILL ALSO RESULT IN LESS CLOUD COVER AND COOL HIGH PRESSURE BUILDING IN FROM THE WEST. FORECAST FOLLOWS COOL GUIDANCE WITH TEMPS TRENDING COOLER. ANOTHER DISTURBANCE WILL MOVE ACROSS THE AREA MONDAY NIGHT WITH LOW POPS CONTINUED. THEN ZONAL FLOW WILL SLOWLY BECOME WEST SOUTHWESTERLY. MODELS KEEP MOISTURE PLUM TO THE SOUTH OF THE CWA...WITH MUCH OF THE WEEK EXPECTED TO BE DRY. TEMPS WILL BE ON A SLOW CLIMB. TOWARDS THE END OF THE WORK WEEK...A TROUGH WILL DIG IN ACROSS THE WESTERN COAST. THIS WILL CAUSE THE FLOW TO BECOME MORE SOUTHWESTERLY. WILL HAVE TO MONITOR AS THIS SET UP WILL LIKELY BRING A HIGHER CHANCE FOR POPS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 102 PM CDT FRI AUG 29 2014 FOR THE 18Z TAF ISSUANCE...STORMS WILL ONCE AGAIN BE POSSIBLE FOR MOST AREA TERMINALS THIS AFTERNOON AND EVENING. ATTM...THE LATEST GUIDANCE INDICATES THE HIGHEST PROBABILITY OF STORMS ACROSS CENTRAL AND NORTHERN TERMINALS. CONFIDENCE IS NOT ENOUGH TO WARRANT A TSRA MENTION AT KLBF THIS EVENING. AT KVTN...DEBATED WHETHER TO GO WITH VCTS OR ACTUAL TSRA...BUT EVENTUALLY SIDED WITH THE LATEST HRRR WHICH INDICATES STORMS AFTER 00Z. ERRATIC WIND AND MODERATE RAINFALL WOULD ACCOMPANY ANY STORM THAT DEVELOPS. OTHERWISE ONGOING STORMS ACROSS FAR NORTH CENTRAL NEBRASKA WILL CONTINUE THIS AFTERNOON. MVFR OR LOWER RESTRICTIONS CAN BE EXPECTED AT KONL WHEN IMPACTED BY A STORM. FOG MAY BE A CONCERN TOMORROW MORNING...GUIDANCE IS SUGGESTING REDUCED VISIBILITY AT BOTH KVTN AND KLBF. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...MASEK AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1258 PM CDT FRI AUG 29 2014 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 THE PRIMARY FORECAST CHALLENGES WILL BE IN REGARDS TO PCPN CHANCES TODAY INTO TONIGHT AND THEN TIMING THE NEXT ROUND OF CONVECTION SUNDAY INTO SUNDAY NIGHT. SOME SEVERE STORMS WILL BE POSSIBLE MAINLY FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING. MAIN FEATURES FROM THE UPPER AIR CHARTS LAST EVENING INCLUDED THE FOLLOWING. AT 300 MB A JET SEGMENT OF AROUND 70 KNOTS WAS PUNCHING NORTHEAST FROM SOUTHWEST KS. THIS WAS AHEAD OF A 500 MB TROUGH THAT STRETCHED FROM THE DAKOTAS DOWN INTO WEST TEXAS. 12 HOUR HEIGHT FALLS OF UP TO AROUND 40 METERS WERE NOTED AT AMARILLO AND DODGE CITY. DECENT MOISTURE WAS STILL IN PLACE AT 700 MB AND 850 MB AHEAD OF THE MID LEVEL TROUGH. THE KOAX SOUNDING WAS STILL FAIRLY MOIST WITH 1.70 PRECIPITABLE WATER. SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER SOUTHEAST SOUTH DAKOTA AND A COLD FRONT EXTENDING SOUTHWARD FROM THE LOW INTO WEST TEXAS. DEWPOINTS WERE IN THE 60S TO LOWER 70S. WATER VAPOR LOOP EARLY THIS MORNING SHOWED THAT THE TROUGH TO OUR WEST HAD MADE SOME EASTWARD PROGRESS SINCE LAST EVENING. IT SHOULD CONTINUE TO HAVE AN IMPACT ON US UNTIL A LITTLE AFTER MIDNIGHT TONIGHT. KEPT FAIRLY HIGH POPS GOING TODAY...SINCE WE SHOULD SEE REDEVELOPMENT THIS AFTERNOON WITH DAYTIME HEATING. FORECAST SOUNDINGS FROM THE 00Z NAM INDICATED ELEVATED INSTABILITY OF OVER 2000 J/KG BY AROUND NOON. RECENT RUNS OF THE RAP MODEL SHOW AN INCREASE IN PCPN COVERAGE AFTER 1 PM. HIGHS WILL BE MAINLY IN THE UPPER 70S AND LOWER 80S. LOWS TONIGHT SHOULD DROP TO THE LOWER AND MID 60S AS DRIER AIR WORKS ITS WAY IN FROM THE NORTHWEST BEHIND THE COLD FRONT. SOME PATCHY FOG COULD DEVELOP LATE TONIGHT...BUT OVERALL THE ATMOSPHERE WILL BE DRYING OUT. SATURDAY LOOKS LIKE A DECENT DAY WITH A FAIR AMOUNT OF SUNSHINE AND HIGHS IN THE 80S. CLOUDS WILL START TO INCREASE SATURDAY NIGHT... ESPECIALLY IN OUR FAR WESTERN ZONES. KEPT A SMALL CHANCE OF LATE NIGHT TSTMS IN NORTHEAST NEBRASKA. MODELS HAVE SOME TIMING DIFFERENCES FOR SUNDAY INTO SUNDAY NIGHT. KEPT SOME LOW POPS LATE SATURDAY NIGHT WEST OF A LINE FROM WAYNE TO COLUMBUS. 00Z RUNS OF THE NAM AND CANADIAN MODEL WERE A BIT SLOWER WITH DEVELOPMENT OF STORMS SUNDAY AFTERNOON. FOR NOW...BLENDED IN SOME OF THE GFS AND ECMWF WHICH SHOW SOME RAINFALL AMOUNTS OVER A QUARTER OF AN INCH SUNDAY AFTERNOON. IF THE NAM IS MORE CORRECT... THE SEVERE WEATHER POTENTIAL IS PROBABLY HIGHER SUNDAY EVENING THAN IF THE GFS AND ECMWF VERIFY BETTER. LOOK FOR HIGHS MAINLY IN THE 80S AND MAYBE NEAR 90 FOR PARTS OF SOUTHEAST NEBRASKA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 325 AM CDT FRI AUG 29 2014 TRENDED POPS DOWNWARD SUNDAY NIGHT FROM NORTHWEST TO SOUTHEAST AS THE SYSTEM MOVES THROUGH...BUT LINGERED A SLIGHT CHANCE OF TSTMS INTO MONDAY MORNING. A 500 MB LONGWAVE TROUGH AXIS WILL BE LOCATED OVER THE EASTERN ROCKIES AND WESTERN HIGH PLAINS AT THE BEGINNING OF THIS PERIOD. BY TUESDAY...THAT SHIFTS EAST OF OUR AREA AND THEN THE FLOW IS FAIRLY ZONAL ACROSS MID AMERICA INTO WEDNESDAY. LATER IN THE WEEK ANOTHER TROUGH WILL DIG INTO THE PACIFIC NORTHWEST...WITH OUR AREA UNDER THE INFLUENCE OF SOUTHWEST MID LEVEL FLOW. ALTHOUGH THUNDERSTORM CHANCES WILL NOT BE COMPLETELY ABSENT...NEXT WEEK SHOULD BE A LOT DRIER THAN THIS WEEK HAS BEEN. HIGHS WILL MODERATE FROM MAINLY 80S TO AROUND 90 AND LOWS WILL INCREASE FROM 60S TO AROUND 70 OR THE LOWER 70S. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1250 PM CDT FRI AUG 29 2014 SCATTERED CONVECTION IS LIKELY ACROSS EASTERN NEBRASKA THROUGH 00Z AS VIGOROUS UPPER WAVE OVER THE CENTRAL PLAINS MOVES EAST. MVFR CONDITIONS EXPECTED DURING THIS TIME FOLLOWED BY A PERIOD OF VFR THROUGH ABOUT 08Z. MVFR TO IFR CONDITIONS IN FOG AND CIGS EXPECTED AFTER 08Z THRU ABOUT 14Z WITH LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE IN PLACE. VFR CONDITIONS THEN DEVELOPING 14Z-18Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
355 PM EDT FRI AUG 29 2014 .SYNOPSIS... HIGH PRESSURE WILL BRING PLEASANT WEATHER TO OUR AREA TONIGHT THROUGH SATURDAY. A STORM SYSTEM MOVING THROUGH THE UPPER GREAT LAKES AND EASTERN CANADA WILL GIVE THE REGION SHOWERS AND THUNDERSTORMS LATE SATURDAY NIGHT AND SUNDAY. HIGH PRESSURE WILL PROVIDE PARTLY SUNNY SKIES AND WARM TEMPERATURES ON MONDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 4 PM UPDATE...UPPER LEVEL RIDGE WILL CREST OVER THE REGION TONIGHT AS SFC HIGH PRES RESIDES OVER EASTERN NEW ENGLAND. PARTLY CLOUDY SKIES ARE EXPECTED DUE TO SOME MID LEVEL CLOUDINESS. LATE TONIGHT DUE TO RADIATIONAL COOLING PATCHY VALLEY FOG IS LIKELY IN THE DELAWARE, SUSQUEHANNA AND CHEMUNG BASINS. OVERNIGHT LOWS WILL RANGE IN THE LOWER TO MIDDLE 50S. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... SATURDAY...UPPER LEVEL RIDGE AXIS WILL MOVE TO NEW ENGLAND AS AN UPPER LEVEL TROF DROPS INTO THE UPPER GREAT LAKES. SFC HIGH PRES OFF THE NEW ENGLAND COAST WILL PROVIDE A MODERATING S/SW FLOW. PARTLY SUNNY SKIES ARE EXPECTED WITH ANY CONVECTION HOLDING OFF UNTIL DARK. MAX TEMPS WILL RANGE IN THE MID 70S TO LOWER 80S WITH THE HIGHEST READINGS ALONG THE LAKE PLAIN AND CENTRAL SOUTHERN TIER. SATURDAY NIGHT/SUNDAY...UPPER LEVEL TROF WILL APPROACH THE REGION AS A LOW PRES SYSTEM DRAGS A WEAK SFC TROF THROUGH THE AREA ON SUNDAY. THE CHANCES FOR PRECIP WILL INCREASE LATE SATURDAY EVENING AS MID LEVEL SHORT WAVES START ROTATING THROUGH THE AREA IN THE SOUTHWEST UPPER LEVEL FLOW. BY DAYBREAK SUNDAY WILL HAVE LIKELY POPS ACROSS MUCH OF CENTRAL NEW YORK AND SLIGHT CHC/CHC NE PA. AS THIS BOUNDARY SLIDES THROUGH THE REGION WILL ADVERTISE LIKELY POPS FOR SHOWERS AND THUNDERSTORMS. AIRMASS ON SUNDAY WILL BE RATHER JUICY WITH PWATS AROUND 2 INCHES INDICATING THE POTENTIAL FOR HEAVY DOWNPOURS IN ANY CONVECTION. THE SEVERE POTENTIAL LOOKS MINIMAL AS FRONTAL FORCING IS WEAK ALONG WITH MID LEVEL LAPSE RATES. DEEP LAYER SHEAR IS FAIRLY HEALTHY ALONG WITH MID LEVEL WIND FIELDS ALTHOUGH CAPE LOOKS LIMITED DUE TO ABOVE MENTIONED MID LEVEL LAPSE RATES AND LACK OF SIGNIFICANT HEATING DUE TO EXTENSIVE CLOUD COVER EXPECTED BY DAYBREAK. WILL CONTINUE TO MONITOR. SUNDAY NIGHT...INCLUDED LINGERING EVENING ACTIVITY WITH REMAINDER OF PERIOD DRY AS WAVE PASSES. MONDAY...BRIEF RIDGING ALOFT AND AT THE SFC WILL PROVIDE A PARTLY SUNNY DAY WITH MAXES IN THE LOWER TO MIDDLE 80S. WILL CONTINUE WITH LOW CHC POPS DUE TO CONTINUED MOIST AIRMASS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UPR RDG OVER THE ERN U.S. WILL BE FLATTENED BY STRONGER ZONAL FLOW MOVG INTO THE GTLAKES EARLY NXT WEEK. ASSOCIATED FNTL SYSTEM WILL MOV THRU THE RGN IN THE TUE/TUE NGT TIME FRAME WITH SHRA/TSRA. HIGH PRES IS XPCTD TO REBUILD INTO THE AREA BY WED. SOME TIMING DIFFS AFTER THIS POINT W/RESPECT TO NXT UPSTREAM SYSTEM. WPC GUIDANCE LOOKED GOOD BUT WE MADE A FEW MINOR ADJUSTMENTS..1) SHOWED MORE IN THE WAY OF CLDS WITH MIDWEEK FROPA, AND 2) LIMITED POPS TO HI CHC GIVEN WE`RE STILL SVRL DAYS OUT. SEASONAL TO SLIGHTLY ABV NORMAL TEMPS. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... VFR WILL PREVAIL FOR THE REMAINDER OF THE AFTN AND INTO THE EVNG HRS WITH FEW-SCT DIURNAL CU AND SCT-BKN CI. LATER TNGT...PROFILES FROM THE NAM/GFS SUGGEST ADVECTION/DVLPMNT OF LOWER-LVL STRATUS INTO PORTIONS OF NE PA AND THE SRN TIER OF NY. RUC AND LCL WRF PROFILES ARE NOT AS ADAMANT ON THIS DVLPMNT. ATTM SAT PIX SHOW LTL IN THE WAY OF LOWER CLDS TO OUR S AND SE...SO HEDGED HERE INDICATING POTNL FOR SCT 1.5-2.5 KFT AT AVP/BGM AFTER 09Z. AT ELM...A TUFF CALL BUT THINK ANY RESTRICTIONS THERE WOULD BE RELATED TO VLY FOG/STRATUS FORMATION. VFR TO PREVAIL TMRW AFTER ANY EARLY MRNG STRICTIONS. WINDS TNGT SELY 5 KTS OR LESS...BECMG SRLY 10-15 KTS ON SAT. OUTLOOK... SATURDAY...PRIMARILY VFR. SAT NIGHT...PATCHY MVFR LATE IN HZ/BR. SUN THROUGH TUESDAY...RESTRICTIONS FROM SCT SHRA/TSRA...MAINLY SUNDAY AND TUESDAY. WED...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...RRM NEAR TERM...RRM SHORT TERM...RRM LONG TERM... AVIATION...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
145 PM EDT FRI AUG 29 2014 .SYNOPSIS... HIGH PRESSURE WILL BRING FAIR WEATHER TO NY AND PA TODAY. A STORM SYSTEM WILL MOVE THROUGH NORTHERN NY AND BRING A CHANCE FOR THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... 950 AM UPDATE...LATEST VIS SHOWS MID/HIGH LEVEL CLOUDS ACROSS WESTERN NY AND INTO THE LAKE PLAIN. EXPECT THIS AREA OF HIGH CLOUDINESS TO SPREAD ACROSS THE NRN CWA THROUGH MID AFTERNOON IN AN AREA OF MID LEVEL WARMING. PARTLY SUNNY SKIES ARE STILL ANTICIPATED ACROSS THE NRN CWA WITH MOSTLY SUNNY SKIES IN THE CENTRAL/SOUTHERN AREAS. NO OTHER CHANGES. PREVIOUS DISC... PATCHY VALLEY FOG WILL BURN OFF BETWEEN 1230 AND 1330Z THIS MORNING. THEREAFTER HIGH PRESSURE WILL SETTLE IN FOR A SUNNY, CLEAR WEATHER DAY. STILL COOL IN THE BOUNDARY LAYER UP TO 850MB SO HAVE RESTRICTED MAX TEMPS TO THE MID AND UPPER 70S DESPITE NEAR FULL SUN. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... A STORM SYSTEM WILL PULL OUT OF THE GREAT LAKES AND SPREAD INCREASING MOISTURE INTO NY/PA SATURDAY AFTERNOON INTO SUNDAY. THERE IS A SLIGHT CHANCE FOR A SHOWER OR THUNDERSTORM OVER THE FAR WESTERN FA LATE SATURDAY. FRONT WILL PUSH TOWARD LAKES ERIE AND ONTARIO SATURDAY NIGHT, SO HAVE ORIENTED POPS FROM NE TO SW. STICKING TO MAINLY CHC/SCT COVERAGE AS INSTABILITY AND FORCING ARE LACKING. EXPECT FAR SERN FA TO REMAIN DRY. SEVERAL HUNDRED JOULES OF CAPE FORECAST FOR SUNDAY AHEAD OF FRONTAL PUSH. NOT A TON OF INSTABILITY, BUT ENOUGH TO PUSH THE POPS INTO THE HIGH CHANCE TO LIKELY RANGE. BULK SHEAR VALUES ARE SUGGESTIVE OF SOME ORGANIZATION (AROUND 30+ KTS) SO WILL NEED TO KEEP AN EYE ON ISOLATED STRONG CONVECTIVE POTENTIAL. && .LONG TERM /MONDAY THROUGH THURSDAY/... UPR RDG OVER THE ERN U.S. WILL BE FLATTENED BY STRONGER ZONAL FLOW MOVG INTO THE GTLAKES EARLY NXT WEEK. ASSOCIATED FNTL SYSTEM WILL MOV THRU THE RGN IN THE TUE/TUE NGT TIME FRAME WITH SHRA/TSRA. HIGH PRES IS XPCTD TO REBUILD INTO THE AREA BY WED. SOME TIMING DIFFS AFTER THIS POINT W/RESPECT TO NXT UPSTREAM SYSTEM. WPC GUIDANCE LOOKED GOOD BUT WE MADE A FEW MINOR ADJUSTMENTS..1) SHOWED MORE IN THE WAY OF CLDS WITH MIDWEEK FROPA, AND 2) LIMITED POPS TO HI CHC GIVEN WE`RE STILL SVRL DAYS OUT. SEASONAL TO SLIGHTLY ABV NORMAL TEMPS. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR WILL PREVAIL FOR THE REMAINDER OF THE AFTN AND INTO THE EVNG HRS WITH FEW-SCT DIURNAL CU AND SCT-BKN CI. LATER TNGT...PROFILES FROM THE NAM/GFS SUGGEST ADVECTION/DVLPMNT OF LOWER-LVL STRATUS INTO PORTIONS OF NE PA AND THE SRN TIER OF NY. RUC AND LCL WRF PROFILES ARE NOT AS ADAMANT ON THIS DVLPMNT. ATTM SAT PIX SHOW LTL IN THE WAY OF LOWER CLDS TO OUR S AND SE...SO HEDGED HERE INDICATING POTNL FOR SCT 1.5-2.5 KFT AT AVP/BGM AFTER 09Z. AT ELM...A TUFF CALL BUT THINK ANY RESTRICTIONS THERE WOULD BE RELATED TO VLY FOG/STRATUS FORMATION. VFR TO PREVAIL TMRW AFTER ANY EARLY MRNG STRICTIONS. WINDS TNGT SELY 5 KTS OR LESS...BECMG SRLY 10-15 KTS ON SAT. OUTLOOK... SATURDAY...PRIMARILY VFR. SAT NIGHT...PATCHY MVFR LATE IN HZ/BR. SUN THROUGH TUESDAY...RESTRICTIONS FROM SCT SHRA/TSRA...MAINLY SUNDAY AND TUESDAY. WED...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DJP NEAR TERM...DJP/RRM SHORT TERM...DJP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
147 PM EDT FRI AUG 29 2014 .SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT WILL STALL OUT ACROSS CENTRAL NORTH CAROLINA TODAY. THE FRONT WILL GRADUALLY DISSIPATE OVER THE WEEKEND AS A LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 1230 PM FRIDAY... AS OF 16Z...LATEST OBSERVATIONS/ANALYSIS INDICATES THE SURFACE FRONT HAS MADE IT THROUGH 2/3RDS THE FORECAST AREA. EXTENSIVE CLOUD COVER IS NOTED WITHIN THE NORTHEASTERLY FLOW ALONG AND NORTH OF THE FRONT...WITH MOSTLY CLEAR SKIES ACROSS THE EXTREME SOUTH. THERE STILL IS A GREAT LEVEL OF DISAGREEMENT AMONG THE MODELS WITH RESPECT TO THE EVOLUTION OF THIS CLOUD COVER...WITH THE NAM KEEPING THE NORTHERN HALF OF THE FORECAST AREA MOSTLY CLOUDY ALL DAY AND THE GFS AND RAP BREAKING OUT THE CLOUDS SOME WITH MORE IN THE WAY OF EASTERLY/SOUTHEASTERLY FLOW LATER TODAY. HOWEVER...THE CLOUDS ARE HANGING IN AND TEMPS REMAINED IN THE 70S ACROSS MUCH OF THE NORTHERN TIER...MORE SIMILAR TO THE NAM. SENT OUT AN UPDATE TO REFLECT ALL OF THIS...WITH HIGHS NOW EXPECTED TO BE IN THE LOW/MID 80S ACROSS THE NORTH TO THE LOWER 90S ACROSS THE EXTREME SOUTH. WITH REGARDS TO PRECIP CHANCES...ISOLATED TO SCATTERED CONVECTION IS STILL EXPECTED LATER THIS AFTERNOON... ESPECIALLY IN THE VICINITY OF THE FRONT...HOWEVER RECENT MODELS TRENDS ARE SHOWING VERY LITTLE IN THE WAY OF COVERAGE. OVERNIGHT LOWS WILL GENERALLY RANGE FROM THE UPPER 60S ACROSS THE NORTH TO THE LOWER 70S FURTHER SOUTH. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 220 AM FRIDAY... CENTRAL NC WILL REMAIN UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE SAT/SAT NIGHT AS THE CENTER OF THE RIDGE CURRENTLY OVER THE SOUTHEAST STATES SHIFTS SLIGHTLY EAST TOWARD THE COAST. THE LINGERING FRONTAL ZONE OVER PORTIONS OF CENTRAL NC SHOULD WASH OUT DURING THE DAY AS A LIGHT S/SE RETURN FLOW DEVELOPS ACROSS THE REGION. FORECAST SOUNDINGS SUGGEST MARGINAL DESTABILIZATION WITH 500- 1500 J/KG OF MLCAPE SAT AFTERNOON. GIVEN A PROTOTYPICAL SUMMERTIME `RIDGE` PATTERN...EXPECT ABOVE NORMAL TEMPS...IN THE LOWER 90S. MARGINAL INSTABILITY AND SEASONABLE MOISTURE (PWAT VALUES OF 1.50- 1.75") WOULD SUPPORT ISOLD CONVECTION ON SATURDAY...THOUGH FORCING FOR ASCENT WILL BE LIMITED TO THE SEABREEZE AND DIFFERENTIAL HEATING...PRIMARILY ALONG THE HIGHER TERRAIN IN WESTERN NC...AND IT IS POSSIBLE THAT NO CONVECTION WILL DEVELOP IN CENTRAL NC. WITH THE ABOVE IN MIND...WILL INDICATE A SLIGHT CHANCE OF CONVECTION DURING THE AFT AND EARLY EVE HOURS IN THE WESTERN PIEDMONT AND SE COASTAL PLAIN. EXPECT NEAR NORMAL LOWS SAT NIGHT IN THE UPPER 60S TO LOWER 70S. -VINCENT && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 245 AM FRIDAY... A RIDGE WILL BUILD OVER THE SOUTHEASTERN STATES EARLY TO MID WEEK. THIS WILL EXTEND OUR CURRENT MORE SUMMER-LIKE PATTERN ACROSS NC WELL INTO WEDNESDAY. THE CORE OF THE UPPER RIDGE IS FORECAST TO BE OVER THE NC/SC COAST SUNDAY. THE APPROACHING UPPER TROUGH FROM THE OHIO VALLEY WILL BE DEFLECTED TO OUR NORTH AND WEAKEN SUNDAY NIGHT AND MONDAY. EVEN WITH THE HEAT AND HUMIDITY WITH THE SOUTHERLY RETURN FLOW... ONLY ISOLATED AFTERNOON THUNDERSTORMS ARE EXPECTED. THE BEST CHANCE IS FORECAST OVER AND NEAR THE BLUE RIDGE WHERE INSTABILITY... MOISTURE... AND LIFT WILL BE HIGHEST. HIGHS SHOULD REACH THE 88-93 RANGE. THE CORE OF THE UPPER RIDGE IS FORECAST TO SHIFT SOUTHWEST WITH TIME TO OVER THE GULF COAST STATES TUE-WED. THIS WILL ALLOW A WEAK PIEDMONT TROUGH AT THE SURFACE WHICH MAY AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS DURING THE AFTERNOON AND EVENING EARLY TO MID WEEK. OTHERWISE... SIMPLY WARM AND HUMID WITH PARTLY CLOUDY SKIES. LOWS 69-74. HIGHS 88-93 NW TO SANDHILLS. FOR MID TO LATE WEEK... ANY SURFACE FRONT IS EXPECTED TO BE WEAK AND PROVIDE LITTLE IF ANY COOLING OR DRYING. HOWEVER... IT MAY ACT AS A CONTINUED FOCUS FOR SCATTERED MAINLY AFTERNOON THUNDERSTORMS WED- FRI. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 130 PM FRIDAY... A COLD FRONT HAS SHIFTED SOUTH THROUGH THE AREA THROUGHOUT THE DAY TODAY...WITH FAIRLY EXTENSIVE CLOUD COVER ALONG AND NORTH OF THE BOUNDARY...WITH MOSTLY CLEAR SKIES SOUTH OF THE FRONT (I.E. EXTREME SOUTHERN PORTIONS OF THE FORECAST AREA...KFAY). THESE MVFR CIGS HAVE PERSISTED ALL DAY AND WILL LIKELY PERSIST FOR AT LEAST THE NEXT COUPLE OF HOURS. SOME BREAKS THIS AFTERNOON ARE STILL POSSIBLE... WITH A BRIEF RETURN TO VFR CONDITIONS INTO THE EVENING HOURS. HOWEVER...THE MOIST AIR MASS AND LIGHT AND VARIABLE WINDS OVERNIGHT SHOULD RESULT IN FOG/LOW STRATUS DEVELOPMENT...WITH IFR/LIFR CONDITIONS EXPECTED (ESPECIALLY TOWARDS THE NORTHEASTERN PORTIONS OF THE FORECAST AREA...KRWI...KRDU). CONDITIONS ARE EXPECTED TO IMPROVE TO VFR BY MID SATURDAY MORNING AS THE FRONT GRADUALLY WASHES OUT OVER THE AREA. AN ISOLATED SHOWER OR STORM WILL BE POSSIBLE LATER THIS AFTERNOON/EVENING AND AGAIN SATURDAY AFTERNOON...ALTHOUGH COVERAGE WILL RATHER SPARSE. OUTLOOK...A SUMMERTIME PATTERN WILL PERSIST THROUGH EARLY/MID NEXT WEEK...WITH ISOLATED TO SCATTERED AFTERNOON/EVENING CONVECTION AND A POTENTIAL FOR EARLY MORNING FOG/STRATUS. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...KRD SHORT TERM...VINCENT LONG TERM...PWB AVIATION...KRD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1238 PM EDT FRI AUG 29 2014 .SYNOPSIS...A SLOW MOVING BACK DOOR COLD FRONT WILL STALL OUT ACROSS CENTRAL NORTH CAROLINA TODAY. THE FRONT WILL GRADUALLY DISSIPATE OVER THE WEEKEND AS A LIGHT SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 1230 PM FRIDAY... AS OF 16Z...LATEST OBSERVATIONS/ANALYSIS INDICATES THE SURFACE FRONT HAS MADE IT THROUGH 2/3RDS THE FORECAST AREA. EXTENSIVE CLOUD COVER IS NOTED WITHIN THE NORTHEASTERLY FLOW ALONG AND NORTH OF THE FRONT...WITH MOSTLY CLEAR SKIES ACROSS THE EXTREME SOUTH. THERE STILL IS A GREAT LEVEL OF DISAGREEMENT AMONG THE MODELS WITH RESPECT TO THE EVOLUTION OF THIS CLOUD COVER...WITH THE NAM KEEPING THE NORTHERN HALF OF THE FORECAST AREA MOSTLY CLOUDY ALL DAY AND THE GFS AND RAP BREAKING OUT THE CLOUDS SOME WITH MORE IN THE WAY OF EASTERLY/SOUTHEASTERLY FLOW LATER TODAY. HOWEVER...THE CLOUDS ARE HANGING IN AND TEMPS REMAINED IN THE 70S ACROSS MUCH OF THE NORTHERN TIER...MORE SIMILAR TO THE NAM. SENT OUT AN UPDATE TO REFLECT ALL OF THIS...WITH HIGHS NOW EXPECTED TO BE IN THE LOW/MID 80S ACROSS THE NORTH TO THE LOWER 90S ACROSS THE EXTREME SOUTH. WITH REGARDS TO PRECIP CHANCES...ISOLATED TO SCATTERED CONVECTION IS STILL EXPECTED LATER THIS AFTERNOON... ESPECIALLY IN THE VICINITY OF THE FRONT...HOWEVER RECENT MODELS TRENDS ARE SHOWING VERY LITTLE IN THE WAY OF COVERAGE. OVERNIGHT LOWS WILL GENERALLY RANGE FROM THE UPPER 60S ACROSS THE NORTH TO THE LOWER 70S FURTHER SOUTH. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 220 AM FRIDAY... CENTRAL NC WILL REMAIN UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE SAT/SAT NIGHT AS THE CENTER OF THE RIDGE CURRENTLY OVER THE SOUTHEAST STATES SHIFTS SLIGHTLY EAST TOWARD THE COAST. THE LINGERING FRONTAL ZONE OVER PORTIONS OF CENTRAL NC SHOULD WASH OUT DURING THE DAY AS A LIGHT S/SE RETURN FLOW DEVELOPS ACROSS THE REGION. FORECAST SOUNDINGS SUGGEST MARGINAL DESTABILIZATION WITH 500- 1500 J/KG OF MLCAPE SAT AFTERNOON. GIVEN A PROTOTYPICAL SUMMERTIME `RIDGE` PATTERN...EXPECT ABOVE NORMAL TEMPS...IN THE LOWER 90S. MARGINAL INSTABILITY AND SEASONABLE MOISTURE (PWAT VALUES OF 1.50- 1.75") WOULD SUPPORT ISOLD CONVECTION ON SATURDAY...THOUGH FORCING FOR ASCENT WILL BE LIMITED TO THE SEABREEZE AND DIFFERENTIAL HEATING...PRIMARILY ALONG THE HIGHER TERRAIN IN WESTERN NC...AND IT IS POSSIBLE THAT NO CONVECTION WILL DEVELOP IN CENTRAL NC. WITH THE ABOVE IN MIND...WILL INDICATE A SLIGHT CHANCE OF CONVECTION DURING THE AFT AND EARLY EVE HOURS IN THE WESTERN PIEDMONT AND SE COASTAL PLAIN. EXPECT NEAR NORMAL LOWS SAT NIGHT IN THE UPPER 60S TO LOWER 70S. -VINCENT && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 245 AM FRIDAY... A RIDGE WILL BUILD OVER THE SOUTHEASTERN STATES EARLY TO MID WEEK. THIS WILL EXTEND OUR CURRENT MORE SUMMER-LIKE PATTERN ACROSS NC WELL INTO WEDNESDAY. THE CORE OF THE UPPER RIDGE IS FORECAST TO BE OVER THE NC/SC COAST SUNDAY. THE APPROACHING UPPER TROUGH FROM THE OHIO VALLEY WILL BE DEFLECTED TO OUR NORTH AND WEAKEN SUNDAY NIGHT AND MONDAY. EVEN WITH THE HEAT AND HUMIDITY WITH THE SOUTHERLY RETURN FLOW... ONLY ISOLATED AFTERNOON THUNDERSTORMS ARE EXPECTED. THE BEST CHANCE IS FORECAST OVER AND NEAR THE BLUE RIDGE WHERE INSTABILITY... MOISTURE... AND LIFT WILL BE HIGHEST. HIGHS SHOULD REACH THE 88-93 RANGE. THE CORE OF THE UPPER RIDGE IS FORECAST TO SHIFT SOUTHWEST WITH TIME TO OVER THE GULF COAST STATES TUE-WED. THIS WILL ALLOW A WEAK PIEDMONT TROUGH AT THE SURFACE WHICH MAY AID IN THE DEVELOPMENT OF SCATTERED THUNDERSTORMS DURING THE AFTERNOON AND EVENING EARLY TO MID WEEK. OTHERWISE... SIMPLY WARM AND HUMID WITH PARTLY CLOUDY SKIES. LOWS 69-74. HIGHS 88-93 NW TO SANDHILLS. FOR MID TO LATE WEEK... ANY SURFACE FRONT IS EXPECTED TO BE WEAK AND PROVIDE LITTLE IF ANY COOLING OR DRYING. HOWEVER... IT MAY ACT AS A CONTINUED FOCUS FOR SCATTERED MAINLY AFTERNOON THUNDERSTORMS WED- FRI. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 730 AM FRIDAY... 24-HR TAF PERIOD: BELOW AVERAGE CONFIDENCE IN THE FORECAST THROUGH TONIGHT. THE NAM MODEL GUIDANCE BEST MATCHES THE LATEST OBS DATA... WHICH SUGGESTS THE NORTHERN TERMINALS (INT/GSO/RDU/RWI) WILL BE AFFECTED BY PERIODIC OR PERSISTENT IFR/MVFR CEILINGS THIS MORNING... WITH IMPROVEMENT TO MVFR DURING THE AFTERNOON. MVFR CEILINGS AND ISOLD CONVECTION WILL BE POSSIBLE THROUGH THE AFTERNOON AND EVENING HOURS. GIVEN THE LATEST TRENDS...A MORE PESSIMISTIC FORECAST MAY BE NECESSARY TONIGHT THROUGH SAT MORNING AT THE NORTHERN TERMINALS WHERE CONDITIONS MAY DETERIORATE TO IFR/LIFR OVERNIGHT BEFORE GRADUALLY IMPROVING TO VFR BY SAT AFTERNOON. LOOKING AHEAD: EXPECT A NEAR CLIMATOLOGICAL PATTERN THROUGH EARLY NEXT WEEK WITH A SLIGHT CHANCE OF AFTERNOON/EVENING CONVECTION AND A POTENTIAL FOR EARLY MORNING FOG/STRATUS. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...KRD SHORT TERM...VINCENT LONG TERM...PWB AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1241 PM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 1242 PM CDT FRI AUG 29 2014 CURRENT VIS SAT SHOWING WIDENING CLEARING OVER THE SOUTH CENTRAL PORTION OF NORTH DAKOTA...RIGHT AHEAD OF THE SFC TROUGH. HAVE REDUCED POPS ELSE WHERE ACROSS THE CWA AND INCREASED TO ABOUT 40S THE POPS OVER SOUTHEASTERN ND. SKIES ACROSS EAST CENTRAL AND NORTHEAST ND ARE BEGINNING TO THIN AS WELL...HOWEVER TEMPS ARE STILL A GOOD 5 DEG COOLER SO WILL HOLD OFF ON INCREASING POPS AT THIS POINT. NO OTHER CHANGES TO IMMEDIATE SHORT TERM FOR THIS UPDATE. UPDATE ISSUED AT 952 AM CDT FRI AUG 29 2014 CURRENT RADAR SHOWING SOME WEAK SHOWERS OVER THE FAR SOUTHERN VALLEY DRIFTING OUT OF CWA. ALSO A STRONG STORM SOUTH OF MANITOBA MOVING EASTWARD ACROSS SOUTHERN MANITOBA AND NOT EXPECTED TO DROP INTO THE CONUS...HOWEVER WILL NEED TO WATCH LOW COUNTY IF IT HOLDS TOGETHER THAT LONG. MAIN ISSUE TODAY WILL BE CLOUDS. WHILE THE NAM SEEMS RATHER BULLISH WITH QPFS ASSOCIATED WITH ACTIVITY ACROSS EASTERN SD AND NORTH CENTRAL/EASTERN MN...POPS FOR THE SHARP SFC TROUGH MOVING ACROSS THE CWA TODAY SEEM REASONABLE. WILL TREND POPS TOWARD THE NAM SOLUTION FOR THIS AFTN. THERE ARE SOME SIGNS OF SKY BREAKING UP ACROSS EASTERN ND THIS MORNING TO PROVIDE SOME SOLAR FOR AFTN CONVECTION AS THE TROUGH MOVES THROUGH...HOWEVER THIS ACTIVITY WILL BE VERY DEPENDENT ON HOW MUCH SOLAR CAN GET THROUGH SO WILL LIMIT POPS TO LOW END OF CHANCE CATEGORY. ALSO HAVE REMOVED THUNDER AS PREDOMINANT PTYPE AND CHANGED OVER TO RAIN SHOWERS WITH ISOLD TSTMS. NO OTHER CHANGES EXPECTED THIS UPDATE. UPDATE ISSUED AT 655 AM CDT FRI AUG 29 2014 NO SIG UPDATES NEEDED AT THIS TIME. BANDS OF LIGHT RAIN ARE MOVING THROUGH THE BWP-FFM-PKD-BJI AREA IN THE DEFORMATION ZONE AT THE AHEAD OF THE LOW PRESSURE SYSTEM NOW IN SOUTHWEST MN. MEANWHILE A WINDSHIFT LINE IS APPARENT ON RADAR IMAGERY ALG A YWG-DVL-BIS LINE SHOWING THE APPROACHING LOW PRESSURE SYSTEM NOW EDGING INTO THE NORTHWEST CORNER OF THE FA. FOCUS FOR SHOWERS AND THUNDER SHOULD SHIFT TO THIS SYSTEM FOR LATER IN THE DAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 TODAY...AREAS OF LOW CLOUDS AND VERY LIGHT RAIN WILL SHIFT EASTWARD FROM NORTHWEST MN THROUGH THE FORENOON... WITH SOME PATCHY SUNSHINE POSSIBLE THROUGH THE MIDDAY PERIOD. A COLD FRONT APPROACHING FROM SOUTHWEST MANITOBA WILL BRING INCREASING CLOUDS INTO NORTHEAST ND DURING THE FORENOON AND PUSH THROUGH THE AREA DURING THE AFTERNOON. EXPECT SCT SHOWERS AND AN ISOLATED THUNDERSTORM OF TWO...WITH GUSTY NORTHWEST WINDS KICKING IN BEHIND THE FRONT LATER TODAY. AS PER THREAT OF SEVERE STORMS TODAY... WHILE DEEP LAYER SHEER IS WEAK TODAY AND DEEP MOISTURE ADVECTION IS TIED UP BY THE MORE ORGANIZED SYSTEM IN THE CENTRAL PLAINS... EXPECTED DAYTIME HEATING AND LOCALLY AVAILABLE MOISTURE LOOK TO BE SUFFICIENT FOR 1000 TO 2000 J/KG OF CAPE BY MID AFTERNOON... SO AN ISOLATED SEVERE STORM IS POSSIBLE. RUC COMPUTED 2 KM LAYERED VGP APPROACHES 0.2 FROM 18 INTO 21Z WITH LAYERED CAPE EXCEEDING 500 J/KG... ALMOST ENOUGH FOR A BRIEF SPINUP TO OCCUR. CERTAINLY WORTH PAYING ATTENTION TOO... THUS LATEST SPC DAY1 OUTLOOK CONTAINS A /SEE TEXT/ OVER OUR AREA. TONIGHT AND SATURDAY...EXPECT GENERAL POSTFRONTAL DRYING AND SEASONABLY COOL OVERNIGHT TEMPERATURES ESPECIALLY OVER THE NORTHERN HALF OF THE FA. SOME LINGER SHOWERS ARE POSSIBLE INTO THE LATE EVENING OVER NORTH CENTRAL MN LAKES. SATURDAY SHOULD BE DRY AND SEASONABLY WARM ...WITH SOUTHERLY RETURN FLOW INCREASING THROUGH THE AFTERNOON... AHEAD OF THE NEXT APPROACHING SYSTEM. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 415 AM CDT FRI AUG 29 2014 SATURDAY NIGHT AND SUNDAY...LOW PRESSURE DIGS INTO THE WRN DKTAS LATE ON SATURDAY WITH DEEP CONVECTION EXPECTED TO CROSS INTO CENTRAL ND THROUGH MIDNIGHT. BY SUNDAY MORNING MOST OF THE ACTIVITY WILL SHIFT INTO ERN ND AND THE RED RIVER VALLEY... OVERSPREADING NORTHWEST MINNESOTA THROUGH THE FORENOON. WITH MODELS IN GENERAL AGREEMENT ON PLACING THE SFC TROF ALG THE RRV AROUND 18Z... WILL EXPECT DEEP CONVECTION AND THE POSSIBILITY FOR ISOLATED SEVERE STORMS AND LOCALLY HEAVY RAINS ALG AND EAST OF THE RRV DURING THE AFTERNOON... CONSISTENT WITH CURRENT SPC/WPC DAY3 OUTLOOKS. MONDAY THROUGH THURSDAY...FLOW BEGINS TO TRANSITION TO MORE WESTERLY THEN SOUTHWESTERLY AS A LARGE TROUGH OVER THE NORTHERN PLAINS MONDAY MOVES OFF TO THE EAST AND THE NEXT SYSTEM DIGS INTO THE PAC NW. THINK THAT THE BEST CHANCES FOR PRECIP WILL BE LATE IN THE PERIOD AS THE NEXT SFC LOW TRAVELS THROUGH SOUTH DAKOTA AND PUTS OUR CWA IN THE PRIME DEFORMATION ZONE FOR PRECIPITATION. HOWEVER...THERE WILL BE SOME LINGERING PRECIP ON THE BACKSIDE OF THE DEPARTING LOW ON MONDAY AND EVEN DURING THE MIDDLE OF THE WEEK SOME MODELS ARE BREAKING OUT SPITS OF PRECIP IN SOUTHWEST FLOW ALOFT. WILL CONTINUE TO KEEP THE LOW POPS THAT ALLBLEND GIVES US BUT WILL REFINE LATER. TEMPS WILL BE NEAR SEASONAL AVERAGES THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1242 PM CDT FRI AUG 29 2014 SCATTERED IFR CONDITIONS SHOULD RISE INTO THE MVFR CATEGORY THIS AFTERNOON. WINDS WILL SHIFT TO THE NORTH BEHIND THE FRONT AND GUST INTO THE 20-25KT RANGE IN THE NORTH THROUGH 03Z. MVFR CIGS SHOULD SLOWLY CLEAR OVERNIGHT IN ALL BUT THE FAR EAST/SOUTH. WINDS WILL BECOME LIGHT AND VARIABLE SAT MORNING WITH HIGH PRESSURE OVERHEAD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...SPEICHER SHORT TERM...GUST LONG TERM...GUST/JR AVIATION...DK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
954 AM PDT FRI AUG 29 2014 .SYNOPSIS...COOLER WESTERLY FLOW ALOFT IS INCREASING. THIS WILL BRING CLOUDS AND COOLER AIR TO THE REGION...ALONG WITH A THREAT OF SHOWERS FOR THIS WEEKEND. BEST CHANCES OF SHOWERS WILL BE ON SATURDAY AND LATE SUNDAY. DRY AND MILD WEATHER RESUMES NEXT WEEK. && .SHORT TERM...THROUGH SUNDAY...SURFACE FRONT CURRENTLY OFFSHORE SHOULD STALL NEAR THE COAST THIS AFTERNOON...BUT THE UPPER PORTION OF THE FRONT SHEARS OFF AND MOVES INLAND IN THE AFTERNOON SO PRECIP CHANCES WILL MAINLY BE LIMITED TO N OREGON COAST AND SW WASHINGTON COAST. RADAR CURRENTLY SHOWS SOME DRIZZLE OR LIGHT SHOWERS MOVING TOWARD MOSTLY THE SW WASHINGTON COAST. 15Z HRRR INDICATES A BAND OF LIGHT PRECIP MOVING ONTO THE COAST AND AFFECTING AS FAR SOUTH AS TILLAMOOK COUNTY BETWEEN 19Z AND 23Z WHICH LOOKS TO BE THE BEST CHANCE OF RAIN ANYWHERE IN THE FORECAST AREA TODAY. ANY PRECIP LATER IN THE AFTERNOON AND EVENING WOULD LIKELY BE OROGRAPHICALLY ENHANCED SO SLIGHT CHANCE REMAINS PARTICULARLY ON THE WINDWARD SIDE OF THE COAST RANGE AND CASCADES...WITH MOISTURE FAVORING NORTH OREGON AND SOUTH WASHINGTON. COOLER TEMPS TODAY WITH MORE CLOUD COVER AND LOWERING 500 MB HEIGHTS AS THE UPPER TROUGH MOVES INTO THE REGION. A SHORTWAVE TROUGH ARRIVES SAT AFTERNOON FOR A LITTLE MORE COOLING AND A CHANCE OF SHOWERS...AGAIN MAINLY FOR THE COAST AND NORTHERN INTERIOR ZONES. SOME UPPER LEVEL SUPPORT FOR SOME SHOWERS SUNDAY ACROSS THE NORTHERN PART OF THE FORECAST AREA WITH CONTINUED COOLER TEMPERATURES. BOWEN/26 .LONG TERM...MODELS ARE TRENDING TOWARD ANOTHER SYSTEM ARRIVING SUN NIGHT AND MON.SURFACE FEATURES WEAKEN AS THE FRONT APPROACHES THE COAST...BUT 850MB AND 700MB ONSHORE WINDS WILL ADVECT MOISTURE INTO THE AREA. THIS COMBINED WITH TOTAL PRECIPITABLE WATER AROUND 1.25 INCH WILL INTRODUCE CHANCE POPS TO THE FAR NORTHERN ZONES. FURTHER ON IN THE WEEK...THE UPPER RIDGE IS NOT BUILDING QUITE SO STRONGLY AS BEFORE. THERE IS MORE ENERGY BEING PUT INTO CARVING OUT A TROUGH OVER WESTERN CANADA THE EVENTUALLY SAGS INTO THE WESTERN U.S LATE IN THE WEEK. THE AIR MASS WILL BE GENERALLY DRY SO THREAT OF SHOWERS REMAIN LOW AT THIS POINT. HIGH TEMPERATURES LIKELY AT OR BELOW SEASONAL NORMALS. THE TIMING AND LOCATION OF THESE SHOWERS ARE STILL UNCERTAIN AS BOTH THE GFS AND ECMWF HAVE SLIGHTLY DIFFERENT FORECAST. THESE WILL BE FURTHER REFINED WITH FUTURE UPDATES. /64/26 && .AVIATION...A WEAK FRONT WILL MOVE ACROSS SOUTHWEST WASHINGTON AND NORTHWEST OREGON TODAY. THE FRONT WAS SEEN ON RADAR NEAR KHQM AT 930 AM WITH SOME CONVECTIVE SHOWERS OVER THE WATERS BEHIND THE FRONT. CLOUDS HAVE DEVELOPED OVER MUCH OF WESTERN WASHINGTON THIS MORNING WITH IFR AND LIFR ALONG THE NORTH COAST AND MOSTLY MVFR CONDITIONS INLAND. EXPECT THE LIFR AND IFR CONDITIONS TO IMPROVE ALONG THE N OREGON COAST AS THE FRONT APPROACHES AND LIFTS THE MARINE INVERSION AFTER 18Z BECOMING MVFR. THERE WILL BE SOME DRIZZLE AND LIGHT RAIN AS THE FRONT MOVES IN MIDDAY ALONG THE COAST. INLAND...EXPECT MOSTLY MVFR CONDITIONS TO CONTINUE WITH A SLIGHT CHANCE OF SOME LIGHT SHOWERS MAINLY FROM NORTH OF KAUO 19Z-22Z. CLOUDS SHOULD BREAK OUT SOME AND LIFT AFT 20-21Z. MARINE LAYER SHOULD CONTINUE TO DEEPEN OVERNIGHT TONIGHT. SCHNEIDER KPDX AND APPROACHES...MVFR CIGS 015 TO 020 WILL CONTINUE THROUGH 20Z THEN LIFT SOME AND BECOME VFR AFTER 21-22Z. SCHNEIDER && .MARINE...WEAK FRONT MOVING ACROSS THE WATERS TODAY WITH SOME BRIEF LIGHT RAIN OVER THE WATERS NORTH OF CASCADE HEAD TODAY. WINDS WILL REMAIN LIGHT SOUTHWESTERLY TODAY AND THEN SHIFT MORE WESTERLY THIS EVENING. SEVERAL MORE WEAK FRONTS WILL PASS OVER THE WATERS DURING THE WEEKEND. THE SEAS WILL COMPRISE OF A SMALL SW SWELL AT AROUND 15 SECONDS AND A NORTHWEST FRESH SWELL FROM THE GULF OF ALASKA AROUND 9 SECONDS. LIGHT WIND WAVES THE NEXT COUPLE OF DAYS. A NW SWELL WILL BUILD SATURDAY NIGHT AND PEAK AROUND 7 FEET ON SUNDAY. HIGH PRESSURE WILL REBUILD MONDAY NIGHT AND TUESDAY AND PERSISTENT NORTHERLY WINDS WILL RETURN TO THE WATERS. SCHNEIDER && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
208 PM EDT FRI AUG 29 2014 .SYNOPSIS... A WEAK FRONT WILL BE STATIONARY FROM NORTH CAROLINA TO MISSOURI TODAY. THIS FRONT WILL LIFT NORTH INTO THE OHIO VALLEY TONIGHT. A STRONGER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS FOR SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1247 PM EDT FRIDAY... LATEST LAPS DATA ARE SHOWING SURFACE BASED LI OF -2 TO -3 AND CAPS AROUND 500 J/KG ACROSS TAZEWELL AND SMYTH COUNTIES. HIGHER VALUES EXIST WEST OF THE FORECAST AREA IN SOUTHERN WEST VIRGINIA AND NORTHEAST TENNESSEE. NO SHOWERS DETECTED YET ON REGIONAL RADARS IN THAT REGION...BUT VISIBLE SATELLITE IMAGERY IS STARTING TO SHOW THE DEVELOPMENT OF CUMULUS CLOUDS...SO AM NOT EXPECTING TOO LONG OF WAIT FOR THE FIRST SHOWERS TO DEVELOP. LATEST HRRR AND RNK WRF- ARW ARE ON TARGET FOR ABOUT A 18-19Z/2PM-3PM INITIATION TIME. THE OTHER AREA OF THE REGION THAT WE HAVE BEEN WATCHING FOR DEVELOPMENT IS SOUTHSIDE VIRGINIA AND NEIGHBORING NORTH CENTRAL NORTH CAROLINA. THIS REGION HAS HAD DECENT CLOUD COVER OVER IT FOR THE MORNING...AND NOW THE EARLY AFTERNOON. LAPS...AS EXPECTED...STILL HAS THE AREA STABLE. FOR OUR FORECAST...HAVE DELAYED THE ONSET OF ANY ISOLATED SHOWER OR THUNDERSTORM ACTIVITY UNTIL LATER IN THE AFTERNOON...PERHAPS STARTING AROUND OR AFTER 21Z/5PM. HAVE ALSO LOWERED EXPECTED HIGH TEMPERATURES IN THIS AREA BY A COUPLE OF DEGREES THANKS TO THE CLOUDS. HAVE RAISE FORECAST HIGHS IN THE FAR WESTERN PARTS OF THE ARE BASED UPON CURRENT TEMPERATURES AND CONTINUED WARMING TREND THROUGH THE AFTERNOON. AS OF 947 AM EDT FRIDAY... LATEST MESOSCALE MODELS STILL OFFERING BEST CHANCE FOR CONVECTION TODAY TO BE ACROSS THE WESTERN QUARTER OF THE REGION. LATEST LAPS DATA SHOW SURFACE BASED LI VALUES HAVE JUST DROPPED BELOW ZERO AND A FEW HUNDRED SURFACE BASED CAPE HAVE DEVELOPED IN WESTERN TAZEWELL AND SMYTH COUNTIES. THIS AREA AND THE SURROUNDING AREA IS EXPECTED TO BECOME MORE UNSTABLE WITH THE HEATING OF THE AFTERNOON. INITIAL CONVECTION TIME IS EXPECTED TO BE SOMEWHERE BETWEEN 17Z-18Z/1PM-2PM IN THIS REGION AND MAINTAIN THROUGH THE AFTERNOON. ANOTHER AREA WE ARE STILL WATCHING IS SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH CAROLINA. WHILE STILL STABLE AT THE SURFACE...THIS AREA IS EXPECTED TO BECOME UNSTABLE THIS AFTERNOON IN PROXIMITY TO THE STALLED FRONTAL BOUNDARY. NO MAJOR CHANGES TO THE FORECAST. AS OF 400 AM EDT FRIDAY... STATIONARY FRONT TRAILED FROM NORTHEAST NORTH CAROLINA TO NORTH CENTRAL TENNESSEE EARLY THIS MORNING. ALONG THE BOUNDARY AND WEST OF THE BLUE RIDGE MODELS WERE SHOWING A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. WILL BE STARTING OFF THE DAY CAPPED. EVEN IF THE CAP DOES BREAK...AS SUGGESTED BY BUFKIT NAM/RAP GUIDANCE...NOT MUCH INSTABILITY...AND NOT UNTIL AFTER 18Z. WITH THE SHORT WAVE ENERGY WELL WEST AND NORTH OF THE FORECAST AREA...LITTLE TO AIDE IN THE FORCING TODAY. AXIS OF POOLED MOISTURE AND LOW LEVEL CONVERGENCE ALONG THE WEAK BOUNDARY PIVOTS NORTHEAST TONIGHT AND WILL EXTEND FROM OHIO INTO EASTERN NORTH CAROLINA BY SATURDAY MORNING. WILL HAVE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS IN THE EXTREME SOUTHWEST COUNTY WARNING AREA. AREAL COVERAGE OF PRECIPITATION SHOULD ONLY BE ISOLATED TO SCATTERED. STORM MOTION WOULD BRING THE STORMS INTO SOUTHEAST WEST VIRGINIA AND POSSIBLY THE NEW RIVER VALLEY AROUND 00Z. BUT NOT MUCH INSTABILITY LEFT BY THAT TIME. SOUTHEAST WINDS AT THE SURFACE THROUGH LOW LEVELS...BRING 850-1000MB RELATIVE HUMIDITY UP TODAY AND BY TONIGHT LOW CLOUDS ARE EXPECTED TO ADVANCE TOWARD THE EAST SIDE OF THE APPALACHIANS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 310 AM EDT FRIDAY... UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A SOUTHERN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL STREAK OVER THE GULF COAST STATES AND ACROSS THE WESTERN SLOPES OF THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SOUTH-SOUTHEAST FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN THE EAST...MAINLY FROM THE EASTERN WV PANHANDLE SOUTHEAST TOWARD THE TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST WITH MID 80S WEST. SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER EVENING STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT LEAST SLIGHT CHANCE INTO THE MOUNTAINS LATE. SUNDAY LOOKS ACTIVE AS THE SHORTWAVE AXIS SHIFTS ACROSS KY INTO NORTHERN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR WHERE A FEW STORMS COULD PRODUCE GUSTY WINDS. THE SHORT WAVE AXIS SLOWLY SHIFTS TO THE EAST AND WITH A LEE TROUGH...CONVECTION FIRES LATE IN THE AFTERNOON AND MAY REMAIN OVER SOUTHSIDE UNTIL MIDNIGHT. HIGHS SUNDAY WILL RANGE FROM THE UPPER 70S MOUNTAINS TO UPPER 80S TOWARDS SOUTHSIDE. OVERALL...LABOR DAY WEEKEND LOOKING VERY WARM/HOT/HUMID. SATURDAY NOT TOO BAD RAIN WISE...BUT STAY COOL WHILE DRINKING PLENTY OF WATER IF OUTDOORS. SUNDAY APPEARS POOR FOR OUTDOOR ACTIVITIES. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE GULF COAST STATES BY THE END OF THE FORECAST PERIOD. SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO AND THROUGH THE GREAT LAKES INTO NEW ENGLAND. HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED OVER THE AREA. GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME. PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64 BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR. PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER 80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 130 PM EDT FRIDAY... VISIBILITY SENSOR AT KDAN REMAINS INOPERABLE. PARTS ARE ON ORDER. UNTIL REPAIRS COMPLETE...NO ADMENDMENTS WILL BE SCHEDULED. MORNING MVFR STRATOCU CLOUDS OVER MUCH OF THE CENTRAL AND SOUTHEASTERN PARTS OF THE REGION HAVE FINALLY ERODED...OR LIFTED TO LOW END VFR SCT-BKN. THE ATMOSPHERE IS BECOMING UNSTABLE ACROSS THE WESTERN PART OF THE REGION BETWEEN KBLF-KTNB. NEW MVFR-LOW END VFR CUMULUS CLOUDS ARE DEVELOPING IN THIS REGION...AND ISOLATED SHOWERS AND PERHAPS A FEW THUNDERSTORMS ARE EXPECTED THIS AFTERNOON INTO THE EARLY EVENING IN THIS REGION. OVERNIGHT...A STATIONARY FRONT WILL MAKE SOME PROGRESS NORTH AS A WARM FRONT ALONG WITH SOME PATCHY SHOWERS SOUTH OF IT. LOW LEVEL MOISTURE WILL INCREASE AN BECOME TRAPPED UNDER THE NOCTURNAL INVERSION. ANTICIPATE MOST OF THE REGION TO DEVELOP MVFR CIGS WITH SOME REGIONS OF IFR. VSBYS WILL ALSO DECREASE WITH MOST AREAS HAVING MVFR WITH POCKETS OF IFR. ANY SUB-VFR CONDITIONS WILL BE FAIRLY SLOW TO IMPROVE TO VFR AFTER SUNRISE SATURDAY. 15Z/11AM IS THE MOST LIKELY TIME MOST OF THE REGION WILL BE BACK TO VFR. EXTENDED DISCUSSION... ANY ISOLATED OR SCATTERED SHOWERS AND STORMS WILL BE MAINLY CONFINED TO AN AREA ALONG AND NORTH OF A KHSP-KFVX LINE SATURDAY AFTERNOON...JUST SOUTH OF THE AGAIN STALLED FRONTAL BOUNDARY. LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AN AREA OF LOW PRESSURE WILL HEAD EASTWARD THROUGH THE GREAT LAKES REGION TOWARD NEW ENGLAND. ITS ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE REGION BRINGING A GENEROUS COVERAGE OF SHOWERS AND SOME STORMS. SUB-VFR CONDITIONS ARE EXPECTED TO ACCOMPANY THE SYSTEM AND PRECIPITATION. ANOTHER COLD FRONT IS EXPECTED TO PRODUCE SIMILAR CIRCUMSTANCES TUESDAY INTO TUESDAY NIGHT. HOWEVER...MODEL GUIDANCE FOR THIS ONE OFFERS PRECIPITATION IN A MORE SCATTERED DISTRIBUTION. AS SUCH...THE MAGNITUDE OF SUB-VFR CONDITIONS MAY BE LESS. && .EQUIPMENT... AS OF 730 AM EDT FRIDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...WERT AVIATION...DS EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1254 PM EDT FRI AUG 29 2014 .SYNOPSIS... A WEAK FRONT WILL BE STATIONARY FROM NORTH CAROLINA TO MISSOURI TODAY. THIS FRONT WILL LIFT NORTH INTO THE OHIO VALLEY TONIGHT. A STRONGER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS FOR SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1247 PM EDT FRIDAY... LATEST LAPS DATA ARE SHOWING SURFACE BASED LI OF -2 TO -3 AND CAPS AROUND 500 J/KG ACROSS TAZEWELL AND SMYTH COUNTIES. HIGHER VALUES EXIST WEST OF THE FORECAST AREA IN SOUTHERN WEST VIRGINIA AND NORTHEAST TENNESSEE. NO SHOWERS DETECTED YET ON REGIONAL RADARS IN THAT REGION...BUT VISIBLE SATELLITE IMAGERY IS STARTING TO SHOW THE DEVELOPMENT OF CUMULUS CLOUDS...SO AM NOT EXPECTING TOO LONG OF WAIT FOR THE FIRST SHOWERS TO DEVELOP. LATEST HRRR AND RNK WRF- ARW ARE ON TARGET FOR ABOUT A 18-19Z/2PM-3PM INITIATION TIME. THE OTHER AREA OF THE REGION THAT WE HAVE BEEN WATCHING FOR DEVELOPMENT IS SOUTHSIDE VIRGINIA AND NEIGHBORING NORTH CENTRAL NORTH CAROLINA. THIS REGION HAS HAD DECENT CLOUD COVER OVER IT FOR THE MORNING...AND NOW THE EARLY AFTERNOON. LAPS...AS EXPECTED...STILL HAS THE AREA STABLE. FOR OUR FORECAST...HAVE DELAYED THE ONSET OF ANY ISOLATED SHOWER OR THUNDERSTORM ACTIVITY UNTIL LATER IN THE AFTERNOON...PERHAPS STARTING AROUND OR AFTER 21Z/5PM. HAVE ALSO LOWERED EXPECTED HIGH TEMPERATURES IN THIS AREA BY A COUPLE OF DEGREES THANKS TO THE CLOUDS. HAVE RAISE FORECAST HIGHS IN THE FAR WESTERN PARTS OF THE ARE BASED UPON CURRENT TEMPERATURES AND CONTINUED WARMING TREND THROUGH THE AFTERNOON. AS OF 947 AM EDT FRIDAY... LATEST MESOSCALE MODELS STILL OFFERING BEST CHANCE FOR CONVECTION TODAY TO BE ACROSS THE WESTERN QUARTER OF THE REGION. LATEST LAPS DATA SHOW SURFACE BASED LI VALUES HAVE JUST DROPPED BELOW ZERO AND A FEW HUNDRED SURFACE BASED CAPE HAVE DEVELOPED IN WESTERN TAZEWELL AND SMYTH COUNTIES. THIS AREA AND THE SURROUNDING AREA IS EXPECTED TO BECOME MORE UNSTABLE WITH THE HEATING OF THE AFTERNOON. INITIAL CONVECTION TIME IS EXPECTED TO BE SOMEWHERE BETWEEN 17Z-18Z/1PM-2PM IN THIS REGION AND MAINTAIN THROUGH THE AFTERNOON. ANOTHER AREA WE ARE STILL WATCHING IS SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH CAROLINA. WHILE STILL STABLE AT THE SURFACE...THIS AREA IS EXPECTED TO BECOME UNSTABLE THIS AFTERNOON IN PROXIMITY TO THE STALLED FRONTAL BOUNDARY. NO MAJOR CHANGES TO THE FORECAST. AS OF 400 AM EDT FRIDAY... STATIONARY FRONT TRAILED FROM NORTHEAST NORTH CAROLINA TO NORTH CENTRAL TENNESSEE EARLY THIS MORNING. ALONG THE BOUNDARY AND WEST OF THE BLUE RIDGE MODELS WERE SHOWING A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. WILL BE STARTING OFF THE DAY CAPPED. EVEN IF THE CAP DOES BREAK...AS SUGGESTED BY BUFKIT NAM/RAP GUIDANCE...NOT MUCH INSTABILITY...AND NOT UNTIL AFTER 18Z. WITH THE SHORT WAVE ENERGY WELL WEST AND NORTH OF THE FORECAST AREA...LITTLE TO AIDE IN THE FORCING TODAY. AXIS OF POOLED MOISTURE AND LOW LEVEL CONVERGENCE ALONG THE WEAK BOUNDARY PIVOTS NORTHEAST TONIGHT AND WILL EXTEND FROM OHIO INTO EASTERN NORTH CAROLINA BY SATURDAY MORNING. WILL HAVE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS IN THE EXTREME SOUTHWEST COUNTY WARNING AREA. AREAL COVERAGE OF PRECIPITATION SHOULD ONLY BE ISOLATED TO SCATTERED. STORM MOTION WOULD BRING THE STORMS INTO SOUTHEAST WEST VIRGINIA AND POSSIBLY THE NEW RIVER VALLEY AROUND 00Z. BUT NOT MUCH INSTABILITY LEFT BY THAT TIME. SOUTHEAST WINDS AT THE SURFACE THROUGH LOW LEVELS...BRING 850-1000MB RELATIVE HUMIDITY UP TODAY AND BY TONIGHT LOW CLOUDS ARE EXPECTED TO ADVANCE TOWARD THE EAST SIDE OF THE APPALACHIANS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 310 AM EDT FRIDAY... UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A SOUTHERN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL STREAK OVER THE GULF COAST STATES AND ACROSS THE WESTERN SLOPES OF THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SOUTH-SOUTHEAST FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN THE EAST...MAINLY FROM THE EASTERN WV PANHANDLE SOUTHEAST TOWARD THE TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST WITH MID 80S WEST. SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER EVENING STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT LEAST SLIGHT CHANCE INTO THE MOUNTAINS LATE. SUNDAY LOOKS ACTIVE AS THE SHORTWAVE AXIS SHIFTS ACROSS KY INTO NORTHERN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR WHERE A FEW STORMS COULD PRODUCE GUSTY WINDS. THE SHORT WAVE AXIS SLOWLY SHIFTS TO THE EAST AND WITH A LEE TROUGH...CONVECTION FIRES LATE IN THE AFTERNOON AND MAY REMAIN OVER SOUTHSIDE UNTIL MIDNIGHT. HIGHS SUNDAY WILL RANGE FROM THE UPPER 70S MOUNTAINS TO UPPER 80S TOWARDS SOUTHSIDE. OVERALL...LABOR DAY WEEKEND LOOKING VERY WARM/HOT/HUMID. SATURDAY NOT TOO BAD RAIN WISE...BUT STAY COOL WHILE DRINKING PLENTY OF WATER IF OUTDOORS. SUNDAY APPEARS POOR FOR OUTDOOR ACTIVITIES. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE GULF COAST STATES BY THE END OF THE FORECAST PERIOD. SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO AND THROUGH THE GREAT LAKES INTO NEW ENGLAND. HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED OVER THE AREA. GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME. PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64 BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR. PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER 80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 745 AM EDT FRIDAY... A STATIONARY FRONT EXTENDED FROM AROUND NORTH CAROLINA TO MISSOURI. THIS FRONT WILL MOVE LITTLE TODAY THEN WILL PUSH NORTH TONIGHT...INTO THE OHIO VALLEY BY SATURDAY MORNING. STRATOCUMULUS HAD FILLED IN OVER SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA EARLY THIS MORNING WITH MVFR TO LOW END VFR CEILINGS. EXPECT THESE CLOUDS TO BECOME SCATTERED BY THIS AFTERNOON. THE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING WILL JUST SOUTH OF KBLF AND KBCB. STORM MOTION MAY TAKE THE STORMS CLOSE TO THESE AIRPORTS AROUND 00Z/8PM...BUT PROBABILITY IS TOO LOW AT THIS TIME TO MENTION IN THE TAFS. MODELS SHOWED HIGH AMOUNTS OF LOW NEAR THE SURFACE ALONG AND EAST OF THE BLUE RIDGE LATE TONIGHT. HIGH CONFIDENCE OF AT LEAST MVFR CEILINGS AT KLYH AND KDAN AFTER 06Z/2AM. NOT AS MUCH A SURE THING AT KROA...BUT STILL CONFIDENT ENOUGH TO ADD MVFR CEILINGS TO THE TAF. IT IS POSSIBLE THAT CEILINGS MAY LOWER ALL THE WAY TO IFR LEVELS BEFORE THE 12Z/8AM END OF THE TAF PERIOD AS THIS STRATUS EXPANDS TO THE WEST. EXTENDED DISCUSSION... WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION AGAIN ON SATURDAY...MAINLY DURING THE LATE AFTERNOON AND EARLY EVENING. SHOULD ONE OF THESE STORMS DEVELOP NEAR A TAF LOCATION IT COULD RESULT IN A BRIEF PERIOD OF SUB VFR CONDITIONS. AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND MONDAY. SHOWER COVERAGE SUNDAY THROUGH TUESDAY IS EXPECTED TO BE MORE WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY. && .EQUIPMENT... AS OF 730 AM EDT FRIDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...WERT AVIATION...AMS/CF EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1253 PM EDT FRI AUG 29 2014 .SYNOPSIS... A WEAK FRONT WILL BE STATIONARY FROM NORTH CAROLINA TO MISSOURI TODAY. THIS FRONT WILL LIFT NORTH INTO THE OHIO VALLEY TONIGHT. A STRONGER SYSTEM WILL BRING A BETTER THREAT FOR SHOWERS AND STORMS FOR SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1247 PM EDT FRIDAY... LATEST LAPS DATA ARE SHOWING SURFACE BASED LI OF -2 TO -3 AND CAPS AROUND 500 J/GS ACROSS TAZEWELL AND SMYTH COUNTIES. HIGHER VALUES EXIST WEST OF THE FORECAST AREA IN SOUTHERN WEST VIRGINIA AND NORTHEAST TENNESSEE. NO SHOWERS DETECTED YET ON REGIONAL RADARS IN THAT REGION...BUT VISIBLE SATELLITE IMAGERY IS STARTING TO SHOW THE DEVELOPMENT OF CUMULUS CLOUDS...SO AM NOT EXPECTING TOO LONG OF WAIT FOR THE FIRST SHOWERS TO DEVELOP. LATEST HRRR AND RNK WRF-ARW ARE ON TARGET FOR ABOUT A 18-19Z/2PM-3PM INITIATION TIME. THE OTHER AREA OF THE REGION THAT WE HAVE BEEN WATCHING FOR DEVELOPMENT IS SOUTHSIDE VIRGINIA AND NEIGHBORING NORTH CENTRAL NORTH CAROLINA. THIS REGION HAS HAD DECENT CLOUD COVER OVER IT FOR THE MORNING...AND NOW THE EARLY AFTERNOON. LAPS...AS EXPECTED...STILL HAS THE AREA STABLE. FOR OUR FORECAST...HAVE DELAYED THE ONSET OF ANY ISOLATED SHOWER OR THUNDERSTORM ACTIVITY UNTIL LATER IN THE AFTERNOON...PERHAPS STARTING AROUND OR AFTER 21Z/5PM. HAVE ALSO LOWERED EXPECTED HIGH TEMPERATURES IN THIS AREA BY A COUPLE OF DEGREES THANKS TO THE CLOUDS. HAVE RAISE FORECAST HIGHS IN THE FAR WESTERN PARTS OF THE ARE BASED UPON CURRENT TEMPERATURES AND CONTINUED WARMING TREND THROUGH THE AFTERNOON. AS OF 947 AM EDT FRIDAY... LATEST MESOSCALE MODELS STILL OFFERING BEST CHANCE FOR CONVECTION TODAY TO BE ACROSS THE WESTERN QUARTER OF THE REGION. LATEST LAPS DATA SHOW SURFACE BASED LI VALUES HAVE JUST DROPPED BELOW ZERO AND A FEW HUNDRED SURFACE BASED CAPE HAVE DEVELOPED IN WESTERN TAZEWELL AND SMYTH COUNTIES. THIS AREA AND THE SURROUNDING AREA IS EXPECTED TO BECOME MORE UNSTABLE WITH THE HEATING OF THE AFTERNOON. INITIAL CONVECTION TIME IS EXPECTED TO BE SOMEWHERE BETWEEN 17Z-18Z/1PM-2PM IN THIS REGION AND MAINTAIN THROUGH THE AFTERNOON. ANOTHER AREA WE ARE STILL WATCHING IS SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH CAROLINA. WHILE STILL STABLE AT THE SURFACE...THIS AREA IS EXPECTED TO BECOME UNSTABLE THIS AFTERNOON IN PROXIMITY TO THE STALLED FRONTAL BOUNDARY. NO MAJOR CHANGES TO THE FORECAST. AS OF 400 AM EDT FRIDAY... STATIONARY FRONT TRAILED FROM NORTHEAST NORTH CAROLINA TO NORTH CENTRAL TENNESSEE EARLY THIS MORNING. ALONG THE BOUNDARY AND WEST OF THE BLUE RIDGE MODELS WERE SHOWING A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING. WILL BE STARTING OFF THE DAY CAPPED. EVEN IF THE CAP DOES BREAK...AS SUGGESTED BY BUFKIT NAM/RAP GUIDANCE...NOT MUCH INSTABILITY...AND NOT UNTIL AFTER 18Z. WITH THE SHORT WAVE ENERGY WELL WEST AND NORTH OF THE FORECAST AREA...LITTLE TO AIDE IN THE FORCING TODAY. AXIS OF POOLED MOISTURE AND LOW LEVEL CONVERGENCE ALONG THE WEAK BOUNDARY PIVOTS NORTHEAST TONIGHT AND WILL EXTEND FROM OHIO INTO EASTERN NORTH CAROLINA BY SATURDAY MORNING. WILL HAVE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS IN THE EXTREME SOUTHWEST COUNTY WARNING AREA. AREAL COVERAGE OF PRECIPITATION SHOULD ONLY BE ISOLATED TO SCATTERED. STORM MOTION WOULD BRING THE STORMS INTO SOUTHEAST WEST VIRGINIA AND POSSIBLY THE NEW RIVER VALLEY AROUND 00Z. BUT NOT MUCH INSTABILITY LEFT BY THAT TIME. SOUTHEAST WINDS AT THE SURFACE THROUGH LOW LEVELS...BRING 850-1000MB RELATIVE HUMIDITY UP TODAY AND BY TONIGHT LOW CLOUDS ARE EXPECTED TO ADVANCE TOWARD THE EAST SIDE OF THE APPALACHIANS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 310 AM EDT FRIDAY... UPPER RIDGE EXPECTED TO SHIFT EAST AS STRONGER UPPER TROUGH MOVES FROM THE UPPER MIDWEST INTO THE GREAT LAKES. MODELS AGREE THAT A SOUTHERN STREAM UPPER SHORTWAVE WITH ENHANCEMENT IN THE JET WILL STREAK OVER THE GULF COAST STATES AND ACROSS THE WESTERN SLOPES OF THE APPALACHIANS SUNDAY. FOR SATURDAY THOUGH...MAINLY LOOKING WEAK FLOW ALOFT WITH SOME CONVERGENCE ACROSS THE MTNS PER SOUTH-SOUTHEAST FLOW. MODELS ARE FAVORING A BIT OF CONVECTION WITH THE LEE TROUGH IN THE EAST...MAINLY FROM THE EASTERN WV PANHANDLE SOUTHEAST TOWARD THE TIDEWATER. THINK THE AIRMASS WILL BE UNSTABLE AND MOIST ENOUGH TO TRIGGER A FEW STORMS BUT OVERALL UPPER SUPPORT IS LACKING SO ONLY SEEING ISOLATED COVERAGE OVER THE MTNS AND NORTH OF A ROANOKE TO DANVILLE LINE. MORE SUN SATURDAY WILL BRING TEMPS TOWARD 90 OUT EAST WITH MID 80S WEST. SAT NIGHT...MAIN AXIS OF CONVECTION WILL RUN FROM MS-KY...WITH LITTLE TO NO CHANCE OF SHOWERS EAST OF THE BLUE RIDGE AFTER EVENING STORMS WANE. WITH THE UPPER SUPPORT TRACKING CLOSER WILL HAVE AT LEAST SLIGHT CHANCE INTO THE MOUNTAINS LATE. SUNDAY LOOKS ACTIVE AS THE SHORTWAVE AXIS SHIFTS ACROSS KY INTO NORTHERN WV...WITH STRONG CONVERGENCE AND LIFT. WILL SEE HIGH CHANCE/LIKELY POPS. LOOKS LIKE CLOUD COVER COULD ARRIVE SOON ENOUGH TO KEEP INSTABILITY LOWER...BUT ENOUGH UPPER SUPPORT/SHEAR WHERE A FEW STORMS COULD PRODUCE GUSTY WINDS. THE SHORT WAVE AXIS SLOWLY SHIFTS TO THE EAST AND WITH A LEE TROUGH...CONVECTION FIRES LATE IN THE AFTERNOON AND MAY REMAIN OVER SOUTHSIDE UNTIL MIDNIGHT. HIGHS SUNDAY WILL RANGE FROM THE UPPER 70S MOUNTAINS TO UPPER 80S TOWARDS SOUTHSIDE. OVERALL...LABOR DAY WEEKEND LOOKING VERY WARM/HOT/HUMID. SATURDAY NOT TOO BAD RAIN WISE...BUT STAY COOL WHILE DRINKING PLENTY OF WATER IF OUTDOORS. SUNDAY APPEARS POOR FOR OUTDOOR ACTIVITIES. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM EDT THURSDAY... MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A MEAN UPPER RIDGE THAT WILL INITIALLY RESIDE ALONG AND OFF THE SOUTHEAST COAST...WHICH GRADUALLY RETROGRESSES AND EXPANDS WESTWARD INTO THE GULF COAST STATES BY THE END OF THE FORECAST PERIOD. SOUTHEASTERN RIDGE WILL INITIALLY BE STRONG ENOUGH TO DEFLECT ANY NORTHERN STREAM ENERGY AWAY FROM THE BLACKSBURG FORECAST AREA...WITH MAIN BAROCLINIC ZONE REMAINING FROM THE NORTHERN PLAINS EAST INTO AND THROUGH THE GREAT LAKES INTO NEW ENGLAND. HOWEVER...TAP OF TROPICAL MOISTURE RIDING AROUND PERIPHERY OF SOUTHEASTERN RIDGE LIKELY TO REMAIN OVER/NEAR THE BLACKSBURG FORECAST AREA THROUGH AT LEAST MONDAY OR MONDAY NIGHT...MAINTAINING THREAT FOR MAINLY DIURNALLY DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS...SOME OF WHICH MAY BE ACCOMPANIED BY LOCALLY HEAVY RAIN CONSIDERING RELATIVELY HIGH PRECIPITABLE WATER VALUES EXPECTED OVER THE AREA. GRADUAL RETROGRESSION OF UPPER RIDGE INTO NORTHERN GULF COAST REGION DURING THE MIDWEEK PERIOD SHOULD BE SUFFICIENT TO ALLOW WINDS ALOFT TO VEER SUCH THAT INFLUENCE OF TROPICAL MOISTURE TAP GRADUALLY WANES...ONLY TO BE REPLACED BY MORE AGGRESSIVE SOUTHWARD INTRUSION OF NORTHERN STREAM ENERGY AND ASSOCIATED SCATTERED SHOWERS/STORMS IN ADVANCE OF AN ACCOMPANYING DECAYING COOL FRONT INTO THE MID APPALACHIAN AND MID ATLANTIC REGION IN TUESDAY-WEDNESDAY TIMEFRAME. PUSH OF POST-FRONTAL SLIGHTLY DRIER AIR MAY BE STRONG ENOUGH TO REDUCE THREAT FOR PRECIPITATION ACROSS AREAS NORTH OF INTERSTATE 64 BY THURSDAY...BUT WITH AT LEAST A CHANCE THREAT FOR SHOWERS/STORMS REDEVELOPING BY AFTERNOON ACROSS THE SOUTHWESTERN MOUNTAINS CLOSER TO DECAYING FRONTAL BOUNDARY AND PROXIMITY TO HIGHER THETA-E AIR. PLENTY OF CLOUD COVER AND DEWPOINTS PRIMARILY IN THE 60S SHOULD ENSURE THAT TEMPERATURES REMAIN CLOSE TO SEASONAL AVERAGES...MAINLY MID 70S TO LOWER 80S ACROSS THE HIGHER ELEVATIONS BY DAY WITH UPPER 80S ACROSS THE PIEDMONT...WITH MAINLY 60S AT NIGHT. INTRUSION OF SLIGHTLY COOLER/DRIER POST-FRONTAL AIR FROM THE NORTHEAST MAY ALLOW TEMPERATURES TO BE A FEW DEGREES COOLER ON THURSDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 745 AM EDT FRIDAY... A STATIONARY FRONT EXTENDED FROM AROUND NORTH CAROLINA TO MISSOURI. THIS FRONT WILL MOVE LITTLE TODAY THEN WILL PUSH NORTH TONIGHT...INTO THE OHIO VALLEY BY SATURDAY MORNING. STRATOCUMULUS HAD FILLED IN OVER SOUTHERN VIRGINIA AND NORTHERN NORTH CAROLINA EARLY THIS MORNING WITH MVFR TO LOW END VFR CEILINGS. EXPECT THESE CLOUDS TO BECOME SCATTERED BY THIS AFTERNOON. THE BEST PROBABILITY OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING WILL JUST SOUTH OF KBLF AND KBCB. STORM MOTION MAY TAKE THE STORMS CLOSE TO THESE AIRPORTS AROUND 00Z/8PM...BUT PROBABILITY IS TOO LOW AT THIS TIME TO MENTION IN THE TAFS. MODELS SHOWED HIGH AMOUNTS OF LOW NEAR THE SURFACE ALONG AND EAST OF THE BLUE RIDGE LATE TONIGHT. HIGH CONFIDENCE OF AT LEAST MVFR CEILINGS AT KLYH AND KDAN AFTER 06Z/2AM. NOT AS MUCH A SURE THING AT KROA...BUT STILL CONFIDENT ENOUGH TO ADD MVFR CEILINGS TO THE TAF. IT IS POSSIBLE THAT CEILINGS MAY LOWER ALL THE WAY TO IFR LEVELS BEFORE THE 12Z/8AM END OF THE TAF PERIOD AS THIS STRATUS EXPANDS TO THE WEST. EXTENDED DISCUSSION... WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL AFFECT THE REGION AGAIN ON SATURDAY...MAINLY DURING THE LATE AFTERNOON AND EARLY EVENING. SHOULD ONE OF THESE STORMS DEVELOP NEAR A TAF LOCATION IT COULD RESULT IN A BRIEF PERIOD OF SUB VFR CONDITIONS. AN AREA OF LOW PRESSURE IS FORECAST TO MOVE THROUGH THE GREAT LAKES SATURDAY NIGHT AND SUNDAY...THE ASSOCIATED COLD FRONT TRAILING SOUTH AND MOVING ACROSS THE OHIO/TN VALLEYS. SHOWERS AND THUNDERSTORMS WILL LIKELY BE ASSOCIATED WITH THIS FRONT...THIS ACTIVITY SPREADING EAST INTO THE CENTRAL APPALACHIANS SUNDAY AND MONDAY. SHOWER COVERAGE SUNDAY THROUGH TUESDAY IS EXPECTED TO BE MORE WIDESPREAD AS COMPARED TO FRIDAY AND SATURDAY. && .EQUIPMENT... AS OF 730 AM EDT FRIDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WILL BE OUT OF SERVICE UNTIL FURTHER NOTICE. A PART HAS BEEN BACK-ORDERED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...WERT AVIATION...AMS/CF EQUIPMENT...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1256 PM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 1105 AM CDT FRI AUG 29 2014 RADAR IS PRETTY QUITE AROUND THE FORECAST AREA WITH WEATHER MAINLY FURTHER WEST. LATEST VISIBLE IMAGERY SHOWING A GENERAL CLEARING AND DEEPER MIXING TREND OVER THE SOUTHERN FORECAST AREA. LOWER STRATOCUMULUS IS IN PLACE UNDER THE CAPPING INVERSION OVER NORTHEAST IOWA INTO CENTRAL WI AND THIS IS ERODING FROM THE SOUTH AS DEEPER MIXING OCCURS /EVIDENCED BY MORE GUSTING IN THE OBSERVATIONS ALONG HIGHWAY 20 IN IA AND INTO NORTHCENTRAL IA/. A BIT FURTHER NORTH ALONG THE I-94 CORRIDOR LIES SOME CONVERGENT FLOW ALONG THE WARM FRONT WITH A WIND SHIFT FROM SE TO S/SW. SOME FOG AND LOWER VISIBILITY IS SEEN NORTH OF I-94 TOO IN CLASSIC WARM FRONT SCENARIO. EXPECT THE NORTHWARD TREND TO CONTINUE OF THE WARM FRONT WITH SOME SMALL SHOWERS POSSIBLE ALONG/NORTH OF THE WARM FRONT THROUGH MID DAY UNTIL S/SWRLY WINDS TAKE HOLD. THIS SHOULD PROVIDE A DRIER EARLY AFTERNOON AT LEAST. AREA SHOULD THEN BE IN A DESTABILIZING WARM SECTOR WITH WEAK CAPPING AFTER 3 PM. THE DIFFICULT ISSUE TO TACKLE RIGHT NOW IS WHAT TYPE OF FORCING WILL BE PRESENT FOR THE HIGH STORM CHANCES THE FORECAST HAD/HAS FROM 3-6 PM. BELIEVE THE MAIN FORCING FOR TSRA WILL ARRIVE VIA CURRENT KANSAS SHORTWAVE TROUGH LIFTING N/NE INTO MN TONIGHT. WHILE THE NORTHERN STREAM FRONT WILL SHIFT SEWRD /NOW FROM ROUGHLY MSP-DLH/ TO PROVIDE CONVERGENCE...IT STILL REMAINS NORTHWEST UNTIL EVENING FROM CONSENSUS SHORT TERM MODEL GUIDANCE. THIS SEEMS VERY REASONABLE BASED ON CURRENT OBSERVATIONAL DATA. SO, WARM SECTOR SOUTHERLY FLOW IS NOT VERY CONVERGENT FOR STORM INITIATION THIS AFTERNOON EXCEPT MAYBE IN THE VERY FAR WEST FORECAST AREA. ALL OF THE TRENDS FOR WEATHER ARE VERY LATE AFTERNOON WEST OF MISS RIVER AND IN THE EVENING EAST OF THE RIVER. SO...HAVE DRIED OUT THE FORECAST THROUGH MID AFTERNOON AREA-WIDE. BELIEVE THE TREND WILL BE TO CONCENTRATE ON LOW MOVING NORTHWARD FROM KS...AND THIS WOULD BE TO DELAY THE RAIN/STORM ONSET /FURTHER/ INTO LATER TODAY AND MAINLY THIS EVENING. SO...THINKING THAT ANOTHER UPDATE TO DELAY OUR CURRENT FORECAST MAY BE NEEDED IN EARLY AFTERNOON. SEVERE STORM CHANCES ARE STILL AROUND...IF NOT GROWING WITH WARM SECTOR DESTABILIZING...WEAK CAP BY EVENING...AND FORCING MOVING IN. MLCAPES IN THE EARLY EVENING SEEM LIKE THEY SHOULD BE IN THE 1000-1500 J/KG RANGE. 0-3KM BULK SHEAR IN THE 20-25KT RANGE NOT SUPER IMPRESSIVE...SEEMS TO PROVIDE ISOLATED WIND THREATS VIA BOWING SEGMENTS ORIENTED NW-SE. THESE MAY HAVE LIMITED LIFE CYCLES AND MAKE LEAD TIME TOUGH FOR ANY WARNINGS. WITH MORE FORCING/DYNAMICS WEST OF MISS RIVER INTO KEAU AREA...THAT SEEMS TO BE THE PREFERRED AREA FOR THIS ISOLATED ACTIVITY. HEAVY RAIN IS ALSO A THREAT AND STORM TRAINING COULD OCCUR IN THAT SAME AREA...BUT THEN IT SHOULD TURN PROGRESSIVE MID-EVENING AND INTO WI. AS THE WEATHER SHIFTS EASTWARD...THREATS DIMINISH TO LIGHTNING WITH PROGRESSIVE NATURE TO RAIN AND DIMINISHING INSTABILITY. MAYBE THE NUMBER ONE THREAT IS LIGHTNING FOR FRIDAY NIGHT FOOTBALL && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD. LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE 29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30 TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS MORNING. THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF 1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80 PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS. ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES. HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS THE FAR WESTERN SECTIONS SUNDAY AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE 500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80 PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60 PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND 40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN CHANCES WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1256 PM CDT FRI AUG 29 2014 INSTABILITY IS GROWING ACROSS THE TAF SITES THIS AFTERNOON AND LATER IN THE DAY AND THROUGH THE EVENING...THUNDERSTORMS AND RAIN WILL DEVELOP. TRIED TO CONCENTRATE THE TSRA CHANCES INTO A 3 HOUR WINDOW THIS EVENING. HEAVIER RAINFALL RATES WILL MEAN MORE LIKELY IFR CONDITIONS FROM ANY TSRA...ESPECIALLY WITH INSTABILITY BUILDING AND THE AIR MASS CONTAINING RICH MOISTURE. THERE WILL BE A VERY MOIST BOUNDARY LAYER BY SUNRISE WITH LIGHT WINDS. IT SEEMS THE PROBABILITIES FOR LIFR CIGS ARE INCREASING THROUGH THE OVERNIGHT SO CONTINUED THE TREND OF LOW CIGS AND FOG SATURDAY MORNING. && .HYDROLOGY... ISSUED AT 309 AM CDT FRI AUG 29 2014 PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF 3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN PRODUCERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...BAUMGARDT SHORT TERM...04 LONG TERM...04 AVIATION...BAUMGARDT HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 AM CDT FRI AUG 29 2014 .UPDATE... ISSUED AT 1105 AM CDT FRI AUG 29 2014 RADAR IS PRETTY QUITE AROUND THE FORECAST AREA WITH WEATHER MAINLY FURTHER WEST. LATEST VISIBLE IMAGERY SHOWING A GENERAL CLEARING AND DEEPER MIXING TREND OVER THE SOUTHERN FORECAST AREA. LOWER STRATOCUMULUS IS IN PLACE UNDER THE CAPPING INVERSION OVER NORTHEAST IOWA INTO CENTRAL WI AND THIS IS ERODING FROM THE SOUTH AS DEEPER MIXING OCCURS /EVIDENCED BY MORE GUSTING IN THE OBSERVATIONS ALONG HIGHWAY 20 IN IA AND INTO NORTHCENTRAL IA/. A BIT FURTHER NORTH ALONG THE I-94 CORRIDOR LIES SOME CONVERGENT FLOW ALONG THE WARM FRONT WITH A WIND SHIFT FROM SE TO S/SW. SOME FOG AND LOWER VISIBILITY IS SEEN NORTH OF I-94 TOO IN CLASSIC WARM FRONT SCENARIO. EXPECT THE NORTHWARD TREND TO CONTINUE OF THE WARM FRONT WITH SOME SMALL SHOWERS POSSIBLE ALONG/NORTH OF THE WARM FRONT THROUGH MID DAY UNTIL S/SWRLY WINDS TAKE HOLD. THIS SHOULD PROVIDE A DRIER EARLY AFTERNOON AT LEAST. AREA SHOULD THEN BE IN A DESTABILIZING WARM SECTOR WITH WEAK CAPPING AFTER 3 PM. THE DIFFICULT ISSUE TO TACKLE RIGHT NOW IS WHAT TYPE OF FORCING WILL BE PRESENT FOR THE HIGH STORM CHANCES THE FORECAST HAD/HAS FROM 3-6 PM. BELIEVE THE MAIN FORCING FOR TSRA WILL ARRIVE VIA CURRENT KANSAS SHORTWAVE TROUGH LIFTING N/NE INTO MN TONIGHT. WHILE THE NORTHERN STREAM FRONT WILL SHIFT SEWRD /NOW FROM ROUGHLY MSP-DLH/ TO PROVIDE CONVERGENCE...IT STILL REMAINS NORTHWEST UNTIL EVENING FROM CONSENSUS SHORT TERM MODEL GUIDANCE. THIS SEEMS VERY REASONABLE BASED ON CURRENT OBSERVATIONAL DATA. SO, WARM SECTOR SOUTHERLY FLOW IS NOT VERY CONVERGENT FOR STORM INITIATION THIS AFTERNOON EXCEPT MAYBE IN THE VERY FAR WEST FORECAST AREA. ALL OF THE TRENDS FOR WEATHER ARE VERY LATE AFTERNOON WEST OF MISS RIVER AND IN THE EVENING EAST OF THE RIVER. SO...HAVE DRIED OUT THE FORECAST THROUGH MID AFTERNOON AREA-WIDE. BELIEVE THE TREND WILL BE TO CONCENTRATE ON LOW MOVING NORTHWARD FROM KS...AND THIS WOULD BE TO DELAY THE RAIN/STORM ONSET /FURTHER/ INTO LATER TODAY AND MAINLY THIS EVENING. SO...THINKING THAT ANOTHER UPDATE TO DELAY OUR CURRENT FORECAST MAY BE NEEDED IN EARLY AFTERNOON. SEVERE STORM CHANCES ARE STILL AROUND...IF NOT GROWING WITH WARM SECTOR DESTABILIZING...WEAK CAP BY EVENING...AND FORCING MOVING IN. MLCAPES IN THE EARLY EVENING SEEM LIKE THEY SHOULD BE IN THE 1000-1500 J/KG RANGE. 0-3KM BULK SHEAR IN THE 20-25KT RANGE NOT SUPER IMPRESSIVE...SEEMS TO PROVIDE ISOLATED WIND THREATS VIA BOWING SEGMENTS ORIENTED NW-SE. THESE MAY HAVE LIMITED LIFE CYCLES AND MAKE LEAD TIME TOUGH FOR ANY WARNINGS. WITH MORE FORCING/DYNAMICS WEST OF MISS RIVER INTO KEAU AREA...THAT SEEMS TO BE THE PREFERRED AREA FOR THIS ISOLATED ACTIVITY. HEAVY RAIN IS ALSO A THREAT AND STORM TRAINING COULD OCCUR IN THAT SAME AREA...BUT THEN IT SHOULD TURN PROGRESSIVE MID-EVENING AND INTO WI. AS THE WEATHER SHIFTS EASTWARD...THREATS DIMINISH TO LIGHTNING WITH PROGRESSIVE NATURE TO RAIN AND DIMINISHING INSTABILITY. MAYBE THE NUMBER ONE THREAT IS LIGHTNING FOR FRIDAY NIGHT FOOTBALL GAMES. WILL TRY TO PROVIDE MORE UPDATES ON TIMING TODAY. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 THE MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD. LOCAL AND REGIONAL RADARS SHOWING AN AREA OF SHOWERS AND STORMS ACROSS SOUTHERN MINNESOTA INTO CENTRAL IOWA. THIS ACTIVITY HAS BEEN MOVING NORTHEAST AND THE 29.00Z HRRR SEEMED TO HAVE A DECENT HANDLE ON THIS. IT SUGGESTS THAT IT WILL CONTINUE TO MOVE NORTHEAST INTO THE AREA AND MAY SHOW A DIMINISHING TREND AS IT OUTRUNS THE AVAILABLE CAPE. THE 29.06Z RAP ANALYSIS SUGGESTED THERE WAS AROUND 250 J/KG OF MU CAPE OVER THE WESTERN SECTIONS WITH THIS DROPPING TO NEAR ZERO OVER WESTERN AND CENTRAL WISCONSIN. WHILE THE THUNDER MAY DIMINISH AS THE SYSTEM CONTINUES TO WORK NORTHEAST...THE AREAL COVERAGE MAY NOT CHANGE MUCH AS THE 29.05Z RAP INDICATES THE ACTIVITY IS ON THE NOSE OF THE 850 MB LOW LEVEL JET AND THIS MAINTAINS ITS INTENSITY AS IT LIFTS NORTHEAST THROUGH THE AREA FOR THE REMAINDER OF THE NIGHT. PLAN TO START THE DAY WITH AT LEAST A 70 PERCENT CHANCE OF RAIN OVER MUCH OF CENTRAL INTO PARTS OF WESTERN WISCONSIN AND THEN DIMINISH THESE DOWN TO 30 TO 50 PERCENT BY LATE MORNING AS THE AREA GETS IN BETWEEN SYSTEMS. BOTH THE HRRR AND 29.00Z HI-RES ARW SUGGEST MOST IF NOT ALL OF THE AREA COULD BE RAIN FREE FOR A SHORT WHILE LATE THIS MORNING. THIS DRY PERIOD WILL NOT LAST VERY LONG AS THE MEAN LONG WAVE TROUGH WILL START TO APPROACH FROM THE WEST IN THE AFTERNOON WITH A STRONG SHORT WAVE TROUGH EMBEDDED IN THE FLOW. THIS IS EXPECTED TO PRODUCE WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER DURING THE AFTERNOON AND EVENING. THE 29.00Z NAM SUGGEST THERE COULD ALSO BE SOME COUPLED JET DYNAMICS FROM THE RIGHT ENTRANCE REGION OF THE MAIN JET CORE ACROSS THE NORTHERN GREAT LAKES INTO SOUTHEAST CANADA AND FROM THE LEFT EXIT REGION OF A SECONDARY JET ROUNDING THE BASE OF THE LONG WAVE TROUGH. THE CAPE WILL INCREASE IN THE AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST TWO-THIRDS OF THE FORECAST AREA...WHERE THE NAM INDICATES THE POTENTIAL OF 1500-2500 J/KG OF ML CAPE. THIS MAY BE A LITTLE ON THE HIGH SIDE AS IT IS SHOWING WIDESPREAD LOWER 70S DEW POINTS WHEN THESE MAY ONLY BE IN THE UPPER 60S TO AROUND 70. NONE THE LESS...EXPECT TO SEE AN INCREASE IN THE ACTIVITY DURING THE AFTERNOON INTO THE EVENING AND WILL PUSH THE RAIN CHANCES BACK UP INTO THE 70 TO 80 PERCENT RANGE BY EVENING WHEN THE FORCING IS THE BEST. THE ACTIVITY SHOULD START TO MOVE OUT OF THE AREA LATE TONIGHT INTO SATURDAY MORNING AND THEN END DURING THE AFTERNOON AS THE LONG WAVE TROUGH MOVES PAST THE AREA. IF THE CAPE ADVERTISED BY THE MODELS CAN BE REALIZED...THEN THERE COULD SOME POTENTIAL FOR SEVERE STORMS. THE 0-3KM BULK SHEAR SHOULD BE IN THE 30 TO 40 KNOT RANGE WHICH WOULD BE ENOUGH TO SUPPORT SOME STRONG WINDS. ONCE THE RAIN ENDS SATURDAY...IT APPEARS THAT SOME WEAK RIDGING WILL BUILD OVER THE AREA FOR A DRY SATURDAY NIGHT. THIS RIDGING WILL THEN QUICKLY BE PUSHED OUT OF THE AREA SUNDAY AS YET ANOTHER LONG WAVE TROUGH STARTS TO COME IN FROM THE NORTHERN ROCKIES. HOWEVER...IT APPEARS THE TIMING OF THIS SYSTEM WOULD BE SUCH THAT THERE WILL ONLY BE A SMALL CHANCE FOR SOME ADDITIONAL RAINS ACROSS THE FAR WESTERN SECTIONS SUNDAY AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 309 AM CDT FRI AUG 29 2014 PRETTY DECENT AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THAT THIS NEXT SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND MONDAY. THE 29.00Z ECMWF AND GFS BOTH INDICATE THE EMBEDDED SHORT WAVE TROUGH COULD PRODUCE MODERATE TO STRONG PV ADVECTION IN THE 500-300 MB LAYER WHILE THE 29.00Z GEM SHOWS WEAK TO MODERATE PV ADVECTION. ALL THREE MODELS DO SHOW THE COLD FRONT WITH THIS SYSTEM PASSING THROUGH LATE SUNDAY NIGHT INTO MONDAY MORNING WITH A SOLID SHIELD OF RAIN ALONG AND AHEAD OF IT. WILL SHOW 60 TO 80 PERCENT RAIN CHANCES SUNDAY NIGHT FROM EAST TO WEST AND 30 TO 60 PERCENT CHANCES MONDAY. HOWEVER...IF THE TIMING OF THE SYSTEM REMAINS THE SAME...THE MONDAY RAIN CHANCES MAY HAVE TO BE INCREASED...ESPECIALLY IN THE MORNING. THE TIMING OF THE FRONT IS NOT IDEAL FOR SEVERE CHANCES...BUT THE GFS DOES SHOW 500-1000 J/KG OF ML CAPE PERSISTING SUNDAY NIGHT AHEAD OF THE FRONT WITH AROUND 40 KNOTS OF 0-6KM SHEAR. THIS WOULD BE SUFFICIENT TO SUPPORT SOME STRONGER STORMS THAT COULD PRODUCE SOME STRONG WINDS. ANOTHER COLD FRONT LOOKS TO MOVE THROUGH LATE IN THE PERIOD FOR ADDITIONAL RAIN CHANCES WEDNESDAY NIGHT INTO THURSDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 700 AM CDT FRI AUG 29 2014 RAIN AREA SHIFTING NORTHWARD SO FEEL ANY RAIN WILL BE OUT OF THE AIRFIELDS BY MID-MORNING. AS UPPER SYSTEM CONTINUES TO MOVE TOWARD THE REGION...LOOKING LIKE THE DRY SLOT WILL PROVIDE FOR SOME PARTIAL SUNSHINE FOR A TIME LATE THIS MORNING. BUT THAT WILL ONLY HELP TO DESTABLIZE THE ATMOSPHERE...LEADING TO MORE CONVECTIVE DEVELOPMENT. VARIOUS MESOSCALE MODEL SOLUTIONS SUGGEST SCATTERED CONVECTION DEVELOPS IN THE WARM AND MOIST AIR...WITH A MORE FOCUSED BAND OF STORMS WHERE SOME FRONTAL CONVERGENCE LOOKS TO EXIST. THIS LOOKS TO BE PRIMARILY NEAR THE KRST AIRFIELD. EITHER WAY...BOTH TAF FORECASTS WILL INCLUDE A TSRA RISK FOR SEVERAL HOURS FROM THE AFTERNOON INTO EVENING. ONCE THE RAIN MOVES THROUGH BY MIDNIGHT...LOW STRATUS AND FOG LOOK TO BE A GOOD BET...WITH LIFR CONDITIONS ANTICIPATED. && .HYDROLOGY... ISSUED AT 309 AM CDT FRI AUG 29 2014 PLAN TO CONTINUE WITH THE HYDROLOGIC OUTLOOK THIS MORNING. NOT OVERLY CONCERNED ABOUT ANY FLOODING THREATS AS THE RAIN THURSDAY DID NOT TURN OUT TO BE AS HEAVY AS EXPECTED AND THE CURRENT FORECAST IS FOR ANOTHER 1 TO 1.5 INCHES THROUGH SATURDAY. WILL LIKELY BE SOME LOCALLY HIGHER AMOUNTS THOUGH AS THE CONDITIONS ARE STILL IN PLACE FOR SOME HEAVY RAIN TO OCCUR. PRECIPITABLE WATERS WILL REMAIN IN THE 1.5 TO 2 INCH RANGE WITH WARM CLOUD DEPTHS OF 3.5 TO 4 KM WHICH WILL HELP TO MAKE THE CONVECTION EFFICIENT RAIN PRODUCERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...BAUMGARDT SHORT TERM...04 LONG TERM...04 AVIATION...MW HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
437 PM MDT FRI AUG 29 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 150 PM MDT FRI AUG 29 2014 A WELL-DEFINED SHORTWAVE CONTINUES TO SLIDE EASTWARD ACROSS THE CWA THIS AFTN ALONG THE NORTHERN FRINGE OF BROAD UPPER-LEVEL RIDGING IN PLACE OVER THE CENTRAL ROCKIES. WATER VAPOR SATELLITE SHOWED THIS FEATURE OVER NORTHEAST WY AS OF 19Z MOVING QUICKLY TOWARD SOUTHWEST SD AND THE NORTHERN PANHANDLE. CONVECTIVE CHANCES ARE THE MAIN ISSUE IN THE NEAR TERM. ASIDE FROM MOUNTAIN CONVECTION...SHOWER AND TSTM CHANCES WILL BE ASSOCIATED WITH LARGER SCALE FORCING IN ADVANCE OF THE AFOREMENTIONED WAVE. THE NAM IS STILL THE MOST BULLISH WITH QPF OVER OUR NORTHEAST ZONES WHILE THE HRRR COMPOSITE REFLECTIVITY SHOWS FAIRLY MODEST CONVECTIVE COVERAGE. CONFIDENCE IS FAIRLY LOW IN JUST HOW WIDESPREAD THINGS WILL BE TODAY GIVEN WEAK SUBSIDENCE BENEATH THE RIDGE...AND RECENT RADAR ECHOS HAVE NOT BEEN ANYTHING TO WRITE HOME ABOUT. BELIEVE WE WILL SEE SOME MID AFTN TSTM ACTIVITY THOUGH OVER THE HIGH PLAINS. CURRENT SPEED OF THE TROUGH AXIS SUGGESTS THE BEST FORCING FOR ASCENT AND MOISTURE WILL SHIFT EAST OF THE CWA BY ABOUT 22Z...AFTER WHICH TIME TSTMS SHOULD DIMINISH. DESPITE GOOD SFC HEATING TODAY...LATEST SPC MESOSCALE ANALYSIS INDICATES LESS THAN 1000 J/KG OF SBCAPE. LLVL FLOW OUT OF THE NORTH OR NORTHWEST IS NOT CONTRIBUTING TO ANY REASONABLE SHEAR PROFILES EITHER SO ANY STRONGER STORMS SHOULD NOT BE WIDESPREAD THOUGH THEY ARE POSSIBLE. IT SHOULD BE A QUIET OVERNIGHT WITH AS SUBSIDENCE INCREASES OVER THE CWA. DO NOT EXPECT FOG DEVELOPMENT TONIGHT WITH UNFAVORABLE LLVL WINDS...BUT CANNOT RULE IT OUT IN THE PLATTE RIVER VALLEY IF WINDS ARE MORE SOUTHEAST THAN CURRENTLY PROGGED. SAT STILL LOOKS TO BE THE WARMEST DAY OF THE PERIOD WITH A VIGOROUS UPPER-LEVEL TROUGH LURKING OVER THE PACIFIC NW. THERMAL RIDGE AXIS BUILDS INTO THE CWA WITH NAM H7 TEMPS INCREASING TO 13-14 C FROM THE LARAMIE RANGE EASTWARD. MOST MOS GUIDANCE SUGGESTS HIGHS IN THE 83 TO 93 DEGREE RANGE OVER THE PLAINS...AND THIS LOOKS REASONABLE GIVEN THE SYNOPTIC SETUP. THE PROGRESSION OF THE TROUGH AND ASSOCIATED SFC COLD FRONT APPEARS A BIT SLOWER THAN EARLIER MODELS SUGGESTED...SO THIS SHOULD DELAY PCPN CHANCES UNTIL MID TO LATE AFTN ON SAT. MIDLVL QG FIELDS SHOW GOOD ASCENT SPREADING FROM WEST TO EAST AFTER 21Z ON SAT. THIS OCCURS ALONG WITH LLVL CONVERGENCE ASSOCIATED WITH A STRONG SFC COLD FRONT MOVING ACROSS THE CWA...SO AM CONFIDENT IN AT LEAST SCATTERED COVERAGE OF SHOWERS AND TSTMS. INSTABILITY COULD BE WANING BY THE TIME CONVECTION MOVES FAR ENOUGH EAST...BUT CAN NOT RULE OUT A STRONG OR LOCALLY SEVERE STORM WITH NAM CAPES AROUND 1500 J/KG BENEATH STEEP MIDLVL LAPSE RATES AND ABOUT 30 KTS OF H5 FLOW. IT WILL BE BREEZY ON SAT AFTN AND EARLY EVE...ESPECIALLY ALONG AND WEST OF THE LARAMIE RANGE AS HEIGHT GRADIENTS INCREASE ALOFT AND A STRONG SFC LOW MOVES ACROSS NORTHERN WY. WSW H7 WINDS AROUND 35 TO 40 KTS SUGGEST STRONGER WINDS OVER THE WIND PRONE AREAS...SO BUMPED UP GUSTS TO AROUND 45 MPH AT ARL AND BRX. SHOWERS WILL INCREASE OVERNIGHT THROUGH SUN AM...AND COULD CONTINUE THROUGH MUCH OF THE AFTN WITH COLDER AIR ALOFT AS THE TROUGH MOVES OVERHEAD. THE MODELS SHOW H7 TEMPS PLUNGING INTO THE MID SINGLE DIGITS C ON SUN IN THE POST-FROPA AIR MASS. LOOKING FOR HIGHS TO BE SOME 10 TO 15 DEGREES COOLER THAN SAT. FLOW ALOFT BRIEFLY BECOMES MORE ZONAL BY LATE SUN NIGHT...WITH THE ECMWF FINALLY STARTING TO BACK OFF ON QPF BY ABOUT 06Z MON. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 150 PM MDT FRI AUG 29 2014 SHORTWAVE TROUGH DRIVEN BY A 100+KT JET STREAK WILL SWEEP ACROSS THE CWFA ON MONDAY. A QUICK SHOT OF MOISTURE ALONG WITH A WEAK COLD FRONT WILL PRODUCE PERHAPS SOME AM SHOWER ACTIVITY ACROSS CARBON AND CONVERSE COUNTIES. BETTER CONVECTIVE CHANCES WILL AWAIT MONDAY AFTERNOON AS WEAK INSTABILITY IS REALIZED. PROGD SBCAPES OF AROUND 500 J/KG SUGGEST THAT MOST OF THE CONVECTION WILL BE OF THE WEAK VARIETY. HOWEVER WITH A STRONG JET OVERHEAD RESULTING IN AROUND 50 KNOTS OF DEEP LAYER SHEAR...CANT ENTIRELY RULE OUT A FEW STORMS BECOMING STRONG...ESPECIALLY OVR THE WRN NEBRASKA PANHANDLE LATE IN THE AFTERNOON. CONVECTIVE CHANCES WILL COME TO AN END QUICKLY MONDAY EVENING. A DRY ZONAL PATTERN WILL ENSUE ACROSS THE INTERMOUNTAIN WEST BEHIND MONDAYS DEPARTING SHORTWAVE TROF. THIS WILL BRING A DRY AND UNSEASONABLY WARM PERIOD INTO THE REGION. H7 TEMPERATURE PROGS INCREASE TO 14-16C...WHICH WILL YIELD DAILY HIGH TEMPERATURES THAT WILL REACH THE 80S AND LOW 90S EAST OF THE LARAMIE RANGE...WITH 70S OVR CARBON/ALBANY COUNTIES. THESE ABOVE AVERAGE TEMPERATURES WILL COMBINE WITH BREEZY CONDITIONS AND AN ALREADY DRY AIR MASS TO HEIGHTEN FIRE WEATHER CONCERNS WEDNESDAY AND THURSDAY. LATEST MODEL GUIDANCE CONTINUES TO POINT TO EITHER DEVELOPING ACROSS ACROSS THE PACNW OR PERHAPS A CUT-OFF JUST OFF THE CALIFORNIA COAST LATE IN THE WEEK. IN EITHER CASE...SOUTHWEST FLOW INTO THE ROCKYS WILL PROVIDE A FAVORABLE TRAJECTORY FOR MOISTURE TO RETURN TO THE CWFA AS EARLY AS THURSDAY NIGHT...BUT MORE SO FOR FRIDAY. TEMPERATURES WILL ALSO BE A TAD COOLER FRIDAY AS A THICKER CLOUD CANOPY PREVENTS FULL INSOLATION. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON) ISSUED AT 435 PM MDT FRI AUG 29 2014 CONVECTION REALLY DECREASING LATE THIS AFTERNOON AS THE UPPER SHORTWAVE MOVES OFF TO THE SOUTHEAST. ONLY AIRPORT THAT MAY SEE SOMETHING LATE TODAY WOULD BE KLAR. CONEVECTION RETURNS SATURDAY AFTERNOON WITH MOST AIRPORTS SEEING SOME THUNDER BY MID TO LATE AFTERNOON. && .FIRE WEATHER... ISSUED AT 150 PM MDT FRI AUG 29 2014 NO CONCERNS FOR CRITICAL FIRE WEATHER IN THE NEAR FUTURE. A STRONG WEATHER DISTURBANCE AND ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE AREA ON SAT AFTN THROUGH SUN MORNING. SHOWERS AND TSTMS WILL DEVELOP FROM WEST TO EAST ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE DURING THAT TIME. GUSTY WEST-TO-SOUTHWEST WINDS WILL OCCUR ALONG AND WEST OF THE LARAMIE RANGE ON SAT WITH GUSTS OF 35 TO 45 MPH...BUT MINIMUM RH VALUES SHOULD REMAIN ABOVE 20 PERCENT. COOLER ON SUN WITH CONTINUED BREEZY CONDITIONS AND ISOLATED TO SCATTERED SHOWERS AND WEAK TSTMS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...HAMMER LONG TERM...HAHN AVIATION...CLAYCOMB FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
200 PM MDT FRI AUG 29 2014 .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 150 PM MDT FRI AUG 29 2014 A WELL-DEFINED SHORTWAVE CONTINUES TO SLIDE EASTWARD ACROSS THE CWA THIS AFTN ALONG THE NORTHERN FRINGE OF BROAD UPPER-LEVEL RIDGING IN PLACE OVER THE CENTRAL ROCKIES. WATER VAPOR SATELLITE SHOWED THIS FEATURE OVER NORTHEAST WY AS OF 19Z MOVING QUICKLY TOWARD SOUTHWEST SD AND THE NORTHERN PANHANDLE. CONVECTIVE CHANCES ARE THE MAIN ISSUE IN THE NEAR TERM. ASIDE FROM MOUNTAIN CONVECTION...SHOWER AND TSTM CHANCES WILL BE ASSOCIATED WITH LARGER SCALE FORCING IN ADVANCE OF THE AFOREMENTIONED WAVE. THE NAM IS STILL THE MOST BULLISH WITH QPF OVER OUR NORTHEAST ZONES WHILE THE HRRR COMPOSITE REFLECTIVITY SHOWS FAIRLY MODEST CONVECTIVE COVERAGE. CONFIDENCE IS FAIRLY LOW IN JUST HOW WIDESPREAD THINGS WILL BE TODAY GIVEN WEAK SUBSIDENCE BENEATH THE RIDGE...AND RECENT RADAR ECHOS HAVE NOT BEEN ANYTHING TO WRITE HOME ABOUT. BELIEVE WE WILL SEE SOME MID AFTN TSTM ACTIVITY THOUGH OVER THE HIGH PLAINS. CURRENT SPEED OF THE TROUGH AXIS SUGGESTS THE BEST FORCING FOR ASCENT AND MOISTURE WILL SHIFT EAST OF THE CWA BY ABOUT 22Z...AFTER WHICH TIME TSTMS SHOULD DIMINISH. DESPITE GOOD SFC HEATING TODAY...LATEST SPC MESOSCALE ANALYSIS INDICATES LESS THAN 1000 J/KG OF SBCAPE. LLVL FLOW OUT OF THE NORTH OR NORTHWEST IS NOT CONTRIBUTING TO ANY REASONABLE SHEAR PROFILES EITHER SO ANY STRONGER STORMS SHOULD NOT BE WIDESPREAD THOUGH THEY ARE POSSIBLE. IT SHOULD BE A QUIET OVERNIGHT WITH AS SUBSIDENCE INCREASES OVER THE CWA. DO NOT EXPECT FOG DEVELOPMENT TONIGHT WITH UNFAVORABLE LLVL WINDS...BUT CANNOT RULE IT OUT IN THE PLATTE RIVER VALLEY IF WINDS ARE MORE SOUTHEAST THAN CURRENTLY PROGGED. SAT STILL LOOKS TO BE THE WARMEST DAY OF THE PERIOD WITH A VIGOROUS UPPER-LEVEL TROUGH LURKING OVER THE PACIFIC NW. THERMAL RIDGE AXIS BUILDS INTO THE CWA WITH NAM H7 TEMPS INCREASING TO 13-14 C FROM THE LARAMIE RANGE EASTWARD. MOST MOS GUIDANCE SUGGESTS HIGHS IN THE 83 TO 93 DEGREE RANGE OVER THE PLAINS...AND THIS LOOKS REASONABLE GIVEN THE SYNOPTIC SETUP. THE PROGRESSION OF THE TROUGH AND ASSOCIATED SFC COLD FRONT APPEARS A BIT SLOWER THAN EARLIER MODELS SUGGESTED...SO THIS SHOULD DELAY PCPN CHANCES UNTIL MID TO LATE AFTN ON SAT. MIDLVL QG FIELDS SHOW GOOD ASCENT SPREADING FROM WEST TO EAST AFTER 21Z ON SAT. THIS OCCURS ALONG WITH LLVL CONVERGENCE ASSOCIATED WITH A STRONG SFC COLD FRONT MOVING ACROSS THE CWA...SO AM CONFIDENT IN AT LEAST SCATTERED COVERAGE OF SHOWERS AND TSTMS. INSTABILITY COULD BE WANING BY THE TIME CONVECTION MOVES FAR ENOUGH EAST...BUT CAN NOT RULE OUT A STRONG OR LOCALLY SEVERE STORM WITH NAM CAPES AROUND 1500 J/KG BENEATH STEEP MIDLVL LAPSE RATES AND ABOUT 30 KTS OF H5 FLOW. IT WILL BE BREEZY ON SAT AFTN AND EARLY EVE...ESPECIALLY ALONG AND WEST OF THE LARAMIE RANGE AS HEIGHT GRADIENTS INCREASE ALOFT AND A STRONG SFC LOW MOVES ACROSS NORTHERN WY. WSW H7 WINDS AROUND 35 TO 40 KTS SUGGEST STRONGER WINDS OVER THE WIND PRONE AREAS...SO BUMPED UP GUSTS TO AROUND 45 MPH AT ARL AND BRX. SHOWERS WILL INCREASE OVERNIGHT THROUGH SUN AM...AND COULD CONTINUE THROUGH MUCH OF THE AFTN WITH COLDER AIR ALOFT AS THE TROUGH MOVES OVERHEAD. THE MODELS SHOW H7 TEMPS PLUNGING INTO THE MID SINGLE DIGITS C ON SUN IN THE POST-FROPA AIR MASS. LOOKING FOR HIGHS TO BE SOME 10 TO 15 DEGREES COOLER THAN SAT. FLOW ALOFT BRIEFLY BECOMES MORE ZONAL BY LATE SUN NIGHT...WITH THE ECMWF FINALLY STARTING TO BACK OFF ON QPF BY ABOUT 06Z MON. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 150 PM MDT FRI AUG 29 2014 SHORTWAVE TROUGH DRIVEN BY A 100+KT JET STREAK WILL SWEEP ACROSS THE CWFA ON MONDAY. A QUICK SHOT OF MOISTURE ALONG WITH A WEAK COLD FRONT WILL PRODUCE PERHAPS SOME AM SHOWER ACTIVITY ACROSS CARBON AND CONVERSE COUNTIES. BETTER CONVECTIVE CHANCES WILL AWAIT MONDAY AFTERNOON AS WEAK INSTABILITY IS REALIZED. PROGD SBCAPES OF AROUND 500 J/KG SUGGEST THAT MOST OF THE CONVECTION WILL BE OF THE WEAK VARIETY. HOWEVER WITH A STRONG JET OVERHEAD RESULTING IN AROUND 50 KNOTS OF DEEP LAYER SHEAR...CANT ENTIRELY RULE OUT A FEW STORMS BECOMING STRONG...ESPECIALLY OVR THE WRN NEBRASKA PANHANDLE LATE IN THE AFTERNOON. CONVECTIVE CHANCES WILL COME TO AN END QUICKLY MONDAY EVENING. A DRY ZONAL PATTERN WILL ENSUE ACROSS THE INTERMOUNTAIN WEST BEHIND MONDAYS DEPARTING SHORTWAVE TROF. THIS WILL BRING A DRY AND UNSEASONABLY WARM PERIOD INTO THE REGION. H7 TEMPERATURE PROGS INCREASE TO 14-16C...WHICH WILL YIELD DAILY HIGH TEMPERATURES THAT WILL REACH THE 80S AND LOW 90S EAST OF THE LARAMIE RANGE...WITH 70S OVR CARBON/ALBANY COUNTIES. THESE ABOVE AVERAGE TEMPERATURES WILL COMBINE WITH BREEZY CONDITIONS AND AN ALREADY DRY AIR MASS TO HEIGHTEN FIRE WEATHER CONCERNS WEDNESDAY AND THURSDAY. LATEST MODEL GUIDANCE CONTINUES TO POINT TO EITHER DEVELOPING ACROSS ACROSS THE PACNW OR PERHAPS A CUT-OFF JUST OFF THE CALIFORNIA COAST LATE IN THE WEEK. IN EITHER CASE...SOUTHWEST FLOW INTO THE ROCKYS WILL PROVIDE A FAVORABLE TRAJECTORY FOR MOISTURE TO RETURN TO THE CWFA AS EARLY AS THURSDAY NIGHT...BUT MORE SO FOR FRIDAY. TEMPERATURES WILL ALSO BE A TAD COOLER FRIDAY AS A THICKER CLOUD CANOPY PREVENTS FULL INSOLATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING) ISSUED AT 1200 PM MDT FRI AUG 29 2014 CONVECTIVE TIMING AND STRENGTH AGAIN THE MAIN FOCUS FOR THIS SET OF TAFS. RADAR SHOWS LINE OF CONVECTIVE DEVELOPMENT EXTENDING FROM AROUND KCDR SW TO NR KLAR AS OF NOON. THIS WILL BE THE AREA TO WATCH THIS AFTERNOON AS THIS DISTURBANCE AND BOUNDARY SHIFTS SOUTHEAST ACROSS THE AREA. FOR NOW HAVE KEPT AND ADDED VCTS TO ALL LOCATIONS THIS AFTERNOON WITH THE EXCEPTION OF KRWL...WHICH ARE ALREADY WEST OF THE DISTURBANCE. ANY SHOWERS OR THUNDERSTORMS THAT DO DEVELOP SHOULD SLIDE EAST OF THE AREA BY BETWEEN 22-24Z... LEAVING VFR CONDITIONS AS SKIES CLEAR. && .FIRE WEATHER... ISSUED AT 150 PM MDT FRI AUG 29 2014 NO CONCERNS FOR CRITICAL FIRE WEATHER IN THE NEAR FUTURE. A STRONG WEATHER DISTURBANCE AND ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE AREA ON SAT AFTN THROUGH SUN MORNING. SHOWERS AND TSTMS WILL DEVELOP FROM WEST TO EAST ACROSS SOUTHEAST WY AND THE WESTERN NE PANHANDLE DURING THAT TIME. GUSTY WEST-TO-SOUTHWEST WINDS WILL OCCUR ALONG AND WEST OF THE LARAMIE RANGE ON SAT WITH GUSTS OF 35 TO 45 MPH...BUT MINIMUM RH VALUES SHOULD REMAIN ABOVE 20 PERCENT. COOLER ON SUN WITH CONTINUED BREEZY CONDITIONS AND ISOLATED TO SCATTERED SHOWERS AND WEAK TSTMS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...HAMMER LONG TERM...HAHN AVIATION...HAHN FIRE WEATHER...HAMMER