Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/28/15


AREA FORECAST DISCUSSION
NWS PUEBLO CO
1127 PM MDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 301 PM MDT TUE AUG 25 2015 AN UPR RIDGE REMAINS OVR THE AREA TODAY AND SO FAR THIS AFTERNOON...SHOWERS AND TSTMS HAVE BEEN CONFINED TO PORTIONS OF THE I-25 CORRIDOR...PALMER DVD AND WESTWARD. THE HRRR SHOWS THE POTENTIAL FOR SOME ISOLD SHOWERS/TSTMS TO ALSO DEVELOP OR MOVE OVER THE SERN PLAINS LATER THIS AFTERNOON AND THIS EVENING. MOST OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT...HOWEVER THE HRRR AND NAM SHOW THE POTENTIAL FOR SOME LINGERING ACTIVITY OVR THE SW MTNS THRU THE NIGHT. THE GFS ALSO SHOW SOME LINGERING ACTIVITY AFTER MIDNIGHT OVR THE ERN MTNS. ON WED THE UPR RIDGE REMAINS OVR THE AREA BUT A DISTURBANCE WL MOVE NORTH-NORTHEASTWARD FROM SWRN CO TO NORTH CENTRAL CO DURING THE DAY. THIS IS EXPECTED TO BRING AN INCREASE IN SHOWERS/TSTMS ACTIVITY TO THE CONTDVD. THE MAIN THREAT ALONG THE CONTDVD WL BE HEAVY RAIN...ESPECIALLY OVR THE BURN SCARS. OVR THE SERN PLAINS...DEW POINTS ARE EXPECTED TO ONLY BE IN THE UPPER 30S TO LOWER 40S WED AFTERNOON...AND CONDITIONS SHOULD GENERALLY BE DRY AND HOT AGAIN. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 301 PM MDT TUE AUG 25 2015 ...BEST CHANCE OF RAIN FROM WEDNESDAY NIGHT INTO THURSDAY... ...REST OF THE PERIOD MAINLY HOT AND DRY FOR THE LOWLANDS... ONLY REAL CONCERN IN THE EXTENDED IS WED EVENING...WHEN ONGOING STORMS OVER THE MTS COULD LEAD TO SOME LOCALIZED FLOODING CONCERNS...ESPECIALLY FOR THE BURN SCARS AND AREAS OF STEEP TERRAIN. COULD SEE SOME CONVECTION LINGER THROUGH THE NIGHT INTO THU MORNING. ONE MINOR TREND IN MODEL GUIDANCE IS THAT THERE SHOULD BE A SECONDARY UPPER DISTURBANCE THAT COMES THROUGH THURSDAY AFTERNOON OVER THE PLAINS...AND THIS MIGHT BRING A SLIGHTLY BETTER CHANCE FOR SOME AFTERNOON AND EVENING STORMS FOR THE PLAINS DURING THAT TIME. THE UPPER TROUGH DOES NOT REALLY CLEAR THE CWA UNTIL EARLY FRIDAY. SO WHILE IT STILL LOOKS TO BE FAIRY WARM THU...THERE SHOULD BE A LITTLE BETTER CHANCE OF STORMS...AND AFTER A COLD FRONT MOVES THROUGH THU EVENING IT WILL BE A FEW DEGREES COOLER ON FRI...OR RIGHT AROUND SEASONAL NORMS. REST OF THE EXTENDED FORECAST LOOKS PRETTY UNEVENTFUL. A PERSISTENT RIDGE WILL BE OVER THE DESERT SW...AND THIS WILL KEEP MOST OF THE CWA IN ABOVE AVERAGE TEMPERATURES AND WITH NO WIDESPREAD PRECIP. MOS GUIDANCE FOR THE EXTENDED AT KPUB FOR EXAMPLE IS WITHIN A COUPLE DEGREES FOR THE HIGH TEMPS THROUGH EARLY NEXT WEEK. SHOULD SEE LOWER 90S DOMINATE THE TEMPS FOR THE PLAINS DURING THIS TIME. THE MONSOON WILL BE PRESENT BUT DOES NOT LOOK TERRIBLY ACTIVE. WILL SEE DAILY CHANCES OF AFTERNOON-EVENING STORMS OVER THE MTN AREAS DURING THIS PERIOD. STILL A BIT UNCERTAIN HOW A PACNW TROUGH WILL EVOLVE OVER THE WEEKEND AND INTO NEXT WEEK...BUT MODEL CONSENSUS IS THAT IT WILL LIFT OFF TO THE E-NE OVER THE NRN ROCKIES AND CANADIAN PLAINS...SO THE IMPACT FOR OUR AREA LOOKS MINIMAL. ROSE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1122 PM MDT TUE AUG 25 2015 UPPER WAVE OVER AZ THIS EVENING WILL ROTATE NORTHWARD ACROSS COLORADO LATE TONIGHT AND THROUGH THE DAY ON WED. EXPECT ISOLATED TSRA OVER THE SOUTHWEST MOUNTAINS OVERNIGHT...WITH SCT TO NMRS STORMS OVER MOST MOUNTAINS AND INTERIOR VALLEYS DURING THE DAY WED. MANY MT PASSES AND HIGHER PEAKS WILL BE OBSCURED FOR MUCH OF THE DAY WED. AT THE TAF SITES...BEST CHANCE FOR TSRA WILL BE AT KALS...AND WILL KEEP A VCTS MENTION IN PLACE FOR MUCH OF THE AFTERNOON/EARLY EVENING. FARTHER EAST AT KPUB AND KCOS...CAN`T RULE OUT A LATE DAY TSRA AT EITHER SITE...THOUGH CHANCES LOOK TOO LOW TO INCLUDE IN THE TAF AT THIS POINT. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...28 LONG TERM...ROSE AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS ALBANY NY
428 PM EDT WED AUG 26 2015 .SYNOPSIS... AN UPPER LEVEL LOW OVER SOUTHEASTERN CANADA AND THE NORTHEAST WILL BRING ISOLATED TO SCATTERED SHOWERS MAINLY NORTHWEST OF THE CAPITAL REGION TONIGHT INTO TOMORROW. HIGH PRESSURE WILL RIDGE IN OVER PENNSYLVANIA AND NEW YORK WITH CLEARING SKIES AND COOL CONDITIONS THURSDAY NIGHT. THIS SURFACE HIGH WILL YIELD FAIR AND DRY CONDITIONS FRIDAY INTO FIRST HALF OF THE WEEKEND WITH TEMPERATURES RETURNING TO ABOVE NORMAL READINGS FOR LATE AUGUST. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 418 PM EDT...AN UPPER LEVEL LOW CONTINUES TO BE CENTERED JUST S/SE OF JAMES BAY OVER SW QUEBEC. WEAK SHORT-WAVE IMPULSES ROTATING AROUND BASE OF THE TROUGH CONTINUE TO FOCUS SOME LAKE ENHANCED ISOLD-WDLY SCT RAIN SHOWERS OVER THE WRN DACKS AND CLOSE TO THE WRN MOHAWK VALLEY. OTHER ISOLD-SCT SHOWERS OR SPRINKLES CONTINUE OVER WRN NY...NRN PA...AND SE ONTARIO DUE TO THE VORTICITY ADVECTION WITH THE NEXT SHORT-WAVE EMBEDDED IN THE LONG- WAVE TROUGH. THE WATER VAPOR LOOP THIS AFTERNOON SHOWS THE NEXT SPOKE OF ENERGY MOVING ACROSS LAKE HURON AND GEORGIAN BAY. THE CYCLONIC VORTICITY ADVECTION AND FETCH OF MOISTURE OFF LAKES ERIE AND ONTARIO SHOULD KEEP ISOLD-SCT SHOWERS OVER THE WRN-SRN DACKS...THE W-CNTRL MOHAWK VALLEY AND THE NRN CATSKILLS OVERNIGHT. THE HIGHER CHC POPS WERE KEPT IN OVER THE WRN DACKS. THE NAM AND HRRR BOTH INDICATED A FAVORABLE LAKE TRAJECTORY OFF LAKE ONTARIO TONIGHT FOR A BAND OF LAKE EFFECT/ENHANCED SHOWERS AHEAD OF THE SHORT-WAVE AND UPPER LEVEL TROUGH AXIS. H850 TEMPS WILL LOWER TO +6C TO +8C AT H850 OVER THE WARM LAKE TEMPS OF +15C +20C ON THE ERN HALF OF LAKE ONTARIO. SOME LAKE EFFECT CLOUDS WILL STREAM DOWNSTREAM...ESPECIALLY NORTH AND WEST OF THE CAPITAL DISTRICT. ANY SHOWERS SHOULD BE LIGHT IN INTENSITY. THE UPPER TROUGH AXIS BASED ON THE NAM/GFS/ECMWF WILL BE APPROACHING THE HUDSON RIVER VALLEY BY DAY BREAK. LOWS TONIGHT WILL RANGE FROM THE U40S TO L50S OVER THE MTNS...AND GENERALLY LOWER TO MID 50S IN THE VALLEYS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... TOMORROW...THE UPPER TROUGH AXIS SHOULD CLEAR MOST IF NOT ALL THE FORECAST AREA BY NOONTIME. A FEW ISOLD-SCT INSTABILITY SHOWERS WITH THE RESIDUAL COLD POOL IN THE CYCLONIC FLOW MAY PERSIST NORTHWEST OF THE CAPITAL REGION INTO THE EARLY PM. SUNSHINE WILL MIX WITH CLOUDS...AND IT WILL BE BREEZY AND COOL WITH H850 TEMPS OF +7C TO +11C FROM NW TO SE ACROSS THE FCST AREA. HIGH TEMPS WILL RUN SLIGHTLY BELOW NORMAL WITH LOWER TO M70S IN THE VALLEY AREAS...EXCEPT OVER THE MID HUDSON VALLEY...AND SRN LITCHFIELD CTY WHERE SOME U70S ARE POSSIBLE. EXPECT M60S TO L70S OVER THE HILLS AND MTNS. THU NIGHT...HIGH PRESSURE BUILDS IN OVER PA AND NY WITH CLEARING SKIES AND LIGHT TO CALM WINDS. SOME PATCHY VALLEY RADIATIONAL FOG FORMATION IS POSSIBLE...ESPECIALLY BETWEEN 06Z-12Z. IT SHOULD BE A GOOD RADIATIONAL COOLING NIGHT WITH THE DIMINISHING WINDS. LOWS WILL BE IN THE M40S TO AROUND 50F NORTH OF THE CAPITAL DISTRICT...AND GENERALLY 50-55F TO THE SOUTH...EXCEPT SOME U40S OVER THE BERKSHIRES...AND ERN CATSKILLS. FRIDAY INTO SATURDAY...A NICE STRETCH OF LATE AUGUST WX IS EXPECTED WITH MODERATING TEMPS INTO THE WEEKEND. INITIALLY...THE MID LEVEL FLOW WILL BE ZONAL ON FRIDAY...WITH THE SFC HIGH OVER THE NORTHEAST. MOSTLY SUNNY SKIES AND PLEASANT HUMIDITY LEVELS CONTINUE. TEMPS WILL BE NEAR NORMAL FOR ERN NY AND WRN NEW ENGLAND. FRI NIGHT...THE SFC HIGH RIDGES IN FROM OFF THE SRN NEW ENGLAND COAST. LOW AND MID LEVEL HEIGHTS START TO INCREASE. ANOTHER COOL NIGHT IS EXPECTED WITH LOWS MAINLY IN THE 50S WITH SOME U40S OVER THE HIGHER TERRAIN. WARM ADVECTION CONTINUES ON SATURDAY WITH H850 TEMPS OF +14C TO +16C WITH S/SW FLOW IN THE BOUNDARY LAYER ON THE RIM OF THE OFFSHORE MID AND UPPER RIDGE. MAX TEMPS SHOULD RISE AT LEAST 5 DEGREES OR SO ABOVE NORMAL. HUMIDITY LEVELS SLIGHTLY INCREASE WITH DEWPTS IN THE M5OS L60S. A WEAKENING UPPER LEVEL DISTURBANCE WILL BE APPROACHING FROM THE WEST WITH AN INCREASE OF SOME CLOUDS LATE IN THE DAY. OVERALL...A NICE START TO THE LAST WEEKEND IN AUGUST. HIGHS WILL BE IN THE MID TO U70S OVER THE HIGHER TERRAIN...AND GENERALLY 80-85F IN THE VALLEYS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... TO START THE LONG TERM PERIOD SATURDAY NIGHT INTO SUNDAY MORNING...HIGH PRESSURE WILL BE ANCHORED OVER THE REGION PROVIDING FAIR WEATHER CONDITIONS. A ISOLATED CHANCE OF A SHOWER OR THUNDERSTORM IS POSSIBLE AS WE GO INTO SUNDAY AFTERNOON AS THE LATEST 26/12Z MODEL AND NUMERICAL DATA SHOW A LOW AMPLITUDE UPPER LEVEL SHORTWAVE MOVING EAST OUT OF CANADA ACROSS PORTIONS OF OUR FAR NORTHERN AREAS. COUPLED WITH DIURNAL HEATING TRENDS AND SOUTHWESTERLY FLOW ADVECTING MOISTURE INTO THE REGION...SOME PRECIPITATION SUNDAY AFTERNOON IS POSSIBLE. AS WE GO INTO THE WORK WEEK...OVERALL IT WILL FEATURE DRY CONDITIONS AS THE UPPER LEVEL RIDGE OF HIGH PRESSURE OUT OVER THE MISSISSIPPI RIVER VALLEY WILL MOVE EASTWARD OVER THE REGION. AS IT SLOWLY MAKES IT WAY EAST...MOISTURE FROM THE GULF OF MEXICO RIDING OVER THE DEVELOPING UPPER LEVEL RIDGE MAY BRING AN ISOLATED SHOWER TO OUR FAR SOUTHERN AREAS ON WEDNESDAY BUT THAT IS TOO FAR OUT TO SAY WITH CONFIDENCE AT THIS TIME. HIGH TEMPERATURES THROUGHOUT THE EXTENDED PERIOD WILL BE WELL ABOVE AVERAGE WITH HIGH TEMPS RANGING FROM THE UPPER 70S IN THE HIGH TERRAIN TO MID AND EVEN SOME UPPER 80S AS WE GO THROUGH THE MIDDLE OF NEXT WEEK. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS ARE CURRENTLY IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN STRATOCU AROUND 4-6 KFT. THE COMBINATION OF DAYTIME HEATING AND AN UPPER LEVEL DISTURBANCE PASSING BY TO THE NORTH WILL KEEP THESE CLOUDS AROUND THROUGH THE EARLY EVENING HOURS...BUT FLYING CONDITIONS WILL CONTINUE TO BE VFR WITH W-NW SFC WINDS AT 5-10 KTS. ANY RAIN SHOWERS WILL REMAIN NORTH AND WEST OF THE TAF SITES OVER THE ADIRONDACKS. WINDS WILL START TO DECREASE THIS EVENING...BUT WILL PROBABLY CONTINUE AT LIGHT SPEEDS THROUGH THE OVERNIGHT HOURS. WHILE THERE MAY BE A DECREASE IN CLOUDS FOR THE FIRST PART OF TONIGHT...THE UPPER LEVEL TROUGH AXIS WILL BE PASSING THROUGH THE REGION FOR THE LATE NIGHT HOURS. BECAUSE OF THIS...WILL CONTINUE GO WITH AT LEAST SCT CLOUDS THROUGH THE OVERNIGHT HOURS. THE COMBINATION OF THESE PASSING CLOUDS...A LINGERING LIGHT BREEZE...AND A DRY BOUNDARY LAYER SHOULD PREVENT MUCH RADIATIONAL FOG FROM DEVELOPING TONIGHT. IF WINDS WERE TO DECOUPLE AND CLOUDS WERE LESS THAN EXPECTED...SOME PATCHES OF FOG COULD BE POSSIBLE...BUT CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INCLUDE IN THE TAF AT THIS TIME. DURING THE DAY ON THURSDAY...SCT-BKN CLOUDS WILL BE IN PLACE AT 4-5 KFT WILL CONTINUED VFR CONDITIONS. W-SW WINDS WILL BE AROUND 5-10 KTS. OUTLOOK... THURSDAY NIGHT: NO OPERATIONAL IMPACT. PATCHY FG. FRIDAY TO SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA. SUNDAY NIGHT TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A BROAD UPPER LEVEL LOW OVER SOUTHEASTERN CANADA AND THE NORTHEAST WILL BRING ISOLATED TO SCATTERED SHOWERS MAINLY NORTHWEST OF THE CAPITAL REGION TONIGHT INTO TOMORROW. HIGH PRESSURE WILL BUILD IN OVER NEW YORK AND NEW ENGLAND WITH CLEARING SKIES AND COOL CONDITIONS THURSDAY NIGHT. THIS SURFACE HIGH WILL YIELD FAIR AND DRY CONDITIONS FRIDAY INTO FIRST HALF OF THE WEEKEND WITH TEMPERATURES RETURNING TO ABOVE NORMAL READINGS FOR LATE AUGUST. THE RH VALUES WILL RISE CLOSE TO 100 PERCENT TOMORROW MORNING WITH SOME DEW FORMATION. THEY WILL LOWER TO 45 TO 60 PERCENT THURSDAY AFTERNOON...AND THEN INCREASE TO 90 TO 100 PERCENT FRIDAY MORNING. THE WINDS WILL BE FROM THE WEST TO NORTHWEST AT LESS THAN 10 MPH TONIGHT...AND THEN WILL INCREASE FROM THE NORTHWEST AT 10 TO 15 MPH THURSDAY AFTERNOON...AND THEN WILL BECOME LIGHT TO CALM BY FRIDAY MORNING. && .HYDROLOGY... NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS ENDING MONDAY. AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE REGION TONIGHT INTO TOMORROW BRINGING LIGHT ISOLATED TO SCATTERED SHOWERS PRIMARILY ACROSS THE SOUTHERN ADIRONDACKS. BASIN-AVERAGE RAINFALL VALUES ARE EXPECTED TO BE UNDER A QUARTER OF AN INCH. HIGH PRESSURE WILL BUILD IN ACROSS THE REGION THURSDAY NIGHT AND INTO THE WEEKEND RESULTING IN PRIMARILY DRY WEATHER FOR MOST OF THE HYDRO SERVICE AREA. A WEAK DISTURBANCE MAY BRING AN ISOLATED SHOWER OR THUNDERSTORM LATE SUNDAY ESPECIALLY WEST OF THE HUDSON RIVER VALLEY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...LFM AVIATION...FRUGIS FIRE WEATHER...WASULA HYDROLOGY...SNYDER/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
418 PM EDT WED AUG 26 2015 .SYNOPSIS... AN UPPER LEVEL LOW OVER SOUTHEASTERN CANADA AND THE NORTHEAST WILL BRING ISOLATED TO SCATTERED SHOWERS MAINLY NORTHWEST OF THE CAPITAL REGION TONIGHT INTO TOMORROW. HIGH PRESSURE WILL RIDGE IN OVER PENNSYLVANIA AND NEW YORK WITH CLEARING SKIES AND COOL CONDITIONS THURSDAY NIGHT. THIS SURFACE HIGH WILL YIELD FAIR AND DRY CONDITIONS FRIDAY INTO FIRST HALF OF THE WEEKEND WITH TEMPERATURES RETURNING TO ABOVE NORMAL READINGS FOR LATE AUGUST. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 418 PM EDT...AN UPPER LEVEL LOW CONTINUES TO BE CENTERED JUST S/SE OF JAMES BAY OVER SW QUEBEC. WEAK SHORT-WAVE IMPULSES ROTATING AROUND BASE OF THE TROUGH CONTINUE TO FOCUS SOME LAKE ENHANCED ISOLD-WDLY SCT RAIN SHOWERS OVER THE WRN DACKS AND CLOSE TO THE WRN MOHAWK VALLEY. OTHER ISOLD-SCT SHOWERS OR SPRINKLES CONTINUE OVER WRN NY...NRN PA...AND SE ONTARIO DUE TO THE VORTICITY ADVECTION WITH THE NEXT SHORT-WAVE EMBEDDED IN THE LONG- WAVE TROUGH. THE WATER VAPOR LOOP THIS AFTERNOON SHOWS THE NEXT SPOKE OF ENERGY MOVING ACROSS LAKE HURON AND GEORGIAN BAY. THE CYCLONIC VORTICITY ADVECTION AND FETCH OF MOISTURE OFF LAKES ERIE AND ONTARIO SHOULD KEEP ISOLD-SCT SHOWERS OVER THE WRN-SRN DACKS...THE W-CNTRL MOHAWK VALLEY AND THE NRN CATSKILLS OVERNIGHT. THE HIGHER CHC POPS WERE KEPT IN OVER THE WRN DACKS. THE NAM AND HRRR BOTH INDICATED A FAVORABLE LAKE TRAJECTORY OFF LAKE ONTARIO TONIGHT FOR A BAND OF LAKE EFFECT/ENHANCED SHOWERS AHEAD OF THE SHORT-WAVE AND UPPER LEVEL TROUGH AXIS. H850 TEMPS WILL LOWER TO +6C TO +8C AT H850 OVER THE WARM LAKE TEMPS OF +15C +20C ON THE ERN HALF OF LAKE ONTARIO. SOME LAKE EFFECT CLOUDS WILL STREAM DOWNSTREAM...ESPECIALLY NORTH AND WEST OF THE CAPITAL DISTRICT. ANY SHOWERS SHOULD BE LIGHT IN INTENSITY. THE UPPER TROUGH AXIS BASED ON THE NAM/GFS/ECMWF WILL BE APPROACHING THE HUDSON RIVER VALLEY BY DAY BREAK. LOWS TONIGHT WILL RANGE FROM THE U40S TO L50S OVER THE MTNS...AND GENERALLY LOWER TO MID 50S IN THE VALLEYS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... TOMORROW...THE UPPER TROUGH AXIS SHOULD CLEAR MOST IF NOT ALL THE FORECAST AREA BY NOONTIME. A FEW ISOLD-SCT INSTABILITY SHOWERS WITH THE RESIDUAL COLD POOL IN THE CYCLONIC FLOW MAY PERSIST NORTHWEST OF THE CAPITAL REGION INTO THE EARLY PM. SUNSHINE WILL MIX WITH CLOUDS...AND IT WILL BE BREEZY AND COOL WITH H850 TEMPS OF +7C TO +11C FROM NW TO SE ACROSS THE FCST AREA. HIGH TEMPS WILL RUN SLIGHTLY BELOW NORMAL WITH LOWER TO M70S IN THE VALLEY AREAS...EXCEPT OVER THE MID HUDSON VALLEY...AND SRN LITCHFIELD CTY WHERE SOME U70S ARE POSSIBLE. EXPECT M60S TO L70S OVER THE HILLS AND MTNS. THU NIGHT...HIGH PRESSURE BUILDS IN OVER PA AND NY WITH CLEARING SKIES AND LIGHT TO CALM WINDS. SOME PATCHY VALLEY RADIATIONAL FOG FORMATION IS POSSIBLE...ESPECIALLY BETWEEN 06Z-12Z. IT SHOULD BE A GOOD RADIATIONAL COOLING NIGHT WITH THE DIMINISHING WINDS. LOWS WILL BE IN THE M40S TO AROUND 50F NORTH OF THE CAPITAL DISTRICT...AND GENERALLY 50-55F TO THE SOUTH...EXCEPT SOME U40S OVER THE BERKSHIRES...AND ERN CATSKILLS. FRIDAY INTO SATURDAY...A NICE STRETCH OF LATE AUGUST WX IS EXPECTED WITH MODERATING TEMPS INTO THE WEEKEND. INITIALLY...THE MID LEVEL FLOW WILL BE ZONAL ON FRIDAY...WITH THE SFC HIGH OVER THE NORTHEAST. MOSTLY SUNNY SKIES AND PLEASANT HUMIDITY LEVELS CONTINUE. TEMPS WILL BE NEAR NORMAL FOR ERN NY AND WRN NEW ENGLAND. FRI NIGHT...THE SFC HIGH RIDGES IN FROM OFF THE SRN NEW ENGLAND COAST. LOW AND MID LEVEL HEIGHTS START TO INCREASE. ANOTHER COOL NIGHT IS EXPECTED WITH LOWS MAINLY IN THE 50S WITH SOME U40S OVER THE HIGHER TERRAIN. WARM ADVECTION CONTINUES ON SATURDAY WITH H850 TEMPS OF +14C TO +16C WITH S/SW FLOW IN THE BOUNDARY LAYER ON THE RIM OF THE OFFSHORE MID AND UPPER RIDGE. MAX TEMPS SHOULD RISE AT LEAST 5 DEGREES OR SO ABOVE NORMAL. HUMIDITY LEVELS SLIGHTLY INCREASE WITH DEWPTS IN THE M5OS L60S. A WEAKENING UPPER LEVEL DISTURBANCE WILL BE APPROACHING FROM THE WEST WITH AN INCREASE OF SOME CLOUDS LATE IN THE DAY. OVERALL...A NICE START TO THE LAST WEEKEND IN AUGUST. HIGHS WILL BE IN THE MID TO U70S OVER THE HIGHER TERRAIN...AND GENERALLY 80-85F IN THE VALLEYS. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... TO START THE LONG TERM PERIOD SATURDAY NIGHT INTO SUNDAY MORNING...HIGH PRESSURE WILL BE ANCHORED OVER THE REGION PROVIDING FAIR WEATHER CONDITIONS. A ISOLATED CHANCE OF A SHOWER OR THUNDERSTORM IS POSSIBLE AS WE GO INTO SUNDAY AFTERNOON AS THE LATEST 26/12Z MODEL AND NUMERICAL DATA SHOW A LOW AMPLITUDE UPPER LEVEL SHORTWAVE MOVING EAST OUT OF CANADA ACROSS PORTIONS OF OUR FAR NORTHERN AREAS. COUPLED WITH DIURNAL HEATING TRENDS AND SOUTHWESTERLY FLOW ADVECTING MOISTURE INTO THE REGION...SOME PRECIPITATION SUNDAY AFTERNOON IS POSSIBLE. AS WE GO INTO THE WORK WEEK...OVERALL IT WILL FEATURE DRY CONDITIONS AS THE UPPER LEVEL RIDGE OF HIGH PRESSURE OUT OVER THE MISSISSIPPI RIVER VALLEY WILL MOVE EASTWARD OVER THE REGION. AS IT SLOWLY MAKES IT WAY EAST...MOISTURE FROM THE GULF OF MEXICO RIDING OVER THE DEVELOPING UPPER LEVEL RIDGE MAY BRING AN ISOLATED SHOWER TO OUR FAR SOUTHERN AREAS ON WEDNESDAY BUT THAT IS TOO FAR OUT TO SAY WITH CONFIDENCE AT THIS TIME. HIGH TEMPERATURES THROUGHOUT THE EXTENDED PERIOD WILL BE WELL ABOVE AVERAGE WITH HIGH TEMPS RANGING FROM THE UPPER 70S IN THE HIGH TERRAIN TO MID AND EVEN SOME UPPER 80S AS WE GO THROUGH THE MIDDLE OF NEXT WEEK. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... VFR CONDITIONS ARE CURRENTLY IN PLACE AT ALL TAF SITES WITH JUST SCT-BKN STRATOCU AROUND 4-6 KFT. THE COMBINATION OF DAYTIME HEATING AND AN UPPER LEVEL DISTURBANCE PASSING BY TO THE NORTH WILL KEEP THESE CLOUDS AROUND THROUGH THE EARLY EVENING HOURS...BUT FLYING CONDITIONS WILL CONTINUE TO BE VFR WITH W-NW SFC WINDS AT 5-10 KTS. ANY RAIN SHOWERS WILL REMAIN NORTH AND WEST OF THE TAF SITES OVER THE ADIRONDACKS. WINDS WILL START TO DECREASE THIS EVENING...BUT WILL PROBABLY CONTINUE AT LIGHT SPEEDS THROUGH THE OVERNIGHT HOURS. WHILE THERE MAY BE A DECREASE IN CLOUDS FOR THE FIRST PART OF TONIGHT...THE UPPER LEVEL TROUGH AXIS WILL BE PASSING THROUGH THE REGION FOR THE LATE NIGHT HOURS. BECAUSE OF THIS...WILL CONTINUE GO WITH AT LEAST SCT CLOUDS THROUGH THE OVERNIGHT HOURS. THE COMBINATION OF THESE PASSING CLOUDS...A LINGERING LIGHT BREEZE...AND A DRY BOUNDARY LAYER SHOULD PREVENT MUCH RADIATIONAL FOG FROM DEVELOPING TONIGHT. IF WINDS WERE TO DECOUPLE AND CLOUDS WERE LESS THAN EXPECTED...SOME PATCHES OF FOG COULD BE POSSIBLE...BUT CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INCLUDE IN THE TAF AT THIS TIME. DURING THE DAY ON THURSDAY...SCT-BKN CLOUDS WILL BE IN PLACE AT 4-5 KFT WILL CONTINUED VFR CONDITIONS. W-SW WINDS WILL BE AROUND 5-10 KTS. OUTLOOK... THURS NIGHT-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SUN NIGHT-MON: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A BROAD UPPER LEVEL LOW OVER SOUTHEASTERN CANADA AND THE NORTHEAST WILL BRING ISOLATED TO SCATTERED SHOWERS MAINLY NORTHWEST OF THE CAPITAL REGION TONIGHT INTO TOMORROW. HIGH PRESSURE WILL BUILD IN OVER NEW YORK AND NEW ENGLAND WITH CLEARING SKIES AND COOL CONDITIONS THURSDAY NIGHT. THIS SURFACE HIGH WILL YIELD FAIR AND DRY CONDITIONS FRIDAY INTO FIRST HALF OF THE WEEKEND WITH TEMPERATURES RETURNING TO ABOVE NORMAL READINGS FOR LATE AUGUST. THE RH VALUES WILL RISE CLOSE TO 100 PERCENT TOMORROW MORNING WITH SOME DEW FORMATION. THEY WILL LOWER TO 45 TO 60 PERCENT THURSDAY AFTERNOON...AND THEN INCREASE TO 90 TO 100 PERCENT FRIDAY MORNING. THE WINDS WILL BE FROM THE WEST TO NORTHWEST AT LESS THAN 10 MPH TONIGHT...AND THEN WILL INCREASE FROM THE NORTHWEST AT 10 TO 15 MPH THURSDAY AFTERNOON...AND THEN WILL BECOME LIGHT TO CALM BY FRIDAY MORNING. && .HYDROLOGY... NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS ENDING MONDAY. AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE REGION TONIGHT INTO TOMORROW BRINGING LIGHT ISOLATED TO SCATTERED SHOWERS PRIMARILY ACROSS THE SOUTHERN ADIRONDACKS. BASIN-AVERAGE RAINFALL VALUES ARE EXPECTED TO BE UNDER A QUARTER OF AN INCH. HIGH PRESSURE WILL BUILD IN ACROSS THE REGION THURSDAY NIGHT AND INTO THE WEEKEND RESULTING IN PRIMARILY DRY WEATHER FOR MOST OF THE HYDRO SERVICE AREA. A WEAK DISTURBANCE MAY BRING AN ISOLATED SHOWER OR THUNDERSTORM LATE SUNDAY ESPECIALLY WEST OF THE HUDSON RIVER VALLEY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...WASULA NEAR TERM...WASULA SHORT TERM...WASULA LONG TERM...LFM AVIATION...FRUGIS FIRE WEATHER...WASULA HYDROLOGY...SNYDER/WASULA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
348 PM EDT WED AUG 26 2015 .SYNOPSIS... HIGH PRESSURE ACROSS THE UPPER GREAT LAKES REGION WILL SETTLE ACROSS THE DELAWARE VALLEY BY FRIDAY AND THEN MOVE OFFSHORE THIS WEEKEND. A LOW PRESSURE SYSTEM AND FRONT WILL AFFECT THE WEATHER SUNDAY AND INTO EARLY MONDAY. MORE HIGH PRESSURE BUILDS ACROSS THE AREA NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... A GFS AND WRF-NMMB/NAM BLEND WOULD WORK THE BEST AS INITIALIZING AT 500MB EASTERN CONUS WHILE THE GFS REMAINS BETTER OUT WEST. THE SAME COMPROMISE WOULD WORK BEST AS A 925MB INITIALIZATION. BUT THE GFS ALONE LOOKED BETTER AT 850MB. THE INITIALIZATION DP/DT CONTINUES TO SHOW MORE RIDGING THAN FORECASTED IN THE WESTERN CONUS, BUT GENERALLY A FLATTER TROUGH IN THE EASTERN CONUS AND SOUTHEAST CANADA. GIVEN THE APPEARANCE OF THE CUMULUS AND CONTINUING CORROBORATION FROM RECENT HRRR RUNS, WE WILL KEEP THE ISOLATED SPRINKLES OVER THE FAR NORTHWEST FOR THE NEXT COUPLE OF HOURS. THE MAINLY CHANNELIZED VORT MAX IS EXPECTED TO REMAIN ACROSS THE NORTHWEST PART OF OUR CWA INTO THE OVERNIGHT, WITH THE LAST SHORT WAVE ROUNDING THE BASE OF THE TROF TOWARD MORNING. TENDENCY IS FOR WINDS TO BE LIGHTER THAN MODEL EXPECTATIONS PRECEDING THESE FEATURES ON ONE HAND. ON THE OTHER HAND, IT DOES RAISE THE UNCERTAINTY AS TO LINGERING CLOUDINESS, ESPECIALLY NORTHWEST. VISIBLE SATELLITE IS SHOWING PLENTY OF CLOUDINESS UPSTREAM AND SOME OF THE MORE HI RES MODELS DO KEEP LOW LEVEL MOISTURE GOING INTO THE EVENING. BUT, A TRAPPING INVERSION IS NOT BEING INDICATED. THUS THE FORECAST PLAN FOR THE NORTHWEST PART OF OUR CWA IS TO AVERAGE PARTLY CLOUDY FOR TONIGHT WITH A GENERALLY MORE HIGHER CONFIDENT AND CLEARER FORECAST SOUTHEAST. BOUNDARY LAYER WINDS ARE PREDICTED TO BE LIGHT ENOUGH FOR DECOUPLING, ESPECIALLY IN MORE SHELTERED AREAS. GIVEN THE AFTERNOON DEW POINTS, WE WENT WITH THE STAT GUIDANCE TREND OF LOWERING MINIMUM TEMPERATURES A BIT IN RURAL/OUTLYING AREAS. HIGHEST CONFIDENCE IS IN THE SOUTHERN PART OF OUR CWA. CLOUDS MAY MAKE OUR MINS NORTH TOO LOW. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... WITH THE LAST OF THE SHORT WAVES MOVING OFFSHORE BY EARLY AFTERNOON THURSDAY, THE TROF FLATTENING AND A HIGH PRESSURE SYSTEM BUILDING INTO THE EASTERN GREAT LAKES, EVEN MORE OF A CHAMBER OF COMMERCE LATE AUGUST DAY IS PREDICTED FOR OUR CWA. THE MODELS DO PASS THE 250MB JET OVER DELMARVA. THEY ARE NOT SHOWING ANY JET LAYER MOISTURE AT THIS TIME. CUMULUS COVERAGE OVERALL SHOULD BE LESS THAN TODAY. THE THERMAL TROF PASSES THROUGH AND THE PREDICTED THERMALS SUGGEST ABOUT A 1F DROP OFF IN MAX TEMPS FROM TODAY. USING PREDICTED 925MB TEMPS, WE WILL FOLLOW A GFS AND NAM MOS COMPROMISE. A BRIEF NORTHWEST SURGE BEHIND THE COLD FRONT SHOULD BECOME LIGHTER AGAIN. ALONG AND NEAR THE COAST AND BAYS, SOME SEA BREEZE INDUCED WINDS COULD DEVELOP. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... 5-WAVE MODEL GUIDANCE SHOWS A BUILDING SOUTHEAST RIDGE THROUGH A MAJORITY OF THE LONGTERM PERIOD WITH MODERATING TEMPERATURES AND HUMIDITY. FRIDAY - SATURDAY...EXPECTING A DRY FORECAST THESE DAYS WITH A WEAK FRONT NEARING FROM THE NORTHWEST. SOME GUIDANCE IS HINTING AT SHOWER ACTIVITY ACROSS THE NORTHERN SATURDAY AFTERNOON WITH A BIT OF A WEAKNESS IN THE PATTERN ALOFT BUT THINKING THAT CONVECTIVE TEMPERATURES SHOULD BE OUT OF REACH AND THE BETTER FORCING IS STILL FARTHER TO OUR NORTH AND WEST...WE STAY DRY. BOTH DAYS WE EXPECT TEMPERATURES IN THE MID-80S WITH DEWPOINTS CLOSE TO 60F. SUNDAY - MONDAY...THE AFOREMENTIONED COLD FRONT GETS CLOSER BUT WITH IT DOESN`T REALLY PACK A PUNCH BUT WE CONTINUE THE SLIGHT CHANCE WITH SOMEWHAT BETTER INSTABILITY. HIGH PRESSURE SLIDES OFF THE COAST AND ALLOWS FOR BETTER AIRMASS MODIFICATION SO WE WILL SEE AN INCREASE IN HUMIDITY AND INSTABILITY. HIGHS BOTH DAYS APPROACH, IF NOT EXCEED, 90F. TUESDAY - WEDNESDAY...NO APPRECIABLE RAIN EXPECTED EITHER DAY WITH SOUTHEAST RIDGE AXIS OVERHEAD. CONTINUED HEAT AND HUMIDITY INCREASE IS EXPECTED BUT IT DOES APPEAR THAT THE CORE OF THE WARMEST 925MB TEMPERATURES STAYS TO THE SOUTH AND WEST OF THE REGION. NONE-THE- LESS 90F IS NOT OUT OF THE QUESTION EACH AFTERNOON. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. 18Z TAFS WERE VFR. REST OF THIS AFTERNOON...A HIGH BASED CUMULUS DECK, BECOMING A CIG AT TIMES AT THE NORTHWEST TERMINALS AND AIRPORTS. WEST WINDS WILL BE CLOSE TO 10 KNOTS. THE SEA BREEZE FRONT IS EXPECTED TO REMAIN NEAR THE IMMEDIATE NJ AND DE COAST AND NOT MAKE IT INLAND OR TO KACY. TONIGHT...THE CUMULUS CLOUDS SHOULD DISSIPATE, ESPECIALLY I95 CORRIDOR SOUTHEAST. WINDS WILL BE LIGHT FROM THE NORTHWEST AND MORE SHELTERED AIRPORTS/TERMINALS MAY GO CALM FOR A WHILE. NO VSBY RESTRICTIONS AT THE TERMINALS. LATE TONIGHT ANOTHER UPPER AIR DISTURBANCE MIGHT BRING SOME MID LEVEL CLOUDS ACROSS THE AREA AGAIN. HIGHEST CONFIDENCE NORTHWEST AIRPORTS AND TERMINALS. THURSDAY...A NEAR CARBON COPY OF TODAY. SOME HIGH BASED CUMULUS CLOUDS SHOULD DEVELOP AGAIN, PROBABLY LESS OVERALL COVERAGE THAN TODAY. NORTHWEST WINDS SHOULD AVERAGE 5 TO 10 KNOTS. A SEA BREEZE FRONT DURING THE AFTERNOON MIGHT MAKE MORE OF AN INLAND INTRUSION. OUTLOOK... THURSDAY NIGHT THRU SATURDAY NIGHT...MOSTLY VFR. PATCHY FOG PSBL DURING THE PREDAWN HOURS. SUNDAY - MONDAY...MOSTLY VFR. SHOWERS POSSIBLE WITH LOWER CONDITIONS. && .MARINE... SUB SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE TONIGHT AND THURSDAY. SEA BREEZE INDUCED CIRCULATIONS LATE THIS AFTERNOON INTO THIS EVENING SHOULD BECOME A PREVAILING WEST TO NORTHWEST FLOW AGAIN TONIGHT. MESOSCALE MODELS HAVE THE STRONGEST (POSSIBLY EXCEEDING 15 KNOTS) SOUTHERLY FLOW EARLY OFF THE OCEAN AND ATLANTIC COUNTY COASTS WITH LESS VARIATION IN SPEEDS WITH THE NORTHWEST FLOW OVERNIGHT. AS THE OVERALL PRESSURE GRADIENT WEAKENS AGAIN DURING THE DAY ON THURSDAY, A MORE VARIABLE SEA BREEZE INDUCED WIND FLOW SHOULD DEVELOP AGAIN ON THE OCEAN WATERS. WE ARE NOT AS CERTAIN ABOUT AN UP (SOUTHEASTERLY WINDS) THE DELAWARE BAY FLOW OCCURRING. SUSTAINED WIND SPEEDS THURSDAY SHOULD REMAIN AT 15 KNOTS OR LESS. OUTLOOK... SUB-SCA CONDITIONS THRU THE PERIOD. SEAS WILL BUILD TO AROUND 4 FT ON THE OCEAN SAT NIGHT INTO SUNDAY. WIDELY SCT SHOWERS/TSTMS POSSIBLE SUN. && .RIP CURRENTS... WE WILL CONTINUE THE MODERATE RISK FOR THE FORMATION OF DANGEROUS RIP CURRENT ALONG THE NJ BEACHES FOR THE REST OF THE DAY. A MORE FAVORABLE WIND FLOW FOR STRONGER RIP CURRENTS IS STARTING TO DEVELOP. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...O`HARA NEAR TERM...GIGI SHORT TERM...GIGI LONG TERM...HEAVENER AVIATION...GIGI/HEAVENER/O`HARA MARINE...GIGI/HEAVENER/O`HARA RIP CURRENTS...GIGI
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
918 PM EDT THU AUG 27 2015 .UPDATE... 00Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE THE UPPER LEVEL PATTERN OVER THE EASTERN CONUS IS STILL DOMINATED BY A DEEP LONGWAVE TROUGH EXTENDING FROM THE EASTERN GREAT LAKES TO THE NORTH-CENTRAL GULF OF MEXICO. THIS TROUGH AXIS IS STILL OFF TO OUR NORTHWEST AND WEST AND SEPARATES A REGION OF VERY DRY MID/UPPER LEVEL AIR OVER MUCH OF THE SOUTHEAST CONUS...FROM A MOIST UPPER LEVEL ENVIRONMENT WITHIN THE SOUTHERN STREAM FLOW ON THE EASTERN SIDE OF THE TROUGH. THIS MOIST ENVIRONMENT COVERS THE ENTIRE FLORIDA PENINSULA AND HAS BEEN RESPONSIBLE FOR ANOTHER SHOWERY PERIOD ACROSS MANY OF OUR ZONES. AT THE SURFACE...THE GRADIENT IS QUITE WEAK OVER THE PENINSULA AND EASTERN GULF BETWEEN A WEAK SURFACE TROUGH OVER THE SOUTHERN GULF OF MEXICO AND CONTINENTAL HIGH PRESSURE TOWARD THE MID-ATLANTIC STATES. AS THIS HIGH BUILDS SOUTHWARD A BIT ON FRIDAY...OUR FLOW IN THE LOWER LEVELS WILL BECOME A BIT MORE DEFINED FROM THE SOUTHEAST. UNFORTUNATELY THIS IS NOT GOOD NEWS FOR THE SATURATED AREAS OF THE FORECAST AREA...AS SOUTHEAST FLOW IN THE SUMMER IS GENERALLY OUR FAVORED FLOW FOR THE MOST WIDESPREAD AND STRONG CONVECTION. WITH THAT IN MIND...AFTER A FAIRLY DRY PERIOD ACROSS THE LAND MASS THROUGH A GOOD PORTION OF TONIGHT...WE WILL BEGIN TO SEE INCREASING CHANCES FOR SHOWERS NEAR THE COAST AND OVER THE NEAR SHORE WATERS AS WE APPROACH DAWN. THE BEST CHANCE OF SHOWERS DURING THE MORNING HOURS WILL BE NEAR THE COAST...BUT BY AFTERNOON WITH THE DIURNAL HEATING...AND FAVORED WEST COAST SEA-BREEZE CONVERGENCE...DECENT COVERAGE OF SHOWERS AND STORMS WILL ONCE AGAIN BE IN THE FORECAST FOR MOST AREAS. SOME OF THE RAINFALL IS LIKELY TO BE ON THE HEAVY SIDE...AND CONDITIONS WILL NEED TO BE MONITORED CLOSELY...ESPECIALLY DOWN TOWARD CHARLOTTE AND LEE COUNTIES...WHERE SIGNIFICANT RAINFALL TOTALS HAVE BEEN SEEN OVER THE PAST 48 HOURS. && .AVIATION... 28/00Z-29/00Z. IN THE WAKE OF EARLIER SHRA/TSRA...PREVAILING VFR CONDITIONS HAVE DEVELOPED AT ALL TERMINALS. THIS TREND IS EXPECTED TO CONTINUE...WITH WINDS GRADUALLY SHIFTING TO THE SE/E OVERNIGHT. SCT SHRA/TSRA LOOK TO DEVELOP AGAIN FROM 14Z TO 18Z FRI... LINGERING INTO THE EVENING HOURS. MVFR/IFR CIGS AND GUSTY WINDS CAN BE EXPECTED IN AND AROUND THUNDERSTORMS. && .MARINE... WEAK GRADIENT ACROSS THE WATERS WILL CREATE WINDS LESS THAN 15 KNOTS WITH SEAS LESS THAN 3 FEET THROUGH AT LEAST SATURDAY. THE EVENTUAL TRACK AND INTENSITY OF TROPICAL STORM ERIKA WILL DETERMINE POTENTIAL INCREASES IN WINDS AND SEAS OVER THE WATERS BY THE EARLY PORTION OF NEXT WEEK. MAIN HAZARD THROUGH THE WEEKEND WILL BE SCATTERED MAINLY OVERNIGHT AND MORNING THUNDERSTORMS WHICH WILL CREATE LOCALLY GUSTY WINDS...AND FREQUENT CLOUD TO WATER LIGHTNING. && .PRELIMINARY POINT TEMPS/POPS... TPA 75 91 77 88 / 20 60 30 60 FMY 77 92 76 90 / 20 70 30 60 GIF 73 92 75 90 / 20 70 20 60 SRQ 77 90 76 88 / 30 60 30 60 BKV 74 91 74 87 / 20 60 20 60 SPG 78 91 79 88 / 20 60 30 60 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/MARINE...MROCZKA AVIATION...AUSTIN
AREA FORECAST DISCUSSION
NWS MIAMI FL
205 PM EDT WED AUG 26 2015 .AVIATION... ONGOING CONVECTION CONTINUES TO AFFECT MAINLY THE ATLANTIC COAST THIS AFTERNOON. LATEST HRRR ALSO KEEPS THIS TREND THROUGH THE EARLY EVENING HOURS WITH SOUTHWEST FLOW ALOFT. THEREFORE KEPT VCTS AT ALL EAST COAST SITES THROUGH 00Z. DEEP MOISTURE IS EXPECTED TO LINGER ACROSS ALL OF SOUTH FLORIDA THROUGH THE TAF PERIOD WITH VCSH/VCTS PREVAILING. && .PREV DISCUSSION... /ISSUED 945 AM EDT WED AUG 26 2015/ UPDATE...QUITE MOIST AND UNSTABLE ATMOSPHERE IN PLACE ACROSS S FLORIDA ALREADY THIS MORNING WITH THE 12Z SOUNDING SHOWING PWATS AROUND 2.3" ALONG WITH 700-500 MB LAPSE RATES DOWN TO 6C/KM AND 500MB A SLIGHTLY BELOW NORMAL -7C. CONVECTION HAS ALREADY BEEN QUITE PLENTIFUL OVER BOTH THE GULF AND ATLANTIC WATERS THIS MORNING WITH WEAK CONVERGENCE BAND TRACING OUT LOW LEVEL RIDGE AXIS ACROSS FL STRAITS AND FAR S FLORIDA. EXPECT AN ACTIVE DAY ACROSS THE REGION WITH SHOWERS AND STORMS INITIATING BY LATE MORNING/EARLY AFTERNOON. S-SW FLOW WILL HOLD BACK EAST COAST SEA BREEZE DEVELOPMENT AN HOUR OR TWO...BUT NOT STOP IT ALTOGETHER...AND ENHANCE GULF BREEZE. BEST RAIN CHANCES WILL BE OVER THE EASTERN INTERIOR WITH ACTIVITY MOVING OFF TO THE NORTH- NORTHEAST. PROFILE SUGGESTS THE POSSIBILITY FOR A FEW STRONGER STORMS WITH GUSTY WINDS AROUND 40MPH...FREQUENTLY HEAVY RAIN...AND LOCALLY HEAVY RAINFALL AS OVERALL STORM MOTION REMAINS SLOW. PREV DISCUSSION... /ISSUED 350 AM EDT WED AUG 26 2015/ DISCUSSION...THE MAJOR SYNOPTIC FEATURES ACROSS THE REGION INCLUDE A STATIONARY FRONT ACROSS THE NORTHERN GULF...A LARGE AMPLITUDE UPPER LEVEL TROUGH ACROSS THE EASTERN CONUS AND INTO THE CENTRAL GULF WITH DEEP TROPICAL MOISTURE ACROSS THE FLORIDA STRAITS AND INTO THE NORTHWEST BAHAMAS. IN ADDITION TROPICAL STORM ERIKA CONTINUES TO MOVE WESTWARD TOWARD THE LEEWARD ISLANDS. FOR TODAY AND THURSDAY...THE SURFACE TO LOW LEVEL SOUTHERLY WINDS WILL ADVECT IN DEEPER TROPICAL MOISTURE INTO THE REGION TODAY WHILE THE UPPER LEVEL TROUGH CONTINUES TO DEEPEN INTO THE GULF WITH SOUTH FLORIDA EAST OF THE TROUGH AXIS. THE FORECAST SOUNDINGS INDICATE REGIONAL PWATS AROUND 2.3 INCHES POSSIBLE TODAY WITH MID- LEVEL TEMPERATURES DECREASING TO A DEGREE OR SO BELOW SEASONAL NORMS. THE FORECAST SOUNDINGS ALSO INDICATE A LOCALLY UNSTABLE ATMOSPHERE BY 18Z WITH FORECAST STABILITY INDICES INDICATING GOOD POTENTIAL FOR CONVECTION. GIVEN ALL THESE FACTORS...SCATTERED TO NUMEROUS AFTERNOON SHOWERS/THUNDERSTORMS ARE EXPECTED ACROSS SOUTH FLORIDA WITH THE GREATEST COVERAGE IN THE INTERIOR REGIONS ALTHOUGH THE WEST AND EAST COAST METRO AREAS COULD EXPERIENCE WIDESPREAD ACTIVITY AS WELL IN ISOLATED AREAS. VERY SIMILAR CONDITIONS ARE FORECAST FOR THURSDAY...WITH THE AXIS OF THE UPPER LEVEL LOW STILL REMAINING IN THE NORTHERN TO CENTRAL GULF AND SOUTHERLY FLOW CONTINUING TO BRING TROPICAL MOISTURE INTO THE REGION. THURSDAY`S MID-LEVEL TEMPERATURES ARE FORECAST TO REMAIN COOLER THAN SEASONAL NORMS...WITH SCATTERED TO NUMEROUS AFTERNOON SHOWERS/THUNDERSTORMS WITH THE FOCUS AGAIN IN THE INTERIOR REGIONS AND CANNOT RULE OUT ACTIVE PERIODS FOR THE METRO AREAS. ITS WORTH NOTING THAT COVERAGE OF SHOWERS/THUNDERSTORMS IS EXPECTED TO INCREASE ACROSS THE REGIONAL WATERS OF SOUTH FLORIDA DURING THIS PERIOD. WITH REGARDS TO POSSIBLE IMPACTS FROM TROPICAL STORM ERIKA...THE OFFICIAL NATIONAL HURRICANE CENTER FORECAST IS FOR ERIKA TO TRACK WEST NORTHWEST OVER THE NEXT SEVERAL DAYS. THE CURRENT OFFICIAL FORECAST HAS ERIKA REACHING THE SOUTHEASTERN BAHAMAS AS A TROPICAL STORM BY SATURDAY EVENING AND INTO THE NORTHWEST BAHAMAS AS A HURRICANE ON SUNDAY EVENING. THERE IS MUCH UNCERTAINTY WITH REGARD TO THE TRACK AND INTENSITY OF ERIKA, SO THE EXTENDED FORECAST IS HIGHLY UNCERTAIN. GIVEN THE UNCERTAINTIES...POTENTIAL IMPACTS MAY NOT BE EXPECTED UNTIL LATE IN THE WEEKEND OR EARLY NEXT WEEK. ALL INTERESTS IN SOUTH FLORIDA NEED TO CLOSELY MONITOR THE PROGRESS OF TROPICAL STORM ERIKA AS IT TRACKS WEST NORTHWEST THE NEXT SEVERAL DAYS. MARINE...SOUTH TO SOUTHEASTERLY WINDS ARE FORECAST ACROSS THE REGIONAL WATERS TODAY THROUGH FRIDAY AND GENERALLY AROUND 10 KNOTS WITH REGIONAL SEAS 2 FEET OR LESS THROUGH THIS PERIOD. FOR THE UPCOMING WEEKEND...ONCE AGAIN THERE IS CONSIDERABLE UNCERTAINTY DUE TO POSSIBLE IMPACTS FROM TROPICAL STORM ERIKA. THE CURRENT FORECAST HAS THE GREATEST IMPACTS LATE SUNDAY INTO MONDAY ACROSS THE LOCAL ATLANTIC WATERS...BUT NEED TO STRESS AGAIN THE CONSIDERABLE UNCERTAINTY. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 90 79 92 / 60 70 40 60 FORT LAUDERDALE 78 90 79 91 / 60 70 40 50 MIAMI 77 90 79 92 / 60 60 30 50 NAPLES 77 89 77 92 / 50 60 40 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ AVIATION...10/CD UPDATE...88/ALM
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
230 PM EDT WED AUG 26 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN STALLED JUST TO OUR SOUTH THROUGH FRIDAY. INCREASING ATMOSPHERIC MOISTURE WILL DRIFT NORTH INTO OUR REGION THIS WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE UPPER TROUGH WILL REMAIN OVER THE EASTERN CONUS WITH THE TROUGH AXIS WEST OF THE APPALACHIANS. A DIFFUSE FRONTAL BOUNDARY WILL LINGER NEAR THE COAST WITH A WEAK WAVE OF LOW PRESSURE OVER SOUTHEASTERN SOUTH CAROLINA. VISIBLE SATELLITE DENOTED AN EAST/WEST BOUNDARY ACROSS THE SOUTHERN MIDLANDS AND CSRA. DEWPOINTS WERE IN THE UPPER 50S AND LOWER 60S NORTH OF THE BOUNDARY AND IN THE LOWER 70S TO THE SOUTH. PWAT VALUES RANGED FROM JUST UNDER AN INCH ACROSS THE PIEDMONT AND CSRA TO 1.6 INCHES OVER THE EASTERN MIDLANDS. INSTABILITY REMAINED WEAK ACROSS THE NORTHERN AND CENTRAL MIDLANDS. WEAK TO MODERATE INSTABILITY WILL CONTINUE ACROSS THE EASTERN AND SOUTHERN PORTION OF THE FORECAST AREA. WE KEPT A SLIGHT CHANCE FOR A SHOWER OR THUNDERSTORM FOR THE EASTERN COUNTIES WHERE MOISTURE AND INSTABILITY IS GREATEST. AFTERNOON HIGH TEMPERATURES ARE FORECAST IN THE UPPER 80S TO LOWER 90S. ANY LINGERING SHOWERS/STORMS EARLY THIS EVENING ACROSS THE EAST ARE EXPECTED TO DISSIPATE RATHER QUICKLY BY MIDNIGHT...WITH MAJORITY OF THE AREA DRY TONIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... MAIN UPPER TROUGH JUST TO OUR WEST WILL BEGIN GRADUALLY WEAKENING AND LIFTING NORTH...BUT STILL LEAVING BEHIND A WEAK UPPER TROUGH TO OUR WEST AND CUT OFF LOW IN THE GULF OF MEXICO...WHILE UPPER RIDGE OVER THE WESTERN ATLANTIC BEGINS TO BUILD WESTWARD TOWARDS THE SE COAST. SURFACE FRONT IS EXPECTED TO REMAIN NEARLY STATIONARY NEAR THE COAST...WHILE SURFACE HIGH PRESSURE SHIFTS EAST FROM THE MIDWEST INTO THE MID ATLANTIC....AND SURFACE WAVE NEAR THE SC COAST SHIFTS SW TOWARDS THE GULF COAST. MODELS PROG DRY AIR AT MID AND UPPER LEVELS TO REMAIN IN PLACE...WHILE LOW LEVELS GRADUALLY MOISTEN OVER PORTIONS OF THE FORECAST AREA (FA) DUE TO AN E TO NE LOW LEVEL FLOW OFF THE ATLANTIC. HOWEVER...RELATIVELY DRY LOW LEVEL AIR MAY REMAIN ENTRENCHED ACROSS THE NORTHERN FA AS SURFACE HIGH RIDGES FROM THE MID ATLANTIC INTO THE WESTERN CAROLINAS. WEAK TO MODERATE MAINLY DIURNAL INSTABILITY PROGGED. SLIGHT CHANCE TO LOW CHANCE POPS APPEAR IN ORDER FAVORING THE SOUTHERN FA. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... SAT/SUN...MODELS INDICATE MAIN BELT OF UPPER WESTERLIES TO REMAIN WELL TO THE NORTH WITH EMBEDDED SHORTWAVE SHIFTING EAST FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST/GREAT LAKES REGION. THIS ALONG WITH INDICATIONS OF WEAK UPPER TROUGHINESS REMAINING TO OUR WEST....WITH SUBTROPICAL RIDGE REMAINING OVER THE WESTERN ATLANTIC AND BUILDING TOWARDS THE SE COAST SOME...APPEARS TO DRAW MOISTURE FROM THE GULF AND ATLANTIC NORTHWARD INTO OUR REGION. SO...WILL MAINTAIN TREND TOWARDS INCREASING POPS FOR OUR REGION SAT/SUN. ACCEPTED HPC GUIDANCE OF CHANCE TO POSSIBLY LOW END LIKELY POPS. EARLY TO MID NEXT WEEK...MODELS GENERALLY MAINTAIN WEAK UPPER TROUGH TO OUR WEST AND SUBTROPICAL UPPER RIDGE TO OUR SE. MAIN CONCERN FOR THIS TIME PERIOD WILL BE TROPICAL CYCLONE ERIKA. LATEST OFFICIAL FORECAST FROM NHC BRINGS IT NW ACROSS THE BAHAMAS AS A TROPICAL STORM SUN/SUN NT THEN STRENGTHEN IT TO A LOW END HURRICANE AND MOVING IT INTO S FL BY EARLY MONDAY. GENERAL MODEL CONSENSUS HAS IT DRIFTING TO THE NORTH THEREAFTER. FOR NOW...DUE TO UNCERTAINITES REGARDING IMPACT FOR OUR REGION...WILL MAINTAIN CHANCE POPS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR EXPECTED THROUGH THE AFTERNOON AND EVENING. A NEARLY STATIONARY BOUNDARY WAS SOUTH AND EAST OF THE TAF SITES. DRY AIR WILL CONTINUE OVER MUCH OF THE NORTHERN AND CENTRAL MIDLANDS AS HIGH PRESSURE RIDGES IN FROM THE NORTHWEST. CANNOT RULE OUT ISOLATED AFTERNOON/EVENING CONVECTION NEAR OGB...BUT CONFIDENCE TOO LOW TO INCLUDE IN TAF GIVEN WEAK INSTABILITY AND MODEST MOISTURE. AREAS OF LATE NIGHT FOG/STRATUS POSSIBLE TONIGHT. WENT WITH PERSISTENCE FOR A PERIOD OF MVFR CIGS/VSBYS 06Z-14Z. BOTH THE NAM AND RAP MODELS ALSO INDICATED LOW CLOUDS DEVELOPING LATE TONIGHT. ANY FOG/STRATUS THAT DEVELOP SHOULD LIFT 14Z-16Z...WITH VFR CONDITIONS RETURNING BY MIDDAY. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY MORNING FOG/STRATUS AND AFTERNOON AND EVENING ISOLATED TO SCATTERED THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
713 AM EDT WED AUG 26 2015 .SYNOPSIS... A WEAK COLD FRONT AND ASSOCIATED AREA OF LOW PRESSURE WILL STALL AND DISSIPATE ALONG THE SOUTHEAST COAST THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE IN NORTH OF THE REGION INTO FRIDAY BEFORE MOVING OFF THE EAST COAST THIS WEEKEND. ANOTHER AREA OF HIGH PRESSURE WILL BUILD ACROSS THE SOUTHERN APPALACHIANS INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE SUNRISE UPDATE...SOME FAIRLY SIZABLE ADJUSTMENTS TO HOURLY DEWPOINTS AND TEMPERATURES WERE MADE ACROSS THE WESTERN TWO THIRDS OF THE FORECAST AREA AS THE FRONT HAS PUSHED A BIT FARTHER EAST THAN EXPECTED. THE H3R AND RAP HAVE BACKED OFF CONSIDERABLY FROM EARLIER RUNS ON THE AMOUNT OF SHOWERS/TSTMS WILL DEVELOP OVER THE CHARLESTON TRI-COUNTY AREA DURING PEAK HEATING. THIS IS A BIT PUZZLING GIVEN THE FAVORABLE ORIENTATION OF THE COLD FRONT AND ITS LIKELY INTERACTIONS WITH THE SEA BREEZE CIRCULATION. MAINTAINED POPS AS THEY WERE ADVERTISED EARLIER...BUT IF THIS DRIER TREND CONTINUES...THEN LOWER POPS MAY BE NEEDED IN SUBSEQUENT FORECAST UPDATES. 26/10Z SURFACE ANALYSIS PLACED 1010 MB LOW PRESSURE BETWEEN MANNING AND GEORGETOWN WITH A QUASI-STATIONARY FRONT STRETCHING FROM THE NORTH CAROLINA COASTAL PLAIN SOUTH THROUGH THE WESTERN PEE DEE INTO THE FAR SOUTHERN MIDLANDS. THE BOUNDARY THEN ARCS BACK TO SAVANNAH...JESUP AND INTO THE EASTERN FLORDIA PANHANDLE. THE FRONT WILL MOVE LITTLE TODAY...ONLY INCHING EVER SO SLOWLY TO THE EAST. THIS WILL KEEP AREAS ROUGHLY ALONG/EAST OF I-95 IN THE CONCEPTUAL WARM SECTOR WITH THE FRONT ESSENTIALLY DELINEATING DEWPOINTS IN THE LOWER-MID 70S FROM DEWPOINTS IN THE LOWER-MID 60S. ALOFT...A TROUGH OF LOW PRESSURE IS FORECAST TO DIG ACROSS THE CENTRAL AND SOUTHERN APPALACHIANS THIS AFTERNOON AS 500 HPA LOW PRESSURE TREKS NORTH OF THE GREAT LAKES. A SLIGHT COOLING OF 500 HPA TEMPERATURES WILL TAKE PLACE BY MID AFTERNOON AS THE MID-LEVEL TROUGH DRAWS CLOSER. THIS COUPLED WITH MODERATE TO LOCALLY STRONG INSTABILITY AND SOME UPPER DIFLUENCE INDUCED BY THE RIGHT ENTRANCE REGION OF THE UPPER JET OVER EASTERN NORTH CAROLINA AND VIRGINIA WILL SUPPORT ISOLATED-SCATTERED SHOWERS/TSTMS ACROSS EASTERN AREAS. ACTIVITY LOOKS TO BECOME ENHANCED ACROSS THE CHARLESTON TRI-COUNTY AREA WHERE LOW-LEVEL CONVERGENCE BECOMES MAXIMIZED NEAR THE SEA BREEZE/FRONTAL INTERSECTION. SBCAPE IS FORECAST TO RISE TO 3200-3600 J/KG IN THIS AREA PER KCHS MODIFIED RAP/NAM12 SOUNDINGS WITH DCAPE REACHING 1200-1500 J/KG. ALTHOUGH MID-LAPSE RATES ARE NOT OVERLY COLD AND 0-6KM BULK SHEAR IS WEAK...THERE IS ENOUGH LOW-LEVEL INSTABILITY AND DCAPE IN PLACE TO SUPPORT ISOLATED SEVERE TSTMS...ESPECIALLY WHERE UPDRAFTS BECOME ENHANCED BY MESOSCALE BOUNDARY COLLISIONS. LOCALLY DAMAGING WINDS AND CLOUD TO GROUND LIGHTNING WILL BE PRIMARY HAZARDS. 20-50 PERCENT POPS LOOK FINE FOR AREAS ALONG/EAST OF THE I-95 CORRIDOR WITH THE HIGHEST POPS CENTERED OVER THE CHARLESTON TRI- COUNTY AREA. LOCALLY HIGHER POPS MAY EVENTUALLY BE NEEDED AS MESOSCALE TRENDS BECOME MORE APPARENT. FORECAST SOUNDINGS LOOK TOO CAPPED TO SUPPORT MEASURABLE RAINFALL BEHIND THE FRONT AS DEWPOINTS FALL INTO THE LOWER-MID 60S AND 700 HPA THETA-E LOWERS. WILL MAINTAIN DRY CONDITIONS THERE...ROUGHLY ALONG/WEST OF A HAMPTON-PEMBROKE-LUDOWICI LINE. HIGHS WILL BE FAIRLY UNIFORM ACROSS THE FRONT...PEAKING IN THE LOWER 90 AWAY FROM THE BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... TONIGHT...THE FRONT WILL MOVE LITTLE OVERNIGHT AS LOW PRESSURE MEANDERS TO THE SOUTHWEST ALONG THE BOUNDARY. THIS WILL KEEP MOST OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA IN THE WARM SECTOR WITH THE EXCEPTION OF FAR INTERIOR SOUTHEAST GEORGIA. CONVECTION LOOKS DIE OFF RATHER QUICKLY THIS EVENING WITH THE LOSS OF INSOLATION AND THE LOW-LEVEL CONVERGENCE MAXIMUM SHIFTING BACK INTO THE COASTAL WATERS. SOME ISOLATED TO PERHAPS SCATTERED CONVECTION MAY RE-FIRE ALONG THE BEACHES AND CHARLESTON TRI-COUNTY AREA AFTER MIDNIGHT AS LOW-LEVEL CONVERGENCE RE- INTENSIFIES JUST OFF THE LOWER SOUTH CAROLINA COAST. WILL KEEP 20/30 PERCENT POPS IN PLACE ACROSS THE COASTAL ZONES TO ACCOUNT FOR THIS POSSIBILITY. LOWS WILL RANGE FROM THE UPPER 60S/NEAR 70 ACROSS FAR INTERIOR SOUTHEAST GEORGIA TO THE UPPER 70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON. THERE ARE SIGNALS THAT SOME POST-FRONTAL LOW STRATUS AND POSSIBLY FOG COULD OOZE OUT OF THE PEE DEE AND EASTERN MIDLANDS AND AFFECT THE INTERIOR SOUTH CAROLINA ZONES EARLY TUESDAY MORNING. IT IS UNCLEAR ATTM WHETHER THIS WILL OCCUR...BUT THIS WILL NEED TO BE WATCHED CAREFULLY. THURSDAY AND FRIDAY...THE PERSISTENT UPPER TROUGH THAT HAS BEEN ACROSS MUCH OF THE EASTERN U.S. WILL BEGIN TO WEAKEN AND MOVE WEST- SOUTHWEST AS A DEEP LAYER ATLANTIC RIDGE ALSO STARTS TO BUILD FROM THE EAST. AT THE SURFACE...HIGH PRESSURE BUILDS ACROSS THE NORTHEAST AND THE MID ATLANTIC ON THURSDAY THEN SHIFTS OFF SHORE BY FRIDAY. THE LOW LEVEL FLOW WILL START OFF EAST-NORTHEAST THURSDAY...VEERING TO SOUTHEAST BY FRIDAY. DEEP LAYER MOISTURE WILL BE MARGINAL THURSDAY...AND HAVE GONE LOW END CHANCE POPS ACROSS MUCH OF THE AREA FOR AFTERNOON CONVECTION. BY FRIDAY...DEEP LAYER MOISTURE INCREASES SLIGHTLY ALONG WITH THE CHANCES FOR CONVECTION. WITH LITTLE/NO UPPER FORCING...EXPECT CONVECTION TO DIE DOWN IN THE EVENING BOTH DAYS...BUT LEFT SLIGHT CHANCE TO LOW END CHANCE POPS CLOSER TO THE COAST WITH ONSHORE FLOW BRINING IN MOISTURE AND THE POTENTIAL FOR SHOWERS. HIGHS BOTH DAYS IN THE UPPER 80S TO AROUND 90...AND LOWS IN THE LOWER TO MID 70S. SATURDAY...THE SURFACE RIDGE CONTINUES TO PUSH EASTWARD OFF THE MID ATLANTIC COAST WHILE THE UPPER RIDGE BUILDS WESTWARD FROM THE ATLANTIC. THIS SETS UP A SOUTHEAST LOW LEVEL FLOW...WHICH ALSO HELPS TO ADVECT IN BETTER DEEP LAYER MOISTURE. HAVE GONE CHANCE POPS ENTIRE AREA...BUT WOULD NOT BE SURPRISED IF LATER FORECASTS RAISE POPS FURTHER. HIGHS AGAIN IN THE UPPER 80S TO AROUND 90. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... THE PERIOD STARTS OFF WITH THE REGION BEING SQUEEZED BETWEEN A DEEP LAYER ATLANTIC RIDGE CENTERED WELL EAST OF THE AREA AND AN UPPER LEVEL TROUGH MOVING INTO THE OHIO AND TENNESSEE RIVER VALLEYS. THESE TWO FEATURES HELP TO FOCUS SUFFICIENT DEEP LAYER MOISTURE ACROSS THE REGION FOR SUNDAY. THIS MOISTURE...ALONG WITH SOME FORCING FROM THE UPPER TROUGH TO THE NORTHWEST SHOULD RESULT IN SCATTERED CONVECTION BY AFTERNOON. KEPT POPS CONSERVATIVE FOR IN THE MID TO HIGH END CHANCE RANGE. BY LATER SUNDAY AND BEYOND IS WHEN THE GLOBAL MODELS BEGIN TO REALLY DIVERGE IN THE LARGE SCALE PATTERN. THE GFS WEAKENS THE UPPER TROUGH TO THE NORTHWEST AND LEAVES THE AREA LARGELY DOMINATED BY ATLANTIC HIGH PRESSURE THROUGH MID WEEK...WHILE THE ECMWF HOLDS ONTO THE UPPER TROUGH TO THE NORTHWEST LONGER. THESE DIFFERENCES MAY BECOME VERY IMPORTANT SINCE THEY WILL HAVE A LARGE INFLUENCE ON WHERE ERIKA /OR THE REMNANTS OF/ TRACK. THE GFS CONTINUES TO SIGNIFICANTLY WEAKEN THE CIRCULATION ASSOCIATED WITH ERIKA AND MOVES IT ACROSS CUBA AND THE FLORIDA STRAIGHTS MONDAY AND TUESDAY...THEN LOSES IT SOMEWHERE OVER NORTHERN FLORIDA AND OFF THE OUR ATLANTIC COAST BY WEDNESDAY. THE ECMWF IS MUCH STRONGER WITH THE SYSTEM AND HAS A MORE EASTERLY TRACK OVER THE FLORIDA PENINSULA EARLY NEXT WEEK THEN STALLING OFF THE NORTHEAST FLORIDA COAST. THAT BEING SAID...WE WILL CONTINUE TO MONITOR BOTH THE LATEST MODEL TRENDS CONCERNING THE FATE OF ERIKA AS WELL AS OFFICIAL FORECASTS FROM THE NATIONAL HURRICANE CENTER. FOR NOW...GIVEN THE EXTREME UNCERTAINTY IN PATTERN...HAVE KEPT CHANCES POPS FOR MUCH OF THE PERIOD WITH TEMPERATURES AROUND NORMAL. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... VFR. MODELS ARE SHOWING A SIMILAR SIGNAL THAT SCATTERED TSTMS WILL LIKELY IMPACT AREAS AROUND KCHS BY EARLY/MID AFTERNOON. TIMING IS STILL A BIT IN QUESTION...BUT CONFIDENCE IS HIGH ENOUGH ATTM TO INCLUDE A TEMPO GROUP FROM 19-22Z FOR 4SM -TSRA. TSTMS PROBABILITIES ARE TOO LOW AT KSAV THIS FAR OUT TO INCLUDE A MENTION FOR THE 06Z TAF CYCLE. EXTENDED AVIATION OUTLOOK...THURSDAY AND FRIDAY...VFR WILL DOMINATE WITH ISOLATED TO SCATTERED MAINLY AFTERNOON CONVECTION WITH BRIEF FLIGHT RESTRICTIONS POSSIBLE. SATURDAY AND SUNDAY...DEEP LAYER MOISTURE INCREASES AS AN UPPER TROUGH BUILDS TO THE NORTHWEST AND CHANNELS MOISTURE NORTHWARD. THIS SHOULD TRANSLATE TO HIGHER CHANCES FOR CONVECTION AND POTENTIAL FOR BRIEF FLIGHT RESTRICTIONS. EARLY TO MID NEXT WEEK...THERE CONTINUES TO BE LARGE DIFFERENCES IN THE MODELS AS TO THE POTENTIAL TRACK AND STRENGTH OF WHAT IS CURRENTLY ERIKA. FOR NOW EXPECT AT LEAST ISOLATED TO SCATTERED CONVECTION MAINLY DURING THE AFTERNOON...BUT WILL CONTINUE TO CLOSELY WATCH LATEST MODEL TRENDS AND OFFICIAL FORECASTS FROM THE NATIONAL HURRICANE CENTER CONCERNING ERIKA. && .MARINE... TODAY...SOUTHWEST WINDS THIS MORNING WILL BACK SOUTH THIS AFTERNOON AS A COLD FRONT APPROACHES THE COAST. LOCAL SEA BREEZE ENHANCEMENTS ARE LIKELY...MAINLY NEAR THE LAND/SEA INTERFACE AND CHARLESTON HARBOR. WINDS WILL HOLD AROUND 10 KT...LOCALLY HIGHER NEAR THE COAST. SEAS WILL AVERAGE 2-3 FT...MAINLY COMPRISED 10-11 SECOND SWELL FROM THE EAST. TONIGHT...A BIT OF A NOCTURNAL SURGE IS EXPECTED ACROSS THE GEORGIA WATERS AS THE COLD FRONT HOLDS NEARLY STATIONARY. WINDS ACROSS THE SOUTH CAROLINA WATERS WILL BE A BIT LIGHTER GIVEN THE ORIENTATION OF THE LOW-LEVEL JET. EXPECT WINDS TO PEAK 15-20 KT GEORGIA WATERS WITH 5-10 KT CHARLESTON COUNTY WATERS WITH 10-15 KT BEAUFORT COUNTY WATERS. SEAS WILL HOLD 2-3 FT...MAINLY COMPRISED OF 10-11 SECOND SWELL FROM THE EAST. THURSDAY THROUGH MONDAY NIGHT...NO HIGHLIGHTS EXPECTED THROUGH EARLY NEXT WEEK. HIGH PRESSURE WILL REMAIN NORTH OF THE WATERS THROUGH SATURDAY WITH EAST- SOUTHEAST WINDS OF 15 KTS OR LESS AND SEAS 3 FEET OR LESS. BY SUNDAY AND MONDAY...HIGH PRESSURE SHIFTS FURTHER EAST OF THE AREA AND WINDS VEER TO SOUTHEAST TO SOUTH...BUT REMAIN 15 KTS OR LESS AND SEAS 3 TO 4 FEET OR LESS. THE BIG QUESTION AND UNCERTAINTY WITH THE LATER PART OF THE FORECAST PERIOD AND INTO MID NEXT WEEK IS THE FATE OF ERIKA. LATEST GLOBAL MODEL GUIDANCE CONTINUES TO DIFFER ON THE STRENGTH AND EVENTUAL PATH. STAY TUNED TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER CONCERNING ERIKA. WATERSPOUTS...ATMOSPHERIC CONDITIONS ARE GENERALLY SUPPORTIVE OF WATERSPOUTS THIS MORNING. THERE ARE HINTS IN THE RAP THAT A CLOUD LINE OR LAND BREEZE CIRCULATION COULD DEVELOP OFF THE GEORGIA AND FAR SOUTHERN SOUTH CAROLINA COAST AROUND SUNRISE...WHICH COULD FOCUS THE WATERSPOUT POTENTIAL. WINDS ARE FORECAST TO BE A TAD TOO HIGH FOR A MORE SIGNIFICANT RISK...BUT THE OVERALL ASSESSMENT POINTS TO A MODERATE RISK FOR WATERSPOUTS. WILL INCLUDE A MENTION IN THE HAZARDOUS WEATHER OUTLOOK. A MARINE WEATHER STATEMENT MAY ALSO BE ISSUED IF THE FORMATION OF THE LAND BREEZE CIRCULATION OCCURS. && .TIDES/COASTAL FLOODING... CONTINUE TO MONITOR THE POTENTIAL FOR MINOR COASTAL FLOODING DURING THE MAJOR HIGH TIDES THURSDAY THROUGH MID NEXT WEEK DUE TO ELEVATED ASTRONOMICAL FROM THE UPCOMING PERIGEAN TIDES. THE LATEST EXTRA- TROPICAL SURGE GUIDANCE ALREADY SHOWING MARGINAL COASTAL FLOODING TIDE LEVELS FOR CHARLESTON THURSDAY THROUGH SATURDAY...AND VERY CLOSE AT FORT PULASKI. THIS IS LIKELY DUE TO EASTERLY LOW LEVEL WINDS THAT HELP INCREASE THE ALREADY HIGH TIDES. HARD TO TELL HOW MUCH INFLUENCE THE LOW LEVEL WINDS WILL HAVE LATER THIS WEEKEND AND INTO EARLY NEXT WEEK AS THERE IS CONSIDERABLE UNCERTAINTY WITH THE TRACK AND INTENSITY OF ERIKA. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST/RFM
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
418 AM EDT WED AUG 26 2015 .SYNOPSIS... A WEAK COLD FRONT AND ASSOCIATED AREA OF LOW PRESSURE WILL STALL AND DISSIPATE ALONG THE SOUTHEAST COAST THROUGH THURSDAY. HIGH PRESSURE WILL SETTLE IN NORTH OF THE REGION INTO FRIDAY BEFORE MOVING OFF THE EAST COAST THIS WEEKEND. ANOTHER AREA OF HIGH PRESSURE WILL BUILD ACROSS THE SOUTHERN APPALACHIANS INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 26/07Z SURFACE ANALYSIS PLACED 1011 MB LOW PRESSURE NEAR MANNING...SOUTH CAROLINA WITH A STATIONARY FRONT EXTENDING FROM THE COASTAL PLAIN OF NORTH CAROLINA THROUGH THE WESTERN PEE DEE...INTO THE SOUTHERN MIDLANDS THEN TURNING SOUTH THROUGH INTERIOR SOUTHEAST GEORGIA AND THE EASTERN FLORIDA PANHANDLE. THE FRONT WILL MOVE LITTLE TODAY...ONLY INCHING EVER SO SLOWLY TO THE EAST. THIS WILL KEEP AREAS ROUGHLY ALONG/EAST OF I-95 IN THE CONCEPTUAL WARM SECTOR WITH THE FRONT ESSENTIALLY DELINEATING DEWPOINTS IN THE LOWER-MID 70S FROM DEWPOINTS IN THE LOWER-MID 60S. ALOFT...A TROUGH OF LOW PRESSURE IS FORECAST TO DIG ACROSS THE CENTRAL AND SOUTHERN APPALACHIANS THIS AFTERNOON AS 500 HPA LOW PRESSURE TREKS NORTH OF THE GREAT LAKES. A SLIGHT COOLING OF 500 HPA TEMPERATURES WILL TAKE PLACE BY MID AFTERNOON AS THE MID-LEVEL TROUGH DRAWS CLOSER. THIS COUPLED WITH MODERATE TO LOCALLY STRONG INSTABILITY AND SOME UPPER DIFLUENCE INDUCED BY THE RIGHT ENTRANCE REGION OF THE UPPER JET OVER EASTERN NORTH CAROLINA AND VIRGINIA WILL SUPPORT ISOLATED-SCATTERED SHOWERS/TSTMS ACROSS EASTERN AREAS. ACTIVITY LOOKS TO BECOME ENHANCED ACROSS THE CHARLESTON TRI-COUNTY AREA WHERE LOW-LEVEL CONVERGENCE BECOMES MAXIMIZED NEAR THE SEA BREEZE/FRONTAL INTERSECTION. SBCAPE IS FORECAST TO RISE TO 3200-3600 J/KG IN THIS AREA PER KCHS MODIFIED RAP/NAM12 SOUNDINGS WITH DCAPE REACHING 1200-1500 J/KG. ALTHOUGH MID-LAPSE RATES ARE NOT OVERLY COLD AND 0-6KM BULK SHEAR IS WEAK...THERE IS ENOUGH LOW-LEVEL INSTABILITY AND DCAPE IN PLACE TO SUPPORT ISOLATED SEVERE TSTMS...ESPECIALLY WHERE UPDRAFTS BECOME ENHANCED BY MESOSCALE BOUNDARY COLLISIONS. LOCALLY DAMAGING WINDS AND CLOUD TO GROUND LIGHTNING WILL BE PRIMARY HAZARDS. 20-50 PERCENT POPS LOOK FINE FOR AREAS ALONG/EAST OF THE I-95 CORRIDOR WITH THE HIGHEST POPS CENTERED OVER THE CHARLESTON TRI- COUNTY AREA. LOCALLY HIGHER POPS MAY EVENTUALLY BE NEEDED AS MESOSCALE TRENDS BECOME MORE APPARENT. FORECAST SOUNDINGS LOOK TOO CAPPED TO SUPPORT MEASURABLE RAINFALL BEHIND THE FRONT AS DEWPOINTS FALL INTO THE LOWER-MID 60S AND 700 HPA THETA-E LOWERS. WILL MAINTAIN DRY CONDITIONS THERE...ROUGHLY ALONG/WEST OF A HAMPTON-PEMBROKE-LUDOWICI LINE. HIGHS WILL BE FAIRLY UNIFORM ACROSS THE FRONT...PEAKING IN THE LOWER 90 AWAY FROM THE BEACHES. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/... TONIGHT...THE FRONT WILL MOVE LITTLE OVERNIGHT AS LOW PRESSURE MEANDERS TO THE SOUTHWEST ALONG THE BOUNDARY. THIS WILL KEEP MOST OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA IN THE WARM SECTOR WITH THE EXCEPTION OF FAR INTERIOR SOUTHEAST GEORGIA. CONVECTION LOOKS DIE OFF RATHER QUICKLY THIS EVENING WITH THE LOSS OF INSOLATION AND THE LOW-LEVEL CONVERGENCE MAXIMUM SHIFTING BACK INTO THE COASTAL WATERS. SOME ISOLATED TO PERHAPS SCATTERED CONVECTION MAY RE-FIRE ALONG THE BEACHES AND CHARLESTON TRI-COUNTY AREA AFTER MIDNIGHT AS LOW-LEVEL CONVERGENCE RE- INTENSIFIES JUST OFF THE LOWER SOUTH CAROLINA COAST. WILL KEEP 20/30 PERCENT POPS IN PLACE ACROSS THE COASTAL ZONES TO ACCOUNT FOR THIS POSSIBILITY. LOWS WILL RANGE FROM THE UPPER 60S/NEAR 70 ACROSS FAR INTERIOR SOUTHEAST GEORGIA TO THE UPPER 70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON. THERE ARE SIGNALS THAT SOME POST-FRONTAL LOW STRATUS AND POSSIBLY FOG COULD OOZE OUT OF THE PEE DEE AND EASTERN MIDLANDS AND AFFECT THE INTERIOR SOUTH CAROLINA ZONES EARLY TUESDAY MORNING. IT IS UNCLEAR ATTM WHETHER THIS WILL OCCUR...BUT THIS WILL NEED TO BE WATCHED CAREFULLY. THURSDAY AND FRIDAY...THE PERSISTENT UPPER TROUGH THAT HAS BEEN ACROSS MUCH OF THE EASTERN U.S. WILL BEGIN TO WEAKEN AND MOVE WEST- SOUTHWEST AS A DEEP LAYER ATLANTIC RIDGE ALSO STARTS TO BUILD FROM THE EAST. AT THE SURFACE...HIGH PRESSURE BUILDS ACROSS THE NORTHEAST AND THE MID ATLANTIC ON THURSDAY THEN SHIFTS OFF SHORE BY FRIDAY. THE LOW LEVEL FLOW WILL START OFF EAST-NORTHEAST THURSDAY...VEERING TO SOUTHEAST BY FRIDAY. DEEP LAYER MOISTURE WILL BE MARGINAL THURSDAY...AND HAVE GONE LOW END CHANCE POPS ACROSS MUCH OF THE AREA FOR AFTERNOON CONVECTION. BY FRIDAY...DEEP LAYER MOISTURE INCREASES SLIGHTLY ALONG WITH THE CHANCES FOR CONVECTION. WITH LITTLE/NO UPPER FORCING...EXPECT CONVECTION TO DIE DOWN IN THE EVENING BOTH DAYS...BUT LEFT SLIGHT CHANCE TO LOW END CHANCE POPS CLOSER TO THE COAST WITH ONSHORE FLOW BRINING IN MOISTURE AND THE POTENTIAL FOR SHOWERS. HIGHS BOTH DAYS IN THE UPPER 80S TO AROUND 90...AND LOWS IN THE LOWER TO MID 70S. SATURDAY...THE SURFACE RIDGE CONTINUES TO PUSH EASTWARD OFF THE MID ATLANTIC COAST WHILE THE UPPER RIDGE BUILDS WESTWARD FROM THE ATLANTIC. THIS SETS UP A SOUTHEAST LOW LEVEL FLOW...WHICH ALSO HELPS TO ADVECT IN BETTER DEEP LAYER MOISTURE. HAVE GONE CHANCE POPS ENTIRE AREA...BUT WOULD NOT BE SURPRISED IF LATER FORECASTS RAISE POPS FURTHER. HIGHS AGAIN IN THE UPPER 80S TO AROUND 90. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... THE PERIOD STARTS OFF WITH THE REGION BEING SQUEEZED BETWEEN A DEEP LAYER ATLANTIC RIDGE CENTERED WELL EAST OF THE AREA AND AN UPPER LEVEL TROUGH MOVING INTO THE OHIO AND TENNESSEE RIVER VALLEYS. THESE TWO FEATURES HELP TO FOCUS SUFFICIENT DEEP LAYER MOISTURE ACROSS THE REGION FOR SUNDAY. THIS MOISTURE...ALONG WITH SOME FORCING FROM THE UPPER TROUGH TO THE NORTHWEST SHOULD RESULT IN SCATTERED CONVECTION BY AFTERNOON. KEPT POPS CONSERVATIVE FOR IN THE MID TO HIGH END CHANCE RANGE. BY LATER SUNDAY AND BEYOND IS WHEN THE GLOBAL MODELS BEGIN TO REALLY DIVERGE IN THE LARGE SCALE PATTERN. THE GFS WEAKENS THE UPPER TROUGH TO THE NORTHWEST AND LEAVES THE AREA LARGELY DOMINATED BY ATLANTIC HIGH PRESSURE THROUGH MID WEEK...WHILE THE ECMWF HOLDS ONTO THE UPPER TROUGH TO THE NORTHWEST LONGER. THESE DIFFERENCES MAY BECOME VERY IMPORTANT SINCE THEY WILL HAVE A LARGE INFLUENCE ON WHERE ERIKA /OR THE REMNANTS OF/ TRACK. THE GFS CONTINUES TO SIGNIFICANTLY WEAKEN THE CIRCULATION ASSOCIATED WITH ERIKA AND MOVES IT ACROSS CUBA AND THE FLORIDA STRAIGHTS MONDAY AND TUESDAY...THEN LOSES IT SOMEWHERE OVER NORTHERN FLORIDA AND OFF THE OUR ATLANTIC COAST BY WEDNESDAY. THE ECMWF IS MUCH STRONGER WITH THE SYSTEM AND HAS A MORE EASTERLY TRACK OVER THE FLORIDA PENINSULA EARLY NEXT WEEK THEN STALLING OFF THE NORTHEAST FLORIDA COAST. THAT BEING SAID...WE WILL CONTINUE TO MONITOR BOTH THE LATEST MODEL TRENDS CONCERNING THE FATE OF ERIKA AS WELL AS OFFICIAL FORECASTS FROM THE NATIONAL HURRICANE CENTER. FOR NOW...GIVEN THE EXTREME UNCERTAINTY IN PATTERN...HAVE KEPT CHANCES POPS FOR MUCH OF THE PERIOD WITH TEMPERATURES AROUND NORMAL. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... VFR. MODELS ARE SHOWING A SIMILAR SIGNAL THAT SCATTERED TSTMS WILL LIKELY IMPACT AREAS AROUND KCHS BY EARLY/MID AFTERNOON. TIMING IS STILL A BIT IN QUESTION...BUT CONFIDENCE IS HIGH ENOUGH ATTM TO INCLUDE A TEMPO GROUP FROM 19-22Z FOR 4SM -TSRA. MAY NEED TO TWEAK THE TIMES A BIT WITH THE 12Z TAF CYCLE. TSTMS PROBABILITIES ARE TOO LOW AT KSAV THIS FAR OUT TO INCLUDE A MENTION FOR THE 06Z TAF CYCLE. EXTENDED AVIATION OUTLOOK...THURSDAY AND FRIDAY...VFR WILL DOMINATE WITH ISOLATED TO SCATTERED MAINLY AFTERNOON CONVECTION WITH BRIEF FLIGHT RESTRICTIONS POSSIBLE. SATURDAY AND SUNDAY...DEEP LAYER MOISTURE INCREASES AS AN UPPER TROUGH BUILDS TO THE NORTHWEST AND CHANNELS MOISTURE NORTHWARD. THIS SHOULD TRANSLATE TO HIGHER CHANCES FOR CONVECTION AND POTENTIAL FOR BRIEF FLIGHT RESTRICTIONS. EARLY TO MID NEXT WEEK...THERE CONTINUES TO BE LARGE DIFFERENCES IN THE MODELS AS TO THE POTENTIAL TRACK AND STRENGTH OF WHAT IS CURRENTLY ERIKA. FOR NOW EXPECT AT LEAST ISOLATED TO SCATTERED CONVECTION MAINLY DURING THE AFTERNOON...BUT WILL CONTINUE TO CLOSELY WATCH LATEST MODEL TRENDS AND OFFICIAL FORECASTS FROM THE NATIONAL HURRICANE CENTER CONCERNING ERIKA. && .MARINE... TODAY...SOUTHWEST WINDS THIS MORNING WILL BACK SOUTH THIS AFTERNOON AS A COLD FRONT APPROACHES THE COAST. LOCAL SEA BREEZE ENHANCEMENTS ARE LIKELY...MAINLY NEAR THE LAND/SEA INTERFACE AND CHARLESTON HARBOR. WINDS WILL HOLD AROUND 10 KT...LOCALLY HIGHER NEAR THE COAST. SEAS WILL AVERAGE 2-3 FT...MAINLY COMPRISED 10-11 SECOND SWELL FROM THE EAST. TONIGHT...A BIT OF A NOCTURNAL SURGE IS EXPECTED ACROSS THE GEORGIA WATERS AS THE COLD FRONT HOLDS NEARLY STATIONARY. WINDS ACROSS THE SOUTH CAROLINA WATERS WILL BE A BIT LIGHTER GIVEN THE ORIENTATION OF THE LOW-LEVEL JET. EXPECT WINDS TO PEAK 15-20 KT GEORGIA WATERS WITH 5-10 KT CHARLESTON COUNTY WATERS WITH 10-15 KT BEAUFORT COUNTY WATERS. SEAS WILL HOLD 2-3 FT...MAINLY COMPRISED OF 10-11 SECOND SWELL FROM THE EAST. THURSDAY THROUGH MONDAY NIGHT...NO HIGHLIGHTS EXPECTED THROUGH EARLY NEXT WEEK. HIGH PRESSURE WILL REMAIN NORTH OF THE WATERS THROUGH SATURDAY WITH EAST- SOUTHEAST WINDS OF 15 KTS OR LESS AND SEAS 3 FEET OR LESS. BY SUNDAY AND MONDAY...HIGH PRESSURE SHIFTS FURTHER EAST OF THE AREA AND WINDS VEER TO SOUTHEAST TO SOUTH...BUT REMAIN 15 KTS OR LESS AND SEAS 3 TO 4 FEET OR LESS. THE BIG QUESTION AND UNCERTAINTY WITH THE LATER PART OF THE FORECAST PERIOD AND INTO MID NEXT WEEK IS THE FATE OF ERIKA. LATEST GLOBAL MODEL GUIDANCE CONTINUES TO DIFFER ON THE STRENGTH AND EVENTUAL PATH. STAY TUNED TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER CONCERNING ERIKA. WATERSPOUTS...ATMOSPHERIC CONDITIONS ARE GENERALLY SUPPORTIVE OF WATERSPOUTS THIS MORNING. THERE ARE HINTS IN THE RAP THAT A CLOUD LINE OR LAND BREEZE CIRCULATION COULD DEVELOP OFF THE GEORGIA AND FAR SOUTHERN SOUTH CAROLINA COAST AROUND SUNRISE...WHICH COULD FOCUS THE WATERSPOUT POTENTIAL. WINDS ARE FORECAST TO BE A TAD TOO HIGH FOR A MORE SIGNIFICANT RISK...BUT THE OVERALL ASSESSMENT POINTS TO A MODERATE RISK FOR WATERSPOUTS. WILL INCLUDE A MENTION IN THE HAZARDOUS WEATHER OUTLOOK. A MARINE WEATHER STATEMENT MAY ALSO BE ISSUED IF THE FORMATION OF THE LAND BREEZE CIRCULATION OCCURS. && .TIDES/COASTAL FLOODING... CONTINUE TO MONITOR THE POTENTIAL FOR MINOR COASTAL FLOODING DURING THE MAJOR HIGH TIDES THURSDAY THROUGH MID NEXT WEEK DUE TO ELEVATED ASTRONOMICAL FROM THE UPCOMING PERIGEAN TIDES. THE LATEST EXTRA- TROPICAL SURGE GUIDANCE ALREADY SHOWING MARGINAL COASTAL FLOODING TIDE LEVELS FOR CHARLESTON THURSDAY THROUGH SATURDAY...AND VERY CLOSE AT FORT PULASKI. THIS IS LIKELY DUE TO EASTERLY LOW LEVEL WINDS THAT HELP INCREASE THE ALREADY HIGH TIDES. HARD TO TELL HOW MUCH INFLUENCE THE LOW LEVEL WINDS WILL HAVE LATER THIS WEEKEND AND INTO EARLY NEXT WEEK AS THERE IS CONSIDERABLE UNCERTAINTY WITH THE TRACK AND INTENSITY OF ERIKA. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ ST/RFM
AREA FORECAST DISCUSSION...CORRECTED
NWS LINCOLN IL
201 PM CDT WED AUG 26 2015 .SHORT TERM...(TONIGHT) ISSUED AT 200 PM CDT WED AUG 26 2015 LARGE STRATOCUMULUS SHIELD THAT HAS PUSHED SOUTHWARD ACROSS THE NORTHEAST QUARTER OF THE STATE WAS FINALLY STARTING TO SHOW SOME CONTRACTION EARLY THIS AFTERNOON. HOWEVER...IT IS FLANKED ON MOST SIDES BY DIURNAL DEVELOPMENT...SO NET RESULT CONTINUES TO BE QUITE A BIT OF CLOUDS ESPECIALLY ACROSS THE EAST HALF OF THE CWA. THE 900 MB PLOT OFF THE RAP MODEL CONTINUES TO DEPICT THE CLOUD SHIELD THE BEST...AND SHOWS SOME CONTRACTION CONTINUING THIS AFTERNOON. MOST OF THE DIURNAL CLOUDS SHOULD FADE WITH SUNSET. HOWEVER...SOME RESIDUAL MOISTURE SHOULD LINGER FROM THE PERSISTENT CLOUDS...AND WILL GO WITH PARTLY CLOUDY SKIES ACROSS THE NORTHEAST CORNER OF THE FORECAST AREA NEAR DANVILLE AND CHAMPAIGN. WITH HIGH PRESSURE OVERHEAD...ENOUGH CLEAR SKIES EXPECTED THAT MOST AREAS SHOULD FALL INTO THE MID 50S OVERNIGHT. HOWEVER...SOME ADJUSTMENTS MAY BE NEEDED ACROSS THE NORTHEAST IF THE CLOUDS DO NOT CLEAR OUT FAST ENOUGH...AS HAS BEEN THE CASE THE LAST COUPLE NIGHTS. && .LONG TERM...(THURSDAY THROUGH WEDNESDAY) ISSUED AT 200 PM CDT WED AUG 26 2015 LATEST MODEL SOLUTIONS IN REASONABLE AGREEMENT FOR ILLINOIS OVER THE REST OF THE WEEK. MODELS DIFFER IN STRENGTH AND MOISTURE AVAILABILITY OF SOUTHERN STREAM WAVE CURRENTLY OVER FOUR CORNERS AREA AND EXPECTED TO RIDE OVER RIDGE INTO ILLINOIS THIS WEEKEND. WATER VAPOR IMAGERY SHOWS WAVE OVER NORTHERN ARIZONA THIS MORNING PUSHING NORTHWARD OVER STRONG ROCKIES RIDGE. MODEL SUITE CONSISTENT ON BRINGING ENERGY UP OVER THE RIDGE AND INTO MIDWEST FRIDAY AND SATURDAY. UNTIL THEN...DRY CONDITIONS AND A WARMING TREND IS EXPECTED AS 850 TEMPS CLIMB 5-10 DEGREES C BETWEEN THIS MORNINGS RAOB AND FRIDAY EVENING. INCREASING HIGH CLOUDS AHEAD OF THE WAVE MAY INHIBIT WARMING A BIT FOR FRIDAY...BUT TEMPS SHOULD STILL MAKE IT INTO THE 80S THROUGHOUT FORECAST AREA BY FRIDAY AFTERNOON. WAVE APPROACHING FOR THE FIRST PART OF THE WEEKEND IS MOVING INTO A RELATIVELY DRY BUT MOISTENING AIRMASS. IN ADDITION...DIGGING OF NORTHERN STREAM ENERGY ALONG THE WEST COAST SHOULD SLOW PROGRESSION OF SYSTEMS AND THEREFORE SLOW THE INCOMING WAVE. CHANCE OF STORMS ARE EXPECTED IN THE NORTHWEST BY LATE AFTERNOON FRIDAY AND ACROSS MUCH OF THE AREA FRIDAY NIGHT AND PARTICULARLY SATURDAY. MAIN MODEL DIFFERENCES BEGIN TO SHOW UP TOWARD THE END OF THE WEEKEND. LATEST AVAILABLE ECMWF RUNS HAVE BEEN CONSISTENT ON BEING STRONG ENOUGH WITH THIS WAVE TO DEVELOP DECENT NVA IN ITS WAKE ON SUNDAY AND SHUNTING MOISTURE EAST OF THE AREA. THIS LEADS TO A RELATIVELY DRY BUT INCREASINGLY HOT FORECAST AS THE LONGWAVE RIDGE AXIS MOVES ACROSS THE AREA. MEANWHILE...THE 06Z AND 12Z GFS TRENDING WEAKER WITH THE WAVE AND FORECAST AN EVOLUTION TO JUST A GENERAL WEAKNESS OVER THE AREA THROUGH EARLY NEXT WEEK. THIS EVOLUTION SUGGESTS AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS AND LOWER TEMPERATURES WITH GENERALLY MORE CLOUD COVER. AM LEANING TOWARD A COMPROMISE WITH A NOD TOWARD THE GFS WHICH SEEMS TO BE SUPPORTED BY THE CMC AND GEFS MEAN. A QUICK LOOK AT 12Z ECMWF ALSO SUGGESTS IT MAY BE SWINGING BACK TOWARD A WEAKER SOLUTION. ANY CONVECTION THAT DEVELOPS THIS WEEKEND INTO NEXT WEEK SHOULD HAVE LIMITED SEVERE POTENTIAL DUE TO LOW SHEAR IN THE RIDGE AND LIMITED INSTABILITY GIVEN THE WARM 500 MB TEMPS CLIMBING ABOVE -10C. BIGGEST THREAT MAY BE LOCALLY HEAVY RAINFALL DUE TO SLOW MOVEMENT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1220 PM CDT WED AUG 26 2015 LARGE MVFR STRATOCUMULUS DECK CONTINUES TO EDGE SOUTHWARD... HAVING CLIPPED KBMI AND IS COMING FAIRLY CLOSE TO KCMI AT MIDDAY. LATEST RAP GUIDANCE DOES NOT SHOW A LOT MORE FURTHER PROGRESS. HAVE MAINTAINED THE MVFR CONDITIONS AT KBMI AND INCLUDED A TEMPO MVFR CEILING AT KCMI FOR THE NEXT FEW HOURS. TAF SITES FURTHER WEST MAINLY BEING AFFECTED BY DIURNAL CUMULUS CLOSER TO 4000 FEET...AND THIS SHOULD FADE WITH SUNSET. VFR CONDITIONS EXPECTED OVERNIGHT...WITH LIGHT WINDS GRADUALLY TRANSITIONING MORE TOWARD THE SOUTHEAST AS AN AREA OF HIGH PRESSURE PASSES. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GEELHART LONG TERM...BARKER AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1220 PM CDT WED AUG 26 2015 .UPDATE... ISSUED AT 945 AM CDT WED AUG 26 2015 MAIN CONCERN IS WITH THE LOWER CLOUD DECK NUDGING SOUTHWARD. LATEST VISIBLE SATELLITE IMAGERY SHOWS THIS CLOSE TO MOVING INTO BLOOMINGTON...EXTENDING NORTHWARD THROUGH ROCKFORD AND THEN EASTWARD. HRRR CLOUD GUIDANCE TRIES TO BREAK THIS UP OVER THE NEXT COUPLE HOURS...BUT NOT REALLY SEEING ANY EVIDENCE OF THIS YET...WITH THE CLOUD DECK RATHER SOLID UP INTO CENTRAL WISCONSIN. RAP 900 MB HUMIDITY PLOT SHOWS THIS BETTER...AND STARTS MORE OF A BREAKUP AFTER NOON. TIMING OF THE BREAKUP WILL IMPACT FORECAST HIGHS...WHICH ARE IN THE MID 70S IN THAT AREA. DID SOME ADJUSTMENTS OF THE CLOUD TRENDS ACROSS THE EASTERN CWA...BUT NO CHANGES WERE NEEDED TO THE WORDED FORECASTS AT THIS TIME. && .SHORT TERM...(TODAY) ISSUED AT 324 AM CDT WED AUG 26 2015 DEEP UPPER LOW NORTH OF LAKE ERIE EARLY THIS MORNING CONTINUES TO SLOWLY EDGE AWAY FROM THE MIDWEST. HOWEVER, SEVERAL WEAK SHORTWAVES CONTINUE TO ROTATE SOUTHWARD AROUND THE WESTERN PERIPHERY OF THE UPPER LOW ACROSS THE LOWER GREAT LAKES BRINGING CLOUD COVER MUCH FURTHER INTO OUR FORECAST AREA THAN WHAT GUIDANCE SUGGESTED. THAT WILL BE THE MAIN FORECAST CONCERN TODAY, AMOUNT OF CLOUD COVER OVER CENTRAL IL AND ITS AFFECT ON TEMPERATURES. RAP FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS SHOWING QUITE A BIT OF MOISTURE AT OR JUST BELOW 850 MB INTO EARLY THIS AFTERNOON, ESPECIALLY OVER THE EASTERN HALF OF THE FORECAST AREA. WILL HIT THE CLOUD COVER A BIT HEAVIER ACROSS THE EAST TODAY WITH TEMPS CUT BACK A FEW DEGREES AS A RESULT, MAINLY IN THE MID 70S, WHILE FURTHER WEST, A BIT MORE SUN SHOULD ALLOW AFTERNOON TEMPERATURES TO RISE INTO THE UPPER 70S. SOUNDINGS INDICATE SOME GUSTS UP TO 20 MPH POSSIBLE AGAIN FROM THE NORTHWEST LATER THIS MORNING INTO THE AFTERNOON HOURS, ESPECIALLY ACROSS THE WEST WHERE THERE WILL BE DEEPER MIXING OCCURRING. .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 324 AM CDT WED AUG 26 2015 SLIGHTLY COOLER THAN CLIMATOLOGICAL NORMS THROUGH THE END OF THE WEEK, ALBEIT IN A SLIGHT WARMING TREND. FORECAST ISSUE IN THE LONGER TERM REMAINS THE SYSTEM FOR THE BEGINNING OF THE WEEKEND. A SHORT WAVE DIVES INTO THE MIDWEST RIPPLING THROUGH THE PREDOMINANTLY NWRLY FLOW. MODELS HAVE BEEN INCONSISTENT WITH THE TIMING AND THE SPEED OF THE SYSTEM ITSELF WITH ITS OWN FORWARD MOTION. WAVE REACHES THE MIDWEST AND SLOWS CONSIDERABLY. EITHER WAY, SOME CONSENSUS APPEARS AS TO ONSET OF PRECIP IN CENTRAL ILLINOIS AFTER 00Z SATURDAY BTWN THE GFS/ECMWF/NAM. HOWEVER, AT THIS POINT, THE PRECIP STARTS TO BECOME LESS IN COVERAGE. EXPECTED THROUGH THE OVERNIGHT FRI NIGHT PERHAPS WITH THE LOSS OF A DIURNAL COMPONENT, BUT LESS EXPECTED DURING THE DAY ON TUESDAY. THAT BEING SAID, THE SOUNDINGS ARE NOT REPRESENTATIVE FOR RAIN, DRYING OUT CONSIDERABLY WHILE THE MODELS ARE GENERATING QPF. A RATHER DRY AIRMASS FOR DAYS...THE MODELS SEEM TO BE OVERDOING THE BOUNDARY LAYER AVAILABLE MOISTURE. OVERBLOWN RH IN THE LOW LEVELS IN THE NAM IS EXPECTED AND SO FAR, IT IS TRUE TO FORM IN PRODUCING SIGNIFICANTLY MORE QPF. THE TREND, THOUGH, IS MORE TO A POTENTIAL SHOWERY SITUATION. HAVE EASED BACK POPS WHERE COLLABORATIVELY POSSIBLE, AND SWITCHED THE WORDING TO COVERAGE INSTEAD OF PROBABILITY. BEYOND THE POPS ON THE WEEKEND, THE FLOW SWITCHES TO A LESS AMPLIFIED PATTERN. THE WEAK SOUTHWESTERLY FLOW ALLOWS THE HEAT OVER THE DESERT SW TO ESCAPE OUT FROM UNDER THE PERSISTENT RIDGE AND BRING A WARMING TREND FOR THE FIRST COUPLE DAYS OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1220 PM CDT WED AUG 26 2015 LARGE MVFR STRATOCUMULUS DECK CONTINUES TO EDGE SOUTHWARD... HAVING CLIPPED KBMI AND IS COMING FAIRLY CLOSE TO KCMI AT MIDDAY. LATEST RAP GUIDANCE DOES NOT SHOW A LOT MORE FURTHER PROGRESS. HAVE MAINTAINED THE MVFR CONDITIONS AT KBMI AND INCLUDED A TEMPO MVFR CEILING AT KCMI FOR THE NEXT FEW HOURS. TAF SITES FURTHER WEST MAINLY BEING AFFECTED BY DIURNAL CUMULUS CLOSER TO 4000 FEET...AND THIS SHOULD FADE WITH SUNSET. VFR CONDITIONS EXPECTED OVERNIGHT...WITH LIGHT WINDS GRADUALLY TRANSITIONING MORE TOWARD THE SOUTHEAST AS AN AREA OF HIGH PRESSURE PASSES. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEELHART SHORT TERM...SMITH LONG TERM...HJS AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS LINCOLN IL
947 AM CDT WED AUG 26 2015 .UPDATE... ISSUED AT 945 AM CDT WED AUG 26 2015 MAIN CONCERN IS WITH THE LOWER CLOUD DECK NUDGING SOUTHWARD. LATEST VISIBLE SATELLITE IMAGERY SHOWS THIS CLOSE TO MOVING INTO BLOOMINGTON...EXTENDING NORTHWARD THROUGH ROCKFORD AND THEN EASTWARD. HRRR CLOUD GUIDANCE TRIES TO BREAK THIS UP OVER THE NEXT COUPLE HOURS...BUT NOT REALLY SEEING ANY EVIDENCE OF THIS YET...WITH THE CLOUD DECK RATHER SOLID UP INTO CENTRAL WISCONSIN. RAP 900 MB HUMIDITY PLOT SHOWS THIS BETTER...AND STARTS MORE OF A BREAKUP AFTER NOON. TIMING OF THE BREAKUP WILL IMPACT FORECAST HIGHS...WHICH ARE IN THE MID 70S IN THAT AREA. DID SOME ADJUSTMENTS OF THE CLOUD TRENDS ACROSS THE EASTERN CWA...BUT NO CHANGES WERE NEEDED TO THE WORDED FORECASTS AT THIS TIME. && .SHORT TERM...(TODAY) ISSUED AT 324 AM CDT WED AUG 26 2015 DEEP UPPER LOW NORTH OF LAKE ERIE EARLY THIS MORNING CONTINUES TO SLOWLY EDGE AWAY FROM THE MIDWEST. HOWEVER, SEVERAL WEAK SHORTWAVES CONTINUE TO ROTATE SOUTHWARD AROUND THE WESTERN PERIPHERY OF THE UPPER LOW ACROSS THE LOWER GREAT LAKES BRINGING CLOUD COVER MUCH FURTHER INTO OUR FORECAST AREA THAN WHAT GUIDANCE SUGGESTED. THAT WILL BE THE MAIN FORECAST CONCERN TODAY, AMOUNT OF CLOUD COVER OVER CENTRAL IL AND ITS AFFECT ON TEMPERATURES. RAP FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS SHOWING QUITE A BIT OF MOISTURE AT OR JUST BELOW 850 MB INTO EARLY THIS AFTERNOON, ESPECIALLY OVER THE EASTERN HALF OF THE FORECAST AREA. WILL HIT THE CLOUD COVER A BIT HEAVIER ACROSS THE EAST TODAY WITH TEMPS CUT BACK A FEW DEGREES AS A RESULT, MAINLY IN THE MID 70S, WHILE FURTHER WEST, A BIT MORE SUN SHOULD ALLOW AFTERNOON TEMPERATURES TO RISE INTO THE UPPER 70S. SOUNDINGS INDICATE SOME GUSTS UP TO 20 MPH POSSIBLE AGAIN FROM THE NORTHWEST LATER THIS MORNING INTO THE AFTERNOON HOURS, ESPECIALLY ACROSS THE WEST WHERE THERE WILL BE DEEPER MIXING OCCURRING. .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 324 AM CDT WED AUG 26 2015 SLIGHTLY COOLER THAN CLIMATOLOGICAL NORMS THROUGH THE END OF THE WEEK, ALBEIT IN A SLIGHT WARMING TREND. FORECAST ISSUE IN THE LONGER TERM REMAINS THE SYSTEM FOR THE BEGINNING OF THE WEEKEND. A SHORT WAVE DIVES INTO THE MIDWEST RIPPLING THROUGH THE PREDOMINANTLY NWRLY FLOW. MODELS HAVE BEEN INCONSISTENT WITH THE TIMING AND THE SPEED OF THE SYSTEM ITSELF WITH ITS OWN FORWARD MOTION. WAVE REACHES THE MIDWEST AND SLOWS CONSIDERABLY. EITHER WAY, SOME CONSENSUS APPEARS AS TO ONSET OF PRECIP IN CENTRAL ILLINOIS AFTER 00Z SATURDAY BTWN THE GFS/ECMWF/NAM. HOWEVER, AT THIS POINT, THE PRECIP STARTS TO BECOME LESS IN COVERAGE. EXPECTED THROUGH THE OVERNIGHT FRI NIGHT PERHAPS WITH THE LOSS OF A DIURNAL COMPONENT, BUT LESS EXPECTED DURING THE DAY ON TUESDAY. THAT BEING SAID, THE SOUNDINGS ARE NOT REPRESENTATIVE FOR RAIN, DRYING OUT CONSIDERABLY WHILE THE MODELS ARE GENERATING QPF. A RATHER DRY AIRMASS FOR DAYS...THE MODELS SEEM TO BE OVERDOING THE BOUNDARY LAYER AVAILABLE MOISTURE. OVERBLOWN RH IN THE LOW LEVELS IN THE NAM IS EXPECTED AND SO FAR, IT IS TRUE TO FORM IN PRODUCING SIGNIFICANTLY MORE QPF. THE TREND, THOUGH, IS MORE TO A POTENTIAL SHOWERY SITUATION. HAVE EASED BACK POPS WHERE COLLABORATIVELY POSSIBLE, AND SWITCHED THE WORDING TO COVERAGE INSTEAD OF PROBABILITY. BEYOND THE POPS ON THE WEEKEND, THE FLOW SWITCHES TO A LESS AMPLIFIED PATTERN. THE WEAK SOUTHWESTERLY FLOW ALLOWS THE HEAT OVER THE DESERT SW TO ESCAPE OUT FROM UNDER THE PERSISTENT RIDGE AND BRING A WARMING TREND FOR THE FIRST COUPLE DAYS OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 625 AM CDT WED AUG 26 2015 MAIN CHALLENGE THIS PERIOD WILL BE WITH EXTENT OF CLOUD COVER MAINLY ACROSS THE EASTERN TAF SITES. A BAND OF LOW VFR WITH A FEW AREAS OF MVFR CIGS WAS LOCATED JUST TO OUR NORTH THIS MORNING WITH A SOUTHWARD DRIFT IN THE CLOUD BAND. WILL CARRY CIGS IN THE 3000-4000 FOOT RANGE FROM BMI SOUTH TOWARDS DEC OVER TO CMI THIS MORNING WHICH SHOULD CONTINUE INTO THE MID AFTERNOON HOURS BEFORE COVERAGE DECREASES. SURFACE WINDS WILL BE OUT OF THE NORTH AT 10 TO 15 KTS...WITH A FEW GUSTS POSSIBLE THIS AFTERNOON AT SPI WHERE WE SHOULD SEE SOME BETTER MIXING DUE TO MORE SUNSHINE COMPARED TO THE TAF SITES FURTHER TO THE EAST. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEELHART SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
626 AM CDT WED AUG 26 2015 .SHORT TERM...(TODAY) ISSUED AT 324 AM CDT WED AUG 26 2015 DEEP UPPER LOW NORTH OF LAKE ERIE EARLY THIS MORNING CONTINUES TO SLOWLY EDGE AWAY FROM THE MIDWEST. HOWEVER, SEVERAL WEAK SHORTWAVES CONTINUE TO ROTATE SOUTHWARD AROUND THE WESTERN PERIPHERY OF THE UPPER LOW ACROSS THE LOWER GREAT LAKES BRINGING CLOUD COVER MUCH FURTHER INTO OUR FORECAST AREA THAN WHAT GUIDANCE SUGGESTED. THAT WILL BE THE MAIN FORECAST CONCERN TODAY, AMOUNT OF CLOUD COVER OVER CENTRAL IL AND ITS AFFECT ON TEMPERATURES. RAP FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS SHOWING QUITE A BIT OF MOISTURE AT OR JUST BELOW 850 MB INTO EARLY THIS AFTERNOON, ESPECIALLY OVER THE EASTERN HALF OF THE FORECAST AREA. WILL HIT THE CLOUD COVER A BIT HEAVIER ACROSS THE EAST TODAY WITH TEMPS CUT BACK A FEW DEGREES AS A RESULT, MAINLY IN THE MID 70S, WHILE FURTHER WEST, A BIT MORE SUN SHOULD ALLOW AFTERNOON TEMPERATURES TO RISE INTO THE UPPER 70S. SOUNDINGS INDICATE SOME GUSTS UP TO 20 MPH POSSIBLE AGAIN FROM THE NORTHWEST LATER THIS MORNING INTO THE AFTERNOON HOURS, ESPECIALLY ACROSS THE WEST WHERE THERE WILL BE DEEPER MIXING OCCURRING. .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 324 AM CDT WED AUG 26 2015 SLIGHTLY COOLER THAN CLIMATOLOGICAL NORMS THROUGH THE END OF THE WEEK, ALBEIT IN A SLIGHT WARMING TREND. FORECAST ISSUE IN THE LONGER TERM REMAINS THE SYSTEM FOR THE BEGINNING OF THE WEEKEND. A SHORT WAVE DIVES INTO THE MIDWEST RIPPLING THROUGH THE PREDOMINANTLY NWRLY FLOW. MODELS HAVE BEEN INCONSISTENT WITH THE TIMING AND THE SPEED OF THE SYSTEM ITSELF WITH ITS OWN FORWARD MOTION. WAVE REACHES THE MIDWEST AND SLOWS CONSIDERABLY. EITHER WAY, SOME CONSENSUS APPEARS AS TO ONSET OF PRECIP IN CENTRAL ILLINOIS AFTER 00Z SATURDAY BTWN THE GFS/ECMWF/NAM. HOWEVER, AT THIS POINT, THE PRECIP STARTS TO BECOME LESS IN COVERAGE. EXPECTED THROUGH THE OVERNIGHT FRI NIGHT PERHAPS WITH THE LOSS OF A DIURNAL COMPONENT, BUT LESS EXPECTED DURING THE DAY ON TUESDAY. THAT BEING SAID, THE SOUNDINGS ARE NOT REPRESENTATIVE FOR RAIN, DRYING OUT CONSIDERABLY WHILE THE MODELS ARE GENERATING QPF. A RATHER DRY AIRMASS FOR DAYS...THE MODELS SEEM TO BE OVERDOING THE BOUNDARY LAYER AVAILABLE MOISTURE. OVERBLOWN RH IN THE LOW LEVELS IN THE NAM IS EXPECTED AND SO FAR, IT IS TRUE TO FORM IN PRODUCING SIGNIFICANTLY MORE QPF. THE TREND, THOUGH, IS MORE TO A POTENTIAL SHOWERY SITUATION. HAVE EASED BACK POPS WHERE COLLABORATIVELY POSSIBLE, AND SWITCHED THE WORDING TO COVERAGE INSTEAD OF PROBABILITY. BEYOND THE POPS ON THE WEEKEND, THE FLOW SWITCHES TO A LESS AMPLIFIED PATTERN. THE WEAK SOUTHWESTERLY FLOW ALLOWS THE HEAT OVER THE DESERT SW TO ESCAPE OUT FROM UNDER THE PERSISTENT RIDGE AND BRING A WARMING TREND FOR THE FIRST COUPLE DAYS OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 625 AM CDT WED AUG 26 2015 MAIN CHALLENGE THIS PERIOD WILL BE WITH EXTENT OF CLOUD COVER MAINLY ACROSS THE EASTERN TAF SITES. A BAND OF LOW VFR WITH A FEW AREAS OF MVFR CIGS WAS LOCATED JUST TO OUR NORTH THIS MORNING WITH A SOUTHWARD DRIFT IN THE CLOUD BAND. WILL CARRY CIGS IN THE 3000-4000 FOOT RANGE FROM BMI SOUTH TOWARDS DEC OVER TO CMI THIS MORNING WHICH SHOULD CONTINUE INTO THE MID AFTERNOON HOURS BEFORE COVERAGE DECREASES. SURFACE WINDS WILL BE OUT OF THE NORTH AT 10 TO 15 KTS...WITH A FEW GUSTS POSSIBLE THIS AFTERNOON AT SPI WHERE WE SHOULD SEE SOME BETTER MIXING DUE TO MORE SUNSHINE COMPARED TO THE TAF SITES FURTHER TO THE EAST. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
325 AM CDT WED AUG 26 2015 .SHORT TERM...(TODAY) ISSUED AT 324 AM CDT WED AUG 26 2015 DEEP UPPER LOW NORTH OF LAKE ERIE EARLY THIS MORNING CONTINUES TO SLOWLY EDGE AWAY FROM THE MIDWEST. HOWEVER, SEVERAL WEAK SHORTWAVES CONTINUE TO ROTATE SOUTHWARD AROUND THE WESTERN PERIPHERY OF THE UPPER LOW ACROSS THE LOWER GREAT LAKES BRINGING CLOUD COVER MUCH FURTHER INTO OUR FORECAST AREA THAN WHAT GUIDANCE SUGGESTED. THAT WILL BE THE MAIN FORECAST CONCERN TODAY, AMOUNT OF CLOUD COVER OVER CENTRAL IL AND ITS AFFECT ON TEMPERATURES. RAP FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS SHOWING QUITE A BIT OF MOISTURE AT OR JUST BELOW 850 MB INTO EARLY THIS AFTERNOON, ESPECIALLY OVER THE EASTERN HALF OF THE FORECAST AREA. WILL HIT THE CLOUD COVER A BIT HEAVIER ACROSS THE EAST TODAY WITH TEMPS CUT BACK A FEW DEGREES AS A RESULT, MAINLY IN THE MID 70S, WHILE FURTHER WEST, A BIT MORE SUN SHOULD ALLOW AFTERNOON TEMPERATURES TO RISE INTO THE UPPER 70S. SOUNDINGS INDICATE SOME GUSTS UP TO 20 MPH POSSIBLE AGAIN FROM THE NORTHWEST LATER THIS MORNING INTO THE AFTERNOON HOURS, ESPECIALLY ACROSS THE WEST WHERE THERE WILL BE DEEPER MIXING OCCURRING. && .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 324 AM CDT WED AUG 26 2015 SLIGHTLY COOLER THAN CLIMATOLOGICAL NORMS THROUGH THE END OF THE WEEK, ALBEIT IN A SLIGHT WARMING TREND. FORECAST ISSUE IN THE LONGER TERM REMAINS THE SYSTEM FOR THE BEGINNING OF THE WEEKEND. A SHORT WAVE DIVES INTO THE MIDWEST RIPPLING THROUGH THE PREDOMINANTLY NWRLY FLOW. MODELS HAVE BEEN INCONSISTENT WITH THE TIMING AND THE SPEED OF THE SYSTEM ITSELF WITH ITS OWN FORWARD MOTION. WAVE REACHES THE MIDWEST AND SLOWS CONSIDERABLY. EITHER WAY, SOME CONSENSUS APPEARS AS TO ONSET OF PRECIP IN CENTRAL ILLINOIS AFTER 00Z SATURDAY BTWN THE GFS/ECMWF/NAM. HOWEVER, AT THIS POINT, THE PRECIP STARTS TO BECOME LESS IN COVERAGE. EXPECTED THROUGH THE OVERNIGHT FRI NIGHT PERHAPS WITH THE LOSS OF A DIURNAL COMPONENT, BUT LESS EXPECTED DURING THE DAY ON TUESDAY. THAT BEING SAID, THE SOUNDINGS ARE NOT REPRESENTATIVE FOR RAIN, DRYING OUT CONSIDERABLY WHILE THE MODELS ARE GENERATING QPF. A RATHER DRY AIRMASS FOR DAYS...THE MODELS SEEM TO BE OVERDOING THE BOUNDARY LAYER AVAILABLE MOISTURE. OVERBLOWN RH IN THE LOW LEVELS IN THE NAM IS EXPECTED AND SO FAR, IT IS TRUE TO FORM IN PRODUCING SIGNIFICANTLY MORE QPF. THE TREND, THOUGH, IS MORE TO A POTENTIAL SHOWERY SITUATION. HAVE EASED BACK POPS WHERE COLLABORATIVELY POSSIBLE, AND SWITCHED THE WORDING TO COVERAGE INSTEAD OF PROBABILITY. BEYOND THE POPS ON THE WEEKEND, THE FLOW SWITCHES TO A LESS AMPLIFIED PATTERN. THE WEAK SOUTHWESTERLY FLOW ALLOWS THE HEAT OVER THE DESERT SW TO ESCAPE OUT FROM UNDER THE PERSISTENT RIDGE AND BRING A WARMING TREND FOR THE FIRST COUPLE DAYS OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1142 PM CDT TUE AUG 25 2015 QUIET/VFR AVIATION WEATHER CONDITIONS EXPECTED ACROSS THE CENTRAL ILLINOIS TERMINALS THROUGH THE 06Z TAF VALID TIME. A RIDGE OF HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA DURING THE PERIOD HELPING WINDS TO REMAIN LIGHT. CLOUD COVER SHOULD BE MINIMAL OVERALL, BUT A PERIOD OF BROKEN VFR CIGS IS POSSIBLE FOR A FEW MORE HOURS KPIA, KBMI, KDEC & KCMI AS AN UPPER LEVEL DISTURBANCE DIVES SOUTHEAST FROM THE GREAT LAKES. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...BAK
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
614 PM CDT THU AUG 27 2015 ...Updated for Aviation... .SHORT TERM...(THIS EVENING THROUGH Friday) ISSUED AT 117 PM CDT THU AUG 27 2015 Models remain in good agreement with an upper level trough crossing the Central High Plains overnight as a surface boundary/weak cold front crosses southwestern Kansas. Water vapor loop earlier this morning indicated an upper level disturbance, located over southern Colorado at 12z Thursday. Dprog/dt along with the RAP and NAM suggesting that this disturbance will precede the main upper trough and will be crossing southwest Kansas between 18z Thursday and 00z Friday. Based on the timing of the southern Colorado upper wave along with 700mb moisture, 700mb frontogenesis, and afternoon mid level instability ahead of this wave late day will be leaning towards the HRRR,RAP,ARW, and NMM with the better chances for scattered thunderstorms developing along and east of a Dighton to Hugoton line. the main hazards from these storms still appear to be hail quarter size and smaller along with wind gusts of near 60 mph based on the latest RAP 0-6km shear and CAPE values late today and early this evening. Periods of moderate to heavy rainfall will also be possible, especially east of highway 283. These thunderstorms are expected to move east overnight as another area of scattered thunderstorms develop further west near the weak cold front/surface boundary as it and the main upper trough crosses western Kansas between 03z and 12z Friday. Severe weather is not anticipated with these storms, however moderate rainfall and lightning still will be likely. A few lingering thunderstorms will be possible across south central Kansas early Friday morning, however as the upper level trough moves east towards the mid Mississippi valley these storms will quickly end and skies will begin to clear from west to east. As the weak cold front continues to move south across Oklahoma during the day the 900mb to 850mb temperatures will cool. 850mb mix down temperatures at 00z Saturday continue to supports highs mainly in the 85 to 90 degree range. .LONG TERM...(Friday NIGHT THROUGH Thursday) ISSUED AT 240 PM CDT THU AUG 27 2015 High pressure at the surface will build across western Kansas Friday night so winds will decrease to less than 10 knots after sunset. Given these winds and clear/mostly clear conditions will trend towards undercutting guidance for lows. Will favor temperatures falling back into the mainly the upper 50s to lower 60s. From Saturday through the beginning of next week an upper level ridge will build and shift eastward into the Central and Northern Plains. This trend continues to support the previous forecast with a gradual warming trend through early next week. Highs will be rebounding from the upper 80s to around 90 on Saturday to at least the low to mid 90s on Monday and Tuesday. Towards mid week a southwesterly flow will develop across the Central High Plains. The GFS and ECMWF also suggest some tropical moisture will try to return to Colorado and portions of western Kansas. This may limit how warm temperatures will get around mid week. There will also be a slightly better chance for afternoon and evening thunderstorms along a surface boundary which is expected to be located near the Colorado border should any subtle upper wave be embedded in the southwesterly flow. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Friday EVENING) ISSUED AT 609 PM CDT THU AUG 27 2015 VFR conditions are expected. A shortwave trough will move through western KS tonight with strong storms staying mainly east and south of the TAF sites. South winds of 15-25kt will decrease by 03z, then switch to the north or become light and variable mainly after 06Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 66 88 60 89 / 40 10 0 0 GCK 64 88 59 89 / 30 10 0 0 EHA 64 88 59 89 / 30 10 10 0 LBL 66 89 60 90 / 40 10 0 0 HYS 65 87 59 89 / 50 10 0 0 P28 70 91 63 90 / 20 20 10 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS GOODLAND KS
448 PM MDT WED AUG 26 2015 .UPDATE... ISSUED AT 443 PM MDT WED AUG 26 2015 INSERTED SLIGHT CHANCE POPS ALONG AND EAST OF AN IMPERIAL NE TO HILL CITY KS LINE FOR THE LATE AFTERNOON AND EARLY EVENING HOURS. ISOLATED STORM POPPED UP ALONG RETREATING FRONTAL BOUNDARY NEAR KHLC WHERE DEW POINTS REMAIN IN THE UPPER 50S TO LOWER 60S. STORMS WILL DISSIPATE WITH LOSS OF SURFACE HEATING AFTER SUNSET. DEEP LAYER SHEAR AND INSTABILITY SUPPORT AN ISOLATED SEVERE THREAT FOR HAIL...BUT COVERAGE WILL BE QUITE LIMITED DUE TO LACK OF UPPER FORCING. ALSO INCREASED CLOUDINESS WITH COPIOUS MID/HIGH LEVEL CLOUDS OVERSPREADING THE AREA FROM THE WEST. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 110 PM MDT WED AUG 26 2015 WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS THE PLAINS WITH 596 DM CENTER AXIS EXTENDING NORTH OVER OUR CWA. SHORTWAVE TROUGH IS CURRENTLY ROTATING AROUND WESTERN EDGE OF RIDGE WITH MOISTURE PLUME EXTENDING ACROSS THE CENTRAL ROCKIES AHEAD OF THIS FEATURE. AT THE SURFACE LO PRESSURE EXTENDS FROM EASTERN MONTANA ACROSS EASTERN COLORADO AND OVER OUR CWA. A WEAK STATIONARY FRONT IS CURRENTLY IN PLACE FROM SW NEBRASKA AND ACROSS CENTRAL KANSAS (NEAR HLC). THIS AFTERNOON-TONIGHT...VERY DRY AIR MASS...STRONG CAP...AND LIMITED LARGE SCALE FORCING WILL CONTINUE TO LIMIT CONVECTIVE POTENTIAL. CAP MAY BEGIN TO WEAKEN ALONG STALLED FRONT IN OUR EASTERN CWA LATER THIS AFTERNOON...HOWEVER AT THIS POINT CONFIDENCE IS TOO LOW TO INCLUDE A MENTION OF SHOWERS/THUNDERSTORMS. AS WAS EXPECTED HOT TEMPERATURES AND FAVORABLE MIXING HAVE RESULTED IN VERY LOW RH VALUES THIS AFTERNOON ACROSS THE WESTERN HALF OF OF OUR FORECAST AREA...WITH SOME LOCATIONS GUSTING TO NEAR RFW CRITERIA. WITH FUELS STILL NOT CONSIDERED FAVORABLE FOR RAPID FIRE SPREAD I HAVE HELD BACK ON RFW ISSUANCE. THURSDAY...UPPER LEVEL TROUGH WILL ROTATE AROUND THE NORTH SIDE OF THE RIDGE AND DEEPEN AS IT TRACKS ACROSS THE NORTHERN PLAINS. LARGE SCALE FORCING WILL OVERSPREAD OUR CWA ON THE SOUTHERN EXTENT OF THIS FEATURE...WITH DRY AIR MASS INITIALLY LIMITING CONVECTIVE COVERAGE UNTIL LATER THURSDAY AFTERNOON. RETURN FLOW AHEAD OF APPROACHING FRONT MAY LEAD TO INCREASED TDS AND HIGHER CAPE VALUES ACROSS OUR EASTERN CWA. GFS AND NAM BOTH SHOWING VERY DIFFERENT PICTURE REGARDING MOISTURE/CAPE PROFILES WITH NAM SHOWING BETTER MOISTURE RETURN AND HIGHER CAPE BY 00Z. EFFECTIVE SHEER VALUES 35KT OR HIGHER WILL BE POSSIBLE...SO IF THE MORE AGGRESSIVE GUIDANCE WAS TO VERIFY WE COULD SEE A MORE ORGANIZED SEVERE THREAT ROUGHLY ALONG/EAST OF HIGHWAY 83. REGARDLESS OF SEVERE THREAT...GFS/NAM BOTH SHOW THE BEST PRECIP SIGNAL IN OUR EAST/SOUTHEAST ALONG PRE FRONTAL TROUGH...AND I RAISED POPS ACCORDINGLY. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 225 PM MDT WED AUG 26 2015 A RIDGE WILL MOVE INTO THE ROCKIES THROUGH FRIDAY NIGHT AND THEN START MOVING INTO THE PLAINS SATURDAY. A SURFACE TROUGH WILL MOVE EAST ACROSS NORTHWEST KANSAS THURSDAY NIGHT FOLLOWED BY HIGH PRESSURE WHICH SHOULD LINGER OVER THE PLAINS THROUGH SATURDAY. A SHORTWAVE MOVING OVER THE TOP OF THE RIDGE WILL BE EXITING THE FA THURSDAY EVENING. PLAN TO CONTINUE CHANCE/SLIGHT CHANCE POPS FOR THE EVENING. DYNAMICS SHOULD BE EXITING THE FA AROUND 06Z FRIDAY. SUBSIDENCE BUILDS INTO THE FA FRIDAY AND CONTINUES THROUGH SATURDAY. POPS WILL BE NIL FOR THOSE PERIODS. MIN TEMPERATURES SHOULD RANGE FROM THE UPPER 50S IN EASTERN COLORADO TO THE LOWER 60S ELSEWHERE. MAX TEMPERATURES SHOULD REACH THE MID AND UPPER 80S. IN THE EXTENDED...(SATURDAY NIGHT THROUGH WEDNESDAY)... THE UPPER RIDGE WILL REMAIN OVER THE PLAINS THROUGH SUNDAY AND THEN MOVE EAST OF THE PLAINS MONDAY. THE FORECAST WILL REMAIN DRY THROUGH MONDAY DUE TO THE LACK OF SUFFICIENT MOISTURE AND FORCING. HOWEVER BY MONDAY EVENING MONSOONAL MOISTURE WILL BEGIN TO IMPACT THE AREA WITH A SLIGHT CHANCE OF THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH WEDNESDAY. MIN TEMPERATURES SHOULD COOL TO THE LOWER AND MID 60S. MAX TEMPERATURES SHOULD REACH THE LOWER 90S EACH DAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1150 AM MDT WED AUG 26 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. GUSTY WINDS SHOULD DEVELOP AT BOTH TERMINALS THIS AFTERNOON WITH INCREASED MIXING. AS WINDS DECREASE THIS EVENING A DEVELOPING LOW LEVEL JET WILL LEAD TO LOW LEVEL WIND SHEER 35-40 KT AT BOTH TERMINALS (FIRST AT KGLD AND THEN AT KMCK). AN APPROACHING UPPER LEVEL SYSTEM MAY BRING SHOWER OR THUNDERSTORMS TO EITHER TERMINAL BY MIDDAY THURSDAY...HOWEVER CONFIDENCE IS TOO LOW IN COVERAGE TO INCLUDE MENTION IN TAFS DURING THIS UPDATE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...024 SHORT TERM...DR LONG TERM...FS AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 PM MDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 110 PM MDT WED AUG 26 2015 WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS THE PLAINS WITH 596 DM CENTER AXIS EXTENDING NORTH OVER OUR CWA. SHORTWAVE TROUGH IS CURRENTLY ROTATING AROUND WESTERN EDGE OF RIDGE WITH MOISTURE PLUME EXTENDING ACROSS THE CENTRAL ROCKIES AHEAD OF THIS FEATURE. AT THE SURFACE LO PRESSURE EXTENDS FROM EASTERN MONTANA ACROSS EASTERN COLORADO AND OVER OUR CWA. A WEAK STATIONARY FRONT IS CURRENTLY IN PLACE FROM SW NEBRASKA AND ACROSS CENTRAL KANSAS (NEAR HLC). THIS AFTERNOON-TONIGHT...VERY DRY AIR MASS...STRONG CAP...AND LIMITED LARGE SCALE FORCING WILL CONTINUE TO LIMIT CONVECTIVE POTENTIAL. CAP MAY BEGIN TO WEAKEN ALONG STALLED FRONT IN OUR EASTERN CWA LATER THIS AFTERNOON...HOWEVER AT THIS POINT CONFIDENCE IS TOO LOW TO INCLUDE A MENTION OF SHOWERS/THUNDERSTORMS. AS WAS EXPECTED HOT TEMPERATURES AND FAVORABLE MIXING HAVE RESULTED IN VERY LOW RH VALUES THIS AFTERNOON ACROSS THE WESTERN HALF OF OF OUR FORECAST AREA...WITH SOME LOCATIONS GUSTING TO NEAR RFW CRITERIA. WITH FUELS STILL NOT CONSIDERED FAVORABLE FOR RAPID FIRE SPREAD I HAVE HELD BACK ON RFW ISSUANCE. THURSDAY...UPPER LEVEL TROUGH WILL ROTATE AROUND THE NORTH SIDE OF THE RIDGE AND DEEPEN AS IT TRACKS ACROSS THE NORTHERN PLAINS. LARGE SCALE FORCING WILL OVERSPREAD OUR CWA ON THE SOUTHERN EXTENT OF THIS FEATURE...WITH DRY AIR MASS INITIALLY LIMITING CONVECTIVE COVERAGE UNTIL LATER THURSDAY AFTERNOON. RETURN FLOW AHEAD OF APPROACHING FRONT MAY LEAD TO INCREASED TDS AND HIGHER CAPE VALUES ACROSS OUR EASTERN CWA. GFS AND NAM BOTH SHOWING VERY DIFFERENT PICTURE REGARDING MOISTURE/CAPE PROFILES WITH NAM SHOWING BETTER MOISTURE RETURN AND HIGHER CAPE BY 00Z. EFFECTIVE SHEER VALUES 35KT OR HIGHER WILL BE POSSIBLE...SO IF THE MORE AGGRESSIVE GUIDANCE WAS TO VERIFY WE COULD SEE A MORE ORGANIZED SEVERE THREAT ROUGHLY ALONG/EAST OF HIGHWAY 83. REGARDLESS OF SEVERE THREAT...GFS/NAM BOTH SHOW THE BEST PRECIP SIGNAL IN OUR EAST/SOUTHEAST ALONG PRE FRONTAL TROUGH...AND I RAISED POPS ACCORDINGLY. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 225 PM MDT WED AUG 26 2015 A RIDGE WILL MOVE INTO THE ROCKIES THROUGH FRIDAY NIGHT AND THEN START MOVING INTO THE PLAINS SATURDAY. A SURFACE TROUGH WILL MOVE EAST ACROSS NORTHWEST KANSAS THURSDAY NIGHT FOLLOWED BY HIGH PRESSURE WHICH SHOULD LINGER OVER THE PLAINS THROUGH SATURDAY. A SHORTWAVE MOVING OVER THE TOP OF THE RIDGE WILL BE EXITING THE FA THURSDAY EVENING. PLAN TO CONTINUE CHANCE/SLIGHT CHANCE POPS FOR THE EVENING. DYNAMICS SHOULD BE EXITING THE FA AROUND 06Z FRIDAY. SUBSIDENCE BUILDS INTO THE FA FRIDAY AND CONTINUES THROUGH SATURDAY. POPS WILL BE NIL FOR THOSE PERIODS. MIN TEMPERATURES SHOULD RANGE FROM THE UPPER 50S IN EASTERN COLORADO TO THE LOWER 60S ELSEWHERE. MAX TEMPERATURES SHOULD REACH THE MID AND UPPER 80S. IN THE EXTENDED...(SATURDAY NIGHT THROUGH WEDNESDAY)... THE UPPER RIDGE WILL REMAIN OVER THE PLAINS THROUGH SUNDAY AND THEN MOVE EAST OF THE PLAINS MONDAY. THE FORECAST WILL REMAIN DRY THROUGH MONDAY DUE TO THE LACK OF SUFFICIENT MOISTURE AND FORCING. HOWEVER BY MONDAY EVENING MONSOONAL MOISTURE WILL BEGIN TO IMPACT THE AREA WITH A SLIGHT CHANCE OF THUNDERSTORMS EACH AFTERNOON AND EVENING THROUGH WEDNESDAY. MIN TEMPERATURES SHOULD COOL TO THE LOWER AND MID 60S. MAX TEMPERATURES SHOULD REACH THE LOWER 90S EACH DAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1150 AM MDT WED AUG 26 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. GUSTY WINDS SHOULD DEVELOP AT BOTH TERMINALS THIS AFTERNOON WITH INCREASED MIXING. AS WINDS DECREASE THIS EVENING A DEVELOPING LOW LEVEL JET WILL LEAD TO LOW LEVEL WIND SHEER 35-40 KT AT BOTH TERMINALS (FIRST AT KGLD AND THEN AT KMCK). AN APPROACHING UPPER LEVEL SYSTEM MAY BRING SHOWER OR THUNDERSTORMS TO EITHER TERMINAL BY MIDDAY THURSDAY...HOWEVER CONFIDENCE IS TOO LOW IN COVERAGE TO INCLUDE MENTION IN TAFS DURING THIS UPDATE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
111 PM MDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 110 PM MDT WED AUG 26 2015 WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS THE PLAINS WITH 596 DM CENTER AXIS EXTENDING NORTH OVER OUR CWA. SHORTWAVE TROUGH IS CURRENTLY ROTATING AROUND WESTERN EDGE OF RIDGE WITH MOISTURE PLUME EXTENDING ACROSS THE CENTRAL ROCKIES AHEAD OF THIS FEATURE. AT THE SURFACE LO PRESSURE EXTENDS FROM EASTERN MONTANA ACROSS EASTERN COLORADO AND OVER OUR CWA. A WEAK STATIONARY FRONT IS CURRENTLY IN PLACE FROM SW NEBRASKA AND ACROSS CENTRAL KANSAS (NEAR HLC). THIS AFTERNOON-TONIGHT...VERY DRY AIR MASS...STRONG CAP...AND LIMITED LARGE SCALE FORCING WILL CONTINUE TO LIMIT CONVECTIVE POTENTIAL. CAP MAY BEGIN TO WEAKEN ALONG STALLED FRONT IN OUR EASTERN CWA LATER THIS AFTERNOON...HOWEVER AT THIS POINT CONFIDENCE IS TOO LOW TO INCLUDE A MENTION OF SHOWERS/THUNDERSTORMS. AS WAS EXPECTED HOT TEMPERATURES AND FAVORABLE MIXING HAVE RESULTED IN VERY LOW RH VALUES THIS AFTERNOON ACROSS THE WESTERN HALF OF OF OUR FORECAST AREA...WITH SOME LOCATIONS GUSTING TO NEAR RFW CRITERIA. WITH FUELS STILL NOT CONSIDERED FAVORABLE FOR RAPID FIRE SPREAD I HAVE HELD BACK ON RFW ISSUANCE. THURSDAY...UPPER LEVEL TROUGH WILL ROTATE AROUND THE NORTH SIDE OF THE RIDGE AND DEEPEN AS IT TRACKS ACROSS THE NORTHERN PLAINS. LARGE SCALE FORCING WILL OVERSPREAD OUR CWA ON THE SOUTHERN EXTENT OF THIS FEATURE...WITH DRY AIR MASS INITIALLY LIMITING CONVECTIVE COVERAGE UNTIL LATER THURSDAY AFTERNOON. RETURN FLOW AHEAD OF APPROACHING FRONT MAY LEAD TO INCREASED TDS AND HIGHER CAPE VALUES ACROSS OUR EASTERN CWA. GFS AND NAM BOTH SHOWING VERY DIFFERENT PICTURE REGARDING MOISTURE/CAPE PROFILES WITH NAM SHOWING BETTER MOISTURE RETURN AND HIGHER CAPE BY 00Z. EFFECTIVE SHEER VALUES 35KT OR HIGHER WILL BE POSSIBLE...SO IF THE MORE AGGRESSIVE GUIDANCE WAS TO VERIFY WE COULD SEE A MORE ORGANIZED SEVERE THREAT ROUGHLY ALONG/EAST OF HIGHWAY 83. REGARDLESS OF SEVERE THREAT...GFS/NAM BOTH SHOW THE BEST PRECIP SIGNAL IN OUR EAST/SOUTHEAST ALONG PRE FRONTAL TROUGH...AND I RAISED POPS ACCORDINGLY. .LONG TERM...(SATURDAY THROUGH MONDAY) ISSUED AT 154 AM MDT WED AUG 26 2015 H5 RIDGE BUILDS OVER THE SOUTHWEST ON SATURDAY AND BEGINS MOVING EASTWARD. MID TO UPPER LEVEL FLOW BECOMES WESTERLY AND EVENTUALLY SOUTHWESTERLY ON SUNDAY AND MONDAY AS THE RIDGE MOVES OVER THE CENTRAL GULF COAST AND MID MISSISSIPPI VALLEY REGION. GOOD AGREEMENT BETWEEN THE GFS AND ECMWF ABOUT THE OVERALL PATTERN ARE LEADING TO ABOVE AVERAGE CONFIDENCE WITH REGARDS TO THE MOVEMENT OF THE RIDGE. MOST OF THE CWA WILL REMAIN DRY ON MONDAY AND TUESDAY WITH THE EXCEPTION OF EASTERN COLORADO DUE TO THE ADVECTION OF MONSOONAL MOISTURE ALONG THE WESTERN SIDE OF THE RIDGE WHERE SLIGHT RAIN CHANCES ARE POSSIBLE MONDAY EVENING AND INTO TUESDAY. ON TUESDAY THERE WILL BE ENOUGH MARGINAL INSTABILITY ALONG A WEAK THETA E BOUNDARY FOR ISOLATED THUNDERSTORM DEVELOPMENT IN THE WESTERN AND NORTHWESTERN PORTIONS OF THE CWA ONCE MORE DURING THE AFTERNOON AND EARLY EVENING. THIS BOUNDARY WILL REMAIN IN PLACE FOR THE MOST PART THROUGHOUT THE FORECAST PERIOD AND LEAD TO SLIGHT RAIN AND THUNDERSTORM CHANCES ONCE MORE ON WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1150 AM MDT WED AUG 26 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK TERMINALS. GUSTY WINDS SHOULD DEVELOP AT BOTH TERMINALS THIS AFTERNOON WITH INCREASED MIXING. AS WINDS DECREASE THIS EVENING A DEVELOPING LOW LEVEL JET WILL LEAD TO LOW LEVEL WIND SHEER 35-40 KT AT BOTH TERMINALS (FIRST AT KGLD AND THEN AT KMCK). AN APPROACHING UPPER LEVEL SYSTEM MAY BRING SHOWER OR THUNDERSTORMS TO EITHER TERMINAL BY MIDDAY THURSDAY...HOWEVER CONFIDENCE IS TOO LOW IN COVERAGE TO INCLUDE MENTION IN TAFS DURING THIS UPDATE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...TL AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
156 AM MDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 201 PM MDT TUE AUG 25 2015 EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS RIDGE IN PLACE ACROSS CENTRAL ROCKIES. A PLUME OF MONSOONAL MOISTURE IS ROTATING FROM THE FOUR CORNERS REGION ROTATING INTO THE CENTRAL ROCKIES. AT THE SURFACE LEE TROUGH IS IN PLACE ACROSS EASTERN COLORADO WITH MAIN AXIS EXTENDING ACROSS SE COLORADO INTO SW KANSAS. THIS AFTERNOON-EVENING...CONVECTIVE INITIATION WILL MAINLY BE ALONG TROUGH AXIS AND ALONG HIGHER TERRAIN IN COLORADO (WEST OF OUR CWA. CURRENTLY VERY HIGH CINH IS PREVENTING LOCAL INITIATION...HOWEVER CAP SHOULD WEAKEN ACROSS WESTERN PARTS OF THE CWA WHERE ISOLATED THUNDERSTORMS WILL BE POSSIBLE. THE AREAS WHERE CAP IS MOST LIKELY TO BREAK ALSO CORRELATE WITH LOWEST CAPE/DRIEST AIR MASS...SO COVERAGE IS LIMITED. BEYOND A VERY SMALL THREAT FOR DRY MICROBURST POTENTIAL...CONFIDENCE IN ANY SEVERE THREAT IS LOW. WEDNESDAY...THERE IS A STRONGER PRECIP SIGNAL THAN TODAY FROM SOME GUIDANCE...HOWEVER SOUNDING ACTUALLY SHOW AN EVEN DRIER AIR MASS AND STRONGER CAP THAN TODAY. VERY HOT AIR MASS WILL SUPPORT HIGHS APPROACHING 100F OVER PARTS OF THE CWA...AND DRY ADIABATIC MIXING MAY SUPPORT RH VALUES AND WINDS NEAR RED FLAG THRESHOLDS. WILL NEED TO MONITOR...PARTICULARLY IN THE WESTERN PART OF THE CWA. .LONG TERM...(SATURDAY THROUGH MONDAY) ISSUED AT 154 AM MDT WED AUG 26 2015 H5 RIDGE BUILDS OVER THE SOUTHWEST ON SATURDAY AND BEGINS MOVING EASTWARD. MID TO UPPER LEVEL FLOW BECOMES WESTERLY AND EVENTUALLY SOUTHWESTERLY ON SUNDAY AND MONDAY AS THE RIDGE MOVES OVER THE CENTRAL GULF COAST AND MID MISSISSIPPI VALLEY REGION. GOOD AGREEMENT BETWEEN THE GFS AND ECMWF ABOUT THE OVERALL PATTERN ARE LEADING TO ABOVE AVERAGE CONFIDENCE WITH REGARDS TO THE MOVEMENT OF THE RIDGE. MOST OF THE CWA WILL REMAIN DRY ON MONDAY AND TUESDAY WITH THE EXCEPTION OF EASTERN COLORADO DUE TO THE ADVECTION OF MONSOONAL MOISTURE ALONG THE WESTERN SIDE OF THE RIDGE WHERE SLIGHT RAIN CHANCES ARE POSSIBLE MONDAY EVENING AND INTO TUESDAY. ON TUESDAY THERE WILL BE ENOUGH MARGINAL INSTABILITY ALONG A WEAK THETA E BOUNDARY FOR ISOLATED THUNDERSTORM DEVELOPMENT IN THE WESTERN AND NORTHWESTERN PORTIONS OF THE CWA ONCE MORE DURING THE AFTERNOON AND EARLY EVENING. THIS BOUNDARY WILL REMAIN IN PLACE FOR THE MOST PART THROUGHOUT THE FORECAST PERIOD AND LEAD TO SLIGHT RAIN AND THUNDERSTORM CHANCES ONCE MORE ON WEDNESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1124 PM MDT TUE AUG 25 2015 PATCHY FOG WILL BE POSSIBLE AT EITHER KGLD OR KMCK AROUND SUNRISE AS TEMPERATURES COOL TO THE DEW POINT. HOWEVER ANY FOG THAT DEVELOPS WILL QUICKLY SCOUR OUT WITH BREEZY SOUTHWESTERLY WINDS BY MID MORNING. OTHERWISE VFR EXPECTED WITH UPPER RIDGE REMAINING OVER THE HIGH PLAINS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...TL AVIATION...024
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 PM EDT WED AUG 26 2015 .UPDATE... ISSUED AT 150 PM EDT WED AUG 26 2015 CLOUD DEVELOPMENT HAS BEEN MORE EXTENSIVE THAN YESTERDAY AND GREATER THAN EARLIER ANTICIPATED. HAVE UPDATED NDFD AND ASSOCIATED PRODUCTS TO ACCOUNT FOR MORE CLOUD AND SLIGHTLY LOWER AFTERNOON TEMPERATURES. UPDATE ISSUED AT 1032 AM EDT WED AUG 26 2015 CLOUD DECK HAS BEEN ADVECTING INTO THE NORTHERN PART OF THE FORECAST AREA...BUT ALSO SHOWING SOME SIGNS OF DIMINISHMENT AS IT MOVES SOUTHEAST ACROSS OUR AREA. EXPECT THIS BASIC TREND TO CONTINUE...ALONG WITH DEVELOPMENT OF SOME CU/SC JUST SOUTH OF THE MAIN CLOUD DECK DURING THE AFTERNOON. HAVE INCREASED CLOUD COVER IN THE SKY COVER GRIDS TO BETTER REFLECT CURRENT CONDITIONS AND EXPECTED TRENDS. HAVE ALSO MADE SOME ADJUSTMENTS TO TEMPERATURE AND DEWPOINT GRIDS. NDFD AND ASSOCIATED PRODUCTS HAVE BEEN UPDATED. UPDATE ISSUED AT 745 AM EDT WED AUG 26 2015 DID A QUICK UPDATE TO TOUCH UP THE SKY COVER AND WX GRIDS FOR THE FOG. DID ALSO TWEAK THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 350 AM EDT WED AUG 26 2015 06Z SFC ANALYSIS SHOWS HIGH PRESSURE THROUGH KENTUCKY STRETCHED BACK INTO THE HIGH PLAINS. THIS PLEASANT AIR MASS HAS ALLOWED FOR ANOTHER SEASONABLY COOL NIGHT WHERE A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT HAS SET UP. THE RADIATIONAL COOLING...EXPECTED TO GET MUCH OF THE AREA DOWN TO NEAR RECORD LOWS THIS NIGHT...HAS BEEN DISRUPTED BY A PESKY LAYER OF CLOUDS AROUND 5K FEET PARKED OVER MUCH OF EAST KENTUCKY. THIS CLOUD PATCH IS SLOWLY ERODING FROM THE SOUTHEAST AND NORTHWEST BUT WILL STILL PROVIDE A BLANKETING EFFECT FOR TEMPERATURES ACROSS THE CENTRAL PARTS OF THE CWA INTO THE PRE-DAWN HOURS. THIS DISRUPTION MAY ALSO HINDER THE FORMATION OF FOG FOR MUCH OF THE AREA...AS WELL...THOUGH STILL EXPECT SOME ALONG THE DEEPER RIVER VALLEYS...LOCALLY DENSE FOR A BRIEF TIME. AS IT STANDS...TEMPERATURES VARY FROM THE LOW 60S ON THE RIDGES TO A FEW POCKETS OF LOWER 50S IN THE SHELTERED VALLEYS BENEATH CLEAR SKIES. DEWPOINTS ARE GENERALLY IN THE LOW TO MID 50S ACROSS THE AREA WITH LIGHT WINDS AND ONLY A FEW HINTS OF FOG STARTING TO FORM IN THE OBS AND WEB CAMS. THE MODELS ARE IN QUITE GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM FOR THE OHIO VALLEY IN THE WAKE OF THE DEPARTING TROUGH TO THE NORTH. LOW HEIGHTS...WEAK RIPPLES...AND BROAD NORTHWEST FLOW WILL BE THE RULE AT THE MID LEVELS ACROSS THE AREA THROUGH THE DAY THURSDAY. THE CLOSED LOW WILL REMAIN CLOSE BY TODAY... THOUGH...WITH SOME OF ITS CORE ENERGY BRUSHING PAST JUST TO THE NORTH OF THE OHIO RIVER INTO THURSDAY MORNING. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A LEAN TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 FOR DETAILS. EAST KENTUCKY WILL ENJOY A CONTINUATION OF OUR CURRENT TASTE OF THE BEST FALL WEATHER HAS TO OFFER. PLEASANT AFTERNOON HUMIDITY LEVELS...PARTLY TO MOSTLY SUNNY SKIES...AND TEMPERATURES TOPPING OUT IN THE MID 70S ARE AGAIN ON THE DOCKET FOR TODAY AND THURSDAY. THE ONLY DRAW BACK MAY BE THE PREVALENCE OF MID RANGE CLOUDS SLIPPING SOUTH INTO OUR AREA FROM BENEATH THE UPPER LOW. TONIGHT WILL FEATURE ANOTHER RELATIVELY COOL ONE WITH LESS CLOUDS ANTICIPATED TO SLOW THE TEMPERATURE/S DESCENT. AS SUCH...RIDGE TO VALLEY TEMPERATURE DIFFERENCES WILL PLAY OUT THROUGH THE NIGHT ALONG WITH THE FORMATION OF RIVER VALLEY FOG TOWARDS DAWN THURSDAY. ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE EVENING BEFORE INITIATING WITH THE SUPERBLEND THROUGH THE DAY THURSDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEM EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD...IN LINE WITH ALL MOS GUIDANCE. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 AM EDT WED AUG 26 2015 AT UPPER LEVELS...A STRONG MID LEVEL RIDGE DEVELOPS OVER THE WESTERN CONUS WITH A RIDGE AXIS EXTENDING NEWD INTO THE UPPER MIDWEST. EMBEDDED WITHIN THIS FLOW...A SHORTWAVE TROUGH DEVELOPS AND TRAVERSES THE RIDGE TOWARDS THE MID MS VALLEY REGION BY SATURDAY AFTERNOON. MEANWHILE...A SFC LOW DEVELOPS IN THE GULF AND MOVES NWD...GETTING INGESTED INTO THE SHORTWAVE TROUGH AS IT CROSSES THROUGH THE OHIO VALLEY...ULTIMATELY STRENGTHENING THE TROUGH. THERE ARE MODEL DIFFERENCES WITH HOW THIS SITUATION EVOLVES...WITH THE GFS BEING THE MORE AGGRESSIVE OF THE TWO MODELS. IN TERMS OF SENSIBLE WEATHER...FRIDAY WILL BE ANOTHER BEAUTIFUL AND DRY DAY BEFORE MOISTURE AND HUMIDITY RETURNS ON SATURDAY. TEMPERATURES WILL BEGIN JUST BELOW NORMAL ON FRIDAY BUT THEN GRADUALLY WARM AND RETURN BACK TO THE MID 80S BY MONDAY. THERE WILL BE CHANCES FOR AFTERNOON SHOWERS AND A FEW THUNDERSTORMS SATURDAY THROUGH WEDNESDAY...WITH THE BEST CHANCES ON SUNDAY AFTERNOON WITH THE PASSAGE OF THE UPPER LEVEL SHORTWAVE. THOUGH ONE THING TO NOTE IS THE LACK OF MOISTURE IN THE MODEL SOUNDINGS THROUGH THE EXTENDED PERIOD. EVEN ON SUNDAY...THE UPPER LEVELS ARE SATURATED BUT THE LOW LEVELS REMAIN FAIRLY DRY. THEREFORE HAVE MAINTAINED MAINLY SLIGHT CHANCE POPS THROUGH THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 117 PM EDT WED AUG 26 2015 SURFACE HIGH PRESSURE WILL CONTINUE TO CONTROL OUR WEATHER WITH VFR CONDITIONS PREVAILING THROUGH THE NEXT 36 HOURS. AN EXTENSIVE BROKEN TO OVERCAST CLOUD DECK AROUND 5K FEET WILL BE SLOW TO DISSIPATE TONIGHT...BUT CLOUDS SHOULD EVENTUALLY SCATTER OUT. ANY FOG FORMATION TONIGHT WILL DEPEND ON HOW LONG THE CLOUDS LINGER...WITH FOG FORMATION LESS LIKELY THE LONGER THE CLOUDS LAST. AT THIS POINT WILL INCLUDE A COUPLE OF HOURS OF MVFR VISIBILITY AT SME AROUND DAWN...BUT WILL KEEP ALL OTHER TAF SITES AT VFR. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...JVM AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
117 PM EDT WED AUG 26 2015 .UPDATE... ISSUED AT 1032 AM EDT WED AUG 26 2015 CLOUD DECK HAS BEEN ADVECTING INTO THE NORTHERN PART OF THE FORECAST AREA...BUT ALSO SHOWING SOME SIGNS OF DIMINISHMENT AS IT MOVES SOUTHEAST ACROSS OUR AREA. EXPECT THIS BASIC TREND TO CONTINUE...ALONG WITH DEVELOPMENT OF SOME CU/SC JUST SOUTH OF THE MAIN CLOUD DECK DURING THE AFTERNOON. HAVE INCREASED CLOUD COVER IN THE SKY COVER GRIDS TO BETTER REFLECT CURRENT CONDITIONS AND EXPECTED TRENDS. HAVE ALSO MADE SOME ADJUSTMENTS TO TEMPERATURE AND DEWPOINT GRIDS. NDFD AND ASSOCIATED PRODUCTS HAVE BEEN UPDATED. UPDATE ISSUED AT 745 AM EDT WED AUG 26 2015 DID A QUICK UPDATE TO TOUCH UP THE SKY COVER AND WX GRIDS FOR THE FOG. DID ALSO TWEAK THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 350 AM EDT WED AUG 26 2015 06Z SFC ANALYSIS SHOWS HIGH PRESSURE THROUGH KENTUCKY STRETCHED BACK INTO THE HIGH PLAINS. THIS PLEASANT AIR MASS HAS ALLOWED FOR ANOTHER SEASONABLY COOL NIGHT WHERE A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT HAS SET UP. THE RADIATIONAL COOLING...EXPECTED TO GET MUCH OF THE AREA DOWN TO NEAR RECORD LOWS THIS NIGHT...HAS BEEN DISRUPTED BY A PESKY LAYER OF CLOUDS AROUND 5K FEET PARKED OVER MUCH OF EAST KENTUCKY. THIS CLOUD PATCH IS SLOWLY ERODING FROM THE SOUTHEAST AND NORTHWEST BUT WILL STILL PROVIDE A BLANKETING EFFECT FOR TEMPERATURES ACROSS THE CENTRAL PARTS OF THE CWA INTO THE PRE-DAWN HOURS. THIS DISRUPTION MAY ALSO HINDER THE FORMATION OF FOG FOR MUCH OF THE AREA...AS WELL...THOUGH STILL EXPECT SOME ALONG THE DEEPER RIVER VALLEYS...LOCALLY DENSE FOR A BRIEF TIME. AS IT STANDS...TEMPERATURES VARY FROM THE LOW 60S ON THE RIDGES TO A FEW POCKETS OF LOWER 50S IN THE SHELTERED VALLEYS BENEATH CLEAR SKIES. DEWPOINTS ARE GENERALLY IN THE LOW TO MID 50S ACROSS THE AREA WITH LIGHT WINDS AND ONLY A FEW HINTS OF FOG STARTING TO FORM IN THE OBS AND WEB CAMS. THE MODELS ARE IN QUITE GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM FOR THE OHIO VALLEY IN THE WAKE OF THE DEPARTING TROUGH TO THE NORTH. LOW HEIGHTS...WEAK RIPPLES...AND BROAD NORTHWEST FLOW WILL BE THE RULE AT THE MID LEVELS ACROSS THE AREA THROUGH THE DAY THURSDAY. THE CLOSED LOW WILL REMAIN CLOSE BY TODAY... THOUGH...WITH SOME OF ITS CORE ENERGY BRUSHING PAST JUST TO THE NORTH OF THE OHIO RIVER INTO THURSDAY MORNING. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A LEAN TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 FOR DETAILS. EAST KENTUCKY WILL ENJOY A CONTINUATION OF OUR CURRENT TASTE OF THE BEST FALL WEATHER HAS TO OFFER. PLEASANT AFTERNOON HUMIDITY LEVELS...PARTLY TO MOSTLY SUNNY SKIES...AND TEMPERATURES TOPPING OUT IN THE MID 70S ARE AGAIN ON THE DOCKET FOR TODAY AND THURSDAY. THE ONLY DRAW BACK MAY BE THE PREVALENCE OF MID RANGE CLOUDS SLIPPING SOUTH INTO OUR AREA FROM BENEATH THE UPPER LOW. TONIGHT WILL FEATURE ANOTHER RELATIVELY COOL ONE WITH LESS CLOUDS ANTICIPATED TO SLOW THE TEMPERATURE/S DESCENT. AS SUCH...RIDGE TO VALLEY TEMPERATURE DIFFERENCES WILL PLAY OUT THROUGH THE NIGHT ALONG WITH THE FORMATION OF RIVER VALLEY FOG TOWARDS DAWN THURSDAY. ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE EVENING BEFORE INITIATING WITH THE SUPERBLEND THROUGH THE DAY THURSDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEM EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD...IN LINE WITH ALL MOS GUIDANCE. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 AM EDT WED AUG 26 2015 AT UPPER LEVELS...A STRONG MID LEVEL RIDGE DEVELOPS OVER THE WESTERN CONUS WITH A RIDGE AXIS EXTENDING NEWD INTO THE UPPER MIDWEST. EMBEDDED WITHIN THIS FLOW...A SHORTWAVE TROUGH DEVELOPS AND TRAVERSES THE RIDGE TOWARDS THE MID MS VALLEY REGION BY SATURDAY AFTERNOON. MEANWHILE...A SFC LOW DEVELOPS IN THE GULF AND MOVES NWD...GETTING INGESTED INTO THE SHORTWAVE TROUGH AS IT CROSSES THROUGH THE OHIO VALLEY...ULTIMATELY STRENGTHENING THE TROUGH. THERE ARE MODEL DIFFERENCES WITH HOW THIS SITUATION EVOLVES...WITH THE GFS BEING THE MORE AGGRESSIVE OF THE TWO MODELS. IN TERMS OF SENSIBLE WEATHER...FRIDAY WILL BE ANOTHER BEAUTIFUL AND DRY DAY BEFORE MOISTURE AND HUMIDITY RETURNS ON SATURDAY. TEMPERATURES WILL BEGIN JUST BELOW NORMAL ON FRIDAY BUT THEN GRADUALLY WARM AND RETURN BACK TO THE MID 80S BY MONDAY. THERE WILL BE CHANCES FOR AFTERNOON SHOWERS AND A FEW THUNDERSTORMS SATURDAY THROUGH WEDNESDAY...WITH THE BEST CHANCES ON SUNDAY AFTERNOON WITH THE PASSAGE OF THE UPPER LEVEL SHORTWAVE. THOUGH ONE THING TO NOTE IS THE LACK OF MOISTURE IN THE MODEL SOUNDINGS THROUGH THE EXTENDED PERIOD. EVEN ON SUNDAY...THE UPPER LEVELS ARE SATURATED BUT THE LOW LEVELS REMAIN FAIRLY DRY. THEREFORE HAVE MAINTAINED MAINLY SLIGHT CHANCE POPS THROUGH THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 117 PM EDT WED AUG 26 2015 SURFACE HIGH PRESSURE WILL CONTINUE TO CONTROL OUR WEATHER WITH VFR CONDITIONS PREVAILING THROUGH THE NEXT 36 HOURS. AN EXTENSIVE BROKEN TO OVERCAST CLOUD DECK AROUND 5K FEET WILL BE SLOW TO DISSIPATE TONIGHT...BUT CLOUDS SHOULD EVENTUALLY SCATTER OUT. ANY FOG FORMATION TONIGHT WILL DEPEND ON HOW LONG THE CLOUDS LINGER...WITH FOG FORMATION LESS LIKELY THE LONGER THE CLOUDS LAST. AT THIS POINT WILL INCLUDE A COUPLE OF HOURS OF MVFR VISIBILITY AT SME AROUND DAWN...BUT WILL KEEP ALL OTHER TAF SITES AT VFR. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...JVM AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1032 AM EDT WED AUG 26 2015 .UPDATE... ISSUED AT 1032 AM EDT WED AUG 26 2015 CLOUD DECK HAS BEEN ADVECTING INTO THE NORTHERN PART OF THE FORECAST AREA...BUT ALSO SHOWING SOME SIGNS OF DIMINISHMENT AS IT MOVES SOUTHEAST ACROSS OUR AREA. EXPECT THIS BASIC TREND TO CONTINUE...ALONG WITH DEVELOPMENT OF SOME CU/SC JUST SOUTH OF THE MAIN CLOUD DECK DURING THE AFTERNOON. HAVE INCREASED CLOUD COVER IN THE SKY COVER GRIDS TO BETTER REFLECT CURRENT CONDITIONS AND EXPECTED TRENDS. HAVE ALSO MADE SOME ADJUSTMENTS TO TEMPERATURE AND DEWPOINT GRIDS. NDFD AND ASSOCIATED PRODUCTS HAVE BEEN UPDATED. UPDATE ISSUED AT 745 AM EDT WED AUG 26 2015 DID A QUICK UPDATE TO TOUCH UP THE SKY COVER AND WX GRIDS FOR THE FOG. DID ALSO TWEAK THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 350 AM EDT WED AUG 26 2015 06Z SFC ANALYSIS SHOWS HIGH PRESSURE THROUGH KENTUCKY STRETCHED BACK INTO THE HIGH PLAINS. THIS PLEASANT AIR MASS HAS ALLOWED FOR ANOTHER SEASONABLY COOL NIGHT WHERE A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT HAS SET UP. THE RADIATIONAL COOLING...EXPECTED TO GET MUCH OF THE AREA DOWN TO NEAR RECORD LOWS THIS NIGHT...HAS BEEN DISRUPTED BY A PESKY LAYER OF CLOUDS AROUND 5K FEET PARKED OVER MUCH OF EAST KENTUCKY. THIS CLOUD PATCH IS SLOWLY ERODING FROM THE SOUTHEAST AND NORTHWEST BUT WILL STILL PROVIDE A BLANKETING EFFECT FOR TEMPERATURES ACROSS THE CENTRAL PARTS OF THE CWA INTO THE PRE-DAWN HOURS. THIS DISRUPTION MAY ALSO HINDER THE FORMATION OF FOG FOR MUCH OF THE AREA...AS WELL...THOUGH STILL EXPECT SOME ALONG THE DEEPER RIVER VALLEYS...LOCALLY DENSE FOR A BRIEF TIME. AS IT STANDS...TEMPERATURES VARY FROM THE LOW 60S ON THE RIDGES TO A FEW POCKETS OF LOWER 50S IN THE SHELTERED VALLEYS BENEATH CLEAR SKIES. DEWPOINTS ARE GENERALLY IN THE LOW TO MID 50S ACROSS THE AREA WITH LIGHT WINDS AND ONLY A FEW HINTS OF FOG STARTING TO FORM IN THE OBS AND WEB CAMS. THE MODELS ARE IN QUITE GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM FOR THE OHIO VALLEY IN THE WAKE OF THE DEPARTING TROUGH TO THE NORTH. LOW HEIGHTS...WEAK RIPPLES...AND BROAD NORTHWEST FLOW WILL BE THE RULE AT THE MID LEVELS ACROSS THE AREA THROUGH THE DAY THURSDAY. THE CLOSED LOW WILL REMAIN CLOSE BY TODAY... THOUGH...WITH SOME OF ITS CORE ENERGY BRUSHING PAST JUST TO THE NORTH OF THE OHIO RIVER INTO THURSDAY MORNING. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A LEAN TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 FOR DETAILS. EAST KENTUCKY WILL ENJOY A CONTINUATION OF OUR CURRENT TASTE OF THE BEST FALL WEATHER HAS TO OFFER. PLEASANT AFTERNOON HUMIDITY LEVELS...PARTLY TO MOSTLY SUNNY SKIES...AND TEMPERATURES TOPPING OUT IN THE MID 70S ARE AGAIN ON THE DOCKET FOR TODAY AND THURSDAY. THE ONLY DRAW BACK MAY BE THE PREVALENCE OF MID RANGE CLOUDS SLIPPING SOUTH INTO OUR AREA FROM BENEATH THE UPPER LOW. TONIGHT WILL FEATURE ANOTHER RELATIVELY COOL ONE WITH LESS CLOUDS ANTICIPATED TO SLOW THE TEMPERATURE/S DESCENT. AS SUCH...RIDGE TO VALLEY TEMPERATURE DIFFERENCES WILL PLAY OUT THROUGH THE NIGHT ALONG WITH THE FORMATION OF RIVER VALLEY FOG TOWARDS DAWN THURSDAY. ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE EVENING BEFORE INITIATING WITH THE SUPERBLEND THROUGH THE DAY THURSDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEM EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD...IN LINE WITH ALL MOS GUIDANCE. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 AM EDT WED AUG 26 2015 AT UPPER LEVELS...A STRONG MID LEVEL RIDGE DEVELOPS OVER THE WESTERN CONUS WITH A RIDGE AXIS EXTENDING NEWD INTO THE UPPER MIDWEST. EMBEDDED WITHIN THIS FLOW...A SHORTWAVE TROUGH DEVELOPS AND TRAVERSES THE RIDGE TOWARDS THE MID MS VALLEY REGION BY SATURDAY AFTERNOON. MEANWHILE...A SFC LOW DEVELOPS IN THE GULF AND MOVES NWD...GETTING INGESTED INTO THE SHORTWAVE TROUGH AS IT CROSSES THROUGH THE OHIO VALLEY...ULTIMATELY STRENGTHENING THE TROUGH. THERE ARE MODEL DIFFERENCES WITH HOW THIS SITUATION EVOLVES...WITH THE GFS BEING THE MORE AGGRESSIVE OF THE TWO MODELS. IN TERMS OF SENSIBLE WEATHER...FRIDAY WILL BE ANOTHER BEAUTIFUL AND DRY DAY BEFORE MOISTURE AND HUMIDITY RETURNS ON SATURDAY. TEMPERATURES WILL BEGIN JUST BELOW NORMAL ON FRIDAY BUT THEN GRADUALLY WARM AND RETURN BACK TO THE MID 80S BY MONDAY. THERE WILL BE CHANCES FOR AFTERNOON SHOWERS AND A FEW THUNDERSTORMS SATURDAY THROUGH WEDNESDAY...WITH THE BEST CHANCES ON SUNDAY AFTERNOON WITH THE PASSAGE OF THE UPPER LEVEL SHORTWAVE. THOUGH ONE THING TO NOTE IS THE LACK OF MOISTURE IN THE MODEL SOUNDINGS THROUGH THE EXTENDED PERIOD. EVEN ON SUNDAY...THE UPPER LEVELS ARE SATURATED BUT THE LOW LEVELS REMAIN FAIRLY DRY. THEREFORE HAVE MAINTAINED MAINLY SLIGHT CHANCE POPS THROUGH THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 800 AM EDT WED AUG 26 2015 VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 TO 36 HOURS FOR MOST OF EASTERN KENTUCKY. THE EXCEPTION WILL BE SOME RIVER VALLEY FOG TOWARDS DAWN THURSDAY. THIS SHOULD NOT IMPACT MOST OF THE TAF SITES...WITH THE BEST SHOT BEING KSME. FOR THIS...HAVE INCLUDED A BRIEF PERIOD OF MVFR VIS. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...JVM AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
800 AM EDT WED AUG 26 2015 .UPDATE... ISSUED AT 745 AM EDT WED AUG 26 2015 DID A QUICK UPDATE TO TOUCH UP THE SKY COVER AND WX GRIDS FOR THE FOG. DID ALSO TWEAK THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 350 AM EDT WED AUG 26 2015 06Z SFC ANALYSIS SHOWS HIGH PRESSURE THROUGH KENTUCKY STRETCHED BACK INTO THE HIGH PLAINS. THIS PLEASANT AIR MASS HAS ALLOWED FOR ANOTHER SEASONABLY COOL NIGHT WHERE A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT HAS SET UP. THE RADIATIONAL COOLING...EXPECTED TO GET MUCH OF THE AREA DOWN TO NEAR RECORD LOWS THIS NIGHT...HAS BEEN DISRUPTED BY A PESKY LAYER OF CLOUDS AROUND 5K FEET PARKED OVER MUCH OF EAST KENTUCKY. THIS CLOUD PATCH IS SLOWLY ERODING FROM THE SOUTHEAST AND NORTHWEST BUT WILL STILL PROVIDE A BLANKETING EFFECT FOR TEMPERATURES ACROSS THE CENTRAL PARTS OF THE CWA INTO THE PRE-DAWN HOURS. THIS DISRUPTION MAY ALSO HINDER THE FORMATION OF FOG FOR MUCH OF THE AREA...AS WELL...THOUGH STILL EXPECT SOME ALONG THE DEEPER RIVER VALLEYS...LOCALLY DENSE FOR A BRIEF TIME. AS IT STANDS...TEMPERATURES VARY FROM THE LOW 60S ON THE RIDGES TO A FEW POCKETS OF LOWER 50S IN THE SHELTERED VALLEYS BENEATH CLEAR SKIES. DEWPOINTS ARE GENERALLY IN THE LOW TO MID 50S ACROSS THE AREA WITH LIGHT WINDS AND ONLY A FEW HINTS OF FOG STARTING TO FORM IN THE OBS AND WEB CAMS. THE MODELS ARE IN QUITE GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM FOR THE OHIO VALLEY IN THE WAKE OF THE DEPARTING TROUGH TO THE NORTH. LOW HEIGHTS...WEAK RIPPLES...AND BROAD NORTHWEST FLOW WILL BE THE RULE AT THE MID LEVELS ACROSS THE AREA THROUGH THE DAY THURSDAY. THE CLOSED LOW WILL REMAIN CLOSE BY TODAY... THOUGH...WITH SOME OF ITS CORE ENERGY BRUSHING PAST JUST TO THE NORTH OF THE OHIO RIVER INTO THURSDAY MORNING. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A LEAN TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 FOR DETAILS. EAST KENTUCKY WILL ENJOY A CONTINUATION OF OUR CURRENT TASTE OF THE BEST FALL WEATHER HAS TO OFFER. PLEASANT AFTERNOON HUMIDITY LEVELS...PARTLY TO MOSTLY SUNNY SKIES...AND TEMPERATURES TOPPING OUT IN THE MID 70S ARE AGAIN ON THE DOCKET FOR TODAY AND THURSDAY. THE ONLY DRAW BACK MAY BE THE PREVALENCE OF MID RANGE CLOUDS SLIPPING SOUTH INTO OUR AREA FROM BENEATH THE UPPER LOW. TONIGHT WILL FEATURE ANOTHER RELATIVELY COOL ONE WITH LESS CLOUDS ANTICIPATED TO SLOW THE TEMPERATURE/S DESCENT. AS SUCH...RIDGE TO VALLEY TEMPERATURE DIFFERENCES WILL PLAY OUT THROUGH THE NIGHT ALONG WITH THE FORMATION OF RIVER VALLEY FOG TOWARDS DAWN THURSDAY. ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE EVENING BEFORE INITIATING WITH THE SUPERBLEND THROUGH THE DAY THURSDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEM EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD...IN LINE WITH ALL MOS GUIDANCE. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 AM EDT WED AUG 26 2015 AT UPPER LEVELS...A STRONG MID LEVEL RIDGE DEVELOPS OVER THE WESTERN CONUS WITH A RIDGE AXIS EXTENDING NEWD INTO THE UPPER MIDWEST. EMBEDDED WITHIN THIS FLOW...A SHORTWAVE TROUGH DEVELOPS AND TRAVERSES THE RIDGE TOWARDS THE MID MS VALLEY REGION BY SATURDAY AFTERNOON. MEANWHILE...A SFC LOW DEVELOPS IN THE GULF AND MOVES NWD...GETTING INGESTED INTO THE SHORTWAVE TROUGH AS IT CROSSES THROUGH THE OHIO VALLEY...ULTIMATELY STRENGTHENING THE TROUGH. THERE ARE MODEL DIFFERENCES WITH HOW THIS SITUATION EVOLVES...WITH THE GFS BEING THE MORE AGGRESSIVE OF THE TWO MODELS. IN TERMS OF SENSIBLE WEATHER...FRIDAY WILL BE ANOTHER BEAUTIFUL AND DRY DAY BEFORE MOISTURE AND HUMIDITY RETURNS ON SATURDAY. TEMPERATURES WILL BEGIN JUST BELOW NORMAL ON FRIDAY BUT THEN GRADUALLY WARM AND RETURN BACK TO THE MID 80S BY MONDAY. THERE WILL BE CHANCES FOR AFTERNOON SHOWERS AND A FEW THUNDERSTORMS SATURDAY THROUGH WEDNESDAY...WITH THE BEST CHANCES ON SUNDAY AFTERNOON WITH THE PASSAGE OF THE UPPER LEVEL SHORTWAVE. THOUGH ONE THING TO NOTE IS THE LACK OF MOISTURE IN THE MODEL SOUNDINGS THROUGH THE EXTENDED PERIOD. EVEN ON SUNDAY...THE UPPER LEVELS ARE SATURATED BUT THE LOW LEVELS REMAIN FAIRLY DRY. THEREFORE HAVE MAINTAINED MAINLY SLIGHT CHANCE POPS THROUGH THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 800 AM EDT WED AUG 26 2015 VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 TO 36 HOURS FOR MOST OF EASTERN KENTUCKY. THE EXCEPTION WILL BE SOME RIVER VALLEY FOG TOWARDS DAWN THURSDAY. THIS SHOULD NOT IMPACT MOST OF THE TAF SITES...WITH THE BEST SHOT BEING KSME. FOR THIS...HAVE INCLUDED A BRIEF PERIOD OF MVFR VIS. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...JVM AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
350 AM EDT WED AUG 26 2015 .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 350 AM EDT WED AUG 26 2015 06Z SFC ANALYSIS SHOWS HIGH PRESSURE THROUGH KENTUCKY STRETCHED BACK INTO THE HIGH PLAINS. THIS PLEASANT AIR MASS HAS ALLOWED FOR ANOTHER SEASONABLY COOL NIGHT WHERE A SMALL RIDGE TO VALLEY TEMPERATURE SPLIT HAS SET UP. THE RADIATIONAL COOLING...EXPECTED TO GET MUCH OF THE AREA DOWN TO NEAR RECORD LOWS THIS NIGHT...HAS BEEN DISRUPTED BY A PESKY LAYER OF CLOUDS AROUND 5K FEET PARKED OVER MUCH OF EAST KENTUCKY. THIS CLOUD PATCH IS SLOWLY ERODING FROM THE SOUTHEAST AND NORTHWEST BUT WILL STILL PROVIDE A BLANKETING EFFECT FOR TEMPERATURES ACROSS THE CENTRAL PARTS OF THE CWA INTO THE PRE-DAWN HOURS. THIS DISRUPTION MAY ALSO HINDER THE FORMATION OF FOG FOR MUCH OF THE AREA...AS WELL...THOUGH STILL EXPECT SOME ALONG THE DEEPER RIVER VALLEYS...LOCALLY DENSE FOR A BRIEF TIME. AS IT STANDS...TEMPERATURES VARY FROM THE LOW 60S ON THE RIDGES TO A FEW POCKETS OF LOWER 50S IN THE SHELTERED VALLEYS BENEATH CLEAR SKIES. DEWPOINTS ARE GENERALLY IN THE LOW TO MID 50S ACROSS THE AREA WITH LIGHT WINDS AND ONLY A FEW HINTS OF FOG STARTING TO FORM IN THE OBS AND WEB CAMS. THE MODELS ARE IN QUITE GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM FOR THE OHIO VALLEY IN THE WAKE OF THE DEPARTING TROUGH TO THE NORTH. LOW HEIGHTS...WEAK RIPPLES...AND BROAD NORTHWEST FLOW WILL BE THE RULE AT THE MID LEVELS ACROSS THE AREA THROUGH THE DAY THURSDAY. THE CLOSED LOW WILL REMAIN CLOSE BY TODAY... THOUGH...WITH SOME OF ITS CORE ENERGY BRUSHING PAST JUST TO THE NORTH OF THE OHIO RIVER INTO THURSDAY MORNING. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A LEAN TOWARD THE HIGHER RESOLUTION HRRR AND NAM12 FOR DETAILS. EAST KENTUCKY WILL ENJOY A CONTINUATION OF OUR CURRENT TASTE OF THE BEST FALL WEATHER HAS TO OFFER. PLEASANT AFTERNOON HUMIDITY LEVELS...PARTLY TO MOSTLY SUNNY SKIES...AND TEMPERATURES TOPPING OUT IN THE MID 70S ARE AGAIN ON THE DOCKET FOR TODAY AND THURSDAY. THE ONLY DRAW BACK MAY BE THE PREVALENCE OF MID RANGE CLOUDS SLIPPING SOUTH INTO OUR AREA FROM BENEATH THE UPPER LOW. TONIGHT WILL FEATURE ANOTHER RELATIVELY COOL ONE WITH LESS CLOUDS ANTICIPATED TO SLOW THE TEMPERATURE/S DESCENT. AS SUCH...RIDGE TO VALLEY TEMPERATURE DIFFERENCES WILL PLAY OUT THROUGH THE NIGHT ALONG WITH THE FORMATION OF RIVER VALLEY FOG TOWARDS DAWN THURSDAY. ONCE AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS THROUGH THE EVENING BEFORE INITIATING WITH THE SUPERBLEND THROUGH THE DAY THURSDAY. DID MAKE SOME SIGNIFICANT ADJUSTMENT TO LOWS TONIGHT FOR RIDGE AND VALLEY TERRAIN EFFECTS. AS FOR POPS...KEPT THEM EITHER ZERO OR IN THE LOW SINGLE DIGITS THROUGH THE PERIOD...IN LINE WITH ALL MOS GUIDANCE. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 340 AM EDT WED AUG 26 2015 AT UPPER LEVELS...A STRONG MID LEVEL RIDGE DEVELOPS OVER THE WESTERN CONUS WITH A RIDGE AXIS EXTENDING NEWD INTO THE UPPER MIDWEST. EMBEDDED WITHIN THIS FLOW...A SHORTWAVE TROUGH DEVELOPS AND TRAVERSES THE RIDGE TOWARDS THE MID MS VALLEY REGION BY SATURDAY AFTERNOON. MEANWHILE...A SFC LOW DEVELOPS IN THE GULF AND MOVES NWD...GETTING INGESTED INTO THE SHORTWAVE TROUGH AS IT CROSSES THROUGH THE OHIO VALLEY...ULTIMATELY STRENGTHENING THE TROUGH. THERE ARE MODEL DIFFERENCES WITH HOW THIS SITUATION EVOLVES...WITH THE GFS BEING THE MORE AGGRESSIVE OF THE TWO MODELS. IN TERMS OF SENSIBLE WEATHER...FRIDAY WILL BE ANOTHER BEAUTIFUL AND DRY DAY BEFORE MOISTURE AND HUMIDITY RETURNS ON SATURDAY. TEMPERATURES WILL BEGIN JUST BELOW NORMAL ON FRIDAY BUT THEN GRADUALLY WARM AND RETURN BACK TO THE MID 80S BY MONDAY. THERE WILL BE CHANCES FOR AFTERNOON SHOWERS AND A FEW THUNDERSTORMS SATURDAY THROUGH WEDNESDAY...WITH THE BEST CHANCES ON SUNDAY AFTERNOON WITH THE PASSAGE OF THE UPPER LEVEL SHORTWAVE. THOUGH ONE THING TO NOTE IS THE LACK OF MOISTURE IN THE MODEL SOUNDINGS THROUGH THE EXTENDED PERIOD. EVEN ON SUNDAY...THE UPPER LEVELS ARE SATURATED BUT THE LOW LEVELS REMAIN FAIRLY DRY. THEREFORE HAVE MAINTAINED MAINLY SLIGHT CHANCE POPS THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 230 AM EDT WED AUG 26 2015 VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 TO 36 HOURS FOR MOST OF EASTERN KENTUCKY. THE EXCEPTION WILL BE SOME RIVER VALLEY FOG TOWARD DAWN. THIS SHOULD NOT IMPACT MOST OF THE TAF SITES...WITH THE BEST SHOT BEING KSME. FOR THIS...HAVE INCLUDED A BRIEF PERIOD OF IFR VIS AND LOW CIGS TOWARD DAWN BEFORE QUICKLY DISSIPATING. WINDS WILL BE LIGHT AND VARIABLE THROUGH THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...JVM AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
640 PM EDT WED AUG 26 2015 .SYNOPSIS... AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL APPROACH TONIGHT AND MOVE OVER THE REGION ON THURSDAY. THE TROUGH WILL LIFT NORTHEAST OF THE AREA THURSDAY NIGHT. HIGH PRESSURE WILL BUILD ALONG THE MID ATLANTIC COAST FRIDAY INTO SATURDAY. && .NEAR TERM /THROUGH THURSDAY/... 615 PM UPDATE: LATEST RADAR REF SHOWS A ROUND OF CNVCTN WEAKENING AS IT MOVES FROM WRN ME INTO E CNTRL ME. LAPS SHOWS MUCH LESS AVBL SBCAPE OVR OUR FA COMPARED TO WFO GYX`S AREA...SO THIS TREND MATCHES THE ENVIRONMENTAL SET-UP. SO THE ONLY OTHER CONCERN ATTM IS WHETHER ANY ADDITIONAL HVY SHWR/TSTM ACTIVITY MOVES ACROSS CNTRL WASHINGTON COUNTY...WHERE THERE WAS FLASH FLOODING EARLY THIS MORN...LATER TNGT BEFORE WHAT LEFT OF THE FRONT OVR THE FA MOVES E OF THE FA. LATEST HRRR MODEL OUTPUT SUGGESTS ADDITIONAL CNVCTN OVR THIS PTN OF THE FA PRIOR TO 06Z...BUT OTHER SYNOPTIC SCALE MODELS LIKE THE GFS AND ECMWF SUGGEST ADDITIONAL ACTIVITY MAY MOVE SW TO NE INTO NB PROV JUST E OF WASHINGTON COUNTY... SO WE WILL WAIT AND SEE. MEANWHILE...FCST HRLY TEMPS FOR THE OVRNGT WERE UPDATED FROM OBSVD HI TEMPS EARLIER THIS AFTN THRU OBSVD 6 PM TEMPS TO UNCHGD FCST LOWS POSTED AT 6 AM THU. LASTLY...HI TRRN RESOLUTION TEMPS WERE RETURNED FROM THIS AFTN THRU THU. ORGNL DISC: SFC BNDRY HAS SLOWLY CREEPED INTO EXTRM WRN PART OF CWA WITH NW WIND AT GREENVILLE AND SE WIND AT MILLINOCKET. THIS BNDRY IS ALLOWING MOISTURE TO STREAM NWRD ON 30KT H8 LLJ. SHOWERS AND ISOLD STORMS CONTINUE TO RE-DEVELOP AT THIS TIME. EXPECT THESE WL CONTINUE OFF AND ON INTO THE EVNG HRS. BIGGEST CONCERN CONTS TO CENTER ARND WASHINGTON CNTY. THIS AREA WAS HIT HARD THIS MRNG WITH HVY RAIN AND FLOODING AS A RESULT OF LFQ OF H2 JET. MED RANGE MODELS INDICATING ANOTHER JET DVLPNG LATE TONIGHT. THIS JET IS BEING PICKED UP ON WV IMAGERY AT THIS TIME ALONG THE ERN SEABOARD. AS THIS JET INTENSIFIES IT WL LKLY INDUCE SFC LOW DVLPMNT IN THE GULF OF MAINE. UPR LVL SUPPORT FM JET MAX COUPLED WITH LOW-LVL CONVERGENCE WITH SFC LOW AND PW VALUES OF 1.50+ INCHES WL LKLY LEAD TO HVY RAINFALL AGAIN OVRNGT. WL HIGHLIGHT THREAT IN HWO AND ALLOW LATER SHIFTS TO MAKE THE CALL ON A POSSIBLE WATCH. SFC LOPRES WL RESULT IN SLOW MVMNT TO FRONT AND NOT CLR CWA UNTIL 12Z THUR. ELEVATED INSTABILITY WL WANE ACRS MOST OF CWA AFT 00Z BUT WL CONTINUE THRU ABOUT 06Z OVR WASHINGTON CNTY. THUS HV MAINTAINED ISOLD THUNDER THRU THIS TIME. DRY DWPTS WL FILTER INTO THE NW IN WAKE OF FROPA AS DWPTS ACRS CANADA HV DROPPED INTO THE M50S. THUS, EXPECT THAT MINS OVRNGT IN THE NORTH WOOD CUD DROP INTO THE M/U 50S WITH LOCALES ALONG THE COAST IN THE L60S. DRG THE DAY THURSDAY EXPECT UPR LVL TROF TO SWING THRU THE STATE. THIS WL LEAD TO ANOTHER ROUND OF SHOWERS AND ISOLD THUNDER ACRS THE CROWN OF MAINE. COLD TEMPS ALOFT WL MV THRU DRG THE AFTN AT TIME OF MAX DIURNAL HTG. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... THE TROUGH OF LOW PRESSURE WHICH HAS BEEN BRINGING SHOWERS THE LAST FEW DAYS WILL BE WEAKENING AND LIFTING OUT TO THE NORTHEAST THURSDAY NIGHT AS HIGH PRESSURE BEGINS TO BUILD TOWARD THE MID ATLANTIC REGION. THE HIGH WILL BRING MOSTLY SUNNY AND DRY WEATHER ON FRIDAY. A WEAK FRONTAL BOUNDARY DROPPING DOWN FROM THE NORTH MAY BRING SOME CLOUDINESS TO FAR NORTHERN AREAS LATE IN THE DAY. FRIDAY NIGHT WILL BE CLEAR TO PARTLY CLOUDY. SATURDAY SHOULD THEN BE ANOTHER DRY DAY AS HIGH PRESSURE MOVES OFF THE EAST COAST. SOME CLOUDS MAY INCREASE LATE IN THE DAY AHEAD OF A WEAK TROUGH APPROACHING FROM THE WEST. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... THE WEAK TROUGH MOVING ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY WILL BRING A PARTLY TO MOSTLY CLOUDY DAY WITH THE CHANCE FOR SOME SPOTTY SHOWERS OR A THUNDERSTORM, ESPECIALLY OVER THE NORTH WHERE A WEAK FRONTAL BOUNDARY WILL BE PUSHING IN. THE TROUGH WILL QUICKLY MOVE AWAY SUNDAY NIGHT. HIGH PRESSURE SUPPORTED BY STRONG UPPER LEVEL RIDGING SHOULD THEN BUILD OVER THE AREA BRINGING SUNNY DRY WEATHER ON MONDAY. RIDGING WILL CONTINUE TO SUPPORT SUNSHINE AND DRY WEATHER ON TUESDAY WITH TEMPS A BIT WARMER AS A WEST SOUTHWESTERLY BREEZE CIRCULATES IN BEHIND THE HIGH. DRY WEATHER SHOULD PERSIST INTO MID WEEK DOWNEAST WHILE A WEAK FRONTAL BOUNDARY PUSHING INTO THE NORTH WILL BRING A CHANCE FOR SHOWERS OVER NORTHERN AREAS ON WEDNESDAY. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... NEAR TERM: IFR CONDITIONS EXPECTED MAJORITY OF TAF VALID TIME IN MOIST AND HUMID AIRMASS. EXPECT HEAVY SHOWERS AT MOST TERMINALS THOUGH -TSRA IS POSSIBLE AT HUL THROUGH 20Z THIS AFTERNOON. AS DRIER AIR WORKS IN BEHIND FRONTAL BOUNDARY TONIGHT EXPECTED CONDITIONS TO INCREASE TO MVFR AFTER DAYBREAK. SHORT TERM: VFR CONDITIONS ARE EXPECTED THURSDAY NIGHT THROUGH SATURDAY AS HIGH PRESSURE BUILDS SOUTH OF THE AREA. CONDITIONS MAY LOWER TO MVFR AT TIMES SATURDAY NIGHT INTO SUNDAY WITH CLOUDS AND SOME SHOWERS. CONDITIONS WILL RETURN TO VFR SUNDAY NIGHT AND REMAIN VFR ON MONDAY AS HIGH PRESSURE RETURNS. && .MARINE... NEAR TERM: VISIBILITIES WILL BE REDUCED IN AREAS OF FOG ONCE AGAIN TONIGHT. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TONIGHT. SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THROUGH MID WEEK NEXT WEEK WITH HIGH PRESSURE SOUTH OF THE WATERS EARLY THIS WEEKEND AND ANOTHER HIGH OVER THE WATERS EARLY NEXT WEEK. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...VJN SHORT TERM...BLOOMER LONG TERM...BLOOMER AVIATION...VJN/BLOOMER MARINE...VJN/BLOOMER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EDT WED AUG 26 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY APPROACH LATE TONIGHT...THEN CROSS THE REGION LATER WEDNESDAY. HIGH PRESSURE WILL BUILD ACROSS THE REGION LATER THURSDAY INTO FRIDAY. && .NEAR TERM /THROUGH TODAY/... UPDATE: ADJUSTED POPS BASED ON LATEST RADAR REFLECTIVITY IMAGERY. USED HRRR POPS FOR THE OVERNIGHT HOURS WHICH SEEMED TO BE HANDLING THINGS PRETTY WELL THIS HOUR. WILL CONTINUE TO MENTION HEAVY DOWNPOURS IN ANY SHOWERS AND TSTMS OVERNIGHT WITH PWATS RUNNING 1.5 TO 2.0 INCHES. ONLY OTHER CHANGES WERE SOME MINOR TWEAKS TO TEMPS/DEW POINTS. OTHERWISE...FCST HRLY TEMPS WERE UPDATED FROM OBSVD 9 PM TEMPS...TO FCST LOWS POSTED AT 6 AM WED WHICH WERE LOWERED SLIGHTLY OVR THE NW GIVEN SLIGHTLY NEGATIVE TRENDS FROM THE PRIOR FCST TEMPS AT THIS HR OVR THE NW. LASTLY...WE INCORPORATED MORE HI TRRN DAY/NGT TEMP DIURNAL VARIATION THRU WED. ORGNL DISC: A SLOW MOVING COLD FRONT WILL APPROACH FROM THE WEST TONIGHT...THEN BEGIN TO CROSS THE REGION WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS THE REGION TONIGHT THROUGH WEDNESDAY IN ADVANCE OF THE FRONT. WITH ABUNDANT LOW LEVEL MOISTURE...LOCALLY HEAVY RAINS COULD OCCUR WITH ANY THUNDERSTORMS OR HEAVIER SHOWERS EARLY TONIGHT. FOG WILL ALSO MOVE INLAND FROM THE GULF OF MAINE TONIGHT...MOST EXTENSIVE ACROSS DOWNEAST AREAS. OVERNIGHT LOW TEMPERATURES WILL RANGE FROM THE LOWER TO MID 60S ACROSS THE REGION. HIGH TEMPERATURES WEDNESDAY WILL GENERALLY RANGE FROM THE LOWER TO MID 70S ACROSS THE FORECAST AREA. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... FOR WEDNESDAY NIGHT...THE COLD FRONT WILL SLOWLY EXIT THE EASTERN PORTION OF THE FORECAST AREA LATER IN THE EVENING. SHOWERS AND THUNDERSTORMS WILL END AS THE FRONT EXITS THE AREA. FURTHER WEST...TOWARDS BANGOR AND GREENVILLE....SHOWERS WILL END EARLY THE EVENING. MARGINALLY DRIER AND SLIGHTLY COOLER AIR WILL ADVECT INTO THE REGION LATER IN THE NIGHT AND PUSH THE STRATUS CLOUDS OUT OF THE AREA. HOWEVER...IT WILL STILL BE ANOTHER HUMID NIGHT WITH DEWPOINTS ABOVE 60F MOST OF THE NIGHT AND COASTAL FOG WILL PROBABLY LINGER THROUGH THE NIGHT. LOWS WILL STILL BE IN THE UPPER 50S TO NEAR 60F. A POST-FRONTAL SURFACE TROUGH ON THURSDAY AFTERNOON WILL FINALLY BRING IN SIGNIFICANTLY LESS HUMID AIR FOR THE FIRST TIME IN NEARLY TWO WEEKS. THIS SURFACE TROUGH WILL COINCIDE WITH THE PASSAGE OF AN UPPER LEVEL TROUGH AND SET OFF SHOWERS THURSDAY AFTERNOON WITH MODEST AMOUNTS OF CAPE BUT FAR LESS PRECIPITABLE WATER. AS A RESULT...IT IS HARD TO FORESEE MUCH MORE THAN A TENTH OF AN INCH OF RAINFALL WITH THESE SHOWERS.. AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT. HIGHS ON THURSDAY WILL RANGE FROM THE LOWER 70S NORTH TO MID-UPPER 70S FOR BANGOR AND DOWN EAST. THE OFFSHORE FLOW WILL ENSURE THAT THE WARMEST TEMPERATURES ARE TOWARDS THE COAST. THE COOLER AIR WILL BE IN PLACE THURSDAY NIGHT UNDER HIGH PRESSURE. LOWS WILL DROP TO THE UPPER 40S IN THE ALLAGASH WHILE LOW TO MID 50S ARE ANTICIPATED ELSEWHERE. THE HIGH REMAINS IN PLACE FOR FRIDAY. HIGHS ON FRIDAY WILL BE IN THE LOW TO MID 70S WITH LOW HUMIDITY. AGAIN...THE OFFSHORE FLOW WILL PRODUCE HIGHER TEMPERATURES TOWARDS THE COAST. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A RIDGE OF HIGH PRESSURE WILL BE LOCATED ALONG THE EAST COAST FRIDAY NIGHT AS A WEAK TROUGH IN EASTERN CANADA PUSHES A WEAKENING COLD FRONT THROUGH OUR AREA. THIS WILL BRING A PARTLY CLOUDY NIGHT FRIDAY NIGHT. THE FRONT WILL PUSH BACK NORTH AS A WARM FRONT ON SATURDAY AS MOISTURE LIFTS NORTH BEHIND THE HIGH WHICH WILL BE MOVING OUT INTO THE ATLANTIC. THE MOISTURE WILL BRING INCREASING CLOUDS SATURDAY AND SOME SHOWERS ARE POSSIBLE OVER THE NORTH SATURDAY AFTERNOON. A WEATHER DISTURBANCE MAY BRING SHOWERS THROUGHOUT THE AREA SATURDAY NIGHT INTO SUNDAY. DRY WEATHER SHOULD THEN RETURN MONDAY INTO TUESDAY AS HIGH PRESSURE BUILDS BACK INTO THE EAST ALONG WITH SOME UPPER LEVEL RIDGING. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: VARIABLE CONDITIONS WILL OCCUR ACROSS THE REGION THIS EVENING RANGING FROM VFR TO LIFR. IFR TO VLIFR CONDITIONS ARE THEN EXPECTED ACROSS THE FORECAST AREA OVERNIGHT INTO EARLY WEDNESDAY. GENERALLY EXPECT MVFR TO LIFR CONDITIONS ACROSS THE REGION LATER WEDNESDAY MORNING THROUGH THE AFTERNOON. SHORT TERM: EXPECT PREDOMINATELY IFR CONDITIONS WEDNESDAY NIGHT WITH THUNDERSTORMS POSSIBLE IN THE EVENING. LIFR IS LIKELY TOWARDS BHB AND THE COAST WEDNESDAY NIGHT IN FOG. CONDITIONS WILL BECOME VFR THURSDAY THROUGH FRIDAY FOR ALL TERMINALS. VFR CONDITIONS ARE EXPECTED EARLY SATURDAY. CONDITIONS MAY LOWER TO MVFR ACROSS THE NORTH SATURDAY AFTERNOON. && .MARINE... NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS TONIGHT THROUGH WEDNESDAY. VISIBILITIES WILL BE REDUCED IN FOG TONIGHT THROUGH WEDNESDAY...ALONG WITH SHOWERS AND THUNDERSTORMS. SHORT TERM: FOG CONTINUES UNTIL THURSDAY MORNING. LOWER PERIOD SE SWELL NEAR 4 FT IS EXPECTED WEDNESDAY NIGHT INTO THURSDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...DUDA SHORT TERM...MCW LONG TERM...BLOOMER AVIATION...DUDA/MCW MARINE...DUDA/MCW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
454 PM EDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 350 PM EDT WED AUG 26 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THAT THE MID LEVEL LOW THAT HAS PLAGUED UPPER MI FOR THE LAST 2 DAYS WITH UNSEASONABLY COOL WEATHER IS NOW CENTERED SE OF JAMES BAY AND IS CONTINUING TO DRIFT E. UPSTREAM...A RIDGE EXTENDS FROM THE SRN ROCKIES INTO SASKATCHEWAN/MANITOBA/NRN ONTARIO. VIS SATELLITE IMAGERY SHOWS THE BACK EDGE OF THE LOW CLOUDS ASSOCIATED WITH LOW AND DEPARTING THERMAL TROF RUNNING FROM ROUGHLY COPPER HARBOR TO MARQUETTE TO IRON MTN. TO THE W...ELEVATED SMOKE LAYER FROM THE PACIFIC NW FOREST FIRES IS ONCE AGAIN SPREADING ACROSS THE NRN PLAINS WITH LEADING EDGE APPROACHING WRN LAKE SUPERIOR/FAR NW WI. SHORT TERM PORTION OF THE FCST WILL BE QUIET AS SFC HIGH PRES RIDGE MOVES ACROSS THE UPPER LAKES TONIGHT AND CONTINUES TO DRIFT EASTWARD ON THU. MAIN FCST ISSUES WILL REVOLVE AROUND CLOUDS/TEMPS AND FROST/FOG POTENTIAL TONIGHT. EXPECT CLOUDS TO CONTINUE CLEARING OUT FROM NW TO SE OVER THE NEXT SEVERAL HRS. HOWEVER...THERE IS CERTAINLY CONCERN THAT CLEARING MAY NOT PROGRESS FAR ENOUGH SE BEFORE LOW-LEVEL WINDS VEER AND EITHER HOLD CLOUDS IN OVER THE E OR BRING THEM BACK. FOR NOW...THE PLAN IS FOR DAYTIME HEATING TO CONTINUE MIXING OUT THE MOISTURE FROM THE W AND AID THE CURRENT SE CLEARING TREND...HELPING IT PROGRESS FAR ENOUGH THAT CLOUDS WILL STAY E OF THE FCST AREA TONIGHT. IF CLOUDS DO NOT CLEAR OUT OF THE ERN FCST AREA BY SUNSET...SKIES PROBABLY WON`T CLEAR TONIGHT. OTHERWISE...AS SFC HIGH PRES SLOWLY MOVES ACROSS THE FCST AREA TONIGHT...STAGE WILL BE SET FOR A COOL NIGHT UNDER CLEAR SKIES/CALM WIND AND DRY AIR MASS WITH PRECIPITABLE AROUND ONE-HALF INCH. LEANED FCST SIGNIFICANTLY TOWARD BOTH BIAS CORRECTED CANADIAN MODELS FOR MINS DUE TO THEIR USUAL BETTER PERFORMANCE IN RADIATIONAL COOLING SITUATIONS. EXPECT THE NORMAL COLD AREAS IN THE INTERIOR TO FALL INTO THE UPPER 30S WITH TRADITIONAL COLD SPOTS DOWN INTO THE MID 30S. WILL INCLUDE PATCHY FROST IN THE FCST. TYPICAL FOR THIS TIME OF YEAR UNDER RADIATIONAL COOLING CONDITIONS...EXPECT SOME FOG TO DEVELOP AS WELL NEAR RIVERS/STREAMS/LAKES/SWAMPY AREAS. RETURN FLOW WILL BEGIN ON THU AS THE SFC HIGH PRES RIDGE CONTINUES TO DRIFT E. WITH LINGERING DRY AIR MASS...EXPECT ONLY SOME HIGH CLOUDS...THOUGH SKY WILL LIKELY BE HAZY WITH ELEVATED SMOKE LAYER OVER THE UPPER LAKES. WITH MORNING 850MB TEMPS OF 10-12C AND RISING 1-2C DURING THE DAY...EXPECT AFTN MAX TEMPS MOSTLY IN THE LOWER TO MIDDLE 70S AWAY FROM ANY LAKE MODERATION. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 453 PM EDT WED AUG 26 2015 THE MODELS WERE IN OVERALL AGREEMENT WITH THE PATTERN TRANSITION FROM ZONAL FLOW TO A MORE AMPLIFIED PATTERN NEXT WEEK WITH A TROUGH OVER THE NW CONUS AND A RIDGE OVER THE CNTRL AND EAST. THURSDAY NIGHT...AS THE SFC RIDGE SLIDES OFF TO THE EAST AND 850-700 MB WAA DEVELOPS...EXPECT SOME INCREASE IN MID CLOUDS ACROSS UPPER MICHIGAN. THIS SHOULD HELP KEEP OVERNIGHT LOWS IN THE MID 50S INLAND TO AROUND 60 NEAR LAKE SUPERIOR WHERE DOWNSLOPE FLOW PREVAILS. FRI THROUGH SAT...THERE IS STILL PLENTY OF UNCERTAINTY WITH THE PATH/TIMING OF THE SHORTWAVE EMERGING FROM THE PLAINS. THE GFS...GEM AND ESPECIALLY THE ECMWF HAVE TRENDED FARTHER NORTH WITH THE SYSTEM WHICH COULD REMAIN JUST SOUTH OF THE CWA OR BRING RAIN TO MOST OF THE AREA. THE FCST REFLECTS THESE TRENDS AND REMAINING UNCERTAINTY WITH INCREASING POPS THAT REMAIN IN THE CHANCE CATEGORY. THE BEST CHANCE FOR RAIN WOULD ARRIVE MAINLY FRI NIGHT AND LINGER OVER THE ERN CWA AT LEAST THROUGH SAT MORNING. THERE MAY ENOUGH HEATING/INSTABILITY FRI FOR AT LEAST A MENTION OF TSRA...BUT MOST OF THE PCPN ASSOCIATED WITH THE SHRTWV WILL NOT HAVE TS...PER GFS/ECMWF INSTABILITY PROGS. SAT NIGHT THROUGH WED...THE BUILDING RIDGE WILL BRING WARMER CONDITIONS WITH MAINLY DRY CONDITIONS. EXPECT THE FRONTAL BOUNDARY TO REMAIN FAR ENOUGH WEST TO MINIMIZE SHRA/TSRA CHANCES. HIGHS WILL CLIMB WELL ABOVE NORMAL WITH HIGHS WELL INTO THE 80S FROM MON THROUGH WED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 143 PM EDT WED AUG 26 2015 HIGH PRES AND DRIER AIR BUILDING INTO THE UPPER GREAT LAKES WILL RESULT IN CLEARING SKIES THIS AFTN. KIWD HAS ALREADY CLEARED OUT...AND VFR CONDITIONS/LIGHT WINDS WILL PREVAIL THERE THRU THIS FCST PERIOD. AT KCMX/KSAW...MVFR CIGS WILL CLEAR OUT IN THE NEXT COUPLE OF HRS...LEAVING VFR CONDITIONS TO PREVAIL FOR THE REMAINDER OF THE FCST PERIOD. HOWEVER...CONDITIONS TONIGHT WILL BE CONDUCIVE FOR SHALLOW RADIATION FOG DEVELOPMENT. FOG COULD AFFECT ANY OF THE TERMINALS...BUT FOR NOW...INCLUDED MVFR VIS LATE TONIGHT ONLY AT KSAW WITH CONDITIONS MORE FAVORABLE AT THAT TERMINAL. ITS QUITE POSSIBLE THAT IFR OR LIFR CONDITIONS WILL BE THE RESULT IF FOG DOES DEVELOP AT ANY OF THE TERMINALS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 350 PM EDT WED AUG 26 2015 WITH SFC HIGH PRES OVER THE UPPER GREAT LAKES...WINDS WILL BE LESS THAN 15KT ACROSS LAKE SUPERIOR TONIGHT. ALTHOUGH THE HIGH DRIFTS E ON THU...WINDS WILL REMAIN UNDER 15KT THOUGH LOCALLY SLIGHTLY HIGHER E TO SE WINDS ARE POSSIBLE IN THE AFTN IN THE VCNTY OF THE HURON ISLANDS. WINDS SHOULD REMAIN UNDER 20KT THRU THE WEEKEND...BUT THERE MAY BE SOME PERIODS WHERE WIND GUSTS EXCEED 20KT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLB AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
351 PM EDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 350 PM EDT WED AUG 26 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THAT THE MID LEVEL LOW THAT HAS PLAGUED UPPER MI FOR THE LAST 2 DAYS WITH UNSEASONABLY COOL WEATHER IS NOW CENTERED SE OF JAMES BAY AND IS CONTINUING TO DRIFT E. UPSTREAM...A RIDGE EXTENDS FROM THE SRN ROCKIES INTO SASKATCHEWAN/MANITOBA/NRN ONTARIO. VIS SATELLITE IMAGERY SHOWS THE BACK EDGE OF THE LOW CLOUDS ASSOCIATED WITH LOW AND DEPARTING THERMAL TROF RUNNING FROM ROUGHLY COPPER HARBOR TO MARQUETTE TO IRON MTN. TO THE W...ELEVATED SMOKE LAYER FROM THE PACIFIC NW FOREST FIRES IS ONCE AGAIN SPREADING ACROSS THE NRN PLAINS WITH LEADING EDGE APPROACHING WRN LAKE SUPERIOR/FAR NW WI. SHORT TERM PORTION OF THE FCST WILL BE QUIET AS SFC HIGH PRES RIDGE MOVES ACROSS THE UPPER LAKES TONIGHT AND CONTINUES TO DRIFT EASTWARD ON THU. MAIN FCST ISSUES WILL REVOLVE AROUND CLOUDS/TEMPS AND FROST/FOG POTENTIAL TONIGHT. EXPECT CLOUDS TO CONTINUE CLEARING OUT FROM NW TO SE OVER THE NEXT SEVERAL HRS. HOWEVER...THERE IS CERTAINLY CONCERN THAT CLEARING MAY NOT PROGRESS FAR ENOUGH SE BEFORE LOW-LEVEL WINDS VEER AND EITHER HOLD CLOUDS IN OVER THE E OR BRING THEM BACK. FOR NOW...THE PLAN IS FOR DAYTIME HEATING TO CONTINUE MIXING OUT THE MOISTURE FROM THE W AND AID THE CURRENT SE CLEARING TREND...HELPING IT PROGRESS FAR ENOUGH THAT CLOUDS WILL STAY E OF THE FCST AREA TONIGHT. IF CLOUDS DO NOT CLEAR OUT OF THE ERN FCST AREA BY SUNSET...SKIES PROBABLY WON`T CLEAR TONIGHT. OTHERWISE...AS SFC HIGH PRES SLOWLY MOVES ACROSS THE FCST AREA TONIGHT...STAGE WILL BE SET FOR A COOL NIGHT UNDER CLEAR SKIES/CALM WIND AND DRY AIR MASS WITH PRECIPITABLE AROUND ONE-HALF INCH. LEANED FCST SIGNIFICANTLY TOWARD BOTH BIAS CORRECTED CANADIAN MODELS FOR MINS DUE TO THEIR USUAL BETTER PERFORMANCE IN RADIATIONAL COOLING SITUATIONS. EXPECT THE NORMAL COLD AREAS IN THE INTERIOR TO FALL INTO THE UPPER 30S WITH TRADITIONAL COLD SPOTS DOWN INTO THE MID 30S. WILL INCLUDE PATCHY FROST IN THE FCST. TYPICAL FOR THIS TIME OF YEAR UNDER RADIATIONAL COOLING CONDITIONS...EXPECT SOME FOG TO DEVELOP AS WELL NEAR RIVERS/STREAMS/LAKES/SWAMPY AREAS. RETURN FLOW WILL BEGIN ON THU AS THE SFC HIGH PRES RIDGE CONTINUES TO DRIFT E. WITH LINGERING DRY AIR MASS...EXPECT ONLY SOME HIGH CLOUDS...THOUGH SKY WILL LIKELY BE HAZY WITH ELEVATED SMOKE LAYER OVER THE UPPER LAKES. WITH MORNING 850MB TEMPS OF 10-12C AND RISING 1-2C DURING THE DAY...EXPECT AFTN MAX TEMPS MOSTLY IN THE LOWER TO MIDDLE 70S AWAY FROM ANY LAKE MODERATION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 336 AM EDT WED AUG 26 2015 AFTER A PERIOD OF VERY COOL WX...LOOKS LIKE A RETURN OF MORE SEASONABLE WX TO END THE WEEK. ALTHOUGH THERE MAY BE SOME SHOWERS LATE THU NGT INTO SAT...PCPN CHCS APPEAR LIMITED BY THE PLACEMENT OF UPR MI BTWN DISTURBANCES PASSING TO THE N AND S OF THE UPR LKS. A RETURN OF SUMMER-LIKE WX APPEARS ON TAP NEXT WEEK AS AN UPR RDG IS FCST TO BUILD OVER THE GREAT LKS DOWNSTREAM OF A DEEPENING TROF ACROSS THE W. THU...EXPECT A MOSUNNY AND WARMER DAY ON THU WITH HI PRES/ACYC SW FLOW/DRY AIRMASS DOMINATING. H85 TEMPS REBOUNDING TO 12-14C BY LATE IN THE DAY WL SUPPORT MAX TEMPS RISING WELL INTO THE 70S OVER MOST OF THE CWA AWAY FM LK MI MODERATION. THU NGT...UPR MI IS FCST TO BE SITUATED BTWN FAST WNW FLOW OVER SRN CANADA AND A WEAKER SRN STREAM OVER THE CENTRAL CONUS. A DISTURBANCE IN THE NRN STREAM IS FCST TO SLIDE ESEWD THRU ONTARIO DURING THE NGT WITH ATTENDANT COLD FNT APRCHG NW LK SUP LATE. AT THE SAME TIME...A SHRTWV IN THE SRN BRANCH WL BE DRIFTING SLOWLY ESEWD THRU THE MID/ UPR MS RIVER VALLEY. ALTHOUGH THE 12Z ECMWF GENERATED SOME SPOTTY LGT PCPN OVER THE NW HALF OF UPR MI LATE AT NGT WITH THE RETURN OF SOME HIER H85 THETA E AIR IN THE WLY FLOW TO THE S OF DISTURBANCE PASSING THRU ONTARIO...AXIS OF WEAK FORCING/LINGERING LLVL ACYC FLOW OVER UPR MI BTWN AREAS OF SHARPER DYNAMIC FORCING/CYC FLOW PASSING TO THE S AND THE N AS WELL AS NOCTURNAL COOLING FAVOR THE DRIER MODELS. SO CUT POPS TO NO HIER THAN LO CHC NEAR ISLE ROYALE CLOSER TO APRCHG COLD FNT. FRI THRU SAT...RECENT MODEL GUIDANCE HAS SHOWN SOME UNCERTAINTY ON HOW FAR S COLD FNT ASSOCIATED WITH EXITING NRN BRANCH SHRTWV WL REACH/BECOME STNRY AND ALSO ON TRACK OF SRN BRANCH DISTURBANCE/NRN EDGE OF ACCOMPANYING PCPN SHIELD. GIVEN THE BLDG UPR RDG IN THE PLAINS THAT WL FAVOR A MORE WNW FLOW ALOFT OVER THE UPR LKS... SUSPECT THE 00Z ECMWF/18Z GFS SHOWING A FARTHER N PCPN AREA ARE OFF THE MARK AND THAT THE FARTHER S TRACK OF THE SRN BRANCH DISTURBANCE IS CORRECT WITH ACCOMPANYING PCPN REMAINING TO THE S OF UPR MI. SEEMS THE BEST CHC FOR PCPN WL BE IF ANOTHER SHRTWV IN THE NRN BRANCH FLOW OVER SCENTRAL CANADA DRIFTS CLOSE ENUF TO THE STNRY FNT ALIGNED W-E SOMEWHERE IN THE UPR LKS TO TRIGGER SOME SHOWERS/PERHAPS A TS OVER UPR MI. SINCE THE BULK OF THE MODELS SHOW THE SFC FNT POSITIONED TO THE N OF THE CWA WITH LINGERING AXIS OF LLVL ACYC FLOW OVER UPR MI...TENDED TO GO NO HIER THAN LO CHC POPS. WITH H85 TEMPS WITHIN A FEW DEGREES OF 14C...EXPECT TEMPS TO AVG A BIT ABOVE NORMAL. SAT NGT THRU TUE...BLDG UPR RDG DOWNSTREAM OF AMPLIFYING TROF OVER WRN NAMERICA IS FCST TO DOMINATE THE GREAT LKS...BRINGING A PERIOD OF DRY AND WARMER WX AS A LLVL ACYC SW FLOW ARND SFC HI PRES CENTERED OVER THE MID ATLANTIC STATES PREVAILS. H85 TEMPS FCST TO REACH 16-20C ON SUN AND THEN AOA 20C ON MON WL SUPPORT MAX TEMPS WELL INTO THE 80S. ALTHOUGH SOME OF THE LONGER RANGE GUIDANCE HINTS A COLD FNT ASSOCIATED WITH A SHRTWV RIDING OVER THE UPR RDG MAY APRCH OR PASS NEXT TUE AND BRING SOME SHOWERS/TS AS EARLY AS LATE MON...WL GO NO HIER THAN LO CHC POPS GIVEN THE EXPECTED STRENGTH OF THE UPR RDG. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 143 PM EDT WED AUG 26 2015 HIGH PRES AND DRIER AIR BUILDING INTO THE UPPER GREAT LAKES WILL RESULT IN CLEARING SKIES THIS AFTN. KIWD HAS ALREADY CLEARED OUT...AND VFR CONDITIONS/LIGHT WINDS WILL PREVAIL THERE THRU THIS FCST PERIOD. AT KCMX/KSAW...MVFR CIGS WILL CLEAR OUT IN THE NEXT COUPLE OF HRS...LEAVING VFR CONDITIONS TO PREVAIL FOR THE REMAINDER OF THE FCST PERIOD. HOWEVER...CONDITIONS TONIGHT WILL BE CONDUCIVE FOR SHALLOW RADIATION FOG DEVELOPMENT. FOG COULD AFFECT ANY OF THE TERMINALS...BUT FOR NOW...INCLUDED MVFR VIS LATE TONIGHT ONLY AT KSAW WITH CONDITIONS MORE FAVORABLE AT THAT TERMINAL. ITS QUITE POSSIBLE THAT IFR OR LIFR CONDITIONS WILL BE THE RESULT IF FOG DOES DEVELOP AT ANY OF THE TERMINALS. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 350 PM EDT WED AUG 26 2015 WITH SFC HIGH PRES OVER THE UPPER GREAT LAKES...WINDS WILL BE LESS THAN 15KT ACROSS LAKE SUPERIOR TONIGHT. ALTHOUGH THE HIGH DRIFTS E ON THU...WINDS WILL REMAIN UNDER 15KT THOUGH LOCALLY SLIGHTLY HIGHER E TO SE WINDS ARE POSSIBLE IN THE AFTN IN THE VCNTY OF THE HURON ISLANDS. WINDS SHOULD REMAIN UNDER 20KT THRU THE WEEKEND...BUT THERE MAY BE SOME PERIODS WHERE WIND GUSTS EXCEED 20KT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
339 AM EDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 411 PM EDT TUE AUG 25 2015 LATEST WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP MID LEVEL LOW CENTERED N OF GEORGIAN BAY DRIFTING EASTWARD. TO THE W...A RIDGE EXTENDS FROM THE SRN ROCKIES N INTO SASKATCHEWAN/MANITOBA. IN THE LINGERING MOIST...CYCLONIC FLOW AROUND THE MID LEVEL LOW...SOME -SHRA/-DZ HAVE PERSISTED ACROSS THE FCST AREA TODAY...AIDED BY NW UPSLOPE FLOW. THERE HAS PROBABLY BEEN SOME LAKE COMPONENT TO THE PCPN AS WELL. WITH CLOUD TOPS WARMING OVER THE LAST SEVERAL HRS PER IR IMAGERY...RADAR HAS SHOWN PCPN COVERAGE/INTENSITY DIMINISHING. UNDER AN OVC CLOUD COVER...IT HAS BEEN ANOTHER UNSEASONABLY COOL DAY FOR LATE AUG. SO FAR...TEMPS HAVE ONLY RISEN TO THE LOW/MID 50S IN THE HIGHER TERRAIN AND WHERE PCPN LINGERS TO AROUND 60 OVER THE FAR SCNTRL. BACK EDGE OF THE CLOUD COVER EXTENDS ROUGHLY FROM DULUTH TO INTERNATIONAL FALLS AND NORTHWARD. AS MID LEVEL LOW AND UPSTREAM RIDGE DRIFT E...EXPECT IMPROVING CONDITIONS DURING THE SHORT TERM PORTION OF THE FCST. MAIN FCST ISSUES WILL BE TIMING THE ENDING OF PCPN AND THE CLEARING TREND. UNDER SLOW HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE AND WEAKENING CYCLONIC FLOW...LINGERING -SHRA/-DZ WILL CONTINUE TO DIMINISH TONIGHT. THIS TREND WILL BE MOST PRONOUNCED OVER THE W...WHERE THE LOW-LEVEL FLOW BECOMES MORE ANTICYCLONIC CLOSER TO APPROACHING SFC HIGH PRES SETTLING OVER MN. LINGERING LOW CLOUDS WILL LIMIT TEMP FALL TONIGHT. EXPECT THE LOWEST MINS (TOWARD THE MID 40S) OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLEARING LATE. IF THERE IS SOME CLEARING...PATCHY FOG COULD DEVELOP. A FEW -SHRA/PATCHY -DZ MAY CONTINUE TO LINGER INTO THE NCNTRL/ERN FCST AREA WED MORNING UNDER ABUNDANT LOW-LEVEL MOISTURE. WITH NEUTRAL TO VERY WEAKLY CYCLONIC LOW-LEVEL FLOW AND AIR MASS TOO WARM FOR LAKE EFFECT PROCESSES...ANY PCPN WILL BE VERY LIGHT. OTHERWISE...APPROACHING HIGH PRES WILL SETTLE OVER UPPER MI BY WED EVENING. MODELS SUGGEST CLEARING WILL ONLY SLOWLY PUSH E ACROSS THE FCST AREA AS THE HIGH ARRIVES AND THERMAL TROF DEPARTS. LARGELY UTILIZED A MODEL CONSENSUS TO CONSTRUCT THE SKY COVER AND THE W TO E CLEARING TREND ON WED. IT MAY NOT BE UNTIL TOWARD SUNSET THAT THE LAST OF THE CLOUDS CLEAR THE ERN FCST AREA. UNDER INCREASING SUNSHINE AND DEPARTURE OF THERMAL TROF...TEMPS WILL BEGIN TO REBOUND. EXPECT HIGHS AROUND 60/LWR 60S E WHERE CLOUDS LINGER LONGEST TO THE UPPER 60S TOWARD THE MI/WI BORDER. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 336 AM EDT WED AUG 26 2015 AFTER A PERIOD OF VERY COOL WX...LOOKS LIKE A RETURN OF MORE SEASONABLE WX TO END THE WEEK. ALTHOUGH THERE MAY BE SOME SHOWERS LATE THU NGT INTO SAT...PCPN CHCS APPEAR LIMITED BY THE PLACEMENT OF UPR MI BTWN DISTURBANCES PASSING TO THE N AND S OF THE UPR LKS. A RETURN OF SUMMER-LIKE WX APPEARS ON TAP NEXT WEEK AS AN UPR RDG IS FCST TO BUILD OVER THE GREAT LKS DOWNSTREAM OF A DEEPENING TROF ACROSS THE W. THU...EXPECT A MOSUNNY AND WARMER DAY ON THU WITH HI PRES/ACYC SW FLOW/DRY AIRMASS DOMINATING. H85 TEMPS REBOUNDING TO 12-14C BY LATE IN THE DAY WL SUPPORT MAX TEMPS RISING WELL INTO THE 70S OVER MOST OF THE CWA AWAY FM LK MI MODERATION. THU NGT...UPR MI IS FCST TO BE SITUATED BTWN FAST WNW FLOW OVER SRN CANADA AND A WEAKER SRN STREAM OVER THE CENTRAL CONUS. A DISTURBANCE IN THE NRN STREAM IS FCST TO SLIDE ESEWD THRU ONTARIO DURING THE NGT WITH ATTENDANT COLD FNT APRCHG NW LK SUP LATE. AT THE SAME TIME...A SHRTWV IN THE SRN BRANCH WL BE DRIFTING SLOWLY ESEWD THRU THE MID/ UPR MS RIVER VALLEY. ALTHOUGH THE 12Z ECMWF GENERATED SOME SPOTTY LGT PCPN OVER THE NW HALF OF UPR MI LATE AT NGT WITH THE RETURN OF SOME HIER H85 THETA E AIR IN THE WLY FLOW TO THE S OF DISTURBANCE PASSING THRU ONTARIO...AXIS OF WEAK FORCING/LINGERING LLVL ACYC FLOW OVER UPR MI BTWN AREAS OF SHARPER DYNAMIC FORCING/CYC FLOW PASSING TO THE S AND THE N AS WELL AS NOCTURNAL COOLING FAVOR THE DRIER MODELS. SO CUT POPS TO NO HIER THAN LO CHC NEAR ISLE ROYALE CLOSER TO APRCHG COLD FNT. FRI THRU SAT...RECENT MODEL GUIDANCE HAS SHOWN SOME UNCERTAINTY ON HOW FAR S COLD FNT ASSOCIATED WITH EXITING NRN BRANCH SHRTWV WL REACH/BECOME STNRY AND ALSO ON TRACK OF SRN BRANCH DISTURBANCE/NRN EDGE OF ACCOMPANYING PCPN SHIELD. GIVEN THE BLDG UPR RDG IN THE PLAINS THAT WL FAVOR A MORE WNW FLOW ALOFT OVER THE UPR LKS... SUSPECT THE 00Z ECMWF/18Z GFS SHOWING A FARTHER N PCPN AREA ARE OFF THE MARK AND THAT THE FARTHER S TRACK OF THE SRN BRANCH DISTURBANCE IS CORRECT WITH ACCOMPANYING PCPN REMAINING TO THE S OF UPR MI. SEEMS THE BEST CHC FOR PCPN WL BE IF ANOTHER SHRTWV IN THE NRN BRANCH FLOW OVER SCENTRAL CANADA DRIFTS CLOSE ENUF TO THE STNRY FNT ALIGNED W-E SOMEWHERE IN THE UPR LKS TO TRIGGER SOME SHOWERS/PERHAPS A TS OVER UPR MI. SINCE THE BULK OF THE MODELS SHOW THE SFC FNT POSITIONED TO THE N OF THE CWA WITH LINGERING AXIS OF LLVL ACYC FLOW OVER UPR MI...TENDED TO GO NO HIER THAN LO CHC POPS. WITH H85 TEMPS WITHIN A FEW DEGREES OF 14C...EXPECT TEMPS TO AVG A BIT ABOVE NORMAL. SAT NGT THRU TUE...BLDG UPR RDG DOWNSTREAM OF AMPLIFYING TROF OVER WRN NAMERICA IS FCST TO DOMINATE THE GREAT LKS...BRINGING A PERIOD OF DRY AND WARMER WX AS A LLVL ACYC SW FLOW ARND SFC HI PRES CENTERED OVER THE MID ATLANTIC STATES PREVAILS. H85 TEMPS FCST TO REACH 16-20C ON SUN AND THEN AOA 20C ON MON WL SUPPORT MAX TEMPS WELL INTO THE 80S. ALTHOUGH SOME OF THE LONGER RANGE GUIDANCE HINTS A COLD FNT ASSOCIATED WITH A SHRTWV RIDING OVER THE UPR RDG MAY APRCH OR PASS NEXT TUE AND BRING SOME SHOWERS/TS AS EARLY AS LATE MON...WL GO NO HIER THAN LO CHC POPS GIVEN THE EXPECTED STRENGTH OF THE UPR RDG. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 121 AM EDT WED AUG 26 2015 A CONTINUED NW FLOW OF MOIST COOL AIR AROUND LOW PRES NE OF LAKE SUPERIOR WILL ALLOW MVFR CONDITIONS TO PERSIST AT KIWD/KCMX/KSAW THRU AT LEAST THE OVERNIGHT. EXPECT PATCHY -DZ AT KSAW INTO THE MORNING HOURS...BUT SHOULDN`T REDUCE VIS BLO VFR. AS HIGH PRES CONTINUES TO BUILD INTO THE AREA TODAY...MVFR CIGS WILL SCATTER OUT AT KIWD/KCMX IN THE MORNING WHILE CLEARING WILL OCCUR LATER IN THE AFTN AT KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 PM EDT TUE AUG 25 2015 WITH LOW PRES NEAR JAMES BAY CONTINUING TO MOVE AWAY FROM THE AREA AND HIGH PRES OVER THE PLAINS APPROACHING...WINDS WILL CONTINUE TO DIMINISH ACROSS LAKE SUPERIOR FROM W TO E TONIGHT AND WED. WINDS TONIGHT WILL GENERALLY RANGE FROM 10-20KT W TO 15-30KT E. WINDS ON WED WILL DIMINISH TO UNDER 15KT W AND UNDER 20KT E BY THE END OF THE AFTN. AS THE HIGH MOVES OVER THE UPPER LAKES WED NIGHT...WINDS WILL BE UNDER 15KT ACROSS LAKE SUPERIOR. WINDS WILL BE MOSTLY UNDER 20KT THU THRU SUN. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 411 PM EDT TUE AUG 25 2015 LATEST WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP MID LEVEL LOW CENTERED N OF GEORGIAN BAY DRIFTING EASTWARD. TO THE W...A RIDGE EXTENDS FROM THE SRN ROCKIES N INTO SASKATCHEWAN/MANITOBA. IN THE LINGERING MOIST...CYCLONIC FLOW AROUND THE MID LEVEL LOW...SOME -SHRA/-DZ HAVE PERSISTED ACROSS THE FCST AREA TODAY...AIDED BY NW UPSLOPE FLOW. THERE HAS PROBABLY BEEN SOME LAKE COMPONENT TO THE PCPN AS WELL. WITH CLOUD TOPS WARMING OVER THE LAST SEVERAL HRS PER IR IMAGERY...RADAR HAS SHOWN PCPN COVERAGE/INTENSITY DIMINISHING. UNDER AN OVC CLOUD COVER...IT HAS BEEN ANOTHER UNSEASONABLY COOL DAY FOR LATE AUG. SO FAR...TEMPS HAVE ONLY RISEN TO THE LOW/MID 50S IN THE HIGHER TERRAIN AND WHERE PCPN LINGERS TO AROUND 60 OVER THE FAR SCNTRL. BACK EDGE OF THE CLOUD COVER EXTENDS ROUGHLY FROM DULUTH TO INTERNATIONAL FALLS AND NORTHWARD. AS MID LEVEL LOW AND UPSTREAM RIDGE DRIFT E...EXPECT IMPROVING CONDITIONS DURING THE SHORT TERM PORTION OF THE FCST. MAIN FCST ISSUES WILL BE TIMING THE ENDING OF PCPN AND THE CLEARING TREND. UNDER SLOW HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE AND WEAKENING CYCLONIC FLOW...LINGERING -SHRA/-DZ WILL CONTINUE TO DIMINISH TONIGHT. THIS TREND WILL BE MOST PRONOUNCED OVER THE W...WHERE THE LOW-LEVEL FLOW BECOMES MORE ANTICYCLONIC CLOSER TO APPROACHING SFC HIGH PRES SETTLING OVER MN. LINGERING LOW CLOUDS WILL LIMIT TEMP FALL TONIGHT. EXPECT THE LOWEST MINS (TOWARD THE MID 40S) OVER THE INTERIOR W...WHERE THERE COULD BE SOME PARTIAL CLEARING LATE. IF THERE IS SOME CLEARING...PATCHY FOG COULD DEVELOP. A FEW -SHRA/PATCHY -DZ MAY CONTINUE TO LINGER INTO THE NCNTRL/ERN FCST AREA WED MORNING UNDER ABUNDANT LOW-LEVEL MOISTURE. WITH NEUTRAL TO VERY WEAKLY CYCLONIC LOW-LEVEL FLOW AND AIR MASS TOO WARM FOR LAKE EFFECT PROCESSES...ANY PCPN WILL BE VERY LIGHT. OTHERWISE...APPROACHING HIGH PRES WILL SETTLE OVER UPPER MI BY WED EVENING. MODELS SUGGEST CLEARING WILL ONLY SLOWLY PUSH E ACROSS THE FCST AREA AS THE HIGH ARRIVES AND THERMAL TROF DEPARTS. LARGELY UTILIZED A MODEL CONSENSUS TO CONSTRUCT THE SKY COVER AND THE W TO E CLEARING TREND ON WED. IT MAY NOT BE UNTIL TOWARD SUNSET THAT THE LAST OF THE CLOUDS CLEAR THE ERN FCST AREA. UNDER INCREASING SUNSHINE AND DEPARTURE OF THERMAL TROF...TEMPS WILL BEGIN TO REBOUND. EXPECT HIGHS AROUND 60/LWR 60S E WHERE CLOUDS LINGER LONGEST TO THE UPPER 60S TOWARD THE MI/WI BORDER. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 301 PM EDT TUE AUG 25 2015 GOOD AGREEMENT IN OVERALL LOOK OF LARGE SCALE PATTERN INTO NEXT WEEK. UPPER TROUGHING WITH SLOW MOVING SFC LOW REORGANIZES INTO UPPER LOW OVER HUDSON BAY AND NUNAVUT CANADA BY END OF THE WEEK. EXPECT UPPER RIDGE OVER PACIFIC NORTHWEST TO THE ROCKIES EARLY THIS WEEK TO MOVE ACROSS THE PLAINS TO THE WESTERN GREAT LAKES BY THIS WEEKEND AS TROUGHING DEEPENS AND SETTLES ACROSS WESTERN CANADA AND THE PACIFIC NORTHWEST. CHANCES FOR MUCH RAINFALL IN THIS PATTERN ARE SLIM. STARTING WITH WEDNESDAY NIGHT...HIGH PRESSURE RIDGE SETTLES ACROSS THE AREA SO WINDS WILL BECOME LIGHT. THE LIGHT WINDS AND PWATS DOWN BLO 0.5 INCH SHOULD LEAD TO GOOD RADIATIONAL COOLING. LOWERED MINS INTO THE MIDDLE 30S FOR TYPICAL COLD SPOTS OVER INTERIOR. SOUNDINGS SHOW LOW-LEVEL MOISTENING AS WELL SO THERE MAY BE FOG. ALSO ADDED MENTION OF FROST FOR COLDEST SPOTS. THIS NIGHT APPEARS TO BE TAIL END OF THE FALL LIKE CONDITIONS BEFORE WARMING TREND STARTS UP ON THURSDAY. ONLY NOTABLE CHANCES OF RAIN WOULD BE LATE THURSDAY NIGHT INTO FRIDAY AS WEAK COLD FRONT MAKES BRIEF PUSH ACROSS NORTHWEST ONTARIO AND THE UPPER GREAT LAKES. LARGER SCALE SUPPORT NOT VERY STRONG FOR RAIN OVER UPR MICHIGAN AS UPPER LEVEL SHORTWAVE ENERGY IS GENERALLY DISPLACED OF UPPER LAKES WITH ONE STRONGER SHORTWAVE CROSSING WELL TO THE NORTH OVER NORTHERN MANITOBA AND NORTHERN ONTARIO AND OTHER STRONGER SHORTWAVE SLIDING FM WYOMING/NEBRASKA TO IOWA/NORTHERN ILLINOIS. RESULT IS STRONGEST Q-VECTOR CONVERGENCE/LIFT STAYING OVER NORTHERN ONTARIO AND FM SOUTHERN MINNESOTA TO WISCONSIN AND LOWER MICHIGAN. APPEARS THAT GREATEST MOISTURE INFLOW IN FORM OF H85 THETA-E ADVECTION IS INTERCEPTED BY SOUTHERN SHORTWAVE. NO HELP FM INSTABILITY WITH STRONGER MUCAPE STAYING OVER THE NORTHERN PLAINS THURSDAY NIGHT INTO FRIDAY. BETTER SIGNAL FOR CONVECTION RUNS FM SOUTHERN MINNESOTA TO SOUTHERN WISCONSIN CLOSER TO H85 MOISTURE TRANSPORT. LOWER RANGE CHANCE POPS IS ALL THAT THIS FRONTAL BOUNDARY WARRANTS ATTM FOR THURSDAY NIGHT INTO FRIDAY. WEAKNESS IN THE UPPER LEVEL FLOW...VERY WEAK TROUGHING...LINGERS OVER THE WESTERN GREAT LAKES ON SATURDAY. GFS SOUNDINGS SHOW NARROW LAYER OF LOW-LEVEL MOISTURE BUT THIS IS PROBABLY NOT ENOUGH TO SUPPORT SHOWERS. PROBABLY WILL BE SOME SORT OF ONSHORE COMPONENT TO THE WINDS OVER THE EAST HALF OF CWA CLOSER TO HIGH PRESSURE OVER MUCH OF THE GREAT LAKES. WEST HALF OF CWA SHOULD START TO SEE MORE S/SW WINDS AHEAD OF DEVELOPING TROUGHING IN THE PLAINS. H85 TEMPS COOL A FEW DEGREES COMPARED TO FRIDAY. WARMEST TEMPS ON SATURDAY IN THE LOW-MID 70S SHOULD BE OVER THE WEST WITH LESS INFLUENCE OF GREAT LAKES COOLING AND BETTER CHANCES OF SEEING SOME SUNSHINE. UPPER LEVEL RIDGING TAKES BETTER HOLD ON SUNDAY. SFC WINDS REMAIN LIGHT AS SFC RIDGE IS STILL CLOSE BY TO THE EAST. WITH H85 TEMPS WARMING TO 13-15C...SHOULD SEE READINGS MOST AREAS AT LEAST INTO THE UPPER 70S. LOWER 80S OVER THE WEST WITH LESS LAKE INFLUENCE AND WARMER TEMPS ALOFT. RIDGING ALOFT FIRMLY OVERHEAD ON MONDAY WITH GRADIENT S WIND BTWN HIGH PRESSURE OVER LOWER GREAT LAKES AND NEW ENGLAND AND A LOW PRESSURE TROUGH OVER THE NORTHERN PLAINS. H85 TEMPS VARY WILDLY THOUGH WITH THE ECMWF PUSHING BULK OF WARMTH CLOSER TO THE SFC TROUGH AND OVER NORTHERN ONTARIO /H85 TEMPS UP TO 15C OVER UPR MICHIGAN/ WHILE GFS SHOWS H85 TEMPS PUSHING PAST 22C ACROSS UPR MICHIGAN. BLEND OF GUIDANCE AND SYNOPTIC SETUP ALONE JUSTIFIES CONSENSUS TEMPS TO AT LEAST LOWER 80S. NOT A LOT OF CHANGE FOR FIRST DAY OF SEPTEMBER WITH LINGERING UPPER RIDGE AND APPROACHING SFC FRONT. GFS BRINGS FRONT THROUGH UPPER LAKES QUICKER...BUT EXPECT SLOWER IDEA FM ECMWF GIVEN THE UPPER RIDGE IT WILL BE RUNNING UP AGAINST. DRY WEATHER AND WARMING TEMPS ALOFT AHEAD OF FRONT WITH STRONGER S/SW WINDS WILL GIVE MOST AREAS AWAY FM LK MICHIGAN SHORE A GOOD CHANCE OF SEEING HIGHS INTO MIDDLE OR POSSIBLY UPPER 80S. LOWER TO MIDDLE 80S WITH ONLY SLIGHT CHANCE POPS WILL DO FOR NOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 121 AM EDT WED AUG 26 2015 A CONTINUED NW FLOW OF MOIST COOL AIR AROUND LOW PRES NE OF LAKE SUPERIOR WILL ALLOW MVFR CONDITIONS TO PERSIST AT KIWD/KCMX/KSAW THRU AT LEAST THE OVERNIGHT. EXPECT PATCHY -DZ AT KSAW INTO THE MORNING HOURS...BUT SHOULDN`T REDUCE VIS BLO VFR. AS HIGH PRES CONTINUES TO BUILD INTO THE AREA TODAY...MVFR CIGS WILL SCATTER OUT AT KIWD/KCMX IN THE MORNING WHILE CLEARING WILL OCCUR LATER IN THE AFTN AT KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 PM EDT TUE AUG 25 2015 WITH LOW PRES NEAR JAMES BAY CONTINUING TO MOVE AWAY FROM THE AREA AND HIGH PRES OVER THE PLAINS APPROACHING...WINDS WILL CONTINUE TO DIMINISH ACROSS LAKE SUPERIOR FROM W TO E TONIGHT AND WED. WINDS TONIGHT WILL GENERALLY RANGE FROM 10-20KT W TO 15-30KT E. WINDS ON WED WILL DIMINISH TO UNDER 15KT W AND UNDER 20KT E BY THE END OF THE AFTN. AS THE HIGH MOVES OVER THE UPPER LAKES WED NIGHT...WINDS WILL BE UNDER 15KT ACROSS LAKE SUPERIOR. WINDS WILL BE MOSTLY UNDER 20KT THU THRU SUN. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GLASGOW MT
858 PM MDT THU AUG 27 2015 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY... UPDATE... FEW CHANGES WERE NEEDED TO THE INHERITED FORECAST. RADAR OBSERVATIONS SUGGEST THAT A LONE SHOWER OVERNIGHT ACROSS SOUTHERN AN EASTERN AREAS CANNOT BE COMPLETELY RULED OUT...SO POPS WERE ADJUSTED ACCORDINGLY. OTHERWISE ALL IS ON TRACK. MALIAWCO PREVIOUS DISCUSSION... THE EMBEDDED SHORT-WAVE TROUGH WHICH RODE UP AND AROUND THE RIDGE OF HIGH PRESSURE HAS NOW PASSED EAST OF MONTANA. ANY REMAINING CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY THIS AFTERNOON AND EVENING WILL BE MANIFESTED BY A RESIDUAL VERY SMALL-SCALE KINK IN THE FLOW ALOFT APPROACHING FROM CENTRAL MONTANA AS THE UPPER- LEVEL RIDGE NOW BEGINS TO RE-ASSERT ITSELF ACROSS THE REGION. EVEN WITH THE TIME FRAME VERY NEAR...MODELS ARE STILL IN SIGNIFICANT DISAGREEMENT AS TO HOW MUCH PRECIPITATION WILL FALL ACROSS NE MONTANA THROUGH THIS EVENING. GFS AND HRRR ARE NEARLY COMPLETELY DRY...THE NAM SHOWS A FEW SCATTERED AREAS OF LIGHT PRECIP...AND THE EC CONTINUES TO HOLD ON TO A WIDE AREA OF WETTING RAIN ACROSS THE WESTERN HALF OF OUR CWA. BY LATE TONIGHT...IT WILL BECOME EVIDENT WHICH MODEL SOLUTION IS MORE TRUSTWORTHY IN THE NEAR SHORT TERM. REGARDLESS...EARLY FRIDAY MORNING THROUGH SATURDAY NIGHT SHOWS MUCH BETTER MODEL CONSENSUS IN KEEPING NE MONTANA DRY AS A BONE UNDER A DECENT RIDGE OF HIGH PRESSURE. INDEED...HIGH TEMPERATURES FOR SATURDAY WILL EASILY REACH 100 DEGREES FOR MANY LOCATIONS. AT THIS TIME...FIRE WEATHER CONCERNS WILL GENERALLY STILL BE HELD IN CHECK AS SATURDAYS WIND SPEEDS MAY BE AROUND A BORDERLINE 15 MPH WITH RH VALUES ALSO IN THE LOWER TEENS. WILL NEED TO KEEP A CLOSE EYE ON THE POSSIBILITY FOR SLIGHTLY STRONGER WINDS AND/OR SLIGHTLY DRIER RH VALUES...WHICH WOULD RAISE FIRE WEATHER CONCERNS. LATER ON SATURDAY...THE FLOW ALOFT BEGINS TO TURN MORE FROM THE SW...COURTESY OF THE LARGE PACNW TROUGH WHICH WILL PERSIST THROUGH THE REMAINDER OF THE ENTIRE FORECAST WITH OFF AND ON CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGHOUT. BMICKELSON .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY... GOING FORECAST LOOKED GOOD. MODEL CONFIDENCE ON PRECIPITATION IS LOW AS STRONG UNSTABLE SW JET STREAM INTERACTS WITH A DRY DESERT AIR MASS. TFJ PREVIOUS DISCUSSION... HOT UPPER RIDGE OVER THE REGION EXPECTED TO BREAK DOWN OVER THE WEEKEND AS THE UPPER LOW CURRENTLY IN THE EAST PACIFIC MOVES ONSHORE. THIS TROF WILL BE REINFORCED BY WAVES DROPPING OUT OF ALASKA...MAINTAINING THE TROF OVER WESTERN CANADA THROUGH NEXT WEEK. COLD FRONT SWEEPS ACROSS THE REGION SATURDAY NIGHT WITH THE BEST CHANCE FOR SHOWERS OR THUNDERSTORMS FOLLOWING THE FRONT. AS THE UPPER TROF MOVES ONSHORE...SOUTHWEST FLOW INTO EASTERN MONTANA WILL KEEP TEMPERATURES NEAR NORMAL FOR THE REMAINDER OF THE WEEK. SOME MOISTURE MAY WORK INTO THE REGION BUT NONE OF THE MEDIUM RANGE MODELS INDICATE SIGNIFICANT UPPER ENERGY TO TRIGGER PRECIPITATION. EBERT && .AVIATION... SYNOPSIS: RIDGING WILL CONTINUE OVER THE REGION THROUGH THE PERIOD. FLIGHT CATEGORY: VFR. WIND AND WX: LIGHT WIND WILL GENERALLY SWITCH AROUND TO THE WEST ON FRIDAY. THIS COULD BRING A REDUCTION TO VISIBILITY TO MVFR LEVELS WITH SMOKE. PROTON && .FIRE WEATHER... NEXT FOCUS FOR FIRE WEATHER CONCERNS WILL BE SATURDAY AS THE UPPER-LEVEL RIDGE OF HIGH PRESSURE WILL RE-ASSERT ITSELF OVER THE REGION. A BREEZY TO SLIGHTLY GUSTY SOUTH WIND WILL SET UP. SATURDAYS HIGH TEMPERATURES WILL CLIMB TO AROUND 100 DEGREES AND THE LOWEST RH VALUES WILL BE SOMEWHERE IN THE LOW TO MID TEENS. ONLY SLIGHT CHANGES IN THESE PARAMETERS WOULD RAISE FIRE WEATHER CONCERNS FOR SATURDAY. WILL DEFER TO NEXT THE SHIFT AS SATURDAY IS STILL DAY 3 OF THE FORECAST. BMICKELSON && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
343 PM CDT WED AUG 26 2015 .SYNOPSIS... ISSUED AT 341 PM CDT WED AUG 26 2015 UPPER LEVEL RIDGE ACROSS THE ROCKIES...WITH A TROUGH ACROSS NEW ENGLAND. SHORTWAVE MOVING ACROSS THE CREST OF THE RIDGE...CAUSING THE RIDGE TO FLATTEN. ELONGATED SFC HIGH ACROSS MUCH OF THE MISS RVR VALLEY. A STALLED BOUNDARY ANALYZED FROM A LOW OVER MONTANA...THEN MEANDERS SE INTO CENTRAL KS. ALSO A DISTINCT DRY LINE ACROSS THE PANHANDLE AND EASTERN COLORADO...WHERE DEW POINTS HAVE FALLEN INTO THE 30S AND 40S WITH TEMPS NEAR/ABOVE 100. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 341 PM CDT WED AUG 26 2015 MAIN FOCUS WILL BE THUNDERSTORM CHANCES THE NEXT 24 HOURS. FIRST WILL BE EARLY THIS EVENING ACROSS SOUTHWEST NEB...ALONG THE DRY LINE. A COUPLE CU CLOUDS HAVE DEVELOPED...HOWEVER DEVELOPMENT IS MINIMAL AND SHALLOW...SUGGESTING A CAP STILL IN PLACE. THE NAM/GFS/EC KEEP THIS AREA QUIET...HOWEVER THE NEAR TERM RAP/HRRR IN AGREEMENT A FEW ISOLD STORMS TO DEVELOP. THE RAP AND HRRR SUGGEST STORMS SHOULD ALREADY BE DEVELOPED. HAVE A DRY FORECAST AT THE MOMENT...THINKING THE NEAR TERM MODELS ARE SLIGHTLY OVERDONE WITH MOISTURE AVAILABLE. THAT SAID...INVERTED V SOUNDING WEST OF THE DRY LINE AND CAN NOT RULE OUT A STRAY STRONG STORM DEVELOPING. WILL CONTINUE TO MONITOR. NEXT FOCUS WILL BE FOLLOWING A COMBINATION OF A LEAD SHORTWAVE RIDING THE CREST OF THE RIDGE ACROSS SOUTHERN S DAKOTA AND INTO NORTHEASTERN NEB. THIS WILL COMBINE WITH LIFT FROM A NOCTURNAL LL JET. MODELS IN GOOD AGREEMENT WITH THE NOSE NEAR THE NEB/S DAKOTA BORDER. ANY ACTIVITY SHOULD DRIFT EAST THEN TURN TO THE SOUTHEAST. THIS FOCUSES ACTIVITY ACROSS THE NORTHERN ZONES. TOMORROW THE MAIN WAVE WILL CROSS THE AREA. MODELS HAVE SLOWED THE SPEED FROM EARLIER RUNS. THIS WAVE HAS GOOD SUPPORT AND THE DEEPENING MID LEVEL LOW WILL AID IN LIFT. MORNING CHANCES ARE MINIMAL AS CAP IN PLACE...ALTHOUGH WILL HAVE TO MONITOR POSSIBLE REMNANT OUTFLOW BOUNDARIES. OTHERWISE EXPECT EARLY AFTERNOON DEVELOPMENT ACROSS THE WESTERN CWA WHICH WILL MOVE EAST. GOOD INSTABILITY AND MARGINAL SHEAR SHOULD BE ENOUGH FROM SOME STRONG STORMS. SHOULD SEE SOME MORE CLOUDS AND HIGHS HOLD IN THE 80S FOR MOST LOCATIONS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 341 PM CDT WED AUG 26 2015 THE FRONT SWINGS THROUGH CENTRAL NEBRASKA THURSDAY NIGHT...BUT MOISTURE WRAPPING AROUND THE UPPER LOW/TROUGH COULD STILL BRING THE POSSIBILITY OF SHOWERS AND ISOLATED THUNDERSTORMS TO NORTH CENTRAL NEBRASKA FRIDAY MORNING. AFTER FRIDAY...LOW LEVEL FLOW WILL RETURN TO THE SOUTH AND BRING WARMER TEMPERATURES TO CENTRAL AND WESTERN NEBRASKA THROUGH SATURDAY. THE RETURN FLOW WILL ALSO BEGIN BRINGING MOISTURE TO THE HIGH PLAINS FROM THE SOUTHWEST U.S. AND INCREASING THE LOW LEVEL THETA-E. IN ADDITION...DESTABILIZATION IS LIKELY IN THE THETA-E RIDGE. ANOTHER BOUNDARY COMING ACROSS THE STATE COULD BRING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS TO WESTERN NEBRASKA NEBRASKA EARLY NEXT WEEK. CURRENT INDICATIONS ARE THAT THE BEST MOISTURE WILL BE OVER THE SOUTHEAST U.S. AS A TROPICAL SYSTEM INTERACTS WITH A WEAK STATIONARY FRONT ACROSS THE GULF COAST STATES AND THE MOISTURE ON THE HIGH PLAINS WILL BE LIMITED TO PRECIPITABLE WATER OF AN INCH OR LESS. THIS WOULD ALSO LIMIT THE COVERAGE OF THE CONVECTION AND PRETTY MUCH LIMIT IT TO THE NEBRASKA PANHANDLE AND WESTERN SANDHILLS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1214 PM CDT WED AUG 26 2015 VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THROUGH THURSDAY AFTERNOON. THE PRIMARY CONCERN THROUGH WEDNESDAY EVENING IS THE WIND...WHICH WILL BE BREEZY AT TIMES OUT OF THE SOUTH/SOUTHEAST. WEDNESDAY NIGHT...THERE IS A CHANCE OF THUNDERSTORMS ACROSS NORTHERN NEBRASKA...INCLUDING KVTN. FELT COVERAGE WILL LIKELY BE TOO LIMITED TO WARRANT TSRA IN THE CURRENT FORECAST. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MASEK SHORT TERM...MASEK LONG TERM...SPRINGER AVIATION...DS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
502 AM EDT WED AUG 26 2015 .SYNOPSIS... A WEAK COLD FRONT WILL SLOWLY MOVE OFF OF THE COAST TODAY AND TONIGHT. THE FRONT WILL THEN LINGER JUST OFFSHORE INTO FRIDAY. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THIS WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 415 AM WEDNESDAY...SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP IN VICINITY OF THE SOUTHWARD DRIFTING COLD FRONT WHICH APPEARED TO BE LOCATED ACROSS THE CRYSTAL COAST EARLY THIS MORNING. THE FRONT MAY BRIEFLY PUSH BACK INLAND THIS AFTERNOON WITH THE SEA BREEZE. GUIDANCE SEEMS TO BE SUGGESTING THAT CURRENT SCATTERED ACTIVITY WILL DISSIPATE BY 15Z THEN THERE WILL BE A LULL UNTIL AROUND 18Z WHEN ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP WITH HEATING. MID LEVEL WINDS INCREASE TO AROUND 30 KT WHICH COULD LEAD TO BETTER ORGANIZATION OF DIURNAL CONVECTION, BUT LAPSE RATES WILL BE POOR LIMITING SEVERE POTENTIAL ALTHOUGH GUSTY WINDS WILL BE POSSIBLE IN THE STRONGER STORMS. THE MAIN THREAT CONTINUES TO BE LOCALLY HEAVY RAINS DUE TO HIGH PW VALUES OF 1.5-2" AND THE POSSIBILITY OF TRAINING CELLS. UPPER LEVEL DIVERGENCE WILL BE FAVORABLE FOR LIFT AS OUR REGION WILL BE IN THE RIGHT ENTRANCE OF THE JET. USED A BLEND OF THE MET/ECMWF MOS POPS AS THE GFS POPS LOOKED TOO LOW. IT WILL ONLY TAKE A LITTLE SUNSHINE TO HELP BOOST TEMPS AND WILL FORECAST HIGHS AROUND 90 INLAND AND MID TO UPPER 80S COAST. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... AS OF 415 AM WEDNESDAY...THE FRONT IS FORECAST TO COMPLETELY MOVE OFF OF THE COAST LATE THEN STALL OFFSHORE OVERNIGHT. ALTHOUGH COVERAGE OF PRECIPITATION IS EXPECTED TO DIMINISH WITH LOSS OF HEATING THE AIRMASS WILL REMAIN MOIST AND EASTERN NC WILL REMAIN IN A FAVORABLE QUAD OF THE UPPER JET PRODUCING LIFT. THUS WILL NEED TO CONTINUE CHANCE POPS HIGHEST COAST NEAR THE DEPARTING FRONT. LOWS WILL IN THE UPPER 60S INLAND AND AND MID 70S BEACHES. THERE WILL BE A POTENTIAL FOR LOW CLOUDS AND FOG TO DEVELOP AS THE LOW LEVEL FLOW BECOMES EASTERLY. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 430 AM WEDNESDAY...THE UPPER TROUGH AXIS THAT HAS BEEN ACROSS THE EASTERN CONUS WILL SHIFT EAST INTO NC THURSDAY WHILE DE- AMPLIFYING THROUGH THURSDAY NIGHT. WEAK ZONAL FLOW DEVELOPS FRIDAY WITH THE UPPER RIDGE OVER BERMUDA BUILDING WEST TOWARDS THE SOUTHEASTERN STATES. AT THE SURFACE, A WEAK FRONT WILL REMAIN STALL OFF THE NC COAST THROUGH FRIDAY. LITTLE CHANGE IN FORECAST REASONING BASED ON 00Z GUIDANCE THROUGH THE PERIOD. AN UPPER LEVEL JET CONTINUES ACROSS THE MID ATLANTIC AND NEW ENGLAND COAST THROUGH THURSDAY WITH COASTAL AND OFFSHORE AREAS OF EASTERN NC POSITIONED IN THE FAVORABLE RIGHT ENTRANCE REGION OF THE JET. THE FRONTAL BOUNDARY AND DEEPEST MOISTURE REMAINS STALLED OFFSHORE THROUGH THURSDAY NIGHT AND WILL MAINTAIN SLIGHT CHANCE POPS INLAND TO HIGH CHANCE POPS FOR COASTAL SECTIONS. THE UPPER RIDGE ACROSS THE WESTERN ATLANTIC BUILDS WEST INTO THE SOUTHEAST FRIDAY THROUGH EARLY NEXT WEEK WHILE A ROBUST NORTHERN STREAM SHORTWAVE MOVES ACROSS THE MIDWEST INTO THE WEEKEND AND LIFTS OVER THE RIDGE LATE IN THE WEEKEND AND EARLY NEXT WEEK. AT THE SURFACE, HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO SATURDAY, THEN TRANSITIONS OFFSHORE WITH THE PIEDMONT TROUGH DEVELOPING SUNDAY THROUGH TUESDAY. SOME UNCERTAINTY IN THE TIMING AND STRENGTH OF THE SHORTWAVE BUT IT APPEARS DEEPER MOISTURE AND BETTER DYNAMICS WILL REMAIN JUST WEST AND NORTH OF EASTERN NC AND WILL CONTINUE TO FORECAST A MORE TYPICAL DIURNALLY DRIVEN, MAINLY ISOLATED SHOWER/THUNDERSTORM PATTERN THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST. EYES WILL BE ON THE TROPICS THIS WEEKEND AS NHC HAS TS ERIKA FORECAST TO MOVE INTO THE BAHAMAS BUT THERE IS A SIGNIFICANT UNCERTAINTY IN THE STRENGTH AND TRACK OF THE SYSTEM BEYOND DAY 3 WITH POOR RUN TO RUN CONSISTENCY IN THE MODELS AND IT IS TOO SOON TO SPECULATE AT THIS TIME WHAT IMPACTS MAY BE FELT ACROSS THE REGION NEXT WEEK. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 115 AM WEDNESDAY...VERY DIFFICULT FORECAST TRYING TO DETERMINE WHERE PREVAILING MVFR TO IFR CONDITIONS WILL PREVAIL OVERNIGHT. DEWPOINTS ARE HIGHER THAN PREVIOUS FEW NIGHTS AND WINDS HAVE AGAIN DECOUPLED. RADIATIONAL COOLING SET TO TAKE OFF BUT FOR AREA OF LOWER CLOUDS STREAMING NORTHEAST ALONG A STALLED BOUNDARY DRAPED SOUTHWEST TO NORTHEAST ACROSS EASTERN NC. WITH WET SOILS IN AREAS THAT EARLIER RECEIVED RAIN THINK FOG POTENTIAL IS FAIRLY GOOD BUT CLOUDS WILL LIKELY CONTINUE TO STREAM OVER THE AREA FOR AT LEAST THE NEXT COUPLE OF HOURS INHIBITING FOG DEVELOPMENT. WILL CONTINUE PREVIOUS FORECAST AND INTRODUCE PREVAILING IFR CIGS/VSBYS 7-9Z BASED ON AVIATION MOS AND HRRR AND NARRE AVIATION GUIDANCE. IFR WILL IMPROVE TO VFR 12-14Z WEDNESDAY AS SURFACE BASED MOISTURE MIXES OUT WITH SUB VFR CONDITIONS AGAIN EXPECTED IN VICINITY OF SCATTERED SHOWERS AND THUNDERSTORMS. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 430 AM WEDNESDAY...A WEAK COLD FRONT WILL LINGER OFFSHORE THURSDAY WITH COASTAL TERMINALS HAVING BETTER CHANCES OF BEING IMPACTED BY SHRA/TSRA BRINGING REDUCED CIGS/VSBYS. PREDOMINANT VFR CONDITIONS EXPECTED THURSDAY NIGHT THROUGH SUNDAY WITH ONLY ISOLATED, MAINLY DIURNALLY DRIVEN SHRA/TSRA. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 415 AM WEDNESDAY...THE FRONT IS BEGINNING TO MOVE OFF OF THE CRYSTAL COAST EARLY THIS MORNING BUT SHOULD RETREAT BACK TO THE NORTH THIS AFTERNOON. THE FRONT IS THEN FORECAST TO MOVE OFFSHORE AND STALL LATER TONIGHT. THROUGH THIS EVENING WINDS WILL REMAIN LIGHT OUTSIDE OF CONVECTION /10 KT OR LESS/ WITH THE FLOW BECOMING NORTHEAST TO EAST. AFTER MIDNIGHT TONIGHT WINDS ARE FORECAST TO INCREASE TO 10 TO 15 KT AS HIGH PRESSURE BEGINS TO BUILD INTO THE WATERS FROM THE NORTH. SEAS WILL BE IN THE 2 TO 4 FT RANGE MAINLY IN LONG PERIOD SWELL. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 430 AM WEDNESDAY...A WEAK COLD FRONT WILL LINGER OFFSHORE THROUGH FRIDAY, PRODUCING NE WINDS 15 KT OR LESS THROUGH THURSDAY GRADUALLY VEERING TO E THURSDAY NIGHT AND FRIDAY AS HIGH PRESSURE BUILDS INTO THE MID-ATLANTIC REGION. THE HIGH WILL SHIFT OFF THE MID-ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY WITH WINDS AROUND 10 KT OR LESS SATURDAY AND SUNDAY. WIND DIRECTION WILL GENERALLY BE EAST TO SOUTHEAST BUT BECOMING VARIABLE AT TIMES WITH WEAK GRADIENTS ACROSS THE REGION. SEAS WILL RANGE 1-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR THE OUTER CENTRAL WATERS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...JME SHORT TERM...JME LONG TERM...SK AVIATION...JME/SK MARINE...JME/SK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT WED AUG 26 2015 .SYNOPSIS...A STALLED FRONT WILL PERSIST IN VICINITY OF THE CAROLINA COAST THROUGH THE DURATION OF THE WEEK. && .NEAR TERM /OVERNIGHT/... AS OF 935 PM TUESDAY... 00Z MESO-ANALYSIS DEPICTS A TONGUE OF MOISTURE AND INSTABILITY ACROSS THE COASTAL PLAIN...AND INTO THE EASTERN SECTIONS OF THE SANDHILLS. PRECIP WATER VALUES WERE AVERAGING 1.6-1.7 INCHES IN THIS REGION. FARTHER WEST...PRECIP WATER VALUES AVERAGED 1.1 INCHES. WATER VAPOR IMAGERY SUGGESTED A SHEAR AXIS EDGING SLOWLY EAST ACROSS EASTERN NC. THIS FEATURE INTERACTING WITH AVAILABLE MOISTURE AND MODEST INSTABILITY WAS TRIGGERING A FEW SHOWERS ALONG AND EAST OF HIGHWAY 1...MAINLY IN VICINITY OF WILSON...AND OVER SECTIONS OF THE WESTERN SANDHILLS. LATEST RUC MODEL SUGGEST A VORT MAX AND ATTENDANT SHEAR AXIS DRIFTING EAST ALONG THE SC-NC BORDER THROUGH THE PRE-DAWN HOURS. BASED ON HOW WELL ISOLATED-SCATTERED CONVECTION HAS MAINTAINED ITSELF THROUGH MID EVENING AND NEAR TERN MODELS SUGGESTING A THREAT LASTING WELL INTO THE NIGHT...WILL MAINTAIN A SLIGHT-SMALL CHANCE POP...GENERALLY ALONG AND EAST OF I-95 THROUGH THE PRE-DAWN HOURS. ANOTHER SHEAR AXIS NOTED CROSSING THE TN-LOWER OH VALLEY THIS EVENING...APPROACHING THE SOUTHERN-CENTRAL APPALACHIANS. WHILE MOISTURE IS MORE LIMITED OVER WESTERN NC...THIS FEATURE MAY ENHANCE CLOUDINESS A BIT AND POSSIBLY TRIGGER A SPRINKLE OR TWO OVERNIGHT IN VICINITY OF THE TRIAD. IN ANTICIPATION OF MORE CLOUDINESS...HAVE RAISED MIN TEMPS ABOUT TWO DEGREES IN SOME SPOTS...ESPECIALLY IN THE NW PIEDMONT. MIN TEMPS SHOULD VARY FROM THE MID 60S NW TO AROUND 70 SE. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 100 PM TUESDAY... LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED ON WED...WITH THE UNSEASONABLY STRONG UPPER LEVEL LOW STALLED NORTH OF THE GREAT LAKES...CYCLONIC FLOW ALOFT ALONG THE EASTERN SEABOARD...AND A STALLED FRONTAL ZONE IN VICINITY OF THE CAROLINA/SOUTHEAST COAST. AS A RESULT...EXPECT CONDITIONS ON WED TO BE SIMILAR TO TODAY...WITH THE BEST POTENTIAL FOR CONVECTION IN COASTAL/FAR-EASTERN NORTH CAROLINA. WILL KEEP PRECIP CHANCES GENERALLY CONFINED TO THE FAR SE COASTAL PLAIN COUNTIES (I.E. CUMBERLAND/SAMPSON/WAYNE). ADDITIONAL SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE WESTERN PERIPHERY OF THE STALLED UPPER LOW IS PROGGED TO PROGRESS INTO THE CENTRAL APPALACHIANS LATE WED NIGHT...AND IT IS POSSIBLE THAT THE FRONTAL ZONE SHIFTS FURTHER INLAND (ALONG WITH A POTENTIAL FOR PRECIP) AFTER MIDNIGHT AS LOW-LEVEL WIND/HEIGHT FIELDS RESPOND TO THE APPROACHING SHORTWAVE. FORECAST CONFIDENCE REMAINS LOW WITH REGARD TO THE EVOLUTION/TIMING OF THE APPROACHING WAVE...THE STALLED FRONTAL ZONE...AND WHETHER AN INLAND SHIFT IN PRECIPITATION WILL OCCUR (AS THE GFS SUGGESTS) OR PRECIPITATION REMAINS ALONG THE COAST (AS THE NAM SUGGESTS). -VINCENT && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 300 AM WEDNESDAY... IN THE WAKE OF THE EASTERN US TROUGH LIFTING NEWD INTO EASTERN CANADA...WEAK TROUGHINESS WILL EXTEND FROM THE CENTRAL GULF NORTHWARD INTO THE LOWER MS VALLEY AS THE SUBTROPICAL RIDGE OVER THE WESTERN ATLANTIC RETROGRADES TOWARDS THE SOUTHEAST COAST. MEANWHILE AT THE SURFACE...WEAK SURFACE HIGH WILL SLIDE EASTWARD OVER THE MID- ATLANTIC STATES...WHICH SHOULD NUDGE THE LINGERING SURFACE FRONTAL BOUNDARY EVER SO SLIGHTLY SOUTHEASTWARD...REMAINING NEAR THE SOUTHEAST COAST THROUGH THE WEEKEND. UNDER INCREASING HEIGHTS ALOFT AND WEAK SFC HIGH PRESSURE...FRIDAY AND SATURDAY LOOKS MOSTLY DRY ACROSS CENTRAL NC WITH RAIN CHANCES MAINLY CONFINED TO THE DIFFERENTIAL HEATING OVER MTNS AND FTHLS AND ALONG THE IMMEDIATE COAST INVOF OF THE LINGERING SFC BOUNDARY. BY SUNDAY...SHOWERS AND STORMS COULD RETURN TO THE AREA...ESPECIALLY ACROSS WESTERN PORTION S OF THE STATE WHERE THE APPROACH OF MID/UPPER LEVEL SHORTWAVE TROUGH OVER THE UPPER MS VALLEY/LOWER GREAT LAKES COULD KICK THE LINGERING WEAK TROUGHINESS OVER LOWER MS VALLEY EASTWARD INTO THE AREA. SEASONABLE TEMPERATURES WITH HIGHS IN THE MID TO UPPER 80S. LOWS 65 TO 70. FORECAST CONFIDENCE DECREASES BY EARLY NEXT WEEK DUE TO UNCERTAINTY OF HOW MUCH SUBTROPICAL RIDGING EXISTS OVER THE SOUTHEAST...WHICH WILL GREATLY DETERMINE THE EVOLUTION TRACK OF TC ERICKA. REGARDLESS...HEIGHTS WILL INCREASE EARLY NEXT WEEK AND SHOULD SEE AN UPTICK IN TEMPS...UPPER 80S TO LOWER 90S MONDAY AND TUESDAY...WITH AT LEAST WIDELY SCATTERED DIURNAL CONVECTION IN THE MOIST AIRMASS. STAY TUNED. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 200 AM WEDNESDAY... 24 HOUR TAF PERIOD: ALL THE SENSIBLE WEATHER IN THE TAF PERIOD WILL MOST LIKELY OCCUR IN THE EASTERN HALF OF THE AREA WITH KFAY AND KRWI BEING THE PRIMARY TERMINALS AFFECTED. AS FAR AS CONVECTION IS CONCERNED...THERE ARE CURRENTLY SHOWERS AND THUNDERSTORMS IN THE VICINITY OF KFAY AND THESE ARE EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS BUT WEAKEN OVER TIME. OF SECONDARY CONCERN WILL BE AREAS OF FOG THIS EVENING...PARTICULARLY AT KRWI AND KFAY. TO THIS POINT...ANY OBSERVATIONS OF VISIBILITY RESTRICTIONS HAVE BEEN IN THE MVFR RANGE AND THIS IS EXPECTED TO BE THE PRIMARY CATEGORY FOR THE EVENING WITH AN OUTSIDE CHANCE OF SOME IFR CONDITIONS...ESPECIALLY AFTER THE RAIN AT KFAY. LATER IN THE DAY EXPECT ANOTHER ROUND OF CONVECTION IN THE EAST...WITH KRWI AND KFAY ONCE AGAIN THE MOST LIKELY AFFECTED HOWEVER IT IS POSSIBLE THAT SHORTWAVE ENERGY WILL HELP SOME ISOLATED SHOWER ACTIVITY FURTHER WEST IN THE VICINITY OF KRDU NEAR THE END OF THE TAF PERIOD. LONG TERM: WITH THE FRONTAL ZONE STALLING OUT OVER THE EASTERN HALF OF THE STATE...TERMINALS ALONG AND EAST OF ROUTE 1 WILL BE UNDER CONTINUED THREAT FOR DAILY SHOWERS AND THUNDERSTORMS...PARTICULARLY DURING AFTERNOON PEAK HEATING. TRIAD TERMINALS SHOULD REMAIN LARGELY VFR FOR MUCH OF THE WEEK BUT UNCERTAINTY INCREASES TOWARDS THE WEEKEND WHEN THE FRONTAL ZONE COULD RETROGRADE A LITTLE AS A WEAK LOW FORMS SOUTH OF THE AREA. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...WSS SHORT TERM...VINCENT LONG TERM...CBL AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
203 AM EDT WED AUG 26 2015 .SYNOPSIS...A STALLED FRONT WILL PERSIST IN VICINITY OF THE CAROLINA COAST THROUGH THE DURATION OF THE WEEK. && .NEAR TERM /OVERNIGHT/... AS OF 935 PM TUESDAY... 00Z MESO-ANALYSIS DEPICTS A TONGUE OF MOISTURE AND INSTABILITY ACROSS THE COASTAL PLAIN...AND INTO THE EASTERN SECTIONS OF THE SANDHILLS. PRECIP WATER VALUES WERE AVERAGING 1.6-1.7 INCHES IN THIS REGION. FARTHER WEST...PRECIP WATER VALUES AVERAGED 1.1 INCHES. WATER VAPOR IMAGERY SUGGESTED A SHEAR AXIS EDGING SLOWLY EAST ACROSS EASTERN NC. THIS FEATURE INTERACTING WITH AVAILABLE MOISTURE AND MODEST INSTABILITY WAS TRIGGERING A FEW SHOWERS ALONG AND EAST OF HIGHWAY 1...MAINLY IN VICINITY OF WILSON...AND OVER SECTIONS OF THE WESTERN SANDHILLS. LATEST RUC MODEL SUGGEST A VORT MAX AND ATTENDANT SHEAR AXIS DRIFTING EAST ALONG THE SC-NC BORDER THROUGH THE PRE-DAWN HOURS. BASED ON HOW WELL ISOLATED-SCATTERED CONVECTION HAS MAINTAINED ITSELF THROUGH MID EVENING AND NEAR TERN MODELS SUGGESTING A THREAT LASTING WELL INTO THE NIGHT...WILL MAINTAIN A SLIGHT-SMALL CHANCE POP...GENERALLY ALONG AND EAST OF I-95 THROUGH THE PRE-DAWN HOURS. ANOTHER SHEAR AXIS NOTED CROSSING THE TN-LOWER OH VALLEY THIS EVENING...APPROACHING THE SOUTHERN-CENTRAL APPALACHIANS. WHILE MOISTURE IS MORE LIMITED OVER WESTERN NC...THIS FEATURE MAY ENHANCE CLOUDINESS A BIT AND POSSIBLY TRIGGER A SPRINKLE OR TWO OVERNIGHT IN VICINITY OF THE TRIAD. IN ANTICIPATION OF MORE CLOUDINESS...HAVE RAISED MIN TEMPS ABOUT TWO DEGREES IN SOME SPOTS...ESPECIALLY IN THE NW PIEDMONT. MIN TEMPS SHOULD VARY FROM THE MID 60S NW TO AROUND 70 SE. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 100 PM TUESDAY... LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED ON WED...WITH THE UNSEASONABLY STRONG UPPER LEVEL LOW STALLED NORTH OF THE GREAT LAKES...CYCLONIC FLOW ALOFT ALONG THE EASTERN SEABOARD...AND A STALLED FRONTAL ZONE IN VICINITY OF THE CAROLINA/SOUTHEAST COAST. AS A RESULT...EXPECT CONDITIONS ON WED TO BE SIMILAR TO TODAY...WITH THE BEST POTENTIAL FOR CONVECTION IN COASTAL/FAR-EASTERN NORTH CAROLINA. WILL KEEP PRECIP CHANCES GENERALLY CONFINED TO THE FAR SE COASTAL PLAIN COUNTIES (I.E. CUMBERLAND/SAMPSON/WAYNE). ADDITIONAL SHORTWAVE ENERGY DIGGING SOUTHEAST ALONG THE WESTERN PERIPHERY OF THE STALLED UPPER LOW IS PROGGED TO PROGRESS INTO THE CENTRAL APPALACHIANS LATE WED NIGHT...AND IT IS POSSIBLE THAT THE FRONTAL ZONE SHIFTS FURTHER INLAND (ALONG WITH A POTENTIAL FOR PRECIP) AFTER MIDNIGHT AS LOW-LEVEL WIND/HEIGHT FIELDS RESPOND TO THE APPROACHING SHORTWAVE. FORECAST CONFIDENCE REMAINS LOW WITH REGARD TO THE EVOLUTION/TIMING OF THE APPROACHING WAVE...THE STALLED FRONTAL ZONE...AND WHETHER AN INLAND SHIFT IN PRECIPITATION WILL OCCUR (AS THE GFS SUGGESTS) OR PRECIPITATION REMAINS ALONG THE COAST (AS THE NAM SUGGESTS). -VINCENT && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 115 PM TUESDAY... FRONTAL ZONE REMAINS PINNED ALONG THE NC COAST AS MILD HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES AND SOUTH DOWN THE EASTERN SPINE OF THE APPALACHIANS INTO THE WEEKEND. MEANWHILE...ALOFT...THE FRONTAL ZONE LIES BETWEEN A WEAK UPPER TROF OVER THE ATLANTIC COAST AND STRONGER OFFSHORE RIDGE WHICH WILL BEGIN TO RETROGRADE INTO THE SOUTHEAST ATLANTIC COAST...PROVIDING ADDITIONAL MOISTURE AS WELL AS NUDGING THE FRONT SLOWLY INLAND. WILL KEEP THE CHANCE OF RAIN ONLY MARGINALLY ABOVE CLIMATOLOGICAL...~30%...AND FOCUSED PRIMARILY ON THE SOUTHEAST THROUGH SATURDAY. CLOUDINESS WILL BECOME MORE PREVALENT ON SATURDAY AS OVERRUNNING EASTERLY FLOW SETS UP...WHICH COULD LEAD TO INCREASING POPS AS THE WEEKEND APPROACHES. HIGHS EACH DAY WILL BE PRETTY NEAR CLIMATOLOGICAL...POTENTIALLY COOLER ON SATURDAY...POSSIBLY SUNDAY AS WELL...IF THE DAMMING AND PRECIP SCENARIO MATERIALIZES. UNCERTAINTY INCREASES BY EARLY NEXT WEEK AS WE WILL POTENTIALLY BE SUBJECT TO THE INFLUENCE OF TS ERIKA. WE WILL BE IN THE WEAK TROF AREA BETWEEN AN AMPLIFYING RIDGE IN THE MIDWEST AND THE STRONGER AND STILL RETROGRADING SUBTROPICAL RIDGE OVER THE SOUTHWEST ATLANTIC...WHICH SHOULD BE THE DETERMINING STEERING MECHANISM FOR ERIKA OR HER REMAINS. REGARDLESS...HEIGHTS WILL INCREASE EARLY NEXT WEEK AND SHOULD SEE AN UPTICK IN TEMPS...UPPER 80S TO LOWER 90S MONDAY AND TUESDAY...WITH AT LEAST WIDELY SCATTERED DIURNAL CONVECTION IN THE MOIST AIRMASS. STAY TUNED. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 200 AM WEDNESDAY... 24 HOUR TAF PERIOD: ALL THE SENSIBLE WEATHER IN THE TAF PERIOD WILL MOST LIKELY OCCUR IN THE EASTERN HALF OF THE AREA WITH KFAY AND KRWI BEING THE PRIMARY TERMINALS AFFECTED. AS FAR AS CONVECTION IS CONCERNED...THERE ARE CURRENTLY SHOWERS AND THUNDERSTORMS IN THE VICINITY OF KFAY AND THESE ARE EXPECTED TO CONTINUE FOR THE NEXT SEVERAL HOURS BUT WEAKEN OVER TIME. OF SECONDARY CONCERN WILL BE AREAS OF FOG THIS EVENING...PARTICULARLY AT KRWI AND KFAY. TO THIS POINT...ANY OBSERVATIONS OF VISIBILITY RESTRICTIONS HAVE BEEN IN THE MVFR RANGE AND THIS IS EXPECTED TO BE THE PRIMARY CATEGORY FOR THE EVENING WITH AN OUTSIDE CHANCE OF SOME IFR CONDITIONS...ESPECIALLY AFTER THE RAIN AT KFAY. LATER IN THE DAY EXPECT ANOTHER ROUND OF CONVECTION IN THE EAST...WITH KRWI AND KFAY ONCE AGAIN THE MOST LIKELY AFFECTED HOWEVER IT IS POSSIBLE THAT SHORTWAVE ENERGY WILL HELP SOME ISOLATED SHOWER ACTIVITY FURTHER WEST IN THE VICINITY OF KRDU NEAR THE END OF THE TAF PERIOD. LONG TERM: WITH THE FRONTAL ZONE STALLING OUT OVER THE EASTERN HALF OF THE STATE...TERMINALS ALONG AND EAST OF ROUTE 1 WILL BE UNDER CONTINUED THREAT FOR DAILY SHOWERS AND THUNDERSTORMS...PARTICULARLY DURING AFTERNOON PEAK HEATING. TRIAD TERMINALS SHOULD REMAIN LARGELY VFR FOR MUCH OF THE WEEK BUT UNCERTAINTY INCREASES TOWARDS THE WEEKEND WHEN THE FRONTAL ZONE COULD RETROGRADE A LITTLE AS A WEAK LOW FORMS SOUTH OF THE AREA. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...WSS SHORT TERM...VINCENT LONG TERM...MLM AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
118 AM EDT WED AUG 26 2015 .SYNOPSIS... A WEAK COLD FRONT WILL STALL OVER THE AREA TONIGHT AND WEDNESDAY. THE FRONT WILL THEN SLOWLY MOVE OFF THE COAST WEDNESDAY NIGHT AND THURSDAY BUT LINGER JUST OFFSHORE INTO FRIDAY. WEAK HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 115 AM WEDNESDAY...VERY WEAK GRADIENT CONTINUES ACROSS EASTERN NC AND THIS HAS LED TO WINDS DECOUPLING ACROSS MOST OF THE AREA. THIS MAKES TRYING TO LOCATE THE WEAK FRONT/WIND SHIFT VERY DIFFICULT LATE TONIGHT. BEST GUESS PLACES THE NEARLY STATIONARY BOUNDARY ACROSS NE SECTIONS OF NC EXTENDING BACK SW ACROSS THE COASTAL PLAIN. A FEW SHOWERS AND THUNDERSTORMS LINGER NEAR THE BOUNDARY VICINITY OF THE SAND HILLS WITH ISOLATED SHOWERS CURRENTLY DEVELOPING COASTAL DARE AND HYDE COUNTIES. WILL NEED TO CONTINUE LOW CHANCE POPS OVERNIGHT GIVEN THE LINGERING SFC FRONT AND MOIST BOUNDARY LAYER AMID CYCLONIC FLOW ALOFT. PATCHY FOG LIKELY OVERNIGHT ESPECIALLY IN AREAS THAT RECEIVED RAIN TODAY. MIN TEMPS FROM UPR 60S INLAND TO LOW-MID 70S COAST. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 AM THURSDAY/... AS OF 330 PM TUESDAY...STALLED FRONT AND WEAK SHRT WV ENERGY PATTERN WILL PERSIST THROUGH WED...WITH MODELS INDICATING SCT SHOWERS/TSTMS WITH LOCALLY HEAVY RAIN PSBL MOST OF DAY BUT MAINLY IN SEA BREEZE ZONE DURING AFTN. MAX TEMPS MID TO UPR 80S. && .LONG TERM /THURSDAY THROUGH WEDNESDAY/... AS OF 255 PM TUESDAY...AN UPPER LOW NORTH OF THE GREAT LAKES WILL PUSH EAST ACROSS QUEBEC WEDNESDAY INTO THURSDAY, ALLOWING THE UPPER TROUGH AXIS TO SHIFT EAST INTO NC BY THURSDAY THEN DE- AMPLIFYING AS IT CROSSES THE CAROLINAS INTO THURSDAY NIGHT. WEAK ZONAL FLOW DEVELOPS FRIDAY WITH THE UPPER RIDGE OVER BERMUDA BUILDING WEST TOWARDS THE SOUTHEASTERN STATES. AT THE SURFACE, A WEAK FRONT ACROSS EASTERN NC WILL MOVE OFF THE COAST AND STALL WEDNESDAY NIGHT THROUGH FRIDAY. LITTLE CHANGE IN FORECAST REASONING BASED ON 12Z GUIDANCE THROUGH THE PERIOD. UPPER LEVEL JET STRENGTHENS ACROSS THE MID ATLANTIC AND NEW ENGLAND COAST WEDNESDAY NIGHT THROUGH THURSDAY WITH COASTAL AND OFFSHORE AREAS OF EASTERN NC POSITIONED IN THE FAVORABLE RIGHT ENTRANCE REGION OF THE JET. THE FRONTAL BOUNDARY AND DEEPEST MOISTURE REMAINS STALLED OFFSHORE THROUGH THURSDAY NIGHT AND WILL MAINTAIN SLIGHT CHANCE POPS INLAND TO HIGH CHANCE POPS FOR COASTAL SECTIONS. THE UPPER TROUGH LIFTS NORTH OF THE REGION THURSDAY NIGHT WITH THE UPPER RIDGE ACROSS THE WESTERN ATLANTIC BUILDING WEST INTO THE SOUTHEAST FRIDAY THROUGH EARLY NEXT WEEK. MEANWHILE, SURFACE HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO SATURDAY, THEN TRANSITIONS OFFSHORE WITH THE PIEDMONT TROUGH DEVELOPING SUNDAY THROUGH TUESDAY. EXPECT A MORE TYPICAL DIURNALLY DRIVEN, MAINLY ISOLATED SHOWER/THUNDERSTORM PATTERN THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST. && .AVIATION /05Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH WEDNESDAY NIGHT/... AS OF 115 AM WEDNESDAY...VERY DIFFICULT FORECAST TRYING TO DETERMINE WHERE PREVAILING MVFR TO IFR CONDITIONS WILL PREVAIL OVERNIGHT. DEWPOINTS ARE HIGHER THAN PREVIOUS FEW NIGHTS AND WINDS HAVE AGAIN DECOUPLED. RADIATIONAL COOLING SET TO TAKE OFF BUT FOR AREA OF LOWER CLOUDS STREAMING NORTHEAST ALONG A STALLED BOUNDARY DRAPED SOUTHWEST TO NORTHEAST ACROSS EASTERN NC. WITH WET SOILS IN AREAS THAT EARLIER RECEIVED RAIN THINK FOG POTENTIAL IS FAIRLY GOOD BUT CLOUDS WILL LIKELY CONTINUE TO STREAM OVER THE AREA FOR AT LEAST THE NEXT COUPLE OF HOURS INHIBITING FOG DEVELOPMENT. WILL CONTINUE PREVIOUS FORECAST AND INTRODUCE PREVAILING IFR CIGS/VSBYS 7-9Z BASED ON AVIATION MOS AND HRRR AND NARRE AVIATIONGUIDANCE. IFR WILL IMPROVE TO VFR 12-14Z WEDNESDAY AS SURFACE BASED MOISTURE MIXES OUT WITH SUB VFR CONDITIONS AGAIN EXPECTED IN VICINITY OF SCATTERED SHOWERS AND THUNDERSTORMS. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 245 PM TUESDAY...A WEAK COLD FRONT WILL LINGER OFFSHORE WEDNESDAY NIGHT AND THURSDAY WITH COASTAL TERMINALS HAVING BETTER CHANCES OF BEING IMPACTED BY SHRA/TSRA BRINGING REDUCED CIGS/VSBYS. PREDOMINANT VFR CONDITIONS EXPECTED THURSDAY NIGHT THROUGH SATURDAY WITH ONLY ISOLATED, MAINLY DIURNALLY DRIVEN SHRA/TSRA. && .MARINE... SHORT TERM /THROUGH WEDNESDAY/... AS OF 115 AM WEDNESDAY...STALLED SFC FRONT INLAND TONIGHT WILL CONTRIBUTE TO A WEAK PRES GRADIENT RESULTING IN SOUTHERLY WINDS 10 KT OR LESS ACROSS THE MARINE AREA THROUGH PERIOD. WW3 AND NWPS IN GOOD AGREEMENT WITH LONG PERIOD SEAS PERSISTING AT 2-3 FT. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AS OF 250 PM TUESDAY...A WEAK COLD FRONT WILL LINGER OFFSHORE THROUGH FRIDAY, PRODUCING NE WINDS 10 KT OR LESS THROUGH THURSDAY. E/NE WINDS INCREASE SOME FRIDAY INTO FRIDAY EVENING, AROUND 10 TO 15 KT, AS GRADIENT TIGHTENS DUE TO HIGH PRESSURE BUILDING INTO THE MID-ATLANTIC REGION. THE HIGH WILL SHIFT OFF THE MID-ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY WITH WINDS BECOMING PREDOMINANTLY EASTERLY AROUND 10 KT OR LESS SATURDAY AND SUNDAY, SHIFTING SOUTHEASTERLY LATE SUNDAY. SEAS WILL RANGE 1-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR THE OUTER CENTRAL WATERS FRIDAY THROUGH SUNDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JBM NEAR TERM...JME/BTC SHORT TERM...JBM LONG TERM...DAG AVIATION...JME/DAG MARINE...JME/BTC/JBM/DAG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
338 PM CDT WED AUG 26 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 332 PM CDT WED AUG 26 2015 500 MB UPPER RIDGE BUILDING FROM NEW MEXICO INTO ERN WYOMING. SEVERAL SHORT WAVES SEEN MOVING ON TOP OF UPPER RIDGE INTO WRN/CNTRL ND AND SOUTH DAKOTA TODAY. SOME BANDS OF MID AND HIGH LEVEL CLOUD COVER WITH THESE WAVES AND NOT SURE IF MODELS ARE HANDLING THESE CLOUDS BANDS ALL THAT GOOD. ONE CLOUD BAND NORTH OF WILLISTON TO RUGBY MOVING EAST-SOUTHEAST AND THE OTHER SOUTH OF WATFORD CITY TO BISMARCK MOVING SOUTHEAST. THE NRN CLOUD BAND ISNT HANDLED BY THE MODELS WELL AT ALL AS THEY WANT TO DRY UP THE CLOUDS TOO MUCH IT SEEMS. OTHER CLOUD BAND HANDLED OK BY HRRR IN HAVING A FEW SPRINKLES INTO SCNTRL ND EARLY EVENING. LATEST HRRR HAS A FEW RW-- INTO FAR SE ND AS WELL OVERNIGHT. WILL MAINTAIN DRY FCST AND LATER SHIFTS CAN ADD RW-- HAS NEEDED. IT WOULD BE VERY VERY MINOR. WARMER THAN THE LAST FEW NIGHTS AS SOUTHERLY WINDS HOLD UP ENOUGH FOR MORE MIXING. MAIN SHORT WAVE WILL MOVE EAST AND TEMPORARILY SQUASH THE RIDGE AND MOVE THRU SRN SD INTO SRN MN/NRN IA LATER THURSDAY AFTERNOON AND NIGHT. NRN EDGE OF ANY PRECIP WILL JUST SKIRT THE FAR SRN FCST AREA SO CONFINED POPS TO THAT AREA ONLY. A FEW DEGREES WARMER ON THURSDAY AS WELL. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 332 PM CDT WED AUG 26 2015 A SHORT WAVE MOVING EAST THRU SRN CANADA WILL BRING A RISK OF A T-STORM TO THE CANADIAN BORDER REGION FRI AFTN-EVE.. BIT BETTER RISK IN LAKE OF THE WOODS AREA FRI EVE. OTHERWISE GETTING WARMER STILL AS UPPER AIR RIDGE BEINGS TO BUILD NORTHWARD. UPPER AIR BUILDS INTO NORTH DAKOTA SATURDAY AS HIGH TEMPS CLIMB WELL INTO THE 80S. IT WILL BE DRY. SATURDAY NIGHT-WEDNESDAY...A VERY WARM AND FAIRLY QUIET PERIOD IS EXPECTED. A WEST TO SOUTHWEST FLOW PATTERN ALOFT WILL PERSIST OVER THE N PLAINS WITH THE MEAN UPPER RIDGE OVER THE EASTERN CONUS AND PERSISTENT TROUGHING OVER THE PACIFIC NORTHWEST. WITH THE UPPER JET REMAINING NORTH INTO CANADA...ORGANIZED PRECIP CHANCES LOOK LOW. SOME UPPER LEVEL ENERGY WILL SLIDE NORTH ACROSS CENTRAL CANADA EARLY IN THE WEEK...POSSIBLY DRAGGING A SFC TROUGH INTO THE AREA WITH MAYBE A FEW STORMS. OTHERWISE...ANY OTHER STORMS WILL DEPEND ON SUBTLE FORCING WITH WEAK UPPER WAVES. TEMPS WILL REMAIN ABOVE AVERAGE...WITH HIGHS GENERALLY IN THE 80S TO PERHAPS LOW 90S IN SPOTS...AND LOWS IN THE 60S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1257 PM CDT WED AUG 26 2015 VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH GENERALLY SOUTHERLY FLOW UP TO AROUND 10 KTS (POSSIBLY LIGHT AND VARIABLE IN SPOTS EARLY THURSDAY) AND PATCHES OF MID/HIGH CLOUDS.| && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...RIDDLE LONG TERM...MAKOWSKI/RIDDLE AVIATION...MAKOWSKI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1134 PM CDT TUE AUG 25 2015 .UPDATE... ISSUED AT 1134 PM CDT TUE AUG 25 2015 NO CHANGES FOR THIS UPDATE. UPDATE ISSUED AT 944 PM CDT TUE AUG 25 2015 RAP AND HRRR HAVE STARTED TO DEVELOP SOME LOW VIS FROM THE NORTHERN RED RIVER VALLEY EASTWARD. DEW POINTS IN THAT AREA HAVE BEEN COMING UP AS THE BOUNDARY LAYER DECOUPLES...AND THERE HAS BEEN A DROP TO 7 MILES VIS AT LANGDON. THINK SOME VERY PATCHY SHALLOW FOG WILL BE POSSIBLE PARTICULARLY OVER PLACES THAT HAVE RECENT RAINFALL. DO NOT THINK IT WILL LAST LONG WITH THE SFC HIGH MOVING EAST...BUT THREW IN A BRIEF MENTION OF PATCHY FOG IN THE NORTHERN VALLEY SHORTLY AFTER 07Z AND TRANSITIONING OVER INTO NORTHWEST MN TOWARDS MORNING. UPDATE ISSUED AT 634 PM CDT TUE AUG 25 2015 NO CHANGES TO THE GOING FORECAST. SOME SMOKE FROM FIRES TO OUR NORTHWEST BEGINNING TO MOVE INTO THE WESTERN COUNTIES. HOWEVER...IT IS ALL HIGH LEVEL AT THIS POINT AND WILL HOLD OFF ON ANY INCLUSION IN THE GRIDS UNTIL IT CAUSES REDUCTION IN VIS AT THE SFC. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 312 PM CDT TUE AUG 25 2015 MAIN FORECAST CHALLENGE WILL BE TEMPS...UNTIL THE NEXT CHANCE OF PCPN ROLLS IN FOR THU INTO FRI. AS OF MID AFTERNOON THERE WERE A FEW PATCHES OF MID CLOUDS MOVING INTO THE WESTERN FA. A FEW ECHOES WERE EVEN SHOWING UP ON RADAR BUT THINK THIS IS VIRGA AT MOST. LOOKING AT MAINLY CLEAR SKIES TONIGHT WITH LIGHT WINDS. THE THIN SMOKE LAYER WILL CONTINUE TO OVERSPREAD THE AREA TOO...BUT IT DOES APPEAR TO BE PRETTY THIN AT THIS POINT. THERE WAS SOME PATCHY FOG AROUND THIS MORNING...BUT IT WAS ISOLATED TO JUST A FEW RIVER VALLEYS. THINK THE THIN SMOKE LAYER OVER THE FA WED WILL BE LIKE A CIRRUS LAYER. HIGHS LOOKING A FEW DEGREES WARMER THAN TODAY. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 312 PM CDT TUE AUG 25 2015 MODELS ARE DELAYING THE ONSET OF THE THU PCPN CHANCES TO THE AFTERNOON TIME FRAME...AND MAINLY ALONG/SOUTH OF HIGHWAY 2. THESE CHANCES WILL SPREAD INTO THE EAST BY THU. NOT LOOKING LIKE A LOT OF PCPN FOR THIS AREA AS THE MAIN PCPN SWATH STAYS WELL TO THE SOUTH AND EAST. SATURDAY TO TUESDAY...OVERALL DRY WEATHER ACROSS THE NORTHERN PLAINS FOR THE UPCOMING WEEKEND AND INTO NEXT WEEK. 500MB UPPER LEVEL RIDGE WILL BE RESPONSIBLE FOR ABOVE NORMAL TEMPS AND THE DRY FORECAST. A SHORT WAVE WILL BEGIN TO IMPINGE ON THE RIDGE BY MONDAY BRINGING A SLGT CHC OF THUNDER TO THE WESTERN AREAS AND THE ENTIRE AREA BY TUESDAY. WITH WEEKEND HIGHS IN THE 80S THE MAX TEMPS WILL BE 5 TO 10 DEGREES ABOVE NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1134 PM CDT TUE AUG 25 2015 VFR CONDITIONS WILL CONTINUE...THERE COULD BE SOME PATCHY SHALLOW FOG IN SOME SPOTS BUT DO NOT THINK IT WILL AFFECT TAF SITES AT THIS TIME. SOME SMOKE FROM WESTERN FIRES WILL CONTINUE BUT THINK IT WILL STAY HIGH LEVEL AT THIS POINT. LIGHT AND VARIABLE WINDS WILL PICK UP OUT OF THE SOUTHEAST BY TOMORROW AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...GODON LONG TERM...GODON/JK AVIATION...JR
AREA FORECAST DISCUSSION
NWS TULSA OK
541 AM CDT WED AUG 26 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. LIGHT FOG WILL BE POSSIBLE AT BVO/RVS THROUGH ABOUT 14Z. VFR CONDITIONS AND LIGHT WINDS WILL PREVAIL AT ALL TERMINALS THEREAFTER. && .PREV DISCUSSION... /ISSUED 239 AM CDT WED AUG 26 2015/ DISCUSSION... WE`LL HAVE A PLEASANT START TO THE DAY WITH TEMPS IN THE 50S/60S AND VERY COMFORTABLE DEWPOINTS. BOTH THE NAM AND HRRR HINT AT SOME WEAK CONVECTION THIS MORNING IN THE DEVELOPING MID-CLOUD DECK CURRENTLY STREAMING INTO CENTRAL OK...BUT INDICATIONS ARE THAT ANY ACTIVITY WOULD BE JUST WEST OF OUR AREA. OTHERWISE...EXPECT ANOTHER NICE AFTERNOON WITH TEMPS RUNNING A FEW DEGREES WARMER THAN YESTERDAY. AN UPPER SYSTEM WILL MOVE INTO THE CENTRAL PLAINS LATER THIS WEEK...BRINGING A WEAK MID-LEVEL SHEAR AXIS AND SURFACE FRONT INTO THE AREA. BROAD SURFACE RIDGING ACROSS THE GULF WILL LIMIT MOST OF THE DEEPER MOISTURE RETURN...SO CHANCES/COVERAGE OF PRECIPITATION FOR FRIDAY INTO EARLY SATURDAY WILL REMAIN LOW. THE UPPER RIDGE WILL STRENGTHEN AGAIN LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK...WITH SEVERAL DAYS OF MILD OVERNIGHT LOWS AND SEASONALLY HOT DAYTIME TEMPS IN STORE. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...22
AREA FORECAST DISCUSSION
NWS TULSA OK
239 AM CDT WED AUG 26 2015 .DISCUSSION... WE`LL HAVE A PLEASANT START TO THE DAY WITH TEMPS IN THE 50S/60S AND VERY COMFORTABLE DEWPOINTS. BOTH THE NAM AND HRRR HINT AT SOME WEAK CONVECTION THIS MORNING IN THE DEVELOPING MID-CLOUD DECK CURRENTLY STREAMING INTO CENTRAL OK...BUT INDICATIONS ARE THAT ANY ACTIVITY WOULD BE JUST WEST OF OUR AREA. OTHERWISE...EXPECT ANOTHER NICE AFTERNOON WITH TEMPS RUNNING A FEW DEGREES WARMER THAN YESTERDAY. AN UPPER SYSTEM WILL MOVE INTO THE CENTRAL PLAINS LATER THIS WEEK...BRINGING A WEAK MID-LEVEL SHEAR AXIS AND SURFACE FRONT INTO THE AREA. BROAD SURFACE RIDGING ACROSS THE GULF WILL LIMIT MOST OF THE DEEPER MOISTURE RETURN...SO CHANCES/COVERAGE OF PRECIPITATION FOR FRIDAY INTO EARLY SATURDAY WILL REMAIN LOW. THE UPPER RIDGE WILL STRENGTHEN AGAIN LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK...WITH SEVERAL DAYS OF MILD OVERNIGHT LOWS AND SEASONALLY HOT DAYTIME TEMPS IN STORE. && .PRELIMINARY POINT TEMPS/POPS... TUL 90 66 92 71 / 0 0 0 10 FSM 89 65 91 67 / 0 0 10 0 MLC 90 62 92 67 / 0 0 10 10 BVO 90 62 91 68 / 0 0 0 20 FYV 86 58 87 62 / 0 10 10 0 BYV 84 58 85 60 / 0 10 10 0 MKO 89 64 90 67 / 0 0 10 0 MIO 89 61 91 66 / 0 10 10 10 F10 89 65 91 68 / 0 0 0 10 HHW 93 64 93 65 / 0 0 10 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...22 LONG TERM....18
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
254 PM CDT WED AUG 26 2015 .SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)... ISOLATED SHOWERS HAVE DEVELOPED OVER THE HILL COUNTRY AND EDWARDS PLATEAU. THE LATEST TEXAS TECH WRF AND HRRR RUNS INDICATE THIS ACTIVITY WILL REMAIN ISOLATED AND BARELY BRING MEASURABLE RAIN TO ONLY A FEW SPOTS. WE HAVE REMOVED THE CHANCE FOR DOWNDRAFT WINDS IN THE HAZARDOUS WEATHER OUTLOOK. OTHERWISE...WE EXPECT THE SHOWERS TO QUICKLY DIE BY SUNSET. DRY AIR CONTINUES TO FILTER INTO THE REGION...AND WHEN COUPLED WITH SUBSIDENCE BELOW THE UPPER LEVEL RIDGE...WE EXPECT MOSTLY CLEAR SKIES OVERNIGHT...WITH THE EXCEPTION OF SOME LOW CLOUDS ALONG THE BALCONES ESCARPMENT. && .LONG TERM (FRIDAY THROUGH WEDNESDAY)... THE UPPER LEVEL RIDGE SLIDES A BIT WEST OVER THE NEXT FEW DAYS...WITH A RESULTING DROP IN HIGH AND LOW TEMPERATURES. EARLY MORNINGS WILL BE PLEASANT FOR THE TIME OF YEAR...BUT AFTERNOONS STILL WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. A CUTOFF LOW/TROUGH EVENTUALLY CARVES OUT OVER NORTHEAST TEXAS EARLY NEXT WEEK...AND COMBINES WITH THE REMNANTS OF ERIKA TO PRODUCE A LONGWAVE TROUGH OVER THE EASTERN U.S.. GULF MOISTURE WILL COINCIDE WITH THE TROUGH DEVELOPMENT...AND HENCE BRING A CHANCE OF RAIN BY THE MIDDLE OF NEXT WEEK. HOWEVER...THE WESTERN EDGE OF THE TROUGH WILL HAVE A SHARP GRADIENT OF COVERAGE...SO AT THIS TIME WE WILL KEEP POPS LOW. LOWER HEIGHTS AND CLOUDCOVER SHOULD DROP TEMPS TO NEAR NORMAL...LOWER 90S FOR HIGHS AT MANY LOCATIONS...AND LOWS AROUND 70...BY THE END OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 73 99 73 99 72 / - - 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 70 98 70 97 69 / - - 0 0 0 NEW BRAUNFELS MUNI AIRPORT 72 99 72 98 70 / - - 0 0 0 BURNET MUNI AIRPORT 72 98 71 97 71 / - - 0 0 0 DEL RIO INTL AIRPORT 77 100 73 101 72 / - - 0 0 0 GEORGETOWN MUNI AIRPORT 71 98 72 98 72 / - - 0 0 0 HONDO MUNI AIRPORT 73 98 70 98 69 / - - 0 0 0 SAN MARCOS MUNI AIRPORT 72 98 71 97 70 / - - 0 0 0 LA GRANGE - FAYETTE REGIONAL 69 97 71 97 70 / - - 0 0 0 SAN ANTONIO INTL AIRPORT 75 98 73 97 72 / - - 0 0 0 STINSON MUNI AIRPORT 75 99 72 99 71 / - - 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...24 SYNOPTIC/GRIDS...26 PUBLIC SERVICE/DATA COLLECTION...LH
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1011 AM CDT WED AUG 26 2015 .UPDATE... IT/S TOUGH TO FIND THE WEAK BOUNDARY OVER THE HILL COUNTRY/EDWARDS PLATEAU...BUT ONCE MIXING COMMENCES WE EXPECT IT TO LIE ROUGHLY ALONG I-10 NORTH OF SAN ANTONIO AND ALONG 1-37 SOUTH OF SAN ANTONIO. RECENT HRRR RUNS POINT TOWARD CONVECTIVE INITIATION ALONG THIS BOUNDARY AROUND 19-20Z...WITH STORMS THEN MOVING/PROPAGATING WEST-SOUTHWEST THROUGH THE EDWARDS PLATEAU AND POSSIBLY INTO THE RIO GRANDE PLAINS. WILL SEND AN UPDATE SHORTLY TO RE-TREND HOURLY VARIABLES THOUGH 00Z...BUT THE MAIN FORECAST ADJUSTMENT IS TO RE- ORIENT POPS ALONG AND WEST OF THE BOUNDARY LOCATION. && .PREV DISCUSSION... /ISSUED 611 AM CDT WED AUG 26 2015/ AVIATION... ISOLD SHRA/TSRA ARE EXPECTED TODAY. HOWEVER...WILL NOT MENTION AT THE TAF SITES AS PROBS 20 OR LESS. WILL MONITOR RADAR AND MODEL TRENDS FOR POSSIBLE UPDATES TO MENTION. VFR FLYING CONDITIONS WILL PREVAIL TODAY THROUGH THURSDAY MORNING. HOWEVER...PATCHY STRATUS AT MVFR LEVEL FROM KBAZ TO KHDO TO KCOT TO KBEA WILL PERSIST THROUGH MID MORNING. BRIEF MVFR/IFR CIGS/VSBYS ARE ALSO POSSIBLE IN SHRA/TSRA. E TO SE WINDS 10 KTS OR LESS PREVAIL. EXCEPT...WIND GUSTS UP TO 35 KTS ARE POSSIBLE IN/NEAR SHRA/TSRA. PREV DISCUSSION... /ISSUED 328 AM CDT WED AUG 26 2015/ SHORT TERM (TODAY THROUGH THURSDAY)... A QUASI STATIONARY BOUNDARY WILL CONTINUE ITS SLOW TREK WESTWARD TODAY AND WITH IT A SLIGHT CHANCE FOR SOME ISOLATED THUNDERSTORMS. RAP FORECAST SOUNDINGS ARE ADVERTISING PRETTY DRY AIR EAST OF THE BOUNDARY EFFECTIVELY CUTTING OFF ANY CHANCES FOR PRECIP. HOWEVER...TO THE WEST...INSTABILITY AND LOW LEVEL LAPSE RATES SHOULD BE ENOUGH TO FIRE SOME CONVECTION BY THE TIME CONVECTIVE TEMPERATURES REACH THE MID 90S OR BY JUST AFTER NOON. HI RES MODELS ARE SHOWING SOME VARIABILITY IN THE COVERAGE BUT EVEN THE MORE ROBUST OUTCOMES ARE SHOWING ONLY ISOLATED CELLS FIRING WEST OF THE BOUNDARY AS IT PROGRESSES WEST. THERE ARE A LOT OF FACTORS THAT WILL PROHIBIT SIGNIFICANT GROWTH OF ANY UPDRAFTS TODAY BUT THERE IS STILL THE POSSIBILITY OF SOME GUSTY WINDS WITH THE DRY LOW LEVELS. ALTHOUGH WITH PWAT VALUES EXPECTED TO FALL BELOW 1.5 INCHES AND A VERY DRY COLUMN ABOVE 700 MB...THERE PROBABLY WONT BE ENOUGH PRECIP GENERATED FOR SIGNIFICANT DOWNBURST WINDS. THURSDAY SHOULD BE ANOTHER HOT DAY BUT WITH SOME WELCOME DRYNESS AS DEWPOINTS LOOK TO RISE INTO THE UPPER 60S IN THE SOUTHERN HALF OF THE CWA AND LOWER 60S UP NORTH. SHOULD RESULT IN LOW RELATIVE HUMIDITIES THURSDAY AFTERNOON. LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)... AN UPPER LEVEL LOW WILL INTENSIFY OVER THE ROCKIES AND WALTZ AROUND THE UPPER RIDGE AXIS THROUGH THE WEEK WHICH WILL EFFECTIVELY SHIFT THE RIDGE CENTER FARTHER WESTWARD BY THE WEEKEND. THIS WILL ALLOW A WEAK LOW PRESSURE SYSTEM JUST OFF THE COAST TO CREEP ONSHORE AND UP THE RIO GRANDE VALLEY BY EARLY NEXT WEEK. SEEMS THIS OUTCOME IS FAIRLY WELL AGREED UPON BY BOTH THE GFS AND ECMWF. DURING THIS TRANSITION PERIOD OVER THE WEEKEND...VERY LIGHT WINDS AT THE SURFACE AND ALOFT WILL ALLOW FOR CONDITIONS FAVORABLE FOR THE SEA BREEZE TO PUSH WELL NORTHWEST INTO OUR CWA. WITH A COUPLE DAYS OF THIS OCCURRING...LOW LEVEL MOISTURE WILL BE SPREAD INTO THE COASTAL PLAINS AND SOUTH TEXAS. WHAT THIS MEANS FOR EARLY NEXT WEEK IS THE OPPORTUNITY FOR SOME RAINFALL TUESDAY AND WEDNESDAY AS WELL AS CLOUD COVER AND MOST NOTABLY...A DECREASE IN MAX TEMPS. TAKING A LOOK AT THE LONG RANGE TEMPERATURE GUIDANCE...MEX HIGHS FOR THE PLATEAU MAY NOT EVEN REACH 90 BY NEXT WEDNESDAY. WOULDNT THAT JUST BE SWELL? BEYOND THAT...THE UPPER LOW WILL CONTINUE TO WEAKEN AND MOVE OFF TO THE NORTHEAST ALLOWING RIDGING TO SHIFT EASTWARD AGAIN TOWARDS CENTRAL TEXAS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 97 72 98 73 99 / 10 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 95 69 96 69 97 / 10 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 98 72 99 71 98 / 10 0 0 0 0 BURNET MUNI AIRPORT 95 72 97 71 97 / 10 0 0 0 0 DEL RIO INTL AIRPORT 100 77 101 73 100 / 20 0 0 0 0 GEORGETOWN MUNI AIRPORT 96 71 97 71 98 / 10 0 0 0 0 HONDO MUNI AIRPORT 98 73 98 69 98 / 20 10 0 0 0 SAN MARCOS MUNI AIRPORT 96 72 97 71 97 / 10 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 95 69 97 71 97 / 10 - 0 0 0 SAN ANTONIO INTL AIRPORT 98 75 97 73 97 / 20 - 0 0 0 STINSON MUNI AIRPORT 98 74 99 72 98 / 20 - 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...24 SYNOPTIC/GRIDS...26 PUBLIC SERVICE/DATA COLLECTION...LH
AREA FORECAST DISCUSSION
NWS PORTLAND OR
235 AM PDT WED AUG 26 2015 .SYNOPSIS...AN UPPER LOW OFF OF THE BRITISH COLUMBIA COAST WILL PRODUCE SOUTHWEST FLOW ALOFT ACROSS THE PACIFIC NORTHWEST THE NEXT SEVERAL DAYS. THE MAIN IMPACT FROM THIS LOW WILL BE A SLOWLY DEVELOPING MARINE LAYER ALONG THE COAST THAT WILL NOT EXTEND FAR INLAND. WEAK DISTURBANCES ROTATING AROUND THE LOW WILL GIVE A SLIGHT CHANCE OF THUNDER NEAR THE CENTRAL OREGON CASCADE CREST THE NEXT FEW DAYS WITH THE MAIN ACTIVITY MOVING OUT INTO CENTRAL OREGON. THE LOW WILL MOVE ONSHORE LATE IN THE WEEK AND ON THE WEEKEND WITH AN INCREASING GOOD CHANCE OF SHOWERS AND POSSIBLY THE FIRST GOOD WETTING RAIN IN QUITE SOME TIME. && .SHORT TERM...NOT MUCH CHANGE IN THE WEATHER EXPECTED TODAY AS A LARGE UPPER LOW REMAINS OFF THE COAST NEAR 140W...AND A SW FLOW ALOFT CONTINUES. SURFACE RIDGE JUST OFF THE COAST ALSO EXPECTED TO REMAIN...RESULTING IN A CONTINUED ONSHORE FLOW. MODELS INDICATE LITTLE CHANGE TO AIR MASS TODAY WITH H8 TEMPS OVER THE INTERIOR EXPECTED TO REMAIN ON THE ORDER OF 16 DEG C...WHICH SHOULD KEEP TEMPS CLOSE TO NORMAL. A SHORTWAVE IS SEEN IN WATER VAPOR PICTURES EARLY THIS MORNNING S OF 40N NEAR 135W AND EXPECTED TO LIFT ACROSS THE S PART OF THE FORECAST AREA THIS EVENING. FORECAST INSTABILITY OF THE AIR MASS IN THE MODELS HOWEVER IS MARGINAL AS SEEN IN MODEL SOUNDINGS...AND WITH THE FLOW A LITTLE W OF S...WHATEVER SMALL CHANCE THERE IS FOR THUNDER THIS AFTERNOON WILL LIKELY BE LIMITED TO THE CREST AND POINTS E. THE SW FLOW ALOFT CONTINUES THU AND CHANGES TO THE AIR MASS APPEAR MINIMAL EXCEPT FOR AN OVERALL INCREASE IN MOISTURE AND CLOUDS. WILL CONTINUE TO CARRY A MENTION FOR SOME DRIZZLE ALONG THE COAST AS SUGGESTED BY EC QPF FIELDS...BUT THE THREAT FOR PRECIPITATION IMPROVES MORE THU NIGHT INTO FRI AS MOISTURE CONTINUES TO DEEPEN AND THE UPPER TROUGH BEGINS TO INCH CLOSER. INITIAL THREAT FOR RAIN WILL BE LIMITED PRIMARILY TO COASTAL AREAS THU NIGHT AS A WEAK FRONT PUSHES IN AND ONSHORE COMPONENT OF LOW LEVEL FLOW STRENGTHENS. MODELS IN GOOD AGREEMENT IN SPREADING THE THREAT FOR RAIN INLAND FRI AS A SHORTWAVE ROUNDS THE BASE OF THE LOW AND APPROACHES THE COAST PUSHING THE WEAK BAROCLINIC ZONE FURTHER IN. BEST CHANCES ON FRI WILL REMAIN ON THE COAST HOWEVER...AND WITH CONFIDENCE IN MODELS INCREASING WILL CARRY LIKELY POPS FOR COASTAL AREAS FRI. INCREASED THREAT FOR RAIN AND THICKER CLOUDS WILL RESULT IN COOLER TEMPS FRI. .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...FRIDAY NIGHT THROUGH TUESDAY...MODELS ARE IN PRETTY GOOD AGREEMENT THAT THE UPPER LOW CURRENTLY OFF THE COAST OF BRITISH COLUMBIA WILL DIG SOUTHWARD OVER THE WEEKEND BRINGING COOLER AND WETTER WEATHER CONTINUING INTO EARLY NEXT WEEK. A SURFACE FRONT OUT AHEAD OF THE MAIN UPPER LEVEL SYSTEM WILL MOVE ONSHORE FRIDAY NIGHT INTO SATURDAY MORNING WHICH MODELS PREDICT WILL BRING WIDESPREAD RAIN ACROSS WESTERN WASHINGTON AND OREGON. BY SATURDAY AFTERNOON RAIN WILL BECOME MORE SHOWERY BEHIND THE FRONT AS AN UNSTABLE AIRMASS MOVES OVER THE AREA. THE UPPER LEVEL SYSTEM MOVES ACROSS THE AREA LATE SATURDAY NIGHT OR EARLY SUNDAY WHICH WILL BRING ANOTHER ROUND OF RAIN TO AT LEAST THE NORTHERN HALF OF OUR AREA...THOUGH PROBABLY LESS THAN WE SEE ON SATURDAY. COOLER WEATHER CONTINUES WITH CHANCES FOR SHOWERS THROUGH EARLY NEXT WEEK AS WE STAY UNDER NORTHWESTERLY FLOW ALOFT. MODELS HAVE BEEN INCONSISTENT WITH WHEN THE NEXT SHORTWAVE WILL ARRIVE SO HAVE LEFT A SLIGHT CHANCE OF SHOWERS THROUGH TUESDAY...THOUGH AS OF NOW IT LOOKS LIKE MONDAY COULD BE FAIRLY DRY. -MCCOY && .AVIATION...WITH LITTLE CHANGE TO THE OVERALL WEATHER PATTERN...EXPECT TONIGHT TO SIMILAR TO LAST NIGHT WITH SOME PATCHY MVFR STRATUS FORMING ALONG THE S WASHINGTON AND N OREGON COAST AND PATCHY MVFR VIS ALONG THE CENTRAL OREGON COAST. VFR CONDITIONS SHOULD RETURN TO THE COAST BY MID MORNING WED. VFR TO REMAIN IN CONTROL FOR THE NEXT 24 HRS FOR THE INTERIOR TAF SITES. A THIN SMOKE LAYER WILL CONTINUE TO AFFECT THE CASCADES AND SOUTHERN WILLAMETTE VALLEY THROUGH WEDNESDAY FROM FIRES OVER SW OREGON. KPDX AND APPROACHES...VFR CONTINUES WITH A FEW HIGH CLOUDS AND SOME RESIDUAL SMOKE AT HIGHER LEVELS...PARTICULARLY ON THE EASTERN APPROACHES THAT MAY RESTRICT SLANTWISE VISIBILITIES BELOW AROUND 9000 FT. BOWEN/PYLE && .MARINE...LITTLE CHANGE THROUGH WEDNESDAY. THERMAL TROUGH SITS OVER SW OREGON AND NW CALIFORNIA...WITH HIGHER PRES REMAINING OVER THE NE PAC. N TO NW WINDS OF 10 TO 15 KT TO CONTINUE. SEAS TO REMAIN AT 4 TO 5 FT. A PATTERN SHIFT LATER THIS WEEK WILL BRING LOW PRES INTO THE REGION AND A TRANSITION TO SOUTHERLY WINDS BEGINNING THU. CONFIDENCE IS INCREASING THAT A WELL-DEFINED FRONT WILL MOVE THROUGH THE WATERS LATE FRI INTO SAT. THIS FRONT WILL LIKELY BRING GUSTY S WINDS WITH GUSTS 25 TO 30 KT...WITH A LOW POSSIBILITY FOR GALES SATURDAY AND SATURDAY NIGHT. SEAS INCREASE STARTING LATE FRI...AND BUILD TO 7 TO 9 FT SATURDAY WITH A RATHER CONFUSED SEA STATE INCLUDING SOME WIND WAVE/FRESH SWELL COMBINATION ALONG WITH A FEW SIMILARLY SIZED SWELL COMPONENTS. AN UNSETTLED WEATHER PATTERN LOOKS LIKELY THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. BOWEN/PYLE && .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 National Weather Service Spokane WA 950 PM PDT TUE AUG 25 2015 .SYNOPSIS... Warm, dry and smoky conditions will continue this week. Strong inversions will likely lead to poor air quality due to high concentrations of wildfire smoke in the mornings. There is a chance of dry thunderstorms Wednesday night. The next significant round of wind, showers, and cooler weather looks to arrive for the upcoming weekend. && .DISCUSSION... Evening update: forecast is generally on track. I increased cloud cover some and tweaked the Wednesday morning lows, but they are expected to be similar this morning. The elevated and isolated and largely thunderstorm threat in the forecast still seems warranted. There is very little to the shortwave tracking up through OR into southern WA this hour, but there remains some elevated instability and the newest HRRR and 00Z Hi-Res NAM do indicated a few possible elevated showers passing. Still not much but more than earlier runs. Overall, I`m not expecting much to develop but there is the possibility. Additionally, the Red Flag Warning for dry, unstable conditions was allowed to expire at 9 PM. The next few days will remain hot, but overall High Level Haines index values appear to be lower (in the 3 to 4 range). Generally we`d like around 5 or 6, but still we will have to monitor the situation closely for anything that may lead to critical fire behavior. /J. Cote` && .AVIATION... 06Z TAFS: The region will remain in a southwest flow, with a weak upper impulse pushing this evening into the overnight. Some elevated instability will bring the off-chance of some thunderstorms and sprinkles, but the risk of them passing a TAF site at this time is too small to mention in the TAF forecast. However between 06 to 12Z there may be some isolated thunder, with the best chance at this time from MWH to GEG to COE. Smoke will continue to impact some TAF sites. Given recent patterns, we are expected VFR/MVFR conditions this evening, with a trend toward mainly MVFR late overnight into Wednesday morning, before some improvement in the afternoon again. Winds will be mainly light and diurnal. /J. Cote` && .PRELIMINARY POINT TEMPS/POPS... Spokane 61 90 63 89 62 84 / 10 10 10 10 10 10 Coeur d`Alene 56 91 57 89 57 84 / 10 10 10 10 10 10 Pullman 53 91 55 88 54 85 / 10 0 10 10 20 10 Lewiston 62 95 66 93 64 90 / 10 10 10 10 20 10 Colville 51 91 55 91 55 84 / 10 0 10 10 10 10 Sandpoint 49 88 51 88 51 83 / 10 10 10 10 20 10 Kellogg 55 91 55 88 55 84 / 10 0 10 20 20 10 Moses Lake 55 91 59 91 60 86 / 10 0 20 10 10 10 Wenatchee 62 92 68 92 67 81 / 10 0 10 10 10 20 Omak 57 91 61 91 60 82 / 10 0 10 10 10 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 PM CDT TUE AUG 25 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 325 PM CDT TUE AUG 25 2015 CHALLENGES TONIGHT THROUGH WEDNESDAY INCLUDE CLOUD TRENDS... TEMPERATURES AND FOG POTENTIAL. SOME DIFFERENCES BETWEEN MODELS WITH REGARD TO HOW QUICKLY CLOUDS DISSIPATE AND MOVE OUT TONIGHT... BUT OTHERWISE IN GOOD AGREEMENT AND WILL USE A BLENDED SOLUTION. 25.20Z SURFACE LOW ACROSS SOUTHERN HUDSON BAY WILL FINALLY BEGIN TO LIFT NORTH AND EAST TONIGHT...ALLOWING EXPANSIVE STRATOCUMULUS DECK ACROSS THE ENTIRE GREAT LAKES REGION TO SLOWLY MOVE OUT OF THE FORECAST AREA. 25.18Z RAP 1 KM 90 PERCENT RELATIVE HUMIDITY CONTOUR HAS BEEN A GOOD PROXY TO CURRENT CLOUD COVER AND SHOWS MOST CLOUDS DISSIPATE AND/OR MOVE EAST OF THE FORECAST AREA BY 25.06Z. THIS IDEA IS ALSO SUPPORTED BY LATEST NSSL SYNTHETIC IR...SO EXPECT CLEARING TO OVERSPREAD THE FORECAST AREA OVERNIGHT. WITH LIGHT WINDS DEEPENING TO AROUND 2000 FT AGL BY 25.09Z...THINK SOME VALLEY FOG IS POSSIBLE AND WILL CONTINUE TO MENTION IN LATEST FORECAST. TEMPERATURES TONIGHT WILL BOTTOM OUT FROM THE MID 40S TO LOWER 50S. WEDNESDAY WILL BE MOSTLY SUNNY AND DRY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE UPPER MS RIVER VALLEY. WINDS WILL BE LIGHT FROM THE NORTH-NORTHWEST WITH AFTERNOON HIGHS INTO THE UPPER 60S TO MID 70S. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM CDT TUE AUG 25 2015 SURFACE RIDGE AXIS MOVES OVER LAKE MICHIGAN BY 25.12Z...BUT LIGHT WINDS WILL CONTINUE THROUGH THE MORNING...DEEPENING TO NEARLY 6000 FT AGL. FOG POTENTIAL WILL HINGE ON POSSIBLE HIGH CLOUDS...BUT OTHERWISE A GOOD CHANCE AND WILL KEEP MENTION OF PATCHY VALLEY FOG. CLOUD COVER AND SOUTHERLY WINDS WILL INCREASE THROUGH THE DAY ON THURSDAY AHEAD OF THE NEXT LOW PRESSURE SYSTEM. ANY PRECIPITATION WILL REMAIN WEST OF THE FORECAST AREA...EXCEPT FOR A SMALL CHANCE LATE IN THE EVENING MAINLY WEST OF THE HIGHWAY 52 CORRIDOR. RISING 925 TO 850 HPA TEMPERATURES WILL ALLOW AFTERNOON HIGHS TO REACH THE MID TO UPPER 70S. FRIDAY NOW LIKELY TO BE CLOUDY AND WET AS AN EASTERN PACIFIC TROUGH UNDERCUTS THE WESTERN CONUS 500 HPA RIDGE AND MOVES INTO THE UPPER MIDWEST. 25.12Z MODEL SUITE PRODUCES A WELL DEFINED DEFORMATION PRECIPITATION AXIS ALONG ENHANCED 850 TO 700 HPA FRONTOGENESIS NORTH OF THE SURFACE LOW. ALTHOUGH THE GFS/ECMWF SURFACE LOW TRACKS ARE SIMILAR...MOVING FROM EAST-CENTRAL NE ACROSS SOUTHERN IA THROUGH THE DAY...THE ECMWF PAINTS THE HIGHEST RAINFALL A BIT FARTHER SOUTH COMPARED TO THE GFS/NAM WHICH ARE HIGHEST ACROSS THE FORECAST AREA. THE PAST THREE RUNS OF THE GFS HAVE BEEN SIMILAR...LENDING HIGHER CONFIDENCE TO ITS NORTHERN SOLUTION. WILL INCREASE POPS INTO THE LIKELY CATEGORY ON FRIDAY. HOWEVER...INSTABILITY STILL LOOKS VERY WEAK AND WILL CAP THUNDERSTORM CHANCES TO 20 PERCENT WITH LIGHT TO MODERATE SHOWERS BEING THE DOMINATE MODE. STILL A BIT EARLY TO GET TOO SPECIFIC WITH RAINFALL AMOUNTS...BUT SOME AREAS COULD SEE AMOUNTS IN EXCESS OF AN INCH THROUGH FRIDAY NIGHT. WITH CLOUDS AND RAIN... FRIDAY WILL BE COOL WITH HIGHS IN THE UPPER 60S TO NEAR 70 DEGREES. SOME LINGERING SHOWERS POSSIBLE SATURDAY...ESPECIALLY EAST OF THE MS RIVER...BUT OTHERWISE SHOULD SEE IMPROVING CONDITIONS WITH DECREASING CLOUD COVER AND RAIN CHANCES FROM WEST TO EAST. HIGHS WILL REBOUND BACK INTO THE MID 70S. SUNDAY THROUGH TUESDAY LOOK DRY WITH NO MAJOR SYSTEMS ON THE HORIZON. BIGGER CONCERN WILL BE RISING TEMPERATURES AS 500 HPA RIDGE AXIS FOLDS OVER ACROSS THE UPPER MIDWEST...RESULTING IN TEMPERATURES RISING INTO THE LOWER TO MID 80S BY THE EARLY PART OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1110 PM CDT TUE AUG 25 2015 HIGH PRESSURE WORKS IN TONIGHT...AND WILL BE THE MAIN WEATHER FEATURE THROUGH THU. WINDS WILL GENERALLY BE LIGHT AND NORTHERLY THROUGH WED...THEN LIGHT EAST/VRB WED NIGHT. WITH THE HIGH OVERHEAD...AND LIGHT SFC WINDS...VALLEY FOG BECOMES A CONCERN. KLSE T/TD DIFF AT 03Z WAS 5 F...GOOD FOR OVERNIGHT FOG FORMATION. SFC WINDS WERE CALM TO LIGHT. A NORTHERLY DIRECTION...EVEN LIGHT...CAN BE PROHIBITIVE TO DENSE FOG AT KLSE. MORE SIGNIFICANT IS THE DEPTH OF THE LIGHT WIND LAYER. RAP/HRRR/NAM BUFKIT SOUNDINGS CONTINUE TO SUGGEST THIS LAYER DOESN/T DEEPEN UNTIL AFTER 06Z. THIS MIGHT BE TOO SHORT OF A TIME TO ALLOW FOR EXTENSIVE FOG IN THE VALLEY. BCFG BKN003 STILL LOOKS A BIT MORE LIKELY THAN SUB 1/2SM FG AT THIS TIME...AND WILL LEAN THE FORECAST THIS WAY. TRENDS WILL BE MONITORED AND ADJUSTMENTS MADE IF NEEDED. THU MORNING SHOWS MORE PROMISE FOR FG AT KLSE. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ROGERS LONG TERM...ROGERS AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
207 AM MDT WED AUG 26 2015 .SHORT TERM...(TODAY THROUGH FRIDAY NIGHT) ISSUED AT 300 AM MDT WED AUG 26 2015 TODAY...WATER VAPOR SATELLITE IMAGERY SHOWS A DECENT FETCH OF SUBTROPICAL MOISTURE ADVECTING TOWARDS OUR REGION FROM UTAH AND ARIZONA...WHICH WILL BE THE MAIN WEATHER PLAYER THE NEXT FEW DAYS. THIS AFTERNOON...THE RIDGE ALOFT TRANSLATES INTO THE WESTERN HIGH PLAINS AS THE NEXT WELL ADVERTISED NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT APPROACHES WESTERN WYOMING. ALTHOUGH IT WILL TAKE AWHILE FOR LOW LEVELS TO BECOME MORE MOIST...IT APPEARS THERE WILL BE ENOUGH MID LEVEL MOISTURE TO SPARK SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING ALONG AND WEST OF INTERSTATE 25...WITH LESSER CHANCES FURTHER EAST. TONIGHT...SHORTWAVE TROUGH ALOFT MOVES SLOWLY OVERHEAD THUS KEEPING SHOWER AND THUNDERSTORM CHANCES GOING ALL NIGHT THOUGH LESS THAN CHANCES NEAR PEAK HEATING. THIS WILL PRODUCE A MILD NIGHT FOR LATE AUGUST. THURSDAY...THE SHORTWAVE TROUGH ALOFT MOVES INTO THE CENTRAL PLAINS STATES...THOUGH THERE WILL STILL BE ENOUGH RESIDUAL LOW AND MID LEVEL MOISTURE TO SPARK SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...ALONG WITH COOLER TEMPERATURES DUE TO A PASSING COLD FRONT AS WELL AS INCREASED CLOUD COVER. THURSDAY NIGHT/FRIDAY/FRIDAY NIGHT...RIDGING ALOFT BECOMES MORE PRONOUNCED WITH LOW AND MID LEVEL DRYING AND THUS LESS AND LESS CHANCES FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...EXCEPT NEAR THE MOUNTAINS DUE TO OROGRAPHICS AND DIFFERENTIAL HEATING. .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 300 AM MDT WED AUG 26 2015 STILL CONCERNS FOR STRONG WINDS SATURDAY OUT IN THE PANHANDLE. GFS CONTINUES TO FORECAST 850MB WINDS OF 40-50KTS OUT OVER THE PANHANDLE AFTER 00Z SUNDAY AND CONTINUING OVERNIGHT INTO SUNDAY. ECMWF SHOWING SIMILAR WIND SPEEDS. DID BEGIN TO INCREASE SPEEDS OUT THERE FOR SATURDAY NIGHT AND SUNDAY...BUT DO FEEL WE WILL PROBABLY NEED TO INCREASE MORE. 700MB WINDS INCREASING WEST OF THE LARAMIE RANGE SATURDAY AFTERNOON AS WELL. GFS SHOWING 700MB WINDS OF 20-25KTS SATURDAY AFTERNOON...INCREASING TO 25-30KTS SUNDAY. COULD BE A FIRE CONCERN SATURDAY AFTERNOON AS FORECAST AFTERNOON HUMIDITIES FORECAST DOWN TO 15 PERCENT IN BOTH CONVERSE AND SOUTHWESTERN CARBON COUNTIES. GUSTY WINDS CONTINUING INTO MONDAY AND TUESDAY AS A SHORTWAVE MOVES THROUGH MONTANA. DRIER AIR WITH MORE WIDESPREAD LOW AFTERNOON HUMIDITIES THROUGH THE FIRST PART OF NEXT WEEK. COULD BE DEALING WITH RED FLAGS EACH DAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1047 PM MDT TUE AUG 25 2015 GETTING SOME LIGHTNING STRIKES JUST NORTH OF KRWL LATE THIS EVENING. LATEST HRRR FORECAST RADAR SHOWS THIS ACTIVITY DISSIPATING IN A FEW HOURS. MOISTURE FROM THE 4 CORNERS AREA FORECAST TO MOVE NORTH INTO SOUTH CENTRAL WYOMING THIS AFTERNOON. COULD SEE PREDOMINANT SHOWERS AND ISOLATED THUNDERSTORMS AT KRWL AND KLAR AFTER 20Z OR SO...PERSISTING INTO THE EVENING HOURS. && .FIRE WEATHER... ISSUED AT 300 AM MDT WED AUG 26 2015 MINIMAL CONCERNS THROUGH FRIDAY. HOWEVER...ON SATURDAY...HUMIDITIES AND WINDS WILL APPROACH CRITICAL LEVELS OVER OUR NORTHERN AND WESTERN COUNTIES...THUS ELEVATING CONCERNS. EARLY NEXT WEEK...MONDAY THROUGH WEDNESDAY...WE MAY HAVE A PROLONGED CRITICAL FIRE WEATHER PERIOD DUE TO INCREASED WINDS AND LOW HUMIDITIES IN THE AFTERNOONS AND EVENINGS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...RUBIN LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1050 PM MDT TUE AUG 25 2015 .UPDATE... ISSUED AT 841 PM MDT TUE AUG 25 2015 RAISED POPS UP TO 20 PERCENT FOR WIDELY SCATTERED SHOWERS AND A FEW TSTORMS ALONG AND WEST OF THE LARAMIE RANGE THROUGH LATE THIS EVENING BEFORE DISSIPATING. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 222 PM MDT TUE AUG 25 2015 BROAD UPPER-LEVEL RIDGING EXTENDS ACROSS THE WESTERN HALF OF THE US THIS AFTERNOON. THE RESULTING LARGE SCALE SUBSIDENCE IS CONTRIBUTING TO GENERALLY WARM AND DRY CONDITIONS ACROSS THE CWA. RECENT WATER VAPOR SATELLITE IMAGERY SHOWS A PLUME OF MONSOONAL MOISTURE LIFTING NORTH OVER THE FOUR CORNERS REGION ON THE WEST SIDE OF THE RIDGE. SOME OF THIS MOISTURE WAS ALREADY CREEPING INTO THE SNOWY AND SIERRA MADRE MTNS AT 20Z...SO WE SHOULD SEE AN INCREASE IN MOUNTAIN CONVECTION AS WE HEAD INTO THE LATE AFTERNOON/EVENING HOURS. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS STILL EXPECTED FROM WED AFTN THROUGH THU WITH THE PASSAGE OF A STRONG PACIFIC COLD FRONT AND VIGOROUS MID-LEVEL SHORT WAVE TROUGH. NAM/GFS/ECMWF ALL SUGGEST THE GREATEST PRECIP COVERAGE ALONG AND WEST OF THE LARAMIE RANGE...WITH MAKES SENSE WITH GENERAL WESTERLY FLOW AND THE TRAJECTORY OF THE BEST H7-H3 MOISTURE. BETTER CHANCES FOR THE EASTERN PLAINS SHOULD COME AFTER 15Z THU AS MOST OF THE MID LEVEL ENERGY AND ASSOCIATED MOISTURE PLUME SHIFTS SLOWLY TO THE EAST. ONE MORE WARM DAY EXPECTED FOR WED PRE-FROPA. MUCH COOLER FOR THU AS MOST OF THE MODELS SHOW H7 TEMPS PLUNGING FROM +16 C AT 00Z THU...TO BETWEEN +8 AND +10 C BY 18Z THU. INDEED AN IMPRESSIVE TEMPERATURE SWING FOR A PACIFIC FRONT...ESPECIALLY FOR AUGUST. MAY NEED TO REVISE TEMPERATURES DOWNWARD IN THE FUTURE IF IT LOOKS LIKE PRECIP WILL BE HEAVIER OR MORE WIDESPREAD. .LONG TERM...(THURSDAY THROUGH NEXT TUESDAY) ISSUED AT 222 PM MDT TUE AUG 25 2015 MEDIUM TO LONG RANGE MODELS ARE CONSISTENT WITH THE PREVIOUS 12Z AND 00Z RUNS...SHOWING UPPER LEVEL RIDGING BUILDING BACK INTO THE FRONT RANGE ON FRIDAY. THIS RIDGE WILL GRADUALLY EXTEND EASTWARD INTO THE GREAT PLAINS...ALLOWING SOUTHWEST FLOW ALOFT TO INCREASE OVER WYOMING AND NEBRASKA. IT WILL BE WARM ON FRIDAY AND ESPECIALLY DURING THE WEEKEND WITH HIGHS IN THE 80S TO MID 90S...WARMEST OVER THE LOWER ELEVATIONS. MODELS ARE NOW SHOWING A BIT MORE MOISTURE AND INSTABILITY OVER THE REGION AS SOME SUBTROPICAL MOISTURE GRADUALLY ADVECTS NORTHWARD ON THE WESTERN SIDE OF THE UPPER LEVEL RIDGE AXIS. THE 12Z ECMWF SHOWS SOME SHORTWAVE ENERGY PUSHING NORTHEAST OVER THE FORECAST AREA BY EARLY NEXT WEEK...IMPROVING THUNDERSTORM CHANCES MONDAY AND TUESDAY. EXPECT MOST OF THIS ACTIVITY TO BE OVER THE MOUNTAINS...ALONG AND WEST OF THE I25 CORRIDOR...BUT A FEW THUNDER SHOWERS MAY PUSH FAR ENOUGH EAST TO IMPACT WESTERN NEBRASKA AS WELL. INCREASED POP BETWEEN 15 TO 25 PERCENT FOR WIDELY SCATTERED THUNDER ACROSS THE HIGH VALLEYS AND HIGH PLAINS EAST OF THE LARAMIE RANGE ACROSS SOUTHEAST WYOMING. DAYTIME TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL AND IN THE 80S TO LOW 90S ACROSS THE AREA EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1047 PM MDT TUE AUG 25 2015 GETTING SOME LIGHTNING STRIKES JUST NORTH OF KRWL LATE THIS EVENING. LATEST HRRR FORECAST RADAR SHOWS THIS ACTIVITY DISSIPATING IN A FEW HOURS. MOISTURE FROM THE 4 CORNERS AREA FORECAST TO MOVE NORTH INTO SOUTH CENTRAL WYOMING THIS AFTERNOON. COULD SEE PREDOMINANT SHOWERS AND ISOLATED THUNDERSTORMS AT KRWL AND KLAR AFTER 20Z OR SO...PERSISTING INTO THE EVENING HOURS. && .FIRE WEATHER... ISSUED AT 222 PM MDT TUE AUG 25 2015 WARM AND DRY CONDITIONS ARE OCCURRING ACROSS A LARGE PORTION OF THE AREA THIS AFTERNOON. RELATIVE HUMIDITY VALUES BETWEEN 10 AND 15 PCT ARE COMMON ACROSS SOUTHEAST WYOMING...BUT LIGHT WINDS TOPPING OUT AROUND 10 MPH IN THE VEDAUWOO AREA ARE KEEPING CONCERNS MINIMAL. THERE WILL NOT BE ANY FIRE WEATHER CONCERNS THROUGH THE END OF THE WORK WEEK AS A COOLER AND MORE MOIST AIR MASS KEEPS HUMIDITIES ABOVE 20 PCT ALONG WITH A HIGHER PROBABILITY FOR WETTING RAINS. A WARMING AND DRYING TREND IS EXPECTED THIS WEEKEND ALONG WITH GUSTY WINDS. NEAR CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED FOR SAT AND SUN. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...MJ SHORT TERM...CLH LONG TERM...TJT AVIATION...GCC FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 PM MST THU AUG 27 2015 .SYNOPSIS...EXPECT DECREASED THUNDERSTORM ACTIVITY FRIDAY THEN SCATTERED THUNDERSTORMS WILL RETURN ESPECIALLY FROM TUCSON EAST AND SOUTH SATURDAY AND CONTINUE INTO NEXT WEEK. DAYTIME TEMPERATURES WILL REMAIN ABOVE AVERAGE INTO EARLY NEXT WEEK...THEN HIGH TEMPERATURES WILL TREND CLOSER TO NORMAL BY LATE NEXT WEEK. && .DISCUSSION...VERY INTERESTING EVENING AS MOST OF THE ACTIVITY HAS BEEN DRIVEN BY THUNDERSTORM OUTFLOW INTERACTIONS. ONE OF THE OUTFLOWS THAT STARTED IN EASTERN PINAL COUNTY EARLIER THIS EVENING HAS PUSHED S INTO NRN MEXICO. THERE WERE A FEW STRONG STORMS EARLY IN THE EVENING ESPECIALLY N OF ARIVACA AND ON SE SIDE OF TUCSON METRO AREA. SOUTH OF THE BORDER ACROSS NORTHERN SONORA THERE WAS AN MCS. NORTH BOUND OUTFLOWS FROM THIS SYSTEM WILL LIKELY INTERACT WITH SOUTH OF OUTFLOWS THAT PUSHED ACROSS THE INTERNATIONAL BORDER FOR THE POSSIBILITY OF NEW THUNDERSTORM DEVELOPMENT SOUTH OF THE BORDER. THESE STORMS CAN THEN SEND OUTFLOWS NORTH INTO COCHISE COUNTY FOR NEW STORM DEVELOPMENT OVERNIGHT. LATEST HRRR RUN HINTING AT THIS. WILL RUN. ON THE EVENING UPDATE WILL INCREASE POPS OVERNIGHT ALONG THE INTERNATIONAL BORDER. CHECK PREVIOUS DISCUSSION BELOW FOR THE REMAINDER OF THE FORECAST. && .AVIATION...VALID THRU 29/00Z. ISOLD-SCTD -TSRA/-SHRA...MAINLY S AND E OF KTUS THRU 28/12Z. ISOLD TO PERHAPS SCTD -TSRA/-SHRA WILL THEN PREVAIL MAINLY E OF KTUS FRI AFTN. MVFR CONDS AND BRIEF WIND GUSTS OF 35-45 KTS WILL OCCUR WITH THE STRONGER T-STORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 10-15K FT AGL AND SURFACE WIND WILL MAINLY BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...THUNDERSTORMS WILL BE LIMITED TO MAINLY NEAR THE MOUNTAINS EAST OF TUCSON FRIDAY. SCATTERED THUNDERSTORMS WILL RETURN TO MUCH OF SOUTHEAST ARIZONA SATURDAY...THEN SCATTERED THUNDERSTORMS WILL PREVAIL MAINLY FROM TUCSON EAST AND SOUTH SUNDAY THROUGH THURSDAY. BRIEF STRONG...GUSTY AND ERRATIC WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS. OTHERWISE...GENERALLY LIGHT TERRAIN DRIVEN WINDS WILL OCCUR INTO NEXT WEEK. && .PREV DISCUSSION...MARKEDLY LESS COVERAGE OF SHOWERS/TSTMS IS ON TAP FRI AFTERNOON AS HIGH PRESSURE ALOFT BECOMES CENTERED OVER THE AREA. SOME MESOSCALE MODELS SUGGEST THAT ANY THUNDERSTORMS THAT OCCUR FRI AFTERNOON/EVENING WILL BE CONFINED ONLY NEAR MOUNTAINS EAST OF TUCSON. FOR NOW...HAVE OPTED FOR ISOLATED TO SCATTERED SHOWERS/TSTMS MAINLY FROM TUCSON EWD TO THE NEW MEXICO BORDER FRI AFTN/EVENING. THE UPPER HIGH IS PROGGED TO REMAIN QUASI-STATIONARY OVER THE AREA SAT. HOWEVER...HAVE ADJUSTED POPS UPWARD FAIRLY SUBSTANTIALLY ACROSS MUCH OF THE AREA AS MODELS SUGGEST THAT A GENERALLY NELY STEERING FLOW REGIME MAY DEVELOP. THUS...SCATTERED SHOWERS/TSTMS ARE EXPECTED TO OCCUR ACROSS MUCH OF THIS FORECAST AREA SAT AFTERNOON/EVENING. THEREAFTER...THE MID-LEVEL STEERING FLOW IS PROGGED TO BECOME SWLY SUN AND CONTINUE INTO THURSDAY AS UPPER RIDGE AXIS WILL BE OVER THE CENTRAL/SRN CONUS PLAINS...AND AN UPPER TROUGH BECOMES ESTABLISHED YET AGAIN ADJACENT THE WEST COAST. THIS PATTERN SHOULD YIELD ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS SUN- THUR. ABOVE NORMAL DAYTIME TEMPERATURES WILL ALSO PREVAIL FRI THRU MON OR TUE...THEN HIGH TEMPS WILL TREND CLOSE TO SEASONAL NORMALS BY NEXT THUR. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON !--NOT SENT--!
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
339 AM EDT FRI AUG 28 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST TODAY. A LARGE AREA OF SURFACE HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL SLIDE EAST TO THE ATLANTIC COAST FOR THE WEEKEND. INCREASING ATMOSPHERIC MOISTURE WILL DRIFT NORTH INTO OUR REGION THIS WEEKEND. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN FLORIDA ON SUNDAY. REFER TO THE LATEST ADVISORY ON ERIKA ISSUED BY THE NATIONAL HURRICANE CENTER. && .NEAR TERM /THROUGH TODAY/... EARLY THIS MORNING...LOW CLOUDS HAVE BEGUN TO DEVELOP EARLY THIS MORNING...ESPECIALLY ACROSS THE WESTERN HALF OF THE FORECAST AREA GIVEN DRY AIR ALOFT. OVERNIGHT LOWS WILL ONCE AGAIN RANGE FROM THE MID 60S TO THE LOWER 70S. TODAY...AN UPPER LEVEL TROUGH EXTENDING FROM THE OHIO RIVER VALLEY TO THE GULF OF MEXICO WILL WEAKEN AND LIFT NORTH TODAY. THE FRONTAL BOUNDARY IS EXPECTED TO REMAIN STALLED NEAR THE COAST. SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM THE NORTH PRODUCING NORTHEASTERLY/EASTERLY FLOW. MODELS SHOW A STRONG GRADIENT IN PRECIPITABLE WATER FROM NORTH TO SOUTH ACROSS THE AREA WITH THE BEST MOISTURE SOUTH. MODEL SOUNDINGS SHOW WEAK INSTABILITY. THE HRRR AND 00Z SPC WRF SHOW ISOLATED COVERAGE. SLIGHT CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS APPROPRIATE. HIGH TEMPERATURES ARE FORECAST NEAR NORMAL...IN THE UPPER 80S. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... MAY STILL HAVE AN ISOLATED LINGERING SHOWER/STORM UNTIL MIDNIGHT...THEN DRY FOR ALL AREAS THE REMAINDER OF THE NIGHT. MOISTURE WILL BEGIN TO INCREASE ACROSS THE SOUTHERN PORTIONS OF THE CWA SATURDAY. THIS MOISTURE INCREASE IS EXPECTED TO REMAIN CONFINED TO THE SOUTH THROUGH THE DAY...WITH NORTHERN COUNTIES STILL HAVING DRIER AIR IN PLACE. THIS WOULD LEAD TO THE BEST RAIN CHANCES BEING ACROSS THE SOUTH AND SOUTH-CENTRAL COUNTIES ON SATURDAY...WITH THE NORTHERN COUNTIES DRY OR ONLY HAVING AN ISOLATED SHOWER/STORM. TEMPERATURES IN THE MIDDLE TO UPPER 60S TONIGHT WITH THE DRIER AIR. SATURDAY WILL SEE HIGHS IN THE UPPER 80S. LOWS SATURDAY NIGHT MODERATE SLIGHTLY WITH THE MOISTURE INCREASE...WITH READINGS AROUND 70. && .LONG TERM /SUNDAY THROUGH THURSDAY/... UPPER TROUGH WILL REMAIN TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED TO OUR E AND SE. THIS WILL CONTINUE TO DRAW MOISTURE NORTHWARD INTO OUR REGION SUNDAY. EXPECTING TO HAVE CONTINUED DIURNAL CONVECTION SUNDAY INTO TUESDAY WITH THIS PATTERN. EARLY TO MID NEXT WEEK...MODELS MAINTAIN WEAK UPPER TROUGH TO OUR WEST AND UPPER RIDGE TO OUR E AND SE. MAIN CONCERN FOR THIS TIME PERIOD WILL BE THE EVENTUAL TRACK AND STRENGTH OF TROPICAL CYCLONE ERIKA AS IT APPROACHES THE ATLANTIC COASTLINE. LATEST OFFICIAL FORECAST FROM NHC BRINGS IT NW TOWARDS THE FLORIDA EAST COAST BY LATE SUNDAY INTO EARLY TUESDAY...STRENGTHENING IT TO A LOW END HURRICANE. THERE CONTINUES TO BE LITTLE RUN TO RUN CONSISTENCE WITH THE LONGER RANGE MODELS...ESPECIALLY WITH THE TRACK...AND WITH THE LARGE MODEL SPREAD...CONFIDENCE IS LOW OUT IN THE LONG TERM. PLEASE SEE THE NHC FORECAST FOR LATEST DISCUSSION AND TRACK OF ERIKA. FOR NOW...DUE TO UNCERTAINTIES REGARDING IMPACT FOR OUR AREA...WILL CONTINUE TO MAINTAIN CHANCE POPS. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... NOCTURNAL COOLING AND LOW-LEVEL MOISTURE SHOULD LEAD TO STRATUS AND FOG EARLY THIS MORNING. STRATUS IS FAVORED INSTEAD OF FOG BECAUSE OF WIND. HEATING AND MIXING SHOULD BRING IMPROVEMENT DURING THE DAY. LEANED TOWARD THE SLOWER NAM MOS TIMING BECAUSE THIS GUIDANCE DID BETTER THE PREVIOUS DAY. ANOTHER SLIGHT CHANCE OF DIURNAL CONVECTION AT THE TERMINALS THIS AFTERNOON/EVENING...ALTHOUGH CONFIDENCE REMAINS TOO LOW TO INCLUDE IN CURRENT ISSUANCE. WINDS WILL CONTINUE OUT OF THE NORTHEAST/EAST TODAY AT 10 KNOTS OR LESS. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
312 AM EDT FRI AUG 28 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST TODAY. A LARGE AREA OF SURFACE HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION WILL SLIDE EAST TO THE ATLANTIC COAST FOR THE WEEKEND. INCREASING ATMOSPHERIC MOISTURE WILL DRIFT NORTH INTO OUR REGION THIS WEEKEND. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN FLORIDA ON SUNDAY. REFER TO THE LATEST ADVISORY ON ERIKA ISSUED BY THE NATIONAL HURRICANE CENTER. && .NEAR TERM /THROUGH TODAY/... EARLY THIS MORNING...LOW CLOUDS HAVE BEGUN TO DEVELOP EARLY THIS MORNING...ESPECIALLY ACROSS THE WESTERN HALF OF THE FORECAST AREA GIVEN DRY AIR ALOFT. OVERNIGHT LOWS WILL ONCE AGAIN RANGE FROM THE MID 60S TO THE LOWER 70S. TODAY...AN UPPER LEVEL TROUGH EXTENDING FROM THE OHIO RIVER VALLEY TO THE GULF OF MEXICO WILL WEAKEN AND LIFT NORTH TODAY. THE FRONTAL BOUNDARY IS EXPECTED TO REMAIN STALLED NEAR THE COAST. SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM THE NORTH PRODUCING NORTHEASTERLY/EASTERLY FLOW. MODELS SHOW A STRONG GRADIENT IN PRECIPITABLE WATER FROM NORTH TO SOUTH ACROSS THE AREA WITH THE BEST MOISTURE SOUTH. MODEL SOUNDINGS SHOW WEAK INSTABILITY. THE HRRR AND 00Z SPC WRF SHOW ISOLATED COVERAGE. SLIGHT CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS APPROPRIATE. HIGH TEMPERATURES ARE FORECAST NEAR NORMAL...IN THE UPPER 80S. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... MODELS CONTINUE TO INDICATE MAIN UPPER TROUGH JUST TO OUR WEST WILL GRADUALLY WEAKEN AND LIFT NORTH THROUGH THE PERIOD...LEAVING BEHIND A WEAK CUT OFF LOW NEAR THE NORTHERN GULF OF MEXICO...WHILE UPPER RIDGE OVER THE WESTERN ATLANTIC BEGINS TO BUILD WESTWARD TOWARDS THE SE COAST. THIS IS EXPECTED TO LEAD TO BAND OF BETTER MOISTURE AND OLD SURFACE BOUNDARIES CURRENTLY TO OUR SOUTH TO GRADUALLY DRIFT NORTH INTO OUR REGION SATURDAY. MAIN DIFFERENCE WITH LATEST MODEL RUNS IS A LITTLE SLOWER TIMING WITH MOISTURE INCREASE...AND MAINLY RELEGATING BEST MOISTURE TO THE S AND W FA...AND MAINTAINING RELATIVELY DRY AIR OVER THE N FA...AS SURFACE HIGH REMAINS ANCHORED OVER THE MID ATLANTIC RIDGING INTO THE WESTERN CAROLINAS. && .LONG TERM /SUNDAY THROUGH THURSDAY/... UPPER TROUGH WILL REMAIN TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED TO OUR E AND SE. THIS WILL CONTINUE TO DRAW MOISTURE NORTHWARD INTO OUR REGION SUNDAY. SO...WILL MAINTAIN TREND TOWARDS INCREASING POPS. EARLY TO MID NEXT WEEK...MODELS MAINTAIN WEAK UPPER TROUGH TO OUR WEST AND UPPER RIDGE TO OUR E AND SE. MAIN CONCERN FOR THIS TIME PERIOD WILL BE TROPICAL CYCLONE ERIKA. LATEST OFFICIAL FORECAST FROM NHC BRINGS IT NW TOWARDS THE FLORIDA EAST COAST BY LATE SUNDAY INTO EARLY TUESDAY...STRENGTHENING IT TO A LOW END HURRICANE. GENERAL MODEL CONSENSUS HAS IT DRIFTING TO THE NORTH OR NE THEREAFTER. FOR NOW...DUE TO UNCERTAINTIES REGARDING IMPACT FOR OUR FA...WILL CONTINUE TO MAINTAIN CHANCE POPS. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... NOCTURNAL COOLING AND LOW-LEVEL MOISTURE SHOULD LEAD TO STRATUS AND FOG EARLY THIS MORNING. STRATUS IS FAVORED INSTEAD OF FOG BECAUSE OF WIND. HEATING AND MIXING SHOULD BRING IMPROVEMENT DURING THE DAY. LEANED TOWARD THE SLOWER NAM MOS TIMING BECAUSE THIS GUIDANCE DID BETTER THE PREVIOUS DAY. ANOTHER SLIGHT CHANCE OF DIURNAL CONVECTION AT THE TERMINALS THIS AFTERNOON/EVENING...ALTHOUGH CONFIDENCE REMAINS TOO LOW TO INCLUDE IN CURRENT ISSUANCE. WINDS WILL CONTINUE OUT OF THE NORTHEAST/EAST TODAY AT 10 KNOTS OR LESS. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
323 AM CDT FRI AUG 28 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 249 AM CDT FRI AUG 28 2015 Early this morning an upper trough extended from northwest IA southwest across central KS. Ascent ahead of the trough axis combined with isentropic lift above 850mb level was causing numerous showers and isolated thunderstorms across the western and northern counties of the CWA. MUCAPES were only around 500 J/KG, thus the elevated thunderstorms will remain rather weak through the morning hours. The scattered to numerous showers along with isolated elevated thunderstorms will continue to move east across northeast and east central KS through the morning hours. We may see a break in the showers and thunderstorms during the early afternoon hours as the stronger isentropic lift shifts northeast into northern MO and eastern IA. A second H5 trough will dig southeast across eastern KS later this afternoon along with a surface cold front located across central NE and northwest KS. As the surface front pushes southeast across northeast and east central KS, scattered showers and thunderstorms will develop along the surface front. There may even be some post frontal showers and thunderstorms due to the stronger ascent ahead of the H5 trough digging southeast on the back side of a developing closed upper low across northeast IA and southeast MN. If we see some insolation then MLCAPES may increase to around 1500 J/KG. The sfc to 6 KM effective shear will remain rather weak, under 20 KTS, through the day as the low-level flow veer to the southwest ahead of the surface cold front. There could be a few strong storms that may produce small hail and gusty winds if the atmosphere destabilizes ahead of the surface front. The surface front and H5 trough will pass southeast of the CWA after 6Z. There could be a few lingering showers northwest of the front across the extreme southeast counties through the early morning hours of Saturday but these showers should shift southeast of the CWA before 12Z SAT. Highs Today will be dependent on the degree of insolation. If we remain cloudy through the day then highs may only reach the upper 70s to lower 80s. Areas that see more insolation may reach the mid 80s. Tonight lows will drop into the lower to mid 60s. .LONG TERM...(Saturday THROUGH Thursday) ISSUED AT 249 AM CDT FRI AUG 28 2015 Saturday...Weak shortwave trough drifts slowly off to the southeast, ending precip chances in east central KS, although some clouds could linger in that area through Saturday night. Saturday night through Sunday night...Upper ridge builds east during this time as previously mentioned remnant vort max weakens over the Ozark area. Would expect dry conditions through this time period...although isolated showers could form in southeast KS, with a small chance they could affect areas mainly south of I35. Monday through Tuesday night...Upper ridge is flattened by a shortwave trough that moves from the central Rockies to the Upper Midwest. Main dynamics/lift with this trough should be to our north but both GFS and ECMWF do develop QPF in north central/far northeast KS Tuesday night. Have added low POPS for that area overnight. Wednesday through Thursday...Behind this trough, persistent low- level warm advection helps build upper ridge back over the eastern Plains into the Upper Midwest, with seasonably warm max temperatures expected to be in the lower 90s each day. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT) ISSUED AT 1152 PM CDT THU AUG 27 2015 Area of showers and thunderstorms over north central KS late this evening should move east through northeast Kansas through Friday morning. Preferred the latest HRRR and 00Z 12KM NAM concerning the movement of the precipitation. Given the limited instability, precipitation will likely be showers with embedded thunderstorms so forecasted showers at KTOP/KFOE. 00z NAM sounding for Friday afternoon suggest surface based thunderstorms are possible as weak boundary approaches. Kept VCTS for this possibility. Otherwise, VFR conditions. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...GDP AVIATION...Johnson
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1200 AM CDT FRI AUG 28 2015 ...Update to aviation forecast discussion... .SHORT TERM...(THIS EVENING THROUGH Friday) ISSUED AT 242 PM CDT THU AUG 27 2015 Thunderstorm chances and degree of strength remain the challenges in the short term. Morning convection out east provided a robust outflow boundary that continues to reinforce in the east and advance into south central Kansas at this hour. Clouds have also lessened instability to the east, while elevated weak echoes have started to develop out ahead of the surface low in southwest nebraska into NW Kansas. True surface front appears to be just through Goodland with dryline extending to the SSE, and a weak prefrontal trof having become commingled with the outflow across the central part of the state. Clouds and outflow has likely impacted surface based instability, although lapse rates aloft remain steep above the warm nose. For the evening hours, expect weak echoes to continue to develop over Central Kansas and move eastward with most activity remaining east of Manhattan through midnight. CAPE dissipates quickly as the evening progresses, and wind shear remains on the low end around 30kts 0-6km. NAM soundings suggest some help from LLJ in getting storms started overnight, and along with the weakly defined front moving through the area, should bring storms through overnight and into Friday afternoon. A few of the storms could be severe, but think SPC outlook keeping marginal threat in the northwest part of our area is a good representation. Lows tonight with clouds and precip remain around 70, with highs tomorrow in the low to middle 80s. .LONG TERM...(Friday NIGHT THROUGH Thursday) ISSUED AT 242 PM CDT THU AUG 27 2015 Friday night through Sunday By Friday evening, sfc frontal boundary is similar with guidance positioning southwest to northeast over east central areas of the CWA. While subsidence increases behind the trough over north central areas, it is possible scattered convection could continue to develop along the boundary. Weak instability above 850 mb and 0-6 km bulk shear up to 20 kts precludes widespread severe storms from developing. Otherwise cloud cover will gradually clear behind the wave Saturday morning with lows starting out in the upper 50s and low 60s. Light cool advection from the north during the afternoon keeps temps cooler than previous days in the 80s. High pressure continues to build in through Sunday as highs gradually modify back into the upper 80s and lower 90s for Sunday. No major changes were made to this period. Upper flow will become amplified with organized westerlies forecast to remain displaced well NW of northeast Kansas. As a result...do not expect any fronts to approach/pass through the area and any high plains storms should remain west/northwest of the area given weak flow. In a nutshell, the extended looks dry for the most part and warm with stubborn ridge expected to remain just east of the state keeping any eastward progression of the west coast trough limited. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT) ISSUED AT 1152 PM CDT THU AUG 27 2015 Area of showers and thunderstorms over north central KS late this evening should move east through northeast Kansas through Friday morning. Preferred the latest HRRR and 00Z 12KM NAM concerning the movement of the precipitation. Given the limited instability, precipitation will likely be showers with embedded thunderstorms so forecasted showers at KTOP/KFOE. 00z NAM sounding for Friday afternoon suggest surface based thunderstorms are possible as weak boundary approaches. Kept VCTS for this possibility. Otherwise, VFR conditions. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...67 LONG TERM...Bowen/Omitt AVIATION...Johnson
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
207 AM EDT FRI AUG 28 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 411 PM EDT THU AUG 27 2015 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW WNW FLOW INTO THE UPPER GREAT LAKES. RIDGE THAT EXTENDED FROM THE SRN ROCKIES TO SCNTRL CANADA YESTERDAY IS WEAKENING DUE TO SHORTWAVE ENERGY TRACKING FROM NRN ALBERTA TO NRN MANITOBA AND ANOTHER SHORTWAVE MOVING FROM WY INTO THE WRN PLAINS. THAT SHORTWAVE WILL BEGIN TO BECOME A FCST ISSUE HERE ON FRI. AFTER MORNING FOG...THE DAY HAS TURNED MOSTLY SUNNY...THOUGH AN ELEVATED SMOKE LAYER HAS LEFT THE SKY WITH A HAZY APPEARANCE. TEMPS HAVE REBOUNDED INTO THE MID 60S TO LWR 70S. QUIET WEATHER WILL CONTINUE TONIGHT AS DRY AIR IN A RELATIVE SENSE DOMINATES MOST OF THE COLUMN. LIGHT SOUTHERLY WINDS AND AN INCREASE IN PRECIPITABLE WATER WILL RESULT IN A WARMER NIGHT THAN LAST NIGHT. EXPECT MINS MOSTLY IN THE 50S...THOUGH DOWNSLOPE AREAS NEAR LAKE SUPERIOR MAY NOT FALL BLO 60F. ON FRI...THE WRN PLAINS SHORTWAVE WILL MOVE TO WI. BEST WAA/ISENTROPIC ASCENT ASSOCIATED WITH FEATURE SHIFTS FROM NRN IA/SRN MN INTO WI...SO BULK OF PCPN WILL PASS BY TO THE S OF HERE. THAT AREA IS ALSO WHERE MODELS SHOW HEAVIEST PCPN. PCPN CHANCES WILL BE MUCH MORE LIMITED TO THE N. WHILE HIGH RES WRF-ARW/NMM ARE LIKELY TOO AGGRESSIVE IN SPREADING PCPN INTO SCNTRL UPPER MI FRI...MOST MODELS DO BRING SOME PCPN INTO THE SCNTRL IN THE AFTN. WILL PAINT CHC POPS OVER THE FAR SCNTRL. DEPENDING ON CLOUD COVER/DAYTIME HEATING...THE GFS AND ESPECIALLY NAM BUILD A LITTLE BIT OF INSTABILITY PER MLCAPES FARTHER N. HAVE INCLUDED SCHC POPS FOR -SHRA IN THE EVENT A FEW -SHRA MANAGE TO POP IN THE AFTN. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 301 PM EDT THU AUG 27 2015 PLENTY OF UNCERTAINTY IN THE FIRST 24 HOURS OF THE LONG TERM...FRI NIGHT AND SAT. A SHORTWAVE IS SET TO MOVE OUT OF THE CENTRAL PLAINS AND MOVE THROUGH OR NEAR THE REGION DURING THIS TIME. THE 00Z/27 ECMWF IS DEEPEST AND FARTHEST NORTH WITH THE SHORTWAVE...WITH RAIN OVER MOST OF THE CWA. THE 12Z/27 GFS IS QUITE A BIT WEAKER AND FARTHER S...KEEPING MOST OF THE CWA DRY. THE 12Z/27 GEM AND 12Z/27 NAM MATCH CLOSER TO THE GFS...BUT DO BRING SOME PRECIP INTO THE SRN CWA. WILL TEND TO FAVOR A GFS/NAM/GEM CONSENSUS GIVEN HOW MUCH OF AN OUTLIER THE ECMWF IS. THIS RESULTS IN CHANCE POPS OVER SCENTRAL UPPER MI FRI NIGHT AND SAT MORNING AND SLIGHT CHANCE POPS ELSEWHERE. DRY CONDITIONS EXPECTED BY 00Z SUN. MODELS CONTINUE TO BUILD AN UPPER RIDGE OVER THE REGION FROM SUN THROUGH THE REST OF NEXT WEEK. RAIN CHANCES WILL BE MINIMAL...BUT COULD SEE SOME CONVECTION WED OR THU IF SHORTWAVE ENERGY CAN ROUND THE TOP OF THE RIDGE...BUT CHANCES ARE LOW. THE AIRMASS WILL BE ON THE RISE...HOVERING AROUND 20C FROM LATE MON THROUGH THE REST OF THE WEEK. THIS RESULTS IN TEMPS BEING 10 OR MORE DEGREES ABOVE NORMAL FROM MON ON. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 207 AM EDT FRI AUG 28 2015 RELATIVELY DRY AIR MASS OVER THE AREA SHOULD ENSURE VFR CONDITIONS CONTINUE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 PM EDT THU AUG 27 2015 A GENERALLY WEAK PRES GRADIENT WILL DOMINATE THE UPPER LAKES INTO EARLY NEXT WEEK. ON MOST DAYS...WINDS WILL BE UNDER 15KT...BUT THERE WILL BE SOME PERIODS WHERE GUSTS WILL GET INTO THE 15-20KT RANGE. LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE WEEKEND WITH HIGH PRES RIDGE MORE FIRMLY IN CONTROL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
305 AM CDT FRI AUG 28 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 305 AM CDT FRI AUG 28 2015 PCPN CHANCES TODAY AND THEN TEMPERATURES THE NEXT FEW DAYS WILL BE THE MAIN FORECAST CONCERNS. FAIRLY WIDESPREAD AREA OF SHRA AND TSRA WILL CONTINUE TO MOVE EAST THIS MORNING...ASSOCIATED WITH SHORTWAVE TROUGH MOVING THROUGH THE REGION. WATER VAPOR SATELLITE IMAGERY LOOP IN COMBINATION WITH RECENT 500 MB RUC MODEL INITIALIZATIONS SHOWED A FAIRLY STRONG WAVE FOR THIS TIME OF YEAR. 12 HOUR HEIGHT FALLS AT 500 MB WERE UP TO ABOUT 50 METERS. ATMOSPHERE WAS ALSO QUITE MOIST. 700 MB DEWPOINTS OF 4-8 DEGREES C WERE NOTED FROM THE DESERT SW UP INTO WRN KS AND SWRN NE AT 00Z LAST EVENING...AND FORECAST SOUNDINGS SUGGEST PW VALUES ARE AROUND 2 INCHES OR MORE EARLY THIS MORNING. ALTHOUGH THE STRONGEST AREA OF LIFT AND HIGHEST MOISTURE WILL BE SHIFTING EAST OF THE LOCAL AREA...KEPT SOME POPS GOING MUCH OF THE DAY. A WEAKER AREA OF LIFT SHOULD SPREAD SEWD OVER THE REGION AND FORECAST SOUNDINGS STILL SHOW SOME INSTABILITY. WILL KEEP RAIN CHANCES MAINLY AT 20-30 PERCENT AFTER EARLY MORNING ACTIVITY ENDS. RECENT HRRR RUNS AND EVEN THE 00Z NAM SUGGEST PREVIOUS SCENARIO... WITH AT LEAST ISOLD SHRA/TSRA POSSIBLE. LINGERED A SLIGHT CHANCE OF TSRA IN OUR FAR SERN ZONES EARLY THIS EVENING...THEN IT SHOULD BE MAINLY DRY THROUGH SUNDAY. KEPT SOME MENTION OF FOG TONIGHT WITH LIGHT WINDS AND BOTH GFS MOS AND NAM MOS SUGGESTING AT LEAST PATCHY FOG LATE TONIGHT INTO SAT MORNING. DID NOT MENTION FOG SATURDAY NIGHT...BUT SFC RIDGE AXIS WILL BE CLOSE TO THE AREA AND WILL NEED TO MONITOR. RETURN FLOW WITH S/SE SFC WINDS SHOULD THEN STRENGTHEN SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 305 AM CDT FRI AUG 28 2015 MID LEVEL RIDGE EXTENDING FROM NWRN MEXICO UP INTO THE CNTRL PLAINS AND A TROUGH FROM WRN CANADA INTO THE NWRN UNITED STATES WILL BE THE MAIN FEATURES AT THE START OF THIS PERIOD. RIDGE WILL SLIDE SLOWLY SEWD AS THE TROUGH TO THE NORTHWEST DIGS. WEAK RIPPLES MOVING NEWD THROUGH THE REGION COULD BRING SOME TSRA...WITH BEST CHANCES BEING TUE NIGHT AND AGAIN THU NIGHT. TEMPERATURES SHOULD BE AT OR ABOVE NORMAL OVER THE AREA FOR MOST OR ALL OF NEXT WEEK. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1127 PM CDT THU AUG 27 2015 RADAR MOSAIC TREND THE LAST FEW HOURS REVEALING THAT AREAL COVERAGE INCREASE MAINLY OVER NERN AND EAST-CENTRAL NEB THIS MORNING REVOLVING AROUND SFC LOW SITUATED IN SERN NEB. AT THIS POINT EXPECT ACTIVITY TO CONTINUE AT ALL TERMINALS THRU AT LEAST 10Z THIS MORNING. AFT 10Z...CONDITIONS AT KOFK DETERIORATE TO MVFR/IFR TERRITORY THRU ABOUT MID MORNING. AS FOR KOMA/KLNK...HAVE TEMPO GROUPS IN PLACE TO TSRA ACTIVITY BTWN 06Z-10Z. THEREAFTER...VFR CONDITIONS SHOULD PREVAIL AT BOTH TAF SITES. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...DEE
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1249 AM EDT FRI AUG 28 2015 .SYNOPSIS... A STATIONARY FRONT OFF THE COAST WILL DRIFT SLOWLY EAST THROUGH THE WEEKEND AS WEAK HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH. TROPICAL CYCLONE ERIKA IS FORECAST TO BE IN THE VICINITY OF THE SOUTHEAST COAST EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1245 AM FRIDAY...HAVE ADJUSTED POPS DOWN AS MOST OF THE ACTIVITY IS NOW OFFSHORE. WILL KEEP JUST A SLIGHT CHANCE OF PRECIPITATION ALONG THE COAST OVERNIGHT. REST OF FORECAST IN PRETTY GOOD SHAPE. MID/HIGH CLOUDS WILL CONTINUE TO PREVAIL OVERNIGHT WITH LOW TEMPERATURE FORECAST IN THE MID 60S INLAND TO AROUND 70 LOOKING GOOD. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SATURDAY/... AS OF 240 PM THURSDAY...DEEPER MOISTURE WILL GRAD MOVE FURTHER E FRI AS HIGH PRES BUILDS CLOSER AND THE FRONT/LOW OFFSHORE MOVES FURTHER E. EXPECT DRY CONDITIONS INLAND WITH A SLIGHT CHC TO CHC POP IMD CST...ESPCLY EARLY. WITH MORE SUN INLAND SHLD SEE HIGHS AROUND 85 WITH LOWER 80S CST. && .LONG TERM /SATURDAY THROUGH FRIDAY/... AS OF 335 PM THURSDAY...WEAK ZONAL FLOW DEVELOPS FRIDAY WITH THE UPPER RIDGE OVER BERMUDA BUILDING WEST TOWARDS THE SOUTHEASTERN STATES. AT THE SURFACE, A WEAK FRONT WILL REMAIN STALL OFF THE NC COAST THROUGH SATURDAY. LITTLE CHANGE IN FORECAST REASONING BASED ON 12Z GUIDANCE THROUGH THE PERIOD. THE FRONTAL BOUNDARY AND DEEPEST MOISTURE REMAINS STALLED OFFSHORE THROUGH FRIDAY NIGHT AND WILL MAINTAIN DRY CONDITIONS INLAND TO SLIGHT CHANCE POPS FOR COASTAL SECTIONS. THE UPPER RIDGE ACROSS THE WESTERN ATLANTIC BUILDS WEST INTO THE SOUTHEAST FRIDAY THROUGH EARLY NEXT WEEK WHILE A ROBUST NORTHERN STREAM SHORTWAVE MOVES ACROSS THE MIDWEST INTO THE WEEKEND. A BROAD SHORTWAVE WILL LIFT NORTHEAST AROUND THE WESTERN PERIPHERY OF THE UPPER RIDGE SATURDAY NIGHT THROUGH SUNDAY, THOUGH WILL REMAIN FAR ENOUGH NORTH AND WEST OF THE REGION TO HAVE LITTLE IMPACT. AT THE SURFACE, HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO SATURDAY, THEN TRANSITION OFFSHORE WITH THE PIEDMONT TROUGH DEVELOPING SUNDAY THROUGH TUESDAY. WILL MAINTAIN SLIGHT CHANCE POPS FOR DIURNALLY DRIVEN, MAINLY ISOLATED, SHOWER/THUNDERSTORM PATTERN THROUGH THE WEEKEND AND INTO TUESDAY. TEMPERATURES WILL BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST. THE FORECAST FOR WEDNESDAY AND THURSDAY, DAY 7/8, IS PARTICULARLY TRICKY DUE TO THE UNCERTAINTY IN ANY TROPICAL IMPACTS FROM TROPICAL STORM ERIKA, CURRENTLY SOUTHEAST OF PUERTO RICO. WILL HEDGE TOWARDS A MODEL BLEND FOR THIS PERIOD WITH SLIGHT CHANCE POPS WEDNESDAY INCREASING TO CHANCE POPS THURSDAY, AS SURFACE FLOW SHIFTS SOUTHEASTERLY AND ABUNDANT MOISTURE OVERSPREADS EASTERN NC. THE FOCUS WILL BE ON THE TROPICS THIS WEEKEND AS THE NATIONAL HURRICANE CENTER HAS TROPICAL STORM ERIKA FORECAST TO MOVE INTO THE BAHAMAS. SIGNIFICANT UNCERTAINTY CONTINUES WITH REGARDS TO THE STRENGTH AND TRACK OF THE SYSTEM BEYOND DAY 3 WITH POOR RUN TO RUN CONSISTENCY IN THE MODELS, THUS IT IS TOO SOON TO SPECULATE AT THIS TIME WHAT IMPACTS MAY BE FELT ACROSS THE REGION NEXT WEEK. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 06Z SATURDAY/... AS OF 1245 AM FRIDAY...HAVE CONTINUED TREND OF VFR FORECAST THROUGH THE PERIOD. MID TO HIGH CLOUDS WILL PREVAIL OVERNIGHT AND WITH WEAK BOUNDARY LAYER MIXING DO NOT EXPECT MUCH IN THE WAY OF FOG OR STRATUS FORMATION OVERNIGHT. DRIER AIR ADVECTS INTO THE REGION FOR FRIDAY INTO FRIDAY NIGHT WITH VFR CONDITIONS PREVAILING. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 340 PM THURSDAY...PREDOMINANT VFR CONDITIONS EXPECTED THROUGH TUESDAY WITH ONLY ISOLATED, MAINLY DIURNALLY DRIVEN SHRA/TSRA. && .MARINE... SHORT TERM /THROUGH FRI/... AS OF 1245 AM FRIDAY...GUSTY NORTHEAST WINDS OVER THE PAMLICO SOUND AND SOME OF THE CENTRAL AND NORTHERN WATERS. THE HRRR AND RUC ARE PICKING UP WELL ON THESE WINDS AND HAVE USED A BLEND OF THESE WIND FIELDS FOR THE VERY NEAR TERM. SEAS CONTINUE IN THE 3 TO 5 FEET RANGE AND THIS SHOULD PERSIST OVERNIGHT. ON FRI THE HIGH BUILDS JUST TO THE N AS THE LOW/FRONT DRIFTS FURTHER E. THIS SHLD LEAD TO NE WINDS DIMINISHING TO 10 TO 15 KTS. THE PERSISTENT FETCH WILL KEEP SEAS 3 TO 5 FEET...HIGHEST OUTER WATERS. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 340 PM THURSDAY...THE HIGH WILL SHIFT OFF THE MID-ATLANTIC COAST FRIDAY NIGHT INTO SATURDAY WITH WINDS AROUND 15 KT OR LESS SATURDAY, DIMINISHING TO 10 KT OR LESS BY SUNDAY. WIND DIRECTION WILL GENERALLY BE NORTHEAST SATURDAY AND SUNDAY, VEERING SOUTHEAST SUNDAY NIGHT THEN SOUTH MONDAY INTO TUESDAY. WIND SPEEDS WILL BECOME LESS THAN 10 KT SUNDAY NIGHT THROUGH MONDAY NIGHT DUE TO WEAK PRESSURE GRADIENT ACROSS THE EASTERN NC COASTAL WATERS. SEAS WILL RANGE 2-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR THE OUTER CENTRAL WATERS. LOCAL SWAN/NWPS PERFORMING BETTER IN NORTHEAST WIND/SWELL CONDITIONS SATURDAY, THEN A GENERAL BLEND WITH WAVEWATCH FOR THE MEDIUM RANGE. MARINE INTERESTS SHOULD CONTINUE TO MONITOR THE DEVELOPMENT OF TROPICAL STORM ERIKA OVER THE WEEKEND, CURRENTLY LOCATED SOUTHEAST OF PUERTO RICO. SIGNIFICANT UNCERTAINTY REMAINS WITH REGARDS TO FORECAST TRACK AND INTENSITY BEYOND DAY 3. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RF NEAR TERM...CTC SHORT TERM...RF LONG TERM...DAG AVIATION...CTC/DAG MARINE...CTC/JBM/DAG/LEP
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
331 AM CDT FRI AUG 28 2015 .SHORT TERM... UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE- AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z. ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION... SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING PLAINS THROUGHOUT THE SHORT TERM PERIOD. STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE REGION. BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S. .LONG TERM... A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS. MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM AND HAVE KEPT MENTION OUT ATTM. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 87 61 89 61 / 20 20 10 0 TULIA 90 62 91 61 / 30 20 10 0 PLAINVIEW 89 63 91 63 / 30 30 10 0 LEVELLAND 93 64 91 64 / 30 30 10 10 LUBBOCK 94 65 92 65 / 30 30 10 0 DENVER CITY 93 63 91 63 / 20 30 10 0 BROWNFIELD 94 65 92 65 / 20 30 10 0 CHILDRESS 96 69 96 68 / 30 20 10 0 SPUR 98 69 94 67 / 20 20 10 10 ASPERMONT 100 72 97 70 / 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 29/07
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1000 AM EDT FRI AUG 28 2015 .Near Term [Through Today]... The 12Z TAE sounding showed quite an unstable environment with mid-level lapse rates of about 7 C/km and MUCAPE of over 2200 J/kg. This matches up well with the RUC forecast, which shows SBCAPE increasing to 2000-2500 J/kg over the next few hours. This morning`s sounding showed a PWAT of only 1.61", which is fairly dry for us this time of year, but 10-15 knot 1000-700 mb flow will help increase low level moisture through the day and is a favorable seabreeze pattern for widespread coverage of thunderstorms across the area. Local satellite and radar imagery show storms already active across our eastern coastal waters and making further inland progression than originally forecast this morning, so bumped up PoPs a bit through the remainder of the daylight hours. Lingering dry air in the mid-levels and moderate instability could combine to produce an environment somewhat favorable for downbursts. Isolated strong to severe storms will be possible with gusty winds the main threat. && .Prev Discussion [653 AM EDT]... .Short Term [Tonight Through Sunday]... An elongated area of +PV stretches from the Northeast, through the central Gulf of Mexico this morning. By tonight this area will split into two anomalies: a more progressive wave moving off the Northeast coast and what will be a quasi-stationary wave over the north-central Gulf. It won`t be until Saturday night through Sunday that this wave lifts through the Southeast. At the surface, ridging will prevail across much of the eastern half of the country. Locally, the ridge will be quite disturbed due to the upper wave. Steering flow will generally have a south or southeasterly component yielding a rather wet seabreeze regime across the entire Tri-State area. Like the ridge, the seabreeze will be far from ideal and enhanced by the upper level anomaly. Thus, PoPs will be higher than normal through the weekend (50-70%). High PoPs and plentiful cloud cover will keep afternoon highs anywhere from the mid 80s to around 90 degrees. Overnight lows will be in the middle 70s and not as pleasant as recent nights as moisture surges back into the region. .Long Term [Sunday Night Through Friday]... The main feature in the extended range forecast will be what is now Tropical Storm Erika. The eventual track will have a lot to do with how Erika holds together as it moves across Hispaniola today. The current track from NHC takes Erika south of the Bahamas before curving it north along the immediate east coast of Florida. A concerning trend in the dynamical models is a westward shift in the track. Both the 00z GFS and ECMWF bring Erika into the eastern Gulf, but diverge greatly with respect to timing. There has been a lot of back and forth between the dynamical models and a great deal of uncertainty still exists. But, the potential for at least some sort of impacts locally from Erika appears to be increasing over the past 24 hours. A track off the east coast of Florida will bring minimal rain impacts to the Tri-State region, while a track over the Peninsula will likely bring a great deal of rain over the Suwannee Valley, and a track into the eastern Gulf would mean the potential for both heavy rain and wind impacts area-wide. Due to the uncertainty in this forecast and the latest trends, close attention should be given to the forecast over the next couple of days. .Aviation... [Through 12Z Saturday] VFR conditions are expected this morning, with scattered to numerous showers and storms likely between 18Z and 03Z. These showers and storms may affect any of the terminals during that timeframe. This was handled in the TAFs with VCTS at all of the terminals. Confidence was high enough in a particular window where storms are more likely at VLD (21-01Z) to include a TEMPO group with some gusty winds and IFR visibility. Similar conditions (gusty winds and IFR visibility) will be possible in any storms today, but confidence was not high enough in timing at any of the other terminals to include additional TEMPO groups. .Marine... Light winds and low seas will prevail through the weekend. After that, it will depend on Erika`s track. No matter the track, at least a slight increase in winds and possibly seas should be expected starting next week. .Fire Weather... An increase in low-level moisture will keep RH levels elevated and allow rain chances to increase from today into the weekend. .Hydrology... With a transition to a wetter pattern beginning today, expect average rainfall amounts on the order of 1-1.5" over the next three days. This will have little impact on area rivers. Next week, the potential for some very heavy rain exists depending on Erika`s track. At this time, models suggest the possibility for 5-7" over a 48 hour period with Erika. Should the track shift west, these amounts could spread into the southeast Big Bend and south-central Georgia. Interests along the Suwannee River are urged to pay close attention to rainfall forecasts over the next few days. && .Preliminary Point Temps/PoPs... Tallahassee 91 75 86 73 90 / 50 40 60 30 50 Panama City 87 77 85 75 88 / 40 50 60 30 30 Dothan 91 73 85 70 89 / 50 40 60 30 30 Albany 91 73 86 71 89 / 50 40 60 40 40 Valdosta 91 74 87 73 90 / 50 40 60 30 50 Cross City 90 75 88 74 90 / 40 40 60 30 50 Apalachicola 89 77 85 76 87 / 50 60 60 40 30 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AL...NONE. GM...NONE. && $$ NEAR TERM...MOORE SHORT TERM...HARRIGAN LONG TERM...HARRIGAN AVIATION...LAMERS MARINE...HARRIGAN FIRE WEATHER...LAMERS HYDROLOGY...HARRIGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
701 AM CDT FRI AUG 28 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 305 AM CDT FRI AUG 28 2015 PCPN CHANCES TODAY AND THEN TEMPERATURES THE NEXT FEW DAYS WILL BE THE MAIN FORECAST CONCERNS. FAIRLY WIDESPREAD AREA OF SHRA AND TSRA WILL CONTINUE TO MOVE EAST THIS MORNING...ASSOCIATED WITH SHORTWAVE TROUGH MOVING THROUGH THE REGION. WATER VAPOR SATELLITE IMAGERY LOOP IN COMBINATION WITH RECENT 500 MB RUC MODEL INITIALIZATIONS SHOWED A FAIRLY STRONG WAVE FOR THIS TIME OF YEAR. 12 HOUR HEIGHT FALLS AT 500 MB WERE UP TO ABOUT 50 METERS. ATMOSPHERE WAS ALSO QUITE MOIST. 700 MB DEWPOINTS OF 4-8 DEGREES C WERE NOTED FROM THE DESERT SW UP INTO WRN KS AND SWRN NE AT 00Z LAST EVENING...AND FORECAST SOUNDINGS SUGGEST PW VALUES ARE AROUND 2 INCHES OR MORE EARLY THIS MORNING. ALTHOUGH THE STRONGEST AREA OF LIFT AND HIGHEST MOISTURE WILL BE SHIFTING EAST OF THE LOCAL AREA...KEPT SOME POPS GOING MUCH OF THE DAY. A WEAKER AREA OF LIFT SHOULD SPREAD SEWD OVER THE REGION AND FORECAST SOUNDINGS STILL SHOW SOME INSTABILITY. WILL KEEP RAIN CHANCES MAINLY AT 20-30 PERCENT AFTER EARLY MORNING ACTIVITY ENDS. RECENT HRRR RUNS AND EVEN THE 00Z NAM SUGGEST PREVIOUS SCENARIO... WITH AT LEAST ISOLD SHRA/TSRA POSSIBLE. LINGERED A SLIGHT CHANCE OF TSRA IN OUR FAR SERN ZONES EARLY THIS EVENING...THEN IT SHOULD BE MAINLY DRY THROUGH SUNDAY. KEPT SOME MENTION OF FOG TONIGHT WITH LIGHT WINDS AND BOTH GFS MOS AND NAM MOS SUGGESTING AT LEAST PATCHY FOG LATE TONIGHT INTO SAT MORNING. DID NOT MENTION FOG SATURDAY NIGHT...BUT SFC RIDGE AXIS WILL BE CLOSE TO THE AREA AND WILL NEED TO MONITOR. RETURN FLOW WITH S/SE SFC WINDS SHOULD THEN STRENGTHEN SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 305 AM CDT FRI AUG 28 2015 MID LEVEL RIDGE EXTENDING FROM NWRN MEXICO UP INTO THE CNTRL PLAINS AND A TROUGH FROM WRN CANADA INTO THE NWRN UNITED STATES WILL BE THE MAIN FEATURES AT THE START OF THIS PERIOD. RIDGE WILL SLIDE SLOWLY SEWD AS THE TROUGH TO THE NORTHWEST DIGS. WEAK RIPPLES MOVING NEWD THROUGH THE REGION COULD BRING SOME TSRA...WITH BEST CHANCES BEING TUE NIGHT AND AGAIN THU NIGHT. TEMPERATURES SHOULD BE AT OR ABOVE NORMAL OVER THE AREA FOR MOST OR ALL OF NEXT WEEK. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 656 AM CDT FRI AUG 28 2015 VARIABLE CONDITIONS EXPECTED DURING THE PERIOD. IFR CIGS LOCATED UNDER UPPER LOW OVER NORTHEAST NEBRASKA AND BEHIND COLD FRONT INTO SOUTH CENTRAL NEBRASKA. LOWER CIGS SHOULD SPREAD EAST BEHIND FRONT THROUGH 18Z WITH CIGS IMPROVING TO MVFR THROUGH 00Z. VFR CONDITIONS THEN DEVELOP AFTER 00Z BUT A PERIOD OF LIFR CIGS AND VSBY POSSIBLE AFTER 09Z AT ALL THREE SITES. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1015 AM EDT FRI AUG 28 2015 .SYNOPSIS... A WEAK FRONT WILL MEANDER OFF THE THE COAST AS HIGH PRESSURE SLOWLY BUILDS INTO THE CAROLINAS OVER THE WEEKEND. ERIKA IS EXPECTED TO APPROACH THE BAHAMAS AND SOUTH FLORIDA LATE IN THE WEEKEND TRACKING THROUGH FLORIDA INTO EARLY NEXT WEEK...AND POSSIBLY REMAINING ON A MORE WESTWARD TRACK CLOSER TO THE GULF COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...HAVE SLIGHTLY CONTINUED THE DOWNWARD TREND IN SKY COVER AND TEMPTED TO DO THE SAME WITH RAIN CHANCES. NEITHER THE 12KM WRF, HRRR, OR RUC BRING ANYTHING MEASUREABLE ONSHORE. WILL WAIT ONE MORE CYCLE TO MONITOR CU DEVELOPMENT AS WELL AS FORMATION OF NE RESULTANT SEABREEZE THAT MAY GRAB AN OFFSHORE SHOWER AND FLING IT ASHORE. BEST CHANCE WOULD BE BALD HEAD ISLAND/SOUTHPORT AREAS. PREVIOUS DISCUSSION FOLLOWS: AS OF 650 AM FRIDAY...HAVE STAYED WITH A DRIER BIAS FOR THIS NEAR TERM FORECAST...AND KEPT THE THREAT FOR LOW CHANCE POPS ACROSS THE COASTAL COUNTIES WITH DIURNALLY DRIVEN CONVECTION THE MAIN EMPHASIS FROM LATE THIS MORNING THRU EARLY THIS EVENING. LATEST WATER VAPOR IMAGERY INDICATES A MUCH DRIER PICTURE COMPARED THIS TIME YESTERDAY MORNING. PROGGED MODEL SOUNDINGS INDICATE DRY AIR BETWEEN 350 MB AND 900 MB BECOMING MORE DOMINANT ACROSS THE FA LATER THIS MORNING THRU TONIGHT AND INTO THE SHORT TERM PERIOD. THE SOMEWHAT STALLED SFC BOUNDARY ORIENTED NE-SW AND PARALLEL TO THE ILM CWA COASTLINE...WILL DRIFT SLIGHTLY FURTHER OFFSHORE THIS PERIOD. THIS HAS ALREADY ALLOWED THE MODEST 1020+ SFC HIGH BROADLY CENTERED OVER THE NE STATES AND MID-ATLANTIC TO RIDGE OR NOSE SOUTH-SOUTHWESTWARD PUSHING DRIER AIR AND LOWER SFC DEWPOINTS TO AND ACROSS THE ILM CWA. ALREADY OBSERVING WIDESPREAD 60S DEWPOINTS ACROSS THE FA...ALL THE WAY TO THE IMMEDIATE COAST. MODELS INDICATE POSSIBLY AROUND 60 THIS AFTN ACROSS THE NORTHERNMOST PORTIONS OF THE FA THIS AFTN WHERE MIXING OF DRIER AIR ALOFT TO THE SFC MAY OCCUR. WITH ALL THIS SAID...THE BEST FORCING/LIFT FOR CONVECTION WILL INITIALLY START JUST ALONG AND OFF THE IMMEDIATE COAST...AND SWITCH FURTHER EAST AND FURTHER OFF THE MAINLAND AS THE BOUNDARY LAYER ASSOCIATED WITH THE STALLED SFC FRONT DRIFTS EASTWARD. HAVE ALSO GONE WITH OVERALL LESS CLOUD COVERAGE...ESPECIALLY TONIGHT WHERE ANY DEBRIS CONVECTIVE CLOUDS WILL EITHER STAY WITHIN THE MEAN FLOW OVER THE ATL WATERS...OR THE DEBRIS CLOUDS THAT PUSH N-NE FROM GA WILL SCOUR OUT A GOOD DEAL PRIOR TO PUSHING ACROSS THE FA. AS FOR TEMPS...LOOKING AT WIDESPREAD 80S FOR MAX TEMPS TODAY...AND WIDESPREAD 60S FOR MINS EXCEPT NEAR 70 ALONG THE IMMEDIATE COAST AND EXTREME SOUTHERN PORTIONS OF THE FA. STAYED WITH A SLIGHTLY COOLER BIAS FOR TONIGHTS MINS USING THE LATEST AVBL MODEL MOS GUIDANCE. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 AM FRIDAY...DRY AIR CONTINUES TO FUNNEL INTO THE AREA IN NORTHERLY FLOW ON BACK END OF LINGERING FRONT/TROUGH/OFF SHORE ON SAT. A WAVE OF LOW PRESSURE DEVELOPS ALONG THE FRONT AND LIFTS OFF TO THE NORTHEAST THROUGH LATE SAT INTO SUN LEAVING WEAK HIGH PRESSURE OVER THE AREA THROUGH SUN NIGHT. THE NORTHERLY FLOW BETWEEN HIGH PRESSURE INLAND AND LOW OFF SHORE ON SAT WILL BEGIN TO VEER AROUND BECOMING MORE ON SHORE THROUGH SUNDAY. ABOVE THE SURFACE...LOW PRESSURE ALOFT OVER THE CENTRAL GULF COAST WILL BEGIN TO MOVE SLOWLY NORTHEAST AND WEAKEN PROVIDING A STEADY SOUTHERLY FLOW OF MOISTURE INTO THE CAROLINAS IN THE LOW TO MID LEVELS SAT NIGHT INTO SUNDAY. THIS IS DEPICTED WELL BY THE MOISTURE PROFILES AND GUIDANCE SHOWING A DEEPENING OF MOISTURE THROUGH THE COLUMN AND AN INCREASE IN CLOUD COVER ON SUNDAY. WITH SUCH DRY AIR IN PLACE IN THE BEGINNING OF PERIOD...EXPECT LIMITED TO NO SHWR ACTIVITY WITH A FEW SHWRS/TSTMS POSSIBLE IN LOCALIZED CONVERGENCE MAINLY ASSOCIATED WITH THE SEA BREEZE OVER THE WEEKEND...WITH MAINLY SOME HIGHER LEVEL CLOUDS AROUND. PCP WATER VALUES DOWN LESS THAN AN INCH OVER INLAND NORTH CAROLINA INCREASE UP TO 1.25 INCHES BY SAT EVE AND UP CLOSE TO 1.5 TO 1.75 INCHES BY SUN AFTN IN A SLOW INCREASE IN MAINLY UPPER LEVEL MOISTURE. THEREFORE EXPECT BETTER CHC OF CONVECTION ON SUNDAY BUT GFS AND ECMWF BOTH SHOWING A WEAKENED ERIKA REACHING OVER SOUTHEAST FLORIDA COAST SUN NIGHT INTO MON WITH EASTERLY FETCH OF MOISTURE REACHING AS FAR NORTH AS SOUTH CAROLINA. OVERALL WESTWARD ADJUSTMENT BY NHC AND GUIDANCE IS EVEN FARTHER WEST. MUCH UNCERTAINTY STILL EXISTS WITH TRACK AND INTENSITY AND THEREFORE WILL NEED TO ADJUST IN FUTURE FORECASTS. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 330 AM FRIDAY...TRENDING DRIER IN OVERALL FORECAST AS LATEST MODEL RUNS SHOW ERIKA OVER FLORIDA ON MONDAY AND THEN TAKING A TURN IN GEORGIA OR POSSIBLY TRACKING ACROSS FLORIDA TOWARD THE GULF COAST. THIS WOULD PRODUCE A GREATER EXTENDED EAST TO NORTHEASTERLY FETCH OVER THE CAROLINAS. FOR NOW KEPT WITH LOWER END CHC POPS AND WITH GREATEST IMPACTS FROM ERIKA STILL EXPECTED MID WEEK...WED INTO THURS. IF ERIKA DOES TAKE A TRACK TO OUR SOUTH MAY END UP WITH MORE IN THE WAY OF SOME GUSTY ON SHORE WINDS AND EXTENDED SWELL ENERGY PRODUCING SOME COASTAL IMPACTS BUT WITH SUCH UNCERTAINTY IN THE MODELS IT IS STILL DIFFICULT TO SAY WITH ANY CERTAINTY. LATEST GFS KEEPS PCP WATER VALUES LOWER THAN 1.5 INCHES THROUGH MOST OF PERIOD OVER NC WITH VALUES REACHING UP CLOSE TO 2 INCHES ON NORTHERN STRETCH OF ERIKA INTO SOUTH CAROLINA. UPPER RIDGE BUILDING OVER THE EASTERN CONUS WILL LEAVE A WEAKNESS BUT TRACK WILL ALSO BE DEPENDENT ON STRENGTH OF ERIKA AS SHE MAKES HER WEST NORTHWEST. THE GFS WANTS TO PULL ERIKA TOWARD THE WEST GETTING PULLED BY THE MID TO UPPER LOW OVER THE WESTERN GULF. OVERALL WENT A BIT MORE OPTIMISTIC FOR OUR AREA WITH A BIT LESS CLOUD COVER AND LESS WIDESPREAD CONVECTION. RAISED MAX TEMPS A BIT...EXPECTING MID TO UPPER 80S MOST PLACES WITH LOWS IN THE LOW TO MID 70S. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...A FRONTAL SYSTEM IS LOCATED JUST OFF THE COAST THIS MORNING WITH ISOLATED SHOWERS ALONG IT. AN AREA OF HIGH PRESSURE IS TO THE N OF THE TERMINALS. AS A RESULT WINDS WILL BE NE-ENE TODAY AT 10-15 KTS AT ALL TERMINALS. DESPITE SOME IFR CIGS SOUTH OF KMYR VFR WILL BE LIKELY TODAY. THERE IS ENOUGH MOISTURE TO HAVE SCT/BKN VFR CIGS THROUGH MIDNIGHT Z AT THE COASTAL TERMINALS. SCT SKIES EXPECTED AT KFLO/KLBT THROUGH THE TAF VALID PERIOD. A LOW PRESSURE AREA WILL DEVELOP ALONG THE FRONT TODAY AND MOVE NE. THERE IS A CHANCE SHOWERS OFFSHORE COULD MOVE TO NEAR THE COASTAL TERMINALS...BUT ALL OF THE LATEST GUIDANCE SUGGEST THE CHANCE IS VERY SMALL. THE BEST CHANCE HOWEVER...WOULD BE KMYR IN THE LATE EVENING OR EARLY MORNING HOURS. WINDS DECREASE THIS EVENING TO 5 KT OR LESS. GUIDANCE IS SUGGESTING FOG DEVELOPMENT OVERNIGHT WITH BEST CHANCE AT KLBT. WILL NOT ADDRESS THIS IN TAFS ATTM. EXTENDED OUTLOOK...PREDOMINATELY VFR WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. BRIEF MORNING FOG/STRATUS IS ALSO EXPECTED EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...MODERATE NE SURGE OF DRY AIR CONTINUES...POSSIBLY STEADY STATE FOR THE NEXT HANDFUL OF HOURS BUT STARTING TO ABATE AROUND MIDDAY. THIS HAS GOTTEN WAVE FACES RATHER STEEP BUT NOT QUITE SCEC-WORTHY IN HEIGHT. THERE ARE NO CHANGES TO THE FORECAST AT THIS TIME. PREVIOUS DISCUSSION FOLLOWS: AS OF 650 AM FRIDAY...THE ENTIRE ILM COASTAL WATERS SHOULD NOW BE ENCOMPASSED WITH A STEADY AND MODEST NE WIND. THE SFC PG FROM THE RIDGING FROM THE 1020+ HIGH FROM THE NORTH WILL BE TIGHT ENOUGH TO PRODUCE A SOLID 15 KT SUSTAINED WIND...EXCEPT INITIALLY 15 TO 20 KT ACROSS THE ILM NC WATERS. LOOKING AT KLTX VWP AND ADJACENT 88D VWPS...WINDS 1K TO 2K FT OFF THE DECK ARE RUNNING NE-ENE AT 15 TO 30 KT. WITH SOME OF THIS MIXING DOWN TO THE OCEAN SFC AS 20+ WIND GUSTS. LOOK FOR A SOLID 15 KT NE WIND SPEED TONIGHT FOR ALL WATERS...WIND DIRECTIONS MAY BRIEFLY VEER TO THE ENE-E NEAR SHORE THIS AFTN/EARLY EVENING DUE TO A RESULTANT WIND BOUNDARY. SIGNIFICANT SEAS WILL RUN A SOLID 4 FT FOR THE ILM NC WATERS FROM CAPE FEAR NORTHWARD THRU THE PERIOD...AND 2 TO 4 FT SOUTH OF THE CAPE. THE 4 TO 6 SECOND PERIOD WIND WAVES WILL DOMINATE THE SIGNIFICANT SEAS...WITH THE UNDERLYING 1 TO 1.5 FOOT ESE GROUND SWELL AT 11-12 SECOND PERIODS REMAINING VISUALLY PRESENT. THE SCATTERED CONVECTION COVERAGE ASSOCIATED WITH THE SOMEWHAT STALLED SFC FRONT...WILL SWITCH TO THE ADJACENT OFFSHORE WATERS. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 AM FRIDAY...NORTHEAST WINDS ON SATURDAY BETWEEN HIGH PRESSURE EXTENDING DOWN OVER THE CAROLINAS AND WEAK LOW PRESSURE DEVELOPING ALONG LINGERING BOUNDARY OFF SHORE. AS THIS LOW PULLS AWAY THROUGH SUNDAY...WINDS MAY COME AROUND TO A MORE EASTERLY ON SHORE DIRECTION AROUND HIGH PRESSURE. EXPECT DEEPEST MOISTURE AND CONVECTION MAINLY EAST OF WATERS ASSOCIATED WITH LINGERING BOUNDARY AND WAVE OF LOW PRESSURE ALONG IT. LATEST FORECAST TRACKS WEAKENED ERIKA OVER FLORIDA BY SUNDAY NIGHT INTO EARLY MONDAY. THIS WOULD MAINLY PRODUCE EASTERLY SWELL ENERGY REACHING INTO THE LOCAL WATERS OVER THE WEEKEND WITH SEAS BASICALLY REMAINING 2 TO 4 FT MOST WATERS. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 330 AM FRIDAY...LATEST FORECAST TRACKS ERIKA OVER FLORIDA AND KEEPS TRENDING WESTWARD WITH TIME GETTING PULLED BY MID TO UPPER LOW IN THE WESTERN GULF. MAY SEE WINDS REMAIN E-NE ONLY RISING UP TO 15 KTS. WITH SO MUCH UNCERTAINTY IN MODEL RUNS...WILL NEED TO KEEP AN EYE ON EVOLUTION OF ERIKA. FOR NOW WILL KEEP MAINLY EAST WINDS LESS THAN 15 KTS AND SEAS BASICALLY 2 TO 4 FT WITH A DIMINISHING LONGER PERIOD SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...MBB/DCH SHORT TERM...RGZ LONG TERM...RGZ AVIATION...MRR .
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1023 AM CDT FRI AUG 28 2015 .UPDATE... ISSUED AT 1019 AM CDT FRI AUG 28 2015 INITIAL BAND OF STORMS DROPPING SOUTHEAST FROM MANITOBA WAS SEVERE WITH LARGE HAIL WINKLER MB TO PEMBINA ND REGION. THESE ARE WEAKENING. QUESTION WILL BE RE-DEVELOPMENT. UPSTREAM WIND FIELD IS QUITE CHAOTIC AND HARD TO TELL WHERE ANY TROUGH IS LOCATED. THAT SAID SOME LOW LEVEL BOUNDARIES PRESENT WITH THE REMAINING SHOWERS DROPPING SOUTH COULD HELP RE-FIRE ACTIVITY THIS AFTN. HRRR AND RAP INDICATE THAT TO OCCUR POSSIBLY JMS-FAR-BJI AREA 21Z-00Z PERIOD. DID ADJUST POPS A BIT TO INCREASE THEM THIS MORNING AND ADJUST A TAD FARTHER WEST AND SOUTH TODAY. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 355 AM CDT FRI AUG 28 2015 VISIBILITY ACROSS NORTHWEST MINNESOTA WILL CONTINUE TO BE VARIABLE IN PATCHY FOG THROUGH THE PREDAWN HOURS... THOUGH ANY FOG SHOULD DISSIPATE SHORTLY AFTER SUNRISE. A STRONG THUNDERSTORM COMPLEX IN SOUTHERN MANITOBA THIS HOUR IS EXPECTED TO DIMINISH IN INTENSITY AS IT BRUSHES THE U.S. BORDER ACROSS NORTHERN CAVALIER AND KITTSON COUNTIES AROUND 12Z. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS THEN POSSIBLE THROUGH THE FORENOON THROUGHOUT THE NORTH BORDER COUNTIES... SPREADING ACROSS FAR NORTHCENTRAL MINNESOTA THROUGH THE EARLY AFTERNOON. A SECOND ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE...STARTING IN EAST CENTRAL ND FROM MID AFTERNOON AND SPREADING EASTWARD ALONG AN EAST-WEST ORIENTED TROF AXIS INTO NORTHWEST MINNESOTA INTO THE EARLY EVENING. EXTENT AND SEVERITY OF THESE STORMS WILL DEPEND ON AFTERNOON HEATING... WITH AFTERNOON TEMPERATURES REACHING INTO THE MID 80S IN SPOTS... THUS SOME STORMS COULD PRODUCE SMALL HAIL AND GUSTY WINDS. LATER TONIGHT AND SATURDAY WILL SEE A RETURN TO LIGHT SOUTHERLY FLOW AND A DRIER...MORE STABLE H5 RIDGE BUILDING IN ALOFT. TEMPERATURES OVERALL WILL BE A BIT WARMER THAN SEASONAL NORMALS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 355 AM CDT FRI AUG 28 2015 SATURDAY NIGHT AND SUUNDAY...EXPECT MORE OF THE SAME. WITH A WARM H5 RIDGE ALOFT AND LIGHT SOUTHERLY WINDS AT THE SURFACE...EXPECT SEASONABLY WARM AND DRY CONDITIONS WITH HIGH TEMPERATURES RANGING FRM THEMID 80S IN CENTRAL MINNESOTA LAKES COUNTRY TO THE LOWER 90S IN THE DEVILS LAKE BASIN. MONDAY-THURSDAY...A VERY SUMMER-LIKE WEATHER PATTERN WILL CONTINUE HEADING INTO THE START OF SEPTEMBER. THE UPPER RIDGE WILL FLATTEN EARLY ON WITH SHORTWAVE ENERGY PASSING NORTH ACROSS CANADA. AN ASSOCIATED WEAK SFC BOUNDARY COULD FIRE A FEW STORMS OFF ON MONDAY...ALTHOUGH THE BEST UPPER SUPPORT WILL BE WELL NORTH OVER CANADA. THIS BOUNDARY SHOULD THEN WASH OUT WITHIN PERSISTENT SOUTHWESTERLY FLOW ALOFT. NOT VERY OPTIMISTIC ABOUT PRECIP CHANCES LATER IN THE PERIOD...ALTHOUGH A STORM COULD NOT BE RULED OUT GIVEN THE SOUTHWEST FLOW PATTERN/RATHER MOIST ENVIRONMENT. WARMER MID- LEVEL TEMPS MAY ACT TO SUPPRESS CONVECTION BY WED INTO THUR AS THE PATTERN AMPLIFIES AHEAD OF AN APPROACHING FRONT. DETAILS OUT AT THIS RANGE ARE STILL QUITE UNCERTAIN THOUGH. AVE HIGHS/LOWS FALL INTO THE MID TO UPPER 70S/LOW 50S DURING EARLY SEPT...BUT HIGHS SHOULD SHOULD REACH THE 80S WITH LOWS MAINLY IN THE 60S THROUGH THUR. WED AND POSSIBLY THUR LOOK TO BE WARMEST AS 850 MB TEMPS RISE TO NEAR 25C. SO SOME HIGHS AT OR ABOVE 90 ARE POSSIBLE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) UPDATED AT 355 PM CDT THU AUG 27 2015 PATCHY FOG STILL POSSIBLE IN NORTHWEST AND WEST CENTAL MINESOTA THROUGH THE EARLY MORNING...LARGELY DISSIPATING WITH SUNRISE. ISOLD SHOWERS AND TSTMS EXPECTED ALONG THE NORTH BORDER COUNTIES THIS FORENOON... WITH SCT TSTMS REDEVELOPING IN THE MID AFTERNOON ACROSS EAST CENTRAL ND AND SPREADING INTO NORTHWEST MN FROM LATE AFTERNONN INTO EARLY EVENING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...GUST LONG TERM...GUST/MAKOWSKI AVIATION...JR/GUST
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
712 AM CDT FRI AUG 28 2015 .UPDATE... LATEST RADAR TRENDS SHOWED THE DEVELOPMENT OF ISOLATED TO SCATTERED LIGHT SHOWERS ACROSS THE ROLLING PLAINS THIS MORNING..AHEAD OF THE COLD FRONT. HAVE ADDED CHANCE POPS ACROSS THE AFOREMENTIONED AREA. && .PREV DISCUSSION... /ISSUED 629 AM CDT FRI AUG 28 2015/ AVIATION... ISOLATED TO SCATTERED -SHRA AND -TSRA HAVE DEVELOPED NORTH OF KCDS...WITH ISOLATED -SHRA DEVELOP CLOSE TO KCDS EARLY THIS MORNING ALONG A COLD FRONT HAVE THEREFORE INSERTED A TEMPO FOR -TSRA FOR A FEW HOURS THIS MORNING. ADDITIONAL DEVELOPMENT IS POSSIBLE AT KLBB AND KPVW LATER THIS AFTERNOON AND EVENING...THOUGH CONFIDENCE IS NOT HIGH ENOUGH TO INSERT A MENTION AT THIS TIME. WILL OF COURSE AMEND AS NECESSARY. OTHERWISE OUTSIDE OF ANY -SHRA/-TSRA...VFR CONDITIONS ARE EXPECTED AS SCT-BKN CLOUD DECKS PASS OVERHEAD. PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 28 2015/ SHORT TERM... UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE- AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z. ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION... SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING PLAINS THROUGHOUT THE SHORT TERM PERIOD. STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE REGION. BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S. LONG TERM... A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS. MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM AND HAVE KEPT MENTION OUT ATTM. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 87 61 89 61 / 20 20 10 0 TULIA 90 62 91 61 / 30 20 10 0 PLAINVIEW 89 63 91 63 / 30 30 10 0 LEVELLAND 93 64 91 64 / 30 30 10 10 LUBBOCK 94 65 92 65 / 30 30 10 0 DENVER CITY 93 63 91 63 / 20 30 10 0 BROWNFIELD 94 65 92 65 / 20 30 10 0 CHILDRESS 96 69 96 68 / 30 20 10 0 SPUR 98 69 94 67 / 20 20 10 10 ASPERMONT 100 72 97 70 / 20 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 29
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
629 AM CDT FRI AUG 28 2015 .AVIATION... ISOLATED TO SCATTERED -SHRA AND -TSRA HAVE DEVELOPED NORTH OF KCDS...WITH ISOLATED -SHRA DEVELOP CLOSE TO KCDS EARLY THIS MORNING ALONG A COLD FRONT HAVE THEREFORE INSERTED A TEMPO FOR -TSRA FOR A FEW HOURS THIS MORNING. ADDITIONAL DEVELOPMENT IS POSSIBLE AT KLBB AND KPVW LATER THIS AFTERNOON AND EVENING...THOUGH CONFIDENCE IS NOT HIGH ENOUGH TO INSERT A MENTION AT THIS TIME. WILL OF COURSE AMEND AS NECESSARY. OTHERWISE OUTSIDE OF ANY -SHRA/-TSRA...VFR CONDITIONS ARE EXPECTED AS SCT-BKN CLOUD DECKS PASS OVERHEAD. && .PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 28 2015/ SHORT TERM... UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE- AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z. ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION... SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING PLAINS THROUGHOUT THE SHORT TERM PERIOD. STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE REGION. BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S. LONG TERM... A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS. MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM AND HAVE KEPT MENTION OUT ATTM. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 87 61 89 61 / 20 20 10 0 TULIA 90 62 91 61 / 30 20 10 0 PLAINVIEW 89 63 91 63 / 30 30 10 0 LEVELLAND 93 64 91 64 / 30 30 10 10 LUBBOCK 94 65 92 65 / 30 30 10 0 DENVER CITY 93 63 91 63 / 20 30 10 0 BROWNFIELD 94 65 92 65 / 20 30 10 0 CHILDRESS 96 69 96 68 / 30 20 10 0 SPUR 98 69 94 67 / 20 20 10 10 ASPERMONT 100 72 97 70 / 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 29
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST FRI AUG 28 2015 .SYNOPSIS...LESS THUNDERSTORM COVERAGE THROUGH TONIGHT BEFORE CHANCES INCREASE THIS WEEKEND. WE WILL KEEP ENOUGH MOISTURE FOR A CHANCE OF THUNDERSTORMS FOR MOST OF NEXT WEEK. HOTTER THAN AVERAGE TEMPERATURES FOR THE NEXT FEW DAYS BEFORE HIGH PRESSURE WEAKENS AND TEMPERATURES SLOWLY FALL TO NEAR AVERAGE BY LATE NEXT WEEK. && .DISCUSSION...IR/VISIBLE SATELLITE IMAGERY DEPICTED SUNNY SKIES ACROSS MUCH OF SE ARIZONA AT THIS TIME. HOWEVER...MOSTLY CLOUDY SKIES WERE ONGOING ACROSS ABOUT THE SOUTHEAST HALF OF COCHISE COUNTY...SE GRAHAM COUNTY AND PORTIONS OF GREENLEE COUNTY. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z RANGED FROM THE UPPER 50S-LOWER 60S. THESE TEMPS WERE ABOUT 2-5 DEGS F HIGHER FROM TUCSON WWD VERSUS 24 HOURS AGO...BUT WERE NEARLY 2-5 DEGS F LOWER ACROSS ERN SECTIONS. 28/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE OF 1.41 INCHES WAS DOWN ABOUT 0.10 INCH VERSUS 24 HOURS AGO. THE ENVIRONMENT WAS MODESTLY UNSTABLE WITH LI/S RANGING FROM MINUS 2-4 DEPENDING UPON LIFTING METHOD. THE 700-300 MB FLOW WAS QUITE LIGHT...WITH MAINLY WLY/NWLY SPEEDS AROUND 5 KTS. 28/12Z UPPER AIR PLOTS CONTINUED TO DEPICT AN EXPANSIVE RIDGE OVER MUCH OF THE WRN CONUS WITH A 595 DM HIGH CENTERED OVER SW NEW MEXICO. LIGHT WLY/NWLY FLOW PREVAILED ACROSS SE ARIZONA ABOVE 700 MB. 28/12Z UNIV OF AZ WRF-NAM AND SEVERAL HRRR SOLUTIONS WERE QUITE SIMILAR WITH DEPICTING THE INITIAL DEVELOPMENT OF SHOWERS/TSTMS BY NOON TO BE ACROSS THE WHITE MOUNTAINS...THE CHIRICAHUA MOUNTAINS IN ERN COCHISE COUNTY AND THE PINALENO MOUNTAINS IN GRAHAM COUNTY. THE BULK OF SHOWERS/TSTMS THEN APPEARS TO BE LIMITED TO MAINLY NEAR THE MOUNTAINS EAST-TO-SOUTHEAST OF TUCSON INTO THIS EVENING. STORM MOTIONS SHOULD BE VERY SLOW AND GENERALLY SEWD. HOWEVER...CANNOT RULE OUT THE POSSIBILITY OF SHOWERS/TSTMS IN VALLEY LOCALES AS FAR WEST AS TUCSON DUE TO DEVELOPMENT FROM CONVECTIVE OUTFLOWS. THUS...THE OFFICIAL FORECAST WILL CONTINUE WITH ISOLATED TO SCATTERED SHOWERS/TSTMS INTO THIS EVENING. THE BULK OF THIS ACTIVITY SHOULD BE EAST OF TUCSON. A SLIGHT CHANCE OF SHOWERS/TSTMS CONTINUES LATE TONIGHT INTO SAT MORNING EAST AND SOUTH OF TUCSON. HIGH TEMPS THIS AFTERNOON WILL AVERAGE ABOUT 3-6 DEGS F ABOVE NORMAL. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL. && .AVIATION...VALID THRU 29/18Z. EXPECT ISOLATED TO SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTH OF KTUS INTO THIS EVENING. A FEW -TSRA/-SHRA MAY OCCUR LATE TONIGHT INTO SATURDAY MORNING. MVFR CONDITIONS AND BRIEF WIND GUSTS OF 35- 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 10-15K FT AGL AND SURFACE WIND WILL MAINLY BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING MAINLY EAST AND SOUTH OF TUCSON. SCATTERED THUNDERSTORMS WILL RETURN TO MUCH OF SOUTHEAST ARIZONA SATURDAY...THEN SCATTERED THUNDERSTORMS WILL PREVAIL MAINLY FROM TUCSON EAST AND SOUTH SUNDAY THROUGH THURSDAY. BRIEF STRONG...GUSTY AND ERRATIC WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS. OTHERWISE...GENERALLY LIGHT TERRAIN DRIVEN WINDS WILL OCCUR INTO NEXT WEEK. && .PREV DISCUSSION /230 AM MST/...SATURDAY AFTERNOON DOESN`T LOOK THAT IMPRESSIVE AS THE HIGH CONTINUES TO SLOWLY WOBBLE EASTWARD...BUT BY LATE SATURDAY AFTERNOON AND EARLY SATURDAY EVENING...OUR MID LEVEL FLOW WILL BE IN THE PROCESS OF PICKING UP A BIT EAST OF TUCSON. THIS WILL FAVOR ORGANIZED EASTERLY THUNDERSTORM OUTFLOW DEVELOPMENT AND SHOULD PUSH SOME STORMS DEEPER INTO OUR CWA (INCLUDING THE TUCSON AREA) EARLY SATURDAY EVENING. HEIGHTS AND THICKNESSES CONTINUE TO SUPPORT HOTTER THAN AVERAGE TEMPERATURES...BUT MUCH DEPENDS ON TIMING AND LOCATIONS OF STORMS. EVEN AS THE RIDGE DEEPENS THROUGH NORTHERN TIER STATES IN OUR REGION SUNDAY AND MONDAY...WE SHOULD MAINTAIN FAVORABLE THUNDERSTORM CONDITIONS THROUGH SOUTHEAST ARIZONA AS OUR WEATHER CONTINUES TO BE DOMINATED BY FEATURES IN SONORA. THERE`S ONLY SO LONG WE CAN MAINTAIN A WESTERLY COMPONENT TO OUR FLOW HOWEVER...SO A DRYING TREND WILL KICK IN SOONER OR LATER IF THE REGION KEEPS THE MEAN TROUGH POSITION THROUGH THE COMING WEEK. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS PREVIOUS DISCUSSION...MEYER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
256 PM MDT FRI AUG 28 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 242 PM MDT FRI AUG 28 2015 TODAY AN UPR RIDGE IS OVR UT AND WRN CO...WITH NW FLOW ALOFT OVR ERN CO AND A WEAK UPR DISTURBANCE MOVING THRU THE NW FLOW OVR ERN CO AND WRN KS. THE NAM AND HRRR SHOW ISOLD TO SCT CONVECTION OVR THE HYR TRRN AND PORTIONS OF THE I-25 CORRIDOR THRU THIS EVENING...BUT THE HRRR ALSO SHOWS THE POTENTIAL FOR A FEW SHOWERS/TSTMS OVR THE SERN PLAINS AS WELL. HAVE ALREADY SEEN A FEW ECHOES DEVELOP OVR BACA AND ERN LAS ANIMAS COUNTIES...SO WL KEEP SOME ISOLD POPS FOR THESE LOCATIONS THIS EVENING...BUT WL KEEP SILENT POPS OVR THE REST OF THE SERN PLAINS. THE DISTURBANCE WILL EXIT THE REGION IN THE EVENING...AND PCPN CHANCES ACRS THE AREA ARE GENERALLY EXPECTED TO END BY MIDNIGHT. ON SATURDAY THE UPR RIDGE MOVES OVR THE AREA. WITH LIMITED MOISTURE...ONLY ISOLD TO SCT PCPN CHANCES ARE EXPECTED OVR THE NR THE HYR TRRN. HIGH TEMPS SATURDAY SHOULD BE AROUND TO SLIGHTLY ABOVE AVERAGE. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 242 PM MDT FRI AUG 28 2015 MODELS IN DECENT AGREEMENT THROUGH THE EXTENDED PERIOD WITH LOW ENSEMBLE SPREADS. THE UPPER PATTERN WILL REMAIN NEARLY STATIONARY WITH RIDGING NORTHWARD OUT OF THE DESERT SOUTHWEST...STRETCHING NORTHEAST INTO THE NORTHERN PLAINS...AND AN UPPER TROUGH SITS ALONG THE WEST COAST. EXPECT PERSISTENT SOUTHWESTERLY FLOW ALONG WITH MONSOONAL MOISTURE TO CONTINUE ACROSS COLORADO THROUGH THE EXTENDED PERIOD. SHOWER AND THUNDERSTORM CHANCES WILL BE HIGHLY DEPENDENT UPON EMBEDDED ENERGY IN THE SOUTHWEST FLOW. CURRENT MODEL ANALYSIS BRINGS NEAR DAILY DISTURBANCES ACROSS THE AREA SATURDAY NIGHT THROUGH TUESDAY. SHOWERS AND THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE MOUNTAINS DURING THE AFTERNOON HOURS...AND SPREAD EAST INTO THE I-25 CORRIDOR DURING THE EVENING BEFORE DISSIPATING OVERNIGHT. THE GFS IS DRIER ON WEDNESDAY AND THURSDAY...AND THE ECMWF IS COMPLETELY DRY THESE DAYS. FOR NOW HAVE LOW POPS IN THE FORECAST FOR THE MOUNTAINS WEDNESDAY AND THURSDAY. A STRONGER DISTURBANCE IS LIKELY TO MOVE NORTH OUT OF THE DESERT SOUTHWEST ON FRIDAY...WITH AN UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY. SHOWERS AND THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...AND FLASH FLOODING WILL CONTINUE TO BE A THREAT...ESPECIALLY ON AREA BURN SCARS. TEMPERATURES WILL REMAIN WARM THROUGH THE EXTENDED PERIOD WITH 80S AND 90S ACROSS MUCH OF THE AREA FOR AFTERNOON HIGHS. MOZLEY && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 242 PM MDT FRI AUG 28 2015 VFR CONDITIONS ARE EXPECTED AT THE TAF SITES TONIGHT THROUGH SATURDAY AFTERNOON. THERE IS A SLIGHT CHANCE FOR ISOLD SHOWERS/TSTMS IN THE VCNTY OF THE TAF SITES THIS EVENING. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...28 LONG TERM...MOZLEY AVIATION...28
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
616 PM EDT FRI AUG 28 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST THROUGH TONIGHT...WITH DRY SURFACE HIGH PRESSURE REMAINING ANCHORED OVER THE WESTERN AND CENTRAL CAROLINAS. INCREASING ATMOSPHERIC MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN AND WESTERN PORTIONS OF OUR REGION LATE SATURDAY...AND INTO REMAINING AREAS SUNDAY. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN FLORIDA SUNDAY NIGHT. REFER TO THE LATEST ADVISORY ON ERIKA ISSUED BY THE NATIONAL HURRICANE CENTER. && .NEAR TERM /THROUGH SATURDAY/... WEAK HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST FOR THE EVENING AND OVERNIGHT HOURS. A WEAK FRONTAL BOUNDARY WILL REMAIN STALLED OFF THE SC COAST. AS A RESULT...A NORTHEASTERLY/EASTERLY FLOW WILL PERSIST OVER THE FORECAST AREA. LATEST RADAR LOOP SHOWING A FEW SHOWERS MAINLY ALONG THE COAST AND ACROSS CNTRL/SRN GA. SLIGHT CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS APPROPRIATE FOR THE EARLY EVENING HOURS. OVERNIGHT...MAINLY DRY CONDITIONS UNDER PARTLY CLOUDY SKIES. OVERNIGHT LOWS RANGING FROM THE MIDDLE 60S NORTH TO AROUND 70 SOUTH. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... MEAN UPPER TROUGH TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED TO OUR E AND SE. SHORTWAVE ENERGY MOVING EAST INTO THE MIDWEST SAT/SUN WILL ALLOW UPPER ENERGY AND MOISTURE TO SLOWLY SHIFT NORTH FROM THE GULF INTO OUR REGION. WITH THE EXCEPTION OF THE NAM...MODELS CONTINUE TO TREND SLOWER WITH MOISTURE RETURN...AND MAINLY RELEGATE IT TO THE S AND W FA SATURDAY...AS SURFACE HIGH PRESSURE AND DRIER AIR REMAINS ENTRENCHED OVER THE WESTERN AND CENTRAL CAROLINAS. THINK SLIGHT CHANCE POPS BY AFTERNOON FOR THE S/W FA LOOK OK SATURDAY. MOISTURE EXPECTED TO CONTINUE TRENDING SLOWLY NORTH SATURDAY NIGHT INTO SUNDAY...WITH INDICATIONS OF WEAK SURFACE HIGH PRESSURE AND DRIER AIR STILL TRYING TO HANG TOUGH OVER THE WESTERN CAROLINAS. MODELS INDICATE A POP GRADIENT OVER OUR FA SUNDAY WITH LOWER POPS NORTH/HIGHER POPS SOUTH. && .LONG TERM /MONDAY THROUGH FRIDAY/... UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST. MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO S FLORIDA BY LATE SUN...AND NORTHWARD INTO N FL/S GA VICINITY BY WED. EVEN WITHOUT THE CYCLONE IN PLAY...IT APPEARS SUFFICIENT ATMOSPHERIC MOISTURE WOULD PROVIDE PREMISE FOR SCATTERED DIURNAL CONVECTION OVER OUR FA ANYWAY. DUE TO UNCERTAINTIES REGARDING POSSIBLE IMPACT OF ERIKA ON OUR REGION...WILL CONTINUE TO MAINTAIN ONGOING FORECAST OF CHANCE POPS...TRENDED A LITTLE HIGHER TO THE SOUTH. GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... LINGERING LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY LEAD TO STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE NAM MOS INDICATED MVFR OR IFR CONDITIONS 06Z TO 15Z. THE GFS MOS PLUS SREF AND HRRR GUIDANCE GENERALLY MAINTAINED VFR CONDITIONS. WE LEANED TOWARD THE MORE OPTIMISTIC GUIDANCE BASED ON UPPER MOISTURE STREAMING INTO THE AREA LIMITING NET RADIATIONAL COOLING AND SURFACE HIGH PRESSURE TO THE NORTH PUSHING DRY AIR TOWARD THE AREA. AN INCREASE IN MOISTURE AND HEATING MAY HELP SUPPORT THUNDERSTORMS SATURDAY AFTERNOON BUT EXPECT SCATTERED COVERAGE WITH THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
607 PM EDT FRI AUG 28 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST THROUGH TONIGHT...WITH DRY SURFACE HIGH PRESSURE REMAINING ANCHORED OVER THE WESTERN AND CENTRAL CAROLINAS. INCREASING ATMOSPHERIC MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN AND WESTERN PORTIONS OF OUR REGION LATE SATURDAY...AND INTO REMAINING AREAS SUNDAY. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN FLORIDA SUNDAY. REFER TO THE LATEST ADVISORY ON ERIKA ISSUED BY THE NATIONAL HURRICANE CENTER. && .NEAR TERM /THROUGH SATURDAY/... WEAK HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST FOR THE REST OF THE AFTERNOON THROUGH TONIGHT WITH A WEAK FRONTAL BOUNDARY STALLED OFF THE SC COAST. AS A RESULT...A NORTHEASTERLY/EASTERLY FLOW WILL PERSIST OVER THE FORECAST AREA. LATEST RADAR LOOP SHOWING A FEW SHOWERS MAINLY ALONG THE COAST AND OVER THE CSRA. LATEST HRRR SHOWING ISOLATED COVERAGE AT BEST THIS AFTERNOON. SLIGHT CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS APPROPRIATE. HIGH TEMPERATURES ARE FORECAST NEAR NORMAL...IN THE UPPER 80S. FOR TONIGHT...MAINLY DRY CONDITIONS UNDER PARTLY CLOUDY SKIES. OVERNIGHT LOWS RANGING FROM THE MIDDLE 60S NORTH TO AROUND 70 SOUTH. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... MEAN UPPER TROUGH TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED TO OUR E AND SE. SHORTWAVE ENERGY MOVING EAST INTO THE MIDWEST SAT/SUN WILL ALLOW UPPER ENERGY AND MOISTURE TO SLOWLY SHIFT NORTH FROM THE GULF INTO OUR REGION. WITH THE EXCEPTION OF THE NAM...MODELS CONTINUE TO TREND SLOWER WITH MOISTURE RETURN...AND MAINLY RELEGATE IT TO THE S AND W FA SATURDAY...AS SURFACE HIGH PRESSURE AND DRIER AIR REMAINS ENTRENCHED OVER THE WESTERN AND CENTRAL CAROLINAS. THINK SLIGHT CHANCE POPS BY AFTERNOON FOR THE S/W FA LOOK OK SATURDAY. MOISTURE EXPECTED TO CONTINUE TRENDING SLOWLY NORTH SATURDAY NIGHT INTO SUNDAY...WITH INDICATIONS OF WEAK SURFACE HIGH PRESSURE AND DRIER AIR STILL TRYING TO HANG TOUGH OVER THE WESTERN CAROLINAS. MODELS INDICATE A POP GRADIENT OVER OUR FA SUNDAY WITH LOWER POPS NORTH/HIGHER POPS SOUTH. && .LONG TERM /MONDAY THROUGH FRIDAY/... UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST. MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO S FLORIDA BY LATE SUN...AND NORTHWARD INTO N FL/S GA VICINITY BY WED. EVEN WITHOUT THE CYCLONE IN PLAY...IT APPEARS SUFFICIENT ATMOSPHERIC MOISTURE WOULD PROVIDE PREMISE FOR SCATTERED DIURNAL CONVECTION OVER OUR FA ANYWAY. DUE TO UNCERTAINTIES REGARDING POSSIBLE IMPACT OF ERIKA ON OUR REGION...WILL CONTINUE TO MAINTAIN ONGOING FORECAST OF CHANCE POPS...TRENDED A LITTLE HIGHER TO THE SOUTH. GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... LINGERING LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY LEAD TO STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE NAM MOS INDICATED MVFR OR IFR CONDITIONS 06Z TO 15Z. THE GFS MOS PLUS SREF AND HRRR GUIDANCE GENERALLY MAINTAINED VFR CONDITIONS. WE LEANED TOWARD THE MORE OPTIMISTIC GUIDANCE BASED ON UPPER MOISTURE STREAMING INTO THE AREA LIMITING NET RADIATIONAL COOLING AND SURFACE HIGH PRESSURE TO THE NORTH PUSHING DRY AIR TOWARD THE AREA. AN INCREASE IN MOISTURE AND HEATING MAY HELP SUPPORT THUNDERSTORMS SATURDAY AFTERNOON BUT EXPECT SCATTERED COVERAGE WITH THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
500 PM CDT FRI AUG 28 2015 .SHORT TERM... TONIGHT AND SATURDAY... 250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND RAINFALL AMOUNTS. LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS. AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING... PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES FROM CURRENT POPS IN THE 40-50 PERCENT RANGE. TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER. CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE A BIT COOLER. CMS && .LONG TERM... 307 PM CDT SATURDAY NIGHT THROUGH FRIDAY... THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT WITH PREVIOUS RUNS. THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST MAY CAUSE SOME DELAY IN THE MOISTURE RETURN. THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD COVER. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * CHANCE OF SHRA/SLIGHT CHANCE OF TS TONIGHT INTO SAT MORNING. SLIGHTLY BETTER CHANCE OF THUNDER SATURDAY AFTERNOON. KJB/BMD //DISCUSSION...UPDATED 18Z... AN ATMOSPHERIC DISTURBANCE...CURRENTLY DRIVING AN AREA OF SHOWERS AND EMBEDDED STORMS OVER IOWA...WILL GRADUALLY SHIFT EASTWARD TONIGHT. HOWEVER...IT APPEARS THE MAIN FOCUS FOR SHOWERS AND ANY STORMS MAY LARGELY REMAIN NORTH OF THE EASTERN TERMINALS...ACROSS FAR NORTHERN ILLINOIS AND INTO WISCONSIN. BETTER CHANCES OF MORE SUBSTANTIAL SHOWERS LOOKS TO ENTER THE PICTURE AFTER DAYBREAK SATURDAY...AND CONTINUING AT TIMES INTO THE AFTERNOON. IT APPEARS THE THUNDER THREAT WILL BE LOW WITH MUCH OF THIS ACTIVITY. HOWEVER...THERE WILL BE A SLIGHT BETTER CHANCE OF THUNDER SUNDAY AFTERNOON AS A FRONTAL ZONE SAGS SOUTHEASTWARD OVER THE AREA. GIVEN THIS...I HAVE OPTED TO ADD A PROB30 FOR A PERIOD OF THUNDER LATER SATURDAY AFTERNOON AT THE END OF THE 30 HOUR ORD TAF. KJB //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM WITH PRECIP CHANCES/TIMING...ESPECIALLY SATURDAY MORNING/EARLY AFTERNOON. * LOW WITH THREAT OF THUNDER DURING THE PERIOD. * HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS. KJB/BMD //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...SLIGHT CHANCE OF TSRA...OTHERWISE VFR. SUNDAY...VFR. NORTHEAST WINDS. MONDAY THROUGH THURSDAY...VFR. SOUTHERLY WINDS...POSSIBLE AFTERNOON WIND SHIFTS TO EASTERLY WITH LAKE BREEZES EACH AFTERNOON. IZZI && .MARINE... 310 PM CDT HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
310 PM CDT FRI AUG 28 2015 .SHORT TERM... TONIGHT AND SATURDAY... 250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND RAINFALL AMOUNTS. LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS. AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING... PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES FROM CURRENT POPS IN THE 40-50 PERCENT RANGE. TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER. CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE A BIT COOLER. CMS && .LONG TERM... 307 PM CDT SATURDAY NIGHT THROUGH FRIDAY... THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT WITH PREVIOUS RUNS. THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST MAY CAUSE SOME DELAY IN THE MOISTURE RETURN. THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD COVER. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WIND SHIFT TO EAST-SOUTHEASTERLY LIKELY EARLY THIS EVENING. * CHANCE OF SHRA/SLIGHT CHANCE OF TS TONIGHT INTO SAT MORNING. SLIGHTLY BETTER CHANCE OF THUNDER SATURDAY AFTERNOON. KJB //DISCUSSION...UPDATED 18Z... AN ATMOSPHERIC DISTURBANCE...CURRENTLY DRIVING AN AREA OF SHOWERS AND EMBEDDED STORMS OVER IOWA...WILL GRADUALLY SHIFT EASTWARD TONIGHT. HOWEVER...IT APPEARS THE MAIN FOCUS FOR SHOWERS AND ANY STORMS MAY LARGELY REMAIN NORTH OF THE EASTERN TERMINALS...ACROSS FAR NORTHERN ILLINOIS AND INTO WISCONSIN. BETTER CHANCES OF MORE SUBSTANTIAL SHOWERS LOOKS TO ENTER THE PICTURE AFTER DAYBREAK SATURDAY...AND CONTINUING AT TIMES INTO THE AFTERNOON. IT APPEARS THE THUNDER THREAT WILL BE LOW WITH MUCH OF THIS ACTIVITY. HOWEVER...THERE WILL BE A SLIGHT BETTER CHANCE OF THUNDER SUNDAY AFTERNOON AS A FRONTAL ZONE SAGS SOUTHEASTWARD OVER THE AREA. GIVEN THIS...I HAVE OPTED TO ADD A PROB30 FOR A PERIOD OF THUNDER LATER SATURDAY AFTERNOON AT THE END OF THE 30 HOUR ORD TAF. KJB //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH WITH WIND SHIFT TO SOUTHEAST THIS EVENING...LOW WITH PRECISE SPEEDS AND TIMING. * MEDIUM WITH PRECIP CHANCES/TIMING...ESPECIALLY SATURDAY MORNING/EARLY AFTERNOON. * LOW WITH THREAT OF THUNDER DURING THE PERIOD. * HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS. KJB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...SLIGHT CHANCE OF TSRA...OTHERWISE VFR. SUNDAY...VFR. NORTHEAST WINDS. MONDAY THROUGH THURSDAY...VFR. SOUTHERLY WINDS...POSSIBLE AFTERNOON WIND SHIFTS TO EASTERLY WITH LAKE BREEZES EACH AFTERNOON. IZZI && .MARINE... 310 PM CDT HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS. 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/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
250 PM CDT FRI AUG 28 2015 .SHORT TERM... TONIGHT AND SATURDAY... 250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND RAINFALL AMOUNTS. LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS. AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING... PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES FROM CURRENT POPS IN THE 40-50 PERCENT RANGE. TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER. CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE A BIT COOLER. CMS && .LONG TERM... 344 AM CDT SUNDAY THROUGH THURSDAY... END OF THE WEEKEND INTO THE START OF NEXT WEEK WILL SEE THIS MID/UPPER TROUGH SLOWLY EXITING TO THE EAST...WITH CLOUDS AND PRECIP CHANCES LIKEWISE EXITING DURING THE DAY SUNDAY. GUIDANCE VARIES TO THE EVOLUTION OF THIS EXITING SYSTEM BUT LIKELY SCENARIO FOR OUR AREA WILL BE FOR UPPER LEVEL RIDGING WITH WEAKER FLOW ALOFT. CONDITIONS WILL LIKELY BE ON THE DRY SIDE THROUGH EARLY NEXT WEEK...OUTSIDE OF SOME POSSIBLE AFTERNOON THUNDERSTORMS ON TUESDAY DUE TO INCREASING MOISTURE/INSTABILITY...WHILE A WARMING TREND CONTINUES. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WIND SHIFT TO EAST-SOUTHEASTERLY LIKELY EARLY THIS EVENING. * CHANCE OF SHRA/SLIGHT CHANCE OF TS TONIGHT INTO SAT MORNING. SLIGHTLY BETTER CHANCE OF THUNDER SATURDAY AFTERNOON. KJB //DISCUSSION...UPDATED 18Z... AN ATMOSPHERIC DISTURBANCE...CURRENTLY DRIVING AN AREA OF SHOWERS AND EMBEDDED STORMS OVER IOWA...WILL GRADUALLY SHIFT EASTWARD TONIGHT. HOWEVER...IT APPEARS THE MAIN FOCUS FOR SHOWERS AND ANY STORMS MAY LARGELY REMAIN NORTH OF THE EASTERN TERMINALS...ACROSS FAR NORTHERN ILLINOIS AND INTO WISCONSIN. BETTER CHANCES OF MORE SUBSTANTIAL SHOWERS LOOKS TO ENTER THE PICTURE AFTER DAYBREAK SATURDAY...AND CONTINUING AT TIMES INTO THE AFTERNOON. IT APPEARS THE THUNDER THREAT WILL BE LOW WITH MUCH OF THIS ACTIVITY. HOWEVER...THERE WILL BE A SLIGHT BETTER CHANCE OF THUNDER SUNDAY AFTERNOON AS A FRONTAL ZONE SAGS SOUTHEASTWARD OVER THE AREA. GIVEN THIS...I HAVE OPTED TO ADD A PROB30 FOR A PERIOD OF THUNDER LATER SATURDAY AFTERNOON AT THE END OF THE 30 HOUR ORD TAF. KJB //ORD AND MDW CONFIDENCE...UPDATED 20Z... * HIGH WITH WIND SHIFT TO SOUTHEAST THIS EVENING...LOW WITH PRECISE SPEEDS AND TIMING. * MEDIUM WITH PRECIP CHANCES/TIMING...ESPECIALLY SATURDAY MORNING/EARLY AFTERNOON. * LOW WITH THREAT OF THUNDER DURING THE PERIOD. * HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS. KJB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...SLIGHT CHANCE OF TSRA...OTHERWISE VFR. SUNDAY...VFR. NORTHEAST WINDS. MONDAY THROUGH THURSDAY...VFR. SOUTHERLY WINDS...POSSIBLE AFTERNOON WIND SHIFTS TO EASTERLY WITH LAKE BREEZES EACH AFTERNOON. IZZI && .MARINE... 157 AM CDT FAIRLY TYPICAL SUMMER PATTERN LIKELY TO PERSIST THROUGH THE UPCOMING WEEK WITH GENERALLY NO SIGNIFICANT WINDS/WAVES ANTICIPATED. WEAK SURFACE LOW OVER THE CORN BELT WILL TRACK SLOWLY EAST INTO NORTHERN ILLINOIS/SOUTHERN WISCONSIN THROUGH SATURDAY BEFORE DISSIPATING. THE MAIN RESULT WILL BE A BACKING OF WINDS TO EASTERLY OVER SOUTHERN PORTIONS OF THE LAKE LATER TODAY INTO THIS EVENING BEFORE VEERING SOUTHERLY AGAIN LATE TONIGHT AND FRESHENING UP JUST A BIT...BUT LIKELY LESS THAN 20KT. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
243 PM CDT FRI AUG 28 2015 .SHORT TERM...(TONIGHT) ISSUED AT 243 PM CDT FRI AUG 28 2015 AFTERNOON SURFACE MAP SHOWING LOW PRESSURE CENTERED NEAR OMAHA, WITH A WARM FRONT EXTENDING NORTHEAST ACROSS IOWA AND A COLD FRONT INTO CENTRAL KANSAS. MAIN ACTIVITY OF SHOWERS AND THUNDERSTORMS HAS BEEN CLOSER TO THE WARM FRONT AND TRACKING NORTH OF OUR FORECAST AREA. A GENERAL EASTWARD PROGRESSION OF THE BOUNDARIES IS EXPECTED OVER THE NEXT SEVERAL HOURS, WITH THE COLD FRONT APPROACHING THE ILLINOIS/IOWA BORDER TOWARD 3-4 AM. FORECAST SOUNDINGS ARE RATHER DRY BELOW 12,000 FEET FROM ABOUT PEORIA EAST AND SOUTH, AND AM STARTING TO GET CONCERNED THAT THERE WILL BE LITTLE MORE THAN ISOLATED SHOWERS BETWEEN I-55 AND THE ILLINOIS RIVER TONIGHT. HOWEVER, THE HRRR AND ARW MODELS ARE A BIT MORE AGGRESSIVE WITH SHOWERS MOVING INTO THIS AREA AFTER 3 AM, SO WILL MAINTAIN CHANCE POP`S ACROSS THE ILLINOIS RIVER VALLEY MAINLY FROM LATE EVENING THROUGH OVERNIGHT. INSTABILITY IS A LITTLE MORE SPARSE THOUGH, WITH THE CURRENT THUNDER ACTIVITY MAINLY NEAR THE UPPER LEVEL DISTURBANCE TRACKING ACROSS CENTRAL IOWA, AND HAVE TRIMMED BACK THE THUNDER POTENTIAL TO MAINLY WEST OF THE RIVER. OTHERWISE, HAVE MAINLY GONE DRY EAST OF I-55. MILDER CONDITIONS EXPECTED OVERNIGHT WITH CLOUD COVER MUCH MORE EXTENSIVE AND A SOUTHERLY FLOW, WITH MOST AREAS DIPPING INTO THE MID 60S. && .LONG TERM...(SATURDAY THROUGH FRIDAY) ISSUED AT 243 PM CDT FRI AUG 28 2015 LOW PRESSURE AREA AND ASSOCIATED FRONT WEST OF THE AREA WILL CONTINUE TO SLOWLY MOVE EAST AND INTO THE CWA DURING THE WEEKEND. HOWEVER...VERY LITTLE SUPPORT FOR THIS SYSTEM AS IT MOVES EAST SO ALL MODELS HAVE THIS SYSTEM WEAKENING AS IT MOVES INTO THE AREA. THEREFORE...WILL ONLY HAVE CHANCE POPS FOR SAT MORNING WEST OF I-55 AND THEN MOVE POPS EAST DURING THE AFTERNOON BUT REMAINING MAINLY NORTH OF I-70 AS FRONT CONTINUES TO WEAKEN AND BECOME SOMEWHAT PARALLEL TO THE FLOW AND VERY LACKING ON CONVERGENCE/SUPPORT. CHANCE POPS FOR SAT NIGHT WILL CONTINUE AS THE UPPER LEVEL WAVE SHIFTS EAST ACROSS THE AREA. PCPN WILL BE MAINLY SHOWERS AND ISOLATED THUNDERSTORMS...DUE TO LACK OF FORCING AND INSTABILITY. BY SUNDAY...THE WAVE SHOULD BE VERY WEAK AND EAST OF THE CWA...SO WILL ONLY HAVE SLIGHT CHANCE POPS. FOR REMAINDER OF THE WEEKEND AND INTO THE BEGINNING OF NEXT WEEK...DRY CONDITIONS CAN BE EXPECTED AS HIGH PRESSURE BEGINS TO BUILD IN THE WEST AND PUSH INTO THE NORTHERN PART OF THE AREA. BEGINNING TUE AND THROUGH MOST OF THE WEEK...A COUPLE OF MODELS BRING REMNANTS OF TS ERIKA INTO THE AREA. HOWEVER...THIS IS DEPENDENT ON WHERE THE TS GOES. AND IT IS FAR ENOUGH AWAY IN TIME THAT WILL JUST KEEP CLOSE TO WHAT THE CRINT HAS...AND THAT IS JUST SLIGHT CHANCE POPS IN SOME AREAS FOR WED THROUGH THUR. SLIGHT CHANCE POPS WILL BE IN THE GRIDS BUT NOT MENTIONED IN THE WORDED FORECAST. TEMPS THROUGH THE WEEKEND WILL BE TEMPERED DUE TO CLOUD COVER AND SCATTERED PCPN...BUT STILL EXPECTING THEM TO RISE INTO THE 80S FOR THE WEEKEND. BY NEXT WEEK...WITH UPPER LEVEL RIDGING BUILDING INTO THE AREA AND DEWPOINTS BEING DRIER...EXPECTING TEMPS TO RISE INTO THE UPPER 80S TO AROUND 90 FOR THE ENTIRE WEEK. THIS WILL BE MUCH ABOVE NORMAL FOR THE BEGINNING OF SEPT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1227 PM CDT FRI AUG 28 2015 MAIN QUESTION FOR THIS TAF SET WILL BE THE ARRIVAL OF ANY SHOWERS/STORMS. FORECAST SOUNDINGS ARE SHOWING QUITE A BIT OF DRY AIR BELOW 10KFT MOST OF THE PERIOD...FINALLY MOISTENING UP AROUND KPIA TOWARD SUNRISE. HOWEVER...INSTABILITY REMAINS RATHER LIMITED...SO WILL KEEP MENTION OF THE VCSH THERE WITHOUT ANY MENTION OF THUNDER. THE REMAINDER OF CENTRAL ILLINOIS WILL MAINLY SEE A GRADUAL LOWERING OF HIGH CLOUDS THROUGH THE NEXT 24 HOURS...WITH SOUTH-SOUTHEAST WINDS TRENDING MORE SOUTH-SOUTHWEST BY MID MORNING SATURDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GEELHART LONG TERM...AUTEN AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS DES MOINES IA
358 PM CDT FRI AUG 28 2015 .SHORT TERM /TONIGHT/... ISSUED AT 358 PM CDT FRI AUG 28 2015 HEAVY RAIN WILL PERSIST ACROSS THE NORTHEAST THROUGH THE EVENING. LATEST HRRR RUN KEEPS CONVECTION GOING IN THE FAR EAST THROUGH 04-05Z TIME FRAME AND LEANED TOWARD THIS SOLUTION FOR POPS/WX. THE WARM RAIN PROCESSES CURRENTLY AFFECTING THE FLASH FLOOD WARNED AREAS ARE PRODUCING 2-4 INCH PER HOUR RAINFALL RATES. STRONG DEEP MOISTURE CONVERGENCE OVER THE WATERLOO AREA WITH ROUGHLY 1.5-2 INCH PRECIPITABLE WATER AND WARM CLOUD DEPTHS TO AROUND 4000 METERS IS ENOUGH TO CONTINUE THE HEAVY RAIN THREAT BEFORE SURFACE LOW IN WESTERN IOWA PUSHES FURTHER EAST LATER THIS EVENING. POTENTIAL FOR HEAVY RAIN TO CONTINUE IN THE EAST TO NORTHEAST SECTIONS OF THE FORECAST AREA THROUGH 03Z TONIGHT...TO COINCIDE WITH THE LATEST HRRR THINKING. OTHER CONCERN IS FOG OVERNIGHT WITH PLENTY OF MOISTURE AND VERY LITTLE FLOW AT THE SURFACE A WEAK SURFACE RIDGE BUILDS INTO WESTERN IOWA. HAVE MENTIONED PATCHY FOG PAST 09Z WEST OF I-35. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 358 PM CDT FRI AUG 28 2015 THE WEATHER WILL GENERALLY BE QUIET IN THE LONGER TERM WITH UPPER RIDGING BUILDING INTO THE CENTRAL UNITED STATES. THICKNESSES WILL INCREASE WITH TEMPERATURES CORRESPONDINGLY RESPONDING WITH HIGHS CLIMBING ABOVE NORMAL...LIKELY TOWARD 90 BY EARLY NEXT WEEK...ESPECIALLY IN THE SOUTH AND WEST. BOTH GFS AND EURO INDICATED A WEAK SYSTEM PULLING NORTHEAST ON TUESDAY INTO THE PLAINS WHICH MAY BRING THE THREAT OF ISOLATED THUNDER INTO THE NORTHWEST PORTIONS OF IOWA BY LATER IN THE DAY INTO TUESDAY NIGHT. OTHERWISE...THE RIDGE WILL REMAIN IN PLACE INTO LATE IN THE WEEK WITH THE VERY WARM TEMPERATURES AND LITTLE THREAT OF PRECIPITATION. && .AVIATION...28/18Z ISSUED AT 105 PM CDT FRI AUG 28 2015 IFR TO MVFR STRATUS WILL PERSIST THROUGH THE AFTERNOON AND INTO THE OVERNIGHT HOURS. MCW/ALO HAVE THE BEST SHOT OF IFR VIS WRT TO HEAVY RAIN THIS AFTERNOON. OTHERWISE...EXPECTING FOG/STRATUS TO CONTINUE OVERNIGHT INTO SATURDAY MORNING AND HAVE MENTION OF IFR CONDITIONS PAST 06Z SATURDAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...PODRAZIK LONG TERM...COGIL AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT FRI AUG 28 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 411 PM EDT FRI AUG 28 2015 WV IMAGERY AND RAP ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL FLOW ALONG THE US/CANADIAN BORDER. A SHORTWAVE TROUGH FROM NW ONTARIO INTO NRN MN SUPPORTED SCT SHRA/TSRA OVER THE MN ARROWHEAD INTO NRN ONTARIO WEST OF THUNDER BAY. TO THE SOUTH...ANOTHER SHRTWV OVER IA BRINGING SHOWERS FROM NE IA THROUGH SW WI WAS SLOWLY LIFTING TO THE ENE. THE LEADING EDGE OF THE PCPN TO NEAR AUW. OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES PREVAILED ACROSS UPPER MI WITH TEMPS IN THE MID 70S. TONIGHT...MOST OF THE CWA WILL REMAIN BETWEEN THE INFLUENCE OF THE NRN AND SRN STREAM SHORTWAVES. RADAR TRENDS AND SHORT RANGE MODELS SUGGEST THAT THE RAIN OVER WI TO AFFECT MAINLY THE SRN TIER ALONG AND SOUTH OF US-2 FROM IMT EASTWARD. SHRA/TSRA WITH THE NRN STREAM SHRTWV MAY BRUSH MAINLY THE KEWEENAW BY LATE THIS EVENING AND POSSIBLY INTO THE NRN PORTION OF UPPER MI. FCST MUCAPE VALUES INTO THE 500-1000 J/KG RANGE OVER THE NORTH COULD ALSO SUPPORT ISOLD TSRA. SATURDAY...SOME SHOWERS MAY LINGER OVER THE SE PORTION OF THE CWA ASSOCIATED WITH REMNANTS OF THE WI SHRTWV OR POSSIBLY AIDED BY A TRAILING SHRTWV DIVING INTO NRN WI. HOWEVER...EXPECT THE PCPN TO SLIDE OFF TO THE EAST BY AFTERNOON. WITH SOME CLEARING INTO THE WEST HALF BY AFTERNOON...TEMPS WILL REBOUND INTO THE MID AND UPPER 70. GREATER CLOUD COVER OVER THE EAST AND WITH SRLY FLOW OFF OF LAKE MI...TEMPS WILL REMAIN IN UPPER 60S AND LOWER 70S. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 344 PM EDT FRI AUG 28 2015 COULD SEE A FEW SHOWERS IN THE FIRST 6 HOURS OF THE FORECAST SAT NIGHT...BUT THINK VAST MAJORITY OF PRECIP ASSOCIATED WITH A SHORTWAVE WILL BE OUT OF THE AREA. OTHERWISE...PRECIP CHANCES ARE LOW IN THE LONG TERM AS A MID-UPPER RIDGE MOVES IN AND SITS OVER THE CENTRAL TO ERN CONUS. COULD SEE SOME PRECIP MID-LATE NEXT WEEK AS SHORTWAVES TRY TO TOP THE RIDGE...BUT PREDICTABILITY IS TOO LOW TO JUSTIFY ANYTHING ABOVE SLIGHT CHANCE POPS. TEMPS WILL BE ON THE INCREASE AND WILL ALREADY BE ABOVE NORMAL SUN. HIGHS SUN WILL BE IN THE MID 70S TO LOW 80S AS 850MB TEMPS START OUT IN THE MID TEENS C. 850MB TEMPS THROUGH THE REST OF THE WEEK WILL BE AROUND 20C...RESULTING IN HIGH TEMPS 10 OR MORE DEGREES ABOVE NORMAL. COULD SEE SOME PATCHY FOG AROUND SAT NIGHT INTO EARLY SUN MORNING AND AGAIN SUN NIGHT INTO MON MORNING AS HIGH PRESSURE/SUBSIDENCE MOVES IN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 141 PM EDT FRI AUG 28 2015 MVFR CIGS AT CMX ARE EXPECTED TO GIVE WAY TO VFR CONDITIONS BY LATE THIS AFTERNOON. THERE IS ALSO SLIGHT CHANCE FOR SHOWERS AT CMX...BUT PROB IS TOO LOW TO INCLUDE IN THE TAF. OTHERWISE...VFR CONDITIONS WILL CONTINUE THROUGH THIS FCST PERIOD AT KIWD/KSAW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 411 PM EDT FRI AUG 28 2015 EXPECT A PERIOD OF MODERATE SW WINDS LATE TONIGHT INTO EARLY GUSTING TO 15-20 KNOTS. OTHERWISE...A GENERALLY WEAK PRES GRADIENT WILL DOMINATE THE UPPER LAKES INTO EARLY NEXT WEEK. ON MOST DAYS...WINDS WILL BE UNDER 15KT. LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE WEEKEND WITH HIGH PRES RIDGE MORE FIRMLY IN CONTROL. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...TITUS AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
523 PM CDT FRI AUG 28 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 315 PM CDT FRI AUG 28 2015 WATER VAPOR IMAGERY SHOWS THAT A SHORTWAVE TROUGH IS MOVING SLOWLY EAST ACROSS MISSOURI AT THIS HOUR. LATEST RUNS OF THE RAP SUGGEST THAT IT WILL TAKE ALL EVENING FOR THIS FIRST SHORTWAVE TO REACH HALFWAY ACROSS THE CWA WHILE A SECOND SHORTWAVE WILL ENTER WESTERN MISSOURI BEHIND IT LATER TONIGHT. LOW LEVEL MOISTURE CONVERGENCE WILL INCREASE ACROSS EASTERN MISSOURI BY LATER THIS EVENING AS LOW LEVEL JET VEERS AND INCREASES IN SPEED SLIGHTLY. THIS SHOULD CAUSE AN INCREASE IN COVERAGE IN SCATTERED SHOWERS AND THUNDERSTORMS BY LATE EVENING AND OVERNIGHT OVER THE REGION BECAUSE OF THE FORCING FROM THE SHORTWAVES AND THE MOISTURE CONVERGENCE. THE 1KM REFLECTIVITY FROM THE CAMS DEPICTS THIS PRETTY WELL. MOS LOWS TONIGHT LOOK REASONABLE GIVEN THE INCREASING DEWPOINTS AHEAD OF THE COLD FRONT CURRENTLY OVER THE CENTRAL PLAINS. BRITT .LONG TERM: (SATURDAY THROUGH NEXT FRIDAY) ISSUED AT 316 PM CDT FRI AUG 28 2015 AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ON SATURDAY AND SATURDAY EVENING AS AN UPPER LEVEL TROUGH MOVES SLOWLY SOUTHEASTWARD THROUGH OUR AREA. IT NOW APPEARS THAT THE COLD FRONT WILL ONLY MAKE IT INTO NORTHEAST MO AND WEST CENTRAL IL BEFORE GRADUALLY DISSIPATING. ONLY SLIGHT COOLING IS EXPECTED ACROSS NORTHEAST MO AND WEST CENTRAL IL SATURDAY AND SATURDAY NIGHT WITH THE REST OF THE AREA SLIGHTLY WARMER AND MORE HUMID DESPITE THE CLOUD COVER ON SATURDAY WITH MAINLY A WEAK SOUTHERLY FLOW. ALTHOUGH THE CHANCE OF PRECIPITATION WILL LESSEN BY LATE SATURDAY NIGHT AND SUNDAY...THERE MAY STILL BE AT LEAST ISOLATED SHOWERS/STORMS ACROSS MAINLY SOUTHEAST MO AND SOUTHWEST IL AS THE WEAKENING UPPER LEVEL TROUGH...SHEAR AXIS MOVES ONLY SLOWLY SOUTHEASTWARD. A WAMER PERIOD OF WEATHER IS FORECAST FOR THE NEXT WORK WEEK DUE TO PERSISTENT SOUTHERLY SURFACE/LOW LEVEL FLOW WITH THE SURFACE/850 MB RIDGE EAST/SOUTHEAST OF OUR AREA...AND AT LEAST UPPER LEVEL RIDGING ACROSS NORTHWEST MO. WILL KEEP THE REMAINDER OF THE FORECAST DRY FOR NOW...ALTHOUGH COULD NOT RULE OUT A FEW SHOWERS/STORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS AS THE MODELS CONTINUE TO DEPICT SOME WEAK MID-UPPER LEVEL TROUGHING...SHEAR AXIS ACROSS MAINLY SOUTHEAST MO AND SOUTHWEST IL. GKS && .AVIATION: (FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 519 PM CDT FRI AUG 28 2015 SLOW MOVING TROF OF LOW PRESSURE AND SEVERAL UPPER AIR DISTURBANCES WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION TONIGHT THROUGH SATURDAY NIGHT. EXPECT VFR CONDITIONS OUTSIDE OF ANY HEAVIER SHOWERS THAT COULD TEMPORARILY REDUCE THE VISIBILITY AND CEILING AT A TERMINAL. LIGHT SOUTHEAST/SOUTH WIND EXPECTED TO CONTINUE THROUGH THE PERIOD. SPECIFICS FOR KSTL: SCATTERED SHOWERS SHOULD ARRIVE NEAR THE TERMINAL COMPLEX AROUND 12Z WITH THE THREAT OF SCATTERED THUNDERSTORMS DEVELOPING DURING THE HEAT OF THE DAY...OR AFTERNOON. CONFIDENCE IN COVERAGE OF RAIN IS NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST OUTSIDE OF VICINITY AT THIS TIME. LIGHT SOUTHEAST TO SOUTH WIND EXPECTED TO CONTINUE THROUGH THE PERIOD. CVKING && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
409 PM CDT FRI AUG 28 2015 .DISCUSSION... Issued at 409 PM CDT FRI AUG 28 2015 Tonight... Positive tilted shortwave trough as noted in satellite imagery from IA through KS will slide east tonight. Scattered convection will form along an associated cold front within a moderately unstable airmass....at least it will be into the early evening hours. A narrow band of convection has finally formed over east central KS where MLCAPES between 1500-2000J/kg are noted. Further northeast VFR ceilings within the warm sector have pretty much capped intense convection as radar shows sputtering area of low topped showers. The east central KS activity may be the only region which develops deep convection, albeit the non-severe variety. Will hit PoPs highest over northern and west central counties until a few hours after sunset. Thereafter expect a fairly quick drop off in intensity and coverage as instability hits the skids. Believe the trend of the HRRR and 12z NAM looks reasonable. QPF will also be muted. Could see isolated showers form after the passage of the frontal convection and last into the pre-dawn hours. Saturday - Sunday... The above shortwave is expected to flounder over the Mid MO Valley over the weekend. The h7 shortwave trough will be slow to exit the CWA resulting in a general region of uvv over the eastern 1/2 of the CWA. Thinking there will be sufficient breaks in the overcast such that isolated instability showers/storms will be possible Saturday afternoon over parts of northeast and central MO. Current temperature forecast may be a bit too optimistic should the afternoon clouds fail to break up. Sunday looks dry with a slight warm-up as the mid level trough washes out. Monday - Friday... The operational models transition to a broadening southwesterly flow pattern after the upper level ridge axis leans over into the Central Plains. This will allow warmer more seasonal temperatures and humidity back into the region. While the h7 temperatures don`t get overly hot and cap off the environment a lack of any discernible mid/upper level wave or surface boundaries will greatly limit the rain chances. As such will go with a dry forecast until some feature of significance is picked up by the models. && .AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon) Issued at 1253 PM CDT FRI AUG 28 2015 Isolated light afternoon showers east of I-35. VFR conditions through the afternoon hours. Otherwise, scattered convection expected to form by late afternoon over northwest MO and northeast KS along or just ahead of a cold front. Activity expected to advance southeast through the early evening hours but weaken after sunset. Except for a brief period of MVFR ceilings with the strongest storms over northwest MO expect VFR ceilings. Timing remains too uncertain for a 2hr TEMPO group for the Kansas City terminals. Should see MVFR ceilings follow with the passage of the cold front. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ DISCUSSION...MJ AVIATION...MJ
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
344 PM CDT FRI AUG 28 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 315 PM CDT FRI AUG 28 2015 WATER VAPOR IMAGERY SHOWS THAT A SHORTWAVE TROUGH IS MOVING SLOWLY EAST ACROSS MISSOURI AT THIS HOUR. LATEST RUNS OF THE RAP SUGGEST THAT IT WILL TAKE ALL EVENING FOR THIS FIRST SHORTWAVE TO REACH HALFWAY ACROSS THE CWA WHILE A SECOND SHORTWAVE WILL ENTER WESTERN MISSOURI BEHIND IT LATER TONIGHT. LOW LEVEL MOISTURE CONVERGENCE WILL INCREASE ACROSS EASTERN MISSOURI BY LATER THIS EVENING AS LOW LEVEL JET VEERS AND INCREASES IN SPEED SLIGHTLY. THIS SHOULD CAUSE AN INCREASE IN COVERAGE IN SCATTERED SHOWERS AND THUNDERSTORMS BY LATE EVENING AND OVERNIGHT OVER THE REGION BECAUSE OF THE FORCING FROM THE SHORTWAVES AND THE MOISTURE CONVERGENCE. THE 1KM REFLECTIVITY FROM THE CAMS DEPICTS THIS PRETTY WELL. MOS LOWS TONIGHT LOOK REASONABLE GIVEN THE INCREASING DEWPOINTS AHEAD OF THE COLD FRONT CURRENTLY OVER THE CENTRAL PLAINS. BRITT .LONG TERM: (SATURDAY THROUGH NEXT FRIDAY) ISSUED AT 316 PM CDT FRI AUG 28 2015 AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ON SATURDAY AND SATURDAY EVENING AS AN UPPER LEVEL TROUGH MOVES SLOWLY SOUTHEASTWARD THROUGH OUR AREA. IT NOW APPEARS THAT THE COLD FRONT WILL ONLY MAKE IT INTO NORTHEAST MO AND WEST CENTRAL IL BEFORE GRADUALLY DISSIPATING. ONLY SLIGHT COOLING IS EXPECTED ACROSS NORTHEAST MO AND WEST CENTRAL IL SATURDAY AND SATURDAY NIGHT WITH THE REST OF THE AREA SLIGHTLY WARMER AND MORE HUMID DESPITE THE CLOUD COVER ON SATURDAY WITH MAINLY A WEAK SOUTHERLY FLOW. ALTHOUGH THE CHANCE OF PRECIPITATION WILL LESSEN BY LATE SATURDAY NIGHT AND SUNDAY...THERE MAY STILL BE AT LEAST ISOLATED SHOWERS/STORMS ACROSS MAINLY SOUTHEAST MO AND SOUTHWEST IL AS THE WEAKENING UPPER LEVEL TROUGH...SHEAR AXIS MOVES ONLY SLOWLY SOUTHEASTWARD. A WAMER PERIOD OF WEATHER IS FORECAST FOR THE NEXT WORK WEEK DUE TO PERSISTENT SOUTHERLY SURFACE/LOW LEVEL FLOW WITH THE SURFACE/850 MB RIDGE EAST/SOUTHEAST OF OUR AREA...AND AT LEAST UPPER LEVEL RIDGING ACROSS NORTHWEST MO. WILL KEEP THE REMAINDER OF THE FORECAST DRY FOR NOW...ALTHOUGH COULD NOT RULE OUT A FEW SHOWERS/STORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS AS THE MODELS CONTINUE TO DEPICT SOME WEAK MID-UPPER LEVEL TROUGHING...SHEAR AXIS ACROSS MAINLY SOUTHEAST MO AND SOUTHWEST IL. GKS && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1237 PM CDT FRI AUG 28 2015 EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH THIS EVENING. THEN EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS CENTRAL AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS OVERNIGHT THAT WILL EVENTUALLY SPREAD INTO THE ST. LOUIS METRO AREA ON SATURDAY MORNING. SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ON SATURDAY AFTERNOON AROUND THE ST. LOUIS METRO TAF SITES. SPECIFICS FOR KSTL: EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH TONIGHT. THEN SCATTERED SHOWERS WILL MOVE INTO THE AREA BY LATE SATURDAY MORNING WITH AN INCREASING CHANCE OF SCATTERED THUNDERSTORMS AS AN UPPER LEVEL STORM SYSTEM MOVES INTO THE AREA BY LATE SATURDAY AFTERNOON. BRITT && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
316 PM CDT FRI AUG 28 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 315 PM CDT FRI AUG 28 2015 WATER VAPOR IMAGERY SHOWS THAT A SHORTWAVE TROUGH IS MOVING SLOWLY EAST ACROSS MISSOURI AT THIS HOUR. LATEST RUNS OF THE RAP SUGGEST THAT IT WILL TAKE ALL EVENING FOR THIS FIRST SHORTWAVE TO REACH HALFWAY ACROSS THE CWA WHILE A SECOND SHORTWAVE WILL ENTER WESTERN MISSOURI BEHIND IT LATER TONIGHT. LOW LEVEL MOISTURE CONVERGENCE WILL INCREASE ACROSS EASTERN MISSOURI BY LATER THIS EVENING AS LOW LEVEL JET VEERS AND INCREASES IN SPEED SLIGHTLY. THIS SHOULD CAUSE AN INCREASE IN COVERAGE IN SCATTERED SHOWERS AND THUNDERSTORMS BY LATE EVENING AND OVERNIGHT OVER THE REGION BECAUSE OF THE FORCING FROM THE SHORTWAVES AND THE MOISTURE CONVERGENCE. THE 1KM REFLECTIVITY FROM THE CAMS DEPICTS THIS PRETTY WELL. MOS LOWS TONIGHT LOOK REASONABLE GIVEN THE INCREASING DEWPOINTS AHEAD OF THE COLD FRONT CURRENTLY OVER THE CENTRAL PLAINS. BRITT .LONG TERM: (TONIGHT THROUGH THURSDAY) ISSUED AT 340 AM CDT FRI AUG 28 2015 THERE IS GOOD AGREEMENT IN THE 00Z GUIDANCE THAT FRONTAL BOUNDARY AND ASSOCIATED SHORTWAVE SHOULD ALLOW THUNDERSTORMS THREAT TO SLOWLY EXPAND OVER THE NORTHWEST HALF OF THE CWA TONIGHT...WITH THE STL METRO LIKELY ON THE EASTERN EDGE OF THE THREAT DURING THE PREDAWN HOURS. DUE TO PROGGED LOW LEVEL FORCING AHEAD OF THE FRONT, HAVE UPPED POPS INTO LIKELY CATEGORY OVER OUR EXTREME NORTHWEST COUNTIES. HOWEVER...FROM SATURDAY MORNING ON FEATURES AND MODEL SPECIFICS BEGIN TO DIVERGE AND BECOME INCREASING NEBULOUS. WHILE MODELS DO AGREE THAT NORTHERN PORTION OF THE SHORTWAVE WILL CONTINUE TO PRESS INTO THE LOWER GREAT LAKES DURING THE DAY...THEY DISAGREE WITH THEIR HANDLING OF THE SOUTHERN PORTION OF THE SHORTWAVE ENERGY AS IT STRETCHES SOUTHEAST AND POSSIBLY MERGING WITH ANOTHER WEAK CIRCULATION ALONG THE GULF COAST (WHICH APPEARS TO ORIGINATE WITH A BIT OF ENERGY THAT BREAKS OFF FROM THE BASE OF THE CURRENT EAST COAST TROF). GFS AND NAM SUGGEST SOME TYPE OF REMNANT CIRCULATION TAKING UP RESIDENCE IN THE VICINITY OF SW MO BY SUNDAY WITH RESIDUAL SURFACE FRONT BECOMING STATIONARY OVER THE AREA...WHILE ECMWF WANTS TO PUSH THE INCREASINGLY WEAK SHORTWAVE ENERGY AND SURFACE BOUNDARY SOUTH WITH TIME. IF NAM AND GFS SOLUTIONS DO COME TO FRUITION ON SUNDAY...AND IF NAM LOW LEVEL MOISTURE FORECAST (WHICH IS OFTEN TOO HIGH) ALSO VERIFIES...THEN THE DRY FORECAST ON SUNDAY WILL BE IN JEOPARDY. HOWEVER...WOULD LIKE TO SEE ADDITIONAL SUPPORT FOR THESE WEAK FEATURES AND TRENDS BEFORE REINTRODUCING CONVECTION ON SUNDAY. SO FOR NOW HAVE CONTINUED TO TREND THE FORECAST TO THE ECMWF SOLUTION...NAMELY THUNDERSTORM CHANCES EXPANDING SOUTHEAST ACROSS THE CWA DURING THE DAY ON SATURDAY THEN GRADUALLY DIMINISHING FROM NW TO SE LATE SATURDAY AFTERNOON AND SATURDAY NIGHT. DESPITE THE DISCREPANCY IN THE UA PROGS ON SUNDAY...MEDIUM RANGE SOLUTIONS REMAIN IN GOOD RUN TO RUN AND MODEL TO MODEL AGREEMENT THAT WESTERN RIDGE WILL BE EXPANDING EAST INTO THE MID MISSISSIPPI AND OHIO VALLEYS DURING THE UPCOMING WEEK. THIS SHOULD MEAN DRY WEATHER FOR THE FA...ALONG WITH TEMPERATURES REBOUNDING TO LATE SUMMER LEVELS WITH HIGHS IN THE UPPER 80S-LOWER 90S. TRUETT && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1237 PM CDT FRI AUG 28 2015 EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH THIS EVENING. THEN EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS CENTRAL AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS OVERNIGHT THAT WILL EVENTUALLY SPREAD INTO THE ST. LOUIS METRO AREA ON SATURDAY MORNING. SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP ON SATURDAY AFTERNOON AROUND THE ST. LOUIS METRO TAF SITES. SPECIFICS FOR KSTL: EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH TONIGHT. THEN SCATTERED SHOWERS WILL MOVE INTO THE AREA BY LATE SATURDAY MORNING WITH AN INCREASING CHANCE OF SCATTERED THUNDERSTORMS AS AN UPPER LEVEL STORM SYSTEM MOVES INTO THE AREA BY LATE SATURDAY AFTERNOON. BRITT && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1238 PM CDT FRI AUG 28 2015 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 305 AM CDT FRI AUG 28 2015 PCPN CHANCES TODAY AND THEN TEMPERATURES THE NEXT FEW DAYS WILL BE THE MAIN FORECAST CONCERNS. FAIRLY WIDESPREAD AREA OF SHRA AND TSRA WILL CONTINUE TO MOVE EAST THIS MORNING...ASSOCIATED WITH SHORTWAVE TROUGH MOVING THROUGH THE REGION. WATER VAPOR SATELLITE IMAGERY LOOP IN COMBINATION WITH RECENT 500 MB RUC MODEL INITIALIZATIONS SHOWED A FAIRLY STRONG WAVE FOR THIS TIME OF YEAR. 12 HOUR HEIGHT FALLS AT 500 MB WERE UP TO ABOUT 50 METERS. ATMOSPHERE WAS ALSO QUITE MOIST. 700 MB DEWPOINTS OF 4-8 DEGREES C WERE NOTED FROM THE DESERT SW UP INTO WRN KS AND SWRN NE AT 00Z LAST EVENING...AND FORECAST SOUNDINGS SUGGEST PW VALUES ARE AROUND 2 INCHES OR MORE EARLY THIS MORNING. ALTHOUGH THE STRONGEST AREA OF LIFT AND HIGHEST MOISTURE WILL BE SHIFTING EAST OF THE LOCAL AREA...KEPT SOME POPS GOING MUCH OF THE DAY. A WEAKER AREA OF LIFT SHOULD SPREAD SEWD OVER THE REGION AND FORECAST SOUNDINGS STILL SHOW SOME INSTABILITY. WILL KEEP RAIN CHANCES MAINLY AT 20-30 PERCENT AFTER EARLY MORNING ACTIVITY ENDS. RECENT HRRR RUNS AND EVEN THE 00Z NAM SUGGEST PREVIOUS SCENARIO... WITH AT LEAST ISOLD SHRA/TSRA POSSIBLE. LINGERED A SLIGHT CHANCE OF TSRA IN OUR FAR SERN ZONES EARLY THIS EVENING...THEN IT SHOULD BE MAINLY DRY THROUGH SUNDAY. KEPT SOME MENTION OF FOG TONIGHT WITH LIGHT WINDS AND BOTH GFS MOS AND NAM MOS SUGGESTING AT LEAST PATCHY FOG LATE TONIGHT INTO SAT MORNING. DID NOT MENTION FOG SATURDAY NIGHT...BUT SFC RIDGE AXIS WILL BE CLOSE TO THE AREA AND WILL NEED TO MONITOR. RETURN FLOW WITH S/SE SFC WINDS SHOULD THEN STRENGTHEN SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 305 AM CDT FRI AUG 28 2015 MID LEVEL RIDGE EXTENDING FROM NWRN MEXICO UP INTO THE CNTRL PLAINS AND A TROUGH FROM WRN CANADA INTO THE NWRN UNITED STATES WILL BE THE MAIN FEATURES AT THE START OF THIS PERIOD. RIDGE WILL SLIDE SLOWLY SEWD AS THE TROUGH TO THE NORTHWEST DIGS. WEAK RIPPLES MOVING NEWD THROUGH THE REGION COULD BRING SOME TSRA...WITH BEST CHANCES BEING TUE NIGHT AND AGAIN THU NIGHT. TEMPERATURES SHOULD BE AT OR ABOVE NORMAL OVER THE AREA FOR MOST OR ALL OF NEXT WEEK. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1230 PM CDT FRI AUG 28 2015 CEILINGS HAD TRENDED TO MVFR AT ALL THREE TAF SITES AS OF 17Z. THOUGH SOME PATCHY IFR CIGS LINGER NORTH OF KOFK IN SOUTH DAKOTA...LIFTING AND THINNING OF CIGS SHOULD CONTINUE THROUGH 00Z. THEN AS HIGH PRESSURE SETTLES IN ACROSS THE REGION OVERNIGHT...WINDS WILL GO LIGHT AND COMBINED WITH RECENT RAIN AND SURFACE MOISTURE EXPECT IFR VISIBILITIES AND CIGS TO SET IN AFTER 10Z AT ALL THREE TAF SITES. AFTER 16Z CONDITIONS WILL IMPROVE TO MVFR TO VFR. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...MEYER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
145 PM EDT FRI AUG 28 2015 .SYNOPSIS... A WEAK FRONT WILL MEANDER OFF THE THE COAST AS HIGH PRESSURE SLOWLY BUILDS INTO THE CAROLINAS OVER THE WEEKEND. ERIKA IS EXPECTED TO APPROACH THE BAHAMAS AND SOUTH FLORIDA LATE IN THE WEEKEND TRACKING THROUGH FLORIDA INTO EARLY NEXT WEEK...AND POSSIBLY REMAINING ON A MORE WESTWARD TRACK CLOSER TO THE GULF COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...HAVE SLIGHTLY CONTINUED THE DOWNWARD TREND IN SKY COVER AND TEMPTED TO DO THE SAME WITH RAIN CHANCES. NEITHER THE 12KM WRF, HRRR, OR RUC BRING ANYTHING MEASURABLE ONSHORE. WILL WAIT ONE MORE CYCLE TO MONITOR CU DEVELOPMENT AS WELL AS FORMATION OF NE RESULTANT SEABREEZE THAT MAY GRAB AN OFFSHORE SHOWER AND FLING IT ASHORE. BEST CHANCE WOULD BE BALD HEAD ISLAND/SOUTHPORT AREAS. PREVIOUS DISCUSSION FOLLOWS: AS OF 650 AM FRIDAY...HAVE STAYED WITH A DRIER BIAS FOR THIS NEAR TERM FORECAST...AND KEPT THE THREAT FOR LOW CHANCE POPS ACROSS THE COASTAL COUNTIES WITH DIURNALLY DRIVEN CONVECTION THE MAIN EMPHASIS FROM LATE THIS MORNING THRU EARLY THIS EVENING. LATEST WATER VAPOR IMAGERY INDICATES A MUCH DRIER PICTURE COMPARED THIS TIME YESTERDAY MORNING. PROGGED MODEL SOUNDINGS INDICATE DRY AIR BETWEEN 350 MB AND 900 MB BECOMING MORE DOMINANT ACROSS THE FA LATER THIS MORNING THRU TONIGHT AND INTO THE SHORT TERM PERIOD. THE SOMEWHAT STALLED SFC BOUNDARY ORIENTED NE-SW AND PARALLEL TO THE ILM CWA COASTLINE...WILL DRIFT SLIGHTLY FURTHER OFFSHORE THIS PERIOD. THIS HAS ALREADY ALLOWED THE MODEST 1020+ SFC HIGH BROADLY CENTERED OVER THE NE STATES AND MID-ATLANTIC TO RIDGE OR NOSE SOUTH-SOUTHWESTWARD PUSHING DRIER AIR AND LOWER SFC DEWPOINTS TO AND ACROSS THE ILM CWA. ALREADY OBSERVING WIDESPREAD 60S DEWPOINTS ACROSS THE FA...ALL THE WAY TO THE IMMEDIATE COAST. MODELS INDICATE POSSIBLY AROUND 60 THIS AFTN ACROSS THE NORTHERNMOST PORTIONS OF THE FA THIS AFTN WHERE MIXING OF DRIER AIR ALOFT TO THE SFC MAY OCCUR. WITH ALL THIS SAID...THE BEST FORCING/LIFT FOR CONVECTION WILL INITIALLY START JUST ALONG AND OFF THE IMMEDIATE COAST...AND SWITCH FURTHER EAST AND FURTHER OFF THE MAINLAND AS THE BOUNDARY LAYER ASSOCIATED WITH THE STALLED SFC FRONT DRIFTS EASTWARD. HAVE ALSO GONE WITH OVERALL LESS CLOUD COVERAGE...ESPECIALLY TONIGHT WHERE ANY DEBRIS CONVECTIVE CLOUDS WILL EITHER STAY WITHIN THE MEAN FLOW OVER THE ATL WATERS...OR THE DEBRIS CLOUDS THAT PUSH N-NE FROM GA WILL SCOUR OUT A GOOD DEAL PRIOR TO PUSHING ACROSS THE FA. AS FOR TEMPS...LOOKING AT WIDESPREAD 80S FOR MAX TEMPS TODAY...AND WIDESPREAD 60S FOR MINS EXCEPT NEAR 70 ALONG THE IMMEDIATE COAST AND EXTREME SOUTHERN PORTIONS OF THE FA. STAYED WITH A SLIGHTLY COOLER BIAS FOR TONIGHTS MINS USING THE LATEST AVBL MODEL MOS GUIDANCE. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 AM FRIDAY...DRY AIR CONTINUES TO FUNNEL INTO THE AREA IN NORTHERLY FLOW ON BACK END OF LINGERING FRONT/TROUGH/OFF SHORE ON SAT. A WAVE OF LOW PRESSURE DEVELOPS ALONG THE FRONT AND LIFTS OFF TO THE NORTHEAST THROUGH LATE SAT INTO SUN LEAVING WEAK HIGH PRESSURE OVER THE AREA THROUGH SUN NIGHT. THE NORTHERLY FLOW BETWEEN HIGH PRESSURE INLAND AND LOW OFF SHORE ON SAT WILL BEGIN TO VEER AROUND BECOMING MORE ON SHORE THROUGH SUNDAY. ABOVE THE SURFACE...LOW PRESSURE ALOFT OVER THE CENTRAL GULF COAST WILL BEGIN TO MOVE SLOWLY NORTHEAST AND WEAKEN PROVIDING A STEADY SOUTHERLY FLOW OF MOISTURE INTO THE CAROLINAS IN THE LOW TO MID LEVELS SAT NIGHT INTO SUNDAY. THIS IS DEPICTED WELL BY THE MOISTURE PROFILES AND GUIDANCE SHOWING A DEEPENING OF MOISTURE THROUGH THE COLUMN AND AN INCREASE IN CLOUD COVER ON SUNDAY. WITH SUCH DRY AIR IN PLACE IN THE BEGINNING OF PERIOD...EXPECT LIMITED TO NO SHWR ACTIVITY WITH A FEW SHWRS/TSTMS POSSIBLE IN LOCALIZED CONVERGENCE MAINLY ASSOCIATED WITH THE SEA BREEZE OVER THE WEEKEND...WITH MAINLY SOME HIGHER LEVEL CLOUDS AROUND. PCP WATER VALUES DOWN LESS THAN AN INCH OVER INLAND NORTH CAROLINA INCREASE UP TO 1.25 INCHES BY SAT EVE AND UP CLOSE TO 1.5 TO 1.75 INCHES BY SUN AFTN IN A SLOW INCREASE IN MAINLY UPPER LEVEL MOISTURE. THEREFORE EXPECT BETTER CHC OF CONVECTION ON SUNDAY BUT GFS AND ECMWF BOTH SHOWING A WEAKENED ERIKA REACHING OVER SOUTHEAST FLORIDA COAST SUN NIGHT INTO MON WITH EASTERLY FETCH OF MOISTURE REACHING AS FAR NORTH AS SOUTH CAROLINA. OVERALL WESTWARD ADJUSTMENT BY NHC AND GUIDANCE IS EVEN FARTHER WEST. MUCH UNCERTAINTY STILL EXISTS WITH TRACK AND INTENSITY AND THEREFORE WILL NEED TO ADJUST IN FUTURE FORECASTS. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 330 AM FRIDAY...TRENDING DRIER IN OVERALL FORECAST AS LATEST MODEL RUNS SHOW ERIKA OVER FLORIDA ON MONDAY AND THEN TAKING A TURN IN GEORGIA OR POSSIBLY TRACKING ACROSS FLORIDA TOWARD THE GULF COAST. THIS WOULD PRODUCE A GREATER EXTENDED EAST TO NORTHEASTERLY FETCH OVER THE CAROLINAS. FOR NOW KEPT WITH LOWER END CHC POPS AND WITH GREATEST IMPACTS FROM ERIKA STILL EXPECTED MID WEEK...WED INTO THURS. IF ERIKA DOES TAKE A TRACK TO OUR SOUTH MAY END UP WITH MORE IN THE WAY OF SOME GUSTY ON SHORE WINDS AND EXTENDED SWELL ENERGY PRODUCING SOME COASTAL IMPACTS BUT WITH SUCH UNCERTAINTY IN THE MODELS IT IS STILL DIFFICULT TO SAY WITH ANY CERTAINTY. LATEST GFS KEEPS PCP WATER VALUES LOWER THAN 1.5 INCHES THROUGH MOST OF PERIOD OVER NC WITH VALUES REACHING UP CLOSE TO 2 INCHES ON NORTHERN STRETCH OF ERIKA INTO SOUTH CAROLINA. UPPER RIDGE BUILDING OVER THE EASTERN CONUS WILL LEAVE A WEAKNESS BUT TRACK WILL ALSO BE DEPENDENT ON STRENGTH OF ERIKA AS SHE MAKES HER WEST NORTHWEST. THE GFS WANTS TO PULL ERIKA TOWARD THE WEST GETTING PULLED BY THE MID TO UPPER LOW OVER THE WESTERN GULF. OVERALL WENT A BIT MORE OPTIMISTIC FOR OUR AREA WITH A BIT LESS CLOUD COVER AND LESS WIDESPREAD CONVECTION. RAISED MAX TEMPS A BIT...EXPECTING MID TO UPPER 80S MOST PLACES WITH LOWS IN THE LOW TO MID 70S. && .AVIATION /18Z FRIDAY THROUGH TUESDAY/... AS OF 18Z...A FRONTAL SYSTEM IS LOCATED JUST OFF THE COAST THIS AFTERNOON WITH ISOLATED SHOWERS ALONG IT. AN AREA OF HIGH PRESSURE IS TO THE N OF THE TERMINALS AND IS SHOWING SIGNS OF BUILDING SOUTH. WINDS WILL BE NE-ENE THIS AFTERNOON AT 10-15 KTS AT ALL TERMINALS. TEMPO MVFR CIGS WILL BE POSSIBLE EARLY THIS AFTERNOON AT THE COASTAL TERMINALS...BUT GENERALLY SCT/BKN LOW VFR CIGS EXPECTED THROUGH MIDNIGHT Z. SCT SKIES EXPECTED AT KFLO/KLBT. WINDS DECREASE THIS EVENING TO NE AT 5 KT OR LESS. GUIDANCE IS SUGGESTING FOG DEVELOPMENT OVERNIGHT WITH BEST CHANCE AT KLBT WHERE WINDS ARE LIGHTEST. SINCE DEWPOINTS ARE RELATIVELY LOW AND GROUND TEMPS WARM THINK CHANCES ARE LOW ATTM. VFR AFTER SUNRISE WITH NE WINDS. EXTENDED OUTLOOK...PREDOMINATELY VFR WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. BRIEF MORNING FOG/STRATUS IS ALSO EXPECTED EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...MODERATE NE SURGE OF DRY AIR CONTINUES...POSSIBLY STEADY STATE FOR THE NEXT HANDFUL OF HOURS BUT STARTING TO ABATE AROUND MIDDAY. THIS HAS GOTTEN WAVE FACES RATHER STEEP BUT NOT QUITE SCEC-WORTHY IN HEIGHT. THERE ARE NO CHANGES TO THE FORECAST AT THIS TIME. PREVIOUS DISCUSSION FOLLOWS: AS OF 650 AM FRIDAY...THE ENTIRE ILM COASTAL WATERS SHOULD NOW BE ENCOMPASSED WITH A STEADY AND MODEST NE WIND. THE SFC PG FROM THE RIDGING FROM THE 1020+ HIGH FROM THE NORTH WILL BE TIGHT ENOUGH TO PRODUCE A SOLID 15 KT SUSTAINED WIND...EXCEPT INITIALLY 15 TO 20 KT ACROSS THE ILM NC WATERS. LOOKING AT KLTX VWP AND ADJACENT 88D VWPS...WINDS 1K TO 2K FT OFF THE DECK ARE RUNNING NE-ENE AT 15 TO 30 KT. WITH SOME OF THIS MIXING DOWN TO THE OCEAN SFC AS 20+ WIND GUSTS. LOOK FOR A SOLID 15 KT NE WIND SPEED TONIGHT FOR ALL WATERS...WIND DIRECTIONS MAY BRIEFLY VEER TO THE ENE-E NEAR SHORE THIS AFTN/EARLY EVENING DUE TO A RESULTANT WIND BOUNDARY. SIGNIFICANT SEAS WILL RUN A SOLID 4 FT FOR THE ILM NC WATERS FROM CAPE FEAR NORTHWARD THRU THE PERIOD...AND 2 TO 4 FT SOUTH OF THE CAPE. THE 4 TO 6 SECOND PERIOD WIND WAVES WILL DOMINATE THE SIGNIFICANT SEAS...WITH THE UNDERLYING 1 TO 1.5 FOOT ESE GROUND SWELL AT 11-12 SECOND PERIODS REMAINING VISUALLY PRESENT. THE SCATTERED CONVECTION COVERAGE ASSOCIATED WITH THE SOMEWHAT STALLED SFC FRONT...WILL SWITCH TO THE ADJACENT OFFSHORE WATERS. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 330 AM FRIDAY...NORTHEAST WINDS ON SATURDAY BETWEEN HIGH PRESSURE EXTENDING DOWN OVER THE CAROLINAS AND WEAK LOW PRESSURE DEVELOPING ALONG LINGERING BOUNDARY OFF SHORE. AS THIS LOW PULLS AWAY THROUGH SUNDAY...WINDS MAY COME AROUND TO A MORE EASTERLY ON SHORE DIRECTION AROUND HIGH PRESSURE. EXPECT DEEPEST MOISTURE AND CONVECTION MAINLY EAST OF WATERS ASSOCIATED WITH LINGERING BOUNDARY AND WAVE OF LOW PRESSURE ALONG IT. LATEST FORECAST TRACKS WEAKENED ERIKA OVER FLORIDA BY SUNDAY NIGHT INTO EARLY MONDAY. THIS WOULD MAINLY PRODUCE EASTERLY SWELL ENERGY REACHING INTO THE LOCAL WATERS OVER THE WEEKEND WITH SEAS BASICALLY REMAINING 2 TO 4 FT MOST WATERS. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 330 AM FRIDAY...LATEST FORECAST TRACKS ERIKA OVER FLORIDA AND KEEPS TRENDING WESTWARD WITH TIME GETTING PULLED BY MID TO UPPER LOW IN THE WESTERN GULF. MAY SEE WINDS REMAIN E-NE ONLY RISING UP TO 15 KTS. WITH SO MUCH UNCERTAINTY IN MODEL RUNS...WILL NEED TO KEEP AN EYE ON EVOLUTION OF ERIKA. FOR NOW WILL KEEP MAINLY EAST WINDS LESS THAN 15 KTS AND SEAS BASICALLY 2 TO 4 FT WITH A DIMINISHING LONGER PERIOD SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...MBB/DCH SHORT TERM...RGZ LONG TERM...RGZ AVIATION...MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
311 PM CDT FRI AUG 28 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 304 PM CDT FRI AUG 28 2015 WATER VAPOR SHOWS THE MAIN SHORT WAVE OVER NW ONTARIO MOVING TOWARD LAKE SUPERIOR. UPSTREAM IN SOUTHERN MANITOBA ARE SOME OTHER WEAKER SHORT WAVES. A FEW OTHER WEAKER SHORT WAVES ALSO INTO SOUTH CENTRAL NORTH DAKOTA. SO PATTERN IS PRETTY MUDDLED ALOFT. AT THE SFC NOT MUCH BETTER. SHORT RANGE MODELS KEEP INDICATING A SFC TROUGH ADVANCING INTO THE NRN RRV THIS AFTN AND THEN SINKING SOUTH THIS LATE AFTN/EVE. SO FAR REAL HARD TO PICK ONE OUT. WINDS ARE SOUTH-SOUTHWEST TO 25 KTS GRAND FORKS-GRAFTON AND DO SHIFT A TAD MORE WEST LANGDON-DEVILS LAKE REGION AND THEN IN SOUTHERN MANITOBA PRETTY LIGHT AND VARIABLE. SO AT THIS POINT HARD TO TELL IF INDEED A WIND SHIFT LINE WILL ADVANCE SOUTH AS HRRR/RAP/NAM AND NCEP MODELS SAY. PRETTY UNSTABLE IN NRN ERN ND/NW MN WITH MAX MU CAPES IN THE 4000 J/KG RANGE NR ROSEAU-HALLOCK...LIKELY IMPACTED BY HIGHER DEW PTS NOTED BY AWOS`S. THAT SAID CONVECTIVE MODELS CONTINUE TO INDICATE SOME DEVELOPMENT ALONG A WEAK BOUNDARY JAMESTOWN-FARGO-BEMIDJI-PARK RAPIDS AREA 00Z-03Z PERIOD. ALSO DEVELOPMENT WILL CONTINUE OVER LAKE OF THE WOODS. MORE UNCERTAIN IN THE NRN VALLEY AND FAR NW MN WHERE INSTABILITY MAX IS AS CONVECTIVE SHORT RANGE MODELS SHOW NOTHING TO DEVELOP BUT OBS MAY INDICATE ATMOSPHERE PRIMED. SO WILL CONTINUE TO WATCH AND HAVE POPS IN AREAS AS SHORT RANGE MODELS INDICATE BUT ALBEIT A BIT WIDER AREA. INTO SATURDAY THE HEAT AND HUMIDITY IS ON AS UPPER RIDGE BUILDS IN. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 304 PM CDT FRI AUG 28 2015 HOT AND HUMID AND A BIT BREEZY ON SUNDAY. NEXT FRONT DUE TO MOVE THRU LATE SUN NIGHT INTO MONDAY WITH A RISK OF A FEW SHOWERS/STORMS. FOR MONDAY NIGHT THROUGH FRIDAY... THE TREND FOR THIS PERIOD IS GENERALLY WARM AND UNSETTLED. THE PERIOD STARTS OFF WITH SOUTHWEST FLOW ALOFT OVER THE REGION AND A WEAK SHORT WAVE MOVING THROUGH THE AREA MONDAY NIGHT. WEAK WAVES WILL CONTINUE TO AFFECT THE AREA THROUGH MUCH OF THE WEEK...WITH A WARM/HOT AIR MASS IN PLACE AND OCCASIONAL THUNDERSTORM CHANCES. MID 80S TO LOW 90S WILL BE COMMON...WITH SOME MID 90S POSSIBLE AS WELL. TOWARD THE END OF THE WEEK...AN UPPER LEVEL TROUGH/LOW WILL DEEPEN OVER THE WESTERN STATES...WITH A SURFACE LOW LIKELY DEVELOPING IN THE NORTHERN PLAINS. THE GFS AND ECMWF DIFFER ON DETAILS...INCLUDING THE LOCATION OF THE COOLER AIR...BUT BOTH HAVE A SFC LOW IN THE GENERAL REGION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 102 PM CDT FRI AUG 28 2015 MODELS ARE STILL HINTING AT THUNDERSTORM DEVELOPMENT POTENTIALLY THIS AFTERNOON. NAM AND SREF STILL POINT TOWARD ACTIVITY NEAR TVF/GFK BY MID AFTERNOON. HOWEVER...THE LATEST HRRR KEEPS ACTIVITY FURTHER EAST AND SOUTH...MORE IN THE KBJI TO KFAR AREAS AROUND 00Z. REGARDING TS...HAVE MADE ONLY MINOR CHANGES COMPARED TO PREVIOUS FORECAST. NAM AND SREF ARE SHOWING SIGNS OF BR DEVELOPMENT LATE TONIGHT. HAVE KEPT IT AT 5SM AROUND SUNRISE AT GFK/BJI/TVF. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...RIDDLE LONG TERM...KNUTSVIG/RIDDLE AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
107 PM CDT FRI AUG 28 2015 .UPDATE... ISSUED AT 102 PM CDT FRI AUG 28 2015 BIGGEST QUESTION IS WHERE/IF T-STORMS WILL RE-DEVELOP. SFC OBS SHOW A SOUTH-SOUTHWEST WIND TO 25 KTS IN THE NRN VALLEY WITH TEMPS NR 80 AND DEW PTS 65-70 IN MUCH OF THE RRV AND E ND AND FAR NW MN. A WEAK WIND SHIFT IS NOTED BUT MORE IN CNTRL ND ROLLA-CANDO AREA AND INTO SW MANITOBA. CONVECTIVE SHORT RANGE MODELS INDICATE A WEAK WIND SHIFT DROPPING SOUTH THIS AFTN AND SOME STORMS FIRING FARGO-DETROIT LAKES AREA 00Z OR SO. THAT HAS BEEN A CONSISTENT SIGNAL BUT YET TROUGH/WIND SHIFT LINE AS DEPICTED BY HRRR STILL AM NOT SURE WILL OCCUR. TRENDED POPS THE WAY OF THE HRRR AND HOP WRF MODELS WHICH SO THE FARGO-DTL CONVECTION. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 355 AM CDT FRI AUG 28 2015 VISIBILITY ACROSS NORTHWEST MINNESOTA WILL CONTINUE TO BE VARIABLE IN PATCHY FOG THROUGH THE PREDAWN HOURS... THOUGH ANY FOG SHOULD DISSIPATE SHORTLY AFTER SUNRISE. A STRONG THUNDERSTORM COMPLEX IN SOUTHERN MANITOBA THIS HOUR IS EXPECTED TO DIMINISH IN INTENSITY AS IT BRUSHES THE U.S. BORDER ACROSS NORTHERN CAVALIER AND KITTSON COUNTIES AROUND 12Z. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS THEN POSSIBLE THROUGH THE FORENOON THROUGHOUT THE NORTH BORDER COUNTIES... SPREADING ACROSS FAR NORTHCENTRAL MINNESOTA THROUGH THE EARLY AFTERNOON. A SECOND ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE...STARTING IN EAST CENTRAL ND FROM MID AFTERNOON AND SPREADING EASTWARD ALONG AN EAST-WEST ORIENTED TROF AXIS INTO NORTHWEST MINNESOTA INTO THE EARLY EVENING. EXTENT AND SEVERITY OF THESE STORMS WILL DEPEND ON AFTERNOON HEATING... WITH AFTERNOON TEMPERATURES REACHING INTO THE MID 80S IN SPOTS... THUS SOME STORMS COULD PRODUCE SMALL HAIL AND GUSTY WINDS. LATER TONIGHT AND SATURDAY WILL SEE A RETURN TO LIGHT SOUTHERLY FLOW AND A DRIER...MORE STABLE H5 RIDGE BUILDING IN ALOFT. TEMPERATURES OVERALL WILL BE A BIT WARMER THAN SEASONAL NORMALS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 355 AM CDT FRI AUG 28 2015 SATURDAY NIGHT AND SUUNDAY...EXPECT MORE OF THE SAME. WITH A WARM H5 RIDGE ALOFT AND LIGHT SOUTHERLY WINDS AT THE SURFACE...EXPECT SEASONABLY WARM AND DRY CONDITIONS WITH HIGH TEMPERATURES RANGING FRM THEMID 80S IN CENTRAL MINNESOTA LAKES COUNTRY TO THE LOWER 90S IN THE DEVILS LAKE BASIN. MONDAY-THURSDAY...A VERY SUMMER-LIKE WEATHER PATTERN WILL CONTINUE HEADING INTO THE START OF SEPTEMBER. THE UPPER RIDGE WILL FLATTEN EARLY ON WITH SHORTWAVE ENERGY PASSING NORTH ACROSS CANADA. AN ASSOCIATED WEAK SFC BOUNDARY COULD FIRE A FEW STORMS OFF ON MONDAY...ALTHOUGH THE BEST UPPER SUPPORT WILL BE WELL NORTH OVER CANADA. THIS BOUNDARY SHOULD THEN WASH OUT WITHIN PERSISTENT SOUTHWESTERLY FLOW ALOFT. NOT VERY OPTIMISTIC ABOUT PRECIP CHANCES LATER IN THE PERIOD...ALTHOUGH A STORM COULD NOT BE RULED OUT GIVEN THE SOUTHWEST FLOW PATTERN/RATHER MOIST ENVIRONMENT. WARMER MID- LEVEL TEMPS MAY ACT TO SUPPRESS CONVECTION BY WED INTO THUR AS THE PATTERN AMPLIFIES AHEAD OF AN APPROACHING FRONT. DETAILS OUT AT THIS RANGE ARE STILL QUITE UNCERTAIN THOUGH. AVE HIGHS/LOWS FALL INTO THE MID TO UPPER 70S/LOW 50S DURING EARLY SEPT...BUT HIGHS SHOULD SHOULD REACH THE 80S WITH LOWS MAINLY IN THE 60S THROUGH THUR. WED AND POSSIBLY THUR LOOK TO BE WARMEST AS 850 MB TEMPS RISE TO NEAR 25C. SO SOME HIGHS AT OR ABOVE 90 ARE POSSIBLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 102 PM CDT FRI AUG 28 2015 MODELS ARE STILL HINTING AT THUNDERSTORM DEVELOPMENT POTENTIALLY THIS AFTERNOON. NAM AND SREF STILL POINT TOWARD ACTIVITY NEAR TVF/GFK BY MID AFTERNOON. HOWEVER...THE LATEST HRRR KEEPS ACTIVITY FURTHER EAST AND SOUTH...MORE IN THE KBJI TO KFAR AREAS AROUND 00Z. REGARDING TS...HAVE MADE ONLY MINOR CHANGES COMPARED TO PREVIOUS FORECAST. NAM AND SREF ARE SHOWING SIGNS OF BR DEVELOPMENT LATE TONIGHT. HAVE KEPT IT AT 5SM AROUND SUNRISE AT GFK/BJI/TVF. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...GUST LONG TERM...GUST/MAKOWSKI AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
215 PM EDT FRI AUG 28 2015 .SYNOPSIS... WARMING TREND INTO WEEKEND. ISOLATED SHOWER POSSIBLE IN MOUNTAINS. MORE HUMID SUNDAY INTO NEXT WEEK...WITH A BETTER CHANCE OF SHOWERS...ESPECIALLY MONDAY INTO TUESDAY. && .NEAR TERM /THROUGH SATURDAY/... ANOTHER QUIET WEATHER DAY WITH CU FORMING OVER THE HIGHER TERRAIN...AND ALSO IN SE OHIO. NAM CONTINUES TO SHOW SHOWERS DEVELOPING OVER THE MOUNTAINS TODAY. DID LEAVE AN ISOLATED SHOWER IN...BUT THINK THE HRRR HAS A BETTER SOLUTION KEEPING SHOWERS EAST OF CWA WHERE BETTER DEVELOPED CU ARE SHOWING ON SATELLITE. HIGH PRESSURE DRIFTS NORTHEAST TONIGHT...AND MODELS TRYING TO SHOW SOME CLOUDS MOVING IN ACROSS THE SOUTH LATE TONIGHT AND DRIFTING NORTH THROUGH THE DAY. ANTICIPATE VALLEY FOG BEGINNING TO FORM...BUT MAY BE TEMPERED BY CLOUDS...ESPECIALLY ACROSS THE SOUTH. WITH A BIT MORE MOISTURE COMING IN SATURDAY...THINK UPSLOPE FLOW SHOULD LEAD TO AN ISOLATED SHOWER OR TSTORM ACROSS THE MOUNTAINS. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... THE TRANSITION FROM WEAK UPPER RIDGING TO WEAK UPPER TROUGHING OVER THE EASTERN U.S...WHICH WILL ALLOW AN UPPER DISTURBANCE TO EJECT NORTHEASTWARD OUT OF THE NORTHERN GULF OF MEXICO...LOOKS TO BE DELAYED BY ABOUT 24 HOURS. THUS...SUNDAY AFTERNOON CONVECTION LOOKS TO BE MAINLY WIDELY SCATTERED AND OVER THE MOUNTAINS. LOOK FOR TEMPERATURES IN THE UPPER 80S WITH MORE HUMID CONDITIONS SUNDAY. && .LONG TERM /MONDAY THROUGH THURSDAY/... WITH VERY WARM AND MOIST AIR IN PLACE...THE AFOREMENTIONED UPPER DISTURBANCE LIFTING NORTHEAST ACROSS THE AREA MONDAY INTO TUESDAY WILL BRING A BETTER CHANCE OF SHOWERS AND A STORM...ESPECIALLY OVER THE MOUNTAINS. UPPER RIDGING WILL AGAIN BUILD OVER THE AREA FOR THE MIDDLE AND LATER PART OF NEXT WEEK...WITH VERY WARM AND HUMID CONDITIONS PREVAILING...BUT LITTLE RAINFALL. TEMPERATURES WILL GENERALLY BE NEAR 90 DEGREES EACH DAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR EXPECTED TODAY WITH A 3-4KFT CU DECK AND LIGHT FLOW. RIVER VALLEY FOG EXPECTED AGAIN TONIGHT...HOWEVER SOME UNCERTAINTY ON JUST HOW DENSE IT WILL BECOME ACROSS THE SOUTH AS CLOUDS INCREASE DURING THE PRE-DAWN HOURS. HAVE MVFR FOG DEVELOPING HTS-CRW THEN DISSIPATING SHORTLY BEFORE SUNRISE. WHILE FARTHER NORTH HAVE IFR RIVER VALLEY FOG...WITH CLOUDS FILLING IN AFTER SUNRISE. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING/INTENSITY OF DENSE RIVER VALLEY FOG COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H M M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SATURDAY... SPOTTY IFR IN RIVER VALLEY FOG POSSIBLE LATE SATURDAY INTO EARLY SUNDAY DEPENDING ON CLOUDS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/MZ NEAR TERM...MZ SHORT TERM...JMV LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
133 PM EDT FRI AUG 28 2015 .SYNOPSIS... WARMING TREND INTO WEEKEND. ISOLATED SHOWER POSSIBLE IN MOUNTAINS. MORE HUMID SUNDAY INTO EARLY NEXT WEEK...WITH BETTER CHANCE OF SHOWERS...ESPECIALLY LATER SUNDAY INTO SUNDAY NIGHT. && .NEAR TERM /THROUGH SATURDAY/... ANOTHER QUIET WEATHER DAY WITH CU FORMING OVER THE HIGHER TERRAIN...AND ALSO IN SE OHIO. NAM CONTINUES TO SHOW SHOWERS DEVELOPING OVER THE MOUNTAINS TODAY. DID LEAVE AN ISOLATED SHOWER IN...BUT THINK THE HRRR HAS A BETTER SOLUTION KEEPING SHOWERS EAST OF CWA WHERE BETTER DEVELOPED CU ARE SHOWING ON SATELLITE. HIGH PRESSURE DRIFTS NORTHEAST TONIGHT...AND MODELS TRYING TO SHOW SOME CLOUDS MOVING IN ACROSS THE SOUTH LATE TONIGHT AND DRIFTING NORTH THROUGH THE DAY. ANTICIPATE VALLEY FOG BEGINNING TO FORM...BUT MAY BE TEMPERED BY CLOUDS...ESPECIALLY ACROSS THE SOUTH. WITH A BIT MORE MOISTURE COMING IN SATURDAY...THINK UPSLOPE FLOW SHOULD LEAD TO AN ISOLATED SHOWER OR TSTORM ACROSS THE MOUNTAINS. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... HIGH PRESSURE AT THE SFC AND ALOFT WILL CONTINUE TO PRODUCE SUBSIDENCE WITH DRY AIR AND FAIR WEATHER CONDITIONS. THE SFC HIGH PRESSURE WILL MOVE EAST ALLOWING SOUTH TO SOUTHWEST FLOW INTO THE AREA...TO INCREASE TEMPERATURES AND HUMIDITY THROUGH THE WEEKEND. THIS SCENARIO COULD PRODUCE CONVECTION ALONG THE ELEVATED HEAT SOURCES IN THE MOUNTAINS. WENT CLOSER TO THE SUPER BLEND GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD. GENERALLY...EXPECT THE HOTTEST DAY ON SATURDAY WITH TEMPERATURES REACHING THE UPPER 80S LOWLANDS RANGING INTO THE MID 70S HIGHEST ELEVATIONS. && .LONG TERM /MONDAY THROUGH THURSDAY/... THE MAIN CHANGE TO THIS PERIOD WILL BE A STRONGER UPPER DISTURBANCE FROM THE LOWER MISSISSIPPI VALLEY LIFTING NORTHEAST ACROSS THE AREA SUNDAY AND SUNDAY NIGHT...ENHANCING THE POTENTIAL FOR SHOWERS AREA WIDE IN THE VERY WARM AND HUMID AIRMASS IN PLACE. THIS PERIOD STILL SHOWS A BERMUDA HIGH OVER THE WESTERN ATLANTIC EXPANDING WESTWARD. THIS EVOLVES INTO A WELL DEFINED UPPER RIDGE HOLDING OVER THE WESTERN U.S. AND A BUILDING UPPER RIDGE OVER THE WESTERN ATLANTIC...LEAVING A WEAK UPPER TROUGH BETWEEN THESE UPPER RIDGES OVER THE EASTERN U.S.. WITH THE SURFACE HIGH CENTER ALSO BUILDING OFF THE SOUTHEAST COAST...MOISTURE AND HEAT WILL CONTINUE TO INCREASE ON A SOUTHERLY FLOW REGIME THIS WEEKEND INTO EARLY NEXT WEEK. THIS WILL GIVE RISE TO A CHANCE OF MAINLY A DIURNAL SHOWER OR THUNDERSTORM...ESPECIALLY IN THE MOUNTAINS...AND ESPECIALLY SUNDAY AS A VERY WEAK UPPER DISTURBANCE LIFTS NORTHEAST FROM THE GULF STATES. TEMPERATURES WILL GENERALLY APPROACH 90 DEGREES EACH DAY WITH RATHER HUMID CONDITIONS. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... VFR EXPECTED TODAY WITH A 3-4KFT CU DECK AND LIGHT FLOW. RIVER VALLEY FOG EXPECTED AGAIN TONIGHT...HOWEVER SOME UNCERTAINTY ON JUST HOW DENSE IT WILL BECOME ACROSS THE SOUTH AS CLOUDS INCREASE DURING THE PRE-DAWN HOURS. HAVE MVFR FOG DEVELOPING HTS-CRW THEN DISSIPATING SHORTLY BEFORE SUNRISE. WHILE FARTHER NORTH HAVE IFR RIVER VALLEY FOG...WITH CLOUDS FILLING IN AFTER SUNRISE. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: TIMING/INTENSITY OF DENSE RIVER VALLEY FOG COULD VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02 EDT 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M M H H H H H H H M M M EKN CONSISTENCY M H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SATURDAY... SPOTTY IFR IN RIVER VALLEY FOG POSSIBLE LATE SATURDAY INTO EARLY SUNDAY DEPENDING ON CLOUDS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/MZ NEAR TERM...MZ SHORT TERM...ARJ LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS NORMAN OK
309 PM CDT FRI AUG 28 2015 .DISCUSSION... DETERMINING RAIN CHANCES TONIGHT IS THE PRIMARY FORECAST CHALLENGE OF THE DAY. OVERALL...SLIGHTLY LOWERED RAIN CHANCES THROUGH TONIGHT DUE TO WEAK FORCING FOR PRODUCING RAINFALL. DID NOT GO ABOVE 20 PERCENT IN ANY GIVEN LOCATION. THROUGH MIDNIGHT TONIGHT...THINK A FEW LIGHT SHOWERS AND SPRINKLES WILL CONTINUE WHERE THERE IS SOME MID LEVEL MOISTURE CONVERGENCE...GENERALLY NEAR AN ALTUS TO NORMAN TO CHANDLER LINE. A FEW THUNDERSTORMS ARE POSSIBLE AS WELL MAINLY NEAR AN HIGHER INSTABILITY AXIS EXISTS FROM HOLLIS TO CLINTON TO CHEROKEE. ANY STORM IS EXPECTED TO BE SUBSEVERE WITH PERHAPS A FEW STRONG WIND GUSTS UP TO 50 MPH AND SOME LOCALIZED DOWNPOURS. PRECIPITATION COVERAGE MAY DIMINISH AFTER SUNSET DUE TO THE LOSS OF DAYTIME HEATING. RAINFALL SHOULD RAIN SPARSE AND UNDER 0.10 INCH IN MOST LOCATIONS. AFTER MIDNIGHT TONIGHT...A FEW SHOWERS AND PERHAPS A FEW THUNDERSTORMS MAY CONTINUE ACROSS THE AREA...MAINLY SOUTH OF A ELK CITY TO PONCA CITY LINE. LATEST RUC13 SUGGESTED THAT THE 850 MB JET MAY INCREASE OVER WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA WHICH MAY ALLOW FOR INCREASED COVERAGE OF RAIN. HOWEVER... INSTABILITY MAY BE LACKING. THUS...KEPT 20 PERCENT CHANCES IN THESE AREAS. SATURDAY...OVERALL...PARTLY TO MOSTLY SUNNY AND DRY WEATHER CAN BE EXPECTED. WOULD NOT BE COMPLETELY SURPRISED IF A STRAY SHOWER OR STORM OCCURRED SOUTH OF A QUANAH TEXAS TO OKLAHOMA CITY TO CHANDLER LINE...BUT DID NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE. HIGHS WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE...MAINLY IN THE 90S. SATURDAY NIGHT THROUGH FRIDAY...A DRY WEATHER PATTERN IS FORECAST WITH NEAR OR ABOVE AVERAGE TEMPERATURES. THERE ARE SOME MODEL DIFFERENCES MAINLY IN REGARDS TO THE LOCATION AND PROGRESSION A MID/UPPER TROUGH SOMEWHERE OVER THE SOUTHERN PLAINS OR SOUTHEASTERN U.S. AT THIS TIME...THINK THE DEEPEST MOISTURE AND HIGHER RAIN CHANCES WILL STAY EAST OF OKLAHOMA AND NORTH TEXAS...BUT CONFIDENCE IS RATHER LOW. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 68 92 67 92 / 20 10 0 0 HOBART OK 68 96 66 96 / 20 10 10 0 WICHITA FALLS TX 74 98 68 98 / 20 10 10 10 GAGE OK 63 92 60 93 / 10 0 0 0 PONCA CITY OK 67 89 64 91 / 20 10 10 0 DURANT OK 72 94 70 95 / 20 20 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 25/17
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1227 PM CDT FRI AUG 28 2015 .AVIATION... SCATTERED THUNDERSTORMS WILL BE POSSIBLE AT ALL TAF SITES THIS AFTERNOON AND EARLY EVENING BUT CONFIDENCE IN COVERAGE IS TOO LOW TO MENTION IN THE TAF AT THE MOMENT. THESE STORMS WILL RESULT FROM A COLD FRONT TO MOVE THROUGH THIS EVENING. ALTHOUGH WINDS WILL SHIFT TO THE NORTH...SPEEDS ARE EXPECTED TO REMAIN LIGHT. && PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 28 2015/ SHORT TERM... UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE- AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z. ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION... SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING PLAINS THROUGHOUT THE SHORT TERM PERIOD. STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE REGION. BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S. LONG TERM... A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS. MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM AND HAVE KEPT MENTION OUT ATTM. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 61 89 61 91 / 20 10 0 0 TULIA 62 91 61 91 / 20 10 0 0 PLAINVIEW 63 91 63 91 / 30 10 0 0 LEVELLAND 64 91 64 92 / 30 10 10 0 LUBBOCK 65 92 65 93 / 30 10 0 0 DENVER CITY 63 91 63 92 / 30 10 0 0 BROWNFIELD 65 92 65 93 / 30 10 0 0 CHILDRESS 69 96 68 97 / 20 10 0 0 SPUR 69 94 67 96 / 20 10 10 0 ASPERMONT 72 97 70 99 / 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01/99/