Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/14/16


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
220 PM MST TUE APR 12 2016 .SYNOPSIS... MUCH WARMER AND DRIER WEATHER WILL RETURN TO THE REGION WEDNESDAY AND THURSDAY AS HIGH PRESSURE SETTLES OVER THE AREA. ANOTHER PACIFIC WEATHER SYSTEM WILL MOVE THROUGH THE WESTERN UNITED STATES FRIDAY AND SATURDAY BRINGING WINDY CONDITIONS AND MUCH COOLER WEATHER BACK TO THE REGION. && .DISCUSSION... A NICELY DEFINED COLD CORE SHORTWAVE HAS NOW EJECTED INTO SOUTH CENTRAL NEW MEXICO WITH HIGHER HEIGHTS AND SUBSIDENCE FEEDING INTO THE LEFT REAR JET CORE BUILDING INTO SERN CALIFORNIA/SWRN ARIZONA. THE COMBINATION OF WEAK DEFORMATION...MODESTLY STEEP MIDLEVEL LAPSE RATES...AND MINOR INSTABILITY (MUCAPE NEARING 500 J/KG) HAVE SUPPORTED NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS ALONG THE MOGOLLON RIM AND WHITE MOUNTAINS. WHILE STEERING FLOW AND INSTABILITY PARAMETERS MAY SUPPORT SHOWERS/STORMS PROPAGATING INTO PARTS OF SRN GILA COUNTY...VERTICAL AND HORIZONTAL MIXING OF DRY AIR AT LOWER ELEVATIONS ARE CREATING AN ENVIRONMENT MORE HOSTILE TOWARDS MAINTAINING CONVECTION DIRECTED SOUTH DOWN THE I-17 CORRIDOR. A BLEND OF RECENT HRRR ITERATIONS AND HIGH RESOLUTION CONVECTIVE MODELS MOST ACCURATELY DEPICTS THIS EVOLUTION KEEPING CONVECTIVE ELEMENTS PRIMARILY OVER HIGHER TERRAIN FEATURES INTO EARLY EVENING BEFORE DISSIPATING ACTIVITY WITH LOSS OF DAYTIME HEATING. DAMPENED WEAK RIDGING/QUASI-ZONAL FLOW WILL BECOME ESTABLISHED OVER SWRN CONUS WEDNESDAY AND THURSDAY WITH H5 HEIGHTS STAY IN A 573- 579DM RANGE. FULL INSOLATION WILL CREATE DEEP BOUNDARY LAYER MIXING WHILE MODEL H8 TEMPERATURES INCREASE TOWARDS 16-19C RANGE BY THURSDAY AFTERNOON. MODEL SPREAD HAS DECREASED SOMEWHAT WITH RECENT MODEL OUTPUT YIELDING BETTER CONFIDENCE IN BEST PERFORMING GUIDANCE PEAKING AFTERNOON TEMPERATURES IN THE MIDDLE 80S TO LOWER 90S. FRIDAY AND SATURDAY... A COLDER PACIFIC WEATHER SYSTEM WILL DESCEND FROM THE PACIFIC NORTHWEST INTO THE REGION FRIDAY AND FRIDAY NIGHT. DIFFERENCES AMONG ALL OPERATIONAL AND ENSEMBLE MEMBERS ABOUND WITH LITTLE RUN TO RUN CONSISTENCY...MUCH LESS AGREEMENT ON TRACK AND INTENSITY. ONE MEASURE OF CONSISTENCY IS THE CONTINENTAL TRACK OF THE LOW DROPPING SOUTH OVER GREAT BASIN/ROCKIES...WHICH CONTINUES TO FAVOR SHOWER CHANCES DURING THE DAYLIGHT HOURS OVER HIGHER TERRAIN WITH MUCH OF THE LOWER ELEVATION COMMUNITIES CLEARING. THE LARGEST IMPACT FROM THIS WEATHER SYSTEM WILL ALMOST CERTAINLY BE STRONGER WINDS THROUGH SE CALIFORNIA/WRN ARIZONA. OPERATIONAL GFS WIND ANOMALIES ARE TOWARDS THE STRONGER END OF THE MODEL SPREAD ENVELOPE (NEAR 40KT AT H8)...HOWEVER EVEN THE NAEFS AVERAGE V-WIND H8-H7 ANOMALIES LIE TOWARDS THE SEASONALLY EXTREME THRESHOLD. THUS...THERE IS SUFFICIENT SIGNAL TO START MENTIONING BLOWING DUST POTENTIAL FRIDAY AFTERNOON IN ADDITION TO ELEVATED FIRE DANGER. WHILE TAKING A BLENDED APPROACH TO THE EXTENDED FORECAST...COOLER TEMPERATURES ALSO LOOK TO BE EXTREMELY LIKELY...BUT MOISTURE CONTINUES TO LOOK VERY LIMITED WITH EACH MODEL RUN SO HAVE TRIMMED PRECIPITATION CHANCES BACK TOWARDS MAINLY HIGHER TERRAIN AREAS NORTH AND EAST OF THE PHOENIX METRO. SUNDAY INTO EARLY NEXT WEEK... SUBSTANTIAL ENSEMBLE SPREAD EXISTS DURING THIS PERIOD WITH SOME MEMBERS MORE RAPIDLY EJECTING NEGATIVE HEIGHT ANOMALIES INTO THE PLAINS...WHILE OTHERS LINGER A CLOSED LOW NEAR THE LOCAL REGION THROUGH EARLY NEXT WEEK. THUS...FORECAST CONFIDENCE DECREASES SOMEWHAT DURING THIS TIME FRAME ALBEIT WITH NUMERICAL GUIDANCE NOT DISPLAYING THE AMOUNT OF SPREAD THAT OTHERWISE WOULD BE ANTICIPATED. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... DRIER AIR FILTERING IN FROM THE WEST TO PRETTY MUCH CLEAR ALL REMAINING CLOUDS BY LATE THIS EVENING...WITH CLEAR SKIES PREVAILING THROUGH THE REST OF THE TAF PERIOD. WINDS TO REMAIN ON THE LIGHT SIDE...MAINLY 10 KTS OR LESS. WIND DIRECTIONS TO MAINLY FOLLOW TYPICAL DIURNAL TRENDS...BUT WITH TYPICAL WESTERLY WINDS PERSISTING LATER INTO THE EVENING THEN USUAL. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... MOSTLY CLEAR SKIES AND LIGHT DIURNALLY-DRIVEN WINDS TO PREVAIL THROUGH THE TAF PERIOD. && .FIRE WEATHER... THURSDAY THROUGH MONDAY... ABOVE NORMAL TEMPERATURES WILL PERSIST THURSDAY ALONG WITH A SLIGHT DRYING TREND. THEREAFTER...A STRONG LOW PRESSURE SYSTEM WILL DROP DOWN OUT OF THE NORTHERN ROCKIES TOWARDS THE FOUR CORNERS. BIGGEST IMPACT FROM THIS SYSTEM WILL BE AN INCREASE IN WIND. VERY BREEZY TO WINDY CONDITIONS ARE EXPECTED EACH AFTERNOON BEGINNING THURSDAY AND CONTINUING THROUGH SATURDAY. ELEVATED FIRE DANGER WILL BE POSSIBLE FOR A FEW HOURS EACH AFTERNOON THROUGH SATURDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN OF SOUTHWESTERN ARIZONA AND SOUTHEASTERN CALIFORNIA. ALTHOUGH THE DRY AIR WILL PERSIST SUNDAY AND INTO NEXT MONDAY...THE THREAT FOR HAZARDOUS FIRE WEATHER CONDITIONS WILL DECREASE AS THE LOW PRESSURE SYSTEM MOVES EASTWARD AND WINDS SUBSIDE. && .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX PREVIOUS DISCUSSION...MO/MEYERS AVIATION...PERCHA FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
905 AM MST TUE APR 12 2016 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS TO PORTIONS OF SOUTHERN GILA COUNTY TODAY...WHILE MOSTLY SUNNY SKIES WILL BE ON TAP FOR THE LOWER DESERTS OF SOUTHEAST CALIFORNIA AND SOUTH-CENTRAL ARIZONA. MUCH WARMER AND DRIER WEATHER WILL RETURN TO THE ENTIRE FORECAST AREA WEDNESDAY AND THURSDAY. ANOTHER PACIFIC WEATHER SYSTEM WILL MOVE OVER THE WESTERN UNITED STATES FRIDAY AND SATURDAY BRINGING COOLER WEATHER BACK TO THE REGION. && .DISCUSSION... A NICELY DEFINED SMALL COLD CORE WAVE WAS EJECTING EAST INTO SOUTHERN NEW MEXICO THIS MORNING WHILE HIGHER HEIGHTS AND SUBSIDENCE FEEDING INTO THE LEFT REAR JET CORE BUILDS INTO SERN CALIFORNIA/SWRN ARIZONA. 12Z KTWC SOUNDING DATA SAMPLED UNUSUALLY COLD TEMPERATURES ALOFT (H5 MEASURE OF -21C FALLING WELL BELOW THE LOWEST 10TH PERCENTILE CLIMATOLOGICALLY) WITHIN THE IMMEDIATE CYCLONIC PORTION OF THIS WAVE. THE COMBINATION OF VORTICITY ADVECTION...WEAK DEFORMATION...AND MODESTLY STEEP MIDLEVEL LAPSE RATES HAVE SUPPORTED NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS OVER SERN ARIZONA. HOWEVER...RADAR IMAGERY LOOPS SHOW A DISTINCT LIMITING NORTHWARD EXTENT TO ASCENT FIELDS WITH THE DEFORMATION AXIS CUTTING OFF THROUGH THE FAR SOUTHERN PORTIONS OF GILA COUNTY. THEREFORE WHILE ADDITIONAL CONVECTIVE DEVELOPMENT IS LIKELY THROUGHOUT THE WHITE MOUNTAINS...STEERING FLOW AND INSTABILITY PARAMETERS SHOULD LIMIT SHOWERS/STORMS INTO ONLY THE EASTERN PARTS OF SRN GILA COUNTY THE REMAINDER OF THE DAY. A BLEND OF HRRR AND HIGH RESOLUTION CONVECTIVE MODELS MOST ACCURATELY DEPICTS THIS EVOLUTION. OTHERWISE...SOME MINOR ADJUSTMENTS WERE MADE TO REFINE CLOUD COVER AND HOUR TEMPERATURE TRENDS...BUT OVERALL FORECAST THINKING REMAIN ON TRACK TODAY. && .PREVIOUS DISCUSSION... /340 AM MST TUE APR 12 2016/ TUESDAY THROUGH THURSDAY... BEHIND THE DEPARTING LOW...WEAK RIDGING WITH QUASI-ZONAL FLOW WILL SET UP OVER THE DESERT SOUTHWEST THROUGH THE MIDDLE OF THE WEEK WITH 500MB HEIGHTS PERSISTING IN THE 573-579DM RANGE INTO THURSDAY MORNING. NOT MUCH IN THE WAY OF CLOUD COVER IS EXPECTED IN THIS TIME FRAME...SO WITH PLENTY OF SUNSHINE THE LOWER LEVELS OF THE ATMOSPHERE WILL WARM UP...MODEL 850MB TEMPS SUGGESTING AN INCREASE OF ABOUT 3-5 DEGREES INTO THE 17-20C RANGE BY THURSDAY AFTERNOON. THE BEST PERFORMING MODEL GUIDANCE ALSO PEAKS DAYTIME TEMPERATURES IN THE UPPER 80S TO NEAR 90 DEGREES FOR BOTH WEDNESDAY AND THURSDAY. FRIDAY AND SATURDAY...A COLDER PACIFIC WEATHER SYSTEM WILL DESCEND FROM THE PACIFIC NORTHWEST INTO THE REGION FRIDAY AND FRIDAY NIGHT. AT THIS TIME... THE GFS AND ECMWF CONTINUE TO SHOW DIFFERENCES IN THE DEPTH AND TIMING OF THIS SYSTEM...AND THE 12.06 GFS NOW FASTER PLACING A 549DM CLOSED LOW OVER NORTHERN ARIZONA FRIDAY AFTERNOON WHILE THE 12.00 ECMWF IS A BIT SLOWER AND FURTHER EAST ARRIVING WITH A 550DM CLOSED LOW OVER NEW MEXICO SATURDAY MORNING. WITH THIS UNCERTAINTY AND THE CONTINENTAL TRACK OF THE LOW DROPPING SOUTH OVER GREAT BASIN/ROCKIES...WILL CONTINUE TO TAKE A SHOWER CHANCES WILL BE BEST DURING THE DAYLIGHT HOURS OVER HIGHER TERRAIN WITH MUCH OF THE LOWER ELEVATION COMMUNITIES CLEARING. BLENDED APPROACH TO THE EXTENDED FORECAST. COOLER TEMPERATURES AND STRONGER WINDS LOOK TO BE EXTREMELY LIKELY...BUT MOISTURE CONTINUES TO TRICKLE DOWN WITH EACH MODEL RUN...SO HAVE TRIMMED PRECIPITATION CHANCES BACK INTO THE SLIGHT CHANCE CATEGORY AT THIS TIME. SUNDAY INTO EARLY NEXT WEEK...HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION BRINGING MOSTLY CLEAR SKIES AND WARMER TEMPERATURES. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST THIS MORNING ACROSS EASTERN ARIZONA AND WILL GENERALLY REMAIN AROUND 80 MILES EAST OF THE PHOENIX AREA. THIS AFTERNOON...CONVECTION WILL DEVELOP ACROSS THE MOGOLLON RIM BUT AGAIN WILL NOT DIRECTLY IMPACT THE PHOENIX TERMINALS. ACROSS THE LOWER DESERTS...CONDITIONS REMAIN MOIST ENOUGH FOR SOME FEW-SCT CU WITH BASES RISING FROM 6K TO 8K FT THROUGHOUT THE DAY. OTHERWISE...DIURNAL WINDS ARE EXPECTED...GENERALLY REMAINING BELOW 10 KT. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... LIGHT DIURNAL WINDS AND MOSTLY CLEAR SKIES ARE ANTICIPATED AT KIPL/KBLH. NO AVIATION WEATHER CONCERNS EXPECTED. && .FIRE WEATHER... THURSDAY THROUGH MONDAY... ABOVE NORMAL TEMPERATURES WILL PERSIST THURSDAY ALONG WITH A SLIGHT DRYING TREND. THEREAFTER...A STRONG LOW PRESSURE SYSTEM WILL DROP DOWN OUT OF THE NORTHERN ROCKIES TOWARDS THE FOUR CORNERS. BIGGEST IMPACT FROM THIS SYSTEM WILL LIKELY BE AN INCREASE IN WIND. BREEZY TO WINDY CONDITIONS ARE EXPECTED EACH AFTERNOON BEGINNING THURSDAY AND CONTINUING THROUGH SATURDAY. ELEVATED FIRE DANGER WILL BE POSSIBLE FOR A FEW HOURS EACH AFTERNOON THROUGH SATURDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN OF SOUTHWESTERN ARIZONA AND SOUTHEASTERN CALIFORNIA. ALTHOUGH THE DRY AIR WILL PERSIST SUNDAY AND INTO NEXT MONDAY...THE THREAT FOR HAZARDOUS FIRE WEATHER CONDITIONS WILL DECREASE AS THE LOW PRESSURE SYSTEM MOVES EASTWARD AND WINDS SUBSIDE. && .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX PREVIOUS DISCUSSION...MO/MEYERS AVIATION...HIRSCH FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
900 PM PDT WED APR 13 2016 .SYNOPSIS....A FAST MOVING COLD FRONT WILL SPREAD RAIN ACROSS MOST OF THE SAN FRANCISCO BAY REGION LATE WEDNESDAY NIGHT. DRY WEATHER CONDITIONS WILL RETURN TO MOST AREAS BY MID MORNING ON THURSDAY. DRY WEATHER WILL THEN PERSIST FROM FRIDAY THROUGH THE UPCOMING WEEKEND...ALONG WITH A WARMING TREND. TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL OVER THE WEEKEND. COOLING IS THEN EXPECTED MONDAY AND TUESDAY OF NEXT WEEK AS AN UPPER TROUGH APPROACHES THE WEST COAST. && .DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...AFTER SEVERAL CONSECUTIVE DAYS OF CLOUDY TO MOSTLY CLOUDY WEATHER...OUR REGION BASKED UNDER MOSTLY SUNNY SKIES TODAY. HIGHS WERE MOSTLY IN THE 60S. EVENING SATELLITE AND RADAR DATA SHOW A COLD FRONT PUSHING INLAND ACROSS FAR NORTHWEST CALIFORNIA. THIS FRONT HAS HAD A HISTORY OF PRODUCING THUNDERSTORMS ALONG THE OREGON COAST AND NORTHERN CALIFORNIA COAST NORTH OF CAPE MENDOCINO. HOWEVER...THE FRONT IS FORECAST TO WEAKEN CONSIDERABLY AS IT PUSHES SOUTH INTO OUR AREA OVERNIGHT WHICH WILL REDUCE THUNDERSTORM CHANCES TO NEARLY ZERO. BUT THE FRONT WILL MAINTAIN SUFFICIENT MOISTURE AND DYNAMICS TO PRODUCE RAINFALL ACROSS MUCH OF OUR FORECAST AREA OVERNIGHT. THE LATEST NAM AND HRRR MODELS ARE IN GOOD AGREEMENT ON PRECIPITATION TIMING OVERNIGHT. BOTH SPREAD RAIN INTO NORTHERN SONOMA COUNTY JUST PRIOR TO MIDNIGHT AND ACROSS THE ENTIRE NORTH BAY BY 2 AM. RAIN IS THEN EXPECTED TO SPREAD ACROSS THE REMAINDER OF THE SF BAY AREA AND SANTA CRUZ COUNTY BY 4 AM THURSDAY. THE FRONT IS FORECAST TO DISSIPATE BY THE TIME IT REACHES NORTHERN MONTEREY COUNTY AROUND SUNRISE THURSDAY MORNING. LITTLE OR NO RAIN IS EXPECTED SOUTH OF MONTEREY BAY. BECAUSE THIS FRONT WILL BE MOVING THROUGH QUICKLY...RAINFALL AMOUNTS ARE FORECAST TO BE LIGHT. MOST MODEL OUTPUT FORECASTS QPF OF A QUARTER INCH OR LESS BY SUNRISE THURSDAY MORNING...ALTHOUGH THE LATEST HRRR FORECASTS ISOLATED AMOUNTS OF UP TO A HALF INCH IN THE NORTH BAY. VERY LITTLE IN THE WAY OF POST-FRONTAL PRECIPITATION IS EXPECTED WITH THIS SYSTEM. THE NAM AND GFS FORECAST SOME LIGHT SHOWER ACTIVITY ACROSS NORTHERN SONOMA COUNTY ON THURSDAY. OTHERWISE ALL MODEL DATA INDICATE A DRY DAY FOR THE MOST PART. THE AIRMASS BEHIND THE FRONT WILL BE QUITE COOL...WITH 850 MB TEMPS FORECAST TO DROP AS LOW AS ZERO DEGREES C IN THE NORTH BAY ON THURSDAY MORNING. BUT THERE SHOULD BE PLENTY OF SUN BY MIDDAY TO OFFSET THIS COOL AIRMASS TO SOME EXTENT AND AFTERNOON HIGHS ARE EXPECTED TO BE ONLY SLIGHTLY COOLER THAN AVERAGE. BRISK NORTHWEST WINDS WILL DEVELOP NEAR THE COAST BY THURSDAY AFTERNOON WITH LOCAL GUSTS UP TO 30 MPH POSSIBLE. AN UPPER RIDGE IS FORECAST TO QUICKLY DEVELOP JUST OFFSHORE BY FRIDAY...WHICH WILL NOT ONLY BEGIN TO WARM THE AIRMASS OVER OUR AREA...BUT ALSO TURN THE FLOW MORE NORTHERLY AND BRING A DRIER AIRMASS INTO OUR REGION. EXPECT HIGH TEMPERATURES ON FRIDAY TO BE AS MUCH AS 15 DEGREES WARMER IN THE NORTH BAY VALLEYS WHERE DOWNSLOPE WARMING IS EXPECTED. ELSEWHERE WARMING ON FRIDAY WILL BE MORE MODEST. THE WARMING TREND WILL THEN CONTINUE THROUGH THE UPCOMING WEEKEND AS THE UPPER RIDGE BUILDS INLAND OVER CA AND LIGHT OFFSHORE FLOW DEVELOPS. WIDESPREAD HIGH TEMPERATURES IN THE UPPER 70S AND LOWER 80S ARE FORECAST BY SUNDAY...AT BOTH INLAND AND COASTAL LOCATIONS. THE UPPER RIDGE AXIS IS FORECAST TO MOVE OFF TO OUR EAST BY MONDAY WHILE AN UPPER TROUGH APPROACHES THE WEST COAST...AND ONSHORE FLOW WILL RETURN. THESE DEVELOPMENTS WILL RESULT IN SIGNIFICANT COOLING ON MONDAY AND TUESDAY. THE MEDIUM RANGE MODELS AGREE THAT THE TROUGH WILL LIFT QUICKLY TO THE NORTHEAST AS IT APPROACHES THE COAST AND SO PRECIPITATION POTENTIAL APPEARS MINIMAL LATE MONDAY NIGHT AND TUESDAY. && .AVIATION...AS OF 4:50 PM PDT WEDNESDAY...THE CURRENT VISIBLE SATELLITE IMAGE IS SHOWING MOSTLY CLEAR SKIES OVER THE TERMINALS THIS EVENING...HOWEVER A COLD FRONT IS QUICKLY APPROACHING NORTHERN CALIFORNIA AT THIS HOUR. THE COLD FRONT WILL SLIDE SOUTH OVERNIGHT RESULTING IN LIGHT RAIN AT ALL TERMINALS LATE TONIGHT. THE FRONT WILL BE OUT OF THE AREA BY SUNRISE FRIDAY MORNING. VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST MIDNIGHT. LIGHT RAIN IS ANTICIPATED BETWEEN 1000Z AND 1200Z WITH SHOWERS POSSIBLE FROM 1200Z TO 1500Z. BREEZY WESTERLY WINDS WILL REACH 18 KT WITH GUSTS TO 24 KT. WINDS ARE EXPECTED TO EASE BY 0600Z. CONFIDENCE IS MODERATE. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST MIDNIGHT. LIGHT RAIN IS ANTICIPATED BETWEEN 1100Z AND 1500Z. WESTERLY WINDS WILL REACH 10 TO 12 KT WITH GUSTS TO 18 KT. WINDS ARE EXPECTED TO EASE BY 0400Z. && .MARINE...AS OF 8:59 PM PDT TUESDAY...GUSTY NORTHERLY WINDS WILL PREVAIL ALONG THE CENTRAL COAST AS HIGH PRESSURE REMAINS OFF THE COAST. NORTHWESTERLY SWELLS WILL BUILD WEDNESDAY AND PEAK ON THURSDAY BEFORE SUBSIDING BY THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY SOUTH TO MONTEREY COUNTY SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...ROUGH BAR ADVISORY FOR SF BAR FROM 9 PM && $$ PUBLIC FORECAST: DYKEMA AVIATION: LARRY MARINE: SIMS VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1056 PM PDT MON APR 11 2016 .SYNOPSIS....TONIGHT WILL BE ANOTHER CLOUDY ONE WITH LIGHT DRIZZLE POSSIBLE ALONG THE COAST. MOSTLY DRY WEATHER WITH SEASONABLE TEMPERATURES WILL PERSIST THROUGH EARLY WEDNESDAY. RAIN WILL BE POSSIBLE WEDNESDAY NIGHT INTO THURSDAY AS A WEATHER SYSTEM PUSHES ACROSS THE FORECAST AREA. DRY WEATHER WILL THEN RETURN LATE IN THE WEEK AND PERSIST INTO THE WEEKEND ALONG WITH A GRADUAL WARMING TREND. && .DISCUSSION...AS OF 8:41 PM PDT MONDAY...THE FINAL LOW LIGHT VISIBLE SATELLITE IMAGE WAS SHOWING STRATOCUMULUS CLOUDS OVER MUCH OF THE AREA THIS EVENING WITH STRATUS OVER THE COASTAL WATERS. THE CURRENT SATELLITE WATER VAPOUR IMAGE IS SHOWING A LOW PRESSURE SYSTEM SPINNING IN THE GULF OF ALASKA WHICH IS SLIDING A BOUNDARY SOUTHEAST TOWARDS THE CALIFORNIA COAST. THIS FRONT MAY PUSH THE PREVIOUSLY MENTIONED STRATUS CLOUDS INLAND OVERNIGHT AND MAY ALSO PROVIDE ENOUGH LIFT TO RESULT IN DRIZZLE ALONG THE COAST. HAVE UPDATED THE FORECAST TO INCLUDE COASTAL DRIZZLE DURING THE OVERNIGHT HOURS. THE 1200Z ECMWF AND 1800Z GFS40 HAVE INITIALIZED WELL WITH THE CURRENT SYNOPTIC WEATHER PATTERN AND REMAIN IN GOOD AGREEMENT THROUGH EARLY NEXT WEEK. BOTH MODELS SHOW THE JET STREAM INTERACTING WITH THE PREVIOUSLY MENTIONED GULF OF ALASKA LOW PRESSURE SYSTEM...SPINNING OFF A SECONDARY LOW WHICH WILL ENTER THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA WEDNESDAY...SLIDING A FRONT ACROSS NORTHERN AND CENTRAL CALIFORNIA WEDNESDAY NIGHT INTO THURSDAY. THIS FRONT WILL PROVIDE THE AREA WITH A POSSIBILITY OF LIGHT RAIN. ONCE THE FRONT PASSES A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN PACIFIC AND MUCH OF CALIFORNIA...PROVIDING US WITH A WARM UP AND DRY WEATHER FOR THE WEEKEND. THE CURRENT FORECAST PACKAGE HANDLES THIS SCENARIO WELL AND NO FURTHER UPDATES ARE NEEDED AT THIS TIME. && .AVIATION...AS OF 10:53 PM PDT MONDAY...MVFR CIGS WITH PATCHY IFR CIGS/VSBYS TONIGHT DUE TO A WEAK LOWER LEVEL COOL FRONTAL BOUNDARY SLIDING S-SE OVER THE AREA INTERACTING WITH RESIDUAL LOWER LEVEL MOIST AIR. THE 00Z NAM MODEL IS CONSISTENT WITH FORECASTING DECENT 925 MB LEVEL COOLING INTO TUESDAY MORNING...AS MUCH AS 2 TO 5 CELSIUS AREA-WIDE...RESULTING IN A SLIGHT CHANCE SPRINKLES OR PATCHY DRIZZLE. AT THE 850 MB LEVEL AND HIGHER THE SYNOPTIC PATTERN FEATURES A WEAK RIDGE OVER NORCAL. PARTIAL CLEARING RETURNS TUESDAY WITH AREAS OF COASTAL LOW CLOUDS AND/OR FOG MOVING BACK TO THE IMMEDIATE COAST TUESDAY EVENING PER THE LATEST WRF MODEL BOUNDARY LAYER HUMIDITY FORECAST. VICINITY OF KSFO...WINDS MAINLY LIGHT SW-W TONIGHT BECOMING W WITH GUSTS TO 20-25 KNOTS BY MID AFTERNOON TUESDAY. VFR/MVFR PERSISTS BUT LOWER CONFIDENCE REGARDING LOW CLOUD COVERAGE TUE MORNING. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...MVFR WITH PATCHY IFR LATE TONIGHT AND TUESDAY MORNING. PATCHY DRIZZLE OR A SPRINKLE IS A POSSIBILITY IN THE AREA LATE TONIGHT AND TUESDAY MORNING. && .MARINE...AS OF 8:44 PM PDT MONDAY...INCREASING NORTHWEST WINDS TONIGHT AND INTO TOMORROW THEN FURTHER STRENGTHENING THIS WEEK. AN ENERGETIC NORTHWEST SWELL TRAIN WILL ENTER THE COASTAL WATERS ON WEDNESDAY AND PERSIST THROUGH THE REMAINDER OF THE WORK WEEK. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...SCA...PT ARENA TO PT REYES 0-10 NM FROM 4 AM SCA...PT REYES TO PIGEON PT 0-10 NM FROM 4 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM && $$ PUBLIC FORECAST: LARRY AVIATION: CANEPA MARINE: DRP VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
Area Forecast Discussion National Weather Service Sacramento CA 942 PM PDT MON APR 11 2016 .Synopsis... Scattered showers are possible across the mountains and northern Sacramento Valley through early Wednesday. A colder system will bring rain and snow to the area Wednesday night into Thursday. && .Discussion... Scattered showers are continuing along the northern coastal range with isolated showers from around Blue Canyon northward over the Sierra Nevada. The HRRR model indicates showers continuing in the same general areas overnight other than some showers spreading over a greater portion of Shasta County. On Tuesday a shortwave moves into the Pacific Northwest and may continue to provide enough moisture and instability to bring some showers to all the mountain areas and the north end of the valley. A colder low pressure system will begin to move into the northern end of the state Wednesday night. Snow levels should fall below major pass levels with this system and result in travel impacts. Snow levels should fall on Thursday to between 4000 to 5000 feet. The NAM this evening has lower precipitation amounts than the earlier model run with around a tenth of an inch around Sacramento up to a half an inch at Redding. The mountains also are indicating less output with around a quarter inch at Blue Canyon to a half inch over the northern mountains. Unstable air moving in Thursday morning may generate some thunderstorms in the interior. the GFS has slightly higher amounts for the valley with a quarter to an inch of rainfall in the mountains. && .EXTENDED DISCUSSION (Friday THROUGH Monday) Medium range models in general agreement in dropping closed upper low from NV/UT into the Desert SW on Fri as the Ern Pac upper ridge nears the W Coast. Nly flow aloft will prevail over Norcal with lingering flurries possible over the Sierra Crest. These digging systems create breezy/windy N to E winds over interior Norcal and should continue into Sat as the ridge shifts inland and pressures rise over the Pac NW/Great Basin. Winds slacken on Sun as the ridge shifts over NorCal. Some modeling differences on Mon as the GFS is faster in breaking down or shifting the ridge Ewd than the GEM/ ECMWF...and at this point...leaning toward the slower solutions. Temps warm from near to slightly below normal on Fri to 10 to 18 degrees above normal Sat thru Mon with Sun/Mon the warmest days. Max temps expected to climb well into the 80s in the Valley and 60s/70s in the foothill/mtns. JHM && .AVIATION... Mainly VFR conditions will continue through Tuesday across Valley TAF sites. Local MVFR/IFR conditions continue in the foothills and mountains with showers and fog through Tuesday. Light south winds will remain below 10 kts across the Valley. Dang && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
936 PM EDT WED APR 13 2016 .UPDATE...SHORT WAVE INTERACTING WITH ISENTROPIC LIFT OVER THE AREA HAS RESULTED IN WIDESPREAD SHOWERS MOVING INTO THE AREA FROM THE GULF COAST. WSR-88D AND MSAS ANALYSIS ALSO INDICATING A WEAK LOW WAS WELL OFFSHORE THE NE FL COAST (AROUND 90 NM OFFSHORE FROM SHARPENING COASTAL TROUGH). THE 18Z NAM AND HIGH-RES HRRR INDICATE THIS LOW WILL MEANDER SSW OVERNITE WHICH LIKELY HELP MAINTAIN THE LOW LEVEL WEDGE IN PLACE. HAVE BUMPED POPS UP ACROSS NE FL TO ACCOUNT FOR WIDESPREAD SHOWERS MOVING INTO THE WESTERN ZONES WHICH WILL OVERSPREAD MUCH OF NE FL IN THE NEXT COUPLE OF HOURS AND OVERNITE. THERE MAY BE A FEW ISOLATED ELEVATED STORMS ACROSS THE FAR SOUTHERN ZONES WHERE THERE IS SOME MARGINAL INSTABILITY. STRONG LOW LEVEL WEDGE IN PLACE WITH SHARP COASTAL TROUGH OFFSHORE WILL ALSO RESULT IN LOW CLOUDS ALONG THE COAST SPREADING INLAND TONIGHT. EXPECTING RAINFALL AMOUNTS FROM A HALF TO ONE INCH ACROSS THE SUWANNEE VALLEY AND FAR SOUTHERN ZONES WITH SLIGHTLY LESSER AMOUNTS ELSEWHERE. && .AVIATION...CONTINUED ONSHORE FLOW IS EXPECTED TO RESULT IN LOWERING STRATUS TONIGHT WITH IFR CIGS DEVELOPING AT MOST TAF SITES. ALSO EXPECTING WIDESPREAD SHOWERS TO MOVE INTO MUCH OF THE AREA IN THE NEXT SEVERAL HOURS. && .MARINE...THE COMBINATION OF STRONG HIGH PRESSURE TO THE NORTH AND A COASTAL TROUGH DEVELOPING ALONG THE EAST COAST OF FLORIDA...WILL RESULT IN A PROLONGED PERIOD OF ENHANCED ONSHORE FLOW. THE RESULTANT PRESSURE GRADIENT WILL BE STRONGEST NORTH OF SAINT AUGUSTINE...SO SMALL CRAFT IS IN EFFECT NORTH OF THERE. THIS PATTERN IS EXPECTED TO CONTINUE INTO THE WEEKEND...AND THE ADVISORY WILL LIKELY BE EXTENDED...AND POSSIBLY EXPANDED. RIP CURRENTS: MODERATE RISK DUE TO STRONG ONSHORE FLOW AND BUILDING SEAS AND SURF. && .PRELIMINARY POINT TEMPS/POPS... AMG 57 63 53 64 / 40 60 60 50 SSI 62 64 59 68 / 40 70 70 70 JAX 63 71 59 75 / 60 60 60 60 SGJ 65 75 64 78 / 60 60 60 60 GNV 64 78 59 78 / 60 50 40 60 OCF 64 81 63 80 / 50 40 30 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR COASTAL WATERS FROM ALTAMAHA SOUND TO FERNANDINA BEACH FL OUT 20 NM- COASTAL WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL OUT 20 NM-WATERS FROM ALTAMAHA SOUND GA TO FERNANDINA BEACH FL FROM 20 TO 60 NM-WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL FROM 20 TO 60 NM. && $$ PP/JDS/AW
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
920 PM EDT WED APR 13 2016 .UPDATE... TONIGHT...SEA BREEZE BOUNDARY GENERATED CONVECTION WAS DROPPING SOUTH SOUTHEAST OVER INTERIOR SECTIONS. THESE CELLS SO FAR THIS AFTERNOON/EVENING HAVE BEEN DIMINISHING AFTER MOVING WELL AWAY FROM THE EAST COAST SEA BREEZE BOUNDARY...SO THINK THE CONVECTION WILL MAINLY STAY INLAND...BUT A SMALL CHANCE FOR SHOWERS/STORMS STILL EXISTS FROM SOUTH BREVARD SOUTHWARD THROUGH ABOUT MIDNIGHT. MEANWHILE A CLUSTER OF CONVECTION AHEAD OF A VORT MAX...THAT HAS BEEN LUMBERING EASTWARD ALONG THE NORTHERN GULF OF MEXICO COAST... WAS STARTING TO PUSH INLAND FROM APALACHEE BAY. CLOUD TOPS HAD BEEN WARMING AND AND LIGHTNING DIMINISHING...BUT RECENT TRENDS SUGGEST THAT THE HRRR MODEL...WHICH HAS BEEN SHOWING CONVECTION REINVIGORATING...WILL NEED TO BE SHOWN SOME RESPECT. SO PLAN TO RETAIN CHANCE POPS OVERNIGHT. WEAK FRONTAL BOUNDARY MAY PROVIDE A LITTLE ADDED LIFT IN THE NORTH SO WILL ALSO KEEP SMALL MENTION OF THUNDER THERE. && .AVIATION...SMALL CLUSTER OF SHOWERS/STORMS MOVING SOUTH/SOUTHEAST FROM KISM-KMCO SHOULD STAY WEST OF KMLB-KSUA THROUGH LATE EVENING BUT SOME SHOWERS ARE POSSIBLE. ELSEWHERE...EXPECT POCKETS OF MVFR AS ANOTHER AREA OF SHOWERS MOVES ACROSS THE TERMINALS THIS EVENING AND MAYBE EVEN A LITTLE PAST MIDNIGHT...MAINLY KISM-KMLB NORTHWARD. A FEW LIGHTNING STRIKES ARE POSSIBLE...ESPECIALLY NORTH OF KMCO- KTIX. THE ATMOSPHERE WILL BE MORE MOIST ON THU SO EXPECT A CHANCE OF SHOWERS/STORMS A LITTLE EARLIER...CLOSE TO 18Z. && .MARINE... TONIGHT-THURSDAY...WINDS SHOULD BE LIGHT...LESS THAN 10 KNOTS SO THERE WILL BE NO WIND/SEA CONCERNS. MAIN MARINER CONCERN WILL BE SCATTERED SHOWERS AND ISOLATED STORMS. THE MODELS SHOW CONVECTION OVERNIGHT AND INTO THE MORNING OFFSHORE FROM ABOUT THE CAPE NORTHWARD. ALSO EXPECT A CHANCE OF STORMS MOVING OFFSHORE DURING THE AFTERNOON ALONG MOST OF THE COAST. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ FORECASTS...LASCODY IMPACT WX...SPRATT
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1000 PM EDT WED APR 13 2016 .SYNOPSIS... HIGH PRESSURE WILL WEDGE INTO THE FORECAST AREA FROM THE NORTH THROUGH SATURDAY. A FRONT WILL BE STALLED JUST SOUTH OF THE AREA. IT WILL BE COOL WITH POSSIBLE SHOWERS...MAINLY FRIDAY AND FRIDAY NIGHT AND IN THE SOUTH SECTION OF THE FORECAST AREA. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE NORTH WILL CONTINUE TO DOMINATE. SATELLITE TRENDS INDICATED AN INCREASE IN MOISTURE WILL OCCUR AHEAD OF A MID-LEVEL SHORTWAVE TROUGH NOW ALONG THE GULF COAST. WEAK ISENTROPIC LIFT WILL INCREASE MAINLY OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA. LATEST REGIONAL RADAR COMPOSITE SHOWING MOSTLY LIGHT RAIN OVER PORTIONS OF CENTRAL AND SOUTHERN GA...WITH SOME LIGHT RAIN EDGING CLOSE TO THE CSRA. HOWEVER...NOT SURE IF THIS LIGHT PRECIPITATION NEAR THE CSRA IS REACHING THE GROUND AT THIS TIME. THE LATEST SPC HRRR DISPLAYED RAIN REACHING THE SAVANNAH RIVER TOWARDS SUNRISE. AT THIS TIME DO NOT PLAN ANY CHANGES TO POPS SINCE ONGOING FORECAST LOOKS GOOD. THE MAV AND MET MOS PLUS SREF MEAN SUPPORTED CHANCE POPS IN THE SOUTHERN COUNTIES LATE...WHICH LOOKS REASONABLE. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/... CONSIDERABLE UNCERTAINTY IN THE SHORT TERM PERIOD...ESPECIALLY THROUGH FRIDAY NIGHT...IN TERMS OF SHOWER COVERAGE AND THEREFORE TEMPERATURES WITH LARGE GRADIENTS IN BOTH EXPECTED ACROSS THE AREA. THURSDAY...A CLOSED UPPER LEVEL LOW WILL SLOWLY SHIFT ACROSS THE LOWER/MIDDLE MISSISSIPPI VALLEY AS A WEDGE OF HIGH PRESSURE AT THE SURFACE MAINTAINS A COOL NORTHEAST FLOW ACROSS THE AREA. DEEPENING MOISTURE PROFILES AND STRENGTHENING ISENTROPIC ASCENT COULD SUPPORT ISOLATED TO SCATTERED SHOWERS ACROSS THE CSRA AND SOUTHERN MIDLANDS...WITH DRIER LOW LEVEL AIR PREVENTING ANY SHOWERS FROM DEVELOPING FARTHER NORTH. TEMPERATURES WILL ONLY REACH HIGHS IN THE LOWER 60S ACROSS SOUTHERN AREAS WHERE THE SHOWER POTENTIAL IS GREATEST...AND MID 60S ACROSS CENTRAL AND NORTHERN AREAS. THURSDAY NIGHT THROUGH FRIDAY NIGHT...A DEVELOPING COASTAL TROUGH COMBINED WITH THE PERSISTENT WEDGE OF HIGH PRESSURE BUILDING FROM THE NORTH WILL RESULT IN A TIGHT SURFACE PRESSURE GRADIENT ACROSS THE AREA...WITH BREEZY NORTHEAST WINDS AT TIMES. THE FORMATION OF THE COASTAL TROUGH WILL ALLOW THE DEEP LAYERED MOISTURE TO ADVECT NORTHWARD INTO THE AREA. MEANWHILE IN THE UPPER LEVELS OF THE ATMOSPHERE...AN OMEGA BLOCK WILL FORM...HOLDING THE CLOSED LOW JUST TO THE WEST. THE COMBINATION OF ABUNDANT MOISTURE...FORCING FOR ASCENT AHEAD OF THE CLOSED LOW AND ISENTROPIC LIFT WILL RESULT IN UNSETTLED CONDITIONS...WITH SHOWERS LIKELY ACROSS THE CSRA AND A CHANCE OF SHOWERS JUST ABOUT EVERYWHERE ELSE ACROSS THE FORECAST AREA. NIGHTTIME LOWS WILL BE IN THE 40S...BUT DAYTIME HIGHS ON FRIDAY COULD RANGE FROM THE MID AND UPPER 50S IN THE CSRA AND LOWER MIDLANDS TO THE LOWER AND MID 60S ACROSS THE CENTRAL AND NORTHERN MIDLANDS. SATURDAY...THE UPPER LEVEL LOW WILL WEAKEN AND SHIFT SOUTH AND SOUTHEAST OF THE AREA...WHILE AT THE SURFACE THE CENTER OF HIGH PRESSURE WILL SHIFT SOUTH INTO THE MID-ATLANTIC REGION AND SHUNT THE DEEPEST MOISTURE OUT OF THE AREA. ANY LINGERING ISOLATED SHOWERS ACROSS THE CSRA SHOULD TAPER OFF IN THE MORNING...WITH CLEARING SKIES IN THE AFTERNOON. THE NORTHEAST FLOW WILL KEEP COOL TEMPERATURES IN PLACE HOWEVER...WITH HIGHS GENERALLY IN THE MID 60S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... UPPER LEVEL RIDGING WILL STRENGTHEN TO THE WEST AS SURFACE HIGH PRESSURE INITIALLY BUILDS OVER THE REGION THEN SHIFTS INTO THE WESTERN ATLANTIC LATE IN THE PERIOD. STRONG SUBSIDENCE AND A LACK OF DEEP MOISTURE WILL RESULT IN RAIN-FREE CONDITIONS. TEMPERATURES WILL ALSO WARM THROUGH THE PERIOD...RISING ABOVE NORMAL BY EARLY NEXT WEEK. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... MAINLY VFR CONDITIONS EXPECTED NORTH OF SURFACE FRONT THROUGH THE PERIOD AT ALL SITES. CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD FROM THE SOUTHWEST IN THE UPPER-LEVELS...AND THE SOUTHEAST IN MID-LEVELS. THICKER MI-LEVEL CLOUDS EXPECTED AT AGS/DNL DUE TO CLOSER PROXIMITY TO SURFACE FRONT. CAN NOT RULE OUT A BRIEF MVFR CONDITION AT AGS/DNL...BUT CONFIDENCE NOT HIGH ENOUGH TO PLACE IN TAFS. ALL OTHER SITES CONTINUE VFR. WINDS LIGHT AND VARIABLE OVERNIGHT...THEN INCREASE OUT OF THE EAST LATE THURSDAY MORNING...WITH GUSTY CONDITIONS ALSO DEVELOPING INTO THE AFTERNOON. THIS IS SUPPORTED BY CURRENT GUIDANCE. EXTENDED AVIATION OUTLOOK...A FRONT WILL REMAIN JUST SOUTH OF THE AREA THROUGH SATURDAY. MOISTURE ASSOCIATED WITH THE FRONT MAY LEAD TO PERIODS OF MVFR OR IFR CONDITIONS MAINLY AT THE SOUTHERN TERMINALS OF AGS...DNL...AND OGB THROUGH FRIDAY NIGHT. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. && $$ SYNOPSIS...99 NEAR TERM...99 SHORT TERM...99 LONG TERM...99 AVIATION...99
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
827 PM EDT WED APR 13 2016 .SYNOPSIS... STRONG HIGH PRESSURE WILL WEDGE INTO THE REGION FROM THE NORTH INTO THE WEEKEND...WHILE AN UPPER LEVEL LOW SLOWLY MOVES ACROSS THE SOUTHEAST. NEXT WEEK...THE UPPER LEVEL LOW WILL MOVE AWAY...AND HIGH PRESSURE WILL SHIFT OVER THE REGION. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... HIGH PRESSURE WILL CONTINUE TO WEDGE DOWN THE EASTERN SEABOARD AND INTO THE FORECAST AREA TONIGHT. MEANWHILE A SERIES OF UPPER DISTURBANCES WILL RIPPLE ACROSS THE AREA. A RELATIVELY STRONG MOISTURE GRADIENT EXISTS FROM NORTH TO SOUTH WITH PWATS RANGING FROM 0.90" IN THE NORTH TO 1.25" ALONG THE ALTAMAHA RIVER. AT A MINIMUM THE UPPER LEVEL ENERGY WILL MAINTAIN EXTENSIVE MID AND HIGH CLOUDS ACROSS THE AREA. LOW-LEVEL MOISTURE BEING SOMEWHAT LIMITED OVER SOUTHERN SC SHOULD SUPPRESS PRECIPITATION THROUGH EARLY THURSDAY MORNING. FARTHER SOUTH WE COULD SEE SOME LIGHT RAIN SPREAD INTO FAR SOUTHERN ZONES LATE THIS EVENING AND EVENTUALLY MOISTEN THE LOW-LEVELS FARTHER NORTH SUCH THAT PRECIPITATION COULD REACH SOUTHERN SC ZONES. OVERALL WE BELIEVE THE GLOBAL MODELS ARE A BIT TOO AGGRESSIVE WITH THE PRECIPITATION RAPIDLY EXPANDING NORTH AFTER MIDNIGHT. THE LATEST HIGH-RES MODELS SUCH AS THE RUC AND HRRR ARE MUCH MORE CONSERVATIVE WITH PRECIP COVERAGE AND WE HAVE TRENDED IN THAT DIRECTION. COLD ADVECTION WILL GRADUALLY DROP TEMPS INTO THE LOW TO MID 50S BY DAYBREAK THURSDAY. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... THIS PERIOD WILL FEATURE CLOUDY SKIES...BREEZY AND COOL CONDITIONS. PERSISTENT...STRONG NORTHEAST WINDS WILL IMPACT THE COAST. MEANWHILE...THE PRECIPITATION FORECAST CONTINUES TO TREND WETTER. AT THE SURFACE...MODELS ARE IN GOOD AGREEMENT SHOWING A STRONG WEDGE OF HIGH PRESSURE PREVAILING TO OUR NORTH THROUGH SATURDAY. MEANWHILE...A PROGRESSIVE UPPER LEVEL LOW WILL BECOME TRAPPED WITHIN A BLOCKING PATTERN OVER THE EASTERN CONUS THURSDAY. THIS FEATURE WILL SLOWLY MOVE EASTWARD...ACROSS THE SOUTHEAST THROUGH SATURDAY. THURSDAY...THERE WILL BE A SLIGHT CHANCE OF SHOWERS ACROSS THE TRI- COUNTY AREA. ANY SHOWERS THAT DEVELOP ARE EXPECTED TO BE LIGHT. THIS IS BECAUSE THE WEDGE OF HIGH PRESSURE WILL HAVE RELATIVELY DRIER AIR TO OUR NORTH. MEANWHILE...ACROSS OUR SOUTHERN AND WESTERN COUNTIES...MOISTURE TRANSPORT FROM THE EAST/SOUTHEAST WILL PUSH PWATS ABOVE 1 INCH...AND MODEST FORCING FOR ASCENT SUPPORTED BY AN UPPER SHORTWAVE TROUGH/ASSOCIATED POOL OF VORTICITY AHEAD OF THE PARENT UPPER LOW WILL SUPPORT INCREASING COVERAGE OF OVERRUNNING PRECIPITATION IN THIS AREA. BY LATE THURSDAY AFTERNOON...POPS RAMP TO AROUND 50 PERCENT SOUTH OF INTERSTATE 16...ALTHOUGH THIS COULD PROVE TO BE CONSERVATIVE. THIS REGIME WILL CONTINUE THURSDAY NIGHT...AND DEEP LAYERED MOISTURE SHOULD SPREAD NORTH/DEEPER INTO THE FORECAST AREA. ALTHOUGH THE NORTHWARD PROGRESS REMAINS SOMEWHAT UNCERTAIN DUE TO THE LINGERING INFLUENCE OF THE WEDGE OF HIGH PRESSURE. POPS INCREASE TO LIKELY SOUTH OF INTERSTATE 16 AND ARE GRADUATED THROUGH CHANCE TO SLIGHT CHANCE FAR NORTH. AGAIN...THESE POPS COULD PROVE TO BE CONSERVATIVE ESPECIALLY ACROSS SOUTHERN COUNTIES WHERE THE PROBABILITY FOR LOCALLY HEAVY RAIN COULD INCREASE AS PWATS INCREASE TO AROUND 1.50 INCH. FRIDAY COULD REMAIN WET AS THE MAIN UPPER LOW LUMBERS ACROSS THE REGION. POPS ARE GRADUATED FROM LIKELY SOUTH OF THE TRI-COUNTY TO CHANCE ACROSS THE TRI-COUNTY. PWATS AROUND 1.50 INCH COULD SUPPORT LOCALLY HEAVY RAIN ACROSS OUR SOUTHERNMOST COUNTIES. THURSDAY THROUGH FRIDAY...THE NORTHWARD PROGRESS OF DEEP MOISTURE REMAINS SOMEWHAT UNCERTAIN DUE TO THE CONTINUED INFLUENCE OF THE WEDGE OF HIGH PRESSURE/DRIER AIR TO THE NORTH AND THE POTENTIAL FOR ORGANIZED CONVECTION SOUTH OF THE REGION...DISRUPTING THE NORTHWARD PROGRESS OF HIGHER PWATS/SIGNIFICANT PRECIPITATION. HIGH TEMPS WILL REMAIN IN THE 60S THURSDAY/FRIDAY...AND NIGHTTIME LOWS IN THE 40S INLAND/NORTH AND 50S ELSEWHERE WILL BE COMMON. FRIDAY...A FEW INLAND LOCATIONS COULD STRUGGLE TO EVEN REACH 60F. THE UPPER LOW IS EXPECTED TO DRIFT OVER THE REGION FRIDAY NIGHT. DEEPEST MOISTURE COULD BEGIN TO RETREAT SOUTHEAST OF THE REGION AS DRIER AIR BEGINS TO SPREAD IN FROM THE NORTH...SO POPS GRADUALLY DIMINISH TO CHANCE/SLIGHT CHANCE. HOWEVER...CONFIDENCE IN THE PACE OF THIS SCENARIO AND IN THE LATEST POP FORECAST REMAINS LOW. SATURDAY...THE UPPER LOW IS EXPECTED TO PHASE WITH ATLANTIC LOW PRESSURE AND ADVANCE TOWARD THE SOUTHEAST/AWAY FROM THE REGION AS DEEP LAYERED RIDGING BEGINS TO EXPAND INTO THE REGION FROM THE NORTH/NORTHWEST. THIS SCENARIO SHOULD TRANSLATE TO A DRYING/MODEST WARMING TREND AS INDICATED BY DECREASING POPS AND TEMPS RECOVERING TO AROUND 70F. HOWEVER...CONFIDENCE IN THE PACE OF IMPROVEMENT REMAINS LOW...AND ISOLATED/SCATTERED SHOWERS AND COOLER TEMPERATURES COULD LINGER OVER A LARGER AREA LONGER THAN EXPECTED. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AN EXPANDING UPPER RIDGE WILL CONTINUE TO PUSH THE UPPER LOW/TROUGH SOUTH OF THE REGION AND SURFACE HIGH PRESSURE WILL SHIFT OVER THE SOUTHEAST. AS A RESULT...EXPECT A TRANSITION TO DRIER/MUCH WARMER CONDITIONS THIS PERIOD...AND TEMPERATURES AT OR ABOVE 80F WILL BECOME COMMON AWAY FROM THE BEACHES NEXT WEEK. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS BEGIN THE 00Z TAF PERIOD THOUGH INCREASING LOW- LEVEL MOISTURE ACROSS SOUTHEAST GA IS EXPECTED TO BRING BACK MVFR CEILINGS AT KSAV LATE THIS EVENING...EXTENDING THROUGH MID THURSDAY MORNING. AT KCHS...A DEEPER DRY LAYER MAY KEEP CEILINGS JUST ABOVE 3000 FT OVERNIGHT INTO THURSDAY SO WE ARE SHOWING A VFR FORECAST. THE LATEST GFS MOS GUIDANCE AND SHORT-RANGE ENSEMBLE SUPPORT THIS MORE OPTIMISTIC FORECAST. RAIN CHANCES WILL BE INCREASING LATE TONIGHT INTO THURSDAY ACROSS SOUTHEAST GA. GIVEN THE UNCERTAINTY IN THE NORTHWARD SPREAD OF THE RAIN...WE SIMPLY MAINTAINED A VICINITY SHOWER MENTION AT KSAV BEGINNING LATE THURSDAY MORNING. EXTENDED AVIATION OUTLOOK...AN UPPER LEVEL LOW WILL IMPACT THE REGION THURSDAY NIGHT THROUGH SATURDAY. FLIGHT RESTRICTIONS ARE EXPECTED AT KSAV THURSDAY NIGHT THROUGH FRIDAY NIGHT WHILE PERIODS OF FLIGHT RESTRICTIONS ARE POSSIBLE AT KCHS. && .MARINE... TONIGHT...THE WATERS WILL REMAIN SANDWICHED BETWEEN THE SURFACE HIGH PRESSURE WEDGE INLAND AND RELATIVELY LOWER PRESSURE OFFSHORE. WHILE SMALL VARIATIONS IN THE GRADIENT WILL IMPACT SUSTAINED WIND SPEEDS...SMALL CRAFT ADVISORY CONDITIONS DUE TO STRONG GUSTS AND SEAS WILL PERSIST THROUGH THE NIGHT. THROUGH THE FIRST PART OF THE WEEKEND...THIS PERIOD WILL FEATURE HAZARDOUS WINDS/SEAS DUE TO A TIGHT PRESSURE GRADIENT AND A WELL/MIXED MARINE BOUNDARY LAYER BETWEEN A STRONG WEDGE OF HIGH PRESSURE AND A SURFACE LOW/TROUGH OVER THE GULF STREAM. SOLID SMALL CRAFT ADVISORY CONDITIONS ARE CERTAIN INTO THIS WEEKEND. GALES COULD ALSO DEVELOP IN SOME AREAS...BUT FORECAST CONFIDENCE IN THE TIMING AND LOCATION REMAINS TOO LOW TO JUSTIFY ANY WATCHES AT THIS TIME. LATE WEEKEND/EARLY NEXT WEEK...GRADUAL IMPROVEMENT IS EXPECTED AS HIGH PRESSURE SHIFTS SOUTH TOWARD THE WATERS. RIP CURRENTS...THERE WILL BE AN ELEVATED RISK OF RIP CURRENTS FOR THE NEXT SEVERAL DAYS DUE TO STRONG ONSHORE WINDS AND LARGE NE SWELL. && .TIDES/COASTAL FLOODING... STRONG AND PERSISTENT NORTHEAST WINDS WILL CONTRIBUTE TO ELEVATED TIDES AND INCREASED PROBABILITIES OF BEACH EROSION INTO THE WEEKEND. DESPITE SALT WATER LEVELS 1 TO 2 FEET ABOVE NORMAL ASTRONOMICAL TIDES...HIGH TIDE LEVELS ARE EXPECTED TO REMAIN BELOW COASTAL FLOOD ADVISORY THRESHOLDS. HOWEVER...DUE TO THE EXTENDED NATURE OF THIS EVENT WE WILL CONTINUE TO ASSESS TIDAL DEPARTURE TRENDS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...HIGH RISK FOR RIP CURRENTS THROUGH THURSDAY EVENING FOR GAZ117- 119-139-141. SC...HIGH RISK FOR RIP CURRENTS THROUGH THURSDAY EVENING FOR SCZ048>051. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT SUNDAY FOR AMZ350-352-354. SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR AMZ374. SMALL CRAFT ADVISORY UNTIL 5 PM EDT SATURDAY FOR AMZ330. && $$ SYNOPSIS... NEAR TERM...JRL SHORT TERM...SPR LONG TERM...SPR AVIATION...JRL MARINE... TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
741 PM EDT WED APR 13 2016 .SYNOPSIS... HIGH PRESSURE WILL WEDGE INTO THE FORECAST AREA FROM THE NORTH THROUGH SATURDAY. A FRONT WILL BE STALLED JUST SOUTH OF THE AREA. IT WILL BE COOL WITH POSSIBLE SHOWERS...MAINLY FRIDAY AND FRIDAY NIGHT AND IN THE SOUTH SECTION OF THE FORECAST AREA. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE NORTH WILL CONTINUE TO DOMINATE. SATELLITE TRENDS INDICATED AN INCREASE IN MOISTURE WILL OCCUR AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. THE MODELS SHOWED WEAK ISENTROPIC LIFT DEVELOPING MAINLY IN THE SOUTH PART. LATEST REGIONAL RADAR COMPOSITE INDICATING AN AREA OF LIGHT TO MODERATE SHOWERS OVER SW GA AND THE FL PANHANDLE SLOWLY MOVING TO THE EAST. THE LATEST HRRR DISPLAYED RAIN REACHING THE CSRA TOWARD SUNRISE. THE 12Z ARW AND SPC WRF KEPT THE RAIN SUPPRESSED SOUTH OF THE AREA. THE MAV AND MET MOS PLUS SREF MEAN SUPPORTED CHANCE POPS IN THE SOUTH PART LATE AND WE LEANED TOWARD THAT GUIDANCE. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/... CONSIDERABLE UNCERTAINTY IN THE SHORT TERM PERIOD...ESPECIALLY THROUGH FRIDAY NIGHT...IN TERMS OF SHOWER COVERAGE AND THEREFORE TEMPERATURES WITH LARGE GRADIENTS IN BOTH EXPECTED ACROSS THE AREA. THURSDAY...A CLOSED UPPER LEVEL LOW WILL SLOWLY SHIFT ACROSS THE LOWER/MIDDLE MISSISSIPPI VALLEY AS A WEDGE OF HIGH PRESSURE AT THE SURFACE MAINTAINS A COOL NORTHEAST FLOW ACROSS THE AREA. DEEPENING MOISTURE PROFILES AND STRENGTHENING ISENTROPIC ASCENT COULD SUPPORT ISOLATED TO SCATTERED SHOWERS ACROSS THE CSRA AND SOUTHERN MIDLANDS...WITH DRIER LOW LEVEL AIR PREVENTING ANY SHOWERS FROM DEVELOPING FARTHER NORTH. TEMPERATURES WILL ONLY REACH HIGHS IN THE LOWER 60S ACROSS SOUTHERN AREAS WHERE THE SHOWER POTENTIAL IS GREATEST...AND MID 60S ACROSS CENTRAL AND NORTHERN AREAS. THURSDAY NIGHT THROUGH FRIDAY NIGHT...A DEVELOPING COASTAL TROUGH COMBINED WITH THE PERSISTENT WEDGE OF HIGH PRESSURE BUILDING FROM THE NORTH WILL RESULT IN A TIGHT SURFACE PRESSURE GRADIENT ACROSS THE AREA...WITH BREEZY NORTHEAST WINDS AT TIMES. THE FORMATION OF THE COASTAL TROUGH WILL ALLOW THE DEEP LAYERED MOISTURE TO ADVECT NORTHWARD INTO THE AREA. MEANWHILE IN THE UPPER LEVELS OF THE ATMOSPHERE...AN OMEGA BLOCK WILL FORM...HOLDING THE CLOSED LOW JUST TO THE WEST. THE COMBINATION OF ABUNDANT MOISTURE...FORCING FOR ASCENT AHEAD OF THE CLOSED LOW AND ISENTROPIC LIFT WILL RESULT IN UNSETTLED CONDITIONS...WITH SHOWERS LIKELY ACROSS THE CSRA AND A CHANCE OF SHOWERS JUST ABOUT EVERYWHERE ELSE ACROSS THE FORECAST AREA. NIGHTTIME LOWS WILL BE IN THE 40S...BUT DAYTIME HIGHS ON FRIDAY COULD RANGE FROM THE MID AND UPPER 50S IN THE CSRA AND LOWER MIDLANDS TO THE LOWER AND MID 60S ACROSS THE CENTRAL AND NORTHERN MIDLANDS. SATURDAY...THE UPPER LEVEL LOW WILL WEAKEN AND SHIFT SOUTH AND SOUTHEAST OF THE AREA...WHILE AT THE SURFACE THE CENTER OF HIGH PRESSURE WILL SHIFT SOUTH INTO THE MID-ATLANTIC REGION AND SHUNT THE DEEPEST MOISTURE OUT OF THE AREA. ANY LINGERING ISOLATED SHOWERS ACROSS THE CSRA SHOULD TAPER OFF IN THE MORNING...WITH CLEARING SKIES IN THE AFTERNOON. THE NORTHEAST FLOW WILL KEEP COOL TEMPERATURES IN PLACE HOWEVER...WITH HIGHS GENERALLY IN THE MID 60S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... UPPER LEVEL RIDGING WILL STRENGTHEN TO THE WEST AS SURFACE HIGH PRESSURE INITIALLY BUILDS OVER THE REGION THEN SHIFTS INTO THE WESTERN ATLANTIC LATE IN THE PERIOD. STRONG SUBSIDENCE AND A LACK OF DEEP MOISTURE WILL RESULT IN RAIN-FREE CONDITIONS. TEMPERATURES WILL ALSO WARM THROUGH THE PERIOD...RISING ABOVE NORMAL BY EARLY NEXT WEEK. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... MAINLY VFR CONDITIONS EXPECTED NORTH OF SURFACE FRONT THROUGH THE PERIOD AT ALL SITES. CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD FROM THE SOUTHWEST IN THE UPPER-LEVELS...AND THE SOUTHEAST IN MID-LEVELS. THICKER MI-LEVEL CLOUDS EXPECTED AT AGS/DNL DUE TO CLOSER PROXIMITY TO SURFACE FRONT. CAN NOT RULE OUT A BRIEF MVFR CONDITION AT AGS/DNL...BUT CONFIDENCE NOT HIGH ENOUGH TO PLACE IN TAFS. ALL OTHER SITES CONTINUE VFR. WINDS LIGHT AND VARIABLE OVERNIGHT...THEN INCREASE OUT OF THE EAST LATE THURSDAY MORNING...WITH GUSTY CONDITIONS ALSO DEVELOPING INTO THE AFTERNOON. THIS IS SUPPORTED BY CURRENT GUIDANCE. EXTENDED AVIATION OUTLOOK...A FRONT WILL REMAIN JUST SOUTH OF THE AREA THROUGH SATURDAY. MOISTURE ASSOCIATED WITH THE FRONT MAY LEAD TO PERIODS OF MVFR OR IFR CONDITIONS MAINLY AT THE SOUTHERN TERMINALS OF AGS...DNL...AND OGB THROUGH FRIDAY NIGHT. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
659 PM EDT TUE APR 12 2016 .SYNOPSIS... A COLD FRONT WILL PUSH THROUGH THE FORECAST AREA LATER THIS EVENING. HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTH THROUGH FRIDAY...WITH COOLER TEMPERATURES AND SOMEWHAT UNSETTLED CONDITIONS POSSIBLE TOWARD THE CENTRAL SAVANNAH RIVER AREA. A GRADUAL WARMING TREND WILL BEGIN OVER THE WEEKEND WITH DRIER CONDITIONS EXPECTED AS HIGH PRESSURE PREVAILS. THE HIGH WILL SHIFT OFFSHORE INTO THE ATLANTIC EARLY NEXT WEEK...RESULTING IN ABOVE NORMAL TEMPERATURES. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A COLD FRONTAL BOUNDARY WILL MOVE THROUGH THE MIDLANDS AND CSRA LATER THIS EVENING. CONVECTION...WHICH FORMED ALONG A WEAK SURFACE WAVE ON THE FRONT AND AHEAD OF A WEAK UPPER-LEVEL SHORT WAVE...IS SLOWLY WEAKENING WITH THE LOSS OF DAYTIME HEATING. LATEST SPC HRRR INDICATING CONVECTION SHOULD END 02Z-04Z. A RIDGE OF HIGH PRESSURE BUILDING IN FROM THE MID ATLANTIC STATES BEHIND THE FRONT WITH NORTHEAST LOW LEVEL FLOW DEVELOPING THIS EVENING. N/NE WINDS WILL BRING DRIER AIR IN FROM THE NORTH. WINDS MAY BE GUSTY OVERNIGHT. ENHANCED LOW LEVEL MIXING SHOULD SUPPORT TEMPERATURES IN THE UPPER 40S NORTH TO MID 50S SOUTH. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/... WEDNESDAY AND WEDNESDAY NIGHT...A CLOSED UPPER LEVEL LOW WILL TRACK ACROSS THE CENTRAL PLAINS...WITH WEAK RIDGING ALOFT EXPECTED AHEAD OF IT OVER OUR REGION. AT THE SURFACE...A WEAK IN-SITU WEDGE PATTERN IS EXPECTED AS HIGH PRESSURE BUILDS FROM THE NORTH. DESPITE A GOOD AMOUNT OF MOISTURE ALOFT...THE LOWER LEVELS OF THE ATMOSPHERE APPEAR RATHER DRY AND THERE IS VERY LITTLE FORCING FOR ASCENT ON WEDNESDAY...SO HAVE REMOVED ANY MENTION OF PRECIPITATION FROM THE FORECAST. HOWEVER ON WEDNESDAY NIGHT...THERE IS SOME SHORT WAVE ENERGY ALOFT THAT APPROACHES FROM THE SOUTHWEST AHEAD OF THE UPPER LOW AND THE FORECAST WILL SHOW ISOLATED TO SCATTERED SHOWERS ACROSS THE SOUTHERN MIDLANDS AND ESPECIALLY THE CSRA. TEMPERATURES WILL BE BELOW NORMAL GIVEN CLOUD COVER AND THE NORTHEASTERLY FLOW AT THE SURFACE WITHIN THE WEDGE...WITH HIGHS IN THE MID TO UPPER 60S. NIGHTTIME LOWS WILL RANGE FROM THE LOWER AND MID 40S ACROSS THE NORTHERN MIDLANDS WHERE THERE MAY BE LESS CLOUD COVER...TO THE UPPER 40S AND LOWER 50S ACROSS THE CSRA. THURSDAY AND THURSDAY NIGHT...THE CLOSED UPPER LOW WILL LINGER ACROSS THE CENTRAL MISSISSIPPI VALLEY WHILE SURFACE HIGH PRESSURE CONTINUES TO BUILD FROM THE NORTH. THE DEEPEST MOISTURE AND STRONGEST ISENTROPIC ASCENT WILL REMAIN TO OUR SOUTH...BUT CANNOT RULE OUT ISOLATED SHOWERS ACROSS PARTS OF THE CSRA. THE REMAINDER OF THE AREA SHOULD REMAIN RAIN-FREE. BELOW NORMAL HIGH TEMPERATURES WILL CONTINUE WITHIN THE PERSISTENT IN-SITU WEDGE...WITH HIGHS IN THE MID 60S. LOWS AT NIGHT WILL BE IN THE MID TO UPPER 40S. FRIDAY...FRIDAY HAS THE POTENTIAL TO BE THE MOST UNSETTLED DAY OF THE WEEK...ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA...AS AN OMEGA BLOCK KEEPS THE CLOSED UPPER LOW JUST WEST OF THE REGION. DEEPENING MOISTURE...SHORT WAVE ENERGY ALOFT AND STRENGTHENING ISENTROPIC ASCENT WILL SUPPORT A CHANCE OF SHOWERS ACROSS THE CSRA AND SOUTHERN MIDLANDS...WITH A SLIGHT CHANCE ELSEWHERE TO THE NORTH. NORTHEAST FLOW AT THE SURFACE AND INCREASED PRECIPITATION CHANCES WILL RESULT IN COOL TEMPERATURES...WITH HIGHS IN THE LOWER TO MID 60S. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... MODELS DIFFER ON THE SYNOPTIC PATTERN HEADING INTO THE WEEKEND...WITH THE GFS SHOWING THE OMEGA BLOCK ERODING AND THE UPPER LOW PASSING SOUTH OF THE REGION WHILE THE ECMWF HAS THE UPPER LOW BASICALLY BECOMING ABSORBED IN THE FLOW ALOFT. EITHER WAY...SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE NORTH AND WITH LIMITED MOISTURE AND FORCING FOR ASCENT LACKING...WILL GO WITH A DRY FORECAST AFTER FRIDAY NIGHT AND THROUGH THE REMAINDER OF THE WEEKEND. UPPER LEVEL RIDGING WILL THEN BEGIN TO BUILD EARLY NEXT WEEK AS HIGH PRESSURE AT THE SURFACE BECOMES ESTABLISHED OVER THE WESTERN ATLANTIC...SUPPORTING WARMER TEMPERATURES AND RAIN-FREE CONDITIONS. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... PERIODS OF MVFR CONDITIONS...ALONG WITH A CHANCE FOR SHOWERS EXPECTED THROUGH THE AFTERNOON INTO THE EARLY EVENING. COLD FRONT WILL MOVE THROUGH THE TAF SITES FROM LATE AFTERNOON INTO THE EVENING. SATELLITE INDICATING CLOUDS BREAKING UP FROM WEST TO EAST. MVFR CIGS ALONG WITH THE CHANCE FOR SHOWER WILL CONTINUE AHEAD OF THE FRONT. DRIER AIR AND VFR CONDITIONS RETURNING TONIGHT. SOUTHERLY WINDS AHEAD OF THE FRONT WILL BECOME NORTHEAST 10 TO 15 KNOTS AND GUSTY OVERNIGHT AS HIGH PRESSURE RIDGES IN FROM THE NORTH. POTENTIAL FOR THUNDERSTORMS THIS AFTERNOON REMAINS TOO LOW TO INCLUDE ATTM. EXTENDED AVIATION OUTLOOK...LOW CONFIDENCE IN FLIGHT RESTRICTIONS DUE TO LOW CEILINGS AND ISOLATED/SCATTERED SHOWERS THROUGH FRIDAY NIGHT...ESPECIALLY AT KAGS AND KDNL. OTHERWISE VFR CONDITIONS EXPECTED TO PREVAIL. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
303 PM EDT TUE APR 12 2016 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. A WEDGE OF HIGH PRESSURE WILL THEN BUILD INTO THE REGION FROM THE NORTH AND WILL PREVAIL INTO THE WEEKEND. THE CENTER OF THE HIGH WILL SHIFT SOUTH TOWARD THE REGION EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THIS AFTERNOON...SHOWER ACTIVITY HAS BEEN PRETTY MEAGER SO FAR AND TIME IS RUNNING OUT FOR MEANINGFUL RAINS TO DEVELOP. DESPITE STRONG UPPER FORCING ASSOCIATED WITH THE LEFT EXIT REGION OF THE UPPER JET, THE APPROACHING DRY SLOT IS QUICKLY EATING AWAY AT THE RIBBON OF MOISTURE THAT IS TRAVERSING THE AREA. SOME TSTMS HAVE RECENTLY DEVELOPED ACROSS FAR INTERIOR SOUTHEAST GEORGIA SOUTH OF THE ALTAMAHA RIVER WHERE TEMPS HAVE WARMED INTO THE UPPER 70S. SOME OF THIS ACTIVITY COULD BRUSH THE FAR SOUTHERN ZONES OVER THE NEXT FEW HOURS. POPS HAVE BEEN REALIGNED TO TAKE CURRENT TRENDS INTO ACCOUNT. TONIGHT...DRY CONDITIONS EXPECTED OVERNIGHT AS SHORTWAVE ENERGY EXITS THE AREA AND A PRONOUNCED DRY SLOT PROPAGATES IN FROM THE WEST. THE COLD FRONT IS ON TARGET TO BACKDOOR INTO THE REGION EARLY TUESDAY MORNING WITH A COMPLETE WIND SHIFT TO THE NORTH AND NORTHEAST EXPECTED BY DAYBREAK. LOWS WILL RANGE FROM THE MID 50S NORTH OF I-26 TO THE UPPER 50S/LOWER 60S ELSEWHERE--WARMEST ALONG THE GEORGIA COAST WHERE ONSHORE WINDS WILL HELP TO MODERATE TEMPERATURES. IT WILL BECOME BREEZY ALONG THE LOWER SOUTH CAROLINA COAST, ESPECIALLY THE BEACHES OF CHARLESTON COUNTY, A FEW HOURS BEFORE SUNRISE AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO A WEDGE OF HIGH PRESSURE BUILDING SOUTH THROUGH THE CAROLINA PIEDMONT. THE RISK FOR DRIZZLE IN THE WAKE OF THE FRONT LOOKS MINIMAL AT THIS POINT WITH RAP AND NAM12 POINT SOUNDINGS SHOWING PLENTY OF MID-LEVEL DRY AIR. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... WHILE THERE ARE VARIATIONS BETWEEN MODELS ON LOCATION AND INTENSITY...GENERAL CONSENSUS IS THAT A SURFACE HIGH PRESSURE WEDGE WILL ESTABLISH ITSELF OVER THE FORECAST AREA WEDNESDAY AND PERSIST THROUGH LATE WEEK. THIS IS THE EASY PART OF THIS FORECAST PERIOD. AN ACTIVE WEATHER PATTERN LOOKS TO DEVELOP TO THE SOUTH AND WEST OF THE FORECAST AREA...AFFECTING PRIMARILY THE GULF STATES...BUT ADDITIONAL UNCERTAINTIES IN THE NATURE OF THIS ZONE AND ITS DEVELOPMENT WILL TRANSLATE INTO FORECAST UNCERTAINTY FOR THE PERIOD THROUGH FRIDAY. MODEL GUIDANCE SUGGESTS THAT PERIODS OF PRECIPITATION ARE LIKELY THROUGH AT LEAST FRIDAY BUT POSSIBILITIES RANGE FROM MOSTLY RAIN-FREE CONDITIONS HEADING INTO THE WEEKEND TO MUCH WETTER CONDITIONS THAN THE FORECAST PAINTS DEPENDING ON HOW MUCH INFLUENCE THIS REGION OF ACTIVE WEATHER EXERTS ON OUR FORECAST AREA. GEORGIA ZONES ARE MOST LIKELY TO SEE DETERIORATING CONDITIONS CONSIDERING THE PROXIMITY TO THE ZONE AND PROGNOSED HIGHER PRECIPITABLE WATER VALUES OF AN INCH OR GREATER COMPARED TO PWATS GENERALLY LESS THAN AN INCH ACROSS SOUTH CAROLINA ZONES. ADDITIONALLY...A NOSE OF COMPARATIVELY DRIER AIR MAY SUCCEED IN INFILTRATING SOUTH CAROLINA ZONES...ASSISTING IN LIMITING PRECIPITATION POTENTIAL TO THE NORTH. REGARDLESS...EXTENSIVE CLOUD COVER IS ANTICIPATED ACROSS THE FORECAST AREA AND THIS COMBINED WITH PERSISTENT NORTHEAST WINDS WILL CONTRIBUTE TO LOWER THAN NORMAL MAXIMUM TEMPERATURES...GENERALLY IN THE 60S...THROUGH THE PERIOD. WINDS MAY BE STRONGER/GUSTY AT TIMES...PARTICULARLY NEAREST THE COAST...WHICH MAY NECESSITATE WIND ADVISORIES FOR COASTAL COUNTIES. AN UPPER LEVEL LOW COULD APPROACH THE REGION FROM THE WEST ON FRIDAY...BRINGING WITH IT ADDITIONAL FORCING FOR PRECIPITATION PRODUCTION. CONSIDERING THESE FACTORS...THE LATEST FORECAST CONTINUES THE TREND OF SHOWING POPS PROGRESSIVELY HIGHER FROM NORTH TO SOUTH AND INCREASING TOWARDS FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THIS WEEKEND...DEEP LAYERED RIDGING SHOULD BEGIN TO EXPAND OVER THE EASTERN CONUS...PUSHING AN UPPER LOW/TROUGH AND ACTIVE BAROCLINIC ZONE SOUTH/EAST OF THE REGION...TRANSLATING TO A WARMING/DRYING TREND. THE PACE OF THIS DRYING/WARMING TREND REMAINS SOMEWHAT UNCLEAR AND COULD REMAIN SLOW THIS WEEKEND...BUT ANY CHANCE FOR SHOWERS SHOULD END BY LATE WEEKEND AND TEMPERATURES SHOULD WARM INTO THE 70S/LOWER 80F BY EARLY NEXT WEEK. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... MAINLY VFR CONDITIONS WILL PERSIST INTO THE EVENING...THOUGH MVFR CONDITIONS ARE POSSIBLE AT BOTH TERMINALS WITH EXPECTED SHOWERS AND THUNDERSTORMS THIS AFTERNOON. ANY THUNDERSTORMS SHOULD REMAIN PRETTY WEAK GIVEN THE LIMITED INSTABILITY. CONDITIONS WILL DETERIORATE TO IFR LATE TONIGHT AND TOMORROW MORNING AS THE SHALLOW COLD FRONT MOVES THROUGH AND COLD AIR DAMMING BUILDS A WEDGE OF HIGH PRESSURE ACROSS THE AREA THROUGH THE EARLY MORNING HOURS. THE EXACT TIMING OF THE IFR CEILINGS DEVELOPING IS STILL A BIT UNCERTAIN...BUT HI-RES MODELS ARE CONSISTENTLY BRINGING SUB-1KFT CEILINGS DURING THIS TIME. CONDITIONS MAY IMPROVE A BIT AFTER SUNRISE...BUT MVFR CEILINGS ARE STILL EXPECTED DURING THE DAY WEDNESDAY WITH BREEZY NORTH WINDS. EXTENDED AVIATION OUTLOOK...PERIODS OF FLIGHT RESTRICTIONS...MAINLY IN LOWER CEILINGS...ARE POSSIBLE THROUGH THE PERIOD DUE TO MOISTURE TRAPPED BENEATH A WEDGE OF HIGH PRESSURE/SUBSIDENCE INVERSION. && .MARINE... TONIGHT...SOUTHERLY WINDS WILL GRADUALLY WEAKEN THIS EVENING AS THE PRESSURE GRADIENT RELAXES AHEAD OF A BACKDOOR COLD FRONT. NORTH TO NORTHEAST WINDS WILL RAMP UP QUICKLY PRIOR TO DAYBREAK WITH SPEEDS REACHING AS HIGH AS 15-20 KT WITH GUSTS TO 25 KT ACROSS CHARLESTON COUNTY WATERS, INCLUDING CHARLESTON HARBOR WITH 10-15 KT WITH GUSTS TO 20 KT ELSEWHERE. SEAS WILL BUILD IN THE STRENGTHENING NORTH/NORTHEAST FETCH REACHING AS HIGH AS 2-4 FT CHARLESTON COUNTY WATERS AND 1-3 FT ELSEWHERE. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE CHARLESTON COUNTY WATERS AND CHARLESTON HARBOR BEGINNING EARLY TUESDAY. THE WORSE MARINE CONDITIONS WILL CERTAINLY HOLD OFF UNTIL AFTER SUNRISE. WEDNESDAY THROUGH SUNDAY...THE COLD FRONT WILL EXIT THE WATERS LATE TUESDAY OR EARLY WEDNESDAY...LEAVING THE COASTAL WATERS UNDER THE INFLUENCE OF A STRONG PRESSURE GRADIENT LOCATED BETWEEN THE HIGH PRESSURE WEDGE INLAND AND LOWER PRESSURE OFFSHORE...USHERING IN A PROLONGED PERIOD OF STRONG NORTHEAST WINDS AND HIGH CONFIDENCE IN DEVELOPMENT OF SMALL CRAFT ADVISORY CONDITIONS. GALES ARE ALSO POSSIBLE LATER THIS WEEK...ESPECIALLY IN AMZ374. AT THIS TIME...THE MOST PROBABLE TIMEFRAME APPEARS TO BE ROUGHLY 14-16Z FRIDAY...ALTHOUGH UNCERTAINTY REMAINS HIGH. SMALL CRAFT ADVISORIES REMAIN IN EFFECT FOR CHARLESTON HARBOR AND AMZ350 BEGINNING 9-10Z WEDNESDAY...AND EXTEND TO WATERS SOUTH OF EDISTO BEACH DURING THE 12-15Z WEDNESDAY TIME FRAME. DETERMINING APPROPRIATE END TIMES FOR THE SMALL CRAFT ADVISORIES REMAINS DIFFICULT AT THIS JUNCTURE DUE TO FORECAST UNCERTAINTY INHERENT WITH THIS WEDGE-TYPE PATTERN. FOR NOW...THE SMALL CRAFT ADVISORY FOR CHARLESTON HARBOR EXPIRES AT THE END OF THE DAY FRIDAY AND FOR OTHER NEARSHORE WATERS SATURDAY MORNING. THE SMALL CRAFT ADVISORY FOR AMZ374 REMAINS IN EFFECT THROUGH SUNDAY SINCE LINGERING ELEVATED SEA CONDITIONS WOULD REMAIN EVEN IF WINDS SUBSIDED BELOW ADVISORY THRESHOLDS. RIP CURRENTS...MODERATE RISK FOR RIP CURRENTS WEDNESDAY AND AN ELEVATED RISK OF RIP CURRENTS IS PROBABLE INTO THE WEEKEND DUE TO A PROLONGED PERIOD OF STRONG NORTHEAST WINDS. && .TIDES/COASTAL FLOODING... STRONG AND PERSISTENT NORTHEAST WINDS WILL CONTRIBUTE TO ELEVATED TIDES AND INCREASED PROBABILITIES OF BEACH EROSION WEDNESDAY INTO THE WEEKEND. DESPITE THIS...HIGH TIDE LEVELS ARE EXPECTED TO REMAIN BELOW COASTAL FLOOD ADVISORY THRESHOLDS...THOUGH THE EXTENDED NATURE OF THIS EVENT NECESSITATES CONTINUAL MONITORING OF TIDE TRENDS THROUGH THE PERIOD. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 8 PM EDT FRIDAY FOR AMZ330. SMALL CRAFT ADVISORY FROM 8 AM WEDNESDAY TO 8 AM EDT SATURDAY FOR AMZ352. SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO 8 AM EDT SATURDAY FOR AMZ350. SMALL CRAFT ADVISORY FROM 11 AM WEDNESDAY TO 3 AM EDT SUNDAY FOR AMZ374. SMALL CRAFT ADVISORY FROM 11 AM WEDNESDAY TO 8 AM EDT SATURDAY FOR AMZ354. && $$ ST/CEB/JMC
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
947 AM EDT TUE APR 12 2016 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. A WEDGE OF HIGH PRESSURE WILL THEN BUILD INTO THE REGION FROM THE NORTH AND WILL PREVAIL INTO THE WEEKEND. THE CENTER OF THE HIGH WILL SHIFT SOUTH TOWARD THE REGION EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE INITIAL PUSH OF LIGHT RAIN HAS CLEARED THE COAST. THERE LOOKS TO BE SEVERAL HOURS OF MAINLY DRY CONDITIONS OUTSIDE OF AN ISOLATED, LIGHT SHOWER BEFORE ADDITIONAL SHOWERS REDEVELOP LATER THIS AFTERNOON. THE NEXT BATCH OF RAIN IS EXPECTED TO DEVELOP BY EARLY AFTERNOON OVER THE SOUTH CAROLINA MIDLANDS INTO CENTRAL GEORGIA AS UPPER FORCING ASSOCIATED WITH THE LEFT EXIT REGION OF THE 250 HPA JET PROPAGATES IN FROM THE WEST. THIS ACTIVITY IS TIMED TO MOVE INTO THE FAR WESTERN ZONES BY EARLY/MID AFTERNOON AND REACHING THE COAST BY LATE AFTERNOON. THERE IS SOME UNCERTAINTY ON EXACTLY HOW MUCH SHOWER ACTIVITY WILL REDEVELOP AS MUCH OF THIS WILL DEPEND ON HOW MUCH INSTABILITY CAN FORM AS BREAKS IN THE CLOUD CANOPY MEANDER THROUGH THE AREA. POPS WILL BE CAPPED AT 60-70 PERCENT UNTIL TRENDS BECOME A BIT MORE APPARENT ON WHERE ACTIVITY WILL CONCENTRATE. THE LATEST H3R, NSSL-WRF AND RAP ALL INDICATE THE GREATER COVERAGE WILL OCCUR ACROSS SOUTHEAST GEORGIA, WHICH SEEMS REASONABLE AS THE GREATEST AMOUNT OF CLEARING SHOULD OCCUR IN THIS AREA BASED ON GOES-E VISIBLE AND MODEL DERIVED SATELLITE DATA. HIGHS STILL LOOK TO BE ABLE TO RECOVER INTO THE LOWER 70S WELL INLAND TO THE UPPER 70S IN THE DARIEN-LUDOWICI- SAVANNAH CORRIDOR. THE OVERALL SEVERE WEATHER RISK IS ASSESSED TO BE LOW GIVEN MEAGER INSTABILITY PROFILES, DESPITE THE PRESENCE OF 40 KT OF 0-6KM BULK SHEAR. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... TONIGHT...THE COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA THIS EVENING BRINGING AN END TO THE HEAVIER SHOWERS/THUNDERSTORMS. HOWEVER...LINGERING LOW-LEVEL MOISTURE WILL YIELD PLENTY OF LOW CLOUDS AND POSSIBLY EVEN SOME DRIZZLE. LOWS WILL RANGE FROM THE LOWER 50S NORTHWEST TO NEAR 60 SOUTHEAST. WINDS WILL PICK UP FROM THE NORTH AND NORTHEAST AFTER THE FRONT PASSES THROUGH...LIKELY GUSTING OVER 20 MPH NEAR THE CHARLESTON METRO LATE...ESPECIALLY ALONG THE COAST. WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS HIGH THAT A WEDGE OF HIGH PRESSURE WILL SURGE INTO THE FORECAST AREA WEDNESDAY AND WILL PREVAIL THROUGH LATE WEEK. STRONG NORTHEAST FLOW AND CLOUD COVER WILL HOLD TEMPERATURES BELOW NORMAL. TEMPERATURES COULD RECOVER INTO THE LOWER 70S ALONG/SOUTH OF INTERSTATE 16 WEDNESDAY...OTHERWISE HIGHS IN THE 60S WILL REMAIN COMMON THROUGH LATE WEEK. LOW TEMPS WILL RANGE FROM THE UPPER 40S FAR NORTH TO THE LOWER/MID 50S MOST OTHER AREAS...HIGHEST ALONG THE COAST AND FAR SOUTH. THIS PERIOD STILL INCLUDES A HIGH DEGREE OF UNCERTAINTY REGARDING THE CHANCE FOR SHOWERS DUE TO A COMPLEX/BLOCKED UPPER PATTERN AND AN ACTIVE BAROCLINIC ZONE EXTENDING FROM THE LOWER GULF COAST REGION INTO NORTH FLORIDA AND SOUTH GEORGIA. AN UPPER LOW AND/OR UPPER TROUGH AND ASSOCIATED POOL OF VORTICITY ALOFT WILL BECOME TRAPPED OVER THE SOUTHEAST AND WILL INTERACT WITH THE BAROCLINIC ZONE... SUPPORTING MULTIPLE ROUNDS OF PRECIPITATION INCLUDING THE POTENTIAL FOR SEVERAL CONVECTIVE COMPLEXES TO TRAVERSE THE DEEP SOUTH. PRIMARY QUESTIONS INCLUDE WHETHER FORCING FOR ASCENT WILL SUPPORT AN EXPANSION OF SHOWERS INTO THE FORECAST AREA...AND IF SO HOW FAR NORTH WILL DEEP LAYERED MOISTURE EXPAND INTO OUR AREA. FURTHER... UNCERTAINTY IS HEIGHTENED BY THE POTENTIAL FOR ORGANIZED CONVECTION AND MOST PRECIPITATION TO REMAIN WITHIN THE BAROCLINIC SOUTH OF THE REGION. THE LATEST FORECAST REPRESENTS AN ATTEMPT TO SYNTHESIZE VARYING 12/00 UTC SOLUTIONS WITHOUT INTRODUCING MAJOR FORECAST CHANGES. IN GENERAL...POPS ARE GRADUATED FROM HIGHEST SOUTH TO LOWEST NORTH THROUGH THIS PERIOD. SPECIFICALLY...LIMITED SLIGHT CHANCE POPS TO FAR SOUTHERN ZONES WEDNESDAY TO ACCOUNT FOR THE INITIAL SURGE OF DRIER AIR INTO THE REGION. WEDNESDAY NIGHT AND THURSDAY...EXPANDED COVERAGE OF SHOWERS SOMEWHAT BUT MAINTAINED POPS BELOW 15 PERCENT WITH NO MENTION OF PRECIPITATION FAR NORTH ACCOMPANIED BY SLIGHT CHANCE POPS ELSEWHERE. THURSDAY NIGHT AND FRIDAY...POPS RANGE FROM SLIGHT CHANCE NORTH TO CHANCE SOUTH. IN A WORST CASE SCENARIO...A POOL OF MOISTURE WILL REMAIN OVER THE FORECAST AREA AND THIS PERIOD COULD BECOME MUCH WETTER THAN CURRENTLY FORECAST. IN A BEST CASE SCENARIO...MOST/ALL RAIN COULD REMAIN SOUTH OF THE REGION. SIGNIFICANT FORECAST CHANGES COULD BE FORTHCOMING OVER THE NEXT COUPLE OF DAYS. ALSO OF NOTE...GUSTY NORTHEAST WINDS WILL PERSIST ALONG THE COAST THROUGH AT LEAST THE END OF THIS WEEK. WIND ADVISORIES CANNOT BE DISCOUNTED FOR COASTAL COUNTIES. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THIS WEEKEND...DEEP LAYERED RIDGING SHOULD BEGIN TO EXPAND OVER THE EASTERN CONUS...PUSHING AN UPPER LOW/TROUGH AND ACTIVE BAROCLINIC ZONE SOUTH/EAST OF THE REGION...TRANSLATING TO A WARMING/DRYING TREND. THE PACE OF THIS DRYING/WARMING TREND REMAINS SOMEWHAT UNCLEAR AND COULD REMAIN SLOW THIS WEEKEND...BUT ANY CHANCE FOR SHOWERS SHOULD END BY LATE WEEKEND AND TEMPERATURES SHOULD WARM INTO THE 70S/LOWER 80F BY EARLY NEXT WEEK. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VFR CONDITIONS ARE EXPECTED TO PREVAIL AT BOTH TERMINALS THIS MORNING BEFORE THE RISK FOR MVFR CIGS INCREASES AS A COLD FRONT APPROACHES FROM THE WEST. SOME SHOWERS WILL MOVE THROUGH THIS MORNING BUT THEY ARE GENERALLY LIGHT AND UPSTREAM OBS INDICATE VFR CIGS SO WE KEPT IT VFR FOR NOW. RAIN CHANCES WILL INCREASE THIS AFTERNOON AS SHOWERS AND A FEW THUNDERSTORMS MOVE THROUGH AHEAD OF AN APPROACHING COLD FRONT. ANY THUNDERSTORMS SHOULD REMAIN PRETTY WEAK GIVEN THE LIMITED INSTABILITY. RAIN CHANCES WILL DIMINISH IN THE EVENING AS THE COLD FRONT MOVES THROUGH BUT SOME DRIZZLE COULD LINGER AND CIGS WILL LOWER...POSSIBLY DOWN TO LIFR LEVELS. SOUTH/SOUTHWEST WINDS WILL VEER WEST TOWARD EVENING AND THEN NORTHEAST TOWARD THE END OF THE PERIOD. GUSTS 20-25 KT ARE LIKELY AFTER THE FRONTAL PASSAGE. EXTENDED AVIATION OUTLOOK...PERIODS OF FLIGHT RESTRICTIONS...MAINLY IN LOWER CEILINGS...ARE POSSIBLE THROUGH THE PERIOD DUE TO MOISTURE TRAPPED BENEATH A WEDGE OF HIGH PRESSURE/SUBSIDENCE INVERSION. && .MARINE... TODAY AND TONIGHT...SOUTH TO SOUTHWEST WINDS WILL PREVAIL 15 KT OR LESS TODAY AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. THE FRONT IS SLATED TO MOVE NORTH TO SOUTH THROUGH THE AREA STARTING THIS EVENING...WITH WINDS BECOMING NORTH AND THEN NORTHEAST AND INCREASING AFTERWARD. SHOULD SEE GUSTS REACH ADVISORY LEVELS /25 KT/ OVER THE CHARLESTON COUNTY WATERS LATE. AS A COLD FRONT PUSHES SOUTH OF THE WATERS WEDNESDAY...NORTHEAST WINDS WILL SURGE INTO THE COASTAL WATERS AND WILL BEGIN AN EXTENDED PERIOD OF SOLID SMALL CRAFT ADVISORY CONDITIONS AS THE REGION REMAINS LOCKED IN A WELL-MIXED/TIGHT SURFACE PRESSURE GRADIENT REGIME BETWEEN STRONG HIGH PRESSURE TO THE NORTH AND OFFSHORE LOW PRESSURE. DUE TO HIGH FORECAST CONFIDENCE...WE RAISED SMALL CRAFT ADVISORIES FOR CHARLESTON HARBOR AND FOR AMZ350 STARTING AT 5 AM WEDNESDAY...AND STARTED SMALL CRAFT ADVISORIES FOR WATERS SOUTH OF EDISTO BEACH DURING THE 12-15Z WEDNESDAY TIME FRAME. GALES COULD EVEN DEVELOP LATER THIS WEEK IN SOME AREAS...ESPECIALLY ACROSS AMZ374. FORECAST UNCERTAINTY ARISES REGARDING THE END TIMES OF SMALL CRAFT ADVISORY CONDITIONS. FOR NOW...ENDED THE SMALL CRAFT ADVISORY FOR CHARLESTON HARBOR AT THE END OF THE DAY FRIDAY AND FOR OTHER NEARSHORE WATERS SATURDAY MORNING. ACROSS AMZ374...EVEN IF WINDS RELAX THIS WEEKEND SEAS WILL EASILY EXCEED 6 FT THROUGH SUNDAY...SO THE SCA FOR THE OUTER GA WATERS CONTINUES THROUGH SUNDAY/THE END OF THIS FORECAST PERIOD. RIP CURRENTS...STRONG...PERSISTENT NORTHEAST WINDS WILL PRODUCE ROUGH CONDITIONS IN THE SURF ZONE AND WILL LIKELY CONTRIBUTE TO AN ELEVATED RISK OF RIP CURRENTS WEDNESDAY INTO THE WEEKEND. && .TIDES/COASTAL FLOODING... PERSISTENT/STRONG NORTHEAST WINDS WILL CREATE ELEVATED TIDES AND SURF WHICH COULD PRODUCE BEACH EROSION WEDNESDAY INTO THE WEEKEND. HIGH TIDES ARE EXPECTED TO REMAIN BELOW SHALLOW COASTAL FLOOD THRESHOLDS...BUT THIS COULD CHANGE DUE TO THE EXTENDED NATURE OF THIS EVENT. WE WILL CONTINUE TO ASSESS TRENDS. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 8 PM EDT FRIDAY FOR AMZ330. SMALL CRAFT ADVISORY FROM 8 AM WEDNESDAY TO 8 AM EDT SATURDAY FOR AMZ352. SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO 8 AM EDT SATURDAY FOR AMZ350. SMALL CRAFT ADVISORY FROM 11 AM WEDNESDAY TO 3 AM EDT SUNDAY FOR AMZ374. SMALL CRAFT ADVISORY FROM 11 AM WEDNESDAY TO 8 AM EDT SATURDAY FOR AMZ354. && $$ ST
AREA FORECAST DISCUSSION...UPDATED
NWS POCATELLO ID
852 AM MDT TUE APR 12 2016 .UPDATE...NO MAJOR UPDATES FOR THIS MORNING. WE DID TWEAK GRIDS HERE AND THERE...MAINLY TO INCREASE SHOWER/THUNDERSTORM COVERAGE A BIT ACROSS THE SNAKE PLAIN FROM POCATELLO TO INL AND BACK TO THE WEST. WE ALSO DECREASED COVERAGE ACROSS THE IDAHO WASATCH AND THE BEAR LAKE AREA. LOCALLY HEAVY RAINFALL AND SMALL HAIL ARE THE MAIN ISSUES WITH STORMS THAT WE WILL SEE TODAY. KEYES && .PREV DISCUSSION... /ISSUED 143 AM MDT TUE APR 12 2016/ SHORT TERM...TODAY THROUGH THURSDAY NIGHT. SPLIT FLOW OVER THE WEST THIS MORNING SEEN ON WV IMAGERY. CLOSED UPPER LOW CONTINUES TO SPIN MOISTURE UP INTO THE FOUR-CORNERS AREA WHILE THE NORTHERN BRANCH IS MORE UNDER THE INFLUENCE OF A BROAD UPPER RIDGE. A TROUGH IS BEGINNING TO MAKE LANDFALL INTO OR/WA AND IS EXPECTED TO TRIGGER SHOWERS AND THUNDERSTORMS ACROSS IDAHO THIS AFTERNOON AND EVENING. HRRR BEGINS CONVECTION AROUND 19Z ACROSS THE REGION. NAM/GFS KEEP ACTIVITY MORE CONFINED TO THE MOUNTAINS. SNOW LEVELS REMAIN AROUND 9500-10000 FT SO ALL BUT THE HIGHEST PEAKS SHOULD SEE RAIN. SNOW LEVELS GRADUALLY LOWER TO 7500-8000 FT BY WEDNESDAY NIGHT AS AN UPPER LOW IS DRIVEN ONSHORE. AFTERNOON/EVENING THUNDERSTORMS ARE EXPECTED AGAIN TOMORROW. GFS/NAM AT ODDS WITH TRAJECTORY OF UPPER LOW. GFS DRIVES LOW INTO GREAT BASIN BY FRIDAY MORNING WHILE THE NAM PUTS IT RIGHT OVER EAST IDAHO. MADE ONLY MINOR TWEAKS DURING THE LATTER HALF OF THE WEEK. EXPECT CONTINUED UNSETTLED WEATHER AND COOLING TEMPERATURES THROUGH THURSDAY NIGHT. HINSBERGER LONG TERM...FRIDAY THROUGH NEXT TUESDAY. THE GFS AND ECMWF SHOW DIFFERING SOLUTIONS THAT DEPICT CONSIDERABLE VARIATION ON THE TRACK AND EVOLUTION OF THE INCOMING LOW THURSDAY/FRIDAY. THE GFS APPEARS TO DIG THE LOW SE THROUGH OREGON AND INTO NRN ARIZONA BY FRIDAY AFTERNOON WHEREAS THE ECMWF DRIVES THE LOW EAST INTO NRN IDAHO THURSDAY WHILE SECONDARY FOLLOW-ON ENERGY CARVES OUT A SECOND CIRCULATION OVER NRN ARIZONA WITH THE PRIMARY LOW OVER CNTRL MONTANA. BY SATURDAY...THE ECMWF DRIVES THE ARIZONA LOW CENTER INTO NE NEW MEXICO AS A RIDGE BUILDS ACROSS THE NW STATES WHILE THE GFS SHOWS THE LOW CAMPED OUT OVER THE 4-CORNERS REGION WITH WRAP-AROUND MOISTURE STILL IMPACTING THE ERN HIGHLANDS. BOTH MODELS EVENTUALLY LIFT THE LOW NORTHWARD...THE GFS A BIT FURTHER WEST OVER THE ROCKIES WHILE THE ECMWF HAS THE MAIN EVENT EAST OF THE ROCKIES...THE RESULTING SOLUTIONS EITHER SPELL SHOWERS OVER THE ERN HIGHLANDS OR DRY AND WARMING CONDITIONS. THE DIFFERENCES DO NOT STOP THERE...BY MONDAY AFTERNOON INTO TUESDAY...BOTH MODELS SEND A PAC TROUGH EWRD OVER THE RIDGE BUT WITH THE GFS SOLUTION IT IS MUCH FURTHER SOUTH OVER IDAHO WITH ATTENDING WIND AND SHOWERS WHEREAS THE ECMWF TAKES THE WAVE EAST THROUGH CANADA LEAVING SE IDAHO DRY AND WARM. WILL SPLIT THE DIFFERENCE WITH MOST OF THIS UNTIL THE MODELS FIND A COMMON SOLUTION. HUSTON AVIATION...CLEARING SKIES WERE NOTED ACROSS THE REGION EARLY THIS MORNING. LOOKING UPSTREAM...A TROUGH WAS ADVANCING TOWARD THE COAST AND NUMERICAL MODELS DRIVE AN ASSOCIATED FRONTAL BOUNDARY INTO THE PANHANDLE AND CNTRL MOUNTAINS THIS AFTERNOON FORCING CONVECTION IN THAT REGION WHILE RESIDUAL MOISTURE AND INSTABILITY COUPLED WITH A PASSING VORT FEATURE TRIGGER AFTERNOON THUNDERSTORMS OVER THE SRN MOUNTAINS. VCTY TSTMS ARE A GIVEN AT ALL TERMINAL SITES THIS AFTERNOON/EVE WITH VFR BKN CIGS. MIGHT SEE MVFR CIGS IN SHOWERS IF A CELL MOVES DIRECTLY OVER A TERMINAL AND WE WILL ALLOW LATER SHIFTS TO ADJUST ACCORDINGLY. MODEL TIME-SECTIONS ARE SHOWING LOWERING CIGS LATE TONIGHT AS THE MAIN FRONTAL BOUNDARY SAGS SOUTH INTO THE SNAKE RIVER PLAIN ENHANCING PRECIPITATION PRODUCTION ACROSS THE SE HIGHLANDS AND SNAKE RIVER PLAIN. HUSTON && .PIH WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
143 AM MDT TUE APR 12 2016 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT. SPLIT FLOW OVER THE WEST THIS MORNING SEEN ON WV IMAGERY. CLOSED UPPER LOW CONTINUES TO SPIN MOISTURE UP INTO THE FOUR-CORNERS AREA WHILE THE NORTHERN BRANCH IS MORE UNDER THE INFLUENCE OF A BROAD UPPER RIDGE. A TROUGH IS BEGINNING TO MAKE LANDFALL INTO OR/WA AND IS EXPECTED TO TRIGGER SHOWERS AND THUNDERSTORMS ACROSS IDAHO THIS AFTERNOON AND EVENING. HRRR BEGINS CONVECTION AROUND 19Z ACROSS THE REGION. NAM/GFS KEEP ACTIVITY MORE CONFINED TO THE MOUNTAINS. SNOW LEVELS REMAIN AROUND 9500-10000 FT SO ALL BUT THE HIGHEST PEAKS SHOULD SEE RAIN. SNOW LEVELS GRADUALLY LOWER TO 7500-8000 FT BY WEDNESDAY NIGHT AS AN UPPER LOW IS DRIVEN ONSHORE. AFTERNOON/EVENING THUNDERSTORMS ARE EXPECTED AGAIN TOMORROW. GFS/NAM AT ODDS WITH TRAJECTORY OF UPPER LOW. GFS DRIVES LOW INTO GREAT BASIN BY FRIDAY MORNING WHILE THE NAM PUTS IT RIGHT OVER EAST IDAHO. MADE ONLY MINOR TWEAKS DURING THE LATTER HALF OF THE WEEK. EXPECT CONTINUED UNSETTLED WEATHER AND COOLING TEMPERATURES THROUGH THURSDAY NIGHT. HINSBERGER .LONG TERM...FRIDAY THROUGH NEXT TUESDAY. THE GFS AND ECMWF SHOW DIFFERING SOLUTIONS THAT DEPICT CONSIDERABLE VARIATION ON THE TRACK AND EVOLUTION OF THE INCOMING LOW THURSDAY/FRIDAY. THE GFS APPEARS TO DIG THE LOW SE THROUGH OREGON AND INTO NRN ARIZONA BY FRIDAY AFTERNOON WHEREAS THE ECMWF DRIVES THE LOW EAST INTO NRN IDAHO THURSDAY WHILE SECONDARY FOLLOW-ON ENERGY CARVES OUT A SECOND CIRCULATION OVER NRN ARIZONA WITH THE PRIMARY LOW OVER CNTRL MONTANA. BY SATURDAY...THE ECMWF DRIVES THE ARIZONA LOW CENTER INTO NE NEW MEXICO AS A RIDGE BUILDS ACROSS THE NW STATES WHILE THE GFS SHOWS THE LOW CAMPED OUT OVER THE 4-CORNERS REGION WITH WRAP-AROUND MOISTURE STILL IMPACTING THE ERN HIGHLANDS. BOTH MODELS EVENTUALLY LIFT THE LOW NORTHWARD...THE GFS A BIT FURTHER WEST OVER THE ROCKIES WHILE THE ECMWF HAS THE MAIN EVENT EAST OF THE ROCKIES...THE RESULTING SOLUTIONS EITHER SPELL SHOWERS OVER THE ERN HIGHLANDS OR DRY AND WARMING CONDITIONS. THE DIFFERENCES DO NOT STOP THERE...BY MONDAY AFTERNOON INTO TUESDAY...BOTH MODELS SEND A PAC TROUGH EWRD OVER THE RIDGE BUT WITH THE GFS SOLUTION IT IS MUCH FURTHER SOUTH OVER IDAHO WITH ATTENDING WIND AND SHOWERS WHEREAS THE ECMWF TAKES THE WAVE EAST THROUGH CANADA LEAVING SE IDAHO DRY AND WARM. WILL SPLIT THE DIFFERENCE WITH MOST OF THIS UNTIL THE MODELS FIND A COMMON SOLUTION. HUSTON && .AVIATION...CLEARING SKIES WERE NOTED ACROSS THE REGION EARLY THIS MORNING. LOOKING UPSTREAM...A TROUGH WAS ADVANCING TOWARD THE COAST AND NUMERICAL MODELS DRIVE AN ASSOCIATED FRONTAL BOUNDARY INTO THE PANHANDLE AND CNTRL MOUNTAINS THIS AFTERNOON FORCING CONVECTION IN THAT REGION WHILE RESIDUAL MOISTURE AND INSTABILITY COUPLED WITH A PASSING VORT FEATURE TRIGGER AFTERNOON THUNDERSTORMS OVER THE SRN MOUNTAINS. VCTY TSTMS ARE A GIVEN AT ALL TERMINAL SITES THIS AFTERNOON/EVE WITH VFR BKN CIGS. MIGHT SEE MVFR CIGS IN SHOWERS IF A CELL MOVES DIRECTLY OVER A TERMINAL AND WE WILL ALLOW LATER SHIFTS TO ADJUST ACCORDINGLY. MODEL TIME-SECTIONS ARE SHOWING LOWERING CIGS LATE TONIGHT AS THE MAIN FRONTAL BOUNDARY SAGS SOUTH INTO THE SNAKE RIVER PLAIN ENHANCING PRECIPITATION PRODUCTION ACROSS THE SE HIGHLANDS AND SNAKE RIVER PLAIN. HUSTON && .PIH WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1111 AM MDT TUE APR 12 2016 .UPDATE... ISSUED AT 925 AM MDT TUE APR 12 2016 UPDATE ISSUED TO REMOVE MENTION OF PATCHY FOG. FULL SUNSHINE OVER THE CWA ALONG WITH INCREASED SW WINDS THIS MORNING HAS ALLOWED MORNING FOG OVER SW ZONES TO DISSIPATE. SOME TWEAKS MADE TO TEMPS FROM LATEST HOURLY TREND...OTHERWISE FORECAST IS ON TRACK. && .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 325 AM MDT TUE APR 12 2016 MAIN FORECAST ISSUES WILL BE PRECIPITATION CHANCES THROUGH THURSDAY NIGHT...AND WINDS THURSDAY/THURSDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED FLOW...ALTHOUGH NOT AS MUCH OVER THE PACIFIC FROM YESTERDAY...FROM THE PACIFIC INTO EASTERN NORTH AMERICA. SPLIT FLOW IS IN PLACE OVER THE WESTERN PORTION OF THE COUNTRY WITH A CLOSED OFF LOW OVER THE DESERT SOUTHWEST. AT JET LEVEL...STARTED OUT FINE. AT MID LEVELS...MAIN ISSUE HERE WAS THE MODELS WERE NOT QUITE STRONG ENOUGH WITH THE WESTERN RIDGE. THE GFS AND CANADIAN WERE DOING THE BEST. THE NAM AND ECMWF WERE DOING THE BEST ON THE SURFACE WIND/PRESSURE FIELD. NAM WAS DOING A LITTLE BETTER THAN THE REMAINING OUTPUT ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...SOME FOG AND STRATUS OVER OR MOVING TOWARD THE WESTERN PORTION OF THE AREA AT THIS TIME. MOST HIGH RESOLUTION GUIDANCE CAPTURING THIS NICELY AND MADE ADJUSTMENTS TO THIS MORNINGS FOG FORECAST. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS SUPPORT BREEZY TO WINDY CONDITIONS OVER MOST OF THE AREA AND WILL CONTINUE THAT IN THE GRIDS. WEAK SHORTWAVE MOVES TROUGH LATE THIS AFTERNOON INTO THE EARLY EVENING WITH THE SURFACE CONVERGENCE TO THE WEST. LOW LEVEL MOISTURE IS LACKING. A FEW MODELS ARE SHOWING LIGHT QPF VERY NEAR THE NORTHWEST PORTION OF THE AREA LATE THIS AFTERNOON INTO THIS EVENING. HOWEVER MOST OF THE HIGH RESOLUTION GUIDANCE KEEPS IT TO THE WEST OF OUR AREA. THE STEERING FLOW IS LIGHT SO IF SOMETHING WOULD FORM IT WILL NOT MOVE FAR. SO RIGHT NOW AM GOING TO KEEP THIS PERIOD DRY. RECENT TRENDS IN GUIDANCE HAVE BEEN TO BE TOO COOL WITH THE MAXES. NEWER GUIDANCE SUPPORTS NUDGING UP THE HIGH TEMPERATURES AND DID SO. LIGHT WINDS ESPECIALLY IN THE WEST LATE TONIGHT WILL TEMPERATURES TO COOL TO BELOW GUIDANCE. LOOKS TO BE SOME SHALLOW MOISTURE BROUGHT UP IN ADVANCE OF THE TROUGH OVER THE WESTERN PORTION OF THE AREA...AND THERE COULD BE SOME LIGHT FOG POSSIBLE. WEDNESDAY/WEDNESDAY NIGHT...WHATEVER LIGHT FOG THERE IS WILL BURN OFF QUICKLY. MODELS ARE PRODUCING A VERY LIGHT QPF SIGNAL IN THE FAR WEST LATE IN THE AFTERNOON INTO THE EARLY EVENING. MAIN AREA OF SURFACE CONVERGENCE REMAINS TO THE WEST THROUGH THE PERIOD. A WEAK SHORTWAVE MOVES THROUGH EARLY WITH A STRONGER ONE APPROACHING LATE. FOR THE LATE AFTERNOON INTO THE EVENING...THE STEERING FLOW IS LIGHT TO NON-EXISTENT. IT DOES LOOK A LIKE A WARM AIR ADVECTION PATTERN SETTING UP LATER IN THE NIGHT. NAM SHOWS INSTABILITY AND THE GFS DOES NOT. NAM MAYBE OVERDOING THE MOISTURE. ALTHOUGH THE WARM AIR ADVECTION AND SHORTWAVE ALOFT HAS ME CONCERNED. BASED ON ABOVE REASONING AND COLLABORATION WITH WFO BOU...AM GOING TO KEEP IT DRY. MODELS SHOWING SOME STRATUS AND MAYBE SOME FOG BEING PULLED INTO THE AREA LATE IN THE NIGHT. BASED ON THAT AND COLLABORATION...INCREASED CLOUD COVER AND ADDED SOME PATCHY FOG. THURSDAY/THURSDAY NIGHT...AM A LITTLE CONCERNED THAT THE MORNING STRATUS AND MAYBE SOME FOG WILL PLAGUE THE AREA AND MAY HAVE A SIGNIFICANT AFFECT ON THE TEMPERATURE FORECAST. AT THIS TIME THE NAM IS THE ONLY MODEL HOLDING ONTO THIS. SO IN REGARDS TO THE TEMPERATURE WITH THE POSSIBILITY OF STRATUS AND SLIGHT UPSLOPE DIRECTION MADE A SLIGHT REDUCTION IN THE HIGH TEMPERATURES. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS SUPPORT BREEZY TO WINDY ACROSS THE ENTIRE AREA. WINDS LOOK TO STAY SOUTH SOUTHEAST THE ENTIRE DAY. DEPENDING ON THE LOCATION 25 TO 35 MPH WINDS WITH GUSTS MAYBE APPROACHING 50 MPH ARE POSSIBLE. DRYLINE LOOKS TO SETUP ALONG THE COLORADO BORDER. AT THE SAME TIME A NEGATIVELY TILTED SHORTWAVE MOVES THROUGH DURING THE AFTERNOON AND EVENING HOURS. WEAK RIGHT REAR QUADRANT MAY APPROACH THE AREA LATE IN THE NIGHT. LOW LEVEL JET WILL BE OVER THE AREA AS THE WINDS STAY UP THROUGH THE NIGHT. BASED ON ABOVE MADE A SLIGHT ADJUSTMENT TO THE AFTERNOON THUNDERSTORM FORECAST. WITH THE STRENGTH OF LIFT...THE AMOUNT OF MOISTURE/INSTABILITY...AND THE LATEST TRENDS IN THE GUIDANCE...EXPANDED THE THUNDERSTORM AREA AND INCREASED THE POPS SLIGHTLY. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 1247 AM MDT TUE APR 12 2016 SLOW MOVING CUT OFF SYSTEM STILL FORECAST TO IMPACT THE AREA DURING THIS PERIOD. THE SEVERE THREAT AT THIS POINT LOOKS RATHER LIMITED DUE TO LACK OF INSTABILITY AND SHEAR. WHILE NOT ZERO...DONT THINK WE ARE LOOKING AT AN OUTBREAK...BUT RATHER A MARGINALLY SEVERE STORM OR TWO IN THE PEAK HEATING HOURS. THE BIGGER IMPACT WILL BE THE POSSIBILITY OF HEAVY RAINFALL. QPF TOTALS FROM FRIDAY TO MONDAY CURRENTLY RUNNING BETWEEN 2-3 INCHES ACROSS THE ENTIRE AREA. BEST POTENTIAL FOR HEAVY RAIN AT THE MOMENT LOOKS TO BE ON SATURDAY. MAY FINALLY DRY OUT AROUND TUESDAY WITH UPPER SYSTEM LIFTING OUT TO THE GREAT LAKES. TEMPERATURES DURING THE PERIOD WILL BE NEAR NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1111 AM MDT TUE APR 12 2016 VFR CONDITIONS FOR BOTH TAF SITES W/ ONLY SOME HIGH CLOUD OVER AREA. WINDS SSW 15-30 KTS...DIMINISHING TO AROUND 10 KTS AFTER 02Z-03Z WED. && .FIRE WEATHER... ISSUED AT 325 AM MDT TUE APR 12 2016 FOR THURSDAY...DEWPOINTS/RELATIVE HUMIDITY LOOKS HIGHER THAN WHAT WAS PREVIOUSLY IN THERE. CONSIDERING THE SLIGHT UPSLOPE DIRECTION ON THE WINDS THAT MAKES SENSE. THE RELATIVE HUMIDITIES IN THE FAR WESTERN PORTIONS OF OUR COLORADO COUNTIES ARE NEAR 20 PERCENT. THE WINDS WILL BE STRONG THERE WITH STRONGEST CORE EAST OF THE COLORADO BORDER. CONSISTENCY PROGRAM SHOWS THAT 3 HOUR CRITERIA WILL NOT BE MET BUT DEFINITELY NEED TO CONTINUE TO WATCH THIS PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JN SHORT TERM...BULLER LONG TERM...024 AVIATION...JN FIRE WEATHER...BULLER
Area Forecast Discussion National Weather Service Dodge City KS 1200 PM CDT TUE APR 12 2016 ...Updated Aviation... .UPDATE... Issued at 845 AM CDT Tue Apr 12 2016 Cancelled all fog/frost advisories and the freeze warning. Temperatures are warming and fog is lifting. UPDATE Issued at 439 AM CDT Tue Apr 12 2016 Made a call to Stanton county after observing the Stanton county airport visibility fell to 1/4 mile. Received a report that visibilities were near zero in places as of 4 am. Based on this report and where the RAP and HRRR has a light southeast wind and clear skies through daybreak have went ahead an issued a fog advisory for areas along west of a Lakin to Ulysses line. && .SHORT TERM...(Today and tonight) Issued at 257 AM CDT Tue Apr 12 2016 A trough of low pressure will develop along the lee of the Rockies today as a surface ridge axis moves from central Kansas into Missouri. 0-1KM mean temperature trend from 00z Tuesday to 00z Wednesday indicated a 3C warm up in north central Kansas and around 7C in far southwest Kansas. Given this combined with 850mb temperatures at 00z Wednesday am currently leaning towards keeping highs today mainly in the mid 60s. Tonight southerly winds will continue and the dew points will be slowly climbing back into the mid 30s. Patchy fog will not be out of the question towards daybreak in some of the cooler low lying areas as temperatures bottom out into the mid 30s to around 40 degrees. .LONG TERM...(Wednesday through Monday) Issued at 257 AM CDT Tue Apr 12 2016 A warmer temperatures will return to western Kansas Wednesday and Thursday based on the temperature trends each day in the 900mb to 850mb level. The warm up in south central Kansas may not be as dramatic as further northwest given the potential for clouds mid week north of the upper low/trough as it crosses Oklahoma along with weak cold air advection evident in the lower levels from the southeasterly winds. Windy conditions by Thursday also appears reasonable given the deepening trough of low pressure across eastern Colorado, and boundary layer winds expected from the GFS. On Thursday night there appears to be a slight chance for evening convection ahead of an approaching upper wave as it crosses western Kansas. CAPE values at 00z Friday of 800 to 1500 j/kg are forecast across western Kansas, depending on which model you like, and 0-6km shear values will be anywhere from 30 to 40 knots. Am a little concerned about the warming 700mb temperatures late day but the models have been fairly consistent with attempting to get a few storms developing on the eastern edge of the 700mb warm layer Thursday night. Models remain in decent agreement late week with an upper level low deepening and moving into the four corners area. This next upper level system will then begin to move east northeast Friday night into Saturday and this is where the models start to diverge on solutions. Confidence on which of these models will be more correct is not high but even given these differences it does appear western Kansas will enter a period of wet weather from Friday through the weekend. Preciptable water values by early Saturday are forecast to be at or above 1 inch across western Kansas so agree with the previous shift that heavy rainfall may be an issue this weekend. Exactly where and when the better opportunity for this heavy rainfall will occur is still unclear. Have therefore stayed close to the latest CRExtendedFcst_Init for the precipitation chances over the weekend period along with the cooler temperatures that will be returning. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1200 PM CDT Tue Apr 12 2016 VFR expected at prevail at GCK, DDC and HYS through Wednesday morning. Scattered cirrus. Gusty south winds at 15-25 kts will diminish around 00z and back more SE. Patchy fog possible near GCK by 12z Wed, warranting a mention of VCFG. There is a low probability of fog impacting aviation operations at GCK. Moisture advection begins tonight, as shortwave passes south of SW KS. Consensus of short term models suggests associated MVFR cigs in stratus will remain limited to a LBL-P28 line starting around 10z, with some potential for stratus to affect the DDC terminal for a few hours after 12z Wed. SE winds 5-10 kts overnight, with S/SW winds of 10-15 kts resuming around 15z Wed. && .PRELIMINARY POINT TEMPS/POPS... DDC 64 39 73 49 / 0 0 0 0 GCK 64 38 75 48 / 0 0 0 0 EHA 65 42 74 47 / 0 0 0 0 LBL 66 41 75 48 / 0 0 0 0 HYS 66 38 74 49 / 0 0 0 0 P28 65 40 71 49 / 0 10 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ UPDATE...Turner SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Turner
AREA FORECAST DISCUSSION
NWS GOODLAND KS
925 AM MDT TUE APR 12 2016 .UPDATE... ISSUED AT 925 AM MDT TUE APR 12 2016 UPDATE ISSUED TO REMOVE MENTION OF PATCHY FOG. FULL SUNSHINE OVER THE CWA ALONG WITH INCREASED SW WINDS THIS MORNING HAS ALLOWED MORNING FOG OVER SW ZONES TO DISSIPATE. SOME TWEAKS MADE TO TEMPS FROM LATEST HOURLY TREND...OTHERWISE FORECAST IS ON TRACK. && .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 325 AM MDT TUE APR 12 2016 MAIN FORECAST ISSUES WILL BE PRECIPITATION CHANCES THROUGH THURSDAY NIGHT...AND WINDS THURSDAY/THURSDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED FLOW...ALTHOUGH NOT AS MUCH OVER THE PACIFIC FROM YESTERDAY...FROM THE PACIFIC INTO EASTERN NORTH AMERICA. SPLIT FLOW IS IN PLACE OVER THE WESTERN PORTION OF THE COUNTRY WITH A CLOSED OFF LOW OVER THE DESERT SOUTHWEST. AT JET LEVEL...STARTED OUT FINE. AT MID LEVELS...MAIN ISSUE HERE WAS THE MODELS WERE NOT QUITE STRONG ENOUGH WITH THE WESTERN RIDGE. THE GFS AND CANADIAN WERE DOING THE BEST. THE NAM AND ECMWF WERE DOING THE BEST ON THE SURFACE WIND/PRESSURE FIELD. NAM WAS DOING A LITTLE BETTER THAN THE REMAINING OUTPUT ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...SOME FOG AND STRATUS OVER OR MOVING TOWARD THE WESTERN PORTION OF THE AREA AT THIS TIME. MOST HIGH RESOLUTION GUIDANCE CAPTURING THIS NICELY AND MADE ADJUSTMENTS TO THIS MORNINGS FOG FORECAST. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS SUPPORT BREEZY TO WINDY CONDITIONS OVER MOST OF THE AREA AND WILL CONTINUE THAT IN THE GRIDS. WEAK SHORTWAVE MOVES TROUGH LATE THIS AFTERNOON INTO THE EARLY EVENING WITH THE SURFACE CONVERGENCE TO THE WEST. LOW LEVEL MOISTURE IS LACKING. A FEW MODELS ARE SHOWING LIGHT QPF VERY NEAR THE NORTHWEST PORTION OF THE AREA LATE THIS AFTERNOON INTO THIS EVENING. HOWEVER MOST OF THE HIGH RESOLUTION GUIDANCE KEEPS IT TO THE WEST OF OUR AREA. THE STEERING FLOW IS LIGHT SO IF SOMETHING WOULD FORM IT WILL NOT MOVE FAR. SO RIGHT NOW AM GOING TO KEEP THIS PERIOD DRY. RECENT TRENDS IN GUIDANCE HAVE BEEN TO BE TOO COOL WITH THE MAXES. NEWER GUIDANCE SUPPORTS NUDGING UP THE HIGH TEMPERATURES AND DID SO. LIGHT WINDS ESPECIALLY IN THE WEST LATE TONIGHT WILL TEMPERATURES TO COOL TO BELOW GUIDANCE. LOOKS TO BE SOME SHALLOW MOISTURE BROUGHT UP IN ADVANCE OF THE TROUGH OVER THE WESTERN PORTION OF THE AREA...AND THERE COULD BE SOME LIGHT FOG POSSIBLE. WEDNESDAY/WEDNESDAY NIGHT...WHATEVER LIGHT FOG THERE IS WILL BURN OFF QUICKLY. MODELS ARE PRODUCING A VERY LIGHT QPF SIGNAL IN THE FAR WEST LATE IN THE AFTERNOON INTO THE EARLY EVENING. MAIN AREA OF SURFACE CONVERGENCE REMAINS TO THE WEST THROUGH THE PERIOD. A WEAK SHORTWAVE MOVES THROUGH EARLY WITH A STRONGER ONE APPROACHING LATE. FOR THE LATE AFTERNOON INTO THE EVENING...THE STEERING FLOW IS LIGHT TO NON-EXISTENT. IT DOES LOOK A LIKE A WARM AIR ADVECTION PATTERN SETTING UP LATER IN THE NIGHT. NAM SHOWS INSTABILITY AND THE GFS DOES NOT. NAM MAYBE OVERDOING THE MOISTURE. ALTHOUGH THE WARM AIR ADVECTION AND SHORTWAVE ALOFT HAS ME CONCERNED. BASED ON ABOVE REASONING AND COLLABORATION WITH WFO BOU...AM GOING TO KEEP IT DRY. MODELS SHOWING SOME STRATUS AND MAYBE SOME FOG BEING PULLED INTO THE AREA LATE IN THE NIGHT. BASED ON THAT AND COLLABORATION...INCREASED CLOUD COVER AND ADDED SOME PATCHY FOG. THURSDAY/THURSDAY NIGHT...AM A LITTLE CONCERNED THAT THE MORNING STRATUS AND MAYBE SOME FOG WILL PLAGUE THE AREA AND MAY HAVE A SIGNIFICANT AFFECT ON THE TEMPERATURE FORECAST. AT THIS TIME THE NAM IS THE ONLY MODEL HOLDING ONTO THIS. SO IN REGARDS TO THE TEMPERATURE WITH THE POSSIBILITY OF STRATUS AND SLIGHT UPSLOPE DIRECTION MADE A SLIGHT REDUCTION IN THE HIGH TEMPERATURES. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS SUPPORT BREEZY TO WINDY ACROSS THE ENTIRE AREA. WINDS LOOK TO STAY SOUTH SOUTHEAST THE ENTIRE DAY. DEPENDING ON THE LOCATION 25 TO 35 MPH WINDS WITH GUSTS MAYBE APPROACHING 50 MPH ARE POSSIBLE. DRYLINE LOOKS TO SETUP ALONG THE COLORADO BORDER. AT THE SAME TIME A NEGATIVELY TILTED SHORTWAVE MOVES THROUGH DURING THE AFTERNOON AND EVENING HOURS. WEAK RIGHT REAR QUADRANT MAY APPROACH THE AREA LATE IN THE NIGHT. LOW LEVEL JET WILL BE OVER THE AREA AS THE WINDS STAY UP THROUGH THE NIGHT. BASED ON ABOVE MADE A SLIGHT ADJUSTMENT TO THE AFTERNOON THUNDERSTORM FORECAST. WITH THE STRENGTH OF LIFT...THE AMOUNT OF MOISTURE/INSTABILITY...AND THE LATEST TRENDS IN THE GUIDANCE...EXPANDED THE THUNDERSTORM AREA AND INCREASED THE POPS SLIGHTLY. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 1247 AM MDT TUE APR 12 2016 SLOW MOVING CUT OFF SYSTEM STILL FORECAST TO IMPACT THE AREA DURING THIS PERIOD. THE SEVERE THREAT AT THIS POINT LOOKS RATHER LIMITED DUE TO LACK OF INSTABILITY AND SHEAR. WHILE NOT ZERO...DONT THINK WE ARE LOOKING AT AN OUTBREAK...BUT RATHER A MARGINALLY SEVERE STORM OR TWO IN THE PEAK HEATING HOURS. THE BIGGER IMPACT WILL BE THE POSSIBILITY OF HEAVY RAINFALL. QPF TOTALS FROM FRIDAY TO MONDAY CURRENTLY RUNNING BETWEEN 2-3 INCHES ACROSS THE ENTIRE AREA. BEST POTENTIAL FOR HEAVY RAIN AT THE MOMENT LOOKS TO BE ON SATURDAY. MAY FINALLY DRY OUT AROUND TUESDAY WITH UPPER SYSTEM LIFTING OUT TO THE GREAT LAKES. TEMPERATURES DURING THE PERIOD WILL BE NEAR NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 537 AM MDT TUE APR 12 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. AT KGLD UNTIL NEAR 14Z...6SM BR WILL BE POSSIBLE. BY MID MORNING...SOUTHERLY WINDS WILL INCREASE INTO THE 17 TO 22 KNOT RANGE WITH GUSTS UP TO 30 KNOTS WITH HIGHEST SPEEDS EXPECTED AT KGLD. THESE WINDS WILL DECREASE AND LOSE THEIR GUSTS NEAR SUNSET. && .FIRE WEATHER... ISSUED AT 325 AM MDT TUE APR 12 2016 FOR THURSDAY...DEWPOINTS/RELATIVE HUMIDITY LOOKS HIGHER THAN WHAT WAS PREVIOUSLY IN THERE. CONSIDERING THE SLIGHT UPSLOPE DIRECTION ON THE WINDS THAT MAKES SENSE. THE RELATIVE HUMIDITIES IN THE FAR WESTERN PORTIONS OF OUR COLORADO COUNTIES ARE NEAR 20 PERCENT. THE WINDS WILL BE STRONG THERE WITH STRONGEST CORE EAST OF THE COLORADO BORDER. CONSISTENCY PROGRAM SHOWS THAT 3 HOUR CRITERIA WILL NOT BE MET BUT DEFINITELY NEED TO CONTINUE TO WATCH THIS PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JN SHORT TERM...BULLER LONG TERM...024 AVIATION...BULLER FIRE WEATHER...BULLER
Area Forecast Discussion National Weather Service Dodge City KS 845 AM CDT TUE APR 12 2016 .UPDATE... Issued at 845 AM CDT Tue Apr 12 2016 Cancelled all fog/frost advisories and the freeze warning. Temperatures are warming and fog is lifting. UPDATE Issued at 439 AM CDT Tue Apr 12 2016 Made a call to Stanton county after observing the Stanton county airport visibility fell to 1/4 mile. Received a report that visibilities were near zero in places as of 4 am. Based on this report and where the RAP and HRRR has a light southeast wind and clear skies through daybreak have went ahead an issued a fog advisory for areas along west of a Lakin to Ulysses line. && .SHORT TERM...(Today and tonight) Issued at 257 AM CDT Tue Apr 12 2016 A trough of low pressure will develop along the lee of the Rockies today as a surface ridge axis moves from central Kansas into Missouri. 0-1KM mean temperature trend from 00z Tuesday to 00z Wednesday indicated a 3C warm up in north central Kansas and around 7C in far southwest Kansas. Given this combined with 850mb temperatures at 00z Wednesday am currently leaning towards keeping highs today mainly in the mid 60s. Tonight southerly winds will continue and the dew points will be slowly climbing back into the mid 30s. Patchy fog will not be out of the question towards daybreak in some of the cooler low lying areas as temperatures bottom out into the mid 30s to around 40 degrees. .LONG TERM...(Wednesday through Monday) Issued at 257 AM CDT Tue Apr 12 2016 A warmer temperatures will return to western Kansas Wednesday and Thursday based on the temperature trends each day in the 900mb to 850mb level. The warm up in south central Kansas may not be as dramatic as further northwest given the potential for clouds mid week north of the upper low/trough as it crosses Oklahoma along with weak cold air advection evident in the lower levels from the southeasterly winds. Windy conditions by Thursday also appears reasonable given the deepening trough of low pressure across eastern Colorado, and boundary layer winds expected from the GFS. On Thursday night there appears to be a slight chance for evening convection ahead of an approaching upper wave as it crosses western Kansas. CAPE values at 00z Friday of 800 to 1500 j/kg are forecast across western Kansas, depending on which model you like, and 0-6km shear values will be anywhere from 30 to 40 knots. Am a little concerned about the warming 700mb temperatures late day but the models have been fairly consistent with attempting to get a few storms developing on the eastern edge of the 700mb warm layer Thursday night. Models remain in decent agreement late week with an upper level low deepening and moving into the four corners area. This next upper level system will then begin to move east northeast Friday night into Saturday and this is where the models start to diverge on solutions. Confidence on which of these models will be more correct is not high but even given these differences it does appear western Kansas will enter a period of wet weather from Friday through the weekend. Preciptable water values by early Saturday are forecast to be at or above 1 inch across western Kansas so agree with the previous shift that heavy rainfall may be an issue this weekend. Exactly where and when the better opportunity for this heavy rainfall will occur is still unclear. Have therefore stayed close to the latest CRExtendedFcst_Init for the precipitation chances over the weekend period along with the cooler temperatures that will be returning. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 600 AM CDT Tue Apr 12 2016 MVFR vsbys will be possible in the vicinity of KGCK and KDDC through daybreak as patchy fog continues to develop across portions of southwest Kansas. A brief period of IFR vsbys cannot be ruled out at KGCK. Additionally, pockets of low level stratus will continue to develop within a southeasterly upslope flow through mid morning producing possible MVFR cigs at KGCK and KDDC. Otherwise, VFR conditions will be the general rule at all TAF sites by early this afternoon. Light southerly winds will slowly increase to around 15 to 25kt through this afternoon as a lee side trough of low pressure strengthens across eastern Colorado. The southerly winds will subside somewhat this evening with the loss of daytime heating. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 39 73 49 / 0 0 0 0 GCK 64 38 75 48 / 0 0 0 0 EHA 64 42 74 47 / 0 0 0 0 LBL 65 41 75 48 / 0 0 0 0 HYS 65 38 74 49 / 0 0 0 0 P28 64 40 71 49 / 0 10 0 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ UPDATE...Turner SHORT TERM...Burgert LONG TERM...Burgert AVIATION...JJohnson
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
612 AM CDT TUE APR 12 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 313 AM CDT TUE APR 12 2016 The region was under northwesterly flow aloft as the mid-level trough progressed eastward beyond the Great Lakes region. At the surface, high pressure was centered over Minnesota and Iowa and stretched southward across Kansas, resulting in light northeasterly winds early this morning. The combination of light winds and clear skies was resulting in good radiational cooling, which should cause temperatures to plunge into the upper 20s to low 30s by sunrise. As a result, a Freeze Warning remains in effect until 9am this morning. Surface high pressure will shift east of the region through the day, causing winds to shift to the south and southeast. This southerly component to the wind combined with mostly sunny skies will allow for seasonal conditions today with highs reaching into the low/mid 60s. Conditions will remain dry through the day with dewpoint temperatures generally staying in the 20s, resulting in relative humidity values dropping into the low to mid 20 percent range. In general, winds should remain light enough to limit any fire weather concerns across most of northeast and east central Kansas. However, there will be some elevated fire danger concerns across north central Kansas as this is where the drier conditions are expected and winds may gust upwards of 20-25mph as a weak pressure gradient begins to develop due to an advancing surface low. The region will remain wedged between surface high pressure to the east and surface low pressure to the west tonight, resulting in clear skies and light southerly winds. These southerly winds will allow overnight temperatures to be a few degrees warmer than this morning with lows in the mid/upper 30s to around 40 degrees. .LONG TERM...(Wednesday through Monday) Issued at 313 AM CDT TUE APR 12 2016 An upper level low pressure trough will move slowly eastward across the Southern Plains Wednesday through Thursday before moving off into the lower Mississippi Valley. Another upper level low in the Gulf of Alaska this morning will move into the Pacific Northwest late Wednesday then into the Rockies on Friday. The upper trough deepens over the four corners region then progresses slowly eastward across the Plains through early next week. The models continue to differ in the eastward progression with the GFS slower than the ECMWF and CMC. Will continue to favor a lean toward the non GFS solutions for the forecast. By Friday the upper low will eject lead shortwave energy into the Plains by late Friday with a chance of showers and thunderstorms across north central Kansas. Precipitation chances will gradually increase from west to east through the weekend and expect periods of showers and thunderstorms off and on into early next week. The slow eastward progression will lead to increasingly deep moisture from the Gulf into the Plains. This will lead to precipitable water values as high as 1.25 inches across eastern Kansas by Monday. Could see some moderate rainfall across the area which will help to alleviate the abnormally dry conditions that exist across north central and northeast Kansas. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning) Issued at 609 AM CDT TUE APR 12 2016 For the 12z TAFs, VFR conditions are expected through the period. Winds will shift from east to southeast this morning as surface high pressure shifts east of the area. Winds should stay near or below 12kts through the period. && .TOP Watches/Warnings/Advisories... Freeze Warning until 9 AM CDT this morning for KSZ008>012- 020>024-026-034>040-054>056-058-059. && $$ SHORT TERM...Hennecke LONG TERM...53 AVIATION...Hennecke
Area Forecast Discussion National Weather Service Dodge City KS 602 AM CDT TUE APR 12 2016 ...UPDATE TO AVIATION... .UPDATE... Issued at 439 AM CDT Tue Apr 12 2016 Made a call to Stanton county after observing the Stanton county airport visibility fell to 1/4 mile. Received a report that visibilities were near zero in places as of 4 am. Based on this report and where the RAP and HRRR has a light southeast wind and clear skies through daybreak have went ahead an issued a fog advisory for areas along west of a Lakin to Ulysses line. && .SHORT TERM...(Today and tonight) Issued at 257 AM CDT Tue Apr 12 2016 A trough of low pressure will develop along the lee of the Rockies today as a surface ridge axis moves from central Kansas into Missouri. 0-1KM mean temperature trend from 00z Tuesday to 00z Wednesday indicated a 3C warm up in north central Kansas and around 7C in far southwest Kansas. Given this combined with 850mb temperatures at 00z Wednesday am currently leaning towards keeping highs today mainly in the mid 60s. Tonight southerly winds will continue and the dew points will be slowly climbing back into the mid 30s. Patchy fog will not be out of the question towards daybreak in some of the cooler low lying areas as temperatures bottom out into the mid 30s to around 40 degrees. .LONG TERM...(Wednesday through Monday) Issued at 257 AM CDT Tue Apr 12 2016 A warmer temperatures will return to western Kansas Wednesday and Thursday based on the temperature trends each day in the 900mb to 850mb level. The warm up in south central Kansas may not be as dramatic as further northwest given the potential for clouds mid week north of the upper low/trough as it crosses Oklahoma along with weak cold air advection evident in the lower levels from the southeasterly winds. Windy conditions by Thursday also appears reasonable given the deepening trough of low pressure across eastern Colorado, and boundary layer winds expected from the GFS. On Thursday night there appears to be a slight chance for evening convection ahead of an approaching upper wave as it crosses western Kansas. CAPE values at 00z Friday of 800 to 1500 j/kg are forecast across western Kansas, depending on which model you like, and 0-6km shear values will be anywhere from 30 to 40 knots. Am a little concerned about the warming 700mb temperatures late day but the models have been fairly consistent with attempting to get a few storms developing on the eastern edge of the 700mb warm layer Thursday night. Models remain in decent agreement late week with an upper level low deepening and moving into the four corners area. This next upper level system will then begin to move east northeast Friday night into Saturday and this is where the models start to diverge on solutions. Confidence on which of these models will be more correct is not high but even given these differences it does appear western Kansas will enter a period of wet weather from Friday through the weekend. Preciptable water values by early Saturday are forecast to be at or above 1 inch across western Kansas so agree with the previous shift that heavy rainfall may be an issue this weekend. Exactly where and when the better opportunity for this heavy rainfall will occur is still unclear. Have therefore stayed close to the latest CRExtendedFcst_Init for the precipitation chances over the weekend period along with the cooler temperatures that will be returning. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 600 AM CDT Tue Apr 12 2016 MVFR vsbys will be possible in the vicinity of KGCK and KDDC through daybreak as patchy fog continues to develop across portions of southwest Kansas. A brief period of IFR vsbys cannot be ruled out at KGCK. Additionally, pockets of low level stratus will continue to develop within a southeasterly upslope flow through mid morning producing possible MVFR cigs at KGCK and KDDC. Otherwise, VFR conditions will be the general rule at all TAF sites by early this afternoon. Light southerly winds will slowly increase to around 15 to 25kt through this afternoon as a lee side trough of low pressure strengthens across eastern Colorado. The southerly winds will subside somewhat this evening with the loss of daytime heating. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 39 73 49 / 0 0 0 0 GCK 64 38 75 48 / 0 0 0 0 EHA 64 42 74 47 / 0 0 0 0 LBL 65 41 75 48 / 0 0 0 0 HYS 65 38 74 49 / 0 0 0 0 P28 64 40 71 49 / 0 10 0 0 && .DDC Watches/Warnings/Advisories... Frost Advisory until 9 AM CDT this morning for KSZ030-043>045- 063-064-076>081-086>090. Freeze Warning until 9 AM CDT this morning for KSZ031-046-065- 066. Dense Fog Advisory until 9 AM CDT /8 AM MDT/ this morning for KSZ061-062-074-075. && $$ UPDATE...Burgert SHORT TERM...Burgert LONG TERM...Burgert AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS GOODLAND KS
335 AM MDT TUE APR 12 2016 .SHORT TERM...(TODAY THROUGH THURSDAY NIGHT) ISSUED AT 325 AM MDT TUE APR 12 2016 MAIN FORECAST ISSUES WILL BE PRECIPITATION CHANCES THROUGH THURSDAY NIGHT...AND WINDS THURSDAY/THURSDAY NIGHT. SATELLITE SHOWING AN AMPLIFIED FLOW...ALTHOUGH NOT AS MUCH OVER THE PACIFIC FROM YESTERDAY...FROM THE PACIFIC INTO EASTERN NORTH AMERICA. SPLIT FLOW IS IN PLACE OVER THE WESTERN PORTION OF THE COUNTRY WITH A CLOSED OFF LOW OVER THE DESERT SOUTHWEST. AT JET LEVEL...STARTED OUT FINE. AT MID LEVELS...MAIN ISSUE HERE WAS THE MODELS WERE NOT QUITE STRONG ENOUGH WITH THE WESTERN RIDGE. THE GFS AND CANADIAN WERE DOING THE BEST. THE NAM AND ECMWF WERE DOING THE BEST ON THE SURFACE WIND/PRESSURE FIELD. NAM WAS DOING A LITTLE BETTER THAN THE REMAINING OUTPUT ON THE LOW LEVEL THERMAL FIELD. TODAY/TONIGHT...SOME FOG AND STRATUS OVER OR MOVING TOWARD THE WESTERN PORTION OF THE AREA AT THIS TIME. MOST HIGH RESOLUTION GUIDANCE CAPTURING THIS NICELY AND MADE ADJUSTMENTS TO THIS MORNINGS FOG FORECAST. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS SUPPORT BREEZY TO WINDY CONDITIONS OVER MOST OF THE AREA AND WILL CONTINUE THAT IN THE GRIDS. WEAK SHORTWAVE MOVES TROUGH LATE THIS AFTERNOON INTO THE EARLY EVENING WITH THE SURFACE CONVERGENCE TO THE WEST. LOW LEVEL MOISTURE IS LACKING. A FEW MODELS ARE SHOWING LIGHT QPF VERY NEAR THE NORTHWEST PORTION OF THE AREA LATE THIS AFTERNOON INTO THIS EVENING. HOWEVER MOST OF THE HIGH RESOLUTION GUIDANCE KEEPS IT TO THE WEST OF OUR AREA. THE STEERING FLOW IS LIGHT SO IF SOMETHING WOULD FORM IT WILL NOT MOVE FAR. SO RIGHT NOW AM GOING TO KEEP THIS PERIOD DRY. RECENT TRENDS IN GUIDANCE HAVE BEEN TO BE TOO COOL WITH THE MAXES. NEWER GUIDANCE SUPPORTS NUDGING UP THE HIGH TEMPERATURES AND DID SO. LIGHT WINDS ESPECIALLY IN THE WEST LATE TONIGHT WILL TEMPERATURES TO COOL TO BELOW GUIDANCE. LOOKS TO BE SOME SHALLOW MOISTURE BROUGHT UP IN ADVANCE OF THE TROUGH OVER THE WESTERN PORTION OF THE AREA...AND THERE COULD BE SOME LIGHT FOG POSSIBLE. WEDNESDAY/WEDNESDAY NIGHT...WHATEVER LIGHT FOG THERE IS WILL BURN OFF QUICKLY. MODELS ARE PRODUCING A VERY LIGHT QPF SIGNAL IN THE FAR WEST LATE IN THE AFTERNOON INTO THE EARLY EVENING. MAIN AREA OF SURFACE CONVERGENCE REMAINS TO THE WEST THROUGH THE PERIOD. A WEAK SHORTWAVE MOVES THROUGH EARLY WITH A STRONGER ONE APPROACHING LATE. FOR THE LATE AFTERNOON INTO THE EVENING...THE STEERING FLOW IS LIGHT TO NON-EXISTENT. IT DOES LOOK A LIKE A WARM AIR ADVECTION PATTERN SETTING UP LATER IN THE NIGHT. NAM SHOWS INSTABILITY AND THE GFS DOES NOT. NAM MAYBE OVERDOING THE MOISTURE. ALTHOUGH THE WARM AIR ADVECTION AND SHORTWAVE ALOFT HAS ME CONCERNED. BASED ON ABOVE REASONING AND COLLABORATION WITH WFO BOU...AM GOING TO KEEP IT DRY. MODELS SHOWING SOME STRATUS AND MAYBE SOME FOG BEING PULLED INTO THE AREA LATE IN THE NIGHT. BASED ON THAT AND COLLABORATION...INCREASED CLOUD COVER AND ADDED SOME PATCHY FOG. THURSDAY/THURSDAY NIGHT...AM A LITTLE CONCERNED THAT THE MORNING STRATUS AND MAYBE SOME FOG WILL PLAGUE THE AREA AND MAY HAVE A SIGNIFICANT AFFECT ON THE TEMPERATURE FORECAST. AT THIS TIME THE NAM IS THE ONLY MODEL HOLDING ONTO THIS. SO IN REGARDS TO THE TEMPERATURE WITH THE POSSIBILITY OF STRATUS AND SLIGHT UPSLOPE DIRECTION MADE A SLIGHT REDUCTION IN THE HIGH TEMPERATURES. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS SUPPORT BREEZY TO WINDY ACROSS THE ENTIRE AREA. WINDS LOOK TO STAY SOUTH SOUTHEAST THE ENTIRE DAY. DEPENDING ON THE LOCATION 25 TO 35 MPH WINDS WITH GUSTS MAYBE APPROACHING 50 MPH ARE POSSIBLE. DRYLINE LOOKS TO SETUP ALONG THE COLORADO BORDER. AT THE SAME TIME A NEGATIVELY TILTED SHORTWAVE MOVES THROUGH DURING THE AFTERNOON AND EVENING HOURS. WEAK RIGHT REAR QUADRANT MAY APPROACH THE AREA LATE IN THE NIGHT. LOW LEVEL JET WILL BE OVER THE AREA AS THE WINDS STAY UP THROUGH THE NIGHT. BASED ON ABOVE MADE A SLIGHT ADJUSTMENT TO THE AFTERNOON THUNDERSTORM FORECAST. WITH THE STRENGTH OF LIFT...THE AMOUNT OF MOISTURE/INSTABILITY...AND THE LATEST TRENDS IN THE GUIDANCE...EXPANDED THE THUNDERSTORM AREA AND INCREASED THE POPS SLIGHTLY. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 1247 AM MDT TUE APR 12 2016 SLOW MOVING CUT OFF SYSTEM STILL FORECAST TO IMPACT THE AREA DURING THIS PERIOD. THE SEVERE THREAT AT THIS POINT LOOKS RATHER LIMITED DUE TO LACK OF INSTABILITY AND SHEAR. WHILE NOT ZERO...DONT THINK WE ARE LOOKING AT AN OUTBREAK...BUT RATHER A MARGINALLY SEVERE STORM OR TWO IN THE PEAK HEATING HOURS. THE BIGGER IMPACT WILL BE THE POSSIBILITY OF HEAVY RAINFALL. QPF TOTALS FROM FRIDAY TO MONDAY CURRENTLY RUNNING BETWEEN 2-3 INCHES ACROSS THE ENTIRE AREA. BEST POTENTIAL FOR HEAVY RAIN AT THE MOMENT LOOKS TO BE ON SATURDAY. MAY FINALLY DRY OUT AROUND TUESDAY WITH UPPER SYSTEM LIFTING OUT TO THE GREAT LAKES. TEMPERATURES DURING THE PERIOD WILL BE NEAR NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1010 PM MDT MON APR 11 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT MCK AND GLD. SURFACE HIGH PRESSURE SHIFTS TO THE EAST AND A LEE TROUGH DEVELOPS ALONG THE FRONT RANGE. SKIES CLEAR BY SUNRISE AND LIGHT SOUTH WINDS BECOME GUSTY AFTER 14Z. GUSTY SOUTH WINDS WILL CONTINUE THROUGH THE DAY AND BECOME LIGHT AGAIN BY 03Z AS THE NIGHT TIME INVERSION DEVELOPS. && .FIRE WEATHER... ISSUED AT 325 AM MDT TUE APR 12 2016 FOR THURSDAY...DEWPOINTS/RELATIVE HUMIDITY LOOKS HIGHER THAN WHAT WAS PREVIOUSLY IN THERE. CONSIDERING THE SLIGHT UPSLOPE DIRECTION ON THE WINDS THAT MAKES SENSE. THE RELATIVE HUMIDITIES IN THE FAR WESTERN PORTIONS OF OUR COLORADO COUNTIES ARE NEAR 20 PERCENT. THE WINDS WILL BE STRONG THERE WITH STRONGEST CORE EAST OF THE COLORADO BORDER. CONSISTENCY PROGRAM SHOWS THAT 3 HOUR CRITERIA WILL NOT BE MET BUT DEFINITELY NEED TO CONTINUE TO WATCH THIS PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...BULLER LONG TERM...024 AVIATION...LOCKHART FIRE WEATHER...BULLER
Area Forecast Discussion National Weather Service Dodge City KS 445 AM CDT TUE APR 12 2016 ...Updated to issue a dense fog advisory... .UPDATE... Issued at 439 AM CDT Tue Apr 12 2016 Made a call to Stanton county after observing the Stanton county airport visibility fell to 1/4 mile. Received a report that visibilities were near zero in places as of 4 am. Based on this report and where the RAP and HRRR has a light southeast wind and clear skies through daybreak have went ahead an issued a fog advisory for areas along west of a Lakin to Ulysses line. && .SHORT TERM...(Today and tonight) Issued at 257 AM CDT Tue Apr 12 2016 A trough of low pressure will develop along the lee of the Rockies today as a surface ridge axis moves from central Kansas into Missouri. 0-1KM mean temperature trend from 00z Tuesday to 00z Wednesday indicated a 3C warm up in north central Kansas and around 7C in far southwest Kansas. Given this combined with 850mb temperatures at 00z Wednesday am currently leaning towards keeping highs today mainly in the mid 60s. Tonight southerly winds will continue and the dew points will be slowly climbing back into the mid 30s. Patchy fog will not be out of the question towards daybreak in some of the cooler low lying areas as temperatures bottom out into the mid 30s to around 40 degrees. .LONG TERM...(Wednesday through Monday) Issued at 257 AM CDT Tue Apr 12 2016 A warmer temperatures will return to western Kansas Wednesday and Thursday based on the temperature trends each day in the 900mb to 850mb level. The warm up in south central Kansas may not be as dramatic as further northwest given the potential for clouds mid week north of the upper low/trough as it crosses Oklahoma along with weak cold air advection evident in the lower levels from the southeasterly winds. Windy conditions by Thursday also appears reasonable given the deepening trough of low pressure across eastern Colorado, and boundary layer winds expected from the GFS. On Thursday night there appears to be a slight chance for evening convection ahead of an approaching upper wave as it crosses western Kansas. CAPE values at 00z Friday of 800 to 1500 j/kg are forecast across western Kansas, depending on which model you like, and 0-6km shear values will be anywhere from 30 to 40 knots. Am a little concerned about the warming 700mb temperatures late day but the models have been fairly consistent with attempting to get a few storms developing on the eastern edge of the 700mb warm layer Thursday night. Models remain in decent agreement late week with an upper level low deepening and moving into the four corners area. This next upper level system will then begin to move east northeast Friday night into Saturday and this is where the models start to diverge on solutions. Confidence on which of these models will be more correct is not high but even given these differences it does appear western Kansas will enter a period of wet weather from Friday through the weekend. Preciptable water values by early Saturday are forecast to be at or above 1 inch across western Kansas so agree with the previous shift that heavy rainfall may be an issue this weekend. Exactly where and when the better opportunity for this heavy rainfall will occur is still unclear. Have therefore stayed close to the latest CRExtendedFcst_Init for the precipitation chances over the weekend period along with the cooler temperatures that will be returning. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1225 AM CDT Tue Apr 12 2016 Light winds early this morning will increase into the 10 to 15 knot range by mid day as a trough of low pressure at the surface develops across eastern Colorado. A weak up slope flow combined with the recent rainfall may give rise to some early morning fog/stratus near and west of the GCK area. At this time RAP and HRRR suggests the ceilings and visibilities at GCK early this morning may briefly fall back into the MVFR category between 11z and 13z Tuesday. Elsewhere VFR conditions can be expected. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 39 73 49 / 0 0 0 0 GCK 64 38 75 48 / 0 0 0 0 EHA 64 42 74 47 / 0 0 0 0 LBL 65 41 75 48 / 0 0 0 0 HYS 65 38 74 49 / 0 0 0 0 P28 64 40 71 49 / 0 10 0 0 && .DDC Watches/Warnings/Advisories... Frost Advisory until 9 AM CDT this morning for KSZ030-043>045- 063-064-076>081-086>090. Freeze Warning until 9 AM CDT this morning for KSZ031-046-065- 066. Dense Fog Advisory until 9 AM CDT /8 AM MDT/ this morning for KSZ061-062-074-075. && $$ UPDATE...Burgert SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS GOODLAND KS
101 AM MDT TUE APR 12 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 207 PM MDT MON APR 11 2016 ACROSS THE FORECAST AREA THIS AFTERNOON...MUCH OF THE CWA HAS FINALLY GONE MSUNNY/SUNNY...WITH ONLY WESTERN PORTIONS OF THE CWA STILL SEEING LINGERING CLOUD COVER ASSOCIATED WITH MOISTURE STILL RUNNING UP ALONG THE NORTH SIDE OF THE BOUNDARY THAT SITS WELL TO OUR SOUTH. THIS IS WORKING IN TANDEM WITH HIGH PRESSURE NOSING SOUTHWARD FUNNELING MOISTURE ON ITS RETURN FLOW...MAINLY INTO EASTERN COLORADO. WHERE ZONES HAVE GONE MORE TO THE SUNNY SIDE..TEMPS HAVE REACHED NEAR FORECASTED NUMBERS IN THE LOWER TO MID 50S. THOSE LOCALES SEEING MCLOUDY/CLOUDY CONDITIONS PERSIST ARE ONLY IN THE MID 40S AT BEST BUT SHOULD STILL SEE A FEW MORE DEGREES INCREASE AS THE AFTERNOON PROGRESSES AND THE CLOUD COVER CONTINUES TO WANE. GOING INTO TONIGHT AND TUESDAY...HIGH PRESSURE WILL CONTINUE TO NOSE SOUTHWARD THRU THE CENTRAL PLAINS...WITH EVENTUALLY A LEE-SIDE TROUGH DEVELOPING GOING INTO TUESDAY. THIS WILL ALLOW THE WIND FIELD TO SHIFT FROM A MORE SSE REGIME TO MORE OF A SSW ONE...ESPECIALLY BY TUESDAY MORNING. OVERALL PARTLY CLOUDY SKIES WILL ENSUE THRU THE OVERNIGHT HOURS INTO TUESDAY. AREAS ACROSS NE COLORADO WILL CONTINUE TO SEE LOWER LEVEL CLOUDS ALONG THE BOUNDARY BUT GIVE WAY TOWARDS PCLDY CONDITIONS BY MORNING AS THE TROUGH SETS UP OVER THE FRONT RANGE. NO PRECIP FOR TONIGHT INTO TUESDAY. FOR TEMPS...CLEARING SKIES OVERNIGHT WILL ALLOW TEMPS TO DROP BACK INTO THE LOWER TO MID 30S BUT FOR MAINLY AREAS STILL AT OR JUST ABOVE NORMAL. HIGH TEMPS FOR TUESDAY WILL RANGE FROM THE MID 60S TO NEAR 70F. WITH GRADIENT DEVELOPING BETWEEN THE SURFACE RIDGE TO OUR EAST AND THE TROUGH OVER THE FRONT RANGE...EXPECTING WINDS TO BEGIN HITTING THE 15-25 MPH RANGE AROUND 14Z-15Z...AND PERSIST FOR THE REMAINDER OF THE DAY. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 1247 AM MDT TUE APR 12 2016 SLOW MOVING CUT OFF SYSTEM STILL FORECAST TO IMPACT THE AREA DURING THIS PERIOD. THE SEVERE THREAT AT THIS POINT LOOKS RATHER LIMITED DUE TO LACK OF INSTABILITY AND SHEAR. WHILE NOT ZERO...DONT THINK WE ARE LOOKING AT AN OUTBREAK...BUT RATHER A MARGINALLY SEVERE STORM OR TWO IN THE PEAK HEATING HOURS. THE BIGGER IMPACT WILL BE THE POSSIBILITY OF HEAVY RAINFALL. QPF TOTALS FROM FRIDAY TO MONDAY CURRENTLY RUNNING BETWEEN 2-3 INCHES ACROSS THE ENTIRE AREA. BEST POTENTIAL FOR HEAVY RAIN AT THE MOMENT LOOKS TO BE ON SATURDAY. MAY FINALLY DRY OUT AROUND TUESDAY WITH UPPER SYSTEM LIFTING OUT TO THE GREAT LAKES. TEMPERATURES DURING THE PERIOD WILL BE NEAR NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1010 PM MDT MON APR 11 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT MCK AND GLD. SURFACE HIGH PRESSURE SHIFTS TO THE EAST AND A LEE TROUGH DEVELOPS ALONG THE FRONT RANGE. SKIES CLEAR BY SUNRISE AND LIGHT SOUTH WINDS BECOME GUSTY AFTER 14Z. GUSTY SOUTH WINDS WILL CONTINUE THROUGH THE DAY AND BECOME LIGHT AGAIN BY 03Z AS THE NIGHT TIME INVERSION DEVELOPS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JN LONG TERM...024 AVIATION...LOCKHART
Area Forecast Discussion National Weather Service Dodge City KS 1228 AM CDT TUE APR 12 2016 ...Updated Synopsis and Aviation Discussion... .SYNOPSIS... Issued at 1225 AM CDT Tue Apr 12 2016 At 00z Tuesday a 500 mb low was located over Baja California. Further east across the central and southern Plains there was a weaker upper level trough extended from eastern Kansas to southwest Oklahoma. A west to northwest flow was evident at the 700 mb and 500 mb level over the Central and Northern Rockies. At the surface earlier this evening an area of high pressure was located across southwest and south central Kansas. && .SHORT TERM...(This evening through Tuesday) Issued at 1235 PM CDT Mon Apr 11 2016 Just what the doctor ordered. Widespread beneficial rainfall was greeted across most of SW KS this morning. Much of the area reported measurable rainfall, with the noted exception of the NE zones. The rainfall winners were, far and away, Haskell and Seward counties, where radar estimates near 4 inches have fallen south of Sublette along U.S. Highway 83. An areal flood warning was hoisted in this area, where deformation forcing axis continues to pivot and slowly shrink. All rain will end by mid afternoon, followed by rapid clearing from north to south this evening, as surface high pressure ridge axis builds into SW KS. Expecting strong radiational cooling tonight as sky clears and winds go light and variable. Low temperatures Tuesday morning will be several degrees below normal, in the low to mid 30s. Eastern counties will observe the coolest temperatures, at or just below freezing for several hours, under the ridge axis near sunrise. Today`s rainfall has added lots of moisture into the boundary layer, making areas of frost and/or fog likely. Mentioned both frost/fog in the grids. Return flow and south winds will help to keep temperatures above freezing tonight across western zones. Maintained the frost/freeze headlines as inherited. Tuesday...Mostly sunny, dry, breezy and warmer. Return southerly flow will be well established by mid morning, with south winds averaging 15-25 mph. Afternoon temperatures not too far from mid-April normals in the mid 60s. .LONG TERM...(Tuesday night through Monday) Issued at 255 PM CDT Mon Apr 11 2016 ...The potential is increasing for a widespread heavy rain event across SW KS this weekend.... Wednesday...Mostly sunny and much warmer. Southern stream shortwave passes SE of SW KS, with no impacts expected. Broad ridging from the Desert SW will deliver highs in the mid 70s with breezy south winds. Thursday...The warmest day of the forecast period. Still dry, as forcing for precipitation remains well west. Quite windy Thursday afternoon, in response to strong leeside cyclogenesis in eastern Colorado. SE winds of 20-30 mph will be common with gusts near 45 mph. Lack of a SW`ly downslope component will keep afternoon temperatures capped in the upper 70s to near 80. Friday...Synoptic pattern becomes very blocky, with all models unanimously depicting a strong omega block over North America. This portends very well for a dry SW KS, as the strong closed low near the Four Corners Friday afternoon will only very slowly inch out toward SW KS over the upcoming weekend. As the upper trough approaches and the upper high over the Great Lakes doesn`t budge, moisture transport from the Gulf of Mexico will be well established, strong and persistent. With slow synoptic movement, several rounds of rain and/or thunderstorms are likely as various vorticity maxima rotate through the southern plains. The first round of scattered thunderstorms is expected Friday afternoon and evening, as the dryline activates. Although details are impossible to determine this far out, all medium range models suggest severe convection is possible Friday afternoon. Given the downstream block, and the preference to the slower solutions, strongest jet support will likely remain west of SW KS Friday. For this reason, kept pops in the scattered (<50%) category. Saturday and Sunday...Confidence is high SW KS will receive several rounds of rain and/or thunderstorms, with significant rainfall amounts likely. Although exact storm track and mesoscale evolution will determine rain amounts, forecaster confidence is high on rainfall occurring, and CR_init pop grids are in the likely category even this far out. Temperatures will show a cooling trend with clouds and rain. Initial estimate is primary severe threat this weekend will be south and west of SW KS, but this is preliminary, and this potential will be monitored carefully through the week. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1225 AM CDT Tue Apr 12 2016 Light winds early this morning will increase into the 10 to 15 knot range by mid day as a trough of low pressure at the surface develops across eastern Colorado. A weak up slope flow combined with the recent rainfall may give rise to some early morning fog/stratus near and west of the GCK area. At this time RAP and HRRR suggests the ceilings and visibilities at GCK early this morning may briefly fall back into the MVFR category between 11z and 13z Tuesday. Elsewhere VFR conditions can be expected. && .PRELIMINARY POINT TEMPS/POPS... DDC 33 63 39 73 / 0 0 0 0 GCK 34 64 38 75 / 10 0 0 0 EHA 36 64 42 74 / 10 0 0 0 LBL 35 65 41 75 / 30 0 0 0 HYS 31 65 38 74 / 0 0 0 0 P28 34 64 40 71 / 30 0 10 0 && .DDC Watches/Warnings/Advisories... Frost Advisory from 4 AM to 9 AM CDT this morning for KSZ030- 043>045-063-064-076>081-086>090. Freeze Warning from 4 AM to 9 AM CDT this morning for KSZ031-046- 065-066. && $$ SYNOPSIS...Burgert SHORT TERM...Turner LONG TERM...Turner AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
428 PM CDT TUE APR 12 2016 .SHORT TERM... MULTI DAY RAIN EVENT IS SET TO UNFOLD THROUGH THURSDAY OVER THE FORECAST AREA. THIS MORNING WE HAVE A BATCH OF SHOWERS AND THUNDERSTORMS MOVE THROUGH AS A FRONTAL BOUNDARY STALLS OVER THE AREA TODAY. PRECIPITABLE WATER VALUES WILL BE ON THE RISE OVER THE NEXT 12 HOURS. COMBINE THAT WITH SHORTWAVE ENERGY EXPECTED TO MOVE OVER THE REGION WITH THE STALLED FRONTAL BOUNDARY SETS THE STAGE FOR A SHOT OF HEAVY RAIN OVER THE ENTIRE FORECAST AREA FOR STARTING LATE TONIGHT INTO WEDNESDAY AND THURSDAY...AND MAYBE EVEN LINGERING INTO FRIDAY. WE SHOULD REMAIN FAIRLY DRY THROUGH THIS EVENING. THE HRRR GUIDANCE SUGGESTS A COMPLEX OF SHOWERS AND STORMS MOVING ACROSS THE AREA EARLY WEDNESDAY MORNING...BUT OTHER HI RES AND GLOBAL GUIDANCE DOES NOT QUITE SHOW THAT PLAYING OUT BUT THEY DO SHOW A LARGE AREA OF SHOWERS AND THUNDERSTORMS MOVING THROUGH THE AREA WEDNESDAY. SEVERE WEATHER DOES NOT LOOK TO BE AN ISSUE AT ALL THE MAIN THREAT IS THE HEAVY RAINFALL THAT COULD OCCUR. WITH WEAK WINDS ALOFT...WITH WARM CLOUD LAYER DEPTHS...A SUFFICIENT TRIGGER AND STALLED FRONT ALL POINT TO PRETTY DECENT RAIN AMOUNTS THROUGH THE SHORT TERM. THE WEATHER PREDICTION CENTER HAS OUR AREA IN A SLIGHT RISK FOR FLASH FLOODING WHICH MEANS THAT RAINFALL AMOUNTS HAVE A HIGHER CHANCE OF EXCEEDING FLASH FLOOD GUIDANCE ON TOMORROW AND THEY ALSO HAVE THAT SAME OUTLOOK FOR THE EASTERN PORTIONS OF THE FORECAST AREA ON THURSDAY AS WELL. WPC ALSO EXPECTS A SWATH OF 4 INCH RAINFALL AMOUNTS THROUGH THE MAJORITY OF THE FORECAST AREA THROUGH THURSDAY. SO WE EXPECT MOST AREAS TO SEE 2 TO 4 INCHES OF RAIN THROUGH THURSDAY...AND WE COULD SEE SOME LOCALLY HIGHER AMOUNTS REACHING UP TO 6 INCHES IN SOME AREAS THROUGH THURSDAY. AS FOR NOW WE HAVE DECIDED NOT TO ISSUE A FLASH FLOOD WARNING ALTHOUGH IT WAS CONSIDERED FOR THIS FORECAST PACKAGE. DUE TO THE RELATIVELY DRY CONDITIONS WE HAVE HAD OVER THE LAST FEW DAYS WE THINK THE GROUND CAN HANDLE A LITTLE BIT MORE RAINFALL BEFORE IT BECOMES AN ISSUE...HOWEVER...WE WILL NEED TO WATCH THIS EVENT AS IT UNFOLDS FOR THE POSSIBILITY OF FLASH FLOOD WATCHES OR WARNINGS BEING ISSUED OVER THE NEXT DAY OR SO. 13/MH .LONG TERM... BEYOND THURSDAY...FORECAST CONFIDENCE DROPS CONSIDERABLY. ECMWF/GFS/CANADIAN MODELS ALL DEVELOP AN OMEGA BLOCK OVER THE EASTERN THIRD OF THE COUNTRY OVER THE WEEKEND. THERE ARE STILL SOME DIFFERENCES IN THE MODELS BUT THESE RUNS SUGGEST THE WE SHOULD BE FAIRLY DRY OVER THE WEEKEND. WE CAN NOT RULE OUT A SHOWER OR STORM BEING ON THE EDGE OF THE BLOCK. TRENDING EXTENDED TEMPERATURES TOWARD THE WARMER END OF GUIDANCE. NOT MUCH CHANGE IN THE FORECAST FROM PREVIOUS UPDATE. HAVE MAINTAINED A BLEND OF GUIDANCE IN THE EXTENDED. 13/MH && .AVIATION... THE CONVECTIVE THREAT HAS DIMINISHED GREATLY AT MOST OF THE TERMINALS OVER THE LAST COUPLE OF HOURS...WITH ONLY SOME SCATTERED SHOWERS LINGERING AROUND KHUM. THESE SHOWERS SHOULD BEGIN TO DISSIPATE LATER THIS AFTERNOON AS SOME DRIER AND MORE STABLE AIR ADVECTS IN ALOFT. OVERALL...A BROKEN TO OVERCAST DECK RANGING FROM 2500 TO 4500 FEET IS EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING. HOWEVER...AFTER 06Z...ANOTHER ROUND OF STRATUS BUILD DOWN IS EXPECTED TO OCCUR WHICH SHOULD PUSH CEILINGS BACK BELOW 500 FEET AT MOST TERMINALS BY 09Z. THESE PREVAILING LIFR CONDITIONS SHOULD PERSIST INTO THE MORNING TOMORROW...AS A BROAD AREA OF MODERATE RAIN DEVELOPS. /32/ && .MARINE... MOST OF THE COASTAL WATERS ARE QUIET AT THIS TIME BUT ADDITIONAL SHRA AND TSRA WILL DEVELOP OVERNIGHT AND OVER THE NEXT 2 DAYS. BY FRI HIGH PRESSURE WILL BUILD OVER THE SERN CONUS WITH PERSISTENT LOW PRESSURE ALONG THE LEE OF THE ROCKIES. THIS WILL TIGHTEN THE PRESSURE GRADIENT LEADING TO MODERATE TO STRONG ERLY/ONSHORE FLOW LATE FRI AND THROUGH THE WEEKEND. SCS OR ADVISORIES WILL LIKELY BE NEEDED FOR AN EXTENDED PERIOD OF TIME. THE PERSISTENT AND STRENGTH OF THE ONSHORE FLOW COULD ALSO RESULT IN TIDAL ISSUES THIS WEEKEND AND EARLY NEXT WEEK. /CAB/ && .DECISION SUPPORT... .DSS CODE....BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...MINOR RIVER FLOODING. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 58 70 58 75 / 70 100 60 50 BTR 62 73 61 76 / 80 100 60 60 ASD 63 73 62 75 / 80 100 60 70 MSY 66 74 64 75 / 80 100 60 70 GPT 64 71 63 72 / 80 100 60 70 PQL 62 73 61 73 / 70 100 60 80 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
416 AM EDT TUE APR 12 2016 .SYNOPSIS... LOW PRESSURE WILL PASS TO THE NORTH OF THE REGION TODAY SENDING A COLD FRONT ACROSS THE AREA BY THIS EVENING. HIGH PRESSURE WILL BUILD TOWARD THE REGION FROM THE WEST WEDNESDAY THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... RAIN AND WIND THE MAIN ITEMS FOR THIS TERM. LATEST SFC ANALYSIS SHOWED THE WARM FRONT LIFTING ACROSS FAR NORTHERN MAINE W/THE ASSOCIATED FRONT STILL WELL BACK INTO QUEBEC. RAIN HAS FILLED BACK IN OVER THE LAST 3 HRS W/SOME POCKETS OF HEAVIER RAIN ACROSS CENTRAL AND DOWNEAST AREAS PER THE RADAR LOOP. WILL SEE RAIN THROUGH MUCH OF THE DAY TODAY W/PERIODS OF HEAVIER BANDS. IR SATELLITE IMAGERY SHOWED SOME ENHANCEMENT MOVING UP ACROSS SOUTHERN NYS MOVING NE. SOME HEAVIER RAINFALL UNDER THIS ENHANCEMENT. THE LATEST RUN OF THE HRRR 3KM AND NAM12 MODEL WERE HANDLING THINGS WELL ATTM. STILL LOOKING FOR AN ADDITIONAL 0.25 TO 0.50 INCHES OF RAIN BY THIS AFTERNOON. THIS WILL LEAD TO RISES ON RIVERS AND STREAMS AND POSSIBLE ICE MOVEMENT. MILDER TEMPS IN THE 40S AND 50S WILL AID IN THE POTENTIAL FOR THAT ICE MOVEMENT. MORE ON THIS IN THE HYDROLOGY SECTION BELOW. WINDS WILL BE ANOTHER ISSUE TODAY ESPECIALLY ACROSS THE DOWNEAST REGION, ESPECIALLY THE COAST. A LVL JET OF 55 KTS PROGGED TO MOVE ACROSS THE DOWNEAST REGION THIS MORNING. BUFKIT SOUNDINGS FROM THE NAM AND GFS SHOW GUST POTENTIAL TO 45-50 MPH RIGHT ALONG THE COAST ESPECIALLY WASHINGTON COUNTY. 850-700MB LAPSE RATES OF 6 TO 6.5 C/KM COULD ALLOW FROM STRONG WINDS. KEPT THE ADVISORY UP THROUGH 12 PM FOR THE COAST. LESS WIND AS ONE TRAVELS NORTH TODAY. TURNING COLDER TONIGHT AS THE COLD FRONT SLIDES ACROSS THE REGION AND SHOWERS COME TO AN. DECIDED TO BACK AWAY FROM RAIN CHANGING OVER TO SNOW AS THE BEST FORCING SHIFTS E BY THE LATE EVENING. IT LOOKS LIKE THERE WILL BE SOME PARTIAL CLEARING W/OVERNIGHT LOWS DROPPING BACK INTO THE MID AND UPPER 20S NORTH AND WEST WHILE CENTRAL AND DOWNEAST AREAS WILL SEE LOW TO MID 30S. ANY STANDING WATER WILL RE-FREEZE LATER TONIGHT. BLACK ICE IS A POSSIBILITY BY EARLY WEDNESDAY MORNING. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... DRY WEATHER WITH MODERATING TEMPERATURES. A STRONG 500H RIDGE BUILDS ACROSS THE MIDWEST WITH A DOWNSTREAM TROUGH ACROSS NEW ENGLAND. THE TROUGH MAY BRING SOME HIGH/MID LEVEL CLOUDS AT TIMES WED NIGHT INTO THU, BUT NO PRECIPITATION. AT THE SFC, HIGH PRES CENTERED IN WESTERN QUEBEC AT 12Z WED SLOWLY BUILDS EAST AND IS EXPECTED TO BE JUST WEST OF THE SAINT LAWRENCE RIVER BY 00Z FRI. A STALLED OUT FRONTAL BOUNDARY ACROSS EASTERN NOVA SCOTIA WED MORNING WILL SLOWLY DRIFT TO THE SOUTH AND EAST DURING THE DURATION OF THE SHORT TERM. THE AIR MASS WILL BE SEASONABLE HIGHS MOSTLY IN THE MID 40S NORTH TO THE LOW 50S IN THE GREATER BANGOR REGION. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... FOR MANY, A MUCH AWAITED TASTE OF SPRING. A STRONG 500H RIDGE WITH HEIGHTS IN EXCESS OF 580 DAM BUILDS INTO THE OHIO VALLEY INTO THE UPCOMING WEEKEND AND WEAKENS AND SHIFTS SOUTH EARLY NEXT WEEK. THE ATMOSPHERE WARMS AT ALL LEVELS FRI INTO SAT, AND SAT WILL LIKELY BE THE WARMEST DAY SO FAR THIS SPRING WITH MANY INLAND AREAS TO GET ABOVE 60 DEGREES SATURDAY, BUT IT WILL REMAIN COOLER ALONG AND NEAR THE IMMEDIATE SHORELINE. THE LATEST MODEL CONSENSUS COOLED TEMPS A FEW DEGREES FOR SATURDAY, BUT FOR NOW ELECTED IN COLLABORATION WITH WFO GRAY TO LEAVE THE DAY SHIFTS HIGH TEMPS ALONE. BOTH THE GFS AND ECMWF HAVE A BACKDOOR COLD FRONT THAT DROPS INTO NORTHERN MAINE SUNDAY WITH A SHARPLY COOLER AIR MASS. IT LIKELY REMAINS VERY MILD AHEAD OF THE FRONT ACROSS THE DOWNEAST REGION INTO SUNDAY. MUCH COOLER ACROSS THE CWA MONDAY AS THE FRONT PUSHES SOUTH. TWEAKS THE DEW POINTS TO GO LOWER THAN THE MODEL CONSENSUS LATE WEEK INTO SATURDAY GIVEN THE DRY AIR MASS AND THAT THE MODELS ARE USUALLY TOO HIGH WITH THE DEW POINTS IN THE SPRING PRIOR TO GREEN-UP. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... NEAR TERM: MVFR/IFR TODAY IMPROVING TO VFR BY LATE AFTER W/THE COLD FROPA. LLWS IS A THREAT FOR THE DOWNEAST ESPECIALLY FOR KBHB. VFR FOR TONIGHT. SHORT TERM: VFR EXPECTED WED THROUGH SAT. && .MARINE... NEAR TERM: SCA REMAINS UP THROUGH THIS AFTERNOON. SSW WINDS OF 20 TO 25 KT W/SOME GUSTS TO 35 KT EXPECTED THROUGH LATE MORNING W/THE LLVL JET MENTIONED ABOVE. THE WINDS WILL DROP OFF BELOW SCA BY LATER AFTERNOON INTO THE EVENING AND SHIFT TO THE WNW. SEAS WILL BUILD INTO THE AFTERNOON W/THE LOCAL WAVE MODEL SHOWING 10-12 FT AT THE PEAK EARLY THIS AFTERNOON. A SWELL COMPONENT IS EXPECTED W/A PERIOD OF 10-11 SECONDS. THE SCA COULD BE TRANSITIONED TO HAZARDOUS SEAS AS IT LOOKS AS THOUGH SEAS WILL STAY UP AROUND 6 FT OR SO W/THAT SWELL INTO LATE EVENING. SHORT TERM: THE WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS WED THROUGH FRI. && .FIRE WEATHER... THE ATMOSPHERE WILL WARM AND DRY AT THE END OF THE WEEK INTO THE START OF THE WEEKEND. THE DRIER AIR WILL MIX DOWN THE SFC WITH AFTERNOON RH VALUES AS LOW AS 20 PCT LIKELY LATE THIS WEEK INTO THE FIRST HALF OF THE WEEKEND. A BACKDOOR COLD FRONT WILL BRING MUCH HIGHER RH VALUES TO NORTHERN AREAS SATURDAY AFTERNOON, BUT LOW RH`S WILL LIKELY PERSIST ACROSS CENTRAL AND DOWNEAST AREAS. THE WIND REGIME DOES LOOK TO BE FAIRLY LIGHT, BUT IT MAY GET A LITTLE BREEZY AT TIMES DURING THE AFTERNOON HOURS. && .HYDROLOGY... ADDITIONAL RAINFALL AND THE MILD TEMPERATURES WILL LEAD TO SNOWMELT AND RUNOFF INTO TONIGHT. THERE IS STILL AT LEAST A FOOT OF SNOWPACK IN PLACE ACROSS THE ST. JOHN BASIN IF NOT MORE. THE MELTING OF THE SNOWPACK AIDING IN FURTHER RUNOFF AND INCREASING THE FLOWS, COULD ICE JAMS THAT EXIST UP ON THE ST. JOHN IN THE VICINITY OF ALLAGASH AND ST. JOHN TO DISLODGE AND MOVE DOWNSTREAM. IT NEEDS TO BE NOTED THAT DESPITE THE COOLDOWN, RUNOFF AND SNOWMELT WILL MOST LIKELY CONTINUE INTO LATE WEEK LEADING TO INCREASED RIVER FLOWS. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WIND ADVISORY UNTIL NOON EDT TODAY FOR MEZ029-030. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ050>052. && $$ NEAR TERM...HEWITT SHORT TERM...CB LONG TERM...CB AVIATION...HEWITT/CB MARINE...HEWITT/CB FIRE WEATHER...CB HYDROLOGY...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
358 PM EDT TUE APR 12 2016 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 358 PM EDT TUE APR 12 2016 12Z RAOBS/LATEST RAP ANALYSIS AND WV IMAGERY SHOWS NW FLOW ALF BTWN UP RDG OVER THE ROCKIES AND PERSISTENT UPR TROF OVER ERN NAMERICA. A SHRTWV RDG ACCOMPANIED BY 12HR H5 HGT RISES UP TO 130M/SFC HI PRES IS MOVING INTO THE NW GREAT LKS. WITH DRY LLVL AIR SHOWN ON THE 12Z INL RAOB AND MORE ACYC LLVL FLOW...SC THAT PREVAILED ACRS THE CWA EARLIER IS BREAKING UP W-E AND GIVING WAY TO MOSUNNY SKIES DESPITE SOME LINGERING H85 THERMAL TROFFING. LOOKING UPSTREAM...A SHRTWV IS DIGGING THRU SCENTRAL CANADA AND BRINGING MORE MID/HI CLDS INTO MN. MAIN FCST CONCERNS TNGT INTO WED FOCUS ON POPS/SN AMOUNTS ASSOCIATED WITH SHRTWV NOW MOVING THRU THE NRN PLAINS. SHRTWV OVEF SCENTRAL CANADA IS PROGGED TO SLIDE SE TNGT AND REACH WRN UPR MI/WRN WI BY 12Z WED. DPVA/WAA IN ADVANCE OF THIS DISTURBANCE ARE FCST TO OVERSPREAD THE AREA WNW-ESE TNGT. SINCE THE SHORTER TERM GUIDANCE SHOW SHARPER H85 THERMAL GRADIENT REMAINING OVER WI... SHARPEST ISENTROPIC ASCENT BEST SHOWN ON THE 290K SFC AND H65-7 FGEN ARE FCST TO IMPACT THE WI BORDER COUNTIES OF UPR MI CLOSER TO THE WARM FNT. ALTHOUGH NEARLY 3G/KG SPECIFIC HUMIDITY IS FCST AT H75 ALONG THE WI BORDER...MODEL QPF IS NO MORE THAN ABOUT 0.10-0.15 INCH EVEN ALONG THE BORDER AS DYNAMIC FORCING MUST OVERCOME DRY LLVL AIR MOVING INTO THE CWA THIS AFTN. EVEN IF SN/WATER RATIO REACHES 15:1 WITH RATHER HI DGZ CENTERED BTWN 10-13K FT AGL...EXPECT NO MORE THAN 1-2 INCHES OF SN ACCUM ALONG THE WI BORDER IN THE 06-12Z PERIOD WHEN THE MOST SGNFT FORCING IS FCST. EXPECT THE LOWEST MIN TEMPS TNGT OVER THE E...WHERE CLDS WL BE ABSENT/THINNER FOR A LONGER TIME FARTHER FM THE WARM FNT TO THE SW. FCST POPS WL BE NO HIER THAN SCHC OVER THE FAR NE DEEPER INTO DRY AIR/FARTHER FM WARM FNT. AS THE SHRTWV PASSES TO THE SE ON WED...MID LVL SUBSIDENCE/DRYING IN ITS WAKE WL DIMINISH/END LINGERING PCPN BY THE AFTN...WHICH MAY TEND TO MIX WITH/CHANGE TO RA BEFORE ENDING WITH THE ONSET OF DIURNAL HEATING. BUT MODEL FCST SDNGS SUG A GOOD DEAL OF SC WL LINGER IN PERSISTENT WEAKER WAA PATTERN. BEST CHC FOR MORE CLRG WL BE OVER THE W...WHERE THE LLVL SLY FLOW WL DOWNSLOPE. DESPITE THE LINGERING CLDS...INCRSG SUN ANGLE/DAYTIME HEATING WL LIFT TEMPS INTO THE 40S AND EVEN THE LO 50S OVER THE W AT IWD...WHERE MORE BREAKS ARE LIKELY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 354 PM EDT TUE APR 12 2016 REALLY QUIET IN THE LONG TERM...WHICH STARTS 00Z THU. UPPER RIDGING BUILDS INTO THE AREA INTO THE WEEKEND BEFORE A SHORTWAVE POSSIBLY MOVES THROUGH EARLY NEXT WEEK. NOT LOOKING FOR ANY PRECIP WED NIGHT THROUGH SAT NIGHT...BUT MAY SEE SOME PRECIP SOMETIME SUN INTO EARLY MON AS THE SHORTWAVE PASSES...THEN DRY TUE. MAIN STORY IN THE LONG TERM IS CERTAINLY WARM TEMPS. AWAY FROM THE COOLING INFLUENCE N-NE OF LAKE MICHIGAN...EXPECT HIGHS IN THE MID 50S TO MID 60S THU...THEN 60-70 FRI/SAT/SUN. HIGHS IN THE 40S AND 50S ARE IN THE FORECAST FOR MON AND TUE. WILL BE WATCHING RIVER LEVELS OVER THE NEXT FEW DAYS. RFC ENSEMBLE GUIDANCE SUGGESTS POTENTIAL FOR SOME STREAMS TO RISE TO NEAR ACTION STAGE LATE THIS WEEKEND OR EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 142 PM EDT TUE APR 12 2016 ARRIVAL OF SFC HI PRES/DRY LLVL AIR FM THE W WL RESULT IN VFR CONDITIONS THRU THIS EVNG EVEN THOUGH SOME HIER CLDS WL BE ON THE INCREASE AFTER SUNSET. AN APPROACHING DISTURBANCE SHOULD BRING SOME -SN TO MAINLY THE SW HALF OF UPR MI LATE TNGT...WHEN IWD/SAW MAY SEE MVFR CONDITIONS DEVELOP. SOME OF THESE LO CLDS/MVFR CIGS MAY SPREAD INTO CMX AS WELL AFT 12Z WED...BUT THERE SHOULD BE IMPROVEMENT TO VFR CONDITIONS AT IWD WITH DOWNSLOPING SLY FLOW. THE MVFR CIGS ARE LIKELY TO PERSIST AT SAW THRU 18Z WITH THIS SLY FLOW. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 358 PM EDT TUE APR 12 2016 WITH HI PRES DOMINATING INTO THIS EVENING...EXPECT LIGHT WINDS. AS THE GRADIENT TIGHTENS OVER THE AREA TONIGHT INTO WED ON THE NORTHERN FLANK OF A LO PRES TRACKING THRU THE UPPER MIDWEST...SSE WINDS WILL INCREASE UP TO 20 TO PERHAPS 25 KTS. S WINDS 15-25 KTS WIL THEN DOMINATE THE FORECAST ON THU INTO THE WEEKEND ON THE WESTERN FLANK OF HI PRES SHIFTING INTO THEMID ATLANTIC STATES. AS A COLD FRONT DRIFTS SLOWLY INTO THE UPPER LAKES LATE IN THE WEEKEND...WINDS WILL SHIFT TO THE NE ON SUN. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
355 PM EDT TUE APR 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 508 AM EDT TUE APR 12 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW MID LEVEL TROF SHIFTING E OF THE UPPER GREAT LAKES EARLY THIS MORNING. WITH ASSOCIATED DEEPER MOISTURE ALSO EXITING...LAKE ENHANCED SNOW UNDER 850MB TEMPS OF -10 TO -12C HAS BEEN DIMINISHING FROM W TO E. THERE`S NOT MUCH MORE THAN FLURRIES NOTED OVER W AND NW UPPER MI CURRENTLY. TO THE E...RADAR IMAGERY SHOWS MORE OF A LAKE EFFECT REGIME EXTENDING INTO ALGER/SCHOOLCRAFT AND WRN LUCE COUNTIES. WITH SOME +28DBZ ECHOES STILL NOTED...BRIEF HVY SNOW IS LIKELY OCCURRING. WITH THE OVERWATER INSTABILITY AND FALLING SUBSIDENCE INVERSION OVER THE W UNDER HEIGHT RISES...LAKE EFFECT CLOUDS ARE EXPANDING AND DEVELOPING INTO AN OVC LAYER OVER NEARLY ALL OF THE W HALF OF UPPER MI. UNDER SUBSIDENCE/FALLING INVERSION...EXPECT THE ONGOING LES INTO THE ERN FCST AREA TO DIMINISH RAPIDLY OVER THE NEXT FEW HRS. GIVEN THE STILL ROBUST RADAR RETURNS...SOME LOCATIONS MAY SEE ANOTHER 1-2 INCHES OF SNOW EARLY THIS MORNING...ESPECIALLY FROM AROUND MUNISING TO SHINGLETON INTO SCHOOLCRAFT COUNTY. EXPECT ALL THE FLURRIES/-SHSN OFF LAKE SUPERIOR TO END BY AFTN. WITH 850MB THERMAL TROF RATHER SLOW TO SHIFT E AND WITH LOW-LEVEL MOISTURE ADDED BY LAKE SUPERIOR...EXPECT CONSIDERABLE CLOUD COVER TO LINGER ACROSS THE FCST AREA THRU THE MORNING. CLOUDS WILL THEN THIN OUT SOME DURING THE AFTN. HOWEVER...NEXT SHORTWAVE NOW OVER SRN ALBERTA/SASKATCHEWAN WILL BEGIN TO SPREAD HIGH CLOUDS E INTO THE AREA IN DEVELOPING WAA REGIME. EXPECT MAX TEMPS IN THE 30S TO AROUND 40F...COOLEST N AND E AND WARMEST ALONG THE MI/WI BORDER. AFOREMENTIONED SHORTWAVE SHIFTS TO THE WRN GREAT LAKES TONIGHT. IN RESPONSE...FAIRLY STRONG ISENTROPIC ASCENT SPREADS TOWARD THE AREA PER 290K SFC. BEST FOCUSED ASCENT IS FCST INTO FAR NRN WI AND INTO ADJACENT UPPER MI...AND THAT IS THE AREA WHERE MODELS SHOW GREATEST QPF. ASCENT WILL NEED TO OVERCOME CONSIDERABLE ANTECEDANT DRY AIR PER FCST SOUNDINGS. SO...ALTHOUGH 290K SFC/AROUND 750MB SHOWS MIXING RATIOS OF 3G/KG AVBL...SUGGESTING POTENTIAL OF 3 INCHES OF SNOW PER 6HRS...IT`S NOT LIKELY THAT WILL BE ACHIEVED GIVEN THE DRY AIR THAT NEEDS TO BE OVERCOME. FCST WILL SHOW LIKELY POPS SPREADING INTO THE COUNTIES BORDERING WI OVERNIGHT WITH SNOW ACCUMULATIONS UP TO 1-1.5 INCHES BY 12Z WED. POPS WILL TREND DOWN TO LOW CHC/SCHC TO THE N AND E...AND WILL KEEP THE E DRY OVERNIGHT. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 354 PM EDT TUE APR 12 2016 REALLY QUIET IN THE LONG TERM...WHICH STARTS 00Z THU. UPPER RIDGING BUILDS INTO THE AREA INTO THE WEEKEND BEFORE A SHORTWAVE POSSIBLY MOVES THROUGH EARLY NEXT WEEK. NOT LOOKING FOR ANY PRECIP WED NIGHT THROUGH SAT NIGHT...BUT MAY SEE SOME PRECIP SOMETIME SUN INTO EARLY MON AS THE SHORTWAVE PASSES...THEN DRY TUE. MAIN STORY IN THE LONG TERM IS CERTAINLY WARM TEMPS. AWAY FROM THE COOLING INFLUENCE N-NE OF LAKE MICHIGAN...EXPECT HIGHS IN THE MID 50S TO MID 60S THU...THEN 60-70 FRI/SAT/SUN. HIGHS IN THE 40S AND 50S ARE IN THE FORECAST FOR MON AND TUE. WILL BE WATCHING RIVER LEVELS OVER THE NEXT FEW DAYS. RFC ENSEMBLE GUIDANCE SUGGESTS POTENTIAL FOR SOME STREAMS TO RISE TO NEAR ACTION STAGE LATE THIS WEEKEND OR EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 142 PM EDT TUE APR 12 2016 ARRIVAL OF SFC HI PRES/DRY LLVL AIR FM THE W WL RESULT IN VFR CONDITIONS THRU THIS EVNG EVEN THOUGH SOME HIER CLDS WL BE ON THE INCREASE AFTER SUNSET. AN APPROACHING DISTURBANCE SHOULD BRING SOME -SN TO MAINLY THE SW HALF OF UPR MI LATE TNGT...WHEN IWD/SAW MAY SEE MVFR CONDITIONS DEVELOP. SOME OF THESE LO CLDS/MVFR CIGS MAY SPREAD INTO CMX AS WELL AFT 12Z WED...BUT THERE SHOULD BE IMPROVEMENT TO VFR CONDITIONS AT IWD WITH DOWNSLOPING SLY FLOW. THE MVFR CIGS ARE LIKELY TO PERSIST AT SAW THRU 18Z WITH THIS SLY FLOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 508 AM EDT TUE APR 12 2016 WITH HIGH PRES OVER MN DRIFTING ACROSS LAKE SUPERIOR TODAY...WINDS WILL DIMINISH FROM W TO E...DOWN TO GENERALLY 5-15KT. S TO SE WINDS WILL PREVAIL WED THRU SAT AS A HIGH PRES RIDGE SETS UP TO THE E AND SE AND A LOW PRES TROF SETS UP TO THE NW. OVER WRN LAKE SUPERIOR... ESPECIALLY THE FAR W...WINDS WILL TEND TO BE BACKED MORE TO THE E OR NE AT TIMES. SUSTAINED WIND SPEEDS SHOULD GENERALLY BE UNDER 20KT...BUT THERE WILL BE SOME PERIODS WHERE WINDS GUST UP TO 25KT ACROSS PORTIONS OF CNTRL AND ERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
143 PM EDT TUE APR 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 508 AM EDT TUE APR 12 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW MID LEVEL TROF SHIFTING E OF THE UPPER GREAT LAKES EARLY THIS MORNING. WITH ASSOCIATED DEEPER MOISTURE ALSO EXITING...LAKE ENHANCED SNOW UNDER 850MB TEMPS OF -10 TO -12C HAS BEEN DIMINISHING FROM W TO E. THERE`S NOT MUCH MORE THAN FLURRIES NOTED OVER W AND NW UPPER MI CURRENTLY. TO THE E...RADAR IMAGERY SHOWS MORE OF A LAKE EFFECT REGIME EXTENDING INTO ALGER/SCHOOLCRAFT AND WRN LUCE COUNTIES. WITH SOME +28DBZ ECHOES STILL NOTED...BRIEF HVY SNOW IS LIKELY OCCURRING. WITH THE OVERWATER INSTABILITY AND FALLING SUBSIDENCE INVERSION OVER THE W UNDER HEIGHT RISES...LAKE EFFECT CLOUDS ARE EXPANDING AND DEVELOPING INTO AN OVC LAYER OVER NEARLY ALL OF THE W HALF OF UPPER MI. UNDER SUBSIDENCE/FALLING INVERSION...EXPECT THE ONGOING LES INTO THE ERN FCST AREA TO DIMINISH RAPIDLY OVER THE NEXT FEW HRS. GIVEN THE STILL ROBUST RADAR RETURNS...SOME LOCATIONS MAY SEE ANOTHER 1-2 INCHES OF SNOW EARLY THIS MORNING...ESPECIALLY FROM AROUND MUNISING TO SHINGLETON INTO SCHOOLCRAFT COUNTY. EXPECT ALL THE FLURRIES/-SHSN OFF LAKE SUPERIOR TO END BY AFTN. WITH 850MB THERMAL TROF RATHER SLOW TO SHIFT E AND WITH LOW-LEVEL MOISTURE ADDED BY LAKE SUPERIOR...EXPECT CONSIDERABLE CLOUD COVER TO LINGER ACROSS THE FCST AREA THRU THE MORNING. CLOUDS WILL THEN THIN OUT SOME DURING THE AFTN. HOWEVER...NEXT SHORTWAVE NOW OVER SRN ALBERTA/SASKATCHEWAN WILL BEGIN TO SPREAD HIGH CLOUDS E INTO THE AREA IN DEVELOPING WAA REGIME. EXPECT MAX TEMPS IN THE 30S TO AROUND 40F...COOLEST N AND E AND WARMEST ALONG THE MI/WI BORDER. AFOREMENTIONED SHORTWAVE SHIFTS TO THE WRN GREAT LAKES TONIGHT. IN RESPONSE...FAIRLY STRONG ISENTROPIC ASCENT SPREADS TOWARD THE AREA PER 290K SFC. BEST FOCUSED ASCENT IS FCST INTO FAR NRN WI AND INTO ADJACENT UPPER MI...AND THAT IS THE AREA WHERE MODELS SHOW GREATEST QPF. ASCENT WILL NEED TO OVERCOME CONSIDERABLE ANTECEDANT DRY AIR PER FCST SOUNDINGS. SO...ALTHOUGH 290K SFC/AROUND 750MB SHOWS MIXING RATIOS OF 3G/KG AVBL...SUGGESTING POTENTIAL OF 3 INCHES OF SNOW PER 6HRS...IT`S NOT LIKELY THAT WILL BE ACHIEVED GIVEN THE DRY AIR THAT NEEDS TO BE OVERCOME. FCST WILL SHOW LIKELY POPS SPREADING INTO THE COUNTIES BORDERING WI OVERNIGHT WITH SNOW ACCUMULATIONS UP TO 1-1.5 INCHES BY 12Z WED. POPS WILL TREND DOWN TO LOW CHC/SCHC TO THE N AND E...AND WILL KEEP THE E DRY OVERNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 412 AM EDT TUE APR 12 2016 SPLIT FLOW PATTERN IS IN PLACE ACROSS NORTH AMERICA. NORTHERN STREAM POLAR BRANCH WILL AFFECT GREAT LAKES THROUGH WED...THEN STRONG JET FM JAPAN ACROSS THE NORTHERN PACIFIC THAT IS CURRENTLY SURGING TOWARD WESTERN CONUS COAST WILL PUSH RIDGING ACROSS THE CENTRAL AND EASTERN CONUS BY LATE THIS WEEK WHILE TROUGH MOVES OVER MUCH OF WESTERN CONUS. ARRIVAL OF RIDGE WILL BRING SIGNIFICANTLY WARMER AND ALSO DRIER CONDITIONS TO THE UPPER GREAT LAKES LATE THIS WEEK INTO THE WEEKEND. EVENTUALLY TROUGHING ALOFT OVER WESTERN CONUS WILL SPLIT AND NORTHERN PORTION OF THE TROUGH WILL TRY TO FLATTEN RIDGE OVER UPPER GREAT LAKES LATE IN THE WEEKEND WITH WEAK SFC TROUGH CROSSING THE AREA. COULD SEE SOME RAIN SHOWERS ONCE THE TROUGH MOVES THROUGH SUN NIGHT INTO MON. ONE LAST SHORTWAVE WORKS ACROSS UPPER GREAT LAKES ON WED MORNING AS LARGE SCALE TROUGH OVER EASTERN CANADA/GREAT LAKES SLIDES EAST. PVA FM SHORTWAVE AND WARM AIR ADVECTION/H85-H7 FRONTOGENESIS TIED TO LEFT EXIT OF JET STREAK MANITOBA TO NORTHERN MN/WESTERN LK SUPERIOR WILL BRING LIGHT SNOW INTO CNTRL CWA ON WED MORNING. WARM AIR ADVECTION DIMINISHES HEADING INTO EASTERN CWA AND DRY AIR IS MOST RESILIENT THERE...SO EXPECT POPS TO DIMINISH FM CENTRAL TO EAST CWA ON WED MORNING. SNOW PROBABLY TAPERS OFF AS A MIX OF RAIN/SNOW OR JUST RAIN ON WED OVER THE WEST HALF. BEST CHANCE FOR ADDITIONAL ACCUMULATING SNOW ON WED...MAYBE UP TO 1 INCH...IS OVER SOUTHWEST CWA. ONCE THE PRECIP EXITS...WARMER AIR BEGINS TO MAKE IT TO SFC WITH HIGHS ON WED AFTN TOPPING OUT AROUND 50 DEGREES FAR WEST AND INTO THE 40S ELSEWHERE. SFC RIDGE EXTENDING INTO EASTERN CWA WILL ALLOW INTERIOR EAST TO SEE MINS DROPPING INTO THE MID-UPR 20S ON WED NIGHT. TIGHTER GRADIENT WITH INCREASING SOUTH WINDS SHOULD KEEP TEMPS OVER FAR WEST FM DROPPING MUCH BLO 40 DEGREES. MUCH WARMER AND ALSO DRY CONDITIONS REST OF THE WEEK INTO NEXT WEEKEND WILL ALLOW SNOW PACK TO DIMINISH SIGNIFICANTLY...AND IN SOME PLACES TO COMPLETELY DISAPPEAR. WITH EXPECTATION OF PLENTY OF SUNSHINE AND DRY/DEEPLY MIXED AIR MASS...CONTINUED TO INCREASE MAX TEMPS THU-SUN OVER CONSENSUS AND LOWER AFTN TD/RH. PEAK OF WARMTH LOOKS TO OCCUR FRI/SAT /MAXES NEARING 70 OVER THE WEST/ AND POSSIBLY SUN...AT LEAST FOR CENTRAL AND EAST CWA AHEAD OF FRONT BEGINNING TO MOVE INTO THE AREA. EVEN WITH TEMPS THIS WARM DURING THE DAYS THE SNOWMELT COULD END UP MORE GRADUAL WITH DRY AIRMASS AND AS TEMPS AT LEAST INLAND FALL BACK INTO THE 30S. BROUGHT LOW CHANCES FOR RAIN SHOWERS BACK INTO THE FORECAST SUN NIGHT INTO MONDAY AS THE FRONT CROSSES UPR MICHIGAN. WINDS TURNING NE OFF LK SUPERIOR BEHIND THE FRONT COULD LEAD TO SHARPLY COOLER TEMPS OVER THE NORTHERN U.P. COMPARED TO THU-SUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 142 PM EDT TUE APR 12 2016 ARRIVAL OF SFC HI PRES/DRY LLVL AIR FM THE W WL RESULT IN VFR CONDITIONS THRU THIS EVNG EVEN THOUGH SOME HIER CLDS WL BE ON THE INCREASE AFTER SUNSET. AN APPROACHING DISTURBANCE SHOULD BRING SOME -SN TO MAINLY THE SW HALF OF UPR MI LATE TNGT...WHEN IWD/SAW MAY SEE MVFR CONDITIONS DEVELOP. SOME OF THESE LO CLDS/MVFR CIGS MAY SPREAD INTO CMX AS WELL AFT 12Z WED...BUT THERE SHOULD BE IMPROVEMENT TO VFR CONDITIONS AT IWD WITH DOWNSLOPING SLY FLOW. THE MVFR CIGS ARE LIKELY TO PERSIST AT SAW THRU 18Z WITH THIS SLY FLOW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 508 AM EDT TUE APR 12 2016 WITH HIGH PRES OVER MN DRIFTING ACROSS LAKE SUPERIOR TODAY...WINDS WILL DIMINISH FROM W TO E...DOWN TO GENERALLY 5-15KT. S TO SE WINDS WILL PREVAIL WED THRU SAT AS A HIGH PRES RIDGE SETS UP TO THE E AND SE AND A LOW PRES TROF SETS UP TO THE NW. OVER WRN LAKE SUPERIOR... ESPECIALLY THE FAR W...WINDS WILL TEND TO BE BACKED MORE TO THE E OR NE AT TIMES. SUSTAINED WIND SPEEDS SHOULD GENERALLY BE UNDER 20KT...BUT THERE WILL BE SOME PERIODS WHERE WINDS GUST UP TO 25KT ACROSS PORTIONS OF CNTRL AND ERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...KC MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
726 AM EDT TUE APR 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 508 AM EDT TUE APR 12 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW MID LEVEL TROF SHIFTING E OF THE UPPER GREAT LAKES EARLY THIS MORNING. WITH ASSOCIATED DEEPER MOISTURE ALSO EXITING...LAKE ENHANCED SNOW UNDER 850MB TEMPS OF -10 TO -12C HAS BEEN DIMINISHING FROM W TO E. THERE`S NOT MUCH MORE THAN FLURRIES NOTED OVER W AND NW UPPER MI CURRENTLY. TO THE E...RADAR IMAGERY SHOWS MORE OF A LAKE EFFECT REGIME EXTENDING INTO ALGER/SCHOOLCRAFT AND WRN LUCE COUNTIES. WITH SOME +28DBZ ECHOES STILL NOTED...BRIEF HVY SNOW IS LIKELY OCCURRING. WITH THE OVERWATER INSTABILITY AND FALLING SUBSIDENCE INVERSION OVER THE W UNDER HEIGHT RISES...LAKE EFFECT CLOUDS ARE EXPANDING AND DEVELOPING INTO AN OVC LAYER OVER NEARLY ALL OF THE W HALF OF UPPER MI. UNDER SUBSIDENCE/FALLING INVERSION...EXPECT THE ONGOING LES INTO THE ERN FCST AREA TO DIMINISH RAPIDLY OVER THE NEXT FEW HRS. GIVEN THE STILL ROBUST RADAR RETURNS...SOME LOCATIONS MAY SEE ANOTHER 1-2 INCHES OF SNOW EARLY THIS MORNING...ESPECIALLY FROM AROUND MUNISING TO SHINGLETON INTO SCHOOLCRAFT COUNTY. EXPECT ALL THE FLURRIES/-SHSN OFF LAKE SUPERIOR TO END BY AFTN. WITH 850MB THERMAL TROF RATHER SLOW TO SHIFT E AND WITH LOW-LEVEL MOISTURE ADDED BY LAKE SUPERIOR...EXPECT CONSIDERABLE CLOUD COVER TO LINGER ACROSS THE FCST AREA THRU THE MORNING. CLOUDS WILL THEN THIN OUT SOME DURING THE AFTN. HOWEVER...NEXT SHORTWAVE NOW OVER SRN ALBERTA/SASKATCHEWAN WILL BEGIN TO SPREAD HIGH CLOUDS E INTO THE AREA IN DEVELOPING WAA REGIME. EXPECT MAX TEMPS IN THE 30S TO AROUND 40F...COOLEST N AND E AND WARMEST ALONG THE MI/WI BORDER. AFOREMENTIONED SHORTWAVE SHIFTS TO THE WRN GREAT LAKES TONIGHT. IN RESPONSE...FAIRLY STRONG ISENTROPIC ASCENT SPREADS TOWARD THE AREA PER 290K SFC. BEST FOCUSED ASCENT IS FCST INTO FAR NRN WI AND INTO ADJACENT UPPER MI...AND THAT IS THE AREA WHERE MODELS SHOW GREATEST QPF. ASCENT WILL NEED TO OVERCOME CONSIDERABLE ANTECEDANT DRY AIR PER FCST SOUNDINGS. SO...ALTHOUGH 290K SFC/AROUND 750MB SHOWS MIXING RATIOS OF 3G/KG AVBL...SUGGESTING POTENTIAL OF 3 INCHES OF SNOW PER 6HRS...IT`S NOT LIKELY THAT WILL BE ACHIEVED GIVEN THE DRY AIR THAT NEEDS TO BE OVERCOME. FCST WILL SHOW LIKELY POPS SPREADING INTO THE COUNTIES BORDERING WI OVERNIGHT WITH SNOW ACCUMULATIONS UP TO 1-1.5 INCHES BY 12Z WED. POPS WILL TREND DOWN TO LOW CHC/SCHC TO THE N AND E...AND WILL KEEP THE E DRY OVERNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 412 AM EDT TUE APR 12 2016 SPLIT FLOW PATTERN IS IN PLACE ACROSS NORTH AMERICA. NORTHERN STREAM POLAR BRANCH WILL AFFECT GREAT LAKES THROUGH WED...THEN STRONG JET FM JAPAN ACROSS THE NORTHERN PACIFIC THAT IS CURRENTLY SURGING TOWARD WESTERN CONUS COAST WILL PUSH RIDGING ACROSS THE CENTRAL AND EASTERN CONUS BY LATE THIS WEEK WHILE TROUGH MOVES OVER MUCH OF WESTERN CONUS. ARRIVAL OF RIDGE WILL BRING SIGNIFICANTLY WARMER AND ALSO DRIER CONDITIONS TO THE UPPER GREAT LAKES LATE THIS WEEK INTO THE WEEKEND. EVENTUALLY TROUGHING ALOFT OVER WESTERN CONUS WILL SPLIT AND NORTHERN PORTION OF THE TROUGH WILL TRY TO FLATTEN RIDGE OVER UPPER GREAT LAKES LATE IN THE WEEKEND WITH WEAK SFC TROUGH CROSSING THE AREA. COULD SEE SOME RAIN SHOWERS ONCE THE TROUGH MOVES THROUGH SUN NIGHT INTO MON. ONE LAST SHORTWAVE WORKS ACROSS UPPER GREAT LAKES ON WED MORNING AS LARGE SCALE TROUGH OVER EASTERN CANADA/GREAT LAKES SLIDES EAST. PVA FM SHORTWAVE AND WARM AIR ADVECTION/H85-H7 FRONTOGENESIS TIED TO LEFT EXIT OF JET STREAK MANITOBA TO NORTHERN MN/WESTERN LK SUPERIOR WILL BRING LIGHT SNOW INTO CNTRL CWA ON WED MORNING. WARM AIR ADVECTION DIMINISHES HEADING INTO EASTERN CWA AND DRY AIR IS MOST RESILIENT THERE...SO EXPECT POPS TO DIMINISH FM CENTRAL TO EAST CWA ON WED MORNING. SNOW PROBABLY TAPERS OFF AS A MIX OF RAIN/SNOW OR JUST RAIN ON WED OVER THE WEST HALF. BEST CHANCE FOR ADDITIONAL ACCUMULATING SNOW ON WED...MAYBE UP TO 1 INCH...IS OVER SOUTHWEST CWA. ONCE THE PRECIP EXITS...WARMER AIR BEGINS TO MAKE IT TO SFC WITH HIGHS ON WED AFTN TOPPING OUT AROUND 50 DEGREES FAR WEST AND INTO THE 40S ELSEWHERE. SFC RIDGE EXTENDING INTO EASTERN CWA WILL ALLOW INTERIOR EAST TO SEE MINS DROPPING INTO THE MID-UPR 20S ON WED NIGHT. TIGHTER GRADIENT WITH INCREASING SOUTH WINDS SHOULD KEEP TEMPS OVER FAR WEST FM DROPPING MUCH BLO 40 DEGREES. MUCH WARMER AND ALSO DRY CONDITIONS REST OF THE WEEK INTO NEXT WEEKEND WILL ALLOW SNOW PACK TO DIMINISH SIGNIFICANTLY...AND IN SOME PLACES TO COMPLETELY DISAPPEAR. WITH EXPECTATION OF PLENTY OF SUNSHINE AND DRY/DEEPLY MIXED AIR MASS...CONTINUED TO INCREASE MAX TEMPS THU-SUN OVER CONSENSUS AND LOWER AFTN TD/RH. PEAK OF WARMTH LOOKS TO OCCUR FRI/SAT /MAXES NEARING 70 OVER THE WEST/ AND POSSIBLY SUN...AT LEAST FOR CENTRAL AND EAST CWA AHEAD OF FRONT BEGINNING TO MOVE INTO THE AREA. EVEN WITH TEMPS THIS WARM DURING THE DAYS THE SNOWMELT COULD END UP MORE GRADUAL WITH DRY AIRMASS AND AS TEMPS AT LEAST INLAND FALL BACK INTO THE 30S. BROUGHT LOW CHANCES FOR RAIN SHOWERS BACK INTO THE FORECAST SUN NIGHT INTO MONDAY AS THE FRONT CROSSES UPR MICHIGAN. WINDS TURNING NE OFF LK SUPERIOR BEHIND THE FRONT COULD LEAD TO SHARPLY COOLER TEMPS OVER THE NORTHERN U.P. COMPARED TO THU-SUN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 726 AM EDT TUE APR 12 2016 AHEAD OF APPROACHING HIGH PRES...FALLING SUBSIDENCE INVERSION AND LOW-LEVEL MOISTURE OFF LAKE SUPERIOR SHOULD LEAD TO PREVAILING MVFR CIGS THIS MORNING AT KIWD/KCMX/KSAW. EXPECT IMPROVEMENT TO VFR FROM W TO E THIS AFTN AS SFC HIGH PRES RIDGE PASSES AND LOW CLOUDS SCATTER OUT. VFR CONDITIONS WILL CONTINUE INTO THE EVENING HRS. AN APPROACHING DISTURBANCE SHOULD BRING SOME -SN TO THE AREA OVERNIGHT...AND KIWD/KSAW MAY SEE MVFR CONDITIONS DEVELOP. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 508 AM EDT TUE APR 12 2016 WITH HIGH PRES OVER MN DRIFTING ACROSS LAKE SUPERIOR TODAY...WINDS WILL DIMINISH FROM W TO E...DOWN TO GENERALLY 5-15KT. S TO SE WINDS WILL PREVAIL WED THRU SAT AS A HIGH PRES RIDGE SETS UP TO THE E AND SE AND A LOW PRES TROF SETS UP TO THE NW. OVER WRN LAKE SUPERIOR... ESPECIALLY THE FAR W...WINDS WILL TEND TO BE BACKED MORE TO THE E OR NE AT TIMES. SUSTAINED WIND SPEEDS SHOULD GENERALLY BE UNDER 20KT...BUT THERE WILL BE SOME PERIODS WHERE WINDS GUST UP TO 25KT ACROSS PORTIONS OF CNTRL AND ERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
508 AM EDT TUE APR 12 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 508 AM EDT TUE APR 12 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW MID LEVEL TROF SHIFTING E OF THE UPPER GREAT LAKES EARLY THIS MORNING. WITH ASSOCIATED DEEPER MOISTURE ALSO EXITING...LAKE ENHANCED SNOW UNDER 850MB TEMPS OF -10 TO -12C HAS BEEN DIMINISHING FROM W TO E. THERE`S NOT MUCH MORE THAN FLURRIES NOTED OVER W AND NW UPPER MI CURRENTLY. TO THE E...RADAR IMAGERY SHOWS MORE OF A LAKE EFFECT REGIME EXTENDING INTO ALGER/SCHOOLCRAFT AND WRN LUCE COUNTIES. WITH SOME +28DBZ ECHOES STILL NOTED...BRIEF HVY SNOW IS LIKELY OCCURRING. WITH THE OVERWATER INSTABILITY AND FALLING SUBSIDENCE INVERSION OVER THE W UNDER HEIGHT RISES...LAKE EFFECT CLOUDS ARE EXPANDING AND DEVELOPING INTO AN OVC LAYER OVER NEARLY ALL OF THE W HALF OF UPPER MI. UNDER SUBSIDENCE/FALLING INVERSION...EXPECT THE ONGOING LES INTO THE ERN FCST AREA TO DIMINISH RAPIDLY OVER THE NEXT FEW HRS. GIVEN THE STILL ROBUST RADAR RETURNS...SOME LOCATIONS MAY SEE ANOTHER 1-2 INCHES OF SNOW EARLY THIS MORNING...ESPECIALLY FROM AROUND MUNISING TO SHINGLETON INTO SCHOOLCRAFT COUNTY. EXPECT ALL THE FLURRIES/-SHSN OFF LAKE SUPERIOR TO END BY AFTN. WITH 850MB THERMAL TROF RATHER SLOW TO SHIFT E AND WITH LOW-LEVEL MOISTURE ADDED BY LAKE SUPERIOR...EXPECT CONSIDERABLE CLOUD COVER TO LINGER ACROSS THE FCST AREA THRU THE MORNING. CLOUDS WILL THEN THIN OUT SOME DURING THE AFTN. HOWEVER...NEXT SHORTWAVE NOW OVER SRN ALBERTA/SASKATCHEWAN WILL BEGIN TO SPREAD HIGH CLOUDS E INTO THE AREA IN DEVELOPING WAA REGIME. EXPECT MAX TEMPS IN THE 30S TO AROUND 40F...COOLEST N AND E AND WARMEST ALONG THE MI/WI BORDER. AFOREMENTIONED SHORTWAVE SHIFTS TO THE WRN GREAT LAKES TONIGHT. IN RESPONSE...FAIRLY STRONG ISENTROPIC ASCENT SPREADS TOWARD THE AREA PER 290K SFC. BEST FOCUSED ASCENT IS FCST INTO FAR NRN WI AND INTO ADJACENT UPPER MI...AND THAT IS THE AREA WHERE MODELS SHOW GREATEST QPF. ASCENT WILL NEED TO OVERCOME CONSIDERABLE ANTECEDANT DRY AIR PER FCST SOUNDINGS. SO...ALTHOUGH 290K SFC/AROUND 750MB SHOWS MIXING RATIOS OF 3G/KG AVBL...SUGGESTING POTENTIAL OF 3 INCHES OF SNOW PER 6HRS...IT`S NOT LIKELY THAT WILL BE ACHIEVED GIVEN THE DRY AIR THAT NEEDS TO BE OVERCOME. FCST WILL SHOW LIKELY POPS SPREADING INTO THE COUNTIES BORDERING WI OVERNIGHT WITH SNOW ACCUMULATIONS UP TO 1-1.5 INCHES BY 12Z WED. POPS WILL TREND DOWN TO LOW CHC/SCHC TO THE N AND E...AND WILL KEEP THE E DRY OVERNIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 412 AM EDT TUE APR 12 2016 SPLIT FLOW PATTERN IS IN PLACE ACROSS NORTH AMERICA. NORTHERN STREAM POLAR BRANCH WILL AFFECT GREAT LAKES THROUGH WED...THEN STRONG JET FM JAPAN ACROSS THE NORTHERN PACIFIC THAT IS CURRENTLY SURGING TOWARD WESTERN CONUS COAST WILL PUSH RIDGING ACROSS THE CENTRAL AND EASTERN CONUS BY LATE THIS WEEK WHILE TROUGH MOVES OVER MUCH OF WESTERN CONUS. ARRIVAL OF RIDGE WILL BRING SIGNIFICANTLY WARMER AND ALSO DRIER CONDITIONS TO THE UPPER GREAT LAKES LATE THIS WEEK INTO THE WEEKEND. EVENTUALLY TROUGHING ALOFT OVER WESTERN CONUS WILL SPLIT AND NORTHERN PORTION OF THE TROUGH WILL TRY TO FLATTEN RIDGE OVER UPPER GREAT LAKES LATE IN THE WEEKEND WITH WEAK SFC TROUGH CROSSING THE AREA. COULD SEE SOME RAIN SHOWERS ONCE THE TROUGH MOVES THROUGH SUN NIGHT INTO MON. ONE LAST SHORTWAVE WORKS ACROSS UPPER GREAT LAKES ON WED MORNING AS LARGE SCALE TROUGH OVER EASTERN CANADA/GREAT LAKES SLIDES EAST. PVA FM SHORTWAVE AND WARM AIR ADVECTION/H85-H7 FRONTOGENESIS TIED TO LEFT EXIT OF JET STREAK MANITOBA TO NORTHERN MN/WESTERN LK SUPERIOR WILL BRING LIGHT SNOW INTO CNTRL CWA ON WED MORNING. WARM AIR ADVECTION DIMINISHES HEADING INTO EASTERN CWA AND DRY AIR IS MOST RESILIENT THERE...SO EXPECT POPS TO DIMINISH FM CENTRAL TO EAST CWA ON WED MORNING. SNOW PROBABLY TAPERS OFF AS A MIX OF RAIN/SNOW OR JUST RAIN ON WED OVER THE WEST HALF. BEST CHANCE FOR ADDITIONAL ACCUMULATING SNOW ON WED...MAYBE UP TO 1 INCH...IS OVER SOUTHWEST CWA. ONCE THE PRECIP EXITS...WARMER AIR BEGINS TO MAKE IT TO SFC WITH HIGHS ON WED AFTN TOPPING OUT AROUND 50 DEGREES FAR WEST AND INTO THE 40S ELSEWHERE. SFC RIDGE EXTENDING INTO EASTERN CWA WILL ALLOW INTERIOR EAST TO SEE MINS DROPPING INTO THE MID-UPR 20S ON WED NIGHT. TIGHTER GRADIENT WITH INCREASING SOUTH WINDS SHOULD KEEP TEMPS OVER FAR WEST FM DROPPING MUCH BLO 40 DEGREES. MUCH WARMER AND ALSO DRY CONDITIONS REST OF THE WEEK INTO NEXT WEEKEND WILL ALLOW SNOW PACK TO DIMINISH SIGNIFICANTLY...AND IN SOME PLACES TO COMPLETELY DISAPPEAR. WITH EXPECTATION OF PLENTY OF SUNSHINE AND DRY/DEEPLY MIXED AIR MASS...CONTINUED TO INCREASE MAX TEMPS THU-SUN OVER CONSENSUS AND LOWER AFTN TD/RH. PEAK OF WARMTH LOOKS TO OCCUR FRI/SAT /MAXES NEARING 70 OVER THE WEST/ AND POSSIBLY SUN...AT LEAST FOR CENTRAL AND EAST CWA AHEAD OF FRONT BEGINNING TO MOVE INTO THE AREA. EVEN WITH TEMPS THIS WARM DURING THE DAYS THE SNOWMELT COULD END UP MORE GRADUAL WITH DRY AIRMASS AND AS TEMPS AT LEAST INLAND FALL BACK INTO THE 30S. BROUGHT LOW CHANCES FOR RAIN SHOWERS BACK INTO THE FORECAST SUN NIGHT INTO MONDAY AS THE FRONT CROSSES UPR MICHIGAN. WINDS TURNING NE OFF LK SUPERIOR BEHIND THE FRONT COULD LEAD TO SHARPLY COOLER TEMPS OVER THE NORTHERN U.P. COMPARED TO THU-SUN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 124 AM EDT TUE APR 12 2016 AS THE TROUGH AND AREA OF STRONGER LOW LEVEL CONVERGENCE SLIDES OFF TO THE SOUTHEAST OVERNIGHT...EXPECT THE REMAINING SNOW SHOWERS TO DIMINISH WITH VFR VSBY PREVAILING OVERNIGHT. HOWEVER...ENOUGH LOW LEVEL MOISTURE WILL LINGER FOR CIGS NEAR OR SLIGHTLY BELOW MVFR THRESHOLD INTO MID MORNING AT CMX AND IWD. UPSLOPE NE FLOW INTO SAW WILL MORE LIKELY SUSTAIN MVFR CIGS THROUGH MOST OF THE DAY UNTIL WINDS VEER TO THE SE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 508 AM EDT TUE APR 12 2016 WITH HIGH PRES OVER MN DRIFTING ACROSS LAKE SUPERIOR TODAY...WINDS WILL DIMINISH FROM W TO E...DOWN TO GENERALLY 5-15KT. S TO SE WINDS WILL PREVAIL WED THRU SAT AS A HIGH PRES RIDGE SETS UP TO THE E AND SE AND A LOW PRES TROF SETS UP TO THE NW. OVER WRN LAKE SUPERIOR... ESPECIALLY THE FAR W...WINDS WILL TEND TO BE BACKED MORE TO THE E OR NE AT TIMES. SUSTAINED WIND SPEEDS SHOULD GENERALLY BE UNDER 20KT...BUT THERE WILL BE SOME PERIODS WHERE WINDS GUST UP TO 25KT ACROSS PORTIONS OF CNTRL AND ERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...JLA AVIATION...JLB MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
419 AM EDT TUE APR 12 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 357 PM EDT MON APR 11 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A MID-LVL TROUGH EXTENDING FROM HUDSON BAY INTO THE UPPER GREAT LAKES AND UPPER MISSISSIPPI VALLEY. AT SFC...A LOW WAS CENTERED IN ONTARIO NE OF LAKE SUPERIOR WITH A TROUGH EXTENDING INTO NRN AND WRN LAKE SUPERIOR. DEEPER MOISTURE/CYCLONIC FLOW AND FORCING/INSTABILITY ASSOC WITH THE MID- LVL TROF MOVING OVER THE AREA HAS GENERATED SCT TO NUMEROUS SHSN ACROSS MUCH OF THE FCST AREA TODAY. WITH 850MB TEMPS AROUND -10C AND MODEST DEEP LAYER FORCING...EXPECT LAKE ENHANCED SNOW TO CONTINUE INTO EARLY EVENING INTO THE WRN FCST AREA...ESPECIALLY THE NW...JUST AHEAD OF APPROACHING SFC TROF. UPSLOPING WILL FURTHER ENHANCE PCPN. USING A BLEND OF SOME OF THE NCEP HIGH RES GUIDANCE (ARW/NMM/NAM WINDOW)...REG CANADIAN QPF AND LATEST RAP/HRRR RUNS SUGGESTS A POTENTIAL FOR POSSIBLE ADVY SNOWS ACROSS PORTIONS OF THE HIGH TERRAIN OF NW UPPER MI WITH QPF AMOUNTS OF 0.2 TO AS MUCH AS 0.35 INCHES THIS AFTERNOON INTO THIS EVENING. A FEW LOCATIONS FROM KEWEENAW PENINSULA INTO THE HURON MOUNTAINS REGION (ERN BARAGA/NW MQT COUNTIES) COULD SEE ANYWHERE FROM 3-5 INCHES OF SNOW. HOWEVER...GIVEN THAT SOME OF THIS SNOW WILL BE OCCURRING STILL THIS AFTERNOON AND MELTING ON ROADS FROM HIGHER APRIL SUN ANGLE WORKING THRU CLOUDS...WL PROBABLY HOLD OFF ON ADVISORY. MAY CONSIDER ISSUING A SPS FOR KEWEENAW-HOUGHTON-BARAGA AND MQT COUNTIES FOR SOME SLUSHY SNOW ACCUMULATION IN FAVORED NW FACING HIGHER TERRAIN. AWAY FROM NW UPPER MI...EXPECT ISOLD/SCT - SHSN/FLURRIES TO CONTINUE INTO THIS EVENING FROM LINGERING DAYTIME INSTABILITY. COULD SEE NUMEROUS LAKE ENHANCED SHSN DEVELOP TOWARD EVENING OVER ERN COUNTIES AS WINDS COME AROUND MORE NW WITH FRONTAL PASSAGE...ALTHOUGH WEAKER INSTABILITY SHOULD LIMIT ACCUMULATION THERE TO NO MORE THAN INCH OR TWO. IN ADDITION...EXPECT BLUSTERY NW WINDS TO 25-30 KT TO CONTINUE INTO EARLY EVENING...PERHAPS A BIT HIGHER OVER EXPOSED TERRAIN OF KEWEENAW. AS MID-LVL TROUGH SHIFTS EAST LATE EVENING/OVERNIGHT AND Q-VECT DIV/DRIER AIR SPREADS IN FROM WEST AHEAD OF BUILDING RDG....EXPECT SHSN TO TAPER OFF OR END FM WEST OVERNIGHT. TUE...LOWERING INVERSIONS TO 4KFT AND SHARP DRYING BLO INVERSION SHOULD QUICKLY END ANY LINGERING NW FLOW LES OVER ERN COUNTIES. KEPT WITH CHANCE POPS OVER NCNTRL AND EAST CWA IN THE MORNING...THEN DROP TO SLIGHT CHANCES IN THE EARLY AFTN. ARRIVAL OF SFC RIDGE BRINGS WINDS TO SW OVER WEST HALF IN THE AFTN. LOW-LEVEL MOISTURE STAYS MAINLY TRAPPED BENEATH THE RIDGE...SO SKIES SHOULD REMAIN MOSTLY CLOUDY THROUGH THE DAY. TEMPS STAY ON THE COOLER SIDE OF NORMAL AS H85 THERMAL TROUGH ROTATES THROUGH. HIGHS IN THE LOW 30S NEAR LK SUPERIOR AND TO LOWER 40S FAR WEST AND ALONG WI BORDER ARE EXPECTED. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 412 AM EDT TUE APR 12 2016 SPLIT FLOW PATTERN IS IN PLACE ACROSS NORTH AMERICA. NORTHERN STREAM POLAR BRANCH WILL AFFECT GREAT LAKES THROUGH WED...THEN STRONG JET FM JAPAN ACROSS THE NORTHERN PACIFIC THAT IS CURRENTLY SURGING TOWARD WESTERN CONUS COAST WILL PUSH RIDGING ACROSS THE CENTRAL AND EASTERN CONUS BY LATE THIS WEEK WHILE TROUGH MOVES OVER MUCH OF WESTERN CONUS. ARRIVAL OF RIDGE WILL BRING SIGNIFICANTLY WARMER AND ALSO DRIER CONDITIONS TO THE UPPER GREAT LAKES LATE THIS WEEK INTO THE WEEKEND. EVENTUALLY TROUGHING ALOFT OVER WESTERN CONUS WILL SPLIT AND NORTHERN PORTION OF THE TROUGH WILL TRY TO FLATTEN RIDGE OVER UPPER GREAT LAKES LATE IN THE WEEKEND WITH WEAK SFC TROUGH CROSSING THE AREA. COULD SEE SOME RAIN SHOWERS ONCE THE TROUGH MOVES THROUGH SUN NIGHT INTO MON. ONE LAST SHORTWAVE WORKS ACROSS UPPER GREAT LAKES ON WED MORNING AS LARGE SCALE TROUGH OVER EASTERN CANADA/GREAT LAKES SLIDES EAST. PVA FM SHORTWAVE AND WARM AIR ADVECTION/H85-H7 FRONTOGENESIS TIED TO LEFT EXIT OF JET STREAK MANITOBA TO NORTHERN MN/WESTERN LK SUPERIOR WILL BRING LIGHT SNOW INTO CNTRL CWA ON WED MORNING. WARM AIR ADVECTION DIMINISHES HEADING INTO EASTERN CWA AND DRY AIR IS MOST RESILIENT THERE...SO EXPECT POPS TO DIMINISH FM CENTRAL TO EAST CWA ON WED MORNING. SNOW PROBABLY TAPERS OFF AS A MIX OF RAIN/SNOW OR JUST RAIN ON WED OVER THE WEST HALF. BEST CHANCE FOR ADDITIONAL ACCUMULATING SNOW ON WED...MAYBE UP TO 1 INCH...IS OVER SOUTHWEST CWA. ONCE THE PRECIP EXITS...WARMER AIR BEGINS TO MAKE IT TO SFC WITH HIGHS ON WED AFTN TOPPING OUT AROUND 50 DEGREES FAR WEST AND INTO THE 40S ELSEWHERE. SFC RIDGE EXTENDING INTO EASTERN CWA WILL ALLOW INTERIOR EAST TO SEE MINS DROPPING INTO THE MID-UPR 20S ON WED NIGHT. TIGHTER GRADIENT WITH INCREASING SOUTH WINDS SHOULD KEEP TEMPS OVER FAR WEST FM DROPPING MUCH BLO 40 DEGREES. MUCH WARMER AND ALSO DRY CONDITIONS REST OF THE WEEK INTO NEXT WEEKEND WILL ALLOW SNOW PACK TO DIMINISH SIGNIFICANTLY...AND IN SOME PLACES TO COMPLETELY DISAPPEAR. WITH EXPECTATION OF PLENTY OF SUNSHINE AND DRY/DEEPLY MIXED AIR MASS...CONTINUED TO INCREASE MAX TEMPS THU-SUN OVER CONSENSUS AND LOWER AFTN TD/RH. PEAK OF WARMTH LOOKS TO OCCUR FRI/SAT /MAXES NEARING 70 OVER THE WEST/ AND POSSIBLY SUN...AT LEAST FOR CENTRAL AND EAST CWA AHEAD OF FRONT BEGINNING TO MOVE INTO THE AREA. EVEN WITH TEMPS THIS WARM DURING THE DAYS THE SNOWMELT COULD END UP MORE GRADUAL WITH DRY AIRMASS AND AS TEMPS AT LEAST INLAND FALL BACK INTO THE 30S. BROUGHT LOW CHANCES FOR RAIN SHOWERS BACK INTO THE FORECAST SUN NIGHT INTO MONDAY AS THE FRONT CROSSES UPR MICHIGAN. WINDS TURNING NE OFF LK SUPERIOR BEHIND THE FRONT COULD LEAD TO SHARPLY COOLER TEMPS OVER THE NORTHERN U.P. COMPARED TO THU-SUN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 124 AM EDT TUE APR 12 2016 AS THE TROUGH AND AREA OF STRONGER LOW LEVEL CONVERGENCE SLIDES OFF TO THE SOUTHEAST OVERNIGHT...EXPECT THE REMAINING SNOW SHOWERS TO DIMINISH WITH VFR VSBY PREVAILING OVERNIGHT. HOWEVER...ENOUGH LOW LEVEL MOISTURE WILL LINGER FOR CIGS NEAR OR SLIGHTLY BELOW MVFR THRESHOLD INTO MID MORNING AT CMX AND IWD. UPSLOPE NE FLOW INTO SAW WILL MORE LIKELY SUSTAIN MVFR CIGS THROUGH MOST OF THE DAY UNTIL WINDS VEER TO THE SE. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT MON APR 11 2016 WITH A SFC TROF PASSAGE...WINDS WILL SHIFT NW TO N LATE AFTN/EVENING. PRES RISES APPROACHING FROM THE NW BEHIND THE TROF WILL HELP TO MAINTAIN GALES INTO THE EVENING OVER THE E HALF OF LAKE SUPERIOR. WINDS WILL THEN DIMINISH W TO E LATE TONIGHT/TUE MORNING AS A HIGH PRES RIDGE APPROACHES FROM THE WEST...THEN DRIFTS ACROSS LAKE SUPERIOR ON TUE. S TO SE WINDS WILL PREVAIL WED THRU FRI AS A HIGH PRES RIDGE SETS UP TO THE E AND SE AND A LOW PRES TROF SETS UP TO THE NW. OVER WRN LAKE SUPERIOR...ESPECIALLY THE FAR W...WINDS WILL TEND TO BE BACKED MORE TO THE E OR NE. SUSTAINED WIND SPEEDS SHOULD GENERALLY BE UNDER 20KT...BUT THERE MAY BE SOME PERIODS WHERE WINDS GUST UP TO 25KT ACROSS PORTIONS OF CNTRL AND ERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...JLA AVIATION...JLB MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EDT TUE APR 12 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 357 PM EDT MON APR 11 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A MID-LVL TROUGH EXTENDING FROM HUDSON BAY INTO THE UPPER GREAT LAKES AND UPPER MISSISSIPPI VALLEY. AT SFC...A LOW WAS CENTERED IN ONTARIO NE OF LAKE SUPERIOR WITH A TROUGH EXTENDING INTO NRN AND WRN LAKE SUPERIOR. DEEPER MOISTURE/CYCLONIC FLOW AND FORCING/INSTABILITY ASSOC WITH THE MID- LVL TROF MOVING OVER THE AREA HAS GENERATED SCT TO NUMEROUS SHSN ACROSS MUCH OF THE FCST AREA TODAY. WITH 850MB TEMPS AROUND -10C AND MODEST DEEP LAYER FORCING...EXPECT LAKE ENHANCED SNOW TO CONTINUE INTO EARLY EVENING INTO THE WRN FCST AREA...ESPECIALLY THE NW...JUST AHEAD OF APPROACHING SFC TROF. UPSLOPING WILL FURTHER ENHANCE PCPN. USING A BLEND OF SOME OF THE NCEP HIGH RES GUIDANCE (ARW/NMM/NAM WINDOW)...REG CANADIAN QPF AND LATEST RAP/HRRR RUNS SUGGESTS A POTENTIAL FOR POSSIBLE ADVY SNOWS ACROSS PORTIONS OF THE HIGH TERRAIN OF NW UPPER MI WITH QPF AMOUNTS OF 0.2 TO AS MUCH AS 0.35 INCHES THIS AFTERNOON INTO THIS EVENING. A FEW LOCATIONS FROM KEWEENAW PENINSULA INTO THE HURON MOUNTAINS REGION (ERN BARAGA/NW MQT COUNTIES) COULD SEE ANYWHERE FROM 3-5 INCHES OF SNOW. HOWEVER...GIVEN THAT SOME OF THIS SNOW WILL BE OCCURRING STILL THIS AFTERNOON AND MELTING ON ROADS FROM HIGHER APRIL SUN ANGLE WORKING THRU CLOUDS...WL PROBABLY HOLD OFF ON ADVISORY. MAY CONSIDER ISSUING A SPS FOR KEWEENAW-HOUGHTON-BARAGA AND MQT COUNTIES FOR SOME SLUSHY SNOW ACCUMULATION IN FAVORED NW FACING HIGHER TERRAIN. AWAY FROM NW UPPER MI...EXPECT ISOLD/SCT - SHSN/FLURRIES TO CONTINUE INTO THIS EVENING FROM LINGERING DAYTIME INSTABILITY. COULD SEE NUMEROUS LAKE ENHANCED SHSN DEVELOP TOWARD EVENING OVER ERN COUNTIES AS WINDS COME AROUND MORE NW WITH FRONTAL PASSAGE...ALTHOUGH WEAKER INSTABILITY SHOULD LIMIT ACCUMULATION THERE TO NO MORE THAN INCH OR TWO. IN ADDITION...EXPECT BLUSTERY NW WINDS TO 25-30 KT TO CONTINUE INTO EARLY EVENING...PERHAPS A BIT HIGHER OVER EXPOSED TERRAIN OF KEWEENAW. AS MID-LVL TROUGH SHIFTS EAST LATE EVENING/OVERNIGHT AND Q-VECT DIV/DRIER AIR SPREADS IN FROM WEST AHEAD OF BUILDING RDG....EXPECT SHSN TO TAPER OFF OR END FM WEST OVERNIGHT. TUE...LOWERING INVERSIONS TO 4KFT AND SHARP DRYING BLO INVERSION SHOULD QUICKLY END ANY LINGERING NW FLOW LES OVER ERN COUNTIES. KEPT WITH CHANCE POPS OVER NCNTRL AND EAST CWA IN THE MORNING...THEN DROP TO SLIGHT CHANCES IN THE EARLY AFTN. ARRIVAL OF SFC RIDGE BRINGS WINDS TO SW OVER WEST HALF IN THE AFTN. LOW-LEVEL MOISTURE STAYS MAINLY TRAPPED BENEATH THE RIDGE...SO SKIES SHOULD REMAIN MOSTLY CLOUDY THROUGH THE DAY. TEMPS STAY ON THE COOLER SIDE OF NORMAL AS H85 THERMAL TROUGH ROTATES THROUGH. HIGHS IN THE LOW 30S NEAR LK SUPERIOR AND TO LOWER 40S FAR WEST AND ALONG WI BORDER ARE EXPECTED. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 328 PM EDT MON APR 11 2016 NAM SHOWS A 500 MB TROUGH OVER THE PACIFIC NW AND A RIDGE OVER THE NORTHERN AND CANADIAN ROCKIES AND A SHORTWAVE OVER THE NORTHERN PLAINS 00Z WED. THE RIDGE MOVES INTO THE NORTHERN PLAINS 12Z WED WITH THE SHORTWAVE OVER THE UPPER GREAT LAKES. THE UPPER RIDGE THEN MOVES INTO THE UPPER GREAT LAKES 12Z THU. NAM BRINGS IN SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE FOR THU NIGHT. NAM...CANADIAN...ECMWF AND GFS ALL SHOW ISENTROPIC LIFT AND MOISTURE ON I285K SURFACE TUE NIGHT INTO WED MORNING. WILL NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST OVERALL AND WILL GO WITH MOSTLY SNOW FOR THE FORECAST TUE NIGHT AND THEN A RAIN AND SNOW MIX FOR WED. DRY FOR WED AFTERNOON INTO THU. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE ACROSS THE ERN U.S. 12Z FRI WITH A DEEP 500 MB TROUGH OVER THE ROCKIES. THE PATTERN CHANGES LITTLE FOR 12Z SAT. BY 12Z SUN...UPPER RIDGE STARTS TO GET FLATTENED. A SHORTWAVE MOVES THROUGH THE UPPER GREAT LAKES SUN NIGHT INTO MON WITH SOME COLDER AIR RETURNING. TEMPERATURES FOR THIS FORECAST PERIOD WILL BE ABOVE NORMAL. WILL BE WARM AND DRY FOR MOST OF THIS FORECAST PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 124 AM EDT TUE APR 12 2016 AS THE TROUGH AND AREA OF STRONGER LOW LEVEL CONVERGENCE SLIDES OFF TO THE SOUTHEAST OVERNIGHT...EXPECT THE REMAINING SNOW SHOWERS TO DIMINISH WITH VFR VSBY PREVAILING OVERNIGHT. HOWEVER...ENOUGH LOW LEVEL MOISTURE WILL LINGER FOR CIGS NEAR OR SLIGHTLY BELOW MVFR THRESHOLD INTO MID MORNING AT CMX AND IWD. UPSLOPE NE FLOW INTO SAW WILL MORE LIKELY SUSTAIN MVFR CIGS THROUGH MOST OF THE DAY UNTIL WINDS VEER TO THE SE. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 357 PM EDT MON APR 11 2016 WITH A SFC TROF PASSAGE...WINDS WILL SHIFT NW TO N LATE AFTN/EVENING. PRES RISES APPROACHING FROM THE NW BEHIND THE TROF WILL HELP TO MAINTAIN GALES INTO THE EVENING OVER THE E HALF OF LAKE SUPERIOR. WINDS WILL THEN DIMINISH W TO E LATE TONIGHT/TUE MORNING AS A HIGH PRES RIDGE APPROACHES FROM THE WEST...THEN DRIFTS ACROSS LAKE SUPERIOR ON TUE. S TO SE WINDS WILL PREVAIL WED THRU FRI AS A HIGH PRES RIDGE SETS UP TO THE E AND SE AND A LOW PRES TROF SETS UP TO THE NW. OVER WRN LAKE SUPERIOR...ESPECIALLY THE FAR W...WINDS WILL TEND TO BE BACKED MORE TO THE E OR NE. SUSTAINED WIND SPEEDS SHOULD GENERALLY BE UNDER 20KT...BUT THERE MAY BE SOME PERIODS WHERE WINDS GUST UP TO 25KT ACROSS PORTIONS OF CNTRL AND ERN LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...07 AVIATION...JLB MARINE...VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
941 AM MDT TUE APR 12 2016 .UPDATE... SMALL SCALE RIDGE IN PLACE THIS MORNING AND THIS WILL PROVIDE A DRY DAY FOR MOST OF THE AREA TODAY. THE RIDGE WILL SLIDE EAST THIS AFTERNOON AND ALLOW MID LEVEL MOISTURE TO STREAM INTO THE WEST AND THE WESTERN MOUNTAINS. HRRR CAPES RISE TO AROUND 400J/KG OVER THE WEST THIS AFTERNOON AND THUS EXPECT SOME SHOWERS WITH ISOLATED THUNDESTORMS. ALL OF THIS LOOKS ON TRACK IN THE GOING FORECAST AND WILL THUS NOT MAKE ANY UPDATES THIS MORNING. TWH && .SHORT TERM...VALID FOR TDY AND WED... RELATIVELY MINOR CHANGES FOR THE SHORT TERM FORECAST THIS MORNING...PRIMARILY TO CLEAN UP BORDERS. CONDITIONS SHOULD BE DRY TO START THE DAY...WITH RIDGE IN PLACE OVER THE REGION. ENERGY STREAMS INTO THE WEST BY THIS AFTERNOON...WITH INCREASING MID LEVEL MOISTURE. SCATTERED CONVECTION IS EXPECTED IN BEARTOOTH/ABSAROKAS AND CRAZY MOUNTAINS AND NEARBY FOOTHILLS DURING THE AFTERNOON. ACTIVITY SHOULD SPREAD EAST AS FAR AS BILLINGS AND SHERIDAN DURING THE EVENING. THE SYSTEM STALLS A BIT AT THIS POINT...PROGRESSING NO FURTHER EAST THROUGH THE NIGHT...AS THE UPPER LOW OVER THE PACIFIC DIGS SOUTH. HEIGHTS CONTINUE TO FALL AS THE RIDGE SLIDES EASTWARD THROUGH THE DAY WEDNESDAY...FINALLY ALLOWING PRECIP TO SPREAD INTO EASTERN ZONES AS EARLY AS WEDNESDAY AFTERNOON. THE TIMING OF EASTWARD PROGRESSION WEDNESDAY MAKES HIGH TEMPS A BIT CHALLENGING. SLOWER MOVEMENT OF GFS WOULD ALLOW GREATER POTENTIAL FOR WARMUP...BUT CLOUD COVER SHOULD HAMPER WARMUP A IT. FASTER MOVEMENT OF ECMWF WOULD CUT OFF DIURNAL HEATING MUCH EARLIER IN THE DAY. CHOSE TO PARE BACK TEMPS ACROSS THE EASTERN ZONES...BUT STILL CONTINUE TO BE WELL ABOVE GUIDANCE. SHOWERS SHOULD PERSIST THROUGH THE EVENING AND INTO WEDNESDAY NIGHT ...BUT THERE IS SOME INDICATION OF DRY SLOTTING ACROSS THE EAST BY LATE THURSDAY NIGHT. GILSTAD .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... COOL AND WET CONDITIONS ARE COMING FOR OUR CWA LATER THIS WEEK...BUT THERE REMAINS A GREAT DEAL OF UNCERTAINTY WITH THE TRACK OF THE UPPER LOW OVER THE ROCKIES...AND EVOLUTION OF WHAT WILL BECOME A VERY BLOCKED LONGWAVE PATTERN ACROSS THE CONUS THIS WEEKEND INTO NEXT WEEK. ASCENT WILL INCREASE SIGNIFICANTLY THURSDAY INTO FRIDAY AS LOW TRACKS FROM THE PAC NW TO THE CENTRAL ROCKIES...LEAVING US UNDER A PERIOD OF STRONG UPPER DIFFLUENCE WITH UPSLOPING SFC TO MID LEVEL FLOW. WITH CONFIDENCE HAVE RAISED POPS FOR THESE PERIODS... ESPECIALLY IN OUR WEST WHERE FORCING SHOULD BE STRONGEST. SOME THUNDERSTORMS ARE POSSIBLE IN SE MT ALONG AXIS OF HIGHER THETA-E AIR. A COMBINATION OF DYNAMIC COOLING AND SOME CANADIAN ADVECTION WILL FORCE 850MB TEMPS DOWN TO NEAR +2C BY FRIDAY...AND THIS MAY BE ENOUGH FOR A MIX WITH SNOW ALONG THE WESTERN FOOTHILLS. BETTER CHANCE OF ANY WET SNOWFALL WILL BE FRIDAY NIGHT BUT IT IS UNCERTAIN IF PCPN WILL CONTINUE. MAIN ISSUE HERE IS THE OVERALL PRECIPITATION AS WE ARE ANTICIPATING LOCATIONS FROM BILLINGS WESTWARD TO SEE AN INCH OR MORE FROM WEDNESDAY THROUGH FRIDAY...A NUMBER THAT IS CONSISTENT WITH THE LATEST MODEL CONSENSUS AND THE PAST SEVERAL GEFS MEANS. COUPLE OTHER ITEMS TO KEEP IN MIND: THE CHILLY AND WET WEATHER MAY BE HAZARDOUS TO YOUNG LIVESTOCK...AND SNOWFALL OVER THE WESTERN MOUNTAINS WILL BE HEAVY THURSDAY NIGHT AND FRIDAY...PARTICULARLY ON N-E ASPECTS. AS ALREADY MENTIONED THE LONGWAVE PATTERN WILL TAKE THE SHAPE OF A STRONG OMEGA BLOCK BY THE END OF THE WEEK...WITH THE ROCKY MOUNTAINS LOW FLANKED BY STRONG RIDGES OVER THE PAC COAST AND MISSISSIPPI/OHIO VALLEYS. AS ONE WOULD EXPECT WITH SUCH A STAGNATING PATTERN THE SPECIFIC EVOLUTION OF THE WESTERN LOW IS HIGHLY IN QUESTION...WITH POOR MODEL-TO-MODEL AND RUN-TO-RUN CONSISTENCY SHOWN OVER THE PAST SEVERAL DAYS. OVERALL CONSENSUS WOULD FAVOR THE SOUTHERN SPLIT LOW TO BECOME DOMINANT BY THIS WEEKEND AS HEIGHTS BEGIN TO RISE OVER THE NORTHERN ROCKIES...SO WILL CONTINUE THE THEME WITH LOWERING POPS FRIDAY NIGHT THROUGH SATURDAY NIGHT...LEAVING OPEN THE POSSIBILITY THAT A PV AXIS TO OUR WEST WILL CONTINUE TO FAVOR WEAK ISENTROPIC ASCENT AND A CHANCE OF LIGHTER PCPN IN OUR CWA INTO THE WEEKEND. CONSENSUS WOULD ALSO FAVOR DRY CONDITIONS BY SUNDAY/MONDAY AS RIDGING EVENTUALLY EXTENDS FROM THE PAC NW OVER OUR REGION. AS FOR TEMPS...FRIDAY/SATURDAY WILL BE THE COOLEST DAYS WITH HIGHS ONLY IN THE 40S TO MID 50S. WARMING TREND SHOULD BEGIN SUNDAY WITH 60S TO PERHAPS LOWER 70S BY MONDAY/TUESDAY OF NEXT WEEK. JKL && .AVIATION... VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY AND TONIGHT. LOOK FOR SCATTERED SHOWERS MAINLY WEST OF KBIL LATE THIS AFTERNOON AND TONIGHT. THESE SHOWERS WILL RESULT IN OCCASIONAL OBSCURATIONS OF THE CRAZY...BEARTOOTH AND ABSAROKA MOUNTAINS. JKL && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 077 047/068 042/060 040/045 034/052 033/058 036/066 1/B 23/W 46/T 88/R 53/W 11/B 11/U LVM 077 042/061 038/056 035/044 030/051 029/058 033/067 2/T 37/T 57/T 88/R 53/W 11/B 11/U HDN 080 042/072 039/062 038/048 032/053 031/060 034/067 1/B 13/W 46/T 77/R 53/W 21/B 11/U MLS 078 043/071 041/065 042/051 034/051 032/059 035/066 0/U 12/W 45/T 75/W 43/W 21/B 11/U 4BQ 079 041/071 041/069 042/054 034/049 032/058 034/065 0/U 12/W 45/T 55/W 44/W 22/W 11/B BHK 076 040/073 041/069 043/054 033/048 030/056 032/062 0/U 12/W 44/T 65/T 44/W 21/B 11/B SHR 075 040/071 040/064 039/048 032/049 030/058 032/064 2/W 22/W 36/T 65/W 43/W 22/W 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1226 PM CDT TUE APR 12 2016 .SYNOPSIS... ISSUED AT 350 AM CDT TUE APR 12 2016 H5 ANALYSIS FROM EARLIER THIS EVENING HAS A BROAD TROUGH OF LOW PRESSURE EXTENDING FROM HUDSON BAY SWD INTO THE NRN GREAT LAKES AND THE EASTERN CORN BELT. RIDGING WAS PRESENT FROM THE PACIFIC NORTHWEST NWD INTO NRN BRITISH COLUMBIA AND THE YUKON. LOW PRESSURE WAS LOCATED UNDERNEATH THE RIDGE ACROSS SRN CALIFORNIA. NWRLY FLOW ALOFT WAS PRESENT ACROSS THE NORTHERN PLAINS FROM NEBRASKA INTO THE DAKOTAS. AT THE SURFACE...HIGH PRESSURE WAS LOCATED OVER SWRN MN AND NWRN IA. FURTHER WEST...A TROUGH OF LOW PRESSURE EXTENDED FROM NORTHERN MONTANA INTO CENTRAL WYOMING. THIS LED TO A DECENT PRESSURE GRADIENT ACROSS CENTRAL AND WESTERN NEBRASKA THIS MORNING. WINDS REMAINED FAIRLY LIGHT FROM THE SOUTH HOWEVER...AS THE BOUNDARY LAYER DECOUPLED SEVERAL HOURS AGO. AS OF 3 AM CDT...TEMPERATURES RANGED FROM 33 AT ONEILL AND BROKEN BOW TO 43 AT IMPERIAL AND THEDFORD. && .UPDATE... ISSUED AT 954 AM CDT TUE APR 12 2016 FORECAST IS ON TRACK WITH MINIMAL CHANGES ANTICIPATED...HOWEVER WILL BE WATCHING THE PROGRESS OF A SURFACE TROUGH ACROSS OUR WESTERN ZONES THIS AFTERNOON. THE 12Z NAM12 RUN WITH SUPPORT FROM THE LATEST HRRR INDICATES A POTENTIAL OF A HIGH BASED THUNDERSHOWER THIS AFTERNOON OVER THE EASTERN PANHANDLE AS MIDLEVEL INSTABILITY INCREASES SLIGHTLY. GIVEN THE LACK OF LOWER TROPOSPHERIC MOISTURE FOR STORM DEVELOPMENT...THE ISOLATED SHOWERS WERE DISCOUNTED ATTM. BUT IF STORMS DEVELOP THIS AFTERNOON...A DRY SUB CLOUD LAYER OF 10K FT OR MORE WOULD ALLOW VERY LITTLE IF ANY RAIN TO HIT THE SURFACE. WILL GET THE WORD OUT TO OUR FIRE PARTNERS VIA THE FWF OF THE POTENTIAL OF A CB OR TWO...AND POSSIBLY GUSTY ERRATIC WINDS NEAR THE CB. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 350 AM CDT TUE APR 12 2016 OVER THE NEXT 24 HOURS...TEMPERATURES... FOLLOWED BY FIRE WEATHER CONCERNS...AND THE THREAT FOR AN ISOLATED THUNDERSTORM IN THE FAR WEST AND SOUTHWESTERN CWA THIS EVENING. WITH THE SURFACE TROUGH WEST AND HIGH PRESSURE TO THE EAST...SOUTHERLY WINDS WILL BE ON THE INCREASE LATER TODAY. THE SOUTHERLY WINDS WILL BEGIN TO ADVECT SOME LOW LEVEL MOISTURE INTO THE WESTERN HALF OF THE CWA LATER THIS AFTERNOON WITH DEW POINTS REACHING THE MIDDLE 30S BY 21Z THIS AFTERNOON. FURTHER EAST...THE SRLY WINDS WILL ONLY RECYCLE DRY AIR AROUND THE WESTERN PERIPHERY OF THE HIGH...RESULTING IN DEW POINTS IN THE FAR EASTERN CWA OF THE UPPER 20S TO LOWER 30S. WINDS WILL BE STRONGEST IN THE CENTRAL AND EASTERN CWA TDY AS THE WESTERN CWA WILL BE IN CLOSER PROXIMITY TO THE SURFACE TROUGH AND THUS LOWER WINDS. WIND SPEEDS THIS AFTERNOON WILL RANGE FROM 10 TO 20 MPH IN THE WEST...AND 15 TO 25 MPH IN THE EAST. MINIMUM RH/S THIS AFTERNOON BOTTOM OUT IN THE 23 TO 30 PERCENT RANGE IN THE EAST. ATTM TOO HIGH FOR ANY RED FLAG HIGHLIGHTS. MORE ABOUT THAT BELOW IN THE FIRE WEATHER SECTION. HIGHS TODAY WILL REACH THE UPPER 60S IN THE EAST...TO LOWER 70S IN THE WEST. LATER TODAY WITH SURFACE HEATING AND A WEAK CONVERGENT SURFACE BOUNDARY IN THE WEST...THERE WILL BE A VERY SMALL THREAT FOR CONVECTIVE DEVELOPMENT ACROSS THE PANHANDLE AND FAR WESTERN CWA LATE THIS AFTERNOON AND EARLY THIS EVENING. ATTM...KEPT POPS AROUND 10 PERCENT AND DIDN/T INTRODUCE ANY MEASURABLE POPS OR MENTION OF THUNDER LATER THIS AFTERNOON OR INTO THE EVENING HOURS. TIME SECTIONS IN THE EASTERN PANHANDLE ARE INDICATIVE OF A VERY DRY LAYER BELOW 10000 FT AGL...WHICH IS EXPECTED TO KEEP ANY PCPN AS SPRINKLES FOR THE MOMENT. FOR TONIGHT...SOME MID AND HIGH CLOUDS WILL LINGER IN THE WEST...SHIFTING EAST OVERNIGHT. TEMPS WILL BE FAIRLY MILD FOR THIS TIME OF YEAR WITH LOWS GENERALLY IN THE LOWER 40S. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 350 AM CDT TUE APR 12 2016 MID RANGE...WEDNESDAY AND THURSDAY... THE PERIOD BEGINS WITH THE AXIS OF THE UPPER RIDGE RUNNING STRAIGHT THROUGH THE FORECAST AREA AND A RETREATING SURFACE HIGH. AS AN UPPER LOW MOVES ONTO THE WEST COAST... THE RIDGE BREAKDOWN COMMENCES ACROSS THE GREAT PLAINS. IN THE LOW LEVELS... A LEE SIDE LOW DEVELOPS AND APPROACHES THE PANHANDLE THURSDAY. FOR WEDNESDAY... MADE LITTLE CHANGE TO MAX TEMPS. PREVIOUS FORECAST HIGHS GENERALLY FOLLOW THE ECS GUIDANCE AND SPLITS THE VERY WARM MAV AND THE RECENTLY TRENDING WARMER MET. WAS HESITANT TO RAISE HIGHS AS TEMPS UPSTREAM ARE NOT CONSIDERABLY WARMER. WITH DECENT MIXING TO AROUND 750HPA... BREEZY SOUTHERLY WINDS... MAINLY FAIR CONDITIONS... AND H85 TEMPS RANGING FROM 20C PANHANDLE TO 15C NORTH CENTRAL... UPPER 70S TO NEAR 80F SEEMED REASONABLE. MODELS ARE CONSISTENT WITH A LLJ DEVELOPING WED NIGHT ACROSS THE WESTERN SANDHILLS. REMOVED SCHC POPS ACROSS NORTHWEST NEB AS LIFT IS VIRTUALLY NON EXISTENT AND VERY DRY AIR REMAINS IN THE LOWER LEVELS. FOR THURSDAY... DID NOT ADJUST MAX TEMPS MUCH AS H85 TEMPS ARE SIMILAR TO WEDNESDAY. A COUPLE DIFFERENCES FROM WED ARE STRONGER MOISTURE ADVECTION... LIKELY FROM LOW LEVEL FLOW TURNING MORE SOUTHEASTERLY... AND A SHALLOWER MIXED LAYER AROUND 800HPA. THICKER CLOUD COVER SHOULD HOLD OFF UNTIL LATE AFTERNOON... WHICH WILL HELP TEMPS REACH UPPER 70S AGAIN. TRIMMED POPS FROM KBBW-KANW AND EAST AFTER 00Z AS MIXING RATIOS AND INSTABILITY ARE SLIGHTLY LOWER THAN FARTHER WEST. DID LEAVE POPS INTACT OVERNIGHT HOWEVER. THUNDER INDICIES DONT LOOK TOO SHABBY WITH MID LEVEL LAPSE RATES 7-8C/KM... MUCAPE OVER 1000J/KG... AND NEGATIVE LIFTED INDEX. LONG RANGE...FRIDAY THROUGH MONDAY... WESTERN NEBRASKA LIES IN SOUTHWEST FLOW FOR THE FIRST PART OF THE WEEKEND AS A CLOSED LOW OVER THE SOUTHWEST U.S. SLOWS TO A CRAWLING PACE. THE LOW THEN WORKS ITS WAY NORTHEAST ONTO THE CENTRAL PLAINS LATE SAT/EARLY SUN... WITH THE EURO PLACING IT ON TOP OF THE FORECAST AREA MONDAY AFTERNOON. MAX TEMPS HAVE TRENDED DOWN SLIGHTLY FRIDAY TO SUNDAY TO ACCOUNT FOR PERSISTENT CLOUD COVER AND WHAT COULD BE AN EXTENDED PERIOD OF PRECIP. FELT CONFIDENT TO LEAVE LIKELY POPS LATE FRIDAY TO EARLY SUNDAY FOR THE AREA. DEW POINTS INCHING UP FROM PREVIOUS MODEL RUNS WITH DECENT COVERAGE OF 50+ FRIDAY AND SATURDAY. ENSEMBLES CONTINUE TO INDICATE NEAR RECORD PWAT VALUES FOR THE HIGH PLAINS OVER THE WEEKEND. IN ADDITION... GFS FORECAST SOUNDINGS SHOW A SATURATED COLUMN AND STRONG LIFT WITH OMEGA NEAR -20US. OVERNIGHT TEMPS DROP INTO THE 30S ACROSS NORTHWEST NEBRASKA... BUT TEMPS REMAIN ABOVE FREEZING UP TO 700HPA... SO KEPT PTYPE AS ALL RAIN. JET DYNAMICS IN THE EURO ARE SUPPORTIVE FOR SEVERE WEATHER FOR WESTERN NEBRASKA ON SATURDAY AND SUNDAY AS THE AREA LIES IN THE ENTRANCE REGION OF A 100+KT 250HPA JET STREAK. GFS BRINGS THE JET STREAK A LITTLE FARTHER WEST AND SLIGHTLY WEAKER... BUT THE AREA WILL STILL EXPERIENCE ABUNDANT DIVERGENCE ALOFT WITH THE MAGNITUDE OF THE EASTERN U.S. RIDGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1226 PM CDT TUE APR 12 2016 THE LATEST NEAR TERM GUIDANCE INDICATES THE POTENTIAL OF ISOLATED HIGH BASED THUNDERSTORMS ACROSS SOUTHWEST NEBRASKA AND THE EASTERN PANHANDLE THIS AFTERNOON. IF A STORM DEVELOPS...ONLY MINOR VISIBILITY RESTRICTIONS WOULD BE ANTICIPATED DUE TO EVAPORATION IN THE DRY SUB CLOUD LAYER. OTHERWISE GUSTY /TO 30KTS AT TIMES/ SOUTH TO SOUTHWEST WINDS WILL CONTINUE FOR MOST WEST CENTRAL NEBRASKA TERMINALS THROUGH THE AFTERNOON...BUT WEAKEN INTO THE EVENING. && .FIRE WEATHER... ISSUED AT 350 AM CDT TUE APR 12 2016 AS MENTIONED ABOVE...MINIMUM RELATIVE HUMIDITY WILL REACH 23 TO 30 PERCENT IN THE EASTERN CWA THIS AFTERNOON. SRLY WINDS WILL BE FAIRLY STRONG THIS AFTERNOON WITH SPEEDS OF 20 TO 30 MPH EXPECTED. THE 23 TO 30 PERCENT MIN RH WILL FLIRT WITH THE MINIMUM RH CRITERIA OF 20 PERCENT FOR ZONE 209. ATTM...MIN RH FCST WILL BE ABOVE THE THRESHOLD FOR A RED FLAG WARNING...SO WILL NOT BE ISSUING A RFW WITH THE AM PACKAGE. WILL CONTINUE TO HIT THE FIRE DANGER IN THE HWO TDY AS EXTREME...BUT NOT CRITICAL...FIRE WEATHER CONDITIONS ARE EXPECTED. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JACOBS SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SNIVELY AVIATION...JACOBS FIRE WEATHER...BUTTLER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
954 AM CDT TUE APR 12 2016 .SYNOPSIS... ISSUED AT 350 AM CDT TUE APR 12 2016 H5 ANALYSIS FROM EARLIER THIS EVENING HAS A BROAD TROUGH OF LOW PRESSURE EXTENDING FROM HUDSON BAY SWD INTO THE NRN GREAT LAKES AND THE EASTERN CORN BELT. RIDGING WAS PRESENT FROM THE PACIFIC NORTHWEST NWD INTO NRN BRITISH COLUMBIA AND THE YUKON. LOW PRESSURE WAS LOCATED UNDERNEATH THE RIDGE ACROSS SRN CALIFORNIA. NWRLY FLOW ALOFT WAS PRESENT ACROSS THE NORTHERN PLAINS FROM NEBRASKA INTO THE DAKOTAS. AT THE SURFACE...HIGH PRESSURE WAS LOCATED OVER SWRN MN AND NWRN IA. FURTHER WEST...A TROUGH OF LOW PRESSURE EXTENDED FROM NORTHERN MONTANA INTO CENTRAL WYOMING. THIS LED TO A DECENT PRESSURE GRADIENT ACROSS CENTRAL AND WESTERN NEBRASKA THIS MORNING. WINDS REMAINED FAIRLY LIGHT FROM THE SOUTH HOWEVER...AS THE BOUNDARY LAYER DECOUPLED SEVERAL HOURS AGO. AS OF 3 AM CDT...TEMPERATURES RANGED FROM 33 AT ONEILL AND BROKEN BOW TO 43 AT IMPERIAL AND THEDFORD. && .UPDATE... ISSUED AT 954 AM CDT TUE APR 12 2016 FORECAST IS ON TRACK WITH MINIMAL CHANGES ANTICIPATED...HOWEVER WILL BE WATCHING THE PROGRESS OF A SURFACE TROUGH ACROSS OUR WESTERN ZONES THIS AFTERNOON. THE 12Z NAM12 RUN WITH SUPPORT FROM THE LATEST HRRR INDICATES A POTENTIAL OF A HIGH BASED THUNDERSHOWER THIS AFTERNOON OVER THE EASTERN PANHANDLE AS MIDLEVEL INSTABILITY INCREASES SLIGHTLY. GIVEN THE LACK OF LOWER TROPOSPHERIC MOISTURE FOR STORM DEVELOPMENT...THE ISOLATED SHOWERS WERE DISCOUNTED ATTM. BUT IF STORMS DEVELOP THIS AFTERNOON...A DRY SUB CLOUD LAYER OF 10K FT OR MORE WOULD ALLOW VERY LITTLE IF ANY RAIN TO HIT THE SURFACE. WILL GET THE WORD OUT TO OUR FIRE PARTNERS VIA THE FWF OF THE POTENTIAL OF A CB OR TWO...AND POSSIBLY GUSTY ERRATIC WINDS NEAR THE CB. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 350 AM CDT TUE APR 12 2016 OVER THE NEXT 24 HOURS...TEMPERATURES... FOLLOWED BY FIRE WEATHER CONCERNS...AND THE THREAT FOR AN ISOLATED THUNDERSTORM IN THE FAR WEST AND SOUTHWESTERN CWA THIS EVENING. WITH THE SURFACE TROUGH WEST AND HIGH PRESSURE TO THE EAST...SOUTHERLY WINDS WILL BE ON THE INCREASE LATER TODAY. THE SOUTHERLY WINDS WILL BEGIN TO ADVECT SOME LOW LEVEL MOISTURE INTO THE WESTERN HALF OF THE CWA LATER THIS AFTERNOON WITH DEW POINTS REACHING THE MIDDLE 30S BY 21Z THIS AFTERNOON. FURTHER EAST...THE SRLY WINDS WILL ONLY RECYCLE DRY AIR AROUND THE WESTERN PERIPHERY OF THE HIGH...RESULTING IN DEW POINTS IN THE FAR EASTERN CWA OF THE UPPER 20S TO LOWER 30S. WINDS WILL BE STRONGEST IN THE CENTRAL AND EASTERN CWA TDY AS THE WESTERN CWA WILL BE IN CLOSER PROXIMITY TO THE SURFACE TROUGH AND THUS LOWER WINDS. WIND SPEEDS THIS AFTERNOON WILL RANGE FROM 10 TO 20 MPH IN THE WEST...AND 15 TO 25 MPH IN THE EAST. MINIMUM RH/S THIS AFTERNOON BOTTOM OUT IN THE 23 TO 30 PERCENT RANGE IN THE EAST. ATTM TOO HIGH FOR ANY RED FLAG HIGHLIGHTS. MORE ABOUT THAT BELOW IN THE FIRE WEATHER SECTION. HIGHS TODAY WILL REACH THE UPPER 60S IN THE EAST...TO LOWER 70S IN THE WEST. LATER TODAY WITH SURFACE HEATING AND A WEAK CONVERGENT SURFACE BOUNDARY IN THE WEST...THERE WILL BE A VERY SMALL THREAT FOR CONVECTIVE DEVELOPMENT ACROSS THE PANHANDLE AND FAR WESTERN CWA LATE THIS AFTERNOON AND EARLY THIS EVENING. ATTM...KEPT POPS AROUND 10 PERCENT AND DIDN/T INTRODUCE ANY MEASURABLE POPS OR MENTION OF THUNDER LATER THIS AFTERNOON OR INTO THE EVENING HOURS. TIME SECTIONS IN THE EASTERN PANHANDLE ARE INDICATIVE OF A VERY DRY LAYER BELOW 10000 FT AGL...WHICH IS EXPECTED TO KEEP ANY PCPN AS SPRINKLES FOR THE MOMENT. FOR TONIGHT...SOME MID AND HIGH CLOUDS WILL LINGER IN THE WEST...SHIFTING EAST OVERNIGHT. TEMPS WILL BE FAIRLY MILD FOR THIS TIME OF YEAR WITH LOWS GENERALLY IN THE LOWER 40S. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 350 AM CDT TUE APR 12 2016 MID RANGE...WEDNESDAY AND THURSDAY... THE PERIOD BEGINS WITH THE AXIS OF THE UPPER RIDGE RUNNING STRAIGHT THROUGH THE FORECAST AREA AND A RETREATING SURFACE HIGH. AS AN UPPER LOW MOVES ONTO THE WEST COAST... THE RIDGE BREAKDOWN COMMENCES ACROSS THE GREAT PLAINS. IN THE LOW LEVELS... A LEE SIDE LOW DEVELOPS AND APPROACHES THE PANHANDLE THURSDAY. FOR WEDNESDAY... MADE LITTLE CHANGE TO MAX TEMPS. PREVIOUS FORECAST HIGHS GENERALLY FOLLOW THE ECS GUIDANCE AND SPLITS THE VERY WARM MAV AND THE RECENTLY TRENDING WARMER MET. WAS HESITANT TO RAISE HIGHS AS TEMPS UPSTREAM ARE NOT CONSIDERABLY WARMER. WITH DECENT MIXING TO AROUND 750HPA... BREEZY SOUTHERLY WINDS... MAINLY FAIR CONDITIONS... AND H85 TEMPS RANGING FROM 20C PANHANDLE TO 15C NORTH CENTRAL... UPPER 70S TO NEAR 80F SEEMED REASONABLE. MODELS ARE CONSISTENT WITH A LLJ DEVELOPING WED NIGHT ACROSS THE WESTERN SANDHILLS. REMOVED SCHC POPS ACROSS NORTHWEST NEB AS LIFT IS VIRTUALLY NON EXISTENT AND VERY DRY AIR REMAINS IN THE LOWER LEVELS. FOR THURSDAY... DID NOT ADJUST MAX TEMPS MUCH AS H85 TEMPS ARE SIMILAR TO WEDNESDAY. A COUPLE DIFFERENCES FROM WED ARE STRONGER MOISTURE ADVECTION... LIKELY FROM LOW LEVEL FLOW TURNING MORE SOUTHEASTERLY... AND A SHALLOWER MIXED LAYER AROUND 800HPA. THICKER CLOUD COVER SHOULD HOLD OFF UNTIL LATE AFTERNOON... WHICH WILL HELP TEMPS REACH UPPER 70S AGAIN. TRIMMED POPS FROM KBBW-KANW AND EAST AFTER 00Z AS MIXING RATIOS AND INSTABILITY ARE SLIGHTLY LOWER THAN FARTHER WEST. DID LEAVE POPS INTACT OVERNIGHT HOWEVER. THUNDER INDICIES DONT LOOK TOO SHABBY WITH MID LEVEL LAPSE RATES 7-8C/KM... MUCAPE OVER 1000J/KG... AND NEGATIVE LIFTED INDEX. LONG RANGE...FRIDAY THROUGH MONDAY... WESTERN NEBRASKA LIES IN SOUTHWEST FLOW FOR THE FIRST PART OF THE WEEKEND AS A CLOSED LOW OVER THE SOUTHWEST U.S. SLOWS TO A CRAWLING PACE. THE LOW THEN WORKS ITS WAY NORTHEAST ONTO THE CENTRAL PLAINS LATE SAT/EARLY SUN... WITH THE EURO PLACING IT ON TOP OF THE FORECAST AREA MONDAY AFTERNOON. MAX TEMPS HAVE TRENDED DOWN SLIGHTLY FRIDAY TO SUNDAY TO ACCOUNT FOR PERSISTENT CLOUD COVER AND WHAT COULD BE AN EXTENDED PERIOD OF PRECIP. FELT CONFIDENT TO LEAVE LIKELY POPS LATE FRIDAY TO EARLY SUNDAY FOR THE AREA. DEW POINTS INCHING UP FROM PREVIOUS MODEL RUNS WITH DECENT COVERAGE OF 50+ FRIDAY AND SATURDAY. ENSEMBLES CONTINUE TO INDICATE NEAR RECORD PWAT VALUES FOR THE HIGH PLAINS OVER THE WEEKEND. IN ADDITION... GFS FORECAST SOUNDINGS SHOW A SATURATED COLUMN AND STRONG LIFT WITH OMEGA NEAR -20US. OVERNIGHT TEMPS DROP INTO THE 30S ACROSS NORTHWEST NEBRASKA... BUT TEMPS REMAIN ABOVE FREEZING UP TO 700HPA... SO KEPT PTYPE AS ALL RAIN. JET DYNAMICS IN THE EURO ARE SUPPORTIVE FOR SEVERE WEATHER FOR WESTERN NEBRASKA ON SATURDAY AND SUNDAY AS THE AREA LIES IN THE ENTRANCE REGION OF A 100+KT 250HPA JET STREAK. GFS BRINGS THE JET STREAK A LITTLE FARTHER WEST AND SLIGHTLY WEAKER... BUT THE AREA WILL STILL EXPERIENCE ABUNDANT DIVERGENCE ALOFT WITH THE MAGNITUDE OF THE EASTERN U.S. RIDGE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 644 AM CDT TUE APR 12 2016 EXPECT MAINLY CLEAR SKIES ACROSS WESTERN AND NORTH NORTH CENTRAL NEBRASKA OVER THE NEXT 24 HOURS. WINDS WILL INCREASE FROM THE SOUTH AT 15 TO 25 KTS BY MID MORNING AND WILL PERSIST THROUGH SUNSET THIS EVENING. SOUTHERLY WINDS WILL THEN DECREASE TO UNDER 10 KTS TONIGHT. && .FIRE WEATHER... ISSUED AT 350 AM CDT TUE APR 12 2016 AS MENTIONED ABOVE...MINIMUM RELATIVE HUMIDITY WILL REACH 23 TO 30 PERCENT IN THE EASTERN CWA THIS AFTERNOON. SRLY WINDS WILL BE FAIRLY STRONG THIS AFTERNOON WITH SPEEDS OF 20 TO 30 MPH EXPECTED. THE 23 TO 30 PERCENT MIN RH WILL FLIRT WITH THE MINIMUM RH CRITERIA OF 20 PERCENT FOR ZONE 209. ATTM...MIN RH FCST WILL BE ABOVE THE THRESHOLD FOR A RED FLAG WARNING...SO WILL NOT BE ISSUING A RFW WITH THE AM PACKAGE. WILL CONTINUE TO HIT THE FIRE DANGER IN THE HWO TDY AS EXTREME...BUT NOT CRITICAL...FIRE WEATHER CONDITIONS ARE EXPECTED. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JACOBS SYNOPSIS...BUTTLER SHORT TERM...BUTTLER LONG TERM...SNIVELY AVIATION...BUTTLER FIRE WEATHER...BUTTLER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1233 AM CDT TUE APR 12 2016 .UPDATE... ISSUED AT 1233 AM CDT TUE APR 12 2016 SOME SLIGHT ADJUSTMENTS HAVE BEEN MADE TO SKY AND DWPTS. DWPTS ARE VERY LOW E OF HWY 281. CURRENT OBS WERE BLENDED WITH THE RAP MODEL THE REST OF THE NIGHT AS THE RAP HAS A BETTER HANDLE ON LOW DWPTS. THERE IS A PATCH OF ALTOCU W OF HWY 183 AND IT HAS RESULTED IN QUITE A DISPARITY IN TEMPS. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 1233 AM CDT TUE APR 12 2016 THIS SERVES AS A FIRST DRAFT FOR THIS SHIFT... ALOFT: SPLIT FLOW WAS OVER THE CONUS. THE FCST AREA WILL BE UNDER THE INFLUENCE OF THE NRN STREAM. AT THIS TIME...A RIDGE WAS OVER THE NRN ROCKIES WITH A TROF OVER THE GREAT LAKES. THE FLOW WILL BECOME PROGRESSIVE WITH THE RIDGE MOVING OVER THE NRN PLAINS BY 12Z/WED. THERE IS A WEAK SHORTWAVE TROF IN THE NW FLOW AHEAD OF THE RIDGE OVER ALBERTA/SASK. THE TAIL END OF THIS TROF WILL MOVE THRU 00Z-06Z TONIGHT BUT WITH NO NOTICEABLE WX. SURFACE: HIGH PRES WAS OVER THE MID/UPR MS VALLEY. THIS HIGH WILL MIGRATE TO THE GREAT LAKES BY 00Z AND THEN INTO THE ERN USA/CANADA BY 12Z/WED. RETURN FLOW DEVELOPS HERE ON THE PLAINS TODAY. THE POLAR FRONT THAT MOVED THRU HERE SUNDAY WAS BANKED UP AGAINST THE ROCKIES. THE PORTION MT/WY WILL MOVE E INTO THE DAKOTAS AS A WARM FRONT. TODAY: SUNNY WITH A FEW ALTOCU POSSIBLE THIS MORNING. YOU CAN PROBABLY ADD 10F TO YESTERDAY`S TEMPS. BECOMING WINDY W OF FROM THE TRI-CITIES N AND W WITH GUSTS UP TO 35 MPH. WINDS WILL BE LOWER TO THE S AND E. TONIGHT: M/CLEAR. MORE LATER... .MID TERM...(TUESDAY NIGHT THROUGH THURSDAY DAYTIME) ISSUED AT 403 PM CDT MON APR 11 2016 SUMMARIZING THIS 48-HOUR "MID TERM" PERIOD: IT SEEMS HARD TO BELIEVE THAT WE`RE SAYING THIS AS DRY AS IT`S BEEN FOR THE PAST SEVERAL WEEKS...BUT FOR FOLKS WANTING TO GET OUTDOOR WORK/PROJECTS DONE WITHOUT A THREAT OF RAIN THEN YOU PROBABLY SHOULD TAKE ADVANTAGE OF THESE NEXT FEW DAYS INCLUDING WEDNESDAY- THURSDAY. BEYOND THAT LOOMS WHAT APPEARS TO BE BY FAR OUR BEST CHANCE OF WIDESPREAD/POTENTIALLY SOAKING PRECIPITATION THAT WE HAVE SEEN YET THIS SPRING (SEE LONG TERM SECTION BELOW FOR MORE ON THIS). IN THE MEANTIME THOUGH...THE MID-WEEK TIME FRAME STILL APPEARS TO BE NEARLY "GUARANTEED" DRY...WITH HIGH TEMPERATURES WARMING WELL BACK UP INTO THE 70S AND LOW TEMPERATURES HOLDING UP WELL-ABOVE FREEZING. OF COURSE...WE`VE HEARD PLENTY OF "COMPLAINTS" LATELY ABOUT THE WIND...AND UNFORTUNATELY WEDNESDAY HAS TRENDED A BIT BREEZIER THAN PREVIOUSLY INDICATED AND THURSDAY STILL LOOKS SOLIDLY BREEZY-TO-WINDY OUT OF THE SOUTH. FORTUNATELY THOUGH...IN A NICE CHANGE FROM RECENT/ONGOING CONDITIONS...IT APPEARS THAT LOW-LEVEL MOISTURE/DEWPOINTS SHOULD INCREASE "JUST" ENOUGH TO KEEP AFTERNOON RELATIVE HUMIDITY (RH) VALUES ABOVE 25 PERCENT BOTH WED/THURS AND THUS KEEP FIRE WEATHER CONDITIONS FROM EVEN REACHING "NEAR-CRITICAL" CRITERIA. BECAUSE OF THIS...THERE ARE NO ELEMENTS WORTHY OF INCLUSION IN THE HAZARDOUS WEATHER OUTLOOK (HWOGID) DURING THESE MID-TERM PERIODS. NOW GOING OVER EACH OF THESE 4 FORECAST PERIODS IN MORE DETAIL: TUESDAY EVENING/NIGHT: VERY WEAK MID-UPPER LEVEL FLOW PUSHES INTO THE CENTRAL PLAINS UNDER BROAD RIDGING ALOFT AS WE SIT IN A PRONOUNCED MINIMUM IN UPPER FORCING BETWEEN THE NORTHERN/SOUTHERN JET BRANCHES. ANY EARLY EVENING SHOWERS THAT MAY FORM TO OUR WEST IN THE NEB PANHANDLE AREA SHOULDN`T BE A FACTOR LOCALLY AT ALL. UNDER MOSTLY CLEAR SKIES...BREEZES WILL AVERAGE NO MORE THAN 10-15 MPH FROM THE SOUTH FOR THE NIGHT AS A WHOLE. THANKS LARGELY TO THESE LIGHT-BUT-STEADY BREEZES...TEMPERATURES SHOULD HOLD UP 5-10 DEGREES MILDER THAN TONIGHT AND SAFELY ABOVE FREEZING. MADE VERY LITTLE CHANGE HERE...AIMING LOWS 38-40 MOST AREAS. WEDNESDAY DAYTIME: FOR THOSE MONITORING WIND FORECASTS CLOSELY...PLEASE NOTE THAT SOUTHERLY SPEEDS WERE RAISED ROUGHLY 5 MPH FROM PREVIOUS FORECAST AND POSSIBLY NOT QUITE ENOUGH. ALTHOUGH CONFIDENCE REMAINS HIGH IN A DRY/MOSTLY SUNNY DAY WITH BROAD RIDGING/WEAK FLOW ALOFT THE DOMINANT INFLUENCE...THE DEVELOPMENT OF A MODEST HIGH PLAINS LEE TROUGH SHOULD ALLOW SOUTH WINDS TO AVERAGE SUSTAINED VALUES GENERALLY 14-18 MPH/GUSTS UP TO AROUND 25 MPH DURING THE AFTERNOON. MADE LITTLE TO NO CHANGE TO HIGH TEMPS...STILL EXPECTING A ROUGHLY 10 DEGREE RISE VERSUS TUESDAY WITH MOST PLACES ATTAINING THE 73-77 RANGE. WEDNESDAY NIGHT: IT REMAINS DRY AS ANY POSSIBLE SHOWERS/STORMS OVER NORTHWEST NEBRASKA SHOULD REMAIN WELL-OUTSIDE THE CWA. LIKE THE PREVIOUS NIGHT...SOUTH BREEZES WILL AVERAGE 10-15 MPH...BUT THANKS TO A WARMER PRECEDING DAY AND SLOWLY-INCREASING LOW LEVEL MOISTURE...LOW TEMPS WILL JUMP UP ANOTHER 8-10 DEGREES VERSUS THE PREVIOUS NIGHT...HOLDING UP GENERALLY 47-50. THURSDAY DAYTIME: CONFIDENCE REMAINS FAIRLY HIGH IN A DRY DAY...BUT CHANGES IN THE LARGE-SCALE PATTERN WILL START TO BECOME MORE EVIDENT TO OUR WEST AS A LARGE-SCALE TROUGH SETS UP SHOP OVER THE WESTERN CONUS. THANKS TO STRONGER PRESSURE FALLS ALONG A HIGH PLAINS LEE TROUGH...SOUTHERLY WINDS WILL CRANK UP ANOTHER NOTCH. OUR FORECAST MAY NOT BE QUITE STRONG ENOUGH...BUT FOR NOW WILL CALL FOR SUSTAINED 15-25 MPH/GUSTS 25-35 MPH. NUDGED UP HIGH TEMPS VERY SLIGHTLY AS THEY SHOULD BE A TOUCH WARMER THAN WEDNESDAY... AIMING FOR MAINLY A 76-79 RANGE. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 403 PM CDT MON APR 11 2016 THIS SECTION FOCUSES ONLY ON THE "LONG TERM" PERIOD (DAYS 4-7) FOR WHICH THE FORECAST IS PRIMARILY DERIVED FROM A DEFAULT MULTI-MODEL BLEND WITH ONLY LIMITED MODIFICATION BY THE FORECASTER: SUMMARIZING THIS 4-DAY PERIOD: OF COURSE...THE DETAILS OF AMOUNTS/TIMING ARE FAR...FAR FROM CERTAIN AT THIS TIME RANGE...BUT CONFIDENCE IS SLOWLY INCREASING THAT WE WILL BE ENTERING BY FAR THE MOST PRONOUNCED WETTER WEATHER PATTERN OF THE SPRING SEASON SO FAR. LITERALLY EACH AND EVERY DAY/NIGHT FORECAST PERIOD FROM THURSDAY NIGHT THROUGH MONDAY (AND POSSIBLY EXTENDING INTO NEXT TUESDAY AS WELL IN LATER FORECASTS) CARRIES AT LEAST MODEST...IF NOT DOWNRIGHT "LIKELY" (60 PERCENT OR HIGHER) CHANCES FOR MEASURABLE RAIN AS A LARGE-SCALE LOW PRESSURE SYSTEM STALLS OUT FOR SEVERAL DAYS OVER THE ROCKIES/HIGH PLAINS BEFORE FINALLY PUSHING THROUGH AND TO OUR EAST SOMETIME EARLY NEXT WEEK. NOW ALL THIS BEING SAID...IT`S OBVIOUSLY NOT GOING TO BE RAINING NON-STOP FOR 4+ DAYS...AND IT`S DICEY-AT-BEST TO TRY PINPOINTING THE OVERALL-HIGHEST RAIN CHANCES THIS FAR IN ADVANCE GIVEN THAT SO MUCH WILL DEPEND ON SMALL SCALE/MESOSCALE DETAILS SUCH AS THE EXACT TIMING OF SEVERAL SMALL DISTURBANCES "BREAKING OFF" OF THE MAIN UPPER LOW AND SWINGING INTO THE LOCAL AREA. ADDING TO THE TIMING UNCERTAINTY IS THE FACT THAT THESE TYPES OF LARGE-SCALE SYSTEMS OFTEN HAVE A TENDENCY TO SLOW DOWN A BIT AS THEY GET CLOSER...AND WITH THE FLOW ALOFT MAINLY ORIENTED SOUTH- TO-NORTH (MERIDIONAL)...IT`S POSSIBLE (NOT FOR SURE) THAT THE FIRST FEW DAYS OF RAIN CHANCES (GENERALLY FRIDAY-SATURDAY) COULD SEE MOST OF THE "ACTION" FOCUS JUST TO OUR WEST BEFORE SHIFTING MORE SOLIDLY EAST OVER OUR CWA IN THE SUNDAY-MONDAY TIME FRAME. VERY PRELIMINARILY...THE HIGHEST RAIN CHANCES (60+ PERCENT "LIKELY") ARE CURRENTLY FOCUSED WITHIN THE CWA DURING THE FRIDAY NIGHT-SUNDAY NIGHT TIME FRAME...BUT DON`T BE SURPRISED IF THE DEFAULT LONG TERM MULTI-MODEL BLEND SHIFTS THESE CHANCES AROUND A BIT IN TIME AND SPACE OVER THE NEXT SEVERAL DAYS. BRIEFLY COMMENTING ON TEMPERATURES: HIGHS ARE AIMED MAINLY IN THE 60S ON THESE DAYS WITH LOWS WELL UP INTO THE UPPER 40S-MID 50S RANGE. IN OTHER WORDS...FREEZING TEMPERATURES MOST DEFINITELY WON`T BE A CONCERN. WILL FINISH BY ADDRESSING A FEW QUESTIONS MANY FOLKS MIGHT HAVE ABOUT THE NUMEROUS RAIN CHANCES: 1) JUST HOW MUCH RAIN ARE WE TALKING? AGAIN...IT`S FOOLISH TO BUY INTO RAW MODEL QPF VALUES "VERBATIM" AT THIS JUNCTURE...BUT OFFICIAL WEATHER PREDICTION CENTER (WPC) GUIDANCE SUGGESTS A GENERAL RANGE OF AT LEAST 1-3" CAN BE EXPECTED OVER THE COURSE OF SEVERAL DAYS...WITH LOCALLY HIGHER AMOUNTS CERTAINLY NOT OUT OF THE QUESTION. AGAIN...THIS IS A MULTI-DAY ACCUMULATION POTENTIAL...AND SOME DAYS/NIGHTS WILL BE DRIER THAN OTHERS. ALTHOUGH IT SEEMS HARD TO BELIEVE GIVEN HOW DRY IT`S BEEN LATELY...IT MAY NOT TAKE MUCH TO GET LOCALIZED/MINOR FLOODING TO OCCUR FROM ANY STEADIER/CONCENTRATED ZONES OF RAIN GIVEN THAT THE GROUND IS FAIRLY "HARD" AND THAT LIMITED EARLY SPRING VEGETATIVE GROWTH WILL DO LITTLE TO PREVENT RUNOFF. 2) WILL THERE BE ONE OR MORE SEVERE STORM CHANCES? WELL...GIVEN THAT IT`S APRIL AND WE ARE TALKING ABOUT A LARGE UPPER LOW PRESSURE SYSTEM ONE CERTAINLY CAN`T RULE OUT AT LEAST AN ISOLATED/BRIEF SEVERE WEATHER THREAT ON ONE OR MORE DAYS BETWEEN FRIDAY-MONDAY. HOWEVER...AT LEAST AT THIS DAY 4-7 RANGE...MODELS SUCH AS THE ECMWF/GFS SEEM MORE INDICATIVE OF A LIMITED CAPE/INSTABILITY ENVIRONMENT WITH FAIRLY MOIST/SATURATED PROFILES AND FAIRLY MODEST MID LEVEL LAPSE RATES. AS A RESULT...THIS JUST SEEMS LIKE MORE OF A LOCALIZED HEAVY RAIN SETUP THAN A SEVERE WEATHER ONE FOR NOW...BUT LATER MESOSCALE DETAILS COULD ALWAYS DICTATE OTHERWISE. FOR NOW THOUGH...WILL GENERALLY "DOWNPLAY" THE THUNDERSTORM ASPECT BY USING "ISOLATED" THUNDER WORDING. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUE NIGHT) ISSUED AT 1233 AM CDT TUE APR 12 2016 SIGNIFICANT WEATHER: STRONG CROSS WINDS TODAY ON RWY 13/31 AT BOTH TERMINALS. OVERNIGHT: VFR WITH JUST A LITTLE ALTOCU AROUND 8K FT. LIGHT ESE WINDS UNDER 10 KTS. CONFIDENCE: HIGH TUE: VFR. A FEW ALTOCU 8-10K FT. WINDS BECOME S AND INCREASE 20-30 KTS. CONFIDENCE: HIGH TUE EVE: VFR. A FEW ALTOCU AROUND 12K FT POSSIBLE. S WINDS DIMINISH TO 10-15 KTS. MARGINAL LLWS POSSIBLE...BUT IT`S NOT IN THE TAFS YET. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...HALBLAUB SHORT TERM...HALBLAUB LONG TERM...PFANNKUCH AVIATION...HALBLAUB
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1150 PM CDT MON APR 11 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 326 PM CDT MON APR 11 2016 THE LATEST HRRR CONTINUES TO INDICATE THE PRESENCE OF LOW CEILINGS AND THE POSSIBILITY OF A SPRINKLE OR TWO ACROSS SOUTHWEST NEBRASKA THIS AFTERNOON/EARLY EVENING WHERE WEAK INSTABILITY RESIDES IN A SHALLOW LAYER OF MOISTURE. THE STRATUS IS SLOWLY ERODING...BUT WHERE ENOUGH ISOLATION IS OCCURRING...CU WITH LIMITED GROWTH HAVE SLOWLY SPROUTED UP. IT IS CONCEIVABLE THAT A ISOLATED SHOWER COULD BRIEFLY IMPACT A COMMUNITY OVER SW NEB INTO EARLY EVENING HOURS...BUT ANY RAINFALL WOULD BE LIGHT. SINCE THE KLNX WSR-88D IS QUIET WITH NO DISCERNABLE RETURNS...WE WILL KEEP THE FORECAST DRY THIS AFTERNOON AND EVENING...BUT CONTINUE TO MONITOR. FOR THE OVERNIGHT AND TUESDAY...MODIFIED POLAR HIGH PRESSURE WILL BUILD EAST OF THE CWA ALLOWING FOR RETURN SOUTHERLY FLOW. THE WINDS WILL INCREASE OVERNIGHT AND WHEN COMBINED WITH WEAK WAA FROM THE SOUTHWEST...WARMER OVERNIGHT LOWS ARE FORECAST. LOWER 30S ARE FORECAST ACROSS OUR EASTERN ZONES...BUT OVER WESTERN PORTIONS OF THE CWA...UPPER 30S TO LOWER 40S ARE POSSIBLE. A NON-DIURNAL TREND IS POSSIBLE AS WINDS INCREASE AND THE WAA IS STRONGEST TOWARD DAWN. THE WAA AND SOUTHWESTERLY FLOW IS MAXIMIZED TUESDAY MORNING AND EARLY AFTERNOON...ALLOWING H85 TEMPERATURES TO WARM ABOVE 20C ACROSS THE ENTIRE CWA. THIS WILL PROMOTE A SOLID WARMING TREND IN HIGH TEMPERATURES...WITH UPPER 60S TO MID 70S FROM EAST TO WEST ACROSS THE CWA. A SFC TROUGH DEEPENING ON THE LEE OF THE ROCKIES WILL INCREASE THE PRESSURE GRADIENT...PROVIDING FOR GUSTY CONDITIONS OVER MUCH OF THE CWA. THE EXCEPTION WILL BE ACROSS NW NEB WHERE THE SFC TROUGH WILL RESIDE. THESE WX CONDITIONS WILL PROMOTE LARGE RANGE FIRE SPREAD...SEE FIRE WX SECTION BELOW FOR FURTHER DETAILS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 326 PM CDT MON APR 11 2016 WEDNESDAY AND THURSDAY...TRANSITORY UPPER RIDGE AXIS LOCATED OVER THE NRN HIGH PLAINS WILL SLIDE EWD WEDNESDAY INTO THE MIDWEST AS THE UPPER LOW LOCATED OVER THE SRN PLAINS ALSO SLIDES EWD INTO THE LOWER MISSISSIPPI VALLEY. AS THIS OCCURS...AMPLIFICATION OF THE UPPER PATTERN WILL INCREASE AS THE NEXT PV ANOMALY AND ASSOCIATED HEIGHT FALLS APPROACH THE WEST COAST. WEAK HEIGHT FALLS ASSOCIATED WITH A LEAD SHORT WAVE EMBEDDED IN THE NRN STREAM WILL DEVELOP IN THE NRN ROCKIES AND EMERGE OVER THE NRN HIGH PLAINS BY WED LATE AFTERNOON AND EVENING AND DRAG A WEAK SFC FRONT ACROSS THE NRN PLAINS WED NIGHT. FORCING ALONG THE FRONT IS WEAK HOWEVER A GOOD LLJ DEVELOPS FROM THE SRN PLAINS THROUGH THE CENTRAL HIGH PLAINS...AHEAD OF THE FRONT. THIS WILL BE THE START OF DECENT MOISTURE ADVECTION...THOUGH INITIALLY MOISTURE WILL REMAIN MEAGER AS THE SFC HIGH MOVING INTO THE MIDWEST WAS ASSOCIATED WITH VERY DRY LEVEL AIR. HOWEVER...IN CONNECTION WITH THE LLJ...WEAK INSTABILITY DEVELOPS JUST AHEAD OF THE FRONT WED NIGHT AND MODELS HINT AT THE POSSIBILITY OF ELEVATED DEVELOPMENT WED NIGHT. HAVE INCLUDED ONLY SLIGHT CHANCES FOR THIS POTENTIAL SINCE FORCING REMAINS WEAK AS UPPER HEIGHT FALLS QUICKLY BECOME DISPLACED FROM THE BETTER MID LEVEL TEMP GRADIENT. THERMAL RIDGE ALSO DEVELOPS IN THE HIGH PLAINS AND SHOULD PUSH AFTERNOON TEMPS WELL ABOVE AVERAGE WED AFTERNOON. LOW TEMPS WILL ALSO BE ABOVE AVE. BETTER POTENTIAL FOR PRECIP COMES THURSDAY NIGHT AS THE LONG WAVE TROUGH MOVES INLAND AND UPPER HEIGHT FALLS OVERSPREAD THE GREAT BASIN REGION. WITH THE BUILDING RIDGE ACROSS THE GREAT LAKES STRONG SWRLY FLOW ALOFT DEVELOPS ACROSS THE ROCKIES AND INTO THE NRN HIGH PLAINS. BECAUSE OF THE TERRAIN INFLUENCE A SFC LOW PREFERENTIALLY DEVELOPS ACROSS ERN WY WITH ATTENDANT SFC TROUGH EXTENDING SWD ADJACENT TO THE LEE OF THE ROCKIES. NOTABLE LOW LEVEL THETA-E GRADIENT DEVELOPS FROM SWRN KS INTO THE WRN TX PANHANDLE MARKING THE TRANSITION BETWEEN INCREASING MOISTURE ASSOCIATED WITH THE SRLY LOW LEVEL FLOW AHEAD OF THE WRN STATES TROF...AND DRIER AIR ADVECTED OFF THE HIGHER PLATEAU IN THE WEST. BEST HEIGHT FALLS AND LARGE SCALE FORCING EXISTS ACROSS THE CENTRAL ROCKIES BY THURSDAY AFTERNOON...BUT ALSO INDUCES BETTER LOW LEVEL FORCING IN THE WARM AND MOIST SECTOR AHEAD OF THE DRYLINE /THETA-E GRADIENT/. CONVECTION INITIALLY DEVELOPS IN WRN KS BUT BECAUSE OF THE STRONG LOW LEVEL FLOW WILL SPREAD INTO SRN AND CENTRAL NEB OVERNIGHT THURSDAY INTO EARLY FRIDAY MORNING. THURSDAY AFTERNOON FCST WILL REMAIN DRY AT THIS TIME SINCE BEST LOW LEVEL FORCING REMAINS WEST AND SOUTH OF THE AREA DURING THE DAY. ATMOSPHERIC PW VALUES DO APPROACH THREE QUARTERS OF AN INCH IN THE SWRN PART OF NEB THURSDAY NIGHT WHICH IS WITHIN A TENTH OF AN INCH OF THE MAX FOR THE DATE...BUT RESULTING QPF WILL BE PRIMARILY EAST OF HIGHWAY 83 AS MENTIONED BY PREVIOUS SHIFTS. TEMPS AGAIN WILL BE ABOVE AVE FOR THE TIME OF YEAR ASSUMING HIGH LEVEL CLOUDINESS DOES NOT DEVELOP WHICH AT THIS TIME DOES NOT LOOK LIKE IT WILL. FOR FRIDAY THROUGH THE WEEKEND...THE WRN STATES UPPER TROUGH AND LOW PRESSURE SYSTEM WILL STALL AND EVENTUALLY FILL AS THE UPPER HIGH ACROSS THE GREAT LAKES REMAINS IN PLACE AND EXPANDS. THIS WILL EVENTUALLY DRAW THE UPPER LOW NWD LATE IN THE WEEKEND AS IT WEAKENS AND WILL KEEP THE WET PATTERN IN PLACE ACROSS WESTERN AND NORTH CENTRAL NEB. LAYER PW VALUES REMAIN CLOSE TO MAX VALUES FOR THE TIME OF YEAR INDICATING THE ANOMALOUSLY WET CHARACTER OF THE SYSTEM. WHAT ALSO BECOMES INTERESTING IS THAT THE SFC FEATURES MOVE ONLY VERY SLOWLY DUE TO THE OVERALL LACK OF PROGRESSION EWD OF THE ENTIRE SYSTEM. THEREFORE RAINFALL VALUES COULD BE QUITE DECENT THROUGH THE WEEKEND. THE RAIN AND CLOUDINESS WILL HOLD TEMPS DOWN CLOSER TO AVERAGE OR BELOW THROUGH THE WEEKEND. LOW TEMPS WILL DROP INTO THE 30S BUT AS OF NOW NOT EXPECTING A MIX WITH SNOW AS LOW LEVEL TEMPS STAY JUST A BIT TOO WARM...ALTHOUGH AS BETTER DETAILS OF THIS IMPENDING SYSTEM BECOME AVAILABLE THAT MAY CHANGE IN PORTIONS OF THE PANHANDLE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1150 PM CDT MON APR 11 2016 CLEAR SKIES TONIGHT WITH EASTERLY WINDS BECOMING SOUTHERLY AND INCREASING TUESDAY MORNING. WINDS SOUTHERLY AND GUSTY TO 30 MPH TUESDAY AFTERNOON. VISUAL FLIGHT RULES EXPECTED. && .FIRE WEATHER... ISSUED AT 326 PM CDT MON APR 11 2016 MODIFIED POLAR HIGH PRESSURE WILL BUILD EAST TOWARD THE OHIO VALLEY ON TUESDAY. AS THIS OCCURS A SURFACE TROUGH WILL DEEPEN TO THE LEE OF THE ROCKIES AND MOVE EAST OUT ONTO THE HIGH PLAINS. BETWEEN THESE FEATURES THE SFC PRESSURE GRADIENT WILL INCREASE...ALLOWING FOR GUSTY CONDITIONS /30 MPH OR GREATER/ ACROSS MUCH OF CENTRAL SANDHILLS AND NORTH CENTRAL NEBRASKA TUESDAY AFTERNOON. THE ANTECEDENT AIRMASS IS QUITE DRY AS MOS GUIDANCE INDICATES SUB 25F TD/S ACROSS NORTHEASTERN PORTIONS OF FIRE ZONE 209 THROUGH THE MORNING HOURS. BUT...AS THE SOUTHERLY FLOW INCREASES...TD/S WILL INCREASE SLOWLY INTO THE AFTERNOON. THE CONCERN IS THAT THE LOWER TROPOSPHERIC FLOW IS SOUTHWESTERLY...WHICH WHEN CONSIDERING THE DOWNSLOPING COMPONENT...THE MODELS MAY BE TOO AMBITIOUSLY HIGH WITH THE PROJECTED VALUES. THE TD FORECAST FOR TUESDAY EMPLOYED A BLEND OF THE LOWEST MOS GUIDANCE WITH THE PREVIOUS FORECAST AND THE 11.12Z WRF-ARW TO ACHIEVE A MODEL PREDICTED "WORST-CASE" SCENARIO WITH RH. AT THAT HOWEVER...ONLY LOCALIZED RH READINGS OF 23% ARE SEEN FOR A COUPLE HOURS OVER CENTRAL AND NORTHERN PORTIONS OF ZONE 209. GIVEN THE MARGINALITY OF THE EVENT...WE WILL NOT ISSUE A RED FLAG WARNING WITH THE AFTERNOON FORECAST PACKAGE. TEMPERATURES CONTINUE TO WARM THROUGH THURSDAY...WITH THE POTENTIAL OF WIDESPREAD MID TO UPPER 70S ACROSS MUCH OF THE FORECAST AREA WEDNESDAY AND THURSDAY. LOCALIZED AREAS OF CRITICALLY LOW RH ARE POSSIBLE WITH THESE WARM TEMPERATURES. WILL NEED TO MONITOR THURSDAY AS AN UPPER LEVEL RIDGE BUILDS EAST OF THE CWA AND SOUTHERLY WINDS STRENGTHEN ACROSS PLAINS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JACOBS LONG TERM...STOPPKOTTE AVIATION...POWER FIRE WEATHER...JACOBS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
133 PM EDT TUE APR 12 2016 .SYNOPSIS... SHOWERS AND A FEW THUNDERSTORMS WILL OCCUR AHEAD OF A COLD FRONT WHICH WILL MOVE ACROSS THE AREA TONIGHT. HIGH PRESSURE WILL EXPAND SOUTHWARD BEGINNING WEDNESDAY AND THEN INTO THE WEEKEND... PERSISTING INTO EARLY NEXT WEEK. LOW PRESSURE TRACKING ACROSS THE SOUTHEAST STATES MAY AFFECT THE COASTAL CAROLINAS THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...RADAR TRENDS INDICATING THAT LIFT ASSOCIATED WITH THE FIRST SHORTWAVE IS WANING AS THE REMAINING RAIN IS DOING THE SAME. LATEST RUNS OF THE HRRR SHOW THAT AFTER A BREAK THAT LIGHT SHOWERS WILL FILL BACK IN THIS AFTERNOON AND EVENING AS THE COLD FRONT AND NEXT UPPER VORT APPROACH, THOUGH THE LATTER REALLY APPEARS TO WEAKEN AS IT APPROACHES THE AREA. WHEREAS THE HRRR SEEMS TO THINK BEST RAIN CHANCES AND QPF OVER SC THE 12Z WRF HAS A MORE NORTHWARD BIAS. MAY LOWER HIGHS JUST A FEW DEGREES SINCE SO FAR VIS SAT IMAGERY SHOWS THAT WE MAY BE HARD PRESSED TO SEE ANY BREAKS IN THE CLOUDS. GIVEN THAT THE FRONT LOOKS A LITTLE SLOWER AND WE REMAIN IN THE HIGHER DEWPOINT AIR AREA-WIDE WILL NOT TRY TO SHOW MUCH OF A DISTINCTION THOUGH THE VORT INTERACTING WITH THE FRONT MAY ARGUE FOR THE WRF IDEA. AS OF 600 AM TUESDAY...SHOWERS COVERED MOST OF THE FORECAST AREA AT DAYBREAK AND WILL CONTINUE TO EXPAND TO THE COAST THIS MORNING. A LEAD SHORTWAVE NEAR THE SAVANNAH RIVER WILL LIFT NE ACROSS THE EASTERN CAROLINAS THIS MORNING. A SECOND SHORTWAVE IS PROGGED TO SIGNIFICANTLY DAMPEN AS IT MOVES ACROSS THE AREA THIS EVE... COINCIDENT WITH A COLD FRONT. STILL LOOKS LIKE A HEALTHY DOSE OF RAINFALL...BUT NOTHING HEAVY. FORECAST THINKING REMAINS ESSENTIALLY UNCHANGED WITH THE RISK OF STRONG THUNDERSTORMS VERY LOW GIVEN THE LACK OF MEANINGFUL INSTABILITY AND WILL ONLY INCLUDE SHOWERS WITH ISOLATED AFTERNOON THUNDERSTORMS. MIXED LAYER CAPE VALUES STRUGGLE TO REACH 300 J/KG AND THIS IS MAINLY ACROSS THE FAR SOUTHERN PORTIONS OF THE FORECAST AREA. STILL 0-6 KM BULK SHEAR VALUES DO REACH NEAR 40 KT WHILE MID- LEVEL LAPSE RATES REACH 7 DEG C/KM AS COLDER AIR ARRIVES IN THE MID LEVELS LATER TODAY. OMEGA FIELDS ARE NOT EXPECTED TO BE AS HEALTHY AS PREVIOUSLY FORECAST...10-12 MICROBARS/SECOND AND THIS MAY BE SIGNALING LESSER RAINFALL OVERALL. IMPRESSIVE AND DEEP MOISTURE RETURN REMAINS WITH PRECIPITABLE WATER VALUES REACHING 1.5 INCHES...BUT THE SURGE IS BRIEF. WILL RAMP POPS TO CATEGORICAL THIS MORNING AND THEN SHOW A DECREASING TREND LATER TODAY AND THIS EVE AS DRIER AIR WORKS IN BEHIND THE FRONT ON DEVELOPING BRISK NE WINDS. BY WED MORNING...THERE IS ONLY A SLIGHT CHANCE OF MEASURABLE RAINFALL AND THEN ONLY ALONG THE IMMEDIATE COAST. WE ARE FORECASTING RAINFALL AMOUNTS MAINLY NEAR A HALF INCH AS ROBUST CONVECTION ALONG THE GULF COAST MAY ULTIMATELY LIMIT NORTHWARD EXTENT OF HEAVIER RAINFALL AMOUNTS. THICK CLOUD COVER SHOULD MAKE FOR A COOLER DAY AS COMPARED TO MON...UPPER 60S TO LOWER 70S. LOWS TONIGHT WILL BE IN THE UPPER 40S TO MID 50S...WARMEST ACROSS THE FAR SOUTHERN ZONES WHERE THE COOL NE SURGE WILL ARRIVE LATEST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 AM TUESDAY...A COLD FRONT WILL BE OFFSHORE PRIOR TO THE START OF THE PERIOD. A STRONG AREA OF HIGH PRESSURE TO THE N WILL EXPAND SOUTHWARD ACROSS THE CAROLINAS...TAKING ON A WEDGE- LIKE CONFIGURATION WITH TIME. MEANTIME...A SERIES OF WAVES OF LOW PRESSURE WILL MOVE ALONG THE OFFSHORE BOUNDARY...DRAPED TO OUR E AND S. THE MODELS SEEM TO BE COMING TO A DRIER CONSENSUS DURING THIS FORECAST PERIOD WITH THE EUROPEAN BEING THE LAST TO COME ABOARD. THUS...HAVE DECIDED TO KEEP POPS BELOW THRESHOLD DURING THIS TIME WITH THE POSSIBLE EXCEPTION OF FIRST THING WED MORNING. ON WED...MODEL SOUNDINGS ARE SHOWING VERY DRY AIR IN THE MID AND UPPER LEVELS OF THE COLUMN AND DRY AIR IN THE LOWEST PORTION OF THE COLUMN. HOWEVER...A LAYER OF GOOD MOISTURE DOES HANG ON IN THE 4-6 KFT LAYER...ESPECIALLY ACROSS FAR SOUTHERN AND COASTAL PORTIONS OF THE FORECAST AREA. THEN ON THU...THERE MAY BE MORE MID AND HIGH CLOUDS AROUND. COOL ADVECTION ON BRISK NE WINDS AND PARTLY TO MOSTLY CLOUDY SKIES WILL NOT MAKE IT FEEL ALL THAT APRIL LIKE. HIGHS WILL BE IN THE LOWER TO MIDDLE 60S. LOWS WILL BE MAINLY IN THE MID AND UPPER 40S. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 330 AM TUESDAY...STILL SOME INCONSISTENCIES WITH MODELS FOR EXTENDED PERIOD BUT OVERALL FEATURES ARE SIMILAR. THE FOCUS STILL REMAINS ON THE PESKY LOW OVER TENNESSEE WITH STRUNG OUT VORTICITY RUNNING EAST ACROSS THE CAROLINAS TO SHORTWAVE OVER THE ATLANTIC. AT THE SAME TIME HIGH PRESSURE WILL EXTEND DOWN INTO THE CAROLINAS FROM THE DISTANT NORTH. ECMWF CONTINUES TO BE SLIGHTLY FARTHER NORTH WITH CLOUDS AND PCP REACHING INTO THE AREA ON FRI WHILE THE GFS KEEPS IT JUST SOUTH. WITH UNCERTAINTY PERSISTING...WILL CARRY SOME LOW END POPS BASICALLY ALONG COAST AND EAST OF I95. GFS HAS BECOME MORE OPTIMISTIC WITH CLOUD COVER AND THEREFORE WILL SHOW A DIMINISHING TREND AS WELL. LOOKS LIKE ENOUGH DRIER AIR MAY MIX DOWN TO ERODE ANY POTENTIAL FOR LOWER CLOUDS. OVERALL CONFIDENCE IS GROWING AS BOTH ECMWF AND GFS TEND TOWARD A DRIER SOLUTION. OTHERWISE A HIGHLY AMPLIFIED BLOCKING PATTERN TAKES SHAPE WITH RIDGE AXIS HOLDING JUST WEST OF AREA KEEPING A DEEP N-NE FLOW FRI THROUGH EARLY NEXT WEEK. MAY SEE FAIRLY STIFF NORTHERLY WINDS MAINLY ALONG THE COAST...AS GRADIENT REMAINS PINCHED BETWEEN LOW WELL OFF SHORE AND HIGH BUILDING DOWN FROM THE NORTH. EXPECT COOLER WEATHER TO START WITH GRADUAL WARMING THROUGH THE WEEKEND AS RIDGE BUILDS AND H5 HEIGHTS RISE WITH INCREASING SUNSHINE. THE DRY AIR WILL KEEP LOWER DEWPOINTS AND EXPECT OVERNIGHT LOWS TO DROP DOWN INTO THE 40S WITH DAYTIME HIGHS TRYING TO REACH TOWARD 70. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...LIGHT RAIN WITH A FEW EMBEDDED SHOWERS WILL CONTINUE FOR THE NEXT SEVERAL HOURS ACROSS THE EASTERN CAROLINAS. THIS RAIN IS GENERALLY FALLING FROM A VFR CLOUD CEILING BETWEEN 5 AND 9 THOUSAND FEET. MOISTURE COLLECTING NEAR THE SURFACE SHOULD SEED THE FORMATION OF LOWER STRATUS WITH CEILINGS IN THE 700-1500 FOOT RANGE BECOMING MORE COMMON...ESPECIALLY ALONG THE COAST. ONE FINAL WAVE OF SHOWERS...SOME POSSIBLY MODERATE TO HEAVY...SHOULD DEVELOP ACROSS CENTRAL SOUTH CAROLINA SHORTLY AND WILL MOVE WEST TO EAST ACROSS OUR AREA BETWEEN 21Z-01Z. A SURFACE COLD FRONT NOW DIPPING SOUTH THROUGH NORTHERN NORTH CAROLINA WILL ARRIVE WITH WINDS TURNING NORTHERLY. HOWEVER THE REAL SURGE OF COOLER DRIER AIR SHOULDN`T ARRIVE UNTIL 04-05Z AT WHICH POINT SURFACE WINDS WILL INCREASE TO 12G19 FROM THE NORTH...WITH CEILINGS IMPROVING TO VFR. EXTENDED OUTLOOK...VFR CONDITIONS ARE EXPECTED TO DEVELOP LATE TONIGHT AND PERSIST INTO SUNDAY. MVFR CONDITIONS MAY DEVELOP SATURDAY INTO SATURDAY NIGHT AS WEAK LOW PRESSURE MOVES ACROSS THE GULF COAST. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...NO CHANGES TO THE FORECAST THINKING AT THIS TIME. MAY SLOW THE SENSE OF TIMING WITH REGARDS TO THE FRONT IF MORE GUIDANCE COMES IN SHOWING THIS. WRF SHOWS THE INITIAL WIND SHIFT PUSHING THROUGH 00-03Z BUT THE ACTUAL COOL SURGE AND WIND INCREASE ABOUT 3 HOURS LATER. ANY TWEAKS TO THE FORECAST WILL LIKELY BE MINIMAL. AS OF 600 AM TUESDAY...A COLD FRONT WILL APPROACH FROM THE NW TODAY. THIS FRONT WILL MOVE ACROSS THE WATERS THIS EVE...SHIFTING SW WINDS OF 10 TO 15 KT TO NE. A GOOD SURGE WILL QUICKLY OVERTAKE THE WATERS FROM N TO S WITH WIND SPEEDS INCREASING TO 20 TO 25 KT OVERNIGHT. SEAS WILL BE 2 TO 3 FT INTO THIS EVE...INCREASING TO 3 TO 5 FT OVERNIGHT INTO WED MORNING. SHOWERS AND SOME THUNDERSTORMS WILL BE MOST NUMEROUS LATER THIS MORNING AND INTO THIS EVE. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 AM TUESDAY....PERSISTENT NE FLOW THROUGH THE PERIOD. STRONG HIGH PRESSURE WILL BE CENTERED N OF THE AREA THROUGH THE PERIOD...WITH A WEDGE-LIKE CONFIGURATION DEVELOPING. A COLD FRONT WILL RESIDE OFFSHORE AND DRAPED TO OUR S. A SERIES OF WEAK WAVES OF LOW PRESSURE WILL MOVE ALONG THE BOUNDARY. THE PRESSURE DIFFERENCE BETWEEN THE HIGH TO NORTH AND THIS TROUGH WILL BE ENOUGH TO BRING SMALL CRAFT ADVISORY CONDITIONS TO THE WATERS THROUGH THE PERIOD. WIND SPEEDS WILL BE UP TO 20 TO 25 KT AND SEAS UP TO 5 TO 7 FT. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 330 AM TUESDAY...A NORTHEAST FLOW OF 15-20 KNOTS WILL PERSIST FRI INTO THE WEEKEND AS HIGH PRESSURE EXPANDS SOUTHWARD INTO THE WATERS. PERSISTENT STIFF NORTHEAST WINDS WILL MAINTAIN AN EXTENDED PERIOD OF SMALL CRAFT CONDITIONS CONTINUING ON FRI INTO THE WEEKEND...WITH SEAS UP TO 6 TO 7 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY FOR AMZ250-252-254-256. && $$ SYNOPSIS... NEAR TERM...MBB/RJD SHORT TERM...RJD LONG TERM...RGZ AVIATION...TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT TUE APR 12 2016 .SYNOPSIS... SHOWERS AND A FEW THUNDERSTORMS WILL OCCUR AHEAD OF A COLD FRONT WHICH WILL MOVE ACROSS THE AREA TONIGHT. HIGH PRESSURE WILL EXPAND SOUTHWARD BEGINNING WEDNESDAY AND THEN INTO THE WEEKEND... PERSISTING INTO EARLY NEXT WEEK. LOW PRESSURE TRACKING ACROSS THE SOUTHEAST STATES MAY AFFECT THE COASTAL CAROLINAS THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...RADAR TRENDS INDICATING THAT LIFT ASSOCIATED WITH THE FIRST SHORTWAVE IS WANING AS THE REMAINING RAIN IS DOING THE SAME. LATEST RUNS OF THE HRRR SHOW THAT AFTER A BREAK THAT LIGHT SHOWERS WILL FILL BACK IN THIS AFTERNOON AND EVENING AS THE COLD FRONT AND NEXT UPPER VORT APPROACH, THOUGH THE LATTER REALLY APPEARS TO WEAKEN AS IT APPROACHES THE AREA. WHEREAS THE HRRR SEEMS TO THINK BEST RAIN CHANCES AND QPF OVER SC THE 12Z WRF HAS A MORE NORTHWARD BIAS. MAY LOWER HIGHS JUST A FEW DEGREES SINCE SO FAR VIS SAT IMAGERY SHOWS THAT WE MAY BE HARD PRESSED TO SEE ANY BREAKS IN THE CLOUDS. GIVEN THAT THE FRONT LOOKS A LITTLE SLOWER AND WE REMAIN IN THE HIGHER DEWPOINT AIR AREA-WIDE WILL NOT TRY TO SHOW MUCH OF A DISTINCTION THOUGH THE VORT INTERACTING WITH THE FRONT MAY ARGUE FOR THE WRF IDEA. AS OF 600 AM TUESDAY...SHOWERS COVERED MOST OF THE FORECAST AREA AT DAYBREAK AND WILL CONTINUE TO EXPAND TO THE COAST THIS MORNING. A LEAD SHORTWAVE NEAR THE SAVANNAH RIVER WILL LIFT NE ACROSS THE EASTERN CAROLINAS THIS MORNING. A SECOND SHORTWAVE IS PROGGED TO SIGNIFICANTLY DAMPEN AS IT MOVES ACROSS THE AREA THIS EVE... COINCIDENT WITH A COLD FRONT. STILL LOOKS LIKE A HEALTHY DOSE OF RAINFALL...BUT NOTHING HEAVY. FORECAST THINKING REMAINS ESSENTIALLY UNCHANGED WITH THE RISK OF STRONG THUNDERSTORMS VERY LOW GIVEN THE LACK OF MEANINGFUL INSTABILITY AND WILL ONLY INCLUDE SHOWERS WITH ISOLATED AFTERNOON THUNDERSTORMS. MIXED LAYER CAPE VALUES STRUGGLE TO REACH 300 J/KG AND THIS IS MAINLY ACROSS THE FAR SOUTHERN PORTIONS OF THE FORECAST AREA. STILL 0-6 KM BULK SHEAR VALUES DO REACH NEAR 40 KT WHILE MID- LEVEL LAPSE RATES REACH 7 DEG C/KM AS COLDER AIR ARRIVES IN THE MID LEVELS LATER TODAY. OMEGA FIELDS ARE NOT EXPECTED TO BE AS HEALTHY AS PREVIOUSLY FORECAST...10-12 MICROBARS/SECOND AND THIS MAY BE SIGNALING LESSER RAINFALL OVERALL. IMPRESSIVE AND DEEP MOISTURE RETURN REMAINS WITH PRECIPITABLE WATER VALUES REACHING 1.5 INCHES...BUT THE SURGE IS BRIEF. WILL RAMP POPS TO CATEGORICAL THIS MORNING AND THEN SHOW A DECREASING TREND LATER TODAY AND THIS EVE AS DRIER AIR WORKS IN BEHIND THE FRONT ON DEVELOPING BRISK NE WINDS. BY WED MORNING...THERE IS ONLY A SLIGHT CHANCE OF MEASURABLE RAINFALL AND THEN ONLY ALONG THE IMMEDIATE COAST. WE ARE FORECASTING RAINFALL AMOUNTS MAINLY NEAR A HALF INCH AS ROBUST CONVECTION ALONG THE GULF COAST MAY ULTIMATELY LIMIT NORTHWARD EXTENT OF HEAVIER RAINFALL AMOUNTS. THICK CLOUD COVER SHOULD MAKE FOR A COOLER DAY AS COMPARED TO MON...UPPER 60S TO LOWER 70S. LOWS TONIGHT WILL BE IN THE UPPER 40S TO MID 50S...WARMEST ACROSS THE FAR SOUTHERN ZONES WHERE THE COOL NE SURGE WILL ARRIVE LATEST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 AM TUESDAY...A COLD FRONT WILL BE OFFSHORE PRIOR TO THE START OF THE PERIOD. A STRONG AREA OF HIGH PRESSURE TO THE N WILL EXPAND SOUTHWARD ACROSS THE CAROLINAS...TAKING ON A WEDGE- LIKE CONFIGURATION WITH TIME. MEANTIME...A SERIES OF WAVES OF LOW PRESSURE WILL MOVE ALONG THE OFFSHORE BOUNDARY...DRAPED TO OUR E AND S. THE MODELS SEEM TO BE COMING TO A DRIER CONSENSUS DURING THIS FORECAST PERIOD WITH THE EUROPEAN BEING THE LAST TO COME ABOARD. THUS...HAVE DECIDED TO KEEP POPS BELOW THRESHOLD DURING THIS TIME WITH THE POSSIBLE EXCEPTION OF FIRST THING WED MORNING. ON WED...MODEL SOUNDINGS ARE SHOWING VERY DRY AIR IN THE MID AND UPPER LEVELS OF THE COLUMN AND DRY AIR IN THE LOWEST PORTION OF THE COLUMN. HOWEVER...A LAYER OF GOOD MOISTURE DOES HANG ON IN THE 4-6 KFT LAYER...ESPECIALLY ACROSS FAR SOUTHERN AND COASTAL PORTIONS OF THE FORECAST AREA. THEN ON THU...THERE MAY BE MORE MID AND HIGH CLOUDS AROUND. COOL ADVECTION ON BRISK NE WINDS AND PARTLY TO MOSTLY CLOUDY SKIES WILL NOT MAKE IT FEEL ALL THAT APRIL LIKE. HIGHS WILL BE IN THE LOWER TO MIDDLE 60S. LOWS WILL BE MAINLY IN THE MID AND UPPER 40S. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 330 AM TUESDAY...STILL SOME INCONSISTENCIES WITH MODELS FOR EXTENDED PERIOD BUT OVERALL FEATURES ARE SIMILAR. THE FOCUS STILL REMAINS ON THE PESKY LOW OVER TENNESSEE WITH STRUNG OUT VORTICITY RUNNING EAST ACROSS THE CAROLINAS TO SHORTWAVE OVER THE ATLANTIC. AT THE SAME TIME HIGH PRESSURE WILL EXTEND DOWN INTO THE CAROLINAS FROM THE DISTANT NORTH. ECMWF CONTINUES TO BE SLIGHTLY FARTHER NORTH WITH CLOUDS AND PCP REACHING INTO THE AREA ON FRI WHILE THE GFS KEEPS IT JUST SOUTH. WITH UNCERTAINTY PERSISTING...WILL CARRY SOME LOW END POPS BASICALLY ALONG COAST AND EAST OF I95. GFS HAS BECOME MORE OPTIMISTIC WITH CLOUD COVER AND THEREFORE WILL SHOW A DIMINISHING TREND AS WELL. LOOKS LIKE ENOUGH DRIER AIR MAY MIX DOWN TO ERODE ANY POTENTIAL FOR LOWER CLOUDS. OVERALL CONFIDENCE IS GROWING AS BOTH ECMWF AND GFS TEND TOWARD A DRIER SOLUTION. OTHERWISE A HIGHLY AMPLIFIED BLOCKING PATTERN TAKES SHAPE WITH RIDGE AXIS HOLDING JUST WEST OF AREA KEEPING A DEEP N-NE FLOW FRI THROUGH EARLY NEXT WEEK. MAY SEE FAIRLY STIFF NORTHERLY WINDS MAINLY ALONG THE COAST...AS GRADIENT REMAINS PINCHED BETWEEN LOW WELL OFF SHORE AND HIGH BUILDING DOWN FROM THE NORTH. EXPECT COOLER WEATHER TO START WITH GRADUAL WARMING THROUGH THE WEEKEND AS RIDGE BUILDS AND H5 HEIGHTS RISE WITH INCREASING SUNSHINE. THE DRY AIR WILL KEEP LOWER DEWPOINTS AND EXPECT OVERNIGHT LOWS TO DROP DOWN INTO THE 40S WITH DAYTIME HIGHS TRYING TO REACH TOWARD 70. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...TERMINALS ARE PREDOMINATELY VFR THIS MORNING...BUT VSBYS HAVE DROPPED AS LOW AS MVFR AT KFLO/KLBT IN MAINLY LIGHT RAIN/BR IN ASSOCIATION WITH AN AREA OF PRECIPITATION OVER THOSE TERMINALS. THIS AREA OF PRECIPITATION IS SHIFTING EAST. THERE COULD BE LESS PRECIPITATION AT THE TERMINALS AROUND MID- MORNING...BUT IN GENERAL SHOWERS ARE LIKELY TODAY...WITH A LOW CHANCE OF ISOLATED THUNDERSTORMS THIS AFTERNOON AS A COLD FRONT MOVES SOUTH. MVFR WILL BECOME INCREASING LIKELY AT KFLO/KLBT THIS MORNING WITH THE BEST CHANCE OF IFR AT KLBT. COASTAL TERMINALS WILL BE VFR...TEMPO MVFR DUE TO PRECIPITATION. AFTER THE FRONT MOVES THROUGH IN THE AFTERNOON THE THREAT OF THUNDERSTORMS SHOULD ABATE...BUT THERE WILL BE A BETTER CHANCE OF IFR. WINDS WILL BE VEERING FROM S-SW TO THE NW WITH THE FRONT. AS HIGH PRESSURE BUILDS IN...WINDS WILL INCREASE SIGNIFICANTLY THIS EVENING. CIGS WILL IMPROVE INITIALLY TO VFR AT KLBT/KFLO LATE AFTERNOON/ EARLY EVENING...IN THE LATE EVENING AT THE COASTAL TERMINALS. EXTENDED OUTLOOK...MVFR/IFR CONDITIONS ARE POSSIBLE LATE TONIGHT INTO WEDNESDAY IN THE WAKE OF A COLD FRONT. VFR CONDITIONS ARE EXPECTED TO DEVELOP WEDNESDAY AND PERSIST INTO SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...NO CHANGES TO THE FORECAST THINKING AT THIS TIME. MAY SLOW THE SENSE OF TIMING WITH REGARDS TO THE FRONT IF MORE GUIDANCE COMES IN SHOWING THIS. WRF SHOWS THE INITIAL WIND SHIFT PUSHING THROUGH 00-03Z BUT THE ACTUAL COOL SURGE AND WIND INCREASE ABOUT 3 HOURS LATER. ANY TWEAKS TO THE FORECAST WILL LIKELY BE MINIMAL. AS OF 600 AM TUESDAY...A COLD FRONT WILL APPROACH FROM THE NW TODAY. THIS FRONT WILL MOVE ACROSS THE WATERS THIS EVE...SHIFTING SW WINDS OF 10 TO 15 KT TO NE. A GOOD SURGE WILL QUICKLY OVERTAKE THE WATERS FROM N TO S WITH WIND SPEEDS INCREASING TO 20 TO 25 KT OVERNIGHT. SEAS WILL BE 2 TO 3 FT INTO THIS EVE...INCREASING TO 3 TO 5 FT OVERNIGHT INTO WED MORNING. SHOWERS AND SOME THUNDERSTORMS WILL BE MOST NUMEROUS LATER THIS MORNING AND INTO THIS EVE. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 AM TUESDAY....PERSISTENT NE FLOW THROUGH THE PERIOD. STRONG HIGH PRESSURE WILL BE CENTERED N OF THE AREA THROUGH THE PERIOD...WITH A WEDGE-LIKE CONFIGURATION DEVELOPING. A COLD FRONT WILL RESIDE OFFSHORE AND DRAPED TO OUR S. A SERIES OF WEAK WAVES OF LOW PRESSURE WILL MOVE ALONG THE BOUNDARY. THE PRESSURE DIFFERENCE BETWEEN THE HIGH TO NORTH AND THIS TROUGH WILL BE ENOUGH TO BRING SMALL CRAFT ADVISORY CONDITIONS TO THE WATERS THROUGH THE PERIOD. WIND SPEEDS WILL BE UP TO 20 TO 25 KT AND SEAS UP TO 5 TO 7 FT. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 330 AM TUESDAY...A NORTHEAST FLOW OF 15-20 KNOTS WILL PERSIST FRI INTO THE WEEKEND AS HIGH PRESSURE EXPANDS SOUTHWARD INTO THE WATERS. PERSISTENT STIFF NORTHEAST WINDS WILL MAINTAIN AN EXTENDED PERIOD OF SMALL CRAFT CONDITIONS CONTINUING ON FRI INTO THE WEEKEND...WITH SEAS UP TO 6 TO 7 FT && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...MBB/RJD SHORT TERM...RJD LONG TERM...RGZ AVIATION...MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
846 PM CDT WED APR 13 2016 .UPDATE... ISSUED AT 837 PM CDT WED APR 13 2016 ANOTHER UPDATE TO BLEND TO OBSERVED RADAR TRENDS THROUGH 0135 UTC AND A 9 MEMBER TIME LAGGED ENSEMBLE OF THE 22-00 UTC HRRR ITERATIONS WHICH CONTINUE TO HAVE A GOOD HANDLE ON THE AREA OF RAIN SHOWERS WITH A FEW WEAK EMBEDDED THUNDERSTORMS AHEAD OF THE SURFACE COLD FRONT. UPDATE ISSUED AT 529 PM CDT WED APR 13 2016 QUICK UPDATE TO BLEND TO OBSERVED RADAR TRENDS THROUGH 2215 UTC AND A TIME LAGGED ENSEMBLE OF THE 19-21 UTC HRRR ITERATIONS WHICH HAS A GOOD HANDLE ON THE ON GOING CONVECTION. WIND GUSTS OF 45 TO 50 MPH ARE POSSIBLE WITH THESE STORMS GIVEN INVERTED V SOUNDINGS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 348 PM CDT WED APR 13 2016 THE LATEST WATER VAPOR IMAGERY SHOWS A DEEP CLOSED LOW APPROACHING THE PACIFIC NORTHWEST. THIS CLOSED LOW WILL SLOWLY SHIFT SOUTHEAST INTO THE GREAT BASIN AND FOUR CORNERS NOW THROUGH SUNDAY. IN DOING SO...A FAVORABLE SOUTHWEST FLOW INTO NORTH DAKOTA WITH A SERIES OF SURFACE LOW PRESSURES AND ASSOCIATED SHORTWAVES PEELING OFF/EJECTING FROM THE MAIN UPPER LOW MENTIONED ABOVE...WILL TRACK ACROSS SOUTHERN AND EASTERN NORTH DAKOTA. APPROXIMATELY THREE SURFACE LOWS AND ASSOCIATED SHORTWAVES WILL PASS ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN WEDNESDAY NIGHT AND SUNDAY. THIS WILL RESULT IN A WET/UNSETTLED PERIOD THROUGH THE WEEKEND. HIGHLIGHT IN THE NEAR TERM (NOW THROUGH WEDNESDAY AFTERNOON) IS THE ONGOING RED FLAG WARNING. VERIFICATION IS UNDERWAY WITH FORECAST AND OBSERVATIONAL DATA SHOWING SUSTAINED WINDS BETWEEN 20 MPH AND 25 MPH ...WITH RELATIVE HUMDITIES BETWEEN 20 AND 25 PERCENT AT THIS TIME. ONE CONCERN IN THE WEST IS INCREASING HIGH/MIDDLE CLOUDS COMING IN FROM EASTERN MONTANA. THIS COULD/MAY DISRUPT THE THREE CONSECUTIVE HOUR VERIFICATION IN SOME SPOTS...AS ADDITIONAL CLOUDS/SHADING MIGHT BE ENOUGH TO HALT OR LIMIT SOLAR INSOLATION AND MIXING NEEDED TO SUSTAIN THE WIND/LOW HUMIDITIES FOR THE TIME NEEDED. HOWEVER WILL KEEP THE WARNING IN TACT UNTIL THIS BECOMES EVIDENT. ALSO MONITORING AREAS JUST EAST OF THE CURRENT RED FLAG WARNING. BELIEVE THIS WILL BE A MARGINAL AREA...BOTH IN TIME AND AREAL COVERAGE INTO THE LATE AFTERNOON...AND THUS WILL HOLD OFF FROM EXPANDING THE CURRENT RED FLAG WARNING AT THIS TIME. FOR THE SHORT TERM PERIOD...TONIGHT THROUGH THURSDAY...FOCUS WILL BE THE PASSAGE OF A COLD FRONT TONIGHT...RESULTING IN A PERIOD OF RAIN SHOWERS AND SOME THUNDERSTORMS. A SURFACE LOW PRESSURE IN WESTERN SOUTH DAKOTA WILL RIDE UP ALONG THE COLD FRONT OVERNIGHT REACHING THE SOUTHERN JAMES RIVER VALLEY BY 12Z THURSDAY AND THEN STALLING OUT DURING THE DAY. THUNDERSTORMS ARE NOT EXPECTED TO REACH SEVERE CRITERIA TONIGHT. BUT EXPECT SOME SHOWERS AND RUMBLING OVERNIGHT ALONG AND AHEAD OF THE COLD FRONT. WITH THE FRONT STALLING OUT THURSDAY IN THE JAMES RIVER VALLEY...CHANCES OF SHOWERS WILL CONTINUE HERE WITH A BREAK/DRY PERIOD ELSEWHERE FOR MOST OF THE AFTERNOON. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 348 PM CDT WED APR 13 2016 HIGHLIGHTS IN THE LONG TERM INCLUDE PERIODS OF RAINSHOWERS AND THUNDERSTORMS WITH WIDESPREAD RAINFALL OF BETWEEN THUNDERSTORMS. RAINFALL TOTALS BETWEEN A HALF INCH TO ONE AND A HALF INCHES LOOKS TO BE A GOOD RANGE ACROSS WESTERN AND CENTRAL NORTH DAKOTA WEDNESDAY NIGHT THROUGH SUNDAY. THURSDAY NIGHT...THE BRIEF BREAK MENTIONED ABOVE WILL COME TO AN END LATE THURSDAY AFTERNOON/EVENING...AS THE NEXT STRONGER SURFACE LOW FOLLOW A NEARLY IDENTICAL PATH...ALBEIT SLOWER. THIS WILL RESULT IN WIDESPREAD RAIN SHOWERS AND SCATTERED THUNDERSTORMS THURSDAY NIGHT THROUGH FRIDAY. ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THURSDAY EVENING/NIGHT AS STRONGER INSTABILITY WILL EXIST WITH THIS NEXT SURFACE LOW AND ASSOCIATED SHORTWAVE TROUGH ALOFT. THUNDERSTORMS ARE FORECAST TO INITIATE IN EASTERN MONTANA LATE THURSDAY AFTERNOON INTO THE EARLY EVENING...THEN SHIFT INTO SOUTHWESTERN NORTH DAKOTA. ANY SURFACED BASE CONVECTION WILL LIKELY TRANSITION TO ELEVATED CONVECTION ACROSS SOUTH CENTRAL AND INTO THE JAMES RIVER VALLEY 06Z-12Z FRIDAY. FRIDAY THROUGH SUNDAY...A WET DAY FRIDAY AS THE AFOREMENTIONED SURFACE LOW RIDES UP ALONG A COLD FRONT ACROSS SOUTH CENTRAL AND INTO THE JAMES RIVER VALLEY. SHOWERS AND SCATTERED THUNDERSTORMS MOSTLY ACROSS CENTRAL NORTH DAKOTA WHICH WILL BE LOCATED NEAREST THE COLD FRONT AND SURFACE LOW. LESS SHOWER ACTIVITY IS FORECAST IN THE WEST. ANOTHER SURFACE IS FORECAST TO PASS ACROSS NORTHEAST SOUTH DAKOTA AND INTO MINNESOTA SATURDAY NIGHT AND SUNDAY RESULTING IN A CHANCE OF SHOWERS MAINLY FAR SOUTH CENTRAL INTO THE JAMES RIVER VALLEY...WITH DRIER CONDITIONS FARTHER WEST AND NORTH. MONDAY THROUGH WEDNESDAY...AS THE CLOSED UPPER LOW WILL SIT AND SPIN ACROSS THE FOUR CORNERS MONDAY THEN BECOME AN OPEN WAVE TUESDAY AND WEDNESDAY BUT REMAIN SOUTH OF NORTH DAKOTA. A REX BLOCK FORMATION DEVELOPS WITH AN UPPER HIGH SITUATED OVER THE UPPER LOW MENTIONED ABOVE. THIS IS FORECAST TO PRODUCE A DRY PERIOD WITH MODERATING TEMPERATURES THROUGH THE PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 837 PM CDT WED APR 13 2016 RAIN SHOWERS WITH POSSIBLY AN EMBEDDED THUNDERSTORM WILL CONTINUE TO IMPACT CENTRAL NORTH DAKOTA LATE THIS EVENING INTO TONIGHT AHEAD OF A COLD FRONT. MVFR CONDITIONS ARE POSSIBLE IN PRECIPITATION. OTHERWISE...VFR CONDITIONS ARE FORECAST FOR THE 00 UTC TAF CYCLE && .FIRE WEATHER... ISSUED AT 348 PM CDT WED APR 13 2016 A RED FLAG WARNING CONTINUES THIS AFTERNOON AND EARLY EVENING OVER THE WESTERN THIRD OF NORTH DAKOTA. THE COMBINATION OF SUSTAINED SOUTHERLY WINDS OF 25 MPH...MINIMUM RELATIVE HUMIDITY AROUND 20 PERCENT AND MAXIMUM TEMPERATURES IN THE MIDDLE 70S WILL CREATE THE CRITICAL FIRE WEATHER CONDITIONS. WINDS WILL ALSO SHIFT TO THE WEST LATE THIS AFTERNOON INTO EARLY EVENING AS A COLD FRONT APPROACHES AND SHIFTS THROUGH. DRY LIGHTNING REMAINS A POSSIBILITY EARLY THIS EVENING. INCREASING MOISTURE AND THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BEGIN WEDNESDAY EVENING AND CONTINUE THROUGH THURSDAY AND FRIDAY. COOLER TEMPERATURES ARE EXPECTED SATURDAY AS THE PRECIPITATION ENDS WITH A MIX OF RAIN AND SNOW ACROSS THE NORTH. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AYD SHORT TERM...KS LONG TERM...KS AVIATION...AYD FIRE WEATHER...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
124 PM EDT TUE APR 12 2016 .SYNOPSIS... COLD FRONT EXITS THIS MORNING...DRIER AIR SINKS SOUTH IN ITS WAKE. HIGH PRESSURE CENTERED TO OUR NORTH AND NORTHEAST...PROVIDES PROLONGED PERIOD OF EAST TO SOUTHEAST FLOW. && .NEAR TERM /THROUGH TONIGHT/... 930 AM UPDATE...SKIES CONTINUE TO CLEAR FROM WEST TO EAST THIS MORNING BEHIND THE FRONT WITH RIDGING BUILDING IN. HAVE UPDATED SKY FORECAST TO REFLECT VISIBLE IMAGERY AND CURRENT OBS/TRENDS ACROSS THE REGION. NO FURTHER UPDATES ARE NEEDED AT THIS TIME. PREVIOUS DISCUSSION... AS OF 600AM THE COLD FRONT HAD PUSHED THROUGH BKW AND EKN. RELIED FAIRLY HEAVILY ON THE HRRR FOR MARCHING THE COLD FRONT AND POPS ACROSS THE REMAINDER OF THE CWA EARLY THIS MORNING. THE COLD FRONT SHOULD BE EXITING TO THE EAST JUST AFTER SUNRISE...HOWEVER FORECAST SOUNDINGS SHOW LOW LEVEL MOISTURE LINGERING ACROSS THE MOUNTAINS. CODED UP SOME DRIZZLE EARLY THIS MORNING ACROSS THE EASTERN HALF OF THE CWA AS THIS MOISTURE GETS SQUEEZED OUT. HIGH PRESSURE MOVES INTO THE GREAT LAKES REGION TODAY...AND CLOUDS WILL GRADUALLY BREAK UP FROM WEST TO EAST. EXPECT A GOOD RADIATIONAL COOLING NIGHT TONIGHT WITH LITTLE TO NO CLOUD COVER. LOWS TONIGHT ARE A BIT TRICKY AS GUIDANCE IS HOVERING ON EITHER SIDE OF FREEZING FOR ALL BUT HIGHEST ELEVATIONS WHICH ARE COLDER. USED LOCALLY PRODUCED MOS BASED ON COOP SITES FOR LOWS TONIGHT. THIS PRODUCT DOES FAIRLY WELL CAPTURING THE COLD SPOTS IN SE OHIO AND NE KENTUCKY. FOR EXAMPLE THIS GUIDANCE GIVING AROUND 30 IN THE LOWER SPOTS OF GREENUP AND CARTER COUNTY KY. WITH THIS IN MIND...CONVERTED THE FREEZE WATCH TO A WARNING...AND ADDED NE KY AND LAWRENCE COUNTY OHIO TO THE MIX. FOR THE COUNTIES ALONG THE OHIO AND TUG FORK...FREEZING TEMPERATURES ARE ONLY EXPECTED AWAY FROM THE RIVERS IN OUTLYING AREAS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... THE HIGH PRESSURE CENTER NEVER SETTLES IN OUR VICINITY BUT RIDGES DOWN THE PIEDMONT FROM ITS CENTER TO OUR NORTHEAST. AS A RESULT... LOW LEVEL FLOW TURNS WEAK EAST AND SOUTHEAST WEDNESDAY NIGHT THROUGH FRIDAY. ENOUGH LOW LEVEL FLOW OVER MOUNTAINS...AND SOUTHERN PLATEAU IN THE VICINITY OF BKW...TO KEEP TEMPERATURES A FEW DEGREES MILDER AT NIGHT...AND A BIT LOWER DURING THE DAY. THE SOUTHERN SYSTEM WEAK CUT OFF OVER THE LOWER MISSISSIPPI VALLEY ON THURSDAY...MAY SPILL SOME HIGH CLOUDS NORTH. THE 00Z NAM WAS MOST AGGRESSIVE WITH SOME DEEPER MOISTURE CREEPING NORTH BY THURSDAY EVENING...INTO OUR SOUTHERN COUNTIES. WILL LEAVE POPS AOB 14 PERCENT IN OUR SOUTHERN COUNTIES. MID/UPPER RIDGE AXIS OVER US WITH WEAK WINDS AT THOSE LEVELS. AFTER THE INITIAL 850 MB WARMING ON WEDNESDAY...TEMPERATURES ALOFT SLOW TO WARM. SO NO BIG JUMP IN HIGH TEMPERATURES FOR THURSDAY AND FRIDAY. AS MENTIONED...TRIED TO HOLD DOWN THE EASTERN SLOPES A BIT ON MAXIMUM TEMPERATURE DUE TO THE WEAK EAST AND SOUTHEAST LOW LEVEL FLOW. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... VAST MAJORITY OF MODELS IN GOOD AGREEMENT. THIS PERIOD LOOKS QUIET WITH A STRENGTHENING UPPER RIDGE OVER THE GREAT LAKES AND OHIO VALLEY FRIDAY...QUICKLY DEVELOPING INTO A STATIONARY UPPER HIGH BY THE WEEKEND. THIS UPPER HIGH OVER OUR AREA WILL HELP FORM A WELL DEFINED OMEGA BLOCK OVER THE CONTINENTAL U.S...WITH ONE UPPER LOW OVER THE SOUTHWEST U.S. AND ANOTHER OFF THE SOUTHEAST U.S. COAST. THIS PATTERN PROTECTS US FROM SOUTHERN STREAM SYSTEMS TRYING TO EJECT OUT OF THE SOUTHWESTERN U.S. UPPER LOW. AS THE HIGH DEVELOPS AT THE SURFACE AND ALOFT...LOOK FOR A WARMING TREND WITH QUITE DRY WEATHER AND ABUNDANT SUNSHINE. FOR THE LOW LANDS...TEMPERATURES WILL WARM FROM THE 60S FRIDAY TO WELL INTO THE 70S BY MONDAY...WITH NIGHT TIME LOWS MOSTLY STAYING ABOVE FREEZING. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... 15Z UPDATE...AS OF 15Z SKIES HAVE CLEARED IN EVERY LOCATION EXCEPT FOR EKN AND BKW. BASED ON THE CURRENT WEST TO EAST PROGRESSION OF STRATUS FIELD...IT SHOULD NOT BE MUCH MORE THAN AN HOUR FOR THOSE SITES TO RISE TO VFR AS WELL AND ALL SITES LOOK TO REMAIN VFR WITH HIGH PRESSURE MOVING OVERHEAD. PREVIOUS DISCUSSION... HIGH PRESSURE IS MOVING OVER THE AREA WITH MOSTLY CLEAR SKIES AND VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. GENERALLY LIGHT NORTHERLY WINDS EXPECTED THROUGH THE TAF PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE...HIGH. ALTERNATE SCENARIOS: NONE 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 H H H H H H H H H H H 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 WEDNESDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR WVZ007>011- 016>020-027>032-039-040. OH...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR OHZ066-067- 075-076-083>087. KY...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR KYZ101>103- 105. VA...NONE. && $$ SYNOPSIS...KTB/JMV/MZ NEAR TERM...MZ/MPK SHORT TERM...KTB LONG TERM...JMV AVIATION...MPK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1107 AM EDT TUE APR 12 2016 .SYNOPSIS... COLD FRONT EXITS THIS MORNING...DRIER AIR SINKS SOUTH IN ITS WAKE. HIGH PRESSURE CENTERED TO OUR NORTH AND NORTHEAST...PROVIDES PROLONGED PERIOD OF EAST TO SOUTHEAST FLOW. && .NEAR TERM /THROUGH TONIGHT/... 930 AM UPDATE...SKIES CONTINUE TO CLEAR FROM WEST TO EAST THIS MORNING BEHIND THE FRONT WITH RIDGING BUILDING IN. HAVE UPDATED SKY FORECAST TO REFLECT VISIBLE IMAGERY AND CURRENT OBS/TRENDS ACROSS THE REGION. NO FURTHER UPDATES ARE NEEDED AT THIS TIME. PREVIOUS DISCUSSION... AS OF 600AM THE COLD FRONT HAD PUSHED THROUGH BKW AND EKN. RELIED FAIRLY HEAVILY ON THE HRRR FOR MARCHING THE COLD FRONT AND POPS ACROSS THE REMAINDER OF THE CWA EARLY THIS MORNING. THE COLD FRONT SHOULD BE EXITING TO THE EAST JUST AFTER SUNRISE...HOWEVER FORECAST SOUNDINGS SHOW LOW LEVEL MOISTURE LINGERING ACROSS THE MOUNTAINS. CODED UP SOME DRIZZLE EARLY THIS MORNING ACROSS THE EASTERN HALF OF THE CWA AS THIS MOISTURE GETS SQUEEZED OUT. HIGH PRESSURE MOVES INTO THE GREAT LAKES REGION TODAY...AND CLOUDS WILL GRADUALLY BREAK UP FROM WEST TO EAST. EXPECT A GOOD RADIATIONAL COOLING NIGHT TONIGHT WITH LITTLE TO NO CLOUD COVER. LOWS TONIGHT ARE A BIT TRICKY AS GUIDANCE IS HOVERING ON EITHER SIDE OF FREEZING FOR ALL BUT HIGHEST ELEVATIONS WHICH ARE COLDER. USED LOCALLY PRODUCED MOS BASED ON COOP SITES FOR LOWS TONIGHT. THIS PRODUCT DOES FAIRLY WELL CAPTURING THE COLD SPOTS IN SE OHIO AND NE KENTUCKY. FOR EXAMPLE THIS GUIDANCE GIVING AROUND 30 IN THE LOWER SPOTS OF GREENUP AND CARTER COUNTY KY. WITH THIS IN MIND...CONVERTED THE FREEZE WATCH TO A WARNING...AND ADDED NE KY AND LAWRENCE COUNTY OHIO TO THE MIX. FOR THE COUNTIES ALONG THE OHIO AND TUG FORK...FREEZING TEMPERATURES ARE ONLY EXPECTED AWAY FROM THE RIVERS IN OUTLYING AREAS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... THE HIGH PRESSURE CENTER NEVER SETTLES IN OUR VICINITY BUT RIDGES DOWN THE PIEDMONT FROM ITS CENTER TO OUR NORTHEAST. AS A RESULT... LOW LEVEL FLOW TURNS WEAK EAST AND SOUTHEAST WEDNESDAY NIGHT THROUGH FRIDAY. ENOUGH LOW LEVEL FLOW OVER MOUNTAINS...AND SOUTHERN PLATEAU IN THE VICINITY OF BKW...TO KEEP TEMPERATURES A FEW DEGREES MILDER AT NIGHT...AND A BIT LOWER DURING THE DAY. THE SOUTHERN SYSTEM WEAK CUT OFF OVER THE LOWER MISSISSIPPI VALLEY ON THURSDAY...MAY SPILL SOME HIGH CLOUDS NORTH. THE 00Z NAM WAS MOST AGGRESSIVE WITH SOME DEEPER MOISTURE CREEPING NORTH BY THURSDAY EVENING...INTO OUR SOUTHERN COUNTIES. WILL LEAVE POPS AOB 14 PERCENT IN OUR SOUTHERN COUNTIES. MID/UPPER RIDGE AXIS OVER US WITH WEAK WINDS AT THOSE LEVELS. AFTER THE INITIAL 850 MB WARMING ON WEDNESDAY...TEMPERATURES ALOFT SLOW TO WARM. SO NO BIG JUMP IN HIGH TEMPERATURES FOR THURSDAY AND FRIDAY. AS MENTIONED...TRIED TO HOLD DOWN THE EASTERN SLOPES A BIT ON MAXIMUM TEMPERATURE DUE TO THE WEAK EAST AND SOUTHEAST LOW LEVEL FLOW. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... VAST MAJORITY OF MODELS IN GOOD AGREEMENT. THIS PERIOD LOOKS QUIET WITH A STRENGTHENING UPPER RIDGE OVER THE GREAT LAKES AND OHIO VALLEY FRIDAY...QUICKLY DEVELOPING INTO A STATIONARY UPPER HIGH BY THE WEEKEND. THIS UPPER HIGH OVER OUR AREA WILL HELP FORM A WELL DEFINED OMEGA BLOCK OVER THE CONTINENTAL U.S...WITH ONE UPPER LOW OVER THE SOUTHWEST U.S. AND ANOTHER OFF THE SOUTHEAST U.S. COAST. THIS PATTERN PROTECTS US FROM SOUTHERN STREAM SYSTEMS TRYING TO EJECT OUT OF THE SOUTHWESTERN U.S. UPPER LOW. AS THE HIGH DEVELOPS AT THE SURFACE AND ALOFT...LOOK FOR A WARMING TREND WITH QUITE DRY WEATHER AND ABUNDANT SUNSHINE. FOR THE LOW LANDS...TEMPERATURES WILL WARM FROM THE 60S FRIDAY TO WELL INTO THE 70S BY MONDAY...WITH NIGHT TIME LOWS MOSTLY STAYING ABOVE FREEZING. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... 15Z UPDATE...AS OF 15Z SKIES HAVE CLEARED IN EVERY LOCATION EXCEPT FOR EKN AND BKW. BASED ON THE CURRENT WEST TO EAST PROGRESSION OF STRATUS FIELD...IT SHOULD NOT BE MUCH MORE THAN AN HOUR FOR THOSE SITES TO RISE TO VFR AS WELL AND ALL SITES LOOK TO REMAIN VFR WITH HIGH PRESSURE MOVING OVERHEAD. PREVIOUS DISCUSSION... COLD FRONT EXITING TO THE EAST LEAVING SOME LOW STRATUS AND DRIZZLE IN ITS WAKE. SOMEWHAT UNCERTAIN HOW LONG IFR WILL LINGER IN BKW BEFORE BREAKING UP AND LIFTING. FORECAST SOUNDINGS ARE PRETTY QUICK TO CLEAR BUT OVERALL...THINGS WILL IMPROVE FROM WEST TO EAST THIS MORNING...WITH VFR EXPECTED FOR THE REMAINDER OF THE TAF PERIOD. GENERALLY LIGHT NORTHERLY WINDS EXPECTED THROUGH THE TAF PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM THIS MORNING THEN HIGH. ALTERNATE SCENARIOS: TIMING IMPROVEMENTS MAY VARY THIS MORNING. 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 H H H H H H H H H H H 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 12Z WEDNESDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR WVZ007>011- 016>020-027>032-039-040. OH...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR OHZ066-067- 075-076-083>087. KY...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR KYZ101>103- 105. VA...NONE. && $$ SYNOPSIS...KTB/JMV/MZ NEAR TERM...MZ/MPK SHORT TERM...KTB LONG TERM...JMV AVIATION...MZ/MPK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
940 AM EDT TUE APR 12 2016 .SYNOPSIS... COLD FRONT EXITS THIS MORNING...DRIER AIR SINKS SOUTH IN ITS WAKE. HIGH PRESSURE CENTERED TO OUR NORTH AND NORTHEAST...PROVIDES PROLONGED PERIOD OF EAST TO SOUTHEAST FLOW. && .NEAR TERM /THROUGH TONIGHT/... 930 AM UPDATE...SKIES CONTINUE TO CLEAR FROM WEST TO EAST THIS MORNING BEHIND THE FRONT WITH RIDGING BUILDING IN. HAVE UPDATED SKY FORECAST TO REFLECT VISIBLE IMAGERY AND CURRENT OBS/TRENDS ACROSS THE REGION. NO FURTHER UPDATES ARE NEEDED AT THIS TIME. PREVIOUS DISCUSSION... AS OF 600AM THE COLD FRONT HAD PUSHED THROUGH BKW AND EKN. RELIED FAIRLY HEAVILY ON THE HRRR FOR MARCHING THE COLD FRONT AND POPS ACROSS THE REMAINDER OF THE CWA EARLY THIS MORNING. THE COLD FRONT SHOULD BE EXITING TO THE EAST JUST AFTER SUNRISE...HOWEVER FORECAST SOUNDINGS SHOW LOW LEVEL MOISTURE LINGERING ACROSS THE MOUNTAINS. CODED UP SOME DRIZZLE EARLY THIS MORNING ACROSS THE EASTERN HALF OF THE CWA AS THIS MOISTURE GETS SQUEEZED OUT. HIGH PRESSURE MOVES INTO THE GREAT LAKES REGION TODAY...AND CLOUDS WILL GRADUALLY BREAK UP FROM WEST TO EAST. EXPECT A GOOD RADIATIONAL COOLING NIGHT TONIGHT WITH LITTLE TO NO CLOUD COVER. LOWS TONIGHT ARE A BIT TRICKY AS GUIDANCE IS HOVERING ON EITHER SIDE OF FREEZING FOR ALL BUT HIGHEST ELEVATIONS WHICH ARE COLDER. USED LOCALLY PRODUCED MOS BASED ON COOP SITES FOR LOWS TONIGHT. THIS PRODUCT DOES FAIRLY WELL CAPTURING THE COLD SPOTS IN SE OHIO AND NE KENTUCKY. FOR EXAMPLE THIS GUIDANCE GIVING AROUND 30 IN THE LOWER SPOTS OF GREENUP AND CARTER COUNTY KY. WITH THIS IN MIND...CONVERTED THE FREEZE WATCH TO A WARNING...AND ADDED NE KY AND LAWRENCE COUNTY OHIO TO THE MIX. FOR THE COUNTIES ALONG THE OHIO AND TUG FORK...FREEZING TEMPERATURES ARE ONLY EXPECTED AWAY FROM THE RIVERS IN OUTLYING AREAS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... THE HIGH PRESSURE CENTER NEVER SETTLES IN OUR VICINITY BUT RIDGES DOWN THE PIEDMONT FROM ITS CENTER TO OUR NORTHEAST. AS A RESULT... LOW LEVEL FLOW TURNS WEAK EAST AND SOUTHEAST WEDNESDAY NIGHT THROUGH FRIDAY. ENOUGH LOW LEVEL FLOW OVER MOUNTAINS...AND SOUTHERN PLATEAU IN THE VICINITY OF BKW...TO KEEP TEMPERATURES A FEW DEGREES MILDER AT NIGHT...AND A BIT LOWER DURING THE DAY. THE SOUTHERN SYSTEM WEAK CUT OFF OVER THE LOWER MISSISSIPPI VALLEY ON THURSDAY...MAY SPILL SOME HIGH CLOUDS NORTH. THE 00Z NAM WAS MOST AGGRESSIVE WITH SOME DEEPER MOISTURE CREEPING NORTH BY THURSDAY EVENING...INTO OUR SOUTHERN COUNTIES. WILL LEAVE POPS AOB 14 PERCENT IN OUR SOUTHERN COUNTIES. MID/UPPER RIDGE AXIS OVER US WITH WEAK WINDS AT THOSE LEVELS. AFTER THE INITIAL 850 MB WARMING ON WEDNESDAY...TEMPERATURES ALOFT SLOW TO WARM. SO NO BIG JUMP IN HIGH TEMPERATURES FOR THURSDAY AND FRIDAY. AS MENTIONED...TRIED TO HOLD DOWN THE EASTERN SLOPES A BIT ON MAXIMUM TEMPERATURE DUE TO THE WEAK EAST AND SOUTHEAST LOW LEVEL FLOW. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... VAST MAJORITY OF MODELS IN GOOD AGREEMENT. THIS PERIOD LOOKS QUIET WITH A STRENGTHENING UPPER RIDGE OVER THE GREAT LAKES AND OHIO VALLEY FRIDAY...QUICKLY DEVELOPING INTO A STATIONARY UPPER HIGH BY THE WEEKEND. THIS UPPER HIGH OVER OUR AREA WILL HELP FORM A WELL DEFINED OMEGA BLOCK OVER THE CONTINENTAL U.S...WITH ONE UPPER LOW OVER THE SOUTHWEST U.S. AND ANOTHER OFF THE SOUTHEAST U.S. COAST. THIS PATTERN PROTECTS US FROM SOUTHERN STREAM SYSTEMS TRYING TO EJECT OUT OF THE SOUTHWESTERN U.S. UPPER LOW. AS THE HIGH DEVELOPS AT THE SURFACE AND ALOFT...LOOK FOR A WARMING TREND WITH QUITE DRY WEATHER AND ABUNDANT SUNSHINE. FOR THE LOW LANDS...TEMPERATURES WILL WARM FROM THE 60S FRIDAY TO WELL INTO THE 70S BY MONDAY...WITH NIGHT TIME LOWS MOSTLY STAYING ABOVE FREEZING. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... COLD FRONT EXITING TO THE EAST LEAVING SOME LOW STRATUS AND DRIZZLE IN ITS WAKE. SOMEWHAT UNCERTAIN HOW LONG IFR WILL LINGER IN BKW BEFORE BREAKING UP AND LIFTING. FORECAST SOUNDINGS ARE PRETTY QUICK TO CLEAR BUT OVERALL...THINGS WILL IMPROVE FROM WEST TO EAST THIS MORNING...WITH VFR EXPECTED FOR THE REMAINDER OF THE TAF PERIOD. GENERALLY LIGHT NORTHERLY WINDS EXPECTED THROUGH THE TAF PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM THIS MORNING THEN HIGH. ALTERNATE SCENARIOS: TIMING IMPROVEMENTS MAY VARY THIS MORNING. 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. DATE TUE 04/12/16 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY M M M M M M M M M M M H HTS CONSISTENCY M M M M M M M M M M H H BKW CONSISTENCY H H M M M M M M M M M M EKN CONSISTENCY H H M M M M M M M M M M PKB CONSISTENCY M M M M M M M H H H H H CKB CONSISTENCY M M M M M M M M M M M H AFTER 12Z WEDNESDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR WVZ007>011- 016>020-027>032-039-040. OH...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR OHZ066-067- 075-076-083>087. KY...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR KYZ101>103- 105. VA...NONE. && $$ SYNOPSIS...KTB/JMV/MZ NEAR TERM...MZ/MPK SHORT TERM...KTB LONG TERM...JMV AVIATION...MZ/MPK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
644 AM EDT TUE APR 12 2016 .SYNOPSIS... COLD FRONT EXITS THIS MORNING...DRIER AIR SINKS SOUTH IN ITS WAKE. HIGH PRESSURE CENTERED TO OUR NORTH AND NORTHEAST...PROVIDES PROLONGED PERIOD OF EAST TO SOUTHEAST FLOW. && .NEAR TERM /THROUGH TONIGHT/... AS OF 600AM THE COLD FRONT HAD PUSHED THROUGH BKW AND EKN. RELIED FAIRLY HEAVILY ON THE HRRR FOR MARCHING THE COLD FRONT AND POPS ACROSS THE REMAINDER OF THE CWA EARLY THIS MORNING. THE COLD FRONT SHOULD BE EXITING TO THE EAST JUST AFTER SUNRISE...HOWEVER FORECAST SOUNDINGS SHOW LOW LEVEL MOISTURE LINGERING ACROSS THE MOUNTAINS. CODED UP SOME DRIZZLE EARLY THIS MORNING ACROSS THE EASTERN HALF OF THE CWA AS THIS MOISTURE GETS SQUEEZED OUT. HIGH PRESSURE MOVES INTO THE GREAT LAKES REGION TODAY...AND CLOUDS WILL GRADUALLY BREAK UP FROM WEST TO EAST. EXPECT A GOOD RADIATIONAL COOLING NIGHT TONIGHT WITH LITTLE TO NO CLOUD COVER. LOWS TONIGHT ARE A BIT TRICKY AS GUIDANCE IS HOVERING ON EITHER SIDE OF FREEZING FOR ALL BUT HIGHEST ELEVATIONS WHICH ARE COLDER. USED LOCALLY PRODUCED MOS BASED ON COOP SITES FOR LOWS TONIGHT. THIS PRODUCT DOES FAIRLY WELL CAPTURING THE COLD SPOTS IN SE OHIO AND NE KENTUCKY. FOR EXAMPLE THIS GUIDANCE GIVING AROUND 30 IN THE LOWER SPOTS OF GREENUP AND CARTER COUNTY KY. WITH THIS IN MIND...CONVERTED THE FREEZE WATCH TO A WARNING...AND ADDED NE KY AND LAWRENCE COUNTY OHIO TO THE MIX. FOR THE COUNTIES ALONG THE OHIO AND TUG FORK...FREEZING TEMPERATURES ARE ONLY EXPECTED AWAY FROM THE RIVERS IN OUTLYING AREAS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... THE HIGH PRESSURE CENTER NEVER SETTLES IN OUR VICINITY BUT RIDGES DOWN THE PIEDMONT FROM ITS CENTER TO OUR NORTHEAST. AS A RESULT... LOW LEVEL FLOW TURNS WEAK EAST AND SOUTHEAST WEDNESDAY NIGHT THROUGH FRIDAY. ENOUGH LOW LEVEL FLOW OVER MOUNTAINS...AND SOUTHERN PLATEAU IN THE VICINITY OF BKW...TO KEEP TEMPERATURES A FEW DEGREES MILDER AT NIGHT...AND A BIT LOWER DURING THE DAY. THE SOUTHERN SYSTEM WEAK CUT OFF OVER THE LOWER MISSISSIPPI VALLEY ON THURSDAY...MAY SPILL SOME HIGH CLOUDS NORTH. THE 00Z NAM WAS MOST AGGRESSIVE WITH SOME DEEPER MOISTURE CREEPING NORTH BY THURSDAY EVENING...INTO OUR SOUTHERN COUNTIES. WILL LEAVE POPS AOB 14 PERCENT IN OUR SOUTHERN COUNTIES. MID/UPPER RIDGE AXIS OVER US WITH WEAK WINDS AT THOSE LEVELS. AFTER THE INITIAL 850 MB WARMING ON WEDNESDAY...TEMPERATURES ALOFT SLOW TO WARM. SO NO BIG JUMP IN HIGH TEMPERATURES FOR THURSDAY AND FRIDAY. AS MENTIONED...TRIED TO HOLD DOWN THE EASTERN SLOPES A BIT ON MAXIMUM TEMPERATURE DUE TO THE WEAK EAST AND SOUTHEAST LOW LEVEL FLOW. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... VAST MAJORITY OF MODELS IN GOOD AGREEMENT. THIS PERIOD LOOKS QUIET WITH A STRENGTHENING UPPER RIDGE OVER THE GREAT LAKES AND OHIO VALLEY FRIDAY...QUICKLY DEVELOPING INTO A STATIONARY UPPER HIGH BY THE WEEKEND. THIS UPPER HIGH OVER OUR AREA WILL HELP FORM A WELL DEFINED OMEGA BLOCK OVER THE CONTINENTAL U.S...WITH ONE UPPER LOW OVER THE SOUTHWEST U.S. AND ANOTHER OFF THE SOUTHEAST U.S. COAST. THIS PATTERN PROTECTS US FROM SOUTHERN STREAM SYSTEMS TRYING TO EJECT OUT OF THE SOUTHWESTERN U.S. UPPER LOW. AS THE HIGH DEVELOPS AT THE SURFACE AND ALOFT...LOOK FOR A WARMING TREND WITH QUITE DRY WEATHER AND ABUNDANT SUNSHINE. FOR THE LOW LANDS...TEMPERATURES WILL WARM FROM THE 60S FRIDAY TO WELL INTO THE 70S BY MONDAY...WITH NIGHT TIME LOWS MOSTLY STAYING ABOVE FREEZING. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... COLD FRONT EXITING TO THE EAST LEAVING SOME LOW STRATUS AND DRIZZLE IN ITS WAKE. SOMEWHAT UNCERTAIN HOW LONG IFR WILL LINGER IN BKW BEFORE BREAKING UP AND LIFTING. FORECAST SOUNDINGS ARE PRETTY QUICK TO BUT OVERALL...THINGS WILL IMPROVE FROM WEST TO EAST THIS MORNING...WITH VFR EXPECTED FOR THE REMAINDER OF THE TAF PERIOD. GENERALLY LIGHT NORTHERLY WINDS EXPECTED THROUGH THE TAF PERIOD. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM THIS MORNING THEN HIGH. ALTERNATE SCENARIOS: TIMING IMPROVEMENTS MAY VARY THIS MORNING. 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. DATE TUE 04/12/16 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY M M M M M M M M M M M H HTS CONSISTENCY M M M M M M M M M M H H BKW CONSISTENCY H H M M M M M M M M M M EKN CONSISTENCY H H M M M M M M M M M M PKB CONSISTENCY M M M M M M M H H H H H CKB CONSISTENCY M M M M M M M M M M M H AFTER 12Z WEDNESDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR WVZ007>011- 016>020-027>032-039-040. OH...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR OHZ066-067- 075-076-083>087. KY...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR KYZ101>103- 105. VA...NONE. && $$ SYNOPSIS...KTB/JMV/MZ NEAR TERM...MZ SHORT TERM...KTB LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
350 AM EDT TUE APR 12 2016 .SYNOPSIS... COLD FRONT EXITS THIS MORNING...DRIER AIR SINKS SOUTH IN ITS WAKE. HIGH PRESSURE CENTERED TO OUR NORTH AND NORTHEAST...PROVIDES PROLONGED PERIOD OF EAST TO SOUTHEAST FLOW. && .NEAR TERM /THROUGH TONIGHT/... AS OF 350AM THE COLD FRONT IS ROUGHLY ALONG A LINE FROM BUCKHANNON TO LOGAN WV. RELIED FAIRLY HEAVILY ON THE HRRR FOR MARCHING THE COLD FRONT AND POPS ACROSS THE REMAINDER OF THE CWA EARLY THIS MORNING. THE COLD FRONT SHOULD BE EXITING TO THE EAST JUST AFTER SUNRISE...HOWEVER FORECAST SOUNDINGS SHOW LOW LEVEL MOISTURE LINGERING ACROSS THE MOUNTAINS. CODED UP SOME DRIZZLE EARLY THIS MORNING ACROSS THE EASTERN HALF OF THE CWA AS THIS MOISTURE GETS SQUEEZED OUT. HIGH PRESSURE MOVES INTO THE GREAT LAKES REGION TODAY...AND CLOUDS WILL GRADUALLY BREAK UP FROM WEST TO EAST. EXPECT A GOOD RADIATIONAL COOLING NIGHT TONIGHT WITH LITTLE TO NO CLOUD COVER. LOWS TONIGHT ARE A BIT TRICKY AS GUIDANCE IS HOVERING ON EITHER SIDE OF FREEZING FOR ALL BUT HIGHEST ELEVATIONS WHICH ARE COLDER. USED LOCALLY PRODUCED MOS BASED ON COOP SITES FOR LOWS TONIGHT. THIS PRODUCT DOES FAIRLY WELL CAPTURING THE COLD SPOTS IN SE OHIO AND NE KENTUCKY. FOR EXAMPLE THIS GUIDANCE GIVING AROUND 30 IN THE LOWER SPOTS OF GREENUP AND CARTER COUNTY KY. WITH THIS IN MIND...CONVERTED THE FREEZE WATCH TO A WARNING...AND ADDED NE KY AND LAWRENCE COUNTY OHIO TO THE MIX. FOR THE COUNTIES ALONG THE OHIO AND TUG FORK...FREEZING TEMPERATURES ARE ONLY EXPECTED AWAY FROM THE RIVERS IN OUTLYING AREAS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... THE HIGH PRESSURE CENTER NEVER SETTLES IN OUR VICINITY BUT RIDGES DOWN THE PIEDMONT FROM ITS CENTER TO OUR NORTHEAST. AS A RESULT... LOW LEVEL FLOW TURNS WEAK EAST AND SOUTHEAST WEDNESDAY NIGHT THROUGH FRIDAY. ENOUGH LOW LEVEL FLOW OVER MOUNTAINS...AND SOUTHERN PLATEAU IN THE VICINITY OF BKW...TO KEEP TEMPERATURES A FEW DEGREES MILDER AT NIGHT...AND A BIT LOWER DURING THE DAY. THE SOUTHERN SYSTEM WEAK CUT OFF OVER THE LOWER MISSISSIPPI VALLEY ON THURSDAY...MAY SPILL SOME HIGH CLOUDS NORTH. THE 00Z NAM WAS MOST AGGRESSIVE WITH SOME DEEPER MOISTURE CREEPING NORTH BY THURSDAY EVENING...INTO OUR SOUTHERN COUNTIES. WILL LEAVE POPS AOB 14 PERCENT IN OUR SOUTHERN COUNTIES. MID/UPPER RIDGE AXIS OVER US WITH WEAK WINDS AT THOSE LEVELS. AFTER THE INITIAL 850 MB WARMING ON WEDNESDAY...TEMPERATURES ALOFT SLOW TO WARM. SO NO BIG JUMP IN HIGH TEMPERATURES FOR THURSDAY AND FRIDAY. AS MENTIONED...TRIED TO HOLD DOWN THE EASTERN SLOPES A BIT ON MAXIMUM TEMPERATURE DUE TO THE WEAK EAST AND SOUTHEAST LOW LEVEL FLOW. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... VAST MAJORITY OF MODELS IN GOOD AGREEMENT. THIS PERIOD LOOKS QUIET WITH A STRENGTHENING UPPER RIDGE OVER THE GREAT LAKES AND OHIO VALLEY FRIDAY...QUICKLY DEVELOPING INTO A STATIONARY UPPER HIGH BY THE WEEKEND. THIS UPPER HIGH OVER OUR AREA WILL HELP FORM A WELL DEFINED OMEGA BLOCK OVER THE CONTINENTAL U.S...WITH ONE UPPER LOW OVER THE SOUTHWEST U.S. AND ANOTHER OFF THE SOUTHEAST U.S. COAST. THIS PATTERN PROTECTS US FROM SOUTHERN STREAM SYSTEMS TRYING TO EJECT OUT OF THE SOUTHWESTERN U.S. UPPER LOW. AS THE HIGH DEVELOPS AT THE SURFACE AND ALOFT...LOOK FOR A WARMING TREND WITH QUITE DRY WEATHER AND ABUNDANT SUNSHINE. FOR THE LOW LANDS...TEMPERATURES WILL WARM FROM THE 60S FRIDAY TO WELL INTO THE 70S BY MONDAY...WITH NIGHT TIME LOWS MOSTLY STAYING ABOVE FREEZING. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... COLD FRONT MARCHING ACROSS FORECAST AREA. PKB AND HTS GOT BRIEF IFR ALONG AND JUST BEHIND THE FRONT...SO WILL TRY TO TIME THIS OUT TO THE REST OF THE TAF SITES. OTHERWISE...WILL SEE GRADUALLY IMPROVING CONDITIONS AS CLOUDS SCATTER OUT THIS MORNING. WINDS WILL SHIFT TO NW BEHIND THE FRONT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: TIMING OF CATEGORY CHANGES MAY 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. DATE TUE 04/12/16 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY M M M M M M M M M M M H HTS CONSISTENCY M M M M M M M M M M H H BKW CONSISTENCY H H M M M M M M M M M M EKN CONSISTENCY H H M M M M M M M M M M PKB CONSISTENCY M M M M M M M H H H H H CKB CONSISTENCY M M M M M M M M M M M H AFTER 06Z WEDNESDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR WVZ007>011- 016>020-027>032-039-040. OH...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR OHZ066-067- 075-076-083>087. KY...FREEZE WARNING FROM 2 AM TO 9 AM EDT WEDNESDAY FOR KYZ101>103- 105. VA...NONE. && $$ SYNOPSIS...KTB/JMV/MZ NEAR TERM...MZ SHORT TERM...KTB LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
146 AM EDT TUE APR 12 2016 .SYNOPSIS... COLD FRONT HEADS EAST TODAY...AS DRIER AIR SINKS IN FROM THE NORTH. HIGH PRESSURE TAKES OVER WEDNESDAY AND LINGERS THROUGH MOST OF WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 0530Z COLD FRONT IS THROUGH HTS...APPROACHING CRW AND CKB. RELIED FAIRLY HEAVILY ON THE HRRR FOR MARCHING THE COLD FRONT AND POPS ACROSS THE REMAINDER OF THE CWA EARLY THIS MORNING. THE COLD FRONT SHOULD BE EXITING TO THE EAST JUST AFTER SUNRISE...HOWEVER FORECAST SOUNDINGS SHOW LOW LEVEL MOISTURE LINGERING ACROSS THE MOUNTAINS. CODED UP SOME DRIZZLE EARLY THIS MORNING ACROSS THE EASTERN HALF OF THE CWA AS THIS MOISTURE GETS SQUEEZED OUT. HIGH PRESSURE MOVES INTO THE GREAT LAKES REGION TODAY...AND CLOUDS WILL GRADUALLY BREAK UP FROM WEST TO EAST. EXPECT A GOOD RADIATIONAL COOLING NIGHT TONIGHT WITH LITTLE TO NO CLOUD COVER. LOWS TONIGHT ARE A BIT TRICKY AS GUIDANCE IS HOVERING ON EITHER SIDE OF FREEZING FOR ALL BUT HIGHEST ELEVATIONS WHICH ARE COLDER. FOR THE MOST PART...CONSENSUS KEEPS AT OR ABOVE FREEZING ACROSS THE SOUTHERN HALF OF THE CWA...WITH UPPER 20S TO LOW 30S ACROSS THE NORTH. THIS JIVES PRETTY WELL WITH GOING FORECAST...SO NO SIGNIFICANT CHANGES MADE. WILL CONTINUE FREEZE WATCH FOR NOW...AND CONTINUE TO MONITOR GUIDANCE FOR UPGRADE TO WARNING...OR CHANGES TO THE WATCH. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... HIGH PRESSURE SAILS SLOWLY BY TO THE N OF THE FCST AREA THIS PERIOD. THIS SPELLS DRY WEATHER WITH FEW CLOUD. TEMPERATURES CLOSE TO GUIDANCE IN THIS BENIGN PATTERN AND CLOSE TO PREVIOUS FCST. LEANED LOW FOR LOWS AND A BIT HIGHER FOR HIGHS FOR LARGE DIURNAL RANGES. LOWS WED NT LOOK TO BE ABOVE FREEZING BUT STILL LOW ENOUGH TO ALLOW FOR FROST. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... VAST MAJORITY OF MODELS IN GOOD AGREEMENT. THIS PERIOD LOOKS QUIET WITH A STRENGTHENING UPPER RIDGE OVER THE GREAT LAKES AND OHIO VALLEY FRIDAY...QUICKLY DEVELOPING INTO A STATIONARY UPPER HIGH BY THE WEEKEND. THIS UPPER HIGH OVER OUR AREA WILL HELP FORM A WELL DEFINED OMEGA BLOCK OVER THE CONTINENTAL U.S...WITH ONE UPPER LOW OVER THE SOUTHWEST U.S. AND ANOTHER OFF THE SOUTHEAST U.S. COAST. THIS PATTERN PROTECTS US FROM SOUTHERN STREAM SYSTEMS TRYING TO EJECT OUT OF THE SOUTHWESTERN U.S. UPPER LOW. AS THE HIGH DEVELOPS AT THE SURFACE AND ALOFT...LOOK FOR A WARMING TREND WITH QUITE DRY WEATHER AND ABUNDANT SUNSHINE. FOR THE LOW LANDS...TEMPERATURES WILL WARM FROM THE 60S FRIDAY TO WELL INTO THE 70S BY MONDAY...WITH NIGHT TIME LOWS MOSTLY STAYING ABOVE FREEZING. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... COLD FRONT MARCHING ACROSS FORECAST AREA. PKB AND HTS GOT BRIEF IFR ALONG AND JUST BEHIND THE FRONT...SO WILL TRY TO TIME THIS OUT TO THE REST OF THE TAF SITES. OTHERWISE...WILL SEE GRADUALLY IMPROVING CONDITIONS AS CLOUDS SCATTER OUT THIS MORNING. WINDS WILL SHIFT TO NW BEHIND THE FRONT. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: TIMING OF CATEGORY CHANGES MAY 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. DATE TUE 04/12/16 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY M M M M M M M M M M M H HTS CONSISTENCY M M M M M M M M M M H H BKW CONSISTENCY H H M M M M M M M M M M EKN CONSISTENCY H H M M M M M M M M M M PKB CONSISTENCY M M M M M M M H H H H H CKB CONSISTENCY M M M M M M M M M M M H AFTER 06Z WEDNESDAY... NO IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR WVZ007>011-016>020-027>032-039-040. OH...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR OHZ066-067-075-076-083>086. KY...NONE. VA...NONE. && $$ SYNOPSIS...TRM/JMV/MZ NEAR TERM...MZ SHORT TERM...TRM LONG TERM...JMV AVIATION...MZ
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1000 PM CDT WED APR 13 2016 .UPDATE... INCREASED COVERAGE OF FOG WORDING LATE TONIGHT. && .DISCUSSION... AREAS OF FOG EXPECTED TO FORM OVERNIGHT...WITH SOME DENSE FOG POSSIBLE ACROSS WESTERN THIRD OR SO OF OKLAHOMA AND ADJACENT PARTS OF NORTH TEXAS IN MOIST UPSLOPE REGION. HRRR AND SOME OF THE HIGH RES MODELS HAVE A GENERAL AGREEMENT ON THIS OCCURRENCE. WILL NOT ISSUE DENSE FOG ADVISORY AT THIS TIME...BUT OBSERVATION TRENDS WILL BE MONITORED CLOSELY. && .PREV DISCUSSION... /ISSUED 332 PM CDT WED APR 13 2016/ DISCUSSION... THE FEW REMAINING SHOWERS SHOULD DISSIPATE TOWARD SUNSET...LEADING TO PARTIAL CLEARING FOR THE EVENING AND EARLY NIGHT. TOWARD SUNRISE...CHANCES FOR FOG INCREASE. LOCALLY DENSE FOG IS A POSSIBILITY ALMOST AREA-WIDE. THURSDAY AND FRIDAY WILL BE MAINLY DRY...ALTHOUGH A FEW STRAY STORMS MAY EXTEND INTO WESTERN OKLAHOMA AND WESTERN NORTH TEXAS FROM THE TEXAS PANHANDLE ON FRIDAY...ESPECIALLY LATE IN THE DAY. AS THE CUTOFF LOW VERY SLOWLY APPROACHES FROM THE WEST...RAIN CHANCES WILL RISE INTO THE WEEKEND. WE HAVE BACKED OF SIGNIFICANTLY IN THE TIMING OF THIS SYSTEM...AS THE VARIOUS MODELS AND ENSEMBLES SEEM TO BE IN GOOD AGREEMENT THAT IT WILL BE SLOWER IN ITS EASTWARD MOVEMENT THAN PREVIOUSLY ANTICIPATED. MEDIUM-RANGE MODELS SHOW THE UPPER-LEVEL CUTOFF LOW SHIFTING SLOWLY NORTH ON SUNDAY INTO MONDAY...THEN SLOWLY EAST/SOUTHEAST WITH TIME THEREAFTER. THIS PROXIMITY WILL KEEP AT LEAST A SLIGHT CHANCE OF RAIN IN THE OKLAHOMA/NORTH TEXAS FORECAST THROUGH MIDWEEK...AT LEAST. SEVERE STORMS MAY OCCUR IN OUR FAR WESTERN COUNTIES LATE FRIDAY AND PERHAPS ON SATURDAY. HOWEVER...NOTHING MAJOR IS CURRENTLY EXPECTED WITHIN OUR FORECAST AREA. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 48 73 51 76 / 0 0 0 10 HOBART OK 49 73 52 75 / 10 0 0 10 WICHITA FALLS TX 49 74 52 78 / 10 0 0 10 GAGE OK 47 75 53 76 / 0 0 10 20 PONCA CITY OK 44 73 50 77 / 0 0 0 0 DURANT OK 51 73 53 75 / 30 10 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 11/26
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1232 PM CDT TUE APR 12 2016 .UPDATE... FOR 18Z AVIATION DISCUSSION. && .DISCUSSION... SURFACE BOUNDARY NOW PUSHING TO THE SOUTHEAST OF THE CWA. HOWEVER...850 MB BOUNDARY STILL HUNG UP ACROSS OUR AREA AND IS COMBINING WITH THE REMAINING LOW LEVEL MOISTURE TO PRODUCE SOME LIGHT SHOWER ACTIVITY ACROSS OUR AREA. LATEST RADAR TREND IS INDICATING A SLOW EASTWARD PROGRESSION WITH THE LIGHT SHOWER ACTIVITY. HRRR DATA INDICATES THESE SHOWERS SHOULD PULL EAST OF OUR AREA BY SHORTLY AFTER 12Z. OTW...LOOK FOR HIGH PRESSURE TO BUILD IN TODAY. SKIES SHOULD CLEAR AND HIGH TEMPS WILL REACH INTO THE LOWER TO MID 60S FOR MOST AREAS. BY WEDNESDAY...A WEAK SHORTWAVE WILL DEVELOP OVER THE LOWER/MID MS VALLEY. AN ASSOCIATED INVERTED TROUGH WILL DEVELOP AS WELL AND THIS FEATURE WILL BEGIN TO SPREAD SHOWER ACTIVITY BACK TO THE NORTH TOWARD TN. WILL LEAN TOWARD INCREASING POPS SOME...BEGINNING ON WED NT AND CONTINUING THROUGH FRIDAY. IN THE EXT FCST...UPPER RIDGING WILL PREVAIL FOLLOWING THE EASTWARD EXIT OF THE AFOREMENTIONED SHORTWAVE. THE WEATHER WILL REMAIN DRY BUT WE SHOULD SEE TEMPS REACHING WELL INTO THE 70S BY SUNDAY AND MONDAY. && .AVIATION... 18Z TAF DISCUSSION. EXPECT VFR THROUGH THE NEXT 24 HOURS WITH DRY HIGH PRESSURE MOVING IN FROM THE NORTH. WINDS WILL BE MAINLY NORTHEAST. SKIES WILL BE MAINLY CLEAR THROUGH TONIGHT...WITH SCT-BKN THIN CIRRUS MOVING IN AFTER 12Z. && .OHX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/AVIATION........13 LONG TERM..................31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
729 AM CDT TUE APR 12 2016 .UPDATE... FOR 12Z AVIATION DISCUSSION. && .DISCUSSION... SURFACE BOUNDARY NOW PUSHING TO THE SOUTHEAST OF THE CWA. HOWEVER...850 MB BOUNDARY STILL HUNG UP ACROSS OUR AREA AND IS COMBINING WITH THE REMAINING LOW LEVEL MOISTURE TO PRODUCE SOME LIGHT SHOWER ACTIVITY ACROSS OUR AREA. LATEST RADAR TREND IS INDICATING A SLOW EASTWARD PROGRESSION WITH THE LIGHT SHOWER ACTIVITY. HRRR DATA INDICATES THESE SHOWERS SHOULD PULL EAST OF OUR AREA BY SHORTLY AFTER 12Z. OTW...LOOK FOR HIGH PRESSURE TO BUILD IN TODAY. SKIES SHOULD CLEAR AND HIGH TEMPS WILL REACH INTO THE LOWER TO MID 60S FOR MOST AREAS. BY WEDNESDAY...A WEAK SHORTWAVE WILL DEVELOP OVER THE LOWER/MID MS VALLEY. AN ASSOCIATED INVERTED TROUGH WILL DEVELOP AS WELL AND THIS FEATURE WILL BEGIN TO SPREAD SHOWER ACTIVITY BACK TO THE NORTH TOWARD TN. WILL LEAN TOWARD INCREASING POPS SOME...BEGINNING ON WED NT AND CONTINUING THROUGH FRIDAY. IN THE EXT FCST...UPPER RIDGING WILL PREVAIL FOLLOWING THE EASTWARD EXIT OF THE AFOREMENTIONED SHORTWAVE. THE WEATHER WILL REMAIN DRY BUT WE SHOULD SEE TEMPS REACHING WELL INTO THE 70S BY SUNDAY AND MONDAY. && .AVIATION... 12Z TAF DISCUSSION. CLEARING TREND ACROSS THE AREA EXPECTED TO CONTINUE THIS MORNING. CKV ALREADY CLEAR...WITH CLEARING LINE VERY CLOSE TO BNA. LOW CLOUDS ACROSS CSV EXPECTED TO CLEAR IN A FEW HOURS. AFTER THAT POINT...VFR CONDITIONS EXPECTED THE REMAINDER OF THE PERIOD. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM/AVIATION........07 LONG TERM..................XXI
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
358 AM CDT TUE APR 12 2016 .DISCUSSION... SURFACE BOUNDARY NOW PUSHING TO THE SOUTHEAST OF THE CWA. HOWEVER...850 MB BOUNDARY STILL HUNG UP ACROSS OUR AREA AND IS COMBINING WITH THE REMAINING LOW LEVEL MOISTURE TO PRODUCE SOME LIGHT SHOWER ACTIVITY ACROSS OUR AREA. LATEST RADAR TREND IS INDICATING A SLOW EASTWARD PROGRESSION WITH THE LIGHT SHOWER ACTIVITY. HRRR DATA INDICATES THESE SHOWERS SHOULD PULL EAST OF OUR AREA BY SHORTLY AFTER 12Z. OTW...LOOK FOR HIGH PRESSURE TO BUILD IN TODAY. SKIES SHOULD CLEAR AND HIGH TEMPS WILL REACH INTO THE LOWER TO MID 60S FOR MOST AREAS. BY WEDNESDAY...A WEAK SHORTWAVE WILL DEVELOP OVER THE LOWER/MID MS VALLEY. AN ASSOCIATED INVERTED TROUGH WILL DEVELOP AS WELL AND THIS FEATURE WILL BEGIN TO SPREAD SHOWER ACTIVITY BACK TO THE NORTH TOWARD TN. WILL LEAN TOWARD INCREASING POPS SOME...BEGINNING ON WED NT AND CONTINUING THROUGH FRIDAY. IN THE EXT FCST...UPPER RIDGING WILL PREVAIL FOLLOWING THE EASTWARD EXIT OF THE AFOREMENTIONED SHORTWAVE. THE WEATHER WILL REMAIN DRY BUT WE SHOULD SEE TEMPS REACHING WELL INTO THE 70S BY SUNDAY AND MONDAY. && .AVIATION... 06Z TAF DISCUSSION. BNA/CKV/CSV...COLD FRONT HAS MOVED THROUGH NASHVILLE AND WILL SLIP ACROSS THE CUMBERLAND PLATEAU DURING THE NEXT COUPLE OF HOURS. VERY LITTLE ACTIVITY IS SHOWING UP ON RADAR AT THIS TIME, SO WILL KEEP VCSH IN FOR BNA & CSV IN THE NEAR TERM. IFR/MVFR CIGS WILL STAY AROUND FOR A FEW HOURS FOLLOWING FROPA, BUT DRIER AIR ADVECTING IN WILL IMPROVE CIGS EARLY IN THE MORNING, WITH VFR WX EXPECTED ON TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 63 40 69 52 69 / 10 0 10 20 30 CLARKSVILLE 64 38 67 49 67 / 10 0 10 20 30 CROSSVILLE 58 38 64 48 65 / 30 0 10 20 30 COLUMBIA 63 40 69 51 68 / 10 0 10 30 30 LAWRENCEBURG 64 39 70 51 68 / 20 0 10 30 30 WAVERLY 64 39 67 51 68 / 10 0 10 30 30 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM/AVIATION........07 LONG TERM..................21
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1259 AM CDT TUE APR 12 2016 .DISCUSSION...NOTE AVIATION DISCUSSION BELOW. && .AVIATION...IFR/LIFR CEILINGS AND/OR VISIBILITIES EXPECTED EARLY THIS MORNING MAINLY EAST OF STATE ROAD 16 AND MVFR WEST. A TRANSITION TO PREDOMINATE MVFR DRG THE MID/LATE MORNING. EXPECT VFR/MVFR MIXTURE DRG THE AFTN/EVENING ALONG WITH ISOLD/SCT SHOWERS AND THUNDERSTORMS. STRONG/SEVERE THUNDERSTORMS WL BE PSBL GENERALLY WEST OF U.S. 281 DRG THE 00-06Z WEDNESDAY PERIOD. && .PREV DISCUSSION... /ISSUED 850 PM CDT MON APR 11 2016/ DISCUSSION...ONLY TWO MAIN CHANGES. FIRST WAS TO INCLUDE FOG OVER INLAND AREAS TONIGHT...PATCHY WESTERN BRUSH AND RIO GRANDE PLAINS AS WELL AS COAST WITH AREAS OF FOG MOST INLAND AREAS. GFE FORECAST MONITOR MAINLY IN THE GREEN SO TEMPERATURES/DEW POINTS SEEM OK FOR NOW. SECOND CHANGE WAS TO INCREASE CLOUD COVER TONIGHT BASED ON SATELLITE AND EXPECTED STRATUS DECK DEVELOPING. OTHERWISE SEE NO NEED TO MAKE ANY CHANGES AT THIS TIME WITH RAIN CHANCES LOOKING PROMISING TUESDAY NIGHT AND WEDNESDAY. UPDATED PRODUCTS ARE OUT. MARINE FORECAST REMAINS IN LINE WITH OBSERVATIONS AND FORECAST...SO DO NOT PLAN ON CHANGES THERE. PREV DISCUSSION... /ISSUED 634 PM CDT MON APR 11 2016/ DISCUSSION...SEE 00Z AVIATION DISCUSSION. AVIATION...CONDITIONS WILL BECOME MVFR OVER THE EASTERN TERMINALS BEFORE 12/06Z...AND LIKELY IFR AT KVCT WITH MVFR BR. CONDITIONS THEN GO TO IFR/LIFR WITH VSBYS FALLING TO BLO 1SM (AT LEAST TEMPORARILY) AT KALI AND KVCT AOB 12/08Z WITH BOUNDARY APPROACHING AND 925 MB WINDS AOB 15 KNOTS. MAY HAVE TEMPO IFR BR AT KCRP BEFORE 14Z TOO. AT KLRD...GENERALLY NE/ENE WINDS BELOW 10 KNOTS WILL KEEP MOISTURE COMING IN AND THUS AM EXPECTING MVFR CIGS AFTER 12/06Z BUT BFR 12/12Z WITH MVFR BR TOO. CIGS IMPROVE TO AT LEAST MVFR AFTER 15Z (MAYBE A BIT LATER AT KVCT IF FOG IS VERY BAD). CIGS PROBABLY REMAIN MVFR AT KVCT AND KCRP...BUT VFR AOA 12/18Z AT KALI AND KLRD. DID MENTION VCSH AT EASTERN TERMINALS...WITH VCTS AND PROB30 TSRA AT KLRD MAINLY FOR THE AFTERNOON PERIODS. WINDS START OFF NORTHEAST BUT LIKELY BECOMING MORE ENE DURING THE DAY. PREV DISCUSSION... /ISSUED 344 PM CDT MON APR 11 2016/ SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...MAIN FORECAST CONCERN WILL BE THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY MORNING. OUTSIDE OF VERY LIGHT RAIN OR SPRINKLES...THE MAJORITY OF THE CONVECTION HAS REMAINED NORTHEAST OF THE AREA ACROSS EAST TEXAS. SOME HI-RES GUIDANCE DEVELOPS CONVECTION TO THE WEST AND SOUTHWEST OVER MEXICO THIS EVENING...AND SOME HRRR RUNS BRING SHOWERS/ISOLATED STORMS INTO THE RIO GRANDE PLAINS. NOT COMPLETELY CONFIDENCE ON THIS SCENARIO AND WILL LEAVE POPS OUT OF THE FORECAST BUT WILL NEED TO MONITOR TRENDS OVERNIGHT. EXPECT CLOUD COVER TO FILL BACK IN TONIGHT WITH MOSTLY CLOUDY SKIES WHICH SHOULD HOLD TEMPERATURES IN THE 60S AND LOWER 70S. A WEAK FRONTAL BOUNDARY WILL MOVE INTO SOUTH TEXAS ON TUESDAY WHICH WILL EVENTUALLY STALL ACROSS THE AREA. MOISTURE WILL BE SUFFICIENT FOR THIS TIME OF YEAR WITH PW VALUES BETWEEN 1.4 TO 1.7 INCHES. LOW CHANCES FOR SHOWERS AND STORMS WILL EXIST DURING THE DAY AND WILL KEEP POPS 30 PERCENT OUT WEST TO 20 ACROSS THE EAST. BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL THEN DEVELOP TUESDAY NIGHT INTO WEDNESDAY MORNING AS UPPER LEVEL TROUGH SWINGS INTO CENTRAL AND NORTH TEXAS. SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP IN MEXICO LATE IN THE AFTERNOON AND THEN SPREAD EASTWARD DURING THE EVENING INTO THE RIO GRANDE PLAINS AND BRUSH COUNTRY. A THREAT FOR SOME STRONG STORMS WILL BE POSSIBLE AS THE STORMS MOVE OUT OF MEXICO...BUT THE EASTWARD EXTENT OF STRONG STORMS IS OF LOWER CONFIDENCE. THERE WILL BE THE POTENTIAL FOR SOME MODERATE TO PERHAPS HEAVY RAINFALL AT TIMES GIVEN THE ABOVE NORMAL MOISTURE AND STALLED BOUNDARY NEARBY. LONG TERM (WEDNESDAY THROUGH MONDAY)...A STALLED FRONT IS PROGD TO REMAIN ACROSS S TX ON WED AND BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS. KEPT LIKELY POPS ACROSS THE EASTERN 2/3RDS OF THE CWA DUE TO UPPER SHORT WAVE...ABUNDANT MOISTURE...INSTABILITY AND CONVERGENCE ALONG THE STALLED BOUNDARY. THE GFS PROGS 2 INCH PWATS ALONG THE COAST ON WED...WHILE THE NAM IS SLIGHTLY LOWER AND HAS THE HIGHER PWATS OVER THE COASTAL WATERS. HPC KEEPS THE HIGHER QPF AMOUNTS TO THE N AND NE OF THE CWA THROUGH DAY 3 WITH 3 DAY TOTALS RANGING FROM 1-1.5 INCHES ACROSS THE N AND E CWA...BUT FEEL THAT LOCALIZED HIGHER AMOUNTS WILL BE POSSIBLE IF PWATS ARE AS HIGH AS MODELS SUGGEST. MODELS PROG A SPLIT FLOW ALOFT WHICH WOULD PROVIDE UPPER DIFFLUENCE. MODELS ALSO FCST MOD SHEAR AND CAPE VALUES WHICH MAY LEAD TO SOME STRONG STORMS...HOWEVER NOT EXPECTING SVR WX AT THIS TIME FOR WED AND SPC HAS GENERAL THUNDERSTORMS FOR S TX FOR DAY 3. AS THE UPPER SHORT WAVE TRACKS EAST...RAIN CHCS ARE EXPECTED TO DECREASE FROM W TO E WED NIGHT INTO THU. RIDGING ACROSS THE REGION WILL BRING DRIER CONDITIONS THU/FRI...THEN A POTENT UPPER LOW IS PROGD TO DVLP AND MOVE TOWARD S TX THROUGH THE WEEKEND...BRINGING ANOTHER ROUND OF SHRAS/TSRAS TO THE AREA. BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THIS POTENT LOW DVLPG...THUS CONFIDENCE IS GOOD THAT PRECIP WILL OCCUR OVER THE WEEKEND...BUT DID NOT GO AS HIGH AS SUPERBLEND OUTPUT FOR POPS AS THERE MAY BE TIMING AND POSITION ISSUES THIS FAR OUT. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 80 69 78 65 80 / 20 60 60 10 10 VICTORIA 80 65 75 60 79 / 20 60 70 10 10 LAREDO 85 69 83 64 86 / 30 60 30 10 10 ALICE 83 69 79 63 83 / 20 60 60 10 10 ROCKPORT 77 69 76 65 77 / 20 60 70 20 10 COTULLA 80 65 79 60 84 / 30 60 50 10 10 KINGSVILLE 83 69 80 64 82 / 20 60 60 10 10 NAVY CORPUS 76 70 77 67 77 / 20 60 60 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1040 PM CDT WED APR 13 2016 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 333 PM CDT WED APR 13 2016 LIGHT RAIN AND/OR SNOW ASSOCIATED WITH A MID LEVEL SHORT WAVE PAIRED WITH SOME INSTABILITY...700-500MB LAPSE RATES WERE AT LEAST 6 C/KM FOR MUCH OF THE MORNING...WAS MAINLY EAST OF THE FOX VALLEY AT 1930Z. THIS PRECIPITATION SHOULD EXIT THE FORECAST AREA LATE THIS AFTERNOON...THOUGH IT WOULD NOT BE SURPRISING IF IT LINGERED UNTIL SHORTLY AFTER SUNSET. BOTH THE 19Z HRRR AND 19Z RAP INDICATED SOME REDEVELOPMENT LATE THIS AFTERNOON/EARLY THIS EVENING. NOT CONFIDENT ENOUGH THAT THAT IS WHAT IS GOING TO HAPPEN SO HAVE NOT INCLUDED IT IN THE GRIDS. THERE WAS AT LEAST PARTIAL CLEARING ACROSS PARTS OF CENTRAL WISCONSIN THIS AFTERNOON BUT LITTLE OR NO SUNSHINE FOR THE REST OF THE AREA. THE GENERAL TREND IS FOR QUIET AND WARMER WEATHER AS A MID LEVEL RIDGE OVER THE PLAINS AMPLIFIES AS IT MOVES INTO THE GREAT LAKES REGION ON THURSDAY. TEMPERATURES WILL BE A LITTLE TRICKY IN THE SHORT TERM. WARM ADVECTION IS FORECAST TO CONTINUE ACROSS WISCONSIN OVERNIGHT...BUT IF WINDS DECREASE AND CLOUDS DEPART OR DISSIPATE TEMPERATURES...WHICH DID NOT GET ALL THAT WARM IN THE FIRST PLACE...COULD DROP LIKE A ROCK TONIGHT. BUFKIT TIME SECTIONS KEPT MOISTURE IN A LAYER BETWEEN 5-10KFT OVERNIGHT SO THERE MAY BE ENOUGH CLOUDS AROUND TO KEEP TEMPERATURES FROM GETTING TOO COLD. HAVE INCLUDED PATCHY FOG ACROSS PARTS OF NORTHERN WISCONSIN DUE TO ABUNDANT LOW LEVEL MOISTURE DEPICTED ON THE RHI TIME SECTION. EXPECT FEW CLOUDS DURING THE DAY ON THURSDAY SO TEMPERATURES SHOULD WARM UP NICELY...EXCEPT AT LOCATIONS NEAR LAKE MICHIGAN. HAVE GENERALLY GONE WITH A BLEND OF MOS FROM THE 12Z GFS AND 12Z NAM FOR HIGHS. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 333 PM CDT WED APR 13 2016 MAIN FCST CONCERNS ARE MILD TEMPERATURES...AND THE TIMING AND ASSOCIATED PCPN TRENDS WITH A COLD FRONTAL PASSAGE LATE NEXT WEEKEND. A LARGE SFC HIGH WILL BE SITUATED ACROSS EASTERN CANADA AND THE NORTHEAST UNITED STATES DURING THE BEGINNING OF THE PERIOD. IN ADDITION...A STRONG UPPER RIDGE WILL RESIDE OVER THE GREAT LAKES REGION. THIS WILL RESULT IN DRY CONDITIONS AND PLENTY OF SUNSHINE FRIDAY INTO SATURDAY. FCST H8 TEMPS SUPPORT HIGHS REACHING INTO THE MIDDLE 60S TO LOWER 70S AWAY FROM LAKE MICHIGAN FRIDAY INTO SATURDAY...ROUGHLY 10 TO 15 DEGREES ABOVE NORMAL. THE BIGGEST CHALLENGE REVOLVES AROUND THE TIMING OF A CANADIAN COLD FRONT LATE IN THE WEEKEND. LATEST MEDIUM RANGE MODELS AND THEIR ENSEMBLE MEANS SUPPORT A FASTER FRONTAL PASSAGE...WITH ASSOCIATED RAIN CHANCES CONFINED TO SUNDAY AND SUNDAY NIGHT...AND DRY CONDITIONS RETURNING BY MONDAY. WILL NEED TO SPEED UP THE PCPN TIMING A BIT. DRY CONDITIONS SHOULD PREVAIL FOR THE FIRST HALF OF THE NEXT WORK WEEK...WITH CANADIAN HIGH PRESSURE OVER THE REGION. TEMPERATURE FCSTS WILL NOT BE EASY DUE TO LARGE DIFFERENCES IN H8 TEMPS BETWEEN THE WARMER ECMWF AND COOLER GFS ON MONDAY AND TUESDAY. ENSEMBLE MEANS SUGGEST H8 TEMPS SOMEWHERE IN BETWEEN...WHICH SHOULD STILL SUPPORT ABOVE NORMAL TEMPERATURES. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1040 PM CDT WED APR 13 2016 LOCAL IFR CEILINGS AND VISIBILITIES POSSIBLE OVER NORTHCENTRAL WISCONSIN ALONG THE SHORE OF THE BAY OVERNIGHT. JUST SOME BROKEN MIDDLE CLOUDS ELSEWHERE TONIGHT. GOOD FLYING WEATHER EXPECTED THURSDAY THROUGH SATURDAY WITH MAINLY CLEAR SKIES. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MG LONG TERM......KIECKBUSCH AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
851 PM CDT WED APR 13 2016 .UPDATE... PESKY PERSISTENT 700MB WARM AIR ADVECTION OVER EASTERN WI KEEPING THE MID LEVEL CLOUDS IN PLACE FOR THE TIME BEING. ALL THE MODELS SHOW THIS BREAKING DOWN OVERNIGHT AND THIS SHOULD SPELL THE END OF THE CLOUDS. OTHER THAN THAT...FORECAST ON TRACK. && .AVIATION/06Z TAFS/... VFR CONDITIONS EXPECTED DURING THE TAF PERIOD. WINDS STEADY OUT OF THE SOUTHEAST TO EAST AS WELL...PEAKING AROUND 10 TO 12 KNOTS THURSDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 328 PM CDT WED APR 13 2016/ SHORT TERM... TONIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH A MID-LEVEL SHORTWAVE TROUGH WITH ASSOCIATED POSITIVE VORTICITY ADVECTION HAS MOVED OFF TO THE EAST AND SOUTHEAST...AND SLOWLY WILL BE REPLACED WITH MID-LEVEL RIDGING AND SUBSIDENCE DUE TO NEGATIVE VORTICITY ADVECTION. BUFKIT MODEL SOUNDINGS OF THE RAP AND NAM ARE INDICATING MOSTLY DRY PROFILES ACROSS S WI TONIGHT...SAVE FOR SOME LINGERING MOISTURE IN THE 700 TO 750 MB LAYER. SO...SOME CLOUDS MAY LINGER TONIGHT...BUT SLOWLY DISSIPATE THROUGH THURSDAY MORNING. DRY AIR WILL CONTINUE TO MOVE INTO THE REGION THURSDAY...WHICH SHOULD SUPPORT MOSTLY SUNNY SKIES ACROSS S WI THURSDAY AFTERNOON. THE AXIS OF THE MID-LEVEL RIDGE WILL SLOWLY MAKE ITS WAY INTO THE REGION DURING THE DAY THURSDAY ALONG WITH THE DRY AIR. SOUTHEAST WINDS WITH GUSTS BETWEEN 10 TO 20 KTS ARE POSSIBLE ACROSS THE FORECAST AREA AS SFC PRESSURE GRADIENT TIGHTENS. TEMPERATURES CONTINUE TO GRADUALLY INCREASE AS HIGHS ON THURSDAY ARE EXPECTED TO BE IN THE 60 TO 65 F RANGE THANKS TO ENHANCED LOW-LEVEL WARM AIR ADVECTION AND ABUNDANT SUNSHINE. 13.12Z GFS AND NAM 925 MB TEMPS INCREASE TO THE 6 TO 10 DEGREE C RANGE FROM NORTHEAST TO SOUTHWEST RESPECTIVELY ACROSS OUR FORECAST AREA BY 21Z THURSDAY. EAST TO SOUTHEASTERLY WINDS WILL KEEP TEMPERATURES COOLER ALONG LAKE MICHIGAN...WITH HIGHS ALONG THE LAKE FRONT IN THE UPPER 40S TO MID 50S FURTHER INLAND. THURSDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE HIGH. A LARGE OMEGA BLOCK WILL FORM OVER THE CONUS AND WRN ATLANTIC OCEAN DURING THIS PERIOD. THE HIGH AMPLITUDE UPPER RIDGE WILL CENTER OVER THE GREAT LAKES WITH A SELY SFC FLOW EACH DAY. MO SUNNY DAYS AND MO CLEAR NIGHTS WITH A GRADUAL WARMING TREND IS EXPECTED THROUGH THE WEEKEND. HIGH TEMPS WILL WARM INTO THE LOWER 70S WELL INLAND FROM LAKE MI FOR THE WEEKEND. TEMPS WILL REMAIN ABOVE THE FREEZING MARK AT NIGHT WITH LOWS RANGING FROM THE MID-UPPER 30S TO MID-UPPER 40S. LONG TERM...MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM. A SHORTWAVE TROUGH IN FAST WNWLY FLOW ALOFT WILL BREAK DOWN THE UPPER RIDGE BY LATE SUN AS IT MOVES ACROSS THE NRN GREAT LAKES. A TRAILING COLD FRONT WILL PASS ACROSS SRN WI SUN NT INTO MON WITH ONLY SLIGHT CHANCES OF SHOWERS. THE SHORTWAVE TROUGH ALONG WITH ANOTHER UPPER TROUGH OVER ERN CANADA WILL THEN DIG A LARGE SCALE UPPER TROUGH OVER ERN CANADA INTO NEW ENGLAND AND THE MID ATLANTIC STATES. MEANWHILE THE UPPER LOW THAT WAS IN THE FOUR CORNERS REGION WILL BE KEPT FARTHER SOUTH DUE TO THE STRONGER NLY WINDS ALOFT OVER THE GREAT LAKES. THUS SFC HIGH PRESSURE WILL BE IN THE VICINITY OF WI FOR TUE AND WED. MILD TEMPS WILL CONTINUE FOR NEXT WEEK. AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED AS A MID-LEVEL RIDGE WITH DRY AIR MAKES ITS WAY INTO THE REGION. BKN TO SCT MID TO HIGH LEVEL CLOUDS ARE EXPECTED TONIGHT...BUT SKIES LOOK TO SLOWLY CLEAR OUT OVERNIGHT INTO THE DAY THURSDAY...WITH SUNNY SKIES EXPECTED. WINDS WILL REMAIN FROM THE SOUTHEASTERLY DIRECTION...WITH GUSTS BETWEEN 15 TO 20 KTS POSSIBLE THURSDAY. MARINE... SOUTHEAST WINDS LOOK TO EASE A LITTLE TONIGHT...BEFORE INTENSIFYING DURING THE DAY THURSDAY. WAVES ARE FORECAST TO BE BETWEEN 1 TO 3 FEET OVER THE NEARSHORE WATERS...AND LOOK TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. POTENTIAL ALSO EXISTS FOR SOME LIGHT MARINE FOG TONIGHT DUE TO THE COOLER LAKE TEMPERATURES AND GRADUALLY INCREASING WARM AIRMASS OVERHEAD. CONFIDENCE IS NOT HIGH ON THIS AT THIS TIME...BUT SOME MODEL GUIDANCE IS SHOWING SIGNS OF THIS LIGHT MARINE AREA FOG TONIGHT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DAVIS TONIGHT/THURSDAY AND AVIATION/MARINE...JTS THURSDAY NIGHT THROUGH WEDNESDAY...GEHRING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
730 PM CDT WED APR 13 2016 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 333 PM CDT WED APR 13 2016 LIGHT RAIN AND/OR SNOW ASSOCIATED WITH A MID LEVEL SHORT WAVE PAIRED WITH SOME INSTABILITY...700-500MB LAPSE RATES WERE AT LEAST 6 C/KM FOR MUCH OF THE MORNING...WAS MAINLY EAST OF THE FOX VALLEY AT 1930Z. THIS PRECIPITATION SHOULD EXIT THE FORECAST AREA LATE THIS AFTERNOON...THOUGH IT WOULD NOT BE SURPRISING IF IT LINGERED UNTIL SHORTLY AFTER SUNSET. BOTH THE 19Z HRRR AND 19Z RAP INDICATED SOME REDEVELOPMENT LATE THIS AFTERNOON/EARLY THIS EVENING. NOT CONFIDENT ENOUGH THAT THAT IS WHAT IS GOING TO HAPPEN SO HAVE NOT INCLUDED IT IN THE GRIDS. THERE WAS AT LEAST PARTIAL CLEARING ACROSS PARTS OF CENTRAL WISCONSIN THIS AFTERNOON BUT LITTLE OR NO SUNSHINE FOR THE REST OF THE AREA. THE GENERAL TREND IS FOR QUIET AND WARMER WEATHER AS A MID LEVEL RIDGE OVER THE PLAINS AMPLIFIES AS IT MOVES INTO THE GREAT LAKES REGION ON THURSDAY. TEMPERATURES WILL BE A LITTLE TRICKY IN THE SHORT TERM. WARM ADVECTION IS FORECAST TO CONTINUE ACROSS WISCONSIN OVERNIGHT...BUT IF WINDS DECREASE AND CLOUDS DEPART OR DISSIPATE TEMPERATURES...WHICH DID NOT GET ALL THAT WARM IN THE FIRST PLACE...COULD DROP LIKE A ROCK TONIGHT. BUFKIT TIME SECTIONS KEPT MOISTURE IN A LAYER BETWEEN 5-10KFT OVERNIGHT SO THERE MAY BE ENOUGH CLOUDS AROUND TO KEEP TEMPERATURES FROM GETTING TOO COLD. HAVE INCLUDED PATCHY FOG ACROSS PARTS OF NORTHERN WISCONSIN DUE TO ABUNDANT LOW LEVEL MOISTURE DEPICTED ON THE RHI TIME SECTION. EXPECT FEW CLOUDS DURING THE DAY ON THURSDAY SO TEMPERATURES SHOULD WARM UP NICELY...EXCEPT AT LOCATIONS NEAR LAKE MICHIGAN. HAVE GENERALLY GONE WITH A BLEND OF MOS FROM THE 12Z GFS AND 12Z NAM FOR HIGHS. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 333 PM CDT WED APR 13 2016 MAIN FCST CONCERNS ARE MILD TEMPERATURES...AND THE TIMING AND ASSOCIATED PCPN TRENDS WITH A COLD FRONTAL PASSAGE LATE NEXT WEEKEND. A LARGE SFC HIGH WILL BE SITUATED ACROSS EASTERN CANADA AND THE NORTHEAST UNITED STATES DURING THE BEGINNING OF THE PERIOD. IN ADDITION...A STRONG UPPER RIDGE WILL RESIDE OVER THE GREAT LAKES REGION. THIS WILL RESULT IN DRY CONDITIONS AND PLENTY OF SUNSHINE FRIDAY INTO SATURDAY. FCST H8 TEMPS SUPPORT HIGHS REACHING INTO THE MIDDLE 60S TO LOWER 70S AWAY FROM LAKE MICHIGAN FRIDAY INTO SATURDAY...ROUGHLY 10 TO 15 DEGREES ABOVE NORMAL. THE BIGGEST CHALLENGE REVOLVES AROUND THE TIMING OF A CANADIAN COLD FRONT LATE IN THE WEEKEND. LATEST MEDIUM RANGE MODELS AND THEIR ENSEMBLE MEANS SUPPORT A FASTER FRONTAL PASSAGE...WITH ASSOCIATED RAIN CHANCES CONFINED TO SUNDAY AND SUNDAY NIGHT...AND DRY CONDITIONS RETURNING BY MONDAY. WILL NEED TO SPEED UP THE PCPN TIMING A BIT. DRY CONDITIONS SHOULD PREVAIL FOR THE FIRST HALF OF THE NEXT WORK WEEK...WITH CANADIAN HIGH PRESSURE OVER THE REGION. TEMPERATURE FCSTS WILL NOT BE EASY DUE TO LARGE DIFFERENCES IN H8 TEMPS BETWEEN THE WARMER ECMWF AND COOLER GFS ON MONDAY AND TUESDAY. ENSEMBLE MEANS SUGGEST H8 TEMPS SOMEWHERE IN BETWEEN...WHICH SHOULD STILL SUPPORT ABOVE NORMAL TEMPERATURES. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 729 PM CDT WED APR 13 2016 VFR WEATHER EXPECTED FOR THE NEXT FEW DAYS WITH JUST SOME MID CLOUDS AT TIME TONIGHT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MG LONG TERM......KIECKBUSCH AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1043 PM PDT WED APR 13 2016 .SYNOPSIS....A FAST MOVING COLD FRONT WILL SPREAD RAIN ACROSS MOST OF THE SAN FRANCISCO BAY REGION LATE WEDNESDAY NIGHT. DRY WEATHER CONDITIONS WILL RETURN TO MOST AREAS BY MID MORNING ON THURSDAY. DRY WEATHER WILL THEN PERSIST FROM FRIDAY THROUGH THE UPCOMING WEEKEND...ALONG WITH A WARMING TREND. TEMPERATURES ARE EXPECTED TO BE WELL ABOVE NORMAL OVER THE WEEKEND. COOLING IS THEN EXPECTED MONDAY AND TUESDAY OF NEXT WEEK AS AN UPPER TROUGH APPROACHES THE WEST COAST. && .DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...AFTER SEVERAL CONSECUTIVE DAYS OF CLOUDY TO MOSTLY CLOUDY WEATHER...OUR REGION BASKED UNDER MOSTLY SUNNY SKIES TODAY. HIGHS WERE MOSTLY IN THE 60S. EVENING SATELLITE AND RADAR DATA SHOW A COLD FRONT PUSHING INLAND ACROSS FAR NORTHWEST CALIFORNIA. THIS FRONT HAS HAD A HISTORY OF PRODUCING THUNDERSTORMS ALONG THE OREGON COAST AND NORTHERN CALIFORNIA COAST NORTH OF CAPE MENDOCINO. HOWEVER...THE FRONT IS FORECAST TO WEAKEN CONSIDERABLY AS IT PUSHES SOUTH INTO OUR AREA OVERNIGHT WHICH WILL REDUCE THUNDERSTORM CHANCES TO NEARLY ZERO. BUT THE FRONT WILL MAINTAIN SUFFICIENT MOISTURE AND DYNAMICS TO PRODUCE RAINFALL ACROSS MUCH OF OUR FORECAST AREA OVERNIGHT. THE LATEST NAM AND HRRR MODELS ARE IN GOOD AGREEMENT ON PRECIPITATION TIMING OVERNIGHT. BOTH SPREAD RAIN INTO NORTHERN SONOMA COUNTY JUST PRIOR TO MIDNIGHT AND ACROSS THE ENTIRE NORTH BAY BY 2 AM. RAIN IS THEN EXPECTED TO SPREAD ACROSS THE REMAINDER OF THE SF BAY AREA AND SANTA CRUZ COUNTY BY 4 AM THURSDAY. THE FRONT IS FORECAST TO DISSIPATE BY THE TIME IT REACHES NORTHERN MONTEREY COUNTY AROUND SUNRISE THURSDAY MORNING. LITTLE OR NO RAIN IS EXPECTED SOUTH OF MONTEREY BAY. BECAUSE THIS FRONT WILL BE MOVING THROUGH QUICKLY...RAINFALL AMOUNTS ARE FORECAST TO BE LIGHT. MOST MODEL OUTPUT FORECASTS QPF OF A QUARTER INCH OR LESS BY SUNRISE THURSDAY MORNING...ALTHOUGH THE LATEST HRRR FORECASTS ISOLATED AMOUNTS OF UP TO A HALF INCH IN THE NORTH BAY. VERY LITTLE IN THE WAY OF POST-FRONTAL PRECIPITATION IS EXPECTED WITH THIS SYSTEM. THE NAM AND GFS FORECAST SOME LIGHT SHOWER ACTIVITY ACROSS NORTHERN SONOMA COUNTY ON THURSDAY. OTHERWISE ALL MODEL DATA INDICATE A DRY DAY FOR THE MOST PART. THE AIRMASS BEHIND THE FRONT WILL BE QUITE COOL...WITH 850 MB TEMPS FORECAST TO DROP AS LOW AS ZERO DEGREES C IN THE NORTH BAY ON THURSDAY MORNING. BUT THERE SHOULD BE PLENTY OF SUN BY MIDDAY TO OFFSET THIS COOL AIRMASS TO SOME EXTENT AND AFTERNOON HIGHS ARE EXPECTED TO BE ONLY SLIGHTLY COOLER THAN AVERAGE. BRISK NORTHWEST WINDS WILL DEVELOP NEAR THE COAST BY THURSDAY AFTERNOON WITH LOCAL GUSTS UP TO 30 MPH POSSIBLE. AN UPPER RIDGE IS FORECAST TO QUICKLY DEVELOP JUST OFFSHORE BY FRIDAY...WHICH WILL NOT ONLY BEGIN TO WARM THE AIRMASS OVER OUR AREA...BUT ALSO TURN THE FLOW MORE NORTHERLY AND BRING A DRIER AIRMASS INTO OUR REGION. EXPECT HIGH TEMPERATURES ON FRIDAY TO BE AS MUCH AS 15 DEGREES WARMER IN THE NORTH BAY VALLEYS WHERE DOWNSLOPE WARMING IS EXPECTED. ELSEWHERE WARMING ON FRIDAY WILL BE MORE MODEST. THE WARMING TREND WILL THEN CONTINUE THROUGH THE UPCOMING WEEKEND AS THE UPPER RIDGE BUILDS INLAND OVER CA AND LIGHT OFFSHORE FLOW DEVELOPS. WIDESPREAD HIGH TEMPERATURES IN THE UPPER 70S AND LOWER 80S ARE FORECAST BY SUNDAY...AT BOTH INLAND AND COASTAL LOCATIONS. THE UPPER RIDGE AXIS IS FORECAST TO MOVE OFF TO OUR EAST BY MONDAY WHILE AN UPPER TROUGH APPROACHES THE WEST COAST...AND ONSHORE FLOW WILL RETURN. THESE DEVELOPMENTS WILL RESULT IN SIGNIFICANT COOLING ON MONDAY AND TUESDAY. THE MEDIUM RANGE MODELS AGREE THAT THE TROUGH WILL LIFT QUICKLY TO THE NORTHEAST AS IT APPROACHES THE COAST AND SO PRECIPITATION POTENTIAL APPEARS MINIMAL LATE MONDAY NIGHT AND TUESDAY. && .AVIATION...AS OF 10:52 PM PDT WEDNESDAY...THE CURRENT IR SATELLITE IMAGE IS SHOWING MOSTLY HIGH CLOUDS OVER THE TERMINALS THIS EVENING...HOWEVER A COLD FRONT MOVING THROUGH NORTHERN CALIFORNIA AND IS QUICKLY APPROACHING THE NORTH BAY AREA AT THIS HOUR. THE COLD FRONT WILL SLIDE SOUTH OVERNIGHT RESULTING IN LIGHT RAIN AT ALL TERMINALS LATE TONIGHT. THE FRONT WILL BE OUT OF THE AREA BY SUNRISE FRIDAY MORNING. VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST MIDNIGHT. LIGHT RAIN IS ANTICIPATED BETWEEN 1000Z AND 1200Z WITH SHOWERS POSSIBLE FROM 1200Z TO 1500Z. WINDS ARE ANTICIPATED TO BE GENERALLY SOUTHWEST OVERNIGHT BECOMING WESTERLY THURSDAY AFTERNOON. CONFIDENCE IS MODERATE. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST MIDNIGHT. LIGHT RAIN IS ANTICIPATED BETWEEN 1100Z AND 1500Z. WINDS ARE ANTICIPATED TO INCREASE OUT OF THE SOUTHERLY DIRECTION OVERNIGHT AS THE FRONT NEARS THE MONTEREY COAST. WINDS ARE EXPECTED TO BECOME WESTERLY THURSDAY AFTERNOON. CONFIDENCE IS MODERATE. && .MARINE...AS OF 10:34 PM PDT WEDNESDAY...GUSTY SOUTHWESTERLY WINDS ARE EXPECTED OVERNIGHT AS A COLD FRONT APPROACHES THE COASTAL WATERS. ON THURSDAY MORNING WINDS WILL BECOME NORTHWESTERLY BEHIND THE DEPARTING FRONT. WINDS WILL INCREASE IN THE AFTERNOON AS COOL AIR PUSHES IN TO THE AREA BEHIND THE FRONT. NORTHWESTERLY SWELLS WILL CONTINUE TO BUILD OVERNIGHT PEAKING ON THURSDAY BEFORE SUBSIDING BY THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY SOUTH TO MONTEREY COUNTY SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...ROUGH BAR ADVISORY FOR SF BAR FROM 9 PM && $$ PUBLIC FORECAST: DYKEMA AVIATION: LARRY MARINE: LARRY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
420 AM EDT THU APR 14 2016 .DISCUSSION... ...HIGHER RAIN CHANCES WILL CONTINUE THROUGH THE END OF THE WEEK... ...HAZARDOUS BOATING/BEACH CONDITIONS WILL DEVELOP THIS WEEKEND... CURRENT...NEXRAD 88D SHOWS SCATTERED SHOWERS AND ISOLATED STORMS OVER THE GULF STREAM EARLY THIS MORNING. A WEAK BOUNDARY PUSHING SOUTH WITH OUTFLOW FROM THE PREVIOUS EVENING`S CONVECTION WILL LIE ACROSS AROUND LAKE OKEECHOBEE BY SUNRISE AND BECOME DIFFUSE SOON THEREAFTER. CONTINUED MILD AND MUGGY WITH BOTH TEMPERATURES/DEWPOINT READINGS WELL INTO THE 60S AREAWIDE. WINDS LIGHT/VARIABLE WITH MCLOUDY SKIES. WILL NEED TO MONITOR LOW STRATUS CLOUD/PATCHY GROUND FOG DEVELOPMENT EARLY THIS MORNING...ESPECIALLY ALONG/NORTH OF I-4 WITH ADDITIONAL MOISTURE NEAR THE SURFACE AS MOS GUIDANCE IS PICKING UP ON THIS. TODAY-TONIGHT...THROUGH THE MORNING WINDS WILL TRANSITION BACK TO S/SE ACROSS THE AREA. THIS ACCORDING TO LOCAL MODELS (HRRR/WRF). THE PRESSURE GRADIENT REMAINS FAIRLY LIGHT AND SUSPECT THERE WILL BE A DEGREE OF VARIABILITY TO DIRECTIONAL COMPONENT ON THIS DAY SO CONFIDENCE LOW HERE. WIND SPEEDS GENERALLY UNDER 10 MPH FOR MOST OF THE DAY. THE EAST COAST SEA BREEZE WILL DEVELOP BY EARLY AFTERNOON AND PUSH INLAND ONCE AGAIN AS WELL WILL THE WEST COAST SEA BREEZE ON THE OTHER SIDE OF THE PENINSULA. UNSETTLED CONDITIONS CONTINUE ALOFT AS PERIODIC VORTICITY IMPULSES TRAVERSE THE REGION. WILL NOT RULE OUT AN ISOLATED SHOWER DURING THE MORNING BUT SIMILAR TO YESTERDAY...AS THE AFTERNOON GROWS OLD...OUR SHOWER AND STORM CHANCES WILL INCREASE. SURFACE HEATING IS IN QUESTION A BIT BUT ANTICIPATE WE WILL SEE SOME PERIODS OF CLOUDS AS WELL AS SOME BREAKS. COOLER TEMPERATURES ALOFT AGAIN (-12C/-13C) AT 500MB PROMOTING INSTABILITY. EXPECT BOUNDARY COLLISIONS LATER IN THE DAY/EARLY EVENING ALLOWING FOR AN INCREASE IN COVERAGE TO LIKELY (60-70 PERCENT) FROM KMCO-KTTS NORTHWARD. CHANCE POPS SOUTH OF HERE (40-50 PERCENT). MOVEMENT OF ACTIVITY GENERALLY BACK TOWARDS THE EAST COAST AGAIN AT 10 TO 15 MPH. A FEW STRONG STORMS WILL BE POSSIBLE WITH CLOUD TO GROUND LIGHTNING...TORRENTIAL DOWNPOURS...GUSTY WINDS UP TO AROUND 45 MPH AND SMALL HAIL THE MAIN THREATS. AFTERNOON HIGHS IN THE L80S AREAWIDE. OVERNIGHT LOWS CONTINUED MILD AND GENERALLY IN THE M-U60S. FRI-SUN...GLOBAL MODEL GUIDANCE REMAINS CONSISTENT IN QUICKLY WEAKENING THE CTRL-ERN CONUS "REX" BLOCK FRIDAY WITH THE SYNOPTIC PATTERN OVER THE CONUS TRANSITIONS TO A WELL DEVELOPED OMEGA BLOCK BY THIS WEEKEND. RAPIDLY WEAKENING H50 LOW DRIFTS EWD ACROSS THE SE CONUS BENEATH THE "REX HIGH" FRI...BEFORE SHEARING OUT RAPIDLY FRI NIGHT/SAT. RESIDUAL RIBBON OF H50 VORT LINGERS ACROSS THE STATE THROUGH THE WEEKEND WITH THE PREFERRED GFS CONTINUING TO SHOW MORE SLOWER SHEARING AND THUS MORE RESIDUAL MID LEVEL TROUGHING HANGING BACK ACROSS FL ON SAT. AXIS OF THE RIDGE ANCHORING THE OMEGA WILL RETROGRADE SLIGHTLY THROUGH THE WEEKEND...AS THE S TO SSW MOVING WRN ATLC LOW DOES THE SAME. AT THE SFC...WEAK INVERTED TROUGH OVER THE STATE FRI GETS FLATTENED AT BY NE SURGE BTWN WITH THE STRONG SFC HIGH TO THE NORTH AND THE DEEPENING LOW TO ITS EAST OVER THE WRN ATLC. PATTERN STILL SHAPING UP TO BE WET FRI-SAT (LIKELY POPS BOTH DAYS) AND STRONG STORMS ARE A DECENT BET FRIDAY AS TEMPS COOL ALOFT (13C/- 14C @H50) IN PRESENCE OF DEEP MOISTURE AND ENHANCED LOW LEVEL CONVG. SAT LOOKS SHOWERY WITH DEEP MOISTURE STILL DRAPED OVER THE REGION... BUT LOWER CHC FOR STORMS GIVEN STRENGTHENING ONSHORE WINDS SHOULD RESULT IN DECREASED SFC BASED CONVG/INSTABILITY. HOWEVER... TEMPS H50 TEMPS ARE ACTUALLY ABOUT A DEGREE COLDER...SO CAN`T RULE OUT AN ISOLD TS. DEEP MOISTURE FINALLY GETS SHUNTED SOUTH SAT NIGHT/ SUN WITH JUST A SMALL CHC FOR A COASTAL SHOWER IN CONTINUED BREEZY ONSHORE (ENE TO NE) WIND FLOW. TEMPS A LITTLE ABOVE NORMAL FRI-FRI NIGHT WILL DROP BACK CLOSER TO NORMAL THIS WEEKEND WITH WINDS PROBABLY HOLDING MINS ABOVE GUIDANCE ALONG THE IMMEDIATE COAST. MON-WED...FORECAST REMAINS DRY FROM EARLY-MID NEXT WEEK AS HIGH PRES SETTLES SWD OVER FL. SOME INDICATIONS BY THE GFS OF A WEAK BACK DOOR FRONT TAKING A RUN AT NORTH FL LATE WED...BUT WITH THE ECM KEEPING THIS FEATURE WELL TO THE N/E...NOT BITING OFF ON THAT SOLN. TEMPS START OFF A DEG OR SO JUST OFF CLIMO BEFORE WARMING TO NORMAL TUE-WED. && .AVIATION...WILL MONITOR AGAIN EARLY THIS MORNING FOR SOME LOWER CIGS NEAR/NORTH OF I-4 AS SUGGESTED BY MOS GUIDANCE. SOME PATCHY GROUND FOG CANNOT BE RULED OUT DUE TO MOISTURE NEAR THE SURFACE FROM THE PREVIOUS EVENING`S RAINS WHICH WE HAVEN`T SEEN IN A WHILE. LOW CONFIDENCE IN WIND DIRECTIONAL COMPONENT...THOUGH HRRR SHOWS CURRENT LIGHT NORTHERLY COMPONENT BECOMING S/SE LATER IN THE MORNING. ANTICIPATE VARIABILITY IN WIND DIRECTION TODAY WITH SPEEDS GENERALLY LESS THAN 10 KTS. THE ECSB WILL DEVELOP AGAIN TODAY AND PUSH INLAND WITH COLLISION LATE DAY/EARLY EVENING WITH ITS WEST COAST COUNTERPART. THE MAJORITY OF THE RESULTANT COLLISION CONVECTION SHOULD FAVOR THE EASTERN PENINSULA WITH WESTERLY STEERING FLOW ALOFT. CURRENTLY HAVE VCTS IN THE TAFS FOR LATER IN THE AFTERNOON. TEMPO GROUPS LIKELY WITH FURTHER CONFIDENCE IN TIMING. SCT-NMRS SHRA COVERAGE AND ISOLD-SCT TSRA COVERAGE FOR LATE DAY/EVENING. PERIODIC IMPULSES TRAVELING ACROSS THE AREA LATER TODAY MAY AID IN A FEW STRONG STORMS. && .MARINE...TODAY-TONIGHT...GENERALLY LIGHT/VARIABLE WINDS ACROSS THE COASTAL WATERS THIS MORNING WITH WEAK PRESSURE GRADIENT IN PLACE AND DISTORTED WIND FIELD FROM THE PREVIOUS NIGHT`S CONVECTION. VARIOUS MODELS NOT HANDLING TODAY`S WIND FIELDS VERY WELL SO LOW CONFIDENCE IN DIRECTIONAL COMPONENT...THOUGH SPEEDS GENERALLY LESS THAN 10 KTS. THE ECSB WILL DEVELOP EARLY THIS AFTERNOON AND PUSH SLOWLY INLAND SO AN ONSHORE FLOW EXPECTED ALONG THE SPACE/TREASURE COAST AT LEAST BY LATER IN THE MORNING OR EARLY AFTERNOON. WITH A RESIDUAL SURFACE BOUNDARY SLIDING SOUTH INTO THE AREA LATER TODAY MAY SEE MORE S/SERLY WINDS THRU MUCH OF THE DAY...EXCEPT E/NERLY WINDS VOLUSIA COAST IF BOUNDARY TO THE NORTH SLIDES A BIT QUICKER SOUTHWARD. SEAS BUILDING 3-4 FT NEAR SHORE TODAY AND MAINLY 4-5 FT NORTH OF SEBASTIAN INLET OFFSHORE. SEAS MAY CONTINUE TO BUILD TOWARD 6 FEET LATE TONIGHT WELL OFFSHORE OF THE VOLUSIA COAST. AN EAST-NORTHEAST LONG PERIOD SWELL WILL BE SLOWLY INCREASING THROUGH LATE IN THIS PERIOD. WITH DEEPER MOISTURE IN PLACE...VARIOUS DISTURBANCES ALOFT MOVING ACROSS THE AREA AND DEVELOPING TROUGHING ALONG THE EAST FL COAST EXPECT AN INCREASED THREAT FOR SHOWERS AND ISOLD STORMS...ESPECIALLY NORTH OF THE CAPE. A FEW STORMS MAY AGAIN MOVE OFF OF THE EAST COAST LATE IN THE DAY AND THIS EVENING. A FEW COULD BE STRONG. WINDS/SEAS LOCALLY HIGHER INVOF SHOWERS/STORMS. FRI-MON...PRESENCE OF TROUGH OVER THE AREA FRIDAY WILL KEEP WINDS AND SEAS BLO 15KT FOR MOST OF THE MAOR THROUGH FRI NIGHT HOWEVER HIGHER WINDS/SEAS MAY LEAK INTO THE VOLUSIA WATERS (15-20KT/6-9FT) LATE IN THE DAY AS TROUGH AXIS SLIPS SWD A BIT. BOATING AND BEACH CONDITIONS WILL DETERIORATE RAPIDLY N-S ON SAT AS STRONG NE TO ENE WIND SURGE COUPLED WITH LENGTHENING NE FETCH BTWN STRONG ERN CONUS HIGH/DEEP WRN ATLC LOW CAUSES BOTH AN INCREASING WIND CHOP AND BUILDING NE SWELL. 6-9FT SEAS WILL OVERSPREAD MUCH OF THE MAOR SAT...WITH 6-9FT SEAS EXPECTED NEAR SHORE AND 10-11FT SEAS WELL OFFSHORE THROUGH MONDAY. BOATERS AND BEACHGOERS ARE REMINDED THAT THIS REMAINS A VERY HIGH CONFIDENCE MARINE EVENT GIVEN THE MODEL AGREEMENT AND PERSISTENCE. SCA WILL LIKELY BE NEEDED THIS WEEKEND...POSSIBLY AS EARLY AS LATE FRI FOR THE VOLUSIA COUNTY WATERS. A HIGH SURF ADVISORY MAY NEED TO BE CONSIDERED AS WELL FOR LATE SAT THROUGH MON. && .PRELIMINARY POINT TEMPS/POPS... DAB 80 64 78 66 / 70 50 60 40 MCO 84 65 83 66 / 60 50 70 40 MLB 83 65 79 68 / 50 30 70 40 VRB 83 65 81 67 / 40 40 70 40 LEE 81 64 80 64 / 70 40 60 40 SFB 82 65 81 65 / 70 50 60 40 ORL 83 66 81 66 / 60 50 70 40 FPR 84 64 80 67 / 40 40 70 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM/AVIATION...SEDLOCK LONG TERM/IMPACT WX....CRISTALDI
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
218 AM EDT THU APR 14 2016 .SYNOPSIS... HIGH PRESSURE WILL WEDGE INTO THE FORECAST AREA FROM THE NORTH THROUGH SATURDAY. A FRONT WILL BE STALLED JUST SOUTH OF THE AREA. IT WILL BE COOL WITH POSSIBLE SHOWERS...MAINLY FRIDAY AND FRIDAY NIGHT AND IN THE SOUTH SECTION OF THE FORECAST AREA. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE NORTH WILL CONTINUE TO DOMINATE. SATELLITE TRENDS INDICATED AN INCREASE IN MOISTURE WILL OCCUR AHEAD OF A MID-LEVEL SHORTWAVE TROUGH NOW ALONG THE GULF COAST. WEAK ISENTROPIC LIFT WILL INCREASE MAINLY OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA. LATEST REGIONAL RADAR COMPOSITE SHOWING MOSTLY LIGHT RAIN OVER PORTIONS OF CENTRAL AND SOUTHERN GA...WITH SOME LIGHT RAIN EDGING CLOSE TO THE CSRA. HOWEVER...NOT SURE IF THIS LIGHT PRECIPITATION NEAR THE CSRA IS REACHING THE GROUND AT THIS TIME. THE LATEST SPC HRRR DISPLAYED RAIN REACHING THE SAVANNAH RIVER TOWARDS SUNRISE. AT THIS TIME DO NOT PLAN ANY CHANGES TO POPS SINCE ONGOING FORECAST LOOKS GOOD. THE MAV AND MET MOS PLUS SREF MEAN SUPPORTED CHANCE POPS IN THE SOUTHERN COUNTIES LATE...WHICH LOOKS REASONABLE. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... CONSIDERABLE UNCERTAINTY IN THE SHORT TERM PERIOD...ESPECIALLY THROUGH FRIDAY NIGHT...IN TERMS OF SHOWER COVERAGE AND THEREFORE TEMPERATURES WITH LARGE GRADIENTS IN BOTH EXPECTED ACROSS THE AREA. THURSDAY...A CLOSED UPPER LEVEL LOW WILL SLOWLY SHIFT ACROSS THE LOWER/MIDDLE MISSISSIPPI VALLEY AS A WEDGE OF HIGH PRESSURE AT THE SURFACE MAINTAINS A COOL NORTHEAST FLOW ACROSS THE AREA. DEEPENING MOISTURE PROFILES AND STRENGTHENING ISENTROPIC ASCENT COULD SUPPORT ISOLATED TO SCATTERED SHOWERS ACROSS THE CSRA AND SOUTHERN MIDLANDS...WITH DRIER LOW LEVEL AIR PREVENTING ANY SHOWERS FROM DEVELOPING FARTHER NORTH. TEMPERATURES WILL ONLY REACH HIGHS IN THE LOWER 60S ACROSS SOUTHERN AREAS WHERE THE SHOWER POTENTIAL IS GREATEST...AND MID 60S ACROSS CENTRAL AND NORTHERN AREAS. THURSDAY NIGHT THROUGH FRIDAY NIGHT...A DEVELOPING COASTAL TROUGH COMBINED WITH THE PERSISTENT WEDGE OF HIGH PRESSURE BUILDING FROM THE NORTH WILL RESULT IN A TIGHT SURFACE PRESSURE GRADIENT ACROSS THE AREA...WITH BREEZY NORTHEAST WINDS AT TIMES. THE FORMATION OF THE COASTAL TROUGH WILL ALLOW THE DEEP LAYERED MOISTURE TO ADVECT NORTHWARD INTO THE AREA. MEANWHILE IN THE UPPER LEVELS OF THE ATMOSPHERE...AN OMEGA BLOCK WILL FORM...HOLDING THE CLOSED LOW JUST TO THE WEST. THE COMBINATION OF ABUNDANT MOISTURE...FORCING FOR ASCENT AHEAD OF THE CLOSED LOW AND ISENTROPIC LIFT WILL RESULT IN UNSETTLED CONDITIONS...WITH SHOWERS LIKELY ACROSS THE CSRA AND A CHANCE OF SHOWERS JUST ABOUT EVERYWHERE ELSE ACROSS THE FORECAST AREA. NIGHTTIME LOWS WILL BE IN THE 40S...BUT DAYTIME HIGHS ON FRIDAY COULD RANGE FROM THE MID AND UPPER 50S IN THE CSRA AND LOWER MIDLANDS TO THE LOWER AND MID 60S ACROSS THE CENTRAL AND NORTHERN MIDLANDS. SATURDAY...THE UPPER LEVEL LOW WILL WEAKEN AND SHIFT SOUTH AND SOUTHEAST OF THE AREA...WHILE AT THE SURFACE THE CENTER OF HIGH PRESSURE WILL SHIFT SOUTH INTO THE MID-ATLANTIC REGION AND SHUNT THE DEEPEST MOISTURE OUT OF THE AREA. ANY LINGERING ISOLATED SHOWERS ACROSS THE CSRA SHOULD TAPER OFF IN THE MORNING...WITH CLEARING SKIES IN THE AFTERNOON. THE NORTHEAST FLOW WILL KEEP COOL TEMPERATURES IN PLACE HOWEVER...WITH HIGHS GENERALLY IN THE MID 60S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... UPPER LEVEL RIDGING WILL STRENGTHEN TO THE WEST AS SURFACE HIGH PRESSURE INITIALLY BUILDS OVER THE REGION THEN SHIFTS INTO THE WESTERN ATLANTIC LATE IN THE PERIOD. STRONG SUBSIDENCE AND A LACK OF DEEP MOISTURE WILL RESULT IN RAIN-FREE CONDITIONS. TEMPERATURES WILL ALSO WARM THROUGH THE PERIOD...RISING ABOVE NORMAL BY EARLY NEXT WEEK. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. REMAINS OF A FRONTAL BOUNDARY JUST SOUTH OF THE AREA WILL CONTINUE TO PRODUCE CLOUDY SKIES AND POTENTIAL FOR RAIN SHOWERS. CURRENT RADAR IMAGERY SHOWS ISOLATED RAIN SHOWERS AROUND THE TAF SITES WITH FEW SURFACE OBS INDICATING RAIN REACHING THE GROUND. FRONT WILL REMAIN NEARLY STATIONARY THROUGH THE PERIOD WITH MAIN POTENTIAL FOR SHOWERS AT AGS/DNL...HOWEVER WITH ISOLATED NATURE OF SHOWERS CONFIDENCE IN IMPACTS AT TAF SITES REMAINS TOO LOW TO INCLUDE MENTION. WINDS WILL BE EASTERLY THROUGH THE PERIOD AT 9 KNOTS OR LESS...WITH GUSTS BETWEEN 13Z AND 23Z UP TO 20 KNOTS. EXTENDED AVIATION OUTLOOK...A FRONT WILL REMAIN JUST SOUTH OF THE AREA THROUGH SATURDAY. MOISTURE ASSOCIATED WITH THE FRONT MAY LEAD TO PERIODS OF MVFR OR IFR CONDITIONS...MAINLY AT AGS/DNL. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
254 AM MDT THU APR 14 2016 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 224 PM MDT WED APR 13 2016 LATEST SATELLITE AND UPPER ANALYSIS INDICATE AN UPPER LEVEL TROUGH OVER THE GULF OF ALASKA...A CLOSED LOW OVER THE SOUTHERN PLAINS AND A RIDGE OVER THE CENTRAL AND NORTHERN PLAINS. PATCHY CLEAR SKY WAS SEEN UNDER THE NORTHWEST FLOW AHEAD OF THE TROUGH IN THE GULF OF ALASKA. JUST WEST OF THE TRI-STATE AREA CUMULUS CLOUDS/ISOLATED STORMS WERE BEGINNING TO DEVELOP ALONG A WIND CONVERGENCE LINE. FOR THE REST OF THE AFTERNOON ISOLATED STORMS WILL DEVELOP ALONG THIS WIND CONVERGENCE LINE IN EAST CENTRAL COLORADO. ANY STORMS THAT DO DEVELOP WILL BE MOVING VERY SLOWLY TO THE NORTHEAST. GUSTY WINDS AND LIGHT RAINFALL ARE EXPECTED WITH ANY STORMS THAT DEVELOP. LATE TONIGHT PATCHY FOG WILL DEVELOP OVER THE EASTERN HALF OF THE AREA WHERE THE HIGHER DEW POINTS WILL BE. THE HIGHER DEW POINTS WILL KEEP LOWS WARMER THAN LAST NIGHT DESPITE FAVORABLE CONDITIONS FOR RADIATIONAL COOLING. AROUND SUNRISE THURSDAY MORNING THE FOG WILL BE THICKEST. MOST MODELS HAVE THE VISIBILITIES DROPPING TO A FEW MILES...ALTHOUGH A FEW HAVE NEAR ZERO VISIBILITY. CANNOT RULE OUT VISIBILITIES BELOW A MILE...ESPECIALLY IN LOW LYING AREAS. HOWEVER THE SHALLOW DEPTH OF THE SATURATED LAYER DOES NOT GIVE MUCH CONFIDENCE THE VISIBILITY WILL BE LESS THAN A MILE. THE FOG WILL BURN OFF BY MID MORNING. LATE MORNING THROUGH THE AFTERNOON SOUTH WINDS WILL QUICKLY INCREASE...WITH GUSTS OF 30-40 MPH EXPECTED BY MID AFTERNOON. THE WINDS ARE NOT EXPECTED TO BEGIN DECLINING UNTIL THE EVENING HOURS DUE TO THE PERSISTENT SHALLOW MIXED LAYER ALLOWING THE STRONGER WINDS TO REACH THE GROUND. CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED. SEE FIRE WEATHER SECTION FOR FURTHER INFORMATION. DURING THE AFTERNOON ISOLATED STORMS MAY DEVELOP ALONG THE DRY LINE NEAR THE STATE LINE. DEEP LAYER SHEAR IS ON THE LOW END FOR SEVERE STORMS TO DEVELOP...BUT DOES INCREASE SLIGHTLY THROUGH THE AFTERNOON. LARGE HAIL TO HALF DOLLAR SIZE IS POSSIBLE WITH THE STRONGEST STORMS ALONG WITH SEVERE WIND GUSTS. ANY STORMS THAT DO DEVELOP WILL BE TIED TO THE DRY LINE...SINCE ANY LIFT ALONG THE DRY LINE QUICKLY DECLINES TO THE EAST. .LONG TERM...(SUNDAY THROUGH WEDNESDAY) ISSUED AT 254 AM MDT THU APR 14 2016 FOR THIS EXTENDED FORECAST PERIOD...WIDESPREAD PRECIPITATION SHOULD STILL BE ONGOING AS A RESULT OF THE LARGE UPPER LOW FORECAST TO IMPACT THE REGION. PRECIPITATION...HEAVY AT TIMES...SHOULD LINGER ACROSS PORTIONS OF THE REGION THROUGH MONDAY. HOWEVER...IMPROVING CONDITIONS CAN BE EXPECTED BEYOND MONDAY AS THE LOW DETERIORATES. WHILE RAINFALL CHANCES SHOULD GRADUALLY DIMINISH...COOL TEMPERATURES AND CLOUD COVER STILL SEEM LIKELY THROUGH TUESDAY. WARMER WEATHER IS FORECAST TO RETURN WEDNESDAY AS PERSISTENT CLOUD COVER FINALLY RECEDES TO THE EAST. ON THURSDAY...A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. THIS SHOULD LEAD TO SOUTH WINDS RETURNING AND THE BEGINNING OF A WARMING TREND. THE MAIN PERIOD OF FOCUS FOR THE EXTENDED FORECAST IS SUNDAY THROUGH MONDAY. WITH THE UPPER LEVEL LOW STILL POSITIONED TO THE SOUTHWEST AND A STEADY FETCH OF MOISTURE FROM THE SOUTHEAST...WIDESPREAD PRECIPITATION CAN BE EXPECTED. RAIN MAY STILL BE HEAVY AT TIMES. HOWEVER...A SUBSTANTIAL LOSS OF INSTABILITY SHOULD LIMIT HEAVIER RAIN RATES AND CONVECTION. PRIOR HEAVY PRECIPITATION AND FLOODING PROBLEMS...IF ANY...COULD BE AGGRAVATED BY FURTHER PRECIPITATION SUNDAY AND MONDAY. ANOTHER FORECAST ITEM TO MONITOR IS THE POTENTIAL FOR WINTRY WEATHER OVER EAST COLORADO. REMAIN HIGHLY SUSPECT OF TEMPERATURE GUIDANCE AS A LARGE SPREAD BETWEEN SOLUTIONS REMAINS. ATMOSPHERIC COOLING IS LIKELY AS HEAVY PRECIPITATION FALLS BUT WARM AIR ADVECTION FROM THE SOUTHEAST POSES A PROBLEM. AM ALSO UNSURE IF THE SURFACE COLD AIR WILL ADVANCE FAR ENOUGH EAST TO BRING WINTRY WEATHER TO EAST COLORADO. IN ADDITION...SOUNDING PROFILES LOOK QUITE WARM WHICH SHOULD LEAD TO AT LEAST SOME MELTING AS THE SNOW FALLS. WARM GROUND TEMPERATURES POSE YET ANOTHER PROBLEM FOR ANY POTENTIAL SNOW ACCUMULATIONS. ALL THAT SAID...CONTINUE TO DOWNPLAY SNOW POTENTIAL AT THIS POINT BECAUSE OF HIGH UNCERTAINTY...POSITION/MOVEMENT OF THIS LOW AND THE LOCATION/EXTENT OF COLDER AIR MASS. WHERE THAT RAIN/SNOW LINE ENDS UP COULD MEAN THE DIFFERENCE BETWEEN MODERATE/HEAVY RAINS AND MODERATE/HEAVY SNOW. THE MAIN STORY WITH THIS SYSTEM SHOULD BE HEAVY RAIN BUT RESIDENTS AND PARTNERS IN EAST COLORADO SHOULD MONITOR FUTURE FORECASTS IN CASE SNOW BECOMES A BIGGER STORY SUNDAY MORNING AND AGAIN SUNDAY NIGHT/MONDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1030 PM MDT WED APR 13 2016 FOR KGLD AND KMCK...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 09Z OR 10Z WITH WINDS FROM THE SOUTH 8-11KTS AND A CLEAR SKY. FROM 10Z TO 15Z OR 16Z STILL EXPECTING STRATUS AND SOME FOG TO MOVE IN FROM THE SOUTHEAST PRODUCING IFR/VLIFR CONDITIONS. WINDS SLOWLY INCREASING TOWARD 13KTS FROM THE SOUTHEAST. VFR CONDITIONS RETURN FOR THE AFTERNOON WITH WINDS SLOWLY INCREASING FROM THE SOUTH-SOUTHEAST...GUSTS OVER 30KTS LIKELY. THIS SHOULD CONTINUE INTO THE EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...RED FLAG WARNING FROM NOON TODAY TO 7 PM MDT THIS EVENING FOR COZ252>254. NE...NONE. && $$ SHORT TERM...JTL LONG TERM...RRH AVIATION...99
  [top] Area Forecast Discussion National Weather Service Dodge City KS 347 AM CDT THU APR 14 2016 .SHORT TERM...(Today and tonight) Issued at 256 AM CDT Thu Apr 14 2016 Stratus expanding across the area this morning, and it`s potential impacts on the temperature through the day is the immediate weather story. Fog was overdone in the NAM model, and may be overdone as well by the HRRR solutions going forward early this morning. However the expansion of stratus with bases at or under 500 ft continues this morning in a weak moisture advection environment. Going forward this afternoon, the models account for cloud dissipation by having much cooler temperatures in central Kansas. The surface high pressure will continue to shift east of the Mississippi valley, increasing the surface pressure gradient over western KS, and allowing moderate to strong southerly winds to develop especially once mixing maximizes this afternoon. Very low pops are in place tonight, following the convective allowing models reflectivity fields/weak cape and upslope environment with exiting shortwave ridge. however the real increase in precipitation chances comes on Friday afternoon with what could potentially be a few severe thunderstorms given the low to moderate cape values and strong bulk shear. .LONG TERM...(Friday through Wednesday) Issued at 256 AM CDT Thu Apr 14 2016 A well advertised so far thunderstorm/heavy rain event is still the main story in the medium range timeframe. All of the models are consistent in the large upper low stalling over the far southern Rockies/northern New Mexico region from Friday night into Monday morning. The gulf fetch will be wide open for this event, and a persistent rain looks to really get going by late Saturday and not end until early Monday at best. Several inches of rain are likely across most of the forecast area, and even localized flooding possible becoming a reality where rainfall duration and intensity are largest over low lying drainage areas. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1250 AM CDT Thu Apr 14 2016 We will be monitoring trends overnight as stratus expands across the entire area, or at least most of it in moist upslope flow at max radiational cooling timing. The models may be too aggressive in developing fairly widespread dense fog, whereas the GFS local model output stats keep visibility up, likely owing to these moderate surface winds ongoing at this time. A low confidence forecast tonight, with TAF amendments likely. && .PRELIMINARY POINT TEMPS/POPS... DDC 72 53 74 55 / 0 10 30 50 GCK 75 53 74 53 / 10 20 50 60 EHA 80 54 75 52 / 10 10 70 60 LBL 77 53 75 54 / 0 10 50 70 HYS 72 52 74 54 / 0 20 30 50 P28 70 52 76 57 / 0 10 20 30 && .DDC Watches/Warnings/Advisories...NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Russell
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
322 AM CDT THU APR 14 2016 .SHORT TERM... ACTIVE WEATHER DAY ALREADY GETTING STARTED ACROSS THE FORECAST AREA EARLY THIS MORNING. A STALLED FRONTAL BOUNDARY DRAPED ALONG THE LA COAST...ACROSS THE NORTHERN GULF IN GENERAL...WILL BE THE FOCUS FOR THE BULK OF RAINFALL TODAY. RADAR SHOWS SHOWERS AND ISOLATED THUNDERSTORMS BEGINNING TO EXPAND IN COVERAGE MAINLY SOUTH OF A BATON ROUGE TO GULFPORT LINE. MESO AND MEDIUM RANGE MODELS INDICATE THAT CONVECTION WILL SPREAD NORTH AND EAST THROUGHOUT THE MORNING HOURS BEFORE SHIFTING EAST INTO ALABAMA THIS AFTERNOON. DURING THAT TIME...A JET NOSE COMING IN FROM TEXAS IN COMBINATION WITH DAYTIME HEATING...WILL PROMOTE MORE ROBUST THUNDERSTORMS MAINLY IN THE NWRN HALF OF THE CWA. THINKING BATON ROUGE METRO AND INTO SW MISSISSIPPI. BTR AND MCB MODEL SOUNDINGS LOOK PRIMED FOR HAIL PRODUCING STORMS WITH 1000-1500J/KG OF CAPE...LI/S -4 TO -6 AND WBZ HEIGHT OF AROUND 10KFT. WINDS...ALTHOUGH VEERING NICELY FROM SE AT THE SFC TO WEST ALOFT...ARE GENERALLY WEAK IN LOWER LAYERS AND THUS POSE A MINIMAL THREAT FOR DAMAGING WINDS AND/OR TORNADO DEVELOPMENT. SO THINKING HAIL WILL BE THE MAIN HAZARD TODAY. THE HRRR DOES INDICATE CELLULAR DEVELOPMENT IN THE 18-20Z TIME FRAME SO WILL HAVE TO MONITOR FOR POSSIBLE SVR WARNINGS. UPPER LEVEL LOW CENTER NORTH OF THE AREA WILL BEGIN TO BREAK DOWN FRIDAY WHILE RIDGE BEGINS TO BUILD IN THE AREA FROM THE WEST ON FRIDAY. THIS WILL CAUSE A EASTWARD SHIFT IN CONVECTION. FOR NOW HAVE POPS RANGING FROM 30S IN SWRN ZONES TO NEAR 50 PERCENT IN SW AND COASTAL MISSISSIPPI. THAT MAY BE SLIGHTLY GENEROUS. RAIN CHANCES LOOK TO DROP CONSIDERABLY SATURDAY AND SUNDAY AS THE WEAK RIDGE SLIDES OVERHEAD WITH NEXT CLOSED LOW STATIONARY OVER THE 4-CORNERS REGION. && .LONG TERM... UPPER LEVEL RIDGE OVER THE AREA THIS WEEKEND WILL SPREAD NORTH TO THE GREAT LAKES BY EARLY NEXT WEEK. THIS WILL BRING HIGH TEMPS BACK UP INTO THE UPPER 70S SUNDAY INTO MONDAY. A TROUGH DIPPING ACROSS THE NORTHEAST WILL SUPPRESS THE RIDGE SOUTH ON TUESDAY AND KEEP IT THERE THE REMAINDER OF THE WEAK. MEANWHILE...CLOSED LOW TO THE WEST WILL OPEN INTO MORE OF AN OPEN WAVE AS IT SLOWLY PROGRESSES EASTWARD ACROSS THE CENTRAL PLAINS. THIS MOVEMENT COULD TAKE THE ENTIRE WEEK TO TAKE PLACE. LOCAL RAIN CHANCES WILL BEGIN TO INCREASE DURING THIS TIME WITH SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. MEFFER && .AVIATION... SH/TS WILL DEVELOP AND MOVE NORTHEAST THROUGH THE AREA TODAY. MOST OF THIS ACTIVITY SHOULD AFFECT TERMINALS OVER THE SOUTHERN HALF OF THE AREA TODAY. WILL KEEP PREVAILING TS GROUPS FOR TERMINALS MAINLY ALONG AND SOUTH OF I-10/12. CEILINGS WILL ALSO BE AT SEVERAL DIFFERENT LEVELS BREAKING AND COVERING THROUGHOUT THE DAY. EXPECT MOST TO BE FROM BKN008-015 AND SOME TO BE AT OVC030. CEILINGS SHOULD FALL TO AROUND OVC005 AGAIN TONIGHT. && .MARINE... SH/TS WILL BE THE BIGGEST CONCERN TODAY AND FRIDAY.SOME OF THESE COULD BECOME SEVERE TODAY. WINDS AND SEAS WILL BE HIGHEST NEAR THIS ACTIVITY. THE CURRENT TROUGH AXIS THAT HAS SETTLED OVER THE GULF WILL HELP A VERY WEAK SFC LOW DEVELOP THROUGH TONIGHT. HIGH PRESSURE WILL INTERACT WITH THIS LOW AS IT RIDGES SOUTHWEST INTO THE NORTHERN GULF CAUSING A STRONGER GRADIENT FLOW TO SET UP STARTING THURSDAY NIGHT THROUGH THE WEEKEND. WINDS SHOULD BE EAST AT 15 TO 20 KNOTS BY THURSDAY NIGHT OVER WATERS EAST OF THE MISS RIVER AND GRADUALLY WORK THEIR WAY WESTWARD INTO THE REMAINING WATERS WEST OF THE RIVER BY FRIDAY EVENING. WINDS SHOULD EASE BACK SOMEWHAT BY THE START OF NEXT WEEK. && .DECISION SUPPORT... DSS CODE....GREEN. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...MINOR RIVER FLOODING. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 75 60 71 58 / 70 70 50 20 BTR 77 62 74 61 / 70 40 40 20 ASD 76 63 72 61 / 80 60 50 20 MSY 75 65 74 64 / 80 60 40 20 GPT 73 62 70 60 / 80 70 50 20 PQL 74 60 71 59 / 80 70 50 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
448 AM CDT THU APR 14 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 440 AM CDT THU APR 14 2016 WARM FRONT THAT REMAINED WELL DEFINED THROUGH THE DAY YESTERDAY AND THROUGH MUCH OF LAST NIGH WAS FINALLY STARTING TO BECOME LESS DEFINED IN THE WIND FIELD...THOUGH WAS STILL IDENTIFIABLE ACROSS CENTRAL MN. SOUTH OF THIS BOUNDARY...TEMPERATURES OVERNIGHT HAVE MOSTLY REMAINED ABOVE 50. AS WE GO THROUGH THE DAY...A 995 MB LOW WILL DEVELOP NEAR THE ND/SD/WY/MT REGION...WHICH PUT A MORE SRLY PRESSURE GRADIENT ACROSS THE AREA AND FINALLY FORCE WHAT IS LEFT OF THE WARM FRONT UP INTO NRN MN. THIS STRENGTHENING SRLY FLOW WILL ADVECT A LOW LEVEL THERMAL RIDGE INTO WRN MN ALONG ROUGHLY AN ABERDEEN TO BEMIDJI LINE. WITHIN THIS THERMAL RIDGE...WE REMAIN CONFIDENT IN HIGHS REACHING TO THE LOW 80S WEST OF A GRANITE FALLS TO STAPLES LINE. IN ADDITION...BASED ON A RAP/GFS MIXED LAYER DEWPOINTS...THIS PORTION OF WESTERN MN LOOKS TO GET CAUGHT BETWEEN AREAS OF SLIGHTLY HIGHER DEWPOINTS TO THEIR NORTH /NORTH OF THE WARM FRONT/ AND TO THE EAST AS AIR WITH SFC DEWPOINTS CURRENTLY IN THE MID 40S IN ERN NEB LOOKS TO GET ADVECTED UP TOWARD THE TWIN CITIES TODAY. THESE SLIGHTLY LOWER DEWPOINTS COINCIDING WITH HIGHS IN THE LOW 80S RESULTED IN A FAIRLY BROAD AREA WHERE MINIMUM HUMIDITIES ARE FORECAST TO GET DOWN BETWEEN 20 AND 25 PERCENT. INCIDENTALLY...THIS IS ALSO WHERE THE SPC INCLUDED AN ELEVATED AREA ON THE DAY 1 FIRE WEATHER RISK MAP...SO AFTER COORDINATION WITH MIFC ALONG WITH ABR/FSD/FGF...WE ENDED UP WITH THE RFW SEEN FROM 18Z THROUGH 00Z THIS AFTERNOON. FOR THE REST OF MN...WE HAVE HUMIDITY VALUES FORECAST TO GET DOWN TO BETWEEN 25 AND 35 PERCENT WITH SUSTAINED WINDS MORE 15 TO 25 MPH WITH GUSTS TO 30 MPH. THEREFORE OUTSIDE OF THE WARNING...AFTER COORDINATION WITH ARX/DLH...WILL HAVE A SPECIAL WEATHER STATEMENT FOR THE INCREASED FIRE DANGER ACROSS THE REST THE MPX MN COUNTIES. MAIN AREA OF LOWER CONFIDENCE TODAY IS WITH THE DEWPOINT FORECAST AND ATTENDANT HUMIDITY LEVELS. CURRENT FORECAST IS CERTAINLY ON THE LOW END OF THE DEWPOINT ENVELOP...BUT IN LINE WITH WHAT THE HRRR AND HOPWRF ARE SHOWING. IF THERE IS AN AREA THIS FORECAST GOOD BE A BUST IT IS WITH THE LOW HUMIDITY. HOWEVER...OVER THE LAST WEEK...WE HAVE HAD A COOL TEMPERATURE AND MOIST RH BIAS...SO FEEL CONFIDENT IN THE CURRENT SCENARIO DEPICTED IN THE GRIDS. FOR TONIGHT...IT WILL BE ANOTHER MILD NIGHT...WITH LOWS SIMILAR TO WHAT WE HAVE SEEN TO SOUTH OF THE WARM FRONT OVERNIGHT...UPPER 40S TO LOWER 50S THANKS TO SRLY WINDS CONTINUING TO BLOW. IN ADDITION...THE STRENGTHENING OF THE UPPER RIDGE OVER THE GREAT LAKES WILL HELP PUSH ANY CLOUDS/PRECIP EVEN FARTHER WEST OF WHAT WE WILL SEE TODAY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 440 AM CDT THU APR 14 2016 IT MAY BE TORNADO TEST DAY IN MN/WI...BUT THE WARM AND DRY WEATHER IS HERE TO STAY THROUGH SATURDAY GIVEN THE OMEGA BLOCK IN THE ATLANTIC. THE BLOCKING PATTERN IS KEEPING THE NE CONSUS/EASTERN CANADIAN TROUGH IN PLACE...AND FARTHER UPSTREAM THE RIDGING IN PLACE ACROSS THE LOCAL AREA. HIGH TEMPERATURES IN THE 70S WILL BE THE RESULT LOCALLY FRI- SAT. A TROUGH MOVES INLAND OVER THE PACIFIC NORTHWEST TODAY...BUT DROPS ACROSS THE SOUTHWEST CONUS AND BECOMES CUTOFF FROM THE MAIN FLOW - THE 14.00Z GFS AND ECMWF CONTINUE TO KEEP THE UPPER LOW SPINNING AWAY DOWN ACROSS THE SOUTHWEST THROUGH EARLY NEXT WEEK BEFORE EVENTUALLY FILLING AND SHEARING OUT. THE SURFACE TROUGH AND COLD FRONT ASSOCIATED WITH THIS FEATURE WILL REMAIN IN THE DAKOTAS THROUGH FRIDAY...BUT THE LATEST GUIDANCE DOES TRY TO BRING THE BOUNDARY INTO THE FAR WESTERN FORECAST AREA ON SATURDAY...AND KEEPS IT THERE UNTIL SUNDAY...BEFORE SAGGING IT E-SE SUNDAY NIGHT INTO MONDAY. A FEW SHOWERS ARE POSSIBLE ON SATURDAY IN FAR WESTERN MINNESOTA DUE TO THE PRESENCE OF THIS BOUNDARY. THE REST OF THE FORECAST AREA COULD SEE RAIN SUNDAY AFTERNOON - SUNDAY NIGHT WHEN THIS BOUNDARY IS DRIVEN SOUTH BY A SHORTWAVE COMING OUT OF CANADA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1204 AM CDT THU APR 14 2016 VERY QUIET PERIOD AHEAD. SOUTH/SOUTHEASTERLY WINDS WILL CONTINUE AND BECOME GUSTY TOMORROW DURING THE DAY. THOSE GUSTS SHOULD DIMINISH NEAR SUNSET TOMORROW NIGHT. OTHERWISE MAINLY CLEAR SKIES...OTHER THAN A FEW TO SCATTERED MID LEVEL CLOUDS IN EASTERN MN AND WESTERN WI DURING THE DAY TOMORROW. KMSP...NO CHANGE FROM MAIN FORECAST. COULD GET CLOSE TO 30 KNOT WS CRITERIA EARLY THURSDAY MORNING FOR A FEW HOURS...BUT THINKING AT THIS TIME IS IT WONT QUITE REACH CRITERIA. /OUTLOOK FOR KMSP/ FRI...VFR. WINDS SSE 10-20 KTS. SAT...VFR. WINDS S 10-15 KTS. SUN...MVFR CIG POSSIBLE. WINDS S BCMG NE 5 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR MNZ041-042-047>049-054>057-064. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...SPD
AREA FORECAST DISCUSSION
NWS DULUTH MN
413 AM CDT THU APR 14 2016 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 413 AM CDT THU APR 14 2016 AM ELONGATED AREA OF LOW PRESSURE STRETCHED FROM CENTRAL SASKATCHEWAN EAST SOUTHEAST THROUGH THE DAKOTAS EARLY THIS MORNING. A FRONTAL BOUNDARY ALSO WAS OCCURRING IN THIS AREA. A WARM FRONT STRETCHED FROM SOUTH DAKOTA INTO SOUTHERN MINNESOTA. AN UPPER RIDGE OVER THE NORTHLAND EARLY THIS MORNING WILL SHIFT EAST AS A SHORTWAVE AND THE LOW PRESSURE SYSTEM ALL MOVE EAST...WITH THE WARM FRONT LIFTING NORTH INTO NORTHERN MINNESOTA BY THIS EVENING. WARM AIR ADVECTION WILL CONTINUE TODAY AND GIVE A BOOST TO TEMPERATURES. WE SHOULD SEE CLOUDS GRADUALLY INCREASE...MAINLY OVER WESTERN AND NORTHERN AREAS WHICH WILL BE IMPACTED BY THE LOW/FRONTS. WE HAVE A CHANCE FOR AFTERNOON SHOWERS OVER THE FAR NORTHWEST LATE TODAY...AND GENERALLY NORTH OF HIGHWAY 2 IN MINNESOTA THIS EVENING. THERE COULD ALSO BE A RUMBLE OR TWO OF THUNDER. WE INCREASED TEMPERATURES ACROSS MUCH OF THE AREA...BUT ESPECIALLY OVER WESTERN AREAS WHICH WILL BE IN OR NEAR A THERMAL RIDGE. GOOD MIXING WILL ALSO HELP ON WARMING TEMPERATURES AND WILL RESULT IN GUSTY WINDS AS WELL. WE HAVE HIGHS IN THE MID TO UPPER SEVENTIES FROM THE BRAINERD LAKES AREA NORTH TO THE LAKE WINNIE AREA...AND SIXTIES ACROSS NORTHWEST WISCONSIN. THE NORTH SHORE WILL BE MUCH COOLER AND WE KEPT ONSHORE WINDS IN THE TWIN PORTS AREA THROUGH MUCH OF THE AFTERNOON. THE NAM AND LOCAL WRF MODEL SHOW EASTERLY WINDS...NOT AS STRONG AS YESTERDAY...CONTINUING THROUGH LATE AFTERNOON BEFORE THE GRADIENT STRENGTHENS ENOUGH TO GET SOUTHERLY WINDS TO MIX TO THE SURFACE. WE EXPECT A TIGHT THERMAL GRADIENT ACROSS THE TWIN PORTS...WITH UPPER FORTIES ON PARK POINT TO LOWER SIXTIES OVER THE HILL. SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE OVER FAR NORTHERN MINNESOTA THIS EVENING...THEN THE WARM FRONT WILL PUSH NORTH OF THE INTERNATIONAL BORDER BRINGING AN END TO ANY RAIN CHANCES. THE LOW WILL MAKE MORE PROGRESS EAST ON FRIDAY...ENOUGH TO BRING A CHANCE FOR MORE SHOWERS TO FAR WESTERN AREAS OF THE NORTHLAND DURING THE AFTERNOON. MOST AREAS WILL SEE HIGHS IN THE MID SIXTIES TO LOWER SEVENTIES. THE NORTH SHORE WILL BE COOLER AS WILL LAKESIDE AREAS IN THE TWIN PORTS AREA. .LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 413 AM CDT THU APR 14 2016 MAIN FOCUS IN THE LONG TERM WILL BE AN INCOMING COLD FRONT BRINGING A CHANCE OF RAIN AND ISOLATED THUNDERSTORMS TO THE NORTHLAND THIS WEEKEND. BEGINNING 00Z SATURDAY... EXPANSIVE UPPER LEVEL HIGH PRESSURE ACROSS THE OHIO RIVER VALLEY WILL KEEP THE NORTHLAND ON THE RECEIVING END OF MOIST SOUTHERLY FLOW WITH MIXING RATIOS NEAR 8G/KG PERSISTING THROUGH THE WEEKEND. THIS WILL BRING AVERAGE TO ABOVE AVERAGE TEMPS ALONG WITH A RIBBON OF INSTABILITY TO THE UPPER MIDWEST AS INDICATED BY SPC`S SREF MLCAPE FCST. SFC LOW PRESSURE SYSTEM AND COLD FRONT WILL TAKE ITS TIME TO APPROACH THE CWA FROM NW MN... BUT WILL SPREAD ISOLATED TO SCATTERED SHOWERS AHEAD OF IT ALONG WITH THE CHANCE OF THUNDERSTORMS SATURDAY AFTERNOON AND EVENING. THE FRONT WILL SLIDE SOUTH OF THE CWA 18Z MONDAY AND DEEP LAYERED RIDGING WILL BUILD BEHIND IT ACROSS THE UPPER MIDWEST. CAA ON THE BACK SIDE OF THE SYSTEM ALONG WITH LIGHT WINDS WILL DROP MIN TEMPS TO AROUND FREEZING ACROSS THE IRON RANGE AND BORDERLAND MONDAY AND TUESDAY MORNINGS. OTHERWISE... THE EXTENDED FCST LOOKS TO REMAIN ON THE BALMY SIDE WITH HIGHS GENERALLY IN THE 50S AND 60S AND COOLER BY THE LAKE (PARTICULARLY SATURDAY WITH A LONG FETCH OF STRONG EASTERLY FLOW ALONG THE NORTH SHORE). && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1252 AM CDT THU APR 14 2016 VFR CONDITIONS EXPECTED THROUGH THE UPCOMING TAF WITH A BRIEF PERIOD OF MVFR VISBY AND POSSIBLE LOW CIGS AT KDLH. THE RIDGE OF HIGH PRESSURE WILL SLIDE OFF TO THE EAST LATE TONIGHT AND ON THURSDAY. STILL UNCERTAIN ON IF FOG WILL DEVELOP AT KDLH ALONG WITH IFR CIGS DUE TO EASTERLY FLOW. TRIED TO TIME THIS POSSIBILITY WITH THE LATEST TIME LAGGED RAP ENSEMBLE. THE OTHER CONCERN OVERNIGHT IS LLWS AT KHIB/KBRD/KHYR DUE TO THE LOW LEVEL JET PER THE LATEST RAP/HRRR/NAM SOUNDINGS. GUSTY WINDS WILL DEVELOP THURSDAY AFTERNOON AS THE MIXED LAYER TAPS INTO THE STRONGER FLOW ALOFT. LATE IN THE TAF PERIOD...LLWS WILL BE A CONCERN AT ALL SITES EXCEPT FOR KDLH/KHYR WHERE THE MIXED LAYER MAY NOT DECOUPLE AS HINTED BY THE LATEST GFS/NAM. && .PRELIMINARY POINT TEMPS/POPS... DLH 61 42 64 50 / 0 0 0 10 INL 60 45 67 51 / 40 40 10 60 BRD 75 48 70 54 / 0 0 10 30 HYR 66 43 68 51 / 0 0 0 0 ASX 65 43 67 47 / 0 0 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 9 AM CDT FRIDAY FOR LSZ140. && $$ SHORT TERM...MELDE LONG TERM...MCLOVIN AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
1252 AM CDT THU APR 14 2016 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 254 PM CDT WED APR 13 2016 RELATIVELY QUIET IN THE SHORT TERM TODAY WITH AN INVERTED TROUGH EXTENDING UP FROM SOUTHERN SOUTH DAKOTA EAST INTO CENTRAL MINNESOTA. THIS HAS PRODUCED EAST TO SOUTHEAST WINDS OVER THE FORECAST AREA WITH SOME GUSTINESS UP TO 20 MPH OVER NORTHWEST WISCONSIN...AND EVEN MORE SO OVER LAKE SUPERIOR. THIS INVERTED TROUGH WILL DEVELOP INTO A WARM FRONT AND PUSH NORTH TONIGHT AND THURSDAY...WITH WARMER AND MORE HUMID AIR PUSHING INTO THE AREA FROM THE SOUTH. LOW TEMPERATURES TONIGHT WILL DIP INTO THE LOW TO MID 30S NEAR AND NORTH OF THE FRONT...WITH VALUES CLOSER TO 40 FARTHER SOUTH. THURSDAY WILL BE WARM AND DRY FOR MOST OF THE AREA...WITH ONLY SOME SMALL CHANCES FOR SHOWERS IN OUR FAR NORTHWEST DURING THE AFTERNOON IN THE VICINITY OF THE FRONT. THE MAIN CONCERN WILL BE IF THERE WILL BE ENOUGH MOISTURE IN PLACE TO GENERATE THE SHOWERS...OR IF IT WILL BE FOCUSED FARTHER NORTH. FOR MOST OF THE AREA SOUTH OF THE BOUNDARY IT WILL BE WARMER AND DRIER WITH HIGHS IN SOME PLACES RISING INTO THE LOW 70S...WITH 60S ELSEWHERE. OF COURSE...WITH LOW PRESSURE TO OUR WEST THE LAKE BREEZE WILL PRODUCE MUCH COOLER AND BREEZIER CONDITIONS NEAR LAKE SUPERIOR...WITH HIGHS IN SOME PLACES STILL ONLY IN THE 40S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 254 PM CDT WED APR 13 2016 THE MAIN CONCERN FOR THE LONG TERM IS POSSIBILITY OF RAIN SHOWERS FRIDAY NIGHT THROUGH SUNDAY. AFTER THE WEEKEND...AN AREA OF HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH MID-WEEK. SOUTHERLY FLOW WILL CONTINUE THE REGION. A WEAK FRONT WILL REMAIN WEST OF THE AREA BUT BEGIN TO SLOWLY MOVE EAST THROUGH SUNDAY. IT WILL REACH THE WESTERN REGIONS OF THE FORECAST AREA BY SATURDAY MORNING AND NORTHWEST WISCONSIN BY THE EVENING. THERE WILL BE SOME MOISTURE INCREASING INTO THE AREA SO THERE WILL BE A POSSIBILITY FOR RAIN SHOWERS ACROSS THE WESTERN PORTIONS OF THE FORECAST AREA FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON...SPREADING ACROSS THE REGION SATURDAY NIGHT AND SUNDAY. THE RAIN TAPERS OFF SATURDAY NIGHT AS AN AREA OF HIGH PRESSURE BUILDS INTO THE REGION. THE HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH MIDDAY WITH HIGHS IN THE UPPER 50S TO LOWER 60S AWAY FROM THE LAKE...UPPER 40S TO MIDDLE 50S ALONG THE LAKE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1252 AM CDT THU APR 14 2016 VFR CONDITIONS EXPECTED THROUGH THE UPCOMING TAF WITH A BRIEF PERIOD OF MVFR VISBY AND POSSIBLE LOW CIGS AT KDLH. THE RIDGE OF HIGH PRESSURE WILL SLIDE OFF TO THE EAST LATE TONIGHT AND ON THURSDAY. STILL UNCERTAIN ON IF FOG WILL DEVELOP AT KDLH ALONG WITH IFR CIGS DUE TO EASTERLY FLOW. TRIED TO TIME THIS POSSIBILITY WITH THE LATEST TIME LAGGED RAP ENSEMBLE. THE OTHER CONCERN OVERNIGHT IS LLWS AT KHIB/KBRD/KHYR DUE TO THE LOW LEVEL JET PER THE LATEST RAP/HRRR/NAM SOUNDINGS. GUSTY WINDS WILL DEVELOP THURSDAY AFTERNOON AS THE MIXED LAYER TAPS INTO THE STRONGER FLOW ALOFT. LATE IN THE TAF PERIOD...LLWS WILL BE A CONCERN AT ALL SITES EXCEPT FOR KDLH/KHYR WHERE THE MIXED LAYER MAY NOT DECOUPLE AS HINTED BY THE LATEST GFS/NAM. && .PRELIMINARY POINT TEMPS/POPS... DLH 34 60 42 57 / 0 10 10 0 INL 35 63 45 67 / 0 30 40 0 BRD 39 73 48 70 / 0 0 0 0 HYR 37 66 43 67 / 0 0 0 0 ASX 29 65 43 63 / 0 0 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...NONE. && $$ SHORT TERM...LE LONG TERM...STEWART AVIATION...WL
AREA FORECAST DISCUSSION
NWS HASTINGS NE
455 AM CDT THU APR 14 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 455 AM CDT THU APR 14 2016 ALTHOUGH THE MAJORITY OF THESE NEXT 24 HOURS SHOULD REMAIN RAIN- FREE (ESPECIALLY THROUGH MIDNIGHT) AND ALSO BREEZY TO WINDY...THERE ARE 2 MAIN FORECAST ISSUES TO CONTEND WITH: 1) IN THE VERY NEAR TERM...ALTHOUGH IT IS BECOMING INCREASINGLY- OBVIOUS FROM SATELLITE TRENDS THAT MUCH OF THE SOUTHERN TWO-THIRDS (IF NOT MORE) OF THE CWA WILL START THE DAY WITH AT LEAST A FEW HOURS OF CLOUDY/MOSTLY CLOUDY SKIES UNDER A DECK OF LOW STRATUS CLOUDS...THE JURY IS STILL VERY MUCH ON OUT REGARDING WHETHER OR NOT FOG REMAINS NOTHING MORE THAN A LIGHT NUISANCE...OR ACTUALLY ENDS UP BECOMING THICKER/MORE DENSE ON AT LEAST A LOCALIZED BASIS. 2) LATE TONIGHT (MAINLY AFTER 1 AM)...WILL MAINTAIN LOW (20-30 PERCENT) PRECIP CHANCES/POPS FOR SHOWERS AND ISOLATED WEAK THUNDERSTORMS ACROSS MOST OF THE CWA...AND ACTUALLY NUDGED THESE LOW RAIN CHANCES A BIT FARTHER EAST CLOSER TO THE HIGHWAY 14 CORRIDOR. STARTING WITH THE HERE-AND-NOW AS OF 09Z/4AM..."NUMBER 1" ABOVE IS CLEARLY THE ONGOING FORECAST HEADACHE REGARDING LOW STRATUS/POSSIBLE FOG TRENDS OVER THE NEXT 6 HOURS OR SO. AS IS OFTEN THE CASE...SOME MODELS/SETS OF GUIDANCE ARE PERFORMING FAR BETTER THAN OTHERS AT CAPTURING THE NORTHWARD DEVELOPMENT OF LOW STRATUS OUT OF CENTRAL KS INTO OUR CWA...AND EVEN SOME THAT DO ACKNOWLEDGE ITS DEVELOPMENT ARE STILL NOTICEABLY TOO HIGH WITH THE CLOUD CEILING. AS OF THIS WRITING...THIS AREA OF LOW STRATUS (WITH A HEIGHT OF ONLY AROUND 600 FT) HAS INFILTRATED MUCH OF OUR KS ZONES...AND IS EXPECTED TO CONTINUE MAKING STEADY PROGRESS NORTH OF THE STATE LINE BETWEEN NOW AND SUNRISE. MEANWHILE...CLEAR SKIES AT LEAST TEMPORARILY CONTINUE TO RULE THE NEBRASKA CWA. IN THE BIG PICTURE OF THE MID-UPPER LEVELS...VERY WEAK/BENIGN FLOW PERSISTS OVER THE LOCAL AREA UNDER THE LINGERING INFLUENCE OF A BROAD RIDGE...WITH THE LOCAL AREA WELL TO THE NORTHWEST OF A VERY SLOW MOVING LOW CENTERED OVER THE MO/OK/AR BORDER AREA...AND STILL WELL TO THE EAST OF THE WELL-ADVERTISED LARGE-SCALE LOW MOVING INTO THE WESTERN CONUS THAT WILL PROVIDE THE MULTIPLE RAIN CHANCES OUTLINED IN THE LONG TERM SECTION BELOW. AT THE SURFACE...A MODEST PRESSURE GRADIENT PERSISTS BETWEEN A ROUGHLY 1006 MILLIBAR LOW CENTERED OVER SD AND HIGH PRESSURE SPRAWLED OUT OVER THE EASTERN CONUS. AS A RESULT...BREEZES ARE CURRENTLY SOUTHERLY AT GENERALLY 7-12 MPH ACROSS MOST OF THE CWA. OVERNIGHT LOW TEMPERATURES ARE ON TRACK TO BOTTOM OUT GENERALLY 47-50...WHICH IS ROUGHLY 10 DEGREES ABOVE AVERAGE. NOW LOOKING AHEAD FORECAST-WISE THROUGH SUNRISE FRIDAY MORNING: EARLY THIS MORNING (THROUGH ROUGHLY SUNRISE): ALL EYES ARE ON THE NORTHWARD-MOVING LOW STRATUS EVIDENT ON SATELLITE IMAGERY AS IT CONTINUES PUSHING OUT OF KS INTO NEB ZONES. FOLLOWING THE USUAL MOST-RELIABLE VERY NEAR-TERM SOLUTIONS OF THE RAP13 AND HRRR MODELS...THESE LOW CLOUDS SHOULD MAKE IT UP TO ROUGHLY THE I-80 CORRIDOR IF NOT A BIT FARTHER NORTH BY 12Z/7AM. ALTHOUGH SOME VERY LIGHT FOG IS PROBABLE ESPECIALLY NEAR THE LEADING EDGES OF THIS CLOUD MASS...THE BIG QUESTION IS WHETHER OR NOT ANY FOG COULD BECOME MORE DENSE. THE LATEST HRRR/RAP13 VISIBILITY PROGS STILL SHOW THIS COULD BE POSSIBLE ON AT LEAST A LOCALIZED BASIS...BUT WOULD TEND TO THINK THAT THE LIGHT-BUT- STEADY SOUTHERLY BREEZES SHOULD HELP MITIGATE TRULY IMPACTFUL FOG PROBLEMS. WILL CONTINUE TO CARRY A MIX OF "PATCHY" AND "AREAS" OF FOG IN FORECAST PRODUCTS...BUT WILL REFRAIN FROM SPECIFYING ANY PRONOUNCED VISIBILITY REDUCTIONS UNLESS/UNTIL THEY SHOW THEIR HAND. TODAY (SUNRISE THROUGH SUNSET): IN SHORT...ANOTHER DRY AND SEASONABLY WARM DAY THAT IF ANYTHING SHOULD AVERAGE ROUGHLY 5 MPH WINDIER THAN YESTERDAY. PROBABLY THE BIGGEST UNCERTAINTY LIES WITH EXACTLY WHEN THE ONGOING/INCOMING LOW STRATUS CLOUDS BURN OFF/DISSIPATE. AGAIN FOLLOWING THE RAP/HRRR SOLUTIONS MORE CLOSELY THAN ANYTHING (INCLUDING LOW LEVEL CLOUD PRODUCTS AND 925/900 MILLIBAR RH)...FAIRLY EXPANSIVE LOW CLOUDS SHOULD REACH UP TO AROUND HIGHWAY 92 AND POSSIBLY EVEN A BIT FARTHER BY THE 7-9 AM TIME FRAME...BEFORE A STEADY EROSION/DISSIPATION GETS UNDERWAY BY 10 AM WITH MAYBE ONLY A LITTLE LINGERING STRATUS IN FAR WESTERN ZONES BY ROUGHLY 11 AM AND THEN MOSTLY SUNNY SKIES CWA-WIDE BY NOON AT THE LATEST. AT LEAST THAT`S THE GENERAL EXPECTATION...AGAIN FOR A CLOUDY/MOSTLY CLOUDY MORNING GIVING WAY TO A MOSTLY SUNNY AFTERNOON. AS FOR FOG POTENTIAL...SEE PREVIOUS EARLY MORNING PARAGRAPH FOR REASONING HERE. IN SHORT...WILL CONTINUE AT LEAST A BASIC FOG MENTION ACROSS THE ENTIRE CWA THROUGH 10 AM BUT AGAIN REALLY NOT EXPECTING ANYTHING DENSE/IMPACTFUL AT THIS TIME. AT LEAST INITIALLY...THE LOW STRATUS AND SHALLOW MIXING SHOULD KEEP MORNING SOUTHERLY WIND SPEEDS MAINLY AROUND 15 MPH OR LESS. HOWEVER...AND AGAIN ASSUMING WIDESPREAD AFTERNOON SUN BREAKS OUT AS EXPECTED...DEEPENING MIXING AND A TIGHTENING SURFACE PRESSURE GRADIENT THANKS TO PRONOUNCED HIGH PLAINS PRESSURE FALLS SHOULD LEAD TO A BREEZY/WINDY AFTERNOON WITH SUSTAINED SOUTH-SOUTHEAST SPEEDS GENERALLY 15-25 MPH AND GUSTS 25-35 MPH. TEMP-WISE...AND YET AGAIN ASSUMING PLENTIFUL AFTERNOON SUN...MADE LITTLE CHANGE TO PREVIOUS FORECAST AND KEPT TOWARD THE WARMER END OF MODEL SOLUTIONS...AIMING MOST OF THE CWA 74-77. FORTUNATELY FOR POTENTIAL FIRE WEATHER CONCERNS...EVEN MID- AFTERNOON DEWPOINTS SHOULD BE WELL INTO THE 40S...THUS KEEPING RH PERCENTAGES INTO THE 30S AND SAFELY ABOVE "NEAR-CRITICAL" LEVELS. THIS EVENING/TONIGHT: ALTHOUGH AREAS OF LOW STRATUS CLOUDS COULD AGAIN OVERTAKE MAINLY WESTERN PORTIONS OF THE CWA...THE ENTIRE AREA SHOULD SEE A GRADUAL WEST-TO-EAST INCREASE IN AT LEAST MID-HIGH LEVEL CLOUDS ALONG WITH THE AFOREMENTIONED FAIRLY LOW BUT NON-ZERO CHANCES FOR LATE NIGHT SHOWERS/WEAK THUNDERSTORMS. IN THE MID-UPPER LEVELS...NOTICEABLY STRONGER SOUTHWESTERLY FLOW WILL QUICKLY REPLACE THE CURRENT WEAK/"RIDGY" REGIME...AS THE LEADING EDGES OF FORCING ASSOCIATED WITH THE LARGE WESTERN TROUGH REACHES THE CENTRAL PLAINS. AS THIS OCCURS...FAIRLY SUBTLE SHORTWAVE TROUGHS EJECTING INTO THE PLAINS WILL INTERACT WITH A FAIRLY STOUT 50+ KT SOUTHERLY LOW-LEVEL JET EVIDENT AT 850MB TO KICK OFF AT LEAST ISOLATED SHOWERS/WEAK THUNDERSTORMS. KEPT THE PRE-06Z/EVENING HOURS PRECIP-FREE AS ANY CONVECTION SHOULD REMAIN OFF TO OUR WEST IN THE NEB PANHANDLE AND VICINITY. THEN LATE IN THE NIGHT...THE LOW CONVECTIVE CHANCES SHOULD PUSH EASTWARD INTO ALL BUT MAYBE THE FAR EASTERN ZONES. ALTHOUGH THE INITIAL SPC DAY 1 "GENERAL THUNDER" AREA ONLY CLIPS THE EXTREME WESTERN EDGE OF THE CWA...OPTED TO MAINTAIN A GENERIC "ISOLATED THUNDER" WORDING IN THE FORECAST FOR MOST OF THE CWA...AS NAM SOUNDINGS SUGGEST UP TO A FEW HUNDRED J/KG OF MOST- UNSTABLE CAPE...MAKING IT VERY HARD TO RULE OUT A FEW ROGUE LIGHTNING STRIKES. HOWEVER...THESE SHOULD BE RATHER WEAK STORMS AND EVEN PEA-SIZE HAIL MAY BE HARD TO COME BY. OTHERWISE TONIGHT...A TIGHTER PRESSURE GRADIENT COMPARED TO THIS MORNING WILL MAINTAIN STEADY SOUTH-SOUTHEAST BREEZES OF GENERALLY 15-20 MPH FOR MOST OF THE NIGHT. THESE BREEZES...IN TANDEM WITH INCREASING CLOUDS...SHOULD KEEP LOW TEMPS A FEW DEGREES WARMER THAN THIS MORNING...AND MADE LITTLE CHANGE HERE WITH A GENERAL RANGE OF 51-54. .LONG TERM...(FRIDAY DAYTIME THROUGH WEDNESDAY) ISSUED AT 455 AM CDT THU APR 14 2016 BIGGEST CHALLENGE WILL BE DETERMINING CHANCES OF RAIN. THE LONG AWAITED DEVELOPING TROUGH AND UPPER CLOSED ARRIVE IN THE GREAT BASIN/WESTERN SLOPES OF THE ROCKIES FRIDAY/FRIDAY NIGHT. ALONG WITH A STRONG UPPER RIDGE IN THE EASTERN HALF OF THE CWA. THIS RIDGE IN THE EAST WILL PUT THE BRAKES ON MUCH EASTWARD PROGRESSION OF THE TROUGH/LOW. TRENDS CONTINUALLY POINT TOWARD A SLOWED PROGRESSION EAST OF THE TROUGH...WHICH WILL TAMP DOWN ON POPS BEING VERY HIGH...BUT THEY WILL BE A HIGHER IN OUR WEST. ALSO...I SUSPECT THAT FRIDAY HAS POTENTIAL FOR BEING WARMER THAN WHAT MOST MODELS ARE ADVERTISING. I TEND TO LIKE THE WARM GUIDANCE FROM THE BIAS CORRECTED ECMWF AS THIS MODEL SEEMS TO HAVE GENERALLY OUTPERFORMED MOST NUMERICAL MODELS WHEN POTENTIAL FOR SIGNIFICANTLY WARMER THAN AVERAGE TEMPERATURES ARE EXPECTED. AND IN THIS CASE...THE SURFACE COLD FRONT SHOULD LURK WELL WEST OF THE CWA IN WESTERN NEBRASKA FOR FRIDAY...WHICH WILL LEND TO A MUCH ABOVE NORMAL DAY. IF WE HAPPEN TO GET A SOLID CIRRUS SHIELD...THEN OUR TEMPERATURES WILL BE COOLER THAN WHAT I ADVERTISE...BUT FOR NOW I SIDE WITH THE WARMER FORECAST. LIKEWISE...I WENT WARMER FOR FRIDAY NIGHT LOWS AND WENT TOWARD CONSRAW FOR LOWS AS WE REMAIN EAST OF THE COLD FRONT AND SKY COVER INCREASES QUITE A BIT. THE SAME GOES FOR SATURDAY NIGHT AND I FOLLOWED CONSRAW FOR LOWS...BUT NOT QUITE AS WARM AS FRIDAY NIGHT. SUPERBLEND SUFFICES FOR TEMPS FOR THE MOST PART BEYOND THIS. FOR POPS...I DECREASED THEM COMPARED TO WHAT SUPERBLEND IS ADVERTISING. ALSO...I AM NOT CONFIDENT ENOUGH TO GO ANY HIGHER THAN 70 POPS...EVEN IN OUR WEST AT ANY POINT. WITH THE STRONG RIDGE IN THE EAST...ALONG WITH THE WEAKENING CLOSED LOW TO THE WEST...THE CONFIDENCE IS JUST NOT THERE YET. IF THE LOW TAKES TOO LONG TO GET HERE...THE FACT THAT IT WILL PROBABLY WEAKEN WILL DECREASE OUR CHANCES OF PRECIP OVERALL. THE LOW MAY NOT EVEN MAKE IT INTO THE CENTRAL PLAINS UNTIL MID WORK WEEK. AGAIN...CONFIDENCE IS LOW...BUT THE BEST CHANCES OF RAIN REMAIN IN OUR WEST. UNTIL THE LOW CLEARS THE AREA...WE WILL HAVE CONTINUED CHANCES OF RAIN. I LEFT AT LEAST ISOLATED THUNDER IN FOR THE LONG TERM AS THERE WILL BE ENOUGH INSTABILITY FOR THIS...AND IT IS FRANKLY DIFFICULT TO NOT GET THUNDER WITH CONVECTION WHEN WE GET INTO THIS TIME OF YEAR AND BEYOND. THE SPC SWIPES OUR FAR WEST WITH MARGINAL SEVERE FOR FRIDAY...BUT I WILL HOLD OFF ON THIS AS TRENDS ARE FOR THE COLD FRONT BEING FARTHER WEST. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 121 AM CDT THU APR 14 2016 ALTHOUGH CONFIDENCE IS ACTUALLY FAIRLY HIGH THAT VFR CEILING/VISIBILITY WILL PREVAIL THROUGH THE MAJORITY OF THE PERIOD...THERE ARE SOME SERIOUS DOUBTS/QUESTIONS/UNCERTAINTIES REGARDING WHAT MIGHT TRANSPIRE MAINLY IN THE 11Z-15Z TIME FRAME THIS MORNING AS CONDITIONS COULD EASILY RANGE ANYWHERE FROM MVFR TO LIFR (MORE DETAILS BELOW) IN STRATUS AND/OR FOG. OTHERWISE...THE PERIOD SHOULD REMAIN PRECIPITATION-FREE...WITH ANY POSSIBLE SHOWER/ISOLATED THUNDERSTORM ACTIVITY HOLDING OFF UNTIL BEYOND THE CURRENT VALID PERIOD. CEILING/VISIBILITY: AS ALREADY MENTIONED...THERE ARE CONSIDERABLE UNCERTAINTIES AS TO HOW MAINLY THE 11Z-15Z TIME FRAME WILL UNFOLD...AS SOME MODELS/GUIDANCE ACTUALLY SUGGEST DENSE FOG DEVELOPMENT (WHICH SEEMS A BIT OVERDONE GIVEN STEADY SOUTH BREEZES) ALONG WITH THE POSSIBILITY OF AN IFR/LIFR CEILING. IT`S HARD TO IGNORE THE POSSIBILITY OF A LOW CEILING SURGING NORTHWARD OUT OF THE SOUTH...AS SATELLITE IMAGERY REVEALS THIS IS ALREADY OCCURRING OVER CENTRAL/SOUTHWEST KS AND WILL LIKELY EXPAND NORTHWARD. AS A RESULT...HAVE RE-INTRODUCED A LOW CEILING TO THE TAFS FOR THIS MORNING BUT KEPT IT AT IFR LEVELS (AT LEAST FOR NOW) ALONG WITH MVFR VISIBILITY IN LIGHT FOG. FORTUNATELY...ANY STRATUS/FOG IS NOT EXPECTED TO LAST MORE THAN ROUGHLY 4 HOURS AS IT MIXES OUT BY MID-MORNING WITH FAIRLY HIGH CONFIDENCE IN VFR THEREAFTER. STAY TUNED FOR PLENTY OF ADJUSTMENTS HERE... WINDS: A SOUTHERLY DIRECTION WILL PREVAIL THROUGHOUT THE PERIOD. WHILE SUSTAINED SPEEDS SHOULD LARGELY AVERAGE BELOW 12KT EARLY THIS MORNING...SPEEDS WILL STEADILY PICK UP BY LATE THURSDAY MORNING WITH GUST POTENTIAL UP TO AROUND 27KT THEN PERSISTING THROUGH THE REST OF THE PERIOD. THERE ARE HINTS THAT LOW LEVEL WIND SHEAR (LLWS) COULD APPROACH MENTIONABLE LEVELS BOTH EARLY THIS MORNING AND AGAIN LATE THURSDAY EVENING...BUT FOR NOW IT APPEARS A BIT MARGINAL TO FORMALLY INCLUDE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...HEINLEIN AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1238 AM CDT THU APR 14 2016 .UPDATE... ISSUED AT 1238AM CDT THU APR 14 2016 THE COLD FRONT EXTENDED FROM A LOW OVER CENTRAL SASKATCHEWAN SOUTH TO NEAR MINOT TO NEAR BISMARCK INTO WESTERN SOUTH DAKOTA. SCATTERED SHOWERS CONTINUED TO MOVE EAST TOWARDS THE JAMES RIVER VALLEY...JUST AHEAD OF THE COLD FRONT. ISOLATED SHOWERS NOTED ON REGIONAL RADAR MOSAICS OVER SOUTHWESTERN NORTH DAKOTA AND NORTH CENTRAL SOUTH DAKOTA. SHOWERS MOVING NORTHEASTWARD. MODELS DEPICT MAIN AREA OF SHOWERS TO CONTINUE EASTWARD INTO THE JAMES VALLEY EARLY THIS MORNING. ALSO MORE UPPER LEVEL IMPULSES IN THE SOUTHWEST FLOW ALOFT ASSOCIATED WITH THE MORE ISOLATED SHOWERS IN THE WESTERN PART OF THE STATE...INDICATING ISOLATED SHOWERS WOULD CONTINUE UNTIL AROUND DAYBREAK. MOST UNSTABLE CAPE FROM MODELS INDICATE STILL ENOUGH INSTABILITY FOR THUNDER...THUS KEPT THAT MENTION IN THE EARLY MORNING FORECAST. OTHERWISE BLENDED CURRENT TEMPERATURES TO LATEST SHORT TERM HIGH RES FORECAST. ONLY A MINOR DIFFERENCE TO MINIMUM TEMPERATURE FORECAST. UPDATE ISSUED AT 837 PM CDT WED APR 13 2016 ANOTHER UPDATE TO BLEND TO OBSERVED RADAR TRENDS THROUGH 0135 UTC AND A 9 MEMBER TIME LAGGED ENSEMBLE OF THE 22-00 UTC HRRR ITERATIONS WHICH CONTINUE TO HAVE A GOOD HANDLE ON THE AREA OF RAIN SHOWERS WITH A FEW WEAK EMBEDDED THUNDERSTORMS AHEAD OF THE SURFACE COLD FRONT. UPDATE ISSUED AT 529 PM CDT WED APR 13 2016 QUICK UPDATE TO BLEND TO OBSERVED RADAR TRENDS THROUGH 2215 UTC AND A TIME LAGGED ENSEMBLE OF THE 19-21 UTC HRRR ITERATIONS WHICH HAS A GOOD HANDLE ON THE ON GOING CONVECTION. WIND GUSTS OF 45 TO 50 MPH ARE POSSIBLE WITH THESE STORMS GIVEN INVERTED V SOUNDINGS. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 348 PM CDT WED APR 13 2016 THE LATEST WATER VAPOR IMAGERY SHOWS A DEEP CLOSED LOW APPROACHING THE PACIFIC NORTHWEST. THIS CLOSED LOW WILL SLOWLY SHIFT SOUTHEAST INTO THE GREAT BASIN AND FOUR CORNERS NOW THROUGH SUNDAY. IN DOING SO...A FAVORABLE SOUTHWEST FLOW INTO NORTH DAKOTA WITH A SERIES OF SURFACE LOW PRESSURES AND ASSOCIATED SHORTWAVES PEELING OFF/EJECTING FROM THE MAIN UPPER LOW MENTIONED ABOVE...WILL TRACK ACROSS SOUTHERN AND EASTERN NORTH DAKOTA. APPROXIMATELY THREE SURFACE LOWS AND ASSOCIATED SHORTWAVES WILL PASS ACROSS WESTERN AND CENTRAL NORTH DAKOTA BETWEEN WEDNESDAY NIGHT AND SUNDAY. THIS WILL RESULT IN A WET/UNSETTLED PERIOD THROUGH THE WEEKEND. HIGHLIGHT IN THE NEAR TERM (NOW THROUGH WEDNESDAY AFTERNOON) IS THE ONGOING RED FLAG WARNING. VERIFICATION IS UNDERWAY WITH FORECAST AND OBSERVATIONAL DATA SHOWING SUSTAINED WINDS BETWEEN 20 MPH AND 25 MPH ...WITH RELATIVE HUMDITIES BETWEEN 20 AND 25 PERCENT AT THIS TIME. ONE CONCERN IN THE WEST IS INCREASING HIGH/MIDDLE CLOUDS COMING IN FROM EASTERN MONTANA. THIS COULD/MAY DISRUPT THE THREE CONSECUTIVE HOUR VERIFICATION IN SOME SPOTS...AS ADDITIONAL CLOUDS/SHADING MIGHT BE ENOUGH TO HALT OR LIMIT SOLAR INSOLATION AND MIXING NEEDED TO SUSTAIN THE WIND/LOW HUMIDITIES FOR THE TIME NEEDED. HOWEVER WILL KEEP THE WARNING IN TACT UNTIL THIS BECOMES EVIDENT. ALSO MONITORING AREAS JUST EAST OF THE CURRENT RED FLAG WARNING. BELIEVE THIS WILL BE A MARGINAL AREA...BOTH IN TIME AND AREAL COVERAGE INTO THE LATE AFTERNOON...AND THUS WILL HOLD OFF FROM EXPANDING THE CURRENT RED FLAG WARNING AT THIS TIME. FOR THE SHORT TERM PERIOD...TONIGHT THROUGH THURSDAY...FOCUS WILL BE THE PASSAGE OF A COLD FRONT TONIGHT...RESULTING IN A PERIOD OF RAIN SHOWERS AND SOME THUNDERSTORMS. A SURFACE LOW PRESSURE IN WESTERN SOUTH DAKOTA WILL RIDE UP ALONG THE COLD FRONT OVERNIGHT REACHING THE SOUTHERN JAMES RIVER VALLEY BY 12Z THURSDAY AND THEN STALLING OUT DURING THE DAY. THUNDERSTORMS ARE NOT EXPECTED TO REACH SEVERE CRITERIA TONIGHT. BUT EXPECT SOME SHOWERS AND RUMBLING OVERNIGHT ALONG AND AHEAD OF THE COLD FRONT. WITH THE FRONT STALLING OUT THURSDAY IN THE JAMES RIVER VALLEY...CHANCES OF SHOWERS WILL CONTINUE HERE WITH A BREAK/DRY PERIOD ELSEWHERE FOR MOST OF THE AFTERNOON. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 348 PM CDT WED APR 13 2016 HIGHLIGHTS IN THE LONG TERM INCLUDE PERIODS OF RAINSHOWERS AND THUNDERSTORMS WITH WIDESPREAD RAINFALL OF BETWEEN THUNDERSTORMS. RAINFALL TOTALS BETWEEN A HALF INCH TO ONE AND A HALF INCHES LOOKS TO BE A GOOD RANGE ACROSS WESTERN AND CENTRAL NORTH DAKOTA WEDNESDAY NIGHT THROUGH SUNDAY. THURSDAY NIGHT...THE BRIEF BREAK MENTIONED ABOVE WILL COME TO AN END LATE THURSDAY AFTERNOON/EVENING...AS THE NEXT STRONGER SURFACE LOW FOLLOW A NEARLY IDENTICAL PATH...ALBEIT SLOWER. THIS WILL RESULT IN WIDESPREAD RAIN SHOWERS AND SCATTERED THUNDERSTORMS THURSDAY NIGHT THROUGH FRIDAY. ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THURSDAY EVENING/NIGHT AS STRONGER INSTABILITY WILL EXIST WITH THIS NEXT SURFACE LOW AND ASSOCIATED SHORTWAVE TROUGH ALOFT. THUNDERSTORMS ARE FORECAST TO INITIATE IN EASTERN MONTANA LATE THURSDAY AFTERNOON INTO THE EARLY EVENING...THEN SHIFT INTO SOUTHWESTERN NORTH DAKOTA. ANY SURFACED BASE CONVECTION WILL LIKELY TRANSITION TO ELEVATED CONVECTION ACROSS SOUTH CENTRAL AND INTO THE JAMES RIVER VALLEY 06Z-12Z FRIDAY. FRIDAY THROUGH SUNDAY...A WET DAY FRIDAY AS THE AFOREMENTIONED SURFACE LOW RIDES UP ALONG A COLD FRONT ACROSS SOUTH CENTRAL AND INTO THE JAMES RIVER VALLEY. SHOWERS AND SCATTERED THUNDERSTORMS MOSTLY ACROSS CENTRAL NORTH DAKOTA WHICH WILL BE LOCATED NEAREST THE COLD FRONT AND SURFACE LOW. LESS SHOWER ACTIVITY IS FORECAST IN THE WEST. ANOTHER SURFACE IS FORECAST TO PASS ACROSS NORTHEAST SOUTH DAKOTA AND INTO MINNESOTA SATURDAY NIGHT AND SUNDAY RESULTING IN A CHANCE OF SHOWERS MAINLY FAR SOUTH CENTRAL INTO THE JAMES RIVER VALLEY...WITH DRIER CONDITIONS FARTHER WEST AND NORTH. MONDAY THROUGH WEDNESDAY...AS THE CLOSED UPPER LOW WILL SIT AND SPIN ACROSS THE FOUR CORNERS MONDAY THEN BECOME AN OPEN WAVE TUESDAY AND WEDNESDAY BUT REMAIN SOUTH OF NORTH DAKOTA. A REX BLOCK FORMATION DEVELOPS WITH AN UPPER HIGH SITUATED OVER THE UPPER LOW MENTIONED ABOVE. THIS IS FORECAST TO PRODUCE A DRY PERIOD WITH MODERATING TEMPERATURES THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1238 AM CDT THU APR 14 2016 AT MIDNIGHT CDT...A COLD FRONT IN CENTRAL NORTH DAKOTA WAS MOVING EAST. SCATTERED SHOWERS ALONG THE FRONTAL BOUNDARY WERE MOVING EAST AS WELL. THE SHOWERS WILL MOVE OUT OF THE REGION BY SUNRISE THURSDAY. DEVELOPING LOW PRESSURE IN SOUTHEAST MONTANA WILL BRING THE NEXT ROUND OF SHOWERS TO WESTERN NORTH DAKOTA AFTER 00Z. EXPECT VFR CONDITIONS AT ALL TAF SITES. && .FIRE WEATHER... ISSUED AT 1238 AM CDT THU APR 14 2016 RED FLAG WARNING EXPIRED AT 7 PM CDT OR 6 PM MDT ON WEDNESDAY EVENING. PREVIOUS DISCUSSION FROM 348 PM CDT WEDNESDAY: A RED FLAG WARNING CONTINUES THIS AFTERNOON AND EARLY EVENING OVER THE WESTERN THIRD OF NORTH DAKOTA. THE COMBINATION OF SUSTAINED SOUTHERLY WINDS OF 25 MPH...MINIMUM RELATIVE HUMIDITY AROUND 20 PERCENT AND MAXIMUM TEMPERATURES IN THE MIDDLE 70S WILL CREATE THE CRITICAL FIRE WEATHER CONDITIONS. WINDS WILL ALSO SHIFT TO THE WEST LATE THIS AFTERNOON INTO EARLY EVENING AS A COLD FRONT APPROACHES AND SHIFTS THROUGH. DRY LIGHTNING REMAINS A POSSIBILITY EARLY THIS EVENING. INCREASING MOISTURE AND THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BEGIN WEDNESDAY EVENING AND CONTINUE THROUGH THURSDAY AND FRIDAY. COOLER TEMPERATURES ARE EXPECTED SATURDAY AS THE PRECIPITATION ENDS WITH A MIX OF RAIN AND SNOW ACROSS THE NORTH. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...KS LONG TERM...KS AVIATION...WAA FIRE WEATHER...KS Area Forecast Discussion National Weather Service Spokane WA 257 AM PDT THU APR 14 2016 .SYNOPSIS... A low pressure system will bring widespread rain and high mountain snow to the Inland Northwest today. Scattered mountain showers will linger over the Idaho Panhandle on Friday. Dry and much warmer weather will return to the Pacific Northwest this weekend and persist into the middle of next week. Afternoon temperatures in the mid 70s to low 80s Sunday through Tuesday will accelerate mountain snow melt and produce rises on many area rivers. && .DISCUSSION... Today through Friday...A well defined low off the northern Oregon coast this morning will send a moist occluded front across the region from southwest to northeast this morning. This will result in widespread rain and mountain snow over the area with most locations picking up between a tenth to a quarter inch of rain. Elevations above 4000 to 5000 feet could pick up a couple inches of snow resulting in local travel impacts over the mountain passes...including Stevens, Loup Loup, Sherman, and Lookout Pass. This area of precipitation will stall near or just north of the Canadian border this afternoon but showers will develop behind this especially over the mountains with a cold pool aloft over the area. The models indicate enough instability across the Chelan, Wenatchee, and Waterville areas as well as the Blue Mountains and Camas Prairie to warrant a slight chance of afternoon and early evening thunderstorms with CAPE values of 200-500 J/KG. As the low pulls away tonight drier air aloft will nose into Central and Eastern Washington while showers linger over the Idaho Panhandle. A short wave ridge moves over the region on Friday. However lingering low level moisture and afternoon heating may trigger a few showers over the mountains. Models even indicate CAPE values around 200 J/KG but with a short wave ridge over the area it is unlikely that any thunderstorms will develop. JW Saturday through Monday: Strong high pressure will develop over the western United States over the weekend and persist into early next week. Temperatures on Saturday will climb above average with afternoon readings reaching the 60s and low 70s. By Sunday and Monday, the 500mb ridge over the Western U.S. will become 2 to 3 standard deviations above normal as heights over eastern Washington and north Idaho reach 580dm plus. Afternoon temperatures will surge into the 70s on Sunday and several of our typical warm spots like Lewiston, Moses Lake, and Wenatchee will have a good shot of eclipsing 80 on Monday. Keep in mind our typical highs this time of year are in the mid 50s and low 60s. Increased run-off from mountain snow melt will begin to produce rises in basins with ample high elevation snow pack. In general, our basins fed by the Cascades and Canadian Rockies have the most snow remaining (above 5000ft). The Moyie, Kootenai, Okanogan, Similkameen, and Stehekin Rivers will experience the most significant rises over the weekend into next week. Tuesday and Wednesday: Tuesday and Wednesday we will begin to look for the break down of the ridge. There is decent agreement between the GFS and ECMWF that a shortwave approaching from the southwest in the Tuesday/Wednesday time frame will dent our big ridge. Our air mass will be warm enough that the atmosphere may behave like summer. Steep lapse rates and surface based instability could bring our region a shot thunderstorms Wednesday or Thursday. /GKoch && .AVIATION... 06Z TAFS: Low pressure system moves ashore tonight and tracks along the WA/OR border between 12Z and 23Z Thur. Light showers ahead of the system will mainly impact SE WA and N-C Idaho through 10z then an area of wrap-around stratiform rain will migrate north into all terminals 11-14Z resulting in the potential for MVFR ceilings. Timing carries some uncertainty wit models trending slower this evening. The steady band of rain will crawl into northern WA/ID Thur aftn however as steady rain ends, scattered showers will be possible, especially with breaks in the clouds. The system will begin drifting south after 00z and pull the remnants of the moisture and threat for showers back south through the region thus showers or vcsh were kept in the forecast after sunset and through 06z. Moderate uncertainty exists with particular ceiling heights. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 52 37 58 38 64 42 / 100 30 10 10 0 0 Coeur d`Alene 50 36 57 37 64 40 / 100 30 20 10 0 0 Pullman 52 35 56 36 62 39 / 80 30 10 10 0 0 Lewiston 57 39 62 40 68 43 / 90 30 10 10 0 0 Colville 52 36 63 36 67 38 / 100 30 10 10 0 0 Sandpoint 48 37 56 35 62 36 / 100 60 20 10 0 0 Kellogg 47 34 52 35 62 37 / 100 40 30 10 0 0 Moses Lake 59 37 65 38 70 41 / 60 20 10 0 0 0 Wenatchee 55 41 64 42 69 45 / 80 20 10 0 0 0 Omak 53 38 64 39 67 42 / 100 30 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...Winter Weather Advisory until 1 PM PDT this afternoon for East Slopes Northern Cascades. && $$
Area Forecast Discussion National Weather Service Spokane WA 1154 PM PDT WED APR 13 2016 .SYNOPSIS... Rain and mountain snow will increase across the region overnight into Thursday including the Columbia Basin and our typically dry portions of central Washington. Warm and dry weather will return to the Pacific Northwest this weekend. By early next week, afternoon temperatures will have the potential to be in the upper 70s and lower 80s. && .DISCUSSION... The latest 00z ECMWF and HRRR runs are catching up to the current situation with precip slower to move into the region. Thus far mid level instability is triggered scattered showers over southeast Washington and the south Idaho Panhandle, with stratiform rain associated with the incoming low over north Central Oregon. This area of stratiform rain is expected to reach central and southeast Washington and Lewiston area overnight before lifting north Thursday morning. Thus POP`s have been adjusted to reflect this. JW && .AVIATION... 06Z TAFS: Low pressure system moves ashore tonight and tracks along the WA/OR border between 12Z and 23Z Thur. Light showers ahead of the system will mainly impact SE WA and N-C Idaho through 10z then an area of wrap-around stratiform rain will migrate north into all terminals 11-14Z resulting in the potential for MVFR ceilings. Timing carries some uncertainty wit models trending slower this evening. The steady band of rain will crawl into northern WA/ID Thur aftn however as steady rain ends, scattered showers will be possible, especially with breaks in the clouds. The system will begin drifting south after 00z and pull the remnants of the moisture and threat for showers back south through the region thus showers or vcsh were kept in the forecast after sunset and through 06z. Moderate uncertainty exists with particular ceiling heights. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 42 52 37 58 38 64 / 30 100 30 20 10 0 Coeur d`Alene 40 52 36 57 37 64 / 40 100 30 30 10 0 Pullman 40 52 35 55 36 64 / 70 80 30 30 10 0 Lewiston 46 58 39 60 39 68 / 70 90 30 20 10 0 Colville 39 54 36 63 37 68 / 20 100 30 20 10 0 Sandpoint 37 49 37 56 36 63 / 20 100 60 30 10 0 Kellogg 36 47 34 52 35 62 / 70 90 40 50 10 10 Moses Lake 46 59 37 65 39 69 / 40 60 20 10 0 0 Wenatchee 45 58 41 64 42 69 / 60 80 20 0 0 0 Omak 43 58 38 64 38 67 / 20 100 30 10 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...Winter Weather Advisory from 5 AM to 1 PM PDT Thursday for East Slopes Northern Cascades. && $$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
918 PM PDT WED APR 13 2016 .SYNOPSIS...AN UPPER TROUGH WILL MOVE SLOWLY EAST ACROSS THE REGION TONIGHT AND THURSDAY...BRINGING SHOWERY WEATHER TO WESTERN WASHINGTON. LIGHT SHOWERS COULD LINGER FRIDAY...THEN AN UPPER RIDGE WILL BUILD OVER THE REGION FOR SUNNIER WARMER WEATHER SATURDAY THROUGH MONDAY. THERE IS A CHANCE OF SHOWERS AGAIN BY TUESDAY. && .SHORT TERM...A VERTICALLY STACKED AND FILLING 993 MB SURFACE LOW WAS LOCATED NEAR 47N 132W THIS EVENING...OR WELL OFF THE SOUTH WA COAST. THE LOW WILL CONTINUE TO WEAKEN TO ABOUT 1000 MB BY THE TIME IT CROSSES THE FAR NRN ORE COAST ON THU MORNING...WITH CONTINUED WEAKENING AS IT TRACKS INTO INTO THE COLUMBIA BASIN ON THU AFTN. LARGE-SCALE LIFT WILL CONTINUE UNTIL THE LOW PASSES EAST OF OUR LONGITUDE...SO SHOWER ACTIVITY WILL CONTINUE OVER SW WA THIS EVNG...THEN SPREAD NE THROUGH THE PUGET SOUND REGION OVERNIGHT. LATEST HI-RES MODELS SHOW SOME WRAP-AROUND PRECIP OR A DEFORMATION ZONE OVER THE CASCADES FROM SNOQUALMIE PASS ON NORTH ON THU MORNING. THE 02Z HRRR DUMPS NEARLY ONE INCH OF LIQUID EQUIVALENT AT STEVENS PASS THU MORNING...WITH SNOW LEVELS NEAR OR JUST BELOW PASS LEVEL. WILL SOON DO A FORECAST UPDATE TO INCREASE SNOW AMOUNTS THERE IN THE MORNING. MAY NEED A WINTER WEATHER ADVISORY. AFTER THE LOW CENTER PASSES EAST LATER THU...LARGER SCALE LIFT WILL END...BUT COOL AIR ALOFT WILL STILL LEAD TO A FEW SHOWERS...ESPECIALLY OVER THE MTNS AND SW INTERIOR. UPPER HEIGHTS WILL RISE STRONGLY ON THU NGT AND FRI...WITH JUST A COUPLE OF SHALLOW AND WEAK SHOWERS OVER THE MTNS ON FRI. THE TAIL END OF A WARM FRONT MAY BRUSH THE NW OLYMPIC PENINSULA WITH A LITTLE LIGHT RAIN SAT MORNING. UPPER HEIGHTS WILL THEN RISE FURTHER...AND THE ENTIRE VERTICAL DEPTH OF THE ATMOSPHERE WILL DRY OUT. LOW-LEVEL OFFSHORE FLOW WILL CRANK UP ON SAT NGT. THEREFORE...A SOLID CLEARING...DRYING AND WARMING TREND ON SAT AFTN. HANER .LONG TERM...FROM PREVIOUS DISCUSSION...IT LOOKS INCREASINGLY LIKELY THAT THE UPPER RIDGE WILL BUILD THROUGH MONDAY...KEEPING WESTERN WASHINGTON DRY AND WARMER WITH SOUTHERLY FLOW ALOFT. THAT HAS BEEN THE TREND IN THE MODELS OVER THE PAST FEW DAYS. HIGHS SHOULD BE IN THE 70S OVER MOST OF THE WESTERN WASHINGTON LOWLANDS SUNDAY AND MONDAY WITH MOSTLY SUNNY SKIES. THE MODELS ARE ALSO IN ROUGH AGREEMENT THAT A CLOSED UPPER LOW WEST OF CALIFORNIA ON MONDAY WILL BRING A CHANCE OF SHOWERS TO WESTERN WASHINGTON BEGINNING MONDAY NIGHT OR TUESDAY AND CONTINUING THROUGH WEDNESDAY...AS IT EJECTS NORTHEAST ACROSS THE REGION. MCDONNAL && .AVIATION...AN UPPER LOW AND AN ASSOCIATED OCCLUDED FRONT WILL PUSH ONSHORE TONIGHT AND THURSDAY. THE STRONGEST PART OF THE WEATHER SYSTEM WILL MOVE INLAND TO THE SOUTH. SOUTHERLY FLOW ALOFT WILL BECOME NORTHERLY LATE THURSDAY. THE AIR MASS IS SOMEWHAT MOIST AND SLIGHTLY UNSTABLE. THERE IS A MIX OF LOW AND MID LEVEL MOISTURE BUT CEILINGS WILL PROBABLY GENERALLY REMAIN VFR. LOWER CEILINGS ARE POSSIBLE LATER TONIGHT...ESPECIALLY COAST AND SOUTH PART WHERE PRECIPITATION WILL BE MORE WIDESPREAD. KSEA...THERE SHOULD BE A MIX OF LOW AND MID CLOUDS TONIGHT...WITH LOW CLOUDS BECOMING MORE LIKELY AFTER MIDNIGHT AS RAIN BECOMES MORE WIDESPREAD. SOME DRYING IS LIKELY LATER THURSDAY AND THURSDAY NIGHT AS AN UPPER MOVES OUT OF THE AREA AND MORE STABLE AIR MOVES IN. WINDS WILL BE VARIABLE 4-8 KNOTS...BECOMING NORTHWEST THURSDAY AFTERNOON. SCHNEIDER && .MARINE...AN OCCLUDED FRONTAL SYSTEM WILL MOVE ONSHORE TONIGHT. AN ASSOCIATED FILLING 999 MB SURFACE LOW WILL MOVE ONSHORE OVER SOUTHWEST WASHINGTON OR NORTHWEST OREGON THURSDAY MORNING. GALES ARE FORECAST FOR THE COASTAL WATERS THIS EVENING AS THE FRONT MOVES ONSHORE BUT IT IS LOOKING LIKE THEY WONT MATERIALIZE. SMALL CRAFT ADVISORY WINDS FOR OTHER WATERS WILL ALSO COME DOWN TONIGHT. THE ONLY REMAINING HAZARDS BY THURSDAY WILL BE SOME RESIDUAL 12-15 FOOT WEST SWELL FOR THE COASTAL WATERS. ONSHORE GRADIENTS RISE IN THE AFTERNOON WHICH SHOULD GIVE SMALL CRAFT WEST WINDS TO THE CENTRAL AND EAST STRAIT THURSDAY EVENING. WEAK HIGH PRESSURE WILL MOVE OVER THE AREA FRIDAY AND REMAIN IN PLACE SATURDAY. OFFSHORE FLOW WILL DEVELOP SUNDAY WITH A THERMAL TROUGH ALONG THE COAST TO THE SOUTH AND HIGHER PRESSURE INLAND. SCHNEIDER && .SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. PZ...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM PDT THURSDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. GALE WARNING UNTIL MIDNIGHT PDT TONIGHT FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM- COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 5 PM PDT THURSDAY FOR GRAYS HARBOR BAR. SMALL CRAFT ADVISORY UNTIL 5 AM PDT THURSDAY FOR ADMIRALTY INLET- EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. && $$ WWW.WEATHER.GOV/SEATTLE YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
ISSUED BY NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 845 AM PDT THU APR 14 2016 .SYNOPSIS....DRY WEATHER CONDITIONS WILL RETURN TO MOST AREAS BY LATE MORNING AND THEN CONTINUE THROUGH THE WEEKEND...ALONG WITH A SIGNIFICANT WARMING TREND. COOLING IS THEN EXPECTED MONDAY AND TUESDAY OF NEXT WEEK AS AN UPPER TROUGH APPROACHES THE WEST COAST. && .DISCUSSION...AS OF 08:44 AM PDT THURSDAY...REMNANTS OF A COLD FRONT WILL EXIT THE SOUTHERN PORTION OF THE AREA THIS MORNING. RAINFALL AMOUNTS 0.10 INCH OR LESS EXTENDED FROM THE SOUTH BAY TO THE SOUTHERN MONTEREY COUNTY LINE IN THE PAST THREE HOURS AND ISOLATED LIGHT AMOUNTS MAY DEVELOP OVER THE NORTH HALF OF THE AREA THIS AFTERNOON. THERE IS RELATIVELY STRONG DESENDING AIR WITHIN INCREASING NORTHWEST WINDS TODAY AND BRIEF SHOWERS DEVELOOP OVER THE HIGHER TERRAIN. NO UPDATE ANTICIPATED AT THIS TIME. && .PREV DISCUSSION...AS OF 4:05 AM PDT THURSDAY...SATELLITE IMAGERY SHOWS THE PRIMARY COLD FRONTAL CLOUD BAND PUSHING THROUGH THE MIDDLE OF OUR DISTRICT WHILE LATEST KMUX RADAR DATA SHOW AREAS OF SHOWERS EXTENDING FROM THE CENTRAL SF BAY AREA SOUTH THROUGH THE SANTA CRUZ MOUNTAINS. THE HIGHEST RAINFALL TOTAL NOTED THUS FAR IS 0.69 INCHES AT THE MIDDLE PEAK (MT TAMALPAIS) RAWS SITE IN MARIN COUNTY...WITH MOST LOWER ELEVATION LOCATIONS AROUND THE BAY HAVING RECEIVED LESS THAN TWO TENTHS OF AN INCH. LATEST HRRR AND NAM MODEL OUTPUT REMAIN IN GOOD AGREEMENT IN WEAKENING AND THEN DISSIPATING THE FRONT AS IT MOVES SOUTHWARD THROUGH MONTEREY COUNTY DURING THE FIRST PART OF THE MORNING. BY LATE MORNING DRY CONDITIONS ARE EXPECTED TO GENERALLY PREVAIL ACROSS THE CWA...WITH JUST A CHANCE OF A FEW LINGERING POST- FRONTAL LIGHT SHOWERS...PRIMARILY OVER NORTHERN SONOMA COUNTY. THE AIRMASS BEHIND THE FRONT WILL BE QUITE COOL...WITH 850 MB TEMPS FORECAST TO DROP AS LOW AS ZERO TO ONE DEG C IN THE NORTH BAY BY LATER THIS MORNING. BUT MID-APRIL DIURNAL HEATING WILL PARTIALLY COMPENSATE WITH THE NET RESULT OF LOWER ELEVATION MAX TEMPS AROUND THE BAYS STILL MOSTLY REACHING UP INTO THE LOWER TO MID 60S. IT WILL BE A BIT BRISK NEAR THE COAST THOUGH...AS NORTHWEST WINDS PICK UP THERE DURING THE AFTERNOON HOURS. THEN ON FRIDAY...MODELS REMAIN IN EXCELLENT AGREEMENT IN RAPIDLY BUILDING A STRONG UPPER LEVEL RIDGE NORTHEASTWARD INTO THE WEST COAST...AND SURFACE HIGH PRESSURE INTO THE PACIFIC NORTHWEST AND NORTHERN GREAT BASIN. SUNNY CONDITIONS ARE EXPECTED TO PREVAIL DISTRICTWIDE...AND IN COMBINATION WITH AIR MASS WARMING AND PROGRESSIVELY DRIER AND MORE OFFSHORE ORIENTED FLOW RESULT IN THE BEGINNING OF A SIGNIFICANT WARMING TREND. AFTERNOON HIGHS ON FRIDAY WILL GENERALLY BE 4 TO 7 DEG WARMER THAN THOSE TODAY...BUT LOCALLY UP TO 10-12 DEGREES WARMER IN NORTH BAY VALLEY LOCATIONS SUCH AS THE SANTA ROSA AREA WHERE DOWNSLOPE WARMING EFFECTS ARE MAXIMIZED. OVER THE WEEKEND...THE WARMING TREND WILL CONTINUE. BASED ON LATEST MODEL OUTPUT AND ASSOCIATED MOS GUIDANCE...ESPECIALLY FROM THE ECMWF WHICH TENDS TO DO WELL IN SUCH SITUATIONS...HAVE BUMPED UP AFTERNOON HIGHS BOTH SATURDAY AND SUNDAY FROM INHERITED GRIDS AND FORECASTS. CURRENT THINKING IS THAT WILL SEE WIDESPREAD MID 70S TO LOWER 80S ON SATURDAY...AND THEN 80S ACROSS MUCH OF THE DISTRICT ON SUNDAY WITH WARMEST INLAND LOCATIONS BRUSHING UPWARDS TOWARDS 90 DEG. IN THE EXTENDED...THE UPPER LEVEL RIDGE AXIS IS FORECAST TO BEGIN SHIFTING EASTWARD ALONG WITH A RETURN TO MORE ONSHORE ORIENTED SURFACE FLOW. THE NET RESULT WILL BE A SIGNIFICANT COOLING TREND WORKING ITS WAY INLAND MONDAY AND TUESDAY. LONGER RANGE MODELS DO GENERALLY AGREE THAT THE TAIL END OF AN UPPER LEVEL TROUGH WILL APPROACH OUR COAST IN THE TUESDAY TO TUESDAY NIGHT TIME FRAME...BUT RAIN CHANCES PRESENTLY APPEAR MINIMAL AS GENERAL CONSENSUS THAT IT WILL THEN WEAKEN AND LIFT QUICKLY TO THE NORTH- NORTHEAST BEFORE MOVING ONSHORE. && .AVIATION...AS OF 5:13 AM PDT THURSDAY...A COLD FRONT WAS MOVING RAPIDLY SE OVER THE SOUTH BAY AREA AND WILL BE OVER THE NORTH CENTRAL COAST MID-LATE MORNING. SHOWERS CONTINUE TO ACCOMPANY THE COLD FRONT. W-NW WINDS WILL BECOME GUSTY TODAY. VICINITY OF KSFO...VFR CONDITIONS WITH GUSTY WEST WINDS TODAY. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...MVFR/VFR. SHOWERS THIS MORNING. GUSTY W-NW WINDS TODAY. && .MARINE...AS OF 08:44 AM PDT THURSDAY...WINDS WILL BECOME NORTHWESTERLY AND INCREASE AND SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY TODAY THROUGH SATURDAY MORNING. NORTHWESTERLY SWELLS WILL BUILD OVER 10 FEET TODAY AND TONIGHT THEN SUBSIDE LATER FRIDAY INTO THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...HIGH SURF ADVISORY...CAZ006-505-509 HIGH SURF ADVISORY...CAZ529-530 SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 3 PM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 11 AM SCA...PT ARENA TO PT REYES 0-10 NM FROM 11 AM SCA...PT REYES TO PIGEON PT 0-10 NM FROM 3 PM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...MRY BAY FROM 11 AM && $$ PUBLIC FORECAST: 30/BLIER AVIATION: 30 MARINE: 30 VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
513 AM PDT THU APR 14 2016 .SYNOPSIS....SHOWER CHANCES WILL DIMINISH DURING THE MORNING HOURS AS THE WEAK COLD FRONT NOW MOVING THROUGH OUR DISTRICT DISSIPATES. DRY WEATHER CONDITIONS WILL RETURN TO MOST AREAS BY LATE MORNING THURSDAY AND THEN CONTINUE THROUGH THE WEEKEND...ALONG WITH A SIGNIFICANT WARMING TREND. COOLING IS THEN EXPECTED MONDAY AND TUESDAY OF NEXT WEEK AS AN UPPER TROUGH APPROACHES THE WEST COAST. && .DISCUSSION...AS OF 4:05 AM PDT THURSDAY...SATELLITE IMAGERY SHOWS THE PRIMARY COLD FRONTAL CLOUD BAND PUSHING THROUGH THE MIDDLE OF OUR DISTRICT WHILE LATEST KMUX RADAR DATA SHOW AREAS OF SHOWERS EXTENDING FROM THE CENTRAL SF BAY AREA SOUTH THROUGH THE SANTA CRUZ MOUNTAINS. THE HIGHEST RAINFALL TOTAL NOTED THUS FAR IS 0.69 INCHES AT THE MIDDLE PEAK (MT TAMALPAIS) RAWS SITE IN MARIN COUNTY...WITH MOST LOWER ELEVATION LOCATIONS AROUND THE BAY HAVING RECEIVED LESS THAN TWO TENTHS OF AN INCH. LATEST HRRR AND NAM MODEL OUTPUT REMAIN IN GOOD AGREEMENT IN WEAKENING AND THEN DISSIPATING THE FRONT AS IT MOVES SOUTHWARD THROUGH MONTEREY COUNTY DURING THE FIRST PART OF THE MORNING. BY LATE MORNING DRY CONDITIONS ARE EXPECTED TO GENERALLY PREVAIL ACROSS THE CWA...WITH JUST A CHANCE OF A FEW LINGERING POST- FRONTAL LIGHT SHOWERS...PRIMARILY OVER NORTHERN SONOMA COUNTY. THE AIRMASS BEHIND THE FRONT WILL BE QUITE COOL...WITH 850 MB TEMPS FORECAST TO DROP AS LOW AS ZERO TO ONE DEG C IN THE NORTH BAY BY LATER THIS MORNING. BUT MID-APRIL DIURNAL HEATING WILL PARTIALLY COMPENSATE WITH THE NET RESULT OF LOWER ELEVATION MAX TEMPS AROUND THE BAYS STILL MOSTLY REACHING UP INTO THE LOWER TO MID 60S. IT WILL BE A BIT BRISK NEAR THE COAST THOUGH...AS NORTHWEST WINDS PICK UP THERE DURING THE AFTERNOON HOURS. THEN ON FRIDAY...MODELS REMAIN IN EXCELLENT AGREEMENT IN RAPIDLY BUILDING A STRONG UPPER LEVEL RIDGE NORTHEASTWARD INTO THE WEST COAST...AND SURFACE HIGH PRESSURE INTO THE PACIFIC NORTHWEST AND NORTHERN GREAT BASIN. SUNNY CONDITIONS ARE EXPECTED TO PREVAIL DISTRICTWIDE...AND IN COMBINATION WITH AIR MASS WARMING AND PROGRESSIVELY DRIER AND MORE OFFSHORE ORIENTED FLOW RESULT IN THE BEGINNING OF A SIGNIFICANT WARMING TREND. AFTERNOON HIGHS ON FRIDAY WILL GENERALLY BE 4 TO 7 DEG WARMER THAN THOSE TODAY...BUT LOCALLY UP TO 10-12 DEGREES WARMER IN NORTH BAY VALLEY LOCATIONS SUCH AS THE SANTA ROSA AREA WHERE DOWNSLOPE WARMING EFFECTS ARE MAXIMIZED. OVER THE WEEKEND...THE WARMING TREND WILL CONTINUE. BASED ON LATEST MODEL OUTPUT AND ASSOCIATED MOS GUIDANCE...ESPECIALLY FROM THE ECMWF WHICH TENDS TO DO WELL IN SUCH SITUATIONS...HAVE BUMPED UP AFTERNOON HIGHS BOTH SATURDAY AND SUNDAY FROM INHERITED GRIDS AND FORECASTS. CURRENT THINKING IS THAT WILL SEE WIDESPREAD MID 70S TO LOWER 80S ON SATURDAY...AND THEN 80S ACROSS MUCH OF THE DISTRICT ON SUNDAY WITH WARMEST INLAND LOCATIONS BRUSHING UPWARDS TOWARDS 90 DEG. IN THE EXTENDED...THE UPPER LEVEL RIDGE AXIS IS FORECAST TO BEGIN SHIFTING EASTWARD ALONG WITH A RETURN TO MORE ONSHORE ORIENTED SURFACE FLOW. THE NET RESULT WILL BE A SIGNIFICANT COOLING TREND WORKING ITS WAY INLAND MONDAY AND TUESDAY. LONGER RANGE MODELS DO GENERALLY AGREE THAT THE TAIL END OF AN UPPER LEVEL TROUGH WILL APPROACH OUR COAST IN THE TUESDAY TO TUESDAY NIGHT TIME FRAME...BUT RAIN CHANCES PRESENTLY APPEAR MINIMAL AS GENERAL CONSENSUS THAT IT WILL THEN WEAKEN AND LIFT QUICKLY TO THE NORTH- NORTHEAST BEFORE MOVING ONSHORE. && .AVIATION...AS OF 5:13 AM PDT THURSDAY...A COLD FRONT WAS MOVING RAPIDLY SE OVER THE SOUTH BAY AREA AND WILL BE OVER THE NORTH CENTRAL COAST MID-LATE MORNING. SHOWERS CONTINUE TO ACCOMPANY THE COLD FRONT. W-NW WINDS WILL BECOME GUSTY TODAY. VICINITY OF KSFO...VFR CONDITIONS WITH GUSTY WEST WINDS TODAY. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...MVFR/VFR. SHOWERS THIS MORNING. GUSTY W-NW WINDS TODAY. && .MARINE...AS OF 4:06 AM PDT THURSDAY...A COLD FRONT WILL CONTINUE TO MOVE RAPIDLY SOUTHEAST THIS MORNING. WINDS WILL BECOME NORTHWESTERLY TODAY. NORTHWESTERLY SWELLS WILL BUILD TODAY AND TONIGHT THEN SUBSIDE LATER FRIDAY INTO THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY SOUTH TO MONTEREY COUNTY SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 3 PM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 11 AM SCA...PT ARENA TO PT REYES 0-10 NM FROM 11 AM SCA...PT REYES TO PIGEON PT 0-10 NM FROM 3 PM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...MRY BAY FROM 11 AM && $$ PUBLIC FORECAST: BLIER AVIATION/MARINE: CANEPA VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
426 AM PDT THU APR 14 2016 .SYNOPSIS....SHOWER CHANCES WILL DIMINISH DURING THE MORNING HOURS AS THE WEAK COLD FRONT NOW MOVING THROUGH OUR DISTRICT DISSIPATES. DRY WEATHER CONDITIONS WILL RETURN TO MOST AREAS BY LATE MORNING THURSDAY AND THEN CONTINUE THROUGH THE WEEKEND...ALONG WITH A SIGNIFICANT WARMING TREND. COOLING IS THEN EXPECTED MONDAY AND TUESDAY OF NEXT WEEK AS AN UPPER TROUGH APPROACHES THE WEST COAST. && .DISCUSSION...AS OF 4:05 AM PDT THURSDAY...SATELLITE IMAGERY SHOWS THE PRIMARY COLD FRONTAL CLOUD BAND PUSHING THROUGH THE MIDDLE OF OUR DISTRICT WHILE LATEST KMUX RADAR DATA SHOW AREAS OF SHOWERS EXTENDING FROM THE CENTRAL SF BAY AREA SOUTH THROUGH THE SANTA CRUZ MOUNTAINS. THE HIGHEST RAINFALL TOTAL NOTED THUS FAR IS 0.69 INCHES AT THE MIDDLE PEAK (MT TAMALPAIS) RAWS SITE IN MARIN COUNTY...WITH MOST LOWER ELEVATION LOCATIONS AROUND THE BAY HAVING RECEIVED LESS THAN TWO TENTHS OF AN INCH. LATEST HRRR AND NAM MODEL OUTPUT REMAIN IN GOOD AGREEMENT IN WEAKENING AND THEN DISSIPATING THE FRONT AS IT MOVES SOUTHWARD THROUGH MONTEREY COUNTY DURING THE FIRST PART OF THE MORNING. BY LATE MORNING DRY CONDITIONS ARE EXPECTED TO GENERALLY PREVAIL ACROSS THE CWA...WITH JUST A CHANCE OF A FEW LINGERING POST- FRONTAL LIGHT SHOWERS...PRIMARILY OVER NORTHERN SONOMA COUNTY. THE AIRMASS BEHIND THE FRONT WILL BE QUITE COOL...WITH 850 MB TEMPS FORECAST TO DROP AS LOW AS ZERO TO ONE DEG C IN THE NORTH BAY BY LATER THIS MORNING. BUT MID-APRIL DIURNAL HEATING WILL PARTIALLY COMPENSATE WITH THE NET RESULT OF LOWER ELEVATION MAX TEMPS AROUND THE BAYS STILL MOSTLY REACHING UP INTO THE LOWER TO MID 60S. IT WILL BE A BIT BRISK NEAR THE COAST THOUGH...AS NORTHWEST WINDS PICK UP THERE DURING THE AFTERNOON HOURS. THEN ON FRIDAY...MODELS REMAIN IN EXCELLENT AGREEMENT IN RAPIDLY BUILDING A STRONG UPPER LEVEL RIDGE NORTHEASTWARD INTO THE WEST COAST...AND SURFACE HIGH PRESSURE INTO THE PACIFIC NORTHWEST AND NORTHERN GREAT BASIN. SUNNY CONDITIONS ARE EXPECTED TO PREVAIL DISTRICTWIDE...AND IN COMBINATION WITH AIR MASS WARMING AND PROGRESSIVELY DRIER AND MORE OFFSHORE ORIENTED FLOW RESULT IN THE BEGINNING OF A SIGNIFICANT WARMING TREND. AFTERNOON HIGHS ON FRIDAY WILL GENERALLY BE 4 TO 7 DEG WARMER THAN THOSE TODAY...BUT LOCALLY UP TO 10-12 DEGREES WARMER IN NORTH BAY VALLEY LOCATIONS SUCH AS THE SANTA ROSA AREA WHERE DOWNSLOPE WARMING EFFECTS ARE MAXIMIZED. OVER THE WEEKEND...THE WARMING TREND WILL CONTINUE. BASED ON LATEST MODEL OUTPUT AND ASSOCIATED MOS GUIDANCE...ESPECIALLY FROM THE ECMWF WHICH TENDS TO DO WELL IN SUCH SITUATIONS...HAVE BUMPED UP AFTERNOON HIGHS BOTH SATURDAY AND SUNDAY FROM INHERITED GRIDS AND FORECASTS. CURRENT THINKING IS THAT WILL SEE WIDESPREAD MID 70S TO LOWER 80S ON SATURDAY...AND THEN 80S ACROSS MUCH OF THE DISTRICT ON SUNDAY WITH WARMEST INLAND LOCATIONS BRUSHING UPWARDS TOWARDS 90 DEG. IN THE EXTENDED...THE UPPER LEVEL RIDGE AXIS IS FORECAST TO BEGIN SHIFTING EASTWARD ALONG WITH A RETURN TO MORE ONSHORE ORIENTED SURFACE FLOW. THE NET RESULT WILL BE A SIGNIFICANT COOLING TREND WORKING ITS WAY INLAND MONDAY AND TUESDAY. LONGER RANGE MODELS DO GENERALLY AGREE THAT THE TAIL END OF AN UPPER LEVEL TROUGH WILL APPROACH OUR COAST IN THE TUESDAY TO TUESDAY NIGHT TIME FRAME...BUT RAIN CHANCES PRESENTLY APPEAR MINIMAL AS GENERAL CONSENSUS THAT IT WILL THEN WEAKEN AND LIFT QUICKLY TO THE NORTH- NORTHEAST BEFORE MOVING ONSHORE. && .AVIATION...AS OF 10:52 PM PDT WEDNESDAY...THE CURRENT IR SATELLITE IMAGE IS SHOWING MOSTLY HIGH CLOUDS OVER THE TERMINALS THIS EVENING...HOWEVER A COLD FRONT MOVING THROUGH NORTHERN CALIFORNIA AND IS QUICKLY APPROACHING THE NORTH BAY AREA AT THIS HOUR. THE COLD FRONT WILL SLIDE SOUTH OVERNIGHT RESULTING IN LIGHT RAIN AT ALL TERMINALS LATE TONIGHT. THE FRONT WILL BE OUT OF THE AREA BY SUNRISE FRIDAY MORNING. VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST MIDNIGHT. LIGHT RAIN IS ANTICIPATED BETWEEN 1000Z AND 1200Z WITH SHOWERS POSSIBLE FROM 1200Z TO 1500Z. WINDS ARE ANTICIPATED TO BE GENERALLY SOUTHWEST OVERNIGHT BECOMING WESTERLY THURSDAY AFTERNOON. CONFIDENCE IS MODERATE. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH AT LEAST MIDNIGHT. LIGHT RAIN IS ANTICIPATED BETWEEN 1100Z AND 1500Z. WINDS ARE ANTICIPATED TO INCREASE OUT OF THE SOUTHERLY DIRECTION OVERNIGHT AS THE FRONT NEARS THE MONTEREY COAST. WINDS ARE EXPECTED TO BECOME WESTERLY THURSDAY AFTERNOON. CONFIDENCE IS MODERATE. && .MARINE...AS OF 4:06 AM PDT THURSDAY...A COLD FRONT WILL CONTINUE TO MOVE RAPIDLY SOUTHEAST THIS MORNING. WINDS WILL BECOME NORTHWESTERLY TODAY. NORTHWESTERLY SWELLS WILL BUILD TODAY AND TONIGHT THEN SUBSIDE LATER FRIDAY INTO THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY SOUTH TO MONTEREY COUNTY SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 3 PM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 11 AM SCA...PT ARENA TO PT REYES 0-10 NM FROM 11 AM SCA...PT REYES TO PIGEON PT 0-10 NM FROM 3 PM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...MRY BAY FROM 11 AM && $$ PUBLIC FORECAST: BLIER AVIATION: LARRY MARINE: CANEPA VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1010 AM EDT THU APR 14 2016 .DISCUSSION... ...HIGHER RAIN CHANCES WILL CONTINUE THROUGH THE END OF THE WEEK... ...HAZARDOUS BOATING/BEACH CONDITIONS WILL DEVELOP THIS WEEKEND... CURRENT...FOG AND LOW CLOUDS SLOWLY LIFTING AND SHOULD BE PARTLY CLOUDY AROUND 10AM. SHOWERS AND STORMS IN THE ATLANTIC JUST BEYOND THE COASTAL WATERS FORECAST LIMIT OF 60NM WITH A SLOW SOUTHWARD DRIFT. INVERTED TROUGHING OVER THE COASTAL WATERS PRODUCING VARIABLE WINDS AT 5 TO 10 MPH. SHORT TERM MODELS...RAP40/HRRR...INDICATING THAT SHOWERS SHOULD START TO THE WEST NOON/EARLY AFTERNOON AND MOVE TO THE EAST AT AROUND 15 MPH. ISOLATED STORMS SHOULD START FORMING MID AFTERNOON AND ALSO MOVE EAST. PREVAILING WESTERLY WIND FLOW THROUGH 10000 FEET WILL PUSH SHOWERS AND STORMS TOWARD THE EAST COAST WHERE THEY WILL MOST LIKELY INTERACT WITH THE EAST COAST SEA BREEZE THAT IS CONFINED TO THE COASTAL COUNTIES EAST OF INTERSTATE 95. MORNING ZONES UPDATE WILL AMEND TIMING AND WORDING FOR THE AFTERNOON PERIOD. .AVIATION...TEMPO IFR/LIFR CEILINGS AND MVFR VIS INTERIOR KISM-KDED TIL 15Z THEN VFR. VCTS 18Z-06Z GOOD CALL AS TIMING OF TSTM DEVELOPMENT STILL UNCERTAIN. AFT 06Z VCSH LOOKS GOOD. .MARINE...VARIABLE WINDS 10 KNOTS BECOMING ONSHORE AFTER 1 PM AT THE COAST. SEA BREEZES WILL STRUGGLE TO MAKE IT INLAND VERY FAR AGAINST A PREVAILING WESTERLY WIND AROUND 10 KNOTS. PREVIOUS AFD ISSUED 420 AM EDT THU APR 14 2016 CURRENT...NEXRAD 88D SHOWS SCATTERED SHOWERS AND ISOLATED STORMS OVER THE GULF STREAM EARLY THIS MORNING. A WEAK BOUNDARY PUSHING SOUTH WITH OUTFLOW FROM THE PREVIOUS EVENING`S CONVECTION WILL LIE ACROSS AROUND LAKE OKEECHOBEE BY SUNRISE AND BECOME DIFFUSE SOON THEREAFTER. CONTINUED MILD AND MUGGY WITH BOTH TEMPERATURES/DEWPOINT READINGS WELL INTO THE 60S AREAWIDE. WINDS LIGHT/VARIABLE WITH MCLOUDY SKIES. WILL NEED TO MONITOR LOW STRATUS CLOUD/PATCHY GROUND FOG DEVELOPMENT EARLY THIS MORNING...ESPECIALLY ALONG/NORTH OF I-4 WITH ADDITIONAL MOISTURE NEAR THE SURFACE AS MOS GUIDANCE IS PICKING UP ON THIS. TODAY-TONIGHT...THROUGH THE MORNING WINDS WILL TRANSITION BACK TO S/SE ACROSS THE AREA. THIS ACCORDING TO LOCAL MODELS (HRRR/WRF). THE PRESSURE GRADIENT REMAINS FAIRLY LIGHT AND SUSPECT THERE WILL BE A DEGREE OF VARIABILITY TO DIRECTIONAL COMPONENT ON THIS DAY SO CONFIDENCE LOW HERE. WIND SPEEDS GENERALLY UNDER 10 MPH FOR MOST OF THE DAY. THE EAST COAST SEA BREEZE WILL DEVELOP BY EARLY AFTERNOON AND PUSH INLAND ONCE AGAIN AS WELL WILL THE WEST COAST SEA BREEZE ON THE OTHER SIDE OF THE PENINSULA. UNSETTLED CONDITIONS CONTINUE ALOFT AS PERIODIC VORTICITY IMPULSES TRAVERSE THE REGION. WILL NOT RULE OUT AN ISOLATED SHOWER DURING THE MORNING BUT SIMILAR TO YESTERDAY...AS THE AFTERNOON GROWS OLD...OUR SHOWER AND STORM CHANCES WILL INCREASE. SURFACE HEATING IS IN QUESTION A BIT BUT ANTICIPATE WE WILL SEE SOME PERIODS OF CLOUDS AS WELL AS SOME BREAKS. COOLER TEMPERATURES ALOFT AGAIN (-12C/-13C) AT 500MB PROMOTING INSTABILITY. EXPECT BOUNDARY COLLISIONS LATER IN THE DAY/EARLY EVENING ALLOWING FOR AN INCREASE IN COVERAGE TO LIKELY (60-70 PERCENT) FROM KMCO-KTTS NORTHWARD. CHANCE POPS SOUTH OF HERE (40-50 PERCENT). MOVEMENT OF ACTIVITY GENERALLY BACK TOWARDS THE EAST COAST AGAIN AT 10 TO 15 MPH. A FEW STRONG STORMS WILL BE POSSIBLE WITH CLOUD TO GROUND LIGHTNING...TORRENTIAL DOWNPOURS...GUSTY WINDS UP TO AROUND 45 MPH AND SMALL HAIL THE MAIN THREATS. AFTERNOON HIGHS IN THE L80S AREAWIDE. OVERNIGHT LOWS CONTINUED MILD AND GENERALLY IN THE M-U60S. FRI-SUN...GLOBAL MODEL GUIDANCE REMAINS CONSISTENT IN QUICKLY WEAKENING THE CTRL-ERN CONUS "REX" BLOCK FRIDAY WITH THE SYNOPTIC PATTERN OVER THE CONUS TRANSITIONS TO A WELL DEVELOPED OMEGA BLOCK BY THIS WEEKEND. RAPIDLY WEAKENING H50 LOW DRIFTS EWD ACROSS THE SE CONUS BENEATH THE "REX HIGH" FRI...BEFORE SHEARING OUT RAPIDLY FRI NIGHT/SAT. RESIDUAL RIBBON OF H50 VORT LINGERS ACROSS THE STATE THROUGH THE WEEKEND WITH THE PREFERRED GFS CONTINUING TO SHOW MORE SLOWER SHEARING AND THUS MORE RESIDUAL MID LEVEL TROUGHING HANGING BACK ACROSS FL ON SAT. AXIS OF THE RIDGE ANCHORING THE OMEGA WILL RETROGRADE SLIGHTLY THROUGH THE WEEKEND...AS THE S TO SSW MOVING WRN ATLC LOW DOES THE SAME. AT THE SFC...WEAK INVERTED TROUGH OVER THE STATE FRI GETS FLATTENED AT BY NE SURGE BTWN WITH THE STRONG SFC HIGH TO THE NORTH AND THE DEEPENING LOW TO ITS EAST OVER THE WRN ATLC. PATTERN STILL SHAPING UP TO BE WET FRI-SAT (LIKELY POPS BOTH DAYS) AND STRONG STORMS ARE A DECENT BET FRIDAY AS TEMPS COOL ALOFT (13C/- 14C @H50) IN PRESENCE OF DEEP MOISTURE AND ENHANCED LOW LEVEL CONVG. SAT LOOKS SHOWERY WITH DEEP MOISTURE STILL DRAPED OVER THE REGION... BUT LOWER CHC FOR STORMS GIVEN STRENGTHENING ONSHORE WINDS SHOULD RESULT IN DECREASED SFC BASED CONVG/INSTABILITY. HOWEVER... TEMPS H50 TEMPS ARE ACTUALLY ABOUT A DEGREE COLDER...SO CAN`T RULE OUT AN ISOLD TS. DEEP MOISTURE FINALLY GETS SHUNTED SOUTH SAT NIGHT/ SUN WITH JUST A SMALL CHC FOR A COASTAL SHOWER IN CONTINUED BREEZY ONSHORE (ENE TO NE) WIND FLOW. TEMPS A LITTLE ABOVE NORMAL FRI-FRI NIGHT WILL DROP BACK CLOSER TO NORMAL THIS WEEKEND WITH WINDS PROBABLY HOLDING MINS ABOVE GUIDANCE ALONG THE IMMEDIATE COAST. MON-WED...FORECAST REMAINS DRY FROM EARLY-MID NEXT WEEK AS HIGH PRES SETTLES SWD OVER FL. SOME INDICATIONS BY THE GFS OF A WEAK BACK DOOR FRONT TAKING A RUN AT NORTH FL LATE WED...BUT WITH THE ECM KEEPING THIS FEATURE WELL TO THE N/E...NOT BITING OFF ON THAT SOLN. TEMPS START OFF A DEG OR SO JUST OFF CLIMO BEFORE WARMING TO NORMAL TUE-WED. && .AVIATION...WILL MONITOR AGAIN EARLY THIS MORNING FOR SOME LOWER CIGS NEAR/NORTH OF I-4 AS SUGGESTED BY MOS GUIDANCE. SOME PATCHY GROUND FOG CANNOT BE RULED OUT DUE TO MOISTURE NEAR THE SURFACE FROM THE PREVIOUS EVENING`S RAINS WHICH WE HAVEN`T SEEN IN A WHILE. LOW CONFIDENCE IN WIND DIRECTIONAL COMPONENT...THOUGH HRRR SHOWS CURRENT LIGHT NORTHERLY COMPONENT BECOMING S/SE LATER IN THE MORNING. ANTICIPATE VARIABILITY IN WIND DIRECTION TODAY WITH SPEEDS GENERALLY LESS THAN 10 KTS. THE ECSB WILL DEVELOP AGAIN TODAY AND PUSH INLAND WITH COLLISION LATE DAY/EARLY EVENING WITH ITS WEST COAST COUNTERPART. THE MAJORITY OF THE RESULTANT COLLISION CONVECTION SHOULD FAVOR THE EASTERN PENINSULA WITH WESTERLY STEERING FLOW ALOFT. CURRENTLY HAVE VCTS IN THE TAFS FOR LATER IN THE AFTERNOON. TEMPO GROUPS LIKELY WITH FURTHER CONFIDENCE IN TIMING. SCT-NMRS SHRA COVERAGE AND ISOLD-SCT TSRA COVERAGE FOR LATE DAY/EVENING. PERIODIC IMPULSES TRAVELING ACROSS THE AREA LATER TODAY MAY AID IN A FEW STRONG STORMS. && .MARINE...TODAY-TONIGHT...GENERALLY LIGHT/VARIABLE WINDS ACROSS THE COASTAL WATERS THIS MORNING WITH WEAK PRESSURE GRADIENT IN PLACE AND DISTORTED WIND FIELD FROM THE PREVIOUS NIGHT`S CONVECTION. VARIOUS MODELS NOT HANDLING TODAY`S WIND FIELDS VERY WELL SO LOW CONFIDENCE IN DIRECTIONAL COMPONENT...THOUGH SPEEDS GENERALLY LESS THAN 10 KTS. THE ECSB WILL DEVELOP EARLY THIS AFTERNOON AND PUSH SLOWLY INLAND SO AN ONSHORE FLOW EXPECTED ALONG THE SPACE/TREASURE COAST AT LEAST BY LATER IN THE MORNING OR EARLY AFTERNOON. WITH A RESIDUAL SURFACE BOUNDARY SLIDING SOUTH INTO THE AREA LATER TODAY MAY SEE MORE S/SERLY WINDS THRU MUCH OF THE DAY...EXCEPT E/NERLY WINDS VOLUSIA COAST IF BOUNDARY TO THE NORTH SLIDES A BIT QUICKER SOUTHWARD. SEAS BUILDING 3-4 FT NEAR SHORE TODAY AND MAINLY 4-5 FT NORTH OF SEBASTIAN INLET OFFSHORE. SEAS MAY CONTINUE TO BUILD TOWARD 6 FEET LATE TONIGHT WELL OFFSHORE OF THE VOLUSIA COAST. AN EAST-NORTHEAST LONG PERIOD SWELL WILL BE SLOWLY INCREASING THROUGH LATE IN THIS PERIOD. WITH DEEPER MOISTURE IN PLACE...VARIOUS DISTURBANCES ALOFT MOVING ACROSS THE AREA AND DEVELOPING TROUGHING ALONG THE EAST FL COAST EXPECT AN INCREASED THREAT FOR SHOWERS AND ISOLD STORMS...ESPECIALLY NORTH OF THE CAPE. A FEW STORMS MAY AGAIN MOVE OFF OF THE EAST COAST LATE IN THE DAY AND THIS EVENING. A FEW COULD BE STRONG. WINDS/SEAS LOCALLY HIGHER INVOF SHOWERS/STORMS. FRI-MON...PRESENCE OF TROUGH OVER THE AREA FRIDAY WILL KEEP WINDS AND SEAS BLO 15KT FOR MOST OF THE MAOR THROUGH FRI NIGHT HOWEVER HIGHER WINDS/SEAS MAY LEAK INTO THE VOLUSIA WATERS (15-20KT/6-9FT) LATE IN THE DAY AS TROUGH AXIS SLIPS SWD A BIT. BOATING AND BEACH CONDITIONS WILL DETERIORATE RAPIDLY N-S ON SAT AS STRONG NE TO ENE WIND SURGE COUPLED WITH LENGTHENING NE FETCH BTWN STRONG ERN CONUS HIGH/DEEP WRN ATLC LOW CAUSES BOTH AN INCREASING WIND CHOP AND BUILDING NE SWELL. 6-9FT SEAS WILL OVERSPREAD MUCH OF THE MAOR SAT...WITH 6-9FT SEAS EXPECTED NEAR SHORE AND 10-11FT SEAS WELL OFFSHORE THROUGH MONDAY. BOATERS AND BEACHGOERS ARE REMINDED THAT THIS REMAINS A VERY HIGH CONFIDENCE MARINE EVENT GIVEN THE MODEL AGREEMENT AND PERSISTENCE. SCA WILL LIKELY BE NEEDED THIS WEEKEND...POSSIBLY AS EARLY AS LATE FRI FOR THE VOLUSIA COUNTY WATERS. A HIGH SURF ADVISORY MAY NEED TO BE CONSIDERED AS WELL FOR LATE SAT THROUGH MON. && .PRELIMINARY POINT TEMPS/POPS... DAB 80 64 78 66 / 70 50 60 40 MCO 84 65 83 66 / 60 50 70 40 MLB 83 65 79 68 / 50 30 70 40 VRB 83 65 81 67 / 40 40 70 40 LEE 81 64 80 64 / 70 40 60 40 SFB 82 65 81 65 / 70 50 60 40 ORL 83 66 81 66 / 60 50 70 40 FPR 84 64 80 67 / 40 40 70 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ LONG TERM/IMPACT WX...BRAGAW SHORT TERM/AVIATION...WIMMER
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
745 AM EDT THU APR 14 2016 .DISCUSSION... ...HIGHER RAIN CHANCES WILL CONTINUE THROUGH THE END OF THE WEEK... ...HAZARDOUS BOATING/BEACH CONDITIONS WILL DEVELOP THIS WEEKEND... .AVIATION...SEVERAL TAF SITES RECORDING IFR/LIFR CEILINGS AND IFR/MVFR VISIBILITY AT THE COAST FROM FORT PIERCE NORTH. FLIGHT CONDITIONS SHOULD JUMP AROUND FROM AS LOW AS LIFR TO VFR NEXT HOUR THEN PREVAILING VFR WITH THE LOW CLOUDS/FOG/MIST HAVING LIFTED/BURNED OFF. WILL WATCH OBS AND AMEND ACCORDINGLY. PREVIOUS AFD ISSUED 420 AM EDT THU APR 14 2016 CURRENT...NEXRAD 88D SHOWS SCATTERED SHOWERS AND ISOLATED STORMS OVER THE GULF STREAM EARLY THIS MORNING. A WEAK BOUNDARY PUSHING SOUTH WITH OUTFLOW FROM THE PREVIOUS EVENING`S CONVECTION WILL LIE ACROSS AROUND LAKE OKEECHOBEE BY SUNRISE AND BECOME DIFFUSE SOON THEREAFTER. CONTINUED MILD AND MUGGY WITH BOTH TEMPERATURES/DEWPOINT READINGS WELL INTO THE 60S AREAWIDE. WINDS LIGHT/VARIABLE WITH MCLOUDY SKIES. WILL NEED TO MONITOR LOW STRATUS CLOUD/PATCHY GROUND FOG DEVELOPMENT EARLY THIS MORNING...ESPECIALLY ALONG/NORTH OF I-4 WITH ADDITIONAL MOISTURE NEAR THE SURFACE AS MOS GUIDANCE IS PICKING UP ON THIS. TODAY-TONIGHT...THROUGH THE MORNING WINDS WILL TRANSITION BACK TO S/SE ACROSS THE AREA. THIS ACCORDING TO LOCAL MODELS (HRRR/WRF). THE PRESSURE GRADIENT REMAINS FAIRLY LIGHT AND SUSPECT THERE WILL BE A DEGREE OF VARIABILITY TO DIRECTIONAL COMPONENT ON THIS DAY SO CONFIDENCE LOW HERE. WIND SPEEDS GENERALLY UNDER 10 MPH FOR MOST OF THE DAY. THE EAST COAST SEA BREEZE WILL DEVELOP BY EARLY AFTERNOON AND PUSH INLAND ONCE AGAIN AS WELL WILL THE WEST COAST SEA BREEZE ON THE OTHER SIDE OF THE PENINSULA. UNSETTLED CONDITIONS CONTINUE ALOFT AS PERIODIC VORTICITY IMPULSES TRAVERSE THE REGION. WILL NOT RULE OUT AN ISOLATED SHOWER DURING THE MORNING BUT SIMILAR TO YESTERDAY...AS THE AFTERNOON GROWS OLD...OUR SHOWER AND STORM CHANCES WILL INCREASE. SURFACE HEATING IS IN QUESTION A BIT BUT ANTICIPATE WE WILL SEE SOME PERIODS OF CLOUDS AS WELL AS SOME BREAKS. COOLER TEMPERATURES ALOFT AGAIN (-12C/-13C) AT 500MB PROMOTING INSTABILITY. EXPECT BOUNDARY COLLISIONS LATER IN THE DAY/EARLY EVENING ALLOWING FOR AN INCREASE IN COVERAGE TO LIKELY (60-70 PERCENT) FROM KMCO-KTTS NORTHWARD. CHANCE POPS SOUTH OF HERE (40-50 PERCENT). MOVEMENT OF ACTIVITY GENERALLY BACK TOWARDS THE EAST COAST AGAIN AT 10 TO 15 MPH. A FEW STRONG STORMS WILL BE POSSIBLE WITH CLOUD TO GROUND LIGHTNING...TORRENTIAL DOWNPOURS...GUSTY WINDS UP TO AROUND 45 MPH AND SMALL HAIL THE MAIN THREATS. AFTERNOON HIGHS IN THE L80S AREAWIDE. OVERNIGHT LOWS CONTINUED MILD AND GENERALLY IN THE M-U60S. FRI-SUN...GLOBAL MODEL GUIDANCE REMAINS CONSISTENT IN QUICKLY WEAKENING THE CTRL-ERN CONUS "REX" BLOCK FRIDAY WITH THE SYNOPTIC PATTERN OVER THE CONUS TRANSITIONS TO A WELL DEVELOPED OMEGA BLOCK BY THIS WEEKEND. RAPIDLY WEAKENING H50 LOW DRIFTS EWD ACROSS THE SE CONUS BENEATH THE "REX HIGH" FRI...BEFORE SHEARING OUT RAPIDLY FRI NIGHT/SAT. RESIDUAL RIBBON OF H50 VORT LINGERS ACROSS THE STATE THROUGH THE WEEKEND WITH THE PREFERRED GFS CONTINUING TO SHOW MORE SLOWER SHEARING AND THUS MORE RESIDUAL MID LEVEL TROUGHING HANGING BACK ACROSS FL ON SAT. AXIS OF THE RIDGE ANCHORING THE OMEGA WILL RETROGRADE SLIGHTLY THROUGH THE WEEKEND...AS THE S TO SSW MOVING WRN ATLC LOW DOES THE SAME. AT THE SFC...WEAK INVERTED TROUGH OVER THE STATE FRI GETS FLATTENED AT BY NE SURGE BTWN WITH THE STRONG SFC HIGH TO THE NORTH AND THE DEEPENING LOW TO ITS EAST OVER THE WRN ATLC. PATTERN STILL SHAPING UP TO BE WET FRI-SAT (LIKELY POPS BOTH DAYS) AND STRONG STORMS ARE A DECENT BET FRIDAY AS TEMPS COOL ALOFT (13C/- 14C @H50) IN PRESENCE OF DEEP MOISTURE AND ENHANCED LOW LEVEL CONVG. SAT LOOKS SHOWERY WITH DEEP MOISTURE STILL DRAPED OVER THE REGION... BUT LOWER CHC FOR STORMS GIVEN STRENGTHENING ONSHORE WINDS SHOULD RESULT IN DECREASED SFC BASED CONVG/INSTABILITY. HOWEVER... TEMPS H50 TEMPS ARE ACTUALLY ABOUT A DEGREE COLDER...SO CAN`T RULE OUT AN ISOLD TS. DEEP MOISTURE FINALLY GETS SHUNTED SOUTH SAT NIGHT/ SUN WITH JUST A SMALL CHC FOR A COASTAL SHOWER IN CONTINUED BREEZY ONSHORE (ENE TO NE) WIND FLOW. TEMPS A LITTLE ABOVE NORMAL FRI-FRI NIGHT WILL DROP BACK CLOSER TO NORMAL THIS WEEKEND WITH WINDS PROBABLY HOLDING MINS ABOVE GUIDANCE ALONG THE IMMEDIATE COAST. MON-WED...FORECAST REMAINS DRY FROM EARLY-MID NEXT WEEK AS HIGH PRES SETTLES SWD OVER FL. SOME INDICATIONS BY THE GFS OF A WEAK BACK DOOR FRONT TAKING A RUN AT NORTH FL LATE WED...BUT WITH THE ECM KEEPING THIS FEATURE WELL TO THE N/E...NOT BITING OFF ON THAT SOLN. TEMPS START OFF A DEG OR SO JUST OFF CLIMO BEFORE WARMING TO NORMAL TUE-WED. && .AVIATION...WILL MONITOR AGAIN EARLY THIS MORNING FOR SOME LOWER CIGS NEAR/NORTH OF I-4 AS SUGGESTED BY MOS GUIDANCE. SOME PATCHY GROUND FOG CANNOT BE RULED OUT DUE TO MOISTURE NEAR THE SURFACE FROM THE PREVIOUS EVENING`S RAINS WHICH WE HAVEN`T SEEN IN A WHILE. LOW CONFIDENCE IN WIND DIRECTIONAL COMPONENT...THOUGH HRRR SHOWS CURRENT LIGHT NORTHERLY COMPONENT BECOMING S/SE LATER IN THE MORNING. ANTICIPATE VARIABILITY IN WIND DIRECTION TODAY WITH SPEEDS GENERALLY LESS THAN 10 KTS. THE ECSB WILL DEVELOP AGAIN TODAY AND PUSH INLAND WITH COLLISION LATE DAY/EARLY EVENING WITH ITS WEST COAST COUNTERPART. THE MAJORITY OF THE RESULTANT COLLISION CONVECTION SHOULD FAVOR THE EASTERN PENINSULA WITH WESTERLY STEERING FLOW ALOFT. CURRENTLY HAVE VCTS IN THE TAFS FOR LATER IN THE AFTERNOON. TEMPO GROUPS LIKELY WITH FURTHER CONFIDENCE IN TIMING. SCT-NMRS SHRA COVERAGE AND ISOLD-SCT TSRA COVERAGE FOR LATE DAY/EVENING. PERIODIC IMPULSES TRAVELING ACROSS THE AREA LATER TODAY MAY AID IN A FEW STRONG STORMS. && .MARINE...TODAY-TONIGHT...GENERALLY LIGHT/VARIABLE WINDS ACROSS THE COASTAL WATERS THIS MORNING WITH WEAK PRESSURE GRADIENT IN PLACE AND DISTORTED WIND FIELD FROM THE PREVIOUS NIGHT`S CONVECTION. VARIOUS MODELS NOT HANDLING TODAY`S WIND FIELDS VERY WELL SO LOW CONFIDENCE IN DIRECTIONAL COMPONENT...THOUGH SPEEDS GENERALLY LESS THAN 10 KTS. THE ECSB WILL DEVELOP EARLY THIS AFTERNOON AND PUSH SLOWLY INLAND SO AN ONSHORE FLOW EXPECTED ALONG THE SPACE/TREASURE COAST AT LEAST BY LATER IN THE MORNING OR EARLY AFTERNOON. WITH A RESIDUAL SURFACE BOUNDARY SLIDING SOUTH INTO THE AREA LATER TODAY MAY SEE MORE S/SERLY WINDS THRU MUCH OF THE DAY...EXCEPT E/NERLY WINDS VOLUSIA COAST IF BOUNDARY TO THE NORTH SLIDES A BIT QUICKER SOUTHWARD. SEAS BUILDING 3-4 FT NEAR SHORE TODAY AND MAINLY 4-5 FT NORTH OF SEBASTIAN INLET OFFSHORE. SEAS MAY CONTINUE TO BUILD TOWARD 6 FEET LATE TONIGHT WELL OFFSHORE OF THE VOLUSIA COAST. AN EAST-NORTHEAST LONG PERIOD SWELL WILL BE SLOWLY INCREASING THROUGH LATE IN THIS PERIOD. WITH DEEPER MOISTURE IN PLACE...VARIOUS DISTURBANCES ALOFT MOVING ACROSS THE AREA AND DEVELOPING TROUGHING ALONG THE EAST FL COAST EXPECT AN INCREASED THREAT FOR SHOWERS AND ISOLD STORMS...ESPECIALLY NORTH OF THE CAPE. A FEW STORMS MAY AGAIN MOVE OFF OF THE EAST COAST LATE IN THE DAY AND THIS EVENING. A FEW COULD BE STRONG. WINDS/SEAS LOCALLY HIGHER INVOF SHOWERS/STORMS. FRI-MON...PRESENCE OF TROUGH OVER THE AREA FRIDAY WILL KEEP WINDS AND SEAS BLO 15KT FOR MOST OF THE MAOR THROUGH FRI NIGHT HOWEVER HIGHER WINDS/SEAS MAY LEAK INTO THE VOLUSIA WATERS (15-20KT/6-9FT) LATE IN THE DAY AS TROUGH AXIS SLIPS SWD A BIT. BOATING AND BEACH CONDITIONS WILL DETERIORATE RAPIDLY N-S ON SAT AS STRONG NE TO ENE WIND SURGE COUPLED WITH LENGTHENING NE FETCH BTWN STRONG ERN CONUS HIGH/DEEP WRN ATLC LOW CAUSES BOTH AN INCREASING WIND CHOP AND BUILDING NE SWELL. 6-9FT SEAS WILL OVERSPREAD MUCH OF THE MAOR SAT...WITH 6-9FT SEAS EXPECTED NEAR SHORE AND 10-11FT SEAS WELL OFFSHORE THROUGH MONDAY. BOATERS AND BEACHGOERS ARE REMINDED THAT THIS REMAINS A VERY HIGH CONFIDENCE MARINE EVENT GIVEN THE MODEL AGREEMENT AND PERSISTENCE. SCA WILL LIKELY BE NEEDED THIS WEEKEND...POSSIBLY AS EARLY AS LATE FRI FOR THE VOLUSIA COUNTY WATERS. A HIGH SURF ADVISORY MAY NEED TO BE CONSIDERED AS WELL FOR LATE SAT THROUGH MON. && .PRELIMINARY POINT TEMPS/POPS... DAB 80 64 78 66 / 70 50 60 40 MCO 84 65 83 66 / 60 50 70 40 MLB 83 65 79 68 / 50 30 70 40 VRB 83 65 81 67 / 40 40 70 40 LEE 81 64 80 64 / 70 40 60 40 SFB 82 65 81 65 / 70 50 60 40 ORL 83 66 81 66 / 60 50 70 40 FPR 84 64 80 67 / 40 40 70 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ LONG TERM/IMPACT WX...BRAGAW SHORT TERM/AVIATION...WIMMER Area Forecast Discussion National Weather Service Dodge City KS 728 AM CDT THU APR 14 2016 .SHORT TERM...(Today and tonight) Issued at 256 AM CDT Thu Apr 14 2016 Stratus expanding across the area this morning, and it`s potential impacts on the temperature through the day is the immediate weather story. Fog was overdone in the NAM model, and may be overdone as well by the HRRR solutions going forward early this morning. However the expansion of stratus with bases at or under 500 ft continues this morning in a weak moisture advection environment. Going forward this afternoon, the models account for cloud dissipation by having much cooler temperatures in central Kansas. The surface high pressure will continue to shift east of the Mississippi valley, increasing the surface pressure gradient over western KS, and allowing moderate to strong southerly winds to develop especially once mixing maximizes this afternoon. Very low pops are in place tonight, following the convective allowing models reflectivity fields/weak cape and upslope environment with exiting shortwave ridge. however the real increase in precipitation chances comes on Friday afternoon with what could potentially be a few severe thunderstorms given the low to moderate cape values and strong bulk shear. .LONG TERM...(Friday through Wednesday) Issued at 256 AM CDT Thu Apr 14 2016 A well advertised so far thunderstorm/heavy rain event is still the main story in the medium range timeframe. All of the models are consistent in the large upper low stalling over the far southern Rockies/northern New Mexico region from Friday night into Monday morning. The gulf fetch will be wide open for this event, and a persistent rain looks to really get going by late Saturday and not end until early Monday at best. Several inches of rain are likely across most of the forecast area, and even localized flooding possible becoming a reality where rainfall duration and intensity are largest over low lying drainage areas. && .AVIATION...(For the 12Z TAFS through 12Z Friday Morning) Issued at 726 AM CDT Thu Apr 14 2016 Widespread low stratus developed during the overnight hours producing IFR flight category ceiling, generally 500 to 700 feet. Wind speeds in the 13 to 16 knot range have prevented development of sustained dense fog. The stratus and IFR ceiling are expected to dissipate by late morning with the onset of insolation. The south- southeast winds will continue with gusts in the upper 20s knots through this evening. With low level moisture now in place, we will likely see the redevelopment of IFR ceilings in low stratus again early Friday morning. && .PRELIMINARY POINT TEMPS/POPS... DDC 72 53 74 55 / 0 10 30 50 GCK 75 53 74 53 / 10 20 50 60 EHA 80 54 75 52 / 10 10 70 60 LBL 77 53 75 54 / 0 10 50 70 HYS 72 52 74 54 / 0 20 30 50 P28 70 52 76 57 / 0 10 20 30 && .DDC Watches/Warnings/Advisories...NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1008 AM CDT THU APR 14 2016 .SOUNDING DISCUSSION... NO ISSUES WITH FLIGHT THIS MORNING DESPITE SOME LIGHT RAIN AT OB TIME. RATHER SATURATED COLUMN TO ABOUT 320 MB WITH PRECIPITABLE WATER 1.57 INCHES. PRECIP LOADED APPEARANCE WITH SKINNY CAPE ON 339K LIFT FROM SURFACE. ALLOWING FOR DAYTIME HEATING DOES GET A LIFT OF 342K BASED AT LCL 877MB. CHAP OUTPUT YIELDS A 57% CHANCE OF THUNDERSTORMS...GUST POTENTIAL 35 KT...PEA HAIL WITH A VIL OF 66. H50 TEMPERATURE OF -13C IS A POSITIVE FACTOR FOR HAIL...ESPECIALLY IF THE COLUMN DOES DRY DOWNWARD FROM 300MB. RAIN POTENTIAL IS INDICATED TO BE IN THE 2.5-5.0 INCH RANGE. WIND PROFILE SHOWED SE FLOW BETWEEN 5-15 KNOTS BELOW 4KFT...THEN SW-W 15 TO 115 KT ABOVE. PEAK WIND 268/113KT AT 38.3KFT. TROPOPAUSE WAS AT 201MB WITH A TEMPERATURE OF -55.7C. FLIGHT TERMINATED AT 5.9 MB OR 21.5 MILES UP OVER JACKSON CO MS NEAR THE INTERSECTION OF HIGHWAY 57 AND GAUTIER-VANCLEAVE RD...65 MILES DOWNRANGE OF THE STATION. 24/RR && .PREV DISCUSSION... /ISSUED 322 AM CDT THU APR 14 2016/ SHORT TERM... ACTIVE WEATHER DAY ALREADY GETTING STARTED ACROSS THE FORECAST AREA EARLY THIS MORNING. A STALLED FRONTAL BOUNDARY DRAPED ALONG THE LA COAST...ACROSS THE NORTHERN GULF IN GENERAL...WILL BE THE FOCUS FOR THE BULK OF RAINFALL TODAY. RADAR SHOWS SHOWERS AND ISOLATED THUNDERSTORMS BEGINNING TO EXPAND IN COVERAGE MAINLY SOUTH OF A BATON ROUGE TO GULFPORT LINE. MESO AND MEDIUM RANGE MODELS INDICATE THAT CONVECTION WILL SPREAD NORTH AND EAST THROUGHOUT THE MORNING HOURS BEFORE SHIFTING EAST INTO ALABAMA THIS AFTERNOON. DURING THAT TIME...A JET NOSE COMING IN FROM TEXAS IN COMBINATION WITH DAYTIME HEATING...WILL PROMOTE MORE ROBUST THUNDERSTORMS MAINLY IN THE NWRN HALF OF THE CWA. THINKING BATON ROUGE METRO AND INTO SW MISSISSIPPI. BTR AND MCB MODEL SOUNDINGS LOOK PRIMED FOR HAIL PRODUCING STORMS WITH 1000-1500J/KG OF CAPE...LI/S -4 TO -6 AND WBZ HEIGHT OF AROUND 10KFT. WINDS...ALTHOUGH VEERING NICELY FROM SE AT THE SFC TO WEST ALOFT...ARE GENERALLY WEAK IN LOWER LAYERS AND THUS POSE A MINIMAL THREAT FOR DAMAGING WINDS AND/OR TORNADO DEVELOPMENT. SO THINKING HAIL WILL BE THE MAIN HAZARD TODAY. THE HRRR DOES INDICATE CELLULAR DEVELOPMENT IN THE 18-20Z TIME FRAME SO WILL HAVE TO MONITOR FOR POSSIBLE SVR WARNINGS. UPPER LEVEL LOW CENTER NORTH OF THE AREA WILL BEGIN TO BREAK DOWN FRIDAY WHILE RIDGE BEGINS TO BUILD IN THE AREA FROM THE WEST ON FRIDAY. THIS WILL CAUSE A EASTWARD SHIFT IN CONVECTION. FOR NOW HAVE POPS RANGING FROM 30S IN SWRN ZONES TO NEAR 50 PERCENT IN SW AND COASTAL MISSISSIPPI. THAT MAY BE SLIGHTLY GENEROUS. RAIN CHANCES LOOK TO DROP CONSIDERABLY SATURDAY AND SUNDAY AS THE WEAK RIDGE SLIDES OVERHEAD WITH NEXT CLOSED LOW STATIONARY OVER THE 4-CORNERS REGION. LONG TERM... UPPER LEVEL RIDGE OVER THE AREA THIS WEEKEND WILL SPREAD NORTH TO THE GREAT LAKES BY EARLY NEXT WEEK. THIS WILL BRING HIGH TEMPS BACK UP INTO THE UPPER 70S SUNDAY INTO MONDAY. A TROUGH DIPPING ACROSS THE NORTHEAST WILL SUPPRESS THE RIDGE SOUTH ON TUESDAY AND KEEP IT THERE THE REMAINDER OF THE WEAK. MEANWHILE...CLOSED LOW TO THE WEST WILL OPEN INTO MORE OF AN OPEN WAVE AS IT SLOWLY PROGRESSES EASTWARD ACROSS THE CENTRAL PLAINS. THIS MOVEMENT COULD TAKE THE ENTIRE WEEK TO TAKE PLACE. LOCAL RAIN CHANCES WILL BEGIN TO INCREASE DURING THIS TIME WITH SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. MEFFER AVIATION... SH/TS WILL DEVELOP AND MOVE NORTHEAST THROUGH THE AREA TODAY. MOST OF THIS ACTIVITY SHOULD AFFECT TERMINALS OVER THE SOUTHERN HALF OF THE AREA TODAY. WILL KEEP PREVAILING TS GROUPS FOR TERMINALS MAINLY ALONG AND SOUTH OF I-10/12. CEILINGS WILL ALSO BE AT SEVERAL DIFFERENT LEVELS BREAKING AND COVERING THROUGHOUT THE DAY. EXPECT MOST TO BE FROM BKN008-015 AND SOME TO BE AT OVC030. CEILINGS SHOULD FALL TO AROUND OVC005 AGAIN TONIGHT. MARINE... SH/TS WILL BE THE BIGGEST CONCERN TODAY AND FRIDAY.SOME OF THESE COULD BECOME SEVERE TODAY. WINDS AND SEAS WILL BE HIGHEST NEAR THIS ACTIVITY. THE CURRENT TROUGH AXIS THAT HAS SETTLED OVER THE GULF WILL HELP A VERY WEAK SFC LOW DEVELOP THROUGH TONIGHT. HIGH PRESSURE WILL INTERACT WITH THIS LOW AS IT RIDGES SOUTHWEST INTO THE NORTHERN GULF CAUSING A STRONGER GRADIENT FLOW TO SET UP STARTING THURSDAY NIGHT THROUGH THE WEEKEND. WINDS SHOULD BE EAST AT 15 TO 20 KNOTS BY THURSDAY NIGHT OVER WATERS EAST OF THE MISS RIVER AND GRADUALLY WORK THEIR WAY WESTWARD INTO THE REMAINING WATERS WEST OF THE RIVER BY FRIDAY EVENING. WINDS SHOULD EASE BACK SOMEWHAT BY THE START OF NEXT WEEK. DECISION SUPPORT... DSS CODE....GREEN. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...MINOR RIVER FLOODING. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 75 60 71 58 / 70 60 50 20 BTR 77 62 74 61 / 70 40 40 20 ASD 76 63 72 61 / 80 60 50 20 MSY 75 65 74 64 / 80 60 40 20 GPT 73 62 70 60 / 80 60 50 20 PQL 74 60 71 59 / 80 60 50 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
914 AM EDT THU APR 14 2016 .SYNOPSIS... HIGH PRESSURE REMAINS CENTERED WELL NORTH OF THE AREA THROUGH THE WEEKEND...RESULTING IN AN EXTENDED PERIOD OF DRY WEATHER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST SFC ANALYSIS SHOWS BROAD STRONG HI PRES CENTERED OVER SE CANADA. ALOFT...AN UPR-LEVEL TROF IS PIVOTING OFF THE ERN SEABOARD. DRY WX CONTINUES TDA WITH THE MID ATLC UNDER THE INFLUENCE OF THE SFC HI TO THE N. INCLUDED PATCHY FROST THIS MORNG IN PARTS OF THE CWA WITH TEMPS GETTING A COUPLE DEGREES LWR THAN PREVIOUSLY EXPECTED...BUT NOT WIDESPREAD OR LONG-LASTING ENUF TO WARRANT A FROST ADVSRY. ASIDE FM A FEW HI CLOUDS OVER SERN AREAS THIS MORNG...EXPECT A SUNNY SKY TDA UNDER N/NE FLOW. LOCAL LO- LEVEL THICKNESS TOOL WHICH HANDLED TEMPS WELL YESTERDAY CONTINUES TO INDICATE TEMPS ONLY REACHING THE UPR 50S TO LWR 60 MOST AREAS TDA...ABOUT FIVE TO 10 DEGREES BLO NORMAL FOR MID APRIL. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... LITTLE CHANGE SEEN IN THE BLOCKY PATTERN INTO THE WEEKEND. SFC HIGH TO THE NORTH PROGGED TO EXTEND DOWN THE EASTERN SEABOARD RESULTING IN A DRY PERIOD WITH ONLY SCT TO BKN HIGH / MID LEVEL CLOUDS FROM TIME TO TIME. PERSISTENT ONSHORE FLOW KEEPS TEMPS BELOW NORMAL BUT H85 TEMPS PROGGED TO SLOWLY RECOVER OVER TIME. THUS...SHOULD SEE HIGHS AND LOWS ABOUT 1-2 DEGREES WARMER EACH DAY. LOWS TONITE 35-40 AWAY FROM THE WATER...L-M40S AT THE BEACHES. HIGHS FRI IN THE L60S WEST OF THE BAY...55-60 ALONG THE COAST. LOWS FRI NITE U30S-M40S. HIGHS SAT L-M60S WEST OF THE BAY...U50S TO NEAR 60 ALONG THE COAST. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE CONTINUES TO WEDGE DOWN THE LEESIDE OF THE APPALACHIANS SAT NIGHT AS AN UPPER LEVEL RIDGE REMAINS STEADFAST OVER THE ERN HALF OF THE US. LOWS IN THE LOWER 40S INLAND AND AROUND 50 AT THE IMMEDIATE COAST. THE WEDGE ALONG THE APPALACHIANS BREAKS DOWN SUN AS THE HIGH SLIDES ACROSS THE REGION AND OVER THE GULF COAST STATES SUN NIGHT. ONSHORE N-NE WINDS WILL PERSIST DURING THIS TIME AND KEEP DAYTIME TEMPS COOL NEAR THE COAST. HIGHS IN THE UPPER 60S TO AROUND 70 INLAND...UPPER 50S TO LOWER 60S NEAR THE COAST. LOWS SUN NIGHT IN THE MID-UPPER 40S INLAND...LOW 50S BEACHES. A SFC LOW TRACKING ALONG THE US/SE CANADIAN BORDER SUN NIGHT GETS PUSHED DOWN ACROSS NRN NEW ENGLAND MON AND DRAGS A WEAK BACKDOOR FRONT ACROSS THE AREA MON NIGHT. THIS SHOULD RESULT IN A WIND SHIFT TO A W-NW DIRECTION ON MON AND START SPREADING CLOUDS INTO THE AREA FROM THE NORTH. MON SHOULD BE A DECENT DAY WITH MOSTLY SUNNY SKIES AND HIGHS IN THE MID-UPPER 70S (POSSIBLY 80) INLAND...MID 60S TO LOWER 70S CLOSER TO THE COAST. WINDS BECOME MORE NLY BEHIND THE WEAK FRONT MON NIGHT. MODELS HAVE BACKED OFF ON THE STRENGTH OF CAA IN THE WAKE OF THE FRONTAL PASSAGE AND CURRENTLY ANTICIPATE A MORE PESSIMISTIC FORECAST WITH INCREASED CLOUDS AND COOLER TEMPERATURES. LOWS EARLY MON NIGHT IN THE LOWER 50S. HIGHS TUE IN THE LOW 70S...MID-UPPER 60S CLOSER TO THE COAST...LOW 60S BEACHES. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS ACROSS AREA TERMINALS WILL PERSIST THROUGH THE 12Z TAF PERIOD AND BEYOND INTO EARLY NEXT WEEK. SFC HIGH PRESSURE BUILDS OVER THE AREA FROM SOUTHEAST CANADA TODAY, WITH NNE WINDS BECOMING GUSTY OVER COASTAL TERMINALS AND ALONG THE MID-ATLANTIC COAST, ESPECIALLY DURING THE LATE MORNING THROUGH MID-AFTERNOON. OUTLOOK...HIGH PRESSURE OVER SE CANADA AND THE NORTHEAST STATES WILL REMAIN IN CONTROL ACROSS THE REGION. A SERIES OF SOUTHERN STREAM DISTURBANCES WILL RIDE ALONG QUASI-STATIONARY BOUNDARY ORIENTED WELL TO THE SOUTH AND SOUTHEAST OF THE LOCAL AREA, MAINTAINING DRY WX/VFR CONDS FOR LOCAL TAF SITES THROUGH MONDAY. WINDS WILL REMAIN PREDOMINATELY FROM THE NORTH-NORTHEAST THROUGH THIS TIME FRAME. && .MARINE... FOR THE MORNING UPDATE HAVE MADE A FURTHER ADJUSTMENT TO THE SMALL CRAFT HEADLINES TO DROP SCA FOR THE LOWER CHESAPEAKE BAY ZONE AND LOWER JAMES RIVER ZONE...FOR TODAY...AS CURRENT CONDITIONS ARE WINDS AROUND 5 TO 10 KTS AND WAVES OF 1 TO 2 FT. THE SURFACE ANALYSIS SHOWS A 1035 MB AREA OF HIGH PRESSURE THAT IS CENTERED OVER EASTERN CANADA AND IS STRETCHING SOUTHWARD DOWN THE COAST THROUGH THE MID- ATLANTIC STATES INTO THE CAROLINAS. THE TIGHTER GRADIENT HAS SHIFTED OFF THE COAST KEEPING THE STRONGEST WINDS FURTHER OFF SHORE AND MORE INTO THE OUTER BANKS THAN INTO THE DELMARVA AND LOWER CHESAPEAKE BAY. LOOKING AT THE LATEST 6Z GUIDANCE, THE 11Z RUC AND OTHER HIGH RES MODELS...THE RIDGE OF HIGH PRESSURE SLOWLY SHIFTS WESTWARD INTO THE PIEDMONT LATER TONIGHT ALLOWING THE TIGHTER GRADIENT TO SHIFT MORE INTO THE LOWER CHESAPEAKE BAY SHOULD SEE WINDS AND SEAS BEGIN TO INCREASE AT THAT TIME. THUS...DROPPED SCA FLAGS FOR THOSE TWO ZONES FOR TODAY AND THIS EVENING...WITH THEM GOING BACK INTO EFFECT BEGINNING AT 1 AM EDT FRIDAY. PREV DISCUSSION... LATEST WX ANALYSIS FEATURES 1034+MB SFC HIGH PRESSURE OVER QUEBEC/NRN NEW ENGLAND, WEDGING DOWN THE LEESIDE OF THE APPALACHIANS...AS LOW PRESSURE MEANDERS OFFSHORE. RESULTANT TIGHT PRESSURE GRADIENT WILL CONTINUE TO RESULT IN STRONG ONSHORE (NNE) FLOW ON THE ORDER OF 15-25KT. NWPS/WAVEWATCH BOTH SIMILAR IN THEIR DEPICTION OF SIG WAVE HEIGHTS IN THE 5-8FT RANGE...8-10 FT IN SRN COASTAL WATERS BY FRI NIGHT. PER LATEST OBS AND HI-RES MODEL DEPICTION, HAVE DROPPED SCA FLAGS OVER THE MIDDLE BAY ZONE. WINDS WILL REMAIN IN THE 10-15KT RANGE, AND WHILE OCCASIONAL GUSTS TO LOW END SCA ARE EXPECTED IN THE NORTHERN/MIDDLE CHES BAY, PREDOMINATE CONDITIONS WILL REMAIN SUB-SCA NORTH OF NEW POINT COMFORT. FARTHER SOUTH, SCA FLAGS CONTINUE THROUGH FRI FOR THE LOWER CHES BAY (SOUTH OF NEW PT COMFORT) AND THE LOWER JAMES RIVER, AND THROUGH FRI NIGHT/EARLY SATURDAY FOR THE ATLANTIC COASTAL WATERS...CURRITUCK SOUND...AND THE MOUTH OF THE CHES BAY. A LOW PRESSURE SYSTEM DIVES SWD WELL OFF THE COAST...CREATING A STRONGER SURGE OF NNE WINDS, QUITE POSSIBLY OVER ALL ZONES FRIDAY AND FRIDAY NIGHT. ONSHORE WINDS/NE SWELL PERSIST THROUGH MUCH OF THE WEEKEND INTO SUN NIGHT...WITH SEAS WILL REMAIN RELATIVELY UNCHANGED WITH WAVE HEIGHTS OF 7-10FT SAT/SAT NIGHT. COOL AIR WEDGE FINALLY BEGINS TO BREAK BY LATE IN THE WEEKEND AS THE HIGH SLIDES OVERHEAD AS THE OFFSHORE LOW GETS SHUNTED FARTHER OFFSHORE. SEAS WILL LIKELY TAKE SOME TIME TO SUBSIDE BELOW 5 FT SCA THRESHOLD, LIKELY TAKING INTO MONDAY/MONDAY NIGHT, ESPECIALLY OVER SOUTHERN WATERS. A SFC LOW TRACKS ALONG THE US/SE CANADIAN BORDER MONDAY, AND GETS PUSHED DOWN ACROSS NRN NEW ENGLAND MON/MON NGT. THIS SYSTEM DRAGS A BACKDOOR FRONT SOUTH INTO THE NORTHEAST DURING THIS PERIOD, WITH THIS FRONT DROPPING ACROSS THE WATERS EARLY TUESDAY. THIS SHOULD RESULT IN A WIND SHIFT TO A W-NW DIRECTION MON NGT...BECOMING MORE NLY BEHIND THE WEAK FRONT TUE. MODELS HAVE BACKED OFF ON THE STRENGTH OF CAA IN THE WAKE OF THIS FRONTAL PASSAGE AND WOULD CONTINUE TO EXPECT A SUB-SCA PUSH IN WIND SPEEDS AOB 15KT DURING THIS TIME FRAME. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ634-650- 652-654-656-658. SMALL CRAFT ADVISORY FROM 1 AM TO 6 PM EDT FRIDAY FOR ANZ632- 638. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT FRIDAY NIGHT FOR ANZ633. && $$ SYNOPSIS...MAS NEAR TERM...MAS SHORT TERM...MAS/MPR LONG TERM...BMD AVIATION...MAM MARINE...ESS/MAM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
530 AM CDT THU APR 14 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 440 AM CDT THU APR 14 2016 WARM FRONT THAT REMAINED WELL DEFINED THROUGH THE DAY YESTERDAY AND THROUGH MUCH OF LAST NIGH WAS FINALLY STARTING TO BECOME LESS DEFINED IN THE WIND FIELD...THOUGH WAS STILL IDENTIFIABLE ACROSS CENTRAL MN. SOUTH OF THIS BOUNDARY...TEMPERATURES OVERNIGHT HAVE MOSTLY REMAINED ABOVE 50. AS WE GO THROUGH THE DAY...A 995 MB LOW WILL DEVELOP NEAR THE ND/SD/WY/MT REGION...WHICH PUT A MORE SRLY PRESSURE GRADIENT ACROSS THE AREA AND FINALLY FORCE WHAT IS LEFT OF THE WARM FRONT UP INTO NRN MN. THIS STRENGTHENING SRLY FLOW WILL ADVECT A LOW LEVEL THERMAL RIDGE INTO WRN MN ALONG ROUGHLY AN ABERDEEN TO BEMIDJI LINE. WITHIN THIS THERMAL RIDGE...WE REMAIN CONFIDENT IN HIGHS REACHING TO THE LOW 80S WEST OF A GRANITE FALLS TO STAPLES LINE. IN ADDITION...BASED ON A RAP/GFS MIXED LAYER DEWPOINTS...THIS PORTION OF WESTERN MN LOOKS TO GET CAUGHT BETWEEN AREAS OF SLIGHTLY HIGHER DEWPOINTS TO THEIR NORTH /NORTH OF THE WARM FRONT/ AND TO THE EAST AS AIR WITH SFC DEWPOINTS CURRENTLY IN THE MID 40S IN ERN NEB LOOKS TO GET ADVECTED UP TOWARD THE TWIN CITIES TODAY. THESE SLIGHTLY LOWER DEWPOINTS COINCIDING WITH HIGHS IN THE LOW 80S RESULTED IN A FAIRLY BROAD AREA WHERE MINIMUM HUMIDITIES ARE FORECAST TO GET DOWN BETWEEN 20 AND 25 PERCENT. INCIDENTALLY...THIS IS ALSO WHERE THE SPC INCLUDED AN ELEVATED AREA ON THE DAY 1 FIRE WEATHER RISK MAP...SO AFTER COORDINATION WITH MIFC ALONG WITH ABR/FSD/FGF...WE ENDED UP WITH THE RFW SEEN FROM 18Z THROUGH 00Z THIS AFTERNOON. FOR THE REST OF MN...WE HAVE HUMIDITY VALUES FORECAST TO GET DOWN TO BETWEEN 25 AND 35 PERCENT WITH SUSTAINED WINDS MORE 15 TO 25 MPH WITH GUSTS TO 30 MPH. THEREFORE OUTSIDE OF THE WARNING...AFTER COORDINATION WITH ARX/DLH...WILL HAVE A SPECIAL WEATHER STATEMENT FOR THE INCREASED FIRE DANGER ACROSS THE REST THE MPX MN COUNTIES. MAIN AREA OF LOWER CONFIDENCE TODAY IS WITH THE DEWPOINT FORECAST AND ATTENDANT HUMIDITY LEVELS. CURRENT FORECAST IS CERTAINLY ON THE LOW END OF THE DEWPOINT ENVELOP...BUT IN LINE WITH WHAT THE HRRR AND HOPWRF ARE SHOWING. IF THERE IS AN AREA THIS FORECAST GOOD BE A BUST IT IS WITH THE LOW HUMIDITY. HOWEVER...OVER THE LAST WEEK...WE HAVE HAD A COOL TEMPERATURE AND MOIST RH BIAS...SO FEEL CONFIDENT IN THE CURRENT SCENARIO DEPICTED IN THE GRIDS. FOR TONIGHT...IT WILL BE ANOTHER MILD NIGHT...WITH LOWS SIMILAR TO WHAT WE HAVE SEEN TO SOUTH OF THE WARM FRONT OVERNIGHT...UPPER 40S TO LOWER 50S THANKS TO SRLY WINDS CONTINUING TO BLOW. IN ADDITION...THE STRENGTHENING OF THE UPPER RIDGE OVER THE GREAT LAKES WILL HELP PUSH ANY CLOUDS/PRECIP EVEN FARTHER WEST OF WHAT WE WILL SEE TODAY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 440 AM CDT THU APR 14 2016 IT MAY BE TORNADO TEST DAY IN MN/WI...BUT THE WARM AND DRY WEATHER IS HERE TO STAY THROUGH SATURDAY GIVEN THE OMEGA BLOCK IN THE ATLANTIC. THE BLOCKING PATTERN IS KEEPING THE NE CONUS/EASTERN CANADIAN TROUGH IN PLACE...AND FARTHER UPSTREAM THE RIDGING IN PLACE ACROSS THE LOCAL AREA. HIGH TEMPERATURES IN THE 70S WILL BE THE RESULT LOCALLY FRI- SAT. A TROUGH MOVES INLAND OVER THE PACIFIC NORTHWEST TODAY...BUT DROPS ACROSS THE SOUTHWEST CONUS AND BECOMES CUTOFF FROM THE MAIN FLOW - THE 14.00Z GFS AND ECMWF CONTINUE TO KEEP THE UPPER LOW SPINNING AWAY DOWN ACROSS THE SOUTHWEST THROUGH EARLY NEXT WEEK BEFORE EVENTUALLY FILLING AND SHEARING OUT. THE SURFACE TROUGH AND COLD FRONT ASSOCIATED WITH THIS FEATURE WILL REMAIN IN THE DAKOTAS THROUGH FRIDAY...BUT THE LATEST GUIDANCE DOES TRY TO BRING THE BOUNDARY INTO THE FAR WESTERN FORECAST AREA ON SATURDAY...AND KEEPS IT THERE UNTIL SUNDAY...BEFORE SAGGING IT E-SE SUNDAY NIGHT INTO MONDAY. A FEW SHOWERS ARE POSSIBLE ON SATURDAY IN FAR WESTERN MINNESOTA DUE TO THE PRESENCE OF THIS BOUNDARY. THE REST OF THE FORECAST AREA COULD SEE RAIN SUNDAY AFTERNOON - SUNDAY NIGHT WHEN THIS BOUNDARY IS DRIVEN SOUTH BY A SHORTWAVE COMING OUT OF CANADA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 530 AM CDT THU APR 14 2016 OUTSIDE OF SOME SCT CLOUDS BETWEEN 7K AND 10K FEET THROUGH THE MORNING FROM SOUTHERN INTO EASTERN MN AND WRN WI...IT WILL BE AN SKC TAF PERIOD WITH BREEZY SOUTH WINDS AS HAS BEEN ADVERTISED IN THE GUIDANCE AND OUR TAFS TO THIS POINT...SO FEW CHANGES WERE NEEDED. KMSP...IS SOME MARGINAL WIND SHEAR THIS MORNING THAT WILL START TO SUBSIDE AFTER 14Z AS WINDS VEER AND INCREASE IN SPEED...THUS REDUCING SHEAR. OTHERWISE ITS A HIGH CONFIDENCE KIND OF TAF. /OUTLOOK FOR KMSP/ FRI...VFR. WINDS SSE 10-20 KTS. SAT...VFR. WINDS S 10-15 KTS. SUN...MVFR CIG POSSIBLE. WINDS SW BCMG NW 5 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR MNZ041-042-047>049-054>057-064. && $$ SHORT TERM...MPG LONG TERM...CLF AVIATION...MPG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
634 AM CDT THU APR 14 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 455 AM CDT THU APR 14 2016 ALTHOUGH THE MAJORITY OF THESE NEXT 24 HOURS SHOULD REMAIN RAIN- FREE (ESPECIALLY THROUGH MIDNIGHT) AND ALSO BREEZY TO WINDY...THERE ARE 2 MAIN FORECAST ISSUES TO CONTEND WITH: 1) IN THE VERY NEAR TERM...ALTHOUGH IT IS BECOMING INCREASINGLY- OBVIOUS FROM SATELLITE TRENDS THAT MUCH OF THE SOUTHERN TWO-THIRDS (IF NOT MORE) OF THE CWA WILL START THE DAY WITH AT LEAST A FEW HOURS OF CLOUDY/MOSTLY CLOUDY SKIES UNDER A DECK OF LOW STRATUS CLOUDS...THE JURY IS STILL VERY MUCH ON OUT REGARDING WHETHER OR NOT FOG REMAINS NOTHING MORE THAN A LIGHT NUISANCE...OR ACTUALLY ENDS UP BECOMING THICKER/MORE DENSE ON AT LEAST A LOCALIZED BASIS. 2) LATE TONIGHT (MAINLY AFTER 1 AM)...WILL MAINTAIN LOW (20-30 PERCENT) PRECIP CHANCES/POPS FOR SHOWERS AND ISOLATED WEAK THUNDERSTORMS ACROSS MOST OF THE CWA...AND ACTUALLY NUDGED THESE LOW RAIN CHANCES A BIT FARTHER EAST CLOSER TO THE HIGHWAY 14 CORRIDOR. STARTING WITH THE HERE-AND-NOW AS OF 09Z/4AM..."NUMBER 1" ABOVE IS CLEARLY THE ONGOING FORECAST HEADACHE REGARDING LOW STRATUS/POSSIBLE FOG TRENDS OVER THE NEXT 6 HOURS OR SO. AS IS OFTEN THE CASE...SOME MODELS/SETS OF GUIDANCE ARE PERFORMING FAR BETTER THAN OTHERS AT CAPTURING THE NORTHWARD DEVELOPMENT OF LOW STRATUS OUT OF CENTRAL KS INTO OUR CWA...AND EVEN SOME THAT DO ACKNOWLEDGE ITS DEVELOPMENT ARE STILL NOTICEABLY TOO HIGH WITH THE CLOUD CEILING. AS OF THIS WRITING...THIS AREA OF LOW STRATUS (WITH A HEIGHT OF ONLY AROUND 600 FT) HAS INFILTRATED MUCH OF OUR KS ZONES...AND IS EXPECTED TO CONTINUE MAKING STEADY PROGRESS NORTH OF THE STATE LINE BETWEEN NOW AND SUNRISE. MEANWHILE...CLEAR SKIES AT LEAST TEMPORARILY CONTINUE TO RULE THE NEBRASKA CWA. IN THE BIG PICTURE OF THE MID-UPPER LEVELS...VERY WEAK/BENIGN FLOW PERSISTS OVER THE LOCAL AREA UNDER THE LINGERING INFLUENCE OF A BROAD RIDGE...WITH THE LOCAL AREA WELL TO THE NORTHWEST OF A VERY SLOW MOVING LOW CENTERED OVER THE MO/OK/AR BORDER AREA...AND STILL WELL TO THE EAST OF THE WELL-ADVERTISED LARGE-SCALE LOW MOVING INTO THE WESTERN CONUS THAT WILL PROVIDE THE MULTIPLE RAIN CHANCES OUTLINED IN THE LONG TERM SECTION BELOW. AT THE SURFACE...A MODEST PRESSURE GRADIENT PERSISTS BETWEEN A ROUGHLY 1006 MILLIBAR LOW CENTERED OVER SD AND HIGH PRESSURE SPRAWLED OUT OVER THE EASTERN CONUS. AS A RESULT...BREEZES ARE CURRENTLY SOUTHERLY AT GENERALLY 7-12 MPH ACROSS MOST OF THE CWA. OVERNIGHT LOW TEMPERATURES ARE ON TRACK TO BOTTOM OUT GENERALLY 47-50...WHICH IS ROUGHLY 10 DEGREES ABOVE AVERAGE. NOW LOOKING AHEAD FORECAST-WISE THROUGH SUNRISE FRIDAY MORNING: EARLY THIS MORNING (THROUGH ROUGHLY SUNRISE): ALL EYES ARE ON THE NORTHWARD-MOVING LOW STRATUS EVIDENT ON SATELLITE IMAGERY AS IT CONTINUES PUSHING OUT OF KS INTO NEB ZONES. FOLLOWING THE USUAL MOST-RELIABLE VERY NEAR-TERM SOLUTIONS OF THE RAP13 AND HRRR MODELS...THESE LOW CLOUDS SHOULD MAKE IT UP TO ROUGHLY THE I-80 CORRIDOR IF NOT A BIT FARTHER NORTH BY 12Z/7AM. ALTHOUGH SOME VERY LIGHT FOG IS PROBABLE ESPECIALLY NEAR THE LEADING EDGES OF THIS CLOUD MASS...THE BIG QUESTION IS WHETHER OR NOT ANY FOG COULD BECOME MORE DENSE. THE LATEST HRRR/RAP13 VISIBILITY PROGS STILL SHOW THIS COULD BE POSSIBLE ON AT LEAST A LOCALIZED BASIS...BUT WOULD TEND TO THINK THAT THE LIGHT-BUT- STEADY SOUTHERLY BREEZES SHOULD HELP MITIGATE TRULY IMPACTFUL FOG PROBLEMS. WILL CONTINUE TO CARRY A MIX OF "PATCHY" AND "AREAS" OF FOG IN FORECAST PRODUCTS...BUT WILL REFRAIN FROM SPECIFYING ANY PRONOUNCED VISIBILITY REDUCTIONS UNLESS/UNTIL THEY SHOW THEIR HAND. TODAY (SUNRISE THROUGH SUNSET): IN SHORT...ANOTHER DRY AND SEASONABLY WARM DAY THAT IF ANYTHING SHOULD AVERAGE ROUGHLY 5 MPH WINDIER THAN YESTERDAY. PROBABLY THE BIGGEST UNCERTAINTY LIES WITH EXACTLY WHEN THE ONGOING/INCOMING LOW STRATUS CLOUDS BURN OFF/DISSIPATE. AGAIN FOLLOWING THE RAP/HRRR SOLUTIONS MORE CLOSELY THAN ANYTHING (INCLUDING LOW LEVEL CLOUD PRODUCTS AND 925/900 MILLIBAR RH)...FAIRLY EXPANSIVE LOW CLOUDS SHOULD REACH UP TO AROUND HIGHWAY 92 AND POSSIBLY EVEN A BIT FARTHER BY THE 7-9 AM TIME FRAME...BEFORE A STEADY EROSION/DISSIPATION GETS UNDERWAY BY 10 AM WITH MAYBE ONLY A LITTLE LINGERING STRATUS IN FAR WESTERN ZONES BY ROUGHLY 11 AM AND THEN MOSTLY SUNNY SKIES CWA-WIDE BY NOON AT THE LATEST. AT LEAST THAT`S THE GENERAL EXPECTATION...AGAIN FOR A CLOUDY/MOSTLY CLOUDY MORNING GIVING WAY TO A MOSTLY SUNNY AFTERNOON. AS FOR FOG POTENTIAL...SEE PREVIOUS EARLY MORNING PARAGRAPH FOR REASONING HERE. IN SHORT...WILL CONTINUE AT LEAST A BASIC FOG MENTION ACROSS THE ENTIRE CWA THROUGH 10 AM BUT AGAIN REALLY NOT EXPECTING ANYTHING DENSE/IMPACTFUL AT THIS TIME. AT LEAST INITIALLY...THE LOW STRATUS AND SHALLOW MIXING SHOULD KEEP MORNING SOUTHERLY WIND SPEEDS MAINLY AROUND 15 MPH OR LESS. HOWEVER...AND AGAIN ASSUMING WIDESPREAD AFTERNOON SUN BREAKS OUT AS EXPECTED...DEEPENING MIXING AND A TIGHTENING SURFACE PRESSURE GRADIENT THANKS TO PRONOUNCED HIGH PLAINS PRESSURE FALLS SHOULD LEAD TO A BREEZY/WINDY AFTERNOON WITH SUSTAINED SOUTH-SOUTHEAST SPEEDS GENERALLY 15-25 MPH AND GUSTS 25-35 MPH. TEMP-WISE...AND YET AGAIN ASSUMING PLENTIFUL AFTERNOON SUN...MADE LITTLE CHANGE TO PREVIOUS FORECAST AND KEPT TOWARD THE WARMER END OF MODEL SOLUTIONS...AIMING MOST OF THE CWA 74-77. FORTUNATELY FOR POTENTIAL FIRE WEATHER CONCERNS...EVEN MID- AFTERNOON DEWPOINTS SHOULD BE WELL INTO THE 40S...THUS KEEPING RH PERCENTAGES INTO THE 30S AND SAFELY ABOVE "NEAR-CRITICAL" LEVELS. THIS EVENING/TONIGHT: ALTHOUGH AREAS OF LOW STRATUS CLOUDS COULD AGAIN OVERTAKE MAINLY WESTERN PORTIONS OF THE CWA...THE ENTIRE AREA SHOULD SEE A GRADUAL WEST-TO-EAST INCREASE IN AT LEAST MID-HIGH LEVEL CLOUDS ALONG WITH THE AFOREMENTIONED FAIRLY LOW BUT NON-ZERO CHANCES FOR LATE NIGHT SHOWERS/WEAK THUNDERSTORMS. IN THE MID-UPPER LEVELS...NOTICEABLY STRONGER SOUTHWESTERLY FLOW WILL QUICKLY REPLACE THE CURRENT WEAK/"RIDGY" REGIME...AS THE LEADING EDGES OF FORCING ASSOCIATED WITH THE LARGE WESTERN TROUGH REACHES THE CENTRAL PLAINS. AS THIS OCCURS...FAIRLY SUBTLE SHORTWAVE TROUGHS EJECTING INTO THE PLAINS WILL INTERACT WITH A FAIRLY STOUT 50+ KT SOUTHERLY LOW-LEVEL JET EVIDENT AT 850MB TO KICK OFF AT LEAST ISOLATED SHOWERS/WEAK THUNDERSTORMS. KEPT THE PRE-06Z/EVENING HOURS PRECIP-FREE AS ANY CONVECTION SHOULD REMAIN OFF TO OUR WEST IN THE NEB PANHANDLE AND VICINITY. THEN LATE IN THE NIGHT...THE LOW CONVECTIVE CHANCES SHOULD PUSH EASTWARD INTO ALL BUT MAYBE THE FAR EASTERN ZONES. ALTHOUGH THE INITIAL SPC DAY 1 "GENERAL THUNDER" AREA ONLY CLIPS THE EXTREME WESTERN EDGE OF THE CWA...OPTED TO MAINTAIN A GENERIC "ISOLATED THUNDER" WORDING IN THE FORECAST FOR MOST OF THE CWA...AS NAM SOUNDINGS SUGGEST UP TO A FEW HUNDRED J/KG OF MOST- UNSTABLE CAPE...MAKING IT VERY HARD TO RULE OUT A FEW ROGUE LIGHTNING STRIKES. HOWEVER...THESE SHOULD BE RATHER WEAK STORMS AND EVEN PEA-SIZE HAIL MAY BE HARD TO COME BY. OTHERWISE TONIGHT...A TIGHTER PRESSURE GRADIENT COMPARED TO THIS MORNING WILL MAINTAIN STEADY SOUTH-SOUTHEAST BREEZES OF GENERALLY 15-20 MPH FOR MOST OF THE NIGHT. THESE BREEZES...IN TANDEM WITH INCREASING CLOUDS...SHOULD KEEP LOW TEMPS A FEW DEGREES WARMER THAN THIS MORNING...AND MADE LITTLE CHANGE HERE WITH A GENERAL RANGE OF 51-54. .LONG TERM...(FRIDAY DAYTIME THROUGH WEDNESDAY) ISSUED AT 455 AM CDT THU APR 14 2016 BIGGEST CHALLENGE WILL BE DETERMINING CHANCES OF RAIN. THE LONG AWAITED DEVELOPING TROUGH AND UPPER CLOSED ARRIVE IN THE GREAT BASIN/WESTERN SLOPES OF THE ROCKIES FRIDAY/FRIDAY NIGHT. ALONG WITH A STRONG UPPER RIDGE IN THE EASTERN HALF OF THE CWA. THIS RIDGE IN THE EAST WILL PUT THE BRAKES ON MUCH EASTWARD PROGRESSION OF THE TROUGH/LOW. TRENDS CONTINUALLY POINT TOWARD A SLOWED PROGRESSION EAST OF THE TROUGH...WHICH WILL TAMP DOWN ON POPS BEING VERY HIGH...BUT THEY WILL BE A HIGHER IN OUR WEST. ALSO...I SUSPECT THAT FRIDAY HAS POTENTIAL FOR BEING WARMER THAN WHAT MOST MODELS ARE ADVERTISING. I TEND TO LIKE THE WARM GUIDANCE FROM THE BIAS CORRECTED ECMWF AS THIS MODEL SEEMS TO HAVE GENERALLY OUTPERFORMED MOST NUMERICAL MODELS WHEN POTENTIAL FOR SIGNIFICANTLY WARMER THAN AVERAGE TEMPERATURES ARE EXPECTED. AND IN THIS CASE...THE SURFACE COLD FRONT SHOULD LURK WELL WEST OF THE CWA IN WESTERN NEBRASKA FOR FRIDAY...WHICH WILL LEND TO A MUCH ABOVE NORMAL DAY. IF WE HAPPEN TO GET A SOLID CIRRUS SHIELD...THEN OUR TEMPERATURES WILL BE COOLER THAN WHAT I ADVERTISE...BUT FOR NOW I SIDE WITH THE WARMER FORECAST. LIKEWISE...I WENT WARMER FOR FRIDAY NIGHT LOWS AND WENT TOWARD CONSRAW FOR LOWS AS WE REMAIN EAST OF THE COLD FRONT AND SKY COVER INCREASES QUITE A BIT. THE SAME GOES FOR SATURDAY NIGHT AND I FOLLOWED CONSRAW FOR LOWS...BUT NOT QUITE AS WARM AS FRIDAY NIGHT. SUPERBLEND SUFFICES FOR TEMPS FOR THE MOST PART BEYOND THIS. FOR POPS...I DECREASED THEM COMPARED TO WHAT SUPERBLEND IS ADVERTISING. ALSO...I AM NOT CONFIDENT ENOUGH TO GO ANY HIGHER THAN 70 POPS...EVEN IN OUR WEST AT ANY POINT. WITH THE STRONG RIDGE IN THE EAST...ALONG WITH THE WEAKENING CLOSED LOW TO THE WEST...THE CONFIDENCE IS JUST NOT THERE YET. IF THE LOW TAKES TOO LONG TO GET HERE...THE FACT THAT IT WILL PROBABLY WEAKEN WILL DECREASE OUR CHANCES OF PRECIP OVERALL. THE LOW MAY NOT EVEN MAKE IT INTO THE CENTRAL PLAINS UNTIL MID WORK WEEK. AGAIN...CONFIDENCE IS LOW...BUT THE BEST CHANCES OF RAIN REMAIN IN OUR WEST. UNTIL THE LOW CLEARS THE AREA...WE WILL HAVE CONTINUED CHANCES OF RAIN. I LEFT AT LEAST ISOLATED THUNDER IN FOR THE LONG TERM AS THERE WILL BE ENOUGH INSTABILITY FOR THIS...AND IT IS FRANKLY DIFFICULT TO NOT GET THUNDER WITH CONVECTION WHEN WE GET INTO THIS TIME OF YEAR AND BEYOND. THE SPC SWIPES OUR FAR WEST WITH MARGINAL SEVERE FOR FRIDAY...BUT I WILL HOLD OFF ON THIS AS TRENDS ARE FOR THE COLD FRONT BEING FARTHER WEST. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 634 AM CDT THU APR 14 2016 ALTHOUGH THE MAJORITY OF THE PERIOD IS STILL EXPECTED TO FEATURE VFR CEILING/VISIBILITY...THERE ARE TWO WINDOWS OF OPPORTUNITY FOR SUB-VFR...ONE RIGHT AWAY/ONGOING THIS MORNING AND ANOTHER LATE TONIGHT. LATE TONIGHT...THERE IS ALSO A LOW CHANCE FOR RAIN SHOWER/WEAK THUNDERSTORM ACTIVITY...AND THIS HAS BEEN COVERED WITH A GENERIC "VICINITY SHOWER" (VCSH) MENTION. CEILING/VISIBILITY: IFR/LIFR CONDITIONS HAVE IN FACT MOVED UP FROM THE SOUTH THIS MORNING...WITH THINGS AS BAD IF NOT WORSE THAN EXPECTED 6 HOURS AGO. FORTUNATELY...THESE VERY LOW CEILINGS AND VARIABLE VISIBILITY IN FOG ARE ONLY EXPECTED TO LAST ROUGHLY 3 HOURS OR SO BEFORE DISSIPATING/SCOURING OUT BUT THIS TIMING WILL NEED WATCHED CLOSELY. ONCE THE MORNING GRUNGE CLEARS...MOST OF THE DAY/NIGHT SHOULD REMAIN VFR. HOWEVER...VERY LATE IN THE PERIOD A RETURN TO AT LEAST MVFR (POSSIBLY WORSE) CONDITIONS ARE POSSIBLE BUT UNCERTAINTY IS HIGH. WINDS: A SOUTHERLY DIRECTION WILL PREVAIL THROUGHOUT THE PERIOD. WHILE SUSTAINED SPEEDS SHOULD LARGELY AVERAGE BELOW 12KT INITIALLY THIS MORNING...SPEEDS WILL STEADILY PICK UP BY LATE MORNING AS SKIES CLEAR WITH GUST POTENTIAL UP TO AROUND 27KT WITH SIMILAR SPEEDS THEN PERSISTING THROUGH THE NIGHT ALTHOUGH LIKELY NOT QUITE AS GUSTY AT TIMES. THERE ARE HINTS THAT LOW LEVEL WIND SHEAR (LLWS) COULD APPROACH/REACH MENTIONABLE LEVELS LATE TONIGHT...BUT GIVEN THIS IS WELL-BEYOND THE FIRST 12 HOURS WILL DEFER TO LATER SHIFTS TO EXAMINE AND POSSIBLY INTRODUCE AS IT GETS CLOSER. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...HEINLEIN AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
956 AM CDT THU APR 14 2016 .UPDATE... ISSUED AT 941 AM CDT THU APR 14 2016 UPDATE IS TO EXPAND RED FLAG HEADLINES INTO EASTERN SOUTH DAKOTA. A PLUME OF HIGHER DEW POINT AIR IS HEADED IN FROM THE SOUTH TODAY...HOWEVER BEFORE IT ARRIVES BOTH THE 12Z NAM AND 06Z GFS SUGGEST THAT THERE IS A POCKET OF MUCH DRIER AIR LOCATED AROUND 850-750MB...CO LOCATED WITH THE CORE OF WARMEST AIR. AS THIS MIXES OUT...HRRR AND RUC DEW POINTS DROP TO THE UPPER 30S/LOW 40S. THUS...WITH A SLIGHT NUDGE OF HIGHS INTO THE LOW 80S FOR THE COTEAU...AFTERNOON RH VALUES COULD DROP DOWN TO CRITERIA. THE WIND FORECAST REMAINS THE SAME WITH GUSTS TO AROUND 30MPH. NO OTHER CHANGES FOR THIS MORNING UPDATE. && .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 403 AM CDT THU APR 14 2016 FIRE WEATHER CONCERNS TODAY...AND PCPN CHANCES THROUGHOUT THE PERIOD WILL BE THE FORECAST CHALLENGES. A WEAK SURFACE TROUGH AND UPPER LEVEL SHORTWAVE IS CURRENTLY LIFTING NORTHEASTWARD ACROSS THE WESTERN DAKOTAS. THIS SYSTEM IS PRODUCING LIGHT PCPN...MAINLY ACROSS NORTH DAKOTA. WHILE THE UPPER LEVEL LIFT WILL DEPART THE REGION TODAY...A STALLED FRONTAL BOUNDARY MAY BECOME THE FOCUS FOR ADDITIONAL PCPN CHANCES THIS AFTERNOON IN NORTH CENTRAL SD. AS FOR FIRE WEATHER...MOST OF THE CWA WILL SEE VERY WARM TEMPERATURES WITH HIGHS REACHING THE LOW 80S. A STRENGTHENING LOW PRESSURE SYSTEM WEST OF THE REGION WILL PRODUCE GUSTY SOUTHERLY WINDS FOR THE EASTERN HALF OF THE CWA. WHILE WINDS SUPPORT A FIRE WEATHER HEADLINE...INCREASING MOISTURE FROM THE SOUTH COULD KEEP RH VALUES FROM FALLING BELOW 25 PERCENT. WILL FORGO ISSUING A FIRE WEATHER HEADLINE FOR SD...BUT WILL ISSUE ONE FOR OUR MINNESOTA COUNTIES. AN UPPER LEVEL CLOSED LOW AT 500 MB CURRENTLY IMPACTING THE PAC NW...WILL BE OUR NEXT WEATHER SYSTEM. THIS SYSTEM WILL BECOME A DEEP TROUGH OVER THE WESTERN HALF OF THE US...WHICH WILL PRODUCE DECENT SOUTHERLY FLOW OF MOISTURE INTO THE NORTHERN PLAINS. INTEGRATEDWATER VAPOR TRANSPORT IN NOT REAL GREAT WITH THE FIRST WAVE OF PCPN TONIGHT THROUGH FRIDAY. GENERALLY EXPECTING LIGHT TO MODERATE SHOWERS WITH SOME THUNDERSTORMS. THE INTEGRATED WATER VAPOR TRANSPORT IS BEST FRIDAY NIGHT INTO SATURDAY MORNING WHEN THE GULF OF MEXICO COULD BE OPEN. THIS TIME PERIOD IS WHEN THE SREF INDICATES THE BEST POTENTIAL OF SEEING 0.25 INCHES OF QPF IN A 6 HOUR PERIOD. THANKFULLY A GOOD 1 TO 3 INCHES OF RAINFALL OVER THE COURSE OF A COUPLE OF DAYS IS NEEDED. .LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY) ISSUED AT 403 AM CDT THU APR 14 2016 NOT MUCH CHANGE FROM THE PREVIOUS FORECAST IN THE EXTENDED. A DEEP UPPER TROUGH WILL TRANSITION INTO A CUTOFF LOW BY SUNDAY/MONDAY. GFS AND ECMWF DIFFER SLIGHTLY IN PLACEMENT OF THE UPPER LOW WITH THE GFS A LITTLE FARTHER NORTH. THIS DISCREPANCY WILL IMPACT TIMING OF PRECIP EXIT. SFC HIGH PRESSURE WILL MOVE DOWN FROM THE NORTH BRINGING IN MUCH DRIER AIR WHICH WILL SET UP A SHARP GRADIENT OF RAIN/NO RAIN. BY TUESDAY NIGHT RIDGING ALOFT WILL TAKE HOLD AND ALL PRECIP WILL EXIT. TEMPS WILL TREND UPWARD THROUGH THE PERIOD WITH HIGHS IN THE 50S ON SUNDAY UNDER THE UPPER TROUGH CLIMBING TOWARD 70 BY WED AS THE RIDGE BUILDS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 625 AM CDT THU APR 14 2016 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL INCREASE TO 15 TO 30 KTS OUT OF THE SOUTH TO SOUTHEAST TODAY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR SDZ272-273. MN...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING FOR MNZ039-046. && $$ UPDATE...CONNELLY SHORT TERM...SD LONG TERM...WISE AVIATION...WISE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
930 AM CDT THU APR 14 2016 .UPDATE... FOR MORNING DISCUSSION. && .DISCUSSION... SURFACE OBS THIS MORNING SHOW AN INVERTED TROUGH IN PLACE ACROSS MIDDLE TENNESSEE WITH SOUTHEAST WINDS AND DEWPOINTS IN THE UPPER 40S/50S ACROSS SOUTHEAST ZONES VERSUS NORTHEAST WINDS AND MUCH LOWER DEWPOINTS IN THE FAR NORTHWEST. RADAR SHOWS SCATTERED SHOWERS CONTINUED OVER THE SOUTHEAST TWO-THIRDS OF THE CWA...AND MODELS INCLUDING THE HRRR AND NAM SHOW AN INCREASE IN SHOWER ACTIVITY THIS AFTERNOON AREAWIDE. HAVE ADJUSTED POPS/TEMPS SLIGHTLY BASED ON LATEST OBS AND TRENDS. CANNOT RULE OUT AN ISOLATED THUNDERSTORM TODAY OVER WESTERN ZONES...BUT BETTER CHANCE FOR STORMS WILL BE WEST OF OUR FORECAST AREA CLOSER TO CENTER OF UPPER LOW. && .AVIATION... 12Z TAF DISCUSSION. UPPER LOW AND AN INVERTED SURFACE BOUNDARY ARE EXPECTED TO SET UP ACROSS THE REGION TODAY. WITH ABUNDANT MEAN MOISTURE ALREADY IN PLACE...SCATTERED SHOWERS AND MAYBE A FEW TSTORMS ARE LIKELY...ESPECIALLY CKV/BNA. THIS MAY BRING CIGS/VSBYS DOWN INTO MVFR LEVELS LATER TODAY INTO THE EVENING. PRECIPITATION EXPECTED TO BE MORE ISOLATED LATER TONIGHT AND CONDITIONS LIKELY TO LARGELY VFR...ALTHOUGH SOME LIGHT FOG MAY DEVELOP TOWARD 12Z. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ AVIATION.........................01/BOYD SHORT/LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
620 AM CDT THU APR 14 2016 .DISCUSSION...PLEASE SEE 12Z AVIATION DISCUSSION BELOW. CONCERNING DENSE FOG...EXPANDED DENSE FOG ADV FOR NORTHERN COASTAL BEND AS VSBYS CONTINUE TO LOWER THERE. ALSO ADDED WEBB AND DUVAL COUNTY TO ADVISORY. 11 TO 3.9 MICROMETER SATELLITE IMAGERY INDICATES FOG DEVELOPING ACROSS NORTHERN HALVES OF WEBB/DUVAL COUNTIES AND SLOWLY SPREADING SOUTH. FOG MAY NOT MAKE IT INTO CITY OF LAREDO...BUT IT WILL BE CLOSE. /HART/. && .AVIATION...POOR FLIGHT RULES EARLY THIS MRNG WITH RAPID IMPROVEMENT TO VFR AROUND MID MRNG. AS OF WRITING....AREAS OF FOG CONTINUE TO DVLP ACROSS S TX WITH VLIFR CONDITIONS XPCTD AT BEGINNING OF TAF PERIOD AT KVCT...WITH FOG POSSIBLY DVLPNG INTO KLRD SHORTLY AFTER 12Z. CONFIDENCE IS NOT MAJORLY HIGH WITH FG IMPACTING KLRD...BUT HIGH ENOUGH TO INCLUDE IN TAFS. KCRP MAY EXPERIENCE PATCHES OF IFR CIGS THRU MID MRNG...WITH KALI FLIRTING WITH UPPER END IFR/LOW END MVFR VSBYS. ALL TERMINALS SHOULD RETURN TO VFR WITH MAINLY CLEAR SKIES BY MID/LATE MRNG WITH VFR THEN PREVAILING THE REST OF TODAY. ADDITIONAL FG/CIGS/POOR FLIGHT RULES POSSIBLE AT KVCT/KLRD/KALI LATE TONIGHT. LIGHT NRLY SFC WINDS AROUND 10 KTS GRADUALLY BECMG ESERLY BY LATE IN THE DAY. && .PREV DISCUSSION... /ISSUED 533 AM CDT THU APR 14 2016/ DISCUSSION...AFTER COLLABORATING WITH EWX...DECIDED TO ISSUE A DENSE FOG ADVISORY FOR AREAS FROM LA SALLE COUNTY EASTWARD TO VICTORIA COUNTY. VISIBILITIES PREVAILING AT 1/4 MILE AT KVCT WITH MILITARY SITES ACROSS RURAL AREAS OF MCMULLEN COUNTY ALSO REPORTING DENSE FOG. SREF...NARRE-TL...AND HRRR RUNS INDICATE DENSE FOG EXPANDING IN AREAL COVERAGE THROUGH SUNRISE...AND THEN PERSISTING UNTIL 14/15Z. GIVEN HIGH SOIL MOISTURE CONTENT FROM RECENT RAINFALL AND LIGHT WIND SPEEDS /WITH DRY AIR ALOFT/...I SEE NO REASON TO DISCOUNT GUIDANCE. /HART/. PREV DISCUSSION... /ISSUED 419 AM CDT THU APR 14 2016/ SHORT TERM (TODAY THROUGH FRIDAY)...WEAK NNE SFC WINDS EARLY THIS MORNING HAVE PRECLUDED MUCH IN THE WAY OF FOG FORMATION AS OF WRITING. HOWEVER...WITH EXPECTED SFC WINDS WEAKENING EVEN FURTHER SUNRISE...FEEL THAT A PERIOD OF FOG WILL BE POSSIBLE ACROSS PORTIONS OF INLAND S TX FOR A FEW HOURS LATE TONIGHT. OTHERWISE...ANY MORNING CLOUDINESS/FOG SHOULD QUICKLY MIX OUT BY MID MORNING WITH MOSTLY SUNNY SKIES PREVAILING TODAY. VERY DRY ATMOSPHERIC COLUMN ALOFT SHOULD RESULT IN A RAPID WARMUP TODAY. A LITTLE UNSURE AS TO HOW MUCH MIXING WILL OCCUR...BUT ALL IN ALL IT SHOULD FEEL EVEN LESS HUMID THAN YESTERDAY. MAX TEMPS WILL GENERALLY BE IN THE 80S...BUT HAVE UNDERCUT GUIDANCE BY A FEW DEGREES ACROSS NORTHERN TIER OF COUNTIES WHERE WETTER SOILS SHOULD SLIGHTLY LIMIT MAX HEATING POTENTIAL. WEAK MOISTURE ADVECTION TONIGHT MAY ALLOW MIN TEMPS ALONG THE RIO GRANDE TO BE A FEW DEGREES HIGHER THAN THIS MORNING/S VALUES...BUT TONIGHT SHOULD STILL FEEL RELATIVELY COMFORTABLE IF OUTDOORS. H85 TEMPS ARE PROG TO INCREASE A COUPLE OF DEGREES FRIDAY AND AS SUCH I HAVE GONE A COUPLE OF DEGREES WARMER FOR MAX TEMPS...MAINLY OVER THE BRUSH COUNTRY /MORE ESERLY WIND DIRECTION ACROSS THE EAST MAY ALLOW TEMPS TO BE A DEGREE OR TWO COOLER THAN TODAY/...WITH CONTINUED DRY AIR ALOFT RESULTING IN MOSTLY SUNNY SKIES. LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...THE DETERMINISTIC GFS/ECMWF/NAM CONTINUE TO PREDICT AN UPPER LEVEL LOW TO DEVELOP OVER THE WRN CONUS EARLY IN THE PERIOD. THIS SYSTEM IS PREDICTED TO REMAIN QUASI-STATIONARY OVER THE SWRN CONUS/FOUR CORNERS REGION SATURDAY/SUNDAY. INCREASING ONSHORE FLOW IS EXPECTED OVER THE CWA/MSA IN RESPONSE TO THIS SYSTEM WITH PWAT VALUES ABOVE NORMAL BY SATURDAY AFTN (GFS DETERMINISTIC) AND SCEC/SCA CONDITIONS OVER THE COASTAL WATERS LATE SATURDAY/SUNDAY. ANTICIPATE THAT INCREASING MSTR WL CONTRIBUTE TO ISOLD/SCT CONVECTION OVER THE CWA SATURDAY. DYNAMICS ASSOCIATED WITH THE UPPER SYSTEM IS EXPECTED TO RESULT IN SCATTERED/NUMEROUS CONVECTION OVER THE CWA/MSA SUNDAY/MONDAY. CONDITIONS MIGHT BE FAVORABLE FOR STRONG/SEVERE THUNDERSTORMS GIVEN THAT THE GFS DETERMINITIC PREDICT BRN VALUES IN THE SUPERCELLULAR RANGE OVER THE ERN CWA SUNDAY/MONDAY AFTN. THE UPPER LOW IS PREDICTED TO BREAKDOWN TUESDAY/WEDNESDAY (PER ECMWF/GFS DETERMINISTIC AND SUGGESTED BY THE GFS ENSEMBLE MEAN.) YET...PWAT VALUES ARE PREDICTED TO REMAIN ABOVE NORMAL TUESDAY/WEDNESDAY (GFS DETERMINISTIC) SUFFICIENT FOR ISOLD/SCT CONVECTON. STRONG STORMS REMAIN PSBL TUESDAY/WEDNESDAY CONSIDERING 2500-3000 J/KG CAPE VALUES PER THE GFS DETERMINISTIC. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 84 62 84 69 80 / 0 0 0 10 30 VICTORIA 83 61 82 65 79 / 0 0 0 10 30 LAREDO 87 64 90 69 86 / 0 0 0 10 30 ALICE 85 58 86 66 81 / 0 0 0 10 30 ROCKPORT 81 65 82 69 79 / 0 0 0 10 30 COTULLA 84 60 87 66 82 / 10 0 0 10 40 KINGSVILLE 85 62 85 68 81 / 0 0 0 10 30 NAVY CORPUS 82 67 81 70 79 / 0 0 0 10 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: BEE...CALHOUN...DUVAL...GOLIAD...LA SALLE...LIVE OAK...MCMULLEN...REFUGIO...VICTORIA...WEBB. GM...NONE. && $$ RH/79...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
533 AM CDT THU APR 14 2016 .DISCUSSION...AFTER COLLABORATING WITH EWX...DECIDED TO ISSUE A DENSE FOG ADVISORY FOR AREAS FROM LA SALLE COUNTY EASTWARD TO VICTORIA COUNTY. VISIBILITIES PREVAILING AT 1/4 MILE AT KVCT WITH MILITARY SITES ACROSS RURAL AREAS OF MCMULLEN COUNTY ALSO REPORTING DENSE FOG. SREF...NARRE-TL...AND HRRR RUNS INDICATE DENSE FOG EXPANDING IN AREAL COVERAGE THROUGH SUNRISE...AND THEN PERSISTING UNTIL 14/15Z. GIVEN HIGH SOIL MOISTURE CONTENT FROM RECENT RAINFALL AND LIGHT WIND SPEEDS /WITH DRY AIR ALOFT/...I SEE NO REASON TO DISCOUNT GUIDANCE. /HART/. && .PREV DISCUSSION... /ISSUED 419 AM CDT THU APR 14 2016/ SHORT TERM (TODAY THROUGH FRIDAY)...WEAK NNE SFC WINDS EARLY THIS MORNING HAVE PRECLUDED MUCH IN THE WAY OF FOG FORMATION AS OF WRITING. HOWEVER...WITH EXPECTED SFC WINDS WEAKENING EVEN FURTHER SUNRISE...FEEL THAT A PERIOD OF FOG WILL BE POSSIBLE ACROSS PORTIONS OF INLAND S TX FOR A FEW HOURS LATE TONIGHT. OTHERWISE...ANY MORNING CLOUDINESS/FOG SHOULD QUICKLY MIX OUT BY MID MORNING WITH MOSTLY SUNNY SKIES PREVAILING TODAY. VERY DRY ATMOSPHERIC COLUMN ALOFT SHOULD RESULT IN A RAPID WARMUP TODAY. A LITTLE UNSURE AS TO HOW MUCH MIXING WILL OCCUR...BUT ALL IN ALL IT SHOULD FEEL EVEN LESS HUMID THAN YESTERDAY. MAX TEMPS WILL GENERALLY BE IN THE 80S...BUT HAVE UNDERCUT GUIDANCE BY A FEW DEGREES ACROSS NORTHERN TIER OF COUNTIES WHERE WETTER SOILS SHOULD SLIGHTLY LIMIT MAX HEATING POTENTIAL. WEAK MOISTURE ADVECTION TONIGHT MAY ALLOW MIN TEMPS ALONG THE RIO GRANDE TO BE A FEW DEGREES HIGHER THAN THIS MORNING/S VALUES...BUT TONIGHT SHOULD STILL FEEL RELATIVELY COMFORTABLE IF OUTDOORS. H85 TEMPS ARE PROG TO INCREASE A COUPLE OF DEGREES FRIDAY AND AS SUCH I HAVE GONE A COUPLE OF DEGREES WARMER FOR MAX TEMPS...MAINLY OVER THE BRUSH COUNTRY /MORE ESERLY WIND DIRECTION ACROSS THE EAST MAY ALLOW TEMPS TO BE A DEGREE OR TWO COOLER THAN TODAY/...WITH CONTINUED DRY AIR ALOFT RESULTING IN MOSTLY SUNNY SKIES. LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...THE DETERMINISTIC GFS/ECMWF/NAM CONTINUE TO PREDICT AN UPPER LEVEL LOW TO DEVELOP OVER THE WRN CONUS EARLY IN THE PERIOD. THIS SYSTEM IS PREDICTED TO REMAIN QUASI-STATIONARY OVER THE SWRN CONUS/FOUR CORNERS REGION SATURDAY/SUNDAY. INCREASING ONSHORE FLOW IS EXPECTED OVER THE CWA/MSA IN RESPONSE TO THIS SYSTEM WITH PWAT VALUES ABOVE NORMAL BY SATURDAY AFTN (GFS DETERMINISTIC) AND SCEC/SCA CONDITIONS OVER THE COASTAL WATERS LATE SATURDAY/SUNDAY. ANTICIPATE THAT INCREASING MSTR WL CONTRIBUTE TO ISOLD/SCT CONVECTION OVER THE CWA SATURDAY. DYNAMICS ASSOCIATED WITH THE UPPER SYSTEM IS EXPECTED TO RESULT IN SCATTERED/NUMEROUS CONVECTION OVER THE CWA/MSA SUNDAY/MONDAY. CONDITIONS MIGHT BE FAVORABLE FOR STRONG/SEVERE THUNDERSTORMS GIVEN THAT THE GFS DETERMINITIC PREDICT BRN VALUES IN THE SUPERCELLULAR RANGE OVER THE ERN CWA SUNDAY/MONDAY AFTN. THE UPPER LOW IS PREDICTED TO BREAKDOWN TUESDAY/WEDNESDAY (PER ECMWF/GFS DETERMINISTIC AND SUGGESTED BY THE GFS ENSEMBLE MEAN.) YET...PWAT VALUES ARE PREDICTED TO REMAIN ABOVE NORMAL TUESDAY/WEDNESDAY (GFS DETERMINISTIC) SUFFICIENT FOR ISOLD/SCT CONVECTON. STRONG STORMS REMAIN PSBL TUESDAY/WEDNESDAY CONSIDERING 2500-3000 J/KG CAPE VALUES PER THE GFS DETERMINISTIC. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 84 62 84 69 80 / 0 0 0 10 30 VICTORIA 83 61 82 65 79 / 0 0 0 10 30 LAREDO 87 64 90 69 86 / 0 0 0 10 30 ALICE 85 58 86 66 81 / 0 0 0 10 30 ROCKPORT 81 65 82 69 79 / 0 0 0 10 30 COTULLA 84 60 87 66 82 / 10 0 0 10 40 KINGSVILLE 85 62 85 68 81 / 0 0 0 10 30 NAVY CORPUS 82 67 81 70 79 / 0 0 0 10 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR THE FOLLOWING ZONES: BEE...GOLIAD...LA SALLE...LIVE OAK... MCMULLEN...VICTORIA. GM...NONE. && $$ RH/79...UPDATE
AREA FORECAST DISCUSSION
NWS SEATTLE WA
309 AM PDT THU APR 14 2016 .SYNOPSIS... A WEAKENING STORM SYSTEM WILL CROSS WESTERN WASHINGTON TODAY...BRINGING SHOWERS TODAY THAT WILL LINGER INTO EARLY FRIDAY. AS A STRONG RIDGE OF HIGH PRESSURE BUILD ACROSS THE WEST COAST THIS WEEKEND...TEMPERATURES ARE EXPECTED TO CLIMB WELL ABOVE NORMAL BY LATE THIS WEEKEND AND INTO EARLY NEXT WEEK WITH MORE SUNSHINE AND DRY CONDITIONS. SHOWERS POSSIBLY RETURN TO THE AREA BY LATER TUESDAY. && .SHORT TERM... LOW PRESSURE IS SWIRLING OFF THE WEST COAST THIS MORNING. A BAND OF LIGHT TO MODERATE RAIN CONTINUES TO PROGRESS STEADILY NORTH OVER THE AREA THIS MORNING. THE BACK EDGE IS MOVING STEADILY AND PRESENTLY SHIFTING NORTH OF THE SEATTLE AREA. A SECONDARY AREA OF SHOWERS REMAINS OVER THE SOUTHWEST COAST OF WASHINGTON AND OFFSHORE. THE LATEST HRRR DEPICTS THE OFFSHORE LOW CENTER WEAKENING WITH RISING CENTRAL PRESSURE AS IT MOVES EASTWARD. SOME LIGHT SHOWER ACTIVITY SHOULD STILL IMPACT THE AREA THIS MORNING AND INTO EARLY THIS AFTERNOON BUT THE MAJORITY OF THE MORE SUBSTANTIAL RAINFALL WILL REMAIN SOUTH OF THE FORECAST AREA. WILL CONTINUE THE FORECAST GENERALLY AS IT WAS...LINGERING MOUNTAIN SNOW FOR THE WINTER WEATHER ADVISORY TO CONTINUE IN EFFECT TODAY. TEMPERATURES REMAIN AROUND NORMAL TODAY. THE LOW WILL PIVOT QUICKLY EAST AS IT FILLS AND SHOWER ACTIVITY DIMINISHES BY EARLY FRIDAY. SATURDAY WILL BE A MORE TRANSITIONAL DAY WITH 500 MB HEIGHTS RISING BUT A CHANCE OF SHOWERS REMAINING IN THE FORECAST. SHOWERS MAINLY CONFINED TO OLYMPIC PENINSULA. .LONG TERM...HEIGHTS WILL THEN RISE SIGNIFICANTLY ON SUNDAY WITH A MID LEVEL RIDGE AXIS ATOP EAST- CENTRAL WASHINGTON. 850 MB TEMPS CLIMB AS WELL AND 70S TO 80S WILL RETURN FOR THE HIGH TEMPERATURES ON SUNDAY AND MONDAY. 850 MB TEMPS AT +14 TO +16C AND SURFACE THERMAL TROUGH SLIDES OFF THE COAST TO ALLOW FOR OFFSHORE FLOW. TEMPERATURES WILL BE WELL ABOVE THE SEASONAL NORMALS OF AROUND 60 DEGREES FOR HIGHS. LOOKS TO BE DRY AND SUNNY AS WELL WITH THE RIDGING AND OFFSHORE FLOW. NEXT RAIN CHANCES LOOK TO RETURN ON TUESDAY WITH LOWERING HEIGHTS AND OFFSHORE STORM SYSTEM LIFTING NORTH. && .AVIATION...AN UPPER LOW WILL MOVE ONSHORE OVER SOUTHWEST WASHINGTON TODAY AND SHIFT INLAND TONIGHT WITH SOUTHERLY FLOW ALOFT TODAY BECOMING NORTHERLY TONIGHT. AT THE SURFACE...A FILLING 999 MILLIBAR LOW WILL MOVE ONSHORE OVER SOUTHWEST WASHINGTON TODAY WITH ONSHORE FLOW BEHIND THE LOW LATER TODAY AND TONIGHT. THE AIR MASS IS MOIST AND SLIGHTLY UNSTABLE...BECOMING STABLE TONIGHT. KSEA...A BAND OF RAIN AND LOW CLOUDS WILL MOVE NORTH OF THE TERMINAL EARLY THIS MORNING. LOW CLOUDS SHOULD PERSIST TODAY BUT CEILINGS SHOULD LIFT A BIT AND BE GENERALLY VFR. SOUTHERLY WIND 4-8 KNOTS BECOMING NORTHWEST THIS AFTERNOON. SCHNEIDER && .MARINE...A FILLING 999 MILLIBAR LOW WILL MOVE ONSHORE OVER SOUTHWEST WASHINGTON TODAY WITH ONSHORE FLOW BEHIND THE LOW LATER TODAY AND TONIGHT. SMALL CRAFT ADVISORY SOUTHERLY WINDS FOR THE COASTAL WATERS SHOULD EASE IN THE NEXT FEW HOURS. A ROUND OF SMALL CRAFT WEST WINDS IS EXPECTED IN THE CENTRAL AND EAST STRAIT THIS EVENING. THERE WILL ALSO BE WEST SWELL 10-15 FEET OVER THE COASTAL WATERS TODAY AND TONIGHT. A WEAK FRONT WILL MOVE INTO THE OFFSHORE WATERS FRIDAY...THEN SHIFT NORTH FRIDAY NIGHT AND SATURDAY. WEAK HIGH PRESSURE WILL BE OVER THE WATERS SATURDAY. OFFSHORE FLOW WILL DEVELOP SUNDAY AS A THERMAL TROUGH BUILDS NORTH ALONG THE WEST COAST. SCHNEIDER && .SEW WATCHES/WARNINGS/ADVISORIES... WA...WINTER WEATHER ADVISORY UNTIL 1 PM PDT THIS AFTERNOON FOR CASCADES OF PIERCE AND LEWIS COUNTIES-CASCADES OF SNOHOMISH AND KING COUNTIES. PZ...SMALL CRAFT ADVISORY UNTIL 6 AM PDT EARLY THIS MORNING FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 AM THIS MORNING TO 6 AM PDT FRIDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM. SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 5 AM PDT FRIDAY FOR GRAYS HARBOR BAR. SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM PDT FRIDAY FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL MIDNIGHT PDT TONIGHT FOR WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA. && $$ WWW.WEATHER.GOV/SEATTLE YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
254 PM PDT THU APR 14 2016 .SYNOPSIS....DRY WEATHER CONDITIONS WILL RETURN TO MOST AREAS BY LATE MORNING THURSDAY AND THEN CONTINUE THROUGH THE WEEKEND...ALONG WITH A SIGNIFICANT WARMING TREND. COOLING IS THEN EXPECTED MONDAY AND TUESDAY OF NEXT WEEK AS AN UPPER TROUGH APPROACHES THE WEST COAST. && .DISCUSSION...AS OF 2:50 PM PDT THURSDAY...IN THE SHORT TERM...A FEW INSTABILITY SHOWERS WILL BE POSSIBLE OVER THE NORTH BAY. THE LATEST HRRR MODEL OUTPUT INDICATES A FEW SHOWERS WILL BE POSSIBLE THROUGH 23-00Z. THERE HAVE ALSO BEEN A FEW SPOTTER REPORTS OF LIGHT RAIN OVER WINDSOR AND SANTA ROSA. EXPECT SHOWER ACTIVITY TO DIMINISH RAPIDLY AS THE SUN SETS. A NOWCAST HAS BEEN ISSUED TO HIGHLIGHT SHOWERS THROUGH 23Z. IN ADDITION TO THE POST FRONTAL SHOWERS...WINDS WILL BE BRISK LATE THIS AFTERNOON WITH COLD ADVECTION UNDERWAY. REST OF THE FORECAST REMAINS MOSTLY UNCHANGED. FOR SEVERAL DAYS NOW...WEATHER MODELS HAVE BEEN ADVERTISING A NICE RIDGE OVER THE REGION FRIDAY INTO THE WEEKEND. AS A RESULT...RAPID WARMING AND DRYING WILL OCCUR. FORECAST 850MB TEMPERATURES ARE FORECAST TO BE 1-2 STD DEVIATIONS ABOVE NORMAL OVER THE WEEKEND. THE WARM AIRMASS WILL TRANSLATE TO DAYTIME HIGHS IN THE 70S AND 80S...INTERIOR POSS LOW 90S ON SUNDAY. SUNDAY APPEARS TO BE THE WARMEST DAY OF THE WEEKEND WITH HIGHS 5 TO 10 DEGREES ABOVE NORMAL. UPPER LEVEL RIDGE WEAKENS EARLY NEXT WEEK WITH INCREASED ONSHORE FLOW. A COOL DOWN WILL BE NOTICED ON MONDAY AND TUESDAY. LONGER RANGE MODELS DO GENERALLY AGREE THAT THE TAIL END OF AN UPPER LEVEL TROUGH WILL APPROACH OUR COAST IN THE TUESDAY TO TUESDAY NIGHT TIME FRAME...BUT RAIN CHANCES PRESENTLY APPEAR MINIMAL AS GENERAL CONSENSUS THAT IT WILL THEN WEAKEN AND LIFT QUICKLY TO THE NORTH- NORTHEAST BEFORE MOVING ONSHORE. && .AVIATION...AS OF 11:00 AM PDT THURSDAY... REGION IS IN A POST COLD FRONTAL ENVIRONMENT. RAIN SHOWERS HAVE ENDED. WIDESPREAD VFR TODAY WITH BREEZY/GUSTY ONSHORE WINDS ALONG THE COAST. CUMULUS WILL CONTRIBUTE TO FEW TO SCT CLOUDS FROM 3000-5000 FT TODAY. VICINITY OF KSFO...VFR CONDITIONS WITH GUSTY WEST WINDS TODAY. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...VFR. GUSTY W-NW WINDS TODAY. && .MARINE...AS OF 2:52 PM PDT THURSDAY...BREEZY NORTHWEST WINDS WILL PREVAIL TONIGHT AND THROUGH TOMORROW AS HIGH PRESSURE GRADUALLY BUILDS OVER THE COASTAL WATERS. NORTHWESTERLY SWELLS WILL BUILD THROUGH TONIGHT THEN SUBSIDE LATER FRIDAY INTO THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY SOUTH TO MONTEREY COUNTY SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...MRY BAY && $$ PUBLIC FORECAST: MM AVIATION: DRP MARINE: DRP VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1107 AM PDT THU APR 14 2016 .SYNOPSIS....SHOWER CHANCES WILL DIMINISH DURING THE MORNING HOURS AS THE WEAK COLD FRONT NOW MOVING THROUGH OUR DISTRICT DISSIPATES. DRY WEATHER CONDITIONS WILL RETURN TO MOST AREAS BY LATE MORNING THURSDAY AND THEN CONTINUE THROUGH THE WEEKEND...ALONG WITH A SIGNIFICANT WARMING TREND. COOLING IS THEN EXPECTED MONDAY AND TUESDAY OF NEXT WEEK AS AN UPPER TROUGH APPROACHES THE WEST COAST. && .DISCUSSION...AS OF 4:05 AM PDT THURSDAY...SATELLITE IMAGERY SHOWS THE PRIMARY COLD FRONTAL CLOUD BAND PUSHING THROUGH THE MIDDLE OF OUR DISTRICT WHILE LATEST KMUX RADAR DATA SHOW AREAS OF SHOWERS EXTENDING FROM THE CENTRAL SF BAY AREA SOUTH THROUGH THE SANTA CRUZ MOUNTAINS. THE HIGHEST RAINFALL TOTAL NOTED THUS FAR IS 0.69 INCHES AT THE MIDDLE PEAK (MT TAMALPAIS) RAWS SITE IN MARIN COUNTY...WITH MOST LOWER ELEVATION LOCATIONS AROUND THE BAY HAVING RECEIVED LESS THAN TWO TENTHS OF AN INCH. LATEST HRRR AND NAM MODEL OUTPUT REMAIN IN GOOD AGREEMENT IN WEAKENING AND THEN DISSIPATING THE FRONT AS IT MOVES SOUTHWARD THROUGH MONTEREY COUNTY DURING THE FIRST PART OF THE MORNING. BY LATE MORNING DRY CONDITIONS ARE EXPECTED TO GENERALLY PREVAIL ACROSS THE CWA...WITH JUST A CHANCE OF A FEW LINGERING POST- FRONTAL LIGHT SHOWERS...PRIMARILY OVER NORTHERN SONOMA COUNTY. THE AIRMASS BEHIND THE FRONT WILL BE QUITE COOL...WITH 850 MB TEMPS FORECAST TO DROP AS LOW AS ZERO TO ONE DEG C IN THE NORTH BAY BY LATER THIS MORNING. BUT MID-APRIL DIURNAL HEATING WILL PARTIALLY COMPENSATE WITH THE NET RESULT OF LOWER ELEVATION MAX TEMPS AROUND THE BAYS STILL MOSTLY REACHING UP INTO THE LOWER TO MID 60S. IT WILL BE A BIT BRISK NEAR THE COAST THOUGH...AS NORTHWEST WINDS PICK UP THERE DURING THE AFTERNOON HOURS. THEN ON FRIDAY...MODELS REMAIN IN EXCELLENT AGREEMENT IN RAPIDLY BUILDING A STRONG UPPER LEVEL RIDGE NORTHEASTWARD INTO THE WEST COAST...AND SURFACE HIGH PRESSURE INTO THE PACIFIC NORTHWEST AND NORTHERN GREAT BASIN. SUNNY CONDITIONS ARE EXPECTED TO PREVAIL DISTRICTWIDE...AND IN COMBINATION WITH AIR MASS WARMING AND PROGRESSIVELY DRIER AND MORE OFFSHORE ORIENTED FLOW RESULT IN THE BEGINNING OF A SIGNIFICANT WARMING TREND. AFTERNOON HIGHS ON FRIDAY WILL GENERALLY BE 4 TO 7 DEG WARMER THAN THOSE TODAY...BUT LOCALLY UP TO 10-12 DEGREES WARMER IN NORTH BAY VALLEY LOCATIONS SUCH AS THE SANTA ROSA AREA WHERE DOWNSLOPE WARMING EFFECTS ARE MAXIMIZED. OVER THE WEEKEND...THE WARMING TREND WILL CONTINUE. BASED ON LATEST MODEL OUTPUT AND ASSOCIATED MOS GUIDANCE...ESPECIALLY FROM THE ECMWF WHICH TENDS TO DO WELL IN SUCH SITUATIONS...HAVE BUMPED UP AFTERNOON HIGHS BOTH SATURDAY AND SUNDAY FROM INHERITED GRIDS AND FORECASTS. CURRENT THINKING IS THAT WILL SEE WIDESPREAD MID 70S TO LOWER 80S ON SATURDAY...AND THEN 80S ACROSS MUCH OF THE DISTRICT ON SUNDAY WITH WARMEST INLAND LOCATIONS BRUSHING UPWARDS TOWARDS 90 DEG. IN THE EXTENDED...THE UPPER LEVEL RIDGE AXIS IS FORECAST TO BEGIN SHIFTING EASTWARD ALONG WITH A RETURN TO MORE ONSHORE ORIENTED SURFACE FLOW. THE NET RESULT WILL BE A SIGNIFICANT COOLING TREND WORKING ITS WAY INLAND MONDAY AND TUESDAY. LONGER RANGE MODELS DO GENERALLY AGREE THAT THE TAIL END OF AN UPPER LEVEL TROUGH WILL APPROACH OUR COAST IN THE TUESDAY TO TUESDAY NIGHT TIME FRAME...BUT RAIN CHANCES PRESENTLY APPEAR MINIMAL AS GENERAL CONSENSUS THAT IT WILL THEN WEAKEN AND LIFT QUICKLY TO THE NORTH- NORTHEAST BEFORE MOVING ONSHORE. && .AVIATION...AS OF 11:00 AM PDT THURSDAY... REGION IS IN A POST COLD FRONTAL ENVIRONMENT. RAIN SHOWERS HAVE ENDED. WIDESPREAD VFR TODAY WITH BREEZY/GUSTY ONSHORE WINDS ALONG THE COAST. CUMULUS WILL CONTRIBUTE TO FEW TO SCT CLOUDS FROM 3000-5000 FT TODAY. VICINITY OF KSFO...VFR CONDITIONS WITH GUSTY WEST WINDS TODAY. SFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY TERMINALS...VFR. GUSTY W-NW WINDS TODAY. && .MARINE...AS OF 4:06 AM PDT THURSDAY...A COLD FRONT WILL CONTINUE TO MOVE RAPIDLY SOUTHEAST THIS MORNING. WINDS WILL BECOME NORTHWESTERLY TODAY. NORTHWESTERLY SWELLS WILL BUILD TODAY AND TONIGHT THEN SUBSIDE LATER FRIDAY INTO THE WEEKEND. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY SOUTH TO MONTEREY COUNTY SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 3 PM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 11 AM SCA...PT ARENA TO PT REYES 0-10 NM FROM 11 AM SCA...PT REYES TO PIGEON PT 0-10 NM FROM 3 PM SCA...ROUGH BAR ADVISORY FOR SF BAR SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...MRY BAY FROM 11 AM && $$ PUBLIC FORECAST: BLIER AVIATION: DRP MARINE: DRP VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1217 PM CDT THU APR 14 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 319 AM CDT THU APR 14 2016 The quiet weather pattern will continue through tonight with dry conditions and slightly above-normal temperatures. Water vapor imagery showed the closed mid-level low continuing to track eastward across Oklahoma into Arkansas, with some low/mid clouds extending into far east central Kansas early this morning. Aside from this wave, the region will generally be under a weak mid-level ridge through tonight as a closed low moves into the Pacific Northwest today and will cause a deep trough to develop across the western U.S. tonight into Friday. Surface winds will remain out of the south/southeast today and tonight as the region stays wedged between high pressure to the east and low pressure across the Rockies and High Plains. With the exception of a few low clouds that may skim across portions of north central Kansas this morning, skies will be mostly sunny today with the southerly winds helping to push afternoon high temperatures into the low/mid 70s once again. These southerly winds will also continue to advect more moisture into the region, with dewpoint temperatures staying in the 40s today which will keep minimum relative humidity values in the mid 30 to low 40 percent range. Winds may become breezy at times this afternoon across north central Kansas with gusts of 20-25mph. Gusts may only diminish to 15-20mph in that region overnight, which will keep temperatures a few degrees warmer than early this morning. In addition to these persistent southerly winds, some mid-level clouds may begin to move into central Kansas by Friday morning ahead of the approaching system. With these conditions in place, lows tonight should only drop into the upper 40s to low 50s. .LONG TERM...(Friday through Wednesday) Issued at 319 AM CDT THU APR 14 2016 The latest model consensus with regards to the slow moving four corners upper low is for a little slower movement than previous model runs. The upper low will be between the ridge in the western U.S. and western Canadian provinces and the upper high pressure over the eastern states. The upper low is forecast to gradually move eastward and fill as it moves out into the plains next week. There is a good signal for precipitation late in the weekend through the first half of next week across central and eastern Kansas. With the slow progression deep moisture will stream northward from the Gulf into the Plains for much of the period. Initially most of the forcing and moisture will be over the Rockies and High Plains then gradually shift eastward with time. Therefore have gone dry on Friday then gradually introducing precipitation chances to areas of north central Kansas beginning Friday night through Saturday night. By Sunday and Monday large scale forcing will increase across central and eastern Kansas with a energy ejects out into the Plains. Also by Monday low pressure will develop over central Kansas with a cold front extending south into Texas with a warm/stationary front near Interstate 70 with the low/inverted trough progressing eastward across eastern Kansas on Tuesday. Good moisture in place along with MUCAPE around 1000 J/kg Monday and Tuesday afternoon with 0-6 KM shear around 25-30 kts may see a few strong storms, but mainly beneficial rainfall. Precipitation chances continue into Wednesday as the system remains and weakens over the Plains. Temperatures mainly in the 70s through Sunday cooling off into the 60s for the first half of the week. Lows mainly in the 50s. && .AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon) Issued at 1216 PM CDT THU APR 14 2016 VFR conditions for the day today with some potential MVFR visbys toward morning as moisture continues to increase and may bring another round of haze/fog. Winds increase once again on Friday but late enough in the period to not yet include here. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Hennecke LONG TERM...53 AVIATION...67
Area Forecast Discussion National Weather Service Dodge City KS 1200 PM CDT THU APR 14 2016 ...Updated Aviation... .SHORT TERM...(Today and tonight) Issued at 256 AM CDT Thu Apr 14 2016 Stratus expanding across the area this morning, and it`s potential impacts on the temperature through the day is the immediate weather story. Fog was overdone in the NAM model, and may be overdone as well by the HRRR solutions going forward early this morning. However the expansion of stratus with bases at or under 500 ft continues this morning in a weak moisture advection environment. Going forward this afternoon, the models account for cloud dissipation by having much cooler temperatures in central Kansas. The surface high pressure will continue to shift east of the Mississippi valley, increasing the surface pressure gradient over western KS, and allowing moderate to strong southerly winds to develop especially once mixing maximizes this afternoon. Very low pops are in place tonight, following the convective allowing models reflectivity fields/weak cape and upslope environment with exiting shortwave ridge. however the real increase in precipitation chances comes on Friday afternoon with what could potentially be a few severe thunderstorms given the low to moderate cape values and strong bulk shear. .LONG TERM...(Friday through Wednesday) Issued at 256 AM CDT Thu Apr 14 2016 A well advertised so far thunderstorm/heavy rain event is still the main story in the medium range timeframe. All of the models are consistent in the large upper low stalling over the far southern Rockies/northern New Mexico region from Friday night into Monday morning. The gulf fetch will be wide open for this event, and a persistent rain looks to really get going by late Saturday and not end until early Monday at best. Several inches of rain are likely across most of the forecast area, and even localized flooding possible becoming a reality where rainfall duration and intensity are largest over low lying drainage areas. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1200 PM CDT Thu Apr 14 2016 VFR through 06z Friday. Strong SE winds 20-30 kts through sunset, with higher gusts. SE winds will diminish a bit this evening, but remain quite elevated overnight near 18-20 kts. High confidence of MVFR/IFR cigs in stratus returning 06-12z Friday, with the highest impacts on aviation expected at DDC. LIFR cigs possible SE of DDC including P28. Patchy fog will redevelop after 06z as well, with areas of BR and reduced visibility. Lowest vis expected DDC and points SE. Consensus of short term models indicates MVFR cigs in stratus will persist until around 18z Friday. After 18z Friday, very strong SE winds will impact aviation operations with gusts near 40 kts. && .PRELIMINARY POINT TEMPS/POPS... DDC 74 53 74 55 / 0 10 20 60 GCK 77 53 74 53 / 10 20 40 70 EHA 80 54 75 52 / 10 10 60 70 LBL 78 53 75 54 / 0 10 40 70 HYS 75 52 74 54 / 0 20 30 50 P28 74 52 76 57 / 0 10 10 30 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Turner/White
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
156 PM EDT THU APR 14 2016 .SYNOPSIS... HIGH PRESSURE REMAINS CENTERED WELL NORTH OF THE AREA THROUGH THE WEEKEND...RESULTING IN AN EXTENDED PERIOD OF DRY WEATHER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST SFC ANALYSIS SHOWS BROAD STRONG HI PRES CENTERED OVER SE CANADA. ALOFT...AN UPR-LEVEL TROF IS PIVOTING OFF THE ERN SEABOARD. DRY WX CONTINUES TDA WITH THE MID ATLC UNDER THE INFLUENCE OF THE SFC HI TO THE N. INCLUDED PATCHY FROST THIS MORNG IN PARTS OF THE CWA WITH TEMPS GETTING A COUPLE DEGREES LWR THAN PREVIOUSLY EXPECTED...BUT NOT WIDESPREAD OR LONG-LASTING ENUF TO WARRANT A FROST ADVSRY. ASIDE FM A FEW HI CLOUDS OVER SERN AREAS THIS MORNG...EXPECT A SUNNY SKY TDA UNDER N/NE FLOW. LOCAL LO- LEVEL THICKNESS TOOL WHICH HANDLED TEMPS WELL YESTERDAY CONTINUES TO INDICATE TEMPS ONLY REACHING THE UPR 50S TO LWR 60 MOST AREAS TDA...ABOUT FIVE TO 10 DEGREES BLO NORMAL FOR MID APRIL. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... LITTLE CHANGE SEEN IN THE BLOCKY PATTERN INTO THE WEEKEND. SFC HIGH TO THE NORTH PROGGED TO EXTEND DOWN THE EASTERN SEABOARD RESULTING IN A DRY PERIOD WITH ONLY SCT TO BKN HIGH / MID LEVEL CLOUDS FROM TIME TO TIME. PERSISTENT ONSHORE FLOW KEEPS TEMPS BELOW NORMAL BUT H85 TEMPS PROGGED TO SLOWLY RECOVER OVER TIME. THUS...SHOULD SEE HIGHS AND LOWS ABOUT 1-2 DEGREES WARMER EACH DAY. LOWS TONITE 35-40 AWAY FROM THE WATER...L-M40S AT THE BEACHES. HIGHS FRI IN THE L60S WEST OF THE BAY...55-60 ALONG THE COAST. LOWS FRI NITE U30S-M40S. HIGHS SAT L-M60S WEST OF THE BAY...U50S TO NEAR 60 ALONG THE COAST. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... HIGH PRESSURE CONTINUES TO WEDGE DOWN THE LEESIDE OF THE APPALACHIANS SAT NIGHT AS AN UPPER LEVEL RIDGE REMAINS STEADFAST OVER THE ERN HALF OF THE US. LOWS IN THE LOWER 40S INLAND AND AROUND 50 AT THE IMMEDIATE COAST. THE WEDGE ALONG THE APPALACHIANS BREAKS DOWN SUN AS THE HIGH SLIDES ACROSS THE REGION AND OVER THE GULF COAST STATES SUN NIGHT. ONSHORE N-NE WINDS WILL PERSIST DURING THIS TIME AND KEEP DAYTIME TEMPS COOL NEAR THE COAST. HIGHS IN THE UPPER 60S TO AROUND 70 INLAND...UPPER 50S TO LOWER 60S NEAR THE COAST. LOWS SUN NIGHT IN THE MID-UPPER 40S INLAND...LOW 50S BEACHES. A SFC LOW TRACKING ALONG THE US/SE CANADIAN BORDER SUN NIGHT GETS PUSHED DOWN ACROSS NRN NEW ENGLAND MON AND DRAGS A WEAK BACKDOOR FRONT ACROSS THE AREA MON NIGHT. THIS SHOULD RESULT IN A WIND SHIFT TO A W-NW DIRECTION ON MON AND START SPREADING CLOUDS INTO THE AREA FROM THE NORTH. MON SHOULD BE A DECENT DAY WITH MOSTLY SUNNY SKIES AND HIGHS IN THE MID-UPPER 70S (POSSIBLY 80) INLAND...MID 60S TO LOWER 70S CLOSER TO THE COAST. WINDS BECOME MORE NLY BEHIND THE WEAK FRONT MON NIGHT. MODELS HAVE BACKED OFF ON THE STRENGTH OF CAA IN THE WAKE OF THE FRONTAL PASSAGE AND CURRENTLY ANTICIPATE A MORE PESSIMISTIC FORECAST WITH INCREASED CLOUDS AND COOLER TEMPERATURES. LOWS EARLY MON NIGHT IN THE LOWER 50S. HIGHS TUE IN THE LOW 70S...MID-UPPER 60S CLOSER TO THE COAST...LOW 60S BEACHES. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... VFR CONDITIONS ACROSS AREA TERMINALS WILL PERSIST THROUGH THE 18Z TAF PERIOD AND BEYOND INTO EARLY NEXT WEEK. SFC HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA FROM SOUTHEAST CANADA THIS AFTERNOON, WITH GUSTY NNE WINDS ALONG THE COASTAL SECTIONS. THIS PATTERN WILL PERSIST THROUGH THE TAF PERIOD AS THE SURFACE HIGH SETTLES OVER THE PIEDMONT/INLAND AREAS. THIS SHOULD ALLOW THE ATMOSPHERE TO DECOUPLE TONIGHT OVER SBY/RIC AND POSSIBLE PHF SO SHOULD SEE WINDS GO VERY LIGHT AT THESE LOCATIONS WHILE NE WINDS SHOULD REMAIN AROUND 10 KT FOR ORF/ECG. THE WINDS WILL PICK UP AGAIN ON FRIDAY ONCE THE DAYTIME MIXING BEGINS BY AROUND 13Z. OUTLOOK...HIGH PRESSURE OVER SE CANADA AND THE NORTHEAST STATES WILL REMAIN IN CONTROL ACROSS THE REGION. A SERIES OF SOUTHERN STREAM DISTURBANCES WILL RIDE ALONG QUASI-STATIONARY BOUNDARY ORIENTED WELL TO THE SOUTH AND SOUTHEAST OF THE LOCAL AREA, MAINTAINING DRY WX/VFR CONDS FOR LOCAL TAF SITES THROUGH MONDAY. WINDS WILL REMAIN PREDOMINATELY FROM THE NORTH-NORTHEAST THROUGH THIS TIME FRAME. && .MARINE... FOR THE MORNING UPDATE HAVE MADE A FURTHER ADJUSTMENT TO THE SMALL CRAFT HEADLINES TO DROP SCA FOR THE LOWER CHESAPEAKE BAY ZONE AND LOWER JAMES RIVER ZONE...FOR TODAY...AS CURRENT CONDITIONS ARE WINDS AROUND 5 TO 10 KTS AND WAVES OF 1 TO 2 FT. THE SURFACE ANALYSIS SHOWS A 1035 MB AREA OF HIGH PRESSURE THAT IS CENTERED OVER EASTERN CANADA AND IS STRETCHING SOUTHWARD DOWN THE COAST THROUGH THE MID- ATLANTIC STATES INTO THE CAROLINAS. THE TIGHTER GRADIENT HAS SHIFTED OFF THE COAST KEEPING THE STRONGEST WINDS FURTHER OFF SHORE AND MORE INTO THE OUTER BANKS THAN INTO THE DELMARVA AND LOWER CHESAPEAKE BAY. LOOKING AT THE LATEST 6Z GUIDANCE, THE 11Z RUC AND OTHER HIGH RES MODELS...THE RIDGE OF HIGH PRESSURE SLOWLY SHIFTS WESTWARD INTO THE PIEDMONT LATER TONIGHT ALLOWING THE TIGHTER GRADIENT TO SHIFT MORE INTO THE LOWER CHESAPEAKE BAY SHOULD SEE WINDS AND SEAS BEGIN TO INCREASE AT THAT TIME. THUS...DROPPED SCA FLAGS FOR THOSE TWO ZONES FOR TODAY AND THIS EVENING...WITH THEM GOING BACK INTO EFFECT BEGINNING AT 1 AM EDT FRIDAY. PREV DISCUSSION... LATEST WX ANALYSIS FEATURES 1034+MB SFC HIGH PRESSURE OVER QUEBEC/NRN NEW ENGLAND, WEDGING DOWN THE LEESIDE OF THE APPALACHIANS...AS LOW PRESSURE MEANDERS OFFSHORE. RESULTANT TIGHT PRESSURE GRADIENT WILL CONTINUE TO RESULT IN STRONG ONSHORE (NNE) FLOW ON THE ORDER OF 15-25KT. NWPS/WAVEWATCH BOTH SIMILAR IN THEIR DEPICTION OF SIG WAVE HEIGHTS IN THE 5-8FT RANGE...8-10 FT IN SRN COASTAL WATERS BY FRI NIGHT. PER LATEST OBS AND HI-RES MODEL DEPICTION, HAVE DROPPED SCA FLAGS OVER THE MIDDLE BAY ZONE. WINDS WILL REMAIN IN THE 10-15KT RANGE, AND WHILE OCCASIONAL GUSTS TO LOW END SCA ARE EXPECTED IN THE NORTHERN/MIDDLE CHES BAY, PREDOMINATE CONDITIONS WILL REMAIN SUB-SCA NORTH OF NEW POINT COMFORT. FARTHER SOUTH, SCA FLAGS CONTINUE THROUGH FRI FOR THE LOWER CHES BAY (SOUTH OF NEW PT COMFORT) AND THE LOWER JAMES RIVER, AND THROUGH FRI NIGHT/EARLY SATURDAY FOR THE ATLANTIC COASTAL WATERS...CURRITUCK SOUND...AND THE MOUTH OF THE CHES BAY. A LOW PRESSURE SYSTEM DIVES SWD WELL OFF THE COAST...CREATING A STRONGER SURGE OF NNE WINDS, QUITE POSSIBLY OVER ALL ZONES FRIDAY AND FRIDAY NIGHT. ONSHORE WINDS/NE SWELL PERSIST THROUGH MUCH OF THE WEEKEND INTO SUN NIGHT...WITH SEAS WILL REMAIN RELATIVELY UNCHANGED WITH WAVE HEIGHTS OF 7-10FT SAT/SAT NIGHT. COOL AIR WEDGE FINALLY BEGINS TO BREAK BY LATE IN THE WEEKEND AS THE HIGH SLIDES OVERHEAD AS THE OFFSHORE LOW GETS SHUNTED FARTHER OFFSHORE. SEAS WILL LIKELY TAKE SOME TIME TO SUBSIDE BELOW 5 FT SCA THRESHOLD, LIKELY TAKING INTO MONDAY/MONDAY NIGHT, ESPECIALLY OVER SOUTHERN WATERS. A SFC LOW TRACKS ALONG THE US/SE CANADIAN BORDER MONDAY, AND GETS PUSHED DOWN ACROSS NRN NEW ENGLAND MON/MON NGT. THIS SYSTEM DRAGS A BACKDOOR FRONT SOUTH INTO THE NORTHEAST DURING THIS PERIOD, WITH THIS FRONT DROPPING ACROSS THE WATERS EARLY TUESDAY. THIS SHOULD RESULT IN A WIND SHIFT TO A W-NW DIRECTION MON NGT...BECOMING MORE NLY BEHIND THE WEAK FRONT TUE. MODELS HAVE BACKED OFF ON THE STRENGTH OF CAA IN THE WAKE OF THIS FRONTAL PASSAGE AND WOULD CONTINUE TO EXPECT A SUB-SCA PUSH IN WIND SPEEDS AOB 15KT DURING THIS TIME FRAME. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ634-650- 652-654-656-658. SMALL CRAFT ADVISORY FROM 1 AM TO 6 PM EDT FRIDAY FOR ANZ632- 638. SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT FRIDAY NIGHT FOR ANZ633. && $$ SYNOPSIS...MAS NEAR TERM...MAS SHORT TERM...MAS/MPR LONG TERM...BMD AVIATION...ESS MARINE...ESS/MAM
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1221 PM CDT THU APR 14 2016 .UPDATE... ISSUED AT 1136 AM CDT THU APR 14 2016 TEMPERATURES ARE WARMING VERY QUICKLY ACROSS WEST CENTRAL MN THIS MORNING. READINGS ARE ALREADY IN THE UPPER 70S...WHICH ARE ONLY A FEW DEGREES FROM EXPECTED HIGHS. RAISED HIGHS SEVERAL DEGREES IN THOSE LOCATIONS TO THE MID/UPPER 80S. RH VALUES HAVE RESPONDED ACCORDINGLY AND ARE NOW APPROACHING RED FLAG CRITERIA. FURTHER EAST...TEMPS HAVEN/T QUITE BEEN WARMING AS QUICKLY AND RH VALUES REMAIN IN THE 40S. THUS...NO EXPANSION WITH THE RED FLAG WARNING YET BUT CONDITIONS WILL BE CLOSELY MONITORED INTO EARLY AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 440 AM CDT THU APR 14 2016 WARM FRONT THAT REMAINED WELL DEFINED THROUGH THE DAY YESTERDAY AND THROUGH MUCH OF LAST NIGH WAS FINALLY STARTING TO BECOME LESS DEFINED IN THE WIND FIELD...THOUGH WAS STILL IDENTIFIABLE ACROSS CENTRAL MN. SOUTH OF THIS BOUNDARY...TEMPERATURES OVERNIGHT HAVE MOSTLY REMAINED ABOVE 50. AS WE GO THROUGH THE DAY...A 995 MB LOW WILL DEVELOP NEAR THE ND/SD/WY/MT REGION...WHICH PUT A MORE SRLY PRESSURE GRADIENT ACROSS THE AREA AND FINALLY FORCE WHAT IS LEFT OF THE WARM FRONT UP INTO NRN MN. THIS STRENGTHENING SRLY FLOW WILL ADVECT A LOW LEVEL THERMAL RIDGE INTO WRN MN ALONG ROUGHLY AN ABERDEEN TO BEMIDJI LINE. WITHIN THIS THERMAL RIDGE...WE REMAIN CONFIDENT IN HIGHS REACHING TO THE LOW 80S WEST OF A GRANITE FALLS TO STAPLES LINE. IN ADDITION...BASED ON A RAP/GFS MIXED LAYER DEWPOINTS...THIS PORTION OF WESTERN MN LOOKS TO GET CAUGHT BETWEEN AREAS OF SLIGHTLY HIGHER DEWPOINTS TO THEIR NORTH /NORTH OF THE WARM FRONT/ AND TO THE EAST AS AIR WITH SFC DEWPOINTS CURRENTLY IN THE MID 40S IN ERN NEB LOOKS TO GET ADVECTED UP TOWARD THE TWIN CITIES TODAY. THESE SLIGHTLY LOWER DEWPOINTS COINCIDING WITH HIGHS IN THE LOW 80S RESULTED IN A FAIRLY BROAD AREA WHERE MINIMUM HUMIDITIES ARE FORECAST TO GET DOWN BETWEEN 20 AND 25 PERCENT. INCIDENTALLY...THIS IS ALSO WHERE THE SPC INCLUDED AN ELEVATED AREA ON THE DAY 1 FIRE WEATHER RISK MAP...SO AFTER COORDINATION WITH MIFC ALONG WITH ABR/FSD/FGF...WE ENDED UP WITH THE RFW SEEN FROM 18Z THROUGH 00Z THIS AFTERNOON. FOR THE REST OF MN...WE HAVE HUMIDITY VALUES FORECAST TO GET DOWN TO BETWEEN 25 AND 35 PERCENT WITH SUSTAINED WINDS MORE 15 TO 25 MPH WITH GUSTS TO 30 MPH. THEREFORE OUTSIDE OF THE WARNING...AFTER COORDINATION WITH ARX/DLH...WILL HAVE A SPECIAL WEATHER STATEMENT FOR THE INCREASED FIRE DANGER ACROSS THE REST THE MPX MN COUNTIES. MAIN AREA OF LOWER CONFIDENCE TODAY IS WITH THE DEWPOINT FORECAST AND ATTENDANT HUMIDITY LEVELS. CURRENT FORECAST IS CERTAINLY ON THE LOW END OF THE DEWPOINT ENVELOP...BUT IN LINE WITH WHAT THE HRRR AND HOPWRF ARE SHOWING. IF THERE IS AN AREA THIS FORECAST GOOD BE A BUST IT IS WITH THE LOW HUMIDITY. HOWEVER...OVER THE LAST WEEK...WE HAVE HAD A COOL TEMPERATURE AND MOIST RH BIAS...SO FEEL CONFIDENT IN THE CURRENT SCENARIO DEPICTED IN THE GRIDS. FOR TONIGHT...IT WILL BE ANOTHER MILD NIGHT...WITH LOWS SIMILAR TO WHAT WE HAVE SEEN TO SOUTH OF THE WARM FRONT OVERNIGHT...UPPER 40S TO LOWER 50S THANKS TO SRLY WINDS CONTINUING TO BLOW. IN ADDITION...THE STRENGTHENING OF THE UPPER RIDGE OVER THE GREAT LAKES WILL HELP PUSH ANY CLOUDS/PRECIP EVEN FARTHER WEST OF WHAT WE WILL SEE TODAY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 440 AM CDT THU APR 14 2016 IT MAY BE TORNADO TEST DAY IN MN/WI...BUT THE WARM AND DRY WEATHER IS HERE TO STAY THROUGH SATURDAY GIVEN THE OMEGA BLOCK IN THE ATLANTIC. THE BLOCKING PATTERN IS KEEPING THE NE CONUS/EASTERN CANADIAN TROUGH IN PLACE...AND FARTHER UPSTREAM THE RIDGING IN PLACE ACROSS THE LOCAL AREA. HIGH TEMPERATURES IN THE 70S WILL BE THE RESULT LOCALLY FRI- SAT. A TROUGH MOVES INLAND OVER THE PACIFIC NORTHWEST TODAY...BUT DROPS ACROSS THE SOUTHWEST CONUS AND BECOMES CUTOFF FROM THE MAIN FLOW - THE 14.00Z GFS AND ECMWF CONTINUE TO KEEP THE UPPER LOW SPINNING AWAY DOWN ACROSS THE SOUTHWEST THROUGH EARLY NEXT WEEK BEFORE EVENTUALLY FILLING AND SHEARING OUT. THE SURFACE TROUGH AND COLD FRONT ASSOCIATED WITH THIS FEATURE WILL REMAIN IN THE DAKOTAS THROUGH FRIDAY...BUT THE LATEST GUIDANCE DOES TRY TO BRING THE BOUNDARY INTO THE FAR WESTERN FORECAST AREA ON SATURDAY...AND KEEPS IT THERE UNTIL SUNDAY...BEFORE SAGGING IT E-SE SUNDAY NIGHT INTO MONDAY. A FEW SHOWERS ARE POSSIBLE ON SATURDAY IN FAR WESTERN MINNESOTA DUE TO THE PRESENCE OF THIS BOUNDARY. THE REST OF THE FORECAST AREA COULD SEE RAIN SUNDAY AFTERNOON - SUNDAY NIGHT WHEN THIS BOUNDARY IS DRIVEN SOUTH BY A SHORTWAVE COMING OUT OF CANADA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1221 PM CDT THU APR 14 2016 VFR CONDITIONS EXPECTED. GUSTY SOUTH WINDS WILL EASE EARLY THIS EVENING...THEN INCREASE AGAIN FRIDAY MORNING. KMSP...NO ADDITIONAL CONCERNS. /OUTLOOK FOR KMSP/ SAT...VFR. WINDS S 10-15 KTS. SUN...MVFR CIG POSSIBLE. WINDS SW BCMG NW 5 KTS. MON...MVFR CIG POSSIBLE. WINDS NE 10-20 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ041-042- 047>049-054>057-064. && $$ UPDATE...BORGHOFF SHORT TERM...MPG LONG TERM...CLF AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1136 AM CDT THU APR 14 2016 .UPDATE... ISSUED AT 1136 AM CDT THU APR 14 2016 TEMPERATURES ARE WARMING VERY QUICKLY ACROSS WEST CENTRAL MN THIS MORNING. READINGS ARE ALREADY IN THE UPPER 70S...WHICH ARE ONLY A FEW DEGREES FROM EXPECTED HIGHS. RAISED HIGHS SEVERAL DEGREES IN THOSE LOCATIONS TO THE MID/UPPER 80S. RH VALUES HAVE RESPONDED ACCORDINGLY AND ARE NOW APPROACHING RED FLAG CRITERIA. FURTHER EAST...TEMPS HAVEN/T QUITE BEEN WARMING AS QUICKLY AND RH VALUES REMAIN IN THE 40S. THUS...NO EXPANSION WITH THE RED FLAG WARNING YET BUT CONDITIONS WILL BE CLOSELY MONITORED INTO EARLY AFTERNOON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 440 AM CDT THU APR 14 2016 WARM FRONT THAT REMAINED WELL DEFINED THROUGH THE DAY YESTERDAY AND THROUGH MUCH OF LAST NIGH WAS FINALLY STARTING TO BECOME LESS DEFINED IN THE WIND FIELD...THOUGH WAS STILL IDENTIFIABLE ACROSS CENTRAL MN. SOUTH OF THIS BOUNDARY...TEMPERATURES OVERNIGHT HAVE MOSTLY REMAINED ABOVE 50. AS WE GO THROUGH THE DAY...A 995 MB LOW WILL DEVELOP NEAR THE ND/SD/WY/MT REGION...WHICH PUT A MORE SRLY PRESSURE GRADIENT ACROSS THE AREA AND FINALLY FORCE WHAT IS LEFT OF THE WARM FRONT UP INTO NRN MN. THIS STRENGTHENING SRLY FLOW WILL ADVECT A LOW LEVEL THERMAL RIDGE INTO WRN MN ALONG ROUGHLY AN ABERDEEN TO BEMIDJI LINE. WITHIN THIS THERMAL RIDGE...WE REMAIN CONFIDENT IN HIGHS REACHING TO THE LOW 80S WEST OF A GRANITE FALLS TO STAPLES LINE. IN ADDITION...BASED ON A RAP/GFS MIXED LAYER DEWPOINTS...THIS PORTION OF WESTERN MN LOOKS TO GET CAUGHT BETWEEN AREAS OF SLIGHTLY HIGHER DEWPOINTS TO THEIR NORTH /NORTH OF THE WARM FRONT/ AND TO THE EAST AS AIR WITH SFC DEWPOINTS CURRENTLY IN THE MID 40S IN ERN NEB LOOKS TO GET ADVECTED UP TOWARD THE TWIN CITIES TODAY. THESE SLIGHTLY LOWER DEWPOINTS COINCIDING WITH HIGHS IN THE LOW 80S RESULTED IN A FAIRLY BROAD AREA WHERE MINIMUM HUMIDITIES ARE FORECAST TO GET DOWN BETWEEN 20 AND 25 PERCENT. INCIDENTALLY...THIS IS ALSO WHERE THE SPC INCLUDED AN ELEVATED AREA ON THE DAY 1 FIRE WEATHER RISK MAP...SO AFTER COORDINATION WITH MIFC ALONG WITH ABR/FSD/FGF...WE ENDED UP WITH THE RFW SEEN FROM 18Z THROUGH 00Z THIS AFTERNOON. FOR THE REST OF MN...WE HAVE HUMIDITY VALUES FORECAST TO GET DOWN TO BETWEEN 25 AND 35 PERCENT WITH SUSTAINED WINDS MORE 15 TO 25 MPH WITH GUSTS TO 30 MPH. THEREFORE OUTSIDE OF THE WARNING...AFTER COORDINATION WITH ARX/DLH...WILL HAVE A SPECIAL WEATHER STATEMENT FOR THE INCREASED FIRE DANGER ACROSS THE REST THE MPX MN COUNTIES. MAIN AREA OF LOWER CONFIDENCE TODAY IS WITH THE DEWPOINT FORECAST AND ATTENDANT HUMIDITY LEVELS. CURRENT FORECAST IS CERTAINLY ON THE LOW END OF THE DEWPOINT ENVELOP...BUT IN LINE WITH WHAT THE HRRR AND HOPWRF ARE SHOWING. IF THERE IS AN AREA THIS FORECAST GOOD BE A BUST IT IS WITH THE LOW HUMIDITY. HOWEVER...OVER THE LAST WEEK...WE HAVE HAD A COOL TEMPERATURE AND MOIST RH BIAS...SO FEEL CONFIDENT IN THE CURRENT SCENARIO DEPICTED IN THE GRIDS. FOR TONIGHT...IT WILL BE ANOTHER MILD NIGHT...WITH LOWS SIMILAR TO WHAT WE HAVE SEEN TO SOUTH OF THE WARM FRONT OVERNIGHT...UPPER 40S TO LOWER 50S THANKS TO SRLY WINDS CONTINUING TO BLOW. IN ADDITION...THE STRENGTHENING OF THE UPPER RIDGE OVER THE GREAT LAKES WILL HELP PUSH ANY CLOUDS/PRECIP EVEN FARTHER WEST OF WHAT WE WILL SEE TODAY. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 440 AM CDT THU APR 14 2016 IT MAY BE TORNADO TEST DAY IN MN/WI...BUT THE WARM AND DRY WEATHER IS HERE TO STAY THROUGH SATURDAY GIVEN THE OMEGA BLOCK IN THE ATLANTIC. THE BLOCKING PATTERN IS KEEPING THE NE CONUS/EASTERN CANADIAN TROUGH IN PLACE...AND FARTHER UPSTREAM THE RIDGING IN PLACE ACROSS THE LOCAL AREA. HIGH TEMPERATURES IN THE 70S WILL BE THE RESULT LOCALLY FRI- SAT. A TROUGH MOVES INLAND OVER THE PACIFIC NORTHWEST TODAY...BUT DROPS ACROSS THE SOUTHWEST CONUS AND BECOMES CUTOFF FROM THE MAIN FLOW - THE 14.00Z GFS AND ECMWF CONTINUE TO KEEP THE UPPER LOW SPINNING AWAY DOWN ACROSS THE SOUTHWEST THROUGH EARLY NEXT WEEK BEFORE EVENTUALLY FILLING AND SHEARING OUT. THE SURFACE TROUGH AND COLD FRONT ASSOCIATED WITH THIS FEATURE WILL REMAIN IN THE DAKOTAS THROUGH FRIDAY...BUT THE LATEST GUIDANCE DOES TRY TO BRING THE BOUNDARY INTO THE FAR WESTERN FORECAST AREA ON SATURDAY...AND KEEPS IT THERE UNTIL SUNDAY...BEFORE SAGGING IT E-SE SUNDAY NIGHT INTO MONDAY. A FEW SHOWERS ARE POSSIBLE ON SATURDAY IN FAR WESTERN MINNESOTA DUE TO THE PRESENCE OF THIS BOUNDARY. THE REST OF THE FORECAST AREA COULD SEE RAIN SUNDAY AFTERNOON - SUNDAY NIGHT WHEN THIS BOUNDARY IS DRIVEN SOUTH BY A SHORTWAVE COMING OUT OF CANADA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 530 AM CDT THU APR 14 2016 OUTSIDE OF SOME SCT CLOUDS BETWEEN 7K AND 10K FEET THROUGH THE MORNING FROM SOUTHERN INTO EASTERN MN AND WRN WI...IT WILL BE AN SKC TAF PERIOD WITH BREEZY SOUTH WINDS AS HAS BEEN ADVERTISED IN THE GUIDANCE AND OUR TAFS TO THIS POINT...SO FEW CHANGES WERE NEEDED. KMSP...IS SOME MARGINAL WIND SHEAR THIS MORNING THAT WILL START TO SUBSIDE AFTER 14Z AS WINDS VEER AND INCREASE IN SPEED...THUS REDUCING SHEAR. OTHERWISE ITS A HIGH CONFIDENCE KIND OF TAF. /OUTLOOK FOR KMSP/ FRI...VFR. WINDS SSE 10-20 KTS. SAT...VFR. WINDS S 10-15 KTS. SUN...MVFR CIG POSSIBLE. WINDS SW BCMG NW 5 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ041-042- 047>049-054>057-064. && $$ UPDATE...BORGHOFF SHORT TERM...MPG LONG TERM...CLF AVIATION...MPG
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
302 PM CDT THU APR 14 2016 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 257 PM CDT THU APR 14 2016 SOUTHWEST FLOW ALOFT SUPPORTING ELEVATED CONVECTION ATOP A VERY WARM AIR MASS. WITH TEMPERATURES IN THE 70S/80S AND DEW POINTS ONLY IN THE 40S...AND BASES AROUND 10KFT...SUCH A DEEP EVAPORATION LAYER LEADS ME TO BELIEVE WE WILL ONLY SEE THE ODD SPRINKLE AT THE SURFACE. THAT SAID...THE NAMDNG AND HRRR SIMULATE DEEPER CONVECTION DEVELOPING IN NORTH CENTRAL SOUTH DAKOTA/SOUTHERN NORTH DAKOTA LATER THIS AFTERNOON AS THE FIRST SUBTLE WAVE EJECTS OUT OF NORTHERN WYOMING IN SOUTHWEST FLOW. ANY CONVECTION WILL REMAIN ELEVATED...LIMITING MOISTURE POTENTIAL. THE REST OF THE FORECAST WILL BE DOMINATED BY THE BROAD UPPER LOW THAT SITS AND SPINS OVER THE INTERMOUNTAIN WEST. THIS FEATURE WILL EJECT A SECOND WAVE NORTHWARDS OVERNIGHT. WHILE THERE IS LITTLE UPPER SUPPORT...A STALLED FRONT/INVERTED SURFACE TROF WILL PROVIDE THE FOCUS FOR CONVECTION AS A 50KT LOW LEVEL JET FORMS OVER THE PLAINS.CAPE VALUES WILL RANGE SOMEWHERE BETWEEN 400 AND 1000 J/KG...WITH PWATS EXCEEDING 1 INCH. CONVECTION WILL LIKELY MOVE NORTH/NORTHEAST...SO THE MAIN REGION RECEIVING MOISTURE OVERNIGHT IS WESTERN AND NORTH CENTRAL SOUTH DAKOTA. THE NEXT WEAK WAVE DRIFTS ACROSS CENTRAL AND EASTERN SOUTH DAKOTA LATE FRIDAY. NOT MUCH LIFT WITH THIS FEATURE...A LOCAL BULLSEYE OF AROUND 15 MICROBARS...SO SOME SPOTTY LIGHT PRECIPITATION COULD ADVECT INTO EASTERN COUNTIES BUT WITH LITTLE IF ANY MUCAPE CONVECTION WILL BE RATHER WEAK. A MORE IMPRESSIVE WAVE TO THE SOUTH WILL PROBABLY BE THE DOMINANT FEATURE THANKS TO DIFFLUENT FLOW ALOFT. PROFILES REMAIN MOIST ADIABATIC BUT WITH SOME ELEVATED CAPE...AND PWATS NEARING 3 STANDARD DEVIATIONS ABOVE CLIMO. SREF PROBABILITIES FOR A HALF TO 1 INCH ARE BETWEEN 70 AND 30 PERCENT RESPECTIVELY...WITH THE FOCUS REMAINING ACROSS SOUTH CENTRAL SOUTH DAKOTA AND EXTENDING NORTH/NORTHEAST WHILE VALUES DROP. THE FINAL SURGE IN MOISTURE AHEAD OF THE LAST WAVE IS EXPECTED FOR LATE SATURDAY. WHILE PROFILES ARE COOLER...MUCH OF THE CWA WILL REMAIN MILD ENOUGH FOR RAIN...WHICH SHOULD BE BECOMING LESS INTENSE AS IT HEADS INTO THE CWA AS THE WAVE IS EXPECTED TO WEAKEN. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 257 PM CDT THU APR 14 2016 A DEEP UPPER LEVEL TROUGH OVER THE ROCKY MOUNTAIN REGION WILL TRANSITION TO A CUTOFF LOW OVER THE FOUR CORNERS AREA ON SUNDAY...WITH WEAK RIDGING SETTING UP OVER THE NORTHERN PLAINS. AT THE SURFACE...AN INVERTED TROUGH WILL EXTEND FROM TEXAS TO NORTHWESTERN WISCONSIN SUNDAY MORNING...WITH PRECIPITATION BEHIND IT LINGERING OVER PARTS OF THE CWA. THE BIG QUESTION BECOMES HOW QUICKLY THE PRECIPITATION EXITS THE AREA AS HIGH PRESSURE DROPS IN FROM THE NORTH. THE GFS IS SLOWER WITH THIS THAN THE ECMWF...SO WILL STICK WITH GENERAL BLEND AND KEEP A CHANCE GOING SUNDAY AND MONDAY BEFORE PUSHING THE PRECIPITATION SOUTH ON TUESDAY AND OUT OF THE AREA TUESDAY NIGHT. THE REMAINDER OF THE PERIOD WILL BE DRY UNDER THE INFLUENCE OF THE SURFACE HIGH. WITH ABUNDANT CLOUD COVER AND POTENTIAL PRECIPITATION...TEMPERATURES WILL BE A BIT COOL EARLY IN THE PERIOD...WITH HIGHS MAINLY IN THE 50S SUNDAY AND MONDAY. WILL THEN SEE A GRADUAL WARMING TREND WITH HIGHS IN THE 60S TUESDAY AND WEDNESDAY...AND IN THE UPPER 60S TO LOWER 70S ON THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1229 PM CDT THU APR 14 2016 FOR THE MOST PART...VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE TAF PERIOD. SCATTERED TO WIDESPREAD RAIN SHOWERS WILL MOVE INTO THE WESTERN AND CENTRAL CWA LATE TONIGHT AND CONTINUE INTO FRIDAY MORNING. A FEW THUNDERSTORMS ARE POSSIBLE ACROSS THE WEST TONIGHT AS WELL. VSBYS MAY FALL INTO THE MVFR CATEGORY AT TIMES WITH THE PRECIPITATION. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR SDZ272-273. MN...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ039-046. && $$ SHORT TERM...CONNELLY LONG TERM...PARKIN AVIATION...PARKIN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1232 PM CDT THU APR 14 2016 .UPDATE... ISSUED AT 1229 PM CDT THU APR 14 2016 SEE UPDATED AVIATION DISCUSSION BELOW. UPDATE ISSUED AT 941 AM CDT THU APR 14 2016 UPDATE IS TO EXPAND RED FLAG HEADLINES INTO EASTERN SOUTH DAKOTA. A PLUME OF HIGHER DEW POINT AIR IS HEADED IN FROM THE SOUTH TODAY...HOWEVER BEFORE IT ARRIVES BOTH THE 12Z NAM AND 06Z GFS SUGGEST THAT THERE IS A POCKET OF MUCH DRIER AIR LOCATED AROUND 850-750MB...CO LOCATED WITH THE CORE OF WARMEST AIR. AS THIS MIXES OUT...HRRR AND RUC DEW POINTS DROP TO THE UPPER 30S/LOW 40S. THUS...WITH A SLIGHT NUDGE OF HIGHS INTO THE LOW 80S FOR THE COTEAU...AFTERNOON RH VALUES COULD DROP DOWN TO CRITERIA. THE WIND FORECAST REMAINS THE SAME WITH GUSTS TO AROUND 30MPH. NO OTHER CHANGES FOR THIS MORNING UPDATE. && .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 403 AM CDT THU APR 14 2016 FIRE WEATHER CONCERNS TODAY...AND PCPN CHANCES THROUGHOUT THE PERIOD WILL BE THE FORECAST CHALLENGES. A WEAK SURFACE TROUGH AND UPPER LEVEL SHORTWAVE IS CURRENTLY LIFTING NORTHEASTWARD ACROSS THE WESTERN DAKOTAS. THIS SYSTEM IS PRODUCING LIGHT PCPN...MAINLY ACROSS NORTH DAKOTA. WHILE THE UPPER LEVEL LIFT WILL DEPART THE REGION TODAY...A STALLED FRONTAL BOUNDARY MAY BECOME THE FOCUS FOR ADDITIONAL PCPN CHANCES THIS AFTERNOON IN NORTH CENTRAL SD. AS FOR FIRE WEATHER...MOST OF THE CWA WILL SEE VERY WARM TEMPERATURES WITH HIGHS REACHING THE LOW 80S. A STRENGTHENING LOW PRESSURE SYSTEM WEST OF THE REGION WILL PRODUCE GUSTY SOUTHERLY WINDS FOR THE EASTERN HALF OF THE CWA. WHILE WINDS SUPPORT A FIRE WEATHER HEADLINE...INCREASING MOISTURE FROM THE SOUTH COULD KEEP RH VALUES FROM FALLING BELOW 25 PERCENT. WILL FORGO ISSUING A FIRE WEATHER HEADLINE FOR SD...BUT WILL ISSUE ONE FOR OUR MINNESOTA COUNTIES. AN UPPER LEVEL CLOSED LOW AT 500 MB CURRENTLY IMPACTING THE PAC NW...WILL BE OUR NEXT WEATHER SYSTEM. THIS SYSTEM WILL BECOME A DEEP TROUGH OVER THE WESTERN HALF OF THE US...WHICH WILL PRODUCE DECENT SOUTHERLY FLOW OF MOISTURE INTO THE NORTHERN PLAINS. INTEGRATED WATER VAPOR TRANSPORT IN NOT REAL GREAT WITH THE FIRST WAVE OF PCPN TONIGHT THROUGH FRIDAY. GENERALLY EXPECTING LIGHT TO MODERATE SHOWERS WITH SOME THUNDERSTORMS. THE INTEGRATED WATER VAPOR TRANSPORT IS BEST FRIDAY NIGHT INTO SATURDAY MORNING WHEN THE GULF OF MEXICO COULD BE OPEN. THIS TIME PERIOD IS WHEN THE SREF INDICATES THE BEST POTENTIAL OF SEEING 0.25 INCHES OF QPF IN A 6 HOUR PERIOD. THANKFULLY A GOOD 1 TO 3 INCHES OF RAINFALL OVER THE COURSE OF A COUPLE OF DAYS IS NEEDED. .LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY) ISSUED AT 403 AM CDT THU APR 14 2016 NOT MUCH CHANGE FROM THE PREVIOUS FORECAST IN THE EXTENDED. A DEEP UPPER TROUGH WILL TRANSITION INTO A CUTOFF LOW BY SUNDAY/MONDAY. GFS AND ECMWF DIFFER SLIGHTLY IN PLACEMENT OF THE UPPER LOW WITH THE GFS A LITTLE FARTHER NORTH. THIS DISCREPANCY WILL IMPACT TIMING OF PRECIP EXIT. SFC HIGH PRESSURE WILL MOVE DOWN FROM THE NORTH BRINGING IN MUCH DRIER AIR WHICH WILL SET UP A SHARP GRADIENT OF RAIN/NO RAIN. BY TUESDAY NIGHT RIDGING ALOFT WILL TAKE HOLD AND ALL PRECIP WILL EXIT. TEMPS WILL TREND UPWARD THROUGH THE PERIOD WITH HIGHS IN THE 50S ON SUNDAY UNDER THE UPPER TROUGH CLIMBING TOWARD 70 BY WED AS THE RIDGE BUILDS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1229 PM CDT THU APR 14 2016 FOR THE MOST PART...VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE TAF PERIOD. SCATTERED TO WIDESPREAD RAIN SHOWERS WILL MOVE INTO THE WESTERN AND CENTRAL CWA LATE TONIGHT AND CONTINUE INTO FRIDAY MORNING. A FEW THUNDERSTORMS ARE POSSIBLE ACROSS THE WEST TONIGHT AS WELL. VSBYS MAY FALL INTO THE MVFR CATEGORY AT TIMES WITH THE PRECIPITATION. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR SDZ272-273. MN...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ039-046. && $$ UPDATE...CONNELLY SHORT TERM...SD LONG TERM...WISE AVIATION...PARKIN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
126 PM CDT THU APR 14 2016 .UPDATE... FOR 18Z AVIATION DISCUSSION. && .DISCUSSION... SURFACE OBS THIS MORNING SHOW AN INVERTED TROUGH IN PLACE ACROSS MIDDLE TENNESSEE WITH SOUTHEAST WINDS AND DEWPOINTS IN THE UPPER 40S/50S ACROSS SOUTHEAST ZONES VERSUS NORTHEAST WINDS AND MUCH LOWER DEWPOINTS IN THE FAR NORTHWEST. RADAR SHOWS SCATTERED SHOWERS CONTINUED OVER THE SOUTHEAST TWO-THIRDS OF THE CWA...AND MODELS INCLUDING THE HRRR AND NAM SHOW AN INCREASE IN SHOWER ACTIVITY THIS AFTERNOON AREAWIDE. HAVE ADJUSTED POPS/TEMPS SLIGHTLY BASED ON LATEST OBS AND TRENDS. CANNOT RULE OUT AN ISOLATED THUNDERSTORM TODAY OVER WESTERN ZONES...BUT BETTER CHANCE FOR STORMS WILL BE WEST OF OUR FORECAST AREA CLOSER TO CENTER OF UPPER LOW. && .AVIATION... 18Z TAF DISCUSSION. EXPECT TO SEE SCATTERED SHOWERS WORKING UP THROUGH MIDDLE TENNESSEE THIS AFTERNOON AND INTO THE EVENING AND CAN`T RULE OUT A RUMBLE OR TWO OF THUNDER. H-TRIPLE-R HAS ACTIVITY MOSTLY NORTH OF THE MID STATE BY MIDNIGHT. BASICALLY KEPT TERMINALS VFR EXCEPT AFTER MIDNIGHT WHERE THEY WILL GO DOWN INTO MVFR RANGE DUE TO FOG. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM/AVIATION........01/BOYD LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1216 PM CDT THU APR 14 2016 .DISCUSSION...FOR 18Z TAFS. && .AVIATION... GREAT FLYING CONDITIONS FOR THE REST OF THE DAY INTO THE EVENING HOURS AS HIGH PRESSURE DOMINATES. WINDS WILL BE GENERALLY LIGHT AND CLOUDS FEW AND FAR BETWEEN. IT DOES LOOK LIKE ANOTHER NIGHT OF LOW CLOUDS AND FOG...LOCALLY DENSE...OVER MUCH OF THE INLAND AREAS. SEVERAL HOURS OF LIFR CONDITIONS EXPECTED AT VCT AGAIN LATE TNGT WITH LIFR ALSO PSBL AT ALI. QUICK IMPROVEMENT EXPECTED AGAIN AFTER 13-14Z. && .PREV DISCUSSION... /ISSUED 956 AM CDT THU APR 14 2016/ DISCUSSION... FOG IS DISSIPATING QUICKLY AND THE ADVISORY HAS BEEN CANCELLED A LITTLE EARLY. MADE A FEW MODIFICATIONS TO THE HOURLY GRIDS BUT OVERALL THE PREV FCST APPEARS IN GREAT SHAPE WITH A WARM AND SLIGHTLY LESS HUMID AFTERNOON IN STORE FOR THE REGION. PREV DISCUSSION... /ISSUED 620 AM CDT THU APR 14 2016/ DISCUSSION...PLEASE SEE 12Z AVIATION DISCUSSION BELOW. CONCERNING DENSE FOG...EXPANDED DENSE FOG ADV FOR NORTHERN COASTAL BEND AS VSBYS CONTINUE TO LOWER THERE. ALSO ADDED WEBB AND DUVAL COUNTY TO ADVISORY. 11 TO 3.9 MICROMETER SATELLITE IMAGERY INDICATES FOG DEVELOPING ACROSS NORTHERN HALVES OF WEBB/DUVAL COUNTIES AND SLOWLY SPREADING SOUTH. FOG MAY NOT MAKE IT INTO CITY OF LAREDO...BUT IT WILL BE CLOSE. /HART/. AVIATION...POOR FLIGHT RULES EARLY THIS MRNG WITH RAPID IMPROVEMENT TO VFR AROUND MID MRNG. AS OF WRITING....AREAS OF FOG CONTINUE TO DVLP ACROSS S TX WITH VLIFR CONDITIONS XPCTD AT BEGINNING OF TAF PERIOD AT KVCT...WITH FOG POSSIBLY DVLPNG INTO KLRD SHORTLY AFTER 12Z. CONFIDENCE IS NOT MAJORLY HIGH WITH FG IMPACTING KLRD...BUT HIGH ENOUGH TO INCLUDE IN TAFS. KCRP MAY EXPERIENCE PATCHES OF IFR CIGS THRU MID MRNG...WITH KALI FLIRTING WITH UPPER END IFR/LOW END MVFR VSBYS. ALL TERMINALS SHOULD RETURN TO VFR WITH MAINLY CLEAR SKIES BY MID/LATE MRNG WITH VFR THEN PREVAILING THE REST OF TODAY. ADDITIONAL FG/CIGS/POOR FLIGHT RULES POSSIBLE AT KVCT/KLRD/KALI LATE TONIGHT. LIGHT NRLY SFC WINDS AROUND 10 KTS GRADUALLY BECMG ESERLY BY LATE IN THE DAY. PREV DISCUSSION... /ISSUED 533 AM CDT THU APR 14 2016/ DISCUSSION...AFTER COLLABORATING WITH EWX...DECIDED TO ISSUE A DENSE FOG ADVISORY FOR AREAS FROM LA SALLE COUNTY EASTWARD TO VICTORIA COUNTY. VISIBILITIES PREVAILING AT 1/4 MILE AT KVCT WITH MILITARY SITES ACROSS RURAL AREAS OF MCMULLEN COUNTY ALSO REPORTING DENSE FOG. SREF...NARRE-TL...AND HRRR RUNS INDICATE DENSE FOG EXPANDING IN AREAL COVERAGE THROUGH SUNRISE...AND THEN PERSISTING UNTIL 14/15Z. GIVEN HIGH SOIL MOISTURE CONTENT FROM RECENT RAINFALL AND LIGHT WIND SPEEDS /WITH DRY AIR ALOFT/...I SEE NO REASON TO DISCOUNT GUIDANCE. /HART/. PREV DISCUSSION... /ISSUED 419 AM CDT THU APR 14 2016/ SHORT TERM (TODAY THROUGH FRIDAY)...WEAK NNE SFC WINDS EARLY THIS MORNING HAVE PRECLUDED MUCH IN THE WAY OF FOG FORMATION AS OF WRITING. HOWEVER...WITH EXPECTED SFC WINDS WEAKENING EVEN FURTHER SUNRISE...FEEL THAT A PERIOD OF FOG WILL BE POSSIBLE ACROSS PORTIONS OF INLAND S TX FOR A FEW HOURS LATE TONIGHT. OTHERWISE...ANY MORNING CLOUDINESS/FOG SHOULD QUICKLY MIX OUT BY MID MORNING WITH MOSTLY SUNNY SKIES PREVAILING TODAY. VERY DRY ATMOSPHERIC COLUMN ALOFT SHOULD RESULT IN A RAPID WARMUP TODAY. A LITTLE UNSURE AS TO HOW MUCH MIXING WILL OCCUR...BUT ALL IN ALL IT SHOULD FEEL EVEN LESS HUMID THAN YESTERDAY. MAX TEMPS WILL GENERALLY BE IN THE 80S...BUT HAVE UNDERCUT GUIDANCE BY A FEW DEGREES ACROSS NORTHERN TIER OF COUNTIES WHERE WETTER SOILS SHOULD SLIGHTLY LIMIT MAX HEATING POTENTIAL. WEAK MOISTURE ADVECTION TONIGHT MAY ALLOW MIN TEMPS ALONG THE RIO GRANDE TO BE A FEW DEGREES HIGHER THAN THIS MORNING/S VALUES...BUT TONIGHT SHOULD STILL FEEL RELATIVELY COMFORTABLE IF OUTDOORS. H85 TEMPS ARE PROG TO INCREASE A COUPLE OF DEGREES FRIDAY AND AS SUCH I HAVE GONE A COUPLE OF DEGREES WARMER FOR MAX TEMPS...MAINLY OVER THE BRUSH COUNTRY /MORE ESERLY WIND DIRECTION ACROSS THE EAST MAY ALLOW TEMPS TO BE A DEGREE OR TWO COOLER THAN TODAY/...WITH CONTINUED DRY AIR ALOFT RESULTING IN MOSTLY SUNNY SKIES. LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...THE DETERMINISTIC GFS/ECMWF/NAM CONTINUE TO PREDICT AN UPPER LEVEL LOW TO DEVELOP OVER THE WRN CONUS EARLY IN THE PERIOD. THIS SYSTEM IS PREDICTED TO REMAIN QUASI-STATIONARY OVER THE SWRN CONUS/FOUR CORNERS REGION SATURDAY/SUNDAY. INCREASING ONSHORE FLOW IS EXPECTED OVER THE CWA/MSA IN RESPONSE TO THIS SYSTEM WITH PWAT VALUES ABOVE NORMAL BY SATURDAY AFTN (GFS DETERMINISTIC) AND SCEC/SCA CONDITIONS OVER THE COASTAL WATERS LATE SATURDAY/SUNDAY. ANTICIPATE THAT INCREASING MSTR WL CONTRIBUTE TO ISOLD/SCT CONVECTION OVER THE CWA SATURDAY. DYNAMICS ASSOCIATED WITH THE UPPER SYSTEM IS EXPECTED TO RESULT IN SCATTERED/NUMEROUS CONVECTION OVER THE CWA/MSA SUNDAY/MONDAY. CONDITIONS MIGHT BE FAVORABLE FOR STRONG/SEVERE THUNDERSTORMS GIVEN THAT THE GFS DETERMINITIC PREDICT BRN VALUES IN THE SUPERCELLULAR RANGE OVER THE ERN CWA SUNDAY/MONDAY AFTN. THE UPPER LOW IS PREDICTED TO BREAKDOWN TUESDAY/WEDNESDAY (PER ECMWF/GFS DETERMINISTIC AND SUGGESTED BY THE GFS ENSEMBLE MEAN.) YET...PWAT VALUES ARE PREDICTED TO REMAIN ABOVE NORMAL TUESDAY/WEDNESDAY (GFS DETERMINISTIC) SUFFICIENT FOR ISOLD/SCT CONVECTON. STRONG STORMS REMAIN PSBL TUESDAY/WEDNESDAY CONSIDERING 2500-3000 J/KG CAPE VALUES PER THE GFS DETERMINISTIC. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 84 62 84 69 80 / 0 0 0 10 30 VICTORIA 83 61 82 65 79 / 0 0 0 10 30 LAREDO 87 64 90 69 86 / 0 0 0 10 30 ALICE 85 58 86 66 81 / 0 0 0 10 30 ROCKPORT 81 65 82 69 79 / 0 0 0 10 30 COTULLA 84 60 87 66 82 / 10 0 0 10 40 KINGSVILLE 85 62 85 68 81 / 0 0 0 10 30 NAVY CORPUS 82 67 81 70 79 / 0 0 0 10 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ TJ/70...AVIATION