Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/30/14


AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
732 PM PDT SAT MAR 29 2014 .UPDATE... WE`LL BE EXPIRING THE WIND ADVISORY FOR MONO CO AND THE LAKE WIND ADVISORY FOR PYRAMID LAKE WITH THIS UPDATE. REST OF THE FORECAST FOR ONGOING STORM TO REMAIN UNCHANGED AT THIS TIME. WINDS SUBSIDING ALONG HWY 395 AS COLDER AIR WORKS INTO THE REGION. GUSTS OF 30-40 MPH REMAIN LIKELY OVERNIGHT IN THESE AREAS BUT BELOW ADVISORY LEVELS. SNOW IS POURING DOWN IN THE TAHOE BASIN WITH MAJOR TRAVEL PROBLEMS OVER THE SIERRA PASSES. SNOW IS DROPPING SOUTH INTO MONO CO, PERHAPS A COUPLE HOURS SLOWER THAN EARLIER GUIDANCE HAD INDICATED. 23Z HRRR PICKED UP WELL ON TRENDS WITH SNOW AND SHOW SNOW STARTING TO TAPER OFF IN THE TAHOE BASIN BETWEEN 6-8Z. SPILLOVER INTO FAR WRN NV HAS BEEN HARD TO COME BY, BUT RADAR TRENDS IN THE PAST HOUR SHOW A SOLID BAND OF HEAVIER PRECIP WORKING INTO WRN NV THAT MAY FINALLY GET US A PERIOD OF LOWER ELEVATION RAINS FOR RENO/CARSON CITY/MINDEN. SUSANVILLE ON THE OTHER HAND WAS UNDER THE PRECIP BAND MUCH OF TODAY - WITH NEARLY 2 INCHES OF RAIN. IMPRESSIVE. UPDATED FORECAST PRODUCTS OUT SHORTLY. AM PLANNING ON ANOTHER UPDATE AROUND 9-930 PM TO TAKE A FRESH LOOK AT PRECIP TRENDS. CS && .PREVIOUS DISCUSSION... /ISSUED 308 PM PDT SAT MAR 29 2014/ SYNOPSIS... RAIN AND SNOW WILL CONTINUE THROUGH TONIGHT AS A LATE SEASON WINTER STORM MOVES ACROSS THE SIERRA. A COLDER STORM SYSTEM WILL IMPACT THE REGION MONDAY AND TUESDAY WITH LIGHT SNOW POSSIBLE IN LOWER ELEVATIONS. BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH MUCH OF THE UPCOMING WEEK, WITH ANOTHER CHANCE OF RAIN AND SNOW SHOWERS THURSDAY AND FRIDAY. SHORT TERM... PRECIPITATION CONTINUES TO INTENSIFY NEAR AND WEST OF THE SIERRA CREST AS MAIN TROUGH APPROACHES THE CALIFORNIA COAST. UPPER LEVEL JET WILL ALSO MOVE ONSHORE AND ENHANCE THE MOISTURE BAND. SNOW LEVELS EAST OF THE SIERRA CREST NEAR TAHOE HAVE REMAINED NEAR 6500-7000 FEET BUT SHOULD DROP TO LAKE LEVEL BEFORE 5 PM. SNOWFALL RATES OF 1-2 INCHES PER HOUR ARE LIKELY TO PERSIST A PERIOD OF 6-8 HOURS, AND TRAVEL IMPACTS WILL INCREASE THIS EVENING AS SNOW BEGINS ACCUMULATING ON PAVED SURFACES. THEREFORE THE WARNING WILL REMAIN IN PLACE. FARTHER NORTH INTO LASSEN COUNTY, ALTHOUGH SOME SNOW HAS ALREADY ACCUMULATED ABOVE 5500 FEET, THE HEAVIER SNOW IS ALSO EXPECTED TO END SOONER, SO THE ADVISORY SHOULD BE SUFFICIENT. LOCALIZED SNOW SHOWER BANDS MAY CONTINUE LATER TONIGHT, DEPENDING ON HOW MUCH CONVECTIVE ACTIVITY DEVELOPS IN NORTH CENTRAL CA DURING THE NEXT FEW HOURS. FOR MONO COUNTY, SNOW WILL INCREASE THIS EVENING, SPREADING SOUTHWARD ALONG THE SIERRA AND PROBABLY REACHING THE MAMMOTH LAKES VICINITY BY 8 PM. BEFORE THE SNOW ARRIVES, WINDY CONDITIONS WILL CONTINUE, SO THE ADVISORY WILL BE EXTENDED FOR A FEW MORE HOURS. SINCE ALL OF THE SNOW WILL FALL IN A COMPRESSED TIME PERIOD AND THE BAND WILL BEGIN TO WEAKEN LATE TONIGHT, SNOW TOTALS NEAR THE CREST MAY TOP OUT CLOSER TO 16 INCHES INSTEAD OF THE ORIGINAL 20 INCH PROJECTION. HOWEVER, IMPACTS WILL STILL BE SUFFICIENT TO KEEP THE WARNING IN PLACE TONIGHT. FOR WESTERN NV, THE RAIN SHADOW HAS PERSISTED SO FAR THIS AFTERNOON. HOWEVER, THE LAST FEW RUNS OF THE HRRR MODEL HAVE INDICATED RAPID SPILLOVER INTO THE RENO-CARSON VICINITY BETWEEN 4 AND 5 PM, WITH UP TO 6 HOURS OF NEARLY STEADY RAIN THROUGH THIS EVENING. IF THIS OCCURS, RAINFALL COULD STILL ADD UP TO BETWEEN 0.25 AND 0.50 INCH, WITH LOCALLY HIGHER AMOUNTS IN FOOTHILL LOCATIONS. FOR AREAS SOUTH OF HIGHWAY 50, THE MAJORITY OF THE RAIN WILL FALL DURING THE LATE EVENING AND OVERNIGHT HOURS. THE PRECIP COULD END AS SNOW BELOW 5000 FEET, BUT LITTLE OR NO SNOW ACCUMULATION IS EXPECTED IN VALLEYS. ABOVE 5000 FEET, A COUPLE INCHES MAY ACCUMULATE, BUT SOME LOCALLY HIGHER AMOUNTS MAY FALL IN DOUGLAS COUNTY AS THE COLD AIR ARRIVES IN CONJUNCTION WITH THE ONGOING HEAVIER PRECIP BAND. THIS OCCURRED WITH ONE OF THE STORMS EARLIER THIS SEASON SO THIS WOULD NEED TO BE MONITORED LATER TONIGHT. ALL GUIDANCE IS IN AGREEMENT FOR A RAPID DISSIPATION OF THE RAIN AND SNOW BY EARLY SUNDAY MORNING. FOR SUNDAY, A FEW SHOWERS MAY LINGER NEAR THE SIERRA AND IN WEST CENTRAL NV EAST OF HIGHWAY 95, OTHERWISE MOSTLY CLOUDY AND DRY CONDITIONS WILL PREVAIL WITH MODERATE WEST WINDS GUSTING TO 20-30 MPH IN THE AFTERNOON. MJD A COLDER LOW PRESSURE WILL DROP ALONG THE WEST COAST EARLY NEXT WEEK, BRINGING ADDITIONAL PRECIPITATION TO THE SIERRA AND WESTERN NEVADA. THIS LOW WILL BRING VERY COLD AIR DOWN FROM THE GULF OF ALASKA WITH 700MB NEAR -10C. SNOW LEVELS WILL FALL TO MOST VALLEY FLOORS BY MONDAY NIGHT AND INTO TUESDAY MORNING. THAT BEING SAID, THE LATEST MODEL RUNS OF THE GFS AND ECMWF HAVE BACKED OFF ON PRECIPITATION AMOUNTS IN WESTERN NEVADA, LEADING TO CONTINUED UNCERTAINTY AND LOW FORECASTER CONFIDENCE. THIS IS MAINLY BECAUSE THE LOW IS TRYING TO SPLIT OFF TO THE SOUTH AND DRIVE THE JET AND DYNAMICS WELL INTO SOUTHERN CA. THE HIGHEST CHANCES FOR SNOW WILL REMAIN IN THE SIERRA LATE MONDAY AS THE FIRST SHORTWAVE MOVES THROUGH NORTHERN CA. THE 500MB SHORTWAVE LOOKS TO BECOME NEGATIVELY TILTED, WHICH IS IS NOT NECESSARILY GOOD FOR SPILLOVER. BUT, WE SHOULD BE UNSTABLE ENOUGH FOR SOME LIGHT SPILLOVER IF THE JET REMAINS SOUTH OF MONO COUNTY. BY TUESDAY, LOW PRESSURE REMAINS OVER THE REGION WITH CONVECTIVE SHOWERS DEVELOPING UNDER THE COLD POOL. INSTABILITY LOOKS FAIRLY STRONG DUE TO THE INCREASED SOLAR HEATING. WE WILL NEED TO KEEP A CLOSE EYE, BECAUSE A SURFACE LOW DEVELOPING OVER SOUTHERN NEVADA MAY CREATE SOME LOW-LEVEL FORCING THAT COULD INCREASE PRECIPITATION RATES IN THE EASTERN SIERRA AND WESTERN NEVADA. HOON LONG TERM...WEDNESDAY THROUGH SATURDAY... FORECAST REMAINS UNCERTAIN FOR THE SYSTEM AT THE END OF NEXT WEEK. DETERMINISTIC SOLUTIONS HAVE LARGELY DIVERGED WITH THE GFS PRESENTING A SPLIT SYSTEM WILL VERY LITTLE PRECIPITATION; THE EC SHOWS A MORE CONSOLIDATED FRONT WITH LOW PRESSURE IN CENTRAL OREGON AND DECENT PRECIP ALONG THE SIERRA. THEREFORE, VERY FEW ADJUSTMENTS TO THE EXISTING FORECAST FAVORING A BLENDED APPROACH WITH 30-40% CHANCE OF PRECIP ALONG THE SIERRA FROM THURSDAY INTO SATURDAY. TEMPERATURES CONTINUE TO LOOK AROUND TO SLIGHTLY COOLER THAN SEASONAL AVERAGES WITH MODEST COLD AIR ALOFT AT 700MB AND AMPLE CLOUD COVER. HOPEFULLY SOLUTIONS WILL BEGIN TO CONVERGE OVER THE NEXT DAY OR SO TO ALLOW FOR HIGHER DETAILS. BOYD AVIATION... A CHANGEOVER TO SNOW IS EXPECTED BY 00Z AROUND THE TAHOE BASIN, WITH ABOUT 6-8 HOURS OF CIGS/VSBY BELOW LANDING MINIMUMS AT KTVL/KTRK THIS EVENING AND INTO THE LATE NIGHT. FOR KMMH, THE WORST CONDITIONS ARE LIKELY FROM 03Z-12Z FROM THIS SAME SNOW BAND. CONDITIONS WILL IMPROVE SUNDAY MORNING ALTHOUGH SOME MVFR CIGS COULD LINGER THROUGH MUCH OF THE DAY AS RESIDUAL MOISTURE REMAINS IN PLACE. FOR WESTERN NV INCLUDING KRNO-KCXP, RAIN WILL INCREASE AROUND 00Z, PRODUCING MVFR CIGS/VSBY AT TIMES FOR 4-6 HOURS THIS EVENING. THIS PRECIP MAY BRIEFLY END AS SNOW, BUT LITTLE OR NO SNOW ACCUMULATION IS EXPECTED ON RUNWAYS. VFR CONDITIONS ARE EXPECTED SUNDAY ALTHOUGH SOME MOUNTAIN OBSCURATIONS WILL REMAIN POSSIBLE DUE TO RESIDUAL CLOUD COVER. MJD && .REV WATCHES/WARNINGS/ADVISORIES... NV...WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY NVZ002. LAKE WIND ADVISORY UNTIL 8 PM PDT THIS EVENING FOR PYRAMID LAKE IN NVZ004. CA...WINTER WEATHER ADVISORY UNTIL 5 AM PDT SUNDAY ABOVE 5500 FEET FOR CAZ071. WIND ADVISORY UNTIL 8 PM PDT THIS EVENING CAZ073. WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY CAZ073. WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY CAZ072. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1123 AM PDT FRI MAR 28 2014 .SYNOPSIS...SHOWERS WILL CONTINUE ACROSS THE NORTH BAY TODAY WITH PARTLY CLOUDY SKIES FROM THE BAY AREA SOUTHWARD. RAIN WILL SLOWLY INCREASE OVER THE NORTH BAY OVERNIGHT AND THEN SPREAD SOUTHWARD THROUGH THE BAY AREA DURING THE DAY SATURDAY...REACHING THE CENTRAL COAST BY SATURDAY AFTERNOON AND EVENING. DRY WEATHER RETURNS SUNDAY AND THEN A STRONG COLD FRONT WILL ARRIVE MONDAY WITH RAIN AND GUSTY WINDS. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ON TUESDAY...DRYING WEDNESDAY AND THEN MORE RAIN POSSIBLE BY NEXT THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 9:13 AM PDT FRIDAY...SHOWERS CONTINUE ACROSS THE NORTH BAY AT THIS HOUR WITH NONE OF THE MODELS CAPTURING THE ACTIVITY...NOT EVEN THE HRRR AND RAP MODELS. FOR THE MOST PART SHOWERS ARE LIGHT AND CONFINED TO THE HILLS AND COAST BUT MT ST HELENA...MT TAMALPAIS AND WOODACRE HAVE ALL RECEIVED OVER THREE TENTHS OF AN INCH IN THE LAST 12 HOURS. ANYWAY...WILL KEEP LIGHT SHOWERS GOING THROUGH THE DAY IN THE NORTH BAY WITH DRY WEATHER FROM SAN FRANCISCO SOUTHWARD. WARM FRONTAL BOUNDARY WILL BECOME MORE ORGANIZED BY THIS EVENING IN THE VICINITY OF CAPE MENDOCINO WITH SHOWERS BECOMING STEADY RAIN OVER THE NORTH BAY TONIGHT. LIGHT SOUTH/SOUTHWEST FLOW WILL CREATE FAVORABLE UPSLOPE AS THE FRONT DRIFTS SOUTHWARD INTO THE BAY AREA BY SUNRISE SATURDAY MORNING. FOR THE MOST PART IT LOOKS LIKE A GENTLE...SOAKING RAIN WITH FAIRLY LIGHT WINDS. LATEST QPF SHOWS 1-2 INCHES FOR THE WETTEST COASTAL HILLS WITH 0.25-0.75 FOR THE VALLEYS...DRIER OF COURSE IN THE USUAL RAIN SHADOWED INLAND VALLEYS. LATEST NAM MODEL SHOWS THINGS DRYING OUT IN THE NORTH BAY BY SATURDAY AFTERNOON WHILE RAIN CONTINUES FOR MUCH OF THE DAY THROUGHOUT THE BAY AREA WITH THE HEAVIEST RAINS REACHING THE MONTEREY BAY REGION BY THE LATE AFTERNOON AND EARLY EVENING HOURS. THE FRONT WILL BE FAIRLY SLOW MOVING AS IT PASSES THROUGH OUR CWA BUT THEN QUICKLY EXIT THE REGION SATURDAY NIGHT LEAVING DRY WEATHER IN ITS WAKE FOR SUNDAY. ATTENTION WILL THEN TURN TO POTENTIALLY STRONGER SYSTEM THAT WILL ARRIVE MONDAY. LATEST TIMING BRINGS RAIN INTO THE NORTH BAY BEFORE NOON ON MONDAY AND THEN STEADY RAINS PASSING THROUGH THE BAY AREA FOR THE MONDAY AFTERNOON COMMUTE. RAINS ASSOCIATED WITH THE FRONTAL PASSAGE SHOULD BRIEFLY BE HEAVY WITH STRONG AND WELL DEFINED COLD FRONTAL BOUNDARY. STEADY RAIN WILL TURN TO SHOWERS BY MONDAY EVENING. HOWEVER THE CORE OF THE UPPER LOW WILL KEEP NUMEROUS SHOWERS AND MAYBE EVEN THUNDERSTORMS GOING FOR MUCH OF TUESDAY WITH FAVORABLE NORTHWESTERLY POST-FRONTAL SET-UP. EARLY QPF ESTIMATES WITH MONDAY/TUESDAY SYSTEM SUGGESTS 0.50-1.00 FOR THE VALLEYS AND 2 INCHES FOR THE HILLS. A BREAK IN THE WEATHER ON WEDS WITH MORE RAIN CHANCES BY NEXT THURSDAY AND FRIDAY. WILL BE UPDATING THE GRIDS WITH THE LATEST THINKING FOR THE AFTERNOON PACKAGES. && .AVIATION...AS OF 11:05 AM PDT FRIDAY...DOPPLER RADAR SHOWS RAIN SHOWERS CONTINUE TO MOVE ACROSS THE NORTH BAY THIS MORNING. SHOWERS WILL TAPER THIS AFTERNOON BEFORE THE NEXT WAVE OF RAIN HITS THE AREA SATURDAY. MID AND UPPER LEVEL CLOUDS WILL CONTINUE TO STREAM IN ACROSS THE REGION AHEAD OF THE APPROACHING COLD FRONT WITH WINDS EXPECTED TO VEER INCREASINGLY TO THE SOUTH AS THE DAY PROGRESSES. RAIN IS ANTICIPATED TO BEGIN IN THE NORTH BAY AFTER MIDNIGHT TONIGHT...SPREADING SOUTH ACROSS THE REGION THROUGH THE MORNING. MODERATE CONFIDENCE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...VFR...GENERALLY LIGHT SOUTHERLY WINDS ARE EXPECTED TO PREVAIL THOUGH MUCH OF THE FORECAST PERIOD. WINDS WILL BECOME SOUTHWESTERLY BY EARLY AFTERNOON AS THE COLD FRONT GETS CLOSER TO THE COAST. MODERATE CONFIDENCE. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: RWW AVIATION: CW VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
913 AM PDT FRI MAR 28 2014 .SYNOPSIS...SHOWERS WILL CONTINUE ACROSS THE NORTH BAY TODAY WITH PARTLY CLOUDY SKIES FROM THE BAY AREA SOUTHWARD. RAIN WILL SLOWLY INCREASE OVER THE NORTH BAY OVERNIGHT AND THEN SPREAD SOUTHWARD THROUGH THE BAY AREA DURING THE DAY SATURDAY...REACHING THE CENTRAL COAST BY SATURDAY AFTERNOON AND EVENING. DRY WEATHER RETURNS SUNDAY AND THEN A STRONG COLD FRONT WILL ARRIVE MONDAY WITH RAIN AND GUSTY WINDS. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ON TUESDAY...DRYING WEDNESDAY AND THEN MORE RAIN POSSIBLE BY NEXT THURSDAY AND FRIDAY. && .DISCUSSION...AS OF 9:13 AM PDT FRIDAY...SHOWERS CONTINUE ACROSS THE NORTH BAY AT THIS HOUR WITH NONE OF THE MODELS CAPTURING THE ACTIVITY...NOT EVEN THE HRRR AND RAP MODELS. FOR THE MOST PART SHOWERS ARE LIGHT AND CONFINED TO THE HILLS AND COAST BUT MT ST HELENA...MT TAMALPAIS AND WOODACRE HAVE ALL RECEIVED OVER THREE TENTHS OF AN INCH IN THE LAST 12 HOURS. ANYWAY...WILL KEEP LIGHT SHOWERS GOING THROUGH THE DAY IN THE NORTH BAY WITH DRY WEATHER FROM SAN FRANCISCO SOUTHWARD. WARM FRONTAL BOUNDARY WILL BECOME MORE ORGANIZED BY THIS EVENING IN THE VICINITY OF CAPE MENDOCINO WITH SHOWERS BECOMING STEADY RAIN OVER THE NORTH BAY TONIGHT. LIGHT SOUTH/SOUTHWEST FLOW WILL CREATE FAVORABLE UPSLOPE AS THE FRONT DRIFTS SOUTHWARD INTO THE BAY AREA BY SUNRISE SATURDAY MORNING. FOR THE MOST PART IT LOOKS LIKE A GENTLE...SOAKING RAIN WITH FAIRLY LIGHT WINDS. LATEST QPF SHOWS 1-2 INCHES FOR THE WETTEST COASTAL HILLS WITH 0.25-0.75 FOR THE VALLEYS...DRIER OF COURSE IN THE USUAL RAIN SHADOWED INLAND VALLEYS. LATEST NAM MODEL SHOWS THINGS DRYING OUT IN THE NORTH BAY BY SATURDAY AFTERNOON WHILE RAIN CONTINUES FOR MUCH OF THE DAY THROUGHOUT THE BAY AREA WITH THE HEAVIEST RAINS REACHING THE MONTEREY BAY REGION BY THE LATE AFTERNOON AND EARLY EVENING HOURS. THE FRONT WILL BE FAIRLY SLOW MOVING AS IT PASSES THROUGH OUR CWA BUT THEN QUICKLY EXIT THE REGION SATURDAY NIGHT LEAVING DRY WEATHER IN ITS WAKE FOR SUNDAY. ATTENTION WILL THEN TURN TO POTENTIALLY STRONGER SYSTEM THAT WILL ARRIVE MONDAY. LATEST TIMING BRINGS RAIN INTO THE NORTH BAY BEFORE NOON ON MONDAY AND THEN STEADY RAINS PASSING THROUGH THE BAY AREA FOR THE MONDAY AFTERNOON COMMUTE. RAINS ASSOCIATED WITH THE FRONTAL PASSAGE SHOULD BRIEFLY BE HEAVY WITH STRONG AND WELL DEFINED COLD FRONTAL BOUNDARY. STEADY RAIN WILL TURN TO SHOWERS BY MONDAY EVENING. HOWEVER THE CORE OF THE UPPER LOW WILL KEEP NUMEROUS SHOWERS AND MAYBE EVEN THUNDERSTORMS GOING FOR MUCH OF TUESDAY WITH FAVORABLE NORTHWESTERLY POST-FRONTAL SET-UP. EARLY QPF ESTIMATES WITH MONDAY/TUESDAY SYSTEM SUGGESTS 0.50-1.00 FOR THE VALLEYS AND 2 INCHES FOR THE HILLS. A BREAK IN THE WEATHER ON WEDS WITH MORE RAIN CHANCES BY NEXT THURSDAY AND FRIDAY. WILL BE UPDATING THE GRIDS WITH THE LATEST THINKING FOR THE AFTERNOON PACKAGES. && .AVIATION...AS OF 4:40 AM PDT FRIDAY...A MIX OF SUN AND CLOUDS WILL PASS OVER THE TERMINALS TODAY WITH A STRAY SHOWER POSSIBLE AS A COLD FRONT APPROACHES THE CENTRAL CALIFORNIA COAST. SHOWERS ARE EXPECTED IN THE SANTA ROSA AREA TODAY WITH RAIN HITTING THE SAN FRANCISCO BAY AREA AFTER MIDNIGHT. VICINITY OF KSFO...VFR...GENERALLY LIGHT SOUTHERLY WINDS ARE EXPECTED TO PREVAIL THIS MORNING. WINDS WILL BECOME SOUTHWEST BY EARLY AFTERNOON AS THE COLD FRONT GETS CLOSER TO THE COAST. A PASSING SHOWER WILL BE POSSIBLE THIS MORNING WITH LIGHT RAIN EXPECTED TO BEGIN AFTER MIDNIGHT. MODERATE CONFIDENCE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR...GENERALLY LIGHT SOUTHERLY WINDS ARE EXPECTED TO PREVAIL THIS MORNING. WINDS WILL BECOME SOUTHWESTERLY BY EARLY AFTERNOON AS THE COLD FRONT GETS CLOSER TO THE COAST. MODERATE CONFIDENCE. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: RWW AVIATION: LARRY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS EUREKA CA
906 AM PDT FRI MAR 28 2014 .SYNOPSIS...RAIN WILL CONTINUE TO SPREAD SOUTH TODAY AS AN ATMOSPHERIC RIVER SLOWLY MOVES SOUTH OVER THE AREA. RAIN WILL TAPER TO SHOWERS LATE TONIGHT AND BRING A SLIGHT CHANCE OF A THUNDERSTORM AND SMALL HAIL ON SUNDAY. && .UPDATE...RAIN HAS SPREAD SOUTH A BIT SLOWER THAN EXPECTED TODAY...AT LEAST IN THE LOW ELEVATIONS. MODERATE TO THE HIGHER ELEVATIONS HAVE BEEN GETTING SIGNIFICANT RAINFALL AS EXPECTED. COOSKIE MOUNTAIN NEAR CAPE MENDOCINO HAS GOTTEN 1.40 INCHES AS OF 8 AM. RAIN IS STILL EXPECTED IN THE EUREKA AREA...BUT IT WILL START A BIT LATER AND AMOUNTS WILL BE A LOWER THAN PREVIOUSLY EXPECTED. MKK && .PREV DISCUSSION......ISSUED AT 400 AM PDT... SHORT TERM (TODAY THROUGH TUESDAY)...MADE SLIGHT ADJUSTMENTS TO THE EARLY MORNING FORECAST TO SLOW THE SOUTHERN PROGRESSION OF THE FRONT BY A COUPLE HOURS. THE ONLY NOTICEABLE CHANGE WILL BE FOR SOUTHERN MENDOCINO COUNTY THIS MORNING. OTHERWISE LEFT THE FORECAST NEARLY THE SAME FOR TODAYS RAIN. THE MAIN FORECAST MODELS, THE GFS AND NAM, CONTINUE TO SHOW THE ONSET OF STEADY RAIN BETWEEN 12Z AND 18Z. HOWEVER, THE SHORT TERM RUC HOLDS OFF THE ONSET UNTIL ABOUT 18Z TO 19Z. REGARDLESS, PERIODS OF LIGHT RAIN ARE EXPECTED AHEAD OF THE FULL ONSET OF THE ATMOSPHERIC RIVER RAINS, SO HAVE LEFT THE 100 POPS FOR THE EARLY MORNING HOURS. LOOKING AT THE GEFS IVT MEAN VS THE OP GFS IVT FROM THE 12Z RUN YESTERDAY AND THERE APPEARS TO BE A BIT OF WIGGLE ROOM IN THE EXACT LANDING OF THE AR HEAD. THE GEFS MEAN TAKES THE BULK OF THE IVT INTO SRN ORE WHILE THE OP GFS BRINGS IT INTO FAR NORTHERN CAL. CAN NOT FIND ENOUGH EVIDENCE TO LOWER QPF AMOUNTS, BUT AS THE DAY GOES ON WE MAY NEED TO ADJUST THE QPF DOWNWARD SLIGHTLY. THIS WILL DEPEND ON WHERE THE HEAD OF THE AR HITS. SNOW LEVELS WILL REMAIN AROUND 6KFT TODAY WITH ONLY THE HIGHEST PEAKS RECEIVING ANY SNOW. THE COLD FRONT STEERING TODAYS AR WILL SLOWLY SINK TO THE SOUTH THROUGH THE DAY AND OVERNIGHT. AN UNSTABLE COOL AIR MASS WITH LOWERING HEIGHTS WILL FILL IN BEHIND THE FRONT. A POST FRONTAL TROUGH WILL BRING INSTABILITY ASSOCIATED WITH A VORT MAX TO THE REGION ON SATURDAY AS THE TROUGH APPROACHES. MODELS ARE SHOWING INCREASING CAPE AND LOWERING LI`S WITH THIS VORT MAX. WITH FAIRLY WARM AIR IN PLACE AT THE SURFACE AND COOLING AIR ALOFT, THE INGREDIENTS SHOULD BE PRESENT FOR WIDESPREAD CONVECTIVE SHOWERS ACROSS NWCA. THERE IS A SLIGHT CHANCE SOME OF THESE SHOWERS WILL BE THUNDERSTORMS, PRODUCING SMALL HAIL AND LOCALLY GUSTY WINDS. THE NAM IS SHOWING A THIN CAPE PROFILE FOR MUCH OF THE AREA ON SAT WITH VALUES IN THE FEW HUNDRED J/KG. THE TOP OF THE CONVECTION COULD REACH AS HIGH AS 22KFT WITH A TEMP OF -37C. THIS SHOULD PROVIDE ENOUGH DEPTH TO PRODUCE SMALL HAIL. FOR THE FORECAST, WENT AHEAD AND MATCHED THE NEIGHBORS AND EXPANDED THE SLIGHT CHANCE OF TSTMS ACROSS THE ENTIRE CWA. SPC CONTINUES TO SHOW NWCA IN THE THUNDERLINE FOR SAT. SUNDAY BROUGHT SOME SIGNIFICANT CHANGES TO THE ONGOING FORECAST. WENT AHEAD AND BIT OFF ON THE IDEA OF A DRY DAY. SO PULLED BACK POPS TO SLIGHT CHANCE OR LESS. MONDAY HOWEVER I WENT THE OTHER WAY. MODELS HAVE BEEN CONSISTENT WITH A DIGGING UPPER LOW DIVING INTO CALIFORNIA AND BRING ANOTHER QUICK SHOT OF RAIN. CONFIDENCE IS INCREASING FOR RAIN ON MONDAY, SO WENT AHEAD AND UPPED THE POPS TO 100 FOR A SHORT TIME. THIS DIGGING LOW COULD PROVE TO VERY INTERESTING WITH SHARP COOLING ALOFT, A NEG TILTED TROUGH AXIS, AND A STRONG VORT MAX. THIS COULD BRING NWCA ANOTHER SHOT OF TSTMS AND SMALL HAIL ON MONDAY. THE OTHER ISSUE TO WATCH ON MONDAY WILL BE LOWERING SNOW LEVELS AND WIDESPREAD PRECIPITATION. THIS COULD BRING A FEW INCHES OF SNOW TO AREA PASSES BY MONDAY EVENING. MORE TO COME. TUESDAY WILL BRING THE BEGINNING OF A SHORT BREAK IN WEATHER. BFG LONG TERM (WEDNESDAY THRU FRIDAY)...WED WILL CONTINUE A SHORT BREAK IN THE WEATHER. MODELS ARE INDICATING ANOTHER UPPER TROUGH DIVING IN FOR THE SECOND HALF OF THE WEEK, BUT ARE HAVING ISSUES WITH TIMING STRENGTH. WITH A WET PATTERN EXPECTED, KEPT WITH THE IDEA OF LIKELY RAIN FOR THU THROUGH SAT. CONFIDENCE IS LOW TO MODERATE DUE TO UNCERTAINTY IN TIMING AND STRENGTH. BFG AVIATION...BREEZY SOUTHERLY WINDS WILL ACCOMPANY PERIODS OF HEAVY RAIN TODAY. EXPECT MVFR WITH PERIODS OF LIFR DURING HEAVY RAIN ACROSS THE REGION. MARINE...SOUTHERLY WINDS WILL PERSIST ACROSS THE WATERS THROUGH THE MIDDLE OF NEXT WEEK. A SERIES OF LONG PERIOD WESTERLY SWELLS WILL PROPAGATE ACROSS THE WATERS THROUGH THE MIDDLE OF NEXT WEEK. THE WINDS AND SEAS WILL INCREASE TODAY AS A COLD FRONT APPROACHES THE AREA. THE SEAS WILL REMAIN ELEVATED THROUGH THE MIDDLE OF NEXT WEEK. SMALL CRAFT ADVISORIES ARE IN EFFECT ACROSS THE WATERS THROUGH EARLY NEXT WEEK. HYDROLOGY... AN ATMOSPHERIC RIVER ACCOMPANIED BY A SLOW MOVING COLD FRONT WILL BRING COPIOUS AMOUNTS OF RAINFALL TO NORTHWEST CALIFORNIA TODAY THROUGH SATURDAY MORNING. STEADY RAIN AND OCCASIONAL PERIODS OF HEAVY RAIN CAN BE EXPECTED AS THE FRONT MOVES ACROSS THE REGION. THE HIGHER RAINFALL VALUES WILL OCCUR IN DEL NORTE COUNTY AND ALONG THE COASTAL MOUNTAIN RANGES. THE RAINFALL WILL BEGIN OVER DEL NORTE COUNTY THIS MORNING AND MOVE SOUTH ACROSS HUMBOLDT AND TRINITY COUNTIES THROUGHOUT FRIDAY AFTERNOON AND INTO MENDOCINO COUNTY FRIDAY EVENING. POTENTIAL IMPACTS: THE MAIN STEM RIVERS WILL HAVE RAPID RISES...BUT NO FLOODING IS EXPECTED. ALL THE RIVERS ARE FORECAST TO REMAIN BELOW MONITOR STAGE. THE TRIBUTARY STREAMS WILL ALSO RISE BUT ARE EXPECTED TO REMAIN WITHIN THEIR BANKS. THERE IS THE POSSIBILITY OF URBAN FLOODING DUE TO CLOGGED STORM DRAINS. AREAS WITH POOR DRAINAGE AND OTHER LOW LYING AREAS CAN EXPECT PONDING OF WATER. AFTER THE FRONT PASSES SCATTERED SHOWERS ARE EXPECTED THROUGHOUT THE DAY SATURDAY. FORECAST PRECIPITATION AMOUNTS: VALID 500 AM FRIDAY TO 500 AM SATURDAY SMITH RIVER BASIN...........3 TO 4 INCHES KLAMATH RIVER BASIN.........2 TO 3 INCHES REDWOOD CREEK BASIN.........2.5 TO 3.5 INCHES TRINITY RIVER BASIN.........2 TO 3 INCHES MAD RIVER BASIN.............2 TO 3 INCHES VAN DUZEN RIVER BASIN.......2.5 TO 3.5INCHES SF EEL RIVER BASIN..........2.5 TO 3.5 INCHES EEL RIVER BASIN.............2 TO 3 INCHES VALID FROM 1100 AM FRIDAY TO 1100 AM SATURDAY NAVARRO RIVER BASIN.........2 TO 3 INCHES RUSSIAN RIVER BASIN.........1.5 TO 2.5 INCHES && .EKA WATCHES/WARNINGS/ADVISORIES... CA...NONE. NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 9 AM PDT SUNDAY PZZ450-455-475. SMALL CRAFT ADVISORY UNTIL 4 PM PDT MONDAY PZZ470. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS EUREKA CA
400 AM PDT FRI MAR 28 2014 .SYNOPSIS...A RAINY FRIDAY IS ON TAP FOR NW CALIFORNIA AS AN ATMOSPHERIC RIVER SETS IN THIS MORNING. RAIN WILL TAPER TO SHOWERS ON SATURDAY AND BRING A SLIGHT CHANCE OF A THUNDERSTORM AND SMALL HAIL. && .SHORT TERM (TODAY THROUGH TUESDAY)...MADE SLIGHT ADJUSTMENTS TO THE EARLY MORNING FORECAST TO SLOW THE SOUTHERN PROGRESSION OF THE FRONT BY A COUPLE HOURS. THE ONLY NOTICEABLE CHANGE WILL BE FOR SOUTHERN MENDOCINO COUNTY THIS MORNING. OTHERWISE LEFT THE FORECAST NEARLY THE SAME FOR TODAYS RAIN. THE MAIN FORECAST MODELS, THE GFS AND NAM, CONTINUE TO SHOW THE ONSET OF STEADY RAIN BETWEEN 12Z AND 18Z. HOWEVER, THE SHORT TERM RUC HOLDS OFF THE ONSET UNTIL ABOUT 18Z TO 19Z. REGARDLESS, PERIODS OF LIGHT RAIN ARE EXPECTED AHEAD OF THE FULL ONSET OF THE ATMOSPHERIC RIVER RAINS, SO HAVE LEFT THE 100 POPS FOR THE EARLY MORNING HOURS. LOOKING AT THE GEFS IVT MEAN VS THE OP GFS IVT FROM THE 12Z RUN YESTERDAY AND THERE APPEARS TO BE A BIT OF WIGGLE ROOM IN THE EXACT LANDING OF THE AR HEAD. THE GEFS MEAN TAKES THE BULK OF THE IVT INTO SRN ORE WHILE THE OP GFS BRINGS IT INTO FAR NORTHERN CAL. CAN NOT FIND ENOUGH EVIDENCE TO LOWER QPF AMOUNTS, BUT AS THE DAY GOES ON WE MAY NEED TO ADJUST THE QPF DOWNWARD SLIGHTLY. THIS WILL DEPEND ON WHERE THE HEAD OF THE AR HITS. SNOW LEVELS WILL REMAIN AROUND 6KFT TODAY WITH ONLY THE HIGHEST PEAKS RECEIVING ANY SNOW. THE COLD FRONT STEERING TODAYS AR WILL SLOWLY SINK TO THE SOUTH THROUGH THE DAY AND OVERNIGHT. AN UNSTABLE COOL AIR MASS WITH LOWERING HEIGHTS WILL FILL IN BEHIND THE FRONT. A POST FRONTAL TROUGH WILL BRING INSTABILITY ASSOCIATED WITH A VORT MAX TO THE REGION ON SATURDAY AS THE TROUGH APPROACHES. MODELS ARE SHOWING INCREASING CAPE AND LOWERING LI`S WITH THIS VORT MAX. WITH FAIRLY WARM AIR IN PLACE AT THE SURFACE AND COOLING AIR ALOFT, THE INGREDIENTS SHOULD BE PRESENT FOR WIDESPREAD CONVECTIVE SHOWERS ACROSS NWCA. THERE IS A SLIGHT CHANCE SOME OF THESE SHOWERS WILL BE THUNDERSTORMS, PRODUCING SMALL HAIL AND LOCALLY GUSTY WINDS. THE NAM IS SHOWING A THIN CAPE PROFILE FOR MUCH OF THE AREA ON SAT WITH VALUES IN THE FEW HUNDRED J/KG. THE TOP OF THE CONVECTION COULD REACH AS HIGH AS 22KFT WITH A TEMP OF -37C. THIS SHOULD PROVIDE ENOUGH DEPTH TO PRODUCE SMALL HAIL. FOR THE FORECAST, WENT AHEAD AND MATCHED THE NEIGHBORS AND EXPANDED THE SLIGHT CHANCE OF TSTMS ACROSS THE ENTIRE CWA. SPC CONTINUES TO SHOW NWCA IN THE THUNDERLINE FOR SAT. SUNDAY BROUGHT SOME SIGNIFICANT CHANGES TO THE ONGOING FORECAST. WENT AHEAD AND BIT OFF ON THE IDEA OF A DRY DAY. SO PULLED BACK POPS TO SLIGHT CHANCE OR LESS. MONDAY HOWEVER I WENT THE OTHER WAY. MODELS HAVE BEEN CONSISTENT WITH A DIGGING UPPER LOW DIVING INTO CALIFORNIA AND BRING ANOTHER QUICK SHOT OF RAIN. CONFIDENCE IS INCREASING FOR RAIN ON MONDAY, SO WENT AHEAD AND UPPED THE POPS TO 100 FOR A SHORT TIME. THIS DIGGING LOW COULD PROVE TO VERY INTERESTING WITH SHARP COOLING ALOFT, A NEG TILTED TROUGH AXIS, AND A STRONG VORT MAX. THIS COULD BRING NWCA ANOTHER SHOT OF TSTMS AND SMALL HAIL ON MONDAY. THE OTHER ISSUE TO WATCH ON MONDAY WILL BE LOWERING SNOW LEVELS AND WIDESPREAD PRECIPITATION. THIS COULD BRING A FEW INCHES OF SNOW TO AREA PASSES BY MONDAY EVENING. MORE TO COME. TUESDAY WILL BRING THE BEGINNING OF A SHORT BREAK IN WEATHER. BFG .LONG TERM (WEDNESDAY THRU FRIDAY)...WED WILL CONTINUE A SHORT BREAK IN THE WEATHER. MODELS ARE INDICATING ANOTHER UPPER TROUGH DIVING IN FOR THE SECOND HALF OF THE WEEK, BUT ARE HAVING ISSUES WITH TIMING STRENGTH. WITH A WET PATTERN EXPECTED, KEPT WITH THE IDEA OF LIKELY RAIN FOR THU THROUGH SAT. CONFIDENCE IS LOW TO MODERATE DUE TO UNCERTAINTY IN TIMING AND STRENGTH. BFG && .AVIATION...BREEZY SOUTHERLY WINDS WILL ACCOMPANY PERIODS OF HEAVY RAIN TODAY. EXPECT MVFR WITH PERIODS OF LIFR DURING HEAVY RAIN ACROSS THE REGION. && .MARINE...SOUTHERLY WINDS WILL PERSIST ACROSS THE WATERS THROUGH THE MIDDLE OF NEXT WEEK. A SERIES OF LONG PERIOD WESTERLY SWELLS WILL PROPAGATE ACROSS THE WATERS THROUGH THE MIDDLE OF NEXT WEEK. THE WINDS AND SEAS WILL INCREASE TODAY AS A COLD FRONT APPROACHES THE AREA. THE SEAS WILL REMAIN ELEVATED THROUGH THE MIDDLE OF NEXT WEEK. SMALL CRAFT ADVISORIES ARE IN EFFECT ACROSS THE WATERS THROUGH EARLY NEXT WEEK. && .HYDROLOGY... AN ATMOSPHERIC RIVER ACCOMPANIED BY A SLOW MOVING COLD FRONT WILL BRING COPIOUS AMOUNTS OF RAINFALL TO NORTHWEST CALIFORNIA TODAY THROUGH SATURDAY MORNING. STEADY RAIN AND OCCASIONAL PERIODS OF HEAVY RAIN CAN BE EXPECTED AS THE FRONT MOVES ACROSS THE REGION. THE HIGHER RAINFALL VALUES WILL OCCUR IN DEL NORTE COUNTY AND ALONG THE COASTAL MOUNTAIN RANGES. THE RAINFALL WILL BEGIN OVER DEL NORTE COUNTY THIS MORNING AND MOVE SOUTH ACROSS HUMBOLDT AND TRINITY COUNTIES THROUGHOUT FRIDAY AFTERNOON AND INTO MENDOCINO COUNTY FRIDAY EVENING. POTENTIAL IMPACTS: THE MAIN STEM RIVERS WILL HAVE RAPID RISES...BUT NO FLOODING IS EXPECTED. ALL THE RIVERS ARE FORECAST TO REMAIN BELOW MONITOR STAGE. THE TRIBUTARY STREAMS WILL ALSO RISE BUT ARE EXPECTED TO REMAIN WITHIN THEIR BANKS. THERE IS THE POSSIBILITY OF URBAN FLOODING DUE TO CLOGGED STORM DRAINS. AREAS WITH POOR DRAINAGE AND OTHER LOW LYING AREAS CAN EXPECT PONDING OF WATER. AFTER THE FRONT PASSES SCATTERED SHOWERS ARE EXPECTED THROUGHOUT THE DAY SATURDAY. FORECAST PRECIPITATION AMOUNTS: VALID 500 AM FRIDAY TO 500 AM SATURDAY SMITH RIVER BASIN...........3 TO 4 INCHES KLAMATH RIVER BASIN.........2 TO 3 INCHES REDWOOD CREEK BASIN.........2.5 TO 3.5 INCHES TRINITY RIVER BASIN.........2 TO 3 INCHES MAD RIVER BASIN.............2 TO 3 INCHES VAN DUZEN RIVER BASIN.......2.5 TO 3.5INCHES SF EEL RIVER BASIN..........2.5 TO 3.5 INCHES EEL RIVER BASIN.............2 TO 3 INCHES VALID FROM 1100 AM FRIDAY TO 1100 AM SATURDAY NAVARRO RIVER BASIN.........2 TO 3 INCHES RUSSIAN RIVER BASIN.........1.5 TO 2.5 INCHES && .EKA WATCHES/WARNINGS/ADVISORIES... CA...NONE. NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 9 AM PDT SUNDAY PZZ450-455-475. SMALL CRAFT ADVISORY UNTIL 4 PM PDT MONDAY PZZ470. && $$ VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA FOLLOW US ON FACEBOOK AND TWITTER AT: HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1024 AM MDT FRI MAR 28 2014 .UPDATE... && .SHORT TERM...MIXING HAS COMMENCED...ALLOWING FOR GUSTY WESTERLY WINDS TO SPREAD OFF THE FOOTHILLS ONTO THE ADJACENT PLAINS. SOME GUSTS AROUND 45 MPH OCCURRING ACROSS PORTIONS OF THE AREA. MOUNTAIN WEB CAMS STILL INDICATING SOME LIGHT SNOW ALONG THE CONTINENTAL DIVIDE OF SUMMIT AND GRAND COUNTIES. THERE MAY ALSO BE SOME LIGHT SNOW ACROSS THE PARK AND GORE RANGES OF WESTERN JACKSON COUNTY. OVERALL THE SNOW IS SHOWING SOME SIGNS OF DECREASING AS SLIGHTLY DRIER AND MORE SUBSIDENT AIRMASS SPREADS ACROSS THE AREA. FLOW ALOFT HAS BECOME MORE NORTHWEST BEHIND THE RECENT UPPER TROUGH. LATEST MODEL CROSS SECTIONS SHOW MOISTURE DEPTH DECREASING THROUGH THE DAY...WOULD EXPECT TO SEE A CONTINUED DECREASE IN MOUNTAIN SNOW...THOUGH IT MAY BE A GRADUAL DECREASE DUE TO PERSISTENT OROGRAPHICS. ANY ADDITIONAL ACCUMULATIONS TO BE LIGHT...THOUGH SOME FAVORED WEST FACING AREAS COULD SEE UP TO AN INCH OF ADDITIONAL SNOWFALL. CURRENT FORECASTS SHOW THIS TREND...SO ONLY MINOR CHANGES EXPECTED. CURRENT WESTERLY WINDS TO SHIFT TO THE NORTHWEST BY 18Z AS MIXING CONTINUES AND SURFACE GRADIENT BECOMES NORTHWEST. LATEST RAP INDICATING MAX GUSTS AROUND 45 MPH STILL A POSSIBILITY THROUGH THE AFTERNOON... ESPECIALLY IN AND NEAR THE FOOTHILLS AND ALONG THE WYOMING BORDER. WILL MAKE SOME MINOR ADJUSTMENTS TO WIND GRIDS. WINDS STILL EXPECTED TO DECREASE THIS EVENING WITH WEAKENING GRADIENT. LATEST MODELS SHOWING SOME POTENTIAL FOR A FEW SHOWERS ACROSS THE FAR NORTHEAST PLAINS THIS AFTERNOON AS A BATCH OF MID LEVEL MOISTURE SPREADS INTO THE AREA WITH THE NORTHWEST FLOW ALOFT. LATEST RAP GENERATES LIGHT QPF IN NORTHEAST WELD...WESTERN LOGAN AND NORTHERN WASHINGTON COUNTIES BETWEEN 21Z AND 00Z. DON`T SEE ANYTHING ON SATELLITE UPSTREAM AT THIS TIME TO INDICATE SHOWERS COULD DEVELOP. WILL KEEP THINGS DRY FOR NOW BUT WILL CONTINUE TO MONITOR FOR ANY DEVELOPMENT. .AVIATION...WESTERLY WINDS FINALLY SPREADING ACROSS THE AREA... WITH KBJC ALREADY SHIFTING TO THE WEST NORTHWEST. AS MIXING CONTINUES...SHOULD SEE WINDS AT KDEN AND KAPA INCREASING BECOMING WEST NORTHWEST BY 18Z IN LINE WITH LATEST RAP AND HRRR. CURRENT TAFS SHOW THIS TREND AND WILL CONTINUE FOR THE UPCOMING ISSUANCE. SOME GUSTS TO AROUND 30 KTS STILL POSSIBLE BY 21Z. WINDS EXPECTED TO DECREASE THIS EVENING...TRANSITIONING TO A DRAINAGE FLOW. VFR TO PREVAIL WITH CEILINGS ABOVE 12000 FEET AGL. && .PREV DISCUSSION... /ISSUED 436 AM MDT FRI MAR 28 2014/ SHORT TERM...A BAND OF MODERATE TO HEAVY SNOW CONTINUES TO TRACK EAST AND SOUTHEAST OVER THE PLAINS...AND WILL BE MOVING THROUGH WASHINGTON AND NORTHEAST ELBERT COUNTIES THROUGH 5 AM. HAVE ALREADY ADJUSTED FORECAST FOR THIS SNOWFALL THROUGH SUNRISE AND HAVE EXTENDED SOME LOW POPS FOR EARLY THIS AM OUT OVER THE EASTERN BORDER OF CWA. ALREADY CLEARING SKIES FURTHER WEST TOWARDS THE FRONT RANGE AS SUBSIDENCE STARTING TO KICK IN AS UPPER LEVEL TROF MOVES OVER THE STATE WITH MAIN CIRCULATION NOTED OVER NORTHEAST WYOMING. DRYING NOTED IN WATER VAPOR IMAGERY OVER SOUTHERN WYOMING AS GUSTY NORTHWEST WINDS ALREADY DEVELOPING OVER CYS AND SOUTHERN PORTIONS OF SOUTHERN WYOMING. SHOULD SEE WINDS SPREADING OVER THE FRONT RANGE FOOTHILLS FROM 10Z-15Z. STILL SOME OROGRAPHIC INDUCED SNOW SHOWERS ONGOING OVER THE HIGHER MOUNTAINS BUT SHOULD SEE A DIMINISH OF THE SHOWERS AS THE DAY WEARS ON AS HIGH PRESSURE RIDGE BUILDS IN. WINDS WILL BE INCREASING ON THE PLAINS THIS AFTERNOON AS LOW LEVELS OF AIRMASS MIX OUT TO NEAR 500MB UNDER SUBSIDENT AIRMASS. COULD SEE SOME GUSTS UP AROUND 30KT. WINDS WILL DIMINISH ON THE PLAINS THIS EVENING AS AIRMASS DECOUPLES. WILL SEE A CONTINUATION OF THE WINDS IN THE MOUNTAINS AND FOOTHILLS TONIGHT AS CROSS SECTIONS SHOW CROSS BARRIER FLOW AROUND 30KT. TEMPERATURES WILL BE SLIGHTLY COOLER TODAY BEHIND THE TROF BUT COOLING MITIGATED BY THE STRONGER DOWNSLOPE FLOW. LONG TERM...STRONG UNDULATING UPPER LEVEL ZONAL ZONE WILL REMAIN OVER THE WESTERN HALF OF THE COUNTRY THROUGH THE FORESEEABLE FUTURE ACCORDING THE LATEST MODEL OUTPUT. WE BEGIN WITH A SHORTWAVE RIDGE WHICH MODELS PROPAGATE ACROSS THE CENTRAL ROCKY MOUNTAIN REGION THIS WEEKEND. AMBIENT AIRMASS WARMS AND BECOMES STRONGLY CAPPED AT MID-LEVEL ON SATURDAY AS THE FRONT SIDE OF THIS RIDGE MOVES ACROSS THE FORECAST AREA. SATURDAY MAY NOT BE THE WARMEST OF THE TWO DAYS...BUT PROBABLY THE SUNNIEST. MEANWHILE WIDESPREAD PRESSURE FALLS ACROSS THE NORTHERN GREAT PLAINS ON SATURDAY WILL HELP TO ENHANCE THE DOWNSLOPE GRADIENT FLOW ALONG AND EAST OF THE COLORADO FRONT RANGE DURING THE DAY. BY MID- AFTERNOON COULD SEE SOUTHWEST WINDS GUSTING TO AROUND 25KTS ALONG THE PALMER DIVIDE FROM WESTERN ELBERT TO LINCOLN COUNTIES. IN ADDITION...MIN RELATIVE HUMIDITY VALUES COULD FALL TO AS LOW AS 15 PCT WITH LATE DAY TEMPERATURES IN THE MID TO UPPER 60S. SHOULD LATER MODEL RUNS INDICATE STRONGER WINDS AND/OR LOWER RH VALUES FOR A PERIOD LONGER THAN A FEW HOURS...IT MAY BE NECESSARY TO ISSUE A FIRE WEATHER WATCH FOR THIS AREA. AS IT STANDS NOW NO WATCH. BY SUNDAY...FLOW ALOFT TRANSITIONS FROM WEST-NORTHWESTERLY TO SOUTHWESTERLY WITH THE PASSAGE OF THE 500MB RIDGE AXIS SATURDAY NIGHT. THIS OPENS THE DOOR TO AN INFLUX OF HIGH LEVEL MOISTURE LEADING TO A GRADUAL INCREASE IN HIGH LEVEL CLOUD COVER THROUGH THE DAY. IN ADDITION...FLOW ALOFT IS FORECAST TO STRENGTHEN THROUGH THE DAY WITH 45-60KT 700-500MB WINDS BY AFTERNOON. ON THE PLAINS...PRESSURE FALLS AROUND A SFC LOW FORMING IN THE NEBRASKA PANHANDLE WILL FURTHER ENHANCE TO SOUTH-SOUTHWEST WINDS ALREADY ON THE PLAINS. BY AFTERNOON COULD SEE GUSTS IN THE 30-40KT RANGE ALONG THE PALMER DIVIDE OUT TO THE KANSAS LINE. MAX TEMPERATURES IN THE MID 60S TO LOWER 70S...RH VALUES POSSIBLY IN THE 8 TO 15 PCT RANGE AND THE GUSTY WINDS MENTIONED ABOVE WILL FURTHER ENHANCE THE WILDLAND FIRE DANGER IN THIS AREA. NO FIREWEATHER WATCH YET...HOWEVER ONE MAY BE ISSUED WITHIN THE NEXT 24 HOURS FOR SUNDAY AFTERNOON AND EVENING. THAT SAID...WILL INTRODUCE AREAS OF BLOWING DUST TO THE SUNDAY FORECAST FOR THE SOUTHEAST CORNER OF THE FORECAST AREA. AS NOTED ABOVE...IT APPEARS SUNDAY WILL BE THE WARMER OF THE TWO WEEKEND DAYS BUT MAY NOT SEE AS MUCH SUNSHINE...ESPLY IN THE MTNS AND ACROSS THE NORTHEAST CORNER OF THE STATE NEAR THE DEVELOPING SFC LOW. BY AFTERNOON COULD SEE SCATTERED INSTABILITY SHOWERS FORMING IN THE HIGH COUNTRY AND BY EVENING ACROSS THE FAR NORTHEAST CORNER OF THE STATE. CAN/T RULE OUT A FEW T-STORMS AS WELL. ON MONDAY...THE UPPER RIDGE SHIFTS EAST ALLOWING THE NEXT IN A SERIES OF LOW AMPLITUDE SHORTWAVE TROUGHS TO PASS OVER THE STATE. MODELS ALSO SHOW A COLD FRONT EXTENDING FROM THE SFC LOW NEAR THE NORTHEAST TIP OF COLORADO PUSHING SOUTH ACROSS NORTHEASTERLY COLORADO DURING THE EARLY MORNING HOURS. COOLING ALOFT WILL COMBINE WITH THE INFLUX OF COOLER SFC AIR FROM WYOMING TO LOWER TEMPERATURES TO NEAR OR SLIGHTLY BELOW AVERAGE ON MONDAY. THE TROUGH QUICKLY MOVES OUT BY AFTERNOON ACCORDING TO MODELS AND WITH DRYING AND SUBSIDENCE IN ITS WAKE SHOULD SEE LITTLE IF ANY PRECIP ON MONDAY. INSTEAD NORTHWEST WINDS OF 30-40KTS ON THE PLAINS AND FOOTHILLS DURING THE MORNING HOURS. FOR THE REST OF THE WEEK...A WEAK SHORTWAVE RIDGE QUICKLY PASSES BY MONDAY NIGHT...FOLLOWED BY ANOTHER SOMEWHAT STRONGER SHORTWAVE TROUGH. MODELS SHOW THIS TROUGH DEEPENING OVER THE GREAT BASIN ON TUESDAY AND MIGRATING OVER COLORADO BY WEDNESDAY. ANOTHER COLD FRONT IS FORECAST TO SLIDE SOUTH ACROSS THE AREA AS THE TROUGH PASSES. SHOULD SEE PRECIP CHANCES INCREASING FIRST IN THE HIGH COUNTRY ON TUESDAY AND SPREADING TO NEARLY ALL ALL OF THE FORECAST AREA BY WEDNESDAY. COULD SEE HIGHS ON WEDNESDAY SEVERAL DEGS BELOW AVERAGE FOR THE DATE. COULD SEE THIS TROUGH HANG AROUND UNTIL THURSDAY MORNING IF THE MODELS ARE CORRECT. AFTER THAT...DRIER AND WARMER CONDITIONS RETURN WITH A STRONG UPPER RIDGE BUILDING IN FROM THE GREAT BASIN. AVIATION...SNOW HAS ENDED AT TERMINALS AS VFR CONDITIONS HAVE RETURNED. MID LEVEL CLOUD DECK WILL DIMINISH BY DAYBREAK. EXPECT INCREASING WEST TO NORTHWEST WINDS 15Z-19Z AND COULD SEE SOME GUSTS UP AROUND 30KT THIS AFTERNOON WITH GOOD LOW LEVEL MIXING. WINDS WILL DECREASE THIS EVENING WITH A RETURN TO DRAINAGE FLOW FROM THE SOUTH AND SOUTHWEST. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....BAKER AVIATION...D-L
AREA FORECAST DISCUSSION
NWS TAUNTON MA
440 PM EDT FRI MAR 28 2014 .SYNOPSIS... DRY WEATHER BRIEFLY RETURNS LATER TONIGHT INTO SATURDAY MORNING. A COASTAL STORM DEVELOPS SOUTH OF NEW ENGLAND SATURDAY...BRINGING A CHILLY...WINDSWEPT...SOAKING RAIN TO OUR REGION SATURDAY NIGHT INTO SUNDAY. DRY WEATHER RETURNS AROUND TUESDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 430 PM UPDATE...WINDS HAVE DIMINISHED A BIT ACROSS PORTIONS OF SOUTHEAST MA. SOUTHWEST WINDS ARE FUNNELING UP BUZZARDS BAY AND TAPPING INTO THE HIGHER WINDS ABOUT 3000 FEET AGL. EXPECTING MIXING TO DIMINISH THIS EVENING...WHICH SHOULD DROP WIND GUSTS BELOW ADVISORY CRITERION. WILL LEAVE THE WIND ADVISORY UP FOR THE NEXT COUPLE OF HOURS. LIGHT RAINFALL SPREADING EAST. 28/18Z HRRR IS THE MOST AGGRESSIVE GENERATING MEASURABLE RAINFALL. RADAR TRENDS THOUGH INDICATE A DRYING ACROSS MOST OF RI AND SOUTHEAST MA AS IT MOVES EAST. THINKING PRIMARILY SPRINKLES FOR THOSE AREAS...BUT WILL NOT RULE OUT THE POSSIBILITY OF A FEW LOCATIONS GETTING MEASURABLE RAINFALL. TEMPERATURES CONTINUE TO RISE ALONG THE IMMEDIATE EAST COAST... THANKS TO THE PERSISTENT SOUTHWEST WINDS. NOW THAT THE CLOUDS HAVE ARRIVED...WE SHOULD START THE SLOW FALL THROUGH THIS EVENING. EXPECTING THE RAINFALL TO MOVE OFFSHORE BY MID EVENING...ALTHOUGH A COLD FRONT WILL TAKE A LITTLE LONGER TO DO SO. ONCE THIS FRONT MOVES OFFSHORE...EXPECTING AT LEAST PARTIAL CLEARING TO DEVELOP FROM NORTH TO SOUTH. IT WILL BE TOUGH FOR TEMPERATURES TO DROP MUCH TONIGHT...WITH A DECENT SOUTHERLY WIND AND CLOUDS PERSISTING THROUGH THE EVENING. THINKING IT WILL BE A CASE OF TEMPERATURES SLOWLY FALLING THIS EVENING...THEN FALLING MUCH MORE QUICKLY AFTER MIDNIGHT WHERE THE CLOUDS BREAK UP. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... DRY TO START ALONG WITH SOME PARTIAL SUNSHINE...ESPECIALLY ACROSS NORTHERN MA INTO SOUTHWEST NH. A LOW PRESSURE DEVELOPS ALONG THIS FRONT IN THE CENTRAL APPALACHIANS BY SATURDAY EVENING. HIGH PRESSURE OVER QUEBEC...SHOULD KEEP THIS FRONT TO OUR SOUTH THROUGH THE DAY. HOWEVER...THERE WILL BE PLENTY OF WARM CONVEYOR BELT PROCESSES TO INCREASE CLOUDS AND RAINFALL CHANCES THROUGH THE DAY. TEMPERATURES SHOULD BE SIMILAR TO FRIDAY...MAINLY DUE TO THE HIGHER STARTING POINT SATURDAY MORNING. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... HIGHLIGHTS... * POTENT STORM SYSTEM WITH A GAMUT OF HEADLINES POSSIBLE SATURDAY NIGHT INTO SUNDAY. * DRY WEATHER FOR THE MIDDLE OF THE WEEK * MORE ACTIVE PATTERN FOR THE END OF THE WEEK MODELS AND CONFIDENCE... MODERATE CONFIDENCE IN THE OVERALL FORECAST ESPECIALLY BECAUSE OF THE SIGNIFICANT SPREAD LATE NEXT WEEK. HOWEVER DO HAVE HIGH CONFIDENCE THAT HEAVY PRECIP WILL OCCUR LATE SAT INTO SUN ACROSS A GOOD PORTION OF THE REGION. MODERATE CONFIDENCE THAT SOME OF THAT PRECIP WILL BE IN A WINTRY MIX LATE SUNDAY INTO MONDAY. LOWER CONFIDENCE ON THE FORECAST FOR NEXT WEEK HOWEVER IT APPEARS THAT THERE MAY BE A DRY DAY OR TWO THANKS TO HIGH PRESSURE. 12Z GUIDANCE IS IN GOOD AGREEMENT WITHIN THE MEDIUM RANGE...HOWEVER IN THE LONG RANGE IT APPEARS TO HAVE SIGNIFICANT DIFFERENCES. A STALLED LOW WILL MOVE OVER THE REGION LATE SATURDAY AND STALL UNTIL MONDAY. UPPER LEVEL RIDGE WILL DEVELOP BY TUESDAY/WEDNESDAY BEFORE ANOTHER STRONG UPPER LEVEL LOW MOVES INTO THE REGION BY THE END OF THE WEEK. OVERALL TRENDED THE FORECAST OUTSIDE OF THE SYSTEM TOWARD THE ENSEMBLES. DETAILS ON THE STALLED LOW ARE BELOW. DETAILS... SATURDAY NIGHT INTO MONDAY... * MODELS/OVERVIEW...A FRONT WILL STALL OVER THE REGION COMBINED WITH THE APPROACHING UPPER LEVEL LOW...WILL BE THE FOCUS FOR THE WEATHER OVER THE WEEKEND. DETAILS ON THE MODEL GUIDANCE...FIRST THREW OUT THE NAM AS IT IS TO PROGRESSIVE AND THEREFORE BRINGING A COLD BIAS INTO THE REGION THE LATE SUNDAY INTO MONDAY TIME PERIOD. TRENDED TOWARDS THE EC/GFS AS THE MORE AMPLIFIED TREND SEEM REASONABLE. THE OVERALL AXIS OF HEAVIER PRECIP ON BOTH OF THE GFS AND EC HAS SHIFTED SLIGHTLY EASTWARD COMPARED TO 00Z GUIDANCE. THIS GOES ALONG WITH THE THINKING OF THE ENSEMBLES. OVERALL TRENDED THE FORECAST TO A 2:1 GFS TO EC COMBO WITH THE QPF GEARED MORE TOWARDS THE RFC. * DETAILS...STACKED COASTAL LOW WILL MOVE CLOSER TO THE REGION SATURDAY NIGHT INTO SUNDAY RESULTING IN THE DEVELOPMENT OF A STRONG SOUTHERLY LLJ BEHIND THE WARM FRONT. EXPECT HEAVY RAIN TO START AFTER 06Z SAT NIGHT AS A BOUNDARY LAYER CONVERGENCE REGION SETS UP ACROSS THE 95 CORRIDOR WITH EXCELLENT MOISTURE TRANSPORT FEEDING INTO IT. THE LLJ WILL STRENGTHEN THROUGH THE MORNING HOURS ON SUNDAY RESULTING IN SHOWALTER VALUES REACHING ABOVE 0C AND K INDEX VALUES ABOVE 30C. THIS COULD DEVELOP SOME ISOLATED THUNDER DURING THE DAY ON SUNDAY WHICH WILL BE CONFIDED TO THE LOCATIONS SOUTH OF THE MASS PIKE INCLUDING THE WATERS. THIS COINCIDES WITH THE NOSE OF THE LLJ. INTERESTING NOTE IS THAT THE BOUNDARY LAYER MOISTURE CONFERENCE JUST SITS OVER THE 95 CORRIDOR THROUGH 00Z MONDAY. THIS GIVES FORECASTER CONFIDENCE THAT THE AXIS OF HEAVIER PRECIP WILL SIT JUST ALONG OR NW OF THIS CONVERGENCE AREA. A DRY SLOW WILL TRY TO MAKE ITS WAY OVER THE CAPE AND THE ISLANDS BY LATE SUNDAY AS THE SYSTEM DEEPENS AND BEGINS TO DEVELOP A TROWAL FEATURE ON THE BACKSIDE. AS THE LOW PRESSURE SYSTEM MOVES EASTWARD...THIS TROWAL FEATURE WILL BECOME MORE PRONOUNCE AND WITH STRONG NORTHERLY WINDS ON THE BACKSIDE OF THE SYSTEM EXPECT SOME WINTRY PRECIP. RIGHT NOW IT APPEARS THAT THE MAIN P-TYPE WILL BE IN THE FORM OF A COLD RAIN WITH SOME SLEET OF FREEZING RAIN MIXED IN AS TEMPERATURES AT THE SURFACE WILL DROP FASTER THAN ALOFT. THIS MIXING WILL LAST INTO MONDAY BEFORE THE SYSTEM PULLS OUT OF THE REGION ENTIRELY BY MONDAY AFTERNOON. * IMPACTS...HAVE INCREASING CONFIDENCE THAT HEAVY PRECIP WILL OCCUR AND A MODERATE CONFIDENCE THAT OVER 2 INCHES WILL FALL ACROSS SOUTHERN NEW ENGLAND BETWEEN SAT EVENING INTO SUNDAY NIGHT. THEREFORE WE HAVE ISSUED A FLOOD WATCH FOR AREAS THAT MAY SEE NOT ONLY A GOOD AMOUNT OF QPF BUT ALSO THE POTENTIAL FOR RIVER RISE. THE 12Z GEFS HAVE A 60-70 PERCENT PROBABILITY OF EXCEEDING 2 INCHES AND WITHIN A 24 HOUR PERIOD BOTH THE GFS AND EC SHOW THE POSSIBILITY OF OVER 2 INCHES. TRENDED THE FORECAST TOWARDS A COMBINATION OF THE GFS/EC AND RFC FOR QPF. AT MOST A FEW OF THE MAIN STEM RIVERS MAY RISE INTO ACTION AND MAY TOUCH FLOOD STAGE DEPENDING ON WHERE THE HEAVIEST QPF FALLS AS WELL AS SNOW MELT AND ICE JAM POTENTIAL. IF WE ANTICIPATE 3 OR MORE THEN WE MAY HAVE TO START LOOKING AT RIVER FLOODING POTENTIAL...MORE DETAILS BELOW. AS MENTIONED ABOVE APPEARS THAT ELEVATED THUNDER WILL OCCUR ON SUNDAY...DO NOT ANTICIPATE ANY STRONG OR SEVERE WEATHER AT THIS TIME. BECAUSE OF THE STRONG LLJ WE COLD SEE WIND ADV HEADLINES ACROSS THE CAPE AND THE ISLANDS BUT LEFT THE POTENTIAL OUT FOR NOW AS CONFIDENCE IS LOWER. ON THE BACKSIDE OF THIS SYSTEM...TEMPERATURES COULD DROP BELOW 32 AND WITH TEMPS ALOFT BEING 2-3C ABOVE 0 THEN THERE IS THE POTENTIAL FOR ICE ESP ACROSS THE NW PORTION OF THE FORECAST REGION. HOWEVER IF DYNAMIC COOLING OCCURS AND THE SYSTEM CAN DRAW THAT COLD AIR ALOFT DOWN TO THE LOW LEVELS THEN THERE MAY BE SLEET/SNOW ON THE BACKSIDE. THIS ICE/SLEET POTENTIAL LINES UP WITH WPC GRAPHICS. THERE IS ALSO THE POTENTIAL FOR MINOR COASTAL FLOODING ALONG BOTH THE SOUTH COAST AND EAST COAST SHORELINES FOR MULTIPLE HIGH TIDE CYCLES...MORE DETAILS BELOW. TUESDAY AND WEDNESDAY.... WEAK RIDGING ALOFT WILL SET-UP ACROSS THE AREA ON TUESDAY AND WEDNESDAY YIELDING TO HIGH PRESSURE AND HOPEFULLY DRY WEATHER. TEMPERATURES WILL BE CLOSER TO SEASONABLE THANKS TO A THERMAL RIDGE. THURSDAY AND BEYOND... SEVERAL RIPPLES MOVING THROUGH THE LONG WAVE RIDGE WILL YIELD TO CLOUDS AND SHOWERY WEATHER. TEMPERATURES WILL BE CLOSE TO SEASONABLE. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. OVERALL FORECAST CONFIDENCE IS MODERATE THROUGH SATURDAY. HAVE HIGH CONFIDENCE IN TRENDS...BUT ONLY MODERATE CONFIDENCE IN TIMING. THROUGH 00Z...MAINLY VFR OUTSIDE OF SHOWERS...WITH MVFR IN ANY SHOWERS. LOCAL IFR DEVELOPING ACROSS THE HIGHER TERRAIN OF CENTRAL MA AND SOUTHWEST NH. TONIGHT...FRONT SLIPS SOUTH OF NEW ENGLAND. MVFR/IFR IMPROVES TO VFR...TAKING LONGEST ALONG THE SOUTH COAST. ANY LINGERING RAIN SHOWERS ON THE SOUTH COAST MOVE OFFSHORE LATE THIS EVENING. SATURDAY...VFR AND DRY TO START...THEN LOWERING TO MVFR AS RAIN MOVES NORTH LATER IN THE AFTERNOON. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SW WINDS MAY BRIEFLY GUST UP TO 35 KT LATE THIS AFTERNOON. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... SATURDAY NIGHT THROUGH MONDAY...MODERATE CONFIDENCE. AREAS OF MVFR CIGS/VSBYS IN HEAVY RAIN/FOG. A WINTRY MIX IS POSSIBLE LATE SUNDAY NIGHT INTO MONDAY AS PRECIP COMES TO AN END. TUESDAY INTO WEDNESDAY...MODERATE TO HIGH CONFIDENCE. IMPROVING CONDITIONS AS RAIN MOVES OUT OF THE REGION...VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. MODERATE TO HIGH FORECAST CONFIDENCE THRU SAT NIGHT. TONIGHT... A COLD FRONT MOVES OFFSHORE WITH WINDS DIMINISHING AND SHIFTING FROM SW TO WNW BY SATURDAY MORNING. WILL NEED TO REPLACE GALE WARNINGS WITH SMALL CRAFT ADVISORIES AS WINDS DIMINISH THIS EVENING. SATURDAY... WARM FRONT LIFTS NORTH WITH INCREASING SOUTH WINDS ACROSS THE SOUTHERN OUTER COASTAL WATERS. RAIN ALSO OVERSPREADS SOUTHERN WATERS. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... SATURDAY NIGHT THROUGH MONDAY...LOW TO MODERATE CONFIDENCE. GALE WARNINGS WILL LIKELY BE NEEDED FOR SOME OF THE COASTAL WATERS AS LOW PRESSURE MOVES OVER THE WATERS. SEAS INCREASE TO 10 TO 15 FEET ON THE OUTER WATERS. VISIBILITIES WILL LIKELY BE LIMITED AT TIMES IN HEAVY RAIN AND FOG. TUESDAY INTO WEDNESDAY...WINDS AND SEAS DIMINISH AS WEAK HIGH PRESSURE BEGINS TO BUILD OVER THE WATERS. && .HYDROLOGY... MARCH PRECIPITATION HAS BEEN MOSTLY SPARSE ACROSS SOUTHERN NEW ENGLAND...BUT WE MAY MAKE UP FOR THIS IN ABUNDANCE DURING THIS WEEKEND. RIVERS AND STREAMS ARE RUNNING BELOW NORMAL FOR THIS TIME OF YEAR...WHICH PROVIDES US A BUFFER. HOWEVER...THE POTENTIAL FOR 2 TO 4 INCHES OF RAINFALL WITH VEGETATION STILL DORMANT ...PLUS SNOWMELT IN THE FAR INTERIOR...IS SUFFICIENT TO BRING THE CONCERN OF MINOR FLOODING ON AREA RIVERS AND STREAMS. THE MAIN AREA OF CONCERN AT THIS TIME IS INTERIOR SOUTHERN NEW ENGLAND...AND THIS IS WHERE FLOOD WATCHES ARE GOING INTO EFFECT. POOR DRAINAGE AREAS ...SMALL STREAMS...AND SOME LARGER TRIBUTARY RIVERS WILL BE AT RISK. IN ADDITION...THE MORE VULNERABLE FORECAST LOCATIONS ON THE LOWER MAINSTEM CONNECTICUT RIVER WILL NEED TO BE MONITORED OVER THE COURSE OF THIS EVENT. FOR RIVER FORECAST POINTS THAT ARE BEING MONITORED...GO TO HTTP://WATER.WEATHER.GOV/AHPS2/FORECASTS.PHP?WFO=BOX . LOCATIONS OF MAIN CONCERN ARE THOSE FORECAST TO GO TO ACTION STAGE OR HIGHER. NOTE THAT THE FORECASTS GO OUT 72 HOURS...AND IN SOME INSTANCES THE GAUGES ARE FORECAST TO BE CLIMBING THROUGH THE END OF THE FORECAST PERIOD. AS MENTIONED...AT THIS TIME MINOR FLOODING IS EXPECTED TO BE THE THREAT ON THE LARGER RIVERS. WHILE REPORTS FROM OFFICIALS IN THE INTERIOR INDICATE RIVER ICE HAS DECREASED IN COVERAGE AND THICKNESS OVER THE PAST TWO WEEKS...THERE ARE STILL INDICATIONS THAT SOME RIVERS AND STREAMS IN SOUTHWEST NEW HAMPSHIRE AND FAR NORTHWEST MASSACHUSETTS HAVE SUFFICIENT ICE TO WARRANT A LOW RISK OF ICE JAMS AND ICE JAM RELATED FLOODING. WORDING IN THE FLOOD WATCH IS BEING MENTIONED ACCORDINGLY. && .TIDES/COASTAL FLOODING... THE WEEKEND INTO EARLY NEXT WEEK SYSTEM POSES SOME RISK OF COASTAL FLOODING AND BEACH EROSION SINCE THE ASTRONOMICAL HIGH TIDES ARE RELATIVELY HIGH. THE SITUATION IS A BIT COMPLICATED WITH BOTH SOUTH AND EAST COASTS AS WELL AS MULTIPLE HIGH TIDE CYCLES AT RISK. AT THIS TIME THE IMPACT LOOKS TO BE MOSTLY MINOR BUT JUST A FAIRLY MODEST STRENGTHENING OF THE COASTAL LOW AND ASSOCIATED LOW LEVEL JET COULD RESULT IN A MODERATE IMPACT AT A FEW LOCATIONS. SINCE THE EVENT IS STILL 2 TO 3 DAYS OUT...THE ONLY HEADLINE ISSUED NOW IS A COASTAL FLOOD ADVISORY FOR PORTIONS OF THE RI AND MA SOUTH COAST FOR THE SUN MORNING HIGH TIDE. ADDITIONAL HEADLINES MAY BE NEEDED DURING THE COURSE OF THE WEEKEND. SOUTH COAST...HAVE AT LEAST MODERATE CONFIDENCE OF MINOR COASTAL FLOODING DURING THE SUNDAY MORNING HIGH TIDE IN PORTIONS OF NARRAGANSETT BAY AND OTHER PORTIONS OF THE RI/MA COAST INCLUDING WESTPORT. A VIGOROUS LOW LEVEL JET OF 50 TO 60 KT ON BOTH THE GFS AND ECMWF IS EXPECTED TO INDUCE A 1 TO 1.8 FOOT SURGE...HIGHEST UPPER PART OF NARRAGANSETT BAY...FOR THE SUN MORNING HIGH TIDE. WAVES APPROACHING 10 FT JUST OFFSHORE MAY BE SUFFICIENT FOR SOME SPLASHOVER AT THE TIME OF THE HIGH TIDE ALONG SOME SOUTH COAST EXPOSED BEACHES SUCH AS THE NEWPORT AND WESTPORT SOUTH COAST BEACHES AS WELL AS THE WEST ISLAND CAUSEWAY IN FAIRHAVEN. LESS CONFIDENT ON ANY IMPACTS FOR THE SUN EVENING HIGH TIDE. ANTICIPATE THE S OR SE FLOW TO HAVE DIMINISHED OR ENDED BUT WATER MAY BE SLOW TO EVACUATE FROM A FEW LOCATIONS INCLUDING NARRAGANSETT BAY WITH PRES FALLS BEING A POSSIBLE SECONDARY FACTOR. EAST COAST OF MA...A N TO NNE FLOW BECOMES ESTABLISHED LATE SUN THROUGH MON AND THEN BECOMING MORE NNW BY MON NIGHT. A LOW LEVEL JET OF 40 TO 50 KT IMPACTS THE COASTLINE N OF BOS FOR THE SUN NIGHT HIGH TIDE AND MOST OF THE MA E COAST FOR THE MON MIDDAY HIGH TIDE. THERE IS SOME SUGGESTION...ESPECIALLY FROM THE ECMWF MODEL...THAT THE LOW LEVEL JET MAY PERSIST TO IMPACT THE HIGH TIDE AROUND 1 AM TUE FOR NANTUCKET HARBOR AND THE N SIDE OF CAPE COD. ALTHOUGH AT THIS TIME THE IMPACTS LOOK TO BE MOSTLY MINOR...MULTIPLE HIGH TIDE CYCLES ARE LIKELY TO BE INVOLVED AND JUST A MODESTLY STRONGER SYSTEM AND ASSOCIATED NNE WINDS COULD RESULT IN POCKETS OF MODERATE IMPACTS. GIVEN THAT MULTIPLE TIDE CYCLES WILL LIKELY BE AFFECTED...AT LEAST SOME BEACH EROSION IS LIKELY FROM SALISBURY TO CAPE ANN INCLUDING PLUM ISLAND...THE PLYMOUTH COUNTY COAST...N AND OCEAN SIDES OF CAPE COD AND THE E SIDE OF NANTUCKET BEFORE THIS EVENT IS OVER. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR CTZ002>004. MA...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ018>023. COASTAL FLOOD ADVISORY FROM 6 AM TO 10 AM EDT SUNDAY FOR MAZ020. FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR MAZ002>006-008>012-026. NH...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY AFTERNOON FOR NHZ011-012-015. RI...COASTAL FLOOD ADVISORY FROM 6 AM TO 10 AM EDT SUNDAY FOR RIZ002-004-005-007. FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR RIZ001. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR ANZ231>234. GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ230-251. SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ236. SMALL CRAFT ADVISORY UNTIL NOON EDT SATURDAY FOR ANZ235-237- 254. SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ250. SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ255-256. && $$ SYNOPSIS...BELK/DUNTEN NEAR TERM...BELK SHORT TERM...BELK LONG TERM...DUNTEN AVIATION...BELK/DUNTEN MARINE...BELK/DUNTEN HYDROLOGY...NMB TIDES/COASTAL FLOODING...THOMPSON
AREA FORECAST DISCUSSION
NWS ALBANY NY
422 PM EDT FRI MAR 28 2014 .SYNOPSIS... A FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION TONIGHT WITH IMPROVING CONDITIONS DEVELOPING FROM WEST TO EAST. ANOTHER STORM SYSTEM APPROACHES AND WILL BRING MODERATE TO HEAVY AMOUNTS OF PRECIPITATION FOR MOST OF THIS WEEKEND. THE POTENTIAL FOR FLOODING AND ICE JAMS INCREASES ALONG WITH WINTER WEATHER CONCERNS ACROSS THE ADIRONDACKS. OUR WEATHER IS EXPECTED TO IMPROVE INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... TEMPERATURES ACROSS CENTRAL AND WESTERN NEW YORK HAVE RISEN WELL INTO THE 50S AS THIS REGION HAS BEEN PRECIPITATION FREE THE PAST SEVERAL HOURS /EVEN SOME BREAKS IN THE CLOUD COVER SEEN IN THE 1KM VISIBLE IMAGERY/. WE STILL HAVE A FEW MORE HOURS OF DAYLIGHT AS WE STILL COULD ACHIEVE OUR MILDER TEMPERATURES AND WE WILL RETAIN THE HOURLY GRIDS WITH SLIGHT MODIFICATIONS PER OBSERVATIONS. COLD FRONT WAS JUST APPROACHING EXTREME WESTERN NY AS SHOWERS WERE JUST DEVELOPING AT THE TIME OF WRITING THIS DISCUSSION. PER THE LATEST HRRR REFLECTIVITY FORECASTS...SEEMS THESE SHOWERS WILL MOVE ACROSS THE REGION THROUGH EARLY THIS EVENING. THE THERMAL CONTRAST WITH FROPA IS NOT THAT NOTICEABLE AS LATEST MOS GUIDANCE CAPTURES THIS IDEA AS WE WILL LEAN TOWARD A SLIGHTLY WARMER OVERNIGHT LOWS. RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION OVERNIGHT WITH GRADUALLY IMPROVING SKY CONDITIONS FROM WEST TO EAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... ...FLOOD WATCH IN EFFECT OUTSIDE OF THE ADIRONDACKS... ...WINTER STORM WATCH IN EFFECT FOR THE ADIRONDACKS... H2O VAPOR LOOP REVEALS THE KEY PLAYERS WITH A COUPLE OF NOTABLE UPPER LEVEL WAVES ACROSS THE PLAINS. MODEL DIAGNOSIS HAS COME INTO A RATHER GOOD AGREEMENT OF PHASING EVOLVING ACROSS THE OHIO/TENNESSEE VALLEY TRANSITIONING INTO AN CLOSED UPPER LOW OVER THE MID ATLANTIC REGION. THERMAL PROFILES CONTINUE TO WARM IN THE GLOBAL MODELS AS THE NAM REMAINS TOO COLD. COMBINATION OF MODERATE TO HEAVY QPF...THERMAL PROFILES LINING UP ACROSS THE ADIRONDACKS...WARMING THERMAL PROFILES FOR ICE BEGINNING TO MOVE ALONG THE RIVERS/STREAMS COULD RESULT IN ICE JAMS. NOW ONTO THE DETAILS... SATURDAY... MOST OF THE DAY SHOULD BE RATHER TRANQUIL AS WE BEGIN THE DAY RATHER DRY WITH PARTIAL SUNSHINE IN THE MORNING. CLOUDS WILL EVENTUALLY INCREASE FROM SOUTH TO NORTH AS TEMPERATURES ACROSS MOST OF THE REGION MODERATING INTO THE 40S WITH COOLER 30S ACROSS THE ADIRONDACK REGION. THESE TEMPS WILL BE KEY TO THE PRECIP TYPE EXPECTED SATURDAY NIGHT. SATURDAY NIGHT... CROSS SECTIONS AND BUFR PROFILES WITH RESPECT TO TEMPERATURES REVEAL A RATHER SHARP CONTRAST ACROSS THE ADIRONDACK REGION. THE LOW LEVEL AGEOSTROPHIC FLOW INCREASES FROM THE NORTH WHICH COULD KEEP THE NEAR SURFACE TEMPERATURES NEAR OR JUST BELOW FREEZING. THIS COULD RESULT IN A PERIOD OF SLEET OR FREEZING RAIN ACCUMULATION ACROSS THIS REGION AND PER COLLABORATION FROM SURROUNDING WFOS AND WPC WWD...WE WILL HOIST A WINTER STORM WATCH FOR THIS REGION. OUTSIDE OF THIS REGION...A MODERATE TO HEAVY RAINFALL EVENT SEEMS TO BE UNFOLDING AS PWAT ANOMALIES OF 1-3 STANDARD DEVIATIONS ABOVE NORMAL...ASSOCIATED LOW LEVEL SOUTHERLY WIND ANOMALIES AND IMPRESSIVE 2D FGEN OVERHEAD TO BRING ABOUT A PERIOD OF VERY WET WEATHER. PLEASE REFER TO THE HYDROLOGY DISCUSSION BELOW FOR FURTHER DETAILS. SUNDAY... MID LEVEL DRY SLOT APPROACHES AND SHOULD DIMINISH THE PRECIP INTENSITY ACROSS THE AREA. DEFORMATION AXIS PER THE GLOBAL MODELS APPEARS TO LINE UP JUST WEST OF OUR SERVICE AREA /NEAR I81/ SO THE PRECIP THROUGH THE DAY IS EXPECTED TO REMAIN LIGHT. WE WILL LOWER POPS ACCORDINGLY AS COLDER AIR ATTEMPTS TO SEEP INTO THE DACKS WHERE ADDITIONAL LIGHT ACCUMULATIONS ARE POSSIBLE. SUNDAY NIGHT... THE AFOREMENTIONED DEFORMATION AXIS IS EXPECTED TO MIGRATE ACROSS THE REGION...MEANWHILE...LOW LEVEL COLD ADVECTION IS FORECAST TO INCREASE. THIS WOULD SUGGEST ANOTHER PERIOD OF WET WEATHER TRANSITIONING TOWARD WINTRY TYPE PRECIPITATION ISSUES DEVELOPING ACROSS THE ENTIRE REGION. THE LATEST ECMWF IS SUGGESTING QUITE A STRONG SIGNAL THAT LATER FORECAST SHIFTS CAN FINE TUNE. && .LONG TERM /MONDAY THROUGH FRIDAY/... THE LONG TERM STARTS WITH THE CUTOFF LOW STILL BRINGING RESIDUAL CLOUDS AND SHOWERS...MAINLY FROM THE HUDSON VALLEY EASTWARD ON MONDAY. THIS LOW IS FORECAST TO SLOWLY PULL AWAY FURTHER EAST THAT DAY...WITH CONDITIONS SLOWLY IMPROVING. HOWEVER...SINCE ANY SUNSHINE WOULD GENERALLY BE LIMITED TO LATER IN THE DAY...WE HAVE TRIMMED HIGH TEMPERATURES BACK FOR THAT DAY...GENERALLY LOOKING AT 50-55 ALBANY SOUTHWARD...40S FURTHER NORTH WEST AND EVEN EAST OF ALBANY (WHERE CLOUDS WILL LINGER THE LONGEST). RIDGE OF HIGH PRESSURE FINALLY BUILDS IN MONDAY NIGHT INTO TUESDAY. THE QUESTION IS WHETHER OR NOT CLOUDS COULD REFORM UNDERNEATH AN INVERSION MONDAY NIGHT. FOR NOW...WE PLAYED IT CAUTIOUSLY OPTIMISTIC AND WENT WITH PARTLY CLOUDY MONDAY NIGHT. IF WE WERE TO CLEAR...THERE COULD BE SOME FOG ISSUES TO DEAL WITH ALONG WITH LOWER TEMPERATURES THAN WE ARE CURRENTLY FORECASTING. FOR NOW...WE LEFT FOG OUT OF THE FORECAST SINCE THIS IS STILL SEVERAL DAYS OUT. WITH PARTIAL CLEARING....LOOK FOR LOWS TO SLIP BACK INTO THE LOWER TO MID 30S FROM THE CAPITAL REGION SOUTHWARD...20S FURTHER NORTH AND ACROSS MUCH OF ELEVATED TERRAIN. TUESDAY...FINALLY...LOOKS LIKE THE DAY MOST OF US HAVE BEEN WAITING FOR. IT WILL MARK THE BEGINNING OF APRIL AND WE WILL LEAVE THE CHILL OF MARCH BEHIND. EVEN IF WE DO START THE DAY CLOUDY...THEY SHOULD BREAK UP FAIRLY QUICKLY. H850 TEMPERATURES LOOK TO WARM BACK UP TO ABOUT +5C. WITH A STRONG APRIL SUNSHINE AND FAIRLY GOOD MIXING...TEMPERATURES LOOK TO CLIMB TO THE UPPER 40S TO LOWER 50S ACROSS THE ADIRONDACKS AND SOUTHERN GREENS...MID TO UPPER 50S ACROSS THE REMAINDER OF THE REGION...WITH PERHAPS A FEW SPOTS IN THE MID HUDSON VALLEY...TOUCHING 60 DEGREES. THE WIND SHOULD BE LIGHT SO IT WILL FEEL PLEASANT OUTDOORS TO MOST FOLKS AND FINALLY FEEL LIKE SPRING. A WEAK SYSTEM FROM SOUTHERN CANADA LOOK TO BRING A FEW RAIN OR SNOW SHOWERS...MAINLY NORTH OF THE CAPITAL REGION TUESDAY NIGHT INTO WEDNESDAY. THIS SYSTEM LOOKS MOISTURE STARVED AT THIS POINT...SO ANY PRECIPITATION LOOKS LIGHT. THIS STORM WILL DRAG A COLD FRONT THROUGH THE MOST OF THE REGION BY WEDNESDAY...COOLING TEMPERATURES DOWN A LITTLE. A WEST TO NORTHWEST BREEZE WILL HOLD TEMPERATURES IN THE LOWER 50S LOCALLY IN THE CAPITAL REGION ON WEDNESDAY...MAINLY 40S NORTH. TO THE LEE OF THE CATSKILLS...INCLUDING THE MID HUDSON VALLEY AND LITCHFIELD COUNTY...THANKS TO A DOWNSLOPING WIND AND ABUNDANT SUNSHINE...TEMPERATURES WILL ONCE AGAIN BOUNCE INTO THE MID OR UPPER 50S. THE REST OF THE REGION WILL RANGE FROM MOSTLY CLOUDY (MOUNTAINS) TO PARTLY SUNNY(MOHAWK VALLEY AND GREATER CAPITAL REGION). HIGH PRESSURE WILL ATTEMPT TO WEDGE INTO THE REGION FROM SOUTH CENTRAL CANADA LATER WEDNESDAY INTO THURSDAY. AT THE SAME TIME HOWEVER...ANOTHER CUTOFF LOW PRESSURE IS FORECAST TO GATHER STRENGTH IN THE NATION/S MIDSECTION. THE QUESTION IS WHETHER OR NOT HIGH PRESSURE WILL TAKE CONTROL AND KEEP THE CUTOFF TO OUR SOUTHWEST FOR THE REMAINDER OF THE WEEK. OR...WILL THE LOW PRESSURE SLOWLY WORK INTO OUR REGION? THE FORMER SOLUTION IS OFFERED BY THE 12Z EUROPEAN MODEL WHILE THE LATTER WETTER SOLUTION IS FORECASTED BY THE 12Z GFS. FOR NOW...FOLLOWED MAINLY THE WEATHER PREDICTION CENTER`S TAKE ON THINGS (WPC)...WHICH LEANED MORE WITH THE WETTER GFS. WE HAVE SLIGHT CHANCES OF POPS IN FOR THURSDAY...INCREASING THEM TO CHANCE THURSDAY NIGHT THROUGH FRIDAY. HIGH TEMPERATURES ON THURSDAY AND FRIDAY WILL BE HIGHLY DEPENDENT ON CLOUD COVER. SINCE WE ARE GOING WITH INCREASING CLOUDS ON THURSDAY...AND CLOUDY WITH BETTER CHANCES FOR SHOWERS FRIDAY...WENT WITH SEASONABLE TEMPERATURES THURSDAY (MID 40S NORTH TO MID 50S SOUTH) AND COOLER TEMPERATURES FRIDAY (LOWER 40S NORTH TO LOWER 50S SOUTH). IT MIGHT BE COLD ENOUGH THURSDAY NIGHT FOR SOME MOUNTAIN SNOWS...BUT MOST VALLEY AREAS SHOULD REMAIN ALL RAIN. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... AS A COLD FRONT APPROACHES THE REGION...AN AREA OF RAIN THIS AFTERNOON WILL TAPER OFF TO SHOWERS BY THIS EVENING. WITHIN THIS RAINFALL...FLYING CONDITIONS WILL GENERALLY BE MVFR...BUT BRIEF PERIODS OF IFR CIGS/VSBYS CANNOT BE RULED OUT FOR KGFL/KPSF/KALB THROUGH THE EARLY EVENING HOURS. HAVE ACCOUNTED FOR THIS WITH A TEMPO GROUP. SOUTHERLY SFC WINDS WILL BE AROUND 10 KTS...WITH A FEW HIGHER GUSTS FOR KALB...AS AIR IS FUNNELED UP THE HUDSON VALLEY. THE THREAT FOR RAINFALL WILL END THIS EVENING WITH THE PASSAGE OF THE COLD FRONT. FLYING CONDITIONS WILL STILL BE MVFR FOR A FEW HOURS DUE TO LINGERING LOW LEVEL MOISTURE KEEPING CIGS AROUND 1-3 KFT. BY LATER TONIGHT...A DRIER W-NW FLOW AT 5-10 KTS WILL ALLOW FOR VFR CONDITIONS TO RETURN WITH JUST SOME REMAINING SCT CLOUDS AROUND. LIGHT N-NE WINDS WILL BE IN PLACE FOR SATURDAY MORNING WITH NO PRECIPITATION. HOWEVER...MID AND HIGH LEVEL CLOUDS WILL INCREASE THROUGH THE MORNING HOURS FROM SOUTH TO NORTH AS A STORM ORGANIZES OVER THE MID ATLANTIC REGION. SOME RAIN WILL SPREAD BACK INTO THE REGION FROM SOUTH TO NORTH DURING THE AFTN HOURS...WITH MVFR CONDITIONS /MAINLY DUE TO VSBYS/ EXPECTED. OUTLOOK... SATURDAY AFTN: HIGH OPERATIONAL IMPACT. LIKELY RA. SATURDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA...SLEET. SUNDAY: HIGH OPERATIONAL IMPACT. BREEZY. DEFINITE RA. SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHRA...SHSN. MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. MONDAY NIGHT TO WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... NO FIRE WEATHER RELATED ISSUES ARE EXPECTED THROUGH AT LEAST THE NEXT SEVERAL DAYS. THE WET WEATHER OF TODAY AND THEN A STRONGER COASTAL SYSTEM EXPECTED TO BRING MODERATE TO HEAVY AMOUNTS OF PRECIPITATION TO THE REGION OVER THE WEEKEND. SOME OF THE PRECIPITATION MAY FALL AS SNOW OR A WINTRY MIX...ESPECIALLY ACROSS THE HIGHER TERRAIN. && .HYDROLOGY... THERE WILL BE AN INCREASING POTENTIAL FOR HYDROLOGIC ISSUES...INCLUDING RIVER ICE BREAK UP AND POSSIBLE FLOODING...OVER THE WEEKEND. FLOOD WATCH IS NOW IN EFFECT OUTSIDE OF THE ADIRONDACK REGION. RAINFALL AMOUNTS CLOSE TO ONE HALF OF AN INCH HAVE BEEN OBSERVED WITH SOME SLIGHT INCREASE NOTICED ON RIVER GAGES. HOWEVER...TEMPERATURES HAVE BEEN SLOW TO RISE WHICH HAS ASSISTED WITH THE RAINFALL LIKELY BEING ABSORBED INTO THE SNOWPACK AND LITTLE ICE MOVEMENT AT THIS TIME. HOWEVER...A MORE SIGNIFICANT STORM SYSTEM WILL MOVE FROM THE MID ATLANTIC COAST TOWARDS NEW ENGLAND FOR LATE SATURDAY INTO SUNDAY. THIS SYSTEM HAS THE POTENTIAL TO BRING MODERATE TO HEAVY AMOUNTS OF PRECIPITATION TO THE REGION...ESPECIALLY FOR AREAS FROM THE CAPITAL REGION SOUTH AND EAST...WITH MODEL CONSENSUS SHOWING ONE TO THREE INCHES OF RAINFALL ACROSS SOUTHEASTERN PARTS OF THE REGION. WHILE MUCH OF THIS WILL BE IN THE FORM OF RAINFALL...THERE IS THE POTENTIAL FOR THE PRECIP TO CHANGE TO A WINTRY MIX OR SNOWFALL BEFORE ENDING...MAINLY FOR NORTHERN AND HIGH TERRAIN AREAS. CURRENT NERFC RIVER FORECASTS SHOW RISING LEVELS TO NEAR OR ABOVE FLOOD STAGE. THERE IS THE POTENTIAL FOR SIGNIFICANT RISES...ESPECIALLY ACROSS THE HOUSATONIC BASIN...AND SUBSEQUENT RIVER ELEVATION FORECASTS MAY NEED TO BE INCREASED IF THE LATEST TRENDS IN MODEL GUIDANCE ARE CORRECT. ALTHOUGH QPF AMOUNTS ARE ARE NOW FORECAST TO RANGE BETWEEN 1 AND 3 INCHES...THE CHALLENGE IS ICE BREAKING UP ON LARGER MAIN STEM RIVERS AS WELL...WHICH COULD POTENTIALLY CAUSE ICE JAMS IN SOME LOCATIONS. WITH THE BULK OF THE RAINFALL EXPECTED TO OCCUR SATURDAY NIGHT IN A RELATIVELY SHORT PERIOD OF TIME...SOME MINOR URBAN...LOW LYING...AND SMALL STREAM FLOODING COULD POTENTIALLY OCCUR AS WELL. THE MOST LIKELY AREAS TO SEE ISSUES WOULD BE FROM THE MOHAWK BASIN SOUTH AND EAST. DRIER WEATHER LOOKS TO RETURN FOR MONDAY THROUGH WEDNESDAY OF NEXT WEEK...ALLOWING RIVERS AND STREAMS TO SLOWLY RECEDE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR CTZ001-013. NY...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR NYZ038>041-043-047>054-058>061-063>066-082>084. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR NYZ032-033-042. MA...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR MAZ001-025. VT...FLOOD WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR VTZ013>015. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...HWJIV AVIATION...FRUGIS FIRE WEATHER...BGM/JPV HYDROLOGY...BGM FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1014 AM EDT FRI MAR 28 2014 .SYNOPSIS... LOW PRESSURE MOVING ACROSS THE EASTERN GREAT LAKES TODAY WILL PROVIDE MILD CONDITIONS AND SCATTERED AFTERNOON RAIN SHOWERS TO SOUTHERN NEW ENGLAND. DRY WEATHER BRIEFLY RETURNS TONIGHT INTO SATURDAY MORNING BEFORE A COASTAL STORM DEVELOPS SOUTH OF NEW ENGLAND...BRINGING A CHILLY WINDSWEPT SOAKING RAIN TO THE REGION SATURDAY NIGHT INTO SUNDAY. DRY WEATHER RETURNS AROUND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE...RAINFALL STARTING TO BECOME MORE WIDESPREAD ACROSS NORTHWEST MA AND SOUTHWEST NH. TEMPERATURES ACROSS THAT REGION ARE ALL ABOVE FREEZING NOW...ENDING THE THREAT OF FREEZING RAIN. AS SUCH...ALLOWED THE WINTER WEATHER ADVISORY TO EXPIRE AT 10 AM. OTHER THAN THAT...TWEAKED THE NEAR TERM FORECAST TO BETTER REFLECT OBSERVED TRENDS. THROUGH THE 28/11Z RAP AND HRRR HAD A DECENT HANDLE ON RAINFALL TIMING...AS DID THE 06Z NAM. INCORPORATED THOSE SOURCES INTO THIS FORECAST UPDATE. WILL NEED TO KEEP AN EYE ON MAX TEMPERATURES EARLY THIS AFTERNOON. NOW THAT THE WARM FRONT HAS PUSHED NORTH...IF THE TIMING OF THICKER CLOUDS IS SLOWER THAN CURRENT FORECAST THEN THOSE WILL NEED TO BE BUMPED HIGHER. COVERAGE OF SHOWERS THIS AFTERNOON SHOULD BE SCATTERED SO NOT EXPECTING A WASHOUT BY ANY MEANS. AS SURFACE LOW MOVES NORTHEAST THROUGH THE ST LAWRENCE RIVER VALLEY...WARM SECTOR OVERSPREADS SOUTHERN NEW ENGLAND WITH TEMPS RISING WELL INTO THE 50S AND POSSIBLY NEAR 60 THIS AFTERNOON. THIS IS COURTESY OF A STRONG LOW LEVEL SOUTHWEST JET OF 55-65 KT. THIS WILL RESULT IN WINDY CONDITIONS ACROSS THE REGION WITH STRONGEST WINDS PER BUFKIT NAM SOUNDINGS ACROSS NORTHEAST MA WITH GUSTS UP TO 35 KT/40 MPH. NOT QUITE WIND ADVISORY CRITERIA BUT NEVERTHELESS WINDY CONDITIONS. LESS MIXING ELSEWHERE WILL RESULT IN LOWER WIND SPEEDS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... TONIGHT... COLD FRONT SLIPS OFFSHORE ALONG WITH DEEP LAYER MOISTURE. COLUMN BEGINS TO DRY YIELDING PARTIAL CLEARING ESPECIALLY NORTHERN MA AND SOUTHWEST NH WITH MID TO HIGH CLOUDS ACROSS CT/RI AND SOUTHEAST MA. POST FRONTAL AIRMASS NOT COLD AT ALL WITH MINS TONIGHT ONLY IN THE U30S TO M40S...WARMER THAN NORMAL! SATURDAY... DRY TO START ALONG WITH SOME PARTIAL SUNSHINE ESPECIALLY NORTHERN MA INTO SOUTHWEST NH. ALTHOUGH THIS WILL BE SHORT LIVED AS FRONTAL BOUNDARY OFFSHORE BEGINS TO MOVE NORTHWARD AS LOW PRES DEVELOPS ON THE FRONT OVER THE MID ATLC REGION. WARM CONVEYOR BELT RAINS BEGIN TO MOVE NORTHWARD INTO CT/RI AND SOUTHEAST MA DURING MID TO LATE AFTERNOON. GOOD MODEL AGREEMENT HERE ON TIMING ONSET OF PRECIP. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... * MORE SEASONABLE TEMPS EXPECTED THROUGH THE LONG TERM * HEAVY RAIN LIKELY WITH COASTAL STORM THIS WEEKEND THE 00Z MODELS ARE IN REASONABLY GOOD AGREEMENT ON THE SYNOPTIC PATTERN. MAIN DIFFERENCES LIE IN THE EXACT TRACK AND SPEED OF A FAIRLY STACKED SYSTEM MOVING OFF THE MID-ATLANTIC COAST AND NORTHEASTWARD TOWARDS SOUTHERN NEW ENGLAND. THE 12Z ECMWF IS FASTER AND A BIT FARTHER NORTH WHILE THE 00Z NAM IS SLOWER AND FARTHER SOUTH. THE 00Z GFS IS A GOOD MIDDLE GROUND SOLUTION AND IS MORE IN LINE WITH THE ENSEMBLE MEANS SO WILL LEAN MORE TOWARDS THE GFS TRACK FOR THIS STORM. THIS COASTAL STORM WILL BE THE MAJOR FEATURE IN THE LONG TERM WITH SIGNIFICANT IMPACTS ON SOUTHERN NEW ENGLAND THROUGH THE WEEKEND AND INTO TUESDAY MORNING. THROUGHOUT THE REST OF THE LONG TERM...A MID LEVEL RIDGE BUILDS OVER SOUTHERN NEW ENGLAND AND QUIET...DRY WEATHER IS EXPECTED THROUGH THE MIDDLE OF THE WEEK. SATURDAY NIGHT THROUGH MONDAY...LOW PRESSURE MOVES OFFSHORE NORTH CAROLINA AND MOVES NORTHEAST TO NEAR THE 40/70 BENCHMARK. AS STATED ABOVE...THERE ARE SOME DIFFERENCES IN THE MODELS BUT AM LEANING TOWARDS THE GFS. ALL MODELS...INCLUDING THE ENSEMBLES...ARE INDICATING A HIGH LIKELIHOOD OF 2 TO 4 INCHES OF RAIN ACROSS SOUTHERN NEW ENGLAND. IN ADDITION...PWAT VALUES ARE 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL...SO HEAVY RAIN IS LIKELY AT TIMES. DESPITE HOW DRY ITS BEEN OVER THE LAST MONTH...JUST OVER AN INCH OF PRECIP FOR THE MONTH OF MARCH...THIS AMOUNT OF RAIN OVER A 36 TO 48 HOUR TIME FRAME IS LIKELY TO PRODUCE AT LEAST URBAN AND POOR DRAINAGE FLOODING. RIVER BASINS HAVE A DECENT CAPACITY BECAUSE ITS BEEN DRY...BUT WE WILL HAVE TO KEEP AN EYE ON THEM...PARTICULARLY IF WE GET MORE THAN 2 TO 3 INCHES OF RAIN. WHILE MOST OF THE PRECIP IS EXPECTED TO BE RAIN...AS THE LOW MOVES OUT TO SEA AND COOLER AIR GETS DRAWN DOWN INTO THE REGION ON NORTHERLY FLOW...COULD SEE A PERIOD OF WINTRY WEATHER MONDAY AS PRECIP COMES TO AN END. STILL SOME UNCERTAINTY WITH THIS STORM SO WILL NEED TO KEEP AN EYE ON THE MODEL TRENDS OVER THE NEXT DAY OR SO. TUESDAY AND BEYOND...A MID LEVEL RIDGE BUILDS OVER THE NORTHEAST WITH A HIGH LIKELIHOOD OF DRY WEATHER AND SEASONABLE TEMPERATURES. THERE IS A LOW PROBABILITY OF SOME SHOWERS AS A COUPLE OF LOW PRESSURE SYSTEMS MOVE THROUGH THE GREAT LAKES AND INTO QUEBEC. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. FORECAST CONFIDENCE THIS PERIOD IS MODERATE TO HIGH. CIGS AND VSBYS BASED ON AN EVEN BLEND OF NAM/MET/GFS/MAV DATA SETS. REMAINDER OF THE FORECAST WAS A BLEND OF ALL MODEL GUIDANCE. WIND FORECAST MORE WEIGHTED TOWARD HI RES NAM. TODAY...VFR TO START WITH CIGS SLOWLY LOWERING TO MVFR THIS AFTERNOON IN SCATTERED SHOWERS. MAIN ISSUE TODAY WILL BE GUSTY SW WINDS THIS AFTERNOON. G35 KT POSSIBLE OVER EASTERN MA WITH G25-30KT ELSEWHERE. LESS SURFACE WIND ALONG THE SOUTH COAST INCLUDING CAPE COD WHICH WILL RESULT IN LLWS WITH SW WIND 50-60 AT 2 KFT. TONIGHT...FRONT SLIPS SOUTH OF NEW ENGLAND. MVFR/IFR SOUTH COAST IMPROVING TO VFR LATE. ELSEWHERE MVFR IMPROVES TO VFR. ANY LINGERING RAIN SHOWERS ON THE SOUTH COAST MOVE OFFSHORE LATER IN THE EVENING. SATURDAY...VFR AND DRY TO START BUT THEN LOWERING TO MVFR AS RAIN OFF THE SOUTH COAST COMES ONSHORE LATER IN THE AFTERNOON FROM SOUTH TO NORTH. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SW WINDS MAY GUSTS UP TO 35-40 KT THIS AFTERNOON. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT THROUGH MONDAY...MODERATE CONFIDENCE. AREAS OF MVFR CIGS/VSBYS IN HEAVY RAIN/FOG. A WINTRY MIX IS POSSIBLE LATE SUNDAY NIGHT INTO MONDAY AS PRECIP COMES TO AN END. TUESDAY...MODERATE TO HIGH CONFIDENCE. IMPROVING CONDITIONS AS RAIN MOVES OUT OF THE REGION. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. MODERATE TO HIGH FORECAST CONFIDENCE THRU SAT NIGHT. TODAY... INCREASING SW WINDS AS COLD FRONT APPROACHES FROM THE WEST. SW WINDS GUSTS TO 25-30 KT WITH STRONGEST WIND NEAR SHORE GIVEN WARM LAND TEMPS. MODERATE RISK OF GUSTS 35-40 KT NORTH OF PLYMOUTH TO CAPE ANN THIS AFTERNOON. THUS HAVE ISSUED A GALE WARNING FOR THIS AREA AND SCA FOR ALL OTHER WATERS. SCATTERED RAIN SHOWERS. TONIGHT... COLD FRONT SLIPS OFFSHORE WITH WINDS DIMINISHING AND SHIFTING FROM SW TO WNW BY MORNING. SATURDAY... WARM FRONT LIFTS NORTH WITH INCREASING SOUTH WINDS ACROSS THE SOUTH OCEAN WATERS. RAIN ALSO OVERSPREADS SOUTHERN WATERS. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT THROUGH MONDAY...LOW TO MODERATE CONFIDENCE. GALE WARNINGS WILL LIKELY BE NEEDED FOR SOME OF THE COASTAL WATERS AS LOW PRESSURE MOVES OVER THE WATERS. SEAS INCREASE TO 10 TO 15 FEET ON THE OUTER WATERS. VISIBILITIES WILL LIKELY BE LIMITED AT TIMES IN HEAVY RAIN AND FOG. TUESDAY...WINDS AND SEAS DIMINISH AS WEAK HIGH PRESSURE BEGINS TO BUILD OVER THE WATERS. && .TIDES/COASTAL FLOODING... INCREASING SPRING TIDE WILL BE OCCURRING OVER THIS WEEKEND WITH TIDES REACHING BETWEEN 11.2 AND 11.5 AT HIGH TIDE IN BOSTON. AS A COASTAL STORM AFFECTS THE REGION OVER THE WEEKEND...WINDS WILL GENERALLY BE IN A NORTHERLY TO NORTHEASTERLY DIRECTION. WITH THESE WIND DIRECTIONS EXPECT THE MOST VULNERABLE COASTLINES WILL BE THE NORTH FACING BEACHES OF CAPE COD AS WELL AS NANTUCKET. HOWEVER...WITH THE EXPECTED STRENGTH OF THE WINDS AND AN UNCERTAIN TRACK...COASTAL FLOODING IS POSSIBLE ALONG THE ENTIRE EAST COAST OF MASSACHUSETTS. BEACH EROSION IS A CONCERN AS WELL GIVEN MULTIPLE TIDE CYCLES WILL BE IMPACTED. THE MOST LIKELY TIDE CYCLES TO RESULT IN FLOODING ARE THE SUNDAY NIGHT HIGH TIDE AND POSSIBLY THE MONDAY MIDDAY HIGH TIDE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR ANZ231>234. GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ230-251. SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ236. SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ235-237- 250-254>256. && $$ SYNOPSIS...NOCERA/RLG NEAR TERM...BELK/NOCERA/RLG SHORT TERM...NOCERA LONG TERM...DUNTEN AVIATION...NOCERA/DUNTEN MARINE...NOCERA/DUNTEN TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
332 PM EDT FRI MAR 28 2014 .DISCUSSION... ...ROUND OF STORMS OVERNIGHT WITH HEAVY RAIN AND GUSTY WINDS... TONIGHT...MCS MOVING OFF THE LA COAST AND FL PANHANDLE THIS AFTERNOON. CONVECTION PROPAGATING SOUTH INTO GREATER INSTABILITY BUT AWAY FROM BEST MID/UPPER LVL WIND FIELD. SHORT RANGE GUIDANCE...HRRR RAP AND LOCAL ARW SHOW MCS OR REDEVELOPED CONVECTION ALONG ITS OUTFLOW BNDRY PUSHING INTO NRN PORTIONS OF FCST AREA OVERNIGHT...MAINLY AFTER MIDNIGHT. GUIDANCE ALSO RELATIVELY CONSISTENT IN WEAKENING CONVECTION OVERALL ONCE MCS GETS AWAY FROM STRONG FORCING PROVIDED BY COUPLED UPPER JET MCS FEATURE IS UNDER INFLUENCE CURRENTLY. STILL...ACTVTY WILL HAVE 25-30KT H8 WINDS AT ITS DISPOSAL AND CONVECTIVE DOWNDRAFTS WILL HAVE POTENTIAL FOR STRONG WIND GUSTS. STRONGEST STORMS WILL BE ACROSS NORTHERN SECTIONS. HAVE INTRODUCED MORE OF A PCPN GRADIENT FROM NORTH TO SOUTH BASED ON CURRENT MDL TRENDS. SATURDAY...PLENTY OF LYRD CLOUDINESS WILL BE ACROSS AREA WITH SCT SHRA IN THE MORNING. ATMOSPHERE WILL BE SLOW TO REGROUP INTO DIURNAL PHASE DUE TO LOSS OF HEATING WITH EXTENSIVE CLOUD COVER. MODELS MUCH LESS IN AGREEMENT IN THIS TIME PERIOD IN PART DUE TO CONVECTIVE DEBRIS AND LOCATION OF RESIDUAL VORT ASSCD WITH OLD MCS. SFC FRONT WILL APPROACH AREA FROM NORTH LATE IN DAY AS SFC LOW RAPIDLY INTENSIFIES OVER THE MID ATLC. HAVE LARGELY GONE WITH GFS POPS...HIGH CHC AREA WIDE...BUT HAVE GONE WELL BELOW GUIDANCE TEMPS DUE TO AFOREMENTIONED CLOUDS. SAT NIGHT-SUN...UPPER LEVEL LOW SWINGS THROUGH THE EAST COAST OVERNIGHT SAT DRIVING THE PARENT LOW OFF THE MID-ATLANTIC COAST AND THE ASSOCIATED COLD FRONT THROUGH THE FLORIDA PENINSULA. SCATTERED SHOWERS AND A FEW THUNDERSTORMS POSSIBLE IN THE EVENING AHEAD OF THE ACTUAL FRONT...THOUGH HOW MUCH ACTIVITY THAT OCCURS DURING THE DAY MAY AFFECT STABILITY INTO THE EVENING HOURS. PRECIPITATION TAPERING OFF TOWARDS DAYBREAK WITH MOSTLY SUNNY SKIES AND DRY CONDITIONS FOR SUNDAY. MIN TEMPS SAT NIGHT WILL BE IN THE MID 50S NORTH TO UPPER 60S/LOW 70S AROUND LAKE OKEECHOBEE/TREASURE COAST WHERE FRONT WILL JUST BE CLEARING AROUND SUNRISE SUN. BREEZY NORTHWEST WINDS ON SUN WILL BRING MAX TEMPS DOWN A FEW DEGREES FROM SAT INTO SEASONABLE MID-UPPER 70S. FROM PREVIOUS DISCUSSION MON-NEXT FRI...HIGH PRESSURE CENTER SHOULD DROP INTO NORTH FLORIDA MON THEN ONLY GRADUALLY SLIDE SEAWARD INTO LATE WEEK. ONSHORE FLOW WILL COMMENCE BUT ONLY SLOWLY MODIFY THE INITIALLY VERY DRY AIR MASS. THE 00Z GFS INDICATED IT REMAINING DRY ENOUGH TO PRECLUDE POPS THROUGH THE PERIOD. WITH THE HIGH PRESSURE NEARBY MON MORNING TEMPS LOOK A LITTLE BELOW NORMAL...THEN A GRADUALLY MODERATION TO A LITTLE ABOVE NORMAL IS INDICATED. && .AVIATION... MAINLY VFR CONDITIONS OVERNIGHT WITH EXCEPTION OF PERIOD OF CONVECTIVE ACTVTY MOVING ACROSS MOST LOCATIONS OVERNIGHT. WILL RESULT IN 2-3 HOUR PERIOD OF MVFR OR IFR CONDITIONS WITH BRIEF HVY RAIN AND GUSTY WINDS. && .MARINE... TONIGHT-SAT...WIND SPEEDS HAVE DROPPED BLO SCA AS RIDGE BUIDLS TO THE EAST. SEAS WILL SUBSIDE GDLY WITH SCEC TO FOLLOW SCA ENDING LATE THIS AFTN. SOME STRONG STORMS WITH GUSTY WINDS TO MOVE OFFSHORE TONIGHT AND AGAIN ON SATURDAY. SUN...COLD FRONT PUSHES THROUGH THE WATERS SAT NIGHT WITH WINDS BECOMING NE AROUND 20KTS BY DAYBREAK SUN WITH UP TO 25KTS WITH INITIAL SURGE ESPECIALLY OVER OFFSHORE WATERS NORTH OF SEBASTIAN INLET. WINDS DIMINISH THROUGH THE DAY ON SUN AS HIGH PRESSURE SLIDES INTO THE EASTERN US WITH NW WINDS BECOMING 15KTS BY THE AFTERNOON AND NORTH 10-15KTS OVERNIGHT. WIND DIRECTION WILL HELP BUILD SEAS OFFSHORE...WITH 6-8FT BY LATE MORN AND 4-6FT CLOSER TO THE COAST. MON-TUE...SURFACE HIGH CENTER SLIDES OVER CENTRAL PENINSULA DURING THE DAY ON MONDAY AND OFFSHORE TUE WILL CAUSE WINDS TO VEER TO THE NORTHEAST/EAST ON MON AND THEN TO THE EAST ON TUE. SPEEDS LOOK CLOSE TO 10 KNOTS EXCEPT MAYBE 10-15 KNOTS IN THE SOUTH ON MON. SEAS INITIALLY 4-6FT OFFSHORE ON MON DIMINISHING 2-4FT BY TUES. && .FIRE WEATHER... SUN-TUE...POST-FRONTAL NORTHWEST FLOW WILL BRING IN A MUCH DRIER AIRMASS FOR SUNDAY WITH MIN RH VALUES BELOW 30 PERCENT FOR MOST OF EAST CENTRAL FLORIDA. SUSTAINED WINDS WILL GENERALLY BE AROUND 10-15MPH...THOUGH OCCASIONAL HIGHER GUSTS WILL BE POSSIBLE EARLIER IN THE DAY. MIN RH IS FORECAST BELOW 35 PERCENT IN THE NORTH INTERIOR ON MON...BUT NORTHEAST/EAST WINDS WILL DROP OFF BELOW 10 MPH. && .PRELIMINARY POINT TEMPS/POPS... DAB 67 82 58 75 / 70 50 40 0 MCO 67 83 61 77 / 60 50 30 0 MLB 70 83 65 76 / 60 50 40 0 VRB 66 83 67 76 / 60 50 40 10 LEE 66 82 58 75 / 70 50 30 0 SFB 68 83 60 77 / 70 50 30 0 ORL 68 83 60 76 / 70 50 30 0 FPR 70 83 69 76 / 50 50 40 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...LAKE WIND ADVISORY UNTIL 7 PM EDT THIS EVENING FOR COASTAL VOLUSIA-INDIAN RIVER-INLAND VOLUSIA-MARTIN-NORTHERN BREVARD- NORTHERN LAKE-OKEECHOBEE-ORANGE-OSCEOLA-SEMINOLE-SOUTHERN BREVARD-SOUTHERN LAKE-ST. LUCIE. AM...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20 NM- COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE- WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE. && $$ SHORT TERM/AVIATION...BLOTTMAN LONG TERM....MOSES
AREA FORECAST DISCUSSION
NWS MIAMI FL
132 PM EDT FRI MAR 28 2014 .AVIATION... KEPT THE FORECAST VFR THROUGH THE PERIOD AS CURRENT THINKING IS THAT ANY LOWER CONDITIONS WILL BE LATE SATURDAY MORNING OR DURING THE AFTERNOON. THE ONLY EXCEPT IS THAT THE HRRR DOES SHOW THE LINE OF CONVECTION CURRENTLY IN THE FL PANHANDLE TO APPROACH LAKE OKEECHOBEE AFT 04Z THIS EVENING AND THIS COULD BRING SOME SHRA EARLIER THAN IN THE FORECAST ESPECIALLY AT APF AND PBI. INSTABILITY WILL BE ON THE INCREASE TOO ON SATURDAY BUT MOST OF THE THUNDER THREAT APPEARS TO BE AFT 18Z. SURFACE WIND WILL SLOWLY DIMINISH THIS AFTERNOON AND THEN VEER TO A S-SSW DIRECTION EARLY SATURDAY AS THE COLD FRONT APPROACHES. KOB && .PREV DISCUSSION... /ISSUED 927 AM EDT FRI MAR 28 2014/ UPDATE... THE ONLY CHANGE MADE TO THE FORECAST WAS TO LOWER POPS THIS MORNING ACROSS THE REGION. LOW LEVEL MOISTURE WILL START TO INCREASE THIS AFTERNOON ALLOWING FOR A BETTER CHANCE OF SHOWERS. A THUNDERSTORM OR TWO CANNOT BE RULED OUT AS WELL MAINLY NEAR LAKE OKEECHOBEE. CHANCES OF SHOWERS WILL CONTINUE TO INCREASE TONIGHT OUT AHEAD OF AN APPROACHING COLD FRONT. PREV DISCUSSION... /ISSUED 732 AM EDT FRI MAR 28 2014/ AVIATION... MAIN CONCERN TODAY WILL BE GUSTY SOUTHEAST SURFACE WIND TO OCCASIONALLY OVER 20 KNOTS ALONG THE EAST WITH GRADIENT TOO STRONG FOR A WEST COAST SEA BREEZE. VFR CONDITIONS WILL PREVAIL WITH A FEW SHOWERS FROM TIME TO TIME BUT NOT ENOUGH COVERAGE FOR OTHER THAN VCSH IN THE FORECAST. KOB PREV DISCUSSION... /ISSUED 404 AM EDT FRI MAR 28 2014/ DISCUSSION... HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL CONTINUE TO RETREAT FURTHER TO THE NORTHEAST AND AWAY FROM THE FLORIDA PENINSULA THROUGH THE DAY. THIS WILL ALLOW A DEEPER MOISTURE AXIS TO PUSH INTO THE AREA WELL AHEAD OF A DEVELOPING AREA OF LOW PRESSURE ACROSS SOUTHEAST TEXAS. THIS MEANS INCREASING SHOWER CHANCES ACROSS THE AREA THIS AFTERNOON. A FEW THUNDERSTORMS MAY ALSO BE POSSIBLE MAINLY ACROSS THE LAKE OKEECHOBEE REGION AS A FEW MID LEVEL IMPULSES PASS BY. PRECIPITATION COVERAGE IS EXPECTED TO INCREASE TONIGHT OUT AHEAD OF AN APPROACHING COLD FRONT IN THE CENTRAL GULF OF MEXICO. THE ECMWF CURRENTLY DEPICTS LESS QPF OUTPUT THAN THE GFS...SO WENT WITH A COMPROMISE FOR NOW WITH REGARD TO POPS THROUGH THE NIGHT. BY SATURDAY A HIGHLY AMPLIFIED H5 SHORTWAVE WILL DIG SOUTHEAST ACROSS THE MISSISSIPPI VALLEY AND INTO THE APPALACHIANS. AS IT DOES...ITS ASSOCIATED SURFACE LOW WILL DEEPEN AND PUSH NORTHEAST AND INTO THE OHIO VALLEY. THIS WILL PUSH THE COLD FRONT ACROSS THE FLORIDA PENINSULA LATE SATURDAY AND INTO SUNDAY WITH ADDITIONAL SHOWERS AND THUNDERSTORMS POSSIBLE. CONVECTIVE PARAMETERS CONTINUE TO LOOK MEAGER WITH THIS SYSTEM AND BETTER DYNAMICS WILL BE WELL NORTH OF THE AREA. ALSO THE FRONTAL PASSAGE LOOKS TO TAKE PLACE OVERNIGHT SATURDAY INTO SUNDAY WHICH WOULD ALSO BE UNFAVORABLE FOR ANY STRONG THUNDERSTORM DEVELOPMENT. THE FRONT AND ALL ASSOCIATED PRECIPITATION SHOULD EXIT THE AREA BY MIDDAY SUNDAY GIVING WAY TO DRIER AND MUCH MORE MILD TEMPERATURES UNDER NORTHERLY FLOW. HIGH PRESSURE WILL THEN DOMINATE THROUGH MOST OF THE UPCOMING WEEK WITH CONTINUED DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. THE GFS HINTS AT ANOTHER FRONT APPROACHING SOUTH FLORIDA BY THE END OF NEXT WEEK BRINGING ANOTHER ROUND OF SHOWERS BUT THE ECMWF KEEPS DRY UPPER RIDGING AND SOUTHEAST FLOW. AVIATION... VFR WITH BREEZY CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE DAY AS THE PRESSURE GRADIENT OVER SOUTH FLORIDA CONTINUES TO REMAIN TIGHT BETWEEN A HIGH TO THE ENE AND A LOW DEVELOPING OVER TEXAS. WITH THE FLOW SOUTHEASTERLY AND PLENTY OF MOISTURE IN THE ATMOSPHERE, THERE WILL BE A CHANCE OF SHOWERS. HOWEVER, THERE IS HIGH UNCERTAINTY WITH THE COVERAGE AND LOCATION. BEST GUESS IS MORE IN THE LAKE REGION AND NORTH, INTO CENTRAL FLORIDA. SO, NO MENTION OF RAIN IN THE TAFS AT THIS TIME, ALTHOUGH THERE IS STILL A SLIGHT POSSIBILITY OF A SHOWER AT A TAF SITE THIS AFTERNOON, ESPECIALLY KPBI AND EVEN KAPF. MARINE... GUSTY SOUTHEASTERLY WINDS WILL CONTINUE ACROSS THE ATLANTIC WATERS THROUGH THE MORNING WITH 6 TO 8 FOOT SEAS. FLOW WILL THEN BECOME MORE SOUTHERLY AND THEN SOUTHWESTERLY BY SATURDAY AS A COLD FRONT APPROACHES. THIS WILL ALLOW SEAS TO DIMINISH CONSIDERABLY. WINDS AND SEAS WILL THEN QUICKLY INCREASE AGAIN BEHIND THE FRONT ON SUNDAY INTO MONDAY. && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR FLZ168-172- 173. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
406 PM EDT FRI MAR 28 2014 .SYNOPSIS... AN AREA OF LOW PRESSURE WILL DEVELOP TO THE WEST TONIGHT...PUSHING A COLD FRONT TOWARD THE REGION. THE COLD FRONT WILL CROSS THE AREA SATURDAY EVENING...FOLLOWED BY DRY HIGH PRESSURE INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... REST OF THE AFTERNOON AND TONIGHT...THE ONGOING COVERAGE OF SHOWERS CONTINUES TO FAVOR MOSTLY SOUTHEAST GEORGIA AND THE FAR EASTERN AREA INCLUDING THE COASTAL WATERS AND EASTERN CHARLESTON COUNTY. CONVECTION CONTINUES TO BE QUITE SHALLOW THANKS TO THE MID LEVEL SUBSIDENCE INVERSION NOTED IN THE MORNING SOUNDING. LOOKING AT REGIONAL RADAR IMAGERY...THE HRRR CONTINUES TO BE THE MODEL BEST HANDLING THE ONGOING DEEPER CONVECTION ALONG THE GULF AND THE SHOWER ACTIVITY ACROSS THE FORECAST AREA. IT KEEPS SHOWERS GOING ACROSS THE FORECAST AREA INTO THE EARLY PART OF THE OVERNIGHT ASSOCIATED WITH A PASSING MID LEVEL SHORTWAVE NOTED IN WATER VAPOR IMAGERY. I HAVE THEREFORE CONTINUED TO CARRY LIKELY TO CATEGORICAL POPS TO THE WEST OVER THE NEXT FEW HOURS...WITH A BAND OF LIKELY AND HIGH CHANCE POPS MOVING ACROSS FROM WEST TO EAST THROUGH LATE TONIGHT. THE MODELS ARE PERSISTENT IN SHOWING AN AREA OF IMPROVED MID LEVEL LAPSE RATES AND NEGATIVE SHOWALTER INDICES NOSING IN FROM THE WEST...SO ELEVATED CONVECTION REMAINS A POSSIBILITY. A SLIGHT CHANCE OF THUNDER CONTINUES IN THE FORECAST. BY SATURDAY MORNING...IT APPEARS WE WILL BE IN A BIT OF A LULL FOR PRECIPITATION. THE MID/UPPER LEVELS BEGIN TO DRY OUT A BIT AND WE MAY EVEN SEE A BRIEF PERIOD OF SOME NVA ALOFT IN THE WAKE OF THE DEPARTING SHORTWAVE. THE GENERAL FLOW REGIME WILL CONTINUE TO BE SOUTHERLY IN THE LOW LEVELS AHEAD OF THE APPROACHING FRONT. THIS WILL RESULT IN A MILD AND MOIST NIGHT IN THE ONSHORE FLOW. EXPECT LOWS ONLY IN THE LOW TO MID 60S. ALSO...I HAVE ADDED PATCHY FOG EVERYWHERE OVERNIGHT. THERE WILL LIKELY BE ENOUGH SURFACE LEVEL FLOW TO PREVENT FOG FROM BECOMING TOO WIDESPREAD...SO PATCHY FOG SHOULD COVER IT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... PRIMARY FORECAST ATTENTION FOCUSES ON THE POTENTIAL FOR SEVERE WEATHER SATURDAY. STARTED THE DAY WITH CHANCE POPS AS MORE WIDESPREAD SHOWERS SHOULD HAVE EXITED TO THE E/NE. THEN...POPS RAMP UP TO LIKELY BY EARLY/MID AFTERNOON AS AN AMPLIFYING UPPER TROUGH/ASSOCIATED COLD FRONT APPROACH THE REGION FROM THE WEST. FORCING FOR ASCENT AHEAD OF THESE FEATURES...INCLUDING HEIGHT FALLS AND UPPER DIVERGENCE...700-500 LAPSE RATES EXCEEDING 6 C/KM AND SUB-ZERO SHOWALTER INDICES AND 0-6 KM BULK SHEAR 40-50 KNOTS ALL SUGGEST THE POTENTIAL FOR ONE OR MULTIPLE BANDS OF PRE-FRONTAL CONVECTION PUSHING THROUGH THE REGION WITH AT GUSTY WINDS AND LOCALLY HEAVY RAINFALL SATURDAY AFTERNOON/EVENING. FORECAST UNCERTAINTY CENTERS ON THE AMOUNT OF INSOLATION/WARMING AND ASSOCIATED DEGREE OF SURFACE-BASED INSTABILITY AHEAD OF THE COLD FRONT. THE 28/12Z NAM SUGGESTS THAT CLOUDS/PRECIPITATION WILL LIMIT INSTABILITY...AND THE RESULTING SEVERE THREAT WILL REMAIN LIMITED TO ISOLATED/BRIEF DAMAGING WIND GUSTS. ON THE OTHER HAND...IF AGGRESSIVE DRY SLOTTING BREAKS UP CLOUDS AND ALLOWS TEMPS TO RECOVER TO AROUND 80F AS SUGGESTED BY 28/12Z GFS AND EURO SOLUTIONS...RESULTING SURFACE BASED CAPE 1000-1800 J/KG WILL COMBINE WITH FAVORABLE KINEMATIC PARAMETERS/SYNOPTIC FORCING TO SUPPORT A MORE SIGNIFICANT SEVERE WEATHER THREAT...PERHAPS IN THE FORM OF AN AFTERNOON/EARLY EVENING SQUALL LINE PRODUCING DAMAGING WIND GUSTS AND EVEN SOME LARGE HAIL/AN ISOLATED TORNADO. THE COLD FRONT AND ASSOCIATED PRECIPITATION WILL PUSH OFFSHORE SATURDAY NIGHT. POPS RAMP DOWN STEADILY FROM CHANCE/LIKELY EARLY TO VIRTUALLY ZERO PERCENT LATE. A SURGE OF COOLER DRIER AIR...DRIVEN BY GUSTY NORTHWEST WINDS...WILL PUSH TEMPERATURES INTO THE MID/UPPER 40S AT MOST LOCATIONS BY SUNDAY MORNING. BETWEEN DEEPENING LOW PRESSURE EXITING THE MID ATLANTIC COAST AND HIGH PRESSURE BUILDING FROM THE W/NW...SUNDAY WILL FEATURE BREEZY AND DRY CONDITIONS ACCOMPANIED BY TEMPERATURES IN THE UPPER 60S TO LOWER 70S...JUST A SHADE BELOW NORMAL FOR LATE MARCH. AS HIGH PRESSURE SHIFTS EAST AND WINDS DIMINISH SUNDAY NIGHT...RADIATIONAL COOLING WILL SUPPORT LOW TEMPS IN THE LOWER TO MID 40S MOST LOCATIONS. WELL INLAND...THE COOLEST LOCATIONS COULD BOTTOM OUT IN THE UPPER 30S...BUT THE PROBABILITY FOR ANY FROST WILL REMAIN VERY LOW. MONDAY...UNDER HIGH PRESSURE TEMPERATURES WILL RECOVER INTO AT LEAST THE MID 70S AWAY FROM THE BEACHES. A SEA BREEZE WILL DEVELOP AND WILL PUSH INLAND MONDAY AFTERNOON. LAKE WINDS...GUSTY WINDS AND CHOPPY WAVES COULD DEVELOP ON LAKE MOULTRIE...ESPECIALLY SATURDAY NIGHT AND SUNDAY. A LAKE WIND ADVISORY COULD EVENTUALLY BE REQUIRED. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A BROAD UPPER LEVEL RIDGE WILL PREVAIL MONDAY NIGHT THROUGH THURSDAY WITH DRY HIGH PRESSURE AT THE SURFACE. THIS WILL RESULT IN ABOVE NORMAL TEMPERATURES WITH HIGHS CLIMBING INTO THE UPPER 70S OR LOWER 80S AND LOWS MAINLY IN THE 50S. THE UPPER RIDGE BREAKS DOWN ON FRIDAY WITH A WEAK COLD FRONT POSSIBLY MOVING IN FROM THE WEST. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... EXPECT UNSETTLED CONDITIONS THROUGH 18Z SATURDAY. SCATTERED TO NUMEROUS SHOWERS HAVE DEVELOPED NEAR THE TERMINALS THIS AFTERNOON SO A VCSH HAS BEEN ADDED. ALSO...TO ACCOUNT FOR DIRECT IMPACTS...MVFR CONDITIONS HAVE BEEN ADDED IN A TEMPO GROUP THAT RUNS THROUGH LATE AFTERNOON MAINLY FOR CEILINGS BUT ALSO FOR VISIBILITIES AS RAINFALL BRIEFLY BECOMES MODERATE. THERE IS A LOW CHANCE FOR A RUMBLE OF THUNDER...BUT THE PROBABILITY IS TOO LOW TO INCLUDE IN THE FORECAST. THIS EVENING AND THROUGH THE OVERNIGHT...IT IS BECOMING INCREASINGLY LIKELY THAT WIDESPREAD MVFR CEILINGS WILL DEVELOP. I HAVE TIMED THIS INTO KSAV AT 00Z AND INTO KCHS AT 03Z. WE WILL LIKELY SEE ADDITIONAL PERIODS OF SHOWERS AT BOTH SITES LATE THIS EVENING BEFORE THIS AREA OF PRECIPITATION PUSHES OFF TO THE EAST LATE. GUIDANCE CONTINUES TO INDICATE A LOW TO MODERATE CHANCE OF IFR CONDITIONS LATE TONIGHT. PROBABILITIES ARE HIGHEST AT KSAV...BUT I/M NOT READY TO COMMIT TO PREVAILING IFR THIS FAR OUT. I HAVE TRENDED KSAV DOWN INTO THE LOW END MVFR RANGE STARTING AT 06Z AND CONTINUING THROUGH THE MID MORNING. CEILINGS SHOULD LIFT TO LOW END VFR MID/LATE SATURDAY MORNING. A COLD FRONT AND AN INCREASING POTENTIAL FOR THUNDERSTORMS ALONG IT WILL APPROACH SATURDAY AFTERNOON. SHOWERS OUT AHEAD OF THE FRONT WILL DEVELOP FIRST AT KSAV AND WINDS WILL BEGIN TO PICK UP AND BE GUSTY OUT OF THE SOUTH. THIS WILL ALSO HAPPEN AT KCHS...THOUGH LATER...AND HAS NOT BEEN INCLUDED AT THIS TIME. EXTENDED AVIATION OUTLOOK...OCCASIONAL FLIGHT RESTRICTIONS POSSIBLE SATURDAY AFTERNOON AND EVENING IN SHOWERS/SCATTERED THUNDERSTORMS. VFR CONDITIONS EXPECTED THEREAFTER. BREEZY CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY. && .MARINE... REST OF THE AFTERNOON AND TONIGHT...PERSISTENT SOUTHEASTERLY FLOW HAS CONTINUED TODAY BETWEEN THE HIGH OVER THE OPEN ATLANTIC AND THE COLD FRONT TO THE WEST. THE COOL SEA SURFACE TEMPERATURES...ESPECIALLY OVER THE SHELF WATERS...HAS PREVENTED WINDS FROM GETTING MUCH STRONGER THAN 10 TO 15 KT THUS FAR. ONE SURPRISE HAS BEEN THE RAPID INCREASE IN SEAS...PRIMARILY COMPRISED OF A 7 SECOND SWELL. 41008 HAS REPORTED SEAS UP TO ALMOST 8 FT AND 41008 IS NOW REACHING TO AROUND 5 FT. DUE TO THESE OBSERVATIONS WE HAVE HOISTED A SMALL CRAFT ADVISORY FOR THE OUTER GEORGIA WATERS THAT STARTS NOW AND RUNS THROUGH THE NIGHT. 6 FT SEAS ARE EXPECTED TO DRAW CLOSER TO SHORE AND BEGIN GET INTO THE NEARSHORE WATERS ALONG THE CHARLESTON COUNTY COAST AFTER MIDNIGHT. A SMALL CRAFT ADVISORY HAS BEEN INITIALIZED AT THAT TIME AND RUNS INTO SATURDAY. OVERALL...WINDS WILL REMAIN IN THE 10-15 KT RANGE...PERHAPS UP TO 20 KT BEYOND 20 NM...THOUGH TONIGHT IN THE SOUTHERLY FLOW. ANOTHER CONCERN IN THE MOIST SOUTHERLY FLOW IS THE POTENTIAL FOR SEA FOG TO DEVELOP OVERNIGHT. I HAVE ADDED PATCHY FOG AFTER MIDNIGHT AS A RESULT. CONDITIONS WILL REMAIN FAVORABLE FOR SEA FOG UNTIL A COLD FRONT CROSSES THE WATERS WITH MUCH DRIER AIR SATURDAY EVENING. THE FORECAST INDICATES PATCHY FOG...BUT MORE WIDESPREAD FOG COULD PROMPT DENSE FOG ADVISORIES. SATURDAY THROUGH TUESDAY...ELEVATED SEAS WILL PERSIST...AND SOUTHERLY WINDS WILL INCREASE TO 15-20 KT...WITH GUSTS TO 25 KT POSSIBLE BEYOND 20 NM...AHEAD OF AN APPROACHING COLD FRONT. AFTER COLD FROPA...SMALL CRAFT ADVISORY NORTHWEST WINDS/HAZARDOUS SEAS WILL PREVAIL THROUGH SUNDAY. W/NW WINDS WILL GRADUALLY DIMINISH SUNDAY NIGHT...AND HIGH PRESSURE WILL SHIFT OVER THE WATERS AND WILL PROVIDE MUCH LIGHTER WINDS AND SUBSIDING SEAS MONDAY-TUESDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM SATURDAY TO 5 PM EDT SUNDAY FOR AMZ352. SMALL CRAFT ADVISORY UNTIL 11 PM EDT SUNDAY FOR AMZ374. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM EDT SUNDAY FOR AMZ350. && $$ SYNOPSIS... NEAR TERM...BSH SHORT TERM...SPR LONG TERM...JRL AVIATION...BSH/SPR MARINE...BSH/SPR
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
246 PM EDT FRI MAR 28 2014 .PREV DISCUSSION... /ISSUED 1040 AM EDT FRI MAR 28 2014/ UPDATE... HAVE MADE SIGNIFICANT ADJUSTMENTS TO THE FORECAST TO ACCOUNT FOR LATEST THINKING WITH TODAYS WEATHER. AXIS OF PRECIPITATION IS FURTHER SOUTH THAN ORIGINALLY ANTICIPATED...AND PREVIOUS FORECAST POP AND WX GRIDS DID NOT MATCH THIS POSITIONING. OVERALL...MODEL GUIDANCE WITH THIS SYSTEM IS POOR...WITH VERY FEW DEPICTING THE CURRENT RADAR TRENDS WELL. HAVE OVERALL GONE WITH THE HRRR WHICH SEEMS TO HAVE A BETTER HANDLE ON THE CURRENT CONDITIONS. THE HRRR DOES SUGGEST MUCH OF THE COMPLEX IN MS/AL WILL ORGANIZE INTO THIS AFTERNOON...BECOMING MORE LINEAR IN NATURE...AND PUSHING ACROSS SOUTHWEST GEORGIA. ALTHOUGH THERE IS A QUESTION OF WHETHER THIS LINEAR CONVECTION WILL MATERIALIZE...THE HRRR CONTINUES TO SHOW MUCH OF NORTH GEORGIA CUT OFF FROM GULF MOISTURE...AND LIMITS THE AMOUNT OF PRECIP OVER THE NORTHERN SECTIONS OF THE CWA. AS A RESULT...HAVE CONTINUED THE TREND OF HIGHEST POPS ACROSS CENTRAL GEORGIA INTO THE OVERNIGHT PERIOD. WILL CONTINUE TO UPDATE THE GRIDS AS NECESSARY...ESPECIALLY THE NEXT 24 HOURS. 31 PREV DISCUSSION... /ISSUED 717 AM EDT FRI MAR 28 2014/ PREV DISCUSSION... /ISSUED 341 AM EDT FRI MAR 28 2014/ SHORT TERM /TODAY THROUGH SATURDAY/... SURFACE ANALYSIS SHOWS A COLD FRONT STRETCHING FROM THE CENTRAL GREAT LAKES BACK THROUGH THE ARKLATEX. A LARGE AREA OF PRECIPITATION HAS DEVELOPED TO THE EAST OF THE BOUNDARY AN IS MOVING INTO NW PORTIONS OF THE CWFA. PRECIP WILL CONTINUE TO INCREASE FOR MUCH OF THE AREA TODAY AS THE FRONT SLOWLY PUSHES EASTWARD. THE NORTHERN END OF THE FRONT WILL MAKE SOME EASTWARD PROGRESS TODAY...WHILE THE SOUTHERN END WILL LAG UNTIL EARLY SATURDAY MORNING. A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE SOUTHERN TAIL OF THE FRONT TONIGHT...AND FINALLY HELP PUSH THE FRONT THROUGH THE CWFA ON SATURDAY. THE NORTHERN END OF THE FRONT WILL BECOME TEMPORARILY STATIONARY NEAR THE TN/GA BORDER THIS EVENING AND OVERNIGHT. EXPECT SHOWERS AND A FEW THUNDERSTORMS TO TRAIN ACROSS THE NORTHERN HALF OF THE CWFA...IN THE VICINITY OF THE BOUNDARY TONIGHT. MODELS SHOWING A BIT MORE INSTABILITY ACROSS THE SOUTHERN CWFA FOR THIS AFTERNOON THAN IN PREVIOUS RUNS. STILL...ONLY A COUPLE HUNDRED JULES OF CAPE. WILL KEEP THUNDER CHANCES AT A MINIMUM TODAY AND ONLY MENTION A SLIGHT CHANCE. EVEN THOUGH A BREAK IN THE WIDESPREAD PRECIPITATION IS EXPECTED THIS EVENING...THE CHANCES FOR THUNDER WILL SLIGHTLY INCREASE AS A MID LEVEL SHORTWAVE TRAVERSES THE AREA AND STEEPENS LAPSE RATES. STILL...SURFACE INSTABILITY WILL BE LIMITED...SO WILL CAP THE THUNDER WORDING AT A CHANCE. A BIT MORE INSTABILITY WILL BE PRESENT SATURDAY AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST PORTION OF THE CWFA. THIS AREA HAS THE POTENTIAL FOR SOME HEATING...WITH TEMPS IN THE LOWER TO MIDDLE 70S. SURFACE BASED CAPES SHOULD RANGE FROM 500 TO 1000 J/KG. THE BEST SHEAR SHOULD LAG...ALONG WITH THE FRONTAL BOUNDARY. HOWEVER...WILL NOT RULE OUT STRONG THUNDERSTORMS WITH ISOLATED SEVERE STORMS POSSIBLE. DAMAGING WIND GUSTS SHOULD BE THE PRIMARY MODE OF SEVERE WEATHER. NLISTEMAA LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... FOR THE MOST PART...SYSTEM THAT BRINGS RAIN TO THE AREA IN THE SHORT TERM SHOULD HAVE EXITED THE AREA BY THE BEGINNING OF THE LONG TERM. THE EXCEPTION TO THIS IS ACROSS FAR NORTHEAST GEORGIA AND THE FAR SOUTHEAST PART OF THE CWA WHERE SOME RAIN COULD LINGER THROUGH SATURDAY NIGHT. AT THIS POINT...IT APPEARS THE PRECIPITATION SHOULD END ACROSS THE NE GA MOUNTAINS BEFORE THE COOLER TEMPERATURES MOVE IN. AFTER THIS HIGH PRESSURE WILL DOMINATE THROUGH ABOUT MID WEEK. BOTH THE GFS AND THE ECMWF SUGGEST THE NEXT SYSTEM MOVING THROUGH IN THE LATER HALF OF THE WEEK. INSTABILITY VALUES SUPPORT THE MENTION OF THUNDER IN THE FORECAST THURSDAY INTO FRIDAY. 11 HYDROLOGY... ONE CONCERN FOR THE FORECAST PERIOD IS LOCALLY HEAVY RAINFALL. PWATS JUST UNDER AN INCH AND HALF WILL BE LIKELY THIS AFTERNOON THROUGH SATURDAY. THESE NUMBERS ARE VERY CLOSE TO BEING 2SD ABOVE NORMAL FOR THIS TIME OF YEAR. 6HR FFG GUIDANCE RANGES FROM AROUND 2 TO 3 INCHES ACROSS THE CWFA. STORM TOTAL PRECIP FROM TODAY THROUGH SATURDAY NIGHT AVERAGES AN INCH AND A HALF TO JUST ABOUT TWO AND THREE QUARTERS OF AN INCH. SINCE THE RAINFALL IS EXPECTED TO BE OVER A LONGER PERIOD OF TIME...FF ISN`T A MAJOR CONCERN AT THIS TIME. HOWEVER...WHERE THUNDERSTORMS REPEATEDLY TRAIN...SOME LOCALIZED FF IS POSSIBLE. DO EXPECT SOME RISES ON THE RIVERS BUT NOT CONFIDENT ENOUGH TO SAY IF RIVERS WILL GO INTO FLOOD YET. NLISTEMAA && .AVIATION... 18Z UPDATE... RAIN CONTINUES ACROSS THE AREA THIS AFTERNOON...AND TAF SITES ARE LARGELY IFR. ANTICIPATE THE IFR CIGS TO CONTINUE INTO THE OVERNIGHT PERIOD. ATL AND AHN AREA TAFS WILL SEE A BREAK IN THE RAIN UNTIL 05-06Z. MCN AND CSG CAN EXPECT TO SEE RAINFALL INTO THE EVENING HOURS. RAIN WILL TAPER OFF INTO THE OVERNIGHT PERIOD...AND START BACK UP AROUND 06-08Z. TS POTENTIAL FOR SATURDAY IS STILL LOW ENOUGH WHERE IT IS NOT ADVERTISED IN ANY TAFS AT THIS TIME. THE BEST TIMING WOULD BE FROM 15-20Z SATURDAY IN THE CSG AND MCN AREAS AND SOUTHWARD. SE WINDS WILL PERSIST THROUGH 10-12Z AS THE FRONT PUSHES THROUGH THE ATL AREA AND SHIFTS WINDS TO THE NW. CSG AND MCN WILL SEE THIS SHIFT CLOSER TO 14-16Z. SPEEDS WILL INCREASE TO 10-15KT WITH GUSTS TO 20-25KT BY LATE SATURDAY MORNING. //ATL CONFIDENCE...18Z UPDATE... MEDIUM CONFIDENCE ON ALL ELEMENTS. 31 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 63 54 72 42 / 100 60 70 5 ATLANTA 62 56 69 42 / 100 70 70 5 BLAIRSVILLE 57 52 65 37 / 100 70 80 10 CARTERSVILLE 61 56 69 41 / 100 80 70 5 COLUMBUS 64 60 73 47 / 100 70 60 5 GAINESVILLE 58 53 68 41 / 100 70 80 5 MACON 65 58 74 44 / 100 60 60 5 ROME 62 56 68 42 / 100 80 80 5 PEACHTREE CITY 63 56 71 41 / 100 70 70 5 VIDALIA 69 60 75 48 / 100 80 60 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...31 LONG TERM....BAKER AVIATION...31
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
200 PM EDT FRI MAR 28 2014 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL AS WEAK UPPER DISTURBANCES MOVE THROUGH THE AREA TODAY AND TONIGHT. A COLD FRONT WILL CROSS THE REGION SATURDAY AFTERNOON AND EVENING...FOLLOWED BY DRY HIGH PRESSURE THROUGH THURSDAY. A COLD FRONT MAY AFFECT THE AREA NEXT FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... EARLY THIS AFTERNOON...AS EXPECTED CONVECTION HAS REMAINED QUITE SHALLOW SO FAR AND HAS BEEN ON A BIT OF A DIMINISHING TREND AS IT PUSHES IN FROM THE WEST. THERE ARE TWO MAIN AREAS OF PRECIPITATION AT THIS POINT...THE ONE TO THE WEST ASSOCIATED WITH THE UPPER SHORTWAVE AND UPSTREAM CONVECTION...AND THE ONE TO THE EAST WHICH IS WHERE THE MORNING SHOWERS FIRST STARTED IN THE SOUTHERLY MOISTURE FEED. I HAVE MADE SOME TWEAKS TO POPS TO BETTER MATCH ONGOING CONDITIONS...AS WELL AS TEMPERATURES...BUT THE OVERALL FORECAST REMAINS ON TRACK. LATE THIS MORNING...CLOUDS HAVE STEADILY FILLED IN ACROSS THE FORECAST AREA WITH MUCH OF IT BECOMING OVERCAST NOW. THERE ARE STILL SOME BREAKS ON VISIBLE SATELLITE IMAGERY...BUT THESE SHOULD FILL IN THROUGH THE DAY ESPECIALLY AS MID/HIGH CLOUDS STREAM IN FROM ONGOING CONVECTION TO THE WEST. RADAR IMAGERY SHOWS PERIODIC SHOWERS MOVING ONSHORE IN THE SOUTHERLY FLOW...MAINLY AFFECTING CHARLESTON AND BERKELEY COUNTIES THIS MORNING. DIAGNOSING WHAT IS CURRENTLY GOING ON AROUND THE REGION...THERE IS A FAIRLY LARGE COMPLEX OF CONVECTION ONGOING ALONG THE GULF COAST FROM AROUND NEW ORLEANS TO THE WESTERN FLORIDA PANHANDLE. BASED ON REGIONAL RAOB/S THIS CONVECTION APPEARS TO BE ASSOCIATED WITH AN AREA OF ELEVATED INSTABILITY. THIS IS FURTHER SUPPORTED BY NEGATIVE SHOWALTER INDICES FROM THE RAP AND AN AREA OF ENHANCED MID LEVEL LAPSE RATES NOTED FROM THE SPC MESOANALYSIS PAGE. FOR INSTANCE...COMPARING THE 12Z KTLH AND KCHS SHOWS SIMILAR MID LEVEL ENVIRONMENTS OTHER THAN THE PROMINENT SUBSIDENCE INVERSION NOTED IN THE KCHS SOUNDING AT AROUND 650 MB. THIS INVERSION IS SUPPORTED BY INTERROGATING ALL TILTS RADAR OF THE CURRENT SHOWER ACTIVITY...WHICH SHOWS THE DEPTH OF REFLECTIVITY SHUTTING OFF AROUND 11 KFT...WHICH IS NEAR THE 650 MB LEVEL. SO THE BEST MID LEVEL ENVIRONMENT IS CERTAINLY TO OUR WEST AND SOUTHWEST AND BASED ON CURRENT HI-RES MODEL RUNS IT APPEARS THAT WILL CONTINUE THROUGH THE DAY. THE 11Z HRRR APPEARS TO BE HANDLING THE ONGOING CONVECTION THE BEST...AND THROUGH THE DAY IT TAKES THE MOST INTENSE UPSTREAM CONVECTION IN A SOUTHEASTWARD DIRECTION OVER THE FLORIDA PANHANDLE AND THE EASTERN GULF. THIS SEEMS REASONABLE AS THE BEST MID LEVEL ENVIRONMENT AND LATER SURFACE BASED INSTABILITY WILL BE TO THE SOUTH AND SOUTHEAST OF ITS CURRENT LOCATION. SO...FOR THE FORECAST AREA...THE THINKING IS THAT WE WILL CONTINUE TO SEE SHALLOW CONVECTION AT BEST. I HAVE ADJUSTED POPS ACCORDINGLY...AND THE SCHEME FAVORS THE EASTERN AREAS NOW AND THEN THE WESTERN AREAS LATER AS THE DIMINISHING UPSTREAM SHOWERS/CONVECTION ATTEMPT TO PUSH IN. WITH THE CLOUD COVER ONGOING AND EXPECTED...HIGH TEMPERATURES ARE TRICKY. I HAVE LOWERED VALUES MORE INTO THE LOW TO MID 70S...BUT THIS COULD BE ON THE LOW END IF WE GET MORE SUN THAN EXPECTED. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... TONIGHT...ATLANTIC HIGH PRESSURE WILL PREVAIL AS A COLD FRONT APPROACHES FROM THE TENNESSEE VALLEY AND DEEP SOUTH. SOUTHERLY FLOW WILL CONTINUE TO ADVECT DEEP MOISTURE INTO THE REGION. THE COMBINATION OF THE DEEP LAYERED MOISTURE...FORCING FOR ASCENT ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET...AND A POTENT SHORT WAVE PASSING ALOFT WILL SUPPORT SCATTERED TO NUMEROUS SHOWERS ACROSS THE AREA...ESPECIALLY LATE THIS EVENING AND OVERNIGHT. IN ADDITION...INSTABILITY PARAMETERS/MID LEVEL LAPSE RATES ARE SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORMS AS WELL. TEMPERATURES WILL NOT FALL SIGNIFICANTLY GIVEN THE SOUTHERLY FLOW AND CLOUD COVER...WITH LOWS EXPECTED TO BE AROUND 60 IN MOST AREAS. A POTENT UPPER SHORTWAVE WILL MOVE INTO THE CENTRAL APPALACHIANS ON SATURDAY. SOUTHWEST FLOW WILL STRENGTHEN CONSIDERABLY AS THE DAY WEARS ON...WITH 0-6 KM WINDS 40-45 KT BY 00Z SUN. THIS WILL ALSO INCREASE MOISTURE ACROSS THE AREA WITH PWATS ABOVE 1.50 INCHES BY 18Z SAT. A COLD FRONT IS EXPECTED TO SWEEP THROUGH THE AREA SATURDAY EVENING. THERE REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE DEGREE OF BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FRONT. GIVEN THE EXTENSIVE LOW-LEVEL MOISTURE ADVECTING INTO THE REGION DURING THE DAY WE WOULD EXPECT TO HAVE QUITE A BIT OF LOW STRATOCUMULUS IN PLACE. HOWEVER SOME OF THE GUIDANCE IS DEPICTING A WEAK DRY SLOT DURING THE MIDDAY HOURS AFTER A BATCH OF MORNING PRECIP MOVES THROUGH. BOTH THE GFS AND NAM ARE SHOWING 1500 J/KG CAPES WITH LIFTED INDICES BELOW -4C DURING THE AFTERNOON ACROSS SOUTHEAST GA. THIS COINCIDES WITH 40-45 KT OF BULK SHEAR. IT IS ALSO WORTH NOTING THAT THE STORM PREDICTION CENTER STILL SHOWS OUR ENTIRE FORECAST AREA WITHIN THE DAY 2 SLIGHT RISK. WE PLAN TO ADD MENTION OF POSSIBLE SEVERE WEATHER TO THE HAZARDOUS WEATHER OUTLOOK. STRONG LOW-LEVEL WARM ADVECTION AND PRE-FRONTAL COMPRESSION ON SATURDAY WILL PUSH HIGH TEMPS INTO THE UPPER 70S. THIS COULD POTENTIALLY BE TOO COOL IF SOME BREAKS DEVELOP IN THE CLOUDS. CONSIDERABLE COVERAGE OF SHOWERS AND THUNDERSTORMS IS EXPECTED THROUGH SATURDAY EVENING BEFORE PRECIP TAPERS OFF BEHIND THE FRONT. A SLIGHT COOL DOWN IS EXPECTED FOR SUNDAY DUE TO COLD ADVECTION WITH THE HIGH BUILDING IN...HOWEVER DOWNSLOPE FLOW WILL ALLOW TEMPS TO REACH 70 OR THEREABOUTS. A 30-35 KT GEOSTROPHIC WIND FIELD AND DEEP MIXING WILL RESULT IN BREEZY CONDITIONS ESPECIALLY DURING THE HOURS OF PEAK HEATING. DRY WEATHER WITH MODERATING TEMPERATURES EXPECTED ON MONDAY WITH HIGHS REBOUNDING INTO THE LOWER TO MIDDLE 70S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A BROAD UPPER LEVEL RIDGE WILL PREVAIL MONDAY NIGHT THROUGH THURSDAY WITH DRY HIGH PRESSURE AT THE SURFACE. THIS WILL RESULT IN ABOVE NORMAL TEMPERATURES WITH HIGHS CLIMBING INTO THE UPPER 70S OR LOWER 80S AND LOWS MAINLY IN THE 50S. THE UPPER RIDGE BREAKS DOWN ON FRIDAY WITH A WEAK COLD FRONT POSSIBLY MOVING IN FROM THE WEST. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... EXPECT UNSETTLED CONDITIONS THROUGH 18Z SATURDAY. SCATTERED TO NUMEROUS SHOWERS HAVE DEVELOPED NEAR THE TERMINALS THIS AFTERNOON SO A VCSH HAS BEEN ADDED. ALSO...TO ACCOUNT FOR DIRECT IMPACTS...MVFR CONDITIONS HAVE BEEN ADDED IN A TEMPO GROUP THAT RUNS THROUGH LATE AFTERNOON MAINLY FOR CEILINGS BUT ALSO FOR VISIBILITIES AS RAINFALL BRIEFLY BECOMES MODERATE. THERE IS A LOW CHANCE FOR A RUMBLE OF THUNDER...BUT THE PROBABILITY IS TOO LOW TO INCLUDE IN THE FORECAST. THIS EVENING AND THROUGH THE OVERNIGHT...IT IS BECOMING INCREASINGLY LIKELY THAT WIDESPREAD MVFR CEILINGS WILL DEVELOP. I HAVE TIMED THIS INTO KSAV AT 00Z AND INTO KCHS AT 03Z. WE WILL LIKELY SEE ADDITIONAL PERIODS OF SHOWERS AT BOTH SITES LATE THIS EVENING BEFORE THIS AREA OF PRECIPITATION PUSHES OFF TO THE EAST LATE. GUIDANCE CONTINUES TO INDICATE A LOW TO MODERATE CHANCE OF IFR CONDITIONS LATE TONIGHT. PROBABILITIES ARE HIGHEST AT KSAV...BUT I/M NOT READY TO COMMIT TO PREVAILING IFR THIS FAR OUT. I HAVE TRENDED KSAV DOWN INTO THE LOW END MVFR RANGE STARTING AT 06Z AND CONTINUING THROUGH THE MID MORNING. CEILINGS SHOULD LIFT TO LOW END VFR MID/LATE SATURDAY MORNING. A COLD FRONT AND AN INCREASING POTENTIAL FOR THUNDERSTORMS ALONG IT WILL APPROACH SATURDAY AFTERNOON. SHOWERS OUT AHEAD OF THE FRONT WILL DEVELOP FIRST AT KSAV AND WINDS WILL BEGIN TO PICK UP AND BE GUSTY OUT OF THE SOUTH. THIS WILL ALSO HAPPEN AT KCHS...THOUGH LATER...AND HAS NOT BEEN INCLUDED AT THIS TIME. EXTENDED AVIATION OUTLOOK...OCCASIONAL FLIGHT RESTRICTIONS POSSIBLE SATURDAY AFTERNOON AND EVENING IN SCATTERED SHOWERS AND THUNDERSTORMS. VFR CONDITIONS EXPECTED THEREAFTER. BREEZY CONDITIONS EXPECTED ON SUNDAY. && .MARINE... TODAY...A SOUTHERLY RETURN FLOW WILL BECOME WELL ESTABLISHED ACROSS THE COASTAL WATERS TODAY AS ATLANTIC HIGH PRESSURE PREVAILS. DESPITE SOME STRONGER WINDS ALOFT...MIXING WILL REMAIN LIMITED OVER THE COOLER NEAR SHORE WATERS THUS WINDS AT THE SURFACE SHOULD NOT EXCEED 10 TO 15 KT. HOWEVER...WINDS OVER THE OUTER GA WATERS AND IN CHARLESTON HARBOR ALONG THE LAND/SEA INTERFACE COULD REACH UPWARDS OF 15 TO 20 KT AT TIMES THIS AFTERNOON. A SOUTHEAST SWELL WILL KEEP SEAS ELEVATED IN THE 3-5 FT RANGE TODAY...WITH A SMALL POTENTIAL FOR SOME 6 FT SEAS TO ENCROACH UPON THE FAR REACHES OF THE OUTER GA WATERS. GIVEN LIMITED CONFIDENCE...HAVE OPTED TO NOT ISSUE A SMALL CRAFT ADVISORY...ALTHOUGH CONDITIONS COULD WARRANT OTHERWISE LATER TODAY. DEW POINTS SURGING INTO THE LOWER 60S WITHIN THE SOUTHERLY FLOW COULD SUPPORT THE DEVELOPMENT OF PATCHY SEA FOG LATER THIS AFTERNOON ACROSS THE NEAR SHORE WATERS. TONIGHT...THE SOUTHERLY FLOW WILL STRENGTHEN TO UPWARDS OF 15 TO 20 KT ACROSS THE COASTAL WATERS AS THE SURFACE PRESSURE GRADIENT TIGHTENS BETWEEN ATLANTIC HIGH PRESSURE AND A COLD FRONT WELL TO THE WEST. A SOUTHEAST SWELL WILL KEEP SEAS SOLIDLY IN THE 3-5 FT RANGE...HIGHEST ACROSS THE OUTER GA WATERS. THERE IS A SMALL POTENTIAL THAT MARGINAL SMALL CRAFT ADVISORY CONDITIONS FOR WINDS AND/OR SEAS COULD OCCUR OVER THE OUTER GA WATERS...BUT NOT ENOUGH CONFIDENCE TO RAISE AN ADVISORY AT THIS TIME. THE POTENTIAL FOR PATCHY SEA FOG WILL PERSIST TONIGHT ACROSS THE NEAR SHORE WATERS AND CHARLESTON HARBOR AS A WARM/MOIST SOUTHERLY FLOW PREVAILS. SATURDAY THROUGH TUESDAY...WIND FIELDS WILL INCREASE SATURDAY INTO SATURDAY NIGHT AS A STRONG COLD FRONT MOVES THROUGH. ON SATURDAY THE FLOW WILL BE OUT OF THE SOUTH AND CONDITIONS SHOULD REMAIN BELOW ADVISORY CRITERIA. BUT ONCE COLD ADVECTION CRANKS UP LATE SATURDAY EVENING AND OVERNIGHT AND GEOSTROPHIC WINDS INCREASE TO 35-40 KT...WE EXPECT SMALL CRAFT ADVISORY CONDITIONS ON MOST IF NOT ALL MARINE ZONES. CONDITIONS WILL QUICKLY IMPROVE ON SUNDAY AS THE HIGH PRESSURE CENTER MOVES CLOSER TO THE WATERS. FAIRLY QUIET WINDS/SEAS ANTICIPATED SUNDAY NIGHT THROUGH MID WEEK AS THE HIGH PRESSURE DOMINATES. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM...BSH SHORT TERM...JRL LONG TERM...JRL AVIATION...BSH MARINE...JAQ/JRL
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1041 AM EDT FRI MAR 28 2014 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL AS WEAK UPPER DISTURBANCES MOVE THROUGH THE AREA TODAY AND TONIGHT. A COLD FRONT WILL CROSS THE REGION SATURDAY AFTERNOON AND EVENING...FOLLOWED BY DRY HIGH PRESSURE THROUGH THURSDAY. A COLD FRONT MAY AFFECT THE AREA NEXT FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATE THIS MORNING...CLOUDS HAVE STEADILY FILLED IN ACROSS THE FORECAST AREA WITH MUCH OF IT BECOMING OVERCAST NOW. THERE ARE STILL SOME BREAKS ON VISIBLE SATELLITE IMAGERY...BUT THESE SHOULD FILL IN THROUGH THE DAY ESPECIALLY AS MID/HIGH CLOUDS STREAM IN FROM ONGOING CONVECTION TO THE WEST. RADAR IMAGERY SHOWS PERIODIC SHOWERS MOVING ONSHORE IN THE SOUTHERLY FLOW...MAINLY AFFECTING CHARLESTON AND BERKELEY COUNTIES THIS MORNING. DIAGNOSING WHAT IS CURRENTLY GOING ON AROUND THE REGION...THERE IS A FAIRLY LARGE COMPLEX OF CONVECTION ONGOING ALONG THE GULF COAST FROM AROUND NEW ORLEANS TO THE WESTERN FLORIDA PANHANDLE. BASED ON REGIONAL RAOB/S THIS CONVECTION APPEARS TO BE ASSOCIATED WITH AN AREA OF ELEVATED INSTABILITY. THIS IS FURTHER SUPPORTED BY NEGATIVE SHOWALTER INDICES FROM THE RAP AND AN AREA OF ENHANCED MID LEVEL LAPSE RATES NOTED FROM THE SPC MESOANALYSIS PAGE. FOR INSTANCE...COMPARING THE 12Z KTLH AND KCHS SHOWS SIMILAR MID LEVEL ENVIRONMENTS OTHER THAN THE PROMINENT SUBSIDENCE INVERSION NOTED IN THE KCHS SOUNDING AT AROUND 650 MB. THIS INVERSION IS SUPPORTED BY INTERROGATING ALL TILTS RADAR OF THE CURRENT SHOWER ACTIVITY...WHICH SHOWS THE DEPTH OF REFLECTIVITY SHUTTING OFF AROUND 11 KFT...WHICH IS NEAR THE 650 MB LEVEL. SO THE BEST MID LEVEL ENVIRONMENT IS CERTAINLY TO OUR WEST AND SOUTHWEST AND BASED ON CURRENT HI-RES MODEL RUNS IT APPEARS THAT WILL CONTINUE THROUGH THE DAY. THE 11Z HRRR APPEARS TO BE HANDLING THE ONGOING CONVECTION THE BEST...AND THROUGH THE DAY IT TAKES THE MOST INTENSE UPSTREAM CONVECTION IN A SOUTHEASTWARD DIRECTION OVER THE FLORIDA PANHANDLE AND THE EASTERN GULF. THIS SEEMS REASONABLE AS THE BEST MID LEVEL ENVIRONMENT AND LATER SURFACE BASED INSTABILITY WILL BE TO THE SOUTH AND SOUTHEAST OF ITS CURRENT LOCATION. SO...FOR THE FORECAST AREA...THE THINKING IS THAT WE WILL CONTINUE TO SEE SHALLOW CONVECTION AT BEST. I HAVE ADJUSTED POPS ACCORDINGLY...AND THE SCHEME FAVORS THE EASTERN AREAS NOW AND THEN THE WESTERN AREAS LATER AS THE DIMINISHING UPSTREAM SHOWERS/CONVECTION ATTEMPT TO PUSH IN. WITH THE CLOUD COVER ONGOING AND EXPECTED...HIGH TEMPERATURES ARE TRICKY. I HAVE LOWERED VALUES MORE INTO THE LOW TO MID 70S...BUT THIS COULD BE ON THE LOW END IF WE GET MORE SUN THAN EXPECTED. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... TONIGHT...ATLANTIC HIGH PRESSURE WILL PREVAIL AS A COLD FRONT APPROACHES FROM THE TENNESSEE VALLEY AND DEEP SOUTH. SOUTHERLY FLOW WILL CONTINUE TO ADVECT DEEP MOISTURE INTO THE REGION. THE COMBINATION OF THE DEEP LAYERED MOISTURE...FORCING FOR ASCENT ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET...AND A POTENT SHORT WAVE PASSING ALOFT WILL SUPPORT SCATTERED TO NUMEROUS SHOWERS ACROSS THE AREA...ESPECIALLY LATE THIS EVENING AND OVERNIGHT. IN ADDITION...INSTABILITY PARAMETERS/MID LEVEL LAPSE RATES ARE SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORMS AS WELL. TEMPERATURES WILL NOT FALL SIGNIFICANTLY GIVEN THE SOUTHERLY FLOW AND CLOUD COVER...WITH LOWS EXPECTED TO BE AROUND 60 IN MOST AREAS. A POTENT UPPER SHORTWAVE WILL MOVE INTO THE CENTRAL APPALACHIANS ON SATURDAY. SOUTHWEST FLOW WILL STRENGTHEN CONSIDERABLY AS THE DAY WEARS ON...WITH 0-6 KM WINDS 40-45 KT BY 00Z SUN. THIS WILL ALSO INCREASE MOISTURE ACROSS THE AREA WITH PWATS ABOVE 1.50 INCHES BY 18Z SAT. A COLD FRONT IS EXPECTED TO SWEEP THROUGH THE AREA SATURDAY EVENING. THERE REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE DEGREE OF BOUNDARY LAYER DESTABILIZATION AHEAD OF THE FRONT. GIVEN THE EXTENSIVE LOW-LEVEL MOISTURE ADVECTING INTO THE REGION DURING THE DAY WE WOULD EXPECT TO HAVE QUITE A BIT OF LOW STRATOCUMULUS IN PLACE. HOWEVER SOME OF THE GUIDANCE IS DEPICTING A WEAK DRY SLOT DURING THE MIDDAY HOURS AFTER A BATCH OF MORNING PRECIP MOVES THROUGH. BOTH THE GFS AND NAM ARE SHOWING 1500 J/KG CAPES WITH LIFTED INDICES BELOW -4C DURING THE AFTERNOON ACROSS SOUTHEAST GA. THIS COINCIDES WITH 40-45 KT OF BULK SHEAR. IT IS ALSO WORTH NOTING THAT THE STORM PREDICTION CENTER STILL SHOWS OUR ENTIRE FORECAST AREA WITHIN THE DAY 2 SLIGHT RISK. WE PLAN TO ADD MENTION OF POSSIBLE SEVERE WEATHER TO THE HAZARDOUS WEATHER OUTLOOK. STRONG LOW-LEVEL WARM ADVECTION AND PRE-FRONTAL COMPRESSION ON SATURDAY WILL PUSH HIGH TEMPS INTO THE UPPER 70S. THIS COULD POTENTIALLY BE TOO COOL IF SOME BREAKS DEVELOP IN THE CLOUDS. CONSIDERABLE COVERAGE OF SHOWERS AND THUNDERSTORMS IS EXPECTED THROUGH SATURDAY EVENING BEFORE PRECIP TAPERS OFF BEHIND THE FRONT. A SLIGHT COOL DOWN IS EXPECTED FOR SUNDAY DUE TO COLD ADVECTION WITH THE HIGH BUILDING IN...HOWEVER DOWNSLOPE FLOW WILL ALLOW TEMPS TO REACH 70 OR THEREABOUTS. A 30-35 KT GEOSTROPHIC WIND FIELD AND DEEP MIXING WILL RESULT IN BREEZY CONDITIONS ESPECIALLY DURING THE HOURS OF PEAK HEATING. DRY WEATHER WITH MODERATING TEMPERATURES EXPECTED ON MONDAY WITH HIGHS REBOUNDING INTO THE LOWER TO MIDDLE 70S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... A BROAD UPPER LEVEL RIDGE WILL PREVAIL MONDAY NIGHT THROUGH THURSDAY WITH DRY HIGH PRESSURE AT THE SURFACE. THIS WILL RESULT IN ABOVE NORMAL TEMPERATURES WITH HIGHS CLIMBING INTO THE UPPER 70S OR LOWER 80S AND LOWS MAINLY IN THE 50S. THE UPPER RIDGE BREAKS DOWN ON FRIDAY WITH A WEAK COLD FRONT POSSIBLY MOVING IN FROM THE WEST. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS SHOULD GENERALLY PREVAIL AT BOTH KCHS AND KSAV THROUGH AT LEAST THIS AFTERNOON. BRIEF/ISOLATED SHOWERS ARE POSSIBLE AROUND KCHS THROUGH MUCH OF THE MORNING...BUT GIVEN LIMITED COVERAGE AND OVERALL LOW CONFIDENCE...THERE WILL BE NO MENTION IN THE KCHS TAF. BREEZY CONDITIONS WILL DEVELOP THIS AFTERNOON WITH GUSTS UPWARDS OF 20 KT AT TIMES. INCREASING LOW LEVEL MOISTURE AND A PASSING UPPER LEVEL DISTURBANCE WILL RESULT IN SCATTERED TO NUMEROUS SHOWERS AND PERHAPS A FEW THUNDERSTORMS LATER THIS AFTERNOON INTO TONIGHT. AS A RESULT...HAVE ADDED VICINITY SHOWERS TO THE TAF/S BEGINNING EARLY THIS AFTERNOON...THEN PREVAILING SHOWERS LATE THIS AFTERNOON THROUGH THIS EVENING. CEILINGS COULD PERIODICALLY LOWER TO MVFR LEVELS LATE THIS AFTERNOON AND THIS EVENING...ESPECIALLY IN SHOWERS. THEN...MVFR CEILINGS WILL BECOME MORE PREVALENT AFTER MIDNIGHT AT BOTH TERMINALS...WITH EVEN A LOW PROBABILITY OF IFR CEILINGS DEVELOPING AT KSAV. EXTENDED AVIATION OUTLOOK...OCCASIONAL FLIGHT RESTRICTIONS POSSIBLE SATURDAY AFTERNOON AND EVENING IN SCATTERED SHOWERS AND THUNDERSTORMS. VFR CONDITIONS EXPECTED THEREAFTER. BREEZY CONDITIONS EXPECTED ON SUNDAY. && .MARINE... TODAY...A SOUTHERLY RETURN FLOW WILL BECOME WELL ESTABLISHED ACROSS THE COASTAL WATERS TODAY AS ATLANTIC HIGH PRESSURE PREVAILS. DESPITE SOME STRONGER WINDS ALOFT...MIXING WILL REMAIN LIMITED OVER THE COOLER NEAR SHORE WATERS THUS WINDS AT THE SURFACE SHOULD NOT EXCEED 10 TO 15 KT. HOWEVER...WINDS OVER THE OUTER GA WATERS AND IN CHARLESTON HARBOR ALONG THE LAND/SEA INTERFACE COULD REACH UPWARDS OF 15 TO 20 KT AT TIMES THIS AFTERNOON. A SOUTHEAST SWELL WILL KEEP SEAS ELEVATED IN THE 3-5 FT RANGE TODAY...WITH A SMALL POTENTIAL FOR SOME 6 FT SEAS TO ENCROACH UPON THE FAR REACHES OF THE OUTER GA WATERS. GIVEN LIMITED CONFIDENCE...HAVE OPTED TO NOT ISSUE A SMALL CRAFT ADVISORY...ALTHOUGH CONDITIONS COULD WARRANT OTHERWISE LATER TODAY. DEW POINTS SURGING INTO THE LOWER 60S WITHIN THE SOUTHERLY FLOW COULD SUPPORT THE DEVELOPMENT OF PATCHY SEA FOG LATER THIS AFTERNOON ACROSS THE NEAR SHORE WATERS. TONIGHT...THE SOUTHERLY FLOW WILL STRENGTHEN TO UPWARDS OF 15 TO 20 KT ACROSS THE COASTAL WATERS AS THE SURFACE PRESSURE GRADIENT TIGHTENS BETWEEN ATLANTIC HIGH PRESSURE AND A COLD FRONT WELL TO THE WEST. A SOUTHEAST SWELL WILL KEEP SEAS SOLIDLY IN THE 3-5 FT RANGE...HIGHEST ACROSS THE OUTER GA WATERS. THERE IS A SMALL POTENTIAL THAT MARGINAL SMALL CRAFT ADVISORY CONDITIONS FOR WINDS AND/OR SEAS COULD OCCUR OVER THE OUTER GA WATERS...BUT NOT ENOUGH CONFIDENCE TO RAISE AN ADVISORY AT THIS TIME. THE POTENTIAL FOR PATCHY SEA FOG WILL PERSIST TONIGHT ACROSS THE NEAR SHORE WATERS AND CHARLESTON HARBOR AS A WARM/MOIST SOUTHERLY FLOW PREVAILS. SATURDAY THROUGH TUESDAY...WIND FIELDS WILL INCREASE SATURDAY INTO SATURDAY NIGHT AS A STRONG COLD FRONT MOVES THROUGH. ON SATURDAY THE FLOW WILL BE OUT OF THE SOUTH AND CONDITIONS SHOULD REMAIN BELOW ADVISORY CRITERIA. BUT ONCE COLD ADVECTION CRANKS UP LATE SATURDAY EVENING AND OVERNIGHT AND GEOSTROPHIC WINDS INCREASE TO 35-40 KT...WE EXPECT SMALL CRAFT ADVISORY CONDITIONS ON MOST IF NOT ALL MARINE ZONES. CONDITIONS WILL QUICKLY IMPROVE ON SUNDAY AS THE HIGH PRESSURE CENTER MOVES CLOSER TO THE WATERS. FAIRLY QUIET WINDS/SEAS ANTICIPATED SUNDAY NIGHT THROUGH MID WEEK AS THE HIGH PRESSURE DOMINATES. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM...BSH SHORT TERM...JRL LONG TERM...JRL AVIATION...JAQ/JRL MARINE...JAQ/JRL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1040 AM EDT FRI MAR 28 2014 .UPDATE... HAVE MADE SIGNIFICANT ADJUSTMENTS TO THE FORECAST TO ACCOUNT FOR LATEST THINKING WITH TODAYS WEATHER. AXIS OF PRECIPITATION IS FURTHER SOUTH THAN ORIGINALLY ANTICIPATED...AND PREVIOUS FORECAST POP AND WX GRIDS DID NOT MATCH THIS POSITIONING. OVERALL...MODEL GUIDANCE WITH THIS SYSTEM IS POOR...WITH VERY FEW DEPICTING THE CURRENT RADAR TRENDS WELL. HAVE OVERALL GONE WITH THE HRRR WHICH SEEMS TO HAVE A BETTER HANDLE ON THE CURRENT CONDITIONS. THE HRRR DOES SUGGEST MUCH OF THE COMPLEX IN MS/AL WILL ORGANIZE INTO THIS AFTERNOON...BECOMING MORE LINEAR IN NATURE...AND PUSHING ACROSS SOUTHWEST GEORGIA. ALTHOUGH THERE IS A QUESTION OF WHETHER THIS LINEAR CONVECTION WILL MATERIALIZE...THE HRRR CONTINUES TO SHOW MUCH OF NORTH GEORGIA CUT OFF FROM GULF MOISTURE...AND LIMITS THE AMOUNT OF PRECIP OVER THE NORTHERN SECTIONS OF THE CWA. AS A RESULT...HAVE CONTINUED THE TREND OF HIGHEST POPS ACROSS CENTRAL GEORGIA INTO THE OVERNIGHT PERIOD. WILL CONTINUE TO UPDATE THE GRIDS AS NECESSARY...ESPECIALLY THE NEXT 24 HOURS. 31 .PREV DISCUSSION... /ISSUED 717 AM EDT FRI MAR 28 2014/ PREV DISCUSSION... /ISSUED 341 AM EDT FRI MAR 28 2014/ SHORT TERM /TODAY THROUGH SATURDAY/... SURFACE ANALYSIS SHOWS A COLD FRONT STRETCHING FROM THE CENTRAL GREAT LAKES BACK THROUGH THE ARKLATEX. A LARGE AREA OF PRECIPITATION HAS DEVELOPED TO THE EAST OF THE BOUNDARY AN IS MOVING INTO NW PORTIONS OF THE CWFA. PRECIP WILL CONTINUE TO INCREASE FOR MUCH OF THE AREA TODAY AS THE FRONT SLOWLY PUSHES EASTWARD. THE NORTHERN END OF THE FRONT WILL MAKE SOME EASTWARD PROGRESS TODAY...WHILE THE SOUTHERN END WILL LAG UNTIL EARLY SATURDAY MORNING. A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE SOUTHERN TAIL OF THE FRONT TONIGHT...AND FINALLY HELP PUSH THE FRONT THROUGH THE CWFA ON SATURDAY. THE NORTHERN END OF THE FRONT WILL BECOME TEMPORARILY STATIONARY NEAR THE TN/GA BORDER THIS EVENING AND OVERNIGHT. EXPECT SHOWERS AND A FEW THUNDERSTORMS TO TRAIN ACROSS THE NORTHERN HALF OF THE CWFA...IN THE VICINITY OF THE BOUNDARY TONIGHT. MODELS SHOWING A BIT MORE INSTABILITY ACROSS THE SOUTHERN CWFA FOR THIS AFTERNOON THAN IN PREVIOUS RUNS. STILL...ONLY A COUPLE HUNDRED JULES OF CAPE. WILL KEEP THUNDER CHANCES AT A MINIMUM TODAY AND ONLY MENTION A SLIGHT CHANCE. EVEN THOUGH A BREAK IN THE WIDESPREAD PRECIPITATION IS EXPECTED THIS EVENING...THE CHANCES FOR THUNDER WILL SLIGHTLY INCREASE AS A MID LEVEL SHORTWAVE TRAVERSES THE AREA AND STEEPENS LAPSE RATES. STILL...SURFACE INSTABILITY WILL BE LIMITED...SO WILL CAP THE THUNDER WORDING AT A CHANCE. A BIT MORE INSTABILITY WILL BE PRESENT SATURDAY AFTERNOON...ESPECIALLY ACROSS THE SOUTHEAST PORTION OF THE CWFA. THIS AREA HAS THE POTENTIAL FOR SOME HEATING...WITH TEMPS IN THE LOWER TO MIDDLE 70S. SURFACE BASED CAPES SHOULD RANGE FROM 500 TO 1000 J/KG. THE BEST SHEAR SHOULD LAG...ALONG WITH THE FRONTAL BOUNDARY. HOWEVER...WILL NOT RULE OUT STRONG THUNDERSTORMS WITH ISOLATED SEVERE STORMS POSSIBLE. DAMAGING WIND GUSTS SHOULD BE THE PRIMARY MODE OF SEVERE WEATHER. NLISTEMAA LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... FOR THE MOST PART...SYSTEM THAT BRINGS RAIN TO THE AREA IN THE SHORT TERM SHOULD HAVE EXITED THE AREA BY THE BEGINNING OF THE LONG TERM. THE EXCEPTION TO THIS IS ACROSS FAR NORTHEAST GEORGIA AND THE FAR SOUTHEAST PART OF THE CWA WHERE SOME RAIN COULD LINGER THROUGH SATURDAY NIGHT. AT THIS POINT...IT APPEARS THE PRECIPITATION SHOULD END ACROSS THE NE GA MOUNTAINS BEFORE THE COOLER TEMPERATURES MOVE IN. AFTER THIS HIGH PRESSURE WILL DOMINATE THROUGH ABOUT MID WEEK. BOTH THE GFS AND THE ECMWF SUGGEST THE NEXT SYSTEM MOVING THROUGH IN THE LATER HALF OF THE WEEK. INSTABILITY VALUES SUPPORT THE MENTION OF THUNDER IN THE FORECAST THURSDAY INTO FRIDAY. 11 HYDROLOGY... ONE CONCERN FOR THE FORECAST PERIOD IS LOCALLY HEAVY RAINFALL. PWATS JUST UNDER AN INCH AND HALF WILL BE LIKELY THIS AFTERNOON THROUGH SATURDAY. THESE NUMBERS ARE VERY CLOSE TO BEING 2SD ABOVE NORMAL FOR THIS TIME OF YEAR. 6HR FFG GUIDANCE RANGES FROM AROUND 2 TO 3 INCHES ACROSS THE CWFA. STORM TOTAL PRECIP FROM TODAY THROUGH SATURDAY NIGHT AVERAGES AN INCH AND A HALF TO JUST ABOUT TWO AND THREE QUARTERS OF AN INCH. SINCE THE RAINFALL IS EXPECTED TO BE OVER A LONGER PERIOD OF TIME...FF ISN`T A MAJOR CONCERN AT THIS TIME. HOWEVER...WHERE THUNDERSTORMS REPEATEDLY TRAIN...SOME LOCALIZED FF IS POSSIBLE. DO EXPECT SOME RISES ON THE RIVERS BUT NOT CONFIDENT ENOUGH TO SAY IF RIVERS WILL GO INTO FLOOD YET. NLISTEMAA AVIATION... 12Z UPDATE... RAIN HAS STARTED TO OVERSPREAD THE METRO AREA THIS MORNING AHEAD OF A COLD FRONT ACROSS THE ARKLATEX. A BREAK IN THE PRECIP IS EXPECTED THIS EVENING...BUT PRECIP WILL FILL IN AGAIN EARLY FRIDAY AS THE COLD FRONT MOVES THROUGH. MODELS ARE PROGGING IFR CIGS WITH THE WIDESPREAD RAIN TODAY...AND THINK THAT IS REASONABLE. CIGS MAY END UP LOWER THAN FORECAST OVERNIGHT...BUT FOR NOW WILL KEEP LOWEST VALUES AROUND 500FT. WINDS WILL REMAIN OUT OF THE SE. //ATL CONFIDENCE...12Z UPDATE... MEDIUM CONFIDENCE ON IFR CIGS. HIGH CONFIDENCE REMAINING ELEMENTS. && .PRELIMINARY POINT TEMPS/POPS... ATHENS 64 55 69 40 / 100 80 70 10 ATLANTA 63 57 66 41 / 100 70 70 5 BLAIRSVILLE 56 52 60 35 / 100 80 60 20 CARTERSVILLE 62 57 65 40 / 100 80 70 5 COLUMBUS 67 60 72 45 / 100 50 60 5 GAINESVILLE 59 54 64 39 / 100 80 70 5 MACON 69 59 73 42 / 90 50 60 10 ROME 62 57 64 40 / 100 80 70 5 PEACHTREE CITY 64 57 68 38 / 100 70 70 5 VIDALIA 76 61 75 47 / 60 40 70 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...31 LONG TERM....BAKER AVIATION...31
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
756 AM EDT FRI MAR 28 2014 .SYNOPSIS... MOISTURE WILL BE HIGH AHEAD OF A SLOW MOVING FRONTAL SYSTEM. THE FRONT WILL MOVE THROUGH THE FORECAST AREA LATE SATURDAY. HIGH PRESSURE AND DRIER CONDITIONS WILL PREVAIL SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... TODAY...A MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SHOULD HELP SUPPORT SHOWERS TODAY. THE NAM AND GFS MOS PLUS RADAR TRENDS SUPPORT HIGH POPS. BASED TIMING ON RADAR TRENDS AND THE LATEST HRRR. CLOUDINESS AND SHOWERS SHOULD LIMIT INSTABILITY. THE NAM INDICATES JUST WEAK INSTABILITY. THE HRRR AND SATELLITE TRENDS SUPPORT KEEPING THE STRONGER CONVECTION SOUTH OF THE FORECAST AREA. EXPECT MAINLY SHOWERS INSTEAD OF THUNDERSTORMS. USED THE COOLER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS. TONIGHT...THE MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SUPPORT CONTINUED HIGH POPS TONIGHT. COVERAGE MAY INCREASE TOWARD MORNING AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. COOLING ALOFT ASSOCIATED WITH THE UPPER TROUGH SUPPORTS A HIGHER CHANCE OF THUNDERSTORMS TOWARD MORNING. SHEAR WILL BE ON THE INCREASE INDICATING WELL- ORGANIZED THUNDERSTORMS MAY OCCUR BUT THE NAM SUGGESTS ANY SURFACE-BASED INSTABILITY WILL REMAIN WEAK THROUGH THE NIGHT. THE DIURNAL TIMING SHOULD ALSO HELP LIMIT INSTABILITY. THEREFORE...THE RISK OF SEVERE THUNDERSTORMS APPEARS LOW AT THIS TIME. THE WARMER TEMPERATURE GUIDANCE APPEARS BETTER BECAUSE OF CLOUDINESS. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... SATURDAY...MOISTURE SHOULD BE HIGH AHEAD OF THE COLD FRONT SATURDAY. THE NAM INDICATES THE DEEPEST MOISTURE EARLY SATURDAY. THE GFS AND ECMWF SHOW THE DEEPEST MOISTURE AROUND THE MIDDLE OF THE DAY AHEAD OF THE COLD FRONT. THE MODELS WERE MORE CONSISTENT WITH COLD FRONTAL PASSAGE LATE IN THE DAY OR EVENING. WE MAINTAINED LIKELY POPS DURING MUCH OF THE DAY WITH THE TIMING DIFFICULT BECAUSE ISENTROPIC LIFT APPEARS GREATER IN THE MORNING...BUT CONVERGENCE AHEAD OF THE COLD FRONT SHOULD BE HIGHER DURING THE AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE H85 WINDS OF 35 TO 40 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S NEAR -3 DURING THE AFTERNOON. THERE WILL BE A THREAT OF SEVERE THUNDERSTORMS BECAUSE OF THIS SHEAR AND INSTABILITY. ANY LINGERING SHOWERS AND THUNDERSTORMS SHOULD END FROM WEST TO EAST SATURDAY EVENING AS DRYING BECOMES DOMINATE BEHIND THE COLD FRONT. WE USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .LONG TERM /SUNDAY THROUGH THURSDAY/... THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE IN THE PERIOD AHEAD OF A COLD FRONT. THE COOLEST NIGHT SHOULD BE SUNDAY NIGHT. STRONG NOCTURNAL COOLING SHOULD OCCUR WITH DRY HIGH PRESSURE OVERHEAD AND LIGHT WINDS. AN AVERAGE OF THE GFS...ECMWF AND EKD MOS SUPPORTS LOWS MAINLY IN THE UPPER 30S. FROST WILL BE POSSIBLE MAINLY IN THE NORMALLY COLDER LOCATIONS. WARMER TEMPERATURES SHOULD OCCUR BEGINNING MONDAY AS THE HIGH SHIFTS EASTWARD AND THE AIR MASS CONTINUES TO MODIFY. THE GFS...ECMWF... AND EKD MOS SUPPORT HIGHS IN THE UPPER 70S TO AROUND 80 TUESDAY THROUGH THURSDAY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... REGIONAL RADAR LOOP SHOWS AN AREA OF SHOWERS IN THE UPSTATE AND SHOWERS AND A FEW THUNDERSTORMS EXTENDING SOUTHWESTWARD THROUGH GEORGIA. SHOULD SEE AT LEAST SCATTERED SHOWERS REACHING THE TAF SITES BY MIDDAY...BUT BETTER CHANCE DURING THE AFTERNOON INTO THE EVENING HOURS. CURRENT OBSERVATIONS SHOW MAINLY VFR CONDITIONS IN THE UPSTATE WHICH INCREASES CONFIDENCE THAT TAF SITES MAY REMAIN VFR THROUGH MUCH OF THE MORNING. LAMP GUIDANCE INDICATES CONDITIONS DETERIORATING TO MVFR EARLY THIS AFTERNOON AND REMAINING MVFR OR IFR THROUGH THE END OF THE TAF PERIOD...WHILE NAM INDICATES A PERIOD OF CIGS ABOVE 3000 FEET DURING THE EARLY AFTERNOON HOURS. WILL LEAN A BIT MORE TOWARDS THE MORE PESSIMISTIC LAMP FORECAST. LATEST CAE VWP SHOWING 40 KT WIND AROUND 2 KFT EARLY THIS MORNING...WITH LIGHT WINDS AT THE SURFACE. WILL MENTION LLWS FOR ALL TAF SITES UNTIL AROUND 15Z THIS MORNING. EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS EXPECTED SATURDAY AHEAD OF A COLD FRONT THAT WILL CROSS THE AREA LATE SATURDAY AFTERNOON. BREEZY CONDITIONS IN THE WAKE OF THE FRONT SATURDAY NIGHT INTO SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
641 AM EDT FRI MAR 28 2014 .SYNOPSIS... MOISTURE WILL BE HIGH AHEAD OF A SLOW MOVING FRONTAL SYSTEM. THE FRONT WILL MOVE THROUGH THE FORECAST AREA LATE SATURDAY. HIGH PRESSURE AND DRIER CONDITIONS WILL PREVAIL SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... TODAY...A MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SHOULD HELP SUPPORT SHOWERS TODAY. THE NAM AND GFS MOS PLUS RADAR TRENDS SUPPORT HIGH POPS. BASED TIMING ON RADAR TRENDS AND THE LATEST HRRR. CLOUDINESS AND SHOWERS SHOULD LIMIT INSTABILITY. THE NAM INDICATES JUST WEAK INSTABILITY. THE HRRR AND SATELLITE TRENDS SUPPORT KEEPING THE STRONGER CONVECTION SOUTH OF THE FORECAST AREA. EXPECT MAINLY SHOWERS INSTEAD OF THUNDERSTORMS. USED THE COOLER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS. TONIGHT...THE MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SUPPORT CONTINUED HIGH POPS TONIGHT. COVERAGE MAY INCREASE TOWARD MORNING AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. COOLING ALOFT ASSOCIATED WITH THE UPPER TROUGH SUPPORTS A HIGHER CHANCE OF THUNDERSTORMS TOWARD MORNING. SHEAR WILL BE ON THE INCREASE INDICATING WELL- ORGANIZED THUNDERSTORMS MAY OCCUR BUT THE NAM SUGGESTS ANY SURFACE-BASED INSTABILITY WILL REMAIN WEAK THROUGH THE NIGHT. THE DIURNAL TIMING SHOULD ALSO HELP LIMIT INSTABILITY. THEREFORE...THE RISK OF SEVERE THUNDERSTORMS APPEARS LOW AT THIS TIME. THE WARMER TEMPERATURE GUIDANCE APPEARS BETTER BECAUSE OF CLOUDINESS. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... SATURDAY...MOISTURE SHOULD BE HIGH AHEAD OF THE COLD FRONT SATURDAY. THE NAM INDICATES THE DEEPEST MOISTURE EARLY SATURDAY. THE GFS AND ECMWF SHOW THE DEEPEST MOISTURE AROUND THE MIDDLE OF THE DAY AHEAD OF THE COLD FRONT. THE MODELS WERE MORE CONSISTENT WITH COLD FRONTAL PASSAGE LATE IN THE DAY OR EVENING. WE MAINTAINED LIKELY POPS DURING MUCH OF THE DAY WITH THE TIMING DIFFICULT BECAUSE ISENTROPIC LIFT APPEARS GREATER IN THE MORNING...BUT CONVERGENCE AHEAD OF THE COLD FRONT SHOULD BE HIGHER DURING THE AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE H85 WINDS OF 35 TO 40 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S NEAR -3 DURING THE AFTERNOON. THERE WILL BE A THREAT OF SEVERE THUNDERSTORMS BECAUSE OF THIS SHEAR AND INSTABILITY. ANY LINGERING SHOWERS AND THUNDERSTORMS SHOULD END FROM WEST TO EAST SATURDAY EVENING AS DRYING BECOMES DOMINATE BEHIND THE COLD FRONT. WE USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .LONG TERM /SUNDAY THROUGH THURSDAY/... THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE IN THE PERIOD AHEAD OF A COLD FRONT. THE COOLEST NIGHT SHOULD BE SUNDAY NIGHT. STRONG NOCTURNAL COOLING SHOULD OCCUR WITH DRY HIGH PRESSURE OVERHEAD AND LIGHT WINDS. AN AVERAGE OF THE GFS...ECMWF AND EKD MOS SUPPORTS LOWS MAINLY IN THE UPPER 30S. FROST WILL BE POSSIBLE MAINLY IN THE NORMALLY COLDER LOCATIONS. WARMER TEMPERATURES SHOULD OCCUR BEGINNING MONDAY AS THE HIGH SHIFTS EASTWARD AND THE AIR MASS CONTINUES TO MODIFY. THE GFS...ECMWF... AND EKD MOS SUPPORT HIGHS IN THE UPPER 70S TO AROUND 80 TUESDAY THROUGH THURSDAY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS LOW-LEVEL MOISTURE INCREASES...MODEL GUIDANCE SUGGESTING MVFR CIGS DEVELOPING EARLY THIS MORNING. THERE IS THE POSSIBILITY OF IFR CEILINGS AROUND SUNRISE...BUT CONFIDENCE TOO LOW TO INCLUDE. SHOULD SEE AT LEAST SCATTERED SHOWERS DEVELOPING BY MIDDAY...BUT BETTER CHANCE DURING THE AFTERNOON INTO THE EVENING HOURS. LAMP GUIDANCE INDICATE MVFR CIGS CONTINUING THROUGH THE END OF THE TAF PERIOD...WHILE NAM INDICATES A PERIOD OF CIGS ABOVE 3000 FEET DURING THE AFTERNOON HOURS. WILL LEAN A BIT MORE TOWARDS THE MORE PESSIMISTIC LAMP FORECAST. LATEST CAE VWP SHOWING 40 KT WIND AROUND 2 KFT EARLY THIS MORNING...WITH LIGHT WINDS AT THE SURFACE. WILL MENTION LLWS FOR ALL TAF SITES UNTIL AROUND 15Z THIS MORNING. EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS EXPECTED FRIDAY NIGHT INTO SATURDAY AHEAD OF COLD FRONT THAT WILL CROSS THE AREA LATE SATURDAY AFTERNOON. BREEZY CONDITIONS IN THE WAKE OF THE FRONT SATURDAY NIGHT INTO SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
346 AM EDT FRI MAR 28 2014 .SYNOPSIS... MOISTURE WILL BE HIGH AHEAD OF A SLOW MOVING FRONTAL SYSTEM. THE FRONT WILL MOVE THROUGH THE FORECAST AREA LATE SATURDAY. HIGH PRESSURE AND DRIER CONDITIONS WILL PREVAIL SUNDAY AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... TODAY...A MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SHOULD HELP SUPPORT SHOWERS TODAY. THE NAM AND GFS MOS PLUS RADAR TRENDS SUPPORT HIGH POPS. BASED TIMING ON RADAR TRENDS AND THE LATEST HRRR. CLOUDINESS AND SHOWERS SHOULD LIMIT INSTABILITY. THE NAM INDICATES JUST WEAK INSTABILITY. THE HRRR AND SATELLITE TRENDS SUPPORT KEEPING THE STRONGER CONVECTION SOUTH OF THE FORECAST AREA. EXPECT MAINLY SHOWERS INSTEAD OF THUNDERSTORMS. USED THE COOLER TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS. TONIGHT...THE MOIST SOUTHERLY FLOW AND ISENTROPIC LIFT SUPPORT CONTINUED HIGH POPS TONIGHT. COVERAGE MAY INCREASE TOWARD MORNING AHEAD OF A MID-LEVEL SHORTWAVE TROUGH. COOLING ALOFT ASSOCIATED WITH THE UPPER TROUGH SUPPORTS A HIGHER CHANCE OF THUNDERSTORMS TOWARD MORNING. SHEAR WILL BE ON THE INCREASE INDICATING WELL- ORGANIZED THUNDERSTORMS MAY OCCUR BUT THE NAM SUGGESTS ANY SURFACE-BASED INSTABILITY WILL REMAIN WEAK THROUGH THE NIGHT. THE DIURNAL TIMING SHOULD ALSO HELP LIMIT INSTABILITY. THEREFORE...THE RISK OF SEVERE THUNDERSTORMS APPEARS LOW AT THIS TIME. THE WARMER TEMPERATURE GUIDANCE APPEARS BETTER BECAUSE OF CLOUDINESS. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... SATURDAY...MOISTURE SHOULD BE HIGH AHEAD OF THE COLD FRONT SATURDAY. THE NAM INDICATES THE DEEPEST MOISTURE EARLY SATURDAY. THE GFS AND ECMWF SHOW THE DEEPEST MOISTURE AROUND THE MIDDLE OF THE DAY AHEAD OF THE COLD FRONT. THE MODELS WERE MORE CONSISTENT WITH COLD FRONTAL PASSAGE LATE IN THE DAY OR EVENING. WE MAINTAINED LIKELY POPS DURING MUCH OF THE DAY WITH THE TIMING DIFFICULT BECAUSE ISENTROPIC LIFT APPEARS GREATER IN THE MORNING...BUT CONVERGENCE AHEAD OF THE COLD FRONT SHOULD BE HIGHER DURING THE AFTERNOON. SHEAR WILL BE HIGH. THE MODELS INDICATE H85 WINDS OF 35 TO 40 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S NEAR -3 DURING THE AFTERNOON. THERE WILL BE A THREAT OF SEVERE THUNDERSTORMS BECAUSE OF THIS SHEAR AND INSTABILITY. ANY LINGERING SHOWERS AND THUNDERSTORMS SHOULD END FROM WEST TO EAST SATURDAY EVENING AS DRYING BECOMES DOMINATE BEHIND THE COLD FRONT. WE USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .LONG TERM /SUNDAY THROUGH THURSDAY/... THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE IN THE PERIOD AHEAD OF A COLD FRONT. THE COOLEST NIGHT SHOULD BE SUNDAY NIGHT. STRONG NOCTURNAL COOLING SHOULD OCCUR WITH DRY HIGH PRESSURE OVERHEAD AND LIGHT WINDS. AN AVERAGE OF THE GFS...ECMWF AND EKD MOS SUPPORTS LOWS MAINLY IN THE UPPER 30S. FROST WILL BE POSSIBLE MAINLY IN THE NORMALLY COLDER LOCATIONS. WARMER TEMPERATURES SHOULD OCCUR BEGINNING MONDAY AS THE HIGH SHIFTS EASTWARD AND THE AIR MASS CONTINUES TO MODIFY. THE GFS...ECMWF... AND EKD MOS SUPPORT HIGHS IN THE UPPER 70S TO AROUND 80 TUESDAY THROUGH THURSDAY. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS FORECAST FOR THE NEXT SEVERAL HOURS. AS LOW-LEVEL MOISTURE INCREASES LATE TONIGHT...LAMP GUIDANCE AND MAV/MET MOS SUGGESTING MVFR CIGS DEVELOPING DURING THE PRE-DAWN HOURS. THERE IS THE POSSIBILITY OF IFR CEILINGS AROUND SUNRISE...BUT CONFIDENCE TOO LOW TO INCLUDE. SHOULD SEE AT LEAST SCATTERED SHOWERS DEVELOPING BY MIDDAY...BUT BETTER CHANCE DURING THE AFTERNOON INTO THE EVENING HOURS. LAMP GUIDANCE INDICATE MVFR CIGS CONTINUING THROUGH THE END OF THE TAF PERIOD...WHILE NAM INDICATES A PERIOD OF CIGS ABOVE 3000 FEET DURING THE AFTERNOON HOURS. WILL LEAN A BIT MORE TOWARDS THE MORE PESSIMISTIC LAMP FORECAST. INCREASING SOUTHERLY LOW LEVEL JET OVERNIGHT. LATEST CAE VWP SHOWING 40-45 KT WIND AROUND 2 KFT EARLY THIS MORNING. WILL MENTION LLWS FOR ALL TAF SITES UNTIL AROUND 15Z THIS MORNING. EXTENDED AVIATION OUTLOOK...CIG/VSBY RESTRICTIONS EXPECTED FRIDAY NIGHT INTO SATURDAY AHEAD OF COLD FRONT THAT WILL CROSS THE AREA LATE SATURDAY AFTERNOON. BREEZY CONDITIONS IN THE WAKE OF THE FRONT SATURDAY NIGHT INTO SUNDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
954 PM CDT SAT MAR 29 2014 .DISCUSSION... 321 PM CDT MAIN FORECAST CONCERNS/CHALLENGES ARE WITH SHOWER/THUNDER CHANCES MONDAY AND MONDAY NIGHT...AND THEN WITH ACTIVE WEATHER TO CONTINUE THROUGH LATE IN THE WORK WEEK. CHALLENGES IN THE NEAR TERM HAVE BEEN WITH THE LINGERING AND SLOW MOVING LOW STRATUS STILL IN PLACE OVER MUCH OF THE CWA...AS WELL AS RESULTANT HIGH TEMPERATURES. LATEST VISIBLE SATELLITE IMAGERY DEPICTING A SLOW SOUTH/SOUTHEAST MOVEMENT TO THE STRATUS BUT WITH SOME PROGRESS BEING MADE. ALTHOUGH...THIS PROGRESS IS SLOW AND COINCIDING WITH FURTHER DIURNAL DEVELOPMENT ON THE NORTHERN PERIPHERY OF THIS CLOUD DECK. MADE EDITS THIS AFTERNOON TO SLOW THE CLEARING TREND THROUGH 00Z AND WITH AT LEAST PARTLY CLOUDY SKIES FOR THE SOUTHERN THIRD OF THE CWA THROUGH EARLY THIS EVENING...BEFORE CLEARING CONTINUES AND MOSTLY CLEAR SKIES EXPECTED TO PREVAIL OVERNIGHT. DID DROP HIGH TEMPS A COUPLE OF DEGREES IN SOME PLACES EARLIER THIS AFTERNOON DUE TO THIS CLOUD COVER...WITH TEMPS STAYING IN THE UPPER 30S OR AROUND 40 UNDER THE CLOUD COVER AND LOW TO MID 40S FOR AREAS WHICH HAVE OBSERVED MORE SUNSHINE WITHIN THE LAST COUPLE OF HOURS. ALTHOUGH...ALL LOCATIONS WILL OBSERVE FALLING TEMPS THIS EVENING AS THE DEPARTING CLOUD COVER THIS AFTERNOON AND EVENING ONLY AIDS IN A COLD NIGHT TONIGHT. SURFACE HIGH TO THE WEST/NORTHWEST WILL SHIFT OVERHEAD TONIGHT WITH WINDS DIMINISHING AND DESPITE WAA BEGINNING OVERNIGHT...TEMPS ANTICIPATED TO FALL INTO THE 20S ACROSS THE CWA. MID/UPPER 20S ARE LIKELY FOR MOST LOCATIONS...OUTSIDE OF THE CITY...WITH SOME LOCATIONS POSSIBLE DIPPING INTO THE LOWER 20S. QUIET CONDITIONS EXPECTED SUNDAY/SUNDAY NIGHT AS UPPER LEVEL RIDGING IS ONGOING ACROSS THE REGION. CONTINUED WAA WILL HELP A WARMER AIRMASS TO SPREAD OVER THE CWA ON SUNDAY WITH TEMPS EXPECTED TO RISE AROUND 60. DID MAKE SOME MINOR ADJUSTMENTS TO MAX TEMPS MAINLY TO ACCOUNT FOR PERSISTENT ONSHORE FLOW FOR AREAS IN CHICAGO AND NORTHWARD...KEEPING TEMPS IN THE LOW TO MID 50S. AFTER A MILD NIGHT SUNDAY NIGHT...PERSISTENT WAA WILL PROVIDE WELL ABOVE NORMAL HIGHS IN THE MID TO UPPER 60S. ONSHORE FLOW NOT ANTICIPATED SO MOST LOCATIONS LIKELY TO OBSERVE THIS WARMTH. WILL HAVE INCREASING CLOUD COVER ON MONDAY IN ADVANCE OF VORT MAX AND ATTENDANT SURFACE LOW MOVING EAST OVER THE CENTRAL CONUS. GUIDANCE IN AGREEMENT WITH DRY CONDITIONS MONDAY MORNING AND THEN WITH INCREASING CHANCES FOR PRECIP INTO THE AFTERNOON...THOUGH PRIMARILY FOR THE WESTERN CWA. FOR MONDAY AFTERNOON INTO MONDAY EVENING...NOT OVERLY CONFIDENT WITH POPS DURING THIS PERIOD AND HAVE ONLY MADE MINOR CHANGES TO LOW CHANCE/CHANCE POPS. THIS IS MAINLY DUE TO THE FACT THAT CONFIDENCE IS NOT HIGH WITH REGARDS TO OVERALL COVERAGE OF PRECIP. WITH LARGE SCALE FORCING FOR ASCENT SPREADING OVER THE AREA ON MONDAY AS WELL AS MOISTURE INCREASING OUT AHEAD OF SURFACE LOW AND COLD FRONT...DEVELOPMENT SHOULD NOT BE TOO MUCH OF AN ISSUE...AND EXPECT POPS TO LIKELY CHANGE DURING THIS PERIOD WITH SUCCESSIVE FORECASTS. STILL NOT OVERLY CONFIDENT WITH THUNDER DEVELOPMENT AS WELL...AND SO HAVE MADE LITTLE CHANGES DURING THIS TIME KEEPING CHANCE THUNDER IN THE GRIDS. WILL NEED TO MONITOR THE EXTENT OF THE MOISTURE RETURN AND RESULTANT INSTABILITY...WHICH AT THIS TIME IS APPEARING RATHER WEAK. WILL STILL NEED TO MONITOR AN EXPECTED ACTIVE WEATHER PATTERN FOR THIS NEXT WEEK AS GUIDANCE IS IN AGREEMENT WITH SEVERAL FEATURES PUSHING ACROSS THE REGION. ALTHOUGH...TIMING AND EVOLUTION AGREEMENT IS LACKING WHICH WILL BE KEY WITH PRECIP TYPE...WHICH COULD STILL BE OF FROZEN FORM VERY LATE IN THE FORECAST PERIOD. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * SOUTH SOUTHEAST WINDS SUNDAY INCREASING TO OVER 10 KT. //DISCUSSION...UPDATED 00Z... A HIGH PRESSURE RIDGE CENTERED ACROSS THE MISSISSIPPI RIVER LATE THIS AFTERNOON WILL MOVE OVER AREA TAF SITES BY MID EVE AND PERSIST THROUGH DAYBREAK SUNDAY. DIMINISHING WIND SPEEDS AND A CLEARING SKY WILL BE THE RESULT. THERE WILL BE POTENTIAL FOR FOG DEVELOPMENT PRIMARILY IN THOSE AREAS THAT CLEARED THE LATEST TODAY DUE TO ELEVATED DEW POINTS AND SLIGHTLY COOLER TEMPS. THE MOST VULNERABLE AIRPORT WILL THUS BE GYY AND HAVE INCLUDED MENTION OVERNIGHT...THOUGH TEMPORARY IFR FOG WOULD CONCEIVABLY BE POSSIBLE. SUNDAY WILL SEE SOUTHEAST WINDS BECOMING NEAR DUE SOUTH BY AFTERNOON AND INCREASING IN SPEED WITH SPORADIC GUSTS IN THE AFTERNOON ACROSS NORTH CENTRAL AND POSSIBLY NORTHEAST IL. A LAKE BREEZE IS LIKELY TO DEVELOP OVER CHICAGO BUT WHETHER IT CAN REACH FAR ENOUGH WEST AS MDW AND ORD WILL BE CLOSE. HAVE OPTED TO NOT INDICATE A WIND SHIFT AT THOSE TWO AIRPORTS...WHILE LEANING WITH PREVAILING WINDS JUST EAST OF SOUTH...THOUGH WOULD NOT BE SURPRISED TO SEE THEM VARY BETWEEN 160 AND 190 IN THE AFTERNOON. //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH IN WINDS THROUGH SUNDAY MORNING. MEDIUM THEREAFTER...AS DIRECTION COULD BRIEFLY CHANGE TO EAST SOUTHEAST SUNDAY AFTERNOON WITH A LAKE BREEZE. //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...NEAR DUE SOUTH WINDS GUSTING TO AROUND 30 KT IN THE AFTERNOON. CHC OF TSRA DURING THE EVE AND A SLGT CHC OF LIGHT RAIN/SNOW DURING THE OVERNIGHT. TUESDAY...MORNING MVFR POSSIBLE. WEDNESDAY...EAST FLOW WITH RAIN AND MVFR/IFR LIKELY. THURSDAY...EAST FLOW WITH CHC OF RAIN AND POSSIBLE IFR. FRIDAY...CHC OF RAIN DURING THE DAY. SLGT CHC OF RAIN/SNOW DURING THE NIGHT. MTF && .MARINE... 251 PM CDT NORTH-NORTHEASTERLY ONSHORE FLOW ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA CONTINUES UP AROUND 20S OUT AHEAD OF AN AREA OF HIGH PRESSURE. THIS FLOW IS BIT STRONGER THAN PREVIOUSLY THOUGH...AND AS A CONSEQUENCE OF THIS...I HAVE ISSUED A SMALL CRAFT ADVISORY THROUGH THIS EVENING...MAINLY FOR THE EXPECTATION THAT WAVES ARE AT OR JUST ABOVE THE 4 FOOT MARK. THESE WINDS WILL ABATE THIS EVENING...THEN GRADUALLY BECOME EAST-SOUTHEASTERLY OVERNIGHT TONIGHT AS THE SURFACE RIDGE SHIFTS OVER THE LAKE. LOW PRESSURE WILL BE IN THE PROCESS OF DEVELOPING ACROSS THE CENTRAL HIGH PLAINS ON SUNDAY...AND THIS WILL RESULT IN A CONTINUAL SOUTH-SOUTHEASTERLY FLOW PATTERN ACROSS THE LAKE FOR THE NEXT COUPLE OF DAYS. THE LOW IS EXPECTED TO TRACK EAST-NORTHEASTERLY TO THE UPPER MISSISSIPPI VALLEY BY LATE MONDAY EVENING...THEN SHIFT ACROSS THE UPPER GREAT LAKES BY TUESDAY EVENING. OVERALL...THIS WILL RESULT IN INCREASING SOUTHERLY WINDS MONDAY AND INTO MONDAY EVENING...LIKELY TO AROUND 30 KT. OVERALL...IT APPEARS THAT WARMER AIR MOVING OVER THE LAKE WILL RESULT IN A STABLE MARINE LAYER...WHICH WOULD RESULT IN LOWER CHANCES FOR GALES. HOWEVER...SOME STRONGER WINDS NEARLY GALE FORCE ARE POSSIBLE WITH THIS SYSTEM...ESPECIALLY MONDAY NIGHT AS THE LOW AND COLD FRONT APPROACH THE LAKE. WESTERLY FLOW WILL SET UP TUESDAY IN THE WAKE OF THIS SYSTEM. ANOTHER STORM SYSTEM LOOKS TO TAKE AIM ON THE LOWER GREAT LAKES LATER IN THE PERIOD...AROUND THURSDAY. THIS COULD RESULT IN A PERIOD OF SOME ENHANCED NORTHEASTERLY WINDS INTO THE END OF THE UP COMING WEEK. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM SATURDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
  [top] Area Forecast Discussion National Weather Service Lincoln IL 822 PM CDT Sat Mar 29 2014 .DISCUSSION... ISSUED 822 PM CDT Sat Mar 29 2014 Have made adjustments to sky grids to push clearing a bit faster than current package. Otherwise going forecast looks good. Surface ridge moving into forecast area attm and winds have decoupled despite significant northwest winds above the boundary layer associated with strengthening system over the central Appalachians. This flow above developing inversion continues to erode cloud cover and advect drier air into Illinois from northwest to southeast. Trapped moisture under the inversion may lead to some patchy ground fog. Attm, it appears that lowest vsbys should be around 3SM so will leave out of grids/zones but keep it in eastern TAF sites. Latest Lamp guidance in good agreement with ongoing forecast for tonight`s lows. Barker && .AVIATION... ISSUED 604 PM CDT Sat Mar 29 2014 MVFR CIGs eroding slowly from northwest to southeast as ridge west of the Mississippi River builds into Illinois. At 23z only KBMI and KCMI retain a CIG and satellite imagery suggests KBMI should clear shortly. Improvement at KCMI may be a bit slower. Pilot report from 2225z suggests stratus remains near 1500 ft thick and with sun setting, rate of thinning may slow. Will hold on to MVFR CIG there til 03z. Also given the slow clearing and ridge moving overhead, could see the redevelopment of ground fog, particularly at KCMI given the NAM Bufr sounding. For now will keep mention of BR out of I-55 terminals and KPIA where sfc dewpoints have been able to fall slightly with this afternoon`s advection from the north. However, will need to throw in a tempo for MVFR fog for late tonight at KDEC and KCMI. Ridge pushes east on Sunday and models suggest some higher CIGs developing during the afternoon once the mid-level ridge inflection point moves east of the terminals ahead of a developing system over the central high plains. Since the CIGs should be above operational significant heights will not break off a new grouping attm. With ridge pushing east, south winds develop on Sunday and gusty conditions should return. particularly at western terminals. Barker && .PREV DISCUSSION... ISSUED 228 PM CDT Sat Mar 29 2014 The progressive weather pattern will provide active weather next week as several storm systems affect Illinois. The latter half of this weekend looks pleasant with plenty of sunshine pushing temps above normal. However, by Monday afternoon the first system will bring chances of rain, and the onset of a return to cooler conditions. Heavier rains in the Wed to Thur time frame could accumulate between 1-2" in some locations. Localized flooding may develop. SHORT TERM...Tonight through Sunday night. Low clouds have been keeping high temps generally below forecast highs this afternoon. A narrow break in the cloud cover allowed Peoria to spike up about 10 degrees in a couple hours, and create a large temperature gradient over short distances in our forecast area. The RAP and HRRR layer RH indicate that some clearing should continue west of I-57 between 23z and 03z. Lows tonight will be dependent on cloud cover. Areas east of I-57 may remain cloudy until just after midnight as NE surface winds continue to drag low- level moisture from the Great Lakes into eastern IL. Even a few hours of clearing later tonight should allow eastern areas to cool off to near guidance lows, especially with surface dewpoints dipping into the upper 20s in many locations. Sunday will see mid level temps climb 5 to 7C during the day as an upper level ridge axis advances into eastern IL by 00z/7pm Monday. Near full sunshine should combine with increasing south winds to push highs about 10 to 15 deg above normal (60s), which will be a welcome taste of Spring. An tightening pressure gradient ahead of the next system will keep south winds up in the 10 to 20 mph range even Sunday night. So despite clear skies Sunday night, south winds will keep a mixed boundary layer and allow lows to be in the upper 40s west and around 40 east. LONG TERM...Monday through Saturday. Increasing clouds on Monday will not prohibit highs from climbing well into the 60s for one more day, as south-southeast winds increase into the 25 to 35 mph range. By Monday afternoon, a parent low pressure system will advance from eastern Nebraska to southeastern Minn, as a cold front reaches the western border of IL by 00z/7pm Monday. Pre-frontal storms will have a high amount of wind shear and storm relative helicity available, along with steep lapse rates, but a limited amount of moisture. Forecast soundings show the best instability may be at or above 750 mb, so any thunderstorms will be elevated to begin. Due the strong jet dynamics and wind shear with this system, some of the storms could begin rotating and produce hail and strong winds Monday afternoon and evening ahead of the cold front. Showers and storms should end from west to east by midnight in the post-frontal subsidence and dry air intrusion. Clouds will likely clear out behind the line of precip, so lows in the NW could dip below freezing, while southeast areas remain in the low 40s. The brief pocket of cold air is forecast to brush across N IL late Mon night and Tues morning, which will keep highs about 10-15 deg colder than Monday. High temps will range from around 50 near Galesburg to around 60 by Lawrenceville. Return flow behind the cooler high pressure will bring increasing moisture Tuesday night, with a few showers possible before sunrise on Wednesday. Thunderstorm chances will increase along and south of a warm front that is expected to develop directly across central IL from west to east. Storm chances will be higher in the warm sector roughly south of a line from Rushville to Champaign. Instability may have a better chance of being based closer to the surface as dewpoints climb into the 50s Wed night south of the warm front, which will be close to overnight low temps. Precipitable water values are expected to climb over an inch Wed night through Thursday as low pressure tracks northeast along the warm front. Locally heavy rain may occur in any thunderstorms, with training of storms over the same area also boosting rainfall amounts. Localized flooding could develop in low areas, as rainfall amounts possibly reach between 1 and 2 inches by Thursday afternoon. A wide range of temps will occur across C IL from north to south from Tues night through Thursday as the warm front lingers across the middle of the area. The temp spreads could be 20 to 25 degrees from north to south for highs and lows. There is a spread of solutions for how the surface and upper level systems progress from after Thursday. The GFS lingers the upper trough farther west Thurs night, then brings a secondary surface low and another round of rain showers across IL on Friday. The ECMWF is more progressive and drys out the air column after the low on Thursday. So low chance and slight chance PoPs were included Thurs night and Friday to account for a slower progression. There is some agreement that another push of cold air will keep temps below normal for Friday and Saturday, with Saturday looking dry at this time. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1253 PM CDT FRI MAR 28 2014 .DISCUSSION... 1018 AM CDT HAVE MADE SOME ADJUSTMENTS TO SKY GRIDS TODAY TO BE A BIT LESS OPTIMISTIC WITH CLEARING. LOW LEVEL MOISTURE/STRATUS IS CURRENTLY TRAPPED UNDER A FAIRLY SHARP INVERSION AND INVERSION IS LIKELY TO PERSIST NOT OFFERING MUCH HOPE FOR BETTER MIXING. CLEARING LINE OVER CENTRAL WISCONSIN IS MAKING FAIRLY QUICK PROGRESS SOUTHWARD AND WILL PROBABLY MAKE IT INTO AT LEAST OUR NORTHERN CWA THIS AFTERNOON...THOUGH WITH LOW LEVEL FLOW SLACKENING THIS AFTERNOON AND VEERING NE WOULD EXPECT THIS CLEARING LINE TO SLOW DOWN A BIT. ASSUMING CLOUD COVER LINGERS INTO THE AFTERNOON...TEMPERATURES WILL BE SLOW TO RECOVER AND HAVE SHAVED A FEW DEGREES OFF GOING HIGH TEMPS. UPDATED GRIDS/TEXT PRODUCTS HAVE BEEN SENT. IZZI //PREV DISCUSSION... 323 AM CDT TODAY... SURFACE COLD FRONT IS CLEARING THE EASTERN COUNTIES IN THE CWA EARLY THIS MORNING WHILE A SECONDARY TROUGH IS DIGGING ACROSS NORTHERN ILLINOIS WITH WINDS TURNING SHARPLY TO THE NNW WITH GUSTS WELL INTO THE 20 KT RANGE. SHOWERS BEHIND THIS TROUGH WILL SWEEP ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...EXITING TO THE EAST BY MID TO LATE MORNING. BREEZY CONDITIONS THIS MORNING SHOULD GRADUALLY TAPER THROUGH THE DAY AS THE AS THE LOW LIFTS TOWARDS QUEBEC AND FILLS. TEMPS INTO THE MID TO UPPER 40S ARE EXPECTED THIS AFTERNOON...BUT A LAKE BREEZE WILL TURN WINDS NORTHEASTERLY AND COOL TEMPS BACK INTO THE 30S ALONG THE LAKE. THIS WEEKEND... LOW PRESSURE WILL LIFT FROM ARKLATEX INTO THE UPPER OHIO VALLEY BY MIDDAY SATURDAY. BEST CHANCES FOR PRECIP WILL BE SOUTH OF I-80 ESPECIALLY IN NORTHWEST INDIANA...AND FOR NOW IT APPEARS AREAS NORTH WILL REMAIN DRY. GFS INDICATES WET BULBS DROPPING BELOW ZERO THROUGH THE COLUMN AROUND OR BEFORE THE ONSET OF PRECIP INDICATE ALL SNOW. NAM SOUNDINGS ON THE OTHER HAND SHOW SLIGHTLY WARMER TEMPS ALOFT HINTING AT THE POSSIBILITY FOR RAIN/SNOW MIX...THOUGH SREF P-TYPE PROBABILITY INDICATES BETTER CHANCES FOR SNOW. COMING OFF HIGHS IN THE UPPER 40S IN AREAS MOST LIKELY TO SEE PRECIP...AND OVERNIGHT LOWS SOUTH OF 80 AT OR EVEN SLIGHTLY ABOVE FREEZING...THE LIKELIHOOD OF ACCUMULATING SNOW IS LOW AND WOULD LIKELY BE CONFINED TO THE GRASS. IN ADDITION...GIVEN THE MARGINAL SOUNDINGS...SNOW PRODUCTION WOULD BE INEFFICIENT. WILL MAINTAIN RAIN/SNOW MIX IN THE FORECAST FOR NOW GIVEN THE CURRENT UNCERTAINTY. HIGH PRESSURE WILL THEN TRANSLATE ACROSS THE REGION OVER THE REMAINDER OF THE WEEKEND RESULTING IN DRY WEATHER FROM SATURDAY AFTERNOON ON. H85 THERMAL TROUGH WILL APPROACH THE REGION ON SATURDAY...THOUGH SUBSIDENCE ALOFT SETTLING OVER THE UPPER MIDWEST THROUGH THE DAY SATURDAY WILL RESULT IN DRYING AND WARMING OF THE MID LEVELS WHICH WILL HELP MODULATE THE COLDER AIRMASS MOVING OVERHEAD. WITH AFTERNOON SUNSHINE...EXPECT AREAS AWAY FROM THE LAKE TO RISE INTO THE MID TO UPPER 40S AGAIN...WITH A FEW 50S MAINLY SOUTH OF I-80. ALONG THE LAKE FRONT...A BREEZE OFF THE LAKE THROUGH THE DAY WILL KEEP TEMPERATURES MUCH COOLER...IN THE MID 30S. THE SURFACE RIDGE AXIS WILL PASS OVERHEAD SATURDAY NIGHT...AND SOUTHERLY FLOW WILL RAMP UP THROUGH THE DAY SUNDAY AHEAD OF OUR NEXT AREA OF LOW PRESSURE STARTING TO TAKE SHAPE OVER THE PLAINS. STRONG WARM ADVECTION IS EXPECTED THROUGH THE DAY SUNDAY WHICH WILL RESULT IN H85 TEMPS RISING TO AROUND 10C BY SUNDAY EVENING. SOUTHERLY WINDS MAY TAKE ON A SLIGHT WESTERLY COMPONENT BY SUNDAY AFTERNOON...IN THE 190-200 DIRECTION...WHICH WITH THE INCREASING WINDS SHOULD HELP STAVE OFF ANY LAKE BREEZE/LAKE COOLING SUNDAY. NAM/GFS SOUNDINGS SHOW LOW TO MID 20 KT GUSTS POSSIBLE BY SUNDAY AFTERNOON. TEMPERATURES SHOULD RISE TO AROUND 60 RIGHT UP TO THE LAKE FRONT SUNDAY AFTERNOON. MONDAY... AFOREMENTIONED SURFACE LOW PROGGED TO LIFT FROM THE MID MISSOURI VALLEY EARLY MONDAY INTO MN/WI MONDAY EVENING. LATEST GUIDANCE IN DECENT AGREEMENT ON THE LOCAL AREA GETTING FULL WARM SECTOR ON MONDAY. LEANED TOWARD WARMER SIDE OF GUIDANCE MONDAY WITH A BLEND OF BIAS CORRECTED GEM AND ECMWF. THIS RESULTS IN LOW TO MID 60S AREA WIDE MONDAY AFTERNOON...AND WITH A MODERATE-STRONG SSW WIND...DO NOT ANTICIPATE ANY COOLING ALONG THE LAKE. A 60-70KT LOW LEVEL JET FOCUSES STRONG CONVERGENCE ACROSS THE MID MISSOURI VALLEY SUNDAY NIGHT...THEN AT 40-50 KT REFOCUSES TO OUR NORTH MONDAY EVENING/NIGHT. ACROSS NORTHERN ILLINOIS IN THE WARM SECTOR... INSTABILITY IS PRETTY MEAGER WITH A STRONG CAP IN PLACE...THOUGH SOME DYNAMIC COOLING ASSOCIATED WITH NEGATIVELY TILTED H5 WAVE AND EXIT REGION OF UPPER JET MAY RESULT IN SOME SCATTERED CONVECTION. ALL-IN-ALL THOUGH...GIVEN THE UNFAVORABLE TIMING OF THE FRONT OVERNIGHT...NOT TOO IMPRESSED WITH PRECIP CHANCES MONDAY AND TRIMMED POPS FOR THIS PERIOD. TUESDAY THROUGH THURSDAY... PRETTY LOW CONFIDENCE IN THE DETAILS AT THIS POINT...BUT TUESDAY THROUGH THURSDAY SHOULD BE AN ACTIVE PERIOD WITH A SERIES OF DISTURBANCES MOVING ACROSS THE REGION. THERE REMAINS SIGNIFICANT DIFFERENCES AT THIS POINT BETWEEN MODELS WITH RESPECT TO THE LOW TRACK WHICH WILL DETERMINE TEMPS AND PRECIP TYPE. GFS INDICATES A FASTER MORE SOUTHERLY LOW WHILE THE ECMWF HINTS AT A WARMER SOLUTION WITH A DEEPER LOW THAT TRACKS FARTHER NORTH. FOR NOW...STAYED CLOSE TO A CONSENSUS BLEND. TUBELESS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * VARIABLE NORTH-NORTHWEST TO NORTH-NORTHEAST WINDS...TURNING NORTHEAST MID/LATE AFTERNOON. * CIGS AROUND 020 SCATTERING LATE THIS AFTERNOON OR EARLY THIS EVENING. * ANOTHER PERIOD OF LOWER CIGS POSSIBLE LATE TONIGHT/SATURDAY MORNING...MVFR POSSIBLE. MDB //DISCUSSION...UPDATED 18Z... LOW PRESSURE CONTINUES TO MOVE NORTHEAST ACROSS EASTERN ONTARIO AND WESTERN QUEBEC LEAVING NORTHERLY WINDS IN ITS WAKE ACROSS THE LOCAL AREA. WINDS WILL LIKELY BE VARIABLE BETWEEN NORTHWEST AND NORTH INLAND OF THE LAKE THROUGH THE AFTERNOON THEN TURN LIGHT NORTHEASTERLY THIS EVENING. AREAS CLOSER TO THE LAKE INCLUDING ORD/MDW/GYY WILL LIKELY FLUCTUATE BETWEEN NORTHWEST AND NORTH- NORTHEAST WITH GYY BECOMING STEADY NORTHEAST EARLY THIS AFTERNOON. NOT AS CONFIDENCE IN IF STEADIER NORTHEAST WINDS WILL SET UP AT ORD/MDW DURING THE AFTERNOON OT HOLD OFF UNTIL EVENING. CLOUD COVER REMAINS ABUNDANT...WHICH MAY ALSO SLOW THE TIMING OF A SHIFT TO NORTHEAST WINDS/LAKE BREEZE. WITH THE SOUTHWARD ADVANCE OF CLEARING ACROSS SOUTHERN WISCONSIN SLOWING WILL KEEP MVFR CIGS ACROSS THE TERMINALS THROUGH THE AFTERNOON THEN SCATTER/CLEAR EARLY THIS EVENING. AN UPPER TROUGH CROSSES THE AREA LATER TONIGHT BRINGING LOWERING CIGS. CIGS SHOULD REMAIN LOWER END MVFR BUT A PERIOD OF MVFR IS POSSIBLE. THERE IS ALSO A MINIMAL THREAT FOR SOME LIGHT SNOW OR JUST FLURRIES OVERNIGHT BUT WILL KEEP THE TAF DRY. NORTHEAST WINDS WILL PERSIST THROUGH SATURDAY WITH SKIES SCATTERING/CLEARING DURING THE MID/LATE MORNING HOURS. MDB //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM CONFIDENCE IN WIND TRENDS...LOW-MEDIUM CONFIDENCE IN TIMING OF SHIFT TO STEADIER NORTHEAST. * HIGH CONFIDENCE IN MVFR CIGS THROUGH MID AFTERNOON...THEN LOW- MEDIUM CONFIDENCE IN TIMING OF SCATTERING BEYOND THAT. * MEDIUM CONFIDENCE THAT CIGS WILL REMAIN VFR OVERNIGHT/SATURDAY MORNING. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. NORTHEAST WINDS TURNING SOUTHEAST. SUNDAY...VFR. SOUTH WINDS. MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS. TUESDAY...VFR PROBABLE. WEST WINDS. WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS. THURSDAY...CHANCE OF RAIN OR SNOW AND IFR/MVFR. NORTHEAST WINDS. LENNING && .MARINE... 307 AM CDT A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE...AS THE LOW MOVES THROUGH. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1231 PM CDT Fri Mar 28 2014 .DISCUSSION... ISSUED 1014 AM CDT Fri Mar 28 2014 Updated forecast to lower highs a few degrees and increase cloud cover mainly across central/northern CWA. 10 AM visible satellite imagery showed a strip of clearing north of the Ohio River extending into the far SE CWA, while farther north a thick blanket of stratus/SC stretched back through most of MO/IA and southern WI. HRRR and RAP RH trends in the 950-900 MB level suggest the clearing over the far SE will slowly shift north towards I-72 by late afternoon as southerly winds strengthen in that layer. This clearing will be brief however as mid clouds ahead of next wave developing in the Plains overspread the region later this afternoon and evening. Brisk NW winds this morning to ease through afternoon as low pressure pushes east of the Great Lakes and MSLP gradient relaxes. && .AVIATION... ISSUED 1231 PM CDT Fri Mar 28 2014 Extensive area of MVFR SC blankets all terminals this afternoon. Latest model trends show this will take until late afternoon and early evening to erode from the south and have shifted TAFS towards that timing. The next weather disturbance will quickly shift northeast from the Plains this evening spreading mid level clouds across the area. All models (except NAM being farthest north outlier) bring precip as far north as the I-72 corridor after midnight through 10-12Z. Thermal profiles are near rain/snow threshold and with surface temps above freezing have -RASN in forecast with slight visibility reduction. Questionable if farthest north sites will receive any precip so have VCSH for BMI and kept PIA dry. Ceilings are expected to be near MVFR during this precip event. Initially light north winds this afternoon will veer around to the northeast and increase in speed overnight through Sat morning up to 10-15 kts in response to low pressure tracking south of the Ohio Valley. 25 && .PREV DISCUSSION... ISSUED 313 AM CDT Fri Mar 28 2014 SHORT TERM...Today through Sunday Main forecast challenge in the immediate short-term will be timing the departure of low clouds today. 07z/2am surface analysis shows low pressure over southern Lake Michigan with cold front trailing southward along the I-57 corridor. Extensive area of wrap-around cloud cover is noted on IR satellite imagery blanketing Iowa, northern Missouri, and western Illinois. With low-level flow becoming northwesterly, these clouds will spill across central Illinois early this morning. All model guidance suggests an overcast start to the day, but how quickly the clouds clear out remains in question. NAM forecast soundings indicate clouds will mix out/dissipate between 15z and 18z. Latest HRRR hints at this as well, although the process may be slower than the NAM advertises. Given subsidence behind departing upper short-wave and late March sun working on the low clouds, think skies will temporarily clear around midday into the early afternoon. After that, high clouds will quickly begin to increase ahead of the next approaching system by mid to late afternoon. Next forecast concern revolves around low pressure expected to track from Texas into the Tennessee River Valley tonight. Models have been having difficulty resolving how far north associated precip will spread. 00z Mar 28 suite is still in disagreement, with the GFS being the most aggressive in bringing precip furthest north. Since GFS is often too bullish with light QPF events and airmass will be drying today, think the NAM has a more realistic handle on the situation. As such, will keep locations along and north of a Jacksonville to Bloomington line dry tonight. Best rain chances will be focused along/south of I-70 in closer proximity to the low track, with POPs steadily decreasing further northwest. Despite overnight lows in the middle to upper 30s, NAM forecast soundings remain warm enough for rain. If colder/further north GFS verifies, a rain/snow mix may be possible along the northern fringe of the precip area. Will leave mention of mix out of the forecast due to skepticism about the GFS QPF field. After a few lingering showers across the far E/SE KILX CWA Saturday morning, dry and warmer weather will be the rule this weekend. As southerly winds develop, high temperatures will climb into the lower to middle 60s by Sunday. LONG TERM...Monday through Thursday Models are still advertising cold frontal passage late Monday, although amount of available moisture appears to be quite limited. GFS surface dewpoints are initially around 40 degrees Monday morning and only climb to the upper 40s to near 50 by late afternoon. Despite decent upper dynamics associated with vigorous short-wave, lack of deep moisture return from the Gulf will limit convective potential. As a result, will only carry low chance for showers on Monday. Slightly cooler and drier weather will settle into the region behind the departing front on Tuesday before another system comes into the picture by mid-week. There are still some key timing differences with this feature: however, all models agree that it will have much more moisture to work with. With short-wave crossing the Rockies into the central CONUS, surface low pressure is expected to track from eastern Colorado on Tuesday to the southern Great Lakes by Thursday night. Initial surge of WAA clouds/precip will arrive Tuesday night into Wednesday: however, with central Illinois remaining in the cool sector, very little thunder is expected. Once warm front lifts northward into the area and low pressure approaches from the southwest, showers and thunderstorms will become more prevalent Wednesday night into Thursday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1018 AM CDT FRI MAR 28 2014 .DISCUSSION... 1018 AM CDT HAVE MADE SOME ADJUSTMENTS TO SKY GRIDS TODAY TO BE A BIT LESS OPTIMISTIC WITH CLEARING. LOW LEVEL MOISTURE/STRATUS IS CURRENTLY TRAPPED UNDER A FAIRLY SHARP INVERSION AND INVERSION IS LIKELY TO PERSIST NOT OFFERING MUCH HOPE FOR BETTER MIXING. CLEARING LINE OVER CENTRAL WISCONSIN IS MAKING FAIRLY QUICK PROGRESS SOUTHWARD AND WILL PROBABLY MAKE IT INTO AT LEAST OUR NORTHERN CWA THIS AFTERNOON...THOUGH WITH LOW LEVEL FLOW SLACKENING THIS AFTERNOON AND VEERING NE WOULD EXPECT THIS CLEARING LINE TO SLOW DOWN A BIT. ASSUMING CLOUD COVER LINGERS INTO THE AFTERNOON...TEMPERATURES WILL BE SLOW TO RECOVER AND HAVE SHAVED A FEW DEGREES OFF GOING HIGH TEMPS. UPDATED GRIDS/TEXT PRODUCTS HAVE BEEN SENT. IZZI && .PREV DISCUSSION... 323 AM CDT TODAY... SURFACE COLD FRONT IS CLEARING THE EASTERN COUNTIES IN THE CWA EARLY THIS MORNING WHILE A SECONDARY TROUGH IS DIGGING ACROSS NORTHERN ILLINOIS WITH WINDS TURNING SHARPLY TO THE NNW WITH GUSTS WELL INTO THE 20 KT RANGE. SHOWERS BEHIND THIS TROUGH WILL SWEEP ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...EXITING TO THE EAST BY MID TO LATE MORNING. BREEZY CONDITIONS THIS MORNING SHOULD GRADUALLY TAPER THROUGH THE DAY AS THE AS THE LOW LIFTS TOWARDS QUEBEC AND FILLS. TEMPS INTO THE MID TO UPPER 40S ARE EXPECTED THIS AFTERNOON...BUT A LAKE BREEZE WILL TURN WINDS NORTHEASTERLY AND COOL TEMPS BACK INTO THE 30S ALONG THE LAKE. THIS WEEKEND... LOW PRESSURE WILL LIFT FROM ARKLATEX INTO THE UPPER OHIO VALLEY BY MIDDAY SATURDAY. BEST CHANCES FOR PRECIP WILL BE SOUTH OF I-80 ESPECIALLY IN NORTHWEST INDIANA...AND FOR NOW IT APPEARS AREAS NORTH WILL REMAIN DRY. GFS INDICATES WET BULBS DROPPING BELOW ZERO THROUGH THE COLUMN AROUND OR BEFORE THE ONSET OF PRECIP INDICATE ALL SNOW. NAM SOUNDINGS ON THE OTHER HAND SHOW SLIGHTLY WARMER TEMPS ALOFT HINTING AT THE POSSIBILITY FOR RAIN/SNOW MIX...THOUGH SREF P-TYPE PROBABILITY INDICATES BETTER CHANCES FOR SNOW. COMING OFF HIGHS IN THE UPPER 40S IN AREAS MOST LIKELY TO SEE PRECIP...AND OVERNIGHT LOWS SOUTH OF 80 AT OR EVEN SLIGHTLY ABOVE FREEZING...THE LIKELIHOOD OF ACCUMULATING SNOW IS LOW AND WOULD LIKELY BE CONFINED TO THE GRASS. IN ADDITION...GIVEN THE MARGINAL SOUNDINGS...SNOW PRODUCTION WOULD BE INEFFICIENT. WILL MAINTAIN RAIN/SNOW MIX IN THE FORECAST FOR NOW GIVEN THE CURRENT UNCERTAINTY. HIGH PRESSURE WILL THEN TRANSLATE ACROSS THE REGION OVER THE REMAINDER OF THE WEEKEND RESULTING IN DRY WEATHER FROM SATURDAY AFTERNOON ON. H85 THERMAL TROUGH WILL APPROACH THE REGION ON SATURDAY...THOUGH SUBSIDENCE ALOFT SETTLING OVER THE UPPER MIDWEST THROUGH THE DAY SATURDAY WILL RESULT IN DRYING AND WARMING OF THE MID LEVELS WHICH WILL HELP MODULATE THE COLDER AIRMASS MOVING OVERHEAD. WITH AFTERNOON SUNSHINE...EXPECT AREAS AWAY FROM THE LAKE TO RISE INTO THE MID TO UPPER 40S AGAIN...WITH A FEW 50S MAINLY SOUTH OF I-80. ALONG THE LAKE FRONT...A BREEZE OFF THE LAKE THROUGH THE DAY WILL KEEP TEMPERATURES MUCH COOLER...IN THE MID 30S. THE SURFACE RIDGE AXIS WILL PASS OVERHEAD SATURDAY NIGHT...AND SOUTHERLY FLOW WILL RAMP UP THROUGH THE DAY SUNDAY AHEAD OF OUR NEXT AREA OF LOW PRESSURE STARTING TO TAKE SHAPE OVER THE PLAINS. STRONG WARM ADVECTION IS EXPECTED THROUGH THE DAY SUNDAY WHICH WILL RESULT IN H85 TEMPS RISING TO AROUND 10C BY SUNDAY EVENING. SOUTHERLY WINDS MAY TAKE ON A SLIGHT WESTERLY COMPONENT BY SUNDAY AFTERNOON...IN THE 190-200 DIRECTION...WHICH WITH THE INCREASING WINDS SHOULD HELP STAVE OFF ANY LAKE BREEZE/LAKE COOLING SUNDAY. NAM/GFS SOUNDINGS SHOW LOW TO MID 20 KT GUSTS POSSIBLE BY SUNDAY AFTERNOON. TEMPERATURES SHOULD RISE TO AROUND 60 RIGHT UP TO THE LAKE FRONT SUNDAY AFTERNOON. MONDAY... AFOREMENTIONED SURFACE LOW PROGGED TO LIFT FROM THE MID MISSOURI VALLEY EARLY MONDAY INTO MN/WI MONDAY EVENING. LATEST GUIDANCE IN DECENT AGREEMENT ON THE LOCAL AREA GETTING FULL WARM SECTOR ON MONDAY. LEANED TOWARD WARMER SIDE OF GUIDANCE MONDAY WITH A BLEND OF BIAS CORRECTED GEM AND ECMWF. THIS RESULTS IN LOW TO MID 60S AREA WIDE MONDAY AFTERNOON...AND WITH A MODERATE-STRONG SSW WIND...DO NOT ANTICIPATE ANY COOLING ALONG THE LAKE. A 60-70KT LOW LEVEL JET FOCUSES STRONG CONVERGENCE ACROSS THE MID MISSOURI VALLEY SUNDAY NIGHT...THEN AT 40-50 KT REFOCUSES TO OUR NORTH MONDAY EVENING/NIGHT. ACROSS NORTHERN ILLINOIS IN THE WARM SECTOR... INSTABILITY IS PRETTY MEAGER WITH A STRONG CAP IN PLACE...THOUGH SOME DYNAMIC COOLING ASSOCIATED WITH NEGATIVELY TILTED H5 WAVE AND EXIT REGION OF UPPER JET MAY RESULT IN SOME SCATTERED CONVECTION. ALL-IN-ALL THOUGH...GIVEN THE UNFAVORABLE TIMING OF THE FRONT OVERNIGHT...NOT TOO IMPRESSED WITH PRECIP CHANCES MONDAY AND TRIMMED POPS FOR THIS PERIOD. TUESDAY THROUGH THURSDAY... PRETTY LOW CONFIDENCE IN THE DETAILS AT THIS POINT...BUT TUESDAY THROUGH THURSDAY SHOULD BE AN ACTIVE PERIOD WITH A SERIES OF DISTURBANCES MOVING ACROSS THE REGION. THERE REMAINS SIGNIFICANT DIFFERENCES AT THIS POINT BETWEEN MODELS WITH RESPECT TO THE LOW TRACK WHICH WILL DETERMINE TEMPS AND PRECIP TYPE. GFS INDICATES A FASTER MORE SOUTHERLY LOW WHILE THE ECMWF HINTS AT A WARMER SOLUTION WITH A DEEPER LOW THAT TRACKS FARTHER NORTH. FOR NOW...STAYED CLOSE TO A CONSENSUS BLEND. TUBELESS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * NORTHWEST WINDS TURNING NORTH TOWARD MIDDAY AND NORTHEAST THIS AFTERNOON. * MVFR CIGS AROUND 015 GRADUALLY LIFTING TOWARD 020-025 INTO THE AFTERNOON. MDB //DISCUSSION...UPDATED 14Z... PRECIP HAS CLEARED THE TERMINALS LEAVING AN EXPANSIVE AREA OF MVFR CLOUD COVER IN THE 012-020 RANGE WHICH WILL LIKELY CONTINUE INTO THE AFTERNOON...THOUGH MAY SEE SCATTERING DEVELOP ON ITS FRINGES INTO MIDDAY. OTHERWISE NORTHWEST WINDS WILL TURN NORTHERLY INTO MIDDAY THEN NORTHEAST THIS AFTERNOON. MDB FROM 12Z... RAIN SHOWERS WITH POCKETS OF IFR WRAPPING AROUND THE BACK SIDE OF A DEPARTING LOW WILL CLEAR THE AREA BY MID MORNING. WINDS HAVE TURNED NORTHWEST AND WILL CONTINUE TO VEER AROUND TO NORTHEAST BY THE AFTERNOON. NOT CERTAIN ABOUT TIMING OF CHANGE OVER TO AN EASTERLY COMPONENT BUT BEST ESTIMATE IS AROUND NOON OR SHORTLY AFTER. LINGERING MVFR CIGS LATE THIS MORNING WILL EVENTUALLY SCATTER OUT TO VFR THIS AFTERNOON. LENNING //ORD AND MDW CONFIDENCE...UPDATED 14Z... * HIGH CONFIDENCE IN WIND TRENDS...MEDIUM CONFIDENCE IN TIMING OF DIRECTION CHANGES. * HIGH CONFIDENCE IN MVFR CIGS THROUGH EARLY AFTERNOON...WITH MEDIUM CONFIDENCE IN HOW LONG THEY CONTINUE THROUGH THE AFTERNOON. MDB //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. NORTHEAST WINDS TURNING SOUTHEAST. SUNDAY...VFR. SOUTH WINDS. MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS. TUESDAY...VFR PROBABLE. WEST WINDS. WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS. THURSDAY...CHANCE OF RAIN OR SNOW AND IFR/MVFR. NORTHEAST WINDS. LENNING && .MARINE... 307 AM CDT A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE...AS THE LOW MOVES THROUGH. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1014 AM CDT Fri Mar 28 2014 .DISCUSSION... ISSUED 1014 AM CDT Fri Mar 28 2014 Updated forecast to lower highs a few degrees and increase cloud cover mainly across central/northern CWA. 10 AM visible satellite imagery showed a strip of clearing north of the Ohio River extending into the far SE CWA, while farther north a thick blanket of stratus/SC stretched back through most of MO/IA and southern WI. HRRR and RAP RH trends in the 950-900 MB level suggest the clearing over the far SE will slowly shift north towards I-72 by late afternoon as southerly winds strengthen in that layer. This clearing will be brief however as mid clouds ahead of next wave developing in the Plains overspread the region later this afternoon and evening. Brisk NW winds this morning to ease through afternoon as low pressure pushes east of the Great Lakes and MSLP gradient relaxes. 25 && .AVIATION... ISSUED 646 AM CDT Fri Mar 28 2014 MVFR cigs will continue this morning. Big question is how long will these clouds last. This time of year, clouds at this level usually burn off rather quickly. However, area is in good cyclonic flow will lots of clouds/low level moisture across most of MO, all of Iowa and up into WI. So, think that these clouds will last longer than normal. So have the MVFR cigs continuing until around 18z, and then lower clouds will scatter out; but high cirrus around 20kft will have moved in by then. As the next system approaches the area, but moves south of the state, clouds will begin to lower during the early evening hours, after 00z, to around 8kft. Believe rain is possible at DEC and CMI TAFs during the overnight hours, so have included 5sm -ra with cigs just above the 3kft foot level. Other sites will not see rain, but see cigs fall to around 4-5kft late. West winds will remain gusty for a few hours this morning and then decrease for later this morning, with CMI being the last one to loose the gusts. As wind speeds decrease, direction will also become more northerly. Then northeast winds are expected tomorrow night. Auten && .PREV DISCUSSION... ISSUED 313 AM CDT Fri Mar 28 2014 SHORT TERM...Today through Sunday Main forecast challenge in the immediate short-term will be timing the departure of low clouds today. 07z/2am surface analysis shows low pressure over southern Lake Michigan with cold front trailing southward along the I-57 corridor. Extensive area of wrap-around cloud cover is noted on IR satellite imagery blanketing Iowa, northern Missouri, and western Illinois. With low-level flow becoming northwesterly, these clouds will spill across central Illinois early this morning. All model guidance suggests an overcast start to the day, but how quickly the clouds clear out remains in question. NAM forecast soundings indicate clouds will mix out/dissipate between 15z and 18z. Latest HRRR hints at this as well, although the process may be slower than the NAM advertises. Given subsidence behind departing upper short-wave and late March sun working on the low clouds, think skies will temporarily clear around midday into the early afternoon. After that, high clouds will quickly begin to increase ahead of the next approaching system by mid to late afternoon. Next forecast concern revolves around low pressure expected to track from Texas into the Tennessee River Valley tonight. Models have been having difficulty resolving how far north associated precip will spread. 00z Mar 28 suite is still in disagreement, with the GFS being the most aggressive in bringing precip furthest north. Since GFS is often too bullish with light QPF events and airmass will be drying today, think the NAM has a more realistic handle on the situation. As such, will keep locations along and north of a Jacksonville to Bloomington line dry tonight. Best rain chances will be focused along/south of I-70 in closer proximity to the low track, with POPs steadily decreasing further northwest. Despite overnight lows in the middle to upper 30s, NAM forecast soundings remain warm enough for rain. If colder/further north GFS verifies, a rain/snow mix may be possible along the northern fringe of the precip area. Will leave mention of mix out of the forecast due to skepticism about the GFS QPF field. After a few lingering showers across the far E/SE KILX CWA Saturday morning, dry and warmer weather will be the rule this weekend. As southerly winds develop, high temperatures will climb into the lower to middle 60s by Sunday. LONG TERM...Monday through Thursday Models are still advertising cold frontal passage late Monday, although amount of available moisture appears to be quite limited. GFS surface dewpoints are initially around 40 degrees Monday morning and only climb to the upper 40s to near 50 by late afternoon. Despite decent upper dynamics associated with vigorous short-wave, lack of deep moisture return from the Gulf will limit convective potential. As a result, will only carry low chance for showers on Monday. Slightly cooler and drier weather will settle into the region behind the departing front on Tuesday before another system comes into the picture by mid-week. There are still some key timing differences with this feature: however, all models agree that it will have much more moisture to work with. With short-wave crossing the Rockies into the central CONUS, surface low pressure is expected to track from eastern Colorado on Tuesday to the southern Great Lakes by Thursday night. Initial surge of WAA clouds/precip will arrive Tuesday night into Wednesday: however, with central Illinois remaining in the cool sector, very little thunder is expected. Once warm front lifts northward into the area and low pressure approaches from the southwest, showers and thunderstorms will become more prevalent Wednesday night into Thursday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
702 AM CDT FRI MAR 28 2014 .DISCUSSION... 323 AM CDT TODAY... SURFACE COLD FRONT IS CLEARING THE EASTERN COUNTIES IN THE CWA EARLY THIS MORNING WHILE A SECONDARY TROUGH IS DIGGING ACROSS NORTHERN ILLINOIS WITH WINDS TURNING SHARPLY TO THE NNW WITH GUSTS WELL INTO THE 20 KT RANGE. SHOWERS BEHIND THIS TROUGH WILL SWEEP ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...EXITING TO THE EAST BY MID TO LATE MORNING. BREEZY CONDITIONS THIS MORNING SHOULD GRADUALLY TAPER THROUGH THE DAY AS THE AS THE LOW LIFTS TOWARDS QUEBEC AND FILLS. TEMPS INTO THE MID TO UPPER 40S ARE EXPECTED THIS AFTERNOON...BUT A LAKE BREEZE WILL TURN WINDS NORTHEASTERLY AND COOL TEMPS BACK INTO THE 30S ALONG THE LAKE. THIS WEEKEND... LOW PRESSURE WILL LIFT FROM ARKLATEX INTO THE UPPER OHIO VALLEY BY MIDDAY SATURDAY. BEST CHANCES FOR PRECIP WILL BE SOUTH OF I-80 ESPECIALLY IN NORTHWEST INDIANA...AND FOR NOW IT APPEARS AREAS NORTH WILL REMAIN DRY. GFS INDICATES WET BULBS DROPPING BELOW ZERO THROUGH THE COLUMN AROUND OR BEFORE THE ONSET OF PRECIP INDICATE ALL SNOW. NAM SOUNDINGS ON THE OTHER HAND SHOW SLIGHTLY WARMER TEMPS ALOFT HINTING AT THE POSSIBILITY FOR RAIN/SNOW MIX...THOUGH SREF P-TYPE PROBABILITY INDICATES BETTER CHANCES FOR SNOW. COMING OFF HIGHS IN THE UPPER 40S IN AREAS MOST LIKELY TO SEE PRECIP...AND OVERNIGHT LOWS SOUTH OF 80 AT OR EVEN SLIGHTLY ABOVE FREEZING...THE LIKELIHOOD OF ACCUMULATING SNOW IS LOW AND WOULD LIKELY BE CONFINED TO THE GRASS. IN ADDITION...GIVEN THE MARGINAL SOUNDINGS...SNOW PRODUCTION WOULD BE INEFFICIENT. WILL MAINTAIN RAIN/SNOW MIX IN THE FORECAST FOR NOW GIVEN THE CURRENT UNCERTAINTY. HIGH PRESSURE WILL THEN TRANSLATE ACROSS THE REGION OVER THE REMAINDER OF THE WEEKEND RESULTING IN DRY WEATHER FROM SATURDAY AFTERNOON ON. H85 THERMAL TROUGH WILL APPROACH THE REGION ON SATURDAY...THOUGH SUBSIDENCE ALOFT SETTLING OVER THE UPPER MIDWEST THROUGH THE DAY SATURDAY WILL RESULT IN DRYING AND WARMING OF THE MIDLEVELS WHICH WILL HELP MODULATE THE COLDER AIRMASS MOVING OVERHEAD. WITH AFTERNOON SUNSHINE...EXPECT AREAS AWAY FROM THE LAKE TO RISE INTO THE MID TO UPPER 40S AGAIN...WITH A FEW 50S MAINLY SOUTH OF I-80. ALONG THE LAKE FRONT...A BREEZE OFF THE LAKE THROUGH THE DAY WILL KEEP TEMPERATURES MUCH COOLER...IN THE MID 30S. THE SURFACE RIDGE AXIS WILL PASS OVERHEAD SATURDAY NIGHT...AND SOUTHERLY FLOW WILL RAMP UP THROUGH THE DAY SUNDAY AHEAD OF OUR NEXT AREA OF LOW PRESSURE STARTING TO TAKE SHAPE OVER THE PLAINS. STRONG WARM ADVECTION IS EXPECTED THROUGH THE DAY SUNDAY WHICH WILL RESULT IN H85 TEMPS RISING TO AROUND 10C BY SUNDAY EVENING. SOUTHERLY WINDS MAY TAKE ON A SLIGHT WESTERLY COMPONENT BY SUNDAY AFTERNOON...IN THE 190-200 DIRECTION...WHICH WITH THE INCREASING WINDS SHOULD HELP STAVE OFF ANY LAKE BREEZE/LAKE COOLING SUNDAY. NAM/GFS SOUNDINGS SHOW LOW TO MID 20 KT GUSTS POSSIBLE BY SUNDAY AFTERNOON. TEMPERATURES SHOULD RISE TO AROUND 60 RIGHT UP TO THE LAKE FRONT SUNDAY AFTERNOON. MONDAY... AFOREMENTIONED SURFACE LOW PROGGED TO LIFT FROM THE MID MISSOURI VALLEY EARLY MONDAY INTO MN/WI MONDAY EVENING. LATEST GUIDANCE IN DECENT AGREEMENT ON THE LOCAL AREA GETTING FULL WARM SECTOR ON MONDAY. LEANED TOWARD WARMER SIDE OF GUIDANCE MONDAY WITH A BLEND OF BIAS CORRECTED GEM AND ECMWF. THIS RESULTS IN LOW TO MID 60S AREA WIDE MONDAY AFTERNOON...AND WITH A MODERATE-STRONG SSW WIND...DO NOT ANTICIPATE ANY COOLING ALONG THE LAKE. A 60-70KT LOW LEVEL JET FOCUSES STRONG CONVERGENCE ACROSS THE MID MISSOURI VALLEY SUNDAY NIGHT...THEN AT 40-50 KT REFOCUSES TO OUR NORTH MONDAY EVENING/NIGHT. ACROSS NORTHERN ILLINOIS IN THE WARM SECTOR... INSTABILITY IS PRETTY MEAGER WITH A STRONG CAP IN PLACE...THOUGH SOME DYNAMIC COOLING ASSOCIATED WITH NEGATIVELY TILTED H5 WAVE AND EXIT REGION OF UPPER JET MAY RESULT IN SOME SCATTERED CONVECTION. ALL-IN-ALL THOUGH...GIVEN THE UNFAVORABLE TIMING OF THE FRONT OVERNIGHT...NOT TOO IMPRESSED WITH PRECIP CHANCES MONDAY AND TRIMMED POPS FOR THIS PERIOD. TUESDAY THROUGH THURSDAY... PRETTY LOW CONFIDENCE IN THE DETAILS AT THIS POINT...BUT TUESDAY THROUGH THURSDAY SHOULD BE AN ACTIVE PERIOD WITH A SERIES OF DISTURBANCES MOVING ACROSS THE REGION. THERE REMAINS SIGNIFICANT DIFFERENCES AT THIS POINT BETWEEN MODELS WITH RESPECT TO THE LOW TRACK WHICH WILL DETERMINE TEMPS AND PRECIP TYPE. GFS INDICATES A FASTER MORE SOUTHERLY LOW WHILE THE ECMWF HINTS AT A WARMER SOLUTION WITH A DEEPER LOW THAT TRACKS FARTHER NORTH. FOR NOW...STAYED CLOSE TO A CONSENSUS BLEND. DEUBELBEISS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 12Z... * PERIODS OF IFR CIGS WITH RAIN SHOWERS EARLY THIS MORNING...THEN MVFR INTO AFTERNOON. * NORTHWEST WINDS GUSTY AT TIMES...TURNING NORTH BY MIDDAY AND NORTHEAST BY AFTERNOON. LENNING //DISCUSSION...UPDATED 12Z... RAIN SHOWERS WITH POCKETS OF IFR WRAPPING AROUND THE BACK SIDE OF A DEPARTING LOW WILL CLEAR THE AREA BY MID MORNING. WINDS HAVE TURNED NORTHWEST AND WILL CONTINUE TO VEER AROUND TO NORTHEAST BY THE AFTERNOON. NOT CERTAIN ABOUT TIMING OF CHANGE OVER TO AN EASTERLY COMPONENT BUT BEST ESTIMATE IS AROUND NOON OR SHORTLY AFTER. LINGERING MVFR CIGS LATE THIS MORNING WILL EVENTUALLY SCATTER OUT TO VFR THIS AFTERNOON. LENNING //ORD AND MDW CONFIDENCE...UPDATED 12Z... * MEDIUM CONFIDENCE ON TIMING AND DURATION OF IFR EARLY THIS MORNING...BUT HIGHER CONFIDENCE OF PREVAILING MVFR LATER. * HIGH CONFIDENCE THAT RAIN SHOWERS WILL END BY MID MORNING. * MEDIUM CONFIDENCE ON TIMING OF WIND DIRECTION CHANGES. LENNING //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...VFR. NORTHEAST WINDS TURNING SOUTHEAST. SUNDAY...VFR. SOUTH WINDS. MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS. TUESDAY...VFR PROBABLE. WEST WINDS. WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS. THURSDAY...CHANCE OF RAIN OR SNOW AND IFR/MVFR. NORTHEAST WINDS. LENNING && .MARINE... 307 AM CDT A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE...AS THE LOW MOVES THROUGH. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY. SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 11 AM FRIDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 2 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 646 AM CDT Fri Mar 28 2014 .DISCUSSION... ISSUED 313 AM CDT Fri Mar 28 2014 SHORT TERM...Today through Sunday Main forecast challenge in the immediate short-term will be timing the departure of low clouds today. 07z/2am surface analysis shows low pressure over southern Lake Michigan with cold front trailing southward along the I-57 corridor. Extensive area of wrap-around cloud cover is noted on IR satellite imagery blanketing Iowa, northern Missouri, and western Illinois. With low-level flow becoming northwesterly, these clouds will spill across central Illinois early this morning. All model guidance suggests an overcast start to the day, but how quickly the clouds clear out remains in question. NAM forecast soundings indicate clouds will mix out/dissipate between 15z and 18z. Latest HRRR hints at this as well, although the process may be slower than the NAM advertises. Given subsidence behind departing upper short-wave and late March sun working on the low clouds, think skies will temporarily clear around midday into the early afternoon. After that, high clouds will quickly begin to increase ahead of the next approaching system by mid to late afternoon. Next forecast concern revolves around low pressure expected to track from Texas into the Tennessee River Valley tonight. Models have been having difficulty resolving how far north associated precip will spread. 00z Mar 28 suite is still in disagreement, with the GFS being the most aggressive in bringing precip furthest north. Since GFS is often too bullish with light QPF events and airmass will be drying today, think the NAM has a more realistic handle on the situation. As such, will keep locations along and north of a Jacksonville to Bloomington line dry tonight. Best rain chances will be focused along/south of I-70 in closer proximity to the low track, with POPs steadily decreasing further northwest. Despite overnight lows in the middle to upper 30s, NAM forecast soundings remain warm enough for rain. If colder/further north GFS verifies, a rain/snow mix may be possible along the northern fringe of the precip area. Will leave mention of mix out of the forecast due to skepticism about the GFS QPF field. After a few lingering showers across the far E/SE KILX CWA Saturday morning, dry and warmer weather will be the rule this weekend. As southerly winds develop, high temperatures will climb into the lower to middle 60s by Sunday. LONG TERM...Monday through Thursday Models are still advertising cold frontal passage late Monday, although amount of available moisture appears to be quite limited. GFS surface dewpoints are initially around 40 degrees Monday morning and only climb to the upper 40s to near 50 by late afternoon. Despite decent upper dynamics associated with vigorous short-wave, lack of deep moisture return from the Gulf will limit convective potential. As a result, will only carry low chance for showers on Monday. Slightly cooler and drier weather will settle into the region behind the departing front on Tuesday before another system comes into the picture by mid-week. There are still some key timing differences with this feature: however, all models agree that it will have much more moisture to work with. With short-wave crossing the Rockies into the central CONUS, surface low pressure is expected to track from eastern Colorado on Tuesday to the southern Great Lakes by Thursday night. Initial surge of WAA clouds/precip will arrive Tuesday night into Wednesday: however, with central Illinois remaining in the cool sector, very little thunder is expected. Once warm front lifts northward into the area and low pressure approaches from the southwest, showers and thunderstorms will become more prevalent Wednesday night into Thursday. Barnes && .AVIATION... ISSUED 646 AM CDT Fri Mar 28 2014 MVFR cigs will continue this morning. Big question is how long will these clouds last. This time of year, clouds at this level usually burn off rather quickly. However, area is in good cyclonic flow will lots of clouds/low level moisture across most of MO, all of Iowa and up into WI. So, think that these clouds will last longer than normal. So have the MVFR cigs continuing until around 18z, and then lower clouds will scatter out; but high cirrus around 20kft will have moved in by then. As the next system approaches the area, but moves south of the state, clouds will begin to lower during the early evening hours, after 00z, to around 8kft. Believe rain is possible at DEC and CMI TAFs during the overnight hours, so have included 5sm -ra with cigs just above the 3kft foot level. Other sites will not see rain, but see cigs fall to around 4-5kft late. West winds will remain gusty for a few hours this morning and then decrease for later this morning, with CMI being the last one to loose the gusts. As wind speeds decrease, direction will also become more northerly. Then northeast winds are expected tomorrow night. Auten && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
315 AM CDT FRI MAR 28 2014 .DISCUSSION... 801 PM CDT ONLY SOME MINOR TWEAKS HAVE BEEN MADE TO THE GOING FORECAST FOR THE REST OF TONIGHT INTO EARLY FRIDAY MORNING. THE PRIMARY TIME FOR RAIN SHOWERS WITH SOME SCATTERED THUNDERSTORMS REMAINS NOW THROUGH MIDNIGHT. A WELL-DEFINED SHORT-WAVE TROUGH FROM MN INTO CENTRAL MN THIS EARLY EVE IS ADVANCING EAST NORTHEASTWARD. THE 00Z RAOB SOUNDINGS AND PROFILERS INDICATED A 55-60 KT LOW LEVEL JET AHEAD OF THIS INTO THE FORECAST AREA. SOME OF THE BETTER DEEPER MOISTURE RETURN THAT COULD BE ASSOCIATED WITH THIS IS LIKELY BEING ROBBED BY QUITE A BIT OF CONVECTION ACROSS THE LOWER MISSISSIPPI VALLEY...AS WELL AS THE SUBTROPICAL JET REMAINING WELL SOUTH. NONETHELESS...NORTH-TO-SOUTH ARCS OF CONVECTION AHEAD OF THE MAIN VORT MAX CONTINUE TO PROGRESS ACROSS NORTHERN AND WESTERN IL AND SHOULD CONTINUE AT A SIMILAR COVERAGE INTO THE CHICAGO AREA. THE DEGREE OF LIGHTNING HAS FLUCTUATED SOME BUT CONFINED TO WITHIN A NARROW AXIS OF DWINDLING MUCAPE AHEAD OF THE SYSTEM. SOME BRIEF DOWNPOURS AND MAYBE A FEW BOOSTS TO THE ALREADY HIGH SYNOPTIC GUSTS...BUT ALL-IN-ALL JUST SOME GARDEN VARIETY SCATTERED STORMS AS EXPECTED. AS A DRY CONVEYOR BELT AS SEEN ON WATER VAPOR AND UPPER AIR RAOBS IN KS ROTATES INTO THE FORECAST AREA EARLY OVERNIGHT THERE SHOULD STILL BE A LULL IN ACTIVITY...WITH SOME UPTICK EXPECTED BETWEEN 3-8 AM NORTH OF I-80 AS THE CENTER OF THE WAVE PASSES AND TAPS SOME WRAPAROUND MOISTURE. IF THE LOW-LEVELS COOL ENOUGH...SOME WET SNOW IS POSSIBLE INTO THE EARLY PART OF THE MORNING RUSH. WITH SURFACE TEMPS SEVERAL DEGREES ABOVE FREEZING AND ROADS ALREADY WET...WOULD NOT SEEM LIKE MUCH FOR IMPACTS. TEMPERATURES WILL CONTINUE TO HOLD STEADY IN THE STRONG SOUTHERLY FLOW WITH ADVECTION AND HIGHER DEW POINT AIR HELPING TO MAINTAIN TEMPERATURES IN THE UPPER 40S TO MID 50S FAR SOUTH. AS THE FRONT PASSES DURING THE EARLY OVERNIGHT...READINGS SHOULD STEADILY HEAD DOWNWARD WITH GOING FORECAST HOURLY TEMPS AND LOWS LOOKING ON TRACK. MTF //PREV DISCUSSION... 300 PM...FORECAST CONCERNS INCLUDE THUNDERSTORM POTENTIAL THIS EVENING...MIX OF RAIN/SNOW EARLY FRIDAY MORNING...LAKE BREEZES FRIDAY AND SATURDAY...CHANCE OF RAIN/SNOW FRIDAY NIGHT SOUTH... TEMPS AROUND 60 SUNDAY/MONDAY AND ANOTHER CHANCE OF THUNDERSTORMS MONDAY AFTERNOON/EVENING. TEMPS HAVE STRUGGLED INTO THE LOWER/MID 40S THIS AFTERNOON WITH BREEZY SOUTHERLY WINDS...WHICH HAVE BEEN LOWER THAN EXPECTED. CURRENT SHOWER ACTIVITY WILL MOVE NORTHEAST OF THE CWA IN THE NEXT 1-2 HOURS WITH A 2-4 HOUR DRY PERIOD INTO EARLY THIS EVENING. LOW PRESSURE OVER SOUTHWEST IOWA WILL LIFT NORTHEAST ACROSS SOUTHERN WISCONSIN THIS EVENING WITH A TRAILING COLD FRONT MOVING ACROSS THE AREA THIS EVENING. LINE OF THUNDERSTORMS HAS DEVELOPED AHEAD OF THIS COLD FRONT ACROSS EASTERN KANSAS AND WESTERN MISSOURI. THIS ACTIVITY WILL ACCOMPANY THE FRONT THIS EVENING THOUGH SHORT TERM/HIGH RES GUIDANCE DIFFERS ON THUNDER COVERAGE/INTENSITY LATER THIS EVENING. POSSIBLE THAT SOME OF THIS WILL LIFT NORTH WITH THE LOW AND THE MAIN LINE MOVES EAST ACROSS CENTRAL IL. THUS HAVE MAINTAINED CHANCE THUNDER MENTION WHICH MAY NEED TO BE INCREASED AS THE LINE APPROACHES. THUNDER POTENTIAL/DURATION WILL ONLY LAST AN HOUR OR TWO. PRECIP EXPECTED TO END BEHIND THE FRONT BUT THEN WRAP AROUND PRECIP ON THE BACK SIDE OF THE LOW WILL SPREAD BACK ACROSS NORTHERN ILLINOIS OVERNIGHT PERHAPS LINGERING INTO EARLY FRIDAY MORNING. AS COLDER AIR SPREADS BACK ACROSS THE REGION...PRECIP WILL CHANGE TO A MIX OF RAIN/SNOW WITH PERHAPS PRECIP BECOMING ALL SNOW BEFORE ENDING ACROSS THE FAR NORTH. WHILE NO ACCUMULATION IS IN THE FORECAST...IF PRECIP WERE TO CHANGE OVER TO SNOW SOONER...THEN ITS POSSIBLE THERE COULD BE SOME MINOR SNOW ACCUMULATIONS...AGAIN MAINLY ACROSS THE FAR NORTHERN CWA. TEMPERATURES WILL CONTINUE TO CLIMB THIS AFTERNOON INTO THIS EVENING WITH CALENDAR DAY HIGHS LIKELY TO OCCUR IN THE MID/LATE EVENING AHEAD OF THE FRONT. NOT OUT OF THE QUESTION FOR SOME LOWER 50S TO MAKE IT AS FAR NORTH AS THE CHICAGO METRO AREA WITH STRONG SOUTHERLY FLOW...BUT THESE TEMPS WILL BE SHORT-LIVED. AS NOTED... WINDS HAVE NOT BEEN AS STRONG AS ORIGINALLY EXPECTED. HOWEVER... AS THE LOW APPROACHES AND ONGOING SHOWER ACTIVITY ENDS...EXPECT WINDS/GUSTS TO INCREASE THROUGH THE LATE AFTERNOON AND INTO THE EVENING WITH GUSTS UP TO 40 MPH STILL POSSIBLE...PERHAPS A BIT STRONGER JUST AHEAD AND JUST BEHIND THE FRONT. ONCE THE PRECIP ENDS FRIDAY MORNING...NORTHERLY WINDS WILL TURN MORE NORTHEAST AS HIGH PRESSURE BUILDS ACROSS THE UPPER MIDWEST. GUIDANCE SUGGESTS A RATHER STRONG LAKE BREEZE/FRONT MOVING IN FROM THE LAKE IN THE AFTERNOON AND HAVE ATTEMPTED TO ACCOUNT FOR THAT WITH FALLING TEMPS IN THE AFTERNOON AS WINDS SHIFT NORTHEAST. AHEAD OF THAT LAKE BREEZE...HIGHS IN THE LOWER/MID 40S LOOK ON TRACK WITH UPPER 40S/NEAR 50 FURTHER INLAND...WESTERN/SOUTHERN CWA. NOT MUCH CONFIDENCE REGARDING THE NEXT SYSTEM MOVING THROUGH THE OHIO VALLEY FRIDAY NIGHT INTO SATURDAY MORNING. MODELS HAVE TRENDED A BIT FURTHER SOUTHEAST AND PRECIP COULD END UP STAYING MAINLY SOUTH OF THE AREA. ONLY CHANGE TO THIS TIME PERIOD WAS TO SHIFT THE PRECIP EDGE A BIT FURTHER SOUTH TO THE I-80 CORRIDOR. PRECIP TYPE ALSO REMAINS PROBLEMATIC...ASSUMING IT PRECIPITATES THIS FAR NORTH WITH THE POTENTIAL FOR SOME FREEZING RAIN IF SURFACE TEMPS WERE TO DROP BELOW FREEZING BY SATURDAY MORNING. WITH THE EXCEPTION OF ANY LINGERING PRECIP SATURDAY MORNING OVER THE FAR SOUTHEAST...THE WEEKEND STILL ON TRACK TO BE DRY THOUGH SATURDAY WILL BE CHILLY OVER MUCH OF THE METRO AREA WITH A LAKE BREEZE KEEPING THE LAKESHORE AREAS ONLY IN THE 30S. FLOW QUICKLY SHIFTS SOUTHERLY SATURDAY NIGHT INTO SUNDAY WITH BREEZY SOUTHERLY WINDS PUSHING TEMPS INTO THE UPPER 50S/LOWER 60S. EXPECT SOME SORT OF SOUTHEASTERLY COMPONENT ALONG THE IL SHORE...SO LAKESHORE AREAS FROM DOWNTOWN NORTH COULD BE CONSIDERABLY COLDER. MODELS CONTINUE TO SLOW THE NEXT LOW MOVING ACROSS THE MIDWEST ON MONDAY...ONLY TO WESTERN WISCONSIN BY MONDAY EVENING. THIS SHOULD PROVIDE STRONG SOUTHWESTERLY WINDS OVER THE ENTIRE AREA HELPING TO PUSH TEMPS INTO THE LOWER 60S OVER MUCH OF THE AREA. HAVE REMOVED PRECIP MONDAY MORNING EXCEPT THE FAR NORTHWEST AND ADDED THUNDER BACK TO THE FORECAST FOR THE AFTERNOON. TIMING STILL UNCERTAIN FROM THIS DISTANCE BUT WITH A COLD FRONT EXPECT TO MOVE ACROSS THE AREA EITHER LATE MONDAY AFTERNOON OR MONDAY EVENING...THUNDER LOOKS REASONABLE. PROGRESSIVE PATTERN CONTINUES WITH ANOTHER STORM SYSTEM LIFTING NORTHEAST ACROSS THE OHIO VALLEY AND SOUTHERN LAKES REGION TUESDAY NIGHT THROUGH THURSDAY. MODEL CONSENSUS IS TO KEEP MUCH OF THE AREA ON THE NORTHERN AND COLDER SIDE OF THIS SYSTEM MAKING PRECIP TYPE A LITTLE TRICKY. HAVE STAYED RAIN DURING THE DAY WITH A MIX AT NIGHT MAINLY NORTH...BUT CURRENT THERMAL PROFILES WOULD SUGGEST MAINLY RAIN THROUGH THE EVENT. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * STRONG AND GUSTY SOUTH WINDS WILL RELAX AND TURN MORE WESTERLY. * MVFR CIGS WILL PERSIST THROUGH THE MORNING...AND POSSIBLY DROP TO IFR WITH SECOND WAVE OF RAIN OR LIGHT SNOW. VFR THIS AFTERNOON. LENNING //DISCUSSION...UPDATED 06Z... A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THROUGH LOWER MICHIGAN. AS THE LOW MOVES OUT...WINDS WILL VEER FROM SOUTH TO WEST OVERNIGHT AND THEN AROUND TO NORTHEAST BY AFTERNOON. CEILINGS GENERALLY ARE STAYING AT MVFR FOR THE TIME BEING...BUT RAIN SHOWERS WRAPPING AROUND THE LOW MAY BRIEFLY DROP CIGS TO IFR TOWARD MORNING AS THEY PASS THROUGH. SKIES LIKELY SCATTER OUT DURING THE LATE MORNING OR AFTERNOON AS DRIER AIR MOVES IN AHEAD OF AN APPROACHING HIGH. LENNING //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM CONFIDENCE ON TIMING OF WIND DIRECTIONAL CHANGES. * MEDIUM TO HIGH CONFIDENCE ON CEILING TRENDS...THOUGH LOWER CONFIDENCE REGARDING IFR TOWARD MORNING. LENNING //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... SATURDAY...VFR. NORTHEAST WINDS. SUNDAY...VFR. SOUTH WINDS. MONDAY...CHANCE OF SHRA/TSRA LATE. MODERATE-STRONG SOUTH WINDS. TUESDAY...VFR PROBABLE. WEST WINDS. WEDNESDAY...CHANCE OF RAIN AND IFR/MVFR CIGS. NORTHEAST WINDS. IZZI && .MARINE... 307 AM CDT A STRONG LOW PRESSURE SYSTEM IS EXITING THE AREA THIS MORNING ACROSS LOWER MICHIGAN AND LAKE HURON. NORTHWEST TO NORTH GALES WILL EASE QUICKLY THIS MORNING AS THE LOW PULLS AWAY AND THE PRESSURE GRADIENT WEAKENS. A RIDGE WILL CROSS THE LAKE ON SATURDAY BEFORE THE NEXT LOW PRESSURE SYSTEM STARTS TO APPROACH OUT OF THE CENTRAL PLAINS. ALTHOUGH THIS LOW DOES NOT REACH THE LAKE UNTIL TUESDAY...SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL DEVELOP BY EARLY SUNDAY. A PERIOD OF GALES IS AGAIN POSSIBLE LATE MONDAY INTO TUESDAY...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE...AS THE LOW MOVES THROUGH. LENNING && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 AM FRIDAY. GALE WARNING...NEARSHORE WATERS UNTIL 4 AM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 313 AM CDT Fri Mar 28 2014 .DISCUSSION... ISSUED 313 AM CDT Fri Mar 28 2014 SHORT TERM...Today through Sunday Main forecast challenge in the immediate short-term will be timing the departure of low clouds today. 07z/2am surface analysis shows low pressure over southern Lake Michigan with cold front trailing southward along the I-57 corridor. Extensive area of wrap-around cloud cover is noted on IR satellite imagery blanketing Iowa, northern Missouri, and western Illinois. With low-level flow becoming northwesterly, these clouds will spill across central Illinois early this morning. All model guidance suggests an overcast start to the day, but how quickly the clouds clear out remains in question. NAM forecast soundings indicate clouds will mix out/dissipate between 15z and 18z. Latest HRRR hints at this as well, although the process may be slower than the NAM advertises. Given subsidence behind departing upper short-wave and late March sun working on the low clouds, think skies will temporarily clear around midday into the early afternoon. After that, high clouds will quickly begin to increase ahead of the next approaching system by mid to late afternoon. Next forecast concern revolves around low pressure expected to track from Texas into the Tennessee River Valley tonight. Models have been having difficulty resolving how far north associated precip will spread. 00z Mar 28 suite is still in disagreement, with the GFS being the most aggressive in bringing precip furthest north. Since GFS is often too bullish with light QPF events and airmass will be drying today, think the NAM has a more realistic handle on the situation. As such, will keep locations along and north of a Jacksonville to Bloomington line dry tonight. Best rain chances will be focused along/south of I-70 in closer proximity to the low track, with POPs steadily decreasing further northwest. Despite overnight lows in the middle to upper 30s, NAM forecast soundings remain warm enough for rain. If colder/further north GFS verifies, a rain/snow mix may be possible along the northern fringe of the precip area. Will leave mention of mix out of the forecast due to skepticism about the GFS QPF field. After a few lingering showers across the far E/SE KILX CWA Saturday morning, dry and warmer weather will be the rule this weekend. As southerly winds develop, high temperatures will climb into the lower to middle 60s by Sunday. LONG TERM...Monday through Thursday Models are still advertising cold frontal passage late Monday, although amount of available moisture appears to be quite limited. GFS surface dewpoints are initially around 40 degrees Monday morning and only climb to the upper 40s to near 50 by late afternoon. Despite decent upper dynamics associated with vigorous short-wave, lack of deep moisture return from the Gulf will limit convective potential. As a result, will only carry low chance for showers on Monday. Slightly cooler and drier weather will settle into the region behind the departing front on Tuesday before another system comes into the picture by mid-week. There are still some key timing differences with this feature: however, all models agree that it will have much more moisture to work with. With short-wave crossing the Rockies into the central CONUS, surface low pressure is expected to track from eastern Colorado on Tuesday to the southern Great Lakes by Thursday night. Initial surge of WAA clouds/precip will arrive Tuesday night into Wednesday: however, with central Illinois remaining in the cool sector, very little thunder is expected. Once warm front lifts northward into the area and low pressure approaches from the southwest, showers and thunderstorms will become more prevalent Wednesday night into Thursday. Barnes && .AVIATION... ISSUED 1153 PM CDT Thu Mar 27 2014 Band of storms has now passed east of KCMI. Cold front now approaching KPIA with a wind shift from 200-230 to 260-290. Winds should remain gusty until the surface low over southwest Wisconsin pushes into the Great lakes toward 12z. Low clouds are wrapping around the system and are moving into KPIA attm and should push into KBMI and KSPI by TAF valid time and swing into KDEC and KCMI shortly after, Cigs are pretty uniform low MVFR or high VFR. Since low is pulling away will go with Cigs in the MVFR range for the most part through mid-morning. Wave is expected to move northeastward along the front through the Tennessee Valley. Some question as to how far to the northwest moisture will be able to extend. Any precip would likely be after 06z. However, VFR Cigs are likely by late afternoon. Although CIGs may drop into MVFR by 06z at KSPI and KDEC, given the uncertianty in the extent of moisture will keep things VFR for now. Barker && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
800 PM EDT SAT MAR 29 2014 .SYNOPSIS... ISSUED AT 758 PM EDT SAT MAR 29 2014 SKIES WILL CONTINUE TO CLEAR THIS EVENING. OVERNIGHT LOWS WILL BE COLD IN THE LOWER TO MID 20S. TEMPERATURES WILL THEN WARM UP NICELY ON SUNDAY INTO THE LOWER TO MID 50S. EVEN WARMER CONDITIONS ARE ANTICIPATED ON MONDAY AS HIGH TEMPERATURES RISE INTO THE MID 60S UNDER PARTLY CLOUDY SKIES. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 328 PM EDT SAT MAR 29 2014 NO SIG ISSUES TO WORRY ABOUT FOR THE SHORT TERM AS RAIN/SNOW THAT HAS FELL ACROSS MUCH OF THE SOUTHERN GREAT LAKES TODAY WAS NEARLY OUT OF THE FORECAST AREA. FOCUS WILL SHIFT TO CLEARING TONIGHT AND HOW WARM WE GET ON SUNDAY. BY IN LARGE THE HEAVIER SNOWBANDS HAVE DIMINISHED WITH REMAINING RAIN/SNOW ACROSS PORTIONS OF HENRY/PUTNAM AND ALLEN COUNTIES IN OHIO. SFC LOW WAS OVER NE TENNESSEE AT 18Z AND SLOWLY DEEPENING WITH AN INCREASING PRESSURE GRADIENT AROUND IT. THIS WILL KEEP SOMEWHAT BREEZY CONDITIONS MAINLY EAST INTO THIS EVENING BEFORE THE LOW SHIFTS EAST. LOW CLOUDS HAVE BEEN SLOW TO ERODE IN THE WEST AND NORTH WITH NAM AND RUC VARYING ON HANDLING OF CLEARING. RUC 925/850 MB RH PLOT HAVE HANDLED THINGS WELL AND LINGER LOW CLOUDS INTO LATE EVENING WITH NAM MUCH QUICKER ERODING MSTR. WITH VIS SAT SHOWING HINTS AT SOME THIN SPOTS STARTING TO APPEAR SO HAVE TRIED TO BLEND THE 2 MODELS WHICH STILL BRINGS GENERALLY CLEAR SKIES BY LATE EVENING. LOWS WILL DROP INTO THE 20S DESPITE COLDEST AIR WITH THE SYSTEM ALREADY EAST OF THE REGION AND WAA UNDERWAY LATER TONIGHT. SOME OF THIS WAA WILL BE REALIZED ON SUNDAY AS LOTS OF SUNSHINE ALLOWS FOR MIXING THROUGH AT LEAST 900 MB AND MAYBE A BIT HIGHER YIELDS HIGHS IN THE 50S. WOULDN`T BE ENTIRELY SURPRISED TO SEE SOME UPR 50S TO NEAR 60 IN FAR W/SW AREAS. && .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 328 PM EDT SAT MAR 29 2014 VERY FEW CHANGES TO OVERALL IDEA IN LONG TERM PERIOD. AN ACTIVE PATTERN WILL CONTINUE THROUGH THE PERIOD WITH NUMEROUS SHORT WAVES AND A QUASI STATIONARY BOUNDARY IN THE REGION. THIS SHOULD LEAD TO RATHER WET PERIOD WITH TEMPERATURES A LITTLE CLOSER TO NORMAL FOR EARLY APRIL. RIDGE WILL BE OVER THE AREA SUNDAY NIGHT PROVIDING CLEAR SKIES AND LIGHT WINDS. LOWS EXPECTED IN THE LOWER 30S EAST UNDER RIDGE AXIS TO UPPER 30S WEST WHERE WARM AIR ADVECTION ON BACK SIDE OF RIDGE WILL BE INCREASING. THIS WARMING SHOULD TRANSLATE TO A LARGE DIURNAL SWING ON MONDAY AS STRONG MIXING DEVELOPS AND WARM AIR ALOFT IS ALLOWED TO MIX TO SURFACE. SHOULD BECOME BREEZY AS WELL TO HELP BOOST TEMPERATURES. INCREASING HIGH CLOUDS IN AFTERNOON MAY TEMPER WARM UP BY A FEW DEGREES DEPENDING ON HOW THICK CLOUD CANOPY IS AND TIMING OF IT. STILL EXPECT 60S ALL AREAS WITH RUN AT MID TO UPPER 60S ACROSS THE AREA IF SKIES REMAIN MOSTLY SUNNY THROUGH AFTERNOON PEAK HEATING. NEXT OF MANY SHORT WAVES MOVES THROUGH THE LAKES REGION MONDAY NIGHT WITH A TRAILING COLD FRONT THROUGH THE CWA EARLY TUESDAY MORNING. ENOUGH MOISTURE AND WEAK LIFT TO WARRANT LOW CHANCE POPS BUT STRONGEST FORCING TO THE NORTH CLOSER TO MAIN LOW. WARMEST TEMPS OF THE DAY LIKELY IN MORNING BEFORE FROPA BUT DRYING PROFILES TUE AFTERNOON SUGGEST SUN COULD ALLOW FOR SOME REBOUND SIMILAR TO WHAT SOME LOCATIONS EXPERIENCED FRIDAY. DETAILS REMAIN UNCERTAIN FOR REMAINDER OF LONG TERM WITH AFOREMENTIONED COLD FRONT BECOMING STATIONARY NEAR OR JUST SOUTH OF CWA. SEVERAL SHORT WAVES ARE EXPECTED WEDNESDAY INTO FRIDAY WITH ASSOCIATED SURFACE WAVES RIPPLING ALONG FRONTAL BOUNDARY. SEVERAL CHANCES FOR RAINFALL DURING THE PERIOD WITH UNCERTAINTY IN TIMING. THUS A CONTINUATION OF BROAD HIGH CHANCE POP CONTINUES WITH FURTHER INCREASE LIKELY AS TIME NEARS. WITH INCREASING PWATS AND THETA E AIR...MODERATE TO LOCALLY HEAVY RAINFALL AMOUNTS STILL PLAUSIBLE. TEMPS DURING THIS PERIOD LIKELY NEAR NORMAL SOUTH AND SLIGHTLY BELOW NORMAL NORTH BUT IF FRONT WAVERS NORTH OR SOUTH...SIGNIFICANT CHANGES IN TEMPERATURE FORECASTS WOULD BE EXPECTED. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 757 PM EDT SAT MAR 29 2014 LARGE SCALE SUBSIDENCE AND DRY AIR UNDERCUT BODES WELL FOR EARLIER TRANSITION TO DOMINANT VFR MET CONDS THAN PRIOR FCSTS FOR NRN IN. SOME CONCERN FOR AM BR FORMATION ESPCLY IN MAUMEE VALLEY/KFWA VCNTY. WHILE DRY AIR ADVECTION OVERNIGHT SHOULD GIVE SUFFICIENT COUNTER TO ARTIFICIALLY HIGH XOVER TEMP...DECOUPLED AIRMASS/WELL AND RECENTLY WETTED GROUND SUGGEST MODEST VSBY REDUCTION QUITE LIKELY NEAR DAYBREAK...HOWEVER HAVE REMAINED OPTIMISTIC/ABOVE SIG LEVELS FOR PLANNING PURPOSES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...BENTLEY/MURPHY SHORT TERM...FISHER LONG TERM...LASHLEY AVIATION...MURPHY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
324 PM CDT FRI MAR 28 2014 .SHORT TERM /TONIGHT/... ISSUED AT 237 PM CDT FRI MAR 28 2014 STRATUS HAS BEEN STUBBORN TO LEAVE AND WHILE CEILINGS WILL RAISE THROUGH THE EVENING THE LOW STRATUS SHOULD LINGER UNTIL AN UPPER LEVEL SHORTWAVE SWEEPS EAST THROUGH TONIGHT AND GRADUALLY SCOURS OUT MOISTURE. SATELLITE IS SHOWING SOME HIGHER LEVEL CLOUDS WITH THIS FEATURE SO WHILE THE LOW STRATUS CONDITIONS WILL IMPROVE WE SHOULD STILL KEEP AN OVERCAST CONDITION THROUGH THE EVENING WITH GRADUAL IMPROVEMENT AFT 08-09Z. CURRENT RADAR IS SHOWING SOME RETURNS OUT WEST BUT OBSERVATIONS CONFIRM THAT THE PRECIP IS NOT REACHING THE GROUND. THE NAM12 KEEPS CENTRAL IOWA DRY TONIGHT BUT THE RAP13 DOES PRINT OUT SOME QPF IN THE BROAD ASCENT AHEAD OF THE SHORTWAVE PASSING. IT CURRENTLY HAS A GOOD HANDLE ON WHERE PRECIP IS ON THE RADAR BUT IS OVERDOING IT BECAUSE THERE ARE NO SITES REPORTING PRECIP SO THE RAP IS LIKELY A BIT OVERDONE. EITHER WAY BOTH MODEL PRETTY MUCH WIPE ANY PRECIP OUT BEFORE IT MOVES MUCH INTO CENTRAL IOWA....WITH ONE EXCEPTION...THE RAP DOES DRIBBLE SOME SMALL QPF HERE AND THERE ACROSS CENTRAL IOWA THROUGH 06Z. FOR NOW I HAVE OPTED TO KEEP THE FORECAST AREA DRY AND ADVISE THE EVENING SHIFT THAT A COUPLE OF THE RETURNS ON RADAR...IF THEY HOLD AS THEY COME ACROSS CENTRAL IOWA...COULD PRODUCE A SPRINKLE OF FLURRY. TEMPS ARE THE NEXT ISSUE. THE LOW CLOUD COVER REALLY HAMMERED HIGHS TODAY WITH MOST LOCATIONS IN THE MID TO UPPER 30S. THE STRATUS EARLY ON WILL KEEP TEMPS UP AND I DO NOT EXPECT MUCH DIURNAL CHANGE THROUGH THE EVENING. HOWEVER I DO EXPECT CLOUDS TO CLEAR FROM WEST OR NORTHWEST TO EAST/SOUTHEAST OVERNIGHT. THIS WILL ALLOW A QUICKER FALL TO TEMPS OVERNIGHT EXCEPT FOR THE FAR SOUTHEAST WHERE CLOUDS WILL LINGER THE LONGEST. I EITHER WENT ABOVE GUIDANCE OR STAYED ON THE WARMER SIDE OF IT BASING THAT ON CLOUDS HANGING AROUND LONGER. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 237 PM CDT FRI MAR 28 2014 THE TRANSITION FROM WINTER TO SPRING APPEARS TO BE WELL UNDERWAY. THE PATTERN FOR THE NEXT WEEK LOOKS SEASONABLY ACTIVE WITH MULTIPLE SHORTWAVES MOVING THROUGH IN WESTERLY PROGRESSIVE FLOW. SATURDAY AND SUNDAY...GENERAL SUBSIDENCE BEHIND TONIGHT/S SHORTWAVE WILL PREVAIL ON SATURDAY. SURFACE RIDGE MOVES EAST BY EVENING. TEMPERATURES WILL RECOVER NICELY REACHING THE 50S IN MOST LOCATIONS. RIDGING ALOFT SATURDAY NIGHT AND SUNDAY AHEAD OF A POTENT SHORTWAVE SHOULD RESULT IN THE WARMEST TEMPERATURES SINCE LAST FALL ON SUNDAY. THE WARM UP HAS BEEN FORECAST FOR DAYS AND KEPT WARM TEMPERATURES GOING. BASED WINDS ON MIXED LAYER WINDS OR SLIGHTLY LESS SINCE IT IS A WARM ADVECTION SITUATION. MONDAY AND TUESDAY...USED 12Z ECMWF/GFS TO BASE FORECAST. 12Z NAM APPEARED TO BE AN OUTLIER. THE ECMWF/GFS WERE SLOWER AND STRONGER WITH THE SHORTWAVE ENERGY EMERGING FROM THE CENTRAL ROCKIES AT 12Z MONDAY. BOTH SOLUTIONS BRING A NEGATIVELY TILTED SHORTWAVE THROUGH CENTRAL IOWA ON MONDAY. THE ECMWF IS NORTH OF THE GFS SURFACE LOW POSITION AT 00Z TUESDAY. CENTRAL IOWA WILL BE IN THE WARM SECTOR WITH A COLD FRONT MOVING INTO THE WESTERN COUNTIES BY AFTERNOON AND A SURFACE LOW EITHER IN NORTHWEST IOWA OR NEARBY. LOOKING AT THE MODEL SOUNDINGS...THE LIMITING FACTOR FOR SEVERE WEATHER WILL BE TIMING CONSIDERATIONS AND THE AMOUNT OF LOW-LEVEL MOISTURE TRANSPORTED INTO IOWA AHEAD OF THE SYSTEM. IF THINGS COME TOGETHER IT COULD GET INTERESTING MONDAY EVENING IN CENTRAL IOWA. SHEAR PARAMETERS ARE VERY FAVORABLE. FINALLY...THE WEATHER PATTERN IS ON PAR FOR THE TIME OF YEAR. THERE HAVE BEEN NUMEROUS SEVERE WEATHER EVENTS IN CENTRAL IOWA BETWEEN MARCH 31ST AND APRIL 12TH OVER THE YEARS. COLD AIR WILL MOVE BACK IN THE WAKE OF THIS SYSTEM AND TUESDAY LOOKS DRY BUT COOLER AND BREEZY. WEDNESDAY THROUGH FRIDAY...ACTIVE PATTERN CONTINUES. MODELS ARE IN POOR AGREEMENT WITH THE DETAILS AT THIS RANGE. HOWEVER...IT APPEARS LIKELY THAT ANOTHER STORM SYSTEM WILL IMPACT THE MIDWEST LATE IN THE WEEK. CONFIDENCE CONCERNING THE FORECAST DETAILS ARE BELOW AVERAGE AT THAT POINT. && .AVIATION...28/18Z ISSUED AT 1246 PM CDT FRI MAR 28 2014 STRATUS WILL BE HANGING IN LONGER THAN PREVIOUSLY THOUGHT. I HAVE KEPT AN IFR FORECAST GOING INTO THE EVENING...UNTIL THE UPPER LEVEL SHORTWAVE PASSES AND SCOURS OUT SOME OF THE MOISTURE. CIGS WILL GRADUALLY IMPROVE THROUGH THE OVERNIGHT HOURS ALTHOUGH IF CLOUDS BREAK WE COULD SEE SOME MVFR FOG CONDITIONS FOR A COUPLE HOURS. AFT 14-15Z JUST SOME SCT CLOUDS. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...FAB LONG TERM...JOHNSON AVIATION...FAB
AREA FORECAST DISCUSSION
NWS TOPEKA KS
556 PM CDT Fri Mar 28 2014 ...AVIATION UPDATE... .SHORT TERM...(This Evening through Saturday) Issued at 342 PM CDT FRI MAR 28 2014 Center of upper wave moving across South Dakota today with another wave crossing Texas. Enough forcing and moisture for scattered very light precip across much of Kansas today. Light winds and little insolation keeping temps in the middle 40s at 20Z. Visible satellite showing additional precip attempting to form in southwest Nebraska and northwest Kansas in steep low level lapse rates just ahead of the trough axis. Should see back edge of precip exiting east central Kansas by sunset with clearing already occurring in central portions of the state. Any convective activity to the west would likely not arrive until after sunset, given its diurnal nature am not expecting much if anything to survive this far east. Clear skies and light winds in a reinforcing low level ridge overnight, but rather dry boundary layer should keep fog in check. Upper heights rise Saturday with surface ridge passing through in the daytime keeps winds on the lighter side again with modest warm air advection as high clouds slowly increase. Highs in the low to mid 60s remain on track. RH values dipping into the middle 20s will likely keep elevated fire danger conditions going for the west. .LONG TERM...(Saturday Night through Friday) Issued at 342 PM CDT FRI MAR 28 2014 Early on is the concern for winds on Sunday as 850 MB winds increase to 40 to 45 kts by the afternoon hours. Forecast soundings show mixing up to 825 MB with temperatures in the mid to upper 70s. Afternoon relative humidity expected near or below 30 percent and given the dry fuels expect high to very high fire danger on Sunday. Also winds will increase to near 25 mph with gusts as high as 40 mph not out of the question. Most likely will need a wind advisory for Sunday. Sunday night elevated showers and thunderstorms are possible across the CWA after midnight when the low level jet increases ahead of an approaching upper trough moving out of the Rockies. The trough moves northeast from southwest Kansas into south central Nebraska during the morning hours on Monday with a dry slot moving across eastern Kansas. Wrap around precipitation is possible to the north of the Nebraska border in the afternoon. A pacific cool front will move across the CWA during the day on Monday. Will leave a dry forecast for now, but this will need to be monitored. Tuesday night increasing moisture and instability is forecast across northern Kansas as the low level jet increases from the south. Good moisture fetch from the gulf into the Southern and Central Plains. Warm front sets up south of the CWA across southern Kansas with isentropic lift increasing northward over the CWA especially after midnight. Wednesday looking like a busy day with potential for severe thunderstorms across the CWA. Shear, instability and moisture coming together along with the warm front sliding northward into the CWA in the afternoon hours. Another Pacific front will move through Thursday as the upper low moves across the Central Plains. Kept chances of showers as instability shifts off to the east into the Mid Mississippi Valley by evening. There is uncertainty in the track of the upper low with the ECMWF further north and the GFS south across Kansas. This will have an impact on both temperatures and precipitation placement. Friday looking dry as the upper system is well east. Temperatures for much of next week will average near or below normal. && .AVIATION...(For the 00Z TAFs through 00Z Saturday Evening) Issued at 556 PM CDT FRI MAR 28 2014 With TOP reporting reduced VSBY for much of the day, am a little concerned for the development of ground fog since the boundary layer never really mixed out. RAP and NAM forecast soundings also suggest there could be some shallow fog. At this time will mention some MVFR VSBY at TOP overnight. MHK and FOE mixed out better through the afternoon so think boundary layer moisture may be more limited and fog potential is lower given some dry air advection through the night. Otherwise conditions should be fine with surface ridging over the area through the morning Saturday. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...65 LONG TERM...53 AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
226 PM EDT FRI MAR 28 2014 .UPDATE... ISSUED AT 210 PM EDT FRI MAR 28 2014 GRIDS WERE FRESHENED UP BASED ON THE LATEST OBSERVATION TRENDS. SHOWER ACTIVITY IS NEXT TO NIL ACROSS THE REGION IN ADVANCE OF THE COLD FRONT. THIS IS LIKELY DUE TO SOME MID LEVEL CAPPING AS SHORTWAVE MID LEVEL RIDGING BETWEEN THE DEPARTING SHORTWAVE AND THE NEXT SYSTEMS WORKS ACROSS THE OH VALLEY REGION. SHOWER ACTIVITY THIS AFTERNOON SHOULD BE MINIMAL...IF ANY AT ALL ACROSS THE REGION. AT THIS TIME...WE PLAN TO LET THE SLIGHT CHANCE POPS RIDE SINCE THE NAM AND GFS AS WELL AS THE HRRR STILL HAVE SOME CONVECTION LATER THIS AFTERNON AND INTO THE EVENING. UPDATE ISSUED AT 1120 AM EDT FRI MAR 28 2014 THE PREFRONTAL CONVECTION HAS EXITED TO THE SOUTH AND EAST...ALTHOUGH THE COLD FRONT IS ONLY MAKING SLOW SOUTHEAST PROGRESS AND IS NEAR OR JUST WEST OF THE INTERSTATE 65 CORRIDOR. A MID LEVEL SHORTWAVE OVER THE GREAT LAKES REGION IS EXITING TO THE NORTH AND EAST OF THE AREA. A RELATIVE LULL IN ACTIVITY IS ANTICIPATED BETWEEN THIS DEPARTING SHORTWAVE AND THE NEXT WAVE TO APPROACH THE AREA TONIGHT. THUS...POPS HAVE BEEN LOWERED TO SLIGHT CHANCE FOR THE REMAINDER OF THE DAY INTO THE EVENING. ALSO...HOURLY SKY...TEMPS AND DEWPOINTS HAVE BEEN FINE TUNED TO REFLECT RECENT OBSERVATIONS AS WELL AS SATELLITE AND RADAR IMAGERY. UPDATE ISSUED AT 800 AM EDT FRI MAR 28 2014 THE THUNDERSTORMS WITH THE COLD FRONT ARE FADING OUT NOW SO HAVE BACKED OFF OF THEM TO JUST AN ISOLATED MENTION IN THE GRIDS. HAVE TIMED THE CORE OF THE PCPN THROUGH THE AREA FROM WEST TO EAST FROM 12 TO 15Z. ALSO...FINE TUNED TEMPS AND DEWPOINTS THROUGH THE NEXT SEVERAL HOURS WITH THIS UPDATE PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 335 AM EDT FRI MAR 28 2014 06Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING THROUGH THE GREAT LAKES WITH A SHARP COLD FRONT ENTERING THE OHIO VALLEY. THIS BOUNDARY IS SHOWING UP WELL ON RADAR AS A THIN LINE OF SHOWERS AND THUNDERSTORMS DROPPING SOUTHEAST TOWARD KENTUCKY. SCATTERED TO NUMEROUS SHOWERS ARE FOUND OUT AHEAD OF THIS LINE THROUGH CENTRAL EASTERN KENTUCKY. THIS ADVANCE CONVECTION IS WORKING TO MOISTEN UP THE VERY DRY AIR OVER EAST KENTUCKY AND THUS FAR NOT AMOUNTING TO TOO MUCH ACCUMULATION. HAVE TIMED THE FRONT INTO EAST KENTUCKY AROUND 12Z AND THROUGH BY 15Z...HIGHLIGHTING THIS TIME FRAME WITH THE HIGHEST POPS AND BEST CHANCE FOR THUNDER. IN THE MEANTIME...GUSTY SHOWERS AND SPRINKLES WILL CONTINUE OVER THE CWA. AHEAD OF THE FRONT THE TEMPERATURES ARE REMAINING QUITE MILD WITH READINGS GENERALLY IN THE LOW TO MID 50S. DEWPOINTS VARY FROM THE LOWER 40S IN THE WEST TO AROUND 30 IN THE FAR EAST. OUTSIDE OF THE HIGHER GUSTS IN SHOWERS... WINDS ARE RUNNING FROM THE SOUTH TO SOUTHWEST AT 10 TO 15 MPH WITH GUSTS TO 25 MPH. HIGHER SUSTAINED SPEEDS AND GUSTS TO 35 MPH ARE STILL POSSIBLE WITH THE SHOWERS...PARTICULARLY OVER THE NORTHERN AND WESTERN PARTS OF THE CWA. THE MODELS ARE IN DECENT AGREEMENT ALOFT WITH THE SHALLOW TROUGH PASSING THROUGH THE GREAT LAKES THIS MORNING. THIS IS FOLLOWED BY SOUTHWEST FLOW AND AN AMPLIFYING TROUGH OVER THE CENTRAL PLAINS INTO TONIGHT. THIS NEXT TROUGH IMPRESSIVELY DEEPENS AS IT MOVES INTO THE AREA AND RIGHT OVER KENTUCKY ON SATURDAY. THIS FEATURE NEARLY CLOSES OFF AND IS SURPRISINGLY SIMILAR IN THE MODELS AT 00Z SUNDAY WITH THE GEM AND GFS THE STRONGEST. THE ECMWF AND NAM ARE A BIT WEAKER...BUT THE PATTERNS AND TIMING ALL MATCH UP WELL. GIVEN THIS...HAVE GONE WITH A GENERAL MODEL BLEND AND FOLLOW SPECIFICS FROM THE NAM12 AND GFS. SENSIBLE WEATHER WILL FEATURE A VERY ACTIVE AND CHANGEABLE SHORT TERM PORTION OF THE FORECAST. FOR STARTERS...SHOWERS AND A POSSIBLE THUNDERSTORM...WILL CROSS THROUGH ALL OF EAST KENTUCKY THIS MORNING AS A COLD FRONT MOVES THROUGH. LOOK FOR CLOUDY SKIES TO REMAIN ALONG WITH SOME LINGERING SHOWERS FOR THE AFTERNOON...ESPECIALLY OVER THE SOUTHEAST. THIS FRONT WILL SETTLE JUST SOUTH OF THE AREA THIS EVENING AND QUICKLY REACTIVATE OVER THE WEST BY MIDNIGHT. THIS NEXT WAVE... DRIVEN BY THE APPROACHING AND STRENGTHENING MID LEVEL TROUGH...WILL CONSOLIDATE OVER THE TENNESSEE VALLEY BY EARLY SATURDAY MORNING AND RETURN SHOWERS AND POSSIBLE THUNDERSTORMS TO EAST KENTUCKY. THE CENTER OF THIS LOW WILL PASS THROUGH FAR SOUTHEAST KENTUCKY DURING THE DAY AND START TO PULL IN COLDER AIR FROM THE NORTH. THERE IS STRONG MODEL SUPPORT FOR THE COLUMN OF AIR COOLING ENOUGH BY LATE AFTERNOON IN THE NORTHWEST PARTS OF THE CWA TO RESULT IN A CHANGEOVER TO SNOW. SFC TEMPERATURES WILL STAY UP WELL ABOVE FREEZING THROUGH 00Z SUNDAY SO ANY ACCUMULATIONS WILL HOLD OFF UNTIL LATER THAT NIGHT. FOR TEMPERATURES...WINDS...AND DEW POINTS USED THE BC/CONSSHORT AS A STARTING POINT THROUGH THE EARLY OVERNIGHT HOURS OF SATURDAY. AFTER THAT USED AN ADJUSTED VERSION OF THE RAW NAM FOR TEMPS AND THE BC/CONSALL FOR TD AND WINDS. AS FOR POPS...ENDED UP RATHER WET AND IN LINE WITH THE MOS GUIDANCE. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 330 AM EDT FRI MAR 28 2014 THE EXTENDED FORECAST PERIOD BEGINS ON SATURDAY NIGHT WITH A PROGRESSIVE AND ACTIVE PATTERN IN PLACE AS A STRONG SHORTWAVE IS MOVING THROUGH THE OH AND TN VALLEY AT THIS TIME AND MOVES UP THE EAST COAST BY SUNDAY NIGHT. AFTER THAT...MID LEVEL RIDGING CAUSES A FAST MOVING SHORT WAVE TO MOVE NORTHEAST INTO THE GREAT LAKES REGION AND INTO NEW ENGLAND BY TUESDAY. AFTER THIS...A BROAD CLOSED LOW CROSSES THE FRONT RANGE AND INTO THE CENTRAL PLAINS BY TUESDAY NIGHT AND INTO WEDNESDAY. THIS WAVE DEEPENS AS IT THEN MOVES INTO THE MS RIVER VALLEY ON THURSDAY. THE GFS AND EURO SEEM TO BE IN DECENT AGREEMENT WITH THIS PATTERN...ESPECIALLY WITH THE LOW TOWARDS THE END OF THE EXTENDED WHICH COULD BE A SIGNIFICANT EVENT. IN THE LOWER LEVELS FOR SATURDAY NIGHT...THE COLDER AIR FILTERING IN BEHIND THE FRONT THAT PASSED THROUGH ON SATURDAY WILL MAKE INTO THE AREA FAST ENOUGH FOR RAIN TO CHANGE TO SNOW. IN FACT...WITH THE SMALL LAYER OF DRIER AIR AT THE SURFACE FOR SOME WET BULBING...THE COLDER AIR NOT FAR OFF THE SURFACE...AND THE CONVECTIVE PROPERTIES OF THE SHOWERS...WILL NOT BE SURPRISED TO SEE SNOW AT 35 DEGREES AT THE SURFACE. WITH THE DEPTH OF THE MOIST LAYER AND THE OMEGA AVAILABLE...HAVE ALSO PUT IN SOME ACCUMULATING SNOW IN THE FORECAST WITH MAINLY THE BLUE GRASS AND THE HIGHER TERRAIN IN THE NORTH AND EAST. THE FRONT MOVING THROUGH ON TUESDAY LOOKS TO DRY OUT AS IT APPROACHES THE AREA. THE BEST DYNAMICS TAKE A FARTHER TRACK NORTH AND HAVE LEFT SLIGHT CHANCE POPS NORTH OF THE FORECAST AREA. HOWEVER...WILL NOT BE SURPRISED TO SEE SOME SPRINKLES POP UP TUESDAY AFTERNOON. ANY HINT THAT THE DEVELOPING SHOWERS WILL NOT SHEAR OUT AND SOME ADDITIONAL MOISTURE AVAILABLE...THE CHANCE IS THERE FOR SOME SHOWERS AND AN ISOLATED THUNDERSTORM. THERE IS A GOOD BIT OF SURFACE INSTABILITY TUESDAY AFTERNOON. FOR NOW...WILL KEEP THIS PERIOD DRY. WITH MOST LIKELY A DRY PERIOD CONTINUING INTO WEDNESDAY...THE SET UP TOWARDS THE END OF THE EXTENDED WILL CHANGE THIS DRY PATTERN. SURFACE HIGH PRESSURE SETS UP OVER THE SOUTHEAST AND PROVIDING WARM MOIST SOUTHERLY FLOW INTO THE OH VALLEY AHEAD OF THE NEXT APPROACHING POTENT SYSTEM WILL BRING SHOWERS AND THUNDERSTORMS INTO THE AREA LATE WEDNESDAY AND THROUGH THE REST OF THE EXTENDED. THIS SET UP WILL BE ONE TO WATCH FOR HOW IT DEVELOPS. A LOT CAN CHANGE IN THE MODELS BETWEEN NOW AND THEN BUT THE POTENTIAL FOR SEVERE WEATHER IS PRESENT WITH THIS SET UP. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 210 PM EDT FRI MAR 28 2014 A COLD FRONT HAS BEGUN TO STALL ACROSS THE OH VALLEY REGION AS THE FIRST SFC LOW AND ASSOCIATED MID LEVEL DISTURBANCE DEPART AND SFC LOW PRESSURE BEGINS TO ORGANIZE OVER THE SOUTHERN PLAINS. THIS NEXT SFC LOW WILL TRACK ACROSS THE AREA LATE TONIGHT AND INTO SAT. SOME LOCATIONS SHOULD IMPROVE TO VFR FOR A WHILE OVER THE FIRST 6 TO 9 HOURS OF THE PERIOD IN BETWEEN SYSTEMS. CLOUDS WILL REMAIN...JUST ABOVE THE MVFR VFR BREAK IN LOCATIONS THAT DO IMPROVE TO VFR. THIS NEXT LOW WILL BRING RENEWED CHANCES FOR SHOWERS AND POSSIBLY ISOLATED TSRA AS WELL AS ANOTHER LOWERING OF CONDITIONS BACK TO MVFR BETWEEN 8Z AND 14Z. THIS WILL BE AFTER && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...SHALLENBERGER AVIATION...JP
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1229 PM CDT FRI MAR 28 2014 .AVIATION UPDATE...REGARDING 18Z TAF ISSUANCE. MVFR AND IFR CEILINGS CAN BE EXPECTED TODAY AS A MOIST SOUTHERLY FLOW CONTINUES. A FEW SHOWERS WILL BE POSSIBLE DURING THE AFTERNOON...WITH INCREASING SHOWERS ALONG WITH THUNDERSTORMS INCOMING FROM THE WEST GOING INTO THE EVENING HOURS. THIS ALONG AND AHEAD OF OUR NEXT FRONTAL PASSAGE. CURRENTLY CARRYING PREVAILING FOR THUNDER AT AEX WHERE LIFT WILL BE SOMEWHAT STRONGER FOR CONVECTION...AND TEMPO GROUPS AT OUR SOUTHERN TERMINALS. COULD NOT RULE OUT SOME STRONG OR EVEN SEVERE THUNDERSTORMS...AGAIN WITH BEST CHANCES AT AEX. OTHERWISE...RAINS WILL TAPER OFF WITH THE FRONTAL PASSAGE...BUT EXPECTING IFR CEILINGS AND SOME BR TO HOLD POST-FRONTAL AS DRIER AIR SURFACE AIR WILL BE SLOW TO FILTER IN. EXPECTING CLEARING SKIES WEST TO EAST POST-SUNRISE SATURDAY. && MARCOTTE && .PREV DISCUSSION... /ISSUED 1030 AM CDT FRI MAR 28 2014/ UPDATE... ADJUSTED THE POPS DOWNWARD A LITTLE FOR MOST PLACES FOR THE REMAINDER OF THE MORNING AND AFTERNOON. LOOKS LIKE CAP SHOULD HOLD ENOUGH THAT JUST WIDELY SCATTERED SHOWERS...MAINLY LIGHT...UNDER THE CAP WILL BE ALL THAT CAN GET GOING. AFTER 21Z...4 PM...UPPER LEVEL SUPPORT WILL BE MOVING TOWARD THE REGION...THIS MAY ALLOW FOR SOME STRONGER SHOWERS AND STORMS TO DEVELOP OVER WESTERN PORTIONS OF SOUTHEAST TEXAS...TYLER AND HARDIN COUNTIES...SO HAVE KEPT HIGHER POPS IN THIS AREA...WITH THE MENTION OF POSSIBLE SEVERE. ALSO...VISIBILITIES HAVE BEEN IMPROVING OVER THE MARINE AREAS A LITTLE QUICKER THAN PREVIOUSLY EXPECTED...WITH VISIBILITIES AT CAMERON UP TO 2 MILES...AND PLATFORMS SOUTHEAST OF GALVESTON AND SOUTH OF MARSH ISLAND ALSO AROUND 2 MILES. EXPECT A LITTLE MORE IMPROVEMENT OVER THE NEXT COUPLE OF HOURS AS WARMING PROVIDES ENOUGH INSTABILITY TO HELP BRIEFLY LIFT THE FOG OR MAKE IT MORE PATCHY IN NATURE. THEREFORE...WILL HAVE THE MARINE DENSE FOG ADVISORY EXPIRE AT NOON TIME. RUA PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 28 2014/ AVIATION...LIFR AND IFR CEILINGS WILL CONTINUE THROUGH THE MOST OF THE MORNING ALONG WITH REDUCED VIS IN BR AND -RA. CONDITIONS WILL GRADUALLY IMPROVE FROM LATE MORNING INTO THE AFTERNOON, HOWEVER ADDITIONAL RAIN AND THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON AND EVENING. THIS WILL REDUCE CEILINGS AND VIS ONCE AGAIN. RAIN CHANCES WILL DECREASE PAST MIDNIGHT WITH FG DEVELOPING TOWARD SAT MORNING. WINDS WILL BE SE TO SW TODAY AT 12 KTS OR LESS OUTSIDE OF STORMS. WINDS MAY BECOME GUSTY AND ERRATIC IN OR NEAR STORMS. PREV DISCUSSION... /ISSUED 531 AM CDT FRI MAR 28 2014/ DISCUSSION... SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING EAST OF THE FOUR CORNERS. THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO. DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL WATERS. THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET. 13 MARINE... SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING TO START THE WORK WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 62 76 49 72 50 / 60 10 10 10 10 KBPT 62 78 52 73 53 / 50 10 10 10 10 KAEX 57 72 44 73 46 / 60 10 10 10 10 KLFT 63 74 49 73 49 / 60 10 10 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1030 AM CDT FRI MAR 28 2014 .UPDATE... ADJUSTED THE POPS DOWNWARD A LITTLE FOR MOST PLACES FOR THE REMAINDER OF THE MORNING AND AFTERNOON. LOOKS LIKE CAP SHOULD HOLD ENOUGH THAT JUST WIDELY SCATTERED SHOWERS...MAINLY LIGHT...UNDER THE CAP WILL BE ALL THAT CAN GET GOING. AFTER 21Z...4 PM...UPPER LEVEL SUPPORT WILL BE MOVING TOWARD THE REGION...THIS MAY ALLOW FOR SOME STRONGER SHOWERS AND STORMS TO DEVELOP OVER WESTERN PORTIONS OF SOUTHEAST TEXAS...TYLER AND HARDIN COUNTIES...SO HAVE KEPT HIGHER POPS IN THIS AREA...WITH THE MENTION OF POSSIBLE SEVERE. ALSO...VISIBILITIES HAVE BEEN IMPROVING OVER THE MARINE AREAS A LITTLE QUICKER THAN PREVIOUSLY EXPECTED...WITH VISIBILITIES AT CAMERON UP TO 2 MILES...AND PLATFORMS SOUTHEAST OF GALVESTON AND SOUTH OF MARSH ISLAND ALSO AROUND 2 MILES. EXPECT A LITTLE MORE IMPROVEMENT OVER THE NEXT COUPLE OF HOURS AS WARMING PROVIDES ENOUGH INSTABILITY TO HELP BRIEFLY LIFT THE FOG OR MAKE IT MORE PATCHY IN NATURE. THEREFORE...WILL HAVE THE MARINE DENSE FOG ADVISORY EXPIRE AT NOON TIME. RUA && .PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAR 28 2014/ AVIATION...LIFR AND IFR CEILINGS WILL CONTINUE THROUGH THE MOST OF THE MORNING ALONG WITH REDUCED VIS IN BR AND -RA. CONDITIONS WILL GRADUALLY IMPROVE FROM LATE MORNING INTO THE AFTERNOON, HOWEVER ADDITIONAL RAIN AND THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON AND EVENING. THIS WILL REDUCE CEILINGS AND VIS ONCE AGAIN. RAIN CHANCES WILL DECREASE PAST MIDNIGHT WITH FG DEVELOPING TOWARD SAT MORNING. WINDS WILL BE SE TO SW TODAY AT 12 KTS OR LESS OUTSIDE OF STORMS. WINDS MAY BECOME GUSTY AND ERRATIC IN OR NEAR STORMS. PREV DISCUSSION... /ISSUED 531 AM CDT FRI MAR 28 2014/ DISCUSSION... SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING EAST OF THE FOUR CORNERS. THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO. DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL WATERS. THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET. 13 MARINE... SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING TO START THE WORK WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 78 62 76 49 72 / 30 60 10 10 10 KBPT 77 62 78 52 73 / 30 50 10 10 10 KAEX 80 57 72 44 73 / 30 60 10 10 10 KLFT 79 63 74 49 73 / 30 60 10 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR THE FOLLOWING ZONES: CALCASIEU LAKE...COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM... SABINE LAKE...VERMILION BAY. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
638 AM CDT FRI MAR 28 2014 .AVIATION...LIFR AND IFR CEILINGS WILL CONTINUE THROUGH THE MOST OF THE MORNING ALONG WITH REDUCED VIS IN BR AND -RA. CONDITIONS WILL GRADUALLY IMPROVE FROM LATE MORNING INTO THE AFTERNOON, HOWEVER ADDITIONAL RAIN AND THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON AND EVENING. THIS WILL REDUCE CEILINGS AND VIS ONCE AGAIN. RAIN CHANCES WILL DECREASE PAST MIDNIGHT WITH FG DEVELOPING TOWARD SAT MORNING. WINDS WILL BE SE TO SW TODAY AT 12 KTS OR LESS OUTSIDE OF STORMS. WINDS MAY BECOME GUSTY AND ERRATIC IN OR NEAR STORMS. && .PREV DISCUSSION... /ISSUED 531 AM CDT FRI MAR 28 2014/ DISCUSSION... SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING EAST OF THE FOUR CORNERS. THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO. DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL WATERS. THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET. 13 MARINE... SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING TO START THE WORK WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 77 62 76 49 72 / 30 60 10 10 10 KBPT 79 62 78 52 73 / 30 50 10 10 10 KAEX 78 57 72 44 73 / 40 60 10 10 10 KLFT 78 63 74 49 73 / 50 60 10 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...DENSE FOG ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: CALCASIEU LAKE...COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM... SABINE LAKE...VERMILION BAY. && FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV WWW.TWITTER.COM/NWSLAKECHARLES WWW.YOUTUBE.COM/NWSLAKECHARLES && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
531 AM CDT FRI MAR 28 2014 .DISCUSSION... SHOWERS AND THUNDERSTORMS CONTINUE OVER MAINLY EAST CENTRAL LOUISIANA THIS MORNING...GENERALLY WITHIN AREA OF ENHANCED LOW LEVEL MSTR INFLUX/CONVERGENCE AND BENEATH DIVERGENCE ALOFT ENHANCED BY COUPLED JET STRUCTURE BETWEEN SUB-TROPICAL JET AND JET MAX ASSOCIATED WITH SHORTWAVE TROF LIFTING THROUGH THE UPPER MIDWEST. UPSTREAM WATER VAPOR IMAGERY CONTINUES TO DEPICT AN ACTIVE SUB-TROPICAL JET...WITH ANOTHER SHORTWAVE TROF JUST PASSING EAST OF THE FOUR CORNERS. THE ONGOING ACTIVITY IS EXPECTED TO GENERALLY SHIFT EASTWARD THIS MORNING...WITH A GENERAL LULL IN ACTIVITY EXPECTED UNTIL THE APPROACH OF THIS UPSTREAM SHORTWAVE LATER THIS AFTERNOON. HRRR AND OTHER MESOSCALE MODELS INDICATE CONVECTION INITIATING OVER CENTRAL/EAST TEXAS EARLY TO MID AFTERNOON...WITH SUBSEQUENT DOWNSTREAM MOVEMENT/DEVELOPMENT ACROSS THE FORECAST AREA THIS EVENING. THE MARINE LAYER MAY PROVE DETRIMENTAL OVER THE COASTAL COUNTIES/PARISHES...BUT INSTABILITY IS OVERALL PROGGED TO BE GREATER THAN IT WAS ON THURSDAY...WITH THE ADDITION OF SFC FEATURES...LIKE THE APPROACHING CDFNT...TO BETTER FOCUS DEVELOPMENT. SPC HAS ENTIRE AREA OUTLINE IN A SLIGHT RISK...WITH LARGE HAIL/DAMAGING WINDS THE PRIMARY HAZARDS. LOW LEVEL SHEAR/HELICITY...WHILE NOT PRECLUDING TORNADOES...SUGGESTS THE RISK IS SUBORDINATE TO THE OTHER TWO. DECREASING WINDS HAVE SUBSEQUENTLY RESULTED IN DECREASING VSBYS OVER THE COASTAL WATERS AS WELL AS INLAND. SUFFICIENT TURBULENT MIXING WILL LIKELY PREVENT INLAND VSBYS FROM REACHING DENSE FOG CRITERIA...BUT REFER TO THE MARINE DISCUSSION BELOW FOR THE COASTAL WATERS. THE CDFNT IS PROGGED TO SWEEP THROUGH THE REGION LATE TONIGHT...WITH COOLER AND DRIER AIR GIVING WAY TO A PLEASANT WEEKEND. RAIN CHANCES LOOK TO RETURN FOR THE MID TO LATTER PART OF THE WEEK AMID THE RETURN OF A WAA REGIME AND ACTIVE SUB-TROPICAL JET. 13 && .MARINE... SOUTH WINDS HAVE STEADILY DECREASED EARLY THIS MORNING...WHICH IS PERMITTING A SLOWER TRANSPORT OF MOISTURE LADEN AIR OVER RELATIVELY COOLER SHELF WATERS. THE RESULT HAS BEEN A STEADY DECREASE IN VISIBILITIES SEEN AT OFFSHORE AND COASTAL REPORTING SITES. WITH THIS PATTERN EXPECTED TO REMAIN IN PLACE UNTIL A COLD FRONT PASSES EARLY SATURDAY...CONDITIONS WILL CONTINUE TO SUPPORT MARINE FOG FORMATION. A MARINE FOG ADVISORY HAS BEEN ISSUED...AND MAY NEED TO BE EXTENDED BEYOND THE CURRENT EXPIRATION TIME OF 7 PM CDT. GOOD CHANCES OF SHOWERS AND THUNDERSTORMS ARE EXPECTED UNTIL THIS COLD FRONT MOVES THROUGH THE REGION LATE FRIDAY NIGHT INTO EARLY SATURDAY. A MODEST OFFSHORE FLOW IS EXPECTED OVER THE WEEKEND IN THE WAKE OF THE FRONT...WITH SOUTHERLY WINDS RETURNING TO START THE WORK WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 77 62 76 49 / 30 60 10 10 KBPT 79 62 78 52 / 30 50 10 10 KAEX 78 57 72 44 / 40 60 10 10 KLFT 78 63 74 49 / 50 60 10 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...DENSE FOG ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CALCASIEU LAKE-COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM-COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM-COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM-SABINE LAKE-VERMILION BAY. && $$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1026 PM EDT SAT MAR 29 2014 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL TRACK SLOWLY EAST... SOUTH OF THE AREA TONIGHT INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH SUNDAY NIGHT/... 945 PM UPDATE: ONLY CHG THIS UPDATE WAS FCST HRLY TEMPS THRU THE OVRNGT BASED ON 9 PM OBSVD TEMPS. NO CHGS WERE MADE TO FCST OVRNGT LOWS OR THE REST OF THE NEAR TERM FCST ELEMENTS THIS UPDATE WITH THE GOING FCST STILL LOOKING TO BE ON TRACK. 725 PM UPDATE: IN THE IMMEDIATE TERM...ADJUSTMENTS WERE MADE TO OVRNGT CLD CVR AND FCST HRLY TEMPS BASED ON LATEST SAT IMAGERY AND 6 TO 7 PM OBSVD TEMPS. THEN SOME MINOR CHGS WERE MADE TO 6 HRLY SNFLS SPCLY SUN INTO SUN EVE...SO ACCUMULATIONS REALISTICALLY MATCHED FCST PRECIP TYPES. THE ONLY SIG CHG WAS A LOWERING OF SN/PL TOTALS IN THE INTERIOR DOWNEAST WNTR WX ADV AREA AND A NEAR ELIMINATION OF SN/PL ACCUMULATION MENTION ALG THE IMMEDIATE DOWNEAST COAST...WHERE PREDOMINATELY NEARLY ALL RN IS FCST FOR THIS EVENT. ORGNL DISC: AT THE START OF THE PERIOD THE MAJOR MODELS ARE SHOWING THE NEXT SYSTEM TO AFFECT OUR AREA CENTERED OVER THE CNTRL PORTIONS OF THE NC/VA BORDER...WITH A WARM FRONT EXTENDING NORTH TO THE SW COAST OF MAINE. THE MODEL INDICATE THAT THE LOW IS STILL DYNAMIC AT THIS POINT...BUT SHOWING THAT THE UPPER LEVEL LOW IS STARTING TO BECOME VERTICALLY STACKED WITH THE SURFACE LOW...THE BEGINNING PROCESS OF BECOME COLD CORE. BY MRNG THE LOW MOVES NE TO THE NJ COAST...PRECIP SPREADS ACROSS ERN MAINE INTO NRN MAINE. PCPN WILL BE SNOW...WITH SLEET AND FREEZING RAIN MIXED IN ACROSS THE INTERIOR DOWNEAST AND EAST CNTRL MAINE. AT THIS TIME ALL MODELS SHOWING A CLOSED LOW AT 500MB AND THE SFC LOW NEARLY VERTICALLY STACKED. BY THE END OF THE PERIOD...THE BULK OF THE PCPN MOVES EAST INTO NEW BRUNSWICK...THE LOW DRIFTS NORTH ALONG THE NJ COAST TO JUST SOUTH OF LONG ISLAND. THE UPPER LOW AND SFC LOW WILL BE VERTICALLY STACKED. THE GFS...GEM...AND ECMWF SHOW A NEW LOW IN THE ERN GULF OF MAINE THAT WILL BECOME THE NEW PRIMARY LOW FOR THIS SYSTEM AS IT TRACKS TOWARD NEW BRUNSWICK. LOADED THE HRRR MIN TEMP FOR THE OVRNGT...GEM MAX TEMP FOR TOMORROW. INTERPOLATED FROM MIN TO MAX FOR HRLY TEMPS. USED A BLEND OF NAM/GFS/GEM/ECMWF FOR HRLY DP/SKY/WND/POP. ADDED 15 PERCENT TO WINDS FOR GUSTS OVER LAND...25 PERCENT OVER WATERS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... A VERTICALLY STACKED SURFACE/UPPER LOW WILL BEGIN TO MOVE SLOWLY NORTHEAST SUNDAY NIGHT. A NEARLY STATIONARY FRONTAL BOUNDARY WILL EXTEND NORTHEAST FROM THE SURFACE LOW. ISENTROPIC LIFT AND OVERRUNNING IN THE VICINITY OF THE FRONT WILL SUPPORT PRECIPITATION ACROSS THE FORECAST AREA SUNDAY NIGHT. HOWEVER...THE PROXIMITY OF THE FRONT TO THE COAST REMAINS UNCERTAIN. HAVE BASED THE FORECAST ON A SLOWER MOVEMENT OF THE SURFACE LOW AND THE FRONT REMAINING CLOSER TO THE COAST WHICH WILL KEEP MORE EXTENSIVE PRECIPITATION ACROSS THE FORECAST AREA. HIGH PRESSURE NORTH OF MAINE WILL CONTINUE TO PROVIDE LOW LEVEL COLD AIR ACROSS THE FORECAST AREA SUNDAY NIGHT INTO MONDAY. HOWEVER...WARMER AIR ALOFT WILL KEEP A WINTRY MIX ACROSS MUCH OF THE FORECAST AREA SUNDAY NIGHT. A WINTRY MIX WILL PERSIST ACROSS NORTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA SUNDAY NIGHT...WITH RAIN TRANSITIONING TO A WINTRY MIX ACROSS DOWNEAST AREAS. WINTER STORM WARNINGS WILL REMAIN IN EFFECT ACROSS NORTHERN AREAS SUNDAY NIGHT...WITH WINTER WEATHER ADVISORIES ACROSS CENTRAL AREAS AND INTERIOR DOWNEAST PORTIONS OF THE FORECAST AREA. HAVE HELD WITH THE SLOWER MOVEMENT OF THE SYSTEM MONDAY...WHICH WILL KEEP LIGHT PRECIPITATION ACROSS THE FORECAST AREA. ACROSS NORTHERN AREAS EXPECT EXPECT A LIGHT WINTRY MIX...WITH A WINTRY MIX TRANSITIONING TO RAIN ACROSS CENTRAL AND DOWNEAST AREAS. THE SURFACE/UPPER LOW WILL MOVE EAST MONDAY NIGHT WHILE HIGH PRESSURE SLOWLY BUILDS SOUTH WITH DECREASING RAIN/SNOW SHOWER CHANCES ACROSS THE FORECAST AREA. A SLIGHT CHANCE OF SHOWERS COULD PERSIST DOWNEAST TUESDAY WITH THE EXITING LOW WHILE HIGH PRESSURE BUILDS ACROSS NORTHERN MAINE. TEMPERATURES WILL BE AT SLIGHTLY BELOW NORMAL LEVELS MONDAY/TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... LOW PRESSURE WILL BE MOVING AWAY TUESDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. THIS WILL BRING DRY AND RELATIVELY MILD WEATHER TUESDAY NIGHT INTO WEDNESDAY. A WEAK TROUGH MAY MOVE THROUGH ON THURSDAY BRINGING SOME CLOUDS AND PERHAPS LIGHT SHOWERS. OTHERWISE, THE DAY SHOULD REMAIN MOSTLY CLOUDY. HIGH PRESSURE SHOULD THEN BUILD IN BRINGING DRIER AND SEASONABLY MILD CONDITIONS ON FRIDAY. GOING INTO THE WEEKEND, LOTS OF UNCERTAINTY REGARDING WHETHER OR NOT A BLOCKING RIDGE OVER EASTERN CANADA CAN MAINTAIN THE DRY WEATHER. THE GFS KEEPS CONDITIONS DRY WHILE THE ECMWF BRINGS A TROUGH OF LOW PRESSURE THROUGH WITH A CHANCE FOR SOME RAIN OR SNOW SHOWERS. IN THE FORECAST WILL HAVE LOW CHANCE FOR RAIN OR SNOW SHOWERS NEXT WEEKEND. CURRENTLY DOES NOT LOOK LIKE ANY MAJOR STORMS ARE EXPECTED THROUGH NEXT WEEKEND, AND TEMPERATURES WILL BE NEAR NORMAL WHICH WILL BE CONSIDERABLY MILDER THAN THE VERY COLD CONDITIONS WE HAVE HAD IN MARCH. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... NEAR TERM: DETERIORATING CONDITIONS SOUTH TO NORTH AS THE LOW MOVES INTO THE AREA. MVFR CONDITIONS BHB...ALL OTHER SITES VFR TO START THE PERIOD THIS EVENING. BY 9PM IFR CONDITIONS BHB IN RAIN...BGR RAIN BCMG MXD. IFR CONDITIONS MOVE INTO HUL...PQI...CAR...FVE AFT 3AM...PCPN SNOW BCMG MXD AT HUL TOMORROW AFTN. IFR CONDITION WILL REMAIN ACROSS THE AREA THROUGH THE END OF THE PERIOD. PCPN TYPE SN FOR FVE...SN MAY MIX WITH PL BRIEFLY IN AFTN IN PQI AND CAR. SHORT TERM: IFR/LIFR CONDITIONS ARE EXPECTED ACROSS THE REGION SUNDAY NIGHT INTO EARLY MONDAY...WITH MVFR/IFR CONDITIONS LATER MONDAY. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE REGION MONDAY NIGHT. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS DOWNEAST AREAS EARLY TUESDAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED ACROSS THE REGION TUESDAY. VFR CONDITIONS ARE EXPECTED ACROSS THE REGION WEDNESDAY. VFR CONDITIONS ARE EXPECTED ACROSS NORTHERN AREAS THURSDAY...WITH OCCASIONAL MVFR CONDITIONS POSSIBLE DOWNEAST. && .MARINE... NEAR TERM: 1000 PM UPDATE...WITH NO INTERIM SCA HDLN AND WINDS FCST TO REACH LOW END GALE FORCE GUSTS IN ABOUT 12 TO 15 HRS...WE THOUGHT IT BEST TO CONVERT THE GALE WATCH TO A WARNING FOR THE SAME PD OF TM ADVERTISED IN THE WATCH...NAMELY SUN AFTN THRU LATE MON NGT...WITH THE 18Z GFS ADVERTISING GALE FORCE WIND GUSTS FOR APPROXIMATELY THIS TM PD. ORGNL DISC...THE LOW WILL TRANSIT SLOWLY SOUTH OF OF THE GULF OF MAINE. TODAYS TRACK IS FARTHER SOUTH THAN WAS PREVIOUS FORECASTED. WINDS STILL CALL FOR MARGINAL GALE FORCE WINDS FOR TOMORROW. WILL CONTINUE THE GALE WATCH. SHORT TERM: MARGINAL GALE CONDITIONS ARE POSSIBLE SUNDAY NIGHT INTO EARLY MONDAY NIGHT WHICH COULD REQUIRE GALE WARNINGS. VISIBILITIES WILL BE REDUCED IN RAIN SUNDAY NIGHT INTO EARLY MONDAY NIGHT...WITH LINGERING RAIN/SNOW SHOWERS POSSIBLE LATER MONDAY NIGHT INTO TUESDAY. && .HYDROLOGY... A FLOOD WATCH CONTINUES FOR DOWNEAST MAINE SUNDAY THROUGH MONDAY AFTERNOON. THE PRECIPITATION ASSOCIATED WITH THE UPCOMING STORM WILL LIKELY FALL MAINLY AS RAIN OR FREEZING RAIN IN THESE AREAS, ESPECIALLY ALONG THE COAST. TOTAL LIQUID PRECIPITATION AMOUNTS OF UP TO 3 INCHES ARE EXPECTED. IN ADDITION TO THIS RAIN...TEMPERATURES WILL REMAIN NEAR OR ABOVE FREEZING THROUGH SUNDAY ADDING SNOWMELT TO THE EQUATION. THE SNOWPACK IN THESE AREAS IS HIGHLY VARIABLE, RANGING FROM AROUND 6 INCHES ALONG THE COAST TO 2 FEET OR MORE IN THE INTERIOR. THERE IS 2 TO 4 INCHES OF WATER CONTAINED IN THE PACK ALONG THE COAST WITH 6 TO 8 INCHES FURTHER INLAND. WHILE THE DEEPER SNOW WILL BE ABLE TO ABSORB SOME OF THE RAIN...MUCH OF IT WILL BECOME RUNOFF IN ADDITION TO THE SNOWMELT. THIS MEANS DOWNEAST AREAS COULD POTENTIALLY SEE 4 INCHES OR MORE OF TOTAL RUNOFF. RIVERS WILL LIKELY RISE SUBSTANTIALLY AND POTENTIALLY CAUSE RIVER ICE TO BREAK UP...ESPECIALLY IN THOSE PLACES WHERE THE ICE COMPLETELY FLUSHED OUT IN JANUARY (MEANING THE ICE THERE NOW IS RELATIVELY WEAK). FOR THOSE RIVER STRETCHES THAT ARE ICE FREE...ICE COVER UPSTREAM MAY BREAK UP AND COLLECT DOWNSTREAM. IN ADDITION TO THE POTENTIAL FOR ICE JAMS, THIS AMOUNT OF RAINFALL AND RUNOFF WILL LIKELY LEAD TO PONDING OF WATER ON ROADWAYS AND MINOR FLOODING OF LOW-LYING POOR DRAINAGE AREAS. IN ADDITION, TIDAL LOCATIONS SUCH AS BANGOR WILL HAVE TO BE WATCHED CLOSELY AROUND THE TIME OF HIGH TIDE. THE CURRENT OFFICIAL NATIONAL WEATHER SERVICE FORECAST FOR THE PENOBSCOT RIVER AT BANGOR BRINGS THE GAGE WITHIN 1 FOOT OF FLOOD STAGE WITH HIGH TIDE SUNDAY MORNING. PERSONS WITH INTERESTS ALONG WATERWAYS OR IN FLOOD-PRONE LOCATIONS ACROSS HANCOCK...WASHINGTON AND SOUTHERN PENOBSCOT COUNTIES SHOULD STAY TUNED FOR ADDITIONAL INFORMATION ON THIS SYSTEM. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER STORM WARNING FROM 6 AM SUNDAY TO 8 AM EDT MONDAY FOR MEZ001-002. WINTER STORM WARNING FROM 2 AM SUNDAY TO 8 AM EDT MONDAY FOR MEZ003>006-010. WINTER WEATHER ADVISORY FROM 2 AM SUNDAY TO 8 AM EDT MONDAY FOR MEZ011-015>017-031-032. FLOOD WATCH FROM 8 AM EDT SUNDAY THROUGH MONDAY AFTERNOON FOR MEZ015>017-029-030. GALE WARNING FROM NOON SUNDAY TO 4 AM EDT TUESDAY FOR MEZ029. MARINE...GALE WARNING FROM NOON SUNDAY TO 4 AM EDT TUESDAY FOR ANZ050>052. && $$ NEAR TERM...VJN SHORT TERM...NORCROSS LONG TERM...BLOOMER AVIATION...VJN/NORCROSS MARINE...VJN/NORCROSS HYDROLOGY...NORTON
AREA FORECAST DISCUSSION
NWS CARIBOU ME
753 PM EDT SAT MAR 29 2014 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL TRACK SLOWLY EAST... SOUTH OF THE AREA TONIGHT INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH SUNDAY NIGHT/... 725 PM UPDATE: IN THE IMMEDIATE TERM...ADJUSTMENTS WERE MADE TO OVRNGT CLD CVR AND FCST HRLY TEMPS BASED ON LATEST SAT IMAGERY AND 6 TO 7 PM OBSVD TEMPS. THEN SOME MINOR CHGS WERE MADE TO 6 HRLY SNFLS SPCLY SUN INTO SUN EVE...SO ACCUMULATIONS REALISTICALLY MATCHED FCST PRECIP TYPES. THE ONLY SIG CHG WAS A LOWERING OF SN/PL TOTALS IN THE INTERIOR DOWNEAST WNTR WX ADV AREA AND A NEAR ELIMINATION OF SN/PL ACCUMULATION MENTION ALG THE IMMEDIATE DOWNEAST COAST...WHERE PREDOMINATELY NEARLY ALL RN IS FCST FOR THIS EVENT. ORGNL DISC: AT THE START OF THE PERIOD THE MAJOR MODELS ARE SHOWING THE NEXT SYSTEM TO AFFECT OUR AREA CENTERED OVER THE CNTRL PORTIONS OF THE NC/VA BORDER...WITH A WARM FRONT EXTENDING NORTH TO THE SW COAST OF MAINE. THE MODEL INDICATE THAT THE LOW IS STILL DYNAMIC AT THIS POINT...BUT SHOWING THAT THE UPPER LEVEL LOW IS STARTING TO BECOME VERTICALLY STACKED WITH THE SURFACE LOW...THE BEGINNING PROCESS OF BECOME COLD CORE. BY MRNG THE LOW MOVES NE TO THE NJ COAST...PRECIP SPREADS ACROSS ERN MAINE INTO NRN MAINE. PCPN WILL BE SNOW...WITH SLEET AND FREEZING RAIN MIXED IN ACROSS THE INTERIOR DOWNEAST AND EAST CNTRL MAINE. AT THIS TIME ALL MODELS SHOWING A CLOSED LOW AT 500MB AND THE SFC LOW NEARLY VERTICALLY STACKED. BY THE END OF THE PERIOD...THE BULK OF THE PCPN MOVES EAST INTO NEW BRUNSWICK...THE LOW DRIFTS NORTH ALONG THE NJ COAST TO JUST SOUTH OF LONG ISLAND. THE UPPER LOW AND SFC LOW WILL BE VERTICALLY STACKED. THE GFS...GEM...AND ECMWF SHOW A NEW LOW IN THE ERN GULF OF MAINE THAT WILL BECOME THE NEW PRIMARY LOW FOR THIS SYSTEM AS IT TRACKS TOWARD NEW BRUNSWICK. LOADED THE HRRR MIN TEMP FOR THE OVRNGT...GEM MAX TEMP FOR TOMORROW. INTERPOLATED FROM MIN TO MAX FOR HRLY TEMPS. USED A BLEND OF NAM/GFS/GEM/ECMWF FOR HRLY DP/SKY/WND/POP. ADDED 15 PERCENT TO WINDS FOR GUSTS OVER LAND...25 PERCENT OVER WATERS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... A VERTICALLY STACKED SURFACE/UPPER LOW WILL BEGIN TO MOVE SLOWLY NORTHEAST SUNDAY NIGHT. A NEARLY STATIONARY FRONTAL BOUNDARY WILL EXTEND NORTHEAST FROM THE SURFACE LOW. ISENTROPIC LIFT AND OVERRUNNING IN THE VICINITY OF THE FRONT WILL SUPPORT PRECIPITATION ACROSS THE FORECAST AREA SUNDAY NIGHT. HOWEVER...THE PROXIMITY OF THE FRONT TO THE COAST REMAINS UNCERTAIN. HAVE BASED THE FORECAST ON A SLOWER MOVEMENT OF THE SURFACE LOW AND THE FRONT REMAINING CLOSER TO THE COAST WHICH WILL KEEP MORE EXTENSIVE PRECIPITATION ACROSS THE FORECAST AREA. HIGH PRESSURE NORTH OF MAINE WILL CONTINUE TO PROVIDE LOW LEVEL COLD AIR ACROSS THE FORECAST AREA SUNDAY NIGHT INTO MONDAY. HOWEVER...WARMER AIR ALOFT WILL KEEP A WINTRY MIX ACROSS MUCH OF THE FORECAST AREA SUNDAY NIGHT. A WINTRY MIX WILL PERSIST ACROSS NORTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA SUNDAY NIGHT...WITH RAIN TRANSITIONING TO A WINTRY MIX ACROSS DOWNEAST AREAS. WINTER STORM WARNINGS WILL REMAIN IN EFFECT ACROSS NORTHERN AREAS SUNDAY NIGHT...WITH WINTER WEATHER ADVISORIES ACROSS CENTRAL AREAS AND INTERIOR DOWNEAST PORTIONS OF THE FORECAST AREA. HAVE HELD WITH THE SLOWER MOVEMENT OF THE SYSTEM MONDAY...WHICH WILL KEEP LIGHT PRECIPITATION ACROSS THE FORECAST AREA. ACROSS NORTHERN AREAS EXPECT EXPECT A LIGHT WINTRY MIX...WITH A WINTRY MIX TRANSITIONING TO RAIN ACROSS CENTRAL AND DOWNEAST AREAS. THE SURFACE/UPPER LOW WILL MOVE EAST MONDAY NIGHT WHILE HIGH PRESSURE SLOWLY BUILDS SOUTH WITH DECREASING RAIN/SNOW SHOWER CHANCES ACROSS THE FORECAST AREA. A SLIGHT CHANCE OF SHOWERS COULD PERSIST DOWNEAST TUESDAY WITH THE EXITING LOW WHILE HIGH PRESSURE BUILDS ACROSS NORTHERN MAINE. TEMPERATURES WILL BE AT SLIGHTLY BELOW NORMAL LEVELS MONDAY/TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... LOW PRESSURE WILL BE MOVING AWAY TUESDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. THIS WILL BRING DRY AND RELATIVELY MILD WEATHER TUESDAY NIGHT INTO WEDNESDAY. A WEAK TROUGH MAY MOVE THROUGH ON THURSDAY BRINGING SOME CLOUDS AND PERHAPS LIGHT SHOWERS. OTHERWISE, THE DAY SHOULD REMAIN MOSTLY CLOUDY. HIGH PRESSURE SHOULD THEN BUILD IN BRINGING DRIER AND SEASONABLY MILD CONDITIONS ON FRIDAY. GOING INTO THE WEEKEND, LOTS OF UNCERTAINTY REGARDING WHETHER OR NOT A BLOCKING RIDGE OVER EASTERN CANADA CAN MAINTAIN THE DRY WEATHER. THE GFS KEEPS CONDITIONS DRY WHILE THE ECMWF BRINGS A TROUGH OF LOW PRESSURE THROUGH WITH A CHANCE FOR SOME RAIN OR SNOW SHOWERS. IN THE FORECAST WILL HAVE LOW CHANCE FOR RAIN OR SNOW SHOWERS NEXT WEEKEND. CURRENTLY DOES NOT LOOK LIKE ANY MAJOR STORMS ARE EXPECTED THROUGH NEXT WEEKEND, AND TEMPERATURES WILL BE NEAR NORMAL WHICH WILL BE CONSIDERABLY MILDER THAN THE VERY COLD CONDITIONS WE HAVE HAD IN MARCH. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... NEAR TERM: DETERIORATING CONDITIONS SOUTH TO NORTH AS THE LOW MOVES INTO THE AREA. MVFR CONDITIONS BHB...ALL OTHER SITES VFR TO START THE PERIOD THIS EVENING. BY 9PM IFR CONDITIONS BHB IN RAIN...BGR RAIN BCMG MXD. IFR CONDITIONS MOVE INTO HUL...PQI...CAR...FVE AFT 3AM...PCPN SNOW BCMG MXD AT HUL TOMORROW AFTN. IFR CONDITION WILL REMAIN ACROSS THE AREA THROUGH THE END OF THE PERIOD. PCPN TYPE SN FOR FVE...SN MAY MIX WITH PL BRIEFLY IN AFTN IN PQI AND CAR. SHORT TERM: IFR/LIFR CONDITIONS ARE EXPECTED ACROSS THE REGION SUNDAY NIGHT INTO EARLY MONDAY...WITH MVFR/IFR CONDITIONS LATER MONDAY. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE REGION MONDAY NIGHT. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS DOWNEAST AREAS EARLY TUESDAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED ACROSS THE REGION TUESDAY. VFR CONDITIONS ARE EXPECTED ACROSS THE REGION WEDNESDAY. VFR CONDITIONS ARE EXPECTED ACROSS NORTHERN AREAS THURSDAY...WITH OCCASIONAL MVFR CONDITIONS POSSIBLE DOWNEAST. && .MARINE... NEAR TERM: THE LOW WILL TRANSIT SLOWLY SOUTH OF OF THE GULF OF MAINE. TODAYS TRACK IS FARTHER SOUTH THAN WAS PREVIOUS FORECASTED. WINDS STILL CALL FOR MARGINAL GALE FORCE WINDS FOR TOMORROW. WILL CONTINUE THE GALE WATCH. SHORT TERM: MARGINAL GALE CONDITIONS ARE POSSIBLE SUNDAY NIGHT INTO EARLY MONDAY NIGHT WHICH COULD REQUIRE GALE WARNINGS. VISIBILITIES WILL BE REDUCED IN RAIN SUNDAY NIGHT INTO EARLY MONDAY NIGHT...WITH LINGERING RAIN/SNOW SHOWERS POSSIBLE LATER MONDAY NIGHT INTO TUESDAY. && .HYDROLOGY... A FLOOD WATCH CONTINUES FOR DOWNEAST MAINE SUNDAY THROUGH MONDAY AFTERNOON. THE PRECIPITATION ASSOCIATED WITH THE UPCOMING STORM WILL LIKELY FALL MAINLY AS RAIN OR FREEZING RAIN IN THESE AREAS, ESPECIALLY ALONG THE COAST. TOTAL LIQUID PRECIPITATION AMOUNTS OF UP TO 3 INCHES ARE EXPECTED. IN ADDITION TO THIS RAIN...TEMPERATURES WILL REMAIN NEAR OR ABOVE FREEZING THROUGH SUNDAY ADDING SNOWMELT TO THE EQUATION. THE SNOWPACK IN THESE AREAS IS HIGHLY VARIABLE, RANGING FROM AROUND 6 INCHES ALONG THE COAST TO 2 FEET OR MORE IN THE INTERIOR. THERE IS 2 TO 4 INCHES OF WATER CONTAINED IN THE PACK ALONG THE COAST WITH 6 TO 8 INCHES FURTHER INLAND. WHILE THE DEEPER SNOW WILL BE ABLE TO ABSORB SOME OF THE RAIN...MUCH OF IT WILL BECOME RUNOFF IN ADDITION TO THE SNOWMELT. THIS MEANS DOWNEAST AREAS COULD POTENTIALLY SEE 4 INCHES OR MORE OF TOTAL RUNOFF. RIVERS WILL LIKELY RISE SUBSTANTIALLY AND POTENTIALLY CAUSE RIVER ICE TO BREAK UP...ESPECIALLY IN THOSE PLACES WHERE THE ICE COMPLETELY FLUSHED OUT IN JANUARY (MEANING THE ICE THERE NOW IS RELATIVELY WEAK). FOR THOSE RIVER STRETCHES THAT ARE ICE FREE...ICE COVER UPSTREAM MAY BREAK UP AND COLLECT DOWNSTREAM. IN ADDITION TO THE POTENTIAL FOR ICE JAMS, THIS AMOUNT OF RAINFALL AND RUNOFF WILL LIKELY LEAD TO PONDING OF WATER ON ROADWAYS AND MINOR FLOODING OF LOW-LYING POOR DRAINAGE AREAS. IN ADDITION, TIDAL LOCATIONS SUCH AS BANGOR WILL HAVE TO BE WATCHED CLOSELY AROUND THE TIME OF HIGH TIDE. THE CURRENT OFFICIAL NATIONAL WEATHER SERVICE FORECAST FOR THE PENOBSCOT RIVER AT BANGOR BRINGS THE GAGE WITHIN 1 FOOT OF FLOOD STAGE WITH HIGH TIDE SUNDAY MORNING. PERSONS WITH INTERESTS ALONG WATERWAYS OR IN FLOOD-PRONE LOCATIONS ACROSS HANCOCK...WASHINGTON AND SOUTHERN PENOBSCOT COUNTIES SHOULD STAY TUNED FOR ADDITIONAL INFORMATION ON THIS SYSTEM. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER STORM WARNING FROM 6 AM SUNDAY TO 8 AM EDT MONDAY FOR MEZ001-002. WINTER STORM WARNING FROM 2 AM SUNDAY TO 8 AM EDT MONDAY FOR MEZ003>006-010. WINTER WEATHER ADVISORY FROM 2 AM SUNDAY TO 8 AM EDT MONDAY FOR MEZ011-015>017-031-032. FLOOD WATCH FROM SUNDAY MORNING THROUGH MONDAY AFTERNOON FOR MEZ015>017-029-030. MARINE...GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR ANZ050>052. && $$ NEAR TERM...NORTON/VJN SHORT TERM...NORCROSS LONG TERM...BLOOMER AVIATION...NORTON/VJN/NORCROSS MARINE...NORTON/VJN/NORCROSS HYDROLOGY...NORTON
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
926 PM CDT Sat Mar 29 2014 .UPDATE: Issued at 919 PM CDT Sat Mar 29 2014 Area of MVFR stratus has continued to dissipate and is now confined to portions of south-central Illinois. Expect this area to completely erode by 0600 UTC with mainly clear skies for most of the rest of tonight. Exception would be over western areas as cirrus tries to advect in from the west/northwest. Surface temperatures over the past two hours have dropped very rapidly over most of the region where combination of clear skies/light winds exist. Lowered minimum temperatures a few degrees over many areas using a blend of the 0000 UTC RAP which was capturing this rapid drop fairly well as well as the previous forecast. Other concern overnight will be fog potential and patchy fog with restricted visibilities below 3 miles still looks on track though certainly could not rule out some denser fog especially in river valleys and other low-lying elevations. Gosselin && .SHORT TERM: (Through Late Tonight) Issued at 320 PM CDT Sat Mar 29 2014 Pesky stratus seems to be both clearing and eroding at a snails pace this afternoon and has a done number on the temperatures. Present indications based on satellite trends and the RAP which has handled the low clouds best, is that areas generally along and east of the MS River will see clouds into early evening with clearing from mid-late evening. Otherwise the expansive NE-SW high pressure system currently extending from WI into TX will slide east across the region tonight with the axis centered thru SE MO and southern IL at 12z. The slow clearing trend of the clouds along with light winds overnight across the SE third of the CWA has prompted me to add a mention of fog overnight. Glass .LONG TERM: (Sunday through Next Saturday) Issued at 320 PM CDT Sat Mar 29 2014 It finally looks like the warm-up will commence on Sunday. Heights aloft that begin rising tonight in the wake of the departing upper trof, will continue to rise on Sunday while the surface high retreats and low level southerly flow and warm advection get underway. There should be no low clouds to deal with a just some thin high clouds filtering across the region. The current forecast leveraging the warmer temperatures looks right on the mark and no changes were made. The warmer temps combined with low afternoon RH values and increasing southerly winds support an elevated fire danger threat across central and east central MO, which will be highlighted in the HWO. Continued southerly low level flow on Sunday night will lead to "milder" min temperatures and a slow return in low level moisture. The aforementioned expansive surface high and its southern extent will initially have a profounded effect on trajectories and delay quality moisture return. However mid level moisture won`t be an issue and this along with the eastern edge of steeper mid level lapse rates spreads into central MO just before daybreak on Monday. These ingredients along with the leading edge of forcing aloft associated with an upstream trof, suggests potential for some high-based scattered showers/thunderstorms and hence have added some slight chance pops. The week ahead looks especially active. The migratory upper trof partly responsible for the slight chance pops late Sunday night will move across the region Monday afternoon and early evening spreading height falls and cooling aloft along with a plume of steep mid level lapse rates. This combined with a gradual increase in low level moisture and forcing should be sufficient for scattered elevated showers/thunderstorms within the warm sector, moving through central and northeast MO during the morning gradually dwindling in coverage during the afternoon as they move east. By the time the cold front moves through the area Monday night, forcing aloft appears to have outrun the front and boundary layer moisture and hence instability are quite weak. I suspect anything that might be able to develop with be quite spotty and just have a slight chance pop. The most active period will be late Tuesday night into Thursday. The front that moves through Monday night will move back north and waver across the region. The warm sector air mass south of this boundary will become quite unstable thanks to continued northward return of quality Gulf moisture and the presence of steep mid level lapse rates, and with a strong low level jet evolving there will be good elevated instability and forcing north this boundary. The models differ quite a bit on the position of the next formidable migratory upper trof and the position of attendant surface low(s) and this boundary. While all the guidance supports a stormy period, the more northern position which has been consistently advertised by the ECMWF would lead to a much more volatile set-up. Glass && .AVIATION: (For the 00z TAFs through 00z Sunday Evening) Issued at 546 PM CDT Sat Mar 29 2014 Specifics for KCOU: Although light fog is possible tonight across the region, KCOU experienced sufficient daytime mixing to limit the overnight fog potential. Winds start to increase by 12z due to the tightening pressure gradient between a surface high to the southeast and a developing low to the northwest. Specifics for KSTL, KSUS, KCPS, KUIN: Stratus was slow to clear today and nearly clear skies with light winds are expected overnight. The combination of limited daytime mixing and good radiational cooling conditions will probably lead to light fog formation, especially near and east of the Mississippi River. Winds start to increase by 12z due to the tightening pressure gradient between a surface high to the southeast and a developing low to the northwest. Kanofsky && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
257 AM CDT Fri Mar 28 2014 .SHORT TERM: (Through Sunday) Issued at 255 AM CDT Fri Mar 28 2014 Surface low moving northeast across Lake Michigan this morning with the trailing cold front about to exit the eastern CWA. Large area of "wrap around" clouds affecting the northern half of the CWA this morning will continue to move east and scatter with strong late March insolation. Clouds will be on the increase again by this afternoon as the next shortwave trof currently crossing the Rockies digs toward the Midwest. Model guidance in good agreement that surface low pressure will develop in eastern TX and move northeast into TN by Saturday morning. Deepening mid/upper level trof will cause rain to develop and increase from the southwest late this afternoon, covering the southeastern half of the CWA this evening. Greatest QPF (as much as a half inch) look to remain across the eastern Ozarks, southeast MO and southern IL, with lighter amounts of a tenth of an inch or less up to St. Louis and south central IL. Trof will quickly move east of the area by Saturday morning with seasonal temperatures and dry conditions expected as a surface ridge builds into the Middle Mississippi River Valley from the Plains. 500mb heights quickly rise and return surface flow ensues on Sunday in the wake of the surface ridge. Temperatures expected to jump well above normal and have forecast highs a few degrees above the warmest guidance given favorable synoptic pattern. CVKING .LONG TERM: (Sunday Night through Thursday) Issued at 255 AM CDT Fri Mar 28 2014 Active weather pattern expected next week with a cold front moving across the region on Sunday night/Monday morning providing a chance of showers, with a larger synoptic system affecting the region Tuesday night through at least Thursday morning. Temperatures will be cooler than average in the wake of the cold front on Tuesday, but moderation is expected as early as Wednesday as a warm front is advertised to develop and move north into the Midwest. Models advertising some healthy QPF with this system, which is welcome news given the 3 month precipitation deficits. CVKING && .AVIATION: (For the 06z TAFs through 06z Friday Night) Issued at 1147 PM CDT Thu Mar 27 2014 Convection over southeast sections of the CWA will continue to move away from the TAF sites, and primary overnight concern deals with SC and associated MVFR cigs (2-3kft) that are rotating across the northern half of Missouri in the wake of the cold front. Earlier RAP runs appear to have the best handle on this low level moisture, which has now made it as far south as COU, and should work into the STL metro area over the next few hours. Then expect cloud deck to gradually clear/dissipate from SW to NE across the CWA in the 12-16z time frame due to combination of low level drying, diurnal heating, and loss of cyclonic curvature. Approach of next shortwave should mean thickening mid clouds by early tomorrow evening, with a few showers threatening the STL metro late in the period. Specifics for KSTL: As mentioned above, MVFR cigs (2-3kft) that have dropped into mid MO should arrive in the STL area over the next few hours and linger into early tomorrow morning. Forecast soundings then suggest a gradual clearing trend by mid morning which will cause the low cloud deck to scatter out. Mid level cloud deck in advance of the next system will begin increasing by late afternoon, with a few showers moving into the area in the 03-06z time frame. Truett && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 57 41 57 38 / 5 80 5 0 Quincy 51 35 54 36 / 5 10 5 0 Columbia 54 36 59 38 / 10 20 5 0 Jefferson City 56 36 59 37 / 10 20 5 0 Salem 56 40 55 34 / 5 80 10 0 Farmington 61 40 59 35 / 20 80 5 0 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1203 AM CDT Fri Mar 28 2014 .SHORT TERM: (Through Late Tonight) Issued at 306 PM CDT Thu Mar 27 2014 A dynamic low pressure system will push rapidly across our forecast area late this afternoon and this evening. Wind shear params are quite favorable for strong to severe storms. However, instability params are currently not as favorable as indicated by the 18z SGF sounding. It shows a strong mid-level cap (CIN 315 J/kg) and lower instability available without much additional surface heating. Some clearing is developing about and hour or two before the line of storms arrives, per satellite and radar loops. We will continue to expect a line of convection to race through the area starting between 4 and 5 pm for our western counties and reaching our eastern counties by 10 or 11 pm. The primary hazards will be large hail and damaging winds, especially the cap erodes sufficiently for uninhibited updrafts. Behind the line of storms and cold fropa, we should see some clearing develop from west to east after midnight as steady NW winds bring colder are to the region. Shimon .LONG TERM: (Friday through Next Thursday) Issued at 306 PM CDT Thu Mar 27 2014 Despite some sunshine on Friday the mixing of 850mb temps in the 2C to 8C range will keep highs around 50 north with around 60 south. Increasing clouds in the afternoon will indicate the approach of the next low pressure system. That shortwave is forecast to track just south of Missouri and Illinois, with varying solutions in the 12z models as to how far north the precipitation shield will extend Friday evening. The GFS and Canadian GEM continue to be the most aggressive with the northern extent, covering a majority of the LSX forecast area, while the NAM and ECMWF just affect the southeastern third of the area. We confined likely PoPs in th evening to the southeastern areas where the best forcing for precip will most likely reside, with chance PoPs in all but the NW third. After midnight Friday night, the wave will quickly slide to the east and dry air will help to limit the northern extent to areas southeast of St Louis. Dry and cool conditions will return for Saturday as sunshine prevails for much of the day. Surface ridging and steady height rises aloft on Sunday will produce a noticeable warming trend, as highs climb into the mid 60s to around 70. The mild conditions will extend into Monday but precipitation chances will increase Monday morning ahead of a cold front. Low pressure will track from eastern Colorado to Iowa on Monday, as its trailing cold front reaches western Missouri by 00z/7pm Monday. Moisture will be limited this far south of the system, so precip coverage only warranted chance PoPs for now. A few light showers may linger in western Illinois Monday night, but most areas should see dry conditions overnight. The next in a long series of weather systems is projected to arrive in the area late Tuesday night or Wednesday, as a warm frontogenesis develops across our forecast area from SW to NE. Per the GFS, low pressure will eventually track NE along that front later Wed into Wed evening, increasing precip chances into the likely category in the NW Wed afternoon and the SE Wed night. Timing differences in the extended have prompted the inclusion of chance PoPs as late as Thursday due to the ECMWF indicating a delayed passage of low pressure along the front. Shimon && .AVIATION: (For the 06z TAFs through 06z Friday Night) Issued at 1147 PM CDT Thu Mar 27 2014 Convection over southeast sections of the CWA will continue to move away from the TAF sites, and primary overnight concern deals with SC and associated MVFR cigs (2-3kft) that are rotating across the northern half of Missouri in the wake of the cold front. Earlier RAP runs appear to have the best handle on this low level moisture, which has now made it as far south as COU, and should work into the STL metro area over the next few hours. Then expect cloud deck to gradually clear/dissipate from SW to NE across the CWA in the 12-16z time frame due to combination of low level drying, diurnal heating, and loss of cyclonic curvature. Approach of next shortwave should mean thickening mid clouds by early tomorrow evening, with a few showers threatening the STL metro late in the period. Specifics for KSTL: As mentioned above, MVFR cigs (2-3kft) that have dropped into mid MO should arrive in the STL area over the next few hours and linger into early tomorrow morning. Forecast soundings then suggest a gradual clearing trend by mid morning which will cause the low cloud deck to scatter out. Mid level cloud deck in advance of the next system will begin increasing by late afternoon, with a few showers moving into the area in the 03-06z time frame. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1211 PM CDT FRI MAR 28 2014 .UPDATE... ISSUED AT 1116 AM CDT FRI MAR 28 2014 MADE SOME ADJUSTMENTS TO THE FORECAST TODAY...ADDING IN A CHANCE OF SPRINKLES ACROSS SOUTHEAST NEBRASKA. VERY SUBTLE DISTURBANCE ON WATER VAPOR MOVING OUT OF NORTH CENTRAL KANSAS COULD GENERATE SOME PRECIP ALONG THE NE/KS BORDER REGION THIS MORNING. ALSO DROPPED TEMPS THERE JUST A BIT DUE TO INCREASED CLOUD COVER. COULD ALSO BE A FLURRY IN EXTREME NORTHEAST NEBRASKA...BUT BELIEVE ECHOES ARE PROBABLY ALOFT THERE. HOWEVER...SLIGHT PRECIP CHANCES TUCKED IN WITH THE UPPER TROUGH...CURRENTLY MOVING THROUGH CENTRAL SOUTH DAKOTA...COULD MOVE INTO NORTHEAST NEBRASKA LATER THIS AFTERNOON AND LINGER FOR AN HOUR OR TWO EARLY THIS EVENING...MORE IN LINE WITH LATEST RAP SUGGESTION. ALSO DROPPED TEMPS IN NORTHEAST NEBRASKA DUE TO THE POOR MIXING AND CLOUD COVER. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 304 AM CDT FRI MAR 28 2014 THE SHORTWAVE TROUGH THAT BROUGHT THE WEATHER TO THE AREA ON THURSDAY IS MOVING THROUGH THE MID MS RIVER VALLEY EARLY THIS MORNING. ON THE HEELS OF THIS SYSTEM EARLY MORNING WATER VAPOR IMAGERY INDICATED ANOTHER SHORTWAVE TROUGH OVER THE HIGH PLAINS. REGIONAL RADAR MOSAIC INDICATES THAT SCT LIGHT PRECIP ASSOCIATED WITH THIS SYSTEM EXTENDS FROM SW SD INTO WRN KS. MODELS ARE CONSISTENT IN TAKING THIS SHORTWAVE TROUGH EAST TODAY ACROSS THE FA. LARGE-SCALE FORCING FOR ASCENT DOES INCREASE THROUGH THE DAY AS THE BETTER 500 TO 300 MB Q-VECTOR CONVERGENCES MOVES THROUGH. THE SYSTEM WILL BE MOVING INTO A DRY ATMOSPHERE WITH INCREASING STATIC STABILITY THOUGH...WHICH IS EXPECTED TO SIGNIFICANTLY LIMIT THE IMPACT TO THE SENSIBLE WEATHER FOR EASTERN NEB/WESTERN IA. WE WILL SEE PERIODS OF CLOUDS TODAY /INITIALLY A WAA BAND THIS MORNING FOLLOWED BY SOME POSSIBLE SUNSHINE AND MORE CLOUDS ASSOCIATED WITH THE DPVA LATE THIS AFTERNOON/. WE HAVE CONFINED THE AREAL EXTENT OF THE PRECIP TO OUR FAR NORTHWEST COUNTIES AND WE WOULDN`T BE SURPRISED IF OUR ENTIRE AREA STAYS DRY TODAY. WITH SOME PARTIAL SUNSHINE EXPECTED TODAY WE DID INCREASE HIGHS A TOUCH ALONG AND SOUTH OF I80. THE SURFACE RIDGE IN THE WAKE OF THIS SHORTWAVE TROUGH WILL CROSS THE FA TONIGHT AND WITH SKIES CLEARING...WINDS BECOMING LIGHT AND VARIABLE...AND RECENT RAIN WE LEFT IN THE FOG MENTION FOR FRI NIGHT. RETURN FLOW WILL START LATE FRIDAY NIGHT INTO THE DAY ON SATURDAY WITH SOUTHERLY WINDS INCREASING. WITH FULL SUNSHINE AND A DRY GROUND WE SHOULD SEE DECENT MIXING WITH HIGHS IN THE 60S IN ERN NEB AND UPPER 50S WRN IA. AS THE NEXT SHORTWAVE TROUGH MOVES INTO THE ROCKIES SAT NIGHT SURFACE CYCLOGENESIS WILL INCREASE OVER THE HIGH PLAINS LEADING TO A BREEZY AND MILD NIGHT FOR THE FA. WITH MILD OVERNIGHT TEMPS ON SAT NIGHT THIS SHOULD SET THE STAGE FOR A WARM AND WINDY SUN. MODELS INDICATE MID LEVEL LAPSE RATES OF 7.5 TO 8.5 C/KM ON SAT NIGHT AND HINT AT SOME MOISTURE IN THIS LAYER AS WELL. THIS COULD LEAD TO SOME ACCAS SAT NIGHT INTO SUNDAY BUT ATTM DOESN`T APPEAR THAT THIS WOULD NEGATIVELY AFFECT HIGHS ON SUNDAY WITH 70S LIKELY SOUTH OF THE WARM FRONT AND AHEAD OF THE COLD FRONT. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 304 AM CDT FRI MAR 28 2014 THE SHORTWAVE TROUGH IN THE SHORT TERM WILL EJECT NEWD ON SUNDAY NIGHT WITH A SURFACE LOW CROSSING NEB OVERNIGHT. THE MODELS ARE VERY CONSISTENT IN DEVELOPING A STRONG LOW-LEVEL JET ON SUNDAY NIGHT ACROSS KS INTO NEB/IA. THE NAM HAS MUCH HIGHER H85 DEWPOINTS AND APPEARS TO BE AN OUTLIER COMPARED TO THE EC/GFS. THE NAM/SREF DEVELOPS SOME CONVECTIVE PRECIP...BUT POINT FORECAST SOUNDINGS FROM THE NAM/SREF ARE STRONGLY CAPPED ON SUNDAY NIGHT EVEN WITH THE HIGHER MOISTURE PROFILE. WE MAY SEE A FEW SHOWERS ABOVE THE CAP OVER THE EASTERN 2/3RD OF THE FA AND WILL MAINTAIN SOME SCHC POPS FOR THIS POSSIBILITY. THE SURFACE COLD FRONT WILL BE MOVING THROUGH THE FA ON MONDAY WITH THE DEFORMATION ZONE MOVING ACROSS SD/MN. SOME OF THIS MAY CLIP NE NEB AND WILL CONT WITH SOME CHC POPS THERE DURING THE DAY. THE PERIOD MONDAY NIGHT THROUGH TUES LOOKS QUIET AND DRY BEFORE THE NEXT SHORTWAVE TROUGH MOVES INTO THE CENTRAL PLAINS. THE EC/GFS HAVE STRONG DIFFERENCES IN THE TIMING AND TRACK OF THIS SYSTEM...BUT CHC POPS FOR SOME RA APPEAR WARRANTED DURING THIS PERIOD. WE WILL INCLUDE SOME CHC OF RA/SN IN THE NW DURING THE OVERNIGHT PERIODS. OTHERWISE BELOW NORMAL TEMPERATURES ARE EXPECTED FOR THE EXTENDED PERIOD OF THE FORECAST. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1209 PM CDT FRI MAR 28 2014 MVFR CEILINGS AT KOMA WERE BEGINNING TO MOVE BACK EAST BASED ON RECENT SATELLITE IMAGERY AND WILL PROBABLY GO BACK TO VFR BY 20Z AT THAT LOCATION. OTHERWISE...VFR CONDITIONS PREVAIL THROUGH THE PERIOD WITH LIGHT WINDS GENERALLY LESS THAN 7 KNOTS. WINDS DO BECOME SOUTH ON SATURDAY...AND COULD APPROACH 12 KNOTS AT KOFK BY 16Z...BUT NOT UNTIL AFTER THE END OF THE TAF PERIOD AT BOTH KLNK/KOMA. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ UPDATE...DEWALD SHORT TERM...BOUSTEAD LONG TERM...BOUSTEAD AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1121 AM CDT FRI MAR 28 2014 .UPDATE... ISSUED AT 1116 AM CDT FRI MAR 28 2014 MADE SOME ADJUSTMENTS TO THE FORECAST TODAY...ADDING IN A CHANCE OF SPRINKLES ACROSS SOUTHEAST NEBRASKA. VERY SUBTLE DISTURBANCE ON WATER VAPOR MOVING OUT OF NORTH CENTRAL KANSAS COULD GENERATE SOME PRECIP ALONG THE NE/KS BORDER REGION THIS MORNING. ALSO DROPPED TEMPS THERE JUST A BIT DUE TO INCREASED CLOUD COVER. COULD ALSO BE A FLURRY IN EXTREME NORTHEAST NEBRASKA...BUT BELIEVE ECHOES ARE PROBABLY ALOFT THERE. HOWEVER...SLIGHT PRECIP CHANCES TUCKED IN WITH THE UPPER TROUGH...CURRENTLY MOVING THROUGH CENTRAL SOUTH DAKOTA...COULD MOVE INTO NORTHEAST NEBRASKA LATER THIS AFTERNOON AND LINGER FOR AN HOUR OR TWO EARLY THIS EVENING...MORE IN LINE WITH LATEST RAP SUGGESTION. ALSO DROPPED TEMPS IN NORTHEAST NEBRASKA DUE TO THE POOR MIXING AND CLOUD COVER. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 304 AM CDT FRI MAR 28 2014 THE SHORTWAVE TROUGH THAT BROUGHT THE WEATHER TO THE AREA ON THURSDAY IS MOVING THROUGH THE MID MS RIVER VALLEY EARLY THIS MORNING. ON THE HEELS OF THIS SYSTEM EARLY MORNING WATER VAPOR IMAGERY INDICATED ANOTHER SHORTWAVE TROUGH OVER THE HIGH PLAINS. REGIONAL RADAR MOSAIC INDICATES THAT SCT LIGHT PRECIP ASSOCIATED WITH THIS SYSTEM EXTENDS FROM SW SD INTO WRN KS. MODELS ARE CONSISTENT IN TAKING THIS SHORTWAVE TROUGH EAST TODAY ACROSS THE FA. LARGE-SCALE FORCING FOR ASCENT DOES INCREASE THROUGH THE DAY AS THE BETTER 500 TO 300 MB Q-VECTOR CONVERGENCES MOVES THROUGH. THE SYSTEM WILL BE MOVING INTO A DRY ATMOSPHERE WITH INCREASING STATIC STABILITY THOUGH...WHICH IS EXPECTED TO SIGNIFICANTLY LIMIT THE IMPACT TO THE SENSIBLE WEATHER FOR EASTERN NEB/WESTERN IA. WE WILL SEE PERIODS OF CLOUDS TODAY /INITIALLY A WAA BAND THIS MORNING FOLLOWED BY SOME POSSIBLE SUNSHINE AND MORE CLOUDS ASSOCIATED WITH THE DPVA LATE THIS AFTERNOON/. WE HAVE CONFINED THE AREAL EXTENT OF THE PRECIP TO OUR FAR NORTHWEST COUNTIES AND WE WOULDN`T BE SURPRISED IF OUR ENTIRE AREA STAYS DRY TODAY. WITH SOME PARTIAL SUNSHINE EXPECTED TODAY WE DID INCREASE HIGHS A TOUCH ALONG AND SOUTH OF I80. THE SURFACE RIDGE IN THE WAKE OF THIS SHORTWAVE TROUGH WILL CROSS THE FA TONIGHT AND WITH SKIES CLEARING...WINDS BECOMING LIGHT AND VARIABLE...AND RECENT RAIN WE LEFT IN THE FOG MENTION FOR FRI NIGHT. RETURN FLOW WILL START LATE FRIDAY NIGHT INTO THE DAY ON SATURDAY WITH SOUTHERLY WINDS INCREASING. WITH FULL SUNSHINE AND A DRY GROUND WE SHOULD SEE DECENT MIXING WITH HIGHS IN THE 60S IN ERN NEB AND UPPER 50S WRN IA. AS THE NEXT SHORTWAVE TROUGH MOVES INTO THE ROCKIES SAT NIGHT SURFACE CYCLOGENESIS WILL INCREASE OVER THE HIGH PLAINS LEADING TO A BREEZY AND MILD NIGHT FOR THE FA. WITH MILD OVERNIGHT TEMPS ON SAT NIGHT THIS SHOULD SET THE STAGE FOR A WARM AND WINDY SUN. MODELS INDICATE MID LEVEL LAPSE RATES OF 7.5 TO 8.5 C/KM ON SAT NIGHT AND HINT AT SOME MOISTURE IN THIS LAYER AS WELL. THIS COULD LEAD TO SOME ACCAS SAT NIGHT INTO SUNDAY BUT ATTM DOESN`T APPEAR THAT THIS WOULD NEGATIVELY AFFECT HIGHS ON SUNDAY WITH 70S LIKELY SOUTH OF THE WARM FRONT AND AHEAD OF THE COLD FRONT. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 304 AM CDT FRI MAR 28 2014 THE SHORTWAVE TROUGH IN THE SHORT TERM WILL EJECT NEWD ON SUNDAY NIGHT WITH A SURFACE LOW CROSSING NEB OVERNIGHT. THE MODELS ARE VERY CONSISTENT IN DEVELOPING A STRONG LOW-LEVEL JET ON SUNDAY NIGHT ACROSS KS INTO NEB/IA. THE NAM HAS MUCH HIGHER H85 DEWPOINTS AND APPEARS TO BE AN OUTLIER COMPARED TO THE EC/GFS. THE NAM/SREF DEVELOPS SOME CONVECTIVE PRECIP...BUT POINT FORECAST SOUNDINGS FROM THE NAM/SREF ARE STRONGLY CAPPED ON SUNDAY NIGHT EVEN WITH THE HIGHER MOISTURE PROFILE. WE MAY SEE A FEW SHOWERS ABOVE THE CAP OVER THE EASTERN 2/3RD OF THE FA AND WILL MAINTAIN SOME SCHC POPS FOR THIS POSSIBILITY. THE SURFACE COLD FRONT WILL BE MOVING THROUGH THE FA ON MONDAY WITH THE DEFORMATION ZONE MOVING ACROSS SD/MN. SOME OF THIS MAY CLIP NE NEB AND WILL CONT WITH SOME CHC POPS THERE DURING THE DAY. THE PERIOD MONDAY NIGHT THROUGH TUES LOOKS QUIET AND DRY BEFORE THE NEXT SHORTWAVE TROUGH MOVES INTO THE CENTRAL PLAINS. THE EC/GFS HAVE STRONG DIFFERENCES IN THE TIMING AND TRACK OF THIS SYSTEM...BUT CHC POPS FOR SOME RA APPEAR WARRANTED DURING THIS PERIOD. WE WILL INCLUDE SOME CHC OF RA/SN IN THE NW DURING THE OVERNIGHT PERIODS. OTHERWISE BELOW NORMAL TEMPERATURES ARE EXPECTED FOR THE EXTENDED PERIOD OF THE FORECAST. && .AVIATION...(12Z TAFS FOR KOFK...KLNK...AND KOMA.) ISSUED AT 607 AM CDT FRI MAR 28 2014 LIGHT AND VARIABLE WINDS ARE EXPECTED THROUGH THE TAF PERIOD. BANK OF MVFR STRATUS IS PUSHING WESTWARD TOWARD KOMA...AND WILL LIKELY IMPACT THE TAF SITE FOR MUCH OF THE MORNING...WITH VFR CONDITIONS EXPECTED AFTER IT CLEARS AROUND MIDDAY AS MID-LEVEL CEILINGS EVENTUALLY GIVE WAY TO CLEARING TONIGHT. AT KOFK...VFR CONDITIONS ARE LIKELY THROUGH TODAY...WITH SOME PERIOD OF LOW-END VFR CEILINGS POSSIBLE THIS AFTERNOON. AT KLNK...VFR CEILINGS ARE EXPECTED TODAY...WITH CLEARING SKIES TONIGHT. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ UPDATE...DEWALD SHORT TERM...BOUSTEAD LONG TERM...BOUSTEAD AVIATION...MAYES
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
633 AM CDT FRI MAR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 347 AM CDT FRI MAR 28 2014 THE UPPER LEVEL LOW ACROSS NERN WY APPEARS TO BE DRIFTING EAST SOUTHEAST WHICH WOULD CARRY IT INTO NRN NEBRASKA THIS AFTERNOON. A WARM FRONT IS EXPECTED TO LIFT NORTH AHEAD OF THE LOW PUSHING TEMPERATURES INTO THE UPPER 50S ACROSS SWRN NEB WHILE THE FAR NORTHEAST REMAINS IN THE UPPER 30S. THE RAP...GEM REGIONAL AND NAM CONTINUE ISOLATED TO SCATTERED SNOW SHOWERS ALONG THE FRONT WHICH TRANSITIONS TO RAIN SHOWERS THIS AFTN SOUTH OF THE FRONT. VERY LITTLE QPF IS EXPECTED...0.05 INCHES OR LESS WITH THIS SYSTEM BUT THIS COULD BE UNDERDONE GIVEN THE MODELS MAY BE USING RADAR AS A QPF GUIDE AND THERE IS NO RADAR COVERAGE ACROSS NERN WY. SO POPS ARE ISOLATED TO SCATTERED AND A WAIT AND SEE APPROACH IS IN PLACE UNTIL THE SYSTEMS CLEARS THE BLACK HILLS. OBSERVATION SITES IN NORTHEAST WYOMING HAVE DROPPED BELOW 1 MILE AT TIMES IN THE SNOW SO THERE MAY AN OPPORTUNITY FOR HIGHER QPF THAN SHOWN BY THESE MODELS. THE ECM DOES NOT PRODUCE VERY HIGH QPF EITHER. THIS SYSTEM EXITS THE FCST AREA THIS EVENING AND IN DOING SO TUGS ANOTHER WEAK AREA OF ARCTIC HIGH PRESSURE INTO THE FCST AREA OVERNIGHT. LOWS IN THE 20S ARE EXPECTED TONIGHT AND WE SHOULD SEE A WARM FRONT LIFTING THROUGH WRN NEB AFTER MIDNIGHT SETTING THINGS UP FOR A WARM DAY ON SATURDAY. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 AM CDT FRI MAR 28 2014 A TRANSIENT LOW AMPLITUDE RIDGE WILL BUILD ACROSS THE CENTRAL/NORTHERN PLAINS THIS WEEKEND...BUT THEN BREAK DOWN LATE SUNDAY WITH THE APPROACH OF A SOUTH-CENTRAL ROCKIES SHORTWAVE TROUGH. AT THE SURFACE...A LEE TROUGH OVER THE HIGH PLAINS WILL DEVELOP SATURDAY IN ADVANCE OF THE APPROACHING UPPER TROUGH. THIS WILL ALLOW FOR A INCREASING PRESSURE GRADIENT ACROSS CENTRAL NEBRASKA AS HIGH PRESSURE REMAINS IN THE VICINITY OF THE GREAT LAKES. TEMPERATURES WILL SOAR IN ADVANCE OF THE LEE SFC TROUGH AS A DOWNSLOPING SOUTHWESTERLY COMPONENT OF THE LOWER TROPOSPHERIC WIND COMBINES WITH A FULL LATE MARCH SUN. HIGHS WILL REACH WELL INTO THE 70S SATURDAY FOR MUCH OF THE SANDHILLS REGION AND POINTS SOUTH WITH UPPER 60S ELSEWHERE. DEW POINT FORECAST IS PROBLEMATIC AT THIS POINT...MODEL GUIDANCE HAS STRUGGLE WITH RECENT SIMILAR EVENTS DISPLAYING A MOIST BIAS OF 20 DEGREES OR MORE AT TIMES ACROSS THE CENTRAL SANDHILLS AND SOUTHWEST NEBRASKA. ECM DATA AND THE WRF-ARW SEEM TO HAVE HANDLE THOSE CASES BETTER...KEYING IN ON THE ADVECTION/MIXING OF ABNORMALLY DRY AIR FROM OUR SOUTHWEST. THOSE MODELS WERE USED AS A STARTING POINT...AND THEN ADJUSTED MANUALLY TO ACCOUNT FOR THE INCREASED MIXING/DRYING. IN ADDITION...THE SHARPENING PRESSURE GRADIENT ELUDED TO ABOVE WILL WORK IN CONJUNCTION WITH DEEP MIXING GENERATED FROM STEEP LOW LEVEL LAPSE RATES TO ALLOW FOR GUSTS IN EXCESS OF 25...POSSIBLY 35 MPH...RANGE LATE MORNING THROUGH MUCH OF THE AFTERNOON. GIVEN THE LARGE TD AND DRY BULB SPREAD...MINIMUM RH OF 15 PERCENT OR LESS IS LIKELY FOR MUCH OF THE SANDHILLS FIRE ZONES. WILL ISSUE A FIRE WEATHER WATCH FOR ZONES 204...206...209...210 & 219 WITH THIS FORECAST PACKAGE WITH THE ANTICIPATION THAT A RFW WILL BE REQUIRED. SUNDAY IS A BIT LESS APPARENT...INCREASING HIGH LEVEL CLOUDS WILL SHADE OUR CURED 1HR FUELS AND WINDS ARE FAR LESS CERTAIN. DESPITE A SIMILAR TD/T SETUP AND FAVORABLE UPPER LEVEL RIDGE BREAKDOWN PATTERN...WILL HOLD OFF FOR ANOTHER MODEL SUITE UNTIL ISSUING ANY FIRE HEADLINES FOR SUNDAY. GUIDANCE DISAGREES ON THE LOCATION OF A SFC TROUGH/WARM FRONT...WITH THE ECM AND GFS OFF BY GREATER THAN 100 MILES...THERE/S BUST POTENTIAL CONCERNING MAXIMUM TEMPERATURES ACROSS OUR NORTHERN ZONES ON SUNDAY. AS OF NOW...GENERALLY SIDED WITH THE ECM CAMP WHICH IS THE WARMER AND DRIER SOLUTION FOR MUCH OF THE CWA. HIGHS MAY APPROACH 80F SOUTH OF I80 SUNDAY AFTERNOON...WHERE ALONG THE SOUTH DAKOTA BORDER...MID 60S IS FORECAST. SOME CONVECTION IS POSSIBLE LATE SUNDAY AFTERNOON AND EVENING AS THE WAVE TRANSLATES EAST ONTO THE PLAINS...STEEP LAPSE RATES WILL RESULT IN AT LEAST WEAK ELEVATED INSTABILITY ACROSS THE ENTIRE CWA...HOWEVER LOWER TROPOSPHERIC MOISTURE WILL BE LACKING. SFC TD/T SPREADS OF UP TO 40-50F WILL YIELD HIGH BASED STORMS CAPABLE OF GUSTY OUTFLOW WIND AND POSSIBLY A FEW CG STRIKES. MODIFIED ARCTIC AIR WILL BE PULLED SOUTH BEHIND THE WAVE ON MONDAY...WHICH MAY PROVIDE FOR SOME SNOW ACROSS OUR NORTHERN ZONES...BUT ATTM THE MODELS SEEM TO BE TARGETING THE NORTHERN PLAINS WITH THE BEST FORCING/HEAVIEST QPF/ACCUMULATIONS. BEYOND MONDAY...QUASI-ZONAL TO AT TIMES SOUTHWEST FLOW ALOFT WILL TARGET THE CENTRAL PLAINS THROUGH LATE WEEK. THE MODELS ARE TRENDING TO ANOTHER TROUGH ENCOMPASSING MUCH OF THE WEST COAST BYE LATE WEEK. UNSETTLED WEATHER IS PROBABLE IN THIS PATTERN WITH SEASONAL TO SLIGHTLY BELOW AVERAGE TEMPERATURES LIKELY FOR THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 633 AM CDT FRI MAR 28 2014 AREAS OF MVFR CIGS IN ISOLATED TO SCATTERED SNOW SHOWERS IMPROVE TO MOSTLY VFR FROM 18Z ONWARD. ONE AREA OF CONCERN IS ALONG U.S.HIGHWAY 20 WHERE AN ARCTIC FRONT WILL LIKELY STALL. THE RAP MODEL SUGGESTED MVFR/IFR CIGS NEAR KVTN THROUGH 02Z THIS EVENING. THE NAM AND GFS INDICATE MVFR IMPROVING TO VFR AND THIS IS WHAT THE FORECAST USES FOR KVTN. && .LBF WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR NEZ204-206-209-210-219. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
734 PM PDT SAT MAR 29 2014 .SYNOPSIS...A RAPIDLY DEVELOPING AREA OF LOW PRESSURE AND ASSOCIATED COLD FRONT WILL BRING VALLEY RAIN AND SNOW TO THE REGION TONIGHT THROUGH SUNDAY. A SMALL BREAK BETWEEN SYSTEMS SUNDAY NIGHT BEFORE ANOTHER PACIFIC STORM SYSTEM IMPACTS THE REGION MONDAY AFTERNOON THROUGH TUESDAY...BRINGING ANOTHER ROUND OF VALLEY RAIN AND SNOW. && .UPDATE...GUSTY WINDS HAVE NOT DEVELOPED OVER WHITE PINE AND NORTHEASTERN NYE COUNTIES...AND THE WIND ADVISORY HAS BEEN ALLOWED TO EXPIRE AT 8 PM. NO OTHER CHANGES AT THIS TIME. RCM && .PREV DISCUSSION... /ISSUED AT 343 PM / SYNOPSIS...A RAPIDLY DEVELOPING AREA OF LOW PRESSURE AND ASSOCIATED COLD FRONT WILL BRING VALLEY RAIN AND SNOW TO THE REGION TONIGHT THROUGH SUNDAY. A SMALL BREAK BETWEEN SYSTEMS SUNDAY NIGHT BEFORE ANOTHER PACIFIC STORM SYSTEM IMPACTS THE REGION MONDAY AFTERNOON THROUGH TUESDAY...BRINGING ANOTHER ROUND OF VALLEY RAIN AND SNOW. SHORT TERM...SATURDAY NIGHT THROUGH TUESDAY. CURRENT RUC ANALYSIS INDICATES A RAPIDLY DEEPENING AREA OF LOW PRESSURE FROM EUREKA TO ELY. THIS LOW PRESSURE IS PROGGED TO MOSTLY STAY STATIONARY AND DEEPEN THROUGH THE NIGHT AS THE TEMPERATURE GRADIENT TIGHTENS. IN ADDITION A DEEP PLUME OF PACIFIC MOISTURE IS STREAMING ACROSS NORTHERN NEVADA...WITH RAIN ALREADY BREAKING OUT ACROSS HUMBOLDT COUNTY. MODELS ARE ALL IN GOOD AGREEMENT BRINGING A WIDESPREAD AREA OF .25 TO .50" OF PRECIPITATION OVER THE REGION OVER THE NEXT 24 HOURS...WITH HIGHER AMOUNTS ACROSS THE MOUNTAINS. THE FORECAST CHALLENGE REMAINS WHEN WILL RAIN CHANGEOVER TO SNOW TONIGHT AND AT WHAT ELEVATION WILL THE SNOW ACCUMULATE AT. IT LOOKS LIKE THE VALLEYS OF HUMBOLDT COUNTY WILL REMAIN MOSTLY RAIN...WITH A MIX OF RAIN AND SNOW TOWARDS THE END OF THE EVENT...BUT NO ACCUMULATIONS. ACROSS ELKO COUNTY AND CENTRAL NEVADA THE CHANCE FOR ACCUMULATING SNOW IS MUCH HIGHER...DUE TO HIGHER ELEVATIONS AND THE BULK OF THE PRECIPITATION FALLING AFTER MIDNIGHT. LOOKS LIKE RAIN WILL CHANGE OVER TO SNOW THIS EVENING ABOVE 5500FT ACROSS NORTHERN ELKO COUNTY...WITH RAIN CHANGING OVER TO SNOW FROM AUSTIN TO SPRING CREEK SOMETIME AFTER MIDNIGHT AS 1000-500MB THICKNESS VALUES FALL BELOW 549DAM. 700MB FGEN FORCING PEAKS FROM AUSTIN TO ELKO AROUND 9Z...BEFORE SLIDING INTO EASTERN ELKO AND WHITE PINE COUNTIES BY SUNDAY MORNING. EXPECTING A MODERATE SNOW- BAND TO DEVELOP ALONG THIS FGEN FORCING AS IT IS VERTICALLY STACKED WITH A BROAD AREA OF 500-300MB UPPER LEVEL LIFT DUE TO A DUAL-CORE JET STREAK CIRCULATION. THIS WILL LEAD TO VERY DEEP LIFT AND A VERY FAVORABLE DENTRITIC GROWTH REGION...THUS EXPECTING HIGH END ADVISORY SNOWFALL AMOUNTS ABOVE 6K WHERE IT WILL BE COLD ENOUGH FOR 12 TO 1 SNOW RATIOS. BELOW 5500 FEET SURFACE TEMPS WILL LEAD TO LOW RATIOS...THUS LOWER SNOWFALL AMOUNTS...BUT A SLUSHY INCH COULD EVEN FALL IN ELKO. THE HIGHEST AMOUNTS OF SNOW IN POPULATED AREAS ARE EXPECTED AT AUSTIN...EUREKA...SPRING CREEK...AND ELY. SUNDAY NIGHT THROUGH TUESDAY. SNOW TAPERS OFF DURING THE DAY ON SUNDAY...BEFORE THE NEXT PACIFIC STORM REACHES THE AREA BY MONDAY AFTERNOON. MODELS HAVE BEEN STRUGGLING WITH THIS SYSTEM...DUE TO THE EVOLUTION OF TWO SEPARATE 500MB CIRCULATIONS. CONFIDENCE IS STILL LOW IN HOW THIS SYSTEM WILL MATERIALIZE OVER THE REGION...BUT WET SNOW IS PROBABLE MONDAY NIGHT INTO TUESDAY MORNING AS A SURFACE LOW DEVELOPS OVER NORTHERN NEVADA AND 500MB HEIGHTS DROP TO 546 DAM. THE BEST CHANCE FOR HEADLINE LEVEL SNOWFALL LOOKS TO BE ACROSS NORTHERN NEVADA AT THIS TIME. LONG TERM...TUESDAY NIGHT THROUGH NEXT SATURDAY. EMPHASIS ON SHORT TERM AND IMPACTS TO AVIATION, SO FEW CHANGES WERE MADE TO THE LONG TERM GRIDS. LARGE COLD TROUGH LINGERS OVER THE GREAT BASIN TUESDAY NIGHT AND WEDNESDAY, FOR UNSEASONABLY COLD WEATHER FOR EARLY APRIL AND SCATTERED SNOW SHOWERS. ADDITIONAL SNOW AMOUNTS DURING THIS TIME FRAME WILL BE LIGHT, WITH THE LARGEST IMPACT BEING THE COLD. WITH 700 MB TEMPS NEAR -10C, AFTERNOON TEMPERATURES WILL STRUGGLE INTO THE 40S WEDNESDAY, AND NW WINDS WILL MAKE IT FEEL EVEN COLDER. TEMPERATURES WILL MODERATE THURSDAY UNDER WEAK RIDGING, AHEAD OF THE NEXT PACIFIC TROUGH. 12Z ECMWF BRINGS THIS PACIFIC TROUGH INLAND INTO NEVADA IN A WEAKENED STATE ON FRIDAY, WITH SOME RAIN AND SNOW SHOWERS. 12Z GFS MUCH FASTER AND MUCH WEAKER WITH THIS WAVE, IN FACT MEDIUM RANGE SOLUTIONS OF GFS/ECMWF/GEM ARE IN MUCH DISAGREEMENT STARTING ABOUT THURSDAY. SHOWED A GRADUAL WARMING TREND IN THE MAX TEMP GRIDS FRIDAY AND SATURDAY, BUT CONFIDENCE IS LOW. BT AVIATION...FOR THE 00Z TAFS...COMPLICATED TAF PACKAGE, WITH SNOW AND WIND IMPACTING AVIATION OPERATIONS THROUGH THE NEXT 24 HOURS. MODEL GUIDANCE AGREES THAT INCLEMENT WEATHER WILL OCCUR AT THE TAF SITES, BUT DIFFER A BIT ON TIMING /WITH THE 12Z GFS A BIT SLOWER/ SO WILL HOLD OFF ON TEMPO GROUPS UNTIL THE EVENT STARTS TO UNFOLD THIS AFTERNOON/EVENING. EXPECT DEGRADED CONDITIONS IN -RA TO BEGIN AT KWMC AROUND 00Z, AND AT KEKO AROUND 03Z. EXPECTING -RA TO CHANGE TO -SN AT BOTH KWMC/KEKO APPROXIMATELY 06Z TONIGHT, WITH VIS/CIG MOST LIKELY FALLING TO IFR/CAT A LANDING MINIMUMS AT KEKO 06-15Z SUN. STRONG COLD FRONT WILL REACH KWMC BY 09Z, AND KEKO BY 12Z, WITH STRONG NW WINDS GUSTING 30-35 KTS AND LIMITED VIS IN -SHSN. SINCE MOST OF THE SNOW IS FALLING AT NIGHT AT KEKO, SOME ACCUMULATIONS ON KEKO RUNWAYS ARE POSSIBLE 06-15Z SUN. FURTHER SOUTH...CYCLOGENESIS EXPECTED NEAR KELY AFTER 00Z, WITH STRONG SW/S WINDS GUSTING 30-40 KTS AT TIMES, AT LEAST THROUGH 06Z. INCLUDED VCTS AT KELY THIS EVENING WITH INSTABILITY PRESENT. STRONG COLD FRONT PASSAGE APPROXIMATELY 12-15Z SUN, WITH AGAIN STRONG NW WINDS OF 20-35 KTS. ACCUMULATING SNOW MOST LIKELY AT KELY 12-18Z SUN, WITH IMPACTS POSSIBLE ON KELY RUNWAYS. AT KTPH...STRONG SW WINDS THIS AFTERNOON AT 20-30 KTS. COLD FRONT ARRIVES AT KTPH AROUND 12Z SUN, WITH VERY STRONG NW WINDS FOLLOWING ITS PASSAGE AT THE KTPH TERMINAL, GUSTING TO 40-45 KTS. LIMITED VIS IN BRIEF -RASN MOST LIKELY AT KTPH 12-18Z SUN, BUT IMPACTS WILL BE MUCH LESS HERE COMPARED TO THE OTHER TERMINALS. BT && .LKN WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 5 PM PDT SUNDAY ABOVE 5500 FEET FOR NORTHERN ELKO COUNTY...NORTHERN LANDER COUNTY AND NORTHERN EUREKA COUNTY...SOUTHWESTERN ELKO COUNTY. WINTER WEATHER ADVISORY UNTIL 5 PM PDT SUNDAY ABOVE 6000 FEET FOR SOUTH CENTRAL ELKO COUNTY...SOUTHERN LANDER COUNTY AND SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY. WINTER STORM WARNING UNTIL 5 PM PDT SUNDAY FOR RUBY MOUNTAINS/EAST HUMBOLDT RANGE. WIND ADVISORY FROM 5 AM TO 5 PM PDT SUNDAY FOR NORTHWESTERN NYE COUNTY. && $$ 93
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
854 PM EDT SAT MAR 29 2014 .SYNOPSIS... A MOISTURE LADEN STORM SYSTEM WILL IMPACT OUR REGION TONIGHT INTO SUNDAY. THIS SYSTEM WILL PRODUCE A MIXTURE OF RAIN...SLEET AND SNOW...WITH SOME ICE ACCUMULATION ACROSS PORTIONS OF EASTERN VERMONT. HEAVY RAINFALL ACROSS SOUTHERN VERMONT...COMBINED WITH MELTING SNOW WILL PRODUCE INCREASED HYDRO CONCERNS OVER THE WEEKEND. && .NEAR TERM /THROUGH SUNDAY/... AS OF 840 PM EDT SATURDAY...UPDATED TO UPGRADE PARTS OF THE NORTHERN ADIRONDACK MOUNTAINS TO WINTER STORM WARNINGS. PRECIPITATION HAS NOW MADE IT INTO PORTIONS OF SOUTHERN VERMONT...ADIRONDACKS...AND INTO WATERTOWN NEW YORK. SHOULD CONTINUE TO SEE IT MOVE NORTHWARD INTO CENTRAL VERMONT BETWEEN 9-10 PM...THE BURLINGTON AREA 10-11 PM..AND ACROSS THE ENTIRE NORTH COUNTRY BY MIDNIGHT. HEAVIEST PRECIP STILL APPEARS IT WILL FALL BETWEEN 06Z AND 12Z. VERTICAL TEMPERATURE PROFILES REMAIN VERY TRICKY WITH NEARLY ISOTHERMAL PROFILE FROM THE SURFACE TO 825-MB CENTERED AROUND 0C. DYNAMIC/EVAPORATIONAL COOLING SHOULD HELP TO COOL THE COLUMN AT LEAST IN HEAVIER PRECIPITATION IN THE ADVISORY AND WARNING AREA...ESPECIALLY NORTHERN NEW YORK. ONE CAVEAT TO NOTE...LATEST RAP SOLUTIONS ARE CONSIDERABLY WARMER AND WOULD FAVOR MORE RAIN OVER SNOW/SLEET FOR MUCH OF VERMONT. STILL THINK THAT ENOUGH COOLING TO TAKE PLACE FOR A GENERAL 2-5" OF SNOW FOR THE NORTHERN HALF OF VERMONT. IN THE ADIRONDACKS...TEMPERATURES HAVE ALREADY FALLEN TO 32 DEGREES OR LOWER...WITH LOW LEVEL COLD NORTHEAST FLOW LOCKED IN. WITH AT LEAST 0.75" OF LIQUID EQUIVALENT PRECIPITATION HEADED INTO SUB-FREEZING AIR...FELT IT WAS NECESSARY TO UPGRADE TO WARNINGS THERE. EVEN THE WARMER RAP SOLUTIONS ARE COLD ENOUGH FOR ALL FROZEN PRECIPITATION OVER THE ADIRONDACKS. EXPECTING PRIMARILY SNOW...ALTHOUGH THE TEMPERATURE PROFILE IS STILL QUITE MARGINAL SO SOME SLEET/RAIN/FREEZING RAIN MIX STILL LIKELY AT TIMES. LOOKING AT 4-8" THERE WITH THE POSSIBILITY OF SOME LOCALLY HIGHER AMOUNTS. COLD NORTHEAST WINDS ALSO LOCKED INTO THE SAINT LAWRENCE VALLEY...BUT BOUNDARY LAYER WILL BE MORE MARGINAL AS ITS A DEEPER VALLEY...AND PRECIP AMOUNTS LIGHTER...SO ADVISORY LEVEL SNOWS OF 3-5" STILL LOOK GOOD. ELSEWHERE ACROSS SOUTHERN VERMONT...PRECIPITATION WILL FALL AS MAINLY RAIN...WITH SOME MIXED SNOW/SLEET/FREEZING RAIN. SNOW ACCUMULATIONS WILL GENERALLY BE LESS THAN ONE INCH...WITH SOME ICE ACCRUAL OF UP TO A TENTH OF AN INCH IN ISOLATED LOCATIONS. BIGGEST CONCERN THERE WILL BE 1-1.5" OF RAIN WHICH MAY LEAD TO ICE JAM FLOODING. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... AS OF 402 PM EDT SATURDAY...FOR SUNDAY NIGHT INTO MONDAY...WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ANOTHER ROUND OF MIXED PRECIPITATION. THIS DUE TO SHORTWAVE ROTATING AROUND THE SLOWLY DEPARTING UPPER LOW. MODELS HAVE TRENDED FURTHER WEST WITH THE UPPER LOW AND SHORTWAVE...SO CONFIDENCE INCREASING THAT WE WILL AT LEAST SEE SOME LIGHT SLEET AND OR RAIN/FREEZING RAIN/DRIZZLE SUNDAY NIGHT INTO MONDAY. GREATEST CHANCES WILL BE OVER EASTERN ZONES DUE PROXIMITY WITH UPPER LOW. TEMPS MARGINAL FOR SNOW/RAIN OR MIXED PRECIPITATION ONCE AGAIN. LOOK FOR LOWS SUNDAY NIGHT IN THE MID 20S TO LOWER 30S AND HIGHS MONDAY NEAR 40. SLOW IMPROVEMENT MONDAY NIGHT AS THE UPPER LOW EXITS TO THE EAST. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 325 PM EDT SATURDAY...DRY START TO THE PERIOD TUESDAY BEFORE UPPER LVL TROUGH...ASSOCIATED WITH CLOSED SFC LOW...TRAVELS FROM THE NRN GREAT LAKES NEWD NEAR JAMES BAY BY MID WEDNESDAY. THIS LOW WILL HAVE A WEAK FRONTAL BOUNDARY DRAPED SOUTH...WHICH WILL BRING LOW CHC OF SHOWERS TO THE NORTH COUNTRY TUESDAY NGT INTO WEDNESDAY...AS THIS BOUNDARY WILL HAVE LIMITED MOISTURE AND MAIN UPPER LVL ENERGY WILL BE FAR NORTH OF THE FA. FOR ANY PRECIP THAT DOES OCCUR...TUESDAY NGT WILL SEE SOME SNOW...BUT WARMING TEMPS ON WEDNESDAY WILL TRANSITION SN INTO RA BEFORE TAPERING OFF. ANOTHER SYSTEM APPROACHING FROM CENTRAL USA WILL BRING WARM FRONT TO THE NE LATE THURSDAY INTO FRIDAY. GFS AND ECMWF DIFFER WITH ECMWF PERSISTING WITH RIDGE. THIS WOULD KEEP THREAT OF PRECIP TO OUR SOUTH THRU LATE FRIDAY. MUCH UNCERTAINTY FOR THE LATTER HALF OF THE WEEK GOING INTO THE WKND. TEMPS THROUGHOUT THE PERIOD WILL BE NEAR NORMAL WITH MAX TEMPS IN THE 40S IN THE VALLEYS AND 30S IN THE MTNS. MIN TEMPS WILL BE IN THE U20S-L30S IN THE VALLEYS AND UPPER TEENS TO L20S IN THE MTNS. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... THROUGH 00Z MONDAY...VERY ACTIVE PERIOD WITH AVIATION WX CONDITIONS DETERIORATING RAPIDLY THIS EVENING AND OVERNIGHT. IFR CONDITIONS DEVELOP AREAWIDE BETWEEN 02-05Z IN ASSOCIATION WITH MODERATE TO HEAVY MIXED WINTRY PCPN MOVING IN FROM THE SOUTH. NY TERMINALS ARE IN COLDER AIR MASS...AND WILL SEE MORE SNOW/SLEET. IN VT...MIX OF HEAVY WET SNOW/SLEET/RAIN IS EXPECTED THRU MID-MORNING SUNDAY WITH TEMPS IN THE LOW-MID 30S. SFC WINDS WILL BE N-NE AT 10-15KTS...EXCEPT LOCALLY 15-20KTS WITH VALLEY CHANNELING EFFECTS AT MSS. SLUSHY SNOW/SLEET ACCUMULATION WILL CAUSE IMPACT TO AIRPORT GROUND OPS ALL SITES 02-15Z SUNDAY. PRECIPITATION WINDS DOWN W-E SUNDAY AFTN WITH IMPROVEMENT TO MVFR CIGS. OUTLOOK 00Z MONDAY THROUGH THURSDAY... 00Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO EAST AS LIGHT RAIN/SNOW TAPERS OFF. BEST SHOT AT CONTINUED LIGHT PCPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH CONTINUED UNCERTAINTY FURTHER EAST. 18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE. 00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD FRONT CROSSES REGION. 00Z THURSDAY ONWARD...VFR W/MVFR PSBL LATE THURSDAY AS WARM FRONT APPROACHES FROM SW...BRINGING PRECIP SOUTH TO NORTH. && .HYDROLOGY... AS OF 325 PM EDT SATURDAY...PRECIPITATION WILL BEGIN TO EDGE INTO SOUTHERN VERMONT LATE THIS AFTN...PROGRESSING NORTHWARD THROUGHOUT THE EVENING. THIS PRECIPITATION IS EXPECTED TO CONTINUE THROUGH SUNDAY NIGHT...RESULTING IN OUR SOUTHERN WATERSHEDS RECEIVING THE MOST RAINFALL ON THE ORDER OF 1-2 INCHES. AREAS FURTHER NORTH AND WEST WILL SEE MORE OF A MIXED PRECIPITATION EVENT...WITH LESSER RAINFALL AMOUNTS. WITH SOUTHERN WATERSHEDS RECEIVING MOSTLY RAIN...EXPECT SNOWPACK TO ABSORB SOME OF THIS RAINFALL AS TEMPERATURES WILL GENERALLY BE IN THE MID TO UPPER 30S THROUGHOUT THE EVENT...LEADING TO LIMITED MELTING OF SNOWPACK. ONLY A FEW HUNDREDTHS OF AN INCH OF SNOW WATER MELT PER HOUR EXPECTED ON TOP OF RAINFALL WILL RESULT IN MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET SUNDAY MORNING/AFTERNOON. ENSEMBLE FORECASTS INDICATE NO RIVER FLOODING EXPECTED....BUT WATER LEVEL RISES MAY BE MORE THAN SUFFICIENT TO PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS. WILL KEEP FLOOD WATCH IN EFFECT FOR CENTRAL AND SOUTHERN VERMONT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER WEATHER ADVISORY UNTIL 2 PM EDT SUNDAY FOR VTZ001>010- 012-016>019. FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019. NY...WINTER STORM WARNING UNTIL 2 PM EDT SUNDAY FOR NYZ030-031-034. WINTER WEATHER ADVISORY UNTIL 2 PM EDT SUNDAY FOR NYZ026>029- 035-087. && $$ SYNOPSIS...RJS NEAR TERM...MUCCILLI SHORT TERM...RJS LONG TERM...KGM AVIATION...BANACOS/KGM HYDROLOGY...KGM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
921 PM EDT SAT MAR 29 2014 .SYNOPSIS... A COLD FRONT WILL MOVE OFFSHORE LATE TONIGHT. A SURFACE TROUGH WILL LINGER JUST WEST OF THE AREA INTO MONDAY. WEAK HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND TUESDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY. ANOTHER COLD WILL APPROACH THE AREA BY LATE WEEK. && .NEAR TERM /THROUGH SUNDAY/... AS OF 920 PM SATURDAY...A TORNADO WATCH REMAINS IN EFFECT FOR THE WESTERN PORTIONS OF EASTERN NC (MAINLY WEST OF HIGHWAY 17) UNTIL 1 AM. HAVE BEEN WATCHING A PERSISTENT SUPERCELL THUNDERSTORM WITH A DEEP AND PERSISTENT MESCALINE MOVING THROUGH CENTRAL NC SINCE 730 PM. THIS STORM WILL REMAIN NW OF OUR AREA. TO THE SOUTH OF THIS SYSTEM ADDITIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WERE DEVELOPING. THE HRRR MODEL BRINGS THIS CONVECTION INTO OUR PORTION OF THE COASTAL PLAIN AROUND 11 PM SO WILL CONTINUE TO MONITOR. SO FAR STORMS HAVE NOT WEAKENED WITH LOSS OF HEATING A SIGNAL THAT THEY ARE BEING DYNAMICALLY FORCED. WILL CONTINUE TO KEEP POPS IN THE CHANCE RANGE AS THE COVERAGE IN THE HIGH RESOLUTION MODELS REMAINS SCATTERED. LATE TONIGHT DRY SLOTTING SHOULD END ANY CHANCE OF PRECIPITATION UNTIL LATER SUNDAY WHEN THE UPPER LEVEL LOW MOVES THROUGH. USED A BLEND OF THE ECMWF/MET MOS FOR LOWS WITH READINGS IN THE UPPER 40S/LOWER 50S EXPECTED. && .SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/... AS OF 315 PM SATURDAY...WILL HAVE A BIT OF A LULL IN PRECIPITATION DURING THE MORNING HOURS ON SUNDAY...BUT AS UPPER LOW CROSSES TO OUR NORTH NEAR THE NORTH CAROLINA/VIRGINIA BORDER...THE STEEP LAPSE RATES AND MODEST MOISTURE WILL LEAD TO A HIGH CHANCE OF SHOWERS SUNDAY AFTERNOON. WITH GOOD COLD AIR ADVECTION...TEMPERATURES WILL ONLY RECOVER ABOUT 5 TO 7 DEGREES AND WILL FOLLOW THE COOLER NAM MOS GUIDANCE SUNDAY SHOWING HIGH TEMPERATURES IN THE LOW/MID 50S WITH GUSTY W/WNW WINDS. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... AS OF 3 PM SAT...THE LONG TERM PORTION OF THE FORECAST CAN BE SUMMARIZED AS DRYING OUT AND WARMING UP. MADE ONLY MINOR TWEAKS TO THE POPS ENDING THE RAIN SUNDAY NIGHT. SURFACE/UPPER LOW AND ASSOCIATED MOISTURE MOVE OFF TO THE NORTHEAST WITH RIDGING SURFACE AND ALOFT BUILDING IN FROM THE WEST. RIDGING BEGINS TO BREAK DOWN LATE IN THE WEEK AS AN UPPER LOW AND SURFACE COLD FRONT APPROACH FROM THE WEST. THE COLD FRONT WILL MOVE THROUGH FRIDAY NIGHT AND CARRIED A LOW CHANCE POP FOR SHOWERS AND STORMS. DRYING OUT SATURDAY WITH THE FRONT OFF THE COAST AND A SURFACE HIGH BUILDING TO THE NORTHWEST. NORTHWEST FLOW ON MONDAY WILL DIMINISH AND SLOWLY TRANSITION TO A WEST TO SOUTHWEST FLOW BY TUESDAY NIGHT AND CONTINUE INTO FRIDAY. HIGHS THIS WEEK WILL CLIMB WELL INTO THE 70S ACROSS MOST INLAND AREAS BEGINNING TUESDAY AS WINDS BECOME SOUTHERLY. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... SHORT TERM /TONIGHT AND SUNDAY/... AS OF 640 PM SATURDAY...SOME IFR CEILINGS ARE STILL BEING REPORTED AT THE TAF SITES BUT THINK THE TREND IS FOR IMPROVEMENT AS THE THREAT FOR WIDESPREAD PRECIPITATION IS OVER AND SOME DRYING IS EXPECTED TO MOVE INTO THE AREA LATER THIS EVENING. BASED ON UPSTREAM OBSERVATIONS AND TRENDS IN THE 12Z/18Z NAM FORECAST SOUNDINGS WILL FORECAST CONDITIONS IMPROVING TO MVFR AND CONTINUING FOR MUCH OF TONIGHT THEN A BRIEF PERIOD OF VFR CONDITIONS AROUND 09Z DURING THE PEAK OF DRYING. AN UPPER LOW IS FORECAST TO MOVE ACROSS NC SUNDAY. ASSOCIATED MOISTURE WILL LEAD TO A RETURN TO MVFR CEILINGS 12-14Z WHICH WILL THEN PERSIST FOR MUCH OF THE DAY. THERE COULD ALSO INTERMITTENT LIGHT RAIN OR DRIZZLE AT TIMES. GUSTY SOUTHERLY WINDS TONIGHT WILL BECOME WESTERLY ON SUNDAY. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 3 PM SAT...IFR/MVFR CONDITIONS SUNDAY NIGHT WILL BECOME VFR ON MONDAY AS MOISTURE EXITS TO THE NORTHEAST AND A SURFACE/UPPER RIDGE BUILDS IN FROM THE WEST. NORTHWEST WINDS SUNDAY NIGHT AND MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT AND CONTINUE THROUGH THURSDAY. MODEL SOUNDINGS INDICATE LATE NIGHT/EARLY MORNING STRATUS/FOG POSSIBLE EACH MORNING WITH VERY LIGHT WINDS AND BOUNDARY LAYER MOISTURE. && .MARINE... SHORT TERM /TONIGHT AND SUNDAY/... AS OF 920 PM SATURDAY...NO CHANGES TO PREVIOUS FORECAST THINKING OTHER THAN TO EXTEND THE ADVISORIES FOR THE SOUNDS THROUGH EARLY MONDAY. GUSTY SE/S WINDS WILL CONTINUE TONIGHT AND HAVE ADDED THE ALBEMARLE SOUND TO THE SMALL CRAFT ADVISORY THAT WILL REMAIN IN EFFECT UNTIL 5 AM SUNDAY. WILL INITIALIZE WINDS AT 20 TO 25 KNOTS FOR ALL WATERS...EXCEPT 25 TO 30 KNOTS OVER THE OREGON INLET TO OCRACOKE LEG WHERE WINDS CONTINUE TO BE STRONGEST. THESE WINDS SHOULD SETTLE DOWN AFTER MIDNIGHT AS WINDS VEER TO MORE SW LATE. PER LATEST NWPS WAVE MODEL...SEAS OF 9 TO 13 FEET WILL PREVAIL OVER THE NORTHERN AND CENTRAL WATERS WITH GENERALLY 7 TO 10 FEET OVER SOUTHERN PORTIONS...WITH A SLIGHT DROP IN THE MORE WESTERLY FLOW EXPECTED DURING THE DAY ON SUNDAY. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 3 PM SAT...AN OVERALL IMPROVING TREND SEEN IN MARINE CONDITIONS THROUGH THE LONG TERM. SURFACE/UPPER LOW WILL MOVE OFF TO THE NORTHEAST SUNDAY NIGHT WITH SURFACE/UPPER RIDGE QUICKLY BUILDING IN AND LINGERING FOR MOST OF THE WEEK. SMALL CRAFT CONDITIONS WILL END FROM SOUTH TO NORTH MONDAY AND MONDAY NIGHT. NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT THROUGH THURSDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ130-135. SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ156-158. SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR AMZ150. && $$ SYNOPSIS...CTC NEAR TERM...CTC/JME SHORT TERM...CTC LONG TERM...HSA AVIATION...JME/HSA/LEP MARINE...CTC/JME/HSA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
348 PM EDT FRI MAR 28 2014 .SYNOPSIS... A SLOW-MOVING COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT. DEVELOPING LOW PRESSURE MOVING ACROSS TO THE NORTH WILL PULL THE FRONT THROUGH THE AREA LATE SATURDAY INTO SATURDAY NIGHT. THE LOW WILL CONTINUE DEEPENING AS IT MOVES TO THE NORTHEAST SUNDAY AND SUNDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE WEST THROUGH MONDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY. ANOTHER COLD FRONT WILL APPROACH THE AREA BY FRIDAY OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 345 PM FRIDAY...LOW-LEVEL MOISTURE TRANSPORT AND PRECIPITABLE WATER VALUES CONTINUE TO CREEP UP ACROSS THE CENTRAL PART OF THE STATE AHEAD OF SLOW-MOVING COLD FRONT IN THE TENNESSEE VALLEY. RADAR SHOWING SOME LIGHT SHOWERS GRADUALLY MOVING INTO THE COASTAL PLAINS...WHICH IS WELL DEPICTED BY THE LATEST 4 KM NSSL WRF AND RAP MODELS. THE ATMOSPHERE IS STABLE AND DO NOT EXPECT THUNDER THROUGH MOST OF THE OVERNIGHT HOURS. HAVE TRENDED POPS INTO THE LIKELY RANGE...MAINLY AFTER MIDNIGHT AS THE PRECIPITATION INCREASES AND MOVES EAST. WITH THE INCREASED CLOUDS...PRECIP AND SOUTHERLY WINDS...MINIMUM TEMPERATURES TONIGHT WILL BE VERY MILD...REMAINING MAINLY IN THE UPPER 50S TO AROUND 60 DEGREES. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... AS OF 345 PM FRIDAY...WIDESPREAD SHOWERS WILL COVER THE CWA ON SATURDAY AND CONTINUE THE FORECAST OF CATEGORICAL POPS...WITH SOME EMBEDDED THUNDERSTORMS. SPC CONTINUES TO HAVE OUR CWA IN A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR SATURDAY. EXPECT MORNING CLOUDINESS AND SHOWERS TO LIMIT THE INSTABILITY DURING THE FIRST HALF OF THE DAY...BUT WITH BETTER DIRECTIONAL SHEAR AND LI`S OF -2 TO -4 LATE IN THE DAY...THINK THE POTENTIAL FOR ANY SEVERE WEATHER WILL BE BETTER...ESPECIALLY IN THE 20Z-02Z TIME FRAME. DAMAGING WINDS GUSTS WILL BE THE MAIN THREAT AND GIVEN THE BACKED LOW-LEVEL FLOW...CANNOT RULE OUT A BRIEF TORNADO. TEMPERATURES WILL WARM INTO THE MID 60S OUTER BANKS TO MID 70S INLAND...DESPITE THE CLOUD COVER...GIVEN GUSTY SOUTHERLY WINDS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 3 PM FRI...GFS/ECMWF IN RATHER GOOD AGREEMENT FOR MOST OF THE LONG TERM. WIDESPREAD SHOWERS AND STORMS SATURDAY NIGHT WILL SLOWLY TAPER OFF FROM THE WEST AFTER MIDNIGHT AS THE COLD FRONT MOVES EAST. NO CHANGES TO POPS. FRONT WILL MOVE OFF THE COAST SHORTLY AFTER 12Z SUNDAY. PLENTY OF WRAPAROUND MOISTURE ON SUNDAY SO EXPECT CLOUDS AND SCATTERED SHOWERS TO CONTINUE THROUGH THE DAY WITH THE BEST CHANCE ACROSS THE NORTHEAST COUNTIES. SHOWERS WILL FINALLY END SUNDAY EVENING AS THE UPPER LOW AND DEEP MOISTURE MOVE AWAY. UPPER LEVEL RIDGING WILL BE DOMINANT NEXT WEEK...WHILE AT THE SURFACE HIGH PRESSURE OVER THE SOUTHEAST MONDAY SHIFTS EAST AND REMAINS OFF THE COAST THROUGH THE END OF THE WEEK...MAKING FOR A PERIOD OF DRY AND WARM WEATHER FOR THE AREA. THE NEXT CHANCE OF RAIN COMES WITH THE NEXT FRONT APPROACHING ON FRIDAY. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /TONIGHT AND SATURDAY/... AS OF 115 PM FRIDAY...VFR CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON WITH SUB-VFR FORECASTED THIS EVENING THROUGH TOMORROW. A POTENT LOW PRESSURE SYSTEM WILL BE APPROACHING THE REGION FROM THE WEST. THEREFORE...EXPECT CLOUDS TO INCREASE/LOW THROUGH THE LATE AFTERNOON/EVENING HOURS. GUSTY SOUTHERLY FLOW WILL CONTINUE FOR THE NEXT COUPLE OF HOURS BUT SUBSIDE AS THE SURFACE HEATING DIMINISHES. RAIN SHOULD ARRIVE THIS EVENING THROUGH THE OVERNIGHT HOURS WITH VSBYS LOWERING IN RESPONSE. ANTICIPATE MAINLY MVFR AND SOME PATCHY IFR CIGS/VSBYS THROUGH THE OVERNIGHT HOURS INTO SATURDAY MORNING. SSE WINDS AROUND 5-10KTS EXPECTED SATURDAY. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 3 PM FRI...GFS/ECMWF IN RATHER GOOD AGREEMENT FOR MOST OF THE LONG TERM. WIDESPREAD SHOWERS AND STORMS SATURDAY NIGHT WILL SLOWLY TAPER OFF FROM THE WEST AFTER MIDNIGHT AS THE COLD FRONT MOVES EAST. NO CHANGES TO POPS. FRONT WILL MOVE OFF THE COAST SHORTLY AFTER 12Z SUNDAY. PLENTY OF WRAPAROUND MOISTURE ON SUNDAY SO EXPECT CLOUDS AND SCATTERED SHOWERS TO CONTINUE THROUGH THE DAY WITH THE BEST CHANCE ACROSS THE NORTHEAST COUNTIES. SHOWERS WILL FINALLY END SUNDAY EVENING AS THE UPPER LOW AND DEEP MOISTURE MOVE AWAY. UPPER LEVEL RIDGING WILL BE DOMINANT NEXT WEEK...WHILE AT THE SURFACE HIGH PRESSURE OVER THE SOUTHEAST MONDAY SHIFTS EAST AND REMAINS OFF THE COAST THROUGH THE END OF THE WEEK...MAKING FOR A PERIOD OF DRY AND WARM WEATHER FOR THE AREA. THE NEXT CHANCE OF RAIN COMES WITH THE NEXT FRONT APPROACHING ON FRIDAY. && .MARINE... SHORT TERM /TONIGHT AND SATURDAY/... AS OF 345 PM FRIDAY...HAVE EXTENDED THE SMALL CRAFT ADVISORY SOUTH OF OREGON INLET UNTIL 12Z ON SATURDAY MORNING. WINDS ARE RAMPING UP WITH GUSTS TO 20 KNOTS AT DUCK PIER...AND 25 KNOTS AT DIAMOND BUOY. SEAS CONTINUE TO HOVER AROUND 6 FEET AT DIAMOND SHOALS. EXPECT GUSTY SOUTHERLY WINDS AT 15 TO 20 KNOTS...EXCEPT UP TO 25 KNOTS AT TIMES OVER THE WATERS SOUTH OF OREGON INLET TONIGHT INTO SATURDAY. PER LATEST SWAN/NWPS...SEAS AS HIGH AS 6 TO 7 FEET ARE LIKELY...ESPECIALLY OVER THE CENTRAL WATERS TONIGHT AND EARLY SATURDAY. THERE WILL BE A LULL IN WINDS/SEAS DURING LATE MORNING INTO AFTERNOON SATURDAY. AN ADDITIONAL SMALL CRAFT ADVISORY WILL LIKELY BE REQUIRED LATER TONIGHT FOR ALL WATERS BEHIND THE STRONG FRONT SATURDAY NIGHT. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 3 PM FRI...GFS/ECMWF IN CLOSE AGREEMENT AND USED A BLEND. VERY POOR BOATING CONDITIONS TO START OUT THE LONG TERM WITH ONLY SLOW IMPROVEMENT THROUGH THE PERIOD. STRONG SMALL CRAFT WIND/SEA CONDITIONS TO BEGIN WITH ALONG AND AHEAD OF THE COLD FRONT. THE FRONT WILL MOVE OFF THE COAST AROUND 12Z SUNDAY. WINDS WILL VEER FROM SOUTHWEST SATURDAY EVENING TO WEST SUNDAY MORNING THEN TO NORTHWEST DURING THE DAY SUNDAY. SMALL CRAFT CONDITIONS WILL GRADUALLY END FROM SOUTH TO NORTH SUNDAY NIGHT INTO MONDAY NIGHT. HIGH PRESSURE OVER THE AREA MONDAY WILL SHIFT OFF THE SOUTHEAST COAST TUESDAY AND WEDNESDAY WITH LIGHT WEST TO SOUTHWEST WINDS AND SEAS AVERAGING 2-4 FEET. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR AMZ152-154- 156-158. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...HSA AVIATION...HSA/LEP MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
312 PM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY. TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 300 PM FRIDAY...A LARGE MCS ALONG THE EASTERN GULF COAST DOMINATES THE WEATHER PATTERN ACROSS THE SOUTHEASTERN U.S. THE CONVECTIVE ELEMENTS OF THIS FEATURE ARE LARGELY LIMITED TO SOUTHERN GEORGIA AND POINTS SOUTH...WITH AN EXPANSIVE BUT DETERIORATING AREA OF LIGHT RAIN EXTENDING INTO NORTH GEORGIA AND WESTERN SOUTH CAROLINA. THIS ACTIVITY SHOULD MOVE EASTWARD... AFFECTING THE SC PEE DEE REGION EARLY THIS EVENING. OTHER GENERALLY LIGHT SHOWERS DEVELOPING IN A WEAKLY UNSTABLE AIRMASS ACROSS THE EASTERN CAROLINAS MAY CONTINUE INTO THE EVENING HOURS AS WELL AS SMALL ELEVATED INSTABILITY IS MAINTAINED BY A SOUTHERLY FLOW ACROSS THE GULF STREAM OFF THE GEORGIA AND SOUTH CAROLINA COAST. THE UPPER LEVEL DISTURBANCE THAT HELPED KICK OFF THE GULF COAST MCS WILL TURN NORTHEASTWARD TONIGHT...APPROACHING THE EASTERN CAROLINAS LATE. WHILE A RENEWED BLOWUP OF CONVECTION IS NOT ANTICIPATED DUE TO MEAGER INSTABILITY...A DIFLUENT UPPER LEVEL PATTERN AND AN INCREASING NEGATIVE TILT TO THE TROUGH SHOULD ENHANCE RAIN/SHOWER POTENTIAL OVERNIGHT ALL THE WAY DOWN TO THE COAST. WHILE I CAN`T BRING MYSELF TO PUT 100 POPS IN THE FORECAST...80-90 PERCENT SEEMS APPROPRIATE. PRECIPITABLE WATER VALUES SHOULD GROW TO 1.5 INCHES AFTER MIDNIGHT. IN TERMS OF MODEL SOLUTIONS...IT IS INTERESTING TO SEE HOW THE MODELS HAVE HANDLED (OR MISHANDLED) TWO ASPECTS OF THE WEATHER TODAY. ONE IS THE RELATIVELY LIGHT WINDS OVER THE COASTAL WATERS... PARTICULARLY WHEN CONTRASTED TO THE RATHER BREEZY CONDITIONS EXPERIENCED INLAND TODAY. MOST SYNOPTIC GUIDANCE (PARTICULARLY THE GFS) HAS BEEN TOO STRONG WITH MARINE WIND SPEEDS ALL DAY. ALSO OF NOTE IS THE PERSISTENT AREA OF LIGHT SHOWERS THAT MOVED INTO GEORGETOWN THIS MORNING AND NOW COVERS BRUNSWICK COUNTY ACROSS WHITEVILLE INTO LUMBERTON AND ELIZABETHTOWN. THIS ACTIVITY HAS BEEN WELL-FORECAST BY THE HRRR AND NAM BUT NOT THE GFS. PREFERRED MODELS TONIGHT INCLUDE THE HRRR IN THE VERY NEAR-TERM...THEN THE 12Z NAM AND 12Z CANADIAN OVERNIGHT. WITH SOUTHERLY WINDS AND CLOUDS CONTINUING OVERNIGHT LOWS SHOULD ONLY FALL TO 59-60 INLAND WITH 57-58 NEAR THE BEACHES DUE TO WINDS BLOWING IN OFF THE COLDER NEARSHORE WATERS. THE NAM MOS GUIDANCE IS MUCH CLOSER TO MY IDEAS THAN THE GFS MOS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 300 PM FRIDAY...THE MAIN CHALLENGE CONTINUES TO CENTER AROUND THE COMPLEX STORM SYSTEM MOVING ACROSS THE SOUTHEAST. TIMING AND INTENSITY OF RAINFALL AND ASSOCIATED THUNDERSTORMS REMAIN THE MAIN ISSUES. I HAVE LEANED HEAVILY TOWARD THE GFS FOR THE LATEST UPDATES TO THE SHORT TERM. INITIALLY WE COULD HAVE A LARGE SWATH OF RAIN COMING OFF THE ATLANTIC. AFTER THIS...THERE SHOULD BE A LULL IF YOU WILL WITH SOME NVA IN THE WAKE OF THIS INITIAL FEATURE. THE MAIN SHORTWAVE FINALLY GETS ORGANIZED AND MOVES OFF TO THE EAST/NORTHEAST SATURDAY AFTERNOON WITH YET ANOTHER DEEP MOISTURE FEED FROM THE GULF OF MEXICO WITH THE ASSOCIATED COLD FRONT. I HAVE INCREASED POPS FOR LATE AFTERNOON ACROSS WESTERN AREAS AND THE EVENING HOURS FOR COASTAL SITES. SEVERE PARAMETERS REMAIN MARGINAL AND CONTINUE TO HINGE ON THE AMOUNT OF INSTABILITY THE IS ABLE TO DEVELOP. LARGE DIFFERENCES IN TEMPERATURE GUIDANCE WITH THE NAM/MET NUMBERS QUITE A BIT LOWER FOR DAYTIME HIGHS SATURDAY. I WOULD EXPECT ANY BREAKS AND THERE SHOULD BE AT LEAST A FEW WILL ALLOW HIGHS TO JUMP MORE TOWARD THE GFS/MAV NUMBERS. GUIDANCE TRENDS CLOSER SATURDAY NIGHT AND SUNDAY. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 300 PM FRIDAY...THE LONG TERM APPEARS TO OFFER RAIN-FREE WEATHER. AS FAR AS TEMPERATURES GO DAYTIME HIGHS WILL AVERAGE ABOUT A CATEGORY ABOVE CLIMO WHILST NIGHTTIME LOWS SHOULD BE EVEN MILDER. HIGH PRESSURE SLIDES INTO FLORIDA ON MONDAY KEEPING LOCAL WINDS RATHER LIGHT. MEANWHILE UPPER RIDGING BUILDS IN FROM THE WEST. TUESDAY THROUGH WEDNESDAY WILL SHIFT THE HIGH SLIGHTLY EASTWARD WHILE THE UPPER LEVEL WAVE FLATTENS. END RESULT WILL BE A SLIGHT BOLSTERING OF THE WARM ADVECTION INTO THE REGION. UPPER LEVEL AMPLITUDE WILL THEN INCREASE AGAIN THURSDAY INTO FRIDAY AS A STORM SYSTEM MOVES OUT OF THE ROCKIES AND DEVELOPS INTO THE PLAINS THURSDAY...MOVING INTO OHIO VALLEY COME FRIDAY. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... AS OF 18Z...QUITE A BIT OF UNCERTAINTY WITH RESPECT TO THE TIMING OF THE PRECIP...AS WELL AS CEILINGS OVERNIGHT. SOUTHERLY GRADIENT WILL CAUSE WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE COAST. SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD LIGHT TO MODERATE RAIN THIS EVENING AS DEEP MOISTURE MOVES INTO THE REGION. RAIN CHANCES WILL BE HIGHEST INLAND THIS EVENING...SPREADING TO THE COAST A FEW HOURS LATER. CEILINGS ARE A BIT PROBLEMATIC...BUT WILL GO FOR MVFR PREDOMINATELY WITH POCKETS OF IFR POSSIBLE. TIME HEIGHT INDICATES THERE MAY BE A LULL IN THE PRECIP OF ABOUT 6-7 HOURS THROUGH THE LATE OVERNIGHT HOURS. SATURDAY...MODERATE TO PERHAPS HEAVY PRECIP SPREADING FROM WEST TO EAST. AN EMBEDDED THUNDERSTORM CANNOT BE RULED OUT. IN FACT...IF WE GET SOME CAPE WE COULD HAVE A FEW STRONGER STORMS IN THE AFTERNOON INTO EARLY EVENING. AGAIN CEILINGS PREDOMINATELY MVFR. EXTENDED OUTLOOK...BECOMING VFR SATURDAY NIGHT. SLIGHT CHANCE FOR SHOWERS AND MVFR CEILINGS OVER THE NORTHERN PORTION OF THE CWA. OTHERWISE VFR THROUGH WEDNESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM FRIDAY...SOUTH WINDS SHOULD CONTINUE OVERNIGHT AS THE CAROLINAS ARE IN BETWEEN HIGH PRESSURE WELL OFFSHORE AND AN APPROACHING COLD FRONT OVER THE MISSISSIPPI VALLEY. THE GFS MODEL HAS BEEN TOO STRONG WITH WIND SPEEDS ALL DAY...BUT A COMBINATION OF THE 12Z NAM AND CANADIAN MODELS SEEMS LIKE A GOOD FIT. SOUTH WINDS 10-15 KNOTS WILL RAISE A SHORT-PERIOD WIND WAVE...BUT STRONGER WINDS OFFSHORE WILL CREATE LARGER WAVES THAT WILL PUSH WESTWARD INTO THE COASTAL WATERS AS WELL. THE COMBINATION SHOULD CREATE 4-6 FOOT SEAS WITH A 6 SECOND DOMINANT PERIOD...AND A SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR THIS. WAVES OF SHOWERS ARE EXPECTED ACROSS THE WATERS...WITH HEAVIER ACTIVITY POSSIBLE OVERNIGHT. PM FRIDAY... SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 PM FRIDAY...FAIRLY BRISK CONDITIONS WILL PREVAIL OVER THE WATERS THROUGH THE PERIOD. FOR SATURDAY...A SOUTHERLY FLOW OF 15-20 KNOTS WILL BE IN PLACE AS LOW PRESSURE AND A COLD FRONT EDGE CLOSER FROM THE WEST. THIS FRONT CROSSES THE WATERS BETWEEN 0600 AND 1200 UTC SUNDAY. WINDS WILL TURN FROM THE WEST AND INCREASE TO 20-25 KNOTS. WITH COLD AIR ADVECTION DEVELOPING SUNDAY...THE WINDS WILL REMAIN ELEVATED BUT HOPEFULLY NOT THE LEVEL WE SAW EARLIER IN THE WEEK TO GALE CRITERIA. BY MONDAY MORNING THERE IS A SLOW DECREASE TO AROUND 15 KNOTS. SIGNIFICANT SEAS WILL HOVER AROUND SMALL CRAFT CRITERIA AND I WILL GO AHEAD AND EXTEND THE ADVISORY TO COVER SATURDAY AND SATURDAY NIGHT. THE CHANGE IN FETCH SHOULD EVENTUALLY ALLOW THE ADVISORY TO EXPIRE SUNDAY. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM FRIDAY...MONDAY STARTS WITH A MODERATE NW FLOW A RESULT OF BOTH DEEPENING STORM MOVING UP THE MIDATLANTIC COAST AND HIGH PRESSURE BUILDING IN FROM THE WEST. AS BOTH PROGRESS EASTWARD THE LOCAL GRADIENT SHOULD REALLY EASE AS THE DAY WEARS ON AND BY MONDAY NIGHT THERE MAY BE A LIGHT ENOUGH GRADIENT FOR A TRUE LIGHT AND VARIABLE WIND. TUESDAY INTO WEDNESDAY THE HIGH TAKES A MORE OFFSHORE POSITION GENERATING A LIGHT S TO SW FLOW LOCALLY. SEAS BUILD FROM THEIR MINIMAL MONDAY NIGHT VALUES TO ABOUT 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SUNDAY FOR AMZ250-252-254- 256. && $$ SYNOPSIS...SHK NEAR TERM...TRA SHORT TERM...SHK LONG TERM...MBB AVIATION...TRA/DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
128 PM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATER THIS AFTERNOON AND THEN STALL TO THE NORTH TONIGHT. DEVELOPING LOW PRESSURE MOVING ACROSS TO THE NORTH WILL PULL THE FRONT THROUGH THE AREA SATURDAY NIGHT. THE LOW WILL CONTINUE DEEPENING AS IT MOVES TO THE NORTHEAST SUNDAY AND SUNDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE WEST THROUGH MONDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1 PM FRIDAY...HAVE AGAIN RAISED MAXIMUM TEMPERATURES A COUPLE OF DEGREES AS MANY PLACES HAVE SOARED INTO THE LOWER 70S AND MID 70S ARE NOT OUT OF THE QUESTION OVER THE NEXT COUPLE OF HOURS. REMAINDER OF FORECAST REMAINS ON TRACK WITH SHOWERS MOVING INTO THE FAR WESTERN COUNTIES AROUND 21Z OR SO BASED ON 4 KM NSSL WRF AND RAP MODELS. INSTABILITY LACKING AND DO NOT EXPECT ANY THUNDER UNTIL SATURDAY AT THIS TIME. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... AS OF 430 AM FRIDAY...INCREASING MSTR AND SHRT WV ACTIVITY WILL PRODUCE HIGHER THREAT OF SHOWERS TONIGHT...WITH TSTM MENTION LIMITED TO COAST. GENERALLY CONTINUED PREVIOUS FCST OF POPS 50% COAST TO 70% INLAND THIS EVENING...AND 60%-70% ALL ZONES OVERNIGHT. SRLY FLOW AND CLOUD COVER WILL KEEP TEMPS MID 50S TO AROUND 60. && .LONG TERM /SATURDAY THROUGH FRIDAY/... AS OF 4 AM FRI...UNSETTLED PATTERN TO START THE LONG TERM PERIOD THIS WEEKEND...THEN DRY AND SEASONABLY WARM FOR NEXT WEEK. SHORT WAVE TROUGH ACROSS CENTRAL CONUS TODAY WILL AMPLIFY THROUGH SATURDAY AND CLOSE OFF A MID LEVEL VORT SAT EVENING. MODELS COMING IN BETTER AGREEMENT ON THIS SYNOPTIC SETUP AS WELL AS TIMING OF THE FEATURES. THE NEUTRAL TILT CLOSED LOW WILL PROMOTE SFC LOW DEVELOPMENT OVER CENTRAL NC SAT EVENING. AHEAD OF IT...INC SW LLJ WILL FURTHER INC MOISTURE ADVECTION INTO E NC. BNDRY LAYER STREAMLINES SUGGEST MOISTURE CONVERGENCE WILL BE MAXIMIZED SAT EVENING...WITH BEST CHANCE OF WIDESPREAD RAIN SHOWERS OCCURRING THEN. AHEAD OF THE SYSTEM...OCNL SHOWERS WITH EMBEDDED THUNDER WILL OCCUR DURING THE DAY SAT. GFS ENSEMBLES CLUSTER FAIRLY WELL WITH SFC LOW PLACEMENT ACROSS NC TO SOUTHERN VA BETWEEN 00Z AND 06Z SUN. THE 28/00Z ECM IS ALSO FAVORING THIS GENERAL POSITIONING OF THE LOW. AS FAR AS SVR POTENTIAL IS CONCERNED...WIDESPREAD CLOUDINESS AND RAIN SHOWER ACTIVITY WILL ACT TO LIMIT DESTABILIZATION DURING THE DAY SAT...AND NOT EXPECTING MUCH IN WAY OF ORGANIZED CONVECTION. NEVERTHELESS...BULK SHEAR WILL BE SUFFICIENT FOR A FEW STORMS TO BECOME STRONG TO SEVERE WITH MAIN THREAT ISOLATED DAMAGING WINDS. GFS AND NAM INDICATE SFC WINDS BECOME BACKED SSE SAT EVENING AS H85-H90 FLOW REMAINS SW. THIS WOULD PRODUCE FAIR AMOUNT OF LOW LEVEL TURNING/0-3KM HELICITY. SHOULD ANY STORMS BECOME MORE ORGANIZED...CANNOT RULE OUT AN ISOLATED TORNADO THREAT ESP LATE SAT AFTERNOON THROUGH EARLY EVENING BEFORE LOW PULLS EAST AND SFC WINDS VEER SW TO W. RAIN SHOWERS WILL DECREASE SAT NIGHT AS MOISTURE AND LIFT SHIFT EAST WITH SFC EXITING SFC LOW. TEMPS WILL BE MILD MOST OF THE NIGHT BEFORE WINDS BECOME W TO EVENTUALLY NW BY LATE SAT NIGHT AND ALLOW TEMPS TO COOL TO THE LOW 50S. UPR LEVEL VORT WILL SLOWLY MIGRATE EAST THROUGH THE DAY SUNDAY...AND HAVE CONTINUED TO WEIGHT ECMWF SOLN WHICH WOULD KEEP WIDESPREAD LOW CLOUDS AND NUMEROUS SHOWERS ACROSS E NC THROUGH THE FIRST HALF OF SUNDAY. HAVE INC POPS TO LIKELY ACROSS THE NE ZONES...AND RETAINED HIGH CHANCE SCT WORDING FURTHER S AND W. TEMPS WILL ALSO BE ON THE COOL SIDE WITH THE WIDESPREAD CLOUDS AND SHOWER ACTIVITY WITH MOST AREAS IN THE MID 50S...WITH SOME LOW 50S OBX. DRAMATIC CLEARING OCCURS SUN NIGHT AS UPR LOW MOVES OUT TO SEA AND TEMPS SEASONABLY COOL IN THE UPR 30S/LOW 40S FOR LOWS MON MORNING. VERY DRY AIRMASS FOR MONDAY AS STRONG SUBSIDENCE AND BUILDING HIGH PRES MOVE INTO THE AREA. 1000-850MB RH VALS PLUMMET TO THE 20% RANGE ACCORDING TO THE ECM. WILL HAVE TO MONITOR FOR POTENTIAL FIRE WEATHER CONCERNS. TEMPS WILL REBOUND TO THE MID/UPR 60S. SPRAWLING SFC HIGH PRES WITH QUASI ZONAL FLOW WILL PRODUCE PLEASANTLY DRY AND WARM CONDITIONS THROUGH THE MID WEEK TIME PERIOD AND BEYOND WITH TEMPS WARMING TO THE MID/UPR 70S TO NEAR 80 BY THURSDAY. NEXT SYSTEM MAY AFFECT THE REGION FRIDAY INTO THE WEEKEND. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 18Z SATURDAY/... AS OF 115 PM FRIDAY...VFR CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON WITH SUB-VFR FORECASTED THIS EVENING THROUGH TOMORROW. A POTENT LOW PRESSURE SYSTEM WILL BE APPROACHING THE REGION FROM THE WEST. THEREFORE...EXPECT CLOUDS TO INCREASE/LOW THROUGH THE LATE AFTERNOON/EVENING HOURS. GUSTY SOUTHERLY FLOW WILL CONTINUE FOR THE NEXT COUPLE OF HOURS BUT SUBSIDE AS THE SURFACE HEATING DIMINISHES. RAIN SHOULD ARRIVE THIS EVENING THROUGH THE OVERNIGHT HOURS WITH VSBYS LOWERING IN RESPONSE. ANTICIPATE MAINLY MVFR AND SOME PATCHY IFR CIGS/VSBYS THROUGH THE OVERNIGHT HOURS INTO SATURDAY MORNING. SSE WINDS AROUND 5-10KTS EXPECTED SATURDAY. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 4 AM FRI...MVFR OR LOWER IN NUMEROUS SHOWERS AND EMBEDDED THUNDER SAT THROUGH SAT NIGHT. THE FRONT WILL MOVE OFF THE COAST EARLY SUNDAY WITH SURFACE WINDS VEERING FROM SOUTH SOUTHWEST TO NORTHWEST. SUB-VFR CONTINUES SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS IN LINGERING WRAPAROUND MOISTURE. VFR RETURNS ON SUN NIGHT THROUGH MUCH OF NEXT WEEK AS LARGE HIGH PRES BUILDS IN BRINGING EXCELLENT FLYING CONDITIONS. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1 PM FRIDAY...SOUTHERLY WINDS ARE GRADUALLY INCREASING TO 15 TO 20 KNOTS ACROSS MOST OF THE WATERS AND SEAS ARE BUILDING WITH 6 FOOT NOW REPORTED AT DIAMOND BUOY. OTHER THAN BUMPING UP THE INITIAL WINDS...NO BIG CHANGES TO THE MARINE FORECAST AT THIS TIME. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 4 AM FRI...POOR BOATING CONDITIONS SAT THROUGH THE FIRST PART OF NEXT WEEK. SW WINDS WILL INC ONCE AGAIN DURING THE DAY SAT TO 25 KT OR HIGHER...ESP THE SOUTHERN/CENTRAL WATERS...AND SEAS WILL INC TO 6 FT OR HIGHER. THE S TO SW WINDS WILL REMAIN STRONG THROUGH SAT EVENING AHEAD OF LOW PRES AND A COLD FRONT. THE LOW WILL MOVE OFFSHORE WITH THE COLD FRONT LATE SAT NIGHT AND WINDS TURNING TO THE W AND THEN NW BY SUN MORNING. THE OFFSHORE LOW WILL SLOWLY PUSH AWAY AND KEEP THE NW GRADIENT RATHER STRONG WITH SCA CONTINUING THROUGH THE DAY SUNDAY. WINDS WILL FINALLY DIMINISH ON MONDAY THOUGH LINGERING LARGE SWELL ABOVE 6 FT WILL CONTINUE ESP ACROSS NORTHERN/CENTRAL WATERS. CONDITIONS IMPROVE MON NIGHT AS GRADIENT RELAXES. WINDS WILL TURN SW BUT REMAIN LIGHT TUE THROUGH MID WEEK AS LARGE HIGH PRES MOVES TO THE SOUTH OF THE AREA. PLEASANT BOATING CONDITIONS EXPECTED DURING THIS TIME FRAME. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ152-154- 156-158. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...TL AVIATION...TL/LEP MARINE...JBM/CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 PM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATER THIS AFTERNOON AND THEN STALL TO THE NORTH TONIGHT. DEVELOPING LOW PRESSURE MOVING ACROSS TO THE NORTH WILL PULL THE FRONT THROUGH THE AREA SATURDAY NIGHT. THE LOW WILL CONTINUE DEEPENING AS IT MOVES TO THE NORTHEAST SUNDAY AND SUNDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE WEST THROUGH MONDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1 PM FRIDAY...HAVE AGAIN RAISED MAXIMUM TEMPERATURES A COUPLE OF DEGREES AS MANY PLACES HAVE SOARED INTO THE LOWER 70S AND MID 70S ARE NOT OUT OF THE QUESTION OVER THE NEXT COUPLE OF HOURS. REMAINDER OF FORECAST REMAINS ON TRACK WITH SHOWERS MOVING INTO THE FAR WESTERN COUNTIES AROUND 21Z OR SO BASED ON 4 KM NSSL WRF AND RAP MODELS. INSTABILITY LACKING AND DO NOT EXPECT ANY THUNDER UNTIL SATURDAY AT THIS TIME. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... AS OF 430 AM FRIDAY...INCREASING MSTR AND SHRT WV ACTIVITY WILL PRODUCE HIGHER THREAT OF SHOWERS TONIGHT...WITH TSTM MENTION LIMITED TO COAST. GENERALLY CONTINUED PREVIOUS FCST OF POPS 50% COAST TO 70% INLAND THIS EVENING...AND 60%-70% ALL ZONES OVERNIGHT. SRLY FLOW AND CLOUD COVER WILL KEEP TEMPS MID 50S TO AROUND 60. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 4 AM FRI...UNSETTLED PATTERN TO START THE LONG TERM PERIOD THIS WEEKEND...THEN DRY AND SEASONABLY WARM FOR NEXT WEEK. SHORT WAVE TROUGH ACROSS CENTRAL CONUS TODAY WILL AMPLIFY THROUGH SATURDAY AND CLOSE OFF A MID LEVEL VORT SAT EVENING. MODELS COMING IN BETTER AGREEMENT ON THIS SYNOPTIC SETUP AS WELL AS TIMING OF THE FEATURES. THE NEUTRAL TILT CLOSED LOW WILL PROMOTE SFC LOW DEVELOPMENT OVER CENTRAL NC SAT EVENING. AHEAD OF IT...INC SW LLJ WILL FURTHER INC MOISTURE ADVECTION INTO E NC. BNDRY LAYER STREAMLINES SUGGEST MOISTURE CONVERGENCE WILL BE MAXIMIZED SAT EVENING...WITH BEST CHANCE OF WIDESPREAD RAIN SHOWERS OCCURRING THEN. AHEAD OF THE SYSTEM...OCNL SHOWERS WITH EMBEDDED THUNDER WILL OCCUR DURING THE DAY SAT. GFS ENSEMBLES CLUSTER FAIRLY WELL WITH SFC LOW PLACEMENT ACROSS NC TO SOUTHERN VA BETWEEN 00Z AND 06Z SUN. THE 28/00Z ECM IS ALSO FAVORING THIS GENERAL POSITIONING OF THE LOW. AS FAR AS SVR POTENTIAL IS CONCERNED...WIDESPREAD CLOUDINESS AND RAIN SHOWER ACTIVITY WILL ACT TO LIMIT DESTABILIZATION DURING THE DAY SAT...AND NOT EXPECTING MUCH IN WAY OF ORGANIZED CONVECTION. NEVERTHELESS...BULK SHEAR WILL BE SUFFICIENT FOR A FEW STORMS TO BECOME STRONG TO SEVERE WITH MAIN THREAT ISOLATED DAMAGING WINDS. GFS AND NAM INDICATE SFC WINDS BECOME BACKED SSE SAT EVENING AS H85-H90 FLOW REMAINS SW. THIS WOULD PRODUCE FAIR AMOUNT OF LOW LEVEL TURNING/0-3KM HELICITY. SHOULD ANY STORMS BECOME MORE ORGANIZED...CANNOT RULE OUT AN ISOLATED TORNADO THREAT ESP LATE SAT AFTERNOON THROUGH EARLY EVENING BEFORE LOW PULLS EAST AND SFC WINDS VEER SW TO W. RAIN SHOWERS WILL DECREASE SAT NIGHT AS MOISTURE AND LIFT SHIFT EAST WITH SFC EXITING SFC LOW. TEMPS WILL BE MILD MOST OF THE NIGHT BEFORE WINDS BECOME W TO EVENTUALLY NW BY LATE SAT NIGHT AND ALLOW TEMPS TO COOL TO THE LOW 50S. UPR LEVEL VORT WILL SLOWLY MIGRATE EAST THROUGH THE DAY SUNDAY...AND HAVE CONTINUED TO WEIGHT ECMWF SOLN WHICH WOULD KEEP WIDESPREAD LOW CLOUDS AND NUMEROUS SHOWERS ACROSS E NC THROUGH THE FIRST HALF OF SUNDAY. HAVE INC POPS TO LIKELY ACROSS THE NE ZONES...AND RETAINED HIGH CHANCE SCT WORDING FURTHER S AND W. TEMPS WILL ALSO BE ON THE COOL SIDE WITH THE WIDESPREAD CLOUDS AND SHOWER ACTIVITY WITH MOST AREAS IN THE MID 50S...WITH SOME LOW 50S OBX. DRAMATIC CLEARING OCCURS SUN NIGHT AS UPR LOW MOVES OUT TO SEA AND TEMPS SEASONABLY COOL IN THE UPR 30S/LOW 40S FOR LOWS MON MORNING. VERY DRY AIRMASS FOR MONDAY AS STRONG SUBSIDENCE AND BUILDING HIGH PRES MOVE INTO THE AREA. 1000-850MB RH VALS PLUMMET TO THE 20% RANGE ACCORDING TO THE ECM. WILL HAVE TO MONITOR FOR POTENTIAL FIRE WEATHER CONCERNS. TEMPS WILL REBOUND TO THE MID/UPR 60S. SPRAWLING SFC HIGH PRES WITH QUASI ZONAL FLOW WILL PRODUCE PLEASANTLY DRY AND WARM CONDITIONS THROUGH THE MID WEEK TIME PERIOD AND BEYOND WITH TEMPS WARMING TO THE MID/UPR 70S TO NEAR 80 BY THURSDAY. NEXT SYSTEM MAY AFFECT THE REGION FRIDAY INTO THE WEEKEND. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 12Z SATURDAY/... AS OF 730 AM FRIDAY...VFR CONDITIONS WILL PREVAIL INTO THIS AFTN...THEN MVFR CIGS/VSBYS EXPECTED WITH SHRA DURING EVENING LINGERING INTO OVERNIGHT. PRE-FRONTAL WARM SECTOR CONDITIONS EXPECTED DURING THE TAF PERIOD WITH HIGH PRES OFFSHORE AND COLD FRONT APPROACHING FROM W. SCT-BKN SCU WILL DEVELOP THROUGH MORNING HOURS WITH INCREASING SRLY FLOW BUT CIGS EXPECTED TO REMAIN ABOVE 3K FT. ISOLD SHRA PSBL INLAND LATE MORNING BUT BETTER COVERAGE LIKELY DURING AFTN AND EVENING WITH CIGS AND VSBYS LOWERING TO MVFR. MOIST LOW LVLS WILL RESULT IN CIGS LOWERING TO AROUND 1K FT FOR INLAND SITES OVERNIGHT. SRLY WINDS WILL GUST UP TO 20-25 KT THIS AFTN. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 4 AM FRI...MVFR OR LOWER IN NUMEROUS SHOWERS AND EMBEDDED THUNDER SAT THROUGH SAT NIGHT. THE FRONT WILL MOVE OFF THE COAST EARLY SUNDAY WITH SURFACE WINDS VEERING FROM SOUTH SOUTHWEST TO NORTHWEST. SUB-VFR CONTINUES SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS IN LINGERING WRAPAROUND MOISTURE. VFR RETURNS ON SUN NIGHT THROUGH MUCH OF NEXT WEEK AS LARGE HIGH PRES BUILDS IN BRINGING EXCELLENT FLYING CONDITIONS. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1 PM FRIDAY...SOUTHERLY WINDS ARE GRADUALLY INCREASING TO 15 TO 20 KNOTS ACROSS MOST OF THE WATERS AND SEAS ARE BUILDING WITH 6 FOOT NOW REPORTED AT DIAMOND BUOY. OTHER THAN BUMPING UP THE INITIAL WINDS...NO BIG CHANGES TO THE MARINE FORECAST AT THIS TIME. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 4 AM FRI...POOR BOATING CONDITIONS SAT THROUGH THE FIRST PART OF NEXT WEEK. SW WINDS WILL INC ONCE AGAIN DURING THE DAY SAT TO 25 KT OR HIGHER...ESP THE SOUTHERN/CENTRAL WATERS...AND SEAS WILL INC TO 6 FT OR HIGHER. THE S TO SW WINDS WILL REMAIN STRONG THROUGH SAT EVENING AHEAD OF LOW PRES AND A COLD FRONT. THE LOW WILL MOVE OFFSHORE WITH THE COLD FRONT LATE SAT NIGHT AND WINDS TURNING TO THE W AND THEN NW BY SUN MORNING. THE OFFSHORE LOW WILL SLOWLY PUSH AWAY AND KEEP THE NW GRADIENT RATHER STRONG WITH SCA CONTINUING THROUGH THE DAY SUNDAY. WINDS WILL FINALLY DIMINISH ON MONDAY THOUGH LINGERING LARGE SWELL ABOVE 6 FT WILL CONTINUE ESP ACROSS NORTHERN/CENTRAL WATERS. CONDITIONS IMPROVE MON NIGHT AS GRADIENT RELAXES. WINDS WILL TURN SW BUT REMAIN LIGHT TUE THROUGH MID WEEK AS LARGE HIGH PRES MOVES TO THE SOUTH OF THE AREA. PLEASANT BOATING CONDITIONS EXPECTED DURING THIS TIME FRAME. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ152-154- 156-158. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...TL AVIATION...JBM/TL MARINE...JBM/CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1258 PM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY. TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM FRIDAY...LIGHT SHOWERS HAVE DEVELOPED ALONG THE GENERAL CORRIDOR INDICATED BY THE HRRR MODEL RUNS EARLIER THIS MORNING...FROM GEORGETOWN THROUGH CONWAY...MARION AND DILLON. THIS APPEARS TO BE THE PREFERRED AXIS FOR ADDITIONAL SHOWER DEVELOPMENT THROUGH THE AFTERNOON...WITH LITTLE INDICATION SHOWER POTENTIAL WILL RISE ACROSS THE WILMINGTON METRO AREA UNTIL PERHAPS NEAR SUNSET. A LARGE AREA OF RAIN WITH EMBEDDED SHOWERY/CONVECTIVE ELEMENTS JUST NOW CROSSING THE SAVANNAH RIVER INTO CENTRAL AND WESTERN SOUTH CAROLINA WILL BEGIN TO IMPINGE ON OUR PEE DEE COUNTIES (FLORENCE AND DARLINGTON) LATE THIS AFTERNOON...WITH SHOWER CHANCES INCREASING RAPIDLY INTO THE EARLY EVENING HOURS. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... HIGH PRESSURE IS WELL OFFSHORE AND SOUTH WINDS ACROSS THE CAROLINAS ARE BEING CAUSED BY RETURN FLOW BETWEEN THE HIGH AND A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS. SUBTROPICAL MOISTURE MOVING NORTHWARD IS SHOWING UP WITH CLIMBING SURFACE DEWPOINTS AND PRECIPITABLE WATER VALUES...BOTH EXPECTED TO RISE SIGNIFICANTLY TONIGHT. AN AREA OF THICK MID AND HIGH CLOUDINESS ACROSS THE SOUTHEASTERN STATES IS BEING PRODUCED BY A MESOSCALE CONVECTIVE SYSTEM ACROSS MISSISSIPPI. SYNOPTIC MODELS ARE HAVING THEIR TROUBLE WITH THIS SYSTEM...BUT THE LATEST FEW RUNS OF THE HRRR SHOW THE BULK OF THIS CONVECTION DIMINISHING BEFORE ADVECTING THIS FAR EAST. INCREASING MOISTURE SHOULD YIELD AN INCREASE IN SHOWER ACTIVITY LATE THIS AFTERNOON ACROSS THE PEE DEE REGION...REACHING THE COAST AROUND SUNSET OR SHORTLY THEREAFTER. A SECOND UNRELATED AREA OF SHOWERS DEVELOPING ALONG THE GULF STREAM OFF THE GA/SC COAST IS STREAMING NORTHWARD NEAR CHARLESTON AND GEORGETOWN...AND THREATENS TO BRING SHOWERS ACROSS EASTERN SOUTH CAROLINA OVER THE NEXT SEVERAL HOURS. POP/WX FORECASTS HAVE BEEN UPDATED TO FOCUS ON THESE TWO AREAS. FEW CHANGES HAVE BEEN MADE TO FORECAST TEMPERATURES...STILL EXPECTED TO REACH THE LOWER 70S FOR MOST AREAS AWAY FROM THE COOLING INFLUENCE OF THE OCEAN. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SURFACE LOW AND MID LEVEL TROUGH WILL BE WEST OF THE AREA AT THE START OF THE PERIOD WITH THE REGION SOLIDLY IN THE WARM SECTOR. SEVERAL FACTORS APPEAR TO BE IN PLACE SUPPORTING CONVECTION SAT INTO SAT NIGHT. STRENGTHENING MID LEVEL SOUTHWEST FLOW WILL CONTINUE TO PUMP MOISTURE INTO THE REGION. FORECAST SOUNDINGS SHOW PRECIPITABLE WATER VALUES CLOSE TO 1.5 INCH. DIURNAL INSTABILITY WILL ALSO BE PRESENT WITH HIGHS EXPECTED TO CLIMB INTO THE LOWER 70S IN MOST AREAS. LOW LEVEL CONVERGENCE ALONG THE RESULTANT SEA BREEZE MAY INITIATE CONVECTION IN THE AFTERNOON. ALOFT THE APPROACHING 5H TROUGH WILL ENHANCE MID LEVEL LAPSE RATES BUT THE UNKNOWN FACTOR AT THIS POINT REMAINS WHAT IMPACT POTENTIAL CONVECTION IN THE NORTHEAST GULF OF MEXICO WILL HAVE ON INSTABILITY SHOWERS/THUNDERSTORMS. FARTHER WEST A LINE OF CONVECTION SHOULD BE DEVELOPING ASSOCIATED WITH THE ADVANCING COLD FRONT. THIS LINE WILL MOVE INTO WHAT SHOULD BE A MOIST/UNSTABLE ENVIRONMENT LATE SAT AND PUSH OFF THE COAST SAT NIGHT. ALTHOUGH THE FRONT WILL HAVE PLENTY OF LOW LEVEL CONVERGENCE AND MID LEVEL SUPPORT THERE IS SOME QUESTION AS TO THE STATE OF THE ATMOSPHERE IT WILL BE MOVING INTO. THE CONVECTIVE LINE ASSOCIATED WITH THE FRONT MAY END UP WEAKENING AS IT MOVES INTO THE REGION IF EARLIER AFTERNOON CONVECTION IS MORE WIDESPREAD AND USES UP A LOT OF THE AVAILABLE INSTABILITY. ON THE OTHER HAND SHOULD THE GULF CONVECTION BE ABLE TO SUPPRESS MUCH OF THE ACTIVITY DURING THE FIRST HALF OF SAT THE COLD FRONT WOULD HAVE PLENTY OF INSTABILITY TO WORK WITH. SO IT IS NOT SO MUCH A QUESTION OF WILL IT RAIN...BUT MORE OF A QUESTION OF WHEN WILL IT RAIN. SEVERE WEATHER THREAT PERSISTS...ALTHOUGH WITH CAVEATS. LOW LEVEL JETTING WILL BE WEAK FOR MUCH OF THE DAY BEFORE INCREASING TO 30 TO 35 KT JUST AHEAD OF THE FRONT. THE MAIN THREAT WOULD BE DAMAGING WIND...ENHANCED BY STORMS MOVING CLOSE TO 30 MPH. IF STRONG/SEVERE STORMS DEVELOP THEY ARE LIKELY TO DO SO WITH THE LINE OF CONVECTION AHEAD OF THE FRONT...AGAIN ASSUMING DIURNAL DRIVEN CONVECTION IS LIMITED IN SCOPE DURING THE DAY SAT. COLD FRONT PUSHES OFF THE COAST LATE SAT NIGHT WITH THE MID LEVEL TROUGH FOLLOWING ON SUN. COLD ADVECTION BEHIND THE FRONT WILL DROP SUN TEMPS BELOW CLIMO...BUT COLD AIR WILL BE A LITTLE TOO LATE TO HAVE A SIGNIFICANT IMPACT ON SAT NIGHT LOWS WHICH WILL END UP NEAR TO SLIGHTLY ABOVE CLIMO. SUN SHOULD BE DRY WITH DEEP NORTHWEST FLOW BEHIND THE TROUGH DROPPING PWATS UNDER .5 INCH FOR SUN AM AND UNDER .25 INCH BY SUN EVENING. GRADIENT RELAXES SUN NIGHT BUT HIGH REMAINS WEST OF THE AREA THROUGH THE END OF THE PERIOD SO SUN NIGHT WILL NOT BE AN IDEAL RADIATIONAL COOLING NIGHT. STILL LOWS END UP BELOW CLIMO. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LOW AMPLITUDE MID LEVEL RIDGING AND SPRAWLING SURFACE HIGH WILL KEEP THE AREA DRY AND SEASONABLE THROUGH THE PERIOD. COOLEST DAY WILL BE MON WITH SURFACE HIGH DIRECTLY OVERHEAD. HIGH THEN DRIFTS OFFSHORE TUE THROUGH THU BRINGING SEVERAL DAYS OF BEAUTIFUL SPRING WEATHER. PREVIOUSLY MEDIUM RANGE GUIDANCE HAD BEEN MOVING A DRY COLD FRONT ACROSS THE AREA TUE NIGHT INTO WED. NOW THAT GUIDANCE IS SUGGESTING MORE MID LEVEL AMPLIFICATION THIS SEEMS UNLIKELY AND IN FACT THE 00Z GUIDANCE IS BACKING OFF ON THE DRY FRONT. TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO MON TRANSITION TO ABOVE CLIMO MON NIGHT THROUGH THE END OF THE PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 18Z...QUITE A BIT OF UNCERTAINTY WITH RESPECT TO THE TIMING OF THE PRECIP...AS WELL AS CEILINGS OVERNIGHT. SOUTHERLY GRADIENT WILL CAUSE WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE COAST. SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD LIGHT TO MODERATE RAIN THIS EVENING AS DEEP MOISTURE MOVES INTO THE REGION. RAIN CHANCES WILL BE HIGHEST INLAND THIS EVENING...SPREADING TO THE COAST A FEW HOURS LATER. CEILINGS ARE A BIT PROBLEMATIC...BUT WILL GO FOR MVFR PREDOMINATELY WITH POCKETS OF IFR POSSIBLE. TIME HEIGHT INDICATES THERE MAY BE A LULL IN THE PRECIP OF ABOUT 6-7 HOURS THROUGH THE LATE OVERNIGHT HOURS. SATURDAY...MODERATE TO PERHAPS HEAVY PRECIP SPREADING FROM WEST TO EAST. AN EMBEDDED THUNDERSTORM CANNOT BE RULED OUT. IN FACT...IF WE GET SOME CAPE WE COULD HAVE A FEW STRONGER STORMS IN THE AFTERNOON INTO EARLY EVENING. AGAIN CEILINGS PREDOMINATELY MVFR. EXTENDED OUTLOOK...BECOMING VFR SATURDAY NIGHT. SLIGHT CHANCE FOR SHOWERS AND MVFR CEILINGS OVER THE NORTHERN PORTION OF THE CWA. OTHERWISE VFR THROUGH WEDNESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM FRIDAY...NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE FORECAST WITH THIS EARLY AFTERNOON UPDATE. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... HIGH PRESSURE THAT MOVED OFF THE NC COAST YESTERDAY IS NOW CROSSING 60 DEGREES WEST LONGITUDE AS IT CONTINUES TO PUT DISTANCE BETWEEN ITSELF AND THE EAST COAST. LOW PRESSURE MOVING THROUGH THE GREAT LAKES HAS A COLD FRONT EXTENDING SOUTH INTO TEXAS. THIS FRONT WILL NOT ARRIVE UNTIL TOMORROW...ALLOWING SOUTHERLY WINDS AHEAD OF THE FRONT TO CONTINUE ADVECTING A SUBTROPICAL AIRMASS ACROSS THE COASTAL WATERS. AS DEWPOINTS INCREASE AND EXCEED THE NEARSHORE WATER TEMPERATURES THERE IS AN INCREASING POTENTIAL FOR SEA FOG THIS AFTERNOON AND TONIGHT...PARTICULARLY WITHIN 10 MILES OF SHORE WHERE WATER TEMPERATURES ARE COLDEST. SOUTH WINDS CURRENTLY AROUND 10-12 KNOTS SHOULD INCREASE A FEW MORE KNOTS TODAY...BUT MAY ACTUALLY DIMINISH A LITTLE THIS EVENING AS AN AREA OF DYING CONVECTION ARRIVES AND THE PRESSURE GRADIENT IS DISRUPTED. REGARDLESS...WINDS SHOULD BUILD BACK UP TOWARD 12-15 KNOTS OVERNIGHT. SEAS ARE STILL A BIT HIGHER THAN WIND SPEEDS ALONE WOULD SUGGEST...COURTESY OF THE HUGE LOW THAT MOVED NORTH THROUGH THE WESTERN ATLANTIC A FEW DAYS AGO. AT THE FRYING PAN SHOALS BUOY THERE IS STILL A SMALL 14 SECOND EAST SWELL PRESENT...WHICH WHEN ADDED TO THE SHORTER 6-SECOND PERIOD WIND WAVES TOTALS AROUND 4 FEET. TOTAL SEAS EVEN INSIDE 20 MILES SHOULD INCREASE ON TOWARD 4-6 FEET BY THIS EVENING. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW WILL APPROACH 20 KT SAT AS GRADIENT OVER THE WATERS IS PINCHED BETWEEN ADVANCING COLD FRONT AND HIGH PRESSURE. ANTICIPATE A LINE OF CONVECTION AHEAD OF THE FRONT WHICH WILL CROSS THE WATERS SAT EVE/NIGHT. OFFSHORE FLOW DEVELOPS BEHIND THE FRONT WITH GRADIENT AND DEVELOPING COLD ADVECTION KEEPING SPEEDS AROUND 20 KT. LITTLE CHANGE IN THE GRADIENT SUN AS HIGH BUILDS KEEPS NORTHWEST WINDS A SOLID 20 KT FOR MUCH OF THE DAY. OFFSHORE FLOW SLOWLY WEAKENS SUN NIGHT...DROPPING TO 15 KT BY THE END OF THE PERIOD...AS GRADIENT RELAXES. SEAS 4 TO 6 FT EXPECTED SAT INTO SUN WHEN OFFSHORE COMPONENT DROPS SEAS TO 3 TO 5 FT. CONTINUED OFFSHORE FLOW COMBINED WITH REDUCTION IN SPEEDS SUN NIGHT WILL DROP SEAS TO 2 TO 4 FT BY THE END OF THE PERIOD. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...OFFSHORE FLOW AROUND 15 KT AT THE START OF THE PERIOD WILL DECREASE DURING MON AS HIGH PRESSURE MOVES OVER HEAD. SPEEDS WILL DROP UNDER 10 KT BY MON EVENING...BECOMING LIGHT AND VARIABLE MON NIGHT. HIGH SHIFTS OFFSHORE FOR TUE WITH RETURN FLOW SLOWLY RISING INTO THE 10 TO 15 KT RANGE LATE TUE AND TUE NIGHT. SEAS WILL RUN 2 TO 3 FT FOR A MAJORITY OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT SATURDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1058 AM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY. TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...HIGH PRESSURE IS WELL OFFSHORE AND SOUTH WINDS ACROSS THE CAROLINAS ARE BEING CAUSED BY RETURN FLOW BETWEEN THE HIGH AND A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS. SUBTROPICAL MOISTURE MOVING NORTHWARD IS SHOWING UP WITH CLIMBING SURFACE DEWPOINTS AND PRECIPITABLE WATER VALUES...BOTH EXPECTED TO RISE SIGNIFICANTLY TONIGHT. AN AREA OF THICK MID AND HIGH CLOUDINESS ACROSS THE SOUTHEASTERN STATES IS BEING PRODUCED BY A MESOSCALE CONVECTIVE SYSTEM ACROSS MISSISSIPPI. SYNOPTIC MODELS ARE HAVING THEIR TROUBLE WITH THIS SYSTEM...BUT THE LATEST FEW RUNS OF THE HRRR SHOW THE BULK OF THIS CONVECTION DIMINISHING BEFORE ADVECTING THIS FAR EAST. INCREASING MOISTURE SHOULD YIELD AN INCREASE IN SHOWER ACTIVITY LATE THIS AFTERNOON ACROSS THE PEE DEE REGION...REACHING THE COAST AROUND SUNSET OR SHORTLY THEREAFTER. A SECOND UNRELATED AREA OF SHOWERS DEVELOPING ALONG THE GULF STREAM OFF THE GA/SC COAST IS STREAMING NORTHWARD NEAR CHARLESTON AND GEORGETOWN...AND THREATENS TO BRING SHOWERS ACROSS EASTERN SOUTH CAROLINA OVER THE NEXT SEVERAL HOURS. POP/WX FORECASTS HAVE BEEN UPDATED TO FOCUS ON THESE TWO AREAS. FEW CHANGES HAVE BEEN MADE TO FORECAST TEMPERATURES...STILL EXPECTED TO REACH THE LOWER 70S FOR MOST AREAS AWAY FROM THE COOLING INFLUENCE OF THE OCEAN. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SURFACE LOW AND MID LEVEL TROUGH WILL BE WEST OF THE AREA AT THE START OF THE PERIOD WITH THE REGION SOLIDLY IN THE WARM SECTOR. SEVERAL FACTORS APPEAR TO BE IN PLACE SUPPORTING CONVECTION SAT INTO SAT NIGHT. STRENGTHENING MID LEVEL SOUTHWEST FLOW WILL CONTINUE TO PUMP MOISTURE INTO THE REGION. FORECAST SOUNDINGS SHOW PRECIPITABLE WATER VALUES CLOSE TO 1.5 INCH. DIURNAL INSTABILITY WILL ALSO BE PRESENT WITH HIGHS EXPECTED TO CLIMB INTO THE LOWER 70S IN MOST AREAS. LOW LEVEL CONVERGENCE ALONG THE RESULTANT SEA BREEZE MAY INITIATE CONVECTION IN THE AFTERNOON. ALOFT THE APPROACHING 5H TROUGH WILL ENHANCE MID LEVEL LAPSE RATES BUT THE UNKNOWN FACTOR AT THIS POINT REMAINS WHAT IMPACT POTENTIAL CONVECTION IN THE NORTHEAST GULF OF MEXICO WILL HAVE ON INSTABILITY SHOWERS/THUNDERSTORMS. FARTHER WEST A LINE OF CONVECTION SHOULD BE DEVELOPING ASSOCIATED WITH THE ADVANCING COLD FRONT. THIS LINE WILL MOVE INTO WHAT SHOULD BE A MOIST/UNSTABLE ENVIRONMENT LATE SAT AND PUSH OFF THE COAST SAT NIGHT. ALTHOUGH THE FRONT WILL HAVE PLENTY OF LOW LEVEL CONVERGENCE AND MID LEVEL SUPPORT THERE IS SOME QUESTION AS TO THE STATE OF THE ATMOSPHERE IT WILL BE MOVING INTO. THE CONVECTIVE LINE ASSOCIATED WITH THE FRONT MAY END UP WEAKENING AS IT MOVES INTO THE REGION IF EARLIER AFTERNOON CONVECTION IS MORE WIDESPREAD AND USES UP A LOT OF THE AVAILABLE INSTABILITY. ON THE OTHER HAND SHOULD THE GULF CONVECTION BE ABLE TO SUPPRESS MUCH OF THE ACTIVITY DURING THE FIRST HALF OF SAT THE COLD FRONT WOULD HAVE PLENTY OF INSTABILITY TO WORK WITH. SO IT IS NOT SO MUCH A QUESTION OF WILL IT RAIN...BUT MORE OF A QUESTION OF WHEN WILL IT RAIN. SEVERE WEATHER THREAT PERSISTS...ALTHOUGH WITH CAVEATS. LOW LEVEL JETTING WILL BE WEAK FOR MUCH OF THE DAY BEFORE INCREASING TO 30 TO 35 KT JUST AHEAD OF THE FRONT. THE MAIN THREAT WOULD BE DAMAGING WIND...ENHANCED BY STORMS MOVING CLOSE TO 30 MPH. IF STRONG/SEVERE STORMS DEVELOP THEY ARE LIKELY TO DO SO WITH THE LINE OF CONVECTION AHEAD OF THE FRONT...AGAIN ASSUMING DIURNAL DRIVEN CONVECTION IS LIMITED IN SCOPE DURING THE DAY SAT. COLD FRONT PUSHES OFF THE COAST LATE SAT NIGHT WITH THE MID LEVEL TROUGH FOLLOWING ON SUN. COLD ADVECTION BEHIND THE FRONT WILL DROP SUN TEMPS BELOW CLIMO...BUT COLD AIR WILL BE A LITTLE TOO LATE TO HAVE A SIGNIFICANT IMPACT ON SAT NIGHT LOWS WHICH WILL END UP NEAR TO SLIGHTLY ABOVE CLIMO. SUN SHOULD BE DRY WITH DEEP NORTHWEST FLOW BEHIND THE TROUGH DROPPING PWATS UNDER .5 INCH FOR SUN AM AND UNDER .25 INCH BY SUN EVENING. GRADIENT RELAXES SUN NIGHT BUT HIGH REMAINS WEST OF THE AREA THROUGH THE END OF THE PERIOD SO SUN NIGHT WILL NOT BE AN IDEAL RADIATIONAL COOLING NIGHT. STILL LOWS END UP BELOW CLIMO. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LOW AMPLITUDE MID LEVEL RIDGING AND SPRAWLING SURFACE HIGH WILL KEEP THE AREA DRY AND SEASONABLE THROUGH THE PERIOD. COOLEST DAY WILL BE MON WITH SURFACE HIGH DIRECTLY OVERHEAD. HIGH THEN DRIFTS OFFSHORE TUE THROUGH THU BRINGING SEVERAL DAYS OF BEAUTIFUL SPRING WEATHER. PREVIOUSLY MEDIUM RANGE GUIDANCE HAD BEEN MOVING A DRY COLD FRONT ACROSS THE AREA TUE NIGHT INTO WED. NOW THAT GUIDANCE IS SUGGESTING MORE MID LEVEL AMPLIFICATION THIS SEEMS UNLIKELY AND IN FACT THE 00Z GUIDANCE IS BACKING OFF ON THE DRY FRONT. TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO MON TRANSITION TO ABOVE CLIMO MON NIGHT THROUGH THE END OF THE PERIOD. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...RETURN FLOW WILL COMMENCE SHORTLY. HAVE LEANED FAIRLY HEAVILY ON THE HRRR EARLY...WITH SHOWERS POPPING UP ALONG THE MYRTLES BY LATE MORNING. INCREASING SOUTHERLY GRADIENT WILL CAUSE WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE COAST. SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD RAIN THIS EVENING AS DEEP MOISTURE MOVES INTO THE REGION. RAIN CHANCES WILL BE HIGHEST INLAND THIS EVENING...SPREADING TO THE COAST A FEW HOURS LATER. CEILINGS ARE A BIT PROBLEMATIC...BUT WILL GO FOR MVFR PREDOMINATELY WITH POCKETS OF IFR POSSIBLE. EXTENDED OUTLOOK...SHOWERS AND T-STORMS WITH MVFR/TEMPO IFR CONDITIONS OVERNIGHT AND ON SATURDAY. VFR SUNDAY THROUGH TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...HIGH PRESSURE THAT MOVED OFF THE NC COAST YESTERDAY IS NOW CROSSING 60 DEGREES WEST LONGITUDE AS IT CONTINUES TO PUT DISTANCE BETWEEN ITSELF AND THE EAST COAST. LOW PRESSURE MOVING THROUGH THE GREAT LAKES HAS A COLD FRONT EXTENDING SOUTH INTO TEXAS. THIS FRONT WILL NOT ARRIVE UNTIL TOMORROW...ALLOWING SOUTHERLY WINDS AHEAD OF THE FRONT TO CONTINUE ADVECTING A SUBTROPICAL AIRMASS ACROSS THE COASTAL WATERS. AS DEWPOINTS INCREASE AND EXCEED THE NEARSHORE WATER TEMPERATURES THERE IS AN INCREASING POTENTIAL FOR SEA FOG THIS AFTERNOON AND TONIGHT...PARTICULARLY WITHIN 10 MILES OF SHORE WHERE WATER TEMPERATURES ARE COLDEST. SOUTH WINDS CURRENTLY AROUND 10-12 KNOTS SHOULD INCREASE A FEW MORE KNOTS TODAY...BUT MAY ACTUALLY DIMINISH A LITTLE THIS EVENING AS AN AREA OF DYING CONVECTION ARRIVES AND THE PRESSURE GRADIENT IS DISRUPTED. REGARDLESS...WINDS SHOULD BUILD BACK UP TOWARD 12-15 KNOTS OVERNIGHT. SEAS ARE STILL A BIT HIGHER THAN WIND SPEEDS ALONE WOULD SUGGEST...COURTESY OF THE HUGE LOW THAT MOVED NORTH THROUGH THE WESTERN ATLANTIC A FEW DAYS AGO. AT THE FRYING PAN SHOALS BUOY THERE IS STILL A SMALL 14 SECOND EAST SWELL PRESENT...WHICH WHEN ADDED TO THE SHORTER 6-SECOND PERIOD WIND WAVES TOTALS AROUND 4 FEET. TOTAL SEAS EVEN INSIDE 20 MILES SHOULD INCREASE ON TOWARD 4-6 FEET BY THIS EVENING. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW WILL APPROACH 20 KT SAT AS GRADIENT OVER THE WATERS IS PINCHED BETWEEN ADVANCING COLD FRONT AND HIGH PRESSURE. ANTICIPATE A LINE OF CONVECTION AHEAD OF THE FRONT WHICH WILL CROSS THE WATERS SAT EVE/NIGHT. OFFSHORE FLOW DEVELOPS BEHIND THE FRONT WITH GRADIENT AND DEVELOPING COLD ADVECTION KEEPING SPEEDS AROUND 20 KT. LITTLE CHANGE IN THE GRADIENT SUN AS HIGH BUILDS KEEPS NORTHWEST WINDS A SOLID 20 KT FOR MUCH OF THE DAY. OFFSHORE FLOW SLOWLY WEAKENS SUN NIGHT...DROPPING TO 15 KT BY THE END OF THE PERIOD...AS GRADIENT RELAXES. SEAS 4 TO 6 FT EXPECTED SAT INTO SUN WHEN OFFSHORE COMPONENT DROPS SEAS TO 3 TO 5 FT. CONTINUED OFFSHORE FLOW COMBINED WITH REDUCTION IN SPEEDS SUN NIGHT WILL DROP SEAS TO 2 TO 4 FT BY THE END OF THE PERIOD. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...OFFSHORE FLOW AROUND 15 KT AT THE START OF THE PERIOD WILL DECREASE DURING MON AS HIGH PRESSURE MOVES OVER HEAD. SPEEDS WILL DROP UNDER 10 KT BY MON EVENING...BECOMING LIGHT AND VARIABLE MON NIGHT. HIGH SHIFTS OFFSHORE FOR TUE WITH RETURN FLOW SLOWLY RISING INTO THE 10 TO 15 KT RANGE LATE TUE AND TUE NIGHT. SEAS WILL RUN 2 TO 3 FT FOR A MAJORITY OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT SATURDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...III LONG TERM...III AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
953 AM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATER TODAY AND THEN STALL TO THE NORTH TONIGHT. DEVELOPING LOW PRESSURE MOVING ACROSS TO THE NORTH WILL PULL THE FRONT THROUGH THE AREA SATURDAY NIGHT. THE LOW WILL CONTINUE DEEPENING AS IT MOVES TO THE NORTHEAST SUNDAY AND SUNDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE WEST THROUGH MONDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 945 AM FRIDAY...TEMPERATURES HAVE WARMED VERY QUICKLY THIS MORNING WITH MOST AREAS ALREADY WELL INTO THE 60S. AS A RESULT...HAVE RAISED MAXIMUM TEMPERATURES A COUPLE OF DEGREES...ESPECIALLY ALONG THE SOUTH COAST. CLOUDS WILL CONTINUE TO INCREASE DURING THE AFTERNOON...BUT RAP AND 4KM WRF MODELS HOLD OFF ANY PRECIPITATION UNTIL AFTER 21Z OVER THE WESTERN COASTAL PLAINS COUNTIES. EXPECT A BROKEN LINE OF SHOWERS...BUT INSTABILITY WILL BE MARGINAL FOR ANY THUNDER LATE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... AS OF 430 AM FRIDAY...INCREASING MSTR AND SHRT WV ACTIVITY WILL PRODUCE HIGHER THREAT OF SHOWERS TONIGHT...WITH TSTM MENTION LIMITED TO COAST. GENERALLY CONTINUED PREVIOUS FCST OF POPS 50% COAST TO 70% INLAND THIS EVENING...AND 60%-70% ALL ZONES OVERNIGHT. SRLY FLOW AND CLOUD COVER WILL KEEP TEMPS MID 50S TO AROUND 60. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 4 AM FRI...UNSETTLED PATTERN TO START THE LONG TERM PERIOD THIS WEEKEND...THEN DRY AND SEASONABLY WARM FOR NEXT WEEK. SHORT WAVE TROUGH ACROSS CENTRAL CONUS TODAY WILL AMPLIFY THROUGH SATURDAY AND CLOSE OFF A MID LEVEL VORT SAT EVENING. MODELS COMING IN BETTER AGREEMENT ON THIS SYNOPTIC SETUP AS WELL AS TIMING OF THE FEATURES. THE NEUTRAL TILT CLOSED LOW WILL PROMOTE SFC LOW DEVELOPMENT OVER CENTRAL NC SAT EVENING. AHEAD OF IT...INC SW LLJ WILL FURTHER INC MOISTURE ADVECTION INTO E NC. BNDRY LAYER STREAMLINES SUGGEST MOISTURE CONVERGENCE WILL BE MAXIMIZED SAT EVENING...WITH BEST CHANCE OF WIDESPREAD RAIN SHOWERS OCCURRING THEN. AHEAD OF THE SYSTEM...OCNL SHOWERS WITH EMBEDDED THUNDER WILL OCCUR DURING THE DAY SAT. GFS ENSEMBLES CLUSTER FAIRLY WELL WITH SFC LOW PLACEMENT ACROSS NC TO SOUTHERN VA BETWEEN 00Z AND 06Z SUN. THE 28/00Z ECM IS ALSO FAVORING THIS GENERAL POSITIONING OF THE LOW. AS FAR AS SVR POTENTIAL IS CONCERNED...WIDESPREAD CLOUDINESS AND RAIN SHOWER ACTIVITY WILL ACT TO LIMIT DESTABILIZATION DURING THE DAY SAT...AND NOT EXPECTING MUCH IN WAY OF ORGANIZED CONVECTION. NEVERTHELESS...BULK SHEAR WILL BE SUFFICIENT FOR A FEW STORMS TO BECOME STRONG TO SEVERE WITH MAIN THREAT ISOLATED DAMAGING WINDS. GFS AND NAM INDICATE SFC WINDS BECOME BACKED SSE SAT EVENING AS H85-H90 FLOW REMAINS SW. THIS WOULD PRODUCE FAIR AMOUNT OF LOW LEVEL TURNING/0-3KM HELICITY. SHOULD ANY STORMS BECOME MORE ORGANIZED...CANNOT RULE OUT AN ISOLATED TORNADO THREAT ESP LATE SAT AFTERNOON THROUGH EARLY EVENING BEFORE LOW PULLS EAST AND SFC WINDS VEER SW TO W. RAIN SHOWERS WILL DECREASE SAT NIGHT AS MOISTURE AND LIFT SHIFT EAST WITH SFC EXITING SFC LOW. TEMPS WILL BE MILD MOST OF THE NIGHT BEFORE WINDS BECOME W TO EVENTUALLY NW BY LATE SAT NIGHT AND ALLOW TEMPS TO COOL TO THE LOW 50S. UPR LEVEL VORT WILL SLOWLY MIGRATE EAST THROUGH THE DAY SUNDAY...AND HAVE CONTINUED TO WEIGHT ECMWF SOLN WHICH WOULD KEEP WIDESPREAD LOW CLOUDS AND NUMEROUS SHOWERS ACROSS E NC THROUGH THE FIRST HALF OF SUNDAY. HAVE INC POPS TO LIKELY ACROSS THE NE ZONES...AND RETAINED HIGH CHANCE SCT WORDING FURTHER S AND W. TEMPS WILL ALSO BE ON THE COOL SIDE WITH THE WIDESPREAD CLOUDS AND SHOWER ACTIVITY WITH MOST AREAS IN THE MID 50S...WITH SOME LOW 50S OBX. DRAMATIC CLEARING OCCURS SUN NIGHT AS UPR LOW MOVES OUT TO SEA AND TEMPS SEASONABLY COOL IN THE UPR 30S/LOW 40S FOR LOWS MON MORNING. VERY DRY AIRMASS FOR MONDAY AS STRONG SUBSIDENCE AND BUILDING HIGH PRES MOVE INTO THE AREA. 1000-850MB RH VALS PLUMMET TO THE 20% RANGE ACCORDING TO THE ECM. WILL HAVE TO MONITOR FOR POTENTIAL FIRE WEATHER CONCERNS. TEMPS WILL REBOUND TO THE MID/UPR 60S. SPRAWLING SFC HIGH PRES WITH QUASI ZONAL FLOW WILL PRODUCE PLEASANTLY DRY AND WARM CONDITIONS THROUGH THE MID WEEK TIME PERIOD AND BEYOND WITH TEMPS WARMING TO THE MID/UPR 70S TO NEAR 80 BY THURSDAY. NEXT SYSTEM MAY AFFECT THE REGION FRIDAY INTO THE WEEKEND. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 12Z SATURDAY/... AS OF 730 AM FRIDAY...VFR CONDITIONS WILL PREVAIL INTO THIS AFTN...THEN MVFR CIGS/VSBYS EXPECTED WITH SHRA DURING EVENING LINGERING INTO OVERNIGHT. PRE-FRONTAL WARM SECTOR CONDITIONS EXPECTED DURING THE TAF PERIOD WITH HIGH PRES OFFSHORE AND COLD FRONT APPROACHING FROM W. SCT-BKN SCU WILL DEVELOP THROUGH MORNING HOURS WITH INCREASING SRLY FLOW BUT CIGS EXPECTED TO REMAIN ABOVE 3K FT. ISOLD SHRA PSBL INLAND LATE MORNING BUT BETTER COVERAGE LIKELY DURING AFTN AND EVENING WITH CIGS AND VSBYS LOWERING TO MVFR. MOIST LOW LVLS WILL RESULT IN CIGS LOWERING TO AROUND 1K FT FOR INLAND SITES OVERNIGHT. SRLY WINDS WILL GUST UP TO 20-25 KT THIS AFTN. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 4 AM FRI...MVFR OR LOWER IN NUMEROUS SHOWERS AND EMBEDDED THUNDER SAT THROUGH SAT NIGHT. THE FRONT WILL MOVE OFF THE COAST EARLY SUNDAY WITH SURFACE WINDS VEERING FROM SOUTH SOUTHWEST TO NORTHWEST. SUB-VFR CONTINUES SUNDAY WITH SCATTERED TO NUMEROUS SHOWERS IN LINGERING WRAPAROUND MOISTURE. VFR RETURNS ON SUN NIGHT THROUGH MUCH OF NEXT WEEK AS LARGE HIGH PRES BUILDS IN BRINGING EXCELLENT FLYING CONDITIONS. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 955 AM FRIDAY...TIGHTENING PRES GRAD EXPECTED TO PRODUCE 15-20 KT WINDS OVER NEAR SHORE WATERS DURING THE AFTERNOON...WITH SEAS BUILDING TO 4-6 FT SRN WATERS...THUS CONTINUED SCA. WINDS WILL DIMINISH THIS EVENING AS GRADIENT WEAKENS...AND SEAS FALLING BELOW 6 FT AGAIN LATE TONIGHT. LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 4 AM FRI...POOR BOATING CONDITIONS SAT THROUGH THE FIRST PART OF NEXT WEEK. SW WINDS WILL INC ONCE AGAIN DURING THE DAY SAT TO 25 KT OR HIGHER...ESP THE SOUTHERN/CENTRAL WATERS...AND SEAS WILL INC TO 6 FT OR HIGHER. THE S TO SW WINDS WILL REMAIN STRONG THROUGH SAT EVENING AHEAD OF LOW PRES AND A COLD FRONT. THE LOW WILL MOVE OFFSHORE WITH THE COLD FRONT LATE SAT NIGHT AND WINDS TURNING TO THE W AND THEN NW BY SUN MORNING. THE OFFSHORE LOW WILL SLOWLY PUSH AWAY AND KEEP THE NW GRADIENT RATHER STRONG WITH SCA CONTINUING THROUGH THE DAY SUNDAY. WINDS WILL FINALLY DIMINISH ON MONDAY THOUGH LINGERING LARGE SWELL ABOVE 6 FT WILL CONTINUE ESP ACROSS NORTHERN/CENTRAL WATERS. CONDITIONS IMPROVE MON NIGHT AS GRADIENT RELAXES. WINDS WILL TURN SW BUT REMAIN LIGHT TUE THROUGH MID WEEK AS LARGE HIGH PRES MOVES TO THE SOUTH OF THE AREA. PLEASANT BOATING CONDITIONS EXPECTED DURING THIS TIME FRAME. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR AMZ156-158. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...TL AVIATION...JBM/TL MARINE...JBM/CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
654 AM EDT FRI MAR 28 2014 .SYNOPSIS... MUCH MORE MOIST AND WARMER AIR WILL BE IN PLACE AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. THE FRONT WILL MOVE ACROSS THE AREA SATURDAY NIGHT. THE RISK FOR SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE UNTIL PASSAGE OF THE COLD FRONT. SOME STORMS MAY BE STRONG TO SEVERE SATURDAY AND SATURDAY NIGHT. A BRIEF COOL DOWN WILL OCCUR BEHIND THE FRONT SUNDAY. HIGH PRESSURE NEXT WEEK WILL BRING DRY WEATHER WITH TEMPERATURES CLIMBING WELL ABOVE NORMAL. A COLD FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM FRIDAY...RETURN FLOW AROUND DEPARTING HIGH PRESSURE HAS TAKEN A FIRM HOLD ON THE AREA AND WE ARE BEGINNING TO SEE DEWPOINTS SURGE HIGHER...NOW UP TO THE MID AND UPPER 40S ALONG THE COAST...AND IN THE LOWER 40S FOR MOST INLAND LOCATIONS. TEMPS HAVE ALSO RISEN WITH THE APPROACH OF MORNING...IN THE MID AND UPPER 40S IN MOST LOCATIONS...TOPPING 50 DEGREES IN SOME COASTAL AREAS. DEEP S TO SW FLOW WILL BE IN PLACE THIS PERIOD AND THIS WILL BRING INCREASING MOISTURE AND TEMPERATURE WHICH WILL RESULT IN INCREASED INSTABILITY. PRECIPITABLE WATER VALUES WILL BE NEAR 1 INCH THIS MORNING...CLIMBING TO 1.25 TO 1.5 INCHES LATER TODAY AND TONIGHT. THE COLUMN SUFFICIENTLY SATURATES TO A DEPTH THAT DOES SUPPORT MEASURABLE PRECIPITATION. SHORTWAVE ENERGY IN THE MID LEVELS DOES APPROACH FROM THE W TODAY AND THEN ACROSS THE AREA TONIGHT. THERE IS SOME INDICATION THE ENERGY MAY SPLIT...WITH THE FORECAST AREA LYING IN BETWEEN THE BEST UPPER LEVEL SUPPORT. THERE IS ALSO SOME CONCERN THAT WIDESPREAD CONVECTION ALONG THE GULF COAST MAY SERVE TO ROB OR AT LEAST DELAY DEEPER MOISTURE RETURN. AN EXAMINATION OF INSTABILITY AND MID LEVEL LAPSE RATES DOES SUPPORT INCLUSION OF HIGHER POPS THIS PERIOD. MIXED LAYER CAPE VALUES DO CLIMB TO 300 J/KG WHILE SURFACE BASED VALUES REACH 500 TO 1000 J/KG. MID LEVEL LAPSE RATES DO REACH UP TO 7 DEG C/KM. SO ALTHOUGH WE ARE CONFIDENT MEASURABLE PRECIPITATION WILL OCCUR... THERE IS SOME UNCERTAINTY AS TO WHEN TO INCLUDE THE HIGHEST POPS. LOOKING AT THE MOST RECENT RADAR/SATELLITE DATA...THERE IS A LARGE AREA OF DEEP CONVECTION ONGOING ACROSS THE CENTRAL AND EASTERN GULF COASTAL AREAS. THIS SUGGESTS DEEPEST MOISTURE RETURN MAY BE DELAYED. EXTRAPOLATION FOR TIMING WOULD BRING THE HIGHEST RISK FOR SHOWERS AND THUNDERSTORMS INTO THE AREA TONIGHT...MORE LIKELY LATE TONIGHT WITH THE ARRIVAL OF AN UPPER LEVEL IMPULSE WORKING ITS WAY UP THE CAROLINA COAST. OF COURSE THIS DOES NOT PRECLUDE SHOWERS AND SOME THUNDERSTORMS TODAY OR THIS EVE AND HIGHER RESOLUTION MODELS ARE SHOWING CONVECTION BREAKING OUT WITH HEATING OF THE DAY WITH PERHAPS THE SEA BREEZE SERVING AS A FOCAL POINT. RAINFALL AMOUNTS WILL BE HIGHLY VARIABLE...BUT SOME LOCATIONS COULD RECEIVE AS MUCH AS THREE-QUARTERS OF AN INCH WITH ONE-QUARTER TO ONE-HALF INCH MORE COMMON...THESE AMOUNTS JUST THROUGH TONIGHT. THICKER CLOUD COVER WILL BE ARRIVING/DEVELOPING THROUGH THE DAY WITH MORE OR LESS CLOUDY SKIES EXPECTED DURING THE AFTERNOON AND TONIGHT. ALSO...AS DEWPOINTS CREEP HIGHER...WE SHOULD BEGIN TO SEE SEA STRATUS/SEA FOG DEVELOP...PERHAPS IMPINGING ONTO THE IMMEDIATE COAST IN SOUTHERLY FLOW LATE DAY AND ESPECIALLY TONIGHT. HIGH TEMPS WILL BE IN THE LOWER TO MID 70S TODAY...BUT THE SEABREEZE WILL KEEP COASTAL AREAS IN THE MID AND UPPER 60S. LOWS TONIGHT WILL BE BALMY AS COMPARED TO RECENT NIGHTS...UPPER 50S TO AROUND 60 DEGREES. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SURFACE LOW AND MID LEVEL TROUGH WILL BE WEST OF THE AREA AT THE START OF THE PERIOD WITH THE REGION SOLIDLY IN THE WARM SECTOR. SEVERAL FACTORS APPEAR TO BE IN PLACE SUPPORTING CONVECTION SAT INTO SAT NIGHT. STRENGTHENING MID LEVEL SOUTHWEST FLOW WILL CONTINUE TO PUMP MOISTURE INTO THE REGION. FORECAST SOUNDINGS SHOW PRECIPITABLE WATER VALUES CLOSE TO 1.5 INCH. DIURNAL INSTABILITY WILL ALSO BE PRESENT WITH HIGHS EXPECTED TO CLIMB INTO THE LOWER 70S IN MOST AREAS. LOW LEVEL CONVERGENCE ALONG THE RESULTANT SEA BREEZE MAY INITIATE CONVECTION IN THE AFTERNOON. ALOFT THE APPROACHING 5H TROUGH WILL ENHANCE MID LEVEL LAPSE RATES BUT THE UNKNOWN FACTOR AT THIS POINT REMAINS WHAT IMPACT POTENTIAL CONVECTION IN THE NORTHEAST GULF OF MEXICO WILL HAVE ON INSTABILITY SHOWERS/THUNDERSTORMS. FARTHER WEST A LINE OF CONVECTION SHOULD BE DEVELOPING ASSOCIATED WITH THE ADVANCING COLD FRONT. THIS LINE WILL MOVE INTO WHAT SHOULD BE A MOIST/UNSTABLE ENVIRONMENT LATE SAT AND PUSH OFF THE COAST SAT NIGHT. ALTHOUGH THE FRONT WILL HAVE PLENTY OF LOW LEVEL CONVERGENCE AND MID LEVEL SUPPORT THERE IS SOME QUESTION AS TO THE STATE OF THE ATMOSPHERE IT WILL BE MOVING INTO. THE CONVECTIVE LINE ASSOCIATED WITH THE FRONT MAY END UP WEAKENING AS IT MOVES INTO THE REGION IF EARLIER AFTERNOON CONVECTION IS MORE WIDESPREAD AND USES UP A LOT OF THE AVAILABLE INSTABILITY. ON THE OTHER HAND SHOULD THE GULF CONVECTION BE ABLE TO SUPPRESS MUCH OF THE ACTIVITY DURING THE FIRST HALF OF SAT THE COLD FRONT WOULD HAVE PLENTY OF INSTABILITY TO WORK WITH. SO IT IS NOT SO MUCH A QUESTION OF WILL IT RAIN...BUT MORE OF A QUESTION OF WHEN WILL IT RAIN. SEVERE WEATHER THREAT PERSISTS...ALTHOUGH WITH CAVEATS. LOW LEVEL JETTING WILL BE WEAK FOR MUCH OF THE DAY BEFORE INCREASING TO 30 TO 35 KT JUST AHEAD OF THE FRONT. THE MAIN THREAT WOULD BE DAMAGING WIND...ENHANCED BY STORMS MOVING CLOSE TO 30 MPH. IF STRONG/SEVERE STORMS DEVELOP THEY ARE LIKELY TO DO SO WITH THE LINE OF CONVECTION AHEAD OF THE FRONT...AGAIN ASSUMING DIURNAL DRIVEN CONVECTION IS LIMITED IN SCOPE DURING THE DAY SAT. COLD FRONT PUSHES OFF THE COAST LATE SAT NIGHT WITH THE MID LEVEL TROUGH FOLLOWING ON SUN. COLD ADVECTION BEHIND THE FRONT WILL DROP SUN TEMPS BELOW CLIMO...BUT COLD AIR WILL BE A LITTLE TOO LATE TO HAVE A SIGNIFICANT IMPACT ON SAT NIGHT LOWS WHICH WILL END UP NEAR TO SLIGHTLY ABOVE CLIMO. SUN SHOULD BE DRY WITH DEEP NORTHWEST FLOW BEHIND THE TROUGH DROPPING PWATS UNDER .5 INCH FOR SUN AM AND UNDER .25 INCH BY SUN EVENING. GRADIENT RELAXES SUN NIGHT BUT HIGH REMAINS WEST OF THE AREA THROUGH THE END OF THE PERIOD SO SUN NIGHT WILL NOT BE AN IDEAL RADIATIONAL COOLING NIGHT. STILL LOWS END UP BELOW CLIMO. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LOW AMPLITUDE MID LEVEL RIDGING AND SPRAWLING SURFACE HIGH WILL KEEP THE AREA DRY AND SEASONABLE THROUGH THE PERIOD. COOLEST DAY WILL BE MON WITH SURFACE HIGH DIRECTLY OVERHEAD. HIGH THEN DRIFTS OFFSHORE TUE THROUGH THU BRINGING SEVERAL DAYS OF BEAUTIFUL SPRING WEATHER. PREVIOUSLY MEDIUM RANGE GUIDANCE HAD BEEN MOVING A DRY COLD FRONT ACROSS THE AREA TUE NIGHT INTO WED. NOW THAT GUIDANCE IS SUGGESTING MORE MID LEVEL AMPLIFICATION THIS SEEMS UNLIKELY AND IN FACT THE 00Z GUIDANCE IS BACKING OFF ON THE DRY FRONT. TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO MON TRANSITION TO ABOVE CLIMO MON NIGHT THROUGH THE END OF THE PERIOD. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...RETURN FLOW WILL COMMENCE SHORTLY. HAVE LEANED FAIRLY HEAVILY ON THE HRRR EARLY...WITH SHOWERS POPPING UP ALONG THE MYRTLES BY LATE MORNING. INCREASING SOUTHERLY GRADIENT WILL CAUSE WINDS TO GUSTS OVER 20 KTS AT TIMES...ESPECIALLY ALONG THE COAST. SCATTERED SHOWERS WILL GIVE WAY TO MORE WIDESPREAD RAIN THIS EVENING AS DEEP MOISTURE MOVES INTO THE REGION. RAIN CHANCES WILL BE HIGHEST INLAND THIS EVENING...SPREADING TO THE COAST A FEW HOURS LATER. CEILINGS ARE A BIT PROBLEMATIC...BUT WILL GO FOR MVFR PREDOMINATELY WITH POCKETS OF IFR POSSIBLE. EXTENDED OUTLOOK...SHOWERS AND T-STORMS WITH MVFR/TEMPO IFR CONDITIONS OVERNIGHT AND ON SATURDAY. VFR SUNDAY THROUGH TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM FRIDAY...THE PRESSURE GRADIENT BETWEEN A LARGE AREA OF HIGH PRESSURE OFFSHORE AND A TROUGH OF LOW PRESSURE TO OUR W WILL BE TIGHTEST TONIGHT...ESPECIALLY LATE TONIGHT AND SAT AS THE TROUGH BEGINS TO MAKE ITS EASTWARD PUSH. THUS THIS IS WHEN THE STRONGEST WINDS ARE EXPECTED ACROSS THE WATERS. THE STRONGEST WINDS ARE EXPECTED ACROSS THE OUTERMOST WATERS AND EASTWARD WHERE SEA SURFACE TEMPS ARE MUCH HIGHER THAN ACROSS THE NEAR SHORE WATERS...THUS ALLOWING FOR THE GREATEST MIXING. WIND SPEEDS WITHIN 20 NM OF THE COAST WILL BE AS HIGH AS 15 TO 20 KT. PERSISTENTLY HIGHER SOUTH WINDS OFFSHORE WILL ALLOW SEAS TO BUILD AND EXPECT THE 6 FT THRESHOLD WILL BE MET ACROSS PORTIONS OF THE OUTER WATERS AS EARLY AS THIS AFTERNOON AND MORESO TONIGHT...NECESSITATING A SMALL CRAFT ADVISORY WHICH WILL BE RAISED AT THIS TIME. FINALLY...HIGHER DEWPOINTS ADVECTING NORTHWARD AHEAD OF AN APPROACHING TROUGH SHOULD ALLOW FOR THE DEVELOPMENT OF SEA FOG...LIKELY MOST PREVALENT OVERNIGHT. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW WILL APPROACH 20 KT SAT AS GRADIENT OVER THE WATERS IS PINCHED BETWEEN ADVANCING COLD FRONT AND HIGH PRESSURE. ANTICIPATE A LINE OF CONVECTION AHEAD OF THE FRONT WHICH WILL CROSS THE WATERS SAT EVE/NIGHT. OFFSHORE FLOW DEVELOPS BEHIND THE FRONT WITH GRADIENT AND DEVELOPING COLD ADVECTION KEEPING SPEEDS AROUND 20 KT. LITTLE CHANGE IN THE GRADIENT SUN AS HIGH BUILDS KEEPS NORTHWEST WINDS A SOLID 20 KT FOR MUCH OF THE DAY. OFFSHORE FLOW SLOWLY WEAKENS SUN NIGHT...DROPPING TO 15 KT BY THE END OF THE PERIOD...AS GRADIENT RELAXES. SEAS 4 TO 6 FT EXPECTED SAT INTO SUN WHEN OFFSHORE COMPONENT DROPS SEAS TO 3 TO 5 FT. CONTINUED OFFSHORE FLOW COMBINED WITH REDUCTION IN SPEEDS SUN NIGHT WILL DROP SEAS TO 2 TO 4 FT BY THE END OF THE PERIOD. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...OFFSHORE FLOW AROUND 15 KT AT THE START OF THE PERIOD WILL DECREASE DURING MON AS HIGH PRESSURE MOVES OVER HEAD. SPEEDS WILL DROP UNDER 10 KT BY MON EVENING...BECOMING LIGHT AND VARIABLE MON NIGHT. HIGH SHIFTS OFFSHORE FOR TUE WITH RETURN FLOW SLOWLY RISING INTO THE 10 TO 15 KT RANGE LATE TUE AND TUE NIGHT. SEAS WILL RUN 2 TO 3 FT FOR A MAJORITY OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT SATURDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...RJD SHORT TERM...III LONG TERM...III AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
936 PM CDT SAT MAR 29 2014 .UPDATE... ISSUED AT 936 PM CDT SAT MAR 29 2014 MADE SOME ADDITIONAL TWEAKS TO POPS/WX. MOST OF THE RETURNS IN THE NORTHERN CWA HAVE NOT YET BEEN REACHING THE GROUND...BUT ROLLA JUST OUTSIDE THE CWA HAS STARTED REPORTING RAIN. CONTINUED TO KEEP SOME 20-40 POPS IN THE NORTHERN COUNTIES AND ADJUSTED THEM A BIT SOUTH TO COUNT FOR RADAR TRENDS TO OUR WEST AS WELL AS THE HRRR AND RAP RUNS. CONTINUE TO THINK THAT SOUTH WINDS WILL KEEP TEMPS UP AND TYPE AS RAIN FOR NOW. UPDATE ISSUED AT 634 PM CDT SAT MAR 29 2014 MADE A FEW MINOR TWEAKS TO POPS ALONG THE NORTHERN BORDER...BUT NO MAJOR CHANGES FOR THIS EVENING. THE CHANCE FOR A FEW RAIN SHOWERS IN THE NORTH WILL CONTINUE AND SOUTH WINDS WILL CONTINUE TO KEEP TEMPS UP. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 342 PM CDT SAT MAR 29 2014 FAIRLY QUIET THIS PERIOD AND MODELS IN DECENT AGREEMENT. VERY WARM AIRMASS WILL PROPAGATE ACROSS THE REGION TONIGHT...WITH MIN TEMPS AROUND THE FREEZING MARK. AN UPPER WAVE SHOULD BRING SCATTERED SHOWERS NEAR THE INTERNATIONAL BORDER TONIGHT. ON SUNDAY...COLDER AIRMASS BEGINS TO MOVE INTO THE WESTERN FA AS THE WINTER STORM TO THE WEST ORGANIZES AND APPROACHES THE REGION. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 342 PM CDT SAT MAR 29 2014 SUNDAY NIGHT-TUESDAY...THE LARGE WINTER STORM IS STILL ON TRACK TO HIT THE REGION (MOSTLY ON MONDAY). THE 12Z MODELS HAVE TRENDED SLIGHTLY SLOWER (AND NORTHWARD WITH THE HEAVIEST SNOWFALL). THE ECMWF REMAINS THE SLOWEST/FURTHEST NORTH...WHILE THE GFS IS FURTHEST SOUTH WITH THE HEAVIEST SNOWFALL (BUT STILL WITHIN THE FA). THE GEM/UKMET ARE SOMEWHERE IN THE MIDDLE...AND AT THIS POINT MAKE THE MOST SENSE. THE NAM (ALTHOUGH SIMILAR WITH QPF) IS THE FAST OUTLIER AND HAS BEEN DISCOUNTED. THE ECMWF IS ON THE NORTHERN EDGE OF THE ENSEMBLE ENVELOPE...AND WOULD EXPECT THIS SOLUTION TO TREND SLIGHTLY SOUTH WITH THE HEAVIEST QPF OVER THE NEXT FEW MODEL RUNS. AT ANY RATE...THE INGREDIENTS ARE IN PLACE FOR HEAVY SNOW SOMEWHERE...DEPENDING ON THE EXACT TRACK OF THIS SYSTEM. AMOUNTS WITHIN THIS HEAVY SNOW AREA COULD AMOUNT TO A FOOT OR MORE...WITH WIDESPREAD SNOWFALL OF 6 TO 12 INCHES APPEARING LIKELY (THE NORTHERN AND SOUTHERN EDGE OF THIS SNOWFALL AREA WILL BE CHALLENGING). THE SLOWER TREND OF THE MODELS HAS INCREASED THE EXPECTED NORTHERLY WINDS ON MONDAY. NO MATTER WHICH MODEL SOLUTION (EXCEPT THE FASTER NAM) YOU LOOK AT...ANTICIPATE SPEEDS AROUND 30 KNOTS GIVEN HIGH WIND INGREDIENTS AND MOS GUIDANCE. CONFIDENCE HAS INCREASED IN BLIZZARD CONDITIONS SOMEWHERE WITHIN THE FA...AND WILL `UPGRADE` THE WINTER STORM WATCH TO A BLIZZARD WATCH FOR THE `MOST LIKELY` BLIZZARD AREA. DEFINITELY NOT ENOUGH CONFIDENCE FOR A WARNING AT THIS POINT FOR ANY AREA AS THE EXACT TRACK AND SPEED OF THE SYSTEM WILL ULTIMATELY AFFECT P-TYPE...SNOW AMOUNTS...AND WIND SPEEDS. TUE NIGHT THROUGH SAT...SFC HIGH PRESSURE MOVES OVER THE FA ON TUE NIGHT KEEPING THINGS COOL AND DRY. BY WED THE FLOW TURNS MORE TO THE SOUTHWEST WITH MODELS DIVERGING ON SOLUTIONS. THE 12Z GFS IS QUICKER AND BRINGS IN LIGHT SNOW ON WED WHILE THE ECMWF/GEM KEEP WED DRY. THESE DIFFERENCES CONTINUE INTO WED NIGHT WITH THE GFS MOVING THE LIGHT SNOW INTO THE NE FA AND THE ECMWF/GEM STILL NOT SHOWING MUCH OF ANYTHING. MORE POTENT SYSTEM LOOKING TO BE THU/THU NIGHT ALTHOUGH STILL NOT MUCH AGREEMENT BETWEEN THE MODELS. THE ECMWF SHOWS THE FURTHEST NORTH SOLUTION WHICH WOULD GIVE ANOTHER BATCH OF SNOW TO THE SOUTHERN FA. THE GFS IS THE FURTHEST SOUTH WITH THE WAVE WHILE THE GEM IS IN BETWEEN. WILL LEAVE LOW SNOW CHANCES ACROSS MAINLY THE SOUTHERN FA FOR NOW AND SEE IF MODELS COME INTO BETTER AGREEMENT LATER. TEMPS GENERALLY LOOK TO STAY ON THE COOLER SIDE THROUGHOUT BUT COULD BE GREATLY AFFECTED BY SNOW COVER. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 634 PM CDT SAT MAR 29 2014 VFR CONDITIONS WILL CONTINUE FOR MUCH OF THE PERIOD WITH INCREASING HIGH CLOUDS THAT WILL EVENTUALLY COME DOWN TO AROUND 5000 FT. THE STRONG SOUTH WINDS WILL DIMINISH SOMEWHAT LATER THIS EVENING...THEN SHIFT TO THE NORTHWEST AT SOME POINT TOMORROW MORNING. BROUGHT SOME MVFR CIGS INTO KDVL BUT THINK THE TRUE LOWER CIGS WILL HOLD OFF FOR A BIT LONGER ACROSS MUCH OF THE FORECAST AREA AND NOT COME IN UNTIL AFTER 00Z MONDAY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR NDZ027>030-038-039-049-052-053. WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR NDZ008-016-024-026-054. MN...BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR MNZ001>003-029-030-040. WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR MNZ004>009-013>017-022>024-027-028-031-032. && $$ UPDATE...JR SHORT TERM...TG LONG TERM...GODON/TG AVIATION...JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
948 AM EDT FRI MAR 28 2014 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL PULL A COLD FRONT EAST ACROSS THE AREA TODAY. ANOTHER LOW PRESSURE SYSTEM WILL TRACK THROUGH THE TENNESSEE AND LOWER OHIO VALLEY ON SATURDAY. HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL EXPAND SOUTH ON SUNDAY...THEN SHIFT EAST OF THE AREA ON MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A COLD FRONT WAS OVER NORTHWEST OHIO AND IT WILL REACH NORTHWEST PA THIS AFTERNOON. WINDS CAN STILL BE GUSTY AHEAD OF THE FRONT BUT BELOW WIND ADVISORY CRITERIA. SCATTERED SHOWERS WILL BE DEVELOPING THROUGH THE MORNING AND INTO THE AFTERNOON. TEMPERATURES ARE PEAKING NOW AND WILL SLOWLY FALL AFTER THE FRONTAL PASSAGE. PREVIOUS DISCUSSION... WINDS HAVE BEEN GUSTING BETWEEN 40-45 MPH (WITH EVEN A PEAK WIND TO 50 MPH AT FINDLAY) EARLY THIS MORNING ACROSS NW AND NORTH CENTRAL OHIO. THIS HAS BEEN OCCURRING WELL OUT AHEAD OF THE FRONT IN THE VICINITY OF THE LOW LEVEL JET. HAVE CONTEMPLATED ISSUING A WIND ADVISORY BUT WINDS SHOULD ONLY BE THAT STRONG FOR A COUPLE HOUR WINDOW AT ANY GIVEN LOCATION BEFORE DECREASING WITH GUSTS CLOSER TO 35 MPH AS WE HAVE SEEN UPSTREAM IN INDIANA AND EVEN NW OHIO NOW. THE RUC SHOWS A DECREASING TREND FOR THE LOW LEVEL JET AND THE HRRR HAS BEEN HIGHLIGHTING THE STRONGEST CORRIDOR OF WINDS FROM FDY/MNN/MFD TO CLE. WINDS SHOULD START TO DECREASE FROM MFD- CLE THROUGH 9 AM SO WILL HOLD OFF ON AN ADVISORY. NORTHEAST OHIO WILL STILL SEE WINDS INCREASE BUT HOPEFULLY GUSTS WILL NOT BE QUITE AS STRONG...HOLDING CLOSER TO 40 MPH FOR THE MOST PART. WINDS WILL GUST TO AROUND 40 MPH AGAIN WITH THE FRONTAL PASSAGE BUT THESE WILL ALSO BE BRIEF. EARLIER DISCUSSION... LOW PRESSURE CURRENTLY LOCATED OVER LAKE MICHIGAN WITH A COLD FRONT EXTENDING SOUTH ACROSS ILLINOIS. WINDS HAVE BEEN INCREASING AHEAD OF THE FRONT AND SEVERAL SITES IN INDIANA AND WESTERN OHIO HAVE BRIEFLY GUSTED TO AROUND 40 MPH. EXPECT TO SEE THE BREEZY WINDS EXPAND EASTWARD AND THROUGH THE EARLY MORNING HOURS WITH GUSTS IN THE 30-40 MPH RANGE...WITH LOCALLY HIGHER GUSTS TOWARDS ERIE PA WHERE DOWNSLOPING MAY ENHANCE THE WINDS. NOT ENTIRELY OUT OF THE QUESTION THAT WE MAY NEED A WIND ADVISORY FOR A FEW HOURS THIS MORNING IN ERIE BUT STILL LOOKING JUST A LITTLE TOO MARGINAL TO ISSUE AT THIS TIME AS WINDS TRY TO SHIFT TO MORE SSW WHICH IS LESS FAVORABLE. TEMPERATURES WILL PEAK IN THE LOW 50S THIS MORNING IMMEDIATELY AHEAD OF THE FRONT WHICH WILL REACH TOL AROUND 9 AM...CLE AROUND NOON AND ERI EARLY THIS AFTERNOON. TEMPERATURES WILL FALL INTO THE MID AND UPPER 40S BEHIND THE FRONT MOST AREAS THIS AFTERNOON. ONE MORE BAND OF SHOWERS EXTENDS FROM FINDLAY SOUTHWEST AHEAD OF THE MID-LEVEL DRY-SLOT. THIS AREA OF SHOWERS EXPECTED TO QUICKLY MOVE NORTHEAST ACROSS OHIO THIS MORNING....WITH JUST A SLIGHT CHANCE OF ADDITIONAL SHOWERS RE-DEVELOPING ALONG THE FRONT. THE AIR MASS DRIES OUT QUICKLY BY THIS AFTERNOON AS A SHORTWAVE RIDGE BUILD ALOFT. SKIES WILL START TO SCATTER OUT IN NW OHIO THIS AFTERNOON...POSSIBLY AS FAR EAST AS CLE/CAK BY SUNSET. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SKIES WILL CLEAR OUT THIS EVENING WITH NORTH TO NORTHEAST FLOW ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE BUILD OVER THE UPPER GREAT LAKES. LOWS WILL FALL INTO THE LOW 30S TONIGHT. THE FORECAST REMAINS A CHALLENGE FOR SATURDAY AS MODELS CONTINUE TO SHOW SPREAD WITH THERMAL PROFILES WHICH WILL HAVE AN EFFECT ON PRECIPITATION TYPE. SHORTWAVE ENERGY OBSERVED OVER THE ROCKY MOUNTAINS THIS MORNING WILL DEEPEN INTO A FAIRLY SHARP TROUGH AS IT CROSSES THE MISSISSIPPI VALLEY ON SATURDAY. A SURFACE LOW WILL DEEPEN AHEAD OF THIS FEATURE...TRACKING NORTHEAST FROM THE TENNESSEE TO LOWER OHIO VALLEY. FRONTOGENESIS WILL STRENGTHEN OVER THE AREA IN THE 850-700MB LAYER LEADING TO WIDESPREAD PRECIPITATION. THERE WILL BE A DRY NORTHERLY FLOW IN THE LOW LEVELS TO START THE DAY WHICH MAY SLIGHTLY DELAY PRECIPITATION. MODELS VARY WITH HOW MUCH WARM AIR WILL BE IN PLACE ALOFT TO START THE DAY WITH THE ECMWF ADVERTISING A WARM LAYER OF 1-3C NEAR 850MB WHILE THE GFS ALSO STARTS THE DAY OFF WARM IN THE EASTERN CWA...BUT QUICKLY COOLS THE COLUMN FROM WEST TO EAST. SUSPECT WE WILL SEE WESTERN AREAS MAKE A QUICK TRANSITION TO A WET SNOW ON SATURDAY MORNING WHILE RAIN IS MORE PREVALENT EAST OF ABOUT I-71. GOOD PRECIPITATION RATES ARE EXPECTED AS A NUMBER OF FACTORS COME TOGETHER...INCLUDING FAVORABLE JET DYNAMICS ALOFT. THE SNOWFALL FORECAST IS COMPLICATED GIVEN IT BEING A DAYTIME SNOW EVENT AT THE END OF MARCH. SNOW WILL ACCUMULATE BETTER ON GRASSY SURFACES THAN ROADWAYS...ESPECIALLY AS TEMPERATURES HOVER IN THE LOW TO MID 30S. THE SNOW WILL BE WET WHICH WILL LEAD TO MORE COMPACTION. HAVE GONE WITH A BLEND OF THE COOLER GFS/NAM AND WARMER ECMWF/GEM WITH REGARD TO PRECIP TYPE BUT LEANING TOWARDS THE LOWER ACCUMULATIONS GIVEN THE LIMITATIONS MENTIONED ABOVE. GOING WITH A PURE 00Z/GFS SOLUTION COULD YIELD AS MUCH AS 3-5 INCHES FOR A CORRIDOR FROM CLE/ERI AS SNOW STARTS TO ACCUMULATE MORE EFFICIENTLY AS WE HEAD TOWARDS SUNSET. THE GOING FORECAST ONLY CALLS FOR A COUPLE INCHES BUT MAY NEED TO BE RAMPED UP BASED ON LATER MODEL GUIDANCE. DID ADJUST HIGH TEMPERATURES DOWN A FEW DEGREES ON SATURDAY WITH LITTLE DIURNAL RISE. PRECIPITATION WILL COME TO AN END ON SATURDAY NIGHT WITH LITTLE INFLUENCE FROM LAKE ERIE GIVEN 850MB TEMPERATURES ONLY DROPPING TO AROUND -4C. HIGH PRESSURE THEN BUILDS OVER THE AREA ON SUNDAY WITH MOSTLY SUNNY SKIES. SOUTHERLY FLOW RETURNS ON MONDAY AHEAD OF THE NEXT SYSTEM WITH HIGHS IN THE UPPER 50S TO LOW 60S. && .LONG TERM /TUESDAY THROUGH THURSDAY/... THE MODELS CONTINUE TO BE SIMILAR IN THEIR FORECASTS WITH SOME MINOR DETAILS TO BE WORKED OUT. A COLD FRONT WILL CROSS THE AREA ON TUESDAY. THE ECMWF HAS BECOME SLOWER THAN THE OTHER MODELS AND CONSEQUENTLY IS WARMER (60S VERSUS 50S FOR HIGHS). WOULD RATHER REMAIN CONSERVATIVE AND NEAR THE CURRENT FORECAST UNTIL WE SEE A MORE DEFINITE TREND. THE NEXT PANHANDLE HOOK IS PROGGED TO COME OUT OF THE SOUTHERN PLAINS BY WEDNESDAY NIGHT AND MOVE TO THE GREAT LAKES ON THURSDAY. INCREASED THE CHANCE OF RAIN IN THE FORECAST FOR WEDNESDAY NIGHT AND THURSDAY. WE MAY TAKE A WHILE TO BREAK INTO THE WARM SECTOR WITH AN EAST FLOW PROGGED FOR A WHILE WEDNESDAY INTO THURSDAY SO DID NOT GO AS WARM AS IT COULD BE FOR HIGH TEMPS AND DID NOT MENTION THUNDER... THERE IS PLENTY OF TIME TO TREND THE FORECAST IN THAT DIRECTION IF NECESSARY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... WILL ALLOW FOR SHOWERS AT THE EASTERN TAF SITES KCAK KYNG KERI EARLY THIS MORNING. CANNOT RULE OUT A BRIEF SHOWER/SPRINKLE WHEN THE ACTUAL FRONT MOVES THROUGH MID MORNING THROUGH EARLY AFTERNOON BUT DID NOT INCLUDE IT IN THE FORECAST. CEILINGS WILL LOWER TO MVFR AFTER FRONTAL PASSAGE. GUSTY SOUTH WINDS WILL BECOME SOUTHWEST AND EVENTUALLY WEST...THEN DIMINISH QUICKLY LATE THIS AFTERNOON/EARLY EVENING. GUSTS 35 TO NEAR 40 KNOTS THIS MORNING. CLEARING AND VFR CONDITIONS WILL SPREAD FROM WEST TO EAST LATE THIS AFTERNOON AND THIS EVENING. MID AND HIGH CLOUDS WILL INCREASE SATURDAY MORNING. .OUTLOOK...NON VFR WILL REDEVELOP SAT AND PERSIST ACROSS NE OH/NW PA INTO SUNDAY. NON VFR POSSIBLE AGAIN TUE. && .MARINE... THE STRONG LOW LEVEL JET WILL BE OVER LAKE ERIE THIS MORNING BUT WITH THE LAKE STILL SO COLD IT IS UNLIKELY THE WIND WILL MIX DOWN TO THE SURFACE. SOUTH WINDS OF 20-30 KNOTS SHOULD DO IT THIS MORNING. THERE COULD BE BETTER MIXING AS THE FRONT CROSSES THE LAKE FROM MID MORNING THROUGH MID AFTERNOON AND AN OBSERVATION OR TWO NEAR 35 KNOTS IS POSSIBLE BUT DO NOT WANT TO ISSUE A GALE WARNING FOR AN ISOLATED/BRIEF EVENT. HIGH PRESSURE WILL BUILD IN QUICKLY TONIGHT. THE NEXT LOW PRESSURE SYSTEM WILL PASS SOUTH OF THE LAKE ON SATURDAY AND WINDS WILL VEER TO THE NORTH AND NORTHEAST. NNE WINDS COULD BECOME BRISK ON SATURDAY...THERE IS STILL SOME UNCERTAINTY ON THE TRACK AND STRENGTH OF THE LOW. HIGH PRESSURE IS EXPECTED TO SPREAD ACROSS THE EASTERN GREAT LAKES SUNDAY INTO MONDAY. THE NEXT LOW WILL TRACK ACROSS THE WESTERN GREAT LAKES BY MONDAY NIGHT WITH WINDS ON LAKE ERIE INCREASING WITH THE NEXT COLD FRONT ON TUESDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KEC NEAR TERM...KEC/KIELTYKA SHORT TERM...KEC LONG TERM...KOSARIK AVIATION...KOSARIK MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
737 AM EDT FRI MAR 28 2014 .SYNOPSIS... A LOW PRESSURE SYSTEM WILL PULL A COLD FRONT EAST ACROSS THE AREA TODAY. ANOTHER LOW PRESSURE SYSTEM WILL TRACK THROUGH THE TENNESSEE AND LOWER OHIO VALLEY ON SATURDAY. HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL EXPAND SOUTH ON SUNDAY...THEN SHIFT EAST OF THE AREA ON MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WINDS HAVE BEEN GUSTING BETWEEN 40-45 MPH (WITH EVEN A PEAK WIND TO 50 MPH AT FINDLAY) EARLY THIS MORNING ACROSS NW AND NORTH CENTRAL OHIO. THIS HAS BEEN OCCURRING WELL OUT AHEAD OF THE FRONT IN THE VICINITY OF THE LOW LEVEL JET. HAVE CONTEMPLATED ISSUING A WIND ADVISORY BUT WINDS SHOULD ONLY BE THAT STRONG FOR A COUPLE HOUR WINDOW AT ANY GIVEN LOCATION BEFORE DECREASING WITH GUSTS CLOSER TO 35 MPH AS WE HAVE SEEN UPSTREAM IN INDIANA AND EVEN NW OHIO NOW. THE RUC SHOWS A DECREASING TREND FOR THE LOW LEVEL JET AND THE HRRR HAS BEEN HIGHLIGHTING THE STRONGEST CORRIDOR OF WINDS FROM FDY/MNN/MFD TO CLE. WINDS SHOULD START TO DECREASE FROM MFD-CLE THROUGH 9 AM SO WILL HOLD OFF ON AN ADVISORY. NORTHEAST OHIO WILL STILL SEE WINDS INCREASE BUT HOPEFULLY GUSTS WILL NOT BE QUITE AS STRONG...HOLDING CLOSER TO 40 MPH FOR THE MOST PART. WINDS WILL GUST TO AROUND 40 MPH AGAIN WITH THE FRONTAL PASSAGE BUT THESE WILL ALSO BE BRIEF. EARLIER DISCUSSION... LOW PRESSURE CURRENTLY LOCATED OVER LAKE MICHIGAN WITH A COLD FRONT EXTENDING SOUTH ACROSS ILLINOIS. WINDS HAVE BEEN INCREASING AHEAD OF THE FRONT AND SEVERAL SITES IN INDIANA AND WESTERN OHIO HAVE BRIEFLY GUSTED TO AROUND 40 MPH. EXPECT TO SEE THE BREEZY WINDS EXPAND EASTWARD AND THROUGH THE EARLY MORNING HOURS WITH GUSTS IN THE 30-40 MPH RANGE...WITH LOCALLY HIGHER GUSTS TOWARDS ERIE PA WHERE DOWNSLOPING MAY ENHANCE THE WINDS. NOT ENTIRELY OUT OF THE QUESTION THAT WE MAY NEED A WIND ADVISORY FOR A FEW HOURS THIS MORNING IN ERIE BUT STILL LOOKING JUST A LITTLE TOO MARGINAL TO ISSUE AT THIS TIME AS WINDS TRY TO SHIFT TO MORE SSW WHICH IS LESS FAVORABLE. TEMPERATURES WILL PEAK IN THE LOW 50S THIS MORNING IMMEDIATELY AHEAD OF THE FRONT WHICH WILL REACH TOL AROUND 9 AM...CLE AROUND NOON AND ERI EARLY THIS AFTERNOON. TEMPERATURES WILL FALL INTO THE MID AND UPPER 40S BEHIND THE FRONT MOST AREAS THIS AFTERNOON. ONE MORE BAND OF SHOWERS EXTENDS FROM FINDLAY SOUTHWEST AHEAD OF THE MID-LEVEL DRY-SLOT. THIS AREA OF SHOWERS EXPECTED TO QUICKLY MOVE NORTHEAST ACROSS OHIO THIS MORNING....WITH JUST A SLIGHT CHANCE OF ADDITIONAL SHOWERS RE-DEVELOPING ALONG THE FRONT. THE AIR MASS DRIES OUT QUICKLY BY THIS AFTERNOON AS A SHORTWAVE RIDGE BUILD ALOFT. SKIES WILL START TO SCATTER OUT IN NW OHIO THIS AFTERNOON...POSSIBLY AS FAR EAST AS CLE/CAK BY SUNSET. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SKIES WILL CLEAR OUT THIS EVENING WITH NORTH TO NORTHEAST FLOW ON THE SOUTHERN PERIPHERY OF HIGH PRESSURE BUILD OVER THE UPPER GREAT LAKES. LOWS WILL FALL INTO THE LOW 30S TONIGHT. THE FORECAST REMAINS A CHALLENGE FOR SATURDAY AS MODELS CONTINUE TO SHOW SPREAD WITH THERMAL PROFILES WHICH WILL HAVE AN EFFECT ON PRECIPITATION TYPE. SHORTWAVE ENERGY OBSERVED OVER THE ROCKY MOUNTAINS THIS MORNING WILL DEEPEN INTO A FAIRLY SHARP TROUGH AS IT CROSSES THE MISSISSIPPI VALLEY ON SATURDAY. A SURFACE LOW WILL DEEPEN AHEAD OF THIS FEATURE...TRACKING NORTHEAST FROM THE TENNESSEE TO LOWER OHIO VALLEY. FRONTOGENESIS WILL STRENGTHEN OVER THE AREA IN THE 850-700MB LAYER LEADING TO WIDESPREAD PRECIPITATION. THERE WILL BE A DRY NORTHERLY FLOW IN THE LOW LEVELS TO START THE DAY WHICH MAY SLIGHTLY DELAY PRECIPITATION. MODELS VARY WITH HOW MUCH WARM AIR WILL BE IN PLACE ALOFT TO START THE DAY WITH THE ECMWF ADVERTISING A WARM LAYER OF 1-3C NEAR 850MB WHILE THE GFS ALSO STARTS THE DAY OFF WARM IN THE EASTERN CWA...BUT QUICKLY COOLS THE COLUMN FROM WEST TO EAST. SUSPECT WE WILL SEE WESTERN AREAS MAKE A QUICK TRANSITION TO A WET SNOW ON SATURDAY MORNING WHILE RAIN IS MORE PREVALENT EAST OF ABOUT I-71. GOOD PRECIPITATION RATES ARE EXPECTED AS A NUMBER OF FACTORS COME TOGETHER...INCLUDING FAVORABLE JET DYNAMICS ALOFT. THE SNOWFALL FORECAST IS COMPLICATED GIVEN IT BEING A DAYTIME SNOW EVENT AT THE END OF MARCH. SNOW WILL ACCUMULATE BETTER ON GRASSY SURFACES THAN ROADWAYS...ESPECIALLY AS TEMPERATURES HOVER IN THE LOW TO MID 30S. THE SNOW WILL BE WET WHICH WILL LEAD TO MORE COMPACTION. HAVE GONE WITH A BLEND OF THE COOLER GFS/NAM AND WARMER ECMWF/GEM WITH REGARD TO PRECIP TYPE BUT LEANING TOWARDS THE LOWER ACCUMULATIONS GIVEN THE LIMITATIONS MENTIONED ABOVE. GOING WITH A PURE 00Z/GFS SOLUTION COULD YIELD AS MUCH AS 3-5 INCHES FOR A CORRIDOR FROM CLE/ERI AS SNOW STARTS TO ACCUMULATE MORE EFFICIENTLY AS WE HEAD TOWARDS SUNSET. THE GOING FORECAST ONLY CALLS FOR A COUPLE INCHES BUT MAY NEED TO BE RAMPED UP BASED ON LATER MODEL GUIDANCE. DID ADJUST HIGH TEMPERATURES DOWN A FEW DEGREES ON SATURDAY WITH LITTLE DIURNAL RISE. PRECIPITATION WILL COME TO AN END ON SATURDAY NIGHT WITH LITTLE INFLUENCE FROM LAKE ERIE GIVEN 850MB TEMPERATURES ONLY DROPPING TO AROUND -4C. HIGH PRESSURE THEN BUILDS OVER THE AREA ON SUNDAY WITH MOSTLY SUNNY SKIES. SOUTHERLY FLOW RETURNS ON MONDAY AHEAD OF THE NEXT SYSTEM WITH HIGHS IN THE UPPER 50S TO LOW 60S. && .LONG TERM /TUESDAY THROUGH THURSDAY/... THE MODELS CONTINUE TO BE SIMILAR IN THEIR FORECASTS WITH SOME MINOR DETAILS TO BE WORKED OUT. A COLD FRONT WILL CROSS THE AREA ON TUESDAY. THE ECMWF HAS BECOME SLOWER THAN THE OTHER MODELS AND CONSEQUENTLY IS WARMER (60S VERSUS 50S FOR HIGHS). WOULD RATHER REMAIN CONSERVATIVE AND NEAR THE CURRENT FORECAST UNTIL WE SEE A MORE DEFINITE TREND. THE NEXT PANHANDLE HOOK IS PROGGED TO COME OUT OF THE SOUTHERN PLAINS BY WEDNESDAY NIGHT AND MOVE TO THE GREAT LAKES ON THURSDAY. INCREASED THE CHANCE OF RAIN IN THE FORECAST FOR WEDNESDAY NIGHT AND THURSDAY. WE MAY TAKE A WHILE TO BREAK INTO THE WARM SECTOR WITH AN EAST FLOW PROGGED FOR A WHILE WEDNESDAY INTO THURSDAY SO DID NOT GO AS WARM AS IT COULD BE FOR HIGH TEMPS AND DID NOT MENTION THUNDER... THERE IS PLENTY OF TIME TO TREND THE FORECAST IN THAT DIRECTION IF NECESSARY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... WILL ALLOW FOR SHOWERS AT THE EASTERN TAF SITES KCAK KYNG KERI EARLY THIS MORNING. CANNOT RULE OUT A BRIEF SHOWER/SPRINKLE WHEN THE ACTUAL FRONT MOVES THROUGH MID MORNING THROUGH EARLY AFTERNOON BUT DID NOT INCLUDE IT IN THE FORECAST. CEILINGS WILL LOWER TO MVFR AFTER FRONTAL PASSAGE. GUSTY SOUTH WINDS WILL BECOME SOUTHWEST AND EVENTUALLY WEST...THEN DIMINISH QUICKLY LATE THIS AFTERNOON/EARLY EVENING. GUSTS 35 TO NEAR 40 KNOTS THIS MORNING. CLEARING AND VFR CONDITIONS WILL SPREAD FROM WEST TO EAST LATE THIS AFTERNOON AND THIS EVENING. MID AND HIGH CLOUDS WILL INCREASE SATURDAY MORNING. .OUTLOOK...NON VFR WILL REDEVELOP SAT AND PERSIST ACROSS NE OH/NW PA INTO SUNDAY. NON VFR POSSIBLE AGAIN TUE. && .MARINE... THE STRONG LOW LEVEL JET WILL BE OVER LAKE ERIE THIS MORNING BUT WITH THE LAKE STILL SO COLD IT IS UNLIKELY THE WIND WILL MIX DOWN TO THE SURFACE. SOUTH WINDS OF 20-30 KNOTS SHOULD DO IT THIS MORNING. THERE COULD BE BETTER MIXING AS THE FRONT CROSSES THE LAKE FROM MID MORNING THROUGH MID AFTERNOON AND AN OBSERVATION OR TWO NEAR 35 KNOTS IS POSSIBLE BUT DO NOT WANT TO ISSUE A GALE WARNING FOR AN ISOLATED/BRIEF EVENT. HIGH PRESSURE WILL BUILD IN QUICKLY TONIGHT. THE NEXT LOW PRESSURE SYSTEM WILL PASS SOUTH OF THE LAKE ON SATURDAY AND WINDS WILL VEER TO THE NORTH AND NORTHEAST. NNE WINDS COULD BECOME BRISK ON SATURDAY...THERE IS STILL SOME UNCERTAINTY ON THE TRACK AND STRENGTH OF THE LOW. HIGH PRESSURE IS EXPECTED TO SPREAD ACROSS THE EASTERN GREAT LAKES SUNDAY INTO MONDAY. THE NEXT LOW WILL TRACK ACROSS THE WESTERN GREAT LAKES BY MONDAY NIGHT WITH WINDS ON LAKE ERIE INCREASING WITH THE NEXT COLD FRONT ON TUESDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KEC NEAR TERM...KEC SHORT TERM...KEC LONG TERM...KOSARIK AVIATION...KOSARIK MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
916 PM PDT THU MAR 27 2014 .SYNOPSIS...RAIN WILL INCREASE TONIGHT AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. WILL HAVE RAIN...HEAVY AT TIMES LATER TONIGHT AND FRIDAY. COOLER CONDITIONS WITH SHOWERS EXPECTED FRI NIGHT THROUGH SUN...WITH SNOW AT THE CASCADE PASSES. UNSETTLED WEATHER CONTINUES INTO NEXT WEEK. && .UPDATE...MADE MINOR CHANGES WITH THE EVENING UPDATE. HAVE ADDED A SLIGHT CHANCE FOR THUNDERSTORMS TO SW WASHINGTON AND THE NORTHER OREGON COAST RANGE FRIDAY AFTERNOON AND ACROSS THE ENTIRE PORTLAND FORECAST AREA SATURDAY AFTERNOON. ALSO INCREASED QPF ALONG THE COAST AND COAST RANGE A TAD FOR SATURDAY. OTHERWISE...PREVIOUS FORECAST IS ON TRACK WITH A COMPLEX LOW BRINGING ROUNDS OF RAIN AND MOUNTAIN SNOW THROUGH EARLY NEXT WEEK. THE FIRST SYSTEM OF INTEREST IS A WARM FRONT THAT WILL PRODUCE STEADY RAIN AND HIGH ELEVATION (ABOVE 5500 FEET) SNOW TONIGHT AND FRIDAY. THIS WILL BE CLOSELY FOLLOWED BY A COLD FRONT FRIDAY NIGHT AND SATURDAY. SNOW LEVELS WILL LOWER SATURDAY AFTERNOON WITH SNOW ACCUMULATIONS LIKELY FOR THE CASCADE PASSES. THERE IS A GOOD CHANCE THAT SMALL HAIL WILL ACCOMPANY MANY OF THE SHOWERS SATURDAY AFTERNOON.HARTLEY PREVIOUS SHORT TERM DISCUSSION...TODAY THROUGH SATURDAY... SHOWERS CONTINUE IN THE COOLER ONSHORE FLOW THIS AFTERNOON. THESE MAY STILL PACK SOME PUNCH...WITH A BRIEF DOWNPOUR. BUT SHOULD NOT BE AS INTENSE AS THOSE OVER THE PAST FEW DAYS. SHOWERS WILL DECREASE THIS EVENING AS THE UPPER LOW SHIFTS FURTHER INLAND OVER WASHINGTON. OCCASIONAL SNOW IN THE CASCADES AS THE PASSES...BUT NOT MUCH MORE WILL FALL...WITH A FEW MORE INCHES INTO THIS EVENING. WARM FRONT WILL PUSH INTO THE REGION FROM THE SW TONIGHT. DECENT ISENTROPIC LIFT STARTS LATER THIS EVENING. LOOKS GOOD THAT RAIN WILL DEVELOP ALONG THE CENTRAL OREGON COAST THIS EVENING...AND SPREAD N AND E OVERNIGHT. RAIN WILL BECOME HEAVY AT TIMES LATER TONIGHT AND CONTINUE ON FRI. STILL LOOKS LIKE GOOD 2 TO 5 INCHES OF RAIN...WITH HEAVIEST RAINFALL OVER THE OREGON MTNS. IN THE CASCADES...LIKELY 1 TO 3 INCHES OF RAIN. HOWEVER...WILL SEE THIS START AS SNOW WITH 2 TO 5 INCHES ACCUMULATING OVERNIGHT BEFORE TURNING TO RAIN LATE TONIGHT/EARLY FRI AS SNOW LEVELS CLIMB TO NEAR 6000 FT. BUT ABOVE 6000 FT...COULD GET UP TO 1 FOOT OF SNOW LATER TONIGHT AND FRI. NOT FLOODING EXPECTED AT THIS TIME...BUT RIVERS WILL SEE SHARP RISES FRI DUE TO THE RAIN. MODELS MOSTLY AGREE THAT AXIS OF HEAVIEST RAIN SHIFTS INTO SW OREGON/NW CALIF ON LATER FRI AFTERNOON AND EVENING. RAIN WILL TRANSITION TO SHOWERS FRI EVENING AS THE FRONT DROPS SLOWLY SOUTHWARD INTO SW OREGON. OTHER CONCERN WILL BE SOMEWHAT ELEVATED POTENTIAL FOR MUD/LANDSLIDES DUE TO SATURATED SOILS...PRIMARILY ALONG THE COAST...THROUGH COAST RANGES AND IN COLUMBIA GORGE ON FRI AND INTO FRI NIGHT. EVEN THROUGH PRES GRADIENTS INCREASE TONIGHT AND FRI AM...STILL WILL NOT BE ENOUGH TO CREATE ANY WIDESPREAD PROBLEMS. THIS SAID IT SEEMS REASONABLE TO EXPECT GUSTS 40 TO 45 MPH ON THE COAST AND 25 TO 35 MPH FROM THE COAST RANGE INLAND. THE UPPER TROUGH WILL REMAIN IN PLACE THROUGH SATURDAY BRINGING PERIODIC SHOWER BANDS WITH SNOW LEVELS LOWERING TO 4000 FEET ONCE AGAIN. MAY NEED TO CONSIDER ANOTHER ROUND OF MARGINAL CASCADE SNOW ADVISORIES DEPENDING ON THE QPF DETAILS THAT EMERGE. SATURDAY WILL BE A COOL SPRING DAY...WITH PLENTY OF SHOWERS AND EVEN ISOLATED THUNDERSTORMS WITH SMALL HAIL. WITH SNOW LEVELS STILL DOWN...WILL CONTINUE TO SEE SNOW IN THE CASCADES. ROCKEY. .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... SATURDAY NIGHT THROUGH WEDNESDAY... EXPECT MORE OF THE SAME COOL AND WET WEATHER FOR THE EXTENDED FCST PERIOD. A BROAD UPPER LEVEL TROUGH WILL REMAIN OVER THE NE PAC OVER THE WEEKEND AND INTO EARLY NEXT WEEK. NO SIGNIFICANT IMPACTS ARE EXPECTED DURING THIS TIME...BUT PERIODIC WAVES ROTATING THROUGH THE TROUGH WILL BRING TIMES OF ENHANCED SHOWER ACTIVITY. MUCH OF THE PRECIPITATION SHOULD FALL AS SNOW AT THE CASCADE PASSES...BUT ACCUMULATIONS SHOULD BE RELATIVELY LIGHT. OTHERWISE...EXPECT PLENTY OF CLOUDS AND TEMPS A FEW DEGREES BELOW NORMAL. CONFIDENCE IS INCREASING THAT A MORE ORGANIZED FRONTAL SYSTEM WILL MOVE INTO THE PAC NW TOWARDS THE MIDDLE OF NEXT WEEK. PYLE && .AVIATION...EXPECT MAINLY VFR CONDITIONS THIS EVENING TO TRANSITION TO A MIX OF IFR AND MVFR CONDITIONS. THESE LOWER FLIGHT CONDITIONS SHOULD PERSIST FOR MUCH OF FRIDAY...WITH NORTHERN TAF SITES TRENDING VFR EARLIER IN THE AFTERNOON THAN SOUTHERN TAF SITES. KPDX AND APPROACHES...STEADIER RAIN WILL BEGIN TO SPREAD IN AFTER 09Z AND CONTINUE FOR MUCH OF FRIDAY. EXPECT A LOT OF MVFR CONDITIONS LATE TONIGHT AND FRIDAY WITH HIGH END IFR CONDITIONS POSSIBLE FOR BRIEF PERIODS. EAST WINDS SHOULD KEEP CONDITIONS MORE ON THE MVFR SIDE THOUGH. /NEUMAN && .MARINE...WINDS HAVE BEEN SLOWER TO INCREASE THAN MODELS HAVE PREDICTED THUS FAR. NONETHELESS...BUOY 50 IS STARTING TO PICK UP AND SHOULD INCREASE INTO LOW END GALE FORCE LEVELS AFTER MIDNIGHT. THE LATEST RAP MODEL WINDS SHOULD LOW END GALE FORCE WINDS SURGING UP THE INNER WATERS TO THE COLUMBIA RIVER MOUTH. HOWEVER...THE NAM...LOCAL WRF MODEL AND HRRR ALL SEEM TO SUGGEST THE HIGHER GUSTS WILL REMAIN OVER THE CENTRAL OREGON WATERS. AS A RESULT...KEPT THE INHERITED SMALL CRAFT ADVISORIES IN PLACE FOR THE NORTHERN WATERS AND THE GALE WARNING FOR THE CENTRAL OREGON WATERS...BUT AM A BIT WORRIED WE COULD SEE A BRIEF PERIOD OF LOW END GALE FORCE WINDS UP NORTH. IN ADDITION...A COASTAL JET WILL LIKELY ENHANCE WINDS WITHIN 20 NM OF THE COAST. SEAS SHOULD BUMP UP A COUPLE FEET FROM THEIR CURRENT LEVELS FRIDAY...ESPECIALLY OVER THE CENTRAL OREGON WATERS. THIS WILL BE LARGELY IN RESPONSE TO THE GUSTY WINDS TONIGHT AND FRIDAY MORNING. /NEUMAN ANOTHER SYSTEM WILL BRING ANOTHER SURGE OF WINDS ON SAT...WITH ANOTHER LOW END GALE LOOKING LIKE A POSSIBILITY AT THIS POINT. STRONGER WESTERLY SWELL IS MODELED TO BUILD LATE SAT AND SUN. THE LATEST ENP GUIDANCE INDICATES THAT SEAS MAY BUILD INTO THE MID TEENS. YET ANOTHER FRONT ARRIVES LATE SUN INTO MON. PYLE && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 PM PDT FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PDT FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. GALE WARNING UNTIL 1 PM PDT FRIDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 AM TO 6 AM PDT FRIDAY. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 PM TO 6 PM PDT FRIDAY. && $$ MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA..
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
521 PM CDT FRI MAR 28 2014 .UPDATE... QUICK UPDATE TO ADD MENTION OF SEVERE THUNDERSTORM WATCH 39 WHICH WILL INCLUDE THE HOUSTON METRO AREA THIS EVENING. 38 && .PREV DISCUSSION... /ISSUED 328 PM CDT FRI MAR 28 2014/ DISCUSSION... AT 2 PM...A WEAK SURFACE LOW WAS LOCATED OVER CENTRAL TEXAS WITH A WARM FRONT TO THE NORTHEAST...A DRY LINE EXTENDING SOUTH TOWARD LAREDO AND A COLD FRONT EXTENDING WEST TOWARD THE BIG BEND. CONVECTION HAS FIRED IN CENTRAL TEXAS THIS AFTERNOON BUT COVERAGE REMAINS LIMITED. A SOUNDING FROM TEXAS A&M SHOWS A DECENT CAP BETWEEN 900-800 MB AND CONSIDERABLE DRY AIR AT 800 MB. LOOKS LIKE TEMPS WILL NEED TO WARM TO AROUND 86 DEGREES TO BREAK THE CAP. CONVECTION OVER CENTRAL TEXAS WILL CONTINUE TO PUSH EAST AND COULD HOLD TOGETHER AND MOVE ACROSS THE NORTHERN THIRD OF SE TX. THE RAP...TEXAS TECH WRF AND HRRR ALL ARE SUPPORTIVE OF CONVECTION MOVING ACROSS THE NORTH PART OF SE TX THIS EVENING BUT ALL THREE MODELS HAVE BEEN TOO AGGRESSIVE WITH RAIN CHANCES YESTERDAY AND AGAIN TODAY. WILL GO WITH LIKELY POPS OVER THE NORTH AND CHANCE POPS CENTRAL. WILL MENTION SOME STORMS SEVERE OVER THE NORTH. DENSE SEA FOG CONTINUES ALONG THE COAST. WEB CAMS AND SFC OBS CONT TO SHOW DENSE SEA FOG IMPINGING ON THE COAST AND OFFSHORE. WILL PROBABLY NEED A DENSE FOG ADVISORY TONIGHT FOR THE COASTAL COUNTIES THROUGH 06Z. THE RAP AND GFS ARE FASTER WITH A COLD FRONT TONIGHT AND IT APPEARS THAT THE FRONT WILL CLEAR THE COAST CLOSER TO 06Z THAN 12Z SAT. ONCE WINDS GO OFFSHORE...DRIER AIR WILL FILTER IN AND THE FOG WILL BEGIN TO DISSIPATE. HIGH PRESSURE WILL DOMINATE SATURDAY AND SUNDAY WITH SEASONAL TEMPS AND PLENTY OF SUNSHINE. CLOUDS WILL RETURN LATE SUNDAY NIGHT AND PERSIST THROUGH MUCH OF THE WEEK AHEAD AS HIGH PRESSURE DRIFTS EAST AND ONSHORE WINDS PREVAIL. FCST SOUNDINGS SHOW SATURATION BENEATH A CAP SO FEEL SOME STREAMER SHOWERS WILL BE POSSIBLE STARTING TUESDAY AND CONTINUING THROUGH FRIDAY. TEMPERATURES WILL ALSO BE MILDER NEXT WEEK WITH HIGHS NEAR 80 AND LOWS IN THE MID 60S. SOME DIFFERENCES WITH REGARD TO TIMING OF DISTURBANCES EMBEDDED IN THE UPPER FLOW SO WILL KEEP RAIN CHANCES ON THE LOW SIDE FOR NOW. GFS/ECMWF WITH THE TIMING OF THE NEXT COLD FRONT EITHER NEXT FRIDAY OR SATURDAY. 43 MARINE... DENSE SEA FOG TO BE THE MAIN ISSUE TONIGHT AS THE NEARSHORE DENSE DECK CREEPS BACK ONTO THE COAST IN THE COMING HOURS. ANOTHER DENSE SEA FOG ADVISORY LIKELY IN THE HOURS LEADING UP TO THE COLD FRONT THAT IS TIMED TO REACH THE SHORELINE AROUND MIDNIGHT...OR SHORTLY THEREAFTER. THIS FRONTAL PASSAGE WILL SCOUR OUT THE LOWER LEVEL MOISTURE AND RESIDENT FOG AND CLEAR SKIES THROUGH EARLY SATURDAY MORNING. LIGHT RAIN OR DRIZZLE WILL ACCOMPANY THIS FOG. POST-FRONTAL NORTHERLIES OVER THE FAR OFFSHORE WATERS WILL LIKELY INCREASE TO SCEC CRITERIA FOR A SHORT WHILE SATURDAY MORNING...GENERALLY 15 KNOTS OR LESS OVER THE BAYS AND NEARSHORE WATERS WITH OCCASIONAL 15- 20KT GUSTS OVER A SLIGHT CHOP. AS HIGH PRESSURE MOVES ACROSS FROM WEST-TO-EAST...LIGHT EASTERLIES WILL SLOWLY VEER SOUTHEASTERLY BY SUNDAY NIGHT. 31 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 52 78 49 76 53 / 60 10 10 10 0 HOUSTON (IAH) 58 79 52 77 55 / 40 10 10 10 0 GALVESTON (GLS) 64 74 59 73 60 / 20 10 10 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...DENSE FOG ADVISORY UNTIL 4 AM CDT SATURDAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT SHOULD EXERCISE CAUTION FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM... WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
328 PM CDT FRI MAR 28 2014 .DISCUSSION... AT 2 PM...A WEAK SURFACE LOW WAS LOCATED OVER CENTRAL TEXAS WITH A WARM FRONT TO THE NORTHEAST...A DRY LINE EXTENDING SOUTH TOWARD LAREDO AND A COLD FRONT EXTENDING WEST TOWARD THE BIG BEND. CONVECTION HAS FIRED IN CENTRAL TEXAS THIS AFTERNOON BUT COVERAGE REMAINS LIMITED. A SOUNDING FROM TEXAS A&M SHOWS A DECENT CAP BETWEEN 900-800 MB AND CONSIDERABLE DRY AIR AT 800 MB. LOOKS LIKE TEMPS WILL NEED TO WARM TO AROUND 86 DEGREES TO BREAK THE CAP. CONVECTION OVER CENTRAL TEXAS WILL CONTINUE TO PUSH EAST AND COULD HOLD TOGETHER AND MOVE ACROSS THE NORTHERN THIRD OF SE TX. THE RAP...TEXAS TECH WRF AND HRRR ALL ARE SUPPORTIVE OF CONVECTION MOVING ACROSS THE NORTH PART OF SE TX THIS EVENING BUT ALL THREE MODELS HAVE BEEN TOO AGGRESSIVE WITH RAIN CHANCES YESTERDAY AND AGAIN TODAY. WILL GO WITH LIKELY POPS OVER THE NORTH AND CHANCE POPS CENTRAL. WILL MENTION SOME STORMS SEVERE OVER THE NORTH. DENSE SEA FOG CONTINUES ALONG THE COAST. WEB CAMS AND SFC OBS CONT TO SHOW DENSE SEA FOG IMPINGING ON THE COAST AND OFFSHORE. WILL PROBABLY NEED A DENSE FOG ADVISORY TONIGHT FOR THE COASTAL COUNTIES THROUGH 06Z. THE RAP AND GFS ARE FASTER WITH A COLD FRONT TONIGHT AND IT APPEARS THAT THE FRONT WILL CLEAR THE COAST CLOSER TO 06Z THAN 12Z SAT. ONCE WINDS GO OFFSHORE...DRIER AIR WILL FILTER IN AND THE FOG WILL BEGIN TO DISSIPATE. HIGH PRESSURE WILL DOMINATE SATURDAY AND SUNDAY WITH SEASONAL TEMPS AND PLENTY OF SUNSHINE. CLOUDS WILL RETURN LATE SUNDAY NIGHT AND PERSIST THROUGH MUCH OF THE WEEK AHEAD AS HIGH PRESSURE DRIFTS EAST AND ONSHORE WINDS PREVAIL. FCST SOUNDINGS SHOW SATURATION BENEATH A CAP SO FEEL SOME STREAMER SHOWERS WILL BE POSSIBLE STARTING TUESDAY AND CONTINUING THROUGH FRIDAY. TEMPERATURES WILL ALSO BE MILDER NEXT WEEK WITH HIGHS NEAR 80 AND LOWS IN THE MID 60S. SOME DIFFERENCES WITH REGARD TO TIMING OF DISTURBANCES EMBEDDED IN THE UPPER FLOW SO WILL KEEP RAIN CHANCES ON THE LOW SIDE FOR NOW. GFS/ECMWF WITH THE TIMING OF THE NEXT COLD FRONT EITHER NEXT FRIDAY OR SATURDAY. 43 && .MARINE... DENSE SEA FOG TO BE THE MAIN ISSUE TONIGHT AS THE NEARSHORE DENSE DECK CREEPS BACK ONTO THE COAST IN THE COMING HOURS. ANOTHER DENSE SEA FOG ADVISORY LIKELY IN THE HOURS LEADING UP TO THE COLD FRONT THAT IS TIMED TO REACH THE SHORELINE AROUND MIDNIGHT...OR SHORTLY THEREAFTER. THIS FRONTAL PASSAGE WILL SCOUR OUT THE LOWER LEVEL MOISTURE AND RESIDENT FOG AND CLEAR SKIES THROUGH EARLY SATURDAY MORNING. LIGHT RAIN OR DRIZZLE WILL ACCOMPANY THIS FOG. POST-FRONTAL NORTHERLIES OVER THE FAR OFFSHORE WATERS WILL LIKELY INCREASE TO SCEC CRITERIA FOR A SHORT WHILE SATURDAY MORNING...GENERALLY 15 KNOTS OR LESS OVER THE BAYS AND NEARSHORE WATERS WITH OCCASIONAL 15- 20KT GUSTS OVER A SLIGHT CHOP. AS HIGH PRESSURE MOVES ACROSS FROM WEST-TO-EAST...LIGHT EASTERLIES WILL SLOWLY VEER SOUTHEASTERLY BY SUNDAY NIGHT. 31 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 52 78 49 76 53 / 60 10 10 10 0 HOUSTON (IAH) 58 79 52 77 55 / 40 10 10 10 0 GALVESTON (GLS) 64 74 59 73 60 / 20 10 10 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1204 AM CDT FRI MAR 28 2014 .AVIATION... /06Z TAFS/ CONCERNS...IFR CONDITIONS OVERNIGHT AND THUNDERSTORMS FRIDAY AFTERNOON. A COLD FRONT ARRIVES LATER ON FRIDAY WITH MVFR CIGS RETURNING BEHIND THE FRONT. MVFR AND IFR CEILINGS ARE SPREADING WEST ACROSS NORTH AND CENTRAL TEXAS. EXPECT ALL TAF SITES TO BE UNDER IFR CIGS BY 07Z TONIGHT. IN ADDITION...AREAS OF FOG ARE POSSIBLE WITH VISIBILITIES 2-5SM. CONDITIONS WILL IMPROVE LATE FRIDAY MORNING AS A DRYLINE AND COLD FRONT ENCROACH ALONG THE I-35 CORRIDOR. THE WINDS IN THE METROPLEX WILL BEGIN TO TURN TOWARD THE WEST IN THE AFTERNOON HOURS AND THEN THE FRONT ARRIVES AROUND 22Z. SOUTH WINDS WILL PREVAIL AT KACT WITH LIGHT WINDS IMMEDIATELY AHEAD OF THE FRONT IN THE LATE AFTERNOON HOURS WITH FROPA AROUND 29/00Z. KACT COULD SEE SOME SHOWERS AND POSSIBLY ISOLATED THUNDER BY MID TO LATE FRIDAY MORNING BUT A STRONG SHORTWAVE WILL BRING A CHANCE FOR THUNDERSTORMS TO ALL THE AIRPORTS DURING THE AFTERNOON HOURS. SOME OF THE STORMS COULD BE SEVERE. THE THREAT FOR THUNDER WILL END IN THE EARLY EVENING HOURS. 82/JLD && .UPDATE... RAN A QUICK UPDATE TO INCREASE POPS FOR THUNDERSTORM CHANCES ACROSS THE CWA TOMORROW. WATER VAPOR SATELLITE IMAGERY WAS TRACKING A COMPACT SHORTWAVE TROUGH OVER SOUTHERN CALIFORNIA...MOVING EAST TOWARDS ARIZONA AND NEW MEXICO. THIS TROUGH IS EXPECTED TO SPREAD LARGE SCALE FORCING FOR ASCENT OVER NORTH TX STARTING AROUND 18Z. CONVECTION THIS EVENING ACROSS THE CWA WAS LIMITED TO COLLIN COUNTY AND AREAS NORTHEAST...SO ANY REMNANT OUTFLOW BOUNDARIES ARE EXPECTED TO REMAIN IN PLACE ACROSS THE NORTHEASTERN CWA...IF THEY DONT JUST DISSIPATE ALL TOGETHER BY TOMORROW MORNING. THE DRYLINE MADE IT AS FAR EAST AS A GAINESVILLE TO FORT WORTH TO HAMILTON LINE THIS AFTERNOON...AND WAS OBSERVED TO BE RETREATING BACK TO THE WEST AT THE TIME OF THIS DISCUSSION. A COLD FRONT WAS OBSERVED ACROSS EAST CENTRAL OKLAHOMA...STRETCHING BACK WEST TO THE TEXAS PANHANDLE. THIS BOUNDARY WAS MOVING SLOWLY SOUTH THIS EVENING...AT AROUND 10 MPH. THE 00Z NAM AND RAP MODELS WERE CONSISTENT IN SHOWING A LOW-LEVEL (850 MB) THETA-E RIDGE MOVING NORTHEAST ACROSS THE CWA FROM AROUND THE MILLS/LAMPASAS COUNTY AREA TOMORROW MORNING. THIS THETA-E RIDGE WAS MORE OR LESS CONSISTENT WITH THE ZONE OF BEST Q-VECTOR CONVERGENCE OR POSITIVE PRESSURE ADVECTION ON THE 1.5 PVU SURFACE. AS A RESULT...THINK THAT THE THETA-E RIDGE IS LIKELY TO BE REAL AND ASSOCIATED WITH LARGE SCALE FORCING FOR ASCENT BROUGHT ON BY THE APPROACHING SHORTWAVE TROUGH. THIS THETA-E RIDGE IS EXPECTED TO EXPAND IN AREAL COVERAGE WHILE MOVING NORTHEAST ACROSS THE SOUTHEASTERN HALF OF THE CWA TOMORROW MORNING. NON-CONVECTION ALLOWING OPERATIONAL GUIDANCE CONSISTENTLY HAS ITS CONVECTIVE PARAMETERIZATION SCHEMES TRIGGERED IN THIS ZONE OF RICH THETA-E AIR...SO CONFIDENCE IN A MORNING ROUND OF LARGELY UNORGANIZED THUNDERSTORM ACTIVITY HAS INCREASED. WENT AHEAD AND BUMPED UP POPS TO 30 PERCENT FOR LOCATIONS ALONG AND SOUTH OF A LAMPASAS TO HILLSBORO TO PALESTINE LINE TOMORROW MORNING AS A RESULT. SEVERE WEATHER IS POSSIBLE WITH THIS ACTIVITY...BUT SHOULD REMAIN ELEVATED IN NATURE LEAVING ONLY A MARGINAL HAIL THREAT DURING THE MORNING HOURS OF THE DAY. FOR THE AFTERNOON...THE MORNING CONVECTION...DEPENDING ON HOW STRONG IT IS...AND HOW LARGE ITS AREAL COVERAGE IS...MAY IMPEDE AFTERNOON THUNDERSTORM INITIATION. AFTERNOON THUNDERSTORM INITIATION IS MOST LIKELY ALONG THE DRYLINE...AND THEN AGAIN ALONG THE COLD FRONT. INITIATION IS DEPENDENT UPON GOOD SOLAR INSOLATION REMOVING A LOW-LEVEL INVERSION AND MIXING OUT LOW-LEVEL MORNING STRATUS...ALLOWING FOR SURFACE BASED STORMS. MESOSCALE FORCING FOR ASCENT ASSOCIATED WITH THE COLD FRONT AND DRYLINE WILL CERTAINLY SUPPORT STRONG LIFT NEAR THESE BOUNDARIES...HOWEVER FORECAST SOUNDINGS INDICATE TOO MUCH CONVECTIVE INHIBITION TO BE OVERCOME BY LIFT ALONE. ASSUMING MORNING CONVECTION EITHER DOES NOT PAN OUT...OR THAT THE CLOUDS CLEAR OUT SUFFICIENTLY TO ALLOW FOR A FEW HOURS OF HEATING...THUNDERSTORM INITIATION ALONG THESE BOUNDARIES CAN BE EXPECTED TO OCCUR AROUND 21Z OR 4 PM CDT. AT 21Z...THE DRYLINE IS EXPECTED TO BE LOCATED JUST WEST OF THE INTERSTATE 35 CORRIDOR WITH THE COLD FRONT DROPPING SOUTH TO A SHERMAN TO FORT WORTH TO CISCO LINE. THIS LEAVES THE TRIPLE POINT NEAR THE DFW AREA...WHERE THE STRONGEST MESOSCALE FORCING FOR ASCENT SHOULD OCCUR. WENT AHEAD AND BUMPED POPS UP TO 30 PERCENT NEAR THESE BOUNDARIES...INCREASING TO 50 PERCENT TO THE EAST AND SOUTHEAST. WITH THE FAST MOVING NATURE OF THE SHORTWAVE TROUGH AND ITS ENHANCED MID-UPPER LEVEL WIND SPEEDS...ANY INITIATED STORMS WOULD TEND TO PULL AWAY FROM THESE BOUNDARIES SOMEWHAT QUICKLY. HIGH RESOLUTION MODELS INDICATE THE POTENTIAL FOR AROUND 2000 J/KG OF SURFACE BASED CAPE WITH A DEEP LAYER BULK SHEAR MAGNITUDE OF AROUND 50 KTS...A BASIC PARAMETER SPACE OVERLAP FAVORING AN ORGANIZED STORM MODE WITH SUPERCELLS...OR CLUSTERS OF STORMS WITH EMBEDDED SUPERCELL STRUCTURES. WHETHER THIS MUCH CAPE CAN BE REALIZED OR NOT DEPENDS LARGELY ON THE FACTORS DISCUSSED ABOVE...AND WILL BE LARGELY UNKNOWN UNTIL WE SEE HOW MUCH PRECIPITATION EXISTS TOMORROW MORNING. IF THE CAPE IS REALIZED...THE PRIMARY SEVERE WEATHER HAZARDS SHOULD BE LARGE HAIL AND DAMAGING WINDS. A CONDITIONAL TORNADO THREAT IS DEPENDENT UPON INDIVIDUAL STORMS INTERACTING WITH ANY REMNANT BOUNDARIES TOMORROW AFTERNOON. OVERALL THE TORNADO THREAT DOES NOT LOOK HIGH FROM THE SYNOPTIC ENVIRONMENT...BUT WE WILL SEE HOW EVERYTHING EVOLVES AFTER TOMORROW MORNING. THE THREAT FOR TORNADOES LOOKS LOW FOR NOW AT LEAST. STORMS SHOULD MOVE EAST OF THE CWA QUICKLY AFTER SUNSET AS THE SHORTWAVE TROUGH PUSHES EAST...AND THE COLD FRONT BEGINS TO MOVE QUICKLY ACROSS THE CWA. CAVANAUGH && .PREV DISCUSSION... /ISSUED 311 PM CDT THU MAR 27 2014/ AN UPPER LEVEL TROUGH CAN BE SEEN ON THE LATEST WATER VAPOR LOOP LIFTING NORTHEAST FROM THE CENTRAL PLAINS TOWARDS THE GREAT LAKES. A DEEP SURFACE CYCLONE IS FOLLOWING ALONG A SIMILAR PATH BENEATH THE UPPER TROUGH...AND THE RESULTING FLOW IS SENDING A COLD FRONT SOUTHWARD TOWARDS NORTH TEXAS. BOTH THE FRONT AND FORCING FOR ASCENT ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL REMAIN WELL NORTH OF NORTH TEXAS THIS EVENING. ANY SURFACE FOCUS FOR CONVECTION WILL BE ASSOCIATED WITH A DRYLINE...WHICH WAS ENCROACHING ON THE I-35 CORRIDOR THIS AFTERNOON. ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH SUNSET THIS EVENING ALONG THE DRYLINE...WITH THE BETTER CHANCES FOR CONVECTION WELL EAST OF THE DRYLINE WHERE MOISTURE LEVELS ARE HIGHER AND WEAK ASCENT FROM THE SOUTHERN EXTENT OF THE PLAINS SYSTEM WILL RESIDE. THOUGH COVERAGE WILL BE LOW DUE TO VEERING SURFACE WINDS AND A LINGERING CAP OVERHEAD...CAPE OF 1500 TO 2000 J/KG ENSURES THAT ANY STORMS THAT DEVELOP COULD BECOME STRONG TO POSSIBLY SEVERE WITH HAIL AND DAMAGING WINDS. WEST OF THE DRYLINE...HIGH FIRE DANGER WILL CONTINUE FOR A FEW MORE HOURS BEFORE TEMPERATURES FALL AND WINDS DECREASE AFTER SUNSET. THE FRONT WILL CROSS THE RED RIVER TONIGHT AND SAG SLOWLY SOUTH TO NEAR THE I-20 CORRIDOR AROUND NOON FRIDAY...WITH THE DRYLINE EXTENDING SOUTHWEST FROM THE FRONT ACROSS THE SOUTHWESTERN COUNTIES BY NOON FRIDAY AS WELL. THESE BOUNDARIES SHOULD BOTH SERVE AS A FOCUS FOR CONVECTION AS A SECOND UPPER LEVEL TROUGH PASSES OVERHEAD. THIS FEATURE IS CURRENTLY OVER SOUTHERN CALIFORNIA AND WILL MOVE QUICKLY EASTWARD INTO THE DESERT SOUTHWEST TONIGHT...THEN ACROSS TEXAS TOMORROW. SUFFICIENT INSTABILITY WILL BE PRESENT ONCE AGAIN WITH SLIGHTLY BETTER UPPER LEVEL SUPPORT IN PLACE...AND ANY STORM THAT DEVELOPS MAY BECOME STRONG TO POSSIBLE SEVERE. THE BEST CHANCES WILL AGAIN BE OVER THE EAST AND SOUTHEAST COUNTIES WHERE THE HIGHEST MOISTURE LEVELS / 1 INCH OR GREATER PWATS / WILL BE LOCATED. THE EXTENT OF THE CONVECTION IS SOMEWHAT OF A QUESTION MARK...WITH NAM12 BEING AGGRESSIVE AND THE GFS MUCH MORE PASSIVE AND FARTHER EAST WITH THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. HIGHER COVERAGE THAN TODAY WOULD MAKE SENSE BASED ON THE ADDITION OF THE COLD FRONT AND THE CLOSER PROXIMITY OF THE UPPER LEVEL TROUGH. THIS MAY BE NEGATED THOUGH IF THE UPPER LEVEL FEATURE MOVES ACROSS PRIOR TO PEAK HEATING...LEAVING US IN THE SUBSIDENT REGION BY AFTERNOON. WE WILL MAINTAIN THE 40 POPS IN THE EAST ZONES FOR FRIDAY...LOWERING TO 20 IN THE CENTRAL ZONES INCLUDING THE DALLAS-FORT WORTH METROPLEX FOR NOW. THIS SYSTEM WILL MOVE EAST OF THE REGION TOMORROW NIGHT...BRINGING UPPER RIDGING...WIDESPREAD SUBSIDENCE AND NICE WEATHER TO NORTH TEXAS FOR THE WEEKEND. PLENTIFUL SUN WILL ALLOW HIGH TEMPERATURES TO CLIMB INTO THE MID AND UPPER 70S... WITH MOSTLY CLEAR SKIES ALLOWING NIGHT TIME LOWS TO DROP INTO THE MID AND UPPER 40S. A WEAK DISTURBANCE WILL MOVE ACROSS THE SOUTHERN PLAINS ON MONDAY...BRINGING AN INCREASE IN CLOUDS BUT LITTLE IN THE WAY OF PRECIPITATION. MODELS CONTINUE TO ADVERTISE A STRONGER UPPER TROUGH DEEPENING OVER THE 4-CORNERS REGION WEDNESDAY...WHICH SHOULD BRING A DECENT CHANCE OF SHOWERS AND THUNDERSTORMS DURING THE MIDDLE PART OF NEXT WEEK. 30 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 57 79 48 76 49 / 20 30 30 0 0 WACO, TX 59 82 49 77 48 / 20 50 50 0 0 PARIS, TX 60 76 45 73 45 / 40 20 20 0 0 DENTON, TX 53 77 45 75 44 / 20 20 20 0 0 MCKINNEY, TX 57 78 46 75 45 / 20 30 30 0 0 DALLAS, TX 59 79 49 76 50 / 20 30 30 0 0 TERRELL, TX 60 80 47 75 46 / 30 40 40 0 0 CORSICANA, TX 62 81 49 76 47 / 30 50 50 0 0 TEMPLE, TX 60 82 50 78 48 / 20 50 50 0 0 MINERAL WELLS, TX 51 80 45 77 44 / 10 10 10 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 82/69
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
746 AM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT WILL ENTER OUR REGION BY TONIGHT. ANOTHER AREA OF LOW PRESSURE WILL RIDE EASTWARD ALONG THE STALLED FRONT FROM THE MIDDLE MISSISSIPPI VALLEY ON SATURDAY. THIS FRONT WILL EXIT THE COAST SATURDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM EDT FRIDAY... WINDS EARLY THIS MORNING WILL STAY GUSTY OVER THE HIGHER RIDGES AND THROUGH SOME GAPS ON THE NORTH SIDE OF TWO MOUNTAINS. NOT GETTING ANY REPORTS OF WIND DAMAGE/POWER OUTAGES...BUT HAD ONE SPOTTER REPORT GUSTS OVER 50 MPH PER WIND INSTRUMENT. GIVEN LACK OF COVERAGE OVERALL AND WITH SFC/LOW LVL FLOW STARTING TO VEER MORE TOWARD SOUTH TO SSW...AN ADVISORY IS NOT NEEDED. OUR TYPICAL WINDIEST PLACES IN THIS PATTERN HAVE ONLY GUSTED TO 42 MPH IN TAZEWELL COUNTY. AN SPS WAS ISSUED TO COVER THE HIGHER RIDGES UNTIL THE LOW LVL JET LIFTS NORTH. RAIN SHOWERS FORMING ALONG WEAK THETA-E RIDGE AHEAD OF THE MAIN SYSTEM OVER THE NEW RIVER VALLEY THIS MORNING AND BLUE RIDGE. MAINLY WILL SEE ISOLATED/SCATTERED COVERAGE EARLY BEFORE MAIN LINE BATCH MOVES IN AFTER 12Z. STILL NOT SEEING WIDESPREAD COVERAGE BUT ENOUGH TO WARRANT LIKELY TO CATEGORICAL POPS OVER THE WEST LATER THIS MORNING...AS THETA-E RIDGE SHIFTS FROM FAR SW VA INTO THE NRN VA AREA. THE LATEST HRRR IS HANDLING THIS PRETTY WELL IN REGARDS TO PRECIP AND SHOWS POTENTIAL BREAK IN THE ACTION MID MORNING...AS ONE AREA OF SHOWERS MOVES INTO THE SHENANDOAH VALLEY...AND THE NEXT AREA SLIDING NORTHEAST TOWARD THE NC MTNS/FAR SW VA AGAIN BY MIDDAY. WILL LEAN THIS MORNING POPS THIS WAY...BLENDING TOWARD A GFS/SREF/ECMWF SOLUTION BY AFTERNOON. GFS DRYING IT FASTER WHICH AGREES WITH THE 00Z WRF/HRRR TO SOME EXTENT AS WELL AS THE 00Z NAM. THIS AFTERNOON WILL HAVE CHANCE POPS ACROSS THE NRN CWA TO LIKELY IN THE SRN TIER FROM THE NC MTNS TO SOUTHSIDE VA...WITH POTENTIAL FOR SLIGHT CHANCE TO NO CHANCE RAIN AROUND 00Z NORTH OF INTERSTATE 64. TEMPS WILL BE MILD TODAY BUT CLOUDS/RAIN SHOWERS WILL HELP TO KEEP THEM COOLER THAN NORMAL. MAV/MET BLEND SEEMS TO HANDLE THIS BEST. LOOK FOR HIGHS FROM THE LOWER TO MID 50S NORTH CAROLINA MTNS/SRN BLUE RIDGE OF VA TO LOWER TO MID 60S ACROSS THE MTN EMPIRE AS WELL AS THE PIEDMONTS AND ROANOKE VALLEY. TONIGHT...A DRYING OUT SOME ALOFT WITH LOW LVL MOISTURE STAYING CLOSE AT HAND...SO WILL SEE SOME LIGHT RAIN EARLY IN THE SOUTH WITH MAIN WAVE OF LOW PRESSURE TRACKING TOWARD MID TN/SRN KY BY LATE TONIGHT. THIS WILL BUCKLE THE FRONT NORTH AGAIN WITH CATEGORICAL RAIN RETURNING FROM SOUTH TO NORTH OVERNIGHT. MILD LOWS IN THE 40S...LOWER 50S. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AN UPPER LEVEL TROUGH WILL TRACK EAST OVER THE MID WEST GENERATING A SURFACE LOW THAT WILL TRACK ALONG THE FRONTAL BOUNDARY SATURDAY MORNING. THE UPPER LEVEL TROUGH WILL START TO CLOSE OFF SATURDAY AFTERNOON...WITH A NEW SURFACE LOW DEVELOPING ALONG THE LEE SIDE OF THE SOUTHERN APPALACHIANS. THIS SURFACE LOW IS EXPECTED TO TRACK ACROSS THE CAROLINA-VIRGINIA PIEDMONT SATURDAY AFTERNOON/EVENING...THEN OFF THE DELMARVA COAST SATURDAY NIGHT. THE GFS HAS THE CLOSED UPPER LOW OVER WEST VIRGINIA SATURDAY EVENING...TRACKING OVER THE FORECAST AREA AND ACROSS SOUTHERN VIRGINIA SUNDAY MORNING. THE NAM/ECM HAS THE CLOSED LOW SLIGHTLY FARTHER TO THE SOUTH...TRACKING FROM SOUTHWESTERN VIRGINIA SATURDAY EVENING...ACROSS NORTH CAROLINA THROUGH THE MORNING...THEN OFF THE NORTH CAROLINA COAST BY SUNDAY EVENING. WITH AMPLE MOISTURE AND GOOD JET DYNAMICS...MOST OF SATURDAY WILL BE WET. THE GOOD NEWS IS THAT IT WILL FALL AS RAIN AND NOT SNOW. AS THE SECOND LOW TAKES SHAPE AND RACES NORTHEAST OF THE AREA SATURDAY EVENING...A DRY SLOT WILL TEMPORARILY END THE RAIN SHOWERS. RAIN SHOWERS RE-ENTERS THE AREA AS THE UPPER LEVEL LOW TRACKS EAST THROUGH SUNDAY MORNING. TEMPERATURES SHOULD REMAIN WARM ENOUGH ON THE FRONT END OF THIS LOW TO KEEP P-TYPE AS LIQUID. ON THE BACK SIDE...COLD AIR AND WRAP-AROUND MOISTURE MAY CHANGE RAIN OVER TO SNOW/GRAUPEL FOR THE MOUNTAINS...POSSIBLY EAST OF THE BLUE RIDGE SUNDAY MORNING. CAN NOT RULE OUT A STRIKE OR TWO OF LIGHTNING AS THE UPPER LOW MOVES OVERHEAD...BUT WILL LEAVE OUT OF THE WEATHER GRIDS WITH IT TRACKING OVER IN THE MORNING. BY SUNDAY EVENING...PRECIPITATION WILL BE EAST OF THE AREA...THEN THE WINDS WILL PICK UP FROM THE NORTH-NORTHWEST. HIGH PRESSURE BUILDS IN QUICKLY TO CONFINE STRONGEST WINDS TO A 12 HOUR PERIOD SUNDAY...WEAKENING THROUGH THE NIGHT. RAINFALL AMOUNTS SATURDAY INTO SATURDAY EVENING WILL RANGE FROM A THIRD TO THREE-QUARTERS OF AN INCH. IF TODAYS RAIN IS SIGNIFICANT ENOUGH AND MODELS MAINTAIN SIMILAR QPF TOTALS FOR SATURDAY...A FLOOD WATCH MAY BE ISSUED. CONFIDENCE IS LOW AT THIS TIME. CONSIDER WINTERS GRIP ON THE AREA THIS YEAR...HESITANT TO GO WITH A LITTLE IF ANY SNOWFALL STATEMENT. BOTH THE NAM AND ECM PAINT A DUSTING TO AN INCH ACROSS THE MOUNTAINS AND INTO THE FOOTHILLS FROM MIDNIGHT TO NOON SUNDAY. THE GFS IS SIMILAR BUT WITH A 3-4 INCH BULLEYE CENTERED ON SNOWSHOE WV. WITH THE UPPER LEVEL LOW COMING OVER DURING THE MORNING...CHANCES ARE GOOD FOR SNOWFALL ESPECIALLY ACROSS THE WEST. IF THE UPPER LOW IS SLOW TO MOVE ACROSS THE AREA...THEN WE CAN NOT RULE OUT A COMMON INCH OR TWO ACROSS THE MOUNTAINS...SLIGHTLY HIGHER AMOUNTS ALONG HIGHER ELEVATIONS. HOWEVER...MODELS ZIP THE UPPER LOW ACROSS THE FORECAST AREA...WITH A NARROW BAND OF MOISTURE BEHIND IT...TO KEEP TOTALS UNDER AN INCH. THERE IS A WIDE RANGE IN GUIDANCE TEMPERATURES FOR SATURDAY. FOR EXAMPLE...GFSMOS FOR ROANOKE IS 66F WHILE THE NAM IS FORECASTING 50F. THE ECMMOS IS 61F. WITH RAIN EXPECTED FOR MUCH OF THE DAY...KEPT TEMPERATURES COOL...OBVIOUSLY BETWEEN GUIDANCE...SIMILAR TO PREVIOUS FORECAST. WITH AN EARLY EXIT OF THE CLOSED LOW...TEMPERATURES WILL REBOUND QUICKLY SUNDAY AFTERNOON. GUIDANCE WAS A LITTLE MORE HELPFUL WILL FORECASTED HIGHS AROUND 5F COLDER THAN NORMAL. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM EST THURSDAY... LOOKS LIKE MARCH WILL GO OUT LIKE A LAMB AS THE FIRST HALF OF NEXT WEEK LOOKS DRY. 1024 MB SURFACE HIGH IS PROGGED TO PASS OVHD MONDAY...FOLLOWED BY A DRY FRONTAL PASSAGE TUESDAY. ASIDE FOR SOME SCATTERED CLOUDS AND A WIND SHIFT TUESDAY...NO SENSIBLE WEATHER CHALLENGES ANTICIPATED FOR MONDAY THROUGH WEDNESDAY. THAT SAID...NOT QUITE AS PRISTINE FROM THE ROCKIES INTO THE UPPER MID WEST WHERE THE STORM TRACK WILL NOT BE AS FORGIVING. THIS MID CONUS STORMINESS WILL EVENTUALLY WORK ITS WAY TOWARD THE EAST COAST BY THE END OF THE WEEK WITH THE BAROCLINIC ZONE SLIDING BACK OUR WAY WITH THE THREAT FOR UNSETTLED WEATHER FROM THURSDAY INTO NEXT WEEKEND. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 740 AM EDT FRIDAY... SCATTERED SHOWERS WILL AFFEC THE AREA THIS MORNING...BECOMING MORE NUMEROUS IN THE MOUNTAINS...PERHAPS ARRIVING AT LYH BY MIDDAY. CIGS WILL FLUCTUATE BETWEEN LOW END VFR TO HIGH END MVFR THIS MORNING THRU THE AFTERNOON. STILL SOME WINDS JUST ABOVE THE INVERSION OUT OF THE SW GUSTING TO 40 KNOTS...SO KEPT LLWS IN EARLY BEFORE SHOWERS. THERE SHOULD BE A BREAK IN THE COVERAGE THIS AFTERNOON...WITH ACTIVITY PICKING UP AGAIN TONIGHT IN THE SOUTH SPREADING NWD OVERNIGHT. OVERALL SHOULD SEE SOME GUSTY WINDS MIX DOWN IN THE ROA/LYH/DAN AREA THIS AFTERNOON WITH WINDS WEAKENING THIS EVENING. MODELS ARE LOWERING CIGS/VSBYS TO MVFR OR IFR OVERNIGHT WITH RAIN MOVING BACK IN. THE LOW MOVES ACROSS SATURDAY WITH MOST SITES REMAIN SUB VFR WITH RAIN SHOWERS. AN ISOLATED THUNDERSTORM WILL BE POSSIBLE OVER LYH/DAN SAT AFTERNOON. WINDS PICK UP BEHIND THE LOW SAT NIGHT- SUNDAY MORNING...BEFORE HIGH PRESSURE WORKS IN FOR MONDAY. LOOK FOR IMPROVING CIGS/VSBYS SAT NIGHT IN THE EAST AND BY SUNDAY AFTERNOON IN THE WEST. DRY WEATHER AND VFR CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. && .EQUIPMENT... AS OF 135 AM EDT THURSDAY... ACCESS TO DATA ON OUR WEB PAGE...WWW.ERH.NOAA.GOV/RNK/...REMAINS LIMITED DUE TO REGIONAL SERVER ISSUES. THERE IS NO ESTIMATE AT THIS TIME FOR WHEN IT WILL BE REPAIRED. OUR NEW...BUT UNFINISHED SITE...WWW.WEATHER.GOV/RNK/ IS OPERATING PROPERLY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...WP SHORT TERM...RCS LONG TERM...PM AVIATION...DS/JC/WP EQUIPMENT...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
436 AM EDT FRI MAR 28 2014 .SYNOPSIS... A COLD FRONT WILL ENTER OUR REGION BY TONIGHT. ANOTHER AREA OF LOW PRESSURE WILL RIDE EASTWARD ALONG THE STALLED FRONT FROM THE MIDDLE MISSISSIPPI VALLEY ON SATURDAY. THIS FRONT WILL EXIT THE COAST SATURDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 330 AM EDT FRIDAY... WINDS EARLY THIS MORNING WILL STAY GUSTY OVER THE HIGHER RIDGES AND THROUGH SOME GAPS ON THE NORTH SIDE OF TWO MOUNTAINS. NOT GETTING ANY REPORTS OF WIND DAMAGE/POWER OUTAGES...BUT HAD ONE SPOTTER REPORT GUSTS OVER 50 MPH PER WIND INSTRUMENT. GIVEN LACK OF COVERAGE OVERALL AND WITH SFC/LOW LVL FLOW STARTING TO VEER MORE TOWARD SOUTH TO SSW...AN ADVISORY IS NOT NEEDED. OUR TYPICAL WINDIEST PLACES IN THIS PATTERN HAVE ONLY GUSTED TO 42 MPH IN TAZEWELL COUNTY. AN SPS WAS ISSUED TO COVER THE HIGHER RIDGES UNTIL THE LOW LVL JET LIFTS NORTH. RAIN SHOWERS FORMING ALONG WEAK THETA-E RIDGE AHEAD OF THE MAIN SYSTEM OVER THE NEW RIVER VALLEY THIS MORNING AND BLUE RIDGE. MAINLY WILL SEE ISOLATED/SCATTERED COVERAGE EARLY BEFORE MAIN LINE BATCH MOVES IN AFTER 12Z. STILL NOT SEEING WIDESPREAD COVERAGE BUT ENOUGH TO WARRANT LIKELY TO CATEGORICAL POPS OVER THE WEST LATER THIS MORNING...AS THETA-E RIDGE SHIFTS FROM FAR SW VA INTO THE NRN VA AREA. THE LATEST HRRR IS HANDLING THIS PRETTY WELL IN REGARDS TO PRECIP AND SHOWS POTENTIAL BREAK IN THE ACTION MID MORNING...AS ONE AREA OF SHOWERS MOVES INTO THE SHENANDOAH VALLEY...AND THE NEXT AREA SLIDING NORTHEAST TOWARD THE NC MTNS/FAR SW VA AGAIN BY MIDDAY. WILL LEAN THIS MORNING POPS THIS WAY...BLENDING TOWARD A GFS/SREF/ECMWF SOLUTION BY AFTERNOON. GFS DRYING IT FASTER WHICH AGREES WITH THE 00Z WRF/HRRR TO SOME EXTENT AS WELL AS THE 00Z NAM. THIS AFTERNOON WILL HAVE CHANCE POPS ACROSS THE NRN CWA TO LIKELY IN THE SRN TIER FROM THE NC MTNS TO SOUTHSIDE VA...WITH POTENTIAL FOR SLIGHT CHANCE TO NO CHANCE RAIN AROUND 00Z NORTH OF INTERSTATE 64. TEMPS WILL BE MILD TODAY BUT CLOUDS/RAIN SHOWERS WILL HELP TO KEEP THEM COOLER THAN NORMAL. MAV/MET BLEND SEEMS TO HANDLE THIS BEST. LOOK FOR HIGHS FROM THE LOWER TO MID 50S NORTH CAROLINA MTNS/SRN BLUE RIDGE OF VA TO LOWER TO MID 60S ACROSS THE MTN EMPIRE AS WELL AS THE PIEDMONTS AND ROANOKE VALLEY. TONIGHT...A DRYING OUT SOME ALOFT WITH LOW LVL MOISTURE STAYING CLOSE AT HAND...SO WILL SEE SOME LIGHT RAIN EARLY IN THE SOUTH WITH MAIN WAVE OF LOW PRESSURE TRACKING TOWARD MID TN/SRN KY BY LATE TONIGHT. THIS WILL BUCKLE THE FRONT NORTH AGAIN WITH CATEGORICAL RAIN RETURNING FROM SOUTH TO NORTH OVERNIGHT. MILD LOWS IN THE 40S...LOWER 50S. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AN UPPER LEVEL TROUGH WILL TRACK EAST OVER THE MID WEST GENERATING A SURFACE LOW THAT WILL TRACK ALONG THE FRONTAL BOUNDARY SATURDAY MORNING. THE UPPER LEVEL TROUGH WILL START TO CLOSE OFF SATURDAY AFTERNOON...WITH A NEW SURFACE LOW DEVELOPING ALONG THE LEE SIDE OF THE SOUTHERN APPALACHIANS. THIS SURFACE LOW IS EXPECTED TO TRACK ACROSS THE CAROLINA-VIRGINIA PIEDMONT SATURDAY AFTERNOON/EVENING...THEN OFF THE DELMARVA COAST SATURDAY NIGHT. THE GFS HAS THE CLOSED UPPER LOW OVER WEST VIRGINIA SATURDAY EVENING...TRACKING OVER THE FORECAST AREA AND ACROSS SOUTHERN VIRGINIA SUNDAY MORNING. THE NAM/ECM HAS THE CLOSED LOW SLIGHTLY FARTHER TO THE SOUTH...TRACKING FROM SOUTHWESTERN VIRGINIA SATURDAY EVENING...ACROSS NORTH CAROLINA THROUGH THE MORNING...THEN OFF THE NORTH CAROLINA COAST BY SUNDAY EVENING. WITH AMPLE MOISTURE AND GOOD JET DYNAMICS...MOST OF SATURDAY WILL BE WET. THE GOOD NEWS IS THAT IT WILL FALL AS RAIN AND NOT SNOW. AS THE SECOND LOW TAKES SHAPE AND RACES NORTHEAST OF THE AREA SATURDAY EVENING...A DRY SLOT WILL TEMPORARILY END THE RAIN SHOWERS. RAIN SHOWERS RE-ENTERS THE AREA AS THE UPPER LEVEL LOW TRACKS EAST THROUGH SUNDAY MORNING. TEMPERATURES SHOULD REMAIN WARM ENOUGH ON THE FRONT END OF THIS LOW TO KEEP P-TYPE AS LIQUID. ON THE BACK SIDE...COLD AIR AND WRAP-AROUND MOISTURE MAY CHANGE RAIN OVER TO SNOW/GRAUPEL FOR THE MOUNTAINS...POSSIBLY EAST OF THE BLUE RIDGE SUNDAY MORNING. CAN NOT RULE OUT A STRIKE OR TWO OF LIGHTNING AS THE UPPER LOW MOVES OVERHEAD...BUT WILL LEAVE OUT OF THE WEATHER GRIDS WITH IT TRACKING OVER IN THE MORNING. BY SUNDAY EVENING...PRECIPITATION WILL BE EAST OF THE AREA...THEN THE WINDS WILL PICK UP FROM THE NORTH-NORTHWEST. HIGH PRESSURE BUILDS IN QUICKLY TO CONFINE STRONGEST WINDS TO A 12 HOUR PERIOD SUNDAY...WEAKENING THROUGH THE NIGHT. RAINFALL AMOUNTS SATURDAY INTO SATURDAY EVENING WILL RANGE FROM A THIRD TO THREE-QUARTERS OF AN INCH. IF TODAYS RAIN IS SIGNIFICANT ENOUGH AND MODELS MAINTAIN SIMILAR QPF TOTALS FOR SATURDAY...A FLOOD WATCH MAY BE ISSUED. CONFIDENCE IS LOW AT THIS TIME. CONSIDER WINTERS GRIP ON THE AREA THIS YEAR...HESITANT TO GO WITH A LITTLE IF ANY SNOWFALL STATEMENT. BOTH THE NAM AND ECM PAINT A DUSTING TO AN INCH ACROSS THE MOUNTAINS AND INTO THE FOOTHILLS FROM MIDNIGHT TO NOON SUNDAY. THE GFS IS SIMILAR BUT WITH A 3-4 INCH BULLEYE CENTERED ON SNOWSHOE WV. WITH THE UPPER LEVEL LOW COMING OVER DURING THE MORNING...CHANCES ARE GOOD FOR SNOWFALL ESPECIALLY ACROSS THE WEST. IF THE UPPER LOW IS SLOW TO MOVE ACROSS THE AREA...THEN WE CAN NOT RULE OUT A COMMON INCH OR TWO ACROSS THE MOUNTAINS...SLIGHTLY HIGHER AMOUNTS ALONG HIGHER ELEVATIONS. HOWEVER...MODELS ZIP THE UPPER LOW ACROSS THE FORECAST AREA...WITH A NARROW BAND OF MOISTURE BEHIND IT...TO KEEP TOTALS UNDER AN INCH. THERE IS A WIDE RANGE IN GUIDANCE TEMPERATURES FOR SATURDAY. FOR EXAMPLE...GFSMOS FOR ROANOKE IS 66F WHILE THE NAM IS FORECASTING 50F. THE ECMMOS IS 61F. WITH RAIN EXPECTED FOR MUCH OF THE DAY...KEPT TEMPERATURES COOL...OBVIOUSLY BETWEEN GUIDANCE...SIMILAR TO PREVIOUS FORECAST. WITH AN EARLY EXIT OF THE CLOSED LOW...TEMPERATURES WILL REBOUND QUICKLY SUNDAY AFTERNOON. GUIDANCE WAS A LITTLE MORE HELPFUL WILL FORECASTED HIGHS AROUND 5F COLDER THAN NORMAL. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM EST THURSDAY... LOOKS LIKE MARCH WILL GO OUT LIKE A LAMB AS THE FIRST HALF OF NEXT WEEK LOOKS DRY. 1024 MB SURFACE HIGH IS PROGGED TO PASS OVHD MONDAY...FOLLOWED BY A DRY FRONTAL PASSAGE TUESDAY. ASIDE FOR SOME SCATTERED CLOUDS AND A WIND SHIFT TUESDAY...NO SENSIBLE WEATHER CHALLENGES ANTICIPATED FOR MONDAY THROUGH WEDNESDAY. THAT SAID...NOT QUITE AS PRISTINE FROM THE ROCKIES INTO THE UPPER MID WEST WHERE THE STORM TRACK WILL NOT BE AS FORGIVING. THIS MID CONUS STORMINESS WILL EVENTUALLY WORK ITS WAY TOWARD THE EAST COAST BY THE END OF THE WEEK WITH THE BAROCLINIC ZONE SLIDING BACK OUR WAY WITH THE THREAT FOR UNSETTLED WEATHER FROM THURSDAY INTO NEXT WEEKEND. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... AS OF 140 AM EDT FRIDAY... EXPECT VFR CONDITIONS THIS MORNING. HOWEVER...THERE WILL BE LOW LEVEL WIND SHEAR PRIOR TO SHOWERS ARRIVING AT ALL TERMINALS BUT BLF WHERE THEY WILL BE MIXING ABOVE THE INVERSION. CIGS WILL LOWER THROUGH THE MORNING WITH SHOWERS ENTERING BLF/LWB FIRST AROUND 10Z...REACHING BCB/ROA 11-12Z AND MAKING IT TOWARD LYH/DAN 13-15Z. THERE WILL BE PERIODS OF MODERATE SHOWERS WHICH COULD TAKE THE VSBY DOWN TO MVFR...BUT AMOUNT OF TIME THIS OCCURS WILL BE LESS THAN TEMPO GROUPS PROVIDE EXCEPT BCB IN THE 12-14Z. THIS AFTERNOON...THE MAIN AREA OF SHOWERS WILL BE SHIFTING SE OF THE AREA...BUT WILL STILL SEE SPOTTY SHOWERS AROUND...BUT AGAIN TOUGH TO PINPOINT WHEN AND IF IT WILL HIT ANY TAF SITES. SHOULD SEE SOME MVFR IMPROVE BACK TO VFR THIS AFTERNOON AS WELL. THE NEXT UPSTREAM WAVE OF LOW PRESSURE WILL BUCKLE THE FRONT TOWARD THE NORTH...AND MODELS FAVOR A RETURN TO EITHER LIGHT RAIN/DRIZZLE AT MOST SITES FRIDAY EVENING WITH CIGS DROPPING BACK TO LOW END MVFR AND SOME IFR. ANOTHER STRONGER COLD FRONT WILL MOVE THROUGH THE REGION ON SATURDAY. THERE WILL BE BETTER CHANCE FOR SOME ISOLATED TO SCATTERED THUNDERSTORMS BE ASSOCIATED WITH THE FRONT. AGAIN...MOST AREAS WILL REMAIN VFR OUTSIDE THE STRONGER CELLS ALONG THE FRONT. SATURDAY NIGHT INTO SUNDAY...STRONG NORTHWEST WINDS ARE EXPECTED AS THE PARENT UPPER LOW MAKES ITS WAY ACROSS THE AREA. UPSLOPE SHOWERS ARE POSSIBLE ALONG A KLWB-KBLF LINE INTO SUNDAY. DRY WEATHER AND VFR CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. && .EQUIPMENT... AS OF 135 AM EDT THURSDAY... ACCESS TO DATA ON OUR WEB PAGE...WWW.ERH.NOAA.GOV/RNK/...REMAINS LIMITED DUE TO REGIONAL SERVER ISSUES. THERE IS NO ESTIMATE AT THIS TIME FOR WHEN IT WILL BE REPAIRED. OUR NEW...BUT UNFINISHED SITE...WWW.WEATHER.GOV/RNK/ IS OPERATING PROPERLY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...WP NEAR TERM...WP SHORT TERM...RCS LONG TERM...PM AVIATION...DS/JC/WP EQUIPMENT...AMS/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1044 PM CDT SAT MAR 29 2014 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND SUNDAY ISSUED AT 248 PM CDT SAT MAR 29 2014 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM QUEBEC TO THE WESTERN GREAT LAKES TO THE STATE OF TEXAS. EARLIER RIBBON OF STRATO-CU OVER PARTS OF CENTRAL AND NORTHEAST WISCONSIN DISSIPATED AROUND MIDDAY LEAVING MOSTLY SUNNY CONDITIONS ACROSS THE NORTHERN HALF OF THE STATE. LOOKING UPSTREAM...THE JET IS PUSHING MID AND HIGH CLOUDS TO THE EAST ACROSS THE PLAINS. BUT OTHERWISE QUIET CONDITIONS EXIST UNTIL NORTHWEST MONTANA IN THE VICINITY OF SHORTWAVE ENERGY. WITH THAT SHORTWAVE EXPECTED TO PASS NORTH OF THE REGION...THE MAIN FORECAST CONCERNS INCLUDE CLOUDS AND TEMPS IN THE SHORT TERM. TONIGHT...SURFACE HIGH PRESSURE WILL SHIFT FROM THE WESTERN TO THE CENTRAL GREAT LAKES WHILE THE MID-LEVEL RIDGE AXIS WORKS ACROSS THE STATE. SHORTWAVE ENERGY MOVING ACROSS SOUTHERN CANADA WILL SEND MID AND HIGH CLOUDS ACROSS NORTHERN MINNESOTA AND LAKE SUPERIOR. BUT SOME OF THESE CLOUDS WILL LIKELY GRAZE NORTHERN WISCONSIN. OTHERWISE...MOSTLY CLEAR TO CLEAR CONDITIONS WILL PREVAIL. DEVELOPING SOUTHEAST WINDS WILL LIKELY TEMP KEEPS FROM PLUMMETING OVER THE DEEP SNOW PACK OF N-C WISCONSIN. TEMPS MAINLY IN THE 20...EXCEPT FOR A FEW TEENS OVER FAR NE WISCONSIN. SUNDAY...RETURN FLOW WILL BE RAMPING UP THROUGH THE DAY AS LOW PRESSURE EMERGES INTO THE CENTRAL PLAINS. AT THE SAME TIME...A COLD FRONT WILL BE SAGGING SOUTHEAST ACROSS MINNESOTA AND INTO FAR NW WISCONSIN BY LATE IN THE AFTERNOON. SOUTH TO SOUTHEAST WINDS WILL BE ADVECTING WARMER AIR IN THE LOW LEVELS WHICH WILL LEAD TO A WARMER DAY ACROSS THE REGION. THE EXCEPTION WILL BE ALONG THE LAKE AND BAY SHORE WHERE ONSHORE FLOW WILL PUSH IN A COLD MARINE LAYER. SO WILL GO WITH HIGHS IN THE UPPER 50S IN THE WARM SPOTS...TO THE UPPER 30S ALONG LAKE MICHIGAN. SHOULD SEE MORE IN THE WAY OF MID AND HIGH CLOUDS WHICH WILL PROVIDE FILTERED SUNSHINE AT TIMES...BUT DO NOT THINK THEY WILL HAVE MUCH IMPACT ON TEMPS. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY ISSUED AT 248 PM CDT SAT MAR 29 2014 THE MODELS ARE NOW IN FAIRLY GOOD AGREEMENT THAT THE SYSTEM MOVING OUT OF THE CENTRAL PLAINS WILL TRACK TO THE WEST OF OUR FORECAST AREA...RESULTING IN MOSTLY RAIN AND A CHANCE OF THUNDERSTORMS. THE RAIN SHOULD ARRIVE FROM WEST TO EAST MONDAY AFTERNOON AND CONTINUE MONDAY NIGHT. COLDER AIR AND SNOW SHOWERS ARE LIKELY TUESDAY. THE MAIN CONCERN FROM THE RAIN AND WARMER TEMPERATURES IS MELTING SNOW AND RIVER ICE WITH THE POSSIBILITY OF LOCAL FLOODING. HIGH PRESSURE BUILDS IN TUESDAY NIGHT AND WEDNESDAY BEFORE ANOTHER SYSTEM APPROACHES FROM THE SOUTHERN PLAINS. THE GFS IS MUCH FASTER AND FLATTER WITH THE SURFACE SYSTEM AND WE WOULD BE IN THE NORTHERN FRINGE OF IT AND RECEIVE SOME SNOW WHILE THE ECMWF IS SLOWER AND STRONGER AND WE WOULD HAVE PRECIPITATION TYPE ISSUES DUE TO A MORE NORTHERLY TRACK. THEN A LITTLE COLDER AND DRY WEATHER EXPECTED FRIDAY AND SATURDAY. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1040 PM CDT SAT MAR 29 2014 CLEAR SKIES COVERED NORTHEAST WISCONSIN LATE THIS EVENING. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD...WITH AN INCREASE IN MID-LEVEL CLOUDS EXPECTED BY SUNDAY MORNING. SOME STRATOCUMULUS MAY DEVELOP IN NC/C WI SUNDAY EVENING...BUT CIGS SHOULD BE 4000-6000 FT. INCREASING SOUTH FLOW WILL RESULT IN GUSTS TO NEAR 20 KTS SUNDAY AFTERNOON. AS SFC WINDS DECREASE AND WINDS ALOFT INCREASE ON SUNDAY EVENING...SOME MARGINAL LLWS SHOULD DEVELOP AT ALL OF THE TAF SITES. && .HYDROLOGY... ISSUED AT 248 PM CDT SAT MAR 29 2014 WARMER TEMPERATURES...MELTING SNOW AND RAIN WILL PRODUCE AN INCREASE IN THE CHANCES OF LOCAL FLOODING EARLY NEXT WEEK. THE SNOW IS VERY DEEP IN THE NORTH AND SHOULD BE ABLE TO ABSORB THE RAINFALL WITHOUT FULLY MELTING BUT PLACES WITH JUST A FEW INCHES LEFT MAY HAVE MOST OF IT MELT AND RUN OFF THE FROZEN GROUND INTO RIVERS AND STREAMS. THERE IS ALSO A CHANCE OF ICE JAMS AS RIVER ICE BREAKS UP. WE HAVE A HYDROLOGICAL OUTLOOK IN EFFECT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......KIECKBUSCH HYDROLOGY......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 PM CDT FRI MAR 28 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 346 PM CDT FRI MAR 28 2014 AT 3 PM...WATER VAPOR SHOWED A WEAKENING SHORT WAVE TROUGH MOVING INTO SOUTHWEST MINNESOTA...AND MORE IMPRESSIVE SHORT WAVE MOVING THROUGH SOUTHERN MISSOURI. THE 28.00Z MODELS ARE IN GENERAL AGREEMENT THAT THE NORTHERN SYSTEM WILL CONTINUE TO WEAK TONIGHT AND THE SOUTHERN STREAM SYSTEM WILL REMAIN THE DOMINANT SYSTEM. THESE 2 SYSTEMS EVENTUALLY MERGE ACROSS CENTRAL ILLINOIS AND INDIANA WITH AN INVERTED TROUGH EXTENING NORTHWEST TOWARD NORTHEAST IOWA AND SOUTHWEST WISCOSNIN. WITH NORTHERLY FLOW BRINGING DRIER AIR INTO THE REGION...THIS TROUGH WILL HAVE VERY LITTLE MOISTURE TO WORK WITH. AS A RESULT...JUST EXPECT SOME CLOUDS WITH THIS SYSTEM FOR TONIGHT AND EARLY SATURDAY MORNING. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 346 PM CDT FRI MAR 28 2014 ON SUNDAY...THERE IS A BIT OF CONCERN ON THE HIGH TEMPERATURES. MUCH OF THIS HAS TO DEAL WITH THE SPEED OF THE SYSTEM EJECTING OUT OF THE CENTRAL PLAINS. THE NAM IS MUCH FASTER AT EJECTING THIS SYSTEM TOWARD THE REGION...THUS...THE SOUTHERLY WINDS ARE MUCH STRONGER ACROSS THE AREA. MEANWHILE THE GFS...GEM...AND ECMWF ARE WEAKER WITH THESE SOUTHERLY WINDS. IN ADDITION...THESE MODELS ALLOW A CANADIAN COLD FRONT DROP A BIT FURTHER SOUTH INTO THE FORECAST AREA. AS A RESULT...THERE IS SOME CONCERN THAT TEMPERATURES MAY NOT GET AS WARM NORTH OF THE INTERSTATE 90 CORRIDOR. SINCE THE CONSENSUS WAS TO GO WITH THE LATTER MODELS...COOLED THE HIGH TEMPERATURES A BIT NORTH OF INTERSTATE 90. FROM SUNDAY NIGHT INTO MONDAY NIGHT...BOTH THE GEM AND ECWMF HAVE SLOWED THEIR MOVEMENT OF THE SURFACE LOW AND STRONG NEGATIVELY TILTED SHORT WAVE TROUGH THE REGION. THEY ARE NOW MUCH CLOSER TO THE GFS SOLUTION WHICH DOES NOT MOVE THESE SYSTEM THROUGH THE AREA UNTIL THE LATE AFTERNOON AND EVENING. THIS SLOW DOWN IS NOTHING UNUSUAL WITH SOUTHWEST SYSTEMS AND WOULD NOT BE SURPRISED TO SEE SOME MORE SLOWING WITH THIS SYSTEM. MEANWHILE THE NAM/WRF HAS A SLIGHTLY WEAKER WAVE WAVE ALOFT AND THE SURFACE LOW MOVES QUICKLY NORTHEAST THROUGH THE AREA ON MONDAY NIGHT. THIS MODEL APPEARS TO BE AN OUTLIER...SO IT WAS NOT USED FOR THIS TIME PERIOD. WHILE THE GFS...GEM...AND ECMWF ARE IN GOOD AGREEMENT WITH OVER 50 KNOTS OF 0-6 KM SHEAR AND HELICITIES OF OVER 500 WITH THIS WAVE...THEY DIFFER ON THE MOST UNSTABLE CAPE ACROSS THE REGION. THE GFS HAS MUCH MORE PRECIPITATION IN THE WARM SECTOR OF THIS SYSTEM /WHICH COVERS THE SOUTHERN 2/3RDS OF THE FORECAST AREA/. AS A RESULT...IT HAS VERY LITTLE CAPE. THE ECWMF HAS A SLIGHTLY MORE CLEANER OF THE WARM SECTOR OF THIS SYSTEM PRIOR TO THE COLD FRONT...THUS...IT HAS SLIGHTLY GREATER MOST UNSTABLE CAPES /UP TO 300 J/KG/. THE GEM HAS VERY LITTLE CONVECTION IN THE WARM SECTOR PRIOR TO THE COLD FRONT. THIS ALLOWS THE MOST UNSTABLE CAPES TO CLIMB UP TO 700 J/KG. WITH THIS LATTER SCENARIO...THERE WOULD BE MORE CONCERN ABOUT THE POTENTIAL FOR SUPER CELL THUNDERSTORMS. WHILE THERE IS STILL A LOT OF UNCERTAINTY ON THE SEVERE WEATHER THREAT...THE STRENGTH OF THIS SYSTEM AND THE POTENTIAL FOR SLANTWISE AND UPRIGHT CONVECTION LOOKS TO BE ENOUGH TO WARRANT AT LEAST THE MENTION OF THUNDER ACROSS THE ENTIRE FORECAST AREA FROM MONDAY AFTERNOON INTO MONDAY EVENING. IN ADDITION WITH THE SLOWER MOVEMENT INTO THE AREA...INCREASED MONDAY HIGH TEMPERATURES AND MONDAY NIGHT LOW TEMPERATURES ACROSS THE NORTHEAST IOWA AND WESTERN WISCONSIN. FROM TUESDAY NIGHT THROUGH FRIDAY...THE 28.12Z MODELS CONTINUE TO STRUGGLE WITH THE TRACK OF 2 LOW PRESSURE SYSTEMS THROUGH THE MID AND UPPER MISSISSIPPI RIVER VALLEY. THE ECWMWF HAS SHIFTED FURTHER NORTH...RESULTING IN MORE OF A RAIN SOLUTION FOR THE AREA. MEANWHILE THE GFS AND GEM HAVE A MUCH MORE ACTIVE SOUTHERN STREAM SYSTEM. AS A RESULT...THERE IS MORE OF A MIX FOR THE WEDNESDAY THROUGH THURSDAY...AND THE SYSTEM FOR THURSDAY NIGHT AND FRIDAY WILL BE SOUTH OF THE AREA. DUE TO THIS POOR MODEL CONSISTENCY AND AGREEMENT...JUST STAYED WITH MODEL CONSENSUS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1241 PM CDT FRI MAR 28 2014 MAIN AVIATION CONCERN IS MVFR STRATUS DECK SOUTH OF TAF SITES TO PERSIST THIS AFTERNOON. LATEST 28.12Z NAM AND 28.15Z RAP NOT HANDLING THE ERODING OF LOW STRATUS DECK/MOISTURE WELL PER LATEST VISIBLE SATELLITE IMAGERY. WITH DRY NORTHERLY FLOW AND SUBSIDENCE UNDER SURFACE HIGH OVER NORTHERN MINNESOTA...EXPECT THE MVFR/STRATUS DECK TO DIMINISH ON NORTHERN PERIPHERY AND PRODUCE A SCATTER DECK OF 2500 TO 3500 FEET AT THE RST/LSE TAF SITES THIS AFTERNOON. WEAK LOW PRESSURE WILL MOVE INTO THE CENTRAL PLAINS STATES THIS AFTERNOON/TONIGHT AND SPREAD A MID DECK(ABOVE 10K FEET) OF CLOUDS OVER THE TAF SITES. THE 28.12Z GFS/NAM BUFKIT SOUNDINGS ARE SHOWING AN INVERSION DEVELOPING TONIGHT AND MOISTENING UP THE NEAR SURFACE BOUNDARY LAYER. THIS MOISTURE LOOKS OVERDONE...AS REGION WILL BE UNDER THE INFLUENCE OF SURFACE HIGH OVER NORTHERN WISCONSIN. EXPECT VFR CONDITIONS TO PREVAIL AT BOTH LSE/RST TAF SITES TONIGHT THROUGH THE REST OF THE TAF PERIOD. && .HYDROLOGY... ISSUED AT 346 PM CDT FRI MAR 28 2014 MINOR FLOODING IS EXPECTED TO CONTINUE INTO SATURDAY ALONG PARTS OF KICKAPOO AS RUNOFF FROM LAST NIGHT/S RAINFALL WORKS ITS WAY DOWN THE RIVER. FROM SUNDAY INTO MONDAY NIGHT...THE RAPID WARM UP WILL CAUSE THE SNOW PACK NORTH OF INTERSTATE 94 TO MELT RAPIDLY. IN ADDITION WITH FROZEN GROUND...ADDITIONAL RAINFALL ON MONDAY AND MONDAY NIGHT WILL QUICKLY RUNOFF INTO AREA RIVERS AND STREAMS. THIS WILL RESULT IN RISES ALONG THE BLACK...BUFFALO...AND TREMPEALEAU RIVERS IN WESTERN WISCONSIN. THERE IS A DISTINCT POSSIBILITY THAT THERE WILL BE THE POTENTIAL FOR SOME FLOODING ALONG THESE RIVERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...DTJ HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1241 PM CDT FRI MAR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 311 AM CDT FRI MAR 28 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING ALONG THE U.S. WEST COAST INTO BRITISH COLUMBIA...A PACIFIC SHORTWAVE OVER WYOMING...A VIGOROUS PACIFIC SHORTWAVE NEAR DAVENPORT IA...AND A POLAR SHORTWAVE OVER LAKE WINNIPEG. THE DAVENPORT IA SHORTWAVE...IN COMBINATION WITH PRECIPITABLE WATER VALUES OF 0.6-0.9 INCHES / 200 PERCENT OF NORMAL / AND FRONTOGENESIS HELPED PRODUCE PRECIPITATION ACROSS MUCH OF THE FORECAST AREA YESTERDAY TO AROUND MIDNIGHT. MUCH OF THIS PRECIPITATION FELL AS RAIN...WHICH WITH FROZEN GROUND HAS LED TO PLENTY OF RUNOFF AND RISES ON AREA RIVERS AND STREAMS. SEE THE HYDROLOGY SECTION FOR MORE INFORMATION. SOME OF THE PRECIPITATION FELL AS SNOW...MAINLY IN NORTHWEST TO NORTH SECTIONS OF THE AREA...WITH THE MOST IN TAYLOR COUNTY. LOW LEVEL CYCLONIC FLOW AROUND LOW PRESSURE OVER CENTRAL LAKE MICHIGAN HAS KEPT CLOUDS IN PLACE THROUGH THE NIGHT...THOUGH CLEARING WAS EVIDENT OVER THE NORTHWEST HALF OF MINNESOTA. PRECIPITABLE WATER AT BIS WAS QUITE LOW WITH THE RIDGE...0.17 INCHES AT BIS AND ABR OR 50-60 PERCENT OF NORMAL. COLDER AIR WAS ALSO FILTERING IN...REFLECTING A CANADIAN RIDGE OF HIGH PRESSURE BUILDING SOUTH INTO THE UPPER MIDWEST. FARTHER TO THE WEST...CLOUDS AND SOME SCATTERED LIGHT PRECIPITATION WAS OCCURRING OVER WYOMING WITH THE SHORTWAVE THERE. AFTER AN ACTIVE PERIOD OF PRECIPITATION THE PAST 24 HOURS...THIS SHORT TERM PERIOD LOOKS MUCH QUIETER. FOCUS FOR ANY POTENTIAL PRECIPITATION WOULD BE ON THE SHORTWAVE OVER WYOMING...WHICH IS PROGGED BY MODELS TO CROSS THE FORECAST AREA TONIGHT. HOWEVER... THERE ARE 2 ITEMS GOING AGAINST PRECIPITATION... 1. ANOTHER SHORTWAVE COMING OUT OF ARIZONA IS SUGGESTED TO INTENSIFY AND DEEPEN AS IT REACHES MISSOURI TONIGHT...ROBBING THE WYOMING SHORTWAVE OF MOISTURE. 2. THE WYOMING SHORTWAVE WILL BE HEADING INTO A DRY AIRMASS AS SEEN ON THE BIS/ABR SOUNDINGS. MODELS CONTINUE TO DEPICT THAT ANY PRECIPITATION WITH THE SHORTWAVE WILL DRY UP BEFORE THE SHORTWAVE GETS TO THE FORECAST AREA...THUS STAYED WITH A DRY FORECAST. CLOUDS AND TEMPERATURES NOW BECOME THE MAIN CONCERNS. LOW CLOUDS LOOK TO QUICKLY EXIT OFF TO THE EAST THIS MORNING AS THE DRIER AIR TO OUR NORTHWEST ADVECTS IN. SCT-BKN MID AND HIGH CLOUDS WILL THEN TRAVERSE THE AREA THIS AFTERNOON THROUGH TONIGHT AS THE WYOMING SHORTWAVE MOVES THROUGH. 925MB TEMPS ARE PROGGED BETWEEN -2 TO -6C AT 18Z...THOUGH MORE SUN TODAY WILL HELP TO COUNTERACT SOME OF THE COLDER AIR. IN FACT...OVER THE SNOW FREE AREAS...TEMPERATURES MAY EVEN END UP A LITTLE WARMER THAN YESTERDAY. ALTHOUGH SURFACE WINDS LOOK LIGHT TONIGHT...THE CLOUDS SHOULD HELP TO HOLD READINGS UP FROM THE MID TEENS TO MID 20S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 311 AM CDT FRI MAR 28 2014 MUCH OF THE LONG TERM PERIOD FOCUSES ON AN IMPRESSIVE LONG WAVE TROUGH SITTING OVER THE EASTERN PACIFIC. ALL MODELS SHOW THAT A POTENT SHORTWAVE WILL COME OUT OF THIS TROUGH AND TRACK INTO THE FORECAST AREA FOR MONDAY. THEN THE ENTIRE TROUGH LOOKS TO COME INTO THE WESTERN U.S. ON TUESDAY...TRACKING INTO THE CENTRAL PLAINS ON THURSDAY. MUCH OF FRIDAY NIGHT THROUGH SUNDAY LOOKS TO BE DOMINATED BY BUILDING RIDGING AHEAD OF THE POTENT SHORTWAVE MARCHING ACROSS THE WESTERN U.S.. NO CONCERNS FOR PRECIPITATION DURING THIS PERIOD AS THE FORECAST AREA TRANSITIONS FROM UNDER DOMINANCE OF HIGH PRESSURE TO INTO THE WARM SECTOR OF A DEEPENING SURFACE CYCLONE OVER NORTHEAST COLORADO. TEMPERATURES AND WINDS ARE THE MAIN ISSUES. 925MB TEMPS ARE PROGGED SLIGHTLY WARMER ON SATURDAY...0 TO - 4C...WHICH WITH WHAT LOOKS TO BE PLENTY OF SUN SHOULD HELP BOOST TEMPS INTO THE 40S...PERHAPS EVEN AROUND 50 IN SOME VALLEY LOCATIONS. SOUTH TO SOUTHWEST WINDS REALLY PICK UP SATURDAY NIGHT...UPWARDS OF 40-50 KT BY 12Z SUN AT 925MB...CAUSING 925-850MB TEMPS TO REALLY CLIMB. ANTICIPATING LOWS IN THE EVENING SATURDAY NIGHT...THEN HOLD STEADY TO SLOWLY RISE AS THE WARM AIR SURGES IN. THE CLIMB CONTINUES THROUGH SUNDAY AS THE 925MB TEMPS CLIMB TO AS MUCH AS 10-13C BY 00Z MONDAY. 400-250MB RH PROGS SUGGESTS PLENTY OF SCT-BKN CIRRUS...BUT THE SUN AND WARM 925MB TEMPS SHOULD HELP PROPEL READINGS INTO THE FIRST 60S OF THE YEAR FOR MOST LOCATIONS. MORE SNOWPACK OVER TAYLOR/CLARK WILL HOLD READINGS BACK THERE INTO THE 50S...THOUGH THIS SNOWPACK IS GOING TO MELT FAST GIVEN THE WARM AIR AND BREEZY CONDITIONS...YIELDING HYDRO CONCERNS. SEE HYDROLOGY SECTION. ATTENTION THEN TURNS TO THE POTENT SHORTWAVE HEADING INTO THE FORECAST AREA FOR MONDAY. BOTH THE GFS AND ECMWF HAVE REALLY SLOWED AND DEEPENED THIS SHORTWAVE AND THE ASSOCIATED SURFACE LOW OVER THE PAST 24-48 HOURS. THIS RESULTS IN THE FORECAST AREA STAYING IN THE WARM SECTOR LONGER AND THUS WARMER CONDITIONS ARE FORECAST FOR SUNDAY NIGHT AND MONDAY. THERE ARE A COUPLE OF PRECIPITATION IMPACTS TOO. FIRST...THE DEFORMATION BAND ON THE NORTHWEST SIDE OF THE LOW NOW ONLY LOOKS TO IMPACT THE NORTHWEST HALF OF THE AREA MONDAY AFTERNOON AND NIGHT...THOUGH IT MAY STAY ENTIRELY NORTHWEST OF THE FORECAST AREA. SECOND...A LEAD WAVE OF RAIN RESULTING FROM ISENTROPIC LIFT IS LOOKING LIKELY TO PROGRESS ACROSS THE FORECAST AREA LATE SUNDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THIRD...THE SYSTEMS COLD FRONT AND STRONG DYNAMICS ARE PROGGED TO MOVE THROUGH MONDAY AFTERNOON AND EVENING. THERE IS A CAP TO BE OVERCOME...BUT WITH SUCH STRONG FORCING...CANNOT RULE OUT A BAND OF SHOWERS AND STORMS FIRING ON THE FRONT. SHOULD STORMS FORM...WHICH IS A BIG IF...THERE IS AMPLE SHEAR TO SUPPORT SEVERE. WE WILL NEED TO KEEP AN EYE ON INSTABILITY VERSUS CAPPING FOR MONDAY AFTERNOON. TUESDAY INTO TUESDAY NIGHT LOOK TO BE QUIET AND MUCH COLDER...THEN WEATHER GETS ACTIVE AGAIN FOR WEDNESDAY INTO THURSDAY AS THE REST OF THE UPPER TROUGH LIFTS TOWARDS THE REGION. THIS TIME AROUND...WE MAY HAVE TO DEAL WITH A WINTRY MIX SIDE DUE TO WARM/MOIST ADVECTION ALOFT AND A FLOW OF DRY AIR AND COLD ADVECTION AT THE SURFACE. THEN...IF THE 28.00Z ECMWF IS CORRECT...WE WILL AT LEAST CHANGE OVER TO ALL RAIN AND PERHAPS BRING MORE THUNDERSTORMS. NEEDLESS TO SAY...PLENTY OF UNCERTAINTY OUT THIS FAR AND THUS STAYED WITH A MODEL CONSENSUS FOR NOW. CERTAINLY ANOTHER ITEM TO WATCH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1241 PM CDT FRI MAR 28 2014 MAIN AVIATION CONCERN IS MVFR STRATUS DECK SOUTH OF TAF SITES TO PERSIST THIS AFTERNOON. LATEST 28.12Z NAM AND 28.15Z RAP NOT HANDLING THE ERODING OF LOW STRATUS DECK/MOISTURE WELL PER LATEST VISIBLE SATELLITE IMAGERY. WITH DRY NORTHERLY FLOW AND SUBSIDENCE UNDER SURFACE HIGH OVER NORTHERN MINNESOTA...EXPECT THE MVFR/STRATUS DECK TO DIMINISH ON NORTHERN PERIPHERY AND PRODUCE A SCATTER DECK OF 2500 TO 3500 FEET AT THE RST/LSE TAF SITES THIS AFTERNOON. WEAK LOW PRESSURE WILL MOVE INTO THE CENTRAL PLAINS STATES THIS AFTERNOON/TONIGHT AND SPREAD A MID DECK(ABOVE 10K FEET) OF CLOUDS OVER THE TAF SITES. THE 28.12Z GFS/NAM BUFKIT SOUNDINGS ARE SHOWING AN INVERSION DEVELOPING TONIGHT AND MOISTENING UP THE NEAR SURFACE BOUNDARY LAYER. THIS MOISTURE LOOKS OVERDONE...AS REGION WILL BE UNDER THE INFLUENCE OF SURFACE HIGH OVER NORTHERN WISCONSIN. EXPECT VFR CONDITIONS TO PREVAIL AT BOTH LSE/RST TAF SITES TONIGHT THROUGH THE REST OF THE TAF PERIOD. && .HYDROLOGY... ISSUED AT 311 AM CDT FRI MAR 28 2014 AREA RIVERS AND STREAMS CONTINUE TO MOSTLY RISE EARLY THIS MORNING FROM THE RECENT RAIN. RAINFALL AMOUNTS AS MUCH AS A LITTLE OVER 1 INCH WERE OBSERVED...HIGHEST OVER THE SOUTHEAST HALF OF THE FORECAST AREA. WITH FROZEN GROUND...MUCH OF THIS RAIN HAS TURNED INTO RUNOFF. SO FAR THE ONLY FLOOD WARNING ISSUED AND VERIFIED WAS ONTARIO...WHILE MOST OTHER RIVERS AND STREAMS ARE STAYING BELOW FLOOD STAGE. EXPECTING MOST SHORT RESPONDING SITES LIKE ONTARIO TO BEGIN FALLING SOON...WHILE LONGER RESPONDING LOCATIONS WILL CLIMB FOR THE NEXT DAY OR SO AS RUNOFF CONTINUES TO FILTER THROUGH. SEE THE LATEST HYDROLOGY RELATED STATEMENTS FOR MORE DETAILS. NEXT HYDROLOGY CONCERN COMES SUNDAY THROUGH MONDAY AS A STRONG SURGE OF WARM AIR COMES INTO THE REGION ON BREEZY SOUTH WINDS. IN ADDITION...RAIN APPEARS LIKELY ON MONDAY. WITH PLENTY OF SNOW STILL PRESENT ALONG/NORTH OF HIGHWAY 10...CONCERN THAT THIS SNOW COULD RAPIDLY MELT...RESULTING IN MORE RISES ON RIVERS SUCH AS THE TREMPEALEAU AND BLACK. WILL ISSUE AN ESF TO COVER THE POTENTIAL FOR FLOODING. SOMEWHAT COOLER AIR FLOWING IN FOR TUESDAY AND WEDNESDAY WILL SLOW THE MELT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DTJ HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
646 AM CDT FRI MAR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 311 AM CDT FRI MAR 28 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING ALONG THE U.S. WEST COAST INTO BRITISH COLUMBIA...A PACIFIC SHORTWAVE OVER WYOMING...A VIGOROUS PACIFIC SHORTWAVE NEAR DAVENPORT IA...AND A POLAR SHORTWAVE OVER LAKE WINNIPEG. THE DAVENPORT IA SHORTWAVE...IN COMBINATION WITH PRECIPITABLE WATER VALUES OF 0.6-0.9 INCHES / 200 PERCENT OF NORMAL / AND FRONTOGENESIS HELPED PRODUCE PRECIPITATION ACROSS MUCH OF THE FORECAST AREA YESTERDAY TO AROUND MIDNIGHT. MUCH OF THIS PRECIPITATION FELL AS RAIN...WHICH WITH FROZEN GROUND HAS LED TO PLENTY OF RUNOFF AND RISES ON AREA RIVERS AND STREAMS. SEE THE HYDROLOGY SECTION FOR MORE INFORMATION. SOME OF THE PRECIPITATION FELL AS SNOW...MAINLY IN NORTHWEST TO NORTH SECTIONS OF THE AREA...WITH THE MOST IN TAYLOR COUNTY. LOW LEVEL CYCLONIC FLOW AROUND LOW PRESSURE OVER CENTRAL LAKE MICHIGAN HAS KEPT CLOUDS IN PLACE THROUGH THE NIGHT...THOUGH CLEARING WAS EVIDENT OVER THE NORTHWEST HALF OF MINNESOTA. PRECIPITABLE WATER AT BIS WAS QUITE LOW WITH THE RIDGE...0.17 INCHES AT BIS AND ABR OR 50-60 PERCENT OF NORMAL. COLDER AIR WAS ALSO FILTERING IN...REFLECTING A CANADIAN RIDGE OF HIGH PRESSURE BUILDING SOUTH INTO THE UPPER MIDWEST. FARTHER TO THE WEST...CLOUDS AND SOME SCATTERED LIGHT PRECIPITATION WAS OCCURRING OVER WYOMING WITH THE SHORTWAVE THERE. AFTER AN ACTIVE PERIOD OF PRECIPITATION THE PAST 24 HOURS...THIS SHORT TERM PERIOD LOOKS MUCH QUIETER. FOCUS FOR ANY POTENTIAL PRECIPITATION WOULD BE ON THE SHORTWAVE OVER WYOMING...WHICH IS PROGGED BY MODELS TO CROSS THE FORECAST AREA TONIGHT. HOWEVER... THERE ARE 2 ITEMS GOING AGAINST PRECIPITATION... 1. ANOTHER SHORTWAVE COMING OUT OF ARIZONA IS SUGGESTED TO INTENSIFY AND DEEPEN AS IT REACHES MISSOURI TONIGHT...ROBBING THE WYOMING SHORTWAVE OF MOISTURE. 2. THE WYOMING SHORTWAVE WILL BE HEADING INTO A DRY AIRMASS AS SEEN ON THE BIS/ABR SOUNDINGS. MODELS CONTINUE TO DEPICT THAT ANY PRECIPITATION WITH THE SHORTWAVE WILL DRY UP BEFORE THE SHORTWAVE GETS TO THE FORECAST AREA...THUS STAYED WITH A DRY FORECAST. CLOUDS AND TEMPERATURES NOW BECOME THE MAIN CONCERNS. LOW CLOUDS LOOK TO QUICKLY EXIT OFF TO THE EAST THIS MORNING AS THE DRIER AIR TO OUR NORTHWEST ADVECTS IN. SCT-BKN MID AND HIGH CLOUDS WILL THEN TRAVERSE THE AREA THIS AFTERNOON THROUGH TONIGHT AS THE WYOMING SHORTWAVE MOVES THROUGH. 925MB TEMPS ARE PROGGED BETWEEN -2 TO -6C AT 18Z...THOUGH MORE SUN TODAY WILL HELP TO COUNTERACT SOME OF THE COLDER AIR. IN FACT...OVER THE SNOW FREE AREAS...TEMPERATURES MAY EVEN END UP A LITTLE WARMER THAN YESTERDAY. ALTHOUGH SURFACE WINDS LOOK LIGHT TONIGHT...THE CLOUDS SHOULD HELP TO HOLD READINGS UP FROM THE MID TEENS TO MID 20S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 311 AM CDT FRI MAR 28 2014 MUCH OF THE LONG TERM PERIOD FOCUSES ON AN IMPRESSIVE LONG WAVE TROUGH SITTING OVER THE EASTERN PACIFIC. ALL MODELS SHOW THAT A POTENT SHORTWAVE WILL COME OUT OF THIS TROUGH AND TRACK INTO THE FORECAST AREA FOR MONDAY. THEN THE ENTIRE TROUGH LOOKS TO COME INTO THE WESTERN U.S. ON TUESDAY...TRACKING INTO THE CENTRAL PLAINS ON THURSDAY. MUCH OF FRIDAY NIGHT THROUGH SUNDAY LOOKS TO BE DOMINATED BY BUILDING RIDGING AHEAD OF THE POTENT SHORTWAVE MARCHING ACROSS THE WESTERN U.S.. NO CONCERNS FOR PRECIPITATION DURING THIS PERIOD AS THE FORECAST AREA TRANSITIONS FROM UNDER DOMINANCE OF HIGH PRESSURE TO INTO THE WARM SECTOR OF A DEEPENING SURFACE CYCLONE OVER NORTHEAST COLORADO. TEMPERATURES AND WINDS ARE THE MAIN ISSUES. 925MB TEMPS ARE PROGGED SLIGHTLY WARMER ON SATURDAY...0 TO - 4C...WHICH WITH WHAT LOOKS TO BE PLENTY OF SUN SHOULD HELP BOOST TEMPS INTO THE 40S...PERHAPS EVEN AROUND 50 IN SOME VALLEY LOCATIONS. SOUTH TO SOUTHWEST WINDS REALLY PICK UP SATURDAY NIGHT...UPWARDS OF 40-50 KT BY 12Z SUN AT 925MB...CAUSING 925-850MB TEMPS TO REALLY CLIMB. ANTICIPATING LOWS IN THE EVENING SATURDAY NIGHT...THEN HOLD STEADY TO SLOWLY RISE AS THE WARM AIR SURGES IN. THE CLIMB CONTINUES THROUGH SUNDAY AS THE 925MB TEMPS CLIMB TO AS MUCH AS 10-13C BY 00Z MONDAY. 400-250MB RH PROGS SUGGESTS PLENTY OF SCT-BKN CIRRUS...BUT THE SUN AND WARM 925MB TEMPS SHOULD HELP PROPEL READINGS INTO THE FIRST 60S OF THE YEAR FOR MOST LOCATIONS. MORE SNOWPACK OVER TAYLOR/CLARK WILL HOLD READINGS BACK THERE INTO THE 50S...THOUGH THIS SNOWPACK IS GOING TO MELT FAST GIVEN THE WARM AIR AND BREEZY CONDITIONS...YIELDING HYDRO CONCERNS. SEE HYDROLOGY SECTION. ATTENTION THEN TURNS TO THE POTENT SHORTWAVE HEADING INTO THE FORECAST AREA FOR MONDAY. BOTH THE GFS AND ECMWF HAVE REALLY SLOWED AND DEEPENED THIS SHORTWAVE AND THE ASSOCIATED SURFACE LOW OVER THE PAST 24-48 HOURS. THIS RESULTS IN THE FORECAST AREA STAYING IN THE WARM SECTOR LONGER AND THUS WARMER CONDITIONS ARE FORECAST FOR SUNDAY NIGHT AND MONDAY. THERE ARE A COUPLE OF PRECIPITATION IMPACTS TOO. FIRST...THE DEFORMATION BAND ON THE NORTHWEST SIDE OF THE LOW NOW ONLY LOOKS TO IMPACT THE NORTHWEST HALF OF THE AREA MONDAY AFTERNOON AND NIGHT...THOUGH IT MAY STAY ENTIRELY NORTHWEST OF THE FORECAST AREA. SECOND...A LEAD WAVE OF RAIN RESULTING FROM ISENTROPIC LIFT IS LOOKING LIKELY TO PROGRESS ACROSS THE FORECAST AREA LATE SUNDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THIRD...THE SYSTEMS COLD FRONT AND STRONG DYNAMICS ARE PROGGED TO MOVE THROUGH MONDAY AFTERNOON AND EVENING. THERE IS A CAP TO BE OVERCOME...BUT WITH SUCH STRONG FORCING...CANNOT RULE OUT A BAND OF SHOWERS AND STORMS FIRING ON THE FRONT. SHOULD STORMS FORM...WHICH IS A BIG IF...THERE IS AMPLE SHEAR TO SUPPORT SEVERE. WE WILL NEED TO KEEP AN EYE ON INSTABILITY VERSUS CAPPING FOR MONDAY AFTERNOON. TUESDAY INTO TUESDAY NIGHT LOOK TO BE QUIET AND MUCH COLDER...THEN WEATHER GETS ACTIVE AGAIN FOR WEDNESDAY INTO THURSDAY AS THE REST OF THE UPPER TROUGH LIFTS TOWARDS THE REGION. THIS TIME AROUND...WE MAY HAVE TO DEAL WITH A WINTRY MIX SIDE DUE TO WARM/MOIST ADVECTION ALOFT AND A FLOW OF DRY AIR AND COLD ADVECTION AT THE SURFACE. THEN...IF THE 28.00Z ECMWF IS CORRECT...WE WILL AT LEAST CHANGE OVER TO ALL RAIN AND PERHAPS BRING MORE THUNDERSTORMS. NEEDLESS TO SAY...PLENTY OF UNCERTAINTY OUT THIS FAR AND THUS STAYED WITH A MODEL CONSENSUS FOR NOW. CERTAINLY ANOTHER ITEM TO WATCH. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 646 AM CDT FRI MAR 28 2014 MVFR CONDITIONS THIS MORNING WILL GRADUALLY GIVE WAY TO VFR CONDITIONS LATE THIS MORNING INTO THIS AFTERNOON AS SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. PLAN ON CEILINGS IN THE 1200 TO 2000 FT RANGE THIS MORNING...SCATTERING OUT BY LATE MORNING AND EARLY AFTERNOON. A STORM SYSTEM IS EXPECTED TO TRACK ACROSS THE CENTRAL PLAINS THIS AFTERNOON INTO THE OVERNIGHT HOURS SPREADING MID TO HIGH LEVEL CLOUDS ACROSS THE TAF SITES WITH CLOUD BASES IN THE 10 KFT TO 20 KFT RANGE. && .HYDROLOGY... ISSUED AT 311 AM CDT FRI MAR 28 2014 AREA RIVERS AND STREAMS CONTINUE TO MOSTLY RISE EARLY THIS MORNING FROM THE RECENT RAIN. RAINFALL AMOUNTS AS MUCH AS A LITTLE OVER 1 INCH WERE OBSERVED...HIGHEST OVER THE SOUTHEAST HALF OF THE FORECAST AREA. WITH FROZEN GROUND...MUCH OF THIS RAIN HAS TURNED INTO RUNOFF. SO FAR THE ONLY FLOOD WARNING ISSUED AND VERIFIED WAS ONTARIO...WHILE MOST OTHER RIVERS AND STREAMS ARE STAYING BELOW FLOOD STAGE. EXPECTING MOST SHORT RESPONDING SITES LIKE ONTARIO TO BEGIN FALLING SOON...WHILE LONGER RESPONDING LOCATIONS WILL CLIMB FOR THE NEXT DAY OR SO AS RUNOFF CONTINUES TO FILTER THROUGH. SEE THE LATEST HYDROLOGY RELATED STATEMENTS FOR MORE DETAILS. NEXT HYDROLOGY CONCERN COMES SUNDAY THROUGH MONDAY AS A STRONG SURGE OF WARM AIR COMES INTO THE REGION ON BREEZY SOUTH WINDS. IN ADDITION...RAIN APPEARS LIKELY ON MONDAY. WITH PLENTY OF SNOW STILL PRESENT ALONG/NORTH OF HIGHWAY 10...CONCERN THAT THIS SNOW COULD RAPIDLY MELT...RESULTING IN MORE RISES ON RIVERS SUCH AS THE TREMPEALEAU AND BLACK. WILL ISSUE AN ESF TO COVER THE POTENTIAL FOR FLOODING. SOMEWHAT COOLER AIR FLOWING IN FOR TUESDAY AND WEDNESDAY WILL SLOW THE MELT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...WETENKAMP HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
311 AM CDT FRI MAR 28 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 311 AM CDT FRI MAR 28 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING ALONG THE U.S. WEST COAST INTO BRITISH COLUMBIA...A PACIFIC SHORTWAVE OVER WYOMING...A VIGOROUS PACIFIC SHORTWAVE NEAR DAVENPORT IA...AND A POLAR SHORTWAVE OVER LAKE WINNIPEG. THE DAVENPORT IA SHORTWAVE...IN COMBINATION WITH PRECIPITABLE WATER VALUES OF 0.6-0.9 INCHES / 200 PERCENT OF NORMAL / AND FRONTOGENESIS HELPED PRODUCE PRECIPITATION ACROSS MUCH OF THE FORECAST AREA YESTERDAY TO AROUND MIDNIGHT. MUCH OF THIS PRECIPITATION FELL AS RAIN...WHICH WITH FROZEN GROUND HAS LED TO PLENTY OF RUNOFF AND RISES ON AREA RIVERS AND STREAMS. SEE THE HYDROLOGY SECTION FOR MORE INFORMATION. SOME OF THE PRECIPITATION FELL AS SNOW...MAINLY IN NORTHWEST TO NORTH SECTIONS OF THE AREA...WITH THE MOST IN TAYLOR COUNTY. LOW LEVEL CYCLONIC FLOW AROUND LOW PRESSURE OVER CENTRAL LAKE MICHIGAN HAS KEPT CLOUDS IN PLACE THROUGH THE NIGHT...THOUGH CLEARING WAS EVIDENT OVER THE NORTHWEST HALF OF MINNESOTA. PRECIPITABLE WATER AT BIS WAS QUITE LOW WITH THE RIDGE...0.17 INCHES AT BIS AND ABR OR 50-60 PERCENT OF NORMAL. COLDER AIR WAS ALSO FILTERING IN...REFLECTING A CANADIAN RIDGE OF HIGH PRESSURE BUILDING SOUTH INTO THE UPPER MIDWEST. FARTHER TO THE WEST...CLOUDS AND SOME SCATTERED LIGHT PRECIPITATION WAS OCCURRING OVER WYOMING WITH THE SHORTWAVE THERE. AFTER AN ACTIVE PERIOD OF PRECIPITATION THE PAST 24 HOURS...THIS SHORT TERM PERIOD LOOKS MUCH QUIETER. FOCUS FOR ANY POTENTIAL PRECIPITATION WOULD BE ON THE SHORTWAVE OVER WYOMING...WHICH IS PROGGED BY MODELS TO CROSS THE FORECAST AREA TONIGHT. HOWEVER... THERE ARE 2 ITEMS GOING AGAINST PRECIPITATION... 1. ANOTHER SHORTWAVE COMING OUT OF ARIZONA IS SUGGESTED TO INTENSIFY AND DEEPEN AS IT REACHES MISSOURI TONIGHT...ROBBING THE WYOMING SHORTWAVE OF MOISTURE. 2. THE WYOMING SHORTWAVE WILL BE HEADING INTO A DRY AIRMASS AS SEEN ON THE BIS/ABR SOUNDINGS. MODELS CONTINUE TO DEPICT THAT ANY PRECIPITATION WITH THE SHORTWAVE WILL DRY UP BEFORE THE SHORTWAVE GETS TO THE FORECAST AREA...THUS STAYED WITH A DRY FORECAST. CLOUDS AND TEMPERATURES NOW BECOME THE MAIN CONCERNS. LOW CLOUDS LOOK TO QUICKLY EXIT OFF TO THE EAST THIS MORNING AS THE DRIER AIR TO OUR NORTHWEST ADVECTS IN. SCT-BKN MID AND HIGH CLOUDS WILL THEN TRAVERSE THE AREA THIS AFTERNOON THROUGH TONIGHT AS THE WYOMING SHORTWAVE MOVES THROUGH. 925MB TEMPS ARE PROGGED BETWEEN -2 TO -6C AT 18Z...THOUGH MORE SUN TODAY WILL HELP TO COUNTERACT SOME OF THE COLDER AIR. IN FACT...OVER THE SNOW FREE AREAS...TEMPERATURES MAY EVEN END UP A LITTLE WARMER THAN YESTERDAY. ALTHOUGH SURFACE WINDS LOOK LIGHT TONIGHT...THE CLOUDS SHOULD HELP TO HOLD READINGS UP FROM THE MID TEENS TO MID 20S. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 311 AM CDT FRI MAR 28 2014 MUCH OF THE LONG TERM PERIOD FOCUSES ON AN IMPRESSIVE LONG WAVE TROUGH SITTING OVER THE EASTERN PACIFIC. ALL MODELS SHOW THAT A POTENT SHORTWAVE WILL COME OUT OF THIS TROUGH AND TRACK INTO THE FORECAST AREA FOR MONDAY. THEN THE ENTIRE TROUGH LOOKS TO COME INTO THE WESTERN U.S. ON TUESDAY...TRACKING INTO THE CENTRAL PLAINS ON THURSDAY. MUCH OF FRIDAY NIGHT THROUGH SUNDAY LOOKS TO BE DOMINATED BY BUILDING RIDGING AHEAD OF THE POTENT SHORTWAVE MARCHING ACROSS THE WESTERN U.S.. NO CONCERNS FOR PRECIPITATION DURING THIS PERIOD AS THE FORECAST AREA TRANSITIONS FROM UNDER DOMINANCE OF HIGH PRESSURE TO INTO THE WARM SECTOR OF A DEEPENING SURFACE CYCLONE OVER NORTHEAST COLORADO. TEMPERATURES AND WINDS ARE THE MAIN ISSUES. 925MB TEMPS ARE PROGGED SLIGHTLY WARMER ON SATURDAY...0 TO - 4C...WHICH WITH WHAT LOOKS TO BE PLENTY OF SUN SHOULD HELP BOOST TEMPS INTO THE 40S...PERHAPS EVEN AROUND 50 IN SOME VALLEY LOCATIONS. SOUTH TO SOUTHWEST WINDS REALLY PICK UP SATURDAY NIGHT...UPWARDS OF 40-50 KT BY 12Z SUN AT 925MB...CAUSING 925-850MB TEMPS TO REALLY CLIMB. ANTICIPATING LOWS IN THE EVENING SATURDAY NIGHT...THEN HOLD STEADY TO SLOWLY RISE AS THE WARM AIR SURGES IN. THE CLIMB CONTINUES THROUGH SUNDAY AS THE 925MB TEMPS CLIMB TO AS MUCH AS 10-13C BY 00Z MONDAY. 400-250MB RH PROGS SUGGESTS PLENTY OF SCT-BKN CIRRUS...BUT THE SUN AND WARM 925MB TEMPS SHOULD HELP PROPEL READINGS INTO THE FIRST 60S OF THE YEAR FOR MOST LOCATIONS. MORE SNOWPACK OVER TAYLOR/CLARK WILL HOLD READINGS BACK THERE INTO THE 50S...THOUGH THIS SNOWPACK IS GOING TO MELT FAST GIVEN THE WARM AIR AND BREEZY CONDITIONS...YIELDING HYDRO CONCERNS. SEE HYDROLOGY SECTION. ATTENTION THEN TURNS TO THE POTENT SHORTWAVE HEADING INTO THE FORECAST AREA FOR MONDAY. BOTH THE GFS AND ECMWF HAVE REALLY SLOWED AND DEEPENED THIS SHORTWAVE AND THE ASSOCIATED SURFACE LOW OVER THE PAST 24-48 HOURS. THIS RESULTS IN THE FORECAST AREA STAYING IN THE WARM SECTOR LONGER AND THUS WARMER CONDITIONS ARE FORECAST FOR SUNDAY NIGHT AND MONDAY. THERE ARE A COUPLE OF PRECIPITATION IMPACTS TOO. FIRST...THE DEFORMATION BAND ON THE NORTHWEST SIDE OF THE LOW NOW ONLY LOOKS TO IMPACT THE NORTHWEST HALF OF THE AREA MONDAY AFTERNOON AND NIGHT...THOUGH IT MAY STAY ENTIRELY NORTHWEST OF THE FORECAST AREA. SECOND...A LEAD WAVE OF RAIN RESULTING FROM ISENTROPIC LIFT IS LOOKING LIKELY TO PROGRESS ACROSS THE FORECAST AREA LATE SUNDAY NIGHT THROUGH EARLY MONDAY AFTERNOON. THIRD...THE SYSTEMS COLD FRONT AND STRONG DYNAMICS ARE PROGGED TO MOVE THROUGH MONDAY AFTERNOON AND EVENING. THERE IS A CAP TO BE OVERCOME...BUT WITH SUCH STRONG FORCING...CANNOT RULE OUT A BAND OF SHOWERS AND STORMS FIRING ON THE FRONT. SHOULD STORMS FORM...WHICH IS A BIG IF...THERE IS AMPLE SHEAR TO SUPPORT SEVERE. WE WILL NEED TO KEEP AN EYE ON INSTABILITY VERSUS CAPPING FOR MONDAY AFTERNOON. TUESDAY INTO TUESDAY NIGHT LOOK TO BE QUIET AND MUCH COLDER...THEN WEATHER GETS ACTIVE AGAIN FOR WEDNESDAY INTO THURSDAY AS THE REST OF THE UPPER TROUGH LIFTS TOWARDS THE REGION. THIS TIME AROUND...WE MAY HAVE TO DEAL WITH A WINTRY MIX SIDE DUE TO WARM/MOIST ADVECTION ALOFT AND A FLOW OF DRY AIR AND COLD ADVECTION AT THE SURFACE. THEN...IF THE 28.00Z ECMWF IS CORRECT...WE WILL AT LEAST CHANGE OVER TO ALL RAIN AND PERHAPS BRING MORE THUNDERSTORMS. NEEDLESS TO SAY...PLENTY OF UNCERTAINTY OUT THIS FAR AND THUS STAYED WITH A MODEL CONSENSUS FOR NOW. CERTAINLY ANOTHER ITEM TO WATCH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1159 PM CDT THU MAR 27 2014 MAIN AREA OF PRECIPITATION CONTINUES TO PROGRESS STEADILY EASTWARD AND WILL BE PAST KLSE BY 06Z. HOWEVER...THE LOW CLOUDS AND IFR CEILINGS WILL CONTINUE THROUGH MUCH OF THE NIGHT. OBSERVATIONS INDICATE CEILINGS OF A THOUSAND FEET OR LESS EXTEND BACK INTO WESTERN IOWA WITH MVFR CEILINGS TO THE MISSOURI RIVER. THE 28.00Z NAM CONTINUES TO HAVE A GOOD HANDLE ON THIS MOISTURE AND SHOWS THESE CLOUDS REMAINING THROUGH THE NIGHT AND DISSIPATING UNTIL MID MORNING. GRADIENT IS TIGHT ENOUGH BEHIND THE PASSING SURFACE LOW FOR SOME GUSTY NORTH TO NORTHWEST WINDS THROUGH THE NIGHT AS WELL. THESE WILL ALSO SETTLE DOWN BY MID MORNING. SHORT WAVE TROUGH COMING ACROSS THE NORTHERN ROCKIES IS EXPECTED TO AMPLIFY AND MOVE SOUTH OF THE REGION FRIDAY. THIS SHOULD STILL PASS CLOSE ENOUGH TO PRODUCE MID LEVEL CLOUDS ACROSS THE REGION WITH A VFR CEILING. HIGH PRESSURE WILL DOMINATE AT THE SURFACE WITH ANY PRECIPITATION FROM THE WAVE STAYING WELL TO THE SOUTH OF THE AREA. && .HYDROLOGY... ISSUED AT 311 AM CDT FRI MAR 28 2014 AREA RIVERS AND STREAMS CONTINUE TO MOSTLY RISE EARLY THIS MORNING FROM THE RECENT RAIN. RAINFALL AMOUNTS AS MUCH AS A LITTLE OVER 1 INCH WERE OBSERVED...HIGHEST OVER THE SOUTHEAST HALF OF THE FORECAST AREA. WITH FROZEN GROUND...MUCH OF THIS RAIN HAS TURNED INTO RUNOFF. SO FAR THE ONLY FLOOD WARNING ISSUED AND VERIFIED WAS ONTARIO...WHILE MOST OTHER RIVERS AND STREAMS ARE STAYING BELOW FLOOD STAGE. EXPECTING MOST SHORT RESPONDING SITES LIKE ONTARIO TO BEGIN FALLING SOON...WHILE LONGER RESPONDING LOCATIONS WILL CLIMB FOR THE NEXT DAY OR SO AS RUNOFF CONTINUES TO FILTER THROUGH. SEE THE LATEST HYDROLOGY RELATED STATEMENTS FOR MORE DETAILS. NEXT HYDROLOGY CONCERN COMES SUNDAY THROUGH MONDAY AS A STRONG SURGE OF WARM AIR COMES INTO THE REGION ON BREEZY SOUTH WINDS. IN ADDITION...RAIN APPEARS LIKELY ON MONDAY. WITH PLENTY OF SNOW STILL PRESENT ALONG/NORTH OF HIGHWAY 10...CONCERN THAT THIS SNOW COULD RAPIDLY MELT...RESULTING IN MORE RISES ON RIVERS SUCH AS THE TREMPEALEAU AND BLACK. WILL ISSUE AN ESF TO COVER THE POTENTIAL FOR FLOODING. SOMEWHAT COOLER AIR FLOWING IN FOR TUESDAY AND WEDNESDAY WILL SLOW THE MELT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...04 HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1159 PM CDT THU MAR 27 2014 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 355 PM CDT THU MAR 27 2014 AT 3 PM...A 992 MB SURFACE LOW WAS CENTERED OF THE SOUTHWEST CORNER OF IOWA. THE LATEST MSAS SHOWS 3 HOUR HEIGHT FALLS OF 3 MILLIBARS ACROSS EASTERN IOWA...SOUTHERN WISCONSIN...AND NORTHERN ILLINOIS. AS RESULT...EXPECT THE LOW TO CONTINUE TO TRACK NORTHEAST ACROSS IOWA LATE THIS AFTERNOON AND EARLY EARLY EVENING. MODERATE TO STRONG 850 MB MOISTURE TRANSPORT MOVES INTO NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN BETWEEN 27.21Z AND 28.03Z. DUE TO THIS...INCREASED THE PRECIPITATION TOTALS INTO THE 0.35 TO 0.75 INCH RANGE. IN ADDITION TO THIS...THE MOST UNSTABLE CAPES CLIMB UP TO 300 J/KG ACROSS PARTS OF NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND SOUTHWEST AND CENTRAL WISCONSIN. THERE HAS ALREADY BEEN A FEW ISOLATED REPORTS OF LIGHTNING ALONG AND SOUTH OF INTERSTATE 90 THIS AFTERNOON. WITH THE CAPES A BIT FURTHER NORTH AND WEST...EXPANDED THE CHANCE OF THUNDERSTORMS MORE INTO NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND AS FAR AS NORTH OF INTERSTATE 90 CORRIDOR THROUGH 28.03Z. WITH THE 0-3 KM AND 0-6 KM SHEAR LESS THAN 30 KNOTS...NOT EXPECTING ANYTHING SEVERE. MEANWHILE ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN...COLD AIR ADVECTION DEVELOPS ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN. THE NAM IS THE STRONGEST AND FASTEST WITH THIS COLD AIR ADVECTION. AS A RESULT...IT PRODUCES MUCH MORE SNOW ACROSS SOUTHEAST MINNESOTA /UP TO 2.5 INCHES IN COBB/ TONIGHT. HOWEVER THE 18Z AMDAR SOUNDINGS SHOW THAT IT IS A BIT TOO COLD AND MUCH CLOSER TO THE RAP AND GFS. AS A RESULT...TRENDED THE SWITCH OVER FROM RAIN TO SNOW A BIT LATER THAN PREVIOUSLY FORECAST. IT LOOKS LIKE THIS WILL OCCUR...NORTH OF INTERSTATE 94 BETWEEN 27.21Z AND 28.00Z...WEST OF MISSISSIPPI RIVER BETWEEN 28.00Z AND 28.03Z...AND ACROSS THE REMAINDER OF THE AREA BETWEEN 28.04Z AND 28.08Z. SOUTHEAST MINNESOTA WILL SEE UP TO AN INCH...AND AROUND 3 INCHES NORTH OF WISCONSIN 29 IN NORTH CENTRAL WISCONSIN. ELSEWHERE VERY LITTLE...IF ANY...SNOW IS EXPECTED. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 355 PM CDT THU MAR 27 2014 ON SUNDAY...A TIGHT PRESSURE GRADIENT DEVELOPS ALONG AND SOUTH OF THE INTERSTATE 90 CORRIDOR AHEAD OF A DEEPENING LOW OVER THE NORTHERN PLAINS. THIS TIGHT PRESSURE GRADIENT WILL ALLOW THE SUSTAINED SOUTH WINDS TO CLIMB INTO THE 15 TO 25 KNOT RANGE AND THE WINDS WILL GUST UP TO 35 MPH. AT THE SAME...THE 850 MB TEMPERATURES WILL CLIMB INTO THE 10 TO 14C RANGE ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. BUFKIT SOUNDING SHOW THAT WE WILL NOT QUITE MIX UP TO THIS LEVEL...BUT WE WILL MIX UP INTO THE 900 TO 875 MB LAYER...AND THIS WILL ALLOW TEMPERATURES TO CLIMB INTO THE LOW AND MID 50S NORTH OF INTERSTATE 94...AND AROUND 60 ACROSS THE REMAINDER OF THE AREA. FROM SUNDAY NIGHT INTO MONDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT A NEGATIVELY TILTED SHORT WAVE TROUGH WILL MOVE THROUGH THE FORECAST AREA. TEMPERATURES ALOFT ARE WARM ENOUGH THAT MUCH OF THE PRECIPITATION WILL FALL MAINLY IN THE FORM OF RAIN. WHILE THE 0-6 KM SHEAR ARE GREATER THAN 35 KNOTS...THERE IS VERY LITTLE CAPE ACROSS THE REGION...SO THERE IS NOT ANY THREAT FOR ANY SEVERE WEATHER. BEYOND THIS TIME PERIOD...THE 27.00Z MODELS HAVE DIFFERING OPINIONS ON HOW FAR NORTH A LOW WILL TRACK THROUGH NORTHERN AND MID MISSISSIPPI RIVER VALLEY. THE ECMWF IS MUCH FURTHER NORTH THAN THE GFS. WITH SUCH DIVERSE SOLUTIONS...JUST STAYED WITH THE MODEL CONSENSUS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1159 PM CDT THU MAR 27 2014 MAIN AREA OF PRECIPITATION CONTINUES TO PROGRESS STEADILY EASTWARD AND WILL BE PAST KLSE BY 06Z. HOWEVER...THE LOW CLOUDS AND IFR CEILINGS WILL CONTINUE THROUGH MUCH OF THE NIGHT. OBSERVATIONS INDICATE CEILINGS OF A THOUSAND FEET OR LESS EXTEND BACK INTO WESTERN IOWA WITH MVFR CEILINGS TO THE MISSOURI RIVER. THE 28.00Z NAM CONTINUES TO HAVE A GOOD HANDLE ON THIS MOISTURE AND SHOWS THESE CLOUDS REMAINING THROUGH THE NIGHT AND DISSIPATING UNTIL MID MORNING. GRADIENT IS TIGHT ENOUGH BEHIND THE PASSING SURFACE LOW FOR SOME GUSTY NORTH TO NORTHWEST WINDS THROUGH THE NIGHT AS WELL. THESE WILL ALSO SETTLE DOWN BY MID MORNING. SHORT WAVE TROUGH COMING ACROSS THE NORTHERN ROCKIES IS EXPECTED TO AMPLIFY AND MOVE SOUTH OF THE REGION FRIDAY. THIS SHOULD STILL PASS CLOSE ENOUGH TO PRODUCE MID LEVEL CLOUDS ACROSS THE REGION WITH A VFR CEILING. HIGH PRESSURE WILL DOMINATE AT THE SURFACE WITH ANY PRECIPITATION FROM THE WAVE STAYING WELL TO THE SOUTH OF THE AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...04
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
922 PM PDT SAT MAR 29 2014 .UPDATE... RADAR TRENDS OVER THE LAST COUPLE HOURS ARE SHOWING MAIN PRECIP BAND SLIDING SLOWLY TO THE SOUTH. BASED ON LATEST HRRR GUIDANCE WHICH HAS A REASONABLE GRASP OF THE SITUATION, SNOW RATES SHOULD DIMINISH FOR THE TAHOE BASIN AND NORTH OF I-80 AFTER ABOUT 6-7Z, WITH HEAVY SNOWS CONTINUING IN MONO CO UNTIL ABOUT DAYBREAK SUNDAY. THIS IS ALL CONSISTENT WITH ONGOING FORECAST AND WARNINGS, SO NO CHANGES PLANNED. I DID CONSIDER DROPPING WINTER WEATHER ADVISORY FOR CAZ071 (NORTH OF I-80) BUT SNOW SHOWERS WILL LIKELY CONTINUE INTO THE OVERNIGHT HOURS BASED ON GUIDANCE AND RADAR TRENDS. THOSE COULD PUT DOWN SOME QUICK ACCUMULATIONS AND IMPACT ROADWAYS. SPILLOVER INTO THE RENO/CARSON CITY AREAS HAS BEEN A STRUGGLE THUS FAR, BUT WE`RE NOW GETTING LIGHT TO MODERATE RAIN/SNOW SHOWERS INCREASING IN COVERAGE. THIS SHOULD CONTINUE INTO THE OVERNIGHT HOURS. LOWERING SNOW LEVELS MAY YIELD LIGHT ACCUMULATIONS IN THE FOOTHILL AREAS AT/ABOVE 5000 FT TONIGHT. CS && .PREVIOUS DISCUSSION... /ISSUED 308 PM PDT SAT MAR 29 2014/ SYNOPSIS... RAIN AND SNOW WILL CONTINUE THROUGH TONIGHT AS A LATE SEASON WINTER STORM MOVES ACROSS THE SIERRA. A COLDER STORM SYSTEM WILL IMPACT THE REGION MONDAY AND TUESDAY WITH LIGHT SNOW POSSIBLE IN LOWER ELEVATIONS. BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH MUCH OF THE UPCOMING WEEK, WITH ANOTHER CHANCE OF RAIN AND SNOW SHOWERS THURSDAY AND FRIDAY. SHORT TERM... PRECIPITATION CONTINUES TO INTENSIFY NEAR AND WEST OF THE SIERRA CREST AS MAIN TROUGH APPROACHES THE CALIFORNIA COAST. UPPER LEVEL JET WILL ALSO MOVE ONSHORE AND ENHANCE THE MOISTURE BAND. SNOW LEVELS EAST OF THE SIERRA CREST NEAR TAHOE HAVE REMAINED NEAR 6500-7000 FEET BUT SHOULD DROP TO LAKE LEVEL BEFORE 5 PM. SNOWFALL RATES OF 1-2 INCHES PER HOUR ARE LIKELY TO PERSIST A PERIOD OF 6-8 HOURS, AND TRAVEL IMPACTS WILL INCREASE THIS EVENING AS SNOW BEGINS ACCUMULATING ON PAVED SURFACES. THEREFORE THE WARNING WILL REMAIN IN PLACE. FARTHER NORTH INTO LASSEN COUNTY, ALTHOUGH SOME SNOW HAS ALREADY ACCUMULATED ABOVE 5500 FEET, THE HEAVIER SNOW IS ALSO EXPECTED TO END SOONER, SO THE ADVISORY SHOULD BE SUFFICIENT. LOCALIZED SNOW SHOWER BANDS MAY CONTINUE LATER TONIGHT, DEPENDING ON HOW MUCH CONVECTIVE ACTIVITY DEVELOPS IN NORTH CENTRAL CA DURING THE NEXT FEW HOURS. FOR MONO COUNTY, SNOW WILL INCREASE THIS EVENING, SPREADING SOUTHWARD ALONG THE SIERRA AND PROBABLY REACHING THE MAMMOTH LAKES VICINITY BY 8 PM. BEFORE THE SNOW ARRIVES, WINDY CONDITIONS WILL CONTINUE, SO THE ADVISORY WILL BE EXTENDED FOR A FEW MORE HOURS. SINCE ALL OF THE SNOW WILL FALL IN A COMPRESSED TIME PERIOD AND THE BAND WILL BEGIN TO WEAKEN LATE TONIGHT, SNOW TOTALS NEAR THE CREST MAY TOP OUT CLOSER TO 16 INCHES INSTEAD OF THE ORIGINAL 20 INCH PROJECTION. HOWEVER, IMPACTS WILL STILL BE SUFFICIENT TO KEEP THE WARNING IN PLACE TONIGHT. FOR WESTERN NV, THE RAIN SHADOW HAS PERSISTED SO FAR THIS AFTERNOON. HOWEVER, THE LAST FEW RUNS OF THE HRRR MODEL HAVE INDICATED RAPID SPILLOVER INTO THE RENO-CARSON VICINITY BETWEEN 4 AND 5 PM, WITH UP TO 6 HOURS OF NEARLY STEADY RAIN THROUGH THIS EVENING. IF THIS OCCURS, RAINFALL COULD STILL ADD UP TO BETWEEN 0.25 AND 0.50 INCH, WITH LOCALLY HIGHER AMOUNTS IN FOOTHILL LOCATIONS. FOR AREAS SOUTH OF HIGHWAY 50, THE MAJORITY OF THE RAIN WILL FALL DURING THE LATE EVENING AND OVERNIGHT HOURS. THE PRECIP COULD END AS SNOW BELOW 5000 FEET, BUT LITTLE OR NO SNOW ACCUMULATION IS EXPECTED IN VALLEYS. ABOVE 5000 FEET, A COUPLE INCHES MAY ACCUMULATE, BUT SOME LOCALLY HIGHER AMOUNTS MAY FALL IN DOUGLAS COUNTY AS THE COLD AIR ARRIVES IN CONJUNCTION WITH THE ONGOING HEAVIER PRECIP BAND. THIS OCCURRED WITH ONE OF THE STORMS EARLIER THIS SEASON SO THIS WOULD NEED TO BE MONITORED LATER TONIGHT. ALL GUIDANCE IS IN AGREEMENT FOR A RAPID DISSIPATION OF THE RAIN AND SNOW BY EARLY SUNDAY MORNING. FOR SUNDAY, A FEW SHOWERS MAY LINGER NEAR THE SIERRA AND IN WEST CENTRAL NV EAST OF HIGHWAY 95, OTHERWISE MOSTLY CLOUDY AND DRY CONDITIONS WILL PREVAIL WITH MODERATE WEST WINDS GUSTING TO 20-30 MPH IN THE AFTERNOON. MJD A COLDER LOW PRESSURE WILL DROP ALONG THE WEST COAST EARLY NEXT WEEK, BRINGING ADDITIONAL PRECIPITATION TO THE SIERRA AND WESTERN NEVADA. THIS LOW WILL BRING VERY COLD AIR DOWN FROM THE GULF OF ALASKA WITH 700MB NEAR -10C. SNOW LEVELS WILL FALL TO MOST VALLEY FLOORS BY MONDAY NIGHT AND INTO TUESDAY MORNING. THAT BEING SAID, THE LATEST MODEL RUNS OF THE GFS AND ECMWF HAVE BACKED OFF ON PRECIPITATION AMOUNTS IN WESTERN NEVADA, LEADING TO CONTINUED UNCERTAINTY AND LOW FORECASTER CONFIDENCE. THIS IS MAINLY BECAUSE THE LOW IS TRYING TO SPLIT OFF TO THE SOUTH AND DRIVE THE JET AND DYNAMICS WELL INTO SOUTHERN CA. THE HIGHEST CHANCES FOR SNOW WILL REMAIN IN THE SIERRA LATE MONDAY AS THE FIRST SHORTWAVE MOVES THROUGH NORTHERN CA. THE 500MB SHORTWAVE LOOKS TO BECOME NEGATIVELY TILTED, WHICH IS IS NOT NECESSARILY GOOD FOR SPILLOVER. BUT, WE SHOULD BE UNSTABLE ENOUGH FOR SOME LIGHT SPILLOVER IF THE JET REMAINS SOUTH OF MONO COUNTY. BY TUESDAY, LOW PRESSURE REMAINS OVER THE REGION WITH CONVECTIVE SHOWERS DEVELOPING UNDER THE COLD POOL. INSTABILITY LOOKS FAIRLY STRONG DUE TO THE INCREASED SOLAR HEATING. WE WILL NEED TO KEEP A CLOSE EYE, BECAUSE A SURFACE LOW DEVELOPING OVER SOUTHERN NEVADA MAY CREATE SOME LOW-LEVEL FORCING THAT COULD INCREASE PRECIPITATION RATES IN THE EASTERN SIERRA AND WESTERN NEVADA. HOON LONG TERM...WEDNESDAY THROUGH SATURDAY... FORECAST REMAINS UNCERTAIN FOR THE SYSTEM AT THE END OF NEXT WEEK. DETERMINISTIC SOLUTIONS HAVE LARGELY DIVERGED WITH THE GFS PRESENTING A SPLIT SYSTEM WILL VERY LITTLE PRECIPITATION; THE EC SHOWS A MORE CONSOLIDATED FRONT WITH LOW PRESSURE IN CENTRAL OREGON AND DECENT PRECIP ALONG THE SIERRA. THEREFORE, VERY FEW ADJUSTMENTS TO THE EXISTING FORECAST FAVORING A BLENDED APPROACH WITH 30-40% CHANCE OF PRECIP ALONG THE SIERRA FROM THURSDAY INTO SATURDAY. TEMPERATURES CONTINUE TO LOOK AROUND TO SLIGHTLY COOLER THAN SEASONAL AVERAGES WITH MODEST COLD AIR ALOFT AT 700MB AND AMPLE CLOUD COVER. HOPEFULLY SOLUTIONS WILL BEGIN TO CONVERGE OVER THE NEXT DAY OR SO TO ALLOW FOR HIGHER DETAILS. BOYD AVIATION... A CHANGEOVER TO SNOW IS EXPECTED BY 00Z AROUND THE TAHOE BASIN, WITH ABOUT 6-8 HOURS OF CIGS/VSBY BELOW LANDING MINIMUMS AT KTVL/KTRK THIS EVENING AND INTO THE LATE NIGHT. FOR KMMH, THE WORST CONDITIONS ARE LIKELY FROM 03Z-12Z FROM THIS SAME SNOW BAND. CONDITIONS WILL IMPROVE SUNDAY MORNING ALTHOUGH SOME MVFR CIGS COULD LINGER THROUGH MUCH OF THE DAY AS RESIDUAL MOISTURE REMAINS IN PLACE. FOR WESTERN NV INCLUDING KRNO-KCXP, RAIN WILL INCREASE AROUND 00Z, PRODUCING MVFR CIGS/VSBY AT TIMES FOR 4-6 HOURS THIS EVENING. THIS PRECIP MAY BRIEFLY END AS SNOW, BUT LITTLE OR NO SNOW ACCUMULATION IS EXPECTED ON RUNWAYS. VFR CONDITIONS ARE EXPECTED SUNDAY ALTHOUGH SOME MOUNTAIN OBSCURATIONS WILL REMAIN POSSIBLE DUE TO RESIDUAL CLOUD COVER. MJD && .REV WATCHES/WARNINGS/ADVISORIES... NV...WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY NVZ002. CA...WINTER WEATHER ADVISORY UNTIL 5 AM PDT SUNDAY ABOVE 5500 FEET FOR CAZ071. WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY CAZ073. WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY CAZ072. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS NEW YORK NY
219 AM EDT SUN MAR 30 2014 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES MOVES VERY SLOWLY EAST THIS MORNING AS A WARM FRONT WORKS ONSHORE ACROSS LONG ISLAND. THE LOW EMERGES OFF THE MID ATLANTIC AFTER DAYBREAK AND THEN TRACKS VERY SLOWLY TO THE EAST THROUGH MONDAY. THEREAFTER...HIGH PRESSURE BUILDS INTO THE AREA THROUGH TUE AS A WEAK COLD FRONT APPROACHES FROM THE WEST. THIS FRONT WILL MOVE THROUGH THE AREA TUESDAY NIGHT FOLLOWED BY HIGH PRESSURE NOSING IN FROM THE NORTH INTO THURSDAY. A FRONTAL SYSTEM IS EXPECTED TO IMPACT THE AREA AT THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... A STRONG LOW-LEVEL JET INTERSECTING A COASTAL FRONT AND FALLING HEIGHTS ALOFT RESULTING IN CONVECTION WITH SHOWERS AND EVEN AN ISOLATED THUNDERSTORMS. BEST LIFT EAST OF NYC WITH THE POTENTIAL FOR ANOTHER HALF INCH TO INCH OF RAINFALL ACROSS LI AND CT. THIS WILL BE ON TOP OF THE TWO INCHES MOST LOCATIONS HAVE ALREADY RECEIVED. LATEST HRRR INDICATES CONVECTION JUST EAST OF THE DELMARVA AND NJ WORKS NORTH OVER THE NEXT SEVERAL HOURS. SEVERAL RIVER LOCATIONS ACROSS NE NJ ARE AT OR JUST OVER BANK FULL. THIS IS BEING HANDLED WITH URBAN AND SMALL STREAM FLOOD ADVISORIES. WILL HAVE TO WATCH CONVECTION ACROSS EASTERN VA/MD AS IT WORK NORTH...BUT FOR THE TIME THERE WILL BE A BREAK WHICH SHOULD ALLOW LEVELS TO CREST AND BEGIN FALL. FLOOD WATCH REMAINS IN EFFECT. LOWS FOR TONIGHT WERE A BLEND OF NAM12...MET...AND MAV GUIDANCE AND INCREASED BY TWO DEGREES...WITHOUT MUCH DIURNAL TEMPERATURE RANGE ANTICIPATED...RANGING FROM THE UPPER 30S TO MID 40S. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... LIKELY POPS CONTINUE DURING SUN MORNING AS LULL IN THE PCPN IS EXPECTED UNTIL THE DEFORMATION BAND MOVES INTO THE AREA. OCNL RAIN IS EXPECTED TO RETURN WITH A COASTAL FRONT DRAPED ACROSS THE REGION WITH PERHAPS SOME FRONTOGENETICAL FORCING COMING INTO PLAY DURING THE MID TO LATE MORNING HOURS. AS THE SURFACE LOW ALONG WITH THE UPPER LEVEL LOW SLOWLY TRACKS TO SOUTH OF LONG ISLAND THE AREA WILL GET MORE OF A NORTHERLY SURFACE FLOW...WITH A GRADUAL DECREASE IN PRECIPITABLE WATER THROUGHOUT THE DAY. MODELS CONVEY A DECREASE TO AROUND 1 INCH PRECIPITABLE WATER BY EARLY AFTERNOON AND THEN TOWARDS 0.7-0.8 INCH BY SUNDAY EVENING. MID LEVELS DRY...ALTHOUGH DEPTH OF SATURATED LAYER APPEARS TO BE SUFFICIENT ENOUGH FOR LIGHT RAIN AS OPPOSED TO DZ UNTIL LATE AFTN. HIGHS WERE TAKEN FROM THE GMOS...MET...AND MAV GUIDANCE WITH GREATER WEIGHT WITH THE GMOS AND ARE FORECAST TO BE IN THE UPPER 40S TO NEAR 50. ANOTHER AREA OF RAIN WILL MOVE IN LATE SUNDAY AFTERNOON INTO SUNDAY EVENING FOR THE SECOND ROUND ASSOCIATED WITH THE DEFORMATION ZONE NORTHWEST OF THE LOW...BUT THIS WILL BE LIGHTER THAN THE FIRST ROUND. LATE SUNDAY NIGHT INTO MONDAY MORNING WITH THE COLD AIR ADVECTION...THERE COULD BE SOME WINTRY MIX OF SLEET AND/OR FREEZING RAIN NORTH AND WEST OF NYC...BUT THERE IS HIGHER UNCERTAINTY WITH THIS. THIS DEPENDS ON HOW FAST COLDER AIR ADVECTS IN. LOWS WERE A BLEND OF NAM12/GMOS/MET/MAV AND ARE FORECAST TO BE MID TO UPPER 30S MOST LOCATIONS AND LOWER 30S FOR SOME LOCATIONS...PARTICULARLY HIGHER TERRAIN NORTH AND WEST OF NYC. THE AREA WILL FINALLY BE ON THE WESTERN SIDE OF THE UPPER LEVEL TROUGH MONDAY WHICH WILL REALLY DECREASE THE SYNOPTIC FORCING WITH A RIDGING TREND LATER IN THE DAY. THE PRECIPITABLE WATERS WILL CONTINUE TO LOWER. THESE VALUES WILL BE AROUND 0.5 INCH MONDAY AFTERNOON INTO MONDAY EVENING. RAIN WILL BE PRETTY LIGHT WITH DAYTIME TEMPERATURES INCREASING ENOUGH TO ALLOW FOR ANY WINTRY MIX NORTH AND WEST OF NYC TO CHANGE BACK TO RAIN. THIS TAPERS OFF FROM WEST TO EAST LATE IN THE DAY. HIGH TEMPERATURES ARE FORECAST TO BE IN THE UPPER 40S TO NEAR 50 AND USED THE ECS MOS. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN THROUGH THE MIDDLE OF THE WEEK...THEN BEGIN TO GO AWRY WITH THE AMPLITUDE OF THE TROUGH EXITING THE ROCKIES EXPECTED TO IMPACT THE LOCAL AREA AT THE END OF THE WEEK. DEEP LAYERED RIDGING BUILDS IN THE WAKE OF THE CUTOFF WITH THE AXIS SLIDING ACROSS THE AREA ON TUE. A WEAK COLD FRONT CROSSES THE AREA LATE TUE NIGHT AND IS FORECAST TO WASH OUT OVER THE AREA ON WED AS A SHORTWAVE TROUGH PASSES TO THE NORTH. A BROAD RIDGE THEN DEVELOPS OVER THE EASTERN US AS A TROUGH DIGS OVER THE WEST. UNCERTAINTY IN THE UPPER FLOW TAKES SHAPE AS THE TROUGH EXITS THE ROCKIES. THIS SYSTEM WILL BE THE NEXT WEATHER MAKER FOR THE LOCAL AREA AT THE END OF THE WEEK. TEMPERATURES WILL BE AT OR ABOVE NORMAL LEVELS THROUGH THE PERIOD. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... LOW PRES TRACKS OFF THE NJ COAST THIS AFTN...THEN SLOWLY DRIFTS E OF THE REGION THRU MON. IFR OR LOWER THRU AT LEAST 10Z MON. HIGHEST POTENTIAL FOR LIFR THRU 12-14Z SUN. THE HEAVIEST RAIN WILL OCCUR IN THE NEAR TERM...HOWEVER VSBY WILL REMAIN RESTRICTED THRU THE TAF PERIOD BY -RA AND BR. ISOLD TSTMS POSSIBLE THRU AROUND 8Z. WIND SPEEDS WILL DECREASE THRU 12Z...THEN INCREASE AFT 00Z AS THEY BACK TO THE N. THE STRONG N WINDS WILL PERSIST THRU MON. .OUTLOOK FOR 06Z MONDAY THROUGH WEDNESDAY... .SUN NIGHT...IFR LIKELY. N WINDS 20-30 KT. .MON...MVFR OR LOWER...MAINLY IN THE MRNG. N WINDS 20-30 KT. .TUE-WED NIGHT...MAINLY VFR. .THU...SUB-VFR POSSIBLE IN SHOWERS. && .MARINE... SEAS WILL CONTINUE TO INCREASE WITH EASTERLY FETCH AHEAD OF DEVELOPING SURFACE LOW THROUGH THIS EVENING. MORE SOUTHEAST FLOW TONIGHT IN RESPONSE TO WARM FRONT SHIFTING SLIGHTLY NORTH WILL KEEP THE HIGHER SEAS. SCA GUSTS WILL DEVELOP LATE TONIGHT AS WELL. A LITTLE LULL IN WINDS SUNDAY MORNING BUT HIGHER WINDS WILL RETURN SUNDAY AFTERNOON AND THROUGH SUNDAY NIGHT WITH A STRENGTHENING NORTHERLY FLOW AND COLD AIR ADVECTION ON THE BACKSIDE OF THE SURFACE LOW. SCA WILL REMAIN ON THE OCEAN THROUGH SUNDAY NIGHT BUT WILL BECOME PRESENT ON OTHER WATERS AS WELL SUNDAY AFTERNOON AND SUNDAY NIGHT. THE SCA CONDITIONS CONTINUE INTO MONDAY AS WELL. THERE WILL BE THE POSSIBILITY OF GALES ON THE EASTERN OCEAN WATERS FOR LATE SUNDAY NIGHT THROUGH MONDAY BUT CONFIDENCE IS LESS THAN 50 PERCENT. WINDS WILL BE DIMINISHING MON NIGHT...BUT WILL LIKELY REMAIN ABOVE SCA LEVELS...MAINLY ON THE OCEAN WATERS...THROUGH MON NIGHT. SCA SEAS ON THE EASTERN OCEAN WATERS WILL LIKELY LINGER INTO TUE MORNING. TRANQUIL CONDS RETURN THEREAFTER WITH A WEAK PRES GRADIENT OVER THE AREA. && .HYDROLOGY... AN AVERAGE OF 2 TO 2 1/2 INCHES OF RAIN HAS FALLEN THROUGH EARLY THIS MORNING. AN ADDITIONAL HALF TO ONE INCH OF RAINFALL IS POSSIBLE THROUGH DAYBREAK ACROSS LI AND SRN CT AS CONVECTION WORKS IN FROM THE SOUTH. MINOR URBAN AND POOR DRAINAGE FLOODING WILL CONTINUE. THERE IS SOME UNCERTAINTY WITH ADDITIONAL RAINFALL SUN NIGHT AS A BAND OF MODERATE TO HEAVY RAINFALL FORMS TO THE NW OF THE LOW TRACK. THE MAIN IMPACT AT THIS TIME LOOKS TO BE ACROSS NE NJ AND THE LOWER HUDSON VALLEY. A FLOOD WATCH REMAINS IN PLACE FOR THE LOWER HUDSON VALLEY...NE NJ...AND SOUTHERN CT. && .TIDES/COASTAL FLOODING... DUE TO HIGH ASTRONOMICAL TIDES WITH A NEW MOON...THERE IS THE POSSIBILITY OF LOCALIZED MINOR COASTAL FLOODING NEAR THE TIME OF HIGH TIDE FOR THE NEXT SEVERAL HIGH TIDE CYCLES. THE BEST CHANCE FOR THIS WILL BE FOR LOCATIONS ALONG THE COAST OF WESTERN LONG ISLAND SOUND. IN ADDITION TO THE WESTERN PORTION OF THE LONG ISLAND SOUND...THE SOUTH SHORE BACK BAYS OF LONG ISLAND MAY BE SUSCEPTIBLE DURING HIGH TIDES SUNDAY...PARTICULARLY SUNDAY NIGHT. THE THREAT APPEARS TO BE LOCALIZED. && .EQUIPMENT... THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY METROPOLITAN AREA IS CURRENTLY BROADCASTING. THE TRANSMITTER IS CURRENTLY BEING TESTED TO DETERMINE IF RADIO FREQUENCY INTERFERENCE CONTINUES ON THE U.S. COAST GUARD CHANNEL 16 TRANSMITTER FOR INTERNATIONAL DISTRESS...SAFETY AND RESCUE. FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION STATEMENT (ALL LOWER CASE): WWW.WEATHER.GOV/OKX/NYCNWRUPDATE && .OKX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH THROUGH LATE TONIGHT FOR CTZ005>012. NY...FLOOD WATCH THROUGH LATE TONIGHT FOR NYZ067>071. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ002-004-103>108. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR ANZ330-335. SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ350-353-355. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
109 AM CDT SUN MAR 30 2014 .DISCUSSION... 321 PM CDT MAIN FORECAST CONCERNS/CHALLENGES ARE WITH SHOWER/THUNDER CHANCES MONDAY AND MONDAY NIGHT...AND THEN WITH ACTIVE WEATHER TO CONTINUE THROUGH LATE IN THE WORK WEEK. CHALLENGES IN THE NEAR TERM HAVE BEEN WITH THE LINGERING AND SLOW MOVING LOW STRATUS STILL IN PLACE OVER MUCH OF THE CWA...AS WELL AS RESULTANT HIGH TEMPERATURES. LATEST VISIBLE SATELLITE IMAGERY DEPICTING A SLOW SOUTH/SOUTHEAST MOVEMENT TO THE STRATUS BUT WITH SOME PROGRESS BEING MADE. ALTHOUGH...THIS PROGRESS IS SLOW AND COINCIDING WITH FURTHER DIURNAL DEVELOPMENT ON THE NORTHERN PERIPHERY OF THIS CLOUD DECK. MADE EDITS THIS AFTERNOON TO SLOW THE CLEARING TREND THROUGH 00Z AND WITH AT LEAST PARTLY CLOUDY SKIES FOR THE SOUTHERN THIRD OF THE CWA THROUGH EARLY THIS EVENING...BEFORE CLEARING CONTINUES AND MOSTLY CLEAR SKIES EXPECTED TO PREVAIL OVERNIGHT. DID DROP HIGH TEMPS A COUPLE OF DEGREES IN SOME PLACES EARLIER THIS AFTERNOON DUE TO THIS CLOUD COVER...WITH TEMPS STAYING IN THE UPPER 30S OR AROUND 40 UNDER THE CLOUD COVER AND LOW TO MID 40S FOR AREAS WHICH HAVE OBSERVED MORE SUNSHINE WITHIN THE LAST COUPLE OF HOURS. ALTHOUGH...ALL LOCATIONS WILL OBSERVE FALLING TEMPS THIS EVENING AS THE DEPARTING CLOUD COVER THIS AFTERNOON AND EVENING ONLY AIDS IN A COLD NIGHT TONIGHT. SURFACE HIGH TO THE WEST/NORTHWEST WILL SHIFT OVERHEAD TONIGHT WITH WINDS DIMINISHING AND DESPITE WAA BEGINNING OVERNIGHT...TEMPS ANTICIPATED TO FALL INTO THE 20S ACROSS THE CWA. MID/UPPER 20S ARE LIKELY FOR MOST LOCATIONS...OUTSIDE OF THE CITY...WITH SOME LOCATIONS POSSIBLE DIPPING INTO THE LOWER 20S. QUIET CONDITIONS EXPECTED SUNDAY/SUNDAY NIGHT AS UPPER LEVEL RIDGING IS ONGOING ACROSS THE REGION. CONTINUED WAA WILL HELP A WARMER AIRMASS TO SPREAD OVER THE CWA ON SUNDAY WITH TEMPS EXPECTED TO RISE AROUND 60. DID MAKE SOME MINOR ADJUSTMENTS TO MAX TEMPS MAINLY TO ACCOUNT FOR PERSISTENT ONSHORE FLOW FOR AREAS IN CHICAGO AND NORTHWARD...KEEPING TEMPS IN THE LOW TO MID 50S. AFTER A MILD NIGHT SUNDAY NIGHT...PERSISTENT WAA WILL PROVIDE WELL ABOVE NORMAL HIGHS IN THE MID TO UPPER 60S. ONSHORE FLOW NOT ANTICIPATED SO MOST LOCATIONS LIKELY TO OBSERVE THIS WARMTH. WILL HAVE INCREASING CLOUD COVER ON MONDAY IN ADVANCE OF VORT MAX AND ATTENDANT SURFACE LOW MOVING EAST OVER THE CENTRAL CONUS. GUIDANCE IN AGREEMENT WITH DRY CONDITIONS MONDAY MORNING AND THEN WITH INCREASING CHANCES FOR PRECIP INTO THE AFTERNOON...THOUGH PRIMARILY FOR THE WESTERN CWA. FOR MONDAY AFTERNOON INTO MONDAY EVENING...NOT OVERLY CONFIDENT WITH POPS DURING THIS PERIOD AND HAVE ONLY MADE MINOR CHANGES TO LOW CHANCE/CHANCE POPS. THIS IS MAINLY DUE TO THE FACT THAT CONFIDENCE IS NOT HIGH WITH REGARDS TO OVERALL COVERAGE OF PRECIP. WITH LARGE SCALE FORCING FOR ASCENT SPREADING OVER THE AREA ON MONDAY AS WELL AS MOISTURE INCREASING OUT AHEAD OF SURFACE LOW AND COLD FRONT...DEVELOPMENT SHOULD NOT BE TOO MUCH OF AN ISSUE...AND EXPECT POPS TO LIKELY CHANGE DURING THIS PERIOD WITH SUCCESSIVE FORECASTS. STILL NOT OVERLY CONFIDENT WITH THUNDER DEVELOPMENT AS WELL...AND SO HAVE MADE LITTLE CHANGES DURING THIS TIME KEEPING CHANCE THUNDER IN THE GRIDS. WILL NEED TO MONITOR THE EXTENT OF THE MOISTURE RETURN AND RESULTANT INSTABILITY...WHICH AT THIS TIME IS APPEARING RATHER WEAK. WILL STILL NEED TO MONITOR AN EXPECTED ACTIVE WEATHER PATTERN FOR THIS NEXT WEEK AS GUIDANCE IS IN AGREEMENT WITH SEVERAL FEATURES PUSHING ACROSS THE REGION. ALTHOUGH...TIMING AND EVOLUTION AGREEMENT IS LACKING WHICH WILL BE KEY WITH PRECIP TYPE...WHICH COULD STILL BE OF FROZEN FORM VERY LATE IN THE FORECAST PERIOD. RODRIGUEZ && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * WINDS CALM OR LIGHT AND VARIABLE THROUGH SUNRISE...THEN SOUTHEAST TO SOUTH MOST OF THE DAY. * LLWS POSSIBLE SUNDAY NIGHT. LENNING //DISCUSSION...UPDATED 06Z... SKIES HAVE CLEARED AND WINDS HAVE GONE CALM UNDER A RIDGE PASSING OVERHEAD EARLY THIS MORNING. SO FAR VSBYS HAVE STAYED UP AS A RESULT OF DECENT SPREADS BETWEEN TEMPERATURES AND DEWPOINTS. THE PREFERRED WIND DIRECTION WILL BE SOUTHEASTERLY AS THE RIDGE MOVES OUT LATER THIS MORNING. MORE OF A SOUTHERLY COMPONENT DEVELOPS BY THE AFTERNOON AHEAD OF THE NEXT LOW PRESSURE SYSTEM...BUT WINDS APPEAR TO REMAIN ON THE EAST SIDE OF SOUTH AND DO NOT DEVELOP A WESTERLY COMPONENT. AGREE WITH EARLIER THINKING REGARDING LACK OF AN EASTERLY LAKE BREEZE AT TERMINALS THIS AFTERNOON DESPITE SOME COOL ONSHORE COMPONENT BETWEEN THE TERMINALS AND THE WATERFRONT. AN INCREASING PRESSURE GRADIENT WILL SUPPORT STRENGTHENING SOUTHERLY FLOW TONIGHT INTO MONDAY. SURFACE WINDS LIKELY WILL NOT INCREASE OVERNIGHT WITH A COOL SURFACE LAYER...BUT STRONGER WINDS ALOFT MAY RESULT IN LOW LEVEL WIND SHEAR ABOVE THAT SURFACE LAYER. WILL MONITOR FOR LATER UPDATES. LENNING //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH IN ALL ELEMENTS TODAY...THOUGH DEVELOPMENT OF A LAKE BREEZE IS NOT OUT OF THE QUESTION. * MEDIUM IN DEVELOPMENT OF LLWS TONIGHT. LENNING //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...NEAR DUE SOUTH WINDS GUSTING TO AROUND 30 KT IN THE AFTERNOON. CHC OF TSRA DURING THE EVE AND A SLGT CHC OF LIGHT RAIN/SNOW DURING THE OVERNIGHT. TUESDAY...MORNING MVFR POSSIBLE. WEDNESDAY...EAST FLOW WITH RAIN AND MVFR/IFR LIKELY. THURSDAY...EAST FLOW WITH CHC OF RAIN AND POSSIBLE IFR. FRIDAY...CHC OF RAIN DURING THE DAY. SLGT CHC OF RAIN/SNOW DURING THE NIGHT. MTF && .MARINE... 251 PM CDT NORTH-NORTHEASTERLY ONSHORE FLOW ACROSS NORTHEASTERN ILLINOIS AND NORTHWESTERN INDIANA CONTINUES UP AROUND 20S OUT AHEAD OF AN AREA OF HIGH PRESSURE. THIS FLOW IS BIT STRONGER THAN PREVIOUSLY THOUGH...AND AS A CONSEQUENCE OF THIS...I HAVE ISSUED A SMALL CRAFT ADVISORY THROUGH THIS EVENING...MAINLY FOR THE EXPECTATION THAT WAVES ARE AT OR JUST ABOVE THE 4 FOOT MARK. THESE WINDS WILL ABATE THIS EVENING...THEN GRADUALLY BECOME EAST-SOUTHEASTERLY OVERNIGHT TONIGHT AS THE SURFACE RIDGE SHIFTS OVER THE LAKE. LOW PRESSURE WILL BE IN THE PROCESS OF DEVELOPING ACROSS THE CENTRAL HIGH PLAINS ON SUNDAY...AND THIS WILL RESULT IN A CONTINUAL SOUTH-SOUTHEASTERLY FLOW PATTERN ACROSS THE LAKE FOR THE NEXT COUPLE OF DAYS. THE LOW IS EXPECTED TO TRACK EAST-NORTHEASTERLY TO THE UPPER MISSISSIPPI VALLEY BY LATE MONDAY EVENING...THEN SHIFT ACROSS THE UPPER GREAT LAKES BY TUESDAY EVENING. OVERALL...THIS WILL RESULT IN INCREASING SOUTHERLY WINDS MONDAY AND INTO MONDAY EVENING...LIKELY TO AROUND 30 KT. OVERALL...IT APPEARS THAT WARMER AIR MOVING OVER THE LAKE WILL RESULT IN A STABLE MARINE LAYER...WHICH WOULD RESULT IN LOWER CHANCES FOR GALES. HOWEVER...SOME STRONGER WINDS NEARLY GALE FORCE ARE POSSIBLE WITH THIS SYSTEM...ESPECIALLY MONDAY NIGHT AS THE LOW AND COLD FRONT APPROACH THE LAKE. WESTERLY FLOW WILL SET UP TUESDAY IN THE WAKE OF THIS SYSTEM. ANOTHER STORM SYSTEM LOOKS TO TAKE AIM ON THE LOWER GREAT LAKES LATER IN THE PERIOD...AROUND THURSDAY. THIS COULD RESULT IN A PERIOD OF SOME ENHANCED NORTHEASTERLY WINDS INTO THE END OF THE UP COMING WEEK. KJB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1150 PM CDT Sat Mar 29 2014 .DISCUSSION... ISSUED 822 PM CDT Sat Mar 29 2014 Have made adjustments to sky grids to push clearing a bit faster than current package. Otherwise going forecast looks good. Surface ridge moving into forecast area attm and winds have decoupled despite significant northwest winds above the boundary layer associated with strengthening system over the central Appalachians. This flow above developing inversion continues to erode cloud cover and advect drier air into Illinois from northwest to southeast. Trapped moisture under the inversion may lead to some patchy ground fog. Attm, it appears that lowest vsbys should be around 3SM so will leave out of grids/zones but keep it in eastern TAF sites. Latest Lamp guidance in good agreement with ongoing forecast for tonight`s lows. Barker && .AVIATION... ISSUED 1150 PM CDT Sat Mar 29 2014 Surface ridge is oriented northeast to southwest near the Illinois River late this evening. Clear skies and light winds continue. Still somewhat concerned with potential for ground fog later tonight under almost perfect radiational cooling conditions, particularly in areas that had precipitation last night. Will introduce IFR vsbys late tonight given that they are beginning to show a downward trend. KDEC had a bit more drying time this afternoon than KCMI and will keep lowest vsbys MVFR there. Will also introduce MVFR vsbys at KSPI. Even though the temp-dew point spread is higher, several airports nearby (IJX, 3LF, TAZ) are already indicating reduced vsbys. Southerly flow develops on the back side of the ridge as it moves east of the area Sunday. Winds will likely become gusty, particularly across western terminals during the afternoon. Some Cirrus will be likely during the afternoon as the next system develops over the central high plains. Barker && .PREV DISCUSSION... ISSUED 228 PM CDT Sat Mar 29 2014 The progressive weather pattern will provide active weather next week as several storm systems affect Illinois. The latter half of this weekend looks pleasant with plenty of sunshine pushing temps above normal. However, by Monday afternoon the first system will bring chances of rain, and the onset of a return to cooler conditions. Heavier rains in the Wed to Thur time frame could accumulate between 1-2" in some locations. Localized flooding may develop. SHORT TERM...Tonight through Sunday night. Low clouds have been keeping high temps generally below forecast highs this afternoon. A narrow break in the cloud cover allowed Peoria to spike up about 10 degrees in a couple hours, and create a large temperature gradient over short distances in our forecast area. The RAP and HRRR layer RH indicate that some clearing should continue west of I-57 between 23z and 03z. Lows tonight will be dependent on cloud cover. Areas east of I-57 may remain cloudy until just after midnight as NE surface winds continue to drag low- level moisture from the Great Lakes into eastern IL. Even a few hours of clearing later tonight should allow eastern areas to cool off to near guidance lows, especially with surface dewpoints dipping into the upper 20s in many locations. Sunday will see mid level temps climb 5 to 7C during the day as an upper level ridge axis advances into eastern IL by 00z/7pm Monday. Near full sunshine should combine with increasing south winds to push highs about 10 to 15 deg above normal (60s), which will be a welcome taste of Spring. An tightening pressure gradient ahead of the next system will keep south winds up in the 10 to 20 mph range even Sunday night. So despite clear skies Sunday night, south winds will keep a mixed boundary layer and allow lows to be in the upper 40s west and around 40 east. LONG TERM...Monday through Saturday. Increasing clouds on Monday will not prohibit highs from climbing well into the 60s for one more day, as south-southeast winds increase into the 25 to 35 mph range. By Monday afternoon, a parent low pressure system will advance from eastern Nebraska to southeastern Minn, as a cold front reaches the western border of IL by 00z/7pm Monday. Pre-frontal storms will have a high amount of wind shear and storm relative helicity available, along with steep lapse rates, but a limited amount of moisture. Forecast soundings show the best instability may be at or above 750 mb, so any thunderstorms will be elevated to begin. Due the strong jet dynamics and wind shear with this system, some of the storms could begin rotating and produce hail and strong winds Monday afternoon and evening ahead of the cold front. Showers and storms should end from west to east by midnight in the post-frontal subsidence and dry air intrusion. Clouds will likely clear out behind the line of precip, so lows in the NW could dip below freezing, while southeast areas remain in the low 40s. The brief pocket of cold air is forecast to brush across N IL late Mon night and Tues morning, which will keep highs about 10-15 deg colder than Monday. High temps will range from around 50 near Galesburg to around 60 by Lawrenceville. Return flow behind the cooler high pressure will bring increasing moisture Tuesday night, with a few showers possible before sunrise on Wednesday. Thunderstorm chances will increase along and south of a warm front that is expected to develop directly across central IL from west to east. Storm chances will be higher in the warm sector roughly south of a line from Rushville to Champaign. Instability may have a better chance of being based closer to the surface as dewpoints climb into the 50s Wed night south of the warm front, which will be close to overnight low temps. Precipitable water values are expected to climb over an inch Wed night through Thursday as low pressure tracks northeast along the warm front. Locally heavy rain may occur in any thunderstorms, with training of storms over the same area also boosting rainfall amounts. Localized flooding could develop in low areas, as rainfall amounts possibly reach between 1 and 2 inches by Thursday afternoon. A wide range of temps will occur across C IL from north to south from Tues night through Thursday as the warm front lingers across the middle of the area. The temp spreads could be 20 to 25 degrees from north to south for highs and lows. There is a spread of solutions for how the surface and upper level systems progress from after Thursday. The GFS lingers the upper trough farther west Thurs night, then brings a secondary surface low and another round of rain showers across IL on Friday. The ECMWF is more progressive and drys out the air column after the low on Thursday. So low chance and slight chance PoPs were included Thurs night and Friday to account for a slower progression. There is some agreement that another push of cold air will keep temps below normal for Friday and Saturday, with Saturday looking dry at this time. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
129 AM EDT SUN MAR 30 2014 .SYNOPSIS... ISSUED AT 758 PM EDT SAT MAR 29 2014 SKIES WILL CONTINUE TO CLEAR THIS EVENING. OVERNIGHT LOWS WILL BE COLD IN THE LOWER TO MID 20S. TEMPERATURES WILL THEN WARM UP NICELY ON SUNDAY INTO THE LOWER TO MID 50S. EVEN WARMER CONDITIONS ARE ANTICIPATED ON MONDAY AS HIGH TEMPERATURES RISE INTO THE MID 60S UNDER PARTLY CLOUDY SKIES. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 328 PM EDT SAT MAR 29 2014 NO SIG ISSUES TO WORRY ABOUT FOR THE SHORT TERM AS RAIN/SNOW THAT HAS FELL ACROSS MUCH OF THE SOUTHERN GREAT LAKES TODAY WAS NEARLY OUT OF THE FORECAST AREA. FOCUS WILL SHIFT TO CLEARING TONIGHT AND HOW WARM WE GET ON SUNDAY. BY IN LARGE THE HEAVIER SNOWBANDS HAVE DIMINISHED WITH REMAINING RAIN/SNOW ACROSS PORTIONS OF HENRY/PUTNAM AND ALLEN COUNTIES IN OHIO. SFC LOW WAS OVER NE TENNESSEE AT 18Z AND SLOWLY DEEPENING WITH AN INCREASING PRESSURE GRADIENT AROUND IT. THIS WILL KEEP SOMEWHAT BREEZY CONDITIONS MAINLY EAST INTO THIS EVENING BEFORE THE LOW SHIFTS EAST. LOW CLOUDS HAVE BEEN SLOW TO ERODE IN THE WEST AND NORTH WITH NAM AND RUC VARYING ON HANDLING OF CLEARING. RUC 925/850 MB RH PLOT HAVE HANDLED THINGS WELL AND LINGER LOW CLOUDS INTO LATE EVENING WITH NAM MUCH QUICKER ERODING MSTR. WITH VIS SAT SHOWING HINTS AT SOME THIN SPOTS STARTING TO APPEAR SO HAVE TRIED TO BLEND THE 2 MODELS WHICH STILL BRINGS GENERALLY CLEAR SKIES BY LATE EVENING. LOWS WILL DROP INTO THE 20S DESPITE COLDEST AIR WITH THE SYSTEM ALREADY EAST OF THE REGION AND WAA UNDERWAY LATER TONIGHT. SOME OF THIS WAA WILL BE REALIZED ON SUNDAY AS LOTS OF SUNSHINE ALLOWS FOR MIXING THROUGH AT LEAST 900 MB AND MAYBE A BIT HIGHER YIELDS HIGHS IN THE 50S. WOULDN`T BE ENTIRELY SURPRISED TO SEE SOME UPR 50S TO NEAR 60 IN FAR W/SW AREAS. && .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 328 PM EDT SAT MAR 29 2014 VERY FEW CHANGES TO OVERALL IDEA IN LONG TERM PERIOD. AN ACTIVE PATTERN WILL CONTINUE THROUGH THE PERIOD WITH NUMEROUS SHORT WAVES AND A QUASI STATIONARY BOUNDARY IN THE REGION. THIS SHOULD LEAD TO RATHER WET PERIOD WITH TEMPERATURES A LITTLE CLOSER TO NORMAL FOR EARLY APRIL. RIDGE WILL BE OVER THE AREA SUNDAY NIGHT PROVIDING CLEAR SKIES AND LIGHT WINDS. LOWS EXPECTED IN THE LOWER 30S EAST UNDER RIDGE AXIS TO UPPER 30S WEST WHERE WARM AIR ADVECTION ON BACK SIDE OF RIDGE WILL BE INCREASING. THIS WARMING SHOULD TRANSLATE TO A LARGE DIURNAL SWING ON MONDAY AS STRONG MIXING DEVELOPS AND WARM AIR ALOFT IS ALLOWED TO MIX TO SURFACE. SHOULD BECOME BREEZY AS WELL TO HELP BOOST TEMPERATURES. INCREASING HIGH CLOUDS IN AFTERNOON MAY TEMPER WARM UP BY A FEW DEGREES DEPENDING ON HOW THICK CLOUD CANOPY IS AND TIMING OF IT. STILL EXPECT 60S ALL AREAS WITH RUN AT MID TO UPPER 60S ACROSS THE AREA IF SKIES REMAIN MOSTLY SUNNY THROUGH AFTERNOON PEAK HEATING. NEXT OF MANY SHORT WAVES MOVES THROUGH THE LAKES REGION MONDAY NIGHT WITH A TRAILING COLD FRONT THROUGH THE CWA EARLY TUESDAY MORNING. ENOUGH MOISTURE AND WEAK LIFT TO WARRANT LOW CHANCE POPS BUT STRONGEST FORCING TO THE NORTH CLOSER TO MAIN LOW. WARMEST TEMPS OF THE DAY LIKELY IN MORNING BEFORE FROPA BUT DRYING PROFILES TUE AFTERNOON SUGGEST SUN COULD ALLOW FOR SOME REBOUND SIMILAR TO WHAT SOME LOCATIONS EXPERIENCED FRIDAY. DETAILS REMAIN UNCERTAIN FOR REMAINDER OF LONG TERM WITH AFOREMENTIONED COLD FRONT BECOMING STATIONARY NEAR OR JUST SOUTH OF CWA. SEVERAL SHORT WAVES ARE EXPECTED WEDNESDAY INTO FRIDAY WITH ASSOCIATED SURFACE WAVES RIPPLING ALONG FRONTAL BOUNDARY. SEVERAL CHANCES FOR RAINFALL DURING THE PERIOD WITH UNCERTAINTY IN TIMING. THUS A CONTINUATION OF BROAD HIGH CHANCE POP CONTINUES WITH FURTHER INCREASE LIKELY AS TIME NEARS. WITH INCREASING PWATS AND THETA E AIR...MODERATE TO LOCALLY HEAVY RAINFALL AMOUNTS STILL PLAUSIBLE. TEMPS DURING THIS PERIOD LIKELY NEAR NORMAL SOUTH AND SLIGHTLY BELOW NORMAL NORTH BUT IF FRONT WAVERS NORTH OR SOUTH...SIGNIFICANT CHANGES IN TEMPERATURE FORECASTS WOULD BE EXPECTED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 128 AM EDT SUN MAR 30 2014 ELONGATE SFC RIDGE EXTENDING FM SE CANADA SWWD INTO THE LWR MS VALLEY WILL SHIFT EWD INTO THE ERN OH VALLEY ON MON. LT WINDS AND CLR SKIES WILL RESULT AT THE TERMINALS THROUGH THE PD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...BENTLEY/MURPHY SHORT TERM...FISHER LONG TERM...LASHLEY AVIATION...T VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
144 AM EDT SUN MAR 30 2014 .SYNOPSIS... LOW PRESSURE OVER THE MID ATLANTIC STATES WILL TRACK SLOWLY EAST... SOUTH OF THE AREA TONIGHT INTO EARLY NEXT WEEK && .NEAR TERM /THROUGH TODAY/... UPDATE... ADJUSTED POPS TO 100 PERCENT ACROSS DOWNEAST TO MATCH UP WITH LATEST RADAR IMAGERY. ALSO ADJUSTED HOURLY TEMPERATURES EARLY THIS MORNING PER LATEST OBSERVATIONS. THINK THE THREAT OF ANY -FZRA ACROSS INTERIOR DOWNEAST IS MINIMAL AT BEST SO REMOVED FROM OVERNGHT FORECAST. REST IOF FORECAST REMAINS ON TRCAK. ORGNL DISC: AT THE START OF THE PERIOD THE MAJOR MODELS ARE SHOWING THE NEXT SYSTEM TO AFFECT OUR AREA CENTERED OVER THE CNTRL PORTIONS OF THE NC/VA BORDER...WITH A WARM FRONT EXTENDING NORTH TO THE SW COAST OF MAINE. THE MODEL INDICATE THAT THE LOW IS STILL DYNAMIC AT THIS POINT...BUT SHOWING THAT THE UPPER LEVEL LOW IS STARTING TO BECOME VERTICALLY STACKED WITH THE SURFACE LOW...THE BEGINNING PROCESS OF BECOME COLD CORE. BY MRNG THE LOW MOVES NE TO THE NJ COAST...PRECIP SPREADS ACROSS ERN MAINE INTO NRN MAINE. PCPN WILL BE SNOW...WITH SLEET AND FREEZING RAIN MIXED IN ACROSS THE INTERIOR DOWNEAST AND EAST CNTRL MAINE. AT THIS TIME ALL MODELS SHOWING A CLOSED LOW AT 500MB AND THE SFC LOW NEARLY VERTICALLY STACKED. BY THE END OF THE PERIOD...THE BULK OF THE PCPN MOVES EAST INTO NEW BRUNSWICK...THE LOW DRIFTS NORTH ALONG THE NJ COAST TO JUST SOUTH OF LONG ISLAND. THE UPPER LOW AND SFC LOW WILL BE VERTICALLY STACKED. THE GFS...GEM...AND ECMWF SHOW A NEW LOW IN THE ERN GULF OF MAINE THAT WILL BECOME THE NEW PRIMARY LOW FOR THIS SYSTEM AS IT TRACKS TOWARD NEW BRUNSWICK. LOADED THE HRRR MIN TEMP FOR THE OVRNGT...GEM MAX TEMP FOR TOMORROW. INTERPOLATED FROM MIN TO MAX FOR HRLY TEMPS. USED A BLEND OF NAM/GFS/GEM/ECMWF FOR HRLY DP/SKY/WND/POP. ADDED 15 PERCENT TO WINDS FOR GUSTS OVER LAND...25 PERCENT OVER WATERS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... A VERTICALLY STACKED SURFACE/UPPER LOW WILL BEGIN TO MOVE SLOWLY NORTHEAST SUNDAY NIGHT. A NEARLY STATIONARY FRONTAL BOUNDARY WILL EXTEND NORTHEAST FROM THE SURFACE LOW. ISENTROPIC LIFT AND OVERRUNNING IN THE VICINITY OF THE FRONT WILL SUPPORT PRECIPITATION ACROSS THE FORECAST AREA SUNDAY NIGHT. HOWEVER...THE PROXIMITY OF THE FRONT TO THE COAST REMAINS UNCERTAIN. HAVE BASED THE FORECAST ON A SLOWER MOVEMENT OF THE SURFACE LOW AND THE FRONT REMAINING CLOSER TO THE COAST WHICH WILL KEEP MORE EXTENSIVE PRECIPITATION ACROSS THE FORECAST AREA. HIGH PRESSURE NORTH OF MAINE WILL CONTINUE TO PROVIDE LOW LEVEL COLD AIR ACROSS THE FORECAST AREA SUNDAY NIGHT INTO MONDAY. HOWEVER...WARMER AIR ALOFT WILL KEEP A WINTRY MIX ACROSS MUCH OF THE FORECAST AREA SUNDAY NIGHT. A WINTRY MIX WILL PERSIST ACROSS NORTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA SUNDAY NIGHT...WITH RAIN TRANSITIONING TO A WINTRY MIX ACROSS DOWNEAST AREAS. WINTER STORM WARNINGS WILL REMAIN IN EFFECT ACROSS NORTHERN AREAS SUNDAY NIGHT...WITH WINTER WEATHER ADVISORIES ACROSS CENTRAL AREAS AND INTERIOR DOWNEAST PORTIONS OF THE FORECAST AREA. HAVE HELD WITH THE SLOWER MOVEMENT OF THE SYSTEM MONDAY...WHICH WILL KEEP LIGHT PRECIPITATION ACROSS THE FORECAST AREA. ACROSS NORTHERN AREAS EXPECT EXPECT A LIGHT WINTRY MIX...WITH A WINTRY MIX TRANSITIONING TO RAIN ACROSS CENTRAL AND DOWNEAST AREAS. THE SURFACE/UPPER LOW WILL MOVE EAST MONDAY NIGHT WHILE HIGH PRESSURE SLOWLY BUILDS SOUTH WITH DECREASING RAIN/SNOW SHOWER CHANCES ACROSS THE FORECAST AREA. A SLIGHT CHANCE OF SHOWERS COULD PERSIST DOWNEAST TUESDAY WITH THE EXITING LOW WHILE HIGH PRESSURE BUILDS ACROSS NORTHERN MAINE. TEMPERATURES WILL BE AT SLIGHTLY BELOW NORMAL LEVELS MONDAY/TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... LOW PRESSURE WILL BE MOVING AWAY TUESDAY NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE WEST. THIS WILL BRING DRY AND RELATIVELY MILD WEATHER TUESDAY NIGHT INTO WEDNESDAY. A WEAK TROUGH MAY MOVE THROUGH ON THURSDAY BRINGING SOME CLOUDS AND PERHAPS LIGHT SHOWERS. OTHERWISE, THE DAY SHOULD REMAIN MOSTLY CLOUDY. HIGH PRESSURE SHOULD THEN BUILD IN BRINGING DRIER AND SEASONABLY MILD CONDITIONS ON FRIDAY. GOING INTO THE WEEKEND, LOTS OF UNCERTAINTY REGARDING WHETHER OR NOT A BLOCKING RIDGE OVER EASTERN CANADA CAN MAINTAIN THE DRY WEATHER. THE GFS KEEPS CONDITIONS DRY WHILE THE ECMWF BRINGS A TROUGH OF LOW PRESSURE THROUGH WITH A CHANCE FOR SOME RAIN OR SNOW SHOWERS. IN THE FORECAST WILL HAVE LOW CHANCE FOR RAIN OR SNOW SHOWERS NEXT WEEKEND. CURRENTLY DOES NOT LOOK LIKE ANY MAJOR STORMS ARE EXPECTED THROUGH NEXT WEEKEND, AND TEMPERATURES WILL BE NEAR NORMAL WHICH WILL BE CONSIDERABLY MILDER THAN THE VERY COLD CONDITIONS WE HAVE HAD IN MARCH. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... NEAR TERM: DETERIORATING CONDITIONS SOUTH TO NORTH AS THE LOW MOVES INTO THE AREA. MVFR CONDITIONS BHB...ALL OTHER SITES VFR TO START THE PERIOD THIS EVENING. BY 9PM IFR CONDITIONS BHB IN RAIN...BGR RAIN BCMG MXD. IFR CONDITIONS MOVE INTO HUL...PQI...CAR...FVE AFT 3AM...PCPN SNOW BCMG MXD AT HUL TOMORROW AFTN. IFR CONDITION WILL REMAIN ACROSS THE AREA THROUGH THE END OF THE PERIOD. PCPN TYPE SN FOR FVE...SN MAY MIX WITH PL BRIEFLY IN AFTN IN PQI AND CAR. SHORT TERM: IFR/LIFR CONDITIONS ARE EXPECTED ACROSS THE REGION SUNDAY NIGHT INTO EARLY MONDAY...WITH MVFR/IFR CONDITIONS LATER MONDAY. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE REGION MONDAY NIGHT. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS DOWNEAST AREAS EARLY TUESDAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED ACROSS THE REGION TUESDAY. VFR CONDITIONS ARE EXPECTED ACROSS THE REGION WEDNESDAY. VFR CONDITIONS ARE EXPECTED ACROSS NORTHERN AREAS THURSDAY...WITH OCCASIONAL MVFR CONDITIONS POSSIBLE DOWNEAST. && .MARINE... NEAR TERM: 1000 PM UPDATE...WITH NO INTERIM SCA HDLN AND WINDS FCST TO REACH LOW END GALE FORCE GUSTS IN ABOUT 12 TO 15 HRS...WE THOUGHT IT BEST TO CONVERT THE GALE WATCH TO A WARNING FOR THE SAME PD OF TM ADVERTISED IN THE WATCH...NAMELY SUN AFTN THRU LATE MON NGT...WITH THE 18Z GFS ADVERTISING GALE FORCE WIND GUSTS FOR APPROXIMATELY THIS TM PD. ORGNL DISC...THE LOW WILL TRANSIT SLOWLY SOUTH OF OF THE GULF OF MAINE. TODAYS TRACK IS FARTHER SOUTH THAN WAS PREVIOUS FORECASTED. WINDS STILL CALL FOR MARGINAL GALE FORCE WINDS FOR TOMORROW. WILL CONTINUE THE GALE WATCH. SHORT TERM: MARGINAL GALE CONDITIONS ARE POSSIBLE SUNDAY NIGHT INTO EARLY MONDAY NIGHT WHICH COULD REQUIRE GALE WARNINGS. VISIBILITIES WILL BE REDUCED IN RAIN SUNDAY NIGHT INTO EARLY MONDAY NIGHT...WITH LINGERING RAIN/SNOW SHOWERS POSSIBLE LATER MONDAY NIGHT INTO TUESDAY. && .HYDROLOGY... A FLOOD WATCH CONTINUES FOR DOWNEAST MAINE SUNDAY THROUGH MONDAY AFTERNOON. THE PRECIPITATION ASSOCIATED WITH THE UPCOMING STORM WILL LIKELY FALL MAINLY AS RAIN OR FREEZING RAIN IN THESE AREAS, ESPECIALLY ALONG THE COAST. TOTAL LIQUID PRECIPITATION AMOUNTS OF UP TO 3 INCHES ARE EXPECTED. IN ADDITION TO THIS RAIN...TEMPERATURES WILL REMAIN NEAR OR ABOVE FREEZING THROUGH SUNDAY ADDING SNOWMELT TO THE EQUATION. THE SNOWPACK IN THESE AREAS IS HIGHLY VARIABLE, RANGING FROM AROUND 6 INCHES ALONG THE COAST TO 2 FEET OR MORE IN THE INTERIOR. THERE IS 2 TO 4 INCHES OF WATER CONTAINED IN THE PACK ALONG THE COAST WITH 6 TO 8 INCHES FURTHER INLAND. WHILE THE DEEPER SNOW WILL BE ABLE TO ABSORB SOME OF THE RAIN...MUCH OF IT WILL BECOME RUNOFF IN ADDITION TO THE SNOWMELT. THIS MEANS DOWNEAST AREAS COULD POTENTIALLY SEE 4 INCHES OR MORE OF TOTAL RUNOFF. RIVERS WILL LIKELY RISE SUBSTANTIALLY AND POTENTIALLY CAUSE RIVER ICE TO BREAK UP...ESPECIALLY IN THOSE PLACES WHERE THE ICE COMPLETELY FLUSHED OUT IN JANUARY (MEANING THE ICE THERE NOW IS RELATIVELY WEAK). FOR THOSE RIVER STRETCHES THAT ARE ICE FREE...ICE COVER UPSTREAM MAY BREAK UP AND COLLECT DOWNSTREAM. IN ADDITION TO THE POTENTIAL FOR ICE JAMS, THIS AMOUNT OF RAINFALL AND RUNOFF WILL LIKELY LEAD TO PONDING OF WATER ON ROADWAYS AND MINOR FLOODING OF LOW-LYING POOR DRAINAGE AREAS. IN ADDITION, TIDAL LOCATIONS SUCH AS BANGOR WILL HAVE TO BE WATCHED CLOSELY AROUND THE TIME OF HIGH TIDE. THE CURRENT OFFICIAL NATIONAL WEATHER SERVICE FORECAST FOR THE PENOBSCOT RIVER AT BANGOR BRINGS THE GAGE WITHIN 1 FOOT OF FLOOD STAGE WITH HIGH TIDE SUNDAY MORNING. PERSONS WITH INTERESTS ALONG WATERWAYS OR IN FLOOD-PRONE LOCATIONS ACROSS HANCOCK...WASHINGTON AND SOUTHERN PENOBSCOT COUNTIES SHOULD STAY TUNED FOR ADDITIONAL INFORMATION ON THIS SYSTEM. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER STORM WARNING FROM 6 AM THIS MORNING TO 8 AM EDT MONDAY FOR MEZ001-002. WINTER STORM WARNING UNTIL 8 AM EDT MONDAY FOR MEZ003>006-010. WINTER WEATHER ADVISORY UNTIL 8 AM EDT MONDAY FOR MEZ011- 015>017-031-032. FLOOD WATCH FROM 8 AM EDT THIS MORNING THROUGH MONDAY AFTERNOON FOR MEZ015>017-029-030. GALE WARNING FROM NOON TODAY TO 4 AM EDT TUESDAY FOR MEZ029. MARINE...GALE WARNING FROM NOON TODAY TO 4 AM EDT TUESDAY FOR ANZ050>052. && $$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
311 AM EDT SUN MAR 30 2014 .SYNOPSIS... ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH MONDAY...BRINGING PLENTY OF SUNSHINE AND INCREASINGLY WARMER TEMPERATURES. A FRONT CROSSING THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY WILL BRING A CHANCE FOR SOME LIGHT SHOWERS...ALONG WITH A RETURN TO COOLER WEATHER. RAIN MAY MIX WITH...OR EVEN CHANGE OVER...TO A BIT OF SNOW ON TUESDAY...BUT NO ACCUMULATIONS ARE EXPECTED. COOL WEATHER WILL CONTINUE FOR THE MIDDLE AND END PORTIONS OF THE WEEK...WITH ANOTHER CHANCE FOR A WINTRY MIX OF PRECIPITATION THURSDAY AND FRIDAY. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH IMPACT WEATHER POTENTIAL: NONE. PATTERN SUMMARY: AN EARLY MORNING LOOK AT THE PATTERN ACROSS THE CONUS REVEALS AN ACTIVE SETUP...WITH LOW PRESSURE SYSTEMS ALONG BOTH COASTS...AND A NARROW RIDGE OF HIGH PRESSURE IN BETWEEN THESE SYSTEMS... ARCHING FROM QUEBEC...THROUGH THE GREAT LAKES AND DOWN THE MISSISSIPPI VALLEY. THIS RIDGE AXIS CURRENTLY LIES JUST WEST OF THE FORECAST AREA...WITH A RIBBON OF CLEARING ALLOWING LOW TEMPERATURES TO FALL RAPIDLY AS BOUNDARY LAYER WINDS DECOUPLE. LOOKING FORWARD THROUGH THE SHORT TERM FORECASTS REQUIRES US TO LOOK UPSTREAM...AND...SOMEWHAT DIFFERENTLY THAN WE HAVE SEEN OF LATE...MUCH OF WHAT IS UPSTREAM IS DOMINATED BY PACIFIC...MARITIME POLAR AIR...WITH ANY ARCTIC AIR NOW BOTTLED UP NORTH OF THE REGION. THIS PACIFIC FLOW WILL RESULT IN LEE-SIDE CYCLOGENESIS EAST OF THE ROCKIES DURING THE DAY TODAY...WITH THIS LOW PRESSURE DEEPENING AND BEGINNING TO DEPART TO THE NORTH AND EAST BY THE END OF THIS PERIOD AROUND DAYBREAK MONDAY. THE DOWNSTREAM LONGWAVE TROUGH IS MUCH SLOWER MOVING...AND THE DEVELOPING SQUEEZE PLAY IN BETWEEN THESE FEATURES WILL FORCE HEIGHTS TO BUILD OVER THE GREAT LAKES WITH QUIET AND MODERATING CONDITIONS EXPECTED FOR NORTHERN MICHIGAN. CERTAINLY A WELCOME REPRIEVE FROM AN EXCEPTIONALLY COLD MONTH OF MARCH. THROUGH DAYBREAK: TEMPERATURES WILL CONTINUE TO TUMBLE THROUGH THE TEENS GIVEN CLEAR SKIES AND CALM-LIGHT WINDS. ALSO CAN/T RULE OUT SOME PATCHY GROUND FOG GIVEN IMPRESSIVE OVERNIGHT COOLDOWN. TODAY: RIDGE AXIS WILL BE PRETTY MUCH OVERHEAD TO START THE DAY...GRADUALLY SHIFTING EAST TO A POSITION OVER LAKE HURON TOWARDS EVENING. THERE/S A RELATIVE LACK OF MOISTURE THROUGH THE COLUMN TO START THE DAY WITH PWATS SUB 0.25" /A LITTLE BELOW SEASONAL NORMS FOR LATE MARCH/ WITH VALUES INCREASING DURING THE DAY AS A CHUNK OF PACIFIC MOISTURE /SEEN NOW AS A PLUME OF DEEP MOISTURE ACROSS THE NORTHWESTERN QUARTER OF THE COUNTRY/ RIDES EAST. WHILE THIS COULD MANIFEST ITSELF AS SOME HIGH CLOUDS FOR THE NORTHERN HALF OF THE CWA /ESP FOR THE SECOND HALF OF THE DAY/...THE LACK OF LLEVEL MOISTENING BENEATH BUILDING MID LEVEL HEIGHTS SUGGESTS NO REAL POTENTIAL FOR CU DEVELOPMENT. THUS...EXPECT ABUNDANT SUNSHINE FOR THE AREA WITH NO SENSIBLE WEATHER CONCERNS. TEMPERATURES /CONFIDENCE: HIGH/: TRAJECTORY ANALYSIS PLACES THIS AFTERNOON/S AIRMASS OVER SOUTHERN MINNESOTA 24 HOURS PREVIOUS WITH T9S SURGING TO 0-3C BY LATE AFTERNOON UNDER STRONG WARM ADVECTION. WITH BUILDING HEIGHTS AND NEARBY RIDGE AXIS...MIXING ISN/T GOING TO BE TOO STRONG. LOOKING BACK TO MINNESOTA...AREAS THAT WERE UNABLE TO MIX DEEPLY REACHED THE LOWER 40S...WITH UPPER 40S FURTHER WEST WHERE MECHANICAL MIXING COMBINED WITH WARMER TEMPS ALOFT TO BOOST SURFACE TEMPS. EXPECT THAT WE/LL BE CLOSER TO THE FORMER TODAY...AND EXPECT HIGHS IN THE 40-45 DEGREE RANGE. AMAZINGLY...THAT WILL PUT US JUST ABOUT WHERE WE SHOULD BE FOR THE END OF MARCH. AS MENTIONED BY THE PREVIOUS DAYSHIFT...LIGHT FLOW REGIME AND SOMEWHAT WARMER TEMPERATURES SHOULD ALLOW FOR SOME LAKE BREEZE DEVELOPMENT...KEEPING HIGHS LOCALLY COOLER ALONG THE LAKE HURON COAST. TONIGHT: RIDGE CONTINUES TO PUSH EAST OF THE GREAT LAKES REGION...WITH NORTHERN STREAM COLD FRONT STALLING NEAR LAKE SUPERIOR AS LOW PRESSURE ALONG THE EAST SLOPES OF THE ROCKIES BEGINS TO DEPART AND HEAD NORTHEAST. MOISTURE CONTINUES TO SLOWLY INCREASE...BUT PRIMARILY AT UPPER LEVELS WITH TOP-DOWN SATURATION LIKELY ONLY YIELDING AN INCREASE IN UPPER LEVEL CLOUDS THROUGH THE OVERNIGHT. GRADIENT STRENGTHENS THROUGH THE NIGHT...WITH MOST LOCATIONS RE-COUPLING DURING THE OVERNIGHT. SEE NO REPEAT OF ANY FOG GIVEN BETTER LLEVEL MIXING AND CONTINUED DRY LLEVEL CONDITIONS. TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: TEMPERATURES WILL BE A LITTLE COMPLEX WITH EVENING MCLEAR SKIES AND DECOUPLING LIKELY TO GIVE WAY TO INCREASED MIXING AS THE NIGHT GOES ON. THIS WILL YIELD LOWS COLDEST OVER NORTHEAST LOWER WITH LOWS LIKELY TO DIP TO AROUND 20 /AND PERHAPS A TAD BELOW THIS/...WITH TEMPS OVER NORTHWEST LOWER STRUGGLING TO FALL MUCH BELOW THE FREEZING MARK. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 309 AM EDT SUN MAR 30 2014 ...REAL SPRING "WARMTH" GIVES WAY TO BELOW NORMAL TEMPERATURES (GO FIGURE)... HIGH IMPACT WEATHER POTENTIAL: WATCHING WINTRY PRECIP THREAT LATER IN THE WEEK. OVERVIEW: PATTERN REMAINS AN AGITATED ONE...WITH EXTENDED AMPED PACIFIC REGIME OVER THE CONUS TUCKED NICELY ON SOUTH SIDE OF WELL DEVELOPED NORTH CANADA COLD CORE GYRE. PACIFIC PATTERN CONTINUES TO WIN OUT OVER NORTHERN MICHIGAN...WITH STEADY RETREAT OF OVERHEAD COLD AIRMASS AS AGGRESSIVE UPSTREAM WARMING BEGINS. 00Z RAOB/HIGH RES RAP GUIDANCE CONFIRMS SUCH...SHOWING H8 TEMPERATURES SPIKING INTO THE TEENS (THAT`S ABOVE ZERO FOLKS!) ACROSS THE HIGH PLAINS...WITH ABOVE ZERO H8 AIR ALREADY ADVANCING TO THE MISSISSIPPI RIVER. EXPECTED RATHER SUBSTANTIAL UPPER MISSISSIPPI VALLEY LOW PRESSURE DEVELOPMENT EARLY THIS WORK WEEK WILL ONLY HELP THE NORTHERN LAKES WARMING CAUSE...WITH MUCH OF THE AREA TO FALL SQUARELY IN THE WARM SECTOR OF THIS SYSTEM AS IT TRACKS TO OUR NORTHWEST. UNFORTUNATELY...COOL AIR WILL BE FORCED SOUTH ON ITS BACKSIDE...ONCE AGAIN DROPPING TEMPERATURES TO BELOW NORMAL LEVELS AS WE HEAD THROUGH THE MID AND AND PORTIONS OF NEXT WEEK. PACIFIC WAVE TRAIN REMAINS...AT LEAST SETTING UP SOME POTENTIAL FOR BOUTS OF MORE WINTRY WEATHER HEADING INTO THURSDAY AND FRIDAY. OH...THE JOY! PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY! TEMPERATURE TRENDS THROUGHOUT...PRECIP TIMING/AND EVENTUAL TYPE...HEADING THROUGH NEXT WORK WEEK. DETAILS: JUST HOW WARM TO GO ON MONDAY? ABOUT TEXTBOOK END OF MARCH/BEGINNING OF APRIL SPRING STORM WILL BE UNDERGOING FULL DEVELOPMENT ACROSS THE CENTRAL PLAINS EARLY MONDAY...EXPECTED TO PASS SOMEWHERE VICINITY CENTRAL/WESTERN UPPER MICHIGAN TUESDAY. STRONG DOWNSTREAM OFF THE DECK WAA EXPECTED...WITH NOW MULTI-DAY PROGS SUPPORTING H8 READINGS SPIKING TO NEAR 10C BY LATER MONDAY OVER NORTHERN MICHIGAN. WITH ELEVATED WARM FRONT ALREADY NORTH OF THE AREA...AND CORE OF MID LEVEL DYNAMICS WELL OFF TO OUR WEST...WOULD EXPECT PLENTY OF SUNSHINE TO FURTHER KICK THE WARMING INTO OVERDRIVE. INCREASINGLY DEEP MIXED LAYER/FORCED MECHANICAL MIXING PER INCREASING WINDS SHOULD ALLOW SURFACE TEMPERATURES TO RESPOND ACCORDINGLY...AND REALLY LIKE INHERITED HIGHS WILL INTO THE 50S/NEAR 60 OVER NORTHERN LOWER MICHIGAN. SOUTHEAST LOW LEVEL FLOW WILL KEEP NORTHEAST LOWER AND EASTERN UPPER MICHIGAN SEVERAL DEGREES COOLER. MILD AIR CONTINUES INTO MONDAY NIGHT AS SOUTH FLOW REMAINS...AND FEEL SOME AREAS MAY FAIL TO FALL OUT OF THE 40S. DRY WEATHER GIVES WAY TO INCREASING SHOWER CHANCES MONDAY NIGHT AS OCCLUDED FRONT INTERACTS WITH NARROW BAND OF ENHANCED DEEP LAYER MOISTURE. STRONGEST AND DEEPEST DYNAMICS REMAIN TO OUR NORTHWEST...WHERE HEAVIEST AND STEADIEST PRECIPITATION SHALL RESIDE. BACK TO 2014 SPRING NORMALCY QUICKLY ON TUESDAY AS SURGE OF COLDER AIR FOLLOWS PASSAGE OF OCCLUDED FRONT. MORNING HIGH TEMPERATURES IN THE 30S AND 40S WILL SLOWLY FALL THROUGH THE AFTERNOON ON GUSTY SOUTHWEST TO WEST WINDS. LIGHT RAIN/SNOW SHOWERS TRANSITION TO MAINLY SNOW AS COLD AIR DEEPENS AND SYSTEM BACKSIDE MOISTURE REMAINS. JUST MINIMAL...IF ANY...ACCUMULATION IS EXPECTED. UNCERTAINTY THE NAME OF THE GAME HEADING INTO THE MID AND END PORTIONS OF THE WEEK. QUESTIONS ARE MANY CONCERNING NEXT WAVE EXPECTED TO EJECT OUT OF THE INTERMOUNTAIN WEST. INTERACTION BETWEEN SOUTHERN CANADA HIGH/ASSOCIATED DRY AIR FEED AND WHAT SHOULD BE RATHER VIGOROUS MID LEVEL WAVE LEADING TO RATHER SIGNIFICANT DISCREPANCIES AMONGST MID RANGE GUIDANCE. ECMWF REMAINS MOST ROCK-STEADY...SUGGESTING A MORE AMPED AND FURTHER NORTH SOLUTION WITH LOW PRESSURE MOVING DIRECTLY ACROSS THE GREAT LAKES TO END THE WORK WEEK. OTHER GUIDANCE STARTING TO FALL IN LINE WITH THIS MORE NORTH/AMPED SOLUTION...ALTHOUGH HONESTLY...THIS DOES LITTLE TO INCREASE CONFIDENCE AS A MORE SOUTH DISPLACED SYSTEM IS FULLY PLAUSIBLE GIVEN EXPECTED SET-UP AND POTENTIAL FOR A STRONGER CANADIAN HIGH. TEMPERATURE PROFILE REMAINS MARGINALLY SUPPORTIVE OF A MIXED PRECIP EVENT IF FURTHER NORTH SOLUTIONS VERIFY. SET-UP ALSO HAS SOME INTRIGUING FREEZING RAIN POSSIBILITIES...WITH POTENTIAL FOR MAINTENANCE OF DRY AND COLD EAST FLOW TO MAINTAIN SUB-FREEZING SURFACE TEMPERATURES...ALL THE WHILE ELEVATED WARM NOSE DEEPENS. OF COURSE...MUCH TOO FAR OUT TO SHOW SUCH SPECIFICS...ESPECIALLY CONSIDERING UNCERTAINTY IF SYSTEM WILL EVEN DIRECTLY AFFECT OUR AREA. LITTLE CHOICE BUT TO RUN WITH A GENERIC RAIN/SNOW CHANCE WORDING FOR NOW...WITH PLENTY OF TIME TO FINE-TUNE DETAILS IN COMING DAYS. WHILE EXCEPTIONALLY COLD AIR NOW LOOKS LIKE A THING OF THE PAST...OVERALL TRENDS FAVOR BELOW NORMAL TEMPERATURES WEDNESDAY THROUGH NEXT WEEKEND...WITH HIGHS MOSTLY IN THE 30S AND LOWER 40S/OVERNIGHT LOWS IN THE 20S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 116 AM EDT SUN MAR 30 2014 ...QUIET TODAY WITH LLWS CONCERNS TONIGHT... SUMMARY: HIGH PRESSURE OVERHEAD WILL GRADUALLY SHIFT EAST THROUGH THE TAF PERIOD...WITH VERY QUIET CONDITIONS EXPECTED. RESTRICTIONS: VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. OVERNIGHT DEWPOINT DEPRESSIONS HAVE REMAINED SUBSTANTIAL AND THEREFORE HAVE REMOVED FOG POTENTIAL FOR THE REMAINDER OF THE OVERNIGHT. SCATTERED HIGH CLOUDS EXPECTED TODAY...WITH THESE CLOUDS THICKENING SOME TONIGHT. ATMOSPHERE WILL MOISTEN THROUGH TODAY AND TONIGHT...BUT STRENGTHENING MIXING AS WELL AS INCREASING OVERNIGHT CLOUD COVER SHOULD PRECLUDE SIGNIFICANT FOG POTENTIAL SUNDAY NIGHT. WINDS: CALM-LIGHT/VARIABLE WINDS THROUGH DAYBREAK WILL BE LIGHT/VARIABLE THROUGH THE MORNING...BEFORE SOUTH/SOUTHEAST WINDS 5-10KTS DEVELOP THIS AFTERNOON FOR PLN/TVC/MBL...WITH MORE EASTERLY LAKE BREEZE FLOW 10 KTS AT APN. WINDS LIKELY TO GO LIGHT/VARIABLE AT APN THROUGH TONIGHT AND FOR SOME OF THE EVENING AT PLN/TVC/MBL... WITH SOUTHEAST WINDS AROUND 5KTS DEVELOPING AFTER MIDNIGHT. LLWS: POTENTIAL EXISTS FOR LLWS CONCERNS PARTICULARLY OVER NORTHWEST LOWER TONIGHT AS SOUTH TO SOUTHWESTERLY LOW LEVEL JET STRENGTHENS DURING THE EVENING HOURS ABOVE WHAT WILL LIKELY BE LIGHT SOUTHEASTERLY WINDS NEAR THE SURFACE. WILL INCLUDE LLWS MENTION AT MBL/TVC WHERE CONFIDENCE IS HIGHEST AT THIS TIME. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ SYNOPSIS...MSB SHORT TERM...ARNOTT LONG TERM...MSB AVIATION...ARNOTT
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1139 PM CDT Sat Mar 29 2014 .UPDATE: Issued at 919 PM CDT Sat Mar 29 2014 Area of MVFR stratus has continued to dissipate and is now confined to portions of south-central Illinois. Expect this area to completely erode by 0600 UTC with mainly clear skies for most of the rest of tonight. Exception would be over western areas as cirrus tries to advect in from the west/northwest. Surface temperatures over the past two hours have dropped very rapidly over most of the region where combination of clear skies/light winds exist. Lowered minimum temperatures a few degrees over many areas using a blend of the 0000 UTC RAP which was capturing this rapid drop fairly well as well as the previous forecast. Other concern overnight will be fog potential and patchy fog with restricted visibilities below 3 miles still looks on track though certainly could not rule out some denser fog especially in river valleys and other low-lying elevations. Gosselin && .SHORT TERM: (Through Late Tonight) Issued at 320 PM CDT Sat Mar 29 2014 Pesky stratus seems to be both clearing and eroding at a snails pace this afternoon and has a done number on the temperatures. Present indications based on satellite trends and the RAP which has handled the low clouds best, is that areas generally along and east of the MS River will see clouds into early evening with clearing from mid-late evening. Otherwise the expansive NE-SW high pressure system currently extending from WI into TX will slide east across the region tonight with the axis centered thru SE MO and southern IL at 12z. The slow clearing trend of the clouds along with light winds overnight across the SE third of the CWA has prompted me to add a mention of fog overnight. Glass .LONG TERM: (Sunday through Next Saturday) Issued at 320 PM CDT Sat Mar 29 2014 It finally looks like the warm-up will commence on Sunday. Heights aloft that begin rising tonight in the wake of the departing upper trof, will continue to rise on Sunday while the surface high retreats and low level southerly flow and warm advection get underway. There should be no low clouds to deal with a just some thin high clouds filtering across the region. The current forecast leveraging the warmer temperatures looks right on the mark and no changes were made. The warmer temps combined with low afternoon RH values and increasing southerly winds support an elevated fire danger threat across central and east central MO, which will be highlighted in the HWO. Continued southerly low level flow on Sunday night will lead to "milder" min temperatures and a slow return in low level moisture. The aforementioned expansive surface high and its southern extent will initially have a profounded effect on trajectories and delay quality moisture return. However mid level moisture won`t be an issue and this along with the eastern edge of steeper mid level lapse rates spreads into central MO just before daybreak on Monday. These ingredients along with the leading edge of forcing aloft associated with an upstream trof, suggests potential for some high-based scattered showers/thunderstorms and hence have added some slight chance pops. The week ahead looks especially active. The migratory upper trof partly responsible for the slight chance pops late Sunday night will move across the region Monday afternoon and early evening spreading height falls and cooling aloft along with a plume of steep mid level lapse rates. This combined with a gradual increase in low level moisture and forcing should be sufficient for scattered elevated showers/thunderstorms within the warm sector, moving through central and northeast MO during the morning gradually dwindling in coverage during the afternoon as they move east. By the time the cold front moves through the area Monday night, forcing aloft appears to have outrun the front and boundary layer moisture and hence instability are quite weak. I suspect anything that might be able to develop with be quite spotty and just have a slight chance pop. The most active period will be late Tuesday night into Thursday. The front that moves through Monday night will move back north and waver across the region. The warm sector air mass south of this boundary will become quite unstable thanks to continued northward return of quality Gulf moisture and the presence of steep mid level lapse rates, and with a strong low level jet evolving there will be good elevated instability and forcing north this boundary. The models differ quite a bit on the position of the next formidable migratory upper trof and the position of attendant surface low(s) and this boundary. While all the guidance supports a stormy period, the more northern position which has been consistently advertised by the ECMWF would lead to a much more volatile set-up. Glass && .AVIATION: (For the 06z TAFs through 06z Sunday Night) Issued at 1131 PM CDT Sat Mar 29 2014 Light fog has developed across the region, especially near and east of the Mississippi River (where daytime mixing was limited by persistent stratus) and in river valleys. Light fog will begin to lift and dissipate during the morning hours after winds start to increase in response to the tightening pressure gradient. LLWS is possible towards the end of the valid TAF period based on model depictions of strong winds around 1200 ft. Specifics for KSTL: Light fog is expected tonight, but visibilities should remain in the MVFR to VFR range. Winds will increase during the morning due to the tightening pressure gradient. LLWS is possible towards the end of the valid TAF period based on model depictions of strong winds around 1200 ft. Kanofsky && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
359 AM CDT SUN MAR 30 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT SUN MAR 30 2014 ANOTHER WARM DRY SURGE OF AIR MOVES OFF THE CNTL ROCKIES TODAY. THE TEMPERATURE FORECAST FOLLOWS THE UPPER MIDDLE OF THE 13 MODEL SUPER ENSEMBLE FOR HIGHS IN THE 70S TO NEAR 80. A STATIONARY FRONT IS EXPECTED TO DEVELOP ALONG THE SD BORDER CAUSING WINDS TO BACK ACROSS THE NORTH KEEPING HIGHS NEAR 70. WE ALSO SEE A FAIRLY SOLID CIRRUS SHIELD DEVELOPING OFF THE LARAMIE AND FRONT RANGE LIMITING HEATING SOMEWHAT. SOUTH WINDS INCREASE TO 10 TO 20 MPH WITH GUSTS TO 25 MPH ACROSS MOST OF THE FCST AREA. FOR TONIGHT...SFC LOW PRESSURE WILL TRACK THROUGH THE CENTER OF THE FCST AREA AND WINDS BECOME NORTHWEST BEHIND THE SFC LOW ACROSS WRN NEB. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING AND OVERNIGHT IN RESPONSE TO A LOW LEVEL JET AND COOLING/FALLING HEIGHTS ALOFT. THE NEW MODEL CONSENSUS BRINGS A SHARP 500 MB TROF INTO ERN WY AT 06Z WHICH CLOSES OFF ACROSS NW NEB BY 12Z. THERE ARE SIGNS OF THE HEIGHTS BACKING IN ALOFT ACROSS WRN SD AT THIS TIME WHICH IS TROUBLING SINCE THE LATEST ENSEMBLE SOLN IS TAKING THE UPPER LEVEL ENERGY ACROSS THE TETONS AND BIG HORN RANGES BUT THEN IT DROPPING SOUTH OF THE BLACK HILLS. THIS MORE SRN TRACK RAISES THE POP ACROSS NWRN NEB BETWEEN 06Z AND 12Z. THE NAM AND GEM REGIONAL THEN BRING THE RAIN SNOW LINE INTO NRN SHERIDAN COUNTY BETWEEN 09Z AND 12Z. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 359 AM CDT SUN MAR 30 2014 ATTENTION IN THE EXTENDED PERIODS CENTER ON PRECIPITATION CHANCES...MAINLY THE POTENTIAL OF TWO SIGNIFICANT LATE WINTER TYPE STORMS THAT MAY BRING ACCUMULATING SNOW TO PORTIONS OF THE CWA. THE FIRST SYSTEM WILL BE ONGOING ACROSS OUR NORTHERN ZONES BY 12Z MONDAY. LOW PRESSURE AND ASSOCIATED PV ANOMALY WILL CROSS FROM THE CENTRAL ROCKIES NORTHEAST OUT ONTO PLAINS...DRAGGING MODIFIED ARCTIC AIR SOUTH FROM CANADA ACROSS THE NORTHERN/CENTRAL PLAINS. MEDIUM RANGE MODELS HAVE GENERALLY COME INTO FAIR AGREEMENT WITH THE TRACK OF THE SURFACE CYCLONE...BUT INTENSITY/TIMING DIFFERENCES STILL EXIST. ATTM GENERALLY FAVOR THE GEM SOLUTION IN WHICH THE TRACK FAVORS STRONG FRONTOGENETIC FORCING MAINLY NORTH OF THE CWA. THAT BEING SAID...THERE/S STILL STRONG AGREEMENT THAT SNOW WILL WRAP AROUND THE LOW BACK ACROSS NORTHERN PORTIONS OF THE CWA. ATTM SNOW ACCUMULATIONS LOOK FAVORABLE FOR NORTHWESTERN NEBRASKA EARLY MONDAY...THEN TRANSITION EAST THROUGH THE DAY. THE PTYPE FORECAST IS STILL PROBLEMATIC. THE GEM SOLUTION IS WARMER WITHIN THE WARM SECTOR AS THE MODEL LIFTS THE LOW FURTHER NORTH THAN EAST...CHANGEOVER TO ALL SNOW MAY NOT OCCUR FOR OUR FAR EASTERN ZONES UNTIL MID-LATE AFTERNOON. WHERE THE CHANGE OVER DOES OCCUR EARLY...IMPACTS TO TRAVEL WOULD BE EXPECTED...ESPECIALLY GIVEN WIND GUSTS IN EXCESS 45 MPH. ATTM ALONG AND NORTH OF HIGHWAY 20 IN CHERRY AND SHERIDAN COUNTIES IS WHERE THE GREATEST CONFIDENCE IN SEEING THE EARLY CHANGEOVER AND ACCUMULATING SNOW. FOR THIS...WILL ISSUE A WINTER WEATHER ADVISORY WITH THIS FORECAST PACKAGE FOR THE TWO COUNTIES LISTED AS IMPACTS TO KVTN...RANCHING...HIGHWAY 20 AND THE POPULOUS CENTERED ALONG THE HIGHWAY ARE ANTICIPATED TO BE SIGNIFICANT. NOTE...IT COULD VERY WELL BE THAT SOUTHERN PORTIONS OF THESE TWO COUNTIES NOT SEE MUCH IF ANY ACCUMULATING SNOW WITH THIS SYSTEM WHILE THE FAR NORTH EXPERIENCES NEAR BLIZZARD CONDITIONS AND UP TO 4 INCHES OF SNOW. A HIGH END WIND ADVISORY IS ANTICIPATED MONDAY AS WELL ACROSS THE ENTIRE CWA. A STACKED PRESSURE GRADIENT WITH PRESSURE RISES ON THE ORDER OF UP TO 3 MB PER HOUR WILL LEAD TO NEAR HIGH WIND WARNING GUST CRITERIA. WILL LET THE DAY SHIFT FINE TUNE THE SPECIFICS. LASTLY...NEGATIVE LI/S ACROSS NORTH CENTRAL/NORTHERN NEBRASKA EARLY MONDAY WITH WEAK INSTABILITY ALOFT MAY YIELD A FEW EMBEDDED CONVECTIVE SHOWERS...WHETHER SNOW OR RAIN. NO MENTION OF THUNDER WAS INCLUDED BEYOND 12Z MONDAY...BUT MAY NEED TO BE LOOKED AT FURTHER. LOW AMPLITUDE TRANSITORY RIDGING BUILDS ATOP THE PLAINS ON TUESDAY WITH A RETURN TO AN ACTIVE PATTERN BY MIDWEEK. SOUTHWESTERLY FLOW IN THE UPPER LEVELS WILL PREVAIL AS THE NEXT LONGWAVE TROUGH OF INTEREST STARTS TO BUILD ACROSS THE DESERT SOUTHWEST WEDNESDAY. SLIGHT OPPORTUNITIES FOR QPF ALSO ARRIVE ON WEDNESDAY WITH THE APPROACH OF FAVORABLE UPPER LEVEL JET SUPPORT AND A SW DISTURBANCE. HOWEVER BETTER CHANCES ARRIVE LATE IN THE WEEK AS THE TROUGH EJECTS NORTHEAST FROM THE 4 CORNERS ONTO THE CENTRAL PLAINS. THERE REMAINS LARGE DISCREPANCIES ON HOW THE MODELS HANDLE THIS SYSTEM...WITH THE ECMWF NOW TAKING ON A NEGATIVE TILT AND A FAVORABLE TRACK OF THE H5 LOW FOR SNOW ACCUMULATION...POSSIBLY SIGNIFICANT ACROSS THE WEST CENTRAL SANDHILLS. THE GFS REMAINS OPEN AND PROGRESSIVE WITH FAR LESS IMPACTS. DUE TO THE MYRIAD OF WEATHER CURRENTLY GOING ON RIGHT NOW...FELT IT WAS BEST TO NOT VARY FROM A GENERAL MODEL BLEND WITH THIS LATE WEEK SYSTEM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1229 AM CDT SUN MAR 30 2014 VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THROUGH THE TAF PERIOD. ON SUNDAY...A WARM FRONT WILL DEVELOP NEAR OR JUST NORTH OF THE KVTN TERMINAL. THEREFORE PREVAILING SOUTHERLY WINDS 12G18KT CAN BE EXPECTED AFTER 18Z. HIGH CLOUDINESS WILL THICKEN AND LOWER LATER SUNDAY AFTERNOON FOR BOTH TERMINALS...BUT VFR WILL BE MAINTAINED. && .FIRE WEATHER... ISSUED AT 359 AM CDT SUN MAR 30 2014 RED FLAG CONDITIONS ARE EXPECTED ACROSS THE ERN PANHANDLE...CENTRAL SANDHILLS...FRENCHMAN BASIN AND THE LOESS PLAINS. THE FORECAST IS A LOW END RED FLAG WARNING AS THE RAP SHOWS WINDS AT 700MB WEAKENING THIS AFTERNOON WHILE THE NAM ACTUALLY STRENGTHENS THEM. THE FORECAST FOLLOWS A BLEND OF THE GUIDANCE FROM THE RAP13...HRRR...NAMDNG AND AVN MOS MODELS FOR SOUTH WINDS OF 10 TO 20 MPH AND GUSTS TO 25 MPH. DEWPOINTS SHOULD FALL INTO THE TEENS...BUT ABOUT 5 DEGREES F HIGHER THAN SATURDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 9 PM CDT /8 PM MDT/ THIS EVENING FOR NEZ204-206-210-219. WINTER WEATHER ADVISORY FROM 4 AM CDT /3 AM MDT/ TO 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004-005-094. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
511 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COMPLEX LOW PRESSURE SYSTEM WILL CONTINUE TO BRING MIXED PRECIPITATION TO THE NORTH COUNTRY THIS MORNING...AND TAPER OFF TO DRIZZLE AND FREEZING DRIZZLE THIS AFTERNOON. PORTIONS OF CENTRAL AND SOUTHERN VERMONT WILL CONTINUE TO SEE LIGHT ICE ACCUMULATIONS TONIGHT INTO MONDAY MORNING AS THE LOW TRACKS OFF THE EASTERN SEABOARD...WITH DRIER CONDITIONS RETURNING TO THE ENTIRE REGION BY MONDAY AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 510 AM EDT SUNDAY...FORECAST PLAYING OUT FAIRLY WELL WITH A MYRIAD OF PRECIPITATION TYPES EXPERIENCED ACROSS THE NORTH COUNTRY OVERNIGHT ASSOCIATED WITH LOW PRESSURE MOVING EASTWARD THROUGH THE MID-ATLANTIC STATES. ACROSS VERMONT...PRECIP STARTED OUT AS A MIX OF SNOW...RAIN AND FREEZING RAIN BUT AS OF 5 AM SEEING MAINLY A MIX OF RAIN AND SNOW. MEANWHILE...ACROSS NORTHERN NEW YORK SNOW HAS BEEN THE PREDOMINANT PTYPE WITH SEVERAL INCHES OF SNOW ACCUMULATIONS BEING REPORTED. MODEL OF CHOICE OVERNIGHT HAS BEEN THE RAP WHICH CONTINUES TO HANDLE THE VERTICAL THERMAL STRUCTURE VERY WELL SHOWING +0C LAYER AT 850MB SHIFTING NORTHWARD THROUGH VT WHILE FROM THE SURFACE-925MB REMAINED NEARLY ISOTHERMAL. AS THE BULK OF PRECIP SHIFTS NORTHWARD OUT OF THE REGION THIS MORNING...WE`RE LEFT WITH SUPER-SATURATED LOW LEVELS AND ZERO ICE IN THE FAVORED SNOW GROWTH REGION ALOFT ALONG WITH COOLING MID LEVELS. THIS WILL SUPPORT A TRANSITION TO DRIZZLE AND/OR FREEZING DRIZZLE ACROSS MOST OF THE AREA...THOUGH SOME LINGERING SNOW SHOWERS WILL BE POSSIBLE ACROSS THE SAINT LAWRENCE VALLEY DUE TO COLDER PROFILES. TEMPS WILL BASICALLY GO NOWHERE TODAY UNDER THICK CLOUD COVER AND NORTH TO NORTHEASTERLY FLOW...HOLDING STEADY IN THE LOW/MID 30S TO UPPER 20S AREA-WIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 510 AM EDT SUNDAY...FOR TONIGHT INTO MONDAY...MODELS HAVE COME INTO BETTER AGREEMENT IN REGARDS TO ANOTHER ROUND OF MIXED PRECIPITATION ACROSS CENTRAL AND SOUTHERN VERMONT AS ADDITIONAL SHORTWAVE ENERGY ROTATES AROUND THE SLOWLY DEPARTING UPPER LOW. LOW LEVEL TEMPERATURES COOL ACROSS THE AREA OVERNIGHT WHILE TEMPS AT MID-LEVELS REMAIN ABOVE FREEZING SETTING THE STAGE FOR AREAS OF FREEZING DRIZZLE/RAIN THROUGH MONDAY MORNING. GREATEST CHANCES OF ICE ACCUMULATION WILL BE OVER CENTRAL AND SOUTHEASTERN ZONES DUE TO THE PROXIMITY WITH UPPER LOW....AND WINTER WX ADVISORIES HAVE BEEN EXTENDED FOR A LIGHT GLAZE OF UP TO A TENTH OF AN INCH LIKELY. LATE MONDAY INTO MONDAY NIGHT DRIER CONDITIONS RETURN TO THE REGION AS DEEP LAYER RIDGING BUILDS EASTWARD FROM THE GREAT LAKES INTO THE NORTHEAST. SKIES CLEAR FROM WEST TO EAST WITH ANOTHER NIGHT OF BELOW NORMAL TEMPS EXPECTED IN THE TEENS TO 20S. SUNNY CONDITIONS ARE EXPECTED FOR TUESDAY UNDER THE RIDGE WITH TEMPERATURES REBOUNDING INTO THE 40S IN THE AFTERNOON. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 340 AM EDT SUNDAY...SEASONABLE EARLY SPRING TEMPERATURES ALONG WITH PERIODIC CHANCES OF RAIN OR SNOW SHOWERS WILL BE THE RULE DURING THE MIDDLE TO LATER PORTIONS OF NEXT WEEK. BEST SHOT AT PCPN WILL OCCUR TUE NT/WED MORNING...THEN AGAIN BY NEXT WEEKEND. THE MID-WEEK SYSTEM WILL BE RATHER WEAK AS NORTHERN STREAM SHORTWAVE ENERGY PASSES TO OUR NORTH. THUS PCPN SHOULD BE LIGHT AT BEST WITH MANY AREAS REMAINING DRY...ESP ACROSS OUR SOUTHERN COUNTIES. THE SYSTEM FOR NEXT WEEKEND A LITTLE MORE ROBUST SO A BETTER SHOT AREA WIDE FOR RAIN/SNOW SHOWERS. IN BETWEEN (WED AFTERNOON THROUGH FRIDAY MORNING) GENERALLY HIGH PRESSURE WITH CLEAR/PTLY CLOUDY SKIES AND DRY WEATHER EXPECTED. HIGHS GENERALLY IN THE 40S THROUGH THE PERIOD WITH A SPOT 50 HERE AND THERE POSSIBLE WED-FRI. OVERNIGHT LOWS GENERALLY FROM 25 TO 35 THOUGH MAINLY 20S WED NT/THU NT WITH AFOREMENTIONED HIGH PRESSURE IN CONTROL AND BETTER SHOT AT PARTIALLY CLEAR SKIES. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...WIDESPREAD MVFR/IFR ACROSS THE REGION IN MODERATE TO HEAVY MIXED PCPN AND/OR RAIN AS LOW PRESSURE ALONG THE NORTHERN MID-ATLANTIC COAST DRAWS COPIOUS MOISTURE NORTHWARD. TERMINAL SPECIFIC DETAILS BELOW... KBTV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD W/BRIEF IFR POSSIBLE. WINDS NORTH/NORTHWESTERLY 7-15 KTS. KMPV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. IFR/MVFR CONDS EXPECTED THROUGH THE PERIOD. WINDS LGT AND VRB THROUGH 12Z...THEN NORTH/NORTHWESTERLY 6-12 KTS THEREAFTER. KRUT...PERIODS OF LIGHT RAIN...TAPERING TO SHOWERS BY 18Z. MIX OF VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD. WINDS EASTERLY 8 TO 15 KTS WITH GUSTS TO 20 KTS...TRENDING NORTH TO NORTHEASTERLY AFTER 12Z. KPBG...LIGHT TO MODERATE SNOW THROUGH 10-12Z...THEN MIXING WITH SLEET. IFR LIKELY THROUGH 15Z...TRENDING MVFR THEREAFTER. SOME MIX WITH RAIN ALSO POSSIBLE AFTER 16Z BEFORE PCPN TAPERS TO SHOWERS. WINDS NORTHERLY 10-18 KTS AND TRENDING GUSTY TO 25 KTS THIS AFTERNOON. KMSS...LIGHT TO MODERATE SNOW EXPECTED THROUGH MUCH OF THE PERIOD...TAPERING TO SCT SHSN AFTER 00Z MONDAY. IFR FLYING CONDS EXPECTED THROUGH AFTERNOON...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 15 TO 22 KTS WITH GUSTS TO 30 KTS EXPECTED...ABATING SLIGHTLY TOWARD EVENING. CONSIDERABLE BLSN LIKELY. KSLK...LIGHT/MODERATE SNOW EXPECTED WITH SOME MIX OF FZRA/PL POSSIBLE...TAPERING TO SCT SHSN/SHRA AFTER 18Z. WIDESPREAD IFR...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 6-12 KTS...OCCNL GUSTY TO 20KTS THIS AFTERNOON. OUTLOOK 06Z MONDAY THROUGH THURSDAY... 06Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO EAST AS LIGHT RAIN/SNOW TAPERS OFF. BEST SHOT AT CONTINUED LIGHT PCPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH CONTINUED UNCERTAINTY FURTHER EAST. 18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE. 00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD FRONT CROSSES REGION. 00Z THURSDAY ONWARD...VFR W/MVFR PSBL LATE THURSDAY AS WARM FRONT APPROACHES FROM SW...BRINGING PRECIP SOUTH TO NORTH. && .HYDROLOGY... AS OF 340 AM EDT SUNDAY...COMPLEX HYDRO SITUATION WILL DEVELOP ACROSS OUR SOUTHERN WATERSHEDS TODAY WHERE A SOAKING RAINFALL ON THE ORDER OF 1-1.75 INCHES WILL OCCUR. THIS IS A BLENDED MULTI- MODEL SOLUTION WHICH APPEARS THE BEST COURSE FOR NOW GIVEN CURRENT OBSERVATIONAL DATA. USING THIS QPF AND ALLOWING FOR 0.01-0.03 INCHES OF SWE MELT PER HOUR INDICATES MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET TODAY. WHILE WIDESPREAD OPEN WATER FLOODING IS NOT EXPECTED GIVEN AT LEAST SOME ABSORPTION OF THE RAIN INTO THE EXISTENT "NON-RIPE" SNOWPACK...THESE RISES MAY BE MORE THAN SUFFICIENT TO PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS. THIS SEEMS LOGICAL SEEING ICE MOVEMENT/BREAKUP TYPICALLY OCCURS WHEN RISES ARE ON THE ORDER OF 3X THE ICE THICKNESS. WHILE WE`LL HAVE TO WAIT AND SEE HOW THIS COMPLEX SITUATION PANS OUT...CERTAINLY SOMETHING TO KEEP A CLOSE EYE ON TODAY INTO TONIGHT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR VTZ001>006-009-016-017. FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019. WINTER WEATHER ADVISORY UNTIL 11 AM EDT MONDAY FOR VTZ007-008- 010-012-018-019. WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM EDT MONDAY FOR VTZ011. NY...WINTER STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ030- 031-034. WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ026>029-035-087. && $$ SYNOPSIS...LAHIFF NEAR TERM...LAHIFF SHORT TERM...LAHIFF LONG TERM...JMG AVIATION...BANACOS/JMG HYDROLOGY...JMG
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
340 AM EDT SUN MAR 30 2014 .SYNOPSIS... A MOISTURE LADEN STORM SYSTEM WILL IMPACT OUR REGION TONIGHT INTO SUNDAY. THIS SYSTEM WILL PRODUCE A MIXTURE OF RAIN...SLEET AND SNOW...WITH SOME ICE ACCUMULATION ACROSS PORTIONS OF EASTERN VERMONT. HEAVY RAINFALL ACROSS SOUTHERN VERMONT...COMBINED WITH MELTING SNOW WILL PRODUCE INCREASED HYDRO CONCERNS OVER THE WEEKEND. && .NEAR TERM /UNTIL 2 PM THIS AFTERNOON/... AS OF 840 PM EDT SATURDAY...UPDATED TO UPGRADE PARTS OF THE NORTHERN ADIRONDACK MOUNTAINS TO WINTER STORM WARNINGS. PRECIPITATION HAS NOW MADE IT INTO PORTIONS OF SOUTHERN VERMONT...ADIRONDACKS...AND INTO WATERTOWN NEW YORK. SHOULD CONTINUE TO SEE IT MOVE NORTHWARD INTO CENTRAL VERMONT BETWEEN 9-10 PM...THE BURLINGTON AREA 10-11 PM..AND ACROSS THE ENTIRE NORTH COUNTRY BY MIDNIGHT. HEAVIEST PRECIP STILL APPEARS IT WILL FALL BETWEEN 06Z AND 12Z. VERTICAL TEMPERATURE PROFILES REMAIN VERY TRICKY WITH NEARLY ISOTHERMAL PROFILE FROM THE SURFACE TO 825-MB CENTERED AROUND 0C. DYNAMIC/EVAPORATIONAL COOLING SHOULD HELP TO COOL THE COLUMN AT LEAST IN HEAVIER PRECIPITATION IN THE ADVISORY AND WARNING AREA...ESPECIALLY NORTHERN NEW YORK. ONE CAVEAT TO NOTE...LATEST RAP SOLUTIONS ARE CONSIDERABLY WARMER AND WOULD FAVOR MORE RAIN OVER SNOW/SLEET FOR MUCH OF VERMONT. STILL THINK THAT ENOUGH COOLING TO TAKE PLACE FOR A GENERAL 2-5" OF SNOW FOR THE NORTHERN HALF OF VERMONT. IN THE ADIRONDACKS...TEMPERATURES HAVE ALREADY FALLEN TO 32 DEGREES OR LOWER...WITH LOW LEVEL COLD NORTHEAST FLOW LOCKED IN. WITH AT LEAST 0.75" OF LIQUID EQUIVALENT PRECIPITATION HEADED INTO SUB-FREEZING AIR...FELT IT WAS NECESSARY TO UPGRADE TO WARNINGS THERE. EVEN THE WARMER RAP SOLUTIONS ARE COLD ENOUGH FOR ALL FROZEN PRECIPITATION OVER THE ADIRONDACKS. EXPECTING PRIMARILY SNOW...ALTHOUGH THE TEMPERATURE PROFILE IS STILL QUITE MARGINAL SO SOME SLEET/RAIN/FREEZING RAIN MIX STILL LIKELY AT TIMES. LOOKING AT 4-8" THERE WITH THE POSSIBILITY OF SOME LOCALLY HIGHER AMOUNTS. COLD NORTHEAST WINDS ALSO LOCKED INTO THE SAINT LAWRENCE VALLEY...BUT BOUNDARY LAYER WILL BE MORE MARGINAL AS ITS A DEEPER VALLEY...AND PRECIP AMOUNTS LIGHTER...SO ADVISORY LEVEL SNOWS OF 3-5" STILL LOOK GOOD. ELSEWHERE ACROSS SOUTHERN VERMONT...PRECIPITATION WILL FALL AS MAINLY RAIN...WITH SOME MIXED SNOW/SLEET/FREEZING RAIN. SNOW ACCUMULATIONS WILL GENERALLY BE LESS THAN ONE INCH...WITH SOME ICE ACCRUAL OF UP TO A TENTH OF AN INCH IN ISOLATED LOCATIONS. BIGGEST CONCERN THERE WILL BE 1-1.5" OF RAIN WHICH MAY LEAD TO ICE JAM FLOODING. && .SHORT TERM /2 PM THIS AFTERNOON THROUGH TUESDAY/... AS OF 402 PM EDT SATURDAY...FOR SUNDAY NIGHT INTO MONDAY...WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ANOTHER ROUND OF MIXED PRECIPITATION. THIS DUE TO SHORTWAVE ROTATING AROUND THE SLOWLY DEPARTING UPPER LOW. MODELS HAVE TRENDED FURTHER WEST WITH THE UPPER LOW AND SHORTWAVE...SO CONFIDENCE INCREASING THAT WE WILL AT LEAST SEE SOME LIGHT SLEET AND OR RAIN/FREEZING RAIN/DRIZZLE SUNDAY NIGHT INTO MONDAY. GREATEST CHANCES WILL BE OVER EASTERN ZONES DUE PROXIMITY WITH UPPER LOW. TEMPS MARGINAL FOR SNOW/RAIN OR MIXED PRECIPITATION ONCE AGAIN. LOOK FOR LOWS SUNDAY NIGHT IN THE MID 20S TO LOWER 30S AND HIGHS MONDAY NEAR 40. SLOW IMPROVEMENT MONDAY NIGHT AS THE UPPER LOW EXITS TO THE EAST. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 340 AM EDT SUNDAY...SEASONABLE EARLY SPRING TEMPERATURES ALONG WITH PERIODIC CHANCES OF RAIN OR SNOW SHOWERS WILL BE THE RULE DURING THE MIDDLE TO LATER PORTIONS OF NEXT WEEK. BEST SHOT AT PCPN WILL OCCUR TUE NT/WED MORNING...THEN AGAIN BY NEXT WEEKEND. THE MID-WEEK SYSTEM WILL BE RATHER WEAK AS NORTHERN STREAM SHORTWAVE ENERGY PASSES TO OUR NORTH. THUS PCPN SHOULD BE LIGHT AT BEST WITH MANY AREAS REMAINING DRY...ESP ACROSS OUR SOUTHERN COUNTIES. THE SYSTEM FOR NEXT WEEKEND A LITTLE MORE ROBUST SO A BETTER SHOT AREA WIDE FOR RAIN/SNOW SHOWERS. IN BETWEEN (WED AFTERNOON THROUGH FRIDAY MORNING) GENERALLY HIGH PRESSURE WITH CLEAR/PTLY CLOUDY SKIES AND DRY WEATHER EXPECTED. HIGHS GENERALLY IN THE 40S THROUGH THE PERIOD WITH A SPOT 50 HERE AND THERE POSSIBLE WED-FRI. OVERNIGHT LOWS GENERALLY FROM 25 TO 35 THOUGH MAINLY 20S WED NT/THU NT WITH AFOREMENTIONED HIGH PRESSURE IN CONTROL AND BETTER SHOT AT PARTIALLY CLEAR SKIES. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...WIDESPREAD MVFR/IFR ACROSS THE REGION IN MODERATE TO HEAVY MIXED PCPN AND/OR RAIN AS LOW PRESSURE ALONG THE NORTHERN MID-ATLANTIC COAST DRAWS COPIOUS MOISTURE NORTHWARD. TERMINAL SPECIFIC DETAILS BELOW... KBTV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD W/BRIEF IFR POSSIBLE. WINDS NORTH/NORTHWESTERLY 7-15 KTS. KMPV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. IFR/MVFR CONDS EXPECTED THROUGH THE PERIOD. WINDS LGT AND VRB THROUGH 12Z...THEN NORTH/NORTHWESTERLY 6-12 KTS THEREAFTER. KRUT...PERIODS OF LIGHT RAIN...TAPERING TO SHOWERS BY 18Z. MIX OF VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD. WINDS EASTERLY 8 TO 15 KTS WITH GUSTS TO 20 KTS...TRENDING NORTH TO NORTHEASTERLY AFTER 12Z. KPBG...LIGHT TO MODERATE SNOW THROUGH 10-12Z...THEN MIXING WITH SLEET. IFR LIKELY THROUGH 15Z...TRENDING MVFR THEREAFTER. SOME MIX WITH RAIN ALSO POSSIBLE AFTER 16Z BEFORE PCPN TAPERS TO SHOWERS. WINDS NORTHERLY 10-18 KTS AND TRENDING GUSTY TO 25 KTS THIS AFTERNOON. KMSS...LIGHT TO MODERATE SNOW EXPECTED THROUGH MUCH OF THE PERIOD...TAPERING TO SCT SHSN AFTER 00Z MONDAY. IFR FLYING CONDS EXPECTED THROUGH AFTERNOON...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 15 TO 22 KTS WITH GUSTS TO 30 KTS EXPECTED...ABATING SLIGHTLY TOWARD EVENING. CONSIDERABLE BLSN LIKELY. KSLK...LIGHT/MODERATE SNOW EXPECTED WITH SOME MIX OF FZRA/PL POSSIBLE...TAPERING TO SCT SHSN/SHRA AFTER 18Z. WIDESPREAD IFR...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 6-12 KTS...OCCNL GUSTY TO 20KTS THIS AFTERNOON. OUTLOOK 06Z MONDAY THROUGH THURSDAY... 06Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO EAST AS LIGHT RAIN/SNOW TAPERS OFF. BEST SHOT AT CONTINUED LIGHT PCPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH CONTINUED UNCERTAINTY FURTHER EAST. 18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE. 00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD FRONT CROSSES REGION. 00Z THURSDAY ONWARD...VFR W/MVFR PSBL LATE THURSDAY AS WARM FRONT APPROACHES FROM SW...BRINGING PRECIP SOUTH TO NORTH. && .HYDROLOGY... AS OF 340 AM EDT SUNDAY...COMPLEX HYDRO SITUATION WILL DEVELOP ACROSS OUR SOUTHERN WATERSHEDS TODAY WHERE A SOAKING RAINFALL ON THE ORDER OF 1-1.75 INCHES WILL OCCUR. THIS IS A BLENDED MULTI- MODEL SOLUTION WHICH APPEARS THE BEST COURSE FOR NOW GIVEN CURRENT OBSERVATIONAL DATA. USING THIS QPF AND ALLOWING FOR 0.01-0.03 INCHES OF SWE MELT PER HOUR INDICATES MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET TODAY. WHILE WIDESPREAD OPEN WATER FLOODING IS NOT EXPECTED GIVEN AT LEAST SOME ABSORPTION OF THE RAIN INTO THE EXISTENT "NON-RIPE" SNOWPACK...THESE RISES MAY BE MORE THAN SUFFICIENT TO PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS. THIS SEEMS LOGICAL SEEING ICE MOVEMENT/BREAKUP TYPICALLY OCCURS WHEN RISES ARE ON THE ORDER OF 3X THE ICE THICKNESS. WHILE WE`LL HAVE TO WAIT AND SEE HOW THIS COMPLEX SITUATION PANS OUT...CERTAINLY SOMETHING TO KEEP A CLOSE EYE ON TODAY INTO TONIGHT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR VTZ001>010-012-016>019. FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019. NY...WINTER STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ030- 031-034. WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ026>029-035-087. && $$ SYNOPSIS...RJS NEAR TERM...MUCCILLI SHORT TERM...RJS LONG TERM...JMG AVIATION...JMG/BANACOS HYDROLOGY...JMG
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
133 AM EDT SUN MAR 30 2014 .SYNOPSIS... A MOISTURE LADEN STORM SYSTEM WILL IMPACT OUR REGION TONIGHT INTO SUNDAY. THIS SYSTEM WILL PRODUCE A MIXTURE OF RAIN...SLEET AND SNOW...WITH SOME ICE ACCUMULATION ACROSS PORTIONS OF EASTERN VERMONT. HEAVY RAINFALL ACROSS SOUTHERN VERMONT...COMBINED WITH MELTING SNOW WILL PRODUCE INCREASED HYDRO CONCERNS OVER THE WEEKEND. && .NEAR TERM /UNTIL 2 PM THIS AFTERNOON/... AS OF 840 PM EDT SATURDAY...UPDATED TO UPGRADE PARTS OF THE NORTHERN ADIRONDACK MOUNTAINS TO WINTER STORM WARNINGS. PRECIPITATION HAS NOW MADE IT INTO PORTIONS OF SOUTHERN VERMONT...ADIRONDACKS...AND INTO WATERTOWN NEW YORK. SHOULD CONTINUE TO SEE IT MOVE NORTHWARD INTO CENTRAL VERMONT BETWEEN 9-10 PM...THE BURLINGTON AREA 10-11 PM..AND ACROSS THE ENTIRE NORTH COUNTRY BY MIDNIGHT. HEAVIEST PRECIP STILL APPEARS IT WILL FALL BETWEEN 06Z AND 12Z. VERTICAL TEMPERATURE PROFILES REMAIN VERY TRICKY WITH NEARLY ISOTHERMAL PROFILE FROM THE SURFACE TO 825-MB CENTERED AROUND 0C. DYNAMIC/EVAPORATIONAL COOLING SHOULD HELP TO COOL THE COLUMN AT LEAST IN HEAVIER PRECIPITATION IN THE ADVISORY AND WARNING AREA...ESPECIALLY NORTHERN NEW YORK. ONE CAVEAT TO NOTE...LATEST RAP SOLUTIONS ARE CONSIDERABLY WARMER AND WOULD FAVOR MORE RAIN OVER SNOW/SLEET FOR MUCH OF VERMONT. STILL THINK THAT ENOUGH COOLING TO TAKE PLACE FOR A GENERAL 2-5" OF SNOW FOR THE NORTHERN HALF OF VERMONT. IN THE ADIRONDACKS...TEMPERATURES HAVE ALREADY FALLEN TO 32 DEGREES OR LOWER...WITH LOW LEVEL COLD NORTHEAST FLOW LOCKED IN. WITH AT LEAST 0.75" OF LIQUID EQUIVALENT PRECIPITATION HEADED INTO SUB-FREEZING AIR...FELT IT WAS NECESSARY TO UPGRADE TO WARNINGS THERE. EVEN THE WARMER RAP SOLUTIONS ARE COLD ENOUGH FOR ALL FROZEN PRECIPITATION OVER THE ADIRONDACKS. EXPECTING PRIMARILY SNOW...ALTHOUGH THE TEMPERATURE PROFILE IS STILL QUITE MARGINAL SO SOME SLEET/RAIN/FREEZING RAIN MIX STILL LIKELY AT TIMES. LOOKING AT 4-8" THERE WITH THE POSSIBILITY OF SOME LOCALLY HIGHER AMOUNTS. COLD NORTHEAST WINDS ALSO LOCKED INTO THE SAINT LAWRENCE VALLEY...BUT BOUNDARY LAYER WILL BE MORE MARGINAL AS ITS A DEEPER VALLEY...AND PRECIP AMOUNTS LIGHTER...SO ADVISORY LEVEL SNOWS OF 3-5" STILL LOOK GOOD. ELSEWHERE ACROSS SOUTHERN VERMONT...PRECIPITATION WILL FALL AS MAINLY RAIN...WITH SOME MIXED SNOW/SLEET/FREEZING RAIN. SNOW ACCUMULATIONS WILL GENERALLY BE LESS THAN ONE INCH...WITH SOME ICE ACCRUAL OF UP TO A TENTH OF AN INCH IN ISOLATED LOCATIONS. BIGGEST CONCERN THERE WILL BE 1-1.5" OF RAIN WHICH MAY LEAD TO ICE JAM FLOODING. && .SHORT TERM /2 PM THIS AFTERNOON THROUGH MONDAY NIGHT/... AS OF 402 PM EDT SATURDAY...FOR SUNDAY NIGHT INTO MONDAY...WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ANOTHER ROUND OF MIXED PRECIPITATION. THIS DUE TO SHORTWAVE ROTATING AROUND THE SLOWLY DEPARTING UPPER LOW. MODELS HAVE TRENDED FURTHER WEST WITH THE UPPER LOW AND SHORTWAVE...SO CONFIDENCE INCREASING THAT WE WILL AT LEAST SEE SOME LIGHT SLEET AND OR RAIN/FREEZING RAIN/DRIZZLE SUNDAY NIGHT INTO MONDAY. GREATEST CHANCES WILL BE OVER EASTERN ZONES DUE PROXIMITY WITH UPPER LOW. TEMPS MARGINAL FOR SNOW/RAIN OR MIXED PRECIPITATION ONCE AGAIN. LOOK FOR LOWS SUNDAY NIGHT IN THE MID 20S TO LOWER 30S AND HIGHS MONDAY NEAR 40. SLOW IMPROVEMENT MONDAY NIGHT AS THE UPPER LOW EXITS TO THE EAST. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 325 PM EDT SATURDAY...DRY START TO THE PERIOD TUESDAY BEFORE UPPER LVL TROUGH...ASSOCIATED WITH CLOSED SFC LOW...TRAVELS FROM THE NRN GREAT LAKES NEWD NEAR JAMES BAY BY MID WEDNESDAY. THIS LOW WILL HAVE A WEAK FRONTAL BOUNDARY DRAPED SOUTH...WHICH WILL BRING LOW CHC OF SHOWERS TO THE NORTH COUNTRY TUESDAY NGT INTO WEDNESDAY...AS THIS BOUNDARY WILL HAVE LIMITED MOISTURE AND MAIN UPPER LVL ENERGY WILL BE FAR NORTH OF THE FA. FOR ANY PRECIP THAT DOES OCCUR...TUESDAY NGT WILL SEE SOME SNOW...BUT WARMING TEMPS ON WEDNESDAY WILL TRANSITION SN INTO RA BEFORE TAPERING OFF. ANOTHER SYSTEM APPROACHING FROM CENTRAL USA WILL BRING WARM FRONT TO THE NE LATE THURSDAY INTO FRIDAY. GFS AND ECMWF DIFFER WITH ECMWF PERSISTING WITH RIDGE. THIS WOULD KEEP THREAT OF PRECIP TO OUR SOUTH THRU LATE FRIDAY. MUCH UNCERTAINTY FOR THE LATTER HALF OF THE WEEK GOING INTO THE WKND. TEMPS THROUGHOUT THE PERIOD WILL BE NEAR NORMAL WITH MAX TEMPS IN THE 40S IN THE VALLEYS AND 30S IN THE MTNS. MIN TEMPS WILL BE IN THE U20S-L30S IN THE VALLEYS AND UPPER TEENS TO L20S IN THE MTNS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...WIDESPREAD MVFR/IFR ACROSS THE REGION IN MODERATE TO HEAVY MIXED PCPN AND/OR RAIN AS LOW PRESSURE ALONG THE NORTHERN MID-ATLANTIC COAST DRAWS COPIOUS MOISTURE NORTHWARD. TERMINAL SPECIFIC DETAILS BELOW... KBTV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD W/BRIEF IFR POSSIBLE. WINDS NORTH/NORTHWESTERLY 7-15 KTS. KMPV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. IFR/MVFR CONDS EXPECTED THROUGH THE PERIOD. WINDS LGT AND VRB THROUGH 12Z...THEN NORTH/NORTHWESTERLY 6-12 KTS THEREAFTER. KRUT...PERIODS OF LIGHT RAIN...TAPERING TO SHOWERS BY 18Z. MIX OF VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD. WINDS EASTERLY 8 TO 15 KTS WITH GUSTS TO 20 KTS...TRENDING NORTH TO NORTHEASTERLY AFTER 12Z. KPBG...LIGHT TO MODERATE SNOW THROUGH 10-12Z...THEN MIXING WITH SLEET. IFR LIKELY THROUGH 15Z...TRENDING MVFR THEREAFTER. SOME MIX WITH RAIN ALSO POSSIBLE AFTER 16Z BEFORE PCPN TAPERS TO SHOWERS. WINDS NORTHERLY 10-18 KTS AND TRENDING GUSTY TO 25 KTS THIS AFTERNOON. KMSS...LIGHT TO MODERATE SNOW EXPECTED THROUGH MUCH OF THE PERIOD...TAPERING TO SCT SHSN AFTER 00Z MONDAY. IFR FLYING CONDS EXPECTED THROUGH AFTERNOON...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 15 TO 22 KTS WITH GUSTS TO 30 KTS EXPECTED...ABATING SLIGHTLY TOWARD EVENING. CONSIDERABLE BLSN LIKELY. KSLK...LIGHT/MODERATE SNOW EXPECTED WITH SOME MIX OF FZRA/PL POSSIBLE...TAPERING TO SCT SHSN/SHRA AFTER 18Z. WIDESPREAD IFR...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 6-12 KTS...OCCNL GUSTY TO 20KTS THIS AFTERNOON. OUTLOOK 06Z MONDAY THROUGH THURSDAY... 06Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO EAST AS LIGHT RAIN/SNOW TAPERS OFF. BEST SHOT AT CONTINUED LIGHT PCPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH CONTINUED UNCERTAINTY FURTHER EAST. 18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE. 00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD FRONT CROSSES REGION. 00Z THURSDAY ONWARD...VFR W/MVFR PSBL LATE THURSDAY AS WARM FRONT APPROACHES FROM SW...BRINGING PRECIP SOUTH TO NORTH. && .HYDROLOGY... AS OF 325 PM EDT SATURDAY...PRECIPITATION WILL BEGIN TO EDGE INTO SOUTHERN VERMONT LATE THIS AFTN...PROGRESSING NORTHWARD THROUGHOUT THE EVENING. THIS PRECIPITATION IS EXPECTED TO CONTINUE THROUGH SUNDAY NIGHT...RESULTING IN OUR SOUTHERN WATERSHEDS RECEIVING THE MOST RAINFALL ON THE ORDER OF 1-2 INCHES. AREAS FURTHER NORTH AND WEST WILL SEE MORE OF A MIXED PRECIPITATION EVENT...WITH LESSER RAINFALL AMOUNTS. WITH SOUTHERN WATERSHEDS RECEIVING MOSTLY RAIN...EXPECT SNOWPACK TO ABSORB SOME OF THIS RAINFALL AS TEMPERATURES WILL GENERALLY BE IN THE MID TO UPPER 30S THROUGHOUT THE EVENT...LEADING TO LIMITED MELTING OF SNOWPACK. ONLY A FEW HUNDREDTHS OF AN INCH OF SNOW WATER MELT PER HOUR EXPECTED ON TOP OF RAINFALL WILL RESULT IN MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET SUNDAY MORNING/AFTERNOON. ENSEMBLE FORECASTS INDICATE NO RIVER FLOODING EXPECTED....BUT WATER LEVEL RISES MAY BE MORE THAN SUFFICIENT TO PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS. WILL KEEP FLOOD WATCH IN EFFECT FOR CENTRAL AND SOUTHERN VERMONT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR VTZ001>010-012-016>019. FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019. NY...WINTER STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ030- 031-034. WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ026>029-035-087. && $$ SYNOPSIS...RJS NEAR TERM...MUCCILLI SHORT TERM...RJS LONG TERM...KGM AVIATION...JMG/BANACOS HYDROLOGY...KGM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
410 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COLD FRONT WILL MOVE OFFSHORE LATE TONIGHT. A SURFACE TROUGH WILL LINGER JUST WEST OF THE AREA INTO MONDAY. WEAK HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND TUESDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY. ANOTHER COLD WILL APPROACH THE AREA BY LATE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1230 AM SUNDAY...UPDATED TO REDUCE POPS TO 30% FOR COASTAL PLAINS OVERNIGHT AND 20% REST OF AREA. DRY SLOT WILL KEEP MOST OF AREA DRY REST OF NIGHT BUT SCT SHOWERS WILL AFFECT COASTAL PLAINS WITH CONVERGENCE JUST AHEAD OF FRONT. TORNADO WATCH WAS CANCELLED AT 10 PM. MINOR ADJUSTMENTS TO TEMPS AND SKY COVER. /PREVIOUS DISCUSSION/ AS OF 920 PM SATURDAY...A TORNADO WATCH REMAINS IN EFFECT FOR THE WESTERN PORTIONS OF EASTERN NC (MAINLY WEST OF HIGHWAY 17) UNTIL 1 AM. HAVE BEEN WATCHING A PERSISTENT SUPERCELL THUNDERSTORM WITH A DEEP AND PERSISTENT MESCALINE MOVING THROUGH CENTRAL NC SINCE 730 PM. THIS STORM WILL REMAIN NW OF OUR AREA. TO THE SOUTH OF THIS SYSTEM ADDITIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WERE DEVELOPING. THE HRRR MODEL BRINGS THIS CONVECTION INTO OUR PORTION OF THE COASTAL PLAIN AROUND 11 PM SO WILL CONTINUE TO MONITOR. SO FAR STORMS HAVE NOT WEAKENED WITH LOSS OF HEATING A SIGNAL THAT THEY ARE BEING DYNAMICALLY FORCED. WILL CONTINUE TO KEEP POPS IN THE CHANCE RANGE AS THE COVERAGE IN THE HIGH RESOLUTION MODELS REMAINS SCATTERED. LATE TONIGHT DRY SLOTTING SHOULD END ANY CHANCE OF PRECIPITATION UNTIL LATER SUNDAY WHEN THE UPPER LEVEL LOW MOVES THROUGH. USED A BLEND OF THE ECMWF/MET MOS FOR LOWS WITH READINGS IN THE UPPER 40S/LOWER 50S EXPECTED. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/... AS OF 315 PM SATURDAY...WILL HAVE A BIT OF A LULL IN PRECIPITATION DURING THE MORNING HOURS ON SUNDAY...BUT AS UPPER LOW CROSSES TO OUR NORTH NEAR THE NORTH CAROLINA/VIRGINIA BORDER...THE STEEP LAPSE RATES AND MODEST MOISTURE WILL LEAD TO A HIGH CHANCE OF SHOWERS SUNDAY AFTERNOON. WITH GOOD COLD AIR ADVECTION...TEMPERATURES WILL ONLY RECOVER ABOUT 5 TO 7 DEGREES AND WILL FOLLOW THE COOLER NAM MOS GUIDANCE SUNDAY SHOWING HIGH TEMPERATURES IN THE LOW/MID 50S WITH GUSTY W/WNW WINDS. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 4 AM SUN...UPR LOW WILL PIVOT EAST OF THE NC WATERS BY MONDAY...LEAVING IN ITS WAKE STRONG SUBSIDENCE AS HIGH PRES SFC AND ALOFT BUILDS IN. ATMS COLUMN WILL BE EXTREMELY DRY PER SOUNDINGS ~0.25 INCH PWATS. THIS IS BELOW THE 25TH PERCENTILE FOR LATE MARCH. SKIES WILL BE SUNNY...WITH GUSTY NW WINDS AS GRADIENT REMAINS BETWEEN DEPARTING LOW AND BUILDING HIGH. A FAIRLY HIGH TEMP GRADIENT ACROSS THE FA...WITH LOW LEVEL THICKNESSES SUPPORTIVE OF HIGHS IN THE LOW 70S WEST...TO 50S ALONG THE OBX. STEEP LOW LEVEL LAPSE RATES WILL PROMOTE EFFICIENT MIXING WITH DRY AIR ALOFT MIXING TO THE SFC. WILL HAVE TO WATCH FOR FIRE WEATHER CONCERNS AS MIN RH VALS PLUMMET TO THE 20-30 PERCENTILE RANGE BY MON AFTERNOON WITH A GUSTY NW WIND. HIGH WILL BUILD IN MON NIGHT WITH WINDS QUICKLY DIMINISHING BY NIGHTFALL WITH LOSS OF TURBULENT MIXING. WITH CLR SKIES...CALM WINDS...AND DRY ATMS...WILL SEE LOWS DROP BACK TO THE UPR 30S/LOW 40S MOST AREAS AWAY FROM THE BEACHES. LARGE DIURNAL SWING ON TUE AS THICKNESSES BUILD FURTHER AND DRY ATMOSPHERE REMAINS DUE TO ZONAL FLOW ALOFT. HIGHS WILL REACH WELL INTO THE 70S INLAND TO 60S COAST. LARGE DIURNAL SEESAW CONTINUES TUE NIGHT AS DECOUPLING OCCURS ONCE AGAIN...AND WITH CONTINUED DRY ATMS TEMPS FALL BACK TO THE 40S. THICKNESSES BUILD FURTHER ON WED AND ECM ENSMOS IN GOOD AGREEMENT WITH LOCAL LOW LEVEL THICKNESS STUDY IN HIGHS IN THE UPPER 70S...60S BEACHES. LOWS DROP BACK TO ~50 WED NIGHT AS SPRAWLING DRY HIGH PRES REMAINS LOCKED IN ACROSS SE CONUS. THUR AND FRI LOOK TO BE THE WARMEST DAYS OF THE WEEK WITH HIGHS REACHING OR PERHAPS EXCEEDING 80 AS 1000-850MB THICKNESSES APPROACH 1390M. DEWPOINTS WILL BE ON THE RISE DURING THIS TIME PERIOD SO OVERNIGHT LOWS WILL BE WARMER GENERALLY IN THE MID/UPR 50S. MODEL DIFFERENCES TOWARDS THE WEEKEND COME INTO PLAY...AS IS EXPECTED THIS FAR OUT. THE ECM KEEPS THE SE CONUS RIDGE IN PLACE WHILE PUSHING A WEAK COLD FRONT INTO THE REGION...AND KEEPING BEST DYNAMICS WELL TO THE NORTH AS STORM TRACK REMAINS WELL NORTH OF THE AREA. MEANWHILE...THE DETERMINISTIC 30/00Z GFS INDICATES A STRONGER COLD FRONT PUSHING THROUGH FRI NIGHT/EARLY SAT WITH MORE AMPLIFIED LONG WAVE TROFINESS ACROSS THE E CONUS. THIS SCENARIO HOWEVER LACKS SUPPORT FROM THE NCEP ENSEMBLE MEAN...WHICH INDICATES A LESS AMPLIFIED TROUGH ACROSS THE E CONUS. THEREFORE...HAVE ONLY INDICATED SMALL POPS LATE FRI INTO SAT. && .AVIATION /08Z SUNDAY THROUGH FRIDAY/... SHORT TERM /THROUGH 06Z MONDAY/... AS OF 130 AM SUNDAY...CONDITIONS HAVE IMPROVED TO VFR ALL BUT KPGV WHERE MVFR SCU STILL LINGERING. SCU VFR CIGS EXPECTED TO REDEVLOP ALL SITES 09Z-12Z AS UPR LOW MOVES INTO AREA FROM W. LOWER MVFR CIGS WILL DEVELOP WITH HEATING BY 15Z WITH SCT SHRA PSBL THROUGH AFTN AS COLD CORE UPR LOW MOVES ACROSS NRN SECTIONS. CLEARING EXPECTED DURING EVENING WITH LOSS OF HEATING. W WINDS WILL GUST UP TO 20-25 KT TODAY...DIMINISING AND BECOME NW THIS EVENING. LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 4 AM SUN...EXCELLENT FLYING CONDITIONS FOR THE LONG TERM AS HIGH PRES WILL BE IN CONTROL. GUSTY NW WINDS WILL CONTINUE ON MONDAY BUT THE REST OF THE WEEK WINDS WILL BE LIGHT. NOT MUCH CHANCE FOR EVENT RADIATION FOG DURING THE OVERNIGHT HOURS THIS COMING WEEK AS ATMOSPHERE WILL BE VERY DRY. BETTER CHANCE FOR FOG AT NIGHT LATER IN THE WEEK (THUR/FRI) AS DEWPOINT RISE. && .MARINE... SHORT TERM /TONIGHT AND SUNDAY/... AS OF 1230 AM SUNDAY...NO CHANGES WITH UPDATE. /PREVIOUS DISCUSSION/ AS OF 920 PM SATURDAY...NO CHANGES TO PREVIOUS FORECAST THINKING OTHER THAN TO EXTEND THE ADVISORIES FOR THE SOUNDS THROUGH EARLY MONDAY. GUSTY SE/S WINDS WILL CONTINUE TONIGHT AND HAVE ADDED THE ALBEMARLE SOUND TO THE SMALL CRAFT ADVISORY THAT WILL REMAIN IN EFFECT UNTIL 5 AM SUNDAY. WILL INITIALIZE WINDS AT 20 TO 25 KNOTS FOR ALL WATERS...EXCEPT 25 TO 30 KNOTS OVER THE OREGON INLET TO OCRACOKE LEG WHERE WINDS CONTINUE TO BE STRONGEST. THESE WINDS SHOULD SETTLE DOWN AFTER MIDNIGHT AS WINDS VEER TO MORE SW LATE. PER LATEST NWPS WAVE MODEL...SEAS OF 9 TO 13 FEET WILL PREVAIL OVER THE NORTHERN AND CENTRAL WATERS WITH GENERALLY 7 TO 10 FEET OVER SOUTHERN PORTIONS...WITH A SLIGHT DROP IN THE MORE WESTERLY FLOW EXPECTED DURING THE DAY ON SUNDAY. LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 4 AM SUN...MONDAY WILL CONTINUE TO BE WINDY WITH SCA NW WINDS...THOUGH THESE WINDS WILL WIND DOWN THROUGH THE DAY AS LOW PRES MOVES AWAY FROM THE EASTERN ATLANTIC WATERS. SEAS WILL STILL REMAIN ELEVATED HOWEVER EVEN WHEN WINDS DROP BELOW 25 KT...AS LINGERING LONG PERIOD SWELL DOMINATES THE NRN/CENTRAL WATERS INTO MON NIGHT. SEAS HERE WILL DROP BELOW 6 FT FINALLY...WITH HIGH PRES BUILDING IN FOR TUE THROUGH MUCH OF NEXT WEEK. THE HIGH WILL BE ANCHORED TO THE SOUTH OF THE AREA...AND THEREFORE WINDS WILL BE SOUTHWEST FOR MUCH OF THE PERIOD...OCNL REACHING 20 KT MID TO LATE WEEK. THIS MAY BRING MARGINAL SCA TO ESPECIALLY THE SOUTHERN/CENTRAL WATERS AS SEAS MAY REACH 6 FT HERE. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...GALE WARNING FROM 2 PM THIS AFTERNOON TO 11 AM EDT MONDAY FOR AMZ135-152-154. SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ130. GALE WARNING FROM 2 PM THIS AFTERNOON TO 8 AM EDT MONDAY FOR AMZ156-158. GALE WARNING FROM 6 PM THIS EVENING TO 11 AM EDT MONDAY FOR AMZ150. && $$ SYNOPSIS...CTC NEAR TERM...CTC/JME SHORT TERM...CTC LONG TERM...TL AVIATION...JME/TL/LEP MARINE...CTC/JME/TL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COLD FRONT WILL SWEEP EAST THROUGH CENTRAL NORTH CAROLINA EARLY THIS MORNING... AND WILL BE FOLLOWED BY BRISK AND GUSTY WINDS FROM THE NORTHWEST PULLING COOLER AIR INTO THE REGION. HIGH PRESSURE WILL BUILD IN FROM THE WEST TONIGHT INTO EARLY NEXT WEEK. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 300 AM SUNDAY... THE PRIMARY WEATHER CONCERN TODAY IS THE STRONG GUSTY NW WINDS AND POTENTIALLY ADVERSE IMPACTS SUCH AS DOWNED BRANCHES AND WEAKLY ROOTED TREES. CURRENTLY... SHORT BANDS OF SHOWERS PRODUCING LOCALLY ENHANCED WINDS CONTINUE TO PIVOT AROUND THE MID LEVEL LOW OVER SW VA THIS MORNING... MAINLY AFFECTING THE NRN CWA AS POCKETS OF VORTICITY STREAK TO THE NNE ON THE SRN/ERN SIDE OF THE LOW. THIS LOW IS EXPECTED TO TRACK EASTWARD ALONG THE NC/VA STATE LINE THROUGH MIDDAY... SHIFTING NE OFF THE TIDEWATER/DELMARVA SHORE DURING THE MID TO LATE AFTERNOON... AND IT`S EXPECTED TO BRING PATCHY SHOWERS (MOVING MORE WEST-TO-EAST) THROUGH MID AFTERNOON ACROSS OUR NRN CWA... WHERE FORECAST SOUNDINGS AND EXTRAPOLATION OF UPSTREAM CONDITIONS SUPPORT A RATHER DEEP LAYER OF MOISTURE AT 850-700 MB. THE COMPARATIVELY DRY AND WELL-MIXED SUBCLOUD LAYER HOWEVER WILL GREATLY LIMIT QPF. REGARDING TODAY`S WIND... THE MSLP GRADIENT BETWEEN THE DEEP SURFACE LOW ANALYZED OVER THE CHESAPEAKE BAY/SRN DELMARVA AND THE INCOMING SURFACE HIGH FROM THE WEST TIGHTENS UP THIS MORNING... AND STATISTICAL GUIDANCE AS WELL AS HIGH-RES MODEL OUTPUT SUCH AS THE HRRR AND LOCAL WRF ALL SUPPORT SUSTAINED WINDS OF 15-25 MPH MAINLY OVER THE WRN AND SRN HALVES OF THE CENTRAL NC FORECAST AREA... AND TRANSPORT OF MOMENTUM WITHIN THE GROWING MIXED LAYER INDICATES GUSTS OF 30-36 KTS OVER THIS SAME AREA. WHILE THESE SPEEDS MAY NOT QUITE REACH OUR WIND ADVISORY CRITERIA EVERYWHERE... THE ANTICIPATED IMPACTS (A FEW DOWNED BRANCHES/TREES AND SPORADIC POWER OUTAGES) WARRANT ISSUANCE OF A WIND ADVISORY... TO BE IN EFFECT FOR AREAS WEST AND SOUTH OF THE TRIANGLE THROUGH MID EVENING (WHEN WINDS ARE EXPECTED TO SUBSIDE). BELOW-NORMAL LOW LEVEL THICKNESSES COMBINED WITH CONSIDERABLE CLOUDINESS PARTICULARLY OVER THE NRN TWO-THIRDS OF THE CWA WILL HOLD TEMPS DOWN TODAY... AND EXPECT HIGHS OF 53-62... AROUND 10-12 DEGREES BELOW NORMAL. THE DEPARTURE OF THE SURFACE AND MID LEVEL LOWS TO OUR NE AFTER NIGHTFALL AND STRONG SUBSIDENCE (100-120 M MID LEVEL HEIGHT RISES) SHOULD FOSTER QUICK CLEARING FROM WSW TO ENE. WINDS WILL DECREASE BUT SHOULD STILL HOLD UP ENOUGH TO KEEP THE LOW LEVELS STIRRED OVERNIGHT... KEEPING TEMPS FROM FALLING DOWN TO THE FORECAST DEW POINTS (WHICH SHOULD FALL TO THE MID 20S TO AROUND 30). AS SUCH... EXPECT LOWS TO STAY ABOVE FREEZING TONIGHT. DESPITE LOWS IN THE MID 30S IN MANY AREAS... THE DRY AIR SHOULD LIMIT FROST DEVELOPMENT TONIGHT... BUT WILL TAKE ANOTHER LOOK AT THIS LATER TODAY. LOWS MAINLY 35-40. -GIH && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 315 AM SUNDAY... PLENTY OF SUNSHINE EXPECTED MONDAY... WITH CONTINUED DRY AIR ADVECTION THROUGH THE COLUMN AND HIGH PRESSURE STARTING TO BUILD IN AT THE SURFACE... AND MID LEVEL RIDGING APPROACHING FROM THE WEST. A BREEZE OUT OF THE NW SHOULD PERSIST BUT NOT NEARLY AS STRONG AS WE SHOULD SEE TODAY. LOW LEVEL THICKNESSES RECOVER NICELY TO NEAR- NORMAL LEVELS MON MORNING AND RISE QUICKLY THROUGH THE DAY... SUPPORTING HIGHS FROM THE UPPER 60S NE TO MID 70S SW... A BIT ABOVE NORMAL FOR THIS TIME OF YEAR. EXPECT GOOD RADIATIONAL COOLING MON NIGHT... ALTHOUGH THE INCREASING SURFACE DEW POINTS MON NIGHT WILL OFFSET THE CALM TO VERY LIGHT WINDS TO KEEP TEMPS FROM FALLING TOO MUCH. LOWS 38-42... JUST SLIGHTLY BELOW NORMAL. -GIH && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 255 AM SUNDAY... A SUBTROPICAL RIDGE WILL DEVELOP OVER THE SOUTHEAST US BY TUESDAY WITH A SURFACE HIGH OFF THE SOUTHEAST COAST. THIS WARM PATTERN...WITH LOW LEVEL THICKNESSES CLIMBING ABOVE 1370M...WILL SUPPORT HIGHS IN THE MID AND UPPER 70S EACH DAY...WITH LOWER 80S NOT OUT OF THE QUESTION ACROSS THE SOUTH AND EAST WEDNESDAY AND THURSDAY. A SHORTWAVE LIFTING THROUGH THE GREAT LAKES REGION WILL SEND A MOSTLY DRY COLD FRONT INTO THE MID-ATLANTIC STATES TUESDAY AFTERNOON...BUT GIVEN THE STRENGTH OF THE RIDGE...EXPECT THIS FRONT OR REMNANT TROUGH TO REMAIN NORTH OF THE AREA. A MORE VIGOROUS SYSTEM IS FORECAST TO LIFT THROUGH THE MIDWEST STATES ON FRIDAY...THOUGH THE GFS AND ECMWF DIFFER REGARDING THE STRENGTH OF THE WAVE AND THE TIMING OF THE ASSOCIATED COLD FRONT. PREFER A SOLUTION SLOWER THAN THE ECMWF ON FRIDAY...BUT NOT AS SLOW AS THE GFS WHICH DOESNT BRING THE FRONT IN UNTIL SATURDAY. NEITHER SOLUTION LOOKS TO DRAW A TON OF MOISTURE FROM THE GULF...SO WILL KEEP POPS CAPPED AT SLIGHT CHANCE NOW BASED ON THE PATTERN AND MODEL DIFFERENCES. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 155 AM SUNDAY... THE BIGGEST AVIATION STORY FOR THE NEXT SEVERAL HOURS IS THE COLD FRONTAL PASSAGE AND RESULTANT SHIFT IN SURFACE WINDS TO WESTERLY THEN NORTHWEST... WITH AN INCREASE TO 15-20 KTS GUSTING TO 25-35 KTS... STRONGEST AFTER 17Z THIS AFTERNOON AS OUR LOW LEVELS MIX MORE DEEPLY. THIS MAY POSE A CROSSWIND THREAT FOR AIRCRAFT AT GSO/RDU/FAY/RWI. CURRENT CIGS ARE MOSTLY VFR... BUT PATCHY SHOWERS ACROSS THE AREA MAY BRIEFLY REDUCE CIGS TO MVFR THROUGH 09Z. OTHERWISE... WITH EARLY-DAY HEATING AND RESIDUAL MOISTURE ALOFT... EXPECT TO SEE A PERIOD OF MVFR CIGS MAINLY AT RDU/RWI BETWEEN 12Z AND 17Z THIS MORNING/MIDDAY. THESE CIGS SHOULD LIFT TO VFR SOON AFTER 17Z. ELSEWHERE... ANY CIGS ARE LIKELY TO BE VFR... AND VSBYS WILL BE VFR AREAWIDE THROUGH TONIGHT. WINDS WILL DECREASE THIS EVENING (AFTER 01Z) TO 10-15 KTS WITH ONLY SPORADIC GUSTS TO 20 KTS FROM THE NW THROUGH THE END OF THE TAF VALID PERIOD. LOOKING BEYOND 06Z TONIGHT: HIGH CONFIDENCE IN VFR CONDITIONS AT ALL SITES THROUGH THURSDAY... AS HIGH PRESSURE BUILDS OVER THE REGION AND REMAINS OVER AND JUST OFF THE SOUTHEAST COAST. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR NCZ007-021>024- 038>040-073>077-083>086-088. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...SMITH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
214 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COLD FRONT WILL MOVE OFFSHORE LATE TONIGHT. A SURFACE TROUGH WILL LINGER JUST WEST OF THE AREA INTO MONDAY. WEAK HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND TUESDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY. ANOTHER COLD WILL APPROACH THE AREA BY LATE WEEK. && .NEAR TERM /THROUGH SUNDAY/... AS OF 1230 AM SUNDAY...UPDATED TO REDUCE POPS TO 30% FOR COASTAL PLAINS OVERNIGHT AND 20% REST OF AREA. DRY SLOT WILL KEEP MOST OF AREA DRY REST OF NIGHT BUT SCT SHOWERS WILL AFFECT COASTAL PLAINS WITH CONVERGENCE JUST AHEAD OF FRONT. TORNADO WATCH WAS CANCELLED AT 10 PM. MINOR ADJUSTMENTS TO TEMPS AND SKY COVER. /PREVIOUS DISCUSSION/ AS OF 920 PM SATURDAY...A TORNADO WATCH REMAINS IN EFFECT FOR THE WESTERN PORTIONS OF EASTERN NC (MAINLY WEST OF HIGHWAY 17) UNTIL 1 AM. HAVE BEEN WATCHING A PERSISTENT SUPERCELL THUNDERSTORM WITH A DEEP AND PERSISTENT MESCALINE MOVING THROUGH CENTRAL NC SINCE 730 PM. THIS STORM WILL REMAIN NW OF OUR AREA. TO THE SOUTH OF THIS SYSTEM ADDITIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WERE DEVELOPING. THE HRRR MODEL BRINGS THIS CONVECTION INTO OUR PORTION OF THE COASTAL PLAIN AROUND 11 PM SO WILL CONTINUE TO MONITOR. SO FAR STORMS HAVE NOT WEAKENED WITH LOSS OF HEATING A SIGNAL THAT THEY ARE BEING DYNAMICALLY FORCED. WILL CONTINUE TO KEEP POPS IN THE CHANCE RANGE AS THE COVERAGE IN THE HIGH RESOLUTION MODELS REMAINS SCATTERED. LATE TONIGHT DRY SLOTTING SHOULD END ANY CHANCE OF PRECIPITATION UNTIL LATER SUNDAY WHEN THE UPPER LEVEL LOW MOVES THROUGH. USED A BLEND OF THE ECMWF/MET MOS FOR LOWS WITH READINGS IN THE UPPER 40S/LOWER 50S EXPECTED. && .SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/... AS OF 315 PM SATURDAY...WILL HAVE A BIT OF A LULL IN PRECIPITATION DURING THE MORNING HOURS ON SUNDAY...BUT AS UPPER LOW CROSSES TO OUR NORTH NEAR THE NORTH CAROLINA/VIRGINIA BORDER...THE STEEP LAPSE RATES AND MODEST MOISTURE WILL LEAD TO A HIGH CHANCE OF SHOWERS SUNDAY AFTERNOON. WITH GOOD COLD AIR ADVECTION...TEMPERATURES WILL ONLY RECOVER ABOUT 5 TO 7 DEGREES AND WILL FOLLOW THE COOLER NAM MOS GUIDANCE SUNDAY SHOWING HIGH TEMPERATURES IN THE LOW/MID 50S WITH GUSTY W/WNW WINDS. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... AS OF 3 PM SAT...THE LONG TERM PORTION OF THE FORECAST CAN BE SUMMARIZED AS DRYING OUT AND WARMING UP. MADE ONLY MINOR TWEAKS TO THE POPS ENDING THE RAIN SUNDAY NIGHT. SURFACE/UPPER LOW AND ASSOCIATED MOISTURE MOVE OFF TO THE NORTHEAST WITH RIDGING SURFACE AND ALOFT BUILDING IN FROM THE WEST. RIDGING BEGINS TO BREAK DOWN LATE IN THE WEEK AS AN UPPER LOW AND SURFACE COLD FRONT APPROACH FROM THE WEST. THE COLD FRONT WILL MOVE THROUGH FRIDAY NIGHT AND CARRIED A LOW CHANCE POP FOR SHOWERS AND STORMS. DRYING OUT SATURDAY WITH THE FRONT OFF THE COAST AND A SURFACE HIGH BUILDING TO THE NORTHWEST. NORTHWEST FLOW ON MONDAY WILL DIMINISH AND SLOWLY TRANSITION TO A WEST TO SOUTHWEST FLOW BY TUESDAY NIGHT AND CONTINUE INTO FRIDAY. HIGHS THIS WEEK WILL CLIMB WELL INTO THE 70S ACROSS MOST INLAND AREAS BEGINNING TUESDAY AS WINDS BECOME SOUTHERLY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... SHORT TERM /THROUGH 06Z MONDAY/... AS OF 130 AM SUNDAY...CONDITIONS HAVE IMPROVED TO VFR ALL BUT KPGV WHERE MVFR SCU STILL LINGERING. SCU VFR CIGS EXPECTED TO REDEVLOP ALL SITES 09Z-12Z AS UPR LOW MOVES INTO AREA FROM W. LOWER MVFR CIGS WILL DEVELOP WITH HEATING BY 15Z WITH SCT SHRA PSBL THROUGH AFTN AS COLD CORE UPR LOW MOVES ACROSS NRN SECTIONS. CLEARING EXPECTED DURING EVENING WITH LOSS OF HEATING. W WINDS WILL GUST UP TO 20-25 KT TODAY...DIMINISING AND BECOME NW THIS EVENING. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 3 PM SAT...IFR/MVFR CONDITIONS SUNDAY NIGHT WILL BECOME VFR ON MONDAY AS MOISTURE EXITS TO THE NORTHEAST AND A SURFACE/UPPER RIDGE BUILDS IN FROM THE WEST. NORTHWEST WINDS SUNDAY NIGHT AND MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT AND CONTINUE THROUGH THURSDAY. MODEL SOUNDINGS INDICATE LATE NIGHT/EARLY MORNING STRATUS/FOG POSSIBLE EACH MORNING WITH VERY LIGHT WINDS AND BOUNDARY LAYER MOISTURE. && .MARINE... SHORT TERM /TONIGHT AND SUNDAY/... AS OF 1230 AM SUNDAY...NO CHANGES WITH UPDATE. /PREVIOUS DISCUSSION/ AS OF 920 PM SATURDAY...NO CHANGES TO PREVIOUS FORECAST THINKING OTHER THAN TO EXTEND THE ADVISORIES FOR THE SOUNDS THROUGH EARLY MONDAY. GUSTY SE/S WINDS WILL CONTINUE TONIGHT AND HAVE ADDED THE ALBEMARLE SOUND TO THE SMALL CRAFT ADVISORY THAT WILL REMAIN IN EFFECT UNTIL 5 AM SUNDAY. WILL INITIALIZE WINDS AT 20 TO 25 KNOTS FOR ALL WATERS...EXCEPT 25 TO 30 KNOTS OVER THE OREGON INLET TO OCRACOKE LEG WHERE WINDS CONTINUE TO BE STRONGEST. THESE WINDS SHOULD SETTLE DOWN AFTER MIDNIGHT AS WINDS VEER TO MORE SW LATE. PER LATEST NWPS WAVE MODEL...SEAS OF 9 TO 13 FEET WILL PREVAIL OVER THE NORTHERN AND CENTRAL WATERS WITH GENERALLY 7 TO 10 FEET OVER SOUTHERN PORTIONS...WITH A SLIGHT DROP IN THE MORE WESTERLY FLOW EXPECTED DURING THE DAY ON SUNDAY. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 3 PM SAT...AN OVERALL IMPROVING TREND SEEN IN MARINE CONDITIONS THROUGH THE LONG TERM. SURFACE/UPPER LOW WILL MOVE OFF TO THE NORTHEAST SUNDAY NIGHT WITH SURFACE/UPPER RIDGE QUICKLY BUILDING IN AND LINGERING FOR MOST OF THE WEEK. SMALL CRAFT CONDITIONS WILL END FROM SOUTH TO NORTH MONDAY AND MONDAY NIGHT. NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT THROUGH THURSDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ130-135. SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ156-158. SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR AMZ150. && $$ SYNOPSIS...CTC NEAR TERM...CTC/JME/JBM SHORT TERM...CTC LONG TERM...HSA AVIATION...JBM/HSA MARINE...CTC/JME/HSA/JBM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1240 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COLD FRONT WILL MOVE OFFSHORE LATE TONIGHT. A SURFACE TROUGH WILL LINGER JUST WEST OF THE AREA INTO MONDAY. WEAK HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND TUESDAY. THE HIGH WILL MOVE SOUTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY. ANOTHER COLD WILL APPROACH THE AREA BY LATE WEEK. && .NEAR TERM /THROUGH SUNDAY/... AS OF 1230 AM SUNDAY...UPDATED TO REDUCE POPS TO 30% FOR COASTAL PLAINS OVERNIGHT AND 20% REST OF AREA. DRY SLOT WILL KEEP MOST OF AREA DRY REST OF NIGHT BUT SCT SHOWERS WILL AFFECT COASTAL PLAINS WITH CONVERGENCE JUST AHEAD OF FRONT. TORNADO WATCH WAS CANCELLED AT 10 PM. MINOR ADJUSTMENTS TO TEMPS AND SKY COVER. /PREVIOUS DISCUSSION/ AS OF 920 PM SATURDAY...A TORNADO WATCH REMAINS IN EFFECT FOR THE WESTERN PORTIONS OF EASTERN NC (MAINLY WEST OF HIGHWAY 17) UNTIL 1 AM. HAVE BEEN WATCHING A PERSISTENT SUPERCELL THUNDERSTORM WITH A DEEP AND PERSISTENT MESCALINE MOVING THROUGH CENTRAL NC SINCE 730 PM. THIS STORM WILL REMAIN NW OF OUR AREA. TO THE SOUTH OF THIS SYSTEM ADDITIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WERE DEVELOPING. THE HRRR MODEL BRINGS THIS CONVECTION INTO OUR PORTION OF THE COASTAL PLAIN AROUND 11 PM SO WILL CONTINUE TO MONITOR. SO FAR STORMS HAVE NOT WEAKENED WITH LOSS OF HEATING A SIGNAL THAT THEY ARE BEING DYNAMICALLY FORCED. WILL CONTINUE TO KEEP POPS IN THE CHANCE RANGE AS THE COVERAGE IN THE HIGH RESOLUTION MODELS REMAINS SCATTERED. LATE TONIGHT DRY SLOTTING SHOULD END ANY CHANCE OF PRECIPITATION UNTIL LATER SUNDAY WHEN THE UPPER LEVEL LOW MOVES THROUGH. USED A BLEND OF THE ECMWF/MET MOS FOR LOWS WITH READINGS IN THE UPPER 40S/LOWER 50S EXPECTED. && .SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/... AS OF 315 PM SATURDAY...WILL HAVE A BIT OF A LULL IN PRECIPITATION DURING THE MORNING HOURS ON SUNDAY...BUT AS UPPER LOW CROSSES TO OUR NORTH NEAR THE NORTH CAROLINA/VIRGINIA BORDER...THE STEEP LAPSE RATES AND MODEST MOISTURE WILL LEAD TO A HIGH CHANCE OF SHOWERS SUNDAY AFTERNOON. WITH GOOD COLD AIR ADVECTION...TEMPERATURES WILL ONLY RECOVER ABOUT 5 TO 7 DEGREES AND WILL FOLLOW THE COOLER NAM MOS GUIDANCE SUNDAY SHOWING HIGH TEMPERATURES IN THE LOW/MID 50S WITH GUSTY W/WNW WINDS. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... AS OF 3 PM SAT...THE LONG TERM PORTION OF THE FORECAST CAN BE SUMMARIZED AS DRYING OUT AND WARMING UP. MADE ONLY MINOR TWEAKS TO THE POPS ENDING THE RAIN SUNDAY NIGHT. SURFACE/UPPER LOW AND ASSOCIATED MOISTURE MOVE OFF TO THE NORTHEAST WITH RIDGING SURFACE AND ALOFT BUILDING IN FROM THE WEST. RIDGING BEGINS TO BREAK DOWN LATE IN THE WEEK AS AN UPPER LOW AND SURFACE COLD FRONT APPROACH FROM THE WEST. THE COLD FRONT WILL MOVE THROUGH FRIDAY NIGHT AND CARRIED A LOW CHANCE POP FOR SHOWERS AND STORMS. DRYING OUT SATURDAY WITH THE FRONT OFF THE COAST AND A SURFACE HIGH BUILDING TO THE NORTHWEST. NORTHWEST FLOW ON MONDAY WILL DIMINISH AND SLOWLY TRANSITION TO A WEST TO SOUTHWEST FLOW BY TUESDAY NIGHT AND CONTINUE INTO FRIDAY. HIGHS THIS WEEK WILL CLIMB WELL INTO THE 70S ACROSS MOST INLAND AREAS BEGINNING TUESDAY AS WINDS BECOME SOUTHERLY. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... SHORT TERM /TONIGHT AND SUNDAY/... AS OF 640 PM SATURDAY...SOME IFR CEILINGS ARE STILL BEING REPORTED AT THE TAF SITES BUT THINK THE TREND IS FOR IMPROVEMENT AS THE THREAT FOR WIDESPREAD PRECIPITATION IS OVER AND SOME DRYING IS EXPECTED TO MOVE INTO THE AREA LATER THIS EVENING. BASED ON UPSTREAM OBSERVATIONS AND TRENDS IN THE 12Z/18Z NAM FORECAST SOUNDINGS WILL FORECAST CONDITIONS IMPROVING TO MVFR AND CONTINUING FOR MUCH OF TONIGHT THEN A BRIEF PERIOD OF VFR CONDITIONS AROUND 09Z DURING THE PEAK OF DRYING. AN UPPER LOW IS FORECAST TO MOVE ACROSS NC SUNDAY. ASSOCIATED MOISTURE WILL LEAD TO A RETURN TO MVFR CEILINGS 12-14Z WHICH WILL THEN PERSIST FOR MUCH OF THE DAY. THERE COULD ALSO INTERMITTENT LIGHT RAIN OR DRIZZLE AT TIMES. GUSTY SOUTHERLY WINDS TONIGHT WILL BECOME WESTERLY ON SUNDAY. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 3 PM SAT...IFR/MVFR CONDITIONS SUNDAY NIGHT WILL BECOME VFR ON MONDAY AS MOISTURE EXITS TO THE NORTHEAST AND A SURFACE/UPPER RIDGE BUILDS IN FROM THE WEST. NORTHWEST WINDS SUNDAY NIGHT AND MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT AND CONTINUE THROUGH THURSDAY. MODEL SOUNDINGS INDICATE LATE NIGHT/EARLY MORNING STRATUS/FOG POSSIBLE EACH MORNING WITH VERY LIGHT WINDS AND BOUNDARY LAYER MOISTURE. && .MARINE... SHORT TERM /TONIGHT AND SUNDAY/... AS OF 1230 AM SUNDAY...NO CHANGES WITH UPDATE. /PREVIOUS DISCUSSION/ AS OF 920 PM SATURDAY...NO CHANGES TO PREVIOUS FORECAST THINKING OTHER THAN TO EXTEND THE ADVISORIES FOR THE SOUNDS THROUGH EARLY MONDAY. GUSTY SE/S WINDS WILL CONTINUE TONIGHT AND HAVE ADDED THE ALBEMARLE SOUND TO THE SMALL CRAFT ADVISORY THAT WILL REMAIN IN EFFECT UNTIL 5 AM SUNDAY. WILL INITIALIZE WINDS AT 20 TO 25 KNOTS FOR ALL WATERS...EXCEPT 25 TO 30 KNOTS OVER THE OREGON INLET TO OCRACOKE LEG WHERE WINDS CONTINUE TO BE STRONGEST. THESE WINDS SHOULD SETTLE DOWN AFTER MIDNIGHT AS WINDS VEER TO MORE SW LATE. PER LATEST NWPS WAVE MODEL...SEAS OF 9 TO 13 FEET WILL PREVAIL OVER THE NORTHERN AND CENTRAL WATERS WITH GENERALLY 7 TO 10 FEET OVER SOUTHERN PORTIONS...WITH A SLIGHT DROP IN THE MORE WESTERLY FLOW EXPECTED DURING THE DAY ON SUNDAY. LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 3 PM SAT...AN OVERALL IMPROVING TREND SEEN IN MARINE CONDITIONS THROUGH THE LONG TERM. SURFACE/UPPER LOW WILL MOVE OFF TO THE NORTHEAST SUNDAY NIGHT WITH SURFACE/UPPER RIDGE QUICKLY BUILDING IN AND LINGERING FOR MOST OF THE WEEK. SMALL CRAFT CONDITIONS WILL END FROM SOUTH TO NORTH MONDAY AND MONDAY NIGHT. NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT THROUGH THURSDAY. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ130-135. SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ156-158. SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR AMZ150. && $$ SYNOPSIS...CTC NEAR TERM...CTC/JME/JBM SHORT TERM...CTC LONG TERM...HSA AVIATION...JME/HSA/LEP MARINE...CTC/JME/HSA/JBM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1145 PM CDT SAT MAR 29 2014 .UPDATE... ISSUED AT 1145 PM CDT SAT MAR 29 2014 BUMPED UP CLOUD COVER A BIT...BUT NO OTHER BIG CHANGES TO THE GOING FORECAST. WILL CONTINUE TO KEEP POPS IN THE 20-40 PERCENT RANGE FOR SCATTERED SHOWERS MOVING ACROSS THE AREA. TEMPS CONTINUE TO BE FAIRLY WARM WITH SOUTHERLY WINDS KEEPING READINGS UP. UPDATE ISSUED AT 936 PM CDT SAT MAR 29 2014 MADE SOME ADDITIONAL TWEAKS TO POPS/WX. MOST OF THE RETURNS IN THE NORTHERN CWA HAVE NOT YET BEEN REACHING THE GROUND...BUT ROLLA JUST OUTSIDE THE CWA HAS STARTED REPORTING RAIN. CONTINUED TO KEEP SOME 20-40 POPS IN THE NORTHERN COUNTIES AND ADJUSTED THEM A BIT SOUTH TO COUNT FOR RADAR TRENDS TO OUR WEST AS WELL AS THE HRRR AND RAP RUNS. CONTINUE TO THINK THAT SOUTH WINDS WILL KEEP TEMPS UP AND TYPE AS RAIN FOR NOW. UPDATE ISSUED AT 634 PM CDT SAT MAR 29 2014 MADE A FEW MINOR TWEAKS TO POPS ALONG THE NORTHERN BORDER...BUT NO MAJOR CHANGES FOR THIS EVENING. THE CHANCE FOR A FEW RAIN SHOWERS IN THE NORTH WILL CONTINUE AND SOUTH WINDS WILL CONTINUE TO KEEP TEMPS UP. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 342 PM CDT SAT MAR 29 2014 FAIRLY QUIET THIS PERIOD AND MODELS IN DECENT AGREEMENT. VERY WARM AIRMASS WILL PROPAGATE ACROSS THE REGION TONIGHT...WITH MIN TEMPS AROUND THE FREEZING MARK. AN UPPER WAVE SHOULD BRING SCATTERED SHOWERS NEAR THE INTERNATIONAL BORDER TONIGHT. ON SUNDAY...COLDER AIRMASS BEGINS TO MOVE INTO THE WESTERN FA AS THE WINTER STORM TO THE WEST ORGANIZES AND APPROACHES THE REGION. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 342 PM CDT SAT MAR 29 2014 SUNDAY NIGHT-TUESDAY...THE LARGE WINTER STORM IS STILL ON TRACK TO HIT THE REGION (MOSTLY ON MONDAY). THE 12Z MODELS HAVE TRENDED SLIGHTLY SLOWER (AND NORTHWARD WITH THE HEAVIEST SNOWFALL). THE ECMWF REMAINS THE SLOWEST/FURTHEST NORTH...WHILE THE GFS IS FURTHEST SOUTH WITH THE HEAVIEST SNOWFALL (BUT STILL WITHIN THE FA). THE GEM/UKMET ARE SOMEWHERE IN THE MIDDLE...AND AT THIS POINT MAKE THE MOST SENSE. THE NAM (ALTHOUGH SIMILAR WITH QPF) IS THE FAST OUTLIER AND HAS BEEN DISCOUNTED. THE ECMWF IS ON THE NORTHERN EDGE OF THE ENSEMBLE ENVELOPE...AND WOULD EXPECT THIS SOLUTION TO TREND SLIGHTLY SOUTH WITH THE HEAVIEST QPF OVER THE NEXT FEW MODEL RUNS. AT ANY RATE...THE INGREDIENTS ARE IN PLACE FOR HEAVY SNOW SOMEWHERE...DEPENDING ON THE EXACT TRACK OF THIS SYSTEM. AMOUNTS WITHIN THIS HEAVY SNOW AREA COULD AMOUNT TO A FOOT OR MORE...WITH WIDESPREAD SNOWFALL OF 6 TO 12 INCHES APPEARING LIKELY (THE NORTHERN AND SOUTHERN EDGE OF THIS SNOWFALL AREA WILL BE CHALLENGING). THE SLOWER TREND OF THE MODELS HAS INCREASED THE EXPECTED NORTHERLY WINDS ON MONDAY. NO MATTER WHICH MODEL SOLUTION (EXCEPT THE FASTER NAM) YOU LOOK AT...ANTICIPATE SPEEDS AROUND 30 KNOTS GIVEN HIGH WIND INGREDIENTS AND MOS GUIDANCE. CONFIDENCE HAS INCREASED IN BLIZZARD CONDITIONS SOMEWHERE WITHIN THE FA...AND WILL `UPGRADE` THE WINTER STORM WATCH TO A BLIZZARD WATCH FOR THE `MOST LIKELY` BLIZZARD AREA. DEFINITELY NOT ENOUGH CONFIDENCE FOR A WARNING AT THIS POINT FOR ANY AREA AS THE EXACT TRACK AND SPEED OF THE SYSTEM WILL ULTIMATELY AFFECT P-TYPE...SNOW AMOUNTS...AND WIND SPEEDS. TUE NIGHT THROUGH SAT...SFC HIGH PRESSURE MOVES OVER THE FA ON TUE NIGHT KEEPING THINGS COOL AND DRY. BY WED THE FLOW TURNS MORE TO THE SOUTHWEST WITH MODELS DIVERGING ON SOLUTIONS. THE 12Z GFS IS QUICKER AND BRINGS IN LIGHT SNOW ON WED WHILE THE ECMWF/GEM KEEP WED DRY. THESE DIFFERENCES CONTINUE INTO WED NIGHT WITH THE GFS MOVING THE LIGHT SNOW INTO THE NE FA AND THE ECMWF/GEM STILL NOT SHOWING MUCH OF ANYTHING. MORE POTENT SYSTEM LOOKING TO BE THU/THU NIGHT ALTHOUGH STILL NOT MUCH AGREEMENT BETWEEN THE MODELS. THE ECMWF SHOWS THE FURTHEST NORTH SOLUTION WHICH WOULD GIVE ANOTHER BATCH OF SNOW TO THE SOUTHERN FA. THE GFS IS THE FURTHEST SOUTH WITH THE WAVE WHILE THE GEM IS IN BETWEEN. WILL LEAVE LOW SNOW CHANCES ACROSS MAINLY THE SOUTHERN FA FOR NOW AND SEE IF MODELS COME INTO BETTER AGREEMENT LATER. TEMPS GENERALLY LOOK TO STAY ON THE COOLER SIDE THROUGHOUT BUT COULD BE GREATLY AFFECTED BY SNOW COVER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1145 PM CDT SAT MAR 29 2014 SOUTH WINDS HAVE CONTINUED TO BE A BIT MORE GUSTY THAN EXPECTED BUT THINK THAT WINDS WILL DECREASE TOWARDS MORNING AS THE CENTER OF THE SFC LOW MOVES INTO THE REGION. CONDITIONS WILL CONTINUE TO BE VFR WITH CLOUDS AROUND 10000 FT. WINDS WILL SHIFT TO THE NORTHWEST BY MID TO LATE MORNING. HAVE CIGS COMING DOWN...BUT KEPT THE MVFR CONDITIONS OUT UNTIL LATE AFTERNOON OR EVENING. NORTH WINDS WILL PICK UP MORE TO AROUND 20 KTS WITH HIGHER GUSTS LATE IN THE PERIOD AS THE SFC LOW WRAPS UP. WILL ONLY GO WITH SOME -SN MENTION AT KDVL FOR NOW AS THINK THAT MOST OF THE SIGNIFICANT SNOW WILL NOT SET UP UNTIL LATE SUNDAY NIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR NDZ027>030-038-039-049-052-053. WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR NDZ008-016-024-026-054. MN...BLIZZARD WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR MNZ001>003-029-030-040. WINTER STORM WATCH FROM LATE SUNDAY NIGHT THROUGH LATE MONDAY NIGHT FOR MNZ004>009-013>017-022>024-027-028-031-032. && $$ UPDATE...JR SHORT TERM...TG LONG TERM...GODON/TG AVIATION...JR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 AM CDT SUN MAR 30 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 319 AM CDT SUN MAR 30 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH SOUTH OF THE GULF OF ALASKA...A VIGOROUS SHORTWAVE TROUGH COMING INTO CENTRAL CALIFORNIA...AND A RIDGE AXIS FROM TEXAS INTO THE FORECAST AREA. PROFILER AND VAD WIND DATA SHOWED A CORRIDOR OF SOUTHWESTERLY 40-55 KT WINDS AT 925MB JUST TO THE WEST OF THE RIDGE AXIS. THESE WINDS ARE PROPELLING WARMER AIR THAT WAS OBSERVED OVER THE PLAINS YESTERDAY TOWARDS THE FORECAST AREA. ITS WORTH NOTING HIGHS YESTERDAY WERE IN THE 60S TO LOW 70S FROM WESTERN NORTH DAKOTA INTO OKLAHOMA...ASSOCIATED WITH 925MB TEMPS OF 10 TO 20C. CLOUD COVER MOSTLY OF THE SCATTERED CIRRUS VARIETY...REFLECTIVE OF UPPER LEVEL MOISTURE STREAMING FROM THE PACIFIC ON WATER VAPOR. AIRMASS ACROSS MUCH OF THE PLAINS AND THE FORECAST AREA VERY DRY PER 00Z SOUNDINGS...NOTED TOO FROM PRECIPITABLE WATER VALUES BETWEEN 0.2- 0.3 INCHES. AT THE SURFACE...THE SURFACE RIDGE THAT WAS OVER THE AREA YESTERDAY HAS SHIFTED EAST TO OVER LAKE MICHIGAN...WHILE PRESSURES ARE FALLING ALONG THE LEE OF THE ROCKIES. THE SURFACE RIDGE HAS PUSHED ANY MEANINGFUL SURFACE MOISTURE...DEWPOINTS AT OR ABOVE 40F...DOWN TO THE GULF OF MEXICO COAST. SYNOPTICALLY...THE UPPER RIDGING PRESENT OVER THE FORECAST AREA LOOKS TO PERSIST THROUGH TONIGHT...WITH A SHIFT TO THE EAST AFTER MIDNIGHT. THE PUSH EAST TO THE RIDGE IS CAUSED BY THE VIGOROUS SHORTWAVE LIFTING INTO THE FAR NORTHEAST COLORADO AREA BY 12Z MONDAY. ITS ALSO WORTH NOTING THAT THE SHORTWAVE BECOMES NEGATIVELY TILTED. WITH THE FORECAST AREA PROGGED TO BE IN THE WARM SECTOR OF A DEEPENING LOW COMING OUT OF COLORADO AND INTO CENTRAL NEBRASKA BY 12Z MONDAY...MUCH OF THE FORECAST CONCERN IS ON TEMPERATURES. 925MB TEMPS ARE PROGGED TO CONTINUE TO CLIMB THROUGH THE DAY ON A BREEZY SOUTH TO SOUTHWEST WIND...RISING FROM 1 TO 5C AT 12Z TO 9 TO 13C BY 00Z. THESE READINGS HOLD NEARLY STEADY FOR TONIGHT DUE TO PERSISTENT 25-35 KT SOUTH WINDS. COMBINATION OF THE AFOREMENTIONED WARM ADVECTION AND SUNSHINE SHOULD EASILY PUSH HIGHS INTO THE 60S ALONG AND SOUTHWEST OF I-94. NORTH OF I-94...SNOW PACK AND COOLER 925MB TEMPS WILL HOLD HIGHS BACK INTO THE 50S. THE MIXING TODAY TOO WILL BE LIMITED A LITTLE DUE TO SCT-BKN CIRRUS EMANATING FROM NEBRASKA AREA CURRENTLY. WITH A LOW LEVEL JET IN PLACE TONIGHT...MOST LOCATIONS SHOULD ONLY SEE LOWS IN THE 40S. THERE ARE INDICATIONS THE TYPICAL COLD SPOTS MIGHT DECOUPLE OR AT LEAST SEE LIGHTER WINDS...ALLOWING TEMPERATURES THERE TO DIP INTO THE UPPER 30S. PRECIPITATION-WISE...PLENTIFUL DRY AIR IN PLACE AS SEEN AT 00Z LAST EVENING WILL KEEP CONDITIONS DRY THROUGH THIS EVENING. AFTER MIDNIGHT...THERE IS GOOD AGREEMENT AMONG MODELS FOR A WARM CONVEYOR BELT OF PRECIPITATION TO DEVELOP OVER EASTERN NEBRASKA AND WESTERN IOWA. MUCH OF THIS PRECIPITATION CORRELATES WITH ISENTROPIC LIFT ON THE 305-310K SURFACES...OR AT PRESSURES ABOVE 700MB. IN ANY EVENT...AT LEAST THROUGH TONIGHT...THE FORECAST AREA STAYS DRY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 319 AM CDT SUN MAR 30 2014 MUCH OF THE FOCUS IS ON THE MONDAY THROUGH TUESDAY PERIOD. IMPACTS DESCRIBED BELOW... SYNOPTICALLY...ATTENTION IS COMPLETELY ON THE VIGOROUS SHORTWAVE TROUGH APPROACHING THE CENTRAL CALIFORNIA COAST. MODELS CONTINUE TO CONVERGE ON A COMMON SOLUTION FOR HANDLING THIS NEGATIVE TILT TROUGH...THOUGH THERE IS SOME SLIGHT TIMING SPREAD. MODEL CONSENSUS SHOWS THE TROUGH LIFTING INTO SOUTHWEST MN BY 00Z TUESDAY... NORTHWEST WI BY 12Z TUESDAY AND INTO ONTARIO BY 00Z WEDNESDAY. THE NAM REMAINS THE FASTEST OF THE CONSENSUS AND SEEMS A LITTLE SUSPICIOUS...SEEING THAT THE ECMWF HAS BEEN TRENDING SLOWER OVER THE PAST FEW DAYS. GIVEN THE VIGOROUS NATURE OF THE SHORTWAVE...WOULD SEEM A SLOWER AND DEEPER ROUTE WOULD BE THE WAY TO GO. REGARDING THE SURFACE LOW...FOLLOWING THE SAME PREMISES...BELIEVE THE SLOWER...DEEPER MORE WRAPPED SYSTEM PRESENTED BY THE CANADIAN/UKMET/ECMWF IS MORE LIKELY COMPARED TO THE NAM AND EVEN GFS. WPC HAS ALSO FAVORED THE SAME MODELS. PRECIPITATION-WISE...THE WARM CONVEYOR BELT DEVELOPING OFF TO OUR WEST LOOKS LIKELY TO MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA MONDAY MORNING. HARD TO SAY IF IT IS GOING TO PROGRESS INTO WISCONSIN PRIOR TO 18Z SEEING THE DRIER NAM/ECMWF LOOK. THEREFORE HAVE ONLY KEPT 20-40 PERCENT CHANCES 15-18Z. FOR THE AFTERNOON... THERE ARE SIGNS THAT THE WARM CONVEYOR PRECIPITATION MAY FALL APART AS IT MOVES INTO WISCONSIN...OR AT LEAST SHIFT NORTH INTO NORTHERN WISCONSIN....ESPECIALLY IN THE CANADIAN MODELS. GFS 305-310K ISENTROPIC LIFT PROGS SUGGEST THE SAME. THEREFORE...HAVE KEPT PRECIPITATION CHANCES MOSTLY IN THE 20-50 PERCENT RANGE OUTSIDE OF TAYLOR COUNTY WHERE PRECIPITATION IS MOST LIKELY. FOCUS THEN SHIFTS WEST ON WHETHER SHOWERS OR STORMS CAN FIRE ALONG A COLD FRONT / DRY LINE. THE GFS/CANADIAN/ECMWF/UKMET ALL INITIATE A SCT- BKN LINE OF SHOWERS NEAR I-35 TOWARDS 00Z. HOWEVER...THERE ARE TWO HUGE CONCERNS FOR THIS BEING A LINE OF SURFACE BASED CONVECTION... FIRST IS A FAIRLY STOUT CAP AROUND 700MB...SECOND ARE SURFACE DEWPOINTS WHICH MODELS TRY TO JUMP INTO THE LOW 50S. THE DEWPOINTS SEEM WAY OVERDONE. NOW CANT RULE OUT THE LINE OF SHOWERS FORMING MORE ABOVE THE CAP GIVEN FORCING FROM THE LEFT EXIT REGION ALONG WITH DPVA WITH THE TROUGH. SINCE THERE IS NO CAPE ABOVE THE CAP AND CONCERNED PRECIPITATION MAY NOT FORM AT ALL...REMOVED THE THUNDER CHANCE. THIS SHOULD ALSO REDUCE THE CONCERN OF ANY POSSIBLE SEVERE WEATHER. IF A LINE DOES FORM...IT LOOKS TO LIFT NORTHEAST THROUGH THE AREA DURING THE EVENING. PRECIPITATION LOOKS MORE LIKELY AFTER MIDNIGHT INTO TUESDAY MORNING OVER THE NORTHWEST HALF OF THE AREA AS THE COLD CONVEYOR BELT WRAPS IN. MOST OF THIS SHOULD BE A LIGHT SNOW WITH LITTLE ACCUMULATION. THIS SNOW WILL TAPER OFF TUESDAY AFTERNOON WITH THE DEPARTURE OF THE SYSTEM. TEMPERATURES...BEING IN THE WARM SECTOR ALL OF MONDAY WITH 9-13C 925MB READINGS...COMBINED WITH A WARMER START...THAT BREAK IN PRECIPITATION DURING THE AFTERNOON TO ALLOW FOR MIXING AND BREEZY SOUTH WINDS...HIGHS AGAIN SHOULD CLIMB INTO THE 60S AT MOST LOCATIONS. SNOWPACK HOLDS TAYLOR DOWN INTO THE 50S. READINGS THEN TANK MONDAY NIGHT AS THE COLD AIR WRAPS IN SOUTHWEST TO NORTHEAST. MUCH COOLER HIGHS FOR TUESDAY...THOUGH SOUTHERN AREAS SHOULD CLIMB INTO THE MID 40S AS THE COLD AIR DEPARTS. WINDS...SOUTHERLY 925MB WINDS INCREASE THROUGH MONDAY AS THE NEGATIVE TILT SHORTWAVE TROUGH APPROACHES. BY 21Z...MOST MODELS PROG THEM AROUND 40 KT WHILE 850MB WINDS APPROACH 50-55 KT...STRONGEST SOUTH OF I-90. DAYTIME MIXING SHOULD BE ENOUGH TO GIVE GUSTS OF 30- 35 KT...WITH A PRESSURE FALL CROSSING EAU CLAIRE GIVING SOME ISALLOBARIC HELP. AN ADVISORY MAY BE NEEDED IF NAM/GFS MOMENTUM TRANSFER PROGS ARE CORRECT...SUGGESTING 35-42 KT GUSTS. WITH THE COLD SIDE OF THE SYSTEM...925MB WINDS ARE A LITTLE LESS...CLOSER TO 35 KT FOR MONDAY NIGHT INTO TUE MORNING. THESE SHOULD EASILY MIX TO THE GROUND. MORE UNCERTAINTY EXISTS ON THE NEED FOR THE ADVISORY ON THE COLD SIDE. FOR TUESDAY NIGHT AND BEYOND... NEXT ITEM OF INTEREST IS THE TROUGH CURRENTLY SOUTH OF THE GULF OF ALASKA WHICH IS PROGGED TO END UP IN THE SOUTHWESTERN U.S. ON WEDNESDAY. UPPER RIDGING BUILDS DOWNSTREAM AHEAD OF THE TROUGH...BUT MOSTLY SOUTH OF THE FORECAST AREA. THIS KEEPS A COLDER LOW LEVEL AIRMASS IN PLACE. MEANWHILE...ISENTROPIC LIFT OF GULF OF MEXICO MOISTURE DOWNSTREAM OF THE UPPER TROUGH MAY SPREAD SOME PRECIPITATION INTO SOUTHERN PORTIONS OF THE FORECAST AREA PER 30.00Z GFS/GFS ENSEMBLES WEDNESDAY AND WEDNESDAY NIGHT. HOWEVER...30.00Z CANADIAN AND ECMWF KEEP THE PRECIPITATION SOUTH OF THE FORECAST AREA. HAVE SPLIT THE DIFFERENCE WHICH RESULTS IN MAINLY A DRY FORECAST NORTH OF I-90 TO SOME 20-50 PERCENT CHANCES SOUTH. THURSDAY COULD END UP BEING A MOSTLY DRY DAY. CONFIDENCE IS BEGINNING TO INCREASE FOR PRECIPITATION THURSDAY NIGHT THROUGH FRIDAY. THIS IS WHEN MODELS ARE IN GOOD AGREEMENT LIFTING THE TROUGH INTO THE FORECAST AREA. WINTER WEATHER ADVISORIES REMAIN POSSIBLE...MOSTLY DUE TO ACCUMULATING SNOW. DRIER WEATHER LOOKS TO MOVE IN FOR SATURDAY AS THE SYSTEM DEPARTS. BELOW NORMAL TEMPERATURES ARE LIKELY FOR MUCH OF TUESDAY NIGHT AND BEYOND GIVEN THE UPPER FLOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1132 PM CDT SAT MAR 29 2014 THE MAIN FOCUS AT THE TAF SITES IS WITH THE WINDS. THE LOW LEVEL PRESSURE GRADIENT WILL TIGHTEN UP OVERNIGHT INTO TOMORROW MORNING AS A LOW PRESSURE SYSTEM TRACKS INTO SOUTHERN CANADA. SOME STRONG LOW LEVEL WINDS LOOK LIKE THEY WILL GET INTO RST OVERNIGHT WITH SOME 50KT WINDS AROUND 1.5KFT. OTHERWISE...WINDS WILL BECOME GUSTY SUNDAY MORNING INTO THE EARLY AFTERNOON WITH GUSTS INTO THE 20 TO 30KT RANGE. AS THE GRADIENT RELAXES IN THE AFTERNOON...THE WINDS WILL START TO SUBSIDE. CLOUD COVER LOOKS FAIRLY MINIMAL AND MAINLY ABOVE 15KFT. && .HYDROLOGY... ISSUED AT 319 AM CDT SUN MAR 30 2014 BASED ON GAUGE READINGS ALONG THE KICKAPOO FOR THOSE THAT STILL HAVE FLOOD WARNINGS...CONFIDENCE IS DECREASING THAT THEY WILL MAKE IT TO FLOOD. READSTOWN HAS STARTED FALLING...WHEN IT SHOULD STILL BE RISING. IF TRENDS CONTINUE...THE WARNINGS MAY BE CANCELLED. FOCUS THEN SHIFTS TO THE BLACK...BUFFALO AND TREMPEALEAU RIVERS. THE WARM UP OCCURRING TODAY AND PERSISTING INTO MONDAY EVENING... FEATURING HIGHS IN THE 55-65 RANGE AND LOWS IN THE 38-48 RANGE ALONG WITH BREEZY SOUTH WINDS...WILL HELP RAPIDLY MELT THE SNOW PACK THAT IS IN PLACE ALONG AND NORTH OF HIGHWAY 10. THIS RUNOFF WILL MAKE FLOODING A POSSIBILITY DURING THE WEEK. ON A POSITIVE NOTE...THE PRECIPITATION FROM THE SYSTEM MOVING THROUGH THE AREA MONDAY AND MONDAY NIGHT CONTINUES TO LOOK LESS AND LESS. AT THIS POINT...RAIN DOES NOT APPEAR TO BE MUCH OF A FACTOR TO THE RIVERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...HALBACH HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1127 AM EDT SUN MAR 30 2014 .SYNOPSIS... ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH MONDAY...BRINGING PLENTY OF SUNSHINE AND INCREASINGLY WARMER TEMPERATURES. A FRONT CROSSING THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY WILL BRING A CHANCE FOR SOME LIGHT SHOWERS...ALONG WITH A RETURN TO COOLER WEATHER. RAIN MAY MIX WITH...OR EVEN CHANGE OVER...TO A BIT OF SNOW ON TUESDAY...BUT NO ACCUMULATIONS ARE EXPECTED. COOL WEATHER WILL CONTINUE FOR THE MIDDLE AND END PORTIONS OF THE WEEK...WITH ANOTHER CHANCE FOR A WINTRY MIX OF PRECIPITATION THURSDAY AND FRIDAY. && .UPDATE... ISSUED AT 1125 AM EDT SUN MAR 30 2014 HIGH PRESSURE SURFACE AND ALOFT WILL ENSURE A NICE AFTERNOON FOR NORTHERN MICHIGAN WITH JUST A FEW CLOUDS DRIFTING BY. WIDESPREAD HIGHS IN THE 40S EXPECTED. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH IMPACT WEATHER POTENTIAL: NONE. PATTERN SUMMARY: AN EARLY MORNING LOOK AT THE PATTERN ACROSS THE CONUS REVEALS AN ACTIVE SETUP...WITH LOW PRESSURE SYSTEMS ALONG BOTH COASTS...AND A NARROW RIDGE OF HIGH PRESSURE IN BETWEEN THESE SYSTEMS... ARCHING FROM QUEBEC...THROUGH THE GREAT LAKES AND DOWN THE MISSISSIPPI VALLEY. THIS RIDGE AXIS CURRENTLY LIES JUST WEST OF THE FORECAST AREA...WITH A RIBBON OF CLEARING ALLOWING LOW TEMPERATURES TO FALL RAPIDLY AS BOUNDARY LAYER WINDS DECOUPLE. LOOKING FORWARD THROUGH THE SHORT TERM FORECASTS REQUIRES US TO LOOK UPSTREAM...AND...SOMEWHAT DIFFERENTLY THAN WE HAVE SEEN OF LATE...MUCH OF WHAT IS UPSTREAM IS DOMINATED BY PACIFIC...MARITIME POLAR AIR...WITH ANY ARCTIC AIR NOW BOTTLED UP NORTH OF THE REGION. THIS PACIFIC FLOW WILL RESULT IN LEE-SIDE CYCLOGENESIS EAST OF THE ROCKIES DURING THE DAY TODAY...WITH THIS LOW PRESSURE DEEPENING AND BEGINNING TO DEPART TO THE NORTH AND EAST BY THE END OF THIS PERIOD AROUND DAYBREAK MONDAY. THE DOWNSTREAM LONGWAVE TROUGH IS MUCH SLOWER MOVING...AND THE DEVELOPING SQUEEZE PLAY IN BETWEEN THESE FEATURES WILL FORCE HEIGHTS TO BUILD OVER THE GREAT LAKES WITH QUIET AND MODERATING CONDITIONS EXPECTED FOR NORTHERN MICHIGAN. CERTAINLY A WELCOME REPRIEVE FROM AN EXCEPTIONALLY COLD MONTH OF MARCH. THROUGH DAYBREAK: TEMPERATURES WILL CONTINUE TO TUMBLE THROUGH THE TEENS GIVEN CLEAR SKIES AND CALM-LIGHT WINDS. ALSO CAN/T RULE OUT SOME PATCHY GROUND FOG GIVEN IMPRESSIVE OVERNIGHT COOLDOWN. TODAY: RIDGE AXIS WILL BE PRETTY MUCH OVERHEAD TO START THE DAY...GRADUALLY SHIFTING EAST TO A POSITION OVER LAKE HURON TOWARDS EVENING. THERE/S A RELATIVE LACK OF MOISTURE THROUGH THE COLUMN TO START THE DAY WITH PWATS SUB 0.25" /A LITTLE BELOW SEASONAL NORMS FOR LATE MARCH/ WITH VALUES INCREASING DURING THE DAY AS A CHUNK OF PACIFIC MOISTURE /SEEN NOW AS A PLUME OF DEEP MOISTURE ACROSS THE NORTHWESTERN QUARTER OF THE COUNTRY/ RIDES EAST. WHILE THIS COULD MANIFEST ITSELF AS SOME HIGH CLOUDS FOR THE NORTHERN HALF OF THE CWA /ESP FOR THE SECOND HALF OF THE DAY/...THE LACK OF LLEVEL MOISTENING BENEATH BUILDING MID LEVEL HEIGHTS SUGGESTS NO REAL POTENTIAL FOR CU DEVELOPMENT. THUS...EXPECT ABUNDANT SUNSHINE FOR THE AREA WITH NO SENSIBLE WEATHER CONCERNS. TEMPERATURES /CONFIDENCE: HIGH/: TRAJECTORY ANALYSIS PLACES THIS AFTERNOON/S AIRMASS OVER SOUTHERN MINNESOTA 24 HOURS PREVIOUS WITH T9S SURGING TO 0-3C BY LATE AFTERNOON UNDER STRONG WARM ADVECTION. WITH BUILDING HEIGHTS AND NEARBY RIDGE AXIS...MIXING ISN/T GOING TO BE TOO STRONG. LOOKING BACK TO MINNESOTA...AREAS THAT WERE UNABLE TO MIX DEEPLY REACHED THE LOWER 40S...WITH UPPER 40S FURTHER WEST WHERE MECHANICAL MIXING COMBINED WITH WARMER TEMPS ALOFT TO BOOST SURFACE TEMPS. EXPECT THAT WE/LL BE CLOSER TO THE FORMER TODAY...AND EXPECT HIGHS IN THE 40-45 DEGREE RANGE. AMAZINGLY...THAT WILL PUT US JUST ABOUT WHERE WE SHOULD BE FOR THE END OF MARCH. AS MENTIONED BY THE PREVIOUS DAYSHIFT...LIGHT FLOW REGIME AND SOMEWHAT WARMER TEMPERATURES SHOULD ALLOW FOR SOME LAKE BREEZE DEVELOPMENT...KEEPING HIGHS LOCALLY COOLER ALONG THE LAKE HURON COAST. TONIGHT: RIDGE CONTINUES TO PUSH EAST OF THE GREAT LAKES REGION...WITH NORTHERN STREAM COLD FRONT STALLING NEAR LAKE SUPERIOR AS LOW PRESSURE ALONG THE EAST SLOPES OF THE ROCKIES BEGINS TO DEPART AND HEAD NORTHEAST. MOISTURE CONTINUES TO SLOWLY INCREASE...BUT PRIMARILY AT UPPER LEVELS WITH TOP-DOWN SATURATION LIKELY ONLY YIELDING AN INCREASE IN UPPER LEVEL CLOUDS THROUGH THE OVERNIGHT. GRADIENT STRENGTHENS THROUGH THE NIGHT...WITH MOST LOCATIONS RE-COUPLING DURING THE OVERNIGHT. SEE NO REPEAT OF ANY FOG GIVEN BETTER LLEVEL MIXING AND CONTINUED DRY LLEVEL CONDITIONS. TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: TEMPERATURES WILL BE A LITTLE COMPLEX WITH EVENING MCLEAR SKIES AND DECOUPLING LIKELY TO GIVE WAY TO INCREASED MIXING AS THE NIGHT GOES ON. THIS WILL YIELD LOWS COLDEST OVER NORTHEAST LOWER WITH LOWS LIKELY TO DIP TO AROUND 20 /AND PERHAPS A TAD BELOW THIS/...WITH TEMPS OVER NORTHWEST LOWER STRUGGLING TO FALL MUCH BELOW THE FREEZING MARK. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 309 AM EDT SUN MAR 30 2014 ...REAL SPRING "WARMTH" GIVES WAY TO BELOW NORMAL TEMPERATURES (GO FIGURE)... HIGH IMPACT WEATHER POTENTIAL: WATCHING WINTRY PRECIP THREAT LATER IN THE WEEK. OVERVIEW: PATTERN REMAINS AN AGITATED ONE...WITH EXTENDED AMPED PACIFIC REGIME OVER THE CONUS TUCKED NICELY ON SOUTH SIDE OF WELL DEVELOPED NORTH CANADA COLD CORE GYRE. PACIFIC PATTERN CONTINUES TO WIN OUT OVER NORTHERN MICHIGAN...WITH STEADY RETREAT OF OVERHEAD COLD AIRMASS AS AGGRESSIVE UPSTREAM WARMING BEGINS. 00Z RAOB/HIGH RES RAP GUIDANCE CONFIRMS SUCH...SHOWING H8 TEMPERATURES SPIKING INTO THE TEENS (THAT`S ABOVE ZERO FOLKS!) ACROSS THE HIGH PLAINS...WITH ABOVE ZERO H8 AIR ALREADY ADVANCING TO THE MISSISSIPPI RIVER. EXPECTED RATHER SUBSTANTIAL UPPER MISSISSIPPI VALLEY LOW PRESSURE DEVELOPMENT EARLY THIS WORK WEEK WILL ONLY HELP THE NORTHERN LAKES WARMING CAUSE...WITH MUCH OF THE AREA TO FALL SQUARELY IN THE WARM SECTOR OF THIS SYSTEM AS IT TRACKS TO OUR NORTHWEST. UNFORTUNATELY...COOL AIR WILL BE FORCED SOUTH ON ITS BACKSIDE...ONCE AGAIN DROPPING TEMPERATURES TO BELOW NORMAL LEVELS AS WE HEAD THROUGH THE MID AND AND PORTIONS OF NEXT WEEK. PACIFIC WAVE TRAIN REMAINS...AT LEAST SETTING UP SOME POTENTIAL FOR BOUTS OF MORE WINTRY WEATHER HEADING INTO THURSDAY AND FRIDAY. OH...THE JOY! PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY! TEMPERATURE TRENDS THROUGHOUT...PRECIP TIMING/AND EVENTUAL TYPE...HEADING THROUGH NEXT WORK WEEK. DETAILS: JUST HOW WARM TO GO ON MONDAY? ABOUT TEXTBOOK END OF MARCH/BEGINNING OF APRIL SPRING STORM WILL BE UNDERGOING FULL DEVELOPMENT ACROSS THE CENTRAL PLAINS EARLY MONDAY...EXPECTED TO PASS SOMEWHERE VICINITY CENTRAL/WESTERN UPPER MICHIGAN TUESDAY. STRONG DOWNSTREAM OFF THE DECK WAA EXPECTED...WITH NOW MULTI-DAY PROGS SUPPORTING H8 READINGS SPIKING TO NEAR 10C BY LATER MONDAY OVER NORTHERN MICHIGAN. WITH ELEVATED WARM FRONT ALREADY NORTH OF THE AREA...AND CORE OF MID LEVEL DYNAMICS WELL OFF TO OUR WEST...WOULD EXPECT PLENTY OF SUNSHINE TO FURTHER KICK THE WARMING INTO OVERDRIVE. INCREASINGLY DEEP MIXED LAYER/FORCED MECHANICAL MIXING PER INCREASING WINDS SHOULD ALLOW SURFACE TEMPERATURES TO RESPOND ACCORDINGLY...AND REALLY LIKE INHERITED HIGHS WILL INTO THE 50S/NEAR 60 OVER NORTHERN LOWER MICHIGAN. SOUTHEAST LOW LEVEL FLOW WILL KEEP NORTHEAST LOWER AND EASTERN UPPER MICHIGAN SEVERAL DEGREES COOLER. MILD AIR CONTINUES INTO MONDAY NIGHT AS SOUTH FLOW REMAINS...AND FEEL SOME AREAS MAY FAIL TO FALL OUT OF THE 40S. DRY WEATHER GIVES WAY TO INCREASING SHOWER CHANCES MONDAY NIGHT AS OCCLUDED FRONT INTERACTS WITH NARROW BAND OF ENHANCED DEEP LAYER MOISTURE. STRONGEST AND DEEPEST DYNAMICS REMAIN TO OUR NORTHWEST...WHERE HEAVIEST AND STEADIEST PRECIPITATION SHALL RESIDE. BACK TO 2014 SPRING NORMALCY QUICKLY ON TUESDAY AS SURGE OF COLDER AIR FOLLOWS PASSAGE OF OCCLUDED FRONT. MORNING HIGH TEMPERATURES IN THE 30S AND 40S WILL SLOWLY FALL THROUGH THE AFTERNOON ON GUSTY SOUTHWEST TO WEST WINDS. LIGHT RAIN/SNOW SHOWERS TRANSITION TO MAINLY SNOW AS COLD AIR DEEPENS AND SYSTEM BACKSIDE MOISTURE REMAINS. JUST MINIMAL...IF ANY...ACCUMULATION IS EXPECTED. UNCERTAINTY THE NAME OF THE GAME HEADING INTO THE MID AND END PORTIONS OF THE WEEK. QUESTIONS ARE MANY CONCERNING NEXT WAVE EXPECTED TO EJECT OUT OF THE INTERMOUNTAIN WEST. INTERACTION BETWEEN SOUTHERN CANADA HIGH/ASSOCIATED DRY AIR FEED AND WHAT SHOULD BE RATHER VIGOROUS MID LEVEL WAVE LEADING TO RATHER SIGNIFICANT DISCREPANCIES AMONGST MID RANGE GUIDANCE. ECMWF REMAINS MOST ROCK-STEADY...SUGGESTING A MORE AMPED AND FURTHER NORTH SOLUTION WITH LOW PRESSURE MOVING DIRECTLY ACROSS THE GREAT LAKES TO END THE WORK WEEK. OTHER GUIDANCE STARTING TO FALL IN LINE WITH THIS MORE NORTH/AMPED SOLUTION...ALTHOUGH HONESTLY...THIS DOES LITTLE TO INCREASE CONFIDENCE AS A MORE SOUTH DISPLACED SYSTEM IS FULLY PLAUSIBLE GIVEN EXPECTED SET-UP AND POTENTIAL FOR A STRONGER CANADIAN HIGH. TEMPERATURE PROFILE REMAINS MARGINALLY SUPPORTIVE OF A MIXED PRECIP EVENT IF FURTHER NORTH SOLUTIONS VERIFY. SET-UP ALSO HAS SOME INTRIGUING FREEZING RAIN POSSIBILITIES...WITH POTENTIAL FOR MAINTENANCE OF DRY AND COLD EAST FLOW TO MAINTAIN SUB-FREEZING SURFACE TEMPERATURES...ALL THE WHILE ELEVATED WARM NOSE DEEPENS. OF COURSE...MUCH TOO FAR OUT TO SHOW SUCH SPECIFICS...ESPECIALLY CONSIDERING UNCERTAINTY IF SYSTEM WILL EVEN DIRECTLY AFFECT OUR AREA. LITTLE CHOICE BUT TO RUN WITH A GENERIC RAIN/SNOW CHANCE WORDING FOR NOW...WITH PLENTY OF TIME TO FINE-TUNE DETAILS IN COMING DAYS. WHILE EXCEPTIONALLY COLD AIR NOW LOOKS LIKE A THING OF THE PAST...OVERALL TRENDS FAVOR BELOW NORMAL TEMPERATURES WEDNESDAY THROUGH NEXT WEEKEND...WITH HIGHS MOSTLY IN THE 30S AND LOWER 40S/OVERNIGHT LOWS IN THE 20S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 635 AM EDT SUN MAR 30 2014 UNRESTRICTED CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE DURATION. ONLY SCT/BKN HIGH LEVEL CLOUDS. LIGHT SOUTH/SOUTHEAST SURFACE WINDS EXPECTED TODAY ACROSS WESTERN TAF SITES...WITH A LAKE INDUCED MORE EASTERLY COMPONENT AT KAPN. LIGHT/CALM WINDS OVERNIGHT. LOW LEVEL JET INTENSIFIES TONIGHT...PRODUCING LLWS AT ALL SITES EXCLUDING KAPN. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JPB SYNOPSIS...MSB SHORT TERM...ARNOTT LONG TERM...MSB AVIATION...MSB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
639 AM EDT SUN MAR 30 2014 .SYNOPSIS... ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH MONDAY...BRINGING PLENTY OF SUNSHINE AND INCREASINGLY WARMER TEMPERATURES. A FRONT CROSSING THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY WILL BRING A CHANCE FOR SOME LIGHT SHOWERS...ALONG WITH A RETURN TO COOLER WEATHER. RAIN MAY MIX WITH...OR EVEN CHANGE OVER...TO A BIT OF SNOW ON TUESDAY...BUT NO ACCUMULATIONS ARE EXPECTED. COOL WEATHER WILL CONTINUE FOR THE MIDDLE AND END PORTIONS OF THE WEEK...WITH ANOTHER CHANCE FOR A WINTRY MIX OF PRECIPITATION THURSDAY AND FRIDAY. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH IMPACT WEATHER POTENTIAL: NONE. PATTERN SUMMARY: AN EARLY MORNING LOOK AT THE PATTERN ACROSS THE CONUS REVEALS AN ACTIVE SETUP...WITH LOW PRESSURE SYSTEMS ALONG BOTH COASTS...AND A NARROW RIDGE OF HIGH PRESSURE IN BETWEEN THESE SYSTEMS... ARCHING FROM QUEBEC...THROUGH THE GREAT LAKES AND DOWN THE MISSISSIPPI VALLEY. THIS RIDGE AXIS CURRENTLY LIES JUST WEST OF THE FORECAST AREA...WITH A RIBBON OF CLEARING ALLOWING LOW TEMPERATURES TO FALL RAPIDLY AS BOUNDARY LAYER WINDS DECOUPLE. LOOKING FORWARD THROUGH THE SHORT TERM FORECASTS REQUIRES US TO LOOK UPSTREAM...AND...SOMEWHAT DIFFERENTLY THAN WE HAVE SEEN OF LATE...MUCH OF WHAT IS UPSTREAM IS DOMINATED BY PACIFIC...MARITIME POLAR AIR...WITH ANY ARCTIC AIR NOW BOTTLED UP NORTH OF THE REGION. THIS PACIFIC FLOW WILL RESULT IN LEE-SIDE CYCLOGENESIS EAST OF THE ROCKIES DURING THE DAY TODAY...WITH THIS LOW PRESSURE DEEPENING AND BEGINNING TO DEPART TO THE NORTH AND EAST BY THE END OF THIS PERIOD AROUND DAYBREAK MONDAY. THE DOWNSTREAM LONGWAVE TROUGH IS MUCH SLOWER MOVING...AND THE DEVELOPING SQUEEZE PLAY IN BETWEEN THESE FEATURES WILL FORCE HEIGHTS TO BUILD OVER THE GREAT LAKES WITH QUIET AND MODERATING CONDITIONS EXPECTED FOR NORTHERN MICHIGAN. CERTAINLY A WELCOME REPRIEVE FROM AN EXCEPTIONALLY COLD MONTH OF MARCH. THROUGH DAYBREAK: TEMPERATURES WILL CONTINUE TO TUMBLE THROUGH THE TEENS GIVEN CLEAR SKIES AND CALM-LIGHT WINDS. ALSO CAN/T RULE OUT SOME PATCHY GROUND FOG GIVEN IMPRESSIVE OVERNIGHT COOLDOWN. TODAY: RIDGE AXIS WILL BE PRETTY MUCH OVERHEAD TO START THE DAY...GRADUALLY SHIFTING EAST TO A POSITION OVER LAKE HURON TOWARDS EVENING. THERE/S A RELATIVE LACK OF MOISTURE THROUGH THE COLUMN TO START THE DAY WITH PWATS SUB 0.25" /A LITTLE BELOW SEASONAL NORMS FOR LATE MARCH/ WITH VALUES INCREASING DURING THE DAY AS A CHUNK OF PACIFIC MOISTURE /SEEN NOW AS A PLUME OF DEEP MOISTURE ACROSS THE NORTHWESTERN QUARTER OF THE COUNTRY/ RIDES EAST. WHILE THIS COULD MANIFEST ITSELF AS SOME HIGH CLOUDS FOR THE NORTHERN HALF OF THE CWA /ESP FOR THE SECOND HALF OF THE DAY/...THE LACK OF LLEVEL MOISTENING BENEATH BUILDING MID LEVEL HEIGHTS SUGGESTS NO REAL POTENTIAL FOR CU DEVELOPMENT. THUS...EXPECT ABUNDANT SUNSHINE FOR THE AREA WITH NO SENSIBLE WEATHER CONCERNS. TEMPERATURES /CONFIDENCE: HIGH/: TRAJECTORY ANALYSIS PLACES THIS AFTERNOON/S AIRMASS OVER SOUTHERN MINNESOTA 24 HOURS PREVIOUS WITH T9S SURGING TO 0-3C BY LATE AFTERNOON UNDER STRONG WARM ADVECTION. WITH BUILDING HEIGHTS AND NEARBY RIDGE AXIS...MIXING ISN/T GOING TO BE TOO STRONG. LOOKING BACK TO MINNESOTA...AREAS THAT WERE UNABLE TO MIX DEEPLY REACHED THE LOWER 40S...WITH UPPER 40S FURTHER WEST WHERE MECHANICAL MIXING COMBINED WITH WARMER TEMPS ALOFT TO BOOST SURFACE TEMPS. EXPECT THAT WE/LL BE CLOSER TO THE FORMER TODAY...AND EXPECT HIGHS IN THE 40-45 DEGREE RANGE. AMAZINGLY...THAT WILL PUT US JUST ABOUT WHERE WE SHOULD BE FOR THE END OF MARCH. AS MENTIONED BY THE PREVIOUS DAYSHIFT...LIGHT FLOW REGIME AND SOMEWHAT WARMER TEMPERATURES SHOULD ALLOW FOR SOME LAKE BREEZE DEVELOPMENT...KEEPING HIGHS LOCALLY COOLER ALONG THE LAKE HURON COAST. TONIGHT: RIDGE CONTINUES TO PUSH EAST OF THE GREAT LAKES REGION...WITH NORTHERN STREAM COLD FRONT STALLING NEAR LAKE SUPERIOR AS LOW PRESSURE ALONG THE EAST SLOPES OF THE ROCKIES BEGINS TO DEPART AND HEAD NORTHEAST. MOISTURE CONTINUES TO SLOWLY INCREASE...BUT PRIMARILY AT UPPER LEVELS WITH TOP-DOWN SATURATION LIKELY ONLY YIELDING AN INCREASE IN UPPER LEVEL CLOUDS THROUGH THE OVERNIGHT. GRADIENT STRENGTHENS THROUGH THE NIGHT...WITH MOST LOCATIONS RE-COUPLING DURING THE OVERNIGHT. SEE NO REPEAT OF ANY FOG GIVEN BETTER LLEVEL MIXING AND CONTINUED DRY LLEVEL CONDITIONS. TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: TEMPERATURES WILL BE A LITTLE COMPLEX WITH EVENING MCLEAR SKIES AND DECOUPLING LIKELY TO GIVE WAY TO INCREASED MIXING AS THE NIGHT GOES ON. THIS WILL YIELD LOWS COLDEST OVER NORTHEAST LOWER WITH LOWS LIKELY TO DIP TO AROUND 20 /AND PERHAPS A TAD BELOW THIS/...WITH TEMPS OVER NORTHWEST LOWER STRUGGLING TO FALL MUCH BELOW THE FREEZING MARK. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 309 AM EDT SUN MAR 30 2014 ...REAL SPRING "WARMTH" GIVES WAY TO BELOW NORMAL TEMPERATURES (GO FIGURE)... HIGH IMPACT WEATHER POTENTIAL: WATCHING WINTRY PRECIP THREAT LATER IN THE WEEK. OVERVIEW: PATTERN REMAINS AN AGITATED ONE...WITH EXTENDED AMPED PACIFIC REGIME OVER THE CONUS TUCKED NICELY ON SOUTH SIDE OF WELL DEVELOPED NORTH CANADA COLD CORE GYRE. PACIFIC PATTERN CONTINUES TO WIN OUT OVER NORTHERN MICHIGAN...WITH STEADY RETREAT OF OVERHEAD COLD AIRMASS AS AGGRESSIVE UPSTREAM WARMING BEGINS. 00Z RAOB/HIGH RES RAP GUIDANCE CONFIRMS SUCH...SHOWING H8 TEMPERATURES SPIKING INTO THE TEENS (THAT`S ABOVE ZERO FOLKS!) ACROSS THE HIGH PLAINS...WITH ABOVE ZERO H8 AIR ALREADY ADVANCING TO THE MISSISSIPPI RIVER. EXPECTED RATHER SUBSTANTIAL UPPER MISSISSIPPI VALLEY LOW PRESSURE DEVELOPMENT EARLY THIS WORK WEEK WILL ONLY HELP THE NORTHERN LAKES WARMING CAUSE...WITH MUCH OF THE AREA TO FALL SQUARELY IN THE WARM SECTOR OF THIS SYSTEM AS IT TRACKS TO OUR NORTHWEST. UNFORTUNATELY...COOL AIR WILL BE FORCED SOUTH ON ITS BACKSIDE...ONCE AGAIN DROPPING TEMPERATURES TO BELOW NORMAL LEVELS AS WE HEAD THROUGH THE MID AND AND PORTIONS OF NEXT WEEK. PACIFIC WAVE TRAIN REMAINS...AT LEAST SETTING UP SOME POTENTIAL FOR BOUTS OF MORE WINTRY WEATHER HEADING INTO THURSDAY AND FRIDAY. OH...THE JOY! PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY! TEMPERATURE TRENDS THROUGHOUT...PRECIP TIMING/AND EVENTUAL TYPE...HEADING THROUGH NEXT WORK WEEK. DETAILS: JUST HOW WARM TO GO ON MONDAY? ABOUT TEXTBOOK END OF MARCH/BEGINNING OF APRIL SPRING STORM WILL BE UNDERGOING FULL DEVELOPMENT ACROSS THE CENTRAL PLAINS EARLY MONDAY...EXPECTED TO PASS SOMEWHERE VICINITY CENTRAL/WESTERN UPPER MICHIGAN TUESDAY. STRONG DOWNSTREAM OFF THE DECK WAA EXPECTED...WITH NOW MULTI-DAY PROGS SUPPORTING H8 READINGS SPIKING TO NEAR 10C BY LATER MONDAY OVER NORTHERN MICHIGAN. WITH ELEVATED WARM FRONT ALREADY NORTH OF THE AREA...AND CORE OF MID LEVEL DYNAMICS WELL OFF TO OUR WEST...WOULD EXPECT PLENTY OF SUNSHINE TO FURTHER KICK THE WARMING INTO OVERDRIVE. INCREASINGLY DEEP MIXED LAYER/FORCED MECHANICAL MIXING PER INCREASING WINDS SHOULD ALLOW SURFACE TEMPERATURES TO RESPOND ACCORDINGLY...AND REALLY LIKE INHERITED HIGHS WILL INTO THE 50S/NEAR 60 OVER NORTHERN LOWER MICHIGAN. SOUTHEAST LOW LEVEL FLOW WILL KEEP NORTHEAST LOWER AND EASTERN UPPER MICHIGAN SEVERAL DEGREES COOLER. MILD AIR CONTINUES INTO MONDAY NIGHT AS SOUTH FLOW REMAINS...AND FEEL SOME AREAS MAY FAIL TO FALL OUT OF THE 40S. DRY WEATHER GIVES WAY TO INCREASING SHOWER CHANCES MONDAY NIGHT AS OCCLUDED FRONT INTERACTS WITH NARROW BAND OF ENHANCED DEEP LAYER MOISTURE. STRONGEST AND DEEPEST DYNAMICS REMAIN TO OUR NORTHWEST...WHERE HEAVIEST AND STEADIEST PRECIPITATION SHALL RESIDE. BACK TO 2014 SPRING NORMALCY QUICKLY ON TUESDAY AS SURGE OF COLDER AIR FOLLOWS PASSAGE OF OCCLUDED FRONT. MORNING HIGH TEMPERATURES IN THE 30S AND 40S WILL SLOWLY FALL THROUGH THE AFTERNOON ON GUSTY SOUTHWEST TO WEST WINDS. LIGHT RAIN/SNOW SHOWERS TRANSITION TO MAINLY SNOW AS COLD AIR DEEPENS AND SYSTEM BACKSIDE MOISTURE REMAINS. JUST MINIMAL...IF ANY...ACCUMULATION IS EXPECTED. UNCERTAINTY THE NAME OF THE GAME HEADING INTO THE MID AND END PORTIONS OF THE WEEK. QUESTIONS ARE MANY CONCERNING NEXT WAVE EXPECTED TO EJECT OUT OF THE INTERMOUNTAIN WEST. INTERACTION BETWEEN SOUTHERN CANADA HIGH/ASSOCIATED DRY AIR FEED AND WHAT SHOULD BE RATHER VIGOROUS MID LEVEL WAVE LEADING TO RATHER SIGNIFICANT DISCREPANCIES AMONGST MID RANGE GUIDANCE. ECMWF REMAINS MOST ROCK-STEADY...SUGGESTING A MORE AMPED AND FURTHER NORTH SOLUTION WITH LOW PRESSURE MOVING DIRECTLY ACROSS THE GREAT LAKES TO END THE WORK WEEK. OTHER GUIDANCE STARTING TO FALL IN LINE WITH THIS MORE NORTH/AMPED SOLUTION...ALTHOUGH HONESTLY...THIS DOES LITTLE TO INCREASE CONFIDENCE AS A MORE SOUTH DISPLACED SYSTEM IS FULLY PLAUSIBLE GIVEN EXPECTED SET-UP AND POTENTIAL FOR A STRONGER CANADIAN HIGH. TEMPERATURE PROFILE REMAINS MARGINALLY SUPPORTIVE OF A MIXED PRECIP EVENT IF FURTHER NORTH SOLUTIONS VERIFY. SET-UP ALSO HAS SOME INTRIGUING FREEZING RAIN POSSIBILITIES...WITH POTENTIAL FOR MAINTENANCE OF DRY AND COLD EAST FLOW TO MAINTAIN SUB-FREEZING SURFACE TEMPERATURES...ALL THE WHILE ELEVATED WARM NOSE DEEPENS. OF COURSE...MUCH TOO FAR OUT TO SHOW SUCH SPECIFICS...ESPECIALLY CONSIDERING UNCERTAINTY IF SYSTEM WILL EVEN DIRECTLY AFFECT OUR AREA. LITTLE CHOICE BUT TO RUN WITH A GENERIC RAIN/SNOW CHANCE WORDING FOR NOW...WITH PLENTY OF TIME TO FINE-TUNE DETAILS IN COMING DAYS. WHILE EXCEPTIONALLY COLD AIR NOW LOOKS LIKE A THING OF THE PAST...OVERALL TRENDS FAVOR BELOW NORMAL TEMPERATURES WEDNESDAY THROUGH NEXT WEEKEND...WITH HIGHS MOSTLY IN THE 30S AND LOWER 40S/OVERNIGHT LOWS IN THE 20S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 635 AM EDT SUN MAR 30 2014 UNRESTRICTED CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE DURATION. ONLY SCT/BKN HIGH LEVEL CLOUDS. LIGHT SOUTH/SOUTHEAST SURFACE WINDS EXPECTED TODAY ACROSS WESTERN TAF SITES...WITH A LAKE INDUCED MORE EASTERLY COMPONENT AT KAPN. LIGHT/CALM WINDS OVERNIGHT. LOW LEVEL JET INTENSIFIES TONIGHT...PRODUCING LLWS AT ALL SITES EXCLUDING KAPN. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ SYNOPSIS...MSB SHORT TERM...ARNOTT LONG TERM...MSB AVIATION...MSB
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
622 AM CDT SUN MAR 30 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT SUN MAR 30 2014 ANOTHER WARM DRY SURGE OF AIR MOVES OFF THE CNTL ROCKIES TODAY. THE TEMPERATURE FORECAST FOLLOWS THE UPPER MIDDLE OF THE 13 MODEL SUPER ENSEMBLE FOR HIGHS IN THE 70S TO NEAR 80. A STATIONARY FRONT IS EXPECTED TO DEVELOP ALONG THE SD BORDER CAUSING WINDS TO BACK ACROSS THE NORTH KEEPING HIGHS NEAR 70. WE ALSO SEE A FAIRLY SOLID CIRRUS SHIELD DEVELOPING OFF THE LARAMIE AND FRONT RANGE LIMITING HEATING SOMEWHAT. SOUTH WINDS INCREASE TO 10 TO 20 MPH WITH GUSTS TO 25 MPH ACROSS MOST OF THE FCST AREA. FOR TONIGHT...SFC LOW PRESSURE WILL TRACK THROUGH THE CENTER OF THE FCST AREA AND WINDS BECOME NORTHWEST BEHIND THE SFC LOW ACROSS WRN NEB. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING AND OVERNIGHT IN RESPONSE TO A LOW LEVEL JET AND COOLING/FALLING HEIGHTS ALOFT. THE NEW MODEL CONSENSUS BRINGS A SHARP 500 MB TROF INTO ERN WY AT 06Z WHICH CLOSES OFF ACROSS NW NEB BY 12Z. THERE ARE SIGNS OF THE HEIGHTS BACKING IN ALOFT ACROSS WRN SD AT THIS TIME WHICH IS TROUBLING SINCE THE LATEST ENSEMBLE SOLN IS TAKING THE UPPER LEVEL ENERGY ACROSS THE TETONS AND BIG HORN RANGES BUT THEN IT DROPPING SOUTH OF THE BLACK HILLS. THIS MORE SRN TRACK RAISES THE POP ACROSS NWRN NEB BETWEEN 06Z AND 12Z. THE NAM AND GEM REGIONAL THEN BRING THE RAIN SNOW LINE INTO NRN SHERIDAN COUNTY BETWEEN 09Z AND 12Z. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 359 AM CDT SUN MAR 30 2014 ATTENTION IN THE EXTENDED PERIODS CENTER ON PRECIPITATION CHANCES...MAINLY THE POTENTIAL OF TWO SIGNIFICANT LATE WINTER TYPE STORMS THAT MAY BRING ACCUMULATING SNOW TO PORTIONS OF THE CWA. THE FIRST SYSTEM WILL BE ONGOING ACROSS OUR NORTHERN ZONES BY 12Z MONDAY. LOW PRESSURE AND ASSOCIATED PV ANOMALY WILL CROSS FROM THE CENTRAL ROCKIES NORTHEAST OUT ONTO PLAINS...DRAGGING MODIFIED ARCTIC AIR SOUTH FROM CANADA ACROSS THE NORTHERN/CENTRAL PLAINS. MEDIUM RANGE MODELS HAVE GENERALLY COME INTO FAIR AGREEMENT WITH THE TRACK OF THE SURFACE CYCLONE...BUT INTENSITY/TIMING DIFFERENCES STILL EXIST. ATTM GENERALLY FAVOR THE GEM SOLUTION IN WHICH THE TRACK FAVORS STRONG FRONTOGENETIC FORCING MAINLY NORTH OF THE CWA. THAT BEING SAID...THERE/S STILL STRONG AGREEMENT THAT SNOW WILL WRAP AROUND THE LOW BACK ACROSS NORTHERN PORTIONS OF THE CWA. ATTM SNOW ACCUMULATIONS LOOK FAVORABLE FOR NORTHWESTERN NEBRASKA EARLY MONDAY...THEN TRANSITION EAST THROUGH THE DAY. THE PTYPE FORECAST IS STILL PROBLEMATIC. THE GEM SOLUTION IS WARMER WITHIN THE WARM SECTOR AS THE MODEL LIFTS THE LOW FURTHER NORTH THAN EAST...CHANGEOVER TO ALL SNOW MAY NOT OCCUR FOR OUR FAR EASTERN ZONES UNTIL MID-LATE AFTERNOON. WHERE THE CHANGE OVER DOES OCCUR EARLY...IMPACTS TO TRAVEL WOULD BE EXPECTED...ESPECIALLY GIVEN WIND GUSTS IN EXCESS 45 MPH. ATTM ALONG AND NORTH OF HIGHWAY 20 IN CHERRY AND SHERIDAN COUNTIES IS WHERE THE GREATEST CONFIDENCE IN SEEING THE EARLY CHANGEOVER AND ACCUMULATING SNOW. FOR THIS...WILL ISSUE A WINTER WEATHER ADVISORY WITH THIS FORECAST PACKAGE FOR THE TWO COUNTIES LISTED AS IMPACTS TO KVTN...RANCHING...HIGHWAY 20 AND THE POPULOUS CENTERED ALONG THE HIGHWAY ARE ANTICIPATED TO BE SIGNIFICANT. NOTE...IT COULD VERY WELL BE THAT SOUTHERN PORTIONS OF THESE TWO COUNTIES NOT SEE MUCH IF ANY ACCUMULATING SNOW WITH THIS SYSTEM WHILE THE FAR NORTH EXPERIENCES NEAR BLIZZARD CONDITIONS AND UP TO 4 INCHES OF SNOW. A HIGH END WIND ADVISORY IS ANTICIPATED MONDAY AS WELL ACROSS THE ENTIRE CWA. A STACKED PRESSURE GRADIENT WITH PRESSURE RISES ON THE ORDER OF UP TO 3 MB PER HOUR WILL LEAD TO NEAR HIGH WIND WARNING GUST CRITERIA. WILL LET THE DAY SHIFT FINE TUNE THE SPECIFICS. LASTLY...NEGATIVE LI/S ACROSS NORTH CENTRAL/NORTHERN NEBRASKA EARLY MONDAY WITH WEAK INSTABILITY ALOFT MAY YIELD A FEW EMBEDDED CONVECTIVE SHOWERS...WHETHER SNOW OR RAIN. NO MENTION OF THUNDER WAS INCLUDED BEYOND 12Z MONDAY...BUT MAY NEED TO BE LOOKED AT FURTHER. LOW AMPLITUDE TRANSITORY RIDGING BUILDS ATOP THE PLAINS ON TUESDAY WITH A RETURN TO AN ACTIVE PATTERN BY MIDWEEK. SOUTHWESTERLY FLOW IN THE UPPER LEVELS WILL PREVAIL AS THE NEXT LONGWAVE TROUGH OF INTEREST STARTS TO BUILD ACROSS THE DESERT SOUTHWEST WEDNESDAY. SLIGHT OPPORTUNITIES FOR QPF ALSO ARRIVE ON WEDNESDAY WITH THE APPROACH OF FAVORABLE UPPER LEVEL JET SUPPORT AND A SW DISTURBANCE. HOWEVER BETTER CHANCES ARRIVE LATE IN THE WEEK AS THE TROUGH EJECTS NORTHEAST FROM THE 4 CORNERS ONTO THE CENTRAL PLAINS. THERE REMAINS LARGE DISCREPANCIES ON HOW THE MODELS HANDLE THIS SYSTEM...WITH THE ECMWF NOW TAKING ON A NEGATIVE TILT AND A FAVORABLE TRACK OF THE H5 LOW FOR SNOW ACCUMULATION...POSSIBLY SIGNIFICANT ACROSS THE WEST CENTRAL SANDHILLS. THE GFS REMAINS OPEN AND PROGRESSIVE WITH FAR LESS IMPACTS. DUE TO THE MYRIAD OF WEATHER CURRENTLY GOING ON RIGHT NOW...FELT IT WAS BEST TO NOT VARY FROM A GENERAL MODEL BLEND WITH THIS LATE WEEK SYSTEM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 622 AM CDT SUN MAR 30 2014 VFR IS EXPECTED ALL AREAS TODAY THROUGH 06Z TONIGHT. ISOLATED THUNDERSTORMS MAY DEVELOP IN THE WEST THIS EVENING WHICH WOULD DEVELOP EASTWARD. THEREAFTER...AN APPROACHING UPPER LEVEL TROF/DISTURBANCE...CURRENTLY MOVING THROUGH SRN CAL...WILL MOVE INTO WRN NEB. MVFR IN RAIN CHANGING TO SNOW IS EXPECTED TO DEVELOP ACROSS NORTHWEST NEB WHICH WILL SPREAD EAST...NORTH OF NEBRASKA HIGHWAY 2. VFR IS EXPECTED SOUTH OF HIGHWAY 2. && .FIRE WEATHER... ISSUED AT 359 AM CDT SUN MAR 30 2014 RED FLAG CONDITIONS ARE EXPECTED ACROSS THE ERN PANHANDLE...CENTRAL SANDHILLS...FRENCHMAN BASIN AND THE LOESS PLAINS. THE FORECAST IS A LOW END RED FLAG WARNING AS THE RAP SHOWS WINDS AT 700MB WEAKENING THIS AFTERNOON WHILE THE NAM ACTUALLY STRENGTHENS THEM. THE FORECAST FOLLOWS A BLEND OF THE GUIDANCE FROM THE RAP13...HRRR...NAMDNG AND AVN MOS MODELS FOR SOUTH WINDS OF 10 TO 20 MPH AND GUSTS TO 25 MPH. DEWPOINTS SHOULD FALL INTO THE TEENS...BUT ABOUT 5 DEGREES F HIGHER THAN SATURDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 9 PM CDT /8 PM MDT/ THIS EVENING FOR NEZ204-206-210-219. WINTER WEATHER ADVISORY FROM 4 AM CDT /3 AM MDT/ TO 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004-005-094. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...CDC FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1044 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COMPLEX LOW PRESSURE SYSTEM WILL CONTINUE TO BRING MIXED PRECIPITATION TO THE NORTH COUNTRY THIS MORNING...AND TAPER OFF TO DRIZZLE AND FREEZING DRIZZLE THIS AFTERNOON. PORTIONS OF CENTRAL AND SOUTHERN VERMONT WILL CONTINUE TO SEE LIGHT ICE ACCUMULATIONS TONIGHT INTO MONDAY MORNING AS THE LOW TRACKS OFF THE EASTERN SEABOARD...WITH DRIER CONDITIONS RETURNING TO THE ENTIRE REGION BY MONDAY AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1035 AM EDT SUNDAY...LOW PRESSURE ON DELAWARE COAST WILL CONTINUE TO AFFECT NORTH COUNTRY WEATHER FOR THE REST OF TODAY AS IT MOVES VERY SLOWLY EASTWARD...BECOMING CAPTURED BY CLOSED UPPER LOW. MOST SIGNIFICANT AREA OF PRECIPITATION HAS LIFTED NORTH OF FORECAST AREA...BUT LATEST RADAR CONTINUES TO SHOW BANDS OF PRECIPITATION WHICH WILL LIKELY PERSIST THROUGH THE DAY. THIS PRECIPITATION MOSTLY ON THE LIGHT SIDE...AND GENERALLY IN FORM OF RAIN OR DRIZZLE IN VERMONT AND LIGHT SNOW OR MIXED PRECIPITATION IN NEW YORK. ADDITIONAL ACCUMULATIONS OF SNOW/ICE TODAY SHOULD NOT AMOUNT TO MUCH. NO CHANGES TO ADVISORIES/WARNINGS AT THIS TIME...BUT WILL REASSESS AROUND MIDDAY. SITUATION MORE COMPLICATED IN PARTS OF VERMONT WHERE SOME ADDITIONAL ICING ANTICIPATED TONIGHT. TEMPS TODAY NOT CHANGING MUCH FROM CURRENT READINGS. HAVE ADDED MENTION OF SOME FOG FOR MUCH OF THE AREA. EARLIER DISCUSSIONS BELOW... AS OF 716 AM EDT SUNDAY...QUICK UPDATE TO CANCEL ADVISORIES FOR PORTIONS OF NORTHERN VERMONT AS BULK OF PRECIP SHIFTS NORTH OF THE AREA AND PTYPE TRANSITIONS TO RAIN OR DRIZZLE. PREVIOUS DISCUSSION...FORECAST PLAYING OUT FAIRLY WELL WITH A MYRIAD OF PRECIPITATION TYPES EXPERIENCED ACROSS THE NORTH COUNTRY OVERNIGHT ASSOCIATED WITH LOW PRESSURE MOVING EASTWARD THROUGH THE MID-ATLANTIC STATES. ACROSS VERMONT...PRECIP STARTED OUT AS A MIX OF SNOW...RAIN AND FREEZING RAIN BUT AS OF 5 AM SEEING MAINLY A MIX OF RAIN AND SNOW. MEANWHILE...ACROSS NORTHERN NEW YORK SNOW HAS BEEN THE PREDOMINANT PTYPE WITH SEVERAL INCHES OF SNOW ACCUMULATIONS BEING REPORTED. MODEL OF CHOICE OVERNIGHT HAS BEEN THE RAP WHICH CONTINUES TO HANDLE THE VERTICAL THERMAL STRUCTURE VERY WELL SHOWING +0C LAYER AT 850MB SHIFTING NORTHWARD THROUGH VT WHILE FROM THE SURFACE-925MB REMAINED NEARLY ISOTHERMAL. AS THE BULK OF PRECIP SHIFTS NORTHWARD OUT OF THE REGION THIS MORNING...WE`RE LEFT WITH SUPER-SATURATED LOW LEVELS AND ZERO ICE IN THE FAVORED SNOW GROWTH REGION ALOFT ALONG WITH COOLING MID LEVELS. THIS WILL SUPPORT A TRANSITION TO DRIZZLE AND/OR FREEZING DRIZZLE ACROSS MOST OF THE AREA...THOUGH SOME LINGERING SNOW SHOWERS WILL BE POSSIBLE ACROSS THE SAINT LAWRENCE VALLEY DUE TO COLDER PROFILES. TEMPS WILL BASICALLY GO NOWHERE TODAY UNDER THICK CLOUD COVER AND NORTH TO NORTHEASTERLY FLOW...HOLDING STEADY IN THE LOW/MID 30S TO UPPER 20S AREA-WIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 510 AM EDT SUNDAY...FOR TONIGHT INTO MONDAY...MODELS HAVE COME INTO BETTER AGREEMENT IN REGARDS TO ANOTHER ROUND OF MIXED PRECIPITATION ACROSS CENTRAL AND SOUTHERN VERMONT AS ADDITIONAL SHORTWAVE ENERGY ROTATES AROUND THE SLOWLY DEPARTING UPPER LOW. LOW LEVEL TEMPERATURES COOL ACROSS THE AREA OVERNIGHT WHILE TEMPS AT MID-LEVELS REMAIN ABOVE FREEZING SETTING THE STAGE FOR AREAS OF FREEZING DRIZZLE/RAIN THROUGH MONDAY MORNING. GREATEST CHANCES OF ICE ACCUMULATION WILL BE OVER CENTRAL AND SOUTHEASTERN ZONES DUE TO THE PROXIMITY WITH UPPER LOW....AND WINTER WX ADVISORIES HAVE BEEN EXTENDED FOR A LIGHT GLAZE OF UP TO A TENTH OF AN INCH LIKELY. LATE MONDAY INTO MONDAY NIGHT DRIER CONDITIONS RETURN TO THE REGION AS DEEP LAYER RIDGING BUILDS EASTWARD FROM THE GREAT LAKES INTO THE NORTHEAST. SKIES CLEAR FROM WEST TO EAST WITH ANOTHER NIGHT OF BELOW NORMAL TEMPS EXPECTED IN THE TEENS TO 20S. SUNNY CONDITIONS ARE EXPECTED FOR TUESDAY UNDER THE RIDGE WITH TEMPERATURES REBOUNDING INTO THE 40S IN THE AFTERNOON. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 340 AM EDT SUNDAY...SEASONABLE EARLY SPRING TEMPERATURES ALONG WITH PERIODIC CHANCES OF RAIN OR SNOW SHOWERS WILL BE THE RULE DURING THE MIDDLE TO LATER PORTIONS OF NEXT WEEK. BEST SHOT AT PCPN WILL OCCUR TUE NT/WED MORNING...THEN AGAIN BY NEXT WEEKEND. THE MID-WEEK SYSTEM WILL BE RATHER WEAK AS NORTHERN STREAM SHORTWAVE ENERGY PASSES TO OUR NORTH. THUS PCPN SHOULD BE LIGHT AT BEST WITH MANY AREAS REMAINING DRY...ESP ACROSS OUR SOUTHERN COUNTIES. THE SYSTEM FOR NEXT WEEKEND A LITTLE MORE ROBUST SO A BETTER SHOT AREA WIDE FOR RAIN/SNOW SHOWERS. IN BETWEEN (WED AFTERNOON THROUGH FRIDAY MORNING) GENERALLY HIGH PRESSURE WITH CLEAR/PTLY CLOUDY SKIES AND DRY WEATHER EXPECTED. HIGHS GENERALLY IN THE 40S THROUGH THE PERIOD WITH A SPOT 50 HERE AND THERE POSSIBLE WED-FRI. OVERNIGHT LOWS GENERALLY FROM 25 TO 35 THOUGH MAINLY 20S WED NT/THU NT WITH AFOREMENTIONED HIGH PRESSURE IN CONTROL AND BETTER SHOT AT PARTIALLY CLEAR SKIES. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...WIDESPREAD MVFR/IFR ACROSS THE REGION AS WIDESPREAD MIXED PCPN TAPERS TO DRIZZLE OR MUCH LIGHER/SCATTERED RAINS/SNOWS. TERMINAL SPECIFIC DETAILS BELOW... KBTV...MAINLY ON AND OFF LT RAIN OR DRIZZLE TAPERING OFF AFTER 21-00Z. IFR/MVFR FLYING CONDS EXPECTED...WITH MAIN FOCUS OF IFR BEFORE 18Z. WINDS NORTH/NORTHWESTERLY 7-15 AND OCCLY GUSTY TO 20 KTS THIS AFTERNOON...ABATING TO 5 TO 10 KTS AFTER 00Z. KPBG...PERIODS OF LIGHT SNOW OR MIXED LIGHT SNOW/SLEET WITH PATCHY DRIZZLE EXPECTED THROUGH 21-00Z THEN TAPERING OFF. IFR/MVFR CIGS THROUGH THE FORECAST PERIOD...WITH FOCUS OF IFR BEFORE 18Z. WINDS NORTHERLY 10-20 KTS AND OCCNLY GUSTY TODAY...ABATING TO AROUND 10 KTS AFTER 00Z. KMPV...MIX OF LIGHT RAIN/FZRA/FZDZ THROUGH THE FORECAST PERIOD. IFR/MVFR CONDS EXPECTED THROUGH THE PERIOD. WINDS NORTH/NORTHWESTERLY 6-12 KTS. KRUT...PERIODS OF LIGHT RAIN OR DRIZZLE...THROUGH 00Z...WITH PATCHES OF -FZDZ THEREAFTER. MIX OF VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD. WINDS EASTERLY 8 TO 15 KTS WITH GUSTS TO 20 KTS...TRENDING NORTH TO NORTHEASTERLY FROM 18Z ONWARD. KMSS...PERIODS LIGHT SNOW EXPECTED THROUGH 00Z...TAPERING TO SCT SHSN THEREAFTER. IFR FLYING CONDS EXPECTED THROUGH THIS MORNING...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 15 TO 20 KTS WITH GUSTS TO 30 KTS EXPECTED...TRENDING NORTH AROUND 10 KTS AFTER 00Z. CONSIDERABLE BLSN LIKELY THROUGH 21Z. KSLK...LIGHT/MODERATE SNOW EXPECTED WITH SOME MIX OF FZRA/PL POSSIBLE...TAPERING TO SCT SHSN AFTER 18Z. WIDESPREAD IFR...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 6-12 KTS...OCCNL GUSTY TO 20KTS THIS AFTERNOON. OUTLOOK 12Z MONDAY THROUGH THURSDAY... 12Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO EAST AS LIGHT RAIN/SNOW/FZRA TAPERS OFF. BEST SHOT AT CONTINUED LIGHT PMIXED CPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH CONTINUED UNCERTAINTY FURTHER EAST. 18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE. 00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD FRONT CROSSES REGION. 00Z THURSDAY ONWARD...VFR WITH HIGH PRESSURE. && .HYDROLOGY... AS OF 340 AM EDT SUNDAY...COMPLEX HYDRO SITUATION WILL DEVELOP ACROSS OUR SOUTHERN WATERSHEDS TODAY WHERE A SOAKING RAINFALL ON THE ORDER OF 1-1.75 INCHES WILL OCCUR. THIS IS A BLENDED MULTI- MODEL SOLUTION WHICH APPEARS THE BEST COURSE FOR NOW GIVEN CURRENT OBSERVATIONAL DATA. USING THIS QPF AND ALLOWING FOR 0.01-0.03 INCHES OF SWE MELT PER HOUR INDICATES MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET TODAY. WHILE WIDESPREAD OPEN WATER FLOODING IS NOT EXPECTED GIVEN AT LEAST SOME ABSORPTION OF THE RAIN INTO THE EXISTENT "NON-RIPE" SNOWPACK...THESE RISES MAY BE MORE THAN SUFFICIENT TO PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS. THIS SEEMS LOGICAL SEEING ICE MOVEMENT/BREAKUP TYPICALLY OCCURS WHEN RISES ARE ON THE ORDER OF 3X THE ICE THICKNESS. WHILE WE`LL HAVE TO WAIT AND SEE HOW THIS COMPLEX SITUATION PANS OUT...CERTAINLY SOMETHING TO KEEP A CLOSE EYE ON TODAY INTO TONIGHT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER WEATHER ADVISORY UNTIL 11 AM EDT MONDAY FOR VTZ007-008- 010-012-018-019. FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019. WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM EDT MONDAY FOR VTZ011. NY...WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ026>029-035-087. WINTER STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ030- 031-034. && $$ SYNOPSIS...LAHIFF NEAR TERM...RJS/LAHIFF SHORT TERM...LAHIFF LONG TERM...JMG AVIATION...JMG HYDROLOGY...JMG
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
732 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COMPLEX LOW PRESSURE SYSTEM WILL CONTINUE TO BRING MIXED PRECIPITATION TO THE NORTH COUNTRY THIS MORNING...AND TAPER OFF TO DRIZZLE AND FREEZING DRIZZLE THIS AFTERNOON. PORTIONS OF CENTRAL AND SOUTHERN VERMONT WILL CONTINUE TO SEE LIGHT ICE ACCUMULATIONS TONIGHT INTO MONDAY MORNING AS THE LOW TRACKS OFF THE EASTERN SEABOARD...WITH DRIER CONDITIONS RETURNING TO THE ENTIRE REGION BY MONDAY AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 716 AM EDT SUNDAY...QUICK UPDATE TO CANCEL ADVISORIES FOR PORTIONS OF NORTHERN VERMONT AS BULK OF PRECIP SHIFTS NORTH OF THE AREA AND PTYPE TRANSITIONS TO RAIN OR DRIZZLE. PREVIOUS DISCUSSION...FORECAST PLAYING OUT FAIRLY WELL WITH A MYRIAD OF PRECIPITATION TYPES EXPERIENCED ACROSS THE NORTH COUNTRY OVERNIGHT ASSOCIATED WITH LOW PRESSURE MOVING EASTWARD THROUGH THE MID-ATLANTIC STATES. ACROSS VERMONT...PRECIP STARTED OUT AS A MIX OF SNOW...RAIN AND FREEZING RAIN BUT AS OF 5 AM SEEING MAINLY A MIX OF RAIN AND SNOW. MEANWHILE...ACROSS NORTHERN NEW YORK SNOW HAS BEEN THE PREDOMINANT PTYPE WITH SEVERAL INCHES OF SNOW ACCUMULATIONS BEING REPORTED. MODEL OF CHOICE OVERNIGHT HAS BEEN THE RAP WHICH CONTINUES TO HANDLE THE VERTICAL THERMAL STRUCTURE VERY WELL SHOWING +0C LAYER AT 850MB SHIFTING NORTHWARD THROUGH VT WHILE FROM THE SURFACE-925MB REMAINED NEARLY ISOTHERMAL. AS THE BULK OF PRECIP SHIFTS NORTHWARD OUT OF THE REGION THIS MORNING...WE`RE LEFT WITH SUPER-SATURATED LOW LEVELS AND ZERO ICE IN THE FAVORED SNOW GROWTH REGION ALOFT ALONG WITH COOLING MID LEVELS. THIS WILL SUPPORT A TRANSITION TO DRIZZLE AND/OR FREEZING DRIZZLE ACROSS MOST OF THE AREA...THOUGH SOME LINGERING SNOW SHOWERS WILL BE POSSIBLE ACROSS THE SAINT LAWRENCE VALLEY DUE TO COLDER PROFILES. TEMPS WILL BASICALLY GO NOWHERE TODAY UNDER THICK CLOUD COVER AND NORTH TO NORTHEASTERLY FLOW...HOLDING STEADY IN THE LOW/MID 30S TO UPPER 20S AREA-WIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 510 AM EDT SUNDAY...FOR TONIGHT INTO MONDAY...MODELS HAVE COME INTO BETTER AGREEMENT IN REGARDS TO ANOTHER ROUND OF MIXED PRECIPITATION ACROSS CENTRAL AND SOUTHERN VERMONT AS ADDITIONAL SHORTWAVE ENERGY ROTATES AROUND THE SLOWLY DEPARTING UPPER LOW. LOW LEVEL TEMPERATURES COOL ACROSS THE AREA OVERNIGHT WHILE TEMPS AT MID-LEVELS REMAIN ABOVE FREEZING SETTING THE STAGE FOR AREAS OF FREEZING DRIZZLE/RAIN THROUGH MONDAY MORNING. GREATEST CHANCES OF ICE ACCUMULATION WILL BE OVER CENTRAL AND SOUTHEASTERN ZONES DUE TO THE PROXIMITY WITH UPPER LOW....AND WINTER WX ADVISORIES HAVE BEEN EXTENDED FOR A LIGHT GLAZE OF UP TO A TENTH OF AN INCH LIKELY. LATE MONDAY INTO MONDAY NIGHT DRIER CONDITIONS RETURN TO THE REGION AS DEEP LAYER RIDGING BUILDS EASTWARD FROM THE GREAT LAKES INTO THE NORTHEAST. SKIES CLEAR FROM WEST TO EAST WITH ANOTHER NIGHT OF BELOW NORMAL TEMPS EXPECTED IN THE TEENS TO 20S. SUNNY CONDITIONS ARE EXPECTED FOR TUESDAY UNDER THE RIDGE WITH TEMPERATURES REBOUNDING INTO THE 40S IN THE AFTERNOON. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 340 AM EDT SUNDAY...SEASONABLE EARLY SPRING TEMPERATURES ALONG WITH PERIODIC CHANCES OF RAIN OR SNOW SHOWERS WILL BE THE RULE DURING THE MIDDLE TO LATER PORTIONS OF NEXT WEEK. BEST SHOT AT PCPN WILL OCCUR TUE NT/WED MORNING...THEN AGAIN BY NEXT WEEKEND. THE MID-WEEK SYSTEM WILL BE RATHER WEAK AS NORTHERN STREAM SHORTWAVE ENERGY PASSES TO OUR NORTH. THUS PCPN SHOULD BE LIGHT AT BEST WITH MANY AREAS REMAINING DRY...ESP ACROSS OUR SOUTHERN COUNTIES. THE SYSTEM FOR NEXT WEEKEND A LITTLE MORE ROBUST SO A BETTER SHOT AREA WIDE FOR RAIN/SNOW SHOWERS. IN BETWEEN (WED AFTERNOON THROUGH FRIDAY MORNING) GENERALLY HIGH PRESSURE WITH CLEAR/PTLY CLOUDY SKIES AND DRY WEATHER EXPECTED. HIGHS GENERALLY IN THE 40S THROUGH THE PERIOD WITH A SPOT 50 HERE AND THERE POSSIBLE WED-FRI. OVERNIGHT LOWS GENERALLY FROM 25 TO 35 THOUGH MAINLY 20S WED NT/THU NT WITH AFOREMENTIONED HIGH PRESSURE IN CONTROL AND BETTER SHOT AT PARTIALLY CLEAR SKIES. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...WIDESPREAD MVFR/IFR ACROSS THE REGION AS WIDESPREAD MIXED PCPN TAPERS TO DRIZZLE OR MUCH LIGHER/SCATTERED RAINS/SNOWS. TERMINAL SPECIFIC DETAILS BELOW... KBTV...MAINLY ON AND OFF LT RAIN OR DRIZZLE TAPERING OFF AFTER 21-00Z. IFR/MVFR FLYING CONDS EXPECTED...WITH MAIN FOCUS OF IFR BEFORE 18Z. WINDS NORTH/NORTHWESTERLY 7-15 AND OCCLY GUSTY TO 20 KTS THIS AFTERNOON...ABATING TO 5 TO 10 KTS AFTER 00Z. KPBG...PERIODS OF LIGHT SNOW OR MIXED LIGHT SNOW/SLEET WITH PATCHY DRIZZLE EXPECTED THROUGH 21-00Z THEN TAPERING OFF. IFR/MVFR CIGS THROUGH THE FORECAST PERIOD...WITH FOCUS OF IFR BEFORE 18Z. WINDS NORTHERLY 10-20 KTS AND OCCNLY GUSTY TODAY...ABATING TO AROUND 10 KTS AFTER 00Z. KMPV...MIX OF LIGHT RAIN/FZRA/FZDZ THROUGH THE FORECAST PERIOD. IFR/MVFR CONDS EXPECTED THROUGH THE PERIOD. WINDS NORTH/NORTHWESTERLY 6-12 KTS. KRUT...PERIODS OF LIGHT RAIN OR DRIZZLE...THROUGH 00Z...WITH PATCHES OF -FZDZ THEREAFTER. MIX OF VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD. WINDS EASTERLY 8 TO 15 KTS WITH GUSTS TO 20 KTS...TRENDING NORTH TO NORTHEASTERLY FROM 18Z ONWARD. KMSS...PERIODS LIGHT SNOW EXPECTED THROUGH 00Z...TAPERING TO SCT SHSN THEREAFTER. IFR FLYING CONDS EXPECTED THROUGH THIS MORNING...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 15 TO 20 KTS WITH GUSTS TO 30 KTS EXPECTED...TRENDING NORTH AROUND 10 KTS AFTER 00Z. CONSIDERABLE BLSN LIKELY THROUGH 21Z. KSLK...LIGHT/MODERATE SNOW EXPECTED WITH SOME MIX OF FZRA/PL POSSIBLE...TAPERING TO SCT SHSN AFTER 18Z. WIDESPREAD IFR...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 6-12 KTS...OCCNL GUSTY TO 20KTS THIS AFTERNOON. OUTLOOK 12Z MONDAY THROUGH THURSDAY... 12Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO EAST AS LIGHT RAIN/SNOW/FZRA TAPERS OFF. BEST SHOT AT CONTINUED LIGHT PMIXED CPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH CONTINUED UNCERTAINTY FURTHER EAST. 18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE. 00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD FRONT CROSSES REGION. 00Z THURSDAY ONWARD...VFR WITH HIGH PRESSURE. && .HYDROLOGY... AS OF 340 AM EDT SUNDAY...COMPLEX HYDRO SITUATION WILL DEVELOP ACROSS OUR SOUTHERN WATERSHEDS TODAY WHERE A SOAKING RAINFALL ON THE ORDER OF 1-1.75 INCHES WILL OCCUR. THIS IS A BLENDED MULTI- MODEL SOLUTION WHICH APPEARS THE BEST COURSE FOR NOW GIVEN CURRENT OBSERVATIONAL DATA. USING THIS QPF AND ALLOWING FOR 0.01-0.03 INCHES OF SWE MELT PER HOUR INDICATES MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET TODAY. WHILE WIDESPREAD OPEN WATER FLOODING IS NOT EXPECTED GIVEN AT LEAST SOME ABSORPTION OF THE RAIN INTO THE EXISTENT "NON-RIPE" SNOWPACK...THESE RISES MAY BE MORE THAN SUFFICIENT TO PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS. THIS SEEMS LOGICAL SEEING ICE MOVEMENT/BREAKUP TYPICALLY OCCURS WHEN RISES ARE ON THE ORDER OF 3X THE ICE THICKNESS. WHILE WE`LL HAVE TO WAIT AND SEE HOW THIS COMPLEX SITUATION PANS OUT...CERTAINLY SOMETHING TO KEEP A CLOSE EYE ON TODAY INTO TONIGHT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER WEATHER ADVISORY UNTIL 11 AM EDT MONDAY FOR VTZ007-008- 010-012-018-019. FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019. WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM EDT MONDAY FOR VTZ011. NY...WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ026>029-035-087. WINTER STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ030- 031-034. && $$ SYNOPSIS...LAHIFF NEAR TERM...LAHIFF SHORT TERM...LAHIFF LONG TERM...JMG AVIATION...JMG HYDROLOGY...JMG
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
717 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COMPLEX LOW PRESSURE SYSTEM WILL CONTINUE TO BRING MIXED PRECIPITATION TO THE NORTH COUNTRY THIS MORNING...AND TAPER OFF TO DRIZZLE AND FREEZING DRIZZLE THIS AFTERNOON. PORTIONS OF CENTRAL AND SOUTHERN VERMONT WILL CONTINUE TO SEE LIGHT ICE ACCUMULATIONS TONIGHT INTO MONDAY MORNING AS THE LOW TRACKS OFF THE EASTERN SEABOARD...WITH DRIER CONDITIONS RETURNING TO THE ENTIRE REGION BY MONDAY AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 716 AM EDT SUNDAY...QUICK UPDATE TO CANCEL ADVISORIES FOR PORTIONS OF NORTHERN VERMONT AS BULK OF PRECIP SHIFTS NORTH OF THE AREA AND PTYPE TRANSITIONS TO RAIN OR DRIZZLE. PREVIOUS DISCUSSION...FORECAST PLAYING OUT FAIRLY WELL WITH A MYRIAD OF PRECIPITATION TYPES EXPERIENCED ACROSS THE NORTH COUNTRY OVERNIGHT ASSOCIATED WITH LOW PRESSURE MOVING EASTWARD THROUGH THE MID-ATLANTIC STATES. ACROSS VERMONT...PRECIP STARTED OUT AS A MIX OF SNOW...RAIN AND FREEZING RAIN BUT AS OF 5 AM SEEING MAINLY A MIX OF RAIN AND SNOW. MEANWHILE...ACROSS NORTHERN NEW YORK SNOW HAS BEEN THE PREDOMINANT PTYPE WITH SEVERAL INCHES OF SNOW ACCUMULATIONS BEING REPORTED. MODEL OF CHOICE OVERNIGHT HAS BEEN THE RAP WHICH CONTINUES TO HANDLE THE VERTICAL THERMAL STRUCTURE VERY WELL SHOWING +0C LAYER AT 850MB SHIFTING NORTHWARD THROUGH VT WHILE FROM THE SURFACE-925MB REMAINED NEARLY ISOTHERMAL. AS THE BULK OF PRECIP SHIFTS NORTHWARD OUT OF THE REGION THIS MORNING...WE`RE LEFT WITH SUPER-SATURATED LOW LEVELS AND ZERO ICE IN THE FAVORED SNOW GROWTH REGION ALOFT ALONG WITH COOLING MID LEVELS. THIS WILL SUPPORT A TRANSITION TO DRIZZLE AND/OR FREEZING DRIZZLE ACROSS MOST OF THE AREA...THOUGH SOME LINGERING SNOW SHOWERS WILL BE POSSIBLE ACROSS THE SAINT LAWRENCE VALLEY DUE TO COLDER PROFILES. TEMPS WILL BASICALLY GO NOWHERE TODAY UNDER THICK CLOUD COVER AND NORTH TO NORTHEASTERLY FLOW...HOLDING STEADY IN THE LOW/MID 30S TO UPPER 20S AREA-WIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 510 AM EDT SUNDAY...FOR TONIGHT INTO MONDAY...MODELS HAVE COME INTO BETTER AGREEMENT IN REGARDS TO ANOTHER ROUND OF MIXED PRECIPITATION ACROSS CENTRAL AND SOUTHERN VERMONT AS ADDITIONAL SHORTWAVE ENERGY ROTATES AROUND THE SLOWLY DEPARTING UPPER LOW. LOW LEVEL TEMPERATURES COOL ACROSS THE AREA OVERNIGHT WHILE TEMPS AT MID-LEVELS REMAIN ABOVE FREEZING SETTING THE STAGE FOR AREAS OF FREEZING DRIZZLE/RAIN THROUGH MONDAY MORNING. GREATEST CHANCES OF ICE ACCUMULATION WILL BE OVER CENTRAL AND SOUTHEASTERN ZONES DUE TO THE PROXIMITY WITH UPPER LOW....AND WINTER WX ADVISORIES HAVE BEEN EXTENDED FOR A LIGHT GLAZE OF UP TO A TENTH OF AN INCH LIKELY. LATE MONDAY INTO MONDAY NIGHT DRIER CONDITIONS RETURN TO THE REGION AS DEEP LAYER RIDGING BUILDS EASTWARD FROM THE GREAT LAKES INTO THE NORTHEAST. SKIES CLEAR FROM WEST TO EAST WITH ANOTHER NIGHT OF BELOW NORMAL TEMPS EXPECTED IN THE TEENS TO 20S. SUNNY CONDITIONS ARE EXPECTED FOR TUESDAY UNDER THE RIDGE WITH TEMPERATURES REBOUNDING INTO THE 40S IN THE AFTERNOON. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 340 AM EDT SUNDAY...SEASONABLE EARLY SPRING TEMPERATURES ALONG WITH PERIODIC CHANCES OF RAIN OR SNOW SHOWERS WILL BE THE RULE DURING THE MIDDLE TO LATER PORTIONS OF NEXT WEEK. BEST SHOT AT PCPN WILL OCCUR TUE NT/WED MORNING...THEN AGAIN BY NEXT WEEKEND. THE MID-WEEK SYSTEM WILL BE RATHER WEAK AS NORTHERN STREAM SHORTWAVE ENERGY PASSES TO OUR NORTH. THUS PCPN SHOULD BE LIGHT AT BEST WITH MANY AREAS REMAINING DRY...ESP ACROSS OUR SOUTHERN COUNTIES. THE SYSTEM FOR NEXT WEEKEND A LITTLE MORE ROBUST SO A BETTER SHOT AREA WIDE FOR RAIN/SNOW SHOWERS. IN BETWEEN (WED AFTERNOON THROUGH FRIDAY MORNING) GENERALLY HIGH PRESSURE WITH CLEAR/PTLY CLOUDY SKIES AND DRY WEATHER EXPECTED. HIGHS GENERALLY IN THE 40S THROUGH THE PERIOD WITH A SPOT 50 HERE AND THERE POSSIBLE WED-FRI. OVERNIGHT LOWS GENERALLY FROM 25 TO 35 THOUGH MAINLY 20S WED NT/THU NT WITH AFOREMENTIONED HIGH PRESSURE IN CONTROL AND BETTER SHOT AT PARTIALLY CLEAR SKIES. && .AVIATION /11Z SUNDAY THROUGH THURSDAY/... THROUGH 06Z MONDAY...WIDESPREAD MVFR/IFR ACROSS THE REGION IN MODERATE TO HEAVY MIXED PCPN AND/OR RAIN AS LOW PRESSURE ALONG THE NORTHERN MID-ATLANTIC COAST DRAWS COPIOUS MOISTURE NORTHWARD. TERMINAL SPECIFIC DETAILS BELOW... KBTV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD W/BRIEF IFR POSSIBLE. WINDS NORTH/NORTHWESTERLY 7-15 KTS. KMPV...MIX OF RAIN/FZRA THROUGH 12Z...THEN MAINLY LT RAIN TAPERING TO SHOWERS AFTER 18Z. IFR/MVFR CONDS EXPECTED THROUGH THE PERIOD. WINDS LGT AND VRB THROUGH 12Z...THEN NORTH/NORTHWESTERLY 6-12 KTS THEREAFTER. KRUT...PERIODS OF LIGHT RAIN...TAPERING TO SHOWERS BY 18Z. MIX OF VFR/MVFR FLYING CONDS EXPECTED THROUGH THE PERIOD. WINDS EASTERLY 8 TO 15 KTS WITH GUSTS TO 20 KTS...TRENDING NORTH TO NORTHEASTERLY AFTER 12Z. KPBG...LIGHT TO MODERATE SNOW THROUGH 10-12Z...THEN MIXING WITH SLEET. IFR LIKELY THROUGH 15Z...TRENDING MVFR THEREAFTER. SOME MIX WITH RAIN ALSO POSSIBLE AFTER 16Z BEFORE PCPN TAPERS TO SHOWERS. WINDS NORTHERLY 10-18 KTS AND TRENDING GUSTY TO 25 KTS THIS AFTERNOON. KMSS...LIGHT TO MODERATE SNOW EXPECTED THROUGH MUCH OF THE PERIOD...TAPERING TO SCT SHSN AFTER 00Z MONDAY. IFR FLYING CONDS EXPECTED THROUGH AFTERNOON...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 15 TO 22 KTS WITH GUSTS TO 30 KTS EXPECTED...ABATING SLIGHTLY TOWARD EVENING. CONSIDERABLE BLSN LIKELY. KSLK...LIGHT/MODERATE SNOW EXPECTED WITH SOME MIX OF FZRA/PL POSSIBLE...TAPERING TO SCT SHSN/SHRA AFTER 18Z. WIDESPREAD IFR...TRENDING MVFR AFTER 18Z. WINDS NORTHEASTERLY 6-12 KTS...OCCNL GUSTY TO 20KTS THIS AFTERNOON. OUTLOOK 06Z MONDAY THROUGH THURSDAY... 06Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO EAST AS LIGHT RAIN/SNOW TAPERS OFF. BEST SHOT AT CONTINUED LIGHT PCPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH CONTINUED UNCERTAINTY FURTHER EAST. 18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE. 00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD FRONT CROSSES REGION. 00Z THURSDAY ONWARD...VFR W/MVFR PSBL LATE THURSDAY AS WARM FRONT APPROACHES FROM SW...BRINGING PRECIP SOUTH TO NORTH. && .HYDROLOGY... AS OF 340 AM EDT SUNDAY...COMPLEX HYDRO SITUATION WILL DEVELOP ACROSS OUR SOUTHERN WATERSHEDS TODAY WHERE A SOAKING RAINFALL ON THE ORDER OF 1-1.75 INCHES WILL OCCUR. THIS IS A BLENDED MULTI- MODEL SOLUTION WHICH APPEARS THE BEST COURSE FOR NOW GIVEN CURRENT OBSERVATIONAL DATA. USING THIS QPF AND ALLOWING FOR 0.01-0.03 INCHES OF SWE MELT PER HOUR INDICATES MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET TODAY. WHILE WIDESPREAD OPEN WATER FLOODING IS NOT EXPECTED GIVEN AT LEAST SOME ABSORPTION OF THE RAIN INTO THE EXISTENT "NON-RIPE" SNOWPACK...THESE RISES MAY BE MORE THAN SUFFICIENT TO PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS. THIS SEEMS LOGICAL SEEING ICE MOVEMENT/BREAKUP TYPICALLY OCCURS WHEN RISES ARE ON THE ORDER OF 3X THE ICE THICKNESS. WHILE WE`LL HAVE TO WAIT AND SEE HOW THIS COMPLEX SITUATION PANS OUT...CERTAINLY SOMETHING TO KEEP A CLOSE EYE ON TODAY INTO TONIGHT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER WEATHER ADVISORY UNTIL 11 AM EDT MONDAY FOR VTZ007-008- 010-012-018-019. FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019. WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM EDT MONDAY FOR VTZ011. NY...WINTER WEATHER ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ026>029-035-087. WINTER STORM WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR NYZ030- 031-034. && $$ SYNOPSIS...LAHIFF NEAR TERM...LAHIFF SHORT TERM...LAHIFF LONG TERM...JMG AVIATION...BANACOS/JMG HYDROLOGY...JMG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EDT SUN MAR 30 2014 .SYNOPSIS... A COLD FRONT WILL SWEEP EAST THROUGH CENTRAL NORTH CAROLINA EARLY THIS MORNING... AND WILL BE FOLLOWED BY BRISK AND GUSTY WINDS FROM THE NORTHWEST PULLING COOLER AIR INTO THE REGION. HIGH PRESSURE WILL BUILD IN FROM THE WEST TONIGHT INTO EARLY NEXT WEEK. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 300 AM SUNDAY... UPDATE FROM 650 AM: LATEST RAP MODEL FORECAST SOUNDINGS INDICATES A VERTICAL THERMAL STRUCTURE SUPPORTIVE OF A CHANCE OF A LITTLE WET SNOW MIXED IN WITH THE LIGHT RAIN OVER THE TRIAD FOR THE NEXT FEW HOURS. OUR WEATHER OBSERVER AT GSO AIRPORT JUST REPORTED A FEW FLAKES MIXED IN WITH THE LIGHT SHOWERS THERE RECENTLY. WITH A FAIRLY DRY SUBCLOUD LAYER... STILL EXPECT VERY LOW PRECIP AMOUNTS... BUT THE WET BULB BRIEFLY DROPS CLOSE TO FREEZING AT THE SURFACE EARLY THIS MORNING IN THE TRIAD REGION... WITH THE REMAINDER OF THE COLUMN BELOW FREEZING. HAVE INCLUDED A MENTION OF A FEW SNOWFLAKES OVER THE NEXT FEW HOURS IN THE NW CWA. -GIH THE PRIMARY WEATHER CONCERN TODAY IS THE STRONG GUSTY NW WINDS AND POTENTIALLY ADVERSE IMPACTS SUCH AS DOWNED BRANCHES AND WEAKLY ROOTED TREES. CURRENTLY... SHORT BANDS OF SHOWERS PRODUCING LOCALLY ENHANCED WINDS CONTINUE TO PIVOT AROUND THE MID LEVEL LOW OVER SW VA THIS MORNING... MAINLY AFFECTING THE NRN CWA AS POCKETS OF VORTICITY STREAK TO THE NNE ON THE SRN/ERN SIDE OF THE LOW. THIS LOW IS EXPECTED TO TRACK EASTWARD ALONG THE NC/VA STATE LINE THROUGH MIDDAY... SHIFTING NE OFF THE TIDEWATER/DELMARVA SHORE DURING THE MID TO LATE AFTERNOON... AND IT`S EXPECTED TO BRING PATCHY SHOWERS (MOVING MORE WEST-TO-EAST) THROUGH MID AFTERNOON ACROSS OUR NRN CWA... WHERE FORECAST SOUNDINGS AND EXTRAPOLATION OF UPSTREAM CONDITIONS SUPPORT A RATHER DEEP LAYER OF MOISTURE AT 850-700 MB. THE COMPARATIVELY DRY AND WELL-MIXED SUBCLOUD LAYER HOWEVER WILL GREATLY LIMIT QPF. REGARDING TODAY`S WIND... THE MSLP GRADIENT BETWEEN THE DEEP SURFACE LOW ANALYZED OVER THE CHESAPEAKE BAY/SRN DELMARVA AND THE INCOMING SURFACE HIGH FROM THE WEST TIGHTENS UP THIS MORNING... AND STATISTICAL GUIDANCE AS WELL AS HIGH-RES MODEL OUTPUT SUCH AS THE HRRR AND LOCAL WRF ALL SUPPORT SUSTAINED WINDS OF 15-25 MPH MAINLY OVER THE WRN AND SRN HALVES OF THE CENTRAL NC FORECAST AREA... AND TRANSPORT OF MOMENTUM WITHIN THE GROWING MIXED LAYER INDICATES GUSTS OF 30-36 KTS OVER THIS SAME AREA. WHILE THESE SPEEDS MAY NOT QUITE REACH OUR WIND ADVISORY CRITERIA EVERYWHERE... THE ANTICIPATED IMPACTS (A FEW DOWNED BRANCHES/TREES AND SPORADIC POWER OUTAGES) WARRANT ISSUANCE OF A WIND ADVISORY... TO BE IN EFFECT FOR AREAS WEST AND SOUTH OF THE TRIANGLE THROUGH MID EVENING (WHEN WINDS ARE EXPECTED TO SUBSIDE). BELOW-NORMAL LOW LEVEL THICKNESSES COMBINED WITH CONSIDERABLE CLOUDINESS PARTICULARLY OVER THE NRN TWO-THIRDS OF THE CWA WILL HOLD TEMPS DOWN TODAY... AND EXPECT HIGHS OF 53-62... AROUND 10-12 DEGREES BELOW NORMAL. THE DEPARTURE OF THE SURFACE AND MID LEVEL LOWS TO OUR NE AFTER NIGHTFALL AND STRONG SUBSIDENCE (100-120 M MID LEVEL HEIGHT RISES) SHOULD FOSTER QUICK CLEARING FROM WSW TO ENE. WINDS WILL DECREASE BUT SHOULD STILL HOLD UP ENOUGH TO KEEP THE LOW LEVELS STIRRED OVERNIGHT... KEEPING TEMPS FROM FALLING DOWN TO THE FORECAST DEW POINTS (WHICH SHOULD FALL TO THE MID 20S TO AROUND 30). AS SUCH... EXPECT LOWS TO STAY ABOVE FREEZING TONIGHT. DESPITE LOWS IN THE MID 30S IN MANY AREAS... THE DRY AIR SHOULD LIMIT FROST DEVELOPMENT TONIGHT... BUT WILL TAKE ANOTHER LOOK AT THIS LATER TODAY. LOWS MAINLY 35-40. -GIH && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 315 AM SUNDAY... PLENTY OF SUNSHINE EXPECTED MONDAY... WITH CONTINUED DRY AIR ADVECTION THROUGH THE COLUMN AND HIGH PRESSURE STARTING TO BUILD IN AT THE SURFACE... AND MID LEVEL RIDGING APPROACHING FROM THE WEST. A BREEZE OUT OF THE NW SHOULD PERSIST BUT NOT NEARLY AS STRONG AS WE SHOULD SEE TODAY. LOW LEVEL THICKNESSES RECOVER NICELY TO NEAR- NORMAL LEVELS MON MORNING AND RISE QUICKLY THROUGH THE DAY... SUPPORTING HIGHS FROM THE UPPER 60S NE TO MID 70S SW... A BIT ABOVE NORMAL FOR THIS TIME OF YEAR. EXPECT GOOD RADIATIONAL COOLING MON NIGHT... ALTHOUGH THE INCREASING SURFACE DEW POINTS MON NIGHT WILL OFFSET THE CALM TO VERY LIGHT WINDS TO KEEP TEMPS FROM FALLING TOO MUCH. LOWS 38-42... JUST SLIGHTLY BELOW NORMAL. -GIH && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 255 AM SUNDAY... A SUBTROPICAL RIDGE WILL DEVELOP OVER THE SOUTHEAST US BY TUESDAY WITH A SURFACE HIGH OFF THE SOUTHEAST COAST. THIS WARM PATTERN...WITH LOW LEVEL THICKNESSES CLIMBING ABOVE 1370M...WILL SUPPORT HIGHS IN THE MID AND UPPER 70S EACH DAY...WITH LOWER 80S NOT OUT OF THE QUESTION ACROSS THE SOUTH AND EAST WEDNESDAY AND THURSDAY. A SHORTWAVE LIFTING THROUGH THE GREAT LAKES REGION WILL SEND A MOSTLY DRY COLD FRONT INTO THE MID-ATLANTIC STATES TUESDAY AFTERNOON...BUT GIVEN THE STRENGTH OF THE RIDGE...EXPECT THIS FRONT OR REMNANT TROUGH TO REMAIN NORTH OF THE AREA. A MORE VIGOROUS SYSTEM IS FORECAST TO LIFT THROUGH THE MIDWEST STATES ON FRIDAY...THOUGH THE GFS AND ECMWF DIFFER REGARDING THE STRENGTH OF THE WAVE AND THE TIMING OF THE ASSOCIATED COLD FRONT. PREFER A SOLUTION SLOWER THAN THE ECMWF ON FRIDAY...BUT NOT AS SLOW AS THE GFS WHICH DOESNT BRING THE FRONT IN UNTIL SATURDAY. NEITHER SOLUTION LOOKS TO DRAW A TON OF MOISTURE FROM THE GULF...SO WILL KEEP POPS CAPPED AT SLIGHT CHANCE NOW BASED ON THE PATTERN AND MODEL DIFFERENCES. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... AS OF 650 AM SUNDAY... THE BIGGEST AVIATION CONCERN TODAY IS THE STRONG SURFACE WINDS FROM THE NW... INCREASING TO 15-20 KTS GUSTING TO 25-35 KTS... STRONGEST AFTER 17Z THIS AFTERNOON AS OUR LOW LEVELS MIX MORE DEEPLY. THIS MAY POSE A CROSSWIND THREAT FOR AIRCRAFT AT GSO/RDU/FAY/RWI. CURRENT CIGS ARE MOSTLY VFR... ALTHOUGH PATCHY SHOWERS ACROSS THE AREA MAY BRIEFLY REDUCE CIGS TO MVFR BRIEFLY THIS MORNING. OTHERWISE... WITH EARLY-DAY HEATING AND RESIDUAL MOISTURE ALOFT... EXPECT TO SEE A PERIOD OF HIGH-END MVFR CIGS (2000-3000 FT AGL) MAINLY AT RDU/RWI BETWEEN 12Z AND 17Z THIS MORNING/MIDDAY. THESE CIGS SHOULD LIFT TO VFR SOON AFTER 17Z. ELSEWHERE... ANY CIGS ARE LIKELY TO BE VFR... AND VSBYS WILL BE VFR AREAWIDE THROUGH TONIGHT. WINDS WILL DECREASE THIS EVENING (AFTER 01Z) TO 10-15 KTS WITH ONLY SPORADIC GUSTS TO 20 KTS FROM THE NW THROUGH THE END OF THE TAF VALID PERIOD. LOOKING BEYOND 12Z MONDAY MORNING: HIGH CONFIDENCE IN VFR CONDITIONS AT ALL SITES THROUGH THURSDAY... AS HIGH PRESSURE BUILDS OVER THE REGION AND REMAINS OVER AND JUST OFF THE SOUTHEAST COAST THROUGH MIDWEEK. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR NCZ007-021>024- 038>040-073>077-083>086-088. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...SMITH AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1053 AM EDT SUN MAR 30 2014 .SYNOPSIS... AN UPPER LEVEL LOW WILL SHIFT OFF THE COAST THIS AFTERNOON. HIGH PRESSURE WILL RETURN TO THE AREA LATE TONIGHT AND MONDAY. A FRONT MOVES THROUGH BY TUESDAY NIGHT BUT LOOKS DRY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1030 AM EDT SUNDAY... PERSISTENT BANDS OF HEAVY SNOW CONTINUE TO SPILL SOUTH FROM BATH COUNTY EAST TO AMHERST WITH ELEVATION ALLOWING SNOW TO QUICKLY ACCUMULATE TO BETTER THAN 6 INCHES IN STRIPS ALONG THE I-64 TO I-81 CORRIDOR UP NORTH. LATEST RAP AND LOCAL MODEL SOLNS SUGGEST ANOTHER HOUR OR SO OF ACCUMULATING SNOWFALL IN THESE AREAS BEFORE THE DEFORMATION AREA FINALLY SHIFTS SE AND WEAKENS. THUS WILL KEEP THE ADVISORY GOING ACROSS PARTS OF THE SOUTHERN SHENANDOAH VALLEY WHILE INCLUDING LOCALLY HIGHER TOTALS GIVEN THE HUGE RANGE ACROSS COUNTIES WITH LITTLE AT LOWER ELEVATIONS. ELSEWHERE SHOULD BE WARM ENOUGH FOR MOSTLY RAIN FARTHER SOUTH WITH ONLY SOME SNOW MIXED IN NORTH OF HIGHWAY 460 FOR A WHILE LONGER. PRECIP HAS TAPERED WEST OF THE NEW RIVER VALLEY SO WILL BE REMOVING COUNTIES FROM THE WINTER WX ADVISORY THERE WHILE KEEPING THE WARNINGS GOING INTO SE WVA GIVEN SOME CONTININUING LIGHT SNOWFALL. LITTLE CHANGE TO GOING WIND HEADLINES WITH THE STRONGEST SPEEDS CONTINUING ALONG THE SOUTHERN BLUE RIDGE BUT LIKELY TO SHIFT NE AS SOME BREAKS DEVELOP THIS AFTERNOON UNDER A SECONDARY LOW LEVEL JET MAX THAT LOOKS TO PIVOT ACROSS BY MID AFTERNOON. BEEFED UP CLOUDS LONGER PER LATEST VIS PICS WITH TEMPS REMAINING BELOW MOS SO LOWERED A CAT OR SO ACROSS THE REGION FOR THE AFTERNOON. AS OF 915 AM EDT SUNDAY... QUICK UPDATE TO ADD THE HIGHER ELEVATIONS OF ROCKBRIDGE AND AMHERST TO THE GOING WINTER WEATHER ADVISORY DUE TO HEAVIER SNOW BANDS ON THE BACK EDGE OF THE DEFORMATION ZONE. EXPECT MOST ACCUMULATION TO BE NEAR THE BLUE RIDGE PARKWAY WITH LESS THAN AN INCH ELSEWHERE ACROSS THAT REGION. ALSO BUMPED UP AMOUNTS ACROSS NORTHERN BATH WHERE HAVE ALREADY SEEN 2-3 INCHES. REMAINDER UNCHANGED AS EXPECT LESS AND LESS ACCUMULATION WITH SOME SLOW WARMING DURING THE MORNING HOURS. STRONGER WINDS ALONG THE BLUE RIDGE MAY BE REALIZED OVER THE NEXT FEW HOURS BUT WILL NEED SOME CLEARING TO ENHANCE MIXING WHICH MAY NOT HAPPEN IN TIME BUT WILL CONTINUE THE WARNING FOR NOW. PREVIOUS DISCUSSION AS OF 720 AM EDT SUNDAY... RADAR CONTINUES TO SHOW DEFORMATION AXIS PIEDMONT WITH NW FLOW RAIN AND SNOW SHOWERS OVER THE WEST. RADAR OVERSHOOTING THE SNOW PAST I-77 AND IN NC MTNS. MODELS AGREE THAT DRYING TAKES PLACE FROM SW TO NE THROUGH THE MORNING AND WILL SEE SNOW SHOWERS AND RAIN OUT EAST START TO WANE LATE MORNING INTO MID AFTERNOON. STILL LOOKS LIKE A GOOD 2-6 INCHES POSSIBLE OF SNOW IN THE HIGHER ELEVATIONS...AND SOME POCKETS OF 1-3 INCHES IN NARROW CORRIDORS FROM SE WV INTO THE NW NC MTNS AND NEW RIVER VALLEY. WIND WILL KEEP THE SNOW MEASURING AN ISSUE...AND OVERALL WINDS WILL BE GUSTY BUT STRONGEST WINDS WILL ARRIVE AS CLEARING TAKES PLACE AND STILL LOOKING AFTERNOON FOR MOST. ALREADY HAVE HAD GUSTS OVER 65 MPH AT BOONE...AND A TREE DOWN IN TODD NC. NO CHANGES WERE MADE TO THE HEADLINES. PREVIOUS DISCUSSION ISSUED EARLIER THIS MORNING... OVERALL...MARCH IS TRYING TO GO OUT LIKE A LION...BUT IT WILL HAVE TO SETTLE FOR THE DAY BEFORE THE END OF THE MONTH. RADAR THIS MORNING SHOWS THE DEFORMATION ZONE PRECIP LIFTING NWD ACROSS THE ALLEGHANY HIGHLANDS SOUTHEAST TOWARD SOUTHSIDE VA. THE PRECIP OVER THE MOUNTAINS HAS CHANGED TO ALL SNOW...BUT SO FAR LITTLE ACCUMULATION REPORTS...ALTHOUGH THINK MORE WILL BE COMING IN AS WE HEAD TOWARD DAYLIGHT HOURS. NICE CYCLONIC FLOW SEEN IN THE RADAR ECHOES AS WELL...WITH UPSLOPE WELL UNDER WAY OVER THE NC MTNS...NWD INTO SE WV. HAVE NOT MADE ANY ADDITIONAL CHANGES TO THE HEADLINES...BUT THE WINDS WILL BE HIT AND MISS THIS MORNING THANKS TO THE CLOUD COVER. AS WE HEAD THRU THE DAY...THE UPPER LOW WILL MOVE EAST OF THE DELMARVA WITH STRONG NVA ARRIVING WHICH HELPS TO MIX OUT THE CLOUDS. FORECAST MOS GUIDANCE AND BUFKIT SOUNDINGS STILL SUGGEST STRONG WINDS ESPECIALLY THIS AFTERNOON. SOME AREAS WILL NOT REALLY GET TO ADVISORY OR WARNING LEVELS BUT GIVEN WET GROUNDS...WIND SPEEDS JUST BELOW WILL CAUSE SOME PROBLEMS. WHERE THE WARNING IS IN PLACE...THINK 50 TO 60 MPH GUSTS ARE LIKELY AND FEEL THAT TREES ARE GOING TO BE BLOWN DOWN. HOPEFULLY...NO DAMAGE TO HOMES OR BUSINESSES WILL OCCUR. ADVISORY AREAS WILL BE MORE FORTUNATE BUT EXPECT SOME TREE DOWN REPORTS AS WELL. THE SNOW WILL ALSO TAPER OFF THIS AFTERNOON AS THE UPPER LOW MOVES AWAY. STILL LOOKS LIKE ELEVATIONS ABOVE 3000 FT WILL GET AS MUCH AS 6 INCHES WHEN ALL IS SAID AND DONE...ESPECIALLY WRN GREENBRIER. MOIST/WET GROUND WILL HAVE SOME IMPACT ON STICKING...BUT RATE SHOULD BE HIGH ENOUGH TO GIVE THE HIGHER VALLEYS IN THE WEST A 1-2 INCH COATING. THOUGH NO ADVISORY IS IN PLACE FOR SNOW ALONG THE BLUE RIDGE...THINK LOCATIONS SUCH AS POOR MOUNTAIN...PEAKS OF OTTER AND APPLE ORCHARD MOUNTAIN COULD SEE 1 TO 3 INCHES OF SNOW. HIGHS TODAY WILL BE TRICKY GIVEN COLD AIR ADVECTION THIS MORNING...THEN NEUTRAL ADVECTION THIS AFTERNOON...PLUS LATE MARCH SUN AND DOWNSLOPE. WENT WITH MID 50S EAST OF THE BLUE RIDGE...TO 40S WEST...WITH 30S IN THE HIGHEST ELEVATIONS FROM BEECH MTN NC...MOUNT ROGERS VA AND THE WRN SLOPES OF GREENBRIER COUNTY. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 329 AM EDT SUNDAY... THE CLOSED LOW THAT WILL TRACK OVER THE FORECAST AREA TODAY WILL BECOME AN OCCLUDED LOW OFF THE DELMARVA COAST THIS EVENING. THE ASSOCIATED PRECIPITATION WITH THIS SYSTEM SHOULD BE EAST OF THE PIEDMONT BY SUNSET. MEANWHILE...HIGH PRESSURE WILL DRIFT EAST OVER THE OHIO-TENN VALLEYS TONIGHT. THE PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS WILL CONTINUE TO PRODUCE WINDY/GUSTY CONDITIONS INTO THE EVENING. THE PRESSURE GRADIENT STARTS TO LOOSEN AFTER MIDNIGHT ALLOWING WINDS TO WEAKEN ACROSS THE FOOTHILLS AND PIEDMONT. WINDY CONDITIONS WILL REMAIN ACROSS THE MOUNTAINS...PARTICULARLY ALONG THE BLUE RIDGE INTO THE EARLY MORNING HOURS MONDAY. OVERNIGHT MIXING WILL KEEP RIDGE TOP TEMPERATURES MILDER THAN THE VALLEYS. MOUNTAIN VALLEY TEMPERATURES WILL RANGE IN THE M/U20S WHILE RIDGES RANGE BETWEEN 30F-35F. EVEN THOUGH THE WINDS RELAX IN THE EAST EARLY...NOT AN IDEAL SITUATION FOR RADIATIONAL COOLING...THEREFORE KEPT OVERNIGHT TEMPERATURES IN THE 30S. WHAT A DIFFERENCE A DAY MAKES WITH MONDAYS HIGH TEMPERATURES IN THE 60S ACROSS THE WEST AND U60S-L70S IN THE EAST. RELATIVE HUMIDITIES WILL DROP INTO THE 20S MONDAY AFTERNOON WHILE NORTHWEST WINDS PEAK BETWEEN 10-15 MPH. WARMER TUESDAY WITH TEMPERATURES PUSHING 70F ACROSS THE MOUNTAINS AND WIDESPREAD 70S EAST. HUMIDITY LEVELS SLIGHTLY HIGHER AROUND 30 PERCENT TUESDAY WITH THE LOW LEVEL FLOW COMING FROM THE SOUTHWEST. BOTH DAYS LOOK IDEAL FOR PRESCRIBE BURNS WITH THE STRONGER TRANSPORT WINDS OCCURRING TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 1145 AM EDT SATURDAY... BROAD UPPER RIDGING TO REMAIN IN PLACE UNTIL NEAR THE END OF THE PERIOD WITH SURFACE HIGH PRESSURE OFF THE SE COAST AND MEAN TROUGHING ACROSS THE CENTRAL AND SW STATES. WILL SEE A WEAK SURFACE FRONT PUSH SOUTH OF THE REGION WEDNESDAY AS A WAVE PASSES WELL TO THE NORTH AND HEIGHTS DIP A BIT. HOWEVER THIS BOUNDARY INITIALLY DRY WITH ONLY WEAK HIGH PRESSURE TO THE NW WHICH SHOULD DO LITTLE TO DETER VERY WARM TEMPS FOR MIDWEEK. FRONT LOOKS TO LIFT BACK NORTH THROUGH THE REGION THURSDAY AS STRONGER LOW PRESSURE PIVOTS TOWARD THE UPPER MIDWEST. BAND OF DEEPER MOISTURE/LIFT MAY TEND TO SPILL DOWN THE BAROCLINIC ZONE FROM THE WEST SO BUMPED UP POPS STARTING THURSDAY MORNING...CONTINUING INTO THURSDAY EVENING WITH MOISTURE AROUND AND WEAK IMPULSES SLIDING BY. STRONGER COLD FRONT WITH THE WAVE TO THE WEST WILL APPROACH FRIDAY AND SHOULD PASS ACROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY PER THE FASTER EC. EXPECT PRE- FRONTAL BAND OF SHRA TO AFFECT MUCH OF THE REGION BY FRIDAY AFTERNOON WITH SOME ISOLATED TSRA POSSIBLE SOUTH AND SW SO RUNNING WITH CHANCE TO LOW LIKELY POPS INTO FRIDAY EVENING. BOUNDARY LOOKS TO GET FAR ENOUGH SE TO ALLOW DRYING ON SATURDAY WITH ONLY SOME EARLY CLOUDS/-SHRA MAINLY NW AND CLEARING ELSW PENDING LATER RUNS. GOOD SOUTH TO SW FLOW SHOULD FINALLY BRING TEMPS UP TO SPRING LEVELS AND ALLOW THEM TO STAY THERE WITH HIGHS MOSTLY 70S EXCEPT COOLING TO 60S SATURDAY BEHIND THE FRONT. LOWS WELL ABOVE FREEZING AND PERHAPS STAYING ABOVE 50 OUT EAST DURING MIDWEEK. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... AS OF 735 AM EDT SUNDAY... DEALING WITH RAIN AND SNOW SHOWERS ACROSS MOST OF THE TERMINALS THIS MORNING. ACROSS THE PIEDMONT INTENSITY LOOKS LIKE SO DO NOT EXPECT ANY VSBY ISSUES. IN THE WEST WHERE THERE WILL BE SNOW...BLOWING SNOW...VSBYS COULD DROP TO AROUND 1-2SM AT BLF/BCB AND PERHAPS LWB. WE WILL SEE THE AREA START TO DRY FROM THE SOUTHWEST TO THE NORTHEAST LATER THIS MORNING ESPECIALLY THIS AFTERNOON AS THE CLOSED LOW MOVES OFF THE MID ATLANTIC COAST. THE NORTHWEST WINDS ARE GOING TO BE THE BIGGER ISSUE WITH SOME GUSTS OVER 50 KNOTS IN THE HIGHER ELEVATIONS...BOONE NC FOR INSTANCE. BCB/ROA ARE IN THE BEST CORRIDOR AS FAR AS TAFS GO FOR WINDS CLOSE TO 50 KNOTS...WITH LESS IN THE WV MTNS AND LYH/DAN. WINDS WIL BE WEAKENING AFTER 00Z...AS HIGH PRESSURE BUILDS IN FROM THE WEST. EXTENDED AVIATION DISCUSSION... GENERALLY VFR CONDITIONS SUN NIGHT UNTIL THU OR FRI...WHEN A SLOW MOVING FRONTAL SYSTEM WILL REACH THE AREA FROM THE WEST/NORTH AND BRING INCREASING LIKELIHOOD OF MVFR CIGS...ESPECIALLY EASTERN WV. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...HIGH WIND WARNING UNTIL 10 PM EDT THIS EVENING FOR VAZ009- 012>020-022-032-033. WINTER WEATHER ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR VAZ018>020-024-035. WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR VAZ007-010-011- 023-024-034-035-043>047-058-059. NC...HIGH WIND WARNING UNTIL 10 PM EDT THIS EVENING FOR NCZ001>003- 018-019. WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR NCZ004>006-020. WV...WINTER WEATHER ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR WVZ042>045. WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR WVZ042>045. WINTER STORM WARNING UNTIL 4 PM EDT THIS AFTERNOON FOR WVZ042- 043-045. && $$ SYNOPSIS...NF/WP NEAR TERM...JH/WP SHORT TERM...RCS LONG TERM...JH AVIATION...MBS/RAB/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
555 AM CDT SUN MAR 30 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 319 AM CDT SUN MAR 30 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH SOUTH OF THE GULF OF ALASKA...A VIGOROUS SHORTWAVE TROUGH COMING INTO CENTRAL CALIFORNIA...AND A RIDGE AXIS FROM TEXAS INTO THE FORECAST AREA. PROFILER AND VAD WIND DATA SHOWED A CORRIDOR OF SOUTHWESTERLY 40-55 KT WINDS AT 925MB JUST TO THE WEST OF THE RIDGE AXIS. THESE WINDS ARE PROPELLING WARMER AIR THAT WAS OBSERVED OVER THE PLAINS YESTERDAY TOWARDS THE FORECAST AREA. ITS WORTH NOTING HIGHS YESTERDAY WERE IN THE 60S TO LOW 70S FROM WESTERN NORTH DAKOTA INTO OKLAHOMA...ASSOCIATED WITH 925MB TEMPS OF 10 TO 20C. CLOUD COVER MOSTLY OF THE SCATTERED CIRRUS VARIETY...REFLECTIVE OF UPPER LEVEL MOISTURE STREAMING FROM THE PACIFIC ON WATER VAPOR. AIRMASS ACROSS MUCH OF THE PLAINS AND THE FORECAST AREA VERY DRY PER 00Z SOUNDINGS...NOTED TOO FROM PRECIPITABLE WATER VALUES BETWEEN 0.2- 0.3 INCHES. AT THE SURFACE...THE SURFACE RIDGE THAT WAS OVER THE AREA YESTERDAY HAS SHIFTED EAST TO OVER LAKE MICHIGAN...WHILE PRESSURES ARE FALLING ALONG THE LEE OF THE ROCKIES. THE SURFACE RIDGE HAS PUSHED ANY MEANINGFUL SURFACE MOISTURE...DEWPOINTS AT OR ABOVE 40F...DOWN TO THE GULF OF MEXICO COAST. SYNOPTICALLY...THE UPPER RIDGING PRESENT OVER THE FORECAST AREA LOOKS TO PERSIST THROUGH TONIGHT...WITH A SHIFT TO THE EAST AFTER MIDNIGHT. THE PUSH EAST TO THE RIDGE IS CAUSED BY THE VIGOROUS SHORTWAVE LIFTING INTO THE FAR NORTHEAST COLORADO AREA BY 12Z MONDAY. ITS ALSO WORTH NOTING THAT THE SHORTWAVE BECOMES NEGATIVELY TILTED. WITH THE FORECAST AREA PROGGED TO BE IN THE WARM SECTOR OF A DEEPENING LOW COMING OUT OF COLORADO AND INTO CENTRAL NEBRASKA BY 12Z MONDAY...MUCH OF THE FORECAST CONCERN IS ON TEMPERATURES. 925MB TEMPS ARE PROGGED TO CONTINUE TO CLIMB THROUGH THE DAY ON A BREEZY SOUTH TO SOUTHWEST WIND...RISING FROM 1 TO 5C AT 12Z TO 9 TO 13C BY 00Z. THESE READINGS HOLD NEARLY STEADY FOR TONIGHT DUE TO PERSISTENT 25-35 KT SOUTH WINDS. COMBINATION OF THE AFOREMENTIONED WARM ADVECTION AND SUNSHINE SHOULD EASILY PUSH HIGHS INTO THE 60S ALONG AND SOUTHWEST OF I-94. NORTH OF I-94...SNOW PACK AND COOLER 925MB TEMPS WILL HOLD HIGHS BACK INTO THE 50S. THE MIXING TODAY TOO WILL BE LIMITED A LITTLE DUE TO SCT-BKN CIRRUS EMANATING FROM NEBRASKA AREA CURRENTLY. WITH A LOW LEVEL JET IN PLACE TONIGHT...MOST LOCATIONS SHOULD ONLY SEE LOWS IN THE 40S. THERE ARE INDICATIONS THE TYPICAL COLD SPOTS MIGHT DECOUPLE OR AT LEAST SEE LIGHTER WINDS...ALLOWING TEMPERATURES THERE TO DIP INTO THE UPPER 30S. PRECIPITATION-WISE...PLENTIFUL DRY AIR IN PLACE AS SEEN AT 00Z LAST EVENING WILL KEEP CONDITIONS DRY THROUGH THIS EVENING. AFTER MIDNIGHT...THERE IS GOOD AGREEMENT AMONG MODELS FOR A WARM CONVEYOR BELT OF PRECIPITATION TO DEVELOP OVER EASTERN NEBRASKA AND WESTERN IOWA. MUCH OF THIS PRECIPITATION CORRELATES WITH ISENTROPIC LIFT ON THE 305-310K SURFACES...OR AT PRESSURES ABOVE 700MB. IN ANY EVENT...AT LEAST THROUGH TONIGHT...THE FORECAST AREA STAYS DRY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 319 AM CDT SUN MAR 30 2014 MUCH OF THE FOCUS IS ON THE MONDAY THROUGH TUESDAY PERIOD. IMPACTS DESCRIBED BELOW... SYNOPTICALLY...ATTENTION IS COMPLETELY ON THE VIGOROUS SHORTWAVE TROUGH APPROACHING THE CENTRAL CALIFORNIA COAST. MODELS CONTINUE TO CONVERGE ON A COMMON SOLUTION FOR HANDLING THIS NEGATIVE TILT TROUGH...THOUGH THERE IS SOME SLIGHT TIMING SPREAD. MODEL CONSENSUS SHOWS THE TROUGH LIFTING INTO SOUTHWEST MN BY 00Z TUESDAY... NORTHWEST WI BY 12Z TUESDAY AND INTO ONTARIO BY 00Z WEDNESDAY. THE NAM REMAINS THE FASTEST OF THE CONSENSUS AND SEEMS A LITTLE SUSPICIOUS...SEEING THAT THE ECMWF HAS BEEN TRENDING SLOWER OVER THE PAST FEW DAYS. GIVEN THE VIGOROUS NATURE OF THE SHORTWAVE...WOULD SEEM A SLOWER AND DEEPER ROUTE WOULD BE THE WAY TO GO. REGARDING THE SURFACE LOW...FOLLOWING THE SAME PREMISES...BELIEVE THE SLOWER...DEEPER MORE WRAPPED SYSTEM PRESENTED BY THE CANADIAN/UKMET/ECMWF IS MORE LIKELY COMPARED TO THE NAM AND EVEN GFS. WPC HAS ALSO FAVORED THE SAME MODELS. PRECIPITATION-WISE...THE WARM CONVEYOR BELT DEVELOPING OFF TO OUR WEST LOOKS LIKELY TO MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA MONDAY MORNING. HARD TO SAY IF IT IS GOING TO PROGRESS INTO WISCONSIN PRIOR TO 18Z SEEING THE DRIER NAM/ECMWF LOOK. THEREFORE HAVE ONLY KEPT 20-40 PERCENT CHANCES 15-18Z. FOR THE AFTERNOON... THERE ARE SIGNS THAT THE WARM CONVEYOR PRECIPITATION MAY FALL APART AS IT MOVES INTO WISCONSIN...OR AT LEAST SHIFT NORTH INTO NORTHERN WISCONSIN....ESPECIALLY IN THE CANADIAN MODELS. GFS 305-310K ISENTROPIC LIFT PROGS SUGGEST THE SAME. THEREFORE...HAVE KEPT PRECIPITATION CHANCES MOSTLY IN THE 20-50 PERCENT RANGE OUTSIDE OF TAYLOR COUNTY WHERE PRECIPITATION IS MOST LIKELY. FOCUS THEN SHIFTS WEST ON WHETHER SHOWERS OR STORMS CAN FIRE ALONG A COLD FRONT / DRY LINE. THE GFS/CANADIAN/ECMWF/UKMET ALL INITIATE A SCT- BKN LINE OF SHOWERS NEAR I-35 TOWARDS 00Z. HOWEVER...THERE ARE TWO HUGE CONCERNS FOR THIS BEING A LINE OF SURFACE BASED CONVECTION... FIRST IS A FAIRLY STOUT CAP AROUND 700MB...SECOND ARE SURFACE DEWPOINTS WHICH MODELS TRY TO JUMP INTO THE LOW 50S. THE DEWPOINTS SEEM WAY OVERDONE. NOW CANT RULE OUT THE LINE OF SHOWERS FORMING MORE ABOVE THE CAP GIVEN FORCING FROM THE LEFT EXIT REGION ALONG WITH DPVA WITH THE TROUGH. SINCE THERE IS NO CAPE ABOVE THE CAP AND CONCERNED PRECIPITATION MAY NOT FORM AT ALL...REMOVED THE THUNDER CHANCE. THIS SHOULD ALSO REDUCE THE CONCERN OF ANY POSSIBLE SEVERE WEATHER. IF A LINE DOES FORM...IT LOOKS TO LIFT NORTHEAST THROUGH THE AREA DURING THE EVENING. PRECIPITATION LOOKS MORE LIKELY AFTER MIDNIGHT INTO TUESDAY MORNING OVER THE NORTHWEST HALF OF THE AREA AS THE COLD CONVEYOR BELT WRAPS IN. MOST OF THIS SHOULD BE A LIGHT SNOW WITH LITTLE ACCUMULATION. THIS SNOW WILL TAPER OFF TUESDAY AFTERNOON WITH THE DEPARTURE OF THE SYSTEM. TEMPERATURES...BEING IN THE WARM SECTOR ALL OF MONDAY WITH 9-13C 925MB READINGS...COMBINED WITH A WARMER START...THAT BREAK IN PRECIPITATION DURING THE AFTERNOON TO ALLOW FOR MIXING AND BREEZY SOUTH WINDS...HIGHS AGAIN SHOULD CLIMB INTO THE 60S AT MOST LOCATIONS. SNOWPACK HOLDS TAYLOR DOWN INTO THE 50S. READINGS THEN TANK MONDAY NIGHT AS THE COLD AIR WRAPS IN SOUTHWEST TO NORTHEAST. MUCH COOLER HIGHS FOR TUESDAY...THOUGH SOUTHERN AREAS SHOULD CLIMB INTO THE MID 40S AS THE COLD AIR DEPARTS. WINDS...SOUTHERLY 925MB WINDS INCREASE THROUGH MONDAY AS THE NEGATIVE TILT SHORTWAVE TROUGH APPROACHES. BY 21Z...MOST MODELS PROG THEM AROUND 40 KT WHILE 850MB WINDS APPROACH 50-55 KT...STRONGEST SOUTH OF I-90. DAYTIME MIXING SHOULD BE ENOUGH TO GIVE GUSTS OF 30- 35 KT...WITH A PRESSURE FALL CROSSING EAU CLAIRE GIVING SOME ISALLOBARIC HELP. AN ADVISORY MAY BE NEEDED IF NAM/GFS MOMENTUM TRANSFER PROGS ARE CORRECT...SUGGESTING 35-42 KT GUSTS. WITH THE COLD SIDE OF THE SYSTEM...925MB WINDS ARE A LITTLE LESS...CLOSER TO 35 KT FOR MONDAY NIGHT INTO TUE MORNING. THESE SHOULD EASILY MIX TO THE GROUND. MORE UNCERTAINTY EXISTS ON THE NEED FOR THE ADVISORY ON THE COLD SIDE. FOR TUESDAY NIGHT AND BEYOND... NEXT ITEM OF INTEREST IS THE TROUGH CURRENTLY SOUTH OF THE GULF OF ALASKA WHICH IS PROGGED TO END UP IN THE SOUTHWESTERN U.S. ON WEDNESDAY. UPPER RIDGING BUILDS DOWNSTREAM AHEAD OF THE TROUGH...BUT MOSTLY SOUTH OF THE FORECAST AREA. THIS KEEPS A COLDER LOW LEVEL AIRMASS IN PLACE. MEANWHILE...ISENTROPIC LIFT OF GULF OF MEXICO MOISTURE DOWNSTREAM OF THE UPPER TROUGH MAY SPREAD SOME PRECIPITATION INTO SOUTHERN PORTIONS OF THE FORECAST AREA PER 30.00Z GFS/GFS ENSEMBLES WEDNESDAY AND WEDNESDAY NIGHT. HOWEVER...30.00Z CANADIAN AND ECMWF KEEP THE PRECIPITATION SOUTH OF THE FORECAST AREA. HAVE SPLIT THE DIFFERENCE WHICH RESULTS IN MAINLY A DRY FORECAST NORTH OF I-90 TO SOME 20-50 PERCENT CHANCES SOUTH. THURSDAY COULD END UP BEING A MOSTLY DRY DAY. CONFIDENCE IS BEGINNING TO INCREASE FOR PRECIPITATION THURSDAY NIGHT THROUGH FRIDAY. THIS IS WHEN MODELS ARE IN GOOD AGREEMENT LIFTING THE TROUGH INTO THE FORECAST AREA. WINTER WEATHER ADVISORIES REMAIN POSSIBLE...MOSTLY DUE TO ACCUMULATING SNOW. DRIER WEATHER LOOKS TO MOVE IN FOR SATURDAY AS THE SYSTEM DEPARTS. BELOW NORMAL TEMPERATURES ARE LIKELY FOR MUCH OF TUESDAY NIGHT AND BEYOND GIVEN THE UPPER FLOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 555 AM CDT SUN MAR 30 2014 LOW LEVEL WIND SHEAR WILL OCCUR AT KRST THROUGH 15Z THIS MORNING WITH SURFACE WINDS OUT OF THE SOUTH AT 16KTS...VEERING SOUTH/SOUTHWEST INCREASING INTO THE 50 TO 55 KT RANGE AT 1500 FT. LLWS WILL SUBSIDE LATER THIS MORNING. OTHERWISE PLAN ON BREEZY SOUTH WINDS AT THE TAF SITES TODAY WITH VFR CONDITIONS EXPECTED. SCT-BKN 25KFT CIRRUS WILL STREAM OVER THE REGION TODAY. PLAN ON VFR CONDITIONS TONIGHT WITH CLOUDS GRADUALLY INCREASING LATE WITH CLOUD BASES LOWERING TO AROUND 15KFT EARLY MONDAY MORNING. ISOLATED SHOWERS ARE POSSIBLE AT THE TAF SITES AFTER 12Z MONDAY MORNING. && .HYDROLOGY... ISSUED AT 319 AM CDT SUN MAR 30 2014 BASED ON GAUGE READINGS ALONG THE KICKAPOO FOR THOSE THAT STILL HAVE FLOOD WARNINGS...CONFIDENCE IS DECREASING THAT THEY WILL MAKE IT TO FLOOD. READSTOWN HAS STARTED FALLING...WHEN IT SHOULD STILL BE RISING. IF TRENDS CONTINUE...THE WARNINGS MAY BE CANCELLED. FOCUS THEN SHIFTS TO THE BLACK...BUFFALO AND TREMPEALEAU RIVERS. THE WARM UP OCCURRING TODAY AND PERSISTING INTO MONDAY EVENING... FEATURING HIGHS IN THE 55-65 RANGE AND LOWS IN THE 38-48 RANGE ALONG WITH BREEZY SOUTH WINDS...WILL HELP RAPIDLY MELT THE SNOW PACK THAT IS IN PLACE ALONG AND NORTH OF HIGHWAY 10. THIS RUNOFF WILL MAKE FLOODING A POSSIBILITY DURING THE WEEK. ON A POSITIVE NOTE...THE PRECIPITATION FROM THE SYSTEM MOVING THROUGH THE AREA MONDAY AND MONDAY NIGHT CONTINUES TO LOOK LESS AND LESS. AT THIS POINT...RAIN DOES NOT APPEAR TO BE MUCH OF A FACTOR TO THE RIVERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...WETENKAMP HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1053 AM PDT SUN MAR 30 2014 .SYNOPSIS...ISOLATED SHOWERS ARE POSSIBLE OVER THE HILLS ON SUNDAY AFTERNOON. OTHERWISE SUNDAY WILL BE A DRY DAY UNDER PARTLY CLOUDY SKIES. A ROBUST COLD FRONT WILL SPREAD RAIN ACROSS THE REGION ON MONDAY...ALONG WITH GUSTY WINDS. SHOWERS AND POSSIBLE THUNDERSTORMS ARE FORECAST FROM MONDAY NIGHT THROUGH TUESDAY EVENING. SHOWERS MAY LINGER OVER THE SOUTHERN PART OF THE REGION INTO WEDNESDAY. RAINFALL LATER IN THE WEEK NOW APPEARS LESS LIKELY. && .DISCUSSION...AS OF 9:08 AM PDT SUNDAY...CURRENT FORECAST IS PRETTY MUCH ON TRACK. THERE WERE SOME ISOLATED SHOWERS BEFORE SUNRISE BUT THOSE HAVE ENDED FOR THE MOST PART. SKIES ARE PARTLY CLOUDY THIS MORNING IN THE WAKE OF YESTERDAYS FRONTAL PASSAGE AND ASSOCIATED RAINFALL. THERE WAS SOME DENSE FOG EARLIER IN THE SONOMA VALLEYS BUT THAT`S LIFTING AS WELL. THE 12Z KOAK SOUNDING IS SOMEWHAT UNSTABLE AND GIVEN CURRENT CUMULUS DEVELOPMENT EXPECT WE`LL SEE CLOUDS START TO BILLOW UP OVER THE HILLS FROM MIDDAY THROUGH AFTERNOON WITH COLDER AIR ALOFT. CURRENT FORECAST SHOWS SLIGHT CHANCE OF SHOWERS THIS AFTERNOON MAINLY OVER OUR EASTERN/INLAND HILLS AND THAT LOOKS LIKE A GOOD FORECAST. NAM AND HRRR MODELS SPIT OUT SOME LIGHT CONVECTIVE QPF NEAR MOUNT HAMILTON LATER THIS AFTERNOON AND THAT OFTEN OCCURS IN THESE TYPE OF PATTERNS. WILL KEEP THE KMUX-88D SPINNING IN VCP 12 FOR THE TIME BEING. OTHERWISE EXPECT A PARTLY CLOUDY AND PLEASANT SUNDAY AFTERNOON WITH HIGHS INTO THE LOW AND MID 60S. MAIN FORECAST FOCUS WILL BE ON MONDAYS COLD FRONT AND 12Z MODELS ARE STAYING CONSISTENT WITH LIGHT RAIN INTO THE NORTH BAY BEFORE NOON BUT THE MAIN RAIN BAND REALLY IMPACTING THE AFTERNOON AND EVENING COMMUTE. THE STORM IS LOOKING GOOD ON SATELLITE RIGHT NOW OUT NEAR 45N/140W WITH PLENTY OF COLD AIR AND IMPLIED JET ENERGY. SEE NO REASON TO CHANGE INHERITED FORECASTS AND NOT PLANNING MANY CHANGES FOR AFTERNOON PACKAGE. AFTER BRIEF PERIOD OF FRONTAL RAINS MONDAY AFTERNOON AND EVENING...EXPECT A SHORT LULL IN THE PRECIP. THEN SHOWERS AND T-STORMS SHOULD BECOME NUMEROUS LATER MONDAY NIGHT INTO TUESDAY AS COLD CORE APPROACHES. SHOWERS WILL LINGER INTO WEDS MORNING FOR THE MONTEREY BAY REGION. MARCH GOING OUT LIKE A LION. && .PREV DISCUSSION...AS OF 3:30 AM PDT SUNDAY...WIDELY SCATTERED SHOWERS CONTINUE ACROSS THE SOUTHERN HALF OF THE CWA EARLY THIS MORNING. RADAR INDICATES THESE SHOWERS ARE EITHER DISSIPATING OR MOVING TO THE SOUTHEAST OUT OF OUR AREA. THUS...IT LOOKS LIKELY THAT ALL RAIN WILL END BY DAYBREAK AS FORECAST BY THE MODELS. SKIES ARE CLEARING FROM NORTH TO SOUTH AND PATCHY FOG HAS FORMED IN THE NORTH BAY VALLEYS. THE LOW LEVELS PROBABLY ARE NOT YET STABLE ENOUGH TO SUPPORT FOG FORMATION OUTSIDE THE ISOLATED NORTH BAY VALLEY LOCATIONS THIS MORNING. CLOUDS SHOULD MOSTLY CLEAR BY DAYBREAK AND THE BALANCE OF THE DAY WILL BE PARTLY TO MOSTLY SUNNY. SOME CU BUILDUPS ARE LIKELY OVER THE HILLS IN THE AFTERNOON...AND ISOLATED SHOWERS ARE POSSIBLE OVER THE INLAND HILLS OF THE SF BAY AREA AS FORECAST BY BOTH THE NAM AND GFS. AFTERNOON HIGHS WILL MOSTLY BE AROUND 60...A BIT COOLER THAN NORMAL. EARLY MORNING SATELLITE IMAGERY SHOWS A COLD UPPER TROUGH IN THE NORTHEAST PACIFIC...CENTERED NEAR 45N/140W. THIS SYSTEM IS FORECAST TO DROP SOUTHEAST OVER THE NEXT FEW DAYS AND BRING PERIODS OF PRECIPITATION TO OUR REGION DURING THE FIRST HALF OF THE WORK WEEK...ALONG WITH COOL TEMPERATURES...GUSTY WINDS...POSSIBLE THUNDERSTORMS...AND SNOW ON THE HIGHER HILLS. THE LEADING EDGE OF THIS SYSTEM WILL BE A RELATIVELY STRONG COLD FRONT THAT WILL SPREAD RAIN ACROSS OUR AREA ON MONDAY AND MONDAY EVENING. BRIEF HEAVY RAIN COULD OCCUR AROUND THE TIME OF FRONTAL PASSAGE...MAINLY LATE MONDAY AFTERNOON AND EARLY MONDAY EVENING. LOCAL WIND GUSTS BETWEEN 30 AND 40 MPH ARE POSSIBLE ALONG THE FRONT. AFTER THE COLD FRONT MOVES THROUGH...A COLD UPPER LOW OFFSHORE WILL SLIDE GRADUALLY TO THE SOUTHEAST...EITHER TRACKING DIRECTLY ACROSS THE SF BAY AREA BY LATE TUESDAY AND TUESDAY NIGHT AS FORECAST BY MOST MODELS...OR TRACKING OFFSHORE PARALLEL TO THE COAST AS DEPICTED BY THE GFS. REGARDLESS OF THE LOW CENTER`S EXACT TRACK...THE INSTABILITY GENERATED BY THIS COLD SYSTEM WILL TRIGGER WIDESPREAD SHOWER ACTIVITY ACROSS OUR AREA FROM LATE MONDAY NIGHT THROUGH TUESDAY NIGHT. THUNDERSTORMS ARE ALSO POSSIBLE GIVEN THE EXPECTED STEEP LAPSE RATES AND GOOD LOW LEVEL SHEAR. SNOW LEVELS WILL DROP TO 4000 FEET BY LATE MONDAY AFTER COLD FRONTAL PASSAGE...AND THEN AS LOW AS 3500 FEET FROM MONDAY NIGHT THROUGH TUESDAY NIGHT AS AN UNSEASONABLY COOL AIRMASS SPREADS ACROSS OUR AREA. HEAVIER SHOWERS COULD BRIEFLY PRODUCE EVEN LOWER SNOW LEVELS ALONG WITH SMALL HAIL. THE LATEST MODELS KEEP SCATTERED SHOWER ACTIVITY GOING ACROSS THE SOUTHERN PART OF OUR AREA INTO WEDNESDAY. RAINFALL TOTALS FROM MONDAY THROUGH WEDNESDAY ARE CURRENTLY FORECAST TO RANGE FROM A HALF INCH TO AN INCH IN MOST AREAS...EXCEPT ONE TO TWO INCHES POSSIBLE IN THE COASTAL HILLS. SOMEWHAT LESSER RAIN TOTALS WOULD OCCUR IF THE LOW CENTER TRACKS OFFSHORE AS FORECAST BY THE GFS. SNOW ACCUMULATION IS LIKELY IN THE HILLS ABOVE 4000 FEET WITH A DUSTING OF SNOW POSSIBLE DOWN TO 3500 FEET. TEMPERATURES WILL BE UNSEASONABLY COOL FROM MONDAY THROUGH WEDNESDAY WITH HIGH TEMPERATURES EXPECTED TO BE MOSTLY IN THE 50S AND LOWER 60S...AND ONLY IN THE UPPER 30S AND 40S IN THE HILLS. A SPECIAL WEATHER STATEMENT WILL BE ISSUED SHORTLY TO SUMMARIZE THE EXPECTED WEATHER CONDITIONS DURING THE FIRST HALF OF THE WEEK...INCLUDING PERIODS OF BRIEF HEAVY RAIN...GUSTY WINDS...POSSIBLE THUNDERSTORMS...COOL TEMPS...AND SNOW IN THE HILLS. A SYSTEM DUE IN LATER IN THE WEEK IS LOOKING LESS IMPRESSIVE WITH EACH NEW MODEL RUN. THE GFS AND GEM MODELS BOTH WASH THIS SYSTEM OUT COMPLETELY AS IT APPROACHES THE COAST ON THURSDAY. THE ECMWF STILL BRINGS SOME PRECIP TO COASTAL AREAS LATE THURSDAY INTO FRIDAY...BUT EVEN THIS MODEL IS TRENDING DRIER. POPS HAVE BEEN REDUCED LATE IN THE WEEK...BUT MAY NEED TO BE REDUCED FURTHER GIVEN RECENT MODEL TRENDS. && .AVIATION...AS OF 10:45 AM PDT SUNDAY...A MOIST AIRMASS REMAINS IN PLACE ACROSS THE REGION AND WILL BRING ABOUT SCT/BKN CLOUDS THROUGH THIS EVENING. OVERALL...EXPECTING CIGS TO REMAIN ABOVE 3KFT...YET CANNOT RULE OUT CIGS BRIEFLY DROPPING TO MVFR LEVELS THIS AFTERNOON. WESTERLY WINDS INCREASE THIS AFTERNOON AND WILL CONTINUE THROUGH THE EARLY EVENING...THEN DIMINISH TONIGHT. CLOUDS INCREASE AND WINDS TURN SOUTHERLY AHEAD OF AN APPROACHING STORM SYSTEM MONDAY MORNING. VICINITY OF KSFO...GENERALLY VFR...CIGS SCT-BKN035 BY EARLY AFTERNOON WITH WEST WINDS INCREASING TO 12 TO 15KT. WINDS DIMINISH TONIGHT WITH A DECREASE IN CLOUD COVER. SOUTH WINDS DEVELOP EARLY MONDAY MORNING WITH LIGHT RAIN OR SHOWERS POSSIBLE BY MONDAY AFTERNOON. MODERATE TO HIGH CONFIDENCE. KSFO BRIDGE APPROACH...GENERALLY SIMILAR TO SFO...CIGS SLIGHTLY LOWER AT SCT-BKN025 THROUGH THE AFTERNOON. MONTEREY BAY AREA TERMINALS...GENERALLYVFR...CIGS SCT-BKN035 BY EARLY AFTERNOON. WEST WINDS WILL APPROACH 12 KT THIS AFTERNOON BEFORE DIMINISHING TONIGHT. WEAK SOUTHERLY FLOW DEVELOPS MONDAY MORNING. MODERATE TO HIGH CONFIDENCE. MODERATE CONFIDENCE. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...ROUGH BAR ADVISORY FOR SF BAR && $$ PUBLIC FORECAST: RWW AVIATION: RGASS VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
908 AM PDT SUN MAR 30 2014 .SYNOPSIS...ISOLATED SHOWERS ARE POSSIBLE OVER THE HILLS ON SUNDAY AFTERNOON. OTHERWISE SUNDAY WILL BE A DRY DAY UNDER PARTLY CLOUDY SKIES. A ROBUST COLD FRONT WILL SPREAD RAIN ACROSS THE REGION ON MONDAY...ALONG WITH GUSTY WINDS. SHOWERS AND POSSIBLE THUNDERSTORMS ARE FORECAST FROM MONDAY NIGHT THROUGH TUESDAY EVENING. SHOWERS MAY LINGER OVER THE SOUTHERN PART OF THE REGION INTO WEDNESDAY. RAINFALL LATER IN THE WEEK NOW APPEARS LESS LIKELY. && .DISCUSSION...AS OF 9:08 AM PDT SUNDAY...CURRENT FORECAST IS PRETTY MUCH ON TRACK. THERE WERE SOME ISOLATED SHOWERS BEFORE SUNRISE BUT THOSE HAVE ENDED FOR THE MOST PART. SKIES ARE PARTLY CLOUDY THIS MORNING IN THE WAKE OF YESTERDAYS FRONTAL PASSAGE AND ASSOCIATED RAINFALL. THERE WAS SOME DENSE FOG EARLIER IN THE SONOMA VALLEYS BUT THAT`S LIFTING AS WELL. THE 12Z KOAK SOUNDING IS SOMEWHAT UNSTABLE AND GIVEN CURRENT CUMULUS DEVELOPMENT EXPECT WE`LL SEE CLOUDS START TO BILLOW UP OVER THE HILLS FROM MIDDAY THROUGH AFTERNOON WITH COLDER AIR ALOFT. CURRENT FORECAST SHOWS SLIGHT CHANCE OF SHOWERS THIS AFTERNOON MAINLY OVER OUR EASTERN/INLAND HILLS AND THAT LOOKS LIKE A GOOD FORECAST. NAM AND HRRR MODELS SPIT OUT SOME LIGHT CONVECTIVE QPF NEAR MOUNT HAMILTON LATER THIS AFTERNOON AND THAT OFTEN OCCURS IN THESE TYPE OF PATTERNS. WILL KEEP THE KMUX-88D SPINNING IN VCP 12 FOR THE TIME BEING. OTHERWISE EXPECT A PARTLY CLOUDY AND PLEASANT SUNDAY AFTERNOON WITH HIGHS INTO THE LOW AND MID 60S. MAIN FORECAST FOCUS WILL BE ON MONDAYS COLD FRONT AND 12Z MODELS ARE STAYING CONSISTENT WITH LIGHT RAIN INTO THE NORTH BAY BEFORE NOON BUT THE MAIN RAIN BAND REALLY IMPACTING THE AFTERNOON AND EVENING COMMUTE. THE STORM IS LOOKING GOOD ON SATELLITE RIGHT NOW OUT NEAR 45N/140W WITH PLENTY OF COLD AIR AND IMPLIED JET ENERGY. SEE NO REASON TO CHANGE INHERITED FORECASTS AND NOT PLANNING MANY CHANGES FOR AFTERNOON PACKAGE. AFTER BRIEF PERIOD OF FRONTAL RAINS MONDAY AFTERNOON AND EVENING...EXPECT A SHORT LULL IN THE PRECIP. THEN SHOWERS AND T-STORMS SHOULD BECOME NUMEROUS LATER MONDAY NIGHT INTO TUESDAY AS COLD CORE APPROACHES. SHOWERS WILL LINGER INTO WEDS MORNING FOR THE MONTEREY BAY REGION. MARCH GOING OUT LIKE A LION. && .PREV DISCUSSION...AS OF 3:30 AM PDT SUNDAY...WIDELY SCATTERED SHOWERS CONTINUE ACROSS THE SOUTHERN HALF OF THE CWA EARLY THIS MORNING. RADAR INDICATES THESE SHOWERS ARE EITHER DISSIPATING OR MOVING TO THE SOUTHEAST OUT OF OUR AREA. THUS...IT LOOKS LIKELY THAT ALL RAIN WILL END BY DAYBREAK AS FORECAST BY THE MODELS. SKIES ARE CLEARING FROM NORTH TO SOUTH AND PATCHY FOG HAS FORMED IN THE NORTH BAY VALLEYS. THE LOW LEVELS PROBABLY ARE NOT YET STABLE ENOUGH TO SUPPORT FOG FORMATION OUTSIDE THE ISOLATED NORTH BAY VALLEY LOCATIONS THIS MORNING. CLOUDS SHOULD MOSTLY CLEAR BY DAYBREAK AND THE BALANCE OF THE DAY WILL BE PARTLY TO MOSTLY SUNNY. SOME CU BUILDUPS ARE LIKELY OVER THE HILLS IN THE AFTERNOON...AND ISOLATED SHOWERS ARE POSSIBLE OVER THE INLAND HILLS OF THE SF BAY AREA AS FORECAST BY BOTH THE NAM AND GFS. AFTERNOON HIGHS WILL MOSTLY BE AROUND 60...A BIT COOLER THAN NORMAL. EARLY MORNING SATELLITE IMAGERY SHOWS A COLD UPPER TROUGH IN THE NORTHEAST PACIFIC...CENTERED NEAR 45N/140W. THIS SYSTEM IS FORECAST TO DROP SOUTHEAST OVER THE NEXT FEW DAYS AND BRING PERIODS OF PRECIPITATION TO OUR REGION DURING THE FIRST HALF OF THE WORK WEEK...ALONG WITH COOL TEMPERATURES...GUSTY WINDS...POSSIBLE THUNDERSTORMS...AND SNOW ON THE HIGHER HILLS. THE LEADING EDGE OF THIS SYSTEM WILL BE A RELATIVELY STRONG COLD FRONT THAT WILL SPREAD RAIN ACROSS OUR AREA ON MONDAY AND MONDAY EVENING. BRIEF HEAVY RAIN COULD OCCUR AROUND THE TIME OF FRONTAL PASSAGE...MAINLY LATE MONDAY AFTERNOON AND EARLY MONDAY EVENING. LOCAL WIND GUSTS BETWEEN 30 AND 40 MPH ARE POSSIBLE ALONG THE FRONT. AFTER THE COLD FRONT MOVES THROUGH...A COLD UPPER LOW OFFSHORE WILL SLIDE GRADUALLY TO THE SOUTHEAST...EITHER TRACKING DIRECTLY ACROSS THE SF BAY AREA BY LATE TUESDAY AND TUESDAY NIGHT AS FORECAST BY MOST MODELS...OR TRACKING OFFSHORE PARALLEL TO THE COAST AS DEPICTED BY THE GFS. REGARDLESS OF THE LOW CENTER`S EXACT TRACK...THE INSTABILITY GENERATED BY THIS COLD SYSTEM WILL TRIGGER WIDESPREAD SHOWER ACTIVITY ACROSS OUR AREA FROM LATE MONDAY NIGHT THROUGH TUESDAY NIGHT. THUNDERSTORMS ARE ALSO POSSIBLE GIVEN THE EXPECTED STEEP LAPSE RATES AND GOOD LOW LEVEL SHEAR. SNOW LEVELS WILL DROP TO 4000 FEET BY LATE MONDAY AFTER COLD FRONTAL PASSAGE...AND THEN AS LOW AS 3500 FEET FROM MONDAY NIGHT THROUGH TUESDAY NIGHT AS AN UNSEASONABLY COOL AIRMASS SPREADS ACROSS OUR AREA. HEAVIER SHOWERS COULD BRIEFLY PRODUCE EVEN LOWER SNOW LEVELS ALONG WITH SMALL HAIL. THE LATEST MODELS KEEP SCATTERED SHOWER ACTIVITY GOING ACROSS THE SOUTHERN PART OF OUR AREA INTO WEDNESDAY. RAINFALL TOTALS FROM MONDAY THROUGH WEDNESDAY ARE CURRENTLY FORECAST TO RANGE FROM A HALF INCH TO AN INCH IN MOST AREAS...EXCEPT ONE TO TWO INCHES POSSIBLE IN THE COASTAL HILLS. SOMEWHAT LESSER RAIN TOTALS WOULD OCCUR IF THE LOW CENTER TRACKS OFFSHORE AS FORECAST BY THE GFS. SNOW ACCUMULATION IS LIKELY IN THE HILLS ABOVE 4000 FEET WITH A DUSTING OF SNOW POSSIBLE DOWN TO 3500 FEET. TEMPERATURES WILL BE UNSEASONABLY COOL FROM MONDAY THROUGH WEDNESDAY WITH HIGH TEMPERATURES EXPECTED TO BE MOSTLY IN THE 50S AND LOWER 60S...AND ONLY IN THE UPPER 30S AND 40S IN THE HILLS. A SPECIAL WEATHER STATEMENT WILL BE ISSUED SHORTLY TO SUMMARIZE THE EXPECTED WEATHER CONDITIONS DURING THE FIRST HALF OF THE WEEK...INCLUDING PERIODS OF BRIEF HEAVY RAIN...GUSTY WINDS...POSSIBLE THUNDERSTORMS...COOL TEMPS...AND SNOW IN THE HILLS. A SYSTEM DUE IN LATER IN THE WEEK IS LOOKING LESS IMPRESSIVE WITH EACH NEW MODEL RUN. THE GFS AND GEM MODELS BOTH WASH THIS SYSTEM OUT COMPLETELY AS IT APPROACHES THE COAST ON THURSDAY. THE ECMWF STILL BRINGS SOME PRECIP TO COASTAL AREAS LATE THURSDAY INTO FRIDAY...BUT EVEN THIS MODEL IS TRENDING DRIER. POPS HAVE BEEN REDUCED LATE IN THE WEEK...BUT MAY NEED TO BE REDUCED FURTHER GIVEN RECENT MODEL TRENDS. && .AVIATION...AS OF 4:46 AM PDT SUNDAY...COOL UNSTABLE AIR IS FILTERING IN BEHIND A DEPARTING COLD FRONT THIS MORNING. SKIES WILL BECOME VFR TODAY AS SHOWER ACTIVITY TAPERS OFF. MOISTURE AND LINGERING INSTABILITY MAY RESULT IN ISOLATED THUNDERSTORMS OVER LOCAL RIDGE LINES LATE THIS MORNING INTO THE AFTERNOON HOURS. THESE THUNDERSTORMS SHOULD NOT IMPACT THE TERMINALS. VICINITY OF KSFO...VFR...WITH CUMULUS POPPING UP CREATING CIGS SCT-BKN035 BY MID MORNING. WEST WINDS WILL INCREASE TO 15 TO 20 KT THIS AFTERNOON. MODERATE TO HIGH CONFIDENCE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS WITH OCCASIONAL SHOWERS THIS MORNING WILL GIVE WAY TO VFR SCT-BKN035 BY MID TO LATE MORNING. WEST WINDS WILL REACH 10 TO 15 KT THIS AFTERNOON. MODERATE CONFIDENCE. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...ROUGH BAR ADVISORY FOR SF BAR && $$ PUBLIC FORECAST: RWW AVIATION: LARRY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1106 AM MDT SUN MAR 30 2014 .UPDATE... ISSUED AT 1057 AM MDT SUN MAR 30 2014 DENSE MID AND HIGH CLOUD COVER INHIBITING DEEPER MIXING SO FAR THIS MORNING WITH STRONG WINDS SLOW TO MATERIALIZE. HOWEVER...STILL EXPECT A PERIOD OF STRONGER WINDS TO DEVELOP THIS AFTERNOON. LATEST HRRR RUNS INDICATE DENSER CLOUD COVER WILL BE ERODING AND BREAKING UP AFTER 2 PM MDT THIS AFTERNOON...AND ONCE THIS BECOMES REALITY...DEEPER MIXING WILL QUICKLY DRIVE DOWN 50 PLUS KNOTS OF WIND ALOFT...WHICH MORNING SOUNDING AND PROFILERS ALL INDICATED. ONCE WINDS GET MOVING IN NORTHERN ARIZONA...THE BLOWING DUST UP INTO THE FOUR CORNERS WILL ALSO BE MOVING IN...SO NO CHANGES TO CURRENT WIND HIGHLIGHTS. WILL EVALUATE SNOW POTENTIAL LATER TODAY FOR ANY POSSIBLE EXPANSION OF WINTER HIGHLIGHTS TONIGHT. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 505 AM MDT SUN MAR 30 2014 03Z HAND ANALYSIS SHOWED THE COLD FRONT AND ASSOCIATED SURFACE LOW STRETCHED FROM THE PANHANDLE OF IDAHO TO THE CENTRAL NV/UT BORDER...THEN BACK ACROSS SOUTHERN CALIFORNIA. WATER VAPOR SHOWING THE NEXT UPSTREAM SYSTEM DIGGING INTO CENTRAL CALIFORNIA EARLY THIS MORNING WITH A DEVELOPING BAROCLINIC LEAF OVER THE WESTERN GREAT BASIN. WINDS BACKING MORE SOUTHERLY AND STRENGTHENING UNDER THIS FEATURE WHICH IS KEEPING THE FRONT WELL TO THE WEST. PACIFIC MOISTURE IS ALSO WRAPPING INTO THE SYSTEM AND MODELS ARE CONSISTENT IN KEEPING THE DEEPER MOISTURE PINNED TO THE FRONT. KGJT RAOB STILL SHOWED WELL BELOW PWAT AT .20. THIS MOISTURE IS WELL ELEVATED AND WITH A DEEP MIXED LAYER EXPECTED AHEAD OF THE APPROACHING FRONT AND SYSTEM THE INGREDIENTS ARE IN PLACE FOR A VERY WINDY DAY ACROSS THE REGION. INVERTED V PROFILES WILL ONLY ENHANCE WIND GUSTS TO THE SURFACE AS VIRGA AND LIGHT SHOWERS DEVELOP THROUGH THE LATE MORNING HOURS WITH VERY BROAD ASCENT IN PLACE. WINDS ATOP THE MIXED LAYER ARE STILL THE STRONGEST IN THE SOUTHWEST CWA...WHICH IS WHERE CLOUDS LOOK THE THINNEST. CURRENT ADVISORIES LOOK ON TRACK AS WINDS ARE EXPECTED TO GUST IN THE 45 TO 55 MPH RANGE TODAY. I DID ADD A BLOWING DUST ADVISORY FOR 4 CORNERS AREA WHERE LIMITED VISIBILITY WAS OBSERVED DURING THE LAST WIND EVENT. DO NOT EXPECT SIGNIFICANT PRECIPITATION TO BE A THREAT UNTIL THE FRONT ENTERS THE NORTHWEST CWA BY MID AFTERNOON. COMPRESSIONAL HEATING AHEAD OF THE FRONT SEEMS IMPLIED BY LOW LEVEL THERMAL RIDGE ACROSS THE CO/UT BORDER. CLOUDS/VIRGA MAY HAMPER FULL HEATING BUT DECIDED TO PUSH SOME TEMPERATURES UP TOWARD THE WARMER MET GUIDANCE NUMBERS. PRECIPITATION LOOKS TO BLOSSOM THROUGH THE LATE AFTERNOON AND EVENING AS THE FRONT WILL BE WORKING EASTWARD AND ASCENT FROM THE PASSING TROUGH MOVES OVERHEAD. INSTABILITY AND MOISTURE NEAR THE FRONT HAS THE BEST CHANCE FOR POPPING SOME THUNDERSTORMS IN THE NORTHWEST HIGH PLATEAUS...WITH A THREAT OF SEVERE GUSTS IN PART DUE TO STORM MOTIONS NEAR 50 MPH. CONSIDERED THIS AREAS FOR WIND ADVZY AS WELL BUT WITH THICKER CLOUD COVER THROUGH THE DAY CONFIDENCE STILL NOT THERE. GUSTY WINDS STILL EXPECTED BEHIND THE FRONT AS SUBSIDENCE FROM BEHIND THE QUICKLY MOVING TROF MOVES IN AND COLD ADVECTION ENHANCES MOMENTUM X-FER DOWNWARD. STRONG SOUTHWEST TO WEST THEN NORTHWEST FLOW INTO THE NORTHWEST MOUNTAINS WILL BE SUPPLEMENTED BY THE FRONTAL LIFTING/INSTABILITY/AND ASCENT THROUGH THE EVENING AND SNOW RATES WILL BE PICKING UP. SNOW WILL BE FAIRLY DENSE BUT BLOWING WILL BE LIKELY AS GUSTS OVER 40MPH CONTINUE THROUGH THE EARLY MORNING HOURS. THE WINTER HEADLINES LOOK ON TRACK AND THOUGH SNOW LEVEL REACH THE VALLEYS...AMOUNTS SHOULD BE IN THE 1-3 INCH RANGE. DRIER AIR AND SUBSIDENCE THROUGH THE NIGHT CLEARS ALL BUT THE NORTHERN DIVIDE MOUNTAINS WHERE OROGRAPHICS BECOME MORE FAVORABLE THROUGH MONDAY MORNING. COOLER TEMPERATURES WILL MOVE IN FOR MONDAY...BUT WINDS WILL BE SUBSIDING AS RIDGING TEMPORARILY BUILDS IN AHEAD OF THE NEXT TROF DEVELOPING TO THE WEST. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 505 AM MDT SUN MAR 30 2014 DIRTY SHORTWAVE RIDGE IN PLACE MONDAY NIGHT WITH PACIFIC MOISTURE AHEAD OF A STRONG PACIFIC STORM GENERATING SOME LIGHT OVERRUNNING ACROSS THE NORTH WHICH WILL INCREASE TUESDAY. TIGHTENING GRADIENT WILL BRING STRONG WINDS AGAIN TUESDAY AFTERNOON/EVENING. UNSETTLED CONDITIONS CONTINUE THROUGH MIDWEEK AS THE PACIFIC LOW SLOWLY DRIFTS ACROSS THE GREAT BASIN...THEN ACROSS THE FORECAST AREA. EXTENDED MODEL AGREEMENT NOT TERRIFIC WITH THIS SYSTEM SO KEPT POPS FAIRLY WIDESPREAD. THERE IS A CHANCE FOR SOME MOUNTAIN SNOW HIGHLIGHTS DURING THIS PERIOD...BUT GIVEN MODEL SPREAD HARD TO SPECIFY WHERE AND WHEN. LOTS OF SPREAD IN THE GFS ENSEMBLES AT THE END OF THE WEEK AND THE OPERATIONAL GFS AND ECMWF NOT IN VERY GOOD AGREEMENT. EC POINTS TO A DRIER FRIDAY BENEATH A SHORTWAVE RIDGE WHILE GFS INDICATED A WEAK SHORTWAVE TO KEEP CONDITIONS UNSETTLED. BY SATURDAY...BOTH SOLUTIONS INDICATED ANOTHER MODERATELY DEEP TROUGH WILL SETTLE OVER THE AREA FOR CONTINUED ACTIVE SPRING WEATHER. EXPECT COOLER THAN NORMAL TEMPERATURES THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1057 AM MDT SUN MAR 30 2014 GUSTY SOUTHWEST WINDS WILL CONTINUE TO STRENGTHEN THROUGH THIS AFTERNOON WITH PEAK SPEEDS EXCEEDING 50 KTS ACROSS THE VALLEYS WITH UP TO 60 KTS ACROSS THE HIGHER MOUNTAINS. THE STRONGEST WINDS WILL ARRIVE AROUND 21Z THIS AFTERNOON AS DENSE CLOUD COVER ERODES AND ALLOWS FOR DEEPER MIXING. AREAS OF BLOWING DUST WILL LOWER VISIBILITY INTO MVFR THRESHOLDS AT TIMES. RAIN AND SNOW DEVELOPS BY THIS EVENING AS WINDS GRADUALLY DIMINISH. MOUNTAIN PEAKS WILL BECOME OBSCURED AS SHOWERS INCREASE IN COVERAGE AND INTENSITY. CONDITIONS IMPROVE FROM WEST TO EAST AFTER 12Z MONDAY MORNING. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ003-006-007-009- 011-017>022. BLOWING DUST ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ021. WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM MDT MONDAY FOR COZ004-010-013. UT...WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR UTZ022-025-027>029. BLOWING DUST ADVISORY UNTIL 9 PM MDT THIS EVENING FOR UTZ022. && $$ UPDATE...JDC SHORT TERM...15 LONG TERM...NL AVIATION...JDC
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
401 PM EDT SUN MAR 30 2014 .SYNOPSIS... A LOW PRESSURE SYSTEM EAST OF NEW JERSEY WILL DRIFT SLOWLY OFFSHORE TONIGHT. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN FOR MONDAY NIGHT AND TUESDAY. ANOTHER LOW PRESSURE SYSTEM WILL TRACK THROUGH THE GREAT LAKES AND EASTERN CANADA WITH ITS ASSOCIATED COLD FRONT PASSING ACROSS THE AREA EARLY WEDNESDAY. THE FRONT IS THEN FORECAST TO STALL JUST SOUTH OF THE AREA THE REST OF THE WORK WEEK. ANOTHER LOW PRESSURE SYSTEM EMERGING FROM THE ROCKIES SHOULD THEN MOVE THROUGH THE GREAT LAKES ON SATURDAY WITH ITS COLD FRONT PASSING THROUGH THE REGION LATER THAT DAY. A HIGH PRESSURE SYSTEM SHOULD THEN START BUILDING EAST ON SUNDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... THE MID-LEVEL LOW LOCATED OVER SOUTHERN DELMARVA WILL CONTINUE TO DRIFT EASTWARD TONIGHT, WHILE THE SURFACE LOW LOCATED OFF THE NEW JERSEY COAST WILL DRIFT EASTWARD AS WELL. RAIN CONTINUES ACROSS MOST OF THE AREA LATE THIS AFTERNOON, AND WILL PERSIST THROUGH THE REMAINDER OF THE EVENING. THE MID-LEVEL LOW WILL SHIFT OFF THE NEW JERSEY COAST BY AROUND MIDNIGHT, AND CONTINUE TO MOVE FARTHER TO THE EAST TROUGH THE NIGHT. AS THE LOWS PULL AWAY, THE LOW-LEVEL FRONTOGENESIS AND STRONGEST LIFT WILL BEGIN TO WEAKEN ON THE WEST SIDE OF THE SYSTEM AND MOVE TO THE NORTHEAST, WHILE DRIER AIR BEGINS TO MOVE IN BY DAYBREAK. AS THIS HAPPENS, THE PRECIPITATION SHIELD SHOULD BEGIN DISSIPATING OVERNIGHT AS IT CONTINUES TO SLIDE EASTWARD. WE MAINTAIN THE WINTER WEATHER ADVISORY FOR CARBON/MONROE, PENNSYLVANIA OVERNIGHT, AS WE EXPECT A WINTRY MIX TO BEGIN AS COLDER AIR HAS BEGUN TO FILTER IN ON THE NORTHWEST SIDE OF THE SYSTEM. THE QUESTION IS HOW COLD WILL IT GET, AND HOW DEEP THE BELOW FREEZING LAYER WILL BE. THE GFS KEEPS A WARM LAYER ABOVE 925 MB THROUGH MUCH OF THE PERIOD, WHICH WOULD INDICATE MORE FREEZING RAIN/SLEET POTENTIAL. HOWEVER, THE NAM AND EVEN THE RUC SHOW THE POSSIBILITY OF THE ENTIRE LAYER DROPPING BELOW FREEZING, WHICH COULD LEAD TO MORE SNOW. THERE HAS BEEN SNOW REPORTED TO THE WEST, WHICH DOES GIVE SOME CREDENCE TO THE POTENTIAL FOR SNOW. WE WILL GO WITH A MIXED BAG OF PRECIPITATION OF SNOW, SLEET, FREEZING RAIN WHERE TEMPERATURES ARE EXPECTED TO DROP BELOW FREEZING IN THE ADVISORY AREA. WE BRING RAIN, SNOW, SLEET WHERE TEMPERATURES ARE EXPECTED TO REMAIN ABOVE FREEZING FOR THE NEXT TIER OF COUNTIES ACROSS PORTIONS EASTERN PENNSYLVANIA AND NORTHERN NEW JERSEY. HOWEVER, WE EXPECT ALL RAIN FROM THE PHILLY METRO/CENTRAL NEW JERSEY AREA SOUTHWARD. SNOW/SLEET ACCUMULATIONS ARE EXPECTED TO BE THE GREATEST ACROSS THE ADVISED AREA WHICH COULD BE AROUND 1-2 INCHES, ALONG WITH UP TO A TENTH OF AN INCH OF FREEZING RAIN. A BLEND OF MAV/MET MOS, MOS GUIDE, AND ECMWF WAS USED FOR OVERNIGHT LOWS. WINDS WILL BE BREEZY AT TIMES TONIGHT WITH GUSTS OF 25-30 MPH. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... N MONDAY, THE MID-LEVEL AND SURFACE LOWS WILL PULL OUT TO SEA, AND PRECIPITATION CHANCES WILL DIMINISH AFTER DAYBREAK. ALL PRECIPITATION CHANCES ARE EXPECTED TO BE OVER WITH BY MID-LATE MORNING. SKIES WILL CLEAR OUT THROUGH THE DAY, ALLOWING TEMPERATURES TO WARM CLOSE TO NORMAL. MONDAY WILL CONTINUE TO BE A BREEZY DAY, WITH GUSTS AT LEAST 25-30 MPH. A BLEND OF MAV/MET MOS, MOS GUIDE, AND ECMWF WAS USED FOR DAYTIME HIGHS. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... THE GFS INITIALIZATION LOOKED BETTER AT MOST LEVELS THAN THE WRF-NMMB. WHILE THEY ARE FAIRLY CLOSE AT THE START OF THE LONG TERM, THEY DO DEPART WITH WED`S SOLUTION WHERE WE WILL SIDE WITH THE HEMISPHERIC MODELS. THE LONG TERM HAS A VERY WELCOME TO APRIL LOOK TO IT WITH A STALLING FRONT AND NOT TOO MANY DRY DAYS. THE BIGGEST CHANGE FROM YESTERDAY IS A MORE ACTIVE FRONTAL BOUNDARY WHICH HAS ADDED WEDNESDAY TO THE WET MIXTURE. MONDAY NIGHT LOOKS TO BE THE BEST RADIATIONAL COOLING NIGHT OF THE WEEK AS HIGH PRESSURE PASSES ACROSS OUR CWA AND THE RIDGE AXIS IS STILL TO OUR WEST KEEPING SKIES GENERALLY CLEAR. MIN TEMPS SIDED TOWARD THE LOWER STAT GUIDANCE. ON TUESDAY THE MODELS ARE PASSING A SHORT WAVE THROUGH THE RIDGING. NET EFFECT WOULD BE SOME MID OR MORE LIKELY HIGH LEVEL CLOUDINESS DURING THE DAY. THE APPROACHING COLD FRONT IS STILL TOO FAR WEST TO TRIGGER ANY PCPN IN OUR CWA. THERE IS A NICE REBOUND AT 850MB WITH TEMPS, WITH 925MB TEMPS LAGGING. POTENTIAL FOR MID 60S FROM THE FALL LINE SEWD AWAY FROM THE COAST. GIVEN SOME CLOUDS, THE ONLY LOCATIONS WE WENT THAT HIGH WAS INLAND WITHIN DELMARVA. LOOKS LIKE A SEA BREEZE WILL DEVELOP SO, SOME UNCERTAINTY ABOUT IMMEDIATE COASTAL AREA HIGH TEMPS. OVERALL WE WERE HIGHER THAN STAT GUIDANCE. ON TUESDAY NIGHT, WHILE THERE WILL BE INSTABILITY ALOFT, MOISTURE BELOW 700MB IS FORECAST TO BE LACKING. THE LOW CHANCE FOR SHOWERS WAS RECONFIGURED MORE TOWARD THE WESTERN PART OF OUR CWA GIVEN THEY WOULD HAVE THE BEST CHANCE TO HAVE PCPN REACH THEM BEFORE DISSIPATING. MIN TEMPS, WEST ESPECIALLY, ABOVE STAT GUIDANCE BANKING ON MORE CLOUDS EARLY. WEDNESDAY HAS TAKEN A TURN FOR THE WETTER VS YESTERDAY`S MODEL RUNS. WITH THE FRONT SLOWING DOWN AND HIGH PRESSURE MORE GEOGRAPHICALLY DISPLACED, AN IMPULSE FROM THE ARKLATEX IS ABLE TO PASS ACROSS OUR CWA POSSIBLY PRODUCING SOME SHOWERS. THERE ARE STILL GEOGRAPHICAL (N VS S) AND SOME TIMING DIFFERENCES (WED DAY VS WED NGT), SO FOR NOW WE WERE RATHER GENERIC IN ADDING A CHANCE OF SHOWERS. WEDNESDAY NIGHT GOING WITH THE MAJORITY MODELING SOLUTION, WE HAVE A RELATIVELY LULL (LOWER) CHANCE FOR SHOWERS. CHANCES THEN INCREASE AGAIN THURSDAY AS A WARM FRONT APPROACHES OUR AREA PEAKING ON THURSDAY NIGHT SOUTH WITH LOWER POPS ON FRIDAY. TIMING CONFIDENCE IS LOW TO MODERATE. GIVEN THE FRONTAL BOUNDARY LOCATION MAX TEMP CONFIDENCE IN PARTICULAR IS LESS THAN AVERAGE. THE TIMING ON THE COLD FRONTAL INDUCED PCPN IS STILL CENTERED ON FRIDAY NIGHT WHEN OUR POPS INCREASE AGAIN. THE MODELS ARE SHOWING ENOUGH INSTABILITY FOR THUNDER, BUT WANT TO SEE MORE TIMING CONTINUITY BEFORE ADDING. THE MENTION OF POPS FOR SATURDAY IS A COMPROMISE BETWEEN THE SLOWER GFS/CAN GGEM AND ECMWF TIMING AS TO HOW QUICKLY WILL THE FRONT MOVE OFFSHORE. THEN MAYBE SUNDAY WE CAN FINALLY HAVE A DRY WEEKEND DAY, WELL AT LEAST WE WILL START OUR FORECAST FOR SUNDAY THAT WAY. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. SITES VARY FROM MVFR TO IFR LATE THIS AFTERNOON. WE EXPECT EVERYONE TO RETURN TO IFR FOR A PERIOD THIS EVENING AS PERIODS OF LIGHT TO MODERATE RAIN, WITH BRIEF PERIODS OF HEAVY RAIN CONTINUE TO AFFECT THE TAF SITES. AN IMPROVEMENT TO MVFR IS EXPECTED FOR THE TAF SITES OVERNIGHT, WITH AN EVENTUAL IMPROVEMENT TO VFR MONDAY MORNING. NORTHERLY WINDS WILL CONTINUE TO BE GUSTY THIS AFTERNOON AND BECOME MORE NORTHWESTERLY LATER THIS EVENING AND CONTINUE INTO MONDAY. WINDS COULD GUST 25-30 KNOTS AT TIMES TONIGHT INTO MONDAY. OUTLOOK... MON NIGHT THROUGH TUESDAY...VFR. HIGH CONFIDENCE. TUESDAY NIGHT AND WEDNESDAY...MVFR POSSIBLE AT TIMES AS A SLOWLY STALLING COLD FRONT WITH SHOWERS MOVES THROUGH THE REGION. WEDNESDAY NIGHT THROUGH FRIDAY...A FRONTAL BOUNDARY IS FORECAST TO STALL NEAR THE AREA WITH WAVES OF LOW PRESSURE ALONG IT. THIS WOULD GIVE US PERIODS OF MVFR TO IFR CONDITIONS, MOST LIKELY TIMES ARE THURSDAY NIGHT INTO FRIDAY. && .MARINE... A GALE WARNING HAS BEEN ISSUED FOR MOST OF THE ATLANTIC COASTAL WATERS AND DELAWARE BAY STARTING AT 8 PM TONIGHT. THE ONLY ZONE LEFT OUT OF THE GALE WARNING IS THE SANDY HOOD TO MANASQUAN ZONE AS CONFIDENCE ON GALE FORCE GUSTS ACROSS THE NORTHERN WATERS IS LOWER. 35-40 KNOTS WINDS ARE FORECAST AROUND 2,000 FEET THROUGH THE OVERNIGHT HOURS INTO THE MORNING HOURS MONDAY, AND ARE EXPECTED TO CREATE GALE FORCE GUSTS. THE WINDS WILL DROP BACK BELOW GALE FORCE MONDAY MORNING, BUT LIKELY REMAIN SMALL CRAFT ADVISORY LEVELS. SEAS WILL REMAIN ELEVATE THROUGH AT LEAST MONDAY. OUTLOOK... MONDAY NIGHT...SUB SCA CONDITIONS ON DELAWARE BAY. SEAS MIGHT STILL BE AT OR ABOVE SCA CRITERIA ON THE OCEAN. CHANCES DECREASE AS THE NIGHT PROGRESSES. TUESDAY THROUGH THURSDAY NIGHT...SUB SMALL CRAFT ADVISORY CONDITIONS EXPECTED WITH A RELATIVELY WEAK PRESSURE PATTERN. FRIDAY...THERE IS AN INCREASING CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS AS WE PROGRESS THROUGH FRIDAY AND NIGHT AS THE GRADIENT BETWEEN AN APPROACHING FRONT AND A HIGH PRESSURE SYSTEM OVER NEW ENGLAND TIGHTENS. && .HYDROLOGY... A FLOOD WARNING IS IN EFFECT FOR THE MILLSTONE RIVER AT BLACKWELLS MILLS AS THAT RIVER IS EXPECTED TO CONTINUE IT/S RISE TO A FOOT OR SO ABOVE FLOOD STAGE BEFORE CRESTING LATE TONIGHT. NEAR BANKFULL RISES ARE EXPECTED ON LOWER PORTIONS OF THE PASSAIC RIVER OVER THE NEXT 1 TO 2 DAYS, WITH MINOR FLOODING POSSIBLE. WE WILL CONTINUE TO MONITOR THE SITUATION AND FLOOD WARNINGS WILL BE ISSUED IF WARRANTED. MOST SMALLER STREAMS IN THE AREA HAVE RESPONDED WITH MODERATE RISES FROM THE 2 TO 3 INCHES OF RAIN THAT HAS FALLEN SINCE SATURDAY. BASED ON OBSERVED GAGE RESPONSE, IT APPEARS THIS RAIN HAS FULLY SATISFIED BASIN MOISTURE DEFICIENCIES SINCE EVERY AREA OF RAIN THAT NOW MOVES OVER THE SMALL WATERSHED BASINS INDUCES AN IMPRESSIVE RESPONSE AT THE ASSOCIATED GAGE. AN AREA OF IMPRESSIVE RAIN IN SOUTHERN NEW JERSEY WILL BE MOVING NORTHWEST INTO THE PHILA METRO AREA THROUGH THE EARLY EVENING HOURS. SOME OF THIS RAIN MAY BE HEAVY ENOUGH TO CAUSE URBAN AND SMALL STREAM FLOODING, AND ADVISORIES WILL BE ISSUED AS NECESSARY. THE FLOOD WATCH THEREFORE REMAINS IN EFFECT THROUGH 2 AM MONDAY. THE MAIN STEM DELAWARE RIVER, AS WELL AS THE LEHIGH AND SCHUYLKILL RIVERS, WILL EXPERIENCE RISES OVER THE NEXT DAY OR SO IN THE 2 TO 4 FOOT RANGE, BUT CREST LEVELS ARE EXPECTED TO REMAIN UNDER THREE-QUARTERS BANKFULL. THE LOWER SUSQUEHANNA RIVER WILL EXPERIENCE UP TO A THREE-QUARTER BANKFULL RISE OVER THE NEXT FEW DAYS, AND THIS RISE WILL THEN WORK ITS WAY DOWN TO THE SHORES OF BOTH CECIL AND HARFORD COUNTIES. RESIDENTS OF CECIL AND HARFORD COUNTY WILL SEE THIS RISE BY MID WEEK BUT ANY FLOODING THAT MIGHT OCCUR SHOULD BE CONFINED TO THE LOW-LYING AREAS NEAR THE RIVER. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH UNTIL 2 AM EDT MONDAY FOR PAZ054-055-060>062-070- 071-101>106. WINTER WEATHER ADVISORY UNTIL 8 AM EDT MONDAY FOR PAZ054-055. NJ...FLOOD WATCH UNTIL 2 AM EDT MONDAY FOR NJZ001-007>010-012-015. DE...FLOOD WATCH UNTIL 2 AM EDT MONDAY FOR DEZ001. MD...NONE. MARINE...GALE WARNING FROM 8 PM THIS EVENING TO 11 AM EDT MONDAY FOR ANZ430-431-451>455. SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ450. && $$ SYNOPSIS...GIGI/NIERENBERG NEAR TERM...ROBERTSON SHORT TERM...ROBERTSON LONG TERM...GIGI AVIATION...GIGI/NIERENBERG/ROBERTSON MARINE...GIGI/NIERENBERG/ROBERTSON HYDROLOGY...MIKETTA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
204 PM EDT Sun Mar 30 2014 .Near Term [Through Today]... The calming center of surface high pressure will slowly overspread the Southeast through the night tonight. There are a few complications regarding tonight`s minimum temperature forecast. For one, it is somewhat unclear whether winds will go completely calm, though they should be very light mostly everywhere by dawn. Additionally, just about every model is handling the upstream cirrus poorly. The HRRR has the best handle, but doesn`t run through the night. This forecast will essentially extrapolate the HRRR cirrus field eastward through the night. Due to the clouds and uncertain wind forecast, have trended up with overnight lows. Expect around 40 degrees to be common away from the coast (near 50 along the coast), with spotty locations reaching the upper 30s. The duration in the 30s, the clouds, and wind forecast would all argue a very hostile environment for frost to develop. IF frost were to occur under the current forecast conditions it would be extremely patchy, short lived, and confined to southeast Alabama. .Short Term [Tonight Through Tuesday]... An upper level ridge will be in place through this period as surface high pressure builds east of the area. This will be a dry pattern with no chance for rain and moderating temperatures. The lower humidity will also allow for a rather large diurnal swing in temperatures with chilly mornings and warm afternoons. Lows Monday night will be in the lower to mid 40s, while Tuesday night will only dip into the upper 40s to lower 50s. Highs will be in the upper 70s on Monday and reach the lower to mid 80s on Tuesday. .Long Term [Tuesday Night Through Sunday]... The period will start out dry and warm with the upper level ridge axis just east of the area and a surface high off the Southeast U.S. coast ridging westward along the Gulf Coast. Highs will be in the lower 80s for most areas on Wednesday and Thursday and mornings will be milder than earlier in the week. The upper ridge will be shunted eastward from Friday onward as energy over the Great Plains tries to make eastward progress. The associated frontal system will edge close enough to the region to tap into increasing Gulf moisture and produce scattered showers and thunderstorms each day from Friday through the weekend. Rain chances will be highest to the northwest and taper off to the southeast. Temperatures will remain above normal despite the increase in moisture. && .Aviation... [Through 18Z Monday] Breezy northwest winds will continue through the afternoon, with a calming trend occurring through the night, and light winds expected tomorrow. Other than a passing cirrus deck through the night, unlimited VFR is expected. && .Marine... High pressure to the west of the waters will move east of the area on Monday and then remain off the Southeast U.S. coast for several days. Offshore winds and seas have dropped below headline criteria this afternoon and this trend will continue tonight. Winds will veer around to onshore by Monday afternoon and light generally south to southeast winds will be the rule. A slight increase in winds speeds and seas is expected across the Florida Panhandle waters for Wednesday and Thursday. && .Fire Weather... Although relative humidities tomorrow will be quite low, and at time below critical levels, fuel moisture and/or duration criteria will not be met anywhere in the Tri-State region. Dispersions will be lower than recent days as high pressure moves overhead, calming winds a bit. Critical relative humidities are not anticipated Tuesday through the end of the week. && .Hydrology... Minor flooding is forecast to begin along the Choctawhatchee River at Caryville and Bruce early next week. Elsewhere, several other rivers in the CWA remain in action stage, but no flooding is forecast. The next chance for rain is on Friday. For the latest river stages and forecasts, please visit: water.weather.gov/ahps2/index.php?wfo=tae && .Preliminary Point Temps/PoPs... Tallahassee 39 78 41 84 47 / 0 0 0 0 0 Panama City 49 73 52 76 56 / 0 0 0 0 0 Dothan 42 77 46 81 52 / 0 0 0 0 0 Albany 39 77 45 83 50 / 0 0 0 0 0 Valdosta 40 80 43 84 48 / 0 0 0 0 0 Cross City 39 78 41 82 46 / 0 0 0 0 0 Apalachicola 48 71 49 75 54 / 0 0 0 0 0 && .TAE Watches/Warnings/Advisories... FL...High Rip Current Risk until 7 PM EDT this evening for Coastal Gulf. GA...None. AL...None. GM...None. && $$ NEAR TERM...HARRIGAN SHORT TERM...WOOL LONG TERM...WOOL AVIATION...HARRIGAN MARINE...WOOL FIRE WEATHER...HARRIGAN HYDROLOGY...BOLDEN
AREA FORECAST DISCUSSION
NWS GAYLORD MI
130 PM EDT SUN MAR 30 2014 .SYNOPSIS... ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH MONDAY...BRINGING PLENTY OF SUNSHINE AND INCREASINGLY WARMER TEMPERATURES. A FRONT CROSSING THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY WILL BRING A CHANCE FOR SOME LIGHT SHOWERS...ALONG WITH A RETURN TO COOLER WEATHER. RAIN MAY MIX WITH...OR EVEN CHANGE OVER...TO A BIT OF SNOW ON TUESDAY...BUT NO ACCUMULATIONS ARE EXPECTED. COOL WEATHER WILL CONTINUE FOR THE MIDDLE AND END PORTIONS OF THE WEEK...WITH ANOTHER CHANCE FOR A WINTRY MIX OF PRECIPITATION THURSDAY AND FRIDAY. && .UPDATE... ISSUED AT 1125 AM EDT SUN MAR 30 2014 HIGH PRESSURE SURFACE AND ALOFT WILL ENSURE A NICE AFTERNOON FOR NORTHERN MICHIGAN WITH JUST A FEW CLOUDS DRIFTING BY. WIDESPREAD HIGHS IN THE 40S EXPECTED. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 309 AM EDT SUN MAR 30 2014 HIGH IMPACT WEATHER POTENTIAL: NONE. PATTERN SUMMARY: AN EARLY MORNING LOOK AT THE PATTERN ACROSS THE CONUS REVEALS AN ACTIVE SETUP...WITH LOW PRESSURE SYSTEMS ALONG BOTH COASTS...AND A NARROW RIDGE OF HIGH PRESSURE IN BETWEEN THESE SYSTEMS... ARCHING FROM QUEBEC...THROUGH THE GREAT LAKES AND DOWN THE MISSISSIPPI VALLEY. THIS RIDGE AXIS CURRENTLY LIES JUST WEST OF THE FORECAST AREA...WITH A RIBBON OF CLEARING ALLOWING LOW TEMPERATURES TO FALL RAPIDLY AS BOUNDARY LAYER WINDS DECOUPLE. LOOKING FORWARD THROUGH THE SHORT TERM FORECASTS REQUIRES US TO LOOK UPSTREAM...AND...SOMEWHAT DIFFERENTLY THAN WE HAVE SEEN OF LATE...MUCH OF WHAT IS UPSTREAM IS DOMINATED BY PACIFIC...MARITIME POLAR AIR...WITH ANY ARCTIC AIR NOW BOTTLED UP NORTH OF THE REGION. THIS PACIFIC FLOW WILL RESULT IN LEE-SIDE CYCLOGENESIS EAST OF THE ROCKIES DURING THE DAY TODAY...WITH THIS LOW PRESSURE DEEPENING AND BEGINNING TO DEPART TO THE NORTH AND EAST BY THE END OF THIS PERIOD AROUND DAYBREAK MONDAY. THE DOWNSTREAM LONGWAVE TROUGH IS MUCH SLOWER MOVING...AND THE DEVELOPING SQUEEZE PLAY IN BETWEEN THESE FEATURES WILL FORCE HEIGHTS TO BUILD OVER THE GREAT LAKES WITH QUIET AND MODERATING CONDITIONS EXPECTED FOR NORTHERN MICHIGAN. CERTAINLY A WELCOME REPRIEVE FROM AN EXCEPTIONALLY COLD MONTH OF MARCH. THROUGH DAYBREAK: TEMPERATURES WILL CONTINUE TO TUMBLE THROUGH THE TEENS GIVEN CLEAR SKIES AND CALM-LIGHT WINDS. ALSO CAN/T RULE OUT SOME PATCHY GROUND FOG GIVEN IMPRESSIVE OVERNIGHT COOLDOWN. TODAY: RIDGE AXIS WILL BE PRETTY MUCH OVERHEAD TO START THE DAY...GRADUALLY SHIFTING EAST TO A POSITION OVER LAKE HURON TOWARDS EVENING. THERE/S A RELATIVE LACK OF MOISTURE THROUGH THE COLUMN TO START THE DAY WITH PWATS SUB 0.25" /A LITTLE BELOW SEASONAL NORMS FOR LATE MARCH/ WITH VALUES INCREASING DURING THE DAY AS A CHUNK OF PACIFIC MOISTURE /SEEN NOW AS A PLUME OF DEEP MOISTURE ACROSS THE NORTHWESTERN QUARTER OF THE COUNTRY/ RIDES EAST. WHILE THIS COULD MANIFEST ITSELF AS SOME HIGH CLOUDS FOR THE NORTHERN HALF OF THE CWA /ESP FOR THE SECOND HALF OF THE DAY/...THE LACK OF LLEVEL MOISTENING BENEATH BUILDING MID LEVEL HEIGHTS SUGGESTS NO REAL POTENTIAL FOR CU DEVELOPMENT. THUS...EXPECT ABUNDANT SUNSHINE FOR THE AREA WITH NO SENSIBLE WEATHER CONCERNS. TEMPERATURES /CONFIDENCE: HIGH/: TRAJECTORY ANALYSIS PLACES THIS AFTERNOON/S AIRMASS OVER SOUTHERN MINNESOTA 24 HOURS PREVIOUS WITH T9S SURGING TO 0-3C BY LATE AFTERNOON UNDER STRONG WARM ADVECTION. WITH BUILDING HEIGHTS AND NEARBY RIDGE AXIS...MIXING ISN/T GOING TO BE TOO STRONG. LOOKING BACK TO MINNESOTA...AREAS THAT WERE UNABLE TO MIX DEEPLY REACHED THE LOWER 40S...WITH UPPER 40S FURTHER WEST WHERE MECHANICAL MIXING COMBINED WITH WARMER TEMPS ALOFT TO BOOST SURFACE TEMPS. EXPECT THAT WE/LL BE CLOSER TO THE FORMER TODAY...AND EXPECT HIGHS IN THE 40-45 DEGREE RANGE. AMAZINGLY...THAT WILL PUT US JUST ABOUT WHERE WE SHOULD BE FOR THE END OF MARCH. AS MENTIONED BY THE PREVIOUS DAYSHIFT...LIGHT FLOW REGIME AND SOMEWHAT WARMER TEMPERATURES SHOULD ALLOW FOR SOME LAKE BREEZE DEVELOPMENT...KEEPING HIGHS LOCALLY COOLER ALONG THE LAKE HURON COAST. TONIGHT: RIDGE CONTINUES TO PUSH EAST OF THE GREAT LAKES REGION...WITH NORTHERN STREAM COLD FRONT STALLING NEAR LAKE SUPERIOR AS LOW PRESSURE ALONG THE EAST SLOPES OF THE ROCKIES BEGINS TO DEPART AND HEAD NORTHEAST. MOISTURE CONTINUES TO SLOWLY INCREASE...BUT PRIMARILY AT UPPER LEVELS WITH TOP-DOWN SATURATION LIKELY ONLY YIELDING AN INCREASE IN UPPER LEVEL CLOUDS THROUGH THE OVERNIGHT. GRADIENT STRENGTHENS THROUGH THE NIGHT...WITH MOST LOCATIONS RE-COUPLING DURING THE OVERNIGHT. SEE NO REPEAT OF ANY FOG GIVEN BETTER LLEVEL MIXING AND CONTINUED DRY LLEVEL CONDITIONS. TEMPERATURES /CONFIDENCE: MODERATE-HIGH/: TEMPERATURES WILL BE A LITTLE COMPLEX WITH EVENING MCLEAR SKIES AND DECOUPLING LIKELY TO GIVE WAY TO INCREASED MIXING AS THE NIGHT GOES ON. THIS WILL YIELD LOWS COLDEST OVER NORTHEAST LOWER WITH LOWS LIKELY TO DIP TO AROUND 20 /AND PERHAPS A TAD BELOW THIS/...WITH TEMPS OVER NORTHWEST LOWER STRUGGLING TO FALL MUCH BELOW THE FREEZING MARK. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 309 AM EDT SUN MAR 30 2014 ...REAL SPRING "WARMTH" GIVES WAY TO BELOW NORMAL TEMPERATURES (GO FIGURE)... HIGH IMPACT WEATHER POTENTIAL: WATCHING WINTRY PRECIP THREAT LATER IN THE WEEK. OVERVIEW: PATTERN REMAINS AN AGITATED ONE...WITH EXTENDED AMPED PACIFIC REGIME OVER THE CONUS TUCKED NICELY ON SOUTH SIDE OF WELL DEVELOPED NORTH CANADA COLD CORE GYRE. PACIFIC PATTERN CONTINUES TO WIN OUT OVER NORTHERN MICHIGAN...WITH STEADY RETREAT OF OVERHEAD COLD AIRMASS AS AGGRESSIVE UPSTREAM WARMING BEGINS. 00Z RAOB/HIGH RES RAP GUIDANCE CONFIRMS SUCH...SHOWING H8 TEMPERATURES SPIKING INTO THE TEENS (THAT`S ABOVE ZERO FOLKS!) ACROSS THE HIGH PLAINS...WITH ABOVE ZERO H8 AIR ALREADY ADVANCING TO THE MISSISSIPPI RIVER. EXPECTED RATHER SUBSTANTIAL UPPER MISSISSIPPI VALLEY LOW PRESSURE DEVELOPMENT EARLY THIS WORK WEEK WILL ONLY HELP THE NORTHERN LAKES WARMING CAUSE...WITH MUCH OF THE AREA TO FALL SQUARELY IN THE WARM SECTOR OF THIS SYSTEM AS IT TRACKS TO OUR NORTHWEST. UNFORTUNATELY...COOL AIR WILL BE FORCED SOUTH ON ITS BACKSIDE...ONCE AGAIN DROPPING TEMPERATURES TO BELOW NORMAL LEVELS AS WE HEAD THROUGH THE MID AND AND PORTIONS OF NEXT WEEK. PACIFIC WAVE TRAIN REMAINS...AT LEAST SETTING UP SOME POTENTIAL FOR BOUTS OF MORE WINTRY WEATHER HEADING INTO THURSDAY AND FRIDAY. OH...THE JOY! PRIMARY FORECAST CONCERNS/CHALLENGES: PLENTY! TEMPERATURE TRENDS THROUGHOUT...PRECIP TIMING/AND EVENTUAL TYPE...HEADING THROUGH NEXT WORK WEEK. DETAILS: JUST HOW WARM TO GO ON MONDAY? ABOUT TEXTBOOK END OF MARCH/BEGINNING OF APRIL SPRING STORM WILL BE UNDERGOING FULL DEVELOPMENT ACROSS THE CENTRAL PLAINS EARLY MONDAY...EXPECTED TO PASS SOMEWHERE VICINITY CENTRAL/WESTERN UPPER MICHIGAN TUESDAY. STRONG DOWNSTREAM OFF THE DECK WAA EXPECTED...WITH NOW MULTI-DAY PROGS SUPPORTING H8 READINGS SPIKING TO NEAR 10C BY LATER MONDAY OVER NORTHERN MICHIGAN. WITH ELEVATED WARM FRONT ALREADY NORTH OF THE AREA...AND CORE OF MID LEVEL DYNAMICS WELL OFF TO OUR WEST...WOULD EXPECT PLENTY OF SUNSHINE TO FURTHER KICK THE WARMING INTO OVERDRIVE. INCREASINGLY DEEP MIXED LAYER/FORCED MECHANICAL MIXING PER INCREASING WINDS SHOULD ALLOW SURFACE TEMPERATURES TO RESPOND ACCORDINGLY...AND REALLY LIKE INHERITED HIGHS WILL INTO THE 50S/NEAR 60 OVER NORTHERN LOWER MICHIGAN. SOUTHEAST LOW LEVEL FLOW WILL KEEP NORTHEAST LOWER AND EASTERN UPPER MICHIGAN SEVERAL DEGREES COOLER. MILD AIR CONTINUES INTO MONDAY NIGHT AS SOUTH FLOW REMAINS...AND FEEL SOME AREAS MAY FAIL TO FALL OUT OF THE 40S. DRY WEATHER GIVES WAY TO INCREASING SHOWER CHANCES MONDAY NIGHT AS OCCLUDED FRONT INTERACTS WITH NARROW BAND OF ENHANCED DEEP LAYER MOISTURE. STRONGEST AND DEEPEST DYNAMICS REMAIN TO OUR NORTHWEST...WHERE HEAVIEST AND STEADIEST PRECIPITATION SHALL RESIDE. BACK TO 2014 SPRING NORMALCY QUICKLY ON TUESDAY AS SURGE OF COLDER AIR FOLLOWS PASSAGE OF OCCLUDED FRONT. MORNING HIGH TEMPERATURES IN THE 30S AND 40S WILL SLOWLY FALL THROUGH THE AFTERNOON ON GUSTY SOUTHWEST TO WEST WINDS. LIGHT RAIN/SNOW SHOWERS TRANSITION TO MAINLY SNOW AS COLD AIR DEEPENS AND SYSTEM BACKSIDE MOISTURE REMAINS. JUST MINIMAL...IF ANY...ACCUMULATION IS EXPECTED. UNCERTAINTY THE NAME OF THE GAME HEADING INTO THE MID AND END PORTIONS OF THE WEEK. QUESTIONS ARE MANY CONCERNING NEXT WAVE EXPECTED TO EJECT OUT OF THE INTERMOUNTAIN WEST. INTERACTION BETWEEN SOUTHERN CANADA HIGH/ASSOCIATED DRY AIR FEED AND WHAT SHOULD BE RATHER VIGOROUS MID LEVEL WAVE LEADING TO RATHER SIGNIFICANT DISCREPANCIES AMONGST MID RANGE GUIDANCE. ECMWF REMAINS MOST ROCK-STEADY...SUGGESTING A MORE AMPED AND FURTHER NORTH SOLUTION WITH LOW PRESSURE MOVING DIRECTLY ACROSS THE GREAT LAKES TO END THE WORK WEEK. OTHER GUIDANCE STARTING TO FALL IN LINE WITH THIS MORE NORTH/AMPED SOLUTION...ALTHOUGH HONESTLY...THIS DOES LITTLE TO INCREASE CONFIDENCE AS A MORE SOUTH DISPLACED SYSTEM IS FULLY PLAUSIBLE GIVEN EXPECTED SET-UP AND POTENTIAL FOR A STRONGER CANADIAN HIGH. TEMPERATURE PROFILE REMAINS MARGINALLY SUPPORTIVE OF A MIXED PRECIP EVENT IF FURTHER NORTH SOLUTIONS VERIFY. SET-UP ALSO HAS SOME INTRIGUING FREEZING RAIN POSSIBILITIES...WITH POTENTIAL FOR MAINTENANCE OF DRY AND COLD EAST FLOW TO MAINTAIN SUB-FREEZING SURFACE TEMPERATURES...ALL THE WHILE ELEVATED WARM NOSE DEEPENS. OF COURSE...MUCH TOO FAR OUT TO SHOW SUCH SPECIFICS...ESPECIALLY CONSIDERING UNCERTAINTY IF SYSTEM WILL EVEN DIRECTLY AFFECT OUR AREA. LITTLE CHOICE BUT TO RUN WITH A GENERIC RAIN/SNOW CHANCE WORDING FOR NOW...WITH PLENTY OF TIME TO FINE-TUNE DETAILS IN COMING DAYS. WHILE EXCEPTIONALLY COLD AIR NOW LOOKS LIKE A THING OF THE PAST...OVERALL TRENDS FAVOR BELOW NORMAL TEMPERATURES WEDNESDAY THROUGH NEXT WEEKEND...WITH HIGHS MOSTLY IN THE 30S AND LOWER 40S/OVERNIGHT LOWS IN THE 20S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 130 PM EDT SUN MAR 30 2014 VFR CONDITIONS EXPECTED THROUGH MONDAY MORNING WITH MID AND HIGH LEVEL CLOUDINESS EXPECTED. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JPB SYNOPSIS...MSB SHORT TERM...ARNOTT LONG TERM...MSB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1237 PM CDT SUN MAR 30 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT SUN MAR 30 2014 ANOTHER WARM DRY SURGE OF AIR MOVES OFF THE CNTL ROCKIES TODAY. THE TEMPERATURE FORECAST FOLLOWS THE UPPER MIDDLE OF THE 13 MODEL SUPER ENSEMBLE FOR HIGHS IN THE 70S TO NEAR 80. A STATIONARY FRONT IS EXPECTED TO DEVELOP ALONG THE SD BORDER CAUSING WINDS TO BACK ACROSS THE NORTH KEEPING HIGHS NEAR 70. WE ALSO SEE A FAIRLY SOLID CIRRUS SHIELD DEVELOPING OFF THE LARAMIE AND FRONT RANGE LIMITING HEATING SOMEWHAT. SOUTH WINDS INCREASE TO 10 TO 20 MPH WITH GUSTS TO 25 MPH ACROSS MOST OF THE FCST AREA. FOR TONIGHT...SFC LOW PRESSURE WILL TRACK THROUGH THE CENTER OF THE FCST AREA AND WINDS BECOME NORTHWEST BEHIND THE SFC LOW ACROSS WRN NEB. ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING AND OVERNIGHT IN RESPONSE TO A LOW LEVEL JET AND COOLING/FALLING HEIGHTS ALOFT. THE NEW MODEL CONSENSUS BRINGS A SHARP 500 MB TROF INTO ERN WY AT 06Z WHICH CLOSES OFF ACROSS NW NEB BY 12Z. THERE ARE SIGNS OF THE HEIGHTS BACKING IN ALOFT ACROSS WRN SD AT THIS TIME WHICH IS TROUBLING SINCE THE LATEST ENSEMBLE SOLN IS TAKING THE UPPER LEVEL ENERGY ACROSS THE TETONS AND BIG HORN RANGES BUT THEN IT DROPPING SOUTH OF THE BLACK HILLS. THIS MORE SRN TRACK RAISES THE POP ACROSS NWRN NEB BETWEEN 06Z AND 12Z. THE NAM AND GEM REGIONAL THEN BRING THE RAIN SNOW LINE INTO NRN SHERIDAN COUNTY BETWEEN 09Z AND 12Z. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 359 AM CDT SUN MAR 30 2014 ATTENTION IN THE EXTENDED PERIODS CENTER ON PRECIPITATION CHANCES...MAINLY THE POTENTIAL OF TWO SIGNIFICANT LATE WINTER TYPE STORMS THAT MAY BRING ACCUMULATING SNOW TO PORTIONS OF THE CWA. THE FIRST SYSTEM WILL BE ONGOING ACROSS OUR NORTHERN ZONES BY 12Z MONDAY. LOW PRESSURE AND ASSOCIATED PV ANOMALY WILL CROSS FROM THE CENTRAL ROCKIES NORTHEAST OUT ONTO PLAINS...DRAGGING MODIFIED ARCTIC AIR SOUTH FROM CANADA ACROSS THE NORTHERN/CENTRAL PLAINS. MEDIUM RANGE MODELS HAVE GENERALLY COME INTO FAIR AGREEMENT WITH THE TRACK OF THE SURFACE CYCLONE...BUT INTENSITY/TIMING DIFFERENCES STILL EXIST. ATTM GENERALLY FAVOR THE GEM SOLUTION IN WHICH THE TRACK FAVORS STRONG FRONTOGENETIC FORCING MAINLY NORTH OF THE CWA. THAT BEING SAID...THERE/S STILL STRONG AGREEMENT THAT SNOW WILL WRAP AROUND THE LOW BACK ACROSS NORTHERN PORTIONS OF THE CWA. ATTM SNOW ACCUMULATIONS LOOK FAVORABLE FOR NORTHWESTERN NEBRASKA EARLY MONDAY...THEN TRANSITION EAST THROUGH THE DAY. THE PTYPE FORECAST IS STILL PROBLEMATIC. THE GEM SOLUTION IS WARMER WITHIN THE WARM SECTOR AS THE MODEL LIFTS THE LOW FURTHER NORTH THAN EAST...CHANGEOVER TO ALL SNOW MAY NOT OCCUR FOR OUR FAR EASTERN ZONES UNTIL MID-LATE AFTERNOON. WHERE THE CHANGE OVER DOES OCCUR EARLY...IMPACTS TO TRAVEL WOULD BE EXPECTED...ESPECIALLY GIVEN WIND GUSTS IN EXCESS 45 MPH. ATTM ALONG AND NORTH OF HIGHWAY 20 IN CHERRY AND SHERIDAN COUNTIES IS WHERE THE GREATEST CONFIDENCE IN SEEING THE EARLY CHANGEOVER AND ACCUMULATING SNOW. FOR THIS...WILL ISSUE A WINTER WEATHER ADVISORY WITH THIS FORECAST PACKAGE FOR THE TWO COUNTIES LISTED AS IMPACTS TO KVTN...RANCHING...HIGHWAY 20 AND THE POPULOUS CENTERED ALONG THE HIGHWAY ARE ANTICIPATED TO BE SIGNIFICANT. NOTE...IT COULD VERY WELL BE THAT SOUTHERN PORTIONS OF THESE TWO COUNTIES NOT SEE MUCH IF ANY ACCUMULATING SNOW WITH THIS SYSTEM WHILE THE FAR NORTH EXPERIENCES NEAR BLIZZARD CONDITIONS AND UP TO 4 INCHES OF SNOW. A HIGH END WIND ADVISORY IS ANTICIPATED MONDAY AS WELL ACROSS THE ENTIRE CWA. A STACKED PRESSURE GRADIENT WITH PRESSURE RISES ON THE ORDER OF UP TO 3 MB PER HOUR WILL LEAD TO NEAR HIGH WIND WARNING GUST CRITERIA. WILL LET THE DAY SHIFT FINE TUNE THE SPECIFICS. LASTLY...NEGATIVE LI/S ACROSS NORTH CENTRAL/NORTHERN NEBRASKA EARLY MONDAY WITH WEAK INSTABILITY ALOFT MAY YIELD A FEW EMBEDDED CONVECTIVE SHOWERS...WHETHER SNOW OR RAIN. NO MENTION OF THUNDER WAS INCLUDED BEYOND 12Z MONDAY...BUT MAY NEED TO BE LOOKED AT FURTHER. LOW AMPLITUDE TRANSITORY RIDGING BUILDS ATOP THE PLAINS ON TUESDAY WITH A RETURN TO AN ACTIVE PATTERN BY MIDWEEK. SOUTHWESTERLY FLOW IN THE UPPER LEVELS WILL PREVAIL AS THE NEXT LONGWAVE TROUGH OF INTEREST STARTS TO BUILD ACROSS THE DESERT SOUTHWEST WEDNESDAY. SLIGHT OPPORTUNITIES FOR QPF ALSO ARRIVE ON WEDNESDAY WITH THE APPROACH OF FAVORABLE UPPER LEVEL JET SUPPORT AND A SW DISTURBANCE. HOWEVER BETTER CHANCES ARRIVE LATE IN THE WEEK AS THE TROUGH EJECTS NORTHEAST FROM THE 4 CORNERS ONTO THE CENTRAL PLAINS. THERE REMAINS LARGE DISCREPANCIES ON HOW THE MODELS HANDLE THIS SYSTEM...WITH THE ECMWF NOW TAKING ON A NEGATIVE TILT AND A FAVORABLE TRACK OF THE H5 LOW FOR SNOW ACCUMULATION...POSSIBLY SIGNIFICANT ACROSS THE WEST CENTRAL SANDHILLS. THE GFS REMAINS OPEN AND PROGRESSIVE WITH FAR LESS IMPACTS. DUE TO THE MYRIAD OF WEATHER CURRENTLY GOING ON RIGHT NOW...FELT IT WAS BEST TO NOT VARY FROM A GENERAL MODEL BLEND WITH THIS LATE WEEK SYSTEM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1237 PM CDT SUN MAR 30 2014 HIGH CLOUDINESS /VFR CONDITIONS/ WILL STICK AROUND TODAY ACROSS ALL OF WESTERN NEBRASKA. ALTHOUGH A FEW ISOLATED THUNDERSTORMS ARE POSSIBLE THIS EVENING...MAINLY ACROSS FAR WESTERN NEBRASKA...THE MAIN THREATS WILL ARRIVE LATE TONIGHT IN THE FORMS OF WINTRY PRECIPITATION AND WIND. A STRONG COLD FRONT WILL SWITCH THE WINDS TO NORTHWEST AND INCREASE DRASTICALLY WITH GUSTS TO AT LEAST 30 KTS BY DAYBREAK. A RAIN/SNOW MIX IS LIKELY ACROSS NORTHERN NEBRASKA...INCLUDING KVTN...AFTER 31/09Z WITH A CHANGE TO ALL SNOW BY 31/14Z. DUE TO THE STRONG WINDS...ANY SNOW WILL EASILY REDUCE VISIBILITY TO IFR. FARTHER SOUTH...INCLUDING KLBF...THE CHANCE OF PRECIPITATION IS MUCH LOWER BUT THE WINDS WILL BE AS STRONG. && .FIRE WEATHER... ISSUED AT 359 AM CDT SUN MAR 30 2014 RED FLAG CONDITIONS ARE EXPECTED ACROSS THE ERN PANHANDLE...CENTRAL SANDHILLS...FRENCHMAN BASIN AND THE LOESS PLAINS. THE FORECAST IS A LOW END RED FLAG WARNING AS THE RAP SHOWS WINDS AT 700MB WEAKENING THIS AFTERNOON WHILE THE NAM ACTUALLY STRENGTHENS THEM. THE FORECAST FOLLOWS A BLEND OF THE GUIDANCE FROM THE RAP13...HRRR...NAMDNG AND AVN MOS MODELS FOR SOUTH WINDS OF 10 TO 20 MPH AND GUSTS TO 25 MPH. DEWPOINTS SHOULD FALL INTO THE TEENS...BUT ABOUT 5 DEGREES F HIGHER THAN SATURDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR NEZ204-206-210-219. WINTER WEATHER ADVISORY FROM 4 AM CDT /3 AM MDT/ TO 7 PM CDT /6 PM MDT/ MONDAY FOR NEZ004-005-094. && $$ SHORT TERM...CDC LONG TERM...JACOBS AVIATION...DS FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
326 PM CDT SUN MAR 30 2014 .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 325 PM CDT SUN MAR 30 2014 MAIN FORECAST CHALLENGE WILL BE THE STORM SYSTEM FOR LATER TONIGHT INTO EARLY TUESDAY. 12Z MODELS ARE IN MUCH BETTER AGREEMENT OVERALL WITH THIS SYSTEM WHICH INCREASES CONFIDENCE FOR THE WARNING PHASE. AS OF MID TO LATE AFTERNOON TEMPS HAD CLIMBED INTO THE MID TO UPPER 50S ACROSS THE SOUTHWEST FA BUT HAVE MAINTAINED THE MID 30S IN THE NORTHWEST. WINDS HAVE PRETTY MUCH SHIFTED TO A NORTHERLY DIRECTION NOW ACROSS ALL BUT THE FAR EASTERN FA. ALSO SEEING SFC DEW POINTS IN THE MID 30S ACROSS THE SOUTHERN FA WITH SOME 40S IN SOUTHWEST MN. SEEING CLOUD COVER THICKENING A BIT ACROSS THE AREA BUT STILL SOMEWHAT THIN ALLOWING SOME SUN THRU. THIS IS THE CALM BEFORE THE STORM. THICKER CLOUDS AND MORE SUBSTANTIAL ECHOES ARE SHOWING UP OVER EASTERN MT/WESTERN ND NOW. MODELS SLOWLY BRING SOME OF THIS NORTHEAST INTO MAINLY THE KDVL REGION LATER THIS EVENING. TEMPS WILL STAY MILD THIS EVENING AND EVEN AFTER MIDNIGHT...ESPECIALLY IN THE SOUTHERN AND EASTERN FA. THEREFORE AS THIS BAND OF PCPN EXPANDS ESPECIALLY AFTER MIDNIGHT PCPN TYPE COULD BECOME MORE OF AN ISSUE. THEREFORE THINKING SOME FORM OF MIXED PCPN MAY FALL LATE THIS EVENING INTO THE OVERNIGHT HOURS MAINLY ACROSS THE SOUTHERN AND EASTERN FA WHERE TEMPS ARE A LITTLE MILDER. NOT THINKING THIS WILL BE THE MAIN FORECAST ISSUE THOUGH...BUT WOULD DEFINITELY ADD TO THE PROBLEMS ASSOCIATED WITH THIS SYSTEM. THINKING THE SNOW WILL BEGIN TO GET HEAVIER AFTER MIDNIGHT ACROSS THE KDVL REGION INTO THE NORTHERN RED RIVER VALLEY. NORTHEAST WINDS WILL ALSO BEGIN TO CRANK UP BETWEEN 06Z AND 12Z FOR THIS AREA SO WILL GO AHEAD AND ISSUE A BLIZZARD WARNING FOR THIS AREA REPLACING THE BLIZZARD WATCH. AS THE SNOW BAND MOVES INTO NORTHWEST MN EAST OF THE VALLEY WINDS SHOULD NOT BE AS BIG OF A PROBLEM. WILL ISSUE A WINTER STORM WARNING FOR THIS AREA. MAIN QUESTION WILL CONTINUE TO BE WARM TEMPS ACROSS SOUTHEAST ND INTO WEST CENTRAL MN. THIS WILL AFFECT SNOW TOTALS AND EXACTLY WHEN BLIZZARD CONDITIONS MAY GET UNDER WAY. THINK THERE IS STILL ENOUGH UNCERTAINTY FOR THIS AREA TO KEEP THE BLIZZARD WATCH GOING THERE. FOR THE FARGO MOORHEAD AREA CONDITIONS WILL PROBABLY DETERIORATE ON MONDAY MORNING. THEREFORE WENT WITH A BLIZZARD WARNING FOR THAT AREA STARTING AT 12Z MONDAY. THIS IS THE TYPE OF SYSTEM THOUGH THAT THERE COULD INITIALLY BE LARGE VARIATIONS IN CONDITIONS FROM ONE PORTION OF A COUNTY TO ANOTHER. BIGGEST QUESTION MARK IS WHAT TO DO WITH EASTERN OTTER TAIL AND WADENA COUNTIES. AFTER COORDINATING WITH ADJACENT OFFICES WENT WITH A WINTER WEATHER ADVISORY. AS FAR AS SNOW TOTALS THIS IS DEFINITELY A CHALLENGE. REALLY THIS IS FORECASTING A RECORD TYPE EVENT SO HARD TO USE MUCH PERSONAL EXPERIENCE. WENT WITH A BAND OF 20 OR SO INCHES FROM COOPERSTOWN TO KGFK TO THE LAKE OF THE WOODS. MOST UNCERTAINTY MAY BE ACROSS SOUTHEAST ND AND WEST CENTRAL MN. WITH MODELS TRENDING NORTHWARD THE PAST FEW RUNS AND SLIGHT SHIFT COULD MAKE A BIG DIFFERENCE. LEFT THE EXPIRATION TIME AT 12Z TUE ALTHOUGH THERE COULD STILL BE SOMETHING LEFT IN THE EASTERN FA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 325 PM CDT SUN MAR 30 2014 LEFT THE TUE AFTERNOON INTO WED TIME FRAME DRY. TEMPS WILL DEPEND ON SNOW AMOUNTS FROM THE MON/TUE STORM. WEDNESDAY NIGHT-SUNDAY...12Z MODELS ALL INDICATE A STRONG SYSTEM WILL PROPAGATE ACROSS THE CENTRAL CONUS AROUND FRIDAY. HOWEVER...THE MODELS DIFFER WITH EXACTLY HOW FAR NORTH THIS SYSTEM WILL TRACK. THE GEM AND ECMWF BRING HEAVY SNOW AND STRONG WINDS INTO AT LEAST THE SOUTHERN FA...WHILE THE GFS KEEPS ALL SENSIBLE WEATHER TO THE SOUTH. KEPT THE IDEA OF LOWER POPS ACROSS THE SOUTHERN FA FOR THIS SYSTEM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1244 PM CDT SUN MAR 30 2014 MVFR CIGS ARE DROPPING SOUTH ACROSS NORTHEAST NORTH DAKOTA BEHIND THE WEAK COLD FRONT THAT HAS SHIFTED WINDS FROM THE NORTH. ANTICIPATE THAT THESE LOWER CIGS WILL EVENTUALLY INVADE ALL TAF SITES...BUT NOT SURE EXACTLY WHEN. FOLLOWED THE LATEST RAP GUIDANCE FOR TIMING. CONDITIONS WILL QUICKLY DETERIORATE TO IFR/LIFR CONDITIONS MONDAY MORNING AS HEAVY SNOW AND STRONG WINDS BECOME POSSIBLE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR NDZ052-053. BLIZZARD WARNING FROM 1 AM MONDAY TO 7 AM CDT TUESDAY FOR NDZ006>008-014>016-024-026>030-038-054. BLIZZARD WARNING FROM 7 AM MONDAY TO 7 AM CDT TUESDAY FOR NDZ039- 049. MN...BLIZZARD WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR MNZ029. WINTER STORM WARNING FROM 7 AM MONDAY TO 7 AM CDT TUESDAY FOR MNZ015>017-022>024-027-028. BLIZZARD WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR MNZ030-040. BLIZZARD WARNING FROM 1 AM MONDAY TO 7 AM CDT TUESDAY FOR MNZ001- 004-007. WINTER STORM WARNING FROM 1 AM MONDAY TO 7 AM CDT TUESDAY FOR MNZ005-006-008-009-013-014. BLIZZARD WARNING FROM 7 AM MONDAY TO 7 AM CDT TUESDAY FOR MNZ002- 003. WINTER WEATHER ADVISORY FROM 7 PM MONDAY TO 7 AM CDT TUESDAY FOR MNZ031-032. && $$ SHORT TERM...GODON LONG TERM...GODON/TG AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1244 PM CDT SUN MAR 30 2014 .UPDATE... ISSUED AT 1244 PM CDT SUN MAR 30 2014 TEMPS HAVE JUMPED ABOVE FORECAST HIGHS IN A FEW SPOTS SO WILL INCREASE MAX TEMPS A BIT MORE FOR TODAY. NO OTHER CHANGES PLANNED FOR THIS UPDATE. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 410 AM CDT SUN MAR 30 2014 BOY...COMPLEX SYSTEM. MUCH CHAT WITH NEIGHBORING OFFICES AND WPC SNOW DESK. CONSENSUS FROM NATIONAL FOLKS AFTER SEEING 00Z EURO WAS TO GO WITH A GEM/EURO BLEND AND A FARTHER NORTHWEST TRACK OF HEAVY SNOW AXIS. ALL MODELS HAVE BEEN SHIFTING NORTHWEST WITH HVY SNOW AXIS PAST 24 HOUS AND 00Z RUNS OF GFS/NAM 06Z NAM THE SAME. ALSO A BIT SLOWER. THIS CREATES ISSUES WITH CURRENT WATCH HEADLINES ISSUED SATURDAY. FOR TODAY...LIGHT RAIN NORTHEAST OF GRAND FORKS WILL MOVE NORTHEAST OUT BY 12Z...COLD FRONT WILL DROP INTO NRN ND BY 12Z AND MOVE SOUTH. COLDER AIR WITH IT NOT TOO DRASTIC UNTIL A BIT LATER TODAY. SOUTHEASTERN ND WILL BE IN WARMER AIR AND WITH SOME SUN TODAY COULD BOOST WELL INTO THE 50S WHERE NRN ND STAYS IN THE MID 30S OR FALLS. WATER VAPOR SHOWS POWERFUL 500 MB SHORTWAVE MOVING INTO CENTRAL CALIFORNIA WITH LIGHTNING STRIKES NOTED EARLIER NR SAN FRANCISCO. SYSTEM WILL MOVE EAST AND SURFACE LOW WILL DEVELOP AND MOVE INTO NORTHERN NEBRASKA WITH UPPER WAVE IN WRN NEBRASKA/WYOMING 12Z MON. A STREAK OF PRECIPITATION WILL SPREAD EAST-NORTHEAST INTO CENTRAL-NORTHEASTERN ND TONIGHT IN THE FROM OF SNOW. LOW PRESSURE WILL DEEPEN AND TRACK NORTH-NORTHEAST TO NEAR SIOUX FALLS 18Z MON AND 500 MB LOW DEEPENS AS WELL IN THE CNTRL DAKOTAS...AND BY 00Z TUES SFC LOW NR WILMAR MN WITH UPPER LOW NORTHEASTERN SD. STRONG ISENTROPIC LIFT AND PLENTIFUL MOISTURE WILL ALLOW A DEF ZONE BAND OF SNOW TO FORM RAPIDLY MONDAY MORNING IN FAR NW MN INTO DVL REGION INTO SOUTHWESTERN ND AND THEN PIVOT SLOWLY SOUTH AND EAST THRU THE DAY. ALL MODELS KEEP FAR SOUTHEASTERN FCST IN WARMER AIR ALOFT....WITH GEM/EURO WARMEST KEEPING ANY PRECIP THERE IN FERGUS FALLS-WADENA-FAR S RICHLAND COUNTY AS MOSTLY LIQUID THRU MON AFTN. HEAVY SNOW AXIS AT TIME ROX-GFK-JMS. 925 MB WINDS INCREASE WITH EURO STILL THE WINDIEST WITH 50-60 KTS WITH GFS 45KTS OR SO. REGARDLESS ENOUGH WIND AND SNOW TO LIKELY CAUSE BLIZZARD CONDITIONS TO DEVELOP THRU THE DAY MONDAY IN NRN/CNTRL RRV SOUTHWESTWARD. STILL ENOUGH TIMING DIFFERENCES AND HOW MUCH SNOWFALL AND EVENT STILL MOSTLY 12Z MONDAY AND AFTERWARDS WILL STAY WITH WATCHES. BUT WITH PTYPE ISSUES AND TIMING DID ADJUST START TIMES. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 410 AM CDT SUN MAR 30 2014 SNOW BAND WILL SHIFT EAST SLOWLY THRU THE FCST AREA MONDAY ENDING IN THE FAR EAST TUESDAY MORNING. WPC WWD AND PREFERENCE FOR A BIT FARTHER NORTHWEST TRACK GIVES A WIDE 12-15 INCH BAND COOPERSTOWN- VALLEY CITY THROUGH FARGO-GRAND FORKS TO BAUDETTE-ROSEAU-BEMIDJI. A BIT LESS NORTH AND SOUTH OF THIS BAND. WITH SLOWER PROGRESSION DID EXTEND WATCH ENDING TIME TO 12Z TUESDAY. QUIETER TUESDAY AS HIGH MOVES IN. WEDNESDAY THROUGH SATURDAY NIGHT...00 UTC GFS/ECMWF ARE IN FAIR AGREEMENT BOTH SHOWING THE NEXT EASTERN PACIFIC SHORT-WAVE CRASH ONTO THE CENTRAL CA COAST WEDNESDAY MORNING AND THEN MOVE IT NORTHEASTWARD INTO CENTRAL IA BY FRIDAY AFTERNOON. THE ECMWF IS STRONGER AT THIS TIME WITH A CLOSED 500 HPA LOW...WHEREAS THE GFS MAINTAINS AN OPEN WAVE. AS A RESULT...THE ECMWF/S QPF IS MORE ROBUST WITH ITS PRECIP SHIELD EXTENDING INTO THE SOUTHERN FORECAST AREA ON FRIDAY. THE GFS KEEPS MOST PRECIP FARTHER SOUTH ACROSS EASTERN SD INTO SOUTHERN MN. REMOVED ALL BLEND PRECIP WED/WED NIGHT WITH SFC HIGH IN PLACE...BUT WILL EXTEND 20/30 POPS FROM SOUTH TO NORTH THURS/THURS NIGHT MAINLY ACROSS THE SOUTHERN FORECAST AREA. LINGERING PRECIP FRIDAY SHOULD GIVE WAY TO DRY CONDITIONS FOR THE FIRST HALF OF THE WEEKEND. TEMPERATURES THROUGH THE PERIOD WILL GRADUALLY INCREASE EACH DAY...BUT REMAIN BELOW EARLY APRIL NORMALS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1244 PM CDT SUN MAR 30 2014 MVFR CIGS ARE DROPPING SOUTH ACROSS NORTHEAST NORTH DAKOTA BEHIND THE WEAK COLD FRONT THAT HAS SHIFTED WINDS FROM THE NORTH. ANTICIPATE THAT THESE LOWER CIGS WILL EVENTUALLY INVADE ALL TAF SITES...BUT NOT SURE EXACTLY WHEN. FOLLOWED THE LATEST RAP GUIDANCE FOR TIMING. CONDITIONS WILL QUICKLY DETERIORATE TO IFR/LIFR CONDITIONS MONDAY MORNING AS HEAVY SNOW AND STRONG WINDS BECOME POSSIBLE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM MONDAY MORNING THROUGH TUESDAY MORNING FOR NDZ039-049-052-053. BLIZZARD WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR NDZ006>008-014>016-024-026>030-038-054. MN...BLIZZARD WATCH FROM MONDAY MORNING THROUGH TUESDAY MORNING FOR MNZ002-003-029. WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR MNZ022>024-027-028. BLIZZARD WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR MNZ030-040. BLIZZARD WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR MNZ001-004-007. WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR MNZ005-006-008-009-013>017. WINTER STORM WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR MNZ031-032. && $$ UPDATE...GODON SHORT TERM...RIDDLE LONG TERM...RIDDLE/ROGERS AVIATION...TG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
452 PM EDT SUN MAR 30 2014 .SYNOPSIS... A DEEPENING STORM ON THE NJ COAST MOVE VERY SLOWLY EAST OVERNIGHT. A RIDGE OF HIGH PRESSURE WILL SLIDE OVERHEAD ON MONDAY AND LEAD TO FAIR AND MILDER TEMPERATURES FOR THE FIRST HALF OF THE WEEK. UNSETTLED CONDITIONS ARE EXPECTED TO RETURN FOR THE SECOND HALF OF THE WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... 445PM UPDATE... RAPID CHANGES TAKING PLACE AS THE INTENSE MESOSCALE BAND OF PRECIP IS GENERATING JUST ENOUGH COLD AIR TO CREATE LOCALLY HEAVY SNOW. WEB CAMS AND REPORTS WARRANT THE ISSUANCE OF AN ADVISORY INTO THE EVENING AS CONDITIONS VARY WILDLY FROM NOTHING AT ALL HAPPENING OVER MOST OF CENTRAL AND WESTERN PA...TO HEAVY SNOW AND SLEET AND RAIN OVER ABOUT THE EASTERN 1/3 OR SO OF OUR FORECAST AREA. THE SLOW MOVING BAND OF RAIN-SNOW-SLEET WILL CONTINUE TO ONLY SLOWLY DRIFT OVER MY EASTERN ZONES. WHERE PRECIP RATES ARE INTENSE ENOUGH...SOME LOCALLY HEAVY SNOW IS BEING OBSERVED. STILL THINKING MOST OF THE SNOW SHOULD BE CONFINED TO GRASSY SURFACES...BUT THE ROADS WILL BE SLIPPERY AND SLUSHY IN THE MORE PERSISTENT HEAVY SNOW BANDS. FROM EARLIER... REGIONAL RADAR MOSAIC AT 19Z SHOWS AN EXTENSIVE...AND NEARLY STATIONARY BAND OF MODERATE TO HEAVY RAIN OVER THE SUSQ MAINSTEM /AND POINTS WEST TO INTERSTATE 81 ACROSS SCENT PENN/ THIS AREA OF PERSISTENT/HEAVY PRECIP IS OCCURRING AS A RESULT OF THE COMBINED EFFECTS OF A MODERATELY STRONG DEFORMATION BAND AND MID-LEVEL FGEN FORCING /ENHANCED BY A WELL-DEFINED SPOKE OF VORTICITY SPIRALING AROUND THE NWRN EDGE OF THE SLOW MOVING UPPER LOW CENTERED OVER THE DELMARVA PENINSULA/. FLOOD WATCH REMAINS IN EFFECT UNTIL 8 PM THIS EVENING FOR THE EASTERN HALF OF THE STATE WHILE THE LOCALIZED VERY HEAVY RAIN ACROSS PORTIONS OF SCENT PENN HAVE PROMPTED US TO UPGRADE OUR EARLIER FLOOD ADVISORY TO A FLOOD WARNING FOR ADAMS AND YORK COUNTIES...WITH THE YELLOW BREECHES CREEK AT CAMP HILL FORECAST TO EXCEED FS TONIGHT. DEEP LAYER CAA WILL HELP TO GRADUALLY MIX...THEN CHANGE THE RAIN OVER TO WET SNOW ACROSS EVEN THE SOUTHERN VALLEYS LATE THIS AFTERNOON AND EARLY THIS EVENING...WHILE A GRADUAL DECREASING TREND IN THE LIGHTER SNOW OCCURS ACROSS THE NRN AND WESTERN MTNS OF THE STATE. CANCELLED THE WINT WX ADVISORY FOR ALL BUT SULLIVAN COUNTY...WHICH STILL RUNS THROUGH 4 PM TODAY. THIS MAY NEED TO BE EXTENDED A FEW HOURS BASED ON THE LATEST 18Z RAP. 15Z/18Z RAP DOING AN EXCELLENT JOB SIMULATING THIS NEARLY STATIONARY/SLOWLY WWD DRIFTING BAND OF HEAVIER PRECIP SWIRLING AROUND THE 546 DAM UPPER LOW. THESE MODELS SHOW A TREND OF MAINTAINING THIS RATHER HIGH RAINFALL INTENSITY /AND RATE OF AT LEAST .3 TO .6 OF AN INCH PER HOUR/ BEFORE CHANGING IT TO A FEW TO SVRL HOUR PERIOD OF /WET/ SNOW EARLY THIS EVENING...THEN SLOWLY WEAKENING THE PRECIP RATES AND SLOWLY SHIFTING THE AREA EAST ACROSS THE LOWER SUSQ REGION AND ECENT MTNS TONIGHT. ADDITIONAL QPF /LIKELY BETWEEN 0.5-1.0 INCH OF ADDITIONAL RAIN AND MELTED WET SNOW ACROSS THE SCENT ZONES AND LOWER SUSQ REGION/ WILL GRADUALLY TREND LOWER...THEN DIMINISH QUICKLY AS YOU HEAD NW TWD THE I-99/RT 220 CORRIDOR. THIS WILL LEAD TO A RAIN/WET SNOW MIXTURE WITH LITTLE OR NO ACCUM AT ELEVATIONS AOB 1400 FT MSL. MAINLY RAIN /MDT TO HVY AT TIMES/ WILL PERSIST ACROSS THE LOWER SUSQ VALLEY THROUGH THE LATE AFTERNOON WITH BIG...SLOPPY WET SNOWFLAKES MIXING IN TO THE WEST OF I-83. TEMPS ALOFT REMAIN JUST WARM ENOUGH FOR ALL RAIN IN THE FAR SE INVOF KLNS. SOME OF THE HIGHER TERRAIN OF SCENT...AND ECENT PENN /MAINLY AOA 1400 FT MSL/ COULD START TO SEE A GROUND COVERING OF WET SNOW LATER THIS AFTERNOON AND EVENING AS A FEW ADDITIONAL SPOKES OF VORTICITY AND N/S PRECIP BANDS ROTATE WWD AROUND THE UPPER LOW. 2-DAY STORM TOTAL RAINFALL AND MELTED SNOW BY MIDNIGHT TONIGHT HAVE REACHED 4-5 INCHES OVER PORTIONS OF SCENT PENN /ADAMS AND YORK COUNTIES/...JUST WEST OF THE SUSQ RIVER...WHILE OTHER LOCATIONS THROUGHOUT EASTERN CENTRAL AND EASTERN SECTIONS OF THE CWA COME IN BETWEEN 1.5 AND 2.5 INCHES. WET SNOW WILL CONTINUE TO TAPER OFF IN THE WEST THROUGH THIS AFTERNOON AS THE CENTER OF THE UPPER LOW MOVES FARTHER TO THE EAST AND SIGNIFICANT LIFT EXITS WITH IT. THE OTHER INCREASINGLY NOTABLE ASPECT OF THE WEATHER WILL BE THE GUSTY 30-40 MPH WIND THAT WILL BE DEVELOPING IN THE STRENGTHENING LLVL PRESSURE GRADIENT JUST IN THE WAKE OF THIS CURRENT SYSTEM. && .SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/... RAIN AND WET SNOW WILL CONTINUE INTO THE NIGHT OVER THE FAR EAST...WITH MINOR ACCUMS OF A COATING TO ONE INCH /PERHAPS 2 INCHES ON THE RIDGES AOA 1600 FT MSL FROM SCHUYLKILL CTY...NORTH TO SULLIVAN CTY. HIGH PRESSURE RIDGE BUILDS IN BEHIND THE STORM FOR MONDAY. RESIDUAL MSTR WILL PROBABLY HOLD CLOUDS IN THE WRN MTS AT FIRST...BUT CLEARING SHOULD OCCUR EVERYWHERE THROUGH THE AFTERNOON. TEMPS SHOULD RECOVER VERY NICELY AS 8H TEMPS SHOOT BACK INTO THE MID SINGLE DIGITS ABOVE ZERO. AREAS WITH SNOW ON THE GROUND MAY HAVE A BIT OF A DELAY IN THE RECOVERY...BUT ALMOST- APRIL SUNSHINE SHOULD DO SOME GOOD MELTING. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE NORTHEAST MONDAY NIGHT INTO TUESDAY. A LARGE UPPER LEVEL LOW WILL MOVE THROUGH SOUTHERN CANADA/GREAT LAKES REGION TUESDAY EVENING. THIS SYSTEM CONTINUES TO BE MOISTURE STARVED SO PRECIPITATION IS LESS LIKELY. WEAK SOUTHWESTERLY FLOW COULD ALLOW FOR A SLIGHT CHANCE FOR PRECIPITATION ALONG THE SW MTNS...HOWEVER THIS IS LESS LIKELY CONSIDERING ANY LINGERING HIGH PRESSURE. A STATIONARY BOUNDARY BETWEEN THE SYSTEMS SHOULD LIE OVER THE REGION WEDNESDAY INTO EARLY THURSDAY. THIS COULD ALLOW...FOR PERIODS OF LIGHT SHOWERS. A WEAK RIDGE COULD STIFLE PRECIP EARLY THURSDAY. A DEEPENING UPPER LEVEL LOW WILL MOVE THROUGH THE MIDWEST THURSDAY NIGHT INTO FRIDAY...AND THROUGH THE REGION SATURDAY. THIS SYSTEM WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION. THERE IS STILL VARIATION ON POSITION AND TIMING...BUT RAIN SHOWERS ARE POSSIBLE AS EARLY AS THURSDAY AFTERNOON AS THE ASSOCIATED WARM FRONT NOSES INTO PENNSYLVANIA. THE COLD FRONT WILL MOVE THROUGH THE AREA DURING THE FIRST PART OF THE WEEKEND BRINGING MORE RAIN. INTO LATE SATURDAY. && .AVIATION /21Z SUNDAY THROUGH FRIDAY/... A COMPLEX AREA OF LOW PRESSURE OVER THE DELMARVA REGION THIS AFTERNOON WILL MOVE ONLY SLOWLY EAST THROUGH THE RES OF THE DAYLIGHT HOURS...KEEPING WEATHER UNSETTLED THROUGH MUCH OF THE TAF PERIOD. WIDESPREAD MVFR CIGS AND VISBYS /WITH AREAS OF IFR/ IN RAIN WET SNOW WILL PERSIST THROUGH THIS AFTERNOON...WITH IFR/LIFR CONDS MOST PREVALENT ACROSS THE WRN AND NWRN MTNS...JST AND BFD. AS THE DEEP SFC LOW REMAINS NEAR TO THE COAST...WINDS SUSTAINED BETWEEN 15-25 MPH WITH HIGHER GUSTS WILL BE PREVALENT AT ALL AIRFIELDS INTO TONIGHT. HIGH CONFIDENCE IN GUSTS AOB 25KTS BETWEEN 18Z TODAY AND 04Z MONDAY. OUTLOOK... MON...LOW CIGS RAIN/SNOW ENDING ERN SXNS EARLY BCMG VFR. MVFR/IFR CIGS WEST BCMG VFR. TUE...VFR WITH OCNL MVFR PSBL IN SCT SHRA ASSOCD WITH COLD FRONT. WED-THU...VFR/MVFR WITH CHC OF RAIN. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR ABOUT EASTERN THIRD OF CWA THROUGH THIS EVENING. THE CLOSED UPPER LOW IS EXPECTED TO CLOSE TRACK SLOWLY TO THE EAST AND OFF MID ATLC COAST LATE TODAY AND TONIGHT. THIS WILL PRODUCE A FEW MORE NWWD BANDS OF MDT TO HEAVY RAIN OVER SCENT AND EASTERN PENN TODAY. THE HIGHER AMOUNTS STILL LOOK TO BE FOCUSED ACROSS THE SCENT MTNS...LOWER SUSQ VALLEY AND ECENT MTNS...AS THE DEFORMATION ZONE TO THE N/W OF THE UPPER LOW CENTER MOVES TO THE EAST AS WELL. THE RAIN MAY NOT MOVE OUT ENTIRELY UNTIL MIDNIGHT OR LATER. THUS...THE WATCH MAY NEED TO BE EXTENDED TO COVER THE PERIOD OF RUNOFF. BUT HAVE NOT MADE THIS MOVE QUITE YET. LOCALIZED STORM TOTAL AMOUNTS OF UP TO 2 INCHES ARE LIKELY OVER THE EAST. THIS WILL CAUSE SIGNIFICANT RISES ON THE SMALL STREAMS AND SOME MAY BE RISING TO BANKFULL BEFORE NOON. MANY OF THE LARGER WATERWAYS MAY GET TO THEIR CAUTION STAGES...BUT THESE EFFECTS WOULD BE DELAYED FOR A PERIOD OR TWO. THE MAINSTEM RIVER IS ALREADY PROGGED TO REACH CAUTION STAGES AT MANY PLACES WITH CURRENT QPF IN THE HYDRO MODEL. MMEFS PROBS FOR EXCEDENCE MAY BE UNDERDONE IN THE SREF DATA...MAINLY DUE TO THE SHIFTING QPF AREAS/CENTERS AMONGST THE MEMBERS. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ028-036-037-041- 042-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ042- 051>053-056>059-063>066. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...DANGELO/LAMBERT LONG TERM...CERU/COLBERT AVIATION...LAMBERT/GARTNER HYDROLOGY...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
426 PM EDT SUN MAR 30 2014 .SYNOPSIS... A DEEPENING STORM WILL MOVE VERY SLOWLY EAST FROM THE VIRGINIA PIEDMONT TO THE SOUTHERN NEW JERSEY COAST BY SUNDAY EVENING. A RIDGE OF HIGH PRESSURE WILL SLIDE OVERHEAD ON MONDAY AND LEAD TO FAIR AND MILDER TEMPERATURES FOR THE FIRST HALF OF THE WEEK. UNSETTLED CONDITIONS ARE EXPECTED TO RETURN FOR THE SECOND HALF OF THE WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 330PM...A SLOW MOVING BAND OF RAIN-SNOW-SLEET CONTINUED TO ONLY SLOWLY DRIFT OVER MY EASTERN ZONES. MADE SOME FAST CHANGES TO THE WINTER WEATHER ADVISORY FOR SULLIVAN COUNTY TO EXTEND IT INTO THE EVENING. I ALSO INCLUDED A SLUSHY INCH OR SNOW POSSIBLE OVER THE LOWER SUSQ VALLEY WHERE A WINTRY MIX OF SLEET AND SNOW IS OCCURRING UNDER THE BAND. WHERE PRECIP RATES ARE HEAVY ENOUGH...SOME LOCALLY HEAVY SNOW IS BEING OBSERVED. STILL THINKING MOST OF THE SNOW SHOULD BE CONFINED TO GRASSY SURFACES...BUT THE ROADS COULD BECOME SLIPPERY AND SLUSHY IN THE MORE PERSISTENT HEAVY SNOW BANDS. FROM EARLIER... REGIONAL RADAR MOSAIC AT 19Z SHOWS AN EXTENSIVE...AND NEARLY STATIONARY BAND OF MODERATE TO HEAVY RAIN OVER THE SUSQ MAINSTEM /AND POINTS WEST TO INTERSTATE 81 ACROSS SCENT PENN/ THIS AREA OF PERSISTENT/HEAVY PRECIP IS OCCURRING AS A RESULT OF THE COMBINED EFFECTS OF A MODERATELY STRONG DEFORMATION BAND AND MID-LEVEL FGEN FORCING /ENHANCED BY A WELL-DEFINED SPOKE OF VORTICITY SPIRALING AROUND THE NWRN EDGE OF THE SLOW MOVING UPPER LOW CENTERED OVER THE DELMARVA PENINSULA/. FLOOD WATCH REMAINS IN EFFECT UNTIL 8 PM THIS EVENING FOR THE EASTERN HALF OF THE STATE WHILE THE LOCALIZED VERY HEAVY RAIN ACROSS PORTIONS OF SCENT PENN HAVE PROMPTED US TO UPGRADE OUR EARLIER FLOOD ADVISORY TO A FLOOD WARNING FOR ADAMS AND YORK COUNTIES...WITH THE YELLOW BREECHES CREEK AT CAMP HILL FORECAST TO EXCEED FS TONIGHT. DEEP LAYER CAA WILL HELP TO GRADUALLY MIX...THEN CHANGE THE RAIN OVER TO WET SNOW ACROSS EVEN THE SOUTHERN VALLEYS LATE THIS AFTERNOON AND EARLY THIS EVENING...WHILE A GRADUAL DECREASING TREND IN THE LIGHTER SNOW OCCURS ACROSS THE NRN AND WESTERN MTNS OF THE STATE. CANCELLED THE WINT WX ADVISORY FOR ALL BUT SULLIVAN COUNTY...WHICH STILL RUNS THROUGH 4 PM TODAY. THIS MAY NEED TO BE EXTENDED A FEW HOURS BASED ON THE LATEST 18Z RAP. 15Z/18Z RAP DOING AN EXCELLENT JOB SIMULATING THIS NEARLY STATIONARY/SLOWLY WWD DRIFTING BAND OF HEAVIER PRECIP SWIRLING AROUND THE 546 DAM UPPER LOW. THESE MODELS SHOW A TREND OF MAINTAINING THIS RATHER HIGH RAINFALL INTENSITY /AND RATE OF AT LEAST .3 TO .6 OF AN INCH PER HOUR/ BEFORE CHANGING IT TO A FEW TO SVRL HOUR PERIOD OF /WET/ SNOW EARLY THIS EVENING...THEN SLOWLY WEAKENING THE PRECIP RATES AND SLOWLY SHIFTING THE AREA EAST ACROSS THE LOWER SUSQ REGION AND ECENT MTNS TONIGHT. ADDITIONAL QPF /LIKELY BETWEEN 0.5-1.0 INCH OF ADDITIONAL RAIN AND MELTED WET SNOW ACROSS THE SCENT ZONES AND LOWER SUSQ REGION/ WILL GRADUALLY TREND LOWER...THEN DIMINISH QUICKLY AS YOU HEAD NW TWD THE I-99/RT 220 CORRIDOR. THIS WILL LEAD TO A RAIN/WET SNOW MIXTURE WITH LITTLE OR NO ACCUM AT ELEVATIONS AOB 1400 FT MSL. MAINLY RAIN /MDT TO HVY AT TIMES/ WILL PERSIST ACROSS THE LOWER SUSQ VALLEY THROUGH THE LATE AFTERNOON WITH BIG...SLOPPY WET SNOWFLAKES MIXING IN TO THE WEST OF I-83. TEMPS ALOFT REMAIN JUST WARM ENOUGH FOR ALL RAIN IN THE FAR SE INVOF KLNS. SOME OF THE HIGHER TERRAIN OF SCENT...AND ECENT PENN /MAINLY AOA 1400 FT MSL/ COULD START TO SEE A GROUND COVERING OF WET SNOW LATER THIS AFTERNOON AND EVENING AS A FEW ADDITIONAL SPOKES OF VORTICITY AND N/S PRECIP BANDS ROTATE WWD AROUND THE UPPER LOW. 2-DAY STORM TOTAL RAINFALL AND MELTED SNOW BY MIDNIGHT TONIGHT HAVE REACHED 4-5 INCHES OVER PORTIONS OF SCENT PENN /ADAMS AND YORK COUNTIES/...JUST WEST OF THE SUSQ RIVER...WHILE OTHER LOCATIONS THROUGHOUT EASTERN CENTRAL AND EASTERN SECTIONS OF THE CWA COME IN BETWEEN 1.5 AND 2.5 INCHES. WET SNOW WILL CONTINUE TO TAPER OFF IN THE WEST THROUGH THIS AFTERNOON AS THE CENTER OF THE UPPER LOW MOVES FARTHER TO THE EAST AND SIGNIFICANT LIFT EXITS WITH IT. THE OTHER INCREASINGLY NOTABLE ASPECT OF THE WEATHER WILL BE THE GUSTY 30-40 MPH WIND THAT WILL BE DEVELOPING IN THE STRENGTHENING LLVL PRESSURE GRADIENT JUST IN THE WAKE OF THIS CURRENT SYSTEM. && .SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/... RAIN AND WET SNOW WILL CONTINUE INTO THE NIGHT OVER THE FAR EAST...WITH MINOR ACCUMS OF A COATING TO ONE INCH /PERHAPS 2 INCHES ON THE RIDGES AOA 1600 FT MSL FROM SCHUYLKILL CTY...NORTH TO SULLIVAN CTY. HIGH PRESSURE RIDGE BUILDS IN BEHIND THE STORM FOR MONDAY. RESIDUAL MSTR WILL PROBABLY HOLD CLOUDS IN THE WRN MTS AT FIRST...BUT CLEARING SHOULD OCCUR EVERYWHERE THROUGH THE AFTERNOON. TEMPS SHOULD RECOVER VERY NICELY AS 8H TEMPS SHOOT BACK INTO THE MID SINGLE DIGITS ABOVE ZERO. AREAS WITH SNOW ON THE GROUND MAY HAVE A BIT OF A DELAY IN THE RECOVERY...BUT ALMOST- APRIL SUNSHINE SHOULD DO SOME GOOD MELTING. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE NORTHEAST MONDAY NIGHT INTO TUESDAY. A LARGE UPPER LEVEL LOW WILL MOVE THROUGH SOUTHERN CANADA/GREAT LAKES REGION TUESDAY EVENING. THIS SYSTEM CONTINUES TO BE MOISTURE STARVED SO PRECIPITATION IS LESS LIKELY. WEAK SOUTHWESTERLY FLOW COULD ALLOW FOR A SLIGHT CHANCE FOR PRECIPITATION ALONG THE SW MTNS...HOWEVER THIS IS LESS LIKELY CONSIDERING ANY LINGERING HIGH PRESSURE. A STATIONARY BOUNDARY BETWEEN THE SYSTEMS SHOULD LIE OVER THE REGION WEDNESDAY INTO EARLY THURSDAY. THIS COULD ALLOW...FOR PERIODS OF LIGHT SHOWERS. A WEAK RIDGE COULD STIFLE PREICIP EARLY THURSDAY. A DEEPENING UPPER LEVEL LOW WILL MOVE THROUGH THE MIDWEST THURSDAY NIGHT INTO FRIDAY...AND THROUGH THE REGION SATURDAY. THIS SYSTEM WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION. THERE IS STILL VARIATION ON POSITION AND TIMING...BUT RAIN SHOWERS ARE POSSIBLE AS EARLY AS THURSDAY AFTERNOON AS THE ASSOCIATED WARM FRONT NOSES INTO PENNSYLVANIA. THE COLD FRONT WILL MOVE THROUGH THE AREA DURING THE FIRST PART OF THE WEEKEND BRINGING MORE RAIN. INTO LATE SATURDAY. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... A COMPLEX AREA OF LOW PRESSURE OVER THE DELMARVA REGION THIS AFTERNOON WILL MOVE ONLY SLOWLY EAST THROUGH THE RES OF THE DAYLIGHT HOURS...KEEPING WEATHER UNSETTLED THROUGH MUCH OF THE TAF PERIOD. WIDESPREAD MVFR CIGS AND VISBYS /WITH AREAS OF IFR/ IN RAIN WET SNOW WILL PERSIST THROUGH THIS AFTERNOON...WITH IFR/LIFR CONDS MOST PREVALENT ACROSS THE WRN AND NWRN MTNS...JST AND BFD. AS THE DEEP SFC LOW REMAINS NEAR TO THE COAST...WINDS SUSTAINED BETWEEN 15-25 MPH WITH HIGHER GUSTS WILL BE PREVALENT AT ALL AIRFIELDS INTO TONIGHT. HIGH CONFIDENCE IN GUSTS AOB 25KTS BETWEEN 18Z TODAY AND 04Z MONDAY. OUTLOOK... MON...LOW CIGS RAIN/SNOW ENDING ERN SXNS EARLY BCMG VFR. MVFR/IFR CIGS WEST BCMG VFR. TUE...VFR WITH OCNL MVFR PSBL IN SCT SHRA ASSOCD WITH COLD FRONT. WED-THU...VFR/MVFR WITH CHC OF RAIN. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR ABOUT EASTERN THIRD OF CWA THROUGH THIS EVENING. THE CLOSED UPPER LOW IS EXPECTED TO CLOSE TRACK SLOWLY TO THE EAST AND OFF MID ATLC COAST LATE TODAY AND TONIGHT. THIS WILL PRODUCE A FEW MORE NWWD BANDS OF MDT TO HEAVY RAIN OVER SCENT AND EASTERN PENN TODAY. THE HIGHER AMOUNTS STILL LOOK TO BE FOCUSED ACROSS THE SCENT MTNS...LOWER SUSQ VALLEY AND ECENT MTNS...AS THE DEFORMATION ZONE TO THE N/W OF THE UPPER LOW CENTER MOVES TO THE EAST AS WELL. THE RAIN MAY NOT MOVE OUT ENTIRELY UNTIL MIDNIGHT OR LATER. THUS...THE WATCH MAY NEED TO BE EXTENDED TO COVER THE PERIOD OF RUNOFF. BUT HAVE NOT MADE THIS MOVE QUITE YET. LOCALIZED STORM TOTAL AMOUNTS OF UP TO 2 INCHES ARE LIKELY OVER THE EAST. THIS WILL CAUSE SIGNIFICANT RISES ON THE SMALL STREAMS AND SOME MAY BE RISING TO BANKFULL BEFORE NOON. MANY OF THE LARGER WATERWAYS MAY GET TO THEIR CAUTION STAGES...BUT THESE EFFECTS WOULD BE DELAYED FOR A PERIOD OR TWO. THE MAINSTEM RIVER IS ALREADY PROGGED TO REACH CAUTION STAGES AT MANY PLACES WITH CURRENT QPF IN THE HYDRO MODEL. MMEFS PROBS FOR EXCEDENCE MAY BE UNDERDONE IN THE SREF DATA...MAINLY DUE TO THE SHIFTING QPF AREAS/CENTERS AMONGST THE MEMBERS. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ028-036-037-041- 042-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ042. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...DANGELO/LAMBERT LONG TERM...CERU/COLBERT AVIATION...LAMBERT/GARTNER HYDROLOGY...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
350 PM EDT SUN MAR 30 2014 .SYNOPSIS... A DEEPENING STORM WILL MOVE VERY SLOWLY EAST FROM THE VIRGINIA PIEDMONT TO THE SOUTHERN NEW JERSEY COAST BY SUNDAY EVENING. A RIDGE OF HIGH PRESSURE WILL SLIDE OVERHEAD ON MONDAY AND LEAD TO FAIR AND MILDER TEMPERATURES FOR THE FIRST HALF OF THE WEEK. UNSETTLED CONDITIONS ARE EXPECTED TO RETURN FOR THE SECOND HALF OF THE WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 330PM...A SLOW MOVING BAND OF RAIN-SNOW-SLEET CONTINUED TO ONLY SLOWLY DRIFT OVER MY EASTERN ZONES. MADE SOME FAST CHANGES TO THE WINTER WEATHER ADVISORY FOR SULLIVAN COUNTY TO EXTEND IT INTO THE EVENING. I ALSO INCLUDED A SLUSHY INCH OR SNOW POSSIBLE OVER THE LOWER SUSQ VALLEY WHERE A WINTRY MIX OF SLEET AND SNOW IS OCCURRING UNDER THE BAND. WHERE PRECIP RATES ARE HEAVY ENOUGH...SOME LOCALLY HEAVY SNOW IS BEING OBSERVED. STILL THINKING MOST OF THE SNOW SHOULD BE CONFINED TO GRASSY SURFACES...BUT THE ROADS COULD BECOME SLIPPERY AND SLUSHY IN THE MORE PERSISTENT HEAVY SNOW BANDS. FROM EARLIER... REGIONAL RADAR MOSAIC AT 19Z SHOWS AN EXTENSIVE...AND NEARLY STATIONARY BAND OF MODERATE TO HEAVY RAIN OVER THE SUSQ MAINSTEM /AND POINTS WEST TO INTERSTATE 81 ACROSS SCENT PENN/ THIS AREA OF PERSISTENT/HEAVY PRECIP IS OCCURRING AS A RESULT OF THE COMBINED EFFECTS OF A MODERATELY STRONG DEFORMATION BAND AND MID-LEVEL FGEN FORCING /ENHANCED BY A WELL-DEFINED SPOKE OF VORTICITY SPIRALING AROUND THE NWRN EDGE OF THE SLOW MOVING UPPER LOW CENTERED OVER THE DELMARVA PENINSULA/. FLOOD WATCH REMAINS IN EFFECT UNTIL 8 PM THIS EVENING FOR THE EASTERN HALF OF THE STATE WHILE THE LOCALIZED VERY HEAVY RAIN ACROSS PORTIONS OF SCENT PENN HAVE PROMPTED US TO UPGRADE OUR EARLIER FLOOD ADVISORY TO A FLOOD WARNING FOR ADAMS AND YORK COUNTIES...WITH THE YELLOW BREECHES CREEK AT CAMP HILL FORECAST TO EXCEED FS TONIGHT. DEEP LAYER CAA WILL HELP TO GRADUALLY MIX...THEN CHANGE THE RAIN OVER TO WET SNOW ACROSS EVEN THE SOUTHERN VALLEYS LATE THIS AFTERNOON AND EARLY THIS EVENING...WHILE A GRADUAL DECREASING TREND IN THE LIGHTER SNOW OCCURS ACROSS THE NRN AND WESTERN MTNS OF THE STATE. CANCELLED THE WINT WX ADVISORY FOR ALL BUT SULLIVAN COUNTY...WHICH STILL RUNS THROUGH 4 PM TODAY. THIS MAY NEED TO BE EXTENDED A FEW HOURS BASED ON THE LATEST 18Z RAP. 15Z/18Z RAP DOING AN EXCELLENT JOB SIMULATING THIS NEARLY STATIONARY/SLOWLY WWD DRIFTING BAND OF HEAVIER PRECIP SWIRLING AROUND THE 546 DAM UPPER LOW. THESE MODELS SHOW A TREND OF MAINTAINING THIS RATHER HIGH RAINFALL INTENSITY /AND RATE OF AT LEAST .3 TO .6 OF AN INCH PER HOUR/ BEFORE CHANGING IT TO A FEW TO SVRL HOUR PERIOD OF /WET/ SNOW EARLY THIS EVENING...THEN SLOWLY WEAKENING THE PRECIP RATES AND SLOWLY SHIFTING THE AREA EAST ACROSS THE LOWER SUSQ REGION AND ECENT MTNS TONIGHT. ADDITIONAL QPF /LIKELY BETWEEN 0.5-1.0 INCH OF ADDITIONAL RAIN AND MELTED WET SNOW ACROSS THE SCENT ZONES AND LOWER SUSQ REGION/ WILL GRADUALLY TREND LOWER...THEN DIMINISH QUICKLY AS YOU HEAD NW TWD THE I-99/RT 220 CORRIDOR. THIS WILL LEAD TO A RAIN/WET SNOW MIXTURE WITH LITTLE OR NO ACCUM AT ELEVATIONS AOB 1400 FT MSL. MAINLY RAIN /MDT TO HVY AT TIMES/ WILL PERSIST ACROSS THE LOWER SUSQ VALLEY THROUGH THE LATE AFTERNOON WITH BIG...SLOPPY WET SNOWFLAKES MIXING IN TO THE WEST OF I-83. TEMPS ALOFT REMAIN JUST WARM ENOUGH FOR ALL RAIN IN THE FAR SE INVOF KLNS. SOME OF THE HIGHER TERRAIN OF SCENT...AND ECENT PENN /MAINLY AOA 1400 FT MSL/ COULD START TO SEE A GROUND COVERING OF WET SNOW LATER THIS AFTERNOON AND EVENING AS A FEW ADDITIONAL SPOKES OF VORTICITY AND N/S PRECIP BANDS ROTATE WWD AROUND THE UPPER LOW. 2-DAY STORM TOTAL RAINFALL AND MELTED SNOW BY MIDNIGHT TONIGHT HAVE REACHED 4-5 INCHES OVER PORTIONS OF SCENT PENN /ADAMS AND YORK COUNTIES/...JUST WEST OF THE SUSQ RIVER...WHILE OTHER LOCATIONS THROUGHOUT EASTERN CENTRAL AND EASTERN SECTIONS OF THE CWA COME IN BETWEEN 1.5 AND 2.5 INCHES. WET SNOW WILL CONTINUE TO TAPER OFF IN THE WEST THROUGH THIS AFTERNOON AS THE CENTER OF THE UPPER LOW MOVES FARTHER TO THE EAST AND SIGNIFICANT LIFT EXITS WITH IT. THE OTHER INCREASINGLY NOTABLE ASPECT OF THE WEATHER WILL BE THE GUSTY 30-40 MPH WIND THAT WILL BE DEVELOPING IN THE STRENGTHENING LLVL PRESSURE GRADIENT JUST IN THE WAKE OF THIS CURRENT SYSTEM. && .SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/... RAIN AND WET SNOW WILL CONTINUE INTO THE NIGHT OVER THE FAR EAST...WITH MINOR ACCUMS OF A COATING TO ONE INCH /PERHAPS 2 INCHES ON THE RIDGES AOA 1600 FT MSL FROM SCHUYLKILL CTY...NORTH TO SULLIVAN CTY. HIGH PRESSURE RIDGE BUILDS IN BEHIND THE STORM FOR MONDAY. RESIDUAL MSTR WILL PROBABLY HOLD CLOUDS IN THE WRN MTS AT FIRST...BUT CLEARING SHOULD OCCUR EVERYWHERE THROUGH THE AFTERNOON. TEMPS SHOULD RECOVER VERY NICELY AS 8H TEMPS SHOOT BACK INTO THE MID SINGLE DIGITS ABOVE ZERO. AREAS WITH SNOW ON THE GROUND MAY HAVE A BIT OF A DELAY IN THE RECOVERY...BUT ALMOST- APRIL SUNSHINE SHOULD DO SOME GOOD MELTING. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... LATEST MODEL SOLUTIONS CONTINUE TO SLOW DOWN THE PROGRESSION OF THE INCOMING STORM. THIS SHOULD RESULT IN LINGERING SHOWERS OVER THE EAST SUNDAY NIGHT. THE COLD NORTHERLY FLOW COULD ALLOW FOR A RAIN SNOW MIX ALONG THE HIGHER ELEVATIONS WITH RAIN LINGERING INTO MONDAY MORNING DEPENDING ON THE SPEED OF THE LOW. THE EC/GFS HAS THE UPPER LOW FINALLY MOVING FURTHER INTO THE ATLANTIC BY LATE MONDAY MORNING. AT THIS POINT...MONDAY WILL BE ONE OF THE BEST DAYS OF THE EXTENDED FORECAST WITH HIGH PRESSURE...FAIR SKIES...AND SEASONABLE TEMPERATURES. ENSEMBLES AS A WHOLE ARE TRENDING WARMER IN THE NEXT WEEK. SO MORE SEASONABLE TEMPERATURES ARE ON THE HORIZON. AN UPPER LEVEL TROUGH WILL SLIDE ALONG THE NORTHERN BORDER LATE TUESDAY EVENING. SYSTEM WILL BE MORE MOISTURE STARVED SO PRECIPITATION IS LESS LIKELY. WEAK SOUTHWESTERLY FLOW COULD ALLOW FOR A SLIGHT CHANCE FOR PRECIPITATION ALONG THE SW MTNS...HOWEVER THIS IS LESS LIKELY CONSIDERING THE RIDGE THAT SHOULD BE IN PLACE. AN UPPER LEVEL LOW MOVING THROUGH THE REGION LATE NEXT WEEK WILL BE THE NEXT CHANCE FOR PRECIPITATION AFTER THIS WEEKENDS STORM. THERE IS STILL VARIATION ON POSITION AND TIMING...BUT RAIN SHOWERS ARE POSSIBLE AS EARLY AS THURSDAY AFTERNOON AS THE ASSOCIATED WARM FRONT NOSES INTO PENNSYLVANIA. THE COLD FRONT WILL MOVE THROUGH THE AREA DURING THE FIRST PART OF THE WEEKEND BRINGING MORE RAIN. DEPENDING ON THE SPEED OF THE LOW...PRECIPITATION COULD LINGER INTO SUNDAY. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... A COMPLEX AREA OF LOW PRESSURE OVER THE DELMARVA REGION THIS AFTERNOON WILL MOVE ONLY SLOWLY EAST THROUGH THE RES OF THE DAYLIGHT HOURS...KEEPING WEATHER UNSETTLED THROUGH MUCH OF THE TAF PERIOD. WIDESPREAD MVFR CIGS AND VISBYS /WITH AREAS OF IFR/ IN RAIN WET SNOW WILL PERSIST THROUGH THIS AFTERNOON...WITH IFR/LIFR CONDS MOST PREVALENT ACROSS THE WRN AND NWRN MTNS...JST AND BFD. AS THE DEEP SFC LOW REMAINS NEAR TO THE COAST...WINDS SUSTAINED BETWEEN 15-25 MPH WITH HIGHER GUSTS WILL BE PREVALENT AT ALL AIRFIELDS INTO TONIGHT. HIGH CONFIDENCE IN GUSTS AOB 25KTS BETWEEN 18Z TODAY AND 04Z MONDAY. OUTLOOK... MON...LOW CIGS RAIN/SNOW ENDING ERN SXNS EARLY BCMG VFR. MVFR/IFR CIGS WEST BCMG VFR. TUE...VFR WITH OCNL MVFR PSBL IN SCT SHRA ASSOCD WITH COLD FRONT. WED-THU...VFR/MVFR WITH CHC OF RAIN. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR ABOUT EASTERN THIRD OF CWA THROUGH THIS EVENING. THE CLOSED UPPER LOW IS EXPECTED TO CLOSE TRACK SLOWLY TO THE EAST AND OFF MID ATLC COAST LATE TODAY AND TONIGHT. THIS WILL PRODUCE A FEW MORE NWWD BANDS OF MDT TO HEAVY RAIN OVER SCENT AND EASTERN PENN TODAY. THE HIGHER AMOUNTS STILL LOOK TO BE FOCUSED ACROSS THE SCENT MTNS...LOWER SUSQ VALLEY AND ECENT MTNS...AS THE DEFORMATION ZONE TO THE N/W OF THE UPPER LOW CENTER MOVES TO THE EAST AS WELL. THE RAIN MAY NOT MOVE OUT ENTIRELY UNTIL MIDNIGHT OR LATER. THUS...THE WATCH MAY NEED TO BE EXTENDED TO COVER THE PERIOD OF RUNOFF. BUT HAVE NOT MADE THIS MOVE QUITE YET. LOCALIZED STORM TOTAL AMOUNTS OF UP TO 2 INCHES ARE LIKELY OVER THE EAST. THIS WILL CAUSE SIGNIFICANT RISES ON THE SMALL STREAMS AND SOME MAY BE RISING TO BANKFULL BEFORE NOON. MANY OF THE LARGER WATERWAYS MAY GET TO THEIR CAUTION STAGES...BUT THESE EFFECTS WOULD BE DELAYED FOR A PERIOD OR TWO. THE MAINSTEM RIVER IS ALREADY PROGGED TO REACH CAUTION STAGES AT MANY PLACES WITH CURRENT QPF IN THE HYDRO MODEL. MMEFS PROBS FOR EXCEDENCE MAY BE UNDERDONE IN THE SREF DATA...MAINLY DUE TO THE SHIFTING QPF AREAS/CENTERS AMONGST THE MEMBERS. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ028-036-037-041- 042-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ042. && $$ SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...DANGELO/LAMBERT LONG TERM...CERU/COLBERT AVIATION...LAMBERT/GARTNER HYDROLOGY...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
311 PM EDT SUN MAR 30 2014 .SYNOPSIS... A DEEPENING STORM WILL MOVE VERY SLOWLY EAST FROM THE VIRGINIA PIEDMONT TO THE SOUTHERN NEW JERSEY COAST BY SUNDAY EVENING. A RIDGE OF HIGH PRESSURE WILL SLIDE OVERHEAD ON MONDAY AND LEAD TO FAIR AND MILDER TEMPERATURES FOR THE FIRST HALF OF THE WEEK. UNSETTLED CONDITIONS ARE EXPECTED TO RETURN FOR THE SECOND HALF OF THE WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... REGIONAL RADAR MOSAIC AT 19Z SHOWS AN EXTENSIVE...AND NEARLY STATIONARY BAND OF MODERATE TO HEAVY RAIN OVER THE SUSQ MAINSTEM /AND POINTS WEST TO INTERSTATE 81 ACROSS SCENT PENN/ THIS AREA OF PERSISTENT/HEAVY PRECIP IS OCCURRING AS A RESULT OF THE COMBINED EFFECTS OF A MODERATELY STRONG DEFORMATION BAND AND MID-LEVEL FGEN FORCING /ENHANCED BY A WELL-DEFINED SPOKE OF VORTICITY SPIRALING AROUND THE NWRN EDGE OF THE SLOW MOVING UPPER LOW CENTERED OVER THE DELMARVA PENINSULA/. FLOOD WATCH REMAINS IN EFFECT UNTIL 8 PM THIS EVENING FOR THE EASTERN HALF OF THE STATE WHILE THE LOCALIZED VERY HEAVY RAIN ACROSS PORTIONS OF SCENT PENN HAVE PROMPTED US TO UPGRADE OUR EARLIER FLOOD ADVISORY TO A FLOOD WARNING FOR ADAMS AND YORK COUNTIES...WITH THE YELLOW BREECHES CREEK AT CAMP HILL FORECAST TO EXCEED FS TONIGHT. DEEP LAYER CAA WILL HELP TO GRADUALLY MIX...THEN CHANGE THE RAIN OVER TO WET SNOW ACROSS EVEN THE SOUTHERN VALLEYS LATE THIS AFTERNOON AND EARLY THIS EVENING...WHILE A GRADUAL DECREASING TREND IN THE LIGHTER SNOW OCCURS ACROSS THE NRN AND WESTERN MTNS OF THE STATE. CANCELLED THE WINT WX ADVISORY FOR ALL BUT SULLIVAN COUNTY...WHICH STILL RUNS THROUGH 4 PM TODAY. THIS MAY NEED TO BE EXTENDED A FEW HOURS BASED ON THE LATEST 18Z RAP. 15Z/18Z RAP DOING AN EXCELLENT JOB SIMULATING THIS NEARLY STATIONARY/SLOWLY WWD DRIFTING BAND OF HEAVIER PRECIP SWIRLING AROUND THE 546 DAM UPPER LOW. THESE MODELS SHOW A TREND OF MAINTAINING THIS RATHER HIGH RAINFALL INTENSITY /AND RATE OF AT LEAST .3 TO .6 OF AN INCH PER HOUR/ BEFORE CHANGING IT TO A FEW TO SVRL HOUR PERIOD OF /WET/ SNOW EARLY THIS EVENING...THEN SLOWLY WEAKENING THE PRECIP RATES AND SLOWLY SHIFTING THE AREA EAST ACROSS THE LOWER SUSQ REGION AND ECENT MTNS TONIGHT. ADDITIONAL QPF /LIKELY BETWEEN 0.5-1.0 INCH OF ADDITIONAL RAIN AND MELTED WET SNOW ACROSS THE SCENT ZONES AND LOWER SUSQ REGION/ WILL GRADUALLY TREND LOWER...THEN DIMINISH QUICKLY AS YOU HEAD NW TWD THE I-99/RT 220 CORRIDOR. THIS WILL LEAD TO A RAIN/WET SNOW MIXTURE WITH LITTLE OR NO ACCUM AT ELEVATIONS AOB 1400 FT MSL. MAINLY RAIN /MDT TO HVY AT TIMES/ WILL PERSIST ACROSS THE LOWER SUSQ VALLEY THROUGH THE LATE AFTERNOON WITH BIG...SLOPPY WET SNOWFLAKES MIXING IN TO THE WEST OF I-83. TEMPS ALOFT REMAIN JUST WARM ENOUGH FOR ALL RAIN IN THE FAR SE INVOF KLNS. SOME OF THE HIGHER TERRAIN OF SCENT...AND ECENT PENN /MAINLY AOA 1400 FT MSL/ COULD START TO SEE A GROUND COVERING OF WET SNOW LATER THIS AFTERNOON AND EVENING AS A FEW ADDITIONAL SPOKES OF VORTICITY AND N/S PRECIP BANDS ROTATE WWD AROUND THE UPPER LOW. 2-DAY STORM TOTAL RAINFALL AND MELTED SNOW BY MIDNIGHT TONIGHT HAVE REACHED 4-5 INCHES OVER PORTIONS OF SCENT PENN /ADAMS AND YORK COUNTIES/...JUST WEST OF THE SUSQ RIVER...WHILE OTHER LOCATIONS THROUGHOUT EASTERN CENTRAL AND EASTERN SECTIONS OF THE CWA COME IN BETWEEN 1.5 AND 2.5 INCHES. WET SNOW WILL CONTINUE TO TAPER OFF IN THE WEST THROUGH THIS AFTERNOON AS THE CENTER OF THE UPPER LOW MOVES FARTHER TO THE EAST AND SIGNIFICANT LIFT EXITS WITH IT. THE OTHER INCREASINGLY NOTABLE ASPECT OF THE WEATHER WILL BE THE GUSTY 30-40 MPH WIND THAT WILL BE DEVELOPING IN THE STRENGTHENING LLVL PRESSURE GRADIENT JUST IN THE WAKE OF THIS CURRENT SYSTEM. && .SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/... RAIN AND WET SNOW WILL CONTINUE INTO THE NIGHT OVER THE FAR EAST...WITH MINOR ACCUMS OF A COATING TO ONE INCH /PERHAPS 2 INCHES ON THE RIDGES AOA 1600 FT MSL FROM SCHUYLKILL CTY...NORTH TO SULLIVAN CTY. HIGH PRESSURE RIDGE BUILDS IN BEHIND THE STORM FOR MONDAY. RESIDUAL MSTR WILL PROBABLY HOLD CLOUDS IN THE WRN MTS AT FIRST...BUT CLEARING SHOULD OCCUR EVERYWHERE THROUGH THE AFTERNOON. TEMPS SHOULD RECOVER VERY NICELY AS 8H TEMPS SHOOT BACK INTO THE MID SINGLE DIGITS ABOVE ZERO. AREAS WITH SNOW ON THE GROUND MAY HAVE A BIT OF A DELAY IN THE RECOVERY...BUT ALMOST- APRIL SUNSHINE SHOULD DO SOME GOOD MELTING. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... LATEST MODEL SOLUTIONS CONTINUE TO SLOW DOWN THE PROGRESSION OF THE INCOMING STORM. THIS SHOULD RESULT IN LINGERING SHOWERS OVER THE EAST SUNDAY NIGHT. THE COLD NORTHERLY FLOW COULD ALLOW FOR A RAIN SNOW MIX ALONG THE HIGHER ELEVATIONS WITH RAIN LINGERING INTO MONDAY MORNING DEPENDING ON THE SPEED OF THE LOW. THE EC/GFS HAS THE UPPER LOW FINALLY MOVING FURTHER INTO THE ATLANTIC BY LATE MONDAY MORNING. AT THIS POINT...MONDAY WILL BE ONE OF THE BEST DAYS OF THE EXTENDED FORECAST WITH HIGH PRESSURE...FAIR SKIES...AND SEASONABLE TEMPERATURES. ENSEMBLES AS A WHOLE ARE TRENDING WARMER IN THE NEXT WEEK. SO MORE SEASONABLE TEMPERATURES ARE ON THE HORIZON. AN UPPER LEVEL TROUGH WILL SLIDE ALONG THE NORTHERN BORDER LATE TUESDAY EVENING. SYSTEM WILL BE MORE MOISTURE STARVED SO PRECIPITATION IS LESS LIKELY. WEAK SOUTHWESTERLY FLOW COULD ALLOW FOR A SLIGHT CHANCE FOR PRECIPITATION ALONG THE SW MTNS...HOWEVER THIS IS LESS LIKELY CONSIDERING THE RIDGE THAT SHOULD BE IN PLACE. AN UPPER LEVEL LOW MOVING THROUGH THE REGION LATE NEXT WEEK WILL BE THE NEXT CHANCE FOR PRECIPITATION AFTER THIS WEEKENDS STORM. THERE IS STILL VARIATION ON POSITION AND TIMING...BUT RAIN SHOWERS ARE POSSIBLE AS EARLY AS THURSDAY AFTERNOON AS THE ASSOCIATED WARM FRONT NOSES INTO PENNSYLVANIA. THE COLD FRONT WILL MOVE THROUGH THE AREA DURING THE FIRST PART OF THE WEEKEND BRINGING MORE RAIN. DEPENDING ON THE SPEED OF THE LOW...PRECIPITATION COULD LINGER INTO SUNDAY. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... A COMPLEX AREA OF LOW PRESSURE OVER THE DELMARVA REGION THIS AFTERNOON WILL MOVE ONLY SLOWLY EAST THROUGH THE RES OF THE DAYLIGHT HOURS...KEEPING WEATHER UNSETTLED THROUGH MUCH OF THE TAF PERIOD. WIDESPREAD MVFR CIGS AND VISBYS /WITH AREAS OF IFR/ IN RAIN WET SNOW WILL PERSIST THROUGH THIS AFTERNOON...WITH IFR/LIFR CONDS MOST PREVALENT ACROSS THE WRN AND NWRN MTNS...JST AND BFD. AS THE DEEP SFC LOW REMAINS NEAR TO THE COAST...WINDS SUSTAINED BETWEEN 15-25 MPH WITH HIGHER GUSTS WILL BE PREVALENT AT ALL AIRFIELDS INTO TONIGHT. HIGH CONFIDENCE IN GUSTS AOB 25KTS BETWEEN 18Z TODAY AND 04Z MONDAY. OUTLOOK... MON...LOW CIGS RAIN/SNOW ENDING ERN SXNS EARLY BCMG VFR. MVFR/IFR CIGS WEST BCMG VFR. TUE...VFR WITH OCNL MVFR PSBL IN SCT SHRA ASSOCD WITH COLD FRONT. WED-THU...VFR/MVFR WITH CHC OF RAIN. && .HYDROLOGY... FLOOD WATCH CONTINUES FOR ABOUT EASTERN THIRD OF CWA THROUGH THIS EVENING. THE CLOSED UPPER LOW IS EXPECTED TO CLOSE TRACK SLOWUY TO THE EAST AND OFF MID ATLC COAST LATE TODAY AND TONIGHT. THIS WILL PRODUCE A FEW MORE NWWD BANDS OF MDT TO HEAVY RAIN OVER SCENT AND EASTERN PENN TODAY. THE HIGHER AMOUNTS STILL LOOK TO BE FOCUSED ACROSS THE SCENT MTNS...LOWER SUSQ VALLEY AND ECENT MTNS...AS THE DEFORMATION ZONE TO THE N/W OF THE UPPER LOW CENTER MOVES TO THE EAST AS WELL. THE RAIN MAY NOT MOVE OUT ENTIRELY UNTIL MIDNIGHT OR LATER. THUS...THE WATCH MAY NEED TO BE EXTENDED TO COVER THE PERIOD OF RUNOFF. BUT HAVE NOT MADE THIS MOVE QUITE YET. LOCALIZED STORM TOTAL AMOUNTS OF UP TO 2 INCHES ARE LIKELY OVER THE EAST. THIS WILL CAUSE SIGNIFICANT RISES ON THE SMALL STREAMS AND SOME MAY BE RISING TO BANKFULL BEFORE NOON. MANY OF THE LARGER WATERWAYS MAY GET TO THEIR CAUTION STAGES...BUT THESE EFFECTS WOULD BE DELAYED FOR A PERIOD OR TWO. THE MAINSTEM RIVER IS ALREADY PROGGED TO REACH CAUTION STAGES AT MANY PLACES WITH CURRENT QPF IN THE HYDRO MODEL. MMEFS PROBS FOR EXCEEDENCE MAY BE UNDERDONE IN THE SREF DATA...MAINLY DUE TO THE SHIFTING QPF AREAS/CENTERS AMONGST THE MEMBERS. && .CTP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ028-036-037-041- 042-046-049>053-056>059-063>066. WINTER WEATHER ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR PAZ042. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...CERU/COLBERT AVIATION...LAMBERT HYDROLOGY...LAMBERT
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
112 PM EDT SUN MAR 30 2014 .SYNOPSIS... AN UPPER LEVEL LOW WILL SHIFT OFF THE COAST THIS AFTERNOON. HIGH PRESSURE WILL RETURN TO THE AREA LATE TONIGHT AND MONDAY. A FRONT MOVES THROUGH BY TUESDAY NIGHT BUT LOOKS DRY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 100 PM EDT SUNDAY... WILL BE DROPPING THE GOING WINTER WEATHER HEADLINES AS SNOW SHOWERS HAVE FINALLY DIMINISHED TO ONE SMALLER BAND ALONG THE BLUE RIDGE THAT SHOULD FADE SHORTLY. TEMPS HAVE ALSO WARMED ENOUGH OUTSIDE OF THE HIGHER ELEVATIONS TO LIMIT ANY ADDED ACCUMULATION THE REST OF THE AFTERNOON. WILL ALSO LOWER POPS AND ADJUST TEMPS. AS OF 1030 AM EDT SUNDAY... PERSISTENT BANDS OF HEAVY SNOW CONTINUE TO SPILL SOUTH FROM BATH COUNTY EAST TO AMHERST WITH ELEVATION ALLOWING SNOW TO QUICKLY ACCUMULATE TO BETTER THAN 6 INCHES IN STRIPS ALONG THE I-64 TO I-81 CORRIDOR UP NORTH. LATEST RAP AND LOCAL MODEL SOLNS SUGGEST ANOTHER HOUR OR SO OF ACCUMULATING SNOWFALL IN THESE AREAS BEFORE THE DEFORMATION AREA FINALLY SHIFTS SE AND WEAKENS. THUS WILL KEEP THE ADVISORY GOING ACROSS PARTS OF THE SOUTHERN SHENANDOAH VALLEY WHILE INCLUDING LOCALLY HIGHER TOTALS GIVEN THE HUGE RANGE ACROSS COUNTIES WITH LITTLE AT LOWER ELEVATIONS. ELSEWHERE SHOULD BE WARM ENOUGH FOR MOSTLY RAIN FARTHER SOUTH WITH ONLY SOME SNOW MIXED IN NORTH OF HIGHWAY 460 FOR A WHILE LONGER. PRECIP HAS TAPERED WEST OF THE NEW RIVER VALLEY SO WILL BE REMOVING COUNTIES FROM THE WINTER WX ADVISORY THERE WHILE KEEPING THE WARNINGS GOING INTO SE WVA GIVEN SOME CONTININUING LIGHT SNOWFALL. LITTLE CHANGE TO GOING WIND HEADLINES WITH THE STRONGEST SPEEDS CONTINUING ALONG THE SOUTHERN BLUE RIDGE BUT LIKELY TO SHIFT NE AS SOME BREAKS DEVELOP THIS AFTERNOON UNDER A SECONDARY LOW LEVEL JET MAX THAT LOOKS TO PIVOT ACROSS BY MID AFTERNOON. BEEFED UP CLOUDS LONGER PER LATEST VIS PICS WITH TEMPS REMAINING BELOW MOS SO LOWERED A CAT OR SO ACROSS THE REGION FOR THE AFTERNOON. AS OF 915 AM EDT SUNDAY... QUICK UPDATE TO ADD THE HIGHER ELEVATIONS OF ROCKBRIDGE AND AMHERST TO THE GOING WINTER WEATHER ADVISORY DUE TO HEAVIER SNOW BANDS ON THE BACK EDGE OF THE DEFORMATION ZONE. EXPECT MOST ACCUMULATION TO BE NEAR THE BLUE RIDGE PARKWAY WITH LESS THAN AN INCH ELSEWHERE ACROSS THAT REGION. ALSO BUMPED UP AMOUNTS ACROSS NORTHERN BATH WHERE HAVE ALREADY SEEN 2-3 INCHES. REMAINDER UNCHANGED AS EXPECT LESS AND LESS ACCUMULATION WITH SOME SLOW WARMING DURING THE MORNING HOURS. STRONGER WINDS ALONG THE BLUE RIDGE MAY BE REALIZED OVER THE NEXT FEW HOURS BUT WILL NEED SOME CLEARING TO ENHANCE MIXING WHICH MAY NOT HAPPEN IN TIME BUT WILL CONTINUE THE WARNING FOR NOW. PREVIOUS DISCUSSION AS OF 720 AM EDT SUNDAY... RADAR CONTINUES TO SHOW DEFORMATION AXIS PIEDMONT WITH NW FLOW RAIN AND SNOW SHOWERS OVER THE WEST. RADAR OVERSHOOTING THE SNOW PAST I-77 AND IN NC MTNS. MODELS AGREE THAT DRYING TAKES PLACE FROM SW TO NE THROUGH THE MORNING AND WILL SEE SNOW SHOWERS AND RAIN OUT EAST START TO WANE LATE MORNING INTO MID AFTERNOON. STILL LOOKS LIKE A GOOD 2-6 INCHES POSSIBLE OF SNOW IN THE HIGHER ELEVATIONS...AND SOME POCKETS OF 1-3 INCHES IN NARROW CORRIDORS FROM SE WV INTO THE NW NC MTNS AND NEW RIVER VALLEY. WIND WILL KEEP THE SNOW MEASURING AN ISSUE...AND OVERALL WINDS WILL BE GUSTY BUT STRONGEST WINDS WILL ARRIVE AS CLEARING TAKES PLACE AND STILL LOOKING AFTERNOON FOR MOST. ALREADY HAVE HAD GUSTS OVER 65 MPH AT BOONE...AND A TREE DOWN IN TODD NC. NO CHANGES WERE MADE TO THE HEADLINES. PREVIOUS DISCUSSION ISSUED EARLIER THIS MORNING... OVERALL...MARCH IS TRYING TO GO OUT LIKE A LION...BUT IT WILL HAVE TO SETTLE FOR THE DAY BEFORE THE END OF THE MONTH. RADAR THIS MORNING SHOWS THE DEFORMATION ZONE PRECIP LIFTING NWD ACROSS THE ALLEGHANY HIGHLANDS SOUTHEAST TOWARD SOUTHSIDE VA. THE PRECIP OVER THE MOUNTAINS HAS CHANGED TO ALL SNOW...BUT SO FAR LITTLE ACCUMULATION REPORTS...ALTHOUGH THINK MORE WILL BE COMING IN AS WE HEAD TOWARD DAYLIGHT HOURS. NICE CYCLONIC FLOW SEEN IN THE RADAR ECHOES AS WELL...WITH UPSLOPE WELL UNDER WAY OVER THE NC MTNS...NWD INTO SE WV. HAVE NOT MADE ANY ADDITIONAL CHANGES TO THE HEADLINES...BUT THE WINDS WILL BE HIT AND MISS THIS MORNING THANKS TO THE CLOUD COVER. AS WE HEAD THRU THE DAY...THE UPPER LOW WILL MOVE EAST OF THE DELMARVA WITH STRONG NVA ARRIVING WHICH HELPS TO MIX OUT THE CLOUDS. FORECAST MOS GUIDANCE AND BUFKIT SOUNDINGS STILL SUGGEST STRONG WINDS ESPECIALLY THIS AFTERNOON. SOME AREAS WILL NOT REALLY GET TO ADVISORY OR WARNING LEVELS BUT GIVEN WET GROUNDS...WIND SPEEDS JUST BELOW WILL CAUSE SOME PROBLEMS. WHERE THE WARNING IS IN PLACE...THINK 50 TO 60 MPH GUSTS ARE LIKELY AND FEEL THAT TREES ARE GOING TO BE BLOWN DOWN. HOPEFULLY...NO DAMAGE TO HOMES OR BUSINESSES WILL OCCUR. ADVISORY AREAS WILL BE MORE FORTUNATE BUT EXPECT SOME TREE DOWN REPORTS AS WELL. THE SNOW WILL ALSO TAPER OFF THIS AFTERNOON AS THE UPPER LOW MOVES AWAY. STILL LOOKS LIKE ELEVATIONS ABOVE 3000 FT WILL GET AS MUCH AS 6 INCHES WHEN ALL IS SAID AND DONE...ESPECIALLY WRN GREENBRIER. MOIST/WET GROUND WILL HAVE SOME IMPACT ON STICKING...BUT RATE SHOULD BE HIGH ENOUGH TO GIVE THE HIGHER VALLEYS IN THE WEST A 1-2 INCH COATING. THOUGH NO ADVISORY IS IN PLACE FOR SNOW ALONG THE BLUE RIDGE...THINK LOCATIONS SUCH AS POOR MOUNTAIN...PEAKS OF OTTER AND APPLE ORCHARD MOUNTAIN COULD SEE 1 TO 3 INCHES OF SNOW. HIGHS TODAY WILL BE TRICKY GIVEN COLD AIR ADVECTION THIS MORNING...THEN NEUTRAL ADVECTION THIS AFTERNOON...PLUS LATE MARCH SUN AND DOWNSLOPE. WENT WITH MID 50S EAST OF THE BLUE RIDGE...TO 40S WEST...WITH 30S IN THE HIGHEST ELEVATIONS FROM BEECH MTN NC...MOUNT ROGERS VA AND THE WRN SLOPES OF GREENBRIER COUNTY. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 329 AM EDT SUNDAY... THE CLOSED LOW THAT WILL TRACK OVER THE FORECAST AREA TODAY WILL BECOME AN OCCLUDED LOW OFF THE DELMARVA COAST THIS EVENING. THE ASSOCIATED PRECIPITATION WITH THIS SYSTEM SHOULD BE EAST OF THE PIEDMONT BY SUNSET. MEANWHILE...HIGH PRESSURE WILL DRIFT EAST OVER THE OHIO-TENN VALLEYS TONIGHT. THE PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS WILL CONTINUE TO PRODUCE WINDY/GUSTY CONDITIONS INTO THE EVENING. THE PRESSURE GRADIENT STARTS TO LOOSEN AFTER MIDNIGHT ALLOWING WINDS TO WEAKEN ACROSS THE FOOTHILLS AND PIEDMONT. WINDY CONDITIONS WILL REMAIN ACROSS THE MOUNTAINS...PARTICULARLY ALONG THE BLUE RIDGE INTO THE EARLY MORNING HOURS MONDAY. OVERNIGHT MIXING WILL KEEP RIDGE TOP TEMPERATURES MILDER THAN THE VALLEYS. MOUNTAIN VALLEY TEMPERATURES WILL RANGE IN THE M/U20S WHILE RIDGES RANGE BETWEEN 30F-35F. EVEN THOUGH THE WINDS RELAX IN THE EAST EARLY...NOT AN IDEAL SITUATION FOR RADIATIONAL COOLING...THEREFORE KEPT OVERNIGHT TEMPERATURES IN THE 30S. WHAT A DIFFERENCE A DAY MAKES WITH MONDAYS HIGH TEMPERATURES IN THE 60S ACROSS THE WEST AND U60S-L70S IN THE EAST. RELATIVE HUMIDITIES WILL DROP INTO THE 20S MONDAY AFTERNOON WHILE NORTHWEST WINDS PEAK BETWEEN 10-15 MPH. WARMER TUESDAY WITH TEMPERATURES PUSHING 70F ACROSS THE MOUNTAINS AND WIDESPREAD 70S EAST. HUMIDITY LEVELS SLIGHTLY HIGHER AROUND 30 PERCENT TUESDAY WITH THE LOW LEVEL FLOW COMING FROM THE SOUTHWEST. BOTH DAYS LOOK IDEAL FOR PRESCRIBE BURNS WITH THE STRONGER TRANSPORT WINDS OCCURRING TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 1145 AM EDT SATURDAY... BROAD UPPER RIDGING TO REMAIN IN PLACE UNTIL NEAR THE END OF THE PERIOD WITH SURFACE HIGH PRESSURE OFF THE SE COAST AND MEAN TROUGHING ACROSS THE CENTRAL AND SW STATES. WILL SEE A WEAK SURFACE FRONT PUSH SOUTH OF THE REGION WEDNESDAY AS A WAVE PASSES WELL TO THE NORTH AND HEIGHTS DIP A BIT. HOWEVER THIS BOUNDARY INITIALLY DRY WITH ONLY WEAK HIGH PRESSURE TO THE NW WHICH SHOULD DO LITTLE TO DETER VERY WARM TEMPS FOR MIDWEEK. FRONT LOOKS TO LIFT BACK NORTH THROUGH THE REGION THURSDAY AS STRONGER LOW PRESSURE PIVOTS TOWARD THE UPPER MIDWEST. BAND OF DEEPER MOISTURE/LIFT MAY TEND TO SPILL DOWN THE BAROCLINIC ZONE FROM THE WEST SO BUMPED UP POPS STARTING THURSDAY MORNING...CONTINUING INTO THURSDAY EVENING WITH MOISTURE AROUND AND WEAK IMPULSES SLIDING BY. STRONGER COLD FRONT WITH THE WAVE TO THE WEST WILL APPROACH FRIDAY AND SHOULD PASS ACROSS THE AREA FRIDAY NIGHT INTO EARLY SATURDAY PER THE FASTER EC. EXPECT PRE- FRONTAL BAND OF SHRA TO AFFECT MUCH OF THE REGION BY FRIDAY AFTERNOON WITH SOME ISOLATED TSRA POSSIBLE SOUTH AND SW SO RUNNING WITH CHANCE TO LOW LIKELY POPS INTO FRIDAY EVENING. BOUNDARY LOOKS TO GET FAR ENOUGH SE TO ALLOW DRYING ON SATURDAY WITH ONLY SOME EARLY CLOUDS/-SHRA MAINLY NW AND CLEARING ELSW PENDING LATER RUNS. GOOD SOUTH TO SW FLOW SHOULD FINALLY BRING TEMPS UP TO SPRING LEVELS AND ALLOW THEM TO STAY THERE WITH HIGHS MOSTLY 70S EXCEPT COOLING TO 60S SATURDAY BEHIND THE FRONT. LOWS WELL ABOVE FREEZING AND PERHAPS STAYING ABOVE 50 OUT EAST DURING MIDWEEK. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... AS OF 105 PM EDT SUNDAY... LAST OF THE PERSISTENT SNOW/RAIN BANDS CONTINUING TO DIMINISH ALONG THE BLUE RIDGE AND SHOULD DISSIPATE IN THE NEXT HOUR OR TWO AS THE UPPER LOW SHIFTS FARTHER EAST. THIS SHOULD ALLOW SOME DRY SLOTTING TO TAKE PLACE FROM SOUTHWEST TO THE NORTHEAST LATER THIS THIS AFTERNOON AS THE CLOSED LOW MOVES OFF THE MID ATLANTIC COAST. HOWEVER STRONG NORTHWEST WINDS WILL PERSIST ACROSS THE REGION INTO THIS EVENING WITH GUSTS TO 40-45 KTS POSSIBLE AROUND BCB/ROA AND 30-35 KTS IN THE EAST AS WELL AS ACROSS SE WVA. OTRW IMPROVING CIGS SHOULD TAKE SHAPE WITH BLF REBOUNDING FROM LIFR/IFR TO MVFR THEN VFR AFTER 00Z/8PM AND MVFR TO VFR AT LWB. BCB MAY SEEN A COUPLE MORE HOURS OF MVFR AS WELL BEFORE ALL IMPROVE TO VFR UNDER CLEARING SKIES BY THIS EVENING. HIGH PRESSURE BUILDS IN OVERNIGHT WITH STRONG WINDS FINALLY SUBSIDING BUT STILL SOME GUSTS TO 20-25 KTS MOUNTAINS THROUGH THE OVERNIGHT. THE GRADIENT MAY DECOUPLE ENOUGH TO ALLOW VERY LIGHT WINDS AT LYH/DAN/LWB BEFORE INCREASING SOME MONDAY MORNING UNDER LIGHT MIXING. SHOULD BE GOOD FLYING WEATHER ON MONDAY WITH CLEAR SKIES AND SURFACE NW WINDS AT 5-15 KTS. EXTENDED AVIATION DISCUSSION... GENERALLY VFR CONDITIONS MONDAY NIGHT UNTIL LATE WEEK WITH A WARM FRONT LIFTING THROUGH THE AREA ON THURSDAY PERHAPS RESULTING IN MVFR CIGS AND A FEW SHOWERS. A STRONGER FRONT ARRIVING FROM THE WEST BY FRIDAY SHOULD SPELL MORE WIDESPREAD PERIODS OF MVFR IN SHOWERS HEADING INTO FRIDAY NIGHT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...HIGH WIND WARNING UNTIL 10 PM EDT THIS EVENING FOR VAZ009- 012>020-022-032-033. WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR VAZ007-010-011- 023-024-034-035-043>047-058-059. NC...HIGH WIND WARNING UNTIL 10 PM EDT THIS EVENING FOR NCZ001>003- 018-019. WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR NCZ004>006-020. WV...WIND ADVISORY UNTIL 10 PM EDT THIS EVENING FOR WVZ042>045. && $$ SYNOPSIS...NF/WP NEAR TERM...JH/WP SHORT TERM...RCS LONG TERM...JH AVIATION...JH/MBS/RAB/WP
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY ISSUED AT 301 PM CDT SUN MAR 30 2014 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE EXTENDING FROM THE LOUISIANA COAST TO NORTHERN LAKE HURON EARLY THIS AFTERNOON. TEMPERATURES HAVE BEEN SLOW TO WARM SO FAR TODAY WITH READINGS RANGING FROM THE UPPER 30S AT STURGEON BAY AND MANITOWOC TO THE MIDDLE 50S AT WISCONSIN RAPIDS. MID AND HIGH CLOUDS CONTINUE TO STREAM ACROSS NORTHERN WISCONSIN AHEAD OF A SHORTWAVE MOVING ACROSS THE ROCKIES. NO SIGNS OF GULF MOISTURE ACROSS THE PLAINS JUST YET DESPITE PREVAILING SOUTHERLY FLOW. DEWPOINTS REMAIN IN THE UPPER 30S INTO CENTRAL TEXAS. THE MAIN FORECAST CONCERNS INCLUDE TEMPS TONIGHT AND CHANCES OF PRECIP ON MONDAY. TONIGHT...LOW PRESSURE WILL EMERGE INTO THE CENTRAL PLAINS WHILE A SURFACE WARM FRONT WILL DEVELOP OVER CENTRAL OR SOUTHERN WISCONSIN. AS HEIGHT FALLS OCCUR OVER THE PLAINS...RETURN FLOW AND 850MB THETAE ADVECTION WILL BE RAMPING UP OVER THE WESTERN GREAT LAKES. BUT THE AIR ACROSS THE CENTRAL PLAINS IS SO DRY THAT PRECIP CHANCES REMAIN TOO LOW TO INCLUDE IN THE FORECAST. SHOULD SEE A GRADUAL INCREASE IN MID AND HIGH CLOUDS HOWEVER. WITH WINDS SHIFTING TO THE SOUTHEAST NORTH OF THE WARM FRONT...SHOULD MAINTAIN DRY LOW LEVEL AIRMASS ENOUGH TO LIMIT THE THREAT OF FREEZING DRIZZLE OR FOG. TEMPS TO FALL INTO THE UPPER 20S OVER NE WISCONSIN TO THE UPPER 30S SOUTH. MONDAY...A STRONG SURFACE LOW WILL HEAD TOWARDS THE NORTHERN MISSISSIPPI VALLEY BY LATE IN THE AFTERNOON. MID AND HIGH CLOUDS WILL BE THICKENING AND LOWERING OVER THE COURSE OF THE DAY...BUT DRY AIR IN THE LOW LEVELS WILL BE HOLDING OFF PRECIP CHANCES FOR MUCH OF THE DAY. THINK PRECIP CHANCES WILL IMPROVE BY MID TO LATE AFTERNOON ACROSS THE FORECAST AREA...BUT UNSURE HOW PRECIP WILL EVOLVE. EVEN THOUGH MODELS POINT TOWARDS BETTER CHANCES ACROSS NORTHERN WISCONSIN...THINK INCREASING MOISTURE TRANSPORT ALOFT AND THE ARRIVAL OF A 700MB THETAE AXIS/EDGE OF DRY SLOT COULD LEAD TO A BROKEN BAND OF LIGHT SHOWERS AND SPRINKLES PUSHING ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN MID TO LATE AFTERNOON. MODIFIED POPS A BIT TO REFLECT THIS SCENARIO...BUT STILL KEPT POPS MAINLY IN THE CHANCE RANGE DUE TO CONCERNS OF DRY AIR IN THE LOW LEVELS. WITH THE WARM FRONT NOW EXPECTED TO STALL OVER CENTRAL WISCONSIN...TEMPS MAY NOT BE THAT MUCH DIFFERENT THAN TODAY...PERHAPS A COUPLE DEGREES WARMER. .LONG TERM...MONDAY NIGHT THROUGH SUNDAY ISSUED AT 301 PM CDT SUN MAR 30 2014 THE SHORTWAVE TROUGH WILL EXIT THE NORTHERN GREAT LAKES EARLY TUESDAY WITH COLDER AND DRIER AIR ARRIVING AT THE SURFACE. THE RAIN WILL CHANGE TO SNOW SHOWERS WITH AN INCH OR SO POSSIBLE IN THE NORTH. THEN A FLAT UPPER RIDGE ARRIVES WEDNESDAY AND THURSDAY WITH COLD HIGH PRESSURE CENTERED TO OUR NORTH. SO DRY AND SLIGHTLY COLDER THAN NORMAL FOR THIS TIME OF THE YEAR. THE NEXT SYSTEM FOR THURSDAY NIGHT AND FRIDAY IS NOW OVER THE CENTRAL PACIFIC SO WE WON/T HAVE TOO MUCH CONFIDENCE IN THE MODEL SOLUTIONS FOR A FEW MORE DAYS. IT DOES LOOK INTERESTING WITH ARCTIC HIGH PRESSURE TO THE NORTH AND EAST AND STRONG UPPER SYSTEM APPROACHING FROM THE SOUTHWEST. THE ARCTIC HIGH WILL DELIVER LOW LEVEL COLD DRY AIR SO SURFACE TEMPERATURES WILL LIKELY BE BELOW FREEZING BUT ABOVE FREEZING AIR AROUND 850MB COULD MAKE FOR A MIXTURE OF SNOW...SLEET OR FREEZING RAIN. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1222 PM CDT SUN MAR 30 2014 OVER THE NEXT 24 HOURS...A WARM FRONT WILL STALL OVER CENTRAL WISCONSIN AS LOW PRESSURE MOVES ACROSS THE CENTRAL PLAINS. AHEAD OF THE LOW...MID AND HIGH CLOUDS WILL BE PASSING OVERHEAD ACROSS THE REGION. DRY LOW LEVEL AIR FROM THE CENTRAL PLAINS WILL KEEP PRECIPITATION TO THE WEST OVER THE PERIOD...BUT A TIGHTENING PRESSURE GRADIENT WILL LEAD TO THE DEVELOPMENT OF LLWS OVER MUCH OF THE REGION TONIGHT INTO MONDAY MORNING. OTHERWISE...ANTICIPATE VFR CONDITIONS TO PREVAIL THROUGH MIDDAY MONDAY...BEFORE CIGS LOWER MONDAY AFTERNOON AND EVENING. && .HYDROLOGY... ISSUED AT 301 PM CDT SUN MAR 30 2014 WARMER TEMPERATURES...MILDER WEATHER WILL PRODUCE MELTING SNOW AND ICE AND RESULT IN AN INCREASED CHANCE OF LOCAL FLOODING EARLY THIS WEEK. THE SNOW IS VERY DEEP IN THE NORTH AND SHOULD BE ABLE TO ABSORB RAINFALL WITHOUT FULLY MELTING. HOWEVER...PLACES WITH JUST A FEW INCHES LEFT ON THE GROUND MAY HAVE MOST OF THE SNOW MELT...WHICH MAY CAUSE RIVERS AND STREAMS TO RISE. THERE IS ALSO A CHANCE OF ICE JAMS AS RIVER ICE BREAKS UP. A HYDROLOGICAL OUTLOOK IS IN EFFECT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......MPC HYDROLOGY......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1238 PM CDT SUN MAR 30 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 319 AM CDT SUN MAR 30 2014 CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH SOUTH OF THE GULF OF ALASKA...A VIGOROUS SHORTWAVE TROUGH COMING INTO CENTRAL CALIFORNIA...AND A RIDGE AXIS FROM TEXAS INTO THE FORECAST AREA. PROFILER AND VAD WIND DATA SHOWED A CORRIDOR OF SOUTHWESTERLY 40-55 KT WINDS AT 925MB JUST TO THE WEST OF THE RIDGE AXIS. THESE WINDS ARE PROPELLING WARMER AIR THAT WAS OBSERVED OVER THE PLAINS YESTERDAY TOWARDS THE FORECAST AREA. ITS WORTH NOTING HIGHS YESTERDAY WERE IN THE 60S TO LOW 70S FROM WESTERN NORTH DAKOTA INTO OKLAHOMA...ASSOCIATED WITH 925MB TEMPS OF 10 TO 20C. CLOUD COVER MOSTLY OF THE SCATTERED CIRRUS VARIETY...REFLECTIVE OF UPPER LEVEL MOISTURE STREAMING FROM THE PACIFIC ON WATER VAPOR. AIRMASS ACROSS MUCH OF THE PLAINS AND THE FORECAST AREA VERY DRY PER 00Z SOUNDINGS...NOTED TOO FROM PRECIPITABLE WATER VALUES BETWEEN 0.2- 0.3 INCHES. AT THE SURFACE...THE SURFACE RIDGE THAT WAS OVER THE AREA YESTERDAY HAS SHIFTED EAST TO OVER LAKE MICHIGAN...WHILE PRESSURES ARE FALLING ALONG THE LEE OF THE ROCKIES. THE SURFACE RIDGE HAS PUSHED ANY MEANINGFUL SURFACE MOISTURE...DEWPOINTS AT OR ABOVE 40F...DOWN TO THE GULF OF MEXICO COAST. SYNOPTICALLY...THE UPPER RIDGING PRESENT OVER THE FORECAST AREA LOOKS TO PERSIST THROUGH TONIGHT...WITH A SHIFT TO THE EAST AFTER MIDNIGHT. THE PUSH EAST TO THE RIDGE IS CAUSED BY THE VIGOROUS SHORTWAVE LIFTING INTO THE FAR NORTHEAST COLORADO AREA BY 12Z MONDAY. ITS ALSO WORTH NOTING THAT THE SHORTWAVE BECOMES NEGATIVELY TILTED. WITH THE FORECAST AREA PROGGED TO BE IN THE WARM SECTOR OF A DEEPENING LOW COMING OUT OF COLORADO AND INTO CENTRAL NEBRASKA BY 12Z MONDAY...MUCH OF THE FORECAST CONCERN IS ON TEMPERATURES. 925MB TEMPS ARE PROGGED TO CONTINUE TO CLIMB THROUGH THE DAY ON A BREEZY SOUTH TO SOUTHWEST WIND...RISING FROM 1 TO 5C AT 12Z TO 9 TO 13C BY 00Z. THESE READINGS HOLD NEARLY STEADY FOR TONIGHT DUE TO PERSISTENT 25-35 KT SOUTH WINDS. COMBINATION OF THE AFOREMENTIONED WARM ADVECTION AND SUNSHINE SHOULD EASILY PUSH HIGHS INTO THE 60S ALONG AND SOUTHWEST OF I-94. NORTH OF I-94...SNOW PACK AND COOLER 925MB TEMPS WILL HOLD HIGHS BACK INTO THE 50S. THE MIXING TODAY TOO WILL BE LIMITED A LITTLE DUE TO SCT-BKN CIRRUS EMANATING FROM NEBRASKA AREA CURRENTLY. WITH A LOW LEVEL JET IN PLACE TONIGHT...MOST LOCATIONS SHOULD ONLY SEE LOWS IN THE 40S. THERE ARE INDICATIONS THE TYPICAL COLD SPOTS MIGHT DECOUPLE OR AT LEAST SEE LIGHTER WINDS...ALLOWING TEMPERATURES THERE TO DIP INTO THE UPPER 30S. PRECIPITATION-WISE...PLENTIFUL DRY AIR IN PLACE AS SEEN AT 00Z LAST EVENING WILL KEEP CONDITIONS DRY THROUGH THIS EVENING. AFTER MIDNIGHT...THERE IS GOOD AGREEMENT AMONG MODELS FOR A WARM CONVEYOR BELT OF PRECIPITATION TO DEVELOP OVER EASTERN NEBRASKA AND WESTERN IOWA. MUCH OF THIS PRECIPITATION CORRELATES WITH ISENTROPIC LIFT ON THE 305-310K SURFACES...OR AT PRESSURES ABOVE 700MB. IN ANY EVENT...AT LEAST THROUGH TONIGHT...THE FORECAST AREA STAYS DRY. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 319 AM CDT SUN MAR 30 2014 MUCH OF THE FOCUS IS ON THE MONDAY THROUGH TUESDAY PERIOD. IMPACTS DESCRIBED BELOW... SYNOPTICALLY...ATTENTION IS COMPLETELY ON THE VIGOROUS SHORTWAVE TROUGH APPROACHING THE CENTRAL CALIFORNIA COAST. MODELS CONTINUE TO CONVERGE ON A COMMON SOLUTION FOR HANDLING THIS NEGATIVE TILT TROUGH...THOUGH THERE IS SOME SLIGHT TIMING SPREAD. MODEL CONSENSUS SHOWS THE TROUGH LIFTING INTO SOUTHWEST MN BY 00Z TUESDAY... NORTHWEST WI BY 12Z TUESDAY AND INTO ONTARIO BY 00Z WEDNESDAY. THE NAM REMAINS THE FASTEST OF THE CONSENSUS AND SEEMS A LITTLE SUSPICIOUS...SEEING THAT THE ECMWF HAS BEEN TRENDING SLOWER OVER THE PAST FEW DAYS. GIVEN THE VIGOROUS NATURE OF THE SHORTWAVE...WOULD SEEM A SLOWER AND DEEPER ROUTE WOULD BE THE WAY TO GO. REGARDING THE SURFACE LOW...FOLLOWING THE SAME PREMISES...BELIEVE THE SLOWER...DEEPER MORE WRAPPED SYSTEM PRESENTED BY THE CANADIAN/UKMET/ECMWF IS MORE LIKELY COMPARED TO THE NAM AND EVEN GFS. WPC HAS ALSO FAVORED THE SAME MODELS. PRECIPITATION-WISE...THE WARM CONVEYOR BELT DEVELOPING OFF TO OUR WEST LOOKS LIKELY TO MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA MONDAY MORNING. HARD TO SAY IF IT IS GOING TO PROGRESS INTO WISCONSIN PRIOR TO 18Z SEEING THE DRIER NAM/ECMWF LOOK. THEREFORE HAVE ONLY KEPT 20-40 PERCENT CHANCES 15-18Z. FOR THE AFTERNOON... THERE ARE SIGNS THAT THE WARM CONVEYOR PRECIPITATION MAY FALL APART AS IT MOVES INTO WISCONSIN...OR AT LEAST SHIFT NORTH INTO NORTHERN WISCONSIN....ESPECIALLY IN THE CANADIAN MODELS. GFS 305-310K ISENTROPIC LIFT PROGS SUGGEST THE SAME. THEREFORE...HAVE KEPT PRECIPITATION CHANCES MOSTLY IN THE 20-50 PERCENT RANGE OUTSIDE OF TAYLOR COUNTY WHERE PRECIPITATION IS MOST LIKELY. FOCUS THEN SHIFTS WEST ON WHETHER SHOWERS OR STORMS CAN FIRE ALONG A COLD FRONT / DRY LINE. THE GFS/CANADIAN/ECMWF/UKMET ALL INITIATE A SCT- BKN LINE OF SHOWERS NEAR I-35 TOWARDS 00Z. HOWEVER...THERE ARE TWO HUGE CONCERNS FOR THIS BEING A LINE OF SURFACE BASED CONVECTION... FIRST IS A FAIRLY STOUT CAP AROUND 700MB...SECOND ARE SURFACE DEWPOINTS WHICH MODELS TRY TO JUMP INTO THE LOW 50S. THE DEWPOINTS SEEM WAY OVERDONE. NOW CANT RULE OUT THE LINE OF SHOWERS FORMING MORE ABOVE THE CAP GIVEN FORCING FROM THE LEFT EXIT REGION ALONG WITH DPVA WITH THE TROUGH. SINCE THERE IS NO CAPE ABOVE THE CAP AND CONCERNED PRECIPITATION MAY NOT FORM AT ALL...REMOVED THE THUNDER CHANCE. THIS SHOULD ALSO REDUCE THE CONCERN OF ANY POSSIBLE SEVERE WEATHER. IF A LINE DOES FORM...IT LOOKS TO LIFT NORTHEAST THROUGH THE AREA DURING THE EVENING. PRECIPITATION LOOKS MORE LIKELY AFTER MIDNIGHT INTO TUESDAY MORNING OVER THE NORTHWEST HALF OF THE AREA AS THE COLD CONVEYOR BELT WRAPS IN. MOST OF THIS SHOULD BE A LIGHT SNOW WITH LITTLE ACCUMULATION. THIS SNOW WILL TAPER OFF TUESDAY AFTERNOON WITH THE DEPARTURE OF THE SYSTEM. TEMPERATURES...BEING IN THE WARM SECTOR ALL OF MONDAY WITH 9-13C 925MB READINGS...COMBINED WITH A WARMER START...THAT BREAK IN PRECIPITATION DURING THE AFTERNOON TO ALLOW FOR MIXING AND BREEZY SOUTH WINDS...HIGHS AGAIN SHOULD CLIMB INTO THE 60S AT MOST LOCATIONS. SNOWPACK HOLDS TAYLOR DOWN INTO THE 50S. READINGS THEN TANK MONDAY NIGHT AS THE COLD AIR WRAPS IN SOUTHWEST TO NORTHEAST. MUCH COOLER HIGHS FOR TUESDAY...THOUGH SOUTHERN AREAS SHOULD CLIMB INTO THE MID 40S AS THE COLD AIR DEPARTS. WINDS...SOUTHERLY 925MB WINDS INCREASE THROUGH MONDAY AS THE NEGATIVE TILT SHORTWAVE TROUGH APPROACHES. BY 21Z...MOST MODELS PROG THEM AROUND 40 KT WHILE 850MB WINDS APPROACH 50-55 KT...STRONGEST SOUTH OF I-90. DAYTIME MIXING SHOULD BE ENOUGH TO GIVE GUSTS OF 30- 35 KT...WITH A PRESSURE FALL CROSSING EAU CLAIRE GIVING SOME ISALLOBARIC HELP. AN ADVISORY MAY BE NEEDED IF NAM/GFS MOMENTUM TRANSFER PROGS ARE CORRECT...SUGGESTING 35-42 KT GUSTS. WITH THE COLD SIDE OF THE SYSTEM...925MB WINDS ARE A LITTLE LESS...CLOSER TO 35 KT FOR MONDAY NIGHT INTO TUE MORNING. THESE SHOULD EASILY MIX TO THE GROUND. MORE UNCERTAINTY EXISTS ON THE NEED FOR THE ADVISORY ON THE COLD SIDE. FOR TUESDAY NIGHT AND BEYOND... NEXT ITEM OF INTEREST IS THE TROUGH CURRENTLY SOUTH OF THE GULF OF ALASKA WHICH IS PROGGED TO END UP IN THE SOUTHWESTERN U.S. ON WEDNESDAY. UPPER RIDGING BUILDS DOWNSTREAM AHEAD OF THE TROUGH...BUT MOSTLY SOUTH OF THE FORECAST AREA. THIS KEEPS A COLDER LOW LEVEL AIRMASS IN PLACE. MEANWHILE...ISENTROPIC LIFT OF GULF OF MEXICO MOISTURE DOWNSTREAM OF THE UPPER TROUGH MAY SPREAD SOME PRECIPITATION INTO SOUTHERN PORTIONS OF THE FORECAST AREA PER 30.00Z GFS/GFS ENSEMBLES WEDNESDAY AND WEDNESDAY NIGHT. HOWEVER...30.00Z CANADIAN AND ECMWF KEEP THE PRECIPITATION SOUTH OF THE FORECAST AREA. HAVE SPLIT THE DIFFERENCE WHICH RESULTS IN MAINLY A DRY FORECAST NORTH OF I-90 TO SOME 20-50 PERCENT CHANCES SOUTH. THURSDAY COULD END UP BEING A MOSTLY DRY DAY. CONFIDENCE IS BEGINNING TO INCREASE FOR PRECIPITATION THURSDAY NIGHT THROUGH FRIDAY. THIS IS WHEN MODELS ARE IN GOOD AGREEMENT LIFTING THE TROUGH INTO THE FORECAST AREA. WINTER WEATHER ADVISORIES REMAIN POSSIBLE...MOSTLY DUE TO ACCUMULATING SNOW. DRIER WEATHER LOOKS TO MOVE IN FOR SATURDAY AS THE SYSTEM DEPARTS. BELOW NORMAL TEMPERATURES ARE LIKELY FOR MUCH OF TUESDAY NIGHT AND BEYOND GIVEN THE UPPER FLOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1237 PM CDT SUN MAR 30 2014 THE SURFACE PRESSURE GRADIENT WILL GRADUALLY RELAX AFTER 30.21Z AS SHORT WAVE TROUGH MOVES EAST INTO ONTARIO. AS IT DOES...THE SUSTAINED SOUTH WINDS WILL DROP INTO THE 10 TO 20 KNOTS RANGE AND THE WIND GUSTS IN THE 25 TO 30 KNOT RANGE WILL END. THE WINDS WILL DROP EVEN FURTHER INTO THE 5 TO 15 KNOT RANGE THIS EVENING AND REMAIN THERE THROUGH THE REST OF THE NIGHT. ON MONDAY MORNING...THE PRESSURE GRADIENT WILL ONCE AGAIN START TO TIGHTEN AS A STRENGHTENING LOW PRESSURE SYSTEM APPROACHES THE AREA FROM THE CENTRAL PLAINS. IF THE WE DO NOT MIX FAST ENOUGH DURING THE MORNING...THERE MAY BE A BRIEF PERIOD OF LOW LEVEL WIND SHEAR. A SCATTERED TO BROKEN 25K DECK WILL CONTINUE ACROSS THE AREA THROUGH 31.10Z AND THEN LOWER INTO THE 8 TO 15K RANGE. SHOWERS WILL MOVE INTO KRST AROUND 31.15Z AND THEN PERSIST THROUGH THE REMAINDER OF THE MORNING. THERE ARE SOME INDICATIONS THAT A MVFR DECK MAY MOVE INTO KRST TOWARD 31.18Z. SINCE THIS WAS AT THE END OF TAF PERIOD...DID NOT INCLUDE THEM AT THIS TIME. && .HYDROLOGY... ISSUED AT 319 AM CDT SUN MAR 30 2014 BASED ON GAUGE READINGS ALONG THE KICKAPOO FOR THOSE THAT STILL HAVE FLOOD WARNINGS...CONFIDENCE IS DECREASING THAT THEY WILL MAKE IT TO FLOOD. READSTOWN HAS STARTED FALLING...WHEN IT SHOULD STILL BE RISING. IF TRENDS CONTINUE...THE WARNINGS MAY BE CANCELLED. FOCUS THEN SHIFTS TO THE BLACK...BUFFALO AND TREMPEALEAU RIVERS. THE WARM UP OCCURRING TODAY AND PERSISTING INTO MONDAY EVENING... FEATURING HIGHS IN THE 55-65 RANGE AND LOWS IN THE 38-48 RANGE ALONG WITH BREEZY SOUTH WINDS...WILL HELP RAPIDLY MELT THE SNOW PACK THAT IS IN PLACE ALONG AND NORTH OF HIGHWAY 10. THIS RUNOFF WILL MAKE FLOODING A POSSIBILITY DURING THE WEEK. ON A POSITIVE NOTE...THE PRECIPITATION FROM THE SYSTEM MOVING THROUGH THE AREA MONDAY AND MONDAY NIGHT CONTINUES TO LOOK LESS AND LESS. AT THIS POINT...RAIN DOES NOT APPEAR TO BE MUCH OF A FACTOR TO THE RIVERS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FLOOD WATCH FROM LATE MONDAY NIGHT THROUGH THURSDAY MORNING FOR WIZ029-033-034. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...BOYNE HYDROLOGY...AJ