Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/13/14


AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
933 AM PST SAT JAN 11 2014 .DISCUSSION...AS OF 9:33 AM PST SATURDAY...A WEAK FRONTAL SYSTEM IS CURRENTLY MOVING ACROSS THE NORTH BAY WITH WEAK ECHOES SHOWING UP ON RADAR. NO MEASURABLE RAIN HAS BEEN PICKED UP THUS FAR AT ANY AREA GAUGES. THE FRONT WILL CONTINUE TO MOVE SOUTHWARD AND SOME MEASURABLE RAIN IS EXPECTED ACROSS THE NORTH BAY THROUGH EARLY AFTERNOON. THE 12Z NAM KEEPS ALL RAIN NORTH OF THE GOLDEN GATE...ALTHOUGH SOME SPRINKLES ARE POSSIBLE AS FAR SOUTH AS THE SANTA CRUZ MOUNTAINS. SHOWERS WILL QUICKLY END BY THIS EVENING WITH FOG FORMATION POSSIBLE OVERNIGHT. HIGH PRESSURE WILL BEGIN TO BUILD ON SUNDAY BUT TEMPERATURES ARE FORECAST TO STAY IN THE LOW TO MID 60S. HIGH PRESSURE IS PROGGED TO REBUILD STRONGLY OVER THE EASTERN PACIFIC AND OVER CALIFORNIA EARLY NEXT WEEK. TEMPERATURES WILL WARM TO ABOVE NORMAL FOR THIS TIME OF YEAR WITH HIGHS IN THE 60S AND 70S. SURFACE FLOW WILL BECOME OFFSHORE BRIEFLY MONDAY AND TUESDAY WHICH WILL ENHANCE THE WARMING AND DRYING EFFECTS. AT THIS TIME WIND ADVISORIES ARE NOT EXPECTED BUT THERE COULD BE ENHANCED FIRE WEATHER CONCERNS. MEDIUM RANGE MODELS KEEP THE RIDGE IN PLACE THROUGH THE FORECAST PERIOD AND FOR THE MOST PART BEYOND THROUGH TEN DAYS. && .AVIATION...AS OF 3:30 AM PST SATURDAY...LOW CONFIDENCE AND COMPLICATED FORECAST AS A MIX OF CLOUDS COVER THE REGION WITH A FORECAST FROPA LATER TODAY. THROUGH THE MORNING HOURS...MOSTLY VFR CONDITIONS WITH MID-HIGH LEVEL CLOUDS. SPEAKING OF HIGH CLOUDS THEY ARE MAKING IT DIFF TO SEE ANY STRATUS OR FOG ON THE SATELLITE. KSTS IS STILL REPORTING FOG. WILL KEEP FOG AT KSTS THROUGH THE MORNING HOURS. FOR SF BAY...DELAYED ANY CIGS/STRATUS UNTIL ALMOST 15Z. NOT EVEN THAT CONF STRATUS WILL ACTUALLY DEVELOP. A FRONT WILL SWEEP THROUGH 18-20Z WITH POSS -RA FOR KSTS AND VCSH AROUND SF BAY AND NO RAIN MENTION S OF SF BAY. CLEAR SKIES BEHIND THE FRONT WITH POSS PATCHY FOG TONIGHT. VICINITY OF KSFO...VFR TO START THEN DEV CIGS AROUND 15Z...PT SOUNDS AND HRRR MODEL REALLY MOISTEN THE LOW LEVELS. POSS CIGS AND VCSH LATER THIS AFTERNOON WITH THE FRONTAL PASSAGE. WINDS WILL INCREASE SLIGHTLY AS WELL. VFR CONDITIONS BEHIND THE FRONT. LOW CONF. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...PATCHY FOG LINGERS...BUT NONE BEING REPORTED AT KSNS/KMRY. WILL KEEP AN EYE ON THIS...OTHERWISE VFR CONDITIONS. POSS CIGS LATER TODAY AS THE FRONT APPROACHES. MEDIUM CONF. && .MARINE...AS OF 3:30 AM PST SATURDAY...NO REAL CHANGE IN THE FORECAST. MODELS STILL SEEM ON TRACK TO GENERATE BUILDING NORTHWEST SWELL OVER THE COASTAL WATERS LATER TODAY.NW SWELL 14 TO 18 FEET TONIGHT/SUNDAY WITH A PERIOD OF 15-16 SECONDS. THIS WILL TRANSLATE TO LARGER SURF ALONG THE BEACHES. GIVEN THE PERIOD AND SWELL HEIGHT SQUARED SEAS SEEM PLAUSIBLE. SWELLS QUICKLY SUBSIDE SUNDAY INTO MONDAY. && .FIRE WEATHER...AS OF 3:06 AM SATURDAY...SOME LIGHT RAIN TODAY IN THE NORTH BAY BUT IN GENERAL NOT EXPECTING WIDESPREAD WETTING RAINS (GREATER THAN A TENTH). NORTHEAST WINDS WILL DEVELOP ACROSS THE NORTH AND EAST BAY HILLS LATER SUNDAY NIGHT INTO MONDAY. EVENT LOOKS MODERATE IN STRENGTH WITH 925 MB WINDS IN THE 15-30 KT RANGE. RH VALUES WILL INITIALLY REMAIN HIGH...AROUND 40% WITH MORE NOTED DRYING OCCURRING LATER MONDAY AFTERNOON INTO TUESDAY. BY TUESDAY THE COMBINATION OF RECORD WARMTH...RECORD DRY FUELS AND DRY EASTERLY FLOW WILL AT THE VERY LEAST ELEVATE FIRE DANGER AND FIRE WEATHER CONCERNS EVEN THOUGH STRICT RED FLAG CRITERIA MAY NOT BE MET. SOUTHERN CALIFORNIA MAY BE DEALING WITH A SANTA ANA AND FIRE RESOURCES AT A MINIMUM GIVEN THE TIME OF YEAR. CURRENT RH...TEMP AND WIND TRENDS BY TUESDAY LOOK EERILY SIMILAR TO WHEN THE PFEIFFER FIRE STARTED LAST MONTH IN BIG SUR. && .CLIMATE...RECORD HIGH SUMMARY FOR NEXT WEEK: CITY MON 1/13/14 TUES 1/14/14 WEDS 1/15/14 ----------------------------------------------------------------- KENTFIELD 65 IN 1994 68 IN 1924 67 IN 1945 SAN RAFAEL 68 IN 2009 68 IN 1967 73 IN 1967 NAPA 81 IN 1924 72 IN 1924 70 IN 1966 SAN FRANCISCO 72 IN 2009 69 IN 2009 73 IN 2009 SFO AIRPORT 72 IN 2009 67 IN 1948 69 IN 1974 OAKLAND DT 78 IN 2009 70 IN 2009 75 IN 2009 OAKLAND AP 69 IN 2009 65 IN 2009 74 IN 2009 RICHMOND 69 IN 2012 66 IN 1959 72 IN 2009 LIVERMORE 73 IN 2009 68 IN 2009 75 IN 1920 MOUNTAIN VIEW 71 IN 2009 73 IN 2009 72 IN 2009 SAN JOSE 75 IN 2009 73 IN 2009 73 IN 2009 GILROY 73 IN 2009 74 IN 2009 72 IN 2012 MONTEREY 77 IN 2009 76 IN 2009 76 IN 2009 SANTA CRUZ 80 IN 1948 81 IN 1975 75 IN 2009 SALINAS 84 IN 2009 80 IN 2009 79 IN 2009 KING CITY 83 IN 2009 76 IN 1981 82 IN 2009 && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM FROM 3 PM && $$ PUBLIC FORECAST: SIMS AVIATION: MM MARINE: MM CLIMATE: RC/RWW 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
335 AM PST SAT JAN 11 2014 .DISCUSSION...AS OF 3:06 AM PST SATURDAY...A 975 MB LOW IS DEEPENING WEST OF SEATTLE BEFORE IT BEGINS TO FILL AND MOVE INLAND. A COLD FRONT EXTENDS SOUTHWARD FROM THE PARENT LOW AND WILL MOVE INTO FAR NORTHERN CALIFORNIA TODAY. LIGHT RAIN WAS REPORTED THE LAST FEW HOURS IN CRESCENT CITY AND ALL EYES WILL BE ON THIS PRECIP AS IT SLOWLY MAKES ITS WAY TOWARDS THE NORTH BAY BY LATE THIS MORNING OR EARLY AFTERNOON. MODEL CONSENSUS REMAINS GOOD WITH THE NAM/GFS AND EVEN THE RAP/HRRR SHORT RANGE MODELS SHOWING LIGHT RAINFALL BETWEEN 18-00Z THIS AFTERNOON. THE BEST CHANCE FOR SEEING SHOWERS WILL BE ACROSS SONOMA COUNTY BUT CANT COMPLETELY RULE OUT SHOWERS OR SPRINKLES FROM THE GOLDEN GATE DOWN TO THE SANTA CRUZ MOUNTAINS. THERE IS LITTLE OR NO COLD ADVECTION OR JET DYNAMICS THIS FAR SOUTH AND EXPECT NO PRECIP FOR THE SANTA CLARA VALLEY AND EAST BAY VALLEYS WITH SUCH A WEAK BOUNDARY. IN A NORMAL YEAR RAINFALL LIKE THIS WOULD HARDLY BE WORTH MENTIONING AS NORMAL RAINFALL PER DAY THIS TIME OF YEAR IS ALMOST 0.25 PER DAY IN THE NORTH BAY. PERHAPS VENADO WILL SEE UPWARDS OF A QUARTER INCH BUT ONLY EXPECT A FEW HUNDREDTHS FOR MOST REPORTING LOCATIONS FROM THE GOLDEN GATE NORTH WITH TRACE AMOUNTS SOUTH OF THE CITY. ANY LINGERING SHOWERS WILL QUICKLY END BY THIS EVENING WITH SOME LINGERING BOUNDARY LAYER MOISTURE ALLOWING SOME FOG TO FORM OVERNIGHT. HIGH PRESSURE WILL BEGIN TO BUILD SUNDAY BUT TEMPERATURES ARE FORECAST TO STAY IN THE LOW TO MID 60S. UNSEASONABLY STRONG HIGH PRESSURE STRENGTHENS MONDAY AND CONTINUES FOR MOST OF NEXT WEEK. 850 MB TEMPS ARE PROGGED TO REACH 16 CELSIUS BY TUESDAY MORNING WHICH WOULD REPRESENT THE 99TH PERCENTILE EVER RECORDED AT THE OAKLAND UPPER AIR SITE SHOULD IT VERIFY WITH DATA GOING BACK TO 1948. THERE WILL BE A PERIOD OF AT LEAST MODERATE OFFSHORE WINDS IN THE HILLS LATE SUNDAY NIGHT INTO MONDAY. STILL DOESN`T LOOK LIKE WIND ADVISORY CRITERIA WILL BE MET. FROM MONDAY AFTERNOON INTO TUESDAY SUSTAINED BUT LIGHT EASTERLY FLOW WILL DEVELOP OVER ALMOST ALL OF COASTAL CALIFORNIA WITH THE BOUNDARY LAYER BECOMING VERY DRY. RECORD OR NEAR RECORD HIGHS WILL BE POSSIBLE MONDAY THROUGH WEDS WITH TUESDAY LOOKING LIKE THE WARMEST DAY AT THIS TIME WITH LOCAL DOWN-SLOPE WARMING BEING MAXIMIZED. IRONICALLY THE BIGGEST IMPACT MAY END UP BEING FIRE WEATHER CONCERNS. PLEASE SEE FIRE WEATHER BELOW FOR MORE ON THAT. THE RIDGE WILL STAY IN PLACE AT LEAST THROUGH FRIDAY ALTHOUGH THE WINDS LOOK TO TURN ONSHORE BY THE END OF THE WEEK. THE MODELS HINT AT A FRONT BUMPING INTO THE RIDGE BY NEXT WEEKEND BUT ALSO SHOW ANY PRECIP FALLING APART BEFORE MOVING ONSHORE. AT THIS POINT WERE WATCHING THE EXTENDED 2 WEEK FORECAST FOR ANY HOPE OF A PATTERN CHANGE. THE 240 HOUR FORECAST FROM THE ECMWF SHOWS A STRONG 180 KT JET ACROSS THE PACIFIC WHILE THE 12-16 DAY GFS RUNS SHOW SOME ENERGY BREAKING THROUGH THE RIDGE. ITS GETTING HARD BUT WILL HAVE TO STAY PATIENT AND SEE IF THE PATTERN BREAKS AT ALL AFTER MLK WEEKEND. && .AVIATION...AS OF 3:30 AM PST SATURDAY...LOW CONFIDENCE AND COMPLICATED FORECAST AS A MIX OF CLOUDS COVER THE REGION WITH A FORECASTED FROPA LATER TODAY. THROUGH THE MORNING HOURS...MOSTLY VFR CONDITIONS WITH MID-HIGH LEVEL CLOUDS. SPEAKING OF HIGH CLOUDS THEY ARE MAKING IT DIFF TO SEE ANY STRATUS OR FOG ON THE SATELLITE. KSTS IS STILL REPORTING FOG. WILL KEEP FOG AT KSTS THROUGH THE MORNING HOURS. FOR SF BAY...DELAYED ANY CIGS/STRATUS UNTIL ALMOST 15Z. NOT EVEN THAT CONF STRATUS WILL ACTUALLY DEVELOP. A FRONT WILL SWEEP THROUGH 18-20Z WITH POSS -RA FOR KSTS AND VCSH AROUND SF BAY AND NO RAIN MENTION S OF SF BAY. CLEAR SKIES BEHIND THE FRONT WITH POSS PATCHY FOG TONIGHT. VICINITY OF KSFO...VFR TO START THEN DEV CIGS AROUND 15Z...PT SOUNDS AND HRRR MODEL REALLY MOISTEN THE LOW LEVELS. POSS CIGS AND VCSH LATER THIS AFTERNOON WITH THE FRONTAL PASSAGE. WINDS WILL INCREASE SLIGHTLY AS WELL. VFR CONDITIONS BEHIND THE FRONT. LOW CONF. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...PATCHY FOG LINGERS...BUT NONE BEING REPORTED AT KSNS/KMRY. WILL KEEP AN EYE ON THIS...OTHERWISE VFR CONDITIONS. POSS CIGS LATER TODAY AS THE FRONT APPROACHES. MEDIUM CONF. && .MARINE...AS OF 3:30 AM PST SATURDAY...NO REAL CHANGE IN THE FORECAST. MODELS STILL SEEM ON TRACK TO GENERATE BUILDING NORTHWEST SWELL OVER THE COASTAL WATERS LATER TODAY.NW SWELL 14 TO 18 FEET TONIGHT/SUNDAY WITH A PERIOD OF 15-16 SECONDS. THIS WILL TRANSLATE TO LARGER SURF ALONG THE BEACHES. GIVEN THE PERIOD AND SWELL HEIGHT SQUARED SEAS SEEM PLAUSIBLE. SWELLS QUICKLY SUBSIDE SUNDAY INTO MONDAY. && .FIRE WEATHER...AS OF 3:06 AM SATURDAY...SOME LIGHT RAIN TODAY IN THE NORTH BAY BUT IN GENERAL NOT EXPECTING WIDESPREAD WETTING RAINS (GREATER THAN A TENTH). NORTHEAST WINDS WILL DEVELOP ACROSS THE NORTH AND EAST BAY HILLS LATER SUNDAY NIGHT INTO MONDAY. EVENT LOOKS MODERATE IN STRENGTH WITH 925 MB WINDS IN THE 15-30 KT RANGE. RH VALUES WILL INITIALLY REMAIN HIGH...AROUND 40% WITH MORE NOTED DRYING OCCURRING LATER MONDAY AFTERNOON INTO TUESDAY. BY TUESDAY THE COMBINATION OF RECORD WARMTH...RECORD DRY FUELS AND DRY EASTERLY FLOW WILL AT THE VERY LEAST ELEVATE FIRE DANGER AND FIRE WEATHER CONCERNS EVEN THOUGH STRICT RED FLAG CRITERIA MAY NOT BE MET. SOUTHERN CALIFORNIA MAY BE DEALING WITH A SANTA ANA AND FIRE RESOURCES AT A MINIMUM GIVEN THE TIME OF YEAR. CURRENT RH...TEMP AND WIND TRENDS BY TUESDAY LOOK EERILY SIMILAR TO WHEN THE PFEIFFER FIRE STARTED LAST MONTH IN BIG SUR. && .CLIMATE...RECORD HIGH SUMMARY FOR NEXT WEEK: CITY MON 1/13/14 TUES 1/14/14 WEDS 1/15/14 ----------------------------------------------------------------- KENTFIELD 65 IN 1994 68 IN 1924 67 IN 1945 SAN RAFAEL 68 IN 2009 68 IN 1967 73 IN 1967 NAPA 81 IN 1924 72 IN 1924 70 IN 1966 SAN FRANCISCO 72 IN 2009 69 IN 2009 73 IN 2009 SFO AIRPORT 72 IN 2009 67 IN 1948 69 IN 1974 OAKLAND DT 78 IN 2009 70 IN 2009 75 IN 2009 OAKLAND AP 69 IN 2009 65 IN 2009 74 IN 2009 RICHMOND 69 IN 2012 66 IN 1959 72 IN 2009 LIVERMORE 73 IN 2009 68 IN 2009 75 IN 1920 MOUNTAIN VIEW 71 IN 2009 73 IN 2009 72 IN 2009 SAN JOSE 75 IN 2009 73 IN 2009 73 IN 2009 GILROY 73 IN 2009 74 IN 2009 72 IN 2012 MONTEREY 77 IN 2009 76 IN 2009 76 IN 2009 SANTA CRUZ 80 IN 1948 81 IN 1975 75 IN 2009 SALINAS 84 IN 2009 80 IN 2009 79 IN 2009 KING CITY 83 IN 2009 76 IN 1981 82 IN 2009 && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 3 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM FROM 3 PM && $$ PUBLIC FORECAST: RWW AVIATION: MM MARINE: MM CLIMATE: RC/RWW 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
441 PM MST SUN JAN 12 2014 .UPDATE... ISSUED AT 437 PM MST SUN JAN 12 2014 CONVECTIVE SHOWERS DIMINISHING ACROSS THE SAN JUANS...GRAND MESA AND VALLEY ZONES STILL UNDER WINTER HIGHLIGHTS. LATEST RAP AND HRRR MODELS SUGGEST ACTIVITY WILL CONTINUE TO DIMINISH OVER THE NEXT FEW HOURS. WEB CAMS AND SPOTTER REPORTS ALSO INDICATING ACTIVITY WINDING DOWN IN THESE AREAS. WITH SIGNIFICANT ACCUMULATIONS NO LONGER EXPECTED IN THESE AREAS OVERNIGHT...HAVE WENT AHEAD AND CANCELLED THE WARNINGS AND ADVISORIES. THE NORTHERN AND CENTRAL MOUNTAINS WILL CONTINUE TO INFLUENCED BY STRONG OROGRAPHICS AND SNOW SHOWERS...ALONG WITH WIDESPREAD BLOWING SNOW...SO HIGHLIGHTS IN THESE AREAS WILL BE CONTINUED FOR NOW. && .SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT) ISSUED AT 300 PM MST SUN JAN 12 2014 TROUGH AXIS POSITIONED OVER WRN COLORADO THIS AFTERNOON WILL MOVE DOWNSTREAM THIS EVENING. THE DYNAMICAL PORTION HAS MOVED OUT OF THE FORECAST AREA. THE COMBINATION OF POTENTIAL INSTABILITY AND STRONG OROGRAPHIC ACCOUNTS FOR THE SNOWFALL THIS AFTERNOON. MOUNTAIN WEB CAMS...MOST NOTABLY OVER VAIL PASS...SHOW EXTENDED PERIODS OF NEAR WHITEOUT CONDITIONS WITH SNOW PACKED ROADS. GUSTY WINDS (SOME AS HIGH AS 45 MPH) HAVE ACCOMPANIED THE CONVECTIVE SNOW BANDS THAT HAVE DEVELOPED. THE UNSETTLED ENVIRONMENT MAKES SIGNIFICANT SNOWFALL HIT AND MISS...BUT APPEARS THE HEAVIEST SNOWFALL HAS BEEN OVER THE GORE RANGE...ELK/WEST ELK MOUNTAINS...AND NWRN SAN JUAN MOUNTAINS...BUT NOT SO MUCH FOR THE GRAND MESA. UPSTREAM SHEAR AXIS ON THE BACK SIDE OF THE TROUGH WILL TRANSLATE ACROSS THE WESTERN SLOPE TONIGHT. HIGHER RESOLUTION MODELS...SUCH AS THE NAMDNG5 AND WRF MODELS...INDICATE THAT OCCASIONAL SNOW WILL NOT ABATE UNTIL THE PASSAGE OF THIS SHEAR AXIS (FOR THE ELK AND NWRN SAN JUAN MOUNTAINS). MOIST LAYER IS RELATIVELY SHALLOW...BUT IDEAL ICE CRYSTAL GROWTH REGIME IS AT MOUNTAIN TOP LEVEL...THIS LEADS TO SNOW RATIO VALUES AROUND 20/25 TO 1 AND PERHAPS HIGHER. COMBINED WITH THE GUSTY WINDS...BLOWING AND DRIFTING SNOW A SIGNIFICANT IMPACT ISSUE FOR EXPOSED LOCATIONS AND ABOVE TIMBERLINE. ONCE THE SHEAR AXIS CROSSES THE DIVIDE...SNOW WILL BE ENDING FOR THE ELKS/WEST ELKS AND NWRN SAN JUANS. OROGRAPHIC NORTHWEST FLOW WILL IMPACT THE PARK/GORE RANGES AND FLAT TOP MOUNTAINS THROUGH MONDAY. THE SNOW HAS MOMENTARILY LET UP OVER THE STEAMBOAT VICINITY...BUT BELIEVE SNOW WILL INCREASE LATE THIS AFTERNOON AS THE JET OVER UTAH SHIFTS OVER WRN COLORADO TONIGHT. HIGHER RESOLUTION MODELS STILL SHOW THE HAHNS PEAK TO STEAMBOAT SPRINGS AREAS AS THE BULLSEYE FOR SNOW TOTALS DURING THE NEXT 24 HOURS. OROGRAPHIC SNOW MAY CONTINUE THROUGH MONDAY NIGHT. FOR EASTERN UTAH AND WEST CENTRAL/SOUTHWEST COLORADO...CLEARING TREND OVER THE MOUNTAINS LATE TONIGHT...THEN MOSTLY CLEAR FOR THE REMAINDER OF THE PERIOD. WITH PRESSURE GRADIENT RELAXING...WINDS WILL TAPER OFF AFTER SUNSET TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 300 PM MST SUN JAN 12 2014 RESIDUAL MOISTURE REMAINS OVER NW COLORADO INTO TUESDAY. THE 700MB LEVEL REMAINS NEAR SATURATION AND AT AN EFFICIENT -10C. SO SCATTERED SNOW SHOWERS PRODUCING LIGHT ACCUMULATIONS ARE EXPECTED TUESDAY FOR THE PARK/GORE/ELK MTNS. ELSEWHERE NORTHWEST BREEZY WINDS WILL MIX INTO MOST VALLEYS KEEPING DAYTIME TEMPERATURES NEAR SEASONAL NORMS. THEN EXPECT DRY AND MILD WEATHER FOR THE REMAINDER OF THE WEEK. THE RIDGE... THAT HAS BEEN JUST OFF THE WEST COAST FOR OVER A MONTH...SHIFTS INLAND. THE AXIS SHIFTS OVER THE ROCKIES BY NEXT WEEKEND. THIS WILL BRING A STRONG WARMING TREND TO THE MOUNTAIN SLOPES WITH WEAK TO MODERATELY STRONG INVERSIONS FORMING IN THE VALLEYS ESPECIALLY VERNAL CRAIG AND GUNNISON. NO SIGNIFICANT PRECIPITATION EXPECTED FOR THE NEW WEEK. THE LATEST MEDIUM RANGE MODELS INDICATE THE RIDGE MAY BREAK DOWN BY NEXT SUNDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 300 PM MST SUN JAN 12 2014 COLDER UNSETTLED AIR CONTINUES TO POUR OVER THE FORECAST AREA INTO TUESDAY. GUSTY NW WINDS WILL CONTINUE THIS AFTERNOON AT ALL TAF SITES. TONIGHT VALLEY WINDS WILL BECOME LIGHT BUT MECHANICAL TURBULENCE WILL CONTINUE OVER THE MOUNTAINS. SNOWFALL WILL BECOME MORE SCATTERED IN COVERAGE THROUGH THE NIGHT AND INTO MONDAY. FOR KHDN...KSBS...KEGE...KASE EXPECT PERIODS OF CIGS BLO 020 VSBY BLO 3SM IN SN BR. AFT 15Z CONDITIONS WILL IMPROVE TO PERIODS OF CIGS 020-040 VIS 3-5SM IN SN BR. MTN OBSCURATIONS WILL BE COMMON TONIGHT THROUGH MONDAY MORNING. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT COZ012. WINTER STORM WARNING UNTIL 5 PM MST MONDAY COZ004-010-013. WINTER STORM WARNING UNTIL 3 AM MST MONDAY COZ005. UT...NONE. && $$ UPDATE...JDC SHORT TERM...PF LONG TERM...JOE AVIATION...JOE
AREA FORECAST DISCUSSION
NWS DENVER CO
ISSUED BY NATIONAL WEATHER SERVICE PUEBLO CO 1011 AM MST SAT JAN 11 2014 .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON EXCEPT 00Z MON FOR KDEN) ISSUED AT 959 AM MST SAT JAN 11 2014 3 TAF SITES...KBJC...KAPA AND KDEN ARE EXPECTED TO BE VFR NEXT 24-30 HOURS. MAIN CONCERN DURING THIS PERIOD WILL BE WINDS. IN THE NEXT 6 HOURS OR SO...LATEST GUIDANCE CONTINUES TO INDICATE THAT WINDS AT KDEN AND KAPA SHOULD REMAIN MAINLY SOUTHWESTERLY TO SOUTHERLY AT 10 TO 15 KNTS. LATEST HRRR HAS WEAK SFC LOW IN VICINITY OF DIA...SO WINDS MAY BE A BIT TRICKY LATER THIS AFTERNOON. IF ATMOS MIXES OUT...THEN DIA MAY SHIFT TO A MORE WEST- NORTHWESTERLY DIRECTION AND COULD BECOME GUSTY FOR AWHILE. KBJC WILL REMAIN GUSTY FROM THE WNW THROUGH TONIGHT. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA TOMORROW MORNING AND EXPECT GUSTY NW WINDS AT ALL TAF SITES BY LATE TOMORROW MORNING AND LASTING THROUGH THE AFTERNOON. /HODANISH && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 6 PM MST THIS EVENING FOR COZ035-036. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ031- 033-034. WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR COZ031-033-034. && $$ AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS ALBANY NY
440 PM EST SAT JAN 11 2014 .SYNOPSIS... A STRONG COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING. RAIN WILL END FROM WEST TO EAST WITH COOLER TEMPERATURES RETURNING OVERNIGHT INTO SUNDAY. WEST TO NORTHWEST WINDS WILL INCREASE DURING SUNDAY WITH OCCASIONAL STRONGER GUSTS. A RIDGE OF HIGH PRESSURE SLIDES ACROSS SUNDAY NIGHT WITH TRANQUIL WEATHER CONDITIONS. A SOUTHERLY FLOW OF AIR ARRIVES MONDAY WITH MILD TEMPERATURES ALONG WITH AN INCREASE IN CLOUD COVER. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... FLOOD WATCH REMAINS IN EFFECT... INITIAL LINE OF EMBEDDED CONVECTION WITH CG/S PER THE NLDN WERE NOW EAST OF OUR NEW ENGLAND COUNTIES. ANOTHER LINE OF EMBEDDED CONVECTION WAS EVOLVING ACROSS EASTERN PA/WESTERN NJ INTO PORTIONS OF THE CATSKILLS. PER THE HRRR EXPERIENTIAL REFLECTIVITIES...THIS LINE MAY FILL IN A BIT MORE AS IT MOVES ACROSS THE HUDSON RIVER VALLEY FROM THE CAPITAL REGION AND POINTS SOUTHWARD. EARLIER THIS AFTERNOON...PRESSURE FALLS WERE QUITE IMPRESSIVE WITH 8-10MBS/3HRS OBSERVED IN METARS AND MSAS ANALYSIS AS A MESOLOW PROGRESSED ACROSS EASTERN NY. EXPECTATIONS ARE FOR THE COLD FRONT TO MOVE EAST OF THE NY COUNTIES AROUND 03Z SUNDAY AND WESTERN NEW ENGLAND COUNTIES AROUND 05Z SUNDAY. WE WILL TAPER OFF POPS FROM WEST TO EAST DURING THIS TIME FRAME. THEN WE SHIFT GEARS TOWARD LAKE EFFECT ACTIVITY INCREASING DOWNWIND OF LAKE ONTARIO. H850 TEMPS DROP BACK TOWARD TOWARD -6C/-7C OVERNIGHT OVER THE RELATIVELY OPEN WATERS WHERE AVERAGE WATER TEMPS WERE AROUND 3C PER THE GLERL OBSERVATIONS. THIS WOULD SUGGEST THE DELTA T/S WOULD REMAIN LESS THAN FAVORABLE EVEN WITH UPSTREAM LAKE CONNECTION FROM EITHER HURON OR GEORGIAN BAY. SO WE WILL HOLD POPS INTO THE CHC-SCT THRESHOLDS WITH A RAIN/SNOW SHOWER MIXTURE TRANSITIONING TO ALL SNOW SHOWERS OVERNIGHT. THE UPPER TROUGH TOO WILL BE APPROACHING THE REGION OVERNIGHT WHICH SHOULD KEEP CLOUDS IN PLACE AND MAINLY TERRAIN BASED CHC TO SCT RA/SN SHOWERS. OVERNIGHT LOWS PER THE MOS GUIDANCE LOOK RATHER CLOSE AND PER THE UPSTREAM OVERNIGHT LOW OBSERVATIONS...WE WILL SHADE ON THE SLIGHTLY WARMER SIDE OF THE GUIDANCE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... SUNDAY... UPPER TROUGH AXIS SLIDES ACROSS THE REGION IN THE MORNING WHERE CLOUDS AND SOME SHOWER ACTIVITY /MAINLY ACROSS THE TERRAIN AND NEAR LAKE ONTARIO/ WILL BE MOST PREVALENT. AS THIS UPPER TROUGH SLIDES EAST...INCREASING SUBSIDENCE AND GRADUAL IMPROVEMENTS TO THE SKY FORECAST ARE EXPECTED. HOWEVER...WITH THE INCREASE IN SOME SUNSHINE...THE MIXING LAYER HEIGHT TAPS INTO 30-40KT WINDS. FURTHERMORE...POTENTIAL FOR SOME FUNNELING DOWN THE MOHAWK MAY INCREASE THOSE MAGNITUDES. PER COLLABORATION...WE WILL HOLD OFF ON WIND ADVISORIES AT THIS TIME AS CONFIDENCE IS JUST BELOW THRESHOLDS BUT WILL MENTION IN THE HWO. PER THOSE MIXING LAYER HEIGHTS...WE WILL FAVOR HIGH TEMPERATURES INTO THE 40S FOR THE VALLEY LOCATIONS AND 30S FOR THE HIGHER TERRAIN. SUNDAY NIGHT... RIDGE AXIS SLIDES ACROSS FOR TRANQUIL CONDITIONS AND ANY LAKE RESPONSE QUICKLY DISSIPATING. AS WARMER AIR ADVECTS IN ALOFT...AND THE LOSS OF SNOW PACK...WE WILL HOLD OVERNIGHT LOWS MAINLY INTO THE MIDDLE 20S UNDER A PTCLOUDY-MOCLR SKY. MONDAY INTO MONDAY NIGHT... UPPER TROUGH AXIS MOVING INLAND ACROSS THE PACIFIC NORTHWEST WILL ADVANCE EAST ACROSS THE NORTHERN PLAINS ON MONDAY. THE DEPARTURE OF THE RIDGE AXIS AND THE APPROACH OF THIS TROUGH AXIS AND DEVELOPING COLD FRONT WILL INCREASE THE SOUTHERLY WIND FOR A RELATIVELY MILD DAY UNDER PARTIAL SUNSHINE. NCEP MODEL SUITE IS A LITTLE SLOWER SO WE WILL CONTINUE TO WITHHOLD THE MENTION OF PRECIP UNTIL MONDAY NIGHT. MOISTURE TRANSPORT IS EXPECTED/PROGGED TO INCREASE FROM THE SOUTH MONDAY EVENING WITH PRECIPITATION DEVELOPING ALONG THE FRONT. THERMAL PROFILES OFFER A MIXTURE OF RAIN/SNOW SHOWERS WITH MAINLY LIQUID TO START THEN A TRANSITION TO A WINTRY MIX OF RA/SN OVERNIGHT. MOS GUIDANCE SUGGESTS OVERNIGHT LOWS DROPPING TOWARD THE FREEZING MARK BY SUNRISE BUT WITH A LITTLE SLOWER ARRIVAL ALONG WITH CLOUD COVER AND MILDER THERMAL PROFILES...WE WILL KEEP OVERNIGHT LOWS A BIT MILDER. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE EXTENDED FORECAST PERIOD WILL INVOLVE A "WAVY" PATTERN AS SERIES OF DISTURBANCES LOOK TO ULTIMATELY CARVE OUT A TROUGH IN THE NORTHEASTERN CONUS. THE NORTHERN JETSTREAM WILL BE THE DOMINATING ONE. WHILE IT WILL BE SOMEWHAT UNSETTLED...MOISTURE WILL GENERALLY BE LIMITED WITH EACH OF THE SYSTEMS AS THEY MOVE FAIRLY QUICKLY. TEMPERATURES WILL START OFF ABOVE NORMAL BUT TREND TO A LITTLE BELOW NORMAL BY NEXT WEEKEND. ON TUESDAY...INITIAL VORTICITY FROM A DIGGING MID LATITUDE TROUGH OVER THE OHIO VALLEY...COULD SPAWN A SURFACE LOW OVER THE SOUTHEAST OR LOW MID ATLANTIC REGION. INTERESTING...THE GFS WAS THE FIRST TO REFLECT THIS IDEA...BUT HAS NOW BACKED OFF...KEEPING ANY WEAK SURFACE WAVE WELL TO THE EAST. HOWEVER SINCE THE CANADIAN/ECMWF AND WPC SOLUTIONS INDICATED IT...WE WENT WITH THE MAJORITY OF THIS SOLUTION. WHILE ALL MODELS INDICATED THE MAJORITY OF PRECIPITATION MISSES OUR REGION...IT WILL BE A CLOSE CALL...ESPECIALLY OVER OUR SOUTHEASTERN ZONES SO WILL CONTINUE WITH 30-50 POPS ON THAT DAY (HIGHEST SOUTHEAST). HIGH TEMPERATURES ON TUESDAY LOOK TO BE IN THE LOWER 30S ACROSS THE ADIRONDACKS...35 TO 40 REMAINING AREAS TO THE NORTH OF THE CAPITAL REGION AND BERKSHIRES...LOWER 40S CAPITAL REGION...MID TO UPPER 40S MID HUDSON VALLEY AND LITCHFIELD COUNTY. THIS WILL MEAN MUCH OF THE PRECIPITATION THAT WOULD FALL (ASSUMING IT WILL BE LIGHT) SHOULD BE RAIN IN THE VALLEYS...RAIN AND A WET SNOW MIX ACROSS THE HIGHER TERRAIN. TUESDAY NIGHT...LOOKS LIKE A BRIEF AREA OF SUBSIDENCE WILL OCCUR AS THE FIRST SURFACE SYSTEM DEPARTS AND ANOTHER APPROACHES FROM THE WEST. WILL KEEP SLIGHT POPS IN. OVERNIGHT LOWS WILL BE IN THE 20S. WEDNESDAY AND WEDNESDAY NIGHT....WHILE THE FIRST SURFACE LOW ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE TO OUR EAST...ALL MODELS (EXCEPT THE CANADIAN) DEVELOP ANOTHER LOW ON WEDNESDAY NEAR OUR REGION...AS THE THE MAIN MID LEVEL TROUGH SLOWLY WORKS INTO THE REGION...WITH THE ECMWF ACTUALLY CUTTING THIS FEATURE OFF. WE INCREASE POPS UP TO 30 PERCENT AND 40 PERCENT BY WEDNESDAY NIGHT. AGAIN PRECIPITATION LOOKS LIGHT. HIGH TEMPERATURES WILL BE A LITTLE COOLER ON WEDNESDAY...AROUND 30 ACROSS THE ADIRONDACK PARK...MID OR UPPER 30S ACROSS MOST OF THE REMAINDER OF THE REGION...EXCEPT AROUND 40 IN THE MID HUDSON VALLEY AND LOWER LITCHFIELD. AGAIN...THESE TEMPERATURES WILL LIKELY MEAN ANY LIGHT PRECIPITATION WOULD FALL MAINLY AS RAIN IN THE VALLEYS...AND WET SNOW...POSSIBLY MIXED WITH A LITTLE RAIN OVER THE HIGHER TERRAIN...EXCEPT ALL SNOW ACROSS THE ADIRONDACKS. WEDNESDAY NIGHT WITH COLDER TEMPERATURES EXPECTED BACK DOWN IN THE 20S (TEENS ADIRONDACKS) ANY PRECIPITATION WOULD FALL AS SNOW OR SNOW SHOWERS. THURSDAY AND THURSDAY NIGHT...THE MID LEVEL TROUGH SHOULD BE TO OUR EAST...AND AGAIN SOME SUBSIDENCE AND POSSIBLE RIDGING LOOKS TO DRY US OUT WITH PARTIAL SUNSHINE. ONLY PLACES TO HAVE POPS ON THURSDAY WILL BE THE ELEVATED TERRAIN DUE TO POSSIBLE RESIDUAL LAKE ENHANCED UPSLOPE SHOWERS OF SNOW. TEMPERATURES LOOK TO BE SEASONABLE...WITH HIGHS RANGING FROM THE UPPER 20S ACROSS OUR NORTHWESTER AREAS...LOWER 30S CAPITAL REGION...MID OR UPPER 30S MID HUDSON VALLEY AND LOWER LITCHFIELD. OVERNIGHT LOWS WILL BE IN THE 20S. THEN ON FRIDAY...AN EVEN STRONGER DIGGING TROUGH APPROACHES WITH FROM THE GREAT LAKES...INCREASES CHANCES OF PRECIPITATION ONCE MORE. A SOUTHERLY BREEZE AHEAD OF AN APPROACHING COLD FRONT WILL BUMP TEMPERATURES BACK UP TO A LITTLE ABOVE NORMAL...RANGING FROM AROUND 30 NORTHWEST TO AROUND 40 SOUTHEAST. PRECIPITATION WILL BE IN THE FORM OF VALLEY RAIN SHOWERS...MOUNTAIN SNOW OR A RAIN SNOW MIX. ARCTIC AIR WILL FOLLOW BEHIND THIS FEATURE...LOWERING TEMPERATURES TO MAINLY THE TEENS FRIDAY NIGHT AND HOLDING THEM MAINLY IN THE 20S ON SATURDAY. ASIDE FROM SOME POSSIBLE LAKE ENHANCED SNOW SHOWERS ACROSS THE ADIRONDACKS/MOHAWK VALLEY AND SOUTHERN GREENS....OTHER AREAS LOOK DRY BUT BRISK. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... MVFR/IFR CONDITIONS WILL CONTINUE THROUGH THE EVENING PEAK AS A COLD FRONT APPROACHES FROM THE WEST...AND A MOIST SOUTHERLY FLOW WILL CONTINUES AHEAD OF THE FRONT. OCCASIONALLY...CIGS AND OR VSBYS COULD SLIP TO LIFR AS THEY HAVE AT KGFL AND KALB. WILL CONTINUE WITH LLWS ALTHOUGH OUR VAD WIND PROFILE INDICATED SLIGHTLY LESS STRONG WIND AROUND THE 2000 FOOT LEVEL (CLOSER TO 40KTS AS OPPOSED TO 60 KTS). SO FAR...THERE HAVE BEEN OFFICIALLY NO REPORTS OF LLWS IN THE PIREPS. IF THIS TREND CONTINUES...WILL REMOVE ANY LLWS WITH THE OFFICIAL EVENING ISSUANCES OF THE TAFS. ONCE THE COLD FRONT PASSES THROUGH THE REGION AFTER 00Z SUNDAY...A LEFTOVER VCSH OR -SHRA IS POSSIBLE BEHIND THE FRONT THROUGH 06Z SUNDAY. WINDS WILL SHIFT TO WESTERN TO WEST NORTHWESTERLY 5-10 KTS BEHIND THE FRONT AND IN PARTICULAR...GUSTS STILL ABOVE 20 KTS POSSIBLE ESPECIALLY AT KALB/KPSF. OTHERWISE...CONDITIONS SHOULD IMPROVE TO VFR CONDITIONS AFTER 06Z SUNDAY THROUGH THE END OF THE TAF PERIOD WITH THE END OF THE PRECIPITATION. OUTLOOK... SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. MONDAY: LOW OPERATIONAL IMPACT.BREEZY NO SIG WX. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN. WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN. && .HYDROLOGY... THE FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY...WITH THE PRIMARY THREAT ICE JAM FLOODING. RIVERS ARE RESPONDING TO THE RAINFALL ACROSS THE REGION WITH THE CATSKILLS BEING THE CENTER OF THE HIGHER RAINFALL TOTALS PER MESONET OBSERVATIONS. IN ADDITION...TEMPERATURES ARE QUITE MILD WITH MAINLY 50S AND NOW SOME LOWER 60S FOR THE MID HUDSON VALLEY...NW CT...BERKSHIRES...TACONICS AND WESTERN GREENS /DOWNSLOPING/. LATEST NERFC QPF SUGGESTS THE BEST QPF WILL OCCUR BEFORE 00Z WITH AROUND ONE INCH MAINLY INTO THE TERRAIN SOUTH AND EAST OF ALBANY. FURTHERMORE...ICE JAMS REMAIN THE GREATEST THREAT AS WARMER TEMPERATURES AND RAINFALL WILL ALLOW FOR ICE TO MOVE. THE NEXT SEVERAL DAYS WE WILL EXPERIENCE A DIURNAL RANGE OF ABOVE FREEZING TEMPERATURES DURING THE DAYLIGHT HOURS AND AT OR BELOW FREEZING AT NIGHT. THIS WILL LIKELY RESULT IN ICE MOVEMENT/MELTING WHICH COULD ALSO RESULT IN ISOLATED AREAS OF ICE JAMS. 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 THROUGH SUNDAY AFTERNOON FOR CTZ001-013. NY...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR NYZ032-033-038>043- 047>054-058>061-063>066-082>084. MA...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR MAZ001-025. VT...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR VTZ013>015. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...HWJIV AVIATION...HWJIV/LFM/WASULA HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
420 PM EST SAT JAN 11 2014 .SYNOPSIS... A STRONG COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING. RAIN WILL END FROM WEST TO EAST WITH COOLER TEMPERATURES RETURNING OVERNIGHT INTO SUNDAY. WEST TO NORTHWEST WINDS WILL INCREASE DURING SUNDAY WITH OCCASIONAL STRONGER GUSTS. A RIDGE OF HIGH PRESSURE SLIDES ACROSS SUNDAY NIGHT WITH TRANQUIL WEATHER CONDITIONS. A SOUTHERLY FLOW OF AIR ARRIVES MONDAY WITH MILD TEMPERATURES ALONG WITH AN INCREASE IN CLOUD COVER. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... ...FLOOD WATCH REMAINS IN EFFECT... INITIAL LINE OF EMBEDDED CONVECTION WITH CG/S PER THE NLDN WERE NOW EAST OF OUR NEW ENGLAND COUNTIES. ANOTHER LINE OF EMBEDDED CONVECTION WAS EVOLVING ACROSS EASTERN PA/WESTERN NJ INTO PORTIONS OF THE CATSKILLS. PER THE HRRR EXPERIENTIAL REFLECTIVITIES...THIS LINE MAY FILL IN A BIT MORE AS IT MOVES ACROSS THE HUDSON RIVER VALLEY FROM THE CAPITAL REGION AND POINTS SOUTHWARD. EARLIER THIS AFTERNOON...PRESSURE FALLS WERE QUITE IMPRESSIVE WITH 8-10MBS/3HRS OBSERVED IN METARS AND MSAS ANALYSIS AS A MESOLOW PROGRESSED ACROSS EASTERN NY. EXPECTATIONS ARE FOR THE COLD FRONT TO MOVE EAST OF THE NY COUNTIES AROUND 03Z SUNDAY AND WESTERN NEW ENGLAND COUNTIES AROUND 05Z SUNDAY. WE WILL TAPER OFF POPS FROM WEST TO EAST DURING THIS TIME FRAME. THEN WE SHIFT GEARS TOWARD LAKE EFFECT ACTIVITY INCREASING DOWNWIND OF LAKE ONTARIO. H850 TEMPS DROP BACK TOWARD TOWARD -6C/-7C OVERNIGHT OVER THE RELATIVELY OPEN WATERS WHERE AVERAGE WATER TEMPS WERE AROUND 3C PER THE GLERL OBSERVATIONS. THIS WOULD SUGGEST THE DELTA T/S WOULD REMAIN LESS THAN FAVORABLE EVEN WITH UPSTREAM LAKE CONNECTION FROM EITHER HURON OR GEORGIAN BAY. SO WE WILL HOLD POPS INTO THE CHC-SCT THRESHOLDS WITH A RAIN/SNOW SHOWER MIXTURE TRANSITIONING TO ALL SNOW SHOWERS OVERNIGHT. THE UPPER TROUGH TOO WILL BE APPROACHING THE REGION OVERNIGHT WHICH SHOULD KEEP CLOUDS IN PLACE AND MAINLY TERRAIN BASED CHC TO SCT RA/SN SHOWERS. OVERNIGHT LOWS PER THE MOS GUIDANCE LOOK RATHER CLOSE AND PER THE UPSTREAM OVERNIGHT LOW OBSERVATIONS...WE WILL SHADE ON THE SLIGHTLY WARMER SIDE OF THE GUIDANCE. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... SUNDAY... UPPER TROUGH AXIS SLIDES ACROSS THE REGION IN THE MORNING WHERE CLOUDS AND SOME SHOWER ACTIVITY /MAINLY ACROSS THE TERRAIN AND NEAR LAKE ONTARIO/ WILL BE MOST PREVALENT. AS THIS UPPER TROUGH SLIDES EAST...INCREASING SUBSIDENCE AND GRADUAL IMPROVEMENTS TO THE SKY FORECAST ARE EXPECTED. HOWEVER...WITH THE INCREASE IN SOME SUNSHINE...THE MIXING LAYER HEIGHT TAPS INTO 30-40KT WINDS. FURTHERMORE...POTENTIAL FOR SOME FUNNELING DOWN THE MOHAWK MAY INCREASE THOSE MAGNITUDES. PER COLLABORATION...WE WILL HOLD OFF ON WIND ADVISORIES AT THIS TIME AS CONFIDENCE IS JUST BELOW THRESHOLDS BUT WILL MENTION IN THE HWO. PER THOSE MIXING LAYER HEIGHTS...WE WILL FAVOR HIGH TEMPERATURES INTO THE 40S FOR THE VALLEY LOCATIONS AND 30S FOR THE HIGHER TERRAIN. SUNDAY NIGHT... RIDGE AXIS SLIDES ACROSS FOR TRANQUIL CONDITIONS AND ANY LAKE RESPONSE QUICKLY DISSIPATING. AS WARMER AIR ADVECTS IN ALOFT...AND THE LOSS OF SNOW PACK...WE WILL HOLD OVERNIGHT LOWS MAINLY INTO THE MIDDLE 20S UNDER A PTCLOUDY-MOCLR SKY. MONDAY INTO MONDAY NIGHT... UPPER TROUGH AXIS MOVING INLAND ACROSS THE PACIFIC NORTHWEST WILL ADVANCE EAST ACROSS THE NORTHERN PLAINS ON MONDAY. THE DEPARTURE OF THE RIDGE AXIS AND THE APPROACH OF THIS TROUGH AXIS AND DEVELOPING COLD FRONT WILL INCREASE THE SOUTHERLY WIND FOR A RELATIVELY MILD DAY UNDER PARTIAL SUNSHINE. NCEP MODEL SUITE IS A LITTLE SLOWER SO WE WILL CONTINUE TO WITHHOLD THE MENTION OF PRECIP UNTIL MONDAY NIGHT. MOISTURE TRANSPORT IS EXPECTED/PROGED TO INCREASE FROM THE SOUTH MONDAY EVENING WITH PRECIPITATION DEVELOPING ALONG THE FRONT. THERMAL PROFILES OFFER A MIXTURE OF RAIN/SNOW SHOWERS WITH MAINLY LIQUID TO START THEN A TRANSITION TO A WINTRY MIX OF RA/SN OVERNIGHT. MOS GUIDANCE SUGGESTS OVERNIGHT LOWS DROPPING TOWARD THE FREEZING MARK BY SUNRISE BUT WITH A LITTLE SLOWER ARRIVAL ALONG WITH CLOUD COVER AND MILDER THERMAL PROFILES...WE WILL KEEP OVERNIGHT LOWS A BIT MILDER. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE EXTENDED FORECAST PERIOD WILL INVOLVE A "WAVY" PATTERN AS SERIES OF DISTURBANCES LOOK TO ULTIMATELY CARVE OUT A TROUGH IN THE NORTHEASTERN CONUS. THE NORTHERN JETSTREAM WILL BE THE DOMINATING ONE. WHILE IT WILL BE SOMEWHAT UNSETTLED...MOISTURE WILL GENERALLY BE LIMITED WITH EACH OF THE SYSTEMS AS THEY MOVE FAIRLY QUICKLY. TEMPERATURES WILL START OFF ABOVE NORMAL BUT TREND TO A LITTLE BELOW NORMAL BY NEXT WEEKEND. ON TUESDAY...INITIAL VORTICITY FROM A DIGGING MID LATITUDE TROUGH OVER THE OHIO VALLEY...COULD SPAWN A SURFACE LOW OVER THE SOUTHEAST OR LOW MID ATLANTIC REGION. INTERESTING...THE GFS WAS THE FIRST TO REFLECT THIS IDEA...BUT HAS NOW BACKED OFF...KEEPING ANY WEAK SURFACE WAVE WELL TO THE EAST. HOWEVER SINCE THE CANADIAN/ECMWF AND WPC SOLUTIONS INDICATED IT...WE WENT WITH THE MAJORITY OF THIS SOLUTION. WHILE ALL MODELS INDICATED THE MAJORITY OF PRECIPITATION MISSES OUR REGION...IT WILL BE A CLOSE CALL...ESPECIALLY OVER OUR SOUTHEASTERN ZONES SO WILL CONTINUE WITH 30-50 POPS ON THAT DAY (HIGHEST SOUTHEAST). HIGH TEMPERATURES ON TUESDAY LOOK TO BE IN THE LOWER 30S ACROSS THE ADIRONDACKS...35 TO 40 REMAINING AREAS TO THE NORTH OF THE CAPITAL REGION AND BERKSHIRES...LOWER 40S CAPITAL REGION...MID TO UPPER 40S MID HUDSON VALLEY AND LITCHFIELD COUNTY. THIS WILL MEAN MUCH OF THE PRECIPITATION THAT WOULD FALL (ASSUMING IT WILL BE LIGHT) SHOULD BE RAIN IN THE VALLEYS...RAIN AND A WET SNOW MIX ACROSS THE HIGHER TERRAIN. TUESDAY NIGHT...LOOKS LIKE A BRIEF AREA OF SUBSIDENCE WILL OCCUR AS THE FIRST SURFACE SYSTEM DEPARTS AND ANOTHER APPROACHES FROM THE WEST. WILL KEEP SLIGHT POPS IN. OVERNIGHT LOWS WILL BE IN THE 20S. WEDNESDAY AND WEDNESDAY NIGHT....WHILE THE FIRST SURFACE LOW ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE TO OUR EAST...ALL MODELS (EXCEPT THE CANADIAN) DEVELOP ANOTHER LOW ON WEDNESDAY NEAR OUR REGION...AS THE THE MAIN MID LEVEL TROUGH SLOWLY WORKS INTO THE REGION...WITH THE ECMWF ACTUALLY CUTTING THIS FEATURE OFF. WE INCREASE POPS UP TO 30 PERCENT AND 40 PERCENT BY WEDNESDAY NIGHT. AGAIN PRECIPITATION LOOKS LIGHT. HIGH TEMPERATURES WILL BE A LITTLE COOLER ON WEDNESDAY...AROUND 30 ACROSS THE ADIRONDACK PARK...MID OR UPPER 30S ACROSS MOST OF THE REMAINDER OF THE REGION...EXCEPT AROUND 40 IN THE MID HUDSON VALLEY AND LOWER LITCHFIELD. AGAIN...THESE TEMPERATURES WILL LIKELY MEAN ANY LIGHT PRECIPITATION WOULD FALL MAINLY AS RAIN IN THE VALLEYS...AND WET SNOW...POSSIBLY MIXED WITH A LITTLE RAIN OVER THE HIGHER TERRAIN...EXCEPT ALL SNOW ACROSS THE ADIRONDACKS. WEDNESDAY NIGHT WITH COLDER TEMPERATURES EXPECTED BACK DOWN IN THE 20S (TEENS ADIRONDACKS) ANY PRECIPITATION WOULD FALL AS SNOW OR SNOW SHOWERS. THURSDAY AND THURSDAY NIGHT...THE MID LEVEL TROUGH SHOULD BE TO OUR EAST...AND AGAIN SOME SUBSIDENCE AND POSSIBLE RIDGING LOOKS TO DRY US OUT WITH PARTIAL SUNSHINE. ONLY PLACES TO HAVE POPS ON THURSDAY WILL BE THE ELEVATED TERRAIN DUE TO POSSIBLE RESIDUAL LAKE ENHANCED UPSLOPE SHOWERS OF SNOW. TEMPERATURES LOOK TO BE SEASONABLE...WITH HIGHS RANGING FROM THE UPPER 20S ACROSS OUR NORTHWESTER AREAS...LOWER 30S CAPITAL REGION...MID OR UPPER 30S MID HUDSON VALLEY AND LOWER LITCHFIELD. OVERNIGHT LOWS WILL BE IN THE 20S. THEN ON FRIDAY...AN EVEN STRONGER DIGGING TROUGH APPROACHES WITH FROM THE GREAT LAKES...INCREASES CHANCES OF PRECIPITATION ONCE MORE. A SOUTHERLY BREEZE AHEAD OF AN APPROACHING COLD FRONT WILL BUMP TEMPERATURES BACK UP TO A LITTLE ABOVE NORMAL...RANGING FROM AROUND 30 NORTHWEST TO AROUND 40 SOUTHEAST. PRECIPITATION WILL BE IN THE FORM OF VALLEY RAIN SHOWERS...MOUNTAIN SNOW OR A RAIN SNOW MIX. ARCTIC AIR WILL FOLLOW BEHIND THIS FEATURE...LOWERING TEMPERATURES TO MAINLY THE TEENS FRIDAY NIGHT AND HOLDING THEM MAINLY IN THE 20S ON SATURDAY. ASIDE FROM SOME POSSIBLE LAKE ENHANCED SNOW SHOWERS ACROSS THE ADIRONDACKS/MOHAWK VALLEY AND SOUTHERN GREENS....OTHER AREAS LOOK DRY BUT BRISK. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... TO START THE TAF PERIOD...MVFR/IFR CONDITIONS ARE LIKELY AT ALL TAF SITES AS A WARM FRONT WILL HAVE ALREADY WORKED THROUGH THE REGION WITH SCATTERED TO NUMEROUS RAIN SHOWERS WITH GUSTY SOUTHERLY WINDS WITH GUSTS OVER 20 KTS POSSIBLE. WIND SHEAR AT 2KFT BETWEEN 55-65 KTS IS POSSIBLE THROUGH 00Z SUNDAY AS A COLD FRONT WILL MAKE ITS WAY FROM WEST TO EAST THROUGHOUT ALL THE TAF SITES. TEMPO GROUPS AT ALL TAF SITES FROM 20Z SATURDAY TO 00Z SUNDAY WITH RAIN AND WINDY CONDITIONS ALONG THE COLD FRONT PASSAGE THROUGH THE REGION. ONCE THE COLD FRONT PASSES THROUGH THE REGION AFTER 00Z SUNDAY...A LEFTOVER VCSH OR -SHRA IS POSSIBLE BEHIND THE FRONT THROUGH 06Z SUNDAY. WINDS WILL SHIFT TO WESTERN TO WEST NORTHWESTERLY 5-10 KTS BEHIND THE FRONT AND IN PARTICULAR...GUSTS STILL ABOVE 20 KTS POSSIBLE ESPECIALLY AT KALB/KPSF. OTHERWISE...CONDITIONS SHOULD IMPROVE TO VFR CONDITIONS AFTER 06Z SUNDAY THROUGH THE END OF THE TAF PERIOD WITH THE END OF THE PRECIPITATION. OUTLOOK... SUN-MON: MODERATE VFR. NO SIG WX. TUES-THUR: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. && .HYDROLOGY... THE FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY...WITH THE PRIMARY THREAT ICE JAM FLOODING. RIVERS ARE RESPONDING TO THE RAINFALL ACROSS THE REGION WITH THE CATSKILLS BEING THE CENTER OF THE HIGHER RAINFALL TOTALS PER MESONET OBSERVATIONS. IN ADDITION...TEMPERATURES ARE QUITE MILD WITH MAINLY 50S AND NOW SOME LOWER 60S FOR THE MID HUDSON VALLEY...NW CT...BERKSHIRES...TACONICS AND WESTERN GREENS /DOWNSLOPING/. LATEST NERFC QPF SUGGESTS THE BEST QPF WILL OCCUR BEFORE 00Z WITH AROUND ONE INCH MAINLY INTO THE TERRAIN SOUTH AND EAST OF ALBANY. FURTHERMORE...ICE JAMS REMAIN THE GREATEST THREAT AS WARMER TEMPERATURES AND RAINFALL WILL ALLOW FOR ICE TO MOVE. THE NEXT SEVERAL DAYS WE WILL EXPERIENCE A DIURNAL RANGE OF ABOVE FREEZING TEMPERATURES DURING THE DAYLIGHT HOURS AND AT OR BELOW FREEZING AT NIGHT. THIS WILL LIKELY RESULT IN ICE MOVEMENT/MELTING WHICH COULD ALSO RESULT IN ISOLATED AREAS OF ICE JAMS. 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 THROUGH SUNDAY AFTERNOON FOR CTZ001-013. NY...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR NYZ032-033-038>043- 047>054-058>061-063>066-082>084. MA...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR MAZ001-025. VT...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR VTZ013>015. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...HWJIV AVIATION...LFM/WASULA HYDROLOGY...BGM FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
1255 PM EST SAT JAN 11 2014 .SYNOPSIS... A STRONG STORM SYSTEM WILL IMPACT OUR REGION TODAY AND TONIGHT WITH MILD TEMPERATURES AND MODERATE TO HEAVY RAINFALL. THE SYSTEM`S LOW WILL MOVE ACROSS EASTERN CANADA DRAGGING ITS ASSOCIATED COLD FRONT ACROSS THE LOCAL AREA THIS EVENING. THE STEADY RAIN WILL COME TO AN END WITH THE PASSAGE OF THE FRONT. THERE WILL BE CHANCES FOR RAIN AND SNOW SHOWERS LATE TONIGHT AND SUNDAY AS A DISTURBANCE IN THE UPPER LEVELS OF THE ATMOSPHERE MOVES OVER THE REGION. IT WILL BE COOLER SUNDAY...HOWEVER TEMPERATURES WILL STILL BE ABOVE NORMAL FOR THIS TIME OF YEAR. && .NEAR TERM /THROUGH TONIGHT/... ...FLOOD WATCH REMAINS IN EFFECT... CONCERNS FOR A PERIOD OF HEAVY RAINFALL ARE ON THE INCREASE THIS AFTERNOON AS PER THE MESOSCALE OBSERVATIONS...PRESSURE FALLS ACROSS NORTHEAST PA AND REGIONAL RADAR REVEAL A MESOLOW DEVELOPING WITH AN INCREASE IN LIGHTNING ACTIVITY. METARS UPSTREAM SHOW ONE QUARTER TO ONE HALF OF AN INCH PER HOUR RAINFALL RATES. FURTHERMORE...TEMPERATURES ARE ALREADY CLOSE TO EXPECTED HIGH TEMPERATURES AND HAVE INCREASED THOSE VALUES A COUPLE OF MORE DEGREES. CROSS SECTIONS FROM THE RUC13 AND OUR VWP SHOW LOW LEVEL JET WAS ON THE INCREASE WITH VALUES CLOSE TO 60KTS JUST ABOVE 2K FEET. THIS TOO WILL ALLOW FOR THE SNOW MELT TO INCREASE ACROSS THE TERRAIN. RIVER RESPONSE WAS JUST BEGINNING AS WE CONTINUE TO CLOSELY MONITOR THE SITUATION CLOSELY. THE COLD FRONT ACROSS WESTERN NY WILL SWEEP ACROSS AREA THIS EVENING BRINGING THE STEADY RAIN TO AN END FROM WEST TO EAST. THERE WILL BE A THREAT FOR RAIN AND SNOW SHOWERS OVERNIGHT MAINLY ACROSS THE HIGHER TERRAIN AS THE UPPER TROUGH APPROACHES. && .SHORT TERM /SUNDAY THROUGH MONDAY/... THE UPPER TROUGH WILL BECOME NEGATIVELY TILTED AS IT SWINGS OVER AHEAD SUNDAY. THE MODELS KEEP THE SYSTEM PROGRESSIVE WITH RIDGING BUILDING IN AT THE SURFACE AND ALOFT IN ITS WAKE. THE RIDGE SHOULD CREST OVER THE REGION SUNDAY NIGHT QUICKLY SHIFTING OFF TO THE EAST MONDAY AS ANOTHER DEEPENING TROUGH APPROACHES. OUR REGION WILL BE UNDER BROAD SOUTHWEST FLOW BETWEEN THE DEPARTING RIDGE AND ADVANCING TROUGH WILL KEEP OUR TEMPERATURES ABOVE NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE EXTENDED FORECAST WILL OPEN MILD WITH ABOVE NORMAL TEMPS...BUT A COOL DOWN BACK TO TYPICAL MID JANUARY WX WILL OCCUR BY THE MID WEEK IN THE WAKE OF A COLD FRONTAL PASSAGE. MONDAY NIGHT INTO TUESDAY...BETTER AGREEMENT THIS CYCLE OF THE DETERMINISTIC MEDIUM RANGE AND ENSEMBLE GUIDANCE THAT A PROGRESSIVE UPPER LEVEL PATTERN WILL IMPACT THE NORTHEAST EARLY IN THE WORK WEEK. A COLD FRONT ASSOCIATED WITH A NRN STREAM DISTURBANCE APPROACHES THE FCST AREA...WITH A SRN STREAM CYCLONE FORMING OVER THE MID ATLANTIC REGION. THIS CYCLONE WILL MOVE NORTHEAST NEAR THE MID ATLANTIC SEABOARD DURING THE AFTERNOON...BUT APPEARS TO BE FAR ENOUGH EAST BASED ON THE ECMWF FOR ONLY A MINIMAL IMPACT ON THE REGION. THE GFS IS EVEN FURTHER OUT TO SEA FOR NO IMPACT...WHILE THE CANADIAN GGEM LOOKS SIMILAR TO THE ECMWF...BUT SLIGHT SLOWER ON THE TIMING OF THE SYSTEM. THE WPC GUIDANCE FAVORS MORE A FRONTAL PASSAGE WITH THIS SYSTEM. A CHC OF RAIN OR SNOW SHOWERS WAS INCLUDED MONDAY NIGHT WITH TEMPS ABOVE NORMAL IN THE LOWER TO MID 30S. THE TIMING OF THE FRONT...AND POTENTIAL WAVE DEVELOPMENT NEAR THE COAST WILL PLAY A CRUCIAL ROLE ON HOW WARM THE SFC TEMPS GET ON TUESDAY. OUR LATEST FCST IS CLOSE TO THE WPC GUIDANCE WITH HIGHS IN THE U30S TO L40S NORTH AND WEST OF THE MOHAWK VALLEY AND UPPER HUDSON REGION WITH GENERALLY MID AND U40S TO THE SOUTH AND EAST. A CHC OF RAIN SHOWERS WAS CONTINUED DURING THE DAY. LOW LEVEL COLD ADVECTION WILL BE ONGOING DURING THE PM WITH H850 TEMPS FALLING TO -2C TO -6C OVER THE REGION. TUESDAY NIGHT INTO WEDNESDAY NIGHT...TRANSITIONAL PERIOD...WHERE SOME LIGHT SNOW OR A PERIOD OF SNOW SHOWERS MAY OCCUR ACROSS THE FCST AREA DEPENDING HOW CLOSE THE COASTAL WAVE IS LOCATED. HAVE LEANED CLOSE TO A GFS/ECMWF/WPC SCENARIO HERE WITH THE FRONT...AND WAVE DRIFTING EASTWARD OF THE REGION...BUT AN UPSTREAM CLIPPER LOW WILL APPROACH EMBEDDED IN THE H500 UPPER LEVEL TROUGH OVER THE ERN CONUS. THIS DISTURBANCE MAY BRING A PERIOD OF LIGHT SNOW AND OR SNOW SHOWERS TO ERN NY AND WRN NEW ENGLAND WED PM INTO WED NIGHT. THE EC IS A LITTLE HEAVIER ON THE QPF WITH THIS SYSTEM...AND MOVES THE SFC WAVE OVER THE SRN NY AND NEW ENGLAND BORDER. THE GFS LIFTS THE CLIPPER N/NE TOWARDS THE ST LAWRENCE RIVER VALLEY WITH LITTLE PCPN OVER THE REGION. HAVE KEPT A SLIGHT OR LOW CHC OF SNOW SHOWERS FOR THE MOST OF THE REGION. THE BEST CHC OF SOME SUSTAINED SNOWFALL LOOKS LIKE IT WILL BE EAST OF THE HUDSON RIVER VALLEY...AND THE HIGHEST CHC POPS ARE KEPT HERE WED NIGHT. LOWS TUE NIGHT WILL BE MAINLY IN THE 20S...WITH HIGHS WED CLOSER TO CLIMATOLOGICAL NORMS IN THE M20S TO L30S NORTH AND WEST OF THE CAPITAL REGION...AND MID TO U30S FROM ALY SOUTH AND EAST. LOWS WED NIGHT WILL FALL INTO THE TEENS AND 20S. THURSDAY INTO FRIDAY...A WEAK SFC RIDGE OF HIGH PRESSURE BUILDS IN BRIEFLY BEFORE ANOTHER UPPER LEVEL DISTURBANCE ASSOCIATED WITH THE H500 UPPER LEVEL LONGWAVE TROUGH APPROACHES QUICKLY FROM THE GREAT LAKES REGION FOR THU NIGHT INTO FRI WITH ANOTHER CHC OF SNOW SHOWERS. THERE IS LIMITED MOISTURE WITH THIS DISTURBANCE AT THIS TIME. IN THE WAKE OF THIS DISTURBANCE H850 TEMPS COULD TUMBLE BACK TO -17C TO -20C ACCORDING TO THE LATEST GFS BY 00Z/SAT. HIGHS BOTH DAYS WILL RANGE FROM THE U20S OVER THE SRN DACKS TO MID AND U30S FROM THE CAPITAL DISTRICT SOUTH AND EAST. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... TO START THE TAF PERIOD...MVFR/IFR CONDITIONS ARE LIKELY AT ALL TAF SITES AS A WARM FRONT WILL HAVE ALREADY WORKED THROUGH THE REGION WITH SCATTERED TO NUMEROUS RAIN SHOWERS WITH GUSTY SOUTHERLY WINDS WITH GUSTS OVER 20 KTS POSSIBLE. WIND SHEAR AT 2KFT BETWEEN 55-65 KTS IS POSSIBLE THROUGH 00Z SUNDAY AS A COLD FRONT WILL MAKE ITS WAY FROM WEST TO EAST THROUGHOUT ALL THE TAF SITES. TEMPO GROUPS AT ALL TAF SITES FROM 20Z SATURDAY TO 00Z SUNDAY WITH RAIN AND WINDY CONDITIONS ALONG THE COLD FRONT PASSAGE THROUGH THE REGION. ONCE THE COLD FRONT PASSES THROUGH THE REGION AFTER 00Z SUNDAY...A LEFTOVER VCSH OR -SHRA IS POSSIBLE BEHIND THE FRONT THROUGH 06Z SUNDAY. WINDS WILL SHIFT TO WESTERN TO WEST NORTHWESTERLY 5-10 KTS BEHIND THE FRONT AND IN PARTICULAR...GUSTS STILL ABOVE 20 KTS POSSIBLE ESPECIALLY AT KALB/KPSF. OTHERWISE...CONDITIONS SHOULD IMPROVE TO VFR CONDITIONS AFTER 06Z SUNDAY THROUGH THE END OF THE TAF PERIOD WITH THE END OF THE PRECIPITATION. OUTLOOK... SUN-MON: MODERATE VFR. NO SIG WX TUES-THUR: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. && .HYDROLOGY... THE FLOOD WATCH REMAINS IN EFFECT FOR THIS AFTERNOON THROUGH SUNDAY...WITH THE PRIMARY THREAT ICE JAM FLOODING. A STRONG LOW PRESSURE WILL MOVE INTO SOUTHEASTERN CANADA TODAY INTO TONIGHT WITH SOME MODERATE TO HEAVY RAINFALL OCCURRING AHEAD OF A FRONTAL BOUNDARY. TEMPERATURES WILL RISE INTO THE MID 40S TO LOWER 50S AHEAD OF THE FRONT ALLOWING SNOW MELT TO OCCUR ACROSS THE REGION. RAINFALL AMOUNTS OF 3/4 TO AN INCH FROM THE CAPITAL DISTRICT NORTH AND WEST AND 1 TO 1 1/2 INCHES TO THE SOUTH AND EAST WITH LOCALLY HIGHER AMOUNTS. THE RAINFALL WILL FALL ON FROZEN GROUND WHICH WILL BECOME RUNOFF AND MAY POTENTIALLY CAUSE STREET OR POOR DRAINAGE FLOODING OF LOW LYING AREAS. THE WARM TEMPERATURES COMBINED WITH THE RAINFALL MAY CAUSE ICE MOVEMENT AND BREAK UP FOR ICE JAM FLOODING ON SOME OF THE RIVERS AND STREAMS. ICE JAM FLOODING WOULD HAVE ITS GREATEST THREAT LATE THIS AFTERNOON INTO SUNDAY. IT APPEARS THAT THE GREATEST POTENTIAL FOR FLOODING AT THIS TIME WILL INCLUDE...BUT NOT BE LIMITED TO...THE HOOSIC RIVER AT WILLIAMSTOWN AND EAGLE BRIDGE...AND THE WALLOOMSAC RIVER AT BENNINGTON. DESPITE THE PASSAGE OF THE SYSTEM...ABOVE NORMAL TEMPERATURES ARE EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK. NIGHTTIME TEMPERATURES WILL FALL TO AROUND FREEZING OR BELOW. OUR NEXT BEST CHANCES FOR WIDESPREAD PRECIPITATION WILL BE TUESDAY. 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 THROUGH SUNDAY AFTERNOON FOR CTZ001-013. NY...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR NYZ032-033-038>043- 047>054-058>061-063>066-082>084. MA...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR MAZ001-025. VT...FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR VTZ013>015. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM/11 SHORT TERM...IAA LONG TERM...WASULA AVIATION...LFM HYDROLOGY...IAA/WASULA FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1040 AM EST SAT JAN 11 2014 .SYNOPSIS... AN INTENSIFYING LOW PRESSURE SYSTEM OVER THE UPPER PENINSULA OF MICHIGAN WILL MOVE NORTHEAST TOWARD JAMES BAY IN CANADA TODAY. ITS ASSOCIATED COLD FRONT WILL CROSS THE REGION TONIGHT. HIGH PRESSURE WILL THEN BUILD OVER THE AREA SUNDAY AND MONDAY, FOLLOWED BY ANOTHER COLD FRONT ON TUESDAY. A SECONDARY COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA WEDNESDAY WITH A LOW PRESSURE SYSTEM POSSIBLY DEVELOPING ALONG IT NEAR OUR FORECAST AREA. A HIGH PRESSURE SYSTEM FROM THE SOUTHERN ROCKIES WILL THEN NOSE INTO THE REGION ON THURSDAY. AN ARCTIC COLD FRONT IS FORECAST TO MOVE THROUGH THE AREA LATER FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SHARP TEMPERATURE BOUNDARY ACROSS THE AREA HAS BEEN ONE OF THE FORECAST CHALLENGES THIS MORNING. STRONG S WINDS AND MUCH MILDER TEMPERATURE LIE ON THE WARMER SIDE OF THIS BOUNDARY. HAVE USED LATEST LAV AND RUC GUIDANCE TO BEST CAPTURE FORECAST TRENDS. ADDED ISOLATED THUNDER TO NW HALF OF FORECAST AREA THRU 18Z AS SOME ISOLATED LIGHTNING STRIKES WERE DETECTED IN THE HEAVIER PRECIPITATION. VERY HIGH DEWPOINTS OVER COLD MARINE WATERS HAVE RESULTED IN WIDESPREAD FOG AND THAT WAS ADDED TO THE GRIDDED FORECAST WITH VISIBILITIES A HALF MILE OR LESS. STARTING TO SEE RESPONSE FROM SMALLER CREEKS AND STREAMS IN NW PART OF FORECAST AREA FROM RAIN SO FAR. MORE DETAILS IN HYDROLOGY SECTION. PREVIOUS DISCUSSION FOLLOWS. LOW PRESSURE WILL MOVE FROM THE UPPER GREAT LAKES THIS MORNING NORTHEASTWARD INTO SOUTHERN CANADA BY TONIGHT. AN ATTACHED COLD FRONT WILL APPROACH THE WESTERN AREAS LATE THIS AFTERNOON. A DEEP MOIST SRLY FLOW WILL BE ACROSS THE AREA THROUGH THE DAY...AND SEVERAL SHORT WAVES WILL BRING PERIODS OF RAIN AND PSBLY A FEW TSTMS (SOUTH) TO THE REGION. POPS ARE CATEGORICAL THROUGH THE DAY. THE GREATEST CHC FOR THUNDER IS MOSTLY SOUTH (DELMARVA/SRN NJ) WHERE GREATER INSTABILITY WILL RESIDE. SPC HAS THESE AREAS IN THE SGT CHC FOR THUNDER TODAY. WINDS JUST OFF THE DECK ARE RATHER STRONG TODAY...THE DEGREE OF MIXING SHOULD NOT BE THAT GREAT WITH THE WARMER AIR ARRIVING OVER A COOLER SFC AIR MASS...ALTHOUGH A WIND ADV WAS CONSIDERED...WE DECIDED INSTEAD TO ISSUE AND SPS WITH THE MENTION OF GUSTY WINDS NEAR TSTMS TODAY. SPOTTY GUSTS AROUND 40-45 MPH POSSIBLE. TEMPS TODAY WILL CONTINUE THE SLOW UPWARD TREND AS OF LATE. TEMPS OVER THE SRN AREAS (WHICH ARE ALREADY IN THE 50S) SHOULD REACH THE MID 60S...WHILE THEN NRN AREAS WILL REACH THE LOW/MID 50S. QPF WILL AVERAGE AROUND 1.0 TO 1.5 INCHES ACROSS MOST AREAS TODAY AND EARLY TONIGHT...LOCAL 2.0 INCH AMTS ARE POSSIBLE. SEE HYDRO SECTION BELOW FOR MORE INFO. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... CONDITIONS WILL IMPROVE OVERNIGHT AS THE COLD FRONT PASSES OFF THE COAST 01Z-03Z. WINDS WILL BECOME WRLY AND PCPN WILL END FROM W TO E. TEMPERATURES WILL DROP BACK THROUGH THE 40S (SOUTH) AND INTO THE LOW/MID 30S OVER THE NRN AREAS. PCPN WILL END AS RAIN IN ALL AREAS WITH THE COLDER AIR ARRIVING LATER AT NIGHT. WINDS WILL BE SOMEWHAT GUSTY WITH GUSTS 15-20 MPH EXPECTED OVERNIGHT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A VERY ACTIVE WEATHER PATTERN IS EXPECTED IN THE LONG TERM AS WE HEAD BACK TOWARD A COLDER REGIME. THE GFS INITIALIZATION LOOKED BETTER THAN THE WRF-NMMB, THE 500MB TROF IS DEEPER. THE 850MB AND 925MB INITIALIZATION AVERAGED ABOUT A DEGREE TOO LOW. THIS IS A TENDENCY THAT HAS BEEN AROUND FOR A COUPLE OF NIGHTS AND PROBABLY ONE OF THE REASONS FOR MORE SNOW NORTHWEST YESTERDAY. FARTHER INTO THE LONG TERM, THE MEDIUM RANGE MODELS ARE STARTING TO COME CLOSER WITH DOUBLE BARREL THREATS TUESDAY AND WEDNESDAY AND A CANADIAN OR ARCTIC CFP AT THE END OF THE DETERMINISTIC PERIOD. HERE WE TOOK A MODELING CONSENSUS UNTIL THE DETAILS CAN BE SORTED BETTER. THE TUESDAY SYSTEM`S TROF THAT IS NOW IN THE GULF OF ALASKA SHOULD GET INTO THE DENSER SOUNDING NETWORK ON SUNDAY. A BRISK BUT DRY DAY FOR SUNDAY. WITH THE NORTHWEST FLOW OFF ONTARIO AND AT LEAST A HIGH ENOUGH INVERSION, WE DID INCLUDE SOME SNOW FLURRIES FOR THE POCONOS. ELSEWHERE, THE FCST SOUNDINGS ARE NOT EXPECTED TO BE REACHED AND MOSTLY SUNNY SKIES SHOULD OCCUR. GUIDANCE HAS BEEN EDGING COOLER AND WE LOWERED MAX TEMPS SLIGHTLY, MORE IN LINE WITH GFS MOS THAN NAM MOS. IF THERE IS GOING TO BE A RADIATIONAL COOLING NIGHT, IT WILL BE SUNDAY NIGHT AS THE RIDGE AXIS GETS CLOSEST TO OUR CWA UNDER CLEAR SKIES. THE CAA IS ALSO DONE. WE WENT WITH THE LOWER STAT GUIDANCE IN OUTLYING/MORE RURAL AREAS AND A COMPROMISE ELSEWHERE. A SOUTHWEST FLOW OF MILDER AIR ON MONDAY. THIS REBOUND MAY BE TEMPERED BY SOME RETURN FLOW MOISTURE (CLOUDS) AS BY THEN THE RIDGE AXIS WILL BE EAST OF OUR REGION. BASED ON FCST 925MB TEMPS, WE REMAINED OPTIMISTIC ABOUT THE COASTAL PLAIN LOCATIONS REACHING THE 50S. SO WE ARE AT OR SLIGHTLY ABOVE STAT GUIDANCE. THE NEXT PCPN EVENT IS SLATED FOR MONDAY NIGHT AND TUESDAY. THE GFS REMAINS AMONG THE FASTEST. MOST OF THE OTHER MODELS 500MB TROF IS DEEPER AND THIS TIME OF YEAR DEEPER SOLUTIONS NORMALLY PREVAIL. SO WE SLOWED THE TIMING DOWN CLOSER TO THE ECMWF. DEEPER ALSO MEANS WETTER WITH MORE GULF MOISTURE INVOLVEMENT. WE WILL KEEP A BUNCH OF EYES ON THIS FACET. PTYPE LOOKS TO BE MAINLY RAIN. SLOWER TIMING ALSO MEAN HIGHER TEMPS AND WE KEPT MINS AND MAX TEMPS CLOSE TO CONTINUITY. THERE SHOULD BE A PCPN BREAK ON TUESDAY NIGHT BEFORE THE NEXT COLD FRONT ARRIVES ON WEDNESDAY. HERE THE GFS REMAINS FASTER AND DOES NOT DIG THE NEXT NEXT TROF AS MUCH AS OTHER MEDIUM RANGE MODELS. THE ECMWF WHILE IT REMAINS STRONGER WITH THE COLD AIR CYCLOGEN ALONG THE FRONT, HAS BACKED AWAY FROM THE DEEPER/MORE SOUTHERN DEVELOPMENT IT HAD LAST NIGHT. ONE OF THE REASONS IS THE CLOSED LOW OVER EASTERN QUEBEC HAS DP/DTING BEEN LIFTING NORTHWARD WITH EACH SUCCEEDING RUN. THIS HAS DEFACTOED THE NAO TO BE LESS NEGATIVE AND THUS A MORE NORTHERN DEVELOPMENT. THIS IS FAR FROM BEING ETCHED IN STONE AND THIS ONE WOULD BE COLD ENOUGH TO HAVE SOME SNOW OCCUR. AFTER THIS LOW DEPARTS, HIGH PRESSURE WILL BUILD INTO THE REGION. WHILE TEMPERATURES SHOULD RETURN CLOSER TO NORMAL, THIS HIGH`S ORIGIN IS FROM THE PACIFIC. SO UNLIKE LAST WEEK`S VERSION, THIS AIR MASS HAS MORE OF ITS COLDNESS (RELATIVE TO NORMAL) IN THE UPPER HALF OF THE TROPOSPHERE. THE NEXT COLD FRONT IS SCHEDULED FOR FRIDAY. THIS ONE MAY BE MOISTURE STARVED. BUT THE ENSUING HIGH BEHIND THIS FRONT IS COMING FROM WESTERN CANADA AND WILL BRING EVEN COLDER AIR BACK INTO THE REGION. PLEASE DONT CURB YOUR ENTHUSIASM. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. POOR FLYING CONDITIONS AT MOST SITES THIS MORNING AND EXPECTED INTO THIS AFTERNOON WITH PERIODS OF IFR CONDITIONS IN LOW CEILINGS AND VISIBILITIES IN FOG AND RAIN. A LOW LEVEL JET IS IN PLACE AND WILL CONTINUE FOR MUCH OF THE DAY. TWO THOUSAND FT WINDS IN THE 50 TO 60 KNOT RANGE. A FEW TSTMS MAY OCCUR THIS AFTERNOON SOUTH/EAST...BUT THEY WERE NOT PLACED IN THE TAFS ATTM. COLD FRONT WILL APPROACH THE WRN TERMINALS 21-23Z. TONIGHT...THE COLD FRONT WILL CROSS THE DEL VALLEY 23Z-01Z AND THE OFF TH COAST 01Z-03Z. WINDS WILL SHIFT TO WRLY AND REMAIN GUSTY FOLLOWING THE FRONT. THE SHOWERS WILL END FROM W TO E AND THEN CIGS/VSBYS WILL IMPROVE BACK TO VFR A FEW HOURS AFTER FROPA. SKIES MAY IMPROVE BACK TO FEW/SCT BY DAWN SUNDAY. OUTLOOK... SUNDAY AND SUNDAY NIGHT...VFR. WEST-NORTHWEST WINDS 15-20 KNOTS AND GUSTY, DIMINISHING AT NIGHT. MONDAY...PREDOMINATELY VFR. GUSTY SOUTHWEST WINDS DEVELOPING. MONDAY NIGHT AND TUESDAY...VFR GIVING WAY TO POSSIBLE MVFR IN RAIN. POSSIBLY SNOW POCONO AIRPORTS. TUESDAY NIGHT...A VFR PERIOD. CONFIDENCE OF TIMING BETWEEN SYSTEMS IS LOW. WEDNESDAY...MVFR TO IFR CONDITIONS POSSIBLE WITH A GREATER INFILTRATION OF SNOW AS A PRECIPITATION TYPE. GUSTY NORTHWEST WINDS LATER WEDNESDAY. && .MARINE... MID-MORNING MARINE FORECAST UPDATE ADDED WIDESPREAD FOG WITH VISIBILITIES DOWN TO A HALF MILE (AND EVEN LOWER IN SOME LOCATIONS) DUE TO MILD HIGH DEW POINT AIR OVER COLD MARINE WATERS. GALE WARNINGS CONTINUE IN PLACE. PREVIOUS DISCUSSION BELOW. MARINE PRODUCTS WERE UPDATED JUST BEFORE 700 AM TO PLACE THE GALE WARNING IN EFFECT. BUOYS ARE ALREADY SHOWING GUSTS APPROACHING GALES...AND THE TREND LOOKS TO CONTINUE. ONE CHANGE MADE TO THE ONGOING FLAGS FOR THE WATERS. THE GALE WARNING FOR THE OCEAN WAS ALSO PLACED OVER DEL BAY WITH THE LOW LEVEL WINDS EXPECTED TO GUST AT THE ELEVATED WIND PLATFORMS OVER THE BAY. THE WINDS AND SEAS WILL STEADILY INCREASE TODAY AS THE SRLY FLOW AHEAD OF THE APPROACHING LOW/FRONT REMAIN OVER THE REGION. OCCASIONAL SHOWERS WILL BE ON THE WATERS THROUGH THE EVENING. THERE IS A CHC FOR A TSTM WITH LOCAL HIGHER WINDS/SEAS OVER ALL THE WATERS THIS AFTERNOON INTO THE EVENING. AREAS OF FOG ARE ALSO EXPECTED WITH THE HIGHER DEW POINTS MOVING ACROSS THE COLD WATERS...THERE MAY BE JUST ENOUGH WINDS TO MIX IT INTO A LOW OVC HOWEVER. CONFID IN LOW VSBY DENSE FOG IS LOW...SO IT WAS NOT PLACED IN THE GRIDS. TONIGHT...WINDS SHIFT WRLY/NWRLY AND THE PCPN ENDS AFTER MIDNIGHT. GALES WILL LIKELY BE REPLACED WITH SCA FLAGS FOR A WHILE LATER TONIGHT. OUTLOOK... SUNDAY...SMALL CRAFT CONDITIONS ARE EXPECTED...DIMINISHING LATE IN THE DAY AS THE CAA WEAKENS AS DOES THE WESTERLY FLOW. MONDAY AND MONDAY NIGHT...POSSIBLE LOW END SMALL CRAFT ADVISORY CRITERIA IN SOUTHERLY FLOW PRECEDING A COLD FRONT. TUESDAY...NEAR SMALL CRAFT ADVISORY CRITERIA ON THE OCEAN AS ANOTHER COLD FRONT MOVES THROUGH. SUB SMALL CRAFT ADVISORY CRITERIA ON DELAWARE BAY. TUESDAY NIGHT AND WEDNESDAY...A POSSIBLE SMALL CRAFT ADVISORY LULL PERIOD WITH AN INCREASING LIKELIHOOD OF SMALL CRAFT ADVISORY CRITERIA RETURNING BEHIND THE PASSAGE OF THE NEXT COLD FRONT. && .HYDROLOGY... ALREADY STARTING TO SEE SOME RESPONSE IN SMALLER CREEKS AND STREAMS TO RAINFALL SO FAR (WHICH HAS BEEN A HALF INCH OR LESS). HEAVIER RAIN LIES AHEAD. ALSO SEEING REPORTS IN SOCIAL MEDIA OF EXTREME PONDING OF WATER FROM RAIN THAT HAS FALLEN SO FAR DUE TO GROUND BEING FROZEN. THIS WILL PROMOTE HIGHER LEVELS OF RUNOFF FROM TODAY`S RAIN, LEADING TO A HIGHER RISK OF FLASH FLOODING AND MORE SIGNIFICANT STREAM RESPONSE TO RAINFALL. PREVIOUS DISCUSSION BELOW. INTO TONIGHT, A PLUME OF PW VALUES UP TO 1.5 INCHES IS FORECAST TO SURGE ACROSS OUR AREA AHEAD OF A STRONG COLD FRONT. THERE IS A GOOD AMOUNT OF FLOW AND ALSO FORCING TO PRODUCE A SHIELD OF RAIN, SOME OF WHICH WILL BE MODERATE TO HEAVY AT TIMES. THE SYSTEM IS FORECAST TO BE PROGRESSIVE, THEREFORE HEAVIER RAIN SHOULD TEND TO BE MORE LIMITED IN DURATION. HOWEVER, DURING TIMES OF HEAVIER RAIN THERE CAN BE PONDING OF WATER ON ROADWAYS AND SOME FLOODING IN AREAS OF POOR DRAINAGE. THE 1-HOUR AND 3-HOUR FLASH FLOOD GUIDANCE IS THE LOWEST GENERALLY ACROSS THE INTERSTATE 95 CORRIDOR. IN ADDITION, WE HAVE HAD ICE JAMS ON SOME AREA RIVERS AND RIVER/CREEK ICE CONTINUES. IT IS DIFFICULT TO KNOW HOW THE ICE BEHAVES, THEREFORE RAPID CHANGES IN WATER LEVELS CAN OCCUR. A RAPID WARM UP IS ANTICIPATED TODAY WITH THE AREA GETTING WELL INTO THE 50S AND EVEN SOME LOWER TO MID 60S. MUCH OF THE REGION THOUGH HAS LITTLE SNOW COVER SO THERE WILL BE LESS RUNOFF FROM THIS. BUT, THE TOP LAYER OF GROUND IS FROZEN AND UNLESS IT DOES A QUICK THAW, RUNOFF WILL BE VERY EFFICIENT. WALKING OUTSIDE THE OFFICE OVERNIGHT, THERE IS SOME GIVE TO THE GROUND, BUT NOT MUCH YET. SOME ENSEMBLE GUIDANCE INDICATES THAT SEVERAL RIVER FORECAST POINTS GET TO FLOOD STAGE, ESPECIALLY SMALLER STREAMS. THEREFORE, A FLOOD WATCH REMAINS IN EFFECT FOR MOST OF OUR CWA FOR THIS AFTERNOON AND NIGHT. OUTSIDE OF THE FLOOD WATCH, SOME PONDING OF WATER ON ROADS AND POOR DRAINAGE FLOODING IS POSSIBLE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ054-055-060>062-070- 071-101>106. NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ001-007>010-012-013- 015>019. DE...FLOOD WATCH THROUGH LATE TONIGHT FOR DEZ001. MD...FLOOD WATCH THROUGH LATE TONIGHT FOR MDZ008. MARINE...GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. && $$ SYNOPSIS...GIGI/MIKETTA NEAR TERM...SZATKOWSKI/O`HARA SHORT TERM...SZATKOWSKI/O`HARA LONG TERM...GIGI AVIATION...GIGI/SZATKOWSKI/MIKETTA/O`HARA MARINE...GIGI/SZATKOWSKI/MIKETTA/O`HARA HYDROLOGY...SZATKOWSKI/
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
400 PM EST SAT JAN 11 2014 .DISCUSSION... CURRENTLY...PREFRONTAL CONVECTIVE LINE PUSHING ACRS THE PANHANDLE TOWARD THE BIG BEND THIS AFTN. SAT PICS SHOW THE COLDEST STORM TOPS TRAILING BACK TO THE LOOP CURRENT OVER THE CENTRAL GOMEX BUT STRUGGLING TO EXPAND MUCH BEYOND A 100NM BAND AS IT APPROACHES THE NRN PENINSULA. RUC ANALYSIS SHOWING RESPECTABLE MID LVL OMEGA/UPR LVL DIVERGENCE FIELDS ACCOMPANYING THE LINE...AS WELL AS SUFFICIENT MOISTURE TO MAINTAIN THE LINE AS IT APPROACHES THE I-4 CORRIDOR. HOWEVER...VORTICITY FIELDS ARE QUITE WEAK...AS ARE THE PREFRONTAL MID LVL LAPSE RATES (GENERALLY AOB 5C/KM). TONIGHT... STORM SYSTEM CENTERED N OF THE GREAT LAKES WILL BE FED BY A 100-120KT H30-H20 JET STREAK DIGGING ACRS THE CENTRAL/NRN PLAINS AND A 120-140KT JET LIFTING OUT OF THE RIO GRANDE VALLEY. PROGRESSIVE NATURE OF THE SYSTEM WILL ERODE THE WRN FLANK OF A LARGE HI PRES RIDGE OVER THE W ATLC AND ALLOW THE SYSTEM TO CRANK A COLD FRONT THROUGH THE CENTRAL PENINSULA BY DAYBREAK. HOWEVER...DEEP MID/UPR LVL RIDGING OVER CUBA AND THE NW CARIB WILL DEFLECT THE MAJORITY OF THE SYSTEM ENERGY TO THE N AND AWAY FROM CENTRAL FL. FURTHERMORE... MORNING SOUNDINGS SHOW A SIGNIFICANT AMOUNT OF DRY AIR THRU THE H85-H60 LYR THAT WILL ERODE THE CONVECTIVE LINE AS IT PUSHES THROUGH CENTRAL FL. HIGHEST PRECIP CHANCES ACRS THE N...HOWEVER...THE LIFTING NATURE OF THE LEADING JET STREAK AND THE POSITIVE TILT OF THE TROF AXIS ARE NOT TYPICALLY CONDUCIVE TO SIG OUTBREAKS OF STRONG/SVR WX. RADAR/SAT TREND DOES NOT LEND HIGH CONFIDENCE MUCH MORE THAN A THIN LINE OF SHRAS/TSRAS WITH WIND GUSTS BTWN 35-40KTS...WILL GO WITH SCT POPS AREAWIDE...50PCT ACRS THE I-4 CORRIDOR...DECREASING TO 30PCT ARND THE NE SHORE OF LAKE OKEECHOBEE. LITTLE CHANGE TO THE MIN TEMP FCST AS TIMING OF THE FROPA WILL RESULT IN A FAIRLY WIDE SPREAD. READINGS WILL FALL INTO THE M/U50S ALONG AND N OF THE I-4 CORRIDOR DUE TO THE LONGER DURATION OF POST FRONTAL COOL AIR ADVECTION...THE TREASURE COAST WILL HOLD IN THE M/U60S AS THE CRUX OF THE COOL AIR WILL NOT HAVE MADE IT THAT FAR SOUTH BY DAYBREAK. SUNDAY... PROGRESSIVE WX PATTERN WILL PUSH THE POST FRONTAL HIGH PRES RIDGE ACRS THE DEEP SOUTH THRU THE DAY. MODERATE H100-H85 FLOW WILL RESPOND BY SHIFTING STEADILY FROM NW AT DAYBREAK...TO DUE N BY MIDDAY...TO THE E/NE BY SUNSET. SHORT DURATION OF THE NRLY FLOW WILL RETURN MAX TEMPS TO NEAR CLIMO AVG FOR EARLY JAN...U60S/L70S ALONG AND N OF I-4 AND L/M70S TREASURE COAST AND THE NE SHORE OF LAKE OKEECHOBEE. SUNDAY NIGHT THROUGH MONDAY NIGHT... SHORTWAVE RIDGE BRIEFLY BUILDS ALOFT SUNDAY NIGHT WITH FLOW QUICKLY BECOMING CYCLONIC AGAIN EARLY MONDAY AS SHORTWAVE TROUGH APPROACHES. COOLER TEMPS SUNDAY NIGHT...BUT REMAINING A FEW DEGREES ABOVE CLIMO. SURGE OF DEEPER MOISTURE FROM THE S/SW SHOULD LIFT PRECIPITABLE WATER VALUES TO 1.3-1.5 INCH RANGE BY LATE MONDAY. SOUTHERLY FLOW WILL ALLOW TEMPS TO REBOUND TO 5-10 DEGREES ABOVE CLIMO MON. MOISTURE CONVERGENCE SHOULD PROMOTE A FEW AFTERNOON SHOWERS WITH THE GREATEST CHANCE ACROSS THE NORTHERN CWA LATE IN THE DAY...WELL AHEAD OF NEXT FRONTAL BOUNDARY. TIMING/POP DIFFERENCES REMAIN IN REGARDS TO FRONTAL PASSAGE...WITH GFS FASTER/WETTER WITH SERIES OF WEAK SURFACE WAVES ALONG THE BOUNDARY...WHEREAS ECM IS CONSIDERABLY SLOWER WITH ANY SURFACE DEVELOPMENT OCCURRING INLAND ACROSS THE SE STATES...AND THEREFORE LOWER POPS LOCALLY. TRENDED TOWARD SLOWER ECM GUIDANCE...WHICH WAS ALSO CLOSER TO PREVIOUS OFFICIAL FORECAST...BUT DID RAISE POPS SLIGHTLY MONDAY NIGHT AND ADDED ISOLATED THUNDERSTORM POSSIBILITY. WARMER MINS TUE MORNING WITHIN PRE-FRONTAL SOUTHERLY FLOW. TUE-FRI... AS STRONG SHORTWAVE DIVES SOUTH FROM THE NORTHERN PLAINS TUE...LONGWAVE TROUGH AMPLIFIES/SHARPENS CONSIDERABLY FROM THE GREAT LAKES TO THE CENTRAL GULF STATES. OWING TO THE SLOWER ECM SCENARIO...TUESDAY SEEMS TO BE THE FOCUS OF BOTH MODELS FOR BRINGING PRECIP THROUGH CWA. RETURN TO NEAR NORMAL TEMPS EXPECTED TUESDAY POST FROPA...GENERALLY LOWER TO MID 70S. COOLER AND DRY WEATHER IS EXPECTED BEHIND THE FRONT INTO THE LATTER HALF OF THE WEEK WITH A REINFORCING DRY FRONT. DAYTIME HIGHS WILL BE IN THE MID-UPPER 60S WITH LOW 70S ACROSS THE TREASURE COAST AND OKEECHOBEE COUNTY. OVERNIGHT LOWS IN THE MID 40S...WITH A FEW UPPER 30S/LOW 40S IN COLDER SPOTS. MAY NEED TO TREND TEMPS DOWN FURTHER BEHIND SECONDARY FRONTAL PASSAGE WEDNESDAY NIGHT THROUGH THE END OF THE WEEK IF FUTURE MODEL RUNS SHOW CONSISTENCY WITH DEEPER AMPLITUDE OF MID/UPPER TROUGH. && .AVIATION... THRU 12/00Z...SFC WND BCMG SW WITH OCNL G22-26KT...CHC MVFR SHRAS ALL SITES THRU 12/06Z...SLGT CHC IFR TSRAS N OF KTIX-KISM AFT THRU 12/03Z. BTWN 12/06Z-12/09Z...SFC WND BCMG W/NW BTWN 8-12KTS...SLGT CHC MVFR SHRAS S OF KMLB-KLAL CONTG THRU 12/12Z. AFT 12/12Z SFC WND BCMG N/NW 8-12KTS ALL SITES. && .MARINE... TONIGHT...POOR BOATING CONDITIONS AS A COLD FRONT SWEEPS THROUGH THE THE LCL ATLC AND GENERATES A MODERATE TO FRESH SW BREEZE THAT WILL VEER STEADILY TO THE W IN THE PREDAWN HRS...THEN TO THE NW BY DAYBREAK. LCL WATERS WILL BE FETCH PROTECTED FOR MUCH OF THE NIGHT DUE TO THE OFFSHORE BREEZE...LIMITING SEA HEIGHTS TO 3-4FT NEARSHORE AND 4-6FT OFFSHORE...THOUGH SEAS UP TO 7FT OVER THE GULF STREAM ARE EXPECTED N OF SEBASTIAN INLET. MUCH OF THE WAVE ENERGY WILL BE DUE TO SHORT PD WIND CHOP. SUNDAY...PROGRESSIVE WX PATTERN WILL PUSH THE POST FRONTAL HI PRES RIDGE ACRS THE SE CONUS AND INTO THE W ATLC THRU THE PD. SFC/BNDRY LYR WINDS WILL RESPOND BY VEERING FROM NW TO NE WHILE DIMINISHING TO A GENTLE TO MODERATE BREEZE. SHORT DURATION OF THE ENHANCED WIND FIELD WILL LIMIT SEA HEIGHTS TO 3-5FT NEARSHORE AND 5-7FT OFFSHORE AROUND DAYBREAK...DECREASING TO 2-4FT NEARSHORE AND 3-5FT OFFSHORE AROUND SUNSET. SUNDAY NIGHT-MONDAY NIGHT...ONSHORE FLOW AOB 15 KT WILL VEER FROM EAST TO SOUTH/SOUTHWEST WELL IN ADVANCE OF FRONTAL TROUGH. TUE-WED...WINDS COME AROUND TO THE SOUTHEAST 5-10KTS ON MONDAY AS THE HIGH DEPARTS QUICKLY OFF TO THE EAST. INCREASING SOUTHERLY FLOW EXPECTED MONDAY NIGHT AHEAD OF THE NEXT FRONT. SOME TIMING DIFFERENCE BETWEEN MODELS...BUT APPEARS THAT THE ACTUAL WIND SHIFT WILL HOLD OFF UNTIL TUESDAY NIGHT...LEAVING WEST-SOUTHWEST WINDS 15KTS DURING THE DAY ON TUESDAY BECOMING NORTHWEST TUES EVE AND NIGHT. SECONDARY FRONTAL BOUNDARY MOVES JUST NORTH OF THE WATERS ON WED...BACK WINDS TO THE WEST ON WED WITH THE TIGHTENING GRADIENT BRINGING WINDS UP TO 20KTS. LIGHT WINDS WILL KEEP SEAS 2-4FT ON MONDAY...THOUGH THE STRONGER OFFSHORE COMPONENT INTO TUES WILL BUILD SEAS UP TO 6FT WELL OFFSHORE NORTH OF THE CAPE BY LATE TUE INTO WED. SEAS GENERALLY 2-3 FT NEARSHORE AND 3-5 FT OFFSHORE SUNDAY NIGHT/MONDAY...WILL BUILD TO 3-4 FT NEARSHORE AND 3-6 FEET OFFSHORE MONDAY NIGHT. ISOLATED SHOWERS SUNDAY NIGHT BECOME SCATTERED MONDAY AND MONDAY NIGHT. && .FIRE WEATHER... COLD FROPA TONIGHT WILL FORCE SFC/TRANSPORT WINDS TO VEER TO NW TONIGHT...FOLLOWED BY A POST FRONTAL HIGH PRES RIDGE ON SUN THAT WILL PUSH WINDS TO THE N/NE. A BRIEF BUT STRONG PERIOD OF DRY AIR ADVECTION WILL ALLOW MIN RH VALUES TO FALL TO 30-35PCT FOR 4-6HRS ACRS THE INTERIOR N OF LAKE KISSIMMEE/LAKE MARIAN. HOWEVER...ERC NUMBERS ARE LOW ENOUGH DUE TO RECENT PRECIP EVENTS THAT OVERALL FIRE THREAT WILL REMAIN LOW. && .PRELIMINARY POINT TEMPS/POPS... DAB 58 66 49 77 / 50 0 10 30 MCO 60 71 50 79 / 50 0 10 20 MLB 63 70 55 79 / 40 0 10 20 VRB 65 71 55 80 / 30 10 10 20 LEE 56 69 49 77 / 50 0 10 30 SFB 59 70 51 78 / 50 0 10 20 ORL 60 71 52 78 / 50 0 10 20 FPR 66 72 55 80 / 30 10 10 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...LAKE WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR COASTAL VOLUSIA-INLAND VOLUSIA-NORTHERN BREVARD-NORTHERN LAKE- ORANGE-OSCEOLA-SEMINOLE-SOUTHERN BREVARD-SOUTHERN LAKE. AM...SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE. && $$ SHORT TERM/AVIATION...BRAGAW LONG TERM/IMPACT WX...SPRATT
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
300 PM EST SAT JAN 11 2014 .SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE ACROSS THE CONUS. MAIN PLAYER FOR OUR FORECAST THE NEXT 18-24 HOURS WILL IS A DEEP AND SHARP LONGWAVE TROUGH EJECTING EASTWARD FROM THE CENTRAL PLAINS INTO THE EASTERN STATES. THE BASE OF THIS TROUGH EXTENDS SOUTHWARD TO THE NORTHERN GULF COAST AND WILL PIVOT INTO THE SOUTHEASTERN STATES THROUGH THE EVENING AND OVERNIGHT HOURS. THIS TROUGH IS "BOOKENDED" BY LONGWAVE RIDGES OVER BOTH THE INTER-MOUNTAIN WEST AND NOW EXITING OFF THE ATLANTIC SEABOARD. AT THE SURFACE...HIGH PRESSURE RIDGE IS BEING SHOVED SOUTH AND EAST OUT OF THE PENINSULA IN RESPONSE TO THE APPROACH OF A SURFACE COLD FRONT AHEAD OF THE UPPER TROUGH. THIS FRONT CURRENTLY EXTENDS DOWN FROM NORTHERN GEORGIA TO THE FLORIDA PANHANDLE AND NORTHEAST GULF OF MEXICO. SOUTHERLY FLOW AHEAD OF THE FRONT IS BRINGING WITH IT A WARM AND HUMID BOUNDARY LAYER. THIS HIGH DEWPOINT AIR OVER THE NOW COOL SHELF WATERS OF THE EASTERN AND NORTHEASTERN GULF OF MEXICO IS RESULTING IN AREAS/WIDESPREAD SEA FOG (SOME VERY DENSE) OVER THE COASTAL WATERS. THE FOG IS MOST PREVALENT TO THE NORTH OF SARASOTA AND CONDITION WILL REMAIN FAVORABLE FOR THE REDUCED VISIBILITIES THROUGH AT LEAST THE EARLY EVENING UNTIL THE COLD FRONT CAN PASS AND CLEAR THE MORE HUMID AIRMASS AWAY. GENERALLY SPEAKING WE LOOK FOR DEWPOINTS TO BE 3-5+ DEGREES WARMER THAN THE SURFACE WATER TEMPERATURES FOR A SIGNIFICANT THREAT OF SEA FOG. AFTER LAST WEEKS "COLD SNAP"...THE SHELF WATERS COOLED OFF CONSIDERABLY AND HAVE ALLOWED THESE CONDITIONS TO BE MET. A MARINE DENSE FOG ADVISORY IS IN EFFECT TO THE NORTH OF ENGLEWOOD THROUGH THE MIDDLE EVENING AND MULTIPLE REPORTS OF VISIBILITY NEAR ZERO HAVE BEEN RECEIVED THROUGH THE DAY FROM AREAS TO THE WEST OF EGMONT KEY. && .SHORT TERM (REST OF TODAY THROUGH MONDAY NIGHT)... AS MENTIONED ABOVE...THE UPPER TROUGH WILL PIVOT EASTWARD AND FORCE THE COLD FRONT THROUGH THE AREA TONIGHT. LOW/MID LEVEL WAA ALONG WITH DEEP SYNOPTIC FORCING/DCVA/QV CONVERGENCE AHEAD OF THE TROUGH AXIS ARE SUPPORTING A SOLID MCS CLUSTER OF SHOWERS/STORMS FROM GA TO THE NORTHEAST GULF THIS AFTERNOON. THIS FORCING ALONG WITH A FAVORABLE RRQ JET PLACEMENT WILL SHIFT EASTWARD WITH TIME INCREASING THE CHANCES FOR SHOWERS AND A FEW STORMS TO OUR ZONES NORTH OF TAMPA BAY BY THE LATE AFTERNOON HOURS/EARLY EVENING HOURS. THE BEST CHANCES FOR RAIN BEFORE SUNSET WILL BE FOR THESE NORTHERN ZONES. ELSEWHERE...THE SYNOPTIC FORCING WILL NOT ARRIVE DURING THE DAYLIGHT HOURS...BUT AN INCREASINGLY UNSTABLE ENVIRONMENT MAY STILL ALLOW FOR A FEW SCT SHOWERS TO DEVELOP ACROSS THE INTERIOR PENINSULA. SOME OF THE MORE RELIABLE HIGH-RES GUIDANCE MEMBERS SUCH AS THE HRRR CONTINUE TO HINT AT THIS POSSIBILITY...BUT DO TO THE LACK OF ACTIVITY THUS FAR WILL DECREASE THE POPS TO 20% FOR THESE SOUTH-CENTRAL INLAND ZONES. DURING THE EVENING HOURS THE BEST SYNOPTIC FORCING ARRIVES OVER THE NORTHERN PENINSULA ALONG WITH THE COLD FRONT/PRE-FRONTAL TROUGH FOR LOW LEVEL FOCUS. THE CHANCES FOR A BAND OF SHOWERS AND STORM IS FAIRLY HIGH AND HENCE SO ARE THE POPS. THE STORM PREDICTION CENTER HAS OUTLOOKED CITRUS AND LEVY COUNTY FOR A SLIGHT RISK OF SEVERE WEATHER THIS EVENING. WHILE IT IS NOT COMPLETELY OUT OF THE QUESTION FOR A FEW STRONGER STORMS...THE LOW LEVEL JET IS QUITE LIMITED THIS FAR SOUTH AND WILL BE STARTING TO EXIT THE AREA. ALSO...HIGHLY QUESTIONABLE IF ANY OF THESE STORMS WILL BE TRULY ROOTED AT THE SURFACE WITH THE FLOW DEVELOPING OFF THE COOLER SHELF WATERS. MORE LIKELY THAT ANY STORMS WILL BE AT LEAST PARTIALLY ELEVATED WHICH WILL FURTHER LIMIT THE WIND THREAT. THIS DOES NOT MEAN THAT BRIEF HEAVY RAIN AND LIGHTNING MAY NOT BE A THREAT WITH ANY STRONGER CELLS SINCE THE OVERALL FORCING FOR ASCENT IS QUITE STRONG. DESPITE THE LIMITING FACTORS...WE WILL CONTINUE TO MONITOR THE LOW LEVEL ENVIRONMENT IN CASE CONDITIONS BECOME MORE FAVORABLE FOR SURFACE BASED PARCELS OVER THE NORTHERN NATURE COAST AS THE DAY PROGRESSES. THE COLD FRONT AND ASSOCIATED CLUSTERS OF SHOWERS/ISOLATED STORMS WILL SHIFT SOUTH AND EAST ACROSS THE AREA THIS EVENING AND BE MAINLY SOUTH OF TAMPA BAY BY THE SECOND HALF OF THE NIGHT. THE CONVECTION WILL ALSO BECOME LESS ORGANIZED AND LIKELY MORE BROKEN WITH TIME AS THE UPPER LEVEL FORCING AND JET DYNAMICS PIVOTS AWAY FROM THE REGION. JUST HAVE CHANCE POPS FOR SHOWERS TO THE SOUTH OF TAMPA BAY AFTER MIDNIGHT AND END ALL RAIN DOWN TO EVEN FORT MYERS BY SUNRISE ON SUNDAY. SUNDAY...A DRIER AIRMASS ALONG WITH SEASONABLE TEMPERATURES AND CLEARING SKIES WILL FILL THE REMAINDER OF THE WEEKEND AS HEIGHTS RISE ALOFT OF THE PENINSULA...AND SURFACE HIGH PRESSURE SLIDES EASTWARD INTO THE REGION FROM THE EASTERN GULF. SUNDAY NIGHT... THE ONE "COOLER" NIGHT BEHIND THIS FRONT. AT THIS TIME WE ARE NOT EXPECTING A THREAT FOR FREEZING TEMPERATURES FOR EVEN OUR MOST NORTHERN ZONES...ALTHOUGH WITH THE HIGH IN CLOSE PROXIMITY AND GENERALLY CLEAR SKIES...SOME PATCHY FROST IS NOT OUT OF THE QUESTION LATE AT NIGHT FOR THE COLDEST RADIATIONAL COOLING SPOTS UP TOWARD LEVY COUNTY. OTHERWISE LOOKING FOR LOW TO RANGE FROM THE LOW TO MID 40S NORTH...TO THE UPPER 40S/MIDDLE 50S SOUTH. MONDAY AND MONDAY NIGHT... THE NEXT LONGWAVE TROUGH (POTENTIAL WEATHER MAKER) BEGINS TO DIG THROUGH THE CENTRAL CONUS AND APPROACH OUR REGION LATER MONDAY AND MONDAY NIGHT. GFS/ECMWF DO NOT FULLY AGREE ON THE DETAILS...BUT DO AGREE ON AT LEAST SOME LOBE OF SHORTWAVE ENERGY ROUNDING THE BASE OF THIS TROUGH AND RESULTING IN A WEAK WAVE OF LOW PRESSURE MOVING ALONG THE NORTHERN GULF COAST. THE COLD FRONT TRAILING BACK FROM THIS FEATURE LOOKS TO APPROACH OUR ZONES MONDAY NIGHT OR TUESDAY MORNING. FOR NOW HAVE FAVORED THE MORE NORTHWARD LOW TRACK IN CLOSER PROXIMITY TO THE TRUE NORTHERN GULF SST BAROCLINIC ZONE...AND LATER FRONTAL ARRIVAL OF THE ECMWF. THIS SOLUTION KEEP US A BIT WARMER AND RESULTS IN AN ARRIVAL TIME OF ANY ORGANIZED SHOWERS HOLDING OFF UNTIL MONDAY NIGHT OR TUESDAY MORNING AS WELL. && .LONG TERM (TUESDAY THROUGH NEXT SATURDAY)... MODELS ARE IN RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIODS...WITH JUST SOME MINOR DISCONTINUITIES. THE FIRST REVOLVES AROUND A COLD FRONT PASSAGE IN THE MONDAY NIGHT/TUESDAY TIME FRAME...WHERE THE GFS IS FASTER THEN THE NAM/ECMWF/CANADIAN...SO WILL LEAN THE FORECAST TOWARD THE MODEL CONSENSUS AND SLOWER SOLUTION. THE OTHER DISCONTINUITY RESIDES AROUND THE AMPLITUDE OF THE UPPER TROUGH DIGGING INTO THE SOUTHEAST CONUS WEDNESDAY AND WEDNESDAY NIGHT WHICH HAS AN IMPACT ON THE STRENGTH OF COLD AIR ADVECTION PUSHING SOUTHWARD THROUGH THE PENINSULA. THE CANADIAN/ECMWF ARE IN GOOD AGREEMENT WITH THE AMPLITUDE OF THE TROUGH WHILE THE GFS IS NOT QUITE AS STRONG. AS A RESULT...WILL LEAN THE FORECAST MID WEEK TOWARD THE CANADIAN/ECMWF SOLUTION. BY LATE NEXT WEEK MODEL SOLUTIONS SHOW HIGH PRESSURE BUILDING BACK INTO THE REGION ON THURSDAY WITH YET ANOTHER RE-ENFORCING COLD FRONT MOVING THROUGH THE AREA FRIDAY NIGHT. THERE IS SOME DISAGREEMENT ON THE DEGREE OF COLD AIR ADVECTION ONCE AGAIN...BUT GIVEN THAT THERE IS QUITE SOME TIME BETWEEN NOW AND NEXT WEEKEND...WILL JUST TAKE A BLENDED APPROACH TO LIMIT POTENTIAL FORECAST ERROR. AS FOR FORECAST DETAILS...WILL CARRY RAIN CHANCES IN THE FORECAST WITH THE INITIAL COLD FRONT MONDAY NIGHT AND TUESDAY. AFTER THAT...THE NEXT COUPLE FRONTAL PASSAGES WILL LACK ANY SIGNIFICANT RETURN FLOW MOISTURE FROM THE GULF OF MEXICO...SO EXPECT THAT RAIN FREE CONDITIONS WILL PREVAIL TUESDAY NIGHT THROUGH NEXT SATURDAY. AS FOR TEMPERATURES...EXPECT HIGHS CLOSE TO NORMAL ON TUESDAY BEFORE DROPPING TO BELOW NORMAL LEVELS THROUGH THE REMAINDER OF THE WEEK AND INTO NEXT WEEKEND. && .AVIATION... 11/18Z-12/18Z...GUSTY WINDS WITH GENERALLY VFR CLOUDS BUT LCL MVFR CIG REST OF THIS AFTERNOON. CONDITIONS THEN DETERIORATE FOR THE OVER NIGHT HOURS WITH MVFR CIGS...POSSIBLE SEA FOG DRIFTING ACROSS THE NORTHERN COASTAL TERMINALS...AND VCNTY SHRA EXCEPT VCNTY TSRA EARLY IN THE PERIOD FROM KSRQ NORTHWARD. DRY AIR FILTERS IN JUST AFTER DAY BREAK WITH CLEARING AND NORTHERLY WINDS. && .MARINE... A COLD FRONT WILL CROSS THE FORECAST WATERS FROM NORTHWEST TO SOUTHEAST TONIGHT ALONG WITH A BAND OF SHOWERS AND ISOLATED STORMS. MODERATE SOUTHWEST WINDS AHEAD OF THE FRONT WILL SHIFT NORTHWEST IN ITS WAKE AND BRIEFLY REACH CAUTIONARY LEVELS BEFORE DROPPING BACK BELOW HEADLINE CRITERIA SUNDAY MORNING. HIGH PRESSURE WILL THEN BE IN CONTROL OF THE EASTERN GULF OF MEXICO THROUGH AT LEAST MONDAY MORNING BEFORE THE NEXT COLD FRONT APPROACHES MONDAY NIGHT OR TUESDAY. AREAS OF DENSE MARINE FOG TO THE NORTH OF SARASOTA WILL CONTINUE TO BE AN ISSUE UNTIL THE PASSAGE OF THE COLD FRONT LATER THIS EVENING ENDS THE THREAT FOR REDUCED VISIBILITY. && .FIRE WEATHER. A COLD FRONT WILL CROSS THE REGION OVERNIGHT WITH A BAND OF SHOWERS AND STORMS AND USHER IN A COOLER AND MUCH DRIER AIRMASS FOR SUNDAY. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP BELOW 35 PERCENT FOR MUCH OF THE REGION SUNDAY AFTERNOON...HOWEVER WITH LIGHT WINDS AND LOW ERC VALUES...NO RED FLAG CONDITIONS ARE ANTICIPATED. ENOUGH MOISTURE RETURN WILL REACH THE AREA BY MONDAY TO PREVENT ANY CRITICALLY LOW RELATIVE HUMIDITY. FOG POTENTIAL...AREAS OF DENSE FOG ARE EXPECTED ALONG THE COAST FROM PINELLAS COUNTY NORTHWARD THIS EVENING WITH THE FOG LIFTING AS A COLD FRONT CROSSES THE AREA OVERNIGHT. && .PRELIMINARY POINT TEMPS/POPS... TPA 59 71 52 73 / 60 0 0 10 FMY 65 76 55 79 / 40 0 0 10 GIF 58 73 50 77 / 60 0 0 10 SRQ 61 71 53 75 / 60 0 0 10 BKV 55 70 43 75 / 60 0 0 10 SPG 61 69 54 74 / 60 0 0 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...LAKE WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR COASTAL CHARLOTTE-COASTAL CITRUS-COASTAL HERNANDO-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL LEVY-COASTAL MANATEE- COASTAL PASCO-COASTAL SARASOTA-DESOTO-HARDEE- HIGHLANDS-INLAND CHARLOTTE-INLAND CITRUS-INLAND HERNANDO-INLAND HILLSBOROUGH-INLAND LEE-INLAND LEVY- INLAND MANATEE-INLAND PASCO-INLAND SARASOTA-PINELLAS- POLK-SUMTER. GULF WATERS...DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM. && $$ SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA LONG TERM...JELSEMA AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1100 AM EST SAT JAN 11 2014 .UPDATE (REST OF TODAY THROUGH SUNDAY)... 15Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE ACROSS THE CONUS. MAIN PLAYER FOR OUR FORECAST THE NEXT 24 HOURS WILL IS A DEEP AND SHARP LONGWAVE TROUGH EJECTING EASTWARD FROM THE CENTRAL PLAINS INTO THE EASTERN STATES. THE BASE OF THIS TROUGH EXTENDS SOUTHWARD TO THE NORTHERN GULF COAST AND WILL PIVOT INTO THE SOUTHEASTERN STATES THROUGH THE EVENING AND OVERNIGHT HOURS. THIS TROUGH IS "BOOKENDED" BY LONGWAVE RIDGES OVER BOTH THE INTER-MOUNTAIN WEST AND NOW EXITING OFF THE ATLANTIC SEABOARD. AT THE SURFACE...HIGH PRESSURE RIDGE IS BEING SHOVED SOUTH AND EAST OUT OF THE PENINSULA IN RESPONSE TO THE APPROACH OF A SURFACE COLD FRONT AHEAD OF THE UPPER TROUGH. THIS FRONT CURRENTLY EXTENDS DOWN FROM NORTHERN GEORGIA TO THE WESTERN FLORIDA PANHANDLE AND NORTH-CENTRAL GULF OF MEXICO. SOUTHERLY FLOW AHEAD OF THE FRONT IS BRINGING WITH IT A WARM AND HUMID BOUNDARY LAYER. THIS HIGH DEWPOINT AIR OVER THE NOW COOL SHELF WATERS OF THE EASTERN AND NORTHEASTERN GULF OF MEXICO IS RESULTING IN AREAS/WIDESPREAD SEA FOG (SOME VERY DENSE) OVER THE COASTAL WATERS. THE FOG IS MOST PREVALENT TO THE NORTH OF SARASOTA AND CONDITION WILL REMAIN FAVORABLE FOR THE REDUCED VISIBILITIES THROUGH AT LEAST THE EARLY EVENING UNTIL THE COLD FRONT CAN PASS AND CLEAR THE MORE HUMID AIRMASS AWAY. GENERALLY SPEAKING WE LOOK FOR DEWPOINTS TO BE 3-5+ DEGREES WARMER THAN THE SURFACE WATER TEMPERATURES FOR A SIGNIFICANT THREAT OF SEA FOG. AFTER LAST WEEKS "COLD SNAP"...THE SHELF WATERS COOLED OFF CONSIDERABLY AND HAVE ALLOWED THESE CONDITIONS TO BE MET. A MARINE DENSE FOG ADVISORY IS IN EFFECT TO THE NORTH OF ENGLEWOOD THROUGH THE EARLY EVENING AND MULTIPLE REPORTS OF VISIBILITY NEAR ZERO HAVE BEEN RECEIVED THIS MORNING FROM AREAS TO THE WEST OF EGMONT KEY. ENOUGH WITH THE FOG...ON TO THE COLD FRONT LATER TODAY AND TONIGHT. AS MENTIONED ABOVE...THE UPPER TROUGH WILL PIVOT EASTWARD AND FORCE THE COLD FRONT THROUGH THE AREA TONIGHT. LOW/MID LEVEL WAA ALONG WITH DEEP SYNOPTIC FORCING/DCVA/QV CONVERGENCE AHEAD OF THE TROUGH AXIS ARE SUPPORTING MULTIPLE MCS CLUSTERS OF SHOWERS/STORMS FROM GA/AL TO THE NORTH-CENTRAL GULF LATE THIS MORNING. THIS FORCING ALONG WITH A FAVORABLE RRQ JET PLACEMENT WILL SHIFT EASTWARD WITH TIME INCREASING THE CHANCES FOR SHOWERS AND A FEW STORMS TO OUR ZONES NORTH OF TAMPA BAY BY THE LATE AFTERNOON HOURS. THE BEST CHANCES BEFORE SUNSET WILL BE UP TOWARD CITRUS/LEVY COUNTIES. ELSEWHERE...THE SYNOPTIC FORCING WILL NOT ARRIVE DURING THE DAYLIGHT HOURS...BUT AN INCREASINGLY UNSTABLE ENVIRONMENT MAY ALLOW FOR A FEW SCT SHOWERS TO DEVELOP BY LATE AFTERNOON ACROSS THE INTERIOR PENINSULA. SOME OF THE MORE RELIABLE HIGH-RES GUIDANCE MEMBERS SUCH AS THE HRRR ARE HINTING AT THIS POSSIBILITY AND HAVE INCLUDED A 30% CHANCE POP INLAND (JUST IN CASE). DURING THE EVENING HOURS THE BEST SYNOPTIC FORCING ARRIVES OVER THE NORTHERN PENINSULA ALONG WITH THE COLD FRONT/PRE-FRONTAL TROUGH FOR LOW LEVEL FOCUS. THE CHANCES FOR A BAND OF SHOWERS AND STORM IS FAIRLY HIGH AND HENCE SO ARE THE POPS. THE STORM PREDICTION CENTER HAS OUTLOOKED CITRUS AND LEVY COUNTY FOR A SLIGHT RISK OF SEVERE WEATHER THIS EVENING. WHILE IT IS NOT COMPLETELY OUT OF THE QUESTION FOR A FEW STRONGER STORMS...THE LOW LEVEL JET IS QUITE LIMITED THIS FAR SOUTH AND WILL BE STARTING TO EXIT THE AREA. ALSO...HIGHLY QUESTIONABLE IF ANY OF THESE STORMS WILL BE TRULY ROOTED AT THE SURFACE WITH THE FLOW DEVELOPING OFF THE COOLER SHELF WATERS. MORE LIKELY THAT ANY STORMS WILL BE AT LEAST PARTIALLY ELEVATED WHICH WILL FURTHER LIMIT THE WIND THREAT. THIS DOES NOT MEAN THAT BRIEF HEAVY RAIN AND LIGHTNING MAY NOT BE A THREAT WITH ANY STRONGER CELLS SINCE THE OVERALL FORCING FOR ASCENT IS QUITE STRONG. DESPITE THE LIMITING FACTORS...WE WILL CONTINUE TO MONITOR THE LOW LEVEL ENVIRONMENT IN CASE CONDITIONS BECOME MORE FAVORABLE FOR SURFACE BASED PARCELS OVER THE NORTHERN NATURE COAST AS THE DAY PROGRESSES. THE COLD FRONT AND ASSOCIATED CLUSTERS OF SHOWERS/ISOLATED STORMS WILL SHIFT SOUTH AND EAST ACROSS THE AREA THIS EVENING AND BE MAINLY SOUTH OF TAMPA BAY BY THE SECOND HALF OF THE NIGHT. THE CONVECTION WILL ALSO BECOME LESS ORGANIZED AND LIKELY MORE BROKEN WITH TIME AS THE UPPER LEVEL FORCING AND JET DYNAMICS PIVOTS AWAY FROM THE REGION. JUST HAVE CHANCE POPS FOR SHOWERS TO THE SOUTH OF TAMPA BAY AFTER MIDNIGHT AND END ALL RAIN DOWN TO EVEN FORT MYERS BY SUNRISE ON SUNDAY. A DRIER AIRMASS ALONG WITH SEASONABLE TEMPERATURES AND CLEARING SKIES WILL FILL THE REMAINDER OF THE WEEKEND AS HEIGHTS RISE ALOFT OF THE PENINSULA...AND SURFACE HIGH PRESSURE SLIDES EASTWARD INTO THE REGION FROM THE EASTERN GULF. ENJOY YOUR SATURDAY AND WATCH OUT FOR THE FOG ALONG THE COAST. && .AVIATION... EARLY MORNING IFR/LIFR CIGS WITH PATCHY BR ARE NOW LIFTING WITH ONLY IFR CIGS AT SRQ/PIE/TPA. AFT 15Z EXPECT VFR...LCL MVFR CIGS...WITH GUSTY WINDS THROUGH THE AFTERNOON. APPROACHING FRONT WITH MAINLY SHRA ARRIVES TONIGHT WITH SOME MVFR TO IFR CONDITIONS. && .MARINE... A COLD FRONT WILL APPROACH THE AREA THROUGH THE DAY WITH INCREASING SOUTH TO SOUTHWEST WINDS AHEAD OF IT. AREAS OF DENSE MARINE FOG WILL BE PRESENT ACROSS THE FORECAST WATERS UNTIL THE FRONTAL PASSAGE THIS EVENING. HIGH PRESSURE WILL THEN BUILD BACK INTO THE REGION SUNDAY THROUGH MONDAY. THE NEXT COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA ON TUESDAY WITH ANOTHER PERIOD OF INCREASED WINDS EXPECTED. && .PRELIMINARY POINT TEMPS/POPS... TPA 77 59 72 55 / 40 60 10 10 FMY 83 65 79 57 / 20 40 10 10 GIF 82 58 72 53 / 40 60 10 10 SRQ 78 61 72 53 / 40 60 10 10 BKV 80 52 71 44 / 60 60 10 10 SPG 77 61 70 58 / 40 60 10 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...LAKE WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR COASTAL CHARLOTTE-COASTAL CITRUS-COASTAL HERNANDO-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL LEVY-COASTAL MANATEE- COASTAL PASCO-COASTAL SARASOTA-DESOTO-HARDEE- HIGHLANDS-INLAND CHARLOTTE-INLAND CITRUS-INLAND HERNANDO-INLAND HILLSBOROUGH-INLAND LEE-INLAND LEVY- INLAND MANATEE-INLAND PASCO-INLAND SARASOTA-PINELLAS- POLK-SUMTER. GULF WATERS...DENSE FOG ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM. && $$ UPDATE/MARINE...MROCZKA AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1122 AM EST SAT JAN 11 2014 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA THIS AFTERNOON. HIGH PRESSURE BEHIND THE FRONT WILL BE OVER OUR REGION SUNDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY NIGHT. ANOTHER COLD FRONT WILL MOVE INTO THE AREA MONDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HIGH MOISTURE ASSOCIATED WITH THE STRONG H85 JET AND LIFT WITH THE RIGHT ENTRANCE REGION OF THE H25 JET PLUS CONVERGENCE ALONG THE COLD FRONT SUPPORT CATEGORICAL POPS THIS AFTERNOON. THE NAM AND GFS PLUS SREF MEAN INDICATED GENERAL RAINFALL TOTALS AROUND 0.7 OF AN INCH...BUT WITH PRECIPITABLE WATER NEAR 1.6 OF AN INCH HEAVIER AMOUNTS WILL LIKELY OCCUR IN SOME LOCATIONS. THE NAM DISPLAYS SURFACE-BASED LI/S LOWERING TO -1 TO -2 THIS AFTERNOON. SATELLITE LOOP ALSO SHOWS SOME HOLES IN THE CLOUDS ACROSS THE ERN PORTION OF THE CWA. THIS COULD INCREASE THE INSTABILITY THREAT FOR AREAS MAINLY ACROSS THE ERN MIDLANDS...EAST OF COLUMBIA. THE NAM AND GFS HAVE H85 WINDS NEAR 60 KNOTS. THE MAIN THREAT IS DAMAGING STRAIGHT-LINE WINDS BUT FORECAST HODOGRAPHS ALSO SUPPORT POSSIBLE TORNADOES. 06Z HRRR INDICATES THE MAIN CONVECTIVE LINE WILL BE IN THE FORECAST AREA DURING THE NOON TO 500 PM TIME FRAME. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... DRYING WILL OCCUR BEHIND THE FRONT TONIGHT. THE SHOWER CHANCE WILL DECREASE RAPIDLY FROM WEST TO EAST DURING THE EVENING. HIGH PRESSURE WILL BE OVER THE FORECAST AREA SUNDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY NIGHT. THE TEMPERATURE GUIDANCE WAS CONSISTENT. TEMPERATURES WILL BE ABOVE NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... THE GFS AND ECMWF DISPLAY MOISTURE ASSOCIATED WITH A COLD FRONT MONDAY NIGHT INTO TUESDAY. THE ECMWF CONTINUES TO INDICATE MORE MOISTURE COMPARED TO THE GFS. CONTINUED CHANCE POPS BECAUSE OF THE MODEL INCONSISTENCY. EXPECT A REINFORCING COLD FRONT WITH LIMITED MOISTURE WEDNESDAY. THE MODELS SHOW DRY RIDGING DOMINATING THURSDAY WITH YET ANOTHER COLD FRONT WILL LITTLE MOISTURE FRIDAY. ABOVE NORMAL TEMPERATURES SHOULD OCCUR AHEAD OF THE FRONT TUESDAY...WITH COOLING TO NEAR OR SLIGHTLY BELOW NORMAL BY THURSDAY. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... RESTRICTIONS DOMINATING THROUGH 12/00Z THEN CONDITIONS IMPROVING. COLD FRONT CONTINUES TO MARCH ACROSS THE SOUTHEAST WITH WSR-88D NETWORK SHOWING SHOWERS AND A FEW THUNDERSTORMS MOVING THROUGH EASTERN GA TOWARD AGS/DNL. WINDS HAVE ALREADY INCREASED AT THE TAF SITES WITH FURTHER INCREASES OVER THE NEXT COUPLE OF HOURS TO AROUND 15 KNOTS WITH GUSTS TO 25 KNOTS BY 16-18Z AT ALL SITES. LIFR AND IFR CONDITIONS EARLIER THIS MORNING HAVE IMPROVED TO MVFR IN MANY AREAS. LATER THIS MORNING AND INTO THE AFTERNOON THUNDERSTORMS REMAIN THE CONCERN...THE BEST CHANCE APPEARS TO BE BETWEEN 17-21Z. WITH THUNDERSTORMS WHICH DEVELOP THE POTENTIAL EXISTS FOR STRONG AND GUSTY WINDS. WIND SHEAR WILL ALSO BE A CONCERN AS LOW LEVEL WINDS WILL BE AROUND 45-50 KNOTS THROUGH THE AFTERNOON. HAVE INCLUDED WIND SHEAR FOR ALL TAF SITES THROUGH THE AFTERNOON. FRONT WILL MOVE OFFSHORE THIS EVENING WITH DRIER AIR BEGINNING TO MOVE IN WITH CONDITIONS RETURNING TO VFR BY 12/01Z AT CAE/CUB/AGS/DNL AND 12/02Z OGB. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MONDAY NIGHT THROUGH TUESDAY MORNING IN SHOWERS ASSOCIATED WITH THE NEXT COLD FRONT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 77
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
720 AM EST SAT JAN 11 2014 ...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING... .SYNOPSIS... A STRONG COLD FRONT WILL SWEEP ACROSS THE REGION THIS EVENING. HIGH PRESSURE WILL BUILD SUNDAY AND QUICKLY MOVE OFF THE COAST MONDAY...BEFORE ANOTHER COLD FRONT MOVES THROUGH THE AREA BY TUESDAY MORNING. HIGH PRESSURE WILL REBUILD DURING THE MIDDLE OF NEXT WEEK...WITH YET ANOTHER COLD FRONT APPROACHING BY FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AN ACTIVE DAY IS ON TAP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA AS A COLD FRONT APPROACHES FROM THE WEST. AHEAD OF THE FRONT...INCREASING WARM AIR ADVECTION BEING DRIVEN BY A STRONG PRE-FRONTAL LOW-LEVEL JET WILL HELP PUSH TEMPERATURES INTO THE LOWER-MID 70S FOR MOST AREAS AWAY FROM THE COAST... WHICH IS ABOUT 10-15 DEGREES ABOVE NORMAL. AS WARM AIR ADVECTION INTENSIFIES...ISOLATED TO SCATTERED SHOWERS WILL LIKELY BREAKOUT AND AFFECT PORTIONS OF THE AREA PRIOR TO THE ARRIVAL OF THE MAIN CONVECTIVE LINE. ATTM IT APPEARS THE MAIN CONVECTIVE LINE... POSSIBLY IN THE FORM OF A STRONG/SEVERE QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/...WILL REACH THE FAR WESTERN ZONES BY EARLY AFTERNOON AND REACH THE COAST BY LATE AFTERNOON OR EARLY THIS EVENING. H3R INSTABILITY PROGS AND NAM/RAP MODIFIED POINT SOUNDINGS SUGGEST SBCAPE VALUES WILL RISE TO 900-1200 J/KG WITH LIFTED INDICES DROPPING AS LOW AS -4 TO -6C. ALTHOUGH MID-LEVEL LAPSE RATES WILL BE POOR...HEALTHY 0-6KM BULK SHEAR OF 50-60 KT INDUCED BY STRONG LOW-LEVEL JETTING COUPLED WITH MODEST INSTABILITY WILL SUPPORT A RISK FOR SEVERE TSTMS WITHIN A TYPICAL MID-JANUARY HIGH SHEAR/LOW CAPE ENVIRONMENT. THE PRIMARY HAZARD RIGHT NOW LOOK TO BE DAMAGING WINDS WITH A RISK FOR ISOLATED TORNADOES WHERE DISCRETE CELLS OR EMBEDDED MESO-VORTICES WITHIN BOWING CONVECTIVE LINE SEGMENTS CAN DEVELOP. RAP 0-1KM HELICITY VALUES INCREASE TO NEAR 300 M2/S2 AND THE HIGH SHEAR/LOW CAPE SHERBS3 TORNADO PARAMETER RISES ABOVE THE BENCH MARK OF 1 UNIT FOR MUCH OF THE AREA...ALL SUGGESTING THERE IS A REASONABLE RISK FOR TORNADOES. FOR TODAY...WILL HIGHLIGHT POPS NEAR 100 PERCENT FOR ALL AREAS WITH THE HIGHEST GRIDDED POPS PLACED WITH THE EXPECTED TIMING/PLACEMENT OF THE EXPECTED CONVECTIVE LINE. HIGHS WILL BE IN THE LOWER TO MID 70S UNDER MAINLY CLOUDY SKIES. WILL INCLUDE DAMAGING WIND AND TORNADO ATTRIBUTES IN ALL GRIDDED AND TEXT PRODUCTS AND HIGHLIGHT A POTENTIAL FOR SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. THE WINDOW OF GREATEST SEVERE THREAT LOOKS TO BE 1 PM THROUGH 7 PM. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... TONIGHT...CONDITIONS WILL RAPIDLY IMPROVE THIS EVENING AS THE PRIMARY CONVECTIVE LINE PUSHES OFFSHORE AND THE COLD FRONT MOVES THROUGH. EXPECT CLEARING TO OCCUR DURING THE EVENING HOURS WITH MAINLY CLEAR SKIES DEVELOPING BY MIDNIGHT...IF NOT SOONER. LOWS WILL RANGE FROM THE LOWER 40S WELL INLAND TO THE UPPER 40S AT THE BEACHES. SUNDAY...DRY HIGH PRESSURE WILL BUILD IN THE WAKE OF THE DEPARTING COLD FRONT...YET PROGRESSIVE FLOW ALOFT WILL PULL THE CENTER OF THE HIGH QUICKLY TOWARD THE NEARBY ATLANTIC WATERS. COLD ADVECTION WILL BE WEAK BEHIND THE FRONT...AND WITH WIND DIRECTIONS REMAINING GENERALLY WEST/SOUTHWEST...EXPECT ONLY A SLIGHT COOLING TREND TO OCCUR. HIGH TEMPERATURES IN THE MID TO UPPER 60S WILL BE COOLER THAN THE PREVIOUS DAY...YET STILL BE WELL ABOVE SEASONAL NORMALS. AN AMPLIFYING LONG WAVE TROUGH ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT WILL SUPPORT BRIEF DOWNSTREAM HEIGHT RISES...AND WHEN COMBINED WITH WARM ADVECTION WITHIN BACKING LOW LEVEL FLOW...LOW TEMPERATURES IN THE UPPER 30S INLAND TO LOW 40S NEAR THE COAST WILL ALSO BE SEVERAL DEGREES WARMER THAN AVERAGE. MONDAY...SOUTHERN STREAM SHORTWAVE ENERGY TRACKING ACROSS THE GULF OF MEXICO WILL SPIN UP A SURFACE WAVE ALONG THE WESTERN PERIPHERY OF THE RETREATING ATLANTIC HIGH PRESSURE. THERE REMAINS NOTABLE DISAGREEMENT BETWEEN MODEL SOLUTIONS REGARDING THE STRENGTH AND TRACK OF THIS LOW PRESSURE WAVE AND TRAILING FRONT AS THEY PROGRESS TOWARD THE FORECAST AREA THROUGH THE DAY. IN GENERAL...A SOLID TAP INTO GULF MOISTURE WILL SUPPORT A SWATH OF PRECIPITATION ASSOCIATED WITH THE SYSTEM...AND EXPECT RAIN CHANCES TO INCREASE FROM SOUTHWEST TO NORTHEAST DURING THE LATE AFTERNOON TO EVENING TIME FRAME. WARM ADVECTION AND PRE-FRONTAL COMPRESSION WILL SUPPORT TEMPERATURES PEAKING IN THE MID TO UPPER 60S...EVEN AS CLOUD COVER GRADUALLY INCREASES. THE BEST RAIN POTENTIAL ACTUALLY APPEARS TO OCCUR OVERNIGHT INTO EARLY TUESDAY MORNING..AS THE SURFACE LOW LIFTS NORTH/NORTHEAST AND PULLS THE FRONT INTO THE REGION. LOW TEMPERATURES WILL BE QUITE MILD AS A RESULT...ONLY FALLING INTO THE UPPER 40S TO AROUND 50 DEGREES. TUESDAY...THE SYNOPTIC PATTERN REMAINS A BIT UNSETTLED EVEN AFTER THE FRONT MOVES OFFSHORE...WITH ANOTHER LARGE AREA OF UPPER LEVEL ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION. RAIN CHANCES WILL DECREASE DURING THE MORNING HOURS BEHIND THE DEPARTING COLD FRONT. HOWEVER DRY SURFACE HIGH PRESSURE IN ITS WAKE WILL BECOME SUPPRESSED TO THE SOUTH...AS YET ANOTHER FRONT DRIVEN BY THE AMPLIFYING UPPER SHORTWAVE DESCENDS FROM THE OHIO VALLEY LATE IN THE DAY. ONCE AGAIN...DOWNSLOPE FLOW AND THE LACK OF SOLID COLD ADVECTION WILL SUPPORT ABOVE NORMAL HIGH TEMPERATURES IN THE MID 60S. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE DEEPENING UPPER TROUGH WILL SHIFT OVER THE EAST COAST STATES ON WEDNESDAY...WITH A DRY COLD FRONT MOVING ACROSS THE REGION EARLY IN THE DAY. THERE APPEARS TO BE MORE NOTABLE COLD ADVECTION BEHIND THIS FRONT...AND EXPECT HIGH TEMPERATURES TO BE SUPPRESSED IN THE MID 50S UNDER MOSTLY CLEAR SKIES ON WEDNESDAY. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE THE COLDEST SEEN IN DAYS...AS LIGHT WINDS AND LITTLE TO NO CLOUD COVER SET UP IDEAL RADIATIONAL COOLING CONDITIONS. A NEARLY ZONAL UPPER PATTERN ON THURSDAY WILL BE RATHER TRANSIENT...AS BROAD TROUGHING BECOMES THE DOMINANT FEATURE ALOFT FRIDAY AND SATURDAY. CONSIDERING DRY SURFACE HIGH PRESSURE WILL ALSO SETTLE OVER THE REGION...EXPECT TEMPERATURES TO BE GENERALLY BELOW NORMAL AND RAIN CHANCES TO REMAIN BELOW 15 PERCENT THROUGH THE EXTENDED FORECAST PERIOD. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... FOG IS IN THE PROCESS OF LIFTING INTO VERY LOW STRATUS DECKS AT BOTH TERMINALS AS BOUNDARY LAYER WINDS INCREASE. LIFR CIGS WILL LINGER THROUGH ABOUT 14Z BEFORE SLOWLY RISING. UNTIL THEN...CIGS WILL REMAIN VERY NEAR AIRFIELD MINIMUMS AND WELL BELOW ALTERNATE MINIMUMS. VFR SHOULD RETURN BY LATE MORNING. SQUALL LINE WILL AFFECT THE TERMINALS THIS AFTERNOON...ROUGHLY FROM 20-23Z. WILL INCLUDE LOW-END MVFR CONDITIONS IN TSRA FOR NOW...BUT BRIEF STINTS AS LOW AS LIFR WILL BE POSSIBLE IN HEAVIER POCKETS OF RAIN. THE FRONT WILL CLEAR THE TERMINALS THIS EVENING...ROUGHLY 00-23Z WITH VFR CONDITIONS RETURNING THROUGH THE NIGHT AS CLEARING TAKES HOLD. EXTENDED AVIATION OUTLOOK...THERE IS A CHANCE OF SHOWERS/MVFR CONDITIONS LATE MONDAY INTO EARLY TUESDAY DUE TO ANOTHER FRONTAL SYSTEM. && .MARINE... SATELLITE AND GOES LIFR PROBABILITIES SUGGEST SEA FOG HAS MOVED INTO THE GEORGIA OFFSHORE WATERS. HAVE EXPANDED THE MARINE DENSE FOG ADVISORY TO INCLUDE THIS AREA THROUGH 10 PM. TODAY...THE RISK FOR WIDESPREAD DENSE SEA FOG WILL LINGER THROUGH MUCH OF THE MORNING HOURS AND MAY PERSIST INTO THE AFTERNOON HOURS AS WARM/MOIST AIR FLOWS OVER THE COLD SHELF WATERS. A MARINE DENSE FOG ADVISORY WILL REMAIN IN FORCE UNTIL 10 AM FOR ALL FORECAST ZONES...BUT MAY NEED TO BE EXTENDED INTO THE AFTERNOON HOURS DEPENDING ON TRENDS AND PILOT BOAT REPORTS LATER THIS MORNING. OTHERWISE...SOUTH WINDS WILL INCREASE TODAY AS A COLD FRONT DRAWS CLOSER. EXPECT WINDS TO INCREASE TO 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE WATERS. SEAS WILL BUILD AS A RESULT...RISING TO 4-7 FT NEARSHORE WATERS AND 6-8 FT OFFSHORE WATERS. A LINE OF STRONG TO SEVERE TSTMS WILL LIKELY APPROACH THE LOCAL MARINE AREA LATE IN THE AFTERNOON...ALTHOUGH A FEW STRONG SHOWERS/TSTMS MAY POP OVER THE COASTAL WATERS PRIOR TO ARRIVAL OF THE PRIMARY CONVECTIVE LINE. SPECIAL MARINE WARNINGS MAY BE NEEDED. TONIGHT...THE SQUALL LINE WILL PUSH ACROSS THE WATERS THIS EVENING AND BE FOLLOWED BY THE COLD FRONT. WINDS WILL QUICKLY SHIFT WEST WITH THE FRONT AND INCREASE WITH THE ONSET OF COLD AIR ADVECTION. WINDS LOOK TO PEAK 20-25 KT NEARSHORE WATERS AND 25-30 KT OFFSHORE WATERS. RIGHT NOW WINDS LOOK TO REMAIN BELOW GALE FORCE...ALTHOUGH A BRIEF STINT OF 35 KT WINDS WILL BE POSSIBLE. WILL MAINTAIN SMALL CRAFT ADVISORIES FOR ALL WATERS...EXCLUDING THE CHARLESTON HARBOR. OFFSHORE WINDS WILL HAVE A DECAYING EFFECT OF SEAS OVER THE NEARSHORE WATERS WITH SEAS SUBSIDING BY ABOUT 1-2 FT...BUT SEAS OF 6-8 FT WILL LINGER OVER THE OFFSHORE WATERS WHERE THE FETCH WILL BE CONSIDERABLY LONGER. SUNDAY THROUGH WEDNESDAY...LINGERING SMALL CRAFT ADVISORIES WILL BE ABLE TO END BY SUNDAY MORNING/EARLY AFTERNOON...AS SURFACE HIGH PRESSURE RAPIDLY BUILDS OVER THE REGION IN THE WAKE OF THE COLD FRONT. MARINE CONDITIONS WILL THEN REMAIN RATHER QUIET THROUGH THE DAYTIME HOURS ON MONDAY. A WAVE OF LOW PRESSURE IN THE GULF OF MEXICO WILL LIFT TOWARD THE SOUTHEAST STATES LATE MONDAY...LIKELY PULLING A COLD FRONT OFF THE COAST BY TUESDAY MORNING. EXPECT A SURGE IN SOUTHERLY WINDS AHEAD OF THE SYSTEM EARLY TUESDAY...WITH THE POTENTIAL FOR ONLY MARGINAL ADVISORY-LEVEL WINDS ACROSS PORTIONS OF THE WATERS. A MORE SOLID SURGE INTO SMALL CRAFT ADVISORY CONDITIONS WILL OCCUR WITHIN COLD ADVECTION AND WESTERLY FLOW BEHIND A SECONDARY COLD FRONT MOVING THROUGH THE AREA EARLY WEDNESDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ117-119- 139-141. SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ048>052. MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ330-350- 352-354-374. SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR AMZ352-354. SMALL CRAFT ADVISORY UNTIL 8 AM EST SUNDAY FOR AMZ350. SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ374. && $$ ST/WMS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
621 AM EST SAT JAN 11 2014 ...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING... .SYNOPSIS... A STRONG COLD FRONT WILL SWEEP ACROSS THE REGION THIS EVENING. HIGH PRESSURE WILL BUILD SUNDAY AND QUICKLY MOVE OFF THE COAST MONDAY...BEFORE ANOTHER COLD FRONT MOVES THROUGH THE AREA BY TUESDAY MORNING. HIGH PRESSURE WILL REBUILD DURING THE MIDDLE OF NEXT WEEK...WITH YET ANOTHER COLD FRONT APPROACHING BY FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... VSBYS HAVE IMPROVED ACROSS INLAND JASPER AND INLAND CHATHAM COUNTIES. THE DENSE FOG ADVISORY HAS BEEN CANCELLED FOR THESE TWO ZONES. THE ADVISORY REMAINS IN EFFECT FOR ALL COASTAL ZONES...INCLUDING TIDAL BERKELEY UNTIL 10 AM. 1 PM TO 7 PM TIMING FOR SEVERE TSTMS STILL LOOKS ON TRACK PER H3R OUTPUT. TODAY...AN ACTIVE DAY IS ON TAP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA AS A COLD FRONT APPROACHES FROM THE WEST. AHEAD OF THE FRONT...INCREASING WARM AIR ADVECTION BEING DRIVEN BY A STRONG PRE-FRONTAL LOW-LEVEL JET WILL HELP PUSH TEMPERATURES INTO THE LOWER-MID 70S FOR MOST AREAS AWAY FROM THE COAST... WHICH IS ABOUT 10-15 DEGREES ABOVE NORMAL. AS WARM AIR ADVECTION INTENSIFIES...ISOLATED TO SCATTERED SHOWERS WILL LIKELY BREAKOUT AND AFFECT PORTIONS OF THE AREA PRIOR TO THE ARRIVAL OF THE MAIN CONVECTIVE LINE. ATTM IT APPEARS THE MAIN CONVECTIVE LINE... POSSIBLY IN THE FORM OF A STRONG/SEVERE QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/...WILL REACH THE FAR WESTERN ZONES BY EARLY AFTERNOON AND REACH THE COAST BY LATE AFTERNOON OR EARLY THIS EVENING. H3R INSTABILITY PROGS AND NAM/RAP MODIFIED POINT SOUNDINGS SUGGEST SBCAPE VALUES WILL RISE TO 900-1200 J/KG WITH LIFTED INDICES DROPPING AS LOW AS -4 TO -6C. ALTHOUGH MID-LEVEL LAPSE RATES WILL BE POOR...HEALTHY 0-6KM BULK SHEAR OF 50-60 KT INDUCED BY STRONG LOW-LEVEL JETTING COUPLED WITH MODEST INSTABILITY WILL SUPPORT A RISK FOR SEVERE TSTMS WITHIN A TYPICAL MID-JANUARY HIGH SHEAR/LOW CAPE ENVIRONMENT. THE PRIMARY HAZARD RIGHT NOW LOOK TO BE DAMAGING WINDS WITH A RISK FOR ISOLATED TORNADOES WHERE DISCRETE CELLS OR EMBEDDED MESO-VORTICES WITHIN BOWING CONVECTIVE LINE SEGMENTS CAN DEVELOP. RAP 0-1KM HELICITY VALUES INCREASE TO NEAR 300 M2/S2 AND THE HIGH SHEAR/LOW CAPE SHERBS3 TORNADO PARAMETER RISES ABOVE THE BENCH MARK OF 1 UNIT FOR MUCH OF THE AREA...ALL SUGGESTING THERE IS A REASONABLE RISK FOR TORNADOES. FOR TODAY...WILL HIGHLIGHT POPS NEAR 100 PERCENT FOR ALL AREAS WITH THE HIGHEST GRIDDED POPS PLACED WITH THE EXPECTED TIMING/PLACEMENT OF THE EXPECTED CONVECTIVE LINE. HIGHS WILL BE IN THE LOWER TO MID 70S UNDER MAINLY CLOUDY SKIES. WILL INCLUDE DAMAGING WIND AND TORNADO ATTRIBUTES IN ALL GRIDDED AND TEXT PRODUCTS AND HIGHLIGHT A POTENTIAL FOR SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. THE WINDOW OF GREATEST SEVERE THREAT LOOKS TO BE 1 PM THROUGH 7 PM. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... TONIGHT...CONDITIONS WILL RAPIDLY IMPROVE THIS EVENING AS THE PRIMARY CONVECTIVE LINE PUSHES OFFSHORE AND THE COLD FRONT MOVES THROUGH. EXPECT CLEARING TO OCCUR DURING THE EVENING HOURS WITH MAINLY CLEAR SKIES DEVELOPING BY MIDNIGHT...IF NOT SOONER. LOWS WILL RANGE FROM THE LOWER 40S WELL INLAND TO THE UPPER 40S AT THE BEACHES. SUNDAY...DRY HIGH PRESSURE WILL BUILD IN THE WAKE OF THE DEPARTING COLD FRONT...YET PROGRESSIVE FLOW ALOFT WILL PULL THE CENTER OF THE HIGH QUICKLY TOWARD THE NEARBY ATLANTIC WATERS. COLD ADVECTION WILL BE WEAK BEHIND THE FRONT...AND WITH WIND DIRECTIONS REMAINING GENERALLY WEST/SOUTHWEST...EXPECT ONLY A SLIGHT COOLING TREND TO OCCUR. HIGH TEMPERATURES IN THE MID TO UPPER 60S WILL BE COOLER THAN THE PREVIOUS DAY...YET STILL BE WELL ABOVE SEASONAL NORMALS. AN AMPLIFYING LONG WAVE TROUGH ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT WILL SUPPORT BRIEF DOWNSTREAM HEIGHT RISES...AND WHEN COMBINED WITH WARM ADVECTION WITHIN BACKING LOW LEVEL FLOW...LOW TEMPERATURES IN THE UPPER 30S INLAND TO LOW 40S NEAR THE COAST WILL ALSO BE SEVERAL DEGREES WARMER THAN AVERAGE. MONDAY...SOUTHERN STREAM SHORTWAVE ENERGY TRACKING ACROSS THE GULF OF MEXICO WILL SPIN UP A SURFACE WAVE ALONG THE WESTERN PERIPHERY OF THE RETREATING ATLANTIC HIGH PRESSURE. THERE REMAINS NOTABLE DISAGREEMENT BETWEEN MODEL SOLUTIONS REGARDING THE STRENGTH AND TRACK OF THIS LOW PRESSURE WAVE AND TRAILING FRONT AS THEY PROGRESS TOWARD THE FORECAST AREA THROUGH THE DAY. IN GENERAL...A SOLID TAP INTO GULF MOISTURE WILL SUPPORT A SWATH OF PRECIPITATION ASSOCIATED WITH THE SYSTEM...AND EXPECT RAIN CHANCES TO INCREASE FROM SOUTHWEST TO NORTHEAST DURING THE LATE AFTERNOON TO EVENING TIME FRAME. WARM ADVECTION AND PRE-FRONTAL COMPRESSION WILL SUPPORT TEMPERATURES PEAKING IN THE MID TO UPPER 60S...EVEN AS CLOUD COVER GRADUALLY INCREASES. THE BEST RAIN POTENTIAL ACTUALLY APPEARS TO OCCUR OVERNIGHT INTO EARLY TUESDAY MORNING..AS THE SURFACE LOW LIFTS NORTH/NORTHEAST AND PULLS THE FRONT INTO THE REGION. LOW TEMPERATURES WILL BE QUITE MILD AS A RESULT...ONLY FALLING INTO THE UPPER 40S TO AROUND 50 DEGREES. TUESDAY...THE SYNOPTIC PATTERN REMAINS A BIT UNSETTLED EVEN AFTER THE FRONT MOVES OFFSHORE...WITH ANOTHER LARGE AREA OF UPPER LEVEL ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION. RAIN CHANCES WILL DECREASE DURING THE MORNING HOURS BEHIND THE DEPARTING COLD FRONT. HOWEVER DRY SURFACE HIGH PRESSURE IN ITS WAKE WILL BECOME SUPPRESSED TO THE SOUTH...AS YET ANOTHER FRONT DRIVEN BY THE AMPLIFYING UPPER SHORTWAVE DESCENDS FROM THE OHIO VALLEY LATE IN THE DAY. ONCE AGAIN...DOWNSLOPE FLOW AND THE LACK OF SOLID COLD ADVECTION WILL SUPPORT ABOVE NORMAL HIGH TEMPERATURES IN THE MID 60S. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE DEEPENING UPPER TROUGH WILL SHIFT OVER THE EAST COAST STATES ON WEDNESDAY...WITH A DRY COLD FRONT MOVING ACROSS THE REGION EARLY IN THE DAY. THERE APPEARS TO BE MORE NOTABLE COLD ADVECTION BEHIND THIS FRONT...AND EXPECT HIGH TEMPERATURES TO BE SUPPRESSED IN THE MID 50S UNDER MOSTLY CLEAR SKIES ON WEDNESDAY. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE THE COLDEST SEEN IN DAYS...AS LIGHT WINDS AND LITTLE TO NO CLOUD COVER SET UP IDEAL RADIATIONAL COOLING CONDITIONS. A NEARLY ZONAL UPPER PATTERN ON THURSDAY WILL BE RATHER TRANSIENT...AS BROAD TROUGHING BECOMES THE DOMINANT FEATURE ALOFT FRIDAY AND SATURDAY. CONSIDERING DRY SURFACE HIGH PRESSURE WILL ALSO SETTLE OVER THE REGION...EXPECT TEMPERATURES TO BE GENERALLY BELOW NORMAL AND RAIN CHANCES TO REMAIN BELOW 15 PERCENT THROUGH THE EXTENDED FORECAST PERIOD. && .AVIATION /11Z SATURDAY THROUGH WEDNESDAY/... FOG IS IN THE PROCESS OF LIFTING INTO VERY LOW STRATUS DECKS AT BOTH TERMINALS AS BOUNDARY LAYER WINDS INCREASE. LIFR CIGS WILL LINGER THROUGH ABOUT 14Z BEFORE SLOWLY RISING. UNTIL THEN...CIGS WILL REMAIN VERY NEAR AIRFIELD MINIMUMS AND WELL BELOW ALTERNATE MINIMUMS. VFR SHOULD RETURN BY LATE MORNING. SQUALL LINE WILL AFFECT THE TERMINALS THIS AFTERNOON...ROUGHLY FROM 20-23Z. WILL INCLUDE LOW-END MVFR CONDITIONS IN TSRA FOR NOW...BUT BRIEF STINTS AS LOW AS LIFR WILL BE POSSIBLE IN HEAVIER POCKETS OF RAIN. THE FRONT WILL CLEAR THE TERMINALS THIS EVENING...ROUGHLY 00-23Z WITH VFR CONDITIONS RETURNING THROUGH THE NIGHT AS CLEARING TAKES HOLD. EXTENDED AVIATION OUTLOOK...THERE IS A CHANCE OF SHOWERS/MVFR CONDITIONS LATE MONDAY INTO EARLY TUESDAY DUE TO ANOTHER FRONTAL SYSTEM. && .MARINE... TODAY...THE RISK FOR WIDESPREAD DENSE SEA FOG WILL LINGER THROUGH MUCH OF THE MORNING HOURS AND MAY PERSIST INTO THE AFTERNOON HOURS AS WARM/MOIST AIR FLOWS OVER THE COLD SHELF WATERS. A MARINE DENSE FOG ADVISORY WILL REMAIN IN FORCE UNTIL 10 AM FOR ALL FORECAST ZONES...BUT MAY NEED TO BE EXTENDED INTO THE AFTERNOON HOURS DEPENDING ON TRENDS AND PILOT BOAT REPORTS LATER THIS MORNING. OTHERWISE...SOUTH WINDS WILL INCREASE TODAY AS A COLD FRONT DRAWS CLOSER. EXPECT WINDS TO INCREASE TO 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE WATERS. SEAS WILL BUILD AS A RESULT...RISING TO 4-7 FT NEARSHORE WATERS AND 6-8 FT OFFSHORE WATERS. A LINE OF STRONG TO SEVERE TSTMS WILL LIKELY APPROACH THE LOCAL MARINE AREA LATE IN THE AFTERNOON...ALTHOUGH A FEW STRONG SHOWERS/TSTMS MAY POP OVER THE COASTAL WATERS PRIOR TO ARRIVAL OF THE PRIMARY CONVECTIVE LINE. SPECIAL MARINE WARNINGS MAY BE NEEDED. TONIGHT...THE SQUALL LINE WILL PUSH ACROSS THE WATERS THIS EVENING AND BE FOLLOWED BY THE COLD FRONT. WINDS WILL QUICKLY SHIFT WEST WITH THE FRONT AND INCREASE WITH THE ONSET OF COLD AIR ADVECTION. WINDS LOOK TO PEAK 20-25 KT NEARSHORE WATERS AND 25-30 KT OFFSHORE WATERS. RIGHT NOW WINDS LOOK TO REMAIN BELOW GALE FORCE...ALTHOUGH A BRIEF STINT OF 35 KT WINDS WILL BE POSSIBLE. WILL MAINTAIN SMALL CRAFT ADVISORIES FOR ALL WATERS...EXCLUDING THE CHARLESTON HARBOR. OFFSHORE WINDS WILL HAVE A DECAYING EFFECT OF SEAS OVER THE NEARSHORE WATERS WITH SEAS SUBSIDING BY ABOUT 1-2 FT...BUT SEAS OF 6-8 FT WILL LINGER OVER THE OFFSHORE WATERS WHERE THE FETCH WILL BE CONSIDERABLY LONGER. SUNDAY THROUGH WEDNESDAY...LINGERING SMALL CRAFT ADVISORIES WILL BE ABLE TO END BY SUNDAY MORNING/EARLY AFTERNOON...AS SURFACE HIGH PRESSURE RAPIDLY BUILDS OVER THE REGION IN THE WAKE OF THE COLD FRONT. MARINE CONDITIONS WILL THEN REMAIN RATHER QUIET THROUGH THE DAYTIME HOURS ON MONDAY. A WAVE OF LOW PRESSURE IN THE GULF OF MEXICO WILL LIFT TOWARD THE SOUTHEAST STATES LATE MONDAY...LIKELY PULLING A COLD FRONT OFF THE COAST BY TUESDAY MORNING. EXPECT A SURGE IN SOUTHERLY WINDS AHEAD OF THE SYSTEM EARLY TUESDAY...WITH THE POTENTIAL FOR ONLY MARGINAL ADVISORY-LEVEL WINDS ACROSS PORTIONS OF THE WATERS. A MORE SOLID SURGE INTO SMALL CRAFT ADVISORY CONDITIONS WILL OCCUR WITHIN COLD ADVECTION AND WESTERLY FLOW BEHIND A SECONDARY COLD FRONT MOVING THROUGH THE AREA EARLY WEDNESDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ117-119- 139-141. SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ048>052. MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ330-350- 352-354. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 5 AM EST SUNDAY FOR AMZ352-354. SMALL CRAFT ADVISORY UNTIL 8 AM EST SUNDAY FOR AMZ350. SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ374. && $$ ST/WMS
AREA FORECAST DISCUSSION...UPDATED
NWS CHARLESTON SC
452 AM EST SAT JAN 11 2014 ...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING... .SYNOPSIS... A STRONG COLD FRONT WILL SWEEP ACROSS THE REGION THIS EVENING. HIGH PRESSURE WILL BUILD SUNDAY AND QUICKLY MOVE OFF THE COAST MONDAY...BEFORE ANOTHER COLD FRONT MOVES THROUGH THE AREA BY TUESDAY MORNING. HIGH PRESSURE WILL REBUILD DURING THE MIDDLE OF NEXT WEEK...WITH YET ANOTHER COLD FRONT APPROACHING BY FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THROUGH SUNRISE...VISIBILITIES CONTINUE TO IMPROVE AWAY FROM THE COAST THIS MORNING AS BOUNDARY LAYER WINDS INCREASE. VISIBILITIES HAVE INCREASED ABOVE ADVISORY THRESHOLDS FOR MUCH OF THE INTERIOR... SO THE DENSE FOG ADVISORY HAS BEEN CANCELLED FOR THOSE AREAS. AT THE COAST...DENSE SEA FOG CONTINUES TO MOVE INLAND. VISIBILITIES HAVE RAPIDLY DECREASED ACROSS MUCH OF THE CHARLESTON METRO AREA OVER THE PAST HOUR AND AREA WEBCAMS SUGGEST VISIBILITIES ARE NEAR ZERO AT TIMES. OPTED TO EXPAND THE DENSE FOG ADVISORY TO INCLUDE TIDAL BERKELEY AND CHARLESTON COUNTIES TO ACCOUNT FOR GOING TRENDS. DENSE SEA FOG WILL LINGER ACROSS ALL COASTAL ZONES... INCLUDING INLAND CHATHAM AND THE SAVANNAH METRO AREA...FOR SEVERAL MORE HOURS. A POTENTIALLY ACTIVE DAY IS ON TAP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA AS A COLD FRONT APPROACHES FROM THE WEST. AHEAD OF THE FRONT...INCREASING WARM AIR ADVECTION BEING DRIVEN BY A STRONG PRE-FRONTAL LOW-LEVEL JET WILL HELP PUSH TEMPERATURES INTO THE LOWER TO MID 70S FOR MOST AREAS AWAY FROM THE COAST... WHICH IS ABOUT 10-15 DEGREES ABOVE NORMAL. AS WARM AIR ADVECTION INTENSIFIES...ISOLATED TO SCATTERED SHOWERS WILL LIKELY BREAKOUT AND AFFECT PORTIONS OF THE AREA PRIOR TO THE ARRIVAL OF THE MAIN CONVECTIVE LINE. ATTM IT APPEARS THE MAIN CONVECTIVE LINE...POSSIBLY IN THE FORM OF A STRONG/SEVERE QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/...WILL REACH THE FAR WESTERN ZONES BY EARLY AFTERNOON AND REACH THE COAST BY LATE AFTERNOON OR EARLY THIS EVENING. INSTABILITY PROGS AND MODIFIED POINT SOUNDINGS SUGGEST SBCAPE VALUES WILL RISE TO 800-1000 J/KG WITH LIFTED INDICES DROPPING AS LOW AS -4C. ALTHOUGH MID-LEVEL LAPSE RATES WILL BE POOR...HEALTHY 0-6KM BULK SHEAR OF 50-60 KT INDUCED BY STRONG LOW-LEVEL JETTING COUPLED WITH MODEST INSTABILITY WILL SUPPORT A RISK FOR SEVERE TSTMS WITHIN A TYPICAL MID-JANUARY HIGH SHEAR/LOW CAPE ENVIRONMENT. THE PRIMARY HAZARD RIGHT NOW LOOK TO BE DAMAGING WINDS WITH A RISK FOR ISOLATED TORNADOES WHERE DISCRETE CELLS OR EMBEDDED MESO-VORTICES WITHIN BOWING CONVECTIVE SEGMENTS CAN DEVELOP. RAP 0-1KM HELICITY VALUES INCREASE TO NEAR 300 M2/S2 AND THE HIGH SHEAR/LOW CAPE SHERBS3 TORNADO PARAMETER RISES ABOVE THE BENCH MARK OF 1 UNIT FOR MUCH OF THE AREA...ALL SUGGESTING THERE IS A REASONABLE RISK FOR TORNADOES. FOR TODAY...WILL HIGHLIGHT POPS NEAR 100 PERCENT FOR ALL AREAS WITH THE HIGHEST GRIDDED POPS PLACED WITH THE EXPECTED TIMING/PLACEMENT OF THE EXPECTED CONVECTIVE LINE. HIGHS WILL BE IN THE LOWER TO MID 70S UNDER MAINLY CLOUDY SKIES. WILL INCLUDE DAMAGING WIND AND TORNADO ATTRIBUTES IN ALL GRIDDED AND TEXT PRODUCTS AND HIGHLIGHT A POTENTIAL FOR SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. THE WINDOW OF GREATEST SEVERE THREAT LOOKS TO BE 1 PM THROUGH 7 PM. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... TONIGHT...CONDITIONS WILL RAPIDLY IMPROVE THIS EVENING AS THE PRIMARY CONVECTIVE LINE PUSHES OFFSHORE AND THE COLD FRONT MOVES THROUGH. EXPECT CLEARING TO OCCUR DURING THE EVENING HOURS WITH MAINLY CLEAR SKIES DEVELOPING BY MIDNIGHT...IF NOT SOONER. LOWS WILL RANGE FROM THE LOWER 40S WELL INLAND TO THE UPPER 40S AT THE BEACHES. SUNDAY...DRY HIGH PRESSURE WILL BUILD IN THE WAKE OF THE DEPARTING COLD FRONT...YET PROGRESSIVE FLOW ALOFT WILL PULL THE CENTER OF THE HIGH QUICKLY TOWARD THE NEARBY ATLANTIC WATERS. COLD ADVECTION WILL BE WEAK BEHIND THE FRONT...AND WITH WIND DIRECTIONS REMAINING GENERALLY WEST/SOUTHWEST...EXPECT ONLY A SLIGHT COOLING TREND TO OCCUR. HIGH TEMPERATURES IN THE MID TO UPPER 60S WILL BE COOLER THAN THE PREVIOUS DAY...YET STILL BE WELL ABOVE SEASONAL NORMALS. AN AMPLIFYING LONG WAVE TROUGH ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT WILL SUPPORT BRIEF DOWNSTREAM HEIGHT RISES...AND WHEN COMBINED WITH WARM ADVECTION WITHIN BACKING LOW LEVEL FLOW...LOW TEMPERATURES IN THE UPPER 30S INLAND TO LOW 40S NEAR THE COAST WILL ALSO BE SEVERAL DEGREES WARMER THAN AVERAGE. MONDAY...SOUTHERN STREAM SHORTWAVE ENERGY TRACKING ACROSS THE GULF OF MEXICO WILL SPIN UP A SURFACE WAVE ALONG THE WESTERN PERIPHERY OF THE RETREATING ATLANTIC HIGH PRESSURE. THERE REMAINS NOTABLE DISAGREEMENT BETWEEN MODEL SOLUTIONS REGARDING THE STRENGTH AND TRACK OF THIS LOW PRESSURE WAVE AND TRAILING FRONT AS THEY PROGRESS TOWARD THE FORECAST AREA THROUGH THE DAY. IN GENERAL...A SOLID TAP INTO GULF MOISTURE WILL SUPPORT A SWATH OF PRECIPITATION ASSOCIATED WITH THE SYSTEM...AND EXPECT RAIN CHANCES TO INCREASE FROM SOUTHWEST TO NORTHEAST DURING THE LATE AFTERNOON TO EVENING TIME FRAME. WARM ADVECTION AND PRE-FRONTAL COMPRESSION WILL SUPPORT TEMPERATURES PEAKING IN THE MID TO UPPER 60S...EVEN AS CLOUD COVER GRADUALLY INCREASES. THE BEST RAIN POTENTIAL ACTUALLY APPEARS TO OCCUR OVERNIGHT INTO EARLY TUESDAY MORNING..AS THE SURFACE LOW LIFTS NORTH/NORTHEAST AND PULLS THE FRONT INTO THE REGION. LOW TEMPERATURES WILL BE QUITE MILD AS A RESULT...ONLY FALLING INTO THE UPPER 40S TO AROUND 50 DEGREES. TUESDAY...THE SYNOPTIC PATTERN REMAINS A BIT UNSETTLED EVEN AFTER THE FRONT MOVES OFFSHORE...WITH ANOTHER LARGE AREA OF UPPER LEVEL ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION. RAIN CHANCES WILL DECREASE DURING THE MORNING HOURS BEHIND THE DEPARTING COLD FRONT. HOWEVER DRY SURFACE HIGH PRESSURE IN ITS WAKE WILL BECOME SUPPRESSED TO THE SOUTH...AS YET ANOTHER FRONT DRIVEN BY THE AMPLIFYING UPPER SHORTWAVE DESCENDS FROM THE OHIO VALLEY LATE IN THE DAY. ONCE AGAIN...DOWNSLOPE FLOW AND THE LACK OF SOLID COLD ADVECTION WILL SUPPORT ABOVE NORMAL HIGH TEMPERATURES IN THE MID 60S. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE DEEPENING UPPER TROUGH WILL SHIFT OVER THE EAST COAST STATES ON WEDNESDAY...WITH A DRY COLD FRONT MOVING ACROSS THE REGION EARLY IN THE DAY. THERE APPEARS TO BE MORE NOTABLE COLD ADVECTION BEHIND THIS FRONT...AND EXPECT HIGH TEMPERATURES TO BE SUPPRESSED IN THE MID 50S UNDER MOSTLY CLEAR SKIES ON WEDNESDAY. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE THE COLDEST SEEN IN DAYS...AS LIGHT WINDS AND LITTLE TO NO CLOUD COVER SET UP IDEAL RADIATIONAL COOLING CONDITIONS. A NEARLY ZONAL UPPER PATTERN ON THURSDAY WILL BE RATHER TRANSIENT...AS BROAD TROUGHING BECOMES THE DOMINANT FEATURE ALOFT FRIDAY AND SATURDAY. CONSIDERING DRY SURFACE HIGH PRESSURE WILL ALSO SETTLE OVER THE REGION...EXPECT TEMPERATURES TO BE GENERALLY BELOW NORMAL AND RAIN CHANCES TO REMAIN BELOW 15 PERCENT THROUGH THE EXTENDED FORECAST PERIOD. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... HIGH POTENTIAL FOR DENSE FOG AT BOTH TERMINALS OVERNIGHT...BUT THE DURATION AND TIMING REMAINS IN QUESTION. KSAV HAS ALREADY DROPPED TO 1/4 MILE BUT HAS BEEN JUMPING OVER THE PAST HOUR. SUSPECT THIS IS TEMPORARY WITH OBSERVATIONS TO THE SOUTH SHOWING STEADIER DENSE FOG TRENDS. AT KCHS...CIGS SHOULD CONTINUE TO LOWER OVER THE NEXT FEW HOURS...BUT THINK THE FOG RISK MAY BE SOMEWHAT LOWER HERE GIVEN SLIGHTLY HIGHER BOUNDARY LAYER FLOW FORECAST. STILL...DENSE SEA FOG IS MOVING SLOWLY INLAND ALONG THE CHARLESTON COUNTY COAST AND MAY EVENTUALLY ENVELOP KCHS PRIOR TO DAY BREAK. WILL CALL FOR PREVAILING LIFR AT KSAV 09-13Z AND PREVAILING MVFR WITH TEMPO LIFR AT KCHS TO TREND. CONDITIONS WILL SLOWLY IMPROVE DURING THE MORNING HOURS AS A COLD FRONT APPROACHES. A LINE OF SHOWERS...POSSIBLY IN THE FORM OF A SQUALL LINE...WILL MOVE ACROSS THE TERMINALS THIS AFTERNOON...ROUGHLY 20-23Z. WILL NOT INCLUDE TSRA JUST YET...BUT WILL SHOW PREVAILING LOW-END MVFR VSBYS AND CIGS IN HEAVY RAIN. WESTERLY WINDS AND SLOWLY IMPROVING CONDITIONS WILL OCCUR THIS EVENING. EXTENDED AVIATION OUTLOOK...EXPECT COLD FRONTAL PASSAGE THIS EVENING. CONDITIONS WILL BECOME VFR TONIGHT...WITH GUSTY WEST WINDS THROUGH SUNDAY MORNING. THERE IS A CHANCE OF SHOWERS/MVFR CONDITIONS LATE MONDAY INTO EARLY TUESDAY DUE TO ANOTHER FRONTAL SYSTEM. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL THROUGH WEDNESDAY. && .MARINE... TODAY...THE RISK FOR WIDESPREAD DENSE SEA FOG WILL LINGER THROUGH MUCH OF THE MORNING HOURS AND MAY PERSIST INTO THE AFTERNOON HOURS AS WARM/MOIST AIR FLOWS OVER THE COLD SHELF WATERS. A MARINE DENSE FOG ADVISORY WILL REMAIN IN FORCE UNTIL 10 AM FOR ALL FORECAST ZONES...BUT MAY NEED TO BE EXTENDED INTO THE AFTERNOON HOURS DEPENDING ON TRENDS AND PILOT BOAT REPORTS LATER THIS MORNING. OTHERWISE...SOUTH WINDS WILL INCREASE TODAY AS A COLD FRONT DRAWS CLOSER. EXPECT WINDS TO INCREASE TO 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE WATERS. SEAS WILL BUILD AS A RESULT...RISING TO 4-7 FT NEARSHORE WATERS AND 6-8 FT OFFSHORE WATERS. A LINE OF STRONG TO SEVERE TSTMS WILL LIKELY APPROACH THE LOCAL MARINE AREA LATE IN THE AFTERNOON...ALTHOUGH A FEW STRONG SHOWERS/TSTMS MAY POP OVER THE COASTAL WATERS PRIOR TO ARRIVAL OF THE PRIMARY CONVECTIVE LINE. SPECIAL MARINE WARNINGS MAY BE NEEDED. TONIGHT...THE SQUALL LINE WILL PUSH ACROSS THE WATERS THIS EVENING AND BE FOLLOWED BY THE COLD FRONT. WINDS WILL QUICKLY SHIFT WEST WITH THE FRONT AND INCREASE WITH THE ONSET OF COLD AIR ADVECTION. WINDS LOOK TO PEAK 20-25 KT NEARSHORE WATERS AND 25-30 KT OFFSHORE WATERS. RIGHT NOW WINDS LOOK TO REMAIN BELOW GALE FORCE...ALTHOUGH A BRIEF STINT OF 35 KT WINDS WILL BE POSSIBLE. WILL MAINTAIN SMALL CRAFT ADVISORIES FOR ALL WATERS...EXCLUDING THE CHARLESTON HARBOR. OFFSHORE WINDS WILL HAVE A DECAYING EFFECT OF SEAS OVER THE NEARSHORE WATERS WITH SEAS SUBSIDING BY ABOUT 1-2 FT...BUT SEAS OF 6-8 FT WILL LINGER OVER THE OFFSHORE WATERS WHERE THE FETCH WILL BE CONSIDERABLY LONGER. SUNDAY THROUGH WEDNESDAY...LINGERING SMALL CRAFT ADVISORIES WILL BE ABLE TO END BY SUNDAY MORNING/EARLY AFTERNOON...AS SURFACE HIGH PRESSURE RAPIDLY BUILDS OVER THE REGION IN THE WAKE OF THE COLD FRONT. MARINE CONDITIONS WILL THEN REMAIN RATHER QUIET THROUGH THE DAYTIME HOURS ON MONDAY. A WAVE OF LOW PRESSURE IN THE GULF OF MEXICO WILL LIFT TOWARD THE SOUTHEAST STATES LATE MONDAY...LIKELY PULLING A COLD FRONT OFF THE COAST BY TUESDAY MORNING. EXPECT A SURGE IN SOUTHERLY WINDS AHEAD OF THE SYSTEM EARLY TUESDAY...WITH THE POTENTIAL FOR ONLY MARGINAL ADVISORY-LEVEL WINDS ACROSS PORTIONS OF THE WATERS. A MORE SOLID SURGE INTO SMALL CRAFT ADVISORY CONDITIONS WILL OCCUR WITHIN COLD ADVECTION AND WESTERLY FLOW BEHIND A SECONDARY COLD FRONT MOVING THROUGH THE AREA EARLY WEDNESDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ117>119- 139-141. SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ047>052. MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ330-350- 352-354. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 5 AM EST SUNDAY FOR AMZ352-354. SMALL CRAFT ADVISORY UNTIL 8 AM EST SUNDAY FOR AMZ350. SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ374. && $$ ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
358 AM EST SAT JAN 11 2014 ...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING... .SYNOPSIS... A STRONG COLD FRONT WILL SWEEP ACROSS THE REGION THIS EVENING. HIGH PRESSURE WILL BUILD SUNDAY AND QUICKLY MOVE OFF THE COAST MONDAY...BEFORE ANOTHER COLD FRONT MOVES THROUGH THE AREA BY TUESDAY MORNING. HIGH PRESSURE WILL REBUILD DURING THE MIDDLE OF NEXT WEEK...WITH YET ANOTHER COLD FRONT APPROACHING BY FRIDAY. && .NEAR TERM /THROUGH TODAY/... THROUGH SUNRISE...AREAS OF DENSE FOG HAVE DEVELOPED ACROSS A GOOD PORTION OF THE FORECAST AREA EARLY THIS MORNING...WHILE SEA FOG IMPACTS THE COASTAL AREAS. BOUNDARY LAYER WINDS ARE PROGGED TO INCREASE OVER THE NEXT FEW HOURS...WHICH MAY LEAD TO IMPROVING VISIBILITIES PRIOR TO SUNRISE. IN FACT...VISIBILITIES ARE ALREADY STARTING TO IMPROVE SLIGHTLY SOUTH OF I-16...WHICH MAY BE THE BEGINNING OF A MORE SUSTAINED TREND. WILL CONTINUE TO MONITOR VISIBILITIES OVER THE NEXT FEW HOURS AND IT IS CERTAINLY POSSIBLE THAT PORTIONS OF THE DENSE FOG ADVISORY COULD BE CANCELLED EARLY. AT THE COAST...SEA FOG WILL NOT BE AS EASILY MOVED BY THE INCREASING BOUNDARY LAYER FLOW AND WE ARE MONITORING FOR A POSSIBLE EXPANSION OF THE DENSE FOG ADVISORY INTO CHARLESTON COUNTY WHERE COASTAL WEBCAMS SHOW VERY DENSE FOG...MAINLY EAST OF HIGHWAY 17. A POTENTIALLY ACTIVE DAY IS ON TAP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA AS A COLD FRONT APPROACHES FROM THE WEST. AHEAD OF THE FRONT...INCREASING WARM AIR ADVECTION BEING DRIVEN BY A STRONG PRE-FRONTAL LOW-LEVEL JET WILL HELP PUSH TEMPERATURES INTO THE LOWER TO MID 70S FOR MOST AREAS AWAY FROM THE COAST... WHICH IS ABOUT 10-15 DEGREES ABOVE NORMAL. AS WARM AIR ADVECTION INTENSIFIES...ISOLATED TO SCATTERED SHOWERS WILL LIKELY BREAKOUT AND AFFECT PORTIONS OF THE AREA PRIOR TO THE ARRIVAL OF THE MAIN CONVECTIVE LINE. ATTM IT APPEARS THE MAIN CONVECTIVE LINE...POSSIBLY IN THE FORM OF A STRONG/SEVERE QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/...WILL REACH THE FAR WESTERN ZONES BY EARLY AFTERNOON AND REACH THE COAST BY LATE AFTERNOON OR EARLY THIS EVENING. INSTABILITY PROGS AND MODIFIED POINT SOUNDINGS SUGGEST SBCAPE VALUES WILL RISE TO 800-1000 J/KG WITH LIFTED INDICES DROPPING AS LOW AS -4C. ALTHOUGH MID-LEVEL LAPSE RATES WILL BE POOR...HEALTHY 0-6KM BULK SHEAR OF 50-60 KT INDUCED BY STRONG LOW-LEVEL JETTING COUPLED WITH MODEST INSTABILITY WILL SUPPORT A RISK FOR SEVERE TSTMS WITHIN A TYPICAL MID-JANUARY HIGH SHEAR/LOW CAPE ENVIRONMENT. THE PRIMARY HAZARD RIGHT NOW LOOK TO BE DAMAGING WINDS WITH A RISK FOR ISOLATED TORNADOES WHERE DISCRETE CELLS OR EMBEDDED MESO-VORTICES WITHIN BOWING CONVECTIVE SEGMENTS CAN DEVELOP. RAP 0-1KM HELICITY VALUES INCREASE TO NEAR 300 M2/S2 AND THE HIGH SHEAR/LOW CAPE SHERBS3 TORNADO PARAMETER RISES ABOVE THE BENCH MARK OF 1 UNIT FOR MUCH OF THE AREA...ALL SUGGESTING THERE IS A REASONABLE RISK FOR TORNADOES. FOR TODAY...WILL HIGHLIGHT POPS NEAR 100 PERCENT FOR ALL AREAS WITH THE HIGHEST GRIDDED POPS PLACED WITH THE EXPECTED TIMING/PLACEMENT OF THE EXPECTED CONVECTIVE LINE. HIGHS WILL BE IN THE LOWER TO MID 70S UNDER MAINLY CLOUDY SKIES. WILL INCLUDE DAMAGING WIND AND TORNADO ATTRIBUTES IN ALL GRIDDED AND TEXT PRODUCTS AND HIGHLIGHT A POTENTIAL FOR SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. THE WINDOW OF GREATEST SEVERE THREAT LOOKS TO BE 1 PM THROUGH 7 PM. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... TONIGHT...CONDITIONS WILL RAPIDLY IMPROVE THIS EVENING AS THE PRIMARY CONVECTIVE LINE PUSHES OFFSHORE AND THE COLD FRONT MOVES THROUGH. EXPECT CLEARING TO OCCUR DURING THE EVENING HOURS WITH MAINLY CLEAR SKIES DEVELOPING BY MIDNIGHT...IF NOT SOONER. LOWS WILL RANGE FROM THE LOWER 40S WELL INLAND TO THE UPPER 40S AT THE BEACHES. SUNDAY...DRY HIGH PRESSURE WILL BUILD IN THE WAKE OF THE DEPARTING COLD FRONT...YET PROGRESSIVE FLOW ALOFT WILL PULL THE CENTER OF THE HIGH QUICKLY TOWARD THE NEARBY ATLANTIC WATERS. COLD ADVECTION WILL BE WEAK BEHIND THE FRONT...AND WITH WIND DIRECTIONS REMAINING GENERALLY WEST/SOUTHWEST...EXPECT ONLY A SLIGHT COOLING TREND TO OCCUR. HIGH TEMPERATURES IN THE MID TO UPPER 60S WILL BE COOLER THAN THE PREVIOUS DAY...YET STILL BE WELL ABOVE SEASONAL NORMALS. AN AMPLIFYING LONG WAVE TROUGH ACROSS THE CENTRAL PLAINS AFTER MIDNIGHT WILL SUPPORT BRIEF DOWNSTREAM HEIGHT RISES...AND WHEN COMBINED WITH WARM ADVECTION WITHIN BACKING LOW LEVEL FLOW...LOW TEMPERATURES IN THE UPPER 30S INLAND TO LOW 40S NEAR THE COAST WILL ALSO BE SEVERAL DEGREES WARMER THAN AVERAGE. MONDAY...SOUTHERN STREAM SHORTWAVE ENERGY TRACKING ACROSS THE GULF OF MEXICO WILL SPIN UP A SURFACE WAVE ALONG THE WESTERN PERIPHERY OF THE RETREATING ATLANTIC HIGH PRESSURE. THERE REMAINS NOTABLE DISAGREEMENT BETWEEN MODEL SOLUTIONS REGARDING THE STRENGTH AND TRACK OF THIS LOW PRESSURE WAVE AND TRAILING FRONT AS THEY PROGRESS TOWARD THE FORECAST AREA THROUGH THE DAY. IN GENERAL...A SOLID TAP INTO GULF MOISTURE WILL SUPPORT A SWATH OF PRECIPITATION ASSOCIATED WITH THE SYSTEM...AND EXPECT RAIN CHANCES TO INCREASE FROM SOUTHWEST TO NORTHEAST DURING THE LATE AFTERNOON TO EVENING TIME FRAME. WARM ADVECTION AND PRE-FRONTAL COMPRESSION WILL SUPPORT TEMPERATURES PEAKING IN THE MID TO UPPER 60S...EVEN AS CLOUD COVER GRADUALLY INCREASES. THE BEST RAIN POTENTIAL ACTUALLY APPEARS TO OCCUR OVERNIGHT INTO EARLY TUESDAY MORNING..AS THE SURFACE LOW LIFTS NORTH/NORTHEAST AND PULLS THE FRONT INTO THE REGION. LOW TEMPERATURES WILL BE QUITE MILD AS A RESULT...ONLY FALLING INTO THE UPPER 40S TO AROUND 50 DEGREES. TUESDAY...THE SYNOPTIC PATTERN REMAINS A BIT UNSETTLED EVEN AFTER THE FRONT MOVES OFFSHORE...WITH ANOTHER LARGE AREA OF UPPER LEVEL ENERGY SWEEPING SOUTHEAST FROM THE GREAT LAKES REGION. RAIN CHANCES WILL DECREASE DURING THE MORNING HOURS BEHIND THE DEPARTING COLD FRONT. HOWEVER DRY SURFACE HIGH PRESSURE IN ITS WAKE WILL BECOME SUPPRESSED TO THE SOUTH...AS YET ANOTHER FRONT DRIVEN BY THE AMPLIFYING UPPER SHORTWAVE DESCENDS FROM THE OHIO VALLEY LATE IN THE DAY. ONCE AGAIN...DOWNSLOPE FLOW AND THE LACK OF SOLID COLD ADVECTION WILL SUPPORT ABOVE NORMAL HIGH TEMPERATURES IN THE MID 60S. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... THE DEEPENING UPPER TROUGH WILL SHIFT OVER THE EAST COAST STATES ON WEDNESDAY...WITH A DRY COLD FRONT MOVING ACROSS THE REGION EARLY IN THE DAY. THERE APPEARS TO BE MORE NOTABLE COLD ADVECTION BEHIND THIS FRONT...AND EXPECT HIGH TEMPERATURES TO BE SUPPRESSED IN THE MID 50S UNDER MOSTLY CLEAR SKIES ON WEDNESDAY. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE THE COLDEST SEEN IN DAYS...AS LIGHT WINDS AND LITTLE TO NO CLOUD COVER SET UP IDEAL RADIATIONAL COOLING CONDITIONS. A NEARLY ZONAL UPPER PATTERN ON THURSDAY WILL BE RATHER TRANSIENT...AS BROAD TROUGHING BECOMES THE DOMINANT FEATURE ALOFT FRIDAY AND SATURDAY. CONSIDERING DRY SURFACE HIGH PRESSURE WILL ALSO SETTLE OVER THE REGION...EXPECT TEMPERATURES TO BE GENERALLY BELOW NORMAL AND RAIN CHANCES TO REMAIN BELOW 15 PERCENT THROUGH THE EXTENDED FORECAST PERIOD. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... HIGH POTENTIAL FOR DENSE FOG AT BOTH TERMINALS OVERNIGHT...BUT THE DURATION AND TIMING REMAINS IN QUESTION. KSAV HAS ALREADY DROPPED TO 1/4 MILE BUT HAS BEEN JUMPING OVER THE PAST HOUR. SUSPECT THIS IS TEMPORARY WITH OBSERVATIONS TO THE SOUTH SHOWING STEADIER DENSE FOG TRENDS. AT KCHS...CIGS SHOULD CONTINUE TO LOWER OVER THE NEXT FEW HOURS...BUT THINK THE FOG RISK MAY BE SOMEWHAT LOWER HERE GIVEN SLIGHTLY HIGHER BOUNDARY LAYER FLOW FORECAST. STILL...DENSE SEA FOG IS MOVING SLOWLY INLAND ALONG THE CHARLESTON COUNTY COAST AND MAY EVENTUALLY ENVELOP KCHS PRIOR TO DAY BREAK. WILL CALL FOR PREVAILING LIFR AT KSAV 09-13Z AND PREVAILING MVFR WITH TEMPO LIFR AT KCHS TO TREND. CONDITIONS WILL SLOWLY IMPROVE DURING THE MORNING HOURS AS A COLD FRONT APPROACHES. A LINE OF SHOWERS...POSSIBLY IN THE FORM OF A SQUALL LINE...WILL MOVE ACROSS THE TERMINALS THIS AFTERNOON...ROUGHLY 20-23Z. WILL NOT INCLUDE TSRA JUST YET...BUT WILL SHOW PREVAILING LOW-END MVFR VSBYS AND CIGS IN HEAVY RAIN. WESTERLY WINDS AND SLOWLY IMPROVING CONDITIONS WILL OCCUR THIS EVENING. EXTENDED AVIATION OUTLOOK...EXPECT COLD FRONTAL PASSAGE THIS EVENING. CONDITIONS WILL BECOME VFR TONIGHT...WITH GUSTY WEST WINDS THROUGH SUNDAY MORNING. THERE IS A CHANCE OF SHOWERS/MVFR CONDITIONS LATE MONDAY INTO EARLY TUESDAY DUE TO ANOTHER FRONTAL SYSTEM. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL THROUGH WEDNESDAY. && .MARINE... TODAY...THE RISK FOR DENSE SEA FOG WILL LINGER THROUGH MUCH OF THE MORNING HOURS AND MAY PERSIST INTO THE AFTERNOON HOURS AS WARM/MOIST AIR FLOWS OVER THE COLD SHELF WATERS. A MARINE DENSE FOG ADVISORY WILL REMAIN IN FORCE UNTIL 10 AM FOR ALL FORECAST ZONES...BUT MAY NEED TO BE EXTENDED INTO THE AFTERNOON HOURS DEPENDING ON TRENDS AND PILOT BOAT REPORTS LATER THIS MORNING. OTHERWISE...SOUTH WINDS WILL INCREASE TODAY AS A COLD FRONT DRAWS CLOSER. EXPECT WINDS TO INCREASE TO 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE WATERS. SEAS WILL BUILD AS A RESULT...RISING TO 4-7 FT NEARSHORE WATERS AND 6-8 FT OFFSHORE WATERS. A LINE OF STRONG TO SEVERE TSTMS WILL LIKELY APPROACH THE LOCAL MARINE AREA LATE IN THE AFTERNOON...ALTHOUGH A FEW STRONG SHOWERS/TSTMS MAY POP OVER THE COASTAL WATERS PRIOR TO ARRIVAL OF THE PRIMARY CONVECTIVE LINE. SPECIAL MARINE WARNINGS MAY BE NEEDED. TONIGHT...THE SQUALL LINE WILL PUSH ACROSS THE WATERS THIS EVENING AND BE FOLLOWED BY THE COLD FRONT. WINDS WILL QUICKLY SHIFT WEST WITH THE FRONT AND INCREASE WITH THE ONSET OF COLD AIR ADVECTION. WINDS LOOK TO PEAK 20-25 KT NEARSHORE WATERS AND 25-30 KT OFFSHORE WATERS. RIGHT NOW WINDS LOOK TO REMAIN BELOW GALE FORCE...ALTHOUGH A BRIEF STINT OF 35 KT WINDS WILL BE POSSIBLE. WILL MAINTAIN SMALL CRAFT ADVISORIES FOR ALL WATERS...EXCLUDING THE CHARLESTON HARBOR. OFFSHORE WINDS WILL HAVE A DECAYING EFFECT OF SEAS OVER THE NEARSHORE WATERS WITH SEAS SUBSIDING BY ABOUT 1-2 FT...BUT SEAS OF 6-8 FT WILL LINGER OVER THE OFFSHORE WATERS WHERE THE FETCH WILL BE CONSIDERABLY LONGER. SUNDAY THROUGH WEDNESDAY...LINGERING SMALL CRAFT ADVISORIES WILL BE ABLE TO END BY SUNDAY MORNING/EARLY AFTERNOON...AS SURFACE HIGH PRESSURE RAPIDLY BUILDS OVER THE REGION IN THE WAKE OF THE COLD FRONT. MARINE CONDITIONS WILL THEN REMAIN RATHER QUIET THROUGH THE DAYTIME HOURS ON MONDAY. A WAVE OF LOW PRESSURE IN THE GULF OF MEXICO WILL LIFT TOWARD THE SOUTHEAST STATES LATE MONDAY...LIKELY PULLING A COLD FRONT OFF THE COAST BY TUESDAY MORNING. EXPECT A SURGE IN SOUTHERLY WINDS AHEAD OF THE SYSTEM EARLY TUESDAY...WITH THE POTENTIAL FOR ONLY MARGINAL ADVISORY-LEVEL WINDS ACROSS PORTIONS OF THE WATERS. A MORE SOLID SURGE INTO SMALL CRAFT ADVISORY CONDITIONS WILL OCCUR WITHIN COLD ADVECTION AND WESTERLY FLOW BEHIND A SECONDARY COLD FRONT MOVING THROUGH THE AREA EARLY WEDNESDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ087-088- 099>101-114>119-137>141. SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ040-042- 043-047>049-051. MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ330-350- 352-354. SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 5 AM EST SUNDAY FOR AMZ352-354. SMALL CRAFT ADVISORY UNTIL 8 AM EST SUNDAY FOR AMZ350. SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ374. && $$ ST/WMS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
242 AM EST SAT JAN 11 2014 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA THIS AFTERNOON. HIGH PRESSURE BEHIND THE FRONT WILL BE OVER OUR REGION SUNDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY NIGHT. ANOTHER COLD FRONT WILL MOVE INTO THE AREA MONDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... HIGH LOW-LEVEL MOISTURE AND CONVERGENCE NEAR THE WEDGE/WARM FRONT HAS RESULTED IN WIDESPREAD FOG THIS MORNING. THERE WERE AREAS OF DENSE FOG AND WE HAVE ISSUED A DENSE FOG ADVISORY. THE HRRR MAINTAINS FOG OVER MUCH OF THE AREA THROUGH 1000 AM. THE FOG WILL LIKELY DIMINISH AS DEEPER MOISTURE AND INCREASED MIXING ASSOCIATED WITH THE FRONT NEARS THE AREA LATER THIS MORNING. HIGH MOISTURE ASSOCIATED WITH THE STRONG H85 JET AND LIFT WITH THE RIGHT ENTRANCE REGION OF THE H25 JET PLUS CONVERGENCE ALONG THE COLD FRONT SUPPORT CATEGORICAL POPS TODAY. THE NAM AND GFS ARE CLOSE WITH GENERAL RAINFALL TOTALS AROUND 0.6 OF AN INCH...BUT WITH PRECIPITABLE WATER NEAR 1.6 OF AN INCH HEAVIER AMOUNTS WILL LIKELY OCCUR IN SOME LOCATIONS. THE NAM DISPLAYS SURFACE-BASED LI/S LOWERING TO -1 TO -2 THIS AFTERNOON. THE INSTABILITY IS QUESTIONABLE BECAUSE IT SHOULD BE LIMITED BY FOG EARLY AND THEN WIDESPREAD SHOWERS. HOWEVER...IF SURFACE-BASED INSTABILITY DOES DEVELOP THEN SEVERE THUNDERSTORMS MAY OCCUR BECAUSE OF STRONG SHEAR. THE NAM AND GFS HAVE H85 WINDS NEAR 60 KNOTS. THE MAIN THREAT IS DAMAGING STRAIGHT-LINE WINDS BUT FORECAST HODOGRAPHS ALSO SUPPORT POSSIBLE TORNADOES. THE 03Z HRRR SHOWS THE MAIN CONVECTIVE LINE ABOUT TO ENTER THE WEST PART OF THE FORECAST AREA AT 100 PM. THIS MODEL ALSO SHOWS DEVELOPMENT AHEAD OF THIS LINE FARTHER SOUTH IN COASTAL GEORGIA WHICH MAY TEND TO LIMIT THE TRANSPORT OF MOISTURE AND INSTABILITY FARTHER NORTH AND INTO THE FORECAST AREA. THE 00Z SPC WRF DISPLAYS THE MAIN CONVECTIVE LINE IN THE FORECAST AREA DURING THE 300 PM TO 700 PM TIME FRAME...BUT THIS CONVECTION APPEARS TO WEAKEN AS UPSTREAM DEVELOPMENT NEAR THE COAST BECOMES MORE DOMINATE. WE USED THE COOLER TEMPERATURE GUIDANCE TODAY BECAUSE OF CLOUDINESS AND SHOWERS. && .SHORT TERM /TONIGHT THROUGH MONDAY/... DRYING WILL OCCUR BEHIND THE FRONT TONIGHT. THE SHOWER CHANCE WILL DECREASE RAPIDLY FROM WEST TO EAST DURING THE EVENING. HIGH PRESSURE WILL BE OVER THE FORECAST AREA SUNDAY. THE HIGH WILL MOVE OFF THE COAST SUNDAY NIGHT. THE TEMPERATURE GUIDANCE WAS CONSISTENT. TEMPERATURES WILL BE ABOVE NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... THE GFS AND ECMWF DISPLAY MOISTURE ASSOCIATED WITH A COLD FRONT MONDAY NIGHT INTO TUESDAY. THE ECMWF CONTINUES TO INDICATE MORE MOISTURE COMPARED TO THE GFS. CONTINUED CHANCE POPS BECAUSE OF THE MODEL INCONSISTENCY. EXPECT A REINFORCING COLD FRONT WITH LIMITED MOISTURE WEDNESDAY. THE MODELS SHOW DRY RIDGING DOMINATING THURSDAY WITH YET ANOTHER COLD FRONT WILL LITTLE MOISTURE FRIDAY. ABOVE NORMAL TEMPERATURES SHOULD OCCUR AHEAD OF THE FRONT TUESDAY...WITH COOLING TO NEAR OR SLIGHTLY BELOW NORMAL BY THURSDAY. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... RESTRICTIONS DOMINATING THROUGH 12/00Z THEN CONDITIONS IMPROVING. SHOWERS HAVE DIMINISHED ACROSS THE TAF SITES...HOWEVER WITH CALM WINDS CIGS AND VSBYS HAVE LOWERED INTO THE LIFR RANGE. EXPECT CONDITIONS TO REMAIN LIFR THROUGH 13Z WHEN THE PRESSURE GRADIENT AHEAD OF THE COLD FRONT WILL INCREASE WINDS AND IMPROVE CIGS AND VSBYS TO IFR RANGE. COLD FRONT WILL MOVE INTO THE TAF SITES DURING THE MORNING ALONG WITH SHOWERS AND GUSTY WINDS. CONFIDENCE IN THUNDERSTORMS CONTINUES TO INCREASE...HOWEVER TIMING CONFIDENCE IS TOO LOW TO INCLUDE IN TAFS ATTM. BEST POTENTIAL FOR THUNDERSTORMS WILL BE 16Z THROUGH 22Z. CONDITIONS WILL RAPIDLY IMPROVE AS THE FRONT MOVES EAST OF THE TAF SITES WITH VFR CONDITIONS RETURNING TO ALL SITES BY 12/02Z. WINDS WILL BE LIGHT AND VARIABLE WINDS THROUGH 13Z THEN INCREASE STEADILY TO SOUTHERLY AT 15 KNOTS WITH GUSTS TO 25 KNOTS...FINALLY VEERING TO WESTERLY AT 10 KNOTS GUSTING TO 18 KNOTS BEHIND THE FRONT. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MONDAY NIGHT THROUGH TUESDAY MORNING IN SHOWERS ASSOCIATED WITH THE NEXT COLD FRONT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
111 AM EST SAT JAN 11 2014 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE NORTHEAST COAST WILL CIRCULATE MOIST AIR FROM THE ATLANTIC INTO THE FORECAST AREA AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. THE FRONT WILL MOVE THROUGH THE AREA SATURDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT SUNDAY AND MONDAY. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... MOISTURE HAS BECOME MORE SHALLOW BEHIND A MID- LEVEL SHORTWAVE THROUGH. EXPECT LIMITED SHOWER COVERAGE OVERNIGHT. THE HIGH LOW- LEVEL MOISTURE AND WEDGE/WARM FRONT IN THE AREA IS SUPPORTING FOG. OBSERVATION TRENDS AND THE HRRR SUPPORT DENSE FOG. WE HAVE ISSUED A DENSE FOG ADVISORY. && .SHORT TERM /7 AM THIS MORNING THROUGH MONDAY NIGHT/... ON SATURDAY A COLD FRONT APPROACHES FROM THE WEST AND MOVES ACROSS THE CWA SATURDAY AFTERNOON. RAIN CHANCES WILL INCREASE TO NEAR 100 PERCENT AHEAD OF THE FRONT FROM LATE SATURDAY MORNING THROUGH THE AFTERNOON. SEVERE WEATHER IS ALSO A CONCERN WITH THE WARM MOIST AIR MASS RESULTING IN LI/S UP TO -3 AND A STRONG LOW- LEVEL JET OF NEARLY 60 KTS. SPC HAS THE CWA IN A SLIGHT RISK FOR SEVERE. THE MAIN THREAT FOR SEVERE IS FROM DAMAGING WINDS IN THE CONVECTIVE LINE ASSOCIATED WITH THE FRONT. HOWEVER STRONG SHEAR MAY ALSO INCLUDE THE RISK FOR SOME ROTATION EMBEDDED IN THE LINE. DRYING WILL OCCUR BEHIND THE FRONT SATURDAY NIGHT. POPS WILL DECREASE RAPIDLY FROM WEST TO EAST SATURDAY EVENING. HIGH PRESSURE AND DRY WEATHER WITH TEMPERATURES ABOVE THE SEASONAL AVERAGE WILL BE ON TAP FOR SUNDAY AND MONDAY. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE MODELS DISPLAY MOISTURE ASSOCIATED WITH A COLD FRONT INTO EARLY TUESDAY MORNING. THE ECMWF SHOWS A MUCH STRONGER SYSTEM BRINGING LIKELY POPS. GFS WITH MUCH WEAKER SYSTEM PULLING TO THE NORTH TUESDAY. WILL CONTINUE CHANCE POPS. EXPECT A REINFORCING COLD FRONT WITH LIMITED MOISTURE WEDNESDAY. TIGHT PRESSURE GRADIENT EXPECTED WEDNESDAY RESULTING IN BREEZY CONDITIONS. ABOVE NORMAL TEMPERATURES SHOULD OCCUR TUESDAY...WITH NEAR OR SLIGHTLY BELOW NORMAL READINGS BEHIND THE FRONT BY THURSDAY. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... RESTRICTIONS DOMINATING THROUGH 12/00Z THEN CONDITIONS IMPROVING. SHOWERS HAVE DIMINISHED ACROSS THE TAF SITES...HOWEVER WITH CALM WINDS CIGS AND VSBYS HAVE LOWERED INTO THE LIFR RANGE. EXPECT CONDITIONS TO REMAIN LIFR THROUGH 13Z WHEN THE PRESSURE GRADIENT AHEAD OF THE COLD FRONT WILL INCREASE WINDS AND IMPROVE CIGS AND VSBYS TO IFR RANGE. COLD FRONT WILL MOVE INTO THE TAF SITES DURING THE MORNING ALONG WITH SHOWERS AND GUSTY WINDS. CONFIDENCE IN THUNDERSTORMS CONTINUES TO INCREASE...HOWEVER TIMING CONFIDENCE IS TOO LOW TO INCLUDE IN TAFS ATTM. BEST POTENTIAL FOR THUNDERSTORMS WILL BE 16Z THROUGH 22Z. CONDITIONS WILL RAPIDLY IMPROVE AS THE FRONT MOVES EAST OF THE TAF SITES WITH VFR CONDITIONS RETURNING TO ALL SITES BY 12/02Z. WINDS WILL BE LIGHT AND VARIABLE WINDS THROUGH 13Z THEN INCREASE STEADILY TO SOUTHERLY AT 15 KNOTS WITH GUSTS TO 25 KNOTS...FINALLY VEERING TO WESTERLY AT 10 KNOTS GUSTING TO 18 KNOTS BEHIND THE FRONT. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MONDAY NIGHT THROUGH TUESDAY MORNING IN SHOWERS ASSOCIATED WITH THE NEXT COLD FRONT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1220 AM EST SAT JAN 11 2014 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE NORTHEAST COAST WILL CIRCULATE MOIST AIR FROM THE ATLANTIC INTO THE FORECAST AREA AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. THE FRONT WILL MOVE THROUGH THE AREA SATURDAY. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT SUNDAY AND MONDAY. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... MOISTURE HAS BECOME MORE SHALLOW BEHIND A MID-LEVEL SHORTWAVE THROUGH. EXPECT LIMITED SHOWER COVERAGE OVERNIGHT. THE HIGH LOW- LEVEL MOISTURE AND WEDGE/WARM FRONT IN THE AREA IS SUPPORTING FOG. OBSERVATION TRENDS AND THE HRRR SUPPORT DENSE FOG. WE HAVE ISSUED A DENSE FOG ADVISORY. && .SHORT TERM /7 AM THIS MORNING THROUGH MONDAY NIGHT/... ON SATURDAY A COLD FRONT APPROACHES FROM THE WEST AND MOVES ACROSS THE CWA SATURDAY AFTERNOON. RAIN CHANCES WILL INCREASE TO NEAR 100 PERCENT AHEAD OF THE FRONT FROM LATE SATURDAY MORNING THROUGH THE AFTERNOON. SEVERE WEATHER IS ALSO A CONCERN WITH THE WARM MOIST AIR MASS RESULTING IN LI/S UP TO -3 AND A STRONG LOW- LEVEL JET OF NEARLY 60 KTS. SPC HAS THE CWA IN A SLIGHT RISK FOR SEVERE. THE MAIN THREAT FOR SEVERE IS FROM DAMAGING WINDS IN THE CONVECTIVE LINE ASSOCIATED WITH THE FRONT. HOWEVER STRONG SHEAR MAY ALSO INCLUDE THE RISK FOR SOME ROTATION EMBEDDED IN THE LINE. DRYING WILL OCCUR BEHIND THE FRONT SATURDAY NIGHT. POPS WILL DECREASE RAPIDLY FROM WEST TO EAST SATURDAY EVENING. HIGH PRESSURE AND DRY WEATHER WITH TEMPERATURES ABOVE THE SEASONAL AVERAGE WILL BE ON TAP FOR SUNDAY AND MONDAY. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE MODELS DISPLAY MOISTURE ASSOCIATED WITH A COLD FRONT INTO EARLY TUESDAY MORNING. THE ECMWF SHOWS A MUCH STRONGER SYSTEM BRINGING LIKELY POPS. GFS WITH MUCH WEAKER SYSTEM PULLING TO THE NORTH TUESDAY. WILL CONTINUE CHANCE POPS. EXPECT A REINFORCING COLD FRONT WITH LIMITED MOISTURE WEDNESDAY. TIGHT PRESSURE GRADIENT EXPECTED WEDNESDAY RESULTING IN BREEZY CONDITIONS. ABOVE NORMAL TEMPERATURES SHOULD OCCUR TUESDAY...WITH NEAR OR SLIGHTLY BELOW NORMAL READINGS BEHIND THE FRONT BY THURSDAY. && .AVIATION /05Z SATURDAY THROUGH WEDNESDAY/... HIGH CONFIDENCE IN RESTRICTIONS DOMINATING THE PERIOD. REGIONAL RADAR COMPOSITE SHOWS MOST OF THE MODERATE TO HEAVY RAIN HAS NOW SHIFTED NORTHEAST OF THE TAF SITES WITH SCATTERED SHOWERS AND DRIZZLE CONTINUING ACROSS THE AREA. EXPECT IFR/LIFR CONDITIONS TO CONTINUE OVERNIGHT AND INTO SATURDAY. CHANCES OF SHOWERS AND POSSIBLY THUNDERSTORMS WILL INCREASE SATURDAY AS A COLD FRONT APPROACHES. DID NOT INCLUDE MENTION OF THUNDER AT THIS TIME DUE TO LOW CONFIDENCE IN TIMING. WINDS WILL ROTATE FROM NORTHEASTERLY TO SOUTHERLY OVERNIGHT AND REMAIN LIGHT. WINDS WILL INCREASE ON SATURDAY AHEAD OF THE FRONTAL BOUNDARY AND BECOME MORE SOUTHWESTERLY BY LATE AFTERNOON AS THE COLD FRONT CROSSES THE AREA. HIGHER WIND GUSTS MAY MIX DOWN TO THE SURFACE PARTICULARLY IN THE CONVECTIVE LINE ASSOCIATED WITH THE FRONT. SHOWERS SHOULD SHIFT EAST OF THE AREA TOWARD THE END OF THE TAF PERIOD WITH RESTRICTIONS IMPROVING. EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MONDAY NIGHT THROUGH TUESDAY MORNING IN SHOWERS ASSOCIATED WITH THE NEXT COLD FRONT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
426 PM CST SAT JAN 11 2014 .DISCUSSION... 306 PM CST LOOKING AHEAD TO THE COMING WEEK...THE FIRST THING THAT BECOMES APPARENT IS HOW CHALLENGING THE TEMPERATURE FORECASTS MIGHT BE...WITH MULTIPLE POTENTIAL PERIODS OF NON DIURNAL TRENDS. THE BEST CHANCE OF MORE SNOW APPEARS TO BE MONDAY NIGHT INTO TUESDAY. SUNDAY SUNDAY AFTERNOON LOOKS PRETTY STRAIGHTFORWARD WITH PRONOUNCED WARM ADVECTION ON SOUTH TO SOUTHWEST WINDS DEVELOPING UNDER A 50 TO 60 KT JET AT 850 MB. LATEST VIS SATELLITE IMAGERY SUGGESTS DOWNSTATE ILLINOIS HAS LOST MUCH OF ITS SNOWPACK...WHICH WOULD FURTHER AID IN THE POTENTIAL WARMING OR AT LEAST NOT HINDER THE EFFECTS. FORECAST MAX TEMPERATURE GRIDS LEAN TOWARD THE WARMER GUIDANCE SOURCES...SO HOPEFULLY THIS IS NOT JUST A WISHCAST. SUNDAY NIGHT AND MONDAY A COLD FRONT ASSOCIATED WITH LOW PRESSURE MOVING ACROSS ONTARIO AND QUEBEC THEN PASSES THROUGH THE AREA EARLY MONDAY. TEMPERATURES ONLY GRADUALLY FALL SUNDAY NIGHT AHEAD OF THE FRONT...AND THEN REMAIN NEARLY FLAT IN POST FRONTAL FLOW DURING THE DAY MONDAY. HIGHS ON MONDAY MAY OCCUR AT MIDNIGHT SUNDAY NIGHT ESPECIALLY IN THE NORTH. FOR MOST OF THE REGION THIS LOOKS TO BE A DRY FRONTAL PASSAGE...AS THE BEST LIFT AND SATURATION IS FOCUSED NORTH OF THE AREA CLOSER TO THE LOW. MONDAY NIGHT AND TUESDAY DETERMINISTIC MODELS SHOW REASONABLE AGREEMENT ON THE POSITION OF A LONGWAVE UPPER TROUGH PASSING THROUGH THE GREAT LAKES LATE MONDAY INTO TUESDAY...BUT CONSIDERABLE DISAGREEMENT ON THE TIMING AND LOCATION OF A SURFACE LOW ASSOCIATED WITH A SHORTWAVE TRAVERSING THE SOUTHERN EXTENT OF THE UPPER TROUGH. THE GFS IS THE MOST PROGRESSIVE WITH THIS FEATURE...THE ECM/GEM ARE THE SLOWEST...AND THE NAM SOMEWHAT SPLITS THE DIFFERENCE. THE ACTUAL TRACK THAT DEVELOPS WILL DETERMINE BOTH TEMPERATURES AND SNOWFALL POSSIBILITIES TUESDAY...BUT UNFORTUNATELY IT STILL IS A BIT EARLY TO LEAN TOO HEAVILY ON ANY SOLUTION. REGARDLESS OF THE FINAL TRACK...THIS PERIOD APPEARS TO BRING THE BEST CHANCE LOCALLY FOR A QUICK SHOT OF ACCUMULATING SNOWFALL OVER THE NEXT WEEK. TUESDAY NIGHT AND WEDNESDAY THE SURFACE LOW AND ANY ASSOCIATED SNOW THAT MODELS CANNOT AGREE ON TUESDAY WILL EXIT THE AREA BY EARLY WEDNESDAY...USHERING IN ANOTHER PERIOD OF COLD NORTHWEST FLOW THAT DROPS OVERNIGHT LOWS INTO THE SINGLE DIGITS FOR SOME AREAS AND KEEPS A LID ON THE DAYTIME WARMING WEDNESDAY...LIMITING HIGHS TO THE TEENS TO AROUND 20. WEDNESDAY NIGHT AND THURSDAY WINDS QUICKLY TURN SOUTHWEST AGAIN WEDNESDAY NIGHT AND THURSDAY PRODUCING ANOTHER POTENTIAL MILD WARMUP TO ABOVE FREEZING TEMPERATURES THURSDAY. IN REALITY THIS MAY END UP BEING LESS OF A WARMUP IF THE FASTER MODEL SOLUTIONS ARE TO BE BELIEVED AND THE NEXT IN AN ENDLESS SERIES OF COLD FRONTS MOVES THROUGH THE AREA EARLIER IN THE DAY THURSDAY. THURSDAY NIGHT INTO SATURDAY REGARDLESS OF THE FRONTAL TIMING ON THURSDAY...TEMPERATURES FALL THURSDAY NIGHT AND CONTINUE TO FALL THROUGH THE FRIDAY MORNING PERIOD...THEN REMAIN FLAT OR ONLY GRADUALLY RISING DURING THE DAY FRIDAY. COLD NORTHWEST WINDS REMAIN OVER THE AREA INTO SATURDAY AND KEEP TEMPERATURES BELOW SEASONABLE NORMS. LENNING && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * MVFR CIGS CONTINUING INTO THE EARLY OVERNIGHT HOURS...MAY LOWER TOWARDS 010-015 THIS EVENING. * WEST WINDS WITH OCCASIONAL GUSTS AROUND 20 KT LATE THIS AFTERNOON BEFORE DIMINISHING THIS EVENING. SOUTH-SOUTHWEST WINDS INCREASE SUNDAY MORNING GUSTING 25-30 KT. MDB //DISCUSSION...UPDATED 22Z... ONE BAND OF CLOUD COVER HAS BEEN TRYING TO DEPART TO THE EAST TODAY BUT ANOTHER CONTINUES TO WORK SOUTHEAST INTO THE AREA. DO NOT EXPECT ANY CLEARING/SCATTERING AT THE TERMINALS THIS AFTERNOON AS THIS NEXT BAND CONTINUES TO MOVE IN. EXPECT MVFR TO CONTINUE AS A RESULT THOUGH THERE MAY BE SOME LOWERING FROM CURRENT BASES NEAR 2000 FT DOWN INTO THE 1000-1500 FT RANGE THIS EVENING BEFORE SCATTERING OCCURS LATER TONIGHT. MDB FROM 18Z... LOW PRESSURE SYSTEM NORTHEAST OF LAKE HURON BROUGHT A TRAILING FRONTAL BOUNDARY ACROSS NORTHERN IL/NORTHWEST IN AIRFIELDS EARLY THIS MORNING. BEHIND THIS BOUNDARY WINDS BECAME MORE WESTERLY...AND HAVE GUSTED AT TIMES TO 20-22KT. SKIES HAVE REMAINED POOR WITH CIGS ARND 1200-1500FT AGL. GUIDANCE HAS BACKED OFF ON CIGS IMPROVING MUCH BEYOND CURRENT HEIGHTS...HOWEVER BASED ON LATEST SATELLITE IMAGERY SOME THINNING IS TAKING PLACE ACROSS EASTERN IOWA/FAR WESTERN IL. ALTHOUGH THIS CLEARING DOES NOT LOOK LIKE IT WILL MAKE IT ALL OF THE WAY TO ORD/MDW. BASED ON THE LOWER CONFIDENCE IN CIGS LIFTING TO VFR OR ERODING ALL TOGETHER...HAVE HELD ONTO LOW END MVFR BKN DECK. FURTHER WEST AT RFD AND POSSIBLY DPA...SKIES MAY BRIEFLY BECOME SCT AFT 02Z THIS EVENING AND LINGER THRU MIDNIGHT BEFORE BECOMING BKN YET AGAIN. WITHIN THIS WINDOW OF SCT CIGS...SHALLOW GROUND FOG MAY DEVELOP AT RFD/DPA. WINDS WILL REMAIN LIGHT FROM THE WEST ARND 8-10KT...THEN ARND DAYBREAK SUN WINDS BEGIN TO TURN MORE SOUTHWESTERLY AND EVENTUALLY SOUTHERLY BY MIDDAY SUN. WITH A TIGHTENING GRADIENT EXPECTED SUN...AND THIN CLOUD COVER WITH THE EXCEPTION OF A CIRRUS DECK...WINDS WILL BECOME BREEZY AT 18 TO 22KT WITH GUSTS UP TO 30 KT IN THE AFTN HOURS. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 22Z... * HIGH CONFIDENCE IN MVFR CIGS INTO THE OVERNIGHT HOURS...WITH MEDIUM CONFIDENCE IN SOME LOWERING THIS EVENING. MEDIUM CONFIDENCE IN TIMING OF SCATTERING/CLEARING. * HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS. MDB //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...LLWS POSSIBLE EARLY...CHANCE OF IFR CIGS. MONDAY...SMALL CHANCE OF MVFR OR POSSIBLY IFR CIGS. TUESDAY...SNOW AND IFR ARE POSSIBLE. WEDNESDAY...VFR PROBABLE. THURSDAY...MVFR CIGS POSSIBLE. FRIDAY...VFR PROBABLE. IZZI && .MARINE... 223 PM CST LOW PRESSURE WILL CONTINUE TO LIFT ACROSS ONTARIO AND QUEBEC THROUGH THE OVERNIGHT HOURS WHILE A RIDGE WILL BUILD INTO THE WESTERN LAKES REGION. W/NW WINDS WILL PEAK AROUND 30 KT THIS EVENING...THEN SHOULD BACK TO THE SOUTH DIMINISH SOME OVERNIGHT. SOUTHWEST WINDS BEGIN TO QUICKLY PICK UP AGAIN DURING THE DAY SUNDAY AS ANOTHER LOW TRACKS EAST ACROSS THE CANADIAN PRAIRIES. GALES TO 40 KT ARE POSSIBLE SUNDAY AND SUNDAY NIGHT AND A GALE WATCH REMAINS IN EFFECT FOR THIS PERIOD. DECIDED NOT TO UPGRADE TO A WARNING YET BECAUSE OF MODERATE DIFFERENCES BETWEEN THE MODELS MAINLY CONCERNING THE AMOUNT OF STABILITY THAT WILL DEVELOP IN THE WARM ADVECTION OVER THE WATERS WHICH COULD INHIBIT WINDS. A COLD FRONT WILL SWEEP ACROSS LAKE MICHIGAN MONDAY WITH WINDS TURNING WESTERLY TO AROUND 30 KT. A CLIPPER SYSTEM IS FORECAST TO IMPACT THE REGION TUESDAY THOUGH THERE REMAINS CONSIDERABLE SPREAD IN THE MODELS REGARDING THE TRACK AND TIMING OF THE LOW. CONTINUE TO LEAN TOWARDS DEEPER/SLOWER SOLUTIONS SUCH AS THE GEM/ECWMF. YET ANOTHER SIGNIFICANT LOW IS EXPECTED TO DROP INTO THE NORTHERN LAKES REGION THURSDAY INTO FRIDAY. THIS DEEP LOW WILL LIKELY BRING STRONG GALES TO LAKE MICHIGAN...AND CANNOT RULE OUT STORM FORCE WINDS AT THIS TIME. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM SATURDAY. GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...11 AM SUNDAY TO 3 AM MONDAY. && $$ 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 315 PM CST Sat Jan 11 2014 .DISCUSSION... ISSUED 316 PM CST Sat Jan 11 2014 A progressive upper level pattern is expected for much of the upcoming week in the Midwest. The result will fairly quiet weather with only minor chances of light precipitation and fluctuating temperatures. SHORT TERM...Tonight through Monday Cooler temperatures are expected tonight with a light west wind. However, readings will still be above typical values for mid- January. Low level warm advection will kick in Sunday as low and mid level wind field back to more of southwesterly flow. In addition, the latest visible satellite and observations from early today indicate that there are only a few areas of widespread snow cover remaining west of the Illinois River and along the I-70 corridor. This will allow temperatures to climb well into the 45 to 50 degree range Sunday afternoon, which in turn will melt most of the remaining snow. Should see a return to mostly cloudy conditions this evening, especially in northern and central IL. However, as the main upper level trough over us now rapidly shifts to the east overnight, subsidence should result in decreasing clouds late tonight. Only a few clouds are expected Sunday, which will help warm things up. An upper level trough, now approaching the western U.S. coast will quickly move toward the Midwest by Monday. At the same time, an upper low in the Baja region will lift out with the advancing trough. This southern stream system may bring some light rain into parts of southeast IL, but overall the forecast area will remain dry on Monday but turn colder as a cold front moves through during the morning. LONG TERM...Tuesday through Saturday The best chance for precipitation in the longer term looks to be Tuesday as a fast moving Clipper system moves across northern Illinois early in the day. Moisture will be rather sparse, so light precipitation is expected during the day Tuesday. Low level temperature fields could be warm enough for rain or a rain/snow mix south of a Jacksonville-SPI-MTO-Marshall line Tuesday morning. However, increasing northwest winds and cold advection during the day Tuesday would be more conducive for light snow in nearly all of the forecast area by afternoon, along with falling temperatures. The exception may be areas south of I-70, so will keep the potential for a mix of rain/snow there all day. High pressure will settle in for Wednesday with clearing skies and a return to chilly temperatures. The longer range models are in generally good agreement by showing a building ridge in western U.S. with a developing northwest flow over the Midwest by Friday. This would result in a brief warm up for Thursday, followed by a return to colder than normal temperatures for the end of the week. There is some disagreement as to how far south any associated precpitation may develop for late in the week. The GFS indicates a clear cut lake effect snow situation, while the European model is a bit stronger and colder with its upper level pattern - resulting in light snow reaching central IL. Will keep the forecast dry for now and wait for more consistent model runs to see if there is enough low level moisture and forcing to mention late week light snow. Miller && .AVIATION... ISSUED 1150 AM CST Sat Jan 11 2014 1725z satellite imagery shows back edge of the cloud cover along a KPIA to KSPI line. Based on timing tools, clearing will reach KDEC and KBMI by 19z and KCMI by 20z. Once these clouds leave the TAF sites, the next issue will be monitoring low clouds currently sinking southeastward into central Iowa. Trajectory of this cloud cover brings it across the northern half of the KILX CWA late this afternoon and evening. HRRR has a very good handle on the clouds initially, but then tends to re-develop low clouds on the back side of the deck across Iowa tonight, resulting in a slow clearing trend overnight. NAM forecast soundings seem a bit more reasonable based on current satellite trends, so will lean toward this solution. As such, have brought MVFR ceilings back into KPIA after 22z, then further east to KBMI and KCMI after 00z. Clouds will then depart during the 06z to 08z time frame. Further south, think cloud area will only graze the southernmost terminals, so will keep skies mostly clear this evening at both KSPI and KDEC. Winds will initially be from the west with gusts to between 20 and 25kt this afternoon, then will diminish to less than 10kt overnight. As high pressure shifts east of the area, winds will back to southerly and gust to between 15 and 20kt by Sunday morning. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1211 PM CST SAT JAN 11 2014 .DISCUSSION... 334 AM CST SHORT TERM...TODAY THROUGH MONDAY IN THE NEAR TERM...PRIMARY CONCERN IS WITH EXTENT AND DURATION OF DENSE FOG AHEAD OF COLD FRONT TRAILING FROM LOW PRESSURE NEAR THE U.P. OF MICHIGAN. WILL MAKE A DECISION BEFORE SENDING OUT ZONES ON WHETHER TO ISSUE A DENSE FOG ADVISORY THRU THE EARLY MORNING...LIKELY FOR AREAS ALONG/EAST OF I-57...OR RIDE WITH AN SPS. COLD FROPA AND SHIFT TO WEST WINDS WILL RESULT IN QUICK IMPROVEMENT IN VSBY AS IS OCCURRING CURRENTLY IN NW IL. ANY LINGERING RAIN SHOWERS OVER EASTERN CWA WILL BE OFF TO THE EAST BY MID MORNING...IF NOT SOONER. REST OF TODAY-TONIGHT... A LOOK AT OBSERVATIONS AND FOG PRODUCT SATELLITE SHOWS EXTENSIVE OVC WELL BEHIND COLD FRONT BACK TO CENTRAL IA. HAVE SLOWED CLEARING TREND IN SKY GRIDS...SO MOST OF THE DAYLIGHT HOURS WILL LIKELY BE SPENT CLOUDY TODAY FOR MUCH OF THE AREA. CONTINUED MODEST COOL ADVECTION IN WAKE OF FRONT IS EXPECTED TO YIELD MORNING HIGHS...THOUGH THERE COULD BE SOME IMPROVEMENT IN THE AFTERNOON DESPITE CLOUD COVER. SKIES WILL CLEAR THIS EVENING AND TONIGHT...AND THOUGH THERE WILL BE WARM ADVECTION DEVELOPING...SOUTHWESTERLY FLOW COULD WEAKEN ENOUGH TO ALLOW FOR INVERSION AND DECOUPLING. HAVE TRENDED LOWS A BIT COLDER/MID TEENS/FOR AREAS THAT RETAIN A DEEP SNOW PACK WEST OF FOX VALLEY/RFD STILL AT 9 INCHES AS OF 06Z. SUNDAY-SUNDAY NIGHT... A STRONG LOW PRESSURE AREA WILL BE TRACKING ACROSS THE CANADIAN PRAIRIES TO WESTERN ONTARIO...THOUGH WEAKENING SOME WITH TIME. STRONG WARM ADVECTION ALOFT AND GUSTY SSW SURFACE FLOW WILL ENABLE A QUICK WARM UP. 925 MB TEMPS WARMING TO +4 TO +6C ACROSS THE AREA EXPECTED TO SUPPORT HIGHS IN THE LOW TO MID 40S EAST OF A LINE FROM UGN TO VYS...WITH U30S TO AROUND 40 TO THE WEST OF THAT LINE WHERE SNOW PACK WILL BE SLOWER TO MELT. IN ADDITION...GOOD PRESSURE FALLS ESPECIALLY DURING THE AFTERNOON WILL RESULT IN WINDY CONDITIONS...WITH GUSTS SOLIDLY IN THE 30-35 MPH RANGE AND POSSIBLY HIGHER IF THE STRONGER MOMENTUM FURTHER ALOFT CAN BE TAPPED INTO. A COLD FRONT TRAILING FROM THE LOW WILL SWING THROUGH THE AREA SUNDAY NIGHT...AND EXPECTING IT TO BE A DRY FROPA...AS GUIDANCE SHOWING ANY QPF SUCH AS THE NAM APPEARS TO BE STRUGGLING WITH LOW LEVEL MOISTURE PROFILES. MONDAY... GUIDANCE HAS TRENDED FARTHER SOUTHEAST AND QUICKER WITH SOUTHERN STREAM SYSTEM...SO SLIGHT POPS CURRENTLY IN GRIDS IN FAR SOUTHEAST ON MONDAY MORNING MAY BE ABLE TO BE REMOVED IF TRENDS CONTINUE. IF ANY PRECIP OCCURS AT THAT TIME...IT WOULD BE IN THE FORM OF RAIN. THERE WILL BE COLD ADVECTION BEHIND THE FRONT...THOUGH MODELS DIFFER ON STRENGTH AND TIMING DURING MONDAY. CURRENTLY ONLY HAVE A MINOR RISE IN TEMPS ON MONDAY FROM SUNDAY NIGHT LOWS...BUT IF FASTER GFS VERIFIES...TEMPS WILL BE MORE LIKELY TO FALL THROUGH THE DAY ON MONDAY. LONG TERM...MONDAY NIGHT THROUGH FRIDAY... THINGS DO GET A BIT MORE INTERESTING MONDAY NIGHT. OPERATIONAL MODELS HAVE COME INTO BETTER AGREEMENT ON A STRONG CLIPPER SYSTEM TRACKING TOWARD THE AREA OVERNIGHT INTO TUESDAY...THOUGH GFS WHICH HAS HAD THIS SYSTEM FOR A FEW RUNS NOW...IS MUCH FASTER WITH IT. THE INDIVIDUAL GFS ENSEMBLES ARE ALL FEATURING THIS SYSTEM AS WELL...THOUGH WITH DECENT SPREAD IN TRACK AND TIMING. DESPITE UPPER WAVE AND SURFACE LOW BEING FAIRLY STOUT AS CURRENTLY MODELED...THESE NORTHWEST FLOW SYSTEMS FROM THIS RANGE TYPICALLY SHOW LARGE RUN TO RUN VARIANCE UNTIL GUIDANCE BETTER SAMPLES ASSOCIATED FEATURES. FOR NOW HAVE FAVORED THE SLOWER ECMWF (WHICH FINALLY CAME INTO LINE WITH OTHER MODELS WITH THIS SYSTEM) AND GGEM...WHICH RESULTS IN CHANCE POPS INTO THE FAR NORTH AFTER MIDNIGHT. HAVE RAISED POPS TO CHANCE RANGE ACROSS THE AREA DURING THE DAY ON TUESDAY. THERMAL PROFILES INDICATE P-TYPE WOULD BE IN FORM OF SNOW...BUT TRACK OF LOW AND 850 MB LOW...WILL BE KEY AS TO WHETHER WE SEE A GLANCING BLOW OR EVEN DECENT ACCUMULATING SNOW FROM THIS SYSTEM. AFTER THIS POSSIBLE SYSTEM...WEDNESDAY LOOKS TO BE A COLD DAY WITH THERMAL TROUGH OVERHEAD. HOWEVER MEDIUM RANGE GUIDANCE THEN FAVORS A VERY DEEP SYSTEM TRACKING ALONG THE CANADIAN BORDER ON THURSDAY...WITH A QUICK WARM UP TO OR ABOVE FREEZING LIKELY IN THAT SET-UP. THE EASTERN TROUGH WILL DEEPEN IN THE WAKE OF THIS SYSTEM...WITH POTENTIAL FOR A COLD AIR MASS/THOUGH NOT THAT TERRIBLY COLD IN CONTEXT OF THIS WINTER SO FAR/TO CLOSE THE WORK WEEK WITH 850 MB TEMPS IN THE MINUS TEENS CELSIUS IF NOT A BIT COLDER. HIGHS MAY REMAIN IN THE TEENS FOR AT LEAST PARTS OF THE AREA ON FRIDAY. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * LOW END MVFR CIGS LINGERING THRU THIS AFTN...POSSIBLY A PERIOD OF CIGS THINNING TO A SCT DECK...THEN BACK TO BKN LATE TONIGHT. * WEST WINDS TO 16KT WITH GUSTS ARND 20-22KT THRU THIS AFTN. GUSTS DIMINISH THIS EVE...THEN RETURN AGAIN LATE SUN MORNING AND COULD BE GUSTING TO 28KT SUN MIDDAY/AFTN. BEACHLER //DISCUSSION...UPDATED 18Z... LOW PRESSURE SYSTEM NORTHEAST OF LAKE HURON BROUGHT A TRAILING FRONTAL BOUNDARY ACROSS NORTHERN IL/NORTHWEST IN AIRFIELDS EARLY THIS MORNING. BEHING THIS BOUNDARY WINDS BECAME MORE WESTERLY...AND HAVE GUSTED AT TIMES TO 20-22KT. SKIES HAVE REMAINED POOR WITH CIGS ARND 1200-1500FT AGL. GUIDANCE HAS BACKED OFF ON CIGS IMPROVING MUCH BEYOND CURRENT HEIGHTS...HOWEVER BASED ON LATEST SATELLITE IMAGERY SOME THINNING IS TAKING PLACE ACROSS EASTERN IOWA/FAR WESTERN IL. ALTHOUGH THIS CLEARING DOES NOT LOOK LIKE IT WILL MAKE IT ALL OF THE WAY TO ORD/MDW. BASED ON THE LOWER CONFIDENCE IN CIGS LIFTING TO VFR OR ERODING ALL TOGETHER...HAVE HELD ONTO LOW END MVFR BKN DECK. FURTHER WEST AT RFD AND POSSIBLY DPA...SKIES MAY BRIEFLY BECOME SCT AFT 02Z THIS EVENING AND LINGER THRU MIDNIGHT BEFORE BECOMING BKN YET AGAIN. WITHIN THIS WINDOW OF SCT CIGS...SHALLOW GROUND FOG MAY DEVELOP AT RFD/DPA. WINDS WILL REMAIN LIGHT FROM THE WEST ARND 8-10KT...THEN ARND DAYBREAK SUN WINDS BEGIN TO TURN MORE SOUTHWESTERLY AND EVENTUALLY SOUTHERLY BY MIDDAY SUN. WITH A TIGHTENING GRADIENT EXPECTED SUN...AND THIN CLOUD COVER WITH THE EXCEPTION OF A CIRRUS DECK...WINDS WILL BECOME BREEZY AT 18 TO 22KT WITH GUSTS UP TO 30 KT IN THE AFTN HOURS. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS. * MEDIUM CONFIDENCE IN CIGS FORECAST. * LOW CONFIDENCE IN CIGS CLEARING. * HIGH CONFIDENCE IN SHALLOW FOG REMAINING WEST OF ORD/MDW TONIGHT. BEACHLER //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...LLWS POSSIBLE EARLY...CHANCE OF IFR CIGS. MONDAY...SMALL CHANCE OF MVFR OR POSSIBLY IFR CIGS. TUESDAY...SNOW AND IFR ARE POSSIBLE. WEDNESDAY...VFR PROBABLE. THURSDAY...MVFR CIGS POSSIBLE. FRIDAY...VFR PROBABLE. IZZI && .MARINE... 155 AM CST APPEARS AS THOUGH WE WILL ENTER ANOTHER BUSY PERIOD ON LAKE MICHIGAN WITH SEVERAL BOUTS OF GALES EXPECTED OVER THE NEXT WEEK AND ONLY BRIEF TIME WINDOWS OF LIGHTER WINDS. A MODERATELY STRONG WEST WIND WILL DEVELOP TODAY IN THE WAKE OF LOW PRESSURE DEPARTING THE REGION WITH A BRIEF LULL IN THE WINDS LATE TONIGHT INTO EARLY SUNDAY MORNING AS THEY BACK TO SOUTHWEST. AN INTENSE AND FAST MOVING LOW WILL RACE EAST ACROSS CANADA SUNDAY RESULTING IN A PERIOD OF SOUTH GALES...PROBABLY HIGHER END GALES OVER NORTHERN PORTIONS OF THE LAKE SUNDAY AFTERNOON AND EVENING. WHILE WINDS SHOULD EASE BELOW GALE FORCE BY MONDAY MORNING THEY SHOULD REMAIN FAIRLY STRONG THROUGH THE DAY MONDAY. TRACK/TIMING DIFFERENCES EXIST REGARDING A FAIRLY STRONG CLIPPER RACING SOUTHEAST INTO THE MIDWEST TUESDAY WITH ANOTHER PERIOD OF STRONG NORTHERLY WINDS AND POSSIBLE GALES IN THE WAKE OF THAT SYSTEM LATE TUESDAY OR EARLY WEDNESDAY. YET ANOTHER PERIOD OF GALES LOOKS LIKE A GOOD BET BY THURSDAY. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM SATURDAY. GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...11 AM SUNDAY TO 3 AM MONDAY. && $$ 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 AM CST Sat Jan 11 2014 .DISCUSSION... ISSUED 1045 AM CST Sat Jan 11 2014 Primary forecast challenge today will be sky trends. 16z/10am satellite imagery shows widespread cloud cover across most of the KILX CWA: however, clearing is beginning to work its way into west-central Illinois. Based on timing tools, skies will partially clear as far east as the I-55 corridor by early afternoon, then further east to the Indiana border after 4 PM. The potential complication with the clearing trend is another deck of low clouds currently dropping southeastward into central Iowa. Timing tools bring this cloud area into the Illinois River Valley by early afternoon, then spread it eastward across the northern half of the CWA through the evening hours. NAM forecast soundings have a good handle on the clouds, although clouds appear to be moving a bit faster than the model projects. End result will be a cloudy morning giving way to partly to mostly sunny skies by early afternoon, followed by increasing clouds from the northwest once again by mid to late afternoon. Will send updated zones shortly. Barnes && .AVIATION... ISSUED 1150 AM CST Sat Jan 11 2014 1725z satellite imagery shows back edge of the cloud cover along a KPIA to KSPI line. Based on timing tools, clearing will reach KDEC and KBMI by 19z and KCMI by 20z. Once these clouds leave the TAF sites, the next issue will be monitoring low clouds currently sinking southeastward into central Iowa. Trajectory of this cloud cover brings it across the northern half of the KILX CWA late this afternoon and evening. HRRR has a very good handle on the clouds initially, but then tends to re-develop low clouds on the back side of the deck across Iowa tonight, resulting in a slow clearing trend overnight. NAM forecast soundings seem a bit more reasonable based on current satellite trends, so will lean toward this solution. As such, have brought MVFR ceilings back into KPIA after 22z, then further east to KBMI and KCMI after 00z. Clouds will then depart during the 06z to 08z time frame. Further south, think cloud area will only graze the southernmost terminals, so will keep skies mostly clear this evening at both KSPI and KDEC. Winds will initially be from the west with gusts to between 20 and 25kt this afternoon, then will diminish to less than 10kt overnight. As high pressure shifts east of the area, winds will back to southerly and gust to between 15 and 20kt by Sunday morning. Barnes && .PREV DISCUSSION... ISSUED 240 AM CST Sat Jan 11 2014 Area of dense fog has been rolling eastward across the state early this morning ahead of a cold front, which was just crossing the Illinois/Iowa border at 2 am. The back edge of the fog is about 50-75 miles east of the front, so am most concerned east of the Illinois River for the next few hours. The lingering rain was mainly along the Indiana border and should be out of the forecast area soon. Temperatures have remained quite mild overnight, with upper 30s and lower 40s in many areas except the far northwest. Main forecast concerns involve precipitation chances next week, with periodic clipper systems zipping southeast. Also have some concerns with the extent of cold air late next week, with discrepancies between the GFS and ECMWF models on how far south the cold air will surge. SHORT TERM...Today through Monday: Will drop the dense fog advisory west of the Illinois River. HRRR has been doing a reasonable job with the low visibilities, and the threat will be more across the east. Will expand the advisory to cover the remainder of the CWA east of I-57 for a few hours early this morning, and extend the time a bit to around 7 am. Much of the fog should be out of the area by that point, except perhaps around Champaign and Danville. Deep upper trough to quickly swing eastward today, followed by another broadening trough early next week. Southerly winds to 25-30 mph and decent sunshine should boost temperatures into the mid-upper 40s everywhere, with some lower 50s in the southwest and southeast corners of the CWA. Cooler conditions on Monday as a cold front passes with the trough. Surge of moisture pushing northeast from the lower Mississippi Valley ahead of the trough has trended a bit further east with the latest model runs, and associated rainfall may largely miss us. Have maintained some 30-40% PoP`s mainly in the morning across the eastern CWA, but would not be surprised to see those continue to lower with subsequent forecasts. LONG TERM...Tuesday through Friday: Active upper pattern on tap for the upcoming week, with concerns for light precipitation and surge of cold air. Regarding the precipitation, first clipper will be racing southeast Monday night. The GFS is much more progressive and keeps the precip to the north, while the ECMWF and GEM models favor a more southern track and somewhat higher chances of precip. Have raised PoP`s a bit from the initialization levels to favor these latter models, and will mention a chance of snow on Tuesday, with a mix in the afternoon in the central and south. Second and stronger system will track more across the northern Great Lakes region and have kept precip chances out of our area, but Thursday and Thursday night will be rather windy. Latest ECMWF continues its trend of plunging a lobe of cold air much further south than the GFS late in the week, as the former model digs the eastern U.S. trough much deeper. 850 mb temps of -18C on the ECMWF would favor some teens for highs by Friday, while the GFS`s trough is already well to our east. Have not gone as cold as the ECMWF, but will continue with highs below freezing in all areas on Friday. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
329 AM CST SAT JAN 11 2014 .DISCUSSION... 857 PM CST REGIONAL SATELLITE IMAGERY SHOWS A PRONOUNCED MID LEVEL DRY SLOT PUNCHING IN ACROSS EASTERN IOWA AND FAR NORTHWESTERN ILLINOIS THIS EVENING. THIS FEATURE SHOULD CONTINUE EASTWARD ACROSS NORTHERN ILLINOIS OVERNIGHT...AND THIS WILL MARK AN END TO THE MUCH OF THE RAIN AND A TRANSITION TO DRIZZLE AND FOG ACROSS MUCH OF THE AREA AFTER MIDNIGHT. I WILL CONTINUE THE CURRENT FREEZING RAIN HEADLINE AS IS FOR NOW...DUE TO ALL THE REPORTS OF ICING AND BAD TRAVEL CONDITIONS ON AREA ROADS AND SIDE WALKS. WITH TIME...TEMPERATURES AND DEW POINTS IN THE MID TO UPPER 30S SHOULD SLOWLY WARM THE GROUND ENOUGH TO LIMIT ICING OVERNIGHT...BUT BY THIS TIME MOST OF THE PRECIP SHOULD BE DONE ANYWAYS. THE OTHER CONCERN WE ARE WATCHING OVER THE NEXT FEW HOURS IS THAT OF DENSE FOG. SEVERAL SITES ACROSS EASTERN IOWA AND INTO NORTHWESTERN ILLINOIS ARE REPORTING VISIBILITIES DROPPING DOWN AROUND A QUARTER MILE IN FOG. IT APPEARS THE MAIN THREAT FOR DENSE FOG WILL FOLLOW CLOSELY WITH THE TRACK OF THE SURFACE LOW...WHICH IS EXPECTED TO PUSH RIGHT ACROSS NORTHWESTERN ILLINOIS AND SOUTHERN WISCONSIN TONIGHT. SOME OF THIS DENSER FOG COULD GET INTO MY WESTERN AREAS. HOWEVER...I AM A LITTLE RELUCTANT TO ISSUE A DENSE FOG ADVISORY FOR THESE AREAS AS IT APPEARS THE DENSER FOG MAY BE SHORT LIVED...ONLY LASTING A COUPLE HOURS...WITH CONDITIONS IMPROVING RAPIDLY WITH THE PASSAGE OF THE SURFACE LOW AND COLD FRONT. I WILL CONTINUE TO MONITOR THE TRENDS...AND I MAY JUST COVER WITH AN SPS UNLESS IT BECOMES CLEAR THAT THE FOG COULD LAST A BIT LONGER. KJB //PREV DISCUSSION... 624 PM CST WE DECIDED TO ISSUE A FREEZING RAIN ADVISORY THROUGH THIS EVENING. ALTHOUGH AIR TEMPERATURES CONTINUE TO WARM TO NEAR 40...THE COLD GROUND IS ALLOWING AREA ROADS TO BECOME ICY. WE RECEIVED NUMEROUS REPORTS OF ACCIDENTS AND EVEN CLOSED HIGHWAYS ACROSS NORTH CENTRAL ILLINOIS. THE ILLINOIS STATE POLICE IS URGING DRIVERS TO STAY HOME THIS EVENING ACROSS NORTH CENTRAL ILLINOIS. GIVEN HOW BAD CONDITIONS APPEAR TO BE...WE HAVE OPTED TO GO WITH A FREEZING RAIN ADVISORY IN SPITE OF CONTINUED WARMING. WITH TIME THE ROAD TEMPS SHOULD WARM AND END THE THREAT FOR ICING. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 09Z... * IFR OR LOWER CIGS AND OCCASIONALLY VSBY UNTIL SUNRISE * VSBY RETURNS TO VFR AFTER SUNRISE SHORTLY AFTER WIND SHIFT TO WEST * IFR CIGS LIKELY TO PERSIST THROUGH MID MORNING WITH POSSIBLE IMPROVEMENT TO MVFR THIS AFTERNOON IZZI //DISCUSSION...UPDATED 09Z... HIGHLY VARIABLE VSBY IN THE WARM SECTOR AHEAD OF THE COLD FRONT WITH SOME LOCATIONS DOWN TO 1/4SM AND OTHERS STILL VFR...INCLUDING ORD/MDW. STILL FEEL THERE IS A GOOD SHOT AT ORD/MDW AT LEAST TEMPORARILY SEEING RATHER DENSE FOG DEVELOP FOR A TIME PRIOR TO WIND SHIFT TO THE WEST JUST BEFORE SUNRISE. REST OF TRENDS FROM PREVIOUS TAF LOOK GOOD. IZZI UPDATED 06Z... AREAS OF RAIN WILL CONTINUE TO AFFECT THE CHGO METRO TERMINALS THRU EARLY PART OF THE OVERNIGHT HOURS. IFR/LIFR CIGS WILL PERSIST IN THE MOIST SOUTHERLY WINDS TONIGHT IN ADVANCE OF APPROACHING COLD FRONT WITH AREAS OF IFR VSBY EXPECTED THROUGH REST OF THE OVERNIGHT HOURS. COLD FRONT SHOULD MOVE THROUGH RFD AROUND 09Z AND THROUGH CHGO METRO AROUND 11Z WITH WIND SHIFT TO WEST AND A SLOW FILTERING IN OF SLIGHTLY DRIER CONDITIONS RESULTING IN IMPROVING VSBY EARLY SATURDAY MORNING. STRATUS (MOSTLY IFR) EXTENDS BACK ACROSS ALL OF IOWA AND IS UNLIKELY TO MIX OUT SATURDAY...SO WOULD ANTICIPATE LOW CIGS TO HANG AROUND INTO SATURDAY AFTERNOON AND POSSIBLY INTO EVENING. SOME IMPROVEMENT TO LOW END MVFR IS POSSIBLE SATURDAY AFTERNOON. IZZI //ORD AND MDW CONFIDENCE...UPDATED 09Z... * HIGH CONFIDENCE IN IFR CIGS THROUGH AT LEAST MID MORNING * LOW-MEDIUM CONFIDENCE IN IMPROVEMENT TO MVFR TODAY * NO CONFIDENCE IN CIG FORECAST THIS EVENING * LOW CONFIDENCE THROUGH SUNRISE...HIGH CONFIDENCE IN VSBY REST OF TODAY * HIGH CONFIDENCE IN WIND FORECAST IZZI //OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z... SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY EVENING. VFR PROBABLE. MONDAY...VFR. TUESDAY...CHANCE OF SNOW/IFR. WEDNESDAY AND THURSDAY...VFR PROBABLE. MDB && .MARINE... 155 AM CST APPEARS AS THOUGH WE WILL ENTER ANOTHER BUSY PERIOD ON LAKE MICHIGAN WITH SEVERAL BOUTS OF GALES EXPECTED OVER THE NEXT WEEK AND ONLY BRIEF TIME WINDOWS OF LIGHTER WINDS. A MODERATELY STRONG WEST WIND WILL DEVELOP TODAY IN THE WAKE OF LOW PRESSURE DEPARTING THE REGION WITH A BRIEF LULL IN THE WINDS LATE TONIGHT INTO EARLY SUNDAY MORNING AS THEY BACK TO SOUTHWEST. AN INTENSE AND FAST MOVING LOW WILL RACE EAST ACROSS CANADA SUNDAY RESULTING IN A PERIOD OF SOUTH GALES...PROBABLY HIGHER END GALES OVER NORTHERN PORTIONS OF THE LAKE SUNDAY AFTERNOON AND EVENING. WHILE WINDS SHOULD EASE BELOW GALE FORCE BY MONDAY MORNING THEY SHOULD REMAIN FAIRLY STRONG THROUGH THE DAY MONDAY. TRACK/TIMING DIFFERENCES EXIST REGARDING A FAIRLY STRONG CLIPPER RACING SOUTHEAST INTO THE MIDWEST TUESDAY WITH ANOTHER PERIOD OF STRONG NORTHERLY WINDS AND POSSIBLE GALES IN THE WAKE OF THAT SYSTEM LATE TUESDAY OR EARLY WEDNESDAY. YET ANOTHER PERIOD OF GALES LOOKS LIKE A GOOD BET BY THURSDAY. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...GALE WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...11 AM SUNDAY TO 3 AM MONDAY. && $$ 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 242 AM CST Sat Jan 11 2014 .DISCUSSION... ISSUED 240 AM CST Sat Jan 11 2014 Area of dense fog has been rolling eastward across the state early this morning ahead of a cold front, which was just crossing the Illinois/Iowa border at 2 am. The back edge of the fog is about 50-75 miles east of the front, so am most concerned east of the Illinois River for the next few hours. The lingering rain was mainly along the Indiana border and should be out of the forecast area soon. Temperatures have remained quite mild overnight, with upper 30s and lower 40s in many areas except the far northwest. Main forecast concerns involve precipitation chances next week, with periodic clipper systems zipping southeast. Also have some concerns with the extent of cold air late next week, with discrepancies between the GFS and ECMWF models on how far south the cold air will surge. SHORT TERM...Today through Monday: Will drop the dense fog advisory west of the Illinois River. HRRR has been doing a reasonable job with the low visibilities, and the threat will be more across the east. Will expand the advisory to cover the remainder of the CWA east of I-57 for a few hours early this morning, and extend the time a bit to around 7 am. Much of the fog should be out of the area by that point, except perhaps around Champaign and Danville. Deep upper trough to quickly swing eastward today, followed by another broadening trough early next week. Southerly winds to 25-30 mph and decent sunshine should boost temperatures into the mid-upper 40s everywhere, with some lower 50s in the southwest and southeast corners of the CWA. Cooler conditions on Monday as a cold front passes with the trough. Surge of moisture pushing northeast from the lower Mississippi Valley ahead of the trough has trended a bit further east with the latest model runs, and associated rainfall may largely miss us. Have maintained some 30-40% PoP`s mainly in the morning across the eastern CWA, but would not be surprised to see those continue to lower with subsequent forecasts. LONG TERM...Tuesday through Friday: Active upper pattern on tap for the upcoming week, with concerns for light precipitation and surge of cold air. Regarding the precipitation, first clipper will be racing southeast Monday night. The GFS is much more progressive and keeps the precip to the north, while the ECMWF and GEM models favor a more southern track and somewhat higher chances of precip. Have raised PoP`s a bit from the initialization levels to favor these latter models, and will mention a chance of snow on Tuesday, with a mix in the afternoon in the central and south. Second and stronger system will track more across the northern Great Lakes region and have kept precip chances out of our area, but Thursday and Thursday night will be rather windy. Latest ECMWF continues its trend of plunging a lobe of cold air much further south than the GFS late in the week, as the former model digs the eastern U.S. trough much deeper. 850 mb temps of -18C on the ECMWF would favor some teens for highs by Friday, while the GFS`s trough is already well to our east. Have not gone as cold as the ECMWF, but will continue with highs below freezing in all areas on Friday. Geelhart && .AVIATION... ISSUED 1147 PM CST Fri Jan 10 2014 The cold front is just arriving in far western IL as of 05z, and will progress eastward across the terminal sites over the next 5-6 hours. Dense fog has begun to expand eastward with BMI and CMI down to 1/4SM FG. HRRR and RAP hi-res models still show widespread coverage of dense fog across a majority of central IL overnight, gradually clearing from the west late, with PIA vis improving to vfr after 11z. Have gone more pessimistic with vis across the board through sunrise, with the VLIFR mainly across the north. SPI and DEC have dodged the dense fog so far, but can not rule out a brief period of FG the rest of the night. Dense fog may linger at CMI to 13z, then clear out to VFR quickly. Clouds will remain in the IFR/LIFR range through much of the morning. Some VLIFR may continue at BMI until after sunrise as well. Clouds should improve to MVFR Sat afternoon, with a clearing line expected to push across the area by Sat evening. Winds will shift from S-SW to W with the cold FROPA, with winds shifting at PIA around 07-08z, and at CMI toward 12z. Wind speeds should remain steady in the 09-13kt range overnight, with gusts to 22-24kt returning Sat morning as mixing deepens. Shimon && .ILX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY until 7 AM CST this morning for ILZ031-037-038-045-046-055>057-062-063-066>073. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
155 AM CST SAT JAN 11 2014 .DISCUSSION... 857 PM CST REGIONAL SATELLITE IMAGERY SHOWS A PRONOUNCED MID LEVEL DRY SLOT PUNCHING IN ACROSS EASTERN IOWA AND FAR NORTHWESTERN ILLINOIS THIS EVENING. THIS FEATURE SHOULD CONTINUE EASTWARD ACROSS NORTHERN ILLINOIS OVERNIGHT...AND THIS WILL MARK AN END TO THE MUCH OF THE RAIN AND A TRANSITION TO DRIZZLE AND FOG ACROSS MUCH OF THE AREA AFTER MIDNIGHT. I WILL CONTINUE THE CURRENT FREEZING RAIN HEADLINE AS IS FOR NOW...DUE TO ALL THE REPORTS OF ICING AND BAD TRAVEL CONDITIONS ON AREA ROADS AND SIDE WALKS. WITH TIME...TEMPERATURES AND DEW POINTS IN THE MID TO UPPER 30S SHOULD SLOWLY WARM THE GROUND ENOUGH TO LIMIT ICING OVERNIGHT...BUT BY THIS TIME MOST OF THE PRECIP SHOULD BE DONE ANYWAYS. THE OTHER CONCERN WE ARE WATCHING OVER THE NEXT FEW HOURS IS THAT OF DENSE FOG. SEVERAL SITES ACROSS EASTERN IOWA AND INTO NORTHWESTERN ILLINOIS ARE REPORTING VISIBILITIES DROPPING DOWN AROUND A QUARTER MILE IN FOG. IT APPEARS THE MAIN THREAT FOR DENSE FOG WILL FOLLOW CLOSELY WITH THE TRACK OF THE SURFACE LOW...WHICH IS EXPECTED TO PUSH RIGHT ACROSS NORTHWESTERN ILLINOIS AND SOUTHERN WISCONSIN TONIGHT. SOME OF THIS DENSER FOG COULD GET INTO MY WESTERN AREAS. HOWEVER...I AM A LITTLE RELUCTANT TO ISSUE A DENSE FOG ADVISORY FOR THESE AREAS AS IT APPEARS THE DENSER FOG MAY BE SHORT LIVED...ONLY LASTING A COUPLE HOURS...WITH CONDITIONS IMPROVING RAPIDLY WITH THE PASSAGE OF THE SURFACE LOW AND COLD FRONT. I WILL CONTINUE TO MONITOR THE TRENDS...AND I MAY JUST COVER WITH AN SPS UNLESS IT BECOMES CLEAR THAT THE FOG COULD LAST A BIT LONGER. KJB //PREV DISCUSSION... 624 PM CST WE DECIDED TO ISSUE A FREEZING RAIN ADVISORY THROUGH THIS EVENING. ALTHOUGH AIR TEMPERATURES CONTINUE TO WARM TO NEAR 40...THE COLD GROUND IS ALLOWING AREA ROADS TO BECOME ICY. WE RECEIVED NUMEROUS REPORTS OF ACCIDENTS AND EVEN CLOSED HIGHWAYS ACROSS NORTH CENTRAL ILLINOIS. THE ILLINOIS STATE POLICE IS URGING DRIVERS TO STAY HOME THIS EVENING ACROSS NORTH CENTRAL ILLINOIS. GIVEN HOW BAD CONDITIONS APPEAR TO BE...WE HAVE OPTED TO GO WITH A FREEZING RAIN ADVISORY IN SPITE OF CONTINUED WARMING. WITH TIME THE ROAD TEMPS SHOULD WARM AND END THE THREAT FOR ICING. KJB && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * IFR OR LOWER CIGS AND OCCASIONALLY VSBY OVERNIGHT * VSBY RETURNS TO VFR AFTER SUNRISE SHORTLY AFTER WIND SHIFT TO WEST * IFR CIGS LIKELY TO PERSIST THROUGH LATE MORNING WITH POSSIBLE IMPROVEMENT TO MVFR SATURDAY AFTERNOON IZZI //DISCUSSION...UPDATED 06Z... AREAS OF RAIN WILL CONTINUE TO AFFECT THE CHGO METRO TERMINALS THRU EARLY PART OF THE OVERNIGHT HOURS. IFR/LIFR CIGS WILL PERSIST IN THE MOIST SOUTHERLY WINDS TONIGHT IN ADVANCE OF APPROACHING COLD FRONT WITH AREAS OF IFR VSBY EXPECTED THROUGH REST OF THE OVERNIGHT HOURS. COLD FRONT SHOULD MOVE THROUGH RFD AROUND 09Z AND THROUGH CHGO METRO AROUND 11Z WITH WIND SHIFT TO WEST AND A SLOW FILTERING IN OF SLIGHTLY DRIER CONDITIONS RESULTING IN IMPROVING VSBY EARLY SATURDAY MORNING. STRATUS (MOSTLY IFR) EXTENDS BACK ACROSS ALL OF IOWA AND IS UNLIKELY TO MIX OUT SATURDAY...SO WOULD ANTICIPATE LOW CIGS TO HANG AROUND INTO SATURDAY AFTERNOON AND POSSIBLY INTO EVENING. SOME IMPROVEMENT TO LOW END MVFR IS POSSIBLE SATURDAY AFTERNOON. IZZI //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN IFR CIGS THROUGH AT LEAST MID MORNING SATURDAY * LOW CONFIDENCE IN IMPROVEMENT TO MVFR SATURDAY * NO CONFIDENCE IN CIGS SATURDAY EVENING * LOW CONFIDENCE IN VSBY TRENDS REST OF THE OVERNIGHT...HIGH CONFIDENCE IN VSBY SATURDAY * HIGH CONFIDENCE IN WIND FORECAST IZZI //OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z... SUNDAY...STRONG SOUTH WINDS...LLWS POSSIBLE AFTERNOON/EARLY EVENING. VFR PROBABLE. MONDAY...VFR. TUESDAY...CHANCE OF SNOW/IFR. WEDNESDAY AND THURSDAY...VFR PROBABLE. MDB && .MARINE... 155 AM CST APPEARS AS THOUGH WE WILL ENTER ANOTHER BUSY PERIOD ON LAKE MICHIGAN WITH SEVERAL BOUTS OF GALES EXPECTED OVER THE NEXT WEEK AND ONLY BRIEF TIME WINDOWS OF LIGHTER WINDS. A MODERATELY STRONG WEST WIND WILL DEVELOP TODAY IN THE WAKE OF LOW PRESSURE DEPARTING THE REGION WITH A BRIEF LULL IN THE WINDS LATE TONIGHT INTO EARLY SUNDAY MORNING AS THEY BACK TO SOUTHWEST. AN INTENSE AND FAST MOVING LOW WILL RACE EAST ACROSS CANADA SUNDAY RESULTING IN A PERIOD OF SOUTH GALES...PROBABLY HIGHER END GALES OVER NORTHERN PORTIONS OF THE LAKE SUNDAY AFTERNOON AND EVENING. WHILE WINDS SHOULD EASE BELOW GALE FORCE BY MONDAY MORNING THEY SHOULD REMAIN FAIRLY STRONG THROUGH THE DAY MONDAY. TRACK/TIMING DIFFERENCES EXIST REGARDING A FAIRLY STRONG CLIPPER RACING SOUTHEAST INTO THE MIDWEST TUESDAY WITH ANOTHER PERIOD OF STRONG NORTHERLY WINDS AND POSSIBLE GALES IN THE WAKE OF THAT SYSTEM LATE TUESDAY OR EARLY WEDNESDAY. YET ANOTHER PERIOD OF GALES LOOKS LIKE A GOOD BET BY THURSDAY. IZZI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion National Weather Service Lincoln IL 1147 PM CST Fri Jan 10 2014 .DISCUSSION... ISSUED 900 PM CST Fri Jan 10 2014 Dense fog potential will increase as the cold front progresses across Illinois. We already issued a dense fog advisory for areas NW of the IL river, but the latest runs of the RAP and HRRR both show dense fog developing after midnight across nearly all of the remainder of the KILX CWA. Forecast soundings and current dewpoint depressions support that scenario, so may need to expand the advisory eastward by late evening. Upstream obs along the southern portion of the cold front are not as supportive of dense fog farther southeast, but we have had more snow melt from a deeper snow pack in our areas. Steady rainfall has generally become confined to areas southeast of I-70. A secondary batch of rain has redeveloped from STL to Jacksonville and is progressing to the ENE into our area. It should mainly affect areas along and southeast of I-55 over the next 4-6 hours. Colder air arriving behind the cold front will have the potential to change any lingering sprinkles or light rain west of I-55 into snow. However, subsidence should prevail by that time and precip should be minimal after the cold air arrives. Low temperatures are expected to dip below freezing NW of the IL river, with around freezing east to the I-55 corridor. That could help create some slippery conditions on untreated and secondary roads. Updates to the forecast grids this evening mainly covered the addition of fog and dense fog, as well as minor low temp adjustments. We also added slight chance of rain or snow lingering in the NE early Sat morning. The remainder of the forecast looks on track. Updated info will be available shortly. Shimon && .AVIATION... ISSUED 1147 PM CST Fri Jan 10 2014 The cold front is just arriving in far western IL as of 05z, and will progress eastward across the terminal sites over the next 5-6 hours. Dense fog has begun to expand eastward with BMI and CMI down to 1/4SM FG. HRRR and RAP hi-res models still show widespread coverage of dense fog across a majority of central IL overnight, gradually clearing from the west late, with PIA vis improving to vfr after 11z. Have gone more pessimistic with vis across the board through sunrise, with the VLIFR mainly across the north. SPI and DEC have dodged the dense fog so far, but can not rule out a brief period of FG the rest of the night. Dense fog may linger at CMI to 13z, then clear out to VFR quickly. Clouds will remain in the IFR/LIFR range through much of the morning. Some VLIFR may continue at BMI until after sunrise as well. Clouds should improve to MVFR Sat afternoon, with a clearing line expected to push across the area by Sat evening. Winds will shift from S-SW to W with the cold fropa, with winds shifting at PIA around 07-08z, and at CMI toward 12z. Wind speeds should remain steady in the 09-13kt range overnight, with gusts to 22-24kt returning Sat morning as mixing deepens. Shimon && .PREV DISCUSSION... ISSUED 253 PM CST Fri Jan 10 2014 Main issues for this forecast package include the rain tonight and then more chances for end of the weekend and beginning of next week. Models look in pretty good agreement through about 66hrs but then differ with intensity of next system and the resulting precip. Extended models do begin to look better once we get to the end of next week. So, confidence in forecast in the near term is good, but wanes with the next system(s) for the end of the weekend and the beginning of next week. So, will take a blend for now. SHORT TERM...Tonight through Monday Rain will continue to move across the area tonight and should begin to wane after midnight, and then be east and northeast of the area by morning. By then, the low pressure area associated with the pcpn will have moved into the Grt Lks region and the 500mb trough will be pushing through the region. So, beyond tonight, dry weather is expected for tomorrow through Sunday. After some ridging, another weak front will move into the area late Sunday night. The return of moisture ahead of this system looks weak and doesn`t seem to arrive until the frontal system is about halfway through the area. So will have chance of pcpn for Monday in the east and southeast only. Will also have a slight chc of pcpn for Sun night, but this will not show up in the worded forecast. Pcpn type should also be just rain as temps should be warm enough through the atmosphere to support all liquid and nothing frozen, and surface temps will be above freezing. Temps will continue to warm as area sits in a somewhat zonal pattern for the weekend. Guidance numbers look ok, but went a little warmer in the southeast for tonight. LONG TERM...Monday night through Friday The beginning of the extended is where the models really look different. The GFS brings another wave down across the area for Monday night through Tue, while the ECMWF has stronger southern stream energy that holds some pcpn back for Monday night and into Tuesday. Because of the differences, not confident enough to put chc pops in the forecast at this time. So will just have slight chc pops for the time period. Both models show a second wave/trough coming into the area from the northwest, so little bit cooler weather will move into the region. This will cause the pcpn type to be more of snow or rain/snow mix in the south part of the cwa. However, since this will be slight chc, the pops will not be seen in the worded forecast. But cloudy skies will be mentioned. Remainder of the extended period, and next week, will be dry. GFS brings additional chances of pcpn through the area, but ECMWF does not. For now, going with a dry forecast seems best. Temps will slightly warmer for Tue, but then become cooler again for Wed and again on Friday. MEX numbers seem to have a good handle on this currently. Auten && .ILX WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY until 6 AM CST Saturday FOR ILZ027>030-036- 040. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 PM CST FRI JAN 10 2014 .UPDATE... ISSUED AT 749 PM CST FRI JAN 10 2014 QUITE A FEW SITES NOW 1/2 TO 1/4 MILE ON VISIBILITIES AND SHOULD CONTINUE TO SEE VERY LOW VISIBILITIES BECOME WIDESPREAD WITH ABUNDANT MOISTURE AND DIMINISHING WINDS AHEAD OF PASSING SURFACE LOW. AS RESULT... HAVE ISSUED A DENSE FOG ADVISORY FOR THE ENTIRE CWA FOR THE REST OF TONIGHT. LATE TONIGHT... SAY AROUND 09Z OR SO WE MAY START TO SEE SOME IMPROVEMENT ON VISIBILITIES AS A FRONTAL BOUNDARY MOVES THROUGH THE REGION. THE POOR VISIBILITIES IN DENSE FOG COUPLED WITH ICY ROADWAYS ESPECIALLY NEAR/NORTH OF I-80 MAKING IT ONE OF THOSE NIGHTS BEST SUITED FOR NOT TRAVELING UNLESS NECESSARY. UPDATE ISSUED AT 444 PM CST FRI JAN 10 2014 EXPANDED ADVISORY TO INCLUDE JACKSON COUNTY IN IOWA AND JO DAVIESS AND STEPHENSON COUNTIES IN FAR NORTHERN ILLINOIS. REPORTS OF SEVERAL ROADS COMPLETELY COVERED IN JACKSON COUNTY... IA38...IA136 IA64. PAVEMENT TEMPS HOVERING AROUND FREEZING IN THESE AREAS ALLOWING FOR THE ICY CONDITIONS TO DEVELOP. COULD ACTUALLY SEE SOME IMPROVEMENT FOR A TIME THIS EVENING AS TEMPS CONTINUE TO SLOWLY CLIMB AHEAD OF AN APPROACHING SURFACE LOW. HOWEVER....ONCE THIS PASSES AND WINDS SHIFT TO WEST WILL SEE TEMPS DROP LATE THIS EVE AND OVERNIGHT AND MAY SEE MORE ICING WHETHER THROUGH REFREEZE OR POSSIBLY SOME LIGHT FREEZING DRIZZLE/FREEZING RAIN. UPDATE ISSUED AT 336 PM CST FRI JAN 10 2014 CALLS ARE NOW COMING IN REPORTING SLICK ROADS. THUS WILL HOIST A FREEZING RAIN ADVISORY FOR LATE AFTERNOON AND EVENING. TEMPORAL AND AREAL COVERAGE OF THE ADVISORY MAY NEED TO CHANGED THIS EVENING. && .SYNOPSIS... ISSUED AT 248 PM CST FRI JAN 10 2014 12Z UA ANALYSIS HAS A LLJ RUNNING FROM TEXAS INTO WESTERN MISSOURI. MOISTURE ASSOCIATED WITH THIS JET WAS IMPINGING UPON AN 850 MB WARM FRONT RUNNING FROM KANSAS INTO SOUTHERN ILLINOIS. RADAR TRENDS THROUGH MID AFTERNOON HAD A LARGE AREA OF RAIN FROM MISSOURI INTO ILLINOIS WITH LIGHTER RAIN/DRIZZLE MIXED WITH SOME FREEZING RAIN/DRIZZLE ACROSS IOWA. 18Z SFC ANALYSIS HAS A WEAK LOW NEAR KMHK WITH A WARM FRONT EAST ALONG THE MISSOURI RIVER. THE COLD FRONT RAN FROM THE LOW INTO SOUTHWEST OKLAHOMA. DEW POINTS WERE IN THE 20S AND 30S ACROSS THE UPPER MIDWEST AND GREAT LAKES WITH 40S AND HIGHER FROM THE OHIO VALLEY AND SOUTHERN PLAINS. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 248 PM CST FRI JAN 10 2014 BASED ON TRENDS FROM PRESSURE FALLS AND THE RAP MODEL...THE LOW SHOULD PASS OVER THE FAR NORTHWEST AREA BETWEEN KALO AND KCID THIS EVENING. WINDS WILL DECREASE AS THE LOW APPROACHES AND THE FOG IS EXPECTED TO BECOME MORE WIDESPREAD. RIGHT NOW NO ADVISORY FOR DENSE FOG IS PLANNED. HOWEVER...I WOULD NOT BE SURPRISED IF ONE IS NEEDED AT SOME POINT DURING THE EVENING. TEMPERATURES HAVE NOT BUDGED MUCH IN THE HIGHWAY 20 CORRIDOR FROM KDBQ ON WEST. THUS THIS AREA IS RIGHT ON THE CUSP OF SEEING FREEZING RAIN LATE THIS AFTERNOON AND EVENING AS LIFT CONTINUES TO INCREASE. HOWEVER...THE TRACK OF THE LOW SHOULD ALLOW TEMPERATURES TO RISE ABOUT ANOTHER DEGREE. FREEZING RAIN IS EXPECTED TO BE LOCALLY SPOTTY OVER THE FOUR NORTHWEST COUNTIES AND POSSIBLY WESTERN DUBUQUE COUNTY THROUGH MID EVENING. ONCE THE LOW PASSES...COLD AIR WILL SLOWLY BEGIN TO MOVE INTO THE AREA ALLOWING THE RAIN TO MIX WITH AND CHANGE TO SNOW FROM WEST TO EAST OVERNIGHT. DURING THE CHANGE OVER...A BRIEF PERIOD OF FREEZING RAIN WILL BE POSSIBLE. SNOW AMOUNTS WILL RANGE FROM A TRACE TO UNDER AN INCH. ON SATURDAY...LINGERING LIGHT SNOW WILL BE SEE OVER ROUGHLY THE NORTHEAST/EAST HALF OF THE AREA DURING THE MORNING. OTHERWISE DRY CONDITIONS ARE EXPECTED DURING THE DAY. SNOW AMOUNTS SATURDAY MORNING WILL BE A DUSTING AT BEST. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 248 PM CST FRI JAN 10 2014 NEARLY ZONAL UPPER AIR FLOW WILL BE OVER THE AREA THE REST OF THE WEEKEND THEN THE PATTERN CHANGES TO A RIDGE DOMINATED WESTERN U.S. AND A MEAN TROF SETTING UP OVER THE EAST. MILD CONDITIONS ARE ANTICIPATED FOR THE REGION SUNDAY AS UPPER RIDGING BUILDS OVER THE AREA SATURDAY NIGHT INTO SUNDAY. IN THE LOW LEVELS A SURFACE RIDGE WILL MOVE THROUGH THE REGION SATURDAY EVENING FOLLOWED BY STRONG LOW LEVEL WAA AHEAD OF A TROF DIGGING INTO THE SOUTHWEST U.S. AND A COLD FRONT OVER THE PLAINS. A LOW LEVEL THERMAL RIDGE CROSSES THE MID MISSISSIPPI VALLEY SUNDAY WITH H8 TEMPS PEAKING IN THE +8 TO +10C RANGE DURING THE AFTERNOON. GOOD MIXING IS ALSO SUGGESTED WITH A TIGHT SLP GRADIENT AHEAD OF THE COLD FRONT. EVEN WITH THE SNOW COVER...WE SHOULD SEE HIGHS TOPPING OUT IN THE MID 30S TO MID 40S. MODELS MOVE THE FRONT THROUGH THE REGION WITH OUT ANY PRECIPITATION SUNDAY NIGHT. THIS LOOKS REASONABLE WITH THE BETTER MOISTURE GETTING PUSHED OUT WELL AHEAD OF THE SYSTEM. THERE IS SOME CONCERN MONDAY WITH THE LESS PHASED ECM SOLUTION LIFTING A PIECE OF THE UPPER TROF OUT OF TEXAS...SENDING A SURFACE LOW NORTHEAST THROUGH THE OHIO VALLEY. THE ECMS PRECIP SHIELD WITH THIS FEATURE JUST MISSES THE SOUTHEAST CWFA MONDAY. MODELS DO AGREE ON A WEAK S/W RACING SOUTHEAST THROUGH THE DAKOTAS AND MN MONDAY AND MONDAY NIGHT WITH THE LATEST RUNS MOVING IT/S WEAK SURFACE LOW THROUGH IA AND FAVOR THE NORTHEAST CWFA FOR SOME LOW POPS FOR LIGHT SNOW. JUST A QUICK SHOT OF COLD AIR IS EXPECTED BEHIND THIS FEATURE WITH THE COLDEST TEMPS EXPECTED WEDNESDAY MORNING WITH LOWS IN THE SINGLE DIGITS AND TEENS. FOR THE END OF THE WEEK ANOTHER S/W MOVING OUT OF THE CANADIAN ROCKIES WILL SEND A SURFACE LOW EAST ALONG THE U.S. CANADIAN BORDER...DRAGGING A COLD FRONT THROUGH THE REGION WEDNESDAY NIGHT OR THURSDAY MORNING. THE FRONT SHOULD MOVE THROUGH DRY WITH A LARGE AREA OF HIGH PRESSURE OVER THE WESTERN GULF BLOCKING ANY MOISTURE RETURN. BUT THE NORTHEAST COULD SEE SOME LIGHT SNOW IN THE CYCLONIC FLOW AROUND THE SURFACE LOW AS IT MOVES INTO EASTERN CANADA THURSDAY NIGHT AND FRIDAY. MODELS SHOW THE SYSTEM DRAGGING DOWN ANOTHER CHUNK OF ARCTIC AIR WITH BOTH THE ECM AND GFS BRINGING H8 TEMPS AS COLD AS -22C OVER THE AREA THURSDAY NIGHT. THIS COULD RESULT IN SUBZERO TEMPERATURES OVER THE NORTH BY SATURDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1135 PM CST FRI JAN 10 2014 CONDITIONS EXPECTED TO TREND FROM LIFR/VLIFR TO IFR OVERNIGHT AND EARLY SATURDAY AM. MAY SEE VFR CONDITIONS DEVELOP IN DECREASING CLOUDS BY MID SATURDAY AM THROUGH MIDDAY... BUT THEN MORE LOW CLOUDS WITH MVFR CIGS ARE SHOWN BY SEVERAL MODELS TO PROPAGATE BACK DOWN ACROSS EASTERN IOWA AND NORTHWEST ILLINOIS SATURDAY AFTN ESPECIALLY NORTH OF I-80 WITH SECONDARY COLD FRONT. ALL AREAS EXPECTED TO CLEAR AND RETURN TO VFR BY SATURDAY NIGHT AS HIGH PRESSURE BUILDS IN. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA- JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BENTON- BUCHANAN-CLINTON-DELAWARE-DUBUQUE-JACKSON-JONES-LINN. IL...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR BUREAU-CARROLL- HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER- PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CARROLL-JO DAVIESS-STEPHENSON-WHITESIDE. MO...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR CLARK-SCOTLAND. && $$ UPDATE...05 SYNOPSIS...08 SHORT TERM...08 LONG TERM...DLF AVIATION...05
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
341 PM EST SAT JAN 11 2014 .SYNOPSIS... A COLD FRONT CROSSES THE AREA LATE TODAY. HIGH PRESSURE RETURNS FROM THE WEST TONIGHT INTO SUNDAY. ANOTHER COLD FRONT APPROACHES FROM THE WEST LATE MONDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... RADAR MOSAIC INDICATING LEADING EDGE OF SQUALL LINE MOVING A BIT QUICKER THAN PROGGED EVEN BY FASTEST HRRR SOLUTION. HAVE ACCORDINGLY MOVED SHRAS OUT A BIT FASTER WITH LATEST FORECAST PACKAGE. LATEST WEATHER ANALYSIS SHOWS ERODING WEDGE FRONT NOW JUST WEST OF RIC METRO...EXTENDING SOUTH INTO THE WESTERN CAROLINAS. VIA SPC MESOANALYSIS, LEADING EDGE OF CONVECTION NOW CROSSING INTO WESTERN EDGE OF TOR WATCH BOX...IN EFFECT FOR SE VA /HAMPTON ROADS AND TIDEWATER/ AND NE NC UNTIL 01Z. LATEST WX ANALYSIS SHOWS APPROACHING COLD FRONT CURRENTLY PUSHING INTO WESTERN VA AT 20Z. AS EXPECTED, SEEING A NARROW LINE OF FORCED LOW TOPPED CONVECTION OVER EASTERN VA ATTM. PER SPC MESOANALYSIS, MLCAPE ON THE ORDER OF 500-1000 J/KG OVER THE WARM SECTOR (ALONG WITH 50-70 KT OF 0-6KM SHEAR AND LOW/MIDLVL LAPSE RATES OF 6-7 C/KM) HAS PROVED SUFFICIENT TO MIX DOWN STRONG 60-80KT WINDS JUST ABOVE THE DECK (AKQ VWP SHOWING SW WINDS ~60KT BETWEEN 1-2KFT UP). AS CONVECTIVE LINE ROLLS EAST, EXPECT DAMAGING WIND THREAT TO CONTINUE ACROSS THE SE THROUGH EARLY EVENING. ONCE THE COLD FRONT CLEARS THE AREA THIS EVENING...DRIER AIR RETURNS TONIGHT WITH CLEARING SKIES. LOWS TONIGHT IN THE MID 30S TO MID 40S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/... SUNDAY LOOKS LIKE A TRANSITION DAY AS AN UPPER TROUGH PIVOTS OFFSHORE AND QUASI-ZONAL FLOW BRINGS A MOSTLY SUNNY SKY. WHILE NOT NEARLY AS MILD AS SATURDAY...MAXIMA REMAIN ~1 S.D. ABOVE NORMAL...CLIMBING INTO THE MID 50S TO NEAR 60. FLOW ALOFT BECOMES INCREASINGLY SW ON MONDAY...WITH GRADUALLY INCREASING HIGH CLOUDS LATER IN THE DAY AS AN UPPER LEVEL TROUGH BARRELS EASTWARD FROM THE PLAINS MONDAY INTO MONDAY NIGHT. WARM SW FLOW ALLOWS MAXIMA TO WARM BACK INTO THE UPR 50S TO LOW 60S. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... MEDIUM RANGE MODELS CONTINUE TO SHOW GENERAL AGREEMENT WITH AMPLIFIED...BUT PROGRESSIVE UPPER LEVEL PATTERN THRU THE EXTENDED PERIOD. LONGWAVE TROUGH WILL SLOWLY PROGRESS EWD OVER THE MIDWEST MON NIGHT-TUES MORNING AS ADDITIONAL SHORTWAVE ENERGY DIGS OVER THE NRN PLAINS INTO THE MIDWEST. LEADING ENERGY WILL LIFT FROM THE GULF STATES NEWD INTO THE MID-ATLANTIC REGION TUES. ECMWF REMAINS MORE AMPLIFIED WITH THE LEADING ENERGY THAN OTHER MODELS...RESULTING IN STRONGER SWLY FLOW AND RESULTANT MOISTURE ADVECTION INTO THE REGION. DIFFERENCES IN STRENGTH ALSO AFFECT PLACEMENT OF SFC LOW PRESSURE AND ATTENDANT WAVY FRONT OVER THE REGION. STRONGER ECMWF SOLUTION DEVELOP A WAVE ALONG THE FRONT OVER THE MID-ATLANTIC REGION WHILE THE WEAKER GFS QUICKLY PUSHES THE WEAK/WAVY FRONT OFFSHORE. TRENDED FORECAST TOWARD ECMWF BASED ON RUN TO RUN CONSISTENCY AND PV FIELDS (BETTER PLACEMENT OF SFC FEATURES WRT TO UPPER LEVEL FIELDS). WILL MAINTAIN CHANCE-HIGH END CHANCE POPS TUES MORNING-AFTERNOON...WITH PRECIP PUSHING OFFSHORE BY EARLY TUES NIGHT. MOISTURE REMAINS RATHER SHALLOW...AND WITH PROGRESSIVE NATURE OF THE SYSTEM...QPF AMOUNTS WILL GENERALLY BE LESS THAN ONE QUARTER OF AN INCH. MEANWHILE...ENERGY WILL CONTINUE TO DIG OVER THE MIDWEST INTO THE GULF STATES TUES INTO TUES NIGHT. ADDITIONAL SFC PATTERN PROBLEMS ARISE...MAINLY WITH THE PLACEMENT OF THE SFC LOW. HOWEVER...MODELS BOTH INDICATING A COLD FRONT WILL CROSS THE AREA WEDS. LEADING VORTICITY MAXIMA WILL LIFT FROM THE GULF STATES INTO THE MID-ATLANTIC WEDS...WITH A WAVE POSSIBLY DEVELOPING ALONG THE FRONT OVER THE REGION. THIS COULD LEAD TO THE DEVELOPMENT OF A COASTAL LOW OFF THE MID-ATLANTIC COAST WEDS AFTERNOON. STRONG DYNAMICS LOOK TO OVERCOME LIMITED MOISTURE FOR PRECIP WEDS. HOWEVER...LOW CONFIDENCE DUE TO MODEL SPREAD WILL RESULT IN ONLY SLIGHT CHANCE-LOW END CHANCE POPS ATTM. RAIN/SNOW MIX WILL BE POSSIBLE EARLY WED ACROSS THE FAR NW ZONES. TROUGH AXIS WILL PUSH OFFSHORE WED NIGHT-THURS MORNING AS SFC HIGH PRESSURE BUILDS EWD OVER THE DEEP SOUTH...RIDGING NWD INTO THE LOCAL AREA. NRN STREAM WILL REMAIN ACTIVE AS ANOTHER SHORTWAVE DIGS OVER THE GREAT LAKES REGION LATE THURS-FRI...PUSHING A COLD FRONT ACROSS THE OH VALLEY INTO THE MID-ATLANTIC REGION FRI. COLD CANADIAN HIGH PRESSURE WILL BUILD OVER THE MIDWEST-GULF STATES FRI-SAT AS COLD AIR RETURNS TO THE REGION. PACIFIC ORIGIN OF THE COLD AIR WILL PREVENT THE EXTREME TEMPS SEEN IN THE PREVIOUS WEEK. HIGH TEMPS WILL WARM ABOVE NORMAL TUES (UPPER 50S-LOW 60S) BEFORE FALLING BACK TO SEASONABLE NORMS THRU THE END OF THE WEEK. HIGHS SAT EXPECTED IN THE UPPER 30S-LOW 40S. MILD MON NIGHT (LOW-MID 40S) BEFORE RETURNING TO NEAR OR SLIGHTLY ABOVE SEASONABLE LOWS (LOW-MID 30S) THRU THE EXTENDED. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... MAIN CONCERN FOR THE AFTN/EVNG IS THE CONVECTION AHEAD OF THE APPROACHING CDFNT. S WNDS HAVE INCREASED (20-25 KT) AND WILL BECOME GUSTY (30 KT) INTO THIS AFTN AS THE LINE MAKES ITS WAY EAST. TIMING OF SIGNIFICANT AREA OF PCPN ON RADAR HAS THE PRECIP THROUGH THE REGION FROM MID AFTN THROUGH 00-03Z/12. THERE IS A CHANCE FOR SCATTERED THUNDERSTORMS AHEAD OF THE LINE DUE TO STRONG LOW LEVEL WINDS AND THE WARM/MOIST AIRMASS OVER NE NC AND SE VA. THUNDER AND STRONGER WINDS(40-50 KT) ALONG THE LINE ARE ALSO POSSIBLE AS THE CONVECTIVE LINE ENTERS THE MORE UNSTABLE AIRMASS. MVFR/IFR CONDITIONS WILL BE POSSIBLE IN THE VICINITY OF ANY SOWERS/THUNDERSTORMS. DRYING AND IMPROVING CONDS EXPECTED AFTER 03-06Z/12...AND VFR CONDS FOR SUN/MON...THEN DETERIORATING CONDITIONS ONCE AGAIN MON NIGHT INTO TUE. && .MARINE... COLD FRONT WILL CONTINUE TO CROSS THE REGION THIS AFTERNOON...CROSSING THE WATERS EARLY THIS EVENING. SLY WINDS WILL INCREASE TO 20-25 KT OVER THE BAY AND 25-30 KT OVER THE COASTAL WATERS IN ADVANCE OF THE FRONT...BEFORE BACKING TO THE W LATE THIS EVENING POST FRONTAL. LINE OF STRONG THUNDERSTORMS WILL ACCOMPANY THE FRONT...WHICH WILL LIKELY MIX DOWN STRONGER WINDS ALOFT. MAIN THREAT WILL BE WINDS IN EXCESS OF 34 KT...BUT ISOLATED WATER SPOUTS WILL ALSO BE POSSIBLE. SEAS WILL CONTINUE TO BUILD GENERALLY TO 5-8 FT (9-10 FT 20 NM OUT) THRU EARLY TONIGHT. BRIEF DOWNTURN IN WINDS EXPECTED IMMEDIATELY FOLLOWING THE FRONT THIS EVENING...BUT WLY WINDS WILL INCREASE RAPIDLY BACK TO SCA SPEEDS AND PERSIST THROUGH OVERNIGHT. SEAS WILL REMAIN 5-8 FT. HIGH PRESSURE BUILDS OVER THE GULF STATES TONIGHT-SUN MORNING...EXTENDING INTO THE MID-ATLANTIC REGION. THIS WILL ALLOW THE GRADIENT TO RELAX AND SCA SPEEDS TO SUBSIDE. SCA HEADLINES WILL REMAIN IN EFFECT THRU SUN MORNING. SEAS WILL REMAIN 4-6 FT THROUGH SUN AFTERNOON. HIGH PRESSURE WILL PUSH OFF THE SE COAST SUN NIGHT-MON AS SLY FLOW RETURNS TO THE WATERS. GRADIENT TIGHTENS OVER THE WATER MON NIGHT-TUES...WITH SLY WINDS INCREASING TO NEAR 15 KT. SEAS WILL ALSO BUILD TO 5+ FT IN THE NRN COASTAL WATERS. COLD FRONT WILL THEN CROSS THE WATERS MON NIGHT-TUES MORNING TIME FRAME...WITH ANOTHER STRONGER FRONT CROSSING THE WATERS WED. && .TIDES/COASTAL FLOODING... INCRSG S WNDS TO 20 TO 30 MPH TDA AHD OF APPROACHING CDFNT HAS PUSHED WATER LEVELS UP OVR PORTIONS OF THE CNTRL CHES BAY...MNLY INVOF LWR MD ERN SHORE (DORCHESTER TO SOMERSET COUNTIES) AND ALG THE NORTHERN SHORE OF ACCOMACK COUNTY IN VA. XPCG WTR LEVELS FOR HI TIDES THROUGH THIS AFTN TO BE ABT 1 TO 1.5 FT ABV NRML...PTNTLLY REACHING 3 FT MLLW AT CAMBRIDGE (MINOR FLOODING 3.5 FT MLLW) AND BISHOPS HEAD MD (MINOR FLOODING 3.2 FT MLLW)...THEN DEPARTURES AVGG 0.5 TO 1 FT ABV NRML FOR THE HIGH TIDE TNGT IN THOSE AREAS. && .CLIMATE... RECORD HIGH TEMPERATURE FOR THE DATE TIED AT SBY (1975). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ635>637. SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR ANZ630>634-638. SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR ANZ650-652-654- 656-658. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...JDM/MAM LONG TERM...SAM AVIATION...ALB/DAP MARINE...SAM TIDES/COASTAL FLOODING... CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
339 PM EST SAT JAN 11 2014 .SYNOPSIS... A COLD FRONT CROSSES THE AREA LATE TODAY. HIGH PRESSURE RETURNS FROM THE WEST TONIGHT INTO SUNDAY. ANOTHER COLD FRONT APPROACHES FROM THE WEST LATE MONDAY. && .NEAR TERM /THROUGH TONIGHT/... RADAR MOSAIC INDICATING LEADING EDGE OF SQUALL LINE MOVING A BIT QUICKER THAN PROGGED EVEN BY FASTEST HRRR SOLUTION. HAVE ACCORDINGLY MOVED SHRAS OUT A BIT FASTER WITH LATEST FORECAST PACKAGE. LATEST WEATHER ANALYSIS SHOWS ERODING WEDGE FRONT NOW JUST WEST OF RIC METRO...EXTENDING SOUTH INTO THE WESTERN CAROLINAS. VIA SPC MESOANALYSIS, LEADING EDGE OF CONVECTION NOW CROSSING INTO WESTERN EDGE OF TOR WATCH BOX...IN EFFECT FOR SE VA /HAMPTON ROADS AND TIDEWATER/ AND NE NC UNTIL 01Z. LATEST WX ANALYSIS SHOWS APPROACHIGN COLD FRONT CURRENTLY PUSHING INTO WESTERN VA AT 20Z. AS EXPECTED, SEEING A NARROW LINE OF FORCED LOW TOPPED CONVECTION OVER EASTERN VA ATTM. PER SPC MESOANALYSIS, MLCAPE ON THE ORDER OF 500-1000 J/KG OVER THE WARM SECTOR (ALONG WITH 50-70 KT OF 0-6KM SHEAR AND LOW/MIDLVL LAPSE RATES OF 6-7 C/KM) HAS PROVED SUFFICIENT TO MIX DOWN STRONG 60-80KT WINDS JUST ABOVE THE DECK (AKQ VWP SHOWING SW WINDS ~60KT BETWEEN 1-2KFT UP). AS CONVECTIVE LINE ROLLS EAST, EXPECT DAMAGING WIND THREAT TO CONTINUE ACROSS THE SE THROUGH EARLY EVENING. ONCE THE COLD FRONT CLEARS THE AREA THIS EVENING...DRIER AIR RETURNS TONIGHT WITH CLEARING SKIES. LOWS TONIGHT IN THE MID 30S TO MID 40S. && .SHORT TERM /SUNDAY THROUGH MONDAY/... SUNDAY LOOKS LIKE A TRANSITION DAY AS AN UPPER TROUGH PIVOTS OFFSHORE AND QUASI-ZONAL FLOW BRINGS A MOSTLY SUNNY SKY. WHILE NOT NEARLY AS MILD AS SATURDAY...MAXIMA REMAIN ~1 S.D. ABOVE NORMAL...CLIMBING INTO THE MID 50S TO NEAR 60. FLOW ALOFT BECOMES INCREASINGLY SW ON MONDAY...WITH GRADUALLY INCREASING HIGH CLOUDS LATER IN THE DAY AS AN UPPER LEVEL TROUGH BARRELS EASTWARD FROM THE PLAINS MONDAY INTO MONDAY NIGHT. WARM SW FLOW ALLOWS MAXIMA TO WARM BACK INTO THE UPR 50S TO LOW 60S. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... MEDIUM RANGE MODELS CONTINUE TO SHOW GENERAL AGREEMENT WITH AMPLIFIED...BUT PROGRESSIVE UPPER LEVEL PATTERN THRU THE EXTENDED PERIOD. LONGWAVE TROUGH WILL SLOWLY PROGRESS EWD OVER THE MIDWEST MON NIGHT-TUES MORNING AS ADDITIONAL SHORTWAVE ENERGY DIGS OVER THE NRN PLAINS INTO THE MIDWEST. LEADING ENERGY WILL LIFT FROM THE GULF STATES NEWD INTO THE MID-ATLANTIC REGION TUES. ECMWF REMAINS MORE AMPLIFIED WITH THE LEADING ENERGY THAN OTHER MODELS...RESULTING IN STRONGER SWLY FLOW AND RESULTANT MOISTURE ADVECTION INTO THE REGION. DIFFERENCES IN STRENGTH ALSO AFFECT PLACEMENT OF SFC LOW PRESSURE AND ATTENDANT WAVY FRONT OVER THE REGION. STRONGER ECMWF SOLUTION DEVELOP A WAVE ALONG THE FRONT OVER THE MID-ATLANTIC REGION WHILE THE WEAKER GFS QUICKLY PUSHES THE WEAK/WAVY FRONT OFFSHORE. TRENDED FORECAST TOWARD ECMWF BASED ON RUN TO RUN CONSISTENCY AND PV FIELDS (BETTER PLACEMENT OF SFC FEATURES WRT TO UPPER LEVEL FIELDS). WILL MAINTAIN CHANCE-HIGH END CHANCE POPS TUES MORNING-AFTERNOON...WITH PRECIP PUSHING OFFSHORE BY EARLY TUES NIGHT. MOISTURE REMAINS RATHER SHALLOW...AND WITH PROGRESSIVE NATURE OF THE SYSTEM...QPF AMOUNTS WILL GENERALLY BE LESS THAN ONE QUARTER OF AN INCH. MEANWHILE...ENERGY WILL CONTINUE TO DIG OVER THE MIDWEST INTO THE GULF STATES TUES INTO TUES NIGHT. ADDITIONAL SFC PATTERN PROBLEMS ARISE...MAINLY WITH THE PLACEMENT OF THE SFC LOW. HOWEVER...MODELS BOTH INDICATING A COLD FRONT WILL CROSS THE AREA WEDS. LEADING VORTICITY MAXIMA WILL LIFT FROM THE GULF STATES INTO THE MID-ATLANTIC WEDS...WITH A WAVE POSSIBLY DEVELOPING ALONG THE FRONT OVER THE REGION. THIS COULD LEAD TO THE DEVELOPMENT OF A COASTAL LOW OFF THE MID-ATLANTIC COAST WEDS AFTERNOON. STRONG DYNAMICS LOOK TO OVERCOME LIMITED MOISTURE FOR PRECIP WEDS. HOWEVER...LOW CONFIDENCE DUE TO MODEL SPREAD WILL RESULT IN ONLY SLIGHT CHANCE-LOW END CHANCE POPS ATTM. RAIN/SNOW MIX WILL BE POSSIBLE EARLY WED ACROSS THE FAR NW ZONES. TROUGH AXIS WILL PUSH OFFSHORE WED NIGHT-THURS MORNING AS SFC HIGH PRESSURE BUILDS EWD OVER THE DEEP SOUTH...RIDGING NWD INTO THE LOCAL AREA. NRN STREAM WILL REMAIN ACTIVE AS ANOTHER SHORTWAVE DIGS OVER THE GREAT LAKES REGION LATE THURS-FRI...PUSHING A COLD FRONT ACROSS THE OH VALLEY INTO THE MID-ATLANTIC REGION FRI. COLD CANADIAN HIGH PRESSURE WILL BUILD OVER THE MIDWEST-GULF STATES FRI-SAT AS COLD AIR RETURNS TO THE REGION. PACIFIC ORIGIN OF THE COLD AIR WILL PREVENT THE EXTREME TEMPS SEEN IN THE PREVIOUS WEEK. HIGH TEMPS WILL WARM ABOVE NORMAL TUES (UPPER 50S-LOW 60S) BEFORE FALLING BACK TO SEASONABLE NORMS THRU THE END OF THE WEEK. HIGHS SAT EXPECTED IN THE UPPER 30S-LOW 40S. MILD MON NIGHT (LOW-MID 40S) BEFORE RETURNING TO NEAR OR SLIGHTLY ABOVE SEASONABLE LOWS (LOW-MID 30S) THRU THE EXTENDED. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... MAIN CONCERN FOR THE AFTN/EVNG IS THE CONVECTION AHEAD OF THE APPROACHING CDFNT. S WNDS HAVE INCREASED (20-25 KT) AND WILL BECOME GUSTY (30 KT) INTO THIS AFTN AS THE LINE MAKES ITS WAY EAST. TIMING OF SIGNIFICANT AREA OF PCPN ON RADAR HAS THE PRECIP THROUGH THE REGION FROM MID AFTN THROUGH 00-03Z/12. THERE IS A CHANCE FOR SCATTERED THUNDERSTORMS AHEAD OF THE LINE DUE TO STRONG LOW LEVEL WINDS AND THE WARM/MOIST AIRMASS OVER NE NC AND SE VA. THUNDER AND STRONGER WINDS(40-50 KT) ALONG THE LINE ARE ALSO POSSIBLE AS THE CONVECTIVE LINE ENTERS THE MORE UNSTABLE AIRMASS. MVFR/IFR CONDITIONS WILL BE POSSIBLE IN THE VICINITY OF ANY SOWERS/THUNDERSTORMS. DRYING AND IMPROVING CONDS EXPECTED AFTER 03-06Z/12...AND VFR CONDS FOR SUN/MON...THEN DETERIORATING CONDITIONS ONCE AGAIN MON NIGHT INTO TUE. && .MARINE... SSE WNDS PREVAIL OVR THE WTRS ATTM...AND WILL CONT TO INCRS THIS MRNG INTO THIS AFTN AHD OF APPROACHING CDFNT FM THE W. WNDS AT 925 MB INCRS TO ABT 50-60KT FM ABT 18-21Z/11...HWVR WAA AND COLD WTRS WILL LMT TRANSFER OF THOSE HIGHER SPDS TO THE WTR. SPDS INCRSG TO 20 TO 30 KT OVR THE WTRS BY THIS AFTN...KEEPING GUSTS BLO GALES (34 KT) FOR NOW...HWVR WOULD NOT RULE OUT A VERY SHORT PD LT THIS AFTN/EVE...ESP ACCOMPANYING CONVECTION...FOR GUSTS ABV GALES. WAVES ON THE BAY TO BUILD TO 3-5 FT...SEAS TO 6-10 FT THIS AFTN AND CONT INTO THE E. THE CDFNT PUSHES OFF THE CST AND E OF THE WTRS AFT MDNGT...SWINGING THE WNDS TO W. SFC HI PRES WILL BUILD E OVR SE CONUS TNGT- SUN...EXTENDING NWD OVER THE LOCAL AREA WTRS BY LT SUN MRNG/AFTN. THIS WILL ALLOW WINDSPEEDS TO DIMINISH AND SEAS/WAVES TO SUBSIDE. AS HI PRES PUSHES OFF THE SE CST SUN NGT...FLO RETURNS TO THE S. UNSETTLED CONDS WILL RETURN TO THE WTRS TUE-WED. SCAS RMNG UP FOR ALL WTRS THROUGH LT TNGT/SUN MRNG ON THE RIVERS/BAY AND SND...AND ON THE OCN THROUGH SUN AFTN. && .TIDES/COASTAL FLOODING... INCRSG S WNDS TO 20 TO 30 MPH TDA AHD OF APPROACHING CDFNT HAS PUSHED WATER LEVELS UP OVR PORTIONS OF THE CNTRL CHES BAY...MNLY INVOF LWR MD ERN SHORE (DORCHESTER TO SOMERSET COUNTIES) AND ALG THE NORTHERN SHORE OF ACCOMACK COUNTY IN VA. XPCG WTR LEVELS FOR HI TIDES LATE THIS MRNG THROUGH THIS AFTN TO BE ABT 1 TO 1.5 FT ABV NRML...PTNTLLY REACHING 3 FT MLLW AT CAMBRIDGE (MINOR FLOODING 3.5 FT MLLW) AND BISHOPS HEAD MD (MINOR FLOODING 3.2 FT MLLW)...THEN DEPARTURES AVGG 0.5 TO 1 FT ABV NRML FOR THE HIGH TIDE TNGT IN THOSE AREAS. && .CLIMATE... RECORD HIGH TEMPERATURE FOR THE DATE TIED AT SBY (1975). && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ635>637. SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR ANZ630>634-638. SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR ANZ650-652-654- 656-658. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...JDM/MAM LONG TERM...SAM AVIATION...ALB/DAP MARINE...ALB/SAM TIDES/COASTAL FLOODING... CLIMATE...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1128 PM CST FRI JAN 10 2014 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 255 PM CST FRI JAN 10 2014 BEGINNING TO LOOK LIKE FZDZ MIGHT BE ABOUT ALL THE MPX AREA SEES FROM THE UPPER WAVES WORKING ACROSS THE CENTRAL CONUS NOW. THE PROBLEM CONTINUES TO BE A DELAYED PHASING OF A NORTHERN STREAM WAVE CURRENTLY HEADING FOR NW MN AND A SRN STREAM WAVE THAT IS MOVING UP OUT OF IA TOWARD WI. THESE TWO SYSTEMS DO NOT REALLY LOOK TO BECOME ONE UNTIL SAT MORNING OVER MICH. THE RUB THERE IS THAT THE SRN STREAM WAVE IS THE ONE WITH ALL OF THE MOISTURE AND THEREFORE PRECIPITATION AND WITH THESE SYSTEMS NOT PHASING UNTIL SATURDAY...WE ARE SEEING THE PRECIPITATION MOVING THROUGH FASTER AND FARTHER EAST TODAY/TONIGHT. RUNS OF THE HOPWRF TODAY HAVE BEEN PROGRESSIVELY INCHING A DEFORMATION BAND EAST WITH TIME AND WITH THE 15Z RUN ALL 4 MEMBERS ARE NOW SHOWING A BAND OF ENHANCED PRECIP FALLING FROM ABOUT DECORAH...IA UP TOWARD WAUSAU...EAST OF THE MPX CWA. ON RADAR...THERE IS A CLUSTER OF HIGHER RETURNS THAT MATCHES UP WELL WITH THESE PRECIPITATION SWATHS AND WITH THE HRRR PICKING UP ON THIS SCENARIO NOW AS WELL...CONFIDENCE IS BEGINNING TO INCREASE THAT THIS SYSTEM WILL BE A DUD IN THE SNOWFALL DEPARTMENT FOR THE MPX AREA. WITH ALL OF THAT SAID...STILL ANTICIPATE SOME LIGHT SNOW TO DEVELOP MAINLY EAST OF THE I-35 CORRIDOR AS THE SFC TROUGH THAT IS STILL HANGING OUT ALONG THE MN/DAKOTAS BORDER SLIDES EAST THIS EVENING...MEETING UP WITH THE DEEPER MOISTURE STREAMING NORTH INTO WI. HAVE FOLLOWED THE IDEA OF THE HRRR AND OTHER HI-RES MODELS WHICH SHOW JUST LIGHT QPF/SIMULATED REFLECTIVITY DEVELOPING OVER ERN MN WITHIN THE NEXT COUPLE OF HOURS BEFORE SLOWLY SLIDING EAST. SAID SFC TROUGH WILL CLEAR THE MPX AREA AROUND 9Z...WITH ANY SNOW LIKELY CUTTING OFF AFTER THAT. BASICALLY...THERE MIGHT BE ONE OR TWO LUCKY FOLKS OUT THERE THAT PICK UP A HALF INCH OF SNOW OUT OF THIS...OTHERWISE IT IS JUST A SEA OF LOW CLOUDS AND HAZE UNTIL THE SFC TROUGH CLEARS AND WINDS BECOME WNW. AS FOR TONIGHT...FOLLOWED THE IDEA OF THE RAP AND NAM OF SKIES SCATTERING OUT AT LEAST FOR A LITTLE WHILE AS BOUNDARY LAYER WINDS BECOME MORE WRLY...MUCH LIKE WHAT HAS BEEN SEEN TODAY ACROSS THE DAKOTAS. THINKING WE WOULD SEE SOME CLEARING...DID FOLLOW THE IDEA MOST GUIDANCE SHOWS OF KNOCKING LOWS BACK INTO THE LOWER TEENS FOR MUCH OF THE AREA WEST OF TWIN CITIES. NOT MUCH TO SAY ABOUT SATURDAY...OTHER CLOUDS CURRENTLY MOVING INTO NRN NODAK SWEEP THROUGH HERE DURING THE MORNING/EARLY AFTERNOON WITH HIGHS STILL LOOKING TO NESTLE UP INTO THE 5-10 DEGREES ABOVE NORMAL RANGE. SO MADE ONLY MINOR CHANGES TO EXISTING FORECAST...MAINLY JUST BLENDING IN LATEST BIAS CORRECTED MODEL DATA. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 255 PM CST FRI JAN 10 2014 LONGER TERM TRENDS CONTINUE TO INDICATE RATHER PROGRESSIVE UPPER LEVEL FLOW PATTERN OVER THE AREA DURING THE PERIOD. COOLING TREND APPEARS TO TAKE HOLD BY LATE IN THE PERIOD AS ANOTHER AREA OF COLD AIR DIVES SOUTHEAST ALONG THE AMPLIFYING HUDSON BAY VORTEX. A LIGHT MIX OF PRECIPITATION MAY STILL OCCUR UNDER STRONG WAA PATTERN UNDER STRONG 130KT H25 JET SUNDAY INTO SUNDAY NIGHT. WARMING ALOFT INDICATES FAVORABLE THICKNESS FOR POSSIBLE LIGHT ZR-/ZL- INTO THE DAY AS SURFACE TEMPERATURES WARM THROUGH THE LOWER 30S DURING TH DAY. WHATEVER IS LEFT INTO THE EVENING/SUNDAY OVERNIGHT WILL CHANGE OVER TO SNOW...BUT ONLY LIGHT QPF AMOUNTS ARE INDICATED. DETERMINISTIC EC AND GFS CONTINUE TO SHOW ANOTHER WEAK CLIPPER TYPE SYSTEM DIVING SOUTHEAST ALONG WEAK SURFACE BOUNDARY... AFFECTING MAINLY SOUTHERN CWA DURING THE MONDAY INTO MONDAY NIGHT PERIOD. TIMING IS IN QUESTION...WITH THE 12Z GFS A BIT FASTER THAN THE 12Z EC. WONT GET TOO CUTE ON TIMING OF THIS SYSTEM NOW...BUT WE COULD SEE SOME LIGHT SNOW ACCUMULATION WITH THIS AS IT PASSES THROUGH. BRIEF SHOT OF COLDER AIR ARRIVES FOR TUESDAY/TUESDAY NIGHT AHEAD OF NEXT SURGE OF PACIFIC AIR FOR WEDNESDAY. MODELS INDICATE THE NEXT MAIN SURGE OF ARCTIC AIR ARRIVES THURSDAY AND WILL LINGER THROUGH THE END OF THE PERIOD AS THE EASTERN CONUS TROUGH DIGS SOUTHEAST. AT THE MOMENT...IT DOESNT APPEAR TO BE AS COLD AS THE LAST WILL HAVE TO MONITOR DEVELOPMENT OF THE TROUGH INTO NEXT WEEK. COULD SEE SOME LIGHT SNOW/SNOW SHOWERS WITH THIS AS IT DIVES SOUTHEAST AND THE COLD AIR ARRIVES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1054 PM CST FRI JAN 10 2014 SEVERAL COMPLICATING ISSUES ACRS THE COVERAGE AREA AFFECTING THE TAFS TONIGHT. IN WRN MN...FOG. IN CENTRAL-ERN MN...FOG AND LOW CEILINGS. IN WRN WI...LOW CEILINGS AND LEFTOVER -FZDZ/-SN. OVERALL...IFR-OR-WORSE CONDITIONS WILL BE COMMONPLACE THROUGH THE FIRST SEVERAL HOURS OF THE TAF PERIOD. CONDITIONS MAY WELL BE FLUCTUATING SO AMENDMENTS MAY WELL BE FAIRLY FREQUENT TO UPDATE THE FIRST 6 HRS. BY DAYBREAK...PRECIP AND FOG SHOULD NO LONGER BE ISSUES BUT SOME MVFR CIGS MAY REMAIN...ESP IN WRN WI. OVER MN...THE SHIFT TO WLY WINDS WILL AID IN BRINGING IN SOME DRIER AIR TO HELP SCOUR OUT THE LLVL MOISTURE. VFR CONDS THRU LATE MRNG THEN ANOTHER SWATH OF LOWER CLOUDS ON THE BACKSIDE OF AN UPR TROF WILL MOVE THRU. CLOUDS LOOK TO BE MAINLY LOW-END VFR...POSSIBLY MVFR. BY LATE DAY...VFR CONDS PREVAIL WHILE WINDS BACK TO SSE AND DIMINISH IN SPEED. KMSP...IFR CONDS TO START WITH STILL SOME OCNL BOUTS OF -FZDZ FOR THE FIRST COUPLE OF HOURS...THEN CONDS IMPROVE THRU THE REST OF THE PRE-DAWN HOURS. VFR FOR MIDDAY...THEN ADDITIONAL CEILINGS RETURN MID-TO-LATE DAY. AM NOT THINKING THESE WILL BE MVFR BUT THAT POSSIBILITY CERTAINLY CANNOT BE RULED OUT. AFTER THE SWATH OF MIDLVL CEILINGS EXIT BY LATE AFTN...VFR CONDS EXPECTED TMRW NIGHT. WINDS WILL SWING AROUND TO WLY...WHICH WILL AID IN CLEARING OUT THE LOW CLOUDS AND FOG TNGT...THEN REMAIN WLY THRU THE DAY BEFORE BACKING SAT EVE. /OUTLOOK FOR KMSP/ SUN...VFR. WINDS SW 10-15 KTS. MON...VFR. CHC MVFR/-SN OVERNIGHT. WINDS W-SW 5-10 KTS. TUE...VFR. CHC MVFR CIGS. WINDS NW 15G25 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...DWE AVIATION...JPC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1152 PM CST Fri Jan 10 2014 .UPDATE: Issued at 945 PM CST Fri Jan 10 2014 The new swath of rain with the warm conveyor was centered from just west of Litchfield through the St. Louis metro into southeast MO. It is moving rather quickly to the northeast and should exit much if not all of MO before midnight as the progressive upstream trof continues to advance east and dry air moves in aloft. Adjustments this evening were just temporal trends with the rain and temperatures. During the overnight period and more specifically after 09z I increased the pops through central and northeast MO. There is a growing area of rain and snow across eastern KS due to what appears to be a mid-upper level deformation zone. The RAP and HRRR rotate this precipitation into the aforementioned area after 09z and weaken it by 12z. My pops while higher than the previous forecast may not be high enough if it maintains more identity. Glass && .SHORT TERM: (Through Tonight) Issued at 1217 PM CST Fri Jan 10 2014 Focus will be precip tonight, but in two areas. First, the ongoing RA that will be moving out of the region late tonight. The second, is precip associated with the upper trof currently over the Plains. Believe ongoing precip will be confined to the ern half of the CWA at the beginning of the period. Precip shud continue pushing quickly ewd and only be in the far ern counties by Midnight. Not much change in the way of QPF thru tonight. The other area of precip may be across nrn portions of the CWA late tonight as the upper trof moves thru. Mdls are in fairly good agreement with timing/placement of this feature. However, mdls suggest a lack of available moisture will prevent any precip by the time the trof reaches the CWA. POPs or mention of flurries may need to be added to these areas late tonight. As for temps, expect temps to remain steady or even rise ahead of the cdfnt as it moves thru the area. Resultant temps are around the warmer guidance as airmass behind the fnt is not that cold based on upstream obs. Tilly .LONG TERM: (Saturday through Next Friday) Issued at 251 PM CST Fri Jan 10 2014 (Saturday through Monday) After further critique of the latest guidance for Sat, have decided to add slight chance for SN continuing into the early morning hours. There is still a lot of uncertainty if enuf moisture will remain to produce SN, but believe it is worthy of slight chances. If the SN does occur, with the relatively warm bndy temps, do not anticipate much in the way of accumulations. Next system reaches the region on Sun night into Mon as another deep trof approaches the region. For now, have kept POPs in the low chance range due to a fair amount of uncertainty among guidance regarding strength and placement of the trof and sfc reflection. Continued trend twd warm temps with upper ridging moving into the region. (Tuesday through Friday) Period begins with a focus on precip chances on Tues as a clipper approaches the area. Each mdl has a different soln with vast differences between them. Given the system is a clipper, will likely have low confidence in any given soln until much closer to Tues. For now, will just add slight chances for SN and refine the fcst as time approaches. As for temps, have tried to trend twd a compromise of guidance. Have low confidence in any single soln as area remains under meridional flow, producing warming and cooling periods. Tilly && .AVIATION: (For the 06z TAFs through 06z Saturday Night) Issued at 1128 PM CST Fri Jan 10 2014 Satellite imagery and upstream surface obs suggest that cigs will remain IFR to MVFR overnight before improving to VFR during the morning due to the arrival of drier air and the onset of mixing. The cold front which has already moved through KCOU/KUIN will reach KSUS/KCPS within a few hours. Winds will turn westerly behind the front and remain westerly for most of the TAF period. Decreasing winds near an approaching surface high, very moist grounds, and radiational cooling will probably cause fog and/or stratus to redevelop on Saturday night. A period of rain or snow is possible at KCOU this morning between 09-12z, but confidence is too low to include in the TAF. Later shifts will need to monitor upstream trends across KS and western MO. Specifics for KSTL: Satellite imagery and upstream surface obs suggest that currently variable cigs will settle to MVFR overnight before improving to VFR during the morning due to the arrival of drier air and the onset of mixing. Winds will turn westerly behind a cold front within a few hours and then remain westerly for most of the TAF period. Decreasing winds near an approaching surface high, very moist grounds, and radiational cooling will probably cause fog and/or stratus to redevelop on Saturday night. Kanofsky && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
908 AM MST SAT JAN 11 2014 .UPDATE... FORECAST REMAINS ON TRACK THIS MORNING...THEREFORE ONLY MINOR CHANGES MADE. INSPECTION OF MESOSCALE MODELS THIS MORNING...INCLUDING THE HRRR AND SSEO...CONFIRM THE FORECAST THINKING OF STRONG WINDS FOR LIVINGSTON TO BIG TIMBER TO HARLOWTON WHERE HIGHLIGHTS ARE ALREADY IN PLACE. FURTHERMORE...THESE MODELS PRODUCE STRONG WINDS ON THE MOUNTAINS ABOVE RED LODGE...AND SHOW SOME HINTS OF MOUNTAIN WAVE ACTIVITY BRINGING STRONGER WINDS INTO LOWER ELEVATIONS OF CARBON COUNTY. ANOTHER AREA OF CONCERN FOR STRONG WINDS THIS AFTERNOON AND EVENING IS THE FORT SMITH AREA AND LOCATIONS IN THE BIG HORN MOUNTAINS. HAVE INCREASED WINDS THERE BASED ON MAGNITUDE OF 700 MB WINDS COMING ACROSS AND INDICATIONS FROM HIGH RES MODELS. CHURCH && .SHORT TERM...VALID FOR TDY AND SUN... MAIN FORECAST CHALLENGE FOR THE SHORT-TERM PERIOD CONTINUES TO BE WINDS. INHERITED A WIND ADVISORY FOR GAP FLOW AREAS AND BIG TIMBER...HIGH WIND WATCH FOR RED LODGE FOR MOUNTAIN WAVES...AND HIGH WIND WATCH FOR WHEATLAND AND JUDITH GAP. PATTERN FEATURES A JET MOVING INTO THE AREA TODAY USHERING SHORTWAVE ENERGY INTO THE AREA LATE TODAY THROUGH SUN WHEN ANOTHER JET MOVES IN FROM BC AND THE PACIFIC NW. THIS FAST FLOW WILL BRING STRONG WINDS ALOFT TO THE REGION WITH 700 MB WINDS RANGING FROM 50 TO 75 KT THROUGH THE PERIOD. THE STRONGEST WINDS WERE FORECAST TO GET CLOSEST TO THE SURFACE ON SUN MORNING ACROSS THE AREA. SUN ALSO LOOKED LIKE THE PERIOD WITH THE BEST MIXING POTENTIAL BASED ON BUFKIT...BUT LIFT FROM THE DYNAMICS WILL HINDER THE MIXING DOWN OF THE STRONGEST WINDS. REGARDING THE SURFACE GRADIENT...IT LOOKED THE MOST SUPPORTIVE FOR GAP WINDS THIS MORNING...THEN TURNED MORE SW TO NE THROUGH SUN NIGHT. THE GRADIENT ORIENTATION DID NOT SUPPORT STRONG WINDS IN WHEATLAND COUNTY...HOWEVER THERE WILL PROBABLY BE ENOUGH MIXING FOR THIS AREA TO REACH HIGH WIND CRITERIA AT TIMES. OPTED TO GO WITH A HIGH-END WIND ADVISORY FOR THE GAP AREAS AND BIG TIMBER. THIS CAN ALWAYS BE UPGRADED TO A WARNING IN LATER PERIODS IF NEEDED. WILL GO WITH A HIGH WIND WARNING FOR JUDITH GAP AND WHEATLAND COUNTY. REGARDING RED LODGE...NOT ALL THE FACTORS WERE PRESENT FOR A MOUNTAIN WAVE...HOWEVER THERE WAS GOOD SUBSIDENCE...MOUNTAIN TOP STABILITY AND STRONG WIND. THUS WILL GO WITH A WARNING THERE AND EMPHASIZE STRONG WIND IN THE MOUNTAINS ABOVE RED LODGE. MADE A FEW ADJUSTMENTS TO POPS THROUGH THE PERIOD BASED ON LATEST MODEL MOISTURE FIELDS. WILL NOT MENTION FREEZING RAIN THIS MORNING AS TEMPERATURES WERE REMAINING CLOSE TO FREEZING AND THE SSEO DID NOT SUPPORT A GOOD CHANCE OF FREEZING RAIN. WILL KEEP HIGH POPS IN THE MOUNTAINS PER PREVIOUS FORECAST. A WARM FRONT WILL MOVE THROUGH THE E TODAY ALLOWING TEMPERATURES TO REACH THE 40S TO AROUND 50 DEGREES. A COLD FRONT LATER TODAY AND A SECOND FRONT ON SUN WILL BRING COOLER WEATHER TO THE REGION. MADE ONLY SLIGHT TEMPERATURE ADJUSTMENTS TODAY TO TREND BETTER FROM YESTERDAY/S READINGS. ARTHUR .LONG TERM...VALID FOR MON...TUE...WED...THU...FRI... PRESSURE GRADIENTS ENSURING WINDY CONDITIONS WILL IN PLACE THROUGHTHE EXTENDED WITH JET STREAM SUPPORT STRONGEST ON MONDAY BUT STILL POTENT TUESDAY AND WEDNESDAY BEFORE WANING LATER IN THE WEEK. FOR MONDAY ORIENTATION OF THE JET IS NOT QUITE AS FAVORABLE AS PREVIOUS RUNS INDICATED WHICH IS EVIDENT IN WEAKER SURFACE PRESSURE RISES. BUFKIT DATA SHOWS A LOT MORE ASCENT MONDAY AFTERNOON SO IT MAY BE TOUGH FOR VERY HIGH WINDS TO MATERIALIZE. HOWEVER THE 850 MB WINDS CONTINUE TO RUN IN THE 65 KT RANGE ACROSS THE REGION SO FORECAST DOES NOT HAVE TO CHANGE VERY MUCH FOR VERY STRONG WINDS TO MATERIALIZE. TUESDAY FAVORS GAP FLOW AREAS AND LESS ON THE PLAINS WITH PRESSURE FALLS BUT STILL MIXED GUSTS WILL KEEP BREEZY CONDITIONS AROUND. WEDNESDAY WILL HAVE TO BE WATCHED BECAUSE SOME STRONGER PRESSURE RISES MATERIALIZE AS A DEEP SURFACE LOW MOVES THROUGH SASKATCHEWAN. 700MB WINDS ARE VERY STRONG ACROSS SOUTHEAST MONTANA AND FOR SHERIDAN COUNTY SO WILL HAVE TO WATCH FOR PRESSURE RISES TO SUPPORT THE WINDS MIXING DOWN. THURSDAY AND FRIDAY HAVE A SLACKENING OF PRESSURE GRADIENTS WITH INCREASING WINDS AGAIN FOR SATURDAY. PRECIPITATION CHANCES LOOK BEST ON MONDAY DUE TO JET SUPPORT AND AN UNSTABLE ATMOSPHERE BUT DOWNSLOPE INFLUENCES WILL LIMIT PRECIP AMOUNTS IN WESTERN LOWER ELEVATIONS. BETTER CHANCES FOR SHOWERS WILL BE OVER SOUTHEAST MONTANA. LOOKS DRIER FOR MOST OF THE WEEK WITH PRECIPITATION LIMITED TO MOUNTAIN OROGRAPHICS. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE PERIOD WITH EROSION OF THE SNOWPACK BECOMING CRITICAL TO NIGHTTIME MINIMUM TEMPERATURES LATER IN THE WEEK. BORSUM && .AVIATION... SOUTHWEST WINDS WILL GUST TO 60KTS TODAY AT KLVM. WEST TO SOUTHWEST WINDS WILL GUST TO 50KTS FROM BIG TIMBER TO HARLOWTON. WINDS WILL INCREASE AT KBIL THIS AFTERNOON TOO WITH SOME GUSTS TO 25KTS. MOUNTAINS WILL BE OBSCURED WITH A STEADY STREAM OF MOISTURE PRODUCING SNOWFALL OVER THE WEST FACING SLOPES. OTHERWISE...VFR CONDITIONS ARE ANTICIPATED TODAY. TWH && .PRELIMINARY POINT TEMP/POPS... TDY SUN MON TUE WED THU FRI ------------------------------------------------------- BIL 045 034/043 032/048 035/046 030/050 026/039 023/041 2/J 21/N 02/W 31/N 11/N 11/N 11/B LVM 048 033/040 033/045 035/045 033/048 030/039 031/042 2/W 32/W 22/W 21/N 11/N 21/N 11/B HDN 043 027/040 024/044 027/041 023/047 019/035 013/036 2/J 22/W 23/W 31/N 11/N 11/B 11/B MLS 041 028/035 021/040 025/038 023/044 019/032 013/033 2/J 32/W 24/W 32/J 01/N 11/N 11/B 4BQ 043 028/036 024/043 026/040 024/048 021/034 015/036 2/J 22/W 24/W 32/J 01/N 11/N 11/B BHK 043 029/032 017/040 024/037 020/043 018/030 012/034 1/E 32/J 24/W 22/J 01/N 11/N 11/B SHR 048 025/038 021/043 026/044 023/050 020/038 017/042 0/N 22/W 22/W 31/N 11/U 11/B 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...HIGH WIND WARNING IN EFFECT UNTIL MIDNIGHT MST MONDAY NIGHT FOR ZONES 28-63. HIGH WIND WATCH IN EFFECT FROM MONDAY MORNING THROUGH MONDAY EVENING FOR ZONES 29-34-35-38-39-42-56-57. WIND ADVISORY IN EFFECT UNTIL 5 AM MST TUESDAY FOR ZONES 41-65-66. HIGH WIND WARNING IN EFFECT UNTIL 11 PM MST THIS EVENING FOR ZONE 56. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
650 AM EST SAT JAN 11 2014 .SYNOPSIS...AS HIGH PRESSURE MOVES FARTHER OFFSHORE...A VIGOROUS COLD FRONT MOVES ACROSS THE REGION TODAY AND THIS EVENING. HIGH PRESSURE QUICKLY BUILDS BACK INTO THE REGION SUNDAY BEHIND THE COLD FRONT. ANOTHER COLD FRONT APPROACHES FROM THE WEST LATE MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 305 AM SATURDAY... DEEP UPPER TROUGH WAS MOVING EAST ON WATER VAPOR IMAGERY EARLY THIS MORNING TOWARD THE MISSISSIPPI RIVER...AND THIS TROUGH WILL MOVE ACROSS CENTRAL NORTH CAROLINA OVERNIGHT TONIGHT. IN ADVANCE...THE LATEST SURFACE ANALYSIS SHOWED A WEDGE FRONT ESSENTIALLY BISECTING CENTRAL NORTH CAROLINA...WITH TEMPERATURES STILL LINGERING IN THE UPPER 30S IN THE IMMEDIATE TRIAD...TO THE MID 60S TOWARD KCTZ. IN FACT...THE TEMPERATURE AT KRDU WAS IN THE MID 40S WHILE THE TEMPERATURE AT THE NWS OFFICE TO THE EAST ACROSS TOWN WAS NEAR 60. THE WEDGE SHOULD START TO BREAK DOWN IN ADVANCE OF THE COLD FRONT...BUT IT COULD BE A SLOW PROCESS...AND WILL STAY ON THE COOLER SIDE OF GUIDANCE WITH THE HIGH TODAY IN THE TRIAD. FROM U.S. 1 EAST...ANTICIPATE ENOUGH WARM ADVECTION THAT TEMPERATURES SHOULD RISE TO VALUE NEAR 70 TO THE MID 70S...WARMEST FAR SOUTHEAST. WILL NOTE RECORD HIGHS AT KRDU OF 75 AND KFAY OF 79 BOTH SET IN 1930. NOT GOING THAT WARM...AND NONE OF THE GUIDANCE SUGGESTS THAT LEVEL OF WARMTH CURRENTLY. THE WARMTH...THOUGH...WILL HELP IN DEVELOPING SOME INSTABILITY DURING THE LATE MORNING AND AFTERNOON. THE GFS IS MORE UNSTABLE THAN THE RAP...WITH THE FORMER SUGGESTING LIFTED INDICES FALLING TO -2C TO -4C ALONG AND EAST OF U.S. 1 BY THE AFTERNOON...ALONG WITH 700J/KG OF CAPE IN THE LOWEST KM AS A STRONG 700MB SHORTWAVE MOVES INTO THE AREA...AHEAD OF A 110KT 500MB JET AND WINDS OF AT LEAST 65KT AT 850MB. THE RAP ONLY FORECASTS ABOUT 200J/KG OF SURFACE-BASED CAPE...BUT EVEN WITH THE CAPE FORECAST OF THE RAP...AND THE LIMITED MIXING ON THE GFS BUFR SOUNDINGS...THERE COULD EXIST ENOUGH BOUNDARY LAYER INSTABILITY WITH THE STRONG WINDS ALOFT AND 60KT OF 0-3KM SHEAR THAT A STRONGLY FORCED LINE OF SHOWERS...WITH ISOLATED THUNDER...MOVES ACROSS CENTRAL NORTH CAROLINA MAINLY THIS AFTERNOON. THE SPC OUTLOOK CONTINUES TO NOTE A SLIGHT RISK FOR CENTRAL NORTH CAROLINA AND THIS SEEMS REASONABLE...AND WILL CONTINUE THE MENTION OF A DAMAGING WIND THREAT FOR MOST OF CENTRAL NORTH CAROLINA IN THE HWO. AS DRY AND MORE STABLE AIR MOVES WEST TO EAST ACROSS THE AREA...ANY SEVERE THREAT SHOULD DIMINISH BY EARLY EVENING IN THE COASTAL PLAIN. CANNOT COMPLETELY RULE OUT AN ISOLATED TORNADO GIVEN THE 0-3KM HELICITY FORECAST BY THE GFS BETWEEN 100 AND 300M2/S2... WITH SIMILAR VALUES FORECAST BY THE LATEST RAP. IN TERMS OF OTHER ITEMS TO CONSIDER...MANY AREAS OF FOG THIS MORNING ACROSS CENTRAL NORTH CAROLINA BUT VISIBILITIES WERE PRIMARILY ABOVE A HALF-MILE. A FEW POCKETS OF VISIBILITY FROM A HALF-MILE OR LESS. FOR NOW AM NOT PLANNING A DENSE FOG ADVISORY...BUT WILL CONTINUE TO MONITOR THIS. IN ADDITION...AS THE SURFACE GRADIENT TIGHTENS THIS AFTERNOON AHEAD OF THE FRONT...WILL CONTINUE TO ANTICIPATE WITH MIXING GRADIENT WIND GUSTS TO 35MPH. TONIGHT...MORE STABLE AIR MOVES INTO CENTRAL NORTH CAROLINA WITH THE GFS BUFR SOUNDINGS FAIRLY SUBSIDENT BY 06Z. LINGERING SHOWERS...AND A POSSIBLE THUNDERSTORM IN THE COASTAL PLAIN EARLY TONIGHT... DIMINISH WEST-TO-EAST AS PRECIPITABLE WATER VALUES FALL TO AROUND A QUARTER-INCH BY 12Z SUNDAY. THE STRONG UPPER TROUGH WILL BE PUSHING THROUGH CENTRAL NORTH CAROLINA AND EXPECT A FEW MID-LEVEL CLOUDS ASSOCIATED WITH IT...BUT MODELS ARE STRONGLY DRY DURING THE OVERNIGHT HOURS. OVERNIGHT LOWS UPPER 30S IN THE TRIAD TO THE MID 40S TOWARD KCTZ...AROUND 40 IN THE U.S. 1 CORRIDOR. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... AS OF 305 AM SATURDAY... SUNDAY...SUBSIDENCE CONTINUES OVERALL...WITH PRECIPITABLE WATER VALUES FALLING BELOW A QUARTER-INCH SUNDAY UNDER BUILDING HIGH PRESSURE SURFACE AND ALOFT. WITH MIXING...THE GFS BUFR SOUNDINGS SUGGEST A FEW WIND GUSTS TO AROUND 20KT SUNDAY BEFORE WINDS SLACKEN AS THE MID-LEVEL TROUGH PULLS AWAY TO THE EAST AND SURFACE HIGH PRESSURE BUILDS OVERHEAD. HIGHS IN THE MID 50 TO AROUND 60. SUNDAY NIGHT...THE MID-LEVEL RIDGE AXIS MOVES EAST WHICH COULD ALLOW A RETURN OF A FEW HIGH CLOUDS INTO CENTRAL NORTH CAROLINA DURING THE OVERNIGHT HOURS AS THE UPPER FLOW BACKS SOUTHWEST. THE RELATIVELY STRONGER 300MB WINDS REMAIN SOUTHWEST OF CENTRAL NORTH CAROLINA SUNDAY NIGHT THROUGH 12Z MONDAY...THOUGH...SO ANY HIGH CLOUDS THAT MOVE IN SHOULD BE SCATTERED TO POSSIBLY THIN BROKEN AT TIMES. OVERNIGHT LOWS IN THE 30S...COOLEST AND CLOSE TO FREEZING IN SOME OF THE TYPICALLY COOLER LOCATIONS OF THE NORTHEAST PIEDMONT AND THE NORTHERN COASTAL PLAIN. -DJF A SHORTWAVE TROUGH IN PROGRESSIVE FLOW ALOFT WILL AMPLIFY ACROSS THE PLAINS AND MS VALLEY MONDAY...WITH PRECEDING SOUTHWESTERLY FLOW ALOFT YIELDING CONSIDERABLE MID-HIGH CLOUDINESS DOWNSTREAM ACROSS THE CAROLINAS AND MIDDLE ATLANTIC. DESPITE THE INCREASING CLOUDINESS...TEMPERATURES WILL TREND ABOVE AVERAGE BY SOME 8-12 DEGREES...IN RETURN SSW FLOW AROUND PROGRESSIVE SURFACE HIGH PRESSURE IN THE WESTERN ATLANTIC. MODEL DIFFERENCES THAT DEVELOP EARLY IN THE PERIOD - SIMILAR TO THOSE EVIDENT DURING THE PAST SEVERAL MODEL ITERATIONS - CONTINUE TO PLAGUE THE MON NIGHT-TUE TIME FRAME. THAT IS...THE ECMWF AND ASSOCIATED ENSEMBLE MEMBERS FAVOR A SLOWER TROUGH PROGRESSION...WITH MORE SOUTHERN STREAM DOMINANCE...AND CONSEQUENTLY ALLOW FOR MORE APPRECIABLE MOISTURE TRANSPORT FARTHER INLAND THAN A MORE SUPPRESSED/OFFSHORE GFS AND GFS ENSEMBLE MEAN SOLUTION. WILL FOLLOW PREVIOUS FORECAST CONTINUITY AND CONTINUED WPC PREFERENCE TOWARD THE WETTER-FOR CENTRAL-NC ECMWF SOLUTIONS...AND AS SUCH...CARRY A HIGH CHANCE TO LOW LIKELY PROBABILITY OF RAIN MON NIGHT-TUE...WITH PRECIPITATION AMOUNTS IN THE QUARTER TO HALF INCH RANGE. CONTINUED RELATIVELY MILD...WITH TEMPERATURES ABOUT 10 DEGREES ABOVE AVERAGE. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... AS OF 305 AM SATURDAY... MODEL DIFFERENCES CONTINUE INTO THE MEDIUM RANGE/LONG TERM...WITH THE ECMWF AND ASSOCIATED ENSEMBLE MEMBERS ON THE SLOWER AND MORE AMPLIFIED ENVELOPE OF SOLUTIONS REGARDING A TRAILING SHORTWAVE TROUGH AND ASSOCIATED STRONG CLIPPER SURFACER LOW FORECAST TO MIGRATE ACROSS THE UPPER MIDWEST AND LOWER GREAT LAKES...AND SOME DEGREE OF SECONDARY COASTAL CYCLOGENESIS ALONG THE MIDDLE ATLANTIC COAST CENTERED AROUND WED. SINCE THE SHORTWAVE TROUGH IN QUESTION IS AN ELONGATED AXIS OF SHEAR VORTICITY SOUTHWEST OF THE ALEUTIANS...IN A REGION OUTSIDE OF THE DOMAIN OF THE EC AND GFS MODEL DATA AVAILABLE TO RAH...IT IS DIFFICULT TO HAVE A PREFERENCE TOWARD ONE CLUSTER OF SOLUTIONS OVER THE OTHER. BOTH CLUSTERS OF SOLUTIONS ARE RELATIVELY MOISTURE-STARVED THROUGH A DEEP LAYER AT OUR LATITUDE - NOT SURPRISING SINCE THE PRIMARY VORT AND CLIPPER SFC LOW PASS TO OUR NORTH - SO WE WILL ACCORDINGLY MAINTAIN THE FLAVOR OF THE PREVIOUS FORECAST...WITH JUST A SLIGHT CHANCE OF PRECIPITATION CENTERED ON THE DAY WED. THERMAL PROFILES INDEED APPEAR QUITE COLD...PARTICULARLY ABOVE THE BOUNDARY LAYER (IN THE H85-7 LAYER)..CHARACTERISTIC OF STEEP LAPSE RATE ALOFT/MOISTURE-STARVED SYSTEMS. THE NON-SPECIFIC MENTION OF "RAIN OR SNOW" WILL SUFFICE UNTIL A CLEARER MODEL PREFERENCE AND/OR CONSENSUS BECOMES APPARENT. CLEARING IN BRIEF MODIFIED POLAR HIGH PRESSURE WILL FOLLOW FOR THU...IN ADVANCE OF YET ANOTHER SHARPENING TROUGH ALOFT AND APPROACHING MOISTURE-STARVED SURFACE FRONTAL ZONE IN CONTINUED STRONGLY PROGRESSIVE FLOW ALOFT...FOR THE END OF THE WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 650 AM SATURDAY... WIDESPREAD IFR TO VLIFR CONDITIONS CONTINUED OVER CENTRAL NORTH CAROLINA EARLY THIS MORNING WITH RAIN BECOMING MORE SCATTERED FOR A PERIOD AS IT TRANSITIONED TO A MORE SHOWERY CHARACTER. LOW-LEVEL WIND SHEAR REMAINED A CONCERN TOWARD THE TRIAD...WITH WIND SPEEDS STILL FAIRLY LIGHT AND NORTHERLY AT THE SURFACE THERE...VEERING RAPIDLY TO THE SOUTH AROUND 40KT BY 2000FT. IN ADDITION...ELEVATED THUNDERSTORMS WERE MOVING TOWARD THE TRIAD AND HAVE NOTED A TEMPORARY CONDITION WITH THUNDER IN THE KINT AND KGSO TAFS EARLY THIS MORNING. DURING THE REST OF THE DAY...A VIGOROUS COLD FRONT MOVES ACROSS THE AREA WITH A LIKELY BAND OF SHOWERS...AND AT LEAST ISOLATED THUNDERSTORMS. GUSTY WINDS WITH THE BAND ARE POSSIBLE IN THE TRIAD...BUT INSTABILITY INCREASES TO THE EAST...AND IT IS NOTED IN THE FORECASTS FOR KRDU...KFAY...AND KRWI WEST GUSTS TO 40KT DURING THE AFTERNOON WHEN IT IS EXPECTED A STRONGLY-FORCED LINE WILL MOVE ACROSS CENTRAL NORTH CAROLINA. NOTED SIMILAR CONDITIONS IN THE TRIAD WITH THE EXPECTED BAND...JUST SLIGHTLY LESS IN TERMS OF THE SPEED OF THE WESTERLY WIND GUSTS DUE TO LESSER INSTABILITY THERE. RAPID DRYING TAKES PLACE LATE THIS AFTERNOON AND THIS EVENING...WITH CONDITIONS RETURNING TO VFR WEST-TO-EAST ACCOMPANIED BY A NOTICEABLE WEST WIND THAT REMAINS FOR MUCH OF THE NIGHT. WEST-NORTHWEST GUSTS TO AROUND 20KT ARE POSSIBLE WITH MIXING SUNDAY BEFORE WINDS DIMINISH SUNDAY AFTERNOON. FOR MONDAY THROUGH WEDNESDAY...A PERIOD OF SUB-VFR CONDITIONS IS POSSIBLE MONDAY NIGHT INTO EARLY TUESDAY WITH A CHANCE OF LIGHT RAIN. ANOTHER PERIOD OF SUB-VFR CONDITIONS COULD OCCUR LATE TUESDAY NIGHT INTO EARLY WEDNESDAY. LIGHT PRECIPITATION IS POSSIBLE THEN AS WELL. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF/MWS LONG TERM...MWS AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EST SAT JAN 11 2014 .SYNOPSIS...AS HIGH PRESSURE MOVES FARTHER OFFSHORE...A VIGOROUS COLD FRONT MOVES ACROSS THE REGION TODAY AND THIS EVENING. HIGH PRESSURE QUICKLY BUILDS BACK INTO THE REGION SUNDAY BEHIND THE COLD FRONT. ANOTHER COLD FRONT APPROACHES FROM THE WEST LATE MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 305 AM SATURDAY... DEEP UPPER TROUGH WAS MOVING EAST ON WATER VAPOR IMAGERY EARLY THIS MORNING TOWARD THE MISSISSIPPI RIVER...AND THIS TROUGH WILL MOVE ACROSS CENTRAL NORTH CAROLINA OVERNIGHT TONIGHT. IN ADVANCE...THE LATEST SURFACE ANALYSIS SHOWED A WEDGE FRONT ESSENTIALLY BISECTING CENTRAL NORTH CAROLINA...WITH TEMPERATURES STILL LINGERING IN THE UPPER 30S IN THE IMMEDIATE TRIAD...TO THE MID 60S TOWARD KCTZ. IN FACT...THE TEMPERATURE AT KRDU WAS IN THE MID 40S WHILE THE TEMPERATURE AT THE NWS OFFICE TO THE EAST ACROSS TOWN WAS NEAR 60. THE WEDGE SHOULD START TO BREAK DOWN IN ADVANCE OF THE COLD FRONT...BUT IT COULD BE A SLOW PROCESS...AND WILL STAY ON THE COOLER SIDE OF GUIDANCE WITH THE HIGH TODAY IN THE TRIAD. FROM U.S. 1 EAST...ANTICIPATE ENOUGH WARM ADVECTION THAT TEMPERATURES SHOULD RISE TO VALUE NEAR 70 TO THE MID 70S...WARMEST FAR SOUTHEAST. WILL NOTE RECORD HIGHS AT KRDU OF 75 AND KFAY OF 79 BOTH SET IN 1930. NOT GOING THAT WARM...AND NONE OF THE GUIDANCE SUGGESTS THAT LEVEL OF WARMTH CURRENTLY. THE WARMTH...THOUGH...WILL HELP IN DEVELOPING SOME INSTABILITY DURING THE LATE MORNING AND AFTERNOON. THE GFS IS MORE UNSTABLE THAN THE RAP...WITH THE FORMER SUGGESTING LIFTED INDICES FALLING TO -2C TO -4C ALONG AND EAST OF U.S. 1 BY THE AFTERNOON...ALONG WITH 700J/KG OF CAPE IN THE LOWEST KM AS A STRONG 700MB SHORTWAVE MOVES INTO THE AREA...AHEAD OF A 110KT 500MB JET AND WINDS OF AT LEAST 65KT AT 850MB. THE RAP ONLY FORECASTS ABOUT 200J/KG OF SURFACE-BASED CAPE...BUT EVEN WITH THE CAPE FORECAST OF THE RAP...AND THE LIMITED MIXING ON THE GFS BUFR SOUNDINGS...THERE COULD EXIST ENOUGH BOUNDARY LAYER INSTABILITY WITH THE STRONG WINDS ALOFT AND 60KT OF 0-3KM SHEAR THAT A STRONGLY FORCED LINE OF SHOWERS...WITH ISOLATED THUNDER...MOVES ACROSS CENTRAL NORTH CAROLINA MAINLY THIS AFTERNOON. THE SPC OUTLOOK CONTINUES TO NOTE A SLIGHT RISK FOR CENTRAL NORTH CAROLINA AND THIS SEEMS REASONABLE...AND WILL CONTINUE THE MENTION OF A DAMAGING WIND THREAT FOR MOST OF CENTRAL NORTH CAROLINA IN THE HWO. AS DRY AND MORE STABLE AIR MOVES WEST TO EAST ACROSS THE AREA...ANY SEVERE THREAT SHOULD DIMINISH BY EARLY EVENING IN THE COASTAL PLAIN. CANNOT COMPLETELY RULE OUT AN ISOLATED TORNADO GIVEN THE 0-3KM HELICITY FORECAST BY THE GFS BETWEEN 100 AND 300M2/S2... WITH SIMILAR VALUES FORECAST BY THE LATEST RAP. IN TERMS OF OTHER ITEMS TO CONSIDER...MANY AREAS OF FOG THIS MORNING ACROSS CENTRAL NORTH CAROLINA BUT VISIBILITIES WERE PRIMARILY ABOVE A HALF-MILE. A FEW POCKETS OF VISIBILITY FROM A HALF-MILE OR LESS. FOR NOW AM NOT PLANNING A DENSE FOG ADVISORY...BUT WILL CONTINUE TO MONITOR THIS. IN ADDITION...AS THE SURFACE GRADIENT TIGHTENS THIS AFTERNOON AHEAD OF THE FRONT...WILL CONTINUE TO ANTICIPATE WITH MIXING GRADIENT WIND GUSTS TO 35MPH. TONIGHT...MORE STABLE AIR MOVES INTO CENTRAL NORTH CAROLINA WITH THE GFS BUFR SOUNDINGS FAIRLY SUBSIDENT BY 06Z. LINGERING SHOWERS...AND A POSSIBLE THUNDERSTORM IN THE COASTAL PLAIN EARLY TONIGHT... DIMINISH WEST-TO-EAST AS PRECIPITABLE WATER VALUES FALL TO AROUND A QUARTER-INCH BY 12Z SUNDAY. THE STRONG UPPER TROUGH WILL BE PUSHING THROUGH CENTRAL NORTH CAROLINA AND EXPECT A FEW MID-LEVEL CLOUDS ASSOCIATED WITH IT...BUT MODELS ARE STRONGLY DRY DURING THE OVERNIGHT HOURS. OVERNIGHT LOWS UPPER 30S IN THE TRIAD TO THE MID 40S TOWARD KCTZ...AROUND 40 IN THE U.S. 1 CORRIDOR. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... AS OF 305 AM SATURDAY... SUNDAY...SUBSIDENCE CONTINUES OVERALL...WITH PRECIPITABLE WATER VALUES FALLING BELOW A QUARTER-INCH SUNDAY UNDER BUILDING HIGH PRESSURE SURFACE AND ALOFT. WITH MIXING...THE GFS BUFR SOUNDINGS SUGGEST A FEW WIND GUSTS TO AROUND 20KT SUNDAY BEFORE WINDS SLACKEN AS THE MID-LEVEL TROUGH PULLS AWAY TO THE EAST AND SURFACE HIGH PRESSURE BUILDS OVERHEAD. HIGHS IN THE MID 50 TO AROUND 60. SUNDAY NIGHT...THE MID-LEVEL RIDGE AXIS MOVES EAST WHICH COULD ALLOW A RETURN OF A FEW HIGH CLOUDS INTO CENTRAL NORTH CAROLINA DURING THE OVERNIGHT HOURS AS THE UPPER FLOW BACKS SOUTHWEST. THE RELATIVELY STRONGER 300MB WINDS REMAIN SOUTHWEST OF CENTRAL NORTH CAROLINA SUNDAY NIGHT THROUGH 12Z MONDAY...THOUGH...SO ANY HIGH CLOUDS THAT MOVE IN SHOULD BE SCATTERED TO POSSIBLY THIN BROKEN AT TIMES. OVERNIGHT LOWS IN THE 30S...COOLEST AND CLOSE TO FREEZING IN SOME OF THE TYPICALLY COOLER LOCATIONS OF THE NORTHEAST PIEDMONT AND THE NORTHERN COASTAL PLAIN. -DJF A SHORTWAVE TROUGH IN PROGRESSIVE FLOW ALOFT WILL AMPLIFY ACROSS THE PLAINS AND MS VALLEY MONDAY...WITH PRECEDING SOUTHWESTERLY FLOW ALOFT YIELDING CONSIDERABLE MID-HIGH CLOUDINESS DOWNSTREAM ACROSS THE CAROLINAS AND MIDDLE ATLANTIC. DESPITE THE INCREASING CLOUDINESS...TEMPERATURES WILL TREND ABOVE AVERAGE BY SOME 8-12 DEGREES...IN RETURN SSW FLOW AROUND PROGRESSIVE SURFACE HIGH PRESSURE IN THE WESTERN ATLANTIC. MODEL DIFFERENCES THAT DEVELOP EARLY IN THE PERIOD - SIMILAR TO THOSE EVIDENT DURING THE PAST SEVERAL MODEL ITERATIONS - CONTINUE TO PLAGUE THE MON NIGHT-TUE TIME FRAME. THAT IS...THE ECMWF AND ASSOCIATED ENSEMBLE MEMBERS FAVOR A SLOWER TROUGH PROGRESSION...WITH MORE SOUTHERN STREAM DOMINANCE...AND CONSEQUENTLY ALLOW FOR MORE APPRECIABLE MOISTURE TRANSPORT FARTHER INLAND THAN A MORE SUPPRESSED/OFFSHORE GFS AND GFS ENSEMBLE MEAN SOLUTION. WILL FOLLOW PREVIOUS FORECAST CONTINUITY AND CONTINUED WPC PREFERENCE TOWARD THE WETTER-FOR CENTRAL-NC ECMWF SOLUTIONS...AND AS SUCH...CARRY A HIGH CHANCE TO LOW LIKELY PROBABILITY OF RAIN MON NIGHT-TUE...WITH PRECIPITATION AMOUNTS IN THE QUARTER TO HALF INCH RANGE. CONTINUED RELATIVELY MILD...WITH TEMPERATURES ABOUT 10 DEGREES ABOVE AVERAGE. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... AS OF 305 AM SATURDAY... MODEL DIFFERENCES CONTINUE INTO THE MEDIUM RANGE/LONG TERM...WITH THE ECMWF AND ASSOCIATED ENSEMBLE MEMBERS ON THE SLOWER AND MORE AMPLIFIED ENVELOPE OF SOLUTIONS REGARDING A TRAILING SHORTWAVE TROUGH AND ASSOCIATED STRONG CLIPPER SURFACER LOW FORECAST TO MIGRATE ACROSS THE UPPER MIDWEST AND LOWER GREAT LAKES...AND SOME DEGREE OF SECONDARY COASTAL CYCLOGENESIS ALONG THE MIDDLE ATLANTIC COAST CENTERED AROUND WED. SINCE THE SHORTWAVE TROUGH IN QUESTION IS AN ELONGATED AXIS OF SHEAR VORTICITY SOUTHWEST OF THE ALEUTIANS...IN A REGION OUTSIDE OF THE DOMAIN OF THE EC AND GFS MODEL DATA AVAILABLE TO RAH...IT IS DIFFICULT TO HAVE A PREFERENCE TOWARD ONE CLUSTER OF SOLUTIONS OVER THE OTHER. BOTH CLUSTERS OF SOLUTIONS ARE RELATIVELY MOISTURE-STARVED THROUGH A DEEP LAYER AT OUR LATITUDE - NOT SURPRISING SINCE THE PRIMARY VORT AND CLIPPER SFC LOW PASS TO OUR NORTH - SO WE WILL ACCORDINGLY MAINTAIN THE FLAVOR OF THE PREVIOUS FORECAST...WITH JUST A SLIGHT CHANCE OF PRECIPITATION CENTERED ON THE DAY WED. THERMAL PROFILES INDEED APPEAR QUITE COLD...PARTICULARLY ABOVE THE BOUNDARY LAYER (IN THE H85-7 LAYER)..CHARACTERISTIC OF STEEP LAPSE RATE ALOFT/MOISTURE-STARVED SYSTEMS. THE NON-SPECIFIC MENTION OF "RAIN OR SNOW" WILL SUFFICE UNTIL A CLEARER MODEL PREFERENCE AND/OR CONSENSUS BECOMES APPARENT. CLEARING IN BRIEF MODIFIED POLAR HIGH PRESSURE WILL FOLLOW FOR THU...IN ADVANCE OF YET ANOTHER SHARPENING TROUGH ALOFT AND APPROACHING MOISTURE-STARVED SURFACE FRONTAL ZONE IN CONTINUED STRONGLY PROGRESSIVE FLOW ALOFT...FOR THE END OF THE WEEK. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 105 AM SATURDAY... WIDESPREAD IFR TO VLIFR CONDITIONS CONTINUE OVER CENTRAL NORTH CAROLINA EARLY THIS MORNING WITH RAIN BECOMING MORE SCATTERED FOR A PERIOD AS IT TRANSITIONS TO A MORE SHOWERY CHARACTER. LOW-LEVEL WIND SHEAR REMAINS A CONCERN...ALTHOUGH MARGINAL BASED ON THE CRITERIA DUE TO THE GRADUAL VEERING AND INCREASE OF THE WIND SPEED WITH HEIGHT ALOFT. STILL...CONTINUING THE MENTION OF LOW-LEVEL WIND SHEAR THROUGH THE EARLY MORNING HOURS FROM THE TRIAD THROUGH THE TRIANGLE...DEEPER INTO THE WEDGED AIR MASS. DURING SATURDAY...A VIGOROUS COLD FRONT MOVES ACROSS THE AREA WITH A LIKELY BAND OF SHOWERS...AND AT LEAST ISOLATED THUNDERSTORMS. GUSTY WINDS WITH THE BAND ARE POSSIBLE IN THE TRIAD...BUT INSTABILITY INCREASES TO THE EAST...AND IT IS NOTED IN THE FORECASTS FOR KRDU...KFAY...AND KRWI WEST GUSTS TO 40KT DURING THE AFTERNOON WHEN IT IS EXPECTED A STRONGLY-FORCED LINE WILL MOVE ACROSS CENTRAL NORTH CAROLINA. RAPID DRYING TAKES PLACE LATE THIS AFTERNOON AND THIS EVENING...WITH CONDITIONS RETURNING TO VFR WEST-TO-EAST ACCOMPANIED BY A NOTICEABLE WEST WIND THAT REMAINS FOR MUCH OF THE NIGHT. WEST-NORTHWEST GUSTS TO AROUND 20KT ARE POSSIBLE WITH MIXING SUNDAY BEFORE WINDS DIMINISH SUNDAY AFTERNOON. FOR MONDAY THROUGH WEDNESDAY...A PERIOD OF SUB-VFR CONDITIONS IS POSSIBLE MONDAY NIGHT INTO EARLY TUESDAY WITH A CHANCE OF LIGHT RAIN. ANOTHER PERIOD OF SUB-VFR CONDITIONS COULD OCCUR LATE TUESDAY NIGHT INTO EARLY WEDNESDAY. LIGHT PRECIPITATION IS POSSIBLE THEN AS WELL. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF/MWS LONG TERM...MWS AVIATION...DJF
AREA FORECAST DISCUSSION
NWS PORTLAND OR
328 AM PST SAT JAN 11 2014 .SYNOPSIS...OUR STRONGEST STORM SO FAR THIS SEASON IS PUSHING A COLD FRONT ONSHORE INTO WASHINGTON AND OREGON THIS MORNING. EXPECT A PERIOD OF STRONG WINDS AND LOCALLY HEAVY RAIN THIS MORNING AS THE FRONT MOVES THROUGH...THEN MORE GUSTY WINDS AND SQUALLY SHOWERS AS THE PARENT LOW MOVES ONSHORE LATER TODAY. SNOW LEVELS WILL FALL BELOW THE CASCADE PASSES BEHIND THE COLD FRONT...RESULTING IN THE FIRST HEAVY SNOW IN QUITE SOME TIME FOR THE CASCADES. A WARM FRONT WILL FOLLOW WITH MORE RAIN SUNDAY...THEN HIGH PRESSURE WILL BRING A DRYING TREND NEXT WEEK. && .SHORT TERM...AN IMPRESSIVE COMPLEX LOW PRESSURE SYSTEM IS EVIDENT ON INFRARED SATELLITE IMAGERY WITH A CENTER NEAR 48N/135W. AN ASSOCIATED OCCLUDED FRONT WRAPS AROUND THIS SYSTEM AND INTO BRITISH COLUMBIA...WITH A STRONG ATTENDANT COLD FRONT APPROACHING MOVING ONSHORE INTO WESTERN WA AND NEAR ASTORIA THIS MOMENT. THIS COLD FRONT WILL MOVE EAST ACROSS THE DISTRICT THIS MORNING...BRINGING A PERIOD OF LOCALLY HEAVY RAIN AND STRONG WINDS...FOLLOWED BY COLDER AIR AND LOWERING SNOW LEVELS. NOT MUCH RAIN HAS FALLEN IN THE WILLAMETTE VALLEY THUS FAR AS DRY SOUTHERLY FLOW HAS DOMINATED MUCH OF THE NIGHT. THE DRYING PRODUCED BY THE SOUTHERLY FLOW HAS ALLOWED DECENT MIXING OF THE BOUNDARY LAYER DESPITE THE FACT IT IS NIGHT TIME. GUSTS HAVE ALREADY REACHED AS HIGH AS 45 MPH IN THE PORTLAND AREA. THIS WAS ENOUGH TO BRIEFLY KNOCK OUT POWER TO OUR OFFICE HERE IN PARKROSE/NE PORTLAND...AND A FEW OTHER POWER OUTAGES HAVE ALREADY BEEN REPORTED IN THE PORTLAND METRO AREA. THE WINDS HAVE BEEN QUITE A BIT STRONGER ALONG THE COAST AND IN THE COAST RANGE...ALREADY EXCEEDING OUR PREVIOUS STRONGEST WINDS OF THE SEASON FROM OUR STORM BACK IN LATE SEPTEMBER. ASTORIA AIRPORT HAS REPORTED A FEW GUSTS IN EXCESS OF 60 MPH...WITH THE HIGHEST BEING 64 MPH. THE NOAA/NOS WIND SENSOR AT GARIBALDI REPORTED 73 MPH AND AN ODOT WIND SENSOR ON THE MEGLER BRIDGE NEAR ASTORIA HAS REPORTED A PEAK GUST OF 79 MPH SO FAR. THE BIG WINNER IS THE BPA SITE ON NASELLE RIDGE IN PACIFIC COUNTY WA WITH A GUST OF 93 MPH...BUT THIS SITE IS HIGHLY ELEVATED AT 2000 FT AND EXPOSED. THIS COINCIDES NICELY WITH THE 75 KT WINDS SHOWN BY THE KLGX DOPPLER RADAR AT AROUND 2000 FT MSL. THE FIRST PEAK OF WINDS WILL COME JUST AHEAD OF THE FRONT AS IT MOVES ONSHORE EARLY THIS MORNING...WITH GUSTS 40-50 MPH POSSIBLE THROUGHOUT THE INLAND VALLEYS...GUSTS UP TO 65 MPH IN THE COASTAL COMMUNITIES...AND 70-80 MPH BEACHES AND HEADLANDS. EXPECT A BRIEF LULL AFTER THE FRONT MOVES THROUGH AS RAIN STABILIZES THE ATMOSPHERE AND PRESSURE GRADIENTS BRIEFLY SLACKEN. A SECOND SURGE OF WIND WILL COME THIS AFTERNOON AS AN IMPRESSIVE BENT-BACK OCCLUSION FEATURE PUSHES ONSHORE. THE RAP MODEL HAS BEEN DAUNTING WITH 60-70 KT WINDS HOVERING JUST 1500-2500 FT ABOVE THE VALLEY FLOOR AS THIS FEATURE MOVES ONSHORE. THE LATEST RUNS ONLY SEEM TO BE GETTING STRONGER. 00Z/06Z NAM BUFR SOUNDINGS ARE A LITTLE MORE CONSERVATIVE...WITH 55-65 KT WINDS 3000-4000 FT MSL. EITHER WAY THERE WILL BE THE POTENTIAL FOR ISOLATED GUSTS UP TO 60 MPH IN THE INTERIOR LOWLANDS TODAY...ESPECIALLY IN SQUALLY SHOWERS AND ISOLATED THUNDERSTORMS...BUT THESE SHOULD NOT BE WIDESPREAD ENOUGH TO WARRANT A HIGH WIND WARNING. IT WILL BE CLOSE THOUGH...AND CERTAINLY BEARS WATCHING. AT THIS POINT IT SEEMS LIKE A SOLID WIND ADVISORY IS THE BEST WAY TO GO FOR THE INLAND VALLEYS. THE COAST AND COAST RANGE WILL BE A DIFFERENT STORY...AND THAT IS WHY WE HAVE THE HIGH WIND WARNING IN EFFECT THROUGH THIS EVENING. EXPECT GUSTS 55-65 MPH TO IMPACT THE COASTAL COMMUNITIES AS THE LOW AND BENT-BACK OCCLUSION MOVE ONSHORE...ESPECIALLY ON THE NORTH COAST. THE GOOD NEWS IS THAT THIS SYSTEM WILL BE A FAST MOVER. THE INITIAL SHOT OF FOCUSED...HEAVY RAIN WILL PROBABLY BE TO SHORT TO CAUSE HYDRO ISSUES. THE HIGHER TERRAIN WILL SEE A QUICK INCH OF RAIN FROM THE COLD FRONT ITSELF THIS MORNING...WHILE THE VALLEYS GET 0.25-0.50 INCH. BEHIND THE FRONT...COLDER AIR WILL MOVE IN AND DROP THE SNOW LEVELS TO AROUND 3000-3500 FEET. MEANWHILE FLOW WILL TURN WESTERLY... GREAT FOR OROGRAPHICS IN THE CASCADES. THIS WILL RESULT IN A MUCH-NEEDED HEAVY SNOW EVENT IN THE CASCADES...WITH 1 TO 2 FEET OF SNOW FALLING IN THE HIGHER ELEVATIONS THIS WEEKEND. THE SNOW WILL COME WITH A SIGNIFICANT AMOUNT OF WIND...CAUSING BLOWING AND DRIFTING OF SNOW. A WARM FRONT SUNDAY WILL BRING ANOTHER SHOT OF PRECIPITATION SUNDAY. A DECENT MOISTURE PLUME WILL OVERRUN THE EXISTING COLD AIR AS A MILD UPPER LEVEL RIDGE SLOWLY BUILDS NORTHWARD OFF THE WEST COAST. THIS SHOULD RESULT IN ANOTHER SHOT OF RAIN...RANGING FROM ABOUT 0.25-0.50 INCH IN THE VALLEYS TO 1-2 INCHES IN THE HIGHER TERRAIN WITH THE HIGHEST AMOUNTS IN THE NORTH. THE WARM FRONT/BAROCLINIC ZONE WILL SLOWLY PUSH NORTH SUN/MON AS THE UPPER RIDGE BUILDS. THIS SHOULD DRY OUT THE FORECAST AREA FROM SOUTH TO NORTH...BUT STRENGTHENING INVERSIONS SHOULD ALLOW FOG TO QUICKLY DEVELOP IN THE VALLEYS. BY MON NIGHT MOST OF SW WASHINGTON AND NW OREGON SHOULD BE DRY...WITH FOG IN THE VALLEYS AND MILDER CONDITIONS UP ABOVE. WEAGLE .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...MONDAY NIGHT THROUGH FRIDAY...KEPT A SLIGHT CHANCE FOR SOME LINGERING SHOWERS LATE MONDAY ACROSS THE NORTHERN ZONES. AFTER THIS...MODELS ARE IN GOOD AGREEMENT THAT AN UPPER LEVEL RIDGE WILL DEVELOP OVER THE REGION AND DOMINATE THE PATTERN UNTIL NEXT WEEKEND. AS A RESULT...NO PRECIP IS EXPECTED THROUGH FRIDAY EXCEPT FOR PERHAPS A LITTLE LIGHT RAIN IN SW WASHINGTON ZONES EARLY WEDNESDAY IN ASSOCIATION WITH A SHORTWAVE DISTURBANCE PROGGED TO MOVE ACROSS NORTHERN WASHINGTON. OTHERWISE EXPECT DAILY FOG TO DEVELOP ACROSS THE VALLEY LOCATIONS. THE UPPER LEVEL RIDGE WILL AMPLIFY BY THURSDAY AND OFFSHORE FLOW WILL DEVELOP INTO FRIDAY. FORECAST MODELS INDICATE THAT THE NEXT FRONTAL SYSTEM WILL ARRIVE ACROSS THE PACIFIC NORTHWEST FOR NEXT WEEKEND. TEMPERATURES WILL BE NEAR SEASONAL NORMS...WITH HIGHS GENERALLY IN THE UPPER 40S AND LOWS IN THE MID 30S THROUGH THE EXTENDED PERIOD. CULLEN && .AVIATION...FRONT NEAR THE COAST BRINGING RAIN...STRONG WINDS AT THE SURFACE AND ALOFT ALONG WITH MVFR TO IFR CONDITIONS. THE FRONT IS EXPECTED AT THE COAST AROUND 12Z AND A COUPLE OF HOURS LATER FOR THE INLAND TAF LOCATIONS. EXPECT MVFR CONDITIONS WITH THE FRONT...THEN TRENDING TO VFR BEHIND THE FRONT LATER IN THE MORNING. THERE WILL BE PLENTY OF SHOWERS AROUND THROUGH THE REST OF THE DAY INTO THE EVENING. EXPECT PERIODS OF MVFR TO DEVELOP IN SOME OF THESE SHOWERS. THE MOUNTAINS WILL BE OBSCURED THROUGH THE NEXT 24 HOURS. THE BIGGEST IMPACT FROM THIS FRONTAL SYSTEM WILL LIKELY BE VERY GUSTY WINDS AHEAD AND WITH THE FRONT. WIND SHEAR WILL LIKELY BE A CONCERN FOR MANY SITES AS A LOW LEVEL JET OF 60+ KT IS BEING ADVERTISED BY THE FCST MODELS BETWEEN 1500 AND 2000 FT. EXPECT THE GUSTY WINDS TO CONTINUE WELL INTO THE AFTERNOON. KPDX AND APPROACHES...FRONT NEAR THE COAST SHOULD MOVE ACROSS THE TERMINAL AROUND 14Z...WITH RAPID IMPROVEMENT TO VFR MID TO LATE MORNING. EXPECT PLENTY OF SHOWERS AROUND THROUGH THE REMAINDER OF THE DAY...WITH PERIODS OF MVFR DEVELOPING DURING SHOWERS. ALSO...LOOK FOR VERY GUSTY S/SW WINDS TO DEVELOP AFTER MIDNIGHT AND CONTINUE THROUGH MUCH OF THE DAY. PYLE/MH && .MARINE...THE COLD FRONT MOVED THROUGH BUOY 46089 AROUND 09Z...BUT WINDS THERE HAVE BARELY BEEN GALES. CLOSER IN THERE IS GOOD EVIDENCE OF A COASTAL JET WITH NEAR SHORE BUOYS AND BEACH WIND OBSERVATIONS INDICATING STORM FORCE GUSTS AFFECTING THE NORTHERN COASTAL WATERS AND THE COLUMBIA RIVER ENTRANCE. ON THE CENTRAL COASTAL WATERS WINDS ARE WEAKER BUT COULD SEE BRIEF STORM FORCE GUSTS AS THE FRONT MOVES THROUGH. THE FRONT IS EXPECTED TO MOVE ASHORE 4 TO 5 AM. BEHIND THE FRONT WINDS WILL VEER TO THE SOUTHWEST AND EASE. THERE COULD BE A PERIOD OF SUB GALE WINDS. HOWEVER...MODELS HAVE BEEN QUITE CONSISTENT WITH A STRONG TROUGH FOLLOWING THE FRONT MOVING INTO THE WATERS LATER IN THE MORNING FOR ANOTHER ROUND OF GALE TO STORM FORCE WIND GUSTS. ASCAT SATELLITE WINDS FROM THE 06Z PASS MATCHED UP QUITE WELL WITH THE NAM BOUNDARY LEVEL WINDS. WITH INCREASED CONFIDENCE IN THE MODELS HAVE DECIDED TO EXTEND THE STORM WARNING FOR THE NORTHERN WATERS THROUGH THE AFTERNOON...BUT LIKELY IT WILL BE OCCASIONAL GUSTS TO 45 TO 50 KT MAINLY ASSOCIATED WITH RAIN SHOWERS. ALSO HAVE LOWERED THE STORM WARNING TO GALES FOR THE CENTRAL COAST GIVEN THE TRACK THE MODELS ARE TAKING THE TROUGH. THE SEAS WILL BECOME EXTREMELY HAZARDOUS TODAY AND TONIGHT. LATEST GUIDANCE CONTINUES THE TREND OF KEEPING MAX SEAS AROUND 30 FT THIS EVENING. THE WESTERLY SWELL WILL CLIMB ABOVE 20 FT THIS MORNING PEAK NEAR 30 FT THIS EVENING...AND LIKELY DROP BELOW 20 FT SUN AFTERNOON. THIS LOOKS TO BE A DYNAMIC FETCH SITUATION AND THE MODELS MAY BE TOO QUICK TO DECAY THE OFFSHORE SEAS. MODELS ALSO TEND TO BE TOO SLOW BUILDING THE SEAS IN THESE SITUATIONS. WENT A LITTLE HIGHER ON THE MAX SEAS THAN ENP OR GWW AND DECAYED THEM A BIT MORE SLOWLY. UNFORTUNATELY THE CORE OF THE HIGHEST SWELL IS IN A DATA VOID AREA SO THERE IS NO GROUND TRUTH DATA TO PERFORM FURTHER ANALYSIS AGAINST MODEL OUTPUT IN THE OFFSHORE WATERS. SINCE THE MODELS HAVE BEEN QUITE CONSISTENT CONFIDENCE IN FORECAST IS HIGH. BY SUN WINDS AND SEAS WILL BE WINDING DOWN AS HIGH PRES BUILD TO THE SOUTHWEST OF OREGON FOR A CALMER PERIOD THROUGH MID NEXT WEEK. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER STORM WARNING FROM 6 AM THIS MORNING TO 4 AM PST SUNDAY FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES. WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR CENTRAL WILLAMETTE VALLEY-GREATER PORTLAND METRO AREA-LOWER COLUMBIA-SOUTH WILLAMETTE VALLEY. HIGH WIND WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL COAST RANGE OF WESTERN OREGON-CENTRAL OREGON COAST-COAST RANGE OF NORTHWEST OREGON-NORTH OREGON COAST. HIGH SURF WARNING FROM 4 PM THIS AFTERNOON TO 10 AM PST SUNDAY FOR CENTRAL OREGON COAST-NORTH OREGON COAST. WA...WINTER STORM WARNING FROM 6 AM THIS MORNING TO 4 AM PST SUNDAY FOR SOUTH WASHINGTON CASCADES. WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR GREATER VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ COUNTY. HIGH WIND WARNING UNTIL 10 PM PST THIS EVENING FOR SOUTH WASHINGTON COAST-WILLAPA HILLS. HIGH SURF WARNING FROM 4 PM THIS AFTERNOON TO 10 AM PST SUNDAY FOR SOUTH WASHINGTON COAST. PZ...STORM WARNING UNTIL 3 PM PST THIS AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. GALE WARNING UNTIL 3 PM PST THIS AFTERNOON FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 AM PST SUNDAY. && 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 STATE COLLEGE PA
1004 PM EST SUN JAN 12 2014 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT BEFORE SLIDING TO THE EAST COAST MONDAY MORNING. A SOUTHERN STREAM WAVE WILL MOVE OVERHEAD MONDAY NIGHT AS A TROUGH DEEPENS TO THE WEST. GRADUALLY COOLER CONDITIONS WILL BE ENCOUNTERED AS THE WEEK WEARS ON AS THE TROUGH SLIDES TO THE EAST. LIGHT SNOW IS POSSIBLE MID-WEEK AND AGAIN LATE IN THE WEEK AS THE TROUGH IS REINFORCED WITH MORE COLD AIR. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... NORTH/SOUTH SFC HIGH PRESSURE RIDGE WAS LOCATED RIGHT OVER CENTRAL PENN THIS EVENING. EXPECT JUST SOME AREAS OF CIRRUS AND PERHAPS SOME SPOTTY ALTO CU TO STREAM EAST ACROSS NORTHERN PENN FOR THE REST OF THE OVERNIGHT HOURS. GENERALLY CLEAR SKIES WILL OCCUR ACROSS THE SOUTHERN HALF OF THE STATE. WINDS WILL BE LIGHT AND VARIABLE ACROSS THE SUSQ VALLEY AND SURROUNDING LOCATIONS...WHILE A 5-10 KT SOUTHWESTERLY BREEZE WILL OCCUR ACROSS THE NW MTNS AND LAUREL HIGHLANDS. MINS TEMPS WILL MOST LIKELY BE IN THE 20S EVERYWHERE...BUT COULD DIP TO AROUND 20 DEG F IN THE TYPICALLY COLDER RURAL OF CENTRAL AND ERN PENN. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... SRLY FLOW WILL CONTINUE ON MONDAY AND ALLOW TEMPS TO RISE...BUT THE INCREASING CLOUDS FROM A WAVE ROLLING UP FROM THE SW WILL TEMPER THE RISE A BIT. MOISTURE DOES MAKE IT HERE FROM THE GULF BUT THE PWATS ONLY GET TO ABOUT 0.75 INCHES. TROUGH DIGGING IN FROM THE WEST WILL HELP TO DEVELOP IT WHOLE SYSTEM A BIT AS IT SLIDES THROUGH. THE FIRST PRECIP WILL LIKELY START TO FALL IN THE WESTERN COUNTIES VERY LATE IN THE AFTN OR RIGHT AROUND SUNSET. WILL KEEP POPS LOW FOR MOST OF THE DAY...BUT BUMPED THEM TO NEAR 60 IN THE WEST BY 00Z. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... PROGRESSIVE TROUGH OVER CENTRAL U.S. SLIDES EASTWARD MON NIGHT...PICKING UP A WEAK WAVE FROM THE SOUTHERN PLAINS AND PUSHING WARMER TEMPS AND INCREASING MOISTURE INTO PA AHEAD OF IT. 850MB TEMPS RISE ABOVE 0C MON NIGHT AS SW FLOW INCREASES...SO LOWS WILL REMAIN MILD...LIKELY OCCURRING IN THE EVENING BEFORE TEMPS LEVEL OFF OR SLOWLY RISE OVERNIGHT. PRECIP WILL QUICKLY SPREAD IN ON THIS JET AXIS...BRINGING A TENTH TO A QUARTER OF AN INCH OF RAIN...WITH POSS SOME WET SNOW MIXED IN ALONG THE NORTHERN TIER. MILD AIR REMAINS IN PLACE ON TUESDAY AS FLOW REMAINS WESTERLY BEHIND THIS WAVE IN RESPONSE TO THE MAIN TROUGH DIGGING BACK TO THE WEST /OVER THE UPPER PLAINS/ AS ENERGY SLIDES DOWN THE BACK SIDE FROM THE CANADIAN ROCKIES. TUES SHOULD BE A MAINLY DRY DAY...THOUGH FLY IN THE OINTMENT IS POTENTIAL FOR WEAK COASTAL WAVE TO HOLD PRECIP IN EASTERN SECTIONS. ECMWF IS MORE INSISTENT THAN OTHER MODELS...AND STRONG SW FLOW SHOULD KEEP THIS WEAK LOW MOVING ALONG...SO LEANED ON THE DRIER FORECAST. TROUGH ROTATES THROUGH TUE NIGHT INTO WED...WITH ASSOCIATED COLD FRONT USHERING IN COLDER TEMPS AND BRINGING SOME LIGHT SNOW TO THE REGION. TEMPS ON WED MAY REACH HIGHS EARLY IN THE NW...WITH MILDER WEATHER HANGING ON THROUGH MUCH OF THE DAY IN THE SE BEFORE COOLER TEMPS ARRIVE. MODEL SOLUTIONS BEGIN TO SHOW MORE DIVERGENCE FROM THIS POINT ONWARD...BUT GENERALLY POINT TOWARD SIMILAR OVERALL SOLUTIONS. YET ANOTHER SURGE OF COLDER AIR ORGANIZES OVER THE GREAT LAKES SPREADS OVER THE MID ATLANTIC REGION BY NEXT WEEKEND AS BROAD TROUGH REMAINS IN PLACE. SCATTERED SNOW SHOWERS WILL BECOME DAILY OCCURRENCES IN THE HIGHER TERRAIN AS NW FLOW REGIME RETURNS. POTENTIAL FOR ANOTHER BLAST OF EVEN COLDER AIR STILL THERE FOR EARLY NEXT WEEK...BUT LATEST MODELS TRYING MORE VIGOROUSLY TO SHUNT THE COLDEST AIR EASTWARD INTO S CANADA AND NEW ENGLAND...BUT FOR US MAINLY REINFORCING THE COLDER AIR ALREADY IN PLACE. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... SATL LOOP SHOWS STRATOCU ERODING FROM THE SOUTH AND WEST THIS EVENING...AS SFC RIDGE AND LOWERING INVERSION HGTS OVERSPREAD THE AREA. LINEAR EXTRAPOLATION AND LATEST RAP OUTPUT SUGGEST THE LAST OF THE MVFR CIGS MAY HOLD ON AT KBFD AND KUNV UNTIL AROUND 01Z...THEN WIDESPREAD VFR CONDS/LGT WINDS EXPECTED OVERNIGHT. THE ONE EXCEPTION MAY BE THE LOWER SUSQ VALLEY...WHERE A BIT OF FOG IS POSSIBLE ARND DAWN. LATEST SREF AND 18Z NAM SFC RH/S IMPLY SOME FOG POSSIBLE AT KMDT/KLNS BTWN 09Z-13Z. OTHER AREA OF CONCERN WILL BE THE POSSIBILITY OF LLWS AT KBFD. A CORE OF STRONG SWRLY WINDS ALOFT MOVING INTO NW PA...COMBINED WITH RELATIVELY LGT WIND AT THE SFC...WILL LIKELY RESULT IN LLWS CRITERIA AT KBFD BTWN 06Z-15Z BASED ON LATEST MDL SOUNDINGS. ANY POSSIBLE AM FOG SHOULD LIFT ACROSS SE PA BY LATE AM...THEN MDL DATA SUPPORTS A HIGH CONFIDENCE OF WIDESPREAD VFR FLYING CONDS FOR THE DAYLIGHT HRS. AN APPROACHING COLD FRONT WILL SPREAD SHRA INTO THE W MTNS BY EVENING WITH SOME VIS/CIG REDUCTIONS LIKELY AFTER DUSK. OUTLOOK... TUE...AM LOW CIGS POSSIBLE N MTNS. WED...MVFR CIGS/-SHSN LIKELY W MTNS. THU...NO SIG WX EXPECTED. FRI...MVFR CIGS/-SHSN LIKELY W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT/DANGELO NEAR TERM...LAMBERT SHORT TERM...LAMBERT/DANGELO LONG TERM...RXR AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
721 PM EST SUN JAN 12 2014 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT AND CONTINUE TO MOVE TO THE EAST. A SOUTHERN STREAM WAVE WILL MOVE OVERHEAD MONDAY NIGHT AS A TROUGH DEEPENS TO THE WEST. GRADUALLY COOLER CONDITIONS WILL BE ENCOUNTERED AS THE WEEK WEARS ON AS THE TROUGH SLIDES TO THE EAST. LIGHT SNOW IS POSSIBLE MID-WEEK AND AGAIN LATE IN THE WEEK AS THE TROUGH IS REINFORCED WITH MORE COLD AIR. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... EXPECT BKN-OVC STRATO CU DECK TO GRADUALLY ERODE FROM THE SOUTH AND WEST EARLY THIS EVENING AS MILDER AND MUCH DRIER AIR ADVECTS UP THE OHIO RIVER VALLEY AND INTO PENN. LATER TONIGHT...ONLY AREAS OF CIRRUS AND PERHAPS SOME SPOTTY ALTO CU WILL BE STREAMING EAST ACROSS THE COMMONWEALTH. WEST TO WSW SFC WINDS START BACK TO THE SOUTH OVER THE WRN HILLS LATE TONIGHT...AS WINDS GO LIGHT AND VARIABLE ELSEWHERE. MINS WILL MOST LIKELY BE IN THE 20S EVERYWHERE...BUT COULD DIP TO AROUND 20 IN THE THOSE TYPICAL DECOUPLED VALLEYS IN THE EAST. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... SRLY FLOW WILL CONTINUE ON MONDAY AND ALLOW TEMPS TO RISE...BUT THE INCREASING CLOUDS FROM A WAVE ROLLING UP FROM THE SW WILL TEMPER THE RISE A BIT. MOISTURE DOES MAKE IT HERE FROM THE GULF BUT THE PWATS ONLY GET TO ABOUT 0.75 INCHES. TROUGH DIGGING IN FROM THE WEST WILL HELP TO DEVELOP IT WHOLE SYSTEM A BIT AS IT SLIDES THROUGH. THE FIRST PRECIP WILL LIKELY START TO FALL IN THE WESTERN COUNTIES VERY LATE IN THE AFTN OR RIGHT AROUND SUNSET. WILL KEEP POPS LOW FOR MOST OF THE DAY...BUT BUMPED THEM TO NEAR 60 IN THE WEST BY 00Z. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... PROGRESSIVE TROUGH OVER CENTRAL U.S. SLIDES EASTWARD MON NIGHT...PICKING UP A WEAK WAVE FROM THE SOUTHERN PLAINS AND PUSHING WARMER TEMPS AND INCREASING MOISTURE INTO PA AHEAD OF IT. 850MB TEMPS RISE ABOVE 0C MON NIGHT AS SW FLOW INCREASES...SO LOWS WILL REMAIN MILD...LIKELY OCCURRING IN THE EVENING BEFORE TEMPS LEVEL OFF OR SLOWLY RISE OVERNIGHT. PRECIP WILL QUICKLY SPREAD IN ON THIS JET AXIS...BRINGING A TENTH TO A QUARTER OF AN INCH OF RAIN...WITH POSS SOME WET SNOW MIXED IN ALONG THE NORTHERN TIER. MILD AIR REMAINS IN PLACE ON TUESDAY AS FLOW REMAINS WESTERLY BEHIND THIS WAVE IN RESPONSE TO THE MAIN TROUGH DIGGING BACK TO THE WEST /OVER THE UPPER PLAINS/ AS ENERGY SLIDES DOWN THE BACK SIDE FROM THE CANADIAN ROCKIES. TUES SHOULD BE A MAINLY DRY DAY...THOUGH FLY IN THE OINTMENT IS POTENTIAL FOR WEAK COASTAL WAVE TO HOLD PRECIP IN EASTERN SECTIONS. ECMWF IS MORE INSISTENT THAN OTHER MODELS...AND STRONG SW FLOW SHOULD KEEP THIS WEAK LOW MOVING ALONG...SO LEANED ON THE DRIER FORECAST. TROUGH ROTATES THROUGH TUE NIGHT INTO WED...WITH ASSOCIATED COLD FRONT USHERING IN COLDER TEMPS AND BRINGING SOME LIGHT SNOW TO THE REGION. TEMPS ON WED MAY REACH HIGHS EARLY IN THE NW...WITH MILDER WEATHER HANGING ON THROUGH MUCH OF THE DAY IN THE SE BEFORE COOLER TEMPS ARRIVE. MODEL SOLUTIONS BEGIN TO SHOW MORE DIVERGENCE FROM THIS POINT ONWARD...BUT GENERALLY POINT TOWARD SIMILAR OVERALL SOLUTIONS. YET ANOTHER SURGE OF COLDER AIR ORGANIZES OVER THE GREAT LAKES SPREADS OVER THE MID ATLANTIC REGION BY NEXT WEEKEND AS BROAD TROUGH REMAINS IN PLACE. SCATTERED SNOW SHOWERS WILL BECOME DAILY OCCURRENCES IN THE HIGHER TERRAIN AS NW FLOW REGIME RETURNS. POTENTIAL FOR ANOTHER BLAST OF EVEN COLDER AIR STILL THERE FOR EARLY NEXT WEEK...BUT LATEST MODELS TRYING MORE VIGOROUSLY TO SHUNT THE COLDEST AIR EASTWARD INTO S CANADA AND NEW ENGLAND...BUT FOR US MAINLY REINFORCING THE COLDER AIR ALREADY IN PLACE. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... SATL LOOP SHOWS STRATOCU ERODING FROM THE SOUTH AND WEST THIS EVENING...AS SFC RIDGE AND LOWERING INVERSION HGTS OVERSPREAD THE AREA. LINEAR EXTRAPOLATION AND LATEST RAP OUTPUT SUGGEST THE LAST OF THE MVFR CIGS MAY HOLD ON AT KBFD AND KUNV UNTIL AROUND 01Z...THEN WIDESPREAD VFR CONDS/LGT WINDS EXPECTED OVERNIGHT. THE ONE EXCEPTION MAY BE THE LOWER SUSQ VALLEY...WHERE A BIT OF FOG IS POSSIBLE ARND DAWN. LATEST SREF AND 18Z NAM SFC RH/S IMPLY SOME FOG POSSIBLE AT KMDT/KLNS BTWN 09Z-13Z. OTHER AREA OF CONCERN WILL BE THE POSSIBILITY OF LLWS AT KBFD. A CORE OF STRONG SWRLY WINDS ALOFT MOVING INTO NW PA...COMBINED WITH RELATIVELY LGT WIND AT THE SFC...WILL LIKELY RESULT IN LLWS CRITERIA AT KBFD BTWN 06Z-15Z BASED ON LATEST MDL SOUNDINGS. ANY POSSIBLE AM FOG SHOULD LIFT ACROSS SE PA BY LATE AM...THEN MDL DATA SUPPORTS A HIGH CONFIDENCE OF WIDESPREAD VFR FLYING CONDS FOR THE DAYLIGHT HRS. AN APPROACHING COLD FRONT WILL SPREAD SHRA INTO THE W MTNS BY EVENING WITH SOME VIS/CIG REDUCTIONS LIKELY AFTER DUSK. OUTLOOK... TUE...AM LOW CIGS POSSIBLE N MTNS. WED...MVFR CIGS/-SHSN LIKELY W MTNS. THU...NO SIG WX EXPECTED. FRI...MVFR CIGS/-SHSN LIKELY W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...DANGELO LONG TERM...RXR AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
621 AM CST SAT JAN 11 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 339 AM CST SAT JAN 11 2014 MAIN FORECAST ADJUSTMENT FOR TODAY WAS TO INCREASE CLOUD COVER THIS MORNING ALONG AND EAST OF THE JAMES RIVER. AN AREA OF STRATUS ASSOCIATED WITH THE LOW LEVEL COLD AIR ADVECTION PUSH IS MOVING SOUTH INTO THE AREA. PREFER A SOLUTION CLOSER TO THE GEM REGIONAL...HRRR AND RAP...WHICH ALL SEEM TO HAVE A DECENT HANDLE ON THIS CLOUD COVER. SOME DISAGREEMENT ON HOW FAST CLOUDS MOVE OUT OF THE AREA OR DISSIPATE...BUT CONSENSUS IS THAT WE SEE RAPID CLEARING BY EARLY TO MID AFTERNOON. THUS WHILE A GOOD PORTION OF THE MORNING MAY END UP CLOUDY...WE SHOULD STILL SEE SOME SUN OVER THE ENTIRE AREA BY AFTERNOON. ADJUSTED HIGHS UP SOME IN SOUTH CENTRAL SOUTH DAKOTA WHERE MID 40S SEEM LIKELY...AND SOME IN THE DOWNSLOPE AREA EAST OF THE BUFFALO RIDGE...WHERE WE WILL LIKELY HIT OR JUST SURPASS THE FREEZING MARK. OTHERWISE THE GOING HIGHS SEEMED IN GOOD SHAPE. WINDS WILL BE BLUSTERY THIS MORNING INTO EARLY AFTERNOON AS WE MIX INTO A 20 TO 30 KT JET AT 925 MB. THE RESULT SHOULD BE A PERIOD WHERE WINDS GUST 20 TO 30 MPH...STRONGEST ALONG THE MISSOURI RIVER AND OUR FAR EASTERN CWA. THESE WINDS SHOULD THEN BEGIN TO TAPER OFF AS WE GO THROUGH THE AFTERNOON HOURS INTO THE EVENING AS THE CORE OF WINDS ALOFT PUSHES EAST AND THE SURFACE RIDGE AXIS MOVES ACROSS. LOW TEMPERATURES A BIT TRICKY TONIGHT. WE WILL LIKELY SEE A QUICK EVENING DROP IN TEMPERATURES AS WINDS LIGHTEN UP. HOWEVER SOUTHERLY WINDS WILL QUICKLY PICK BACK UP AGAIN BY MID EVENING...ENHANCING MIXING AND CAUSING A WARMING TREND THROUGH THE REST OF THE NIGHT. JUST HOW FAR WE FALL IN THE EVENING IS ALWAYS HARD TO SAY. FOR NOW WILL GO WITH LOW TO MID 20S OVER A MAJORITY OF THE AREA...WITH LOW 30S IN SOUTH CENTRAL SOUTH DAKOTA. BY 12Z...TEMPERATURES WILL HAVE RISEN INTO THE 30 TO 40 DEGREE RANGE. OTHER ISSUE TONIGHT WILL BE STRONG WINDS ALONG AND JUST EAST OF THE BUFFALO RIDGE IN SOUTHWEST MINNESOTA. 925MB WINDS SUGGEST THAT THIS AREA COULD SEE A PERIOD WHERE WINDS GUST AROUND 30 TO 40 MPH...MAINLY FROM AROUND MIDNIGHT TO 5 AM OR SO. THE REST OF US WILL SEE SUSTAINED SOUTHERLY WINDS INCREASE GENERALLY INTO THE 10 TO 20 MPH RANGE. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 339 AM CST SAT JAN 11 2014 IN THE INTERMEDIATE TERM...THE NAM APPEARS TO HAVE SOME ISSUES WITH WAVE PLACEMENT AND TIMING WHEN COMPARED TO THE GLOBAL MODELS. THEREFORE THE ECMWF AND GFS WERE FOLLOWED IN THE SUNDAY THROUGH TUESDAY NIGHT PERIODS. BASICALLY THERE ARE THREE COLD FRONTAL PASSAGES TO MONITOR...SUNDAY NIGHT AND MONDAY NIGHT...AND THE LAST ONE IN THE EXTENDED PERIOD ON WEDNESDAY NIGHT. THE GFS IS ABOUT 6 HOURS FASTER THEN THE ECMWF WITH THE FRONTAL PASSAGES SUNDAY NIGHT AND MONDAY NIGHT...AND FOR THAT MATTER ON THURSDAY NIGHT ALSO. WITH THE GFS USUALLY A BIT FAST...TRENDED MORE WITH THE ECMWF FOR FRONTAL TIMING. INITIALLY...SUNDAY STILL LOOKS LIKE A PLEASANT DAY AS SUBTLE SURFACE TROUGHING MOVES ACROSS THE FORECAST AREA. GIVEN THE 925MB TEMPERATURES OFF OF BOTH THE GFS AND ECMWF...WIDESPREAD 40S FOR HIGHS ARE WARRANTED. THIS GO AROUND...THE WEIGHTED MODEL GUIDANCE LOOKED THE BEST AS IT CAPTURED THE DOWNSLOPE FLOW ON THE EAST SIDE OF THE BUFFALO RIDGE IN SW MN...AND THE STRONGER WARMING OVER AREAS WHICH ARE EITHER FREE OF SNOW COVER OR NEARLY FREE. THE SNOW COVERED AREAS IT KEPT IN THE LOWER 40S WHICH LOOKS VERY REASONABLE AT THIS TIME. THEN THE FIRST OF THE THREE COLD FRONTS COMES DOWN SUNDAY NIGHT WHICH STILL LOOKS TO BE A DRY PASSAGE. LOWS WILL LIKELY RANGE FROM THE MID TEENS ALONG THE HIGHWAY 14 CORRIDOR...TO THE LOWER 20S IN THE MO RIVER VALLEY. 925MB WINDS ARE AVERAGING ABOUT 25 TO 35 KNOTS WHICH SUGGESTS A BREEZY NIGHT OF ABOUT 15 TO 30 MPH AT THE SURFACE. BEHIND THE COLD FRONT...MONDAY WILL BE COOLER BUT STILL ABOVE SEASONAL NORMALS. AGAIN FOLLOWING THE ECMWF TIMING CLOSER THEN THE GFS...A SURFACE TROUGH/WARM FRONT WILL MOVE INTO OUR SOUTHERN AND WESTERN ZONES BY AFTERNOON. AHEAD OF THIS TROUGH...IT IS LIKELY THAT HIGHS WILL NOT REACH 30 IN SW MN. BUT THE WESTERLY FLOW BEHIND THE TROUGH SHOULD GIVE 40 TO 45 DEGREE READINGS IN OUR SOUTH CENTRAL SD ZONES...AS WELL AS ABOUT 40 IN SIOUX CITY. THE NEXT COLD FRONT THEN SWEEPS THROUGH AFTER MONDAY EVENING. THIS FRONT HAS A LITTLE BETTER LIFT WITH IT...MORE WIND OFF THE SURFACE...A STRONG PV SURGE AND SOME BETTER MOISTURE DEPTH. HOWEVER MEASURABLE PRECIPITATION MAY BE TOUGH TO FIND...SO BELIEVE THAT ONLY LOW POPS ARE CURRENTLY WARRANTED NORTH OF SIOUX CITY AND STORM LAKE IOWA. 925MB TO 850MB TEMPERATURES SUGGEST THAT MUCH OF THE PRECIPITATION COULD BE A LIGHT MIX OF RAIN OR SNOW MONDAY EVENING...DEPENDING ON WHICH MODEL ONE BELIEVES. FOR INSTANCE THE FASTER GFS WOULD SUPPORT PRIMARILY SNOW...WHILE THE ECMWF WOULD SUGGEST LIGHT RAIN OTHER THAN IN SW MN. SO FOR NOW THIS FAR OUT... PREFERRED JUST LIGHT RAIN OR SNOW UNTIL THE SYSTEM TIMING SETTLES DOWN A BIT. THEN AFTER MIDNIGHT...ANY PRECIP LEFTOVER WILL BE ALL LIGHT SNOW. CONCERNING TEMPERATURES...THE COLD AIR PUSH IS NOT REAL SEVERE DESPITE THE DEEP PV SURGE...AND THE STRONG WINDS DO KEEP THE ATMOSPHERE FAIRLY MIXED. THEREFORE LOWS WILL BE IN THE 20S EXCEPT IN SW MN AND THE SPENCER IA AREA WHERE TEENS ARE MORE LIKELY. IT WILL BE WINDY...BUT WITH THE GFS AND ECMWF SHOWING 30 TO 40 KNOTS AT 925MB...NOT QUITE CONVINCED THAT IT WILL REACH WIND ADVISORY CRITERIA AT THIS TIME...BUT WILL CERTAINLY PUT AN ADDED CHILL TO THE AIR. ON TUESDAY...ONLY A MINIMAL RISE IN TEMPERATURES IS EXPECTED AS COLD AIR ADVECTION CONTINUES THROUGH THE DAY. HIGHS ONLY 5 TO 10 DEGREES OFF OF THE LOWS ARE LIKELY. WIND SPEEDS MAY JUST NUDGE CLOSE TO ADVISORY CRITERIA PRIMARILY IN THE MO RIVER VALLEY COUNTIES. HOWEVER AS IT WAS MONDAY NIGHT...WOULD LIKE TO SEE A LITTLE STRONGER SPEEDS AT 925MB...AS THEY ACTUALLY RELAX A BIT IN OUR WESTERN ZONES THROUGH THE AFTERNOON. WIND SPEEDS WILL KEEP WIND CHILL VALUES IN THE SINGLE DIGITS AND TEENS...MUCH WARMER THEN SOME PREVIOUS READINGS FROM DAYS GONE PAST...BUT IT WILL BE A CHILLY DAY NONETHELESS. THEN AS MENTIONED ABOVE...THE NEXT STRONG COLD FRONT PLOWS THROUGH WEDNESDAY NIGHT WITH THE STRONGEST WINDS YET. DESPITE THE TIMING DIFFERENCE...IN GENERAL BOTH THE GFS AND ECMWF ARE AVERAGING 45 TO 50 KNOTS AT 925MB LATE WEDNESDAY NIGHT AND THURSDAY...AND THAT WOULD BE CERTAINLY STRONG ENOUGH FOR WIND ADVISORY CRITERIA... POSSIBLY EVEN PUSHING HIGH WIND WARNING IN SOME OF OUR HIGHER TERRAIN AREAS. WILL DEFINITELY CONTINUE TO MENTION THIS IN THE FORTHCOMING HWO. AT THIS TIME...THIS BOUNDARY LOOKS DRY. BUT ONE THING OF NOTE IS THAT THE NEW ECMWF DOES REALLY POUR QUITE A BIT OF COLD AIR INTO OUR FORECAST AREA BY THURSDAY NIGHT AND FRIDAY. FOR EXAMPLE THE ALL BLEND IS GIVING US WIDESPREAD 20S AND 30S FOR HIGHS ON FRIDAY...WHEREAS THE RAW ECMWF HIGHS ARE SHOWING MORE LIKE SINGLE DIGITS ABOVE ZERO AND TEENS. DEFINITELY SOMETHING TO WATCH FOR BUT AT LEAST THE ECMWF HAS FAIRLY LIGHT WINDS IN OUR AREA ON FRIDAY WITH A 1036MB HIGH OVER THE FORECAST AREA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 620 AM CST SAT JAN 11 2014 MAIN AVIATION CONCERN WILL BE LOW END MVFR OR HIGH END IFR STRATUS WORKING ITS WAY SOUTH INTO THE AREA THIS MORNING. CONFIDENCE IS LOWEST AT KSUX...BUT RAP AND HRRR HAVE PRETTY CONSISTENTLY INDICATED STRATUS SHOULD MAKE IT THERE. THUS INTRODUCED THESE CIG REDUCTIONS INTO ALL THREE TAF SITES. EXIT OF THE STRATUS IS A LOW CONFIDENCE FORECAST...BUT BELIEVE WE WILL SEE IT EXIT FROM NORTHWEST TO SOUTHEAST FROM LATE MORNING INTO EARLY AFTERNOON. FUTURE SHIFTS WILL NEED TO MONITOR TRENDS...AS THE EXPECTED TIME OF RETURN TO VFR MAY NEED TO BE ADJUSTED A FEW HOURS EITHER WAY. ONCE THE STRATUS EXITS...EXPECTING VFR CONDITIONS THROUGH THE REMAINDER OF THE PERIOD. LOW LEVEL JET INCREASES TONIGHT CREATING SOME BREEZY CONDITIONS AT THE SURFACE....GENERALLY 10 TO 20 KTS. AREAS ALONG AND JUST EAST OF THE BUFFALO RIDGE COULD SEE GUSTS TO AROUND 35 KTS. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHENARD LONG TERM...MJ AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
833 PM CST SUN JAN 12 2014 .DISCUSSION... SHORTAVE TROUGH MOVING OVERHEAD SE TX WILL BRING LIGHT RAIN TO MOST LOCATIONS TONIGHT. BEST CHANCES FOR RAIN WILL BE NEAR THE COAST. THERE IS A CHANCE FOR ISOLATED THUNDERSTORMS AS WELL. DRIER AIR IN THE LOW LEVELS WILL MOISTEN THROUGH THE NIGHT AND EXPECT THAT CHANCES FOR PATCHY FOG WILL INCREASE AFTER ABOUT 3 IN THE MORNING. THE RAIN AND FOG WILL CLEAR OUT MONDAY AS THE COLD FRONT CURRENTLY OVER THE PAN HANDLE PUSHES THROUGH THE FORECAST AREA. FORECAST UPDATE ISSUED TO DELATE THE START OF THE PATCHY FOG UNTIL LATE TONIGHT. 40 && .PREV DISCUSSION... /ISSUED 552 PM CST SUN JAN 12 2014/ DISCUSSION... 00Z TAF DISCUSSION IN AVIATION. AVIATION... WATER VAPOR IMAGERY SHOWS LEAD SHORTWAVE TROUGH MOVING ACROSS THE AREA WITH RADAR PICKING UP SOME DECENT RETURNS. BOUNDARY LAYER STILL DRY SO MOST PRECIP FALLING IS EVAPORATING BEFORE HITTING GROUND HOWEVER A FEW TERMINALS HAVE BEEN REPORTING -RA. WILL START TAFS WITH VCSH AND BKN/OVC VFR DECKS. MAIN SHORTWAVE TROUGH SHOULD MOVE OVER THE AREA BY 12Z MON AHEAD OF STRONGER LONG WAVE TROUGH OVER THE PLAINS. COLD FRONT SHOULD PUSH THROUGH AREA MON MORNING 12-18Z. VERY GUSTY WINDS BEHIND THE FRONT TOMORROW AFTERNOON. SCENARIO FOR NEXT 24HRS TRENDED CLOSER TO GFS SOLUTION...NAM ON THE DRY SIDE AND WILL BE MONITORING TRENDS IN HRRR FOR AMENDMENTS. KCLL/KUTS/KCXO...WILL HAVE MVFR CIGS AT 08Z WITH TEMPO IFR WITH -RA THROUGH 12Z. FRONT LOOKS TO PUSH THROUGH 12-13Z AND CLEAR CIGS OUT OF THE AREA. GUSTY NW WINDS BEGIN MID/LATE MORNING THROUGH THE AFTERNOON. KIAH/KHOU/KSGR...RAINFALL MAY BE MORE SIGNIFICANT HOUSTON TERMINALS SOUTH TO COAST. HAVE -RA STARTING WITH MVFR CIGS AT 07Z AND TEMPO IFR CIGS WITH RA THAT COULD DROP VSBY. FRONT SHOULD REACH HOUSTON AREA AROUND 15Z CLEARING CIGS. NW WINDS WILL BE GUSTY ESPECIALLY FOR KHOU/KSGR CLOSER TO THE COAST. KLBX/KGLS...COASTAL AREAS MAY BE FIRST TO SEE RAIN STARTING AROUND 06Z WITH MVFR CIGS DEVELOPING. STILL THINK BEST RAIN CHANCES CLOSER TO 12Z SO KEPT TEMPO WITH IFR AND RA. FRONT SHOULD REACH THE COAST 15-18Z AND CLEARING OUT CIGS WITH GUSTY NW WINDS. 39 PREV DISCUSSION... /ISSUED 327 PM CST SUN JAN 12 2014/ DISCUSSION... PARTLY TO MOSTLY CLOUDY SKIES ACROSS SOUTHEAST TEXAS THIS AFTERNOON AS A CIRRUS SHIELD HAS MOVED IN FROM THE SOUTHWEST. THE RADAR HAS ALSO STARTED TO LIGHT UP BUT MOST OF THE PRECIP IS EVAPORATING BEFORE IT HITS THE GROUND. AMDAR SOUNDINGS SUPPORT THIS AS THE ATMOSPHERE IS ALMOST COMPLETELY SATURATED ABOVE 550MB WITH EXTREMELY DRY AIR BELOW. DRY AIR BELOW 550 MB WILL SLOWLY START TO ERODE AS THE AFTERNOON PROGRESSES INTO TONIGHT. BOTH NAM AND GFS FORECAST SOUNDINGS SHOW ENOUGH OF THE DRY AIR GONE BY 6Z MONDAY MORNING OR MIDNIGHT TONIGHT. THE UPPER LEVEL LOW HAS CONTINUED TO PUSH TOWARDS THE NORTHEAST THIS AFTERNOON AHEAD OF THE MAIN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT. THE LOW WILL BEGIN TO SHEAR OUT ALLOWING VORTICITY TO OVERRUN THE AREA MONDAY MORNING. THE JET WITH THE UPPER LEVEL TROUGH DOES TRY TO BUILD SOUTHWARDS MONDAY MORNING WHICH WILL PUT SOUTHEAST TEXAS ON THE EDGE OF THE RRQ. THE PVA... WAA... AND MARGINAL JET STRUCTURE WILL HELP GET STORMS STARTED. MODELS APPEAR TO BRING ENOUGH MOISTURE IN FOR RAIN WITH KCLL BEING ON THE EDGE. NAM FORECAST SOUNDINGS AT KGLS REVEAL PWAT VALUES NEAR 1.50". GFS KGLS FORECAST SOUNDINGS HAVE PWAT VALUES AROUND 1.30". INSTABILITY WILL BE LIMITED BUT WILL BE SUFFICIENT FOR SHOWERS WITH ISOLATED THUNDER. DUE TO THE MENTIONED ABOVE HAVE RAISED POPS WITH THE GREATEST CHANCE FOR RAIN NEAR THE COAST. THE HEAVIEST RAIN WILL ALSO LIKELY OCCUR OVER THE WATERS. THE COLD FRONT WILL NOT BE FAR BEHIND AND MOVE THROUGH THE AREA LATE MONDAY MORNING INTO THE AFTERNOON. AFTER THE RAIN MONDAY MORNING SKIES WILL START TO CLEAR IN THE AFTERNOON LEAVING PLEASANT CONDITIONS IN THE WAKE OF THE FRONT. SOUTHEAST TEXAS WILL SEE ANOTHER REINFORCING COLD FRONT TUESDAY NIGHT. MOISTURE WILL BE LIMITED THOUGH AND NO RAIN IS EXPECTED WITH THIS FRONT. YET ANOTHER REINFORCING FRONT WILL MOVE THROUGH FRIDAY AND MIGHT HAVE ENOUGH MOISTURE TO WORK WITH FOR RAIN. FOR RUNNERS IN THE HOUSTON MARATHON NEXT SUNDAY THE 19TH LOOKS TO BE MOSTLY CLOUDY WITH A CHANCE OF LIGHT RAIN/ DRIZZLE AS OF RIGHT NOW. BE SURE TO STAY TUNED FOR FUTURE UPDATES! 23 MARINE... ONSHORE WINDS WILL PERSIST WITH INCREASING RAIN CHANCES TONIGHT THROUGH MONDAY MORNING AS A DISTURBANCE MOVES ACROSS THE REGION. THERE COULD BE SOME FOG/SEA FOG DEVELOPMENT TOO. RAINS/FOG COME TO AN END AS WINDS SHIFT TO THE NORTHWEST AND NORTH LATE MONDAY MORNING THROUGH MONDAY AFTERNOON WITH THE PASSAGE OF THE NEXT COLD FRONT. BEHIND THE FRONT... CAUTION FLAGS OR ADVISORIES WILL LIKELY BE NEEDED. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA TUESDAY NIGHT...FOLLOWED BY YET ANOTHER COLD FRONT THURSDAY NIGHT THROUGH FRIDAY MORNING. 42 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 53 66 37 69 36 / 50 20 0 0 0 HOUSTON (IAH) 58 69 39 69 39 / 70 40 0 0 0 GALVESTON (GLS) 56 69 45 69 47 / 80 60 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
552 PM CST SUN JAN 12 2014 .DISCUSSION... 00Z TAF DISCUSSION IN AVIATION. && .AVIATION... WATER VAPOR IMAGERY SHOWS LEAD SHORTWAVE TROUGH MOVING ACROSS THE AREA WITH RADAR PICKING UP SOME DECENT RETURNS. BOUNDARY LAYER STILL DRY SO MOST PRECIP FALLING IS EVAPORATING BEFORE HITTING GROUND HOWEVER A FEW TERMINALS HAVE BEEN REPORTING -RA. WILL START TAFS WITH VCSH AND BKN/OVC VFR DECKS. MAIN SHORTWAVE TROUGH SHOULD MOVE OVER THE AREA BY 12Z MON AHEAD OF STRONGER LONG WAVE TROUGH OVER THE PLAINS. COLD FRONT SHOULD PUSH THROUGH AREA MON MORNING 12-18Z. VERY GUSTY WINDS BEHIND THE FRONT TOMORROW AFTERNOON. SCENARIO FOR NEXT 24HRS TRENDED CLOSER TO GFS SOLUTION...NAM ON THE DRY SIDE AND WILL BE MONITORING TRENDS IN HRRR FOR AMENDMENTS. KCLL/KUTS/KCXO...WILL HAVE MVFR CIGS AT 08Z WITH TEMPO IFR WITH -RA THROUGH 12Z. FRONT LOOKS TO PUSH THROUGH 12-13Z AND CLEAR CIGS OUT OF THE AREA. GUSTY NW WINDS BEGIN MID/LATE MORNING THROUGH THE AFTERNOON. KIAH/KHOU/KSGR...RAINFALL MAY BE MORE SIGNIFICANT HOUSTON TERMINALS SOUTH TO COAST. HAVE -RA STARTING WITH MVFR CIGS AT 07Z AND TEMPO IFR CIGS WITH RA THAT COULD DROP VSBY. FRONT SHOULD REACH HOUSTON AREA AROUND 15Z CLEARING CIGS. NW WINDS WILL BE GUSTY ESPECIALLY FOR KHOU/KSGR CLOSER TO THE COAST. KLBX/KGLS...COASTAL AREAS MAY BE FIRST TO SEE RAIN STARTING AROUND 06Z WITH MVFR CIGS DEVELOPING. STILL THINK BEST RAIN CHANCES CLOSER TO 12Z SO KEPT TEMPO WITH IFR AND RA. FRONT SHOULD REACH THE COAST 15-18Z AND CLEARING OUT CIGS WITH GUSTY NW WINDS. 39 && .PREV DISCUSSION... /ISSUED 327 PM CST SUN JAN 12 2014/ DISCUSSION... PARTLY TO MOSTLY CLOUDY SKIES ACROSS SOUTHEAST TEXAS THIS AFTERNOON AS A CIRRUS SHIELD HAS MOVED IN FROM THE SOUTHWEST. THE RADAR HAS ALSO STARTED TO LIGHT UP BUT MOST OF THE PRECIP IS EVAPORATING BEFORE IT HITS THE GROUND. AMDAR SOUNDINGS SUPPORT THIS AS THE ATMOSPHERE IS ALMOST COMPLETELY SATURATED ABOVE 550MB WITH EXTREMELY DRY AIR BELOW. DRY AIR BELOW 550 MB WILL SLOWLY START TO ERODE AS THE AFTERNOON PROGRESSES INTO TONIGHT. BOTH NAM AND GFS FORECAST SOUNDINGS SHOW ENOUGH OF THE DRY AIR GONE BY 6Z MONDAY MORNING OR MIDNIGHT TONIGHT. THE UPPER LEVEL LOW HAS CONTINUED TO PUSH TOWARDS THE NORTHEAST THIS AFTERNOON AHEAD OF THE MAIN UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT. THE LOW WILL BEGIN TO SHEAR OUT ALLOWING VORTICITY TO OVERRUN THE AREA MONDAY MORNING. THE JET WITH THE UPPER LEVEL TROUGH DOES TRY TO BUILD SOUTHWARDS MONDAY MORNING WHICH WILL PUT SOUTHEAST TEXAS ON THE EDGE OF THE RRQ. THE PVA... WAA... AND MARGINAL JET STRUCTURE WILL HELP GET STORMS STARTED. MODELS APPEAR TO BRING ENOUGH MOISTURE IN FOR RAIN WITH KCLL BEING ON THE EDGE. NAM FORECAST SOUNDINGS AT KGLS REVEAL PWAT VALUES NEAR 1.50". GFS KGLS FORECAST SOUNDINGS HAVE PWAT VALUES AROUND 1.30". INSTABILITY WILL BE LIMITED BUT WILL BE SUFFICIENT FOR SHOWERS WITH ISOLATED THUNDER. DUE TO THE MENTIONED ABOVE HAVE RAISED POPS WITH THE GREATEST CHANCE FOR RAIN NEAR THE COAST. THE HEAVIEST RAIN WILL ALSO LIKELY OCCUR OVER THE WATERS. THE COLD FRONT WILL NOT BE FAR BEHIND AND MOVE THROUGH THE AREA LATE MONDAY MORNING INTO THE AFTERNOON. AFTER THE RAIN MONDAY MORNING SKIES WILL START TO CLEAR IN THE AFTERNOON LEAVING PLEASANT CONDITIONS IN THE WAKE OF THE FRONT. SOUTHEAST TEXAS WILL SEE ANOTHER REINFORCING COLD FRONT TUESDAY NIGHT. MOISTURE WILL BE LIMITED THOUGH AND NO RAIN IS EXPECTED WITH THIS FRONT. YET ANOTHER REINFORCING FRONT WILL MOVE THROUGH FRIDAY AND MIGHT HAVE ENOUGH MOISTURE TO WORK WITH FOR RAIN. FOR RUNNERS IN THE HOUSTON MARATHON NEXT SUNDAY THE 19TH LOOKS TO BE MOSTLY CLOUDY WITH A CHANCE OF LIGHT RAIN/ DRIZZLE AS OF RIGHT NOW. BE SURE TO STAY TUNED FOR FUTURE UPDATES! 23 MARINE... ONSHORE WINDS WILL PERSIST WITH INCREASING RAIN CHANCES TONIGHT THROUGH MONDAY MORNING AS A DISTURBANCE MOVES ACROSS THE REGION. THERE COULD BE SOME FOG/SEA FOG DEVELOPMENT TOO. RAINS/FOG COME TO AN END AS WINDS SHIFT TO THE NORTHWEST AND NORTH LATE MONDAY MORNING THROUGH MONDAY AFTERNOON WITH THE PASSAGE OF THE NEXT COLD FRONT. BEHIND THE FRONT... CAUTION FLAGS OR ADVISORIES WILL LIKELY BE NEEDED. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA TUESDAY NIGHT...FOLLOWED BY YET ANOTHER COLD FRONT THURSDAY NIGHT THROUGH FRIDAY MORNING. 42 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 53 66 37 69 36 / 50 20 0 0 0 HOUSTON (IAH) 58 69 39 69 39 / 70 40 0 0 0 GALVESTON (GLS) 56 69 45 69 47 / 80 60 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
852 PM CST SUN JAN 12 2014 .UPDATE... THERE APPEARS TO BE A SIGNIFICANT LACK OF LOW LEVEL MOISTURE ACCOMPANYING THE COLD FRONT AS IT MOVES ACROSS THE FORECAST AREA BETWEEN MIDNIGHT AND 6 AM MONDAY. TRENDS UPSTREAM SHOW WIDESPREAD MID AND HIGH CLOUDS. THERE SHOULD BE SOME EVOLUTION TOWARD DEEPER SATURATION THROUGH THE OVERNIGHT AS DEPICTED BY THE ISENTROPIC CONDENSATION PRESSURE DEFICIT ANALYSIS...IT SHOWS A NARROW BAND OF SATURATION THAT DEVELOPS...BUT IT IS MAINLY UP HIGH. THE NEW NAM HAS NOW COME IN DRY WITH THE FRONTAL PASSAGE AND THE HRRR IS DRY AS WELL...EXCEPT FOR A MINOR CLIPPING OF OUR FAR NORTHWEST COUNTIES WITH SOME VERY LIGHT QPF. AT THIS POINT...I/LL CUT BACK PRETTY HARD ON POPS AND WATCH TRENDS. THE TIMING STILL LOOKS GOOD. TEMPS WILL REMAIN ABOVE FREEZING BUT THE PAVEMENT TEMPERATURES CONTINUE TO BE A PROBLEM. THERE IS STILL ENOUGH COLD IN THAT GROUND TO CAUSE SOME FREEZING IF ANY RAIN FALLS...THEREFORE WILL CONTINUE WITH THE MENTION OF RAIN AND FREEZING RAIN. THIS IS A VERY MINOR EVENT AS QPF NUMBERS ARE ON THE ORDER OF .01 TO .03 MAX. && .AVIATION/06Z TAFS/... WE HAD BEEN EXPECTING A BRIEF PERIOD OF MVFR CIGS WITH THE FRONTAL PASSAGE...BUT LOOKING AT CURRENT TRENDS UPSTREAM AND THE NEW 00Z MODEL DATA...THAT MAY NOT HAPPEN. THE LOW LEVELS ARE LOOKING PRETTY DRY AND WE MAY END UP WITH A BRIEF PERIOD OF CIGS BETWEEN 3500-4500FT...PROBABLY HIGHER. ALSO...THE CHANCE FOR THE RAIN/FREEZING RAIN IS LOOKING SMALLER. THE NEW NAM IS DRY WITH FROPA AND TRENDS UPSTREAM ARE NOT ENCOURAGING FOR ANY PRECIP. IF WE DO SEE ANYTHING IT WILL BE LIKELY JUST BE A COUPLE OF HUNDRETHS. LOOK FOR WINDS TO SHIFT TO WESTERLY IN THE WAKE OF THE FRONT AND BECOME BREEZY BY MID DAY ON MONDAY. && .MARINE... THE SOUTHERLY WINDS HAVE DIMINISHED AS THE PRESSURE PATTERN WEAKENS WITH THE APPROACH OF THE COLD FRONT. WINDS WILL SHIFT TO THE WEST AND INCREASE AGAIN MONDAY MORNING BEHIND THE FRONT. THE SMALL CRAFT ADVISORY REMAINS IN EFFECT. && .PREV DISCUSSION... /ISSUED 335 PM CST SUN JAN 12 2014/ SHORT TERM... TONIGHT AND MONDAY...FORECAST CONFIDENCE MEDIUM STILL EXPECTING A LITTLE LIGHT RAIN AHEAD OF AN APPROACHING COLD FRONT LATE THIS EVENING INTO EARLY MONDAY MORNING. MODELS VARY AS TO THE DEPTH OF SATURATION...WITH THE GFS AND NAM SPITTING OUT A COUPLE HUNDREDTHS OF QPF...WHILE THE ECMWF AND CANADIAN ARE A TRACE TO ABOUT A HUNDREDTH. KEPT A MENTION OF FREEZING RAIN IN THE FORECAST...WITH A LITTLE UNCERTAINTY WITH WHAT WILL HAPPEN AFTER DARK WITH ROAD TEMPS. RIGHT NOW...ROAD SURFACE TEMPS ARE A FEW DEGREES ABOVE FREEZING...BUT SUB- SURFACE TEMPS ARE STILL A COUPLE DEGREES BELOW FREEZING GIVEN TEMPS IN THE UPPER 30S TO AROUND 40 MOST PLACES...AND A DECENT AMOUNT OF SUN POKING THROUGH MUCH OF THE DAY...THINKING ICE POTENTIAL IS ON THE LOW SIDE FOR TONIGHT. PRECIP WILL EXIT THE EAST EARLY MONDAY MORNING...WITH DRY WEATHER THEN EXPECTED THROUGH THE DAY. SHOULD SEE MOSTLY CLOUDY SKIES CONTINUE INTO THE AFTERNOON...AS THE UPPER SHORTWAVE MOVES THROUGH. TEMPS WILL GENERALLY HOLD STEADY IN THE LOW TO MID 30S TOMORROW MORNING...THEN PROBABLY BEGIN TO FALL A BIT THROUGH THE AFTERNOON DUE TO COLD ADVECTION BEHIND THE FRONT. MONDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH MODELS CONTINUE TO TAKE A COMPACT SHORTWAVE TROUGH AND SFC LOW ACROSS SRN WI OR THE WI AND IL BORDER FOR LATE MON NT AND TUE AM. LOW TO MID LEVEL FRONTOGENESIS AND PVA WILL FOCUS THE MOST OVER CENTRAL WI WITH LOW TO MID LEVEL WARM ADVECTION AFFECTING THE ENTIRE AREA. A CONSENSUS OF QPF YIELDS AROUND 0.20 INCHES IN THE FAR NRN CWA TO AROUND 0.10 INCHES NEAR THE IL BORDER. SNOW RATIOS ARE STILL FAIRLY HIGH AND YIELDS SNOW TOTALS OF 3-4 INCHES FROM MQT COUNTY EWD TO SHEBOYGAN COUNTY WITH 1-2 INCHES IN FAR SRN WI. NO WINTER WX ADVISORIES IN EFFECT AT THIS TIME BUT MAY EVENTUALLY BE NEEDED TOWARD CENTRAL WI. BRISK NWLY WINDS AND COLD ADVECTION TO DEVELOP BY TUE AFTERNOON AND LINGER INTO TUE NT. SOME CLEARING SKIES AND THE SOUTHERN EXTENT OF AN ARCTIC AIRMASS WILL MAKE FOR COLD TEMPS WED AM. THE PROGRESSIVE JET STREAM WILL BRING SFC AND UPPER RIDGING INTO WI ON WED. SWLY WINDS AND WARM ADVECTION TO DEVELOP IN THE AFTERNOON. TEMPS T0 REBOUND ONLY INTO THE MID TO UPPER TEENS. LONG TERM... WEDNESDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM THE STRONG LOW PRESSURE AREA THAT WAS DEPICTED TO MOVE ACROSS SRN CANADA FOR WED-FRI IS NOW DIGGING MORE SWD WITH THE LOW TO MOVE ACROSS THE NRN GREAT LAKES THU AND THU NT. SNOW CHANCES HAVE GONE SLIGHTLY UPWARD FROM WED NT THROUGH THU NT WITH WARM ADVECTION SNOW FOLLOWED BY COLD THICKNESS TROUGH SNOW AFTER THE COLD FROPA. WINDY CONDITIONS EXPECTED THROUGH THIS PERIOD. BELOW NORMAL TEMPS FOR FRI-SAT. AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE DAY. MODELS CONTINUE TO SHOW INCREASING SATURATION IN THE LOW LEVELS THIS EVENING AND INTO TONIGHT UNDER SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT. IT LOOKS LIKE CIGS WILL GO BACK DOWN TO AT LEAST MVFR. THE NAM IS THE QUICKEST AND MOST AGGRESSIVE WITH THE SATURATION...INDICATING THE POSSIBILITY OF CIGS LESS THAN 1 KFT. MAY HAVE TO BUMP THE TIMING UP A BIT EARLIER IN TAFS IF CONFIDENCE IN THE EARLIER SOLUTION INCREASES. STILL THINKING THERE COULD BE A LITTLE LIGHT RAIN AS THE FRONT/TROUGH MOVE THROUGH. PAVEMENT HAS WARMED A GOOD DEAL TODAY UNDER THE MILDER TEMPS AND OCCASIONAL SUNSHINE...THOUGH SUB-SURFACE TEMPS REMAIN A BIT BELOW FREEZING. THUS KEPT A MENTION OF FREEZING RAIN IN THE FORECAST...THOUGH THINKING ICE POTENTIAL IS PROBABLY ON THE LOW SIDE FOR TONIGHT. IT SHOULD BE DRY AND BREEZY MONDAY BEHIND THE FRONT...WITH SOME LOWER CIGS POSSIBLY HANGING AROUND UNTIL LATE AFTERNOON AS THE UPPER SHORTWAVE MOVES THROUGH. MARINE... SMALL CRAFT ADVISORY CONTINUES THROUGH TOMORROW AFTERNOON. STILL LOOKS LIKE THERE MAY BE SOMEWHAT OF A LULL IN WINDS TONIGHT...WITH WESTERLY WINDS THEN PICKING UP BEHIND THE COLD FRONT TOMORROW. BASED ON WEBCAMS...SEEMS ICE HAS CONTINUED TO DECREASE. THOUGH THERE HAS NOT BEEN A CLEAR SATELLITE IMAGE IN A COUPLE DAYS...MAY NEED TO REDUCE ICE COVERAGE MORE. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST MONDAY FOR LMZ643>646. && $$ UPDATE...DAVIS TONIGHT/MONDAY AND AVIATION/MARINE...DDV MONDAY NIGHT THROUGH SUNDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
515 PM CST SUN JAN 12 2014 .SHORT TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 322 PM CST SUN JAN 12 2014 THE UPPER MISSISSIPPI RIVER VALLEY REGION WAS ENJOYING THE WARM SECTOR OF A 983MB AREA OF LOW PRESSURE MOVING THROUGH WESTERN ONTARIO. AT 3 PM...TEMPERATURES ACROSS THE AREA RANGED FROM THE MIDDLE 30S ACROSS NORTH CENTRAL WISCONSIN...TO THE UPPER 30S AND EVEN A FEW LOWER 40S ACROSS THE REST OF THE FORECAST AREA. AS THE LOW CONTINUES TO MOVE THROUGH ONTARIO...IT WILL DRAG A COLD FRONT SLOWLY SOUTHEASTWARD ACROSS THE AREA. RAP SHOWING SOME FAIRLY STRONG 700-500MB FRONTOGENESIS AND RIGHT ENTRANCE REGION OF 300MB JET MOVING ACROSS THE AREA THIS EVENING FOR A CHANCE OF RAIN. WITH TEMPERATURES REMAINING IN THE MIDDLE 30S FOR THE MOST PART THROUGH THE EVENING...THREAT OF ANY FREEZING RAIN LOOKS MINIMAL. THE EXCEPTIONS WILL BE LOWER-LYING COLD POCKET AREAS WITH UNTREATED ROADWAYS. THINK THE HIGHEST THREAT AREA FOR THIS HAPPENING WILL BE IN THE CRANBERRY BOG AREAS OF CENTRAL WI WHERE IT TYPICALLY GETS COLDER QUICKER. AS THE SURFACE COLD FRONT CONTINUES TO MOVE THROUGH THE AREA AFTER MIDNIGHT...APPEARS THE CHANCE OF A RAIN/FREEZING SHIFTS MAINLY SOUTHEAST OF A LINE FROM MAUSTON TO BOSCOBEL WI LINE. KEEPING POPS IN THE CHANCE CATEGORY SINCE BUFKIT IS STILL SHOWING SOME SATURATION ISSUES THROUGH THE COLUMN. WILL CONTINUE TO MONITOR THIS SITUATION...BUT NOT THINKING ANY WINTER HEADLINES NEEDED AT THIS TIME. OTHERWISE...LOOK FOR OVERNIGHT LOWS IN THE 25-30 DEGREE RANGE BY 6AM. COLD AIR ADVECTION WILL BE IN PLACE ACROSS THE AREA ON MONDAY ALONG WITH CYCLONIC FLOW ALOFT. THINKING THIS WILL GIVE US A MIXED BAG OF CLOUD COVER WITH STEEPER LAPSE RATE TYPE STRATOCUMULUS AND THEN INCREASING MID CLOUD LATE IN THE AFTERNOON AHEAD LOW PRESSURE AND A WARM FRONT MOVING INTO THE DAKOTAS/WESTERN MN. HIGHS MONDAY EXPECTED TO CLIMB ONLY A COUPLE DEGREES FROM THE OVERNIGHT LOWS...TOPPING OFF IN THE MIDDLE 20S TO THE LOWER 30S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 322 PM CST SUN JAN 12 2014 12.12Z MODELS VERY CONSISTENT IN BRINGING A VIGOROUS MID-LEVEL TROUGH AND SURFACE LOW ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY. MODELS PRETTY MUCH LOCKING ONTO A COMMON SOLUTION...BRINGING THE HEAVIEST SNOW THROUGH THE I-90/94 CORRIDOR AREAS. THE NAM IS THE HIGHEST WITH ITS SNOW AMOUNTS RANGING FROM 2-5 INCHES WHILE THE ECMWF IS INDICATING 1-3 INCHES. THE GFS COMES IN AT 1-4 INCHES. SREF IS RIGHT IN THE MIDDLE WITH 1-4 INCHES. ALSO LOOKS LIKE THERE WILL BE THE POTENTIAL FOR SOME BLOWING SNOW ACROSS THE OPEN PORTIONS OF NORTHEAST IA AND SOUTHEAST MN TUESDAY AFTERNOON AS GUSTY NORTHWEST WINDS SPREAD IN BEHIND THE SURFACE LOW. DUE TO THE GIVEN SNOWFALL AMOUNTS AND WIND/BLOWING SNOW ISSUES...A WINTER WEATHER ADVISORY HEADLINE WILL EVENTUALLY BE NEEDED FOR THIS EVENT AND WILL LIKELY BE HOISTED BY THE MIDSHIFT CREW TONIGHT. OTHERWISE...LOOK FOR TEMPERATURES MONDAY NIGHT IN THE TEENS TO LOWER 20S...THEN CLIMBING THROUGH THE 20S ON TUESDAY. ANOTHER SHOT AT SOME SNOW WILL COME ALONG WEDNESDAY NIGHT AS LIFT INCREASES AHEAD OF A WARM FRONT EXTENDING FROM A VIGOROUS LOW PASSING ACROSS SOUTHERN CANADA. SNOW CHANCES WILL CONTINUE INTO THURSDAY WITH COLDER/UNSTABLE CYCLONIC FLOW ENTERING THE REGION. ANOTHER TROUGH WILL DROP INTO THE REGION THURSDAY NIGHT FOR A CONTINUED CHANCE OF LIGHT SNOW MAINLY EAST OF THE MISSISSIPPI RIVER. EXPECT LOWS WEDNESDAY NIGHT IN THE TEENS WITH HIGHS ON THURSDAY WARMING INTO THE 25 TO 32 DEGREE RANGE. COLDER AIR FILTERING INTO THE AREA THURSDAY NIGHT WILL PRODUCE LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. FRIDAY THROUGH THE WEEKEND LOOKS QUIET WEATHER-WISE AS A MID/UPPER RIDGE OF HIGH PRESSURE BUILDS IN FROM THE PLAINS. LOOK FOR HIGHS STARTING OUT COLD IN THE 10-15 DEGREE RANGE FRIDAY...MODERATING INTO THE 20S SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 515 PM CST SUN JAN 12 2014 SHORTWAVE TROUGH WILL SWEEP ACROSS THE REGION TONIGHT. ATMOSPHERE RELATIVELY DRY AND THE SYSTEM ISN/T BRINGING MUCH MOISTURE WITH IT. LOOKING FOR AN INCREASE IN MID LEVEL CLOUDS...WITH ENOUGH FORCING FOR A LIGHT SN/RA...ALTHOUGH MOSTLY EAST OF THE LOCAL AREA. WILL HANG ONTO -SN/-RA AT KLSE FOR A SHORT PERIOD TONIGHT. A SFC COLD FRONT MOVES IN WITH THE SHORTWAVE...AND RAP/NAM/GFS ALL CONTINUE TO POINT TO LOW CIG DEVELOPMENT /MVFR/ IN THE COLD AIR POST THE FRONT - FOR MON MORNING. CONFIDENCE SHAKY BUT WILL STICK WITH THIS POTENTIAL FOR NOW. A MORE SIGNIFICANT SHORTWAVE WILL SPIN ACROSS THE UPPER MISSISSIPPI RIVER VALLEY MONDAY NIGHT...WITH SNOW AND MVFR/IFR CIGS/VSBYS LIKELY. ACCUMULATIONS OF 1 TO 4 INCHES ARE EXPECTED. WINDS WILL INCREASE LATE MONDAY NIGHT INTO TUE...WHICH COULD LEAD TO SOME BLSN CONCERNS AT KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CST FRI JAN 10 2014 .SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT) ISSUED AT 206 PM CST FRI JAN 10 2014 MAIN CONCERNS IN THE SHORT TERM WILL BE DEALING WITH WINTRY MIX INTO TONIGHT. A WINTER WEATHER ADVISORY IS IN EFFECT UNTIL 6 AM SATURDAY. WATER VAPOR IMAGERY SHOWING A DEEP MID-LEVEL TROUGH MOVING ACROSS CENTRAL CONUS AT THIS TIME. AT THE SURFACE...A TROUGH EXTENDED FROM ALONG THE DAKOTAS/MN BORDER...INTO EASTERN NEBRASKA/KANSAS. THESE FEATURES WERE PRODUCING ISENTROPIC LIFT AND MOISTURE TRANSPORT INTO THE AREA FOR A WINTRY MIX OF PRECIPITATION AT GROUND LEVEL. RADAR SHOWING RETURNS ACROSS THE ENTIRE AREA WITH AREAS OF MAINLY DRIZZLE AND FREEZING DRIZZLE BEING REPORTED. SOME SLEET WAS ALSO SHOWING UP ACROSS PARTS OF NORTHEAST IA. OTHERWISE...TEMPERATURES ACROSS THE AREA RANGED FROM THE MIDDLE 20S ACROSS NORTH CENTRAL WI...TO THE LOWER 30S ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI. LOOK FOR THE MID-LEVEL/SURFACE TROUGH TO MOVE EAST THROUGH THE AREA TONIGHT...WITH MOST OF THE PRECIPITATION CHANGING OVER TO LIGHT SNOW THIS EVENING. THE ONLY EXCEPTION WILL BE ACROSS PORTIONS OF NORTHEAST IA INTO FAR SOUTHWEST AND CENTRAL WI WHERE THERE WILL BE LACK OF ICE ISSUES IN THE COLUMN AND WARMER AIR ALOFT. SO...A MIXTURE OF DRIZZLE...FREEZING DRIZZLE...SLEET AND LIGHT SNOW WILL STILL BE POSSIBLE THERE. WHERE THE SNOW FALLS...GENERALLY ALONG AND NORTHWEST OF A TOMAH/LA CROSSE/OELWEIN LINE...PERHAPS 1/2-1 INCH IS POSSIBLE. OF NOTE IS THE RAP SHOWING LOSS OF ICE IN THE CLOUD AGAIN AFTER MIDNIGHT...HINTING AT THE POSSIBILITY OF MIXING WITH OR CHANGING OVER TO LIGHT FREEZING DRIZZLE OVERNIGHT. WITH THIS IN MIND...WILL KEEP WINTER WEATHER ADVISORY GOING THROUGH 6 AM SATURDAY. OVERNIGHT LOWS ARE EXPECTED TO DIP INTO THE 20S. MAY STILL BE SOME LIGHT SNOW/FLURRY ACTIVITY EARLY ON SATURDAY MORNING...BUT LOOKING FOR ANY LINGERING PRECIPITATION TO SHIFT OFF TO THE EAST BY NOON AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE PLAINS. AREAS WEST OF THE MISSISSIPPI WILL LIKELY SEE A GOOD AMOUNT OF SUNSHINE BY AFTERNOON WITH CLEARING PUSHING EAST OF THE MISSISSIPPI LATER IN THE AFTERNOON. HIGHS ON SATURDAY EXPECTED TO RISE INTO THE UPPER 20S TO LOWER 30S. RIDGE OF HIGH PRESSURE WILL CONTINUE TO MOVE EAST ACROSS THE AREA SATURDAY NIGHT FOR QUIET WEATHER CONDITIONS. WILL SEE SOME INCREASE IN MID/HIGH LEVEL CLOUDS THOUGH AHEAD OF A WARM FRONT PUSHING EAST OUT OF THE NORTHERN/CENTRAL PLAINS. OVERNIGHT LOWS WILL BE IN THE LOWER TO MIDDLE TEENS. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 206 PM CST FRI JAN 10 2014 MILDER PACIFIC ORIGIN AIR WILL PUSH INTO THE AREA ON SUNDAY WITH HIGHS EXPECTED TO TOP OFF IN THE LOWER/MIDDLE 30S. UNFORTUNATELY... INCREASING CLOUD COVER AND SOUTHWEST WINDS IN THE 10 TO 20 MPH RANGE WILL MAKE IT FEEL MORE LIKE THE LOWER/MIDDLE 20S. A COLD FRONT WILL THEN PUSH INTO/THROUGH THE AREA SUNDAY NIGHT. THIS WILL GIVE THE AREA A CHANCE OF A WINTRY MIX WITH A TRICKY THERMAL PROFILE IN PLACE. COLDER AIR UNDERCUTTING RELATIVELY MILDER AIR ALOFT MAY PRODUCE A LIGHT WINTRY MIX OF FREEZING RAIN/SLEET/SNOW AS OVERNIGHT LOWS FALL INTO THE TEENS/LOWER 20S. FORTUNATELY... PRECIPITATION LOOKS VERY LIGHT...BUT ANY FREEZING PRECIPITATION COULD CAUSE HEADACHES. WILL CONTINUE TO TO KEEP A CLOSE EYE ON THIS. COLDER AIR WILL FILTER INTO AREA MONDAY THROUGH TUESDAY AS A DEEP MID-LEVEL TROUGH CARVES OUT OVER THE CENTRAL CONUS. SOME EMBEDDED ENERGY WITHIN THE TROUGH WILL GIVE THE AREA A CHANCE FOR LIGHT SNOW AS WELL. LOOK FOR HIGHS MONDAY AND TUESDAY IN THE 20S WITH LOWS MONDAY NIGHT IN THE UPPER SINGLE DIGITS AND TEENS. ANOTHER SHOT AT SOME LIGHT SNOW LOOKS TO OCCUR WEDNESDAY NIGHT INTO THURSDAY AS WARM AIR ADVECTION TAKES PLACE AHEAD OF LOW PRESSURE MOVING ACROSS SOUTHERN CANADA. SOME LINGERING LIGHT SNOW OF FLURRY CHANCES WILL BE SEEN THURSDAY NIGHT AS THE COLD FRONT FROM THIS LOW PASSES THROUGH. MUCH COLDER AIR IS ON TAP GOING INTO FRIDAY AS ANOTHER MODIFIED SHOT OF ARCTIC AIR MAKES ITS WAY INTO THE AREA. HIGHS ARE EXPECTED TO DROP BACK INTO THE TEENS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1105 PM CST FRI JAN 10 2014 THE -SN/-FZDZ CONTINUED TO SHIFT EAST LATE THIS EVENING...AND WILL LIKELY BE EAST OF KRST AROUND 06Z. TRENDS SUGGEST CLOSER TO 09Z FOR KLSE. CLOUDS WILL BE TRICKY AS THEY CONTINUE TO BOUNCE BETWEEN IFR AND MVFR. SOME SUB 500 FT WOULD ALSO SEEM LIKELY AT KRST. MEANWHILE...LATEST FOG/STRATUS SATELLITE IMAGERY DEPICTS A CLEARING WEDGE BEHIND THE PASSING COLD FRONT. THIS COULD REACH KRST BY 12Z. MORE CLOUDS FOUND ACROSS NORTHERN MN...ROTATING SOUTH/SOUTHEAST POST A LOW OVER SOUTHERN CANADA. RAP/NAM/GFS ALL SUGGEST THAT THE CLOUDS WOULD SLIDE ACROSS THE TAF SITES BY LATE MORNING...EXITING BY MID/LATE AFTERNOON. GOING TO TRY AND TIME A TEMPO GROUP FOR WHEN A BREAK IN THE CIGS IS MORE LIKELY THIS MORNING...ALTHOUGH CONFIDENCE IS SHAKY. PRESSURE GRADIENT WILL TIGHTEN SAT...AND THERE COULD BE SOME GUSTS IN THE AFTERNOON...ESPECIALLY IF THE ANTICIPATED CLEARING OCCURS. ANTICIPATING VFR CONDITIONS SAT NIGHT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR WIZ017-029- 034-041>044-053>055-061. MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ096. IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR IAZ010-011- 029-030. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
342 AM CST MON JAN 13 2014 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT REGIONAL RADAR IMAGERY SHOWS BROAD SWATH OF SHOWERS STRETCHING FROM THE TX/LA COASTAL BORDER UP THROUGH NORTHERN MISSISSIPPI AND INTO WESTERN TENNESSEE THIS MORNING...WELL TO THE WEST OF A COLD FRONT SITUATED FROM CENTRAL MISSOURI DOWN THROUGH FAR NWRN ARKANSAS AND INTO EASTERN OKLAHOMA. THE WESTERN EDGE OF THESE SHOWERS STRETCHES FROM MEMPHIS DOWN TO EL DORADO AND WILL MOST LIKELY CONTINUE TO HOLD THERE FOR THE REMAINDER OF THE MORNING. HOWEVER...WILL LEAVE SOME SLIGHT CHANCE POPS BACK AS FAR NORTHWEST AS THE I-30 AND US-67 CORRIDOR AS THE RAPID REFRESH RUC SHOWS SOME ISOLATED SHOWERS DEVELOPING IN THAT AREA THROUGH ROUGHLY 16Z. THE AFOREMENTIONED COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TODAY. TEMPS SHOULD BREAK THE 60 DEGREE MARK ACROSS MUCH OF SOUTHERN ARKANSAS AHEAD OF THE FRONT TODAY...WITH TEMPERATURES HOLDING STEADY OR FALLING SLIGHTLY FROM MORNING VALUES IN THE NORTHWEST. BEHIND THE FRONT...GUSTY WINDS WILL ONCE AGAIN SPREAD ACROSS THE STATE. WIND SPEEDS SHOULD REMAIN SHORT OF ANY ADVISORY LEVELS...BUT GUSTS UP TO 25 MPH WILL BE NOT BE UNCOMMON ACROSS MAINLY THE HIGHER TERRAIN IN THE NORTH AND WEST. ALOFT...THE UPPER TROUGH SUPPORTING THE SFC FRONT JUST TO THE WEST WILL MOVE OFF TO THE EAST BY THIS EVENING. ANOTHER INCOMING DISTURBANCE WILL DIVE SOUTH FROM THE PLAINS AND TRANSIT THE STATE ON TUESDAY. GUSTY NORTHWEST WINDS WILL BE NOTED ON TUE AS A RESULT. CONTINUED WITH DRY FORECAST ON TUE AS WELL AS THIS DISTURBANCE WILL HAVE VERY LITTLE MOISTURE TO WORK WITH. BUT...WOULD NOT BE SURPRISED TO SEE SOME ISOLD SHOWERS OR PATCHY RAIN IN THE NORTHEAST TUESDAY AFTERNOON. REGARDING TEMPERATURES...THEY WILL NOT TAKE A SIGNIFICANT DIVE BEHIND THE FRONT TODAY OR THE ONE COMING THROUGH TUESDAY AS NEITHER IS USHERING IN AN ARCTIC AIR MASS. RATHER THE TUESDAY FRONT WILL COOL THINGS BACK OFF TO AROUND NORMAL...WITH HIGHS ON WEDNESDAY IN THE UPPER 30S TO UPPER 40S. && .LONG TERM...FRIDAY THROUGH SUNDAY THE EXTENDED PERIOD WILL START WITH A RIDGE OVER THE WESTERN UNITED STATES...AND TROUGHING OVER AREAS EAST OF THE ROCKIES. OVER TIME...THE RIDGE OVER THE WEST WILL BUILD EASTWARD...WITH ANY TROUGHING TOWARD NEW ENGLAND. THE PATTERN WOULD SUGGEST A COLD BEGINNING ON FRIDAY...WITH ARKANSAS IN THE WAKE OF A COLD FRONT AND HIGH PRESSURE BUILDING INTO THE REGION FROM THE PLAINS. TEMPERATURES WILL BE A LITTLE BELOW NORMAL...BUT IT WILL BE NOTHING DRASTIC. IT WILL BE MUCH COLDER TOWARD THE OHIO VALLEY...WITH A GLANCING BLOW LOCALLY. AS THE PERIOD PROGRESSES...THERE SHOULD BE A WARMING TREND. THIS WILL HAPPEN AS THE HIGH SHIFTS TO THE EAST...AND RESULTS IN SOUTHERLY WINDS AROUND HERE. TEMPERATURES WILL FINISH AT OR A LITTLE ABOVE NORMAL ON SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 59 34 54 28 / 10 0 10 10 CAMDEN AR 63 36 62 31 / 20 0 0 0 HARRISON AR 57 34 50 25 / 10 0 10 0 HOT SPRINGS AR 60 35 59 29 / 20 0 10 0 LITTLE ROCK AR 62 35 60 29 / 20 0 10 10 MONTICELLO AR 63 37 62 31 / 30 10 0 10 MOUNT IDA AR 58 35 58 29 / 10 0 10 0 MOUNTAIN HOME AR 56 33 51 26 / 10 0 10 0 NEWPORT AR 60 34 55 28 / 20 0 10 10 PINE BLUFF AR 61 35 60 30 / 20 10 0 10 RUSSELLVILLE AR 60 32 57 28 / 10 0 10 0 SEARCY AR 60 32 55 28 / 20 0 10 10 STUTTGART AR 61 35 57 29 / 20 10 10 10 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...64 / LONG TERM...46
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
943 PM MST SUN JAN 12 2014 .UPDATE... ISSUED AT 940 PM MST SUN JAN 12 2014 AREAL SNOW COVERAGE CONTINUES TO CONSTRICT NORTHWARD THIS EVENING AS NORTHWEST FLOW FOCUS PRECIP ON THE NRN CO MTNS. WARM ADVECTION IN THE 700-500 MB INDICATED BETWEEN MIDNIGHT AND NOON MONDAY WHICH SHOULD HELP MAINTAIN SNOW OVER THE ELKHEAD/PARK/GORE MTNS AND FLATTOPS. THE STEAMBOAT VALLEY MAY STILL SEE SOME LIGHT SNOW...BUT SIGNIFICANT ADDITIONAL ACCUMULATIONS HERE AS WELL AS OVER THE WEST ELK/SAWATCH MTNS AROUND CRESTED BUTTE ARE NO LONGER EXPECTED. THUS...HAVE CANCELLED THE WINTER STORM WARNING FOR THESE AREAS (ZONES 5 AND 12). UPDATED GRIDDED AND WORDED FORECASTS HAVE BEEN SENT. UPDATE ISSUED AT 437 PM MST SUN JAN 12 2014 CONVECTIVE SHOWERS DIMINISHING ACROSS THE SAN JUANS...GRAND MESA AND VALLEY ZONES STILL UNDER WINTER HIGHLIGHTS. LATEST RAP AND HRRR MODELS SUGGEST ACTIVITY WILL CONTINUE TO DIMINISH OVER THE NEXT FEW HOURS. WEB CAMS AND SPOTTER REPORTS ALSO INDICATING ACTIVITY WINDING DOWN IN THESE AREAS. WITH SIGNIFICANT ACCUMULATIONS NO LONGER EXPECTED IN THESE AREAS OVERNIGHT...HAVE WENT AHEAD AND CANCELLED THE WARNINGS AND ADVISORIES. THE NORTHERN AND CENTRAL MOUNTAINS WILL CONTINUE TO INFLUENCED BY STRONG OROGRAPHICS AND SNOW SHOWERS...ALONG WITH WIDESPREAD BLOWING SNOW...SO HIGHLIGHTS IN THESE AREAS WILL BE CONTINUED FOR NOW. && .SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT) ISSUED AT 300 PM MST SUN JAN 12 2014 TROUGH AXIS POSITIONED OVER WRN COLORADO THIS AFTERNOON WILL MOVE DOWNSTREAM THIS EVENING. THE DYNAMICAL PORTION HAS MOVED OUT OF THE FORECAST AREA. THE COMBINATION OF POTENTIAL INSTABILITY AND STRONG OROGRAPHIC ACCOUNTS FOR THE SNOWFALL THIS AFTERNOON. MOUNTAIN WEB CAMS...MOST NOTABLY OVER VAIL PASS...SHOW EXTENDED PERIODS OF NEAR WHITEOUT CONDITIONS WITH SNOW PACKED ROADS. GUSTY WINDS (SOME AS HIGH AS 45 MPH) HAVE ACCOMPANIED THE CONVECTIVE SNOW BANDS THAT HAVE DEVELOPED. THE UNSETTLED ENVIRONMENT MAKES SIGNIFICANT SNOWFALL HIT AND MISS...BUT APPEARS THE HEAVIEST SNOWFALL HAS BEEN OVER THE GORE RANGE...ELK/WEST ELK MOUNTAINS...AND NWRN SAN JUAN MOUNTAINS...BUT NOT SO MUCH FOR THE GRAND MESA. UPSTREAM SHEAR AXIS ON THE BACK SIDE OF THE TROUGH WILL TRANSLATE ACROSS THE WESTERN SLOPE TONIGHT. HIGHER RESOLUTION MODELS...SUCH AS THE NAMDNG5 AND WRF MODELS...INDICATE THAT OCCASIONAL SNOW WILL NOT ABATE UNTIL THE PASSAGE OF THIS SHEAR AXIS (FOR THE ELK AND NWRN SAN JUAN MOUNTAINS). MOIST LAYER IS RELATIVELY SHALLOW...BUT IDEAL ICE CRYSTAL GROWTH REGIME IS AT MOUNTAIN TOP LEVEL...THIS LEADS TO SNOW RATIO VALUES AROUND 20/25 TO 1 AND PERHAPS HIGHER. COMBINED WITH THE GUSTY WINDS...BLOWING AND DRIFTING SNOW A SIGNIFICANT IMPACT ISSUE FOR EXPOSED LOCATIONS AND ABOVE TIMBERLINE. ONCE THE SHEAR AXIS CROSSES THE DIVIDE...SNOW WILL BE ENDING FOR THE ELKS/WEST ELKS AND NWRN SAN JUANS. OROGRAPHIC NORTHWEST FLOW WILL IMPACT THE PARK/GORE RANGES AND FLAT TOP MOUNTAINS THROUGH MONDAY. THE SNOW HAS MOMENTARILY LET UP OVER THE STEAMBOAT VICINITY...BUT BELIEVE SNOW WILL INCREASE LATE THIS AFTERNOON AS THE JET OVER UTAH SHIFTS OVER WRN COLORADO TONIGHT. HIGHER RESOLUTION MODELS STILL SHOW THE HAHNS PEAK TO STEAMBOAT SPRINGS AREAS AS THE BULLSEYE FOR SNOW TOTALS DURING THE NEXT 24 HOURS. OROGRAPHIC SNOW MAY CONTINUE THROUGH MONDAY NIGHT. FOR EASTERN UTAH AND WEST CENTRAL/SOUTHWEST COLORADO...CLEARING TREND OVER THE MOUNTAINS LATE TONIGHT...THEN MOSTLY CLEAR FOR THE REMAINDER OF THE PERIOD. WITH PRESSURE GRADIENT RELAXING...WINDS WILL TAPER OFF AFTER SUNSET TONIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 300 PM MST SUN JAN 12 2014 RESIDUAL MOISTURE REMAINS OVER NW COLORADO INTO TUESDAY. THE 700MB LEVEL REMAINS NEAR SATURATION AND AT AN EFFICIENT -10C. SO SCATTERED SNOW SHOWERS PRODUCING LIGHT ACCUMULATIONS ARE EXPECTED TUESDAY FOR THE PARK/GORE/ELK MTNS. ELSEWHERE NORTHWEST BREEZY WINDS WILL MIX INTO MOST VALLEYS KEEPING DAYTIME TEMPERATURES NEAR SEASONAL NORMS. THEN EXPECT DRY AND MILD WEATHER FOR THE REMAINDER OF THE WEEK. THE RIDGE... THAT HAS BEEN JUST OFF THE WEST COAST FOR OVER A MONTH...SHIFTS INLAND. THE AXIS SHIFTS OVER THE ROCKIES BY NEXT WEEKEND. THIS WILL BRING A STRONG WARMING TREND TO THE MOUNTAIN SLOPES WITH WEAK TO MODERATELY STRONG INVERSIONS FORMING IN THE VALLEYS ESPECIALLY VERNAL CRAIG AND GUNNISON. NO SIGNIFICANT PRECIPITATION EXPECTED FOR THE NEW WEEK. THE LATEST MEDIUM RANGE MODELS INDICATE THE RIDGE MAY BREAK DOWN BY NEXT SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 940 PM MST SUN JAN 12 2014 LOW LEVEL MOISTURE IN PERSISTENT NW FLOW WILL KEEP LOW CLOUDS AND SNOW ACROSS THE NRN CO MTNS THROUGH MONDAY AND MAY PERIODICALLY IMPACT KHDN...KSBS WITH MVFR CIGS/VSBY THROUGH 19Z MON. STRONG WINDS ALOFT WILL CONTINUE ENHANCING MECHANICAL TURBULENCE OVER MTN RIDGES WITH LEE-SIDE WAVES POSSIBLE AS THE ATMOSPHERE BECOMES INCREASINGLY STABLE NEAR MTN TOP LEVEL MONDAY MORNING. LOW CLOUDS AND AREAS OF -SN WITH OCCASIONAL MTN TOP OBSCURATIONS WILL EXTEND SOUTH TO KASE...KEGE AND KTEX TONIGHT. CONDITIONS IMPROVE AROUND KTEX AFTER 10Z TONIGHT AND AROUND KASE/KEGE AFTER 18Z MON. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER STORM WARNING UNTIL 5 PM MST MONDAY COZ004-010-013. UT...NONE. && $$ UPDATE...JAD SHORT TERM...PF LONG TERM...JOE AVIATION...JAD
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
858 AM EST SAT JAN 11 2014 .SYNOPSIS... LOW PRESSURE OVER THE CENTRAL GREAT LAKES REGION WILL MOVE NORTHEAST TO WESTERN QUEBEC THIS EVENING. A COLD FRONT SOUTH FROM THE LOW WILL MOVE EAST ACROSS THE AREA TODAY. SUNDAY...HIGH PRESSURE OVER THE GULF COAST STATES WILL BUILD ACROSS THE AREA. ANOTHER COLD FRONT WILL FOLLOW ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... SECONDARY COLD FRONT OVER INDIANA REGENERATING SHOWERS TO THE WEST AS THE PRIMARY FRONT PUSHES EAST OF YOUNGSTOWN. SOME FOG DEVELOPED IN THE MORE STABLE AIR ON THE BACKSIDE OF THE INITIAL FRONT OVER NORTHWEST OH NEAR TOLEDO. WITH THE APPROACH OF THE SECOND FRONT WE EXPECT THIS TO IMPROVE OVER THE NEXT HOUR. THE SHOWERS WILL OVERSPREAD THE AREA BUT WE AREN`T LOOKING AT SIGNIFICANT AMOUNTS OF PRECIPITATION...PERHAPS A FEW MORE TENTHS OF AN INCH TODAY. WITH THE PASSAGE OF THE FRONT THIS AFTERNOON THROUGH EARLY EVENING WE WILL SEE TEMPERATURES FALL WITH A BRIEF TRANSITION OVER TO SNOW. THE AIR WILL COOL FASTER THAN THE GROUND SO WILL SEE A FAIR AMOUNT OF MELTING BEFORE ANY OF THE SNOW BEGINS TO STICK AND ACCUMULATE...BY WHICH TIME THE MOISTURE WILL BE LIMITED. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AGAIN USED MAINLY NAM TIMING THROUGH THE SHORT TERM BLENDING INTO THE GFS TUESDAY. FOR TONIGHT MODELS SHOW THE UPPER TROF ACROSS THE GREAT LAKE SHIFTING EAST THROUGH THE NIGHT AS A SHORT WAVE RIDGE BUILDS IN. HIGH PRESSURE ACROSS THE GULF COAST STATES WILL ALSO EXTEND NORTH INTO THE OHIO VALLEY. WILL BEGIN WITH CLOUDS ACROSS THE EAST HALF OF THE AREA WHERE THE DEEPEST MOISTURE REMAINS AT 12Z HOWEVER IN THE WEST WILL DROP CLOUDS TO PC IN THE MORNING. FOR THE AFTERNOON WILL DECREASE CLOUDS IN THE EAST AS WELL. NEXT SYSTEM WILL COME MONDAY. LOW PRESSURE WILL MOVE EAST ACROSS ONTARIO MONDAY REACHING JAMES BAY BY EVENING. THE ASSOCIATED COLD FRONT WILL MOVE EAST ACROSS THE AREA DURING THE DAY MONDAY. THE NAM DEVELOPS MOST OF THE PRECIP ACROSS THE EASTERN HALF OF THE AREA AS A SURGE OF MOISTURE MOVING OUT OF THE GULF COAST MERGES WITH THE FRONT MOVING THROUGH THE AREA. THE GFS DOESNT SHOW THIS AS AGGRESSIVELY HOWEVER SO WHILE THE HIGHEST POPS ARE ACROSS THE EAST IN THE AFTERNOON DID BACK OFF LIKELY TO HIGH CHANCE NUMBERS. AFTER A 6 TO 12 HOURS BREAK MODELS BRING A CLIPPER THROUGH THE AREA. THE GFS IS A BIT FASTER AT 12Z TUESDAY WITH THE MOISTURE AND SURFACE LOW SO SPLIT THE DIFFERENCE AND BROUGHT SNOW IN CLOUDS BUT ESSENTIALLY BOTH MODELS WOULD SUGGEST SNOW SOMETIME TUESDAY CONTINUING TUESDAY NIGHT. FAIRLY MILD TEMPS...COOLING OFF MID WEEK. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... SEASONAL TEMPERATURES WEDNESDAY THROUGH FRIDAY. BETTER AGREEMENT ON THE PATH OF LOW PRESSURE FROM WESTERN CANADA STAYING NORTH OF THE GREAT LAKES FOR THURSDAY. RIDGING WEDNESDAY WILL PROVIDE FOR RELATIVELY FAIR WEATHER...ALTHOUGH A FEW LIGHT SNOW SHOWERS MAY LINGER ACROSS NE OH/NW PA TO START. THE WARM FRONT EARLY THURSDAY MORNING DOES NOT HAVE A BIG PUSH OF WARM AIR WITH IT AND WILL MODERATE TEMPS ONLY TO NEAR FREEZING. AT THIS POINT IT LOOKS LIKE PRECIP ARRIVES THURSDAY NIGHT AND LINGERS INTO FRIDAY. AT THIS POINT AN EASTERN U.S. TROUGH WILL HAVE RETURNED TO END THE WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... LOW CONFIDENCE FORECAST CONTINUES. MOST MODEL GUIDANCE WOULD HAVE HAD US ALL IFR/MFR THROUGH THE NIGHT AND INSTEAD MOST LOCATIONS HAVE BEEN MVFR/VFR WITH THE EXCEPTION OF TOL. EARLY MORNING RUNS OF THE HRRR COME IN CLOSEST TO CURRENT REALITY SO HAVE LEANED THAT DIRECTION WITH THE FORECAST. MAIN AREA OF RAIN WILL EXIT EAST DURING THE FIRST PART OF THE MORNING. SCATTERED SHOWERS WILL REMAIN IN ITS WAKE WITH A COLD FRONT CROSSING TOL LATE MORNING...AND ERIE EARLY EVENING. FOG AND LOW STRATUS LURK TO THE WEST ACROSS NW OH AND MI/IND AHEAD OF THE COLD FRONT. HRRR DID NOT REALLY GET THIS IFR PAST THE I-71 CORRIDOR AND CLE/MFD. ALL OTHERS JUST DROP TO MVFR LATER. SLOW IMPROVEMENT OVERNIGHT...BUT REMAINING MVFR OVERCAST THROUGH 12Z SUN. PRECIPITATION CHANCES AFTER 00Z SUN VERY LIMITED AND LEFT OUT OF TAF FORECAST. SOUTHERLY WINDS WILL SHIFT SLIGHTLY TO THE SOUTHWEST AND THEN TO THE WEST LATER. GUSTS WILL DEVELOP OF 20 TO 25 KNOTS...SUBSIDING OVERNIGHT. OUTLOOK...SOME NON VFR MON THRU WED. && .MARINE... SOUTH FLOW SHIFT SOUTHWEST WITH THE PASSAGE OF A COLD FRONT. SOME COLD AIR ADVECTION MAY AID IN ALLOWING WINDS TO MIX DOWN AND YIELD GALE FORCE WINDS FOR THE EASTERN TWO THIRDS OF THE LAKE. WILL CONTINUE THE GALE WARNING THAT WAS PREVIOUSLY ISSUED FOR LATER THIS AFTERNOON AND EVENING. THIS MAY CAUSE SHIFTING/RIDGING/RAFTING OF ICE ON THE LAKE. SOUTHWEST WINDS DIMINISH FOR SUNDAY AS A RIDGE MOVES OVERHEAD. MONDAYS COLD FRONT WILL ONLY SHIFT WINDS FROM THE SOUTH TO THE SOUTHWEST. LOW PRESSURE FROM THE NORTHERN PLAINS TAKES A PATH ACROSS THE MIDWEST AND LOWER GREAT LAKES EITHER TUESDAY OR WEDNESDAY. WINDS WILL FINALLY GO NORTHWEST AFTER THE PASSAGE OF THIS SYSTEM. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...GALE WARNING FROM 4 PM THIS AFTERNOON TO 5 AM EST SUNDAY FOR LEZ061-144>149-164>169. && $$ SYNOPSIS...TK NEAR TERM...JAMISON/TK SHORT TERM...TK LONG TERM...OUDEMAN AVIATION...OUDEMAN MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
653 AM EST SAT JAN 11 2014 .SYNOPSIS... LOW PRESSURE OVER THE CENTRAL GREAT LAKES REGION WILL MOVE NORTHEAST TO WESTERN QUEBEC THIS EVENING. A COLD FRONT SOUTH FROM THE LOW WILL MOVE EAST ACROSS THE AREA TODAY. SUNDAY...HIGH PRESSURE OVER THE GULF COAST STATES WILL BUILD ACROSS THE AREA. ANOTHER COLD FRONT WILL FOLLOW ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE...UDJUSTED POPS BASED ON RADAR. ALSO BROUGHT LIKELY POPS BACK TO THE NORTHWEST FOR A TIME LATE THIS MORNING AS SHOWERS FROM NRN INDIANA GET INTO THE AREA. BOOSTED HIGHS A COUPLE DEGREES AS WELL. ORIGINAL...USED A COMBINATION OF THE NAM AND THE HRRR FOR THE NEAR TERM FROM THE PREDAWN HOURS THROUGH THE DAY. WILL BEGIN WITH CATEGORICAL POPS EVERYWHERE BUT WILL BEGIN TO TAPER ALMOST IMMEDIATELY FROM THE WEST BEHIND THE COLD FRONT. RADAR SHOWING WHAT THE EARLIER HRRR HINTED AT WITH THE FIRST SURGE HAVING EXITED TO THE NORTHEAST AND THE SECOND SURGE OF PRECIP MOVING IN. AND YET ANOTHER WAVE NEAR THE OHIO RIVER. EVENTUALLY THIS MAY ALL BLEND TOGETHER EARLY THIS MORNING WITH THE HEAVIEST RAINFALL ACROSS THE CENTRAL COUNTIES OF THE CWA...WITH THE FOCUS MOVING TO THE EASTERN COUNTIES AROUND/AFTER DAWN. BY 15Z BROUGHT POPS TO CHANCE IN THE FAR WEST. MODELS DO SHOW ANOTHER SURFACE TROF/SHORT WAVE ALOFT ROTATING THROUGH THE AREA THAT COULD BRING A FEW SHOWERS TO THE AREA AGAIN IN THE AFTERNOON. AS FOR TEMPS...EXPECT HIGHS TO BE IN THE MORNING WITH TEMPS FALLING DURING MUCH OF THE DAY. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AGAIN USED MAINLY NAM TIMING THROUGH THE SHORT TERM BLENDING INTO THE GFS TUESDAY. FOR TONIGHT MODELS SHOW THE UPPER TROF ACROSS THE GREAT LAKE SHIFTING EAST THROUGH THE NIGHT AS A SHORT WAVE RIDGE BUILDS IN. HIGH PRESSURE ACROSS THE GULF COAST STATES WILL ALSO EXTEND NORTH INTO THE OHIO VALLEY. WILL BEGIN WITH CLOUDS ACROSS THE EAST HALF OF THE AREA WHERE THE DEEPEST MOISTURE REMAINS AT 12Z HOWEVER IN THE WEST WILL DROP CLOUDS TO PC IN THE MORNING. FOR THE AFTERNOON WILL DECREASE CLOUDS IN THE EAST AS WELL. NEXT SYSTEM WILL COME MONDAY. LOW PRESSURE WILL MOVE EAST ACROSS ONTARIO MONDAY REACHING JAMES BAY BY EVENING. THE ASSOCIATED COLD FRONT WILL MOVE EAST ACROSS THE AREA DURING THE DAY MONDAY. THE NAM DEVELOPS MOST OF THE PRECIP ACROSS THE EASTERN HALF OF THE AREA AS A SURGE OF MOISTURE MOVING OUT OF THE GULF COAST MERGES WITH THE FRONT MOVING THROUGH THE AREA. THE GFS DOESNT SHOW THIS AS AGGRESSIVELY HOWEVER SO WHILE THE HIGHEST POPS ARE ACROSS THE EAST IN THE AFTERNOON DID BACK OFF LIKELY TO HIGH CHANCE NUMBERS. AFTER A 6 TO 12 HOURS BREAK MODELS BRING A CLIPPER THROUGH THE AREA. THE GFS IS A BIT FASTER AT 12Z TUESDAY WITH THE MOISTURE AND SURFACE LOW SO SPLIT THE DIFFERENCE AND BROUGHT SNOW IN CLOUDS BUT ESSENTIALLY BOTH MODELS WOULD SUGGEST SNOW SOMETIME TUESDAY CONTINUING TUESDAY NIGHT. FAIRLY MILD TEMPS...COOLING OFF MID WEEK. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... SEASONAL TEMPERATURES WEDNESDAY THROUGH FRIDAY. BETTER AGREEMENT ON THE PATH OF LOW PRESSURE FROM WESTERN CANADA STAYING NORTH OF THE GREAT LAKES FOR THURSDAY. RIDGING WEDNESDAY WILL PROVIDE FOR RELATIVELY FAIR WEATHER...ALTHOUGH A FEW LIGHT SNOW SHOWERS MAY LINGER ACROSS NE OH/NW PA TO START. THE WARM FRONT EARLY THURSDAY MORNING DOES NOT HAVE A BIG PUSH OF WARM AIR WITH IT AND WILL MODERATE TEMPS ONLY TO NEAR FREEZING. AT THIS POINT IT LOOKS LIKE PRECIP ARRIVES THURSDAY NIGHT AND LINGERS INTO FRIDAY. AT THIS POINT AN EASTERN U.S. TROUGH WILL HAVE RETURNED TO END THE WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... LOW CONFIDENCE FORECAST CONTINUES. MOST MODEL GUIDANCE WOULD HAVE HAD US ALL IFR/MFR THROUGH THE NIGHT AND INSTEAD MOST LOCATIONS HAVE BEEN MVFR/VFR WITH THE EXCEPTION OF TOL. EARLY MORNING RUNS OF THE HRRR COME IN CLOSEST TO CURRENT REALITY SO HAVE LEANED THAT DIRECTION WITH THE FORECAST. MAIN AREA OF RAIN WILL EXIT EAST DURING THE FIRST PART OF THE MORNING. SCATTERED SHOWERS WILL REMAIN IN ITS WAKE WITH A COLD FRONT CROSSING TOL LATE MORNING...AND ERIE EARLY EVENING. FOG AND LOW STRATUS LURK TO THE WEST ACROSS NW OH AND MI/IND AHEAD OF THE COLD FRONT. HRRR DID NOT REALLY GET THIS IFR PAST THE I-71 CORRIDOR AND CLE/MFD. ALL OTHERS JUST DROP TO MVFR LATER. SLOW IMPROVEMENT OVERNIGHT...BUT REMAINING MVFR OVERCAST THROUGH 12Z SUN. PRECIPITATION CHANCES AFTER 00Z SUN VERY LIMITED AND LEFT OUT OF TAF FORECAST. SOUTHERLY WINDS WILL SHIFT SLIGHTLY TO THE SOUTHWEST AND THEN TO THE WEST LATER. GUSTS WILL DEVELOP OF 20 TO 25 KNOTS...SUBSIDING OVERNIGHT. OUTLOOK...SOME NON VFR MON THRU WED. && .MARINE... SOUTH FLOW SHIFT SOUTHWEST WITH THE PASSAGE OF A COLD FRONT. SOME COLD AIR ADVECTION MAY AID IN ALLOWING WINDS TO MIX DOWN AND YIELD GALE FORCE WINDS FOR THE EASTERN TWO THIRDS OF THE LAKE. WILL CONTINUE THE GALE WARNING THAT WAS PREVIOUSLY ISSUED FOR LATER THIS AFTERNOON AND EVENING. THIS MAY CAUSE SHIFTING/RIDGING/RAFTING OF ICE ON THE LAKE. SOUTHWEST WINDS DIMINISH FOR SUNDAY AS A RIDGE MOVES OVERHEAD. MONDAYS COLD FRONT WILL ONLY SHIFT WINDS FROM THE SOUTH TO THE SOUTHWEST. LOW PRESSURE FROM THE NORTHERN PLAINS TAKES A PATH ACROSS THE MIDWEST AND LOWER GREAT LAKES EITHER TUESDAY OR WEDNESDAY. WINDS WILL FINALLY GO NORTHWEST AFTER THE PASSAGE OF THIS SYSTEM. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...GALE WARNING FROM 4 PM THIS AFTERNOON TO 5 AM EST SUNDAY FOR LEZ061-144>149-164>169. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...OUDEMAN AVIATION...OUDEMAN MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
637 AM EST SAT JAN 11 2014 .SYNOPSIS... LOW PRESSURE OVER THE CENTRAL GREAT LAKES REGION WILL MOVE NORTHEAST TO WESTERN QUEBEC THIS EVENING. A COLD FRONT SOUTH FROM THE LOW WILL MOVE EAST ACROSS THE AREA TODAY. SUNDAY...HIGH PRESSURE OVER THE GULF COAST STATES WILL BUILD ACROSS THE AREA. ANOTHER COLD FRONT WILL FOLLOW ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... USED A COMBINATION OF THE NAM AND THE HRRR FOR THE NEAR TERM FROM THE PREDAWN HOURS THROUGH THE DAY. WILL BEGIN WITH CATEGORICAL POPS EVERYWHERE BUT WILL BEGIN TO TAPER ALMOST IMMEDIATELY FROM THE WEST BEHIND THE COLD FRONT. RADAR SHOWING WHAT THE EARLIER HRRR HINTED AT WITH THE FIRST SURGE HAVING EXITED TO THE NORTHEAST AND THE SECOND SURGE OF PRECIP MOVING IN. AND YET ANOTHER WAVE NEAR THE OHIO RIVER. EVENTUALLY THIS MAY ALL BLEND TOGETHER EARLY THIS MORNING WITH THE HEAVIEST RAINFALL ACROSS THE CENTRAL COUNTIES OF THE CWA...WITH THE FOCUS MOVING TO THE EASTERN COUNTIES AROUND/AFTER DAWN. BY 15Z BROUGHT POPS TO CHANCE IN THE FAR WEST. MODELS DO SHOW ANOTHER SURFACE TROF/SHORT WAVE ALOFT ROTATING THROUGH THE AREA THAT COULD BRING A FEW SHOWERS TO THE AREA AGAIN IN THE AFTERNOON. AS FOR TEMPS...EXPECT HIGHS TO BE IN THE MORNING WITH TEMPS FALLING DURING MUCH OF THE DAY. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... AGAIN USED MAINLY NAM TIMING THROUGH THE SHORT TERM BLENDING INTO THE GFS TUESDAY. FOR TONIGHT MODELS SHOW THE UPPER TROF ACROSS THE GREAT LAKE SHIFTING EAST THROUGH THE NIGHT AS A SHORT WAVE RIDGE BUILDS IN. HIGH PRESSURE ACROSS THE GULF COAST STATES WILL ALSO EXTEND NORTH INTO THE OHIO VALLEY. WILL BEGIN WITH CLOUDS ACROSS THE EAST HALF OF THE AREA WHERE THE DEEPEST MOISTURE REMAINS AT 12Z HOWEVER IN THE WEST WILL DROP CLOUDS TO PC IN THE MORNING. FOR THE AFTERNOON WILL DECREASE CLOUDS IN THE EAST AS WELL. NEXT SYSTEM WILL COME MONDAY. LOW PRESSURE WILL MOVE EAST ACROSS ONTARIO MONDAY REACHING JAMES BAY BY EVENING. THE ASSOCIATED COLD FRONT WILL MOVE EAST ACROSS THE AREA DURING THE DAY MONDAY. THE NAM DEVELOPS MOST OF THE PRECIP ACROSS THE EASTERN HALF OF THE AREA AS A SURGE OF MOISTURE MOVING OUT OF THE GULF COAST MERGES WITH THE FRONT MOVING THROUGH THE AREA. THE GFS DOESNT SHOW THIS AS AGGRESSIVELY HOWEVER SO WHILE THE HIGHEST POPS ARE ACROSS THE EAST IN THE AFTERNOON DID BACK OFF LIKELY TO HIGH CHANCE NUMBERS. AFTER A 6 TO 12 HOURS BREAK MODELS BRING A CLIPPER THROUGH THE AREA. THE GFS IS A BIT FASTER AT 12Z TUESDAY WITH THE MOISTURE AND SURFACE LOW SO SPLIT THE DIFFERENCE AND BROUGHT SNOW IN CLOUDS BUT ESSENTIALLY BOTH MODELS WOULD SUGGEST SNOW SOMETIME TUESDAY CONTINUING TUESDAY NIGHT. FAIRLY MILD TEMPS...COOLING OFF MID WEEK. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... SEASONAL TEMPERATURES WEDNESDAY THROUGH FRIDAY. BETTER AGREEMENT ON THE PATH OF LOW PRESSURE FROM WESTERN CANADA STAYING NORTH OF THE GREAT LAKES FOR THURSDAY. RIDGING WEDNESDAY WILL PROVIDE FOR RELATIVELY FAIR WEATHER...ALTHOUGH A FEW LIGHT SNOW SHOWERS MAY LINGER ACROSS NE OH/NW PA TO START. THE WARM FRONT EARLY THURSDAY MORNING DOES NOT HAVE A BIG PUSH OF WARM AIR WITH IT AND WILL MODERATE TEMPS ONLY TO NEAR FREEZING. AT THIS POINT IT LOOKS LIKE PRECIP ARRIVES THURSDAY NIGHT AND LINGERS INTO FRIDAY. AT THIS POINT AN EASTERN U.S. TROUGH WILL HAVE RETURNED TO END THE WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... LOW CONFIDENCE FORECAST CONTINUES. MOST MODEL GUIDANCE WOULD HAVE HAD US ALL IFR/MFR THROUGH THE NIGHT AND INSTEAD MOST LOCATIONS HAVE BEEN MVFR/VFR WITH THE EXCEPTION OF TOL. EARLY MORNING RUNS OF THE HRRR COME IN CLOSEST TO CURRENT REALITY SO HAVE LEANED THAT DIRECTION WITH THE FORECAST. MAIN AREA OF RAIN WILL EXIT EAST DURING THE FIRST PART OF THE MORNING. SCATTERED SHOWERS WILL REMAIN IN ITS WAKE WITH A COLD FRONT CROSSING TOL LATE MORNING...AND ERIE EARLY EVENING. FOG AND LOW STRATUS LURK TO THE WEST ACROSS NW OH AND MI/IND AHEAD OF THE COLD FRONT. HRRR DID NOT REALLY GET THIS IFR PAST THE I-71 CORRIDOR AND CLE/MFD. ALL OTHERS JUST DROP TO MVFR LATER. SLOW IMPROVEMENT OVERNIGHT...BUT REMAINING MVFR OVERCAST THROUGH 12Z SUN. PRECIPITATION CHANCES AFTER 00Z SUN VERY LIMITED AND LEFT OUT OF TAF FORECAST. SOUTHERLY WINDS WILL SHIFT SLIGHTLY TO THE SOUTHWEST AND THEN TO THE WEST LATER. GUSTS WILL DEVELOP OF 20 TO 25 KNOTS...SUBSIDING OVERNIGHT. OUTLOOK...SOME NON VFR MON THRU WED. && .MARINE... SOUTH FLOW SHIFT SOUTHWEST WITH THE PASSAGE OF A COLD FRONT. SOME COLD AIR ADVECTION MAY AID IN ALLOWING WINDS TO MIX DOWN AND YIELD GALE FORCE WINDS FOR THE EASTERN TWO THIRDS OF THE LAKE. WILL CONTINUE THE GALE WARNING THAT WAS PREVIOUSLY ISSUED FOR LATER THIS AFTERNOON AND EVENING. THIS MAY CAUSE SHIFTING/RIDGING/RAFTING OF ICE ON THE LAKE. SOUTHWEST WINDS DIMINISH FOR SUNDAY AS A RIDGE MOVES OVERHEAD. MONDAYS COLD FRONT WILL ONLY SHIFT WINDS FROM THE SOUTH TO THE SOUTHWEST. LOW PRESSURE FROM THE NORTHERN PLAINS TAKES A PATH ACROSS THE MIDWEST AND LOWER GREAT LAKES EITHER TUESDAY OR WEDNESDAY. WINDS WILL FINALLY GO NORTHWEST AFTER THE PASSAGE OF THIS SYSTEM. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...GALE WARNING FROM 4 PM THIS AFTERNOON TO 5 AM EST SUNDAY FOR LEZ061-144>149-164>169. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...OUDEMAN AVIATION...OUDEMAN MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1134 PM CST SUN JAN 12 2014 .DISCUSSION... 06Z TAF DISCUSSION IN AVIATION SECTION. && .AVIATION... BASED ON WATER VAPOR IMAGERY...MAIN SHORTWAVE TROUGH NOW OVER S TX AND SHOULD MOVE OVER SE TX THE NEXT 6 HRS. RADAR SHOWS MOST OF THE RAIN ALONG THE COAST AND THEN EAST OF HOUSTON TERMINALS. MVFR CIGS HAVE BEGUN TO FILL IN ACROSS THE AREA WHICH MAY BE AN HOUR OR TWO SOONER THAN 00Z TAF THINKING. STILL POSSIBLE TO GET SOME IFR CIGS BY MORNING WITH INCREASING MOISTURE AND LIGHT WINDS. WILL KEEP LIGHT RA FOR ALL TAFS. LOOKS LIKE ANY POCKETS OF MODERATE RA WILL REMAIN OFF THE COAST. CIGS SHOULD CLEAR OUT 12Z-18Z NORTH TO SOUTH FROM KCLL TO KGLS. LATEST HRRR RUNS SEEM TO SUPPORT THIS PROGRESSION ALONG WITH THE POSSIBILITY OF IFR CIGS AHEAD OF THE FRONT. GUSTY NW WINDS TOMORROW AFTERNOON WITH CLEAR SKIES. WINDS SHOULD DECOUPLE OVERNIGHT. 39 && .PREV DISCUSSION... /ISSUED 833 PM CST SUN JAN 12 2014/ DISCUSSION... SHORTAVE TROUGH MOVING OVERHEAD SE TX WILL BRING LIGHT RAIN TO MOST LOCATIONS TONIGHT. BEST CHANCES FOR RAIN WILL BE NEAR THE COAST. THERE IS A CHANCE FOR ISOLATED THUNDERSTORMS AS WELL. DRIER AIR IN THE LOW LEVELS WILL MOISTEN THROUGH THE NIGHT AND EXPECT THAT CHANCES FOR PATCHY FOG WILL INCREASE AFTER ABOUT 3 IN THE MORNING. THE RAIN AND FOG WILL CLEAR OUT MONDAY AS THE COLD FRONT CURRENTLY OVER THE PAN HANDLE PUSHES THROUGH THE FORECAST AREA. FORECAST UPDATE ISSUED TO DELATE THE START OF THE PATCHY FOG UNTIL LATE TONIGHT. 40 PREV DISCUSSION... /ISSUED 552 PM CST SUN JAN 12 2014/ DISCUSSION... 00Z TAF DISCUSSION IN AVIATION. AVIATION... WATER VAPOR IMAGERY SHOWS LEAD SHORTWAVE TROUGH MOVING ACROSS THE AREA WITH RADAR PICKING UP SOME DECENT RETURNS. BOUNDARY LAYER STILL DRY SO MOST PRECIP FALLING IS EVAPORATING BEFORE HITTING GROUND HOWEVER A FEW TERMINALS HAVE BEEN REPORTING -RA. WILL START TAFS WITH VCSH AND BKN/OVC VFR DECKS. MAIN SHORTWAVE TROUGH SHOULD MOVE OVER THE AREA BY 12Z MON AHEAD OF STRONGER LONG WAVE TROUGH OVER THE PLAINS. COLD FRONT SHOULD PUSH THROUGH AREA MON MORNING 12-18Z. VERY GUSTY WINDS BEHIND THE FRONT TOMORROW AFTERNOON. SCENARIO FOR NEXT 24HRS TRENDED CLOSER TO GFS SOLUTION...NAM ON THE DRY SIDE AND WILL BE MONITORING TRENDS IN HRRR FOR AMENDMENTS. KCLL/KUTS/KCXO...WILL HAVE MVFR CIGS AT 08Z WITH TEMPO IFR WITH -RA THROUGH 12Z. FRONT LOOKS TO PUSH THROUGH 12-13Z AND CLEAR CIGS OUT OF THE AREA. GUSTY NW WINDS BEGIN MID/LATE MORNING THROUGH THE AFTERNOON. KIAH/KHOU/KSGR...RAINFALL MAY BE MORE SIGNIFICANT HOUSTON TERMINALS SOUTH TO COAST. HAVE -RA STARTING WITH MVFR CIGS AT 07Z AND TEMPO IFR CIGS WITH RA THAT COULD DROP VSBY. FRONT SHOULD REACH HOUSTON AREA AROUND 15Z CLEARING CIGS. NW WINDS WILL BE GUSTY ESPECIALLY FOR KHOU/KSGR CLOSER TO THE COAST. KLBX/KGLS...COASTAL AREAS MAY BE FIRST TO SEE RAIN STARTING AROUND 06Z WITH MVFR CIGS DEVELOPING. STILL THINK BEST RAIN CHANCES CLOSER TO 12Z SO KEPT TEMPO WITH IFR AND RA. FRONT SHOULD REACH THE COAST 15-18Z AND CLEARING OUT CIGS WITH GUSTY NW WINDS. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 53 66 37 69 36 / 50 20 0 0 0 HOUSTON (IAH) 58 69 39 69 39 / 70 40 0 0 0 GALVESTON (GLS) 56 69 45 69 47 / 80 60 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...40 AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CST SUN JAN 12 2014 .SHORT TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 322 PM CST SUN JAN 12 2014 THE UPPER MISSISSIPPI RIVER VALLEY REGION WAS ENJOYING THE WARM SECTOR OF A 983MB AREA OF LOW PRESSURE MOVING THROUGH WESTERN ONTARIO. AT 3 PM...TEMPERATURES ACROSS THE AREA RANGED FROM THE MIDDLE 30S ACROSS NORTH CENTRAL WISCONSIN...TO THE UPPER 30S AND EVEN A FEW LOWER 40S ACROSS THE REST OF THE FORECAST AREA. AS THE LOW CONTINUES TO MOVE THROUGH ONTARIO...IT WILL DRAG A COLD FRONT SLOWLY SOUTHEASTWARD ACROSS THE AREA. RAP SHOWING SOME FAIRLY STRONG 700-500MB FRONTOGENESIS AND RIGHT ENTRANCE REGION OF 300MB JET MOVING ACROSS THE AREA THIS EVENING FOR A CHANCE OF RAIN. WITH TEMPERATURES REMAINING IN THE MIDDLE 30S FOR THE MOST PART THROUGH THE EVENING...THREAT OF ANY FREEZING RAIN LOOKS MINIMAL. THE EXCEPTIONS WILL BE LOWER-LYING COLD POCKET AREAS WITH UNTREATED ROADWAYS. THINK THE HIGHEST THREAT AREA FOR THIS HAPPENING WILL BE IN THE CRANBERRY BOG AREAS OF CENTRAL WI WHERE IT TYPICALLY GETS COLDER QUICKER. AS THE SURFACE COLD FRONT CONTINUES TO MOVE THROUGH THE AREA AFTER MIDNIGHT...APPEARS THE CHANCE OF A RAIN/FREEZING SHIFTS MAINLY SOUTHEAST OF A LINE FROM MAUSTON TO BOSCOBEL WI LINE. KEEPING POPS IN THE CHANCE CATEGORY SINCE BUFKIT IS STILL SHOWING SOME SATURATION ISSUES THROUGH THE COLUMN. WILL CONTINUE TO MONITOR THIS SITUATION...BUT NOT THINKING ANY WINTER HEADLINES NEEDED AT THIS TIME. OTHERWISE...LOOK FOR OVERNIGHT LOWS IN THE 25-30 DEGREE RANGE BY 6AM. COLD AIR ADVECTION WILL BE IN PLACE ACROSS THE AREA ON MONDAY ALONG WITH CYCLONIC FLOW ALOFT. THINKING THIS WILL GIVE US A MIXED BAG OF CLOUD COVER WITH STEEPER LAPSE RATE TYPE STRATOCUMULUS AND THEN INCREASING MID CLOUD LATE IN THE AFTERNOON AHEAD LOW PRESSURE AND A WARM FRONT MOVING INTO THE DAKOTAS/WESTERN MN. HIGHS MONDAY EXPECTED TO CLIMB ONLY A COUPLE DEGREES FROM THE OVERNIGHT LOWS...TOPPING OFF IN THE MIDDLE 20S TO THE LOWER 30S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 322 PM CST SUN JAN 12 2014 12.12Z MODELS VERY CONSISTENT IN BRINGING A VIGOROUS MID-LEVEL TROUGH AND SURFACE LOW ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY. MODELS PRETTY MUCH LOCKING ONTO A COMMON SOLUTION...BRINGING THE HEAVIEST SNOW THROUGH THE I-90/94 CORRIDOR AREAS. THE NAM IS THE HIGHEST WITH ITS SNOW AMOUNTS RANGING FROM 2-5 INCHES WHILE THE ECMWF IS INDICATING 1-3 INCHES. THE GFS COMES IN AT 1-4 INCHES. SREF IS RIGHT IN THE MIDDLE WITH 1-4 INCHES. ALSO LOOKS LIKE THERE WILL BE THE POTENTIAL FOR SOME BLOWING SNOW ACROSS THE OPEN PORTIONS OF NORTHEAST IA AND SOUTHEAST MN TUESDAY AFTERNOON AS GUSTY NORTHWEST WINDS SPREAD IN BEHIND THE SURFACE LOW. DUE TO THE GIVEN SNOWFALL AMOUNTS AND WIND/BLOWING SNOW ISSUES...A WINTER WEATHER ADVISORY HEADLINE WILL EVENTUALLY BE NEEDED FOR THIS EVENT AND WILL LIKELY BE HOISTED BY THE MIDSHIFT CREW TONIGHT. OTHERWISE...LOOK FOR TEMPERATURES MONDAY NIGHT IN THE TEENS TO LOWER 20S...THEN CLIMBING THROUGH THE 20S ON TUESDAY. ANOTHER SHOT AT SOME SNOW WILL COME ALONG WEDNESDAY NIGHT AS LIFT INCREASES AHEAD OF A WARM FRONT EXTENDING FROM A VIGOROUS LOW PASSING ACROSS SOUTHERN CANADA. SNOW CHANCES WILL CONTINUE INTO THURSDAY WITH COLDER/UNSTABLE CYCLONIC FLOW ENTERING THE REGION. ANOTHER TROUGH WILL DROP INTO THE REGION THURSDAY NIGHT FOR A CONTINUED CHANCE OF LIGHT SNOW MAINLY EAST OF THE MISSISSIPPI RIVER. EXPECT LOWS WEDNESDAY NIGHT IN THE TEENS WITH HIGHS ON THURSDAY WARMING INTO THE 25 TO 32 DEGREE RANGE. COLDER AIR FILTERING INTO THE AREA THURSDAY NIGHT WILL PRODUCE LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. FRIDAY THROUGH THE WEEKEND LOOKS QUIET WEATHER-WISE AS A MID/UPPER RIDGE OF HIGH PRESSURE BUILDS IN FROM THE PLAINS. LOOK FOR HIGHS STARTING OUT COLD IN THE 10-15 DEGREE RANGE FRIDAY...MODERATING INTO THE 20S SATURDAY AND SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1100 PM CST SUN JAN 12 2014 SHORTWAVE TROUGH WILL SWEEP ACROSS THE REGION TONIGHT. THE ATMOSPHERE IS RELATIVELY DRY AND THE SYSTEM ISN/T BRINGING MUCH MOISTURE WITH IT. THERE HAS BEEN A LOWERING OF THE CIGS...BUT MOSTLY JUST A 8-12 KFT MID DECK. 88-D RADAR RETURNS HAVE INCREASED FROM CENTRAL IA INTO SOUTHWEST WI...IN A REGION OF FRONTOGENETIC FORCING. SFC OBS DON/T INDICATE ANYTHING REACHING THE SFC YET...STILL A LOT OF DRY AIR UNDER THE CLOUDS. ANY -SN/-RA THREAT SHOULD STAY SOUTH OF KRST/KLSE. A SFC COLD FRONT MOVES IN WITH THE SHORTWAVE...AND RAP/NAM/GFS ALL CONTINUE TO POINT TO LOW CIG DEVELOPMENT /MVFR/ IN THE COLD AIR POST THE FRONT - FOR MON MORNING. SEEING SOME EVIDENCE OF THIS PER LATEST FOG/STRATUS SATELLITE IMAGERY AND SFC OBS ACROSS NORTHERN MN...SO CONFIDENCE INCREASING THAT MODELS TRENDS ARE REASONABLE. RH FIELDS HOLD ONTO THE LOW LEVEL MOISTURE MUCH OF THE DAY...BUT BUFKIT SOUNDINGS POINT TO SOME MIXING BY EARLY AFTERNOON...WHICH COULD RESULT IN A PERIOD OF SCT CONDITIONS. WILL CONTINUE TO FRAME THE TAFS THIS WAY. A MORE SIGNIFICANT SHORTWAVE WILL SPIN ACROSS THE UPPER MISSISSIPPI RIVER VALLEY MONDAY NIGHT...WITH SNOW AND MVFR/IFR CIGS/VSBYS LIKELY. ACCUMULATIONS OF 1 TO 4 INCHES ARE EXPECTED. WINDS WILL INCREASE LATE MONDAY NIGHT INTO TUE...WHICH COULD LEAD TO SOME BLSN CONCERNS AT KRST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION.....RIECK
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS LITTLE ROCK AR
645 AM CST MON JAN 13 2014 .AVIATION... SCATTERED SHOWERS WILL CONTINUE OVER THE SOUTHEAST HALF OF THE STATE THIS MORNING. THIS WILL BE AHEAD OF A COLD FRONT SWEEPING INTO ARKANSAS FROM THE NORTHWEST. MVFR CEILINGS WILL EXIST AHEAD OF THE FRONT...WITH SPOTTY IFR CEILINGS IN THE FAR SOUTHEAST. HEADING INTO THIS AFTERNOON...SHOWERS WILL END...WITH VFR CONDITIONS RETURNING. THERE WILL STILL BE A LOT OF HIGH/MID CLOUDS. CLEARING WILL TAKE PLACE TONIGHT. SOUTHWEST WINDS WILL SHIFT TO THE NORTHWEST TODAY AT 8 TO 14 MPH...WITH GUSTS FROM 16 TO 22 MPH. THERE WILL BE SOME WIND SHEAR THIS MORNING IN THE SOUTHEAST...WITH WINDS AT 2000 FEET FROM THE SOUTHWEST AT AROUND 40 KNOTS. WINDS TONIGHT WILL BECOME WEST TO SOUTHWEST AT 5 TO 10 MPH. (46) && .SHORT TERM...TODAY THROUGH THURSDAY NIGHT REGIONAL RADAR IMAGERY SHOWS BROAD SWATH OF SHOWERS STRETCHING FROM THE TX/LA COASTAL BORDER UP THROUGH NORTHERN MISSISSIPPI AND INTO WESTERN TENNESSEE THIS MORNING...WELL TO THE WEST OF A COLD FRONT SITUATED FROM CENTRAL MISSOURI DOWN THROUGH FAR NWRN ARKANSAS AND INTO EASTERN OKLAHOMA. THE WESTERN EDGE OF THESE SHOWERS STRETCHES FROM MEMPHIS DOWN TO EL DORADO AND WILL MOST LIKELY CONTINUE TO HOLD THERE FOR THE REMAINDER OF THE MORNING. HOWEVER...WILL LEAVE SOME SLIGHT CHANCE POPS BACK AS FAR NORTHWEST AS THE I-30 AND US-67 CORRIDOR AS THE RAPID REFRESH RUC SHOWS SOME ISOLATED SHOWERS DEVELOPING IN THAT AREA THROUGH ROUGHLY 16Z. THE AFOREMENTIONED COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TODAY. TEMPS SHOULD BREAK THE 60 DEGREE MARK ACROSS MUCH OF SOUTHERN ARKANSAS AHEAD OF THE FRONT TODAY...WITH TEMPERATURES HOLDING STEADY OR FALLING SLIGHTLY FROM MORNING VALUES IN THE NORTHWEST. BEHIND THE FRONT...GUSTY WINDS WILL ONCE AGAIN SPREAD ACROSS THE STATE. WIND SPEEDS SHOULD REMAIN SHORT OF ANY ADVISORY LEVELS...BUT GUSTS UP TO 25 MPH WILL BE NOT BE UNCOMMON ACROSS MAINLY THE HIGHER TERRAIN IN THE NORTH AND WEST. ALOFT...THE UPPER TROUGH SUPPORTING THE SFC FRONT JUST TO THE WEST WILL MOVE OFF TO THE EAST BY THIS EVENING. ANOTHER INCOMING DISTURBANCE WILL DIVE SOUTH FROM THE PLAINS AND TRANSIT THE STATE ON TUESDAY. GUSTY NORTHWEST WINDS WILL BE NOTED ON TUE AS A RESULT. CONTINUED WITH DRY FORECAST ON TUE AS WELL AS THIS DISTURBANCE WILL HAVE VERY LITTLE MOISTURE TO WORK WITH. BUT...WOULD NOT BE SURPRISED TO SEE SOME ISOLD SHOWERS OR PATCHY RAIN IN THE NORTHEAST TUESDAY AFTERNOON. REGARDING TEMPERATURES...THEY WILL NOT TAKE A SIGNIFICANT DIVE BEHIND THE FRONT TODAY OR THE ONE COMING THROUGH TUESDAY AS NEITHER IS USHERING IN AN ARCTIC AIR MASS. RATHER THE TUESDAY FRONT WILL COOL THINGS BACK OFF TO AROUND NORMAL...WITH HIGHS ON WEDNESDAY IN THE UPPER 30S TO UPPER 40S. && .LONG TERM...FRIDAY THROUGH SUNDAY THE EXTENDED PERIOD WILL START WITH A RIDGE OVER THE WESTERN UNITED STATES...AND TROUGHING OVER AREAS EAST OF THE ROCKIES. OVER TIME...THE RIDGE OVER THE WEST WILL BUILD EASTWARD...WITH ANY TROUGHING TOWARD NEW ENGLAND. THE PATTERN WOULD SUGGEST A COLD BEGINNING ON FRIDAY...WITH ARKANSAS IN THE WAKE OF A COLD FRONT AND HIGH PRESSURE BUILDING INTO THE REGION FROM THE PLAINS. TEMPERATURES WILL BE A LITTLE BELOW NORMAL...BUT IT WILL BE NOTHING DRASTIC. IT WILL BE MUCH COLDER TOWARD THE OHIO VALLEY...WITH A GLANCING BLOW LOCALLY. AS THE PERIOD PROGRESSES...THERE SHOULD BE A WARMING TREND. THIS WILL HAPPEN AS THE HIGH SHIFTS TO THE EAST...AND RESULTS IN SOUTHERLY WINDS AROUND HERE. TEMPERATURES WILL FINISH AT OR A LITTLE ABOVE NORMAL ON SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 59 34 54 28 / 10 0 10 10 CAMDEN AR 63 36 62 31 / 20 0 0 0 HARRISON AR 57 34 50 25 / 10 0 10 0 HOT SPRINGS AR 60 35 59 29 / 20 0 10 0 LITTLE ROCK AR 62 35 60 29 / 20 0 10 10 MONTICELLO AR 63 37 62 31 / 30 10 0 10 MOUNT IDA AR 58 35 58 29 / 10 0 10 0 MOUNTAIN HOME AR 56 33 51 26 / 10 0 10 0 NEWPORT AR 60 34 55 28 / 20 0 10 10 PINE BLUFF AR 61 35 60 30 / 20 10 0 10 RUSSELLVILLE AR 60 32 57 28 / 10 0 10 0 SEARCY AR 60 32 55 28 / 20 0 10 10 STUTTGART AR 61 35 57 29 / 20 10 10 10 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...64 / LONG TERM...46
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1025 AM EST MON JAN 13 2014 .UPDATE... 15Z WATER VAPOR AND H4 RAP ANALYSIS SHOW AN AMPLIFIED UPPER LEVEL PATTERN OVER THE CONUS HIGHLIGHTED BY A LARGE PROGRESSIVE LONGWAVE TROUGH OVER THE CENTRAL PLAINS/MS VALLEY. A SHORTWAVE CAN BEEN SEEN EJECTING EASTWARD OVER THE NORTHWEST GULF OF MEXICO AROUND THE BASE OF THE MAIN LONGWAVE TROUGH. THE UPPER LEVEL PV ANOMALY SWINGING ACROSS TEXAS COMBINED FAVORABLE RRQ DYNAMICS FROM ITS ASSOCIATED JET STREAK IS FORCING A WEAK FRONTAL WAVE NEAR THE SURFACE ALONG THE TX/LA COAST. SEVERAL CLUSTERS OF CONVECTION ARE FIRING ALONG THIS WAVE THIS MORNING AND NOW APPROACHING THE MS DELTA REGION. LONGWAVE RIDGING IS SEEN ON EITHER SIDE OF THIS TROUGH OVER BOTH COASTS. THE EASTERN U.S. RIDGE EXTENDS DOWN TO THE FLORIDA PENINSULA AND WILL BE EXITING INTO THE WESTERN ATLANTIC LATER TODAY. WV IMAGERY SHOWS A PLUME OF SOUTHERN STREAM UPPER LEVEL MOISTURE IS BEGINNING TO OVERRIDE THE PENINSULA AHEAD OF THE APPROACHING TROUGH...HOWEVER A LOOK AT THE 13/12Z KTBW SOUNDING PROFILE SHOWS THAT THE MID/LOWER LEVELS ARE STILL VERY DRY WITH IMPRESSIVE DEWPOINT DEPRESSIONS OF 40-45C BELOW 500MB. WE WILL NEED SOME TIME TO MOISTEN THIS LOWER COLUMN BEFORE WE CAN START TALKING ABOUT ANY SHOWER ACTIVITY FOR OUR REGION. AT THE SURFACE NEARBY...HIGH PRESSURE IS NOW CENTERED OFF THE GA/CAROLINA COAST PROVIDING A WEAK EASTERLY FLOW ACROSS THE PENINSULA. REST OF TODAY...LOOKING AT A MIX OF SUN AND CLOUDS THROUGH THE REST OF THE MORNING...FOLLOWED BY A GENERAL INCREASE IN CLOUDS DURING THE LATER PORTION OF THE DAY AND EVENING. AS THE FRONTAL WAVE MOVES EASTWARD ALONG THE NORTHERN GULF COAST WITH ITS PARENT SHORTWAVE THROUGH THE DAY...A WEAK WARM FRONTAL FEATURE WILL ORGANIZE INTO NORTH FLORIDA. THIS LOOKS TO BE A RATHER DISORGANIZED FEATURE...AS THE UPPER LEVEL SHORTWAVE WILL BE SHEARING OUT /WEAKENING WITH TIME...NOT ALLOWING THE SURFACE REFLECTION TO ORGANIZE MUCH. STILL THAT BEING SAID...A WEAK UPGLIDE REGIME MAY ESTABLISH ENOUGH TO PRODUCE A FEW LIGHT SHOWERS FOR THE LEVY/CITRUS AND ADJACENT COASTAL WATERS AFTER 21-22Z. ANY ACTIVITY THIS EARLY WOULD BE LIGHT AND SPOTTY IN NATURE. ELSEWHERE...WITH THE SYNOPTIC FORCING FOR ASCENT REMAINING TO OUR WEST THROUGH THE DAYLIGHT HOURS...AND A COLUMN THAT REQUIRES A GOOD DEAL OF MOISTENING...DO NOT ANTICIPATE ANY SHOWER ACTIVITY...AND HAVE A RAIN FREE FORECAST THROUGH AT LEAST THE MIDDLE EVENING HOURS. LOW LEVEL COLUMN TEMPERATURE POTENTIAL IS QUITE HIGH WITH 850MB TEMPS AT 14-15C. THE OVERALL MIXING TODAY IS NOT GREAT WITH A LIGHT GRADIENT...HOWEVER...STILL THINK TEMPS WILL BE ABOVE NORMAL REACHING HIGHS FROM THE LOWER/MID 70S NORTH TO AROUND 80 IN THE SOUTH. TONIGHT... UPPER TROUGH AND ASSOCIATED WEAK HEIGHT FALLS/DCVA/Q-VECTOR CONVERGENCE AND RRQ JET DYNAMICS WILL OVERSPREAD THE REGION WITH TIME...MAXIMIZING THEIR COMBINED EFFECTS OVER THE NORTHERN HALF OF THE PENINSULA. A CLUSTER OF SHOWER AND A FEW EMBEDDED THUNDERSTORMS IS EXPECTED TO MOVE INTO THE NATURE COAST THIS EVENING...MAINLY AFTER DARK. THERE LOOKS TO BE A TIGHT GRADIENT IN THE RAIN CHANCES FROM MID EVENING THROUGH MIDNIGHT RANGING FROM CATEGORICAL > 80% AROUND LEVY/CITRUS COUNTY...RANGING DOWN TO ONLY 30% FOR THE I-4 CORRIDOR...AND THEN 20% SLIGHT CHANCE OR LESS FURTHER SOUTH. THE FRONTAL WAVE WILL PIVOT UP INTO THE CAROLINAS AFTER MIDNIGHT WITH THE COLD FRONT APPROACHING THE WEST COAST OF FLORIDA. HIGH RAIN CHANCES SHOULD EXPAND SOUTH TO THE TAMPA BAY AREA FOR THE SECOND HALF OF THE NIGHT WITH THE TIGHT POP GRADIENT SHIFTING TO OUR SOUTHERN ZONES. 80% ALONG THE I-4 CORRIDOR TO 20-30% DOWN TOWARD FORT MYERS. RETURN FLOW AHEAD OF THIS SYSTEM WILL BE MEAGER AT BEST AND HENCE SURFACE BASED INSTABILITY WILL BE VERY WEAK. PROB WILL SEE A FEW UPDRAFTS CAPABLE OF SUPPORTING THUNDERSTORMS BASED ON THE DEGREE OF SYNOPTIC FORCING...HOWEVER THE THREAT FOR ANY SEVERE WEATHER IS VERY LOW. TUESDAY/TUESDAY NIGHT... THE WEAK COLD SLOWLY SAGS THROUGH THE PENINSULA DURING THE DAY ON TUESDAY. AS THE SHORTWAVE SHEARS OUT TO THE NORTHEAST...THE OVERALL SYNOPTIC FORCING/Q-VECTOR CONVERGENCE WEAKENS WITH TIME. THERE WILL STILL BE A BROAD AREA OF WEAK SYNOPTIC FORCING OVERHEAD WITHIN THE GENERAL CYCLONIC CIRCULATION OF THE UPPER TROUGH...HOWEVER ANY SHOWER ACTIVITY WILL MOST DIRECTLY BE ATTRIBUTED TO THE LOW LEVEL FOCUS ALONG/AHEAD OF THE FRONT. THIS FOCUS WILL ALSO BE WEAKENING WITH TIME AS THE FRONT IS STRETCHED AND SLOWS. WITH ALL THIS IN MIND...EXPECT THE CLUSTERS OF SHOWERS TO BECOME LESS ORGANIZED THROUGH THE DAY WITH THE BETTER CHANCES SHIFTING SOUTH FROM THE I-4 CORRIDOR DURING THE MORNING...TO OUR SOUTHERN ZONES BY AFTERNOON. SHOULD ACTUALLY SEE THE RAIN CHANCES END FOR MUCH OF THE NATURE COAST BY THE SECOND HALF OF THE DAY. TUESDAY NIGHT...THE EASTERN U.S. UPPER TROUGH IS RE-ENFORCED/SHARPENED ONCE AGAIN BY STRONG SHORTWAVE ENERGY DROPPING OUT OF THE UPPER MS VALLEY. ALTHOUGH MUCH OF THE FORECAST AREA WILL BE TOO DRY FOR THE DYNAMICS ASSOCIATED WITH THIS NEW AMPLIFICATION TO SUPPORT RAIN...THERE MAY BE JUST ENOUGH COLUMN MOISTURE STILL LEFT OVER DOWN TOWARD CHARLOTTE/LEE COUNTY FOR THE NEWLY ARRIVING SYNOPTIC LIFT TO GET A FEW SHOWERS GOING ONCE AGAIN. WILL KEEP A LEAST A SLIGHT CHANCE POP IN THE FORECAST FOR THESE ZONES. WEDNESDAY... A SECONDARY AND MUCH STRONGER COLD FRONT WILL LEAD THIS NEXT POWERFUL TROUGH INTO THE SOUTHEAST CONUS. WITH LITTLE MOISTURE TO WORK WITH...THIS FRONT WILL HAVE A MOSTLY DRY PASSAGE...BUT LOOKS TO DELIVER ONE OF (IF NOT THE) COLDEST AIRMASS OF THE SEASON SO FAR TO PORTIONS OF THE FLORIDA PENINSULA. WEDNESDAY DURING THE DAY WILL LIKELY NOT FEEL THAT COLD AS THE FRONT WORKS IT WAY SOUTH ACROSS THE AREA. TEMPERATURES LIKELY WILL NOT RISE MUCH DO TO THE CAA...HOWEVER THE WARMER START TO THE DAY WILL KEEP THINGS MANAGEABLE. ONCE THE SUN BEGINS TO SET WEDNESDAY EVENING HOWEVER THE COLD AIR WILL CERTAINLY BEING TO BE FELT. TEMPERATURES ARE FORECAST TO DROP BELOW FREEZING WEDNESDAY NIGHT FROM BROOKSVILLE NORTHWARD...BUT WIND CHILL ISSUES ARE EXPECTED FOR JUST ABOUT THE ENTIRE FORECAST AREA. THOSE WITH AGRICULTURAL OR OUTDOOR ACTIVITIES PLANNED FOR WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS URGED TO KEEP UP WITH THE LATEST FORECASTS CONCERNING THIS NEXT UPCOMING COLD AIR EVENT. && .AVIATION... 13/12Z-14/12Z: VFR PREVAILS INTO EARLY EVENING WITH AN INCREASE IN CLOUDS AND LIGHT EASTERLY WINDS THAT BECOME SOUTHERLY AND PICK UP BUT GENERALLY NOT MORE THAN 10KT. LATER IN THE EVENING AN APPROACHING FRONT WILL SUPPORT SHOWERS AT THE NORTHERN TERMINALS...WITH JUST VCNTY REMARKS FOR NOW. DURING THE LATE NIGHT HOURS LIGHTER WINDS WILL ALLOW PATCHY BR AT SOUTHERN AIRPORTS. && .MARINE... HIGH PRESSURE WILL LOSE IT/S INFLUENCE OVER THE REGION TODAY AND TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT IS EXPECTED TO SLIDE SOUTHWARD THROUGH THE FORECAST AREA ON TUESDAY...AND WINDS MAY REACH CAUTIONARY LEVELS ACROSS PORTIONS OF THE MARINE AREA. A RE-ENFORCING COLD FRONT WILL APPROACH FORM THE NORTHWEST TUESDAY NIGHT AND THEN MOVE THROUGH THE AREA ON WEDNESDAY. WINDS ARE EXPECTED TO PICK UP IN ADVANCE OF THE FRONT LATE TUESDAY NIGHT...WITH STRONG WINDS THEN CONTINUING THROUGH THURSDAY MORNING...AND ADVISORY HEADLINES APPEAR LIKELY WEDNESDAY AND WEDNESDAY NIGHT FOR MOST IF NOT ALL WATERS. && .PRELIMINARY POINT TEMPS/POPS... TPA 76 66 71 54 / 0 80 60 0 FMY 82 67 78 56 / 0 30 40 20 GIF 79 63 73 52 / 0 60 60 10 SRQ 76 66 72 54 / 0 60 60 10 BKV 76 62 71 42 / 0 80 60 0 SPG 74 66 71 55 / 0 80 60 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE...MROCZKA AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1009 AM EST MON JAN 13 2014 .SYNOPSIS... HIGH PRESSURE WILL BE CENTERED OFF THE SOUTHEAST COAST THROUGH TONIGHT. A COLD FRONT WILL CROSS THE REGION TUESDAY...FOLLOWED BY A SECONDARY COLD FRONT WEDNESDAY NIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN THURSDAY. A STRONG COLD FRONT WILL MOVE ACROSS FRIDAY FOLLOWED BY HIGH PRESSURE NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 10 AM...NO SIGNIFICANT CHANGES THIS UPDATE. UPPER RIDGE AXIS OVER THE REGION THIS MORNING MOVES OFFSHORE TODAY. WITH SFC HIGH PRES OFF THE SE CST A DEEPER MILDER SW FLOW WILL DEVELOP. SUNNY SKIES EARLY WITH MAINLY HIGH CLOUDS INCREASING DURING THE AFTERNOON. INCREASING THICKNESSES WILL LEAD TO HIGHS IN THE 60 TO 65 DEGREE RANGE THIS AFTERNOON...ABOUT 10 DEGS ABOVE NORMAL FOR MID JANUARY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/... A ROBUST SHORTWAVE TROUGH DIGS THRU THE TN VALLEY TONIGHT. DEEPER MOISTURE QUICKLY OVERSPREADS THE SE STATES OVERNIGHT AND WILL MAINTAIN LIKELY POPS AFTER MIDNIGHT OVER THE FORECAST AREA GIVEN THE CONSISTENT MODEL SOLUTIONS. SOUTHERLY FLOW CONTINUES THE MILD TEMPERATURES OVERNIGHT WITH LOWS IN THE UPPER 40S TO LOW 50S. && .LONG TERM /TUESDAY THROUGH SUNDAY/... AS OF 3 AM MON...A PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE LONG TERM WITH SEVERAL AMPLIFIED SYSTEMS MOVING THROUGH THE FLOW ALOFT. A SHORTWAVE WILL MOVE THROUGH THE SE STATES TUE...WITH A WEAK AREA OF LOW PRES LIFTING ACROSS THE AREA...AND A COLD FRONT PUSHING THROUGH EASTERN NC TUE AFTERNOON. CONTINUED LIKELY POPS INLAND...AND INCREASED TO CATEGORICAL ALONG THE COAST. MODELS STILL INDICATING STRONG LOW LEVEL SHEAR WILL BE IN PLACE...HOWEVER SEVERE CHANCES APPEAR MINIMAL AT THIS TIME AS MODELS CONTINUE TO SHOW LITTLE/NO INSTABILITY ACROSS THE AREA EXCEPT THE OFFSHORE WATERS...AND WILL MAINTAIN CHC THUNDER THERE. SOUTHERLY FLOW BRINGS ABOVE NORMAL TEMPS TUE WITH HIGHS IN THE UPPER 50S TO LOWER 60S. A LONGWAVE UPPER TROUGH WILL REMAIN ACROSS THE EASTERN CONUS TUE NIGHT WITH ANOTHER ROBUST SHORTWAVE TROUGH AND COLD FRONT PROGGED TO PUSH ACROSS THE REGION WED AND THU. A 12Z GFS/ENSEMBLE COMPROMISE IS FAVORED THIS TIME PERIOD AS THEY HAVE BEEN THE MOST CONSISTENT. FORCING AHEAD OF THIS TROUGH COULD BRING ADDITIONAL RAIN CHANCES WED BUT MOISTURE EXPECTED TO BE LIMITED AND QPF AMOUNTS EXPECTED TO BE LIGHT. THE UPPER TROUGH QUICKLY PUSHES OFFSHORE EARLY THU WITH SHORTWAVE RIDGING AND SFC HIGH PRES PROGGED TO BRIEFLY BUILD INTO THE REGION THU. THE 00Z ECMWF RUN VERY SIMILAR TO PREVIOUS 12Z...WHICH IS MORE AMPLIFIED WITH THE SHORTWAVE WED AND THURS...AND THEN DEVELOPS A CUTOFF LOW ACROSS THE SOUTHEAST WED NIGHT AND LIFTING A LOW PRES AREA JUST OFFSHORE THU. THIS SOLUTION WOULD DELAY PCPN UNTIL WED NIGHT AND THU...BE WETTER AND POSSIBLY BRING P-TYPE CONCERNS INTO THE FORECAST. WPC CONTINUES TO FAVOR THE GFS AND ENSEMBLE SOLUTIONS AS OPPOSED TO LATEST ECMWF OPERATIONAL RUNS. CYCLONIC FLOW RETURNS ALOFT THU NIGHT AND FRI WITH THE SFC HIGH PRES SLIDING OFFSHORE AHEAD OF THE NEXT FRONTAL SYSTEM. MOISTURE LOOKS RATHER LIMITED WITH THIS NRN STREAM SYSTEM AS WELL WITH MAINLY A DRY FRONTAL PASSAGE FRI EVENING. HIGH PRES BUILDS INTO THE REGION FROM THE WEST OVER THE WEEKEND. TEMPS SLIGHTLY BELOW SEASONAL NORMS EXPECTED LATE IN THE WEEK AND INTO NEXT WEEKEND...WITH HIGHS IN THE 40S AND LOWS IN THE UPPER 20S/MID 30S. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... SHORT TERM /THROUGH 12Z TUESDAY/... SFC HIGH PRES HAS MOVED OFFSHORE TO THE SOUTH OF THE AREA AND VFR CONDITIONS WILL PREVAIL TODAY WITH SCT CLOUDS AND SW WINDS AROUND 10 KT. CLOUDS INCREASE DURING THE LATE EVENING BUT EXPECT CIGS REMAIN VFR THRU AROUND 09Z THEN LOWERING AS STEADIER PRECIP OVERSPREADS THE AREA. CONDITIONS INITIALLY DROPPING INTO MVFR CATEGORY WITH IFR POSSIBLE VERY LATE IN THE FORECAST PERIOD. LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3 AM MON...SUB-VFR CONDITIONS LIKELY TUE WITH WIDESPREAD SHOWERS ACROSS THE AREA. DRIER AIR RETURNS FOR MIDWEEK...EXPECT PRED VFR CONDITIONS...THOUGH COULD SEE ISOLATED SHOWERS WED WITH SECONDARY FRONTAL PASSAGE. HIGH PRES BUILDS ACROSS THE AREA THU WITH ANOTHER DRY FRONTAL PASSAGE EXPECTED LATE FRI. && .MARINE... SHORT TERM /THROUGH TONIGHT/... MADE MINOR TWEAKS TO THE WINDS GIVE CURRENT LIGHT CONDITIONS ACROSS THE WATERS UNDER HIGH PRESSURE. INCORPORATED MORE RUC AND HIGH RES NMM...AND 12Z NAM INTO FORECAST FOR TODAY. WINDS WILL STILL INCREASE DURING THE AFTERNOON TO 10 TO 15 KT FROM THE CENTRAL WATERS SOUTH...BUT MIGHT HOLD OFF UNTIL EARLY THIS EVENING NORTHERN WATERS. ALSO INCORPORATED SOME OF THE 06Z WW3 GUIDANCE INTO OUR WAVE FORECAST TO SLOW INCREASE OF SEAS JUST SLIGHTLY GIVEN LIGHT WINDS. SEAS WILL STILL BUILD TO 3 TO 4 FT THIS AFTN...POSS 5 FT OUTER CNTRL WTRS LATE. WINDS CONTINUE TO RAMP UP OVERNIGHT AS COLD FRONT NEARS THE COAST WITH SW WINDS MAINLY 15-20 KT AND SEAS BUILDING TO 3-5 FT OVERNIGHT. LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3 AM MON...ELEVATED SEAS AND GUSTY SWLY WINDS WILL START OFF THE PERIOD TUE...AS A WEAK AREA OF LOW PRESSURE WILL LIFT NORTH THROUGH THE WATERS...WITH A WEAK COLD FRONT MOVING THROUGH TUE AFTERNOON. SW WINDS 15-25KT AND SEAS 4-7FT LIKELY TUE...WITH A PERIOD OF SCA CONDITIONS EXPECTED. WINDS BRIEFLY BECOME W 5-15 KT TUE NIGHT WITH SEAS SUBSIDING TO 3-5 FT. HOWEVER...WINDS QUICKLY BACK TO SW AND INCREASE TO 15-25 KT WED AHEAD OF A SECONDARY FRONT PROGGED TO MOVE ACROSS THE WATERS WED AFTERNOON/EVENING. STRONGER CAA BEHIND THIS FRONT WILL KEEP WINDS GUSTY...NW AROUND 15-25 KT...INTO THU MORNING. SEAS GENERALLY 3-6 FT WED INTO THU MORNING. WILL CONTINUE TO DISCOUNT THE OPERATIONAL ECMWF SOLUTION OF LIFTING ANOTHER LOW PRES AREA THURS AS THIS SOLUTION IS AN OUTLIER. WINDS BACK TO SW AND INCREASE TO 15-25 KT WITH SEAS INCREASING TO 4-6 FT FRI AHEAD OF YET ANOTHER FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...RSB/BTC SHORT TERM...BTC LONG TERM...SK/CQD AVIATION...BTC/CQD MARINE...RSB/BTC/SK/CQD
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1156 AM CST MON JAN 13 2014 .AVIATION... FOR KHRO AND KBPK...VFR THROUGHOUT THE PERIOD. FOR KADF...KHOT... AND KLIT BRIEF MVFR TIL 20Z...OTHERWISE VFR. FOR KPBF AND KLLQ...FQT IFR DUE TO LOW CEILINGS AND SOME -RA TIL AROUND 22Z...THEN BECOMING VFR. && .PREV DISCUSSION... /ISSUED 645 AM CST MON JAN 13 2014/ AVIATION... SCATTERED SHOWERS WILL CONTINUE OVER THE SOUTHEAST HALF OF THE STATE THIS MORNING. THIS WILL BE AHEAD OF A COLD FRONT SWEEPING INTO ARKANSAS FROM THE NORTHWEST. MVFR CEILINGS WILL EXIST AHEAD OF THE FRONT...WITH SPOTTY IFR CEILINGS IN THE FAR SOUTHEAST. HEADING INTO THIS AFTERNOON...SHOWERS WILL END...WITH VFR CONDITIONS RETURNING. THERE WILL STILL BE A LOT OF HIGH/MID CLOUDS. CLEARING WILL TAKE PLACE TONIGHT. SOUTHWEST WINDS WILL SHIFT TO THE NORTHWEST TODAY AT 8 TO 14 MPH...WITH GUSTS FROM 16 TO 22 MPH. THERE WILL BE SOME WIND SHEAR THIS MORNING IN THE SOUTHEAST...WITH WINDS AT 2000 FEET FROM THE SOUTHWEST AT AROUND 40 KNOTS. WINDS TONIGHT WILL BECOME WEST TO SOUTHWEST AT 5 TO 10 MPH. (46) SHORT TERM...TODAY THROUGH THURSDAY NIGHT REGIONAL RADAR IMAGERY SHOWS BROAD SWATH OF SHOWERS STRETCHING FROM THE TX/LA COASTAL BORDER UP THROUGH NORTHERN MISSISSIPPI AND INTO WESTERN TENNESSEE THIS MORNING...WELL TO THE WEST OF A COLD FRONT SITUATED FROM CENTRAL MISSOURI DOWN THROUGH FAR NWRN ARKANSAS AND INTO EASTERN OKLAHOMA. THE WESTERN EDGE OF THESE SHOWERS STRETCHES FROM MEMPHIS DOWN TO EL DORADO AND WILL MOST LIKELY CONTINUE TO HOLD THERE FOR THE REMAINDER OF THE MORNING. HOWEVER...WILL LEAVE SOME SLIGHT CHANCE POPS BACK AS FAR NORTHWEST AS THE I-30 AND US-67 CORRIDOR AS THE RAPID REFRESH RUC SHOWS SOME ISOLATED SHOWERS DEVELOPING IN THAT AREA THROUGH ROUGHLY 16Z. THE AFOREMENTIONED COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TODAY. TEMPS SHOULD BREAK THE 60 DEGREE MARK ACROSS MUCH OF SOUTHERN ARKANSAS AHEAD OF THE FRONT TODAY...WITH TEMPERATURES HOLDING STEADY OR FALLING SLIGHTLY FROM MORNING VALUES IN THE NORTHWEST. BEHIND THE FRONT...GUSTY WINDS WILL ONCE AGAIN SPREAD ACROSS THE STATE. WIND SPEEDS SHOULD REMAIN SHORT OF ANY ADVISORY LEVELS...BUT GUSTS UP TO 25 MPH WILL BE NOT BE UNCOMMON ACROSS MAINLY THE HIGHER TERRAIN IN THE NORTH AND WEST. ALOFT...THE UPPER TROUGH SUPPORTING THE SFC FRONT JUST TO THE WEST WILL MOVE OFF TO THE EAST BY THIS EVENING. ANOTHER INCOMING DISTURBANCE WILL DIVE SOUTH FROM THE PLAINS AND TRANSIT THE STATE ON TUESDAY. GUSTY NORTHWEST WINDS WILL BE NOTED ON TUE AS A RESULT. CONTINUED WITH DRY FORECAST ON TUE AS WELL AS THIS DISTURBANCE WILL HAVE VERY LITTLE MOISTURE TO WORK WITH. BUT...WOULD NOT BE SURPRISED TO SEE SOME ISOLD SHOWERS OR PATCHY RAIN IN THE NORTHEAST TUESDAY AFTERNOON. REGARDING TEMPERATURES...THEY WILL NOT TAKE A SIGNIFICANT DIVE BEHIND THE FRONT TODAY OR THE ONE COMING THROUGH TUESDAY AS NEITHER IS USHERING IN AN ARCTIC AIR MASS. RATHER THE TUESDAY FRONT WILL COOL THINGS BACK OFF TO AROUND NORMAL...WITH HIGHS ON WEDNESDAY IN THE UPPER 30S TO UPPER 40S. LONG TERM...FRIDAY THROUGH SUNDAY THE EXTENDED PERIOD WILL START WITH A RIDGE OVER THE WESTERN UNITED STATES...AND TROUGHING OVER AREAS EAST OF THE ROCKIES. OVER TIME...THE RIDGE OVER THE WEST WILL BUILD EASTWARD...WITH ANY TROUGHING TOWARD NEW ENGLAND. THE PATTERN WOULD SUGGEST A COLD BEGINNING ON FRIDAY...WITH ARKANSAS IN THE WAKE OF A COLD FRONT AND HIGH PRESSURE BUILDING INTO THE REGION FROM THE PLAINS. TEMPERATURES WILL BE A LITTLE BELOW NORMAL...BUT IT WILL BE NOTHING DRASTIC. IT WILL BE MUCH COLDER TOWARD THE OHIO VALLEY...WITH A GLANCING BLOW LOCALLY. AS THE PERIOD PROGRESSES...THERE SHOULD BE A WARMING TREND. THIS WILL HAPPEN AS THE HIGH SHIFTS TO THE EAST...AND RESULTS IN SOUTHERLY WINDS AROUND HERE. TEMPERATURES WILL FINISH AT OR A LITTLE ABOVE NORMAL ON SUNDAY. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 59 34 54 28 / 10 0 10 10 CAMDEN AR 63 36 62 31 / 20 0 0 0 HARRISON AR 57 34 50 25 / 10 0 10 0 HOT SPRINGS AR 60 35 59 29 / 20 0 10 0 LITTLE ROCK AR 62 35 60 29 / 20 0 10 10 MONTICELLO AR 63 37 62 31 / 30 10 0 10 MOUNT IDA AR 58 35 58 29 / 10 0 10 0 MOUNTAIN HOME AR 56 33 51 26 / 10 0 10 0 NEWPORT AR 60 34 55 28 / 20 0 10 10 PINE BLUFF AR 61 35 60 30 / 20 10 0 10 RUSSELLVILLE AR 60 32 57 28 / 10 0 10 0 SEARCY AR 60 32 55 28 / 20 0 10 10 STUTTGART AR 61 35 57 29 / 20 10 10 10 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...28
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
352 PM MST MON JAN 13 2014 .SHORT TERM...WINDS STILL GUSTY ACROSS HIGHER MOUNTAINS AND ALONG FOOTHILLS. CURRENT GUST OF 73 MPH IN THE SUGARLOAF MOUNTAIN AREA. GUSTS HAVE BEEN SLOWLY DECREASING IN RESPONSE TO WEAKENING GRADIENT FROM GRAND JUNCTION TO DENVER AND JET MAX SHIFTING INTO PLAINS STATES. LATEST HRRR AND RAP SHOW GUSTS CONTINUING TO DECREASE BY 00Z...WITH SPATIAL CROSS SECTIONS SHOWING CROSS MOUNTAIN FLOW AROUND 45 KTS AT MOUNTAIN TOP AT THAT TIME. WINDS WILL CONTINUE TO DECREASE THROUGH THE EVENING. WILL ALLOW HIGH WIND WARNING TO EXPIRE AT 23Z. AS FOR SNOW...WEB CAMS STILL SHOWING SOME LIGHT SNOW ALONG THE CONTINENTAL DIVIDE OF SUMMIT AND GRAND COUNTIES...THOUGH CONDITIONS HAVE BEEN SLOWLY IMPROVING. SNOTEL DATA INDICATING SNOW ALSO OCCURRING ACROSS ZONE 31. AREAS OF BLOWING SNOW STILL ONGOING ACROSS MOST OF THE HIGH COUNTRY...MAINLY HIGHER MOUNTAIN PASSES. MODEL CROSS SECTIONS SHOW MOISTURE INCREASING ACROSS THE MOUNTAINS BY MIDNIGHT AS WEAK MID LEVEL DISTURBANCE MOVES ACROSS WYOMING. THIS SHOULD KEEP SOME SNOW GOING ACROSS THE MOUNTAINS...MAINLY NORTH OF INTERSTATE 70. BEST LIFT TO BE ACROSS NORTHWEST COLORADO. WILL KILL THE WINTER STORM WARNING FOR ZONES 33 AND 34 WITH THIS ISSUANCE...AND HOIST A SNOW AND BLOWING SNOW ADVISORY FOR ZONE 31 THROUGH 18Z TUESDAY WITH AN ADDITIONAL 3 TO 6 INCHES ALONG WITH AREAS OF BLOWING SNOW. LESS SNOW EXPECTED FOR REST OF MOUNTAINS THOUGH AREAS OF BLOWING SNOW SHOULD PERSIST. ACROSS PLAINS...WINDS TO DECREASE DURING THE EVENING AS SURFACE PRESSURE BEGINS TO RISE AHEAD OF AN APPROACHING FRONT. THIS FRONT ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE WILL PUSH INTO NORTHEAST COLORADO AFTER MIDNIGHT. APPEARS FRONT SHOULD REACH DENVER AREA AROUND 11Z WITH WIND SHIFT TO THE NORTH. SOME INCREASE IN MID LEVEL MOISTURE OVERNIGHT. WITH JET ACROSS CENTRAL PLAINS STATES...THERE WILL BE A CHANCE FOR LIGHT SNOW ACROSS NORTHEAST COLORADO AND THE POTENTIAL FOR BANDED SNOWFALL AROUND 12Z. AT THIS TIME IT LOOKS LIKE THE BANDED SNOWFALL WILL OCCUR NORTHEAST OF DENVER...BUT THERE IS A CHANCE THAT THIS BAND COULD END UP FURTHER WEST TUESDAY MORNING. WILL GO WITH THE CHANCE POPS FOR MOST OF NORTHEAST CO FOR NOW. ANY ACCUMULATION SHOULD BE LESS THAT ONE HALF INCH. MOISTURE AND WINDS WILL BE ON THE DECREASE ACROSS THE MOUNTAINS DURING THE DAY TUESDAY MINIMAL ACCUMULATIONS ON WEST FACING SLOPES. ACROSS PLAINS. SNOW CHANCES TO END BY 20Z SOME INCREASE IN NORTHWEST WINDS. AIRMASS ACROSS PLAINS TO BE COOLER WITH HIGHS AROUND 40 DEGREES. .LONG TERM...A DRY AND SUBSIDENT AIRMASS WILL BUILD OVER THE FORECAST AREA THROUGH TOMORROW NIGHT AND WEDNESDAY. ANY SNOW SHOWERS TRAPPED IN THE HIGH MOUNTAINS WILL BE ENDING DURING THE EVENING AS AIRMASS DRIES SIGNIFICANTLY. WITH REGARD TO WIND...CROSS MOUNTAIN COMPONENT DECREASES TO ABOUT 30 KTS...BUT A MEAN STATE CRITICAL LAYER DEVELOPS. THIS MAY RESULT IN TRAPPED MOUNTAIN WAVE ENERGY REACHING THE FOOTHILLS...SO WILL CONTINUE THE GUSTY WIND FORECAST IN/NEAR THE FRONT RANGE MOUNTAINS AND FOOTHILLS. PLAINS WINDS SHOULD GRADUALLY RELAX AS MIXING DECREASES OVERNIGHT TUESDAY NIGHT...BUT THEN STRENGTHEN AGAIN WEDNESDAY WITH DAYTIME HEATING AND MIXING. TEMPERATURES WILL TURN WARMER WITH STRONG WARM ADVECTION AND 700 MB READINGS WARMING TO NEAR 0C. THIS WOULD SUPPORT WEDNESDAYS HIGHS WELL INTO THE 50S AND POSSIBLY 60F ALONG THE FRONT RANGE. BY THURSDAY...ANOTHER FRONT IS EXPECTED TO REACH THE FORECAST AREA WITH MORE GUSTY WINDS BUT COOLER TEMPERATURES. NO PRECIPITATION IS EXPECTED AT THIS TIME AS AIRMASS REMAINS TOO DRY. WARMER WEATHER WILL THEN REDEVELOP BY FRIDAY AND LIKELY LAST THROUGH THE WEEKEND WITH UPPER RIDGE BUILDING TO OUR WEST. THERE IS STILL WEAK TO MODERATE NORTHWEST FLOW ALOFT THOUGH...SO WE WONT BE TOTALLY IMMUNE TO WEAK FRONTS BACKING ACROSS THE PLAINS. OVERALL...TEMPERATURES SHOULD AVERAGE SEVERAL DEGREES ABOVE NORMAL. PERHAPS A LITTLE MORE SIGNIFICANT BUT BRIEF COOLING IS ADVERTISED TO REACH THE AREA BY EARLY NEXT WEEK...BUT EVEN THEN READINGS LOOK TO BE NEAR NORMAL. NO PRECIPITATION IS EXPECTED DURING THIS PERIOD AS WELL. && .AVIATION...GUSTY WEST TO NORTHWEST WINDS ACROSS AREA AIRPORTS TO GRADUALLY DECREASE THROUGH THE EVENING...TRENDING TOWARD DRAINAGE BY 03Z. SOME GUSTS TO 40 KTS STILL POSSIBLE AT KBJC THROUGH 02Z. WINDS TO THEN SHIFT TO THE NORTHWEST AROUND 08Z AHEAD OF AN APPROACHING COLD FRONT. THE FRONT IS EXPECTED TO MOVE ACROSS THE AREA AIRPORTS AROUND 11Z WITH A WIND SHIFT TO THE NORTH. MID LEVEL MOISTURE WILL INCREASE AFTER MIDNIGHT AND GRADUALLY LOWER AROUND 10Z. CEILINGS OF AROUND 6000 FEET AGL WITH BE POSSIBLE BETWEEN 11Z AND 16Z ALONG WITH A CHANCE FOR LIGHT SNOW. AT THIS TIME...VFR CONDITIONS SHOULD PREVAIL. AFTER 18Z WINDS TO SHIFT TO THE NORTHWEST WITH DECREASING CLOUDS. SOME GUSTS TO 20 KTS WILL BE POSSIBLE...MAINLY AT KDEN AND KBJC. && .BOU WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL NOON MST TUESDAY FOR COZ031. && $$ SHORT TERM...D-L LONG TERM....BARJENBRUCH AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1022 AM MST MON JAN 13 2014 .UPDATE... && .SHORT TERM...WINDS BECOMING QUITE GUSTY ALONG THE FOOTHILLS WITH A RECENT GUSTS TO 84 MPH IN THE SUGARLOAF MOUNTAIN AREA AND 75 AT WONDERVU. NORTHWEST WINDS ALSO SPREADING ONTO PLAINS...WITH SOME GUSTS AROUND 60 MPH NEAR THE FOOTHILLS AND NEAR WYOMING BORDER. WINDS ALSO GUSTY ACROSS THE HIGHER MOUNTAIN RIDGES AND ACROSS SOUTH PARK WITH AREAS OF BLOWING SNOW AND REDUCED VISIBILITY. WEB CAMS SHOWING AREAS OF LIGHT SNOW ACROSS MUCH OF THE MOUNTAINS WITH GOOD OROGRAPHICS AND UPPER LEVEL JET OVER NORTHERN COLORADO. LATEST RAP AND HRRR SHOWS WIND GUSTS TO REMAIN STRONG ALONG FOOTHILLS THROUGH ABOUT 22Z THEN DECREASE AS NOSE OF UPPER JET MOVES EAST OF STATE AND MOUNTAIN WAVE DECREASES. CURRENT HIGH WIND WARNING LOOKING GOOD FOR THE FOOTHILLS THROUGH THE AFTERNOON. AT THIS TIME...DON`T THINK IT WILL NEED TO BE EXTENDED. MODELS SHOW THE LIGHT SNOW TO CONTINUE ACROSS THE MOUNTAINS WITH OROGRAPHIC COMPONENT IN PLACE...THOUGH MOISTURE APPEARS TO DECREASE BY THE EVENING. WILL CONTINUE WINTER STORM WARNING THROUGH THE AFTERNOON...MAINLY DUE TO THE BLOWING SNOW OVER THE HIGHER MOUNTAIN PASSES. OVERALL...CURRENT FORECAST LOOK ON TRACK THROUGH THIS EVENING. SOME CHANCE FOR LIGHT SNOW OVERNIGHT WITH WEAK SURFACE FRONT AND JET IN THE VICINITY. AT THIS TIME...ANY ACCUMULATION ACROSS THE PLAINS LOOKS LIGHT. SOME ACCUMULATION FOR THE MOUNTAINS...DO NOT THINK AN ADVISORY WILL BE NEEDED AT THIS TIME. .AVIATION...OVERALL...CURRENT TAF TRENDS LOOK REASONABLE AND WILL CONTINUE FOR THE UPCOMING ISSUANCE. WINDS HAVE BECOME WESTERLY ACROSS KDEN AND KAPA WITH WESTERLY WINDS AT KBJC. WILL DELAY THE NORTHWEST COMPONENT AT KDEN UNTIL 19Z. SOME GUSTS TO 30 KTS POSSIBLE AT KDEN AND KAPA THROUGH 22Z WITH POSSIBLE GUSTS AROUND 50 KTS AT KBJC. WINDS TO THEN DECREASE BY 00Z. WEAK FRONT EXPECTED AFTER 12Z WITH WINDS SHIFTING TO THE NORTH NORTHEAST. SLIGHT CHANCE FOR A SNOW SHOWER BETWEEN 12Z AND 16Z WITH CEILINGS AROUND 6000 FEET AGL. CONFIDENCE LOW AT THIS TIME TO INCLUDE IN TAFS. && .PREV DISCUSSION... /ISSUED 317 AM MST MON JAN 13 2014/ SHORT TERM...THE STRONG NORTHWESTERLY FLOW WILL CONTINUE OVER THE MOUNTAINS TO COLORADO TONIGHT. THE NOSE OF THE UPPER LEVEL JETSTREAM STRETCHING FM NORTHERN COLORADO INTO SOUTHWESTERN CANADA...WILL GRADUALLY TRANSLATE TO THE EAST THROUGH THE DAY. ASIDE FM THE OROGRAPHIC COMPONENT TO THE SNOW ALREADY IN PLACE...THERE IS ALSO THE POTENTIAL FOR SOME ENHANCED BANDS ASSOCIATED WITH THE PRESENCE OF THE UPPER JET. BOTTOM LINE WILL BE TO CONTINUE TO WINTER STORM WARNING FOR THE NORTH CENTRAL MTNS THROUGH 5 PM THIS AFTN. SPATIAL CROSS-SECTIONS STILL SHOW MOUNTAIN WAVE ENHANCEMENT OVER THE FOOTHILLS AS WELL...WITH GREATEST OF WHICH IS PROGGED TO OCCUR FM AROUND 15Z TO 21Z. CURRENT HIGH WIND WARNING STILL LOOKS GOOD REGARDING THE TIMING SO NO CHANGES THERE EITHER. THE URBAN CORRIDOR AND NORTHEAST PLAINS SHOULD STAY DRY THROUGH THE DAY WITH STRONG WINDS AGAIN...ESPECIALLY NEAR THE FOOTHILLS AND ALONG THE WY/NEB BORDERS. FOR TNGT...THE UPPER LEVEL JET WILL SHIFT TO THE GREAT PLAINS REGION. THE MDLS ALL GENERATE SOME QPF OVER NERN CO LATE TONIGHT...AROUND 12Z...SO THE POTENTIAL FOR BANDED SNOWFALL WILL SHIFT TO THIS REGION. HAVE INCREASED THE POPS TO CHC CATEGORY AFTER 09Z FOR THE FAR NERN PLAINS. WIND/SNOW WILL PERSIST IN THE HIGH COUNTRY BUT DO NOT ANTICIPATE EITHER WL BE ENOUGH TO EXTEND THE CURRENT HIGHLIGHTS...BUT A WINTER WEATHER ADVISORY MAY BE NEEDED FOR THE MOUNTAINS TONIGHT. WL LET THE DAY SHIFT HAVE THE FINAL SAY ON THIS. LONG TERM...TUESDAY THROUGH SUNDAY...COLD FRONT WILL HAVE PUSHED THROUGH NORTHEAST COLORADO BY SUNRISE TUESDAY MORNING. GUSTY NORTHERLY WINDS BEHIND IT WILL PREVAIL ACROSS THE PLAINS AND USHER IN COOLER AIR. MODELS HINTING AT WINDS ANTICYCLONING OVER THE DENVER AREA...WHICH MAY LEAD TO WEAKER WINDS AND VARIABLE DIRECTION. WILL HAVE 10-30 POPS IN THE FORECAST BECAUSE THE AREA WILL BE UNDER THE FRONT LEFT PART OF THE JET. BEST CHANCE WILL BE DURING THE MORNING HOURS. SNOW MAY LINGER INTO THE EVENING HOURS OVER THE MOUNTAINS UNDER THE NORTHWEST FLOW ALOFT. DRIER AIR MOVING IN WILL BRING MOUNTAIN SNOW TO AN END BY WEDNESDAY MORNING. WARMER CONDITIONS WILL RETURN WEDNESDAY WITH HIGHS ABOVE 50 FOR SOME AREAS. IT WILL BE BREEZY AGAIN IN THE FOOTHILLS WHERE GUSTS TO 40 MPH WILL BE POSSIBLE. ANOTHER WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA WEDNESDAY NIGHT OR EARLY THURSDAY AS A SHORT WAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS. NOT ENOUGH MOISTURE WITH THIS SYSTEM TO PRODUCE ANY PRECIPITATION. IT WILL BE WINDY BEHIND THE FRONT OVER NORTHEAST COLORADO THURSDAY. AN UPPER LEVEL RIDGE WILL BE ALONG THE WEST COAST FRIDAY AND SLOWLY MOVE OVER THE GREAT BASIN AND ROCKIES THIS WEEKEND. THIS WILL KEEP THE COLORADO DRY THROUGH SUNDAY. NEAR NORMAL TEMPERATURES WILL PREVAIL FRIDAY AND WARM UP INTO THE 50S THIS WEEKEND AS THE RIDGE APPROACHES THE STATE. AVIATION...VFR CONDITIONS EXPECTED THROUGH 12Z. SWLY WINDS WL BECOME WNWLY WITH GUSTS TO 30 KTS EXPECTED AFTER 19Z. STRONGEST WINDS WL BE AT BJC WITH GUSTS AOA 50 KTS UNTIL 20Z...THEN THE STRONGER GUSTS SHOULD START TO LESSEN. CIGS COULD DROP TO 4-5KT AFTER 12Z TUE...WITH BANDED SNOWFALL POSSIBLE TO THE NORTH AND EAST OF DENVER. WINDS ARE FCST TO BECOME NNELY AS WELL AROUND 12Z TUE. A FEW FLURRIES MAY BE POSSIBLE AT THAT TIME SO WL ADD VCSH TO THE UPCOMING TAFS TO REFLECT THIS IN THE OUTLOOK PERIOD FOR KDEN. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 4 PM MST THIS AFTERNOON FOR COZ035-036. WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ031- 033-034. && $$ SHORT TERM...D-L LONG TERM....MEIER AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
356 PM EST MON JAN 13 2014 .SYNOPSIS... A COLD FRONTAL BOUNDARY LOCATED FROM THE GULF COAST STATES TO THE GREAT LAKES WILL MOVE EAST TONIGHT. LOW PRESSURE WILL DEVELOP ALONG THIS FRONT IN THE SOUTHEASTERN UNITED STATES MOVING INTO THE MID-ATLANTIC REGION BY TUESDAY ACCOMPANYING THE COLD FRONT. ANOTHER COLD FRONTAL BOUNDARY WILL PASS THROUGH THE REGION ON WEDNESDAY. WITH LOW PRESSURE DEVELOPING OFFSHORE WEDNESDAY NIGHT AND THURSDAY. ANOTHER FRONTAL BOUNDARY AND LOW PRESSURE SYSTEM WILL APPROACH THE REGION FOR THE FRIDAY NIGHT AND SATURDAY TIME PERIOD. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... TEMPERATURES THIS EVENING WILL START OFF FAIRLY MILD AND DIURNAL RANGE FOR TONIGHT WILL BE TRIMMED BASED ON INCREASING CLOUD COVER. RAISED TEMPERATURES FOR TONIGHTS LOW BY SEVERAL DEGREES, USING BLEND OF MAV AND RUC GUIDANCE. LAV GUIDANCE WAS USED FOR LATER AFTERNOON PERIOD BLENDING INTO BEGINNING OF THIS TIME PERIOD. PREVIOUS FORECAST TIMING FOR PRECIPITATION ONSET STILL LOOKS GOOD AND WAS LEFT UNCHANGED. DID UPDATE WITH LATEST WPC QPF GUIDANCE. RAINFALL AMOUNTS ARE RELATIVELY LIGHT. GIVEN MILD OVERNIGHT TEMPERATURES, PRECIPITATION FORECAST CONTINUES ALL LIQUID. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... A WET START TO THE DAY THOUGH AMOUNTS STILL LOOKS TO BE RELATIVELY LIGHT. TOTAL QPF AMOUNTS EXPECTED TO BE UNDER A HALF INCH. PRECIPITATION WILL BE OVER WITH PRIOR TO THE END OF THIS TIME PERIOD. BETWEEN CLOUD COVER EARLY AND COLD AIR ADVECTION LATER IN THE DAY, DAYTIME HIGH TEMPERATURES WILL RUN ONLY 8 TO 10 DEGREES OVER PREVIOUS NIGHT MINIMUM. THAT BEING SAID, STILL QUITE MILD TEMPERATURES FOR MID-JANUARY. USED MET/MAV BLEND FOR DAYTIME HIGH TEMPERATURES. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... TUESDAY NIGHT: SHOULD SEE A GRADUAL REDUCTION IN CLOUDS WITH A BRIEF BREAK BEFORE THE NEXT SYSTEM MOVES INTO THE REGION. WESTERLY FLOW MAY TURN QUICKLY TO SOUTHERLY FLOW BY MORNING WITH 850 MB TEMPS ONLY FALLING TO AROUND 0C. DO NOT EXPECT MUCH OF A TEMPERATURE DROP. FAIRLY TIGHT CLUSTER WITH REGARDS TO MODELS IN THIS PERIOD WITH MOST ELEMENTS. WEDNESDAY: THE NEXT FRONTAL BOUNDARY SHOULD BE QUICKLY MOVING INTO THE REGION BY WEDNESDAY AFTERNOON WITH WAA AHEAD OF THE BOUNDARY. A WEAK DISTURBANCE MAY RESULT IN SOME SCATTERED SHOWERS, MAINLY IN THE FORM OF RAIN AHEAD OF THE FRONT TEMPERATURES MAY WARM WELL INTO THE 40`S. IN FACT THE TIMING OF THIS SYSTEM LOOKS SLOWER WHICH KEEPS US ON THE WARM SIDE LONGER RESULTING IN A WARMING TREND FROM PREVIOUS FORECASTS IN THIS PERIOD. DID NOT GO AS HIGH AS THE 12Z MEX- 51 AT PHL BUT DID RAISE TEMPS. QPF SHOULD BE FAIRLY LIGHT WITH THE LACK OF DEEP MOISTURE PRESENT MAINLY USED A 09Z SREF/ 12Z MOS BLEND FOR POPS AND WENT A LITTLE WETTER THAN THE 09Z SREF FOR QPF. WEDNESDAY NIGHT AND THURSDAY: THE PATTERN SHOULD BECOME MORE AMPLIFIED DURING THIS TIME PERIOD. A TREND THAT STARTED WITH YESTERDAY`S 12Z ECMWF. STRONGER DISTURBANCES MARKED WITH INCREASED 500 MB VORTICITY ARE LIKELY TO ROUND THE BEND IN THE AMPLIFYING TROUGH ALLOWING FOR POTENTIAL LOW PRESSURE DEVELOPMENT. THE QUESTION IS DO THEY TRACK CLOSE ENOUGH TO THE COAST TO IMPACT OUR WEATHER? WELL IT LOOKS TO BE A CLOSE MISS AT THIS POINT WITH POTENTIAL FOR SOME ORGANIZATION OF A LOW PRESSURE SYSTEM OFF THE CAROLINA COAST MOVING OUT TO SEA. THE OVERALL PROGRESSIVE NATURE OF THE PATTERN WOULD ALSO SUPPORT THIS. A CHANCE FOR RAIN AND SNOW WOULD OCCUR FOR THE SOUTHERN AND COASTAL SECTIONS OF THE REGION AS CAA MOVES INTO THE REGION WITH THE NORTHERN/ WESTERN REGIONS DRY. A FEATURE OF NOTE WHICH SHOWED UP ON BOTH THE ECMWF AND CMC 12Z RUNS WAS AN INVERTED TROUGH WHICH COULD ENHANCE PRECIPITATION ACROSS OUR AREA THURSDAY EVEN WITH A FURTHER OFFSHORE TRACK. WILL NEED TO SEE THE MODELS BECOME STEADY WITH THIS FEATURE BEFORE BUYING INTO IT. SIMILAR METHODS WITH POPS AND QPF AS WITH THE WEDNESDAY PERIOD. A SLOWER MOVING TROUGH OR A STRONGER DISTURBANCE COULD PULL ANY POTENTIAL LOW PRESSURE SYSTEM CLOSER TO THE COAST AND THIS WILL BE WATCHED. HOWEVER THAT POSSIBILITY HAS LITTLE ENSEMBLE SUPPORT FROM BOTH THE ECMWF ENSEMBLE MEAN AND THE GFS ENSEMBLE SUITE AT THIS POINT. THIS SUPPORT HAS INCREASED ON THE RECENT GFS ENSEMBLE PACKAGE. TEMPERATURES WILL BE DEPENDENT ON PRECIPITATION AND CLOUD COVER DID UNDERCUT MOS GUIDANCE IN THE THURSDAY PERIOD GIVEN THE POTENTIAL FOR CLOUDS, PRECIPITATION AND CAA. THURSDAY NIGHT AND FRIDAY: A BREAK AHEAD OF THE NEXT SYSTEM IS LIKELY ON FRIDAY WITH A RETURN TO SOUTHERLY FLOW AND SUNSHINE. THINK THE 12Z GFS IS JUST A BIT TO QUICK BRINGING IN THE NEXT SYSTEM AND WENT WITH A DRY FORECAST. TOOK A MIDDLE GROUND BUT CLOSER TO THE ECMWF WITH REGARDS TO TEMPERATURES. FRIDAY NIGHT THROUGH SATURDAY NIGHT: THE ECMWF BRINGS A CLIPPER SYSTEM FURTHER NORTH PHASING IT INTO A LOW PRESSURE SYSTEM FROM THE SOUTHERN BRANCH LEADING TO A DECENT RAIN/SNOW EVENT. WHILE THE GFS IS COOLER AND WEAKER ONLY BRINGING SCATTERED FLURRIES. ONLY A FEW MEMBERS OF THE ENSEMBLE SUITE SHOWING SOMETHING MORE THAN A CLIPPER. THE UKMET AND CMC ALSO HAVE THERE OWN IDEAS. DID NOT BUY INTO THE OP ECMWF WAA SURGE AHEAD OF THIS SYSTEM AND KEPT TEMPERATURES MORE ALONG THE LINES OF THE MEX AND 12Z GFS. FOR NOW ONLY BROUGHT UP POPS INTO THE LOW CHANCE RANGE GIVEN THE HIGHER DEGREE OF UNCERTAINTY IN THIS PERIOD. SUNDAY AND MONDAY: FAIRLY GOOD AGREEMENT ON MOST WEATHER ELEMENTS IN THIS PERIOD WITH THE MODEL GUIDANCE AND STUCK FAIRLY CLOSE TO WPC. A PERIOD OF CAA ON THE BACKSIDE OF ANY FRONT OR STORM SYSTEM WITH 850 MB TEMPS FALLING BELOW -10C WE MAY STRUGGLE TO REACH FREEZING FROM PHL NW. COUPLED WITH SOME WIND IT SHOULD BE A FAIRLY COLD DAY SUNDAY. WE SHOULD MODERATE MONDAY AHEAD OF THE NEXT FRONTAL SYSTEM. GENERAL OUTLOOK: THE STAIR STEP DOWN TO NEAR SEASONAL AND THEN BELOW SEASONAL TEMPERATURES WILL OCCUR AS A SERIES OF COLD FRONTS MOVE THROUGH THE REGION. OUR OLD FRIEND, THE POLAR VORTEX CURRENTLY IN NORTHWESTERN CANADA IS ABOUT TO TAKE A HIT. AN UPWARD PROPAGATING ROSSBY WAVE IS PREDICTED TO PERTURB AND ELONGATE IT DURING THE LONG TERM PERIOD (AND BEYOND). THIS SHOULD ONCE AGAIN SEND PART OF THE VORTEX INTO NORTHEASTERN CANADA. COUPLED WITH DISTURBANCES CRESTING THE EASTERN PACIFIC RIDGE, THEY WILL ACT IN TANDEM TO BRING COLDER AIR INTO THE FORECAST AREA ONCE AGAIN. THE LATEST ECMWF STRATOSPHERIC MODEL SOLUTION POLAR VORTEX HIT IS SO INTENSE, THIS IS THE FIRST TIME THIS WINTER THAT STRATOSPHERIC WARMING (STRONGER AROUND 10MB FOR NOW) IS PREDICTED TO START. WHETHER IT CAN WORK ITS WAY DOWN INTO THE TROPOSPHERE AND WHERE IT DOES, WOULD HAVE AN IMPACT ON THE NORTHERN HEMISPHERE`S WEATHER AND TELECONNECTION PATTERNS INTO FEBRUARY. BEYOND OUR DETERMINISTIC PERIOD THE WEEK2 TEMPS: THE LINES CONTINUE TO BE DRAWN BETWEEN THE NAEFS (NEAR NORMAL) AND THE ECMWF (DONT ASK). BOTH HAVE BEEN REMAINING IN THEIR RESPECTIVE NORMAL VS COLD CAMPS. HOWEVER BOTH THE GFS AND ECMWF OP RUNS FROM THIS AFTERNOON ARE SHOWING OMINOUS SIGNS THE ARCTIC AIR IS RETURNING TO THE PATTERN. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...VFR FOR AWHILE WITH INCREASING AND GRADUALLY LOWERING CEILINGS. HOWEVER, SOME MVFR CEILINGS SHOULD DEVELOP FROM ABOUT 08Z ONWARD ALONG WITH THE ARRIVAL OF SOME SHOWERS. SOUTH-SOUTHWEST WINDS LESS THAN 10 KNOTS. TUESDAY...MVFR TO IFR CONDITIONS EXPECTED WITH RAIN. IMPROVEMENT DURING THE AFTERNOON. OUTLOOK... TUESDAY NIGHT: CONTINUED IMPROVING TO VFR WITH DECREASING CLOUDS WEDNESDAY THROUGH THURSDAY: MAINLY VFR, SOME RESTRICTIONS TO MVFR IN ANY RAIN OR SNOW SHOWERS. FRIDAY: VFR SATURDAY: LOCAL RESTRICTIONS TO MVFR IN RAIN AND SNOW SHOWERS. && .MARINE... SMALL CRAFT ADVISORY CONTINUES IN PLACE FOR TONIGHT ON ATLANTIC WATERS AND HAS BEEN EXTENDED THROUGH THE DAY THURSDAY BASED ON EXPECTED CONTINUED SEAS OF 5 FEET. A SOUTHERLY FLOW WILL INCREASE TONIGHT AHEAD OF AN APPROACHING COLD FRONT. THE WINDS LOOK MARGINAL REGARDING A SMALL CRAFT ADVISORY, AS GUSTS WILL APPROACH 25 KNOTS ON THE OCEAN, HOWEVER, THE INCREASING SOUTHERLY FLOW WILL ALLOW THE SEAS TO BUILD TONIGHT. SEAS ARE EXPECTED TO BUILD TO 5 FEET IN SOUTHERLY FLOW THIS EVENING AND CONTINUE OVERNIGHT AND INTO THE DAY TUESDAY. THOUGH WINDS WILL DROP OFF DURING THE DAY TUESDAY, SEAS ARE EXPECTED TO REMAIN HIGH ENOUGH TO WARRANT A SMALL CRAFT ADVISORY THROUGH THE DAYTIME HOURS TUESDAY. NO SMALL CRAFT ADVISORY ON THE DELAWARE BAY AS SEAS ARE NOT EXPECTED TO GET TO 5 FEET AND WINDS SHOULD GENERALLY REMAIN BELOW 25 KNOTS. AS A COLD FRONT ARRIVES LATE TONIGHT, SOME RAIN IS EXPECTED TO MOVE IN MAINLY TOWARD DAYBREAK. THERE DOES NOT APPEAR TO BE A SIGNIFICANT SURGE IN THE DEW POINTS TONIGHT, THEREFORE FOG IS NOT ANTICIPATED TO BECOME A CONCERN. OUTLOOK... TUESDAY NIGHT...A LIKELY PERIOD OF SUB SMALL CRAFT ADVISORY CONDITIONS. SEAS MIGHT REMAIN CLOSE ON THE OCEAN. WEDNESDAY AND WEDNESDAY NIGHT...ANOTHER RAMP UP INTO POSSIBLE SMALL CRAFT ADVISORY CRITERIA IN THE SOUTHWEST FLOW PRECEDING THE NEXT COLD FRONT. GREATER CONFIDENCE ON THE OCEAN THAN DELAWARE BAY. THURSDAY THROUGH FRIDAY...A GENERAL SOUTHWEST FLOW IS PREDICTED PRECEDING THE NEXT COLD FRONT. WE MIGHT COME CLOSE TO MEETING SMALL CRAFT ADVISORY CRITERIA AGAIN, WITH HIGHER CONFIDENCE ON THE OCEAN AND ON FRIDAY AS THE COLD FRONT COMES CLOSER BY FRIDAY. SATURDAY: SCA CONDITIONS LIKELY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST TUESDAY FOR ANZ450>455. && $$ SYNOPSIS...GAINES NEAR TERM...SZATKOWSKI SHORT TERM...SZATKOWSKI LONG TERM...GAINES/GIGI AVIATION...GAINES/SZATKOWSKI MARINE...GAINES/GIGI/SZATKOWSKI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
345 PM EST MON JAN 13 2014 .SYNOPSIS... A COLD FRONTAL BOUNDARY LOCATED FROM THE GULF COAST STATES TO THE GREAT LAKES WILL MOVE EAST TONIGHT. LOW PRESSURE WILL DEVELOP ALONG THIS FRONT IN THE SOUTHEASTERN UNITED STATES MOVING INTO THE MID-ATLANTIC REGION BY TUESDAY ACCOMPANYING THE COLD FRONT. ANOTHER COLD FRONTAL BOUNDARY WILL PASS THROUGH THE REGION ON WEDNESDAY. WITH LOW PRESSURE DEVELOPING OFFSHORE WEDNESDAY NIGHT AND THURSDAY. ANOTHER FRONTAL BOUNDARY AND LOW PRESSURE SYSTEM WILL APPROACH THE REGION FOR THE FRIDAY NIGHT AND SATURDAY TIME PERIOD. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... TEMPERATURES THIS EVENING WILL START OFF FAIRLY MILD AND DIURNAL RANGE FOR TONIGHT WILL BE TRIMMED BASED ON INCREASING CLOUD COVER. RAISED TEMPERATURES FOR TONIGHTS LOW BY SEVERAL DEGREES, USING BLEND OF MAV AND RUC GUIDANCE. LAV GUIDANCE WAS USED FOR LATER AFTERNOON PERIOD BLENDING INTO BEGINNING OF THIS TIME PERIOD. PREVIOUS FORECAST TIMING FOR PRECIPITATION ONSET STILL LOOKS GOOD AND WAS LEFT UNCHANGED. DID UPDATE WITH LATEST WPC QPF GUIDANCE. RAINFALL AMOUNTS ARE RELATIVELY LIGHT. GIVEN MILD OVERNIGHT TEMPERATURES, PRECIPITATION FORECAST CONTINUES ALL LIQUID. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... A WET START TO THE DAY THOUGH AMOUNTS STILL LOOKS TO BE RELATIVELY LIGHT. TOTAL QPF AMOUNTS EXPECTED TO BE UNDER A HALF INCH. PRECIPITATION WILL BE OVER WITH PRIOR TO THE END OF THIS TIME PERIOD. BETWEEN CLOUD COVER EARLY AND COLD AIR ADVECTION LATER IN THE DAY, DAYTIME HIGH TEMPERATURES WILL RUN ONLY 8 TO 10 DEGREES OVER PREVIOUS NIGHT MINIMUM. THAT BEING SAID, STILL QUITE MILD TEMPERATURES FOR MID-JANUARY. USED MET/MAV BLEND FOR DAYTIME HIGH TEMPERATURES. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... TUESDAY NIGHT: SHOULD SEE A GRADUAL REDUCTION IN CLOUDS WITH A BRIEF BREAK BEFORE THE NEXT SYSTEM MOVES INTO THE REGION. WESTERLY FLOW MAY TURN QUICKLY TO SOUTHERLY FLOW BY MORNING WITH 850 MB TEMPS ONLY FALLING TO AROUND 0C. DO NOT EXPECT MUCH OF A TEMPERATURE DROP. FAIRLY TIGHT CLUSTER WITH REGARDS TO MODELS IN THIS PERIOD WITH MOST ELEMENTS. WEDNESDAY: THE NEXT FRONTAL BOUNDARY SHOULD BE QUICKLY MOVING INTO THE REGION BY WEDNESDAY AFTERNOON WITH WAA AHEAD OF THE BOUNDARY. A WEAK DISTURBANCE MAY RESULT IN SOME SCATTERED SHOWERS, MAINLY IN THE FORM OF RAIN AHEAD OF THE FRONT TEMPERATURES MAY WARM WELL INTO THE 40`S. IN FACT THE TIMING OF THIS SYSTEM LOOKS SLOWER WHICH KEEPS US ON THE WARM SIDE LONGER RESULTING IN A WARMING TREND FROM PREVIOUS FORECASTS IN THIS PERIOD. DID NOT GO AS HIGH AS THE 12Z MEX- 51 AT PHL BUT DID RAISE TEMPS. QPF SHOULD BE FAIRLY LIGHT WITH THE LACK OF DEEP MOISTURE PRESENT MAINLY USED A 09Z SREF/ 12Z MOS BLEND FOR POPS AND WENT A LITTLE WETTER THAN THE 09Z SREF FOR QPF. WEDNESDAY NIGHT AND THURSDAY: THE PATTERN SHOULD BECOME MORE AMPLIFIED DURING THIS TIME PERIOD. A TREND THAT STARTED WITH YESTERDAY`S 12Z ECMWF. STRONGER DISTURBANCES MARKED WITH INCREASED 500 MB VORTICITY ARE LIKELY TO ROUND THE BEND IN THE AMPLIFYING TROUGH ALLOWING FOR POTENTIAL LOW PRESSURE DEVELOPMENT. THE QUESTION IS DO THEY TRACK CLOSE ENOUGH TO THE COAST TO IMPACT OUR WEATHER? WELL IT LOOKS TO BE A CLOSE MISS AT THIS POINT WITH POTENTIAL FOR SOME ORGANIZATION OF A LOW PRESSURE SYSTEM OFF THE CAROLINA COAST MOVING OUT TO SEA. THE OVERALL PROGRESSIVE NATURE OF THE PATTERN WOULD ALSO SUPPORT THIS. A CHANCE FOR RAIN AND SNOW WOULD OCCUR FOR THE SOUTHERN AND COASTAL SECTIONS OF THE REGION AS CAA MOVES INTO THE REGION WITH THE NORTHERN/ WESTERN REGIONS DRY. A FEATURE OF NOTE WHICH SHOWED UP ON BOTH THE ECMWF AND CMC 12Z RUNS WAS AN INVERTED TROUGH WHICH COULD ENHANCE PRECIPITATION ACROSS OUR AREA THURSDAY EVEN WITH A FURTHER OFFSHORE TRACK. WILL NEED TO SEE THE MODELS BECOME STEADY WITH THIS FEATURE BEFORE BUYING INTO IT. SIMILAR METHODS WITH POPS AND QPF AS WITH THE WEDNESDAY PERIOD. A SLOWER MOVING TROUGH OR A STRONGER DISTURBANCE COULD PULL ANY POTENTIAL LOW PRESSURE SYSTEM CLOSER TO THE COAST AND THIS WILL BE WATCHED. HOWEVER THAT POSSIBILITY HAS LITTLE ENSEMBLE SUPPORT FROM BOTH THE ECMWF ENSEMBLE MEAN AND THE GFS ENSEMBLE SUITE AT THIS POINT. THIS SUPPORT HAS INCREASED ON THE RECENT GFS ENSEMBLE PACKAGE. TEMPERATURES WILL BE DEPENDENT ON PRECIPITATION AND CLOUD COVER DID UNDERCUT MOS GUIDANCE IN THE THURSDAY PERIOD GIVEN THE POTENTIAL FOR CLOUDS, PRECIPITATION AND CAA. THURSDAY NIGHT AND FRIDAY: A BREAK AHEAD OF THE NEXT SYSTEM IS LIKELY ON FRIDAY WITH A RETURN TO SOUTHERLY FLOW AND SUNSHINE. THINK THE 12Z GFS IS JUST A BIT TO QUICK BRINGING IN THE NEXT SYSTEM AND WENT WITH A DRY FORECAST. TOOK A MIDDLE GROUND BUT CLOSER TO THE ECMWF WITH REGARDS TO TEMPERATURES. FRIDAY NIGHT THROUGH SATURDAY NIGHT: THE ECMWF BRINGS A CLIPPER SYSTEM FURTHER NORTH PHASING IT INTO A LOW PRESSURE SYSTEM FROM THE SOUTHERN BRANCH LEADING TO A DECENT RAIN/SNOW EVENT. WHILE THE GFS IS COOLER AND WEAKER ONLY BRINGING SCATTERED FLURRIES. ONLY A FEW MEMBERS OF THE ENSEMBLE SUITE SHOWING SOMETHING MORE THAN A CLIPPER. THE UKMET AND CMC ALSO HAVE THERE OWN IDEAS. DID NOT BUY INTO THE OP ECMWF WAA SURGE AHEAD OF THIS SYSTEM AND KEPT TEMPERATURES MORE ALONG THE LINES OF THE MEX AND 12Z GFS. FOR NOW ONLY BROUGHT UP POPS INTO THE LOW CHANCE RANGE GIVEN THE HIGHER DEGREE OF UNCERTAINTY IN THIS PERIOD. SUNDAY AND MONDAY: FAIRLY GOOD AGREEMENT ON MOST WEATHER ELEMENTS IN THIS PERIOD WITH THE MODEL GUIDANCE AND STUCK FAIRLY CLOSE TO WPC. A PERIOD OF CAA ON THE BACKSIDE OF ANY FRONT OR STORM SYSTEM WITH 850 MB TEMPS FALLING BELOW -10C WE MAY STRUGGLE TO REACH FREEZING FROM PHL NW. COUPLED WITH SOME WIND IT SHOULD BE A FAIRLY COLD DAY SUNDAY. WE SHOULD MODERATE MONDAY AHEAD OF THE NEXT FRONTAL SYSTEM. GENERAL OUTLOOK: THE STAIR STEP DOWN TO NEAR SEASONAL AND THEN BELOW SEASONAL TEMPERATURES WILL OCCUR AS A SERIES OF COLD FRONTS MOVE THROUGH THE REGION. OUR OLD FRIEND, THE POLAR VORTEX CURRENTLY IN NORTHWESTERN CANADA IS ABOUT TO TAKE A HIT. AN UPWARD PROPAGATING ROSSBY WAVE IS PREDICTED TO PERTURB AND ELONGATE IT DURING THE LONG TERM PERIOD (AND BEYOND). THIS SHOULD ONCE AGAIN SEND PART OF THE VORTEX INTO NORTHEASTERN CANADA. COUPLED WITH DISTURBANCES CRESTING THE EASTERN PACIFIC RIDGE, THEY WILL ACT IN TANDEM TO BRING COLDER AIR INTO THE FORECAST AREA ONCE AGAIN. THE LATEST ECMWF STRATOSPHERIC MODEL SOLUTION POLAR VORTEX HIT IS SO INTENSE, THIS IS THE FIRST TIME THIS WINTER THAT STRATOSPHERIC WARMING (STRONGER AROUND 10MB FOR NOW) IS PREDICTED TO START. WHETHER IT CAN WORK ITS WAY DOWN INTO THE TROPOSPHERE AND WHERE IT DOES, WOULD HAVE AN IMPACT ON THE NORTHERN HEMISPHERE`S WEATHER AND TELECONNECTION PATTERNS INTO FEBRUARY. BEYOND OUR DETERMINISTIC PERIOD THE WEEK2 TEMPS: THE LINES CONTINUE TO BE DRAWN BETWEEN THE NAEFS (NEAR NORMAL) AND THE ECMWF (DONT ASK). BOTH HAVE BEEN REMAINING IN THEIR RESPECTIVE NORMAL VS COLD CAMPS. HOWEVER BOTH THE GFS AND ECMWF OP RUNS FROM THIS AFTERNOON ARE SHOWING OMINOUS SIGNS THE ARCTIC AIR IS RETURNING TO THE PATTERN. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...VFR FOR AWHILE WITH INCREASING AND GRADUALLY LOWERING CEILINGS. HOWEVER, SOME MVFR CEILINGS SHOULD DEVELOP FROM ABOUT 08Z ONWARD ALONG WITH THE ARRIVAL OF SOME SHOWERS. SOUTH-SOUTHWEST WINDS LESS THAN 10 KNOTS. TUESDAY...MVFR TO IFR CONDITIONS EXPECTED WITH RAIN. IMPROVEMENT DURING THE AFTERNOON. OUTLOOK... TUESDAY NIGHT: CONTINUED IMPROVING TO VFR WITH DECREASING CLOUDS WEDNESDAY THROUGH THURSDAY: MAINLY VFR, SOME RESTRICTIONS TO MVFR IN ANY RAIN OR SNOW SHOWERS. FRIDAY: VFR && .MARINE... SMALL CRAFT ADVISORY CONTINUES IN PLACE FOR TONIGHT ON ATLANTIC WATERS AND HAS BEEN EXTENDED THROUGH THE DAY THURSDAY BASED ON EXPECTED CONTINUED SEAS OF 5 FEET. A SOUTHERLY FLOW WILL INCREASE TONIGHT AHEAD OF AN APPROACHING COLD FRONT. THE WINDS LOOK MARGINAL REGARDING A SMALL CRAFT ADVISORY, AS GUSTS WILL APPROACH 25 KNOTS ON THE OCEAN, HOWEVER, THE INCREASING SOUTHERLY FLOW WILL ALLOW THE SEAS TO BUILD TONIGHT. SEAS ARE EXPECTED TO BUILD TO 5 FEET IN SOUTHERLY FLOW THIS EVENING AND CONTINUE OVERNIGHT AND INTO THE DAY TUESDAY. THOUGH WINDS WILL DROP OFF DURING THE DAY TUESDAY, SEAS ARE EXPECTED TO REMAIN HIGH ENOUGH TO WARRANT A SMALL CRAFT ADVISORY THROUGH THE DAYTIME HOURS TUESDAY. NO SMALL CRAFT ADVISORY ON THE DELAWARE BAY AS SEAS ARE NOT EXPECTED TO GET TO 5 FEET AND WINDS SHOULD GENERALLY REMAIN BELOW 25 KNOTS. AS A COLD FRONT ARRIVES LATE TONIGHT, SOME RAIN IS EXPECTED TO MOVE IN MAINLY TOWARD DAYBREAK. THERE DOES NOT APPEAR TO BE A SIGNIFICANT SURGE IN THE DEW POINTS TONIGHT, THEREFORE FOG IS NOT ANTICIPATED TO BECOME A CONCERN. OUTLOOK... TUESDAY NIGHT...A LIKELY PERIOD OF SUB SMALL CRAFT ADVISORY CONDITIONS. SEAS MIGHT REMAIN CLOSE ON THE OCEAN. WEDNESDAY AND WEDNESDAY NIGHT...ANOTHER RAMP UP INTO POSSIBLE SMALL CRAFT ADVISORY CRITERIA IN THE SOUTHWEST FLOW PRECEDING THE NEXT COLD FRONT. GREATER CONFIDENCE ON THE OCEAN THAN DELAWARE BAY. THURSDAY THROUGH FRIDAY...A GENERAL SOUTHWEST FLOW IS PREDICTED PRECEDING THE NEXT COLD FRONT. WE MIGHT COME CLOSE TO MEETING SMALL CRAFT ADVISORY CRITERIA AGAIN, WITH HIGHER CONFIDENCE ON THE OCEAN AND ON FRIDAY AS THE COLD FRONT COMES CLOSER BY FRIDAY. SATURDAY: SCA CONDITIONS LIKELY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST TUESDAY FOR ANZ450>455. && $$ SYNOPSIS...GAINES NEAR TERM...SZATKOWSKI SHORT TERM...SZATKOWSKI LONG TERM...GAINES/GIGI AVIATION...GAINES/SZATKOWSKI MARINE...GAINES/GIGI/SZATKOWSKI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
355 PM EST MON JAN 13 2014 .DISCUSSION... CURRENTLY... HIGH PRES RIDGE CENTERED OFF THE CAROLINA COAST COMBINING WITH A SHORT WAVE FRONTAL TROF PUSHING ACRS THE MS VALLEY/WRN GOMEX TO GENERATE A DEEP SRLY FLOW ACRS THE FL PENINSULA. WINDS HAVE EFFECTIVELY MODIFIED THE LCL AIRMASS BLO H85 WITH AFTN SFC DEWPOINTS IN THE U50S/L60S...UP FROM THE M/U40S AROUND DAYBREAK THIS MORNING. HOWEVER...VSBL SAT PICS INDICATE THE DRY AIR PERSISTS IN THE MID LVLS AS ONLY FAIR WX STRATOCU AND UPR LVL CONVECTIVE DEBRIS CLOUDS ARE PRESENT OVERHEAD. RUC ANALYSIS CONFIRMS THIS WITH H85-H50 MEAN RH READINGS BLO 20PCT. UPSTREAM...PREFRONTAL CONVECTIVE LINE OVER THE DEEP SOUTH IS TRYING TO DVLP INTO THE CENTRAL THE CENTRAL GOMEX...AIDED BY DIFFLUENT UPR LVL FLOW OVER THE DEEP SOUTH AND A LIFTING H30-H20 JETSTREAK OVER THE LOWER MS VALLEY THAT IS GENERATING STRONG H30-H20 DIVERGENCE. RUC ANALYSIS SHOWING A PAIR OF MID LVL VORT MAXES HELPING TO IGNITE CONVECTION OVER THE ERN GOMEX...BOTH OF WHICH ARE EMBEDDED WITHIN DEEP SW FLOW. LOW LVL MOISTURE IS PLENTIFUL OVER THE GOMEX WITH H100-H85 MEAN RH LARGELY AOA 80PCT...AND AOA 50PCT THRU THE H85-H50 LYR. RESPECTABLE MID LVL LAPSE RATES BTWN 6.5-7.0C/KM THRU THE H70-H50 LYR...THOUGH H85-H70 LAPSE RATES AOB 5.0C/KM ARE MUCH SHALLOWER. TONIGHT... ELEMENTS ARE IN PLACE FOR ANOTHER RAIN EVENT FOR CENTRAL FL OVERNIGHT. WHILE THE DRY AIR AND WEAK LAPSE RATES OVERHEAD WILL REQUIRE SOME TIME TO FULLY ERODE...THERE IS SUFFICIENT MOISTURE AND MID/UPR LVL DYNAMIC SUPPORT FOR THE CONVECTIVE LINE TO MAKE ITS WAY INTO THE I-4 CORRIDOR LATE THIS EVNG...THEN SOUTH OF THE CORRIDOR AFTERWARD. MID LVL RIDGE AXIS CENTERED NE OF THE BAHAMAS WILL APPLY SOME BREAKING ACTION TO THE LINE AS IT PUSHES INTO THE CENTRAL PENINSULA...RESULTING IN A RATHER TIGHT POP GRADIENT ACRS THE CWA: 60-70PCT FROM OSCEOLA/NRN BREVARD NWD...30PCT ARND THE LAKE OKEECHOBEE REGION. WIND GUSTS ARND 40KTS PSBL WITH SOME STORMS... THOUGH THE LIFTING NATURE OF THE PRIMARY JET STREAK AND THE POSITIVE TILT OF THE FRONTAL TROF AXIS ARE NOT CONDUCIVE TO LARGE OUTBREAKS OF STRONG/SVR TSRAS. DEEP S/SW FLOW COUPLED WITH INCREASING CLOUD COVER WILL KEEP MIN TEMPS 15-20F ABV AVG...L/M60S INTERIOR...MU60S ALONG THE COAST. TUESDAY... A 130KT JET STREAK DIGGING OVER WRN CANADA WILL DRIVE A SURFACE LOW OUT OF THE NRN PLAINS THAT WILL REINFORCE THE LOW N OF THE GREAT LAKES. WHILE THIS WILL PROVIDE ADDITIONAL PUSH TO THE COLD FRONT... THE BLOCKING RIDGE NW OF THE BAHAMAS IS WELL REMOVED FROM THE JET CORE AND WILL NOT GIVE UP ITS CURRENT POSITION EASILY. WHILE THE FRONT MAKE STEADY PROGRESS THROUGH THE PENINSULA...BOTH GFS/ECMWF INDICATE THE FRONT HANGING UP OVER THE LAKE OKEECHOBEE REGION THROUGH THE AFTERNOON HOURS. FORECAST WILL REFLECT THE SLOWER SOLUTION WITH 50-60POPS FROM INDIAN RIVER/OKEECHOBEE COUNTY NWD...40/50POPS TO THE SOUTH...WITH A SLGT CHC OF TSRAS IN THE FCST THRU MIDDAY. THE H85-H50 TROF TRAILS WELL BEHIND THE LOW LVL TROF AND WILL MAINTAIN A DEEP MID LVL SW FLOW THAT WILL GRADUALLY PUSH THE BEST DYNAMIC SUPPORT OUT OF THE AREA. PRECIP SHOULD DECREASE THRU THE AFTN WITH THE WEAKENING LIFT. DESPITE CLOUDY SKIES AND RAIN...PREVAILING SWRLY FLOW WILL GENERATE WEAK WARM AIR ADVECTION...KEEPING MAX TEMPS IN THE M/U70S OVER MOST OF THE CWA. TUESDAY NIGHT... MODELS HAVE TRENDED SLOWER SCOURING OUT LOW LVL MOISTURE BEHIND THE FRONT AND NOW APPEARS A BAND OF POST FRONTAL CLOUDINESS WILL LINGER ACROSS SE SECTIONS THROUGH MUCH OF THE NIGHT WITH A SLIGHT CHANCE FOR SHOWERS. EXPECT SOME CLEARING ACROSS THE NORTH WITH LOWS IN THE UPPER 40S TO LOWER 50 THERE AND MID TO UPPER 50S ACROSS FAR SRN SECTIONS. WEDNESDAY... STRONGER S/W TROUGH WILL DIG TWD THE SRN APPALACHIANS AND INDUCE LOW PRESSURE DEVELOPMENT NEAR THE MID ATLC. WNW LOW LVL WINDS WILL INCREASE BY AFTERNOON WITH BREEZY CONDITIONS DEVELOPING NRN PORTIONS OF E CENTRAL FL. POST FRONTAL CLOUDINESS SHOULD EXIT MARTIN COUNTY IN THE MORNING WITH MOSTLY SKIES. HAVE LEANED TOWARD WARMER GFS GUID FOR NOW WITH HIGHS IN THE UPPER 60S NORTH AND AROUND 70 SOUTH. WEDNESDAY NIGHT... BREEZY NW WINDS IN THE EVENING WILL DROP TO 10-15 MPH NEAR THE COAST AND NEAR 10 MPH INLAND OVERNIGHT. OVERNIGHT LOWS FORECAST TO DROP TO BETWEEN 35 AND 40. LATE NIGHT WIND CHILLS WILL DROP INTO THE UPPER 20S TO LOWER 30S WHICH MAY REQUIRE A WIND CHILL ADVISORY. EXTENDED... 12Z GUIDANCE STILL INDICATING COOLER TEMPERATURES FOR MID TO LATE WEEK WITH SEVERAL REINFORCING DRY FRONTS EXPECTED. MADE SOME SLIGHT ADJUSTMENTS TO TEMPS BASED ON LATEST GUIDANCE WITH COLDEST NIGHT STILL LOOKING TO BE THU NIGHT/EARLY FRIDAY MORNING WITH THREAT OF FROST ACROSS PORTIONS OF E CENTRAL FL...ESPEC FOR THE INTERIOR. WED-SAT...(PREV DISC) A VERY PROGRESSIVE PATTERN WILL BE IN PLACE ACROSS THE CONUS FOR THE LATTER HALF OF THE WEEK WITH SEVERAL SHARP TROUGHS DROPPING INTO THE CENTRAL US AND SWINGING THROUGH THE EASTERN SEABOARD. FIRST TROUGH SWINGS THROUGH ON WEDNESDAY...DRIVING CYCLOGENESIS OFF THE CAROLINA COAST AND BRINGING THROUGH A REINFORCING SURFACE FRONT THAT IS EXPECTED TO REMAIN DRY FOR THE REGION MARKED BY AN INCREASE IN CLOUD COVER. THE NEXT FRONT SWINGS THROUGH FRI NIGHT/SAT...BUT MODELS ARE NOT CURRENTLY TO EXCITED ABOUT RAIN CHANCES SO WILL KEEP FORECAST DRY FOR NOW. THE NET EFFECT FOR CENTRAL FLORIDA WILL BE A PERIOD OF COOL AND MOSTLY DRY WEATHER WITH BREEZY WEST-NORTHWEST BEHIND EACH FRONT. DAYTIME HIGHS WILL BE IN THE MID-UPPER 60S WITH LOW 70S ACROSS THE TREASURE COAST AND OKEECHOBEE COUNTY ON WEDNESDAY AND FRIDAY. THURSDAY WILL BE THE COLDEST OF THE WEEK BEHIND THE NEXT FRONT WITH HIGH TEMPS IN THE MID-UPPER 50S. SATURDAY WILL BE ANOTHER COOL DAY BEHIND THE NEXT FRONT WITH HIGHS GENERALLY IN THE UPPER 50S AND LOW 60S...THOUGH THE TREASURE COAST WILL REMAIN IN THE MID 60S. OVERNIGHT LOWS WILL BE THE MAIN CONCERN IN THE EXTENDED WITH LOWS FORECAST TO DROP INTO THE MID-UPPER 30S WED NIGHT. WIND CHILLS OF 30 TO 35 DEGREES WILL BE A CONCERN AS THE CURRENT FORECAST HAS WINDS AROUND 10 MPH. THURSDAY NIGHT LOOKS TO BE THE COLDEST OF THE WEEK WITH HIGH CENTER DIRECTLY OVERHEAD THURS NIGHT AND MOSTLY CLEAR SKIES LEADING TO EXCELLENT RADIATIONAL COOLING CONDITIONS. HIGH TEMPERATURES IN THE LOW-MID 30S AREA WIDE WITH WIDESPREAD FROST POSSIBLE UNDER CALM WINDS. WITH THE NEXT FRONT COMING THROUGH ON FRI NIGHT...TEMPERATURES DO NOT LOOK AS COLD INTO THE UPPER 30S. GUIDANCE HAS BEEN TRENDING LOWER WITH TEMPERATURES IN THE EXTENDED...AND IT POSSIBLE THAT FREEZING TEMPERATURES WILL BECOME A CONCERN WED NIGHT AS WELL. && .AVIATION... THRU 14/03Z...VFR/SRLY SFC WNDS AOB 12KTS ALL SITES...CIGS AOA FL120. BTWN 14/03Z-14/09Z...N OF KEVB-KISM S/SW SFC WNDS BLO 10KTS CIGS BTWN FL040-060 WITH NMRS MVFR SHRAS/ISOLD IFR TSRAS...S OF KEVB-KISM S SFC WNDS BLO 10KTS CIGS BTWN FL060-080 WITH CHC MVFR SHRAS/SLGT CHC IFR TSRAS. BTWN 14/09Z-14/18Z...N OF KVRB-KOBE SW SFC WNDS BLO 10KTS MVFR CIGS BTWN FL010-020 WITH NMRS MVFR SHRAS/ISOLD IFR TSRAS...S OF KVRB-KOBE S/SW SFC WNDS BLO 10KTS MVFR CIGS BTWN FL020-030 WITH CHC MVFR SHRAS/SLGT CHC IFR TSRAS. && .MARINE... TONIGHT...SFC/BNDRY LYR WINDS WILL STRENGTHEN TO A MODERATE TO FRESH S/SW BREEZE AS AN ADVANCING FRONTAL TROF OVER THE GOMEX INTERACTS WITH A RETREATING RIDGE OVER THE W ATLC. WINDS SPEEDS WILL REQUIRE A CAUTIONARY STATEMENT FOR THE OFFSHORE WATERS N OF SEBASTIAN INLET THOUGH THE OFFSHORE COMPONENT WILL LIMIT SEA HEIGHTS TO 2-4FT NEARSHORE AND 3-5FT OFFSHORE. SCT/NMRS SHRAS AND ISOLD TSRAS N OF SEBASTIAN INLET AFT MIDNIGHT...ADVANCING S OF THE INLET IN THE PREDAWN HRS. TUESDAY...MODERATE TO FRESH W/SW BREEZE BCMG NW AND DIMINISHING THRU THE DAY AS A COLD FRONT PUSHES THROUGH CENTRAL FL. OFFSHORE COMPONENT WILL CONTINUE TO LIMIT TOTAL SEA HEIGHTS TO 2-4FT NEARSHORE AND 3-5FT OFFSHORE...UP TO 6FT IN THE GULFSTREAM N OF SEBASTIAN INLET WHERE WIND SPEEDS WILL BE SLIGHTLY STRONGER. SHRAS LIKELY WITH ISOLD TSRAS THRU MIDDAY...DECREASING THROUGH THE AFTN. WED-SAT...NW WINDS EXPECTED AROUND 10-15 KNOTS TUE NIGHT BEHIND THE FRONT THEN INCREASING TO 15-20 KNOTS OFFSHORE WED AFTN AND NEAR GALE CONDITIONS FOR THE OFFSHORE WATERS WED NIGHT. THIS WILL BUILD SEAS RAPIDLY WED NIGHT INTO EARLY THU CREATING VERY HAZARDOUS CONDITION FOR SMALL CRAFT ON THE OPEN ATLANTIC. WINDS DECREASE THU AFTN/THU NIGHT WITH SEAS DROPPING BELOW ADVISORY LEVELS THU NIGHT. && .PRELIMINARY POINT TEMPS/POPS... DAB 64 74 47 68 / 70 60 10 10 MCO 63 76 51 69 / 70 60 10 10 MLB 67 76 55 70 / 50 60 20 10 VRB 67 77 56 70 / 40 50 20 10 LEE 63 74 48 69 / 70 60 10 10 SFB 64 76 50 69 / 70 60 10 10 ORL 64 76 52 69 / 70 60 10 10 FPR 67 78 57 70 / 30 40 20 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM/AVIATION...BRAGAW LONG TERM/IMPACT WX...VOLKMER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
340 PM EST MON JAN 13 2014 .SYNOPSIS... 19Z WATER VAPOR AND H4 RAP ANALYSIS SHOW AN AMPLIFIED UPPER LEVEL PATTERN OVER THE CONUS HIGHLIGHTED BY A LARGE PROGRESSIVE LONGWAVE TROUGH OVER THE CENTRAL PLAINS/MS VALLEY. A SHORTWAVE CAN BEEN SEEN EJECTING EASTWARD OVER THE NORTHERN GULF OF MEXICO AROUND THE BASE OF THE MAIN LONGWAVE TROUGH. THE UPPER LEVEL PV ANOMALY SWINGING ACROSS EASTERN TEXAS COMBINED WITH FAVORABLE RRQ DYNAMICS FROM ITS ASSOCIATED JET STREAK IS FORCING A WEAK FRONTAL WAVE NEAR THE SURFACE ALONG THE LA COAST. LONGWAVE RIDGING IS SEEN ON EITHER SIDE OF THIS TROUGH OVER BOTH COASTS. THE EASTERN U.S. RIDGE EXTENDS DOWN TO THE FLORIDA PENINSULA...BUT IS BEGINNING TO EXIT OVER THE WESTERN ATLANTIC. WV IMAGERY SHOWS A PLUME OF SOUTHERN STREAM UPPER LEVEL MOISTURE IS BEGINNING TO OVERRIDE THE PENINSULA AHEAD OF THE APPROACHING TROUGH...HOWEVER A LOOK AT THE 13/12Z KTBW SOUNDING PROFILE SHOWS THAT THE MID/LOWER LEVELS WERE STILL VERY DRY THIS MORNING WITH IMPRESSIVE DEWPOINT DEPRESSIONS OF 40-45C BELOW 500MB. WE WILL STILL NEED SOME TIME TO MOISTEN THIS LOWER COLUMN BEFORE WE CAN START TALKING ABOUT ANY SHOWER ACTIVITY FOR OUR REGION. AT THE SURFACE NEARBY...HIGH PRESSURE IS NOW CENTERED OFF THE GA/CAROLINA COAST PROVIDING A WEAK EASTERLY TO SOUTHEASTERLY FLOW ACROSS THE PENINSULA. REGIONAL RADARS SHOW A LARGE CLUSTER OF SHOWERS AND STORMS PROGRESSING EASTWARD ACROSS THE FLORIDA PANHANDLE AND EASTERN GULF. THIS ACTIVITY WILL BE APPROACHING THE NATURE COAST ZONES LATER ON THIS EVENING. && .SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)... TONIGHT...UPPER TROUGH AND ASSOCIATED WEAK HEIGHT FALLS/DCVA/ Q-VECTOR CONVERGENCE AND RRQ JET DYNAMICS WILL OVERSPREAD THE REGION WITH TIME...MAXIMIZING THEIR COMBINED EFFECTS OVER THE NORTHERN HALF OF THE PENINSULA. A CLUSTER OF SHOWER AND A FEW EMBEDDED THUNDERSTORMS IS EXPECTED TO MOVE INTO THE NATURE COAST THIS EVENING...MAINLY AFTER DARK. THERE LOOKS TO BE A TIGHT GRADIENT IN THE RAIN CHANCES FROM MID EVENING THROUGH MIDNIGHT RANGING FROM CATEGORICAL > 80% AROUND LEVY/CITRUS COUNTY...RANGING DOWN TO ONLY 40-60%% FOR THE I-4 CORRIDOR...AND THEN 20% SLIGHT CHANCE OR LESS SOUTH AND EAST OF SARASOTA. THE FRONTAL WAVE WILL PIVOT UP INTO THE CAROLINAS AFTER MIDNIGHT WITH THE COLD FRONT APPROACHING THE WEST COAST OF FLORIDA. HIGHER RAIN CHANCES SHOULD EXPAND SOUTH TO THE TAMPA BAY AREA FOR THE SECOND HALF OF THE NIGHT WITH THE TIGHTER POP GRADIENT SHIFTING TO OUR SOUTHERN ZONES. 80% OR GREATER ALONG THE I-4 CORRIDOR NORTHWARD...AND 30-40% DOWN TOWARD FORT MYERS. RETURN FLOW AHEAD OF THIS SYSTEM WILL BE MEAGER AT BEST AND HENCE SURFACE BASED INSTABILITY WILL BE VERY WEAK. PROB WILL SEE A FEW UPDRAFTS CAPABLE OF SUPPORTING THUNDERSTORMS BASED ON THE DEGREE OF SYNOPTIC FORCING...HOWEVER THE THREAT FOR ANY SEVERE WEATHER IS ON THE LOWER SIDE. TUESDAY/TUESDAY NIGHT... THE WEAK COLD SLOWLY SAGS THROUGH THE PENINSULA DURING THE DAY. AS THE SHORTWAVE SHEARS OUT TO THE NORTHEAST...THE OVERALL SYNOPTIC FORCING/Q-VECTOR CONVERGENCE WEAKENS WITH TIME. THERE WILL STILL BE A BROAD AREA OF WEAK SYNOPTIC FORCING OVERHEAD WITHIN THE GENERAL CYCLONIC CIRCULATION OF THE UPPER TROUGH...HOWEVER ANY SHOWER ACTIVITY WILL MOST DIRECTLY BE ATTRIBUTED TO THE LOW LEVEL FOCUS ALONG/AHEAD OF THE FRONT. THIS FOCUS WILL ALSO BE WEAKENING WITH TIME AS THE FRONT IS STRETCHED AND SLOWS. WITH ALL THIS IN MIND...EXPECT THE CLUSTERS OF SHOWERS TO BECOME LESS ORGANIZED THROUGH THE DAY WITH THE BETTER CHANCES SHIFTING SOUTH FROM THE I-4 CORRIDOR DURING THE MORNING...TO OUR SOUTHERN ZONES BY AFTERNOON. SHOULD ACTUALLY SEE THE RAIN CHANCES END FOR MUCH OF THE NATURE COAST BY THE SECOND HALF OF THE DAY. TUESDAY NIGHT...THE EASTERN U.S. UPPER TROUGH IS RE-ENFORCED/SHARPENED ONCE AGAIN BY STRONG SHORTWAVE ENERGY DROPPING OUT OF THE UPPER MS VALLEY. ALTHOUGH MUCH OF THE FORECAST AREA WILL BE TOO DRY FOR THE DYNAMICS ASSOCIATED WITH THIS NEW AMPLIFICATION TO SUPPORT RAIN...THERE MAY BE JUST ENOUGH COLUMN MOISTURE STILL LEFT OVER DOWN TOWARD CHARLOTTE/LEE COUNTY FOR THE NEWLY ARRIVING SYNOPTIC LIFT TO GET A FEW SHOWERS GOING ONCE AGAIN. WILL KEEP A LEAST A SLIGHT CHANCE POP IN THE FORECAST FOR THESE ZONES. WEDNESDAY... A SECONDARY AND MUCH STRONGER COLD FRONT WILL LEAD THIS NEXT POWERFUL TROUGH INTO THE SOUTHEAST CONUS. WITH LITTLE MOISTURE TO WORK WITH...THIS FRONT WILL HAVE A MOSTLY DRY PASSAGE...BUT LOOKS TO DELIVER ONE OF (IF NOT THE) COLDEST AIRMASS OF THE SEASON SO FAR TO PORTIONS OF THE FLORIDA PENINSULA. WEDNESDAY DURING THE DAY WILL LIKELY NOT FEEL THAT COLD...HOWEVER...ONCE THE SUN BEGINS TO SET WEDNESDAY EVENING...THE COLD AIR WILL CERTAINLY BEGIN TO BE FELT. 850MB TEMPERATURES PLUMMET BEHIND THIS FRONT DOWN TO 0C OR BELOW FOR MUCH OF THE FORECAST AREA...EVEN AS LOW AS -6C FOR THE NORTHERN NATURE COAST. THOSE TYPES OF READING ARE AROUND 3.5 STANDARD DEVIATIONS BELOW CLIMO. EVEN THOUGH NO ORGANIZED SHOWERS ARE EXPECTED WITH THE FRONTAL PASSAGE...THE RAPID CAA ABOVE THE RELATIVELY WARM WATERS OF THE EASTERN GULF SHOULD BE SUFFICIENT TO FORCE SOME OCEAN EFFECT/INSTABILITY SPRINKLES...AND CERTAINLY LOWER STRATUS OFF THE GULF INTO THE COASTAL ZONES. THIS IS ESPECIALLY LIKELY IF YOU ADD/CONSIDER THE SYNOPTIC INFLUENCE OF A VERY STRONG SHORTWAVE IMPULSE WHICH WILL BE CROSSING THE REGION LATER WED AND FIRST HALF OF WED NIGHT. THESE SPRINKLES SHOULD DIMINISH AFTER WEDNESDAY EVENING AS THE SHORTWAVE AXIS PASSES BY. TEMPERATURES AT THE SURFACE WEDNESDAY NIGHT ARE FORECAST TO DROP TO OR BELOW FREEZING WEDNESDAY NIGHT FROM PARTS OF INLAND PASCO/HERNANDO COUNTIES AND NORTHWARD...BUT WIND CHILL ISSUES ARE EXPECTED FOR JUST ABOUT THE ENTIRE FORECAST AREA THROUGH EARLY THURSDAY MORNING. THOSE WITH AGRICULTURAL OR OUTDOOR ACTIVITIES PLANNED FOR WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS URGED TO KEEP UP WITH THE LATEST FORECASTS CONCERNING THIS NEXT UPCOMING COLD AIR EVENT. && .LONG TERM (THURSDAY THROUGH SUNDAY)... THE LONG TERM FORECAST PERIOD BEGINS AFTER FRONTAL PASSAGE LATE WEDNESDAY INTO EARLY THURSDAY. A 500 MB TROUGH SWINGS THROUGH FLORIDA BY 12Z THURSDAY...WITH HIGH PRESSURE BUILDING IN AT THE SURFACE FROM THE GULF. DRIER...COOLER AIR WILL BE ABLE TO ADVECT INTO WEST CENTRAL AND SOUTHWEST FLORIDA FROM WELL NORTH ON THE CONTINENT. A WEAKER FRONTAL BOUNDARY WILL MOVE THROUGH FLORIDA ON FRIDAY NIGHT INTO SATURDAY...FALLING APART OVER SOUTHERN FLORIDA BY THE END OF SATURDAY. ONCE AGAIN...HIGH PRESSURE BUILDS IN AND DOMINATES AREA WEATHER TO END THE EXTENDED. WHILE MODEL GUIDANCE IS SOMEWHAT CONSISTENT ON THE TIMING OF THE SYNOPTIC SCALE FEATURES...THERE IS SOME DIFFERENCE IN SOLUTIONS FOR HOW COLD WEST CENTRAL AND SOUTHWEST FLORIDA WILL ACTUALLY GET. PREVIOUS FORECAST PHILOSOPHY OF BLENDING SEVERAL GUIDANCE MEMBERS WILL LIKELY VERIFY BETTER THAN STICKING WITH A SINGLE GUIDANCE SOLUTION. EITHER WAY...THE POTENTIAL FOR A FREEZE EVENT FOR MUCH OF WEST CENTRAL FLORIDA REMAINS LATER IN THE WEEK. THE LACK OF MOISTURE WILL LIMIT RAIN CHANCES WITH THE SECOND...WEAKER FRONT AND PREVENT THE AIRMASS OVER THE AREA FROM MODERATING VERY MUCH HEADING INTO THE WEEKEND. && .AVIATION... 13/18Z-14/18Z: VFR PREVAILS INTO EARLY EVENING WITH SCT-BKN CIGS ABOVE 3000FT FOR THE MOST PART AND SOUTHERLY WINDS WITH OCNL GUSTS. CONDITIONS BEGIN TO DETERIORATE IN THE EVENING WITH VCNTY SHRA AND TSRA... ALTHOUGH BELIEVE TSRA MAY BE RATHER LIMITED. HAVE TEMPO MVFR LATE NIGHT FOR CIGS WITH SHRA/BR NORTH AND BR SOUTH. MVFR CIG WITH VCSH CONTINUE AFTER DAYBREAK IN THE NORTH AND SPREADS TO THE SOUTH. && .MARINE... A COLD FRONT APPROACHING THE AREA WILL SLIDE SOUTHWARD THROUGH THE WATERS ON TUESDAY...AND WINDS MAY REACH CAUTIONARY LEVELS ACROSS PORTIONS OF THE MARINE AREA. A RE-ENFORCING COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY NIGHT AND MOVE THROUGH THE AREA ON WEDNESDAY. AT THAT TIME...WINDS ARE EXPECTED TO PICK UP IN ADVANCE OF THE FRONT LATE TUESDAY NIGHT...WITH STRONG WINDS THEN CONTINUING THROUGH THURSDAY MORNING. AT THIS TIME...SMALL CRAFT ADVISORY HEADLINES APPEAR LIKELY WEDNESDAY AND WEDNESDAY NIGHT FOR MOST IF NOT ALL WATERS. && .FIRE WEATHER... A WEAK COLD FRONT WILL APPROACH AND CROSS THE REGION LATER TONIGHT AND TUESDAY WITH A BAND OF SHOWERS AND STORMS. A STRONGER SECONDARY BUT GENERALLY DRY FRONT WILL CROSS THE AREA ON WEDNESDAY. SOME INLAND AREAS ON WEDNESDAY MAY BRIEFLY APPROACH CRITICAL LEVELS OF RELATIVE HUMIDITY BUT RED FLAG CONDITIONS ARE CURRENTLY NOT ANTICIPATED. A MUCH DRIER AND COLDER AIRMASS WILL THEN DESCEND ON THE REGION FOR THE END OF THE WEEK. FOG POTENTIAL...AREAS OF LOW CLOUDS AND PATCHY FOG WILL BE POSSIBLE TONIGHT. LITTLE IN THE WAY OF FOG FORMATION IS THEN EXPECTED FOR TUESDAY NIGHT. && .PRELIMINARY POINT TEMPS/POPS... TPA 64 73 51 64 / 80 70 10 10 FMY 66 78 58 70 / 40 50 20 10 GIF 63 75 50 66 / 70 70 10 10 SRQ 66 73 53 65 / 70 70 10 10 BKV 63 74 42 63 / 90 70 0 10 SPG 65 72 54 63 / 80 70 10 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/FIRE WX...MROCZKA AVIATION...RUDE MARINE...MCKAUGHAN LONG TERM...GARCIA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
351 PM CST MON JAN 13 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 230 PM CST MON JAN 13 2014 MORE COMPLICATED FORECAST BASED ON THE LATEST WARMER AIR IN SD...AND THE ORIENTATION OF THE FORCING LATER THIS EVENING. CURRENT REGIONAL RADAR INDICATED A BAND OF -SN IN NE SD/SE ND/WC MN WHICH WAS ASSOCIATED WITH A 50H JET STREAK AHEAD OF THE MAIN STORM SYSTEM AFFECTING THE REGION THIS EVENING/OVERNIGHT. INITIALLY...WARMER AIR BLW 3K IN SW MN MAY CAUSE SOME OF THE PRECIPITATION TO BE IN THE FORM OF RAIN/SLEET. TEMPS IN WC/SW MN ON THE LEE SIDE OF THE BUFFALO RIDGE ARE IN THE LOW TO MID 30S WITH DEW PTS IN THE 20S. FORCING IN THIS AREA IS NOT STRONG UNTIL AFTER MIDNIGHT AS MORE CONVERGENCE ALONG A DEVELOPING WARM FRONTAL BOUNDARY BEGINS. HOWEVER...AT THE SAME TIME...THE SFC REFLECTION OF THE MAIN WX SYSTEM MOVES ACROSS THE I-94 CORRIDOR LEADING TO A NIL BETWEEN THE TWO FORCING ELEMENTS. THEREFORE...LACK OF FORCING IN SW/SC MN THIS EVENING WILL LEAD TO MORE SLEET/SPRINKLES OR FREEZING DRIZZLE DEPENDING UPON THE SFC TEMP. ANOTHER ELEMENT IS WHETHER BLOWING SNOW DEVELOPS LATE TONIGHT AS THE SFC LOW MOVES SE OF MN. IF A LIMITED AMT OF SNOWFALL OR A MIXTURE OF SLEET/FZDZ/-RA DEVELOPS...THIS WILL LOWER THE SNOWFALL TOTALS OR AT LEAST MAKE FOR A SNOWFALL RATIO OF 5-1 /WET SLUSHY SNOW/. DUE TO THE CHC OF FREEZING PRECIPITATION AND THE OCCURRENCE OF WET SNOW...WILL UPDATE THE WINTER WX ADVISORY WITH MORE INFLUENCE OF FREEZING PRECIPITATION IN SW/SC MN...VS SNOWFALL AMTS/BLOWING SNOW. FURTHER NORTH...AND MAINLY ACROSS I-94 OR NE OF I-94...SNOWFALL AMTS SHOULD REMAIN IN THE TWO TO FOUR INCH RANGE BY TUESDAY MORNING. DEPENDING UPON WHERE THIS INITIAL 85H/70H FRONTOGENETIC SNOW BAND DEVELOPS...WILL DETERMINE WHERE THE HEAVIER SNOWFALL AMTS WILL BE OVERNIGHT. BASED ON THE LATEST MODEL INFORMATION...A BAND OF TWO TO FOUR INCHES WILL OCCUR FROM THE NORTHERN SUBURBS OF THE TWIN CITIES...EASTWARD TOWARD EAU CLAIRE WI. FURTHER REFINING OF THE SNOWFALL TOTALS ARE EXPECTED THIS EVENING FOR THOSE WHO ARE INTERESTED IN PLOWING. NO CHGS TO TEMPS FOR TUESDAY...BUT SUSTAINED WINDS OF 20 TO 35 MPH IN WC/SW/SC WILL CREATE SOME BLOWING SNOW...ESPECIALLY IN AREAS THAT RECEIVE AN INCH OR TWO OVERNIGHT. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 310 PM CST MON JAN 13 2014 LONG TERM CONCERNS INCLUDE LIGHT SNOW/FREEZING DRIZZLE/LIGHT FREEZING RAIN WEDNESDAY INTO WEDNESDAY EVENING...AND THEN STRONG WINDS DEVELOPING THURSDAY. MODELS INDICATE STRONG WARMING ALOFT ON WEDNESDAY AHEAD AMPLIFIED TROUGH. SHOULD DEVELOP A POSSIBLE LIGHT MIX OF FREEZING RAIN OR SNOW AS IT MOVES EAST ACROSS THE AREA INTO WEDNESDAY EVENING. SOME QUESTION AS TO HOW DEEP A MOIST LAYER WILL BE INVOLDED AND HOW MUCH ICE WILL BE INTRODUCED AND INVOLVED WITH THE WARM LAYER. SHOULD SEE SLOWLY RISING TEMPERATURES OVER MUCH OF THE CWA INTO WEDNESDAY NIGHT AHEAD OF THE SECONDARY FRONT. WILL WILL HAVE TO MONITOR THIS INTO THURSDAY...AS SECONDARY ARCTIC FRONT ARRIVES. TIMING IN QUESTION...BUT MOST MODELS SUGGEST A THURSDAY MORNING ARRIVAL TO THE WEST AND SPREADING RAPIDLY SOUTHEAST DURING THE DAY. SOME LIGHT SNOW/SNOW SHOWER ACTIVITY LIKELY WITH THIS STRONG TROUGH AS IT ROTATES SOUTHEAST OVER THE REGION. HAVE HIGHER CHANCE POPS MOST AREAS...WHICH MAY HAVE TO BE INCREASED. IMPRESSIVE H5 HEIGHT FALLS OF OVER 20 DAMS INDICATED WITH THIS TROUGH AND STRONG PV ASSOCIATED THROUGH THURSDAY MORNING. WINDS ARE FORECAST TO BE SUSTAINED 25-30 KTS WITH GUSTS TO 45 KTS LIKELY IN THE SOUTHWEST...WHERE 10-15 MB 6 HOUR SURFACE PRESSURE RISES MOVE THROUGH. WILL HAVE TO MONITOR THIS FOR DEVELOPMENT OF BLOWING SNOW...AND POSSIBLE NEAR BLIZZARD CONDITIONS OVER THIS REGION. ESPECIALLY IF WE GET APPRECIABLE SNOW OVERNIGHT TONIGHT AND AGAIN ON WEDNESDAY IN THIS AREA. COOLING BEHIND TROUGH AS THE AMPLIFIED TROUGH DIGS TO THE SOUTHEAST OVER THE EASTERN CONUS INTO THE WEEKEND. SOME INDICATION OF ANOTHER WEAK CLIPPER MOVING SOUTHEAST IN NORTHWEST FLOW OVER THE AREA FRIDAY NIGHT OR SATURDAY. HAVE INCLUDED THE SLIGHT CHANCE OF SNOW FOR FRIDAY NIGHT FOR NOW. THIS MAY BE INCREASED OR SHIFTED INTO SATURDAY IF THE GFS AND GEM COME CLOSE TO VERIFYING DURING THIS PERIOD. UPPER LEVEL FLOW PATTERN FLATTENS ONCE AGAIN LATE IN THE WEEKEND...AND THIS WILL ALLOW MORE PACIFIC TYPE AIR TO RIDGE ACROSS THE NORTHERN PLAINS...SUGGESTING A WARMING TREND THEN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1125 AM CST MON JAN 13 2014 STILL ON TRACK TO SEE IFR...POSSIBLY LIFR CIGS/VSBYS IN SN AT MOST MPX TAF SITES OVER THE NEXT 6 TO 15 HRS. TIMING IS THE MAIN FACTOR AS RADAR RETURNS IN THE DAKOTAS ARE STILL NOT TOO IMPRESSIVE AS OF 1145 AM. THESE 18Z TAFS ARE BASED ON THE CURRENT MODEL TRENDS OF THE HOPWRK AND RAP WHICH INDICATED A BAND OF SNOW DEVELOPING IN WC MN BETWEEN 22-00Z...THEN SPREADING RAPIDLY OR DEVELOPING THE SNOW RAPIDLY EASTWARD BETWEEN 00-03Z ACROSS EC MN. HIGHER REFLECTIVITY RETURNS INDICATED THAT SOME OF THE SNOW WILL BE MODERATE OR POSSIBLY HEAVY AT TIMES FOR A SHORT PERIOD. TIMING AGAIN IS TOO SOON FOR ANY MAJOR DEVIATION FROM PREVIOUS TAFS. I DID ADD A TEMPORARY PERIOD OF MODERATE SNOWFALL WITH VSBYS OF 1/2SM AT KRWF AND KEAU. AFTER THE MAIN BAND OF SNOW MOVES SE/ESE ACROSS SW/SC WI BY TUESDAY MORNING...BLSN WILL BE A PROBLEM...POSSIBLY A MAJOR PROBLEM WITH THE LIGHT ACCUMULATIONS EXPECTED OVER THE NEXT 24 HRS. WINDS WILL CHG FROM SW/WSW THIS AFTN...TO E/SE...THEN N/NW BY TUESDAY MORNING. SUSTAINED WINDS OF 20-25 KTS WITH GUSTS OF 28-30 KTS ARE LIKELY AT KRWF/KAXN TUESDAY MORNING IN BLSN. KMSP... NO MAJOR CHGS TO PREVIOUS TAF WITH IFR CONDS POSSIBLY DEVELOPING AN HR EARLIER THAN EXPECTED. HOWEVER...CONFIDENCE REMAINS LOW FOR THE ONSET OF -SN...BUT ONCE -SN DEVELOPS...VSBYS/CIGS WILL RAPIDLY DECREASE. SOME SLOWLY IMPROVEMENTS TOWARD 8-10Z. HOWEVER...CONFIDENCE REMAINS LOW FOR IMPROVEMENTS ONCE WINDS INCREASE FROM THE NW TUESDAY MORNING WITH AREAS OF BLSN. HAVE INTRODUCE A PERIOD TUESDAY MORNING OF MVFR CIGS/VSBYS IN BLSN. WINDS THIS AFTN WILL BECOME MORE WSW/SW AND DECREASE...THEN BECOME MORE LIGHT SE/E THIS EVENING...THEN N/NW TUESDAY MORNING AND INCREASING ONCE AGAIN. /OUTLOOK FOR KMSP/ TUE EVENING...VFR. WNW WINDS ARND 10 KTS. WED...VFR BECOMING MVFR CIG CHC -SN LATE. WIND W 5 KT BECMG SW10-20KT. THU...MVFR CIG AND SCATTERED -SHSN POSSIBLE WITH STRONG WINDS. WIND NW 20G35KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 3 PM CST TUESDAY FOR MNZ060>063-069-070-076>078-084-085-093. WINTER WEATHER ADVISORY UNTIL 3 PM CST TUESDAY FOR MNZ041- 047>049-051-054>059-064>068-073>075-082-083-091-092. WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 3 PM CST TUESDAY FOR WIZ023>028. && $$ SHORT TERM...JLT LONG TERM...DWE AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
256 PM CST MON JAN 13 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 230 PM CST MON JAN 13 2014 MORE COMPLICATED FORECAST BASED ON THE LATEST WARMER AIR IN SD...AND THE ORIENTATION OF THE FORCING LATER THIS EVENING. CURRENT REGIONAL RADAR INDICATED A BAND OF -SN IN NE SD/SE ND/WC MN WHICH WAS ASSOCIATED WITH A 50H JET STREAK AHEAD OF THE MAIN STORM SYSTEM AFFECTING THE REGION THIS EVENING/OVERNIGHT. INITIALLY...WARMER AIR BLW 3K IN SW MN MAY CAUSE SOME OF THE PRECIPITATION TO BE IN THE FORM OF RAIN/SLEET. TEMPS IN WC/SW MN ON THE LEE SIDE OF THE BUFFALO RIDGE ARE IN THE LOW TO MID 30S WITH DEW PTS IN THE 20S. FORCING IN THIS AREA IS NOT STRONG UNTIL AFTER MIDNIGHT AS MORE CONVERGENCE ALONG A DEVELOPING WARM FRONTAL BOUNDARY BEGINS. HOWEVER...AT THE SAME TIME...THE SFC REFLECTION OF THE MAIN WX SYSTEM MOVES ACROSS THE I-94 CORRIDOR LEADING TO A NIL BETWEEN THE TWO FORCING ELEMENTS. THEREFORE...LACK OF FORCING IN SW/SC MN THIS EVENING WILL LEAD TO MORE SLEET/SPRINKLES OR FREEZING DRIZZLE DEPENDING UPON THE SFC TEMP. ANOTHER ELEMENT IS WHETHER BLOWING SNOW DEVELOPS LATE TONIGHT AS THE SFC LOW MOVES SE OF MN. IF A LIMITED AMT OF SNOWFALL OR A MIXTURE OF SLEET/FZDZ/-RA DEVELOPS...THIS WILL LOWER THE SNOWFALL TOTALS OR AT LEAST MAKE FOR A SNOWFALL RATIO OF 5-1 /WET SLUSHY SNOW/. DUE TO THE CHC OF FREEZING PRECIPITATION AND THE OCCURRENCE OF WET SNOW...WILL UPDATE THE WINTER WX ADVISORY WITH MORE INFLUENCE OF FREEZING PRECIPITATION IN SW/SC MN...VS SNOWFALL AMTS/BLOWING SNOW. FURTHER NORTH...AND MAINLY ACROSS I-94 OR NE OF I-94...SNOWFALL AMTS SHOULD REMAIN IN THE TWO TO FOUR INCH RANGE BY TUESDAY MORNING. DEPENDING UPON WHERE THIS INITIAL 85H/70H FRONTOGENETIC SNOW BAND DEVELOPS...WILL DETERMINE WHERE THE HEAVIER SNOWFALL AMTS WILL BE OVERNIGHT. BASED ON THE LATEST MODEL INFORMATION...A BAND OF TWO TO FOUR INCHES WILL OCCUR FROM THE NORTHERN SUBURBS OF THE TWIN CITIES...EASTWARD TOWARD EAU CLAIRE WI. FURTHER REFINING OF THE SNOWFALL TOTALS ARE EXPECTED THIS EVENING FOR THOSE WHO ARE INTERESTED IN PLOWING. NO CHGS TO TEMPS FOR TUESDAY...BUT SUSTAINED WINDS OF 20 TO 35 MPH IN WC/SW/SC WILL CREATE SOME BLOWING SNOW...ESPECIALLY IN AREAS THAT RECEIVE AN INCH OR TWO OVERNIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 421 AM CST MON JAN 13 2014 STRONG WINDS ON TUESDAY...AND MORE SO ON THURSDAY ARE THE TWO MAIN ITEMS OF CONCERN IN THE EXTENDED TIME-FRAME. FRIDAY WILL BE COLD AND DRY...WITH TEMPERATURES MODERATING ABOVE NORMAL ONCE AGAIN BY SUNDAY. AT THE START OF THE PERIOD...A BROAD AREA OF SNOWFALL WILL BE ONGOING ACROSS THE EASTERN HALF OF THE FORECAST AREA. DESPITE THE WARM AIR ADVECTION AND BROAD ISENTROPIC ASCENT...THE FGEN SIGNAL WITH THIS SNOWFALL IS RELATIVELY WEEK...SO NOT ANTICIPATING A PARTICULARLY HEAVY BAND OF SNOW. HOWEVER SUSTAINED RATES OF 1/4 TO 1/3 INCH PER HOUR SHOULD YIELD OVERALL TOTALS OF 2-4 INCHES ALONG THE I-94 CORRIDOR. THERMAL PROFILES ARE ON THE WARMER SIDE OF THE IDEAL DENDRITIC GROWTH SPECTRUM...SO RATIOS WILL BE CLOSER TO THE TYPICAL 10-12:1...AS OPPOSED TO THE 20:1 THAT OFTEN ACCOMPANIES CLIPPER SYSTEMS. HOWEVER...LIKE MOST CLIPPERS STRONG NORTHWEST WINDS WILL INCREASE ON THE BACK SIDE OF THE SURFACE LOW AS IT SLIDES SOUTHEASTWARD ACROSS THE REGION. FORECAST SOUNDINGS OFF BOTH THE GFS AND NAM 13.00 SHOW SEVERAL HOURS OF MID 30 TO LOW 40KT WINDS ATOP THE MIXED LAYER ON TUESDAY MORNING ALONG THE WIND-FAVORED REGIONS OF WESTERN MINNESOTA. HOWEVER THE COLD AIR ADVECTION IS NOT PARTICULARLY STRONG...AND THESE HIGHER WIND GUSTS SEEM TO BE ACHIEVED MOSTLY THROUGH DIURNAL MIXING. IN ADDITION...THE SATURATION IS CONFINED BETWEEN THE TOP OF THE BOUNDARY LAYER AND 700MB. THE CONCLUSION DRAWN FROM THESE TWO FEATURES (DRAWBACKS) IS THAT THE MODEL FORECAST WINDS MAY BE OVERDONE...BUT THE POTENTIAL EXISTS FOR BOUNDARY LAYER CONVECTIVE ROLLS AND SNOW SHOWERS. THEREFORE HAVE PROLONGED THE POPS THROUGH TUESDAY MORNING...AND HAVE WIND GUSTS NEAR 40MPH ACROSS WESTERN MN. SNOW DEPTH GENERALLY IS IN THE 3-6 ACROSS THIS REGION...AND HOPEFULLY THE LAST FEW DAYS WARMUP WILL KEEP REDUCED VISIBILITIES FROM BLOWING SNOW IN CHECK SO THAT AN UPGRADE TO BLIZZARD WARNING WILL NOT BE NECESSARY. THURSDAY MAY BE A DIFFERENT STORY HOWEVER MAINLY DUE TO THE INCREDIBLY STRONG WINDS FORECAST BY THE MODELS. AN UPPER LEVEL WAVE CURRENTLY OFF THE ALEUTIAN ISLANDS WILL CROSS THE CANADIAN ROCKIES TUESDAY NIGHT AND CAUSE A MID 970MB SURFACE LOW TO FORM OVER SOUTH CENTRAL CANADA ON WEDNESDAY. THIS LOW WILL TRACK EAST SOUTHEAST INTO SOUTHERN ONTARIO BY THURSDAY MORNING. THERE IS CONSIDERABLE UNCERTAINTY WITH THIS SYSTEM. THE GFS CONTINUES TO BE THE STRONGEST AND FARTHEST SOUTH...TAKING THE 980MB LOW TRACK ACROSS LAKE SUPERIOR. THE GEM 13.00 AND SREF 13.03 HAVE A SIMILAR TRACK...BUT ARE NOT AS DEEP BY ABOUT 5-10MB. MEANWHILE...THE ECMWF AND 84HR FORECAST OFF THE NAM ARE FARTHER NORTH. THE STRONGER GFS CONTINUES TO SHOW THE POTENTIAL FOR 50KT GUSTS ON THURSDAY...WHILE THE TAIL END OF THE NAM IS IN THE UPPER 30S. PERHAPS MOST IMPORTANTLY IS HOW A SECONDARY SHORTWAVE INTERACTS WITH THIS SYSTEM. THE GFS AND ECMWF BRING A POTENT PV ANOMALY SOUTHWARD ACROSS THE REGION AROUND 18Z THURSDAY. THE EFFECTS OF THIS WAVE ARE TWOFOLD. FIRST OF ALL...THIS WILL DRIVE AN ARCTIC FRONT THROUGH THE REGION. SECONDLY...IT WILL LEAD TO AN AREA OF POST FRONTAL LIGHT SNOW. AS MENTIONED EARLIER...GFS HAS 50KT WIND GUSTS IN THE BUFR SOUNDINGS. ALTHOUGH THIS DATA IS NOT AVAILABLE FOR THE ECMWF...THE 0-500M MIXED LAYER WINDS OFF BOTH MODELS SHOW 40KTS ACROSS WESTERN MN TUESDAY AS THAT FRONTAL PASSAGE MOVES THOUGH. NEEDLESS TO SAY SUSTAINED WINDS THAT STRONG WILL CAUSE SIGNIFICANT BLOWING AND DRIFTING...WITH BLIZZARD CONDITIONS A NEAR CERTAINTY IF THE SNOWFALL COMES TO FRUITION AS WELL. AT THIS TIME WILL NOT GET TO BULLISH SINCE THERE ARE SEVERAL VARIABLES IN PLAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1125 AM CST MON JAN 13 2014 STILL ON TRACK TO SEE IFR...POSSIBLY LIFR CIGS/VSBYS IN SN AT MOST MPX TAF SITES OVER THE NEXT 6 TO 15 HRS. TIMING IS THE MAIN FACTOR AS RADAR RETURNS IN THE DAKOTAS ARE STILL NOT TOO IMPRESSIVE AS OF 1145 AM. THESE 18Z TAFS ARE BASED ON THE CURRENT MODEL TRENDS OF THE HOPWRK AND RAP WHICH INDICATED A BAND OF SNOW DEVELOPING IN WC MN BETWEEN 22-00Z...THEN SPREADING RAPIDLY OR DEVELOPING THE SNOW RAPIDLY EASTWARD BETWEEN 00-03Z ACROSS EC MN. HIGHER REFLECTIVITY RETURNS INDICATED THAT SOME OF THE SNOW WILL BE MODERATE OR POSSIBLY HEAVY AT TIMES FOR A SHORT PERIOD. TIMING AGAIN IS TOO SOON FOR ANY MAJOR DEVIATION FROM PREVIOUS TAFS. I DID ADD A TEMPORARY PERIOD OF MODERATE SNOWFALL WITH VSBYS OF 1/2SM AT KRWF AND KEAU. AFTER THE MAIN BAND OF SNOW MOVES SE/ESE ACROSS SW/SC WI BY TUESDAY MORNING...BLSN WILL BE A PROBLEM...POSSIBLY A MAJOR PROBLEM WITH THE LIGHT ACCUMULATIONS EXPECTED OVER THE NEXT 24 HRS. WINDS WILL CHG FROM SW/WSW THIS AFTN...TO E/SE...THEN N/NW BY TUESDAY MORNING. SUSTAINED WINDS OF 20-25 KTS WITH GUSTS OF 28-30 KTS ARE LIKELY AT KRWF/KAXN TUESDAY MORNING IN BLSN. KMSP... NO MAJOR CHGS TO PREVIOUS TAF WITH IFR CONDS POSSIBLY DEVELOPING AN HR EARLIER THAN EXPECTED. HOWEVER...CONFIDENCE REMAINS LOW FOR THE ONSET OF -SN...BUT ONCE -SN DEVELOPS...VSBYS/CIGS WILL RAPIDLY DECREASE. SOME SLOWLY IMPROVEMENTS TOWARD 8-10Z. HOWEVER...CONFIDENCE REMAINS LOW FOR IMPROVEMENTS ONCE WINDS INCREASE FROM THE NW TUESDAY MORNING WITH AREAS OF BLSN. HAVE INTRODUCE A PERIOD TUESDAY MORNING OF MVFR CIGS/VSBYS IN BLSN. WINDS THIS AFTN WILL BECOME MORE WSW/SW AND DECREASE...THEN BECOME MORE LIGHT SE/E THIS EVENING...THEN N/NW TUESDAY MORNING AND INCREASING ONCE AGAIN. /OUTLOOK FOR KMSP/ TUE EVENING...VFR. WNW WINDS ARND 10 KTS. WED...VFR BECOMING MVFR CIG CHC -SN LATE. WIND W 5 KT BECMG SW10-20KT. THU...MVFR CIG AND SCATTERED -SHSN POSSIBLE WITH STRONG WINDS. WIND NW 20G35KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 3 PM CST TUESDAY FOR MNZ060>063-069-070-076>078-084-085-093. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 3 PM CST TUESDAY FOR MNZ041-047>049-051-054>059-064>068-073>075-082- 083-091-092. WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 3 PM CST TUESDAY FOR WIZ023>028. && $$ SHORT TERM...JLT LONG TERM...JRB AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1150 AM CST MON JAN 13 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 421 AM CST MON JAN 13 2014 A FAIRLY ROBUST CLIPPER /SHOWING THE WHITES OF ITS EYES OVER BRITISH COLUMBIA AND ALBERTA ON 0930Z WATER VAPOR IMAGERY/ IS STILL ON TRACK TO ARRIVE THIS EVENING...AND BRING THE POTENTIAL FOR A PLOWABLE SNOWFALL TO PARTS OF CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN TONIGHT INTO TUESDAY MORNING. THE SNOWFALL IS EXPECTED TO START BY LATE AFTERNOON OVER FAR WEST CENTRAL MN...AND THEN EXPAND EASTWARD THROUGHOUT THE EVENING HOURS...REACHING WEST CENTRAL WI BY NIGHTFALL. NORTHWEST WINDS WILL BE ON THE INCREASE OVERNIGHT AS WELL...ESPECIALLY ACROSS THE TYPICAL AREAS OF WEST CENTRAL AND SOUTHWEST MN...WHERE SUSTAINED SPEEDS AROUND 30 MPH WITH GUSTS TO 40 MPH ARE EXPECTED TO DEVELOP. BLOWING SNOW WILL THEREFORE LIKELY BE AN ISSUE...ESPECIALLY ALONG THE BUFFALO RIDGE/MN RIVER VALLEY...WHERE A WINTER WEATHER ADVISORY WILL BE NEEDED. TO THE NORTH AND EAST OF THAT REGION...INCLUDING THE INTERSTATE 94 CORRIDOR FROM ALEXANDRIA TO THE TWIN CITIES TO EAU CLAIRE...WHILE BLOWING SNOW WILL BE LESS OF AN ISSUE...ANTICIPATE SNOWFALL ACCUMULATIONS IN THE 3-4 INCH RANGE IN THE CRITICAL PRE- DAWN TIME-FRAME OF TUESDAY MORNING...WHICH ALSO JUSTIFIES A WINTER WEATHER ADVISORY. REGARDING TEMPERATURES OVER THE NEXT 24 HOURS...RELATIVELY MILD READINGS WILL PERSIST. HIGHS TODAY WILL TOP OUT FROM THE LOWER 20S TO LOWER 30S. LOWS TONIGHT WILL MAINLY RANGE FROM THE LOWER TEENS TO MID 20S. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 421 AM CST MON JAN 13 2014 STRONG WINDS ON TUESDAY...AND MORE SO ON THURSDAY ARE THE TWO MAIN ITEMS OF CONCERN IN THE EXTENDED TIME-FRAME. FRIDAY WILL BE COLD AND DRY...WITH TEMPERATURES MODERATING ABOVE NORMAL ONCE AGAIN BY SUNDAY. AT THE START OF THE PERIOD...A BROAD AREA OF SNOWFALL WILL BE ONGOING ACROSS THE EASTERN HALF OF THE FORECAST AREA. DESPITE THE WARM AIR ADVECTION AND BROAD ISENTROPIC ASCENT...THE FGEN SIGNAL WITH THIS SNOWFALL IS RELATIVELY WEEK...SO NOT ANTICIPATING A PARTICULARLY HEAVY BAND OF SNOW. HOWEVER SUSTAINED RATES OF 1/4 TO 1/3 INCH PER HOUR SHOULD YIELD OVERALL TOTALS OF 2-4 INCHES ALONG THE I-94 CORRIDOR. THERMAL PROFILES ARE ON THE WARMER SIDE OF THE IDEAL DENDRITIC GROWTH SPECTRUM...SO RATIOS WILL BE CLOSER TO THE TYPICAL 10-12:1...AS OPPOSED TO THE 20:1 THAT OFTEN ACCOMPANIES CLIPPER SYSTEMS. HOWEVER...LIKE MOST CLIPPERS STRONG NORTHWEST WINDS WILL INCREASE ON THE BACK SIDE OF THE SURFACE LOW AS IT SLIDES SOUTHEASTWARD ACROSS THE REGION. FORECAST SOUNDINGS OFF BOTH THE GFS AND NAM 13.00 SHOW SEVERAL HOURS OF MID 30 TO LOW 40KT WINDS ATOP THE MIXED LAYER ON TUESDAY MORNING ALONG THE WIND-FAVORED REGIONS OF WESTERN MINNESOTA. HOWEVER THE COLD AIR ADVECTION IS NOT PARTICULARLY STRONG...AND THESE HIGHER WIND GUSTS SEEM TO BE ACHIEVED MOSTLY THROUGH DIURNAL MIXING. IN ADDITION...THE SATURATION IS CONFINED BETWEEN THE TOP OF THE BOUNDARY LAYER AND 700MB. THE CONCLUSION DRAWN FROM THESE TWO FEATURES (DRAWBACKS) IS THAT THE MODEL FORECAST WINDS MAY BE OVERDONE...BUT THE POTENTIAL EXISTS FOR BOUNDARY LAYER CONVECTIVE ROLLS AND SNOW SHOWERS. THEREFORE HAVE PROLONGED THE POPS THROUGH TUESDAY MORNING...AND HAVE WIND GUSTS NEAR 40MPH ACROSS WESTERN MN. SNOW DEPTH GENERALLY IS IN THE 3-6 ACROSS THIS REGION...AND HOPEFULLY THE LAST FEW DAYS WARMUP WILL KEEP REDUCED VISIBILITIES FROM BLOWING SNOW IN CHECK SO THAT AN UPGRADE TO BLIZZARD WARNING WILL NOT BE NECESSARY. THURSDAY MAY BE A DIFFERENT STORY HOWEVER MAINLY DUE TO THE INCREDIBLY STRONG WINDS FORECAST BY THE MODELS. AN UPPER LEVEL WAVE CURRENTLY OFF THE ALEUTIAN ISLANDS WILL CROSS THE CANADIAN ROCKIES TUESDAY NIGHT AND CAUSE A MID 970MB SURFACE LOW TO FORM OVER SOUTH CENTRAL CANADA ON WEDNESDAY. THIS LOW WILL TRACK EAST SOUTHEAST INTO SOUTHERN ONTARIO BY THURSDAY MORNING. THERE IS CONSIDERABLE UNCERTAINTY WITH THIS SYSTEM. THE GFS CONTINUES TO BE THE STRONGEST AND FARTHEST SOUTH...TAKING THE 980MB LOW TRACK ACROSS LAKE SUPERIOR. THE GEM 13.00 AND SREF 13.03 HAVE A SIMILAR TRACK...BUT ARE NOT AS DEEP BY ABOUT 5-10MB. MEANWHILE...THE ECMWF AND 84HR FORECAST OFF THE NAM ARE FARTHER NORTH. THE STRONGER GFS CONTINUES TO SHOW THE POTENTIAL FOR 50KT GUSTS ON THURSDAY...WHILE THE TAIL END OF THE NAM IS IN THE UPPER 30S. PERHAPS MOST IMPORTANTLY IS HOW A SECONDARY SHORTWAVE INTERACTS WITH THIS SYSTEM. THE GFS AND ECMWF BRING A POTENT PV ANOMALY SOUTHWARD ACROSS THE REGION AROUND 18Z THURSDAY. THE EFFECTS OF THIS WAVE ARE TWOFOLD. FIRST OF ALL...THIS WILL DRIVE AN ARCTIC FRONT THROUGH THE REGION. SECONDLY...IT WILL LEAD TO AN AREA OF POST FRONTAL LIGHT SNOW. AS MENTIONED EARLIER...GFS HAS 50KT WIND GUSTS IN THE BUFR SOUNDINGS. ALTHOUGH THIS DATA IS NOT AVAILABLE FOR THE ECMWF...THE 0-500M MIXED LAYER WINDS OFF BOTH MODELS SHOW 40KTS ACROSS WESTERN MN TUESDAY AS THAT FRONTAL PASSAGE MOVES THOUGH. NEEDLESS TO SAY SUSTAINED WINDS THAT STRONG WILL CAUSE SIGNIFICANT BLOWING AND DRIFTING...WITH BLIZZARD CONDITIONS A NEAR CERTAINTY IF THE SNOWFALL COMES TO FRUITION AS WELL. AT THIS TIME WILL NOT GET TO BULLISH SINCE THERE ARE SEVERAL VARIABLES IN PLAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1125 AM CST MON JAN 13 2014 STILL ON TRACK TO SEE IFR...POSSIBLY LIFR CIGS/VSBYS IN SN AT MOST MPX TAF SITES OVER THE NEXT 6 TO 15 HRS. TIMING IS THE MAIN FACTOR AS RADAR RETURNS IN THE DAKOTAS ARE STILL NOT TOO IMPRESSIVE AS OF 1145 AM. THESE 18Z TAFS ARE BASED ON THE CURRENT MODEL TRENDS OF THE HOPWRK AND RAP WHICH INDICATED A BAND OF SNOW DEVELOPING IN WC MN BETWEEN 22-00Z...THEN SPREADING RAPIDLY OR DEVELOPING THE SNOW RAPIDLY EASTWARD BETWEEN 00-03Z ACROSS EC MN. HIGHER REFLECTIVITY RETURNS INDICATED THAT SOME OF THE SNOW WILL BE MODERATE OR POSSIBLY HEAVY AT TIMES FOR A SHORT PERIOD. TIMING AGAIN IS TOO SOON FOR ANY MAJOR DEVIATION FROM PREVIOUS TAFS. I DID ADD A TEMPORARY PERIOD OF MODERATE SNOWFALL WITH VSBYS OF 1/2SM AT KRWF AND KEAU. AFTER THE MAIN BAND OF SNOW MOVES SE/ESE ACROSS SW/SC WI BY TUESDAY MORNING...BLSN WILL BE A PROBLEM...POSSIBLY A MAJOR PROBLEM WITH THE LIGHT ACCUMULATIONS EXPECTED OVER THE NEXT 24 HRS. WINDS WILL CHG FROM SW/WSW THIS AFTN...TO E/SE...THEN N/NW BY TUESDAY MORNING. SUSTAINED WINDS OF 20-25 KTS WITH GUSTS OF 28-30 KTS ARE LIKELY AT KRWF/KAXN TUESDAY MORNING IN BLSN. KMSP... NO MAJOR CHGS TO PREVIOUS TAF WITH IFR CONDS POSSIBLY DEVELOPING AN HR EARLIER THAN EXPECTED. HOWEVER...CONFIDENCE REMAINS LOW FOR THE ONSET OF -SN...BUT ONCE -SN DEVELOPS...VSBYS/CIGS WILL RAPIDLY DECREASE. SOME SLOWLY IMPROVEMENTS TOWARD 8-10Z. HOWEVER...CONFIDENCE REMAINS LOW FOR IMPROVEMENTS ONCE WINDS INCREASE FROM THE NW TUESDAY MORNING WITH AREAS OF BLSN. HAVE INTRODUCE A PERIOD TUESDAY MORNING OF MVFR CIGS/VSBYS IN BLSN. WINDS THIS AFTN WILL BECOME MORE WSW/SW AND DECREASE...THEN BECOME MORE LIGHT SE/E THIS EVENING...THEN N/NW TUESDAY MORNING AND INCREASING ONCE AGAIN. /OUTLOOK FOR KMSP/ TUE EVENING...VFR. WNW WINDS ARND 10 KTS. WED...VFR BECOMING MVFR CIG CHC -SN LATE. WIND W 5 KT BECMG SW10-20KT. THU...MVFR CIG AND SCATTERED -SHSN POSSIBLE WITH STRONG WINDS. WIND NW 20G35KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 3 PM CST TUESDAY FOR MNZ060>063-069-070-076>078-084-085-093. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 3 PM CST TUESDAY FOR MNZ041-047>049-051-054>059-064>068-073>075-082- 083-091-092. WI...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 3 PM CST TUESDAY FOR WIZ023>028. && $$ SHORT TERM...LS LONG TERM...JRB AVIATION...JLT
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
124 PM EST MON JAN 13 2014 .SYNOPSIS... HIGH PRESSURE WILL BE CENTERED OFF THE SOUTHEAST COAST THROUGH TONIGHT. A COLD FRONT WILL CROSS THE REGION TUESDAY...FOLLOWED BY A SECONDARY COLD FRONT WEDNESDAY NIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN THURSDAY. A STRONG COLD FRONT WILL MOVE ACROSS FRIDAY FOLLOWED BY HIGH PRESSURE NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1 PM...NO SIGNIFICANT CHANGES THIS UPDATE. UPPER RIDGE AXIS OVER THE REGION THIS MORNING MOVES OFFSHORE TODAY. WITH SFC HIGH PRES OFF THE SE CST A DEEPER MILDER SW FLOW WILL DEVELOP. SUNNY SKIES EARLY WITH MAINLY HIGH CLOUDS INCREASING DURING THE AFTERNOON. INCREASING THICKNESSES WILL LEAD TO HIGHS IN THE 60 TO 65 DEGREE RANGE THIS AFTERNOON...ABOUT 10 DEGS ABOVE NORMAL FOR MID JANUARY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/... A ROBUST SHORTWAVE TROUGH DIGS THRU THE TN VALLEY TONIGHT. DEEPER MOISTURE QUICKLY OVERSPREADS THE SE STATES OVERNIGHT AND WILL MAINTAIN LIKELY POPS AFTER MIDNIGHT OVER THE FORECAST AREA GIVEN THE CONSISTENT MODEL SOLUTIONS. SOUTHERLY FLOW CONTINUES THE MILD TEMPERATURES OVERNIGHT WITH LOWS IN THE UPPER 40S TO LOW 50S. && .LONG TERM /TUESDAY THROUGH SUNDAY/... AS OF 3 AM MON...A PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE LONG TERM WITH SEVERAL AMPLIFIED SYSTEMS MOVING THROUGH THE FLOW ALOFT. A SHORTWAVE WILL MOVE THROUGH THE SE STATES TUE...WITH A WEAK AREA OF LOW PRES LIFTING ACROSS THE AREA...AND A COLD FRONT PUSHING THROUGH EASTERN NC TUE AFTERNOON. CONTINUED LIKELY POPS INLAND...AND INCREASED TO CATEGORICAL ALONG THE COAST. MODELS STILL INDICATING STRONG LOW LEVEL SHEAR WILL BE IN PLACE...HOWEVER SEVERE CHANCES APPEAR MINIMAL AT THIS TIME AS MODELS CONTINUE TO SHOW LITTLE/NO INSTABILITY ACROSS THE AREA EXCEPT THE OFFSHORE WATERS...AND WILL MAINTAIN CHC THUNDER THERE. SOUTHERLY FLOW BRINGS ABOVE NORMAL TEMPS TUE WITH HIGHS IN THE UPPER 50S TO LOWER 60S. A LONGWAVE UPPER TROUGH WILL REMAIN ACROSS THE EASTERN CONUS TUE NIGHT WITH ANOTHER ROBUST SHORTWAVE TROUGH AND COLD FRONT PROGGED TO PUSH ACROSS THE REGION WED AND THU. A 12Z GFS/ENSEMBLE COMPROMISE IS FAVORED THIS TIME PERIOD AS THEY HAVE BEEN THE MOST CONSISTENT. FORCING AHEAD OF THIS TROUGH COULD BRING ADDITIONAL RAIN CHANCES WED BUT MOISTURE EXPECTED TO BE LIMITED AND QPF AMOUNTS EXPECTED TO BE LIGHT. THE UPPER TROUGH QUICKLY PUSHES OFFSHORE EARLY THU WITH SHORTWAVE RIDGING AND SFC HIGH PRES PROGGED TO BRIEFLY BUILD INTO THE REGION THU. THE 00Z ECMWF RUN VERY SIMILAR TO PREVIOUS 12Z...WHICH IS MORE AMPLIFIED WITH THE SHORTWAVE WED AND THURS...AND THEN DEVELOPS A CUTOFF LOW ACROSS THE SOUTHEAST WED NIGHT AND LIFTING A LOW PRES AREA JUST OFFSHORE THU. THIS SOLUTION WOULD DELAY PCPN UNTIL WED NIGHT AND THU...BE WETTER AND POSSIBLY BRING P-TYPE CONCERNS INTO THE FORECAST. WPC CONTINUES TO FAVOR THE GFS AND ENSEMBLE SOLUTIONS AS OPPOSED TO LATEST ECMWF OPERATIONAL RUNS. CYCLONIC FLOW RETURNS ALOFT THU NIGHT AND FRI WITH THE SFC HIGH PRES SLIDING OFFSHORE AHEAD OF THE NEXT FRONTAL SYSTEM. MOISTURE LOOKS RATHER LIMITED WITH THIS NRN STREAM SYSTEM AS WELL WITH MAINLY A DRY FRONTAL PASSAGE FRI EVENING. HIGH PRES BUILDS INTO THE REGION FROM THE WEST OVER THE WEEKEND. TEMPS SLIGHTLY BELOW SEASONAL NORMS EXPECTED LATE IN THE WEEK AND INTO NEXT WEEKEND...WITH HIGHS IN THE 40S AND LOWS IN THE UPPER 20S/MID 30S. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... SHORT TERM /THROUGH 18Z TUESDAY/... AS OF 1PM MON...VFR CONDITIONS THROUGH MUCH OF THE OVERNIGHT. CONDITIONS QUICKLY DETERIORATE BY EARLY MORNING TUESDAY AS A LOW PRESSURE SYSTEM RIDES UP THE SE COAST. SOUTHERLY WINDS MAY BE A BIT GUSTY THIS AFTERNOON...BUT WILL SUBSIDE WITH DAY TIME HEATING. SCATTERED CLOUDS WILL BE INTRODUCED LATER THIS AFTERNOON AND INCREASING TONIGHT. CEILINGS WILL ALSO QUICKLY DROP BY TUESDAY MORNING AS MOIST SOUTHERLY FLOW HELPS TRANSPORT HIGH PWAT VALUES. EXPECTING IFR CIGS ACROSS EASTERN NC BY 09-12Z AND IFR VSBYS EXPECTED AT OUR WESTERN TAF SITES...KPGV/KISO. PRECIPITATION WILL INCREASE THROUGH EARLY MORNING AND CONTINUE THROUGH THE REMAINDER OF THE DAY TUESDAY. SOUTHERLY WINDS AROUND 5-10KTS EXPECTED. LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3 AM MON...SUB-VFR CONDITIONS LIKELY TUE WITH WIDESPREAD SHOWERS ACROSS THE AREA. DRIER AIR RETURNS FOR MIDWEEK...EXPECT PRED VFR CONDITIONS...THOUGH COULD SEE ISOLATED SHOWERS WED WITH SECONDARY FRONTAL PASSAGE. HIGH PRES BUILDS ACROSS THE AREA THU WITH ANOTHER DRY FRONTAL PASSAGE EXPECTED LATE FRI. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1 PM...NO CHANGES SINCE PREVIOUS UPDATE. STILL LIGHT WINDS ALONG THE IMMEDIATE COAST. MADE MINOR TWEAKS PREVIOUS UPDATE TO THE WINDS GIVEN CURRENT LIGHT CONDITIONS ACROSS THE WATERS UNDER HIGH PRESSURE. INCORPORATED MORE RUC AND HIGH RES NMM...AND 12Z NAM INTO FORECAST FOR TODAY. HIGH IS SLIDING OFF THE COAST AND EXPECT WINDS WILL STILL INCREASE DURING THE AFTERNOON TO 10 TO 15 KT FROM THE CENTRAL WATERS SOUTH...BUT MIGHT HOLD OFF UNTIL EARLY THIS EVENING NORTHERN WATERS. ALSO INCORPORATED SOME OF THE 06Z WW3 GUIDANCE INTO OUR WAVE FORECAST TO SLOW INCREASE OF SEAS JUST SLIGHTLY GIVEN LIGHT WINDS. SEAS WILL STILL BUILD TO 3 TO 4 FT THIS AFTN...POSS 5 FT OUTER CNTRL WTRS LATE. WINDS CONTINUE TO RAMP UP OVERNIGHT AS COLD FRONT NEARS THE COAST WITH SW WINDS MAINLY 15-20 KT AND SEAS BUILDING TO 3-5 FT OVERNIGHT. LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3 AM MON...ELEVATED SEAS AND GUSTY SWLY WINDS WILL START OFF THE PERIOD TUE...AS A WEAK AREA OF LOW PRESSURE WILL LIFT NORTH THROUGH THE WATERS...WITH A WEAK COLD FRONT MOVING THROUGH TUE AFTERNOON. SW WINDS 15-25KT AND SEAS 4-7FT LIKELY TUE...WITH A PERIOD OF SCA CONDITIONS EXPECTED. WINDS BRIEFLY BECOME W 5-15 KT TUE NIGHT WITH SEAS SUBSIDING TO 3-5 FT. HOWEVER...WINDS QUICKLY BACK TO SW AND INCREASE TO 15-25 KT WED AHEAD OF A SECONDARY FRONT PROGGED TO MOVE ACROSS THE WATERS WED AFTERNOON/EVENING. STRONGER CAA BEHIND THIS FRONT WILL KEEP WINDS GUSTY...NW AROUND 15-25 KT...INTO THU MORNING. SEAS GENERALLY 3-6 FT WED INTO THU MORNING. WILL CONTINUE TO DISCOUNT THE OPERATIONAL ECMWF SOLUTION OF LIFTING ANOTHER LOW PRES AREA THURS AS THIS SOLUTION IS AN OUTLIER. WINDS BACK TO SW AND INCREASE TO 15-25 KT WITH SEAS INCREASING TO 4-6 FT FRI AHEAD OF YET ANOTHER FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...RSB/BTC SHORT TERM...BTC LONG TERM...SK/CQD AVIATION...LEP MARINE...RSB/BTC/SK/CQD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1235 PM EST MON JAN 13 2014 .SYNOPSIS... HIGH PRESSURE WILL BE CENTERED OFF THE SOUTHEAST COAST THROUGH TONIGHT. A COLD FRONT WILL CROSS THE REGION TUESDAY...FOLLOWED BY A SECONDARY COLD FRONT WEDNESDAY NIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN THURSDAY. A STRONG COLD FRONT WILL MOVE ACROSS FRIDAY FOLLOWED BY HIGH PRESSURE NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 10 AM...NO SIGNIFICANT CHANGES THIS UPDATE. UPPER RIDGE AXIS OVER THE REGION THIS MORNING MOVES OFFSHORE TODAY. WITH SFC HIGH PRES OFF THE SE CST A DEEPER MILDER SW FLOW WILL DEVELOP. SUNNY SKIES EARLY WITH MAINLY HIGH CLOUDS INCREASING DURING THE AFTERNOON. INCREASING THICKNESSES WILL LEAD TO HIGHS IN THE 60 TO 65 DEGREE RANGE THIS AFTERNOON...ABOUT 10 DEGS ABOVE NORMAL FOR MID JANUARY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/... A ROBUST SHORTWAVE TROUGH DIGS THRU THE TN VALLEY TONIGHT. DEEPER MOISTURE QUICKLY OVERSPREADS THE SE STATES OVERNIGHT AND WILL MAINTAIN LIKELY POPS AFTER MIDNIGHT OVER THE FORECAST AREA GIVEN THE CONSISTENT MODEL SOLUTIONS. SOUTHERLY FLOW CONTINUES THE MILD TEMPERATURES OVERNIGHT WITH LOWS IN THE UPPER 40S TO LOW 50S. && .LONG TERM /TUESDAY THROUGH MONDAY/... AS OF 3 AM MON...A PROGRESSIVE PATTERN WILL CONTINUE THROUGH THE LONG TERM WITH SEVERAL AMPLIFIED SYSTEMS MOVING THROUGH THE FLOW ALOFT. A SHORTWAVE WILL MOVE THROUGH THE SE STATES TUE...WITH A WEAK AREA OF LOW PRES LIFTING ACROSS THE AREA...AND A COLD FRONT PUSHING THROUGH EASTERN NC TUE AFTERNOON. CONTINUED LIKELY POPS INLAND...AND INCREASED TO CATEGORICAL ALONG THE COAST. MODELS STILL INDICATING STRONG LOW LEVEL SHEAR WILL BE IN PLACE...HOWEVER SEVERE CHANCES APPEAR MINIMAL AT THIS TIME AS MODELS CONTINUE TO SHOW LITTLE/NO INSTABILITY ACROSS THE AREA EXCEPT THE OFFSHORE WATERS...AND WILL MAINTAIN CHC THUNDER THERE. SOUTHERLY FLOW BRINGS ABOVE NORMAL TEMPS TUE WITH HIGHS IN THE UPPER 50S TO LOWER 60S. A LONGWAVE UPPER TROUGH WILL REMAIN ACROSS THE EASTERN CONUS TUE NIGHT WITH ANOTHER ROBUST SHORTWAVE TROUGH AND COLD FRONT PROGGED TO PUSH ACROSS THE REGION WED AND THU. A 12Z GFS/ENSEMBLE COMPROMISE IS FAVORED THIS TIME PERIOD AS THEY HAVE BEEN THE MOST CONSISTENT. FORCING AHEAD OF THIS TROUGH COULD BRING ADDITIONAL RAIN CHANCES WED BUT MOISTURE EXPECTED TO BE LIMITED AND QPF AMOUNTS EXPECTED TO BE LIGHT. THE UPPER TROUGH QUICKLY PUSHES OFFSHORE EARLY THU WITH SHORTWAVE RIDGING AND SFC HIGH PRES PROGGED TO BRIEFLY BUILD INTO THE REGION THU. THE 00Z ECMWF RUN VERY SIMILAR TO PREVIOUS 12Z...WHICH IS MORE AMPLIFIED WITH THE SHORTWAVE WED AND THURS...AND THEN DEVELOPS A CUTOFF LOW ACROSS THE SOUTHEAST WED NIGHT AND LIFTING A LOW PRES AREA JUST OFFSHORE THU. THIS SOLUTION WOULD DELAY PCPN UNTIL WED NIGHT AND THU...BE WETTER AND POSSIBLY BRING P-TYPE CONCERNS INTO THE FORECAST. WPC CONTINUES TO FAVOR THE GFS AND ENSEMBLE SOLUTIONS AS OPPOSED TO LATEST ECMWF OPERATIONAL RUNS. CYCLONIC FLOW RETURNS ALOFT THU NIGHT AND FRI WITH THE SFC HIGH PRES SLIDING OFFSHORE AHEAD OF THE NEXT FRONTAL SYSTEM. MOISTURE LOOKS RATHER LIMITED WITH THIS NRN STREAM SYSTEM AS WELL WITH MAINLY A DRY FRONTAL PASSAGE FRI EVENING. HIGH PRES BUILDS INTO THE REGION FROM THE WEST OVER THE WEEKEND. TEMPS SLIGHTLY BELOW SEASONAL NORMS EXPECTED LATE IN THE WEEK AND INTO NEXT WEEKEND...WITH HIGHS IN THE 40S AND LOWS IN THE UPPER 20S/MID 30S. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... SHORT TERM /THROUGH 18Z TUESDAY/... AS OF 1PM MON...VFR CONDITIONS THROUGH MUCH OF THE OVERNIGHT. CONDITIONS QUICKLY DETERIORATE BY EARLY MORNING TUESDAY AS A LOW PRESSURE SYSTEM RIDES UP THE SE COAST. SOUTHERLY WINDS MAY BE A BIT GUSTY THIS AFTERNOON...BUT WILL SUBSIDE WITH DAY TIME HEATING. SCATTERED CLOUDS WILL BE INTRODUCED LATER THIS AFTERNOON AND INCREASING TONIGHT. CEILINGS WILL ALSO QUICKLY DROP BY TUESDAY MORNING AS MOIST SOUTHERLY FLOW HELPS TRANSPORT HIGH PWAT VALUES. EXPECTING IFR CIGS ACROSS EASTERN NC BY 09-12Z AND IFR VSBYS EXPECTED AT OUR WESTERN TAF SITES...KPGV/KISO. PRECIPITATION WILL INCREASE THROUGH EARLY MORNING AND CONTINUE THROUGH THE REMAINDER OF THE DAY TUESDAY. SOUTHERLY WINDS AROUND 5-10KTS EXPECTED. LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3 AM MON...SUB-VFR CONDITIONS LIKELY TUE WITH WIDESPREAD SHOWERS ACROSS THE AREA. DRIER AIR RETURNS FOR MIDWEEK...EXPECT PRED VFR CONDITIONS...THOUGH COULD SEE ISOLATED SHOWERS WED WITH SECONDARY FRONTAL PASSAGE. HIGH PRES BUILDS ACROSS THE AREA THU WITH ANOTHER DRY FRONTAL PASSAGE EXPECTED LATE FRI. && .MARINE... SHORT TERM /THROUGH TONIGHT/... MADE MINOR TWEAKS TO THE WINDS GIVE CURRENT LIGHT CONDITIONS ACROSS THE WATERS UNDER HIGH PRESSURE. INCORPORATED MORE RUC AND HIGH RES NMM...AND 12Z NAM INTO FORECAST FOR TODAY. WINDS WILL STILL INCREASE DURING THE AFTERNOON TO 10 TO 15 KT FROM THE CENTRAL WATERS SOUTH...BUT MIGHT HOLD OFF UNTIL EARLY THIS EVENING NORTHERN WATERS. ALSO INCORPORATED SOME OF THE 06Z WW3 GUIDANCE INTO OUR WAVE FORECAST TO SLOW INCREASE OF SEAS JUST SLIGHTLY GIVEN LIGHT WINDS. SEAS WILL STILL BUILD TO 3 TO 4 FT THIS AFTN...POSS 5 FT OUTER CNTRL WTRS LATE. WINDS CONTINUE TO RAMP UP OVERNIGHT AS COLD FRONT NEARS THE COAST WITH SW WINDS MAINLY 15-20 KT AND SEAS BUILDING TO 3-5 FT OVERNIGHT. LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3 AM MON...ELEVATED SEAS AND GUSTY SWLY WINDS WILL START OFF THE PERIOD TUE...AS A WEAK AREA OF LOW PRESSURE WILL LIFT NORTH THROUGH THE WATERS...WITH A WEAK COLD FRONT MOVING THROUGH TUE AFTERNOON. SW WINDS 15-25KT AND SEAS 4-7FT LIKELY TUE...WITH A PERIOD OF SCA CONDITIONS EXPECTED. WINDS BRIEFLY BECOME W 5-15 KT TUE NIGHT WITH SEAS SUBSIDING TO 3-5 FT. HOWEVER...WINDS QUICKLY BACK TO SW AND INCREASE TO 15-25 KT WED AHEAD OF A SECONDARY FRONT PROGGED TO MOVE ACROSS THE WATERS WED AFTERNOON/EVENING. STRONGER CAA BEHIND THIS FRONT WILL KEEP WINDS GUSTY...NW AROUND 15-25 KT...INTO THU MORNING. SEAS GENERALLY 3-6 FT WED INTO THU MORNING. WILL CONTINUE TO DISCOUNT THE OPERATIONAL ECMWF SOLUTION OF LIFTING ANOTHER LOW PRES AREA THURS AS THIS SOLUTION IS AN OUTLIER. WINDS BACK TO SW AND INCREASE TO 15-25 KT WITH SEAS INCREASING TO 4-6 FT FRI AHEAD OF YET ANOTHER FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...RSB/BTC SHORT TERM...BTC LONG TERM...SK/CQD AVIATION...BTC/LEP MARINE...RSB/BTC/SK/CQD
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
117 PM CST MON JAN 13 2014 .UPDATE... ISSUED AT 117 PM CST MON JAN 13 2014 LOWER LEVELS BENEATH WEAK RADAR ECHOES ACROSS EASTERN ND FINALLY SATURATED ENOUGH TO SEE SOME LIGHT SNOW AND 4 SM FROM JAMESTOWN TO OAKES...SO KEPT LOW POPS ACROSS PORTIONS OF SOUTHEAST ND THROUGH 21 UTC. OTHERWISE...REMOVED ALL POPS THROUGH 00 UTC AS HIGH RESOLUTION MODELS CONTINUE TO SLOW ONSET OF SNOW LATE THIS AFTERNOON AND TONIGHT. WILL ALSO KEEP SCATTERED FLURRIES ACROSS WEST CENTRAL MN THROUGH 21 UTC. TEMPERATURES MORE OR LESS ON TRACK WITH NO CHANGES AT THIS TIME. UPDATE ISSUED AT 1017 AM CST MON JAN 13 2014 CHALLENGE FOR THE UPDATE INCLUDES TIMING OF SNOW LATER TODAY AND TEMPERATURES. SHORT-WAVE IN NORTHWEST FLOW ALOFT JUST ENTERING CENTRAL ALBERTA AND WILL SWEEP ACROSS THE NORTHERN PLAINS BY 06 UTC TONIGHT. LIGHT RADAR ECHOES ACROSS CENTRAL ND PICKING UP INCREASING MID-LEVEL CLOUDS...BUT NO PRECIPITATION IS BEING REPORTED AT THE SURFACE. LATEST RAP/HRRR HAVE DELAYED ONSET OF SNOW ACROSS EASTERN ND UNTIL AFTER 21 UTC...SO HAVE BACKED OFF ON LIKELY POPS LATE THIS AFTERNOON AND FOCUSED THEM MORE TOWARDS 00 UTC AND BEYOND. CURRENT ADVISORY LOOKS GOOD WITH NO CHANGES AT THIS TIME. WILL KEEP FLURRY MENTION ACROSS THE NORTHERN VALLEY INTO NORTHWEST MN THROUGH EARLY AFTERNOON COINCIDENT WITH BAND OF LOW STRATUS. WITH INCREASING CLOUD COVER FROM THE WEST IN THE WAKE OF LAST NIGHT/S FRONTAL PASSAGE...DON/T EXPECT TEMPERATURES TO STRAY TOO FAR FROM CURRENT OBSERVATIONS. THE EXCEPTION BEING FOR THE DEVILS LAKE BASIN AND AREAS WEST OF THE VALLEY WHERE INCREASING LOW-LEVEL WARM AIR ADVECTION SHOULD BRING CURRENT TEMPERATURES IN THE SINGLE DIGITS INTO THE TEENS TO NEAR 20 DEGREES IN SOME LOCATIONS. UPDATED HOURLY CURVE WITH LATEST RAP GUIDANCE WHICH SEEMS TO BE HANDLING CURRENT CONDITIONS BEST. UPDATE ISSUED AT 630 AM CST MON JAN 13 2014 WILL ADD A FEW FLURRIES THIS MORNING BEHIND THE COLD FRONT...OTHERWISE NO CHANGES PLANNED. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 330 AM CST MON JAN 13 2014 A VERY ACTIVE WEATHER PATTERN THROUGH THURSDAY WILL BE THE CHALLENGES THIS MORNING. MODELS ARE IN DECENT AGREEMENT OVERALL...AND CONTINUE TO PREFER THE GFS FOR THE DETAILS. FOR TODAY THROUGH TUESDAY...EXPECT LIGHT SNOW TO DEVELOP THIS AFTERNOON IN THE WEST THEN SPREAD EAST OVERNIGHT. AN AREA OF LOW PRESSURE AND MID LEVEL FRONTOGENESIS WILL CAUSE SOME AREAS OF MODERATE SNOW OVERNIGHT...MAINLY IN SE ND INTO WC MN. IN ADDITION...925MB WINDS WILL INCREASE AFTER 06Z TUE IN THIS SAME AREA AND PRODUCE CONSIDERABLE BLOWING/DRIFTING SNOW. THERE SHOULD BE A BAND OF 1-2 INCHES WITH LOCALIZED AMOUNTS OF 3 INCHES...ALONG WITH INCREASING WINDS. WE WILL ISSUE A WINTER WEATHER ADVISORY FOR THIS AREA WITH THE COMBINATION OF SNOW/BLOWING SNOW. THE TUESDAY MORNING COMMUTE WOULD BE IMPACTED THE MOST IN THE SOUTH VALLEY...WHERE VSBY SHOULD BE REDUCED TO UNDER ONE HALF MILE IN OPEN COUNTRY ALONG WITH SNOW COVERED ROADS. THERE WILL BE LIGHTER SNOW AMOUNTS TO THE NORTH AND EAST WITH THIS SYSTEM...WITH LITTLE TO NO SNOW NEAR BDE. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 330 AM CST MON JAN 13 2014 FOR TUE NIGHT...MOST OF THE NIGHT SHOULD REMAIN DRY AND COOL...WITH CHANCES INCREASING FOR SOME LIGHT SNOW LATE IN THE DVL BASIN. ON WEDNESDAY AND WED NIGHT...A BAND OF SNOW/SLEET AND FREEZING RAIN SHOULD QUICKLY MOVE FROM WEST TO EAST IN STRONG WAA. SOUTHERLY WINDS WILL ALSO INCREASE AND COULD PRODUCE AREAS OF BLOWING SNOW IN THE VALLEY. TEMPS SHOULD WARM BY AFTERNOON TO NEAR OR EVEN ABOVE FREEZING WITH FAVORABLE CHINOOK FLOW INTO WED NIGHT. WESTERLY WINDS WILL INCREASE WED NIGHT AND BECOME VERY GUSTY. WILL MENTION SOME BLOWING SNOW AND WE WILL CONTINUE TO MONITOR THIS TIMEFRAME AND ISSUE ANOTHER SPS. THURSDAY-SUNDAY...THE GFS/ECMWF CONTINUE TO BE VERY CONSISTENT IN THEIR SOLUTIONS FOR THURSDAY. BOTH SHOW THE SFC LOW NEAR WESTERN LAKE SUPERIOR AT 12Z BEFORE SHIFTING EAST. THE GFS IS STILL A LITTLE FASTER WITH THE SECONDARY WAVE AND STRONGER COLD PUSH COMPARED WITH THE ECMWF. THUS...SOME UNCERTAINTY IN THE EXACT TIMING REMAINS. THE GFS CONTINUES TO SHOW 40-50 KT NORTH WINDS AT 925 MB UP THE VALLEY AT 12-18Z...WITH THE STEEPER 1000-850 MB LAPSE RATES COINCIDENT WITH THE SOUTHWARD PUSH OF COLD ADVECTION...JUST IN ADVANCE OF THE STRONG SFC PRESSURE RISES DURING THE MORNING. THE ECMWF IS ABOUT 6-12 HOURS SLOWER...WITH SLIGHTLY WEAKER WIND FIELDS. NEVERTHELESS...THE POTENTIAL STILL EXISTS FOR BLOWING SNOW/BLIZZARD CONDITIONS WITH GUSTS OVER 50 MPH...AND SOME LIGHT SNOW. THE REMAINDER OF THE PERIOD LOOKS PRETTY QUIET. THE INITIAL AMPLIFIED NORTHWEST FLOW PATTERN ACROSS THE PLAINS WILL RELAX HEADING INTO THE WEEKEND...WITH MODERATING TEMPS. NO STRONG MODEL SIGNAL FOR PRECIP EXISTS FRIDAY-SUNDAY...BUT GIVEN THE NORTHWEST FLOW PATTERN...ANY EMBEDDED IMPULSE COULD PRODUCE LIGHT SNOW. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 117 PM CST MON JAN 13 2014 MVFR STRATOCU OVER THE RED RIVER VALLEY INTO NORTHWESTERN MINNESOTA HAS BEEN SLOWLY DIMINISHING AND WILL CONTINUE TO SCATTER OUT THIS AFTN. MID LEVEL CLOUDS AHD OF NEXT SYSTEM FROM SASK INTO CNTRL ND WILL SPREAD EAST MID TO LATE AFTN-EVE. TIMING OF LIGHT SNOW ARRIVAL IS QUESTIONABLE AND PUSHED BACK SNOW TIMING A BIT IN TAFS FROM 12Z SET. VSBYS WILL BE THE MAIN ISSUE WITH WIDESPREAD 3-5SM LIGHT SNOW WITH AREAS OF UNDER 3SM DVL-FAR THIS EVENING- OVERNIGHT. GUSTY NORTHWEST WINDS OVERNIGHT TO 25 KTS OR HIGHER DVL-FAR MAY PRODUCE VSBYS BLO 1 SM AT TIMES LATE TONIGHT INTO TUESDAY MORNING. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST TUESDAY FOR NDZ014-024-028-029-038-039-049-052-053. MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST TUESDAY FOR MNZ003-029-030-040. && $$ UPDATE...ROGERS SHORT TERM...DK LONG TERM...DK/MAKOWSKI AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1220 PM CST MON JAN 13 2014 .UPDATE... ISSUED AT 1214 PM CST MON JAN 13 2014 GUSTY WINDS ACROSS THE SOUTHWEST IN THE WARM SECTOR ARE SLOW TO INCREASE EVEN THOUGHT RUC MODEL H850 WINDS ARE FORECAST TO 55 KTS THERE. THIS AREA WILL BE TOUCH AND GO THIS AFTERNOON AS TO WEATHER THE LINK CAN BE ESTABLISHED TO THE SURFACE. IT MAY BE THE WINDS WILL PICK UP WITH PRESSURE BUBBLE THIS EVENING AS THE COLD FRONT MOVES THROUGH. RATHER THAN DELAY THE WARNING DUE TO THE EARLY UNCERTAINTY WILL LEAVE HEADLINES AS IS. SKIES ARE CLEARING ACROSS WEST CENTRAL NORTH DAKOTA...A TEMPORARY FEATURE THIS AFTERNOON THAT SHOULD CLOUD BACK UP. UPDATE ISSUED AT 929 AM CST MON JAN 13 2014 COMPLEX FORECAST TODAY DEALING WITH SEVERAL AIR MASSES. SURFACE TROUGH OF LOW PRESSURE AND ASSOCIATED WARM FRONT EXTENDED ACROSS WESTERN NORTH DAKOTA. LIGHT SNOW SO FAR HAS BEEN SLOW TO DEVELOP EAST OF THE WARM FRONT. MAY NEED TO WAIT FOR THE COLD FRONT ARRIVAL TO AID IN THE SNOW DEVELOPMENT LATE THIS AFTERNOON. CURRENTLY THE STRONGEST SURFACE WINDS REMAIN ACROSS SOUTHWEST AND CENTRAL MONTANA. CURRENT THINKING IS A BAND OF STRONG WINDS WILL ARRIVE ACROSS SOUTHWEST NORTH DAKOTA EARLY THIS AFTERNOON AS THIS MILD MIXED LAYER MOVES OFF THE HIGH PLAINS OF MONTANA INTO SOUTHWEST NORTH DAKOTA. A SECONDARY PUSH OF STRONG WINDS IS EXPECTED TO ARRIVE ACROSS THE NORTHWEST LATE THIS AFTERNOON AND OVERNIGHT AS THE ABOVE MENTIONED COLD FRONT PUSHES ACROSS THE STATE. TRENDED THE EARLY HIGH POPS LOWER THIS MORNING WEST AND CENTRAL. UPDATE ISSUED AT 704 AM CST MON JAN 13 2014 NO SIGNIFICANT UPDATES TO THE EARLY MORNING FORECAST OTHER THAN POPULATING THE LATEST SENSIBLE WEATHER ELEMENTS AND INTERPOLATING THROUGH MID MORNING. BOWMAN RADAR INDICATES INCREASING REFLECTIVITIES OVER SOUTHWEST NORTH DAKOTA WHICH WILL TRANSLATE EAST THROUGH THE MORNING AND EARLY AFTERNOON. OUR CLIPPER OVER CENTRAL ALBERTA IS FORECAST TO DROP SOUTHEAST INTO NORTH CENTRAL NORTH DAKOTA BY LATE THIS AFTERNOON AND TO THE SOUTHERN JAMES RIVER VALLEY BY EARLY THIS EVENING. WINDS ARE EXPECTED TO INCREASE IN THE WEST AROUND MID-DAY AND OVER THE CENTRAL THIS EVENING. THE BEST CHANCE FOR ACCUMULATING SNOW WILL BE ALONG THE PATH OF THE CLIPPER LATE THIS AFTERNOON AND TONIGHT. THUS CURRENT HEADLINES REMAIN VALID WITH NO CHANGES AT THIS TIME. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 446 AM CST MON JAN 13 2014 SEVERAL HIGHLIGHTS SURROUND THE SHORT TERM PERIOD. MOST OF THE HIGH WIND WATCH WAS UPGRADED TO A HIGH WIND WARNING. A PORTION OF IT WAS REPLACED BY A WIND ADVISORY. A WINTER WEATHER ADVISORY FOR BLOWING SNOW WAS HOISTED FOR PORTIONS OF CENTRAL NORTH DAKOTA INCLUDING THE JAMES RIVER VALLEY MONDAY EVENING THROUGH MONDAY NIGHT. VERY STRONG NORTHWEST WINDS REMAIN ON TRACK TO DEVELOP ACROSS PORTIONS OF THE WEST AND SOUTHWEST BY LATE MORNING/EARLY AFTERNOON...AND CONTINUING TO EXPAND NORTH AND INTENSIFY THROUGH MONDAY EVENING. THE DECIDING FACTOR ON THE HIGH WIND WARNING EVENTUALLY CAME DOWN TO THE HOURLY BUFKIT SOUNDINGS WHICH GAVE BETTER DETAIL ON THE MOMENTUM TRANSFER TO THE SURFACE. ENOUGH EVIDENCE HERE TO ISSUE A HIGH WIND WARNING...MORE SO FOR A SUSTAINED WIND TO 40 MPH. STILL EXPECT GUSTS TO REACH 50 TO 55 MPH...BUT FEEL WIDESPREAD WARNING WINDS OF 58 MPH WILL FALL SHY. A LARGE 6HR PRESSURE RISE OF 14 MB/COLD AIR ADVECTION MONDAY EVENING/NIGHT...WILL BE ENOUGH TO TRANSFER ENOUGH OF THE STRONG WINDS ALOFT TO THE SURFACE. HENCE THE HIGH WIND WATCH WAS UPGRADED. ALTHOUGH THE SOUTHWEST WILL SEE THE STRONGEST WINDS FIRST...THE NORTHWEST AND NORTH CENTRAL WILL EXPERIENCE THE STRONGEST WINDS MONDAY EVENING INTO MONDAY NIGHT. FORECAST WINDS OF 30 MPH SUSTAINED AND GUSTS TO 45 MPH FROM MERCER COUNTY SOUTH TO SIOUX COUNTY PROMPTED A WIND ADVISORY MONDAY EVENING THROUGH MONDAY NIGHT. THE HIGH WIND WATCH WAS REPLACED BY A WIND ADVISORY HERE. CONCERNING THE WINTER WEATHER ADVISORY FOR BLOWING SNOW. THE DECISION HERE WAS BASED ON SUCCESSIVE TRENDS BY THE MODELS TO SHOW A SHIFT FARTHER SOUTH FOR LIGHT SNOW DEVELOPING MONDAY AFTERNOON THROUGH MONDAY EVENING. WITH AROUND AN INCH OF SNOWFALL EXPECTED IN CONJUNCTION WITH THE DEVELOPMENT OF STRONG NORTHWEST WINDS OF 25 TO 40 MPH...FELT THAT VISIBILITIES WILL HAVE A GOOD POTENTIAL FOR BEING REDUCED TO ONE HALF MILE. THE SNOW WILL DIMINISH BEFORE THE WINDS WILL TONIGHT...THUS EXPECTATIONS ARE THAT AT SOME POINT IN THE LATE EVENING OR OVERNIGHT PERIOD...THE WINTER WEATHER ADVISORY WILL BE REPLACED BY A WIND ADVISORY. EXPECT LIGHT SNOW TO DEVELOP EARLY THIS MORNING WEST AND GRADUALLY INCREASE IN AREAL COVERAGE THROUGH THE MORNING. THIS AREA WILL TRANSLATE EAST ALONG A FRONTAL BOUNDARY MOVING INTO CENTRAL NORTH DAKOTA MONDAY AFTERNOON. A SURFACE LOW PRESSURE OVER SASKATCHEWAN WILL PROPAGATE SOUTHEAST ALONG THE FRONT THIS AFTERNOON AND INTO THE JAMES RIVER VALLEY BY 00Z TUESDAY. LOW LEVEL CONVERGENCE IN CONJUNCTION WITH LARGE SCALE LIFT VIA THE LEFT EXIT REGION OF A 120KT JET STREAK AND THE APPROACH OF A SHORTWAVE ALOFT WILL BE ENOUGH TO GENERATE THE AREA OF SNOW AND GUSTY WINDS/BLOWING SNOW MONDAY EVENING INTO MONDAY NIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 446 AM CST MON JAN 13 2014 THE MAIN IMPACT IN THE LONG TERM PERIOD WILL BE STRONG WINDS AND SNOW SHOWERS ASSOCIATED WITH A STRONG CLIPPER THAT TRACKS FROM CENTRAL CANADA INTO THE NORTHERN GREAT LAKES REGION WEDNESDAY THROUGH THURSDAY. ON TUESDAY WE WILL BE DEALING WITH SOME RESIDUAL BLOWING SNOW AND STRONG NORTHWEST WINDS ASSOCIATED WITH THE CLIPPER EXITING THE AREA AT THE END OF THE SHORT TERM PERIOD. KEPT A MENTION OF BLOWING SNOW THROUGH THE MORNING ON TUESDAY. WINDS DIMINISH QUICKLY TUESDAY AFTERNOON AND EVENING...THEN SHIFT WEST TO SOUTHWEST LATE TUESDAY NIGHT AS THE NEXT CLIPPER DROPS SOUTHEAST THROUGH THE SOUTHERN CANADIAN PROVINCES. WE SEE A PERIOD OF STRONG WARM ADVECTION/ISENTROPIC UPGLIDE LATE TUESDAY NIGHT INTO WEDNESDAY MORNING...RESULTING IN A BAND OF MIXED PRECIPITATION DEVELOPING OVER THE NORTHWEST AND MOVING ACROSS THE NORTH CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA. STRONG SUBSIDENCE DEVELOPS BY WEDNESDAY AFTERNOON AS THE DRY SECTOR OF THE CLIPPER TRACKS ACROSS THE FORECAST AREA. WE ALSO SEE AN INCREASE IN GRADIENT WINDS BETWEEN THE CLIPPER AND BUILDING HIGH PRESSURE TO THE WEST...AND VERY STRONG WINDS ALOFT MOVING INTO THE AREA. PRESSURE RISES CONTINUE THROUGH THE EVENING...BUT THE VERY LARGE PRESSURE RISES DO NOT ARRIVE UNTIL LATE WEDNESDAY NIGHT BEHIND A SECONDARY COLD FRONT THAT DROPS SOUTH THROUGH THE AREA. STRONG COLD ADVECTION WILL ALSO ACCOMPANY THE SECONDARY COLD FRONT...ALONG WITH COLD ADVECTION SNOW SHOWERS. WEDNESDAY NIGHT THROUGH THURSDAY MORNING LOOKS TO BE THE PERIOD OF STRONGEST WINDS ACROSS THE FORECAST AREA. IN ADDITION...ANY SNOW SHOWERS THAT ACCOMPANY THE WINDS WOULD GREATLY REDUCE VISIBILITIES. WINDS ARE EXPECTED TO DIMINISH THROUGH THE MORNING IN THE WEST...BUT REMAIN STRONG THROUGH THE DAY ALONG AND EAST OF THE HIGHWAY 83 CORRIDOR. WE WILL CONTINUE TO ADVERTISE THIS SYSTEM IN THE HWO...AND HAVE ADDED BLOWING SNOW TO THE FORECAST WEDNESDAY NIGHT AND THURSDAY WHERE WE HAVE A CHANCE OF SNOW. WITH OUR CURRENT COMPLICATED HEADLINES IN THE SHORT TERM PERIOD...WILL NOT ISSUE ANY HEADLINES REGARDING THIS SYSTEM AT THIS TIME. SOME UNCERTAINTY STILL REMAINS....BUT IF CURRENT MODEL SOLUTIONS HOLD...WE WOULD EXPECT WIND HEADLINES WITH THIS SYSTEM WEDNESDAY AFTERNOON THROUGH THURSDAY AFTERNOON...AND POSSIBLY BLOWING SNOW OR EVEN BLIZZARD HEADLINES IN AREAS OF SNOW SHOWERS WEDNESDAY NIGHT INTO THURSDAY. WE REMAIN IN NORTHWEST FLOW PATTERN WITH SEASONABLE TEMPERATURES THROUGH THE REMINDER OF THE EXTENDED PERIOD. A COUPLE OF WAVES TRANSLATING THROUGH THE FLOW COULD BRING A BRIEF SHOT OF LIGHT SNOW...BUT CURRENTLY...NO SIGNAL IS STRONG ENOUGH TO RESULT IN A MENTION OF PRECIPITATION AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1214 PM CST MON JAN 13 2014 A WARM FRONT FROM KMBG MOBRIDGE THROUGH CYEN ESTEVAN AS OF 18 UTC WILL CONTINUE TO MOVE EAST THROUGH THE AFTERNOON AND EVENING. A BAND OF LIGHT SNOW WITH IFR CONDITIONS AND STRONG NORTHWEST WINDS WILL ALSO DEVELOP ACROSS THE AREA LATE THIS AFTERNOON AND INTO THE EVENING. WIND GUSTS OF 40+ KTS ARE EXPECTED. && .BIS WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 6 PM CST /5 PM MST/ THIS EVENING TO 6 AM CST /5 AM MST/ TUESDAY FOR NDZ019-020-034-042-045. HIGH WIND WARNING UNTIL 6 AM CST /5 AM MST/ TUESDAY FOR NDZ017- 018-031>033-040-041-043-044. HIGH WIND WARNING FROM 6 PM THIS EVENING TO 6 AM CST TUESDAY FOR NDZ001>003-009>011. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM CST TUESDAY FOR NDZ012-013-021>023-025-035>037-046>048-050-051. && $$ UPDATE...WAA SHORT TERM...KS LONG TERM...TWH AVIATION...AYD
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1017 AM CST MON JAN 13 2014 .UPDATE... ISSUED AT 1017 AM CST MON JAN 13 2014 CHALLENGE FOR THE UPDATE INCLUDES TIMING OF SNOW LATER TODAY AND TEMPERATURES. SHORT-WAVE IN NORTHWEST FLOW ALOFT JUST ENTERING CENTRAL ALBERTA AND WILL SWEEP ACROSS THE NORTHERN PLAINS BY 06 UTC TONIGHT. LIGHT RADAR ECHOES ACROSS CENTRAL ND PICKING UP INCREASING MID-LEVEL CLOUDS...BUT NO PRECIPITATION IS BEING REPORTED AT THE SURFACE. LATEST RAP/HRRR HAVE DELAYED ONSET OF SNOW ACROSS EASTERN ND UNTIL AFTER 21 UTC...SO HAVE BACKED OFF ON LIKELY POPS LATE THIS AFTERNOON AND FOCUSED THEM MORE TOWARDS 00 UTC AND BEYOND. CURRENT ADVISORY LOOKS GOOD WITH NO CHANGES AT THIS TIME. WILL KEEP FLURRY MENTION ACROSS THE NORTHERN VALLEY INTO NORTHWEST MN THROUGH EARLY AFTERNOON COINCIDENT WITH BAND OF LOW STRATUS. WITH INCREASING CLOUD COVER FROM THE WEST IN THE WAKE OF LAST NIGHT/S FRONTAL PASSAGE...DON/T EXPECT TEMPERATURES TO STRAY TOO FAR FROM CURRENT OBSERVATIONS. THE EXCEPTION BEING FOR THE DEVILS LAKE BASIN AND AREAS WEST OF THE VALLEY WHERE INCREASING LOW-LEVEL WARM AIR ADVECTION SHOULD BRING CURRENT TEMPERATURES IN THE SINGLE DIGITS INTO THE TEENS TO NEAR 20 DEGREES IN SOME LOCATIONS. UPDATED HOURLY CURVE WITH LATEST RAP GUIDANCE WHICH SEEMS TO BE HANDLING CURRENT CONDITIONS BEST. UPDATE ISSUED AT 630 AM CST MON JAN 13 2014 WILL ADD A FEW FLURRIES THIS MORNING BEHIND THE COLD FRONT...OTHERWISE NO CHANGES PLANNED. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 330 AM CST MON JAN 13 2014 A VERY ACTIVE WEATHER PATTERN THROUGH THURSDAY WILL BE THE CHALLENGES THIS MORNING. MODELS ARE IN DECENT AGREEMENT OVERALL...AND CONTINUE TO PREFER THE GFS FOR THE DETAILS. FOR TODAY THROUGH TUESDAY...EXPECT LIGHT SNOW TO DEVELOP THIS AFTERNOON IN THE WEST THEN SPREAD EAST OVERNIGHT. AN AREA OF LOW PRESSURE AND MID LEVEL FRONTOGENESIS WILL CAUSE SOME AREAS OF MODERATE SNOW OVERNIGHT...MAINLY IN SE ND INTO WC MN. IN ADDITION...925MB WINDS WILL INCREASE AFTER 06Z TUE IN THIS SAME AREA AND PRODUCE CONSIDERABLE BLOWING/DRIFTING SNOW. THERE SHOULD BE A BAND OF 1-2 INCHES WITH LOCALIZED AMOUNTS OF 3 INCHES...ALONG WITH INCREASING WINDS. WE WILL ISSUE A WINTER WEATHER ADVISORY FOR THIS AREA WITH THE COMBINATION OF SNOW/BLOWING SNOW. THE TUESDAY MORNING COMMUTE WOULD BE IMPACTED THE MOST IN THE SOUTH VALLEY...WHERE VSBY SHOULD BE REDUCED TO UNDER ONE HALF MILE IN OPEN COUNTRY ALONG WITH SNOW COVERED ROADS. THERE WILL BE LIGHTER SNOW AMOUNTS TO THE NORTH AND EAST WITH THIS SYSTEM...WITH LITTLE TO NO SNOW NEAR BDE. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 330 AM CST MON JAN 13 2014 FOR TUE NIGHT...MOST OF THE NIGHT SHOULD REMAIN DRY AND COOL...WITH CHANCES INCREASING FOR SOME LIGHT SNOW LATE IN THE DVL BASIN. ON WEDNESDAY AND WED NIGHT...A BAND OF SNOW/SLEET AND FREEZING RAIN SHOULD QUICKLY MOVE FROM WEST TO EAST IN STRONG WAA. SOUTHERLY WINDS WILL ALSO INCREASE AND COULD PRODUCE AREAS OF BLOWING SNOW IN THE VALLEY. TEMPS SHOULD WARM BY AFTERNOON TO NEAR OR EVEN ABOVE FREEZING WITH FAVORABLE CHINOOK FLOW INTO WED NIGHT. WESTERLY WINDS WILL INCREASE WED NIGHT AND BECOME VERY GUSTY. WILL MENTION SOME BLOWING SNOW AND WE WILL CONTINUE TO MONITOR THIS TIMEFRAME AND ISSUE ANOTHER SPS. THURSDAY-SUNDAY...THE GFS/ECMWF CONTINUE TO BE VERY CONSISTENT IN THEIR SOLUTIONS FOR THURSDAY. BOTH SHOW THE SFC LOW NEAR WESTERN LAKE SUPERIOR AT 12Z BEFORE SHIFTING EAST. THE GFS IS STILL A LITTLE FASTER WITH THE SECONDARY WAVE AND STRONGER COLD PUSH COMPARED WITH THE ECMWF. THUS...SOME UNCERTAINTY IN THE EXACT TIMING REMAINS. THE GFS CONTINUES TO SHOW 40-50 KT NORTH WINDS AT 925 MB UP THE VALLEY AT 12-18Z...WITH THE STEEPER 1000-850 MB LAPSE RATES COINCIDENT WITH THE SOUTHWARD PUSH OF COLD ADVECTION...JUST IN ADVANCE OF THE STRONG SFC PRESSURE RISES DURING THE MORNING. THE ECMWF IS ABOUT 6-12 HOURS SLOWER...WITH SLIGHTLY WEAKER WIND FIELDS. NEVERTHELESS...THE POTENTIAL STILL EXISTS FOR BLOWING SNOW/BLIZZARD CONDITIONS WITH GUSTS OVER 50 MPH...AND SOME LIGHT SNOW. THE REMAINDER OF THE PERIOD LOOKS PRETTY QUIET. THE INITIAL AMPLIFIED NORTHWEST FLOW PATTERN ACROSS THE PLAINS WILL RELAX HEADING INTO THE WEEKEND...WITH MODERATING TEMPS. NO STRONG MODEL SIGNAL FOR PRECIP EXISTS FRIDAY-SUNDAY...BUT GIVEN THE NORTHWEST FLOW PATTERN...ANY EMBEDDED IMPULSE COULD PRODUCE LIGHT SNOW. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 630 AM CST MON JAN 13 2014 EXPECT MVFR/VFR CIGS TO PERSIST AT MOST SITES TODAY. THERE WILL BE SNOW AND IFR CONDITIONS OVERSPREADING THE AREA OVERNIGHT...IN ADDITION TO INCREASING NW WINDS IN THE WEST OVERNIGHT AND BLSN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST TUESDAY FOR NDZ014-024-028-029-038-039-049-052-053. MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST TUESDAY FOR MNZ003-029-030-040. && $$ UPDATE...ROGERS SHORT TERM...DK LONG TERM...DK/MAKOWSKI AVIATION...DK
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
418 PM CST MON JAN 13 2014 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 417 PM CST MON JAN 13 2014 CHALLENGING FORECAST THIS EVENING AS MODELS HAVING A PRETTY DIFFICULT TIME DETERMINING PRECIPITATION THREAT TONIGHT. FOR NOW WILL LEAN TOWARDS THE ECMWF AND GFS OUTPUT WHICH CORRELATES MORE TO THE PREVIOUS FORECASTS. MAIN REASONS ARE THAT THE LOW LEVEL WARM ADVECTION IS ALREADY NORTH OF THE CWA AND WILL LIKELY REMAIN SO...SO THE CHANCES FOR PRECIPITATION THIS EVENING WEIGH HEAVILY UPON GETTING ANYTHING TO DEVELOP AS A VORTICITY LOBE MOVES FROM THE WESTERN DAKOTAS INTO CENTRAL SD THIS EVENING. NOT BANKING ON MUCH FROM THIS...ALTHOUGH THE NAM AND RAP ARE PRETTY EXCITED ABOUT PRECIPITATION PRODUCTION WITHIN THIS LOCATION. WITH LITTLE OR NO LOW AND MID LEVEL THERMAL GRADIENT AND A FAIRLY DRY LOWER LAYER PRECIPITATION PRODUCTION SHOULD BE PRETTY DIFFICULT TO COME BY. HAVE BACKED OFF ON POPS WEST OF INTERSTATE 29 THIS AFTERNOON AND EVENING AND LOWERED SNOWFALL AMOUNTS EVERYWHERE. THE LOW LEVEL THERMAL GRADIENT IS FARTHER NORTH AND EAST THAN PREVIOUSLY EXPECTED WHICH HAS ALLOWED THE WARM ADVECTIVE PRECIPITATION TO DEVELOP FARTHER NORTHEAST....WHICH IS RIGHT ON THE 925MB FRONT AND ALREADY MOVING INTO WESTERN MINNESOTA. SO...HAVE MOVED THE START TIME OF THE ADVISORY TO 6Z WHICH CORRELATES MORE TO THE INCREASE IN NORTHWEST WINDS WHICH IF WE HAVE ANY SNOW ON THE GROUND WOULD START TO BLOW AROUND. TEMPERATURES STEADY TO FALLING ON TUESDAY WITH VERY STRONG WINDS. THE WIND ADVISORY FOR THE AREA LOOKS SOLID AND EXPECT GUSTS TO 45 TO 50 MPH AT TIMES...ESPECIALLY IN THE MORNING. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 417 PM CST MON JAN 13 2014 WINDS SHOULD BE ON THE QUICK DOWNTREND ON TUESDAY NIGHT WITH A WEDGE OF CLEARING WORKING ACROSS THE AREA WITH THE HIGH PRESSURE RIDGE AXIS MOVING ACROSS. WINDOW FOR TEMPS TO DROP FAIRLY COOL WITH 925 HPA COLD PUSH -12 TO -16C IN THE EASTERN HALF. SOME LOWS DOWN CLOSER TO ZERO NEAR AND ADVANCE OF RIDGE AXIS...BUT SOME LINGERING GRADIENT IN THE FAR EAST MAY HAVE SOMETHING TO SAY ABOUT THAT...ESPECIALLY IF SHORT TERM SNOWFALL CONTINUES TO LOOK DISAPPOINTING IN TERMS OF AMOUNTS. STRONG WAVE WILL START TO MOVE INTO AREAS NEAR THE NORTHERN PLAINS/CANADIAN BORDER BY WEDNESDAY EVENING. GANGLY WARM FRONT EXTENDING SOUTHWARD WILL TRUDGE EASTWARD ACROSS THE CWA...WITH A CONSENSUS OF NEAR THE I29 CORRIDOR BY 00Z THU. AHEAD OF THE FRONT WILL DEVELOP A STOUT SOUTH TO SOUTHWEST FLOW...WITH A WESTERLY PUSH OF WARMER AIR TO THE WEST OF THE FRONT. NOW LOOKING LIKE THERE WILL BE ENOUGH NET LIFT WITHIN THE WARM FRONTAL ZONE TO WARRANT A CHANCE LEVEL MENTION FOR LIGHT SNOW EVOLVING AS BOUNDARY WORKS EASTWARD ACROSS THE CWA...MAINLY ACROSS THE NORTH WHERE SOME BETTER SUPPORT TO DEEPER DIV Q. SHOULD BE A FAIR AMOUNT OF CLOUDS EARLY ON...BUT SOME CLEARING WORKING IN FROM THE WEST LATER IN THE DAY...OR AT A MINIMUM A THINNING TO HIGHER LEVEL CLOUDS. ONE SHORTCOMING THAT LOOKED TO BE A FACTOR IN THE MODELS WAS ALLOWING TEMPS TO WARM ENOUGH IN THE WARM SECTOR...AND RAISED TEMPS OVER GUIDANCE ONCE AGAIN IN THE WEST...BACK CLOSER TO WHERE PREVIOUS FORECAST RESIDED. STILL LOOKING TO THE WIND THREAT THURSDAY AS THE MOST SIGNIFICANT ISSUE IN THE FORECAST PERIOD. SOMEWHAT LOW CONFIDENCE IN TIMING OF THE ABSOLUTE STRONGEST WINDS TIED TO WHEN LARGEST LOW LEVEL ISENTROPIC SUPPORT FOR SUBSIDENCE WILL INITIATE...WITH UP TO 12H DIFFERENCE BRACKETING SOLUTIONS OF NAM /SLOWEST/ TO GFS /FASTEST/. AT THIS POINT...MAY SEE A LITTLE PARTIAL DECOUPLING IN THE WARM SECTOR OVERNIGHT WHEN LIKELY TO GET SOME CONTINUED RISING TEMPS IN THE EAST FOR A WHILE INTO THE NIGHT. MAY LIMIT SPEED POTENTIAL A BIT...ESPECIALLY AT LOWER ELEVATIONS...BUT WILL NOT TAKE LONG TO GET COUPLING TO KICK IN THOUGH WITH COLD AIR ADVECTION STARTING AFTER 06Z. THIS SHOULD ALSO HELP TO KEEP TEMPS UP ABOVE GUIDANCE WITH MIXING OF +2 TO -2 925 HPA TEMPS EXPECTED THROUGH 12Z. WITH 45 TO 55 KNOTS IN THE MID TO UPPER MIXED LAYER...WOULD PUT PROSPECT OF NEEDING A HIGH WIND WATCH TO BE QUITE HIGH. FOR NOW...WILL WORK THROUGH CURRENT WIND HIGHLIGHTS FIRST BEFORE COMPLICATING MATTERS WITH THE NEXT...BUT CONTINUE TO HIT MENTION HARD IN WEATHER STORY/HWO/SOCIAL MEDIA. HAVE PUSHED MENTION TO LIGHT SNOW UP TOWARD LOWER LIKELY POPS IN THE NORTHEAST HALF OF THE AREA AND TRIED TO TIME WITH AN EC/18Z GFS CONSENSUS...WHICH HAS BEEN TREND IN MAJORITY SOLUTIONS TODAY. WILL HAVE TO WATCH VISIBILITY ISSUES AS WELL...AS WILL BE QUITE LOW AT TIMES OF ANY FALLING SNOW...BUT NOT SURE THERE WILL BE ENOUGH SNOW FROM EARLIER TO MAKE WIDESPREAD BLOWING SNOW A LARGE ENOUGH THREAT. DID CONTINUE MENTION OF SOME PATCHY OF BLOWING SNOW. OTHER CONCERN WILL BE TEMPS STARTING TO FALL DURING THE DAY... WHICH BY EVENING WITH THE STRONG WINDS WILL PRODUCE SOME -20 TO -25 WIND CHILLS IN AT LEAST THE NORTHEASTERN HALF OF THE AREA. COLD AIR DIGS INTO THE EASTERN AREAS ON FRIDAY...AND WILL GO WITH HIGHS IN THE TEENS EAST TO LOWER 30S WEST AS ANOTHER RIDGE AXIS DRIFTS ACROSS THE AREA. LITTLE TO HANG ONES HAT ON AS FAR AS TIMING OR LOCATION OF FEATURES IN THE SATURDAY TO MONDAY TIME FRAME. SHOULD TO CONTINUE TO SEE A CLIPPERY NORTHWEST FLOW...BUT WITH RIDGE AXIS NUDGING EAST...THE SIGNIFICANT PRECIPITATION THROUGH SHOULD REMAIN NORTHEAST OF THE AREA...AND WILL BE LEFT TO A CHASE OF THE POTENTIAL NON DIURNAL TEMPERATURE TRENDS. ONE PERIOD TO WATCH FOR POSSIBLE LIGHT PRECIPITATION WOULD BE LATER FRIDAY NIGHT AND SATURDAY... AND WITH STRONGER WARM AIR ADVECTION IN TYPES OF SYSTEM... WOULD OPEN THE DOOR FOR SOME MIXED TYPE PRECIPITATION IF SUCH A SOLUTION WOULD EVOLVE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1105 AM CST MON JAN 13 2014 NOT MUCH GOING ON THROUGH 0Z/14 AS UPPER LEVEL SUPPORT MOVES INTO THE NORTHERN PLAINS. FORCING AHEAD OF THIS WAVE WILL BEGIN TO PRODUCE LIGHT SNOW OR LIGHT RAIN LIKELY ORIENTED IN A NORTH TO SOUTH BAND WHICH WILL DRIFT NORTHEAST THROUGH THE NIGHT. THE BEST CHANCE FOR THIS PRECIPITATION IN THE FSD CWA WILL BE FROM ABOUT 0Z THROUGH 6Z. AFTER 6Z NORTHWEST WINDS WILL INCREASE SIGNIFICANTLY WITH SOME GUSTS TO 45 MPH LIKELY. PATCHY LIGHT SNOW WILL ALSO BE POSSIBLE...ESPECIALLY IN SOUTHWEST MINNESOTA...WHICH COULD CAUSE SOME REDUCTIONS IN VISIBILITY IN THE SNOW AND BLOWING SNOW. THE MAIN THREAT FOR THIS SHOULD BE FROM ABOUT 10Z THROUGH 18Z TUESDAY. MVFR CONDITIONS ARE LIKELY WITH THIS EVENT WITH SOME VISIBILITIES POSSIBLY FALLING TO IFR. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM CST TUESDAY FOR SDZ038-039-050-052>071. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM CST TUESDAY FOR SDZ040. MN...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM CST TUESDAY FOR MNZ098. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM CST TUESDAY FOR MNZ071-072-080-081-089-090-097. IA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM CST TUESDAY FOR IAZ001>003-012>014-020>022-031-032. NE...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM CST TUESDAY FOR NEZ013-014. && $$ SHORT TERM...08 LONG TERM...CHAPMAN AVIATION...08