Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/15/14


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...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 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 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 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 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
910 PM EST TUE JAN 14 2014 .UPDATE... CURRENT...WHILE THE SURFACE COLD FRONT HAS SAGGED SOUTH OF THE LAKE OKEE REGION THIS EVENING...THE BACK EDGE OF MID/UPPER CLOUD SHIELD CONTINUES TO BE PAINFULLY SLOW TO ERODE AND EDGE S/E. LAST FEW IR IMAGES SHOW SIGNIF BREAKS CONFINES TO LAKE/VOLUSIA COS...WHICH ISN`T A WHOLE LOT OF PROGRESS SINCE EARLY AFTERNOON. OTHERWISE...WEAK CAA PATTERN NOW IN PLACE WITH LIGHT NW WINDS AND TEMPS RANGING FROM THE U50S/L60S N/W TO THE U60S/L70S S/E. REMAINDER OF TONIGHT...BASED ON ANLYS OF WATER VAPOR AND RUC UPPER WIND/RH FIELDS AND THE LATEST MODEL RH GUIDANCE PROGS...HIGHER LEVEL CLOUDS AND MOISTURE WILL BE TOUGH TO DISLODGE ACROSS THE CENTRAL AND SRN CWA...AS A REINFORCING SHORT WAVE TROUGH DIGGING TOWARD THE SERN CONUS WILL ACTUALLY BACK THE H50-H30 MEAN WINDS SLIGHTLY. THUS... EXPECT MOST AREAS THAT ARE CLOUDY-MCLDY ATTM TO REMAIN SO OVERNIGHT. NOT A WHOLE LOT OF CHANGE TO THE GRIDS. TWEAKED SKY COVERAGE UP BY ABOUT 20-30 PCT ACROSS THE CENTRAL-SOUTH...AND ALSO NUDGED MINS UP BY A COUPLE DEGREES. && .AVIATION...VFR. CIGS GENERALLY AOA FL100 NORTH OF KISM-KTIX... CIGS BKN050-080 LCLY OVC TO THE SOUTH. && .MARINE...LIGHT NW FLOW AT OR BELOW 10KT WITH SEAS 2-3FT NEAR SHORE AND 3-4FT WELL OFFSHORE. NO HEADLINES FOR WIND/SEAS. && FORECAST/AVIATION...CRISTALDI IMPACT WX UPDATES...WEITLICH && .PREV DISCUSSION... /ISSUED 315 PM EST TUE JAN 14 2014/ WEDNESDAY...A REINFORCING SHORT WAVE PUSHING INTO THE MID SOUTH/MS VALLEY WILL PREVENT THE H100-H85 FLOW OVER CENTRAL FL FROM BACKING TO THE S WHERE IT MIGHT BE ABLE TO GENERATE ANY RESPECTABLE AMOUNT OF WARM AIR OR MOISTURE ADVECTION. FCST FOR WED WILL BE DRY... UNDERCUTTING 12Z GFS MOS POPS BY 15-40PCT. COOL AIR ADVECTION GENERATED BY THE W/NW FLOW WILL KEEP MAX TEMPS NEAR OR SLIGHTLY BLO AVG...M/U60S ALONG AND N OF THE I-4 CORRIDOR...U60S/L70S SPACE AND TREASURE COAST. WED NIGHT-THU NIGHT...HIGH AMPLITUDE UPPER RIDGE OVER THE EASTERN PACIFIC AND U.S. WEST COAST MOVES LITTLE DURING THIS 24 TO 60 HOUR PERIOD. TO THE EAST...DEEP NORTH SOUTH ORIENTED TROUGHING EXTENDS FROM NORTH OF HUDSON BAY IN CANADA TO THE MID WEST. UPPER LEVEL IMPULSES THAT RIDE OVERTOP OF THE UPPER RIDGE OVER THE EASTERN PACIFIC AND U.S. WEST COAST DIVE SOUTHEASTWARD OVER THE NATIONS MID SECTION...HELP TO DIG THE BASE OF THE LONG TROUGH PATTERN OVER CANADA AND THE U.S. MIDWEST FURTHER SOUTH INTO THE SOUTHEAST U.S. AND INTO THE FLORIDA PENINSULA. THE RESULTING PERSISTENT NORTHWEST WINDFLOW PULL CONTINENTAL COLD AIR MASS OVER THE SOUTHEAST AND INTO FLORIDA. MOSTLY CLEAR SKIES DURING THE DAY AND OVERNIGHT ALLOW FOR EXCELLENT RADIATIONAL COOLING STARTING LATE AFTERNOON AND CONTINUING THROUGH THE EVENING. TEMPERATURES FALL THROUGH THE 60S AND 50S WEDNESDAY EVENING AND FIRST PART OF THE OVERNIGHT HOURS AND BOTTOM OUT IN THE LOW 30S NORTH OF INTERSTATE 4 TO THE MID AND UPPER 30S DOWN TO LAKE OKEECHOBEE AND EAST TO THE INTERSTATE 95 U.S. 1 CORRIDOR. THESE COLD TEMPERATURES COMBINED WITH WEST TO NORTHWEST WINDS 5 TO 10 MPH SHOULD PRODUCE WIND CHILL VALUES RANGING FROM THE MID 20S NORTH AND WEST OF INTERSTATE 4 TO THE MID AND UPPER 20S INTERSTATE 4 SOUTH TO LAKE OKEECHOBEE EAST TO THE COAST VOLUSIA...BREVARD AND INDIAN RIVER COUNTY COAST AND THE LOW 30S AT THE COAST FROM FORT PIERCE SOUTH. STEADY NORTHWEST WINDS CONTINUE TO FEED A COLD AIR MASS INTO CENTRAL FLORIDA THURSDAY WITH HIGHS IN THE LOW 50S NORTH OF INTERSTATE 4 TO AROUND 60 IN THE INDIANTOWN STUART AREAS IN MARTIN COUNTY. A CHILLY/COLD DAY WILL GIVE A HEAD START TO BY FAR THE COLDER OF THE TWO NIGHTS. PERSISTENT WEST TO NORTHWEST WINDS AND ANOTHER AREA OF COLD DRY AIR BEHIND ANOTHER FRONT ROTATING AROUND THE BASE OF THE LONG MID LEVEL TROUGHING PATTERN OVER THE SOUTHEAST U.S. AND FLORIDA IS FORECAST TO PRODUCE EVEN COLDER TEMPERATURES OVERNIGHT WED AND EARLY THU MORNING. MID AND UPPER 30S ARE FORECAST FOR MOST OF EAST CENTRAL FLORIDA WITH COLDER LOWER 30S FROM CENTRAL OSCEOLA TO OKEECHOBEE COUNTY AND WEST OF INTERSTATE 95 FROM SOUTHWEST BREVARD TO CENTRAL AND WESTERN MARTIN COUNTY. STRONGER WINDS BEING FORECAST COMBINE WITH THESE COLDER TEMPERATURES TO PRODUCE AFTER MIDNIGHT WED/THU WIND CHILL VALUES IN THE MID AND UPPER 20S FROM CENTRAL OSCEOLA TO OKEECHOBEE COUNTY AND WEST OF INTERSTATE 95 FROM SOUTHWEST BREVARD TO CENTRAL AND WESTERN MARTIN COUNTY. LATE NIGHT WIND CHILLS FROM ORLANDO NORTH AND ALONG THE COAST ARE FORECAST TO BE IN THE LOW 30S. ANYONE HAVING TO BE OUTSIDE THESE TWO NIGHTS SHOULD DRESS IN LAYERS. ALSO REMEMBER TO COVER COLD SENSITIVE PLANTS WITH CLOTH SHEETS AND TO BRING IN PETS AND PUT LIVE STOCK IN SOME FORM OF SHELTER. PREVIOUS EXTENDED...MIGRATION SWD OF ANOTHER UPR CYCLONE FROM THE CANADIAN PRAIRIES TO NEAR THE GRT LAKES REGION LATE IN THE WORKWEEK WL CONTINUE A GENERAL SUPPLY OF COOL TO COLD CONTINENTAL AIR TO THE TN VALLEY AND EVENTUALLY FL PENINSULA FRI. THE SURGE MAY BE ACCOMPANIED BY SOME INCRSG CLOUDINESS BUT AMBIENT AIRMASS LOOKS TOO DRY TO SUPPORT PCPN AT GROUND LEVEL. TEMPS GENERALLY 5 TO 10 DEGREES BLO NORMAL TO ROUND OUT THE END OF THE WEEK. NO PCPN IN THE FORECAST THROUGH EARLY NEXT WEEK WITH A WARMING TREND FROM MONDAY ONWARD. && .AVIATION...N OF KTIX-KISM...THRU 15/00Z WRLY SFC WNDS G18-22KTS BCMG W/NW AOB 10KTS WITH PREVAILING CIGS BTWN FL080-100...BRIEF MVFR CIGS BTWN FL020-030. AFT 15/00Z...W/NW SFC WNDS AOB 10KT WITH VFR CIGS/VSBYS. SOUTH OF KTIX-KISM...THRU 15/00Z OCNL W/SW SFC WND G18-22KTS WITH PREVAILING CIGS BTWN FL040-060...AREAS MVFR CIGS BTWN FL010-015 IN -SHRAS/SHRAS. BTWN 15/00Z-15/06Z...WRLY SFC WNDS AOB 12KTS...OCNL MVFR CIGS BTWN FL020-030 AND MVFR VSBYS IN -RA/RA. AFT 15/06Z...NW SFC WNDS AOB 10KT WITH VFR CIGS/VSBYS...SLGT CHC MVFR SHRAS S OF KVRB-KOBE. && .MARINE...COLD FRONT EXTENDING FROM THE FL BIG BEND TO THE YUCATAN PENINSULA WILL INTERACT WITH A DEEP AND LARGE HIGH PRES RIDGE OVER THE W ATLC TO GENERATE A MODERATE TO FRESH SW BREEZE ACRS THE LCL ATLC...BRIEFLY VEERING TO NW BEHIND PREFRONTAL CONVECTION. THE OFFSHORE WIND COMPONENT WILL LIMIT SEAS TO THE 2-4FT RANGE NEARSHORE BUT WILL GENERATE ROUGH 4-6FT WIND WAVES OFFSHORE. PREFRONTAL CONVECTIVE BAND ACRS THE N AND W PENINSULA HAS BEEN WEAKENING STEADILY AS IT HAS PUSHED INTO THE WRN FLANK OF THE ATLC RIDGE...SCT/NMRS SHRAS ASSOCD WITH THIS BAND WILL AFFECT THE CWA N OF SEBASTIAN INLET...ISOLD/SCT SHRAS TO THE S. WED NIGHT-THU NIGHT...PERSISTENT WEST TO NORTHWEST WINDS TO 20 KNOTS INCREASE SHARPLY TO 30 KNOTS OVERNIGHT WED AND EARLY THU MORNING THEN DIMINISH TO 20 KNOTS LATE THU THROUGH FRI DAYTIME MORNING. STRONG WEST TO NORTHWEST WINDS QUICKLY BUILD SEA HEIGHTS TO 9 TO 12 FEET BEYOND 20 MILES OF SHORE DAYTIME THU THEN SUBSIDE TO 4 TO 6 FEET OFFSHORE LATE THU NIGHT AS THE OFFSHORE WINDS DIMINISH TO 10 TO 15 KNOTS. PREVIOUS FRI-SUN...RESURGENCE OF NEXT FRONT LATER FRI WILL RETURN ADVERSE CONDITIONS WITH CHOPPY SEAS AND ADVISORY CONDITIONS LIKELY OVER A GOOD PORTION OF THE WATERS LATE FRI AND OR SATURDAY. && .FIRE WEATHER... WEAK DRY AIR ADVECTION WILL OCCUR BEHIND A COLD FRONT THAT WILL PUSH THROUGH CENTRAL FLORIDA OVERNIGHT. THIS DRY AIR WILL BE SUFFICIENT TO ALLOW AFTERNOON RELATIVE HUMIDITY VALUES TO DROP BELOW 35PCT ALONG AND N OF THE I-4 CORRIDOR WED AFTN...BUT WINDS BLO 15MPH AND LOW ERC VALUES IN THE L/M20S WILL PRECLUDE THE NEED FOR ANY FIRE WX STATEMENTS. THU...THE COMBINATION OF BRISK WINDS HAVING TIME TO START TO DRY OUT THE FINER AND SMALLER FUELS AND MIN RH/S IN THE MID AND UPPER 20S IN THE INTERIOR TO OSCEOLA COUNTY...STRONG TRANSPORT AND 20 FOOT WINDS AND HIGH DISPERSION VALUES WILL CREATE A FIRE SENSITIVE DAY THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... DAB 68 51 67 35 / 70 0 10 0 MCO 72 51 69 39 / 70 0 10 10 MLB 76 57 69 39 / 60 20 10 10 VRB 78 59 71 41 / 50 20 10 10 LEE 69 46 68 35 / 70 0 10 10 SFB 71 50 68 37 / 70 0 10 10 ORL 71 51 68 39 / 70 0 10 10 FPR 79 59 71 43 / 40 20 10 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$
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 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 GRAY ME
1008 PM EST TUE JAN 14 2014 .SYNOPSIS... A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL TRACK NORTHEAST ALONG THE EASTERN SEABOARD THIS WEEK. EACH OF THESE LOWS PROVIDE A ROUND OF MAINLY LIGHT PRECIPITATION...AND EACH ONE WILL ALSO BRING WAVES OF COLDER AIR. THE FIRST SYSTEM CROSSED THE REGION TODAY... BRINGING RAIN TO THE REGION. ANOTHER SYSTEM WILL BRUSH THE COAST OF NEW ENGLAND ON THURSDAY. WE WILL SEE ANOTHER ONE DAY BREAK ON FRIDAY...BEFORE ANOTHER SYSTEM MOVES IN SATURDAY. AN ALBERTA CLIPPER WILL CROSS NEW ENGLAND ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... 10 PM UPDATE: JUST SOME MINOR ADJUSTMENTS TO INCR POPS AFTER MIDNIGHT TO ADDRESS THE SLOWER EXIT OF PCPN OVER MAINE PORTIONS. NO OTHER CHANGES ATTM. 840 PM UPDATE: MADE SOME ADJUSTMENTS TO INCREASE POPS FOR THE NEXT FEW HOURS AS RADAR AND SAT PIX TRENDS SUGGESTED. TIMING OF ENDING PCPN WILL BE JUST A FEW HOURS SLOWER THAN ORIGINALLY EXPECTED. NO OTHER CHANGES ATTM. VSBYS CONTINUE TO IMPROVE AS LGT NWLY WINDS HAVE DVLPD AS LOW DEVELOPS OFF THE MIDCOAST AND IS RAPIDLY TRACKING NEWD. 640 PM UPDATE: INPUT LATEST OBS DATA. INPUT SOME LGT ACCUMS OF SNOW IN THE MTNS FOR LATER THIS EVENING...GENERALLY AN INCH OR LESS. AREAS OF FOG CONTINUE BUT MOST VSBYS 1/2-1 MI AND EXPECTED TO IMPROVE OVER THE NEXT FEW HRS. REST OF FCST LOOKS GOOD. PREV DISC; RAIN AND AREAS OF FOG WILL CONTINUE THROUGH THE EVENING HOURS. FOR A PERIOD LATER THIS EVENING...THE RAIN MAY MIX WITH SNOW IN THE MOUNTAINS. HOWEVER...THIS WILL BE A BRIEF PERIOD...AND WILL ALL OF THE RAIN TODAY...WILL NOT BE INCLUDING ANY ACCUMULATING SNOWFALL IN THE GRIDS. LATEST HRRR RUN HAS THE PRECIP ENDING AROUND 03Z IN MOST LOCATIONS. EXPECT AREAS OF FOG TO CONTINUE WITH PLENTY OF LOW LEVEL MOISTURE FROM THE RECENT RAINS. DRIER AIR WILL SLOWLY FILTER INTO THE REGION LATER TONIGHT AND WEDNESDAY MORNING. TEMPERATURES WILL FALL BELOW FREEZING BY MORNING IN JUST ABOUT ALL OF MAINE AND NEW HAMPSHIRE...SO THERE COULD BE SOME SLICK SPOTS AND BLACK ICE FOR THE MORNING COMMUTE ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... WE WILL BE IN BETWEEN WEATHER SYSTEMS WEDNESDAY AND WEDNESDAY NIGHT IN OUR FORECAST AREA. FIRST DISTURBANCE OVER THE EASTERN GREAT LAKES WILL WEAKEN AND HEAD INTO CANADA ON WEDNESDAY. THIS MAY BRING SCATTERED RAIN OR SNOW SHOWERS TO THE MOUNTAINS. A SECOND AREA OF LOW PRESSURE WILL FORM OF THE SOUTHEASTERN U.S. COASTLINE WEDNESDAY NIGHT. DURING THIS PERIOD...THE UPPER LEVEL TROUGH WILL BEGIN TO HAVE A STRONG NEGATIVE TILT AS IT REORGANIZES OFF THE SOUTH CAROLINA COASTLINE. MOST OF THE CLOUDINESS WILL REMAIN OFF THE COAST...HOWEVER THIS MAY ALLOW FOR PATCHY LATE NIGHT FOG TO FORM. && .LONG TERM /THURSDAY THROUGH TUESDAY/... WE BEGIN THE PERIOD WITH A DEEP TROUGH OVER THE EASTERN TWO-THIRDS OF THE CONUS AND A WEST COAST RIDGE. A SERIES OF IMPULSES WILL DIVE SOUTHEAST INTO THE UPPER TROUGH AND KEEP OUR WEATHER MILD BUT UNSETTLED FOR THE SECOND HALF OF THE WORKWEEK. WHILE MODELS AGREE THE UPPER TROUGH WILL EVENTUALLY SLIDE EAST AND DELIVER MUCH COLDER AIR TO THE AREA FOR THE SECOND HALF OF THE WEEKEND...THERE ARE SIGNIFICANT TIMING DIFFERENCES WITH INDIVIDUAL IMPULSES. BY MONDAY...WE`RE LEFT WITH A BROAD TROUGH OVER THE EASTERN TWO THIRDS OF THE CONUS AS THE CORE OF THE COLD AIR BEGINS TO LIFT OUT TO OUR NORTH AND EAST. HOWEVER...THE NUMERICALS SUGGEST THE UPPER TROUGH WILL ONCE AGAIN DEEPEN AND DELIVER A FRESH SHOT OF ARCTIC AIR TO THE GREAT LAKES AND NEW ENGLAND BY THE MIDDLE OF NEXT WEEK. IN THE DAILIES...LOW PRESSURE WILL DEVELOP OFF THE ATLANTIC COAST ON THURSDAY THEN PASS WELL TO OUR SOUTH AND EAST THURSDAY NIGHT FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE EARLY FRIDAY. ANOTHER LOW WILL CROSS THE REGION FRIDAY NIGHT INTO SATURDAY. ANOTHER LOW AND TRAILING COLD FRONT WILL MOVE SOUTHEAST...AND USHER MUCH COLDER AIR INTO THE REGION FOR THE SECOND HALF OF THE HOLIDAY WEEKEND. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...AREAS OF IFR WITH LOCALLY A FEW LOCATIONS WITH LIFR. CONDITIONS SLOWLY IMPROVING TONIGHT INTO EARLY WEDNESDAY. LONG TERM... THU...SCT MVFR POSSIBLE IN RAIN OR SNOW SHOWERS. FRI NIGHT - SAT...AREAS OF MVFR POSSIBLE IN RAIN OR SNOW. NW SFC WND GUSTING TO 25 KT PSBL SAT. && .MARINE... SHORT TERM...SCAS REMAIN IN EFFECT FOR THE OUTER WATERS THROUGH WEDNESDAY...MAINLY FOR SEAS...HOWEVER THERE WILL BE GUSTY WINDS EARLY THIS EVENING IN THE WATERS OFF THE MIDCOAST. LONG TERM... SAT - SUN...SMALL CRAFT CONDITIONS ARE LIKELY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EST WEDNESDAY FOR ANZ150>154. && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
845 PM EST TUE JAN 14 2014 .SYNOPSIS... A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL TRACK NORTHEAST ALONG THE EASTERN SEABOARD THIS WEEK. EACH OF THESE LOWS PROVIDE A ROUND OF MAINLY LIGHT PRECIPITATION...AND EACH ONE WILL ALSO BRING WAVES OF COLDER AIR. THE FIRST SYSTEM CROSSED THE REGION TODAY... BRINGING RAIN TO THE REGION. ANOTHER SYSTEM WILL BRUSH THE COAST OF NEW ENGLAND ON THURSDAY. WE WILL SEE ANOTHER ONE DAY BREAK ON FRIDAY...BEFORE ANOTHER SYSTEM MOVES IN SATURDAY. AN ALBERTA CLIPPER WILL CROSS NEW ENGLAND ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... 840 PM UPDATE: MADE SOME ADJUSTMENTS TO INCREASE POPS FOR THE NEXT FEW HOURS AS RADAR AND SAT PIX TRENDS SUGGESTED. TIMING OF ENDING PCPN WILL BE JUST A FEW HOURS SLOWER THAN ORIGINALLY EXPECTED. NO OTHER CHANGES ATTM. VSBYS CONTINUE TO IMPROVE AS LGT NWLY WINDS HAVE DVLPD AS LOW DEVELOPS OFF THE MIDCOAST AND IS RAPIDLY TRACKING NEWD. 640 PM UPDATE: INPUT LATEST OBS DATA. INPUT SOME LGT ACCUMS OF SNOW IN THE MTNS FOR LATER THIS EVENING...GENERALLY AN INCH OR LESS. AREAS OF FOG CONTINUE BUT MOST VSBYS 1/2-1 MI AND EXPECTED TO IMPROVE OVER THE NEXT FEW HRS. REST OF FCST LOOKS GOOD. PREV DISC; RAIN AND AREAS OF FOG WILL CONTINUE THROUGH THE EVENING HOURS. FOR A PERIOD LATER THIS EVENING...THE RAIN MAY MIX WITH SNOW IN THE MOUNTAINS. HOWEVER...THIS WILL BE A BRIEF PERIOD...AND WILL ALL OF THE RAIN TODAY...WILL NOT BE INCLUDING ANY ACCUMULATING SNOWFALL IN THE GRIDS. LATEST HRRR RUN HAS THE PRECIP ENDING AROUND 03Z IN MOST LOCATIONS. EXPECT AREAS OF FOG TO CONTINUE WITH PLENTY OF LOW LEVEL MOISTURE FROM THE RECENT RAINS. DRIER AIR WILL SLOWLY FILTER INTO THE REGION LATER TONIGHT AND WEDNESDAY MORNING. TEMPERATURES WILL FALL BELOW FREEZING BY MORNING IN JUST ABOUT ALL OF MAINE AND NEW HAMPSHIRE...SO THERE COULD BE SOME SLICK SPOTS AND BLACK ICE FOR THE MORNING COMMUTE ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... WE WILL BE IN BETWEEN WEATHER SYSTEMS WEDNESDAY AND WEDNESDAY NIGHT IN OUR FORECAST AREA. FIRST DISTURBANCE OVER THE EASTERN GREAT LAKES WILL WEAKEN AND HEAD INTO CANADA ON WEDNESDAY. THIS MAY BRING SCATTERED RAIN OR SNOW SHOWERS TO THE MOUNTAINS. A SECOND AREA OF LOW PRESSURE WILL FORM OF THE SOUTHEASTERN U.S. COASTLINE WEDNESDAY NIGHT. DURING THIS PERIOD...THE UPPER LEVEL TROUGH WILL BEGIN TO HAVE A STRONG NEGATIVE TILT AS IT REORGANIZES OFF THE SOUTH CAROLINA COASTLINE. MOST OF THE CLOUDINESS WILL REMAIN OFF THE COAST...HOWEVER THIS MAY ALLOW FOR PATCHY LATE NIGHT FOG TO FORM. && .LONG TERM /THURSDAY THROUGH TUESDAY/... WE BEGIN THE PERIOD WITH A DEEP TROUGH OVER THE EASTERN TWO-THIRDS OF THE CONUS AND A WEST COAST RIDGE. A SERIES OF IMPULSES WILL DIVE SOUTHEAST INTO THE UPPER TROUGH AND KEEP OUR WEATHER MILD BUT UNSETTLED FOR THE SECOND HALF OF THE WORKWEEK. WHILE MODELS AGREE THE UPPER TROUGH WILL EVENTUALLY SLIDE EAST AND DELIVER MUCH COLDER AIR TO THE AREA FOR THE SECOND HALF OF THE WEEKEND...THERE ARE SIGNIFICANT TIMING DIFFERENCES WITH INDIVIDUAL IMPULSES. BY MONDAY...WE`RE LEFT WITH A BROAD TROUGH OVER THE EASTERN TWO THIRDS OF THE CONUS AS THE CORE OF THE COLD AIR BEGINS TO LIFT OUT TO OUR NORTH AND EAST. HOWEVER...THE NUMERICALS SUGGEST THE UPPER TROUGH WILL ONCE AGAIN DEEPEN AND DELIVER A FRESH SHOT OF ARCTIC AIR TO THE GREAT LAKES AND NEW ENGLAND BY THE MIDDLE OF NEXT WEEK. IN THE DAILIES...LOW PRESSURE WILL DEVELOP OFF THE ATLANTIC COAST ON THURSDAY THEN PASS WELL TO OUR SOUTH AND EAST THURSDAY NIGHT FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE EARLY FRIDAY. ANOTHER LOW WILL CROSS THE REGION FRIDAY NIGHT INTO SATURDAY. ANOTHER LOW AND TRAILING COLD FRONT WILL MOVE SOUTHEAST...AND USHER MUCH COLDER AIR INTO THE REGION FOR THE SECOND HALF OF THE HOLIDAY WEEKEND. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...AREAS OF IFR WITH LOCALLY A FEW LOCATIONS WITH LIFR. CONDITIONS SLOWLY IMPROVING TONIGHT INTO EARLY WEDNESDAY. LONG TERM... THU...SCT MVFR POSSIBLE IN RAIN OR SNOW SHOWERS. FRI NIGHT - SAT...AREAS OF MVFR POSSIBLE IN RAIN OR SNOW. NW SFC WND GUSTING TO 25 KT PSBL SAT. && .MARINE... SHORT TERM...SCAS REMAIN IN EFFECT FOR THE OUTER WATERS THROUGH WEDNESDAY...MAINLY FOR SEAS...HOWEVER THERE WILL BE GUSTY WINDS EARLY THIS EVENING IN THE WATERS OFF THE MIDCOAST. LONG TERM... SAT - SUN...SMALL CRAFT CONDITIONS ARE LIKELY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EST WEDNESDAY FOR ANZ150>154. && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
707 PM EST TUE JAN 14 2014 .SYNOPSIS... A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL TRACK NORTHEAST ALONG THE EASTERN SEABOARD THIS WEEK. EACH OF THESE LOWS PROVIDE A ROUND OF MAINLY LIGHT PRECIPITATION...AND EACH ONE WILL ALSO BRING WAVES OF COLDER AIR. THE FIRST SYSTEM CROSSED THE REGION TODAY... BRINGING RAIN TO THE REGION. ANOTHER SYSTEM WILL BRUSH THE COAST OF NEW ENGLAND ON THURSDAY. WE WILL SEE ANOTHER ONE DAY BREAK ON FRIDAY...BEFORE ANOTHER SYSTEM MOVES IN SATURDAY. AN ALBERTA CLIPPER WILL CROSS NEW ENGLAND ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... 640 PM UPDATE: INPUT LATEST OBS DATA. INPUT SOME LGT ACCUMS OF SNOW IN THE MTNS FOR LATER THIS EVENING...GENERALLY AN INCH OR LESS. AREAS OF FOG CONTINUE BUT MOST VSBYS 1/2-1 MI AND EXPECTED TO IMPROVE OVER THE NEXT FEW HRS. REST OF FCST LOOKS GOOD. PREV DISC; RAIN AND AREAS OF FOG WILL CONTINUE THROUGH THE EVENING HOURS. FOR A PERIOD LATER THIS EVENING...THE RAIN MAY MIX WITH SNOW IN THE MOUNTAINS. HOWEVER...THIS WILL BE A BRIEF PERIOD...AND WILL ALL OF THE RAIN TODAY...WILL NOT BE INCLUDING ANY ACCUMULATING SNOWFALL IN THE GRIDS. LATEST HRRR RUN HAS THE PRECIP ENDING AROUND 03Z IN MOST LOCATIONS. EXPECT AREAS OF FOG TO CONTINUE WITH PLENTY OF LOW LEVEL MOISTURE FROM THE RECENT RAINS. DRIER AIR WILL SLOWLY FILTER INTO THE REGION LATER TONIGHT AND WEDNESDAY MORNING. TEMPERATURES WILL FALL BELOW FREEZING BY MORNING IN JUST ABOUT ALL OF MAINE AND NEW HAMPSHIRE...SO THERE COULD BE SOME SLICK SPOTS AND BLACK ICE FOR THE MORNING COMMUTE ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... WE WILL BE IN BETWEEN WEATHER SYSTEMS WEDNESDAY AND WEDNESDAY NIGHT IN OUR FORECAST AREA. FIRST DISTURBANCE OVER THE EASTERN GREAT LAKES WILL WEAKEN AND HEAD INTO CANADA ON WEDNESDAY. THIS MAY BRING SCATTERED RAIN OR SNOW SHOWERS TO THE MOUNTAINS. A SECOND AREA OF LOW PRESSURE WILL FORM OF THE SOUTHEASTERN U.S. COASTLINE WEDNESDAY NIGHT. DURING THIS PERIOD...THE UPPER LEVEL TROUGH WILL BEGIN TO HAVE A STRONG NEGATIVE TILT AS IT REORGANIZES OFF THE SOUTH CAROLINA COASTLINE. MOST OF THE CLOUDINESS WILL REMAIN OFF THE COAST...HOWEVER THIS MAY ALLOW FOR PATCHY LATE NIGHT FOG TO FORM. && .LONG TERM /THURSDAY THROUGH TUESDAY/... WE BEGIN THE PERIOD WITH A DEEP TROUGH OVER THE EASTERN TWO-THIRDS OF THE CONUS AND A WEST COAST RIDGE. A SERIES OF IMPULSES WILL DIVE SOUTHEAST INTO THE UPPER TROUGH AND KEEP OUR WEATHER MILD BUT UNSETTLED FOR THE SECOND HALF OF THE WORKWEEK. WHILE MODELS AGREE THE UPPER TROUGH WILL EVENTUALLY SLIDE EAST AND DELIVER MUCH COLDER AIR TO THE AREA FOR THE SECOND HALF OF THE WEEKEND...THERE ARE SIGNIFICANT TIMING DIFFERENCES WITH INDIVIDUAL IMPULSES. BY MONDAY...WE`RE LEFT WITH A BROAD TROUGH OVER THE EASTERN TWO THIRDS OF THE CONUS AS THE CORE OF THE COLD AIR BEGINS TO LIFT OUT TO OUR NORTH AND EAST. HOWEVER...THE NUMERICALS SUGGEST THE UPPER TROUGH WILL ONCE AGAIN DEEPEN AND DELIVER A FRESH SHOT OF ARCTIC AIR TO THE GREAT LAKES AND NEW ENGLAND BY THE MIDDLE OF NEXT WEEK. IN THE DAILIES...LOW PRESSURE WILL DEVELOP OFF THE ATLANTIC COAST ON THURSDAY THEN PASS WELL TO OUR SOUTH AND EAST THURSDAY NIGHT FOLLOWED BY A WEAK RIDGE OF HIGH PRESSURE EARLY FRIDAY. ANOTHER LOW WILL CROSS THE REGION FRIDAY NIGHT INTO SATURDAY. ANOTHER LOW AND TRAILING COLD FRONT WILL MOVE SOUTHEAST...AND USHER MUCH COLDER AIR INTO THE REGION FOR THE SECOND HALF OF THE HOLIDAY WEEKEND. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM...AREAS OF IFR WITH LOCALLY A FEW LOCATIONS WITH LIFR. CONDITIONS SLOWLY IMPROVING TONIGHT INTO EARLY WEDNESDAY. LONG TERM... THU...SCT MVFR POSSIBLE IN RAIN OR SNOW SHOWERS. FRI NIGHT - SAT...AREAS OF MVFR POSSIBLE IN RAIN OR SNOW. NW SFC WND GUSTING TO 25 KT PSBL SAT. && .MARINE... SHORT TERM...SCAS REMAIN IN EFFECT FOR THE OUTER WATERS THROUGH WEDNESDAY...MAINLY FOR SEAS...HOWEVER THERE WILL BE GUSTY WINDS EARLY THIS EVENING IN THE WATERS OFF THE MIDCOAST. LONG TERM... SAT - SUN...SMALL CRAFT CONDITIONS ARE LIKELY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EST WEDNESDAY FOR ANZ150>154. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
627 PM EST TUE JAN 14 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 359 PM EST TUE JAN 14 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH FROM HUDSON BAY INTO THE CNTRL CONUS. A POTENT SHORTWAVE TROUGH LOCATED OVER SRN WI WAS MOVING TOWARD SRN LOWER MI. AT THE SFC CIRCULATION AROUND A 999 MB LOW PRES OVER E CNTRL WI RESULTED IN STRONG NE WINDS INTO SRN UPPER MI. INCREASING NRLY WINDS ACROSS LAKE SUPERIOR ALONG WITH 850 MB TEMPS IN THE -13C TO -16C RANGE SUPPORTED LIGHT LES FOR LOCATIONS FAVORED BY NNE WINDS. STRONG 700-500 MB QVECTOR CONV AND FGEN (FN/FS CONV) NEAR THE SHRTWV PIVOT POINT HAS PRODUCED HEAVY SNOWFALL RATES OF AN INCH OR TWO PER HOUR OVER FAR SRN UPPER (MNM) MI WHERE 7 INCHES HAD FALLEN BY 20Z. THIS ALSO ALIGNED WELL WITH THE SRN EXTENT OF THE COLDER CLOUD TOPS...PER IR LOOP. LATE THIS AFTERNOON AND TONIGHT...SATELLITE/RADAR TRENDS AND SHORT RANGE MODELS SUGGEST THAT THE COMMA HEAD PORTION OF THE SHRTWV WILL MOVE INTO LAKE MI THIS EVENING BTWN 00Z-03Z AND DRAG THE BACK END OF THE SNOW OUT OF THE SRN CWA. UNTIL THEN...MODERATE TO HEAVY SNOW WILL CONTINUE OVER THE SOUTH ALONG WITH NE WINDS GUSTING TO AROUND 30 MPH. EXPECT THE LES IN CONVERGENT NRLY FLOW INTO WRN ALGER COUNTY TO INCREASE AS THE DEEPER MOISTURE WITH THE SYNOPTIC SYSTEM EDGES SLOWLY NORTHWARD. ALTHOUGH THE DEEPER MOISTURE WILL DEPART AFT 06Z...INSTABILITY WILL INCREASE AS CAA DROPS 850 MB TEMPS TO AROUND -17C. MODERATE SNOWFALL AMOUNTS IN THE 3 TO 5 INCH RANGE ARE EXPECTED MAINLY NEAR AU TRAIN/EBEN/CHATHAM...PER CONSENSUS OF HIGHER RES MODELS. OVER THE WEST...INVERSION HEIGHTS AROUND 3K FT SHOULD LIMIT SNOW AMOUNTS TO LESS THAN AN INCH. WED....MID/UPPER LEVEL RIDGING WILL DEVELOP OVER THE NRN LAKES AHEAD OF THE NEXT SHRTWV DIVING TOWARD SRN MANITOBA AND NRN MN. AT THE SURFACE...A RIDGE FROM MN INTO NW ONTARIO WILL BUILD TOWARD THE SRN GREAT LAKES AS A DEEP CLIPPER LOW MOVES TO NEAR LAKE WINNIPEG. THIS WILL LEAD TO NORTH-NORTHWEST WINDS ACROSS LAKE SUPERIOR AND WITH 850MB TEMPS AROUND -16C THERE WILL BE ENOUGH LAKE INSTABILITY AND LOW LEVEL MOISTURE FOR LINGERING LAKE EFFECT. BUT WITH THE SURFACE RIDGE QUICKLY SLIDING THROUGH THE UPPER GREAT LAKES...EXPECT WINDS TO QUICKLY BACK THROUGH THE DAY. THE BACKING WINDS...ALONG WITH DRIER LOW LEVEL AIR WILL BRING AN END TO THE LAKE EFFECT OVER THE WEST AROUND EARLY AFTERNOON AND THEN OVER THE EAST BY LATE AFTERNOON. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 446 PM EST TUE JAN 14 2014 RIDGE WEST...TROUGH EAST. THE PATTERN REMAINS THROUGH THROUGH MUCH OF THE LONG TERM PERIOD. FOR AN OVERVIEW OF WHAT WILL BE HAPPENING ALOFT...THE 500MB LOW OVER N MANITOBA AT 00Z THURSDAY WILL SWEEP INTO CENTRAL ONTARIO AND THE W HALF OF LAKE SUPERIOR BY 12Z THURSDAY. AT THAT POINT THE LOW WILL SLOW DOWN QUITE A BIT...AND REMAIN ACROSS THE UPPER GREAT LAKES THROUGH THE DAY THURSDAY...BEFORE THE LINGERING TROUGH SLOWLY EXITS ACROSS EASTERN ONTARIO AND LAKE HURON FRIDAY AND FRIDAY NIGHT. THIS WILL KEEP NNW FLOW ALOFT ACROSS LAKE SUPERIOR AND UPPER MI FROM FRIDAY AFTERNOON THROUGH SUNDAY MONDAY. AS FOR SPECIFICS...THE SFC LOW NEAR THE S MANITOBA/ONTARIO BORDER JUST PRIOR TO 06Z THURSDAY SHOULD SHIFT SE INTO S CENTRAL LAKE SUPERIOR/AND THE W HALF OF UPPER MI BY 18Z. S-SSW WINDS WILL REMAIN IN THE 10-20KT RANGE WEDNESDAY NIGHT. WARMER AIR WILL BE ABLE TO SWEEP IN FOR THURSDAY...WITH HIGHS IN THE UPPER 20S...THANKS TO THE MID AFTERNOON LOW PASSAGE ALLOWING 850MB TEMPS TO RISE INTO THE -5 TO -7F RANGE. EXPECT THE SFC LOW TO EXIT FAR E UPPER MI THURSDAY NIGHT INTO FRIDAY. GIVEN THE SLOW PROGRESS OF THE LOW...LOOK FOR A SIGNIFICANT BREAK BETWEEN THE STRONG W-SSW WINDS WEDNESDAY NIGHT AND COLDER AIR RUSHING IN THE N-NNW WINDS THURSDAY NIGHT INTO FRIDAY. HIGH FRIDAY SHOULD BE ON THE ORDER OF 15F COOLER OVER W AND CENTRAL UPPER MI...WHILE ONLY A COULD DEGREES COOLER E. ALTHOUGH FAR W LAKE SUPERIOR MAY BE PRETTY FROZEN...THERE IS LIKELY PLENTY OF RELATIVELY WARM OPEN WATER STILL AVAILABLE N OF THE APOSTLE ISLANDS TO ALLOW THE MAINLY N FLOW OF COLD AIR TO PRODUCE MODERATE LES FROM LATE THURSDAY AFTERNOON THROUGH THE DAY FRIDAY. THE FLOW BECOMES MORE W-NW OVER W LAKE SUPERIOR FRIDAY EVENING AS WAA TAKES HOLD AND 850MB TEMPS THAT WERE ON THE ORDER OF -14 TO -17C QUICKLY JUMP UP TO AROUND -10C. LES WILL CONTINUE TO PERSIST NEAR AND E OF MUNISING INTO SATURDAY. THERE IS STILL A QUESTION AS TO HOW LONG THE FETCH REMAINS FAVORABLE FOR THIS AREA...AS THE 12Z ECMWF IS GOING WITH A MORE W FLOW NEAR THE SFC...WHICH WOULD KEEP THE BEST CHANCE OF LES ONLY RIGHT ALONG THE SHORELINE E SATURDAY...IF NOT OFF SHORE. A SIZABLE RIDGE EXTENDING UP FROM THE 4-CORNERS REGION THROUGH THE DAKOTAS AND SOUTH CENTRAL CANADA SUNDAY MORNING WILL BRIEFLY MOVE ACROSS THE UPPER GREAT LAKES SUNDAY AFTERNOON INTO SUNDAY EVENING. WHILE THE 12Z RUN OF THE GFS IS LESS THAN IMPRESSIVE WITH THE RIDGE...THE 00Z RUNS OF THE ECMWF AND TO A GREATER EXTENT THE CANADIAN MODEL. OTHERWISE PAST SUNDAY EVENING WE GET BACK INTO THE PERSISTENT NW FLOW AGAIN ALOFT...THANKS TO THE MAIN 500MB LOW SLIDING FROM N CENTRAL CANADA FRIDAY NIGHT...ACROSS JAMES BAY SATURDAY NIGHT...AND INTO QUEBEC SUNDAY/SUNDAY NIGHT. WHILE THE MAIN LOW RETREATS BACK N...A MODERATED PIECE OF THE COLDER AIR WILL BE ABLE TO DIVE IN MONDAY NIGHT THROUGH MUCH OF THE UPCOMING WORK WEEK /AT LEAST ACCORDING TO THE 12Z ECMWF/. GIVEN THE PERSISTENT N-NNW FLOW...HAVE INCREASED POPS FOR MONDAY NIGHT THROUGH TUESDAY ALONG LAKE SUPERIOR TO LIKELY AND DEFINITE CATEGORIES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 627 PM EST TUE JAN 14 2014 LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH WED MORNING. EXPECT MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. AS WINDS BACK TO THE SW...LAKE EFFECT WILL END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 359 PM EST TUE JAN 14 2014 NORTH WINDS OF 30 KNOTS OVER ERN LAKE SUPERIOR TONIGHT AS A SFC LOW PASSES SOUTH AND EAST OF REGION WILL PRODUCE HEAVY FREEZING SPRAY. EXPECT THE WINDS TO DIMINISH BRIEFLY ON WEDNESDAY AS A HIGH PRESSURE RIDGE CROSSES THE REGION. LOW PRESSURE CROSSING LAKE WINNIPEG LATE WEDNESDAY AFTERNOON WILL THEN SINK ACROSS LAKE SUPERIOR ON THURSDAY. SW GALES OF 35 KTS ARE POSSIBLE WEDNESDAY NIGHT OVER EASTERN SECTIONS. N-NW GALES OF 35 KTS ARE ALSO POSSIBLE LATE THURSDAY AFTERNOON THROUGH FRIDAY MORNING IN WAKE OF A COLD FRONT FOLLOWING THE LOW. THE LOW WILL WEAKEN AS IT DRIFTS EASTWARD INTO SOUTHERN ONTARIO THROUGH THE DAY FRIDAY...WHILE KEEPING A WEAK TROUGH OVER LAKE SUPERIOR. HEAVY FREEZING SPRAY WILL BE POSSIBLE THURSDAY NIGHT THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR MIZ011. WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR MIZ013. WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR MIZ012. LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ006. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST WEDNESDAY FOR LSZ248>251-265>267. HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ244- 245-263-264. LAKE MICHIGAN... GALE WARNING UNTIL 9 AM EST WEDNESDAY FOR LMZ250. && $$ SHORT TERM...JLB LONG TERM...KF AVIATION...07 MARINE...JLB
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 RALEIGH NC
901 PM EST TUE JAN 14 2014 .SYNOPSIS...HIGH PRESSURE WILL BRIEFLY BUILD INTO THE REGION OVERNIGHT. A COLD FRONT WILL MOVE THROUGH THE AREA LATE WEDNESDAY/WEDNESDAY NIGHT. WEAK HIGH PRESSURE BRIEFLY BUILDS INTO THE REGION ONCE AGAIN ON THURSDAY...WITH A STRONGER COLD FRONT PASSAGE THROUGH THE AREA LATE FRIDAY. && .NEAR TERM /TONIGHT AND WEDNESDAY/... AS OF 900 PM TUESDAY... TONIGHT: MAIN FORECAST CHALLENGE FOR TONIGHT IS THE EXTENT/DURATION OF FOG. CLEAR SKIES AND WEAK SFC RIDGING EXTENDING INTO THE AREA FROM THE SW HAS PROMOTED CALM SFC WINDS. SOME PATCHY DENSE FOG... HAS ALREADY DEVELOPED ACROSS COASTAL COUNTIES WHERE LOW-LEVELS REMAIN QUIET MOIST...PER 00Z/15 MHX RAOB...WITH ONLY MINOR/WEAK ADVECTION OF DRY AIR FROM THE WEST COMPARED TO WESTERN PORTIONS OF THE STATE(PER LATEST GSO RAOB). MUCH OF THE MODEL GUIDANCE INDICATES DEWPOINTS WILL FALL OVERNIGHT...WHICH WOULD INHIBIT FOG...PARTICULARLY DENSE FOG. HOWEVER THE LATEST RAP GUIDANCE KEEPS DEWPOINTS PRETTY MUCH STATUS QUO OVERNIGHT WITH NO DRIER AIR WORKING IN FROM THE WEST WHICH IS VERY PLAUSIBLE GIVEN WEAK SFC WINDS. WILL CONTINUE TO MONITOR THESE TRENDS...AND IF THE DRIER DOES NOT DOES NOT BUILD EAST...A DENSE FOG ADVISORY MAY NEED TO BE ISSUED FOR CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA. LOWS RANGING FROM LOWER TO MID 30 NW TO UPPER 30S TO AROUND 40 SE. FOR THE DAY WEDNESDAY...THE SURFACE FRONT GRADUALLY MOVES EAST INTO CENTRAL NORTH CAROLINA...THEN SLOWS AS THE UPPER TROUGH SHARPENS... AND THE SOUTHWEST JET AT 300MB INCREASES TO 135KT LATE IN THE DAY OVER CENTRAL NORTH CAROLINA HELPING TO PROVIDE FOR SLOWLY DEEPENING LOW PRESSURE OFF THE COAST. THE RIGHT ENTRANCE REGION OF A 90KT 500MB JET MOVES NEAR OR INTO THE NORTHWEST PIEDMONT LATE IN THE DAY. MOISTURE IS NOT GREAT...WITH K INDICES ONLY ON THE GFS BARELY BEYOND SINGLE FIGURES AND WITH AN 850MB THETA-E RIDGE THAT IS CERTAINLY WEAK COMPARED TO RECENT PRECIPITATION EVENTS. HOWEVER...LIFT DOES INCREASE LATE WITH THE APPROACH OF THE MID-LEVEL JET. QPF FROM THE NAM...GFS...AND ECMWF IS LIMITED WITH ONLY LIGHT...NEAR HUNDREDTH VALUES...MOSTLY WEST OF U.S. 1 VERY LATE IN THE DAY IF THERE IS ANY AT ALL. NAM AND GFS BUFR SOUNDINGS SUGGEST ENOUGH OF A COMBINATION OF MID- AND LOW-LEVEL MOISTURE THAT SOME LIGHT PRECIPITATION COULD BEGIN REACHING THE GROUND AFTER 21Z IN THOSE AREAS...BETTER CHANCE IN A RELATIVE SENSE TOWARD THE IMMEDIATE TRIAD. AS THE GRADIENT TIGHTENS LATE IN THE DAY OVER THE WESTERN PART OF THE STATE...AN INCREASING NORTHERLY SURFACE FLOW...COUPLED WITH ANY SPOTTY PRECIPITATION...COULD RESULT IN RAPIDLY COOLING TEMPERATURES LATE IN THE DAY IN THE TRIAD. BEFORE THEN...1000-850MB THICKNESSES SUPPORT HIGHS CLOSE TO THE MOS GUIDANCE CONSENSUS...IN THE LOWER 50S NORTHWEST TO AROUND 60 SOUTHEAST UNDER A PARTLY SUNNY SKY ON AVERAGE FOR THE ENTIRE DAY. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 250 PM TUESDAY... MULTIPLE SHORTWAVE TROUGHS WILL DIVE INTO THE SOUTHEASTERN U.S. DURING THE SHORT-TERM PERIOD CULMINATING IN A STRONG NEGATIVELY TILTED TROUGH THAT WIL SWING THROUGH THE CAROLINAS ON THURSDAY MORNING. MEANWHILE AN ARCTIC COLD FRONT WILL MOVE EAST ACROSS CENTRAL NC DURING THE LATE AFTERNOON WEDNESDAY AND WEDNESDAY NIGHT. AS THE IMPRESSIVE MID LEVEL WAVE WITH STRONG HEIGHT FALLS AND A 100+KT JET AT 500 HPA APPROACHES THE ARCTIC COLD FRONT AND THE STALLED FRONT NEAR THE GULF STREAM...CYCLOGENESIS WILL COMMENCE LATE WEDNESDAY NIGHT OFFSHORE OF CAPE FEAR. FORECAST CONFIDENCE REMAINS BELOW AVERAGE FOR THIS PERIOD AS GUIDANCE HAS BEEN EVOLVING IN THE HANDLING OF THE ARCTIC COLD FRONT AND THE RESULTANT CYCLOGENESIS. IT SHOULD BE NOTED THAT GUIDANCE IS TRENDING SLOWER WITH A MORE AMPLIFIED UPPER AIR PATTERN AND A STRONGER SURFACE SYSTEM ALBEIT WITH VARYING QPF SCENARIOS. THE MOST LIKELY SCENARIO AT THIS POINT IS FOR AN AREA OF MAINLY LIGHT PRECIPITATION TO SPREAD EAST OUT OF THE NC FOOTHILLS LATE WEDNESDAY AFTERNOON AND MOVE INTO THE WESTERN PIEDMONT TOWARD SUNSET. WHILE THE PRECIPITATION WILL FALL BEHIND THE ARCTIC FRONT...THE NEAR SURFACE TEMPERATURES WIL BE SUFFICIENTLY WARM AND DEEP TO RESULT IN A RAIN PTYPE THROUGH AT LEAST INTO EARLY EVENING. THE SURGE OF COLD AIR EASTWARD DURING THE LATE EVENING AND OVERNIGHT SHOULD DRIVE A CHANGEOVER TO SNOW FROM WEST TO EAST OVERNIGHT. PRECIPITATION AMOUNTS ARE EXPECTED TO BE LIGHT AND LESS THAN IF NOT MUCH LESS THAN A TENTH OF AN INCH....MAINLY WEST OF U.S. ROUTE 1 WITH LITTLE IF ANY PRECIPITATION EAST ACROSS THE COASTAL PLAIN. THIS COULD RESULT IN A LIGHT COATING OF SNOW BY THURSDAY MORNING IN THE NORTHERN AND NORTHWEST PIEDMONT BUT THIS IS LIKELY A MORE EXTREME SCENARIO WITH MOST LOCATIONS ONLY OBSERVING A PERIOD OF LIGHT LIGHT SNOW FOR A FEW HOURS WITH NO ACCUMULATION. TEMPERATURES BY THURSDAY MORNING WILL FALL TO OR BELOW FREEZING ACROSS ALL OF THE RAH CWA WITH MINIMUMS RANGING FROM 25 IN THE NORTHWEST PIEDMONT TO AROUND 30 IN THE COASTAL PLAIN. GUIDANCE CONTINUES TO TREND SLOWER WITH LIGHT PRECIPITATION NOW PERSISTING INTO THURSDAY MORNING AS IT GRADUALLY SHIFTS EAST. QPF AMOUNTS AGAIN ARE EXPECTED TO BE LIGHT AND LESS THAN A TENTH OF AN INCH. INITIALLY THE PREDOMINANT P-TYPE WILL LIKELY BE SNOW THURSDAY MORNING WITH SURFACE TEMPERATURES CONFINED TO THE 30S DURING THE MORNING BUT NAM/GFS BUFR SOUNDINGS SUGGEST THAT THE MOISTURE MAY NOT BE SUFFICIENTLY DEEP TO EXTEND IN THE ICE NUCLEATION REGION AND ABOVE FREEZIN TEMPS WILL PROBABLY RESULT IN MORE OF A RIAN.SBNOW MIX. REGARDLESS THE LIGHT NATURE OF THE PRECIPITATION SHOULD PRECLUDE ANY APPRECIABLE ACCUMULATION DURING THE DAY THURSDAY. WE WILL NEED TO MONITOR THE INTENSITY AND TRACK OF THE DEVELOPING SURFACE LOW AS ONLY A SMALL WESTWARD SHIFT WOULD POTENTIALLY RESULT IN NOTICEABLY MORE PRECIPITATION IN LOCATIONS EAST OF U.S. 1 ON THURSDAY. ALL OF THE PRECIPITATION SHOULD END BY EARLY AFTERNOON WITH HIGHS EVENTUALLY REACHING THE 40-45 RANGE BY LATE IN THE DAY. DRY WEATHER WITH CLEARING SKIES ARE EXPECTED ON THURSDAY NIGHT. LOWS SHOULD FALL INTO THE 26-32 RANGE BY FRIDAY MORNING. -BLAES && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3315 PM TUESDAY... THE LONG TERM PERIOD FEATURES A PROGRESSIVE PATTERN WITH SYSTEMS DROPPING INTO THE MID ATLANTIC AND SOUTHEAST ON THE NORTHWEST ALOFT BRINGING QUICK THREATS OF PRECIPITATION AND BRIEF SHOTS OF COLDER AIR. THE SOUTHERN STREAM BECOMES MORE ACTIVE LATE IN THE PERIOD SUGGESTING A MILDER PRECIPITATION EVENT POSSIBLE LATE TUESDAY. THE NEXT STORM SYSTEM ASSOCIATED WITH ANOTHER STRONG NORTHERN STREAM WAVE WILL MOVE THROUGH THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. IT APPEARS THE AIRMASS WILL BE SUFFICIENTLY COLD TO MAINTAIN A MENTION OF RAIN MIXING WITH OR CHANGING TO SNOW AS COLD ARCTIC AIR PUSHES INTO THE REGION BEHIND THE FTRONT.CONFIDENCE IN THE DETAILS ASSOCIATED WITH THIS SYSTEM ARE RATHER LOW AS GUIDANCE IS QUITE VARIED BUT AT THIS POINT IT IS LIKELY TO REMAIN A VERY LIGHT QPF EVENT. FAIR WEATHER IS EXPECTED LATER SATURDAY BEFORE THE NEXT SYSTEM IN THE STRONG NORTHWEST FLOW ARRIVES SATURDAY NIGHT. THIS SYSTEM APPEARS EVEN MORE MOISTURE DEPRIVED WITH A TRACK FURTHER NORTH...AND WILL ACCORDINGLY KEEP THE FORECAST DRY. HIGHS IN THE UPPER 30S TO LOWER 40S SATURDAY WILL WARM INTO THE LOWER TO MID 40S SUNDAY AND THE LOWER 50S BY MONDAY. INCREASING CLOUDS ARE EXPECTED ON MONDAY AS THE SOUTHERN STREAM BECOMES MORE ACTIVE AND A BROAD EASTERN U.S. TROUGH SHARPENS SOMEWHATS. TEMPERATURES WILL HAVE MODIFIED SUFFICIENTLY FOR A RAIN P- TYPE AS HIGHS TUESDAY SHOULD RANGE IN THE LOWER TO MID 50S. -BLAES && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 750 PM TUESDAY... SURFACE LOW PRESSURE HAS LIFTED OFF TO THE NORTHEAST OF THE AREA THIS EVENING... WITH A REMAINING LINGERING DAMP MOIST LOW LEVEL/SURFACE AIRMASS. THIS COUPLED WITH CALM/LIGHT AND VARIABLE WINDS OVERNIGHT ALONG WITH CLEAR SKIES WILL LEAD TO THE POTENTIAL FOR SUB-VFR VISBYS. LOCATIONS ACROSS THE EASTERN HALF OF CENTRAL NC ARE ALREADY BEGINNING TO SEE FOG DEVELOPMENT THIS EVENING... WHICH MAKES SENSE AS THIS IS WHERE THE RAIN FALL ENDED LAST AND HAS THUS SEEN THE LEAST AMOUNT OF DRYING BEFORE NIGHTFALL. FOR NOW WILL SHOW IFR/LIFR CONDITIONS AT KRDU/KRWI/KFAY THIS EVENING INTO THE OVERNIGHT HOURS... WITH POSSIBLY SLOWLY IMPROVING CONDITIONS AFTER SUNRISE (FOR NOW WILL SHOW VFR CONDITIONS BY 15Z OR SO). FURTHER WEST WHERE THE LOW LEVEL AIRMASS HAD THE MOST TIME TO DRY OUT... WILL SHOW LOW END MVFR... BUT CANT COMPLETELY RULE OUT IFR OR EVEN LIFR VISBYS. AFTER THE FOG/LOW STRATUS LIFTS/DISSIPATES WEDNESDAY MORNING EXPECT VFR CONDITIONS WITH INCREASING MID AND HIGH LEVEL CLOUD COVER AS ANOTHER COLD FRONT APPROACHES THE AREA FROM THE WEST. HOWEVER... WINDS WILL REMAIN LIGHT THROUGH THE AFTERNOON THOUGH... GENERALLY ANY PRECIP WILL HOLD JUST TO THE WEST OF THE AREA THROUGH THE 00Z TAF PERIOD. BEYOND THE 00Z VALID TAF PERIOD...A COLD FRONT WILL MOVE ACROSS CENTRAL NC WEDNESDAY EVENING... THEN PUSH OFF THE COAST AS HIGH PRESSURE BUILDS IN BRIEFLY THURSDAY. WE MAY SEE SOME LIGHT SHOWERS AND POSSIBLY EVEN A FEW SNOW FLAKES WEDNESDAY EVENING/NIGHT ASSOCIATED WITH THE FRONT... ALONG WITH SOME SUB-VFR CONDITIONS WEDNESDAY EVENING THROUGH POSSIBLY MID MORNING THURSDAY. ANOTHER COUPLE OF COLD FRONT ARE EXPECTED TO CROSS THE REGION LATE WEEK INTO THE WEEKEND... WITH THE FIRST FRONT ON FRIDAY/FRIDAY NIGHT POSSIBLY BRING WITH IT ANOTHER ROUND OF PRECIP AND POSSIBLE SUB-VFR CONDITIONS. OTHERWISE DRY AND VFR CONDITIONS ARE EXPECTED. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL/DJF NEAR TERM...CBL/DJF SHORT TERM...BLAES LONG TERM...BLAES AVIATION...BSD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
756 PM EST TUE JAN 14 2014 .SYNOPSIS... A COLD FRONT WILL MOVE OFF THE COAST THIS EVENING FOLLOWED BY ANOTHER COLD FRONT WEDNESDAY NIGHT. A STRONGER COLD FRONT WILL CROSS THE AREA LATE FRIDAY FOLLOWED BY A REINFORCING SHOT OF COLD AIR ON SUNDAY. DRY HIGH PRESSURE WILL BUILD INTO THE AREA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 715 PM TUESDAY...PCPN HAS ENDED ACROSS THE FA...WITH THE COLD FRONT HAVING PUSHED ACROSS THE ILM CWA AND OFF THE COAST JUST WITHIN A FEW HRS AGO. LATEST SAT IMAGERY...THE 11.0-3.9 IR CHANNEL...ILLUSTRATES CLEAR SKIES HAVE OVER-TAKEN THE ILM CWA AS DRIER AIR IN THE MID-UPPER LEVELS HAS PUSHED ACROSS. HOWEVER...LATEST HOURLY NAMBUFR SOUNDINGS ACROSS THE ILM CWA INDICATE TRAPPED MOISTURE IN THE VERY LOWER LEVELS...BASICALLY BELOW 980MB...FOR THE OVERNITE AND PRE-DAWN WED HRS. WINDS BASICALLY CALM TO LESS THAN 5 KT FROM THE SFC UP TO 980MB. AS A RESULT OF THIS SHALLOW DEPTH OF MOISTURE...HAVE LEANED TOWARD FOG BECOMING AN ISSUE RATHER THAN LOW STRATUS. HAVE BEEFED UP THE COVERAGE FROM PATCHY TO AREAS OF FOG. MAY NEED TO FURTHER INCREASE THE FOG COVERAGE TO WIDESPREAD WITH POSSIBLE DENSE AT THE NEXT UPDATE. WITH LESS ANTICIPATED LOW LEVEL STRATUS COVERAGE...HAVE GONE WITH CLEAR TO MOSTLY CLEAR FOR OVERNIGHT SKY CONDITIONS. CURRENT MIN FORECAST LOOKS AOK WITH VERY LITTLE IF ANY TWEAKING NEEDED BASED ON VARIOUS 18Z MODEL MOS GUIDANCE. PREVIOUS DISCUSSION................................................... AS OF 300 PM TUESDAY...THE COLD FRONT CONTINUES TO PRESS EASTWARD AS IT IS APPROACHES RALEIGH BUT IS IT STILL LAGS A BIT TO THE SOUTH. A POSSIBLE PRE-FRONTAL TROUGH IS RUNNING AHEAD OF THE FRONT TO THE SOUTH. THE 18Z UTC RUC IS SHOWING THE 850 LOW LEVEL JET MAX CENTERED OVER SOUTH CAROLINA AND THIS FEATURE WILL SHIFT NORTH OUT OF THE AREA BY 22 UTC. THIS APPEARS TO BE THE WHAT IS ENHANCING THE LOW TOP CONVECTION IN INLAND AREAS OF SOUTHEAST NORTH CAROLINA. SEA FOG IS NOW BREAKING UP ALONG THE GEORGETOWN COAST AND WILL LINGER FOR THE NEXT HALF HOUR BEFORE BECOMING A NONE FACTOR. MODELS STILL CONTINUE TO BRING A FRONT TO THE COAST BY 7 PM BUT THE MODELS MAINTAIN A GOOD CHANCE OF SHOWERS EARLY THEN SLOWLY TAPER THE RAIN OFF OVERNIGHT. QPF VALUES APPEAR TO BE LESS THAN A HALF OF AN INCH. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...WILL A LITTLE SNOW FALL EARLY THURS OR NOT IS THE QUESTION... A WAVE OF LOW PRESSURE WILL MOVE UP ALONG COLD FRONT WELL OFF SHORE IN DEEP SW FLOW AHEAD OF DEEPENING TROUGH DIGGING DOWN FROM THE GREAT LAKES TOWARD THE GULF COAST ON WED. EXPECT SUNNY AND DRY WEATHER AHEAD OF THIS SYSTEM WITH TEMPS UP CLOSER TO 60 BUT THIS TROUGH WILL ADVANCE EASTWARD THROUGH WEDNESDAY PUSHING ANOTHER COLD FRONT INTO AND THROUGH THE CAROLINAS WED NIGHT. A POTENT VORT MAX WILL RIDE THROUGH THE CAROLINAS AS THE TROUGH LIFTS TOWARD THE NORTHEAST THROUGH EARLY THURS. THIS SHOULD HELP TO SQUEEZE OUT ANY AVAILABLE MOISTURE IN THE ATMOSPHERE WITH BEST UPWARD VV WITHIN THE FEW HOURS SURROUNDING DAYBREAK. BY NOON ON THURS ALL PCP SHOULD MOVE OFF SHORE. PCP WATER VALUES WILL BE RIGHT AROUND A HALF INCH WITH MOISTURE PROFILES SHOWING BEST SATURATION IN THE LAYER BETWEEN BETWEEN 1500 FT AND 5K FT THROUGH THURS MORNING. OVERALL NOT MUCH MOISTURE TO WORK WITH AND BORDERLINE TEMP PROFILES UP THROUGH THE ATMOSPHERE TO PRODUCE SNOW. IT WILL BE TRICKY AS TO HOW FAST THE COLD AIR MOVES IN VS. HOW MUCH LINGERING MOISTURE THERE IS TO SQUEEZE OUT. SFC FRONT BRINGS COOLER AIR IN AFTER MIDNIGHT AT THE SURFACE BUT WARM NOSE ALOFT STILL EVIDENT THROUGH EARLY MORNING WITH CAA INCREASING THROUGH LATE MORNING AS WINDS SHIFT AROUND TO THE NW ALOFT...BUT THIS WILL ALSO INCREASE DRYING THROUGH THE AFTERNOON...PLUS DIURNAL WARMING WILL OCCUR. THEREFORE THERE WILL BE A VERY SMALL WINDOW OF OPPORTUNITY FOR ANY MIXED PCP OR SNOW TO FALL...ESPECIALLY ALONG THE COAST. INLAND WILL HAVE A SLIGHTLY BETTER CHC AS THEY WILL SEE COOLER AIR MOVE IN ALOFT BEFORE DAYBREAK WHICH SHOULD ALLOW FOR SOME LIGHT SNOW. SURFACE WET BULB TEMPS REMAIN RIGHT AROUND FREEZING AND DEWPOINT TEMPS WILL BE DROPPING THROUGH THE EARLY MORNING HOURS REACHING BELOW FREEZING INLAND SEVERAL HOURS BEFORE DAYBREAK BUT JUST AROUND DAYBREAK CLOSE TO THE COAST. THEREFORE WITH EVAPORATIVE COOLING TAKEN INTO EFFECT...WOULD SAY LIKELIHOOD OF ANY MIXED PCP WILL BE INLAND. FOR NOW WILL INCLUDE SOME MIXED PCP INLAND BUT WILL KEEP RAIN ALONG THE COAST...BUT WOULD NOT DISCOUNT SOME SNOW MIXING IN BEFORE IT ALL ENDS. ALL PCP WILL END BY NOON AS SUBSIDENCE AND FURTHER DRYING OCCURS ON BACK END OF SYSTEM AND TEMPS REACH UP CLOSE TO 40 DEGREES. CLEARING WILL OCCUR THROUGH LATE WEDNESDAY WITH TEMPS DROPPING INTO THE LOW TO MID 30S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 300 PM TUESDAY...DEEP LONGWAVE TROUGH TO PLAGUE THE EAST COAST ONCE AGAIN FOR THE FIRST HALF OF THE EXTENDED. THICKNESSES ARE EXPECTED TO INCREASE EARLY NEXT WEEK...BEFORE COLD TROUGH RELOADS ONCE AGAIN AND PUSHES SOUTH BY THE END OF THE PERIOD. FAST AND ACTIVE FLOW CONTINUES...IN A PATTERN THAT HAS PERSISTED THE ENTIRE WINTER THUS FAR. DEEP LONGWAVE TROUGH WILL HAVE ITS AXIS WEST OF THE LOCAL AREA AT THE START OF THE PERIOD...WITH A STRONG VORT SWINGING THROUGH THE BASE BY SATURDAY MORNING. THIS DRIVES A COLD FRONT ACROSS THE CAROLINAS...AND ALTHOUGH GUIDANCE HINTS AT SOME PRECIP FRIDAY NIGHT...PLAN TO KEEP INHERITED DRY FORECAST AS THETA-E RIDGE REMAINS DISPLACED OFFSHORE AND PWATS ARE QUITE LOW. BIGGER IMPACT WILL BE STRONG CAA...WITH 850MB TEMPS DROPPING TO AROUND -10C EARLY SATURDAY MORNING. CANADIAN HIGH PRESSURE BUILDS INTO THE AREA BEHIND THIS FRONT...COINCIDENT WITH THE UPPER TROUGH RELOADING AS A SECOND VORT SWINGS THROUGH...WITH THE BEST FORCING AGAIN REMAINING NORTH OF THE LOCAL AREA. THIS SUGGESTS TEMPS WELL BELOW CLIMO FOR THE WKND...AS ANOTHER REINFORCING SHOT OF COLD AIR OCCURS LATE SUNDAY. ONCE AGAIN...DO NOT ANTICIPATE ANY PRECIP WITH THESE FEATURES...BUT WINTRY PRECIP WON`T BE TOO FAR REMOVED TO THE NORTH. MORE SEASONABLE WEATHER EXPECTED FOR EARLY WEEK AS A RENEWED TROUGH BEGINS TO DIVE INTO THE MIDDLE PART OF THE COUNTRY...DRIVING DOWNSTREAM RIDGING ACROSS THE EAST. THIS PUSHES THE HIGH PRESSURE OFFSHORE...WHICH...ALTHOUGH IT WEAKENS CREATING A RATHER DIFFUSE PRESSURE GRADIENT...STILL PROMOTES SW RETURN FLOW AND TEMPS RISING TO CLIMO OR SLIGHTLY ABOVE MON/TUE. THIS SETS THE STAGE FOR BETTER PRECIP CHANCES BEGINNING AT THE END OF THE PERIOD AS ANOTHER SHORTWAVE DIVES ACROSS THE AREA. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...MVFR/IFR/POSSIBLE LIFR DUE TO FOG TONIGHT THROUGH THE MORNING HOURS ON WEDNESDAY. OTHERWISE EXPECT VFR. VFR PREVAILS THIS EVENING WITH THE EXCEPTION OF KLBT WHICH HAS ALREADY OBSERVED FOG VARYING BETWEEN MVFR AND IFR...WITH PERIODS OF VFR AS WELL. GIVEN AVAILABLE LOW LEVEL MOISTURE AS NOTED BY SMALL DEWPOINT DEPRESSIONS...LIGHT WINDS...AND MAINLY FEW/SCT CIRRUS CLOUDS...EXPECT WIDESPREAD FOG ACROSS THE AREA TONIGHT AND OVERNIGHT VARYING BETWEEN MVFR...IFR...AND POSSIBLE LIFR CONDITIONS...ESPECIALLY AT THE INLAND SITES AND KCRE. AFTER DAYBREAK...FOG WILL QUICKLY DISPERSE ALLOWING FOR VFR TO PREVAIL THROUGH THE REMAINDER OF THE TAF PERIOD. LIGHT AND VARIABLE WINDS EXPECTED WITH FEW/SCT/BKN HIGH CLOUDS. EXTENDED OUTLOOK...A SLIGHT CHANCE OF PRECIP THURSDAY MORNING. OTHERWISE EXPECT VFR THROUGH THE PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 730 PM TUESDAY...COLD FRONT HAS PUSHED THRU THE ILM WATERS AND IS NOW JUST OFFSHORE. INITIAL POST COLD FRONTAL WINDS WILL BLOW WNW-NNW AT 10 TO 20 KT. THE SFC PG WILL QUICKLY BEGIN TO RELAX AFTER MIDNIGHT...ALONG WITH CAA BECOMING NEUTRAL BY DAYBREAK WED. OVERALL...WINDS WILL DIMINISH TO AROUND 10 KT DURING THE PRE-DAWN WED HRS. SIGNIFICANT SEAS HAVE ALREADY DROPPED BELOW SCA CRITERIA...AND WILL FURTHER SUBSIDE DUE TO THE AID OF A POST COLD FRONTAL OFF-SHORE WIND TRAJECTORY. OVERALL...SHOULD SEE SIGNIFICANT SEAS DROP INTO THE 2 TO 4 FOOT RANGE BY DAYBREAK WED. AVERAGE PERIODS WILL RANGE BETWEEN 5.0 TO 5.5 SECONDS. PREVIOUS DISCUSSION............................................ AS OF 300 AM TUESDAY...THE DENSE FOG ADVISORY WILL BE ALLOWED TO EXPIRE AT 3 PM AS IT CONTINUE TO SLOWLY DISSIPATE AND ADVECT TO THE NORTH NORTHEAST AHEAD OF A SLOW MOVING FRONT FOR THE WATERS MAINLY SOUTH OF LITTLE RIVER INLET. THE FRONTAL PASSAGE ACROSS THE WATERS IS EXPECTED AFTER 7 PM AND WITH THIS FRONT A GOOD PUSH OF OFFSHORE FLOW IS EXPECTED AND THE SEAS WILL FALL BELOW SMALL CRAFT CONDITIONS AT 8 PM SOUTH OF LITTLE RIVER INLET AND 2 AM FOR THE WATERS TO THE NORTH. SEAS SHOULD RELAX LATE AND WILL BEGIN AT 4 TO 6 FEET BUT WILL SETTLE OUT TO A RANGE OF 2 FEET NEAR SHORE AND 5 FEET AT 20 MILES OFF THE COAST. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...WILL BE IN BETWEEN TWO FRONTS ON WED WITH ONE EXITING FURTHER INTO THE ATLANTIC AND ONE MARCHING EAST TOWARD THE CAROLINAS. WINDS WILL BACK AROUND ON WEDNESDAY WITH LIGHT W-SW WINDS TO START. AS THE DAY PROGRESSES WINDS WILL INCREASE TO 15-20 KNOTS AS A COLD FRONT APPROACHES. THIS FRONT WILL MOVE ACROSS THE WATERS AFTER MIDNIGHT WED NIGHT INTO EARLY THURS MORNING WITH WINDS VEERING AROUND TO THE NORTHWEST UP NEAR 20 KTS. A VERY PROGRESSIVE FLOW CONTINUES WITH WINDS BACKING TO THE WEST AS YET ANOTHER FRONT APPROACHES THE CAROLINAS ON FRIDAY. SEAS WILL REMAIN FAIRLY BENIGN WITH 1 TO 3 FT SEAS INCREASING TO 2-4 FEET BY WED NIGHT INTO THURS. MAY SEE A FEW 5 FTERS IN OUTER WATERS AS WINDS SPIKE UP ON THURS. A SHARP RISE WILL BEGIN JUST AT THE END OF THE SHORT TERM PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 300 PM TUESDAY...TWO COLD FRONTS WILL CROSS THE WATERS DURING THE PERIOD...ONE SATURDAY MORNING...AND ANOTHER SUNDAY EVE. THIS CREATES TWO PERIODS OF INCREASED WINDS...AND MUCH OF THE PERIOD WILL FEATURE UNSETTLED MARINE CONDITIONS. AHEAD OF THE FIRST FRONT ON FRIDAY...SW WINDS WILL INCREASE TO 15-25 KTS FRIDAY NIGHT...DRIVING SEAS UP TO 4-7 FT...AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FRIDAY INTO SATURDAY. COLD FRONT CROSSES OVERNIGHT INTO SATURDAY MORNING...TURNING WINDS TO THE NW AT 15-25 KTS BEFORE EASING THROUGH SATURDAY...AND THE HIGHEST SEAS GET PUSHED AWAY FROM SHORE. THIS LEAVES 2-4 FT SEAS MUCH OF SATURDAY. WINDS BACK TO THE WEST AGAIN ON SUNDAY AND INCREASE TO 15-20 KTS AHEAD OF THE NEXT...WEAKER...COLD FRONT LATE IN THE DAY...WHICH AGAIN TURNS WINDS TO THE NW AT THE END OF THE PERIOD. SEAS WILL BUILD AGAIN TO 3-5 FT DURING SUNDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...DCH/DRH SHORT TERM...RGZ LONG TERM...JDW AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
706 PM EST TUE JAN 14 2014 .SYNOPSIS... A COLD FRONT WILL MOVE OFF THE COAST THIS EVENING FOLLOWED BY ANOTHER COLD FRONT WEDNESDAY NIGHT. A STRONGER COLD FRONT WILL CROSS THE AREA LATE FRIDAY FOLLOWED BY A REINFORCING SHOT OF COLD AIR ON SUNDAY. DRY HIGH PRESSURE WILL BUILD INTO THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM TUESDAY...THE COLD FRONT CONTINUES TO PRESS EASTWARD AS IT IS APPROACHES RALEIGH BUT IS IT STILL LAGS A BIT TO THE SOUTH. A POSSIBLE PREFRONTAL TROUGH IS RUNNING AHEAD OF THE FRONT TO THE SOUTH. THE 18Z UTC RUC IS SHOWING THE 850 LOW LEVEL JET MAX CENTERED OVER SOUTH CAROLINA AND THIS FEATURE WILL SHIFT NORTH OUT OF THE AREA BY 22 UTC. THIS APPEARS TO BE THE WHAT IS ENHANCING THE LOW TOP CONVECTION IN INLAND AREAS OF SOUTHEAST NORTH CAROLINA. SEA FOG IS NOW BREAKING UP ALONG THE GEORGETOWN COAST AND WILL LINGER FOR THE NEXT HALF HOUR BEFORE BECOMING A NONE FACTOR. MODELS STILL CONTINUE TO BRING A FRONT TO THE COAST BY 7 PM BUT THE MODELS MAINTAIN A GOOD CHANCE OF SHOWERS EARLY THEN SLOWLY TAPER THE RAIN OFF OVERNIGHT. QPF VALUES APPEAR TO BE LESS THAN A HALF OF AN INCH. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...WILL A LITTLE SNOW FALL EARLY THURS OR NOT IS THE QUESTION... A WAVE OF LOW PRESSURE WILL MOVE UP ALONG COLD FRONT WELL OFF SHORE IN DEEP SW FLOW AHEAD OF DEEPENING TROUGH DIGGING DOWN FROM THE GREAT LAKES TOWARD THE GULF COAST ON WED. EXPECT SUNNY AND DRY WEATHER AHEAD OF THIS SYSTEM WITH TEMPS UP CLOSER TO 60 BUT THIS TROUGH WILL ADVANCE EASTWARD THROUGH WEDNESDAY PUSHING ANOTHER COLD FRONT INTO AND THROUGH THE CAROLINAS WED NIGHT. A POTENT VORT MAX WILL RIDE THROUGH THE CAROLINAS AS THE TROUGH LIFTS TOWARD THE NORTHEAST THROUGH EARLY THURS. THIS SHOULD HELP TO SQUEEZE OUT ANY AVAILABLE MOISTURE IN THE ATMOSPHERE WITH BEST UPWARD VV WITHIN THE FEW HOURS SURROUNDING DAYBREAK. BY NOON ON THURS ALL PCP SHOULD MOVE OFF SHORE. PCP WATER VALUES WILL BE RIGHT AROUND A HALF INCH WITH MOISTURE PROFILES SHOWING BEST SATURATION IN THE LAYER BETWEEN BETWEEN 1500 FT AND 5K FT THROUGH THURS MORNING. OVERALL NOT MUCH MOISTURE TO WORK WITH AND BORDERLINE TEMP PROFILES UP THROUGH THE ATMOSPHERE TO PRODUCE SNOW. IT WILL BE TRICKY AS TO HOW FAST THE COLD AIR MOVES IN VS. HOW MUCH LINGERING MOISTURE THERE IS TO SQUEEZE OUT. SFC FRONT BRINGS COOLER AIR IN AFTER MIDNIGHT AT THE SURFACE BUT WARM NOSE ALOFT STILL EVIDENT THROUGH EARLY MORNING WITH CAA INCREASING THROUGH LATE MORNING AS WINDS SHIFT AROUND TO THE NW ALOFT...BUT THIS WILL ALSO INCREASE DRYING THROUGH THE AFTERNOON...PLUS DIURNAL WARMING WILL OCCUR. THEREFORE THERE WILL BE A VERY SMALL WINDOW OF OPPORTUNITY FOR ANY MIXED PCP OR SNOW TO FALL...ESPECIALLY ALONG THE COAST. INLAND WILL HAVE A SLIGHTLY BETTER CHC AS THEY WILL SEE COOLER AIR MOVE IN ALOFT BEFORE DAYBREAK WHICH SHOULD ALLOW FOR SOME LIGHT SNOW. SURFACE WET BULB TEMPS REMAIN RIGHT AROUND FREEZING AND DEWPOINT TEMPS WILL BE DROPPING THROUGH THE EARLY MORNING HOURS REACHING BELOW FREEZING INLAND SEVERAL HOURS BEFORE DAYBREAK BUT JUST AROUND DAYBREAK CLOSE TO THE COAST. THEREFORE WITH EVAPORATIVE COOLING TAKEN INTO EFFECT...WOULD SAY LIKELIHOOD OF ANY MIXED PCP WILL BE INLAND. FOR NOW WILL INCLUDE SOME MIXED PCP INLAND BUT WILL KEEP RAIN ALONG THE COAST...BUT WOULD NOT DISCOUNT SOME SNOW MIXING IN BEFORE IT ALL ENDS. ALL PCP WILL END BY NOON AS SUBSIDENCE AND FURTHER DRYING OCCURS ON BACK END OF SYSTEM AND TEMPS REACH UP CLOSE TO 40 DEGREES. CLEARING WILL OCCUR THROUGH LATE WEDNESDAY WITH TEMPS DROPPING INTO THE LOW TO MID 30S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 300 PM TUESDAY...DEEP LONGWAVE TROUGH TO PLAGUE THE EAST COAST ONCE AGAIN FOR THE FIRST HALF OF THE EXTENDED. THICKNESSES ARE EXPECTED TO INCREASE EARLY NEXT WEEK...BEFORE COLD TROUGH RELOADS ONCE AGAIN AND PUSHES SOUTH BY THE END OF THE PERIOD. FAST AND ACTIVE FLOW CONTINUES...IN A PATTERN THAT HAS PERSISTED THE ENTIRE WINTER THUS FAR. DEEP LONGWAVE TROUGH WILL HAVE ITS AXIS WEST OF THE LOCAL AREA AT THE START OF THE PERIOD...WITH A STRONG VORT SWINGING THROUGH THE BASE BY SATURDAY MORNING. THIS DRIVES A COLD FRONT ACROSS THE CAROLINAS...AND ALTHOUGH GUIDANCE HINTS AT SOME PRECIP FRIDAY NIGHT...PLAN TO KEEP INHERITED DRY FORECAST AS THETA-E RIDGE REMAINS DISPLACED OFFSHORE AND PWATS ARE QUITE LOW. BIGGER IMPACT WILL BE STRONG CAA...WITH 850MB TEMPS DROPPING TO AROUND -10C EARLY SATURDAY MORNING. CANADIAN HIGH PRESSURE BUILDS INTO THE AREA BEHIND THIS FRONT...COINCIDENT WITH THE UPPER TROUGH RELOADING AS A SECOND VORT SWINGS THROUGH...WITH THE BEST FORCING AGAIN REMAINING NORTH OF THE LOCAL AREA. THIS SUGGESTS TEMPS WELL BELOW CLIMO FOR THE WKND...AS ANOTHER REINFORCING SHOT OF COLD AIR OCCURS LATE SUNDAY. ONCE AGAIN...DO NOT ANTICIPATE ANY PRECIP WITH THESE FEATURES...BUT WINTRY PRECIP WON`T BE TOO FAR REMOVED TO THE NORTH. MORE SEASONABLE WEATHER EXPECTED FOR EARLY WEEK AS A RENEWED TROUGH BEGINS TO DIVE INTO THE MIDDLE PART OF THE COUNTRY...DRIVING DOWNSTREAM RIDGING ACROSS THE EAST. THIS PUSHES THE HIGH PRESSURE OFFSHORE...WHICH...ALTHOUGH IT WEAKENS CREATING A RATHER DIFFUSE PRESSURE GRADIENT...STILL PROMOTES SW RETURN FLOW AND TEMPS RISING TO CLIMO OR SLIGHTLY ABOVE MON/TUE. THIS SETS THE STAGE FOR BETTER PRECIP CHANCES BEGINNING AT THE END OF THE PERIOD AS ANOTHER SHORTWAVE DIVES ACROSS THE AREA. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...MVFR/IFR/POSSIBLE LIFR DUE TO FOG TONIGHT THROUGH THE MORNING HOURS ON WEDNESDAY. OTHERWISE EXPECT VFR. VFR PREVAILS THIS EVENING WITH THE EXCEPTION OF KLBT WHICH HAS ALREADY OBSERVED FOG VARYING BETWEEN MVFR AND IFR...WITH PERIODS OF VFR AS WELL. GIVEN AVAILABLE LOW LEVEL MOISTURE AS NOTED BY SMALL DEWPOINT DEPRESSIONS...LIGHT WINDS...AND MAINLY FEW/SCT CIRRUS CLOUDS...EXPECT WIDESPREAD FOG ACROSS THE AREA TONIGHT AND OVERNIGHT VARYING BETWEEN MVFR...IFR...AND POSSIBLE LIFR CONDITIONS...ESPECIALLY AT THE INLAND SITES AND KCRE. AFTER DAYBREAK...FOG WILL QUICKLY DISPERSE ALLOWING FOR VFR TO PREVAIL THROUGH THE REMAINDER OF THE TAF PERIOD. LIGHT AND VARIABLE WINDS EXPECTED WITH FEW/SCT/BKN HIGH CLOUDS. EXTENDED OUTLOOK...A SLIGHT CHANCE OF PRECIP THURSDAY MORNING. OTHERWISE EXPECT VFR THROUGH THE PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM TUESDAY...THE DENSE FOG ADVISORY WILL BE ALLOWED TO EXPIRE AT 3 PM AS IT CONTINUE TO SLOWLY DISSIPATE AND ADVECT TO THE NORTH NORTHEAST AHEAD OF A SLOW MOVING FRONT FOR THE WATERS MAINLY SOUTH OF LITTLE RIVER INLET. THE FRONTAL PASSAGE ACROSS THE WATERS IS EXPECTED AFTER 7 PM AND WITH THIS FRONT A GOOD PUSH OF OFFSHORE FLOW IS EXPECTED AND THE SEAS WILL FALL BELOW SMALL CRAFT CONDITIONS AT 8 PM SOUTH OF LITTLE RIVER INLET AND 2 AM FOR THE WATERS TO THE NORTH. SEAS SHOULD RELAX LATE AND WILL BEGIN AT 4 TO 6 FEET BUT WILL SETTLE OUT TO A RANGE OF 2 FEET NEAR SHORE AND 5 FEET AT 20 MILES OFF THE COAST. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...WILL BE IN BETWEEN TWO FRONTS ON WED WITH ONE EXITING FURTHER INTO THE ATLANTIC AND ONE MARCHING EAST TOWARD THE CAROLINAS. WINDS WILL BACK AROUND ON WEDNESDAY WITH LIGHT W-SW WINDS TO START. AS THE DAY PROGRESSES WINDS WILL INCREASE TO 15-20 KNOTS AS A COLD FRONT APPROACHES. THIS FRONT WILL MOVE ACROSS THE WATERS AFTER MIDNIGHT WED NIGHT INTO EARLY THURS MORNING WITH WINDS VEERING AROUND TO THE NORTHWEST UP NEAR 20 KTS. A VERY PROGRESSIVE FLOW CONTINUES WITH WINDS BACKING TO THE WEST AS YET ANOTHER FRONT APPROACHES THE CAROLINAS ON FRIDAY. SEAS WILL REMAIN FAIRLY BENIGN WITH 1 TO 3 FT SEAS INCREASING TO 2-4 FEET BY WED NIGHT INTO THURS. MAY SEE A FEW 5 FTERS IN OUTER WATERS AS WINDS SPIKE UP ON THURS. A SHARP RISE WILL BEGIN JUST AT THE END OF THE SHORT TERM PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 300 PM TUESDAY...TWO COLD FRONTS WILL CROSS THE WATERS DURING THE PERIOD...ONE SATURDAY MORNING...AND ANOTHER SUNDAY EVE. THIS CREATES TWO PERIODS OF INCREASED WINDS...AND MUCH OF THE PERIOD WILL FEATURE UNSETTLED MARINE CONDITIONS. AHEAD OF THE FIRST FRONT ON FRIDAY...SW WINDS WILL INCREASE TO 15-25 KTS FRIDAY NIGHT...DRIVING SEAS UP TO 4-7 FT...AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED FRIDAY INTO SATURDAY. COLD FRONT CROSSES OVERNIGHT INTO SATURDAY MORNING...TURNING WINDS TO THE NW AT 15-25 KTS BEFORE EASING THROUGH SATURDAY...AND THE HIGHEST SEAS GET PUSHED AWAY FROM SHORE. THIS LEAVES 2-4 FT SEAS MUCH OF SATURDAY. WINDS BACK TO THE WEST AGAIN ON SUNDAY AND INCREASE TO 15-20 KTS AHEAD OF THE NEXT...WEAKER...COLD FRONT LATE IN THE DAY...WHICH AGAIN TURNS WINDS TO THE NW AT THE END OF THE PERIOD. SEAS WILL BUILD AGAIN TO 3-5 FT DURING SUNDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ250- 252. && $$ NEAR TERM...DRH SHORT TERM...RGZ LONG TERM...JDW AVIATION...SGL
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
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 GRAND FORKS ND
939 PM CST TUE JAN 14 2014 .UPDATE... ISSUED AT 930 PM CST TUE JAN 14 2014 CLOUD TRENDS AND TEMPERATURES WILL CONTINUE TO BE A CHALLENGE TONIGHT. N-S ORIENTED CLOUD BAND CONTINUES TO SHIFT SLOWLY EAST WITH CLEARING APPROACHING THE RED RIVER PROPER. ABOVE CLOUD BAND HAS HELD TEMPERATURES UP AND WITH SLOW MOVEMENT ADJUSTED TEMPERATURES UP ACROSS W MN. FARTHER WEST ADVANCING CLOUDS/WARM ADVECTION SHOULD LEVEL OFF TEMPERATURES. THIS WILL LEAVE COLDEST TEMPERATURES TONIGHT ACROSS NORTHERN AREAS. MINOR TEMPERATURE AND CLOUD TREND ADJUSTMENTS MAIN CHANGES THIS UPDATE. UPDATE ISSUED AT 620 PM CST TUE JAN 14 2014 EASTWARD PROPAGATION OF CLOUD BAND OVER THE VALLEY HAS SLOWED UP ALLOWING TEMPERATURES TO HOLD UP EARLY THIS EVENING. WILL LEAVE MINIMUMS AS IS AT THIS POINT BUT WILL NEED TO MONITOR CLEARING TRENDS. ONLY CHANGES WERE TO ADJUST CLOUD TRENDS AND EVENING TEMPERATURE CURVE. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 318 PM CST TUE JAN 14 2014 SKY COVER AND TEMPS THE ISSUE TONIGHT. BAND OF STRATOCU CU OVER ERN ND ATTM AND HOW/WHEN THIS CLEARS OUT WILL BE THE ISSUE FOR LOW TEMPS. HRRR AND OTHER SHORT TERM MODELS DO BRING CLEARING TO ERN ND/RRV THIS EVE AND SPREADS IT EAST. WINDS WILL DIMINISH TOO AND WITH LIKELY CLEARING/CLEAR SKY FOR A WHILE TEMPS WILL DROP QUICKLY INTO THE 5 TO 10 BELOW ZERO RANGE MOST AREAS WITH A FEW TEEN BELOW ZERO TEMPS LIKELY IN PARTS OF FAR NW MN. CLOUDS FROM NEXT SYSTEM WILL SPREAD INTO WRN FCST AREA AFTER MIDNIGHT AS WINDS TURN SOUTH AND TEMPS WARM...SO PERIOD OF COLD TEMPS IS SMALL. STRONG 925-850 MB WARM ADVECTION WILL SPREAD WEST TO EAST OVER THE AREA WEDNESDAY...WITH BAND OF LIGHT SNOW WITH IT ENDING AS SOME SLEET/FREEZING RAIN AT THE TAIL END. BUT MODELS DO APPEAR TO BUT MOST OF THE MOISTURE IN THE COLD AIR TO THE EAST OF THE WARM FRONT SO THINK ICING WILL BE MINIMAL. THUS NO ADVISORIES ISSUED. BUT LATER SHIFTS CAN MONITOR. TEMPS WILL WARM SIGNIFICANTLY WED AFTN OVER ERN ND WITH TEMPS 32F OR HIGHER AS 925 MB REACH +2C. IT WILL BE TURN WINDY AS WELL ESP WEST OF THE VALLEY WHERE 45-50 KT 925 MB WINDS WILL BE PRESENT. HOWEVER WITH WARMER AIR COMING OVER THE COLDER SURFACE AN INVERSION WILL BE PRESENT AND THUS MIXING WILL BE LIMITED. THUS DONT ANTICIPATE ANY HEADLINES FOR WIND/BLSN WED AFTN/EVE. VERY CLOSE THOUGH WED EVE AND WILL NEED TO WATCH WIND POTENTIAL. ARCTIC FRONT WILL START DROPPING SOUTH INTO THE FAR NRN VALLEY 06Z-09Z AND THEN PLUNGE SOUTH REACHING FAR SRN FCST AREA SOON AFTER 12Z THU. 925 MB WINDS OF 50 KTS BECOME MORE NORTH-SOUTH AND WITH STRONG SURFACE COOLING SOUNDINGS SHOW ADIABATIC CONDITIONS UP TO AROUND 870 MB. THUS EXPECT THE FRONT TO ARRIVE WITH A STRONG PUNCH ALONG WITH SOME SNOW SHOWERS. THUS EXPECT A QUICK DOWNTURN INTO BLIZZARD CONDITIONS JUST AHEAD AND BEHIND FRONT THRU THE LATE NIGHT WED NIGHT. DID NOT INCLUDE THE FAR EAST (TREES) IN BLIZZARD WATCH. WHILE SNOWFALL WILL END IN ERN ND/RRV WED NIGHT DO LOOK FOR SOME LIGHT SNOW TO LINGER OVER LAKE OF THE WOODS REGION..WHERE TOTAL NEW SNOWFALL OF 1-3 INCHES IS POSSIBLE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 318 PM CST TUE JAN 14 2014 THURSDAY SHOULD SEE BLIZZARD CONDITIONS OVER THE PRAIRIE REGION....ERN ND/RRV (ROX-FFM WESTWARD). STRONG COLD ADVECTION STRONG LAPSE RATES WITH GOOD MIXING OF 50 KT 925 MB WINDS TO THE SFC SHOULD ENSURE BLOWING SNOW AND NEAR ZERO VISIBILITY AT TIMES...ESP OUT OF TOWN. ANY FALLING SNOWFALL WILL ADD TO THE VSBY ISSUES. IT WILL BE A FAST MOVING BLIZZARD IN THAT CONDITIONS WILL IMPROVE LATE IN THE DAY IN THE NORTH AND IN THE EARLY EVENING IN THE SOUTH. CONDITIONS MUCH IMPROVED BY 12Z FRI AS SFC HIGH AND CLEARING MOVE IN WITH LIGHTER WINDS. NEXT WEAK SHORTWAVE WILL MOVE INTO ERN ND FRI AFTN WITH SOME LIGHT SNOW/FLURRIES. FOR THE FRIDAY NIGHT TO TUESDAY TIME FRAME THE FA REMAINS IN NORTHWEST FLOW ALOFT. ONE WEAK SFC LOW PASSES THROUGH THE AREA FRI NIGHT SO LEFT SOME LIGHT SNOW CHANCES WITH IT. ANOTHER WEAK WAVE AND ASSOCIATED SFC LOW PASS NORTH OF THE FA SUN NIGHT WHICH COULD RESULT IN SOME LIGHT SNOW AGAIN MON AND MON NIGHT. NEITHER SYSTEM AT THIS POINT LOOKS VERY IMPRESSIVE FOR PRODUCING MUCH SNOW. THE UP AND DOWN TEMP PATTERN LOOKS TO CONTINUE WITH WARMER AIR MOVING BACK IN ESPECIALLY BY THE WEEKEND FOLLOWED BY COOLER TEMPS FOR EARLY NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 620 PM CST TUE JAN 14 2014 CLEARING OF MVFR CIGS THROUGH THE VALLEY HAS SLOWED UP BUT STILL EXPECT GRADUAL CLEARING TO OCCUR. EASTERN LOCALS MAY SEE LOWER CIGS MOVE IN AND COULD HOLD TIL LATE TONIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR NDZ038-039-049-052-053. BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR NDZ006>008-014>016-024-026>030-054. MN...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR MNZ002-003-022-027-029-030-040. BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR MNZ001-004-005-007-008-013>015. && $$ UPDATE...VOELKER SHORT TERM...RIDDLE LONG TERM...GODON/RIDDLE AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
631 PM CST TUE JAN 14 2014 .UPDATE... ISSUED AT 620 PM CST TUE JAN 14 2014 EASTWARD PROPAGATION OF CLOUD BAND OVER THE VALLEY HAS SLOWED UP ALLOWING TEMPERATURES TO HOLD UP EARLY THIS EVENING. WILL LEAVE MINIMUMS AS IS AT THIS POINT BUT WILL NEED TO MONITOR CLEARING TRENDS. ONLY CHANGES WERE TO ADJUST CLOUD TRENDS AND EVENING TEMPERATURE CURVE. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 318 PM CST TUE JAN 14 2014 SKY COVER AND TEMPS THE ISSUE TONIGHT. BAND OF STRATOCU CU OVER ERN ND ATTM AND HOW/WHEN THIS CLEARS OUT WILL BE THE ISSUE FOR LOW TEMPS. HRRR AND OTHER SHORT TERM MODELS DO BRING CLEARING TO ERN ND/RRV THIS EVE AND SPREADS IT EAST. WINDS WILL DIMINISH TOO AND WITH LIKELY CLEARING/CLEAR SKY FOR A WHILE TEMPS WILL DROP QUICKLY INTO THE 5 TO 10 BELOW ZERO RANGE MOST AREAS WITH A FEW TEEN BELOW ZERO TEMPS LIKELY IN PARTS OF FAR NW MN. CLOUDS FROM NEXT SYSTEM WILL SPREAD INTO WRN FCST AREA AFTER MIDNIGHT AS WINDS TURN SOUTH AND TEMPS WARM...SO PERIOD OF COLD TEMPS IS SMALL. STRONG 925-850 MB WARM ADVECTION WILL SPREAD WEST TO EAST OVER THE AREA WEDNESDAY...WITH BAND OF LIGHT SNOW WITH IT ENDING AS SOME SLEET/FREEZING RAIN AT THE TAIL END. BUT MODELS DO APPEAR TO BUT MOST OF THE MOISTURE IN THE COLD AIR TO THE EAST OF THE WARM FRONT SO THINK ICING WILL BE MINIMAL. THUS NO ADVISORIES ISSUED. BUT LATER SHIFTS CAN MONITOR. TEMPS WILL WARM SIGNIFICANTLY WED AFTN OVER ERN ND WITH TEMPS 32F OR HIGHER AS 925 MB REACH +2C. IT WILL BE TURN WINDY AS WELL ESP WEST OF THE VALLEY WHERE 45-50 KT 925 MB WINDS WILL BE PRESENT. HOWEVER WITH WARMER AIR COMING OVER THE COLDER SURFACE AN INVERSION WILL BE PRESENT AND THUS MIXING WILL BE LIMITED. THUS DONT ANTICIPATE ANY HEADLINES FOR WIND/BLSN WED AFTN/EVE. VERY CLOSE THOUGH WED EVE AND WILL NEED TO WATCH WIND POTENTIAL. ARCTIC FRONT WILL START DROPPING SOUTH INTO THE FAR NRN VALLEY 06Z-09Z AND THEN PLUNGE SOUTH REACHING FAR SRN FCST AREA SOON AFTER 12Z THU. 925 MB WINDS OF 50 KTS BECOME MORE NORTH-SOUTH AND WITH STRONG SURFACE COOLING SOUNDINGS SHOW ADIABATIC CONDITIONS UP TO AROUND 870 MB. THUS EXPECT THE FRONT TO ARRIVE WITH A STRONG PUNCH ALONG WITH SOME SNOW SHOWERS. THUS EXPECT A QUICK DOWNTURN INTO BLIZZARD CONDITIONS JUST AHEAD AND BEHIND FRONT THRU THE LATE NIGHT WED NIGHT. DID NOT INCLUDE THE FAR EAST (TREES) IN BLIZZARD WATCH. WHILE SNOWFALL WILL END IN ERN ND/RRV WED NIGHT DO LOOK FOR SOME LIGHT SNOW TO LINGER OVER LAKE OF THE WOODS REGION..WHERE TOTAL NEW SNOWFALL OF 1-3 INCHES IS POSSIBLE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 318 PM CST TUE JAN 14 2014 THURSDAY SHOULD SEE BLIZZARD CONDITIONS OVER THE PRAIRIE REGION....ERN ND/RRV (ROX-FFM WESTWARD). STRONG COLD ADVECTION STRONG LAPSE RATES WITH GOOD MIXING OF 50 KT 925 MB WINDS TO THE SFC SHOULD ENSURE BLOWING SNOW AND NEAR ZERO VISIBILITY AT TIMES...ESP OUT OF TOWN. ANY FALLING SNOWFALL WILL ADD TO THE VSBY ISSUES. IT WILL BE A FAST MOVING BLIZZARD IN THAT CONDITIONS WILL IMPROVE LATE IN THE DAY IN THE NORTH AND IN THE EARLY EVENING IN THE SOUTH. CONDITIONS MUCH IMPROVED BY 12Z FRI AS SFC HIGH AND CLEARING MOVE IN WITH LIGHTER WINDS. NEXT WEAK SHORTWAVE WILL MOVE INTO ERN ND FRI AFTN WITH SOME LIGHT SNOW/FLURRIES. FOR THE FRIDAY NIGHT TO TUESDAY TIME FRAME THE FA REMAINS IN NORTHWEST FLOW ALOFT. ONE WEAK SFC LOW PASSES THROUGH THE AREA FRI NIGHT SO LEFT SOME LIGHT SNOW CHANCES WITH IT. ANOTHER WEAK WAVE AND ASSOCIATED SFC LOW PASS NORTH OF THE FA SUN NIGHT WHICH COULD RESULT IN SOME LIGHT SNOW AGAIN MON AND MON NIGHT. NEITHER SYSTEM AT THIS POINT LOOKS VERY IMPRESSIVE FOR PRODUCING MUCH SNOW. THE UP AND DOWN TEMP PATTERN LOOKS TO CONTINUE WITH WARMER AIR MOVING BACK IN ESPECIALLY BY THE WEEKEND FOLLOWED BY COOLER TEMPS FOR EARLY NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 620 PM CST TUE JAN 14 2014 CLEARING OF MVFR CIGS THROUGH THE VALLEY HAS SLOWED UP BUT STILL EXPECT GRADUAL CLEARING TO OCCUR. EASTERN LOCALS MAY SEE LOWER CIGS MOVE IN AND COULD HOLD TIL LATE TONIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR NDZ038-039-049-052-053. BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR NDZ006>008-014>016-024-026>030-054. MN...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR MNZ002-003-022-027-029-030-040. BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR MNZ001-004-005-007-008-013>015. && $$ UPDATE...VOELKER SHORT TERM...RIDDLE LONG TERM...GODON/RIDDLE AVIATION...VOELKER
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
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
912 PM CST TUE JAN 14 2014 .DISCUSSION...BASED ON RADAR...COLD FRONTAL BDRY IS PUSHING THROUGH THE CWA AND SHOULD REACH CORPUS AROUND 04Z. HAVE MADE SOME TWEAKS TO THE DEWPOINTS AND WINDS BASED ON CURRENT TRENDS BEHIND THE FRONTAL BDRY. THESE TWEAKS INCLUDED LOWERING DEWPOINTS ACROSS THE W CWA BY A FEW DEGREES BASED ON MSAS ANALYSIS WITH DEWPOINTS COMING BACK UP BY A FEW DEGREES OVERNIGHT. ALSO INCREASED WIND SPEEDS BY A COUPLE OF KNOTS. TIMING OF SMALL CRAFT ADVISORY LOOKS GOOD BUT HAVE INCLUDED NRN BAYS IN THE ADVISORY AS WELL. UPDATES WILL BE OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 531 PM CST TUE JAN 14 2014/ DISCUSSION...SEE 00Z AVIATION DISCUSSION. AVIATION...MAIN ISSUE IS TIMING OF FRONT...THEN HOW LONG WINDS STAY UP BEFORE DIMINISHING (AND KEEPING EVERYTHING RELATIVELY SHORT SINCE NO OTHER SIGNIFICANT WEATHER). USING HRRR AND TTU 4 KM MODELS...AM GOING WITH WIND SHIFT ABT 03Z AT KVCT...ABT 04Z AT KRLD AND 05Z AT KCRP/KALI (GIVE OR TAKE 30 MINUTES). AM GOING TO KEEP WINDS UP TIL AT LEAST 12Z...THEN DIMINISH FROM WEST TO EAST DURING THE DAY ON THE 15TH. WITH WINDS UP FOR THE EVENING AND OVERNIGHT PERIOD...WIND SHEAR SHOULD BE NO PROBLEM. OTHERWISE...SKC. PREV DISCUSSION... /ISSUED 325 PM CST TUE JAN 14 2014/ SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...COLD FRONT WILL MOVE THROUGH CWA JUST BEFORE MIDNIGHT TONIGHT...BRINGING NORTHERLY WINDS AROUND 15 KT OVER LAND AND 25 KT OFFSHORE. WEDNESDAY AFTERNOON SHOULD SEE A SURFACE HIGH BEHIND THE FRONT SETTLE INTO THE FORECAST AREA. AS THE CENTER OF HIGH PRESSURE TOMORROW WILL BE LOCATED OVER THE RIO GRANDE VALLEY...EXPECTING LIGHT WESTERLY WINDS. BY TOMORROW NIGHT...SURFACE HIGH PRESSURE WILL SHIFT EAST AND MOVE OVER THE WESTERN GOM WHICH WILL ALLOW ONSHORE FLOW TO RESUME AND INCREASE LOW LEVEL MOISTURE. THE LACK OF ANY MOISTURE WILL KEEP POPS TO ZERO AND KEEP SKIES CLEAR THROUGH THE SHORT TERM. CLEAR SKIES TONIGHT SHOULD ALLOW FOR LOWS IN THE LOWER 40S OVER THE SOUTHERN BRUSH COUNTRY AND SOUTHERN COASTAL BEND AND THE UPPER 30S OVER THE NORTHERN COUNTIES. HIGHS TOMORROW BEHIND THE FRONT WILL BE IN THE 60S ACROSS MOST OF THE AREA WITH SOME UPPER 50S OFFSHORE. COOLER AIR BEHIND THE FRONT AND ANOTHER CLEAR AND CALM NIGHT WILL LEAD TO LOWS IN THE MID 30S INLAND AND LOWER 40S NEAR THE COAST...AS WELL AS THE WESTERN BRUSH COUNTRY. MARINE...INCREASING NORTHERLY WINDS BEHIND TONIGHTS FRONT WILL INCREASE OFFSHORE WINDS TO 20-25 KT BETWEEN 6 AND 18Z. ADDITIONALLY...WAVE HEIGHTS AROUND 7 FEET ARE EXPECTED IN THE OFFSHORE ZONES. A SMALL CRAFT ADVISORY WILL BE IN EFFECT FROM 6 TO 12Z OVER THE SOUTHERN BAYS AND WATERWAYS...AND 6 TO 18Z OVER THE OFFSHORE WATERS. TOMORROW AFTERNOON WILL SEE A RETURN TO CALMER CONDITIONS. LONG TERM (THURSDAY THROUGH TUESDAY)...WEATHER ON THURSDAY EXPECTED TO BE QUITE NICE WITH A DRY ATMOSPHERIC COLUMN LEADING TO A PLETHORA OF SUNSHINE DURING THE DAY. ANOTHER COLD FRONT WILL SLIP SOUTH INTO THE REGION THURSDAY NIGHT BUT LACK OF ANY SUFFICIENT MOISTURE SHOULD PRECLUDE ANY SIGNIFICANT PRECIP FROM OCCURRING. TIMING DIFFERENCES EXIST BETWEEN GUIDANCE WITH GFS BEING FASTER AND ECMWF/NAM BEING A LITTLE SLOWER. OFFICIAL FORECAST PACKAGE HAS FROPA OCCURRING BETWEEN MIDNIGHT AND SUNRISE WITH A PERIOD OF GUSTY NORTH WINDS POST FROPA. SURFACE HIGH PRESSURE PROG TO QUICKLY BUILD IN AND THEN MOVE TO THE EAST DURING THE DAY FRIDAY WITH SOUTHERLY LLVL FLOW RETURNING BY THE WEEKEND. THIS SHOULD RESULT IN AN INCREASE IN LLVL MOISTURE AND ASSOCIATED CLOUD COVER...WITH THICKEST CLOUD COVER LOCATED ACROSS EASTERN HALF OF CWA. WITH MOISTURE PROG TO BE LIMITED TO ONLY THE LOWER LEVELS...CHANCES OF RAIN WILL REMAIN LOW TO NIL THROUGH THE WEEKEND. A MORE POTENT COLD FRONT MAY APPROACH THE AREA BY LATE IN THE EXTENDED FORECAST. FRIDAY WILL LIKELY BE THE COOLEST DAY OF THE EXTENDED PERIOD WITH HIGHS ONLY IN THE UPPER 60S TO AROUND 70. SSW LLVL WIND PROFILE OVER THE WEEKEND SHOULD HELP WARM DAYTIME TEMPS THROUGH THE 70S WITH SOME LOCATIONS TOUCHING 80 AT TIMES. MIN TEMPS WILL GRADUALLY MODIFY EACH NIGHT FROM THE 30S/40S THURSDAY NIGHT INTO THE 40S/50S OVER THE WEEKEND/EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 42 64 38 73 45 / 0 0 0 0 10 VICTORIA 37 63 35 70 40 / 0 0 0 0 10 LAREDO 42 64 42 74 45 / 0 0 0 0 0 ALICE 41 65 36 74 43 / 0 0 0 0 10 ROCKPORT 42 61 42 67 45 / 0 0 0 0 10 COTULLA 39 63 36 73 38 / 0 0 0 0 0 KINGSVILLE 41 65 35 75 44 / 0 0 0 0 10 NAVY CORPUS 47 62 44 69 48 / 0 0 0 0 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL NOON CST WEDNESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS... BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR. && $$ TE/81...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
531 PM CST TUE JAN 14 2014 .DISCUSSION...SEE 00Z AVIATION DISCUSSION. && .AVIATION...MAIN ISSUE IS TIMING OF FRONT...THEN HOW LONG WINDS STAY UP BEFORE DIMINISHING (AND KEEPING EVERYTHING RELATIVELY SHORT SINCE NO OTHER SIGNIFICANT WEATHER). USING HRRR AND TTU 4 KM MODELS...AM GOING WITH WIND SHIFT ABT 03Z AT KVCT...ABT 04Z AT KRLD AND 05Z AT KCRP/KALI (GIVE OR TAKE 30 MINUTES). AM GOING TO KEEP WINDS UP TIL AT LEAST 12Z...THEN DIMINISH FROM WEST TO EAST DURING THE DAY ON THE 15TH. WITH WINDS UP FOR THE EVENING AND OVERNIGHT PERIOD...WIND SHEAR SHOULD BE NO PROBLEM. OTHERWISE...SKC. && .PREV DISCUSSION... /ISSUED 325 PM CST TUE JAN 14 2014/ SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...COLD FRONT WILL MOVE THROUGH CWA JUST BEFORE MIDNIGHT TONIGHT...BRINGING NORTHERLY WINDS AROUND 15 KT OVER LAND AND 25 KT OFFSHORE. WEDNESDAY AFTERNOON SHOULD SEE A SURFACE HIGH BEHIND THE FRONT SETTLE INTO THE FORECAST AREA. AS THE CENTER OF HIGH PRESSURE TOMORROW WILL BE LOCATED OVER THE RIO GRANDE VALLEY...EXPECTING LIGHT WESTERLY WINDS. BY TOMORROW NIGHT...SURFACE HIGH PRESSURE WILL SHIFT EAST AND MOVE OVER THE WESTERN GOM WHICH WILL ALLOW ONSHORE FLOW TO RESUME AND INCREASE LOW LEVEL MOISTURE. THE LACK OF ANY MOISTURE WILL KEEP POPS TO ZERO AND KEEP SKIES CLEAR THROUGH THE SHORT TERM. CLEAR SKIES TONIGHT SHOULD ALLOW FOR LOWS IN THE LOWER 40S OVER THE SOUTHERN BRUSH COUNTRY AND SOUTHERN COASTAL BEND AND THE UPPER 30S OVER THE NORTHERN COUNTIES. HIGHS TOMORROW BEHIND THE FRONT WILL BE IN THE 60S ACROSS MOST OF THE AREA WITH SOME UPPER 50S OFFSHORE. COOLER AIR BEHIND THE FRONT AND ANOTHER CLEAR AND CALM NIGHT WILL LEAD TO LOWS IN THE MID 30S INLAND AND LOWER 40S NEAR THE COAST...AS WELL AS THE WESTERN BRUSH COUNTRY. MARINE...INCREASING NORTHERLY WINDS BEHIND TONIGHTS FRONT WILL INCREASE OFFSHORE WINDS TO 20-25 KT BETWEEN 6 AND 18Z. ADDITIONALLY...WAVE HEIGHTS AROUND 7 FEET ARE EXPECTED IN THE OFFSHORE ZONES. A SMALL CRAFT ADVISORY WILL BE IN EFFECT FROM 6 TO 12Z OVER THE SOUTHERN BAYS AND WATERWAYS...AND 6 TO 18Z OVER THE OFFSHORE WATERS. TOMORROW AFTERNOON WILL SEE A RETURN TO CALMER CONDITIONS. LONG TERM (THURSDAY THROUGH TUESDAY)...WEATHER ON THURSDAY EXPECTED TO BE QUITE NICE WITH A DRY ATMOSPHERIC COLUMN LEADING TO A PLETHORA OF SUNSHINE DURING THE DAY. ANOTHER COLD FRONT WILL SLIP SOUTH INTO THE REGION THURSDAY NIGHT BUT LACK OF ANY SUFFICIENT MOISTURE SHOULD PRECLUDE ANY SIGNIFICANT PRECIP FROM OCCURRING. TIMING DIFFERENCES EXIST BETWEEN GUIDANCE WITH GFS BEING FASTER AND ECMWF/NAM BEING A LITTLE SLOWER. OFFICIAL FORECAST PACKAGE HAS FROPA OCCURRING BETWEEN MIDNIGHT AND SUNRISE WITH A PERIOD OF GUSTY NORTH WINDS POST FROPA. SURFACE HIGH PRESSURE PROG TO QUICKLY BUILD IN AND THEN MOVE TO THE EAST DURING THE DAY FRIDAY WITH SOUTHERLY LLVL FLOW RETURNING BY THE WEEKEND. THIS SHOULD RESULT IN AN INCREASE IN LLVL MOISTURE AND ASSOCIATED CLOUD COVER...WITH THICKEST CLOUD COVER LOCATED ACROSS EASTERN HALF OF CWA. WITH MOISTURE PROG TO BE LIMITED TO ONLY THE LOWER LEVELS...CHANCES OF RAIN WILL REMAIN LOW TO NIL THROUGH THE WEEKEND. A MORE POTENT COLD FRONT MAY APPROACH THE AREA BY LATE IN THE EXTENDED FORECAST. FRIDAY WILL LIKELY BE THE COOLEST DAY OF THE EXTENDED PERIOD WITH HIGHS ONLY IN THE UPPER 60S TO AROUND 70. SSW LLVL WIND PROFILE OVER THE WEEKEND SHOULD HELP WARM DAYTIME TEMPS THROUGH THE 70S WITH SOME LOCATIONS TOUCHING 80 AT TIMES. MIN TEMPS WILL GRADUALLY MODIFY EACH NIGHT FROM THE 30S/40S THURSDAY NIGHT INTO THE 40S/50S OVER THE WEEKEND/EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 42 64 38 73 45 / 0 0 0 0 10 VICTORIA 37 63 35 70 40 / 0 0 0 0 10 LAREDO 42 64 42 74 45 / 0 0 0 0 0 ALICE 41 65 36 74 43 / 0 0 0 0 10 ROCKPORT 42 61 42 67 45 / 0 0 0 0 10 COTULLA 39 63 36 73 38 / 0 0 0 0 0 KINGSVILLE 41 65 35 75 44 / 0 0 0 0 10 NAVY CORPUS 47 62 44 69 48 / 0 0 0 0 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST WEDNESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS. && $$ GW/86...AVIATION
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
NWS MARQUETTE MI
454 AM EST WED JAN 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 453 AM EST WED JAN 15 2014 THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES. WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL 15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING. FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT. THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW DIMINISHES. OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS. AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER TEENS. 12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15 OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS (20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO THINK THAT IS ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT HOURS...THE SOCIETAL IMPACT WILL BE LIMITED AND THUS WILL ISSUE A AN SPS LATER THIS MORNING WITH INFO FOR THURSDAY INTO FRIDAY TOO. ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 446 PM EST TUE JAN 14 2014 RIDGE WEST...TROUGH EAST. THE PATTERN REMAINS THROUGH THROUGH MUCH OF THE LONG TERM PERIOD. FOR AN OVERVIEW OF WHAT WILL BE HAPPENING ALOFT...THE 500MB LOW OVER N MANITOBA AT 00Z THURSDAY WILL SWEEP INTO CENTRAL ONTARIO AND THE W HALF OF LAKE SUPERIOR BY 12Z THURSDAY. AT THAT POINT THE LOW WILL SLOW DOWN QUITE A BIT...AND REMAIN ACROSS THE UPPER GREAT LAKES THROUGH THE DAY THURSDAY...BEFORE THE LINGERING TROUGH SLOWLY EXITS ACROSS EASTERN ONTARIO AND LAKE HURON FRIDAY AND FRIDAY NIGHT. THIS WILL KEEP NNW FLOW ALOFT ACROSS LAKE SUPERIOR AND UPPER MI FROM FRIDAY AFTERNOON THROUGH SUNDAY MONDAY. AS FOR SPECIFICS...THE SFC LOW NEAR THE S MANITOBA/ONTARIO BORDER JUST PRIOR TO 06Z THURSDAY SHOULD SHIFT SE INTO S CENTRAL LAKE SUPERIOR/AND THE W HALF OF UPPER MI BY 18Z. S-SSW WINDS WILL REMAIN IN THE 10-20KT RANGE WEDNESDAY NIGHT. WARMER AIR WILL BE ABLE TO SWEEP IN FOR THURSDAY...WITH HIGHS IN THE UPPER 20S...THANKS TO THE MID AFTERNOON LOW PASSAGE ALLOWING 850MB TEMPS TO RISE INTO THE -5 TO -7F RANGE. EXPECT THE SFC LOW TO EXIT FAR E UPPER MI THURSDAY NIGHT INTO FRIDAY. GIVEN THE SLOW PROGRESS OF THE LOW...LOOK FOR A SIGNIFICANT BREAK BETWEEN THE STRONG W-SSW WINDS WEDNESDAY NIGHT AND COLDER AIR RUSHING IN THE N-NNW WINDS THURSDAY NIGHT INTO FRIDAY. HIGH FRIDAY SHOULD BE ON THE ORDER OF 15F COOLER OVER W AND CENTRAL UPPER MI...WHILE ONLY A COULD DEGREES COOLER E. ALTHOUGH FAR W LAKE SUPERIOR MAY BE PRETTY FROZEN...THERE IS LIKELY PLENTY OF RELATIVELY WARM OPEN WATER STILL AVAILABLE N OF THE APOSTLE ISLANDS TO ALLOW THE MAINLY N FLOW OF COLD AIR TO PRODUCE MODERATE LES FROM LATE THURSDAY AFTERNOON THROUGH THE DAY FRIDAY. THE FLOW BECOMES MORE W-NW OVER W LAKE SUPERIOR FRIDAY EVENING AS WAA TAKES HOLD AND 850MB TEMPS THAT WERE ON THE ORDER OF -14 TO -17C QUICKLY JUMP UP TO AROUND -10C. LES WILL CONTINUE TO PERSIST NEAR AND E OF MUNISING INTO SATURDAY. THERE IS STILL A QUESTION AS TO HOW LONG THE FETCH REMAINS FAVORABLE FOR THIS AREA...AS THE 12Z ECMWF IS GOING WITH A MORE W FLOW NEAR THE SFC...WHICH WOULD KEEP THE BEST CHANCE OF LES ONLY RIGHT ALONG THE SHORELINE E SATURDAY...IF NOT OFF SHORE. A SIZABLE RIDGE EXTENDING UP FROM THE 4-CORNERS REGION THROUGH THE DAKOTAS AND SOUTH CENTRAL CANADA SUNDAY MORNING WILL BRIEFLY MOVE ACROSS THE UPPER GREAT LAKES SUNDAY AFTERNOON INTO SUNDAY EVENING. WHILE THE 12Z RUN OF THE GFS IS LESS THAN IMPRESSIVE WITH THE RIDGE...THE 00Z RUNS OF THE ECMWF AND TO A GREATER EXTENT THE CANADIAN MODEL. OTHERWISE PAST SUNDAY EVENING WE GET BACK INTO THE PERSISTENT NW FLOW AGAIN ALOFT...THANKS TO THE MAIN 500MB LOW SLIDING FROM N CENTRAL CANADA FRIDAY NIGHT...ACROSS JAMES BAY SATURDAY NIGHT...AND INTO QUEBEC SUNDAY/SUNDAY NIGHT. WHILE THE MAIN LOW RETREATS BACK N...A MODERATED PIECE OF THE COLDER AIR WILL BE ABLE TO DIVE IN MONDAY NIGHT THROUGH MUCH OF THE UPCOMING WORK WEEK /AT LEAST ACCORDING TO THE 12Z ECMWF/. GIVEN THE PERSISTENT N-NNW FLOW...HAVE INCREASED POPS FOR MONDAY NIGHT THROUGH TUESDAY ALONG LAKE SUPERIOR TO LIKELY AND DEFINITE CATEGORIES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1151 PM EST TUE JAN 14 2014 LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON. NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT SNOW BREAKING OUT IN THE EVENING AT ALL SITES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 453 AM EST WED JAN 15 2014 A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35 KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD. SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST GALES TO 35KTS. HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT. WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ006. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ248>251-265>267. GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR LSZ266-267. HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162- 263-264. HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ244-245-263-264. GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR LSZ263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...KF AVIATION...07 MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1155 PM EST TUE JAN 14 2014 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 359 PM EST TUE JAN 14 2014 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH FROM HUDSON BAY INTO THE CNTRL CONUS. A POTENT SHORTWAVE TROUGH LOCATED OVER SRN WI WAS MOVING TOWARD SRN LOWER MI. AT THE SFC CIRCULATION AROUND A 999 MB LOW PRES OVER E CNTRL WI RESULTED IN STRONG NE WINDS INTO SRN UPPER MI. INCREASING NRLY WINDS ACROSS LAKE SUPERIOR ALONG WITH 850 MB TEMPS IN THE -13C TO -16C RANGE SUPPORTED LIGHT LES FOR LOCATIONS FAVORED BY NNE WINDS. STRONG 700-500 MB QVECTOR CONV AND FGEN (FN/FS CONV) NEAR THE SHRTWV PIVOT POINT HAS PRODUCED HEAVY SNOWFALL RATES OF AN INCH OR TWO PER HOUR OVER FAR SRN UPPER (MNM) MI WHERE 7 INCHES HAD FALLEN BY 20Z. THIS ALSO ALIGNED WELL WITH THE SRN EXTENT OF THE COLDER CLOUD TOPS...PER IR LOOP. LATE THIS AFTERNOON AND TONIGHT...SATELLITE/RADAR TRENDS AND SHORT RANGE MODELS SUGGEST THAT THE COMMA HEAD PORTION OF THE SHRTWV WILL MOVE INTO LAKE MI THIS EVENING BTWN 00Z-03Z AND DRAG THE BACK END OF THE SNOW OUT OF THE SRN CWA. UNTIL THEN...MODERATE TO HEAVY SNOW WILL CONTINUE OVER THE SOUTH ALONG WITH NE WINDS GUSTING TO AROUND 30 MPH. EXPECT THE LES IN CONVERGENT NRLY FLOW INTO WRN ALGER COUNTY TO INCREASE AS THE DEEPER MOISTURE WITH THE SYNOPTIC SYSTEM EDGES SLOWLY NORTHWARD. ALTHOUGH THE DEEPER MOISTURE WILL DEPART AFT 06Z...INSTABILITY WILL INCREASE AS CAA DROPS 850 MB TEMPS TO AROUND -17C. MODERATE SNOWFALL AMOUNTS IN THE 3 TO 5 INCH RANGE ARE EXPECTED MAINLY NEAR AU TRAIN/EBEN/CHATHAM...PER CONSENSUS OF HIGHER RES MODELS. OVER THE WEST...INVERSION HEIGHTS AROUND 3K FT SHOULD LIMIT SNOW AMOUNTS TO LESS THAN AN INCH. WED....MID/UPPER LEVEL RIDGING WILL DEVELOP OVER THE NRN LAKES AHEAD OF THE NEXT SHRTWV DIVING TOWARD SRN MANITOBA AND NRN MN. AT THE SURFACE...A RIDGE FROM MN INTO NW ONTARIO WILL BUILD TOWARD THE SRN GREAT LAKES AS A DEEP CLIPPER LOW MOVES TO NEAR LAKE WINNIPEG. THIS WILL LEAD TO NORTH-NORTHWEST WINDS ACROSS LAKE SUPERIOR AND WITH 850MB TEMPS AROUND -16C THERE WILL BE ENOUGH LAKE INSTABILITY AND LOW LEVEL MOISTURE FOR LINGERING LAKE EFFECT. BUT WITH THE SURFACE RIDGE QUICKLY SLIDING THROUGH THE UPPER GREAT LAKES...EXPECT WINDS TO QUICKLY BACK THROUGH THE DAY. THE BACKING WINDS...ALONG WITH DRIER LOW LEVEL AIR WILL BRING AN END TO THE LAKE EFFECT OVER THE WEST AROUND EARLY AFTERNOON AND THEN OVER THE EAST BY LATE AFTERNOON. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 446 PM EST TUE JAN 14 2014 RIDGE WEST...TROUGH EAST. THE PATTERN REMAINS THROUGH THROUGH MUCH OF THE LONG TERM PERIOD. FOR AN OVERVIEW OF WHAT WILL BE HAPPENING ALOFT...THE 500MB LOW OVER N MANITOBA AT 00Z THURSDAY WILL SWEEP INTO CENTRAL ONTARIO AND THE W HALF OF LAKE SUPERIOR BY 12Z THURSDAY. AT THAT POINT THE LOW WILL SLOW DOWN QUITE A BIT...AND REMAIN ACROSS THE UPPER GREAT LAKES THROUGH THE DAY THURSDAY...BEFORE THE LINGERING TROUGH SLOWLY EXITS ACROSS EASTERN ONTARIO AND LAKE HURON FRIDAY AND FRIDAY NIGHT. THIS WILL KEEP NNW FLOW ALOFT ACROSS LAKE SUPERIOR AND UPPER MI FROM FRIDAY AFTERNOON THROUGH SUNDAY MONDAY. AS FOR SPECIFICS...THE SFC LOW NEAR THE S MANITOBA/ONTARIO BORDER JUST PRIOR TO 06Z THURSDAY SHOULD SHIFT SE INTO S CENTRAL LAKE SUPERIOR/AND THE W HALF OF UPPER MI BY 18Z. S-SSW WINDS WILL REMAIN IN THE 10-20KT RANGE WEDNESDAY NIGHT. WARMER AIR WILL BE ABLE TO SWEEP IN FOR THURSDAY...WITH HIGHS IN THE UPPER 20S...THANKS TO THE MID AFTERNOON LOW PASSAGE ALLOWING 850MB TEMPS TO RISE INTO THE -5 TO -7F RANGE. EXPECT THE SFC LOW TO EXIT FAR E UPPER MI THURSDAY NIGHT INTO FRIDAY. GIVEN THE SLOW PROGRESS OF THE LOW...LOOK FOR A SIGNIFICANT BREAK BETWEEN THE STRONG W-SSW WINDS WEDNESDAY NIGHT AND COLDER AIR RUSHING IN THE N-NNW WINDS THURSDAY NIGHT INTO FRIDAY. HIGH FRIDAY SHOULD BE ON THE ORDER OF 15F COOLER OVER W AND CENTRAL UPPER MI...WHILE ONLY A COULD DEGREES COOLER E. ALTHOUGH FAR W LAKE SUPERIOR MAY BE PRETTY FROZEN...THERE IS LIKELY PLENTY OF RELATIVELY WARM OPEN WATER STILL AVAILABLE N OF THE APOSTLE ISLANDS TO ALLOW THE MAINLY N FLOW OF COLD AIR TO PRODUCE MODERATE LES FROM LATE THURSDAY AFTERNOON THROUGH THE DAY FRIDAY. THE FLOW BECOMES MORE W-NW OVER W LAKE SUPERIOR FRIDAY EVENING AS WAA TAKES HOLD AND 850MB TEMPS THAT WERE ON THE ORDER OF -14 TO -17C QUICKLY JUMP UP TO AROUND -10C. LES WILL CONTINUE TO PERSIST NEAR AND E OF MUNISING INTO SATURDAY. THERE IS STILL A QUESTION AS TO HOW LONG THE FETCH REMAINS FAVORABLE FOR THIS AREA...AS THE 12Z ECMWF IS GOING WITH A MORE W FLOW NEAR THE SFC...WHICH WOULD KEEP THE BEST CHANCE OF LES ONLY RIGHT ALONG THE SHORELINE E SATURDAY...IF NOT OFF SHORE. A SIZABLE RIDGE EXTENDING UP FROM THE 4-CORNERS REGION THROUGH THE DAKOTAS AND SOUTH CENTRAL CANADA SUNDAY MORNING WILL BRIEFLY MOVE ACROSS THE UPPER GREAT LAKES SUNDAY AFTERNOON INTO SUNDAY EVENING. WHILE THE 12Z RUN OF THE GFS IS LESS THAN IMPRESSIVE WITH THE RIDGE...THE 00Z RUNS OF THE ECMWF AND TO A GREATER EXTENT THE CANADIAN MODEL. OTHERWISE PAST SUNDAY EVENING WE GET BACK INTO THE PERSISTENT NW FLOW AGAIN ALOFT...THANKS TO THE MAIN 500MB LOW SLIDING FROM N CENTRAL CANADA FRIDAY NIGHT...ACROSS JAMES BAY SATURDAY NIGHT...AND INTO QUEBEC SUNDAY/SUNDAY NIGHT. WHILE THE MAIN LOW RETREATS BACK N...A MODERATED PIECE OF THE COLDER AIR WILL BE ABLE TO DIVE IN MONDAY NIGHT THROUGH MUCH OF THE UPCOMING WORK WEEK /AT LEAST ACCORDING TO THE 12Z ECMWF/. GIVEN THE PERSISTENT N-NNW FLOW...HAVE INCREASED POPS FOR MONDAY NIGHT THROUGH TUESDAY ALONG LAKE SUPERIOR TO LIKELY AND DEFINITE CATEGORIES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1151 PM EST TUE JAN 14 2014 LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON. NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT SNOW BREAKING OUT IN THE EVENING AT ALL SITES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 359 PM EST TUE JAN 14 2014 NORTH WINDS OF 30 KNOTS OVER ERN LAKE SUPERIOR TONIGHT AS A SFC LOW PASSES SOUTH AND EAST OF REGION WILL PRODUCE HEAVY FREEZING SPRAY. EXPECT THE WINDS TO DIMINISH BRIEFLY ON WEDNESDAY AS A HIGH PRESSURE RIDGE CROSSES THE REGION. LOW PRESSURE CROSSING LAKE WINNIPEG LATE WEDNESDAY AFTERNOON WILL THEN SINK ACROSS LAKE SUPERIOR ON THURSDAY. SW GALES OF 35 KTS ARE POSSIBLE WEDNESDAY NIGHT OVER EASTERN SECTIONS. N-NW GALES OF 35 KTS ARE ALSO POSSIBLE LATE THURSDAY AFTERNOON THROUGH FRIDAY MORNING IN WAKE OF A COLD FRONT FOLLOWING THE LOW. THE LOW WILL WEAKEN AS IT DRIFTS EASTWARD INTO SOUTHERN ONTARIO THROUGH THE DAY FRIDAY...WHILE KEEPING A WEAK TROUGH OVER LAKE SUPERIOR. HEAVY FREEZING SPRAY WILL BE POSSIBLE THURSDAY NIGHT THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ006. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST WEDNESDAY FOR LSZ248>251-265>267. HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ244- 245-263-264. LAKE MICHIGAN... GALE WARNING UNTIL 9 AM EST WEDNESDAY FOR LMZ250. && $$ SHORT TERM...JLB LONG TERM...KF AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
321 AM EST WED JAN 14 2014 .SYNOPSIS...WEAK HIGH PRESSURE WILL RIDGE ACROSS THE SOUTHEAST THIS MORNING...THEN GIVE WAY TO AN APPALACHIAN LEE SURFACE TROUGH THIS AFTERNOON. AN ARCTIC COLD FRONT AND ACCOMPANYING STRONG UPPER LEVEL TROUGH WILL THEN CROSS THE MIDDLE ATLANTIC REGION AND INDUCE COASTAL LOW PRESSURE DEVELOPMENT THIS EVENING AND OVERNIGHT...FOLLOWED BY BRIEF HIGH PRESSURE ON THU. && .NEAR TERM /TONIGHT AND WEDNESDAY/... AS OF 900 PM TUESDAY... TONIGHT: MAIN FORECAST CHALLENGE FOR TONIGHT IS THE EXTENT/DURATION OF FOG. CLEAR SKIES AND WEAK SFC RIDGING EXTENDING INTO THE AREA FROM THE SW HAS PROMOTED CALM SFC WINDS. SOME PATCHY DENSE FOG... HAS ALREADY DEVELOPED ACROSS COASTAL COUNTIES WHERE LOW-LEVELS REMAIN QUIET MOIST...PER 00Z/15 MHX RAOB...WITH ONLY MINOR/WEAK ADVECTION OF DRY AIR FROM THE WEST COMPARED TO WESTERN PORTIONS OF THE STATE(PER LATEST GSO RAOB). MUCH OF THE MODEL GUIDANCE INDICATES DEWPOINTS WILL FALL OVERNIGHT...WHICH WOULD INHIBIT FOG...PARTICULARLY DENSE FOG. HOWEVER THE LATEST RAP GUIDANCE KEEPS DEWPOINTS PRETTY MUCH STATUS QUO OVERNIGHT WITH NO DRIER AIR WORKING IN FROM THE WEST WHICH IS VERY PLAUSIBLE GIVEN WEAK SFC WINDS. WILL CONTINUE TO MONITOR THESE TRENDS...AND IF THE DRIER DOES NOT DOES NOT BUILD EAST...A DENSE FOG ADVISORY MAY NEED TO BE ISSUED FOR CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA. LOWS RANGING FROM LOWER TO MID 30 NW TO UPPER 30S TO AROUND 40 SE. FOR THE DAY WEDNESDAY...THE SURFACE FRONT GRADUALLY MOVES EAST INTO CENTRAL NORTH CAROLINA...THEN SLOWS AS THE UPPER TROUGH SHARPENS... AND THE SOUTHWEST JET AT 300MB INCREASES TO 135KT LATE IN THE DAY OVER CENTRAL NORTH CAROLINA HELPING TO PROVIDE FOR SLOWLY DEEPENING LOW PRESSURE OFF THE COAST. THE RIGHT ENTRANCE REGION OF A 90KT 500MB JET MOVES NEAR OR INTO THE NORTHWEST PIEDMONT LATE IN THE DAY. MOISTURE IS NOT GREAT...WITH K INDICES ONLY ON THE GFS BARELY BEYOND SINGLE FIGURES AND WITH AN 850MB THETA-E RIDGE THAT IS CERTAINLY WEAK COMPARED TO RECENT PRECIPITATION EVENTS. HOWEVER...LIFT DOES INCREASE LATE WITH THE APPROACH OF THE MID-LEVEL JET. QPF FROM THE NAM...GFS...AND ECMWF IS LIMITED WITH ONLY LIGHT...NEAR HUNDREDTH VALUES...MOSTLY WEST OF U.S. 1 VERY LATE IN THE DAY IF THERE IS ANY AT ALL. NAM AND GFS BUFR SOUNDINGS SUGGEST ENOUGH OF A COMBINATION OF MID- AND LOW-LEVEL MOISTURE THAT SOME LIGHT PRECIPITATION COULD BEGIN REACHING THE GROUND AFTER 21Z IN THOSE AREAS...BETTER CHANCE IN A RELATIVE SENSE TOWARD THE IMMEDIATE TRIAD. AS THE GRADIENT TIGHTENS LATE IN THE DAY OVER THE WESTERN PART OF THE STATE...AN INCREASING NORTHERLY SURFACE FLOW...COUPLED WITH ANY SPOTTY PRECIPITATION...COULD RESULT IN RAPIDLY COOLING TEMPERATURES LATE IN THE DAY IN THE TRIAD. BEFORE THEN...1000-850MB THICKNESSES SUPPORT HIGHS CLOSE TO THE MOS GUIDANCE CONSENSUS...IN THE LOWER 50S NORTHWEST TO AROUND 60 SOUTHEAST UNDER A PARTLY SUNNY SKY ON AVERAGE FOR THE ENTIRE DAY. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 250 PM TUESDAY... MULTIPLE SHORTWAVE TROUGHS WILL DIVE INTO THE SOUTHEASTERN U.S. DURING THE SHORT-TERM PERIOD CULMINATING IN A STRONG NEGATIVELY TILTED TROUGH THAT WIL SWING THROUGH THE CAROLINAS ON THURSDAY MORNING. MEANWHILE AN ARCTIC COLD FRONT WILL MOVE EAST ACROSS CENTRAL NC DURING THE LATE AFTERNOON WEDNESDAY AND WEDNESDAY NIGHT. AS THE IMPRESSIVE MID LEVEL WAVE WITH STRONG HEIGHT FALLS AND A 100+KT JET AT 500 HPA APPROACHES THE ARCTIC COLD FRONT AND THE STALLED FRONT NEAR THE GULF STREAM...CYCLOGENESIS WILL COMMENCE LATE WEDNESDAY NIGHT OFFSHORE OF CAPE FEAR. FORECAST CONFIDENCE REMAINS BELOW AVERAGE FOR THIS PERIOD AS GUIDANCE HAS BEEN EVOLVING IN THE HANDLING OF THE ARCTIC COLD FRONT AND THE RESULTANT CYCLOGENESIS. IT SHOULD BE NOTED THAT GUIDANCE IS TRENDING SLOWER WITH A MORE AMPLIFIED UPPER AIR PATTERN AND A STRONGER SURFACE SYSTEM ALBEIT WITH VARYING QPF SCENARIOS. THE MOST LIKELY SCENARIO AT THIS POINT IS FOR AN AREA OF MAINLY LIGHT PRECIPITATION TO SPREAD EAST OUT OF THE NC FOOTHILLS LATE WEDNESDAY AFTERNOON AND MOVE INTO THE WESTERN PIEDMONT TOWARD SUNSET. WHILE THE PRECIPITATION WILL FALL BEHIND THE ARCTIC FRONT...THE NEAR SURFACE TEMPERATURES WIL BE SUFFICIENTLY WARM AND DEEP TO RESULT IN A RAIN PTYPE THROUGH AT LEAST INTO EARLY EVENING. THE SURGE OF COLD AIR EASTWARD DURING THE LATE EVENING AND OVERNIGHT SHOULD DRIVE A CHANGEOVER TO SNOW FROM WEST TO EAST OVERNIGHT. PRECIPITATION AMOUNTS ARE EXPECTED TO BE LIGHT AND LESS THAN IF NOT MUCH LESS THAN A TENTH OF AN INCH....MAINLY WEST OF U.S. ROUTE 1 WITH LITTLE IF ANY PRECIPITATION EAST ACROSS THE COASTAL PLAIN. THIS COULD RESULT IN A LIGHT COATING OF SNOW BY THURSDAY MORNING IN THE NORTHERN AND NORTHWEST PIEDMONT BUT THIS IS LIKELY A MORE EXTREME SCENARIO WITH MOST LOCATIONS ONLY OBSERVING A PERIOD OF LIGHT LIGHT SNOW FOR A FEW HOURS WITH NO ACCUMULATION. TEMPERATURES BY THURSDAY MORNING WILL FALL TO OR BELOW FREEZING ACROSS ALL OF THE RAH CWA WITH MINIMUMS RANGING FROM 25 IN THE NORTHWEST PIEDMONT TO AROUND 30 IN THE COASTAL PLAIN. GUIDANCE CONTINUES TO TREND SLOWER WITH LIGHT PRECIPITATION NOW PERSISTING INTO THURSDAY MORNING AS IT GRADUALLY SHIFTS EAST. QPF AMOUNTS AGAIN ARE EXPECTED TO BE LIGHT AND LESS THAN A TENTH OF AN INCH. INITIALLY THE PREDOMINANT P-TYPE WILL LIKELY BE SNOW THURSDAY MORNING WITH SURFACE TEMPERATURES CONFINED TO THE 30S DURING THE MORNING BUT NAM/GFS BUFR SOUNDINGS SUGGEST THAT THE MOISTURE MAY NOT BE SUFFICIENTLY DEEP TO EXTEND IN THE ICE NUCLEATION REGION AND ABOVE FREEZIN TEMPS WILL PROBABLY RESULT IN MORE OF A RIAN.SBNOW MIX. REGARDLESS THE LIGHT NATURE OF THE PRECIPITATION SHOULD PRECLUDE ANY APPRECIABLE ACCUMULATION DURING THE DAY THURSDAY. WE WILL NEED TO MONITOR THE INTENSITY AND TRACK OF THE DEVELOPING SURFACE LOW AS ONLY A SMALL WESTWARD SHIFT WOULD POTENTIALLY RESULT IN NOTICEABLY MORE PRECIPITATION IN LOCATIONS EAST OF U.S. 1 ON THURSDAY. ALL OF THE PRECIPITATION SHOULD END BY EARLY AFTERNOON WITH HIGHS EVENTUALLY REACHING THE 40-45 RANGE BY LATE IN THE DAY. DRY WEATHER WITH CLEARING SKIES ARE EXPECTED ON THURSDAY NIGHT. LOWS SHOULD FALL INTO THE 26-32 RANGE BY FRIDAY MORNING. -BLAES && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 258 AM WEDNESDAY... COLD FRONT WILL CROSS THE AREA LATE FRIDAY/EARLY SATURDAY. THERE IS A CHANCE FOR LIGHT PRECIPITATION... RAIN POTENTIALLY CHANGING TO/MIXING WITH A PERIOD OF LIGHT SNOW... AS THE UPPER LEVEL SHORTWAVE AXIS CROSSES THE AREA. STRONG COLD ADVECTION WILL IMMEDIATELY FOLLOW THE FRONTAL PASSAGE... KEEPING HIGHS IN THE UPPER 30S TO LOW 40S. SATURDAY. A CLIPPER SYSTEM MOVES ACROSS THE AREA FROM THE NORTHWEST EARLY SUNDAY... WITH LITTLE MOISTURE AND WESTERLY FLOW... PRECIP LOOKS UNLIKELY. HIGHS IN THE MID 40S. FLOW BECOMES SOUTHWESTERLY ON MONDAY... WITH THICKNESSES REBOUNDING... HIGHS IN THE 50S... AND NEAR NORMAL TEMPERAUTRES CONTINUE INTO TUESDAY. NORTHERN STREAM WAVE DIGS SOUTHWARD AT THE END OF THE PERIOD... DEPENDING ON THE DEGREE OF PHASING WITH A WEAK SOUTHERN STREAM WAVE... MAY BRING ANOTHER CHANCE AT PRECIPITATION. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 130 AM WEDNESDAY... THE LOW LEVEL FLOW HAS ALREADY BACKED TO SSW IN THE LEE OF THE APPALACHIANS/OVER THE CAROLINAS...AND AS SUCH...THE LOW LEVEL MOISTURE OVER THE CENTRAL AND EASTERN CAROLINAS- AND ASSOCIATED VLIFR VISIBILITY RESTRICTIONS AND CEILINGS - SHOULD ONLY GET WORSE AND EXPAND NORTHWESTWARD THROUGHOUT THE MORNING. IN OTHER WORDS...THERE IS NO DRY AIR COMING OUR WAY TO DISPERSE THE LOW CLOUDS AND FOG THIS MORNING. THE LOW LEVEL MOISTURE IS CONSEQUENTLY APT TO STICK AROUND FOR THE BETTER PART OF THE MORNING TO MIDDAY HOURS...BEFORE MIXING/SCATTERING THROUGH MVFR BETWEEN 14-16Z...AND TO VFR THEREAFTER. ATTENTION WILL THEN TURN TO A SHARPENING UPPER LEVEL TROUGH TO OUR WEST...AND AN ACCOMPANYING ARCTIC COLD FRONT THAT WILL CROSS CENTRAL NC THIS EVENING AND TONIGHT. SCATTERED RAIN SHOWERS WILL BE POSSIBLE IN THE VICINITY OF THE FRONT LATE THIS AFTERNOON AT TRIAD TERMINALS AND THIS EVENING ELSEWHERE...FOLLOWED BY A LARGER BAND OF LIGHT PRECIPITATION THAT WILL OVERSPREADS OUR REGION OVERNIGHT. WITH COLD AIR RUSHING IN BEHIND THE ARCTIC FRONT...THAT BAND OF LIGHT PRECIPITATION WILL FALL AS LIGHT SNOW...AFTER INITIALLY A RAIN/SNOW MIX AT THE ONSET. MVFR CEILINGS AND MVFR-IFR VISIBILITY RESTRICTIONS WILL ACCOMPANY THE LIGHT SNOW BAND. IN ADDITION...NORTHWEST WINDS WILL INCREASE INTO THE 12-15 KT RANGE WITH GUSTS OF 20-25 KTS AS THE DENSE COLD AIR RUSHES IN BEHIND THE FRONT. OUTLOOK: SUB-VFR CONDITIONS AT LIGHT SNOW WILL END FROM WEST TO EAST BETWEEN 09-15Z THU...FOLLOWED BY CLEAR VFR CONDITIONS FOR THE REST OF THU. ANOTHER FRONTAL SYSTEM WILL BRING A CHANCE OF RAIN CHANGING TO SNOW...AND ASSOCIATED SUB-VFR CONDITIONS...LATE FRI-FRI NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MWS NEAR TERM...CBL/DJF SHORT TERM...BLAES LONG TERM...SEC AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
134 AM EST WED JAN 14 2014 .SYNOPSIS...WEAK HIGH PRESSURE WILL RIDGE ACROSS THE SOUTHEAST THIS MORNING...THEN GIVE WAY TO AN APPALACHIAN LEE SURFACE TROUGH THIS AFTERNOON. AN ARCTIC COLD FRONT AND ACCOMPANYING STRONG UPPER LEVEL TROUGH WILL THEN CROSS THE MIDDLE ATLANTIC REGION AND INDUCE COASTAL LOW PRESSURE DEVELOPMENT THIS EVENING AND OVERNIGHT...FOLLOWED BY BRIEF HIGH PRESSURE ON THU. && .NEAR TERM /TONIGHT AND WEDNESDAY/... AS OF 900 PM TUESDAY... TONIGHT: MAIN FORECAST CHALLENGE FOR TONIGHT IS THE EXTENT/DURATION OF FOG. CLEAR SKIES AND WEAK SFC RIDGING EXTENDING INTO THE AREA FROM THE SW HAS PROMOTED CALM SFC WINDS. SOME PATCHY DENSE FOG... HAS ALREADY DEVELOPED ACROSS COASTAL COUNTIES WHERE LOW-LEVELS REMAIN QUIET MOIST...PER 00Z/15 MHX RAOB...WITH ONLY MINOR/WEAK ADVECTION OF DRY AIR FROM THE WEST COMPARED TO WESTERN PORTIONS OF THE STATE(PER LATEST GSO RAOB). MUCH OF THE MODEL GUIDANCE INDICATES DEWPOINTS WILL FALL OVERNIGHT...WHICH WOULD INHIBIT FOG...PARTICULARLY DENSE FOG. HOWEVER THE LATEST RAP GUIDANCE KEEPS DEWPOINTS PRETTY MUCH STATUS QUO OVERNIGHT WITH NO DRIER AIR WORKING IN FROM THE WEST WHICH IS VERY PLAUSIBLE GIVEN WEAK SFC WINDS. WILL CONTINUE TO MONITOR THESE TRENDS...AND IF THE DRIER DOES NOT DOES NOT BUILD EAST...A DENSE FOG ADVISORY MAY NEED TO BE ISSUED FOR CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA. LOWS RANGING FROM LOWER TO MID 30 NW TO UPPER 30S TO AROUND 40 SE. FOR THE DAY WEDNESDAY...THE SURFACE FRONT GRADUALLY MOVES EAST INTO CENTRAL NORTH CAROLINA...THEN SLOWS AS THE UPPER TROUGH SHARPENS... AND THE SOUTHWEST JET AT 300MB INCREASES TO 135KT LATE IN THE DAY OVER CENTRAL NORTH CAROLINA HELPING TO PROVIDE FOR SLOWLY DEEPENING LOW PRESSURE OFF THE COAST. THE RIGHT ENTRANCE REGION OF A 90KT 500MB JET MOVES NEAR OR INTO THE NORTHWEST PIEDMONT LATE IN THE DAY. MOISTURE IS NOT GREAT...WITH K INDICES ONLY ON THE GFS BARELY BEYOND SINGLE FIGURES AND WITH AN 850MB THETA-E RIDGE THAT IS CERTAINLY WEAK COMPARED TO RECENT PRECIPITATION EVENTS. HOWEVER...LIFT DOES INCREASE LATE WITH THE APPROACH OF THE MID-LEVEL JET. QPF FROM THE NAM...GFS...AND ECMWF IS LIMITED WITH ONLY LIGHT...NEAR HUNDREDTH VALUES...MOSTLY WEST OF U.S. 1 VERY LATE IN THE DAY IF THERE IS ANY AT ALL. NAM AND GFS BUFR SOUNDINGS SUGGEST ENOUGH OF A COMBINATION OF MID- AND LOW-LEVEL MOISTURE THAT SOME LIGHT PRECIPITATION COULD BEGIN REACHING THE GROUND AFTER 21Z IN THOSE AREAS...BETTER CHANCE IN A RELATIVE SENSE TOWARD THE IMMEDIATE TRIAD. AS THE GRADIENT TIGHTENS LATE IN THE DAY OVER THE WESTERN PART OF THE STATE...AN INCREASING NORTHERLY SURFACE FLOW...COUPLED WITH ANY SPOTTY PRECIPITATION...COULD RESULT IN RAPIDLY COOLING TEMPERATURES LATE IN THE DAY IN THE TRIAD. BEFORE THEN...1000-850MB THICKNESSES SUPPORT HIGHS CLOSE TO THE MOS GUIDANCE CONSENSUS...IN THE LOWER 50S NORTHWEST TO AROUND 60 SOUTHEAST UNDER A PARTLY SUNNY SKY ON AVERAGE FOR THE ENTIRE DAY. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 250 PM TUESDAY... MULTIPLE SHORTWAVE TROUGHS WILL DIVE INTO THE SOUTHEASTERN U.S. DURING THE SHORT-TERM PERIOD CULMINATING IN A STRONG NEGATIVELY TILTED TROUGH THAT WIL SWING THROUGH THE CAROLINAS ON THURSDAY MORNING. MEANWHILE AN ARCTIC COLD FRONT WILL MOVE EAST ACROSS CENTRAL NC DURING THE LATE AFTERNOON WEDNESDAY AND WEDNESDAY NIGHT. AS THE IMPRESSIVE MID LEVEL WAVE WITH STRONG HEIGHT FALLS AND A 100+KT JET AT 500 HPA APPROACHES THE ARCTIC COLD FRONT AND THE STALLED FRONT NEAR THE GULF STREAM...CYCLOGENESIS WILL COMMENCE LATE WEDNESDAY NIGHT OFFSHORE OF CAPE FEAR. FORECAST CONFIDENCE REMAINS BELOW AVERAGE FOR THIS PERIOD AS GUIDANCE HAS BEEN EVOLVING IN THE HANDLING OF THE ARCTIC COLD FRONT AND THE RESULTANT CYCLOGENESIS. IT SHOULD BE NOTED THAT GUIDANCE IS TRENDING SLOWER WITH A MORE AMPLIFIED UPPER AIR PATTERN AND A STRONGER SURFACE SYSTEM ALBEIT WITH VARYING QPF SCENARIOS. THE MOST LIKELY SCENARIO AT THIS POINT IS FOR AN AREA OF MAINLY LIGHT PRECIPITATION TO SPREAD EAST OUT OF THE NC FOOTHILLS LATE WEDNESDAY AFTERNOON AND MOVE INTO THE WESTERN PIEDMONT TOWARD SUNSET. WHILE THE PRECIPITATION WILL FALL BEHIND THE ARCTIC FRONT...THE NEAR SURFACE TEMPERATURES WIL BE SUFFICIENTLY WARM AND DEEP TO RESULT IN A RAIN PTYPE THROUGH AT LEAST INTO EARLY EVENING. THE SURGE OF COLD AIR EASTWARD DURING THE LATE EVENING AND OVERNIGHT SHOULD DRIVE A CHANGEOVER TO SNOW FROM WEST TO EAST OVERNIGHT. PRECIPITATION AMOUNTS ARE EXPECTED TO BE LIGHT AND LESS THAN IF NOT MUCH LESS THAN A TENTH OF AN INCH....MAINLY WEST OF U.S. ROUTE 1 WITH LITTLE IF ANY PRECIPITATION EAST ACROSS THE COASTAL PLAIN. THIS COULD RESULT IN A LIGHT COATING OF SNOW BY THURSDAY MORNING IN THE NORTHERN AND NORTHWEST PIEDMONT BUT THIS IS LIKELY A MORE EXTREME SCENARIO WITH MOST LOCATIONS ONLY OBSERVING A PERIOD OF LIGHT LIGHT SNOW FOR A FEW HOURS WITH NO ACCUMULATION. TEMPERATURES BY THURSDAY MORNING WILL FALL TO OR BELOW FREEZING ACROSS ALL OF THE RAH CWA WITH MINIMUMS RANGING FROM 25 IN THE NORTHWEST PIEDMONT TO AROUND 30 IN THE COASTAL PLAIN. GUIDANCE CONTINUES TO TREND SLOWER WITH LIGHT PRECIPITATION NOW PERSISTING INTO THURSDAY MORNING AS IT GRADUALLY SHIFTS EAST. QPF AMOUNTS AGAIN ARE EXPECTED TO BE LIGHT AND LESS THAN A TENTH OF AN INCH. INITIALLY THE PREDOMINANT P-TYPE WILL LIKELY BE SNOW THURSDAY MORNING WITH SURFACE TEMPERATURES CONFINED TO THE 30S DURING THE MORNING BUT NAM/GFS BUFR SOUNDINGS SUGGEST THAT THE MOISTURE MAY NOT BE SUFFICIENTLY DEEP TO EXTEND IN THE ICE NUCLEATION REGION AND ABOVE FREEZIN TEMPS WILL PROBABLY RESULT IN MORE OF A RIAN.SBNOW MIX. REGARDLESS THE LIGHT NATURE OF THE PRECIPITATION SHOULD PRECLUDE ANY APPRECIABLE ACCUMULATION DURING THE DAY THURSDAY. WE WILL NEED TO MONITOR THE INTENSITY AND TRACK OF THE DEVELOPING SURFACE LOW AS ONLY A SMALL WESTWARD SHIFT WOULD POTENTIALLY RESULT IN NOTICEABLY MORE PRECIPITATION IN LOCATIONS EAST OF U.S. 1 ON THURSDAY. ALL OF THE PRECIPITATION SHOULD END BY EARLY AFTERNOON WITH HIGHS EVENTUALLY REACHING THE 40-45 RANGE BY LATE IN THE DAY. DRY WEATHER WITH CLEARING SKIES ARE EXPECTED ON THURSDAY NIGHT. LOWS SHOULD FALL INTO THE 26-32 RANGE BY FRIDAY MORNING. -BLAES && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 315 PM TUESDAY... THE LONG TERM PERIOD FEATURES A PROGRESSIVE PATTERN WITH SYSTEMS DROPPING INTO THE MID ATLANTIC AND SOUTHEAST ON THE NORTHWEST ALOFT BRINGING QUICK THREATS OF PRECIPITATION AND BRIEF SHOTS OF COLDER AIR. THE SOUTHERN STREAM BECOMES MORE ACTIVE LATE IN THE PERIOD SUGGESTING A MILDER PRECIPITATION EVENT POSSIBLE LATE TUESDAY. THE NEXT STORM SYSTEM ASSOCIATED WITH ANOTHER STRONG NORTHERN STREAM WAVE WILL MOVE THROUGH THE AREA FRIDAY NIGHT INTO EARLY SATURDAY. IT APPEARS THE AIRMASS WILL BE SUFFICIENTLY COLD TO MAINTAIN A MENTION OF RAIN MIXING WITH OR CHANGING TO SNOW AS COLD ARCTIC AIR PUSHES INTO THE REGION BEHIND THE FTRONT.CONFIDENCE IN THE DETAILS ASSOCIATED WITH THIS SYSTEM ARE RATHER LOW AS GUIDANCE IS QUITE VARIED BUT AT THIS POINT IT IS LIKELY TO REMAIN A VERY LIGHT QPF EVENT. FAIR WEATHER IS EXPECTED LATER SATURDAY BEFORE THE NEXT SYSTEM IN THE STRONG NORTHWEST FLOW ARRIVES SATURDAY NIGHT. THIS SYSTEM APPEARS EVEN MORE MOISTURE DEPRIVED WITH A TRACK FURTHER NORTH...AND WILL ACCORDINGLY KEEP THE FORECAST DRY. HIGHS IN THE UPPER 30S TO LOWER 40S SATURDAY WILL WARM INTO THE LOWER TO MID 40S SUNDAY AND THE LOWER 50S BY MONDAY. INCREASING CLOUDS ARE EXPECTED ON MONDAY AS THE SOUTHERN STREAM BECOMES MORE ACTIVE AND A BROAD EASTERN U.S. TROUGH SHARPENS SOMEWHATS. TEMPERATURES WILL HAVE MODIFIED SUFFICIENTLY FOR A RAIN P- TYPE AS HIGHS TUESDAY SHOULD RANGE IN THE LOWER TO MID 50S. -BLAES && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 130 AM WEDNESDAY... THE LOW LEVEL FLOW HAS ALREADY BACKED TO SSW IN THE LEE OF THE APPALACHIANS/OVER THE CAROLINAS...AND AS SUCH...THE LOW LEVEL MOISTURE OVER THE CENTRAL AND EASTERN CAROLINAS- AND ASSOCIATED VLIFR VISIBILITY RESTRICTIONS AND CEILINGS - SHOULD ONLY GET WORSE AND EXPAND NORTHWESTWARD THROUGHOUT THE MORNING. IN OTHER WORDS...THERE IS NO DRY AIR COMING OUR WAY TO DISPERSE THE LOW CLOUDS AND FOG THIS MORNING. THE LOW LEVEL MOISTURE IS CONSEQUENTLY APT TO STICK AROUND FOR THE BETTER PART OF THE MORNING TO MIDDAY HOURS...BEFORE MIXING/SCATTERING THROUGH MVFR BETWEEN 14-16Z...AND TO VFR THEREAFTER. ATTENTION WILL THEN TURN TO A SHARPENING UPPER LEVEL TROUGH TO OUR WEST...AND AN ACCOMPANYING ARCTIC COLD FRONT THAT WILL CROSS CENTRAL NC THIS EVENING AND TONIGHT. SCATTERED RAIN SHOWERS WILL BE POSSIBLE IN THE VICINITY OF THE FRONT LATE THIS AFTERNOON AT TRIAD TERMINALS AND THIS EVENING ELSEWHERE...FOLLOWED BY A LARGER BAND OF LIGHT PRECIPITATION THAT WILL OVERSPREADS OUR REGION OVERNIGHT. WITH COLD AIR RUSHING IN BEHIND THE ARCTIC FRONT...THAT BAND OF LIGHT PRECIPITATION WILL FALL AS LIGHT SNOW...AFTER INITIALLY A RAIN/SNOW MIX AT THE ONSET. MVFR CEILINGS AND MVFR-IFR VISIBILITY RESTRICTIONS WILL ACCOMPANY THE LIGHT SNOW BAND. IN ADDITION...NORTHWEST WINDS WILL INCREASE INTO THE 12-15 KT RANGE WITH GUSTS OF 20-25 KTS AS THE DENSE COLD AIR RUSHES IN BEHIND THE FRONT. OUTLOOK: SUB-VFR CONDITIONS AT LIGHT SNOW WILL END FROM WEST TO EAST BETWEEN 09-15Z THU...FOLLOWED BY CLEAR VFR CONDITIONS FOR THE REST OF THU. ANOTHER FRONTAL SYSTEM WILL BRING A CHANCE OF RAIN CHANGING TO SNOW...AND ASSOCIATED SUB-VFR CONDITIONS...LATE FRI-FRI NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MWS NEAR TERM...CBL/DJF SHORT TERM...BLAES LONG TERM...BLAES AVIATION...MWS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1135 PM CST TUE JAN 14 2014 .UPDATE... ISSUED AT 1130 PM CST TUE JAN 14 2014 NO UPDATE NEEDED THIS FORECAST PERIOD. UPDATE ISSUED AT 930 PM CST TUE JAN 14 2014 CLOUD TRENDS AND TEMPERATURES WILL CONTINUE TO BE A CHALLENGE TONIGHT. N-S ORIENTED CLOUD BAND CONTINUES TO SHIFT SLOWLY EAST WITH CLEARING APPROACHING THE RED RIVER PROPER. ABOVE CLOUD BAND HAS HELD TEMPERATURES UP AND WITH SLOW MOVEMENT ADJUSTED TEMPERATURES UP ACROSS W MN. FARTHER WEST ADVANCING CLOUDS/WARM ADVECTION SHOULD LEVEL OFF TEMPERATURES. THIS WILL LEAVE COLDEST TEMPERATURES TONIGHT ACROSS NORTHERN AREAS. MINOR TEMPERATURE AND CLOUD TREND ADJUSTMENTS MAIN CHANGES THIS UPDATE. UPDATE ISSUED AT 620 PM CST TUE JAN 14 2014 EASTWARD PROPAGATION OF CLOUD BAND OVER THE VALLEY HAS SLOWED UP ALLOWING TEMPERATURES TO HOLD UP EARLY THIS EVENING. WILL LEAVE MINIMUMS AS IS AT THIS POINT BUT WILL NEED TO MONITOR CLEARING TRENDS. ONLY CHANGES WERE TO ADJUST CLOUD TRENDS AND EVENING TEMPERATURE CURVE. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 318 PM CST TUE JAN 14 2014 SKY COVER AND TEMPS THE ISSUE TONIGHT. BAND OF STRATOCU CU OVER ERN ND ATTM AND HOW/WHEN THIS CLEARS OUT WILL BE THE ISSUE FOR LOW TEMPS. HRRR AND OTHER SHORT TERM MODELS DO BRING CLEARING TO ERN ND/RRV THIS EVE AND SPREADS IT EAST. WINDS WILL DIMINISH TOO AND WITH LIKELY CLEARING/CLEAR SKY FOR A WHILE TEMPS WILL DROP QUICKLY INTO THE 5 TO 10 BELOW ZERO RANGE MOST AREAS WITH A FEW TEEN BELOW ZERO TEMPS LIKELY IN PARTS OF FAR NW MN. CLOUDS FROM NEXT SYSTEM WILL SPREAD INTO WRN FCST AREA AFTER MIDNIGHT AS WINDS TURN SOUTH AND TEMPS WARM...SO PERIOD OF COLD TEMPS IS SMALL. STRONG 925-850 MB WARM ADVECTION WILL SPREAD WEST TO EAST OVER THE AREA WEDNESDAY...WITH BAND OF LIGHT SNOW WITH IT ENDING AS SOME SLEET/FREEZING RAIN AT THE TAIL END. BUT MODELS DO APPEAR TO BUT MOST OF THE MOISTURE IN THE COLD AIR TO THE EAST OF THE WARM FRONT SO THINK ICING WILL BE MINIMAL. THUS NO ADVISORIES ISSUED. BUT LATER SHIFTS CAN MONITOR. TEMPS WILL WARM SIGNIFICANTLY WED AFTN OVER ERN ND WITH TEMPS 32F OR HIGHER AS 925 MB REACH +2C. IT WILL BE TURN WINDY AS WELL ESP WEST OF THE VALLEY WHERE 45-50 KT 925 MB WINDS WILL BE PRESENT. HOWEVER WITH WARMER AIR COMING OVER THE COLDER SURFACE AN INVERSION WILL BE PRESENT AND THUS MIXING WILL BE LIMITED. THUS DONT ANTICIPATE ANY HEADLINES FOR WIND/BLSN WED AFTN/EVE. VERY CLOSE THOUGH WED EVE AND WILL NEED TO WATCH WIND POTENTIAL. ARCTIC FRONT WILL START DROPPING SOUTH INTO THE FAR NRN VALLEY 06Z-09Z AND THEN PLUNGE SOUTH REACHING FAR SRN FCST AREA SOON AFTER 12Z THU. 925 MB WINDS OF 50 KTS BECOME MORE NORTH-SOUTH AND WITH STRONG SURFACE COOLING SOUNDINGS SHOW ADIABATIC CONDITIONS UP TO AROUND 870 MB. THUS EXPECT THE FRONT TO ARRIVE WITH A STRONG PUNCH ALONG WITH SOME SNOW SHOWERS. THUS EXPECT A QUICK DOWNTURN INTO BLIZZARD CONDITIONS JUST AHEAD AND BEHIND FRONT THRU THE LATE NIGHT WED NIGHT. DID NOT INCLUDE THE FAR EAST (TREES) IN BLIZZARD WATCH. WHILE SNOWFALL WILL END IN ERN ND/RRV WED NIGHT DO LOOK FOR SOME LIGHT SNOW TO LINGER OVER LAKE OF THE WOODS REGION..WHERE TOTAL NEW SNOWFALL OF 1-3 INCHES IS POSSIBLE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 318 PM CST TUE JAN 14 2014 THURSDAY SHOULD SEE BLIZZARD CONDITIONS OVER THE PRAIRIE REGION....ERN ND/RRV (ROX-FFM WESTWARD). STRONG COLD ADVECTION STRONG LAPSE RATES WITH GOOD MIXING OF 50 KT 925 MB WINDS TO THE SFC SHOULD ENSURE BLOWING SNOW AND NEAR ZERO VISIBILITY AT TIMES...ESP OUT OF TOWN. ANY FALLING SNOWFALL WILL ADD TO THE VSBY ISSUES. IT WILL BE A FAST MOVING BLIZZARD IN THAT CONDITIONS WILL IMPROVE LATE IN THE DAY IN THE NORTH AND IN THE EARLY EVENING IN THE SOUTH. CONDITIONS MUCH IMPROVED BY 12Z FRI AS SFC HIGH AND CLEARING MOVE IN WITH LIGHTER WINDS. NEXT WEAK SHORTWAVE WILL MOVE INTO ERN ND FRI AFTN WITH SOME LIGHT SNOW/FLURRIES. FOR THE FRIDAY NIGHT TO TUESDAY TIME FRAME THE FA REMAINS IN NORTHWEST FLOW ALOFT. ONE WEAK SFC LOW PASSES THROUGH THE AREA FRI NIGHT SO LEFT SOME LIGHT SNOW CHANCES WITH IT. ANOTHER WEAK WAVE AND ASSOCIATED SFC LOW PASS NORTH OF THE FA SUN NIGHT WHICH COULD RESULT IN SOME LIGHT SNOW AGAIN MON AND MON NIGHT. NEITHER SYSTEM AT THIS POINT LOOKS VERY IMPRESSIVE FOR PRODUCING MUCH SNOW. THE UP AND DOWN TEMP PATTERN LOOKS TO CONTINUE WITH WARMER AIR MOVING BACK IN ESPECIALLY BY THE WEEKEND FOLLOWED BY COOLER TEMPS FOR EARLY NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1130 PM CST TUE JAN 14 2014 EASTWARD PUSH OF CLOUDS PICKING UP WITH MVFR CIGS CONFINED TO SOUTHERN VALLEY INTO THE EASTERN FA. EXPECT CLEARING TO CONTINUE WITH VFR CONDITIONS EXPECTED BY 09Z OR SO. MORE CLOUDS ADVANCING FROM WEST BUT SHOULD REMAIN VFR UNTIL MID MORNING WITH SNOW BAND MOVES IN. WINDS WILL INCREASE FROM THE S IN THE AM SWITCHING TO THE WEST FROM WEST TO EAST DURING THE AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR NDZ038-039-049-052-053. BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR NDZ006>008-014>016-024-026>030-054. MN...BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING FOR MNZ002-003-022-027-029-030-040. BLIZZARD WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY AFTERNOON FOR MNZ001-004-005-007-008-013>015. && $$ UPDATE...VOELKER SHORT TERM...RIDDLE LONG TERM...GODON/RIDDLE AVIATION...VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1159 PM CST TUE JAN 14 2014 .UPDATE...FOR 06Z AVIATION DISCUSSION. && .AVIATION...06Z AVIATION DISCUSSION. COLD FRONTAL HAS PASSED CSV AS OF 05Z...WITH SOME REPORTS OF LIGHT SNOWFALL ACROSS NRN PORTIONS OF PLATEAU. PER OVERALL CONTINUED LIMITED LOW LEVEL MOISTURE LEVEL BEHIND FRONTAL PASSAGE...MVFR CEILINGS CSV SHOULD IMPROVE TO VFR QUICKLY...WITH A RAIN/SNOW MIX TRANSITIONING TO ALL -SN BY 15/08Z. -SHSN WILL PERSIST ACROSS PLATEAU THRU 16/01Z AND DEVELOP ACROSS CKV/BNA BY AROUND 15/13Z PER LIFT AND MOISTURE ASSOCIATED WITH UPPER LEVEL TROUGH MOVEMENT/PASSAGE ACROSS AREA...BUT AGAIN...OVERALL MINIMAL IMPACTS TO VSBY EXPECTED AND THUS CONTINUED WITH P6SM REFERENCES. VFR CEILINGS EXPECTED THRU 16/00Z ALSO. WITH UPPER LEVEL TROUGH PASSAGE AND DRY NWLY FLOW ALOFT WILL LEAD TO CEILING EROSIONS GENERALLY AFTER 16/01Z. && .PREV DISCUSSION.../ISSUED 1017 PM CST TUE JAN 14 2014/ UPDATE... JUST MADE SOME GRID ADJUSTMENTS AND LOWERED POPS ACROSS THE WEST. THE BACK EDGE OF THE SHOWER BAND NOW EXTENDS FROM LAFAYETTE SW TO WAYNESBORO. HRRR IN AGREEMENT WITH VERY LITTLE IF ANY REDEVELOPMENT TO THE WEST OF THE BAND BETWEEN NOW AND 12Z. LOOKING IN PARTICULAR AT THE PLATEAU ADVISORY AREA...LATEST SOUNDING DATA SUGGESTS THAT SNOW LEVELS WILL BE AROUND 2100 FT MSL AT 06Z. THIS WOULD SUPPORT SNOW ONLY FOR THE FAR EASTERN REACHES OF CUMBERLAND COUNTY. BY 08Z OR 09Z...THE VERTICAL COLUMN WILL BE COLD ENOUGH TO SUPPORT SNOW BUT THE BULK OF THE PRECIP WILL BE EAST OF THE AREA. I HAVE THEREFORE REDUCED POPS SLIGHTLY. THERE IS STILL A WEAK UPSLOPE COMPONENT AND AN UPPER LEVEL DYNAMICAL ENERGY INCREASE EXPECTED BY OR SHORTLY AFTER 12Z. THEREFORE...CONSIDERING ISC GUIDANCE AS WELL...WILL OPT TO KEEP THE ADVISORY GOING BUT THE THREAT OF SNOW LOOKS A LITTLE BETTER AFTER 12Z. PREV DISCUSSION... /ISSUED 629 PM CST TUE JAN 14 2014/ UPDATE... FRONTAL BOUNDARY LOOKS TO BE LOCATED JUST ALONG THE LEADING EDGE OF THE RAIN SHOWER ACTIVITY. THIS LEADING EDGE STRETCHES FROM JUST SOUTHEAST OF CKV SW THROUGH DECATUR COUNTY. TEMPERATURES QUICKLY DROP DOWN INTO THE 40S BEHIND THE FRONT. THE RAINFALL BAND IS RATHER NARROW AND THE AIR SUFFICIENTLY COLD ENOUGH TO SUPPORT ANY SNOWFALL IS WAY UP IN IL AND MO. THUS...THE COLD AIR TO SUPPORT ANY SNOWFALL WILL NOT ARRIVE PRIMARILY DUE TO ADVECTION. DYNAMICAL COOLING IS ALSO EXPECTED AS TROUGHING IN THE UPPER ATMOSPHERE WILL INTENSIFY THROUGH THE NEXT 24 HOURS. IN FACT...BY THE TIME THIS NARROW AREA OF SHOWERS REACHES THE PLATEAU...AROUND MIDNIGHT...850 MB TEMPS FOR THE PLATEAU WILL BE BELOW 0C. THUS...A TRANSITION TO A RAIN AND SNOW MIX IS STILL POSSIBLE FOR THE PLATEAU AS WE GET CLOSER TO MIDNIGHT. ONCE THE AFOREMENTIONED BAND PASSES EAST OF THE MID STATE...UPPER DYNAMICS COULD POTENTIALLY COME INTO PLAY AS PVA MERGES WITH LOW LEVEL MOISTURE AND SOME WESTERLY UPSLOPE COMPONENT. AFTER THIS INITIAL RAIN BAND MOVES THROUGH...MODELS ARE RATHER STINGY WITH THE MOISTURE RETURN. IT DOES HOWEVER LOOK LIKE OCCASIONAL FLURRIES FOR MUCH OF THE MID STATE. ACROSS THE PLATEAU THOUGH...STILL CANNOT RULE OUT SOME ACCUMULATING SNOWFALL WITH TOTAL AMOUNTS OF AROUND AN INCH BEING POSSIBLE. FOR THE FORECAST UPDATE...ONLY CHANGE WILL BE TO INCREASE POPS SLIGHTLY ACROSS WESTERN AND CENTRAL AREAS FOR THE CURRENT RAIN BAND MOVING ACROSS THE AREA THIS EVENING. OTW...I SEE NO REASON TO MODIFY ANY OF THE OTHER GRIDDED DATA AS OF YET. I WILL BE MAKING CURRENT HOUR TEMP ADJUSTMENT TO REMAIN IN LINE WITH THE CURRENT OBS. OTW...NO OTHER CHANGES FOR NOW. PREV DISCUSSION... /ISSUED 608 PM CST TUE JAN 14 2014/ UPDATE...FOR 00Z AVIATION DISCUSSION. AVIATION...00Z AVIATION DISCUSSION. LOOKS LIKE COLD FRONTAL PASSAGE IN PROGRESS AT CKV...AROUND 01Z BNA...AND AS SOON AS 03Z CSV. OVERALL LOW LEVEL LIMITED MOISTURE STILL EXPECTED...AND MAYBE AN EXCURSION INTO MVFR CEILINGS MAINLY BEFORE 05/06Z...BUT VFR CEILINGS SHOULD GENERALLY PREVAIL THROUGHOUT. LOW LEVEL TEMPS APPROACHING FREEZING NOT EXPECTED UNTIL MAINLY AFTER 05/06Z ALSO...AND PER LIMITED MOISTURE...-SN ANTICIPATED ACROSS MUCH OF MID STATE PER CAA SCENARIO AND CONTINUED PER COLD CORE UPPER LEVEL TROUGH PASSAGE EXPECTED ACROSS MID STATE GENERALLY BY 05/24Z ALSO. GREATEST POTENTIAL FOR VSBY RESTRICTIONS CSV BUT MVFR VSBY RESTRICTIONS AT BEST. SOME GUSTY NWLY SFC WINDS UP TO 20KTS PER INITIAL CAA SCENARIO ACROSS AREA...BUT SHOULD DISSIPATE INTO THE 5-10KT RANGE APPROACHING 05/24Z. PREV DISCUSSION.../ISSUED 237 PM CST TUE JAN 14 2014/ DISCUSSION... STRONG COLD FRONT NOTED ON RADAR AND SATELLITE IMAGERY THIS AFTERNOON STRETCHES FROM FSM TO PAH TO IND. LACK OF MOISTURE RETURN AHEAD OF THE BOUNDARY IS LIMITING PRECIP ALONG THE FRONT...WHICH COMPLICATES FURTHER THE ALREADY COMPLICATED SNOW FORECAST FOR TONIGHT AND TOMORROW. 12Z MODEL RUNS INDICATE LIGHT RAIN WILL INCREASE IN COVERAGE SOMEWHAT AS FRONT MOVES ACROSS THE AREA THIS EVENING. AFTER MIDNIGHT...NAM/GFS/SREF BUFKIT SOUNDINGS INDICATE A FEW HOUR WINDOW OF RAIN CHANGING TO SNOW ON THE PLATEAU AS COLDER AIR FILTERS IN BEHIND THE BOUNDARY...WITH UP TO ONE HALF INCH OF SNOW POSSIBLE. DOES NOT APPEAR TO BE MUCH IF ANY OPPORTUNITY FOR A CHANGEOVER ACROSS THE REST OF THE CWA WITH THIS INITIAL PRECIP TONIGHT AS PRECIP WILL LIKELY OUTRACE THE CAA. A BETTER CHANCE FOR SNOW APPEARS TO EXIST DURING THE DAY ON WEDNESDAY AREAWIDE AS UPPER TROUGH MOVES ACROSS MIDDLE TENNESSEE...WITH VERY COLD TEMPERATURES ALOFT DOWN AS LOW AS -13C AT 850MB AND -34C AT 500 MB. THIS SETUP WILL CREATE UNUSUALLY UNSTABLE LOW LEVELS BY LATE MORNING AND AFTERNOON DESPITE SURFACE TEMPERATURES ONLY IN THE 20S AND 30S ACROSS THE CWA. THUS WIDELY SCATTERED CONVECTIVE SNOW SHOWERS/BANDS ARE EXPECTED TO FORM THROUGHOUT THE FORECAST AREA...WITH 12Z 4KM WRF ACTUALLY INDICATING FAIRLY WIDESPREAD COVERAGE OF SNOW SHOWERS. AS THESE SHOWERS ARE FORCED UP THE HIGHER TERRAIN OF THE PLATEAU...ANTICIPATING ADDITIONAL SNOW ACCUMS THERE AROUND ONE HALF INCH OR SO FOR TOTAL AMOUNTS GENERALLY AROUND 1 INCH...POSSIBLY MORE. A DUSTING IS NOT OUT OF THE QUESTION IN OTHER PARTS OF THE CWA WHERE SNOW SHOWERS PERSIST. BASED ON THIS REASONING...HAVE KEPT WINTER WEATHER ADVISORY INTACT FOR EASTERN ZONES BUT TRIMMED IT BACK TO JUST THE PLATEAU COUNTIES WHERE 1 INCH TOTAL ACCUMS ARE MORE LIKELY. ALSO EXTENDED THE ADVISORY IN TIME TO 16/00Z BASED ON THE EXPECTED DIURNAL CONVECTIVE SNOW SHOWERS. WHERE SNOW ACCUMULATES...SOME ROAD IMPACTS ARE POSSIBLE EVEN INTO THURSDAY MORNING AS TEMPERATURES DROP INTO THE TEENS AND 20S. THANKS TO MRX...LMK...AND JKL FOR COORDINATION ON THIS. A VERY ACTIVE WEATHER PATTERN IS IN STORE FOR THE MID STATE OVER THE NEXT WEEK AS A PARADE OF CLIPPER-TYPE SYSTEMS MOVES ACROSS IN A NEAR DAILY FASHION. A BRIEF WARMUP WILL OCCUR THURSDAY BEFORE THE NEXT ROUND OF POTENTIAL RAIN AND SNOW SHOWERS SWEEPS THROUGH THURSDAY NIGHT AND FRIDAY. MORE MOISTURE APPEARS TO BE AVAILABLE WITH THIS SYSTEM AND THUS BETTER CHANCES FOR MORE WIDESPREAD ALTHOUGH STILL LIGHT SNOW ACCUMS. GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT IN THE HANDLING OF SYSTEMS FROM SATURDAY ONWARD WITH GFS MORE AGGRESSIVE WITH QPF...SO HAVE SPLIT THE DIFFERENCE WITH LOW POPS SATURDAY/SATURDAY NIGHT AND MONDAY NIGHT/TUESDAY. TEMPERATURES WILL BE ON A ROLLER COASTER RIDE OF BRIEF WARM UPS WITH SIGNIFICANT COOL DOWNS...AND KEPT TEMPS GENERALLY CLOSE TO MAV/MEX GUIDANCE. && .OHX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR TNZ011- 032>034-065-066-078>080. && $$ 31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1017 PM CST TUE JAN 14 2014 .UPDATE... JUST MADE SOME GRID ADJUSTMENTS AND LOWERED POPS ACROSS THE WEST. THE BACK EDGE OF THE SHOWER BAND NOW EXTENDS FROM LAFAYETTE SW TO WAYNESBORO. HRRR IN AGREEMENT WITH VERY LITTLE IF ANY REDEVELOPMENT TO THE WEST OF THE BAND BETWEEN NOW AND 12Z. LOOKING IN PARTICULAR AT THE PLATEAU ADVISORY AREA...LATEST SOUNDING DATA SUGGESTS THAT SNOW LEVELS WILL BE AROUND 2100 FT MSL AT 06Z. THIS WOULD SUPPORT SNOW ONLY FOR THE FAR EASTERN REACHES OF CUMBERLAND COUNTY. BY 08Z OR 09Z...THE VERTICAL COLUMN WILL BE COLD ENOUGH TO SUPPORT SNOW BUT THE BULK OF THE PRECIP WILL BE EAST OF THE AREA. I HAVE THEREFORE REDUCED POPS SLIGHTLY. THERE IS STILL A WEAK UPSLOPE COMPONENT AND AN UPPER LEVEL DYNAMICAL ENERGY INCREASE EXPECTED BY OR SHORTLY AFTER 12Z. THEREFORE...CONSIDERING ISC GUIDANCE AS WELL...WILL OPT TO KEEP THE ADVISORY GOING BUT THE THREAT OF SNOW LOOKS A LITTLE BETTER AFTER 12Z. && .PREV DISCUSSION... /ISSUED 629 PM CST TUE JAN 14 2014/ UPDATE... FRONTAL BOUNDARY LOOKS TO BE LOCATED JUST ALONG THE LEADING EDGE OF THE RAIN SHOWER ACTIVITY. THIS LEADING EDGE STRETCHES FROM JUST SOUTHEAST OF CKV SW THROUGH DECATUR COUNTY. TEMPERATURES QUICKLY DROP DOWN INTO THE 40S BEHIND THE FRONT. THE RAINFALL BAND IS RATHER NARROW AND THE AIR SUFFICIENTLY COLD ENOUGH TO SUPPORT ANY SNOWFALL IS WAY UP IN IL AND MO. THUS...THE COLD AIR TO SUPPORT ANY SNOWFALL WILL NOT ARRIVE PRIMARILY DUE TO ADVECTION. DYNAMICAL COOLING IS ALSO EXPECTED AS TROUGHING IN THE UPPER ATMOSPHERE WILL INTENSIFY THROUGH THE NEXT 24 HOURS. IN FACT...BY THE TIME THIS NARROW AREA OF SHOWERS REACHES THE PLATEAU...AROUND MIDNIGHT...850 MB TEMPS FOR THE PLATEAU WILL BE BELOW 0C. THUS...A TRANSITION TO A RAIN AND SNOW MIX IS STILL POSSIBLE FOR THE PLATEAU AS WE GET CLOSER TO MIDNIGHT. ONCE THE AFOREMENTIONED BAND PASSES EAST OF THE MID STATE...UPPER DYNAMICS COULD POTENTIALLY COME INTO PLAY AS PVA MERGES WITH LOW LEVEL MOISTURE AND SOME WESTERLY UPSLOPE COMPONENT. AFTER THIS INITIAL RAIN BAND MOVES THROUGH...MODELS ARE RATHER STINGY WITH THE MOISTURE RETURN. IT DOES HOWEVER LOOK LIKE OCCASIONAL FLURRIES FOR MUCH OF THE MID STATE. ACROSS THE PLATEAU THOUGH...STILL CANNOT RULE OUT SOME ACCUMULATING SNOWFALL WITH TOTAL AMOUNTS OF AROUND AN INCH BEING POSSIBLE. FOR THE FORECAST UPDATE...ONLY CHANGE WILL BE TO INCREASE POPS SLIGHTLY ACROSS WESTERN AND CENTRAL AREAS FOR THE CURRENT RAIN BAND MOVING ACROSS THE AREA THIS EVENING. OTW...I SEE NO REASON TO MODIFY ANY OF THE OTHER GRIDDED DATA AS OF YET. I WILL BE MAKING CURRENT HOUR TEMP ADJUSTMENT TO REMAIN IN LINE WITH THE CURRENT OBS. OTW...NO OTHER CHANGES FOR NOW. PREV DISCUSSION... /ISSUED 608 PM CST TUE JAN 14 2014/ UPDATE...FOR 00Z AVIATION DISCUSSION. AVIATION...00Z AVIATION DISCUSSION. LOOKS LIKE COLD FRONTAL PASSAGE IN PROGRESS AT CKV...AROUND 01Z BNA...AND AS SOON AS 03Z CSV. OVERALL LOW LEVEL LIMITED MOISTURE STILL EXPECTED...AND MAYBE AN EXCURSION INTO MVFR CEILINGS MAINLY BEFORE 05/06Z...BUT VFR CEILINGS SHOULD GENERALLY PREVAIL THROUGHOUT. LOW LEVEL TEMPS APPROACHING FREEZING NOT EXPECTED UNTIL MAINLY AFTER 05/06Z ALSO...AND PER LIMITED MOISTURE...-SN ANTICIPATED ACROSS MUCH OF MID STATE PER CAA SCENARIO AND CONTINUED PER COLD CORE UPPER LEVEL TROUGH PASSAGE EXPECTED ACROSS MID STATE GENERALLY BY 05/24Z ALSO. GREATEST POTENTIAL FOR VSBY RESTRICTIONS CSV BUT MVFR VSBY RESTRICTIONS AT BEST. SOME GUSTY NWLY SFC WINDS UP TO 20KTS PER INITIAL CAA SCENARIO ACROSS AREA...BUT SHOULD DISSIPATE INTO THE 5-10KT RANGE APPROACHING 05/24Z. PREV DISCUSSION.../ISSUED 237 PM CST TUE JAN 14 2014/ DISCUSSION... STRONG COLD FRONT NOTED ON RADAR AND SATELLITE IMAGERY THIS AFTERNOON STRETCHES FROM FSM TO PAH TO IND. LACK OF MOISTURE RETURN AHEAD OF THE BOUNDARY IS LIMITING PRECIP ALONG THE FRONT...WHICH COMPLICATES FURTHER THE ALREADY COMPLICATED SNOW FORECAST FOR TONIGHT AND TOMORROW. 12Z MODEL RUNS INDICATE LIGHT RAIN WILL INCREASE IN COVERAGE SOMEWHAT AS FRONT MOVES ACROSS THE AREA THIS EVENING. AFTER MIDNIGHT...NAM/GFS/SREF BUFKIT SOUNDINGS INDICATE A FEW HOUR WINDOW OF RAIN CHANGING TO SNOW ON THE PLATEAU AS COLDER AIR FILTERS IN BEHIND THE BOUNDARY...WITH UP TO ONE HALF INCH OF SNOW POSSIBLE. DOES NOT APPEAR TO BE MUCH IF ANY OPPORTUNITY FOR A CHANGEOVER ACROSS THE REST OF THE CWA WITH THIS INITIAL PRECIP TONIGHT AS PRECIP WILL LIKELY OUTRACE THE CAA. A BETTER CHANCE FOR SNOW APPEARS TO EXIST DURING THE DAY ON WEDNESDAY AREAWIDE AS UPPER TROUGH MOVES ACROSS MIDDLE TENNESSEE...WITH VERY COLD TEMPERATURES ALOFT DOWN AS LOW AS -13C AT 850MB AND -34C AT 500 MB. THIS SETUP WILL CREATE UNUSUALLY UNSTABLE LOW LEVELS BY LATE MORNING AND AFTERNOON DESPITE SURFACE TEMPERATURES ONLY IN THE 20S AND 30S ACROSS THE CWA. THUS WIDELY SCATTERED CONVECTIVE SNOW SHOWERS/BANDS ARE EXPECTED TO FORM THROUGHOUT THE FORECAST AREA...WITH 12Z 4KM WRF ACTUALLY INDICATING FAIRLY WIDESPREAD COVERAGE OF SNOW SHOWERS. AS THESE SHOWERS ARE FORCED UP THE HIGHER TERRAIN OF THE PLATEAU...ANTICIPATING ADDITIONAL SNOW ACCUMS THERE AROUND ONE HALF INCH OR SO FOR TOTAL AMOUNTS GENERALLY AROUND 1 INCH...POSSIBLY MORE. A DUSTING IS NOT OUT OF THE QUESTION IN OTHER PARTS OF THE CWA WHERE SNOW SHOWERS PERSIST. BASED ON THIS REASONING...HAVE KEPT WINTER WEATHER ADVISORY INTACT FOR EASTERN ZONES BUT TRIMMED IT BACK TO JUST THE PLATEAU COUNTIES WHERE 1 INCH TOTAL ACCUMS ARE MORE LIKELY. ALSO EXTENDED THE ADVISORY IN TIME TO 16/00Z BASED ON THE EXPECTED DIURNAL CONVECTIVE SNOW SHOWERS. WHERE SNOW ACCUMULATES...SOME ROAD IMPACTS ARE POSSIBLE EVEN INTO THURSDAY MORNING AS TEMPERATURES DROP INTO THE TEENS AND 20S. THANKS TO MRX...LMK...AND JKL FOR COORDINATION ON THIS. A VERY ACTIVE WEATHER PATTERN IS IN STORE FOR THE MID STATE OVER THE NEXT WEEK AS A PARADE OF CLIPPER-TYPE SYSTEMS MOVES ACROSS IN A NEAR DAILY FASHION. A BRIEF WARMUP WILL OCCUR THURSDAY BEFORE THE NEXT ROUND OF POTENTIAL RAIN AND SNOW SHOWERS SWEEPS THROUGH THURSDAY NIGHT AND FRIDAY. MORE MOISTURE APPEARS TO BE AVAILABLE WITH THIS SYSTEM AND THUS BETTER CHANCES FOR MORE WIDESPREAD ALTHOUGH STILL LIGHT SNOW ACCUMS. GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT IN THE HANDLING OF SYSTEMS FROM SATURDAY ONWARD WITH GFS MORE AGGRESSIVE WITH QPF...SO HAVE SPLIT THE DIFFERENCE WITH LOW POPS SATURDAY/SATURDAY NIGHT AND MONDAY NIGHT/TUESDAY. TEMPERATURES WILL BE ON A ROLLER COASTER RIDE OF BRIEF WARM UPS WITH SIGNIFICANT COOL DOWNS...AND KEPT TEMPS GENERALLY CLOSE TO MAV/MEX GUIDANCE. && .OHX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR TNZ011- 032>034-065-066-078>080. && $$ 21
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1046 PM CST TUE JAN 14 2014 .DISCUSSION...SEE 06Z AVIATION DISCUSSION. && .AVIATION...GUSTY NORTH WINDS TONIGHT WILL DIE DOWN BY 15Z ALL BUT KCRP WHERE WINDS MAY STAY UP A BIT LONGER (AS USUAL). WINDS BECOME LIGHT AND MAINLY SOUTHERLY AROUND SUNSET (DIE DOWN FIRST...THEN BECOME SOUTHERLY AFTER 16/00Z. && .PREV DISCUSSION... /ISSUED 912 PM CST TUE JAN 14 2014/ DISCUSSION...BASED ON RADAR...COLD FRONTAL BDRY IS PUSHING THROUGH THE CWA AND SHOULD REACH CORPUS AROUND 04Z. HAVE MADE SOME TWEAKS TO THE DEWPOINTS AND WINDS BASED ON CURRENT TRENDS BEHIND THE FRONTAL BDRY. THESE TWEAKS INCLUDED LOWERING DEWPOINTS ACROSS THE W CWA BY A FEW DEGREES BASED ON MSAS ANALYSIS WITH DEWPOINTS COMING BACK UP BY A FEW DEGREES OVERNIGHT. ALSO INCREASED WIND SPEEDS BY A COUPLE OF KNOTS. TIMING OF SMALL CRAFT ADVISORY LOOKS GOOD BUT HAVE INCLUDED NRN BAYS IN THE ADVISORY AS WELL. UPDATES WILL BE OUT SHORTLY. PREV DISCUSSION... /ISSUED 531 PM CST TUE JAN 14 2014/ DISCUSSION...SEE 00Z AVIATION DISCUSSION. AVIATION...MAIN ISSUE IS TIMING OF FRONT...THEN HOW LONG WINDS STAY UP BEFORE DIMINISHING (AND KEEPING EVERYTHING RELATIVELY SHORT SINCE NO OTHER SIGNIFICANT WEATHER). USING HRRR AND TTU 4 KM MODELS...AM GOING WITH WIND SHIFT ABT 03Z AT KVCT...ABT 04Z AT KRLD AND 05Z AT KCRP/KALI (GIVE OR TAKE 30 MINUTES). AM GOING TO KEEP WINDS UP TIL AT LEAST 12Z...THEN DIMINISH FROM WEST TO EAST DURING THE DAY ON THE 15TH. WITH WINDS UP FOR THE EVENING AND OVERNIGHT PERIOD...WIND SHEAR SHOULD BE NO PROBLEM. OTHERWISE...SKC. PREV DISCUSSION... /ISSUED 325 PM CST TUE JAN 14 2014/ SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...COLD FRONT WILL MOVE THROUGH CWA JUST BEFORE MIDNIGHT TONIGHT...BRINGING NORTHERLY WINDS AROUND 15 KT OVER LAND AND 25 KT OFFSHORE. WEDNESDAY AFTERNOON SHOULD SEE A SURFACE HIGH BEHIND THE FRONT SETTLE INTO THE FORECAST AREA. AS THE CENTER OF HIGH PRESSURE TOMORROW WILL BE LOCATED OVER THE RIO GRANDE VALLEY...EXPECTING LIGHT WESTERLY WINDS. BY TOMORROW NIGHT...SURFACE HIGH PRESSURE WILL SHIFT EAST AND MOVE OVER THE WESTERN GOM WHICH WILL ALLOW ONSHORE FLOW TO RESUME AND INCREASE LOW LEVEL MOISTURE. THE LACK OF ANY MOISTURE WILL KEEP POPS TO ZERO AND KEEP SKIES CLEAR THROUGH THE SHORT TERM. CLEAR SKIES TONIGHT SHOULD ALLOW FOR LOWS IN THE LOWER 40S OVER THE SOUTHERN BRUSH COUNTRY AND SOUTHERN COASTAL BEND AND THE UPPER 30S OVER THE NORTHERN COUNTIES. HIGHS TOMORROW BEHIND THE FRONT WILL BE IN THE 60S ACROSS MOST OF THE AREA WITH SOME UPPER 50S OFFSHORE. COOLER AIR BEHIND THE FRONT AND ANOTHER CLEAR AND CALM NIGHT WILL LEAD TO LOWS IN THE MID 30S INLAND AND LOWER 40S NEAR THE COAST...AS WELL AS THE WESTERN BRUSH COUNTRY. MARINE...INCREASING NORTHERLY WINDS BEHIND TONIGHTS FRONT WILL INCREASE OFFSHORE WINDS TO 20-25 KT BETWEEN 6 AND 18Z. ADDITIONALLY...WAVE HEIGHTS AROUND 7 FEET ARE EXPECTED IN THE OFFSHORE ZONES. A SMALL CRAFT ADVISORY WILL BE IN EFFECT FROM 6 TO 12Z OVER THE SOUTHERN BAYS AND WATERWAYS...AND 6 TO 18Z OVER THE OFFSHORE WATERS. TOMORROW AFTERNOON WILL SEE A RETURN TO CALMER CONDITIONS. LONG TERM (THURSDAY THROUGH TUESDAY)...WEATHER ON THURSDAY EXPECTED TO BE QUITE NICE WITH A DRY ATMOSPHERIC COLUMN LEADING TO A PLETHORA OF SUNSHINE DURING THE DAY. ANOTHER COLD FRONT WILL SLIP SOUTH INTO THE REGION THURSDAY NIGHT BUT LACK OF ANY SUFFICIENT MOISTURE SHOULD PRECLUDE ANY SIGNIFICANT PRECIP FROM OCCURRING. TIMING DIFFERENCES EXIST BETWEEN GUIDANCE WITH GFS BEING FASTER AND ECMWF/NAM BEING A LITTLE SLOWER. OFFICIAL FORECAST PACKAGE HAS FROPA OCCURRING BETWEEN MIDNIGHT AND SUNRISE WITH A PERIOD OF GUSTY NORTH WINDS POST FROPA. SURFACE HIGH PRESSURE PROG TO QUICKLY BUILD IN AND THEN MOVE TO THE EAST DURING THE DAY FRIDAY WITH SOUTHERLY LLVL FLOW RETURNING BY THE WEEKEND. THIS SHOULD RESULT IN AN INCREASE IN LLVL MOISTURE AND ASSOCIATED CLOUD COVER...WITH THICKEST CLOUD COVER LOCATED ACROSS EASTERN HALF OF CWA. WITH MOISTURE PROG TO BE LIMITED TO ONLY THE LOWER LEVELS...CHANCES OF RAIN WILL REMAIN LOW TO NIL THROUGH THE WEEKEND. A MORE POTENT COLD FRONT MAY APPROACH THE AREA BY LATE IN THE EXTENDED FORECAST. FRIDAY WILL LIKELY BE THE COOLEST DAY OF THE EXTENDED PERIOD WITH HIGHS ONLY IN THE UPPER 60S TO AROUND 70. SSW LLVL WIND PROFILE OVER THE WEEKEND SHOULD HELP WARM DAYTIME TEMPS THROUGH THE 70S WITH SOME LOCATIONS TOUCHING 80 AT TIMES. MIN TEMPS WILL GRADUALLY MODIFY EACH NIGHT FROM THE 30S/40S THURSDAY NIGHT INTO THE 40S/50S OVER THE WEEKEND/EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 42 64 38 73 45 / 0 0 0 0 10 VICTORIA 37 63 35 70 40 / 0 0 0 0 10 LAREDO 42 64 42 74 45 / 0 0 0 0 0 ALICE 41 65 36 74 43 / 0 0 0 0 10 ROCKPORT 42 61 42 67 45 / 0 0 0 0 10 COTULLA 39 63 36 73 38 / 0 0 0 0 0 KINGSVILLE 41 65 35 75 44 / 0 0 0 0 10 NAVY CORPUS 47 62 44 69 48 / 0 0 0 0 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL NOON CST WEDNESDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS... BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR. && $$ GW/86...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1016 AM EST WED JAN 15 2014 .UPDATE... ISSUED AT 958 AM EST WED JAN 15 2014 THE GRIDS AND ZFP WERE UPDATED BASED ON RECENT OBSERVATION AND RADAR TRENDS. THE BAND OF SNOW CONTINUES TO EXIT PIKE COUNTY WITH A FEW SNOW SHOWERS LINGERING BACK TO THE SOUTHWEST OVER HARLAN AND LETCHER COUNTIES. THESE SHOULD MOVE INTO VA WV WITHIN THE NEXT HALF HOUR TO AN HOUR. A LULL IS THEN ANTICIPATED IN ANY SNOW SHOWER OR FLURRY ACTIVITY UNTIL A MID LEVEL TROUGH APPROACHES THE REGION AND LEADS TO STEEPER LAPSE RATES. RADAR RETURNS ARE UPSTREAM NEAR THE OH RIVER AND OVER PARTS OF INDIANA. SOME VISIBILITIES HAVE BEEN DOWN BELOW 4 SM OVER INDIANA AND AS THESE ROTATE TOWARD THE REGION THE ACTIVITY WILL PROBABLY BE A CONSIDERABLE AMOUNT OF FLURRIES WITH SOME SNOW SHOWERS AS WELL. HAVE OPTED TO GO WITH ISOLATED SNOW SHOWERS VERSUS JUST SCATTERED OR ISOLATED FLURRIES FOR WEATHER THIS AFTERNOON. THE 12Z NAM AND RECENT HRRR RUNS ARE ESSENTIALLY DRY HOWEVER. TEMPERATURES SHOULD NOT RISE MUCH...BUT WILL GO UP AND DOWN AS BREAKS IN THE CLOUD COVER AND BANDS OF CLOUDS WORK OVERHEAD. UPDATE ISSUED AT 640 AM EST WED JAN 15 2014 FORECAST LOOKING GOOD SO FAR THIS MORNING. A BAND OF SNOW SHOWERS THAT HAS BEEN MOVING ACROSS EASTERN KENTUCKY MOST OF THE NIGHT WILL FINALLY BE EXITING THE AREA BETWEEN 12 AND 14Z THIS MORNING. AFTER A BRIEF REPRIEVE...FLURRIES AND SNOW SHOWERS THAT ARE CURRENTLY MOVING ACROSS THE OHIO RIVER OUT OF INDIANA...MAY MAKE THERE WAY ACROSS EASTERN KENTUCKY LATER THIS MORNING. THE GRIDS REFLECT THIS ALREADY...WITH FLURRIES POSSIBLE EARLY THIS MORNING...AND ISOLATED SNOW SHOWERS POSSIBLE IN THE FAVORED UPSLOPE TERRAIN THIS AFTERNOON AND EVENING. LITTLE IF ANY ACCUMULATION IS EXPECTED. && .SHORT TERM...(TODAY THROUGH THURSDAY) ISSUED AT 354 AM EST WED JAN 15 2014 WILL BE ISSUING THE NEW FORECAST PACKAGE AND HAZARDOUS WEATHER OUTLOOK IN THE NEXT LITTLE BIT. BASED ON CURRENT MODEL DATA...MAINLY FROM THE SREF AND GFS...DECIDED TO TAKE PRECIPITATION OUT OF THE AREA BY 11 OR 12Z THIS MORNING. EXPECTING SOME SNOW FLURRIES AND A FEW SNOW SHOWERS TO FORM ACROSS THE AREA BY 15 OR 16Z TODAY...AS A WEAK WAVE OF LOW PRESSURE MOVES OUT OF THE WESTERN GREAT LAKES AND SINKS SOUTHEASTWARD ACROSS THE OHIO VALLEY. LITTLE IF ANY ACCUMULATIONS ARE EXPECTED FROM THESE FLURRIES AND SHOWERS. THE SNOW SHOULD BE COMING TO AN END AROUND 0Z THIS EVENING AS THE SHORT WAVE MOVES OFF TO THE EAST OF THE AREA. THE WEATHER LOOKS TO BE COLD AND DRY TONIGHT AND MOST OF THE DAY ON THURSDAY...AS A WEAK AREA OF HIGH PRESSURE BRIEFLY SETTLES OVER THE AREA. ANOTHER MORE VIGOROUS WAVE OF LOW PRESSURE SHOULD BEGIN SPREADING A FEW RAIN AND SNOW SHOWERS ACROSS THE AREA THIS EVENING. TODAYS HIGHS WILL LIKELY NOT MAKE IT OUT OF THE LOWER 30S...AS CLOUD COVER WILL BE SLOW TO BREAK UP...AND WITH WEST TO NORTHWEST WINDS BRINGING COLDER AIR INTO THE AREA. TONIGHTS LOWS WILL BE QUITE COLD...WITH THE MERCURY DIPPING INTO THE MID TO UPPER TEENS ACROSS THE AREA...AS A VERY COLD AIR MASS SETTLES OVER THE REGION OVERNIGHT. WINDS WILL BE STRONGER AND MORE GUSTY ON THURSDAY THAN TODAY...AS THE PRESSURE GRADIENT TIGHTENS ACROSS THE AREA AS THE SHORTWAVE APPROACHES FROM THE NORTHWEST. HIGHS ON THURSDAY SHOULD BE A BIT WARMER...AS CLOUDS WILL BE SCATTERED EARLY ON AND WINDS WILL BE OUT OF THE SOUTH THROUGHOUT THE DAY. HIGHS ON THURSDAY WILL CLIMB TO BETWEEN 36 AND 41 DEGREES ACROSS EASTERN KENTUCKY. .LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY) ISSUED AT 451 AM EST WED JAN 15 2014 ALTHOUGH FAR FROM PERFECT...MODELS HAVE COME INTO MUCH BETTER AGREEMENT FOR THE PERIOD. ANOTHER COLD FRONT...ACCOMPANIED BY A SHORTWAVE TROUGH...WILL MOVE EAST OVER THE REGION ON THURSDAY NIGHT INTO FRIDAY. FORECAST SOUNDINGS SHOW A MOIST LAYER WITH STEEP LAPSE RATES EXTENDING TO BETWEEN -15 AND -20 AT 8KT FT MSL. THIS WOULD FAVOR SNOW SHOWERS AND HAVE USED 40-50 PERCENT POPS. MOS IS SHOWING EVEN HIGHER POP VALUES...AND IF THIS PERSISTS...THE FORECAST POP MAY NEED TO BE RAISED IN FUTURE UPDATES. AFTER A LULL IN PRECIP LATE FRIDAY NIGHT INTO SATURDAY...ANOTHER SHORTWAVE IMPULSE IS EXPECTED TO DIVE SOUTHEAST TOWARD THE AREA ALONG WITH AN ASSOCIATED CLIPPER TYPE SURFACE LOW. IT PRESENTS ANOTHER POSSIBILITY OF SNOW LATE SATURDAY AND SATURDAY NIGHT. MOISTURE WILL BE LIMITED...AND THE SURFACE LOW TRACK IS EXPECTED TO BE NEAR OR JUST NORTH OF THE LOCAL AREA...WHICH WOULD PLACE THE GREATEST THREAT OF ACCUMULATING SNOW TO OUR NORTH. ONCE THIS SYSTEM PASSES BY...THE UPPER LEVEL FLOW WILL FLATTEN AND BECOME MORE ZONAL...WITH ANOTHER CORRESPONDING LULL IN THE WEATHER. MODELS SHOW YET ANOTHER STRONG IMPULSE DROPPING IN FROM THE NW BY LATE TUESDAY. THE INITIAL SURFACE LOW WITH THIS IS EXPECTED TO BE WELL TO OUR NORTH...WITH SUBSEQUENT DEVELOPMENT OFF THE EAST COAST. THIS WOULD NOT FAVOR MUCH PRECIP FOR THE FORECAST AREA...BUT SNOW SHOWERS CAN NOT BE RULED OUT IN A STEEP LOW LEVEL LAPSE RATE ENVIRONMENT AS COLDER AIR ARRIVES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 640 AM EST WED JAN 15 2014 A BAND OF LIGHT SNOW SHOWERS CONTINUES TO MOVE ACROSS EASTERN KENTUCKY EARLY THIS MORNING. THESE SHOWERS ARE EXPECTED TO EXIT THE AREA BETWEEN 12 AND 14Z. THE TAF SITES CAN EXPECT TO BE PRECIPITATION FREE UNTIL LATER THIS MORNING AND THIS AFTERNOON...WHEN FLURRIES AND ISOLATED SNOW SHOWERS MAY AFFECT THE AREA ONCE AGAIN. DUE TO THE ISOLATED AND SCATTERED NATURE OF THE FLURRIES AND SNOW SHOWERS...THE TAFS WILL ONLY REFLECT VCSH FROM 15Z ONWARD TODAY. MVFR CONDITIONS WILL BE POSSIBLE AS THE LOW LEVEL CLOUD COVER THAT WILL SPAWN ANY SNOW MOVES IN FROM THE WEST. WINDS SHOULD NOT BE MUCH OF AN ISSUE TODAY...WITH WEST TO NORTHWEST FLOW OF 5 TO 15 MPH. THE SNOW SHOULD BE ENDING ACROSS THE AREA BY 0Z THIS EVENING. TONIGHT LOOKS TO BE QUIET AND DRY WITH VFR CONDITIONS EXPECTED. WINDS COULD BE A BIT STRONGER TOMORROW...WITH SOUTHERLY FLOW OF 10 TO 15 AND GUSTS TO 25 MPH POSSIBLE...AS ANOTHER WEATHER SYSTEM APPROACHES FROM THE NORTHWEST. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JP SHORT TERM...AR LONG TERM...HAL AVIATION...AR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
648 AM EST WED JAN 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 453 AM EST WED JAN 15 2014 THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES. WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL 15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING. FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT. THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW DIMINISHES. OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS. AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER TEENS. 12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15 OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS (20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO NOT THINK THAT IS ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT HOURS...THE SOCIETAL IMPACT WILL BE LIMITED. SINCE WORDING WOULD BE SIMILAR TO WHAT IS IN THE HWO...WILL NOT ISSUE AN SPS. ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 542 AM EST WED JAN 15 2014 LARGE SCALE PATTERN THROUGH THE EXTENDED CONSISTS OF A MEAN RIDGE OVER WRN NORTH AMERICA WHILE A TROUGH DOMINATES DOMINATES MUCH OF ERN NORTH AMERICA...INCLUDING THE GREAT LAKES. STRONGEST CLIPPER SHORTWAVE MOVING THROUGH THE TROUGH CROSSES THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH EARLY FRIDAY. DAYTIME HIGHS WILL END UP SLIGHTLY BLO NORMAL FOR MUCH OF THE TIME. ONE OF THE WARMEST DAYS OF THE EXTENDED WILL BE ON THURSDAY AHEAD OF STRONGER COLD FRONT ASSOC WITH INITIAL CLIPPER SHORTWAVE. BRIEF WARMING MAY OCCUR NEXT MONDAY ONLY TO BE FOLLOWED BY ANOTHER CLIPPER SHORTWAVE AND BLAST OF ARCTIC AIR ON TUESDAY. THURSDAY AND FRIDAY...SYSTEM SNOW WILL GENERALLY BE TAPERING OFF THU MORNING AS THE BEST WAA/ISENTROPIC LIFT BEGINS TO SHIFT EAST. ALSO LAKE ENHANCED SNOW OVER THE ERN COUNTIES SHOULD BE TAPERING OFF BY LATE THU MORNING AS OVERWATER INSTABILITY WEAKENS WITH WARMER TEMPS -7C TEMPS MOVING OVER NRN LAKE MI. MODELS DIFFER ON EVOLUTION/TRACK OF SFC LOW MOVING THROUGH THE CWA THU INTO THU NIGHT. THE GFS AND ECMWF ARE DEEPER INITIALLY WITH THE SFC LOW THAN EITHER THE NAM/GEM-NH OR UKMET. THE GFS/NAM AND UKMET TRACK THE SFC LOW ACROSS UPPER MI ON THU WHILE THE ECMWF AND GEM-NH TAKE THE LOW JUST SOUTH OF THE WI BDR. ALL MODELS NOW APPEAR TO SHOW THE LOW FILLING AS IT TRACKS ACROSS THE UPPER GREAT LAKES ON THU AND THEN EAST OF THE REGION FRI INTO FRI NIGHT. IT ALSO APPEARS THAT ALL THE MODELS ARE TRENDING FARTHER WEST WITH HEART OF COLDEST 8H TEMPS (-20C OR COLDER) MOVING THROUGH THE NRN AND CENTRAL PLAINS INSTEAD OF THE UPPER GREAT LAKES REGION. THE COMBINATION OF THE WEAKENING SFC LOW AND WEAKER OVERWATER INSTABILITY WITH FCST 8H TEMPS OF -15 TO 18C WILL LIKELY RESULT IN LESS LAKE EFFECT SNOW AND BLOWING SNOW BEHIND THE SYSTEM THAN ORIGINALLY THOUGHT. HOWEVER...THERE WILL STILL BE A GOOD CHANCE FOR ADVISORY CRITERIA LAKE EFFECT SNOWFALL OVER THE WRN CWA THU AFTERNOON INTO FRI MORNING...AND OVER THE NCNTRL COUNTIES LATE THU NIGHT INTO FRIDAY WHEN THESE COLDER TEMPS SPREAD FROM WEST TO EAST ACROSS LAKE SUPERIOR IN THE WAKE OF THE FRONTAL PASSAGE IN A CYCLONIC CONVERGENT NRLY FLOW. A PERIOD OF GUSTY NRLY WINDS TO PERHAPS TO 30 MPH IS STILL POSSIBLE...ESPECIALLY ALONG LAKE SUPERIOR...WHICH COULD ALSO CAUSE CONSIDERABLE BLOWING AND DRIFTING OF SNOW ALONG WITH LOWERED VSBY. WAS LEANING TOWARD ISSUING A SPS TO HIGHLIGHT THE POTENTIAL FOR MODERATE LES AND BLOWING SNOW FOR WEST AND NCNTRL COUNTIES THU AFTERNOON INTO FRI MORNING...BUT OPTED TO STAY WITH HWO SINCE WORDING WOULD BE VERY SIMILAR. BY THE TIME THE COLDEST 8H TEMPS REACH INTO THE ERN HALF OF THE LAKE LATE FRI MORNING...THE NRLY FLOW WILL BE WEAKENING A BIT WITH LARGE SCALE FLOW BECOMING INCREASINGLY ANTICYCLONIC FROM THE NORTH AND WEST AS SFC RDG BEGINS TO BUILD IN FROM THE NRN PLAINS AND ONTARIO. LAKE EFFECT SNOW WILL TAPER OFF QUICKLY FM THE WEST FRI AFTERNOON INTO FRI EVENING AS SFC RDG BUILDS ACROSS THE AREA AND 8H TEMPS WARM TO NEAR -12C. AN INCH OR TWO OF ADDITIONAL LES IS POSSIBLE OVER THE ERN COUNTIES FRI NIGHT IN A LAND BREEZE ENHANCED CONVERGENT NW WIND FLOW. PARTIAL CLEARING OVER THE WRN INTERIOR ALONG WITH LIGHT WINDS UNDER SFC RDG SHOULD ALLOW TEMPS TO DIP INTO AT LEAST THE SINGLE DIGITS BLO ZERO FRI EVENING. SOME INCREASE IN CLOUDS AND MAYBE EVEN A DUSTING OF LIGHT SNOW IS POSSIBLE OVER THE WEST LATE FRI NIGHT AS THE NEXT CLIPPER SYSTEM DIVES THROUGH THE NRN PLAINS. SATURDAY AND SUNDAY...MODELS SHOW THE NEXT CLIPPER SYSTEM DIVING DOWN THROUGH NRN MANITOBA AND NRN ONTARIO LATE SATURDAY AND SAT NIGHT. IT/S QUESTIONABLE WHETHER INCREASING WEST WINDS AHEAD OF THIS SYSTEM WILL GENERATE ANY LIGHT LES OVER THE KEWEENAW ON SAT AS 8H TEMPS NEAR -12C MAY NOT BE COLD ENOUGH FOR SUFFICIENT OVER WATER INSTABILITY. AS CLIPPER AND ASSOC SFC LOW MOVE NEAR JAMES BAY BY 12Z SUN...MODELS SHOW LIGHT SYSTEM SNOW SPREADING INTO NRN AND ERN SECTIONS OF THE CWA LATE SUN NIGHT ALONG AND AHEAD OF ADVANCING COLD FRONT. A PERIOD OF LES IS LIKELY OVER THE NCNTRL AND ERN CWA ON SUNDAY WITH CAA NW FLOW IN WAKE OF COLD FRONT. SUNDAY NIGHT INTO TUESDAY...ECMWF AND GFS IN DECENT AGREEMENT SHOWING A SERIES OF CLIPPER SHORTWAVES MOVING THROUGH FOR THE SUN NIGHT INTO MON NIGHT TIME FRAME. THESE SHORTWAVES WILL BRING CHCS FOR MORE LIGHT SYSTEM SNOW SUN NIGHT AND MONDAY WHILE USHERING IN A MUCH COLDER AIRMASS FOR MONDAY NIGHT INTO TUESDAY AS THE ECMWF INDICATES 8H TEMPS DROPPING TO NEAR -25C BY TUESDAY. EXPECT ANOTHER ROUND OF LAKE EFFECT SNOW AND BLOWING SNOW MON NIGHT INTO TUESDAY FOR N-NE LAKE SUPERIOR SNOWBELTS. INCREASINGLY COLDER AIRMASS WILL RESULT IN FINE SNOWFLAKES BY TUESDAY AS THE DGZ GETS SQUASHED NEAR THE LAKE SFC. THE FINE SNOWFLAKES WILL BE EFFECTIVE AT LOWERING VSBY IN BLOWING SNOW. IT APPEARS THAT A SERIES OF CLIPPER SHORTWAVES WILL CONTINUE TO REINFORCE ARCTIC AIRMASS THROUGH MUCH OF THE WORK WEEK KEEPING TEMPS WELL BELOW NORMAL FROM TUE THROUGH AT LEAST THU WITH LIGHT TO MODERATE LAKE EFFECT SNOW CONTINUING FOR THE NORTH WIND LAKE SUPERIOR SNOWBELTS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 646 AM EST WED JAN 15 2014 A HIGH PRESSURE RIDGE WILL QUICKLY MOVE EAST OVER UPPER MICHIGAN TODAY. DRIER AIR AND BACKING WINDS SHOULD DIMINISH THE LAKE EFFECT FROM WEST TO EAST TODAY AND TREND CONDITIONS TO VFR. A CLIPPER SYSTEM QUICKLY DIVING SOUTHEAST TOWARDS UPPER MICHIGAN TONIGHT WILL PUSH A BAND OF LIGHT TO MODERATE SNOW ACROSS THE AREA. THIS SNOW...COMBINED WITH GUSTY SOUTHWEST WINDS...WILL LEAD TO IFR VISIBILITIES AT KCMX/KIWD FOR A COUPLE HOUR PERIOD THIS EVENING INTO THE EARLY OVERNIGHT HOURS. THE SNOW WILL BE A LITTLE LATER TO ARRIVE AT KSAW AND THERE IS SOME CONCERN OF A WEAKENING TREND AS IT REACHES THE SITE. THUS...HAVE KEPT VISIBILITY AT LOW END MVFR FOR NOW. BEHIND THIS INITIAL WAVE OF SNOW...EXPECT SCATTERED SNOW SHOWERS AND MVFR CEILINGS ARE EXPECTED OVER UPPER MICHIGAN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 453 AM EST WED JAN 15 2014 A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35 KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD. SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST GALES TO 35KTS. HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT. WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ006. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ248>251-265>267. GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR LSZ266-267. HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162- 263-264. HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ244-245-263-264. GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR LSZ263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...VOSS AVIATION...SRF MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
543 AM EST WED JAN 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 453 AM EST WED JAN 15 2014 THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES. WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL 15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING. FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT. THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW DIMINISHES. OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS. AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER TEENS. 12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15 OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS (20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO THINK THAT IS ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT HOURS...THE SOCIETAL IMPACT WILL BE LIMITED AND THUS WILL ISSUE A AN SPS LATER THIS MORNING WITH INFO FOR THURSDAY INTO FRIDAY TOO. ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 542 AM EST WED JAN 15 2014 LARGE SCALE PATTERN THROUGH THE EXTENDED CONSISTS OF A MEAN RIDGE OVER WRN NORTH AMERICA WHILE A TROUGH DOMINATES DOMINATES MUCH OF ERN NORTH AMERICA...INCLUDING THE GREAT LAKES. STRONGEST CLIPPER SHORTWAVE MOVING THROUGH THE TROUGH CROSSES THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH EARLY FRIDAY. DAYTIME HIGHS WILL END UP SLIGHTLY BLO NORMAL FOR MUCH OF THE TIME. ONE OF THE WARMEST DAYS OF THE EXTENDED WILL BE ON THURSDAY AHEAD OF STRONGER COLD FRONT ASSOC WITH INITIAL CLIPPER SHORTWAVE. BRIEF WARMING MAY OCCUR NEXT MONDAY ONLY TO BE FOLLOWED BY ANOTHER CLIPPER SHORTWAVE AND BLAST OF ARCTIC AIR ON TUESDAY. THURSDAY AND FRIDAY...SYSTEM SNOW WILL GENERALLY BE TAPERING OFF THU MORNING AS THE BEST WAA/ISENTROPIC LIFT BEGINS TO SHIFT EAST. ALSO LAKE ENHANCED SNOW OVER THE ERN COUNTIES SHOULD BE TAPERING OFF BY LATE THU MORNING AS OVERWATER INSTABILITY WEAKENS WITH WARMER TEMPS -7C TEMPS MOVING OVER NRN LAKE MI. MODELS DIFFER ON EVOLUTION/TRACK OF SFC LOW MOVING THROUGH THE CWA THU INTO THU NIGHT. THE GFS AND ECMWF ARE DEEPER INITIALLY WITH THE SFC LOW THAN EITHER THE NAM/GEM-NH OR UKMET. THE GFS/NAM AND UKMET TRACK THE SFC LOW ACROSS UPPER MI ON THU WHILE THE ECMWF AND GEM-NH TAKE THE LOW JUST SOUTH OF THE WI BDR. ALL MODELS NOW APPEAR TO SHOW THE LOW FILLING AS IT TRACKS ACROSS THE UPPER GREAT LAKES ON THU AND THEN EAST OF THE REGION FRI INTO FRI NIGHT. IT ALSO APPEARS THAT ALL THE MODELS ARE TRENDING FARTHER WEST WITH HEART OF COLDEST 8H TEMPS (-20C OR COLDER) MOVING THROUGH THE NRN AND CENTRAL PLAINS INSTEAD OF THE UPPER GREAT LAKES REGION. THE COMBINATION OF THE WEAKENING SFC LOW AND WEAKER OVERWATER INSTABILITY WITH FCST 8H TEMPS OF -15 TO 18C WILL LIKELY RESULT IN LESS LAKE EFFECT SNOW AND BLOWING SNOW BEHIND THE SYSTEM THAN ORIGINALLY THOUGHT. HOWEVER...THERE WILL STILL BE A GOOD CHANCE FOR ADVISORY CRITERIA LAKE EFFECT SNOWFALL OVER THE WRN CWA THU AFTERNOON INTO FRI MORNING...AND OVER THE NCNTRL COUNTIES LATE THU NIGHT INTO FRIDAY WHEN THESE COLDER TEMPS SPREAD FROM WEST TO EAST ACROSS LAKE SUPERIOR IN THE WAKE OF THE FRONTAL PASSAGE IN A CYCLONIC CONVERGENT NRLY FLOW. A PERIOD OF GUSTY NRLY WINDS TO PERHAPS TO 30 MPH IS STILL POSSIBLE...ESPECIALLY ALONG LAKE SUPERIOR...WHICH COULD ALSO CAUSE CONSIDERABLE BLOWING AND DRIFTING OF SNOW ALONG WITH LOWERED VSBY. LEANING TOWARD ISSUING A SPS TO HIGHLIGHT THE POTENTIAL FOR MODERATE LES AND BLOWING SNOW FOR WEST AND NCNTRL COUNTIES THU AFTERNOON INTO FRI MORNING. BY THE TIME THE COLDEST 8H TEMPS REACH INTO THE ERN HALF OF THE LAKE LATE FRI MORNING...THE NRLY FLOW WILL BE WEAKENING A BIT WITH LARGE SCALE FLOW BECOMING INCREASINGLY ANTICYCLONIC FROM THE NORTH AND WEST AS SFC RDG BEGINS TO BUILD IN FROM THE NRN PLAINS AND ONTARIO. LAKE EFFECT SNOW WILL TAPER OFF QUICKLY FM THE WEST FRI AFTERNOON INTO FRI EVENING AS SFC RDG BUILDS ACROSS THE AREA AND 8H TEMPS WARM TO NEAR -12C. AN INCH OR TWO OF ADDITIONAL LES IS POSSIBLE OVER THE ERN COUNTIES FRI NIGHT IN A LAND BREEZE ENHANCED CONVERGENT NW WIND FLOW. PARTIAL CLEARING OVER THE WRN INTERIOR ALONG WITH LIGHT WINDS UNDER SFC RDG SHOULD ALLOW TEMPS TO DIP INTO AT LEAST THE SINGLE DIGITS BLO ZERO FRI EVENING. SOME INCREASE IN CLOUDS AND MAYBE EVEN A DUSTING OF LIGHT SNOW IS POSSIBLE OVER THE WEST LATE FRI NIGHT AS THE NEXT CLIPPER SYSTEM DIVES THROUGH THE NRN PLAINS. SATURDAY AND SUNDAY...MODELS SHOW THE NEXT CLIPPER SYSTEM DIVING DOWN THROUGH NRN MANITOBA AND NRN ONTARIO LATE SATURDAY AND SAT NIGHT. IT/S QUESTIONABLE WHETHER INCREASING WEST WINDS AHEAD OF THIS SYSTEM WILL GENERATE ANY LIGHT LES OVER THE KEWEENAW ON SAT AS 8H TEMPS NEAR -12C MAY NOT BE COLD ENOUGH FOR SUFFICIENT OVER WATER INSTABILITY. AS CLIPPER AND ASSOC SFC LOW MOVE NEAR JAMES BAY BY 12Z SUN...MODELS SHOW LIGHT SYSTEM SNOW SPREADING INTO NRN AND ERN SECTIONS OF THE CWA LATE SUN NIGHT ALONG AND AHEAD OF ADVANCING COLD FRONT. A PERIOD OF LES IS LIKELY OVER THE NCNTRL AND ERN CWA ON SUNDAY WITH CAA NW FLOW IN WAKE OF COLD FRONT. SUNDAY NIGHT INTO TUESDAY...ECMWF AND GFS IN DECENT AGREEMENT SHOWING A SERIES OF CLIPPER SHORTWAVES MOVING THROUGH FOR THE SUN NIGHT INTO MON NIGHT TIME FRAME. THESE SHORTWAVES WILL BRING CHCS FOR MORE LIGHT SYSTEM SNOW SUN NIGHT AND MONDAY WHILE USHERING IN A MUCH COLDER AIRMASS FOR MONDAY NIGHT INTO TUESDAY AS THE ECMWF INDICATES 8H TEMPS DROPPING TO NEAR -25C BY TUESDAY. EXPECT ANOTHER ROUND OF LAKE EFFECT SNOW AND BLOWING SNOW MON NIGHT INTO TUESDAY FOR N-NE LAKE SUPERIOR SNOWBELTS. INCREASINGLY COLDER AIRMASS WILL RESULT IN FINE SNOWFLAKES BY TUESDAY AS THE DGZ GETS SQUASHED NEAR THE LAKE SFC. THE FINE SNOWFLAKES WILL BE EFFECTIVE AT LOWERING VSBY IN BLOWING SNOW. IT APPEARS THAT A SERIES OF CLIPPER SHORTWAVES WILL CONTINUE TO REINFORCE ARCTIC AIRMASS THROUGH MUCH OF THE WORK WEEK KEEPING TEMPS WELL BELOW NORMAL FROM TUE THROUGH AT LEAST THU WITH LIGHT TO MODERATE LAKE EFFECT SNOW CONTINUING FOR THE NORTH WIND LAKE SUPERIOR SNOWBELTS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1151 PM EST TUE JAN 14 2014 LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON. NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT SNOW BREAKING OUT IN THE EVENING AT ALL SITES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 453 AM EST WED JAN 15 2014 A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35 KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD. SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST GALES TO 35KTS. HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT. WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ006. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ248>251-265>267. GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR LSZ266-267. HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162- 263-264. HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ244-245-263-264. GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR LSZ263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...VOSS AVIATION...07 MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
540 AM EST WED JAN 15 2014 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 453 AM EST WED JAN 15 2014 THE CLIPPER SYSTEM THAT BROUGHT THE SNOW TO THE SOUTH CENTRAL CWA YESTERDAY CONTINUES TO PULL OUT OF THE REGION EARLY THIS MORNING AND IS CURRENTLY OVER NORTHERN LAKE HURON AT 1002MB. MEANWHILE...A HIGH PRESSURE RIDGE OF 1024MB OVER THE EASTERN DAKOTAS IS BEGINNING TO SHIFT INTO WESTERN MINNESOTA. THE TIGHT GRADIENT BETWEEN THESE TWO FEATURES AND RAP ANALYZED 850MB TEMPS OF -16C HAS LED TO LAKE EFFECT SNOW OVER MOST OF THE NORTHERLY WIND FAVORED AREAS NEAR LAKE SUPERIOR. THE STRONGEST LAKE EFFECT HAS BEEN OVER FAR EASTERN MARQUETTE COUNTY AND WESTERN ALGER COUNTY...WHERE THERE HAS BEEN INCREASED CONVERGENCE FROM THE DEPARTING SYSTEM AND GRADUALLY BACKING WINDS. WITH THE STRONGER WINDS OF 27KTS AT STDM4...THESE BANDS HAVE BEEN EASILY REACHING SOUTHERN DELTA/SCHOOLCRAFT COUNTIES. WITH THE QUICK DEPARTURE OF THE LOW AND THE ARRIVAL OF THE RIDGE...SHOULD SEE A VERY QUICK BACKING TREND TO THE WINDS OVER THE WESTERN LAKE TODAY AND ALLOW THE REMAINING LAKE EFFECT TO PUSH NORTHEAST ACROSS THE KEWEENAW PENINSULA AND OUT OVER THE OPEN LAKE BY 21Z. OVER THE EAST HALF...THE BACKING WINDS WILL TAKE A LITTLE BIT LONGER TO ARRIVE...BUT HAVE ALREADY STARTED TO SEE THEM BACK TO THE NORTHWEST AT STANNARD ROCK AND GRANITE ISLAND. THUS...EXPECT THE FOCUSED LAKE EFFECT OVER EASTERN MARQUETTE AND WESTERN ALGER COUNTY TO CONTINUE TO AROUND OR SHORTLY BEFORE DAYBREAK AND THEN THE INFLUENCE OF THE BACKING WINDS WILL TAKE HOLD AND STEADILY SHIFT THE BANDS EASTWARD ACROSS ALGER COUNTY THROUGH THE DAY. 925MB WINDS LOOK TO BE WEST OR WEST-SOUTHWEST AROUND 21Z AND SHOULD SEE THE LAST OF THE SNOW SHOWERS MOVING AWAY FROM GRAND MARAIS AT OR SHORTLY AFTER THAT TIME. WITH GUSTS TO 25-30KTS RIGHT ALONG THE LAKE SUPERIOR SHORELINE...OPTED TO EXTEND THE ADVISORY FOR ANOTHER 3HRS (UNTIL 15Z) SINCE CONDITIONS ALONG M-28 WILL LIKELY BE POOR THIS MORNING. FELT 15Z WAS A REASONABLE ENDING TIME SINCE THE WINDS WILL BE DIMINISHING AND THE BANDS STARTING TO PUSH EAST. WILL ALSO ISSUE AN SPS FOR EASTERN MARQUETTE COUNTY SHORTLY TO COVER M-28 EAST OF HARVEY WITH THE BLOWING SNOW AND LAKE EFFECT. THE NEXT CLIPPER SYSTEM TO AFFECT THE AREA IS CURRENTLY DROPPING SOUTHEAST THROUGH SASKATCHEWAN AT THIS TIME AND WILL QUICKLY MOVE SOUTHEAST THROUGH CANADA TODAY. THE INITIAL PUSH OF THE SHORTWAVE WILL ARRIVE FROM WEST TO EAST THIS EVENING AND INTO THE OVERNIGHT HOURS AND BRING THE FIRST WAVE OF SNOW WITH THIS SYSTEM. MODELS CONTINUE TO VARY ON THE HANDLING OF THE LOW FOR THURSDAY...BUT THE GENERAL IDEA OF THE LOW WILL BE LAGGING BEHIND AND MOVING OVER WESTERN LAKE SUPERIOR AROUND 12Z THURSDAY SEEMS REASONABLE. THE FIRST PUSH OF SNOW WILL BE ASSOCIATED WITH THE MAIN SHORTWAVE ENERGY MOVING OVER THE WESTERN HALF OF THE CWA DURING THE EVENING AND BECOMING A LITTLE MORE DIFFUSE AS IT MOVES OVER THE EASTERN CWA. IN ADDITION TO THE SHORTWAVE...THERE IS A NARROW CORRIDOR OF DEEP MOISTURE...850-500MB Q-VECTOR CONVERGENCE AND WARM AIR ADVECTION...AND ISENTROPIC ASCENT ON THE 275-295K SURFACES. THIS WOULD SUPPORT A NICE BAND OF LIGHT TO BRIEFLY MODERATE SNOW MOVING ACROSS THE WESTERN CWA...BUT DUE TO THE NARROW AND QUICK MOVEMENT OF THE FEATURES IT SHOULD ONLY LEAD TO A 3-4HR PERIOD OF SNOW AS IT MOVES THROUGH. IN ADDITION...THE LATEST FORCING IN THE MODELS SEEMS TO BE A LITTLE MORE SOUTHWEST AND FOCUSED NEAR GOGEBIC/IRON COUNTIES BEFORE WEAKENING. RATIOS ARE TRICKY AS THE CLOUD LAYER IS INITIALLY IN THE DGZ...BUT THEN MOVES TO THE BOTTOM OR BELOW AS THE WARM AIR ADVECTION TAKES HOLD. IN ADDITION...THE STRONG WINDS IN AND BELOW THE CLOUD LAYER MAY PRODUCE SOME FRACTURING AND LIMITING RATIOS SOMEWHAT. OPTED TO GO HIGHER INITIALLY (16-18 TO 1) AND THEN DROP TOWARDS 13 TO 1 AS THE WARM AIR SURGES IN AND THE SNOW DIMINISHES. OVER THE EAST...THAT AREA OF SNOW WILL SHOULD ARRIVE AROUND MIDNIGHT...BUT THINK IT WILL BE ON A LITTLE BIT OF A DIMINISHING TREND SINCE THE MODELS ARE SHOWING THE SHORTWAVE AND WAA BECOMING WEAKER. ONE ITEM THAT COULD COUNTERACT SOME OF THIS WEAKENING IDEA IS LAKE ENHANCEMENT OFF LAKE MICHIGAN WITH THE SOUTHWESTERLY WINDS. AT LEAST INITIALLY...THERE IS SOME QUESTION IN HOW MUCH LOW LEVEL MOISTURE WILL BE PRESENT DURING THE FIRST PART OF THE EVENING DUE TO THE HIGH PRESSURE RIDGE. WOULD THINK THERE WOULD BE AT LEAST SOME CLOUDS OR LIGHT SNOW SHOWERS SOUTHEAST OF A LINE FROM KISQ-KERY BEFORE THE BETTER MOISTURE ARRIVES AND WINDS TURN A LITTLE MORE SOUTH-SOUTHWESTERLY AND FOCUS THE LAKE ENHANCEMENT MORE INTO THE CWA AROUND MIDNIGHT AND THROUGH MUCH OF THE REST OF THE NIGHT. 875MB TEMPS STAY AROUND -14C FOR MUCH OF THE NIGHT...SO THERE IS DECENT DELTA-T VALUES. DO HAVE A COUPLE CONCERNS ON HIGHER AMOUNTS AND IT LARGELY HAS TO DO WITH THE SNOW RATIOS. FIRST...MUCH OF THE CLOUD IS AT THE LOW END OF THE DGZ. SECOND...WITH THE STRONG WINDS IN THE CLOUD LAYER...WOULD EXPECT THE DENDRITES THAT DO DEVELOP TO FRACTURE ON THEIR WAY DOWN. BOTH OF THESE SHOULD LEAD TO RATIOS IN THE UPPER TEENS. 12HR QPF FOR TONIGHT FROM THE MODELS IS GENERALLY BETWEEN 0.07-0.15 OF AN INCH FOR MUCH OF THE CWA AND USED A GENERAL MIDDLE GROUND FOR THE FORECAST. THIS LEADS TO SNOWFALL AMOUNTS BETWEEN 1-2 INCHES TONIGHT. DO HAVE SLIGHTLY HIGHER AMOUNTS OVER THE FAR EAST WHERE THE LAKE ENHANCEMENT SHOULD PUSH AMOUNTS BETWEEN 2-3 INCHES. IN ADDITION TO THE SNOW...THERE WILL BE GUSTY SOUTHWEST WINDS (20-30MPH) THAT PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW AND MAY HELP REDUCE VISIBILITIES BELOW A MILE AS THE INITIAL SNOW MOVES THROUGH. ALTHOUGH THE SNOW IS SUB ADVISORY...THE WIND PUSHES THE CONCERN UP SOME FOR THAT SHORT PERIOD WHEN THE SNOW OCCURS. BUT SINCE IT WILL ONLY BE A FEW HOUR PERIOD OF SNOW...DO THINK THAT IS ENOUGH TO WARRENT AN ADVISORY. IN ADDITION...WITH IT OCCURRING DURING THE LATTER PART OF THE EVENING AND THROUGH THE OVERNIGHT HOURS...THE SOCIETAL IMPACT WILL BE LIMITED AND THUS WILL ISSUE A AN SPS LATER THIS MORNING WITH INFO FOR THURSDAY INTO FRIDAY TOO. ONCE THAT INITIAL WAVE OF PRECIP MOVES THROUGH...LOOKS LIKE THERE WILL BE A MID LEVEL DRY SLOT THAT DIMINISHES OR ENDS THE SNOW FOR A PERIOD BEFORE THE NEXT SHORTWAVE AND DEEPER MOISTURE WITH THE LOW ARRIVES AFTER 09Z OVER THE WEST. THUS...HAVE CUT POPS BACK TO JUST CHANCE WORDING OVER THE WEST AND MINIMAL ADDITIONAL ACCUMULATION. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 540 AM EST WED JAN 15 2014 LARGE SCALE PATTERN THROUGH THE EXTENDED CONSISTS OF A MEAN RIDGE OVER WRN NORTH AMERICA WHILE A TROUGH DOMINATES DOMINATES MUCH OF ERN NORTH AMERICA...INCLUDING THE GREAT LAKES. STRONGEST CLIPPER SHORTWAVE MOVING THROUGH THE TROUGH CROSSES THE UPPER GREAT LAKES WEDNESDAY NIGHT THROUGH EARLY FRIDAY. DAYTIME HIGHS WILL END UP SLIGHTLY BLO NORMAL FOR MUCH OF THE TIME. ONE OF THE WARMEST DAYS OF THE EXTENDED WILL BE ON THURSDAY AHEAD OF STRONGER COLD FRONT ASSOC WITH INITIAL CLIPPER SHORTWAVE. BRIEF WARMING MAY OCCUR NEXT MONDAY ONLY TO BE FOLLOWED BY ANOTHER CLIPPER SHORTWAVE AND BLAST OF ARCTIC AIR ON TUESDAY. THURSDAY AND FRIDAY...SYSTEM SNOW WILL GENERALLY BE TAPERING OFF THU MORNING AS THE BEST WAA/ISENTROPIC LIFT BEGINS TO SHIFT EAST. ALSO LAKE ENHANCED SNOW OVER THE ERN COUNTIES SHOULD BE TAPERING OFF BY LATE THU MORNING AS OVERWATER INSTABILITY WEAKENS WITH WARMER TEMPS -7C TEMPS MOVING OVER NRN LAKE MI. MODELS DIFFER ON EVOLUTION/TRACK OF SFC LOW MOVING THROUGH THE CWA THU INTO THU NIGHT. THE GFS AND ECMWF ARE DEEPER INITIALLY WITH THE SFC LOW THAN EITHER THE NAM/GEM-NH OR UKMET. THE GFS/NAM AND UKMET TRACK THE SFC LOW ACROSS UPPER MI ON THU WHILE THE ECMWF AND GEM-NH TAKE THE LOW JUST SOUTH OF THE WI BDR. ALL MODELS NOW APPEAR TO SHOW THE LOW FILLING AS IT TRACKS ACROSS THE UPPER GREAT LAKES ON THU AND THEN EAST OF THE REGION FRI INTO FRI NIGHT. IT ALSO APPEARS THAT ALL THE MODELS ARE TRENDING FARTHER WEST WITH HEART OF COLDEST 8H TEMPS (-20C OR COLDER) MOVING THROUGH THE NRN AND CENTRAL PLAINS INSTEAD OF THE UPPER GREAT LAKES REGION. THE COMBINATION OF THE WEAKENING SFC LOW AND WEAKER OVERWATER INSTABILITY WITH FCST 8H TEMPS OF -15 TO 18C WILL LIKELY RESULT IN LESS LAKE EFFECT SNOW AND BLOWING SNOW BEHIND THE SYSTEM THAN ORIGINALLY THOUGHT. HOWEVER...THERE WILL STILL BE A GOOD CHANCE FOR ADVISORY CRITERIA LAKE EFFECT SNOWFALL OVER THE WRN CWA THU AFTERNOON INTO FRI MORNING...AND OVER THE NCNTRL COUNTIES LATE THU NIGHT INTO FRIDAY WHEN THESE COLDER TEMPS SPREAD FROM WEST TO EAST ACROSS LAKE SUPERIOR IN THE WAKE OF THE FRONTAL PASSAGE IN A CYCLONIC CONVERGENT NRLY FLOW. A PERIOD OF GUSTY NRLY WINDS TO PERHAPS TO 30 MPH IS STILL POSSIBLE...ESPECIALLY ALONG LAKE SUPERIOR...WHICH COULD ALSO CAUSE CONSIDERABLE BLOWING AND DRIFTING OF SNOW ALONG WITH LOWERED VSBY. LEANING TOWARD ISSUING A SPS TO HIGHLIGHT THE POTENTIAL FOR MODERATE LES AND BLOWING SNOW FOR WEST AND NCNTRL COUNTIES THU AFTERNOON INTO FRI MORNING. BY THE TIME THE COLDEST 8H TEMPS REACH INTO THE ERN HALF OF THE LAKE LATE FRI MORNING...THE NRLY FLOW WILL BE WEAKENING A BIT WITH LARGE SCALE FLOW BECOMING INCREASINGLY ANTICYCLONIC FROM THE NORTH AND WEST AS SFC RDG BEGINS TO BUILD IN FROM THE NRN PLAINS AND ONTARIO. LAKE EFFECT SNOW WILL TAPER OFF QUICKLY FM THE WEST FRI AFTERNOON INTO FRI EVENING AS SFC RDG BUILDS ACROSS THE AREA AND 8H TEMPS WARM TO NEAR -12C. AN INCH OR TWO OF ADDITIONAL LES IS POSSIBLE OVER THE ERN COUNTIES FRI NIGHT IN A LAND BREEZE ENHANCED CONVERGENT NW WIND FLOW. PARTIAL CLEARING OVER THE WRN INTERIOR ALONG WITH LIGHT WINDS UNDER SFC RDG SHOULD ALLOW TEMPS TO DIP INTO AT LEAST THE SINGLE DIGITS BLO ZERO FRI EVENING. SOME INCREASE IN CLOUDS AND MAYBE EVEN A DUSTING OF LIGHT SNOW IS POSSIBLE OVER THE WEST LATE FRI NIGHT AS THE NEXT CLIPPER SYSTEM DIVES THROUGH THE NRN PLAINS. SATURDAY AND SUNDAY...MODELS SHOW THE NEXT CLIPPER SYSTEM DIVING DOWN THROUGH NRN MANITOBA AND NRN ONTARIO LATE SATURDAY AND SAT NIGHT. IT/S QUESTIONABLE WHETHER INCREASING WEST WINDS AHEAD OF THIS SYSTEM WILL GENERATE ANY LIGHT LES OVER THE KEWEENAW ON SAT AS 8H TEMPS NEAR -12C MAY NOT BE COLD ENOUGH FOR SUFFICIENT OVER WATER INSTABILITY. AS CLIPPER AND ASSOC SFC LOW MOVE NEAR JAMES BAY BY 12Z SUN...MODELS SHOW LIGHT SYSTEM SNOW SPREADING INTO NRN AND ERN SECTIONS OF THE CWA LATE SUN NIGHT ALONG AND AHEAD OF ADVANCING COLD FRONT. A PERIOD OF LES IS LIKELY OVER THE NCNTRL AND ERN CWA ON SUNDAY WITH CAA NW FLOW IN WAKE OF COLD FRONT. SUNDAY NIGHT INTO TUESDAY...ECMWF AND GFS IN DECENT AGREEMENT SHOWING A SERIES OF CLIPPER SHORTWAVES MOVING THROUGH FOR THE SUN NIGHT INTO MON NIGHT TIME FRAME. THESE SHORTWAVES WILL BRING CHCS FOR MORE LIGHT SYSTEM SNOW SUN NIGHT AND MONDAY WHILE USHERING IN A MUCH COLDER AIRMASS FOR MONDAY NIGHT INTO TUESDAY AS THE ECMWF INDICATES 8H TEMPS DROPPING TO NEAR -25C BY TUESDAY. EXPECT ANOTHER ROUND OF LAKE EFFECT SNOW AND BLOWING SNOW MON NIGHT INTO TUESDAY FOR N-NE LAKE SUPERIOR SNOWBELTS. INCREASINGLY COLDER AIRMASS WILL RESULT IN FINE SNOWFLAKES BY TUESDAY AS THE DGZ GETS SQUASHED NEAR THE LAKE SFC. THE FINE SNOWFLAKES WILL BE EFFECTIVE AT LOWERING VSBY IN BLOWING SNOW. BELOW NORMAL TEMPS. IT APPEARS THAT A SERIES OF CLIPPER SHORTWAVES WILL CONTINUE TO REINFORCE ARCTIC AIRMASS THROUGH MUCH OF THE WORK WEEK KEEPING TEMPS WELL BELOW NORMAL FROM TUE THROUGH AT LEAST THU WITH LIGHT TO MODERATE LAKE EFFECT SNOW CONTINUING FOR THE NORTH WIND LAKE SUPERIOR SNOWBELTS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1151 PM EST TUE JAN 14 2014 LAKE EFFECT SNOW SHOWERS WILL CONTINUE THROUGH THE MORNING AT ALL SITES WITH MVFR CONDITIONS AT ALL SITES THROUGH MID MORNING. ONLY EXCEPTION WILL BRIEFLY BE AT SAW EARLY THIS MORNING AS A STRONGER LAKE EFFECT SNOW BAND SLOWLY MOVES EAST OF THE AREA AND IN THIS BAND WILL BE IFR CONDITIONS. AS WINDS BACK TO THE SW...LAKE EFFECT WILL END AND CONDITIONS WILL GO TO VFR AT ALL SITES IN THE AFTERNOON. NEXT DISTURBANCE ARRIVES BY EVENING WITH MVFR CONDITIONS AND LIGHT SNOW BREAKING OUT IN THE EVENING AT ALL SITES. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 453 AM EST WED JAN 15 2014 A LOW CENTERED OVER CENTRAL LAKE HURON WILL DEPART THE GREAT LAKES REGION TODAY...ALLOWING A HIGH PRESSURE RIDGE TO QUICKLY SLIDE OVER LAKE SUPERIOR. THIS WILL LEAD TO WEAKENING WINDS THIS MORNING...WHICH WILL THEN QUICKLY BACK TO THE SOUTHWEST AND INCREASE THIS AFTERNOON AND EVENING AHEAD OF ANOTHER CLIPPER SYSTEM. THINK THE SUSTAINED WINDS WILL BE IN THE 25-30KT RANGE OVER THE WESTERN LAKE THIS EVENING WITH FREQUENT ENOUGH GUSTS TO 35 KNOTS TO SUPPORT ISSUING A GALE WARNING FOR ABOUT A 6-9HR PERIOD. SINCE THE LOW WILL BE WEAKENING AS IT MOVES TOWARDS LAKE SUPERIOR...AM A LITTLE UNCERTAIN ON HOW STRONG THE WINDS WILL BE OVER THE EASTERN LAKE...BUT SHOULD SUPPORT AT LEAST SOME GALE FORCE GUSTS TO 35KTS. THIS LOW WILL MOVE OVER WESTERN LAKE SUEPRIOR OVERNIGHT AND DECREASE WINDS ACROSS THE LAKE. AS IT MOVES ACROSS UPPER MICHIGAN ON THURSDAY AND SLOWLY WEAKENS...WINDS WILL TURN TO THE NORTH FROM WEST TO EAST THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. THERE IS THE POTENTIAL FOR SOME GALES TO 35KTS ON THE BACK SIDE OF THIS LOW...ESPECIALLY OVER WESTERN LAKE SUPERIOR WHEN THE LOW IS STILL A LITTLE STRONGER. THIS LOW WILL DEPART THE AREA ON FRIDAY AND ALLOW A WEAK HIGH PRESSURE RIDGE TO SLIDE ACROSS THE LAKE FRIDAY AFTERNOON AND FRIDAY NIGHT. A COUPLE OTHER CLIPPER SYSTEMS WILL BE NEAR THE GREAT LAKES REGION THIS WEEKEND. THE STRONGEST ONE WILL MOVE THROUGH NORTHEAST ONTARIO ON SATURDAY NIGHT AND DRAG A COLD FRONT ACROSS LAKE SUPERIOR LATE SATURDAY NIGHT AND SUNDAY MORNING...WHICH WILL BRING ANOTHER POSSIBILITY OF NORTHWEST GALES TO 35KTS. HEAVY FREEZING SPRAY SHOULD DIMINISH THIS MORNING BUT THEN COME BACK LATE THIS AFTERNOON AND EVENING. DID ISSUES A HEAVY FREEZING SPRAY WARNING FOR THE WEST HALF OF THE LAKE TO ACCOUNT FOR THAT. WHEN THE WINDS TURN NORTHERLY THURSDAY NIGHT INTO FRIDAY...SHOULD SEE ANOTHER PERIOD OF HEAVY FREEZING SPRAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ006. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ248>251-265>267. GALE WARNING FROM 10 PM THIS EVENING TO 4 AM EST THURSDAY FOR LSZ266-267. HEAVY FREEZING SPRAY WARNING FROM 5 PM EST /4 PM CST/ THIS AFTERNOON TO 1 AM EST /MIDNIGHT CST/ THURSDAY FOR LSZ162- 263-264. HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ244-245-263-264. GALE WARNING FROM 7 PM THIS EVENING TO 1 AM EST THURSDAY FOR LSZ263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...VOSS AVIATION...07 MARINE...SRF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
402 PM EST WED JAN 15 2014 .SYNOPSIS... A SERIES OF CLIPPER SYSTEM WILL PROGRESS THROUGH THE REGION OVER THE NEXT SEVERAL DAYS. ONE WILL CROSS THE AREA TONIGHT...ONE TOMORROW NIGHT AND FRIDAY...ANOTHER SATURDAY INTO SUNDAY. AFTER A BRIEF PERIOD OF MORE TRANQUIL WEATHER...ANOTHER SYSTEM MOVES INTO THE AREA FROM THE NORTHWEST ON WEDNESDAY. && .NEAR TERM /THROUGH THURSDAY/... AS OF 330 PM EST WEDNESDAY... WATER VAPOR SATELLITE IMAGERY WAS SHOWING THE AXIS OF THE UPPER TROUGH SWINGING THROUGH THE LOWER MISSISSIPPI RIVER VALLEY. A JETLET ON THE EAST SIDE OF THE TROUGH WAS CURRENTLY PASSING ACROSS THE WESTERN HALF OF THE FORECAST AREA...AND HELPING TO BRIEFLY INTENSIFY THE STRENGTH OF THE PRECIPITATION ACROSS THE SOUTHWEST PARTS OF THE REGION. THE FOCUS FOR THE INCREASED ACTIVITY WILL TREND NORTHEAST ACROSS THE AREA IN RELATION TO TRACK OF THE JETLET...AND THE SUBTLE PUSH EASTWARD OF THE UPPER TROUGH. THE VAST MAJORITY OF THE SNOWFALL IN THE AREA OF THE WINTER WEATHER ADVISORIES IS OVER. ADDITIONAL LIGHT AMOUNTS UNDER AN INCH ARE EXPECTED ACROSS THE NORTHERN MOUNTAINS OF NORTH CAROLINA AND NEIGHBORING GRAYSON COUNTY VA. HERE A BRIEF AND RELATIVELY WEAK UPSLOPE COMPONENT WILL HELP MAINTAIN LIGHT SNOWFALL UNTIL THE AXIS OF THE UPPER TROUGH MOVES OVERHEAD OF THIS AREA AROUND MIDNIGHT TONIGHT. WILL KEEP THE ADVISORY GOING IN THIS AREA BECAUSE OF THIS...AND ALLOW SUBSEQUENT SHIFTS TO CANCEL IF NEED BE BASED UPON THE LATEST SATELLITE AND RADAR TRENDS. HOWEVER...WILL BRING THE END TIME OF THE TAZEWELL AND SMYTH COUNTY PART OF THE ADVISORY BACK TO 600 PM. THE HEAVIEST SNOW IS EXITING THIS REGION CURRENTLY...AND THIS REGION WILL NOT BENEFIT FROM ANY UPSLOPE COMPONENT THIS EVENING. THE REMAINDER OF THE AREA WILL EXPERIENCE EITHER LIGHT RAIN OR LIGHT SNOW OR A MIX OF THE TWO THROUGH THE EVENING AND EARLY THURSDAY MORNING AS THE UPPER TROUGH CONTINUES ITS PROGRESS EASTWARD. THE BEST CHANCE OF ACCUMULATING SNOW WILL BE ACROSS THE HIGHER TERRAIN FROM ROUGHLY FLOYD VA NORTH TO NEAR LEXINGTON VA. HERE AMOUNTS WILL APPROACH ONE INCH OF SNOW AT ELEVATIONS AT OR ABOVE ROUGHLY 2000 FEET MSL. ACROSS THE PIEDMONT...MOST AREAS WILL BE TOO MILD FOR ALL SNOW...BUT MORE LIKELY EXPERIENCE A MIX OF RAIN AND SNOW OR ALL RAIN...ESPECIALLY THOSE AREA OVER SOUTHSIDE VIRGINIA AND NEIGHBORING SECTIONS OF NORTH CENTRAL NORTH CAROLINA. ANY SNOWFALL WILL BE LIGHT...AND BE FIGHTING WITH THE RAIN TO ACCUMULATE. VERY LATE TONIGHT/EARLY THURSDAY MORNING...TEMPERATURES ARE EXPECTED TO BE COLD ENOUGH FOR ALL SNOW ACROSS EVEN THE FAR SOUTHEAST PART OF THE REGION. HOWEVER...BY THAT TIME...THE VAST MAJORITY OF THE MOISTURE WILL BE OUT OF THE AREA...ALLOWING FOR TRACE AMOUNTS AT BEST. LOWS TONIGHT WILL RANGE FROM THE UPPER TEENS TO LOWER 20S IN THE MOUNTAINS TO THE MID TO UPPER 20S ACROSS THE PIEDMONT. DURING THE DAY THURSDAY...THE AREA WILL BE BETWEEN SYSTEMS...THE DEPARTING UPPER TROUGH FROM TODAY...AND THE NEXT CLIPPER SYSTEM APPROACHING THE AREA OVER THE GREAT LAKES. WHILE WE EXPECT NO PRECIPITATION...AND MOSTLY CLEAR SKIES EARLY IN THE DAY...THERE WILL BE A TREND TOWARD INCREASING CLOUDS LATE IN THE DAY IN THE WEST IN ADVANCE OF THE APPROACHING CLIPPER. HIGHS ON FRIDAY WILL RANGE FROM THE LOW TO MID 30S ACROSS THE MOUNTAINS TO AROUND 40 TO THE MID 40S ACROSS THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... AS OF 330 PM EST WEDNESDAY... THE NORTHERN STREAM JET WILL REMAIN ACTIVE THROUGH THE UPCOMING WEEKEND WITH A LONG WAVE FULL LATITUDE UPPER LEVEL TROUGH OVER THE EASTERN CONUS AND A RIDGE ALONG THE WEST COAST. THIS PATTERN WILL SUBJECT OUR FORECAST AREA TO A CONTINENTAL POLAR AIRMASS WHICH WILL RESULT IN A DOWNWARD SPIRAL OF TEMPERATURES ACROSS THE MID ATLANTIC REGION FOR THE UPCOMING WEEKEND. COLDEST OF THE AIR...M14 TO M16 DEG C...IS FCST TO MOVE OVERHEAD SATURDAY...SURFACE TEMPERATURES STRUGGLING TO GET ABOVE FREEZING. THE MOUNTAINS WILL LIKELY REMAIN IN THE 20S ON SATURDAY WITH WIND CHILLS IN THE SINGLE DIGITS. PRECIPITATION THREAT THROUGH THE UPCOMING WEEKEND LOOKS TO BE MAINLY CONFINED TO THE MOUNTAINS. TWO CLIPPERS ARE FORECAST TO PASS ACROSS THE AREA. THE FIRST WILL MOVE ACROSS THE GREAT LAKES FRIDAY...THE SECOND SYSTEM TAKING A SIMILAR TRACK SATURDAY NIGHT. THE FIRST DISTURBANCE WILL BEGIN TO SPREAD CLOUDS OVER THE ARE THURSDAY NIGHT WITH MOUNTAIN SNOW SHOWERS DEVELOPING AS THE SYSTEM APPROACHES EARLY FRIDAY. CAN`T RULE OUT SOME LIGHT MIXED PRECIP EAST OF THE MOUNTAINS FRIDAY...BUT THINK THE ACCUMULATING SNOW WILL REMAIN PRIMARILY CONFINED TO THE MOUNTAINS WEST OF THE BLUE RIDGE WITH 1-3 INCHES POSSIBLE IN THE HIGH COUNTRY OF NC...THE MTNS OF FAR SOUTHWESTERN VA...AND THE MOUNTAINS OF SOUTHEAST WEST VIRGINIA. THE PASSAGE OF THE CLIPPER WILL BRING GUSTY NORTHWEST WINDS AND MUCH COLDER TEMPERATURES TO THE AREA FRIDAY NIGHT...MOUNTAIN SNOW SHOWERS AND FLURRIES CONTINUING WEST OF THE BLUE RIDGE. LOWS FRIDAY NIGHT ARE EXPECTED TO DIP INTO THE LOWER TEENS IN THE MOUNTAINS WITH WIND CHILLS NEAR ZERO. THE SECOND DISTURBANCE IS PROGGED TO COME QUICK ON THE HEELS OF FRIDAY NIGHTS WINTRY BLAST...WITH REPEAT THREAT FOR MOUNTAIN SNOW SHOWERS SATURDAY NIGHT OFFERING ANOTHER 1 TO 3 INCHES OF ACCUMULATION IN THE FAVORED HIGHLAND AREAS WHICH ARE PRONE TO THESE NORTHWEST FLOW SORT OF SYSTEMS. EAST OF THE BLUE RIDGE...SOME LIGHT PRECIP IS POSSIBLE...BUT THE DOWNSLOPE DRYING OF THE WIND TENDS TO ELIMINATE MUCH OF A CHANCE FOR SEEING ANYTHING MEASURABLE THERE. IN ORDER TO GET MEASURABLE PRECIP EAST OF THE BLUE RIDGE...THE SYSTEM WOULD NEED TO TRACK SOUTH OF THE AREA. ATTM IT LOOKS LIKE THE TRACK WILL BE TO OUR NORTH...TAKING THE CENTER OF THE DISTURBANCE ACROSS THE MASON DIXON. THIS SORT OF TRACK WOULD SUGGEST THE HEAVIER PRECIP THREAT WILL PASS WELL NORTH OF OUR AREA FROM PENNSYLVANIA INTO NEW ENGLAND. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 300 PM EST WEDNESDAY... CLIPPER LOW DARTS ACROSS THE OHIO VALLEY ON SUNDAY...LEAVING A GOOD BURST OF WIND AND SOME UPSLOPE SNOW SHOWERS ACROSS THE GREENBRIER VALLEY. STRONG DOWNSLOPE WNW FLOW WILL TAKE THE EDGE OFF THE COLD AIR AS IT CROSSES INTO THE ROANOKE VALLEY AND PIEDMONT. SOME 40KT GUSTS MAY BE POSSIBLE ACROSS NW NC INTO SUNDAY MORNING WHEN THE BOUNDARY CROSSES...AND POSSIBLY INTO WESTERN GREENBRIER AND BATH COUNTY. WAA AND WINDS REMAINING OVERNIGHT INTO MONDAY MEANS A WELL MIXED ATMOSPHERE AND MIN TEMPS POTENTIALLY SEVERAL DEGREES WARMER THAN GUIDANCE ESPECIALLY ALONG THE RIDGE TOPS. TEMPS SHOULD WARM EVEN MORE ON MONDAY AHEAD OF THE NEXT CLIPPER WITH MANY 50F MAX TEMPS POSSIBLE...HOWEVER THE GREENBRIER VALLEY WILL BE STUNTED SOMEWHAT BY LATE ARRIVING CLOUDS. MORE WARM...DRY AND BREEZY DAYS LIKE THIS AND SOME FIRE WX CONCERNS MAY BEGIN TO MOUNT. THE 12Z ECMWF IS FASTER AND MORE AGGRESSIVE WITH A LOW DEVELOPING ALONG THE NEXT ARCTIC FRONT SLATED FOR TUESDAY OR TUESDAY NIGHT...THAN THE 12Z GFS. THE ECMWF HAS BEEN UNCHARACTERISTICALLY SUBPAR SINCE ITS LATEST UPDATE...AND A LITTLE HESITANT TO TRUST IT OVER THE GFS ATTM. NONETHELESS...-20C H85 AIR MAY ARRIVE ACROSS THE GREENBRIER VALLEY BY NEXT WEDNESDAY BEHIND THE FRONT. UP FOR DEBATE IS HOW FAR SOUTH THE MAIN WAVE DIVES...WHICH HAS A LOT TO DUE WITH ANY DEVELOPMENT ALONG THE FRONT. REGARDLESS THERE STILL WILL BE AN UPSLOPE SNOW EVENT TUESDAY NIGHT INTO WEDNESDAY. IF THE FRONT IS SLOWER...WHICH IS USUALLY THE CASE THIS DEEP INTO THE FORECAST...THEN TUESDAY COULD STILL BE ANOTHER WARM DAY FOR ALL AREAS OUTSIDE OF SE WEST VA. HEART OF THE COLDEST AIR IN PLACE WEDNESDAY AND WEDNESDAY NIGHT. HIGHS POTENTIALLY IN THE TEENS ON WEDNESDAY ACROSS SE WEST VA. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... AS OF 1245 PM EST WEDNESDAY... WILL LEAN ON LOCAL WRF AND HRRR MESO MODEL RUNS FOR TIMING OF CIGS/WX. BAND OF SNOW ASSOCIATED WITH WEAK FRONT EXTENDING DOWN FROM CLIPPER IN THE GREAT LAKES HAS BEEN MAKING VERY SLOW PROGRESS EWD AND EXPECTING IT TO BREAK UP IN DOWNSLOPE EAST OF THE BLUE RIDGE AND PERHAPS REGAIN SOME VIGOR AS IT INTERACTS WITH DEVELOPING LOW PRESSURE TO THE EAST LATE. NOT EXPECTING WINDS TO BE A SIGNIFICANT ISSUE THROUGH THE TAF PERIOD AS THEY BECOME NWLY/NLY BEHIND THE FRONT...THEN BEGIN TO SLACKEN AND BACK TOMORROW. BELIEVE KBLF/KLWB WILL SEE BEST SHOT OF -SHSN EARLY IN THE PERIOD...BUT WILL STAY WITH UPSLOPE -SHSN AND NO BETTER THAN MVFR THROUGH THE OVERNIGHT. EXPECT KBCB TO SEE MVFR CIGS WITH SOME -SHSN THROUGH THE FIRST PART OF THE PERIOD WITH IMPROVEMENT TO VFR WAITING UNTIL THE SHARP UPPER TROF SWINGS THROUGH LATE TONIGHT. KROA SHOULD REMAIN VFR WITH A FEW PERIODS OF MVFR THIS EVENING. LOW CLOUDS/FOG AT KDAN WERE HANGING TOUGH AT ISSUANCE TIME BUT VIS SAT LOOP WAS SHOWING SIGNIFICANT EROSION OF THE CLOUDS. BELIEVE THE IFR AT KDAN WILL BE SHORT LIVED AND WILL LEAVE IT OUT OF THE TAF. KDAN/KLYH WILL STAY VFR EARLY BUT AS THE WEAK FRONT MAKES IT TO THE PIEDMONT...EXPECTING SOME MVFR CIGS TO DEVELOP AND CONTINUE THROUGH JUST ABOUT DAYBREAK. TEMPS WARM ENOUGH FOR ANY LIGHT SHOWERS TO BEGIN AS LIQUID WITH A TRANSITION TO SNOW TONIGHT. THURSDAY THROUGH SUNDAY...THE REGION WILL REMAIN IN A VERY ACTIVE NORTHWEST FLOW PATTERN WITH A SERIES OF CLIPPER SYSTEM RACING THROUGH THE REGION ABOUT ONE EVERY TWO DAYS. THIS WILL ALLOW FOR RELATIVELY BRIEF PERIOD OF SUB-VFR CONDITIONS WITH THESE FEATURES FOLLOWED BY A VFR CONDITIONS IN BETWEEN SYSTEMS. CONFIDENCE IN TIMING OF THESE FEATURES IS LOW AT THIS TIME. THE MOST LIKELY PERIOD FOR SNOW SHOWERS AT THIS TIME LOOKS TO BE THURSDAY NIGHT AND FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ007- 009. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ015. NC...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ001- 018. WV...NONE. && $$ SYNOPSIS...DS NEAR TERM...DS SHORT TERM...PM LONG TERM...KM AVIATION...MBS