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