Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/02/13
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
925 AM EST SAT NOV 30 2013
.DISCUSSION...
CURRENT-THIS AFTERNOON...FIRST COUPLE OF VISIBLE SATELLITE IMAGES
SHOWING CLOUD COVER THINNING OUT TO THE EAST OF THE COAST FROM VERO
BEACH NORTH. SKIES EAST OF THE COAST FROM FORT PIERCE SOUTH WERE
CLOUDY AND RADAR SHOWED HEAVIER RAIN ASSOCIATED WITH A LINE OF WIND
CONVERGENCE THAT STRETCHED PAST GRAND BAHAMA. ANOTHER AREA OF
HEAVIER RAIN WAS APPROACHING THE BREVARD VOLUSIA COUNTY COAST
BETWEEN CAPE CANAVERAL AND PONCE INLET. THIS AREA OF RAIN SHOULD BE
SHORT LIVED AS THE VERTICAL WIND PROFILER(S) AT THE SPACE CENTER
WERE DETECTING EASTERLY WINDS 15 TO 20 MPH PUSHING THE RAIN TOWARD
THE COAST.
MORNING UPDATE WILL LOOK AT POTENTIAL CHANGES TO SKY COVER. WINDS
LOOK GOOD BASED ON THE VERTICAL WIND PROFILER OBSERVATIONS.
PREVIOUS ZONES DISCUSSION
TODAY...HIGH PRESSURE CENTERED OVER NEW ENGLAND WILL SHIFT EAST
WHILE ITS RIDGE AXIS EXTENDS SOUTHWARD ALONG THE EASTERN SLOPES OF
THE APPALACHIANS. THIS SLIGHT SHIFT IN ORIENTATION OF THE HIGH
SHOULD ALLOW THE INVERTED COASTAL TROUGH JUST OFFSHORE THE FL
EAST COAST TO BREAK DOWN...CAUSING WINDS TO VEER FROM NORTH TO
NORTHEAST BUT REMAINING BREEZY. IT WILL ALSO BRING SHOWERS ACROSS
THE COAST AND HAVE INCREASED RAIN CHANCES TO 30 PERCENT ALONG THE
COAST...20 PERCENT INTERIOR...WHICH IS A LITTLE ABOVE MOS
GUIDANCE. WOULD NOT BE SURPRISED IF THE FOCUS FOR SHOWERS IS THIS
MORNING WITH SOME DECREASE IN RAIN CHANCES THIS AFTN. THUNDER IS
NOT EXPECTED. MAX TEMPS WILL REACH THE MID TO UPPER 70S WHICH IS A
FEW DEGREES ABOVE NORMAL.
TONIGHT...WIND FLOW IS FORECAST TO VEER A LITTLE MORE TO THE ENE.
AS A RESULT...THE GFS PULLS SOME HIGHER MOISTURE TOWARD THE COAST
ASSOCD WITH AN OLD FRONTAL BOUNDARY. SO WILL HOLD ONTO SLIGHT
CHANCE (20 PERCENT) POPS FOR THE COAST. SFC WINDS OVER THE
INTERIOR WILL BECOME LIGHT NORTH WHICH MAY PRODUCE SOME LOW
CLOUDS/PATCHY FOG OVER THE FAR INTERIOR.
SUN/MON...MID LEVEL FLOW WILL BRIEFLY BECOME ZONAL EARLY SUNDAY
BEFORE BACKING SUNDAY NIGHT AND EARLY MONDAY IN RESPONSE TO TAIL END
OF QUICK MOVING SHORTWAVE WHICH WILL PASS OFFSHORE BY SUNSET MONDAY.
SHALLOW/MOIST ONSHORE FLOW WILL ADVECT SMALL COVERAGE OF SHOWERS
ONSHORE SUNDAY THROUGH EARLY MONDAY...MAINLY IMPACTING COASTAL
COUNTIES. SURFACE CONVERGENCE ASSOCIATED WITH WEAK FRONT WILL
PROLONG ISOLATED SHOWERS CHANCE INTO MONDAY...EVEN INLAND. NW WIND
SHIFT BY LATE AFTERNOON/EVENING WILL RETURN DRIER AIRMASS. TEMPS
SEVERAL DEGREES ABOVE NORMAL...ESPECIALLY MINS NEAR THE COAST.
TUE-FRI...ZONAL MID LEVEL FLOW TUE BECOMES INCREASINGLY ANTICYCLONIC
MID-LATE WEEK WITH 500 MB HEIGHTS RISING 12+ DM AS A RIDGE BUILDS
FROM THE YUCATAN PENINSULA TO SOUTH FLORIDA TO NEAR BERMUDA.
MEANWHILE...SURFACE HIGH SINKS SLOWLY SE FROM NEAR THE CAROLINA
COAST TO THE WESTERN ATLANTIC WITH THE RIDGE AXIS DROPPING TO
NORTH FLORIDA BY LATE WEDNESDAY...THEN SETTLING TO THE
CENTRAL/SOUTH PENINSULA THU/FRI. GENERALLY LIGHT FLOW VEERS TO
EASTERLY WED/THU AND SE FRI...TAPPING 1000-500 MB RELATIVE
HUMIDITY VALUES IN THE 40-45 PERCENT RANGE. FORECAST WILL
THEREFORE REMAIN DRY DURING THE EXTENDED PERIOD...WITH THE NEXT
THREAT OF SHOWER LIKELY HOLDING OFF TIL NEXT FRONT POSSIBLY
APPROACHES NEXT WEEKEND. TEMPS FALL TO NEAR CLIMO TUE IN WAKE OF
FRONTAL BOUNDARY/WIND SHIFT...THEN WILL REBOUND NEAR TWO DEGREE
PER DAY WED-FRI AS ONSHORE/VEERING FLOW SLOWLY MODIFIES AIRMASS.
&&
.AVIATION...
IFR CEILINGS OVER THE INTERIOR WEST OF KMCO BECOME MVFR/VFR AFTER
15Z AS THE MODERATE TO FRESH EASTERLY FLOW COMING IN FROM THE EAST
PUSHES THE LOW CLOUDS OUT OF THE AREA. TEMPO MVFR CEILINGS AND
VISIBILITIES ALONG THE COAST AS SHOWERS COME OFF THE ATLANTIC AND
MOVE INLAND. LOOKING AT PREVAILING MVFR/VFR AFTER 15Z NORTH OF KFPR
AS VISIBLE SATELLITE IMAGES SHOW THE CLOUD COVER BECOMING SCATTERED.
PREVIOUS AVIATION DISCUSSION
OCCASIONAL CIGS NEAR 010 AGL WILL OCCUR AT MCO/SFB/DAB THROUGH 12Z
BUT THEN SHOULD DIMINISH AS WINDS VEER FROM NORTH TO NE. EXPECT
A HIGHER STRATOCUMULUS CEILING TO AFFECT MUCH OF THE COAST THROUGH
00Z WITH BASES MAINLY AT OR ABOVE 035 AGL. THERE IS A CHANCE FOR
TEMPO MVFR CONDS AS ISOLATED TO SCATTERED SHOWERS PUSH INTO THE
COAST. SOME OF THE STRATOCUMULUS WILL PUSH TO THE INTERIOR
TERMINALS.
&&
.MARINE...
CURRENT-THIS AFTERNOON...REPORTS FROM BUOY 009 20NM EAST OF CAPE
CANAVERAL HAS SHOWN STEADY EASTERLY WINDS IN THE 20 TO 25 KNOT RANGE
WITH A SHARP INCREASE FROM 7 FEET TO 8 AND 9 PLUS FEET THE PAST
COUPLE OF HOURS DUE TO THE STRONGER WINDS BUILDING THE SEAS. THE
SCRIPPS BUOY 4NM EAST OF PORT CANAVERAL WAS RECORDING 5 FOOT SEAS
AND THE BUOY 6NM NORTHEAST OF FORT PIERCE INLET WAS RECORDING 7 FOOT
SEAS. THE LATEST RUC AND MSAS SURFACE ANALYSIS INDICATE THAT THE
SURFACE TROUGH EAST OF FLORIDA WAS SLOW TO BREAK DOWN. WINDS/SEAS
MAY BE A BIT LOW BUT WILL WATCH THE BUOY REPORTS FOR ANOTHER HOUR
BEFORE MAKING ANY SIGNIFICANT CHANGES TO THE AFTERNOON FORECAST.
PREVIOUS MARINE DISCUSSION
TODAY/TONIGHT...BOATING CONDITIONS WILL REMAIN POOR FOR SMALL
CRAFT ESPECIALLY IN THE GULF STREAM. COASTAL TROUGH WILL BREAK
DOWN AND WINDS SHOULD BECOME UNIFORMLY NE ACROSS THE WATERS.
PRESSURE GRADIENT WILL SUPPORT 15-20 KNOTS WITH SEAS 5 TO 7
FEET...AND A LITTLE HIGHER IN THE GULF STREAM. SO WILL MAINTAIN
SMALL CRAFT ADVISORY FOR ALL THE WATERS TODAY. WINDS SHOULD
BEGIN TO DECREASE A BIT TONIGHT AS PRES GRAD SLACKENS SUPPORTING
AROUND 15 KNOTS. SHOULD BE ABLE TO TRANSITION TO ADVISORY FOR THE
GULF STREAM ONLY WITH A CAUTION FOR THE NEARSHORE WATERS TONIGHT.
SUN-WED...NE/E FLOW LESSENS BELOW 15 KT BUT LONG ONSHORE FETCH MEANS
SEAS WILL BE SLOW TO SUBSIDE. WILL EXTEND SCA FOR SEAS WITHIN THE
GULF STREAM THROUGH THE AFTERNOON. BRIEF INCREASE OF NW FLOW
BEHIND FRONT MONDAY WILL BUMP WINDS TO NEAR 15 KT AND SUSTAIN SEAS
5-6 FEET WITHIN GULF STREAM...AND 3-4 FT NEAR SHORE THROUGH
DAYBREAK TUE. WIND/SEA CONDITIONS IMPROVE SIGNIFICANTLY BY WED AS
LOW LEVEL RIDGE AXIS BUILDS DOWN THE ATLANTIC SEABOARD.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR COASTAL
WATERS FROM FLAGLER BEACH TO SEBASTIAN INLET OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR COASTAL WATERS
FROM SEBASTIAN INLET TO JUPITER INLET OUT 20 NM-WATERS FROM
FLAGLER BEACH TO JUPITER INLET 20 TO 60 NM OFFSHORE.
&&
$$
UPDATES.....WIMMER
IMPACT WX...PENDERGRAST
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
951 PM EST SUN DEC 1 2013
.UPDATE...
NO CHANGES PLANNED AT THIS TIME. THERE REMAINS SOME UNCERTAINTY AS
TO WHERE THE LIGHT RAIN WILL IMPACT THE FORECAST AREA...TIMING
AROUND AND JUST AFTER MORNING RUSH HOUR LOOKS GOOD...CONFIDENCE IS
STILL TOO LOW TO MAKE ANY CHANGES.
&&
.PREV DISCUSSION... /ISSUED 214 PM EST SUN DEC 1 2013/
SHORT TERM /TONIGHT THROUGH TUESDAY/...
LATEST SURFACE ANALYSIS OVER THE SOUTHEAST UNITED STATES SHOWS
WEAK HIGH PRESSURE CONTINUING TO BE THE DOMINATING INFLUENCE OF
THE LOCAL WX. EAST AND SOUTHEAST FLOW ON SOUTHERN PERIPHERY OF
THIS HIGH EARLIER ALLOWED FOR LOW LEVEL MOISTURE TO ADVECT IN A
RESULT IN WIDESPREAD LOW CLOUDS. SINCE THEN...DEVELOPING
SOUTHWEST FLOW DUE TO A SHIFT IN THE HIGH POSITION HAS ALLOWED
FOR THE EROSION OF MOST OF THE LOW CLOUDS BUT HAS QUICKLY BEEN
REPLACED BY A THIN VEIL OF CIRRUS. TEMPS LOOKS TO BE LARGELY
UNAFFECTED BY THIS AS WE ARE ALREADY WITHING THREE DEGREES OF
FORECAST HIGH OF ATLANTA CURRENTLY.
FOR TONIGHT...THE FIRST IN A SERIES OF EMBEDDED SHORTWAVES WILL
MOVE THROUGH ZONAL FLOW TO PRODUCE AN AREA OF MAINLY LIGHT RAIN
OVER ALABAMA. MODELS HAVE BEEN BACKING OFF ON HOW MUCH THIS
ENERGY TRANSLATES INTO ACTUAL PRECIP OVER OUR AREA AND INDEED
FEEL AMOUNTS WILL BE ON THE LOW SIDE EVEN OVER WESTERN PORTIONS.
THAT SAID...BASED ON WRF AND HRRR RUNS...IT SHOULD STILL RAIN
EVEN IF ITS LIGHT AND HAVE UPPED CHANCES ALONG THE WEST CENTRAL
BORDER THROUGH 15Z MONDAY. WILL LET EVENING AND MID SHIFT TAKE
ANOTHER LOOK AS MAY STILL BE TOO LOW...GOING JUST BELOW LIKELY AT
THIS POINT.
WAVE CLEARS DURING THE AFTERNOON BUT ANOTHER WILL BE RIGHT ON ITS
HEELS INTO MONDAY NIGHT. THIS ONE WILL BE MOVING MORE SOUTHWEST
TO NORTHEAST TO AFFECT MAINLY THE NORTHERN TIER WITH MID RANGE
CHANCE POPS. IN ADDITION TO LIGHT RAIN...COULD SEE SOME PATCHY
FOG DEVELOPMENT WITH THIS SYSTEM OVER THE MOUNTAINS AND ALONG OUR
WESTERN BORDER WITH ALABAMA.
INCREASING TEMPERATURES THROUGH THE SHORT TERM WITH MID 60S TO
AROUND 70 EXPECTED BY TUESDAY AFTERNOON. THIS WOULD BE A RADICAL
DEPARTURE FROM THE EXTREME COLD OF THIS PAST WEEK AND WOULD
RESULT IN TEMPS SOME 10 DEGREES ABOVE CLIMO.
DEESE
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
SOME CHANGES MADE TO THE EXTENDED BASED ON GUIDANCE WHICH IS
COMING IN QUITE A BIT WARMER FOR LATER IN THE WEEK. AHEAD OF THE
FRONT PROGGED TO STALL ACROSS THE TENNESSEE VALLEY WHICH WILL
SLOWLY MAKE ITS WAY TO THE SOUTHERN APPALACHIANS BY FRIDAY.
RIDGING IN THE GULF REMAINS PRETTY STRONG BUT ALSO STRONGER LOW-
LEVEL WAA. INCREASED TEMPS QUITE A BIT AND ACTUALLY HAVE NEAR-
RECORD TO RECORD WARM MIN TEMPS FOR FRIDAY MORNING. POPS STILL
LOOKING GOOD BUT WILL PROBABLY HAVE TO INCREASE THEM AS WE
PROGRESS THROUGH THE WEEK.
THERE IS SOME CONCERN ABOUT HAZARDOUS WEATHER AS GFS CAPES ARE ON
THE INCREASE ESPECIALLY FOR FRIDAY AFTERNOON AND SOME QPF VALUES
ARE PRETTY HEFTY...BUT WILL NARROW THAT DOWN AS WE GET CLOSER. A
LOT OF UNCERTAINTY ON TIMING OF FROPA AND SUBSEQUENT CAD ONSET...
ECMWF A LITTLE FASTER THAN THE GFS ON FROPA BUT BOTH HAVE SIMILAR
TIMING WITH CAD ONSET....SO MADE NO CHANGES TO SATURDAY /AS THE
SIGNIFICANT COOL-DOWN STARTS/ AND BEYOND BECAUSE OF THAT
UNCERTAINTY. WILL BE INTERESTING TO SEE WHAT SENSIBLE WEATHER
IMPACTS OCCUR WITH THE DIABATICALLY-ENHANCED CAD EVENT FOR EARLY
NEXT WEEK. SEE PREVIOUS DISCUSSION BELOW.
TDP
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
/ISSUED AT 342 AM EST SUN DEC 1 2013/ ONLY SMALL CHANCES FOR
LIGHT RAIN MONDAY NIGHT AND TUESDAY DUE TO THE POTENTIAL OF A WEAK
SHORT WAVE PASSING AND INCREASING ALTHOUGH WEAK SOUTHERLY LOW
LEVEL FLOW. THIS WILL ALSO ALLOW THE AIRMASS TO WARM DURING THIS
PERIOD.
THE GFS AND EUROPEAN ARE IN BETTER AGREEMENT FOR THE EXTENDED
PERIOD. SMALL CHANCES FOR LIGHT SHOWERS CONTINUE WEDNESDAY FROM
SOUTHERLY LOW LEVEL FLOW AHEAD OF THE NEXT FRONT. GFS FASTER
MOVING THE FRONT TO FAR NW GA LATE WEDNESDAY AND THE EUROPEAN
MOVING THE FRONT TO THE OH AND LOWER MS VALLEYS. EITHER WAY
DYNAMICS ARE WEAK.
MOIST SW FLOW ALOFT INCREASES THURSDAY AND CONTINUES INTO
SATURDAY AS THE COLD FRONT SHARPENS OVER THE TN VALLEY/SRN
APPALACHIANS THURSDAY AND MOVES TO CENTRAL GA LATE FRIDAY AND TO
SE GA/N FL ON SATURDAY. OVERALL THIS WILL MEAN A WETTER PERIOD...
MOST SO FOR N GA...ALONG WITH WARMER OVERALL TEMPERATURES UNTIL
THE FRONT PASSES BY.
A COLD AIR DAMMING EVENT LOOKS TO SET UP FOR SUNDAY.
BDL
PREV DISCUSSION... /ISSUED 653 PM EST SUN DEC 1 2013/
AVIATION...
00Z UPDATE...
WINDS WILL REMAIN WEST THROUGH THE PERIOD...GENERALLY 3-8KTS. VFR
CONDITIONS WILL PERSIST...WITH BRIEF MVFR POSSIBLE IN THE ATL AREA
TAFS AND AHN...MVFR EXPECTED IN CSG AND MCN. LIGHT RAIN WILL BE
POSSIBLE 15-20Z MAINLY ACROSS ATL SITES.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE ON CIGS/WEATHER.
HIGH CONFIDENCE WINDS/VISIBILITY.
ATWELL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 56 39 60 48 / 5 10 20 30
ATLANTA 59 45 59 49 / 5 20 50 30
BLAIRSVILLE 56 37 53 45 / 5 10 30 30
CARTERSVILLE 55 40 56 48 / 5 40 40 30
COLUMBUS 63 46 65 50 / 5 20 20 20
GAINESVILLE 54 42 55 48 / 5 10 20 30
MACON 58 42 66 44 / 5 10 20 20
ROME 54 41 56 48 / 0 40 50 30
PEACHTREE CITY 57 40 60 43 / 5 20 50 30
VIDALIA 55 47 66 48 / 5 5 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL
LONG TERM....SNELSON
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
653 PM EST SUN DEC 1 2013
.PREV DISCUSSION... /ISSUED 214 PM EST SUN DEC 1 2013/
SHORT TERM /TONIGHT THROUGH TUESDAY/...
LATEST SURFACE ANALYSIS OVER THE SOUTHEAST UNITED STATES SHOWS
WEAK HIGH PRESSURE CONTINUING TO BE THE DOMINATING INFLUENCE OF
THE LOCAL WX. EAST AND SOUTHEAST FLOW ON SOUTHERN PERIPHERY OF
THIS HIGH EARLIER ALLOWED FOR LOW LEVEL MOISTURE TO ADVECT IN A
RESULT IN WIDESPREAD LOW CLOUDS. SINCE THEN...DEVELOPING
SOUTHWEST FLOW DUE TO A SHIFT IN THE HIGH POSITION HAS ALLOWED
FOR THE EROSION OF MOST OF THE LOW CLOUDS BUT HAS QUICKLY BEEN
REPLACED BY A THIN VEIL OF CIRRUS. TEMPS LOOKS TO BE LARGELY
UNAFFECTED BY THIS AS WE ARE ALREADY WITHING THREE DEGREES OF
FORECAST HIGH OF ATLANTA CURRENTLY.
FOR TONIGHT...THE FIRST IN A SERIES OF EMBEDDED SHORTWAVES WILL
MOVE THROUGH ZONAL FLOW TO PRODUCE AN AREA OF MAINLY LIGHT RAIN
OVER ALABAMA. MODELS HAVE BEEN BACKING OFF ON HOW MUCH THIS
ENERGY TRANSLATES INTO ACTUAL PRECIP OVER OUR AREA AND INDEED
FEEL AMOUNTS WILL BE ON THE LOW SIDE EVEN OVER WESTERN PORTIONS.
THAT SAID...BASED ON WRF AND HRRR RUNS...IT SHOULD STILL RAIN
EVEN IF ITS LIGHT AND HAVE UPPED CHANCES ALONG THE WEST CENTRAL
BORDER THROUGH 15Z MONDAY. WILL LET EVENING AND MID SHIFT TAKE
ANOTHER LOOK AS MAY STILL BE TOO LOW...GOING JUST BELOW LIKELY AT
THIS POINT.
WAVE CLEARS DURING THE AFTERNOON BUT ANOTHER WILL BE RIGHT ON ITS
HEELS INTO MONDAY NIGHT. THIS ONE WILL BE MOVING MORE SOUTHWEST
TO NORTHEAST TO AFFECT MAINLY THE NORTHERN TIER WITH MID RANGE
CHANCE POPS. IN ADDITION TO LIGHT RAIN...COULD SEE SOME PATCHY
FOG DEVELOPMENT WITH THIS SYSTEM OVER THE MOUNTAINS AND ALONG OUR
WESTERN BORDER WITH ALABAMA.
INCREASING TEMPERATURES THROUGH THE SHORT TERM WITH MID 60S TO
AROUND 70 EXPECTED BY TUESDAY AFTERNOON. THIS WOULD BE A RADICAL
DEPARTURE FROM THE EXTREME COLD OF THIS PAST WEEK AND WOULD
RESULT IN TEMPS SOME 10 DEGREES ABOVE CLIMO.
DEESE
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
SOME CHANGES MADE TO THE EXTENDED BASED ON GUIDANCE WHICH IS
COMING IN QUITE A BIT WARMER FOR LATER IN THE WEEK. AHEAD OF THE
FRONT PROGGED TO STALL ACROSS THE TENNESSEE VALLEY WHICH WILL
SLOWLY MAKE ITS WAY TO THE SOUTHERN APPALACHIANS BY FRIDAY.
RIDGING IN THE GULF REMAINS PRETTY STRONG BUT ALSO STRONGER LOW-
LEVEL WAA. INCREASED TEMPS QUITE A BIT AND ACTUALLY HAVE NEAR-
RECORD TO RECORD WARM MIN TEMPS FOR FRIDAY MORNING. POPS STILL
LOOKING GOOD BUT WILL PROBABLY HAVE TO INCREASE THEM AS WE
PROGRESS THROUGH THE WEEK.
THERE IS SOME CONCERN ABOUT HAZARDOUS WEATHER AS GFS CAPES ARE ON
THE INCREASE ESPECIALLY FOR FRIDAY AFTERNOON AND SOME QPF VALUES
ARE PRETTY HEFTY...BUT WILL NARROW THAT DOWN AS WE GET CLOSER. A
LOT OF UNCERTAINTY ON TIMING OF FROPA AND SUBSEQUENT CAD ONSET...
ECMWF A LITTLE FASTER THAN THE GFS ON FROPA BUT BOTH HAVE SIMILAR
TIMING WITH CAD ONSET....SO MADE NO CHANGES TO SATURDAY /AS THE
SIGNIFICANT COOL-DOWN STARTS/ AND BEYOND BECAUSE OF THAT
UNCERTAINTY. WILL BE INTERESTING TO SEE WHAT SENSIBLE WEATHER
IMPACTS OCCUR WITH THE DIABATICALLY-ENHANCED CAD EVENT FOR EARLY
NEXT WEEK. SEE PREVIOUS DISCUSSION BELOW.
TDP
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
/ISSUED AT 342 AM EST SUN DEC 1 2013/ ONLY SMALL CHANCES FOR
LIGHT RAIN MONDAY NIGHT AND TUESDAY DUE TO THE POTENTIAL OF A WEAK
SHORT WAVE PASSING AND INCREASING ALTHOUGH WEAK SOUTHERLY LOW
LEVEL FLOW. THIS WILL ALSO ALLOW THE AIRMASS TO WARM DURING THIS
PERIOD.
THE GFS AND EUROPEAN ARE IN BETTER AGREEMENT FOR THE EXTENDED
PERIOD. SMALL CHANCES FOR LIGHT SHOWERS CONTINUE WEDNESDAY FROM
SOUTHERLY LOW LEVEL FLOW AHEAD OF THE NEXT FRONT. GFS FASTER
MOVING THE FRONT TO FAR NW GA LATE WEDNESDAY AND THE EUROPEAN
MOVING THE FRONT TO THE OH AND LOWER MS VALLEYS. EITHER WAY
DYNAMICS ARE WEAK.
MOIST SW FLOW ALOFT INCREASES THURSDAY AND CONTINUES INTO
SATURDAY AS THE COLD FRONT SHARPENS OVER THE TN VALLEY/SRN
APPALACHIANS THURSDAY AND MOVES TO CENTRAL GA LATE FRIDAY AND TO
SE GA/N FL ON SATURDAY. OVERALL THIS WILL MEAN A WETTER PERIOD...
MOST SO FOR N GA...ALONG WITH WARMER OVERALL TEMPERATURES UNTIL
THE FRONT PASSES BY.
A COLD AIR DAMMING EVENT LOOKS TO SET UP FOR SUNDAY.
BDL
&&
.AVIATION...
00Z UPDATE...
WINDS WILL REMAIN WEST THROUGH THE PERIOD...GENERALLY 3-8KTS. VFR
CONDITIONS WILL PERSIST...WITH BRIEF MVFR POSSIBLE IN THE ATL AREA
TAFS AND AHN...MVFR EXPECTED IN CSG AND MCN. LIGHT RAIN WILL BE
POSSIBLE 15-20Z MAINLY ACROSS ATL SITES.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE ON CIGS/WEATHER.
HIGH CONFIDENCE WINDS/VISIBILITY.
ATWELL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 41 60 48 65 / 10 20 30 30
ATLANTA 46 59 49 66 / 20 50 30 30
BLAIRSVILLE 39 53 45 58 / 10 30 30 40
CARTERSVILLE 42 56 48 66 / 40 40 30 30
COLUMBUS 46 65 50 69 / 20 20 20 10
GAINESVILLE 43 55 48 62 / 10 20 30 30
MACON 41 66 44 69 / 10 20 20 10
ROME 41 56 48 65 / 40 50 30 30
PEACHTREE CITY 41 60 43 67 / 20 50 30 20
VIDALIA 48 66 48 71 / 5 10 20 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL
LONG TERM....SNELSON
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
404 PM CST SAT NOV 30 2013
.DISCUSSION...
252 PM CST
SYNOPSIS...MORE SEASONAL TEMPERATURES WILL BE WITH US THROUGH EARLY
NEXT WEEK...WITH TEMPS PEAKING MID WEEK. THEN TEMPS QUICKLY FALL
TO WELL BELOW NORMAL BY NEXT WEEKEND. THERE A FEW SLIGHT CHANCES OF
PRECIP EARLY NEXT WEEK WITH A MUCH BETTER CHANCE FOR PRECIP MID
WEEK. THE MID WEEK SYSTEM WILL BRING MOSTLY RAIN WITH A CHANCE OF
WINTRY PRECIP LATE NEXT WEEK.
REST OF TODAY THROUGH SUNDAY...
WEAK LOW PRESSURE IS OVER LAKE SUPERIOR AND NORTHERN WI WITH ITS
COLD FRONT STRETCHING FROM MEDFORD WI THROUGH MASON CITY IA. THE
LOW WILL CONTINUE EASTWARD AND DISSIPATE OVER THE EASTERN GREAT
LAKES SUNDAY NIGHT. WE HAVE MIXED MUCH MORE THAN WE WERE EXPECTING
TODAY...RESULTING IN HIGH TEMPS IN THE LOWER 50S. NOT BAD FOR LATE
NOVEMBER! AS SUCH RAISED LOW TEMPS BY A COUPLE DEGREES TONIGHT.
CLOUDS WILL ALSO BE INCREASING THIS EVENING AND OVERNIGHT LIMITING
COOLING.
AN UPPER LEVEL SHORTWAVE PASSES OVERHEAD TOMORROW MORNING WITH NO
PRECIP EXPECTED. CAA ALOFT AND WEAK SURFACE FLOW LEAD ME TO BELIEVE
WE WILL BE A BIT COOLER TOMORROW WITH HIGHS AROUND 40.
MONDAY AND TUESDAY...
ANOTHER SLIGHTLY DEEPER UPPER LEVEL SHORTWAVE ARRIVES MONDAY.
THIS TROUGH IS ALSO FURTHER SOUTH MOVING RIGHT OVER NORTHERN
IL...WHICH MAY PROVIDE JUST ENOUGH FORCING FOR A LITTLE LIGHT
PRECIP. TEMPS WILL BE ON THE RISE THROUGH THE MORNING SO WENT WITH
LIGHT SNOW AT FIRST TURNING OVER TO RAIN BY MONDAY AFTERNOON. THE
PRECIP WILL TRAVEL EAST WITH THE SHORTWAVE THROUGH THE DAY. HIGH
TEMPS ON MONDAY WILL ONCE AGAIN BE AROUND 40.
AN UPPER LEVEL VORT STREAMER PASSES JUST TO THE NORTH LATE MONDAY
NIGHT WHICH MAY PRODUCE A LITTLE LIGHT SNOW OVER NORTH CENTRAL IL.
MAY SEE A LITTLE MORE PRECIP COVERAGE TUESDAY MORNING WITH PRECIP
TURNING OVER TO RAIN AS TEMPS WARM. THE FORCING THEN LIFTS OFF TO
THE NE SO KEPT A SLIGHT CHANCE OF PRECIP OVER NORTH CENTRAL IL
TUESDAY AFTERNOON WITH THE MAJORITY OF PRECIP STAYING NORTH OF OUR
REGION CLOSER TO THE VORT STREAMER.
A STATIONARY FRONT THEN STRETCHES OVER NORTHERN IL TUESDAY NIGHT SO
KEPT A SLIGHT CHANCE TO CHANCE OF RAIN GOING. WAA ALOFT WILL KEEP
TUESDAY NIGHT TEMPS ABOVE FREEZING.
WEDNESDAY THROUGH FRIDAY...
THE UPPER LEVEL RIDGE SHIFTS TO THE EAST WITH SOUTHWEST FLOW SETTING
UP THROUGH LATE FRIDAY. THE UPPER LEVEL TROUGH AXIS PASSES OVERHEAD
SATURDAY. LONG DISTANCE GUIDANCE AGREES ON THE OVERALL
PATTERN...BUT THE GFS AND ECMWF DIFFER GREATLY ON WHEN THESE
FEATURES WILL IMPACT THE REGION. WENT WITH THE MORE STEADY ECMWF IN
THE LONG TERM AS THE GFS LOOKS MUCH TOO FAST.
A SURFACE LOW MOVES OVER THE CENTRAL PLAINS LATE TUESDAY NIGHT INTO
WEDNESDAY WITH WAA IMPACTING THE REGION TUESDAY NIGHT THROUGH
WEDNESDAY EVENING. WITH ALL OF THE WAA RAISED TEMPS TUESDAY NIGHT
AND WEDNESDAY...AND HONESTLY...STILL THINK TEMPS ARE TOO LOW. COULD
EASILY SEE AT LEAST LOW 50S ON WEDNESDAY.
RAIN ARRIVES BEHIND THE WARM FRONT WEDNESDAY AFTERNOON WITH GUIDANCE
BACKING OFF A LITTLE WITH QPF...TO AROUND 0.1 INCHES. THE LOWS COLD
FRONT SWINGS THROUGH WED NIGHT/THURSDAY WITH TEMPS CRASHING BEHIND
IT. COULD EASILY SEE A 10+ DEGREE DIFFERENCE IN HIGH TEMPS WEDNESDAY
AND THURSDAY. PRECIP MAY LINGER A BIT BEHIND THE COLD
FRONT...MEANING WINTRY PRECIP IS POSSIBLE. GUIDANCE INDICATES
PRECIP WILL ALSO FORM AHEAD OF THE UPPER LEVEL TROUGH
AXIS...RESULTING IN RAIN/SNOW THURSDAY BECOMING ALL SNOW THURSDAY
NIGHT THROUGH LATE FRIDAY.
ARCTIC AIR MOVES IN WITH THE TROUGH AXIS RESULTING IN HIGH TEMPS IN
THE 20S LATE NEXT WEEK. MAY EVEN SEE HIGH TEMPS IN THE TEENS ON
SATURDAY.
CONFIDENCE IS HIGH THAT THE SYSTEM WILL IMPACT THE REGION MID NEXT
WEEK...PRECIP WILL BE MOSTLY RAIN...AND IN TEMP TRENDS. MEDIUM
CONFIDENCE IN HOW LONG PRECIP WILL LINGER.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* MVFR CIGS POSSIBLE SUNDAY MORNING
IZZI
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE WAS OVER NEW ENGLAND AND WEAK LOW PRESSURE WAS OVER
LAKE SUPERIOR AT MIDDAY...WITH A COLD FRONT TRAILING THROUGH
NORTHWEST WISCONSIN AND IOWA. SOUTHWEST FLOW AHEAD OF THE FRONT
WAS BRINGING MILD DRY AIR TO THE REGION. A FAIRLY SHALLOW
INVERSION IS IN PLACE BUT WITH FULL SUN THERE IS ENOUGH MIXING FOR
A FEW GUSTS IN THE MID TO UPPER TEENS THIS AFTERNOON. LATE THIS
AFTERNOON WITH LOSS OF HEATING AND MIXING...WINDS AND GUSTS WILL
DIMINISH. WINDS WILL GRADUALLY VEER FROM SSW TO SW TO WSW THROUGH
THE EVENING HOURS AS THE FRONT APPROACHES. WINDS WILL BE LIGHT AS
THE WEAK FRONT SLIPS THROUGH THE AREA. NEW SHORT RANGE MODELS ALL
VERY SIMILAR IN TIMING OF THE FRONTAL PASSAGE THROUGH THE
TERMINALS. WINDS WILL QUICKLY SHIFT TO NW BEHIND THE FRONT...THEN
GRADUALLY CONTINUE TO COME AROUND TO NNE DURING THE DAY SUNDAY.
MAIN CONCERN IS FOR THE POTENTIAL OF MVFR CIG AND SOME LIGHT FOG
AND HAZE IN THE EARLY MORNING BEHIND THE FRONT. NAM AND LOCAL ARW
MOST AGGRESSIVE IN MOISTENING LOWEST PART OF SOUNDING. THIS WOULD
SUGGEST CIGS AT OR BELOW 1000 FT WITH SOME FOG AND HAZE. GFS KEEPS
INVERSION AROUND 2500 FT. TIMING OF STRATUS COULD BE DELAYED A FEW
HOURS AFTER FROPA. FOR NOW WILL CONTINUE TREND OF PREVIOUS
FORECAST WITH CIGS AROUND 2K FT AFTER FROPA.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN WIND FORECAST
* HIGH CONFIDENCE IN VFR CONDITIONS THROUGH TONIGHT
* LOW/MEDIUM CONFIDENCE ON MVFR CIGS SUNDAY MORNING
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR...THOUGH MVFR CIGS POSSIBLE.
MONDAY INTO TUESDAY...MVFR CIGS POSSIBLE. SLIGHT CHANCE -RASN.
WEDNESDAY...MVFR CIGS PROBABLE CHANCE OF IFR. CHANCE OF RAIN.
THURSDAY...MVFR CIGS PROBABLE. CHANCE -RASN.
FRIDAY...VFR.
RATZER
&&
.MARINE...
252 PM CST
WINDS WILL TURN NORTH TONIGHT THROUGH THE OVERNIGHT BEHIND A COLD
FRONT...BUT WILL BE LIGHTER AT 20 KT OR LESS DUE TO A WEAK PRESSURE
GRADIENT. THE GENERALLY LIGHT WIND REGIME WILL CONTINUE SUNDAY INTO
TUESDAY MORNING WITH WINDS GRADUALLY SHIFTING FROM NORTHEAST TO
SOUTHEAST. UNCERTAINTY THEN INCREASES AMONGST MEDIUM RANGE GUIDANCE
WITH TRACK AND TIMING OF LOW PRESSURE SYSTEM MOVING EAST FROM THE
PLAINS. WITH THIS FORECAST PACKAGE HAVE FAVORED A SLOWER TIMING OF
THIS SYSTEM...WHICH WILL RESULT IN INCREASINGLY STRONG SOUTHEAST TO
SOUTH WINDS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A COLD FRONT IS
THEN EXPECTED TO SWEEP ACROSS THE LAKE ON THURSDAY AS THE LOW TRACKS
TO OR NORTH OF LAKE SUPERIOR BY THURSDAY. THIS WILL RESULT IN
STRONGER SOUTHWEST TO WESTERLY WINDS. THE POTENTIAL EXISTS FOR A
PERIOD OR TWO OF GALES IN ASSOCIATION WITH THIS SYSTEM...BUT DUE TO
THE UNCERTAINTY...THERE ARE NO GALES IN THE FORECAST YET. THE ACTIVE
PATTERN OVER THE LAKE THEN LOOKS TO CONTINUE INTO NEXT WEEKEND.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
336 PM CST Sat Nov 30 2013
.DISCUSSION...
ISSUED 335 PM CST Sat Nov 30 2013
A relatively mild weather pattern will start out the first few
days of December, before our next best chance of precipitation and
much colder air moves in for the latter part of the week. The
short range models are in fair agreement into the first part of
next week. However, the medium range solutions diverge
significantly by mid-week which has pretty big implications on the
forecast.
SHORT TERM...Tonight through Monday
A weak cold front from western WI across southern MN and South
Dakota is expected to approach central IL Sunday morning. Ahead of
this front, a light wind and dew points mainly in the lower 30s
could result in some light fog and few low clouds late tonight and
early Sunday morning. The NAM model is hitting this harder than
the others, which it has been doing more so lately and seems to
have this tendency in the cool season. Will go with partly cloudy
conditions for now and monitor this evening.
Mild conditions are expected on Sunday, with readings of 45 to 50
in central IL and the lower 50s south of I-70. The forecast gets a
bit tricky for Sunday night into Monday as a shortwave in the WNW
flow approaches the state. Many of the short range model solutions
are depicting the potential for light rain as early as late Sunday
night and during the day Monday. Will hold off on any mention for
Sunday night into early Monday morning because of a fairly thick
layer of dry air expected between 850-925 mb. Will stick with the
slight chance for rain during the day Monday as a bit stronger
lift could produce isolated pockets of light rain.
LONG TERM...Tuesday through Saturday
There are quiet significant model differences between the GFS,
Canadian and European solutions starting Tuesday, which continues
right through the rest of the forecast period. The GFS is much
quicker with shifting an upper level low from the Pacific NW
across the northern states. However, while it is doing this, it is
also digging a portion of the upper level energy toward the
southwestern U.S. This should result in upper level ridging in the
Midwest, which would force any northern energy up into central
Canada. The GFS does not do this though, which results in a cold
front moving through late Tuesday/early Wednesday. The European
and Canadian model solutions make much more sense by holding off
on the frontal passage at least 24-36 hours later, on early
Thursday.
Several shortwaves moving up from the southwest, and a slowing
front expected to become parallel to the flow aloft will mean
periods of precipitation from Wednesday through much of Friday.
Rain will be the primary precipitation type at onset on Wednesday,
but then as colder air gradually advects toward the region, a
mixture changing to snow is anticipated - primarily later in the
day Thursday, and especially Friday. The best low level moisture
and forcing is expected to the east and south of our region -
closer to the frontal position - near the Ohio Valley. Thus, at
this time we are not anticipating any major snow amounts, but with
the complex evolution of this system and the fact that it is six days
away, the confidence factor is not very high either way.
Miller
&&
.AVIATION...
ISSUED 1105 AM CST Sat Nov 30 2013
High pressure sliding to the east giving way to increasing RH in
the region resulting in a troublesome forecast for the overnight
hours in ILX terminals. NAM has far more moisture trapped in the
boundary layer and guidance resulting in everything from MVFR vis
to LIFR cigs and vis. GFS in the same shape with less moisture and
the HRRR is a little slower and more conservative but still
moisture laden particularly NW of the Illinois River Valley.
Trouble is, lower res models have increased moisture already in
central MO, and sat imagery pointing to an overdone model run.
That being said, dewpoints are on the increase with swrly flow.
HRRR depiction of sfc RH a little more on track and def
highlighting overnight NW of the IL river. Trouble is whether or
not we are looking at stratus developing or vis drop. Not to
mention that if enough moisture makes it into the SE and does not
mix out this afternoon, chance for reduced vis in the SE as the
skies clear out a bit tonight. For now, forecast conservative, but
starting the trend for a visibility drop with majority rule to a
cloud deck in the 4000 to 5000 ft range for PIA BMI and SPI this
evening and through the overnight.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1152 AM CST SAT NOV 30 2013
.DISCUSSION...
1051 AM CST
MORNING UPDATE...
MIXING HEIGHTS ARE FAIRLY SHALLOW TODAY...BUT SOUTH-SOUTHWEST WARM
ADVECTION PATTERN AND FULL SUNSHINE ARE RESULTING IN A MUCH MORE
PLEASANT DAY THAN WE HAVE SEEN OF LATE. TEMPERATURES WERE
INITIALLY SLOW TO RISE THIS MORNING...BUT SINCE HAVE BEEN QUICKLY
WARMING. BASED ON TRENDS AND EXPECTATIONS OF CONTINUED STEADY
WARMING UNTIL ABOUT 3PM...HAVE BUMPED UP HIGH TEMPERATURES TO THE
MID AND UPPER 40S NORTH OF I-80 AND UPPER 40S TO LOCALLY AROUND 50
SOUTH OF I-80. WILL CONTINUE TO MONITOR TEMPERATURE TRENDS...AS
SOME SHORT RANGE GUIDANCE INDICATES THE POTENTIAL TO WARM EVEN A
BIT MORE THAN THIS.
RC
//PREV DISCUSSION...
248 AM CST
PRIMARY FORECAST CHALLENGE WILL BE PINNING DOWN BEST CHANCES FOR
PRECIP AS PATTERN BECOMES ACTIVE NEXT WEEK...
THIS WEEKEND...
QUIET WEATHER SHOULD PREVAIL LOCALLY AS DEPARTING HIGH PRESSURE
ALLOWS RETURN FLOW INTO THE UPPER MIDWEST TO HELP MODERATE
TEMPERATURES THIS AFTERNOON. GUIDANCE IN PRETTY GOOD AGREEMENT
INDICATING LOW TO MID 40S ACROSS THE CWA TODAY. BLENDED TOWARDS NAM
WHICH HAS A DECENT ALBEIT TOO FAR SOUTH AND TOO BROAD A HANDLE ON
THE SNOWFALL CURRENTLY ON THE GROUND ACROSS THE FAR NORTHERN
CWA...BUT INDICATES THOSE AREAS WILL NOT GET OUT OF THE UPPER 30S
THIS AFTERNOON.
A CLIPPER SYSTEM WILL BRING SNOW TO THE NORTHERN LAKES REGION THIS
WEEKEND...BUT A TRAILING COLD FRONT WHICH WILL PASS OVER THE LOCAL
AREA TONIGHT AND EARLY SUNDAY WILL BE MOISTURE STARVED AND LIKELY
NOT PRODUCE ANY PRECIPITATION. THE CAVEAT...NAM GUIDANCE IN
PARTICULAR CONTINUES TO INDICATE A SHALLOW POST FRONTAL STRATUS DECK
WITH WEAK HEIGHT FALLS AS A SHEARED UPPER WAVE PUSHES ACROSS THE
AREA...WHICH MAY CULMINATE IN LIGHT FREEZING DRIZZLE. BUT GIVEN THE
NAMS LOW LEVEL MOISTURE BIAS AND THE GFS BACKING OFF ON A STRONGER
UPPER WAVE THAT PREVIOUS RUNS WERE ADVERTISING...WILL CONTINUE TO
MAINTAIN A DRY FORECAST.
MONDAY AND TUESDAY...
STRONG UPPER LOW DIGGING ACROSS THE PAC NW THIS PERIOD WILL RESULT
IN DOWNSTREAM AMPLIFICATION OF LONGWAVE RIDGE AS STRONG WARM
ADVECTION DEVELOPS ACROSS THE MID/UPPER MISSISSIPPI VALLEY. MID LEVEL
THERMAL RIBBON WILL SET UP FROM THE DAKOTAS SOUTHEAST INTO THE MID
MISSISSIPPI VALLEY WITH ISENTROPIC ASCENT RESULTING IN PRECIPITATION
WHICH APPEARS WILL BE FOCUSED JUST TO OUR WEST MONDAY...THOUGH
GUIDANCE CONTINUES TO STRUGGLE LOCKING ONTO DETAILS. THERE MAY BE A
SUBTLE WAVE THAT MOVES ACROSS THE AREA...WHICH ECMWF AND NAM SUGGEST
WILL BRING LIGHT PRECIP TO THE AREA EARLY MONDAY. PRETTY DRY
MIDLEVEL AIRMASS THOUGH MAY BE INSURMOUNTABLE...SO CAPPED POPS AT
SLIGHT CHC MONDAY. THERMAL RIDGE WILL GRADUALLY TRANSLATE ENE MONDAY
NIGHT AND SHOULD EVENTUALLY SPREAD ACROSS THE CWA. MOISTURE
AVAILABILITY STILL A BIG QUESTION MARK WITH RESPECT TO TIMING THE
ONSET OF PRECIPITATION...BUT MORE PERSISTENT FORCING SHOULD
EVENTUALLY SATURATE THE COLUMN. PRECIP SHOULD START AS SNOW...OR
POSSIBLY RAIN SNOW MIX BEFORE TRANSITIONING TO ALL RAIN TUESDAY AS
WE CONTINUE TO WARM THE COLUMN.
WEDNESDAY AND THURSDAY...
ELONGATED SURFACE LOW IS PROGGED TO LIFT NORTHEAST ACROSS THE UPPER
MIDWEST INTO THE NORTHERN LAKES REGION WEDNESDAY INTO THURSDAY. AS
THE WARM FRONT LIFTS NORTH ACROSS THE AREA...CONTINUE TO FEEL THAT
50S MAY OVERSPREAD AT LEAST THE SOUTHERN HALF OF THE CWA IF NOT INTO
THE CHICAGO METRO AREA WEDNESDAY AFTERNOON...DESPITE CLOUD COVER AND
PRECIP CHANCES. LATEST EMCWF TAKES THE 50 ISOTHERM ALL THE WAY TO
THE STATE LINE...AND OFTEN IS ONE OF THE BETTER PERFORMING MODELS
UNDER A THERMAL RIDGE. REMAIN CONSERVATIVE BRINGING THE WARMTH
NORTHWARD...BUT DID TREND TEMPERATURES UP A COUPLE DEGREES FROM
GOING FORECAST.
THERE CONTINUES TO BE CONSIDERABLE SPREAD IN MODEL SOLUTIONS
RESULTING IN LOW CONFIDENCE PARTICULARLY WITH TIMING PRECIP...THOUGH
CONFIDENCE IN WIDESPREAD PRECIP OVERSPREADING THE AREA AT SOME POINT
IS FAIRLY HIGH AS THE WARM CONVEYOR BELT TRANSLATES EAST ACROSS THE
REGION WEDNESDAY/WEDNESDAY NIGHT. A COLD FRONT WILL THEN SWEEP
ACROSS THE AREA LATE WEDNESDAY NIGHT INTO THURSDAY WITH PRECIP
CHANGING OVER TO SNOW BRIEFLY BEFORE ENDING. AT THIS POINT DO NOT
ANTICIPATE ANY ACCUMULATIONS WITH THE BULK OF THE PRECIP LIQUID.
LEANED HEAVILY ON BLEND OF EMCWF AND GEM GUIDANCE FOR TIMING POPS
WHICH WERE BETTER CLUSTERED COMPARED TO THE MUCH FASTER GFS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WEAK COLD FRONT WILL TURN WINDS FROM SW TO NNW LATE TONIGHT.
* MVFR CIG WILL LIKELY DEVELOP BEHIND COLD FRONT SUNDAY MORNING
AND PERSIST THROUGH THE DAY SUNDAY.
ALLSOPP
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE WAS OVER NEW ENGLAND AND WEAK LOW PRESSURE WAS OVER
LAKE SUPERIOR AT MIDDAY...WITH A COLD FRONT TRAILING THROUGH
NORTHWEST WISCONSIN AND IOWA. SOUTHWEST FLOW AHEAD OF THE FRONT
WAS BRINGING MILD DRY AIR TO THE REGION. A FAIRLY SHALLOW
INVERSION IS IN PLACE BUT WITH FULL SUN THERE IS ENOUGH MIXING FOR
A FEW GUSTS IN THE MID TO UPPER TEENS THIS AFTERNOON. LATE THIS
AFTERNOON WITH LOSS OF HEATING AND MIXING...WINDS AND GUSTS WILL
DIMINISH. WINDS WILL GRADUALLY VEER FROM SSW TO SW TO WSW THROUGH
THE EVENING HOURS AS THE FRONT APPROACHES. WINDS WILL BE LIGHT AS
THE WEAK FRONT SLIPS THROUGH THE AREA. NEW SHORT RANGE MODELS ALL
VERY SIMILAR IN TIMING OF THE FRONTAL PASSAGE THROUGH THE
TERMINALS. WINDS WILL QUICKLY SHIFT TO NW BEHIND THE FRONT...THEN
GRADUALLY CONTINUE TO COME AROUND TO NNE DURING THE DAY SUNDAY.
MAIN CONCERN IS FOR THE POTENTIAL OF MVFR CIG AND SOME LIGHT FOG
AND HAZE IN THE EARLY MORNING BEHIND THE FRONT. NAM AND LOCAL ARW
MOST AGGRESSIVE IN MOISTENING LOWEST PART OF SOUNDING. THIS WOULD
SUGGEST CIGS AT OR BELOW 1000 FT WITH SOME FOG AND HAZE. GFS KEEPS
INVERSION AROUND 2500 FT. TIMING OF STRATUS COULD BE DELAYED A FEW
HOURS AFTER FROPA. FOR NOW WILL CONTINUE TREND OF PREVIOUS
FORECAST WITH CIGS AROUND 2K FT AFTER FROPA.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM TO HIGH CONFIDENCE IN MVFR CIG DEVELOPING BUT LOW
CONFIDENCE IN TIMING AND HEIGHT OF CIG.
ALLSOPP
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR...THOUGH MVFR CIGS POSSIBLE.
MONDAY INTO TUESDAY...MVFR CIGS POSSIBLE. SLIGHT CHANCE -RASN.
WEDNESDAY...MVFR CIGS PROBABLE CHANCE OF IFR. CHANCE OF RAIN.
THURSDAY...MVFR CIGS PROBABLE. CHANCE -RASN.
FRIDAY...VFR.
RATZER
&&
.MARINE...
302 AM CST
MAIN MARINE FORECAST CONCERNS ARE STRONG SOUTH WINDS AND GALES ON
THE NORTHERN PART OF THE LAKE THIS MORNING...AND TIMING OF A STRONG
LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE WESTERN GREAT LAKES
REGION TOWARD THE MIDDLE OF NEXT WEEK.
STRONG HIGH PRESSURE WAS OVER NEW ENGLAND THIS MORNING...AND WILL
MOVE SLOWLY EAST OFF OF THE ATLANTIC COAST TODAY. LOW PRESSURE OVER
THE DAKOTAS WILL TRACK EAST ACROSS LAKE SUPERIOR TODAY...THEN
SOUTHEAST ACROSS THE EASTERN LAKES TONIGHT. IN THE PROCESS...A COLD
FRONT TRAILING FROM THIS LOW WILL MOVE SOUTHEAST ACROSS LAKE
MICHIGAN LATE THIS AFTERNOON AND TONIGHT. WITH THE STRONG HIGH TO
THE EAST AND THE LOW PASSING TO THE NORTH...THE SURFACE PRESSURE
GRADIENT HAS TIGHTENED AND WAS PRODUCING SOUTH WINDS 30-35 KT ACROSS
THE NORTHERN PART OF THE LAKE...AND NEAR 30 KT SOUTH. THIS WILL
CONTINUE THROUGH THE MID-MORNING HOURS TODAY...BEFORE THE GRADIENT
WEAKENS WITH THE APPROACH OF THE LOW AND COLD FRONTAL TROUGH. THIS
WILL ALLOW WINDS TO DIMINISH...EVENTUALLY VEERING TO THE NORTH
BEHIND THE COLD FRONT AND THEN BECOMING NORTH-NORTHEAST ON SUNDAY.
HIGH PRESSURE WILL THEN SPREAD EAST ACROSS ONTARIO AND QUEBEC SUNDAY
INTO MONDAY...WITH WEAKER RIDGING EXTENDING ACROSS THE WESTERN
LAKES. A LARGE AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OVER THE
NORTHERN HIGH PLAINS MONDAY...DEEPENING AND SLOWLY MOVING EAST
TOWARD THE LAKES THROUGH MID-WEEK. MODEST EAST-NORTHEAST WINDS NEAR
THE SURFACE HIGH PRESSURE RIDGE WILL EVENTUALLY BECOME MORE
EAST-SOUTHEAST AND INCREASE AS THE LOW APPROACHES TUESDAY NIGHT AND
WEDNESDAY.
FOR THE ILLINOIS AND INDIANA NEAR SHORE WATERS...SOUTH WINDS GUSTING
20-25 KT THIS MORNING ARE LIKELY PRODUCING WAVES OF 4+ FT NORTH
OF DOWNTOWN CHICAGO. THEREFORE HAVE ISSUED A SMALL CRAFT ADVISORY
FOR THAT PART OF THE IL SHORE THROUGH MID-MORNING. WINDS BECOMING
SOUTHWEST WILL ALLOW WAVES TO SUBSIDE BELOW SMALL CRAFT ADVISORY
CRITERIA AFTER THAT TIME.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1149 AM CST Sat Nov 30 2013
.DISCUSSION...
ISSUED 1057 AM CST Sat Nov 30 2013
High pressure sliding to the east this morning and southerly flow
setting up over Central Illinois. Temperatures are warming up
faster than the diurnal trend and have boosted highs a degree or
two as well as adjusted the hourlys and the sky grids for more
sunshine. Overall subtle adjustments, but will send out an update
to cover the few changes.
&&
.AVIATION...
ISSUED 1105 AM CST Sat Nov 30 2013
High pressure sliding to the east giving way to increasing RH in
the region resulting in a troublesome forecast for the overnight
hours in ILX terminals. NAM has far more moisture trapped in the
boundary layer and guidance resulting in everything from MVFR vis
to LIFR cigs and vis. GFS in the same shape with less moisture and
the HRRR is a little slower and more conservative but still
moisture laden particularly NW of the Illinois River Valley.
Trouble is, lower res models have increased moisture already in
central MO, and sat imagery pointing to an overdone model run.
That being said, dewpoints are on the increase with swrly flow.
HRRR depiction of sfc RH a little more on track and def
highlighting overnight NW of the IL river. Trouble is whether or
not we are looking at stratus developing or vis drop. Not to
mention that if enough moisture makes it into the SE and does not
mix out this afternoon, chance for reduced vis in the SE as the
skies clear out a bit tonight. For now, forecast conservative, but
starting the trend for a visibility drop with majority rule to a
cloud deck in the 4000 to 5000 ft range for PIA BMI and SPI this
evening and through the overnight.
HJS
&&
.PREV DISCUSSION...
ISSUED 227 AM CST Sat Nov 30 2013
Main forecast challenge focuses on departing storm system for the
middle and end of next week...and whether or not it will produce
any wintry precipitation across central Illinois.
SHORT TERM...Today through Monday
Mild and quiet weather will prevail through the short-term.
Increasing southerly winds on the back-side of high pressure
anchored along the East Coast will bring above normal temperatures
back into the area today. Despite a chilly start to the day, the
southerly flow coupled with ample afternoon sunshine will boost
highs into the middle to upper 40s, with a few locations across
the S/SW KILX CWA potentially reaching the 50 degree mark. A weak
cold front will sag southward into the area on Sunday, bringing a
few clouds and a shift in the winds. Thanks to northerly winds
behind the boundary across the northern half of the CWA,
temperatures will be a couple of degrees cooler than today.
Front will become parallel to the zonal upper-level flow and will
stall across the Ohio River Valley Sunday night into Monday. As
Gulf moisture continues to flow northward over the boundary and a
short-wave trough ripples eastward out of the Plains, a few light
rain showers may develop on Monday. Several of the operational
models are hinting at this, so have included a 20 POP accordingly.
LONG TERM...Tuesday through Friday
Main show will hold off until the extended, as an upper-level low
currently over Alaska sinks southward and carves out a long-wave
trough across the western CONUS by the middle of the week.
Downstream ridging will produce deep southwesterly flow over the
Midwest, resulting in cloudy skies and increasing precip chances
Wednesday into Thursday. Model spread is still significant, so
exact evolution of the developing storm system is uncertain at
this time. General consensus develops surface low pressure in the
lee of the Rockies, then tracks it northeastward into Canada by
Thursday. Trailing cold front will likely push through Illinois
Wednesday night into Thursday, triggering scattered showers and
perhaps a thunderstorm. Things get tricky once the front passes
and the colder air begins to arrive Thursday into Friday. 00z Nov
30 GFS/GEM both show front quickly advancing eastward, with precip
largely ending before the cold airmass spreads into the area. This
would tend to support a brief change-over to light snow Thursday
night as the front slides eastward into Indiana before the precip
comes to an end on Friday. Meanwhile, the 00z ECMWF suggests much
more precip will hang back in the cold air Thursday night,
followed by another wave of low pressure riding along the boundary
and a renewed round of precip in the cold airmass on Friday. This
could lead to a much more wintry scenario, with rain changing to
snow Thursday night and another chance for snow on Friday. At this
point, will trend toward the GFS/GEM consensus. As a result, will
mention a rain/snow mix west of the Illinois River as early as
Thursday, with rain changing to light snow further east to the
Indiana border Thursday night. Will go with a mainly dry forecast
for Friday, but will hold on to a chance for rain/snow across the
far E/SE CWA in case secondary wave does indeed develop along
departing front. Once this system exits the region, much colder
weather will be on tap for the end of the week.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
228 PM EST SAT NOV 30 2013
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 328 AM EST SAT NOV 30 2013
AFTER A MAINLY SUNNY DAY...CLOUDS WILL INCREASE ACROSS THE OHIO
VALLEY FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK AS A
WEAK FRONT SLIDES INTO THE REGION. A FEW LIGHT RAIN SHOWERS OR
SPRINKLES WILL BE POSSIBLE FROM SUNDAY AFTERNOON THROUGH MONDAY AS A
COUPLE OF WEAK WAVE ALOFT MOVE ACROSS THE OHIO VALLEY. A MUCH BETTER
CHANCE FOR RAIN WILL COME FOR THE SECOND HALF OF THE WEEK AS A
STRONG COLD FRONT TRACKS THROUGH THE REGION. COLDER AIR WILL ONCE
AGAIN RETURN BY THE END OF THE WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 954 AM EST SAT NOV 30 2013
UPDATE...
SOME MID/HIGH CLOUDS WERE STILL ACROSS OUR FAR EAST...BUT HAVE
CLEARED OUT ELSEWHERE. UPSTREAM SKIES WERE CLEAR AND WILL SCALE
BACK CLOUD COVER A LITTLE WITH MOST AREAS BEING SUNNY THIS
AFTERNOON.
ONLY OTHER CHANGE WAS TO TWEAK TEMPERATURES UP A DEGREE SOME AREAS
BASED ON 12Z RUC 2 METER TEMPERATURES...LOTS OF SUNSHINE AND WARM
ADVECTION. ALL IN ALL THE CURRENT FORECAST IS ON TRACK.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
MID AND HIGH LEVEL CLOUD COVER DRAPED ACROSS MUCH OF THE OHIO VALLEY
EARLY THIS MORNING AS A WEAK WAVE ALOFT TRACKS ACROSS THE AREA.
TEMPS WERE MAINLY IN THE 20S AT 08Z.
BACK EDGE OF THE MORE SUBSTANTIAL HIGHER CLOUDS IS ALREADY EAST OF
THE MISSISSIPPI RIVER EARLY THIS MORNING. EXPECT CLOUDS TO DIMINISH
FROM WEST TO EAST ACROSS THE FORECAST AREA AROUND OR SHORTLY AFTER
DAYBREAK...WITH SKIES THEN BECOMING MOSTLY SUNNY WITH ONLY PATCHY
CIRRUS FOR THE REST OF THE DAY.
WITH THE BROAD HIGH PRESSURE RIDGE NOW LOCATED EAST OF THE
REGION...RETURN SOUTHERLY FLOW WILL DEVELOP AND INCREASE BY THIS
AFTERNOON AS BOUNDARY LAYER FLOW STRENGTHENS AHEAD OF AN APPROACHING
COLD FRONT. MODEL SOUNDINGS SUPPORT MAX GUSTS TO 20-25MPH BY THE
AFTERNOON AS LOW LEVEL MIXING INCREASES. GUSTS WILL DROP OFF NEAR
SUNSET AS THE NOCTURNAL INVERSION ESTABLISHES.
TEMPS...SOUTHERLY FLOW AND WARM ADVECTION WILL BRING WARMER TEMPS
INTO CENTRAL INDIANA FOR TODAY. MOS GUIDANCE MATCHES UP NICELY WITH
LOW LEVEL THERMALS...WITH HIGHS TOPPING OUT NEAR LATE NOVEMBER
NORMALS IN THE MID/UPPER 40S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 328 AM EST SAT NOV 30 2013
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR LIGHT PRECIP AS THE
AFOREMENTIONED COLD FRONT DROPS INTO THE REGION...STALLS AND
EVENTUALLY WASHES OUT.
PREDOMINANT ZONAL FLOW IN THE UPPER LEVELS WILL BE PRESENT THROUGH
THE PERIOD WITH SEVERAL WEAK WAVES ALOFT TRACKING QUICKLY THROUGH
THE OHIO VALLEY. AT THE SURFACE...THE COLD FRONT WILL SLIDE SLOWLY
SOUTH INTO THE REGION ON SUNDAY...EVENTUALLY STALLING OUT OVER
SOUTHERN INDIANA SUNDAY NIGHT BEFORE WASHING OUT MONDAY. MOISTURE
ACCOMPANYING THE FRONT WILL BE LIMITED...BUT MODEL SOUNDINGS AND RH
PROGS CONTINUE TO SHOW IT IN GREATEST ABUNDANCE IN THE UPPER
PORTIONS OF THE BOUNDARY LAYER BEGINNING EARLY SUNDAY...GRADUALLY
LOWERING TO AROUND 2-3KFT INTO MONDAY AS AN INVERSION STEADILY
STRENGTHENS.
EXPECT CLOUDS TO EXPAND SOUTHEAST INTO THE FORECAST AREA AHEAD OF
THE FRONT BEGINNING LATE TONIGHT AND CONTINUING INTO SUNDAY. WEAK
ISENTROPIC LIFT AND A SUBTLE WAVE ALOFT MAY BE JUST ENOUGH TO
GENERATE SOME LIGHT PRECIP SUNDAY AFTERNOON AND NIGHT...LIKELY IN
THE FORM OF SPRINKLES...DRIZZLE OR VERY LIGHT RAIN SHOWERS. LOW
LEVELS AND SURFACE TEMPS SHOULD REMAIN WARM ENOUGH TO SUPPORT PRECIP
TYPE AS RAIN ONLY SUNDAY NIGHT. MODEL GUIDANCE LARGELY IN AGREEMENT
ON BRINGING A SLIGHTLY STRONGER...BETTER PHASED UPPER WAVE ACROSS
THE OHIO VALLEY ON MONDAY. WITH LOW LEVEL MOISTURE IN ABUNDANCE...
THIS FEATURE SHOULD PRESENT A BETTER OPPORTUNITY FOR A FEW LIGHT
RAIN SHOWERS. WILL CARRY JUST LOW CHANCE POPS HOWEVER AS ISENTROPIC
LIFT REMAINS WEAK. MAJORITY OF THE MODEL GUIDANCE FAVORING THE
PASSAGE OF THIS UPPER WAVE BY MONDAY EVENING...AND WILL END PRECIP
CHANCES AS RIDGING ALOFT EXPANDS INTO THE OHIO VALLEY BY EARLY
TUESDAY.
TEMPS...CONSIDERING THE INCREASING CLOUDS AND POTENTIAL FOR WEAK
COLD ADVECTION TO DEVELOP ON SUNDAY...METMOS TEMPS IN THE UPPER
40S/LOWER 50S LOOK RATHER AGGRESSIVE. HAVE TRENDED CLOSER TO /BUT
NOT AS COLD AS/ THE MAVMOS FOR SUNDAY HIGHS. LEANED TOWARDS THE
MAVMOS AGAIN FOR MONDAY WITH LIGHT RAIN/CLOUDS PRESENT. NEAR MAVMOS
FOR LOWS TONIGHT...THEN TRENDED TOWARDS THE WARMER METMOS FOR SUNDAY
NIGHT WITH EXPECTED CLOUD COVER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 228 PM EST SAT NOV 30 2013
MODELS ARE CLOSE ENOUGH FOR THE MOST PART INTO THURSDAY...BUT DIFFER
IN PRECIPITATION SIGNIFICANTLY ON FRIDAY. UNCERTAINTY IS HIGH SO
GENERALLY STUCK CLOSE TO THE ALLBLEND INITIALIZATION FOR MOST ITEMS.
THERE IS SOME UNCERTAINTY ON LIGHT RAIN DEVELOPMENT IN THE WARM
ADVECTION PATTERN AHEAD OF THE ARCTIC FRONT TUESDAY NIGHT INTO
WEDNESDAY. WITH ONLY LOW CHANCES FOR RAIN DECIDED TO KEEP CONTINUITY
WITH PREVIOUS FORECAST AND GO DRY TUESDAY NIGHT AND SLIGHT CHANCE
POPS FOR WEDNESDAY.
CHANCES FOR RAIN THEN INCREASE INTO THURSDAY WITH LIKELY POPS
THURSDAY AND THURSDAY NIGHT. ARCTIC FRONT SHOULD HAVE PLENTY OF
MOISTURE TO WORK WITH DURING THIS PERIOD.
QUESTIONS THEN ARISE FOR POPS ON FRIDAY. 00Z AND 12Z ECMWF KEEP
PRECIPITATION ACROSS THE AREA AS A WAVE RIDES ALONG THE FRONT. GFS
KEEPS WAVE FARTHER SOUTHEAST SO OUR AREA REMAINS DRY. SOME GFS
ENSEMBLES ARE CLOSER TO THE ECMWF SOLUTION. 12Z CANADIAN WOULD
APPEAR TO SUPPORT ECMWF AS WELL.
THEREFORE KEPT HIGH CHANCE CATEGORY POPS FRIDAY WITH LOWER POPS
FRIDAY NIGHT. THERMAL PROFILES INDICATE A MIX OF RAIN AND SNOW
FRIDAY WITH SNOW FRIDAY NIGHT AS THE ARCTIC AIR MOVES IN.
SATURDAY LOOKS TO BE VERY COLD AND DRY WITH ARCTIC HIGH MOVING IN.
BEFORE THE ARCTIC FRONT ARRIVES THURSDAY EXPECT ABOVE NORMAL
TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 301800Z TAF ISSUANCE/...
ISSUED AT 1159 AM EST SAT NOV 30 2013
VFR EXPECTED THROUGH THE PERIOD...ALTHOUGH CONFIDENCE LOWERS AFTER
12Z SUNDAY.
WINDS COULD BRIEFLY GUST TO NEAR 15KT THIS AFTERNOON BUT MOST OF THE
TIME WINDS WILL BE LESS THAN 10KT UNDER JUST SOME HIGH CLOUDS.
LOW LEVEL MOISTURE INCREASES AHEAD OF A COLD FRONT TONIGHT SO ADDED
A CEILING AROUND BKN060 AFTER 06Z.
MODELS ARE TRYING TO HINT AT EVEN LOWER CEILINGS AFTER 12Z SUNDAY.
CONFIDENCE IS NOT HIGH IN THIS SCENARIO...BUT ODDS ARE GETTING
BETTER WITH EACH RUN. THEREFORE WILL LOWER CEILINGS TO LOW END OF
VFR FOR NOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN
LONG TERM....50
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1159 AM EST SAT NOV 30 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 328 AM EST SAT NOV 30 2013
AFTER A MAINLY SUNNY DAY...CLOUDS WILL INCREASE ACROSS THE OHIO
VALLEY FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK AS A
WEAK FRONT SLIDES INTO THE REGION. A FEW LIGHT RAIN SHOWERS OR
SPRINKLES WILL BE POSSIBLE FROM SUNDAY AFTERNOON THROUGH MONDAY AS A
COUPLE OF WEAK WAVE ALOFT MOVE ACROSS THE OHIO VALLEY. A MUCH BETTER
CHANCE FOR RAIN WILL COME FOR THE SECOND HALF OF THE WEEK AS A
STRONG COLD FRONT TRACKS THROUGH THE REGION. COLDER AIR WILL ONCE
AGAIN RETURN BY THE END OF THE WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 954 AM EST SAT NOV 30 2013
UPDATE...
SOME MID/HIGH CLOUDS WERE STILL ACROSS OUR FAR EAST...BUT HAVE
CLEARED OUT ELSEWHERE. UPSTREAM SKIES WERE CLEAR AND WILL SCALE
BACK CLOUD COVER A LITTLE WITH MOST AREAS BEING SUNNY THIS
AFTERNOON.
ONLY OTHER CHANGE WAS TO TWEAK TEMPERATURES UP A DEGREE SOME AREAS
BASED ON 12Z RUC 2 METER TEMPERATURES...LOTS OF SUNSHINE AND WARM
ADVECTION. ALL IN ALL THE CURRENT FORECAST IS ON TRACK.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
MID AND HIGH LEVEL CLOUD COVER DRAPED ACROSS MUCH OF THE OHIO VALLEY
EARLY THIS MORNING AS A WEAK WAVE ALOFT TRACKS ACROSS THE AREA.
TEMPS WERE MAINLY IN THE 20S AT 08Z.
BACK EDGE OF THE MORE SUBSTANTIAL HIGHER CLOUDS IS ALREADY EAST OF
THE MISSISSIPPI RIVER EARLY THIS MORNING. EXPECT CLOUDS TO DIMINISH
FROM WEST TO EAST ACROSS THE FORECAST AREA AROUND OR SHORTLY AFTER
DAYBREAK...WITH SKIES THEN BECOMING MOSTLY SUNNY WITH ONLY PATCHY
CIRRUS FOR THE REST OF THE DAY.
WITH THE BROAD HIGH PRESSURE RIDGE NOW LOCATED EAST OF THE
REGION...RETURN SOUTHERLY FLOW WILL DEVELOP AND INCREASE BY THIS
AFTERNOON AS BOUNDARY LAYER FLOW STRENGTHENS AHEAD OF AN APPROACHING
COLD FRONT. MODEL SOUNDINGS SUPPORT MAX GUSTS TO 20-25MPH BY THE
AFTERNOON AS LOW LEVEL MIXING INCREASES. GUSTS WILL DROP OFF NEAR
SUNSET AS THE NOCTURNAL INVERSION ESTABLISHES.
TEMPS...SOUTHERLY FLOW AND WARM ADVECTION WILL BRING WARMER TEMPS
INTO CENTRAL INDIANA FOR TODAY. MOS GUIDANCE MATCHES UP NICELY WITH
LOW LEVEL THERMALS...WITH HIGHS TOPPING OUT NEAR LATE NOVEMBER
NORMALS IN THE MID/UPPER 40S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 328 AM EST SAT NOV 30 2013
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR LIGHT PRECIP AS THE
AFOREMENTIONED COLD FRONT DROPS INTO THE REGION...STALLS AND
EVENTUALLY WASHES OUT.
PREDOMINANT ZONAL FLOW IN THE UPPER LEVELS WILL BE PRESENT THROUGH
THE PERIOD WITH SEVERAL WEAK WAVES ALOFT TRACKING QUICKLY THROUGH
THE OHIO VALLEY. AT THE SURFACE...THE COLD FRONT WILL SLIDE SLOWLY
SOUTH INTO THE REGION ON SUNDAY...EVENTUALLY STALLING OUT OVER
SOUTHERN INDIANA SUNDAY NIGHT BEFORE WASHING OUT MONDAY. MOISTURE
ACCOMPANYING THE FRONT WILL BE LIMITED...BUT MODEL SOUNDINGS AND RH
PROGS CONTINUE TO SHOW IT IN GREATEST ABUNDANCE IN THE UPPER
PORTIONS OF THE BOUNDARY LAYER BEGINNING EARLY SUNDAY...GRADUALLY
LOWERING TO AROUND 2-3KFT INTO MONDAY AS AN INVERSION STEADILY
STRENGTHENS.
EXPECT CLOUDS TO EXPAND SOUTHEAST INTO THE FORECAST AREA AHEAD OF
THE FRONT BEGINNING LATE TONIGHT AND CONTINUING INTO SUNDAY. WEAK
ISENTROPIC LIFT AND A SUBTLE WAVE ALOFT MAY BE JUST ENOUGH TO
GENERATE SOME LIGHT PRECIP SUNDAY AFTERNOON AND NIGHT...LIKELY IN
THE FORM OF SPRINKLES...DRIZZLE OR VERY LIGHT RAIN SHOWERS. LOW
LEVELS AND SURFACE TEMPS SHOULD REMAIN WARM ENOUGH TO SUPPORT PRECIP
TYPE AS RAIN ONLY SUNDAY NIGHT. MODEL GUIDANCE LARGELY IN AGREEMENT
ON BRINGING A SLIGHTLY STRONGER...BETTER PHASED UPPER WAVE ACROSS
THE OHIO VALLEY ON MONDAY. WITH LOW LEVEL MOISTURE IN ABUNDANCE...
THIS FEATURE SHOULD PRESENT A BETTER OPPORTUNITY FOR A FEW LIGHT
RAIN SHOWERS. WILL CARRY JUST LOW CHANCE POPS HOWEVER AS ISENTROPIC
LIFT REMAINS WEAK. MAJORITY OF THE MODEL GUIDANCE FAVORING THE
PASSAGE OF THIS UPPER WAVE BY MONDAY EVENING...AND WILL END PRECIP
CHANCES AS RIDGING ALOFT EXPANDS INTO THE OHIO VALLEY BY EARLY
TUESDAY.
TEMPS...CONSIDERING THE INCREASING CLOUDS AND POTENTIAL FOR WEAK
COLD ADVECTION TO DEVELOP ON SUNDAY...METMOS TEMPS IN THE UPPER
40S/LOWER 50S LOOK RATHER AGGRESSIVE. HAVE TRENDED CLOSER TO /BUT
NOT AS COLD AS/ THE MAVMOS FOR SUNDAY HIGHS. LEANED TOWARDS THE
MAVMOS AGAIN FOR MONDAY WITH LIGHT RAIN/CLOUDS PRESENT. NEAR MAVMOS
FOR LOWS TONIGHT...THEN TRENDED TOWARDS THE WARMER METMOS FOR SUNDAY
NIGHT WITH EXPECTED CLOUD COVER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 328 AM EST SAT NOV 30 2013
ENSEMBLES ARE IN GOOD AGREEMENT ON THE EVOLVING WEATHER PATTERN NEXT
WEEK. UPPER RIDGING EXPECTED TO DEVELOP ALONG THE EAST COAST AS A
TROUGH SETS UP FROM THE NORTHERN MIDWEST BACK INTO THE SOUTHERN
ROCKIES. THIS WILL RESULT IN SOUTHWESTERLY UPPER FLOW LOCALLY.
APPEARS A DECENT CHUNK OF ENERGY WILL EJECT OUT OF THE WESTERN
TROUGH INTO WESTERN GREAT LAKES AROUND NEXT THURSDAY. WILL KEEP POPS
IN THE FORECAST FOR RAIN ON WEDNESDAY AND ESPECIALLY THURSDAY AS THE
UPPER DISTURBANCE MOVES THROUGH.
SEVERAL ENSEMBLES SUGGEST MORE ENERGY MAY EJECT OUT ACROSS THE OHIO
OR TENNESSEE VALLEY AROUND NEXT FRIDAY...WHICH MAY INDUCE A SURFACE
WAVE ON THE PRIMARY COLD FRONT. WILL GO WITH CHANCE POPS FOR RAIN OR
SNOW AT THAT TIME. AT THIS POINT...THE ENSEMBLES INDICATE ANY SNOW
ACCUMULATIONS LATE NEXT WEEK WILL BE MINOR.
&&
.AVIATION /DISCUSSION FOR THE 301800Z TAF ISSUANCE/...
ISSUED AT 1159 AM EST SAT NOV 30 2013
VFR EXPECTED THROUGH THE PERIOD...ALTHOUGH CONFIDENCE LOWERS AFTER
12Z SUNDAY.
WINDS COULD BRIEFLY GUST TO NEAR 15KT THIS AFTERNOON BUT MOST OF THE
TIME WINDS WILL BE LESS THAN 10KT UNDER JUST SOME HIGH CLOUDS.
LOW LEVEL MOISTURE INCREASES AHEAD OF A COLD FRONT TONIGHT SO ADDED
A CEILING AROUND BKN060 AFTER 06Z.
MODELS ARE TRYING TO HINT AT EVEN LOWER CEILINGS AFTER 12Z SUNDAY.
CONFIDENCE IS NOT HIGH IN THIS SCENARIO...BUT ODDS ARE GETTING
BETTER WITH EACH RUN. THEREFORE WILL LOWER CEILINGS TO LOW END OF
VFR FOR NOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
954 AM EST SAT NOV 30 2013
.UPDATE...
NEAR TERM FOR THE REST OF TODAY HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 328 AM EST SAT NOV 30 2013
AFTER A MAINLY SUNNY DAY...CLOUDS WILL INCREASE ACROSS THE OHIO
VALLEY FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK AS A
WEAK FRONT SLIDES INTO THE REGION. A FEW LIGHT RAIN SHOWERS OR
SPRINKLES WILL BE POSSIBLE FROM SUNDAY AFTERNOON THROUGH MONDAY AS A
COUPLE OF WEAK WAVE ALOFT MOVE ACROSS THE OHIO VALLEY. A MUCH BETTER
CHANCE FOR RAIN WILL COME FOR THE SECOND HALF OF THE WEEK AS A
STRONG COLD FRONT TRACKS THROUGH THE REGION. COLDER AIR WILL ONCE
AGAIN RETURN BY THE END OF THE WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 954 AM EST SAT NOV 30 2013
UPDATE...
SOME MID/HIGH CLOUDS WERE STILL ACROSS OUR FAR EAST...BUT HAVE
CLEARED OUT ELSEWHERE. UPSTREAM SKIES WERE CLEAR AND WILL SCALE
BACK CLOUD COVER A LITTLE WITH MOST AREAS BEING SUNNY THIS
AFTERNOON.
ONLY OTHER CHANGE WAS TO TWEAK TEMPERATURES UP A DEGREE SOME AREAS
BASED ON 12Z RUC 2 METER TEMPERATURES...LOTS OF SUNSHINE AND WARM
ADVECTION. ALL IN ALL THE CURRENT FORECAST IS ON TRACK.
PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
MID AND HIGH LEVEL CLOUD COVER DRAPED ACROSS MUCH OF THE OHIO VALLEY
EARLY THIS MORNING AS A WEAK WAVE ALOFT TRACKS ACROSS THE AREA.
TEMPS WERE MAINLY IN THE 20S AT 08Z.
BACK EDGE OF THE MORE SUBSTANTIAL HIGHER CLOUDS IS ALREADY EAST OF
THE MISSISSIPPI RIVER EARLY THIS MORNING. EXPECT CLOUDS TO DIMINISH
FROM WEST TO EAST ACROSS THE FORECAST AREA AROUND OR SHORTLY AFTER
DAYBREAK...WITH SKIES THEN BECOMING MOSTLY SUNNY WITH ONLY PATCHY
CIRRUS FOR THE REST OF THE DAY.
WITH THE BROAD HIGH PRESSURE RIDGE NOW LOCATED EAST OF THE
REGION...RETURN SOUTHERLY FLOW WILL DEVELOP AND INCREASE BY THIS
AFTERNOON AS BOUNDARY LAYER FLOW STRENGTHENS AHEAD OF AN APPROACHING
COLD FRONT. MODEL SOUNDINGS SUPPORT MAX GUSTS TO 20-25MPH BY THE
AFTERNOON AS LOW LEVEL MIXING INCREASES. GUSTS WILL DROP OFF NEAR
SUNSET AS THE NOCTURNAL INVERSION ESTABLISHES.
TEMPS...SOUTHERLY FLOW AND WARM ADVECTION WILL BRING WARMER TEMPS
INTO CENTRAL INDIANA FOR TODAY. MOS GUIDANCE MATCHES UP NICELY WITH
LOW LEVEL THERMALS...WITH HIGHS TOPPING OUT NEAR LATE NOVEMBER
NORMALS IN THE MID/UPPER 40S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
ISSUED AT 328 AM EST SAT NOV 30 2013
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR LIGHT PRECIP AS THE
AFOREMENTIONED COLD FRONT DROPS INTO THE REGION...STALLS AND
EVENTUALLY WASHES OUT.
PREDOMINANT ZONAL FLOW IN THE UPPER LEVELS WILL BE PRESENT THROUGH
THE PERIOD WITH SEVERAL WEAK WAVES ALOFT TRACKING QUICKLY THROUGH
THE OHIO VALLEY. AT THE SURFACE...THE COLD FRONT WILL SLIDE SLOWLY
SOUTH INTO THE REGION ON SUNDAY...EVENTUALLY STALLING OUT OVER
SOUTHERN INDIANA SUNDAY NIGHT BEFORE WASHING OUT MONDAY. MOISTURE
ACCOMPANYING THE FRONT WILL BE LIMITED...BUT MODEL SOUNDINGS AND RH
PROGS CONTINUE TO SHOW IT IN GREATEST ABUNDANCE IN THE UPPER
PORTIONS OF THE BOUNDARY LAYER BEGINNING EARLY SUNDAY...GRADUALLY
LOWERING TO AROUND 2-3KFT INTO MONDAY AS AN INVERSION STEADILY
STRENGTHENS.
EXPECT CLOUDS TO EXPAND SOUTHEAST INTO THE FORECAST AREA AHEAD OF
THE FRONT BEGINNING LATE TONIGHT AND CONTINUING INTO SUNDAY. WEAK
ISENTROPIC LIFT AND A SUBTLE WAVE ALOFT MAY BE JUST ENOUGH TO
GENERATE SOME LIGHT PRECIP SUNDAY AFTERNOON AND NIGHT...LIKELY IN
THE FORM OF SPRINKLES...DRIZZLE OR VERY LIGHT RAIN SHOWERS. LOW
LEVELS AND SURFACE TEMPS SHOULD REMAIN WARM ENOUGH TO SUPPORT PRECIP
TYPE AS RAIN ONLY SUNDAY NIGHT. MODEL GUIDANCE LARGELY IN AGREEMENT
ON BRINGING A SLIGHTLY STRONGER...BETTER PHASED UPPER WAVE ACROSS
THE OHIO VALLEY ON MONDAY. WITH LOW LEVEL MOISTURE IN ABUNDANCE...
THIS FEATURE SHOULD PRESENT A BETTER OPPORTUNITY FOR A FEW LIGHT
RAIN SHOWERS. WILL CARRY JUST LOW CHANCE POPS HOWEVER AS ISENTROPIC
LIFT REMAINS WEAK. MAJORITY OF THE MODEL GUIDANCE FAVORING THE
PASSAGE OF THIS UPPER WAVE BY MONDAY EVENING...AND WILL END PRECIP
CHANCES AS RIDGING ALOFT EXPANDS INTO THE OHIO VALLEY BY EARLY
TUESDAY.
TEMPS...CONSIDERING THE INCREASING CLOUDS AND POTENTIAL FOR WEAK
COLD ADVECTION TO DEVELOP ON SUNDAY...METMOS TEMPS IN THE UPPER
40S/LOWER 50S LOOK RATHER AGGRESSIVE. HAVE TRENDED CLOSER TO /BUT
NOT AS COLD AS/ THE MAVMOS FOR SUNDAY HIGHS. LEANED TOWARDS THE
MAVMOS AGAIN FOR MONDAY WITH LIGHT RAIN/CLOUDS PRESENT. NEAR MAVMOS
FOR LOWS TONIGHT...THEN TRENDED TOWARDS THE WARMER METMOS FOR SUNDAY
NIGHT WITH EXPECTED CLOUD COVER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 328 AM EST SAT NOV 30 2013
ENSEMBLES ARE IN GOOD AGREEMENT ON THE EVOLVING WEATHER PATTERN NEXT
WEEK. UPPER RIDGING EXPECTED TO DEVELOP ALONG THE EAST COAST AS A
TROUGH SETS UP FROM THE NORTHERN MIDWEST BACK INTO THE SOUTHERN
ROCKIES. THIS WILL RESULT IN SOUTHWESTERLY UPPER FLOW LOCALLY.
APPEARS A DECENT CHUNK OF ENERGY WILL EJECT OUT OF THE WESTERN
TROUGH INTO WESTERN GREAT LAKES AROUND NEXT THURSDAY. WILL KEEP POPS
IN THE FORECAST FOR RAIN ON WEDNESDAY AND ESPECIALLY THURSDAY AS THE
UPPER DISTURBANCE MOVES THROUGH.
SEVERAL ENSEMBLES SUGGEST MORE ENERGY MAY EJECT OUT ACROSS THE OHIO
OR TENNESSEE VALLEY AROUND NEXT FRIDAY...WHICH MAY INDUCE A SURFACE
WAVE ON THE PRIMARY COLD FRONT. WILL GO WITH CHANCE POPS FOR RAIN OR
SNOW AT THAT TIME. AT THIS POINT...THE ENSEMBLES INDICATE ANY SNOW
ACCUMULATIONS LATE NEXT WEEK WILL BE MINOR.
&&
.AVIATION /DISCUSSION FOR THE 301500Z TAF UPDATE/...
ISSUED AT 920 AM EST SAT NOV 30 2013
KIND TAF LOOKS GOOD. ONLY MINOR TWEAKS MADE.
PREVIOUS DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER...UNRESTRICTED VISIBILITY...SURFACE WINDS
AT OR BELOW 10 KTS EXPECTED AT THE TAF SITES THROUGH 010000Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...JAS/50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS JACKSON KY
929 PM EST SUN DEC 1 2013
.UPDATE...
ISSUED AT 929 PM EST SUN DEC 1 2013
CLOUDY SKIES WILL PREVAIL DURING THE OVERNIGHT. DRIZZLE IS LOOKING
LESS LIKELY FOR LATE TONIGHT AND EARLY MONDAY MORNING...BUT WILL LEAVE
IT IN THE FORECAST FOR THE SAKE OF CONTINUITY AND CONSISTENCY. HAVE
UPDATED HOURLY NDFD AND WEB FORECASTS BASED ON LATEST TRENDS...AND
MADE A FEW MINOR TEMPERATURE ADJUSTMENTS FOR OVERNIGHT LOWS. NEEDED
TO LOWER MINIMUMS IN SOME VALLEY LOCATIONS WHERE TEMPERATURES ONLY
REACHED THE LOWER 40S ON SUNDAY. THE MESONET AT QUICKSAND IS PROBABLY
THE EXTREME EXAMPLE OF THIS WHERE THE AFTERNOON HIGH WAS ONLY 41 AND
THE 02Z TEMPERATURE WAS 37. THIS IS CONTRASTED TO THE JACKSON
ASOS...ONLY 4 MILES AWAY...WHERE THE HIGH WAS 47 AND THE 02Z TEMPERATURE
WAS 47. NO UPDATE NEEDED FOR THE ZFP AT THIS TIME.
UPDATE ISSUED AT 636 PM EST SUN DEC 1 2013
LOW CLOUDS CONTINUE TO HOLD ACROSS THE AREA...AND WILL LIMIT
TEMPERATURE FALLS THIS EVENING. THE PREVIOUS FORECAST HAD THIS WELL
HANDLED. NDFD WAS UPDATED FOR LATEST HOURLY TRENDS BUT THIS RESULTED
IN ONLY MINOR CHANGES TO THE HOURLY NDFD FORECASTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 338 PM EST SUN DEC 1 2013
A BAND OF LOW CLOUDS REMAINS ACROSS THE REGION IN ADVANCE OF A WEAK
COLD FRONT THAT IS BEGINNING TO SLOW DOWN AND STALL OUT. SOME OF
THESE HAVE ERODED A BIT FROM THE SOUTH OR SOUTHEAST AND NORTHWEST
THROUGHOUT THE DAY. THIS HAS LED TO THE COLDEST TEMPERATURES ON
AVERAGE BETWEEN THE HAL ROGERS PARKWAY AND KY HIGHWAY 80 CORRIDOR AND
INTERSTATE 64 CORRIDOR. SOME OF THE DEEPER SHELTERED VALLEYS NEVER
REALLY MIXED OUT AND TEMPERATURES THERE ARE IN THE LOW TO MID 40S
ATTM. OTHERWISE TEMPS WERE NEAR 50 ACROSS MUCH OF THE SOUTHERN CWA
AND HAD NEARED 50 NORTH OF THE INTERSTATE 64 CORRIDOR.
A WEAK DISTURBANCE IS EXPECTED TO MAINLY PASS TO OUR SOUTH LATER
TONIGHT INTO MONDAY MORNING WHILE A MORE NORTHERN SHORTWAVE WILL
PASS TO THE NORTH OF EASTERN KY ON MONDAY AFTERNOON AND EVENING. THIS
WILL LEAD TO A BRIEF DEVELOPMENT OF A SOUTHEASTERN TROUGH BY MONDAY.
THIS TROUGH WILL MOVE ON OFF TO THE EAST WITH SOME WEAK RIDGING
PASSING THROUGH OVER THE SOUTHEASTERN US AND TN VALLEY FOR MON NIGHT
INTO TUE. AT THE END OF THE PERIOD...A TROUGH IS ANTICIPATED TO
EXTEND FROM CENTRAL CANADA INTO THE NORTHERN PLAINS AND THEN
SOUTHWEST INTO THE ROCKIES AND CALIFORNIA WITH MORE OR LESS ZONAL
FLOW IN THE EASTERN CONUS.
AS AT THE SFC...THE BOUNDARY TO OUR NORTHWEST SHOULD STALL NEAR THE
OH RIVER TONIGHT AND INTO MONDAY BEFORE RETURNING NORTH AS A WARM
FRONT LATER ON MONDAY INTO TUESDAY. MODELS INDICATE A GENERAL
GRADUAL INCREASE IN MOISTURE BELOW THE CURRENT CLOUD LAYER
TONIGHT...BUT MEAGER OMEGA AT BEST. UP UNTIL TODAY AT LEAST...MODELS
SEEM TO HAVE BEEN TOO AGGRESSIVE INCREASING LOW LEVEL MOISTURE.
HOWEVER...DEWPOINTS HAVE CREPT UP INTO THE MID TO UPPER 30S IN
WESTERN AND CENTRAL KY AND MIDDLE AND WESTERN TN. THIS LEADS TO
UNCERTAINTY AS TO WHETHER OR NOT THE STRATOCU DECK COULD LOWER LATER
TONIGHT INTO EARLY ON MONDAY AND WHETHER OR NOT THERE COULD BE SOME
PATCHY DRIZZLE AT THAT TIME. THE 12Z NAM AND 12Z GFS HAD SOME LIGHT
SPOTTY QPF WITH THIS LATE TONIGHT OR MONDAY. THE 18Z HRRR ALSO HAD
SOME LIGHT SPOTTY QPF LATER TONIGHT. THE 15Z SREF POPS ARE LOW AND
HAVE TRENDED DOWN SINCE 24 HOURS AGO. OPTED TO GO WITH A 10 POP FOR
PATCHY DRIZZLE IN ALL BUT THE FAR SOUTHEAST LATE TONIGHT AND INTO
MONDAY MORNING AND THEN STAYED CLOSE TO THE PREVIOUS FORECAST FOR
LATER ON MONDAY INTO MONDAY EVENING WITH A SLIGHT CHANCE IN THE FAR
NORTH. THIS LED TO BETTER ISC CONSISTENCY.
WITH LOW CLOUDS EXPECTED FOR MOST...IF NOT ALL OF THE NIGHT...MIN T
TONIGHT WILL BE CONSIDERABLY MILDER IN DEEPER SHELTERED VALLEY
LOCATIONS COMPARED TO RECENT NIGHTS. MIN T SHOULD REMAIN ABOVE
FREEZING IN ALL LOCATIONS. SOME THINNING OF THE CLOUDS IS ANTICIPATED
ON MON AFTERNOON AND TEMPS SHOULD GENERALLY REACH THE LOW TO MID 50S.
MIN T ON MON NIGHT IS A BIT MORE UNCERTAIN...AS SOME OF THE GUIDANCE
SUGGESTS THERE COULD BE WINDOW OF TIME WHERE CLOUDS COULD BE THIN
ENOUGH OR POSSIBLY BRIEFLY CLEAR AND ALLOW A RIDGE/VALLEY TEMP SPLIT
TO DEVELOP IN SOUTHEASTERN VALLEYS. NEVERTHELESS...MIN T ON MON
NIGHT SHOULD ALSO BE ABOVE NORMAL.
OTHERWISE...THE BULK OF THE PERIOD SHOULD BE DRY WITH SOUTHERLY TO
SOUTHWESTERLY LOW LEVEL FLOW INCREASING LATE IN THE PERIOD IN
ADVANCE OF A DEVELOPING MUCH MORE SIGNIFICANT SYSTEM THAT WILL IMPACT
THE REGION FROM MIDWEEK ON. THE 12Z AND 18Z NAM AS WELL AS THE 12Z
ECMWF SUGGEST A STRAY SHOWER MIGHT BE POSSIBLE OVER THE SOUTHWEST ON
TUE IN THE WARM SECTOR...BUT THE OTHER GUIDANCE WAS MORE SUPPORTIVE
OF JUST A CONSIDERABLE AMOUNT OF CLOUDS FROM TIME TO TIME. MUCH OF
THE RECENT MAX T GUIDANCE SUGGESTS TUE WILL BE RATHER MILD...ABOVE
NORMAL AND IF CLOUDS WERE TO THIN FOR A WHILE 60 DEGREES WOULD BE
REACHABLE IN MANY LOCATIONS. TUE TEMPS WERE RAISED A COUPLE OF DEGREES
ON AVERAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 PM EST SUN DEC 1 2013
THE UPPER AIR PATTERN OVER THE EASTERN THIRD OF THE CONUS WILL
FEATURE A LARGE STORM SYSTEM TAKING SHAPE OVER THE NORTHERN PLAINS
TO BEGIN THE PERIOD. BOTH THE GFS AND ECMWF MODELS HAVE VERY SIMILAR
SOLUTIONS REGARDING THE STRENGTH AND EVOLUTION OF THIS SYSTEM. THIS
SYSTEM IS PROGGED TO MOVE ACROSS THE UPPER GREAT LAKES REGION
WEDNESDAY NIGHT AND THURSDAY. AS IT DOES SO...A SURFACE COLD FRONT
WILL MOVE INTO THE AREA FROM THE NORTHWEST...AND EVENTUALLY STALL
ACROSS THE OHIO AND UPPER TENNESSEE VALLEY REGIONS FROM THURSDAY
NIGHT THROUGH SUNDAY. WEAK WAVES OF LOW PRESSURE MOVING ALONG THIS
BOUNDARY...COUPLED WITH A STRONG FEED OF MOISTURE OFF THE GULF OF
MEXICO...WILL COMBINE TO BRING A PROLONGED PERIOD OF PRECIPITATION
TO EASTERN KENTUCKY. THE FIRST COUPLE OF DAYS OF THE PERIOD WILL
FEATURE PERSISTENT SOUTHERLY FLOW OFF THE GULF...WITH HIGH
TEMPERATURES IN THE LOWER 60S ON WEDNESDAY...AND IN THE MID TO UPPER
50S ON THURSDAY. THE WARM MOIST AIR OFF THE GULF WILL BRING AN
INCREASE IN CLOUD COVER AS THE FRONT APPROACHES FROM THE WEST. THE
FIRST PRECIPITATION IS EXPECTED TO MOVE INTO THE NORTHWEST PART OF
THE AREA EARLY WEDNESDAY MORNING...AS WARM MOIST AIR BEGINS TO
INTERACT WITH THE LEADING EDGE OF THE APPROACHING COLD FRONT. AS THE
FRONT CONTINUES TO MOVE SLOWLY EASTWARD...PRECIPITATION WILL
INCREASE IN COVERAGE. THE FIRST GOOD CHANCE OF RAIN SHOULD ARRIVE
WEDNESDAY NIGHT...AS THE FRONT MOVES SOUTH OF THE OHIO RIVER. THE
BEST CHANCE FOR PRECIPITATION WILL OCCUR FROM EARLY THURSDAY MORNING
THROUGH EARLY SATURDAY MORNING...AS THE FRONT STALLS OVER THE
REGION. PRECIPITATION CHANCES SHOULD REMAIN IN THE FORECAST THROUGH
SATURDAY NIGHT...AS YET ANOTHER WEAK WAVE OF LOW PRESSURE MOVES
ALONG THE SLUGGISH FRONTAL BOUNDARY.
TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP PRECIPITATION IN THE
FORM OF RAIN FROM WEDNESDAY THROUGH FRIDAY AFTERNOON. WITH THE FRONT
STALLED OVER THE AREA...AND WITH A STEADY FEED OF MOISTURE OFF THE
GULF OF MEXICO INTERACTING WITH THE FRONT...THERE WILL THE POTENTIAL
FOR LOCALLY HEAVY RAINFALL. ONCE THE FRONT MOVES THROUGH THE
AREA...AND WINDS SHIFT TO THE NORTHWEST AND EVENTUALLY NORTH...SNOW
MAY BEGIN TO MIX WITH THE RAIN...BEGINNING IN THE FAR NORTHWESTERN
PORTION OF THE FORECAST AREA. THE LATEST TIME HEIGHT CROSS SECTIONS
AND SOUNDINGS SUPPORT A MIX OF RAIN AND SNOW FRIDAY NIGHT THROUGH
THE END OF THE DAY ON SATURDAY. IF THE LATEST MODEL DATA HOLDS
TRUE...THERE COULD BE ENOUGH COLD AIR IN PLACE ACROSS THE AREA FROM
EARLY SATURDAY NIGHT THROUGH EARLY SUNDAY AFTERNOON FOR
PRECIPITATION TO CHANGE OVER TO ALL SNOW. IF THIS TURNS OUT TO BE
THE CASE...WE COULD SEE SOME LIGHT SNOW ACCUMULATIONS SATURDAY NIGHT
AND SUNDAY ACROSS EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 625 PM EST SUN DEC 1 2013
HIGH PRESSURE TO OUR SOUTHEAST AND A WEAK COLD FRONT FROM LAKE ERIE
TO SOUTHERN IL WILL RESULT IN A WEAK SOUTHERLY FLOW WHICH WILL
CONTINUE TO TRANSPORT MOISTURE NORTHEASTWARD INTO EASTERN KY. THIS
WILL KEEP WIDESPREAD LOW CLOUDINESS...BUT MAINLY VFR
CEILINGS...ACROSS THE AREA THROUGH THE NIGHT AND INTO MONDAY. AT THIS
TIME IT STILL APPEARS CEILINGS MAY LOWER TO BELOW 3K FEET FOR A
PERIOD OF TIME LATE TONIGHT AND INTO MONDAY MORNING...AND THIS HAS
BEEN REFLECTED IN THE LATEST TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...JP
LONG TERM...AR
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
636 PM EST SUN DEC 1 2013
.UPDATE...
ISSUED AT 636 PM EST SUN DEC 1 2013
LOW CLOUDS CONTINUE TO HOLD ACROSS THE AREA...AND WILL LIMIT
TEMPERATURE FALLS THIS EVENING. THE PREVIOUS FORECAST HAD THIS WELL
HANDLED. NDFD WAS UPDATED FOR LATEST HOURLY TRENDS BUT THIS RESULTED
IN ONLY MINOR CHANGES TO THE HOURLY NDFD FORECASTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 338 PM EST SUN DEC 1 2013
A BAND OF LOW CLOUDS REMAINS ACROSS THE REGION IN ADVANCE OF A WEAK
COLD FRONT THAT IS BEGINNING TO SLOW DOWN AND STALL OUT. SOME OF
THESE HAVE ERODED A BIT FROM THE SOUTH OR SOUTHEAST AND NORTHWEST
THROUGHOUT THE DAY. THIS HAS LED TO THE COLDEST TEMPERATURES ON
AVERAGE BETWEEN THE HAL ROGERS PARKWAY AND KY HIGHWAY 80 CORRIDOR AND
INTERSTATE 64 CORRIDOR. SOME OF THE DEEPER SHELTERED VALLEYS NEVER
REALLY MIXED OUT AND TEMPERATURES THERE ARE IN THE LOW TO MID 40S
ATTM. OTHERWISE TEMPS WERE NEAR 50 ACROSS MUCH OF THE SOUTHERN CWA
AND HAD NEARED 50 NORTH OF THE INTERSTATE 64 CORRIDOR.
A WEAK DISTURBANCE IS EXPECTED TO MAINLY PASS TO OUR SOUTH LATER
TONIGHT INTO MONDAY MORNING WHILE A MORE NORTHERN SHORTWAVE WILL
PASS TO THE NORTH OF EASTERN KY ON MONDAY AFTERNOON AND EVENING. THIS
WILL LEAD TO A BRIEF DEVELOPMENT OF A SOUTHEASTERN TROUGH BY MONDAY.
THIS TROUGH WILL MOVE ON OFF TO THE EAST WITH SOME WEAK RIDGING
PASSING THROUGH OVER THE SOUTHEASTERN US AND TN VALLEY FOR MON NIGHT
INTO TUE. AT THE END OF THE PERIOD...A TROUGH IS ANTICIPATED TO
EXTEND FROM CENTRAL CANADA INTO THE NORTHERN PLAINS AND THEN
SOUTHWEST INTO THE ROCKIES AND CALIFORNIA WITH MORE OR LESS ZONAL
FLOW IN THE EASTERN CONUS.
AS AT THE SFC...THE BOUNDARY TO OUR NORTHWEST SHOULD STALL NEAR THE
OH RIVER TONIGHT AND INTO MONDAY BEFORE RETURNING NORTH AS A WARM
FRONT LATER ON MONDAY INTO TUESDAY. MODELS INDICATE A GENERAL
GRADUAL INCREASE IN MOISTURE BELOW THE CURRENT CLOUD LAYER
TONIGHT...BUT MEAGER OMEGA AT BEST. UP UNTIL TODAY AT LEAST...MODELS
SEEM TO HAVE BEEN TOO AGGRESSIVE INCREASING LOW LEVEL MOISTURE.
HOWEVER...DEWPOINTS HAVE CREPT UP INTO THE MID TO UPPER 30S IN
WESTERN AND CENTRAL KY AND MIDDLE AND WESTERN TN. THIS LEADS TO
UNCERTAINTY AS TO WHETHER OR NOT THE STRATOCU DECK COULD LOWER LATER
TONIGHT INTO EARLY ON MONDAY AND WHETHER OR NOT THERE COULD BE SOME
PATCHY DRIZZLE AT THAT TIME. THE 12Z NAM AND 12Z GFS HAD SOME LIGHT
SPOTTY QPF WITH THIS LATE TONIGHT OR MONDAY. THE 18Z HRRR ALSO HAD
SOME LIGHT SPOTTY QPF LATER TONIGHT. THE 15Z SREF POPS ARE LOW AND
HAVE TRENDED DOWN SINCE 24 HOURS AGO. OPTED TO GO WITH A 10 POP FOR
PATCHY DRIZZLE IN ALL BUT THE FAR SOUTHEAST LATE TONIGHT AND INTO
MONDAY MORNING AND THEN STAYED CLOSE TO THE PREVIOUS FORECAST FOR
LATER ON MONDAY INTO MONDAY EVENING WITH A SLIGHT CHANCE IN THE FAR
NORTH. THIS LED TO BETTER ISC CONSISTENCY.
WITH LOW CLOUDS EXPECTED FOR MOST...IF NOT ALL OF THE NIGHT...MIN T
TONIGHT WILL BE CONSIDERABLY MILDER IN DEEPER SHELTERED VALLEY
LOCATIONS COMPARED TO RECENT NIGHTS. MIN T SHOULD REMAIN ABOVE
FREEZING IN ALL LOCATIONS. SOME THINNING OF THE CLOUDS IS ANTICIPATED
ON MON AFTERNOON AND TEMPS SHOULD GENERALLY REACH THE LOW TO MID 50S.
MIN T ON MON NIGHT IS A BIT MORE UNCERTAIN...AS SOME OF THE GUIDANCE
SUGGESTS THERE COULD BE WINDOW OF TIME WHERE CLOUDS COULD BE THIN
ENOUGH OR POSSIBLY BRIEFLY CLEAR AND ALLOW A RIDGE/VALLEY TEMP SPLIT
TO DEVELOP IN SOUTHEASTERN VALLEYS. NEVERTHELESS...MIN T ON MON
NIGHT SHOULD ALSO BE ABOVE NORMAL.
OTHERWISE...THE BULK OF THE PERIOD SHOULD BE DRY WITH SOUTHERLY TO
SOUTHWESTERLY LOW LEVEL FLOW INCREASING LATE IN THE PERIOD IN
ADVANCE OF A DEVELOPING MUCH MORE SIGNIFICANT SYSTEM THAT WILL IMPACT
THE REGION FROM MIDWEEK ON. THE 12Z AND 18Z NAM AS WELL AS THE 12Z
ECMWF SUGGEST A STRAY SHOWER MIGHT BE POSSIBLE OVER THE SOUTHWEST ON
TUE IN THE WARM SECTOR...BUT THE OTHER GUIDANCE WAS MORE SUPPORTIVE
OF JUST A CONSIDERABLE AMOUNT OF CLOUDS FROM TIME TO TIME. MUCH OF
THE RECENT MAX T GUIDANCE SUGGESTS TUE WILL BE RATHER MILD...ABOVE
NORMAL AND IF CLOUDS WERE TO THIN FOR A WHILE 60 DEGREES WOULD BE
REACHABLE IN MANY LOCATIONS. TUE TEMPS WERE RAISED A COUPLE OF DEGREES
ON AVERAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 PM EST SUN DEC 1 2013
THE UPPER AIR PATTERN OVER THE EASTERN THIRD OF THE CONUS WILL
FEATURE A LARGE STORM SYSTEM TAKING SHAPE OVER THE NORTHERN PLAINS
TO BEGIN THE PERIOD. BOTH THE GFS AND ECMWF MODELS HAVE VERY SIMILAR
SOLUTIONS REGARDING THE STRENGTH AND EVOLUTION OF THIS SYSTEM. THIS
SYSTEM IS PROGGED TO MOVE ACROSS THE UPPER GREAT LAKES REGION
WEDNESDAY NIGHT AND THURSDAY. AS IT DOES SO...A SURFACE COLD FRONT
WILL MOVE INTO THE AREA FROM THE NORTHWEST...AND EVENTUALLY STALL
ACROSS THE OHIO AND UPPER TENNESSEE VALLEY REGIONS FROM THURSDAY
NIGHT THROUGH SUNDAY. WEAK WAVES OF LOW PRESSURE MOVING ALONG THIS
BOUNDARY...COUPLED WITH A STRONG FEED OF MOISTURE OFF THE GULF OF
MEXICO...WILL COMBINE TO BRING A PROLONGED PERIOD OF PRECIPITATION
TO EASTERN KENTUCKY. THE FIRST COUPLE OF DAYS OF THE PERIOD WILL
FEATURE PERSISTENT SOUTHERLY FLOW OFF THE GULF...WITH HIGH
TEMPERATURES IN THE LOWER 60S ON WEDNESDAY...AND IN THE MID TO UPPER
50S ON THURSDAY. THE WARM MOIST AIR OFF THE GULF WILL BRING AN
INCREASE IN CLOUD COVER AS THE FRONT APPROACHES FROM THE WEST. THE
FIRST PRECIPITATION IS EXPECTED TO MOVE INTO THE NORTHWEST PART OF
THE AREA EARLY WEDNESDAY MORNING...AS WARM MOIST AIR BEGINS TO
INTERACT WITH THE LEADING EDGE OF THE APPROACHING COLD FRONT. AS THE
FRONT CONTINUES TO MOVE SLOWLY EASTWARD...PRECIPITATION WILL
INCREASE IN COVERAGE. THE FIRST GOOD CHANCE OF RAIN SHOULD ARRIVE
WEDNESDAY NIGHT...AS THE FRONT MOVES SOUTH OF THE OHIO RIVER. THE
BEST CHANCE FOR PRECIPITATION WILL OCCUR FROM EARLY THURSDAY MORNING
THROUGH EARLY SATURDAY MORNING...AS THE FRONT STALLS OVER THE
REGION. PRECIPITATION CHANCES SHOULD REMAIN IN THE FORECAST THROUGH
SATURDAY NIGHT...AS YET ANOTHER WEAK WAVE OF LOW PRESSURE MOVES
ALONG THE SLUGGISH FRONTAL BOUNDARY.
TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP PRECIPITATION IN THE
FORM OF RAIN FROM WEDNESDAY THROUGH FRIDAY AFTERNOON. WITH THE FRONT
STALLED OVER THE AREA...AND WITH A STEADY FEED OF MOISTURE OFF THE
GULF OF MEXICO INTERACTING WITH THE FRONT...THERE WILL THE POTENTIAL
FOR LOCALLY HEAVY RAINFALL. ONCE THE FRONT MOVES THROUGH THE
AREA...AND WINDS SHIFT TO THE NORTHWEST AND EVENTUALLY NORTH...SNOW
MAY BEGIN TO MIX WITH THE RAIN...BEGINNING IN THE FAR NORTHWESTERN
PORTION OF THE FORECAST AREA. THE LATEST TIME HEIGHT CROSS SECTIONS
AND SOUNDINGS SUPPORT A MIX OF RAIN AND SNOW FRIDAY NIGHT THROUGH
THE END OF THE DAY ON SATURDAY. IF THE LATEST MODEL DATA HOLDS
TRUE...THERE COULD BE ENOUGH COLD AIR IN PLACE ACROSS THE AREA FROM
EARLY SATURDAY NIGHT THROUGH EARLY SUNDAY AFTERNOON FOR
PRECIPITATION TO CHANGE OVER TO ALL SNOW. IF THIS TURNS OUT TO BE
THE CASE...WE COULD SEE SOME LIGHT SNOW ACCUMULATIONS SATURDAY NIGHT
AND SUNDAY ACROSS EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 625 PM EST SUN DEC 1 2013
HIGH PRESSURE TO OUR SOUTHEAST AND A WEAK COLD FRONT FROM LAKE ERIE
TO SOUTHERN IL WILL RESULT IN A WEAK SOUTHERLY FLOW WHICH WILL
CONTINUE TO TRANSPORT MOISTURE NORTHEASTWARD INTO EASTERN KY. THIS
WILL KEEP WIDESPREAD LOW CLOUDINESS...BUT MAINLY VFR
CEILINGS...ACROSS THE AREA THROUGH THE NIGHT AND INTO MONDAY. AT THIS
TIME IT STILL APPEARS CEILINGS MAY LOWER TO BELOW 3K FEET FOR A
PERIOD OF TIME LATE TONIGHT AND INTO MONDAY MORNING...AND THIS HAS
BEEN REFLECTED IN THE LATEST TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...JP
LONG TERM...AR
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
629 PM EST SUN DEC 1 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 338 PM EST SUN DEC 1 2013
A BAND OF LOW CLOUDS REMAINS ACROSS THE REGION IN ADVANCE OF A WEAK
COLD FRONT THAT IS BEGINNING TO SLOW DOWN AND STALL OUT. SOME OF
THESE HAVE ERODED A BIT FROM THE SOUTH OR SOUTHEAST AND NORTHWEST
THROUGHOUT THE DAY. THIS HAS LED TO THE COLDEST TEMPERATURES ON
AVERAGE BETWEEN THE HAL ROGERS PARKWAY AND KY HIGHWAY 80 CORRIDOR AND
INTERSTATE 64 CORRIDOR. SOME OF THE DEEPER SHELTERED VALLEYS NEVER
REALLY MIXED OUT AND TEMPERATURES THERE ARE IN THE LOW TO MID 40S
ATTM. OTHERWISE TEMPS WERE NEAR 50 ACROSS MUCH OF THE SOUTHERN CWA
AND HAD NEARED 50 NORTH OF THE INTERSTATE 64 CORRIDOR.
A WEAK DISTURBANCE IS EXPECTED TO MAINLY PASS TO OUR SOUTH LATER
TONIGHT INTO MONDAY MORNING WHILE A MORE NORTHERN SHORTWAVE WILL
PASS TO THE NORTH OF EASTERN KY ON MONDAY AFTERNOON AND EVENING. THIS
WILL LEAD TO A BRIEF DEVELOPMENT OF A SOUTHEASTERN TROUGH BY MONDAY.
THIS TROUGH WILL MOVE ON OFF TO THE EAST WITH SOME WEAK RIDGING
PASSING THROUGH OVER THE SOUTHEASTERN US AND TN VALLEY FOR MON NIGHT
INTO TUE. AT THE END OF THE PERIOD...A TROUGH IS ANTICIPATED TO
EXTEND FROM CENTRAL CANADA INTO THE NORTHERN PLAINS AND THEN
SOUTHWEST INTO THE ROCKIES AND CALIFORNIA WITH MORE OR LESS ZONAL
FLOW IN THE EASTERN CONUS.
AS AT THE SFC...THE BOUNDARY TO OUR NORTHWEST SHOULD STALL NEAR THE
OH RIVER TONIGHT AND INTO MONDAY BEFORE RETURNING NORTH AS A WARM
FRONT LATER ON MONDAY INTO TUESDAY. MODELS INDICATE A GENERAL
GRADUAL INCREASE IN MOISTURE BELOW THE CURRENT CLOUD LAYER
TONIGHT...BUT MEAGER OMEGA AT BEST. UP UNTIL TODAY AT LEAST...MODELS
SEEM TO HAVE BEEN TOO AGGRESSIVE INCREASING LOW LEVEL MOISTURE.
HOWEVER...DEWPOINTS HAVE CREPT UP INTO THE MID TO UPPER 30S IN
WESTERN AND CENTRAL KY AND MIDDLE AND WESTERN TN. THIS LEADS TO
UNCERTAINTY AS TO WHETHER OR NOT THE STRATOCU DECK COULD LOWER LATER
TONIGHT INTO EARLY ON MONDAY AND WHETHER OR NOT THERE COULD BE SOME
PATCHY DRIZZLE AT THAT TIME. THE 12Z NAM AND 12Z GFS HAD SOME LIGHT
SPOTTY QPF WITH THIS LATE TONIGHT OR MONDAY. THE 18Z HRRR ALSO HAD
SOME LIGHT SPOTTY QPF LATER TONIGHT. THE 15Z SREF POPS ARE LOW AND
HAVE TRENDED DOWN SINCE 24 HOURS AGO. OPTED TO GO WITH A 10 POP FOR
PATCHY DRIZZLE IN ALL BUT THE FAR SOUTHEAST LATE TONIGHT AND INTO
MONDAY MORNING AND THEN STAYED CLOSE TO THE PREVIOUS FORECAST FOR
LATER ON MONDAY INTO MONDAY EVENING WITH A SLIGHT CHANCE IN THE FAR
NORTH. THIS LED TO BETTER ISC CONSISTENCY.
WITH LOW CLOUDS EXPECTED FOR MOST...IF NOT ALL OF THE NIGHT...MIN T
TONIGHT WILL BE CONSIDERABLY MILDER IN DEEPER SHELTERED VALLEY
LOCATIONS COMPARED TO RECENT NIGHTS. MIN T SHOULD REMAIN ABOVE
FREEZING IN ALL LOCATIONS. SOME THINNING OF THE CLOUDS IS ANTICIPATED
ON MON AFTERNOON AND TEMPS SHOULD GENERALLY REACH THE LOW TO MID 50S.
MIN T ON MON NIGHT IS A BIT MORE UNCERTAIN...AS SOME OF THE GUIDANCE
SUGGESTS THERE COULD BE WINDOW OF TIME WHERE CLOUDS COULD BE THIN
ENOUGH OR POSSIBLY BRIEFLY CLEAR AND ALLOW A RIDGE/VALLEY TEMP SPLIT
TO DEVELOP IN SOUTHEASTERN VALLEYS. NEVERTHELESS...MIN T ON MON
NIGHT SHOULD ALSO BE ABOVE NORMAL.
OTHERWISE...THE BULK OF THE PERIOD SHOULD BE DRY WITH SOUTHERLY TO
SOUTHWESTERLY LOW LEVEL FLOW INCREASING LATE IN THE PERIOD IN
ADVANCE OF A DEVELOPING MUCH MORE SIGNIFICANT SYSTEM THAT WILL IMPACT
THE REGION FROM MIDWEEK ON. THE 12Z AND 18Z NAM AS WELL AS THE 12Z
ECMWF SUGGEST A STRAY SHOWER MIGHT BE POSSIBLE OVER THE SOUTHWEST ON
TUE IN THE WARM SECTOR...BUT THE OTHER GUIDANCE WAS MORE SUPPORTIVE
OF JUST A CONSIDERABLE AMOUNT OF CLOUDS FROM TIME TO TIME. MUCH OF
THE RECENT MAX T GUIDANCE SUGGESTS TUE WILL BE RATHER MILD...ABOVE
NORMAL AND IF CLOUDS WERE TO THIN FOR A WHILE 60 DEGREES WOULD BE
REACHABLE IN MANY LOCATIONS. TUE TEMPS WERE RAISED A COUPLE OF DEGREES
ON AVERAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 PM EST SUN DEC 1 2013
THE UPPER AIR PATTERN OVER THE EASTERN THIRD OF THE CONUS WILL
FEATURE A LARGE STORM SYSTEM TAKING SHAPE OVER THE NORTHERN PLAINS
TO BEGIN THE PERIOD. BOTH THE GFS AND ECMWF MODELS HAVE VERY SIMILAR
SOLUTIONS REGARDING THE STRENGTH AND EVOLUTION OF THIS SYSTEM. THIS
SYSTEM IS PROGGED TO MOVE ACROSS THE UPPER GREAT LAKES REGION
WEDNESDAY NIGHT AND THURSDAY. AS IT DOES SO...A SURFACE COLD FRONT
WILL MOVE INTO THE AREA FROM THE NORTHWEST...AND EVENTUALLY STALL
ACROSS THE OHIO AND UPPER TENNESSEE VALLEY REGIONS FROM THURSDAY
NIGHT THROUGH SUNDAY. WEAK WAVES OF LOW PRESSURE MOVING ALONG THIS
BOUNDARY...COUPLED WITH A STRONG FEED OF MOISTURE OFF THE GULF OF
MEXICO...WILL COMBINE TO BRING A PROLONGED PERIOD OF PRECIPITATION
TO EASTERN KENTUCKY. THE FIRST COUPLE OF DAYS OF THE PERIOD WILL
FEATURE PERSISTENT SOUTHERLY FLOW OFF THE GULF...WITH HIGH
TEMPERATURES IN THE LOWER 60S ON WEDNESDAY...AND IN THE MID TO UPPER
50S ON THURSDAY. THE WARM MOIST AIR OFF THE GULF WILL BRING AN
INCREASE IN CLOUD COVER AS THE FRONT APPROACHES FROM THE WEST. THE
FIRST PRECIPITATION IS EXPECTED TO MOVE INTO THE NORTHWEST PART OF
THE AREA EARLY WEDNESDAY MORNING...AS WARM MOIST AIR BEGINS TO
INTERACT WITH THE LEADING EDGE OF THE APPROACHING COLD FRONT. AS THE
FRONT CONTINUES TO MOVE SLOWLY EASTWARD...PRECIPITATION WILL
INCREASE IN COVERAGE. THE FIRST GOOD CHANCE OF RAIN SHOULD ARRIVE
WEDNESDAY NIGHT...AS THE FRONT MOVES SOUTH OF THE OHIO RIVER. THE
BEST CHANCE FOR PRECIPITATION WILL OCCUR FROM EARLY THURSDAY MORNING
THROUGH EARLY SATURDAY MORNING...AS THE FRONT STALLS OVER THE
REGION. PRECIPITATION CHANCES SHOULD REMAIN IN THE FORECAST THROUGH
SATURDAY NIGHT...AS YET ANOTHER WEAK WAVE OF LOW PRESSURE MOVES
ALONG THE SLUGGISH FRONTAL BOUNDARY.
TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP PRECIPITATION IN THE
FORM OF RAIN FROM WEDNESDAY THROUGH FRIDAY AFTERNOON. WITH THE FRONT
STALLED OVER THE AREA...AND WITH A STEADY FEED OF MOISTURE OFF THE
GULF OF MEXICO INTERACTING WITH THE FRONT...THERE WILL THE POTENTIAL
FOR LOCALLY HEAVY RAINFALL. ONCE THE FRONT MOVES THROUGH THE
AREA...AND WINDS SHIFT TO THE NORTHWEST AND EVENTUALLY NORTH...SNOW
MAY BEGIN TO MIX WITH THE RAIN...BEGINNING IN THE FAR NORTHWESTERN
PORTION OF THE FORECAST AREA. THE LATEST TIME HEIGHT CROSS SECTIONS
AND SOUNDINGS SUPPORT A MIX OF RAIN AND SNOW FRIDAY NIGHT THROUGH
THE END OF THE DAY ON SATURDAY. IF THE LATEST MODEL DATA HOLDS
TRUE...THERE COULD BE ENOUGH COLD AIR IN PLACE ACROSS THE AREA FROM
EARLY SATURDAY NIGHT THROUGH EARLY SUNDAY AFTERNOON FOR
PRECIPITATION TO CHANGE OVER TO ALL SNOW. IF THIS TURNS OUT TO BE
THE CASE...WE COULD SEE SOME LIGHT SNOW ACCUMULATIONS SATURDAY NIGHT
AND SUNDAY ACROSS EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 625 PM EST SUN DEC 1 2013
HIGH PRESSURE TO OUR SOUTHEAST AND A WEAK COLD FRONT FROM LAKE ERIE
TO SOUTHERN IL WILL RESULT IN A WEAK SOUTHERLY FLOW WHICH WILL
CONTINUE TO TRANSPORT MOISTURE NORTHEASTWARD INTO EASTERN KY. THIS
WILL KEEP WIDESPREAD LOW CLOUDINESS...BUT MAINLY VFR
CEILINGS...ACROSS THE AREA THROUGH THE NIGHT AND INTO MONDAY. AT THIS
TIME IT STILL APPEARS CEILINGS MAY LOWER TO BELOW 3K FEET FOR A
PERIOD OF TIME LATE TONIGHT AND INTO MONDAY MORNING...AND THIS HAS
BEEN REFLECTED IN THE LATEST TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...AR
AVIATION...SBH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1003 PM CST SUN DEC 1 2013
.UPDATE...
AFTER FURTHER ANALYSIS...DECIDED TO INCREASE LOWS 3-4 DEGREES ACROSS
THE REGION. INCREASING MOISTURE AND SOME WINDS STAYING UP OVERNIGHT
WILL KEEP TEMPERATURES WARMER ACROSS THE REGION. REST OF THE
PREVIOUS FORECAST IS ON TRACK AND NO OTHER CHANGES WERE MADE AT THIS
TIME. /DC/
&&
.PREV DISCUSSION... /ISSUED 856 PM CST SUN DEC 1 2013/
UPDATE...
S/WV OVER THE CENTRAL PLAINS IS AIDING IN WEAK ISENTROPIC LIFT AND
INCREASING LOW/MID LEVEL MOISTURE IN THE REGION THIS EVENING. 00Z
REGIONAL SOUNDINGS INDICATE LOW/MID LEVEL MOISTURE BEGINNING TO MOVE
IN FROM THE W/NW. THE UPPER S/WV AND WEAK LIFT IN CONJUNCTION WITH
THE INCREASING LOW/MID LEVEL MOISTURE IS AIDING IN SOME SHOWERS
DEVELOPING MAINLY IN THE HWY 82 CORRIDOR. POPS LOOK GOOD FOR THIS
EVENING BUT SLOWED DOWN THE SE PROGRESSION WITH CHANCES REACHING I-20
CORRIDOR AFTER 6Z AND E MS AFTER 9Z. LOCAL WRF INDICATES SOME SHOWERS
DEVELOPING NEAR THE I-20 CORRIDOR AND FARTHER S/SW AROUND 9-11Z AS
THE S/WV MOVES THROUGH THE REGION. ALSO MOVED THUNDER IN WX GRIDS
FARTHER NORTH AS RUC INDICATES MOST NEGATIVE SHOWALTERS WILL STAY
CONFINED N OF I-20. LOWS LOOK GOOD OVERNIGHT. ONLY ADJUSTED HOURLY
TEMPS/DEWPOINTS ACCORDING TO CURRENT TRENDS. REST OF THE FORECAST IS
ON TRACK. /DC/
&&
.AVIATION...
CLOUDY CONDITIONS EXIST ACROSS THE CWA BUT CEILINGS HOLD
IN VFR CATEGORY AT ALL SITES. LOOK FOR CEILINGS TO TREND TO MVFR
ALONG THE HWY 82 CORRIDOR A BIT LATER...SAY STARTING BETWEEN 04-06Z.
ALSO DURING THIS TIME SOME LIGHT SHRA ACTIVITY WILL BE DEVELOPING.
THERE IS AN OUTSIDE CHANCE FOR A FEW ISO TSRA...BUT WILL HOLD OFF ON
INCLUDING THAT IN THE TAF AT THIS TIME (IT WOULD BE BRIEF IF IT
OCCURRED). SITES ALONG I-20 WILL SEE MVFR CEILINGS LATER IN THE
NIGHT AND MON MORN. LOOK FOR ALL RESTRICTIONS TO IMPROVE BY
18-20Z...BUT SOME VFR CEILINGS COULD LINGER. /CME/
PREV DISCUSSION... /ISSUED 415 PM CST SUN DEC 1 2013/
DISCUSSION...THE WARMING AND MOISTENING TREND LOOKS TO CONTINUE
WELL INTO THE WEEK...ALTHOUGH UNFORTUNATELY CLEAR SKIES DO NOT LOOK
TO ACCOMPANY THE FAVORABLE TREND IN TEMPERATURES.
THE FIRST BOUT OF CONCENTRATED CLOUDS LOOKS TO COME TONIGHT THROUGH
AT LEAST THE FIRST HALF OF TOMORROW AS A FLAT SHORT WAVE IN SUBTLE
NORTHWEST FLOW PASSES ACROSS THE LOWER MS VALLEY. A TRUE SURFACE
FRONTAL WAVE WILL REMAIN ANCHORED OUT TO THE WEST BUT THERE SHOULD
BE ENOUGH OF A COMBO OF ISENTROPIC LIFT...WARM AIR ADVECTION AND PVA
TO GET SOME ISOLATED TO SCATTERED SHOWERS GOING AS THE NIGHT WEARS
ON. ACTIVITY SHOULD BE MOST CONCENTRATED NORTH OF I-20 WEAR VERY
CHILLY TEMPS ALOFT COULD ALLOW A CELL OR TWO TO GENERATE A RUMBLE OR
TWO OF THUNDER. THE EXITING OF AFOREMENTIONED FLAT WAVE TO THE EAST
TOMORROW MORNING SHOULD BRING SIGNIFICANT PRECIPITATION TO AN
END...BUT IT IS NOT IMPOSSIBLE A FEW LIGHT SHOWERS COULD LINGER IN
SOUTHEAST ZONES INTO THE AFTERNOON OR EVEN EARLY EVENING.
A GENERAL CLEARING WILL TRY TO PUSH IN FROM THE NORTHWEST LATE
TOMORROW INTO TOMORROW NIGHT ALTHOUGH THE LOWER LEVELS WILL REMAIN
MOIST AND FOG OR LOW CLOUDS WILL TEND TO FORM BY EARLY TUESDAY
MORNING. SOME OF THE FOG COULD BE DENSE IF LOW CLOUDS CAN KEEP FROM
FORMING...AND THIS IS MORE LIKELY NORTHWEST OF THE NATCHEZ TRACE.
NOTHING MENTIONED IN THE HWO ABOUT THIS FOR NOW...BUT IT WILL NEED
TO BE CONSIDERED IN COMING FORECAST IF IT LOOKS LIKE FOG WILL
PREDOMINATE OVER THE STRATUS MODE.
WARMTH AND MOISTURE ADVECTION LOOK TO CONTINUE TUESDAY AND WEDNESDAY
WITH TEMPERATURES TEMPORARILY GETTING INTO THE WELL ABOVE NORMAL
RANGE...ALTHOUGH THERE WILL PROBABLY BE A FAIR AMOUNT OF CLOUDS AND
AT LEAST SOME ISOLATED SHOWERS ABOUT. BUT CONSIDERING THE TOTAL 7
DAY FORECAST...THESE WILL DEFINITELY BE DECENT DAYS COMPARED TO
THOSE COMING LATER IN THE WEEK.
BY WEDNESDAY NIGHT AN APPROACHING COLD AND VERY SHALLOW AIRMASS WILL
DRIVE A COLD FRONT INTO THE REGION FROM THE NORTHWEST WITH THIS
BOUNDARY LIKELY CLEARING THROUGH THE REGION SOMETIME THURSDAY. THE
BOUNDARY WILL OF COURSE KICK OFF BETTER CHANCES OF RAIN AND PERHAPS
A FEW THUNDERSTORMS CONSIDERING LEVEL OF WARMTH AND MOISTURE THAT
WILL BE IN PLAY. HOWEVER...AT THIS POINT IT DOES NOT APPEAR SEVERE
WEATHER IS MUCH OF A WORRY GIVEN THE SHALLOW AND UNDERCUTTING NATURE
OF THE AIR MASS.
THE BIG WORRY FROM THESE DEVELOPMENTS IS THAT THE FRONTAL BOUNDARY A
FEW THOUSAND FEET ABOVE THE GROUND WILL LIKELY HANG UP NORTHWEST OF
AND PARALLEL TO THE NATCHEZ TRACE WHILE A LARGE UPPER LEVEL TROUGH
ANCHOR CONTINUES TO DIG OUT IN THE WESTERN HALF OF THE CONUS. THIS
KIND OF SET UP MAY KEEP CLOUDS AND PRECIPITATION GOING FOR DAYS (AS
IN...THROUGH THE WEEKEND) FOR OUR REGION. THIS BRINGS WINTRY
PRECIPITATION PROSPECTS INTO PLAY FOR AT LEAST ARKLAMISS DELTA
ZONES...POSSIBLY AS EARLY AS THURSDAY MORNING. NATURE OF THE SETUP
WITH WARM AIR OVERRUNNING VERY COLD AIR AT THE SURFACE MAKES
FREEZING RAIN AND ICE SEEM MOST LIKELY IMPACT. THE OFFICIAL FORECAST
ONLY HAS WINTRY PRECIP TYPES MENTIONED FOR A FEW PERIODS FROM
THURSDAY NIGHT INTO THE WEEKEND IN THAT NECK OF THE WOODS...BUT
THERE IS A REAL POSSIBILITY IN A WORSE CASE SCENARIO THAT ICING
COULD BUILD IN THURSDAY IN PORTIONS OF THE DELTA AND NOT LET UP
THROUGH THE WEEKEND. THE POTENTIAL FOR ANY WINTRY WEATHER DECREASES
AS YOU GO SOUTHEAST FROM THE DELTA AND SHOULD ONLY BE FOR SHORTER
TIME PERIODS IN A WORST SCENARIO. CONSIDERING THIS IS STILL QUITE A
FEW DAYS AWAY IN THE FORECAST THERE IS DEFINITELY UNCERTAINTY TO
CONSIDER. BUT EVEN TAKING THAT UNCERTAINTY INTO ACCOUNT IT SEEMS
PRUDENT TO MENTION THE ICING CONCERN FOR ARKLAMISS DELTA LOCATIONS
IN THE HWO AT THIS JUNCTURE.
NEEDLESS TO SAY...TEMPERATURES WILL BE HEADED BACK WELL BELOW NORMAL
LATER THIS WEEK AND WE WILL BE MONITORING THE LONG RANGE FORECAST
VERY CLOSELY IN THE COMING DAYS. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 52 66 52 73 / 34 20 8 8
MERIDIAN 48 65 51 72 / 36 26 12 10
VICKSBURG 53 67 48 74 / 30 15 4 7
HATTIESBURG 50 70 56 77 / 14 16 17 14
NATCHEZ 54 69 53 74 / 25 13 6 11
GREENVILLE 53 63 49 71 / 57 17 3 6
GREENWOOD 51 63 49 69 / 62 20 3 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/CME/BB
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
856 PM CST SUN DEC 1 2013
.UPDATE...
S/WV OVER THE CENTRAL PLAINS IS AIDING IN WEAK ISENTROPIC LIFT AND
INCREASING LOW/MID LEVEL MOISTURE IN THE REGION THIS EVENING. 00Z
REGIONAL SOUNDINGS INDICATE LOW/MID LEVEL MOISTURE BEGINNING TO MOVE
IN FROM THE W/NW. THE UPPER S/WV AND WEAK LIFT IN CONJUNCTION WITH
THE INCREASING LOW/MID LEVEL MOISTURE IS AIDING IN SOME SHOWERS
DEVELOPING MAINLY IN THE HWY 82 CORRIDOR. POPS LOOK GOOD FOR THIS
EVENING BUT SLOWED DOWN THE SE PROGRESSION WITH CHANCES REACHING I-20
CORRIDOR AFTER 6Z AND E MS AFTER 9Z. LOCAL WRF INDICATES SOME SHOWERS
DEVELOPING NEAR THE I-20 CORRIDOR AND FARTHER S/SW AROUND 9-11Z AS
THE S/WV MOVES THROUGH THE REGION. ALSO MOVED THUNDER IN WX GRIDS
FARTHER NORTH AS RUC INDICATES MOST NEGATIVE SHOWALTERS WILL STAY
CONFINED N OF I-20. LOWS LOOK GOOD OVERNIGHT. ONLY ADJUSTED HOURLY
TEMPS/DEWPOINTS ACCORDING TO CURRENT TRENDS. REST OF THE FORECAST IS
ON TRACK. /DC/
&&
.AVIATION...CLOUDY CONDITIONS EXIST ACROSS THE CWA BUT CEILINGS HOLD
IN VFR CATEGORY AT ALL SITES. LOOK FOR CEILINGS TO TREND TO MVFR
ALONG THE HWY 82 CORRIDOR A BIT LATER...SAY STARTING BETWEEN 04-06Z.
ALSO DURING THIS TIME SOME LIGHT SHRA ACTIVITY WILL BE DEVELOPING.
THERE IS AN OUTSIDE CHANCE FOR A FEW ISO TSRA...BUT WILL HOLD OFF ON
INCLUDING THAT IN THE TAF AT THIS TIME (IT WOULD BE BRIEF IF IT
OCCURRED). SITES ALONG I-20 WILL SEE MVFR CEILINGS LATER IN THE
NIGHT AND MON MORN. LOOK FOR ALL RESTRICTIONS TO IMPROVE BY
18-20Z...BUT SOME VFR CEILINGS COULD LINGER. /CME/
&&
.PREV DISCUSSION... /ISSUED 415 PM CST SUN DEC 1 2013/
DISCUSSION...THE WARMING AND MOISTENING TREND LOOKS TO CONTINUE
WELL INTO THE WEEK...ALTHOUGH UNFORTUNATELY CLEAR SKIES DO NOT LOOK
TO ACCOMPANY THE FAVORABLE TREND IN TEMPERATURES.
THE FIRST BOUT OF CONCENTRATED CLOUDS LOOKS TO COME TONIGHT THROUGH
AT LEAST THE FIRST HALF OF TOMORROW AS A FLAT SHORT WAVE IN SUBTLE
NORTHWEST FLOW PASSES ACROSS THE LOWER MS VALLEY. A TRUE SURFACE
FRONTAL WAVE WILL REMAIN ANCHORED OUT TO THE WEST BUT THERE SHOULD
BE ENOUGH OF A COMBO OF ISENTROPIC LIFT...WARM AIR ADVECTION AND PVA
TO GET SOME ISOLATED TO SCATTERED SHOWERS GOING AS THE NIGHT WEARS
ON. ACTIVITY SHOULD BE MOST CONCENTRATED NORTH OF I-20 WEAR VERY
CHILLY TEMPS ALOFT COULD ALLOW A CELL OR TWO TO GENERATE A RUMBLE OR
TWO OF THUNDER. THE EXITING OF AFOREMENTIONED FLAT WAVE TO THE EAST
TOMORROW MORNING SHOULD BRING SIGNIFICANT PRECIPITATION TO AN
END...BUT IT IS NOT IMPOSSIBLE A FEW LIGHT SHOWERS COULD LINGER IN
SOUTHEAST ZONES INTO THE AFTERNOON OR EVEN EARLY EVENING.
A GENERAL CLEARING WILL TRY TO PUSH IN FROM THE NORTHWEST LATE
TOMORROW INTO TOMORROW NIGHT ALTHOUGH THE LOWER LEVELS WILL REMAIN
MOIST AND FOG OR LOW CLOUDS WILL TEND TO FORM BY EARLY TUESDAY
MORNING. SOME OF THE FOG COULD BE DENSE IF LOW CLOUDS CAN KEEP FROM
FORMING...AND THIS IS MORE LIKELY NORTHWEST OF THE NATCHEZ TRACE.
NOTHING MENTIONED IN THE HWO ABOUT THIS FOR NOW...BUT IT WILL NEED
TO BE CONSIDERED IN COMING FORECAST IF IT LOOKS LIKE FOG WILL
PREDOMINATE OVER THE STRATUS MODE.
WARMTH AND MOISTURE ADVECTION LOOK TO CONTINUE TUESDAY AND WEDNESDAY
WITH TEMPERATURES TEMPORARILY GETTING INTO THE WELL ABOVE NORMAL
RANGE...ALTHOUGH THERE WILL PROBABLY BE A FAIR AMOUNT OF CLOUDS AND
AT LEAST SOME ISOLATED SHOWERS ABOUT. BUT CONSIDERING THE TOTAL 7
DAY FORECAST...THESE WILL DEFINITELY BE DECENT DAYS COMPARED TO
THOSE COMING LATER IN THE WEEK.
BY WEDNESDAY NIGHT AN APPROACHING COLD AND VERY SHALLOW AIRMASS WILL
DRIVE A COLD FRONT INTO THE REGION FROM THE NORTHWEST WITH THIS
BOUNDARY LIKELY CLEARING THROUGH THE REGION SOMETIME THURSDAY. THE
BOUNDARY WILL OF COURSE KICK OFF BETTER CHANCES OF RAIN AND PERHAPS
A FEW THUNDERSTORMS CONSIDERING LEVEL OF WARMTH AND MOISTURE THAT
WILL BE IN PLAY. HOWEVER...AT THIS POINT IT DOES NOT APPEAR SEVERE
WEATHER IS MUCH OF A WORRY GIVEN THE SHALLOW AND UNDERCUTTING NATURE
OF THE AIR MASS.
THE BIG WORRY FROM THESE DEVELOPMENTS IS THAT THE FRONTAL BOUNDARY A
FEW THOUSAND FEET ABOVE THE GROUND WILL LIKELY HANG UP NORTHWEST OF
AND PARALLEL TO THE NATCHEZ TRACE WHILE A LARGE UPPER LEVEL TROUGH
ANCHOR CONTINUES TO DIG OUT IN THE WESTERN HALF OF THE CONUS. THIS
KIND OF SET UP MAY KEEP CLOUDS AND PRECIPITATION GOING FOR DAYS (AS
IN...THROUGH THE WEEKEND) FOR OUR REGION. THIS BRINGS WINTRY
PRECIPITATION PROSPECTS INTO PLAY FOR AT LEAST ARKLAMISS DELTA
ZONES...POSSIBLY AS EARLY AS THURSDAY MORNING. NATURE OF THE SETUP
WITH WARM AIR OVERRUNNING VERY COLD AIR AT THE SURFACE MAKES
FREEZING RAIN AND ICE SEEM MOST LIKELY IMPACT. THE OFFICIAL FORECAST
ONLY HAS WINTRY PRECIP TYPES MENTIONED FOR A FEW PERIODS FROM
THURSDAY NIGHT INTO THE WEEKEND IN THAT NECK OF THE WOODS...BUT
THERE IS A REAL POSSIBILITY IN A WORSE CASE SCENARIO THAT ICING
COULD BUILD IN THURSDAY IN PORTIONS OF THE DELTA AND NOT LET UP
THROUGH THE WEEKEND. THE POTENTIAL FOR ANY WINTRY WEATHER DECREASES
AS YOU GO SOUTHEAST FROM THE DELTA AND SHOULD ONLY BE FOR SHORTER
TIME PERIODS IN A WORST SCENARIO. CONSIDERING THIS IS STILL QUITE A
FEW DAYS AWAY IN THE FORECAST THERE IS DEFINITELY UNCERTAINTY TO
CONSIDER. BUT EVEN TAKING THAT UNCERTAINTY INTO ACCOUNT IT SEEMS
PRUDENT TO MENTION THE ICING CONCERN FOR ARKLAMISS DELTA LOCATIONS
IN THE HWO AT THIS JUNCTURE.
NEEDLESS TO SAY...TEMPERATURES WILL BE HEADED BACK WELL BELOW NORMAL
LATER THIS WEEK AND WE WILL BE MONITORING THE LONG RANGE FORECAST
VERY CLOSELY IN THE COMING DAYS. /BB/
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE
REMAINDER OF THE AFTERNOON. EVENTUALLY MVFR CONDITIONS...ESPECIALLY
ALONG THE HIGHWAY 82 CORRIDOR (KGLH...KGWO...AND KGTR)...WILL
PREVAIL AS CEILINGS LOWER TO BETWEEN 2000-3000 FEET LATE THIS
EVENING AS MOISTURE CONTINUES TO INCREASE ACROSS THE REGION. LIGHT
SHOWERS WILL MOVE IN LATER TONIGHT...PARTICULARLY NORTH OF
INTERSTATE 20...AND LINGER INTO MONDAY MORNING OVER MAINLY NORTHEAST
AND EAST CENTRAL MISSISSIPPI (KGTR & KMEI). WINDS WILL GENERALLY BE
LIGHT...3-6 KNOTS...FROM THE SOUTH THROUGH THE FORECAST PERIOD. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 48 66 52 73 / 34 20 8 8
MERIDIAN 46 65 51 72 / 36 26 12 10
VICKSBURG 48 67 48 74 / 30 15 4 7
HATTIESBURG 47 70 56 77 / 14 16 17 14
NATCHEZ 50 69 53 74 / 25 13 6 11
GREENVILLE 50 63 49 71 / 57 17 3 6
GREENWOOD 48 63 49 69 / 62 20 3 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/CME/BB/19
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
451 PM MST SUN DEC 1 2013
.AVIATION...
00Z TAF CYCLE
AREAS OF IFR AND MORE LOCALLY LIFR CATEGORY STRATUS CIGS WILL
LIKELY CONTINUE TO BE AN AVIATION HAZARD ACROSS A GOOD PORTION OF
NW NM THROUGH THE NEXT 18 HRS...THAT IS THROUGH 18Z MON. THE
VISIBILITY IN FOG WILL LOWER AGAIN AFTER 06Z TONIGHT TO IFR AND
PERHAPS LIFR LEVELS. ELSEWHERE ONLY HIGH CIRRUS CLOUDS AND LIGHT
TO MODERATE BREEZES ARE EXPECTED WITH VFR CONDITIONS. 40
&&
.PREV DISCUSSION...325 PM MST SUN DEC 1 2013...
MAIN FORECAST CHALLENGE IN THE SHORT-TERM CONTINUES TO BE NAILING
DOWN WHEN THE PERSISTENT LOW CLOUD DECK OVER NW AND WEST CENTRAL NM
WILL SCOUR OUT OF THE AREA. THE VAST MAJORITY OF MODEL GUIDANCE DID
NOT SHOW THESE CLOUDS CONTINUING TO PLAGUE THE AREA TODAY BUT ALAS
THEY ARE STILL HOLDING STRONG. THE RUC13 WAS THE BEST TO HOLD ONTO
SATURATION IN THE NEAR SURFACE LAYER AND INDICATIONS ARE THAT IT
WILL CONTINUE TONIGHT AND EARLY MONDAY. WINDS ALOFT AND EVEN AT THE
SURFACE ARE INCREASING HOWEVER IT IS POSSIBLE THE THICK/PERSISTENT
LOW CLOUD DECK IS FEEDING BACK TO STRENGTHEN LOW LEVEL INVERSIONS
AND KEEP A VERY SHALLOW BOUNDARY LAYER DECOUPLED. OTHER INTERESTING
ITEM WILL BE WHETHER LOW CLOUDS CAN SEEP OVER THE WEST MESA AND END
UP IN THE MIDDLE RIO GRANDE VALLEY TONIGHT AS INCREASING NW FLOW
ADVECTS THE LAYER SE. BEST SHOT WILL BE WEST SIDE SO HAVE INCREASED
TO MOSTLY CLOUDY THERE OVERNIGHT.
CONSIDERABLE DIFFERENCES REMAIN WITH MODEL GUIDANCE ON THE DETAILS
OF THE NEXT SIGNIFICANT STORM SYSTEM BEYOND WEDNESDAY. FIRST WE
HAVE TO DEAL WITH SOME WIND. NW FLOW OVER THE REGION TODAY WILL
BACK TO WEST AND INCREASE TUESDAY. 700-500MB LAYER WINDS BTWN 50
AND 60KTS WILL COMBINE WITH A SURFACE LOW OVER THE PLAINS TO CREATE
STRONG WEST WINDS ALONG AND EAST OF THE CENTRAL MT CHAIN. IT IS
STILL A LITTLE EARLY BUT BETS ARE GOOD ON A HIGH WIND WATCH FROM
THE FOLLOWING SHIFT FOR TUESDAY. HEIGHT FALLS AND COLD ADVECTION
WILL BEGIN TUESDAY NIGHT ACROSS THE WEST AS THE JET AXIS DEPARTS
TO THE EAST. MEANWHILE...THE PLAINS PORTION OF AN ARCTIC AIRMASS
WILL BE SHIFTING SOUTH TOWARD THE NE PLAINS.
MODELS THEN STRUGGLE CONSIDERABLY DEALING WITH THE APPROACH OF A
SHEARING UPPER TROUGH AXIS OVER THE WESTERN CONUS WEDNESDAY AND
THURSDAY AND THE DEGREE OF MOISTURE ASSOCIATED WITH IT. A REALLY
GOOD CERTAINTY IS THAT IT IS GOING TO GET VERY COLD. AT THIS TIME
THE SUITE OF ENSEMBLE AND WPC GUIDANCE SHOWS THE PLAINS PORTION OF
THE ARCTIC AIRMASS SETTLING ONTO THE EAST SLOPES OF THE CENTRAL MT
CHAIN WHILE THE SECOND PORTION SHIFTS SOUTH THRU THE INTERMOUNTAIN
WEST. 700MB TEMPS BTWN -10 AND -14C WITH THIS AIRMASS ARE 1 TO 2
STANDARD DEVIATIONS BELOW CLIMO AND RESULTS IN HIGH TEMPS 15 TO 25
F BELOW NORMAL ALL AREAS. QPF AND SNOW IMPACTS WILL BE THE GREATEST
CHALLENGE WITH THIS SYSTEM. MODELS AGREE A BAND OF SNOW WILL SHIFT
SE OVER WESTERN NM WEDNESDAY THEN DISSIPATES WEDNESDAY NIGHT...WHILE
LOW CLOUDS AND LIGHT SNOW OR FLURRIES IMPACT THE EAST. THE GFS IS
THEN THE MOST BULLISH BREAKING OUT A LARGE AREA OF LIGHT/MODERATE
SNOW ALONG AND EAST OF THE CONT DVD THURSDAY THEN TAPERS OFF INTO
THE EAST FRIDAY. AT THIS TIME IMPACTS TO TRAVEL MAY BE HIGH WITH
EVEN LIGHT AMOUNTS OF PRECIP DUE TO THE SEVERITY OF THE COLD AND
BLOWING SNOW.
BELIEVE OR NOT MODELS ARE ADVERTISING AN EVEN COLDER SECOND ARCTIC
AIRMASS TO SHIFT SOUTH OVER THE WESTERN CONUS MONDAY AND TUESDAY OF
NEXT WEEK. 700MB TEMPS OVER NORTHERN NM ARE ADVERTISED BY THE ECMWF
TO FALL TO -24C WHICH IS EXCEPTIONALLY COLD. ANOTHER ROUND OF SNOW
IS ALSO ADVERTISED. GUYER
.FIRE WEATHER...
MAIN FIRE WEATHER ISSUES NEXT FEW DAYS WILL BE THE STRONG INVERSIONS
IN PLACE ACROSS ROUGHLY THE NW QUARTER TO THIRD OF THE STATE...
EMPHASIZING THE NW AND WEST CENTRAL VALLEYS TO THE WEST OF THE
CONTINENTAL DIVIDE. THIS WILL CONTINUE QUITE STRONG THROUGH TONIGHT
AND MON MORN...IMPROVING SOME MON AFTN AND RETURNING MORE WEAKLY MON
NIGHT INTO TUE MORN. AS A RESULT VENTILATION RATES TO REMAIN MAINLY
POOR IN THIS AREA THROUGH MON NIGHT. ACCOMPANYING THIS WILL BE VERY
LOW CLOUD DECK AND FREEZING FOG TONIGHT AND WELL INTO MON MORN.
OTHER SIGNIFICANT FIRE WX CONCERN WILL BE RISK OF MARGINALLY
CRITICAL FIRE WEATHER CONDITIONS FOR PERHAPS 2 OR 3 HOURS TUE AFTN
IN MAINLY SOUTHERN PORTION OF ZONE 108 IN EAST CENTRAL NM. MAIN
LIMITING ISSUE WILL BE THE MINIMUM RH.
OUTSIDE OF THE ABOVE MENTIONED AREAS...OVERNIGHT HUMIDITY RECOVERY
WILL STILL BE VERY GOOD TO EXCELLENT IN THE ESTANCIA AND UPPER RIO
GRANDE VALLEYS. HOWEVER...RECOVERIES WILL NOT BE AS HIGH IN THE
EASTERN PLAINS...MAINLY 45 TO 55 PERCENT. SCATTERED LOCALES ALONG
THE CENTRAL MOUNTAIN CHAIN AND CENTRAL HIGHLANDS WILL EXPERIENCE
BREEZY TO OCCASIONALLY WINDY CONDITIONS THROUGHOUT THE NIGHT AND
INTO MON. STILL...POOR VENTILATION/DISPERSION IS EXPECTED WEST OF
CENTRAL MTN CHAIN THROUGH MON NIGHT WITH TEMPERATURES RISING A
COUPLE TO SEVERAL DEGREES OVER TODAY. EAST OF CENTRAL MTN CHAIN
EXPECT FAIR TO LOCALLY VERY GOOD VENT RATES MON AFTN.
FLOW ALOFT BECOMES MORE WESTERLY MON NIGHT AND WEST SOUTHWESTERLY
BY TUE NIGHT AS LONGWAVE TROUGH ESTABLISHES TO THE WEST OF NM. AS
WINDS DRAMATICALLY INCREASE ALOFT THE 10000 FT LEVEL WINDS ARE
LIKELY TO REACH 45 TO 65 KT...PERHAPS EVEN A BIT HIGHER...ON MUCH OF
THE HIGHER TERRAIN. STRONG BUT RATHER SHALLOW BACK DOOR FRONT LIKELY
TO ENTER FAR NE NM LATE TUE OR EARLY WED WITH THE USUAL TIMING
DIFFERENCES BETWEEN THE MODELS. STRONG WINDS WILL REMAIN A CONCERN
FOR HIGH TERRAIN AREAS TUE. AHEAD OF THE FRONT THE EASTERN PLAINS
WOULD GET SOME DOWNSLOPING WARMING EFFECTS...AS TEMPS RUN 8 TO 15
DEGREES ABOVE AVERAGE WITH HUMIDITY OF 15 TO 20 PERCENT TUE AFTN.
BREEZY TO WINDY CONDITIONS WILL LIKELY PERSIST INTO WED...ESPECIALLY
THE HIGH TERRAIN ZONES...WHILE MUCH COLDER AIR SPILLS INTO THE STATE
FROM THE NE AND NW. SOME LIGHT TO LOCALLY MODERATE PRECIPITATION
WILL ALSO BE POSSIBLE ACROSS FCST AREA WED...SPREADING FARTHER EAST
THU AND FRI. PREFERRED AREAS WILL BE NW TWO THIRDS OF THE STATE. BY
THU THE ENTIRE FORECAST AREA TEMPS LIKELY TO FALL TO BETWEEN 10 AND
30 DEGREES BELOW AVERAGE. LITTLE IF ANY MODERATION FROM THE WELL
BELOW NORMAL TEMPS FRI. VENTILATION WILL SEE A MAJOR BOOST TUE AND
WED...BUT THEN STEADILY LOWER THU INTO FRI. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
40
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1136 AM MST SAT NOV 30 2013
.UPDATE...
LOW CLOUDS AND AREAS OF FOG ARE HANGING TOUGH ACROSS THE FOUR
CORNERS REGION. MODELS GENERALLY DO NOT HAVE A GOOD HANDLE ON WHEN
THE INVERSION WILL BREAK...BUT RUC SEEMS TO HAVE THE BETTER GRASP
OF ANY. INCREASED CLOUD COVER FOR THE AREA THROUGH THE
AFTERNOON...AND WITH THE EXPECTED CLOUD COVER...HAVE LOWERED TEMPS
A FEW DEGREES...ESPECIALLY FOR KFMN. UPDATES OUT SHORTLY.
34
&&
.PREV DISCUSSION...1109 AM MST SAT NOV 30 2013...
.AVIATION...
18Z TAF CYCLE
HIGH CIRRUS CLOUDS WILL STICK AROUND OVER THE SOUTHERN HALF TO
TWO THIRDS OF THE FORECAST AREA THROUGH THE NEXT 24 HOURS. LATEST
SATELLITE AND OBSERVATIONS SHOW SLOWLY IMPROVING CONDITIONS AT
GUP/FMN. THIS TREND SHOULD CONTINUE BUT THE MODELS HAVE HAD A HARD
TIME PREDICTING THE LIFR/IFR AND MVFR CONDTIONS. THESE CONDITIONS
SHOULD RETURN WITH ABUNDANT LOW LVL MOISTURE AND A STABLE
INVERSION TONIGHT. QUESTION IS WHEN. THINKING SLIGHTLY EARLIER
THAN LAST NIGHT AND THIS IS REFLECTED IN THE LATEST TERMINAL
FORECASTS AT GUP/FMN.
50
.PREV DISCUSSION...318 AM MST SAT NOV 30 2013...
LATEST GOES IMAGER FOG PRODUCT PICKING UP ON AN AREA OF FOG
ACROSS THE NORTHWEST PLATEAU...WEST OF THE DIVIDE TO NEAR GALLUP.
ONE QUARTER MILE VISIBILITY IN FREEZING FOG IN THE LATEST KFMN AND
KGUP OBS...LIKELY TO PERSIST BEYOND SUNRISE FOR A COUPLE OF HOURS.
STREAM OF PACIFIC MOISTURE RESULTING IN AN ELONGATED AREA OF DENSE
HIGH CLOUDS FROM THE EASTERN PACIFIC OCEAN...NORTHEAST ACROSS NW
MEXICO...SOUTHERN AZ AND NM MAKING FOR A TRICKY HIGH TEMPERATURE
FORECAST TODAY. THE UPPER FLOW TO BECOME MORE WESTERLY OVER THE
NEXT 24-36HRS...WHICH WILL CAUSE THE PACIFIC MOISTURE TAP TO SHIFT
SOUTH AND EAST OF OUR FORECAST AREA. HOWEVER...HIGH CLOUDS WILL
HANG AROUND AND MOVE ACROSS NM FROM THE NORTHWEST GOING INTO
MONDAY. BREEZY TO LOCALLY WINDY CONDITIONS FORECAST AS NW FLOW
INCREASES SUNDAY INTO MONDAY...WITH THE EAST SLOPES OF THE CENTRAL
MOUNTAIN CHAIN...ADJACENT HIGHLANDS AND PORTIONS OF THE EAST
CENTRAL PLAINS FAVORED FOR STRONGER WINDS.
WINDS ALOFT BACK FROM NW TO WSW TUESDAY INTO WEDNESDAY IN ADVANCE
OF A POTENT UPPER LEVEL TROUGH. TEMPS WILL TREND UP IN ADVANCE OF
THIS ANOMALOUSLY COLD SYNOPTIC WEATHER FEATURE AND WILL BE ABOVE
TO WELL ABOVE NORMAL TUESDAY AND TUESDAY NIGHT. A DEEPENING LEE
SIDE TROUGH WILL BE PARTIALLY RESPONSIBLE FOR INCREASING WINDS...
ESPECIALLY ACROSS THE NORTHEAST PLAINS AND HIGHLANDS.
TEMPS BEGIN A DOWNWARD TREND WEDNESDAY AS CLOUDS AND CHANCES FOR
PRECIPITATION TREND UP. A STRONG COLD FRONT TO MOVE EAST ACROSS
THE AREA LATE WEDNESDAY INTO THURSDAY...WITH A BACKDOOR PUSH DOWN
THE EASTERN PLAINS. WINDY CONDITIONS ARE FORECAST WEDNESDAY IN
ADVANCE OF AND IMMEDIATELY BEHIND THE COLD FRONT...MAY EVENT HIT
WIND ADVISORY THRESHOLDS IN A FEW SPOTS. PRECIP CHANCES LOOK TO
FAVOR THE NORTHERN AND WESTERN MOUNTAINS...ESPECIALLY WEDNESDAY AS
THE FRONT PUSHES THROUGH. SNOW ACCUMULATION MAY BE SIGNIFICANT
ENOUGH TO WARRANT ADVISORIES ACROSS THE NORTHERN MOUNTAINS. BOTH
THE LATEST ECMWF AND GFS SHOW THE UPPER LEVEL TROUGH AXIS PUSHING
THROUGH THURSDAY NIGHT INTO FRIDAY. THIS AIRMASS WILL LIKELY BE
THE COLDEST SO FAR THIS SEASON WITH THE LATEST MEDIUM RANGE MODELS
SHOWING NEAR -20C AT 700MB ALONG THE NM/CO BORDER BY 12Z FRIDAY.
THE BIG WEATHER STORY FROM LATE THURSDAY THROUGH INTO SATURDAY
WILL DEFINITELY BE THE WELL BELOW NORMAL TEMPERATURES.
11
.FIRE WEATHER...
A FEW MORE DAYS OF POOR VENTILATION WILL PLAGUE NORTHERN AND
CENTRAL NEW MEXICO BEFORE THE PATTERN SHIFTS TO A WINDIER ONE. A
CUT OFF LOW WILL STAY OVER THE EASTERN PACIFIC WATERS WITH HIGH
LEVEL MOISTURE STREAMING INTO NEW MEXICO TODAY. TEMPERATURES
SHOULD STILL REACH SEASONABLE AVERAGES FOR LATE NOVEMBER. LEE SIDE
SURFACE TROUGH WILL LOSE SOME STRENGTH BY AFTERNOON...AND THUS
AFTERNOON BREEZES WILL BE MODERATED IN EASTERN PARTS OF THE STATE
TODAY. THESE LIGHT WINDS AND STEEP INVERSIONS WILL PRODUCE THE
POOR MIXING AND INEFFICIENT DISPERSION. MINIMUM HUMIDITY WILL FALL
TO 25 TO 45 PERCENT ACROSS THE FORECAST AREA...RECOVERING TO 60 TO
80 PERCENT IN MOST OF THE EASTERN PLAINS TONIGHT AND UP TO 80 TO
100 PERCENT IN THE WEST THROUGH SUNDAY MORNING.
AS FLOW ALOFT TURNS MORE NORTHWESTERLY...A WEAK DISTURBANCE ALOFT
WILL SLIDE DOWN TOWARD NM TONIGHT AND SUNDAY...BUT THIS FEATURE
SHOULD POSE LITTLE ALTERATIONS TO THE OVERALL WEATHER ELEMENTS.
WHILE THE WINDS ALOFT WILL STRENGTHEN SOME SUNDAY AND
MONDAY...MIXING AND VENTILATION WILL STILL REMAIN POOR. LITTLE
TEMPERATURE VARIATION WILL ALSO BE NOTICED SUNDAY AND MONDAY.
BY TUESDAY FLOW ALOFT WILL BEGIN SHIFTING MORE SOUTHWESTERLY OVER NM
AS A TROUGH DEEPENS OVER THE WESTERN STATES. WINDS WILL INCREASE
SIGNIFICANTLY...ENOUGH TO IMPROVE VENTILATION BUT ALSO POTENTIALLY
INTRODUCING SOME NEAR-CRITICAL WINDS. AT THIS TIME FORECAST WIND
SPEEDS ARE BELOW CRITICAL CRITERIA...DUE TO SOME MODEL DISCREPANCIES
ON THE PLACEMENT OF THE LEE-SIDE SURFACE LOW. SHOULD MODELS CONVERGE
ON A MORE FAVORABLE PLACEMENT OF THIS FEATURE...WINDS MAY NEED TO BE
INCREASED. TEMPERATURES ARE EXPECTED TO STILL BE FAIRLY WARM ON
TUESDAY...ESPECIALLY IN THE EAST WITH DOWNSLOPING. HOWEVER...RH
FORECAST AT THIS TIME IS RESTING JUST ABOVE CRITICAL THRESHOLDS.
COOLER CONDITIONS AND BATCHES OF PRECIPITATION WILL BE SPREADING
INTO NM WEDNESDAY THROUGH THE END OF THE WORK WEEK AS THE BASE OF
THE AFOREMENTIONED TROUGH SWINGS THROUGH. WINDS WILL BE ELEVATED
THROUGH THIS PERIOD WITH BETTER VENTILATION...BUT NO CRITICAL
CONDITIONS ARE EXPECTED AS OF RIGHT NOW.
52
.AVIATION...
06Z TAF CYCLE
HIGH CLOUDS STREAMING NEWD AHEAD OF UPR LOW OFF SOCAL AND OVR NM.
SFC LEE TROF THRU 30/12Z THEN WK WND SHIFT EXPECTED IN THE ERN
PLNS AS SFC LOW SAGS SWD TO VCNTY KCVS. POTENTIAL FOR MVFR/IFR CIGS/VSBYS
FOUR CORNERS/KGUP REGION IN BR/FZFG PRIOR TO 15Z.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1036 PM EST SUN DEC 1 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SWING INTO THE GREAT LAKES
REGION TONIGHT AND SLOWLY LIFT INTO QUEBEC DURING THE DAY MONDAY.
HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND REMAIN OVER
THE AREA INTO WEDNESDAY BEFORE ANOTHER LOW AFFECTS THE REGION
MIDWEEK. HIGH PRESSURE RETURNS BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1021 PM EST SUNDAY...QUICK UPDATE TO ISSUE A FREEZING FOG
ADVISORY UNTIL 8 AM FOR THE CHAMPLAIN VALLEY EASTWARD ACROSS THE
REST OF VERMONT. WE`VE RECEIVED SEVERAL REPORTS OF LIGHT GLAZING
THIS EVENING IN THE AREAS OF FREEZING FOG AND MIST THAT HAVE
DEVELOPED ACROSS THE NORTH COUNTRY. IT APPEARS THAT LIGHT
NORTHERLY DRAINAGE FLOW (EVIDENT IN LOWER RAP MODEL 1000-950MB
THICKNESS FIELDS OVER THE CHAMPLAIN VALLEY) IS HELPING TO MAINTAIN
A PERSISTENT AREA OF FREEZING FOG HERE IN THE CHAMPLAIN VALLEY.
THE MAIN IMPACT FROM FREEZING FOG AND MIST WILL BE FROM
ICING...THOUGH VISIBILITIES AS LOW AS AN EIGHTH OF A MILE ARE
POSSIBLE IN AREAS OF FREEZING FOG.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 911 PM EST FOLLOWS...
EARLIER AREAS OF LIGHT SNOW HAVE GENERALLY COME TO AN END EXCEPT
FOR NORTHERN VERMONT AND INTO THE NORTHERN SAINT LAWRENCE VALLEY.
AREAS OF LIGHT SNOW LOOK TO LINGER THROUGH LATE EVENING/AROUND
MIDNIGHT IN THE NORTHEAST KINGDOM...AND CONTINUE PERIODICALLY
ACROSS THE NORTHERN SAINT LAWRENCE VALLEY AND `DACKS THROUGH
OVERNIGHT. HOWEVER...EXPECTING AREAS OF FREEZING DRIZZLE AND
PATCHY FREEZING FOG ACROSS A GOOD PORTION OF THE NORTH COUNTRY
THIS EVENING. POTENTIAL FOR FOG IS SHOWN NICELY ON BUFKIT
SOUNDINGS SHOWING A SATURATED NEAR-SFC LAYER...AND VERY LIGHT BL
FLOW IS ALSO ALLOWING FOR AREAS OF FREEZING MIST/FOG TO DEVELOP
(WITH VISIBILITIES RECENTLY AS LOW AS 1/4SM AT BTV AIRPORT). IN
ADDITION TO THE FOG...WV IMAGERY SHOWS DRY LAYER NOW ACROSS LAKE
ERIE MOVING EASTWARD. THE DRY LAYER ALOFT MAY PRODUCE PATCHY
FREEZING DRIZZLE THROUGH OVERNIGHT. A LIGHT WINTRY MESS TONIGHT
WITH OCCASIONAL PERIODS OF LIGHT SNOW...FREEZING FOG/MIST AND
AREAS OF FREEZING DRIZZLE. THESE CONDITIONS WILL LIKELY LEAD TO
SLIPPERY AREAS ON SIDEWALKS AND UNTREATED ROADWAYS AS WELL AS SOME
LIGHT GLAZING/RIMING ON TREES AND OTHER SURFACES OVERNIGHT. SEE
OUR SPECIAL WEATHER STATEMENT FOR MORE ON POTENTIALLY SLICK
ROADWAYS.
NO CHANGES TO CURRENT TEMPERATURES WITH READINGS GENERALLY STAYING
NEAR CURRENT VALUES THIS EVENING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...GOING INTO MONDAY...MDLS BRING SECONDARY
TROUGH INTO GREAT LKS REGION...ALLOWING FOR MORE DIGGING/
AMPLIFICATION OF THE REMNANTS OF CURRENT TROUGH. THE RESULT FOR
THE CWA WILL BE PERSISTENT SW FLOW OVER THE NORTH COUNTRY. PART OF
THIS FLOW WILL OCCUR OVER LK ONTARIO...KEEPING CHANCE FOR LIGHT
PRECIP OVER N NY THRU THE DAY...TAPERING TO JUST CLDY SKIES OVER
EASTERN AND SOUTHERN VT. POSSIBLE FOR A COUPLE TENTHS EXTRA -SW
ACCUM THRU THE DAY...BUT WITH TEMPS ABV NORMAL ON DECENT WAA...NOT
GOING TO LAST. TROUGH LIFTS INTO SOUTHERN QUEBEC MON
NGT...TAPERING OFF SL CHANCE WINTRY PRECIP TO NE KINGDOM BY
TUESDAY MORNING..THEN SFC RIDGE BUILDS OVER AREA FOR ANOTHER
DECENT DAY WITH TEMPS ABV NORMAL. HIGHS IN THE MID/UPPER 30S BOTH
DAYS...WITH OVERNGT LOWS ABV NORMAL BY SEVERAL DEGREES IN THE 20S.
WARMEST IN CVLY...COLDEST DACKS/NE VT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 413 PM EST SUNDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT
ON WEDNESDAY WITH SHOWING A RIDGE OF HIGH PRESSURE OVER THE
REGION. HOWEVER...MODELS SHOWING SOME TIMING DIFFERENCES WEDNESDAY
NIGHT WITH THE ARRIVAL OF PRECIPITATION AHEAD OF A FRONTAL SYSTEM.
HAVE OPTED TO GO WITH THE SLOWER TIMING OF THE ECMWF AND BRING IN
PRECIPITATION AFTER MIDNIGHT WEDNESDAY NIGHT. MODELS IN AGREEMENT
WITH HAVING PRECIPITATION OVER THE REGION ON THURSDAY.
HOWEVER...ECMWF MODEL KEEPS PRECIPITATION OVER THE REGION THURSDAY
NIGHT AS ECMWF SHOWING FRONTAL SYSTEM STALLING JUST SOUTH OF THE
REGION AS IT WILL BE PARALLEL TO THE UPPER FLOW...AS WEAK WAVES OF
LOW PRESSURE MOVE NORTHEAST ALONG THE FRONT. ECMWF SHOWING PLENTY
OF MOISTURE WILL STREAM NORTHEAST FROM THE LOWER MISSISSIPPI AND
TENNESSEE VALLEYS INTO THE REGION. HAVE LEANED TOWARD THE IDEA OF
THE ECMWF IN STALLING THE FRONTAL SYSTEM JUST SOUTH OF THE REGION
WITH PRECIPITATION ACROSS THE REGION FROM THURSDAY NIGHT THROUGH
SATURDAY. MUCH COLDER AIR WILL WORK INTO THE REGION SATURDAY AND
SUNDAY. ALSO...A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION
SATURDAY NIGHT AND SUNDAY WITH FAIR AND DRY WEATHER EXPECTED.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...AREAS OF LIGHT SNOW...MAINLY FROM THE CHAMPLAIN
VALLEY EWD...WILL CONTINUE THROUGH 03-04Z. THEREAFTER...IT APPEARS
SOME PATCHY FREEZING DRIZZLE WILL OCCUR FROM SHALLOW LOW STRATUS
DECK AT BTV/RUT/MPV WITH TEMPS AT TO SLIGHTLY BELOW FREEZING.
THIS MAY RESULT IN LIGHT ICING CONDITIONS FOR AIRPORT OPERATIONS
OVERNIGHT. ALSO ANTICIPATE IFR CEILINGS THRU 13-14Z MONDAY AT
MSS/MPV AND GENERALLY MVFR ELSEWHERE. WINDS LIGHT AND VARIABLE
OVERNIGHT...AND REMAINING 5 KTS OR LESS DURING THE DAYLIGHT HRS
MONDAY. CEILINGS GENERALLY MVFR (OVC015-025) DURING THE DAYLIGHT
HRS MONDAY BUT WITH LESS POTENTIAL FOR PRECIPITATION.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
00Z TUESDAY THROUGH 06Z THURSDAY...MAINLY VFR...WITH SOME LOCAL
POCKETS OF MVFR.
06Z THURSDAY THROUGH 00Z SATURDAY...AREAS OF MVFR/IFR IN RAIN AND SNOW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZING FOG ADVISORY UNTIL 8 AM EST MONDAY FOR VTZ001>012-
016>019.
NY...FREEZING FOG ADVISORY UNTIL 8 AM EST MONDAY FOR NYZ028-035.
&&
$$
SYNOPSIS...JN
NEAR TERM...LOCONTO
SHORT TERM...JN
LONG TERM...NEILES
AVIATION...BANACOS/WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1021 PM EST SUN DEC 1 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SWING INTO THE GREAT LAKES
REGION TONIGHT AND SLOWLY LIFT INTO QUEBEC DURING THE DAY MONDAY.
HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND REMAIN OVER
THE AREA INTO WEDNESDAY BEFORE ANOTHER LOW AFFECTS THE REGION
MIDWEEK. HIGH PRESSURE RETURNS BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1021 PM EST SUNDAY...QUICK UPDATE TO ISSUE A FREEZING FOG
ADVISORY UNTIL 8 AM FOR THE CHAMPLAIN VALLEY EASTWARD ACROSS THE
REST OF VERMONT. WE`VE RECEIVED SEVERAL REPORTS OF LIGHT GLAZING
THIS EVENING IN THE AREAS OF FREEZING FOG AND MIST THAT HAVE
DEVELOPED ACROSS THE NORTH COUNTRY. IT APPEARS THAT LIGHT
NORTHERLY DRAINAGE FLOW (EVIDENT IN LOWER RAP MODEL 1000-950MB
THICKNESS FIELDS OVER THE CHAMPLAIN VALLEY) IS HELPING TO MAINTAIN
A PERSISTENT AREA OF FREEZING FOG HERE IN THE CHAMPLAIN VALLEY.
THE MAIN IMPACT FROM FREEZING FOG AND MIST WILL BE FROM
ICING...THOUGH VISIBILITIES AS LOW AS AN EIGHTH OF A MILE ARE
POSSIBLE IN AREAS OF FREEZING FOG.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 911 PM EDT FOLLOWS...
EARLIER AREAS OF LIGHT SNOW HAVE GENERALLY COME TO AN END EXCEPT
FOR NORTHERN VERMONT AND INTO THE NORTHERN SAINT LAWRENCE VALLEY.
AREAS OF LIGHT SNOW LOOK TO LINGER THROUGH LATE EVENING/AROUND
MIDNIGHT IN THE NORTHEAST KINGDOM...AND CONTINUE PERIODICALLY
ACROSS THE NORTHERN SAINT LAWRENCE VALLEY AND `DACKS THROUGH
OVERNIGHT. HOWEVER...EXPECTING AREAS OF FREEZING DRIZZLE AND
PATCHY FREEZING FOG ACROSS A GOOD PORTION OF THE NORTH COUNTRY
THIS EVENING. POTENTIAL FOR FOG IS SHOWN NICELY ON BUFKIT
SOUNDINGS SHOWING A SATURATED NEAR-SFC LAYER...AND VERY LIGHT BL
FLOW IS ALSO ALLOWING FOR AREAS OF FREEZING MIST/FOG TO DEVELOP
(WITH VISIBILITIES RECENTLY AS LOW AS 1/4SM AT BTV AIRPORT). IN
ADDITION TO THE FOG...WV IMAGERY SHOWS DRY LAYER NOW ACROSS LAKE
ERIE MOVING EASTWARD. THE DRY LAYER ALOFT MAY PRODUCE PATCHY
FREEZING DRIZZLE THROUGH OVERNIGHT. A LIGHT WINTRY MESS TONIGHT
WITH OCCASIONAL PERIODS OF LIGHT SNOW...FREEZING FOG/MIST AND
AREAS OF FREEZING DRIZZLE. THESE CONDITIONS WILL LIKELY LEAD TO
SLIPPERY AREAS ON SIDEWALKS AND UNTREATED ROADWAYS AS WELL AS SOME
LIGHT GLAZING/RIMING ON TREES AND OTHER SURFACES OVERNIGHT. SEE
OUR SPECIAL WEATHER STATEMENT FOR MORE ON POTENTIALLY SLICK
ROADWAYS.
NO CHANGES TO CURRENT TEMPERATURES WITH READINGS GENERALLY STAYING
NEAR CURRENT VALUES THIS EVENING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...GOING INTO MONDAY...MDLS BRING SECONDARY
TROUGH INTO GREAT LKS REGION...ALLOWING FOR MORE DIGGING/
AMPLIFICATION OF THE REMNANTS OF CURRENT TROUGH. THE RESULT FOR
THE CWA WILL BE PERSISTENT SW FLOW OVER THE NORTH COUNTRY. PART OF
THIS FLOW WILL OCCUR OVER LK ONTARIO...KEEPING CHANCE FOR LIGHT
PRECIP OVER N NY THRU THE DAY...TAPERING TO JUST CLDY SKIES OVER
EASTERN AND SOUTHERN VT. POSSIBLE FOR A COUPLE TENTHS EXTRA -SW
ACCUM THRU THE DAY...BUT WITH TEMPS ABV NORMAL ON DECENT WAA...NOT
GOING TO LAST. TROUGH LIFTS INTO SOUTHERN QUEBEC MON
NGT...TAPERING OFF SL CHANCE WINTRY PRECIP TO NE KINGDOM BY
TUESDAY MORNING..THEN SFC RIDGE BUILDS OVER AREA FOR ANOTHER
DECENT DAY WITH TEMPS ABV NORMAL. HIGHS IN THE MID/UPPER 30S BOTH
DAYS...WITH OVERNGT LOWS ABV NORMAL BY SEVERAL DEGREES IN THE 20S.
WARMEST IN CVLY...COLDEST DACKS/NE VT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 413 PM EST SUNDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT
ON WEDNESDAY WITH SHOWING A RIDGE OF HIGH PRESSURE OVER THE
REGION. HOWEVER...MODELS SHOWING SOME TIMING DIFFERENCES WEDNESDAY
NIGHT WITH THE ARRIVAL OF PRECIPITATION AHEAD OF A FRONTAL SYSTEM.
HAVE OPTED TO GO WITH THE SLOWER TIMING OF THE ECMWF AND BRING IN
PRECIPITATION AFTER MIDNIGHT WEDNESDAY NIGHT. MODELS IN AGREEMENT
WITH HAVING PRECIPITATION OVER THE REGION ON THURSDAY.
HOWEVER...ECMWF MODEL KEEPS PRECIPITATION OVER THE REGION THURSDAY
NIGHT AS ECMWF SHOWING FRONTAL SYSTEM STALLING JUST SOUTH OF THE
REGION AS IT WILL BE PARALLEL TO THE UPPER FLOW...AS WEAK WAVES OF
LOW PRESSURE MOVE NORTHEAST ALONG THE FRONT. ECMWF SHOWING PLENTY
OF MOISTURE WILL STREAM NORTHEAST FROM THE LOWER MISSISSIPPI AND
TENNESSEE VALLEYS INTO THE REGION. HAVE LEANED TOWARD THE IDEA OF
THE ECMWF IN STALLING THE FRONTAL SYSTEM JUST SOUTH OF THE REGION
WITH PRECIPITATION ACROSS THE REGION FROM THURSDAY NIGHT THROUGH
SATURDAY. MUCH COLDER AIR WILL WORK INTO THE REGION SATURDAY AND
SUNDAY. ALSO...A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION
SATURDAY NIGHT AND SUNDAY WITH FAIR AND DRY WEATHER EXPECTED.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...AREAS OF LIGHT SNOW...MAINLY FROM THE CHAMPLAIN
VALLEY EWD...WILL CONTINUE THROUGH 03-04Z. THEREAFTER...IT APPEARS
SOME PATCHY FREEZING DRIZZLE WILL OCCUR FROM SHALLOW LOW STRATUS
DECK AT BTV/RUT/MPV WITH TEMPS AT TO SLIGHTLY BELOW FREEZING.
THIS MAY RESULT IN LIGHT ICING CONDITIONS FOR AIRPORT OPERATIONS
OVERNIGHT. ALSO ANTICIPATE IFR CEILINGS THRU 13-14Z MONDAY AT
MSS/MPV AND GENERALLY MVFR ELSEWHERE. WINDS LIGHT AND VARIABLE
OVERNIGHT...AND REMAINING 5 KTS OR LESS DURING THE DAYLIGHT HRS
MONDAY. CEILINGS GENERALLY MVFR (OVC015-025) DURING THE DAYLIGHT
HRS MONDAY BUT WITH LESS POTENTIAL FOR PRECIPITATION.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
00Z TUESDAY THROUGH 06Z THURSDAY...MAINLY VFR...WITH SOME LOCAL
POCKETS OF MVFR.
06Z THURSDAY THROUGH 00Z SATURDAY...AREAS OF MVFR/IFR IN RAIN AND SNOW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZING FOG ADVISORY UNTIL 8 AM EST MONDAY FOR VTZ001>012-
016>019.
NY...FREEZING FOG ADVISORY UNTIL 8 AM EST MONDAY FOR NYZ028-035.
&&
$$
SYNOPSIS...JN
NEAR TERM...LOCONTO
SHORT TERM...JN
LONG TERM...NEILES
AVIATION...BANACOS/WGH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
919 PM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP SOUTH OF THE AREA TONIGHT AND MOVE
NORTHEAST JUST OFF THE NORTH CAROLINA COAST MONDAY. THE LOW WILL
DEPART TO THE NORTHEAST TUESDAY AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE NORTHWEST THROUGH THE MIDDLE OF THE WEEK. THE HIGH
MOVES OFF THE COAST LATE IN THE WEEK THEN A COLD FRONT PUSHES
THROUGH THE AREA EARLY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 910 PM SUNDAY...HAVE MADE A FEW ADJUSTMENTS ON THIS UPDATE.
PRECIPITATION CONTINUES TO HUG THE COAST WITH MOST OF THE RAIN
OFFSHORE. THIS TREND IS BEING WELL DEPICTED BY THE 3 KM HRRR AND
LATEST RAP MODEL. HAVE CONFINED POPS OVERNIGHT TO THE COASTAL
SECTIONS AND HAVE DROPPED TO THE CHANCE RANGE. THE OTHER MAJOR
CHANGE IS WITH GENERALLY CLEAR SKIES INLAND...TEMPERATURES HAVE
DROPPED BELOW FORECAST LEVELS AND HAVE DROPPED MINIMUM
TEMPERATURES 3 TO 5 DEGREES ACROSS THE BOARD AWAY FROM THE COAST.
SOME RADIATIONAL FOG IS ALSO FORMING AT MANY LOCATIONS ACROSS THE
REGION.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
MOST PRECIP ASSOCD WITH THE AFOREMENTIONED SHORT WAVE AND COASTAL
SFC LOW SHUD FALL DURING THE MORNING HOURS THEN TAPERING OFF TO
MORE SPOTTY LIGHT PRECIP DURING THE AFTERNOON. AGAIN SIGNIFICANT
PRECIP MAY BE LIMITED TO MORE COASTAL AREAS WITH LIGHTER AND MORE
WIDESPREAD RAIN FARTHER INLAND. SKIES WILL REMAIN CLOUDY FOR MUCH
OF THE DAY IN THE INCREASING MOIST LOW LEVEL ONSHORE FLOW. EXPECT
TEMPS WILL REACH INTO THE LOW 60S ALONG THE COAST BUT ONLY MID 50S
OVER DEEP INLAND LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AS OF 330 PM SUN...LINGERING PRECIP POSSIBLE MON EVE BUT THE LOW
EAST OF CAPE HATTERAS WILL BE QUICKLY LIFTING NE BRINGING CLEARING
SKIES ACROSS ERN NC AS SFC HIGH PRES AND SHORTWAVE RIDGING BUILDS
ACROSS THE AREA. N/NW FLOW WILL BRING SLIGHTLY BELOW NORMAL TEMPS
WITH LOWS IN THE 30S INLAND TO 40S COAST MON NIGHT WITH HIGHS IN
THE 50S TUE.
A LONGWAVE NRN STREAM UPPER TROUGH DIGS ACROSS THE WRN CONUS
THROUGH THE LATTER HALF OF THE WEEK WHILE SW/NE ORIENTED UPPER
TROUGH AMPLIFIES ACROSS THE SRN GOM AND OFF THE SOUTHEAST COAST
BRINGING SW FLOW ALOFT ACROSS THE ERN CONUS. ABUNDANT PACIFIC
MOISTURE WILL BE TRANSPORTED ACROSS THE SOUTHERN PLAINS IN THE MID
ATLANTIC WHILE A SLOW MOVING COLD FRONT PUSHES ACROSS THE MID WEST
AND MID ATLANTIC STATES. DEEPEST MOISTURE AND BEST UPPER LEVEL
DYNAMICS WILL REMAIN NORTH AND WEST OF THE REGION AND EXPECT
MAINLY DRY CONDITIONS BUT WILL SEE INCREASED CLOUD COVER ACROSS
ERN NC. A FEW MODELS ARE DEPICTING LIGHT QPF TUE NIGHT INTO WED
AS AN AREA OF WEAK AND SHALLOW ISENTROPIC LIFT MOVES ACROSS THE
AREA BUT THINK THEY AREA OVERDONE AND WILL CONTINUE WITH MINIMAL
POPS. THE REGION WILL SEE A WARMING TREND AS THE SFC HIGH SLIDES
OFFSHORE WED WITH INCREASING SWLY FLOW THROUGH THE END OF THE
WEEK. HIGH EXPECTED IN THE 60S WED...LOW 70S THU AND MID 70S ON
FRIDAY WITH MILD OVERNIGHT LOWS.
THE COLD FRONT WILL APPROACH THE REGION FRI NIGHT AND...AT THE
PRESENT TIME...MODELS ARE IN FAIR AGREEMENT WITH THE COLD FRONT
PUSHING SE ACROSS THE REGION FROM ABOUT 12Z-20Z SAT. IMPROVING
UPPER LEVEL DYNAMICS AS THE RIGHT ENTRANCE REGION OF THE UPPER JET
MOVES CLOSER TO THE REGION AND FRONTAL FORCING WILL BRING
INCREASED POPS. A NON-DIURNAL TEMP TREND IS EXPECTED FRI NIGHT AND
SAT SWLY BRINGING MILD TEMPS FRI NIGHT AND TEMPS PEAKING SAT
MORNING...THEN FALLING BEHIND THE FRONT. RAIN CHANCES AND COOL
TEMPS CONTINUE INTO SUN AS ISENTROPIC LIFT CONTINUES IN MOIST
SW FLOW ALOFT OVER SFC HIGH PRES RIDGING IN FROM THE NORTH.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 18Z MONDAY/...
AS OF 915 PM SUNDAY...WITH THE PRECIPITATION REMAINING NEAR OR
JUST OFFSHORE...SKIES HAVE CLEARED AT ALL TAF SITES AND
RADIATIONAL FOG IS DEVELOPING. UPDATING TAFS TO INCLUDE PERIODS OF
IFR FOG AT ALL LOCATIONS.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM SUN...A LOW PRESSURE SYSTEM EAST OF CAPE HATTERAS
WILL LIFT NE MON NIGHT INTO TUE. SUB-VFR CONDITIONS MAY LINGER AT
COASTAL TAF SITES EARLY MON EVENING BUT EXPECT IMPROVING
CONDITIONS AS THE EVENING WEARS ON. PRED VFR CONDITIONS EXPECTED
MID WEEK AS HIGH PRESSURE BUILDS OVER THE AREA. MOISTURE INCREASES
FOR THE LATTER HALF OF THE WEEK AS HIGH PRES SLIDES OFFSHORE AND
SW FLOW INCREASES BUT EXPECT PRED VFR CONDITIONS OUTSIDE OF PATCHY
EARLY MORNING FOG/STRATUS. SHOWER CHANCES GRADUALLY INCREASES
FRIDAY AS A COLD FRONT APPROACHES FROM THE NW.
&&
.MARINE...
SHORT TERM /THROUGH MONDAY/...
AS OF 920 PM SUNDAY...NO MAJOR CHANGES ON THIS UPDATE FOR THE
MARINE WITH VARIABLE WINDS ON THE COASTAL WATERS AND SOUNDS
THROUGH THE EVENING...WITH WINDS BECOMING MORE N/NE LATER TONIGHT
AT SPEEDS LESS THAN 10 KT. WEAK LOW WILL DEVELOP TO THE S THIS
EVENING AND LIFT NE OFF THE NC COAST LATE TONIGHT AND ON MONDAY.
NE WINDS STEADILY INCREASE TO 10 TO 15 KT LATER TONIGHT AND EARLY
MONDAY THEN TO 15-20 KT COASTAL WATERS BY MON AFTERNOON. SEAS
MAINLY 2 TO 4 FT OVERNIGHT AND MONDAY MAY APPROACH 5 FT OUTER
WATERS BY LATE MONDAY AFTN.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM SUN...NW TO N WINDS AROUND 15-20 KT EXPECTED MON
NIGHT IN WAKE OF LOW WITH SEAS 3-5 FT NORTH AND 2-4 FT SOUTH.
WINDS DIMINISH TO BLO 15 KT AND SEAS SUBSIDE TO 2-4 FT THROUGHOUT
TUE AFTERNOON AND TUE NIGHT AS HIGH PRES BUILDS OVER THE AREA.
THE HIGH SLIDES OFFSHORE WED WITH LIGHT WINDS SHIFTING TO SW AND
GRADUALLY INCREASING THROUGH THE END OF THE WEEK AS PRES
GRADIENTS TIGHTEN IN RESPONSE TO A COLD FRONT SLOWLY APPROACHING
FROM THE NW. SCA CONDITIONS POSSIBLY DEVELOP THU NIGHT INTO FRI
WITH WINDS INCREASING TO 15-25 KT AND SEAS BUILD UP TO 4-6 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC
SHORT TERM...BTC
LONG TERM...SK
AVIATION...CTC/SK/BM
MARINE...CTC/BTC/SK
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
659 PM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP SOUTH OF THE AREA TONIGHT AND MOVE
NORTHEAST JUST OFF THE NORTH CAROLINA COAST MONDAY. THE LOW WILL
DEPART TO THE NORTHEAST TUESDAY AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE NORTHWEST THROUGH THE MIDDLE OF THE WEEK. THE HIGH
MOVES OFF THE COAST LATE IN THE WEEK THEN A COLD FRONT PUSHES
THROUGH THE AREA EARLY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 645 PM SUNDAY...SURFACE ANALYSIS SHOWING DEVELOPING SURFACE
LOW OFF THE SOUTH CAROLINA COAST. LIGHT PRECIPITATION ASSOCIATED
WITH THE LOW HAS BEEN CONFINED TO THE IMMEDIATE COAST WITH VERY
LIGHT AMOUNTS REPORTED ALONG THE CARTERET COUNTY COAST. LATEST
RUNS OF THE 3 KM HRRR AND RAP MODELS INDICATE THAT THE
PRECIPITATION WILL REMAIN NEAR THE COAST AND HAVE TRIMMED BACK
POPS OVER INLAND AREAS...BUT WILL CONTINUE LIKELY POPS RIGHT ALONG
THE COAST. NO OTHER BIG CHANGES OVERNIGHT. CLOUDS WILL LIMIT TEMP
DROP TONIGHT WITH 40 TO 45 INLAND AND UPPER 40S/LOW 50S
COAST...WITH THE EXCEPTION OF THE FAR NORTHWEST/NORTH COUNTIES
WHERE SKIES WILL BE CLEAR UNTIL LATE AND WILL TWEAK LOWS DOWN
THERE A BIT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
MOST PRECIP ASSOCD WITH THE AFOREMENTIONED SHORT WAVE AND COASTAL
SFC LOW SHUD FALL DURING THE MORNING HOURS THEN TAPERING OFF TO
MORE SPOTTY LIGHT PRECIP DURING THE AFTERNOON. AGAIN SIGNIFICANT
PRECIP MAY BE LIMITED TO MORE COASTAL AREAS WITH LIGHTER AND MORE
WIDESPREAD RAIN FARTHER INLAND. SKIES WILL REMAIN CLOUDY FOR MUCH
OF THE DAY IN THE INCREASING MOIST LOW LEVEL ONSHORE FLOW. EXPECT
TEMPS WILL REACH INTO THE LOW 60S ALONG THE COAST BUT ONLY MID 50S
OVER DEEP INLAND LOCATIONS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AS OF 330 PM SUN...LINGERING PRECIP POSSIBLE MON EVE BUT THE LOW
EAST OF CAPE HATTERAS WILL BE QUICKLY LIFTING NE BRINGING CLEARING
SKIES ACROSS ERN NC AS SFC HIGH PRES AND SHORTWAVE RIDGING BUILDS
ACROSS THE AREA. N/NW FLOW WILL BRING SLIGHTLY BELOW NORMAL TEMPS
WITH LOWS IN THE 30S INLAND TO 40S COAST MON NIGHT WITH HIGHS IN
THE 50S TUE.
A LONGWAVE NRN STREAM UPPER TROUGH DIGS ACROSS THE WRN CONUS
THROUGH THE LATTER HALF OF THE WEEK WHILE SW/NE ORIENTED UPPER
TROUGH AMPLIFIES ACROSS THE SRN GOM AND OFF THE SOUTHEAST COAST
BRINGING SW FLOW ALOFT ACROSS THE ERN CONUS. ABUNDANT PACIFIC
MOISTURE WILL BE TRANSPORTED ACROSS THE SOUTHERN PLAINS IN THE MID
ATLANTIC WHILE A SLOW MOVING COLD FRONT PUSHES ACROSS THE MID WEST
AND MID ATLANTIC STATES. DEEPEST MOISTURE AND BEST UPPER LEVEL
DYNAMICS WILL REMAIN NORTH AND WEST OF THE REGION AND EXPECT
MAINLY DRY CONDITIONS BUT WILL SEE INCREASED CLOUD COVER ACROSS
ERN NC. A FEW MODELS ARE DEPICTING LIGHT QPF TUE NIGHT INTO WED
AS AN AREA OF WEAK AND SHALLOW ISENTROPIC LIFT MOVES ACROSS THE
AREA BUT THINK THEY AREA OVERDONE AND WILL CONTINUE WITH MINIMAL
POPS. THE REGION WILL SEE A WARMING TREND AS THE SFC HIGH SLIDES
OFFSHORE WED WITH INCREASING SWLY FLOW THROUGH THE END OF THE
WEEK. HIGH EXPECTED IN THE 60S WED...LOW 70S THU AND MID 70S ON
FRIDAY WITH MILD OVERNIGHT LOWS.
THE COLD FRONT WILL APPROACH THE REGION FRI NIGHT AND...AT THE
PRESENT TIME...MODELS ARE IN FAIR AGREEMENT WITH THE COLD FRONT
PUSHING SE ACROSS THE REGION FROM ABOUT 12Z-20Z SAT. IMPROVING
UPPER LEVEL DYNAMICS AS THE RIGHT ENTRANCE REGION OF THE UPPER JET
MOVES CLOSER TO THE REGION AND FRONTAL FORCING WILL BRING
INCREASED POPS. A NON-DIURNAL TEMP TREND IS EXPECTED FRI NIGHT AND
SAT SWLY BRINGING MILD TEMPS FRI NIGHT AND TEMPS PEAKING SAT
MORNING...THEN FALLING BEHIND THE FRONT. RAIN CHANCES AND COOL
TEMPS CONTINUE INTO SUN AS ISENTROPIC LIFT CONTINUES IN MOIST
SW FLOW ALOFT OVER SFC HIGH PRES RIDGING IN FROM THE NORTH.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 18Z MONDAY/...
AS OF 655 PM SUNDAY...PER LATEST HIGH RES WRF MODELS...THE BULK OF
THE PRECIPITATION WILL REMAIN NEAR OR OFFSHORE AND WILL REMOVED
RAIN FROM THE TAFS. GIVEN THIS TREND...WILL KEEP CEILING JUST
ABOVE 3000 FEET IN THE VFR RANGE THROUGH THE PERIOD. WILL INDICATE
A PERIOD OF MVFR FOG LATE TONIGHT/EARLY MONDAY AT THE KEWN/KOAJ
SITES.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM SUN...A LOW PRESSURE SYSTEM EAST OF CAPE HATTERAS
WILL LIFT NE MON NIGHT INTO TUE. SUB-VFR CONDITIONS MAY LINGER AT
COASTAL TAF SITES EARLY MON EVENING BUT EXPECT IMPROVING
CONDITIONS AS THE EVENING WEARS ON. PRED VFR CONDITIONS EXPECTED
MID WEEK AS HIGH PRESSURE BUILDS OVER THE AREA. MOISTURE INCREASES
FOR THE LATTER HALF OF THE WEEK AS HIGH PRES SLIDES OFFSHORE AND
SW FLOW INCREASES BUT EXPECT PRED VFR CONDITIONS OUTSIDE OF PATCHY
EARLY MORNING FOG/STRATUS. SHOWER CHANCES GRADUALLY INCREASES
FRIDAY AS A COLD FRONT APPROACHES FROM THE NW.
&&
.MARINE...
SHORT TERM /THROUGH MONDAY/...
AS OF 655 PM SUNDAY...HAVE GONE WITH VARIABLE WINDS ON THE COASTAL
WATERS AND SOUNDS THROUGH THE EVENING...WITH WINDS BECOMING MORE
N/NE LATER TONIGHT AT SPEEDS LESS THAN 10 KT. WEAK LOW WILL
DEVELOP TO THE S THIS EVENING AND LIFT NE OFF THE NC COAST LATE
TONIGHT AND ON MONDAY. NE WINDS STEADILY INCREASE TO 10 TO 15 KT
LATER TONIGHT AND EARLY MONDAY THEN TO 15-20 KT COASTAL WATERS BY
MON AFTERNOON. SEAS MAINLY 2 TO 4 FT OVERNIGHT AND MONDAY MAY
APPROACH 5 FT OUTER WATERS BY LATE MONDAY AFTN.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM SUN...NW TO N WINDS AROUND 15-20 KT EXPECTED MON
NIGHT IN WAKE OF LOW WITH SEAS 3-5 FT NORTH AND 2-4 FT SOUTH.
WINDS DIMINISH TO BLO 15 KT AND SEAS SUBSIDE TO 2-4 FT THROUGHOUT
TUE AFTERNOON AND TUE NIGHT AS HIGH PRES BUILDS OVER THE AREA.
THE HIGH SLIDES OFFSHORE WED WITH LIGHT WINDS SHIFTING TO SW AND
GRADUALLY INCREASING THROUGH THE END OF THE WEEK AS PRES
GRADIENTS TIGHTEN IN RESPONSE TO A COLD FRONT SLOWLY APPROACHING
FROM THE NW. SCA CONDITIONS POSSIBLY DEVELOP THU NIGHT INTO FRI
WITH WINDS INCREASING TO 15-25 KT AND SEAS BUILD UP TO 4-6 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC
SHORT TERM...BTC
LONG TERM...SK
AVIATION...CTC/SK/BM
MARINE...CTC/BTC/SK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1248 PM EST SAT NOV 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND SOUTHWEST INTO THE REGION THROUGH
TONIGHT...THEN WEAKEN ON SUNDAY. A LOW PRESSURE SYSTEM IS EXPECTED
TO DEVELOP ALONG THE CAROLINA COAST ON MONDAY AS AN UPPER LEVEL
DISTURBANCE APPROACHES FROM THE WEST.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1050 AM SATURDAY...
SURFACE HIGH AS OF 15Z IS CENTERED WELL TO THE NORTHEAST...OVER NEW
ENGLAND AND INTO MAINE...WITH THE RIDGE AXIS EXTENDING SOUTHWEST INTO
NC...MAINLY ALONG THE WESTERN PORTION OF THE AREA. THE PRESSURE
GRADIENT WILL RELAX SOME AS THE HIGH MOVES OFF THE NE COAST AND THE
RIDGE WEAKENS...THUS ALLOWING THE WINDS TO RELAX SOME AS WELL. THE
RETURN FLOW WILL BECOME MORE NORTHEASTERLY AS THAT HAPPENS...
ALLOWING FOR WARMER TEMPS ACROSS THE SOUTH AND EAST AND COOLER IN
THE NW. THE 12Z UPPER AIR ANALYSES SHOW THE TROUGH... MORE PROMINENT
AT 700 AND 850 MB...EXTENDING FROM THE WESTERN GREAT LAKES SW INTO
OK/TX...WITH HIGH PRESSURE/RIDGING OVER THE EASTERN US. AN UPPER
LEVEL WAVE JUST WEST OF THE APPALACHIANS...SHOWN IN BOTH SATELLITE
IMAGERY AND INDICATED BY MODEL GENERATED VORTICITY PLOTS...IS
GENERATING AN AREA OF CLOUDS OVER WV/VA...WHICH MAY EXTEND INTO THE
NORTHERN AND WESTERN PORTIONS OF THE AREA TODAY...ALTHOUGH THE
GREATEST COVERAGE WILL BE OVER VA. WITH THE STRONG WESTERLY FLOW
ALOFT EXPECTED TO CONTINUE TODAY AS THE UPPER LEVEL RIDGE CONTINUES
TO BUILD...SUBSIDENCE SHOULD BE STRONG ENOUGH TO LIMIT MIXING IN THE
LOW LEVELS...WHICH IN COMBINATION WITH THE INCREASING CLOUD COVER...
SHOULD BE ENOUGH TO YIELD HIGHS TODAY A BIT COOLER THAN YESTERDAY...
MAINLY IN THE MID 40S TO LOW 50S. -KC
THE LATEST RAP...ALONG WITH THE HRRR WRF...FORECAST AN INCREASE IN
LOW-LEVEL MOISTURE FROM THE SOUTHEAST LATE IN THE DAY. THIS MAY BE
REASONABLE...AS THE SATELLITE FOG PRODUCT SHOWED AREAS OF LOW CLOUDS
JUST OFFSHORE FROM SOUTHEAST NORTH CAROLINA EARLY THIS MORNING. HAVE
ADDED SOME CLOUD COVER TO THE FORECAST PARTICULARLY TOWARD THE SOUTH
AND EAST DURING THE AFTERNOON. -DJF
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 650 AM SATURDAY...
SURFACE HIGH PRESSURE SHOULD BE DIRECTLY OVERHEAD OVERNIGHT KEEPING
THE GRADIENT VERY RELAXED. THE POTENTIAL FOR A QUITE CHILLY NIGHT
WOULD EXIST BUT THE COMBINATION OF SOME HIGH CLOUDS AND THE GFS
FORECAST OF INCREASING 850MB MOISTURE FROM THE SOUTH AND SOUTHWEST
MAY ACT TO KEEP TEMPERATURES CLOSE TO THE GUIDANCE LOWS OVERNIGHT.
THE LATEST SATELLITE FOG PRODUCT SHOWS LOW-LEVEL MOISTURE MOVING
WEST TOWARD THE SOUTH CAROLINA COAST...AND LOW-LEVEL ISENTROPIC
FORECASTS ALONG WITH THE INCREASING 850MB MOISTURE SUPPORT AN
INCREASE IN CLOUD COVER TO PARTLY-TO-MOSTLY CLOUDY PARTICULARLY
ALONG AND SOUTH OF ABOUT INTERSTATE 85 DURING THE OVERNIGHT HOURS.
THE TIMING OF THIS IS...OF COURSE...CRITICAL TO THE OVERNIGHT
TEMPERATURE FORECAST...BUT FOR THIS FORECAST WILL LEAN TOWARD THE
COOLER MOS GUIDANCE IN THE TRIAD AND THE WARMER MOS GUIDANCE
ELSEWHERE.
K INDICES SLOWLY RISE SUNDAY...WITH PRECIPITABLE WATER VALUES RISING
LATE SUNDAY TO BETWEEN 0.75 AND ONE INCH...ABOVE NORMAL FOR VERY
EARLY DECEMBER AT ABOUT THE 75TH PERCENTILE. LIFT STARTS TO INCREASE
LATE SUNDAY AND PARTICULARLY SUNDAY NIGHT AS ISENTROPIC LIFT ON THE
300K SURFACE INCREASES...WITH THE BEST POTENTIAL VORTICITY ON THE
1.5PVU SURFACE FORECAST BY THE GFS ALONG AND SOUTH OF ABOUT U.S. 64
LATE SUNDAY THROUGH SUNDAY NIGHT. SURFACE DEPICTIONS OF THE NAM AND
GFS DIFFER AND ARE FAIRLY CONSISTENT WITH THEMSELVES OVER THE LAST
TWO OR THREE RUNS...WITH THE NAM SHOWING A WEAK SURFACE LOW JUST OFF
THE SOUTH CAROLINA COAST SUNDAY NIGHT WHILE THE GFS FORECASTS MORE
OF AN INVERTED TROUGH BEFORE SURFACE LOW PRESSURE STRENGTHENS
OFFSHORE. REGARDLESS...QPF AND MOS GUIDANCE POPS ARE SIMILAR...
KEEPING MOST CHANCES FOR PRECIPITATION AT BAY SUNDAY AND INCREASING
CHANCES OVER MOST OF CENTRAL NORTH CAROLINA SUNDAY NIGHT. WILL NOTE
A SLIGHT CHANCE OF RAIN MAINLY OVER THE SANDHILLS AND SOUTHERN
COASTAL PLAIN SUNDAY WHERE THE BEST LOW-LEVEL MOISTURE SHOULD RESIDE
AS POTENTIAL VORTICITY INCREASES...WITH A CHANCE OF RAIN SUNDAY
NIGHT MAINLY ALONG AND EAST OF A LINE FROM ABOUT KIXA TO KAFP WITH A
SLIGHT CHANCE NORTH OF THAT LINE. DEBATED WHETHER OR NOT TO INCLUDE
A SLIGHT CHANCE IN THE TRIAD AND FOR THIS FORECAST WILL SHOW A VERY
LOW SLIGHT CHANCE THERE OVERNIGHT SUNDAY...THOUGH THIS COULD END UP
BEING OVERDONE WITH SUFFICIENT MOISTURE AND LIFT REMAINING JUST
EAST. SURFACE WET BULB TEMPERATURES AND PARTIAL THICKNESSES SUPPORT
ALL LIQUID.
ONCE AGAIN 1000-850MB THICKNESSES WOULD SUPPORT HIGHS SUNDAY ABOVE
MOS GUIDANCE...BUT GIVEN THE EXPECTED CLOUD COVER...WILL FORECAST
HIGHS AS A BLEND OF MAV AND MET MOS GUIDANCE FOR A FAIRLY UNIFORM
LOWER 50S IN MOST LOCATIONS. OVERNIGHT SUNDAY...IF IT REMAINS DRY IN
THE TRIAD LOWS SHOULD BE NEAR THE WARMER GUIDANCE...WHILE WHERE IT
RAINS TEMPERATURES WOULD APPROACH THE DEW POINT. THIS COINCIDES WITH
A BLEND OF MOS GUIDANCE...ALTHOUGH HIGHER THAN GUIDANCE TOWARD
KRWI...FOR LOWS IN THE MID TO UPPER 30S NORTHWEST...TO MID 40S
TOWARD KCTZ.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 235 AM SATURDAY...
ON MONDAY A LOW AMPLITUDE NORTHERN STREAM SHORTWAVE DROPS INTO THE
THE DEEP SOUTH AS A SHEARING SOUTHERN STREAM SYSTEM WITH A 250MB JET
OF 140 KTS PHASE TOGETHER BEFORE THE TROUGH AXIS MOVES OFF THE
SOUTHEAST COAST MONDAY NIGHT. THE TROUGH BECOMES NEGATIVELY TILTED
AND INITIATES SURFACE CYCLOGENESIS MONDAY NIGHT AND TUESDAY. RECENT
NWP TRENDS HAVE SUGGESTED A LESS AMPLIFIED SYSTEM WHILE PRODUCING A
BIT MORE QPF ACROSS MAINLY SOUTHEASTERN NC. IT REMAINS DIFFICULT AND
CONFIDENCE IS LOW REGARDING HOW FAR NORTH AND WEST PRECIPITATION
WILL SPREAD ACROSS CENTRAL NC BUT CONFIDENCE IS GROWING THAT SOME
LIGHT PRECIPITATION WILL FALL ACROSS THE SOUTHERN COASTAL PLAIN AND
SANDHILLS REGION. NWP CONSENSUS SHOWS THE DEEPEST MOISTURE AND
STRONGEST FORCING WILL BE CONFINED TO SOUTHEASTERN PORTIONS OF THE
RAH CWA WITH RAPIDLY DECREASING RAIN CHANCES ACROSS THE NORTHERN AND
WESTERN PIEDMONT. ISENTROPIC ANALYSIS DEPICTS THE PATTERN WELL WITH
A FAIRLY NARROW CORRIDOR OF LIFT/SATURATION THAT SLIDES MAINLY
ACROSS SOUTHERN AND EASTERN NC. PRECIPITATION CHANCES QUICKLY TAIL
OFF FROM WEST TO EAST ON MONDAY NIGHT. THE AIR MASS AHEAD OF THE
SYSTEM WILL HAVE MODIFIED AND THE PRECIPITATION WILL FALL AS RAIN.
GIVEN THE MODIFICATION OF THE AIR MASS AND THE LIGHT PRECIPITATION
CHANCES...DO NOT EXPECT A SIGNIFICANT CAD EVENT TO OCCUR. HIGHS
MONDAY WILL RANGE IN THE 49-56 RANGE WITH MAX TEMPERATURES DEPENDENT
ON THE LOCATION AND INTENSITY OF THE PRECIPITATION.
AFTER THE UPPER TROUGH AXIS MOVES OFFSHORE...THE FLOW ALOFT BECOMES
MORE NORTHWESTERLY. ANOTHER DISTURBANCE IN THE FLOW AND SOME
RESIDUAL MOISTURE SHOULD BE SUFFICIENT TO PRODUCE SOME CLOUDINESS ON
TUESDAY BUT OTHERWISE FAIR CONDITIONS ARE EXPECTED WITH HIGHS IN THE
LOWER TO MID 50S.
THE FLOW FLATTENS ON TUESDAY NIGHT AND HEIGHTS RISE ON WEDNESDAY
INTO THURSDAY WITH INCREASING HIGH CLOUDS LATE WEDNESDAY AND A FAIR
AMOUNT OF CLOUDS EXPECTED ON THURSDAY. EXPECT DRY WEATHER THROUGH AT
LEAST THURSDAY AFTERNOON AS THE RIDGE AXIS BUILDS OVERHEAD.
MODERATING TEMPERATURES ARE EXPECTED ON THURSDAY INTO FRIDAY WITH
HIGHS IN THE MID TO UPPER 50S ON WEDNESDAY WARMING INTO THE UPPER
50S TO LOWER 60S ON THURSDAY WITH MORNING LOWS IN THE MID 30S TO
AROUND 40.
A LONGWAVE TROUGH DEVELOPS OVER THE WESTERN U.S. LATE THURSDAY INTO
FRIDAY AS AN ARCTIC AIRMASS DROPS INTO THE NORTHERN ROCKIES AND
NORTHERN PLAINS. AN INCREASINGLY MOIST SOUTHERLY TO SOUTHWESTERLY
FLOW DEVELOPS ACROSS THE CENTRAL U.S. AS THE TROUGH PUSHES EAST ON
FRIDAY. THE ASSOCIATED COLD FRONT REACHES THE WESTERN APPALACHIANS
ON FRIDAY MORNING. THERE ARE TIMING DIFFERENCES AMONG THE GUIDANCE
REGARDING THE EASTWARD ADVANCEMENT OF THE FRONT AND THE ASSOCIATED
PRECIPITATION WITH WPC PREFERRING A GEFS MEAN AND EC ENS MEAN.
REGARDLESS...THE THREAT OF RAIN WILL ARRIVE WITH LOW PROBABILITIES
IN THE WEST LATE THURSDAY NIGHT. POPS WILL INCREASE FROM WEST TO
EAST FRIDAY AND FRIDAY NIGHT WITH THE BEST CHANCE OF RAIN AT THIS
POINT APPEARING TO BE FRIDAY NIGHT AND SATURDAY. AHEAD OF THE FRONT
AND THE RAIN...TEMPERATURES ARE LIKELY TO CLIMB INTO THE 60S FRIDAY
AFTERNOON. -BLAES
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1245 PM SATURDAY...
24 HOUR TAF PERIOD: HIGH CONFIDENCE OF CONTINUED VFR CONDITIONS
THROUGH THIS AFTERNOON AND EVENING WITH THE RIDGE EXTENDING INTO NC
AND LIGHT NW WINDS. STILL EXPECT AN INCREASE IN LOW LEVEL MOISTURE
ACROSS THE COASTAL PLAIN OVERNIGHT AND INTO SUNDAY MORNING... WHICH
COULD YIELD A PERIOD OF SUB-VFR CONDITIONS...MAINLY AT KFAY...AND
POSSIBLY AT KRWI (LESS LIKELY TOWARD KRDU) AND POINTS ALONG AND
SOUTHEAST OF THERE. ALTHOUGH THE WINDS WILL BE LIGHT...THEY WILL BE
SLOWLY BACKING FROM PREDOMINANTLY NORTH AND NORTHEAST TO WEST AND
NORTHWEST BY THE END OF THE TAF PERIOD.
LOOKING AHEAD: EXPECT MOISTURE ADVECTION INTO THE AREA SUNDAY NIGHT
TO LEAD TO INCREASING CLOUD COVER AND THE CHANCE FOR RAIN. THERE IS
A GOOD CHANCE FOR SUB-VFR CONDITIONS DURING THIS TIME. EXPECT THE
ATMOSPHERE TO DRY FROM THE TOP DOWN ON TUESDAY...LIKELY IMPROVING
AVIATION CONDITIONS TO VFR FOR THE REMAINDER OF TUESDAY AND INTO
WEDNESDAY. SUB-VFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY NIGHT
INTO THURSDAY AS SOUTHERLY FLOW ADVECTS MOISTURE INTO CENTRAL NC.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/DJF
SHORT TERM...DJF
LONG TERM...BLAES
AVIATION...KC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1051 AM EST SAT NOV 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND SOUTHWEST INTO THE REGION THROUGH
TONIGHT...THEN WEAKEN ON SUNDAY. A LOW PRESSURE SYSTEM IS EXPECTED
TO DEVELOP ALONG THE CAROLINA COAST ON MONDAY AS AN UPPER LEVEL
DISTURBANCE APPROACHES FROM THE WEST.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1050 AM SATURDAY...
SURFACE HIGH AS OF 15Z IS CENTERED WELL TO THE NORTHEAST...OVER NEW
ENGLAND AND INTO MAINE...WITH THE RIDGE AXIS EXTENDING SOUTHWEST INTO
NC...MAINLY ALONG THE WESTERN PORTION OF THE AREA. THE PRESSURE
GRADIENT WILL RELAX SOME AS THE HIGH MOVES OFF THE NE COAST AND THE
RIDGE WEAKENS...THUS ALLOWING THE WINDS TO RELAX SOME AS WELL. THE
RETURN FLOW WILL BECOME MORE NORTHEASTERLY AS THAT HAPPENS...
ALLOWING FOR WARMER TEMPS ACROSS THE SOUTH AND EAST AND COOLER IN
THE NW. THE 12Z UPPER AIR ANALYSES SHOW THE TROUGH... MORE PROMINENT
AT 700 AND 850 MB...EXTENDING FROM THE WESTERN GREAT LAKES SW INTO
OK/TX...WITH HIGH PRESSURE/RIDGING OVER THE EASTERN US. AN UPPER
LEVEL WAVE JUST WEST OF THE APPALACHIANS...SHOWN IN BOTH SATELLITE
IMAGERY AND INDICATED BY MODEL GENERATED VORTICITY PLOTS...IS
GENERATING AN AREA OF CLOUDS OVER WV/VA...WHICH MAY EXTEND INTO THE
NORTHERN AND WESTERN PORTIONS OF THE AREA TODAY...ALTHOUGH THE
GREATEST COVERAGE WILL BE OVER VA. WITH THE STRONG WESTERLY FLOW
ALOFT EXPECTED TO CONTINUE TODAY AS THE UPPER LEVEL RIDGE CONTINUES
TO BUILD...SUBSIDENCE SHOULD BE STRONG ENOUGH TO LIMIT MIXING IN THE
LOW LEVELS...WHICH IN COMBINATION WITH THE INCREASING CLOUD COVER...
SHOULD BE ENOUGH TO YIELD HIGHS TODAY A BIT COOLER THAN YESTERDAY...
MAINLY IN THE MID 40S TO LOW 50S. -KC
THE LATEST RAP...ALONG WITH THE HRRR WRF...FORECAST AN INCREASE IN
LOW-LEVEL MOISTURE FROM THE SOUTHEAST LATE IN THE DAY. THIS MAY BE
REASONABLE...AS THE SATELLITE FOG PRODUCT SHOWED AREAS OF LOW CLOUDS
JUST OFFSHORE FROM SOUTHEAST NORTH CAROLINA EARLY THIS MORNING. HAVE
ADDED SOME CLOUD COVER TO THE FORECAST PARTICULARLY TOWARD THE SOUTH
AND EAST DURING THE AFTERNOON. -DJF
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 650 AM SATURDAY...
SURFACE HIGH PRESSURE SHOULD BE DIRECTLY OVERHEAD OVERNIGHT KEEPING
THE GRADIENT VERY RELAXED. THE POTENTIAL FOR A QUITE CHILLY NIGHT
WOULD EXIST BUT THE COMBINATION OF SOME HIGH CLOUDS AND THE GFS
FORECAST OF INCREASING 850MB MOISTURE FROM THE SOUTH AND SOUTHWEST
MAY ACT TO KEEP TEMPERATURES CLOSE TO THE GUIDANCE LOWS OVERNIGHT.
THE LATEST SATELLITE FOG PRODUCT SHOWS LOW-LEVEL MOISTURE MOVING
WEST TOWARD THE SOUTH CAROLINA COAST...AND LOW-LEVEL ISENTROPIC
FORECASTS ALONG WITH THE INCREASING 850MB MOISTURE SUPPORT AN
INCREASE IN CLOUD COVER TO PARTLY-TO-MOSTLY CLOUDY PARTICULARLY
ALONG AND SOUTH OF ABOUT INTERSTATE 85 DURING THE OVERNIGHT HOURS.
THE TIMING OF THIS IS...OF COURSE...CRITICAL TO THE OVERNIGHT
TEMPERATURE FORECAST...BUT FOR THIS FORECAST WILL LEAN TOWARD THE
COOLER MOS GUIDANCE IN THE TRIAD AND THE WARMER MOS GUIDANCE
ELSEWHERE.
K INDICES SLOWLY RISE SUNDAY...WITH PRECIPITABLE WATER VALUES RISING
LATE SUNDAY TO BETWEEN 0.75 AND ONE INCH...ABOVE NORMAL FOR VERY
EARLY DECEMBER AT ABOUT THE 75TH PERCENTILE. LIFT STARTS TO INCREASE
LATE SUNDAY AND PARTICULARLY SUNDAY NIGHT AS ISENTROPIC LIFT ON THE
300K SURFACE INCREASES...WITH THE BEST POTENTIAL VORTICITY ON THE
1.5PVU SURFACE FORECAST BY THE GFS ALONG AND SOUTH OF ABOUT U.S. 64
LATE SUNDAY THROUGH SUNDAY NIGHT. SURFACE DEPICTIONS OF THE NAM AND
GFS DIFFER AND ARE FAIRLY CONSISTENT WITH THEMSELVES OVER THE LAST
TWO OR THREE RUNS...WITH THE NAM SHOWING A WEAK SURFACE LOW JUST OFF
THE SOUTH CAROLINA COAST SUNDAY NIGHT WHILE THE GFS FORECASTS MORE
OF AN INVERTED TROUGH BEFORE SURFACE LOW PRESSURE STRENGTHENS
OFFSHORE. REGARDLESS...QPF AND MOS GUIDANCE POPS ARE SIMILAR...
KEEPING MOST CHANCES FOR PRECIPITATION AT BAY SUNDAY AND INCREASING
CHANCES OVER MOST OF CENTRAL NORTH CAROLINA SUNDAY NIGHT. WILL NOTE
A SLIGHT CHANCE OF RAIN MAINLY OVER THE SANDHILLS AND SOUTHERN
COASTAL PLAIN SUNDAY WHERE THE BEST LOW-LEVEL MOISTURE SHOULD RESIDE
AS POTENTIAL VORTICITY INCREASES...WITH A CHANCE OF RAIN SUNDAY
NIGHT MAINLY ALONG AND EAST OF A LINE FROM ABOUT KIXA TO KAFP WITH A
SLIGHT CHANCE NORTH OF THAT LINE. DEBATED WHETHER OR NOT TO INCLUDE
A SLIGHT CHANCE IN THE TRIAD AND FOR THIS FORECAST WILL SHOW A VERY
LOW SLIGHT CHANCE THERE OVERNIGHT SUNDAY...THOUGH THIS COULD END UP
BEING OVERDONE WITH SUFFICIENT MOISTURE AND LIFT REMAINING JUST
EAST. SURFACE WET BULB TEMPERATURES AND PARTIAL THICKNESSES SUPPORT
ALL LIQUID.
ONCE AGAIN 1000-850MB THICKNESSES WOULD SUPPORT HIGHS SUNDAY ABOVE
MOS GUIDANCE...BUT GIVEN THE EXPECTED CLOUD COVER...WILL FORECAST
HIGHS AS A BLEND OF MAV AND MET MOS GUIDANCE FOR A FAIRLY UNIFORM
LOWER 50S IN MOST LOCATIONS. OVERNIGHT SUNDAY...IF IT REMAINS DRY IN
THE TRIAD LOWS SHOULD BE NEAR THE WARMER GUIDANCE...WHILE WHERE IT
RAINS TEMPERATURES WOULD APPROACH THE DEW POINT. THIS COINCIDES WITH
A BLEND OF MOS GUIDANCE...ALTHOUGH HIGHER THAN GUIDANCE TOWARD
KRWI...FOR LOWS IN THE MID TO UPPER 30S NORTHWEST...TO MID 40S
TOWARD KCTZ.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 235 AM SATURDAY...
ON MONDAY A LOW AMPLITUDE NORTHERN STREAM SHORTWAVE DROPS INTO THE
THE DEEP SOUTH AS A SHEARING SOUTHERN STREAM SYSTEM WITH A 250MB JET
OF 140 KTS PHASE TOGETHER BEFORE THE TROUGH AXIS MOVES OFF THE
SOUTHEAST COAST MONDAY NIGHT. THE TROUGH BECOMES NEGATIVELY TILTED
AND INITIATES SURFACE CYCLOGENESIS MONDAY NIGHT AND TUESDAY. RECENT
NWP TRENDS HAVE SUGGESTED A LESS AMPLIFIED SYSTEM WHILE PRODUCING A
BIT MORE QPF ACROSS MAINLY SOUTHEASTERN NC. IT REMAINS DIFFICULT AND
CONFIDENCE IS LOW REGARDING HOW FAR NORTH AND WEST PRECIPITATION
WILL SPREAD ACROSS CENTRAL NC BUT CONFIDENCE IS GROWING THAT SOME
LIGHT PRECIPITATION WILL FALL ACROSS THE SOUTHERN COASTAL PLAIN AND
SANDHILLS REGION. NWP CONSENSUS SHOWS THE DEEPEST MOISTURE AND
STRONGEST FORCING WILL BE CONFINED TO SOUTHEASTERN PORTIONS OF THE
RAH CWA WITH RAPIDLY DECREASING RAIN CHANCES ACROSS THE NORTHERN AND
WESTERN PIEDMONT. ISENTROPIC ANALYSIS DEPICTS THE PATTERN WELL WITH
A FAIRLY NARROW CORRIDOR OF LIFT/SATURATION THAT SLIDES MAINLY
ACROSS SOUTHERN AND EASTERN NC. PRECIPITATION CHANCES QUICKLY TAIL
OFF FROM WEST TO EAST ON MONDAY NIGHT. THE AIR MASS AHEAD OF THE
SYSTEM WILL HAVE MODIFIED AND THE PRECIPITATION WILL FALL AS RAIN.
GIVEN THE MODIFICATION OF THE AIR MASS AND THE LIGHT PRECIPITATION
CHANCES...DO NOT EXPECT A SIGNIFICANT CAD EVENT TO OCCUR. HIGHS
MONDAY WILL RANGE IN THE 49-56 RANGE WITH MAX TEMPERATURES DEPENDENT
ON THE LOCATION AND INTENSITY OF THE PRECIPITATION.
AFTER THE UPPER TROUGH AXIS MOVES OFFSHORE...THE FLOW ALOFT BECOMES
MORE NORTHWESTERLY. ANOTHER DISTURBANCE IN THE FLOW AND SOME
RESIDUAL MOISTURE SHOULD BE SUFFICIENT TO PRODUCE SOME CLOUDINESS ON
TUESDAY BUT OTHERWISE FAIR CONDITIONS ARE EXPECTED WITH HIGHS IN THE
LOWER TO MID 50S.
THE FLOW FLATTENS ON TUESDAY NIGHT AND HEIGHTS RISE ON WEDNESDAY
INTO THURSDAY WITH INCREASING HIGH CLOUDS LATE WEDNESDAY AND A FAIR
AMOUNT OF CLOUDS EXPECTED ON THURSDAY. EXPECT DRY WEATHER THROUGH AT
LEAST THURSDAY AFTERNOON AS THE RIDGE AXIS BUILDS OVERHEAD.
MODERATING TEMPERATURES ARE EXPECTED ON THURSDAY INTO FRIDAY WITH
HIGHS IN THE MID TO UPPER 50S ON WEDNESDAY WARMING INTO THE UPPER
50S TO LOWER 60S ON THURSDAY WITH MORNING LOWS IN THE MID 30S TO
AROUND 40.
A LONGWAVE TROUGH DEVELOPS OVER THE WESTERN U.S. LATE THURSDAY INTO
FRIDAY AS AN ARCTIC AIRMASS DROPS INTO THE NORTHERN ROCKIES AND
NORTHERN PLAINS. AN INCREASINGLY MOIST SOUTHERLY TO SOUTHWESTERLY
FLOW DEVELOPS ACROSS THE CENTRAL U.S. AS THE TROUGH PUSHES EAST ON
FRIDAY. THE ASSOCIATED COLD FRONT REACHES THE WESTERN APPALACHIANS
ON FRIDAY MORNING. THERE ARE TIMING DIFFERENCES AMONG THE GUIDANCE
REGARDING THE EASTWARD ADVANCEMENT OF THE FRONT AND THE ASSOCIATED
PRECIPITATION WITH WPC PREFERRING A GEFS MEAN AND EC ENS MEAN.
REGARDLESS...THE THREAT OF RAIN WILL ARRIVE WITH LOW PROBABILITIES
IN THE WEST LATE THURSDAY NIGHT. POPS WILL INCREASE FROM WEST TO
EAST FRIDAY AND FRIDAY NIGHT WITH THE BEST CHANCE OF RAIN AT THIS
POINT APPEARING TO BE FRIDAY NIGHT AND SATURDAY. AHEAD OF THE FRONT
AND THE RAIN...TEMPERATURES ARE LIKELY TO CLIMB INTO THE 60S FRIDAY
AFTERNOON. -BLAES
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 AM SATURDAY...
VFR CONDITIONS CONTINUE THROUGH MUCH OF THE 12Z VALID TAF PERIOD.
WINDS REMAIN NOTICEABLE DURING THE EARLY MORNING IN THE TIGHTER
GRADIENT ON THE EAST SIDE OF THE RIDGE AXIS...AND THE KRAX WSR-88D
SHOWED WINDS OF 40KT EARLIER JUST ABOVE 2K FEET...BUT THESE WINDS
HAVE SINCE DIMINISHED ALMOST IN HALF SINCE 06Z. MODEL GUIDANCE SHOWS
SUCH WINDS CONTINUING TO DECREASE SOME DURING THE MORNING...BUT
THESE COULD TRANSLATE TO A FEW WIND GUSTS IN THE TEENS KTS AFTER
SUNRISE WITH EVEN MINIMAL MIXING AT KRDU AND ESPECIALLY KFAY AND
KRWI. AS HIGH PRESSURE SETTLES OVERHEAD FOR THIS EVENING...WINDS
SHOULD BECOME LIGHT. AS LOW-LEVEL MOISTURE INCREASES THIS EVENING
AND OVERNIGHT...THERE IS THE POTENTIAL FOR AT LEAST A PERIOD OF MVFR
CEILINGS PARTICULARLY TOWARD KFAY WITH A LESSER LIKELIHOOD TOWARD
KRDU AND KRWI.
BEYOND THE 12Z VALID TAF PERIOD...SUB-VFR CONDITIONS ARE POSSIBLE
EARLY SUNDAY MAINLY TOWARD KFAY...AND SUCH CONDITIONS ARE QUITE
POSSIBLE SUNDAY NIGHT MAINLY EAST AND SOUTHEAST OF THE TRIAD AS
MOISTURE INCREASES...ALONG WITH A CHANCE OF RAIN MAINLY EAST AND
SOUTHEAST OF THE TRIAD. THE PROBABILITY OF SUB-VFR CONDITIONS
INCREASES LATE SUNDAY NIGHT INTO MONDAY...AGAIN BEST EAST AND
SOUTHEAST OF THE TRIAD...WITH IMPROVING CONDITIONS FOR TUESDAY
CONTINUING INTO WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/DJF
SHORT TERM...DJF
LONG TERM...BLAES
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
958 AM EST SAT NOV 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND SOUTHWEST INTO THE REGION THROUGH
TONIGHT...THEN WEAKEN ON SUNDAY. A LOW PRESSURE SYSTEM IS EXPECTED
TO DEVELOP ALONG THE CAROLINA COAST ON MONDAY AS AN UPPER LEVEL
DISTURBANCE APPROACHES FROM THE WEST.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 650 AM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE AXIS OF SURFACE HIGH PRESSURE
NORTHEAST TO SOUTHWEST ACROSS CENTRAL NORTH CAROLINA...AND DURING
THE DAY THE RIDGE SETTLES SLOWLY SOUTH WHICH SHOULD RELAX THE
GRADIENT FOR THE LATE DAY AND OVERNIGHT. A MODERATE MID-LEVEL
SHORTWAVE WAS OBSERVED ON WATER VAPOR IMAGERY MOVING EAST FROM
MISSOURI AND ILLINOIS TOWARD THE MID-ATLANTIC...WITH A MID-LEVEL
TROUGH PASSING EAST OF THE STATE AS OF THIS WRITING. 1000-850MB
THICKNESSES ARE FORECAST VERY SIMILAR TO THOSE THAT OCCURRED
FRIDAY...WHEN HIGHS WERE AROUND 50 TO THE MID 50S. HOWEVER...
GUIDANCE IS VERY CONSISTENT IN SHOWING HIGHS TODAY ROUGHLY A
CATEGORY...POSSIBLY EVEN TWO...COOLER. NAM AND GFS BUFR SOUNDINGS
MAINTAIN STRONG SUBSIDENCE AND LIMITED MIXING POTENTIAL...AND AHEAD
OF THE MODEST MID-LEVEL SHORTWAVE TO OUR WEST THAT BOTH THE NAM AND
THE GFS MOVE ACROSS CENTRAL NORTH CAROLINA LATE THIS AFTERNOON AND
OVERNIGHT...DIFFLUENCE ALOFT INCREASES AS A 90KT 300MB JET
APPROACHES FROM THE WEST...WITH POSSIBLY JUST ENOUGH HIGH CLOUDS TO
TEMPER HIGHS SOMEWHAT. WILL LEAN TOWARD WARMER GUIDANCE FOR HIGHS IN
THE MID 40S TO LOWER 50S. ESPECIALLY ALONG AND EAST OF U.S. 1 THERE
SHOULD BE JUST A FEW WIND GUSTS IN THE TEENS KNOTS WITH MIXING LATER
THIS MORNING BEFORE THE SURFACE RIDGING SETTLES SOUTH. 925MB WINDS
ARE FORECAST ONLY TO AROUND 15KT DURING THE DAY.
THE LATEST RAP...ALONG WITH THE HRRR WRF...FORECAST AN INCREASE IN
LOW-LEVEL MOISTURE FROM THE SOUTHEAST LATE IN THE DAY. THIS MAY BE
REASONABLE...AS THE SATELLITE FOG PRODUCT SHOWED AREAS OF LOW CLOUDS
JUST OFFSHORE FROM SOUTHEAST NORTH CAROLINA EARLY THIS MORNING. HAVE
ADDED SOME CLOUD COVER TO THE GRIDDED AND WORDED FORECASTS
PARTICULARLY TOWARD KCTZ DURING THE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 650 AM SATURDAY...
SURFACE HIGH PRESSURE SHOULD BE DIRECTLY OVERHEAD OVERNIGHT KEEPING
THE GRADIENT VERY RELAXED. THE POTENTIAL FOR A QUITE CHILLY NIGHT
WOULD EXIST BUT THE COMBINATION OF SOME HIGH CLOUDS AND THE GFS
FORECAST OF INCREASING 850MB MOISTURE FROM THE SOUTH AND SOUTHWEST
MAY ACT TO KEEP TEMPERATURES CLOSE TO THE GUIDANCE LOWS OVERNIGHT.
THE LATEST SATELLITE FOG PRODUCT SHOWS LOW-LEVEL MOISTURE MOVING
WEST TOWARD THE SOUTH CAROLINA COAST...AND LOW-LEVEL ISENTROPIC
FORECASTS ALONG WITH THE INCREASING 850MB MOISTURE SUPPORT AN
INCREASE IN CLOUD COVER TO PARTLY-TO-MOSTLY CLOUDY PARTICULARLY
ALONG AND SOUTH OF ABOUT INTERSTATE 85 DURING THE OVERNIGHT HOURS.
THE TIMING OF THIS IS...OF COURSE...CRITICAL TO THE OVERNIGHT
TEMPERATURE FORECAST...BUT FOR THIS FORECAST WILL LEAN TOWARD THE
COOLER MOS GUIDANCE IN THE TRIAD AND THE WARMER MOS GUIDANCE
ELSEWHERE.
K INDICES SLOWLY RISE SUNDAY...WITH PRECIPITABLE WATER VALUES RISING
LATE SUNDAY TO BETWEEN 0.75 AND ONE INCH...ABOVE NORMAL FOR VERY
EARLY DECEMBER AT ABOUT THE 75TH PERCENTILE. LIFT STARTS TO INCREASE
LATE SUNDAY AND PARTICULARLY SUNDAY NIGHT AS ISENTROPIC LIFT ON THE
300K SURFACE INCREASES...WITH THE BEST POTENTIAL VORTICITY ON THE
1.5PVU SURFACE FORECAST BY THE GFS ALONG AND SOUTH OF ABOUT U.S. 64
LATE SUNDAY THROUGH SUNDAY NIGHT. SURFACE DEPICTIONS OF THE NAM AND
GFS DIFFER AND ARE FAIRLY CONSISTENT WITH THEMSELVES OVER THE LAST
TWO OR THREE RUNS...WITH THE NAM SHOWING A WEAK SURFACE LOW JUST OFF
THE SOUTH CAROLINA COAST SUNDAY NIGHT WHILE THE GFS FORECASTS MORE
OF AN INVERTED TROUGH BEFORE SURFACE LOW PRESSURE STRENGTHENS
OFFSHORE. REGARDLESS...QPF AND MOS GUIDANCE POPS ARE SIMILAR...
KEEPING MOST CHANCES FOR PRECIPITATION AT BAY SUNDAY AND INCREASING
CHANCES OVER MOST OF CENTRAL NORTH CAROLINA SUNDAY NIGHT. WILL NOTE
A SLIGHT CHANCE OF RAIN MAINLY OVER THE SANDHILLS AND SOUTHERN
COASTAL PLAIN SUNDAY WHERE THE BEST LOW-LEVEL MOISTURE SHOULD RESIDE
AS POTENTIAL VORTICITY INCREASES...WITH A CHANCE OF RAIN SUNDAY
NIGHT MAINLY ALONG AND EAST OF A LINE FROM ABOUT KIXA TO KAFP WITH A
SLIGHT CHANCE NORTH OF THAT LINE. DEBATED WHETHER OR NOT TO INCLUDE
A SLIGHT CHANCE IN THE TRIAD AND FOR THIS FORECAST WILL SHOW A VERY
LOW SLIGHT CHANCE THERE OVERNIGHT SUNDAY...THOUGH THIS COULD END UP
BEING OVERDONE WITH SUFFICIENT MOISTURE AND LIFT REMAINING JUST
EAST. SURFACE WET BULB TEMPERATURES AND PARTIAL THICKNESSES SUPPORT
ALL LIQUID.
ONCE AGAIN 1000-850MB THICKNESSES WOULD SUPPORT HIGHS SUNDAY ABOVE
MOS GUIDANCE...BUT GIVEN THE EXPECTED CLOUD COVER...WILL FORECAST
HIGHS AS A BLEND OF MAV AND MET MOS GUIDANCE FOR A FAIRLY UNIFORM
LOWER 50S IN MOST LOCATIONS. OVERNIGHT SUNDAY...IF IT REMAINS DRY IN
THE TRIAD LOWS SHOULD BE NEAR THE WARMER GUIDANCE...WHILE WHERE IT
RAINS TEMPERATURES WOULD APPROACH THE DEW POINT. THIS COINCIDES WITH
A BLEND OF MOS GUIDANCE...ALTHOUGH HIGHER THAN GUIDANCE TOWARD
KRWI...FOR LOWS IN THE MID TO UPPER 30S NORTHWEST...TO MID 40S
TOWARD KCTZ.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 235 AM SATURDAY...
ON MONDAY A LOW AMPLITUDE NORTHERN STREAM SHORTWAVE DROPS INTO THE
THE DEEP SOUTH AS A SHEARING SOUTHERN STREAM SYSTEM WITH A 250MB JET
OF 140 KTS PHASE TOGETHER BEFORE THE TROUGH AXIS MOVES OFF THE
SOUTHEAST COAST MONDAY NIGHT. THE TROUGH BECOMES NEGATIVELY TILTED
AND INITIATES SURFACE CYCLOGENESIS MONDAY NIGHT AND TUESDAY. RECENT
NWP TRENDS HAVE SUGGESTED A LESS AMPLIFIED SYSTEM WHILE PRODUCING A
BIT MORE QPF ACROSS MAINLY SOUTHEASTERN NC. IT REMAINS DIFFICULT AND
CONFIDENCE IS LOW REGARDING HOW FAR NORTH AND WEST PRECIPITATION
WILL SPREAD ACROSS CENTRAL NC BUT CONFIDENCE IS GROWING THAT SOME
LIGHT PRECIPITATION WILL FALL ACROSS THE SOUTHERN COASTAL PLAIN AND
SANDHILLS REGION. NWP CONSENSUS SHOWS THE DEEPEST MOISTURE AND
STRONGEST FORCING WILL BE CONFINED TO SOUTHEASTERN PORTIONS OF THE
RAH CWA WITH RAPIDLY DECREASING RAIN CHANCES ACROSS THE NORTHERN AND
WESTERN PIEDMONT. ISENTROPIC ANALYSIS DEPICTS THE PATTERN WELL WITH
A FAIRLY NARROW CORRIDOR OF LIFT/SATURATION THAT SLIDES MAINLY
ACROSS SOUTHERN AND EASTERN NC. PRECIPITATION CHANCES QUICKLY TAIL
OFF FROM WEST TO EAST ON MONDAY NIGHT. THE AIR MASS AHEAD OF THE
SYSTEM WILL HAVE MODIFIED AND THE PRECIPITATION WILL FALL AS RAIN.
GIVEN THE MODIFICATION OF THE AIR MASS AND THE LIGHT PRECIPITATION
CHANCES...DO NOT EXPECT A SIGNIFICANT CAD EVENT TO OCCUR. HIGHS
MONDAY WILL RANGE IN THE 49-56 RANGE WITH MAX TEMPERATURES DEPENDENT
ON THE LOCATION AND INTENSITY OF THE PRECIPITATION.
AFTER THE UPPER TROUGH AXIS MOVES OFFSHORE...THE FLOW ALOFT BECOMES
MORE NORTHWESTERLY. ANOTHER DISTURBANCE IN THE FLOW AND SOME
RESIDUAL MOISTURE SHOULD BE SUFFICIENT TO PRODUCE SOME CLOUDINESS ON
TUESDAY BUT OTHERWISE FAIR CONDITIONS ARE EXPECTED WITH HIGHS IN THE
LOWER TO MID 50S.
THE FLOW FLATTENS ON TUESDAY NIGHT AND HEIGHTS RISE ON WEDNESDAY
INTO THURSDAY WITH INCREASING HIGH CLOUDS LATE WEDNESDAY AND A FAIR
AMOUNT OF CLOUDS EXPECTED ON THURSDAY. EXPECT DRY WEATHER THROUGH AT
LEAST THURSDAY AFTERNOON AS THE RIDGE AXIS BUILDS OVERHEAD.
MODERATING TEMPERATURES ARE EXPECTED ON THURSDAY INTO FRIDAY WITH
HIGHS IN THE MID TO UPPER 50S ON WEDNESDAY WARMING INTO THE UPPER
50S TO LOWER 60S ON THURSDAY WITH MORNING LOWS IN THE MID 30S TO
AROUND 40.
A LONGWAVE TROUGH DEVELOPS OVER THE WESTERN U.S. LATE THURSDAY INTO
FRIDAY AS AN ARCTIC AIRMASS DROPS INTO THE NORTHERN ROCKIES AND
NORTHERN PLAINS. AN INCREASINGLY MOIST SOUTHERLY TO SOUTHWESTERLY
FLOW DEVELOPS ACROSS THE CENTRAL U.S. AS THE TROUGH PUSHES EAST ON
FRIDAY. THE ASSOCIATED COLD FRONT REACHES THE WESTERN APPALACHIANS
ON FRIDAY MORNING. THERE ARE TIMING DIFFERENCES AMONG THE GUIDANCE
REGARDING THE EASTWARD ADVANCEMENT OF THE FRONT AND THE ASSOCIATED
PRECIPITATION WITH WPC PREFERRING A GEFS MEAN AND EC ENS MEAN.
REGARDLESS...THE THREAT OF RAIN WILL ARRIVE WITH LOW PROBABILITIES
IN THE WEST LATE THURSDAY NIGHT. POPS WILL INCREASE FROM WEST TO
EAST FRIDAY AND FRIDAY NIGHT WITH THE BEST CHANCE OF RAIN AT THIS
POINT APPEARING TO BE FRIDAY NIGHT AND SATURDAY. AHEAD OF THE FRONT
AND THE RAIN...TEMPERATURES ARE LIKELY TO CLIMB INTO THE 60S FRIDAY
AFTERNOON. -BLAES
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 AM SATURDAY...
VFR CONDITIONS CONTINUE THROUGH MUCH OF THE 12Z VALID TAF PERIOD.
WINDS REMAIN NOTICEABLE DURING THE EARLY MORNING IN THE TIGHTER
GRADIENT ON THE EAST SIDE OF THE RIDGE AXIS...AND THE KRAX WSR-88D
SHOWED WINDS OF 40KT EARLIER JUST ABOVE 2K FEET...BUT THESE WINDS
HAVE SINCE DIMINISHED ALMOST IN HALF SINCE 06Z. MODEL GUIDANCE SHOWS
SUCH WINDS CONTINUING TO DECREASE SOME DURING THE MORNING...BUT
THESE COULD TRANSLATE TO A FEW WIND GUSTS IN THE TEENS KTS AFTER
SUNRISE WITH EVEN MINIMAL MIXING AT KRDU AND ESPECIALLY KFAY AND
KRWI. AS HIGH PRESSURE SETTLES OVERHEAD FOR THIS EVENING...WINDS
SHOULD BECOME LIGHT. AS LOW-LEVEL MOISTURE INCREASES THIS EVENING
AND OVERNIGHT...THERE IS THE POTENTIAL FOR AT LEAST A PERIOD OF MVFR
CEILINGS PARTICULARLY TOWARD KFAY WITH A LESSER LIKELIHOOD TOWARD
KRDU AND KRWI.
BEYOND THE 12Z VALID TAF PERIOD...SUB-VFR CONDITIONS ARE POSSIBLE
EARLY SUNDAY MAINLY TOWARD KFAY...AND SUCH CONDITIONS ARE QUITE
POSSIBLE SUNDAY NIGHT MAINLY EAST AND SOUTHEAST OF THE TRIAD AS
MOISTURE INCREASES...ALONG WITH A CHANCE OF RAIN MAINLY EAST AND
SOUTHEAST OF THE TRIAD. THE PROBABILITY OF SUB-VFR CONDITIONS
INCREASES LATE SUNDAY NIGHT INTO MONDAY...AGAIN BEST EAST AND
SOUTHEAST OF THE TRIAD...WITH IMPROVING CONDITIONS FOR TUESDAY
CONTINUING INTO WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...BLAES
AVIATION...DJF
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 650 AM
EST SAT NOV 30 2013
.SYNOPSIS...
SURFACE HIGH PRESSURE REMAINS IN PLACE THROUGH THE DAY SUNDAY.
MOISTURE INCREASES AHEAD OF LOW PRESSURE THAT GRADUALLY STRENGTHENS
JUST OFF THE CAROLINA COAST LATE SUNDAY NIGHT THROUGH TUESDAY. HIGH
PRESSURE RETURNS FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 650 AM SATURDAY...
THE LATEST SURFACE ANALYSIS SHOWED THE AXIS OF SURFACE HIGH PRESSURE
NORTHEAST TO SOUTHWEST ACROSS CENTRAL NORTH CAROLINA...AND DURING
THE DAY THE RIDGE SETTLES SLOWLY SOUTH WHICH SHOULD RELAX THE
GRADIENT FOR THE LATE DAY AND OVERNIGHT. A MODERATE MID-LEVEL
SHORTWAVE WAS OBSERVED ON WATER VAPOR IMAGERY MOVING EAST FROM
MISSOURI AND ILLINOIS TOWARD THE MID-ATLANTIC...WITH A MID-LEVEL
TROUGH PASSING EAST OF THE STATE AS OF THIS WRITING. 1000-850MB
THICKNESSES ARE FORECAST VERY SIMILAR TO THOSE THAT OCCURRED
FRIDAY...WHEN HIGHS WERE AROUND 50 TO THE MID 50S. HOWEVER...
GUIDANCE IS VERY CONSISTENT IN SHOWING HIGHS TODAY ROUGHLY A
CATEGORY...POSSIBLY EVEN TWO...COOLER. NAM AND GFS BUFR SOUNDINGS
MAINTAIN STRONG SUBSIDENCE AND LIMITED MIXING POTENTIAL...AND AHEAD
OF THE MODEST MID-LEVEL SHORTWAVE TO OUR WEST THAT BOTH THE NAM AND
THE GFS MOVE ACROSS CENTRAL NORTH CAROLINA LATE THIS AFTERNOON AND
OVERNIGHT...DIFFLUENCE ALOFT INCREASES AS A 90KT 300MB JET
APPROACHES FROM THE WEST...WITH POSSIBLY JUST ENOUGH HIGH CLOUDS TO
TEMPER HIGHS SOMEWHAT. WILL LEAN TOWARD WARMER GUIDANCE FOR HIGHS IN
THE MID 40S TO LOWER 50S. ESPECIALLY ALONG AND EAST OF U.S. 1 THERE
SHOULD BE JUST A FEW WIND GUSTS IN THE TEENS KNOTS WITH MIXING LATER
THIS MORNING BEFORE THE SURFACE RIDGING SETTLES SOUTH. 925MB WINDS
ARE FORECAST ONLY TO AROUND 15KT DURING THE DAY.
THE LATEST RAP...ALONG WITH THE HRRR WRF...FORECAST AN INCREASE IN
LOW-LEVEL MOISTURE FROM THE SOUTHEAST LATE IN THE DAY. THIS MAY BE
REASONABLE...AS THE SATELLITE FOG PRODUCT SHOWED AREAS OF LOW CLOUDS
JUST OFFSHORE FROM SOUTHEAST NORTH CAROLINA EARLY THIS MORNING. HAVE
ADDED SOME CLOUD COVER TO THE GRIDDED AND WORDED FORECASTS
PARTICULARLY TOWARD KCTZ DURING THE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 650 AM SATURDAY...
SURFACE HIGH PRESSURE SHOULD BE DIRECTLY OVERHEAD OVERNIGHT KEEPING
THE GRADIENT VERY RELAXED. THE POTENTIAL FOR A QUITE CHILLY NIGHT
WOULD EXIST BUT THE COMBINATION OF SOME HIGH CLOUDS AND THE GFS
FORECAST OF INCREASING 850MB MOISTURE FROM THE SOUTH AND SOUTHWEST
MAY ACT TO KEEP TEMPERATURES CLOSE TO THE GUIDANCE LOWS OVERNIGHT.
THE LATEST SATELLITE FOG PRODUCT SHOWS LOW-LEVEL MOISTURE MOVING
WEST TOWARD THE SOUTH CAROLINA COAST...AND LOW-LEVEL ISENTROPIC
FORECASTS ALONG WITH THE INCREASING 850MB MOISTURE SUPPORT AN
INCREASE IN CLOUD COVER TO PARTLY-TO-MOSTLY CLOUDY PARTICULARLY
ALONG AND SOUTH OF ABOUT INTERSTATE 85 DURING THE OVERNIGHT HOURS.
THE TIMING OF THIS IS...OF COURSE...CRITICAL TO THE OVERNIGHT
TEMPERATURE FORECAST...BUT FOR THIS FORECAST WILL LEAN TOWARD THE
COOLER MOS GUIDANCE IN THE TRIAD AND THE WARMER MOS GUIDANCE
ELSEWHERE.
K INDICES SLOWLY RISE SUNDAY...WITH PRECIPITABLE WATER VALUES RISING
LATE SUNDAY TO BETWEEN 0.75 AND ONE INCH...ABOVE NORMAL FOR VERY
EARLY DECEMBER AT ABOUT THE 75TH PERCENTILE. LIFT STARTS TO INCREASE
LATE SUNDAY AND PARTICULARLY SUNDAY NIGHT AS ISENTROPIC LIFT ON THE
300K SURFACE INCREASES...WITH THE BEST POTENTIAL VORTICITY ON THE
1.5PVU SURFACE FORECAST BY THE GFS ALONG AND SOUTH OF ABOUT U.S. 64
LATE SUNDAY THROUGH SUNDAY NIGHT. SURFACE DEPICTIONS OF THE NAM AND
GFS DIFFER AND ARE FAIRLY CONSISTENT WITH THEMSELVES OVER THE LAST
TWO OR THREE RUNS...WITH THE NAM SHOWING A WEAK SURFACE LOW JUST OFF
THE SOUTH CAROLINA COAST SUNDAY NIGHT WHILE THE GFS FORECASTS MORE
OF AN INVERTED TROUGH BEFORE SURFACE LOW PRESSURE STRENGTHENS
OFFSHORE. REGARDNESS...QPF AND MOS GUIDANCE POPS ARE SIMILAR...
KEEPING MOST CHANCES FOR PRECIPITATION AT BAY SUNDAY AND INCREASING
CHANCES OVER MOST OF CENTRAL NORTH CAROLINA SUNDAY NIGHT. WILL NOTE
A SLIGHT CHANCE OF RAIN MAINLY OVER THE SANDHILLS AND SOUTHERN
COASTAL PLAIN SUNDAY WHERE THE BEST LOW-LEVEL MOISTURE SHOULD RESIDE
AS POTENTIAL VORTICITY INCREASES...WITH A CHANCE OF RAIN SUNDAY
NIGHT MAINLY ALONG AND EAST OF A LINE FROM ABOUT KIXA TO KAFP WITH A
SLIGHT CHANCE NORTH OF THAT LINE. DEBATED WHETHER OR NOT TO INCLUDE
A SLIGHT CHANCE IN THE TRIAD AND FOR THIS FORECAST WILL SHOW A VERY
LOW SLIGHT CHANCE THERE OVERNIGHT SUNDAY...THOUGH THIS COULD END UP
BEING OVERDONE WITH SUFFICIENT MOISTURE AND LIFT REMAINING JUST
EAST. SURFACE WET BULB TEMPERATURES AND PARTIAL THICKNESSES SUPPORT
ALL LIQUID.
ONCE AGAIN 1000-850MB THICKNESSES WOULD SUPPORT HIGHS SUNDAY ABOVE
MOS GUIDANCE...BUT GIVEN THE EXPECTED CLOUD COVER...WILL FORECAST
HIGHS AS A BLEND OF MAV AND MET MOS GUIDANCE FOR A FAIRLY UNIFORM
LOWER 50S IN MOST LOCATIONS. OVERNIGHT SUNDAY...IF IT REMAINS DRY IN
THE TRIAD LOWS SHOULD BE NEAR THE WARMER GUIDANCE...WHILE WHERE IT
RAINS TEMPERATURES WOULD APPROACH THE DEW POINT. THIS COINCIDES WITH
A BLEND OF MOS GUIDANCE...ALTHOUGH HIGHER THAN GUIDANCE TOWARD
KRWI...FOR LOWS IN THE MID TO UPPER 30S NORTHWEST...TO MID 40S
TOWARD KCTZ.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 235 AM SATURDAY...
ON MONDAY A LOW AMPLITUDE NORTHERN STREAM SHORTWAVE DROPS INTO THE
THE DEEP SOUTH AS A SHEARING SOUTHERN STREAM SYSTEM WITH A 250MB JET
OF 140 KTS PHASE TOGETHER BEFORE THE TROUGH AXIS MOVES OFF THE
SOUTHEAST COAST MONDAY NIGHT. THE TROUGH BECOMES NEGATIVELY TILTED
AND INITIATES SURFACE CYCLOGENESIS MONDAY NIGHT AND TUESDAY. RECENT
NWP TRENDS HAVE SUGGESTED A LESS AMPLIFIED SYSTEM WHILE PRODUCING A
BIT MORE QPF ACROSS MAINLY SOUTHEASTERN NC. IT REMAINS DIFFICULT AND
CONFIDENCE IS LOW REGARDING HOW FAR NORTH AND WEST PRECIPITATION
WILL SPREAD ACROSS CENTRAL NC BUT CONFIDENCE IS GROWING THAT SOME
LIGHT PRECIPITATION WILL FALL ACROSS THE SOUTHERN COASTAL PLAIN AND
SANDHILLS REGION. NWP CONSENSUS SHOWS THE DEEPEST MOISTURE AND
STRONGEST FORCING WILL BE CONFINED TO SOUTHEASTERN PORTIONS OF THE
RAH CWA WITH RAPIDLY DECREASING RAIN CHANCES ACROSS THE NORTHERN AND
WESTERN PIEDMONT. ISENTROPIC ANALYSIS DEPICTS THE PATTERN WELL WITH
A FAIRLY NARROW CORRIDOR OF LIFT/SATURATION THAT SLIDES MAINLY
ACROSS SOUTHERN AND EASTERN NC. PRECIPITATION CHANCES QUICKLY TAIL
OFF FROM WEST TO EAST ON MONDAY NIGHT. THE AIR MASS AHEAD OF THE
SYSTEM WILL HAVE MODIFIED AND THE PRECIPITATION WILL FALL AS RAIN.
GIVEN THE MODIFICATION OF THE AIR MASS AND THE LIGHT PRECIPITATION
CHANCES...DO NOT EXPECT A SIGNIFICANT CAD EVENT TO OCCUR. HIGHS
MONDAY WILL RANGE IN THE 49-56 RANGE WITH MAX TEMPERATURES DEPENDENT
ON THE LOCATION AND INTENSITY OF THE PRECIPITATION.
AFTER THE UPPER TROUGH AXIS MOVES OFFSHORE...THE FLOW ALOFT BECOMES
MORE NORTHWESTERLY. ANOTHER DISTURBANCE IN THE FLOW AND SOME
RESIDUAL MOISTURE SHOULD BE SUFFICIENT TO PRODUCE SOME CLOUDINESS ON
TUESDAY BUT OTHERWISE FAIR CONDITIONS ARE EXPECTED WITH HIGHS IN THE
LOWER TO MID 50S.
THE FLOW FLATTENS ON TUESDAY NIGHT AND HEIGHTS RISE ON WEDNESDAY
INTO THURSDAY WITH INCREASING HIGH CLOUDS LATE WEDNESDAY AND A FAIR
AMOUNT OF CLOUDS EXPECTED ON THURSDAY. EXPECT DRY WEATHER THROUGH AT
LEAST THURSDAY AFTERNOON AS THE RIDGE AXIS BUILDS OVERHEAD.
MODERATING TEMPERATURES ARE EXPECTED ON THURSDAY INTO FRIDAY WITH
HIGHS IN THE MID TO UPPER 50S ON WEDNESDAY WARMING INTO THE UPPER
50S TO LOWER 60S ON THURSDAY WITH MORNING LOWS IN THE MID 30S TO
AROUND 40.
A LONGWAVE TROUGH DEVELOPS OVER THE WESTERN U.S. LATE THURSDAY INTO
FRIDAY AS AN ARCTIC AIRMASS DROPS INTO THE NORTHERN ROCKIES AND
NORTHERN PLAINS. AN INCREASINGLY MOIST SOUTHERLY TO SOUTHWESTERLY
FLOW DEVELOPS ACROSS THE CENTRAL U.S. AS THE TROUGH PUSHES EAST ON
FRIDAY. THE ASSOCIATED COLD FRONT REACHES THE WESTERN APPALACHIANS
ON FRIDAY MORNING. THERE ARE TIMING DIFFERENCES AMONG THE GUIDANCE
REGARDING THE EASTWARD ADVANCEMENT OF THE FRONT AND THE ASSOCIATED
PRECIPITATION WITH WPC PREFERRING A GEFS MEAN AND EC ENS MEAN.
REGARDLESS...THE THREAT OF RAIN WILL ARRIVE WITH LOW PROBABILITIES
IN THE WEST LATE THURSDAY NIGHT. POPS WILL INCREASE FROM WEST TO
EAST FRIDAY AND FRIDAY NIGHT WITH THE BEST CHANCE OF RAIN AT THIS
POINT APPEARING TO BE FRIDAY NIGHT AND SATURDAY. AHEAD OF THE FRONT
AND THE RAIN...TEMPERATURES ARE LIKELY TO CLIMB INTO THE 60S FRIDAY
AFTERNOON. -BLAES
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 AM SATURDAY...
VFR CONDITIONS CONTINUE THROUGH MUCH OF THE 12Z VALID TAF PERIOD.
WINDS REMAIN NOTICEABLE DURING THE EARLY MORNING IN THE TIGHTER
GRADIENT ON THE EAST SIDE OF THE RIDGE AXIS...AND THE KRAX WSR-88D
SHOWED WINDS OF 40KT EARLIER JUST ABOVE 2K FEET...BUT THESE WINDS
HAVE SINCE DIMINISHED ALMOST IN HALF SINCE 06Z. MODEL GUIDANCE SHOWS
SUCH WINDS CONTINUING TO DECREASE SOME DURING THE MORNING...BUT
THESE COULD TRANSLATE TO A FEW WIND GUSTS IN THE TEENS KTS AFTER
SUNRISE WITH EVEN MINIMAL MIXING AT KRDU AND ESPECIALLY KFAY AND
KRWI. AS HIGH PRESSURE SETTLES OVERHEAD FOR THIS EVENING...WINDS
SHOULD BECOME LIGHT. AS LOW-LEVEL MOISTURE INCREASES THIS EVENING
AND OVERNIGHT...THERE IS THE POTENTIAL FOR AT LEAST A PERIOD OF MVFR
CEILINGS PARTICULARLY TOWARD KFAY WITH A LESSER LIKELIHOOD TOWARD
KRDU AND KRWI.
BEYOND THE 12Z VALID TAF PERIOD...SUB-VFR CONDITIONS ARE POSSIBLE
EARLY SUNDAY MAINLY TOWARD KFAY...AND SUCH CONDITIONS ARE QUITE
POSSIBLE SUNDAY NIGHT MAINLY EAST AND SOUTHEAST OF THE TRIAD AS
MOISTURE INCREASES...ALONG WITH A CHANCE OF RAIN MAINLY EAST AND
SOUTHEAST OF THE TRIAD. THE PROBABILITY OF SUB-VFR CONDITIONS
INCREASES LATE SUNDAY NIGHT INTO MONDAY...AGAIN BEST EAST AND
SOUTHEAST OF THE TRIAD...WITH IMPROVING CONDITIONS FOR TUESDAY
CONTINUING INTO WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS... DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...BLAES
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
700 PM CST SUN DEC 1 2013
.UPDATE...
ISSUED AT 654 PM CST SUN DEC 1 2013
BANDS OF LIGHT SNOW SLOWLY MOVING EAST THRU THE RED RIVER VALLEY
WITH REGIONAL RADAR SHOWING A LARGE BREAK IN THE ACTION WEST OF
DVL/VCY....SO WILL UPDATE POPS TO REFLECT LIKELY BREAK IN ACTION
AND LOWER POPS IN MY FAR WEST AND SOUTHWEST. OTHERWISE STILL
RATHER UNCERTAIN IN HOW THIS BAND WILL MOVE THRU....HRRR MOVES IT
THROUGH BUT RUC KEEPS SOME LIGHT PRECIP AROUND ALL NIGHT AND THEN
MERGES IT WITH THE SNOW BAND THAT WILL COME IN AFTER 12Z MON.
OVERALL THOUGH AGREE WITH LIGHT ACCUMS TONIGHT UNDER AN
INCH....BUT RADAR RETURNS DO SHOW SOME BRIEF POCKETS OF MODERATE
SNOW. FORTUNATELY THE FREEZING RAIN RISK REMAINED JUST AT OUR CWA
DOORSTEP WITH NO FURTHER REPORTS OF ANY ICING COOPERSTOWN-VALLEY
CITY EASTWARD. SO WITH PRECIP EXITING JAMESTOWN AREA FEEL OK GOING
ALL SNOW.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 340 PM CST SUN DEC 1 2013
CHALLENGES ABOUND WITH UPCOMING WINTER STORM. MAIN CONCERNS ARE
SNOW AMOUNTS AND ASSOCIATED HEADLINES. GFS/NAM/ECMWF/GEM ARE NOW
IN BETTER AGREEMENT WITH THE TIMING OF THE LEAD SHORT-WAVE
EJECTING OUT OF THE PARENT TROUGH ON TUESDAY...BUT THE NCEP SUITE
CONTINUES TO BE STRONGER THAN THEIR INTERNATIONAL COUNTERPARTS WITH
THE NAM BEING THE MOST INTENSE AND A NORTHERN OUTLIER. WILL USE A
BLENDED SOLUTION OF THE GFS/ECMWF/GEM...BUT THE FINAL TRACK IS
STILL FAR FROM CERTAIN.
FOR TONIGHT...DISORGANIZED BAND OF LIGHT SNOW CURRENTLY STRETCHING
FROM ROLLA TO JAMESTOWN WILL CONTINUE TO DRIFT EASTWARD.
ACCUMULATIONS WILL BE LIGHT...GENERALLY LESS THAN AN INCH. WITH
OVERCAST SKIES AND NO CHANGE IN AIR MASS...LOWS WON/T DROP MUCH
FROM CURRENT OBSERVATIONS WITH TEMPERATURES BY 12 UTC MONDAY IN THE
MID TEENS TO MID 20S.
MOISTURE AND MID-LEVEL LIFT INCREASE ON MONDAY AND MONDAY NIGHT
WITH AREA OF WARM AIR ADVECTION OUT AHEAD OF THE PRIMARY
TROUGH. FRONTOGENESIS IS NOT TOO STRONG...BUT CONVERGENCE ALONG AND
NORTH OF THE 850 HPA LOW TRACK WILL RESULT IN A BAND OF LIGHT SNOW
ACROSS MUCH OF THE FORECAST AREA. WITH FORECAST QPF IN THE 0.2 TO
0.4 INCH RANGE AND AND SNOW RATIOS AROUND 12:1...EXPECT SNOW
AMOUNTS IN THE 3 TO 5 INCH RANGE ALONG AND NORTH OF A LINE FROM
VALLEY CITY TO FARGO TO WADENA. FOR THIS AREA...WILL ISSUE A
WINTER WEATHER ADVISORY FROM 12 UTC MONDAY UNTIL 12 UTC TUESDAY.
ACROSS SOUTHEAST ND INTO FAR WEST-CENTRAL MN...ECMWF AND SREF
SUGGEST THE POSSIBILITY OF FREEZING PRECIPITATION DUE TO A LACK OF
SATURATION ALOFT. CONFIDENCE IN THIS SCENARIO IS NOT HIGH...SO
WILL KEEP P-TYPE AS ALL SNOW FOR NOW WITH SNOW AMOUNTS OF 1-2
INCHES. ADVISORY MAY NEED TO BE EXPANDED IF FREEZING PRECIPITATION
MATERIALIZES. WINDS WILL BE LIGHT FROM THE EAST THROUGH THE DAY...
SO DO NOT ANTICIPATE BLOWING SNOW TO BE MUCH OF AN ISSUE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 PM CST SUN DEC 1 2013
ATTENTION THEN TURNS TO THE BIG SHOW ON TUESDAY AS THE SURFACE LOW
EJECTS FROM THE CENTRAL ROCKIES AND ACROSS THE UPPER MIDWEST.
PWATS INCREASE TO NEAR 0.5 INCHES AND WITH STRONG ISENTROPIC LIFT
ALONG WARM CONVEYOR BELT...COMBINED WITH DIFFLUENCE ALOFT...
PERIODS OF MODERATE TO HEAVY SNOW ARE EXPECTED TO DEVELOP AND MOVE
ACROSS THE FORECAST AREA THROUGH THE DAY. WITH QPF AMOUNTS GREATER
THAN 0.6 INCHES...SNOW AMOUNTS IN EXCESS OF 6 INCHES ARE A REAL
POSSIBILITY. WINDS ALSO INCREASE AND SHIFT TO THE NORTH TUESDAY
NIGHT...INCREASING THE POTENTIAL FOR BLOWING AND DRIFTING SNOW.
FOR HEADLINE PURPOSES...WILL TREAT TUESDAY/S SNOW SEPARATELY FROM
THAT WHICH FALLS ON MONDAY SINCE THERE WILL LIKELY BE A 6 TO 12
HOUR GAP WITH LITTLE TO NO SNOW FALLING BETWEEN THE TWO EVENTS.
WILL ISSUE A WINTER STORM WATCH FOR THE ENTIRE FORECAST AREA FROM
12 UTC TUESDAY THROUGH 00 UTC THURSDAY.
WEDNESDAY THROUGH SUNDAY...THE WINTER STORM SHOULD BE WRAPPING UP
WEDNESDAY NIGHT AS THE LEAD UPPER LOW MOVES OFF INTO ONTARIO. SNOW
WILL LINGER MAINLY OVER NORTHERN AND EASTERN COUNTIES...BUT WILL
BE STARTING TO TAPER OFF OVERNIGHT. CONTINUED TO KEEP LOW POPS IN
THE NORTHEAST THROUGH THE END OF THE WEEK AS WEAK REINFORCING
SHORTWAVES MOVES THROUGH. THE MAIN STORY FOR THE EXTENDED PERIOD
WILL BE THE EXTREME COLD. ARCTIC AIR WILL STAY IN PLACE THROUGH
THE WEEKEND WITH A GREATER THAN 1040MB HIGH OVER THE NORTHERN
PLAINS AND VERY LOW 1000-500MB THICKNESS VALUES. CONTINUED TO KEEP
HIGHS AROUND ZERO ON THURSDAY AND FALLING TO BELOW ZERO FOR FRIDAY
AND INTO THE WEEKEND. LOWS SHOULD BE DOWN AROUND THE 15 TO 20
BELOW RANGE AND SOME EVEN LOWER...NEAR RECORD VALUES NOT OUT OF
THE QUESTION. THERE IS STRONG CONSENSUS FOR COLD FOR MUCH OF THE
PERIOD...BUT THERE ARE SOME DIFFERENCES IN THE PATTERN BY SUNDAY.
THE ECMWF DIGS THE NEXT TROUGH MUCH FURTHER SOUTH AND
WEST...BRINGING A STORM SYSTEM CLOSE TO OUR SOUTHERN COUNTIES. THE
GFS IS DRIER AND A TAD WARMER WITH THE A REINFORCING SHORTWAVE NOT
DIGGING DOWN INTO THE NORTHERN PLAINS UNTIL NEXT MONDAY. ALLBLEND
PUTS SOME LOW POPS IN THE SOUTH AND EAST AT THE TAIL END OF THE
EXTENDED...AND THAT SEEMS REASONABLE AT THIS POINT DUE TO THE
UNCERTAINTY. TEMPS WILL CONTINUE TO BE ABOUT 20-30 DEGREES BELOW
SEASONABLE NORMALS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 654 PM CST SUN DEC 1 2013
TAF FCSTS TONIGHT QUITE CHALLENGING. HAD A CLEARING WEDGE IN THE
LOWER CLOUDS COME IN FROM THE EAST AND SOUTHEAST FROM PKD-BJI
AREAS WITH NOW VFR CIGS AT GFK-FAR....MEANWHILE HAVE IFR AND LOW
END MVFR CIGS SURROUNDING THIS AREA INCLUDING TVF-DVL OVERALL
SEEMS TO BE THE IDEA THAT THE LOW CLOUD CIGS WILL GRADUALLY BREAK
UP LEADING TO A MORE VFR CIG BEFORE SNOW ARRIVES IN EARNEST
MONDAY. BUT CONFIDENCE IN SKY CIG FCST IS NOT HIGH.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR NDZ006>008-014>016-024-026>030-038-039-049-
052>054.
WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO 6 AM CST TUESDAY FOR
NDZ006>008-014>016-024-026>030-038-039-054.
MN...WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR MNZ001>009-013>017-022>024-027>032-040.
WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO 6 AM CST TUESDAY FOR
MNZ001>009-013>017-022>024-027-028-031-032.
&&
$$
UPDATE...RIDDLE
SHORT TERM...ROGERS
LONG TERM...ROGERS/JR
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
253 PM CST SAT NOV 30 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 252 PM CST SAT NOV 30 2013
THE MAIN FORECAST CONCERNS IN THE SHORT TERM WILL BE PRECIPITATION
CHANCES LATE TONIGHT INTO SUNDAY. THERE IS GENERAL AGREEMENT AMONG
THE SHORT TERM MODELS THAT ANOTHER UPPER WAVE WILL MOVE ACROSS THE
NORTHERN PLAINS TONIGHT INTO SUNDAY AS AN H3 JET APPROACHES THE
REGION. THERE ARE SOME DIFFERENCES IN TIMING...BUT MOST SOLUTIONS
KEEP THE PRECIPITATION CHANCES WEST OF THE FORECAST AREA UNTIL LATE
TONIGHT. WILL SHOW INCREASING POPS IN THE WEST AFTER
MIDNIGHT...AND THEN SPREAD THE HIGHER POPS ACROSS WESTERN AND
CENTRAL NORTH DAKOTA ON SUNDAY.
PRECIPITATION TYPE WILL BE A CHALLENGE WITH THERMAL PROFILES
SUGGESTING MAINLY SNOW IN THE NORTH AND EAST...HOWEVER WARMER AIR
IS EXPECTED TO BE IN PLACE IN THE SOUTH AND WEST. HAVE GONE WITH A
MIX OF PRECIPITATION TYPES IN THE WEST CENTRAL AND SOUTHWEST LATE
TONIGHT AND SUNDAY. KEPT MOST SNOW AMOUNTS AN INCH OR LESS...AND
DID NOT CARRY ANY ICE ACCUMULATIONS DUE TO THE UNCERTAINTY STILL
SURROUNDING THE THERMAL PROFILES. LATER SHIFTS WILL HAVE TO KEEP
AN EYE ON HOW THINGS PROGRESS...BUT DO NOT HAVE ENOUGH CONFIDENCE
IN THE MIXED PRECIPITATION ACCUMULATING ENOUGH TONIGHT / SUNDAY TO
WARRANT THE ISSUANCE OF ANY ADVISORIES AT THE MOMENT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 252 PM CST SAT NOV 30 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS A POTENTIAL PROLONGED
SNOW EVENT MONDAY THROUGH WEDNESDAY...FOLLOWED BY VERY COLD ARCTIC
AIR.
THE 12 UTC DETERMINISTIC GUIDANCE IS IN GOOD AGREEMENT ON
SURFACE CYCLOGENESIS ACROSS SOUTHEAST ALBERTA AND INTO CENTRAL
MONTANA SUNDAY NIGHT INTO MONDAY. IN RESPONSE...A BAND OF
PREICPITATION IN LOW LEVEL ISENTROPIC LIFT IS FORECAST TO DEVELOP
ACROSS NORTHWEST AND INTO CENTRAL NORTH DAKOTA. PRECIPITATION IS
EXPECTED TO BE ALL SNOW ACROSS NORTHERN NORTH DAKOTA AND INTO THE
JAMES RIVER VALLEY. HOWEVER...A MIX OF FREEZING RAIN AND SLEET IS
POSSIBLE ON THE WESTERN PERIPHERY OF THE BAND...ESPECIALLY DURING
THE MORNING...WHERE A +1 TO +3 C MELTING LAYER ALOFT WILL BE IN
PLACE. A WINTER WEATHER ADVISORY MAY BE NEEDED FOR THIS EVENT AS
TWO TO FOUR INCHES OF SNOW ARE POSSIBLE ALONG AND NORTH OF US
HIGHWAY 2 AND INTO THE JAMES RIVER VALLEY...WITH POSSIBLE MINOR
ICE ACCUMULATIONS ACROSS THE SOUTH CENTRAL.
FOR THE MONDAY NIGHT THROUGH WEDNESDAY PORTION OF THE STORM...THE
12 UTC GFS/NAM AND 15 UTC SREF WERE DISCOUNTED AS THEY EJECT A
DEEP AND RAPIDLY PROPAGATING UPPER LEVEL LOW OUT OF THE MAIN
LONGWAVE. THIS IS MUCH DIFFERENT AND A SIGNIFICANT CHANGE FROM THE
PREFERRED 12 UTC ECMWF AND GEM SOLUTIONS. FOLLOWING THESE
SOLUTIONS...A PROLONGED PERIOD OF LIGHT TO MODERATE SNOW IS
EXPECTED FROM MONDAY NIGHT THROUGH WEDNESDAY ACROSS OF WESTERN AND
CENTRAL NORTH DAKOTA WITH A DEEP FETCH OF SOUTHWEST FLOW ALOFT.
HEAVY SNOWFALL ACCUMULATIONS ARE POSSIBLE...WITH BLOWING SNOW
BECOMING A THREAT WEDNESDAY ON THE BACKSIDE OF THE SURFACE LOW.
THEREAFTER...VERY COLD ARCTIC AIR TAKES OVER THE REGION INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 252 PM CST SAT NOV 30 2013
AFTERNOON VISIBLE SATELLITE IMAGERY SHOW STRATUS ACROSS PARTS OF
SOUTHERN CANADA MOVING SOUTH TOWARDS NORTHERN NORTH DAKOTA. THE
LATEST RAP MODEL SUGGESTS THE STRATUS COULD REACH KMOT AND BY LATE
AFTERNOON...AND THEN CONTINUE TO SPREAD SOUTH TONIGHT. LOWER
CLOUDS ARE ALSO POSSIBLE AS A CHANCE OF PRECIPITATION MOVES
TOWARDS THE REGION LATE TONIGHT INTO SUNDAY. OVERALL...WILL SHOW
A DOWNWARD TREND IN REGARDS TO CEILINGS...WITH VISIBILITY
RESTRICTIONS POSSIBLE AS PRECIPITATION CHANCES INCREASE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CK
LONG TERM...AYD
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1258 PM CST SAT NOV 30 2013
.UPDATE...
ISSUED AT 1258 PM CST SAT NOV 30 2013
WEAK RADAR RETURNS CONTINUE ACROSS PARTS OF WEST AND SOUTH CENTRAL
NORTH DAKOTA EARLY THIS AFTERNOON. THE LATEST RAP STILL SHOWS
LIGHT PRECIPITATION ACROSS THE FAR SOUTHWEST FOR ANOTHER COUPLE
HOURS...SO WILL MAINTAIN A SLIGHT CHANCE POP IN THAT AREA. BAKER
MONTANA REPORTED LIGHT RAIN IN THE PAST HOUR...AND WITH SURFACE
TEMPERATURES ACROSS THE SOUTHWEST NOW IN THE MID 30S...THE PREVAILING
PRECIPITATION TYPE SHOULD BE RAIN.
UPDATE ISSUED AT 959 AM CST SAT NOV 30 2013
A WEAK UPPER WAVE WILL CONTINUE TO MOVE ACROSS WESTERN / SOUTHERN
NORTH DAKOTA TODAY. AREA RADARS SHOW WEAK RETURNS ACROSS WESTERN
AND CENTRAL NORTH DAKOTA...HOWEVER DRY AIR AS SHOWN IN THE 12Z
BISMARCK SOUNDING HAS PREVENTED MOST OF THE PRECIPITATION FROM
REACHING THE GROUND. THE 30.12Z NAM STILL SUGGESTS THERE COULD BE
LIGHT PRECIPITATION IN THE SOUTHWEST INTO EARLY AFTERNOON...SO
WILL KEEP A SLIGHT CHANCE POP IN THAT AREA. PRECIPITATION TYPE IS
ALSO A CHALLENGE WITH THERMAL PROFILES SUGGESTING MAINLY RAIN /
FREEZING RAIN THIS MORNING...BUT COOLER AIR BY EARLY AFTERNOON
COULD CAUSE A TRANSITION TO A RAIN / SNOW MIX.
STRATUS ACROSS THE EASTERN PART OF NORTH DAKOTA HAS BEEN TRENDING
STEADILY WESTWARD THIS MORNING. THE CURRENT FORECAST COVERS THIS
WELL IN THE SKY GRIDS...BUT DECIDED TO MODIFY HIGH TEMPERATURES
DOWNWARD A COUPLE OF DEGREES TOWARDS THE TURTLE MOUNTAINS WHERE
THE CLOUDS WILL ARRIVE FIRST.
UPDATE
ISSUED AT 637 AM CST SAT NOV 30 2013
WEAK EMBEDDED ENERGY MOVING EAST-SOUTHEAST ACROSS MONTANA
CONTINUES TO GENERATE EXTENSIVE CLOUDS FROM THE NORTHERN ROCKIES
EAST ACROSS WEST INTO SOUTH CENTRAL NORTH DAKOTA. WITH SFC OBS
REPORTING MAINLY OVC CONDITIONS...BEEFED UP SKY COVER. WILL
MAINTAIN SLIGHT CHANCES FOR SNOW OR LIGHT FREEZING RAIN WEST
CENTRAL INTO SOUTHWEST. EXPECT LITTLE MOISTURE IS REACHING THE
GROUND WITH CIGS OVER 5K FEET AGL. HOWEVER...DID HAVE REPORTS OF
-ZR AT WOLF POINT IN NORTHEAST MONTANA A COUPLE OF HOURS AGO...SO
ALTHOUGH LIMITED WE SHOULD SEE ISOLATED PRECIP.
CURRENT CLOUDS ARE PROJECTED TO REMAIN FOR MOST OF THIS MORNING IF
NOT THROUGH THE AFTERNOON WITH ANOTHER WEAK IMPULSE APPROACHING MY
NORTHWEST EARLY THIS AFTERNOON IN OUR NORTHWEST FLOW ALOFT.
LAST BIG CHANGE WITH THIS UPDATE WAS TO INCREASE CLOUDS OVER MY
NORTH CENTRAL TRENDING SOUTH. LARGE AREA OF LOW STRATUS TO OUR
NORTH ACROSS SOUTH CENTRAL CANADA IS SLOWLY MOVING SOUTH. LATEST
RAP AND NAM SHOW THE STRATUS REACHING MY NORTH CENTRAL/NORTHEAST
14-15Z THEN CONTINUING SOUTH AND EAST...REACHING THE JAMES VALLEY
18-21Z...AND THE SD BORDER BY MID EVENING...THEN PERSISTING
THROUGH THE NIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM CST SAT NOV 30 2013
REPORTS OF LIGHT FREEZING RAIN FROM NORTHEASTERN MONTANA CONFIRM
THAT SOME OF THE PRECIPITATION INDICATED ON RADAR IMAGERY IS
REACHING THE GROUND. IT APPEARS THIS ACTIVITY WILL SLOWLY SLIDE
SOUTHEAST TODAY. WHILE TRAVEL IMPACTS ARE NOT EXPECTED...THERE
COULD BE A BAND OR TWO OF PRECIPITATION THAT RESULTS IN ICY ROADS
BETWEEN WILLISTON AND HETTINGER...AND WESTWARD TODAY.
THERE WAS A LARGE SLOWDOWN IN THE ONSET OF PRECIPITATION FROM THE
FIRST SHORTWAVE DUE INTO THE STATE ON SUNDAY. NOW...THE 00 UTC
ECMWF/GFS/GEM GLOBAL/NAM ALL KEEP QPF OUT OF NORTH DAKOTA UNTIL
SUNDAY MORNING AROUND 3 AM CST. PRECIPITATION CHANCES WERE HELD TO
THE NORTHWESTERN COUNTIES UNTIL SUNRISE SUNDAY MORNING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM CST SAT NOV 30 2013
A PROLONGED PERIOD OF WINTER WEATHER REMAINS THE MAIN HIGHLIGHT IN
THE LONG TERM PERIOD...WITH INCREASING POTENTIAL FOR A MAJOR WINTER
STORM TUESDAY-WEDNESDAY NIGHT. 00Z MODELS HAVE TRENDED INTO MUCH
BETTER AGREEMENT FOR SUNDAY/SUNDAY NIGHT...WITH UNCERTAINTY
DECREASING QUITE A BIT FOR MONDAY. UNCERTAINTY STILL REMAINS
ELEVATED AFTERWARDS FOR TUESDAY AND ON.
UPPER LEVEL LOW PRESSURE OVER ALASKA HAS STARTED ITS SOUTHWARD
JOURNEY THIS MORNING...AND WILL TRACK SOUTH ALONG THE BRITISH
COLUMBIA COAST OVER THE WEEKEND DROPPING INTO THE PACIFIC NORTHWEST
ON MONDAY. AN UNASSOCIATED EMBEDDED S/WV IMPULSE CURRENTLY SOUTH OF
THIS FEATURE OVER THE NORTHEAST PACIFIC WILL TRACK EAST-SOUTHEAST
ONSHORE THIS MORNING THEN ACROSS THE ROCKIES TONIGHT ON THE NOSE OF
AN UPPER LEVEL JET. LEE SIDE SFC TROUGH DEVELOPS TONIGHT IN RESPONSE
TO THE INCREASING UPPER LEVEL DIVERGENCE. MODELS HAVE TRENDED SLOWER
WITH PRECIPITATION INITIALIZATION WITH THERMAL UPGLIDE EAST OF THE
TROUGH AND BEST DIVERGENCE ALOFT FOR ASCENT NOW TAKING PLACE OVER
WESTERN NORTH DAKOTA 12-18Z SUNDAY MORNING. OVERRUNNING FLOW AND
UPPER LEVEL SUPPORT IN THE LEFT EXIT REGION OF THE JET WILL SPREAD
EASTWARD SUNDAY AFTERNOON AND EVENING. THIS FIRST WAVE OF MOISTURE
STALLS ACROSS THE EAST GRADUALLY DIMINISHING AS FORCING WANES IN
RESPONSE TO DECREASING SUPPORT ALOFT. GENERALLY LIGHT QPF WITH THIS
FIRST WAVE UP TO A TENTH OF AN INCH OF MOISTURE...RESULTING IN
SNOWFALL AMOUNTS MAYBE AROUND AN INCH NORTH AND EAST. STILL
POTENTIAL FOR MIXED PRECIPITATION SOUTHWEST IN THE MORNING MAINLY IN
THE FORM OF SLEET WITH THE WARM LAYER WET BULB AROUND 1-3C. RAIN
WILL BE POSSIBLE ACROSS THE SOUTH CENTRAL WITH TEMPERATURES WARMING
TO NEAR 40F IN THE AFTERNOON.
MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH THE NEXT WAVE OF
MOISTURE...ASSOCIATED WITH A POTENT LEAD SHORT WAVE ORIGINATING WITH
THE UPPER LOW. PRECIPITATION IS FORECAST TO DEVELOP ACROSS MONTANA
SUNDAY EVENING...SPREADING EASTWARD SUNDAY NIGHT INTO MONDAY DAYTIME
ACROSS NORTH DAKOTA. MORE LIFT WILL BE PRESENT WITH THIS FEATURE
MAKING IT MORE PRODUCTIVE THAN SUNDAY`S DISTURBANCE WITH
PRECIPITATION PRODUCTION. QPF UP TO A QUARTER OF AN INCH WILL BE
ADVERTISED WRAPPING AROUND A SFC LOW FORECAST TO MOVE FROM EASTERN
MONTANA MONDAY MORNING INTO WESTERN SOUTH DAKOTA MONDAY EVENING.
THIS TRACK PUTS THE HIGHER QPF OVER MY NORTH..CENTRAL...AND EAST.
SIMILAR THERMAL PROFILE AS ON SUNDAY RESULTS IN ANOTHER CHANCE OF
MIXED PRECIPITATION SOUTHWEST. SFC TEMPS MAY BE WARMER RESULTING
IN MORE OF A RAIN/SNOW MIX VERSUS SLEET. IN FACT...MODELS WARM UP
THE SOUTHWEST AND SOUTH CENTRAL TO SUPPORT ALL RAIN LATER MONDAY
MORNING INTO THE AFTERNOON BEFORE CAA OVERTAKES THE STATE BY 00Z
TUESDAY. WITH THE HIGHER QPF WILL SEE HIGHER SNOWFALL
TOTALS...ONCE AGAIN ACROSS THE NORTH AND MY EAST WHERE ALL SNOW IS
FORECAST...UP TO 4 INCHES POSSIBLE. THUS WILL NEED TO KEEP A CLOSE
EYE ON MODEL TRENDS IN CASE A WINTER WEATHER ADVISORY BECOMES
NEEDED LATE SUNDAY NIGHT THROUGH MONDAY.
THIRD...FINAL...AND POSSIBLY GREATEST WAVE OF PRECIPITATION WILL
INITIATE WEST LATE MONDAY NIGHT...POTENTIALLY LASTING THROUGH
TUESDAY AND MUCH OF WEDNESDAY...AS THE UPPER LOW MOVES ACROSS THE
ROCKIES THEN LIFTS THROUGH THE NORTHERN PLAINS SOMETIME TUESDAY
NIGHT OR WEDNESDAY. STILL LOTS OF SPREAD AMONGST MODELS WITH A
VARIETY OF SOLUTIONS PRESENT WHEN COMPARING THE 00Z RUNS OF THE
GFS/GEM/ECMWF. THE LAST SEVERAL RUNS OF THE ECMWF HAVE BEEN THE
MOST CONSISTENT...WHICH BRINGS THE HEAVIEST SNOW AND STRONGEST
WINDS TO NORTH DAKOTA TUESDAY THROUGH WEDNESDAY NIGHT THANKS TO
AN INVERTED SFC TROUGH ACROSS THE DAKOTAS. BOTH THE GFS AND GEM
BRING LESS SNOW WITH THE GFS MUCH FASTER AND THE GEM FARTHER TO
THE SOUTH WITH LOW PRESSURE. WILL CONTINUE TO MONITOR MODEL TRENDS
CLOSE OVER THE NEXT FEW DAYS.
WHILE THE SNOW POTENTIAL REMAINS UNCERTAIN MID-WEEK...MORE
CONFIDENCE IN COLD ARCTIC AIR SURGING SOUTH IN THE UPPER LOWS WAKE
WEDNESDAY INTO FRIDAY...AND REMAINING ENTRENCHED OVER THE NORTHERN
PLAINS THROUGH NEXT WEEKEND. SUBZERO HIGHS ARE FORECAST...WITH
LOWS 20 BELOW OR COLDER.
WILL CONTINUE TO MENTION THE ABOVE HAZARDS IN A SPECIAL WEATHER
STATEMENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1258 PM CST SAT NOV 30 2013
AFTERNOON VISIBLE SATELLITE IMAGERY SHOW STRATUS ACROSS PARTS OF
SOUTHERN CANADA MOVING SOUTH TOWARDS NORTHERN NORTH DAKOTA. THE
LATEST RAP MODEL SUGGESTS THE STRATUS COULD REACH KMOT AND BY LATE
AFTERNOON...AND THEN CONTINUE TO SPREAD SOUTH TONIGHT. LOWER
CLOUDS ARE ALSO POSSIBLE AS A CHANCE OF PRECIPITATION MOVES
TOWARDS THE REGION LATE TONIGHT INTO SUNDAY. OVERALL...WILL SHOW
A DOWNWARD TREND IN REGARDS TO CEILINGS...WITH VISIBILITY
RESTRICTIONS POSSIBLE AS PRECIPITATION CHANCES INCREASE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...SCHECK
LONG TERM...NH
AVIATION...CK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1224 PM CST SAT NOV 30 2013
.UPDATE...
ISSUED AT 1224 PM CST SAT NOV 30 2013
ADJUSTED CLOUDS TO REFLECT CURRENT SAT TRENDS...AND ADDED SOME
PATCHY FOG IN THE NORTHWEST WHERE LANGDON OBS AND WEB CAMS SHOW
SOME REDUCED VIS. SOUTHWARD AND WESTWARD PROGRESSION OF THE LOW
CLOUDS HAS SLOWED A BIT...SO BUMPED UP HIGHS SLIGHTLY IN THE FAR
WEST AND SOUTHWEST WHERE THEY HAVE SEEN SOME SUN. LOWERED HIGHS A
BIT IN THE NORTH AND CENTRAL COUNTIES WHERE STRATUS HAS KEEP US
FROM RISING MORE THAN A FEW DEGREES.
UPDATE ISSUED AT 946 AM CST SAT NOV 30 2013
LOWERED HIGHS FOR TODAY ACROSS THE NORTHWESTERN COUNTIES AND
DROPPED THEM EVEN A DEGREE OR SO DOWN TO FARGO. CLEAR SKIES
ALLOWED TEMPS AROUND KDVL TO DROP INTO THE LOWER TEENS...AND WITH
STRATUS MOVING IN THERE WILL BE NOT TOO MUCH RISE THIS AFTERNOON.
AT THIS TIME THE SOUTHWESTERN CWA COULD STILL SEE SOME SUN AND
CLIMB INTO THE MID 30S...BUT THERE ARE MORE MID CLOUDS MOVING IN
FROM THE WEST. MADE SOME FURTHER TWEAKS TO CLOUDS AND WILL KEEP AN
EYE ON TEMPS IN CASE THEY NEED TO BE DROPPED MORE LATER ON TODAY.
UPDATE ISSUED AT 644 AM CST SAT NOV 30 2013
WILL NEED TO INCREASE SKY TODAY. THE RAP GUIDANCE IS VERIFYING THE
BEST...SHOWING THE LOW LEVEL CIGS FROM CANADA ADVECTING INTO THE
FORECAST AREA. WILL FOLLOW THE 09Z RAP FOR ARRIVAL TIMES. WILL
ALSO KEEP THE REGION CLOUDY THROUGH THE OVERNIGHT HOURS.
FORECASTED MAX TEMPS TODAY MAY BE A BIT HIGH...BUT SHOULD BE IN
THE BALL PARK. FORECASTED MIN TEMPS TONIGHT ARE LIKELY TOO COLD
(IF CLOUDS STICK AROUND AS EXPECTED). WILL CONCENTRATE ON SKY FOR
THIS UPDATE...AND WORRY ABOUT TEMPS WITH THE NEXT UPDATES.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
00Z MODELS INITIALIZED WITH MINIMAL ERRORS AND ARE IN GOOD
AGREEMENT THROUGH SUNDAY. THE CHALLENGE FOR TODAY WILL BE
TEMPERATURES AND CLOUD COVER. THE CHALLENGE FOR SUNDAY WILL BE -SN
CHANCES.
TODAY-TONIGHT...WEAK COLD FRONT WILL BE THROUGH THE REGION WHICH
SHOULD LEAD TO SLIGHTLY COOLER TEMPERATURES THAN YESTERDAY. THE
MID-LEVEL CLOUDS ALONG AND AHEAD OF THIS FEATURE WILL MOVE
SOUTH...BUT WILL NEED TO WATCH THE LOW-LEVEL CIGS APPROACHING FROM
THE NORTH. 06Z RAP IS MOST AGGRESSIVE BRINGING THESE CIGS INTO THE
ENTIRE FA...WHILE MOST OTHER GUIDANCE SUGGESTS ONLY PORTIONS OF NW
MN WILL BE AFFECTED. WILL SIDE WITH THE MAJORITY...AND TAKE A
CLOSER LOOK AT THE 7AM UPDATE.
SUNDAY...00Z MODELS HAVE SLOWED THE SHORTWAVE BRINGING -SN
CHANCES...ADJUSTED POPS ACCORDINGLY. MUCH OF SUNDAY SHOULD BE DRY
(UNTIL THE EVENING HOURS).
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
SUNDAY NIGHT-MONDAY NIGHT...00Z MODELS BEGIN TO DIVERGE...WITH THE
ECMWF/GEM/UKMET DIGGING THE UPPER LOW INTO THE NW CONUS BY 12Z
TUE...AND THE NAM/GFS BRINGING THIS FEATURE INTO MONTANA/WESTERN
DAKOTAS. THE ECMWF/GEM/UKMET HAVE BEEN THE MORE CONSISTENT
MODELS...AND ARE SUPPORTED BY ENSEMBLES (WILL FOLLOW FOR FORECAST
DETAILS). THERE WILL BE A COUPLE LEAD SHORTWAVES EJECTING FROM THE
MAIN UPPER TROUGH. THE FIRST WILL MOVE THROUGH THE REGION SUNDAY
NIGHT...AND THE SECOND MONDAY AFTERNOON/NIGHT. SINCE THERE HAVE
BEEN A FEW MODEL RUNS INDICATING THESE FEATURES...WILL INCREASE
POPS TO LIKELY AND ATTEMPT TO TIME THESE FEATURES THROUGH THE
REGION. THE FIRST WAVE IS WEAKER...AND SHOULD HAVE LESS AVAILABLE
MOISTURE. MESOSCALE FORCING IS ALSO WEAK...SO UP TO AN INCH OF
SNOWFALL APPEARS POSSIBLE (MAYBE 2 INCHES). THE SECOND WAVE IS
STRONGER...WITH MORE AVAILABLE MOISTURE (PWATS APPROACHING 0.5
INCHES). MODELS INDICATE A DEFINED CIRCULATION AT 850MB (AND A
WEAK 700MB LOW) PROPAGATING FROM NW ND INTO SE ND ON
MONDAY...LOSING DEFINITION MONDAY NIGHT AS IT PROPAGATES FURTHER
TO THE SE. ASSOCIATED WARM AIR ADVECTION/DEFORMATION COMBINED
WITH THE 0.5 INCH PWATS SHOULD LEAD TO A FEW INCHES OF SNOWFALL.
MODELS INDICATE 0.25-0.40 INCHES QPF ACROSS ALL BUT THE NE
FA...AND COMBINED WITH 12:1-13:1 SNOW RATIOS WOULD LEAD TO AN AREA
OF 3-5 INCHES OF SNOW. P-TYPE WILL BE ALL SNOW IF THE EXPECTED
SOLUTION VERIFIES. THE NAM/SREF/GFS HAVE WARMER MID-LEVEL
TEMPERATURES SINCE THE UPPER WAVE IS CLOSER TO THE REGION (LOW
LEVEL SOUTHERLY FLOW IS STRONGER)...AND WOULD LEAD TO FZRA/RA
POTENTIAL (BUT THIS PROBABILITY SEEMS VERY LOW ATTM).
TUESDAY-FRIDAY...A VERY WINTRY PERIOD IS IN STORE...WITH THE MAIN
FOCUS INITIALLY BEING SNOW POTENTIAL THROUGH MID-WEEK FOLLOWED BY
A COLD ARCTIC AIR MASS SPILLING SOUTH.
MODEL SPREAD CONTINUES TO BE SIGNIFICANT...ALTHOUGH THE ECMWF HAS
SHOWN BETTER CONSISTENCY OVER THE PAST FEW RUNS...SO HAVE TRENDED A
BIT IN THAT DIRECTION. THE 00Z GFS/ECMWF BOTH BRING THE UPPER TROUGH
EASTWARD INTO THE PLAINS WED/THU. HOWEVER...A CHALLENGE CONTINUES TO
BE TIMING OF EMBEDDED WAVES. THE ECMWF REMAINS DEEPEST AND FARTHEST
WEST WITH SFC LOW DEVELOPMENT FROM THE CENTRAL PLAINS NORTHEAST INTO
ONTARIO IN CONJUNCTION WITH A STRONG SHORTWAVE TROUGH ASSOCIATED
WITH THE LIFTING UPPER LOW...WHILE THE GFS IS MORE PROGRESSIVE WITH
A WEAKER SFC LOW ASSOCIATED WITH A LEAD WAVE. THUS...THE ECMWF AND
TO A LESSER EXTENT THE GEM ARE MORE AGGRESSIVE WITH QPF. THE 500 MB
GFS ENSEMBLE MEAN HEIGHT FIELD GENERALLY SUPPORTS THE ECMWF BROADLY.
CONFIDENCE STILL IS RATHER LOW REGARDING THE PLACEMENT AND MAGNITUDE
OF SNOWFALL...ALTHOUGH THE MID-WEEK PERIOD WILL CONTINUE TO BEAR
WATCHING FOR ACCUMULATING SNOWFALL.
ARCTIC AIR WILL BLAST SOUTH DURING THE LATTER PART OF THE
WEEK INTO NEXT WEEKEND. THE ECMWF CONTINUES TO INDICATE 925 MB TEMPS
DOWN TO -20 TO -25C THURSDAY/FRIDAY BEHIND INITIAL SURGE OF COLD
ADVECTION. BLUSTERY WINDS WILL COMBINE WITH VERY COLD TEMPS TO
PRODUCE POTENTIALLY HAZARDOUS WIND CHILLS AT TIMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1224 PM CST SAT NOV 30 2013
MAIN CHALLENGE FOR AVIATION IS CIGS. BAND OF MVFR/IFR CIGS SPREADING
OVER THE AREA AND OBS UPSTREAM SHOWS SOME VARIANCE BETWEEN 800 TO
1500 FEET. HARD TO NAIL DOWN EXACT CIG HEIGHTS WITH THE STRATUS
DECK...SO WENT WITH PERSISTENCE ATTM AND KEPT CIGS GENERALLY AROUND
1000 FEET. EXPECT SOME VARIABILITY IN VSBY AS WELL...BUT WILL KEEP
IN VFR CATEGORY FOR NOW. OTHERWISE...VERY WEAK PRESSURE GRADIENT IS
EXPECTED TO PERSIST OVER THE AREA THRU THE TAF PERIOD SO KEPT WINDS
ON THE LIGHT SIDE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
946 AM CST SAT NOV 30 2013
.UPDATE...
ISSUED AT 946 AM CST SAT NOV 30 2013
LOWERED HIGHS FOR TODAY ACROSS THE NORTHWESTERN COUNTIES AND
DROPPED THEM EVEN A DEGREE OR SO DOWN TO FARGO. CLEAR SKIES
ALLOWED TEMPS AROUND KDVL TO DROP INTO THE LOWER TEENS...AND WITH
STRATUS MOVING IN THERE WILL BE NOT TOO MUCH RISE THIS AFTERNOON.
AT THIS TIME THE SOUTHWESTERN CWA COULD STILL SEE SOME SUN AND
CLIMB INTO THE MID 30S...BUT THERE ARE MORE MID CLOUDS MOVING IN
FROM THE WEST. MADE SOME FURTHER TWEAKS TO CLOUDS AND WILL KEEP AN
EYE ON TEMPS IN CASE THEY NEED TO BE DROPPED MORE LATER ON TODAY.
UPDATE ISSUED AT 644 AM CST SAT NOV 30 2013
WILL NEED TO INCREASE SKY TODAY. THE RAP GUIDANCE IS VERIFYING THE
BEST...SHOWING THE LOW LEVEL CIGS FROM CANADA ADVECTING INTO THE
FORECAST AREA. WILL FOLLOW THE 09Z RAP FOR ARRIVAL TIMES. WILL
ALSO KEEP THE REGION CLOUDY THROUGH THE OVERNIGHT HOURS.
FORECASTED MAX TEMPS TODAY MAY BE A BIT HIGH...BUT SHOULD BE IN
THE BALL PARK. FORECASTED MIN TEMPS TONIGHT ARE LIKELY TOO COLD
(IF CLOUDS STICK AROUND AS EXPECTED). WILL CONCENTRATE ON SKY FOR
THIS UPDATE...AND WORRY ABOUT TEMPS WITH THE NEXT UPDATES.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
00Z MODELS INITIALIZED WITH MINIMAL ERRORS AND ARE IN GOOD
AGREEMENT THROUGH SUNDAY. THE CHALLENGE FOR TODAY WILL BE
TEMPERATURES AND CLOUD COVER. THE CHALLENGE FOR SUNDAY WILL BE -SN
CHANCES.
TODAY-TONIGHT...WEAK COLD FRONT WILL BE THROUGH THE REGION WHICH
SHOULD LEAD TO SLIGHTLY COOLER TEMPERATURES THAN YESTERDAY. THE
MID-LEVEL CLOUDS ALONG AND AHEAD OF THIS FEATURE WILL MOVE
SOUTH...BUT WILL NEED TO WATCH THE LOW-LEVEL CIGS APPROACHING FROM
THE NORTH. 06Z RAP IS MOST AGGRESSIVE BRINGING THESE CIGS INTO THE
ENTIRE FA...WHILE MOST OTHER GUIDANCE SUGGESTS ONLY PORTIONS OF NW
MN WILL BE AFFECTED. WILL SIDE WITH THE MAJORITY...AND TAKE A
CLOSER LOOK AT THE 7AM UPDATE.
SUNDAY...00Z MODELS HAVE SLOWED THE SHORTWAVE BRINGING -SN
CHANCES...ADJUSTED POPS ACCORDINGLY. MUCH OF SUNDAY SHOULD BE DRY
(UNTIL THE EVENING HOURS).
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
SUNDAY NIGHT-MONDAY NIGHT...00Z MODELS BEGIN TO DIVERGE...WITH THE
ECMWF/GEM/UKMET DIGGING THE UPPER LOW INTO THE NW CONUS BY 12Z
TUE...AND THE NAM/GFS BRINGING THIS FEATURE INTO MONTANA/WESTERN
DAKOTAS. THE ECMWF/GEM/UKMET HAVE BEEN THE MORE CONSISTENT
MODELS...AND ARE SUPPORTED BY ENSEMBLES (WILL FOLLOW FOR FORECAST
DETAILS). THERE WILL BE A COUPLE LEAD SHORTWAVES EJECTING FROM THE
MAIN UPPER TROUGH. THE FIRST WILL MOVE THROUGH THE REGION SUNDAY
NIGHT...AND THE SECOND MONDAY AFTERNOON/NIGHT. SINCE THERE HAVE
BEEN A FEW MODEL RUNS INDICATING THESE FEATURES...WILL INCREASE
POPS TO LIKELY AND ATTEMPT TO TIME THESE FEATURES THROUGH THE
REGION. THE FIRST WAVE IS WEAKER...AND SHOULD HAVE LESS AVAILABLE
MOISTURE. MESOSCALE FORCING IS ALSO WEAK...SO UP TO AN INCH OF
SNOWFALL APPEARS POSSIBLE (MAYBE 2 INCHES). THE SECOND WAVE IS
STRONGER...WITH MORE AVAILABLE MOISTURE (PWATS APPROACHING 0.5
INCHES). MODELS INDICATE A DEFINED CIRCULATION AT 850MB (AND A
WEAK 700MB LOW) PROPAGATING FROM NW ND INTO SE ND ON
MONDAY...LOSING DEFINITION MONDAY NIGHT AS IT PROPAGATES FURTHER
TO THE SE. ASSOCIATED WARM AIR ADVECTION/DEFORMATION COMBINED
WITH THE 0.5 INCH PWATS SHOULD LEAD TO A FEW INCHES OF SNOWFALL.
MODELS INDICATE 0.25-0.40 INCHES QPF ACROSS ALL BUT THE NE
FA...AND COMBINED WITH 12:1-13:1 SNOW RATIOS WOULD LEAD TO AN AREA
OF 3-5 INCHES OF SNOW. P-TYPE WILL BE ALL SNOW IF THE EXPECTED
SOLUTION VERIFIES. THE NAM/SREF/GFS HAVE WARMER MID-LEVEL
TEMPERATURES SINCE THE UPPER WAVE IS CLOSER TO THE REGION (LOW
LEVEL SOUTHERLY FLOW IS STRONGER)...AND WOULD LEAD TO FZRA/RA
POTENTIAL (BUT THIS PROBABILITY SEEMS VERY LOW ATTM).
TUESDAY-FRIDAY...A VERY WINTRY PERIOD IS IN STORE...WITH THE MAIN
FOCUS INITIALLY BEING SNOW POTENTIAL THROUGH MID-WEEK FOLLOWED BY
A COLD ARCTIC AIR MASS SPILLING SOUTH.
MODEL SPREAD CONTINUES TO BE SIGNIFICANT...ALTHOUGH THE ECMWF HAS
SHOWN BETTER CONSISTENCY OVER THE PAST FEW RUNS...SO HAVE TRENDED A
BIT IN THAT DIRECTION. THE 00Z GFS/ECMWF BOTH BRING THE UPPER TROUGH
EASTWARD INTO THE PLAINS WED/THU. HOWEVER...A CHALLENGE CONTINUES TO
BE TIMING OF EMBEDDED WAVES. THE ECMWF REMAINS DEEPEST AND FARTHEST
WEST WITH SFC LOW DEVELOPMENT FROM THE CENTRAL PLAINS NORTHEAST INTO
ONTARIO IN CONJUNCTION WITH A STRONG SHORTWAVE TROUGH ASSOCIATED
WITH THE LIFTING UPPER LOW...WHILE THE GFS IS MORE PROGRESSIVE WITH
A WEAKER SFC LOW ASSOCIATED WITH A LEAD WAVE. THUS...THE ECMWF AND
TO A LESSER EXTENT THE GEM ARE MORE AGGRESSIVE WITH QPF. THE 500 MB
GFS ENSEMBLE MEAN HEIGHT FIELD GENERALLY SUPPORTS THE ECMWF BROADLY.
CONFIDENCE STILL IS RATHER LOW REGARDING THE PLACEMENT AND MAGNITUDE
OF SNOWFALL...ALTHOUGH THE MID-WEEK PERIOD WILL CONTINUE TO BEAR
WATCHING FOR ACCUMULATING SNOWFALL.
ARCTIC AIR WILL BLAST SOUTH DURING THE LATTER PART OF THE
WEEK INTO NEXT WEEKEND. THE ECMWF CONTINUES TO INDICATE 925 MB TEMPS
DOWN TO -20 TO -25C THURSDAY/FRIDAY BEHIND INITIAL SURGE OF COLD
ADVECTION. BLUSTERY WINDS WILL COMBINE WITH VERY COLD TEMPS TO
PRODUCE POTENTIALLY HAZARDOUS WIND CHILLS AT TIMES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 644 AM CST SAT NOV 30 2013
MAJOR CHANGE WITH THE 12Z TAF ISSUANCE TO BRING MVFR CIGS INTO THE
REGION TODAY. USED THE 09Z RAP FOR HELP WITH ARRIVAL TIMES.
SATELLITE IMAGERY INDICATES THESE CIGS CONTINUE TO ADVECT
SOUTHWARD FROM CANADA...WITH THE RAP GUIDANCE HANDLING THIS
SCENARIO THE BEST. THESE CIGS WILL LIKELY REMAIN THROUGH THE
OVERNIGHT HOURS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
644 AM CST SAT NOV 30 2013
.UPDATE...
ISSUED AT 644 AM CST SAT NOV 30 2013
WILL NEED TO INCREASE SKY TODAY. THE RAP GUIDANCE IS VERIFYING THE
BEST...SHOWING THE LOW LEVEL CIGS FROM CANADA ADVECTING INTO THE
FORECAST AREA. WILL FOLLOW THE 09Z RAP FOR ARRIVAL TIMES. WILL
ALSO KEEP THE REGION CLOUDY THROUGH THE OVERNIGHT HOURS.
FORECASTED MAX TEMPS TODAY MAY BE A BIT HIGH...BUT SHOULD BE IN
THE BALL PARK. FORECASTED MIN TEMPS TONIGHT ARE LIKELY TOO COLD
(IF CLOUDS STICK AROUND AS EXPECTED). WILL CONCENTRATE ON SKY FOR
THIS UPDATE...AND WORRY ABOUT TEMPS WITH THE NEXT UPDATES.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
00Z MODELS INITIALIZED WITH MINIMAL ERRORS AND ARE IN GOOD
AGREEMENT THROUGH SUNDAY. THE CHALLENGE FOR TODAY WILL BE
TEMPERATURES AND CLOUD COVER. THE CHALLENGE FOR SUNDAY WILL BE -SN
CHANCES.
TODAY-TONIGHT...WEAK COLD FRONT WILL BE THROUGH THE REGION WHICH
SHOULD LEAD TO SLIGHTLY COOLER TEMPERATURES THAN YESTERDAY. THE
MID-LEVEL CLOUDS ALONG AND AHEAD OF THIS FEATURE WILL MOVE
SOUTH...BUT WILL NEED TO WATCH THE LOW-LEVEL CIGS APPROACHING FROM
THE NORTH. 06Z RAP IS MOST AGGRESSIVE BRINGING THESE CIGS INTO THE
ENTIRE FA...WHILE MOST OTHER GUIDANCE SUGGESTS ONLY PORTIONS OF NW
MN WILL BE AFFECTED. WILL SIDE WITH THE MAJORITY...AND TAKE A
CLOSER LOOK AT THE 7AM UPDATE.
SUNDAY...00Z MODELS HAVE SLOWED THE SHORTWAVE BRINGING -SN
CHANCES...ADJUSTED POPS ACCORDINGLY. MUCH OF SUNDAY SHOULD BE DRY
(UNTIL THE EVENING HOURS).
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
SUNDAY NIGHT-MONDAY NIGHT...00Z MODELS BEGIN TO DIVERGE...WITH THE
ECMWF/GEM/UKMET DIGGING THE UPPER LOW INTO THE NW CONUS BY 12Z
TUE...AND THE NAM/GFS BRINGING THIS FEATURE INTO MONTANA/WESTERN
DAKOTAS. THE ECMWF/GEM/UKMET HAVE BEEN THE MORE CONSISTENT
MODELS...AND ARE SUPPORTED BY ENSEMBLES (WILL FOLLOW FOR FORECAST
DETAILS). THERE WILL BE A COUPLE LEAD SHORTWAVES EJECTING FROM THE
MAIN UPPER TROUGH. THE FIRST WILL MOVE THROUGH THE REGION SUNDAY
NIGHT...AND THE SECOND MONDAY AFTERNOON/NIGHT. SINCE THERE HAVE
BEEN A FEW MODEL RUNS INDICATING THESE FEATURES...WILL INCREASE
POPS TO LIKELY AND ATTEMPT TO TIME THESE FEATURES THROUGH THE
REGION. THE FIRST WAVE IS WEAKER...AND SHOULD HAVE LESS AVAILABLE
MOISTURE. MESOSCALE FORCING IS ALSO WEAK...SO UP TO AN INCH OF
SNOWFALL APPEARS POSSIBLE (MAYBE 2 INCHES). THE SECOND WAVE IS
STRONGER...WITH MORE AVAILABLE MOISTURE (PWATS APPROACHING 0.5
INCHES). MODELS INDICATE A DEFINED CIRCULATION AT 850MB (AND A
WEAK 700MB LOW) PROPAGATING FROM NW ND INTO SE ND ON
MONDAY...LOSING DEFINITION MONDAY NIGHT AS IT PROPAGATES FURTHER
TO THE SE. ASSOCIATED WARM AIR ADVECTION/DEFORMATION COMBINED
WITH THE 0.5 INCH PWATS SHOULD LEAD TO A FEW INCHES OF SNOWFALL.
MODELS INDICATE 0.25-0.40 INCHES QPF ACROSS ALL BUT THE NE
FA...AND COMBINED WITH 12:1-13:1 SNOW RATIOS WOULD LEAD TO AN AREA
OF 3-5 INCHES OF SNOW. P-TYPE WILL BE ALL SNOW IF THE EXPECTED
SOLUTION VERIFIES. THE NAM/SREF/GFS HAVE WARMER MID-LEVEL
TEMPERATURES SINCE THE UPPER WAVE IS CLOSER TO THE REGION (LOW
LEVEL SOUTHERLY FLOW IS STRONGER)...AND WOULD LEAD TO FZRA/RA
POTENTIAL (BUT THIS PROBABILITY SEEMS VERY LOW ATTM).
TUESDAY-FRIDAY...A VERY WINTRY PERIOD IS IN STORE...WITH THE MAIN
FOCUS INITIALLY BEING SNOW POTENTIAL THROUGH MID-WEEK FOLLOWED BY
A COLD ARCTIC AIR MASS SPILLING SOUTH.
MODEL SPREAD CONTINUES TO BE SIGNIFICANT...ALTHOUGH THE ECMWF HAS
SHOWN BETTER CONSISTENCY OVER THE PAST FEW RUNS...SO HAVE TRENDED A
BIT IN THAT DIRECTION. THE 00Z GFS/ECMWF BOTH BRING THE UPPER TROUGH
EASTWARD INTO THE PLAINS WED/THU. HOWEVER...A CHALLENGE CONTINUES TO
BE TIMING OF EMBEDDED WAVES. THE ECMWF REMAINS DEEPEST AND FARTHEST
WEST WITH SFC LOW DEVELOPMENT FROM THE CENTRAL PLAINS NORTHEAST INTO
ONTARIO IN CONJUNCTION WITH A STRONG SHORTWAVE TROUGH ASSOCIATED
WITH THE LIFTING UPPER LOW...WHILE THE GFS IS MORE PROGRESSIVE WITH
A WEAKER SFC LOW ASSOCIATED WITH A LEAD WAVE. THUS...THE ECMWF AND
TO A LESSER EXTENT THE GEM ARE MORE AGGRESSIVE WITH QPF. THE 500 MB
GFS ENSEMBLE MEAN HEIGHT FIELD GENERALLY SUPPORTS THE ECMWF BROADLY.
CONFIDENCE STILL IS RATHER LOW REGARDING THE PLACEMENT AND MAGNITUDE
OF SNOWFALL...ALTHOUGH THE MID-WEEK PERIOD WILL CONTINUE TO BEAR
WATCHING FOR ACCUMULATING SNOWFALL.
ARCTIC AIR WILL BLAST SOUTH DURING THE LATTER PART OF THE
WEEK INTO NEXT WEEKEND. THE ECMWF CONTINUES TO INDICATE 925 MB TEMPS
DOWN TO -20 TO -25C THURSDAY/FRIDAY BEHIND INITIAL SURGE OF COLD
ADVECTION. BLUSTERY WINDS WILL COMBINE WITH VERY COLD TEMPS TO
PRODUCE POTENTIALLY HAZARDOUS WIND CHILLS AT TIMES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 644 AM CST SAT NOV 30 2013
MAJOR CHANGE WITH THE 12Z TAF ISSUANCE TO BRING MVFR CIGS INTO THE
REGION TODAY. USED THE 09Z RAP FOR HELP WITH ARRIVAL TIMES.
SATELLITE IMAGERY INDICATES THESE CIGS CONTINUE TO ADVECT
SOUTHWARD FROM CANADA...WITH THE RAP GUIDANCE HANDLING THIS
SCENARIO THE BEST. THESE CIGS WILL LIKELY REMAIN THROUGH THE
OVERNIGHT HOURS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
337 AM CST SAT NOV 30 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
00Z MODELS INITIALIZED WITH MINIMAL ERRORS AND ARE IN GOOD
AGREEMENT THROUGH SUNDAY. THE CHALLENGE FOR TODAY WILL BE
TEMPERATURES AND CLOUD COVER. THE CHALLENGE FOR SUNDAY WILL BE -SN
CHANCES.
TODAY-TONIGHT...WEAK COLD FRONT WILL BE THROUGH THE REGION WHICH
SHOULD LEAD TO SLIGHTLY COOLER TEMPERATURES THAN YESTERDAY. THE
MID-LEVEL CLOUDS ALONG AND AHEAD OF THIS FEATURE WILL MOVE
SOUTH...BUT WILL NEED TO WATCH THE LOW-LEVEL CIGS APPROACHING FROM
THE NORTH. 06Z RAP IS MOST AGGRESSIVE BRINGING THESE CIGS INTO THE
ENTIRE FA...WHILE MOST OTHER GUIDANCE SUGGESTS ONLY PORTIONS OF NW
MN WILL BE AFFECTED. WILL SIDE WITH THE MAJORITY...AND TAKE A
CLOSER LOOK AT THE 7AM UPDATE.
SUNDAY...00Z MODELS HAVE SLOWED THE SHORTWAVE BRINGING -SN
CHANCES...ADJUSTED POPS ACCORDINGLY. MUCH OF SUNDAY SHOULD BE DRY
(UNTIL THE EVENING HOURS).
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 AM CST SAT NOV 30 2013
SUNDAY NIGHT-MONDAY NIGHT...00Z MODELS BEGIN TO DIVERGE...WITH THE
ECMWF/GEM/UKMET DIGGING THE UPPER LOW INTO THE NW CONUS BY 12Z
TUE...AND THE NAM/GFS BRINGING THIS FEATURE INTO MONTANA/WESTERN
DAKOTAS. THE ECMWF/GEM/UKMET HAVE BEEN THE MORE CONSISTENT
MODELS...AND ARE SUPPORTED BY ENSEMBLES (WILL FOLLOW FOR FORECAST
DETAILS). THERE WILL BE A COUPLE LEAD SHORTWAVES EJECTING FROM THE
MAIN UPPER TROUGH. THE FIRST WILL MOVE THROUGH THE REGION SUNDAY
NIGHT...AND THE SECOND MONDAY AFTERNOON/NIGHT. SINCE THERE HAVE
BEEN A FEW MODEL RUNS INDICATING THESE FEATURES...WILL INCREASE
POPS TO LIKELY AND ATTEMPT TO TIME THESE FEATURES THROUGH THE
REGION. THE FIRST WAVE IS WEAKER...AND SHOULD HAVE LESS AVAILABLE
MOISTURE. MESOSCALE FORCING IS ALSO WEAK...SO UP TO AN INCH OF
SNOWFALL APPEARS POSSIBLE (MAYBE 2 INCHES). THE SECOND WAVE IS
STRONGER...WITH MORE AVAILABLE MOISTURE (PWATS APPROACHING 0.5
INCHES). MODELS INDICATE A DEFINED CIRCULATION AT 850MB (AND A
WEAK 700MB LOW) PROPAGATING FROM NW ND INTO SE ND ON
MONDAY...LOSING DEFINITION MONDAY NIGHT AS IT PROPAGATES FURTHER
TO THE SE. ASSOCIATED WARM AIR ADVECTION/DEFORMATION COMBINED
WITH THE 0.5 INCH PWATS SHOULD LEAD TO A FEW INCHES OF SNOWFALL.
MODELS INDICATE 0.25-0.40 INCHES QPF ACROSS ALL BUT THE NE
FA...AND COMBINED WITH 12:1-13:1 SNOW RATIOS WOULD LEAD TO AN AREA
OF 3-5 INCHES OF SNOW. P-TYPE WILL BE ALL SNOW IF THE EXPECTED
SOLUTION VERIFIES. THE NAM/SREF/GFS HAVE WARMER MID-LEVEL
TEMPERATURES SINCE THE UPPER WAVE IS CLOSER TO THE REGION (LOW
LEVEL SOUTHERLY FLOW IS STRONGER)...AND WOULD LEAD TO FZRA/RA
POTENTIAL (BUT THIS PROBABILITY SEEMS VERY LOW ATTM).
TUESDAY-FRIDAY...A VERY WINTRY PERIOD IS IN STORE...WITH THE MAIN
FOCUS INITIALLY BEING SNOW POTENTIAL THROUGH MID-WEEK FOLLOWED BY
A COLD ARCTIC AIR MASS SPILLING SOUTH.
MODEL SPREAD CONTINUES TO BE SIGNIFICANT...ALTHOUGH THE ECMWF HAS
SHOWN BETTER CONSISTENCY OVER THE PAST FEW RUNS...SO HAVE TRENDED A
BIT IN THAT DIRECTION. THE 00Z GFS/ECMWF BOTH BRING THE UPPER TROUGH
EASTWARD INTO THE PLAINS WED/THU. HOWEVER...A CHALLENGE CONTINUES TO
BE TIMING OF EMBEDDED WAVES. THE ECMWF REMAINS DEEPEST AND FARTHEST
WEST WITH SFC LOW DEVELOPMENT FROM THE CENTRAL PLAINS NORTHEAST INTO
ONTARIO IN CONJUNCTION WITH A STRONG SHORTWAVE TROUGH ASSOCIATED
WITH THE LIFTING UPPER LOW...WHILE THE GFS IS MORE PROGRESSIVE WITH
A WEAKER SFC LOW ASSOCIATED WITH A LEAD WAVE. THUS...THE ECMWF AND
TO A LESSER EXTENT THE GEM ARE MORE AGGRESSIVE WITH QPF. THE 500 MB
GFS ENSEMBLE MEAN HEIGHT FIELD GENERALLY SUPPORTS THE ECMWF BROADLY.
CONFIDENCE STILL IS RATHER LOW REGARDING THE PLACEMENT AND MAGNITUDE
OF SNOWFALL...ALTHOUGH THE MID-WEEK PERIOD WILL CONTINUE TO BEAR
WATCHING FOR ACCUMULATING SNOWFALL.
ARCTIC AIR WILL BLAST SOUTH DURING THE LATTER PART OF THE
WEEK INTO NEXT WEEKEND. THE ECMWF CONTINUES TO INDICATE 925 MB TEMPS
DOWN TO -20 TO -25C THURSDAY/FRIDAY BEHIND INITIAL SURGE OF COLD
ADVECTION. BLUSTERY WINDS WILL COMBINE WITH VERY COLD TEMPS TO
PRODUCE POTENTIALLY HAZARDOUS WIND CHILLS AT TIMES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1146 PM CST FRI NOV 29 2013
SATELLITE AND SURFACE OBS INDICATE CIGS ABOVE 9 THOUSAND FT WERE
LOCATED OVER NORTHERN ND AND PARTS OF SOUTHEAST ND. MID LEVEL DECK
SHOULD CONTINUE TO MOVE SOUTHEAST THROUGH THE AREA TONIGHT AND SAT.
ALSO CLEAR SLOT OVER SOUTHERN SASK AND SOUTHWEST MAN CONTINUES TO
MOVE SOUTHEAST. ELSEWHERE CIGS AROUND 35 HUNDRED FT WERE LOCATED OVER
THE FAR NORTHEAST ZONES AND MAY CONTINUE THERE FOR THE REST OF THE
NIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
959 PM EST SUN DEC 1 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA TONIGHT...STALLING AND
DISSIPATING LATE ON MONDAY. INCREASING SOUTHERLY FLOW WILL ALLOW
FOR WARMING TEMPERATURES AND GRADUAL INCREASES FOR PRECIPITATION
CHANCES...BEFORE A STRONGER COLD FRONT MOVES THROUGH THE AREA
LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MID CLOUDS RACING E FROM IL WILL OVERSPREAD THE REGION IN THE NEXT
FEW HOURS. THEY WILL TOP THE LINGERING SC THAT HAS BEEN AFFECTING
PORTIONS OF THE REGION FOR MUCH OF THE DAY.
THE ADDITIONAL CLOUD COVER SHOULD KEEP THE TEMPERATURES IN THE N
FROM FALLING TOO MUCH MORE. EXPECT THE LOWS IN THE NORTH TO DROP
INTO THE LOWER 30S. MEANWHILE ACROSS THE SRN COUNTIES THE
TEMPERATURES SHOULD ONLY DROP INTO THE UPPER 30S..
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
ALTHOUGH NO SIGNIFICANT IMPACTS ARE EXPECTED DURING THE SHORT TERM
OF THE FORECAST...AND POPS ARE EXPECTED TO REMAIN IN THE CHANCE
RANGE OR LOWER...THE SPECIFIC DETAILS FOR PRECIPITATION AND CLOUDS
(IN TERMS OF AMOUNTS AND TIMING) ARE A LITTLE LOWER IN CONFIDENCE
THAN NORMAL.
THE BOUNDARY FORECAST TO MOVE INTO THE FORECAST AREA TONIGHT AND
INTO EARLY MONDAY MORNING WILL LOSE ITS DEFINITION...LEAVING THE
CWA IN A PATTERN OF VERY WEAK S-TO-SE FLOW. FLOW IN THE MID LEVELS
WILL BE QUASI-ZONAL...BUT WITH A SOMEWHAT-BROAD SHORTWAVE MOVING
INTO THE OHIO VALLEY ON MONDAY. THE OVERALL RESPONSE TO THIS
FEATURE IS NOT ESPECIALLY STRONG ON ALL MODELS BUT THE GFS (EVEN
ON BOTH THE 06Z AND 12Z RUNS). ALTHOUGH LOW LEVEL MOISTURE APPEARS
PREVALENT ON MOST MODELS...THE GFS IS BY FAR THE MOST ENHANCED
WITH DEEPER MOISTURE AND QPF RESPONSE. POPS FOR MONDAY AND INTO
MONDAY NIGHT HAVE BEEN SCALED BACK TO SLIGHT CHANCE...PUSHING
NORTH OF THE CWA BEFORE TUESDAY MORNING BEGINS.
AFTER WHAT LOOKS TO BE A DRY PERIOD ON TUESDAY...WARM FRONTAL
PROCESSES WILL BEGIN...AS LOW PRESSURE DEVELOPS OVER THE
MISSISSIPPI VALLEY. THIS WILL INCREASE THE SOUTHERLY FLOW AND
BEGIN A PATTERN OF WARM ADVECTION THAT WILL CONTINUE INTO THE LONG
TERM OF THE FORECAST. INCREASING CONVERGENCE AND MOISTURE
TRANSPORT (ESPECIALLY ALOFT ON TUESDAY NIGHT) WILL RESULT IN
PRECIPITATION CHANCES GRADUALLY INCREASING FROM WEST TO EAST
ACROSS THE CWA...THOUGH MOTION OF SHOWERS WILL BE IN MORE OF A
SSW-TO-NNE DIRECTION. THIS IS ONE PART OF THE FORECAST THAT DOES
COME WITH A BIT OF INCREASING CONFIDENCE. BECAUSE OF
THIS...TEMPERATURE ADJUSTMENTS WERE ALSO REQUIRED FOR BOTH TUESDAY
(SLIGHTLY UPWARD) AND TUESDAY NIGHT (SIGNIFICANTLY UPWARD).
PLENTIFUL CLOUDS AND MOISTURE...COMBINED REASONABLY STRONG FLOW
FOR AN OVERNIGHT PERIOD...SUPPORTS THIS DECISION. THE CURRENT
GRIDS WERE INCREASED BY 5-7 DEGREES...BUT IF SOME OF THE RAW
MODELS ARE TO BE BELIEVED...THIS MAY NOT EVEN BE ENOUGH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN WILL TRANSITION TO A HIGHLY AMPLIFIED REGIME
THROUGH THE EXTENDED PERIOD. THERE CONTINUES TO BE ISSUES WITH
TIMING AND RUN TO RUN CONTINUITY WITH MAJOR SYNOPTIC SYSTEMS TO
AFFECT OUR REGION. LOOKING AT THE VARIOUS OPERATIONAL MODELS...HAVE
DECIDED TO GO WITH A 25 PERCENT 12Z ECMWF AND A 75 PERCENT 12Z GFS.
WE ARE GETTING TO THE POINT IN THE FORECAST WHERE DIURNAL RISE AND
FALL WILL NOT CUT IT WITH FRONTS MOVING THROUGH AND WAVES OF LOW
PRESSURE RIDING ALONG THE FRONTAL BOUNDARY.
ON WEDNESDAY...LONG WAVE TROUGH WILL BE CARVING ITSELF OUT OVER THE
WESTERN U.S. FIRST WEATHER ISSUE IS THE AMOUNT OF ENERGY THAT WILL
EJECT FROM THIS FEATURE ACROSS THE NORTHERN PLAINS AND INTO CENTRAL
CANADA. GFS IS STRONGER AND FASTER WITH THIS ENERGY WHILE THE ECMWF
IS SLOWER...AND THIS HAS BEEN THE CASE OVER THE LAST SVRL RUNS. THIS
WILL HAVE FRONTAL IMPLICATIONS THROUGH OUR REGION WEDNESDAY INTO
THURSDAY. WITH AFOREMENTIONED BLEND...IT ALLOWS FOR A COLD FRONT TO
MOVE THROUGH THE REGION WEDNESDAY NIGHT...BUT NOT AS FAST AS THE GFS
INDICATES. IN ADVANCE OF THE FRONT...WAA SHOWERS ARE FORECAST TO
BREAK OUT AND LIKELY POPS SEEM REASONABLE AT THIS TIME.
FOR THE PERIOD THURSDAY INTO FRIDAY...THIS TIME FRAME IS SHAPING UP
TO BE INCLEMENT AS COLD FRONT SAGS TO OUR SOUTHEAST AND BECOMES
QUASI STATIONARY AS WAVES OF LOW PRESSURE RIDE ALONG IT. THESE WAVES
WILL BRING A SHOT OF FRONTOGENETIC FORCING TO OUR REGION LATE
THURSDAY INTO THURSDAY NIGHT WITH ANOTHER ROUND OF MID TO UPR LVL
FORCING FRIDAY INTO FRIDAY NIGHT. DURING THIS TIME...COLD AIR WILL
SLOWLY SEEP INTO THE REGION FROM THE NORTHWEST. AS SUCH...THERE WILL
BE SOME WINTRY PCPN TYPE ISSUES AS LOW LEVELS COOL BUT AIR ABOVE
WILL BE SLOWER TO COOL. STILL TO EARLY TO GET SPECIFIC GIVEN THE
THERMAL FIELD OSCILLATIONS AT THIS POINT SO JUST HAVE RAIN/SNOW
MENTIONED. LIKELY POPS STILL SEEM REASONABLE FOR MOST OF THE REGION
WITH EACH WAVE RIPPLING BY.
BY FRIDAY NIGHT INTO SATURDAY...COLD ARCTIC HIGH PRESSURE WILL WEDGE
SOUTHEAST INTO OUR AREA. THIS SHOULD PUSH THE PCPN OUT OF THE AREA
BY SATURDAY. THE HIGH WILL SET UP ACROSS THE REGION SATURDAY NIGHT
AND WILL MOVE EAST BY SUNDAY. THIS SHOULD GIVE THE REGION A DRY BUT
COLD PERIOD OF WEATHER.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
WEAK CDFNT CONTINUES TO SETTLE INTO THE REGION THIS EVENING. AREA
OF VFR SC THAT AFFECTED THE TAFS EARLIER TODAY HAS PUSHED E OF THE
NRN TAFS...BUT LINGERS DOWN ACROSS THE SOUTH. THE
MODELS...ESPECIALLY THE GFS...HAVE BEEN TOO PESSIMISTIC IN
FORECASTING MVFR CIGS FOR THIS AFTN. THEREFORE HAD GONE WITH A
MORE OPTIMISTIC FORECAST...BASED ON THE LAST COUPLE OF RUNS OF
THE RAP MODEL. THIS SCENARIO KEEPS THE VFR SC ACROSS THE SRN TAFS
FOR THE FIRST 3 OR 4 HOURS OF THE FORECAST...THEN ALLOWS THEM TO
WORK E. MID LEVEL CLOUDS ASSOCIATED WITH A S/W IN THE ZONAL H5
FLOW THEN PUSH IN BETWEEN 03Z-06Z IN THE W.
KEPT THE MENTION OF MVFR FOG AT SOME OF THE TAFS BETWEEN 09Z-13Z
AS THE LOW LEVELS MOISTENS OVERNIGHT. LATEST SATELLITE LOOP IS
FINALLY SHOWING SOME MVFR CLOUDS DEVELOPING IN NRN INDIANA. WILL
HAVE TO KEEP AN EYE ON THEM AND MIGHT HAVE TO PUT MVFR CIGS BACK
IN THE FORECAST FOR LATER TONIGHT.
COULD SEE SOME REDEVELOPMENT OF THE SC ON MONDAY...ESPECIALLY IN
THE SRN TAFS.
OUTLOOK...SOME MVFR CEILINGS POSSIBLE THROUGH TUESDAY MORNING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE AGAIN WEDNESDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...SITES
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
723 PM EST SUN DEC 1 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA TONIGHT...STALLING AND
DISSIPATING LATE ON MONDAY. INCREASING SOUTHERLY FLOW WILL ALLOW
FOR WARMING TEMPERATURES AND GRADUAL INCREASES FOR PRECIPITATION
CHANCES...BEFORE A STRONGER COLD FRONT MOVES THROUGH THE AREA
LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A WEAK FRONTAL BOUNDARY...EVIDENT MOST READILY WHEN LOOKING AT
SURFACE WINDS...IS CURRENTLY MOVING SOUTHWARD INTO OHIO. THERE IS
INCREASING LOW-LEVEL RH BEHIND THIS BOUNDARY...WITH A DRY AREA
CURRENTLY EXTENDING ACROSS MOST OF NORTHERN AND WESTERN OHIO AHEAD
OF IT. MEANWHILE...AN AREA OF THICK STRATOCUMULUS HAS BEEN VERY
GRADUALLY MOVING EAST ACROSS OHIO AND KENTUCKY TODAY. TIMING OUT
THE MOTIONS OF THESE DIFFERING RH LAYERS HAS BEEN A
CHALLENGE...WITH SEVERAL SCENARIOS IN THE MODELS AND WHAT SEEMS TO
BE A SLIGHT OVEREMPHASIS ON HIGHER RH VALUES. THE SLOW MOTION OF
THE CLOUDS COMING IN FROM THE NORTH LENDS ITSELF TO A PARTLY-
CLOUDY-AT-WORST FORECAST FOR MOST OF THE CWA (AT LEAST EARLY IN
THE OVERNIGHT...AND CERTAINLY NOT INCLUDING THE SOUTHEAST).
HOWEVER...CONFIDENCE DOES INCREASE THAT CLOUDS AND LOW-LEVEL RH
(PERHAPS VERY LOW) WILL BE IN PLACE BY MORNING. NAM AND RAP BUFKIT
SOUNDINGS SHOWED THE THICK MOISTURE CONFINED TO THE LOWEST 1000
FEET...THOUGH THE GFS APPEARED TOO AGGRESSIVE IN SATURATING
EVERYTHING UNDER 5KFT. THERE WAS EVEN SOME CONSIDERATION TO INCLUDING
DRIZZLE IN THE FORECAST...BUT LIFT IS NOT STRONG AND THE SOUTHWARD
EXTENT OF THE RH IS CERTAINLY IN QUESTION. DESPITE THE EXPECTED
CLOUDS...MIN TEMPS (ESPECIALLY IN THE NORTH) SHOULD AGAIN COOL TO
VALUES NEAR OR SLIGHTLY BELOW FREEZING...WITH MID TO UPPER 30S
ELSEWHERE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
ALTHOUGH NO SIGNIFICANT IMPACTS ARE EXPECTED DURING THE SHORT TERM
OF THE FORECAST...AND POPS ARE EXPECTED TO REMAIN IN THE CHANCE
RANGE OR LOWER...THE SPECIFIC DETAILS FOR PRECIPITATION AND CLOUDS
(IN TERMS OF AMOUNTS AND TIMING) ARE A LITTLE LOWER IN CONFIDENCE
THAN NORMAL.
THE BOUNDARY FORECAST TO MOVE INTO THE FORECAST AREA TONIGHT AND
INTO EARLY MONDAY MORNING WILL LOSE ITS DEFINITION...LEAVING THE
CWA IN A PATTERN OF VERY WEAK S-TO-SE FLOW. FLOW IN THE MID LEVELS
WILL BE QUASI-ZONAL...BUT WITH A SOMEWHAT-BROAD SHORTWAVE MOVING
INTO THE OHIO VALLEY ON MONDAY. THE OVERALL RESPONSE TO THIS
FEATURE IS NOT ESPECIALLY STRONG ON ALL MODELS BUT THE GFS (EVEN
ON BOTH THE 06Z AND 12Z RUNS). ALTHOUGH LOW LEVEL MOISTURE APPEARS
PREVALENT ON MOST MODELS...THE GFS IS BY FAR THE MOST ENHANCED
WITH DEEPER MOISTURE AND QPF RESPONSE. POPS FOR MONDAY AND INTO
MONDAY NIGHT HAVE BEEN SCALED BACK TO SLIGHT CHANCE...PUSHING
NORTH OF THE CWA BEFORE TUESDAY MORNING BEGINS.
AFTER WHAT LOOKS TO BE A DRY PERIOD ON TUESDAY...WARM FRONTAL
PROCESSES WILL BEGIN...AS LOW PRESSURE DEVELOPS OVER THE
MISSISSIPPI VALLEY. THIS WILL INCREASE THE SOUTHERLY FLOW AND
BEGIN A PATTERN OF WARM ADVECTION THAT WILL CONTINUE INTO THE LONG
TERM OF THE FORECAST. INCREASING CONVERGENCE AND MOISTURE
TRANSPORT (ESPECIALLY ALOFT ON TUESDAY NIGHT) WILL RESULT IN
PRECIPITATION CHANCES GRADUALLY INCREASING FROM WEST TO EAST
ACROSS THE CWA...THOUGH MOTION OF SHOWERS WILL BE IN MORE OF A
SSW-TO-NNE DIRECTION. THIS IS ONE PART OF THE FORECAST THAT DOES
COME WITH A BIT OF INCREASING CONFIDENCE. BECAUSE OF
THIS...TEMPERATURE ADJUSTMENTS WERE ALSO REQUIRED FOR BOTH TUESDAY
(SLIGHTLY UPWARD) AND TUESDAY NIGHT (SIGNIFICANTLY UPWARD).
PLENTIFUL CLOUDS AND MOISTURE...COMBINED REASONABLY STRONG FLOW
FOR AN OVERNIGHT PERIOD...SUPPORTS THIS DECISION. THE CURRENT
GRIDS WERE INCREASED BY 5-7 DEGREES...BUT IF SOME OF THE RAW
MODELS ARE TO BE BELIEVED...THIS MAY NOT EVEN BE ENOUGH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN WILL TRANSITION TO A HIGHLY AMPLIFIED REGIME
THROUGH THE EXTENDED PERIOD. THERE CONTINUES TO BE ISSUES WITH
TIMING AND RUN TO RUN CONTINUITY WITH MAJOR SYNOPTIC SYSTEMS TO
AFFECT OUR REGION. LOOKING AT THE VARIOUS OPERATIONAL MODELS...HAVE
DECIDED TO GO WITH A 25 PERCENT 12Z ECMWF AND A 75 PERCENT 12Z GFS.
WE ARE GETTING TO THE POINT IN THE FORECAST WHERE DIURNAL RISE AND
FALL WILL NOT CUT IT WITH FRONTS MOVING THROUGH AND WAVES OF LOW
PRESSURE RIDING ALONG THE FRONTAL BOUNDARY.
ON WEDNESDAY...LONG WAVE TROUGH WILL BE CARVING ITSELF OUT OVER THE
WESTERN U.S. FIRST WEATHER ISSUE IS THE AMOUNT OF ENERGY THAT WILL
EJECT FROM THIS FEATURE ACROSS THE NORTHERN PLAINS AND INTO CENTRAL
CANADA. GFS IS STRONGER AND FASTER WITH THIS ENERGY WHILE THE ECMWF
IS SLOWER...AND THIS HAS BEEN THE CASE OVER THE LAST SVRL RUNS. THIS
WILL HAVE FRONTAL IMPLICATIONS THROUGH OUR REGION WEDNESDAY INTO
THURSDAY. WITH AFOREMENTIONED BLEND...IT ALLOWS FOR A COLD FRONT TO
MOVE THROUGH THE REGION WEDNESDAY NIGHT...BUT NOT AS FAST AS THE GFS
INDICATES. IN ADVANCE OF THE FRONT...WAA SHOWERS ARE FORECAST TO
BREAK OUT AND LIKELY POPS SEEM REASONABLE AT THIS TIME.
FOR THE PERIOD THURSDAY INTO FRIDAY...THIS TIME FRAME IS SHAPING UP
TO BE INCLEMENT AS COLD FRONT SAGS TO OUR SOUTHEAST AND BECOMES
QUASI STATIONARY AS WAVES OF LOW PRESSURE RIDE ALONG IT. THESE WAVES
WILL BRING A SHOT OF FRONTOGENETIC FORCING TO OUR REGION LATE
THURSDAY INTO THURSDAY NIGHT WITH ANOTHER ROUND OF MID TO UPR LVL
FORCING FRIDAY INTO FRIDAY NIGHT. DURING THIS TIME...COLD AIR WILL
SLOWLY SEEP INTO THE REGION FROM THE NORTHWEST. AS SUCH...THERE WILL
BE SOME WINTRY PCPN TYPE ISSUES AS LOW LEVELS COOL BUT AIR ABOVE
WILL BE SLOWER TO COOL. STILL TO EARLY TO GET SPECIFIC GIVEN THE
THERMAL FIELD OSCILLATIONS AT THIS POINT SO JUST HAVE RAIN/SNOW
MENTIONED. LIKELY POPS STILL SEEM REASONABLE FOR MOST OF THE REGION
WITH EACH WAVE RIPPLING BY.
BY FRIDAY NIGHT INTO SATURDAY...COLD ARCTIC HIGH PRESSURE WILL WEDGE
SOUTHEAST INTO OUR AREA. THIS SHOULD PUSH THE PCPN OUT OF THE AREA
BY SATURDAY. THE HIGH WILL SET UP ACROSS THE REGION SATURDAY NIGHT
AND WILL MOVE EAST BY SUNDAY. THIS SHOULD GIVE THE REGION A DRY BUT
COLD PERIOD OF WEATHER.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
WEAK CDFNT CONTINUES TO SETTLE INTO THE REGION THIS EVENING. AREA
OF VFR SC THAT AFFECTED THE TAFS EARLIER TODAY HAS PUSHED E OF THE
NRN TAFS...BUT LINGERS DOWN ACROSS THE SOUTH. THE
MODELS...ESPECIALLY THE GFS...HAVE BEEN TOO PESSIMISTIC IN
FORECASTING MVFR CIGS FOR THIS AFTN. THEREFORE HAD GONE WITH A
MORE OPTIMISTIC FORECAST...BASED ON THE LAST COUPLE OF RUNS OF
THE RAP MODEL. THIS SCENARIO KEEPS THE VFR SC ACROSS THE SRN TAFS
FOR THE FIRST 3 OR 4 HOURS OF THE FORECAST...THEN ALLOWS THEM TO
WORK E. MID LEVEL CLOUDS ASSOCIATED WITH A S/W IN THE ZONAL H5
FLOW THEN PUSH IN BETWEEN 03Z-06Z IN THE W.
KEPT THE MENTION OF MVFR FOG AT SOME OF THE TAFS BETWEEN 09Z-13Z
AS THE LOW LEVELS MOISTENS OVERNIGHT. LATEST SATELLITE LOOP IS
FINALLY SHOWING SOME MVFR CLOUDS DEVELOPING IN NRN INDIANA. WILL
HAVE TO KEEP AN EYE ON THEM AND MIGHT HAVE TO PUT MVFR CIGS BACK
IN THE FORECAST FOR LATER TONIGHT.
COULD SEE SOME REDEVELOPMENT OF THE SC ON MONDAY...ESPECIALLY IN
THE SRN TAFS.
OUTLOOK...SOME MVFR CEILINGS POSSIBLE THROUGH TUESDAY MORNING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE AGAIN WEDNESDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
652 PM PST SUN DEC 1 2013
.SYNOPSIS... A STRONG COLD FRONT TONIGHT TO BRINGS A PERIOD OF RAIN
TO THE PACIFIC NW...WITH RAIN TURNING TO SNOW IN THE CASCADES THROUGH
THE NIGHT AN UPPER LEVEL TROUGH SINKING S OVER THE REGION WILL KEEP A
THREAT FOR SHOWERS GOING THROUGH MON WITH SNOW LEVELS IN THE
FOOTHILLS BY AFTERNOON. A CONTINENTAL COLD FRONT WILL FOLLOW
TUE...BRINGING EVEN COLDER BUT DRIER THAT WILL REMAIN THROUGH THE
REST OF THE WEEK.
&&
UPDATED MARINE SECTION BELOW
.SHORT TERM...SUNDAY THROUGH TUESDAY NIGHT...FOR THE REST OF TODAY
EXPECT WINDS TO INCREASE IN MOST LOCATIONS. WE HAD A FEW GUSTS IN OUR
COAST RANGE RAWS REACH 60 MPH...AND WHILE CERTAINLY NOT
REPRESENTATIVE OF MOST COAST RANGE LOCATIONS...IT IS WINDY. AHEAD OF
THE COLD FRONT THIS EVENING THESE ELEVATIONS 1500-2000 FEET WILL
EASILY DO THIS AGAIN AS HAS STARTED TO OCCUR. LATEST GUIDANCE STILL
KEEPS WINDS UNDER HIGH WIND LEVELS ALONG THE COAST...BUT SOME EXPOSED
SPOTS MAY STILL SEE 50 MPH. LATEST HRRR ALSO KEEPS VALLEY GUSTS
LIMITED TO ABOUT 40 MPH BUT HIGHER EXPOSED HILLS WILL LIKELY DO A
LITTLE BETTER AS THERE IS A VERY STRONG 925 MB WIND FIELD. PEAK WINDS
LOOK TO BE LATE THIS AFTERNOON AND EARLY EVENING.
TRYING TO HONE IN EXACTLY HOW MUCH SNOW WILL FALL AT THE PASSES IS
PROVING TO BE A CHALLENGE. WHILE OUR SNOW ADVISORY CRITERIA IS 6" IN
12 HR...THIS MAY NOT QUITE HAPPEN AT THE PASSES BUT HIGHER ELEVATIONS
SHOULD EASILY BE ABLE TO DO THIS. MODELS APPEAR FAIRLY CONSISTENT IN
SHOWING THE CHANGEOVER TO SNOW AT PASS LEVEL NOT COMING UNTIL LATE
TONIGHT INTO MON MORNING...AFTER THE DEEPER MOISTURE AND HEAVIER
PRECIPITATION HAVE MOVED S...BUT AGREE WITH EARLIER SHIFTS REASONING
THAT SHOWERS CONTINUE ALL DAY MONDAY AS THE SHARP UPPER TROUGH SWINGS
THROUGH IN MOIST OROGRAPHIC FLOW. A SNOW ADVISORY HAS THEREFORE BEEN
ISSUED THE NORTH OREGON AND LANE COUNTY CASCADES TO TAKE INTO ACCOUNT
ADDITIONAL ACCUMULATIONS WITH THE INITIAL ONSET OF MODERATE TO HEAVY
SNOW WHEN THE CHANGEOVER OCCURS. PLUS THERE WILL BE QUITE A BIT OF
BLOWING AND DRIFTING OF SNOW IN EXPOSED LOCATIONS. THE HIGHEST IMPACT
PERIOD WILL BE LATE TONIGHT AND TOMORROW MORNING WHEN THE TRANSITION
OCCURS...BUT WILL RUN THE ADVISORY THROUGH LATE AFTERNOON/EARLY
EVENING TO ACCOUNT FOR CONTINUED SNOW SHOWERS. DID NOT DO AN
ELEVATION BASED HAZARD AS THEY WILL BE FALLING THROUGH THE PERIOD
AND DID NOT WANT TO SEND A MIXED MESSAGE...BUT MORE SIGNIFICANT SNOW
WILL BE AT 4000 FEET AND ABOVE. SNOW LEVELS WILL GET INTO THE COAST
RANGE AND FOOTHILL ELEVATIONS THOUGH GENERALLY LIGHT ACCUMULATIONS
IN SHOWERS WILL BE EXPECTED. SPOTS ABOVE 1500-2000 FEET MAY SNEAK
OUT 3 INCHES IN HEAVIER SHOWERS.
FOR THOSE HOPING FOR MORE THAN A FEW FLAKES AT THE LOWEST ELEVATIONS
MONDAY NIGHT...IT DOES NOT LOOK TOO PROMISING AS WE REMAIN IN
SOUTHERLY FLOW IN THE VALLEY BEFORE THE AIR MASS DRIES AND COOLS
ENOUGH. THE AIR MASS IS COLD ENOUGH OVERNIGHT FOR AT LEAST A MIX OF
RAIN AND SNOW SHOWERS BEFORE THINGS WIND DOWN. THE INTERESTING
DEVELOPMENT IS FOR TUESDAY NIGHT AS THE SECOND ROUND OF COLD AIR
FILTERS IN AND A STRONGER BAROCLINIC ZONE SETS UP BETWEEN THE MILD
OCEAN AND THE COLD CONTINENTAL AIR. BOTH THE NAM/SREF DEPICT SOME
WEAK LIFT MOVING THROUGH. NORTHERLY UPSLOPE FLOW THROUGH THE VALLEY
MAY BE ABLE TO WRING OUT SOME LIGHT SNOW TOWARD EUGENE...BUT THE SREF
IS THE ONLY MODEL SHOWING ENOUGH MOISTURE FOR ANYTHING MORE THAN SOME
FLURRIES...AND EVEN ITS QPF FIELD WILL ONLY RESULT IN A LIGHT DUSTING
IN ANY SHOWERS. MODELS PAINT SLIGHTLY BETTER MOISTURE IN THE CASCADES
WITH THIS WAVE SO NOTHING TO WRITE HOME ABOUT FOR NOW. TUESDAYS HIGHS
STRUGGLE TO MAKE 40 AND LOOK TO BE THE WARMEST HIGHS OF THE WEEK.
/KMD
.LONG TERM...WEDNESDAY THROUGH SATURDAY...WE LOOK TO GET A SECOND
SURGE OF COLDER AIR BEGINNING WEDNESDAY. THE COLDEST GFS ENSEMBLES
AND ECMWF MOS GUIDANCE GIVES VALLEY HIGHS IN THE LOW TO MID
30S...WITH LOWS IN THE MID TO UPPER TEENS TO AROUND 20 FOR WEDNESDAY
WITH BOTH MODELS AGREEING ON THE COLDEST DAY BEING THURSDAY.
UNCERTAINTY IN THE FORECAST FROM A PRECIPITATION PERSPECTIVE GETS
MUCH HIGHER FOR FRIDAY AND BEYOND AS THE GFS BRINGS ANOTHER SURGE OF
COLD AIR BEFORE A MODERATION IN THE AIR MASS SLOWLY OCCURS THROUGH
THE WEEKEND. MEANWHILE THE ECMWF WHICH HAD AN OVERRUNNING LIGHT SNOW
ACROSS THE REGION ON FRIDAY FROM ITS 12Z RUN YESTERDAY...THEN THE
SAME SCENARIO WAS PUSHED BACK TO FRIDAY NIGHT INTO EARLY SATURDAY ON
THE 00Z RUN TODAY...AND NOW THE 12Z RUN SHOWS SOMETHING SIMILAR TO
THESE RUNS BEFORE BRING ANOTHER SHOT OF COLD AIR LATER IN THE
WEEKEND. THE MODELS DO AGREE ON A HIGHLY AMPLIFIED FLOW PATTERN WITH
A LARGE BLOCKING RIDGE OFFSHORE WITH NORTHERLY FLOW OVER THE NW.
WHERE THE DIFFERENCES COME IN IS THAT THERE IS LOW FURTHER OFFSHORE
THAT THE EURO MODEL ATTEMPTS TO SEND MOISTURE UP OVER THE RIDGE INTO
ALASKA THAN BACK DOWN OVER OUR AREA. MEANWHILE THE GFS DOES HAVE A
LOW MOVING THROUGH BUT IT IS NOT NEARLY AS SHARP AND THE NORTHWARD
MOVING MOISTURE IS UNABLE TO SURVIVE THE RETURN TRIP SOUTH.
WILL HOLD OFF ON ANY LARGE SCALE CHANGES AND KEEP THE LOW POP MENTION
IN FOR FRIDAY...BUT THE TEMPERATURE THEME REMAINS THE SAME...AND
EXTENDED PERIOD OF VERY COLD CONDITIONS. /KMD
&&
.AVIATION...LITTLE CHANGE IN CIGS AND VSBY TODAY IN WARM SECTOR
OF APPROACHING FRONT. EXPECT MVFR CIGS INLAND TO HOLD AROUND 2000
FT MSL WITH IFR PERSISTING ALONG THE COAST. WINDY. SURFACE WINDS
SOUTHWESTERLY WITH GUSTS TO 50 KT AT THE COAST...AND GUSTS 35 TO
40 KT POSSIBLE INLAND. WINDS ALOFT AT 4000-5000 FT MSL ARE
WESTERLY AROUND 40 KT THIS MORNING...EXPECTED TO INCREASE UP TO
60 KT THIS AFTERNOON.
KPDX AND APPROACHES...MVFR IN RAIN TODAY. LITTLE CHANGE IN CIGS
THIS AFTERNOON. CIGS LOOK TO RAPIDLY DECREASE AFTER 22Z AS FRONT
MOVES IN...FOR IFR CIGS NEAR 500-800 FT POSSIBLE 22Z-04Z.
SOUTHERLY WINDS WITH GUSTS TO 35 KT. BURGESS
&&
.MARINE UPDATE...GALES HAVE NOT MATERIALIZED THIS AFTERNOON...WITH
BUOYS BARELY SHOWING SMALL CRAFT ADVISORY WINDS...AND HAVE DROPPED
THE GALE WARNING. THE WINDS SHOULD INCREASE LATE TONIGHT INTO
MONDAY...BUT SHOULD REMAIN BELOW 35 KT. HAVE REPLACED THE GALE
WARNING WITH A SMALL CRAFT ADVISORY FOR WINDS. ALSO ISSUED A SMALL
CRAFT ADVISORY FOR HAZARDOUS SEAS DUE TO STEEP SEAS. BREEZY NW WINDS
CONTINUE INTO MONDAY NIGHT BEFORE BUILDING HIGH PRESSURE INLAND
BRINGS A RETURN OF NE WINDS TUESDAY AFTERNOON. THE SEAS WILL SUBSIDE
BELOW 10 FEET LATE TUESDAY EVENING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FOR ALL WATERS THROUGH LATE
MONDAY NIGHT
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FOR ALL WATERS THROUGH
TUESDAY MORNING
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 7 PM
THIS EVENING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 1 AM
MONDAY THROUGH MONDAY EVENING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
310 PM PST SUN DEC 1 2013
.SYNOPSIS... A STRONG COLD FRONT TONIGHT TO BRINGS A PERIOD OF RAIN
TO THE PACIFIC NW...WITH RAIN TURNING TO SNOW IN THE CASCADES THROUGH
THE NIGHT AN UPPER LEVEL TROUGH SINKING S OVER THE REGION WILL KEEP A
THREAT FOR SHOWERS GOING THROUGH MON WITH SNOW LEVELS IN THE
FOOTHILLS BY AFTERNOON. A CONTINENTAL COLD FRONT WILL FOLLOW
TUE...BRINGING EVEN COLDER BUT DRIER THAT WILL REMAIN THROUGH THE
REST OF THE WEEK.
&&
.SHORT TERM...SUNDAY THROUGH TUESDAY NIGHT...FOR THE REST OF TODAY
EXPECT WINDS TO INCREASE IN MOST LOCATIONS. WE HAD A FEW GUSTS IN OUR
COAST RANGE RAWS REACH 60 MPH...AND WHILE CERTAINLY NOT
REPRESENTATIVE OF MOST COAST RANGE LOCATIONS...IT IS WINDY. AHEAD OF
THE COLD FRONT THIS EVENING THESE ELEVATIONS 1500-2000 FEET WILL
EASILY DO THIS AGAIN AS HAS STARTED TO OCCUR. LATEST GUIDANCE STILL
KEEPS WINDS UNDER HIGH WIND LEVELS ALONG THE COAST...BUT SOME EXPOSED
SPOTS MAY STILL SEE 50 MPH. LATEST HRRR ALSO KEEPS VALLEY GUSTS
LIMITED TO ABOUT 40 MPH BUT HIGHER EXPOSED HILLS WILL LIKELY DO A
LITTLE BETTER AS THERE IS A VERY STRONG 925 MB WIND FIELD. PEAK WINDS
LOOK TO BE LATE THIS AFTERNOON AND EARLY EVENING.
TRYING TO HONE IN EXACTLY HOW MUCH SNOW WILL FALL AT THE PASSES IS
PROVING TO BE A CHALLENGE. WHILE OUR SNOW ADVISORY CRITERIA IS 6" IN
12 HR...THIS MAY NOT QUITE HAPPEN AT THE PASSES BUT HIGHER ELEVATIONS
SHOULD EASILY BE ABLE TO DO THIS. MODELS APPEAR FAIRLY CONSISTENT IN
SHOWING THE CHANGEOVER TO SNOW AT PASS LEVEL NOT COMING UNTIL LATE
TONIGHT INTO MON MORNING...AFTER THE DEEPER MOISTURE AND HEAVIER
PRECIPITATION HAVE MOVED S...BUT AGREE WITH EARLIER SHIFTS REASONING
THAT SHOWERS CONTINUE ALL DAY MONDAY AS THE SHARP UPPER TROUGH SWINGS
THROUGH IN MOIST OROGRAPHIC FLOW. A SNOW ADVISORY HAS THEREFORE BEEN
ISSUED THE NORTH OREGON AND LANE COUNTY CASCADES TO TAKE INTO ACCOUNT
ADDITIONAL ACCUMULATIONS WITH THE INITIAL ONSET OF MODERATE TO HEAVY
SNOW WHEN THE CHANGEOVER OCCURS. PLUS THERE WILL BE QUITE A BIT OF
BLOWING AND DRIFTING OF SNOW IN EXPOSED LOCATIONS. THE HIGHEST IMPACT
PERIOD WILL BE LATE TONIGHT AND TOMORROW MORNING WHEN THE TRANSITION
OCCURS...BUT WILL RUN THE ADVISORY THROUGH LATE AFTERNOON/EARLY
EVENING TO ACCOUNT FOR CONTINUED SNOW SHOWERS. DID NOT DO AN
ELEVATION BASED HAZARD AS THEY WILL BE FALLING THROUGH THE PERIOD
AND DID NOT WANT TO SEND A MIXED MESSAGE...BUT MORE SIGNIFICANT SNOW
WILL BE AT 4000 FEET AND ABOVE. SNOW LEVELS WILL GET INTO THE COAST
RANGE AND FOOTHILL ELEVATIONS THOUGH GENERALLY LIGHT ACCUMULATIONS
IN SHOWERS WILL BE EXPECTED. SPOTS ABOVE 1500-2000 FEET MAY SNEAK
OUT 3 INCHES IN HEAVIER SHOWERS.
FOR THOSE HOPING FOR MORE THAN A FEW FLAKES AT THE LOWEST ELEVATIONS
MONDAY NIGHT...IT DOES NOT LOOK TOO PROMISING AS WE REMAIN IN
SOUTHERLY FLOW IN THE VALLEY BEFORE THE AIR MASS DRIES AND COOLS
ENOUGH. THE AIR MASS IS COLD ENOUGH OVERNIGHT FOR AT LEAST A MIX OF
RAIN AND SNOW SHOWERS BEFORE THINGS WIND DOWN. THE INTERESTING
DEVELOPMENT IS FOR TUESDAY NIGHT AS THE SECOND ROUND OF COLD AIR
FILTERS IN AND A STRONGER BAROCLINIC ZONE SETS UP BETWEEN THE MILD
OCEAN AND THE COLD CONTINENTAL AIR. BOTH THE NAM/SREF DEPICT SOME
WEAK LIFT MOVING THROUGH. NORTHERLY UPSLOPE FLOW THROUGH THE VALLEY
MAY BE ABLE TO WRING OUT SOME LIGHT SNOW TOWARD EUGENE...BUT THE SREF
IS THE ONLY MODEL SHOWING ENOUGH MOISTURE FOR ANYTHING MORE THAN SOME
FLURRIES...AND EVEN ITS QPF FIELD WILL ONLY RESULT IN A LIGHT DUSTING
IN ANY SHOWERS. MODELS PAINT SLIGHTLY BETTER MOISTURE IN THE CASCADES
WITH THIS WAVE SO NOTHING TO WRITE HOME ABOUT FOR NOW. TUESDAYS HIGHS
STRUGGLE TO MAKE 40 AND LOOK TO BE THE WARMEST HIGHS OF THE WEEK.
/KMD
.LONG TERM...WEDNESDAY THROUGH SATURDAY...WE LOOK TO GET A SECOND
SURGE OF COLDER AIR BEGINNING WEDNESDAY. THE COLDEST GFS ENSEMBLES
AND ECMWF MOS GUIDANCE GIVES VALLEY HIGHS IN THE LOW TO MID
30S...WITH LOWS IN THE MID TO UPPER TEENS TO AROUND 20 FOR WEDNESDAY
WITH BOTH MODELS AGREEING ON THE COLDEST DAY BEING THURSDAY.
UNCERTAINTY IN THE FORECAST FROM A PRECIPITATION PERSPECTIVE GETS
MUCH HIGHER FOR FRIDAY AND BEYOND AS THE GFS BRINGS ANOTHER SURGE OF
COLD AIR BEFORE A MODERATION IN THE AIR MASS SLOWLY OCCURS THROUGH
THE WEEKEND. MEANWHILE THE ECMWF WHICH HAD AN OVERRUNNING LIGHT SNOW
ACROSS THE REGION ON FRIDAY FROM ITS 12Z RUN YESTERDAY...THEN THE
SAME SCENARIO WAS PUSHED BACK TO FRIDAY NIGHT INTO EARLY SATURDAY ON
THE 00Z RUN TODAY...AND NOW THE 12Z RUN SHOWS SOMETHING SIMILIAR TO
THESE RUNS BEFORE BRING ANOTHER SHOT OF COLD AIR LATER IN THE
WEEKEND. THE MODELS DO AGREE ON A HIGHLY AMPLIFIED FLOW PATTERN WITH
A LARGE BLOCKING RIDGE OFFSHORE WITH NORTHERLY FLOW OVER THE NW.
WHERE THE DIFFERENCES COME IN IS THAT THERE IS LOW FURTHER OFFSHORE
THAT THE EURO MODEL ATTEMPTS TO SEND MOISTURE UP OVER THE RIDGE INTO
ALASKA THAN BACK DOWN OVER OUR AREA. MEANWHILE THE GFS DOES HAVE A
LOW MOVING THROUGH BUT IT IS NOT NEARLY AS SHARP AND THE NORTHWARD
MOVING MOISTURE IS UNABLE TO SURVIVE THE RETURN TRIP SOUTH.
WILL HOLD OFF ON ANY LARGE SCALE CHANGES AND KEEP THE LOW POP MENTION
IN FOR FRIDAY...BUT THE TEMPERATURE THEME REMAINS THE SAME...AND
EXTENDED PERIOD OF VERY COLD CONDITIONS. /KMD
&&
.AVIATION...LITTLE CHANGE IN CIGS AND VSBY TODAY IN WARM SECTOR
OF APPROACHING FRONT. EXPECT MVFR CIGS INLAND TO HOLD AROUND 2000
FT MSL WITH IFR PERSISTING ALONG THE COAST. WINDY. SURFACE WINDS
SOUTHWESTERLY WITH GUSTS TO 50 KT AT THE COAST...AND GUSTS 35 TO
40 KT POSSIBLE INLAND. WINDS ALOFT AT 4000-5000 FT MSL ARE
WESTERLY AROUND 40 KT THIS MORNING...EXPECTED TO INCREASE UP TO
60 KT THIS AFTERNOON.
KPDX AND APPROACHES...MVFR IN RAIN TODAY. LITTLE CHANGE IN CIGS
THIS AFTERNOON. CIGS LOOK TO RAPIDLY DECREASE AFTER 22Z AS FRONT
MOVES IN...FOR IFR CIGS NEAR 500-800 FT POSSIBLE 22Z-04Z.
SOUTHERLY WINDS WITH GUSTS TO 35 KT. BURGESS
&&
.MARINE...FEW UPDATES. PREVIOUS DISCUSSION FOLLOWS. SOUTHERLY
WINDS 20-25 KT WILL PERSIST THIS MORNING AS A WARM FRONT MOVES
ACROSS THE NORTHERN WATERS. STRONGER WINDS WILL MOVE NORTH TO
SOUTH THROUGH THE WATERS TODAY AND MONDAY WITH A POTENT COLD
FRONT. HAVE UPGRADED THE GALE WATCH TO A WARNING FOR THIS EVENING
INTO EARLY MONDAY SINCE MODELS CONTINUE TO SHOW GUSTS NEAR 35 KT.
BREEZY NW WINDS CONTINUE INTO MONDAY NIGHT BEFORE BUILDING HIGH
PRESSURE INLAND BRINGS A RETURN OF NE WINDS TUESDAY AFTERNOON.
A LONG PERIOD SWELL REMAINS IN THE WATERS EARLY THIS MORNING.
BUOYS CURRENTLY SHOW TWO WESTERLY SWELL TRAINS ONE AT 16
SECONDS...AND ONE AT 11 SECONDS. SINCE THESE SWELLS WOULD BE
DIFFICULT TO DISTINGUISH HAVE LEFT THEM COMBINED FOR THE FORECAST.
THE LONGER PERIOD SWELL WILL BECOME DOMINANT THIS AFTERNOON.
HOWEVER THE PERIODS WILL DROP RAPIDLY WITH STEEP (SQUARE) SEAS
LIKELY TONIGHT. THE GALE WARNING TAKES THESE STEEP SEAS INTO
ACCOUNT...WITH OVERALL SEAS PEAKING AROUND 15 FEET LATE TONIGHT.
THE SEAS WILL SUBSIDE BELOW 10 FEET LATE TUESDAY EVENING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS AFTERNOON
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 AM PST MONDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 7 AM
PST MONDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
941 PM CST SUN DEC 1 2013
.UPDATE...
ISSUED AT 941 PM CST SUN DEC 1 2013
INITIAL PRECIPITATION BAND WITH LEADING WAVE WORKING NOW ACROSS
THE SOUTHWEST MINNESOTA PORTION OF THE CWA. BROAD WARM AIR
ADVECTION ALONG WITH APPROACH OF NEXT PV IMPULSE CURRENTLY BACK
ACROSS FAR NORTHWEST SOUTH DAKOTA AND SOUTHWEST NORTH DAKOTA.
CHANNELED ADVECTION WITH THIS FEATURE IS PRIMARILY NORTH OF THE
CWA DURING THE LAST HALF OF THE NIGHT...BUT DOES BRUSH THE FAR
NORTH AND INTO SW MN ON THE SOUTHERN FRINGES. STILL FAIRLY DRY
AT LOW LEVELS BELOW THE MID LEVEL CLOUD BASE...AND HAS KEPT ANY
PRECIPITATION OF NOTE FROM REACHING THE GROUND IN FSD CWA THUS FAR
INTO THE EVENING...AND THIS WILL CONTINUE TO BE A CHALLENGE TO ANY
PRECIPITATION WITH THE SECOND WAVE. HENCE...SEE NO REASON TO
DEVIATE FROM THE VERY LOW POPS FROM EARLIER FORECAST.
WOULD EXPECT BASED ON COMPOSITE OF FORECAST SOUNDINGS ALONG WITH
KABR EVENING GROUND TRUTH...THAT SLEET WOULD LIKELY BE THE FAVORED
PRECIPITATION TYPE WITH THE MID TO LATE EVENING ACTIVITY IN SW MN...
PERHAPS WITH A SHADE OF SNOW IF RATE CAN COME UP ENOUGH TO WET
BULB THE TEMPS DOWN A DEGREE OR SO. FARTHER WEST WITH THE LIFT
ENHANCEMENT APPROACHING WITH THE SECONDARY WAVE...TEMPS ALOFT
CONTINUE TO WARM...AND EVEN THE KABR/KBIS/KUNR RAOBS WOULD START
TO LOOK TOWARD A LIQUID/FREEZING MIX...DEPENDENT ON SURFACE TEMPS
WHICH SHOULD BE SLOW TO MOVE MUCH WITH CLOUDS AGAIN THICKENING
FROM THE WEST. BUT AGAIN...FOR EMPHASIS...PROSPECT OF ANYTHING
MEASURABLE IS QUITE LOW.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 304 PM CST SUN DEC 1 2013
MAIN CONCERN THE NEXT 24 H IS THE SMALL POTENTIAL FOR
PRECIPITATION...PRIMARILY OVER SOUTHWEST MINNESOTA.
ALL MODELS SHOW TWO WAVES MOVING ACROSS THE DAKOTAS AND MINNESOTA
THE NEXT 24 H. THE FIRST WAVE IS ALREADY INTO CENTRAL SD PER WATER
VAPOR IMAGERY AND WILL LIKELY BE INTO SW MN AND NW IA BY 00Z. THERE
ARE FEW ECHOES ASSOCIATED WITH THIS SYSTEM AND THOSE ARE PRIMARILY
ACROSS FAR NORTHERN SOUTH DAKOTA. WITH VERY DRY AIR BELOW 10000 FT
AND BEST FORCING FOR ASCENT IN NORTHERN SD...HAVE REMOVED ANY CHANCE OF
PRECIPITATION WITH THIS WAVE. CLOSE ON ITS HEELS THOUGH IS A SECOND
WAVE. THE NAM IS FASTER AND FARTHER NORTH THAN EITHER THE RAP OR GFS
WITH THIS WAVE. CURRENT TRAJECTORY FROM WATER VAPOR FAVORS THE GFS
AND RAP AND FOLLOWED FOR LATER TONIGHT. THIS PUTS SAME STRONG
PRESSURE ADVECTION ON THE 1.5 PV SURFACE OVER THE CWA BY MIDNIGHT AND
CONTINUING THROUGH SUNRISE. AGAIN...MOISTURE IS A BIG ISSUE AS ALL
MODELS SHOW A 5000 TO 10000 FT DRY LAYER ABOVE THE SURFACE. FOR MUCH
OF SE SD AND NW IA...THIS DRY AIR EXPECTED TO EVAPORATE ANY
PRECIPITATION THAT DOES REACH THE SURFACE. THE ONLY PLACE THE DRY
AIR MAY BE OVERCOME IS IN SW MN WHERE IT MAY INTERACT WITH THE 850
MB BOUNDARY AND ENHANCE THE LIFT AND SATURATION. WHILE THE DRY AIR
LIKELY WILL LIMIT PRECIPITATION EVEN THERE...DID KEEP A SLIGHT CHANCE OF
PRECIPITATION FROM LATE EVENING THROUGH 12Z IN SW MN. TEMPERATURES
ALOFT ARE WELL ABOVE FREEZING...EVEN THE WET BULB TEMPERATURE WILL
BE ABOVE ZERO AND SHOULD MELT ANY PRECIPITATION ALOFT. TEMPERATURES
AT THE SURFACE THIS EVENING EXPECTED TO DROP TO AROUND 30 AND THEN
STEADY OUT AS CLOUDS AND SOUTH WINDS INCREASE. WHILE THERE IS A
POSSIBILITY TEMPERATURES COULD RISE ABOVE FREEZING AS ANY
PRECIPITATION MOVES IN...BELIEVE IT IS MOST LIKELY TO STAY JUST
BELOW FREEZING MOST OF THE NIGHT. SO ANY PRECIPITATION WILL LIKELY
BE A MIX OF FREEZING RAIN AND SLEET. AMOUNTS WILL BE LIGHT...A TRACE
TO A COUPLE HUNDREDTHS...BUT ENOUGH THAT IT COULD SLICK UP ROADS
SHOULD IT FALL.
OTHERWISE...THE PRECIPITATION WILL MOVE OFF BY MONDAY MORNING. THERE
WILL BE A LOT OF CLOUDS AROUND...ESPECIALLY EAST OF THE JAMES RIVER.
IT WILL ALSO BE VERY WARM ALOFT WITH +10C AT 925 MB IN SOUTH CENTRAL
SD WHERE THERE WILL ALSO BE SOME SUN. THEREFORE...EXPECT HIGHS TO
WARM INTO THE LOWER TO MID 50S IN SOUTH CENTRAL SD...WITH UPPER 40S
POSSIBLE OVER MUCH OF SE SD AND INTO NORTHEAST NEBRASKA AND
NORTHWEST IOWA. THE COLDEST TEMPS WILL BE IN SW MN WHERE CLOUDS WILL
BE AROUND MOST OF THE DAY AND WINDS WILL REMAIN S OR SE. BUT EVEN
THERE HIGHS WILL REACH THE LOWER 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 304 PM CST SUN DEC 1 2013
THERE SEEMS TO BE LITTLE SUPPORT FOR PRECIPITATION MONDAY NIGHT
AHEAD OF THE APPROACHING LOW AND COLD FRONT. WITH SOME MID LEVEL
MOISTURE LIKELY TO BE PRESENT...HAVE GONE WITH JUST A SLIGHT
CHANCE OF LIGHT RAIN/FREEZING RAIN FOR LATE MONDAY NIGHT...THAT IS
AFTER MIDNIGHT/06Z. THIS IDEA CONTINUES INTO TUESDAY AS THE LOW
AND FRONT MOVES INTO THE AREA. THE GFS...EC...AND GEM/CANADIAN ARE
FAIRLY CLOSE TO EACH OTHER ON THE PATH AND MOVEMENT OF THE
LOW/FRONT AS IT ENTERS THE AREA AND ARE ACCEPTED OVER THE
NAM...WHICH SEEMS TO BE TOO FAST AND TOO FAR NORTH. EITHER
WAY...ANY STEADY OR WIDESPREAD PRECIPITATION SHOULD STAY NORTH OF
THE AREA...AND AM GOING FOR ONLY A CHANCE OF LIGHT
PRECIPITATION...WITH THE CHANCE INCREASING SLOWLY FROM THE
NORTHWEST IN THE INCOMING COLD AIR. AHEAD OF THE COLD AIR THE
SLIGHT PRECIPITATION THREAT WILL BE LIGHT RAIN/SNOW OR JUST LIGHT
RAIN...AND OF COURSE AS THE COLD AIR ARRIVES THE CHANCE WILL BE
FOR JUST LIGHT SNOW. THIS COOLING SHOULD BE COMPLETE BY EARLY
TUESDAY EVENING...AGAIN SHOWER THAN THE NAM WOULD SUGGEST.
TEMPERATURES...QUITE MILD MONDAY NIGHT...WILL RISE JUST A LITTLE
FAR NORTHWEST...TO A FEW DEGREES SOUTHEAST...BEFORE THE COLDER AIR
TURNS THEM STEADY THEN FALLING. EVEN BY THE SLOWER GFS AND
EC...THE COLD INVASION WILL BECOME WELL ESTABLISHED BY TUESDAY
EVENING. WILL CONTINUE THE CHANCES OF LIGHT SNOW THROUGH
WEDNESDAY AND OF A FEW FLURRIES INTO THURSDAY. LACK OF SUPPORT
DOOMS ACCUMULATIONS...IF ANY...TO BE QUITE LIGHT. FRIDAY AND
SATURDAY LOOK DRY AND COLD.
THE COLD AIR WILL BE QUITE BITING WITH WIND CHILLS CURRENTLY
EXPECTED TO DROP TO BELOW ZERO FAR WEST BY WEDNESDAY MORNING. BY
THURSDAY MORNING THE WHOLE AREA SHOULD BE BELOW ZERO AND THE NORTH
PERHAPS GETTING CLOSE TO THE ADVISORY BOUNDARY OF 20 BELOW ZERO.
TEMPERATURES AND WIND CHILLS WILL BE PARTLY DEPENDENT ON WHETHER
OR NOT WE GET ANY SNOW COVER...EVEN A HALF INCH TO INCH WILL HAVE
AN EFFECT. WHAT WE WILL HAVE IN THE FORECAST COULD BE A LITTLE
COLDER OR LESS COLD DEPENDING ON THAT FACTOR.
AM GOING WITH THE EXTENDED GUIDANCE INDICATING A LOW CHANCE OF
SNOW FOR DAY 7...NEXT SUNDAY. THE EC IS THE ONLY MODEL INDICATING
ANYTHING...BUT AS FAR WEST AS IT KEEPS THE UPPER TROUGH...GOING BY
IT ALONE WOULD RATE A BIGGER THREAT...SO SLIGHT CHANCE SEEMS THE
BEST ROAD FOR NOW. THERE WILL BE SOME SLIGHT MODERATION IN THE
COLD TEMPERATURES...BUT ONLY SLIGHT AS THE COLD REGIME WILL
DOMINATE FOR A WHILE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 941 PM CST SUN DEC 1 2013
WEAKER LEAD WAVE MOVING THROUGH MINNESOTA AND IOWA...WITH
SECONDARY SYSTEM RACING INTO NORTHWEST SOUTH DAKOTA. LIFT FORCING
WITH SECONDARY WAVE LOOKS TO REMAIN MAINLY NORTH AND EAST OF THE
TAF SITES...WITH POTENTIAL FOR PERHAPS A LITTLE LIGHT FREEZING
RAIN OR RAIN NEAR THE KHON SITE AROUND 07Z-11Z WINDOW.
HOWEVER...NOT WORTH A MENTION WITH VERY LOW PROBABILITY EVENT AT
THIS TIME. EVEN WITH A BIT BETTER THREAT OF PRECIPITATION TOWARD
SW MN...CONDITIONS ARE LIKELY TO REMAIN VFR EVEN IN ANY
PRECIPITATION...GREATER THAN 6 SM AND CEILINGS ABOVE 3000 FT AGL.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...SCHUMACHER
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
555 PM CST SUN DEC 1 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 304 PM CST SUN DEC 1 2013
MAIN CONCERN THE NEXT 24 H IS THE SMALL POTENTIAL FOR
PRECIPITATION...PRIMARILY OVER SOUTHWEST MINNESOTA.
ALL MODELS SHOW TWO WAVES MOVING ACROSS THE DAKOTAS AND MINNESOTA
THE NEXT 24 H. THE FIRST WAVE IS ALREADY INTO CENTRAL SD PER WATER
VAPOR IMAGERY AND WILL LIKELY BE INTO SW MN AND NW IA BY 00Z. THERE
ARE FEW ECHOES ASSOCIATED WITH THIS SYSTEM AND THOSE ARE PRIMARILY
ACROSS FAR NORTHERN SOUTH DAKOTA. WITH VERY DRY AIR BELOW 10000 FT
AND BEST FORCING FOR ASCENT IN NORTHERN SD...HAVE REMOVED ANY CHANCE OF
PRECIPITATION WITH THIS WAVE. CLOSE ON ITS HEELS THOUGH IS A SECOND
WAVE. THE NAM IS FASTER AND FARTHER NORTH THAN EITHER THE RAP OR GFS
WITH THIS WAVE. CURRENT TRAJECTORY FROM WATER VAPOR FAVORS THE GFS
AND RAP AND FOLLOWED FOR LATER TONIGHT. THIS PUTS SAME STRONG
PRESSURE ADVECTION ON THE 1.5 PV SURFACE OVER THE CWA BY MIDNIGHT AND
CONTINUING THROUGH SUNRISE. AGAIN...MOISTURE IS A BIG ISSUE AS ALL
MODELS SHOW A 5000 TO 10000 FT DRY LAYER ABOVE THE SURFACE. FOR MUCH
OF SE SD AND NW IA...THIS DRY AIR EXPECTED TO EVAPORATE ANY
PRECIPITATION THAT DOES REACH THE SURFACE. THE ONLY PLACE THE DRY
AIR MAY BE OVERCOME IS IN SW MN WHERE IT MAY INTERACT WITH THE 850
MB BOUNDARY AND ENHANCE THE LIFT AND SATURATION. WHILE THE DRY AIR
LIKELY WILL LIMIT PRECIPITATION EVEN THERE...DID KEEP A SLIGHT CHANCE OF
PRECIPITATION FROM LATE EVENING THROUGH 12Z IN SW MN. TEMPERATURES
ALOFT ARE WELL ABOVE FREEZING...EVEN THE WET BULB TEMPERATURE WILL
BE ABOVE ZERO AND SHOULD MELT ANY PRECIPITATION ALOFT. TEMPERATURES
AT THE SURFACE THIS EVENING EXPECTED TO DROP TO AROUND 30 AND THEN
STEADY OUT AS CLOUDS AND SOUTH WINDS INCREASE. WHILE THERE IS A
POSSIBILITY TEMPERATURES COULD RISE ABOVE FREEZING AS ANY
PRECIPITATION MOVES IN...BELIEVE IT IS MOST LIKELY TO STAY JUST
BELOW FREEZING MOST OF THE NIGHT. SO ANY PRECIPITATION WILL LIKELY
BE A MIX OF FREEZING RAIN AND SLEET. AMOUNTS WILL BE LIGHT...A TRACE
TO A COUPLE HUNDREDTHS...BUT ENOUGH THAT IT COULD SLICK UP ROADS
SHOULD IT FALL.
OTHERWISE...THE PRECIPITATION WILL MOVE OFF BY MONDAY MORNING. THERE
WILL BE A LOT OF CLOUDS AROUND...ESPECIALLY EAST OF THE JAMES RIVER.
IT WILL ALSO BE VERY WARM ALOFT WITH +10C AT 925 MB IN SOUTH CENTRAL
SD WHERE THERE WILL ALSO BE SOME SUN. THEREFORE...EXPECT HIGHS TO
WARM INTO THE LOWER TO MID 50S IN SOUTH CENTRAL SD...WITH UPPER 40S
POSSIBLE OVER MUCH OF SE SD AND INTO NORTHEAST NEBRASKA AND
NORTHWEST IOWA. THE COLDEST TEMPS WILL BE IN SW MN WHERE CLOUDS WILL
BE AROUND MOST OF THE DAY AND WINDS WILL REMAIN S OR SE. BUT EVEN
THERE HIGHS WILL REACH THE LOWER 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 304 PM CST SUN DEC 1 2013
THERE SEEMS TO BE LITTLE SUPPORT FOR PRECIPITATION MONDAY NIGHT
AHEAD OF THE APPROACHING LOW AND COLD FRONT. WITH SOME MID LEVEL
MOISTURE LIKELY TO BE PRESENT...HAVE GONE WITH JUST A SLIGHT
CHANCE OF LIGHT RAIN/FREEZING RAIN FOR LATE MONDAY NIGHT...THAT IS
AFTER MIDNIGHT/06Z. THIS IDEA CONTINUES INTO TUESDAY AS THE LOW
AND FRONT MOVES INTO THE AREA. THE GFS...EC...AND GEM/CANADIAN ARE
FAIRLY CLOSE TO EACH OTHER ON THE PATH AND MOVEMENT OF THE
LOW/FRONT AS IT ENTERS THE AREA AND ARE ACCEPTED OVER THE
NAM...WHICH SEEMS TO BE TOO FAST AND TOO FAR NORTH. EITHER
WAY...ANY STEADY OR WIDESPREAD PRECIPITATION SHOULD STAY NORTH OF
THE AREA...AND AM GOING FOR ONLY A CHANCE OF LIGHT
PRECIPITATION...WITH THE CHANCE INCREASING SLOWLY FROM THE
NORTHWEST IN THE INCOMING COLD AIR. AHEAD OF THE COLD AIR THE
SLIGHT PRECIPITATION THREAT WILL BE LIGHT RAIN/SNOW OR JUST LIGHT
RAIN...AND OF COURSE AS THE COLD AIR ARRIVES THE CHANCE WILL BE
FOR JUST LIGHT SNOW. THIS COOLING SHOULD BE COMPLETE BY EARLY
TUESDAY EVENING...AGAIN SHOWER THAN THE NAM WOULD SUGGEST.
TEMPERATURES...QUITE MILD MONDAY NIGHT...WILL RISE JUST A LITTLE
FAR NORTHWEST...TO A FEW DEGREES SOUTHEAST...BEFORE THE COLDER AIR
TURNS THEM STEADY THEN FALLING. EVEN BY THE SLOWER GFS AND
EC...THE COLD INVASION WILL BECOME WELL ESTABLISHED BY TUESDAY
EVENING. WILL CONTINUE THE CHANCES OF LIGHT SNOW THROUGH
WEDNESDAY AND OF A FEW FLURRIES INTO THURSDAY. LACK OF SUPPORT
DOOMS ACCUMULATIONS...IF ANY...TO BE QUITE LIGHT. FRIDAY AND
SATURDAY LOOK DRY AND COLD.
THE COLD AIR WILL BE QUITE BITING WITH WIND CHILLS CURRENTLY
EXPECTED TO DROP TO BELOW ZERO FAR WEST BY WEDNESDAY MORNING. BY
THURSDAY MORNING THE WHOLE AREA SHOULD BE BELOW ZERO AND THE NORTH
PERHAPS GETTING CLOSE TO THE ADVISORY BOUNDARY OF 20 BELOW ZERO.
TEMPERATURES AND WIND CHILLS WILL BE PARTLY DEPENDENT ON WHETHER
OR NOT WE GET ANY SNOW COVER...EVEN A HALF INCH TO INCH WILL HAVE
AN EFFECT. WHAT WE WILL HAVE IN THE FORECAST COULD BE A LITTLE
COLDER OR LESS COLD DEPENDING ON THAT FACTOR.
AM GOING WITH THE EXTENDED GUIDANCE INDICATING A LOW CHANCE OF
SNOW FOR DAY 7...NEXT SUNDAY. THE EC IS THE ONLY MODEL INDICATING
ANYTHING...BUT AS FAR WEST AS IT KEEPS THE UPPER TROUGH...GOING BY
IT ALONE WOULD RATE A BIGGER THREAT...SO SLIGHT CHANCE SEEMS THE
BEST ROAD FOR NOW. THERE WILL BE SOME SLIGHT MODERATION IN THE
COLD TEMPERATURES...BUT ONLY SLIGHT AS THE COLD REGIME WILL
DOMINATE FOR A WHILE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 555 PM CST SUN DEC 1 2013
WEAKER LEAD WAVE MOVING INTO MINNESOTA AND IOWA...WITH SECONDARY
SYSTEM RACING ACROSS NORTHERN ROCKIES. HOWEVER...LIFT FORCING FOR
SECONDARY WAVE LOOKS TO REMAIN MAINLY NORTH AND EAST OF THE TAF
SITES...WITH POTENTIAL FOR PERHAPS A LITTLE LIGHT FREEZING RAIN OR
RAIN NEAR THE KHON SITE AROUND 09Z-13Z WINDOW. HOWEVER...NOT WORTH
A MENTION WITH VERY LOW PROBABILITY EVENT AT THIS TIME. EVEN IF
WITH THE BETTER THREAT OF PRECIPITATION TOWARD SW MN...CONDITIONS
ARE LIKELY TO REMAIN VFR EVEN IN ANY PRECIPITATION...GREATER THAN
6 SM AND CEILINGS ABOVE 3000 FT AGL.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...SCHUMACHER
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1123 AM CST SAT NOV 30 2013
.UPDATE...
UPDATE TO 18Z AVIATION DISCUSSION BELOW.
NO MAJOR CHANGES MADE TO THE FORECAST THIS MORNING. CURRENT RADAR
IMAGES SHOW SOME WEAK ECHOES PUSHING OVER THE NORTHWESTERN CWA AT
THIS TIME...SO WILL STICK WITH A SCHC POP IN THAT AREA...WITH
LITTLE IN THE WAY OF RAINFALL ACCUMULATION EXPECTED. NO CHANGES
MADE TO WINDS OR TEMPERATURES AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
CHANCES FOR PRECIPITATION AS WELL AS P-TYPE WILL BE THE FORECAST
CHALLENGES.
A WEAK MID LEVEL SHORT WAVE CURRENTLY OVER MONTANA WILL TRACK
SOUTHEASTWARD ACROSS THE REGION TODAY...BRINGING PARTLY CLOUDY
SKIES TO THE CWA. THE PAST FEW RUNS OF THE RUC AND THE NSSL WRF
BOTH SHOW SOME LIGHT RAIN FOR THE FAR NW PORTION OF THE
CWA...PERHAPS REACHING KMBG BY THIS AFTERNOON. THUS HAVE ADDED A
LOW POP.
ANOTHER MID LEVEL SHORT WAVE AND FRONTAL BOUNDARY WILL TRACK
ACROSS THE REGION ON SUNDAY. MODELS HAVE SIGNIFICANTLY SLOWED DOWN
THE PROGRESSION OF THE TROUGH...WITH PCPN NOT REACHING THE JAMES
RIVER VALLEY UNTIL AFTER 18Z. IT STILL APPEARS AS THOUGH THE
LEADING EDGE OF THE PCPN WILL FALL AS ALL SNOW. HOWEVER WITH WAA
QUICKLY PUSHING IN ON THE BACK SIDE...THE SNOW WILL TRANSITION
OVER TO ALL RAIN. THIS SYSTEM DOES NOT CONTAIN A GREAT DEAL OF LOW
LEVEL MOISTURE SO WILL MAINTAIN CHC POP ALONG THE ND/SD BORDER FOR
NOW. A MUCH STRONGER STORM SYSTEM WILL BEGIN IMPACTING THE REGION
ON MONDAY. HOWEVER MODELS ARE NOT IN A REAL GOOD AGREEMENT WITH THE
OVERALL PLACEMENT OF THIS MID LEVEL CLOSED LOW...WHICH LEADS TO A
LOW FORECASTER CONFIDENCE. EVEN WITH A DISAGREEMENT ON THE PLACEMENT
THERE IS A GENERAL CONSENSUS THAT TEMPERATURES WILL BE WARM ENOUGH
TO SUPPORT A MOSTLY RAIN EVENT.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
STILL NOT A LOT OF CONFIDENCE WITH THE FINER DETAILS WITHIN THE
EXTENDED...THOUGH TWO GENERAL TRENDS CAN BE EXPECTED. THE FIRST
WILL BE THE INFLUENCE OF A BROAD UPPER TROF AND EMBEDDED
SHORTWAVES MOVING ACROSS THE NORTHERN TIER CONUS. MOST OF THE
PRECIPITATION WILL BE ASSOCIATED WITH AN H7 LOW THAT LOOKS TO
TRACK ACROSS NORTH DAKOTA/MINNESOTA...THOUGH IT MAY PIVOT THROUGH
WESTERN SOUTH DAKOTA DEPENDING ON THE MODEL. THIS TRACK SUGGESTS
NORTH DAKOTA WILL RECEIVE THE MAJORITY OF PRECIPITATION WITHIN THE
WARM ADVECTION BAND AND ANY TROWAL BASED WRAP AROUND. THE GFS IS
GENERALLY WEAKER WITH SIGNIFICANTLY LOWER PRECIPITATION POTENTIAL.
THE ECMWF IS STRONGER...WITH A MORE SOUTHERLY TRACK...AND STRONGER
WINDS WITH POTENTIALLY MORE IMPACTS TO THE CWA.
THE SECOND FEATURE WILL BE ANOMALOUSLY COLD AIR POURING INTO THE
REGION. TIMING DIFFERENCES CONTINUE BETWEEN THE GFS AND
ECMWF...VARYING BETWEEN TUESDAY AND WEDNESDAY RESPECTIVELY. BOTH
MODELS RESOLVE THE COLD POOL WITH SIMILAR INTENSITY AND
DURATION...AS IT WILL COME TO DOMINATE THE WEATHER THROUGH THE END
OF THE WORK WEEK.
UNFORTUNATELY...BOTH MODELS HAVE BEEN REASONABLY CONSISTENT WITH
THEIR INDIVIDUAL TRENDS. WILL CONTINUE TO BROADBRUSH THE FIRST FEW
PERIODS OF THE EXTENDED WITH CHANCE POPS/SNOW UNTIL MODELS ENTER
BETTER ALIGNMENT.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS EXPECTED AT ALL TERMINALS WITH WINDS UNDER 10 KTS.
A MID LEVEL CLOUD DECK WILL MOVE ACROSS THE AREA TODAY AND
OVERNIGHT AOA 5 KFT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...PARKIN
SHORT TERM...SD
LONG TERM...CONNELLY
AVIATION...SCARLETT
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1116 AM CST SAT NOV 30 2013
.UPDATE...
ISSUED AT 1116 AM CST SAT NOV 30 2013
TEMPERATURES WARMING EVEN FASTER THAN FORECAST AND CURRENTLY 5 TO
10 DEGREES WARMER THAN RAP AND NAM. WHILE STRONG INVERSION WILL
EVENTUALLY SLOW THE RISE...EXPECT THAT AREAS ALONG AND SOUTH OF
I90 WILL MIX TO AROUND 900 MB. THIS FAVORS TEMPERATURES CLOSE TO
50 ALONG I-90 AND INTO THE LOWER 50S IN THE MISSOURI VALLEY AND
PORTIONS OF NORTHWEST IOWA. DESPITE THE WARMER TEMPERATURES...
WINDS WILL NOT BE MUCH STRONGER...10 MPH OR LESS IN MOST AREAS.
DID NOT WARM QUITE AS MUCH ALONG HWY 14 IN EAST CENTRAL SD AND SW
MN DUE TO MORE CLOUDS THIS AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SAT NOV 30 2013
A MILD AND MUCH LESS WINDY DAY TODAY AS A WEAK BOUNDARY MOVES INTO
THE AREA. WHILE THE LOWER AND MID LEVEL THERMAL FIELD WILL BE A
LITTLE COOLER THAN YESTERDAY BETTER MIXING SHOULD SUPPORT WARMER
READINGS. WITH QUITE A FEW 50S TO THE WEST YESTERDAY AND THAT AIR
MASS MOVING INTO THE AREA WILL GO AHEAD AND RAISE IN MOST
LOCATIONS...ESPECIALLY WITH THE THOUGHT THAT CLOUD COVER WILL BE A
LITTLE LESS THROUGH MID AFTERNOON THAN PREVIOUSLY THOUGHT. DO EXPECT
SOME MID LEVEL CLOUDS TO REACH THE HIGHWAY 14 CORRIDOR BY ABOUT MID
DAY BUT THE INTERSTATE 90 CORRIDOR AND POINTS SOUTH SHOULD HOLD OFF
UNTIL AT LEAST MID AFTERNOON. FULL MIXING TO 900MB OR SO IN THE
SOUTHERN CWA SUPPORT ABOUT 52 TO 53 SO FOR NOW WILL GO ABOUT 50 IN
THIS AREA WHICH LEAVES A BIT OF WIGGLE ROOM IN CASE MIXING IS NOT
QUITE AS GOOD AS EXPECTED BUT WITH NO SNOW COVER SUSPECT THAT IT
WILL BE. THE REST OF THE AREA SHOULD BE MAINLY MID TO UPPER 40S WITH
SOME LOWER 40S ALONG THE HIGHWAY 14 CORRIDOR WHERE CLOUDS MOVE IN
QUICKER.
SHOULD BE FAIRLY MILD OVERNIGHT ALTHOUGH IT WILL BE A BATTLE BETWEEN
LIGHT WINDS...NO SNOW COVER AND SOME CLOUD COVER. WILL GO WITH
MAINLY UPPER TEENS TO LOWER 20S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 345 AM CST SAT NOV 30 2013
RELATIVELY QUIET WEATHER PATTERN CONTINUES INTO SUNDAY WITH LARGE
TROUGH BECOMING BETTER ORGANIZED OVER THE WEST COAST AND SURFACE
HIGH PRESSURE DOMINATING ACROSS THE EASTERN TWO THIRDS OF THE
COUNTRY. MODELS SHOW A FAIR AMOUNT OF MID AND HIGH LEVEL CLOUDS
STREAMING INTO THE FORECAST AREA. THERE IS EVEN SOME WEAK LIFT THAT
DEVELOPS ACROSS THE NORTHERN EDGE OF THE FORECAST AREA AS A WEAK
INITIAL WAVE PASSES BY...BUT THE LOWEST 4-5K FEET REMAIN UNSATURATED
MAKING IT TOUGH FOR THE PRECIPITATION TO REACH THE SURFACE. HAVE A
SLIGHT CHANCE OF RAIN OR SNOW IN THE LATE AFTERNOON HOURS ALONG THE
HIGHWAY 14 CORRIDOR...BUT OTHERWISE EXPECT DRY CONDITIONS TO
PREVAIL.
THROUGH THE EVENING HOURS SOUNDINGS WET BULB DOWN TO SNOW FAIRLY
QUICK AS ANOTHER WEAK WAVE PASSES TO THE NORTH. COULD SEE SOME
LIGHT SNOW WITH THIS WAVE ACROSS THE NORTHEAST HALF OF THE FORECAST
AREA SUNDAY NIGHT...BUT ANYTHING THAT FALLS WILL BE VERY LIGHT.
MONDAY APPEARS TO BE DRY AND SOMEWHAT MILD AS WARM FRONT PIVOTS
THROUGH THE REGION RESULTING IN A FAIR AMOUNT OF WARMING. 925 HPA
TEMPS WARM WELL INTO THE SINGLE DIGITS ABOVE FREEZING...AND HAVE
RAISED FORECAST HIGHS WITH GREATEST FOCUS FOR WARMING WEST OF THE
JAMES RIVER VALLEY. SOUTHERLY WINDS SHOULD AID IN THE
WARMING...WHILE A FAIR AMOUNT OF CLOUD COVER IS EXPECTED AS SURFACE
LOW WORKS IN NORTH DAKOTA.
MODEL AGREEMENT REALLY STARTS TO DISINTEGRATE THEREAFTER WITH GFS
OFFERING A MORE PROGRESSIVE EVOLUTION OF THE LOW THAN THE ECMWF.
WITH MODELS INDICATING A FAIRLY SIGNIFICANT CYCLONE AND JET ENERGY
HANGING BACK ON THE WEST SIDE OF THE TROUGH THROUGH AT LEAST MID DAY
TUESDAY...HAVE SIDED TOWARDS THE SLOWER EVOLUTION OF THIS SYSTEM.
CONTINUED MENTION OF MID RANGE POPS MONDAY NIGHT - TUESDAY WITH
INCREASE IN POPS ON WEDNESDAY. OVERALL...APPEARS AS THOUGH MUCH OF
THE MID AND UPPER LEVEL FORCING REMAINS TO THE NORTH AND WEST. IF
WE WERE ABLE TO GET PRECIP HERE...WOULD BE A TOUGH CALL BUT APPEARS
TO BE SOME SORT OF MIXTURE TO THE SOUTH WITH SNOW DOMINANTLY FALLING
ACROSS THE NORTH AND WEST.
MODELS SHOW FALLING TEMPERATURES ON WEDNESDAY THROUGH THE REMAINDER
OF THE EXTENDED AS INVERTED TROUGH SHIFTS THROUGH WITH MUCH COOLER
AIR POURING INTO THE NORTHERN PLAINS. HAVE SQUASHED THE DIURNAL
RANGE ON WEDNESDAY ACROSS THE WEST...WITH LESS MANIPULATION FURTHER
TO THE SOUTH AND EAST. HAVE ALSO LOWERED FORECAST HIGHS ON THURSDAY
WITH -15 TO -17 DEGREE AIR ACROSS THE FORECAST AREA AT 925 HPA.
HAVE ALSO RAISED WINDS CLOSER TO MOS VALUES UNDER THE INFLUENCE OF
STRONG COLD AIR ADVECTION. AT THIS POINT...DID NOT GO STRONGLY
COOL...AS LIMITED SNOW COVER MAY AID IN SOME MIXING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1116 AM CST SAT NOV 30 2013
LIGHT WINDS AND VFR CLOUDS AND CIGS EXPECTED THROUGH 18Z AT TAF
LOCATIONS...KFSD...KSUX AND KHON. CIGS WILL BE LOWERING OVERNIGHT
AND INTO SUNDAY MORNING ACROSS SE SD AS WARM FRONT APPROACHES BUT
WITH VERY DRY LOW LEVEL AIR MASS DO NOT EXPECT PRECIPITATION TO
DEVELOP. HOWEVER...CIGS COULD FALL TO AS LOW AS 4000 FT ON SUNDAY
MORNING. OTHER CONCERN IS STRATUS IN THE RED RIVER VALLEY OF ND
AND NW MN. LOW LEVEL TRAJECTORIES BRING THESE CLOUDS INTO THE
MINNESOTA RIVER VALLEY THIS EVENING AND MAY RESULT IN MVFR CIGS AS
FAR WEST AS KMML AND KMWM THIS EVENING BEFORE CLOUDS BEGIN TO MOVE
EAST TOWARD SUNRISE. WINDS THROUGH THE PERIOD WILL BE LESS THAN 10
KTS...FROM THE NORTHWEST THIS AFTERNOON AND EVENING...AND FROM THE
SOUTHEAST ON SUNDAY MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...SCHUMACHER
SHORT TERM...08
LONG TERM...
AVIATION...SCHUMACHER
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1021 AM CST SAT NOV 30 2013
.UPDATE...
NO MAJOR CHANGES MADE TO THE FORECAST THIS MORNING. CURRENT RADAR
IMAGES SHOW SOME WEAK ECHOES PUSHING OVER THE NORTHWESTERN CWA AT
THIS TIME...SO WILL STICK WITH A SCHC POP IN THAT AREA...WITH
LITTLE IN THE WAY OF RAINFALL ACCUMULATION EXPECTED. NO CHANGES
MADE TO WINDS OR TEMPERATURES AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
CHANCES FOR PRECIPITATION AS WELL AS P-TYPE WILL BE THE FORECAST
CHALLENGES.
A WEAK MID LEVEL SHORT WAVE CURRENTLY OVER MONTANA WILL TRACK
SOUTHEASTWARD ACROSS THE REGION TODAY...BRINGING PARTLY CLOUDY
SKIES TO THE CWA. THE PAST FEW RUNS OF THE RUC AND THE NSSL WRF
BOTH SHOW SOME LIGHT RAIN FOR THE FAR NW PORTION OF THE
CWA...PERHAPS REACHING KMBG BY THIS AFTERNOON. THUS HAVE ADDED A
LOW POP.
ANOTHER MID LEVEL SHORT WAVE AND FRONTAL BOUNDARY WILL TRACK
ACROSS THE REGION ON SUNDAY. MODELS HAVE SIGNIFICANTLY SLOWED DOWN
THE PROGRESSION OF THE TROUGH...WITH PCPN NOT REACHING THE JAMES
RIVER VALLEY UNTIL AFTER 18Z. IT STILL APPEARS AS THOUGH THE
LEADING EDGE OF THE PCPN WILL FALL AS ALL SNOW. HOWEVER WITH WAA
QUICKLY PUSHING IN ON THE BACK SIDE...THE SNOW WILL TRANSITION
OVER TO ALL RAIN. THIS SYSTEM DOES NOT CONTAIN A GREAT DEAL OF LOW
LEVEL MOISTURE SO WILL MAINTAIN CHC POP ALONG THE ND/SD BORDER FOR
NOW. A MUCH STRONGER STORM SYSTEM WILL BEGIN IMPACTING THE REGION
ON MONDAY. HOWEVER MODELS ARE NOT IN A REAL GOOD AGREEMENT WITH THE
OVERALL PLACEMENT OF THIS MID LEVEL CLOSED LOW...WHICH LEADS TO A
LOW FORECASTER CONFIDENCE. EVEN WITH A DISAGREEMENT ON THE PLACEMENT
THERE IS A GENERAL CONSENSUS THAT TEMPERATURES WILL BE WARM ENOUGH
TO SUPPORT A MOSTLY RAIN EVENT.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
STILL NOT A LOT OF CONFIDENCE WITH THE FINER DETAILS WITHIN THE
EXTENDED...THOUGH TWO GENERAL TRENDS CAN BE EXPECTED. THE FIRST
WILL BE THE INFLUENCE OF A BROAD UPPER TROF AND EMBEDDED
SHORTWAVES MOVING ACROSS THE NORTHERN TIER CONUS. MOST OF THE
PRECIPITATION WILL BE ASSOCIATED WITH AN H7 LOW THAT LOOKS TO
TRACK ACROSS NORTH DAKOTA/MINNESOTA...THOUGH IT MAY PIVOT THROUGH
WESTERN SOUTH DAKOTA DEPENDING ON THE MODEL. THIS TRACK SUGGESTS
NORTH DAKOTA WILL RECEIVE THE MAJORITY OF PRECIPITATION WITHIN THE
WARM ADVECTION BAND AND ANY TROWAL BASED WRAP AROUND. THE GFS IS
GENERALLY WEAKER WITH SIGNIFICANTLY LOWER PRECIPITATION POTENTIAL.
THE ECMWF IS STRONGER...WITH A MORE SOUTHERLY TRACK...AND STRONGER
WINDS WITH POTENTIALLY MORE IMPACTS TO THE CWA.
THE SECOND FEATURE WILL BE ANOMALOUSLY COLD AIR POURING INTO THE
REGION. TIMING DIFFERENCES CONTINUE BETWEEN THE GFS AND
ECMWF...VARYING BETWEEN TUESDAY AND WEDNESDAY RESPECTIVELY. BOTH
MODELS RESOLVE THE COLD POOL WITH SIMILAR INTENSITY AND
DURATION...AS IT WILL COME TO DOMINATE THE WEATHER THROUGH THE END
OF THE WORK WEEK.
UNFORTUNATELY...BOTH MODELS HAVE BEEN REASONABLY CONSISTENT WITH
THEIR INDIVIDUAL TRENDS. WILL CONTINUE TO BROADBRUSH THE FIRST FEW
PERIODS OF THE EXTENDED WITH CHANCE POPS/SNOW UNTIL MODELS ENTER
BETTER ALIGNMENT.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS EXPECTED AT ALL TERMINALS. LIGHT WINDS WILL BE OUT
OF THE NORTHWEST GRADUALLY SHIFTING TO THE NORTH.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...PARKIN
SHORT TERM...SD
LONG TERM...CONNELLY
AVIATION...CONNELLY
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
543 AM CST SAT NOV 30 2013
.UPDATE...
12Z AVIATION DISCUSSION BELOW...
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
CHANCES FOR PRECIPITATION AS WELL AS P-TYPE WILL BE THE FORECAST
CHALLENGES.
A WEAK MID LEVEL SHORT WAVE CURRENTLY OVER MONTANA WILL TRACK
SOUTHEASTWARD ACROSS THE REGION TODAY...BRINGING PARTLY CLOUDY
SKIES TO THE CWA. THE PAST FEW RUNS OF THE RUC AND THE NSSL WRF
BOTH SHOW SOME LIGHT RAIN FOR THE FAR NW PORTION OF THE
CWA...PERHAPS REACHING KMBG BY THIS AFTERNOON. THUS HAVE ADDED A
LOW POP.
ANOTHER MID LEVEL SHORT WAVE AND FRONTAL BOUNDARY WILL TRACK
ACROSS THE REGION ON SUNDAY. MODELS HAVE SIGNIFICANTLY SLOWED DOWN
THE PROGRESSION OF THE TROUGH...WITH PCPN NOT REACHING THE JAMES
RIVER VALLEY UNTIL AFTER 18Z. IT STILL APPEARS AS THOUGH THE
LEADING EDGE OF THE PCPN WILL FALL AS ALL SNOW. HOWEVER WITH WAA
QUICKLY PUSHING IN ON THE BACK SIDE...THE SNOW WILL TRANSITION
OVER TO ALL RAIN. THIS SYSTEM DOES NOT CONTAIN A GREAT DEAL OF LOW
LEVEL MOISTURE SO WILL MAINTAIN CHC POP ALONG THE ND/SD BORDER FOR
NOW. A MUCH STRONGER STORM SYSTEM WILL BEGIN IMPACTING THE REGION
ON MONDAY. HOWEVER MODEL ARE NOT IN A REAL GOOD AGREEMENT WITH THE
OVERALL PLACEMENT OF THIS MID LEVEL CLOSED LOW...WHICH LEADS TO A
LOW FORECASTER CONFIDENCE. EVEN WITH A DISAGREEMENT ON THE PLACEMENT
THERE IS A GENERAL CONSENSUS THAT TEMPERATURES WILL BE WARM ENOUGH
TO SUPPORT A MOSTLY RAIN EVENT.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
STILL NOT A LOT OF CONFIDENCE WITH THE FINER DETAILS WITHIN THE
EXTENDED...THOUGH TWO GENERAL TRENDS CAN BE EXPECTED. THE FIRST
WILL BE THE INFLUENCE OF A BROAD UPPER TROF AND EMBEDDED
SHORTWAVES MOVING ACROSS THE NORTHERN TIER CONUS. MOST OF THE
PRECIPITATION WILL BE ASSOCIATED WITH AN H7 LOW THAT LOOKS TO
TRACK ACROSS NORTH DAKOTA/MINNESOTA...THOUGH IT MAY PIVOT THROUGH
WESTERN SOUTH DAKOTA DEPENDING ON THE MODEL. THIS TRACK SUGGESTS
NORTH DAKOTA WILL RECEIVE THE MAJORITY OF PRECIPITATION WITHIN THE
WARM ADVECTION BAND AND ANY TROWAL BASED WRAP AROUND. THE GFS IS
GENERALLY WEAKER WITH SIGNIFICANTLY LOWER PRECIPITATION POTENTIAL.
THE ECMWF IS STRONGER...WITH A MORE SOUTHERLY TRACK...AND STRONGER
WINDS WITH POTENTIALLY MORE IMPACTS TO THE CWA.
THE SECOND FEATURE WILL BE ANOMALOUSLY COLD AIR POURING INTO THE
REGION. TIMING DIFFERENCES CONTINUE BETWEEN THE GFS AND
ECMWF...VARYING BETWEEN TUESDAY AND WEDNESDAY RESPECTIVELY. BOTH
MODELS RESOLVE THE COLD POOL WITH SIMILAR INTENSITY AND
DURATION...AS IT WILL COME TO DOMINATE THE WEATHER THROUGH THE END
OF THE WORK WEEK.
UNFORTUNATELY...BOTH MODELS HAVE BEEN REASONABLY CONSISTENT WITH
THEIR INDIVIDUAL TRENDS. WILL CONTINUE TO BROADBRUSH THE FIRST FEW
PERIODS OF THE EXTENDED WITH CHANCE POPS/SNOW UNTIL MODELS ENTER
BETTER ALIGNMENT.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS EXPECTED AT ALL TERMINALS. LIGHT WINDS WILL BE OUT
OF THE NORTHWEST GRADUALLY SHIFTING TO THE NORTH.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...SD
LONG TERM...CONNELLY
AVIATION...CONNELLY
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
349 AM CST SAT NOV 30 2013
.SHORT TERM...TODAY THROUGH MONDAY
CHANCES FOR PRECIPITATION AS WELL AS P-TYPE WILL BE THE FORECAST
CHALLENGES.
A WEAK MID LEVEL SHORT WAVE CURRENTLY OVER MONTANA WILL TRACK
SOUTHEASTWARD ACROSS THE REGION TODAY...BRINGING PARTLY CLOUDY
SKIES TO THE CWA. THE PAST FEW RUNS OF THE RUC AND THE NSSL WRF
BOTH SHOW SOME LIGHT RAIN FOR THE FAR NW PORTION OF THE
CWA...PERHAPS REACHING KMBG BY THIS AFTERNOON. THUS HAVE ADDED A
LOW POP.
ANOTHER MID LEVEL SHORT WAVE AND FRONTAL BOUNDARY WILL TRACK
ACROSS THE REGION ON SUNDAY. MODELS HAVE SIGNIFICANTLY SLOWED DOWN
THE PROGRESSION OF THE TROUGH...WITH PCPN NOT REACHING THE JAMES
RIVER VALLEY UNTIL AFTER 18Z. IT STILL APPEARS AS THOUGH THE
LEADING EDGE OF THE PCPN WILL FALL AS ALL SNOW. HOWEVER WITH WAA
QUICKLY PUSHING IN ON THE BACK SIDE...THE SNOW WILL TRANSITION
OVER TO ALL RAIN. THIS SYSTEM DOES NOT CONTAIN A GREAT DEAL OF LOW
LEVEL MOISTURE SO WILL MAINTAIN CHC POP ALONG THE ND/SD BORDER FOR
NOW. A MUCH STRONGER STORM SYSTEM WILL BEGIN IMPACTING THE REGION
ON MONDAY. HOWEVER MODEL ARE NOT IN A REAL GOOD AGREEMENT WITH THE
OVERALL PLACEMENT OF THIS MID LEVEL CLOSED LOW...WHICH LEADS TO A
LOW FORECASTER CONFIDENCE. EVEN WITH A DISAGREEMENT ON THE PLACEMENT
THERE IS A GENERAL CONSENSUS THAT TEMPERATURES WILL BE WARM ENOUGH
TO SUPPORT A MOSTLY RAIN EVENT.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
STILL NOT A LOT OF CONFIDENCE WITH THE FINER DETAILS WITHIN THE
EXTENDED...THOUGH TWO GENERAL TRENDS CAN BE EXPECTED. THE FIRST
WILL BE THE INFLUENCE OF A BROAD UPPER TROF AND EMBEDDED
SHORTWAVES MOVING ACROSS THE NORTHERN TIER CONUS. MOST OF THE
PRECIPITATION WILL BE ASSOCIATED WITH AN H7 LOW THAT LOOKS TO
TRACK ACROSS NORTH DAKOTA/MINNESOTA...THOUGH IT MAY PIVOT THROUGH
WESTERN SOUTH DAKOTA DEPENDING ON THE MODEL. THIS TRACK SUGGESTS
NORTH DAKOTA WILL RECEIVE THE MAJORITY OF PRECIPITATION WITHIN THE
WARM ADVECTION BAND AND ANY TROWAL BASED WRAP AROUND. THE GFS IS
GENERALLY WEAKER WITH SIGNIFICANTLY LOWER PRECIPITATION POTENTIAL.
THE ECMWF IS STRONGER...WITH A MORE SOUTHERLY TRACK...AND STRONGER
WINDS WITH POTENTIALLY MORE IMPACTS TO THE CWA.
THE SECOND FEATURE WILL BE ANOMALOUSLY COLD AIR POURING INTO THE
REGION. TIMING DIFFERENCES CONTINUE BETWEEN THE GFS AND
ECMWF...VARYING BETWEEN TUESDAY AND WEDNESDAY RESPECTIVELY. BOTH
MODELS RESOLVE THE COLD POOL WITH SIMILAR INTENSITY AND
DURATION...AS IT WILL COME TO DOMINATE THE WEATHER THROUGH THE END
OF THE WORK WEEK.
UNFORTUNATELY...BOTH MODELS HAVE BEEN REASONABLY CONSISTENT WITH
THEIR INDIVIDUAL TRENDS. WILL CONTINUE TO BROADBRUSH THE FIRST FEW
PERIODS OF THE EXTENDED WITH CHANCE POPS/SNOW UNTIL MODELS ENTER
BETTER ALIGNMENT.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD. LIGHT WINDS WILL
PERSIST OVERNIGHT BEFORE SWITCHING TO NORTH-NORTHWEST AROUND 5 TO
10 KNOTS ON SATURDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...SD
LONG TERM...CONNELLY
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
900 PM CST SUN DEC 1 2013
.UPDATE...
AT 9PM THIS EVENING MOST OF NORTH TEXAS WAS UNDER A SHIELD OF
CIRRUS BUT THIS IS THINNING OUT FROM NORTH TO SOUTH AS A FAST
MOVING SHORTWAVE SKIRTS ON BY. AT THE SURFACE...A WEAK TROUGH IS
LOCATED ACROSS EAST-CENTRAL OKLAHOMA INTO THE NORTHWEST PARTS OF
THE CWA. A SUBTLE WIND SHIFT TAKES PLACE BEHIND THIS BOUNDARY BUT
GENERALLY LIGHT WINDS PREVAIL. WITH DEWPOINTS IN THE UPPER 40S TO
MID 50S AND SKIES CLEARING WITH THE PASSAGE OF THE
SHORTWAVE...AREAS OF FOG MAY BEGIN TO DEVELOP OVER THE NEXT
SEVERAL HOURS. THE MOST FAVORED AREAS FOR FOG DEVELOPMENT WILL BE
ACROSS THE NORTHEAST COUNTIES...WHERE THE COMBINATION OF HIGHEST
SURFACE MOISTURE AND MAXIMUM RADIATIONAL COOLING OCCURS. TEMPS
COOLING INTO THE UPPER 40S AND LOW 50S SHOULD BE SUFFICIENT FOR
FOG TO DEVELOP. A LITTLE FARTHER WEST...SOME SLIGHTLY DRIER AIR
MAY LIMIT FOG POTENTIAL SOMEWHAT. FOR NOW...WILL ADD SOME PATCHY
DENSE FOG TO THE NORTHEAST COUNTIES AND MONITOR FOR POTENTIAL
DENSE FOG ADVISORY. OTHERWISE...NO SIGNIFICANT CHANGES MADE AT
THIS TIME.
DUNN
&&
.AVIATION...
/00Z TAFS/
OVERNIGHT RESTRICTIONS TO VSBYS AND POSSIBLY CIGS WILL BE CHALLENGING
AS A WEAK SURFACE TROUGH NEAR THE RED RIVER EASES SOUTHEAST TOWARD
DFW TERMINALS RIGHT BEFORE MIDNIGHT. WE DO NOT EXPECT THE TROUGH
TO REACH WACO THROUGH MONDAY MORNING. THICK CIRRUS OVERNIGHT WILL
ALSO PLAY A ROLE AND NOT THIN OUT UNTIL A SHORTWAVE DISTURBANCE
PASSES EAST OF THE AREA BETWEEN MIDNIGHT AND SUNRISE MONDAY.
AFTER EXTENSIVE COLLABORATION WITH OUR CWSU PARTNERS...THINKING IS
THE NAM/RUC ARE PROBABLY CLOSER TO REALITY WITH AREAS APPROACHING
NEAR SATURATION RIGHT AT THE SURFACE AND UNDER THE STRONG SURFACE
INVERSION. THE NAM BUFR SOUNDINGS ARE THE MOST BULLISH WITH POSSIBLE
DENSE FOG AND LIFR/VLIFR CONDITIONS AS WINDS WEAKEN BELOW 5 KTS ON
EITHER SIDE OF THE SURFACE TROF. THE GFS IS MUCH DRIER...BUT ALSO
STRONGER/FASTER WITH THE SFC TROF WHICH DOES NOT APPEARS TO BE
AGREEING WITH CONDITIONS UPSTREAM AT THE MOMENT.
THE RUC SEEMS TO BE IN THE MIDDLE AND THIS IS WHERE WE WILL LEAN
WITH THIS TAF FORECAST BY INTRODUCING IFR VSBYS/2-3SM BR NEAR THE
SURFACE TROF AT DFW AREA TERMINALS AND MVFR VSBYS/4-5SM BR AT WACO
FURTHER AWAY FROM THE TROF. WE HAVE NOT INTRODUCED CIGS RESTRICTIONS
FOR FOR NOW WITH ALL THE UNCERTAINTY...THOUGH IT CERTAINLY BEARS
WATCHING AND IF THINGS SET UP JUST RIGHT...WE COULD SEE WHAT THE
NAM BUFR SOUNDINGS SHOW. AGAIN THE TRENDS OF THE THICK CIRRUS
OVERHEAD WILL HAVE SOME BEARING ON RADIATIONAL COOLING AS WELL.
OTHERWISE...LOOK FOR LIGHT S/SW WINDS 5-8 KTS TO CONTINUE THIS
EVENING AHEAD OF THE SURFACE TROF...GOING LIGHT W/NW WINDS 5 KTS
OR LESS BEHIND THE SURFACE TROF AT DFW TERMINALS BY MIDNIGHT.
05/
&&
.PREV DISCUSSION... /ISSUED 345 PM CST SUN DEC 1 2013/
A WARM START TO THE WORK WEEK FOLLOWED BY A COLD AND UNSETTLED WEEKEND.
AFTER A CLOUDY AND WARM DAY TODAY...TEMPERATURES TONIGHT WILL COOL
INTO THE 40S AND 50S AS CLOUDS DECREASE AND A WEAK COLD FRONT
MOVES INTO THE REGION. THE FRONT DOES NOT HAVE MUCH OF A PUSH AND
WILL ONLY BRING SLIGHTLY DRIER AND COOLER AIR. THE FRONT WILL LIFT
QUICKLY NORTH ON MONDAY AS SURFACE LOW PRESSURE DEEPENS OVER THE
NORTHERN AND CENTRAL HIGH PLAINS. QUICK RETURN FLOW...ABUNDANT SUN
AND A SOUTHWEST WIND COMPONENT WILL RESULT IN VERY MILD TEMPERATURES
MONDAY WITH HIGHS GENERALLY IN THE 70S. OVERNIGHT LOWS MONDAY
NIGHT WILL RANGE FROM THE LOWER 40S TO THE MIDDLE 50S UNDER A
CLEAR TO PARTLY CLOUDY SKY.
TUESDAY WILL BE ANOTHER WARM DAY WITH ZONAL FLOW ALOFT...A BREEZY
SOUTHWEST WIND AND A MOSTLY SUNNY SKY. AFTERNOON HIGHS TUESDAY
WILL RANGE FROM THE LOWER 70S IN THE NORTHEAST TO THE LOWER 80S IN
THE SOUTHWEST ZONES.
THE GFS CONTINUES TO SHOW A SHORT WAVE TROUGH MOVING EAST ACROSS
THE NORTHERN PLAINS TUESDAY NIGHT WHICH IT HAS BEEN ADVERTISING
FOR THE LAST SEVERAL RUNS. THE 00Z ECMWF ALSO HAD A SIMILAR
SOLUTION. HOWEVER...THE PAST TWO 12Z ECMWF RUNS HAVE KEPT A LARGE
UPPER TROUGH MORE CONSOLIDATED OVER THE WESTERN STATES. OUR THINKING
WITH YESTERDAYS PACKAGE WAS THAT THE ECMWF SOLUTION HAD A BETTER
HANDLE ON THINGS...BUT IT IS HARD TO ARGUE WITH THE RUN TO RUN
CONSISTENCY OF THE GFS. THEREFORE...WILL SIDE CLOSER TO THIS
SOLUTION IN REGARDS TO THE MOVEMENT OF THE SHORT WAVE ACROSS THE
NORTHERN PLAINS TUESDAY NIGHT AND THE SOUTHWARD MOVEMENT OF A COLD
FRONT ON WEDNESDAY. THE FRONT SHOULD MOVE ACROSS NORTH TEXAS
DURING THE DAY WEDNESDAY AND BRING FALLING TEMPERATURES. SINCE
MOISTURE WILL BE LIMITED...WE DO NOT EXPECT ANY PRECIPITATION WITH
THE FRONT. TEMPERATURES WEDNESDAY NIGHT WILL FALL INTO THE 30S IN
THE NORTH WITH GENERALLY 40S ELSEWHERE.
THE WEATHER WILL BE ON THE DOWN HILL SLIDE BEGINNING OVERNIGHT
WEDNESDAY/THURSDAY WITH COLD AIR IN PLACE AT THE SURFACE AND A
DEEP LONG WAVE TROUGH ACROSS THE WESTERN CONUS. INCREASING LIFT
OVER THE FRONT WILL BRING A CHANCE OF A COLD RAIN ACROSS THE
ENTIRE REGION WEDNESDAY NIGHT THROUGH THURSDAY. TEMPERATURE
PROFILES SUGGEST THAT ALL PRECIPITATION DURING THIS TIME PERIOD
WILL BE LIQUID WITH SURFACE TEMPERATURES ABOVE FREEZING AND A
STRONG WARM NOSE IN PLACE ABOVE THE SURFACE. MID LEVEL LAPSE RATES
SHOULD BE STEEP ENOUGH TO SUPPORT ISOLATED THUNDERSTORMS AS WELL.
HIGHS ON THURSDAY SHOULD ONLY MAKE IT INTO THE 40S AND WILL FALL
DURING THE AFTERNOON WITH INCREASING COLD AIR ADVECTION.
TEMPERATURES THURSDAY EVENING WILL COOL INTO THE 30S IN MOST
LOCATIONS...BUT SHOULD STILL REMAIN ABOVE FREEZING. TEMPERATURES
OVERNIGHT THURSDAY THROUGH FRIDAY MORNING WILL MOST LIKELY FALL
BELOW FREEZING NEAR AND NORTHWEST OF A LAMPASAS...HILLSBORO...TO
BONHAM LINE. LARGE SCALE LIFT WILL CONTINUE ACROSS THE ENTIRE
REGION DURING THE OVERNIGHT/MORNING HOURS ON FRIDAY AS ENERGY
EMBEDDED IN SOUTHWEST FLOW ALOFT TRANSLATES ACROSS THE REGION.
FORECAST SOUNDINGS POINT TO FREEZING RAIN AS THE PREDOMINATE
WEATHER TYPE IN LOCATIONS THAT ARE FREEZING OR BELOW FRIDAY
MORNING. MOISTURE IS STILL IN QUESTION...BUT THERE SHOULD BE
ENOUGH TO PRODUCE SOME FREEZING PRECIPITATION THAT COULD LEAD TO
IMPACTS. IT IS STILL TOO EARLY TO ASSESS JUST HOW MUCH FREEZING
RAIN WILL FALL. HOWEVER...ONE THING THAT HAS US CONCERNED IS THAT
TEMPERATURES SHOULD BE WELL BELOW FREEZING IN MANY AREAS...
ESPECIALLY THE NORTHWEST ZONES. PRECIPITATION SHOULD END FROM WEST
TO EAST FRIDAY AFTERNOON AS THE IMPULSE EXITS THE REGION. THERE
WILL STILL BE A SLIGHT CHANCE OF FREEZING RAIN OR POSSIBLY A MIX
OF FREEZING RAIN AND SLEET IN THE NORTHWEST ZONES FRIDAY AFTERNOON
WITH MAINLY RAIN IN THE EAST.
FRIDAY NIGHT SHOULD BE COLD AND PRECIPITATION-FREE DUE TO SOME
DRY AIR MOVING IN BEHIND THE EXITING IMPULSE. EXPECT LOWS SATURDAY
MORNING MAINLY BELOW FREEZING WITH EVEN SOME LOWER AND MIDDLE 20S
IN THE NORTHWEST. TEMPERATURES ON SATURDAY SHOULD WARM ABOVE
FREEZING IN ALL ZONES. THERE WILL BE A SLIGHT CHANCE OF RAIN
ACROSS THE EAST/SOUTHEAST ZONES AS SOME WEAK LARGE SCALE LIFT
MOVES ACROSS THE REGION. PRECIPITATION CHANCES COULD CONTINUE INTO
SUNDAY WITH THE FRONT STILL IN PLACE AND THE UPPER TROUGH STILL
WEST OF THE REGION. MOISTURE WILL BE IN QUESTION ACROSS NORTH
TEXAS SUNDAY SO WILL KEEP ONLY SLIGHT RAIN CHANCES MENTIONED IN
THE SOUTHEAST ZONES.
AS WITH ANY EVOLVING WEATHER SYSTEM...MODEL SOLUTIONS WILL CHANGE
IN THE COMING DAYS AND ADJUSTMENTS WILL MOST CERTAINLY BE MADE.
ONE OF THE CONCERNING THINGS WITH THIS SOLUTION IS THAT THE COLD
AIR IN THE LOW LEVELS WOULD BE IN PLACE FOR SEVERAL DAYS WITH
UPPER LEVEL ENERGY WEST OF THE REGION. THIS COULD RESULT IN MULTIPLE
TIME PERIODS WITH SOME TYPE OF WINTER PRECIPITATION NEXT WEEKEND.
STAY TUNED....
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 49 72 50 79 52 / 5 0 0 5 10
WACO, TX 49 74 49 80 55 / 5 0 0 5 10
PARIS, TX 48 68 47 73 51 / 10 0 5 5 10
DENTON, TX 45 72 42 78 46 / 5 0 0 5 10
MCKINNEY, TX 44 72 44 74 51 / 10 0 0 5 10
DALLAS, TX 49 72 50 79 55 / 5 0 0 5 10
TERRELL, TX 49 72 48 77 55 / 10 0 0 5 10
CORSICANA, TX 49 73 52 80 58 / 10 0 0 5 10
TEMPLE, TX 52 73 49 81 57 / 5 0 0 5 10
MINERAL WELLS, TX 40 75 41 81 44 / 5 0 0 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
553 PM CST SUN DEC 1 2013
.AVIATION...
/00Z TAFS/
OVERNIGHT RESTRICTIONS TO VSBYS AND POSSIBLY CIGS WILL BE CHALLENGING
AS A WEAK SURFACE TROUGH NEAR THE RED RIVER EASES SOUTHEAST TOWARD
DFW TERMINALS RIGHT BEFORE MIDNIGHT. WE DO NOT EXPECT THE TROUGH
TO REACH WACO THROUGH MONDAY MORNING. THICK CIRRUS OVERNIGHT WILL
ALSO PLAY A ROLE AND NOT THIN OUT UNTIL A SHORTWAVE DISTURBANCE
PASSES EAST OF THE AREA BETWEEN MIDNIGHT AND SUNRISE MONDAY.
AFTER EXTENSIVE COLLABORATION WITH OUR CWSU PARTNERS...THINKING IS
THE NAM/RUC ARE PROBABLY CLOSER TO REALITY WITH AREAS APPROACHING
NEAR SATURATION RIGHT AT THE SURFACE AND UNDER THE STRONG SURFACE
INVERSION. THE NAM BUFR SOUNDINGS ARE THE MOST BULLISH WITH POSSIBLE
DENSE FOG AND LIFR/VLIFR CONDITIONS AS WINDS WEAKEN BELOW 5 KTS ON
EITHER SIDE OF THE SURFACE TROF. THE GFS IS MUCH DRIER...BUT ALSO
STRONGER/FASTER WITH THE SFC TROF WHICH DOES NOT APPEARS TO BE
AGREEING WITH CONDITIONS UPSTREAM AT THE MOMENT.
THE RUC SEEMS TO BE IN THE MIDDLE AND THIS IS WHERE WE WILL LEAN
WITH THIS TAF FORECAST BY INTRODUCING IFR VSBYS/2-3SM BR NEAR THE
SURFACE TROF AT DFW AREA TERMINALS AND MVFR VSBYS/4-5SM BR AT WACO
FURTHER AWAY FROM THE TROF. WE HAVE NOT INTRODUCED CIGS RESTRICTIONS
FOR FOR NOW WITH ALL THE UNCERTAINTY...THOUGH IT CERTAINLY BEARS
WATCHING AND IF THINGS SET UP JUST RIGHT...WE COULD SEE WHAT THE
NAM BUFR SOUNDINGS SHOW. AGAIN THE TRENDS OF THE THICK CIRRUS
OVERHEAD WILL HAVE SOME BEARING ON RADIATIONAL COOLING AS WELL.
OTHERWISE...LOOK FOR LIGHT S/SW WINDS 5-8 KTS TO CONTINUE THIS
EVENING AHEAD OF THE SURFACE TROF...GOING LIGHT W/NW WINDS 5 KTS
OR LESS BEHIND THE SURFACE TROF AT DFW TERMINALS BY MIDNIGHT.
05/
&&
.PREV DISCUSSION... /ISSUED 345 PM CST SUN DEC 1 2013/
A WARM START TO THE WORK WEEK FOLLOWED BY A COLD AND UNSETTLED WEEKEND.
AFTER A CLOUDY AND WARM DAY TODAY...TEMPERATURES TONIGHT WILL COOL
INTO THE 40S AND 50S AS CLOUDS DECREASE AND A WEAK COLD FRONT
MOVES INTO THE REGION. THE FRONT DOES NOT HAVE MUCH OF A PUSH AND
WILL ONLY BRING SLIGHTLY DRIER AND COOLER AIR. THE FRONT WILL LIFT
QUICKLY NORTH ON MONDAY AS SURFACE LOW PRESSURE DEEPENS OVER THE
NORTHERN AND CENTRAL HIGH PLAINS. QUICK RETURN FLOW...ABUNDANT SUN
AND A SOUTHWEST WIND COMPONENT WILL RESULT IN VERY MILD TEMPERATURES
MONDAY WITH HIGHS GENERALLY IN THE 70S. OVERNIGHT LOWS MONDAY
NIGHT WILL RANGE FROM THE LOWER 40S TO THE MIDDLE 50S UNDER A
CLEAR TO PARTLY CLOUDY SKY.
TUESDAY WILL BE ANOTHER WARM DAY WITH ZONAL FLOW ALOFT...A BREEZY
SOUTHWEST WIND AND A MOSTLY SUNNY SKY. AFTERNOON HIGHS TUESDAY
WILL RANGE FROM THE LOWER 70S IN THE NORTHEAST TO THE LOWER 80S IN
THE SOUTHWEST ZONES.
THE GFS CONTINUES TO SHOW A SHORT WAVE TROUGH MOVING EAST ACROSS
THE NORTHERN PLAINS TUESDAY NIGHT WHICH IT HAS BEEN ADVERTISING
FOR THE LAST SEVERAL RUNS. THE 00Z ECMWF ALSO HAD A SIMILAR
SOLUTION. HOWEVER...THE PAST TWO 12Z ECMWF RUNS HAVE KEPT A LARGE
UPPER TROUGH MORE CONSOLIDATED OVER THE WESTERN STATES. OUR THINKING
WITH YESTERDAYS PACKAGE WAS THAT THE ECMWF SOLUTION HAD A BETTER
HANDLE ON THINGS...BUT IT IS HARD TO ARGUE WITH THE RUN TO RUN
CONSISTENCY OF THE GFS. THEREFORE...WILL SIDE CLOSER TO THIS
SOLUTION IN REGARDS TO THE MOVEMENT OF THE SHORT WAVE ACROSS THE
NORTHERN PLAINS TUESDAY NIGHT AND THE SOUTHWARD MOVEMENT OF A COLD
FRONT ON WEDNESDAY. THE FRONT SHOULD MOVE ACROSS NORTH TEXAS
DURING THE DAY WEDNESDAY AND BRING FALLING TEMPERATURES. SINCE
MOISTURE WILL BE LIMITED...WE DO NOT EXPECT ANY PRECIPITATION WITH
THE FRONT. TEMPERATURES WEDNESDAY NIGHT WILL FALL INTO THE 30S IN
THE NORTH WITH GENERALLY 40S ELSEWHERE.
THE WEATHER WILL BE ON THE DOWN HILL SLIDE BEGINNING OVERNIGHT
WEDNESDAY/THURSDAY WITH COLD AIR IN PLACE AT THE SURFACE AND A
DEEP LONG WAVE TROUGH ACROSS THE WESTERN CONUS. INCREASING LIFT
OVER THE FRONT WILL BRING A CHANCE OF A COLD RAIN ACROSS THE
ENTIRE REGION WEDNESDAY NIGHT THROUGH THURSDAY. TEMPERATURE
PROFILES SUGGEST THAT ALL PRECIPITATION DURING THIS TIME PERIOD
WILL BE LIQUID WITH SURFACE TEMPERATURES ABOVE FREEZING AND A
STRONG WARM NOSE IN PLACE ABOVE THE SURFACE. MID LEVEL LAPSE RATES
SHOULD BE STEEP ENOUGH TO SUPPORT ISOLATED THUNDERSTORMS AS WELL.
HIGHS ON THURSDAY SHOULD ONLY MAKE IT INTO THE 40S AND WILL FALL
DURING THE AFTERNOON WITH INCREASING COLD AIR ADVECTION.
TEMPERATURES THURSDAY EVENING WILL COOL INTO THE 30S IN MOST
LOCATIONS...BUT SHOULD STILL REMAIN ABOVE FREEZING. TEMPERATURES
OVERNIGHT THURSDAY THROUGH FRIDAY MORNING WILL MOST LIKELY FALL
BELOW FREEZING NEAR AND NORTHWEST OF A LAMPASAS...HILLSBORO...TO
BONHAM LINE. LARGE SCALE LIFT WILL CONTINUE ACROSS THE ENTIRE
REGION DURING THE OVERNIGHT/MORNING HOURS ON FRIDAY AS ENERGY
EMBEDDED IN SOUTHWEST FLOW ALOFT TRANSLATES ACROSS THE REGION.
FORECAST SOUNDINGS POINT TO FREEZING RAIN AS THE PREDOMINATE
WEATHER TYPE IN LOCATIONS THAT ARE FREEZING OR BELOW FRIDAY
MORNING. MOISTURE IS STILL IN QUESTION...BUT THERE SHOULD BE
ENOUGH TO PRODUCE SOME FREEZING PRECIPITATION THAT COULD LEAD TO
IMPACTS. IT IS STILL TOO EARLY TO ASSESS JUST HOW MUCH FREEZING
RAIN WILL FALL. HOWEVER...ONE THING THAT HAS US CONCERNED IS THAT
TEMPERATURES SHOULD BE WELL BELOW FREEZING IN MANY AREAS...
ESPECIALLY THE NORTHWEST ZONES. PRECIPITATION SHOULD END FROM WEST
TO EAST FRIDAY AFTERNOON AS THE IMPULSE EXITS THE REGION. THERE
WILL STILL BE A SLIGHT CHANCE OF FREEZING RAIN OR POSSIBLY A MIX
OF FREEZING RAIN AND SLEET IN THE NORTHWEST ZONES FRIDAY AFTERNOON
WITH MAINLY RAIN IN THE EAST.
FRIDAY NIGHT SHOULD BE COLD AND PRECIPITATION-FREE DUE TO SOME
DRY AIR MOVING IN BEHIND THE EXITING IMPULSE. EXPECT LOWS SATURDAY
MORNING MAINLY BELOW FREEZING WITH EVEN SOME LOWER AND MIDDLE 20S
IN THE NORTHWEST. TEMPERATURES ON SATURDAY SHOULD WARM ABOVE
FREEZING IN ALL ZONES. THERE WILL BE A SLIGHT CHANCE OF RAIN
ACROSS THE EAST/SOUTHEAST ZONES AS SOME WEAK LARGE SCALE LIFT
MOVES ACROSS THE REGION. PRECIPITATION CHANCES COULD CONTINUE INTO
SUNDAY WITH THE FRONT STILL IN PLACE AND THE UPPER TROUGH STILL
WEST OF THE REGION. MOISTURE WILL BE IN QUESTION ACROSS NORTH
TEXAS SUNDAY SO WILL KEEP ONLY SLIGHT RAIN CHANCES MENTIONED IN
THE SOUTHEAST ZONES.
AS WITH ANY EVOLVING WEATHER SYSTEM...MODEL SOLUTIONS WILL CHANGE
IN THE COMING DAYS AND ADJUSTMENTS WILL MOST CERTAINLY BE MADE.
ONE OF THE CONCERNING THINGS WITH THIS SOLUTION IS THAT THE COLD
AIR IN THE LOW LEVELS WOULD BE IN PLACE FOR SEVERAL DAYS WITH
UPPER LEVEL ENERGY WEST OF THE REGION. THIS COULD RESULT IN MULTIPLE
TIME PERIODS WITH SOME TYPE OF WINTER PRECIPITATION NEXT WEEKEND.
STAY TUNED....
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 49 72 50 79 52 / 5 0 0 5 10
WACO, TX 49 74 49 80 55 / 5 0 0 5 10
PARIS, TX 48 68 47 73 51 / 10 0 5 5 10
DENTON, TX 45 72 42 78 46 / 5 0 0 5 10
MCKINNEY, TX 44 72 44 74 51 / 10 0 0 5 10
DALLAS, TX 49 72 50 79 55 / 5 0 0 5 10
TERRELL, TX 49 72 48 77 55 / 10 0 0 5 10
CORSICANA, TX 49 73 52 80 58 / 10 0 0 5 10
TEMPLE, TX 52 73 49 81 57 / 5 0 0 5 10
MINERAL WELLS, TX 40 75 41 81 44 / 5 0 0 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/79
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1226 AM EST SAT NOV 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL BE ACROSS THE REGION THROUGH THE WEEKEND WHILE
A SERIES OF UPPER LEVEL DISTURBANCES PASS NORTH OF THE REGION. A
WEAK DISTURBANCE WILL PASS THROUGH THE AREA ON MONDAY WHILE AN
AREA OF LOW PRESSURE MOVES NORTH ALONG THE COAST. THE NEXT SYSTEM
TO BRING PRECIPITATION TO MOST OF OUR REGION WILL ARRIVE THURSDAY
INTO FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 920 PM EST FRIDAY
ADJUSTED OVERNIGHT MIN TEMPS DOWN A FEW DEGREES AS SKIES REMAIN
CLEAR SO FAR WITH CALMS WINDS NEARLY EVERYWHERE. STILL HOLDING TO
IDEA OF LOW CLOUDS DRIFTING SW ACROSS THE MOUNTAINS BY THE EARLY
MORNING HOURS AS SHOWN BY LATEST RAP AND NAM MODELS WHICH WOULD
ARREST THE DOWNWARD TRAJECTORY IN TEMPS SOMEWHAT. LOWERED WINDS
SLIGHTLY AS WELL BUT OTHERWISE NO SUBSTANTIVE CHANGES.
PREVIOUS VALID DISCUSSION
AS OF 300 PM EST FRIDAY...
A WEAK UPPER LEVEL DISTURBANCE WILL PROGRESS THROUGH THE GREAT LAKES
REGION TONIGHT INTO SATURDAY. SURFACE HIGH PRESSURE WILL BECOME
CENTERED OVER NEW ENGLAND BY SATURDAY MORNING...AND ITS ASSOCIATED
RIDGE AXIS WILL TRAIL SOUTHWEST ALONG THE LEE OFF THE APPALACHIANS.
LOW LEVEL MOISTURE HAS BEEN ABUNDANT TODAY FROM NORTHERN WEST
VIRGINIA...NORTH INTO PENNSYLVANIA.
TWO WEATHER PATTERNS WILL CONTRIBUTE TO INCREASING CLOUD COVER
TONIGHT INTO SATURDAY. FIRST...THE ADVANCING SYSTEM THROUGH THE
GREAT LAKES REGION HAS ALREADY ALLOWED FOR SOME DOWNSTREAM
ADVANCEMENT OF MID TO HIGH LEVEL CLOUD COVER OVER PARTS OF INDIANA
AND KENTUCKY. THIS CLOUD COVER WILL PROGRESS INTO OUR REGION
OVERNIGHT WITH INCREASING COVERAGE THROUGH SATURDAY. THE GREATEST
CONCENTRATION WILL OVER THE NORTHERN PARTS OF THE FORECAST AREA.
SECOND...BOTH 12Z/7AM GFS AND TO A GREATER DEGREE THE 12Z/7AM NAM
ARE DEPICTING A SOUTHERN ADVANCEMENT OF THE WV/MD/PA MOISTURE ALONG
THE LEE OF THE APPALACHIANS OVERNIGHT. THIS MOISTURE IS DEPICTED AS
BEING SHALLOW WITHIN ROUGHLY THE 925-900 MB LAYER. 925 MB WINDS WILL
BE COMPARABLE TO THE ORIENTATION TYPICALLY ASSOCIATED WITH ONSET OF
A HIGH PRESSURE RIDGE ALONG COMMON DAMMING AREA. 925 MB WINDS WILL
GRADUALLY VEER OVERNIGHT TO NORTHEAST AND THEN TO THE EAST. THE
WV/MD/PA MOISTURE IS PROGGED TO GET CAUGHT UP IN THIS FLOW AND
EVENTUALLY TAKE AN UPSLOPE ORIENTATION TO THE BLUE RIDGE. THIS WILL
HELP IN THE FORMATION OF LOW LEVEL CLOUD COVER ACROSS THOSE REGIONS
OF THE FORECAST AREA GENERALLY ALONG AND WEST OF THE CREST OF THE
BLUE RIDGE. THE WINDOW OF BEST COVERAGE WILL BE FROM ROUGHLY 300 AM
SATURDAY THROUGH 10AM SATURDAY. PAST THIS POINT THE NOCTURNAL
INVERSION WILL HAVE ERODED AND THE CLOUDS BEGIN TO DISSIPATE. FOR
LOWS TONIGHT...I HAVE FAVORED NUMBERS AT OR SLIGHTLY ABOVE GUIDANCE
IN THOSE AREAS THAT WILL EXPERIENCE THE BULK OF THE AFOREMENTIONED
CLOUD COVER.
FOR SATURDAY...THE REGION WILL STILL BE CONTENDING WITH THE MID TO
HIGH LEVEL CLOUD COVER...AGAIN PRIMARILY IN THE NORTH...IN
ASSOCIATION WITH PASSING SHORTWAVE TROUGH TO OUR NORTH. CLOSER TO THE
SURFACE...THE 925 MB FLOW BECOMES EASTERLY THE WHOLE WAY TO THE
COAST. THIS WILL ALLOW ATLANTIC MOISTURE TO PROGRESS INTO AT LEAST
THE PIEDMONT REGION OF THE FORECAST AREA BY THE LATE AFTERNOON. WILL
BE SHOWING INCREASING CLOUD COVER IN THIS REGION TO ACCOUNT FOR
THIS. HAVE NOT DEVIATED TOO FAR FROM A BLEND OF THE GFS AND NAM MOS
FOR HIGH TEMPERATURES.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 240 PM EST FRIDAY...
ZONAL FLOW ALOFT OVER THE MID APPALACHIAN AND MID ATLANTIC REGION
WILL GRADUALLY BE REPLACED BY MEAN TROFING OVER THE EASTERN PORTION
OF THE NATION BY THE END OF THE SHORT TERM PERIOD AS A SERIES OF
WEAK SHORT WAVE TROFS EMBEDDED IN NORTHERN STREAM HELPS TO SLOWLY
BUCKLE UPPER FLOW.
PRESENCE OF WEAK SURFACE HIGH PRESSURE...NEGLIGIBLE THERMAL
ADVECTION...AND PRESENCE OF HIGH AND OCCASIONALLY MID LEVEL CLOUDS
UNDER REGION OF CHANNELIZED VORTICITY SHOULD MAINTAIN RATHER
UNEVENTFUL WEATHER OVER THE BLACKSBURG FORECAST AREA SATURDAY NIGHT
THROUGH SUNDAY NIGHT WITH SOMEWHAT MODERATED DIURNAL TEMPERATURE
PROFILE. NIGHTTIME LOWS EXPECTED TO RANGE FROM THE MID 20S TO LOWER
30S IN MOST AREAS...WITH COOLEST READINGS IN THE DEEPER VALLEYS...
AND MILDER READINGS ACROSS THE RIDGELINES AND NC FOOTHILLS. DAYTIME
HIGHS ON SATURDAY EXPECTED TO RANGE FROM THE LOWER TO MID 40S IN THE
MOUNTAINS TO LOWER 50S ACROSS THE PIEDMONT.
A MORE SIGNIFICANT SHORT WAVE IS EXPECTED TO AMPLIFY UPPER FLOW AS
IT DIVES EAST-SOUTHEAST OUT OF THE MISSISSIPPI VALLEY ON
MONDAY...REACHING THE EAST COAST BY LATE MONDAY NIGHT. BACKING FLOW
ALOFT WILL HELP STRENGTHEN BAROCLINIC ZONE ALONG THE SOUTHEAST
COAST...RESULTING IN CYCLOGENESIS WITH SURFACE LOW EXPECTED TO
DEVELOP AND STRENGTHEN ALONG THE COAST BY LATE IN SHORT TERM PERIOD.
MID-RANGE MODELS NOT YET CONSISTENTLY RESOLVING DEVELOPMENT...
PLACEMENT...AND TIMING OF THIS FEATURE...YET MOST IMPLY THAT FLOW
WILL NOT AMPLIFY SUFFICIENTLY OR SOON ENOUGH TO ALLOW DEVELOPING
AREA OF PRECIPITATION IN ISENTROPIC ZONE TO SIGNIFICANTLY THREATEN
BLACKSBURG AREA OF CONCERN BEFORE MOVING OFF THE EAST.
CONSIDERING THAT PAST COUPLE OF MODEL TRENDS HAVE BECOME A BIT MORE
BULLISH IN AMPLIFICATION OF THIS SYSTEM...WILL CONTINUE TO MAINTAIN A
LOW THREAT FOR PRECIPITATION IN MOST AREAS MONDAY AFTERNOON INTO
MONDAY NIGHT...WITH HIGHEST THREAT FOR PRECIPITATION EXPECTED TO BE
RESTRICTED TO MAINLY NORTHWESTERN MOUNTAINS WHERE LOCAL UPSLOPING
WILL BE MAXIMIZED.
CONSIDERING THERMAL PROFILE...ANY PRECIPITATION ON MONDAY WILL
LIKELY COME IN THE FORM OF SPOTTY LIGHT SHOWERS...HOWEVER INCREASING
COLD ADVECTION ON BACKSIDE OF COASTAL LOW WILL LIKELY BE/BECOME
SUFFICIENT ENOUGH TO ALLOW CHANGEOVER TO SNOW OR RAIN/SNOW MIX IN
MOUNTAINS ON MONDAY NIGHT. FURTHER EAST...EVEN IF COASTAL LOW IS
ABLE TO CRANK UP FAST ENOUGH TO PUSH PRECIPITATION UNDER DEVELOPING
DEFORMATION ZONE WESTWARD INTO EASTERN PIEDMONT COUNTIES...THERMAL
PROFILE IN THAT AREA LIKELY TO REMAIN ABOVE FREEZING (HENCE ONLY A
COLD RAIN) UNTIL SYSTEM LIFTS AWAY FROM THE AREA BY/BEFORE DAYBREAK
TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM EST FRIDAY...
THE BEGINNING OF THE LONG TERM PERIOD WILL BEGIN WITH SOME UPSLOPE
PRECIPITATION ACROSS THE MOUNTAINS. BOTH THE GFS AND THE ECMWF SHOW
PRECIPITATION THROUGH ABOUT 6Z WEDNESDAY. LIKELY WILL BE SNOW
SHOWERS ACROSS WESTERN GREENBRIER WITH A MIX OF RAIN AND SNOW ACROSS
LOWER ELEVATION MOUNTAIN AREAS. MODELS ALSO AGREE THAT THERE WILL
CONTINUE TO BE A GENERAL WARMING TREND AS 500 MB HEIGHT LEVELS
CONTINUE TO RISE THROUGH THE WEEK. FROM THURSDAY ON THROUGH SATURDAY
850MB TEMPS WILL BE +5-10C. THIS SHOULD ALLOW DAYTIME MAX TEMPS TO
EASILY REACH THE 50S AND EVEN LOWER 60S EAST OF THE BLUE RIDGE BY
THE END OF THE WEEK.
WHILE WE WILL BE WARMER...A STRONG COLD FRONT WILL BEGIN TO APPROACH
THE REGION ON THURSDAY AND FRIDAY. BOTH THE GFS AND ECMWF BRING
MOISTURE IN AHEAD OF THE FRONT. CHANCE SHOWERS ARE MENTIONED FROM
THURSDAY THROUGH THE REST OF THE LONG TERM PERIOD ON 12Z SATURDAY.
LOOKING BEYOND SATURDAY...A DEEP TROUGH ACROSS THE WESTERN UNITED
STATES WILL BRING PLENTY OF COLD AIR FROM CANADA ALL THE WAY INTO
THE CENTRAL PLAINS. BY THE END OF THE 240HR MODEL RUN OUR REGION
CONTINUES TO BE UNDER THE INFLUENCE OF THE RIDGE AND THUS WILL STAY
ON THE WARMER SIDE. A CLOSER EYE WILL BE PAID TO FUTURE MODEL RUNS
TO SEE HOW THE PATTERN PROGRESSES.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1210 AM EST SATURDAY...
VFR CONDITIONS EXPECTED DURING MUCH OF THIS PERIOD. PREVIOUS
FORECASTS WERE THINKING SOME MVFR CIGS AT BLF/LWB/BCB. 00Z
SOUNDING AT RNK...FORECAST MODEL SOUNDINGS AND SATELLITE SHOW NO
INDICATION THAT LOWER CIGS WILL BE DEVELOP DUE TO DRY AIR. WILL GO
WITH SCT020 AROUND 09Z...BUT CONFIDENCE IS HIGH THAT MVFR CIGS
WILL NOT FORM.
HIGH PRESSURE WEDGED SOUTHWARD ACROSS THE MID ATLANTIC INTO THE
CAROLINAS WITH TIGHER GRADIENT OVER THE MTNS WILL LEAD TO SOME
GUSTS TO 20-25 KNOTS AT BLF EARLY BEFORE RELAXING.
MVFR CIGS ARE POSSIBLE SATURDAY AFTERNOON AND EVENING IN THE
PIEDMONT AS LOW LEVEL WINDS VEER MORE EASTERLY AND WE START TO
TAP ATLANTIC MOISTURE INTO THE REGION. BY LATE SATURDAY NIGHT LOW
LEVEL WINDS ARE EXPECTED TO HAVE VEERED SOUTHWEST...AND WE LOSE
THE UPLSOPE COMPONENT RESPONSIBLE FOR THE MVFR CLOUDS. WITH
CONFIDENCE IN THIS REMAINING LOW WILL ONLY HAVE FEW-SCT MVFR AT
DAN/LYH.
SUNDAY INTO MONDAY MAINLY VFR CONDITIONS ARE EXPECTED AS WE BECOME
POSITIONED BETWEEN A LOW MOVING NORTH ALONG THE COAST AND A TROUGH
AXIS OVER THE OH/TN VALLEY. ISOLATED TO SCATTERED RAIN/SNOW
SHOWERS WILL BE POSSIBLE BY MONDAY NIGHT AS THE TROUGH APPROACHES
FROM THE WEST.
TUESDAY INTO WEDNESDAY MAINLY VFR CONDITIONS ARE EXPECTED AS THE
TROUGH PASSES TO OUR EAST AND AN AREA OF LOW PRESSURE DEVELOPS OFF
THE COAST. OUR REGION WILL BE LEFT IN A NORTHWEST FLOW PATTERN
WITH THE POTENTIAL FOR UPSLOPE CLOUDS OVER THE MOUNTAINS. THERE
MAY BE PATCHY MVFR CIGS WITHIN THESE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS/PC
SHORT TERM...WERT
LONG TERM...CF
AVIATION...DS/PC/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
614 PM CST SUN DEC 1 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 307 PM CST SUN DEC 1 2013
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT UPPER TROUGH DROPPING DOWN THROUGH WESTERN BRITISH
COLUMBIA...WITH NEARLY ZONAL FLOW DOWNSTREAM ACROSS THE NORTHERN
U.S.. WITHIN THIS ZONAL FLOW...THERE ARE SOME WEAK SHORTWAVES...ONE
OVER SOUTHEAST BRITISH COLUMBIA AND A SECOND IN THE DAKOTAS. DPVA
AND WARM ADVECTION AHEAD OF THIS SECOND SHORTWAVE HAS BEEN SPREADING
MID/HIGH CLOUDS DOWNSTREAM INTO THE FORECAST AREA. SO FAR THE ONLY
SPOT PRECIPITATION HAS BEEN FALLING OUT OF THESE CLOUDS HAS BEEN
ACROSS CENTRAL NORTH DAKOTA. COMPARING THE 12Z BIS AND MPX
SOUNDINGS...MUCH MORE MOISTURE EXISTED ACROSS NORTH DAKOTA...
RELATIVELY SPEAKING AS PRECIPITABLE WATER AMOUNTS ARE ONLY 0.13
INCHES DIFFERENT. FARTHER EAST...HIGH PRESSURE HAS BUILT INTO THE
FORECAST AREA AT THE SURFACE BEHIND LAST NIGHTS COLD FRONT. THE
STRATUS THAT WAS COMING IN AHEAD OF THE HIGH PRESSURE AREA HAS
STALLED MOSTLY NORTH OF HWY 29 IN WI. 925MB TEMPS ARE ABOUT 3C
COOLER TODAY AND AS RESULT...THE SUN HAS ONLY ALLOWED THE
TEMPERATURES TO CLIMB INTO THE 30S.
MODELS ARE ALL IN GOOD AGREEMENT DIVING THE POTENT UPPER TROUGH
OVER WESTERN BRITISH COLUMBIA DIGGING INTO THE PACIFIC NORTHWEST
AND NORTHERN ROCKIES. THIS IN TURN SENDS THE SHORTWAVE IN SOUTHERN
BRITISH COLUMBIA EASTWARD...CROSSING THE FORECAST AREA MONDAY
AFTERNOON. PRIOR TO THIS SHORTWAVE...WE FIRST MUST DEAL WITH THE
SHORTWAVE IN THE DAKOTAS WHICH IS PROGGED TO COME ACROSS THE AREA
THIS EVENING. IT APPEARS ALL THE SHORTWAVE WILL BRING IS CONTINUED
MID/HIGH CLOUDS AS THE LOW LEVELS REMAIN DRY AS SHOWN NICELY IN
THE 12Z MPX SOUNDING. NOW OVERNIGHT...INCREASING 280-295K
ISENTROPIC LIFT OVER THE DAKOTAS AHEAD OF THE APPROACHING BRITISH
COLUMBIA SHORTWAVE WILL LIKELY DEVELOP PRECIPITATION FROM THE
DAKOTAS INTO CENTRAL MINNESOTA. MODELS HAVE SLOWED DOWN THE
PRECIPITATION SPREAD SOUTHEAST INTO THE FORECAST AREA PRIOR TO
12Z...WHICH SEEMS REASONABLE AND HAVE DELAYED THE PRECIPITATION
CHANCES TO LATE IN THE NIGHT. THE BETTER CHANCES FOR PRECIPITATION
COME DURING THE DAY MONDAY AS THE SHORTWAVE CROSSES THE FORECAST
AREA...PROVIDING DPVA AND A SPREAD SOUTHEASTWARD OF THE 280-295K
ISENTROPIC LIFT INTO THE FORECAST AREA. STILL...THERE ARE
DIFFERENCES WITH THE MAIN PRECIP AXIS. THE 01.12Z
CANADIAN...01.00Z/01.12Z ECMWF SUGGEST AN ALIGNMENT FROM CENTRAL
MN INTO NORTHEAST IA/FAR SOUTHWEST WI...THE 01.12Z NAM PLACES IT
MOSTLY NORTH OF I-94...AND THE 01.12Z GFS IS SORT OF A SPLIT
BETWEEN THE TWO. WITH NO CLEAR SIGNAL ON WHICH MODEL GROUP MIGHT
VERIFY...HAVE FOLLOWED A COMPROMISE. THIS COMPROMISE RESULTS IN
LOW CHANCES...20-40...BECAUSE OF THE VARIABILITY OF LOCATION.
FUTURE SHIFTS SHOULD BE ABLE TO RAISE CHANCES AND HONE IN ON AN
ALIGNMENT OF THE PRECIP AXIS.
WITH 925MB AND 850MB TEMPS PROGGED AT OR BELOW 0C ACROSS MUCH OF
THE FORECAST AREA AND EVAPORATIVE COOLING LIKELY TO TAKE PLACE
WHERE IT DOES PRECIPITATE...THINKING THAT THE PRECIPITATION WILL
MAINLY FALL IN THE FORM OF SNOW. THERE MAY BE SOME MIXING WITH
RAIN POSSIBLE IN THE AFTERNOON IF TEMPERATURES WARM INTO THE MID
TO POSSIBLY UPPER 30S AS EXPECTED. NO MODEL IS THAT HEAVY ON
QPF...MOSTLY ON THE ORDER OF A TENTH...MAYBE TWO TENTHS AT MOST.
WITH SNOW TO WATER RATIOS LIKELY IN THE 10-15 TO 1 RANGE AND
DURING THE DAY WHEN THE SUN CAN HAVE SOME IMPACT ON LIMITING
ACCUMULATIONS...THINKING MOSTLY UP TO 1 INCH OF SNOWFALL.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 307 PM CST SUN DEC 1 2013
MAIN LONG TERM FORECAST CONCERNS ARE PRECIPITATION CHANCES AND
TEMPERATURES THROUGH WEDNESDAY...THEN TEMPERATURES BEYOND THAT
AS ARCTIC AIR BEGINS TO FLOW IN.
THE BIGGEST ISSUE TO THE FORECAST IS THE EVOLUTION OF THE
TROUGHING THAT DROPS INTO THE PACIFIC NORTHWEST AND NORTHERN
ROCKIES ON MONDAY. GOOD MODEL CONSENSUS EXISTS THAT THE WESTERN
PART OF THE TROUGH IS GOING TO DIG DEEPLY THROUGH THE WESTERN
U.S.. THE EASTERN PART OF THE TROUGH...ON THE OTHER
HAND...DIFFERENCES SHOW UP WHICH HAVE HUGE IMPLICATIONS TO THE
FORECAST. THE 01.12Z NAM HAS THE EASTERN PORTION OF THE TROUGH
MOVING INTO THE DAKOTAS ON TUESDAY AS A CLOSED LOW...WHEREAS THE
01.12Z GFS/ECMWF/CANADIAN STILL HOLD IT BACK IN SOUTHWEST MONTANA.
THUS...THE NAM EXITS PRECIP THE QUICKEST COME WEDNESDAY AND BEGINS
THE FLOW OF ARCTIC AIR IN THE EARLIEST. BASED ON AVAILABLE MODEL
GUIDANCE...HAVE MOSTLY DISCOUNTED THE NAM AS AN OUTLIER. OF THE
01.12Z GFS/ECMWF/CANADIAN...THE GFS BECOMES THE NEXT FASTEST OF
EXITING THE PRECIPITATION AND BRINGING THE COLD AIR ON
WEDNESDAY...RESULTING FROM MOVING THE UPPER LOW OUT TO THE EAST
QUICKER. HARD TO SAY WHICH OF THIS MODEL GROUP IS CORRECT.
HOWEVER...ITS WORTH NOTING THAT THE ECMWF/CANADIAN HAVE SPED UP
FROM YESTERDAY...REGARDING THE UPPER LOW...EXITING THE
PRECIPITATION AND BRINGING IN THE COLD AIR. THUS...THE FORECAST
FOR MONDAY NIGHT THROUGH WEDNESDAY TAKES A BLEND OF THE
GFS/ECMWF/CANADIAN AND CONTINUITY.
FOR MUCH OF MONDAY NIGHT THROUGH TUESDAY NIGHT...THE FORECAST
AREA REMAINS IN THAT 280-295K ISENTROPIC LIFT ZONE LEFTOVER FROM
MONDAY. THE STRONGEST OF THE LIFT OVERALL STAYS CENTERED NORTH OF
I-90. PRECIPITATION CHANCES INCREASE BECAUSE MOISTURE CONTINUES TO
INCREASE AND DEEPEN. PRECIPITABLE WATER INCREASES FROM NEAR 0.5
INCH ON MONDAY TO 0.6-0.7 INCHES ON TUESDAY. WARMER AIR FLOWING IN
ON SOUTH TO SOUTHEAST 925-850MB WINDS SHOULD ALLOW PRECIPITATION
THAT IS A SNOW OR RAIN/SNOW MIX MONDAY NIGHT INTO TUESDAY MORNING
TO SWITCH MOSTLY OVER TO ALL RAIN BY TUESDAY AFTERNOON. THE ONE
EXCEPTION TO THIS IS OVER TAYLOR COUNTY WHICH IS FARTHEST FROM THE
WARMER AIR ADVECTING IN FROM THE SOUTH. WEDNESDAY IS VERY TRICKY
WITH TEMPERATURES AND PRECIPITATION CHANCES...AS IT HIGHLY DEPENDS
ON THE TIMING OF THE UPPER LOW AND AN EXPECTED COLD FRONTAL
PASSAGE. TEMPERATURES COULD EITHER BE IN THE MID 30S - LOW 40S OR
MID 20S - LOW 30S...WHICH OF COURSE GREATLY AFFECTS PRECIPITATION
TYPE. AS MENTIONED EARLIER...STUCK WITH A COMPROMISE.
SINCE THE LIFT OVERALL IS WEAK FOR MUCH OF THE MONDAY NIGHT
THROUGH WEDNESDAY TIME PERIOD...MUCH OF THE PRECIPITATION SHOULD
BE ON THE LIGHT SIDE. TAYLOR COUNTY AGAIN AS THE GREATEST SHOT OF
SEEING SNOW...BUT WITH THE LIGHT ASPECT TO THE PRECIPITATION AND
LOWER SNOW TO WATER RATIOS...ACCUMULATIONS SHOULD STAY LESS THAN 1
INCH IN EACH 6 HOUR PERIOD. NOW IF YOU TOTAL THIS UP...SNOWFALL
AMOUNTS BY WEDNESDAY EVENING END UP IN THE 4-6 INCH RANGE...BUT
SETTLING...AND POSSIBLY MIXING WITH RAIN ON TUESDAY AFTERNOON...
PUTS A LOT OF DOUBT FOR NEED OF AN ADVISORY AT THIS TIME.
AFTER WEDNESDAY...ITS ALL ABOUT THE ARCTIC AIR AS A LONGWAVE
TROUGH SETS UP FROM THE SOUTHWESTERN U.S. INTO NORTHERN ONTARIO.
THE MAIN REASON FOR ARCTIC AIR COMING IS A POLAR STREAM UPPER
TROUGH THAT DROPS SOUTH OUT OF CENTRAL CANADA AND PROGRESSES
ACROSS THE UPPER MIDWEST ON FRIDAY. AS THIS POLAR TROUGH
APPROACHES...850MB/925MB TEMPS JUST GRADUALLY DROP RIGHT THROUGH
FRIDAY. BY 00Z SATURDAY...850MB STANDARDIZED ANOMALIES ARE DOWN TO
-2.5. IF WE CAN GET SOME SNOW ON WEDNESDAY...EVEN 1 INCH TO STAY
ON THE GROUND...TEMPERATURES COULD BE QUITE A BIT COLDER THAN
FORECAST FOR THURSDAY THROUGH SATURDAY. DOES NOT LOOK LIKE ANY
REAL MEASURABLE SNOW THREAT UNTIL SUNDAY AT THE EARLIEST...AND
THATS IF THE ECMWF IS CORRECT IN TIMING OF BRINGING OUT A
STRONGER WAVE OUT OF THE WESTERN TROUGH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 614 PM CST SUN DEC 1 2013
WEATHER WILL BECOME MORE ACTIVE ACROSS THE NORTHCENTRAL U.S.
OVER THE NEXT COUPLE OF DAYS BUT IT WOULD APPEAR AS THOUGH THE
IMPACTS WILL REMAIN NORTH OF THE TAF SITES FOR THE MOST PART.
WEAK SYSTEMS MOVING THROUGH DURING THE TAF PERIOD LOOK TO BRING
VFR CLOUDS...UNTIL DEEPER SATURATION AND A BIT MORE VERTICAL
MOTION ARRIVES MONDAY AFTERNOON. SOME SHRA IS POSSIBLE MONDAY
AFTERNOON AS CEILINGS BEGIN TO FALL. CONFIDENCE IS LOWER ON JUST HOW
LOW THE CIGS WILL BECOME LATER ON MONDAY. WILL TREND THIS AS
CONFIDENCE GROWS...BUT AT THIS TIME IT LOOKS AS IF LOWER MVFR CIGS
COULD BE POSSIBLE...AND MAYBE SHSNRA EARLY MONDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
549 PM CST SUN DEC 1 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 220 PM CST SUN DEC 1 2013
SEVERAL FORECAST ISSUES THIS PERIOD INCLUDING SOUTHERN EXTENT OF
LOW CLOUDS OVERNIGHT...WHETHER LAKE EFFECT SNOW SHOWERS AFFECT
DOOR COUNTY...AND TIMING OF NEXT SYNOPTIC-SCALE SYSTEM.
WEAK LOW-LEVEL WAA TONIGHT AS WINDS BECOME SW-W. AS A RESULT
WOULD EXPECT THE LOW CLOUDS TO STICK AROUND OVER MUCH OF THE
AREA. DIURNAL CU THAT FORMED ALONG SOUTHERN EXTENT OF LOW CLOUDS
MAY DISSIPATE BUT HIGHER CLOUDS UPSTREAM MOVING IN.
REPEATED RUNS OF HRRR AND OTHER SHORT-TERM MODELS INDICATE SOME
LAKE EFFECT SNOW SHOWERS ASSOCIATED WITH POSSIBLE MESOVORTEX OVER
NORTH-CENTRAL LK MICHIGAN TONIGHT WHICH COULD CLIP DOOR COUNTY.
DELTA-T`S ARE MARGINAL BUT WILL CONTINUE WITH SMALL CHANCE OF
SNOW SHOWERS OR FLURRIES IN NORTHERN DOOR. MIN TEMPS SHOULD DROP
INTO THE 20S MOST AREAS AWAY FROM LK MICHIGAN.
ON MONDAY...WAA INCREASES AS NEXT SYSTEM APPROACHES FROM THE
WEST. SOME LIGHT SNOW OR FLURRIES EXPECTED TO MOVE INTO AT LEAST
THE WESTERN HALF OF THE AREA BY LATE AFTERNOON. STILL SOME
QUESTION AS TO HOW FAST SYSTEM BEGINS TO AFFECT AREA...SO WILL
CONTINUE TO USE MODEL BLEND WHICH RESULTS IN TIMING SIMILAR TO
PREVIOUS FORECAST. HIGH TEMP FORECAST A BLEND OF BEST PERFORMING
MOS GUIDANCE WHICH IS NOT FAR OFF FROM PREVIOUS FORECAST.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 220 PM CST SUN DEC 1 2013
A VERY CHALLENGING FORECAST PERIOD THROUGH MID WEEK DUE TO
TIMING ISSUES WITH A DEVELOPING STORM SYSTEM AND PCPN TYPE. THE
POTENTIAL EXISTS FOR WINTER HEADLINES OVER NORTH CENTRAL WISCONSIN
FOR MAINLY SNOW.
STARTING MONDAY NIGHT...NAM AND GFS CONTINUE TO REMAIN A BIT QUICKER
WITH SPREADING THE BAND OF SNOW OVER THE AREA FASTER WITH THE WARM
AIR ADVECTION. OLD ECMWF IS ABOUT 12 HOURS SLOWER WHILE THE GEM
WAS THE AVERAGE. LATEST ECMWF IS CLOSER TO THE GEM TIME WITH THE
INITIAL WAA TOWARD MONDAY NIGHT.
AVAILABLE FORECAST SOUNDINGS DO INDICATE SNOW AT THE START FOR
THE PCPN TYPE WITH AROUND AN INCH OR TWO OF ACCUMULATION BY
TUESDAY MORNING...WITH THE 2 INCH AMOUNTS TOWARD CENTRAL AND NORTH
CENTRAL AND POINTS NORTHWEST. THE AIR COLUMN LIKELY WILL REMAIN
COLD ENOUGH FOR SNOW FOR ANOTHER 2 INCHES ACROSS THE NORTH. ITS
POSSIBLE AN ADVISORY WILL BE NEEDED FOR NORTH CENTRAL AND PARTS OF
FAR NORTHEAST WISCONSIN FOR THIS INITIAL BAND. SNOW AMOUNTS APPEAR
TO DIMINISH DUE TO CONTINUED WAA AND PCPN CHANGING TO RAIN OR A
RAIN SNOW MIX. THE NAM FORECAST SOUNDING FOR RHI CHANGES THE SN
OVER BRIEFLY ZR THEN RAIN TUESDAY NIGHT THEN BACK TO SNOW LATE.
WITH FROST DEPTHS A FEW INCHES DEEP OVER MANY LOCATIONS DUE TO THE
COLD LATER HALF OF NOVEMBER...POTENTIAL OF BRIEF PERIOD ICY ROADS
DUE TO ZR AND COLD GROUND. NOT CONFIDENT OF THE ZR AT THIS TIME
BUT IF THIS BECOMES MORE OF A THREAT...WINTER WEATHER ADVISORIES
MAY BE NEEDED FOR THAT ELEMENT ALONE TOWARD TUESDAY AS WELL.
BLEND OF MEDIUM RANGE MODELS WITH THE H850 LOW TRACKS SUGGESTS THE
SYSTEM PCPN/SNOW TO REMAIN NORTHWEST OF THE AREA BUT CLOSE ENOUGH
TO PRODUCE ANOTHER INCH OR TWO OVER NORTH CENTRAL WISCONSIN. AT
THIS TIME...UP TO 6 INCHES OF SNOW POSSIBLE OVER PARTS OF NORTH
CENTRAL WISCONSIN FROM MONDAY NIGHT INTO WEDNESDAY MORNING. BUT
DUE TO THE SNOW AMOUNTS WILL BE SPREAD OVER A 36-48 PERIOD...NO
WATCH ISSUED AT THIS TIME. ANTICIPATE A LONG DURATION ADVISORY OR
TWO SHORTER WINTER ADVISORIES MAY BE NEEDED TO HANDLE THE SNOW
ACCUMULATION AND OR MIX CLOSER TO THE EVENT.
BITTERLY COLD ARCTIC AIR WILL THEN POUR INTO THE ARE IN THE WAKE
OF THE SYSTEM. WITH NEED TO HAVE A HEALTHY NORTH TO SOUTH GRADIENT
IN TEMPS LATER IN THE WEEK DUE TO THE COLDER TEMPERATURES OVER
THE ANTICIPATED SNOW COVER OVER NORTH CENTRAL WISCONSIN TO
PROBABLY LITTLE OR NO SNOW OVER CENTRAL AND EAST CENTRAL
WISCONSIN. WINDS APPEAR TO WESTERLY FOR SIGNIFICANT LAKE EFFECT
SNOWS TO REACH FAR NORTH CENTRAL WISCONSIN DURING THE ARTIC SURGE.
MEDIUM RANGE RUNS BEGIN TO DEVELOP RETURN FLOW PCPN AGAIN LATE
NEXT WEEKEND AND FOR THE START OF THE NEXT WEEK...WILL KEEP THE
FORECAST DRY THROUGH NEXT WEEKEND FOR NOW.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 546 PM CST SUN DEC 1 2013
WITH GENERALLY WEAK/DIFFUSE PATTERN ACRS THE RGN...LOW CLDS EXPECTED TO
LINGER THROUGH TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS ALBANY NY
245 AM EST MON DEC 2 2013
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR PLENTY OF CLOUDS
THROUGH EARLY MORNING...ALONG WITH THE POSSIBILITY OF SOME LIGHT
SNOW SHOWERS AND OR PATCHY LIGHT FREEZING DRIZZLE. THEN MAINLY DRY
CONDITIONS WILL PREVAIL THROUGHOUT THE REMAINDER OF THE DAY WITH
SEASONABLE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL
TOWARDS THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 245 AM...STILL PICKING LIGHT RETURNS (GENERALLY AROUND 20 DBZ
OR LESS) OFF KENX RADAR. GROUND TRUTH INDICATED VERY LITTLE IF ANY
ADDITIONAL PRECIPITATION WAS FALLING ACROSS OUR REGION SINCE REPORTS
EARLIER IN THE EVENING.
WE WILL CONTINUE THE IDEA OF LOW CHANCES OF A LIGHT WINTRY MIX
(MAINLY LIGHT SNOW AND OR LIGHT FREEZING DRIZZLE) WEST OF THE HUDSON
VALLEY...SLIGHT CHANCES HUDSON VALLEY AND AREAS EAST OF IT...THROUGH
THE MORNING DRIVE. WE WILL CONTINUE TO MONITOR AND ISSUE ANY SPECIAL
WEATHER STATEMENTS SHOULD IT BECOME MORE OBVIOUS THERE WILL BE A
PROBLEM.
PATCHY FOG ALSO REMOTELY POSSIBLE SO WILL KEEP IT IN THE FORECAST.
MINIMUM TEMPERATURES HAVE PRETTY MUCH BOTTOMED OUT...AND SHOULD STAY
WITHIN A FEW DEGREES OF 30 THROUGH THE EARLY MORNING.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY/...
THE LATEST HRRR DID INDICATE THE BEST CHANCES OF LIGHT PRECIPITATION
IN THE CAPITAL REGION WOULD BE UNFORTUNATELY AROUND THE MORNING
DRIVE. WHILE NOT TOTALLY BUYING INTO THIS IDEA...WE DID CONTINUE
SLIGHT CHANCES FOR PATCHY LIGHT FREEZING DRIZZLE AND OR LIGHT SNOW
SHOWER INTO THE MORNING HOURS. AFTER THAT TIME...THE WEAK SYSTEM
SHOULD MOVE ON BUY. CLOUDS COULD THIN ENOUGH FOR A BREAK OR TWO OF
SUNSHINE.
OUR REGION WILL REMAIN BETWEEN SYSTEMS. CLOUDS WILL DOMINATE INTO
TUESDAY. TEMPERATURES ARE EXPECTED TO CONTINUED TO BE SEASONABLE.
THE LONGWAVE TROUGH OVER THE REGION WILL DEEPEN BECOMING NEGATIVELY
TILTED OFF NEW ENGLAND COAST TUESDAY. THE MODEL GUIDANCE IS IN MUCH
BETTER AGREEMENT AND DEVELOP A LOW OFF THE SOUTHEAST COAST MONDAY
THEN TRACK IN NORTHEASTWARD AND KEEPING IT WELL OFFSHORE. IT IS
EXPECTED TO REACH NOVA SCOTIA TUESDAY NIGHT. SOME RIDGING WILL
BUILD IN AT ALL LEVELS TUESDAY NIGHT AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STORM SYSTEM WILL BE MOVING FROM THE GREAT LAKES ON WEDNESDAY
EVENING TOWARDS JAMES BAY FOR THURSDAY.
THIS STORM/S WARM FRONT LOOKS TO MOVE ACROSS OUR REGION ON WED
NIGHT...WITH STRONG WARM AIR ADVECTION TAKING PLACE. 850 HPA TEMPS
WILL SURGE AS HIGH AS +9 ACROSS OUR REGION BY THURSDAY MORNING.
ALTHOUGH MOISTURE WILL BE LIMITED...SOME LIGHT PRECIPITATION IS
EXPECTED OVERNIGHT...ESP FOR THE NORTHERN AND WESTERN PARTS OF THE
AREA. WITH THE WARMING TEMPS ALOFT...PRECIP WILL EITHER BE RAIN OR
FREEZING RAIN...WITH PTYPE DEPENDENT ON SURFACE TEMPS. MOST AREAS
LOOK TO HAVE LOW TEMPS IN THE UPPER 20S TO MID 30S IN THE EVENING
JUST BEFORE OR AT THE START OF WHEN PRECIP BEGINS...WITH TEMPS
RAPIDLY WARMING OVERNIGHT THROUGH THE 30S AND EVEN INTO THE 40S FOR
SOME AREAS. SOME SHELTERED ELEVATED VALLEYS OF THE ADIRONDACKS MAY
HANG ON TO THE SUB FREEZING AIR THE LONGEST...AND THIS IS WHERE THE
BEST THREAT FOR ANY FREEZING RAIN WILL BE. MOST LARGER
VALLEYS...SUCH AS THE HUDSON VALLEY...SHOULD ONLY SEE LIQUID
PRECIP...AS TEMPS LOOK TO BE ABOVE FREEZING DURING THE TIME OF
PRECIP. THE STORM/S COLD FRONT MAY ALLOW FOR SOME ADDITIONAL RAIN
SHOWERS DURING THE DAY ON THURSDAY...ALTHOUGH PRECIP WILL LIKELY BE
RATHER SPOTTY...AS THE BEST FORCING WILL BE WELL NORTHWEST OF THE
AREA AND THERE WON/T BE A GOOD DEAL OF MOISTURE PRESENT. MAX TEMPS
WILL BE ABOVE NORMAL...WITH 40S TO LOW 50S ACROSS THE AREA AHEAD OF
THE BOUNDARY.
BEHIND THIS FRONT...COLDER AIR WILL BEGIN TO MOVE TOWARDS THE REGION
ON FRIDAY. ALTHOUGH THE CORE OF THE COLD AIR WILL REMAIN OVER THE
NORTHERN PLAINS INITIALLY...TEMPS WILL TURN PROGRESSIVELY COLDER
THROUGH THE UPCOMING WEEKEND...WITH TEMPS NEAR OR SLIGHTLY BELOW
NORMAL BY SUNDAY. THE COLD FRONT THAT MOVED THROUGH THE REGION ON
THURSDAY WILL STALL SOUTH OF THE AREA ACROSS THE MID ATLANTIC STATES
FOR LATE IN THE WEEK. WAVES OF LOW PRESSURE MAY DEVELOP ALONG THIS
BOUNDARY AND RIDE NORTHEASTWARD ALONG IT. IF THIS FRONT REMAINS
CLOSE ENOUGH TO OUR AREA...SOME RAIN OR SNOW MAY BE POSSIBLE...ESP
FOR THE SOUTHERN HALF OF THE AREA. THE MODELS ARE UNCLEAR EXACTLY
WHERE OR IF THIS FRONT WILL STALL...AND JUST HOW COLD IT WILL BE
OVER OUR AREA. FOR NOW...WILL GO WITH CHC POPS FOR THURSDAY NIGHT
THROUGH FRIDAY NIGHT...WITH SLIGHT CHC/LOW CHC POPS FOR SAT...WITH
PRECIP RAIN OR SNOW...AND PTYPE BASED ON ELEVATION/DIURNAL TEMP
TRENDS.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SCT-BKN CIGS WITH AN OCCASIONAL REDUCTION IN VISIBILITY DUE TO
MIST/BR BUT REMAINING MVFR FLIGHT CATEGORIES ARE ANTICIPATED.
WHILE MOST OF THE TIME WILL BE DRY...A COUPLE OF OPPORTUNITIES FOR A
BRIEF LIGHT SNOW SHOWER OVERNIGHT AND ONCE AGAIN THIS AFTERNOON.
OTHERWISE...DUE TO LIMITED MOISTURE AND WEAK FORCING NOTHING
EXPECTED TO BE ORGANIZED.
WINDS WILL BE CALM OVERNIGHT...AND BECOME LIGHT OUT OF THE S-SE ON
MONDAY...GENERALLY AT LESS THAN 5 KTS.
OUTLOOK...
MON NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
WED NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA. CHC FZRA
MAINLY ACROSS THE HIGHER TERRAIN.
THU: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS.
ANY PRECIPITATION WILL BE LIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV
NEAR TERM...FRUGIS/HWJIV
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1233 AM EST MON DEC 2 2013
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR PLENTY OF CLOUDS
OVERNIGHT...ALONG WITH THE POSSIBILITY OF SOME LIGHT SNOW SHOWERS
AND OR PATCHY LIGHT FREEZING DRIZZLE THROUGH THE EARLY MORNING
HOURS. THEN MAINLY DRY CONDITIONS WILL PREVAIL THROUGHOUT THE DAY
WITH SEASONABLE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL
TOWARDS THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF MIDNIGHT...KENX RADAR WAS PICKING UP SOME LIGHT RETURNS
HEADING INTO THE CAPITAL REGION. HAD ONE REPORT OFF FACEBOOK OF
LIGHT SNOW CHANGING TO LIGHT FREEZING DRIZZLE BUT THEN BACK TO LIGHT
SNOW TO THE WEST OF THE HUDSON VALLEY.
THE ATMOSPHERE WAS SATURATING UP AS EXPECTED EARLIER.
NOT SURE IT WOULD JUST BE PATCHY FREEZING DRIZZLE THAT WOULD FALL
WITH THE RETURNS. CLOUD DECKS ARE ELEVATED AND ACCORDING TO OUR
SOUNDING...COULD SUPPORT LIGHT SNOW OR FREEZING DRIZZLE.
FOR THIS UPDATE...JUST ASSIGNED A 20 POP TO ALL OF THE
REGION...WHILE KEEP 30 POPS WEST OF THE HUDSON VALLEY. ALSO...ADDED
LIGHT SNOW SHOWERS TO ALL AREAS (ALONG WITH THE PATCHY LIGHT
FREEZING DRIZZLE). HOWEVER...MANY AREAS WILL LIKELY REMAIN DRY WITH
NO PRECIPITATION. IT WILL BE A HIT A MISS SCENARIO.
NO REAL CHANGES TO OVERNIGHT TEMPS. WITH THE CLOUDS...THEY SHOULD BE
PRETTY CLOSE TO AROUND 30 FOR AN OVERNIGHT LOW REGION WIDE (A LITTLE
COLDER IN THE MOUNTAINS).
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE LATEST HRRR DID INDICATE THE BEST CHANCES OF LIGHT PRECIPITATION
IN THE CAPITAL REGION WOULD BE UNFORTUNATELY AROUND THE MORNING
DRIVE. WHILE NOT TOTALLY BUYING INTO THIS IDEA...WE DID CONTINUE
SLIGHT CHANCES FOR PATCHY LIGHT FREEZING DRIZZLE AND OR LIGHT SNOW
SHOWER INTO THE MORNING HOURS. AFTER THAT TIME...THE WEAK SYSTEM
SHOULD MOVE ON BUY. CLOUDS COULD THIN ENOUGH FOR A BREAK OR TWO OF
SUNSHINE.
OUR REGION WILL REMAIN BETWEEN SYSTEMS. CLOUDS WILL DOMINATE INTO
TUESDAY. TEMPERATURES ARE EXPECTED TO CONTINUED TO BE SEASONABLE.
THE LONGWAVE TROUGH OVER THE REGION WILL DEEPEN BECOMING NEGATIVELY
TILTED OFF NEW ENGLAND COAST TUESDAY. THE MODEL GUIDANCE IS IN MUCH
BETTER AGREEMENT AND DEVELOP A LOW OFF THE SOUTHEAST COAST MONDAY
THEN TRACK IN NORTHEASTWARD AND KEEPING IT WELL OFFSHORE. IT IS
EXPECTED TO REACH NOVA SCOTIA TUESDAY NIGHT. SOME RIDGING WILL
BUILD IN AT ALL LEVELS TUESDAY NIGHT AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STORM SYSTEM WILL BE MOVING FROM THE GREAT LAKES ON WEDNESDAY
EVENING TOWARDS JAMES BAY FOR THURSDAY.
THIS STORM/S WARM FRONT LOOKS TO MOVE ACROSS OUR REGION ON WED
NIGHT...WITH STRONG WARM AIR ADVECTION TAKING PLACE. 850 HPA TEMPS
WILL SURGE AS HIGH AS +9 ACROSS OUR REGION BY THURSDAY MORNING.
ALTHOUGH MOISTURE WILL BE LIMITED...SOME LIGHT PRECIPITATION IS
EXPECTED OVERNIGHT...ESP FOR THE NORTHERN AND WESTERN PARTS OF THE
AREA. WITH THE WARMING TEMPS ALOFT...PRECIP WILL EITHER BE RAIN OR
FREEZING RAIN...WITH PTYPE DEPENDENT ON SURFACE TEMPS. MOST AREAS
LOOK TO HAVE LOW TEMPS IN THE UPPER 20S TO MID 30S IN THE EVENING
JUST BEFORE OR AT THE START OF WHEN PRECIP BEGINS...WITH TEMPS
RAPIDLY WARMING OVERNIGHT THROUGH THE 30S AND EVEN INTO THE 40S FOR
SOME AREAS. SOME SHELTERED ELEVATED VALLEYS OF THE ADIRONDACKS MAY
HANG ON TO THE SUB FREEZING AIR THE LONGEST...AND THIS IS WHERE THE
BEST THREAT FOR ANY FREEZING RAIN WILL BE. MOST LARGER
VALLEYS...SUCH AS THE HUDSON VALLEY...SHOULD ONLY SEE LIQUID
PRECIP...AS TEMPS LOOK TO BE ABOVE FREEZING DURING THE TIME OF
PRECIP. THE STORM/S COLD FRONT MAY ALLOW FOR SOME ADDITIONAL RAIN
SHOWERS DURING THE DAY ON THURSDAY...ALTHOUGH PRECIP WILL LIKELY BE
RATHER SPOTTY...AS THE BEST FORCING WILL BE WELL NORTHWEST OF THE
AREA AND THERE WON/T BE A GOOD DEAL OF MOISTURE PRESENT. MAX TEMPS
WILL BE ABOVE NORMAL...WITH 40S TO LOW 50S ACROSS THE AREA AHEAD OF
THE BOUNDARY.
BEHIND THIS FRONT...COLDER AIR WILL BEGIN TO MOVE TOWARDS THE REGION
ON FRIDAY. ALTHOUGH THE CORE OF THE COLD AIR WILL REMAIN OVER THE
NORTHERN PLAINS INITIALLY...TEMPS WILL TURN PROGRESSIVELY COLDER
THROUGH THE UPCOMING WEEKEND...WITH TEMPS NEAR OR SLIGHTLY BELOW
NORMAL BY SUNDAY. THE COLD FRONT THAT MOVED THROUGH THE REGION ON
THURSDAY WILL STALL SOUTH OF THE AREA ACROSS THE MID ATLANTIC STATES
FOR LATE IN THE WEEK. WAVES OF LOW PRESSURE MAY DEVELOP ALONG THIS
BOUNDARY AND RIDE NORTHEASTWARD ALONG IT. IF THIS FRONT REMAINS
CLOSE ENOUGH TO OUR AREA...SOME RAIN OR SNOW MAY BE POSSIBLE...ESP
FOR THE SOUTHERN HALF OF THE AREA. THE MODELS ARE UNCLEAR EXACTLY
WHERE OR IF THIS FRONT WILL STALL...AND JUST HOW COLD IT WILL BE
OVER OUR AREA. FOR NOW...WILL GO WITH CHC POPS FOR THURSDAY NIGHT
THROUGH FRIDAY NIGHT...WITH SLIGHT CHC/LOW CHC POPS FOR SAT...WITH
PRECIP RAIN OR SNOW...AND PTYPE BASED ON ELEVATION/DIURNAL TEMP
TRENDS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SCT-BKN CIGS WITH AN OCCASIONAL REDUCTION IN VISIBILITY DUE TO
MIST/BR BUT REMAINING MVFR FLIGHT CATEGORIES ARE ANTICIPATED.
WHILE MOST OF THE TIME WILL BE DRY...A COUPLE OF OPPORTUNITIES FOR A
BRIEF LIGHT SNOW SHOWER OVERNIGHT AND ONCE AGAIN THIS AFTERNOON.
OTHERWISE...DUE TO LIMITED MOISTURE AND WEAK FORCING NOTHING
EXPECTED TO BE ORGANIZED.
WINDS WILL BE CALM OVERNIGHT...AND BECOME LIGHT OUT OF THE S-SE ON
MONDAY...GENERALLY AT LESS THAN 5 KTS.
OUTLOOK...
MON NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
WED NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA. CHC FZRA
MAINLY ACROSS THE HIGHER TERRAIN.
THU: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS.
ANY PRECIPITATION WILL BE LIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV
NEAR TERM...FRUGIS/HWJIV
SHORT TERM...IAA/HWJIV
LONG TERM...FRUGIS
AVIATION...BGM
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1159 PM EST SUN DEC 1 2013
.SYNOPSIS...
A WEAK UPPER LEVEL DISTURBANCE WILL ALLOW FOR PLENTY OF CLOUDS
OVERNIGHT...ALONG WITH THE POSSIBILITY OF SOME LIGHT SNOW SHOWERS
AND OR PATCHY LIGHT FREEZING DRIZZLE THROUGH THE EARLY MORNING
HOURS. THEN MAINLY DRY CONDITIONS WILL PREVAIL THROUGHOUT THE DAY
WITH SEASONABLE TEMPERATURES. TEMPERATURES WILL BECOME ABOVE NORMAL
TOWARDS THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF MIDNIGHT...KENX RADAR WAS PICKING UP SOME LIGHT RETURNS
HEADING INTO THE CAPITAL REGION. HAD ONE REPORT OFF FACEBOOK OF
LIGHT SNOW CHANGING TO LIGHT FREEZING DRIZZLE BUT THEN BACK TO LIGHT
SNOW TO THE WEST OF THE HUDSON VALLEY.
THE ATMOSPHERE WAS SATURATING UP AS EXPECTED EARLIER.
NOT SURE IT WOULD JUST BE PATCHY FREEZING DRIZZLE THAT WOULD FALL
WITH THE RETURNS. CLOUD DECKS ARE ELEVATED AND ACCORDING TO OUR
SOUNDING...COULD SUPPORT LIGHT SNOW OR FREEZING DRIZZLE.
FOR THIS UPDATE...JUST ASSIGNED A 20 POP TO ALL OF THE
REGION...WHILE KEEP 30 POPS WEST OF THE HUDSON VALLEY. ALSO...ADDED
LIGHT SNOW SHOWERS TO ALL AREAS (ALONG WITH THE PATCHY LIGHT
FREEZING DRIZZLE). HOWEVER...MANY AREAS WILL LIKELY REMAIN DRY WITH
NO PRECIPITATION. IT WILL BE A HIT A MISS SCENARIO.
NO REAL CHANGES TO OVERNIGHT TEMPS. WITH THE CLOUDS...THEY SHOULD BE
PRETTY CLOSE TO AROUND 30 FOR AN OVERNIGHT LOW REGION WIDE (A LITTLE
COLDER IN THE MOUNTAINS).
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
THE LATEST HRRR DID INDICATE THE BEST CHANCES OF LIGHT PRECIPITATION
IN THE CAPITAL REGION WOULD BE UNFORTUNATELY AROUND THE MORNING
DRIVE. WHILE NOT TOTALLY BUYING INTO THIS IDEA...WE DID CONTINUE
SLIGHT CHANCES FOR PATCHY LIGHT FREEZING DRIZZLE AND OR LIGHT SNOW
SHOWER INTO THE MORNING HOURS. AFTER THAT TIME...THE WEAK SYSTEM
SHOULD MOVE ON BUY. CLOUDS COULD THIN ENOUGH FOR A BREAK OR TWO OF
SUNSHINE.
OUR REGION WILL REMAIN BETWEEN SYSTEMS. CLOUDS WILL DOMINATE INTO
TUESDAY. TEMPERATURES ARE EXPECTED TO CONTINUED TO BE SEASONABLE.
THE LONGWAVE TROUGH OVER THE REGION WILL DEEPEN BECOMING NEGATIVELY
TILTED OFF NEW ENGLAND COAST TUESDAY. THE MODEL GUIDANCE IS IN MUCH
BETTER AGREEMENT AND DEVELOP A LOW OFF THE SOUTHEAST COAST MONDAY
THEN TRACK IN NORTHEASTWARD AND KEEPING IT WELL OFFSHORE. IT IS
EXPECTED TO REACH NOVA SCOTIA TUESDAY NIGHT. SOME RIDGING WILL
BUILD IN AT ALL LEVELS TUESDAY NIGHT AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A STORM SYSTEM WILL BE MOVING FROM THE GREAT LAKES ON WEDNESDAY
EVENING TOWARDS JAMES BAY FOR THURSDAY.
THIS STORM/S WARM FRONT LOOKS TO MOVE ACROSS OUR REGION ON WED
NIGHT...WITH STRONG WARM AIR ADVECTION TAKING PLACE. 850 HPA TEMPS
WILL SURGE AS HIGH AS +9 ACROSS OUR REGION BY THURSDAY MORNING.
ALTHOUGH MOISTURE WILL BE LIMITED...SOME LIGHT PRECIPITATION IS
EXPECTED OVERNIGHT...ESP FOR THE NORTHERN AND WESTERN PARTS OF THE
AREA. WITH THE WARMING TEMPS ALOFT...PRECIP WILL EITHER BE RAIN OR
FREEZING RAIN...WITH PTYPE DEPENDENT ON SURFACE TEMPS. MOST AREAS
LOOK TO HAVE LOW TEMPS IN THE UPPER 20S TO MID 30S IN THE EVENING
JUST BEFORE OR AT THE START OF WHEN PRECIP BEGINS...WITH TEMPS
RAPIDLY WARMING OVERNIGHT THROUGH THE 30S AND EVEN INTO THE 40S FOR
SOME AREAS. SOME SHELTERED ELEVATED VALLEYS OF THE ADIRONDACKS MAY
HANG ON TO THE SUB FREEZING AIR THE LONGEST...AND THIS IS WHERE THE
BEST THREAT FOR ANY FREEZING RAIN WILL BE. MOST LARGER
VALLEYS...SUCH AS THE HUDSON VALLEY...SHOULD ONLY SEE LIQUID
PRECIP...AS TEMPS LOOK TO BE ABOVE FREEZING DURING THE TIME OF
PRECIP. THE STORM/S COLD FRONT MAY ALLOW FOR SOME ADDITIONAL RAIN
SHOWERS DURING THE DAY ON THURSDAY...ALTHOUGH PRECIP WILL LIKELY BE
RATHER SPOTTY...AS THE BEST FORCING WILL BE WELL NORTHWEST OF THE
AREA AND THERE WON/T BE A GOOD DEAL OF MOISTURE PRESENT. MAX TEMPS
WILL BE ABOVE NORMAL...WITH 40S TO LOW 50S ACROSS THE AREA AHEAD OF
THE BOUNDARY.
BEHIND THIS FRONT...COLDER AIR WILL BEGIN TO MOVE TOWARDS THE REGION
ON FRIDAY. ALTHOUGH THE CORE OF THE COLD AIR WILL REMAIN OVER THE
NORTHERN PLAINS INITIALLY...TEMPS WILL TURN PROGRESSIVELY COLDER
THROUGH THE UPCOMING WEEKEND...WITH TEMPS NEAR OR SLIGHTLY BELOW
NORMAL BY SUNDAY. THE COLD FRONT THAT MOVED THROUGH THE REGION ON
THURSDAY WILL STALL SOUTH OF THE AREA ACROSS THE MID ATLANTIC STATES
FOR LATE IN THE WEEK. WAVES OF LOW PRESSURE MAY DEVELOP ALONG THIS
BOUNDARY AND RIDE NORTHEASTWARD ALONG IT. IF THIS FRONT REMAINS
CLOSE ENOUGH TO OUR AREA...SOME RAIN OR SNOW MAY BE POSSIBLE...ESP
FOR THE SOUTHERN HALF OF THE AREA. THE MODELS ARE UNCLEAR EXACTLY
WHERE OR IF THIS FRONT WILL STALL...AND JUST HOW COLD IT WILL BE
OVER OUR AREA. FOR NOW...WILL GO WITH CHC POPS FOR THURSDAY NIGHT
THROUGH FRIDAY NIGHT...WITH SLIGHT CHC/LOW CHC POPS FOR SAT...WITH
PRECIP RAIN OR SNOW...AND PTYPE BASED ON ELEVATION/DIURNAL TEMP
TRENDS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
WITH THE APPROACH OF AN UPPER LEVEL DISTURBANCE...THERE WILL BE
PLENTY OF CLOUDS TONIGHT. BKN-OVC CIGS OF 8-10 KFT WILL LOWER TO
AROUND 6 KFT BY AROUND MIDNIGHT OR SO. THERE MAY BE A PERIOD OF MVFR
CIGS FOR LATE TONIGHT INTO MONDAY MORNING...BUT IFR CONDITIONS ARE
NOT ANTICIPATED. BKN-OVC CLOUDS WILL CONTINUE INTO THE DAY ON MONDAY.
IT LOOKS TO REMAIN DRY AS WELL...ALTHOUGH A BRIEF SNOW SHOWER IN
THE VICINITY OF KGFL CANNOT BE RULED OUT OVER THE NEXT FEW HOURS.
OTHERWISE...NO PRECIP IS EXPECTED DUE TO LIMITED MOISTURE AND WEAK
FORCING.
WINDS WILL BE CALM OVERNIGHT...AND BECOME LIGHT OUT OF THE S-SE ON
MONDAY...GENERALLY AT LESS THAN 5 KTS.
OUTLOOK...
MON NIGHT-WED: NO OPERATIONAL IMPACT. NO SIG WX.
WED NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA. CHC FZRA
MAINLY ACROSS THE HIGHER TERRAIN.
THU: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS.
ANY PRECIPITATION WILL BE LIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/HWJIV
NEAR TERM...FRUGIS/HWJIV
SHORT TERM...IAA/HWJIV
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
427 AM EST MON DEC 2 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE CAROLINA COAST THIS MORNING
AND LIFT NORTHEAST TODAY...WHILE GENERALLY DRY HIGH PRESSURE PREVAILS
OVER THE AREA THROUGH LATE WEEK. A COLD FRONT SHOULD THEN SHIFT OVER
THE AREA DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...SATELLITE IMAGERY THIS MORNING PORTRAYS A TEXTBOOK BAROCLINIC
LEAF SIGNATURE OVER THE SE UNITED STATES AS WEAK CYCLOGENESIS IS
UNDERWAY ALONG THE WEST WALL OF THE GULF STREAM. UNDER THE LEAF OF
THICK MID AND HIGH CLOUDS...SURFACE CONDITIONS WERE RAIN-FREE ACROSS
CENTRAL GEORGIA AS PCPN FALLS INTO A VERY DRY LAYER BETWEEN 5-16 KFT.
LIGHT RADAR RETURNS MAINLY VIRGA AT THIS POINT WITH OTHER RAINS
BREAKING OUT IN NW GEORGIA AND EASTERN ALABAMA AS MODELS INDICATED.
UPPER FORCING/PVA COULD RESULT IN SOME SPRINKLES OR SPOTTY LIGHT
SHOWERS AT SOME LOCATIONS THROUGH MID MORNING. AT THIS POINT...
MEASURABLE RAINFALL CHANCES LOOK QUITE SMALL AND OUR POPS SILENT.
TEMPS MILD 50-53...FALLING INTO THE 40S LATE.
THE PROGRESSIVE UPPER WAVE WILL SWEEP OFF THE COAST BY MIDDAY WITH
CLOUDS QUICKLY CLEARING OUT FOR THE AFTERNOON ACROSS THE FORECAST
AREA. FORECAST VERTICAL MOISTURE PROFILES DRY OUT FAST AND MODEL
CLOUD FORECAST PROGS SUCH AS THE REGIONAL GEM INDICATE SUNSHINE
SHOULD BE PREVALENT DURING THE AFTERNOON HOURS. IN THE WAKE OF
THE OFFSHORE LOW PRES...LOW LEVEL WINDS WILL BECOME W TO WNW AND
THIS WILL ALLOW FOR A LOWER RISK FOR MANY LINGERING LOWER CLOUDS BY
EARLY AFTERNOON. LACK OF SIGNIFICANT COLD AIR ADVECTION AND THE WEAK
DOWNSLOPE COMPONENT SHOULD ALLOW HIGH TEMPS TO REACH THE MID 60S
MOST AREAS PROVIDED THE CLOUDS SCATTER OUT EARLIER OR ON TIME...
RATHER THAN LATER. INCREASING LAYERED CLOUDS EXPECTED TONIGHT WITH
LOWS IN THE 40S AND WITH JUST SPRINKLE CHANCES...POPS SILENT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
QUIET/DRY WEATHER IS EXPECTED THROUGH MIDWEEK AS WEAK HIGH PRESSURE
SETTLES OVER THE AREA BEHIND A DEPARTING SFC LOW WELL TO OUR
NORTHEAST. MODELS CONTINUE TO INDICATE A FAIRLY SIGNIFICANT WARMING
TREND THROUGH THROUGH THURSDAY AS SOUTHERLY FLOW DEVELOPS ALONG THE
WESTERN EDGE OF SFC HIGH PRESSURE WHILE SLIGHT MID LVL RIDGING
OCCURS FROM THE SOUTH/SOUTHWEST. HOWEVER...PEAK HEATING MAY BE
LIMITED A FEW DEGREES EACH DAY DUE TO CIRRUS THAT DEVELOPS WITH A
STRONG H25 JET POSITIONED JUST TO THE NORTHWEST OR MID CLOUDS
ASSOCIATED WITH MODEST ISENTROPIC OVER THE AREA. DESPITE CLOUD
COVER...PERSISTENT SOUTHERLY FLOW WILL LIKELY WARM OVERALL HIGH
TEMPS INTO THE UPPER 60S TO AROUND 70 ON TUESDAY...THEN LOW 70S ON
WEDNESDAY...FOLLOWED BY MID/UPPER 70S BY THURSDAY. OVERNIGHT LOWS
WILL ALSO REMAIN MILD EACH NIGHT...IN THE LOW/MID 50S INLAND TO
UPPER 50S/LOWER 60S ALONG THE IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CONDITIONS WILL REMAIN QUIET/DRY THROUGH FRIDAY AS THE AREA REMAINS
SITUATED ALONG THE WESTERN EDGE OF SFC HIGH PRESSURE. PERSISTENT
SOUTHERLY FLOW ALONG WITH MID LVL RIDGING FROM THE SOUTH/SOUTHWEST
WILL LIKELY LEAD TO ABOVE NORMAL TEMPS AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST. IN GENERAL...EXPECT HIGH TEMPS IN THE
UPPER 70S ON FRIDAY WITH OVERNIGHT LOWS IN THE UPPER 50S/LOWER 60S.
PRECIP CHANCES SHOULD THEN INCREASE THIS WEEKEND AS A COLD FRONT
BEGINS SHIFTING THROUGH THE SOUTHEASTERN UNITED STATES. UNCERTAINTY
REMAINS HIGH WITH THE POSITION OF THE FRONT ON SATURDAY AND SUNDAY
BUT THE GENERAL CONSENSUS IS THAT THE FRONT SHOULD STALL JUST SOUTH
OF THE FORECAST AREA BEFORE LIFTING NORTH AS A WARM FRONT AHEAD OF
SFC LOW SHIFTING OVER THE DEEP SOUTH AND THEN THE SOUTHEASTERN UNITED
STATES EARLY NEXT WEEK. HAVE THUS MAINTAINED CHANCE POPS SATURDAY
AND SUNDAY AS MOISTURE REMAINS ALONG/NEAR THE FRONT. A SLIGHT CHANCE
OF SHOWERS WILL ALSO BE POSSIBLE ON MONDAY WHILE CONDITIONS
GRADUALLY IMPROVE WITH THE LOW SHIFTING OFFSHORE. OVERALL HIGH TEMPS
SHOULD PEAK NEAR 70 ON SATURDAY AHEAD OF THE FRONT...THEN COOL OFF
INTO THE LOW 60S ON SUNDAY AND MONDAY AS THE SFC LOW SHIFTS OVER THE
SOUTHEAST AND OFFSHORE.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS IFR AT 06Z AND LATEST RAP SOUNDINGS SUGGEST CIGS MAY
LOWER A BIT MORE BEFORE IMPROVING TOWARD DAYBREAK AS A LIGHT
NW FLOW DEVELOP. UPSTREAM CIGS OVER INLAND AREAS ARE CURRENTLY
VFR WITH MVFR VSBYS. WE IMPROVE CONDITIONS MID MORNING THEN VFR
CONDITIONS BY LATE MORNING THROUGH THIS EVENING.
KSAV...MVFR OR IFR CIGS IN AND OUT UNDER A STRONG INVERSION BUT
CONDITIONS SHOULD IMPROVE BY MID MORNING AND VFR WILL PERSIST FOR
THE REMAINDER OF THE DAY INTO THIS EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL THROUGH
FRIDAY. MVFR CIGS/VSBYS ARE POSSIBLE SATURDAY AS SHOWERS OCCUR ALONG
A PASSING COLD FRONT.
&&
.MARINE...
A LIGHT NW FLOW IS FORECAST IN THE WAKE OF AN OFFSHORE LOW RACING
TO THE NE TODAY. A WEAK GRADIENT SHOULD ENSURE A LACK OF ANY
SIGNIFICANT SURGES AFTER MID MORNING. SEAS ALSO CONTINUE TO SLOWLY
SUBSIDE. SEAS 3 TO 4 FT COMING DOWN TO 2 TO 3 FT BY TONIGHT.
TUESDAY THROUGH SATURDAY...WINDS/SEAS WILL REMAIN WELL BELOW SMALL
CRAFT ADVISORY LEVELS AS A SFC LOW CONTINUES TO SHIFT NORTHEAST AND
AWAY FROM THE REGION THROUGH TUESDAY. WEAK HIGH PRESSURE WILL THEN
SETTLE OVER THE WATERS THROUGH THURSDAY WITH WINDS/SEAS EXPECTED TO
REMAIN AT OR BELOW 15 KT WITH SEAS NO HIGHER THAN 3 FT. WINDS/SEAS
WILL THEN GRADUALLY INCREASE/BUILD TO 15-20 KT AND 4-5 FT ON FRIDAY
AS THE PRESSURE GRADIENT BEGINS TO ENHANCE BETWEEN HIGH PRESSURE
OVER THE WESTERN ATLANTIC AND A COLD FRONT APPROACHING INLAND.
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
SATURDAY AS THE COLD FRONT STALLS OVER OR JUST SOUTH OF THE WATERS.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE HIGH THROUGH MID-WEEK DUE TO ASTRONOMICAL
INFLUENCES OF THE UPCOMING PERIGEE AND NEW MOON /PERIGEAN SPRING
TIDES/. THE TIDE AROUND 7 AM THIS MORNING IN DOWNTOWN CHARLESTON
WILL BE CLOSE TO 7 FT MLLW BUT WE DECIDED TO HOLD OFF ON A COASTAL
FLOODING ADVISORY AS THE WEAK LOW LEVEL FLOW HAS TURNING OFFSHORE
AND DEPARTURES APPEAR TO ON THEIR WAY DOWN. IT CERTAINLY APPEARS
VERY MARGINAL AT THIS POINT BUT WE WILL BE WATCHING TRENDS THE
NEXT FEW HOURS NEARING HIGH TIDE. COASTAL FLOOD ADVISORIES MIGHT
BE NEEDED TUESDAY MORNING AND AGAIN WEDNESDAY MORNING WITH THOSE
HIGH TIDES AS WELL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
120 AM EST MON DEC 2 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEAKEN WHILE A COASTAL TROUGH LINGERS
OFFSHORE. AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST
COAST EARLY MONDAY AND LIFT NORTH/NORTHEAST THROUGH MID WEEK...WHILE
GENERALLY DRY HIGH PRESSURE PREVAILS OVER THE AREA THROUGH LATE
WEEK. A COLD FRONT SHOULD THEN SHIFT OVER THE AREA DURING THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE INLAND WEDGE OF HIGH PRESSURE WILL CONTINUE TO ERODE TONIGHT...
WHILE A COASTAL TROUGH LINGERS OFFSHORE. MEANWHILE...A NEARLY
ZONAL FLOW WILL PREVAIL ALOFT THROUGH MOST OF THE NIGHT...UNTIL A
MID LEVEL PERTURBATION IN THE LOWER MISSISSIPPI VALLEY THIS
EVENING PASSES THROUGH LATE TONIGHT AND INDUCES WEAK CYCLOGENESIS
OFF THE SOUTH CAROLINA COAST ALONG THE TROUGH AXIS OUT NEAR THE
GULF STREAM.
MODEL SOUNDINGS INDICATE THAT A SUBSIDENCE INVERSION WILL KEEP
MOISTURE TRAPPED IN THE LOW LEVELS OF THE ATMOSPHERE. WHILE AT
FIRST GLANCE THIS MIGHT LEAD TO SOME FOG FORMATION. BUT GIVEN
EXTENSIVE AND MOSTLY OPAQUE HIGH LEVEL CLOUD COVER WITH A 120-150
KT UPPER JET MOVING THROUGH THE SE AND TENNESSEE VALLEY AND
CONDENSATION PRESSURE DEFICITS NO LOWER THAN ABOUT 30
MILLIBARS...WE HAVE REFRAINED FROM INCLUDING ANY FOG IN THE
FORECAST. AS THE JET DROPS A LITTLE FURTHER SOUTH LATE TONIGHT
THERE WILL BE A LITTLE THINNING AND DISSIPATING OF THE HIGHER
CLOUDS OVER NORTHERN ZONES. THIS MAY ALLOW FOR A LITTLE FOG TO
SNEAK IN LATE...BUT PROBABILITIES ARE NOT HIGH ENOUGH TO ADD TO
THE FORECAST. A WORSE CASE SCENARIO WOULD BE IN LOW STRATUS/FOG
DEVELOP UPSTREAM AND ADVECT IN WITH THE NW AND NORTH FLOW CLOSER
TO DAYBREAK. THIS SEEMS UNLIKELY THOUGH AT THIS STAGE.
ISENTROPIC UPGLIDE IS WEAK AND DIMINISHES WITH TIME...THUS THE
RISK FOR ANY LIGHT PRECIP IS EXTREMELY SMALL. ALTHOUGH THE
PROXIMITY TO THE COASTAL TROUGH AND DEVELOPING LOW OVER THE
ATLANTIC IT CANNOT BE ENTIRELY RULED OUT ACROSS CHARLESTON AND
BERKELEY COUNTY VERY LATE TONIGHT.
LOW TEMPERATURES TONIGHT WILL BE A TAD ABOVE NORMALS FOR THE
FIRST WEEK OF DECEMBER...RANGING FROM THE LOWER 40S ALONG NW
SECTIONS...MIDDLE AND UPPER 40S MOST ELSEWHERE...EXCEPT CLOSER TO
50 ON THE BARRIER ISLANDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
MONDAY...A SHORTWAVE TROUGH WILL RAPIDLY CROSS THE EAST COAST DURING
THE MORNING HOURS...PROVIDING THE NECESSARY ENERGY TO ORGANIZE A
WAVE OF LOW PRESSURE OFF THE CAROLINA COASTLINE. AS THE SHORTWAVE
MOVES QUICKLY INTO THE ATLANTIC WATERS...THE INTENSIFYING COASTAL
LOW WILL PULL NORTHEAST TO FOLLOW THE UPPER LEVEL FEATURE. DESPITE
THE PRESENCE OF SHORTWAVE ENERGY EARLY IN THE DAY...SOLID
WEST/NORTHWEST FLOW THROUGHOUT THE COLUMN AND WEAK HIGH PRESSURE
BEHIND THE COASTAL LOW WILL LIKELY SUPPRESS PRECIPITATION POTENTIAL.
NUMERICAL MODELS HAVE BEEN TRENDING DRIER FOR MONDAY...AND HAVE THUS
DECREASED RAIN CHANCES BELOW 15 PERCENT ALL AREAS ACCORDINGLY. THICK
CLOUD COVER WILL PREVAIL...YET DOWNSLOPE FLOW WILL SUPPORT SLIGHTLY
WARMER TEMPERATURES THAN THE PREVIOUS DAYS. HIGH TEMPERATURES WILL
REACH THE MID TO UPPER 60S...WITH LOWS IN THE 40 DEGREE RANGE.
TUESDAY AND WEDNESDAY...WEAK HIGH PRESSURE WILL GENERALLY PREVAIL
ACROSS THE SOUTHEAST STATES...WHILE PROGRESSIVE ZONAL FLOW ALOFT
ON TUESDAY TRANSITIONS INTO UPPER RIDGING BY WEDNESDAY. ANY
NOTABLE ENERGY ALOFT WILL REMAIN NORTH AND SOUTH OF THE FORECAST
AREA DURING THE PERIOD...WITH BEST PRECIPITATION POTENTIAL
CONFINED WEST OF THE AREA NEAR A DEVELOPING COLD FRONT OVER THE
OHIO/TENNESSEE VALLEYS. THUS WILL CONTINUE TO CAP RAIN CHANCES
BELOW 15 PERCENT INTO THE MID WEEK PERIOD. GRADUALLY RISING
HEIGHTS ALOFT...FLOW BECOMING MORE SOUTH/SOUTHWEST...AND LESS
CLOUD COVER WILL ALLOW THE WARMING TREND TO CONTINUE. HIGH
TEMPERATURES WILL PEAK IN THE UPPER 60S TUESDAY AND AROUND 70
WEDNESDAY AFTERNOON. LOW TEMPERATURES WILL ALSO BECOME MORE
MILD...ONLY FALLING TO AROUND 50 DEGREES AS DEWPOINTS STEADILY
RISE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
CONDITIONS WILL REMAIN QUIET/DRY THROUGH LATE WEEK AS THE AREA
REMAINS SITUATED ALONG THE WESTERN EDGE OF SFC HIGH PRESSURE.
PERSISTENT SOUTHERLY FLOW ALONG WITH MID LVL RIDGING FROM THE
SOUTHWEST WILL LIKELY LEAD TO A WARMING TREND OVER THE AREA
THROUGH LATE WEEK. IN GENERAL...HIGH TEMPS SHOULD WARM TO AROUND
70 ON THURSDAY...THEN MID 70S ON FRIDAY. OVERNIGHT LOWS SHOULD
RANGE IN THE UPPER 40S INLAND TO MID 50S ALONG THE COAST WEDNESDAY
NIGHT...THEN LOW 50S INLAND TO UPPER 50S ALONG THE COAST THURSDAY
NIGHT.
PRECIP CHANCES SHOULD THEN INCREASE THIS WEEKEND AS A COLD FRONT
BEGINS SHIFTING THROUGH THE SOUTHEASTERN UNITED STATES. HAVE
INTRODUCED CHANCE POPS OVER ALL LOCATIONS ON SATURDAY AND SUNDAY
WHEN COLD FROPA IS ANTICIPATED. OVERALL HIGH TEMPS SHOULD RANGE IN
THE MID/UPPER 60S ON SATURDAY AS CLOUD COVER AND PRECIP COVERAGE
INCREASE. AFTERNOON HIGH TEMPS WILL CONTINUE TO COOL DOWN INTO THE
LOW 60S ON SUNDAY AS THE FRONT SHIFTS OFFSHORE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS IFR AT 06Z AND LATEST RAP SOUNDINGS SUGGEST CIGS MAY
LOWER A BIT MORE BEFORE IMPROVING TOWARD DAYBREAK AS A LIGHT
NW FLOW DEVELOP. UPSTREAM CIGS OVER INLAND AREAS ARE CURRENTLY
VFR WITH MVFR VSBYS. WE IMPROVE CONDITIONS MID MORNING THEN VFR
CONDITIONS BY LATE MORNING THROUGH THIS EVENING.
KSAV...MVFR OR IFR CIGS COULD DEVELOP THE NEXT FEW HOURS UNDER
A STRONG INVERSION BUT CONDITIONS SHOULD IMPROVE BY MID MORNING
AND VFR WILL PERSIST FOR THE REMAINDER OF THE DAY INTO THIS EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL THROUGH
LATE WEEK. MAYBE SOME FOG POTENTIAL DURING THE EARLY MORNINGS
WEDNESDAY AND AGAIN THURSDAY.
&&
.MARINE...
TONIGHT...THE BEST PRESSURE FALLS CONTINUE TO BE FOUND EAST AND NE
OF CHARLESTON...AND RADAR TRENDS SHOWING SOME FLARE-UP OF SHOWERS
OUT NEAR THE WEST WALL OF THE GULF STREAM. THIS IS INDICATIVE THAT
A WEAK LOW IS STARTING TO FORM ALONG THE COASTAL TROUGH. NORTH
WINDS WILL BACK AROUND TO THE NW AS THIS FEATURE FORMS AND LAND
BREEZE CIRCULATIONS SET IN OVERNIGHT. SPEEDS COULD INCREASE A HAIR
OVER THE AMZ350 WATERS AS THE PRESSURE GRADIENT AROUND THE LOW
TIGHTENS...BUT OVERALL WINDS WILL BE NO HIGHER THAN ABOUT 10 OR 15
KT IN THE ATLANTIC AND 5 KT IN CHARLESTON HARBOR. SEAS HAVE
FINALLY FALLEN ENOUGH WHERE WE HAVE DROPPED THE SCA FOR
AMZ374...AND SEAS TONIGHT WILL BE NO MORE THAN 3-5 FT...A LITTLE
LESS NEAR THE IMMEDIATE COAST.
MONDAY THROUGH FRIDAY...WINDS/SEAS WILL REMAIN WELL BELOW SMALL
CRAFT ADVISORY LEVELS...AS A SURFACE LOW DEEPENS OFFSHORE ON
MONDAY AND LIFTS NORTHEAST AND AWAY FROM THE REGION THROUGH
TUESDAY. WEAK HIGH PRESSURE WILL THEN SETTLE OVER THE WATERS
THROUGH THURSDAY...WITH WINDS EXPECTED TO REMAIN AT OR BELOW
10-15 KT AND SEAS FALLING TO 3 FT OR LESS BY LATE MONDAY.
WINDS/SEAS WILL THEN GRADUALLY INCREASE/BUILD TO 15-20 KT AND 4-5
FT ON FRIDAY...AS THE PRESSURE GRADIENT BEGINS TO TIGHTEN BETWEEN
HIGH PRESSURE OVER THE WESTERN ATLANTIC AND A COLD FRONT
APPROACHING INLAND.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE HIGH THROUGH MID-WEEK DUE TO ASTRONOMICAL
INFLUENCES OF THE UPCOMING PERIGEE AND NEW MOON /PERIGEAN SPRING
TIDES/. IT/LL ONLY TAKE A SMALL DEPARTURE TO GENERATE SHALLOW
COASTAL FLOODING WITH THE NEXT HIGH TIDE ALONG THE CHARLESTON
COUNTY AND LOWER COLLETON COUNTY COASTS...AND A COASTAL FLOOD
ADVISORY MIGHT BE REQUIRED FOR THE HIGH TIDE JUST BEFORE 7 AM
MONDAY. ADDITIONAL COASTAL FLOOD ADVISORIES MIGHT BE NEEDED
TUESDAY MORNING AND AGAIN WEDNESDAY MORNING WITH THOSE HIGH TIDES
AS WELL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...WMS
LONG TERM...DPB
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
1231 AM EST MON DEC 2 2013
.UPDATE...
/ISSUED AT 951 PM EST SUN DEC 1 2013/
NO CHANGES PLANNED AT THIS TIME. THERE REMAINS SOME UNCERTAINTY AS
TO WHERE THE LIGHT RAIN WILL IMPACT THE FORECAST AREA...TIMING
AROUND AND JUST AFTER MORNING RUSH HOUR LOOKS GOOD...CONFIDENCE IS
STILL TOO LOW TO MAKE ANY CHANGES.
&&
.PREV DISCUSSIONS... /ISSUED 214 PM EST SUN DEC 1 2013/
SHORT TERM /TONIGHT THROUGH TUESDAY/...
LATEST SURFACE ANALYSIS OVER THE SOUTHEAST UNITED STATES SHOWS
WEAK HIGH PRESSURE CONTINUING TO BE THE DOMINATING INFLUENCE OF
THE LOCAL WX. EAST AND SOUTHEAST FLOW ON SOUTHERN PERIPHERY OF
THIS HIGH EARLIER ALLOWED FOR LOW LEVEL MOISTURE TO ADVECT IN A
RESULT IN WIDESPREAD LOW CLOUDS. SINCE THEN...DEVELOPING
SOUTHWEST FLOW DUE TO A SHIFT IN THE HIGH POSITION HAS ALLOWED
FOR THE EROSION OF MOST OF THE LOW CLOUDS BUT HAS QUICKLY BEEN
REPLACED BY A THIN VEIL OF CIRRUS. TEMPS LOOKS TO BE LARGELY
UNAFFECTED BY THIS AS WE ARE ALREADY WITHING THREE DEGREES OF
FORECAST HIGH OF ATLANTA CURRENTLY.
FOR TONIGHT...THE FIRST IN A SERIES OF EMBEDDED SHORTWAVES WILL
MOVE THROUGH ZONAL FLOW TO PRODUCE AN AREA OF MAINLY LIGHT RAIN
OVER ALABAMA. MODELS HAVE BEEN BACKING OFF ON HOW MUCH THIS
ENERGY TRANSLATES INTO ACTUAL PRECIP OVER OUR AREA AND INDEED
FEEL AMOUNTS WILL BE ON THE LOW SIDE EVEN OVER WESTERN PORTIONS.
THAT SAID...BASED ON WRF AND HRRR RUNS...IT SHOULD STILL RAIN
EVEN IF ITS LIGHT AND HAVE UPPED CHANCES ALONG THE WEST CENTRAL
BORDER THROUGH 15Z MONDAY. WILL LET EVENING AND MID SHIFT TAKE
ANOTHER LOOK AS MAY STILL BE TOO LOW...GOING JUST BELOW LIKELY AT
THIS POINT.
WAVE CLEARS DURING THE AFTERNOON BUT ANOTHER WILL BE RIGHT ON ITS
HEELS INTO MONDAY NIGHT. THIS ONE WILL BE MOVING MORE SOUTHWEST
TO NORTHEAST TO AFFECT MAINLY THE NORTHERN TIER WITH MID RANGE
CHANCE POPS. IN ADDITION TO LIGHT RAIN...COULD SEE SOME PATCHY
FOG DEVELOPMENT WITH THIS SYSTEM OVER THE MOUNTAINS AND ALONG OUR
WESTERN BORDER WITH ALABAMA.
INCREASING TEMPERATURES THROUGH THE SHORT TERM WITH MID 60S TO
AROUND 70 EXPECTED BY TUESDAY AFTERNOON. THIS WOULD BE A RADICAL
DEPARTURE FROM THE EXTREME COLD OF THIS PAST WEEK AND WOULD
RESULT IN TEMPS SOME 10 DEGREES ABOVE CLIMO.
DEESE
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
SOME CHANGES MADE TO THE EXTENDED BASED ON GUIDANCE WHICH IS
COMING IN QUITE A BIT WARMER FOR LATER IN THE WEEK. AHEAD OF THE
FRONT PROGGED TO STALL ACROSS THE TENNESSEE VALLEY WHICH WILL
SLOWLY MAKE ITS WAY TO THE SOUTHERN APPALACHIANS BY FRIDAY.
RIDGING IN THE GULF REMAINS PRETTY STRONG BUT ALSO STRONGER LOW-
LEVEL WAA. INCREASED TEMPS QUITE A BIT AND ACTUALLY HAVE NEAR-
RECORD TO RECORD WARM MIN TEMPS FOR FRIDAY MORNING. POPS STILL
LOOKING GOOD BUT WILL PROBABLY HAVE TO INCREASE THEM AS WE
PROGRESS THROUGH THE WEEK.
THERE IS SOME CONCERN ABOUT HAZARDOUS WEATHER AS GFS CAPES ARE ON
THE INCREASE ESPECIALLY FOR FRIDAY AFTERNOON AND SOME QPF VALUES
ARE PRETTY HEFTY...BUT WILL NARROW THAT DOWN AS WE GET CLOSER. A
LOT OF UNCERTAINTY ON TIMING OF FROPA AND SUBSEQUENT CAD ONSET...
ECMWF A LITTLE FASTER THAN THE GFS ON FROPA BUT BOTH HAVE SIMILAR
TIMING WITH CAD ONSET....SO MADE NO CHANGES TO SATURDAY /AS THE
SIGNIFICANT COOL-DOWN STARTS/ AND BEYOND BECAUSE OF THAT
UNCERTAINTY. WILL BE INTERESTING TO SEE WHAT SENSIBLE WEATHER
IMPACTS OCCUR WITH THE DIABATICALLY-ENHANCED CAD EVENT FOR EARLY
NEXT WEEK. SEE PREVIOUS DISCUSSION BELOW.
TDP
&&
.AVIATION...
06Z UPDATE...
CURRENT VFR CIGS WILL LOWER TO MVFR LEVELS BY 10-12Z THIS MORNING AS
AN UPPER DISTURBANCE APPROACHES AND SPREADS PATCHES OF -RA ACROSS
THE AREA THRU AT LEAST THE MORNING HOURS... MAINLY BETWEEN 10-18Z
TODAY ACROSS ATLANTA TAF SITES. CIGS MAY IMPROVE TO VFR LEVELS THIS
AFTERNOON... BUT GUIDANCE SUGGEST THIS MAY BE BRIEF AS MVFR CIGS
SETTLE BACK IN BY 00-03Z THIS EVENING. CURRENT WEST WINDS WILL BACK
SW THIS AFTERNOON... THEN SOUTHERLY TONIGHT...POSSIBLY BECOMING MORE
SSE BY 10-12Z TUE MORN. WIND SPEEDS WILL BE 7KTS OR LESS TODAY...
THEN NEARLY CALM TONIGHT.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON CIGS/WEATHER.
HIGH CONFIDENCE WINDS/VISIBILITY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 56 39 60 48 / 5 10 20 30
ATLANTA 59 45 59 49 / 5 20 50 30
BLAIRSVILLE 56 37 53 45 / 5 10 30 30
CARTERSVILLE 55 40 56 48 / 5 40 40 30
COLUMBUS 63 46 65 50 / 5 20 20 20
GAINESVILLE 54 42 55 48 / 5 10 20 30
MACON 58 42 66 44 / 5 10 20 20
ROME 54 41 56 48 / 0 40 50 30
PEACHTREE CITY 57 40 60 43 / 5 20 50 30
VIDALIA 55 47 66 48 / 5 5 10 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ATWELL/39
LONG TERM....SNELSON
AVIATION...39
AREA FORECAST DISCUSSION
NWS JACKSON KY
105 AM EST MON DEC 2 2013
.UPDATE...
ISSUED AT 105 AM EST MON DEC 2 2013
UPDATED HOURLY TEMPERATURES AND DEWPOINTS. UNLESS CEILINGS CAN COME
DOWN A BIT...DRIZZLE IS LOOKING LESS LIKELY THE REST OF THE NIGHT.
DEW POINT DEPRESSIONS ARE STILL PLENTY HIGH AND HARD TO SEE THAT
CHANGING OVER THE NEXT 3 TO 4 HOURS. THUS...WILL REMOVE THE DRIZZLE
AND STAY WITH A DRY FORECAST THROUGH TOMORROW.
UPDATE ISSUED AT 929 PM EST SUN DEC 1 2013
CLOUDY SKIES WILL PREVAIL DURING THE OVERNIGHT. DRIZZLE IS LOOKING
LESS LIKELY FOR LATE TONIGHT AND EARLY MONDAY MORNING...BUT WILL LEAVE
IT IN THE FORECAST FOR THE SAKE OF CONTINUITY AND CONSISTENCY. HAVE
UPDATED HOURLY NDFD AND WEB FORECASTS BASED ON LATEST TRENDS...AND
MADE A FEW MINOR TEMPERATURE ADJUSTMENTS FOR OVERNIGHT LOWS. NEEDED
TO LOWER MINIMUMS IN SOME VALLEY LOCATIONS WHERE TEMPERATURES ONLY
REACHED THE LOWER 40S ON SUNDAY. THE MESONET AT QUICKSAND IS PROBABLY
THE EXTREME EXAMPLE OF THIS WHERE THE AFTERNOON HIGH WAS ONLY 41 AND
THE 02Z TEMPERATURE WAS 37. THIS IS CONTRASTED TO THE JACKSON
ASOS...ONLY 4 MILES AWAY...WHERE THE HIGH WAS 47 AND THE 02Z TEMPERATURE
WAS 47. NO UPDATE NEEDED FOR THE ZFP AT THIS TIME.
UPDATE ISSUED AT 636 PM EST SUN DEC 1 2013
LOW CLOUDS CONTINUE TO HOLD ACROSS THE AREA...AND WILL LIMIT
TEMPERATURE FALLS THIS EVENING. THE PREVIOUS FORECAST HAD THIS WELL
HANDLED. NDFD WAS UPDATED FOR LATEST HOURLY TRENDS BUT THIS RESULTED
IN ONLY MINOR CHANGES TO THE HOURLY NDFD FORECASTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 338 PM EST SUN DEC 1 2013
A BAND OF LOW CLOUDS REMAINS ACROSS THE REGION IN ADVANCE OF A WEAK
COLD FRONT THAT IS BEGINNING TO SLOW DOWN AND STALL OUT. SOME OF
THESE HAVE ERODED A BIT FROM THE SOUTH OR SOUTHEAST AND NORTHWEST
THROUGHOUT THE DAY. THIS HAS LED TO THE COLDEST TEMPERATURES ON
AVERAGE BETWEEN THE HAL ROGERS PARKWAY AND KY HIGHWAY 80 CORRIDOR AND
INTERSTATE 64 CORRIDOR. SOME OF THE DEEPER SHELTERED VALLEYS NEVER
REALLY MIXED OUT AND TEMPERATURES THERE ARE IN THE LOW TO MID 40S
ATTM. OTHERWISE TEMPS WERE NEAR 50 ACROSS MUCH OF THE SOUTHERN CWA
AND HAD NEARED 50 NORTH OF THE INTERSTATE 64 CORRIDOR.
A WEAK DISTURBANCE IS EXPECTED TO MAINLY PASS TO OUR SOUTH LATER
TONIGHT INTO MONDAY MORNING WHILE A MORE NORTHERN SHORTWAVE WILL
PASS TO THE NORTH OF EASTERN KY ON MONDAY AFTERNOON AND EVENING. THIS
WILL LEAD TO A BRIEF DEVELOPMENT OF A SOUTHEASTERN TROUGH BY MONDAY.
THIS TROUGH WILL MOVE ON OFF TO THE EAST WITH SOME WEAK RIDGING
PASSING THROUGH OVER THE SOUTHEASTERN US AND TN VALLEY FOR MON NIGHT
INTO TUE. AT THE END OF THE PERIOD...A TROUGH IS ANTICIPATED TO
EXTEND FROM CENTRAL CANADA INTO THE NORTHERN PLAINS AND THEN
SOUTHWEST INTO THE ROCKIES AND CALIFORNIA WITH MORE OR LESS ZONAL
FLOW IN THE EASTERN CONUS.
AS AT THE SFC...THE BOUNDARY TO OUR NORTHWEST SHOULD STALL NEAR THE
OH RIVER TONIGHT AND INTO MONDAY BEFORE RETURNING NORTH AS A WARM
FRONT LATER ON MONDAY INTO TUESDAY. MODELS INDICATE A GENERAL
GRADUAL INCREASE IN MOISTURE BELOW THE CURRENT CLOUD LAYER
TONIGHT...BUT MEAGER OMEGA AT BEST. UP UNTIL TODAY AT LEAST...MODELS
SEEM TO HAVE BEEN TOO AGGRESSIVE INCREASING LOW LEVEL MOISTURE.
HOWEVER...DEWPOINTS HAVE CREPT UP INTO THE MID TO UPPER 30S IN
WESTERN AND CENTRAL KY AND MIDDLE AND WESTERN TN. THIS LEADS TO
UNCERTAINTY AS TO WHETHER OR NOT THE STRATOCU DECK COULD LOWER LATER
TONIGHT INTO EARLY ON MONDAY AND WHETHER OR NOT THERE COULD BE SOME
PATCHY DRIZZLE AT THAT TIME. THE 12Z NAM AND 12Z GFS HAD SOME LIGHT
SPOTTY QPF WITH THIS LATE TONIGHT OR MONDAY. THE 18Z HRRR ALSO HAD
SOME LIGHT SPOTTY QPF LATER TONIGHT. THE 15Z SREF POPS ARE LOW AND
HAVE TRENDED DOWN SINCE 24 HOURS AGO. OPTED TO GO WITH A 10 POP FOR
PATCHY DRIZZLE IN ALL BUT THE FAR SOUTHEAST LATE TONIGHT AND INTO
MONDAY MORNING AND THEN STAYED CLOSE TO THE PREVIOUS FORECAST FOR
LATER ON MONDAY INTO MONDAY EVENING WITH A SLIGHT CHANCE IN THE FAR
NORTH. THIS LED TO BETTER ISC CONSISTENCY.
WITH LOW CLOUDS EXPECTED FOR MOST...IF NOT ALL OF THE NIGHT...MIN T
TONIGHT WILL BE CONSIDERABLY MILDER IN DEEPER SHELTERED VALLEY
LOCATIONS COMPARED TO RECENT NIGHTS. MIN T SHOULD REMAIN ABOVE
FREEZING IN ALL LOCATIONS. SOME THINNING OF THE CLOUDS IS ANTICIPATED
ON MON AFTERNOON AND TEMPS SHOULD GENERALLY REACH THE LOW TO MID 50S.
MIN T ON MON NIGHT IS A BIT MORE UNCERTAIN...AS SOME OF THE GUIDANCE
SUGGESTS THERE COULD BE WINDOW OF TIME WHERE CLOUDS COULD BE THIN
ENOUGH OR POSSIBLY BRIEFLY CLEAR AND ALLOW A RIDGE/VALLEY TEMP SPLIT
TO DEVELOP IN SOUTHEASTERN VALLEYS. NEVERTHELESS...MIN T ON MON
NIGHT SHOULD ALSO BE ABOVE NORMAL.
OTHERWISE...THE BULK OF THE PERIOD SHOULD BE DRY WITH SOUTHERLY TO
SOUTHWESTERLY LOW LEVEL FLOW INCREASING LATE IN THE PERIOD IN
ADVANCE OF A DEVELOPING MUCH MORE SIGNIFICANT SYSTEM THAT WILL IMPACT
THE REGION FROM MIDWEEK ON. THE 12Z AND 18Z NAM AS WELL AS THE 12Z
ECMWF SUGGEST A STRAY SHOWER MIGHT BE POSSIBLE OVER THE SOUTHWEST ON
TUE IN THE WARM SECTOR...BUT THE OTHER GUIDANCE WAS MORE SUPPORTIVE
OF JUST A CONSIDERABLE AMOUNT OF CLOUDS FROM TIME TO TIME. MUCH OF
THE RECENT MAX T GUIDANCE SUGGESTS TUE WILL BE RATHER MILD...ABOVE
NORMAL AND IF CLOUDS WERE TO THIN FOR A WHILE 60 DEGREES WOULD BE
REACHABLE IN MANY LOCATIONS. TUE TEMPS WERE RAISED A COUPLE OF DEGREES
ON AVERAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 PM EST SUN DEC 1 2013
THE UPPER AIR PATTERN OVER THE EASTERN THIRD OF THE CONUS WILL
FEATURE A LARGE STORM SYSTEM TAKING SHAPE OVER THE NORTHERN PLAINS
TO BEGIN THE PERIOD. BOTH THE GFS AND ECMWF MODELS HAVE VERY SIMILAR
SOLUTIONS REGARDING THE STRENGTH AND EVOLUTION OF THIS SYSTEM. THIS
SYSTEM IS PROGGED TO MOVE ACROSS THE UPPER GREAT LAKES REGION
WEDNESDAY NIGHT AND THURSDAY. AS IT DOES SO...A SURFACE COLD FRONT
WILL MOVE INTO THE AREA FROM THE NORTHWEST...AND EVENTUALLY STALL
ACROSS THE OHIO AND UPPER TENNESSEE VALLEY REGIONS FROM THURSDAY
NIGHT THROUGH SUNDAY. WEAK WAVES OF LOW PRESSURE MOVING ALONG THIS
BOUNDARY...COUPLED WITH A STRONG FEED OF MOISTURE OFF THE GULF OF
MEXICO...WILL COMBINE TO BRING A PROLONGED PERIOD OF PRECIPITATION
TO EASTERN KENTUCKY. THE FIRST COUPLE OF DAYS OF THE PERIOD WILL
FEATURE PERSISTENT SOUTHERLY FLOW OFF THE GULF...WITH HIGH
TEMPERATURES IN THE LOWER 60S ON WEDNESDAY...AND IN THE MID TO UPPER
50S ON THURSDAY. THE WARM MOIST AIR OFF THE GULF WILL BRING AN
INCREASE IN CLOUD COVER AS THE FRONT APPROACHES FROM THE WEST. THE
FIRST PRECIPITATION IS EXPECTED TO MOVE INTO THE NORTHWEST PART OF
THE AREA EARLY WEDNESDAY MORNING...AS WARM MOIST AIR BEGINS TO
INTERACT WITH THE LEADING EDGE OF THE APPROACHING COLD FRONT. AS THE
FRONT CONTINUES TO MOVE SLOWLY EASTWARD...PRECIPITATION WILL
INCREASE IN COVERAGE. THE FIRST GOOD CHANCE OF RAIN SHOULD ARRIVE
WEDNESDAY NIGHT...AS THE FRONT MOVES SOUTH OF THE OHIO RIVER. THE
BEST CHANCE FOR PRECIPITATION WILL OCCUR FROM EARLY THURSDAY MORNING
THROUGH EARLY SATURDAY MORNING...AS THE FRONT STALLS OVER THE
REGION. PRECIPITATION CHANCES SHOULD REMAIN IN THE FORECAST THROUGH
SATURDAY NIGHT...AS YET ANOTHER WEAK WAVE OF LOW PRESSURE MOVES
ALONG THE SLUGGISH FRONTAL BOUNDARY.
TEMPERATURES WILL REMAIN WARM ENOUGH TO KEEP PRECIPITATION IN THE
FORM OF RAIN FROM WEDNESDAY THROUGH FRIDAY AFTERNOON. WITH THE FRONT
STALLED OVER THE AREA...AND WITH A STEADY FEED OF MOISTURE OFF THE
GULF OF MEXICO INTERACTING WITH THE FRONT...THERE WILL THE POTENTIAL
FOR LOCALLY HEAVY RAINFALL. ONCE THE FRONT MOVES THROUGH THE
AREA...AND WINDS SHIFT TO THE NORTHWEST AND EVENTUALLY NORTH...SNOW
MAY BEGIN TO MIX WITH THE RAIN...BEGINNING IN THE FAR NORTHWESTERN
PORTION OF THE FORECAST AREA. THE LATEST TIME HEIGHT CROSS SECTIONS
AND SOUNDINGS SUPPORT A MIX OF RAIN AND SNOW FRIDAY NIGHT THROUGH
THE END OF THE DAY ON SATURDAY. IF THE LATEST MODEL DATA HOLDS
TRUE...THERE COULD BE ENOUGH COLD AIR IN PLACE ACROSS THE AREA FROM
EARLY SATURDAY NIGHT THROUGH EARLY SUNDAY AFTERNOON FOR
PRECIPITATION TO CHANGE OVER TO ALL SNOW. IF THIS TURNS OUT TO BE
THE CASE...WE COULD SEE SOME LIGHT SNOW ACCUMULATIONS SATURDAY NIGHT
AND SUNDAY ACROSS EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 105 AM EST MON DEC 2 2013
BORDERLINE...MVFR/VFR CEILINGS WILL LINGER THROUGH DAYBREAK...BEFORE
LIFTING SOLIDLY TO ALL VFR BY 10 AM. THE LOW CLOUDS WILL ATTEMPT TO
BREAK UP LATE IN THE DAY. OVERALL...LIGHT AND VARIABLE WINDS WILL BE
SEEN THROUGH THE TAF FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
358 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE EAST OF THE REGION TODAY. ANOTHER LOW
WILL TRACK EAST OF THE REGION TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK AREA OF LOW PRESSURE WILL CONTINUE TO MOVE EAST OF THE GULF
OF MAINE TODAY. CURRENT RADAR IMAGERY WAS SHOWING
PRECIPITATION...MAINLY IN THE FORM OF SNOW CONTINUING ACROSS MUCH OF
CENTRAL AND DOWNEAST MAINE...ALTHOUGH COULDNT RULE OUT SOME PATCHY
FREEZING RAIN ACROSS PORTIONS OF INTERIOR DOWN EAST THROUGH EARLY
THIS MORNING. LATEST HRRR SHOWS PRECIPITATION CONTINUING INTO MID
MORNING AND WITH TEMPERATURES NOT EXPECTED TO BUDGE TOO MUCH DECIDED
TO EXTEND THE WINTER WEATHER ADVISORY UNTIL 11 AM. THE HIGHEST SNOW
TOTALS WILL BE ACROSS CENTRAL PENOBSCOT AND WASHINGTON COUNTIES.
HOWEVER...WE LOWERED TOTAL SNOWFALL ACCUMULATIONS BASED ON CALLS TO
LOCAL/FED LAW ENFORCEMENT AGENCIES WHICH WERE INDICATING SNOWFALL
AMOUNTS BELOW OUR CURRENT FORECASTED AMOUNTS AS OF EARLY THIS
MORNING. THE PRECIPITATION ACROSS DOWNEAST AREAS SHOULD DIMINISH
LATER THIS MORNING AND WITH TEMPERATURES THIS AFTERNOON EXPECTED TO
RISE ABOVE FREEZING ANY LINGERING PRECIPITATION THIS AFTERNOON
DOWNEAST WILL BE IN THE FORM OF RAIN. ACROSS NORTHERN AREAS EXPECT
LIGHT SNOW TO CONTINUE INTO THIS AFTERNOON. ACROSS NORTHERN AREAS
EXPECT ACCUMULATIONS TODAY TO RANGE FROM 1 TO 3 INCHES. HIGHS
TODAY WILL RANGE FROM THE LOWER 30S NORTH AND MID TO UPPER 30S
DOWNEAST.
TONIGHT WILL BE CLOUDY WITH A CONTINUED CHANCE FOR SOME LIGHT SNOW
MAINLY ACROSS NORTHERN AREAS AND THE CHANCE FOR SOME LIGHT RAIN
SHOWERS ACROSS CENTRAL AND DOWNEAST. THERE COULD EVEN BE A LITTLE
LIGHT FREEZING RAIN OR DRIZZLE LATE TONIGHT ACROSS NORTHERN AREAS.
LITTLE TEMPERATURE CHANGE IS EXPECTED TONIGHT WITH LOWS IN THE UPPER
20S TO AROUND 30 NORTH AND LOW TO MID 30S DOWNEAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
LINGERING PRECIP PSBL ACROSS MAINLY NRN AREAS TUE AM AS INITIAL
WEAK LOW PRES AFFECTING THE REGION TODAY DISSIPATES WHILE
STRONGER LOW PRES WELL OFF THE MID ATLC STATES TUE AM BEGINS TO
TRACK NEWD TOWARD SRN NS... LATEST MODEL CONSENSUS CONTS TO
INDICATE THAT THIS SYSTEM WILL PASS WELL E OF THE AREA (ACROSS ERN
NS WED AM) W/ JUST A GLANCING BLOW ACROSS FAR ERN AND SERN AREAS
LATE TUE INTO TUE NGT. WILL BRING HIGHEST POPS (LIKELY) INTO OUR
SERN ZNS TUE AM INTO TUE EVE W/ CHC POPS CENTRAL AND N AND NE W/
SLGT CHC TO NIL POPS FAR W AND NW... LACK OF ANY REAL COLD AIR
ACROSS THE AREA ALSO SUGGESTS PRECIP ACROSS OUR SERN TO E CENTRAL
AREAS MAY BE RAIN OR A MX OF RAIN AND WET SNOW. IN ANY CASE...ATTM
DOES NOT APPEAR THAT THIS WILL BE A SIGNIFICANT WNTR SYSTEM FOR
OUR AREA... ANY PRECIP ASSOCIATED W/ THIS SYSTEM IS EXPECTED TO
EXIT THE AREA ERLY WED W/ A RIDGE OF HIGH PRES THEN FCST TO BUILD
ACROSS OUR FA WED. THIS WILL RESULT IN DRY COND W/ TEMPS A LITTLE
ABV SEASONAL NORMS W/ HIGHS RANGING FROM THE MID 30S N TO AROUND
40 S... &&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RIDGE OF HIGH PRES ACROSS THE FA WED EVE IS EXPECTED TO SHIFT E OF
THE REGION WED NGT AS DEEP LOW PRES OVR THE WRN GRT LKS LIFTS
NEWRD AND SWEEPS AN OCLD FRONT EWRD ACROSS THE NERN STATES AND OUR
AREA BY ERLY THU PER THE FASTER GFS AND BY LATE THU EVE PER THE
SLOWER ECMWF. THIS FRONTAL BNDRY IS THEN FCST TO BECOME NRLY
STATIONARY FROM THE SRN GULF OF MAINE SWWRD ACROSS THE SERN STATES
AND INTO THE WRN GULF OF MEX. GUIDANCE THEN SUGGESTS WAVES OF SFC
LOW PRES LIFTING NEWRD UP ALONG THIS FRONTAL BNDRY MAY BRUSH
MAINLY OUR SRN AREAS FRI INTO SAT W/ THE THREAT OF SOME PRECIP W/
DRIER AND COLDER AIR FINALLY OVERSPREADING THE ENTIRE REGION LATER
SAT THRU SUN... TEMPS WILL REMAIN ABV SEASONAL NORMS AT THE START
OF THE LONG TERM PD THEN GRADUAL TREND TO SEASONAL AND THEN TO BLO
SEASONAL NORMS BY SUN. POPULATED OUR LONG TERM GRIDS W/ THE
SUPER BLEND CONSENSUS AND MADE MINIMAL ADJUSTMENTS...&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
NEAR TERM: WIDESPREAD IFR/MVFR CONDITIONS ARE EXPECTED AT THE TERMINALS
TODAY IN LOW CIGS AND LGT SNOW NORTH AND LGT SNOW/RAIN KBGR/KBHB
TERMINALS. THESE FLIGHT CONDITIONS WILL PERSIST THROUGH TONIGHT.
SHORT TERM: MVFR TO PSBL IFR TUE INTO TUE NGT AS STRONG LOW PRES
TRACKS E OF THE REGION AND BRUSHES THE REGION W/ SOME PRECIP. VFR
CONDS EXPECTED WED INTO THU W/ ANOTHER ROUND OF MVFR TO IFR
EXPECTED LATER THU INTO FRI AS A COMPLEX FRONTAL SYSTEM CROSSES
THE REGION.
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
TONIGHT. VISIBILITY WILL BE REDUCED AT TIMES TO 1 TO 3 NM IN LIGHT
RAIN THROUGH TONIGHT.
SHORT TERM: SCA CONDS ARE EXPECTED TO DVLP LATER TUE AND CONT THRU
MUCH OF WED AS DEEP LOW PRES TRACKS E OF THE WATERS...
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
MEZ005-006-011-015>017-032.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA
SHORT TERM...KHW
LONG TERM...KHW
AVIATION...DUDA/KHW
MARINE...DUDA/KHW
AREA FORECAST DISCUSSION
NWS GRAY ME
248 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE TODAY.
LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE ON TUESDAY...
BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN SECTIONS.
BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW PRESSURE
SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT CROSSING
NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL THEN
SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
SFC TROF AND ASSOCIATED WEAK AREA OF LOW PRES OFF OF CAPE COD IS
CONTINUING TO PUMP PCPN INTO THE MIDCOAST. THAT LOW PRES HAS
ALLOWED WINDS TO BACK AROUND TO A MORE NLY DIRECTION...EFFECTIVELY
LOCKING THE COLDER AIR IN PLACE AT THE SFC. WHILE TEMPS ALONG THE
COAST ARE IN THE MID 30S...JUST INLAND THEY ARE AOB FREEZING.
ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH HI-RES MODEL GUIDANCE
LIKE THE HRRR AND RAP SUGGESTING H9 AND H8 TEMPS RISING ABOVE
FREEZING BY 12Z FOR MUCH OF THE COAST AND COASTAL PLAIN. THAT
MEANS THE CAPITAL REGION WHERE IT HAS BEEN SNFL MUCH OF THE NIGHT
WILL SEE A GRADUAL TRANSITION TOWARDS A MIX WITH RA AND FZRA.
GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN H8...SO GIVEN THAT
LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE REMOVED MUCH OF THE
PL FROM THE FORECAST. KGYX RADAR ALSO INDICATES THE 0.5 DEG
CORRELATION COEFFICIENT INFERRED MELTING LAYER GRADUALLY
INCREASING IN RANGE. THIS SUPPORTS THE NWP FORECAST WARMING
ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND KAUG SOONER
RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MEZ013-014-019>022.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
ANZ150-152-154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
437 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE OFF THE SOUTHEAST COAST WILL INTENSIFY...AS IT
MOVES NORTHEAST OFF THE MID ATLANTIC COAST TODAY INTO TUESDAY
MORNING. HIGH PRESSURE WILL BUILD OVER THE AREA AND THEN PUSH
OFFSHORE TUESDAY AFTERNOON THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST UPR AIR PATTERN WAS GENERALLY RATHER ZONAL ACRS THE UNITED
STATES...WITH A WEAK SHORTWV TROF MOVING INTO THE ERN THIRD OF THE
U.S. EARLY THIS MORNG. AT THE SFC...WEAK LO PRES WAS JUST OFF THE
NC/SC CST. SFC OBS/SAT PIX WAS SHOWING SKY COVER WAS RANGING FM
CLEAR TO CLOUDY ACRS THE REGION...DUE TO SC DECK (5000-7000 FT) OVR
EXTRM NW/NRN CNTIES AND PATCHY DENSE FOG OVR PORTIONS OF SE VA AND
CSTL NE NC. LATEST MODELS INDICATE THE SHRTWV TROF SWINGING THRU
THE REGION THIS AFTN INTO TNGT...RESULTING IN THE SFC LO
INTENSIFYING AS IT LIFTS NE AWAY FM THE NC AND DELMARVA CST. DUE
TO THE PROGRESSIVE NATURE OF THE SHRTWV TROF...THE BULK OF DEEP
MOISTURE AND LIFT SHOULD BE SITUATED OFF THE CST. AS A
RESULT...WILL MAINTAIN ONLY A 40% POP OVER TH FAR SE (FOR LIGHT
QPF AMOUNTS < .10") FOR LATER THIS MORNG INTO EARLY THIS EVENG.
OTHERWISE...MOST OF THE CWA WILL ONLY SEE SOME MID/HIGH LEVEL
CLOUDINESS TODAY INTO TNGT. HIGHS TODAY WILL GENERALLY BE IN THE
LWR TO MID 50S. LOWS TNGT WILL RANGE FM THE LWR 30S TO THE LWR
40S...WITH THE SKY AVERAGING PRTLY CLOUDY LATER TNGT INTO WED
MORNG.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
THE LOW WILL CONTINUE TO INTENSIFY DURING TUE...AS IT MOVES
FARTHER AWAY TO THE NE. THE RESULT WILL BE A DRY PERIOD TUE/WED AS
WEAK HIGH PRESSURE BUILDS ACRS THE AREA AS A TROUGH IS SLOW TO
APPROACH FROM THE WEST. TEMPERATURES WILL BE FAIRLY MILD WITH
HIGHS INTO THE MID/UPPER 50S TUE...LOWS IN THE 30S TO LOWER 40S
TUE NIGHT...AND INTO THE UPPER 50S TO LOWER/POSSIBLY MID 60S ON
WED AS SOUTHERLY FLOW INCREASES. THE CAVEAT HERE IS THAT MODEL
SOUNDINGS SHOW SOME LOW MOISTURE THAT MAY BE TOUGH TO BREAK ON
WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MAIN FEATURE FOR THE LONG TERM WILL BE AN ARCTIC FRONTAL
BOUNDARY THAT WILL MOVE THROUGH THE MID ATLANTIC STATES LATE IN THE
WEEK. THE MAIN ISSUE WILL BE PCPN RATHER THAN TEMPERATURES AS THE
FRONT SLOWS DOWN AND ABUNDANT MOISTURE STREAMS INTO THE AREA FROM
THE SOUTHWEST. DUE TO UPPER LEVEL RIDGING IN THE SOUTHEASTERN
STATES...THE AIR MASS WILL BE SHALLOW AND TEMPERATURES WILL BE SLOW
TO FALL. EVENTUAL READINGS ARE NOT EXPECTED TO BE AS COLD AS THOSE
WHICH WERE EXPERIENCED RECENTLY.
THE MODELS HAD THE FRONT STALLING TEMPORARILY OVER THE OHIO VALLEY
YESTERDAY BUT CURRENT MODEL RUNS HAVE THIS OCCURRING OVER THE MID
ATLANTIC AROUND THURSDAY NIGHT AND FRIDAY. THE EURO LINES UP WELL
WITH HPC AND FOLLOWED CLOSE TO IT WITH THE FORECAST. THIS SET UP
WOULD INDICATE AN EXTENSIVE AND SLOW MOVING PCPN PATTERN WITH AREAS
OF LIKELY POPS MAINLY BEHIND THE FRONT BEGINNING IN NORTHWEST
PORTIONS FRIDAY AND FRIDAY NIGHT AND INTO THE SOUTHEAST PART OF THE
AREA SATURDAY. CURRENT INDICATIONS ARE THAT PRECIPITATION DIMINISHES
FROM THE NORTH SATURDAY NIGHT AND NO SIGNIFICANT PTYPE ISSUES ARE
INDICATED THROUGH SUNDAY.
TEMPERATURES WILL START OUT MILD WITH LOWS WEDNESDAY AND THURSDAY
NIGHTS IN THE MID 40S TO MID 50S. HIGHS THURSDAY WILL BE MAINLY IN
THE 60S WITH UPR 50S PSBL ON THE MD EASTERN SHORE AND NEAR 70 ALONG
THE VA/NC BORDER. TEMPERATURES FRIDAY AND BEYOND WILL DEPEND ON THE
ULTIMATE PROGRESS OF THE FRONT. NON DIURNAL TEMPERATURE TRENDS ARE
PSBL BUT DID NOT GET FANCY THIS FAR OUT. CURRENT FORECASTS HAVE
HIGHS FROM THE MID 50S NORTH TO NEAR 70 IN OUR NORTH CAROLINA
COUNTIES FRIDAY. LOWS FRIDAY NIGHT ARE FORECAST TO RANGE FROM THE
UPR 30S NORTH TO LWR 50S NEAR THE ALBEMARLE SOUND. HIGHS SATURDAY
ARE EXPECTED TO BE FROM THE MID 40S NORTH TO MID 50S IN NORTH
CAROLINA AND IN THE 40S ACROSS THE AREA SUNDAY. LOWS SATURDAY NIGHT
LOOK TO BE IN THE 30S.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
LATEST OBS REFLECT LIFR FOG AT PHF/ORF/ECG IN ASSOCIATION WITH
DEVELOPING ADVECTION FOG OUT AHEAD OF DEVELOPING LOW PRESSURE.
LIGHT WINDS/AND NO AVAILABLE MIXING SUGGESTS THAT THIS FOG WILL
REMAIN IN PLACE THROUGH MID-MORNING.
THEREAFTER, NEXT ISSUE WL BE WITH RAIN CHANCES W/ DEVELOPING LOW
PRESSURE OFF THE N CAROLINA COAST. THIS SYSTEM WILL MOVE NE ACROSS
THE OUTER BANKS THIS MORNING BEFORE TRACKING OFF THE CAROLINA
COAST MONDAY AFTN. MODELS STILL DIFFER ON HOW FAR NW PCPN
ACTUALLY GETS BEFORE MOVING OFFSHORE. NEW HRRR DOES BRING RAIN
TOWARDS ECG BY 16Z. WL HOLD OFF WITH MENTIONING PREDOMINATE -SHRA
GROUP IN TAF FOR THIS ISSUANCE. OTW EXPECT MIDLVLS REMAIN TOO DRY
FARTHER NORTH. WL KEEP BKN HIGH / MID LEVEL CLOUD DECK IN PLACE
THROUGH TONIGHT AT ALL TERMINALS, CLEARING LATE MONDAY NIGHT.
OUTLOOK...MAINLY VFR SHOULD PREVAIL BEHIND THE SYSTEM TUE, AND WL
CONTINUE THROUGH THE MID WEEK PERIOD. AN EXTENDED PERIOD OF PCPN
WITH MVFR/IFR CONDS SHOULD BEGIN FRIDAY AHEAD OF A COLD FRONT
APPROACHING FROM THE NW.
&&
.MARINE...
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER THROUGH THE MIDDLE
OF THE COMING WEEK...RESULTING IN RELATIVELY BENIGN BOATING
CONDITIONS. THE ONLY EXCEPTION WILL BE A SLIGHT INCREASE IN
WINDS/WAVES MONDAY NIGHT/TUESDAY AS LOW PRESSURE LIFTS NORTHEAST
WELL OFF THE MID-ATLANTIC COAST. LIGHT W-SW WINDS BECOME NW LATE
TONIGHT BEFORE VEERING TO THE NE EARLY MONDAY. WINDS REMAIN NE
THROUGH THE DAY MONDAY BEFORE BACKING TO THE NW MONDAY NIGHT/TUESDAY
AS THE WEAK LOW PRESSURE SYSTEM PULLS AWAY FROM THE AREA. HIGH
PRESSURE WILL REBUILD LATE WED/THU...BEFORE SLIDING OFFSHORE LATER
THURSDAY-FRIDAY. SUB-SCA CONDITIONS ARE EXPECTED THROUGH THIS PERIOD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TMG
NEAR TERM...LKB/TMG
SHORT TERM...LKB/TMG
LONG TERM...LSA
AVIATION...MAM
MARINE...MAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
142 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE OFF THE SOUTHEAST COAST WILL MOVE NORTHEAST OFF
THE NORTH CAROLINA COAST OVERNIGHT INTO MONDAY MORNING. THE LOW
WILL INTENSIFY WELL OFF THE MID ATLANTIC COAST MONDAY AFTERNOON
INTO TUESDAY MORNING. HIGH PRESSURE WILL BUILD OVER THE AREA AND
AND THEN PUSH OFFSHORE TUESDAY AFTERNOON THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THE LATEST SURFACE ANALYSIS INDICATES A RATHER NEBULOUS PRESSURE
PATTERN ACROSS THE MID ATLANTIC. ALOFT...WATER VAPOR IMAGERY
INDICATES ZONAL FLOW ACROSS THE REGION...WITH AN EMBEDDED
SHORTWAVE TROUGH PASSING OFF THE SOUTHEAST COAST. FARTHER
UPSTREAM...A TROUGH IS DIGGING ACROSS THE SOUTHERN PLAINS. THE
LATEST GUIDANCE INDICATES THE PATTERN REMAINS ZONAL THROUGH MUCH
OF THE OVERNIGHT...BEFORE AMPLIFYING TOWARD MORNING AS THE CENTRAL
PLAINS TROUGH SWINGS ACROSS THE SOUTHEAST. THIS WILL ALLOW MUCH OF
THE LOCAL AREA TO REMAIN CLEAR OVERNIGHT...WITH THE EXCEPTION OF
THE FAR N...WHERE A MID-CLOUD DECK WILL LINGER FOR THE NEXT
SEVERAL HOURS...WHICH THEN LIFTS N AS THE MID-LEVEL FLOW PATTERN
BECOMES SW. SURFACE OBSERVATIONS ARE INDICATING SOME FOG OVER SE
PORTIONS THIS EVENING...AND IT APPEARS PATCHY FOG SHOULD PERSIST
THROUGH MUCH OF THE NIGHT. PATCHY FOG IS ALSO EXPECTED TO EXPAND N
ACROSS EASTERN VA AFTER MIDNIGHT. WITH SKIES REMAINING MOSTLY
CLEAR FOR MUCH OF THE NIGHT ACROSS MOST OF THE AREA...EXPECT MINS
TO DROP INTO THE UPPER 20S TO LOWER 30S OVER MUCH OF THE
CWA. THE NW PIEDMONT WILL LIKELY LINGER IN THE LOW 40S FOR THE
NEXT FEW HOURS BEFORE THE MID-CLOUD DECK LIFTS N. POPS WERE
REMOVED FOR THE FAR SE ZONES OVERNIGHT PER LATEST SATELLITE
IMAGERY AND NUMERICAL GUIDANCE.
ON MON...MODELS DEPICT THE UPPER TROUGH SWINGING THROUGH THE
REGION AROUND 18Z...BUT BULK OF DEEP MOISTURE AN LIFT SHOULD BE
SITUATED OFF THE COAST SO WILL ONLY CARRY ABOUT A 40% POP OVER TH
FAR SE (FOR LIGHT QPF AMOUNTS < .10"). MOST OF THE CWA WILL ONLY
SEE SOME MID/HIGH LEVEL CLOUDINESS THROUGH THE DAY. HIGHS GENLY IN
THE MID 50S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
THE LOW WILL THEN RAPIDLY INTENSIFY MON NIGHT/TUE...BUT WILL BE WELL
OFFSHORE WHILE DOING SO. THE RESULT WILL BE A DRY PERIOD MON
NIGHT/TUE/WED AS WEAK HIGH PRESSURE BUILDS ACRS THE AREA AS A
TROUGH IS SLOW TO APPROACH FROM THE WEST. TEMPERATURES WILL BE
FAIRLY MILD WITH HIGHS INTO THE MID/UPPER 50S TUE...LOWS IN THE
30S TO LOWER 40S TUE NIGHT...AND INTO THE UPPER 50S TO LOWER/POSSIBLY
MID 60S ON WED AS SOUTHERLY FLOW INCREASES. THE CAVEAT HERE IS
THAT MODEL SOUNDINGS SHOW SOME LOW MOISTURE THAT MAY BE TOUGH TO
BREAK ON WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE MAIN FEATURE FOR THE LONG TERM WILL BE AN ARCTIC FRONTAL
BOUNDARY THAT WILL MOVE THROUGH THE MID ATLANTIC STATES LATE IN THE
WEEK. THE MAIN ISSUE WILL BE PCPN RATHER THAN TEMPERATURES AS THE
FRONT SLOWS DOWN AND ABUNDANT MOISTURE STREAMS INTO THE AREA FROM
THE SOUTHWEST. DUE TO UPPER LEVEL RIDGING IN THE SOUTHEASTERN
STATES...THE AIR MASS WILL BE SHALLOW AND TEMPERATURES WILL BE SLOW
TO FALL. EVENTUAL READINGS ARE NOT EXPECTED TO BE AS COLD AS THOSE
WHICH WERE EXPERIENCED RECENTLY.
THE MODELS HAD THE FRONT STALLING TEMPORARILY OVER THE OHIO VALLEY
YESTERDAY BUT CURRENT MODEL RUNS HAVE THIS OCCURRING OVER THE MID
ATLANTIC AROUND THURSDAY NIGHT AND FRIDAY. THE EURO LINES UP WELL
WITH HPC AND FOLLOWED CLOSE TO IT WITH THE FORECAST. THIS SET UP
WOULD INDICATE AN EXTENSIVE AND SLOW MOVING PCPN PATTERN WITH AREAS
OF LIKELY POPS MAINLY BEHIND THE FRONT BEGINNING IN NORTHWEST
PORTIONS FRIDAY AND FRIDAY NIGHT AND INTO THE SOUTHEAST PART OF THE
AREA SATURDAY. CURRENT INDICATIONS ARE THAT PRECIPITATION DIMINISHES
FROM THE NORTH SATURDAY NIGHT AND NO SIGNIFICANT PTYPE ISSUES ARE
INDICATED THROUGH SUNDAY.
TEMPERATURES WILL START OUT MILD WITH LOWS WEDNESDAY AND THURSDAY
NIGHTS IN THE MID 40S TO MID 50S. HIGHS THURSDAY WILL BE MAINLY IN
THE 60S WITH UPR 50S PSBL ON THE MD EASTERN SHORE AND NEAR 70 ALONG
THE VA/NC BORDER. TEMPERATURES FRIDAY AND BEYOND WILL DEPEND ON THE
ULTIMATE PROGRESS OF THE FRONT. NON DIURNAL TEMPERATURE TRENDS ARE
PSBL BUT DID NOT GET FANCY THIS FAR OUT. CURRENT FORECASTS HAVE
HIGHS FROM THE MID 50S NORTH TO NEAR 70 IN OUR NORTH CAROLINA
COUNTIES FRIDAY. LOWS FRIDAY NIGHT ARE FORECAST TO RANGE FROM THE
UPR 30S NORTH TO LWR 50S NEAR THE ALBEMARLE SOUND. HIGHS SATURDAY
ARE EXPECTED TO BE FROM THE MID 40S NORTH TO MID 50S IN NORTH
CAROLINA AND IN THE 40S ACROSS THE AREA SUNDAY. LOWS SATURDAY NIGHT
LOOK TO BE IN THE 30S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LATEST OBS REFLECT LIFR FOG AT PHF/ORF/ECG IN ASSOCIATION WITH
DEVELOPING ADVECTION FOG OUT AHEAD OF DEVELOPING LOW PRESSURE.
LIGHT WINDS/AND NO AVAILABLE MIXING SUGGESTS THAT THIS FOG WILL
REMAIN IN PLACE THROUGH MID-MORNING.
THEREAFTER, NEXT ISSUE WL BE WITH RAIN CHANCES W/ DEVELOPING LOW
PRESSURE OFF THE N CAROLINA COAST. THIS SYSTEM WILL MOVE NE ACROSS
THE OUTER BANKS THIS MORNING BEFORE TRACKING OFF THE CAROLINA
COAST MONDAY AFTN. MODELS STILL DIFFER ON HOW FAR NW PCPN
ACTUALLY GETS BEFORE MOVING OFFSHORE. NEW HRRR DOES BRING RAIN
TOWARDS ECG BY 16Z. WL HOLD OFF WITH MENTIONING PREDOMINATE -SHRA
GROUP IN TAF FOR THIS ISSUANCE. OTW EXPECT MIDLVLS REMAIN TOO DRY
FARTHER NORTH. WL KEEP BKN HIGH / MID LEVEL CLOUD DECK IN PLACE
THROUGH TONIGHT AT ALL TERMINALS, CLEARING LATE MONDAY NIGHT.
OUTLOOK...MAINLY VFR SHOULD PREVAIL BEHIND THE SYSTEM TUE, AND WL
CONTINUE THROUGH THE MID WEEK PERIOD. AN EXTENDED PERIOD OF PCPN
WITH MVFR/IFR CONDS SHOULD BEGIN FRIDAY AHEAD OF A COLD FRONT
APPROACHING FROM THE NW.
&&
.MARINE...
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER THROUGH THE MIDDLE
OF THE COMING WEEK...RESULTING IN RELATIVELY BENIGN BOATING
CONDITIONS. THE ONLY EXCEPTION WILL BE A SLIGHT INCREASE IN
WINDS/WAVES MONDAY NIGHT/TUESDAY AS LOW PRESSURE LIFTS NORTHEAST
WELL OFF THE MID-ATLANTIC COAST. LIGHT W-SW WINDS BECOME NW LATE
TONIGHT BEFORE VEERING TO THE NE EARLY MONDAY. WINDS REMAIN NE
THROUGH THE DAY MONDAY BEFORE BACKING TO THE NW MONDAY NIGHT/TUESDAY
AS THE WEAK LOW PRESSURE SYSTEM PULLS AWAY FROM THE AREA. HIGH
PRESSURE WILL REBUILD LATE WED/THU...BEFORE SLIDING OFFSHORE LATER
THURSDAY-FRIDAY. SUB-SCA CONDITIONS ARE EXPECTED THROUGH THIS PERIOD.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LKB
NEAR TERM...AJZ/LKB
SHORT TERM...LKB/TMG
LONG TERM...LSA
AVIATION...MPR/MAM
MARINE...JDM
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1046 PM MST SUN DEC 1 2013
.AVIATION...
06Z TAF CYCLE
AREAS OF IFR AND LOCALLY LIFR CATEGORY STRATUS CIGS WILL LIKELY
CONTINUE TO BE AN AVIATION HAZARD ACROSS A GOOD PORTION OF NW NM
THROUGH THE NEXT 12 HRS...THAT IS THROUGH 18Z MON. THE VISIBILITY
IN FOG WILL LOWER AGAIN AFTER 10Z TONIGHT TO IFR LEVELS. ELSEWHERE
ONLY HIGH CIRRUS CLOUDS AND LIGHT TO MODERATE BREEZES ARE EXPECTED
WITH VFR CONDITIONS THROUGH THE NEXT 24 HOURS. 40
&&
.PREV DISCUSSION...325 PM MST SUN DEC 1 2013...
MAIN FORECAST CHALLENGE IN THE SHORT-TERM CONTINUES TO BE NAILING
DOWN WHEN THE PERSISTENT LOW CLOUD DECK OVER NW AND WEST CENTRAL NM
WILL SCOUR OUT OF THE AREA. THE VAST MAJORITY OF MODEL GUIDANCE DID
NOT SHOW THESE CLOUDS CONTINUING TO PLAGUE THE AREA TODAY BUT ALAS
THEY ARE STILL HOLDING STRONG. THE RUC13 WAS THE BEST TO HOLD ONTO
SATURATION IN THE NEAR SURFACE LAYER AND INDICATIONS ARE THAT IT
WILL CONTINUE TONIGHT AND EARLY MONDAY. WINDS ALOFT AND EVEN AT THE
SURFACE ARE INCREASING HOWEVER IT IS POSSIBLE THE THICK/PERSISTENT
LOW CLOUD DECK IS FEEDING BACK TO STRENGTHEN LOW LEVEL INVERSIONS
AND KEEP A VERY SHALLOW BOUNDARY LAYER DECOUPLED. OTHER INTERESTING
ITEM WILL BE WHETHER LOW CLOUDS CAN SEEP OVER THE WEST MESA AND END
UP IN THE MIDDLE RIO GRANDE VALLEY TONIGHT AS INCREASING NW FLOW
ADVECTS THE LAYER SE. BEST SHOT WILL BE WEST SIDE SO HAVE INCREASED
TO MOSTLY CLOUDY THERE OVERNIGHT.
CONSIDERABLE DIFFERENCES REMAIN WITH MODEL GUIDANCE ON THE DETAILS
OF THE NEXT SIGNIFICANT STORM SYSTEM BEYOND WEDNESDAY. FIRST WE
HAVE TO DEAL WITH SOME WIND. NW FLOW OVER THE REGION TODAY WILL
BACK TO WEST AND INCREASE TUESDAY. 700-500MB LAYER WINDS BTWN 50
AND 60KTS WILL COMBINE WITH A SURFACE LOW OVER THE PLAINS TO CREATE
STRONG WEST WINDS ALONG AND EAST OF THE CENTRAL MT CHAIN. IT IS
STILL A LITTLE EARLY BUT BETS ARE GOOD ON A HIGH WIND WATCH FROM
THE FOLLOWING SHIFT FOR TUESDAY. HEIGHT FALLS AND COLD ADVECTION
WILL BEGIN TUESDAY NIGHT ACROSS THE WEST AS THE JET AXIS DEPARTS
TO THE EAST. MEANWHILE...THE PLAINS PORTION OF AN ARCTIC AIRMASS
WILL BE SHIFTING SOUTH TOWARD THE NE PLAINS.
MODELS THEN STRUGGLE CONSIDERABLY DEALING WITH THE APPROACH OF A
SHEARING UPPER TROUGH AXIS OVER THE WESTERN CONUS WEDNESDAY AND
THURSDAY AND THE DEGREE OF MOISTURE ASSOCIATED WITH IT. A REALLY
GOOD CERTAINTY IS THAT IT IS GOING TO GET VERY COLD. AT THIS TIME
THE SUITE OF ENSEMBLE AND WPC GUIDANCE SHOWS THE PLAINS PORTION OF
THE ARCTIC AIRMASS SETTLING ONTO THE EAST SLOPES OF THE CENTRAL MT
CHAIN WHILE THE SECOND PORTION SHIFTS SOUTH THRU THE INTERMOUNTAIN
WEST. 700MB TEMPS BTWN -10 AND -14C WITH THIS AIRMASS ARE 1 TO 2
STANDARD DEVIATIONS BELOW CLIMO AND RESULTS IN HIGH TEMPS 15 TO 25
F BELOW NORMAL ALL AREAS. QPF AND SNOW IMPACTS WILL BE THE GREATEST
CHALLENGE WITH THIS SYSTEM. MODELS AGREE A BAND OF SNOW WILL SHIFT
SE OVER WESTERN NM WEDNESDAY THEN DISSIPATES WEDNESDAY NIGHT...WHILE
LOW CLOUDS AND LIGHT SNOW OR FLURRIES IMPACT THE EAST. THE GFS IS
THEN THE MOST BULLISH BREAKING OUT A LARGE AREA OF LIGHT/MODERATE
SNOW ALONG AND EAST OF THE CONT DVD THURSDAY THEN TAPERS OFF INTO
THE EAST FRIDAY. AT THIS TIME IMPACTS TO TRAVEL MAY BE HIGH WITH
EVEN LIGHT AMOUNTS OF PRECIP DUE TO THE SEVERITY OF THE COLD AND
BLOWING SNOW.
BELIEVE OR NOT MODELS ARE ADVERTISING AN EVEN COLDER SECOND ARCTIC
AIRMASS TO SHIFT SOUTH OVER THE WESTERN CONUS MONDAY AND TUESDAY OF
NEXT WEEK. 700MB TEMPS OVER NORTHERN NM ARE ADVERTISED BY THE ECMWF
TO FALL TO -24C WHICH IS EXCEPTIONALLY COLD. ANOTHER ROUND OF SNOW
IS ALSO ADVERTISED. GUYER
.FIRE WEATHER...
MAIN FIRE WEATHER ISSUES NEXT FEW DAYS WILL BE THE STRONG INVERSIONS
IN PLACE ACROSS ROUGHLY THE NW QUARTER TO THIRD OF THE STATE...
EMPHASIZING THE NW AND WEST CENTRAL VALLEYS TO THE WEST OF THE
CONTINENTAL DIVIDE. THIS WILL CONTINUE QUITE STRONG THROUGH TONIGHT
AND MON MORN...IMPROVING SOME MON AFTN AND RETURNING MORE WEAKLY MON
NIGHT INTO TUE MORN. AS A RESULT VENTILATION RATES TO REMAIN MAINLY
POOR IN THIS AREA THROUGH MON NIGHT. ACCOMPANYING THIS WILL BE VERY
LOW CLOUD DECK AND FREEZING FOG TONIGHT AND WELL INTO MON MORN.
OTHER SIGNIFICANT FIRE WX CONCERN WILL BE RISK OF MARGINALLY
CRITICAL FIRE WEATHER CONDITIONS FOR PERHAPS 2 OR 3 HOURS TUE AFTN
IN MAINLY SOUTHERN PORTION OF ZONE 108 IN EAST CENTRAL NM. MAIN
LIMITING ISSUE WILL BE THE MINIMUM RH.
OUTSIDE OF THE ABOVE MENTIONED AREAS...OVERNIGHT HUMIDITY RECOVERY
WILL STILL BE VERY GOOD TO EXCELLENT IN THE ESTANCIA AND UPPER RIO
GRANDE VALLEYS. HOWEVER...RECOVERIES WILL NOT BE AS HIGH IN THE
EASTERN PLAINS...MAINLY 45 TO 55 PERCENT. SCATTERED LOCALES ALONG
THE CENTRAL MOUNTAIN CHAIN AND CENTRAL HIGHLANDS WILL EXPERIENCE
BREEZY TO OCCASIONALLY WINDY CONDITIONS THROUGHOUT THE NIGHT AND
INTO MON. STILL...POOR VENTILATION/DISPERSION IS EXPECTED WEST OF
CENTRAL MTN CHAIN THROUGH MON NIGHT WITH TEMPERATURES RISING A
COUPLE TO SEVERAL DEGREES OVER TODAY. EAST OF CENTRAL MTN CHAIN
EXPECT FAIR TO LOCALLY VERY GOOD VENT RATES MON AFTN.
FLOW ALOFT BECOMES MORE WESTERLY MON NIGHT AND WEST SOUTHWESTERLY
BY TUE NIGHT AS LONGWAVE TROUGH ESTABLISHES TO THE WEST OF NM. AS
WINDS DRAMATICALLY INCREASE ALOFT THE 10000 FT LEVEL WINDS ARE
LIKELY TO REACH 45 TO 65 KT...PERHAPS EVEN A BIT HIGHER...ON MUCH OF
THE HIGHER TERRAIN. STRONG BUT RATHER SHALLOW BACK DOOR FRONT LIKELY
TO ENTER FAR NE NM LATE TUE OR EARLY WED WITH THE USUAL TIMING
DIFFERENCES BETWEEN THE MODELS. STRONG WINDS WILL REMAIN A CONCERN
FOR HIGH TERRAIN AREAS TUE. AHEAD OF THE FRONT THE EASTERN PLAINS
WOULD GET SOME DOWNSLOPING WARMING EFFECTS...AS TEMPS RUN 8 TO 15
DEGREES ABOVE AVERAGE WITH HUMIDITY OF 15 TO 20 PERCENT TUE AFTN.
BREEZY TO WINDY CONDITIONS WILL LIKELY PERSIST INTO WED...ESPECIALLY
THE HIGH TERRAIN ZONES...WHILE MUCH COLDER AIR SPILLS INTO THE STATE
FROM THE NE AND NW. SOME LIGHT TO LOCALLY MODERATE PRECIPITATION
WILL ALSO BE POSSIBLE ACROSS FCST AREA WED...SPREADING FARTHER EAST
THU AND FRI. PREFERRED AREAS WILL BE NW TWO THIRDS OF THE STATE. BY
THU THE ENTIRE FORECAST AREA TEMPS LIKELY TO FALL TO BETWEEN 10 AND
30 DEGREES BELOW AVERAGE. LITTLE IF ANY MODERATION FROM THE WELL
BELOW NORMAL TEMPS FRI. VENTILATION WILL SEE A MAJOR BOOST TUE AND
WED...BUT THEN STEADILY LOWER THU INTO FRI. 43
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
40
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1238 AM EST MON DEC 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SWING INTO THE GREAT
LAKES REGION TONIGHT AND SLOWLY LIFT INTO QUEBEC DURING THE DAY
MONDAY. HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND
REMAIN OVER THE AREA INTO WEDNESDAY BEFORE ANOTHER LOW AFFECTS
THE REGION MIDWEEK. HIGH PRESSURE RETURNS BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1228 AM EST MONDAY...NO SIGNIFICANT CHANGES WITH THIS
UPDATE. PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ISSUE A FREEZING FOG ADVISORY UNTIL 8 AM FOR THE
CHAMPLAIN VALLEY EASTWARD ACROSS THE REST OF VERMONT. WE`VE
RECEIVED SEVERAL REPORTS OF LIGHT GLAZING THIS EVENING IN THE
AREAS OF FREEZING FOG AND MIST THAT HAVE DEVELOPED ACROSS THE
NORTH COUNTRY. IT APPEARS THAT LIGHT NORTHERLY DRAINAGE FLOW
(EVIDENT IN LOWER RAP MODEL 1000-950MB THICKNESS FIELDS OVER THE
CHAMPLAIN VALLEY) IS HELPING TO MAINTAIN A PERSISTENT AREA OF
FREEZING FOG HERE IN THE CHAMPLAIN VALLEY. THE MAIN IMPACT FROM
FREEZING FOG AND MIST WILL BE FROM ICING...THOUGH VISIBILITIES AS
LOW AS AN EIGHTH OF A MILE ARE POSSIBLE IN AREAS OF FREEZING FOG.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 911 PM EST FOLLOWS...
EARLIER AREAS OF LIGHT SNOW HAVE GENERALLY COME TO AN END EXCEPT
FOR NORTHERN VERMONT AND INTO THE NORTHERN SAINT LAWRENCE VALLEY.
AREAS OF LIGHT SNOW LOOK TO LINGER THROUGH LATE EVENING/AROUND
MIDNIGHT IN THE NORTHEAST KINGDOM...AND CONTINUE PERIODICALLY
ACROSS THE NORTHERN SAINT LAWRENCE VALLEY AND `DACKS THROUGH
OVERNIGHT. HOWEVER...EXPECTING AREAS OF FREEZING DRIZZLE AND
PATCHY FREEZING FOG ACROSS A GOOD PORTION OF THE NORTH COUNTRY
THIS EVENING. POTENTIAL FOR FOG IS SHOWN NICELY ON BUFKIT
SOUNDINGS SHOWING A SATURATED NEAR-SFC LAYER...AND VERY LIGHT BL
FLOW IS ALSO ALLOWING FOR AREAS OF FREEZING MIST/FOG TO DEVELOP
(WITH VISIBILITIES RECENTLY AS LOW AS 1/4SM AT BTV AIRPORT). IN
ADDITION TO THE FOG...WV IMAGERY SHOWS DRY LAYER NOW ACROSS LAKE
ERIE MOVING EASTWARD. THE DRY LAYER ALOFT MAY PRODUCE PATCHY
FREEZING DRIZZLE THROUGH OVERNIGHT. A LIGHT WINTRY MESS TONIGHT
WITH OCCASIONAL PERIODS OF LIGHT SNOW...FREEZING FOG/MIST AND
AREAS OF FREEZING DRIZZLE. THESE CONDITIONS WILL LIKELY LEAD TO
SLIPPERY AREAS ON SIDEWALKS AND UNTREATED ROADWAYS AS WELL AS
SOME LIGHT GLAZING/RIMING ON TREES AND OTHER SURFACES OVERNIGHT.
SEE OUR SPECIAL WEATHER STATEMENT FOR MORE ON POTENTIALLY SLICK
ROADWAYS.
NO CHANGES TO CURRENT TEMPERATURES WITH READINGS GENERALLY
STAYING NEAR CURRENT VALUES THIS EVENING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...GOING INTO MONDAY...MDLS BRING
SECONDARY TROUGH INTO GREAT LKS REGION...ALLOWING FOR MORE
DIGGING/ AMPLIFICATION OF THE REMNANTS OF CURRENT TROUGH. THE
RESULT FOR THE CWA WILL BE PERSISTENT SW FLOW OVER THE NORTH
COUNTRY. PART OF THIS FLOW WILL OCCUR OVER LK ONTARIO...KEEPING
CHANCE FOR LIGHT PRECIP OVER N NY THRU THE DAY...TAPERING TO JUST
CLDY SKIES OVER EASTERN AND SOUTHERN VT. POSSIBLE FOR A COUPLE
TENTHS EXTRA -SW ACCUM THRU THE DAY...BUT WITH TEMPS ABV NORMAL
ON DECENT WAA...NOT GOING TO LAST. TROUGH LIFTS INTO SOUTHERN
QUEBEC MON NGT...TAPERING OFF SL CHANCE WINTRY PRECIP TO NE
KINGDOM BY TUESDAY MORNING..THEN SFC RIDGE BUILDS OVER AREA FOR
ANOTHER DECENT DAY WITH TEMPS ABV NORMAL. HIGHS IN THE MID/UPPER
30S BOTH DAYS...WITH OVERNGT LOWS ABV NORMAL BY SEVERAL DEGREES
IN THE 20S. WARMEST IN CVLY...COLDEST DACKS/NE VT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 413 PM EST SUNDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT
ON WEDNESDAY WITH SHOWING A RIDGE OF HIGH PRESSURE OVER THE
REGION. HOWEVER...MODELS SHOWING SOME TIMING DIFFERENCES
WEDNESDAY NIGHT WITH THE ARRIVAL OF PRECIPITATION AHEAD OF A
FRONTAL SYSTEM. HAVE OPTED TO GO WITH THE SLOWER TIMING OF THE
ECMWF AND BRING IN PRECIPITATION AFTER MIDNIGHT WEDNESDAY NIGHT.
MODELS IN AGREEMENT WITH HAVING PRECIPITATION OVER THE REGION ON
THURSDAY. HOWEVER...ECMWF MODEL KEEPS PRECIPITATION OVER THE
REGION THURSDAY NIGHT AS ECMWF SHOWING FRONTAL SYSTEM STALLING
JUST SOUTH OF THE REGION AS IT WILL BE PARALLEL TO THE UPPER
FLOW...AS WEAK WAVES OF LOW PRESSURE MOVE NORTHEAST ALONG THE
FRONT. ECMWF SHOWING PLENTY OF MOISTURE WILL STREAM NORTHEAST
FROM THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS INTO THE REGION.
HAVE LEANED TOWARD THE IDEA OF THE ECMWF IN STALLING THE FRONTAL
SYSTEM JUST SOUTH OF THE REGION WITH PRECIPITATION ACROSS THE
REGION FROM THURSDAY NIGHT THROUGH SATURDAY. MUCH COLDER AIR WILL
WORK INTO THE REGION SATURDAY AND SUNDAY. ALSO...A RIDGE OF HIGH
PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT AND SUNDAY
WITH FAIR AND DRY WEATHER EXPECTED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 06Z TUESDAY...AMBIENT LOW LEVEL MOISTURE AND LIGHT LOW
LEVEL FLOW WILL KEEP BKN/OVC MVFR/IFR CIGS ACROSS MUCH OF THE AREA
OVER THE NEXT 24 HOURS. SOME POCKETS OF VFR HERE AND THERE...BUT
THIS WILL BE THE EXCEPTION RATHER THAN THE RULE. PATCHY LIGHT
-FZDZ AND/OR -SN ALSO POSSIBLE...MAINLY AT KMSS THROUGH 12Z...THEN
POSSIBLE AT OTHER TERMINALS AFTER 18-21Z. AGAIN...WINDS LIGHT AND
GENERALLY 5 KTS OR LESS THROUGH THE FORECAST PERIOD.
OUTLOOK 06Z TUESDAY THROUGH FRIDAY...
06Z TUESDAY THROUGH 06Z THURSDAY...MAINLY VFR...WITH SOME LOCAL
POCKETS OF MVFR.
06Z THURSDAY THROUGH 00Z SATURDAY...AREAS OF MVFR/IFR IN RAIN AND SNOW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR
VTZ001>012-016>019.
NY...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR NYZ028-
035.
&&
$$
SYNOPSIS...JN
NEAR TERM...LOCONTO
SHORT TERM...JN
LONG TERM...NEILES
AVIATION...JMG/BANACOS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1230 AM EST MON DEC 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SWING INTO THE GREAT
LAKES REGION TONIGHT AND SLOWLY LIFT INTO QUEBEC DURING THE DAY
MONDAY. HIGH PRESSURE BUILDS OVER THE REGION MONDAY NIGHT AND
REMAIN OVER THE AREA INTO WEDNESDAY BEFORE ANOTHER LOW AFFECTS
THE REGION MIDWEEK. HIGH PRESSURE RETURNS BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1228 AM EST MONDAY...NO SIGNIFICANT CHANGES WITH THIS
UPDATE. PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ISSUE A FREEZING FOG ADVISORY UNTIL 8 AM FOR THE
CHAMPLAIN VALLEY EASTWARD ACROSS THE REST OF VERMONT. WE`VE
RECEIVED SEVERAL REPORTS OF LIGHT GLAZING THIS EVENING IN THE
AREAS OF FREEZING FOG AND MIST THAT HAVE DEVELOPED ACROSS THE
NORTH COUNTRY. IT APPEARS THAT LIGHT NORTHERLY DRAINAGE FLOW
(EVIDENT IN LOWER RAP MODEL 1000-950MB THICKNESS FIELDS OVER THE
CHAMPLAIN VALLEY) IS HELPING TO MAINTAIN A PERSISTENT AREA OF
FREEZING FOG HERE IN THE CHAMPLAIN VALLEY. THE MAIN IMPACT FROM
FREEZING FOG AND MIST WILL BE FROM ICING...THOUGH VISIBILITIES AS
LOW AS AN EIGHTH OF A MILE ARE POSSIBLE IN AREAS OF FREEZING FOG.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 911 PM EST FOLLOWS...
EARLIER AREAS OF LIGHT SNOW HAVE GENERALLY COME TO AN END EXCEPT
FOR NORTHERN VERMONT AND INTO THE NORTHERN SAINT LAWRENCE VALLEY.
AREAS OF LIGHT SNOW LOOK TO LINGER THROUGH LATE EVENING/AROUND
MIDNIGHT IN THE NORTHEAST KINGDOM...AND CONTINUE PERIODICALLY
ACROSS THE NORTHERN SAINT LAWRENCE VALLEY AND `DACKS THROUGH
OVERNIGHT. HOWEVER...EXPECTING AREAS OF FREEZING DRIZZLE AND
PATCHY FREEZING FOG ACROSS A GOOD PORTION OF THE NORTH COUNTRY
THIS EVENING. POTENTIAL FOR FOG IS SHOWN NICELY ON BUFKIT
SOUNDINGS SHOWING A SATURATED NEAR-SFC LAYER...AND VERY LIGHT BL
FLOW IS ALSO ALLOWING FOR AREAS OF FREEZING MIST/FOG TO DEVELOP
(WITH VISIBILITIES RECENTLY AS LOW AS 1/4SM AT BTV AIRPORT). IN
ADDITION TO THE FOG...WV IMAGERY SHOWS DRY LAYER NOW ACROSS LAKE
ERIE MOVING EASTWARD. THE DRY LAYER ALOFT MAY PRODUCE PATCHY
FREEZING DRIZZLE THROUGH OVERNIGHT. A LIGHT WINTRY MESS TONIGHT
WITH OCCASIONAL PERIODS OF LIGHT SNOW...FREEZING FOG/MIST AND
AREAS OF FREEZING DRIZZLE. THESE CONDITIONS WILL LIKELY LEAD TO
SLIPPERY AREAS ON SIDEWALKS AND UNTREATED ROADWAYS AS WELL AS
SOME LIGHT GLAZING/RIMING ON TREES AND OTHER SURFACES OVERNIGHT.
SEE OUR SPECIAL WEATHER STATEMENT FOR MORE ON POTENTIALLY SLICK
ROADWAYS.
NO CHANGES TO CURRENT TEMPERATURES WITH READINGS GENERALLY
STAYING NEAR CURRENT VALUES THIS EVENING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 315 PM EST SUNDAY...GOING INTO MONDAY...MDLS BRING
SECONDARY TROUGH INTO GREAT LKS REGION...ALLOWING FOR MORE
DIGGING/ AMPLIFICATION OF THE REMNANTS OF CURRENT TROUGH. THE
RESULT FOR THE CWA WILL BE PERSISTENT SW FLOW OVER THE NORTH
COUNTRY. PART OF THIS FLOW WILL OCCUR OVER LK ONTARIO...KEEPING
CHANCE FOR LIGHT PRECIP OVER N NY THRU THE DAY...TAPERING TO JUST
CLDY SKIES OVER EASTERN AND SOUTHERN VT. POSSIBLE FOR A COUPLE
TENTHS EXTRA -SW ACCUM THRU THE DAY...BUT WITH TEMPS ABV NORMAL
ON DECENT WAA...NOT GOING TO LAST. TROUGH LIFTS INTO SOUTHERN
QUEBEC MON NGT...TAPERING OFF SL CHANCE WINTRY PRECIP TO NE
KINGDOM BY TUESDAY MORNING..THEN SFC RIDGE BUILDS OVER AREA FOR
ANOTHER DECENT DAY WITH TEMPS ABV NORMAL. HIGHS IN THE MID/UPPER
30S BOTH DAYS...WITH OVERNGT LOWS ABV NORMAL BY SEVERAL DEGREES
IN THE 20S. WARMEST IN CVLY...COLDEST DACKS/NE VT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 413 PM EST SUNDAY...ECMWF AND GFS MODELS IN GOOD AGREEMENT
ON WEDNESDAY WITH SHOWING A RIDGE OF HIGH PRESSURE OVER THE
REGION. HOWEVER...MODELS SHOWING SOME TIMING DIFFERENCES
WEDNESDAY NIGHT WITH THE ARRIVAL OF PRECIPITATION AHEAD OF A
FRONTAL SYSTEM. HAVE OPTED TO GO WITH THE SLOWER TIMING OF THE
ECMWF AND BRING IN PRECIPITATION AFTER MIDNIGHT WEDNESDAY NIGHT.
MODELS IN AGREEMENT WITH HAVING PRECIPITATION OVER THE REGION ON
THURSDAY. HOWEVER...ECMWF MODEL KEEPS PRECIPITATION OVER THE
REGION THURSDAY NIGHT AS ECMWF SHOWING FRONTAL SYSTEM STALLING
JUST SOUTH OF THE REGION AS IT WILL BE PARALLEL TO THE UPPER
FLOW...AS WEAK WAVES OF LOW PRESSURE MOVE NORTHEAST ALONG THE
FRONT. ECMWF SHOWING PLENTY OF MOISTURE WILL STREAM NORTHEAST
FROM THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS INTO THE REGION.
HAVE LEANED TOWARD THE IDEA OF THE ECMWF IN STALLING THE FRONTAL
SYSTEM JUST SOUTH OF THE REGION WITH PRECIPITATION ACROSS THE
REGION FROM THURSDAY NIGHT THROUGH SATURDAY. MUCH COLDER AIR WILL
WORK INTO THE REGION SATURDAY AND SUNDAY. ALSO...A RIDGE OF HIGH
PRESSURE WILL BUILD INTO THE REGION SATURDAY NIGHT AND SUNDAY
WITH FAIR AND DRY WEATHER EXPECTED.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...AREAS OF LIGHT SNOW...MAINLY FROM THE
CHAMPLAIN VALLEY EWD...WILL CONTINUE THROUGH 03-04Z.
THEREAFTER...IT APPEARS SOME PATCHY FREEZING DRIZZLE WILL OCCUR
FROM SHALLOW LOW STRATUS DECK AT BTV/RUT/MPV WITH TEMPS AT TO
SLIGHTLY BELOW FREEZING. THIS MAY RESULT IN LIGHT ICING
CONDITIONS FOR AIRPORT OPERATIONS OVERNIGHT. ALSO ANTICIPATE IFR
CEILINGS THRU 13-14Z MONDAY AT MSS/MPV AND GENERALLY MVFR
ELSEWHERE. WINDS LIGHT AND VARIABLE OVERNIGHT...AND REMAINING 5
KTS OR LESS DURING THE DAYLIGHT HRS MONDAY. CEILINGS GENERALLY
MVFR (OVC015-025) DURING THE DAYLIGHT HRS MONDAY BUT WITH LESS
POTENTIAL FOR PRECIPITATION.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
00Z TUESDAY THROUGH 06Z THURSDAY...MAINLY VFR...WITH SOME LOCAL
POCKETS OF MVFR.
06Z THURSDAY THROUGH 00Z SATURDAY...AREAS OF MVFR/IFR IN RAIN AND SNOW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR
VTZ001>012-016>019.
NY...FREEZING FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR NYZ028-
035.
&&
$$
SYNOPSIS...JN
NEAR TERM...LOCONTO
SHORT TERM...JN
LONG TERM...NEILES
AVIATION...BANACOS/WGH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
100 AM EST MON DEC 2 2013
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP SOUTH OF THE AREA TONIGHT AND MOVE
NORTHEAST JUST OFF THE NORTH CAROLINA COAST MONDAY. THE LOW WILL
DEPART TO THE NORTHEAST TUESDAY AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE NORTHWEST THROUGH THE MIDDLE OF THE WEEK. THE HIGH
MOVES OFF THE COAST LATE IN THE WEEK THEN A COLD FRONT PUSHES
THROUGH THE AREA EARLY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1255 AM MONDAY...FORECAST WILL FOLLOW THE GFS MODEL WHICH IS
SUPPORTED BY THE HIGH RESOLUTION RAP MODEL AND DISCOUNT THE
WETTER/FURTHER INLAND PRECIPITATION FORECAST FROM THE NAM MODEL.
DEVELOPING COASTAL LOW PRESSURE WAS PRODUCING AN AREA OF SHOWERS
FROM NEAR THE CRYSTAL COAST TO THE OUTER BANKS SOUTH OF OREGON
INLET. THIS PRECIPITATION IS FORECAST TO PERSIST THROUGH EARLY
AFTERNOON MAINLY ALONG THE COAST SO HAVE RAISED POPS TO LIKELY
SOUTHEAST COAST AND TAPERED THEM TO LESS THAN 20% WELL
INLAND. THE GRADIENT IS VERY WEAK ACROSS THE AREA AND HAS LED TO
CALM WINDS INLAND. A CANOPY OF OVERCAST MID AND HIGH LEVEL CLOUDS
HAS PUSHED INTO SOUTHERN PORTIONS OF EASTERN NC WITH THIS CLOUD
DECK EXPECTED TO REMAIN ACROSS THE FAR SOUTH. WITH MOSTLY CLEAR
SKIES, GOOD RADIATIONAL COOLING IS OCCURRING ACROSS MUCH OF INLAND
EASTERN NC LATE TONIGHT AND THIS WILL GIVE RISE TO AREAS OF DENSE
FOG TONIGHT AND LOW TEMPERATURES FALLING INTO THE 30S. HAVE
ADJUSTED TEMPERATURES DOWNWARD INLAND AND ADDED MENTION OF FOG.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM TUESDAY/...
MOST PRECIP ASSOCD WITH THE AFOREMENTIONED SHORT WAVE AND COASTAL
SFC LOW SHUD FALL DURING THE MORNING HOURS THEN TAPERING OFF TO
MORE SPOTTY LIGHT PRECIP DURING THE AFTERNOON. AGAIN SIGNIFICANT
PRECIP MAY BE LIMITED TO MORE COASTAL AREAS WITH LIGHTER AND MORE
WIDESPREAD RAIN FARTHER INLAND. SKIES WILL REMAIN CLOUDY FOR MUCH
OF THE DAY IN THE INCREASING MOIST LOW LEVEL ONSHORE FLOW. EXPECT
TEMPS WILL REACH INTO THE LOW 60S ALONG THE COAST BUT ONLY MID 50S
OVER DEEP INLAND LOCATIONS.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 330 PM SUN...LINGERING PRECIP POSSIBLE MON EVE BUT THE LOW
EAST OF CAPE HATTERAS WILL BE QUICKLY LIFTING NE BRINGING CLEARING
SKIES ACROSS ERN NC AS SFC HIGH PRES AND SHORTWAVE RIDGING BUILDS
ACROSS THE AREA. N/NW FLOW WILL BRING SLIGHTLY BELOW NORMAL TEMPS
WITH LOWS IN THE 30S INLAND TO 40S COAST MON NIGHT WITH HIGHS IN
THE 50S TUE.
A LONGWAVE NRN STREAM UPPER TROUGH DIGS ACROSS THE WRN CONUS
THROUGH THE LATTER HALF OF THE WEEK WHILE SW/NE ORIENTED UPPER
TROUGH AMPLIFIES ACROSS THE SRN GOM AND OFF THE SOUTHEAST COAST
BRINGING SW FLOW ALOFT ACROSS THE ERN CONUS. ABUNDANT PACIFIC
MOISTURE WILL BE TRANSPORTED ACROSS THE SOUTHERN PLAINS IN THE MID
ATLANTIC WHILE A SLOW MOVING COLD FRONT PUSHES ACROSS THE MID WEST
AND MID ATLANTIC STATES. DEEPEST MOISTURE AND BEST UPPER LEVEL
DYNAMICS WILL REMAIN NORTH AND WEST OF THE REGION AND EXPECT
MAINLY DRY CONDITIONS BUT WILL SEE INCREASED CLOUD COVER ACROSS
ERN NC. A FEW MODELS ARE DEPICTING LIGHT QPF TUE NIGHT INTO WED
AS AN AREA OF WEAK AND SHALLOW ISENTROPIC LIFT MOVES ACROSS THE
AREA BUT THINK THEY AREA OVERDONE AND WILL CONTINUE WITH MINIMAL
POPS. THE REGION WILL SEE A WARMING TREND AS THE SFC HIGH SLIDES
OFFSHORE WED WITH INCREASING SWLY FLOW THROUGH THE END OF THE
WEEK. HIGH EXPECTED IN THE 60S WED...LOW 70S THU AND MID 70S ON
FRIDAY WITH MILD OVERNIGHT LOWS.
THE COLD FRONT WILL APPROACH THE REGION FRI NIGHT AND...AT THE
PRESENT TIME...MODELS ARE IN FAIR AGREEMENT WITH THE COLD FRONT
PUSHING SE ACROSS THE REGION FROM ABOUT 12Z-20Z SAT. IMPROVING
UPPER LEVEL DYNAMICS AS THE RIGHT ENTRANCE REGION OF THE UPPER JET
MOVES CLOSER TO THE REGION AND FRONTAL FORCING WILL BRING
INCREASED POPS. A NON-DIURNAL TEMP TREND IS EXPECTED FRI NIGHT AND
SAT SWLY BRINGING MILD TEMPS FRI NIGHT AND TEMPS PEAKING SAT
MORNING...THEN FALLING BEHIND THE FRONT. RAIN CHANCES AND COOL
TEMPS CONTINUE INTO SUN AS ISENTROPIC LIFT CONTINUES IN MOIST
SW FLOW ALOFT OVER SFC HIGH PRES RIDGING IN FROM THE NORTH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH MONDAY NIGHT/...
AS OF 1255 AM MONDAY...HIGH CONFIDENCE IN IFR/LIFR CONDITIONS
OCCURRING AT THE TAF SITES OVERNIGHT IN RADIATIONAL FOG.
PRECIPITATION IS EXPECTED TO OCCUR EAST OF THE TAF SITES WITH A
DEVELOPING COASTAL LOW. WEAK PRESSURE GRADIENT ACROSS EASTERN NC
WILL LEAD TO LIGHT WINDS AND THIS SUGGESTS THAT FOG WILL BE SLOW
TO BURN OFF MONDAY MORNING. ONCE FOG DISSIPATES LATE MONDAY
MORNING EXPECTING VFR CONDITIONS THROUGH MONDAY EVENING THEN COULD
SEE THE REDEVELOPMENT OF RADIATIONAL FOG LATE MONDAY NIGHT.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM SUN...A LOW PRESSURE SYSTEM EAST OF CAPE HATTERAS
WILL LIFT NE MON NIGHT INTO TUE. SUB-VFR CONDITIONS MAY LINGER AT
COASTAL TAF SITES EARLY MON EVENING BUT EXPECT IMPROVING
CONDITIONS AS THE EVENING WEARS ON. PRED VFR CONDITIONS EXPECTED
MID WEEK AS HIGH PRESSURE BUILDS OVER THE AREA. MOISTURE INCREASES
FOR THE LATTER HALF OF THE WEEK AS HIGH PRES SLIDES OFFSHORE AND
SW FLOW INCREASES BUT EXPECT PRED VFR CONDITIONS OUTSIDE OF PATCHY
EARLY MORNING FOG/STRATUS. SHOWER CHANCES GRADUALLY INCREASES
FRIDAY AS A COLD FRONT APPROACHES FROM THE NW.
&&
.MARINE...
SHORT TERM /THROUGH MONDAY/...
AS OF 1255 AM MONDAY...LIGHT VARIABLE WINDS ON THE COASTAL WATERS
AND SOUNDS LATE TONIGHT WILL BECOME MORE N/NE LATER EARLY MONDAY.
WEAK LOW PRESSURE DEVELOPING OFF OF THE COAST MONDAY WILL LEAD TO
STEADILY INCREASING NORTHERLY WINDS FROM 10 TO 15 KT EARLY TO 15-20
KT DURING MON AFTERNOON. SEAS MAINLY 2 TO 4 FT OVERNIGHT AND
MONDAY MAY APPROACH 5 FT OUTER WATERS BY LATE MONDAY AFTN.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM SUN...NW TO N WINDS AROUND 15-20 KT EXPECTED MON
NIGHT IN WAKE OF LOW WITH SEAS 3-5 FT NORTH AND 2-4 FT SOUTH.
WINDS DIMINISH TO BLO 15 KT AND SEAS SUBSIDE TO 2-4 FT THROUGHOUT
TUE AFTERNOON AND TUE NIGHT AS HIGH PRES BUILDS OVER THE AREA.
THE HIGH SLIDES OFFSHORE WED WITH LIGHT WINDS SHIFTING TO SW AND
GRADUALLY INCREASING THROUGH THE END OF THE WEEK AS PRES
GRADIENTS TIGHTEN IN RESPONSE TO A COLD FRONT SLOWLY APPROACHING
FROM THE NW. SCA CONDITIONS POSSIBLY DEVELOP THU NIGHT INTO FRI
WITH WINDS INCREASING TO 15-25 KT AND SEAS BUILD UP TO 4-6 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC/JME
SHORT TERM...BTC
LONG TERM...SK
AVIATION...JME/SK
MARINE...CTC/BTC/JME/SK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1253 AM EST MON DEC 2 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA TONIGHT...STALLING AND
DISSIPATING LATE ON MONDAY. INCREASING SOUTHERLY FLOW WILL ALLOW
FOR WARMING TEMPERATURES AND GRADUAL INCREASES FOR PRECIPITATION
CHANCES...BEFORE A STRONGER COLD FRONT MOVES THROUGH THE AREA
LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MID CLOUDS RACING E FROM IL WILL OVERSPREAD THE REGION IN THE NEXT
FEW HOURS. THEY WILL TOP THE LINGERING SC THAT HAS BEEN AFFECTING
PORTIONS OF THE REGION FOR MUCH OF THE DAY.
THE ADDITIONAL CLOUD COVER SHOULD KEEP THE TEMPERATURES IN THE N
FROM FALLING TOO MUCH MORE. EXPECT THE LOWS IN THE NORTH TO DROP
INTO THE LOWER 30S. MEANWHILE ACROSS THE SRN COUNTIES THE
TEMPERATURES SHOULD ONLY DROP INTO THE UPPER 30S..
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
ALTHOUGH NO SIGNIFICANT IMPACTS ARE EXPECTED DURING THE SHORT TERM
OF THE FORECAST...AND POPS ARE EXPECTED TO REMAIN IN THE CHANCE
RANGE OR LOWER...THE SPECIFIC DETAILS FOR PRECIPITATION AND CLOUDS
(IN TERMS OF AMOUNTS AND TIMING) ARE A LITTLE LOWER IN CONFIDENCE
THAN NORMAL.
THE BOUNDARY FORECAST TO MOVE INTO THE FORECAST AREA TONIGHT AND
INTO EARLY MONDAY MORNING WILL LOSE ITS DEFINITION...LEAVING THE
CWA IN A PATTERN OF VERY WEAK S-TO-SE FLOW. FLOW IN THE MID LEVELS
WILL BE QUASI-ZONAL...BUT WITH A SOMEWHAT-BROAD SHORTWAVE MOVING
INTO THE OHIO VALLEY ON MONDAY. THE OVERALL RESPONSE TO THIS
FEATURE IS NOT ESPECIALLY STRONG ON ALL MODELS BUT THE GFS (EVEN
ON BOTH THE 06Z AND 12Z RUNS). ALTHOUGH LOW LEVEL MOISTURE APPEARS
PREVALENT ON MOST MODELS...THE GFS IS BY FAR THE MOST ENHANCED
WITH DEEPER MOISTURE AND QPF RESPONSE. POPS FOR MONDAY AND INTO
MONDAY NIGHT HAVE BEEN SCALED BACK TO SLIGHT CHANCE...PUSHING
NORTH OF THE CWA BEFORE TUESDAY MORNING BEGINS.
AFTER WHAT LOOKS TO BE A DRY PERIOD ON TUESDAY...WARM FRONTAL
PROCESSES WILL BEGIN...AS LOW PRESSURE DEVELOPS OVER THE
MISSISSIPPI VALLEY. THIS WILL INCREASE THE SOUTHERLY FLOW AND
BEGIN A PATTERN OF WARM ADVECTION THAT WILL CONTINUE INTO THE LONG
TERM OF THE FORECAST. INCREASING CONVERGENCE AND MOISTURE
TRANSPORT (ESPECIALLY ALOFT ON TUESDAY NIGHT) WILL RESULT IN
PRECIPITATION CHANCES GRADUALLY INCREASING FROM WEST TO EAST
ACROSS THE CWA...THOUGH MOTION OF SHOWERS WILL BE IN MORE OF A
SSW-TO-NNE DIRECTION. THIS IS ONE PART OF THE FORECAST THAT DOES
COME WITH A BIT OF INCREASING CONFIDENCE. BECAUSE OF
THIS...TEMPERATURE ADJUSTMENTS WERE ALSO REQUIRED FOR BOTH TUESDAY
(SLIGHTLY UPWARD) AND TUESDAY NIGHT (SIGNIFICANTLY UPWARD).
PLENTIFUL CLOUDS AND MOISTURE...COMBINED REASONABLY STRONG FLOW
FOR AN OVERNIGHT PERIOD...SUPPORTS THIS DECISION. THE CURRENT
GRIDS WERE INCREASED BY 5-7 DEGREES...BUT IF SOME OF THE RAW
MODELS ARE TO BE BELIEVED...THIS MAY NOT EVEN BE ENOUGH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN WILL TRANSITION TO A HIGHLY AMPLIFIED REGIME
THROUGH THE EXTENDED PERIOD. THERE CONTINUES TO BE ISSUES WITH
TIMING AND RUN TO RUN CONTINUITY WITH MAJOR SYNOPTIC SYSTEMS TO
AFFECT OUR REGION. LOOKING AT THE VARIOUS OPERATIONAL MODELS...HAVE
DECIDED TO GO WITH A 25 PERCENT 12Z ECMWF AND A 75 PERCENT 12Z GFS.
WE ARE GETTING TO THE POINT IN THE FORECAST WHERE DIURNAL RISE AND
FALL WILL NOT CUT IT WITH FRONTS MOVING THROUGH AND WAVES OF LOW
PRESSURE RIDING ALONG THE FRONTAL BOUNDARY.
ON WEDNESDAY...LONG WAVE TROUGH WILL BE CARVING ITSELF OUT OVER THE
WESTERN U.S. FIRST WEATHER ISSUE IS THE AMOUNT OF ENERGY THAT WILL
EJECT FROM THIS FEATURE ACROSS THE NORTHERN PLAINS AND INTO CENTRAL
CANADA. GFS IS STRONGER AND FASTER WITH THIS ENERGY WHILE THE ECMWF
IS SLOWER...AND THIS HAS BEEN THE CASE OVER THE LAST SVRL RUNS. THIS
WILL HAVE FRONTAL IMPLICATIONS THROUGH OUR REGION WEDNESDAY INTO
THURSDAY. WITH AFOREMENTIONED BLEND...IT ALLOWS FOR A COLD FRONT TO
MOVE THROUGH THE REGION WEDNESDAY NIGHT...BUT NOT AS FAST AS THE GFS
INDICATES. IN ADVANCE OF THE FRONT...WAA SHOWERS ARE FORECAST TO
BREAK OUT AND LIKELY POPS SEEM REASONABLE AT THIS TIME.
FOR THE PERIOD THURSDAY INTO FRIDAY...THIS TIME FRAME IS SHAPING UP
TO BE INCLEMENT AS COLD FRONT SAGS TO OUR SOUTHEAST AND BECOMES
QUASI STATIONARY AS WAVES OF LOW PRESSURE RIDE ALONG IT. THESE WAVES
WILL BRING A SHOT OF FRONTOGENETIC FORCING TO OUR REGION LATE
THURSDAY INTO THURSDAY NIGHT WITH ANOTHER ROUND OF MID TO UPR LVL
FORCING FRIDAY INTO FRIDAY NIGHT. DURING THIS TIME...COLD AIR WILL
SLOWLY SEEP INTO THE REGION FROM THE NORTHWEST. AS SUCH...THERE WILL
BE SOME WINTRY PCPN TYPE ISSUES AS LOW LEVELS COOL BUT AIR ABOVE
WILL BE SLOWER TO COOL. STILL TO EARLY TO GET SPECIFIC GIVEN THE
THERMAL FIELD OSCILLATIONS AT THIS POINT SO JUST HAVE RAIN/SNOW
MENTIONED. LIKELY POPS STILL SEEM REASONABLE FOR MOST OF THE REGION
WITH EACH WAVE RIPPLING BY.
BY FRIDAY NIGHT INTO SATURDAY...COLD ARCTIC HIGH PRESSURE WILL WEDGE
SOUTHEAST INTO OUR AREA. THIS SHOULD PUSH THE PCPN OUT OF THE AREA
BY SATURDAY. THE HIGH WILL SET UP ACROSS THE REGION SATURDAY NIGHT
AND WILL MOVE EAST BY SUNDAY. THIS SHOULD GIVE THE REGION A DRY BUT
COLD PERIOD OF WEATHER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AC DECK CONTINUES TO WORK INTO THE REGION AND OVERRUN A LINGERING
SC DECK. LATEST RUNS OF THE RAP AND NAM ARE BOTH INDICATING THAT
ANY SC THAT LINGER ACROSS THE REGION WILL REMAIN VFR.
MEANWHILE...SOME MVFR FOG WILL BE POSSIBLE ACROSS THE NRN TAFS
THRU SUNRISE.
SC AND AC DECKS WILL LINGER ACROSS THE TAFS ON MONDAY...BUT SHOULD
BE VFR. THEN AS A S/W APPROACHES THE REGION AFT 00Z TUESDAY...THE
STALLED FNT ACROSS THE REGION WILL BEGIN TO LIFT N AS A WARM
FRONT. COULD SEE SOME MVFR CIGS AND A FEW SHRA AS THIS FEATURE
LIFTS N.
OUTLOOK...SOME MVFR CEILINGS POSSIBLE THROUGH TUESDAY MORNING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE AGAIN WEDNESDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...SITES
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
312 AM CST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST MON DEC 2 2013
ALL MODELS SHOW TWO WAVES MOVING ACROSS THE DAKOTAS AND MINNESOTA
THE NEXT 24 H. THE FIRST WAVE IS ALREADY INTO CENTRAL SD PER WATER
VAPOR IMAGERY AND WILL LIKELY BE INTO SW MN AND NW IA BY 00Z. THERE
ARE FEW ECHOES ASSOCIATED WITH THIS SYSTEM AND THOSE ARE PRIMARILY
ACROSS FAR NORTHERN SOUTH DAKOTA. WITH VERY DRY AIR BELOW 10000 FT
AND BEST FORCING FOR ASCENT IN NRN SD...HAVE REMOVED ANY CHC OF
PRECIPITATION WITH THIS WAVE. CLOSE ON ITS HEELS THOUGH IS A SECOND
WAVE. THE NAM IS FASTER AND FARTHER NORTH THAN EITHER THE RAP OR GFS
WITH THIS WAVE. CURRENT TRAJECTORY FROM WATER VAPOR FAVORS THE GFS
AND RAP AND FOLLOWED FOR LATER TONIGHT. THIS PUTS SAME STRONG
PRESSURE ADVECTION ON THE 1.5 PV SFC OVER THE CWA BY MIDNIGHT AND
CONTINUING THROUGH SUNRISE. AGAIN...MOISTURE IS A BIG ISSUE AS ALL
MODELS SHOW A 5000 TO 10000 FT DRY LAYER ABOVE THE SURFACE. FOR MUCH
OF SE SD AND NW IA...THIS DRY AIR EXPECTED TO EVAPORATE ANY
PRECIPITATION THAT DOES REACH THE SURFACE. THE ONLY PLACE THE DRY
AIR MAY BE OVERCOME IS IN SW MN WHERE IT MAY INTERACT WITH THE 850
MB BOUNDARY AND ENHANCE THE LIFT AND SATURATION. WHILE THE DRY AIR
LIKELY WILL LIMIT PCPN EVEN THERE...DID KEEP A SLIGHT CHANCE OF
PRECIPITATION FROM LATE EVENING THROUGH 12Z IN SW MN. TEMPERATURES
ALOFT ARE WELL ABOVE FREEZING...EVEN THE WET BULB TEMPERATURE WILL
BE ABOVE ZERO AND SHOULD MELT ANY PRECIPITATION ALOFT. TEMPERATURES
AT THE SURFACE THIS EVENING EXPECTED TO DROP TO AROUND 30 AND THEN
STEADY OUT AS CLOUDS AND SOUTH WINDS INCREASE. WHILE THERE IS A
POSSIBILITY TEMPERATURES COULD RISE ABOVE FREEZING AS ANY
PRECIPITATION MOVES IN...BELIEVE IT IS MOST LIKELY TO STAY JUST
BELOW FREEZING MOST OF THE NIGHT. SO ANY PRECIPITATION WILL LIKELY
BE A MIX OF FREEZING RAIN AND SLEET. AMOUNTS WILL BE LIGHT...A TRACE
TO A COUPLE HUNDREDTHS...BUT ENOUGH THAT IT COULD SLICK UP ROADS
SHOULD IT FALL.
OTHERWISE...THE PRECIPITATION WILL MOVE OFF BY MONDAY MORNING. THERE
WILL BE A LOT OF CLOUDS AROUND...ESPECIALLY EAST OF THE JAMES RIVER.
IT WILL ALSO BE VERY WARM ALOFT WITH +10C AT 925 MB IN SOUTH CENTRAL
SD WHERE THERE WILL ALSO BE SOME SUN. THEREFORE...EXPECT HIGHS TO
WARM INTO THE LOWER TO MID 50S IN SOUTH CENTRAL SD...WITH UPPER 40S
POSSIBLE OVER MUCH OF SE SD AND INTO NORTHEAST NEBRASKA AND
NORTHWEST IOWA. THE COLDEST TEMPS WILL BE IN SW MN WHERE CLOUDS WILL
BE AROUND MOST OF THE DAY AND WINDS WILL REMAIN S OR SE. BUT EVEN
THERE HIGHS WILL REACH THE LOWER 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 311 AM CST MON DEC 2 2013
MODELS CONTINUE TO TREND FASTER WITH THE SURGE OF COLD AIR AND
TUESDAY NOW UNDER THE GUN FOR POTENTIALLY COLDER TEMPERATURES.
HOWEVER WHAT IS INTERESTING IS AN OCCASIONAL BIAS OF THE GFS WHICH
COLLAPSES THE LEADING TROUGH AND ARCTIC SURGE WHILE THE ECMWF AND
ESPECIALLY THE NAM KEEP THESE TWO BOUNDARIES SEPARATE. IN THE PAST
IT SEEMS WHEN THE NAM AND ECMWF HINT AT THESE TWO BOUNDARIES THEY
GENERALLY VERIFY SO WILL LEAN A LITTLE MORE TOWARDS THE WINDS OF THE
NAM AND ECMWF. BUT UNFORTUNATELY THE NAM AND ECMWF ARE DIFFERENT
ENOUGH THAT BLENDING THESE TWO MODELS IS ALSO DIFFICULT AS THE ECMWF
HAS BEEN THE SLOWEST MODEL EACH RUN AND IS QUITE A BIT SLOWER ON
SHIFTING THE INVERTED TROUGH EAST. FOR NOW WILL GO WITH MAINLY
NORTHWEST WINDS GRADUALLY DEVELOP FROM WEST TO EAST THROUGH THE DAY.
THE MAIN UPPER LEVEL SUPPORT LOOKS TO BE TO THE NORTH OF THE AREA
HOWEVER THE CWA IS WITHIN A TRAILING LOBE OF INSTABILITY ALOFT BUT
FOR NOW THAT AREA OF INSTABILITY IS IN A FAIRLY DRY LAYER SO THE
THREAT FOR PRECIPITATION LOOKS TO BE SOMEWHAT SMALL. STILL LOOKING
LIKE A MAINLY RAIN OR SNOW THREAT FOR THE DAY TUESDAY AS THE INITIAL
PUSH OF COOLER AIR SURGES THROUGH BUT MIXING SHOULD SUPPORT
TEMPERATURES ABOVE FREEZING AT THE SURFACE SO NO REAL THREAT FOR
FREEZING PRECIPITATION. WILL HAVE A SMALL THREAT FOR LIGHT FREEZING
RAIN IN THE FAR NORTHERN CWA BEFORE 15Z BUT AFTER THAT A RAIN OR
SNOW THREAT. THIS CHANCE FOR RAIN OR SNOW SHOULD CHANGE TO ALL SNOW
BY TUESDAY EVENING WITH GRADUALLY DECREASING CHANCES INTO WEDNESDAY.
MODELS DIFFERENT ENOUGH POPS WILL REMAIN MID TO LOW RANGE AND
AMOUNTS WILL REMAIN LIGHT. STILL FEEL THAT THERE WILL BE A THREAT
FOR ABOUT 1 TO 3 INCHES OF SNOW BUT AT THIS TIME JUST NO WAY TO
REALLY SAY WHERE...BUT WILL KEEP THE SLIGHTLY HIGHER AMOUNTS IN THE
NORTHERN CWA.
THE COLDER DRIER AIR REALLY SETTLES IN BY WEDNESDAY EVENING AND NOT
EXPECTING ANY THREAT FOR SNOWFALL WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. WHILE A FEW FLURRIES MAY BE POSSIBLE THE THREAT IS PRETTY
LOW.
DID DECREASE HIGHS A BIT AGAIN ON WEDNESDAY WITH THE SURGING COLD
AIR...LOOKING AT MAINLY TEENS WITH A FEW LOWER 20S IN NORTHWEST
IOWA. WITH SOME WIND AND CLOUD COVER EXPECTED ON WEDNESDAY NIGHT DID
NOT GO TOO COLD BUT STILL PRETTY MUCH SINGLE DIGITS EVERYWHERE WITH
DIURNAL CHANGES ON THURSDAY ONLY ABOUT 5 DEGREES SO HIGHS IN THE
SINGLE DIGITS TO 10 TO 15 DEGREES. WITH THE NORTHWEST WINDS ON
THURSDAY A WIND CHILL ADVISORY NOT IMPOSSIBLE OVER THE NORTHERN TIER
OR TWO OF COUNTIES LATE WEDNESDAY NIGHT INTO THURSDAY MORNING.
IN THE OUTER PERIODS...FRIDAY THROUGH SUNDAY...COLD AIR REMAINS
FAIRLY ENTRENCHED OVER THE AREA AS AN UPPER LEVEL TROUGH CONTINUES
TO DIG TO THE WEST OF THE AREA. A WAVE DOES TRY TO DEVELOP AND MOVE
ACROSS THE AREA ON SUNDAY WHICH WILL BRING A NORTHWARD KINK OF LESS
COLD AIR INTO THE REGION. IF THIS PATTERN EVOLVES AS THE MODELS ARE
HINTING AT WE WOULD SEE A DECENT CHANCE FOR SNOW AS A FAIRLY STRONG
BAROCLINIC ZONE WOULD DEVELOP AND THERE WOULD BE THE POTENTIAL FOR A
FAIRLY DEEP DENDRITIC ZONE. ALL OF THIS IS PRETTY FAR OUT BUT SOME
OF THE IMPORTANT INGREDIENTS ARE BEING HINTED AT SO WILL BE
SOMETHING TO WATCH FOR. OTHERWISE BELOW NORMAL TEMPERATURES THROUGH
THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 941 PM CST SUN DEC 1 2013
WEAKER LEAD WAVE MOVING THROUGH MINNESOTA AND IOWA...WITH
SECONDARY SYSTEM RACING INTO NORTHWEST SOUTH DAKOTA. LIFT FORCING
WITH SECONDARY WAVE LOOKS TO REMAIN MAINLY NORTH AND EAST OF THE
TAF SITES...WITH POTENTIAL FOR PERHAPS A LITTLE LIGHT FREEZING
RAIN OR RAIN NEAR THE KHON SITE AROUND 07Z-11Z WINDOW.
HOWEVER...NOT WORTH A MENTION WITH VERY LOW PROBABILITY EVENT AT
THIS TIME. EVEN WITH A BIT BETTER THREAT OF PRECIPITATION TOWARD
SW MN...CONDITIONS ARE LIKELY TO REMAIN VFR EVEN IN ANY
PRECIPITATION...GREATER THAN 6 SM AND CEILINGS ABOVE 3000 FT AGL.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...08
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SPOKANE WA
923 PM PST Sun Dec 1 2013
.SYNOPSIS...
Big changes will arrive to the Inland Northwest this week as a
strong low pressure system pushes into the region. Mild conditions
will continue tonight with very breezy winds and heavy mountain
snow. An arctic cold front will sweep through the region Monday
and temperatures will plunge to some of the coldest readings the
region has experienced over the past couple years. This cold will
likely persist through the week.
&&
.DISCUSSION...
Forecast remains cluttered with strong upper level jet associated
with the wet frontal system slowly sagging south through the
forecast area tonight. HRRR runs suggest some precipitation of a
showery form will fill in a bit in the cold post frontal
conditionally unstable airmass behind the wetter weather along and
ahead of the front exiting to the south/southeast so have resisted
the urge to cut pops. Additionally some locations remain decoupled
at the surface and have not had the stronger upper level winds mix
down yet but momentum mixing from showery precip would allow it to
occur so have resisted urge to decrease wind in those locations
for similar reasons. Forecast temp trend with the cold air coming
down from the north continues to suggest the scenario depicted in
the grids that temperatures will fall through much of the day
Monday which means the high temps expected for Monday may very
well occur not to far from sunrise. /Pelatti
&&
.AVIATION...
06Z TAFS...Wet frontal zone and its associated strong upper level
jet sagging south over the aviation area will allow for a general
transition to less precipitation and more wind overnight and into
tomorrow. Some locations have remained decoupled from the stronger
upper level Southwest to Northwest winds aloft and as such have
had to include a mention of some low level wind shear. Otherwise
the precipitation and its associated low ceilings and visibility
restrictions will keep MVFR and local IFR ceilings in some shape
or form at times and snow levels will lower considerably as we get
colder through the day Monday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 37 18 24 12 17 / 50 30 20 10 0 0
Coeur d`Alene 37 37 16 23 10 16 / 100 50 30 10 10 0
Pullman 38 39 20 25 11 17 / 90 50 20 10 10 10
Lewiston 43 45 24 29 14 21 / 80 50 30 20 10 10
Colville 34 35 16 24 8 18 / 50 40 20 0 0 0
Sandpoint 35 36 17 21 8 14 / 100 80 30 10 10 0
Kellogg 37 38 12 17 6 12 / 100 90 60 20 10 10
Moses Lake 37 40 19 28 16 23 / 10 20 10 0 0 0
Wenatchee 33 38 20 27 14 22 / 10 20 20 0 0 0
Omak 31 34 11 23 8 19 / 10 20 20 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 4 PM PST Monday for Central Panhandle
Mountains.
Winter Storm Warning until 4 PM PST Monday for Northern
Panhandle.
WA...Winter Storm Warning until 4 PM PST Monday for Northeast
Mountains.
Wind Advisory until 4 AM PST Monday for Lower Garfield and
Asotin Counties-Upper Columbia Basin-Washington Palouse.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1123 PM CST SUN DEC 1 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 307 PM CST SUN DEC 1 2013
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT UPPER TROUGH DROPPING DOWN THROUGH WESTERN BRITISH
COLUMBIA...WITH NEARLY ZONAL FLOW DOWNSTREAM ACROSS THE NORTHERN
U.S.. WITHIN THIS ZONAL FLOW...THERE ARE SOME WEAK SHORTWAVES...ONE
OVER SOUTHEAST BRITISH COLUMBIA AND A SECOND IN THE DAKOTAS. DPVA
AND WARM ADVECTION AHEAD OF THIS SECOND SHORTWAVE HAS BEEN SPREADING
MID/HIGH CLOUDS DOWNSTREAM INTO THE FORECAST AREA. SO FAR THE ONLY
SPOT PRECIPITATION HAS BEEN FALLING OUT OF THESE CLOUDS HAS BEEN
ACROSS CENTRAL NORTH DAKOTA. COMPARING THE 12Z BIS AND MPX
SOUNDINGS...MUCH MORE MOISTURE EXISTED ACROSS NORTH DAKOTA...
RELATIVELY SPEAKING AS PRECIPITABLE WATER AMOUNTS ARE ONLY 0.13
INCHES DIFFERENT. FARTHER EAST...HIGH PRESSURE HAS BUILT INTO THE
FORECAST AREA AT THE SURFACE BEHIND LAST NIGHTS COLD FRONT. THE
STRATUS THAT WAS COMING IN AHEAD OF THE HIGH PRESSURE AREA HAS
STALLED MOSTLY NORTH OF HWY 29 IN WI. 925MB TEMPS ARE ABOUT 3C
COOLER TODAY AND AS RESULT...THE SUN HAS ONLY ALLOWED THE
TEMPERATURES TO CLIMB INTO THE 30S.
MODELS ARE ALL IN GOOD AGREEMENT DIVING THE POTENT UPPER TROUGH
OVER WESTERN BRITISH COLUMBIA DIGGING INTO THE PACIFIC NORTHWEST
AND NORTHERN ROCKIES. THIS IN TURN SENDS THE SHORTWAVE IN SOUTHERN
BRITISH COLUMBIA EASTWARD...CROSSING THE FORECAST AREA MONDAY
AFTERNOON. PRIOR TO THIS SHORTWAVE...WE FIRST MUST DEAL WITH THE
SHORTWAVE IN THE DAKOTAS WHICH IS PROGGED TO COME ACROSS THE AREA
THIS EVENING. IT APPEARS ALL THE SHORTWAVE WILL BRING IS CONTINUED
MID/HIGH CLOUDS AS THE LOW LEVELS REMAIN DRY AS SHOWN NICELY IN
THE 12Z MPX SOUNDING. NOW OVERNIGHT...INCREASING 280-295K
ISENTROPIC LIFT OVER THE DAKOTAS AHEAD OF THE APPROACHING BRITISH
COLUMBIA SHORTWAVE WILL LIKELY DEVELOP PRECIPITATION FROM THE
DAKOTAS INTO CENTRAL MINNESOTA. MODELS HAVE SLOWED DOWN THE
PRECIPITATION SPREAD SOUTHEAST INTO THE FORECAST AREA PRIOR TO
12Z...WHICH SEEMS REASONABLE AND HAVE DELAYED THE PRECIPITATION
CHANCES TO LATE IN THE NIGHT. THE BETTER CHANCES FOR PRECIPITATION
COME DURING THE DAY MONDAY AS THE SHORTWAVE CROSSES THE FORECAST
AREA...PROVIDING DPVA AND A SPREAD SOUTHEASTWARD OF THE 280-295K
ISENTROPIC LIFT INTO THE FORECAST AREA. STILL...THERE ARE
DIFFERENCES WITH THE MAIN PRECIP AXIS. THE 01.12Z
CANADIAN...01.00Z/01.12Z ECMWF SUGGEST AN ALIGNMENT FROM CENTRAL
MN INTO NORTHEAST IA/FAR SOUTHWEST WI...THE 01.12Z NAM PLACES IT
MOSTLY NORTH OF I-94...AND THE 01.12Z GFS IS SORT OF A SPLIT
BETWEEN THE TWO. WITH NO CLEAR SIGNAL ON WHICH MODEL GROUP MIGHT
VERIFY...HAVE FOLLOWED A COMPROMISE. THIS COMPROMISE RESULTS IN
LOW CHANCES...20-40...BECAUSE OF THE VARIABILITY OF LOCATION.
FUTURE SHIFTS SHOULD BE ABLE TO RAISE CHANCES AND HONE IN ON AN
ALIGNMENT OF THE PRECIP AXIS.
WITH 925MB AND 850MB TEMPS PROGGED AT OR BELOW 0C ACROSS MUCH OF
THE FORECAST AREA AND EVAPORATIVE COOLING LIKELY TO TAKE PLACE
WHERE IT DOES PRECIPITATE...THINKING THAT THE PRECIPITATION WILL
MAINLY FALL IN THE FORM OF SNOW. THERE MAY BE SOME MIXING WITH
RAIN POSSIBLE IN THE AFTERNOON IF TEMPERATURES WARM INTO THE MID
TO POSSIBLY UPPER 30S AS EXPECTED. NO MODEL IS THAT HEAVY ON
QPF...MOSTLY ON THE ORDER OF A TENTH...MAYBE TWO TENTHS AT MOST.
WITH SNOW TO WATER RATIOS LIKELY IN THE 10-15 TO 1 RANGE AND
DURING THE DAY WHEN THE SUN CAN HAVE SOME IMPACT ON LIMITING
ACCUMULATIONS...THINKING MOSTLY UP TO 1 INCH OF SNOWFALL.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 307 PM CST SUN DEC 1 2013
MAIN LONG TERM FORECAST CONCERNS ARE PRECIPITATION CHANCES AND
TEMPERATURES THROUGH WEDNESDAY...THEN TEMPERATURES BEYOND THAT
AS ARCTIC AIR BEGINS TO FLOW IN.
THE BIGGEST ISSUE TO THE FORECAST IS THE EVOLUTION OF THE
TROUGHING THAT DROPS INTO THE PACIFIC NORTHWEST AND NORTHERN
ROCKIES ON MONDAY. GOOD MODEL CONSENSUS EXISTS THAT THE WESTERN
PART OF THE TROUGH IS GOING TO DIG DEEPLY THROUGH THE WESTERN
U.S.. THE EASTERN PART OF THE TROUGH...ON THE OTHER
HAND...DIFFERENCES SHOW UP WHICH HAVE HUGE IMPLICATIONS TO THE
FORECAST. THE 01.12Z NAM HAS THE EASTERN PORTION OF THE TROUGH
MOVING INTO THE DAKOTAS ON TUESDAY AS A CLOSED LOW...WHEREAS THE
01.12Z GFS/ECMWF/CANADIAN STILL HOLD IT BACK IN SOUTHWEST MONTANA.
THUS...THE NAM EXITS PRECIP THE QUICKEST COME WEDNESDAY AND BEGINS
THE FLOW OF ARCTIC AIR IN THE EARLIEST. BASED ON AVAILABLE MODEL
GUIDANCE...HAVE MOSTLY DISCOUNTED THE NAM AS AN OUTLIER. OF THE
01.12Z GFS/ECMWF/CANADIAN...THE GFS BECOMES THE NEXT FASTEST OF
EXITING THE PRECIPITATION AND BRINGING THE COLD AIR ON
WEDNESDAY...RESULTING FROM MOVING THE UPPER LOW OUT TO THE EAST
QUICKER. HARD TO SAY WHICH OF THIS MODEL GROUP IS CORRECT.
HOWEVER...ITS WORTH NOTING THAT THE ECMWF/CANADIAN HAVE SPED UP
FROM YESTERDAY...REGARDING THE UPPER LOW...EXITING THE
PRECIPITATION AND BRINGING IN THE COLD AIR. THUS...THE FORECAST
FOR MONDAY NIGHT THROUGH WEDNESDAY TAKES A BLEND OF THE
GFS/ECMWF/CANADIAN AND CONTINUITY.
FOR MUCH OF MONDAY NIGHT THROUGH TUESDAY NIGHT...THE FORECAST
AREA REMAINS IN THAT 280-295K ISENTROPIC LIFT ZONE LEFTOVER FROM
MONDAY. THE STRONGEST OF THE LIFT OVERALL STAYS CENTERED NORTH OF
I-90. PRECIPITATION CHANCES INCREASE BECAUSE MOISTURE CONTINUES TO
INCREASE AND DEEPEN. PRECIPITABLE WATER INCREASES FROM NEAR 0.5
INCH ON MONDAY TO 0.6-0.7 INCHES ON TUESDAY. WARMER AIR FLOWING IN
ON SOUTH TO SOUTHEAST 925-850MB WINDS SHOULD ALLOW PRECIPITATION
THAT IS A SNOW OR RAIN/SNOW MIX MONDAY NIGHT INTO TUESDAY MORNING
TO SWITCH MOSTLY OVER TO ALL RAIN BY TUESDAY AFTERNOON. THE ONE
EXCEPTION TO THIS IS OVER TAYLOR COUNTY WHICH IS FARTHEST FROM THE
WARMER AIR ADVECTING IN FROM THE SOUTH. WEDNESDAY IS VERY TRICKY
WITH TEMPERATURES AND PRECIPITATION CHANCES...AS IT HIGHLY DEPENDS
ON THE TIMING OF THE UPPER LOW AND AN EXPECTED COLD FRONTAL
PASSAGE. TEMPERATURES COULD EITHER BE IN THE MID 30S - LOW 40S OR
MID 20S - LOW 30S...WHICH OF COURSE GREATLY AFFECTS PRECIPITATION
TYPE. AS MENTIONED EARLIER...STUCK WITH A COMPROMISE.
SINCE THE LIFT OVERALL IS WEAK FOR MUCH OF THE MONDAY NIGHT
THROUGH WEDNESDAY TIME PERIOD...MUCH OF THE PRECIPITATION SHOULD
BE ON THE LIGHT SIDE. TAYLOR COUNTY AGAIN AS THE GREATEST SHOT OF
SEEING SNOW...BUT WITH THE LIGHT ASPECT TO THE PRECIPITATION AND
LOWER SNOW TO WATER RATIOS...ACCUMULATIONS SHOULD STAY LESS THAN 1
INCH IN EACH 6 HOUR PERIOD. NOW IF YOU TOTAL THIS UP...SNOWFALL
AMOUNTS BY WEDNESDAY EVENING END UP IN THE 4-6 INCH RANGE...BUT
SETTLING...AND POSSIBLY MIXING WITH RAIN ON TUESDAY AFTERNOON...
PUTS A LOT OF DOUBT FOR NEED OF AN ADVISORY AT THIS TIME.
AFTER WEDNESDAY...ITS ALL ABOUT THE ARCTIC AIR AS A LONGWAVE
TROUGH SETS UP FROM THE SOUTHWESTERN U.S. INTO NORTHERN ONTARIO.
THE MAIN REASON FOR ARCTIC AIR COMING IS A POLAR STREAM UPPER
TROUGH THAT DROPS SOUTH OUT OF CENTRAL CANADA AND PROGRESSES
ACROSS THE UPPER MIDWEST ON FRIDAY. AS THIS POLAR TROUGH
APPROACHES...850MB/925MB TEMPS JUST GRADUALLY DROP RIGHT THROUGH
FRIDAY. BY 00Z SATURDAY...850MB STANDARDIZED ANOMALIES ARE DOWN TO
-2.5. IF WE CAN GET SOME SNOW ON WEDNESDAY...EVEN 1 INCH TO STAY
ON THE GROUND...TEMPERATURES COULD BE QUITE A BIT COLDER THAN
FORECAST FOR THURSDAY THROUGH SATURDAY. DOES NOT LOOK LIKE ANY
REAL MEASURABLE SNOW THREAT UNTIL SUNDAY AT THE EARLIEST...AND
THATS IF THE ECMWF IS CORRECT IN TIMING OF BRINGING OUT A
STRONGER WAVE OUT OF THE WESTERN TROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1124 PM CST SUN DEC 1 2013
A SERIES OF WEAK WEATHER SYSTEMS WILL PASS OVER THE TAF SITES
THROUGH THE PERIOD. IT APPEARS A SLOW LOWERING OF THE CIGS WILL
OCCUR WITH THESE SYSTEMS AS A WARM FRONT APPROACHES AND LIFT
GRADUALLY INCREASES. THE BEST TARGET FOR SOME MEANINGFUL LOWERING
APPEARS TO BE LATER ON MONDAY AND HAVE INCLUDED THIS IN THE TAFS
AS A BIT MORE MOISTURE ARRIVES FROM THE SOUTHWEST. FORECAST
CONTAINS SHRA AS TEMPERATURES SHOULD REMAIN ALMOST CONSTANT
OVERNIGHT MONDAY NIGHT WITH WARM SOUTHEAST FLOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1044 PM CST SUN DEC 1 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 220 PM CST SUN DEC 1 2013
SEVERAL FORECAST ISSUES THIS PERIOD INCLUDING SOUTHERN EXTENT OF
LOW CLOUDS OVERNIGHT...WHETHER LAKE EFFECT SNOW SHOWERS AFFECT
DOOR COUNTY...AND TIMING OF NEXT SYNOPTIC-SCALE SYSTEM.
WEAK LOW-LEVEL WAA TONIGHT AS WINDS BECOME SW-W. AS A RESULT
WOULD EXPECT THE LOW CLOUDS TO STICK AROUND OVER MUCH OF THE
AREA. DIURNAL CU THAT FORMED ALONG SOUTHERN EXTENT OF LOW CLOUDS
MAY DISSIPATE BUT HIGHER CLOUDS UPSTREAM MOVING IN.
REPEATED RUNS OF HRRR AND OTHER SHORT-TERM MODELS INDICATE SOME
LAKE EFFECT SNOW SHOWERS ASSOCIATED WITH POSSIBLE MESOVORTEX OVER
NORTH-CENTRAL LK MICHIGAN TONIGHT WHICH COULD CLIP DOOR COUNTY.
DELTA-T`S ARE MARGINAL BUT WILL CONTINUE WITH SMALL CHANCE OF
SNOW SHOWERS OR FLURRIES IN NORTHERN DOOR. MIN TEMPS SHOULD DROP
INTO THE 20S MOST AREAS AWAY FROM LK MICHIGAN.
ON MONDAY...WAA INCREASES AS NEXT SYSTEM APPROACHES FROM THE
WEST. SOME LIGHT SNOW OR FLURRIES EXPECTED TO MOVE INTO AT LEAST
THE WESTERN HALF OF THE AREA BY LATE AFTERNOON. STILL SOME
QUESTION AS TO HOW FAST SYSTEM BEGINS TO AFFECT AREA...SO WILL
CONTINUE TO USE MODEL BLEND WHICH RESULTS IN TIMING SIMILAR TO
PREVIOUS FORECAST. HIGH TEMP FORECAST A BLEND OF BEST PERFORMING
MOS GUIDANCE WHICH IS NOT FAR OFF FROM PREVIOUS FORECAST.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 220 PM CST SUN DEC 1 2013
A VERY CHALLENGING FORECAST PERIOD THROUGH MID WEEK DUE TO
TIMING ISSUES WITH A DEVELOPING STORM SYSTEM AND PCPN TYPE. THE
POTENTIAL EXISTS FOR WINTER HEADLINES OVER NORTH CENTRAL WISCONSIN
FOR MAINLY SNOW.
STARTING MONDAY NIGHT...NAM AND GFS CONTINUE TO REMAIN A BIT QUICKER
WITH SPREADING THE BAND OF SNOW OVER THE AREA FASTER WITH THE WARM
AIR ADVECTION. OLD ECMWF IS ABOUT 12 HOURS SLOWER WHILE THE GEM
WAS THE AVERAGE. LATEST ECMWF IS CLOSER TO THE GEM TIME WITH THE
INITIAL WAA TOWARD MONDAY NIGHT.
AVAILABLE FORECAST SOUNDINGS DO INDICATE SNOW AT THE START FOR
THE PCPN TYPE WITH AROUND AN INCH OR TWO OF ACCUMULATION BY
TUESDAY MORNING...WITH THE 2 INCH AMOUNTS TOWARD CENTRAL AND NORTH
CENTRAL AND POINTS NORTHWEST. THE AIR COLUMN LIKELY WILL REMAIN
COLD ENOUGH FOR SNOW FOR ANOTHER 2 INCHES ACROSS THE NORTH. ITS
POSSIBLE AN ADVISORY WILL BE NEEDED FOR NORTH CENTRAL AND PARTS OF
FAR NORTHEAST WISCONSIN FOR THIS INITIAL BAND. SNOW AMOUNTS APPEAR
TO DIMINISH DUE TO CONTINUED WAA AND PCPN CHANGING TO RAIN OR A
RAIN SNOW MIX. THE NAM FORECAST SOUNDING FOR RHI CHANGES THE SN
OVER BRIEFLY ZR THEN RAIN TUESDAY NIGHT THEN BACK TO SNOW LATE.
WITH FROST DEPTHS A FEW INCHES DEEP OVER MANY LOCATIONS DUE TO THE
COLD LATER HALF OF NOVEMBER...POTENTIAL OF BRIEF PERIOD ICY ROADS
DUE TO ZR AND COLD GROUND. NOT CONFIDENT OF THE ZR AT THIS TIME
BUT IF THIS BECOMES MORE OF A THREAT...WINTER WEATHER ADVISORIES
MAY BE NEEDED FOR THAT ELEMENT ALONE TOWARD TUESDAY AS WELL.
BLEND OF MEDIUM RANGE MODELS WITH THE H850 LOW TRACKS SUGGESTS THE
SYSTEM PCPN/SNOW TO REMAIN NORTHWEST OF THE AREA BUT CLOSE ENOUGH
TO PRODUCE ANOTHER INCH OR TWO OVER NORTH CENTRAL WISCONSIN. AT
THIS TIME...UP TO 6 INCHES OF SNOW POSSIBLE OVER PARTS OF NORTH
CENTRAL WISCONSIN FROM MONDAY NIGHT INTO WEDNESDAY MORNING. BUT
DUE TO THE SNOW AMOUNTS WILL BE SPREAD OVER A 36-48 PERIOD...NO
WATCH ISSUED AT THIS TIME. ANTICIPATE A LONG DURATION ADVISORY OR
TWO SHORTER WINTER ADVISORIES MAY BE NEEDED TO HANDLE THE SNOW
ACCUMULATION AND OR MIX CLOSER TO THE EVENT.
BITTERLY COLD ARCTIC AIR WILL THEN POUR INTO THE ARE IN THE WAKE
OF THE SYSTEM. WITH NEED TO HAVE A HEALTHY NORTH TO SOUTH GRADIENT
IN TEMPS LATER IN THE WEEK DUE TO THE COLDER TEMPERATURES OVER
THE ANTICIPATED SNOW COVER OVER NORTH CENTRAL WISCONSIN TO
PROBABLY LITTLE OR NO SNOW OVER CENTRAL AND EAST CENTRAL
WISCONSIN. WINDS APPEAR TO WESTERLY FOR SIGNIFICANT LAKE EFFECT
SNOWS TO REACH FAR NORTH CENTRAL WISCONSIN DURING THE ARTIC SURGE.
MEDIUM RANGE RUNS BEGIN TO DEVELOP RETURN FLOW PCPN AGAIN LATE
NEXT WEEKEND AND FOR THE START OF THE NEXT WEEK...WILL KEEP THE
FORECAST DRY THROUGH NEXT WEEKEND FOR NOW.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1042 PM CST SUN DEC 1 2013
LOW CLDS ACRS THE NE PART OF THE FCST AREA WL RELEASE OFF TO THE
NE A BIT AS FLOW ABV THE SFC SWINGS ARND TO THE SW. THAT COULD
ALLOW SOME FG TO DEVELOP LATER TNGT. LOWERING CLDS AHEAD OF THE
NEXT WX SYSTEM WL OVERSPREAD THE AREA MON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
645 AM EST MON DEC 2 2013
.SYNOPSIS...
HIGH PRESSURE EXTENDING FROM THE MID-ATLANTIC STATES TO THE GULF
COAST STATES WILL WEAKEN ACROSS THE CAROLINAS TODAY AS WEAK LOW
PRESSURE DEVELOPS OFF THE COAST. THE AREA OF LOW PRESSURE WILL
MOVE NORTHWARD TONIGHT...ALLOWING HIGH PRESSURE TO SLIDE EAST AND
MOVE OFF SHORE TUESDAY. A WARMING TREND IS EXPECTED FOR MID-WEEK
WITH A COLD FRONT APPROACHING FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHORT WAVE TROUGH MOVING ACROSS THE AREA TODAY WILL INDUCE
CYCLOGENESIS OFFSHORE. THE LOW PRESSURE AREA WILL TRACK NORTHEAST.
FORCING AND STRONG LIFT WILL REMAIN TO THE NORTHEAST OF THE REGION
TODAY. WEST COMPONENT TO LOW LEVEL FLOW WILL LIMIT MOISTURE
ADVECTION...PRECIPITABLE WATER REMAINS LOW. RADAR SHOWING SHOWERS
MOVING EAST ACROSS CENTRAL GEORGIA. RAP MODEL SUGGESTS SHOWERS
WILL REMAIN WEST OF THE AREA HOWEVER LATEST HRRR SUGGESTS A FEW
SHOWERS IN THE CSRA THIS MORNING. BASED ON RADAR TRENDS WILL PUT
SLIGHT CHANCE SHOWERS NEAR AGS THIS MORNING. DESPITE CONSIDERABLE CLOUDS
AT TIMES...ESPECIALLY THIS MORNING...EXPECT TEMPERATURES TO BE A
DEGREE OR TWO WARMER THAN YESTERDAY DUE TO DOWNSLOPE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UPPER FLOW ON TUESDAY BECOMES MORE ZONAL FROM THE WEST ACROSS THE
AREA WITH RISING 500MB HEIGHTS. A DIGGING TROUGH ACROSS THE WEST
WILL BEGIN TO INDUCE DOWNSTREAM RIDGING AND DEVELOPING WARM
ADVECTION ACROSS THE GULF COAST STATES INTO THE TENNESSEE VALLEY.
A WARM FRONT WILL DEVELOP WEST OF THE AREA AND MODELS ARE SHOWING
SOME ISENTROPIC LIFT ASSOCIATED WITH THE WARM ADVECTION WHILE THE
NAM ACTUALLY SHOWS SOME PRECIPITATION. MOISTURE IS QUITE LIMITED
WITH PRECIPITABLE WATER VALUES BETWEEN A HALF INCH AND 0.75 INCHES
SO THINK MEASURABLE PRECIPITATION IS LOW BUT WILL INCLUDE SLIGHT
CHANCE POPS IN THE WESTERN MIDLANDS AND CSRA TUESDAY EVENING.
GIVEN WARM ADVECTION PATTERN EXPECT TEMPERATURES TUESDAY AND
WEDNESDAY TO BE ABOVE NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LITTLE CHANGE IN THE EXTENDED FORECAST THINKING. CONTINUED RUN TO
RUN INCONSISTENCIES AMONG THE OPERATIONAL MEDIUM RANGE GUIDANCE AND
ABOVE AVERAGE MODEL SPREAD DURING THIS PERIOD LEADS TO LOWER THAN
AVERAGE CONFIDENCE...ESPECIALLY FRI-SUN. THE MAIN FORECAST PROBLEM
REVOLVES AROUND THE TIMING OF A COLD FRONT FRI-SAT PERIOD.
THERE IS GENERAL AGREEMENT IN A LARGE AND EXPANSIVE UPPER TROUGH
ACROSS THE WESTERN UNITED STATES WITH DOWNSTREAM RIDGING ACROSS THE
SOUTHEASTERN STATES INTO THE MID ATLANTIC REGION. A SLOW MOVING
FRONTAL BOUNDARY WILL PUSH INTO THE OHIO AND TENNESSEE VALLEYS ON
WEDNESDAY BEFORE STALLING JUST WEST OF THE FORECAST AREA THURSDAY
INTO FRIDAY AS THE DEEP SOUTHWESTERLY FLOW ALOFT BECOMES NEARLY
PERPENDICULAR TO THE ORIENTATION OF THE FRONT.
SURFACE HIGH PRESSURE CENTERED JUST OFF THE CAROLINA COAST ON
WEDNESDAY WILL GRADUALLY SHIFT FURTHER OFFSHORE AND ALLOW A MOIST
SOUTHERLY FLOW TO RETURN OVER THE FORECAST AREA THROUGH THE END OF
THE WEEK. PRECIPITABLE WATER VALUES SURGE TO BETWEEN 1.5 AND 1.75
INCHES THURSDAY AND MAINTAIN THAT THROUGH THE WEEKEND. THE BEST
CHANCES OF RAIN FIGURE TO REMAIN JUST WEST OF THE FORECAST AREA
WED-THU WITH INCREASING CHANCES OF RAIN FRIDAY INTO THE WEEKEND AS
THE COLD FRONT EVENTUALLY PUSHES INTO THE FORECAST AREA AT SOME
POINT. PLENTY OF UNCERTAINTY REMAINS REGARDING THE TIMING OF A
FRONTAL PASSAGE AND ASSOCIATED PRECIPITATION AND EVEN POSSIBLE
THUNDERSTORMS WITH CONSIDERABLE SPREAD IN THE GUIDANCE.
WILL PLAN TO CARRY A FAIRLY PERSISTENT FORECAST AND KEEP THE POPS
THAT WERE INHERITED FROM PREVIOUS FORECAST AT THIS POINT WHILE
ADDING A NEW DAY 7 WITH CHANCE POPS WITH THE POTENTIAL FRONT
LINGERING IN THE AREA. REASONABLE HIGH CONFIDENCE IN SIGNIFICANT
WARM UP NEXT WEEK UNDER THE INFLUENCE OF THE UPPER RIDGE AND
SOUTHERLY FLOW SO HAVE INCREASED MAX/MIN TEMPS SEVERAL DEGREES TO
BETTER FIT WITHIN THE SPECTRUM OF THE MODEL GUIDANCE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
UPPER LEVEL TROUGH CONTINUES TO MOVE ACROSS THE GULF STATES WITH
MORE PRECIPITATION THAN ORIGINALLY ANTICIPATED. DRY AIR REMAINS
ACROSS THE TAF SITES...HOWEVER EXPECT SOME SHOWERS TO MOVE THROUGH
THE AREA THIS MORNING INTO EARLY THIS AFTERNOON. CONFIDENCE IN
RAIN REMAINS LOW SO HAVE INCLUDED VCSH AT ALL TAF SITES WITH CIGS
ANTICIPATED VFR. UPPER LEVEL TROUGH WILL MOVE OFFSHORE LATE THIS
AFTERNOON WITH CLOUDINESS LINGERING THROUGH THE END OF THE PERIOD
WITH CIGS REMAINING VFR.
EXTENDED AVIATION OUTLOOK...LOW CONFIDENCE FORECAST FOR THE
EXTENDED OUTLOOK WITH PERIODS OF MVFR...POSSIBLY
LOWER...CONDITIONS TUESDAY THROUGH FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
518 AM EST MON DEC 2 2013
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE CAROLINA COAST THIS MORNING
AND LIFT NORTHEAST TODAY...WHILE GENERALLY DRY HIGH PRESSURE PREVAILS
OVER THE AREA THROUGH LATE WEEK. A COLD FRONT SHOULD THEN SHIFT OVER
THE AREA DURING THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...SATELLITE IMAGERY THIS MORNING PORTRAYS A TEXTBOOK BAROCLINIC
LEAF SIGNATURE OVER THE SE UNITED STATES AS WEAK CYCLOGENESIS IS
UNDERWAY ALONG THE WEST WALL OF THE GULF STREAM. UNDER THE LEAF OF
THICK MID AND HIGH CLOUDS...SURFACE CONDITIONS WERE RAIN-FREE ACROSS
CENTRAL GEORGIA AS PCPN FALLS INTO A VERY DRY LAYER BETWEEN 5-16 KFT.
LIGHT RADAR RETURNS MAINLY VIRGA AT THIS POINT WITH OTHER RAINS
BREAKING OUT IN NW GEORGIA AND EASTERN ALABAMA AS MODELS INDICATED.
UPPER FORCING/PVA COULD RESULT IN SOME SPRINKLES OR SPOTTY LIGHT
SHOWERS AT SOME LOCATIONS THROUGH MID MORNING. AT THIS POINT...
MEASURABLE RAINFALL CHANCES LOOK QUITE SMALL AND OUR POPS SILENT.
TEMPS MILD 50-53...FALLING INTO THE 40S LATE. LOCALIZED BUILD-DOWN
STRATUS HAD DEVELOPED OVER CHARLESTON COUNTY...UPDATED TO ADD
MENTION OF PATCHY FOG EARLY THIS MORNING.
THE PROGRESSIVE UPPER WAVE WILL SWEEP OFF THE COAST BY MIDDAY WITH
CLOUDS QUICKLY CLEARING OUT FOR THE AFTERNOON ACROSS THE FORECAST
AREA. FORECAST VERTICAL MOISTURE PROFILES DRY OUT FAST AND MODEL
CLOUD FORECAST PROGS SUCH AS THE REGIONAL GEM INDICATE SUNSHINE
SHOULD BE PREVALENT DURING THE AFTERNOON HOURS. IN THE WAKE OF
THE OFFSHORE LOW PRES...LOW LEVEL WINDS WILL BECOME W TO WNW AND
THIS WILL ALLOW FOR A LOWER RISK FOR MANY LINGERING LOWER CLOUDS BY
EARLY AFTERNOON. LACK OF SIGNIFICANT COLD AIR ADVECTION AND THE WEAK
DOWNSLOPE COMPONENT SHOULD ALLOW HIGH TEMPS TO REACH THE MID 60S
MOST AREAS PROVIDED THE CLOUDS SCATTER OUT EARLIER OR ON TIME...
RATHER THAN LATER. INCREASING LAYERED CLOUDS EXPECTED TONIGHT WITH
LOWS IN THE 40S AND WITH JUST SPRINKLE CHANCES...POPS SILENT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
QUIET/DRY WEATHER IS EXPECTED THROUGH MIDWEEK AS WEAK HIGH PRESSURE
SETTLES OVER THE AREA BEHIND A DEPARTING SFC LOW WELL TO OUR
NORTHEAST. MODELS CONTINUE TO INDICATE A FAIRLY SIGNIFICANT WARMING
TREND THROUGH THROUGH THURSDAY AS SOUTHERLY FLOW DEVELOPS ALONG THE
WESTERN EDGE OF SFC HIGH PRESSURE WHILE SLIGHT MID LVL RIDGING
OCCURS FROM THE SOUTH/SOUTHWEST. HOWEVER...PEAK HEATING MAY BE
LIMITED A FEW DEGREES EACH DAY DUE TO CIRRUS THAT DEVELOPS WITH A
STRONG H25 JET POSITIONED JUST TO THE NORTHWEST OR MID CLOUDS
ASSOCIATED WITH MODEST ISENTROPIC OVER THE AREA. DESPITE CLOUD
COVER...PERSISTENT SOUTHERLY FLOW WILL LIKELY WARM OVERALL HIGH
TEMPS INTO THE UPPER 60S TO AROUND 70 ON TUESDAY...THEN LOW 70S ON
WEDNESDAY...FOLLOWED BY MID/UPPER 70S BY THURSDAY. OVERNIGHT LOWS
WILL ALSO REMAIN MILD EACH NIGHT...IN THE LOW/MID 50S INLAND TO
UPPER 50S/LOWER 60S ALONG THE IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CONDITIONS WILL REMAIN QUIET/DRY THROUGH FRIDAY AS THE AREA REMAINS
SITUATED ALONG THE WESTERN EDGE OF SFC HIGH PRESSURE. PERSISTENT
SOUTHERLY FLOW ALONG WITH MID LVL RIDGING FROM THE SOUTH/SOUTHWEST
WILL LIKELY LEAD TO ABOVE NORMAL TEMPS AHEAD OF A COLD FRONT
APPROACHING FROM THE WEST. IN GENERAL...EXPECT HIGH TEMPS IN THE
UPPER 70S ON FRIDAY WITH OVERNIGHT LOWS IN THE UPPER 50S/LOWER 60S.
PRECIP CHANCES SHOULD THEN INCREASE THIS WEEKEND AS A COLD FRONT
BEGINS SHIFTING THROUGH THE SOUTHEASTERN UNITED STATES. UNCERTAINTY
REMAINS HIGH WITH THE POSITION OF THE FRONT ON SATURDAY AND SUNDAY
BUT THE GENERAL CONSENSUS IS THAT THE FRONT SHOULD STALL JUST SOUTH
OF THE FORECAST AREA BEFORE LIFTING NORTH AS A WARM FRONT AHEAD OF
SFC LOW SHIFTING OVER THE DEEP SOUTH AND THEN THE SOUTHEASTERN UNITED
STATES EARLY NEXT WEEK. HAVE THUS MAINTAINED CHANCE POPS SATURDAY
AND SUNDAY AS MOISTURE REMAINS ALONG/NEAR THE FRONT. A SLIGHT CHANCE
OF SHOWERS WILL ALSO BE POSSIBLE ON MONDAY WHILE CONDITIONS
GRADUALLY IMPROVE WITH THE LOW SHIFTING OFFSHORE. OVERALL HIGH TEMPS
SHOULD PEAK NEAR 70 ON SATURDAY AHEAD OF THE FRONT...THEN COOL OFF
INTO THE LOW 60S ON SUNDAY AND MONDAY AS THE SFC LOW SHIFTS OVER THE
SOUTHEAST AND OFFSHORE.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS IFR AT 06Z AND LATEST RAP SOUNDINGS SUGGEST CIGS MAY
LOWER A BIT MORE BEFORE IMPROVING TOWARD DAYBREAK AS A LIGHT
NW FLOW DEVELOP. UPSTREAM CIGS OVER INLAND AREAS ARE CURRENTLY
VFR WITH MVFR VSBYS. WE IMPROVE CONDITIONS MID MORNING THEN VFR
CONDITIONS BY LATE MORNING THROUGH THIS EVENING.
KSAV...MVFR OR IFR CIGS IN AND OUT UNDER A STRONG INVERSION BUT
CONDITIONS SHOULD IMPROVE BY MID MORNING AND VFR WILL PERSIST FOR
THE REMAINDER OF THE DAY INTO THIS EVENING.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL THROUGH
FRIDAY. MVFR CIGS/VSBYS ARE POSSIBLE SATURDAY AS SHOWERS OCCUR ALONG
A PASSING COLD FRONT.
&&
.MARINE...
A LIGHT NW FLOW IS FORECAST IN THE WAKE OF AN OFFSHORE LOW RACING
TO THE NE TODAY. A WEAK GRADIENT SHOULD ENSURE A LACK OF ANY
SIGNIFICANT SURGES AFTER MID MORNING. SEAS ALSO CONTINUE TO SLOWLY
SUBSIDE. SEAS 3 TO 4 FT COMING DOWN TO 2 TO 3 FT BY TONIGHT.
TUESDAY THROUGH SATURDAY...WINDS/SEAS WILL REMAIN WELL BELOW SMALL
CRAFT ADVISORY LEVELS AS A SFC LOW CONTINUES TO SHIFT NORTHEAST AND
AWAY FROM THE REGION THROUGH TUESDAY. WEAK HIGH PRESSURE WILL THEN
SETTLE OVER THE WATERS THROUGH THURSDAY WITH WINDS/SEAS EXPECTED TO
REMAIN AT OR BELOW 15 KT WITH SEAS NO HIGHER THAN 3 FT. WINDS/SEAS
WILL THEN GRADUALLY INCREASE/BUILD TO 15-20 KT AND 4-5 FT ON FRIDAY
AS THE PRESSURE GRADIENT BEGINS TO ENHANCE BETWEEN HIGH PRESSURE
OVER THE WESTERN ATLANTIC AND A COLD FRONT APPROACHING INLAND.
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
SATURDAY AS THE COLD FRONT STALLS OVER OR JUST SOUTH OF THE WATERS.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE HIGH THROUGH MID-WEEK DUE TO ASTRONOMICAL
INFLUENCES OF THE UPCOMING PERIGEE AND NEW MOON /PERIGEAN SPRING
TIDES/. WE HAVE ISSUED A COASTAL FLOOD ADVISORY FOR CHARLESTON
COUNTY AS THE TIDE LIKELY TO TOUCH 7 FT MLLW GIVEN THE LATEST
DEPARTURES STILL AT 1/2 FOOT ABOVE PREDICTED. COASTAL FLOOD
ADVISORIES MIGHT BE NEEDED TUESDAY MORNING AND AGAIN WEDNESDAY
MORNING WITH THOSE HIGH TIDES AS WELL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...COASTAL FLOOD ADVISORY UNTIL 8 AM EST THIS MORNING FOR SCZ050.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
745 AM CST MON DEC 2 2013
.UPDATE...
ISSUED AT 735 AM CST MON DEC 2 2013
MID LEVEL CLOUDS ARE DEVELOPING ACROSS IOWA AND RADAR REFLECTS
THIS WITH AN INCREASE IN OVERALL RETURNS. 12Z DVN SOUNDING HAS A
DRY LAYER FROM ROUGHLY 950-850MB WITH SATURATION OCCURRING ABOVE
THAT. THIS DRY LAYER IS NARROWER THAN WHAT ANY OF THE MODELS
INDICATED IN THEIR RESPECTIVE 6 AND 12 HR FORECASTS.
RECENT TRENDS IN THE RAP MODEL GENERALLY SUPPORTS THE CURRENT
FORECAST OF A BAND OF RAIN DEVELOPING AND MOVING ACROSS THE AREA
TODAY. THE ONLY DIFFERENCE IS THAT THE DEVELOPMENT MAY OCCUR A BIT
LATER THAN WHAT THE CURRENT FORECAST HAS. HOWEVER...THE NARROWER
DRY LAYER IN THE MORNING SOUNDING WOULD TAKE LESS TIME TO
SATURATE SO PRECIPITATION MAY START SOONER THAN WHAT THE RAP IS
SUGGESTING.
&&
.SYNOPSIS...
ISSUED AT 316 AM CST MON DEC 2 2013
06Z SFC ANALYSIS HAS WEAK LOWS NEAR KVIH...KRSL...AND KPIR.
DEVELOPING WARM FRONTS RAN ACROSS NORTHEAST KANSAS THROUGH CENTRAL
MISSOURI AND ANOTHER FROM THE DAKOTAS INTO EASTERN NEBRASKA. DEW
POINTS WERE IN THE 20S ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
WITHS 30S AND HIGHER FROM THE OHIO VALLEY INTO THE DEEP SOUTH AND
SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST MON DEC 2 2013
CURRENT RADAR TRENDS SHOW PRECIPITATION DECREASING IN COVERAGE AS
THE FIRST ROUND OF FORCING WEAKENS. THUS MAINLY DRY CONDITIONS
SHOULD BE SEEN THROUGH SUNRISE AND THE FIRST PART OF THE MORNING.
FROM MID TO LATE MORNING FORCING BEGINS TO INCREASE AGAIN WITH THE
APPROACH OF THE NEXT UPPER LEVEL DISTURBANCE. THERE IS REASONABLE
AGREEMENT AMONG THE MODELS THAT AS THE FORCING INCREASES...VERY
LIGHT RAIN SHOULD BREAK OUT FROM CENTRAL IOWA INTO THE WESTERN PARTS
OF THE AREA AND INCREASE IN COVERAGE THROUGH MID DAY.
MOISTURE AVAILABILITY IS LIMITED BUT THE FORCING INCREASES FURTHER
DURING THE AFTERNOON. SO...THERE SHOULD BE A BAND OF LIGHT RAIN THAT
WILL MOVE ACROSS THE AREA FROM LATE MORNING THROUGH THE AFTERNOON.
AS THE UPPER LEVEL DISTURBANCE EXITS THE AREA THIS EVENING THE AREAL
COVERAGE OF THE LIGHT RAIN WILL DECREASE THROUGH MID EVENING. THERE
MAY BE A LULL IN PRECIPITATION FROM MID EVENING THROUGH EARLY
MORNING BEFORE THE NEXT UPPER LEVEL DISTURBANCE ARRIVES. THIS
DISTURBANCE SHOULD EITHER ALLOW A MIX TO PERSIST ACROSS THE NORTH OR
DEVELOP A MIX PRIOR TO SUNRISE ON TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 316 AM CST MON DEC 2 2013
A STRONG ARCTIC FRONT WILL SWEEP THROUGH THE MIDWEST...BRINGING A
RETURN TO BRISK COLD TEMPERATURE FOR THE REMAINDER OF THE WEEK.
WHEN THIS BEGINS...THE FROPA...REMAINS A GIANT TROUBLESOME
DIFFERENCE IN THE 00Z GUIDANCE SUITE. THE PERIOD THIS DIFFERENCE WILL
AFFECT IS WEDNESDAY. THERE ARE TWO CAMPS...THE FASTER
NAM/GFS...WHICH MOVE THE FRONT INTO THE CWA TUESDAY NIGHT...AND THE
FAR SLOWER UKMET AND ECMWF WHICH MOVE THE FRONT THROUGH THE CWA
WEDNESDAY AFTERNOON. THIS ROUGHLY 12 HOUR DIFFERENCE CREATES
POTENTIAL FOR A 20 DEGREE BUST ON TEMPS FOR WEDNESDAY. WE COULD
CONCEIVABLY BEGIN THE DAY IN THE MID 30S TO MID 40S...AND FALL LIKE
A ROCK ALL DAY...OR SHOULD THE SLOWER SOLUTIONS WORK OUT...AN
AFTERNOON HIGHS WELL INTO THE 50S COULD BE SEEN IN ILLINOIS. GIVEN
THE POSITIVELY TILTED UPPER TROF...I STILL FEEL THE FASTER SOLUTIONS
ARE NOT OUT OF THE QUESTION. THUS...I WILL GO A BIT MILDER WEDNESDAY
THAN THE FAST/COLD NAM...BUT MUCH COOLER THAN THE SLOW ECMWF. IN
ALL...THIS DAY STILL DOES NOT OFFER MUCH CHANCE FOR SIGNIFICANT
RAIN/SNOW...BUT A SMALL POP FOR 0.01 OR SO REMAINS IN THE FORECAST
WITH THE FRONT.
TEMPERATURES TUESDAY WILL BE QUITE MILD...WARM SECTORED...WITH 40S
NORTH TO MID AND UPPER 50S CENTRAL AND SOUTH. THIS AIR HANGS ON
UNTIL THE FROPA...LEADING TO THE POTENTIAL CHALLENGE OF WEDNESDAYS
HIGHS AND HOURLY TEMPERATURES. BEHIND THE FRONT...TEMPERATURES WILL
CERTAINLY CRASH...TO THE 20S AND TEENS INITIALLY...BUT BY THURSDAY
NIGHT THROUGH THE WEEKEND...LOWS IN THE SINGLE DIGITS ARE CERTAINLY
LIKELY. HIGHS IN THE UPPER TEENS TO LOWER 20S WILL FINISH OUT THE
WEEK. WIND CHILLS OF -10 TO +5 WILL BE FOUND EACH NIGHT FROM
THURSDAY NIGHT THROUGH SATURDAY NIGHT.
LOW POPS ARE RETAINED IN THE SOUTH FOR THE NORTH EDGE OF A POSSIBLE
OVER RUNNING LIGHT SNOW EVENT THURSDAY INTO FRIDAY. OTHERWISE...THE
NEXT MORE LIKELY OVER RUNNING LIGHT SNOW EVENT APPEARS SET FOR
SUNDAY AND MONDAY.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 537 AM CST MON DEC 2 2013
MVFR VSBYS MAY BRIEFLY IMPROVE TO VFR PRIOR TO 18Z/02. HOWEVER...
AN APPROACHING DISTURBANCE WILL DEVELOP WIDESPREAD MVFR CONDITIONS
AROUND 18Z/02 WITH RAIN. THE POSSIBILITY DOES EXIST THAT BRIEF
PERIODS OF IFR CONDITIONS MAY DEVELOP IN THE RAIN PRIOR TO 00Z/03.
AFTER 00Z/03 MVFR/IFR CONDITIONS WILL PERSIST WITH SOME
IMPROVEMENT TO VFR ACROSS SOUTHEAST IOWA FOLLOWING THE FRONTAL
PASSAGE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
848 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE
TODAY. LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE
ON TUESDAY... BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN
SECTIONS. BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW
PRESSURE SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT
CROSSING NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS
WILL THEN SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
JUST A QUICK UPDATE TO EXTEND THE WINTER WEATHER ADVISORY AND THE
FREEZING RAIN ADVISORY UNTIL 10 AM. TEMPERATURES ARE STILL IN THE
30-32 DEGREE RANGE BUT SHOULD RISE ABOVE FREEZING AROUND 10 AM.
&&
UPDATE...PCPN IS BEGINNING TO WEAKEN ALONG THE MIDCOAST...LINING
UP WELL WITH PREVIOUS RUNS OF THE HRRR. HAVE DECIDED TO EXTEND THE
WINTER WX ADVISORY FOR THE CAPITAL REGION AND SRN
FRANKLIN/SOMERSET COUNTIES UNTIL 9 AM. TEMPS REMAIN AOB
FREEZING...WITH PCPN EXPECTED TO LINGER THERE INTO THE MID
MORNING. AN ADDITIONAL INCH OR SO OF ACCUMS AND A TRACE OF ICE
WILL BE POSSIBLE. ALSO HAVE ADDED INTERIOR WRN ME S OF THE MTNS TO
A FZRA ADVISORY FOR WIDESPREAD AREAS OF FZDZ. SECONDARY ROADS ARE
BECOMING QUITE ICY...AS THE DZ IS MUCH MORE EFFICIENT AT ACCRETION
AT THESE MARGINAL TEMPS.
PREVIOUS DISCUSSION...SFC TROF AND ASSOCIATED WEAK AREA OF LOW
PRES OFF OF CAPE COD IS CONTINUING TO PUMP PCPN INTO THE MIDCOAST.
THAT LOW PRES HAS ALLOWED WINDS TO BACK AROUND TO A MORE NLY
DIRECTION...EFFECTIVELY LOCKING THE COLDER AIR IN PLACE AT THE
SFC. WHILE TEMPS ALONG THE COAST ARE IN THE MID 30S...JUST INLAND
THEY ARE AOB FREEZING. ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH
HI-RES MODEL GUIDANCE LIKE THE HRRR AND RAP SUGGESTING H9 AND H8
TEMPS RISING ABOVE FREEZING BY 12Z FOR MUCH OF THE COAST AND
COASTAL PLAIN. THAT MEANS THE CAPITAL REGION WHERE IT HAS BEEN
SNFL MUCH OF THE NIGHT WILL SEE A GRADUAL TRANSITION TOWARDS A MIX
WITH RA AND FZRA. GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN
H8...SO GIVEN THAT LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE
REMOVED MUCH OF THE PL FROM THE FORECAST. KGYX RADAR ALSO
INDICATES THE 0.5 DEG CORRELATION COEFFICIENT INFERRED MELTING
LAYER GRADUALLY INCREASING IN RANGE. THIS SUPPORTS THE NWP
FORECAST WARMING ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND
KAUG SOONER RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT
HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MEZ013-014-021-022.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR MEZ012-
018>020.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ150-
152.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
619 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE TODAY.
LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE ON TUESDAY...
BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN SECTIONS.
BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW PRESSURE
SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT CROSSING
NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL THEN
SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...PCPN IS BEGINNING TO WEAKEN ALONG THE MIDCOAST...LINING
UP WELL WITH PREVIOUS RUNS OF THE HRRR. HAVE DECIDED TO EXTEND THE
WINTER WX ADVISORY FOR THE CAPITAL REGION AND SRN
FRANKLIN/SOMERSET COUNTIES UNTIL 9 AM. TEMPS REMAIN AOB
FREEZING...WITH PCPN EXPECTED TO LINGER THERE INTO THE MID
MORNING. AN ADDITIONAL INCH OR SO OF ACCUMS AND A TRACE OF ICE
WILL BE POSSIBLE. ALSO HAVE ADDED INTERIOR WRN ME S OF THE MTNS TO
A FZRA ADVISORY FOR WIDESPREAD AREAS OF FZDZ. SECONDARY ROADS ARE
BECOMING QUITE ICY...AS THE DZ IS MUCH MORE EFFICIENT AT ACCRETION
AT THESE MARGINAL TEMPS.
PREVIOUS DISCUSSION...SFC TROF AND ASSOCIATED WEAK AREA OF LOW
PRES OFF OF CAPE COD IS CONTINUING TO PUMP PCPN INTO THE MIDCOAST.
THAT LOW PRES HAS ALLOWED WINDS TO BACK AROUND TO A MORE NLY
DIRECTION...EFFECTIVELY LOCKING THE COLDER AIR IN PLACE AT THE
SFC. WHILE TEMPS ALONG THE COAST ARE IN THE MID 30S...JUST INLAND
THEY ARE AOB FREEZING. ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH
HI-RES MODEL GUIDANCE LIKE THE HRRR AND RAP SUGGESTING H9 AND H8
TEMPS RISING ABOVE FREEZING BY 12Z FOR MUCH OF THE COAST AND
COASTAL PLAIN. THAT MEANS THE CAPITAL REGION WHERE IT HAS BEEN
SNFL MUCH OF THE NIGHT WILL SEE A GRADUAL TRANSITION TOWARDS A MIX
WITH RA AND FZRA. GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN
H8...SO GIVEN THAT LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE
REMOVED MUCH OF THE PL FROM THE FORECAST. KGYX RADAR ALSO
INDICATES THE 0.5 DEG CORRELATION COEFFICIENT INFERRED MELTING
LAYER GRADUALLY INCREASING IN RANGE. THIS SUPPORTS THE NWP
FORECAST WARMING ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND
KAUG SOONER RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MEZ013-
014-021-022.
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR MEZ012-
018>020.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ150-
152.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CARIBOU ME
602 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE EAST OF THE REGION TODAY. ANOTHER LOW
WILL TRACK EAST OF THE REGION TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
UPDATED POPS TO GO NEAR 100 PERCENT THIS MORNING BASED ON CURRENT
RADAR IMAGERY. ALSO TWEAKED HOURLY TEMPERATURE GRIDS.
A WEAK AREA OF LOW PRESSURE WILL CONTINUE TO MOVE EAST OF
THE GULF OF MAINE TODAY. CURRENT RADAR IMAGERY WAS SHOWING
PRECIPITATION...MAINLY IN THE FORM OF SNOW CONTINUING ACROSS MUCH
OF CENTRAL AND DOWNEAST MAINE...ALTHOUGH COULDNT RULE OUT SOME
PATCHY FREEZING RAIN ACROSS PORTIONS OF INTERIOR DOWN EAST THROUGH
EARLY THIS MORNING. LATEST HRRR SHOWS PRECIPITATION CONTINUING
INTO MID MORNING AND WITH TEMPERATURES NOT EXPECTED TO BUDGE TOO
MUCH DECIDED TO EXTEND THE WINTER WEATHER ADVISORY UNTIL 11 AM.
THE HIGHEST SNOW TOTALS WILL BE ACROSS CENTRAL PENOBSCOT AND
WASHINGTON COUNTIES. HOWEVER...WE LOWERED TOTAL SNOWFALL
ACCUMULATIONS BASED ON CALLS TO LOCAL/FED LAW ENFORCEMENT AGENCIES
WHICH WERE INDICATING SNOWFALL AMOUNTS BELOW OUR CURRENT
FORECASTED AMOUNTS AS OF EARLY THIS MORNING. THE PRECIPITATION
ACROSS DOWNEAST AREAS SHOULD DIMINISH LATER THIS MORNING AND WITH
TEMPERATURES THIS AFTERNOON EXPECTED TO RISE ABOVE FREEZING ANY
LINGERING PRECIPITATION THIS AFTERNOON DOWNEAST WILL BE IN THE
FORM OF RAIN. ACROSS NORTHERN AREAS EXPECT LIGHT SNOW TO CONTINUE
INTO THIS AFTERNOON. ACROSS NORTHERN AREAS EXPECT ACCUMULATIONS
TODAY TO RANGE FROM 1 TO 3 INCHES. HIGHS TODAY WILL RANGE FROM THE
LOWER 30S NORTH AND MID TO UPPER 30S DOWNEAST.
TONIGHT WILL BE CLOUDY WITH A CONTINUED CHANCE FOR SOME LIGHT SNOW
MAINLY ACROSS NORTHERN AREAS AND THE CHANCE FOR SOME LIGHT RAIN
SHOWERS ACROSS CENTRAL AND DOWNEAST. THERE COULD EVEN BE A LITTLE
LIGHT FREEZING RAIN OR DRIZZLE LATE TONIGHT ACROSS NORTHERN AREAS.
LITTLE TEMPERATURE CHANGE IS EXPECTED TONIGHT WITH LOWS IN THE UPPER
20S TO AROUND 30 NORTH AND LOW TO MID 30S DOWNEAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
LINGERING PRECIP PSBL ACROSS MAINLY NRN AREAS TUE AM AS INITIAL
WEAK LOW PRES AFFECTING THE REGION TODAY DISSIPATES WHILE
STRONGER LOW PRES WELL OFF THE MID ATLC STATES TUE AM BEGINS TO
TRACK NEWD TOWARD SRN NS... LATEST MODEL CONSENSUS CONTS TO
INDICATE THAT THIS SYSTEM WILL PASS WELL E OF THE AREA (ACROSS ERN
NS WED AM) W/ JUST A GLANCING BLOW ACROSS FAR ERN AND SERN AREAS
LATE TUE INTO TUE NGT. WILL BRING HIGHEST POPS (LIKELY) INTO OUR
SERN ZNS TUE AM INTO TUE EVE W/ CHC POPS CENTRAL AND N AND NE W/
SLGT CHC TO NIL POPS FAR W AND NW... LACK OF ANY REAL COLD AIR
ACROSS THE AREA ALSO SUGGESTS PRECIP ACROSS OUR SERN TO E CENTRAL
AREAS MAY BE RAIN OR A MX OF RAIN AND WET SNOW. IN ANY CASE...ATTM
DOES NOT APPEAR THAT THIS WILL BE A SIGNIFICANT WNTR SYSTEM FOR
OUR AREA... ANY PRECIP ASSOCIATED W/ THIS SYSTEM IS EXPECTED TO
EXIT THE AREA ERLY WED W/ A RIDGE OF HIGH PRES THEN FCST TO BUILD
ACROSS OUR FA WED. THIS WILL RESULT IN DRY COND W/ TEMPS A LITTLE
ABV SEASONAL NORMS W/ HIGHS RANGING FROM THE MID 30S N TO AROUND
40 S... &&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RIDGE OF HIGH PRES ACROSS THE FA WED EVE IS EXPECTED TO SHIFT E OF
THE REGION WED NGT AS DEEP LOW PRES OVR THE WRN GRT LKS LIFTS
NEWRD AND SWEEPS AN OCLD FRONT EWRD ACROSS THE NERN STATES AND OUR
AREA BY ERLY THU PER THE FASTER GFS AND BY LATE THU EVE PER THE
SLOWER ECMWF. THIS FRONTAL BNDRY IS THEN FCST TO BECOME NRLY
STATIONARY FROM THE SRN GULF OF MAINE SWWRD ACROSS THE SERN STATES
AND INTO THE WRN GULF OF MEX. GUIDANCE THEN SUGGESTS WAVES OF SFC
LOW PRES LIFTING NEWRD UP ALONG THIS FRONTAL BNDRY MAY BRUSH
MAINLY OUR SRN AREAS FRI INTO SAT W/ THE THREAT OF SOME PRECIP W/
DRIER AND COLDER AIR FINALLY OVERSPREADING THE ENTIRE REGION LATER
SAT THRU SUN... TEMPS WILL REMAIN ABV SEASONAL NORMS AT THE START
OF THE LONG TERM PD THEN GRADUAL TREND TO SEASONAL AND THEN TO BLO
SEASONAL NORMS BY SUN. POPULATED OUR LONG TERM GRIDS W/ THE
SUPER BLEND CONSENSUS AND MADE MINIMAL ADJUSTMENTS...&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
NEAR TERM: WIDESPREAD IFR/MVFR CONDITIONS ARE EXPECTED AT THE TERMINALS
TODAY IN LOW CIGS AND LGT SNOW NORTH AND LGT SNOW/RAIN KBGR/KBHB
TERMINALS. THESE FLIGHT CONDITIONS WILL PERSIST THROUGH TONIGHT.
SHORT TERM: MVFR TO PSBL IFR TUE INTO TUE NGT AS STRONG LOW PRES
TRACKS E OF THE REGION AND BRUSHES THE REGION W/ SOME PRECIP. VFR
CONDS EXPECTED WED INTO THU W/ ANOTHER ROUND OF MVFR TO IFR
EXPECTED LATER THU INTO FRI AS A COMPLEX FRONTAL SYSTEM CROSSES
THE REGION.
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
TONIGHT. VISIBILITY WILL BE REDUCED AT TIMES TO 1 TO 3 NM IN LIGHT
RAIN THROUGH TONIGHT.
SHORT TERM: SCA CONDS ARE EXPECTED TO DVLP LATER TUE AND CONT THRU
MUCH OF WED AS DEEP LOW PRES TRACKS E OF THE WATERS...
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
MEZ005-006-011-015>017-032.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA
SHORT TERM...KHW
LONG TERM...KHW
AVIATION...DUDA/KHW
MARINE...DUDA/KHW
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
555 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL GRADUALLY MOVE EAST OF THE GULF OF MAINE TODAY.
LOW PRESSURE WILL DEVELOP ALONG THE MID ATLANTIC COASTLINE ON TUESDAY...
BRINGING A CHANCE OF PRECIPITATION MAINLY TO EASTERN SECTIONS.
BRIEF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER LOW PRESSURE
SYSTEM PASSES NORTH ON THURSDAY WITH AN OCCLUDED FRONT CROSSING
NEW ENGLAND. HIGH PRESSURE OVER THE NORTHERN PLAINS WILL THEN
SLOWLY BUILD TOWARDS THE EAST THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...PCPN IS BEGINNING TO WEAKEN ALONG THE MIDCOAST...LINING
UP WELL WITH PREVIOUS RUNS OF THE HRRR. HAVE DECIDED TO EXTEND THE
WINTER WX ADVISORY FOR THE CAPITAL REGION AND SRN
FRANKLIN/SOMERSET COUNTIES UNTIL 9 AM. TEMPS REMAIN AOB
FREEZING...WITH PCPN EXPECTED TO LINGER THERE INTO THE MID
MORNING. AN ADDITIONAL INCH OR SO OF ACCUMS AND A TRACE OF ICE
WILL BE POSSIBLE.
PREVIOUS DISCUSSION...SFC TROF AND ASSOCIATED WEAK AREA OF LOW
PRES OFF OF CAPE COD IS CONTINUING TO PUMP PCPN INTO THE MIDCOAST.
THAT LOW PRES HAS ALLOWED WINDS TO BACK AROUND TO A MORE NLY
DIRECTION...EFFECTIVELY LOCKING THE COLDER AIR IN PLACE AT THE
SFC. WHILE TEMPS ALONG THE COAST ARE IN THE MID 30S...JUST INLAND
THEY ARE AOB FREEZING. ALOFT TEMPS ARE SLOWLY CREEPING UP...WITH
HI-RES MODEL GUIDANCE LIKE THE HRRR AND RAP SUGGESTING H9 AND H8
TEMPS RISING ABOVE FREEZING BY 12Z FOR MUCH OF THE COAST AND
COASTAL PLAIN. THAT MEANS THE CAPITAL REGION WHERE IT HAS BEEN
SNFL MUCH OF THE NIGHT WILL SEE A GRADUAL TRANSITION TOWARDS A MIX
WITH RA AND FZRA. GUIDANCE HAS H9 TEMPS WARMING MORE QUICKLY THAN
H8...SO GIVEN THAT LACK OF A DEEP COLD LAYER NEAR THE SFC I HAVE
REMOVED MUCH OF THE PL FROM THE FORECAST. KGYX RADAR ALSO
INDICATES THE 0.5 DEG CORRELATION COEFFICIENT INFERRED MELTING
LAYER GRADUALLY INCREASING IN RANGE. THIS SUPPORTS THE NWP
FORECAST WARMING ALOFT...AND EXPECT THAT MIXING WILL BEGIN AROUND
KAUG SOONER RATHER THAN LATER.
ATTM ADVISORY IS SET TO EXPIRE AT 11Z. WILL CONTINUE IT UNTIL THAT
TIME AS THERE REMAINS SN...FZRA...AND FZDZ ACROSS THE ADVISORY
AREA. HOWEVER...WRF AND HRRR GUIDANCE CONTINUES PCPN UNTIL NEARLY
NOON ACROSS PARTS OF THE MIDCOAST. AN EXTENSION MAY BE NECESSARY
IF TEMPS TO DO NOT WARM ANY FURTHER AT THE SFC.
OTHERWISE...EVENTUALLY DIURNAL HEATING WINS OUT AND PCPN NEAR THE
COAST WILL FLIP TO ALL RA IF IT HASN/T ENDED ALREADY BY THAT TIME.
SFC TROF WILL LINGER NEARBY...AS IT SLOWLY DRIFTS TOWARDS DOWNEAST
ME. THIS COULD MEAN SCT/ISOLD SHWRS CONTINUE MUCH OF THE DAY FROM
JACKMAN TO KRKD.
&&
.SHORT TERM /TUESDAY/...
SFC TROF IS SLOW TO WEAKEN AND LIFT NEWD TONIGHT. IF IT LINGERS
OVER DOWNEAST ME SOME SCT TO ISOLD SHWRS ARE POSSIBLE THRU THE
NIGHT. PCPN WILL BE LIGHT...AND SHOULD STAY IN THE FORM OR RA OR
SN. ONE CONCERN COULD BE IF THE COLUMN DRIES OUT. THIS COULD BRING
A PERIOD OF DZ/FZDZ RATHER THAN SHWRS. THIS COULD BRING ANOTHER
ROUND OF SLICK CONDITIONS FOR THE INTERIOR MIDCOAST.
BY TUE MORNING COASTAL LOW PRES WILL BE ORGANIZING S OF SRN NEW
ENGLAND. WITH A LACK OF DOWNSTREAM RIDGING AND DELAYED ARRIVAL OF
NRN STREAM S/WV TROF THERE IS NOT MUCH TO KEEP THIS SYSTEM FROM
SLIDING OUT TO SEA. LATE INTERACTION WITH THE NRN STREAM WILL
SWING THE LOW PRES TOWARDS THE CANADIAN MARITIMES BY LATE TUE
NIGHT. IT IS AS IT DOES SO THAT PCPN SHIELD MAY BRUSH PORTIONS OF
THE MIDCOAST. HAVE KEPT LIKELY POP OFFSHORE FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE GRADUALLY INTENSIFIES EAST OF THE GULF OF MAINE
TUESDAY NIGHT. 00Z MODEL SUITE IN GOOD AGREEMENT WITH THE TRACK OF
THIS SYSTEM...KEEPING MUCH OF THE PRECIPITATION EAST OF OUR
REGION...OVER DOWNEAST MAINE.
A WEAK RIDGE OF HIGH PRESSURE CROSSES THE REGION WEDNESDAY
MORNING...BEFORE CLOUDS SPILL OVER THE RIDGE IN THE AFTERNOON.
PLENTY OF WARM AIR WILL ARRIVE WITH THE APPROACH OF AN OCCLUDED
FRONT...BRINGING SHOWERS OR PATCHY FREEZING RAIN OVER INTERIOR
SECTIONS ON WEDNESDAY NIGHT. TEMPERATURES ALOFT WILL MAKE IT
DIFFICULT FOR ANY SNOW...HOWEVER SURFACE TEMPERATURES MAY FALL TO
BELOW THE FREEZING LEVEL OVER NORTHERN AREAS DURING THE OVERNIGHT HOURS.
HIGH PRESSURE WILL GRADUALLY BUILD EAST FROM THE NORTHERN PLAINS
DURING THE PERIOD THURSDAY AND INTO THE WEEKEND. THIS WILL BRING
COOLER TEMPERATURES TO THE REGION...HOWEVER NOT A DIRECT BLOW OF
ARCTIC AIR TO NEW ENGLAND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR OR LOWER ALONG THE COAST AND INTERIOR
WILL BE VERY SLOW TO SCATTER OUT AND LIFT TODAY. EXPECTING MVFR
AND VFR CONDITIONS TO PROGRESS SW TO NE ALONG THE COAST THRU THE
AFTERNOON. INVOF KAUG...FZRA WILL BE POSSIBLE THIS MORNING...AS
WARMTH ALOFT PUSHES NWD. THIS AFTERNOON CLOUDS FROM THE SW WILL
PUSH ACROSS THE MTNS...WITH KHIE SEEING A PERIOD OF MVFR
CONDITIONS. WILL HAVE TO WATCH FOR MVFR OR LOWER CONDITIONS TO
WORK BACK INTO COASTAL TERMINALS AGAIN TONIGHT...AS ONSHORE FLOW
DEVELOPS AHEAD OF NEXT OCEAN LOW PRES.
LONG TERM...AREAS OF MVFR CONDITIONS ARE POSSIBLE TUESDAY NIGHT
OVER DOWNEAST MAINE. AREAS OF MVFR CONDITIONS ARE ALSO POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF AN
OCCLUDED FRONT.
&&
.MARINE...
SHORT TERM...WEAK LOW PRES IN THE GULF OF ME WILL KEEP WINDS
GUSTING AT OR JUST BELOW 25 KTS EARLY THIS MORNING. HOWEVER...THIS
NE FLOW WILL ALSO KEEP SEAS ABOVE 5 FT INTO THE
AFTERNOON...ESPECIALLY N OF PORT CLYDE. WILL KEEP SCA GOING FOR
THE OUTER WATERS UNTIL SEAS BEGIN TO SUBSIDE.
LONG TERM...THERE MAY BE BORDERLINE SCA CONDITIONS OVER EASTERN
SECTIONS WITH THE PASSAGE OF AN OFFSHORE SYSTEM TUESDAY NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MEZ013-
014-021-022.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ150-
152.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS GAYLORD MI
945 AM EST MON DEC 2 2013
.SYNOPSIS...
ISSUED AT 300 AM EST MON DEC 2 2013
WEAK HIGH PRESSURE OVER THE WESTERN GREAT LAKES REGION WILL KEEP OUR
WEATHER DRY BUT CLOUDY TODAY. PRECIPITATION CHANCES WILL INCREASE
TUESDAY AS A WARM FRONT LIFTS THROUGH MICHIGAN...WITH A MIX OF RAIN
AND SNOW EVENTUALLY CHANGING OVER TO ALL RAIN ON WEDNESDAY.
PRECIPITATION WILL CHANGE BACK OVER TO ALL SNOW WEDNESDAY NIGHT AS A
COLD FRONT BLASTS THROUGH THE REGION.
&&
.UPDATE...
ISSUED AT 944 AM EST MON DEC 2 2013
BROAD HIGH PRESSURE IN PLACE ACROSS THE GREAT LAKES THIS MORNING.
GENERALLY QUIET...BUT THERE IS A SUBTLE SHORT WAVE TROUGH MOVING
THROUGH THE REGION THAT HAS BROUGHT ABOUT A SUBTLE BUMP UP IN
INVERSION HEIGHTS AND WEAK UPWARD FORCING. ENOUGH TO PRODUCE A
HYBRID BROAD AREA OF LAKE INDUCED/SYNOPTIC LIGHT PRECIP ACROSS
PARTS OF THE CWA. MAINLY FLURRIES AS INVERSION HEIGHTS ARE JUST UP
INTO THE -12C/-13C RANGE...ALTHOUGH THERE MIGHT BE SOME
INTERMINGLED -FZDZ AS WELL.
HAVE EXTENDED FLURRIES/LIGHT FREEZING DRIZZLE OUT THROUGH THE REST
OF THE MORNING. RUC13 DATA THEN SUGGESTS FORCING WILL FALL APART
BY EARLY AFTERNOON AND WE SHOULD SEE A DOWNWARD TREND TO THE
LIGHT/NUISANCE PRECIP. WILL SEE.
UPDATE ISSUED AT 619 AM EST MON DEC 2 2013
PATCHY FREEZING DRIZZLE HAS EXPANDED ACROSS THE STRAITS AND FAR
NRN LWR MICHIGAN EARLY THIS MORNING PER LATEST KAPX 88D BASE REF
LOOP. SURFACE OBS HAVE YET TO REPORT THIS PHENOMENA...BUT A COUPLE
OF EARLY MORNING SPOTTER REPORTS CONFIRM THAT SOME VERY LIGHT
PRECIP IS REACHING THE GROUND. HAVE SPREAD PATCHY FREEZING DRIZZLE
INTO THESE AREAS AND HAVE EXTENDED THE OCCURRENCE THRU 15Z AS
SHALLOW LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE SUBSIDENCE
INVERSION AND SOME VERY WEAK SHEAR CONTINUES AT THE TOP OF THE
MOIST LAYER. REST OF THE DAY WILL BE CLOUDY WITH TEMPS ONLY
WARMING INTO THE LOW TO MID 30S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EST MON DEC 2 2013
KINDA "DIRTY" HIGH PRESSURE EXTENDING ACROSS THE NORTHWOODS AT THIS
EARLY HOUR...WITH PLENTY OF CLOUDS STUCK BELOW STRONG H8 SUBSIDENCE
INVERSION (PER LOCAL 00Z SOUNDING). STILL SOME WEAK LAKE PROCESSES
ONGOING IN MARGINALLY COLD ENOUGH ATMOSPHERE...WITH EVEN A WELL
EVIDENT LAKE-INDUCED MESO LOW SPINNING HARMLESSLY ACROSS NORTHERN
LAKE MICHIGAN. ENOUGH LIFT/LAKE MOISTURE CONTRIBUTION TO KICK OFF A FEW
FLURRIES FOR SOME...BUT THAT`S ABOUT IT. MID AND UPPER LEVEL PATTERN
JUST ABOUT AS NONDESCRIPT AS THE SURFACE FEATURES...WITH GENERALLY
LIGHT WEST TO NORTHWEST FLOW ALOFT...WITH MUCH STRONGER JET ENERGY
WELL TO OUR WEST (LEADING CORE OF 100+ KNOT UPPER JET PUNCHING INTO
THE NORTHERN ROCKIES). JUST NOT A WHOLE LOT OF CHANGE EXPECTED
THROUGH THIS EVENING...WITH WAA PROCESSES RAMPING UP TOWARD TUESDAY
MORNING WELL AHEAD OF ORGANIZING CENTRAL PLAINS LOW PRESSURE.
THUS...FORECAST CONCERNS REMAIN RATHER TRIVIAL...CENTERING ON
CLOUD/TEMPERATURE TRENDS AS WELL AS SOME WEAK LAKE PROCESSES THROUGH
THIS EVENING. POSSIBLE LATE NIGHT WAA PRECIP WILL ALSO NEED
ADDRESSING.
BASICALLY...WHAT YOU SEE IS WHAT YOU GET TODAY. HAVING A HARD TIME
BELIEVING RATHER AGGRESSIVE DRYING BELOW INVERSION LEVEL NOTED IN
MODEL DERIVED SOUNDINGS. NAM-BUFR INITIATION FAR TOO DRY ALREADY AT
INVERSION LEVEL...AND GIVEN VERY LIGHT WIND FIELDS TODAY (SIMPLY NO
MECHANICAL MIXING)...FEEL CURRENT CLOUD DECK WILL BE AWFULLY HARD
TO "BURN" OFF. WILL CONTINUE TO TREND MORE PESSIMISTICALLY WITH
CLOUD COVER...JUST FEATURING A FEW AFTERNOON BREAKS...BUT STILL
CALLING IT MOSTLY CLOUDY. ONLY PRECIP CONCERNS APPEARS TIED TO
NORTHWEST PUSH OF CURRENT NORTHERN LAKE MICHIGAN MESO-LOW. WILL
INTRODUCE FLURRY WORDING INTO MACKINAC COUNTY THIS MORNING AS THIS
FEATURE MOVES ASHORE. OTHERWISE...DESPITE THE CLOUDY DAY...DRY
CONDITIONS LOOK TO PREVAIL. NOT A WHOLE LOT OF DIURNAL TEMPERATURE
RESPONSE...WITH AFTERNOON READINGS RUNNING IN THE LOWER AND MIDDLE
30S.
STATUS-QUO THROUGH THIS EVENING...WITH PERHAPS A FEW MORE BREAKS
IN THE OVERCAST BEFORE HIGH LEVEL CLOUDS SPREAD ACROSS THE REGION IN
DEVELOPING TOP-DOWN SATURATION REGIME. GUIDANCE TRYING TO SATURATE
THE COLUMN RIGHT TOWARDS SUNRISE DOWN NEAR MANISTEE AS ISENTROPIC
UPGLIDE INCREASES AHEAD OF DEVELOPING CENTRAL PLAINS STORM SYSTEM.
MAIN SHOW SHOULD REMAIN OFF TO OUR WEST...BUT CANNOT COMPLETELY RULE
OUT SOME LIGHT SNOWS BY SUNRISE ACROSS THE FAR SOUTHWEST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 300 AM EST MON DEC 2 2013
TUESDAY AND WEDNESDAY...WEATHER BECOMES MORE ACTIVE TUESDAY AHEAD OF
A WARM FRONT LIFTING INTO THE WRN GREAT LAKES REGION. THIS FRONT IS
ASSOCIATED WITH DEEPENING LOW PRESSURE IN THE NRN PLAINS. EASTERLY
LOW LEVEL WINDS WILL GRADUALLY SHIFT SE ON TUESDAY AS THE WARM FRONT
NEARS...AND THEN TO THE SOUTH ON WEDNESDAY ONCE THE WARM FRONT LIFTS
NORTH OF OUR CWA. WARMER AIR WILL STEADILY SURGE NORTHWARD THRU OUR
CWA BEGINNING TUESDAY MORNING AND CONTINUING THRU MUCH OF WEDNESDAY.
850 MB TEMPS WILL WARM FROM ROUGHLY -4 C ACROSS NRN LWR MICHIGAN AT
12Z TUESDAY TO 6 C BY 12Z WEDNESDAY. PERSISTENT LOW CLOUDS WILL
LIMIT THE AFFECTS OF WAA AT THE SURFACE. AS THE LOW LEVEL TEMP
PROFILE CHANGES...SO WILL PRECIP TYPE AS MOISTURE AND THUS POPS
GRADUALLY INCREASE FROM SW TO NE ACROSS OUR CWA ON TUESDAY. WILL
NEED TO WATCH MODEL SOUNDINGS CLOSELY FOR THE POSSIBILITY OF SOME
SLEET OR FREEZING RAIN TUESDAY AND TUESDAY NIGHT AS WARMER AIR ALOFT
GRADUALLY WORKS ITS WAY NORTHWARD BEFORE THE BOUNDARY LAYER HAS A
CHANCE TO FULLY REALIZE THE WAA. FOR NOW...WILL KEEP PRECIP TYPE
SIMPLE GIVEN ALL OF THE UNKNOWNS THIS FAR OUT. PRECIP TYPE SHOULD
INITIALLY BE ALL SNOW...CHANGING TO A MIX OF RAIN AND SNOW...AND
EVENTUALLY ALL RAIN AS WAA WORKS ITS WAY NORTHWARD THRU OUR CWA
TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...PRECIP TYPE SHOULD BE ALL
RAIN ACROSS OUR ENTIRE CWA. LATEST NAM CONTINUES TO BE MORE
AGGRESSIVE WITH COLD FROPA...NOW BRINGING THE COLD AIR BACK INTO THE
REGION WEDNESDAY NIGHT. EXPECT RAIN WILL MIX WITH AND CHANGE BACK
OVER TO SNOW FROM NW TO SE DURING THE EVENING...WITH ALL SNOW
EXPECTED BY LATE WEDNESDAY NIGHT AS 850 MB TEMPS COOL BACK TO -4 C
BY 12Z THURSDAY. GIVEN THIS SCENARIO...HIGH TEMPS MAINLY IN THE 30S
ON TUESDAY WILL WARM INTO THE UPPER 30S AND LOWER 40S FOR WEDNESDAY
WHEN WAA WILL PEAK. OVERNIGHT LOWS TUESDAY NIGHT WILL ONLY COOL A
FEW DEGREES...DROPPING BACK INTO THE UPPER 20S TO MID 30S. TEMPS
WILL FALL BACK INTO THE 20S WEDNESDAY NIGHT AS CAA COMMENCES.
THURSDAY THRU SUNDAY...CAA CONTINUES THURSDAY AND FRIDAY AS 850 MB
TEMPS FURTHER COOL TO -20 C BY 00Z SATURDAY. LATEST ECMWF SHOWS
WESTERLY LOW LEVEL FLOW SETTING UP THURSDAY IN THE WAKE OF THE COLD
FRONT...WITH VERY LITTLE CHANGE IN THIS TRAJECTORY THRU SATURDAY
NIGHT. THIS COULD SET THE STAGE FOR A PROLONGED WESTERLY FLOW LAKE
EFFECT SNOW EVENT FOR THE LAST PART OF THE WEEK. THIS POTENTIAL
EVENT IS STILL SEVERAL DAYS OUT WITH TOO MANY UNKNOWNS TO GET TOO
SPECIFIC OR DETAILED AT THIS TIME. WILL CERTAINLY KEEP A CLOSE EYE
ON SUBSEQUENT MODEL RUNS TO SEE HOW THIS SCENARIO EVOLVES. FOR
NOW...WILL HIGHLIGHT HIGHEST POPS ACROSS OUR WESTERLY FLOW AREAS OF
ERN UPR AND NW/N CENTRAL LWR MICHIGAN. SUNDAY LOOKS LIKE A
TRANSITION DAY AS LOW LEVEL FLOW SHIFTS TO THE SOUTH AHEAD OF OUR
NEXT LOW PRESSURE SYSTEM. INCREASING SYNOPTIC LIFT AND MOISTURE ON
SUNDAY SHOULD BRING MORE WIDESPREAD SNOWS TO ALL OF NORTHERN
MICHIGAN. WITH PROGRESSIVE CAA TAKING PLACE THRU THIS TIME...
AFTERNOON HIGHS WILL COOL FROM THE LOWER 30S ON THURSDAY TO THE
UPPER TEENS TO MID 20S FOR SATURDAY. LOW TEMPS WILL BE MAINLY IN THE
TEENS FOR THE LAST PART OF THE WEEK AND THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 619 AM EST MON DEC 2 2013
LOW VFR CIGS WILL HOLD OVER ALL OF NRN LWR MICHIGAN THRU TUESDAY
MORNING AS SHALLOW LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE
SUBSIDENCE INVERSION. SOME PATCHY FREEZING DRIZZLE WILL IMPACT THE
REGION THIS MORNING...WILL LEAVE OUT OF THE TAF FOR NOW GIVEN THE
PATCHY NATURE OF THIS VERY LIGHT PRECIP. WINDS WILL REMAIN LIGHT
THRU THE FORECAST PERIOD.
&&
.MARINE...
ISSUED AT 300 AM EST MON DEC 2 2013
LIGHT WINDS CONTINUE THROUGH THIS EVENING AS WEAK SURFACE
RIDGE CUTS THROUGH THE AREA. EAST TO SOUTHEAST WINDS BEGIN TO PICK
UP TONIGHT WELL AHEAD OF LOW PRESSURE ORGANIZING OVER THE CENTRAL
PLAINS. STRONGER SOUTHEAST WINDS ARRIVE TUESDAY AND TUESDAY
NIGHT...WITH SOME SCA/S POSSIBLE DURING THIS PERIOD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...BA
SYNOPSIS...MR
SHORT TERM...MB
LONG TERM...MR
AVIATION...MR
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
646 AM EST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EST MON DEC 2 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A RELATIVELY LGT
ZONAL FLOW OVER THE UPR GRT LKS TO THE N OF THE MAIN POLAR JET OVER
THE SRN CONUS. AT THE SFC...HI PRES IS PRESENT NEAR JAMES BAY...WITH
A WEAK LO PRES TROF ORIENTED WNW TO ESE OVER UPR MI. THIS TROF HAS
BEEN THE FOCUS FOR SOME LGT -SN MIXED AT TIMES WITH -FZDZ DESPITE
RELATIVELY HI CIGS ASSOCIATED WITH A BIT OF DRIER LLVL AIR SHOWN ON
THE LOCAL 00Z RAOBS BLO SUBSIDENCE INVRN BASE JUST ABV H85. H85
TEMPS ARND -9C RELATIVE TO LK SUP TEMPS ARND 4C HAVE ALSO LIMITED
THE SN INTENSITY. GIVEN THE VERY LGT WIND FIELDS...SFC WINDS AS WELL
AS MQT RADAR IMAGERY INDICATE SOME VORTICES HAVE FORMED OVER THE
RELATIVELY WARM LK WATERS...WITH ONE CENTERED JUST E OF KEWEENAW BAY
AND ANOTHER N OF MUNISING. THERE APPEARS TO BE ANOTHER ONE OVER NRN
LK MI...WHERE THE OPEN WATER TEMP OF 7C REPORTED BY THE 45002 BUOY
AT THE NRN END OF THE LK IS ALLOWING A BIT MORE OVERWATER
INSTABILITY. SINCE THE SFC HI NEAR JAMES BAY IS DRIFTING TO THE
E...THE LLVL WINDS HAVE TENDED TO VEER MORE TO THE S-SW PER THE MQT
88D VWP...ESPECIALLY OVER THE W HALF OF THE CWA. THIS WSHFT IS
CAUSING THE RADAR ECHOES TO DRIFT SLOWLY TO THE N. THIS FLOW ALSO
APPEARS TO BE ADVECTING EVEN DRIER LLVL AIR SHOWN ON THE 00Z MPX AND
QUAD CITIES IA RAOBS TO THE N. ALTHOUGH LOTS OF SC LINGER OVER NRN
WI...THERE HAS BEEN PARTIAL CLRG OVER THE CENTRAL PART OF WI. BUT
MORE WAD CLDS ASSOCIATED WITH ISENTROPIC ASCENT BTWN THE DEPARTING
HI AND LOWER PRES IN THE NRN PLAINS AND BEST DEPICTED ON THE
285-295K SFCS /H85-65/ IS SPREADING QUICKLY TO THE E THRU MN AND
INTO WRN WI. THERE HAS EVEN BEEN SOME -SN AS FAR E AS CNTRL MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING CHCS FOR -SHSN/
-FZDZ TDAY. FOCUS FOR LATER TODAY AND TNGT SHIFTS TO POPS FOR SN
ASSOCIATED WITH THE ISENTROPIC LIFT SPREADING IN FM THE W.
TODAY...WITH THE CONTINUED TREND FOR THE H925 WINDS TO SHIFT TO THE
S THIS MRNG AND CAUSE THE LO PRES TROF TO DRIFT TO THE N...EXPECT
THE BULK OF LINGERING PCPN OVER UPR MI TO MOVE INTO LK SUP. THE BEST
CHC FOR MORE PCPN MAY BE OVER THE SE COUNTIES AS THE VORTEX NOW
PRESENT OVER NRN LK MI DRIFTS INLAND AS SHOWN BY A NUMBER OF THE HI
RES MODELS. THE QPF FM SOME OF THESE MODELS INDICATES THERE COULD BE
A FEW INCHES OF SN IN THIS AREA...BUT PRESENCE OF THE DGZ ABV THE
MOIST LYR/SHARPER LLVL UVV MAX AS WELL AS MARGINAL OVERWATER
INSTABILITY WITH H85 TEMPS PROGGED TO WARM TOWARD -7 TO -8C BY 00Z
SUG THE PCPN WL BE RELATIVELY LGT AND POSSIBLY EVEN MIXED WITH SOME
-FZDZ. ALTHOUGH THE DRIER NEAR SFC AIR BRINGING CLRG TO PORTIONS OF
CENTRAL WI MAY DRIFT A BIT FARTHER TO THE N THIS MRNG...A TREND FOR
THE SFC-H925 WINDS TO BACK TO THE SE THIS AFTN AND UPSLOPE OFF LK MI
WL LIKELY LIMIT ANY CLRG THAT MIGHT BRIEFLY IMPACT THE FAR SCENTRAL.
THE NAM ALSO SHOWS HIER MID LVL RH ON THE 285-295K SFCS PUSHING INTO
THE W HALF OF THE CWA DURING THE AFTN EVEN THOUGH THE ISENTROPIC
ASCENT APPEARS TO WEAKEN WITH TIME. WL RETAIN CHC POPS OVER THE FAR
W LATER IN THE DAY TO REFLECT THE POTENTIAL FOR SOME OF THE LGT -SN
NOW SHOWING UP AT SOME PLACES IN MN TO IMPACT THAT AREA.
TNGT...MOST OF THE NUMERICAL GUIDANCE SPREADS THE WAD PCPN INTO THE
WRN CWA TNGT WITH THE ARRIVAL OF H85-5 QVECTOR CVNGC AS WELL AS SOME
UPR DVGC IN THE LEFT EXIT REGION OF AN UPR JET SHIFTING E AWAY FM AN
UPR TROF THAT IS FCST TO DEEPEN OVER THE W. THE GFS IS STRONGEST
WITH THIS UPR DVGC AND THE ISENTROPIC ASCENT...GENERATING UP TO 0.75
INCH OF WATER EQUIVALENT PCPN AT IWD BY 12Z TUE...WHERE THE MODEL
ALSO SHOWS A CENTER OF STRONGER H85-7 FGEN. THE BULK OF THE OTHER
MODELS APPEAR TO FOCUS THE BETTER ISENTROPIC ASCENT TO THE S AND
SPIT OUT MUCH LESS PCPN...GENERALLY 0.10 TO 0.30 INCH IN THIS AREA.
CONSIDERING THE DRIER NATURE OF THE AIR TO THE S AND NCEP PREFERENCE
FOR A NON-GFS EVOLUTION...THE LOWER QPF SEEMS MORE RSNBL. BUT DID
BUMP POPS UP TO LIKELY IN THIS AREA...WITH CHC POPS DIMINISHING TO A
DRY FCST OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 639 AM EST MON DEC 2 2013
KIWD...EXPECT PREDOMINANT VFR CONDITIONS MOST OF TDAY WITH DOWNSLOPE
SE WIND. CONDITIONS WL DETERIORATE TO MVFR LATER TODAY AND THEN TO
IFR TNGT AS A BAND OF SN MOVES IN FM THE W.
KCMX...DOWNSLOPE S-SE WINDS TODAY SHOULD ALLOW VFR CONDITIONS TO
PREVAIL THROUGH MUCH OF TDAY. BUT AS THE FLOW BACKS MORE TOWARD AN
UPSLOPE E DIRECTION LATER IN THE AFTN...AN MVFR CIG IS LIKELY TO
DVLP. AS A BAND OF SN MOVES IN FM THE WSW LATER TNGT...CONDITIONS
SHOULD DETERIORATE INTO THE IFR RANGE IN THE PRESENCE OF THE
STRENGTHENING UPSLOPE E WIND.
KSAW...SHALLOW GROUND FOG/VLIFR CONTITIONS SHOULD GIVE WAY TO VFR
CONDITIONS AS THE FOG DSPTS THIS MRNG. BUT AS THE WIND BECOMES SE
AND UPSLOPES OFF LK MI...EXPECT AN MVFR CIG TO DVLP AND PERSIST THE
REST OF THE FCST PERIOD. ONCE A BAND OF SN ARRIVES FM THE W LATER
TNGT...CONDITIONS MAY AT LEAST APRCH IFR WITH THE PERSISTENT UPSLOPE
FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EST MON DEC 2 2013
A LIGHT S WIND TODAY WILL BACK TOWARD THE E AND INCREASE UP TO 30
KTS BY TUE AS THE PRES GRADIENT TIGHTENS OVER THE UPPER GREAT LAKES
BETWEEN DEPARTING HI PRES OVER SE CANADA AND A LO PRES SYSTEM MOVING
E FROM THE PLAINS. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE SOME MARGINAL GALES ON TUE INTO TUE NIGHT...
ESPECIALLY WHERE THE TERRAIN SURROUNDING THE LAKE ENHANCES THE E
FLOW. ALTHOUGH WINDS WILL DIMINISH A BIT THRU WED AS THE LO AND
FLATTER GRADIENT MOVES OVERHEAD...EXPECT A STRONGER W WIND TO 30 TO
35 KTS TO DEVELOP FOLLOWING THE PASSAGE OF THE LO INTO ONTARIO ON
WED NIGHT/THU. SINCE THIS WIND WILL ADVECT VERY COLD AIR OVER THE
RELATIVELY WARM WATERS...INCREASING INSTABILITY WILL ENHANCE THE
WINDS AND LIKELY REQUIRE GALE WARNINGS THU THRU FRI FOR AT LEAST
PORTIONS OF THE BIG LAKE. INCREASING WAVES AND THE ARRIVAL OF THE
ARCTIC AIRMASS WILL ALSO CAUSE WIDESPREAD FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 AM EST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EST MON DEC 2 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A RELATIVELY LGT
ZONAL FLOW OVER THE UPR GRT LKS TO THE N OF THE MAIN POLAR JET OVER
THE SRN CONUS. AT THE SFC...HI PRES IS PRESENT NEAR JAMES BAY...WITH
A WEAK LO PRES TROF ORIENTED WNW TO ESE OVER UPR MI. THIS TROF HAS
BEEN THE FOCUS FOR SOME LGT -SN MIXED AT TIMES WITH -FZDZ DESPITE
RELATIVELY HI CIGS ASSOCIATED WITH A BIT OF DRIER LLVL AIR SHOWN ON
THE LOCAL 00Z RAOBS BLO SUBSIDENCE INVRN BASE JUST ABV H85. H85
TEMPS ARND -9C RELATIVE TO LK SUP TEMPS ARND 4C HAVE ALSO LIMITED
THE SN INTENSITY. GIVEN THE VERY LGT WIND FIELDS...SFC WINDS AS WELL
AS MQT RADAR IMAGERY INDICATE SOME VORTICES HAVE FORMED OVER THE
RELATIVELY WARM LK WATERS...WITH ONE CENTERED JUST E OF KEWEENAW BAY
AND ANOTHER N OF MUNISING. THERE APPEARS TO BE ANOTHER ONE OVER NRN
LK MI...WHERE THE OPEN WATER TEMP OF 7C REPORTED BY THE 45002 BUOY
AT THE NRN END OF THE LK IS ALLOWING A BIT MORE OVERWATER
INSTABILITY. SINCE THE SFC HI NEAR JAMES BAY IS DRIFTING TO THE
E...THE LLVL WINDS HAVE TENDED TO VEER MORE TO THE S-SW PER THE MQT
88D VWP...ESPECIALLY OVER THE W HALF OF THE CWA. THIS WSHFT IS
CAUSING THE RADAR ECHOES TO DRIFT SLOWLY TO THE N. THIS FLOW ALSO
APPEARS TO BE ADVECTING EVEN DRIER LLVL AIR SHOWN ON THE 00Z MPX AND
QUAD CITIES IA RAOBS TO THE N. ALTHOUGH LOTS OF SC LINGER OVER NRN
WI...THERE HAS BEEN PARTIAL CLRG OVER THE CENTRAL PART OF WI. BUT
MORE WAD CLDS ASSOCIATED WITH ISENTROPIC ASCENT BTWN THE DEPARTING
HI AND LOWER PRES IN THE NRN PLAINS AND BEST DEPICTED ON THE
285-295K SFCS /H85-65/ IS SPREADING QUICKLY TO THE E THRU MN AND
INTO WRN WI. THERE HAS EVEN BEEN SOME -SN AS FAR E AS CNTRL MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING CHCS FOR -SHSN/
-FZDZ TDAY. FOCUS FOR LATER TODAY AND TNGT SHIFTS TO POPS FOR SN
ASSOCIATED WITH THE ISENTROPIC LIFT SPREADING IN FM THE W.
TODAY...WITH THE CONTINUED TREND FOR THE H925 WINDS TO SHIFT TO THE
S THIS MRNG AND CAUSE THE LO PRES TROF TO DRIFT TO THE N...EXPECT
THE BULK OF LINGERING PCPN OVER UPR MI TO MOVE INTO LK SUP. THE BEST
CHC FOR MORE PCPN MAY BE OVER THE SE COUNTIES AS THE VORTEX NOW
PRESENT OVER NRN LK MI DRIFTS INLAND AS SHOWN BY A NUMBER OF THE HI
RES MODELS. THE QPF FM SOME OF THESE MODELS INDICATES THERE COULD BE
A FEW INCHES OF SN IN THIS AREA...BUT PRESENCE OF THE DGZ ABV THE
MOIST LYR/SHARPER LLVL UVV MAX AS WELL AS MARGINAL OVERWATER
INSTABILITY WITH H85 TEMPS PROGGED TO WARM TOWARD -7 TO -8C BY 00Z
SUG THE PCPN WL BE RELATIVELY LGT AND POSSIBLY EVEN MIXED WITH SOME
-FZDZ. ALTHOUGH THE DRIER NEAR SFC AIR BRINGING CLRG TO PORTIONS OF
CENTRAL WI MAY DRIFT A BIT FARTHER TO THE N THIS MRNG...A TREND FOR
THE SFC-H925 WINDS TO BACK TO THE SE THIS AFTN AND UPSLOPE OFF LK MI
WL LIKELY LIMIT ANY CLRG THAT MIGHT BRIEFLY IMPACT THE FAR SCENTRAL.
THE NAM ALSO SHOWS HIER MID LVL RH ON THE 285-295K SFCS PUSHING INTO
THE W HALF OF THE CWA DURING THE AFTN EVEN THOUGH THE ISENTROPIC
ASCENT APPEARS TO WEAKEN WITH TIME. WL RETAIN CHC POPS OVER THE FAR
W LATER IN THE DAY TO REFLECT THE POTENTIAL FOR SOME OF THE LGT -SN
NOW SHOWING UP AT SOME PLACES IN MN TO IMPACT THAT AREA.
TNGT...MOST OF THE NUMERICAL GUIDANCE SPREADS THE WAD PCPN INTO THE
WRN CWA TNGT WITH THE ARRIVAL OF H85-5 QVECTOR CVNGC AS WELL AS SOME
UPR DVGC IN THE LEFT EXIT REGION OF AN UPR JET SHIFTING E AWAY FM AN
UPR TROF THAT IS FCST TO DEEPEN OVER THE W. THE GFS IS STRONGEST
WITH THIS UPR DVGC AND THE ISENTROPIC ASCENT...GENERATING UP TO 0.75
INCH OF WATER EQUIVALENT PCPN AT IWD BY 12Z TUE...WHERE THE MODEL
ALSO SHOWS A CENTER OF STRONGER H85-7 FGEN. THE BULK OF THE OTHER
MODELS APPEAR TO FOCUS THE BETTER ISENTROPIC ASCENT TO THE S AND
SPIT OUT MUCH LESS PCPN...GENERALLY 0.10 TO 0.30 INCH IN THIS AREA.
CONSIDERING THE DRIER NATURE OF THE AIR TO THE S AND NCEP PREFERENCE
FOR A NON-GFS EVOLUTION...THE LOWER QPF SEEMS MORE RSNBL. BUT DID
BUMP POPS UP TO LIKELY IN THIS AREA...WITH CHC POPS DIMINISHING TO A
DRY FCST OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1222 AM EST MON DEC 2 2013
KIWD...EXPECT MVFR CIGS TO CONTINUE THROUGH MUCH OF MONDAY IN SE
FLOW. LIGHT SNOW MOVING IN BY 22-23Z MON EVENING AHEAD OF
APPROACHING LOW PRES FROM THE PLAINS WILL LOWER CIGS TO 1500 FT AND
MAY REDUCE VSBY TO 3 SM.
KCMX...DOWNSLOPE ESE-SE WINDS SHOULD ALLOW FOR VFR CONDITIONS TO
PREVAIL THROUGH MUCH OF THE PD. ONSET OF SNOW AHEAD OF APPROACHING
PLAINS SYSTEM WILL LEAD TO MVFR CONDITIONS TOWARD 04Z TUE.
KSAW...LIGHT SRLY WINDS WILL MAINTAIN VFR CONDITIONS FOR THE NEXT
FEW HRS...BUT THEN LOOK FOR MVFR CIGS TO DEVELOP TOWARD SUNRISE AS
FLOW BCMS MORE VARIABLE AND THEN EVENTUALLY SE BY LATE MON MORNING.
UPSLOPE SE FLOW INTO MON EVENING WILL MAINTAIN MVFR CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EST MON DEC 2 2013
A LIGHT S WIND TODAY WILL BACK TOWARD THE E AND INCREASE UP TO 30
KTS BY TUE AS THE PRES GRADIENT TIGHTENS OVER THE UPPER GREAT LAKES
BETWEEN DEPARTING HI PRES OVER SE CANADA AND A LO PRES SYSTEM MOVING
E FROM THE PLAINS. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE SOME MARGINAL GALES ON TUE INTO TUE NIGHT...
ESPECIALLY WHERE THE TERRAIN SURROUNDING THE LAKE ENHANCES THE E
FLOW. ALTHOUGH WINDS WILL DIMINISH A BIT THRU WED AS THE LO AND
FLATTER GRADIENT MOVES OVERHEAD...EXPECT A STRONGER W WIND TO 30 TO
35 KTS TO DEVELOP FOLLOWING THE PASSAGE OF THE LO INTO ONTARIO ON
WED NIGHT/THU. SINCE THIS WIND WILL ADVECT VERY COLD AIR OVER THE
RELATIVELY WARM WATERS...INCREASING INSTABILITY WILL ENHANCE THE
WINDS AND LIKELY REQUIRE GALE WARNINGS THU THRU FRI FOR AT LEAST
PORTIONS OF THE BIG LAKE. INCREASING WAVES AND THE ARRIVAL OF THE
ARCTIC AIRMASS WILL ALSO CAUSE WIDESPREAD FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
511 AM EST MON DEC 2 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL EXTEND INTO THE AREA TODAY AND THEN GET
PUSHED OFF TO THE NORTHEAST TONIGHT AS A WARM FRONT LIFTS THROUGH
THE REGION. INCREASING SOUTHERLY FLOW AHEAD OF A STRONG COLD
FRONT WILL BRING MUCH WARMER AIR INTO THE OHIO VALLEY THROUGH MID
WEEK. THE COLD FRONT WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK TROUGH HAS SETTLED ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA. EXPECT IT WILL REMAIN THERE THROUGH THE DAY AS WEAK
RIDGING IS WORKING IN FROM THE NORTH. MULTIPLE LEVELS OF CLOUDS
SHOULD KEEP SKIES MOSTLY CLOUDY THROUGH THE DAY. CANNOT
COMPLETELY RULE OUT AN ISOLATED SHOWER DEVELOPING/MOVING INTO THE
NORTHWEST COUNTIES THIS AFTERNOON. TEMPERATURES SHOULD BE SIMILAR
TO YESTERDAYS HIGHS IN MOST LOCATIONS WHICH FOLLOWS CLOSE TO
WARMER GFS MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TROUGH NEAR THE OHIO RIVER AT THE BEGINNING OF THE PERIOD WILL
LIFT NORTH TONIGHT AS A WEAK WARM FRONT. LOOKS LIKE A FEW SHOWERS
ARE POSSIBLE NORTH OF THE BOUNDARY. THEREAFTER SOUTHERLY FLOW WILL
INCREASE FOR THE REMAINDER OF THE PERIOD WHICH WILL ADVECT A WARM
AND MOIST AIR MASS INTO THE REGION. ALTHOUGH THERE WILL BE MORE
CLOUDS THAN NOT...EXPECT READINGS TO WARM WELL ABOVE NORMAL.
CONTINUED TO FORECAST TEMPERATURES CLOSER TO WARMER GUIDANCE
NUMBERS. HAVE DISCOUNTED FAST 00Z GFS AND ITS WEDNESDAY FRONTAL
PASSAGE AS IT APPEARS TO HAVE TOO MUCH AMPLITUDE WITH A TROUGH
LIFTING THROUGH THE NORTHERN PLAINS. IT DOES APPEAR THAT SOME
SHOWERS COULD DEVELOP LATE TUESDAY NIGHT INTO WEDNESDAY AS LIFT
INCREASES WITH A LOW LEVEL JET AND A PASSING WEAK MID LEVEL
DISTURBANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THERE CONTINUES TO BE UNCERTAINTY WITH SYSTEMS IN THE LONG TERM.
00Z GFS LOOKS TOO AGGRESSIVE WITH ITS SOLUTION. THE 00Z ECMWF AND
00Z CANADIAN ARE IN FAIRLY GOOD AGREEMENT AND HAVE REASONABLE
SUPPORT FROM THE 00Z/06Z NAM AS FAR OUT AS THAT RUNS. SO HAVE
RELIED ON THE ECMWF/CANADIAN BLEND FOR THE LATTER PART OF THE
WEEK. THIS SUGGESTS THAT A COLD FRONT WILL MOVE THROUGH WEDNESDAY
NIGHT AND THURSDAY. PRECIPITATION WITH THE FRONT WILL NOT BE TOO
SUBSTANTIAL.
THE FRONT STALLS SOUTHEAST OF THE REGION WITH COLDER AIR SETTLING
INTO THE FORECAST AREA. DISTURBANCES IN THE SOUTHERN STREAM WILL
MOVE THROUGH SOUTHWEST FLOW ALOFT. THIS WILL RESULT IN
PRECIPITATION SPREADING WELL NORTH OF THE FRONT BACK ACROSS THE
AREA. THIS COULD COME IN A FEW WAVES FROM LATE THURSDAY INTO
FRIDAY NIGHT. THERE WILL BE A TRANSITION IN PRECIPITATION TYPE
WHICH MAY OSCILLATE ACROSS THE REGION. THERE WILL LIKELY BE
ACCUMULATING SNOW...BUT WITH SO MANY UNCERTAIN VARIABLES AT THIS
POINT IN TIME...LOCATION AND AMOUNT ARE QUITE UNCLEAR.
EXPECT PRECIPITATION TO FINALLY PUSH OFF TO THE SOUTHEAST FRIDAY
NIGHT AS MODIFIED ARCTIC HIGH PRESSURE FINALLY BUILDS IN.
TEMPERATURES WILL BE WELL BELOW NORMAL OVER THE WEEKEND. THERE IS
SOME POTENTIAL FOR ANOTHER WAVE OF WINTRY PRECIPITATION TO SPREAD
BACK IN FROM THE SOUTH ON SUNDAY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AC DECK CONTINUES TO WORK INTO THE REGION AND OVERRUN A LINGERING
SC DECK. LATEST RUNS OF THE RAP AND NAM ARE BOTH INDICATING THAT
ANY SC THAT LINGER ACROSS THE REGION WILL REMAIN VFR.
MEANWHILE...SOME MVFR FOG WILL BE POSSIBLE ACROSS THE NRN TAFS
THRU SUNRISE.
SC AND AC DECKS WILL LINGER ACROSS THE TAFS ON MONDAY...BUT SHOULD
BE VFR. THEN AS A S/W APPROACHES THE REGION AFT 00Z TUESDAY...THE
STALLED FNT ACROSS THE REGION WILL BEGIN TO LIFT N AS A WARM
FRONT. COULD SEE SOME MVFR CIGS AND A FEW SHRA AS THIS FEATURE
LIFTS N.
OUTLOOK...SOME MVFR CEILINGS POSSIBLE THROUGH TUESDAY MORNING. MVFR
CEILINGS AND VISIBILITIES POSSIBLE AGAIN WEDNESDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
947 AM CST MON DEC 2 2013
.UPDATE...
WEAK SHORTWAVE PULLING ACROSS THE DEEP SOUTH THIS HOUR.
THUS...SHOWER ACTIVITY REMAIN SOUTH OF MIDDLE TN BUT CLOUDINESS
SHOULD REMAIN IN PLACE THROUGH THE DAY. DYNAMICS FOR THE REMAINDER
OF THE DAY ARE DIFFICULT TO COME BY. CURRENT FCST DOES CARRY A
CHANCE OF SPRINKLES NORTH AND A SLIGHT CHANCE OF SHOWERS SOUTH.
ISENTROPIC ANALYSIS SHOWS A DECREASE IN CONDENSATION DEFICITS
THROUGH THE DAY IN THE LOWER LEVELS. FURTHERMORE...ISENTROPIC
UPGLIDE IN THE LOWER LEVELS SHOULD CONTINUE. LATEST HRRR INFO DOES
INDICATE SOME LIGHT REFLECTIVITY RETURN LATER TODAY.
THEREFORE...WILL OPT TO CONTINUE WITH THE CURRENT WEATHER GRIDS.
OTW...ONLY OTHER CHANGE WILL BE TO RAISE HIGH TEMPS A DEGREE OR
SO. 18Z GRAPHICAL PROGS SUGGEST THAT TEMPS WILL BE NEARING THE MID
50S FOR MANY AREAS WEST OF THE PLATEAU BY 18Z OR 19Z.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 528 AM CST MON DEC 2 2013/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...LOW LEVEL MOISTURE WILL PERSIST...KEEPING MVFR CIGS
ACROSS THE AREA THROUGH THIS PERIOD. ANY -RA WILL BE SCT AND VERY
LIGHT...SO NOT INCLUDING ANY IN TAFS. WINDS WILL BE LIGHT FROM THE
SOUTH THROUGH THE NEXT 24 HOURS.
13
PREV DISCUSSION... /ISSUED 358 AM CST MON DEC 2 2013/
SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
EARLY THIS MONDAY MORNING...SKIES WERE OVERCAST WITH MILD TEMPERATURES
FOR DECEMBER...IN THE 40S. SCATTERED LIGHT SHOWERS WERE MOVING
ACROSS THE FAR SOUTHERN COUNTIES OF MID TN.
TODAY WILL BE MUCH LIKE YESTERDAY...WITH PERSISTENT CLOUDS AND HIGHS
IN THE 50S. THE MAIN SHORTWAVE TROUGH PRODUCING THE SOUTHERN SHOWERS
WILL MOVE EAST...BUT SOME WEAK TROUGHING AND LIFT WILL PERSIST...SO
WE WILL KEEP 20 POPS TODAY. ANY RAINFALL WILL MEASURE LESS THAN ONE
TENTH OF AN INCH.
FOR TONIGHT AND TUESDAY...BOUNDARY LAYER MOISTURE WILL REMAIN
HIGH...BUT NO SIGNIFICANT LIFT IS NOTED...SO CLOUDY SKIES WILL
PRODUCE JUST A FEW SPRINKLES. SOUTHERLY LOW LEVEL WINDS COMBINED
WITH SLIGHTLY BACKING UPPER LEVEL FLOW WILL BRING MILD
TEMPERATURES...CLIMBING INTO THE 60S ON TUESDAY.
FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THERE ARE SOME MODEL
DIFFERENCES. THE GFS AND NAM EJECT A FAIRLY STRONG SHORTWAVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES WHICH PUSHES A COLD FRONT INTO
OUR AREA ON WEDNESDAY. A FEW GEFS MEMBERS AND THE MORE CONSISTENT
ECMWF SHOW A MUCH WEAKER OR FARTHER WEST SYSTEM...WHICH WOULD HOLD
THE FRONT BACK 24 HOURS SLOWER THAN THE GFS. WE LIKE THIS SOLUTION
BETTER...AND WPC SUPPORTS THE ECMWF ENSEMBLE BLEND. THIS TIMING WILL
MAKE A HUGE DIFFERENCE FOR TEMPERATURES IN THE WEDNESDAY THROUGH
THURSDAY PERIODS. BASED ON THE SLOWER FRONT...WE WILL FORECAST VERY
MILD TEMPERATURES MIDWEEK. HIGHS WEDNESDAY WILL CLIMB WELL INTO THE
60S WITH GUSTY SOUTH WINDS. 70+ WILL BE ACHIEVABLE IF CLOUDS BREAK
UP ENOUGH. LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT WILL BE MANLY IN
THE 50S...BUT THE INCOMING COLD FRONT MAY DROP OUR NORTHWEST COUNTIES
QUICKLY DOWN INTO THE 40S LATE WEDNESDAY NIGHT. THE CHANCE FOR
SHOWERS WILL INCREASE AS THE COLD FRONT APPROACHES.
13
LONG TERM...(THURSDAY THROUGH SUNDAY)
A MESSY PATTERN WITH POTENTIALLY SIGNIFICANT RAINFALL AND WINTER
WX IS EXPECTED. CONTINUED MOIST SOUTHWEST FLOW ALOFT WILL INTERACT
WITH AN ARCTIC INTRUSION. TEMPERATURES WILL BE NEARLY STEADY OR
FALL THURSDAY AS THE COLD FRONT MOVES ACROSS THE MID STATE WITH
WIDESPREAD RAIN. THE RAIN WILL CONTINUE AS DEEP MOISTURE STREAMS
ACROSS THE SLOW MOVING FRONTAL ZONE THURSDAY NIGHT AND FRIDAY.
RAINFALL TOTALS OF 2 TO 4 INCHES ARE EXPECTED. THE COLD AIR WILL
BE GRADUALLY BUILDING FROM THE NORTHWEST...WITH ENOUGH COLD AIR
DEPTH TO PRODUCE SOME MIXED WINTRY PRECIPITATION OVER OUR
NORTHWEST COUNTIES LATE THURSDAY NIGHT AND FRIDAY.
MODELS ARE IN GOOD AGREEMENT WITH A TRANSITION TO WINTRY
PRECIPITATION ACROSS THE AREA FRIDAY NIGHT...WITH THE
PRECIPITATION COMING TO AN END SATURDAY MORNING. RAIN IS EXPECTED
TO TRANSITION TO SLEET AND SNOW...THEN TAPER OFF WITH A BRIEF
PERIOD OF FREEZING DRIZZLE POSSIBLE SATURDAY MORNING. HAZARDOUS
TRAVEL CONDITIONS ARE A GOOD BET DURING THIS TIME PERIOD WITH
TEMPERATURES FALLING INTO THE 20S FRIDAY NIGHT.
WE WILL HAVE DRY WX BY SATURDAY AFTERNOON WITH VERY COLD AND DRY
AIR. OUR TEMPERATURE FORECAST WILL UNDERCUT GFS MOS SUBSTANTIALLY
FOR SATURDAY...AND THROUGH THE ENTIRE WEEKEND BASED ON THE
STRENGTH OF THE COLD DENSE ARCTIC AIR MASS. ANOTHER WAVE AND SURGE
OF MOISTURE WILL BRING ANOTHER SHOT OF WINTRY WX SATURDAY
NIGHT...MOST LIKELY IN THE FORM OF A SNOW AND SLEET MIXTURE. THIS
MIX WILL GRADUALLY TRANSITION TO SLEET...FREEZING RAIN...AND
EVENTUALLY TO ALL RAIN BY MONDAY AS A STRONG WARM NOSE ALOFT
DEVELOPS FROM SOUTHEAST TO NORTHWEST. BEFORE THIS TRANSITION IS
COMPLETE...SOME SIGNIFICANT ICE PROBLEMS WILL BE
POSSIBLE...ESPECIALLY OVER THE NORTHWEST HALF OF THE MID STATE.
19/13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS DES MOINES IA
426 PM CST MON DEC 2 2013
.SHORT TERM /TONIGHT/...
ISSUED AT 424 PM CST MON DEC 2 2013
SKIES ARE CLEARING RAPIDLY FROM WEST TO EAST THIS AFTERNOON...BUT
SOME HIGH CLOUDS ARE FILLING BACK IN FROM THE NORTHWEST PER
SATELLITE IMAGERY. AS EXPECTED A WARM FRONT HAS NOSED INTO OUR SOUTH
AND SOUTHWEST AND CONTINUES TO ADVANCE TOWARD CENTRAL
IOWA...BRINGING TEMPERATURES IN THE 50S WITH IT. A QUIET NIGHT IS IN
STORE AS WINDS REMAIN GENERALLY FROM THE SOUTHEAST BUT MID/HIGH
CLOUDS STEADILY THICKEN AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.
THIS WILL RESULT IN TEMPERATURES STAYING RELATIVELY WARM IN THE MID
TO UPPER 30S IN MOST AREAS OVERNIGHT. FORECAST SOUNDINGS ALSO
INDICATE THAT BY SUNRISE TUESDAY THERE WILL BE QUITE A DEEP
SATURATED LAYER ASSOCIATED WITH THE MID/HIGH CLOUDS...HOWEVER A
POWERFUL NEAR SURFACE DRY LAYER WILL REMAIN IN PLACE. THIS SHOULD
RESULT IN A SCENARIO SIMILAR TO THIS MORNING WHEREBY ANY PRECIP THAT
FORMS LATE TONIGHT WILL FALL IN THE FORM OF VIRGA EVAPORATING BEFORE
IT HITS THE SURFACE...THEN DURING THE DAY TUESDAY PRECIP WILL BE
MORE LIKELY TO REACH THE GROUND AT TIMES. THUS HAVE REMOVED POPS
OVERNIGHT...ALTHOUGH SPRINKLE WORDING MAY NEED TO BE INTRODUCED
LATER FOR THE PRE DAWN HOURS.
.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 424 PM CST MON DEC 2 2013
MAJOR CHALLENGE IN NEAR TERM IS TRACK OF LOW AND LOCATION/TIMING OF
ASSOCIATED FROPA. THE RAP HAS BEEN INITIALIZING THE BEST ALL
MORNING. BY TUESDAY AFTERNOON...GFS A LITTLE FASTER THAN RAP...AND
NAM A LITTLE SLOWER AND FURTHER SOUTH. ECMWF SEEMS TO SOMEWHAT OF AN
OUTLIER ON TRACK OF LOW. IT SEEMS THE NAM HAS THE BEST HANDLE ON THE
SITUATION...SO PUSHING BACK TIME OF COLD FROPA AND HAVE SUBSEQUENTLY
INCREASED TEMPS OVER GUIDANCE AND PVS FORECAST. ADDITIONALLY...THERE
COULD BE SOME SUNSHINE IN SOUTHWESTERN IOWA AS DRIER AIR BEING
ADCEVTED INTO LOWER LEVELS...WHICH COULD ACTUALLY HELP TEMPS WARM UP
INTO THE MID 60S. DECENT MOISTURE CONVERGENCE AND FORCING ALONG COLD
FRONT. HOWEVER...SOUNDING PROFILES NOT VERY SATURATED IN DMX CWA SO
PRECIP MAY STRUGGLE TO REACH GROUND...THUS LOW QPF FORECAST. STRONG
CAA AND TEMP GRADIENT BEHIND FRONT...SO PRECIP TYPE WILL BE TOUGH TO
PIN DOWN. THE TRANSITION ZONE FROM RANI TO SNOW WILL BE VERY NARROW.
BETTER FORCING TOWARDS MINNESOTA...SO HIGHER POPS TO THE NORTH.
FOR THURSDAY...GFS SOUNDINGS NOW KEEP THE PROFILE VERY SATURATED
DURING THE MORNING. A FEW FLURRIES MAY FALL DURING THE MORNING...BUT
NOT A LOT OF SUPPORT IN THE ATMOSPHERE FOR ANYTHING THAT WOULD
NOTABLY IMPACT THE PUBLIC. ALL MODELS HAVE SUBSIDENCE AND DRY
NORTHWESTERLY FLOW BEING ADVECTED DOWN TO CWA...ESPECIALLY THE
NAM...DURING THE AFTERNOON. THERFORE...THINK CLOUDS SHOULD BEGIN TO
BREAK UP DURING THE DAY. DUE TO LACK OF FORCING HAVE REDUCED POPS
FOR THURSDAY PM.
THURSDAY/S TEMPERATURES SLIGHTLY TRICKY. AS MENTIONED ABOVE...CLOUDS
COVER LIKELY TO BE PRESENT DURING THE MORNING BUT WILL BREAK UP
DURING THE AFTERNOON. ADDITIONALLY...IT APPEARS WIND SPEEDS WILL
REMAIN NEAR THE 10 TO 15KT RANGE. CAA THROUGHOUT THE DAY AS H850
TEMPS WILL START THE DAY AROUND -10C AND END THE DAY NEAR -13C.
THERFORE WENT SEVERAL DEGREES ABOVE GUIDANCE FOR THURSDAY
MORNING...AND WILL INCREASE DAYTIME TEMPERATURES A FEW DEGREES WITH
THE ANTICIPATED SUNSHINE. IN LOCATIONS WHERE SUN CANNOT MAKE IT
THROUGH...TEMPS WILL LIKELY HOLD STEADY OR DECREASE DURING THE DAY.
BY FRIDAY MORNING...PRESSURE GRADIENT STILL PRETTY TIGHT IN ADVANCE
OF APPROACHING HIGH SO WINDS WILL STAY AT LEAST AROUND 10 KTS.
THOUGH NOT A PURE RADIATIONAL COOLING NIGHT...WITH H850 TEMPS
APPROACHING -17C...APPARENT TEMPERATURE AT SURFACE WILL APPROACH
ZERO DEGREES...AND MAY EVEN BE BELOW ZERO IN SOME LOCATIONS. SUNNY
SKIES WILL PREVAIL FOR THE AFTERNOON...BUT HIGHS WILL STRUGGLE TO
MAKE IT OUT OF THE TEENS AS NO WAA EXPECTED.
FOR THE WEEKEND...GFS AND EURO CAME INTO SLIGHTLY BETTER AGREEMENT
WITH THEIR 12Z RUNS. HOWEVER...THERE IS STILL QUITE A BIT OF
DISAGREEMENT. BOTH MODELS DEVELOP A SIZABLE TROUGH THAT PUSHES OFF
THE ROCKIES. THE EURO HAS A MUCH MORE SOUTHERLY TRACK...PUTTING THE
REGION INTO SOUTHWESTERLY FLOW AND BRINGING MUCH GREATER CHANCE FOR
WINTRY PRECIP TO THE AREA. THE GFS ENSEMBLES KEEP THE LOW FURTHER
NORTH...KEPING THE CWA IN WESTERLY TO NORTHWESTERLY FLOW...WHICH
WOULD KEEP COOL...DRY AIR ALOFT AND REDUCE PRECIPITATION CHANCES
FOR DMX.
&&
.AVIATION...02/18Z
ISSUED AT 1126 AM CST MON DEC 2 2013
HIGH CEILINGS...LIGHT RAIN...AND HAZE SHOULD CLEAR OUT FROM WEST
TO EAST IN THE NEXT FEW HOURS WITH VFR CONDITIONS PREVAILING
THEREAFTER. OVERNIGHT...MID/HIGH CLOUDS BETWEEN FL070-FL120 WILL
INCREASE ONCE AGAIN AND BR WILL REDEVELOP ESPECIALLY DURING THE
MORNING HOURS TUES. EXPECT MVFR VSBYS FOR THE MOST PART AND MAYBE
A FEW LOW CLOUDS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LEE
LONG TERM...KOTENBERG
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1112 AM CST MON DEC 2 2013
.UPDATE...
ISSUED AT 1105 AM CST MON DEC 2 2013
A SHORT WAVE MOVING INTO THE AREA COMBINED WITH A WARM FRONT THAT
EXTENDED FROM EASTERN NEB TO CENTRAL MO WAS PRODUCING AN AREA OF
VIRGA/SPRINKLES ACROSS THE DVN CWA. LOW LEVELS OF THE ATMOSPHERE
ARE STILL DRY BUT AS BETTER FORCING ARRIVES THIS AFTERNOON THE LOW
LEVELS SHOULD SATURATE. THE RAPID REFRESH MODEL DEPICTS A BAND OF
LIGHT RAIN MOVING ACROSS THE CWA THIS AFTERNOON INTO THE EVENING.
RAIN AMOUNTS SHOULD BE ONLY A TRACE TO A FEW HUNDREDTHS OF AN INCH.
CURRENT TEMPERATURES RANGE FROM THE MID 30S TO LOWER 40S AND
TEMPERATURES SHOULD RISE ONLY A FEW MORE DEGREES DUE TO EXTENSIVE
CLOUD COVER. HOWEVER...OUR SOUTHERN CWA SHOULD HAVE MORE SUNSHINE
LATER THIS AFTERNOON AS THE WARM FRONT NEARS THAT AREA ALLOWING
TEMPERATURES TO PUSH TO AROUND 50.
UPDATE ISSUED AT 735 AM CST MON DEC 2 2013
MID LEVEL CLOUDS ARE DEVELOPING ACROSS IOWA AND RADAR REFLECTS
THIS WITH AN INCREASE IN OVERALL RETURNS. 12Z DVN SOUNDING HAS A
DRY LAYER FROM ROUGHLY 950-850MB WITH SATURATION OCCURRING ABOVE
THAT. THIS DRY LAYER IS NARROWER THAN WHAT ANY OF THE MODELS
INDICATED IN THEIR RESPECTIVE 6 AND 12 HR FORECASTS.
RECENT TRENDS IN THE RAP MODEL GENERALLY SUPPORTS THE CURRENT
FORECAST OF A BAND OF RAIN DEVELOPING AND MOVING ACROSS THE AREA
TODAY. THE ONLY DIFFERENCE IS THAT THE DEVELOPMENT MAY OCCUR A BIT
LATER THAN WHAT THE CURRENT FORECAST HAS. HOWEVER...THE NARROWER
DRY LAYER IN THE MORNING SOUNDING WOULD TAKE LESS TIME TO
SATURATE SO PRECIPITATION MAY START SOONER THAN WHAT THE RAP IS
SUGGESTING.
&&
.SYNOPSIS...
ISSUED AT 316 AM CST MON DEC 2 2013
06Z SFC ANALYSIS HAS WEAK LOWS NEAR KVIH...KRSL...AND KPIR.
DEVELOPING WARM FRONTS RAN ACROSS NORTHEAST KANSAS THROUGH CENTRAL
MISSOURI AND ANOTHER FROM THE DAKOTAS INTO EASTERN NEBRASKA. DEW
POINTS WERE IN THE 20S ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST
WITHS 30S AND HIGHER FROM THE OHIO VALLEY INTO THE DEEP SOUTH AND
SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM CST MON DEC 2 2013
CURRENT RADAR TRENDS SHOW PRECIPITATION DECREASING IN COVERAGE AS
THE FIRST ROUND OF FORCING WEAKENS. THUS MAINLY DRY CONDITIONS
SHOULD BE SEEN THROUGH SUNRISE AND THE FIRST PART OF THE MORNING.
FROM MID TO LATE MORNING FORCING BEGINS TO INCREASE AGAIN WITH THE
APPROACH OF THE NEXT UPPER LEVEL DISTURBANCE. THERE IS REASONABLE
AGREEMENT AMONG THE MODELS THAT AS THE FORCING INCREASES...VERY
LIGHT RAIN SHOULD BREAK OUT FROM CENTRAL IOWA INTO THE WESTERN PARTS
OF THE AREA AND INCREASE IN COVERAGE THROUGH MID DAY.
MOISTURE AVAILABILITY IS LIMITED BUT THE FORCING INCREASES FURTHER
DURING THE AFTERNOON. SO...THERE SHOULD BE A BAND OF LIGHT RAIN THAT
WILL MOVE ACROSS THE AREA FROM LATE MORNING THROUGH THE AFTERNOON.
AS THE UPPER LEVEL DISTURBANCE EXITS THE AREA THIS EVENING THE AREAL
COVERAGE OF THE LIGHT RAIN WILL DECREASE THROUGH MID EVENING. THERE
MAY BE A LULL IN PRECIPITATION FROM MID EVENING THROUGH EARLY
MORNING BEFORE THE NEXT UPPER LEVEL DISTURBANCE ARRIVES. THIS
DISTURBANCE SHOULD EITHER ALLOW A MIX TO PERSIST ACROSS THE NORTH OR
DEVELOP A MIX PRIOR TO SUNRISE ON TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 316 AM CST MON DEC 2 2013
A STRONG ARCTIC FRONT WILL SWEEP THROUGH THE MIDWEST...BRINGING A
RETURN TO BRISK COLD TEMPERATURE FOR THE REMAINDER OF THE WEEK.
WHEN THIS BEGINS...THE FROPA...REMAINS A GIANT TROUBLESOME
DIFFERENCE IN THE 00Z GUIDANCE SUITE. THE PERIOD THIS DIFFERENCE WILL
AFFECT IS WEDNESDAY. THERE ARE TWO CAMPS...THE FASTER
NAM/GFS...WHICH MOVE THE FRONT INTO THE CWA TUESDAY NIGHT...AND THE
FAR SLOWER UKMET AND ECMWF WHICH MOVE THE FRONT THROUGH THE CWA
WEDNESDAY AFTERNOON. THIS ROUGHLY 12 HOUR DIFFERENCE CREATES
POTENTIAL FOR A 20 DEGREE BUST ON TEMPS FOR WEDNESDAY. WE COULD
CONCEIVABLY BEGIN THE DAY IN THE MID 30S TO MID 40S...AND FALL LIKE
A ROCK ALL DAY...OR SHOULD THE SLOWER SOLUTIONS WORK OUT...AN
AFTERNOON HIGHS WELL INTO THE 50S COULD BE SEEN IN ILLINOIS. GIVEN
THE POSITIVELY TILTED UPPER TROF...I STILL FEEL THE FASTER SOLUTIONS
ARE NOT OUT OF THE QUESTION. THUS...I WILL GO A BIT MILDER WEDNESDAY
THAN THE FAST/COLD NAM...BUT MUCH COOLER THAN THE SLOW ECMWF. IN
ALL...THIS DAY STILL DOES NOT OFFER MUCH CHANCE FOR SIGNIFICANT
RAIN/SNOW...BUT A SMALL POP FOR 0.01 OR SO REMAINS IN THE FORECAST
WITH THE FRONT.
TEMPERATURES TUESDAY WILL BE QUITE MILD...WARM SECTORED...WITH 40S
NORTH TO MID AND UPPER 50S CENTRAL AND SOUTH. THIS AIR HANGS ON
UNTIL THE FROPA...LEADING TO THE POTENTIAL CHALLENGE OF WEDNESDAYS
HIGHS AND HOURLY TEMPERATURES. BEHIND THE FRONT...TEMPERATURES WILL
CERTAINLY CRASH...TO THE 20S AND TEENS INITIALLY...BUT BY THURSDAY
NIGHT THROUGH THE WEEKEND...LOWS IN THE SINGLE DIGITS ARE CERTAINLY
LIKELY. HIGHS IN THE UPPER TEENS TO LOWER 20S WILL FINISH OUT THE
WEEK. WIND CHILLS OF -10 TO +5 WILL BE FOUND EACH NIGHT FROM
THURSDAY NIGHT THROUGH SATURDAY NIGHT.
LOW POPS ARE RETAINED IN THE SOUTH FOR THE NORTH EDGE OF A POSSIBLE
OVER RUNNING LIGHT SNOW EVENT THURSDAY INTO FRIDAY. OTHERWISE...THE
NEXT MORE LIKELY OVER RUNNING LIGHT SNOW EVENT APPEARS SET FOR
SUNDAY AND MONDAY.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1105 AM CST MON DEC 2 2013
VFR/OCNL MVFR CONDS IN BR/AREAS OF -RA THROUGH THIS EVENING. THEN
MVFR/OCNL IFR CIGS/VIS TONIGHT INTO TUESDAY MORNING. SOUTHEAST
WINDS AROUND 10 KNOTS OR LESS THROUGH THIS TAF CYCLE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...08
SHORT TERM...08
LONG TERM...ERVIN
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 PM EST MON DEC 2 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 506 PM EST MON DEC 2 2013
MAIN FCST CONCERN IN THE SHORT TERM IS SNOW ACCUMULATIONS WITH A
RATHER PERSISTENT -SN REGIME SETTING UP.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW RELATIVELY ZONAL FLOW
ACROSS THE NRN PLAINS AND UPPER GREAT LAKES. ONE SHORTWAVE HAS MOVED
E OF UPPER MI...ANOTHER IS OVER THE ERN DAKOTAS/WRN MN WHILE A
WELL-DEFINED MID LEVEL LOW IS NOTED OVER THE PACIFIC NW. PCPN
TONIGHT/EARLY TUE WILL BE ASSOCIATED WITH THE SHORTWAVE HEADING INTO
MN...THEN ANOTHER ROUND OF FORCING MAY BEGIN TO OVERSPREAD THE AREA
LATER TUE AS PACIFIC NW SYSTEM EMERGES INTO THE NRN PLAINS.
RELATIVELY MODEST ISENTROPIC ASCENT/WAA REGIME AHEAD OF THE WRN MN
SHORTWAVE IS GENERATING AN AREA OF -SN FROM NE MN ACROSS FAR WRN
UPPER MI INTO NW WI. ANOTHER BAND OF SNOW IS LINED UP JUST AHEAD OF
THE SHORTWAVE TROF AXIS. AS SHORTWAVE AND ASSOCIATED ISENTROPIC
ASCENT SHIFT E...EXPECT -SN TO SPREAD GRADUALLY E ACROSS ROUGHLY THE
W HALF OF UPPER MI TONIGHT. BETTER ASCENT GENERALLY OCCURS OVER FAR
W INTO SRN UPPER MI...BUT TENDS TO WEAKEN WITH TIME...ESPECIALLY
FARTHER E AND NE...AS SHORTWAVE WEAKENS. MAY END UP WITH A PERIOD OF
STEADIER -SN OVER THE FAR W THIS EVENING UNDER WAA REGIME AND THEN
THERE WILL BE ANOTHER PUSH OF STEADIER -SN AS BAND OF SNOW JUST
AHEAD OF SHORTWAVE TROF AXIS SWINGS INTO THE AREA. IN THE END...
GREATEST SNOW ACCUMULATIONS TONIGHT THRU TUE MORNING WILL OCCUR OVER
THE FAR W AND TO SOME EXTENT TOWARD SCNTRL UPPER MI. UTILIZATION OF
MIXING RATIOS ON THE 290K SFC (ROUGHLY BTWN 700-750MB) SUGGESTS
POTENTIAL FOR 4-6 INCH ACCUMULATIONS ACROSS THE W AND SCNTRL TONIGHT
THRU TUE MORNING. HOWEVER...WITH A LACK OF FOCUSED UPWARD MOTION
THRU A RELATIVELY HIGH/NARROW DGZ...SNOW RATIOS WILL BE ON THE LOW
SIDE...PROBABLY SOMETHING LIKE 10-12 TO 1. ALSO...SINCE ISENTROPIC
ASCENT IS NEVER ESPECIALLY STRONG...SNOW ACCUMULATIONS WILL LIKELY
END UP BLO ADVY CRITERIA. ONLY PLACE THAT WILL BE CLOSE TO ADVY IS
IN THE KIWD VCNTY. FOR NOW...WILL HOLD OFF ANY HEADLINES AND MONITOR
TRENDS THIS EVENING. OVERALL TONIGHT/TUE MORNING...EXPECT MORE OF A
PERSISTENT -SN WITH NOT MUCH IN THE WAY OF NOTABLY HEAVIER PERIODS
OF SNOW.
ON TUE...AREA OF DIMINISHING -SN ASSOCIATED WITH WEAKENING SHORTWAVE
WILL CONTINUE TO LIFT N AND E. MEANWHILE...SYSTEM CURRENTLY OVER THE
PACIFIC NW WILL EMERGE OVER THE NRN PLAINS. AS IT DOES SO...
ISENTROPIC ASCENT MAY STRENGTHEN AGAIN IN THE AFTN OR INTO TUE
EVENING...THOUGH THERE IS SOME DISAGREEMENT ON HOW STRONG THE
ISENTROPIC ASCENT WILL BE. SO...AFTER DIMINISHING -SN INTO THE AFTN
HRS...-SN MAY PICK UP AGAIN FROM THE SW LATER IN THE AFTN. MAY SEE
AN INCH OR SO OF SNOW LATE IN THE DAY TOWARD THE WI BORDER.
SPECIAL WEATHER STATEMENT HAS BEEN UPDATED TO REFLECT THE LATEST
THINKING ON THE WINTRY WEATHER EXPECTED OVER THE NEXT FEW DAYS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 513 PM EST MON DEC 2 2013
SIGNIFICANT SNOWFALL IS POSSIBLE TUESDAY NIGHT INTO THURSDAY MORNING
FOR WEST AND CENTRAL UPPER MICHIGAN
AND THE SAGA CONTINUES...MODELS DISAGREEING ON HOW AND WHEN THE LOW
PRESSURE SYSTEM WILL CROSS UPPER MI. THOUGH ALL HAVE SIMILAR TRACKS
WITH SLIGHT DIFFERENCES...THE 12Z GFS/NAM AND THE 12Z GEM/12Z ECMWF
ARE WIDELY DIFFERENT IN TERMS OF TIMING.
ON THE TRACK OVERALL...MODELS TAKE THE LOW FROM THE CENTRAL PLAINS
INTO THE JAMES BAY/NORTHERN ONTARIO REGION. THE 12Z GEM/12Z
UKMET/12Z ECMWF TAKE THE LOW FURTHEST SOUTHEAST...MOVING FROM
SOUTHEASTERN WI TO EASTERN UPPER MI...THEN INTO ONTARIO SOUTH OF
JAMES BAY. THE GFS/NAM TAKE THE LOW TRACK FROM WESTERN WI INTO
CENTRAL UPPER MI...THEN JUST SOUTH OF JAMES BAY AND NORTHEAST OF
LAKE SUPERIOR.
TIMING WISE...THE 12 GFS/NAM HAVE A MUCH QUICKER SOLUTION THAN THE
ECMWF/GEM...AND THE UKMET IS SLIGHTLY SLOWER THAN ALL. FOR
EXAMPLE...WHEN THE GFS/NAM HAVE THE LOW SOUTH OF JAMES BAY...THE 12Z
ECMWF/12Z GEM ARE JUST CROSSING IT OVER LAKE SUPERIOR/EASTERN UPPER
MI. THE UKMET HAS IT OVER SOUTHEASTERN UPPER MI/NORTHERN LAKE MI.
OVERALL...SINCE CONSISTENCY WISE THE ECWMF SEEMS STEADIER...AND
BECAUSE OFTEN TIMES THE GFS SEEMS TO RUSH THINGS THROUGH/AMPLIFY
THINGS...OPTED TO LEAN TOWARDS THE SLOWER GEM/ECMWF SOLUTION FOR
TIMING. FOR THE EXACT TRACK OF THE LOW...USED A 12Z GEM/12Z ECMWF
COMPROMISE.
USING THE CHOSEN MODEL TRACKS/TIMING...A BROAD AREA OF 850MB WAA AND
ISENTROPIC ASCENT ON THE 290K SFC WILL BRING WIDESPREAD
PRECIPITATION ACROSS UPPER MICHIGAN AS THE SYSTEM APPROACHES TUESDAY
NIGHT THROUGH WEDNESDAY MORNING. SOUNDINGS SUGGEST THIS FIRST BURST
OF PRECIPITATION WILL BE IN THE FORM OF SNOW. BY WEDNESDAY
AFTERNOON...AS THE LOW REACHES IOWA AND ILLINOIS/SOUTHERN WI...WARM
MOIST AIR WRAPPING AROUND THE SURFACE LOW DEVELOPS A 700MB FGEN BAND
THAT ALIGNS ITSELF SOUTHWEST TO NORTHEAST...FROM SOUTHEASTERN MN TO
JUST NORTHEAST OF LAKE SUPERIOR...ACROSS THE WESTERN AND CENTRAL CWA.
BY 00Z THURSDAY SLIGHT DIFFERENCES IN THE TRACK OF THE LOW BETWEEN
THE GEM/ECMWF START TO AFFECT THE TEMPERATURE/PTYPE FORECAST. THE
12Z ECMWF CENTERS THE LOW OVER CENTRAL WI...WHICH BRINGS A NOSE OF
WARMER AIR SLIGHTLY FURTHER NORTH AND CENTRAL. THIS WOULD BRING
CHANCES FOR MIXED PRECIPITATION/RAIN INTO THE NORTH CENTRAL AND
EAST. THE GEM KEEPS THE LOW SOUTHEAST...CENTERED OVER SOUTHEASTERN
WI BY 00Z THUR AND NOT QUITE PULLING THAT WARMER AIR AROUND INTO THE
CENTRAL. THIS WOULD KEEP THE WEST AND NORTH CENTRAL ALL SNOW...AND
THE EAST A MIX/RAIN. BY 12Z THURSDAY HOWEVER...THE MODELS ALL AGREE
ON SNOW BEING THE PTYPE. THE EXACT TRACK WILL AFFECT WHAT TYPE OF
SNOWFALL AMOUNTS WE SEE. AGAIN...WENT WITH AN ECMWF/GEM COMPROMISE
FOR TEMPS/PTYPE...WHICH KEEPS THE PRECIPITATION SNOW FOR A MAJORITY
OF THE FORECAST AREA...ONLY MIXING/RAIN ACROSS THE FAR SOUTHEASTERN
CWA. OVERALL...ACCUMULATIONS COULD BE OVER 6-8 INCHES ACROSS THE
WEST AND CENTRAL U.P. FROM TUESDAY NIGHT INTO THURSDAY MORNING.
AS THE LOW MOVES OFF INTO ONTARIO JUST NORTHEAST OF LAKE SUPERIOR
BETWEEN 06Z AND 12Z THURSDAY...UPPER MICHIGAN IS QUICKLY BROUGHT
INTO AN AREA OF STRONG CAA ON WEST TO NORTHWEST WINDS. 850MB TEMPS
QUICKLY DIP INTO THE -15 TO -20C RANGE IN THE WAKE OF THE LOW...AND
ON ON WEST TO NORTHWEST WINDS LAKE EFFECT CHANCES QUICKLY BECOME THE
MAIN CONCERN. GRADUALLY AS THE LOW HOVERS OVER JAMES BAY AREA FRIDAY
AND SATURDAY...850MB TEMPS CONTINUE TO DROP...REACHING AS LOW AS
-22C...WITH THE KEWEENAW AND WESTERN UPPER MI IN THE COLDEST OF THAT
AIR. THIS WILL BRING VERY COLD TEMPERATURES TO UPPER MICHIGAN FRIDAY
NIGHT THROUGH SATURDAY NIGHT...WITH WIND CHILLS AS LOW AS -25C IN
SOME PLACES OUT WEST.
SATURDAY AND SUNDAY...HIGH PRESSURE STEADILY EXPANDING FROM THE
CANADIAN PRAIRIE...ACROSS THE GREAT LAKES...AND INTO THE ATLANTIC.
GENERALLY IN THIS TIME FRAME...WINDS ARE WESTERLY TO
NORTHWESTERLY...850MB TEMPS RANGE FROM -22C TO -15C...AND THERE ARE
SHORTWAVES ROUNDING THE LOW OVER JAMES BAY. THESE SHORTWAVES WILL
SERVE TO ASSIST THE EXPECTED LAKE EFFECT SNOW SHOWERS DURING THESE
PERIODS...WITH CHANCES LESSENING AS THE LOW DEPARTS AND THE HIGH
STRENGTHENS. SNOW ACCUMULATIONS COULD BE HAMPERED HOWEVER...AS THE
DGZ DIPS CLOSER TO THE GROUND WITH THE EXTREME COLD. ON MONDAY
MODELS DISAGREE SLIGHTLY ON ANOTHER AREA OF LOW PRESSURE MOVING INTO
THE GREAT LAKES REGION...SO KEPT CONSENSUS PRECIPITATION CHANCES
BEGINNING ACROSS THE NON-LAKE EFFECT AREAS AS IT APPROACHES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON DEC 2 2013
DISTURBANCE APPROACHING FROM THE NRN PLAINS WILL SPREAD -SN FROM W
TO E ACROSS THE AREA THIS AFTN AND TONIGHT. PRIOR TO THE ARRIVAL OF
-SN...VFR CONDITIONS WILL PREVAIL...THOUGH DEVELOPING UPSLOPE
FLOW WILL PROBABABLY LEAD TO MFVR CIGS DEVELOPING AT KCMX/KSAW LATER
THIS AFTN/EARLY THIS EVENING...WELL BEFORE THE ONSET OF -SN AT THOSE
TERMINALS. SEVERAL HRS AFTER THE -SN BEGINS AT EACH TERMINAL...
CONDITIONS WILL DETERIORATE TO IFR. MAY SEE SOME IMPROVEMENT AT KIWD
TUE MORNING AS STEADIER -SN SHIFTS E AND NE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 PM EST MON DEC 2 2013
AS LOW PRES BEGINS TO ORGANIZE IN THE PLAINS AND HIGH PRES BUILDS
ACROSS CNTRL CANADA AND INTO NRN ONTARIO...E TO SE WINDS WILL BE ON
THE INCREASE TONIGHT...AND E WINDS WILL INCREASE FURTHER TUE. EXPECT
WINDS TO REACH GALE FORCE OVER WRN LAKE SUPERIOR TUE AFTN THU WED
MORNING AS TERRAIN SURROUNDING THE LAKE ENHANCES THE E FLOW. THE LOW
WILL MOVE ACROSS THE UPPER GREAT LAKES LATE WED. IN THE WAKE OF THE
LOW...VERY COLD AIR ADVECTING OVER THE RELATIVELY WARM WATERS WILL
INCREASE INSTABILITY AND RESULT IN W TO NW GALES AT TIMES FOR
PORTIONS OF LAKE SUPERIOR WED NIGHT/THU. CONTINUED FLOW OF VERY COLD
AIR MAY RESULT IN PERIODIC GALES EVEN THRU FRI/SAT. BUILDING WAVES
AND THE ARRIVAL OF THE ARCTIC AIR WILL ALSO CAUSE INCREASING
FREEZING SPRAY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 PM EST /NOON CST/ TUESDAY TO 10 AM EST /9 AM
CST/ WEDNESDAY FOR LSZ162.
GALE WARNING FROM 4 PM TUESDAY TO 10 AM EST WEDNESDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 PM EST MON DEC 2 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 506 PM EST MON DEC 2 2013
MAIN FCST CONCERN IN THE SHORT TERM IS SNOW ACCUMULATIONS WITH A
RATHER PERSISTENT -SN REGIME SETTING UP.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW RELATIVELY ZONAL FLOW
ACROSS THE NRN PLAINS AND UPPER GREAT LAKES. ONE SHORTWAVE HAS MOVED
E OF UPPER MI...ANOTHER IS OVER THE ERN DAKOTAS/WRN MN WHILE A
WELL-DEFINED MID LEVEL LOW IS NOTED OVER THE PACIFIC NW. PCPN
TONIGHT/EARLY TUE WILL BE ASSOCIATED WITH THE SHORTWAVE HEADING INTO
MN...THEN ANOTHER ROUND OF FORCING MAY BEGIN TO OVERSPREAD THE AREA
LATER TUE AS PACIFIC NW SYSTEM EMERGES INTO THE NRN PLAINS.
RELATIVELY MODEST ISENTROPIC ASCENT/WAA REGIME AHEAD OF THE WRN MN
SHORTWAVE IS GENERATING AN AREA OF -SN FROM NE MN ACROSS FAR WRN
UPPER MI INTO NW WI. ANOTHER BAND OF SNOW IS LINED UP JUST AHEAD OF
THE SHORTWAVE TROF AXIS. AS SHORTWAVE AND ASSOCIATED ISENTROPIC
ASCENT SHIFT E...EXPECT -SN TO SPREAD GRADUALLY E ACROSS ROUGHLY THE
W HALF OF UPPER MI TONIGHT. BETTER ASCENT GENERALLY OCCURS OVER FAR
W INTO SRN UPPER MI...BUT TENDS TO WEAKEN WITH TIME...ESPECIALLY
FARTHER E AND NE...AS SHORTWAVE WEAKENS. MAY END UP WITH A PERIOD OF
STEADIER -SN OVER THE FAR W THIS EVENING UNDER WAA REGIME AND THEN
THERE WILL BE ANOTHER PUSH OF STEADIER -SN AS BAND OF SNOW JUST
AHEAD OF SHORTWAVE TROF AXIS SWINGS INTO THE AREA. IN THE END...
GREATEST SNOW ACCUMULATIONS TONIGHT THRU TUE MORNING WILL OCCUR OVER
THE FAR W AND TO SOME EXTENT TOWARD SCNTRL UPPER MI. UTILIZATION OF
MIXING RATIOS ON THE 290K SFC (ROUGHLY BTWN 700-750MB) SUGGESTS
POTENTIAL FOR 4-6 INCH ACCUMULATIONS ACROSS THE W AND SCNTRL TONIGHT
THRU TUE MORNING. HOWEVER...WITH A LACK OF FOCUSED UPWARD MOTION
THRU A RELATIVELY HIGH/NARROW DGZ...SNOW RATIOS WILL BE ON THE LOW
SIDE...PROBABLY SOMETHING LIKE 10-12 TO 1. ALSO...SINCE ISENTROPIC
ASCENT IS NEVER ESPECIALLY STRONG...SNOW ACCUMULATIONS WILL LIKELY
END UP BLO ADVY CRITERIA. ONLY PLACE THAT WILL BE CLOSE TO ADVY IS
IN THE KIWD VCNTY. FOR NOW...WILL HOLD OFF ANY HEADLINES AND MONITOR
TRENDS THIS EVENING. OVERALL TONIGHT/TUE MORNING...EXPECT MORE OF A
PERSISTENT -SN WITH NOT MUCH IN THE WAY OF NOTABLY HEAVIER PERIODS
OF SNOW.
ON TUE...AREA OF DIMINISHING -SN ASSOCIATED WITH WEAKENING SHORTWAVE
WILL CONTINUE TO LIFT N AND E. MEANWHILE...SYSTEM CURRENTLY OVER THE
PACIFIC NW WILL EMERGE OVER THE NRN PLAINS. AS IT DOES SO...
ISENTROPIC ASCENT MAY STRENGTHEN AGAIN IN THE AFTN OR INTO TUE
EVENING...THOUGH THERE IS SOME DISAGREEMENT ON HOW STRONG THE
ISENTROPIC ASCENT WILL BE. SO...AFTER DIMINISHING -SN INTO THE AFTN
HRS...-SN MAY PICK UP AGAIN FROM THE SW LATER IN THE AFTN. MAY SEE
AN INCH OR SO OF SNOW LATE IN THE DAY TOWARD THE WI BORDER.
SPECIAL WEATHER STATEMENT HAS BEEN UPDATED TO REFLECT THE LATEST
THINKING ON THE WINTRY WEATHER EXPECTED OVER THE NEXT FEW DAYS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON DEC 2 2013
DISTURBANCE APPROACHING FROM THE NRN PLAINS WILL SPREAD -SN FROM W
TO E ACROSS THE AREA THIS AFTN AND TONIGHT. PRIOR TO THE ARRIVAL OF
-SN...VFR CONDITIONS WILL PREVAIL...THOUGH DEVELOPING UPSLOPE
FLOW WILL PROBABABLY LEAD TO MFVR CIGS DEVELOPING AT KCMX/KSAW LATER
THIS AFTN/EARLY THIS EVENING...WELL BEFORE THE ONSET OF -SN AT THOSE
TERMINALS. SEVERAL HRS AFTER THE -SN BEGINS AT EACH TERMINAL...
CONDITIONS WILL DETERIORATE TO IFR. MAY SEE SOME IMPROVEMENT AT KIWD
TUE MORNING AS STEADIER -SN SHIFTS E AND NE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 PM EST MON DEC 2 2013
AS LOW PRES BEGINS TO ORGANIZE IN THE PLAINS AND HIGH PRES BUILDS
ACROSS CNTRL CANADA AND INTO NRN ONTARIO...E TO SE WINDS WILL BE ON
THE INCREASE TONIGHT...AND E WINDS WILL INCREASE FURTHER TUE. EXPECT
WINDS TO REACH GALE FORCE OVER WRN LAKE SUPERIOR TUE AFTN THU WED
MORNING AS TERRAIN SURROUNDING THE LAKE ENHANCES THE E FLOW. THE LOW
WILL MOVE ACROSS THE UPPER GREAT LAKES LATE WED. IN THE WAKE OF THE
LOW...VERY COLD AIR ADVECTING OVER THE RELATIVELY WARM WATERS WILL
INCREASE INSTABILITY AND RESULT IN W TO NW GALES AT TIMES FOR
PORTIONS OF LAKE SUPERIOR WED NIGHT/THU. CONTINUED FLOW OF VERY COLD
AIR MAY RESULT IN PERIODIC GALES EVEN THRU FRI/SAT. BUILDING WAVES
AND THE ARRIVAL OF THE ARCTIC AIR WILL ALSO CAUSE INCREASING
FREEZING SPRAY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 1 PM EST /NOON CST/ TUESDAY TO 10 AM EST /9 AM
CST/ WEDNESDAY FOR LSZ162.
GALE WARNING FROM 4 PM TUESDAY TO 10 AM EST WEDNESDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
AVIATION...ROLFSON
LONG TERM...KEC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GAYLORD MI
135 PM EST MON DEC 2 2013
.SYNOPSIS...
ISSUED AT 300 AM EST MON DEC 2 2013
WEAK HIGH PRESSURE OVER THE WESTERN GREAT LAKES REGION WILL KEEP OUR
WEATHER DRY BUT CLOUDY TODAY. PRECIPITATION CHANCES WILL INCREASE
TUESDAY AS A WARM FRONT LIFTS THROUGH MICHIGAN...WITH A MIX OF RAIN
AND SNOW EVENTUALLY CHANGING OVER TO ALL RAIN ON WEDNESDAY.
PRECIPITATION WILL CHANGE BACK OVER TO ALL SNOW WEDNESDAY NIGHT AS A
COLD FRONT BLASTS THROUGH THE REGION.
&&
.UPDATE...
ISSUED AT 134 PM EST MON DEC 2 2013
BATCH OF LIGHT FLURRIES/DRIZZLE...SEEMINGLY LAKE INDUCED...CONTINUES AT
THIS HOUR OVER THE TIP OF THE MITT COUNTIES. LAKE MESO-LOW ALSO
CONTINUES TO SPIN JUST OFF LEELANAU COUNTY. HAS CLEARED OUT FAIRLY
WELL OVER EASTERN UPPER MICHIGAN BUT QUITE A BIT OF LOWER CLOUD
COVER STILL DRAPED OVER NRN LOWER MICHIGAN. REST OF THE
AFTERNOON...WHAT YOU SEE IS WHAT YOU GET PRETTY MUCH. HAVE TWEAKED
SKY/WEATHER FORECASTS TO ADJUST FOR TRENDS.
UPDATE ISSUED AT 944 AM EST MON DEC 2 2013
BROAD HIGH PRESSURE IN PLACE ACROSS THE GREAT LAKES THIS MORNING.
GENERALLY QUIET...BUT THERE IS A SUBTLE SHORT WAVE TROUGH MOVING
THROUGH THE REGION THAT HAS BROUGHT ABOUT A SUBTLE BUMP UP IN
INVERSION HEIGHTS AND WEAK UPWARD FORCING. ENOUGH TO PRODUCE A
HYBRID BROAD AREA OF LAKE INDUCED/SYNOPTIC LIGHT PRECIP ACROSS
PARTS OF THE CWA. MAINLY FLURRIES AS INVERSION HEIGHTS ARE JUST UP
INTO THE -12C/-13C RANGE...ALTHOUGH THERE MIGHT BE SOME
INTERMINGLED -FZDZ AS WELL.
HAVE EXTENDED FLURRIES/LIGHT FREEZING DRIZZLE OUT THROUGH THE REST
OF THE MORNING. RUC13 DATA THEN SUGGESTS FORCING WILL FALL APART
BY EARLY AFTERNOON AND WE SHOULD SEE A DOWNWARD TREND TO THE
LIGHT/NUISANCE PRECIP. WILL SEE.
UPDATE ISSUED AT 619 AM EST MON DEC 2 2013
PATCHY FREEZING DRIZZLE HAS EXPANDED ACROSS THE STRAITS AND FAR
NRN LWR MICHIGAN EARLY THIS MORNING PER LATEST KAPX 88D BASE REF
LOOP. SURFACE OBS HAVE YET TO REPORT THIS PHENOMENA...BUT A COUPLE
OF EARLY MORNING SPOTTER REPORTS CONFIRM THAT SOME VERY LIGHT
PRECIP IS REACHING THE GROUND. HAVE SPREAD PATCHY FREEZING DRIZZLE
INTO THESE AREAS AND HAVE EXTENDED THE OCCURRENCE THRU 15Z AS
SHALLOW LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE SUBSIDENCE
INVERSION AND SOME VERY WEAK SHEAR CONTINUES AT THE TOP OF THE
MOIST LAYER. REST OF THE DAY WILL BE CLOUDY WITH TEMPS ONLY
WARMING INTO THE LOW TO MID 30S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM EST MON DEC 2 2013
KINDA "DIRTY" HIGH PRESSURE EXTENDING ACROSS THE NORTH WOODS AT THIS
EARLY HOUR...WITH PLENTY OF CLOUDS STUCK BELOW STRONG H8 SUBSIDENCE
INVERSION (PER LOCAL 00Z SOUNDING). STILL SOME WEAK LAKE PROCESSES
ONGOING IN MARGINALLY COLD ENOUGH ATMOSPHERE...WITH EVEN A WELL
EVIDENT LAKE-INDUCED MESO LOW SPINNING HARMLESSLY ACROSS NORTHERN
LAKE MICHIGAN. ENOUGH LIFT/LAKE MOISTURE CONTRIBUTION TO KICK OFF A FEW
FLURRIES FOR SOME...BUT THAT`S ABOUT IT. MID AND UPPER LEVEL PATTERN
JUST ABOUT AS NONDESCRIPT AS THE SURFACE FEATURES...WITH GENERALLY
LIGHT WEST TO NORTHWEST FLOW ALOFT...WITH MUCH STRONGER JET ENERGY
WELL TO OUR WEST (LEADING CORE OF 100+ KNOT UPPER JET PUNCHING INTO
THE NORTHERN ROCKIES). JUST NOT A WHOLE LOT OF CHANGE EXPECTED
THROUGH THIS EVENING...WITH WAA PROCESSES RAMPING UP TOWARD TUESDAY
MORNING WELL AHEAD OF ORGANIZING CENTRAL PLAINS LOW PRESSURE.
THUS...FORECAST CONCERNS REMAIN RATHER TRIVIAL...CENTERING ON
CLOUD/TEMPERATURE TRENDS AS WELL AS SOME WEAK LAKE PROCESSES THROUGH
THIS EVENING. POSSIBLE LATE NIGHT WAA PRECIP WILL ALSO NEED
ADDRESSING.
BASICALLY...WHAT YOU SEE IS WHAT YOU GET TODAY. HAVING A HARD TIME
BELIEVING RATHER AGGRESSIVE DRYING BELOW INVERSION LEVEL NOTED IN
MODEL DERIVED SOUNDINGS. NAM-BUFR INITIATION FAR TOO DRY ALREADY AT
INVERSION LEVEL...AND GIVEN VERY LIGHT WIND FIELDS TODAY (SIMPLY NO
MECHANICAL MIXING)...FEEL CURRENT CLOUD DECK WILL BE AWFULLY HARD
TO "BURN" OFF. WILL CONTINUE TO TREND MORE PESSIMISTICALLY WITH
CLOUD COVER...JUST FEATURING A FEW AFTERNOON BREAKS...BUT STILL
CALLING IT MOSTLY CLOUDY. ONLY PRECIP CONCERNS APPEARS TIED TO
NORTHWEST PUSH OF CURRENT NORTHERN LAKE MICHIGAN MESO-LOW. WILL
INTRODUCE FLURRY WORDING INTO MACKINAC COUNTY THIS MORNING AS THIS
FEATURE MOVES ASHORE. OTHERWISE...DESPITE THE CLOUDY DAY...DRY
CONDITIONS LOOK TO PREVAIL. NOT A WHOLE LOT OF DIURNAL TEMPERATURE
RESPONSE...WITH AFTERNOON READINGS RUNNING IN THE LOWER AND MIDDLE
30S.
STATUS-QUO THROUGH THIS EVENING...WITH PERHAPS A FEW MORE BREAKS
IN THE OVERCAST BEFORE HIGH LEVEL CLOUDS SPREAD ACROSS THE REGION IN
DEVELOPING TOP-DOWN SATURATION REGIME. GUIDANCE TRYING TO SATURATE
THE COLUMN RIGHT TOWARDS SUNRISE DOWN NEAR MANISTEE AS ISENTROPIC
UPGLIDE INCREASES AHEAD OF DEVELOPING CENTRAL PLAINS STORM SYSTEM.
MAIN SHOW SHOULD REMAIN OFF TO OUR WEST...BUT CANNOT COMPLETELY RULE
OUT SOME LIGHT SNOWS BY SUNRISE ACROSS THE FAR SOUTHWEST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 300 AM EST MON DEC 2 2013
TUESDAY AND WEDNESDAY...WEATHER BECOMES MORE ACTIVE TUESDAY AHEAD OF
A WARM FRONT LIFTING INTO THE WRN GREAT LAKES REGION. THIS FRONT IS
ASSOCIATED WITH DEEPENING LOW PRESSURE IN THE NRN PLAINS. EASTERLY
LOW LEVEL WINDS WILL GRADUALLY SHIFT SE ON TUESDAY AS THE WARM FRONT
NEARS...AND THEN TO THE SOUTH ON WEDNESDAY ONCE THE WARM FRONT LIFTS
NORTH OF OUR CWA. WARMER AIR WILL STEADILY SURGE NORTHWARD THRU OUR
CWA BEGINNING TUESDAY MORNING AND CONTINUING THRU MUCH OF WEDNESDAY.
850 MB TEMPS WILL WARM FROM ROUGHLY -4 C ACROSS NRN LWR MICHIGAN AT
12Z TUESDAY TO 6 C BY 12Z WEDNESDAY. PERSISTENT LOW CLOUDS WILL
LIMIT THE AFFECTS OF WAA AT THE SURFACE. AS THE LOW LEVEL TEMP
PROFILE CHANGES...SO WILL PRECIP TYPE AS MOISTURE AND THUS POPS
GRADUALLY INCREASE FROM SW TO NE ACROSS OUR CWA ON TUESDAY. WILL
NEED TO WATCH MODEL SOUNDINGS CLOSELY FOR THE POSSIBILITY OF SOME
SLEET OR FREEZING RAIN TUESDAY AND TUESDAY NIGHT AS WARMER AIR ALOFT
GRADUALLY WORKS ITS WAY NORTHWARD BEFORE THE BOUNDARY LAYER HAS A
CHANCE TO FULLY REALIZE THE WAA. FOR NOW...WILL KEEP PRECIP TYPE
SIMPLE GIVEN ALL OF THE UNKNOWNS THIS FAR OUT. PRECIP TYPE SHOULD
INITIALLY BE ALL SNOW...CHANGING TO A MIX OF RAIN AND SNOW...AND
EVENTUALLY ALL RAIN AS WAA WORKS ITS WAY NORTHWARD THRU OUR CWA
TUESDAY AND TUESDAY NIGHT. BY WEDNESDAY...PRECIP TYPE SHOULD BE ALL
RAIN ACROSS OUR ENTIRE CWA. LATEST NAM CONTINUES TO BE MORE
AGGRESSIVE WITH COLD FROPA...NOW BRINGING THE COLD AIR BACK INTO THE
REGION WEDNESDAY NIGHT. EXPECT RAIN WILL MIX WITH AND CHANGE BACK
OVER TO SNOW FROM NW TO SE DURING THE EVENING...WITH ALL SNOW
EXPECTED BY LATE WEDNESDAY NIGHT AS 850 MB TEMPS COOL BACK TO -4 C
BY 12Z THURSDAY. GIVEN THIS SCENARIO...HIGH TEMPS MAINLY IN THE 30S
ON TUESDAY WILL WARM INTO THE UPPER 30S AND LOWER 40S FOR WEDNESDAY
WHEN WAA WILL PEAK. OVERNIGHT LOWS TUESDAY NIGHT WILL ONLY COOL A
FEW DEGREES...DROPPING BACK INTO THE UPPER 20S TO MID 30S. TEMPS
WILL FALL BACK INTO THE 20S WEDNESDAY NIGHT AS CAA COMMENCES.
THURSDAY THRU SUNDAY...CAA CONTINUES THURSDAY AND FRIDAY AS 850 MB
TEMPS FURTHER COOL TO -20 C BY 00Z SATURDAY. LATEST ECMWF SHOWS
WESTERLY LOW LEVEL FLOW SETTING UP THURSDAY IN THE WAKE OF THE COLD
FRONT...WITH VERY LITTLE CHANGE IN THIS TRAJECTORY THRU SATURDAY
NIGHT. THIS COULD SET THE STAGE FOR A PROLONGED WESTERLY FLOW LAKE
EFFECT SNOW EVENT FOR THE LAST PART OF THE WEEK. THIS POTENTIAL
EVENT IS STILL SEVERAL DAYS OUT WITH TOO MANY UNKNOWNS TO GET TOO
SPECIFIC OR DETAILED AT THIS TIME. WILL CERTAINLY KEEP A CLOSE EYE
ON SUBSEQUENT MODEL RUNS TO SEE HOW THIS SCENARIO EVOLVES. FOR
NOW...WILL HIGHLIGHT HIGHEST POPS ACROSS OUR WESTERLY FLOW AREAS OF
ERN UPR AND NW/N CENTRAL LWR MICHIGAN. SUNDAY LOOKS LIKE A
TRANSITION DAY AS LOW LEVEL FLOW SHIFTS TO THE SOUTH AHEAD OF OUR
NEXT LOW PRESSURE SYSTEM. INCREASING SYNOPTIC LIFT AND MOISTURE ON
SUNDAY SHOULD BRING MORE WIDESPREAD SNOWS TO ALL OF NORTHERN
MICHIGAN. WITH PROGRESSIVE CAA TAKING PLACE THRU THIS TIME...
AFTERNOON HIGHS WILL COOL FROM THE LOWER 30S ON THURSDAY TO THE
UPPER TEENS TO MID 20S FOR SATURDAY. LOW TEMPS WILL BE MAINLY IN THE
TEENS FOR THE LAST PART OF THE WEEK AND THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 134 PM EST MON DEC 2 2013
MAINLY VFR CIGS ACROSS NRN LOWER MICHIGAN THIS AFTERNOON...AND
EXPECTED TO PERSIST THROUGH THE REST OF THE AFTERNOON AND A GOOD
PART OF TONIGHT. NEARLY CALM WINDS ANTICIPATED THROUGH TONIGHT.
AREA OF LOW PRESSURE IN THE PLAINS WILL ORGANIZE TONIGHT AND BEGIN
TO EDGE INTO THE GREAT LAKES TUESDAY. ASSOCIATED WARM FRONT WILL
LIFT INTO THE LOWER LAKES REGION AND EVENTUALLY DRIVE A CORRIDOR
OF PRECIP INTO NRN MICHIGAN...MAINLY TUESDAY AFTERNOON. CIGS WILL
LOWER TO MVFR TUESDAY MORNING AND THERE MAY BE A PERIOD -FZDZ
DURING THE MORNING AS LOW LEVEL MOISTURE DEEPENS.
&&
.MARINE...
ISSUED AT 300 AM EST MON DEC 2 2013
LIGHT WINDS CONTINUE THROUGH THIS EVENING AS WEAK SURFACE
RIDGE CUTS THROUGH THE AREA. EAST TO SOUTHEAST WINDS BEGIN TO PICK
UP TONIGHT WELL AHEAD OF LOW PRESSURE ORGANIZING OVER THE CENTRAL
PLAINS. STRONGER SOUTHEAST WINDS ARRIVE TUESDAY AND TUESDAY
NIGHT...WITH SOME SCA/S POSSIBLE DURING THIS PERIOD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...BA
SYNOPSIS...MR
SHORT TERM...MB
LONG TERM...MR
AVIATION...BA
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1241 PM EST MON DEC 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EST MON DEC 2 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A RELATIVELY LGT
ZONAL FLOW OVER THE UPR GRT LKS TO THE N OF THE MAIN POLAR JET OVER
THE SRN CONUS. AT THE SFC...HI PRES IS PRESENT NEAR JAMES BAY...WITH
A WEAK LO PRES TROF ORIENTED WNW TO ESE OVER UPR MI. THIS TROF HAS
BEEN THE FOCUS FOR SOME LGT -SN MIXED AT TIMES WITH -FZDZ DESPITE
RELATIVELY HI CIGS ASSOCIATED WITH A BIT OF DRIER LLVL AIR SHOWN ON
THE LOCAL 00Z RAOBS BLO SUBSIDENCE INVRN BASE JUST ABV H85. H85
TEMPS ARND -9C RELATIVE TO LK SUP TEMPS ARND 4C HAVE ALSO LIMITED
THE SN INTENSITY. GIVEN THE VERY LGT WIND FIELDS...SFC WINDS AS WELL
AS MQT RADAR IMAGERY INDICATE SOME VORTICES HAVE FORMED OVER THE
RELATIVELY WARM LK WATERS...WITH ONE CENTERED JUST E OF KEWEENAW BAY
AND ANOTHER N OF MUNISING. THERE APPEARS TO BE ANOTHER ONE OVER NRN
LK MI...WHERE THE OPEN WATER TEMP OF 7C REPORTED BY THE 45002 BUOY
AT THE NRN END OF THE LK IS ALLOWING A BIT MORE OVERWATER
INSTABILITY. SINCE THE SFC HI NEAR JAMES BAY IS DRIFTING TO THE
E...THE LLVL WINDS HAVE TENDED TO VEER MORE TO THE S-SW PER THE MQT
88D VWP...ESPECIALLY OVER THE W HALF OF THE CWA. THIS WSHFT IS
CAUSING THE RADAR ECHOES TO DRIFT SLOWLY TO THE N. THIS FLOW ALSO
APPEARS TO BE ADVECTING EVEN DRIER LLVL AIR SHOWN ON THE 00Z MPX AND
QUAD CITIES IA RAOBS TO THE N. ALTHOUGH LOTS OF SC LINGER OVER NRN
WI...THERE HAS BEEN PARTIAL CLRG OVER THE CENTRAL PART OF WI. BUT
MORE WAD CLDS ASSOCIATED WITH ISENTROPIC ASCENT BTWN THE DEPARTING
HI AND LOWER PRES IN THE NRN PLAINS AND BEST DEPICTED ON THE
285-295K SFCS /H85-65/ IS SPREADING QUICKLY TO THE E THRU MN AND
INTO WRN WI. THERE HAS EVEN BEEN SOME -SN AS FAR E AS CNTRL MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LINGERING CHCS FOR -SHSN/
-FZDZ TDAY. FOCUS FOR LATER TODAY AND TNGT SHIFTS TO POPS FOR SN
ASSOCIATED WITH THE ISENTROPIC LIFT SPREADING IN FM THE W.
TODAY...WITH THE CONTINUED TREND FOR THE H925 WINDS TO SHIFT TO THE
S THIS MRNG AND CAUSE THE LO PRES TROF TO DRIFT TO THE N...EXPECT
THE BULK OF LINGERING PCPN OVER UPR MI TO MOVE INTO LK SUP. THE BEST
CHC FOR MORE PCPN MAY BE OVER THE SE COUNTIES AS THE VORTEX NOW
PRESENT OVER NRN LK MI DRIFTS INLAND AS SHOWN BY A NUMBER OF THE HI
RES MODELS. THE QPF FM SOME OF THESE MODELS INDICATES THERE COULD BE
A FEW INCHES OF SN IN THIS AREA...BUT PRESENCE OF THE DGZ ABV THE
MOIST LYR/SHARPER LLVL UVV MAX AS WELL AS MARGINAL OVERWATER
INSTABILITY WITH H85 TEMPS PROGGED TO WARM TOWARD -7 TO -8C BY 00Z
SUG THE PCPN WL BE RELATIVELY LGT AND POSSIBLY EVEN MIXED WITH SOME
-FZDZ. ALTHOUGH THE DRIER NEAR SFC AIR BRINGING CLRG TO PORTIONS OF
CENTRAL WI MAY DRIFT A BIT FARTHER TO THE N THIS MRNG...A TREND FOR
THE SFC-H925 WINDS TO BACK TO THE SE THIS AFTN AND UPSLOPE OFF LK MI
WL LIKELY LIMIT ANY CLRG THAT MIGHT BRIEFLY IMPACT THE FAR SCENTRAL.
THE NAM ALSO SHOWS HIER MID LVL RH ON THE 285-295K SFCS PUSHING INTO
THE W HALF OF THE CWA DURING THE AFTN EVEN THOUGH THE ISENTROPIC
ASCENT APPEARS TO WEAKEN WITH TIME. WL RETAIN CHC POPS OVER THE FAR
W LATER IN THE DAY TO REFLECT THE POTENTIAL FOR SOME OF THE LGT -SN
NOW SHOWING UP AT SOME PLACES IN MN TO IMPACT THAT AREA.
TNGT...MOST OF THE NUMERICAL GUIDANCE SPREADS THE WAD PCPN INTO THE
WRN CWA TNGT WITH THE ARRIVAL OF H85-5 QVECTOR CVNGC AS WELL AS SOME
UPR DVGC IN THE LEFT EXIT REGION OF AN UPR JET SHIFTING E AWAY FM AN
UPR TROF THAT IS FCST TO DEEPEN OVER THE W. THE GFS IS STRONGEST
WITH THIS UPR DVGC AND THE ISENTROPIC ASCENT...GENERATING UP TO 0.75
INCH OF WATER EQUIVALENT PCPN AT IWD BY 12Z TUE...WHERE THE MODEL
ALSO SHOWS A CENTER OF STRONGER H85-7 FGEN. THE BULK OF THE OTHER
MODELS APPEAR TO FOCUS THE BETTER ISENTROPIC ASCENT TO THE S AND
SPIT OUT MUCH LESS PCPN...GENERALLY 0.10 TO 0.30 INCH IN THIS AREA.
CONSIDERING THE DRIER NATURE OF THE AIR TO THE S AND NCEP PREFERENCE
FOR A NON-GFS EVOLUTION...THE LOWER QPF SEEMS MORE RSNBL. BUT DID
BUMP POPS UP TO LIKELY IN THIS AREA...WITH CHC POPS DIMINISHING TO A
DRY FCST OVER THE E.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 505 AM EST MON DEC 2 2013
VERY CHALLENGING FORECAST IN STORE FOR THE TUESDAY THROUGH WEDNESDAY
NIGHT TIME FRAME. BEHIND THIS SYSTEM...LAKE EFFECT SNOW AND WELL
BELOW NORMAL TEMPERATURES ARE EXPECTED TO MOVE IN FOR THE LAST HALF
OF THE WORK WEEK INTO THE WEEKEND WITH DANGEROUS WIND CHILLS
EXPECTED TO APPROACH -30F BY FRIDAY NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...MODEL AGREEMENT HAS INCREASED A
BIT FURTHER FOR THROUGH THIS TIME PERIOD...HOWEVER SLIGHT
DIFFERENCES REMAIN. THE GFS/NAM/EC SOLUTIONS 12Z/03 HAVE A SURFACE
LOW POSITIONED OVER THE SOUTHWEST CORNER OF MN...WHILE THE GEM HAS
BECOME THE MAIN OUTLIER...KEEPING THE SURFACE LOW FARTHER SOUTH OVER
SOUTHEASTERN NE. AT THE SAME TIME AN UPPER LEVEL 500MB CLOSED LOW IS
EXPECTED TO SLOWLY EJECT FROM THE NORTHERN ROCKIES TOWARD THE UPPER
MIDWEST. BY 18Z/03 THE GFS/EC HAVE THE SURFACE LOW SHIFTING
NORTHWARD TOWARD FAR WESTERN LAKE SUPERIOR. AS THIS HAPPENS A WARM
FRONT IS EXPECTED TO LIFT NORTHWARD...REACHING THE SOUTHERN HALF OF
UPPER MI BY 18Z TUES. ISENTROPIC UPGLIDE ALONG THIS FRONT ALONG WITH
INCREASED MOISTURE ON THE 295K ISOSURFACE WILL ALLOW PRECIPITATION
TO FORM AND SPREAD ACROSS MUCH OF THE U.P. BY 18Z/03. BY 06Z
WEDNESDAY THE GFS HAS THE SURFACE LOW DIRECTLY OVER THE WESTERN HALF
OF UPPER MI...WHILE THE 00Z RUN OF THE EC KEEPS THE LOW LESS INTENSE
AND FARTHER SOUTH OVER NORTHERN MO. IF THE GFS IS CORRECT
PRECIPITATION WOULD START EARLIER OVER THE U.P...WHILE THE EC WOULD
SLOW THE PRECIP DOWN BY ABOUT 6 HOURS. TRIED TO ACCOUNT FOR THE
DISCREPANCIES BY SLOWING THE ONSET OF LIKELIES BY A FEW HOURS. BOTH
THE GFS AND EC EVENTUALLY HAVE THE LOW CROSSING THE WESTERN HALF OF
THE U.P. WHICH WILL KEEP THE EASTERN HALF OF THE U.P. IN THE WARM
AIR ADVECTING INTO THE REGION ALONG WITH CONTINUED ISENTROPIC
UPGLIDE ACROSS THOSE AREAS...ALLOWING THE PRECIPITATION TO
TRANSITION INTO A RAIN SNOW MIXTURE DURING THAT TIME FRAME. THIS
WOULD HELP KEEP SNOWFALL TOTALS BELOW ADVISORY CRITERIA IN THOSE
AREAS. AS THE PREVIOUS SHIFT MENTIONED...AS THE SNOW TRANSITIONS TO
RAIN...THE POTENTIAL EXISTS FOR THE PRECIPITATION TO FREEZE ON BELOW
FREEZING/UNTREATED SURFACES CAUSING SLIPPERY CONDITIONS. THE FAR
WESTERN PORTION OF THE U.P. WILL LIKELY STAY COOL ENOUGH TO REMAIN
ALL SNOW THROUGH THIS EVENT...KEEPING THE POTENTIAL FOR AT LEAST
ADVISORY SNOW OVER THE FAR WESTERN COUNTIES FROM IWD TO NEAR COPPER
HARBOR. AT THIS POINT...WITH CONTINUED MODEL DISAGREEMENT...HAVE
DECIDED AGAINST A HEADLINE. BETWEEN 12Z/04 AND 00Z/05 THE LOW SHIFTS
TO NORTHERN LAKE SUPERIOR ALLOWING THE PRECIPITATION TO TAPER OFF
ACROSS MOST OF THE U.P. AS THE DRY SLOT AND COLD FRONT PASS THROUGH
THE AREA. THE BETTER FORCING AND MOISTURE AT THAT TIME WILL SHIFT
INTO ONTARIO. ANOTHER ISSUE THAT WILL COME ALONG WITH THIS SYSTEM
WILL BE THE POSSIBILITY OF EASTERLY GALE FORCE WINDS ON LAKE
SUPERIOR AS THE LOW INTENSIFIES AND SHIFTS INTO THE U.P. THE BEST
TIME FRAME FOR THIS TO OCCUR WOULD BE 00Z/04 THROUGH 12Z/04. 850MB
WINDS ARE PROGGED TO BE AROUND 30 KNOTS. WHILE TEMPERATURES ARE NOT
TERRIBLY COLD AT 850MB WITH TEMPS RUNNING AROUND 0C TO
-2C...HOWEVER...THIS MAY BE ENOUGH TO ALLOW THE STRONGER WINDS TO
MIX TO THE SURFACE OF THE LAKE AS THE LAKE SURFACE TEMPS ARE RUNNING
AROUND 4C TO 5C. AGAIN THIS IS LARGELY DEPENDENT UPON THE SYSTEM
STRENGTH AND TIMING...WITH BELOW AVERAGE CONFIDENCE.
THURSDAY THROUGH SUNDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME...HOWEVER
THE GFS IS STILL MORE PROGRESSIVE AND SLIGHT FARTHER NORTH THAN THE
EC. THE GFS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY
12Z THURSDAY...WHILE THE EC PLACES THE SURFACE LOW JUST SOUTH OF
JAMES BAY. EITHER WAY...THIS PLACES THE UPPER PENINSULA IN A
WESTERLY TO WEST NORTHWESTERLY FLOW. 850MB TEMPERATURES DURING THIS
TIME ARE EXPECTED TO DROP TO -11C TO -15C WITH LAKE SURFACE
TEMPERATURES AROUND 4C TO 5C. THIS WILL CREATE FAVORABLE CONDITIONS
FOR LAKE EFFECT SNOW TO DEVELOP ACROSS THE AREA. THE SURFACE LOW
WILL REMAIN NEARLY STATIONARY THROUGH SATURDAY AS ANOTHER UPPER
LEVEL 500MB TROUGH AXIS SWINGS INTO THE AREA FRIDAY NIGHT. THIS WILL
BRING SOME OF THE COLDEST AIR SO FAR THIS SEASON INTO THE AREA.
850MB TEMPS ARE PROGGED TO DROP TO AROUND -22C DURING THIS TIME
FRAME...AGAIN ALLOWING A CONTINUATION OF LAKE EFFECT SNOWFALL. HAVE
KEPT WITH THE LIKELY POPS ACROSS WESTERLY WIND FAVORED SNOW BELTS OF
THE U.P....HOWEVER...THIS EVENT WILL LIKELY BE A LONG DURATION EVENT
WITH MODERATE SNOWFALL TOTAL EXPECTED BY THE END OF THE EVENT.
AGAIN...IT IS LIKELY THAT LES WILL OCCUR...IT IS JUST UNLIKELY THAT
THE SNOWFALL RATES WILL BE UNUSUALLY HIGH AT THIS POINT AS THE MORE
FAVORABLE SNOW GROWTH ZONE WILL BE VERY SHALLOW AND INVERSION
HEIGHTS EXPECTED TO BE AROUND 5-6KFT...EVEN AFTER ADJUSTING FOR THE
WARMER LAKE SURFACE TEMPERATURES. THE SNOWFALL TOTALS AND EXACT
LOCATION OF THIS LONGER DURATION EVENT WILL CONTINUE TO BE FINE
TUNED AS THE WEEKEND APPROACHES. ANOTHER PERHAPS MORE DANGEROUS
ASPECT OF THIS WINTER WEATHER EVENT WILL BE THE POTENTIAL FOR A
DANGEROUSLY COLD AIRMASS TO BUILD INTO THE REGION THURSDAY NIGHT
THROUGH SATURDAY NIGHT. WITH 850MB TEMPS AROUND THE -22C MARK AS
PREVIOUSLY MENTION...LOW TEMPERATURES WILL LIKELY FALL INTO THE
TEENS BELOW ZERO WITH DAYTIME HIGHS ONLY REACHING INTO THE SINGLE
DIGITS ABOVE ZERO FOR WESTERN PORTIONS OF THE U.P. WINDS WILL ALSO
BE FAIRLY STRONG ALLOWING WIND CHILLS TO DROP AS LOW AS -30F DURING
THE OVERNIGHT HOURS THROUGH THIS TIME FRAME. SUNDAY MAY BEGIN TO
BRING A BIT OF RELIEF...HOWEVER...AS THE SURFACE LOW AND UPPER LEVEL
500MB TROUGH NEAR JAMES BAY FINALLY BEGINS TO SHIFT EASTWARD. THIS
WILL SLOWLY DIMINISH THE CHANCE OF LES AS A BRIEF RIDGE BUILDS. THIS
WILL ALSO ALLOW TEMPERATURES TO MODERATE SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1240 PM EST MON DEC 2 2013
DISTURBANCE APPROACHING FROM THE NRN PLAINS WILL SPREAD -SN FROM W
TO E ACROSS THE AREA THIS AFTN AND TONIGHT. PRIOR TO THE ARRIVAL OF
-SN...VFR CONDITIONS WILL PREVAIL...THOUGH DEVELOPING UPSLOPE
FLOW WILL PROBABABLY LEAD TO MFVR CIGS DEVELOPING AT KCMX/KSAW LATER
THIS AFTN/EARLY THIS EVENING...WELL BEFORE THE ONSET OF -SN AT THOSE
TERMINALS. SEVERAL HRS AFTER THE -SN BEGINS AT EACH TERMINAL...
CONDITIONS WILL DETERIORATE TO IFR. MAY SEE SOME IMPROVEMENT AT KIWD
TUE MORNING AS STEADIER -SN SHIFTS E AND NE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EST MON DEC 2 2013
A LIGHT S WIND TODAY WILL BACK TOWARD THE E AND INCREASE UP TO 30
KTS BY TUE AS THE PRES GRADIENT TIGHTENS OVER THE UPPER GREAT LAKES
BETWEEN DEPARTING HI PRES OVER SE CANADA AND A LO PRES SYSTEM MOVING
E FROM THE PLAINS. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE SOME MARGINAL GALES ON TUE INTO TUE NIGHT...
ESPECIALLY WHERE THE TERRAIN SURROUNDING THE LAKE ENHANCES THE E
FLOW. ALTHOUGH WINDS WILL DIMINISH A BIT THRU WED AS THE LO AND
FLATTER GRADIENT MOVES OVERHEAD...EXPECT A STRONGER W WIND TO 30 TO
35 KTS TO DEVELOP FOLLOWING THE PASSAGE OF THE LO INTO ONTARIO ON
WED NIGHT/THU. SINCE THIS WIND WILL ADVECT VERY COLD AIR OVER THE
RELATIVELY WARM WATERS...INCREASING INSTABILITY WILL ENHANCE THE
WINDS AND LIKELY REQUIRE GALE WARNINGS THU THRU FRI FOR AT LEAST
PORTIONS OF THE BIG LAKE. INCREASING WAVES AND THE ARRIVAL OF THE
ARCTIC AIRMASS WILL ALSO CAUSE WIDESPREAD FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION..ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1120 AM CST MON DEC 2 2013
.AVIATION 18Z DISCUSSION...
LOW CLOUDS TO PERSIST THROUGH THE UPCOMING TAF PD. DEWPOINT
DEPRESSIONS WILL LOWER AFT 00Z...ESPECIALLY AT CSV. THUS...IN
ADDITION TO THE LOW CLOUDINESS...VSBYS WILL LOWER AS FOG RETURNS
LATE TONIGHT. SOME IMPROVEMENT IS INDICATED AFT 12Z. SOME PATCHY
DRIZZLE WILL BE POSSIBLE AS WELL AFT 06Z AT CSV.
&&
.PREV DISCUSSION... /ISSUED 947 AM CST MON DEC 2 2013/
UPDATE...
WEAK SHORTWAVE PULLING ACROSS THE DEEP SOUTH THIS HOUR.
THUS...SHOWER ACTIVITY REMAIN SOUTH OF MIDDLE TN BUT CLOUDINESS
SHOULD REMAIN IN PLACE THROUGH THE DAY. DYNAMICS FOR THE REMAINDER
OF THE DAY ARE DIFFICULT TO COME BY. CURRENT FCST DOES CARRY A
CHANCE OF SPRINKLES NORTH AND A SLIGHT CHANCE OF SHOWERS SOUTH.
ISENTROPIC ANALYSIS SHOWS A DECREASE IN CONDENSATION DEFICITS
THROUGH THE DAY IN THE LOWER LEVELS. FURTHERMORE...ISENTROPIC
UPGLIDE IN THE LOWER LEVELS SHOULD CONTINUE. LATEST HRRR INFO DOES
INDICATE SOME LIGHT REFLECTIVITY RETURN LATER TODAY.
THEREFORE...WILL OPT TO CONTINUE WITH THE CURRENT WEATHER GRIDS.
OTW...ONLY OTHER CHANGE WILL BE TO RAISE HIGH TEMPS A DEGREE OR
SO. 18Z GRAPHICAL PROGS SUGGEST THAT TEMPS WILL BE NEARING THE MID
50S FOR MANY AREAS WEST OF THE PLATEAU BY 18Z OR 19Z.
UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 528 AM CST MON DEC 2 2013/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...LOW LEVEL MOISTURE WILL PERSIST...KEEPING MVFR CIGS
ACROSS THE AREA THROUGH THIS PERIOD. ANY -RA WILL BE SCT AND VERY
LIGHT...SO NOT INCLUDING ANY IN TAFS. WINDS WILL BE LIGHT FROM THE
SOUTH THROUGH THE NEXT 24 HOURS.
13
PREV DISCUSSION... /ISSUED 358 AM CST MON DEC 2 2013/
SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
EARLY THIS MONDAY MORNING...SKIES WERE OVERCAST WITH MILD TEMPERATURES
FOR DECEMBER...IN THE 40S. SCATTERED LIGHT SHOWERS WERE MOVING
ACROSS THE FAR SOUTHERN COUNTIES OF MID TN.
TODAY WILL BE MUCH LIKE YESTERDAY...WITH PERSISTENT CLOUDS AND HIGHS
IN THE 50S. THE MAIN SHORTWAVE TROUGH PRODUCING THE SOUTHERN SHOWERS
WILL MOVE EAST...BUT SOME WEAK TROUGHING AND LIFT WILL PERSIST...SO
WE WILL KEEP 20 POPS TODAY. ANY RAINFALL WILL MEASURE LESS THAN ONE
TENTH OF AN INCH.
FOR TONIGHT AND TUESDAY...BOUNDARY LAYER MOISTURE WILL REMAIN
HIGH...BUT NO SIGNIFICANT LIFT IS NOTED...SO CLOUDY SKIES WILL
PRODUCE JUST A FEW SPRINKLES. SOUTHERLY LOW LEVEL WINDS COMBINED
WITH SLIGHTLY BACKING UPPER LEVEL FLOW WILL BRING MILD
TEMPERATURES...CLIMBING INTO THE 60S ON TUESDAY.
FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THERE ARE SOME MODEL
DIFFERENCES. THE GFS AND NAM EJECT A FAIRLY STRONG SHORTWAVE ACROSS
THE NORTHERN PLAINS AND GREAT LAKES WHICH PUSHES A COLD FRONT INTO
OUR AREA ON WEDNESDAY. A FEW GEFS MEMBERS AND THE MORE CONSISTENT
ECMWF SHOW A MUCH WEAKER OR FARTHER WEST SYSTEM...WHICH WOULD HOLD
THE FRONT BACK 24 HOURS SLOWER THAN THE GFS. WE LIKE THIS SOLUTION
BETTER...AND WPC SUPPORTS THE ECMWF ENSEMBLE BLEND. THIS TIMING WILL
MAKE A HUGE DIFFERENCE FOR TEMPERATURES IN THE WEDNESDAY THROUGH
THURSDAY PERIODS. BASED ON THE SLOWER FRONT...WE WILL FORECAST VERY
MILD TEMPERATURES MIDWEEK. HIGHS WEDNESDAY WILL CLIMB WELL INTO THE
60S WITH GUSTY SOUTH WINDS. 70+ WILL BE ACHIEVABLE IF CLOUDS BREAK
UP ENOUGH. LOWS TUESDAY NIGHT AND WEDNESDAY NIGHT WILL BE MANLY IN
THE 50S...BUT THE INCOMING COLD FRONT MAY DROP OUR NORTHWEST COUNTIES
QUICKLY DOWN INTO THE 40S LATE WEDNESDAY NIGHT. THE CHANCE FOR
SHOWERS WILL INCREASE AS THE COLD FRONT APPROACHES.
13
LONG TERM...(THURSDAY THROUGH SUNDAY)
A MESSY PATTERN WITH POTENTIALLY SIGNIFICANT RAINFALL AND WINTER
WX IS EXPECTED. CONTINUED MOIST SOUTHWEST FLOW ALOFT WILL INTERACT
WITH AN ARCTIC INTRUSION. TEMPERATURES WILL BE NEARLY STEADY OR
FALL THURSDAY AS THE COLD FRONT MOVES ACROSS THE MID STATE WITH
WIDESPREAD RAIN. THE RAIN WILL CONTINUE AS DEEP MOISTURE STREAMS
ACROSS THE SLOW MOVING FRONTAL ZONE THURSDAY NIGHT AND FRIDAY.
RAINFALL TOTALS OF 2 TO 4 INCHES ARE EXPECTED. THE COLD AIR WILL
BE GRADUALLY BUILDING FROM THE NORTHWEST...WITH ENOUGH COLD AIR
DEPTH TO PRODUCE SOME MIXED WINTRY PRECIPITATION OVER OUR
NORTHWEST COUNTIES LATE THURSDAY NIGHT AND FRIDAY.
MODELS ARE IN GOOD AGREEMENT WITH A TRANSITION TO WINTRY
PRECIPITATION ACROSS THE AREA FRIDAY NIGHT...WITH THE
PRECIPITATION COMING TO AN END SATURDAY MORNING. RAIN IS EXPECTED
TO TRANSITION TO SLEET AND SNOW...THEN TAPER OFF WITH A BRIEF
PERIOD OF FREEZING DRIZZLE POSSIBLE SATURDAY MORNING. HAZARDOUS
TRAVEL CONDITIONS ARE A GOOD BET DURING THIS TIME PERIOD WITH
TEMPERATURES FALLING INTO THE 20S FRIDAY NIGHT.
WE WILL HAVE DRY WX BY SATURDAY AFTERNOON WITH VERY COLD AND DRY
AIR. OUR TEMPERATURE FORECAST WILL UNDERCUT GFS MOS SUBSTANTIALLY
FOR SATURDAY...AND THROUGH THE ENTIRE WEEKEND BASED ON THE
STRENGTH OF THE COLD DENSE ARCTIC AIR MASS. ANOTHER WAVE AND SURGE
OF MOISTURE WILL BRING ANOTHER SHOT OF WINTRY WX SATURDAY
NIGHT...MOST LIKELY IN THE FORM OF A SNOW AND SLEET MIXTURE. THIS
MIX WILL GRADUALLY TRANSITION TO SLEET...FREEZING RAIN...AND
EVENTUALLY TO ALL RAIN BY MONDAY AS A STRONG WARM NOSE ALOFT
DEVELOPS FROM SOUTHEAST TO NORTHWEST. BEFORE THIS TRANSITION IS
COMPLETE...SOME SIGNIFICANT ICE PROBLEMS WILL BE
POSSIBLE...ESPECIALLY OVER THE NORTHWEST HALF OF THE MID STATE.
19/13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1150 AM CST MON DEC 2 2013
.AVIATION...
/18Z TAFS/
RADIATION FOG HAS CONTINUED TO BURN OFF READILY EXCEPT ACROSS
NORTHEAST PARTS OF NORTH TEXAS...BUT THIS DOES NOT INCLUDE ANY
NORTH AND CENTRAL TAF AIRPORTS.
THROUGH 10Z TUESDAY...VFR CONDITIONS WILL PREVAIL WITH JUST
SCATTERED CIRRUS TRANSVERSING OVER THE ARE WITHIN NW FLOW ALOFT.
MIXING WILL ALLOW SSW WINDS 10-15 BY MID AFTERNOON AND CONTINUING
THROUGH THIS EVENING...BEFORE DIMINISHING BACK TO 5-7 KTS.
BY SUNRISE TUESDAY...THERE IS SOME CONFLICT ON DEW POINT SPREADS
WITH THE RUC AND NAM BUFR SOUNDINGS AND GFS LAMP MOS INDICATING AT
LEAST SOME POTENTIAL FOR LIGHT RADIATIONAL FOG ONCE AGAIN. HAVE
PLAYED THE MIDDLE FOR NOW THIS FAR OUT AND AND HAVE INTRODUCED
RESTRICTIONS BACK INTO THE MVFR CATEGORY FOR NOW. IT WILL BE A
MONITORING PROCESS THROUGH THE NIGHT ON SUBSEQUENT FORECASTS
REGARDING ANY VSBY RESTRICTIONS EARLY TUESDAY.
OTHERWISE...VFR CONDITIONS AND SSW WINDS NEAR 10 KTS WILL RETURN
DURING THE DAY TUESDAY.
05/
&&
.UPDATE...
WE ARE NOT ISSUING UPDATED PRODUCTS AT MIDDAY...BUT WILL INSTEAD
CONCENTRATE ON THE EXTENDED FORECAST AND TYPES OF EXPECT
PRECIPITATION. NEWEST MODEL RUNS HAVE A SIMILAR FROPA AS PREVIOUS
RUNS...BUT SEEM TO HAVE BACKED OFF ON THE AMOUNTS OF QPF THAT FALL
ACROSS THE CWA. 75
&&
.PREV DISCUSSION... /ISSUED 418 AM CST MON DEC 2 2013/
AREAS OF DENSE FOG HAVE FORMED ACROSS MUCH OF NORTH AND CENTRAL
TEXAS OVERNIGHT AS SKIES CLEARED AND A WEAK FRONTAL BOUNDARY MOVED
SOUTHWARD. THUS HAVE EXPANDED THE DENSE FOG ADVISORY TO COVER ALL
OF THE FORECAST AREA. THE FOG SHOULD DISSIPATE MID TO LATE MORNING.
SKIES SHOULD BECOME MOSTLY SUNNY BY MIDDAY. TEMPERATURES THIS
AFTERNOON WILL WARM INTO THE MID 60S NORTHEAST TO THE LOWER TO
MID 70S SOUTH.
MILD TEMPERATURES AND DRY WEATHER WILL CONTINUE THROUGH TUESDAY
NIGHT. LOWS TONIGHT WILL BE IN THE LOWER 40S NORTHWEST TO MID 50S
SOUTHEAST AND HIGHS TUESDAY WILL BE THE WARMEST THAT WE WILL SEE
FOR THE NEXT WEEK RANGING FROM THE LOWER 70S NORTHEAST TO LOWER
80S WEST.
THE TIMING OF THE NEXT FRONT IS STILL IN QUESTION AS THE MODELS
CONTINUE TO HANDLE IT DIFFERENTLY. THE GFS IS BY FAR THE FASTEST
SOLUTION BRINGING THE FRONT THROUGH OVERNIGHT TUESDAY NIGHT WHILE
THE ECMWF BRINGS THE FRONT SOUTH OF THE RED RIVER AROUND MIDDAY
WEDNESDAY BUT STALLS IT OUT BEFORE A STRONGER SURGE OCCURS
WEDNESDAY NIGHT. THE NAM INDICATES THAT THE FRONT WILL ENTER
NORTH TEXAS WEDNESDAY MORNING BUT WILL NOT REACH THE SOUTH UNTIL
NEAR DAYBREAK THURSDAY. THE CMC SOLUTION BRINGS THE FRONT INTO
NORTH TEXAS WEDNESDAY MORNING AND THROUGH THE SOUTH DURING THE
AFTERNOON. HAVE BLENDED THE MODELS BRINGING THE FRONT INTO THE
NORTHWEST OVERNIGHT TUESDAY NIGHT BUT NOT THROUGH THE SOUTHEAST
UNTIL WEDNESDAY EVENING.
RAIN CHANCES WILL START OVERNIGHT WEDNESDAY NIGHT AND INCREASE
THROUGH THURSDAY NIGHT AS AN UPPER LEVEL TROUGH APPROACHES.
TEMPERATURES WILL FALL TO BELOW FREEZING BY DAYBREAK FRIDAY
ACROSS THE NORTHWEST HALF OF NORTH TEXAS WHICH SHOULD RESULT IN
SOME FREEZING RAIN LATE THURSDAY NIGHT INTO FRIDAY MORNING. THE
EXACT LOCATION OF THE FREEZING LINE IS STILL QUITE IN QUESTION...
BUT IT LOOKS TO BE NEAR A PARIS TO WAXAHACHIE TO LAMPASAS LINE.
THE NORTHWESTERN ZONES SEEM TO BE THE ALMOST CERTAIN AREAS FOR
FREEZING TEMPERATURES AND THE FREEZING LINE COULD END UP BEING TO
THE SOUTHEAST OF THE CURRENT FORECAST.
THE PRECIPITATION SHOULD COME TO AN END FROM WEST TO EAST LATE
FRIDAY MORNING INTO THE AFTERNOON. WITH ENERGY FROM THE UPPER
LEVEL TROUGH HANGING BACK...THERE WILL BE ADDITIONAL CHANCES
OF PRECIPITATION SATURDAY AND SUNDAY. SOME WINTRY MIX OF RAIN...
FREEZING RAIN AND SLEET WILL BE POSSIBLE. 58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 70 49 77 49 61 / 0 0 5 10 10
WACO, TX 71 51 78 52 71 / 0 0 5 10 10
PARIS, TX 65 48 72 49 60 / 0 5 5 10 10
DENTON, TX 67 45 75 43 58 / 0 0 5 10 10
MCKINNEY, TX 68 47 75 47 60 / 0 0 5 10 10
DALLAS, TX 70 50 78 51 62 / 0 0 5 10 10
TERRELL, TX 68 49 75 52 65 / 0 0 5 10 10
CORSICANA, TX 69 52 77 55 69 / 0 0 5 10 10
TEMPLE, TX 74 52 80 54 73 / 0 0 5 10 10
MINERAL WELLS, TX 69 42 78 40 59 / 0 0 5 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/75
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
332 PM CST MON DEC 2 2013
ADDED AVIATION AND MARINE SECTIONS
.TONIGHT AND TUESDAY...FORECAST CONFIDENCE MEDIUM.
THE FIRST WAVE OF PRECIPITATION IS APPARENT ON RADAR AS A NARROW
BAND WITH DECENT REFLECTIVITY OVER FAR EASTERN MN AND EASTERN IOWA
AT 3 PM THIS AFTERNOON. THIS IS ASSOCIATED WITH A WEAK BAND OF 850-
600MB FRONTOGENESIS AND PERSISTENT 925-850MB WARM AIR ADVECTION AND
MODEST 700MB OMEGA. MOST OBSERVATIONS BENEATH THE BAND SHOW SNOW IN
MN AND RAIN IN IOWA. THIS HAS A STEADY TRACK EASTWARD AND SHOULD
ARRIVE IN MADISON AROUND 1Z OR 7 PM AS PROBABLY WET SNOW. SINCE IT
WILL ONLY LAST UP TO TWO HOURS AND FALLING INTO SURFACE TEMPS ABOVE
FREEZING...NO ACCUMULATION IS EXPECTED. 19Z HRRR MODEL SEEMS TO HAVE
A HANDLE ON THE PRECIP FOR THE EVENING. TIMING FOR MILWAUKEE RAIN
LOOKS LIKE 4Z TO 8Z.
PRECIP TYPE IS MORE UNCERTAIN ACROSS THE NORTHERN MKX FORECAST AREA.
EXPECTING MAINLY SNOW HERE WITH UP TO A HALF INCH OF ACCUMULATION.
SURFACE TEMPERATURES WILL BE A BIT COOLER HERE...SO THERE IS A SMALL
POSSIBILITY FOR FREEZING DRIZZLE IF THERE ARE POCKETS OF AIR BELOW
FREEZING.
EXPECTING A BREAK IN RAIN AFTER THIS FIRST BAND MOVES THROUGH. THERE
COULD BE DRIZZLE AS MID LEVELS DRY OUT A LITTLE PER MODEL SOUNDINGS.
THEN ANOTHER ROUND OF RAIN IS EXPECTED ACROSS SOUTHERN WI TUESDAY
MORNING WHICH COULD PERSIST THROUGH THE AFTERNOON. THERE IS ANOTHER
WAVE OF FRONTOGENESIS...850MB WARM AIR ADVECTION AND 700MB OMEGA
WITH A 500MB VORT MAX. EXPECTING STRATIFORM RAIN OFF AND ON THROUGH
MUCH OF THE DAY TUESDAY WITH LOW CLOUDS AND LIGHT FOG...AS WELL AS
A 10MPH SOUTHEAST BREEZE WITH HIGHER GUSTS.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS LOW TO
MEDIUM.
CONFIDENCE IS CERTAINLY CHALLENGED THIS PERIOD AS THE MAJOR MODEL
SIMULATIONS CONTINUE TO HAVE TWO VERY DIFFERENT SOLUTIONS. WE
HAVE THE MORE AMPLIFIED AND FASTER SOLUTION OF THE GFS/NAM...AND
THE SLOWER...DELAYED AMPLIFICATION OF THE ECMWF/GEM. TO BE THIS
CLOSE TO THE EVENT AND CONTINUE TO SEE SUCH PERSISTENT DISPARITY
IN MODEL RUNS IS PRETTY UNUSUAL. DISCUSSION FROM THE MODEL
DIAGNOSTIC FOLKS SUGGEST THE GFS/NAM ARE TOO AMPLIFIED GIVEN
DOWNSTREAM CHARACTERISTICS. THE APPROACH HAS BEEN TO TAKE A
CONSENSUS/BLEND WITH A STRONGER NOD TOWARD THE SLOWER SOLUTIONS.
FOR US...OUR ISSUES ARE MINOR COMPARED TO OUR NEIGHBORS TO THE
NORTH THAT HAVE TO DEAL WITH THE POTENTIAL OF BIG SNOWFALL
AMOUNTS. WE WILL BE WARM ENOUGH TO KEEP ANY PRECIPITATION IN THE
FORM OF RAIN. WE COULD SEE SOME SNOW MIX IN RIGHT ALONG AND BEHIND
THE COLD FRONT MOVING THROUGH ON WEDNESDAY. JUST WHEN THAT FRONT
MOVES THROUGH WILL HAVE TO GET WORKED OUT OVER THE NEXT COUPLE OF
DAYS. BUT CURRENT THINKING HAS IT COMING THROUGH MADISON AROUND
MID DAY WEDNESDAY AND MILWAUKEE ABOUT MID AFTERNOON.
.WEDNESDAY NIGHT AND BEYOND...FORECAST CONFIDENCE IS MEDIUM.
WE COULD SEE SOME FLURRIES OR VERY LIGHT SNOW WEDNESDAY NIGHT
UNDER A STRONG COLD AIR ADVECTION PATTERN IN THE WAKE OF THE COLD
FRONT. TEMPERATURES WILL FALL PRETTY HARD...BUT HAVE BACKED OFF A
BIT FOR WEDNESDAY NIGHT AND THURSDAY GIVEN THE POTENTIAL FOR A
SLOWER INFLUX OF COLD AIR DEPICTED BY THE ECMWF/GEM SOLUTIONS.
BUT...THE COLD AIR WILL BE WELL ESTABLISHYED BY FRIDAY...
LINGERING THROUGH THE WEEKEND. WE/RE STILL LOOKING AT HIGHS FRIDAY
AND SATURDAY IN THE TEENS...MODERATING A BIT INTO THE 20S BY
SUNDAY AND MONDAY. LOWS WILL BE IN THE SINGLE DIGITS. THE GFS AND
ECMWF ARE BRINGING A WEAKISH LOOKING LOW PRESSURE SYSTEM THROUGH
THE OHIO VALLEY ON SUNDAY THAT COULD BRING SOME LIGHT SNOW TO THE
AREA.
&&
.AVIATION/00Z TAFS/...
MID LEVEL CLOUDS WILL LOWER THROUGHOUT THE EVENING. A NORTH TO SOUTH
ORIENTED BAND OF PRECIPITATION WILL MOVE EASTWARD ACROSS SOUTHERN WI
THIS EVENING...THEN HANG UP IN A WEST TO EAST ORIENTATION ACROSS
CENTRAL WI LATE TONIGHT THROUGH TUESDAY. PRECIP SHOULD START AS WET
SNOW IN MADISON AND NORTH OF MADISON THEN TRANSITION TO RAIN OVER
TIME TONIGHT. MILWAUKEE AND SOUTH WILL BE MAINLY RAIN. WITH SURFACE
TEMPS ABOVE FREEZING FOR THE NIGHT...NOT EXPECTING ACCUMULATION
EXCEPT POSSIBLY IN FOND DU LAC AND SHEBOYGAN AREAS. AFTER THE BAND
PASSES...THERE COULD BE DRIZZLE AND LIGHT FOG AND IFR OR LOWER
CEILINGS LATE TONIGHT THROUGH TUESDAY MORNING.
ANOTHER ROUND OF LIGHT RAIN IS EXPECTED TO SPREAD NORTHEASTWARD
ACROSS SOUTHERN WI TUESDAY MORNING AND PERSIST THROUGH MUCH OF THE
DAY ALONG A WARM FRONT. IFR CIGS SHOULD IMPROVE TO FUEL ALTERNATE
THE AFTERNOON FROM MILWAUKEE AND MADISON SOUTHWARD.
&&
.MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT FOR AREAS NORTH OF THE NORTH
POINT LIGHT FROM MIDNIGHT TONIGHT THROUGH WEDNESDAY MORNING. AREAS
SOUTH OF NORTH POINT LIGHT MAY NEED TO BE ADDED. INCREASING
SOUTHEAST WINDS TONIGHT THROUGH TUE AFTERNOON WILL LEAD TO HIGH
WAVES. EXPECT WAVES TO SUBSIDE AS WINDS BECOME OFFSHORE...SOMETIME
WEDNESDAY MORNING. A STRONG COLD FRONT WILL THEN SWEEP EAST ACROSS
LAKE MI ON WED. BRISK AND GUSTY WNWLY FLOW WILL THEN PREVAIL THE
REMAINDER OF THE WEEK. A SMALL CRAFT ADVISORY MAY BE NEEDED ALL THE
WAY INTO SATURDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST WEDNESDAY
FOR LMZ643-644.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...DAVIS