Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/01/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
830 PM MST SAT NOV 30 2013
.SYNOPSIS...MOSTLY CLOUDY CONDITIONS WILL CONTINUE INTO SUNDAY UNDER
SOUTHWEST FLOW ALOFT. OTHERWISE MILD AND DRY CONDITIONS FOR THE
REMAINDER OF THE WEEKEND INTO EARLY NEXT WEEK. AN AREA OF LOW
PRESSURE NEAR JUNEAU ALASKA THIS EVENING WILL DIVE INTO THE PACIFIC
NORTHWEST BY MONDAY AND THEN MOVE SLOWLY THROUGH THE WESTERN STATES
FOR MUCH OF NEXT WEEK. THIS SYSTEM WILL BRING A CHANCE OF VALLEY
RAIN AND MOUNTAIN SNOW TO SOUTHEAST ARIZONA LATE TUESDAY NIGHT
THROUGH FRIDAY MORNING. THIS SYSTEM WILL ALSO BRING LOWER SNOW
LEVELS...GUSTY WINDS AND MUCH COOLER TEMPERATURES. THE FIRST
WIDESPREAD FREEZE FOR THE LOWER DESERTS IS POSSIBLE FRIDAY MORNING.
&&
.DISCUSSION...THICK SHEAVES OF HIGH AND MID CLOUD CONTINUE TO STREAM
UP FROM THE SOUTHWEST IN A RATHER LONG FETCH FROM THE
TROPICS...STRETCHING ALL THE WAY FROM ABOUT 10-12 DEGREES NORTH
LATITUDE RIGHT THROUGH SOUTHEAST ARIZONA. HRRR CONTINUING TO SHOW
LIGHT PRECIP DEVELOPING THROUGH NORTHEAST SONORA AROUND 9 PM AND
CLIPPING SOUTHEAST COCHISE COUNTY INCLUDING THE DOUGLAS AREA BETWEEN
10 PM AND MIDNIGHT. CONSIDERING SATELLITE TRENDS WITH MODEST
PRECIPITABLE WATER INCREASE TO A LITTLE OVER 1/2 INCH A FEW
SPRINKLES OR A LIGHT SHOWER NOT AT ALL OUT OF THE QUESTION FOR
SOUTHEAST COCHISE COUNTY LATE THIS EVENING.
CURRENT FORECAST TRENDS HITTING THE STRONG AND COLD SYSTEM IMPACTING
THE AREA THE SECOND HALF OF NEXT WEEK LOOKS GOOD. INCREASING LEVELS
OF PREDICTABILITY WITH ECMWF ENSEMBLE AND CONSENSUS TRENDS SUPPORT
AN AGGRESSIVE APPROACH WITH AN UNUSUALLY STRONG AND COLD SYSTEM FOR
EARLY DECEMBER.
&&
.PREV DISCUSSION...THE FIRST DAY OF DECEMBER WILL BE MOSTLY CLOUDY
WITH HIGHS CLOSE TO TODAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE
ON MONDAY AND TUESDAY BEFORE A SIGNIFICANT CHANGE IN THE WEATHER
OCCURS...STARTING WEDNESDAY AND CONTINUING THROUGH NEXT WEEKEND.
OUTSIDE OF A CHANCE OF PRECIPITATION ON LATE TUESDAY NIGHT THROUGH
FRIDAY MORNING...THE MAIN WEATHER CONCERN WILL BE THE MUCH MUCH
COLDER TEMPERATURES AS AN ARCTIC AIR MASS SETTLES IN OVER THE AREA.
CONFIDENCE IS GROWING FOR A WIDESPREAD HARD FREEZE FRIDAY MORNING
WHICH INCLUDES THE LOWER DESERTS. BELOW NORMAL TEMPERATURES
CONTINUING THROUGH DECEMBER 9TH.
MORNING PLOTS UP IN ALASKA PLACE A VERY COLD 514DM LOW NEAR
YAKUTAT...WHICH IS THE PRIME SPOT FOR REALLY COLD TEMPERATURES
ACROSS THE EASTERN INTERIOR OF ALASKA. THIS ARCTIC AIR MASS WILL
WORK ITS WAY SOUTH SUNDAY AND MONDAY AS THE UPPER LOW MOVES TO NEAR
SEATTLE MONDAY MORNING.
ON TUESDAY...UPPER TROF DEEPENS TO OUR NW WITH PRESSURE GRADIENT
STARTING TO TIGHTEN...THUS BRINGING SOME AFTERNOON BREEZES TO THE
AREA. WILL SEE AN INCREASE IN MID-LEVEL MOISTURE LATE TUESDAY NIGHT
THAT A FEW LIGHT VALLEY RAIN/MOUNTAIN SNOW SHOWERS COULD DEVELOP.
WEDNESDAY...BREEZY TO LOCALLY WINDY AS UPPER TROF/ASSOCIATED COLD
FRONT EDGES CLOSER TO THE AREA. PRECIPITATION CHANCES IN THE VALLEYS
LESS THAN 30 PERCENT WITH 30%-50% IN THE MOUNTAINS. SNOW LEVEL WILL
BE LOWERING TO 6000 FEET NORTH AND WEST TO 7500 FEET SOUTHEAST.
HIGHS WILL BE 5-12 DEGREES COOLER THAN TUESDAY WITH THE LEAST AMOUNT
OF CHANGE OCCURRING EAST OF TUCSON.
WEDNESDAY NIGHT INTO THURSDAY...SNOW LEVEL CONTINUE TO SLOWLY FALL
AS TROF AXIS PUSHES THROUGH THE STATE. STILL SOME TIMING ISSUES
BETWEEN MODELS WHICH WILL BE RESOLVED OVER THE COMING DAYS. HIGHS ON
THURSDAY 6-10 DEGREES COOLER THAN WEDNESDAY.
THURSDAY NIGHT INTO FRIDAY...AS MENTIONED ABOVE THERE ARE TIMING
DIFFERENCES BETWEEN THE MODELS WITH THE GFS BEING DRY WHILE ECMWF
HOLDING ON TO A BIT MORE MOISTURE AND COMBINED WITH LOWER SNOW
LEVELS...COULD SEE SOME FLAKES AT THE LOWEST ELEVATIONS EAST OF
TUCSON. DEPENDING ON WHICH MODEL IS CORRECT IT WILL BE COLD AS THE
MODIFIED ARCTIC AIR MASS SETTLES IN OVER THE AREA. LOWERED FORECAST
LOWS FOR FRIDAY MORNING SIGNIFICANTLY FROM WHAT I INHERITED AND HAVE
ALL OF SOUTHEAST ARIZONA BELOW FREEZING WITH THE FIRST WIDESPREAD
HARD FREEZE FOR THE LOWER DESERTS POSSIBLE. SOME OF THE HIGHEST
MOUNTAIN SPOTS WILL SEE LOWS IN THE SINGLE DIGITS. HIGHS ON FRIDAY
WILL BE RATHER CHILLY...MAINLY IN THE 50S.
SATURDAY...DRY AND WARMER.
&&
.AVIATION...CONSIDERABLE CLOUDS ABOVE 15K FT WITH SCT-BKN 10K FT
WILL CONTINUE ACROSS THE AREA THROUGH SUNDAY EVENING...OR 02/04Z.
WINDS GENERALLY LESS THAN 10 KTS THROUGH 02/04Z WITH NORMAL DIURNAL
TRENDS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A NEARLY STATIONARY LOW WELL WEST OF THE BAJA
CALIFORNIA COAST WILL PROVIDE DRY CONDITIONS AND CONSIDERABLE CLOUDS
INTO EARLY NEXT WEEK. BY THE MIDDLE OF NEXT WEEK A STRONG TROUGH
WILL DEVELOP ALONG THE WEST COAST. THIS TROUGH WILL CONTINUE TO
DEEPEN INTO THE LATTER PART OF NEXT WEEK FOR A SIGNIFICANT CHANGE
TOWARDS COLD TEMPERATURES AND INCREASED SHOWER ACTIVITY. A SLIGHT
CHANCE OF SHOWERS STARTING LATE TUESDAY WITH INCREASING COVERING
STARTING LATE WEDNESDAY INTO THURSDAY. DECREASING SHOWER COVERAGE ON
FRIDAY AS SNOW LEVELS DROP TO AROUND 4000 FEET. ANTICIPATING THE
STRONGEST SOUTHWEST WINDS OF 15-30 MPH TO OCCUR AHEAD OF THIS TROUGH
AROUND MID WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/GLUECK
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
831 PM EST SAT NOV 30 2013
.UPDATE...
BIG STORY TONIGHT WILL BE THE MOVEMENT AND DEVELOPMENT OF THE LOW
CLOUDS AND FOG. ALREADY HAVE AN AREA OF LOW CLOUDS...CEILINGS
BETWEEN 600 AND 1300 FEET MOVING SOUTHWEST FROM NORTHEAST FLORIDA
INTO THE NATURE COAST. GLOBAL MODELS ARE HINTING AT SOME LOW
CLOUDS AND FOG ACROSS MOST OF THE REGION BY SUNRISE...BUT THE
LATEST HRRR IS GOING GLOOM AND DOOM AND BRINGING LOW CLOUDS...
CEILINGS BELOW 500 FEET...ACROSS MOST OF THE REGION BY SUNRISE
ALONG WITH WIDESPREAD FOG SOME OF WHICH IS DENSE WITH
VISIBILITIES LESS THAN 1/2 MILE. IF THE HRRR IS RIGHT WE WILL END
UP NEEDING A DENSE FOG ADVISORY FOR MUCH OF THE AREA LATE TONIGHT
INTO EARLY SUNDAY MORNING. THEN DURING SUNDAY THE LOW CLOUDS AND
FOG SHOULD LIFT AND DISSIPATE BY MIDDAY...BUT WE WILL STILL HAVE
MOISTURE TRAPPED BELOW THE INVERSION LEADING TO MORE SCATTERED
TO BROKEN STRATOCUMULUS/ALTOCUMULUS. HAVE ALREADY UPDATED THE
GRIDS TO INCLUDE MORE CLOUDS AND FOG FOR TONIGHT INTO SUNDAY
MORNING AND WILL UPDATE THE ZONES SHORTLY. OTHERWISE...REMAINDER
OF FORECAST LOOKS OK AT THIS TIME.
&&
.AVIATION...
AREA OF LOW CLOUDS OVER NORTHEAST FLORIDA WILL EXPAND WEST AND
SOUTH OVERNIGHT. HAVE FAIRLY HIGH CONFIDENCE IN MVFR/IFR CEILINGS
BEGINNING AROUND 03Z OR SO MAINLY TPA...PIE AND LAL. WHILE LIFR
CEILINGS ARE POSSIBLE FOR A BRIEF TIME TOWARD SUNRISE...CONFIDENCE
TOO LOW TO INCLUDE IN TAFS AT THIS TIME. EXPECT LESS COVERAGE OF
LOW CLOUDS AT SRQ...PGD...FMY AND RSW...BUT WILL CONTINUE TO
MONITOR. PGD COULD SEE IFR/LIFR VISIBILITIES IN GROUND FOG
BEFORE SUNRISE.
&&
.MARINE...
NORTHEAST WINDS WILL BEGIN TO DIMINISH LATE TONIGHT INTO SUNDAY
AND THEN SHIFT TO NORTHERLY SUNDAY AFTERNOON. WINDS WILL CONTINUE
TO BACK TO NORTHWEST TO WEST ON MONDAY AS THE HIGH PRESSURE TO THE
NORTHEAST WEAKENS AND IS REPLACED BY DEVELOPING LOW PRESSURE OFF
THE SOUTHEAST U.S. COAST. PRESENT MARINE FORECAST LOOKS OK WITH NO
MAJOR CHANGES PLANNED FOR LATE EVENING FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 59 76 61 74 / 0 10 10 20
FMY 60 79 61 77 / 0 10 10 20
GIF 57 78 59 75 / 5 10 10 20
SRQ 59 77 60 74 / 0 10 10 20
BKV 53 76 54 74 / 0 10 10 20
SPG 62 75 63 73 / 0 10 10 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...69/CLOSE
AVIATION...63/JILLSON
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1135 PM CST THU NOV 28 2013
.UPDATE...
ISSUED AT 917 PM CST THU NOV 28 2013
AN UPDATE WAS JUST SENT TO LOWER TEMPERATURES 2 OR 3 DEGREES OVER
THE NORTHERN HALF OF THE FORECAST AREA. AT 03Z OBSERVED TEMPS WERE
WITHIN A FEW DEGREES OF FORECAST MINS AT SEVERAL SITES NORTH OF I80.
LIGHT AND VARIABLE WINDS AND CLEAR SKIES THE REST OF THE NIGHT
WILL ALLOW TEMPS TO CONTINUE COOLING...REACHING THE SINGLE DIGITS
TO AROUND 10 BY SUNRISE.
&&
.SYNOPSIS...
ISSUED AT 218 PM CST THU NOV 28 2013
A WEAK SURFACE LOW MOVED EASTWARD INTO SOUTHERN LAKE MICHIGAN
DURING THE DAY ON THURSDAY WITH A COLD FRONT STRETCHING SOUTHWESTWARD
TO KSTL TO KJLN IN SOUTHWEST MISSOURI. SURFACE HIGH SAT OVER
EASTERN NORTH DAKOTA. STRATUS ALONG THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE HAS SLOWLY DISSIPATED THROUGH THE DAY. TEMPERATURES
WERE IN THE UPPER 20S IN NORTHWEST ILLINOIS TO THE LOWER 40S IN
WEST CENTRAL ILLINOIS.
A CHANGE IN THE 500 HPA PATTERN WILL OCCUR OVER
THE NEXT SEVEN DAYS AS WE GO FROM THE CURRENT NORTHWEST FLOW ALOFT
TO A MORE ZONAL FLOW WHICH WILL CONTINUE INTO EARLY NEXT WEEK.
THIS WILL RESULT IN SLOWLY MODERATING TEMPERATURES AS THE COLD AIR
OF THE LAST WEEK RETREATS NORTHWARD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE NAM/RAP BEING AN
OUTLIER WITH LOW LEVEL MOISTURE IN PLACE ACROSS THE REGION. THE
MAIN FORECAST CONCERNS WILL BE THE POTENTIAL FOR CLOUD COVER
OVERNIGHT INTO FRIDAY AS WELL AS TEMPERATURES ON FRIDAY.
HIGH PRESSURE IS FORECAST TO BUILD SOUTHEASTWARD OVERNIGHT AND BE
CENTERED ALONG THE IOWA AND ILLINOIS BORDER BY 12 UTC ON FRIDAY. AN
EXTENSIVE STRATUS DECK DEVELOPED ON THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE THIS MORNING WITH A STRONG INVERSION IN PLACE
ACROSS THE UPPER MIDWEST AND NORTHERN PLAINS. THE 12 UTC SOUNDINGS
AT KBIS AND KABR SHOWED EXTENSIVE LOW LEVEL MOISTURE IN PLACE. THE
ECMWF...GFS... AND GEM CONTINUE TO SHOW A DRIER INVERSION IN PLACE
ACROSS THE REGION OVERNIGHT WHILE THE NAM AND RAP SHOW MORE
MOISTURE IN THE LOWER LEVELS OF THE ATMOSPHERE BUT NOT TO THE
EXTENT THAT EXISTED AT KBIS AND KABR THIS MORNING. THEREFORE I AM
NOT ANTICIPATING THE FORMATION OF NEW STRATUS TONIGHT SO GOING
WITH CLEAR SKIES TONIGHT. A GOOD RADIATIONAL COOLING NIGHT AND
EXPECT TEMPERATURES TO FALL QUICKLY THIS EVENING.
HIGH PRESSURE IS FORECAST TO SHIFT EASTWARD DURING THE DAY ON
FRIDAY WITH WINDS VEERING TO THE SOUTHEAST DURING THE AFTERNOON HOURS.
850 HPA TEMPERATURES WARM FROM -4 TO -10*C TODAY TO 0 TO -4*C ON
FRIDAY. HAVE WARMED TEMPERATURES UP BY A COUPLE OF DEGREES BUT MID
LEVEL CLOUDINESS WILL BE ON THE INCREASE TOMORROW AHEAD OF ANOTHER
WAVE THAT WILL ARRIVE ON SATURDAY. THE INCREASING CLOUDS MAY HELP
TO KEEP TEMPERATURES FROM WARMING AS THEY DID TODAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
FRIDAY NIGHT...WEAK NORTHERN STREAM CLIPPER WILL CONTINUE MOVING TO
GREAT LAKES BY SATURDAY MORNING. OVERNIGHT LOW TEMPERATURES WILL BE
IN THE 20S.
SATURDAY AND SUNDAY...TEMPERATURES WILL RANGE NEAR OR SLIGHTLY ABOVE
NORMAL ON SATURDAY BEFORE A WEAK SURFACE TROF CROSSES THE AREA
SWITCHING THE WIND TO THE WEST NORTHWEST LATE IN THE DAY. WITH
LIMITED MOISTURE THIS TROF PASSAGE WILL BE DRY. ON SUNDAY...WEAK
COLD AIR ADVECTION BEHIND THE TROF PASSAGE WILL PRODUCE LOW
TEMPERATURES IN THE IN 20S ON SATURDAY NIGHT WITH HIGHS IN THE MID
30S ACROSS THE NORTHERN THIRD OF THE FORECAST AREA WITH HIGHS IN THE
40S OVER THE SOUTH.
MONDAY THROUGH WEDNESDAY...LATEST MEDIUM RANGE MODEL SOLUTIONS
CONTINUE TO DIVERGE BUT THERE IS OVERALL AGREEMENT IN DEVELOPING A
DEEP TROF ACROSS THE WESTERN UNITED STATES BY MID WEEK. THE ENERGETIC
SYSTEM CURRENTLY DIVING SOUTH ALONG THE WEST COAST WILL BEGIN A
PERIOD OF ACTIVE WEATHER FOR THE MIDWEST. THE 12Z GFS KEEPS THE
FORECAST AREA MAINLY DRY THROUGH TUESDAY. HOWEVER...THE 12Z ECMWF IS
FASTER AND BRINGS PRECIPITATION INTO THE REGION ON MONDAY. IN EITHER
CASE MOISTURE ADVECTION FROM THE GULF OF MEXICO AHEAD OF THE SURFACE
LOW WILL BREAK OUT PRECIPITATION EITHER MONDAY OR TUESDAY. THE
PRECIPITATION COULD FALL AS A MIXTURE OF RAIN AND SNOW.
THURSDAY AND FRIDAY...CONFIDENCE IS LOW AS MODEL SOLUTIONS SHOW
MAJOR DISCREPANCIES. THE 12Z RUN OF THE ECMWF PROGS A SURFACE
LOW TO DEVELOP OVER THE CENTRAL ROCKIES AND TRACK NORTHWEST OF IOWA
ON THURSDAY. IF THIS TRACK IS CORRECT WARM AIR ADVECTION AHEAD OF
THIS LOW WOULD PRODUCE A RAIN OR RAIN/SNOW MIX TURNING TO ALL RAIN
WITH A SNOW STORM OCCURRING OVER WESTERN IOWA AND THE NORTHERN
PLAINS. ON THE OTHER HAND THE 12Z RUN OF THE GFS TRACKS THE SURFACE
LOW FURTHER SOUTHEAST AND PROGS IT TO MOVE ACROSS MISSOURI INTO
NORTHERN ILLINOIS/INDIANA BY FRIDAY. IF THE GFS SOLUTION IS CORRECT
THERMAL PROFILES WOULD SUPPORT AN ALL SNOW EVENT LATE NEXT WEEK.
HOWEVER I MUST STRONGLY REITERATE FORECAST CONFIDENCE IS LOW.&&
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM CST THU NOV 28 2013
VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY EVENING. CLEAR SKIES
AND LIGHT WINDS WILL REMAIN OVER THE AREA TONIGHT AS HIGH PRESSURE
DRIFTS EAST THROUGH THE REGION. FRIDAY...WITH THE HIGH TO THE
EAST...WINDS WILL PICKUP OUT OF THE SOUTHEAST WITH HIGH CLOUDS
OVER SPREADING THE AREA DURING THE AFTERNOON AND EVENING.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...DLF
SYNOPSIS...COUSINS
SHORT TERM...COUSINS
LONG TERM...KUHL
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
941 PM EST SAT NOV 30 2013
.SYNOPSIS...
A WEAK FRONTAL SYSTEM WILL INCREASE CLOUDS ON SUNDAY WITH A
SLIGHT CHANCE OF PRECIPITATION LATE IN THE DAY AND INTO MONDAY.
ANOTHER FRONT WILL GIVE US A SMALL CHANCE OF A SHOWER OR SPRINKLE
ON WEDNESDAY. THE BEST CHANCE OF RAIN THIS WEEK WILL COME LATE ON
THURSDAY INTO EARLY FRIDAY ALONG WITH MILDER TEMPERATURES.
&&
.NEAR TERM /THROUGH SUNDAY/...
940 PM UPDATE...
TEMPERATURES WERE PLUMMETING EARLIER THIS EVENING WITH LIGHT
WINDS AND COMPLETELY CLEAR SKIES. HOWEVER...SWATH OF CI/HIGH AC
HALTED QUICK DROP AND ACTUALLY SOME PLACES (KBTP) WENT UP A COUPLE
OF DEGREES. HRRR STILL ADVERTISING A LITTLE SLOWER CLOUD ADVECTION
AND WINDS IN SEVERAL SPOTS STILL LIKELY TO DECOUPLE. WITH YET
ANOTHER CLEAR AREA LIKELY TO TRANSLATE THE REGION...HAVE
COMPROMISED ON MINS. DROPPING THEM FROM ORIGINAL LEVELS
(ESPECIALLY OVER SNOW COVER) BUT ALSO TEMPERING WITH THE CLOUD
COVER WHICH WILL LIKELY MOVE IN TOWARD MORNING.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
ONE THING SUMMARIZES THIS PERIOD...CLOUDY. SOUNDINGS AND TIME
HEIGHTS SHOW RH NEAR 100% IN THE LOWEST 8KFT. LITTLE CHANGE NEEDED
TO GRIDDED DATA SET AS CONTINUITY EXISTS FROM NCEP SUITE. DID BRING
SCHC POPS FARTHER S SUN NGT AS S/W TROUGH IS PROGGED TO CROSS PA
OPPOSE TO STAYING N ALONG THE LAKE. THIS COULD YIELD AN ISOLD
RW/SW. CLOUD TOP TEMPS HAVE INCREASED SO POSSIBILITY OF RA OR SN
EXISTS RATHER THAN DZ / FZDZ. NOT A LOT OF FORCING PRESENT SO QPF
AMOUNTS WILL BE ON THE ORDER A FEW HUNDREDTHS. BEST SHOT FOR
MEASURABLE PCPN ARRIVES MON NGT INTO TUE WHEN NEGATIVELY TILTED TROF
AXIS PASSES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS:
- TEMPS AROUND 5-10F ABOVE NORMAL WED - FRI
- SOGGY WEATHER THUR - FRI
- LOTS OF UNCERTAINTY FRI NGT - SAT
LONG RANGE NUMERICAL WEATHER SUITE STILL HAS A LOT OF SPREAD IN
DETAILS IN THE FIRST PART THEN CONVERGE NICELY FOR THE MAIN SYNOPTIC
SYSTEM. CONSISTENCY DOES NOT LAST LONG AS THEY DIVERGE AT THE END.
GREATEST CERTAINTY IN THE FORECAST RESIDES THUR NGT INTO FRI WITH
INCREASED UNCERTAINTY AT THE BOOKENDS /WED AND NEXT SAT/.
ECMWF CONTINUES WITH GOOD RUN TO RUN CONSISTENCY VIA DPROG/DT VERSUS
GFS. ECMWF MAINTAINS A STRONG ERN CONUS RIDGE DUE TO STRONGER
CYCLONE ACROSS SRN CANADA. THIS CORRELATES WELL GIVEN ANOMALOUS
DEVIATIONS IN H5 HGTS AND H8 TEMPS ILLUSTRATED BY GEFS. MUCH LIKE
YESTERDAY/S FORECAST...IT WAS CONSTRUCTED FROM ECMWF. PATTERN/S
AMPLITUDE DOES NOT OWE ITSELF TO GFS HEIGHT FIELD RELATIVELY FLAT
AND TRANSITORY AND AS WPC DISCUSSED IT WAS DISCARDED.
FOR WED...KEPT THINGS DRY LIKE ONGOING FORECAST WITH BAROCLINIC ZONE
ACROSS IND /DESPITE GFS SHOWING FROPA IN WRN PA/. WARM FRONT
CROSSES DURING THE MORNING ALLOWING SUNSHINE AND WARMER WEATHER COME
AFTN. DEPENDING HOW FAR N BOUNDARY GETS COULD SEE A 15F SPREAD FOR
MAXT...FROM L40S DUJ-FKL TO M50S IN FAIRMONT. COLD FRONT APPROACHES
WED NGT SO POPS INC FM W TO E DURING THE OVERNIGHT HRS.
LATTER PART OF THE WORK WEEK GFS HAS COME AROUND TO ECMWF THINKING
WITH A SFC LOW RIDING NE ALONG DISSIPATED COLD FRONT THAT CROSSED
WED NGT. PLENTY OF MOISTURE SURGES INTO THE OHIO VALLEY CREATING
PWATS VALUES AROUND AN INCH...WHICH IS TWO STANDARD DEVIATIONS ABOVE
NORMAL. POPS WERE INCREASED TO LKLY THUR - FRI WHICH CORRESPONDS
WITH STATISTICAL GUIDANCE. RAINFALL AMOUNTS STILL LOOK TO BE
HIGHEST ALONG AND JUST WEST OF THE MOUNTAINS WHERE CLOSE TO AN INCH
COULD FALL. ECNTRL OH E INTO FAR WRN PA SHOULD SEE LESS...ROUGHLY
1/2 TO 3/4 OF AN INCH. FRI NGT INTO SAT MODELS DIVERGE ONCE AGAIN
WITH GFS BLOWING FRONT THROUGH AND BUILDING IN HIGH PRESSURE GIVEN
LESS AMPLIFIED PATTERN. ECMWF IS SLOWER WITH EXODUS OF FRONT.
THERE IS A POTENTIAL FOR A SHORT PERIOD OF SNOW BEFORE BOUNDARY
VACATES SAT MRNG PER ECMWF GIVEN LLVL THERMAL PROFILES...BUT NOTHING
SIGNIFICANT. ANY SNOW ON THE BACKSIDE FROM GFS WILL BE WITH UPSLOPE
/ LAKE ENHANCED AS COLD AIR INVADES FROM THE W. GREAT LAKES WILL
MODIFY AIRMASS SO ARCTIC OUTBREAK THAT IS BEING ADVERTISED IN THE
PLAINS THIS WEEK...WON`T BE AS BAD THE TIME IT GETS HERE.
NONETHELESS...STILL EXPECT TEMPS TO BE BELOW NORMAL NEXT WEEKEND.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
SKIES CLEARING WITH WEAK FRONT APPROACHING REGION ON SUNDAY.
INCREASED CLOUDS TOWARD MORNING BUT STILL VFR. MOISTURE AT A
PREMIUM WITH FRONT AND ONLY SLIGHT CHANCE PRECIPITATION. DID NOT
INCLUDE IN TAFS. WINDS LIGHT OVERNIGHT WITH SE 5 TO 10 ACROSS
NORTH BECOMING SOUTHERLY AND SW ON SUNDAY.
.OUTLOOK.../00Z MONDAY THROUGH THURSDAY/...
TUESDAY SOME REMNANT CLOUDS AND POSSIBLE SPRINKLE OR FLURRIES
ACROSS NORTH. WEAK HIGH PRESSURE FOR WEDNESDAY. ANOTHER WEAK FRONT
APPROACHES FOR THURSDAY WITH POSSIBLE SCATTERED MVFR.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
339 PM EST FRI NOV 29 2013
.SYNOPSIS...
A GRADUAL WARMING TREND THE COMING DAYS BACK TO NORMAL LEVELS. THE
NEXT FRONT CROSSES SUNDAY...WITH ANY RAIN OR SNOW CONFINE TO
AREAS ALONG AND NORTH OF INTERSTATE 80. LOTS OF CLOUDS ARE
FORECASTED FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AFTER A BRIEF CLEARING...MID LEVEL CLOUD COVERAGE WILL INCREASE
THROUGH THE AFTERNOON AS FLOW ALOFT TURNS NORTHWEST BEHIND THE
SHORTWAVE THAT PASSED OVER THIS MORNING. HAVE ADJUSTED
TEMPERATURES SLIGHTLY UPWARDS BASED ON LATEST OBS
TRENDS...HOWEVER...DAYTIME MAX HIGHS ARE STILL EXPECTED TO BE
APPROXIMATELY 10 DEGREES BELOW CLIMO NORMS TODAY. TONIGHT WINDS
WILL TURN SOUTHWESTERLY...AND THE INCREASED WAA WILL INITIATE A
WARMING TREND IN TEMPERATURES THROUGH THE REMAINDER OF THE WEEKEND.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
HIGH PRESSURE CONTINUES TO RETREAT INTO NEW ENGLAND SAT
NGT...HOWEVER RETURN FLOW ALLOWS FOR A WARMER NIGHT WITH SWRLY
WINDS OUT AHEAD. OVERALL MODELS ARE IN GOOD AGREEMENT WITH THE
NEXT WEATHER SYSTEM SUN - MON NIGHT. BOTH DEPICT A FULL LATITUDE
TROUGH ACROSS THE EASTERN CONUS...BUT LITTLE IN THE WAY OF ANY
BAROCLINICTY AT THE SFC. ALL OF THE ENERGY RESIDES WITH THE
CYCLONE TRACKING OFF THE ERN SEABOARD. UPSTAIRS THERE ARE PASSING
S/W TROUGHS DURING THIS PERIOD THAT WILL YIELD LIGHT QPF. H5
TROUGH BECOMES NEGATIVELY TILED AS IT SWEEPS THROUGH MONDAY
NIGHT...BUT WITH THE LACK OF AGEOSTROPHIC DIVERGENCE AT H2 AND
5-10KTS OF LLVL CONV...ONLY LIGHT PCPN EXPECTED. CONTINUED THEME
OF HIGHLIGHTING AREAS ALONG AND N OF I-80 FOR MEASURABLE QPF
SUNDAY INTO SUNDAY NIGHT. THERMAL PROFILES ILLUSTRATE POTENTIAL
FOR A RA/SN MIX. HIGH PROBABILITY OF ALL SNOW THE CLOSER TO LAKE
ERIE AS COLUMN IS COLDER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HIGHLIGHTS:
- SLOW WARMING TREND CONTINUES
- ABOVE NORMAL TEMPS BY THE END OF NEXT WEEK
- STRONG LOW PRESSURE PASSES THUR - FRI
FORECAST CONFIDENCE IS ABOVE AVERAGE FOR THE FIRST TWO DAYS OF
THE LONG RANGE THEN LOWERS. TRANSITORY MID LVL RIDGE CROSSES MID WEEK
ALLOWING TEMPS TO WARM INTO THE 40S MELTING ANY LEFTOVER SNOW
PACK.
LATTER PART OF THE WEEK BOTH OPERATIONAL RUNS OF ECMWF AND GFS
SHOW A GOOD SHOT AT RAIN WITH LOW PRESSURE TRAVELING ALONG THE
MTNS. THIS TRACK WHICH IS FURTHER SUPPORTED BY THEIR RESPECTIVE
ENSEMBLE MEANS PLACE US ON THE WARM SIDE OF THE SYSTEM. THE
CHALLENGE IS TIMING AND IF A SECOND WAVE RIDES ALONG THE BOUNDARY
AS MID LVL FLOW BECOMES PARALLEL TO THE FRONT. STRONG ISENTROPIC
UPGLIDE ON 290-300K WITH WINDS INTERESTING THETA SFCS AT RIGHT
ANGLES. SPECIFIC HUMIDITY VALUES PUSH 4-5 GKG-1 WHICH IS ABOVE
NORMAL THIS TIME OF YEAR. GEFS PLUME DIAGRAMS SHOW POTENTIAL FOR
0.50 TO 1.25 INCHES OF RAIN WITH VERY LITTLE SNOW ON THE BACK
SIDE. THIS IS NOTHING THAT WOULD LEAD TO HIGH WATER DUE TO ALL THE
SNOW HAS MELTED AND WE WILL BE DRY THE DAYS LEADING UP.
A LOT OF SPREAD EXISTS AFTER THE COLD FRONT COMES THROUGH. ECMWF IS
STRONGER WITH UPSTREAM RIDGE AXIS THEREBY HAVING ANOTHER WAVE OF
LOW PRESSURE PASSING FRIDAY W OF THE MTNS. GFS IS WEAKER WITH RIDGE
THUS HAVING LOW PRESSURE PASS TO OUR SE. GIVEN GUIDANCE SPREAD
FROM MOS IS WELL INTO THE 60S ROLLED WITH LKLY POPS NEXT THUR AND
FRI.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
NO WIDESPREAD AREAS OF IFR WEATHER EXPECTED. BRIEF MVFR
RESTRICTIONS ARE POSSIBLE WITH THE NEXT WEATHER SYSTEM SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...98
NEAR TERM...88
SHORT TERM...98
LONG TERM...98
AVIATION...88/98
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1226 PM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AFTER A BRIEF CLEARING...MID LEVEL CLOUD COVERAGE WILL INCREASE
THROUGH THE AFTERNOON AS FLOW ALOFT TURNS NORTHWEST BEHIND THE
SHORTWAVE THAT PASSED OVER THIS MORNING. HAVE ADJUSTED
TEMPERATURES SLIGHTLY UPWARDS BASED ON LATEST OBS
TRENDS...HOWEVER...DAYTIME MAX HIGHS ARE STILL EXPECTED TO BE
APPROXIMATELY 10 DEGREES BELOW CLIMO NORMS TODAY. TONIGHT WINDS
WILL TURN SOUTHWESTERLY...AND THE INCREASED WAA WILL INITIATE A
WARMING TREND IN TEMPERATURES THROUGH THE REMAINDER OF THE WEEKEND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
CLOUD COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS
SATURDAY IN ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON
SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
915 AM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY CHANGES NEEDED FOR THE MID MORNING UPDATE WERE TWEAKS TO HOURLY
TRENDS OF CLDS AND TEMPS.
PREVIOUS...
COLD AIR REMAINS OVER THE AREA TODAY. LATEST MODEL SOUNDINGS AND
HIRES SOLUTIONS ARE SHOWING CLOUDS DECREASING THIS MORNING FROM
SOUTHWEST TO NORTHEAST...AS ATMOSPHERE TEMPORALLY DRIES OUT.
HOWEVER ANOTHER PUSH OF COLDER AIR THIS AFTERNOON WILL PROMOTE
CLOUD REDEVELOPMENT.
TEMPS AGAIN...WELL BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WAA WILL BE ON THE INCREASE TONIGHT AND SATURDAY WHICH WILL
RESULT IN A WARMING TREND IN TEMPERATURES SATURDAY. CLOUD
COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS SATURDAY IN
ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
632 AM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY CHANGES NEEDED FOR THE NR DAWN UPDATE WERE TWEAKS TO HOURLY
TRENDS OF CLDS AND TEMPS.
PREVIOUS...
COLD AIR REMAINS OVER THE AREA TODAY. LATEST MODEL SOUNDINGS AND
HIRES SOLUTIONS ARE SHOWING CLOUDS DECREASING THIS MORNING FROM
SOUTHWEST TO NORTHEAST...AS ATMOSPHERE TEMPORALLY DRIES OUT.
HOWEVER ANOTHER PUSH OF COLDER AIR THIS AFTERNOON WILL PROMOTE
CLOUD REDEVELOPMENT.
TEMPS AGAIN...WELL BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WAA WILL BE ON THE INCREASE TONIGHT AND SATURDAY WHICH WILL
RESULT IN A WARMING TREND IN TEMPERATURES SATURDAY. CLOUD
COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS SATURDAY IN
ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/22
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
401 AM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD AIR REMAINS OVER THE AREA TODAY. LATEST MODEL SOUNDINGS AND
HIRES SOLUTIONS ARE SHOWING CLOUDS DECREASING THIS MORNING FROM
SOUTHWEST TO NORTHEAST...AS ATMOSPHERE TEMPORALLY DRIES OUT.
HOWEVER ANOTHER PUSH OF COLDER AIR THIS AFTERNOON WILL PROMOTE
CLOUD REDEVELOPMENT.
TEMPS AGAIN...WELL BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WAA WILL BE ON THE INCREASE TONIGHT AND SATURDAY WHICH WILL
RESULT IN A WARMING TREND IN TEMPERATURES SATURDAY. CLOUD
COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS SATURDAY IN
ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY.
BLDG HIGH PRES WL SPPRT LTR IN THE DAY AND FOR THE RMNDR OF THE TAF
PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
916 PM EST SAT NOV 30 2013
.UPDATE...
CURRENT CONDITIONS ARE CERTAINLY SUPPORTIVE OF FOLLOWING THE
PREVIOUS FORECASTS THOUGHTS ON LOWER CHANCES OF PRECIPITATION THAN
WHAT THE 12Z AND 18Z MODELS ARE SUGGESTING. NEARLY ALL OF THE
RADAR RETURNS OVER LOWER MICHIGAN ARE VIRGA. LATEST RUC RUNS ARE
MORE SUPPORTIVE OF A DRIER OVERNIGHT AND ARE REALLY IN LINE WITH
THE CURRENT FORECAST POPS...CLOUDS AND QPF. 00Z SOUNDINGS AND THE
LATEST RUC SOUNDINGS SUGGEST THAT IT WILL TAKE SOME TIME TO
SATURATE THE LAYER BETWEEN 3K AND 6K FEET. WHILE THERE IS SOME
MOISTURE ALONG THE FRONT BELOW 3K FEET...IT IS REALLY ABOVE THIS
THAT DRY AIR REMAINS IN PLACE TO LIMIT PRECIP. THE OTHER ITEM THAT
SHOWS WELL IN THE SOUNDINGS IS THAT THE FREEZING LEVEL WILL LIKELY
BE 1000 TO 2000 FEET ABOVE THE SURFACE WHEN WE FIRST SATURATE. ANY
PRECIP THAT HAS FALLEN ACROSS NRN LOWER THIS EVENING HAS BEEN
RAIN. THEREFORE WILL BRING IN A MIX OF RAIN...AT LEAST AT THE
START...FOR ANY PLACE THE DOES GET SOME PRECIP OVERNIGHT.
WILL RAISE TEMPS JUST A BIT OVERNIGHT DUE TO THE COMBINATION OF
THE CLOUDS AND SOUTHERLY WIND AHEAD OF THE COLD FRONT. TEMPS WILL
EVENTUALLY REACH THEIR FORECAST LOWS WITH THE FRONTAL PASSAGE OR
WITH THE EVAPORATE COOLING. THE EXCEPTION WILL BE IN THE FAR
SOUTH OF THE FORECAST AREA WHERE MOSTLY CLEAR SKIES ARE ALLOWING
TEMPS TO FALL.
&&
.AVIATION...ISSUED 623 PM EST SAT NOV 30 2013
//DISCUSSION...
WILL CONTINUE THE TREND OF A SLOWER PROGRESSION OF THE LOW LEVEL
MOISTURE THAT THE MODELS DEPICT. HOWEVER WITH THE LATEST MODEL RUNS
AND THE EVIDENCE OF SOME LOWER MVFR CIGS ACROSS THE U.P. AND
NORTHERN LOWER...DID MOVE THE LOWER CIGS UP IN TIME FOR THE TAF
SITES. LIMITED PRECIPITATION MENTION TO KMBS...09-13Z...WHERE DEEPER
MIDLEVEL MOISTURE CLIPS THE SAGINAW VALLEY/THUMB. WHILE THEIR MAY BE
A BRIEF PERIOD OF RAIN AT THE START LIKE AT PLN THIS EVENING...DRY
AND COLD AIRMASS SHOULD ALLOW WET BULBING TO SUPPORT SNOWFLAKES AS
THE DOMINANT HYDROMETEOR TYPE. KEPT VISIBILITY OBSTRUCTIONS FROM -SN
IN THE MVFR RANGE. HIGH CONFIDENCE IN MVFR CLOUDS AFTER PASSAGE OF
THE SURFACE FRONT...WHEN CLOUDS WILL THEN PERSIST FOR A LONG
DURATION.
FOR DTW...DRY AIRMASS PRE COLD FRONT TONIGHT WILL KEEP CLOUDS ABOVE
5000 FT. MODELS APPEAR OVERDONE ON LOW LEVEL SATURATION LATE
TONIGHT/EARLY TOMORROW MORNING. MVFR CLOUD WILL THEN SETTLE OVER THE
TAF SITE DURING SUNDAY MORNING IN RESPONSE TO LOW LEVEL COLD AIR
ADVECTION.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILING HEIGHTS BELOW 5000 FT PRIOR TO 12Z
SUNDAY. HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET BEGINNING SUNDAY
MORNING.
&&
.PREV DISCUSSION...ISSUED 319 PM EST SAT NOV 30 2013
SHORT TERM...TONIGHT
A THERMAL WAVE DIGGING SOUTHEASTWARD ALONG THE TRAILING EDGE OF NE
NORTH AMERICAN UPPER LEVEL TROUGH WILL BE THE WEATHER AFFECTING THE
CENTRAL GREAT LAKES TONIGHT. THE CYCLONIC VORTICITY ENERGY
ASSOCIATED WITH THE SHORT WAVELENGTH THERMAL RIDGE IS FRAGMENTED
WITH THE INITIAL SHORTWAVE DAMPENING WHILE IT PUSHES EAST OF LAKE
SUPERIOR THIS AFTERNOON. A SECOND SHORTWAVE IS NOW SLIDING THROUGH
THE MINNESOTA ARROWHEAD AND INTO THE FAR WESTERN LAKE SUPERIOR BASIN
TAKING OVER WITH TIME. THIS SHORTWAVE WILL PROVIDE A NECESSARY
FORCING COMPONENT AFTER 9Z OVER THE FAR NORTHERN CWA WHICH SHOULD
FINALLY ALLOW PRECIPITATION TO FALL. OTHERWISE THE MIX OF DYNAMICS
SUPPORTIVE OF ASCENT IS LIMITED. ANALYSIS OF 285K SYSTEM RELATIVE
ISENTROPIC ASCENT IS VERY UNINSPIRING DESPITE SOME LINKAGE OF RIGHT
ENTRANCE REGION DYNAMICS ALOFT WITH 850-700MB DEFORMATION. THE
DEFORMATION IS MODELED TO BE ASSOCIATED WITH THE CONVERGENCE FEATURE
OF THE FRONT. EXPECT THIS FORCING TO STRIPE FOR A VERY LIMITED TIME
FROM WEST TO EAST NORTHEAST...PRIMARILY ACROSS THE FAR NORTHERN
COUNTIES. WET BULB AND OFFERED BUFKIT SOUNDINGS SUPPORT AN ALL SNOW
EVENT...TRENDED TO ALL SNOWFLAKES. A DUSTING WILL BE POSSIBLE NORTH
AFTER 8Z...PERHAPS A HALF TO 1 INCH IN THE NORTHERN THUMB.
LONG TERM...SUNDAY THROUGH NEXT SATURDAY
MID LEVEL ENERGY IS FORECAST TO RAPIDLY SHEER TO THE EAST OF THE
AREA LATE SUNDAY MORNING. THE 12Z MODEL SUITE ALL SUGGEST THE
ASSOCIATED MID LEVEL ASCENT WILL RESIDE ALONG THE 1-69 CORRIDOR INTO
THE THUMB REGION BY 12Z BEFORE QUICKLY WANING BY NOON. BOTH NAM AND
GFS APPEAR TOO AGRESSIVE IN MOISTENING THE LOW LEVELS...SUGGESTING
THAT WET BULB COOLING MAY BE STRONG ENOUGH TO KEEP ANY LINGERING
MORNING PRECIP AS LIGHT SNOW. UPSTREAM OBSERVATIONS DO HOWEVER
SUPPORT MODEL SOLUTIONS WHICH BRING A POST FRONTAL LOW STRATUS DECK
INTO THE AREA FOLLOWING THE PASSAGE OF A WEAK SURFACE COLD FRONT.
THESE LOW CLOUDS ARE EXPECTED TO ENVELOPE THE TRI CITIES AND THUMB
BY DAYBREAK...THEN OVERSPREAD METRO DETROIT EARLY SUN AFTERNOON.
OVERALL WEAK POST FRONTAL COLD AIR ADVECTION WILL SUPPORT SUN MAX
TEMPS IN THE MID/UPPER 30S ACROSS THE NORTH AND LOW 40S SOUTH OF THE
I-96/696 CORRIDOR.
THE DEPTH OF THE POST FRONTAL COLD AIR SUN AFTERNOON WILL BE GREATER
OVER LAKE HURON...WHICH WILL RESULT IN A DEEPENING CONVECTIVE DEPTH
OVER THE LAKE. MODEL SOLUTIONS SUGGEST A GOOD RESPONSE OFF THE
LAKE...ENOUGH TO SUPPORT A CHANCE OF SNOW SHOWERS OVER THE THUMB SUN
AFTERNOON INTO SUNDAY EVENING AS THE FLOW TURNS TOWARD THE NE. THE
EXPECTED DEGREE OF VARIABILITY IN THE LOW LEVEL WIND DIRECTION DOES
NOT SUPPORT A PROLONGED CONVERGENT BAND...SO FORECAST ACCUMS WILL BE
KEPT MINIMAL. MID LEVEL SUBSIDENCE WILL LOWER INVERSION HEIGHTS SUN
NIGHT AND WILL MAINTAIN THE LOW STRATUS OVER THE REGION. CONTINUED
LOW LEVEL MOISTURE FLUX UNDER THE NE FLOW MAY HOWEVER SUPPORT SOME
DRIZZLE SUN NIGHT INTO MON MORNING OVER A GOOD PORTION OF SE MI.
CONFIDENCE IS NOT QUITE HIGH ENOUGH TO ADD DRIZZLE TO THE
ZONE/GRIDS AT THIS POINT...BUT IS SOMETHING LATER SHIFTS WILL
HAVE TO MONITOR. AMPLE LOW CLOUDS AND WEAK LOW LEVEL THERMAL
ADVECTION IS LIKELY TO HOLD TEMPS IN THE 30S SUN NIGHT INTO MON
MORNING.
A LOW AMPLITUDE MID LEVEL TROUGH IS FORECAST TO TRAVERSE THE OHIO
VALLEY ON MONDAY. DESPITE THE OVERALL WEAK FORCING WITH THIS
FEATURE...MODEL SOLUTIONS DO SUGGEST A HEALTHY SURGE OF MID LEVEL
MOISTURE INTO SRN MI. THIS COUPLED WITH THE EXPECTED STRATUS AND
WEAK LARGE SCALE ASCENT MAY BE ABLE TO GENERATE A FEW LIGHT SNOW
AND/OR RAIN SHOWERS.
SOUTHEAST MICHIGAN CONTINUES TO BE ON A ROLLER COASTER AS FAR AS
TEMPERATURES ARE CONCERNED WITH TEMPS WARMING THROUGH THURSDAY
BEFORE COOLING OFF BY THE WEEKEND. UPPER LEVEL RIDGE WILL WORK INTO
THE AREA TUESDAY HELPING TO KEEP THINGS ON THE DRIER SIDE. PRECIP
CHANCES START TO INCREASE WEDNESDAY AS A LOW TRAVERSES OVER THE
NORTHERN GREAT LAKES. SOUTHERLY FLOW OUT AHEAD OF THIS SYSTEM WILL
HELP TO BRING IN MOISTURE AND WARMER AIR. PRECIP TYPE WILL LIKELY
START OFF AS SNOW BEFORE QUICKLY TRANSITIONING TO ALL RAIN AS
WARMER TEMPS OVERSPREAD THE AREA. BETTER CHANCE FOR MEASURABLE
PRECIP WILL COME THURSDAY INTO FRIDAY AS ANOTHER LOW DEVELOPS AND
MOVES TOWARDS THE GREAT LAKES. CURRENTLY THIS LOW LOOKS TO TRACK
SOUTH OF MICHIGAN WHICH WOULD PUT THE CWA IN THE COLD SECTOR WITH
SNOW BEING THE MAIN PRECIP TYPE. COOLER TEMPS MAKE A RETURN NEXT
WEEKEND AS WESTERLY FLOW INCREASES OVER SOUTHEAST MICHIGAN.
MARINE...
THE SOUTHERLY WINDS WILL DIMINISH DURING THE COURSE OF THE EVENING
AS THE GRADIENT RELAXES. THIS WILL OCCUR AS A WEAK AREA OF LOW
PRESSURE EXPANDS ACROSS LAKE HURON TONIGHT. THIS LOW WILL ADVANCE
INTO ONTARIO ON SUNDAY WHICH WILL CAUSE THE WINDS TO TURN
NORTHEASTERLY OVER LAKE HURON. WIND SPEEDS WILL INCREASE DURING THE
AFTERNOON. GUSTS SHOULD REMAIN AT OR BELOW 25 KNOTS. THE GRADIENT
WILL THEN RELAX BY MONDAY. WEAK HIGH PRESSURE WILL RESULT IN LIGHT
WINDS INTO WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......JVC
AVIATION.....RBP
SHORT TERM...CB
LONG TERM....SC/SS
MARINE.......SC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
602 PM CST SAT NOV 30 2013
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 1135 AM CST SAT NOV 30 2013
VERY BENIGN PERIOD OF THE FORECAST. A WEAK CDFNT WILL CONTINUE TO
DROP SE ACRS THE REGION WITH A TRAILING MIDLVL SHORTWAVE TROF
AXIS. IT IS WITH THIS AXIS THAT MID-TO HIGH-LEVEL CLOUDS HAVE
SLIPPED INTO THE REGION. HOWEVER...SAID CLOUDS WILL EFFECTIVELY
SLIP ON OUT TNGT AS WEAK HIGH PRES SLIDES ACRS THE REGION
OVERNIGHT THRU THE FIRST HALF OF SUNDAY. SKIES WILL MAINLY CLEAR
OUT...BUT WITH WEAK FLOW ALOFT AND SFC HIGH PRES FORCING WINDS TO
DROP TO LGT/VRBL...IF NOT CALM...MOISTURE TRANSPORT OUT OF THE
AREA WILL BE NEARLY NON-EXISTENT. THIS WILL TRANSLATE TO THE
DEVELOPMENT OF LOW CLOUDS AND/OR FOG NEAR DAYBREAK SUN MRNG. THE
LOW CLOUDS WILL THEN SCOUR OUT DURG THE DAY TMRW...BUT MIDLVL
DECKS WILL REMAIN SO MOCLDY CONDS ARE EXPECTED BY LATE SUN AFTN.
MILD TEMPS WILL REMAIN IN PLACE THRU THE WEEKEND WITH NIL TEMP
ADVECTION. LOWS TNGT WILL DROP TO THE MID-TEENS TO LWR 20S
FOLLOWED BY HIGHS ON SUN THAT WILL HIT THE LOW-MID 30S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 346 PM CST SAT NOV 30 2013
THE LONG TERM REMAINS A CHALLENGE WITH RESPECT TO THE DEEP UPPER
LOW CURRENTLY DROPPING SOUTHWARD ACROSS WESTERN BRITISH COLUMBIA.
THE NAM AND GFS TODAY TAKE A MAJOR PIECE OF THE UPPER LOW DUE
EAST ONCE IT REACHES WASHINGTON STATE ON MONDAY... WHILE THE ECMWF
DRIVES IT FURTHER SOUTH. THE GFS HAS THE UPPER LOW REACHING MN BY
TUESDAY EVENING... WHILE THE ECMWF HOLDS MOST OF THE ENERGY BACK IN
IDAHO WITH DOWNSTREAM RIDGING ACROSS. HPC/WPC DISMISSED THE 12Z
SOLUTIONS OF THE NAM AND GFS AND PREFERRED THE DIGGING ECWMF DUE
TO THE BUILDING RIDGE OVER AK.
THE ECMWF FORECAST HAS REMAINED VERY CONSIST WITH THE HANDLING OF
THE UPPER LEVEL OVER THE PAST 3 RUNS (36 HOURS) WITH EVEN THE GEM
TODAY COMING MORE IN LINE WITH THE ECMWF. THEREFORE... MUCH OF
WHAT WAS DONE TODAY WAS MORE OF A BLEND WITH EC/GEM GUIDANCE.
THERE ARE DEFINITELY SOME CONCERNS IN THE UPCOMING FORECAST. LIGHT
SNOW IS STILL EXPECTED SUNDAY NIGHT AND MONDAY AS RIPPLES OF
UPPER LEVEL ENERGY PASS ACROSS THE NORTHERN PLAINS AND UPPER
MISSISSIPPI VALLEY REGION... IN CONCERT WITH A STEADY STREAM OF LOW
LEVEL WAA. THE LIGHT SNOW SUNDAY NIGHT IS MAINLY CONFINED TO THE
MN CWA WITH A WEAKENING TREND TO THE EAST EARLY ON MONDAY AS THE
LOW LEVEL UPGLIDE DIMINISHES. ANOTHER SURGE OF SNOW ARRIVES FROM
THE DAKOTAS MONDAY NIGHT... WITH AN INCH OR TWO LIKELY ACROSS
CENTRAL MN AND ADJOINING AREAS OF WEST CENTRAL WI.
THINGS BECOME MORE INTERESTING FROM TUESDAY INTO WEDNESDAY AS
SURFACE LOW PRESSURE TAKES SHAPE IN EASTERN SD AND ADVANCES TO
NEAR DULUTH BY WEDNESDAY EVENING. TUESDAY AFTERNOON AND TUESDAY
NIGHT COULD BE A PERIOD FOR SNOW ACCUMULATION IN THE 3 TO 5
INCH RANGE ACROSS CENTRAL MN PER THE ECMWF. THE IS THE MAIN
CONCERN IN THE FORECAST AS THE POTENTIAL SNOW ACCUMULATIONS WILL
NEED TO BE MONITORED. WHILE THIS IS OCCURRING... IT WILL BE
WARMING IN THE LOW LEVELS ACROSS SOUTHERN MN WITH A CHANGEOVER TO
RAIN TUESDAY AFTERNOON. THE ECMWF SUGGESTS IT COULD STAY ALL RAIN
ACROSS SOUTH CENTRAL AND SE MN TUESDAY NIGHT WITH DEW POINTS
RISING INTO THE MIDDLE 30S. WE DIDN/T PUSH THINGS THAT FAR TODAY
WITH THE GEM ON THE COOLER SIDE OF THE ENVELOPE. WITH THE LOW
LIFTING NORTHEAST ACROSS CENTRAL MN ON WEDNESDAY... ARCTIC AIR
SHOULD BEGIN SURGING INTO SW MN BY AFTERNOON AND ACROSS THE
REMAINDER OF THE FA WEDNESDAY EVENING. WINDY AND MUCH COLDER
CONDITIONS WILL OCCUR IN THE WAKE OF THE ARCTIC FRONT WEDNESDAY
NIGHT. TEMPERATURES WILL BE STEADY OR SLOWLY FALLING ON THURSDAY
ALONG WITH A BRISK WEST TO NORTHWEST WIND. THE COLD TEMPERATURES
WILL REMAIN ACROSS THE REGION THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 602 PM CST SAT NOV 30 2013
IFR/LOW MVFR CEILINGS MEANDER FROM KDVL THROUGH KAXN TO KMZH AND
KHYR EARLY THIS EVENING. THE CEILINGS ARE IN THE WAKE OF A COLD
FRONT. THEY ARE DROPPING SOUTH NEAR 17 KNOTS. THE RAP AND HRRR
HAVE A GOOD HANDLE ON THE SITUATION AND THEREFORE DROVE THEM ON
SOUTH THROUGH ALL BUT KRWF THIS EVENING. SOME MVFR VISIBILITY IN
BR POSSIBLE AROUND DAYBREAK SUNDAY. THE CEILINGS SHOULD BREAK UP
IN THE MORNING... BUT WITH RIDGING BUILDING IN...THEY MAY LINGER
LONGER ACROSS EASTERN MN AND WEST CENTRAL WI. THE DISSIPATION MAY
NEED TO BE ADJUSTED IN THE NEXT ISSUANCE. LIGHT NW WINDS
OVERNIGHT GRADUALLY BECOMING ESE SUNDAY AFTERNOON.
KMSP...MVFR CEILINGS ARRIVING FROM THE NORTH IN THE 05Z-06Z
TIME FRAME. SOME CONCERN THAT THEY MAY DROP BELOW 010 FROM 10Z-
14Z ALONG WITH SOME 5-6SM BR. VFR CEILINGS EXPECTED TO RETURN BY
LATE MORNING BUT THIS COULD GET STRETCHED INTO THE AFTERNOON WITH
HIGH PRESSURE AND A LIGHT WIND FIELD OVERHEAD.
/OUTLOOK FOR KMSP/
SUN NGT...VFR...POSSIBLY MVFR CIGS/-SN LATE. WINDS ESE 5 KTS.
MON...MVFR OR LOWER CIGS/VSBYS IN -SN. SE WINDS 10 KTS.
TUE...IFR/MVFR CIGS IN -SN...POSSIBLY MIXED WITH RA BY AFTN. SE
10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JPC
LONG TERM...RAH
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
948 PM EST SAT NOV 30 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTH COUNTRY THIS AFTERNOON AND TONIGHT WILL
GIVE WAY TO AN UPPER LEVEL LOW PRESSURE SYSTEM...WHICH WILL BRING
WINTRY CONDITIONS TO THE AREA SUNDAY INTO PORTIONS OF NEXT MONDAY. A
COASTAL LOW COULD AFFECT PORTIONS OF THE NORTH COUNTRY NEXT TUESDAY
AND TUESDAY NIGHT...AND YET ANOTHER SYSTEM WEDNESDAY NIGHT INTO NEXT
THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 948 PM EST SATURDAY...EARLIER BURST OF WARM AIR ADVECTION
DRIVEN LIGHT SNOWS MOVING ACROSS NORTHERN AND CENTRAL VERMONT HAS
MOVED INTO NEW HAMPSHIRE AT THIS HOUR. RECENT OBSERVATIONS AND
MODEL TRENDS SUGGEST THE PROSPECT FOR ADDITIONAL LIGHT SNOW
THROUGH THE REST OF THE EVENING LOOKS TO BE LIMITED. THE
STRONGEST 925-850 MB WARM ADVECTION AND ASSOCIATED LIFT IS TO OUR
EAST...AND THE UPSTREAM SHORTWAVE TROUGH DOESN`T LOOK IMPRESSIVE.
IN FACT THE NAM/WRF SHOW THE SHORTWAVE MORE OR LESS SHEARING OUT
OVER NORTHERN NEW YORK TOWARDS MORNING. SO I`VE GONE AHEAD AND
ADJUSTED TIMING OF LIGHT SNOW BACK TO 09-10Z FOR THE SAINT
LAWRENCE VALLEY AND THE ADIRONDACKS...AND AROUND 12Z FOR THE FAR
NORTHERN CHAMPLAIN VALLEY AND NORTHERN VERMONT. THIS TIMING ALSO
IS SUPPORTED BY RECENT HRRR AND NAM/WRF REFLECTIVITY DATA.
TEMPERATURES REMAIN GENERALLY IN THE MID TO UPPER 20S...AND UNDER
A DECK OF LOW TO MID-LEVEL CLOUDINESS AS WELL AS SOUTH
WINDS...FEEL THAT TEMPERATURES ARE LIKELY TO HOVER OR RISE A FEW
DEGREES TOWARDS MORNING. LOWS IN MOST LOCATIONS HAVE ALREADY BEEN
REACHED EXCEPT FOR THE NORTHEAST KINGDOM WHICH SHOULD TAKE PLACE
BEFORE MIDNIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 237 PM EST SATURDAY...GOING INTO SUNDAY...SHORTWAVE AIDED BY A
WEAK INVERTED TROUGH...WILL BRING LIGHT SNOWFALL TO THE AREA.
FOCUS OF MOST PRECIP THRU THE DAY WILL BE ACROSS NORTHERN ZONES
DUE TO LACK OF FORCING INTO THE AREA. WK RIDGING ALONG THE COAST
SUN NGT/EARLY MONDAY WILL ALLOW FOR SHIFT OF UPPER LEVEL WINDS
FROM MORE WESTERLY TO SOUTHWESTERLY FOR MON/MON NGT. SNOWFALL AMTS
ACROSS THE CWA FOR THIS EVENT WILL RANGE FROM A D-1" IN VALLEY
LOCALES EAST OF THE DACKS...AND 1-2" FOR DACKS/SLV AND NC NE VT.
HIGHER AMTS IN THE ST LAW VALLEY TOWARDS TAIL-END OF EVENT AID BY
SW FLOW BRINGING SOME LK ONTARIO MOISTURE INTO THE AREA. LINGERING
-SW FOR MON/MON NGT ON TAP AS BROAD SW FLOW OVER THE CWA WITH
UPPER LEVEL TROUGH TO OUR WEST AND COASTL SYSTEM WORKING UP THE
EAST COAST. AS A RESULT OF W/SW SFC FLOW...WAA REMAINS INTACT WITH
A GRADUAL INCR IN HIGHS THRU THE PERIOD...AND ABV NORMAL LOWS DUE
TO CLDS AND SFC WINDS. HIGHS WILL RANGE IN THE LOW/MID 30S AND
LOWS IN THE 20S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 351 PM EST SATURDAY...ECMWF AND GFS MODELS SHOWING TIMING
DIFFERENCES THROUGH THE PERIOD WITH THE GFS MODEL A BIT FASTER
WITH THE MOVEMENT OF SYSTEMS. THUS...GIVEN TIMING
DIFFERENCES...FORECASTER CONFIDENCE IS ONLY FAIR AT THIS TIME.
HOWEVER...GIVEN DIFFERENCES...HAVE LEANED TOWARD THE SLOWER ECMWF
SOLUTION THROUGH THE PERIOD...AS THIS MODEL TENDS TO DO BETTER IN
THE EXTENDED TIME RANGE.
ON TUESDAY...GFS MODEL DEVELOPS SURFACE LOW SOUTH OF CAPE COD
EARLY TUESDAY AND THEN SWINGS IT EAST SOUTH OF NOVA SCOTIA BY
TUESDAY EVENING. GFS BRINGS SNOW SHOWERS ACROSS VERMONT ON
TUESDAY...WHILE THE ECMWF HAS THIS FEATURE FURTHER EAST. MODELS DO
SHOW AN UPPER TROUGH WILL ALSO APPROACH FROM THE WEST ON
TUESDAY...SO WILL KEEP IN LOW CHANCE POPS FOR TUESDAY AND TUESDAY NIGHT.
ECMWF MODEL SHOWING AN UPPER RIDGE TO BUILD INTO THE REGION BY
WEDNESDAY AFTERNOON AND REMAINING THROUGH MIDDAY ON
THURSDAY...WHILE THE GFS MODEL TENDS TO BRING MOISTURE FROM A
FRONTAL SYSTEM INTO THE REGION BY WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT...AND THEN EAST OF THE REGION BY THURSDAY. ECMWF
HAS THIS FEATURE MUCH FURTHER WEST ACROSS THE WESTERN GREAT LAKES
WITH A STRONG UPPER RIDGE OVER THE REGION WEDNESDAY NIGHT AND
THURSDAY. THUS...HAVE GONE WITH SLOWER ECMWF TIMING AND WILL HOLD
OFF BRINGING MOISTURE FROM THIS NEXT FRONTAL SYSTEM UNTIL LATE
THURSDAY AFTERNOON AND THURSDAY NIGHT.
ECMWF AND GFS MODELS BRING MOISTURE NORTHEAST INTO THE REGION
THURSDAY NIGHT AND FRIDAY...SO HAVE CHANCE POPS FOR RAIN OR SNOW
SHOWERS. MODELS SHOWING SIGNIFICANT DIFFERENCES FRIDAY NIGHT AND SATURDAY
WITH THE ECMWF MUCH SLOWER WITH THE MOVEMENT OF THE FRONTAL
SYSTEM...WHILE THE GFS IS MORE PROGRESSIVE AND BRINGS MOST
PRECIPITATION TO AN END FRIDAY NIGHT AND SATURDAY. THE ECMWF MODEL
HAS THE FRONTAL SYSTEM PARALLEL TO THE UPPER FLOW AND THUS IS SLOWER.
HAVE LEANED TOWARD THE SLOWER ECMWF MODEL AND WILL KEEP IN CHANCE
POPS FOR PRECIPITATION FRIDAY NIGHT AND SATURDAY.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...BKN-OVC CONDITIONS EXPECTED THROUGH THE TAF
PERIOD. WARM FRONT CROSSING VT 00-03Z WILL BRING BRIEF PERIOD OF
SNOWFALL BTV/MPV/RUT...BUT IT APPEARS CIGS/VSBY WILL ONLY BRIEFLY
DROP INTO MVFR RANGE BEFORE IMPROVING BACK TO OVC080-120 FOR THE
BALANCE OF THE OVERNIGHT PERIOD. MODERATE GRADIENT FLOW IN PLACE
BETWEEN DEPARTING SFC HIGH IN THE GULF OF MAINE AND SFC LOW OVER
LAKE HURON. THIS WILL BRING SOUTH WINDS 10-15KTS WITH A FEW GUSTS
20-22 KTS THRU 12Z SUNDAY. GRADIENT GRADUALLY SLACKENS DURING THE
DAYLIGHT HRS SUNDAY...SO WINDS SHOULD SUBSIDE TO 5-10 KTS AFTER
12Z SUNDAY. WEAKENING SFC TROUGH CROSSES THE REGION 15Z SUN THRU
00Z MONDAY...BRINGING MVFR/BRIEF IFR CEILINGS/VSBY AND SOME VERY
LIGHT SNOW TO THE TAF SITES MAINLY SUNDAY AFTN. LIGHT SNOW
ACCUMULATION POSSIBLE ALL TAF LOCATIONS...GENERALLY DUSTING-1"
WITH MINOR IMPACTS TO AVIATION OPERATIONS SUNDAY AFTN.
OUTLOOK 00Z MONDAY THROUGH THURSDAY...
12Z MONDAY THROUGH 18Z WEDNESDAY...MAINLY VFR...BUT WITH A CHANCE
FOR SOME SNOW SHOWERS AND MVFR CONDITIONS.
18Z WEDNESDAY THROUGH 00Z FRIDAY...MAINLY VFR AS A RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.MARINE...
AS OF 140 PM SATURDAY...SOUTHERLY WINDS FUNNELING UP THE CHAMPLAIN
VALLEY AND OVER THE LAKE HAVE STRENGTHENED TO THE LEVEL THAT A
LAKE WIND ADVISORY IS NEEDED. WINDS OF AROUND 20-25 KNOTS WITH
GUSTS AROUND 30 KNOTS ARE EXPECTED FOR THE REMAINDER OF THIS
AFTERNOON AND THROUGHOUT THE OVERNIGHT HOURS. THE STRONGEST OF THE
WINDS ARE EXPECTED ACROSS THE BROAD LAKE, AND WILL PRODUCE WAVES
INTO THE 3 TO 5 FOOT RANGE. WINDS WILL BE A BIT WEAKER AROUND THE
ISLANDS, AS WILL WAVES BE SMALLER. THESE STRONG SOUTHERLY WINDS
ARE EXPECTED TO QUICKLY DIMINISH SHORTLY AFTER SUNRISE SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...JN/LOCONTO
SHORT TERM...JN
LONG TERM...WGH
AVIATION...BANACOS/WGH
MARINE...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
108 AM CST FRI NOV 29 2013
.UPDATE...
ISSUED AT 100 AM CST FRI NOV 29 2013
DECREASED CLOUDS A BIT COMPARED TO WHAT WAS IN THE FORECAST FOR
THE REST OF THE OVERNIGHT. WITH WARM AIR ADVECTION OVERNIGHT JUST
OFF THE SURFACE...AHEAD OF THE SURFACE WARM FRONT...THERE IS A
CHANCE THAT LOWER CLOUDS COULD FORM...AND SOME MODEL GUIDANCE
SHOWS THIS. HOWEVER...THE TREND OVER THE PAST FEW HOURS HAS BEEN
FOR THE LOW CLOUDS TO DECREASE...NOT INCREASE.
MID CLOUD IS ALSO WORKING ITS WAY THROUGH NORTHEAST MONTANA AND
INTO NORTHWEST NORTH DAKOTA. BASICALLY VARIABLE CLOUDS
OVERNIGHT...PARTLY CLOUDY AND TIMES...MOSTLY CLOUDY AT OTHER
TIMES.
BASED ON TEMPERATURE TRENDS...AND WITH SOUTHEAST SURFACE WIND 5 TO
15 MPH...MAYBE MORE LIKE 10 TO 15 MPH...WILL NOT EXPECT
TEMPERATURES TO FALL MUCH FROM WHERE THEY ARE AS OF THIS
WRITING. WIND WILL MAKE IT FEEL 5 TO 10 DEGREES LOWER THAN WHAT
THE THERMOMETER SHOWS.
NO CHANGES TO THE REST OF THE SHORT TERM FOR NOW.
UPDATE ISSUED AT 851 PM CST THU NOV 28 2013
CLOUDS AND TEMPERATURES CONTINUE TO BE THE MAIN ISSUES TONIGHT.
COOL HIGH PRESSURE ACROSS MINNESOTA WITH A WARM FRONTAL BOUNDARY
ACROSS MONTANA. THE TREND HAS BEEN CLEARING SKIES BUT LATEST
SATELLITE PICTURES SUGGEST CLOUDS MAYBE REFORMING ACROSS CENTRAL
NORTH DAKOTA NORTH OF LAKE SAKAKAWEA. NOW WILL BE TRENDING THE
CLOUDS BACK INTO THE PICTURE TONIGHT. ALSO TEMPERATURES MAY HIT
THEIR LOWS LATE THIS EVENING OR EARLY AFTER MIDNIGHT THEN BECOME
STEADY OR RISE A BIT BY MORNING...ESPECIALLY JAMES RIVER VALLEY
NORTH TO THE DEVILS LAKE BASIN. DO NOT SEE ANY PRECIP IN THE
FORECAST FOR TONIGHT AS THE FLURRIES FROM THURSDAY AFTERNOON HAVE
ENDED.
UPDATE ISSUED AT 541 PM CST THU NOV 28 2013
AT 5 PM CST...SURFACE HIGH PRESSURE EXTENDED ACROSS THE EASTERN
DAKOTAS. A SURFACE TROUGH AND ASSOCIATED WARM FRONT EXTENDED
THROUGH CENTRAL MONTANA. THE THIN LAYER OF STRATUS HAS ERODED
IN WEAK LOW LEVEL WARM ADVECTION...LEAVING NARROW BANDS OF CLOUDS
ACROSS CENTRAL NORTH DAKOTA WITH THE WEST GENERALLY MOSTLY CLEAR.
CURRENT THINKING IS THE CLOUDS WILL EVENTUALLY BACK FILL IN WITH
SHALLOW COOL AIR IN PLACE AS THE WARM FRONT MOVES EAST. SOME
UNCERTAINTY HERE ALSO...AS LOW LEVEL WARM ADVECTION AT H850 MAY
SUPPRESS CLOUDS LATER TONIGHT. BUT WENT WITH AN INCREASE IN CLOUDS
THROUGH MIDNIGHT....THEN CLOUDY AFTER MIDNIGHT. CURRENT
TEMPERATURES AND WINDS SEEM OK FOR NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE SKY COVER
TONIGHT AND IMPACT ON TEMPERATURES.
PORTIONS OF THE STRATUS DECK HAVE ERODED ACROSS THE FORECAST AREA
THIS AFTERNOON. RAP 925MB RELATIVE HUMIDITY HAS THIS MODELED
RELATIVELY WELL AND SUGGEST THAT STRATUS SHOULD FILL BACK IN THIS
EVENING AND OVERNIGHT. TEMPERATURES WILL LIKELY DROP QUICKLY THIS
EVENING IN CLOUD FREE AREAS...BEFORE THE STRONGER SE WINDS
DEVELOP. THE STRONGER GRADIENT WILL BE LOCATED OVER THE WEST AND
HAVE KEPT OVERNIGHT LOWS RELATIVELY MILD...IN THE TEENS TO LOWER
20S. EAST/NORTHEAST PORTIONS OF THE FORECAST AREA...FROM THE
TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY...SHOULD BE ABLE
TO GET INTO THE SINGLE DIGITS. HOURLY TRENDS WILL LIKELY NEED TO
BE UPDATED THIS EVENING.
ON FRIDAY...STRONGER WARM AIR ADVECTION WILL KICK IN...WITH HIGHS
IN THE MID 20S NORTHEAST TO LOWER 40S SOUTHWEST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE RETURN OF ARCTIC AIR
AND THE POTENTIAL FOR WIDESPREAD ACCUMULATING SNOW NEXT WEEK.
THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT ON A SIGNIFICANT
UPPER LEVEL LOW COMING ONSHORE TO THE PACIFIC NORTHWEST ON MONDAY.
THEREAFTER...UNCERTAINTY INCREASES IN REGARDS TO THE EVOLUTION AND
PROPAGATION OF THIS LOW ACROSS THE INTERMOUNTAIN WEST AND
POTENTIALLY INTO THE NORTHERN PLAINS LATE TUESDAY AND INTO
WEDNESDAY. THE 12 UTC ECMWF CONTINUES THE TREND OF ITS PREVIOUS
RUNS OVER THE PAST 24 HOURS OF THE DEEPEST LOW YIELDING
SIGNIFICANT QPF AND SNOW ACROSS THE NORTHERN PLAINS TUESDAY INTO
WEDNESDAY. THE 12 UTC GFS HAS TRENDED MORE TOWARDS THE
ECMWF...HOWEVER...IS NOT AS DEEP WITH LESSER QPF...MUCH LIKE THE
12 UTC GEM. THE ECMWF HAS BEEN THE MOST CONSISTENT AND IS
SUPPORTED BY THE GEFS MEAN...AND FAVORED BY WPC. THUS...WILL
CONTINUE TO MONITOR THE POTENTIAL FOR ACCUMULATING SNOW NEXT WEEK.
NO MATTER THE MODEL...ARCTIC AIR IS FORECAST TO OVERTAKE THE
NORTHERN PLAINS ONCE AGAIN TUESDAY THROUGH THE END OF NEXT WEEK
WITH A PATTERN SHIFT TO BROAD WESTERN AND CENTRAL CONUS UPPER
LEVEL TROUGHING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT
100 AM CST FRI NOV 29 2013
THE FIRST HALF OF THIS TAF FORECAST PERIOD IS COMPLICATED BECAUSE
OF UNCERTAINTY CONCERNING THE CEILING FORECAST.
THERE HAVE BEEN PATCHES OF MVFR CIGS ALONG THE MONTANA BORDER...
MOVING NORTHWEST IN SOUTHEAST SURFACE FLOW...AND MVFR CIGS FROM
SOUTHEAST OF KMOT THROUGH THE KJMS AREA. THE TREND HAS BEEN FOR
THEM TO BE DECREASING RATHER THAN INCREASING IN COVERAGE.
HOWEVER...WITH SHALLOW COLD AIR IN PLACE...A SURFACE WARM FRONT IN
EASTERN MONTANA...AND WARM AIR ADVECTION JUST OFF THE DECK...WITH
AN INVERSION EXPECTED OVER MOST OF THE AREA BY DAYBREAK FRIDAY...
THE EXPECTATION THAT MVFR CIGS WILL REDEVELOP IS SUPPORTED. TIMING
AND THE EXTENT OF THE CLOUDS ARE UNCERTAIN. CURRENT TAFS USED
TEMPO GROUPS TO ACCOUNT FOR THE REFORMATION OF LOWER CLOUDS.
CONDITIONS WILL IMPROVE TO VFR AGAIN FRIDAY AFTER 16-18Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
LONG TERM...AYD
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1003 PM CST SAT NOV 30 2013
.UPDATE...
ISSUED AT 1002 PM CST SAT NOV 30 2013
FORECAST FAIRLY MUCH IN CONTROL THIS EVENING...WITH SOME MINOR
CHANGES MAINLY TO TRENDS IN TEMPERATURES...AND TO INCREASE CLOUD
COVER OVERNIGHT. FOR MOST...MID CLOUDS WILL BE HARD TO SHAKE
TONIGHT WITH MID LEVEL BOUNDARY STALLING ACROSS THE AREA WITH
STRONGER WAVE APPROACHING THE AREA DURING THE AFTERNOON AND
EVENING ON SUNDAY. ALSO HAVE TO KEEP AN EYE ON LOWER CLOUDS WHICH
HAVE BEEN STEADILY PRESSING SOUTH AND SOUTHWEST ACROSS EASTERN
NORTH DAKOTA AND NORTHERN MINNESOTA. NAM/GFS ARE DOING THEIR
TYPICAL HORRID JOB IN DEFINING THEM...AND IF DEPENDING ON RAP TO
PICK UP TREND...WOULD THREATEN TO DRIFT INTO KMWM/KMML/KBKX AREAS
BY AROUND 12Z. DID NUDGE UP OVERNIGHT LOWS SOMEWHAT WITH
INCREASED SKYCOVER.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 315 PM CST SAT NOV 30 2013
HIGH PRESSURE WILL BUILD OVER THE AREA TONIGHT WITH WINDS RAPIDLY
BECOMING LIGHT AFTER SUNSET. THERE WILL BE A LOT OF BREAKS IN THE
CLOUDS...ESPECIALLY ALONG AND SOUTH OF I90 SO TEMPERATURES COULD
FALL QUICKLY IN THE EARLY EVENING. AS THE HIGH MOVES TO THE EAST
OVERNIGHT AND THE 850 MB THERMAL GRADIENT MOVE INTO EASTERN SD...
CLOUDS WILL INCREASE ACROSS CENTRAL SD AND INTO PORTIONS OF
EASTERN SOUTH DAKOTA. HOW FAST THESE CLOUDS MOVE IN WILL HAVE A
LARGE IMPACT ON TEMPERATURES. EXPECTING CLOUDS TO REACH KHON BY
MIDNIGHT BUT NOT GET INTO MUCH OF NORTHWEST IOWA UNTIL SUNDAY
MORNING. SO HAVE TEMPERATURES STAY IN THE MID 20S ALONG AND WEST
OF THE JAMES RIVER WITH UPPER TEENS ALONG AND EAST OF I29.
ON SUNDAY...MOST AREAS WILL BECOME OVERCAST AS MID CLOUDS OVERSPREAD
THE REST OF THE AREA BY SUNDAY MORNING. THE SURFACE RIDGE WILL ALSO BE
OVER MN AND IA MUCH OF THE DAY KEEPING WINDS LIGHT AND LIMITING
MIXING AND RETURN OF WARM AIR AT LOW LEVELS. THIS WILL KEEP
TEMPERATURES 10 DEGREES COOLER THAN TODAY WITH HIGHS IN THE 30S IN
SW MN AND PORTIONS OF NW IA AND EAST CENTRAL SD. WARMEST TEMPERATURES
WILL BE IN THE MISSOURI VALLEY IN THE LOWER TO MID 40S. A WEAK UPPER
WAVE WILL MOVE INTO EASTERN SOUTH DAKOTA SUNDAY AFTERNOON. WHILE THE
UPPER LEVEL FORCING FOR ASCENT IS THERE...THERE IS LITTLE LOW LEVEL
FRONTOGENESIS OR MOISTURE WHICH WILL REALLY LIMIT PRECIPITATION. BUT
WITH THE UPPER WAVE APPROACHING...DID CONTINUE WITH A SLIGHT CHANCE
OF PRECIPITATION. TEMPERATURES WILL BE IN THE MID TO UPPER 30S WITH
UPPER 20S DEW POINTS. THAT WOULD SUGGEST PRIMARILY A RAIN AND SNOW
MIX TRENDING TOWARD ALL SNOW AFTER SUNSET WHEN TEMPERATURES FALL
TOWARD FREEZING.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CST SAT NOV 30 2013
THE LIGHT PRECIPITATION...IF IT DEVELOPS TO THE SURFACE...SHOULD
CONTINUE TO DEVELOP EAST SOUTHEAST INTO SOUTHWEST MN AND PART OF
NORTHWEST IA SUNDAY EVENING. AFTER A BRIEF PERIOD OF LOW LEVEL
COOLING AND MIXED RAIN AND SNOW ON THE SOUTHWESTERN EDGE OF THE
PRECIPITATION THREAT AREA...ANY PRECIPITATION SHOULD BE LIGHT
SNOW. MODEL SOUNDINGS ON BUFKIT SHOW CONTINUED MARGINAL
TEMPERATURES ALOFT THROUGH THE EVENING BUT FEEL ANY PRECIPITATION
THAT DOES OCCUR WILL COOL THE AIR ENOUGH TO KEEP IT AS SNOW.
NEVERTHELESS...TEMPERATURES SHOULD LEVEL OFF SUNDAY EVENING AFTER
EARLY COOLING AND MAY RISE A BIT LATER IN THE NIGHT AS A WARMING
PATTERN SLOWLY GETS GOING.
AFTER THIS WAVE SLIDES EAST OF AREA LATE SUNDAY NIGHT...STILL DO
NOT SEE ENOUGH SUPPORT TO MENTION PRECIPITATION FOR MONDAY. THE
WARMING PICKS UP A LITTLE FOR MONDAY AND WITH SOME HEATING THROUGH
AN ASSORTMENT OF HIGHER CLOUDS...MONDAY SHOULD BE MILD WITH HIGHS
IN THE 40S...LOWER 50S SOUTHWEST.
IT WAS GENERALLY AGREED EARLY ON TODAY THAT THE NAM AND GFS ARE
PERFORMING POORLY ON THEIR RAPID ADVANCE OF THE NORTHERN UPPER LOW
AND THE LEADING SURFACE LOW AND FRONT. THE EC AND CANADIAN ARE
CLOSE AND APPEAR MORE CONSISTENT DURING THE LAST DAY OR SO WITH A
DEEPER DIGGING OF THE UPPER TROUGH OVER THE WESTERN USA...AND A
SLOWER ADVANCE OF THE SURFACE LOW AND FRONT. THEREFORE...EXPECT
TUESDAY TO STILL BE MILD...NOT AS WARM AS MONDAY...WITH A CHANCE
TO SLIGHT CHANCE PRECIPITATION THREAT BEING LIGHT RAIN. HAVE
ACTUALLY BEGUN THIS FAR NORTH AS A SLIGHT CHANCE OF RAIN OR
FREEZING RAIN MONDAY NIGHT. STILL DO NOT SEE CONCRETE SUPPORT FOR
PRECIPITATION AS FAR EAST AS OUR AREA...BUT MOISTURE LEVELS DO
INCREASE AND THE FLOW VERY SLOWLY BECOMES MORE FAVORABLE FOR
SCATTERED LIGHT PRECIPITATION AHEAD OF THE FRONT AND LOW.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT WILL SEE A BETTER CHANCE OF
LIGHT PRECIPITATION ALONG WITH A TURN TO COLDER...WHICH SHOULD
CHANGE ANY PRECIPITATION TO SNOW OVER MOST OF THE AREA BY LATE
WEDNESDAY...EVEN ACCORDING TO THE EC AND CANADIAN. THE PROBLEM IS
THAT OUR FORECAST AREA EVIDENTLY WILL NOT SEE MORE THAT AREAS OF
LIGHT PRECIPITATION DURING THIS TIME AS MEAGER SUPPORT AND
ADVECTION IS REPLACED BY THE STRONG COLD ADVECTION WHICH FAIRLY
QUICKLY INCREASES IN DEPTH. THE BEST CHANCE OF LIGHT SNOW
ACCUMULATIONS APPEARS TO BE IN THE FIRST HOURS AFTER THE AIR
BECOMES COLD ENOUGH FOR SNOW. BUT POPS THROUGH THE PERIOD WILL
STAY AT MOST IN THE CHANCE CATEGORY.
WILL GO WITH THE EXTENDED GUIDANCE AND KEEP POPS BELOW MENTION
THRESHOLD THURSDAY THROUGH SATURDAY...EXCEPT FOR SOME FLURRIES ON
THURSDAY. THE EC WITH ITS SHARPER LARGE SCALE UPPER TROUGH
INDICATES A THREAT OF STEADY LIGHT TO MODERATE SNOW DEVELOPING
RIGHT AFTER THE FORECAST PERIOD...THAT IS NEXT SUNDAY AND MONDAY.
THE OVERNIGHT 06Z GFS HAD A LITTLE SOMETHING LIKE THIS BUT THE 12Z
RUN KEEPS ITS SPEEDY NATURE GOING THROUGH AND BEYOND THE EXTENDED
PERIOD.
AS THE COLD AIR ARRIVES THERE WILL BE SOME WIND...WITH WIND CHILLS
GOING BELOW ZERO LATER THIS WEEK. A SNOW COVER COULD BRING COLDER
TEMPERATURES AND PERHAPS THE NEED FOR A WIND CHILL ADVISORY BY THE
START OF NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1002 PM CST SAT NOV 30 2013
FOR THE MOST PART...VFR CONDITIONS ARE EXPECTED TO CONTINUE FOR
TAF SITES THROUGH 06Z MON. A WEAK SYSTEM WILL BRING A LOW THREAT
FOR SOME LIGHT PRECIPITATION INTO EASTERN SOUTH DAKOTA AFTER
21Z...BUT FOR NOW WILL KEEP CONDITIONS WITH MENTION LIMITED TO
KHON AND KFSD...AND ALSO AS VFR CONDITIONS. LOWER CLOUDS WORKING
SOUTHWEST IN THE SHORT TERM ARE NOT EXPECTED TO REACH KHON OR KFSD
AT THIS TIME...BUT AREAS TOWARD KBKX/KMML COULD FIND SOME LIFR
CEILINGS LATER TONIGHT AND EARLY SUNDAY MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...SCHUMACHER
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
946 PM CST SAT NOV 30 2013
.UPDATE...
CURRENT FORECAST IS IN GOOD SHAPE AND NO MAJOR CHANGES ARE NEEDED
AT THIS TIME. CLOUD COVER WILL CONTINUE TO INCREASE THROUGH SUNDAY
MORNING WITH THE THICKEST AND MOST PERSISTENT CLOUD COVER
SPREADING NORTHEAST INTO THE ARKLATEX. A FAST MOVING WEAK UPPER
DISTURBANCE WILL SWING THROUGH THE PLAINS TOMORROW AND MAY HELP
TRIGGER A FEW SHOWERS ACROSS THE NORTHEAST COUNTIES ON THE LEADING
EDGE OF THE BETTER MOISTURE. OTHERWISE IT WILL BE QUIET WITH
CONTINUED WARMING TEMPERATURES INTO EARLY NEXT WEEK.
DUNN
&&
.AVIATION...
/00Z TAFS/
TIMING CIG TRENDS OVERNIGHT INTO EARLY SUNDAY WILL BE
CHALLENGING ALONG WITH BRIEF VSBY DROPS AROUND DAYBREAK WITH LOW
LEVEL WINDS SLIGHTLY VEERED.
VFR CIGS WILL CONTINUE ACROSS WACO AND AREAS SOUTH OF I-20 WHILE
DFW METRO AIRPORTS ENCOUNTER MAINLY SCT LOW CLOUDS WITH OCCASIONAL
BKN-OVC HIGH CLOUDINESS THROUGH MIDNIGHT.
AFTER PERUSAL OF LATEST BUFR SOUNDING DATA AND RUC SOUNDINGS...IT
APPEARS MVFR CIGS WILL NOT ARRIVE INTO DFW UNTIL BETWEEN 07-09Z
DUE TO THE VEERED LOW LEVEL WINDS THROUGH 925MB. WILL BRING MVFR
INTO WACO AN HOUR OR TWO SOONER WITHIN THE MORE MOIST LOW LEVEL
ENVIRONMENT. IFR CONDITIONS WITH BRIEF MVFR VSBYS LOOK POSSIBLE BY
DAYBREAK SUNDAY AT ALL TERMINALS WITH BOUNDARY LAYER WINDS ONLY
SSW 10-15 KTS. WACO WILL BE A TAD SLOWER TO RISE SUNDAY DUE TO
LIGHTER WINDS AND MORE MOISTURE VERSUS DFW. NEVERTHELESS...ALL
TERMINALS WILL RISE INTO MVFR BY MID-LATE MORNING AND BACK TO VFR
BY EARLY-MID AFTERNOON SUNDAY WITH MIXING/HEATING.
S/SW WINDS 5-9 KTS OVERNIGHT WILL INCREASE TO BETWEEN 10-15 KTS
ONCE AGAIN BY MIDDAY SUNDAY. NO PRECIPITATION IS EXPECTED.
05/
&&
.PREV DISCUSSION... /ISSUED 334 PM CST SAT NOV 30 2013/
A LOW LEVEL WARM AIR ADVECTION PATTERN WILL CONTINUE ACROSS NORTH
TEXAS TONIGHT WITH THE RETURN OF STRATUS OVERNIGHT. LOWS TONIGHT
WILL RANGE FROM THE MIDDLE 40S IN THE NORTH TO THE MIDDLE 50S IN
THE SOUTH.
A SHORT WAVE TROUGH WILL TRANSLATE ACROSS THE CENTRAL AND SOUTHERN
PLAINS ON SUNDAY AND ALLOW A WEAK COLD FRONT TO CROSS THE RED
RIVER. ALTHOUGH MOISTURE WILL BE LIMITED AND GENERALLY CONFINED TO
THE LOWEST LEVELS OF THE ATMOSPHERE. A FEW SHOWERS/STORMS MAY
ACCOMPANY THE SHORT WAVE...MAINLY ACROSS THE NORTHEASTERN ZONES
WHERE MOISTURE AND INSTABILITY WILL BE THE MOST FAVORABLE.
DRIER AND SLIGHTLY COOLER AIR WILL MOVE INTO NORTH TEXAS SUNDAY
NIGHT AS WEAK SURFACE HIGH PRESSURE TEMPORARILY BUILDS INTO THE
REGION. BY MONDAY...THE FRONT WILL BEGIN TO LIFT NORTHWARD IN
RESPONSE TO A DEEPENING SURFACE TROUGH ACROSS THE CENTRAL HIGH
PLAINS. LOW LEVEL WARM AIR ADVECTION WILL QUICKLY INCREASE MONDAY
NIGHT AND TUESDAY AS THE SURFACE TROUGH CONTINUES TO DEEPEN AHEAD
OF A DEVELOPING LONG WAVE TROUGH ACROSS THE WESTERN UNITED STATES.
THE GFS AND THE ECMWF SOLUTIONS BEGIN TO DIFFER IN THE TUESDAY
NIGHT/WEDNESDAY TIME FRAME. THE GFS SOLUTION MOVES A PIECE OF
ENERGY EASTWARD ACROSS THE NORTHERN HIGH PLAINS AND GREAT LAKES
AND ALLOWS A COLD FRONT TO SLIDE SOUTHWARD THROUGH THE CENTRAL
PLAINS AND ACROSS NORTH TEXAS WEDNESDAY AFTERNOON/NIGHT. THE ECMWF
SOLUTION KEEPS THE WESTERN TROUGH MORE CONSOLIDATED AND DIGS IT
SOUTH...THUS KEEPING THE COLD FRONT NORTH OF THE REGION. WE WILL
SIDE CLOSER TO THE ECMWF SOLUTION BASED ON RECENT MODEL PERFORMANCE
WITH SIMILAR SYSTEMS. THEREFORE...WILL KEEP TEMPERATURES WARM ON
WEDNESDAY AND NOT BRING THE FRONT THROUGH NORTH TEXAS UNTIL
THURSDAY. WE WILL INCLUDE SOME WARM AIR ADVECTION SHOWERS IN THE
THE FORECAST WEDNESDAY NIGHT AND INCREASE RAIN/THUNDERSTORM
CHANCES WITH THE COLD FRONT ON THURSDAY. SOME POST FRONTAL RAIN IS
EXPECTED THURSDAY NIGHT AND FRIDAY AS THE UPPER TROUGH MOVES EAST
ACROSS THE REGION. TEMPERATURES FRIDAY MORNING SHOULD REMAIN ABOVE
32 DEGREES AND NO FREEZING RAIN OR WINTER PRECIPITATION IS
EXPECTED AT THIS TIME.
FRIDAY NIGHT AND SATURDAY WILL BE COLD WITH LOWS IN THE 20S AND
30S AND HIGHS FROM THE UPPER 30S TO THE MIDDLE 40S.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 50 68 45 68 48 / 0 0 0 0 5
WACO, TX 50 67 45 67 48 / 5 5 0 0 5
PARIS, TX 48 63 46 66 45 / 0 20 5 5 5
DENTON, TX 49 68 39 68 44 / 0 0 0 0 5
MCKINNEY, TX 48 66 42 65 43 / 0 10 0 0 5
DALLAS, TX 52 66 46 67 49 / 0 10 0 0 5
TERRELL, TX 51 65 46 67 47 / 0 20 0 0 5
CORSICANA, TX 52 65 48 68 50 / 0 10 0 0 5
TEMPLE, TX 52 68 46 72 49 / 5 5 0 0 5
MINERAL WELLS, TX 47 70 39 69 39 / 0 0 0 0 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
545 PM CST SAT NOV 30 2013
.AVIATION...
/00Z TAFS/
TIMING CIG TRENDS OVERNIGHT INTO EARLY SUNDAY WILL BE
CHALLENGING ALONG WITH BRIEF VSBY DROPS AROUND DAYBREAK WITH LOW
LEVEL WINDS SLIGHTLY VEERED.
VFR CIGS WILL CONTINUE ACROSS WACO AND AREAS SOUTH OF I-20 WHILE
DFW METRO AIRPORTS ENCOUNTER MAINLY SCT LOW CLOUDS WITH OCCASIONAL
BKN-OVC HIGH CLOUDINESS THROUGH MIDNIGHT.
AFTER PERUSAL OF LATEST BUFR SOUNDING DATA AND RUC SOUNDINGS...IT
APPEARS MVFR CIGS WILL NOT ARRIVE INTO DFW UNTIL BETWEEN 07-09Z
DUE TO THE VEERED LOW LEVEL WINDS THROUGH 925MB. WILL BRING MVFR
INTO WACO AN HOUR OR TWO SOONER WITHIN THE MORE MOIST LOW LEVEL
ENVIRONMENT. IFR CONDITIONS WITH BRIEF MVFR VSBYS LOOK POSSIBLE BY
DAYBREAK SUNDAY AT ALL TERMINALS WITH BOUNDARY LAYER WINDS ONLY
SSW 10-15 KTS. WACO WILL BE A TAD SLOWER TO RISE SUNDAY DUE TO
LIGHTER WINDS AND MORE MOISTURE VERSUS DFW. NEVERTHELESS...ALL
TERMINALS WILL RISE INTO MVFR BY MID-LATE MORNING AND BACK TO VFR
BY EARLY-MID AFTERNOON SUNDAY WITH MIXING/HEATING.
S/SW WINDS 5-9 KTS OVERNIGHT WILL INCREASE TO BETWEEN 10-15 KTS
ONCE AGAIN BY MIDDAY SUNDAY. NO PRECIPITATION IS EXPECTED.
05/
&&
.PREV DISCUSSION... /ISSUED 334 PM CST SAT NOV 30 2013/
A LOW LEVEL WARM AIR ADVECTION PATTERN WILL CONTINUE ACROSS NORTH
TEXAS TONIGHT WITH THE RETURN OF STRATUS OVERNIGHT. LOWS TONIGHT
WILL RANGE FROM THE MIDDLE 40S IN THE NORTH TO THE MIDDLE 50S IN
THE SOUTH.
A SHORT WAVE TROUGH WILL TRANSLATE ACROSS THE CENTRAL AND SOUTHERN
PLAINS ON SUNDAY AND ALLOW A WEAK COLD FRONT TO CROSS THE RED
RIVER. ALTHOUGH MOISTURE WILL BE LIMITED AND GENERALLY CONFINED TO
THE LOWEST LEVELS OF THE ATMOSPHERE. A FEW SHOWERS/STORMS MAY
ACCOMPANY THE SHORT WAVE...MAINLY ACROSS THE NORTHEASTERN ZONES
WHERE MOISTURE AND INSTABILITY WILL BE THE MOST FAVORABLE.
DRIER AND SLIGHTLY COOLER AIR WILL MOVE INTO NORTH TEXAS SUNDAY
NIGHT AS WEAK SURFACE HIGH PRESSURE TEMPORARILY BUILDS INTO THE
REGION. BY MONDAY...THE FRONT WILL BEGIN TO LIFT NORTHWARD IN
RESPONSE TO A DEEPENING SURFACE TROUGH ACROSS THE CENTRAL HIGH
PLAINS. LOW LEVEL WARM AIR ADVECTION WILL QUICKLY INCREASE MONDAY
NIGHT AND TUESDAY AS THE SURFACE TROUGH CONTINUES TO DEEPEN AHEAD
OF A DEVELOPING LONG WAVE TROUGH ACROSS THE WESTERN UNITED STATES.
THE GFS AND THE ECMWF SOLUTIONS BEGIN TO DIFFER IN THE TUESDAY
NIGHT/WEDNESDAY TIME FRAME. THE GFS SOLUTION MOVES A PIECE OF
ENERGY EASTWARD ACROSS THE NORTHERN HIGH PLAINS AND GREAT LAKES
AND ALLOWS A COLD FRONT TO SLIDE SOUTHWARD THROUGH THE CENTRAL
PLAINS AND ACROSS NORTH TEXAS WEDNESDAY AFTERNOON/NIGHT. THE ECMWF
SOLUTION KEEPS THE WESTERN TROUGH MORE CONSOLIDATED AND DIGS IT
SOUTH...THUS KEEPING THE COLD FRONT NORTH OF THE REGION. WE WILL
SIDE CLOSER TO THE ECMWF SOLUTION BASED ON RECENT MODEL PERFORMANCE
WITH SIMILAR SYSTEMS. THEREFORE...WILL KEEP TEMPERATURES WARM ON
WEDNESDAY AND NOT BRING THE FRONT THROUGH NORTH TEXAS UNTIL
THURSDAY. WE WILL INCLUDE SOME WARM AIR ADVECTION SHOWERS IN THE
THE FORECAST WEDNESDAY NIGHT AND INCREASE RAIN/THUNDERSTORM
CHANCES WITH THE COLD FRONT ON THURSDAY. SOME POST FRONTAL RAIN IS
EXPECTED THURSDAY NIGHT AND FRIDAY AS THE UPPER TROUGH MOVES EAST
ACROSS THE REGION. TEMPERATURES FRIDAY MORNING SHOULD REMAIN ABOVE
32 DEGREES AND NO FREEZING RAIN OR WINTER PRECIPITATION IS
EXPECTED AT THIS TIME.
FRIDAY NIGHT AND SATURDAY WILL BE COLD WITH LOWS IN THE 20S AND
30S AND HIGHS FROM THE UPPER 30S TO THE MIDDLE 40S.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 50 68 45 68 48 / 0 0 0 0 5
WACO, TX 52 67 45 67 48 / 5 5 0 0 5
PARIS, TX 48 63 46 66 45 / 0 20 5 5 5
DENTON, TX 49 68 39 68 44 / 0 0 0 0 5
MCKINNEY, TX 48 66 42 65 43 / 0 10 0 0 5
DALLAS, TX 52 66 46 67 49 / 0 10 0 0 5
TERRELL, TX 51 65 46 67 47 / 0 20 0 0 5
CORSICANA, TX 52 65 48 68 50 / 0 10 0 0 5
TEMPLE, TX 52 68 46 72 49 / 5 5 0 0 5
MINERAL WELLS, TX 47 70 39 69 39 / 0 0 0 0 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/79
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
520 PM CST SAT NOV 30 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CST SAT NOV 30 2013
THE MAIN FORECAST CONCERN FOR TONIGHT ARE THE CLOUDS FOR TONIGHT.
THE MODELS SHOW THAT THE MID AND HIGH CLOUDS CURRENTLY OVER THE
AREA WILL GRADUALLY SHIFT SOUTH AND THIN AS THEY MOVE INTO
NORTHEAST IOWA AND SOUTHWEST WISCONSIN LATE TONIGHT. MEANWHILE
ANOTHER AREA OF LOW CLOUDS CURRENTLY LOCATED OVER NORTHERN
MINNESOTA WILL MOVE SOUTH INTO WESTERN WISCONSIN AND PORTIONS OF
SOUTHEAST MINNESOTA. AS A RESULT...HAVE MANY AREAS MOSTLY CLOUDY
TONIGHT.
ON SUNDAY...WARM AIR ADVECTION AND WEAK TO MODERATE 285 TO 295K
ISENTROPIC LIFT WILL DEVELOP ACROSS THE AREA AS A WARM FRONT
MOVES NORTHEAST TOWARD THE AREA. THIS WILL KEEP SKIES MAINLY
CLOUDY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CST SAT NOV 30 2013
FROM SUNDAY NIGHT INTO MONDAY EVENING...THE 30.00Z MODELS KEEP THE
WEAK LOW PRESSURE MORE TOWARD THE DAKOTAS. THIS KEEPS THE WARM AIR
ADVECTION FURTHER WEST. AS A RESULT...SHIFTED THE SLIGHT SNOW
CHANCES WEST OF AN OELWEIN IOWA TO NEILLSVILLE WISCONSIN LINE.
FROM LATE MONDAY NIGHT INTO WEDNESDAY NIGHT...THE MODELS CONTINUE
TO STRUGGLE WITH A SHORT WAVE TROUGH EJECTING OUT AHEAD OF A
DEVELOPING LONG WAVE TROUGH OVER THE WESTERN UNITED STATES. SINCE
THE 30.00Z RUN...THE GFS CONTINUES TO BE THE STRONGEST AND THE
FASTEST AT MOVING THIS SYSTEM THROUGH WESTERN AND NORTHERN
MINNESOTA. THIS PUSHES THE ARCTIC COLD FRONT THROUGH THE AREA ON
TUESDAY NIGHT. 11 OF THE 12 GFS ENSEMBLE MEMBERS SUPPORT THE
OPERATIONAL GFS RUN. MEANWHILE THE ECMWF AND GEM HAS A MUCH WEAKER
WAVE MOVING THROUGH WESTERN AND NORTHERN MINNESOTA. THIS KEEPS THE
ARCTIC FRONT WEST OF THE FORECAST AREA UNTIL A STRONGER SHORT WAVE
TROUGH EJECTS ACROSS NORTHERN AND WESTERN MINNESOTA ON WEDNESDAY
NIGHT. AS A RESULT...BOTH THE TUESDAY NIGHT MINIMUM TEMPERATURE
AND WEDNESDAY MAXIMUM TEMPERATURE ARE WARMER. THE ECMWF ENSEMBLE
SUPPORTS THIS SLOWER SOLUTION. SINCE THE ECMWF TENDS TO DO BETTER
DURING THIS TIME FRAME...IT WAS THE CONSENSUS TO TREND THE
FORECAST TOWARD THE GEM AND ECMWF. WITH THERE NOT BEING TOO MUCH
OF A GULF CONNECTION UNTIL THE FRONT IS OFF TO THE EAST OF THE
FORECAST AREA...NOT EXPECTING TOO MUCH PRECIPITATION ALONG AND
AHEAD OF THIS FRONT. SOUNDINGS SUGGEST THAT THE PRECIPITATION WILL
START OFF AS SNOW OR RAIN LATE MONDAY NIGHT AND TUESDAY
MORNING...AND THEN TRANSITION TO MAINLY RAIN FROM TUESDAY
AFTERNOON INTO WEDNESDAY...AND THEN BACK OVER TO SNOW ON WEDNESDAY
NIGHT.
FROM THURSDAY NIGHT INTO FRIDAY MORNING...THE MODELS CONTINUE TO
SHOW THAT A SHORT WAVE TROUGH WILL MOVE FROM THE MID MISSISSIPPI
RIVER VALLEY INTO SOUTHEAST LOWER MICHIGAN. THE WARM CONVEYOR BELT
IN THE GEM AND ECMWF BRINGS SOME OF THE SNOW NORTHWARD INTO
EASTERN IOWA AND SOUTHERN AND EASTERN WISCONSIN. PREVIOUSLY THIS
PRECIPITATION WAS WELL SOUTHEAST OF THE FORECAST AREA. DUE TO THIS
SLIGHT DRIFT TO THE NORTHWEST... A SLIGHT CHANCE /15 TO 24
PERCENT/ OF SNOW WAS INTRODUCED TO THE FORECAST.
FROM FRIDAY INTO SATURDAY...THE TEMPERATURE FORECAST IS RATHER
TRICKY. THE ECMWF HAS 850 MB TEMPERATURES FALLING INTO THE -18C TO
-20C RANGE. MEANWHILE THE GFS IS EVEN COLDER WITH 850 MB
TEMPERATURES RANGING FROM -20 TO -22C. WHILE THESE TEMPERATURES ARE
2 TO 3 STANDARD DEVIATIONS BELOW NORMAL...THE HIGH TEMPERATURES AT
LA CROSSE HAVE ONLY /SINCE 1892 WHEN SNOW DEPTH RECORDS BEGAN/
FALLEN BELOW 10 DEGREES ONE TIME /DECEMBER 2 1976/ WHEN THERE WAS
LESS THAN AN INCH OF SNOW ON THE GROUND DURING THE FIRST TEN DAYS
OF DECEMBER. SNOW IS VERY CRITICAL WHEN LOOKING AT TEMPERATURES
APPROACHING RECORDS. WHEN LOOKING AT THE TEMPERATURE RECORDS FOR
ALL OF DECEMBER SINCE 1893...THERE HAS ONLY BEEN 2 OCCURRENCES OF
A RECORD COLD MAXIMUM /41 RECORDS/ BEING SET OR TIED WHEN THERE
WAS LESS THAN AN INCH OF SNOW ON THE GROUND. MEANWHILE...THERE HAS
NEVER BEEN A RECORD LOW TEMPERATURE /27 RECORDS/ SET WITH LESS
THAN INCH OF SNOW ON THE GROUND. AS A RESULT...VERY LEERY OF GOING
TOO COLD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 520 PM CST SAT NOV 30 2013
COLD FRONT HAS SAGGED SOUTH OF THE TAF SITES...WITH WINDS GENERALLY
LIGHT FROM THE NORTH TONIGHT THROUGH SUNDAY.
CURRENTLY...BAND OF MID LEVEL CLOUDS SLIDING SOUTHWARD ACROSS THE
REGION...MOSTLY 8-12 KFT. HOWEVER...FARTHER NORTH OVER NORTHERN
MN/LAKE SUPERIOR THERE WAS A LARGE AREA OF LOW STRATUS...ALSO MAKING
SOUTHWARD PROGRESS. MESO MODELS FAVOR KEEPING THIS CLOUD DECK
TOGETHER...WITH THE RAP13 REACHING KRST/KLSE TOWARD 12Z. THE GFS/NAM
NOT AS BULLISH ON BRINGING THE MVFR CLOUDS THIS FAR SOUTH. NOT
CONFIDENT IN TIMING AT THIS MOMENT...OR EVEN IF THE CLOUDS WILL MAKE
IT THIS FAR SOUTH...BUT WILL SIDE WITH THE RAP FOR NOW. SOUNDINGS
SUGGEST THAT THERE SHOULD BE ENOUGH MIXING FOR A DIURNAL INCREASE IN
CIG HEIGHT BY 18Z...AND POTENTIALLY BECOME SCT AS DRY AIR MIXES IN.
TOUGH CLOUD FORECAST. TRENDS WILL HAVE TO BE MONITORED CLOSELY AND
ADJUSTMENTS MADE AS NECESSARY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1125 PM CST THU NOV 28 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM CST THU NOV 28 2013
AT 3 PM...A LAKE INDUCED VORTICITY WAS LOCATED OVER THE APOSTLE
ISLANDS IN WESTERN LAKE SUPERIOR. MEANWHILE A SURFACE LOW WAS
LOCATED OVER EASTERN UPPER MICHIGAN. THIS LOW WAS PRODUCING WEAK
CYCLONIC FLOW ACROSS ACROSS WISCONSIN AND EAST CENTRAL MINNESOTA.
THIS CYCLONIC FLOW ALONG WITH STEEP 950-900 MB LAPSE RATES
/ASSOCIATED WITH A THERMAL TROUGH LOCATED FROM NORTHERN MINNESOTA
SOUTHEAST INTO EASTERN WISCONSIN/ IS HELPING MAINTAIN THESE
CLOUDS. THE 28.19Z RAP HAS A VERY GOOD HANDLE ON THESE CLOUDS AND
THEY SHOW THAT THEY WILL CONTINUE TO MOVE SOUTHEAST ACROSS MAINLY
OUR WISCONSIN COUNTIES AND THEN QUICKLY DISSIPATES THEM BETWEEN
28.01Z AND 28.03Z AS THE FLOW STARTS TO BECOME ANTICYCLONIC AND
THE 950-900 MB LAPSE RATES DECREASE.
FROM LATE TONIGHT INTO FRIDAY...THE 28.12Z MODELS CONTINUE TO
SHOW THAT WEAK WARM AIR ADVECTION WILL DEVELOP ABOVE 600 MB AS A
WEAK SHORT WAVE TROUGH APPROACHES THE REGION FROM THE CENTRAL
PLAINS. THIS WILL RESULT IN SOME MID TO HIGH CLOUDS ACROSS THE
AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM CST THU NOV 28 2013
ON FRIDAY NIGHT...THE 28.12Z MODELS CONTINUE TO SHOW THAT A STRONG
SHORT WAVE TROUGH WILL MOVE SOUTHEAST ACROSS SOUTHWEST ONTARIO.
MUCH OF THE PV ADVECTION ASSOCIATED WITH THIS SYSTEM STAYS WILL
NORTH OF THE FORECAST AREA. THERE IS WEAK TO MODERATE 285 TO 300K
ISENTROPIC LIFT ACROSS NORTHERN AND EASTERN WISCONSIN. THIS LOWERS
THE CONDENSATION PRESSURE DEFICITS TO LESS 40 MB. MEANWHILE AT THE
285 AND 290K ISENTROPIC SURFACES YOU STILL NEED 100 TO 200 MB
OF LIFT FOR SATURATION. AS A RESULT...IT IS NOT LOOKING PROMISING
FOR ANY PRECIPITATION ACROSS TAYLOR AND NORTHERN CLARK COUNTY IN
NORTH CENTRAL WISCONSIN. HOWEVER WITH THE ECMWF...GEM...AND NAM
STILL INDICATING A POSSIBILITY. JUST KEPT A SLIGHT CHANCE /LESS
THAN 20 PERCENT/ ACROSS THIS AREA. BUFKIT SOUNDINGS CONTINUE TO
SHOW NO ICE...SO IF PRECIPITATION DOES INDEED OCCURS IT WOULD BE
IN THE FORM OF FREEZING DRIZZLE.
ON SATURDAY NIGHT...WEAK TO MODERATE WARM AIR ADVECTION AND STRONG
290 TO 300K ISENTROPIC LIFT DEVELOP ACROSS THE AREA AS A STRONG
SHORT WAVE TROUGH MOVES ACROSS THE REGION. THE 290-300K ISENTROPIC
CONDENSATION PRESSURE DEFICITS DROP TO LESS THAN 30 MB...SO WE
WILL LIKELY SEE CLOUDS WITH THIS WAVE. HOWEVER...THE 285K
CONDENSATION DEFICITS REMAIN IN THE 100 TO 200 MB RANGE...SO NOT
EXPECTING ANY PRECIPITATION WITH THIS WAVE.
FROM SUNDAY NIGHT INTO MONDAY...THE MODELS CONTINUE TO STRUGGLE
WITH THE TIMING OF A SHORT WAVE TROUGH COMING OUT AHEAD OF THE
DEVELOPING LONG WAVE TROUGH IN THE WESTERN UNITED STATE. BOTH THE
GEM AND ECMWF BRING A WAVE AHEAD OF THIS SYSTEM. MEANWHILE THE GFS
DOES NOT. AS AS RESULT...THE GEM AND ECMWF PRODUCES SOME LIGHT
PRECIPITATION ACROSS THE AREA. MEANWHILE THE GFS KEEPS THE AREA
DRY. SINCE THE MODELS HAVE BEEN CONSISTENT...JUST STAYED WITH THE
SLIGHT CHANCES THAT THE ALL BLEND PROVIDED.
FROM MONDAY NIGHT THROUGH THURSDAY...THE MODELS CONTINUE TO
STRUGGLE WITH THE EVOLUTION OF A LONG WAVE TROUGH OVER THE WESTERN
UNITED STATES. DUE TO THIS...THERE HAS BEEN A VARIETY OF DIFFERENT
LOW PRESSURE TRACKS FROM THE NORTHERN PLAINS EAST INTO THE GREAT
LAKES. THIS SYSTEM HAS THE POTENTIAL OF PRODUCING A WINTER STORM
SOMEWHERE ACROSS THE REGION...BUT WHERE IS VERY UNCERTAIN...SO
JUST STAYED WITH THE ALL BLEND FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 1125 PM CST THU NOV 28 2013
CLOUDS HAVE FINALLY DIMINISHED...AND EXPECT SKC/SCT CONDITIONS FOR THE
REST OF THE NIGHTTIME HOURS WITH LIGHT TO VRB WINDS. WINDS WILL
INCREASE AND SHIFT TO THE SOUTH/SOUTHEAST A FEW HOURS AFTER DAYBREAK
FRIDAY AS HIGH PRESSURE EXITS OVER THE EASTERN GREAT LAKES. SHOULD
SEE SOME HIGH/MID LEVEL CLOUDS BY THIS TIME...MOSTLY IN THE 150-250
KFT RANGE.
A COUPLE FORECAST CONCERNS FOR FRIDAY NIGHT. FIRST IS THE POTENTIAL
FOR MVFR CIGS AT KLSE. NAM SUGGESTS LOW LEVEL MOISTURE WILL BE ON
THE INCREASE IN THE EVENING...LIKELY RESULTING IN A 1500-2500 FT
DECK. THE GFS IS DRIER IN THE LOW LAYERS...AND STAYS VFR. THERE WAS
A LARGE SWATH OF MVFR CIGS ACROSS THE DAKOTAS THU MORNING...IN A
REGION OF GOOD LOW LEVEL ISENTROPIC UPGLIDE...WHICH WILL BE SHIFTING
ACROSS THE LOCAL AREA FRIDAY NIGHT. HOWEVER...THE PRESSURE GRADIENT
WAS ALSO WEEK ACROSS THE DAKOTAS...WHILE LOCALLY THE PRESSURE
GRADIENT WILL STAY RELATIVELY TIGHT...WITH WINDS AROUND 10 KTS.
STILL...WITH INCREASING MOISTURE/TRANSPORT UNDER AN
INVERSION...WOULD SEEM TO BE A DECENT SETUP FOR SOME LOW STRATUS
FORMATION. CONFIDENCE SHAKY AT THE MOMENT...BUT ENOUGH TO GO ON TO
ADD A MENTION FOR KLSE. THE OTHER CONCERN IS THE POTENTIAL FOR LLWS
FRIDAY NIGHT. BUFKIT SOUNDINGS SUGGESTING AROUND 40 KTS BY 2 KFT
FRIDAY EVENING...AND SFC WINDS DEPENDING...LLWS CRITERIA COULD BE
MET. WILL LEAVE OUT OF THE FORECAST FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
944 PM MST SAT NOV 30 2013
.UPDATE...
ISSUED AT 940 PM MST SAT NOV 30 2013
HAVE ADJUSTED AREAS OF FOG FOR TONIGHT THROUGH SUNDAY WITH FOG
MAINLY IN THE VALLEY BOTTOMS AND ALONG THE SLOPES OF THE WESTERN
MOUNTAINS. SOUNDINGS OVER THE LAST 36HRS AT GJT SHOW THE STRATUS
LAYER NEAR 7500FT SO HAVE ADDED FOG TO THE SLOPES DEFINED BY
7-8KFT. THE NEW NAM IS NOT RECOGNIZING THE BOUNDARY LAYER FOG SO
ITS FORECAST TEMPS ARE TOO HIGH FOR THE WESTERN VALLEY SITES. THE
03Z RAP IS CAPTURING THE FOG LAYER BUT ERODES BY SUNDAY AFTERNOON.
WITH WARM ADVECTION ALOFT RETURNING THEN...THE STRATUS LAYER IS
EXPECTED TO PERSIST.
IN THE BIGGER PICTURE...THE NAM IS STILL PRODUCING ONLY LIGHT SNOW
ACCUMULATIONS MAINLY IN THE ELKHEAD AND ZIRKELS TONIGHT THROUGH
SUNDAY. THE NAM12 IS PRODUCING UP TO 5 INCHES. THIS LOOKS A BIT
HEAVY HANDED WITH LITTLE DYNAMICAL FORCING OR WEAK COOL ADVECTION.
THE DENDRITIC CRYSTAL GROWTH REGION DOES NOT FULLY SATURATE SO
OROGRAPHICS WOULD BE THE MAIN MECHANISM.
MONDAY-MONDAY NIGHT...THE 00Z NAM IS MORE ROBUST AND FAST WITH
THE APPROACHING TROUGH. SIGNIFICANT SNOW STARTS ACROSS THE NORTH
MONDAY NIGHT AND SPREADS ACROSS THE CWA ON TUESDAY. WILL EVALUATE
OVERNIGHT FOR A POTENTIAL WATCH.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 427 PM MST SAT NOV 30 2013
INVERSIONS WHICH FORMED IN THE WAKE OF LAST WEEK/S STORM REMAINED
IN PLACE TODAY. AS A RESULT...LOW CLOUDS AND FOG CONTINUED TO
IMPACT VALLEYS BELOW 6500 FEET ASL AND ADJACENT MOUNTAINS TO
BETWEEN 8000 AND 8500 FEET. DAYTIME WARMING ENHANCED BY CLEAR
SKIES ON THE EDGE OF THE STRATUS FIELD WILL CONTINUE TO ERODE THE
STRATUS THROUGH THE AFTERNOON...BUT EXPECT CLOUDS WILL AGAIN
SPREAD UPVALLEY WITH FOG REFORMING IN RESPONSE TO COOLING
TEMPERATURES OVERNIGHT.
SOME QUESTION AS TO WHETHER THE APPROACHING SHORTWAVE TROUGH IN
THE NORTHWESTERLIES WILL ALLOW FOR MIXING OF LOWER LEVELS LATE
TONIGHT. WAA AHEAD OF THIS FEATURE SUGGESTS OTHERWISE AND SURFACE
PRESSURE GRADIENT WEAK AT BEST. CONSEQUENTLY...WILL LEAVE LOW
CLOUDS AND CONTINUE WITH FORECAST FOR FOG. FOR THE NORTHERN
MOUNTAINS...LIFT AND MOISTURE ASSOCIATED WITH THE SHORTWAVE MAY
BEGIN TO GENERATE SOME LIGHT SNOW AFTER MIDNIGHT.
SNOW WILL INCREASE OVER THE ELKHEAD AND PARK RANGES EARLY SUNDAY
AS THE SHORTWAVE SWEEPS OVER THE AREA. THERE WILL BE A BRIEF
PERIOD OF DYNAMIC LIFT WITH THE WAVES PASSAGE SUNDAY MORNING.
THEREAFTER...FROM SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...
OROGRAPHIC LIFT WILL BECOME THE DOMINANT MECHANISM FOR SNOW AS
STRONG WEST TO WEST-NORTHWEST WINDS FROM 20 TO 30 MPH BUFFET THE
AREA. THE 12Z/SAT BUFR SOUNDING FOR KHDN INDICATED THAT A
SATURATED DENDRITIC GROWTH REGION WILL ENHANCE SNOWFALL SUNDAY
MORNING...BUT QUICKLY DRIES AND RISES WITH TROUGH PASSAGE BY
MIDDAY AS TEMPERATURE ADVECTION SHIFTS FROM WEAKLY COLD AIR
ADVECTIVE...TO NEUTRAL SUNDAY AFTERNOON...THEN BECOMES WARM AIR
ADVECTIVE SUNDAY EVENING. THOUGH WAA WILL LIMIT ACCUMULATIONS
BELIEVE ELKHEADS AND SOME OF THE PARK RANGE COULD SEE AMOUNTS
CLOSER TO NAM GUIDANCE OF 3 TO 6 INCHES SUNDAY AND SUNDAY NIGHT...
BUT MAINLY OVER HIGHER EXPOSED PEAKS.
IT/S DOUBTFUL THAT THIS ACTIVITY WILL HAVE MUCH AFFECT ON THE
VALLEY INVERSIONS DISCUSSED PREVIOUSLY AND THEREFORE WILL
CONTINUE TO FORECAST LOW CLOUDS AND FOG FOR THOSE AREAS.
MEANWHILE...THE SOUTHERN MOUNTAINS MAY SEE SOME MID AND HIGH
CLOUDS BUT ARE UNLIKELY TO GET SNOWFALL.
AS FOR TEMPERATURES...SEE NO REASON TO STRAY FROM PERSISTENCE
FORECAST THROUGH THE NEXT THREE PERIODS. THE ONLY EXCEPTION IS
ACROSS THE NORTH WHERE INCREASED LOW AND MID CLOUDS SHOULD BRING
SLIGHTLY WARMER LOWS SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 427 PM MST SAT NOV 30 2013
OROGRAPHIC SNOWFALL ALONG THE NORTHERN DIVIDE WILL TAPER OFF ON
MONDAY AS THE FLOW TRANSITIONS FROM NORTHWEST EARLY IN THE DAY TO
WESTERLY BY EVENING. THIS SHIFT IN THE FLOW IS THE RESULT OF THE
NEXT STORM SYSTEM DROPPING INTO THE PACIFIC NORTHWEST THROUGHOUT
THE DAY. AS THIS HAPPENS THE GRADIENT WILL TIGHTEN...MAINLY OVER
THE NORTH. OTHER THAN BREEZES OVER THE HIGHER TERRAIN AND
NORTH...AND A FEW LINGERING SNOW SHOWERS OVER THE NORTHERN
DIVIDE...MONDAY WILL GENERALLY BE A QUIET DAY.
THEN THE BIG CHANGE IN CONDITIONS WILL BEGIN TO TAKE PLACE ON
TUESDAY AS THE NORTHWEST UPPER LOW PRESSURE SYSTEM AND ITS
ASSOCIATED SURFACE COLD FRONT APPROACH FROM THE NORTHWEST. THIS
MUCH ADVERTISED STORM SYSTEM IS STILL ON TRACK TO BRING
SIGNIFICANT WEATHER TO THE FORECAST AREA BEGINNING LATE TUE
THROUGH WED...WITH COLD TEMPERATURES AND THE POTENTIAL FOR
CONTINUED UNSETTLED CONDITIONS THROUGH THE END OF THE LONG TERM
PERIOD.
THE FLOW BECOMES SOUTHWEST MON NIGHT INTO TUE AND STRENGTHENS AS
THE UPPER LOW TRACKS INTO ID. IN ADDITION...THE STRONG SURFACE
COLD FRONT WILL REACH OUR NORTH/NORTHWEST EDGE LATE IN THE
AFTERNOON TO THE EVENING...THEN PROCEED SOUTH/SOUTHEAST OVERNIGHT.
IN THE PRE-FRONTAL ENVIRONMENT SOUTHWEST WINDS WILL BECOME STRONG
ACROSS THE MOUNTAINS EARLY IN THE DAY...THEN WILL MIX INTO THE
VALLEYS BY THE AFTERNOON. THE GFS IS QUITE A BIT FASTER THAN THE
NAM12 AND ECMWF WITH THE TIMING OF THIS FRONT. IT BRINGS THE FRONT
INTO NORTHWEST CO/NORTHEAST UT IN THE MORNING...WHERE IT STALLS
NORTH OF THE TAVAPUTS/FLATTOPS THROUGH THE AFTERNOON/EVENING.
WHILE I MOSTLY DISCOUNTED THE GFS TIMING DUE TO LACK OF AGREEMENT
AND CONTINUITY...IF IT WERE TO VERIFY IT COULD RESULT IN
SIGNIFICANT SNOW OVER THE NORTH THROUGH TUE. GENERALLY FOLLOWING
THE NAM AND ECMWF...POPS GRADUALLY TREND UPWARDS THROUGH TUE OVER
THE NORTH...THEN INCREASE AND SPREAD SOUTH OVERNIGHT. WHILE THE
UPPER LOW CENTER IS PROGGED REMAIN TO OUR NORTH...AT LEAST A
COUPLE OF SHORTWAVES WILL SWING AROUND ITS BASE AND ACROSS OUR
FORECAST AREA. WED PROMISES TO BE THE MOST ACTIVE DAY AS THE FIRST
SHORTWAVE AND AN ASSOCIATED 120KT JET PASS OVERHEAD BRINGING GOOD
DYNAMICS AND UPPER SUPPORT TO A SATURATED AIR MASS. PRECIPITATION
WILL MOSTLY BE SNOW IN THE WAKE OF THE STRONG SURFACE FRONT AND BY
WED EVENING ALL AREAS WILL SEE SNOW IN THE COLD ADVECTION BEHIND
THE SHORTWAVE/COLD FRONT.
ANOTHER SHORTWAVE WILL SWING AROUND THE LOW THU/THU NIGHT BRINGING
EVEN COLDER AIR OVER THE REGION...-32C/500MB AND -20C/700MB. THIS
COLD AIR MASS WILL JUST NOT BE ABLE TO HOLD MUCH MOISTURE...AND
MODELS INDICATE A MARKED DOWNTURN IN POPS. HOWEVER MODELS OFTEN
DRY THINGS OUT TOO FAST. THEREFORE KEPT AT LEAST
CHANCE/MOUNTAINS...SLIGHT CHANCE/VALLEYS THROUGH THE DAY ON THU.
THEN POPS DIMINISH THROUGH FRI AND SAT. HOWEVER COLD CONDITIONS
AND GENERAL TROUGHINESS WILL PERSIST OVER THE REGION THROUGH THE
END OF THE WEEK. SO UNSETTLED CONDITIONS ARE POSSIBLE THROUGH SAT.
FRI AND SAT MORNINGS ARE PROMISING TO BE THE COLDEST SO FAR THIS
SEASON WITH TEMPS AT MANY LOCATIONS DROPPING INTO THE SINGLE
DIGITS OR BELOW ZERO...WITH LOWER TEENS ELSEWHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 940 PM MST SAT NOV 30 2013
STRATUS AND LIGHT FOG ARE EXPECTED TO CONTINUE OVERNIGHT...EXPANDING
EASTWARD OVERNIGHT TO INCLUDE CEZ-DRO. THE ONLY EXCEPTION TO THIS
RULE WILL BE ACROSS THE NORTH...WHERE AN UPPER LEVEL DISTURBANCE
MAY WEAKEN INVERSIONS CAUSING CLOUDS TO LIFT WHILE FOG DECREASES
IN COVERAGE AND INTENSITY. MVFR CIGS WILL LINGER IN THE LOWER
VALLEYS BEFORE EXPANDING EAST WHILE PATCHY FOG DEVELOPS. FOG WILL
SPREAD...BECOMING LOCALLY DENSE LATE TONIGHT AND INTO SUNDAY
MORNING RESULTING IN AREAS OF IFR VSBY AND CIGS. AREAS EAST WILL
HAVE VFR CONDITIONS THROUGHOUT THE NEXT 24 HOURS. THE ONLY
EXCEPTION BEING THE NORTHERN COLORADO MOUNTAINS WHERE THE
DISTURBANCE MENTIONED PREVIOUSLY WILL BRING NUMEROUS SNOW SHOWERS
RESULTING IN MOUNTAIN OBSCURATIONS OF THE ELKHEAD AND PARK RANGES
ON SUNDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JOE
SHORT TERM...NL
LONG TERM...EH
AVIATION...NL/JOE
AREA FORECAST DISCUSSION
NWS MIAMI FL
319 AM EST SUN DEC 1 2013
DISCUSSION...
HIGH PRESSURE TO THE NORTH CONTINUES TO BRING NORTHEASTERLY FLOW
TO SOUTH FLORIDA. HOWEVER, THE HIGH WILL BEGIN TO WEAKEN TODAY,
ALLOWING THE WINDS TO BECOME LIGHTER. THERE IS STILL A FEW SHOWERS
OVER THE ATLANTIC WATERS. CURRENTLY, THEY ARE NOT IMPACTING THE
CWA, BUT STILL HAVE A SLIGHT CHANCE IN THE FORECAST. THE HRRR DOES
SHOW SOME ISOLATED SHOWERS OVER THE ATLANTIC COAST METRO AREAS
THIS AFTERNOON, SO BROUGHT SLIGHT CHANCE POPS SOMEWHAT MORE WEST.
MODELS STILL SHOWING A VERY WEAK FRONT PUSHING SOUTH THROUGH SOUTH
FLORIDA TOMORROW, BUT LOOKS BARELY DISCERNIBLE IN THE MODELS. GFS
HAS HIGH PRESSURE BUILDING OVER THE FLORIDA PENINSULA BY 00Z
TUESDAY WITH NO PRECIPITATION AT ALL. THE ECMWF IS SIMILAR, BUT
ABOUT 6 HOURS SLOWER WITH MORE BROAD WEAK HIGH PRESSURE BUILDING.
EITHER WAY. THE BEST EVIDENCE OF THIS FRONT WILL LIKELY BE A WEAK
WINDS SHIFT TOMORROW. BUT, LEFT A SLIGHT CHANCE OF SHOWERS ACROSS
THE CWA FOR THE AFTERNOON HOURS. BUT, GIVEN CURRENT MODEL RUNS,
COULD DEFINITELY SEE THIS BEING PULLED OUT OF THE FORECAST LATER
TODAY.
AFTER TOMORROW, IT IS HIGH PRESSURE FOR THE REMAINDER OF THE
FORECAST PERIOD. THE AIR MASS WILL WARM VERY SLIGHTLY THROUGH THE
WEEK, WITH PERHAPS A FEW LIGHT COASTAL SHOWERS POSSIBLE,
ESPECIALLY IN THE OVERNIGHT HOURS.
AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY
MORNING HOURS. HOWEVER...AN AREA OF CLOUDINESS AND EMBEDDED
SHOWERS IS MOVING WESTWARD INTO THE LOCAL ATLANTIC WATERS AND A FEW
SHOWERS COULD IMPACT THE EAST COAST TERMINALS FROM TIME TO TIME.
ONLY PASSING SHOWERS EXPECTED BUT WILL AMEND IF ANY VIS/CEILING
RESTRICTIONS OCCUR BUT NOT EXPECTED. WINDS ACROSS THE EAST COAST
TERMINALS STARTING TO BECOME LIGHT AND VARIABLE WITH AN OFF SHORE
DRAINAGE FLOW BEGINNING.
MARINE...
HIGH PRESSURE TO THE NORTH WILL WEAKEN TODAY, BUT STILL KEEP
EASTERLY FLOW OVER THE COASTAL WATERS. THE WEAKER WINDS WILL
RESULT IN SEAS CONTINUING TO SUBSIDE TODAY. GIVEN THIS ALL
ADVISORIES AND CAUTION STATEMENTS HAVE BEEN CANCELLED. THERE IS A
SLIGHT CHANCE OF SHOWERS OVER THE NEXT COUPLE OF DAYS AS A VERY
WEAK COLD FRONT SLIDES ACROSS THE AREA TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 62 78 61 / 20 10 10 -
FORT LAUDERDALE 80 64 78 63 / 20 10 10 -
MIAMI 80 64 79 63 / 20 10 10 -
NAPLES 78 63 76 62 / - - 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
315 AM EST SUN DEC 1 2013
.DISCUSSION...
HIGH PRESSURE TO THE NORTH CONTINUES TO BRING EAST TO
NORTHEASTERLY FLOW TO SOUTH FLORIDA. HOWEVER, THE HIGH WILL BEGIN
TO WEAKEN TODAY, ALLOWING THE WINDS TO BECOME LIGHTER. THERE IS
STILL A FEW SHOWERS OVER THE ATLANTIC WATERS. CURRENTLY, THEY ARE
NOT IMPACTING THE CWA, BUT STILL HAVE A SLIGHT CHANCE IN THE
FORECAST. THE HRRR DOES SHOW SOME ISOLATED SHOWERS OVER THE
ATLANTIC COAST METRO AREAS THIS AFTERNOON, SO BROUGHT SLIGHT
CHANCE POPS SOMEWHAT MORE WEST.
MODELS STILL SHOWING A VERY WEAK FRONT PUSHING SOUTH THROUGH SOUTH
FLORIDA TOMORROW, BUT LOOKS BARELY DISCERNIBLE IN THE MODELS. GFS
HAS HIGH PRESSURE BUILDING OVER THE FLORIDA PENINSULA BY 00Z
TUESDAY WITH NO PRECIPITATION AT ALL. THE ECMWF IS SIMILAR, BUT
ABOUT 6 HOURS SLOWER WITH MORE BROAD WEAK HIGH PRESSURE BUILDING.
EITHER WAY. THE BEST EVIDENCE OF THIS FRONT WILL LIKELY BE A WEAK
WINDS SHIFT TOMORROW. BUT, LEFT A SLIGHT CHANCE OF SHOWERS ACROSS
THE CWA FOR THE AFTERNOON HOURS. BUT, GIVEN CURRENT MODEL RUNS,
COULD DEFINITELY SEE THIS BEING PULLED OUT OF THE FORECAST LATER
TODAY.
AFTER TOMORROW, IT IS HIGH PRESSURE FOR THE REMAINDER OF THE
FORECAST PERIOD. THE AIR MASS WILL WARM VERY SLIGHTLY THROUGH THE
WEEK, WITH PERHAPS A FEW LIGHT COASTAL SHOWERS POSSIBLE,
ESPECIALLY IN THE OVERNIGHT HOURS.
&&
.AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY
MORNING HOURS. HOWEVER...AN AREA OF CLOUDINESS AND EMBEDDED
SHOWERS IS MOVING WESTWARD INTO THE LOCAL ATLANTIC WATERS AND A FEW
SHOWERS COULD IMPACT THE EAST COAST TERMINALS FROM TIME TO TIME.
ONLY PASSING SHOWERS EXPECTED BUT WILL AMEND IF ANY VIS/CEILING
RESTRICTIONS OCCUR BUT NOT EXPECTED. WINDS ACROSS THE EAST COAST
TERMINALS STARTING TO BECOME LIGHT AND VARIABLE WITH AN OFF SHORE
DRAINAGE FLOW BEGINNING.
&&
.MARINE...
HIGH PRESSURE TO THE NORTH WILL WEAKEN TODAY, BUT STILL KEEP
EASTERLY FLOW OVER THE COASTAL WATERS. THE WEAKER WINDS WILL
RESULT IN SEAS CONTINUING TO SUBSIDE TODAY. GIVEN THIS ALL
ADVISORIES AND CAUTION STATEMENTS HAVE BEEN CANCELLED. THERE IS A
SLIGHT CHANCE OF SHOWERS OVER THE NEXT COUPLE OF DAYS AS A VERY
WEAK COLD FRONT SLIDES ACROSS THE AREA TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 62 78 61 / 20 10 10 -
FORT LAUDERDALE 80 64 78 63 / 20 10 10 -
MIAMI 80 64 79 63 / 20 10 10 -
NAPLES 78 63 76 62 / - - 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
252 AM CST SUN DEC 1 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 06Z...
* MVFR CIGS LIKELY DEVELOPING SUNDAY MORNING AND LINGERING THROUGH
THE DAY.
RATZER
//DISCUSSION...UPDATED 06Z...
WEAK LOW PRESSURE WAS OVER NORTHERN LOWER MICHIGAN LATE THIS
EVENING...WITH A WEAK/DIFFUSE COLD FRONT TRAILING ACROSS SOUTHERN
WI. THIS FRONT WILL CONTINUE TO MOVE SOUTHEAST ACROSS THE TERMINALS
DURING THE EARLY MORNING HOURS...WITH WINDS SHIFTING FROM LIGHT
WEST-SOUTHWEST TO NORTHERLY. WINDS WILL BECOME MORE NORTH-
NORTHEAST LATER IN THE MORNING...THOUGH WITH SPEEDS GENERALLY LESS
THAN 10 KT. LARGE AREA OF MVFR STRATUS TRAILING THE FRONT ACROSS
NORTHERN WI/MI...THOUGH MAKING SLOW SOUTHWARD PROGRESS PER GOES IR
SATELLITE IMAGERY. HIGH-RES RAPID REFRESH ENSEMBLE GUIDANCE
INDICATES MVFR CIGS ARRIVE AT ORD/MDW DURING THE LATE MORNING
HOURS AS WINDS TURN A BIT MORE NORTH-NORTHEAST. LITTLE CHANGE IN
CONDITIONS THEN ANTICIPATED THROUGH THE DAY/EARLY EVENING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN MVFR DEVELOPING SUNDAY BUT LOW
CONFIDENCE IN TIMING.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...MVFR PROBABLE. CHANCE OF -SN.
MONDAY NIGHT INTO TUESDAY...MVFR CIGS POSSIBLE.
WEDNESDAY...MVFR CIGS LIKELY WITH IFR POSSIBLE. CHANCE OF -RA.
THURSDAY AND FRIDAY...MVFR CIGS LIKELY WITH IFR POSSIBLE. CHANCE OF
-SN
IZZI
&&
.MARINE...
252 AM CST
MAIN MARINE FORECAST CONCERNS FOCUS ON DEVELOPMENT OF STRONG LOW
PRESSURE OVER THE PLAINS MONDAY-TUESDAY...WHICH THEN IS EXPECTED TO
LIFT NORTHEAST ACROSS THE NORTHERN LAKES ON WEDNESDAY. THERE
CONTINUES TO BE SOME SPREAD IN MODEL SOLUTIONS WITH THE DEPTH...
TRACK AND TIMING OF THE LOW.
WEAK LOW PRESSURE WAS OVER LOWER MICHIGAN STATE EARLY THIS
MORNING...WITH A COLD FRONT TRAILING ACROSS SOUTHERN LAKE MICHIGAN.
THE LOW WILL CONTINUE TO TRACK EAST ACROSS THE EASTERN LAKES THROUGH
THIS EVENING...WITH THE FRONT PUSHING SOUTHEAST OF LAKE MICHIGAN
LATER THIS MORNING. WEAK HIGH PRESSURE RIDGING WILL THEN MOVE ACROSS
THE WESTERN LAKES LATER TODAY/TONIGHT...DRIFTING SLOWLY OFF TO THE
EAST ON MONDAY. WITH A RELATIVELY WEAK PUSH TO THE FRONT TODAY...
WINDS WILL SHIFT TO THE NORTH AT GENERALLY LESS THAN 15 KT.
FORECAST MODELS CONTINUE TO DEPICT AN AREA OF LOW PRESSURE
DEVELOPING ACROSS THE HIGH PLAINS BY EARLY MONDAY...WHICH THEN
DEEPENS ACROSS THE CENTRAL PLAINS MONDAY NIGHT. VARIOUS MODEL
SOLUTIONS CONTINUE TO SHOW DIFFERENCES WITH THE EVOLUTION OF THIS
LOW THROUGH MID-WEEK...THOUGH THERE IS SOME CONSENSUS IN LIFTING THE
LOW NORTHEAST ACROSS THE NORTHERN GREAT LAKES WEDNESDAY. GENERALLY
HAVE CONTINUED TO FOLLOW THE SLOWER SOLUTIONS OF THE ECMWF/GEM/UKMET
WITH THIS SYSTEM...THOUGH WILL HAVE TO SEE SOME OF THE DIFFERENCES
IRONED OUT BEFORE CONFIDENCE INCREASES IN DETAILS OF STRENGTH/TRACK
AND TIMING. IT DOES APPEAR THAT THE POTENTIAL EXISTS FOR SOUTHEAST
30-35 KT WINDS AHEAD OF THE LOW LATE TUESDAY INTO WEDNESDAY...AND
WEST GALES LATER WEDNESDAY INTO THURSDAY WITH THE PASSAGE OF THIS
STORM. STILL 3-4 DAYS OUT SO WILL NOT HAVE ANY HEADLINES...THOUGH
WILL MENTION POSSIBLE GALES IN FORECAST FOR THIS PERIOD.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
248 AM CST Sun Dec 1 2013
.DISCUSSION...
ISSUED 248 AM CST Sun Dec 1 2013
Main forecast challenge focuses on departing storm system for the
middle and end of the week...and whether or not it will produce
any wintry precipitation across central Illinois.
SHORT TERM...Today through Tuesday
Weak cold front currently across northern Illinois will sink
southward today, eventually becoming stationary along the Ohio
River by evening. Front will be accompanied by little in the way
of sensible weather other than a shift in the wind. Low-level
moisture seen on IR/fog satellite across southeast Missouri/far
southern Illinois is progged by HRRR to remain mostly south of
I-70 today, while patchy mid-level clouds over Iowa into far
northern Illinois stay mostly north of the area. End result will
be mostly sunny skies until later this afternoon when clouds begin
to approach from the northwest. High temperatures will be bit
cooler behind the cold front, ranging from the middle 40s far
northwest around Galesburg to the lower 50s south of I-70.
Boundary will remain in place along the Ohio River through Monday,
before lifting back northward in response to rising upper-level
heights Monday night into Tuesday. Models continue to show a
subtle short-wave rippling eastward out of the Plains late Sunday
night into Monday that could interact with the front to produce
scattered light showers. Forecast soundings remain dry at
low-levels: however, think forcing will be strong enough to
mention a slight chance for showers on Monday. As front lifts
northward, rain chances will shift into the southern Great Lakes
on Tuesday. Brisk southerly winds south of the departing warm
front will bring much warmer air into the region, with Tuesday
afternoon highs reaching the lower to middle 50s.
LONG TERM...Wednesday through Saturday
Forecast becomes more challenging in the extended, as upper low
currently over northwest British Columbia drops southward and
carves a deep trough across the western CONUS by the middle of the
week. Downstream ridging will place the Midwest/Great Lakes in a
broad southwesterly flow pattern, leading to increased precip
chances Wednesday into Thursday. Models have been struggling with
the evolution of a surface low pressure system and its associated
cold front for the past several runs: however, the 00z DEC 1 run
seems to be coming into better agreement. While GFS remains a fast
outlier, the latest ECMWF has sped up the front quite a bit.
Following an ECMWF/GEM consensus yields FROPA across central
Illinois on Wednesday followed by sharply colder conditions for
the end of the week. Main question will be how much precip will
hold back in the colder airmass Thursday and possibly Friday.
Previous runs of the ECMWF had featured quite a bit of wintry
precip Thursday night into Friday as a secondary wave of low
pressure tracked along the departing front. While it still shows the
potential for wintry precip, it has backed off/shifted E/SE with
its latest solution. GEM seems to be the most consistent model
over the past couple of days, so have trended toward its solution.
With cold front passing on Wednesday, will mention a chance for
showers. After FROPA, precip will largely shut off Wednesday
night, before a wave of low pressure tracking from the lower
Mississippi River Valley into the Ohio River Valley brings a
renewed round of precip primarily across the eastern half of the
KILX CWA on Thursday/Thursday night. Have focused highest POPs
along/east of I-57 for both Thursday and Thursday night, tapering
down to just slight chances further west along/west of the
Illinois River. Precip type during the day Thursday will be rain
across the east, with a rain/snow mix along I-55 and mostly light
snow in the Illinois River Valley. As deeper layer of cold air
arrives, precip will change to light snow across the board
Thursday night, with a light accumulation possible. After that,
will hold on to low chance POPs for snow across the far E/SE on
Friday, although if trends continue, these may need to be dropped
entirely. Main weather story for the end of the week will be the
much colder conditions. Highs by Friday and Saturday will only be
in the 20s, with overnight lows in the single digits and teens.
Barnes
&&
.AVIATION...
ISSUED 1118 PM CST Sat Nov 30 2013
VFR conditions will prevail at all sites next 24hrs. Becoming
increasing obvious that light fog will not be developing
overnight. However, still thinking there is some lower level
moisture there and that some light fog still possible, but only as
a TEMPO group in the early morning hours from about 10-13z. Also
vis will not drop that much so TEMPO vis will be MVFR at 3-5SM.
Besides that, skies will be clear overnight and through tomorrow.
Then mid clouds around 12kft will advect into the area for the
evening hours. A weak front will move through the area overnight,
which should have winds switching to southwest and then west.
However, speeds are so light that variable direction is best
overnight. Then winds should be north to northwest after FROPA and
then become northeast during the evening hours.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
359 AM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO CROSS THE STATE TODAY AND REDEVELOP IN
THE GULF OF MAINE TONIGHT, PASSING WELL E OF THE REGION ON MONDAY.
ANOTHER LOW MAY AFFECT THE REGION FROM THE SOUTH TOWARD THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CHALLENGE TODAY INTO TONIGHT WILL BE THE EXTENT OF THE WARM AIR
AND SNOWFALL AMOUNTS.
THE FIRST BATCH OF SNOW ASSOCIATED W/WAA THIS MORNING WAS NEAR THE
MAINE-NEW BRUNSWICK BORDER PER RADAR LOOP. IR SATL IMAGERY SHOWED
BEST ENHANCEMENT LINING UP WELL W/HIGHER RADAR RETURNS IN THIS
REGION. ADJUSTMENTS WERE MADE TO THE SNOW IN AREAL COVERAGE
SHOWING 60-80% OVER THE EASTERN AREAS THIS MORNING. THIS MATCHES UP
WELL W/THE LATEST NAM12 AND RAP MODELS. AROUND AN INCH OF SNOW
CAN BE EXPECTED W/THIS FIRST BURST. WEAK LOW PRES MOVING ACROSS
THE EASTERN GREAT LAKES IS FCST TO MOVE ACROSS SOUTHERN NEW
ENGLAND THIS AFTERNOON AND THEN INTO THE GULF OF MAINE. THE
CONCERN IS WHERE TO DRAW THE RAIN/SNOW LINE AS WAA MAKES ITS WAY
TO THE BLYR. TEMPERATURES ARE FCST TO REACH INTO THE UPPER 20S TO
AROUND 30 ACROSS THE NORTHERN 1/2 OF THE CWA WHILE LOW TO MID 30S
ARE EXPECTED FOR CENTRAL AND DOWNEAST AREAS. AN INVERTED TROF
EXTENDING FROM THE LOW COMBINED W/SOME FRONTOGENETICAL FORCING AT
1000-700MB WILL LEAD TO A REFORMATION OF PRECIP AND AN ENHANCEMENT
OF THE PRECIP. USING THE BUFKIT PROFILES AND SOUNDINGS, THINKING
HERE IS THAT SNOW WILL REDEVELOP ACROSS PORTION OF NORTHEAST MAINE
W/THE HEAVIEST AXIS ACROSS THE HOULTON AND DANFORTH REGION W/LESS
SNOW NORTH AND WEST. S OF OF THE HOULTON-DANFORTH LINE,
TEMPERATURES WILL WARM INTO THE MID 30S TO ALLOW FOR SNOW TO MIX
WITH AND CHANGEOVER TO RAIN. THIS IN TURN WILL CUT DOWN ON
SNOWFALL LATER THIS AFTERNOON INTO TONIGHT. DECISION WAS TO GO
AHEAD AND ADD NORTHERN PENOBSCOT AND SE AROOSTOOK COUNTY IN THE
WINTER WEATHER ADVISORY THROUGH MONDAY MORNING DUE TO ENHANCED
FRONTOGENTICAL FORCING LEADING TO HEAVY SNOW BURSTS. LATEST SNOW
TOTAL MAP SHOWS A GENERAL 4-8 INCHES IN THE ADVISORY AREA W/1-4
INCHES N AND W. THE COAST AND EXTREME EASTERN WASHINGTON COUNTY
FROM MEDDYBEMPS TO EASTPORT WILL SEE 0.30 TO 0.70 INCHES OF
RAINFALL AFTER SOME INITIAL SNOWFALL.
SNOW WILL CONTINUE INTO TONIGHT ACROSS THE NORTHEASTERN SECTION OF
MAINE INCLUDING CARIBOU-PRESQUE ISLE DOWN THROUGH DANFORTH. WEST
OF THIS AREA, LITTLE OR NO SNOW AND RAIN/SNOW S OF THIS AREA
W/RAIN FOR THE COAST AS THE WARM AIR IS FCST TO STAY IN. TEMPERATURES
WILL DROP BACK INTO THE UPPER TEENS AND LOWER 20S NORTH AND WEST
AND MID TO UPPER 20S FOR CENTRAL AREAS. LOW 30S FOR THE DOWNEAST
REGION INCLUDING THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
SNOW WILL CONTINUE TO WIND DOWN EARLY MONDAY AS THE INVERTED TROF
EXTENDING FROM THE CANADIAN MARITIMES THROUGH DOWNEAST MAINE MOVES
OFF TO THE NORTHEAST. THERE MAY STILL BE SOME LINGERING LIGHT SNOW
OR SNOW SHOWERS PARTICULARLY ACROSS EASTERN AREAS OTHERWISE EXPECT
MOSTLY CLOUDY SKIES ACROSS THE REGION. MONDAY NIGHT WILL BE MOSTLY
CLOUDY BUT DRY AS WEAK HIGH PRESSURE RIDGES DOWN FROM THE NORTH.
ATTENTION THEN TURNS TO ANOTHER LOW PRESSURE SYSTEM THAT WILL BE
MOVING NORTHEAST ACROSS THE WESTERN ATLANTIC. THIS SYSTEM MAY BRINGS
SOME PRECIPITATION TO THE REGION LATER TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS SEEM TO BE COMING INTO BETTER AGREEMENT FOR THE NEXT SYSTEM
TUESDAY NIGHT AND WEDNESDAY. STILL SOME MODEL DIFFERENCES BUT THE
CONSENSUS SOLUTION IS FOR THE LOW TO TRACK FAR ENOUGH EAST THAT ANY
IMPACTS IN OUR REGION WOULD BE ACROSS DOWNEAST/EASTERN MAINE.
A WEAK BOUNDARY WILL CROSS THE REGION BY LATE WEEK WITH SOME
SNOW/RAIN SHOWERS POSSIBLE. AGAIN...WILL STICK CLOSE TO THE
SUPERBLEND.
HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION BY SATURDAY.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MVFR W/PERIODS OF VFR THIS MORNING DROPPING TO MVFR AND
EVEN IFR LATER THIS MORNING ON INTO TONIGHT. SNOW ACROSS THE NORTHERN
TERMINALS W/SNOW TO RAIN FOR KBGR TO KBHB.
SHORT TERM: MVFR CONDS ARE POSSIBLE EARLY MONDAY THEN VFR CONDS
EXPECTED MONDAY NIGHT INTO TUESDAY. MVFR CONDS ARE POSSIBLE IN
SOME LIGHT PRECIP LATE TUESDAY AND INTO EARLY WEDNESDAY. VFR ON
THURSDAY.
&&
.MARINE...
NEAR TERM: DECIDED TO GO W/A SCA THROUGH LATE MORNING. WINDS
GUSTING TO 25 KTS AS LLVL JET OF 30 KT MOVES ACROSS THE WATERS.
THE GFS AND NAM AS WELL AS THE LATEST RAP MODEL PICK UP ON THIS
FEATURE. WINDS ARE FCST TO DROP OFF THIS AFTERNOON AS THE LLVL JET
SHIFTS TO THE E. SEAS ARE AT 5FT AND COULD TIP 6 FT ESPECIALLY AT
44027(JONESPORT) THIS MORNING. SEAS WILL GRADUALLY SUBSIDE TONIGHT
BELOW 4 FT.
SHORT TERM: WINDS/SEAS WILL BE BELOW SCA LEVELS MON AND MON NIGHT.
WIND/SEAS MAY INCREASE TO SCA LEVELS TUE/TUE NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MEZ005-006-
011-016-017-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1247 AM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO CROSS THE STATE ON SUNDAY. ANOTHER
LOW MAY AFFECT THE REGION FROM THE SOUTH TOWARD THE MIDDLE PART OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE...RAMPED UP SNOWFALL CHANCES TO 90% OR MORE ACROSS THE NORTHERN
1/2 OF THE CWA AS THE LATEST RADAR LOOPS SHOWED A DECENT SWATH OF
SNOW MOVING ACROSS THE REGION. DECIDED OF 40-60% FOR SNOW FROM
CENTRAL AND DOWNEAST AREAS. LIGHT ACCUMULATIONS ARE EXPECTED
THROUGH THE EARLY MORNING. THE LATEST HRRR AND RAP WERE DOING WELL
W/THE PLACEMENT OF THE SNOW. ADJUSTED THE HRLY TEMPERATURES TO
MATCH THE LATEST CONDITIONS. SOME COOLING STILL IS EXPECTED ACROSS
THE FAR NORTH AND WEST AS THIS FIRST BATCH OF SNOW PUSHES E.
WINTER WEATHER ADVISORIES REMAIN IN PLACE ATTM FOR INTERIOR
DOWNEAST MAINE W/SNOW TOTALS OF 3 TO 6 INCHES EXPECTED. SOME OF
THE LATEST NUMERICAL GUIDANCE IS SHOWING MORE SNOW IN EASTERN
MAINE THROUGH SUNDAY NIGHT. THIS WILL NEED TO RE-VISITED DURING
THE MORNING PACKAGE.
WEAK LOW PRESSURE WILL SLIDE EASTWARD ACROSS THE GREAT LAKES
INTO SUNDAY. AS SUCH, EXPECT LIGHT SNOW TO DEVELOP OVER THE
REGION FROM NORTHWEST TO SOUTHEAST TONIGHT AND CONTINUE THROUGH
THE DAY ON SUNDAY. MODEL GUIDANCE CONTINUES TO INDICATE THAT A
BAND OF MODERATE TO HEAVY SNOW WILL DEVELOP LATER SUNDAY INTO
SUNDAY NIGHT IN ASSOCIATION WITH AN INVERTED TROUGH THAT WILL SET
UP SOMEWHERE ALONG THE COAST. WHILE THE NAM HAS COME MORE INTO
LINE OVER THE PAST FEW RUNS, IT CONTINUES TO BE A NORTHERN OUTLIER
WITH THIS BAND OF SNOW, SO LEANED HEAVILY ON THE GEM, GFS, AND
ECMWF FOR THIS FORECAST PERIOD. THESE MODELS HAVE BEEN CONSISTENT
WITH THEIR PLACEMENT OF THE BAND OVER DOWNEAST MAINE, THOUGH THEY
HAVE WAFFLED A BIT WITH EXACTLY HOW HEAVY THE QPF WILL BE. HAVE
THEREFORE STUCK CLOSE TO THE PREVIOUS FORECAST AS UNCERTAINTY IS A
BIT HIGHER THAN ONE WOULD ANTICIPATE FOR A STORM EXPECTED IN THE
NEXT 24-36 HOURS. IN ADDITION TO THE PLACEMENT OF THE CONCENTRATED
BAND, ALSO COMPLICATING THE SNOWFALL TOTAL FORECAST IS THE FACT
THAT TEMPERATURES WILL BE WARM ENOUGH DURING THE AFTERNOON FOR THE
SNOW TO MIX WITH AND/OR CHANGE TO RAIN ACROSS SOUTHERN AND COASTAL
DOWNEAST AREAS, ESPECIALLY FROM BANGOR SOUTH. FOR NOW, SNOWFALL
TOTALS OF 3 TO 5 INCHES ARE EXPECTED FROM ALONG AND SOUTH OF A
HOULTON TO DOVER-FOXCROFT LINE, WITH LESSER AMOUNTS AS YOU NEAR
THE COAST. ISOLATED AMOUNTS OF 5+ INCHES ARE POSSIBLE, ESPECIALLY
OVER NORTHERN WASHINGTON COUNTY. GIVEN THESE AMOUNTS, HAVE ISSUED
A WINTER WEATHER ADVISORY FOR LATE TONIGHT THROUGH SUNDAY NIGHT
FOR PORTIONS OF WASHINGTON, HANCOCK, AND PENOBSCOT COUNTIES. NORTH
OF THIS AREA, 1 TO 3 INCHES OF SNOW WILL BE THE RULE, WITH 1 INCH
OR LESS OVER THE FAR NORTH AND WEST.
FOR SUNDAY NIGHT...THE MODEL GUIDANCE HAS REALLY SHOWED A TIGHTENING
OF THE PRECIPITATION GRADIENT ON THE BACKSIDE OF THE AFOREMENTIONED
SNOW BAND; IN FACT, MANY GIVE THE NORTHWESTERN THIRD OF OUR AREA A
TRACE OR LESS OF QPF LATE AFTER 7PM/00Z. HAVE THEREFORE PULLED BACK
TO CHANCE POPS IN THESE AREAS FOR LATER TOMORROW INTO TOMORROW
NIGHT, ALONG WITH LIGHTER SNOWFALL AMOUNTS. THE HEAVIER SNOW OVER
DOWNEAST WILL CONTINUE INTO THE FIRST PART OF THE EVENING, BUT WILL
GRADUALLY TAPER OFF TO LIGHT SNOW TOWARD MIDNIGHT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
FOR THE SHORT RANGE...THE SUITE OF MODELS SHOW CONSIDERABLE SPREAD
WITH REGARD TO THE EXACT SCENARIO OF S/WVS XPCTD TO AFFECT OUR FA.
BEST WE CAN TELL...A WEAK (SECOND) S/WV WILL CROSS THE FA FROM SW
TO NE BRINGING SN/SHWRS OR A PD OF LGT SN TO THE FA. HI TEMPS
RECOVER WELL INTO THE 30S ACROSS ERN PTNS OF THE FA...EVEN AS
FAR AS NE AROOSTOOK COUNTY BY MON AFTN AS 925-850 MB TEMPS APCH
OR EVEN EXCEED 0 DEG C...SO SN COULD MIX WITH OR EVN CHG TO RN
SHWRS FOR A BRIEF TM MON AFTN. SNFL AMOUNTS MON COULD REACH UP
TO AN ADDITIONAL INCH OR SO.
ANY LEFT OVR SHWRS SHOULD BE ALL SN BY MID EVE MON AS SFC AND
TEMPS ALF COOL A LITTLE...BUT WITH LITTLE...IF ANY QPF XPCTD
MON NGT...ANY CORRESPONDING SNFL SHOULD BE NEGLIGIBLE THIS PD.
CLD CVR AND ERLY COMPONENT SFC WINDS SHOULD KEEP OVRNGT LOWS MILD
DURG THIS TM.
EVEN MORE UNCERTAINTY EXISTS WITH THE NEXT SERIES OF OF S/WVS AS
SPLIT IN THE FLOW ALF DEVELOPS OVR THE NE U.S. ON TUE. ANY LEAD
PRECIP WITH THESE SYSTEMS THAT ARRIVES MSLY BY TUE AFTN LOOKS TO
BE ON THE LGT SIDE ATTM. MORE SO...SFC AND 925-850 MB TEMPS WILL
EVEN BE MILDER THAN MON...SUGGESTING EVEN A GREATER POTENTIAL TO
GO OVR TO A PD OF RN SHWRS OVR ALL XCPT PERHAPS HIER TRRN OF NW
ME... REDUCING THE POTENTIAL OF ACCUMULATING SNFL ACROSS THE
REGION AS A WHOLE THIS PD.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODEL DIVERGENCE IN THE LONG RANGE IS EVIDENT FROM THE START OF
THE EXTENDED PERIOD. THESE DIFFERENCES CAN BE SEEN IN THE
LOCATION/TIMING OF THE SURFACE LOW OFF THE COAST OF MAINE AND BY
THE STRENGTH OF THE UPPER LEVEL LOW. THESE DIFFERENCES APPEAR TO
BE ASSOCIATED WITH A TROUGH THAT WILL BE PROGRESSING EAST OUT OF
THE WESTERN PORTION OF THE US. THE 12Z GFS IS MORE PROGRESSIVE
WITH THE UPPER LEVEL LOW TO THE WEST THAN THE 00Z ECMWF. SINCE
THERE IS STILL SOME UNCERTAINTY WILL CONTINUE WITH THE SUPERBLEND.
THIS WILL BRING BEST CHANCES OF PRECIP ACROSS THE SOUTHEASTERN
PORTIONS OF THE STATE TUESDAY NIGHT INTO WEDNESDAY.
WEAK RIDGING WILL BUILD IN BEFORE THE SYSTEM TO THE WEST
APPROACHES ALLOWING FOR SOME BRIEF BREAK THURSDAY. THERE ARE
CERTAINLY STILL TIMING AND LOCATION DIFFERENCES IN THE GUIDANCE
THAT WILL NEED TO BE WORKED OUT FOR LATE NEXT WEEK. THIS PERIOD
WILL ALSO STICK WITH THE CONSENSUS/SUPERBLEND APPROACH. THIS WILL
BRING THE NEXT BEST CHANCE OF PRECIP FRIDAY INTO SATURDAY WITH
BEST CHANCES ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. HIGH
AND LOW TEMPERATURES WILL BE NEAR TO LITTLE ABOVE NORMAL FOR THE
PERIOD.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR GOING TO MVFR OVERNIGHT AND DETERIORATE TO
IFR W/PERIODS OF LIFR AS SNOW SPREADS ACROSS THE REGION THROUGH
EARLY MORNING. THE SNOW AND IFR/LIFR CONDITIONS ARE EXPECTED TO
CONTINUE RIGHT THROUGH 00Z MONDAY, THOUGH KBGR AND KBHB WILL
TRANSITION OVER TO RAIN FOR A FEW HOURS SUNDAY AFTERNOON. IFR
CONDITIONS WILL POSSIBLY LIFT AT THE NORTHERN TERMINALS AFTER 00Z
MONDAY, BUT KHUL/KBGR/KBHB WILL REMAIN IFR THROUGH THE END OF THE
PERIOD.
SHORT TO LONG TERM: WE XPCT MVFR AT BEST OVR ALL OF THE TAF SITES
WITH PDS OF IFR IN SN/RN OR STEADY LGT SN/RN FROM TUE THRU THU.
&&
.MARINE...
NEAR TERM: SEAS ARE RUNNING 2 TO 3 FT AS OF 9 PM ON THE COASTAL
WATERS WITH A SSW WIND OF AROUND 15 KNOTS WITH GUSTS TO 20 KNOTS.
NEAR SCA CONDITIONS ARE EXPECTED LATE TONIGHT AND SUNDAY AS LOW
PRESSURE APPROACHES FROM THE NORTHWEST. SOUTH WINDS WILL INCREASE
AHEAD OF THIS LOW, WITH SOME GUSTS APPROACHING 25 KT. MEANWHILE,
SEAS WILL BUILD TO AROUND 4 FT. THESE CONDITIONS WILL IMPROVE
SUNDAY NIGHT AS THE WEAKENS. GIVEN THE BORDERLINE NATURE OF THE
WINDS AND WAVES, HAVE OPTED TO NOT ISSUE ANY HEADLINES AT THIS
TIME, BUT THE SITUATION WILL HAVE TO BE WATCHED CLOSELY.
SHORT TERM: INITIALLY NO HDLNS SHOULD BE NEEDED...THEN WINDS AND
SEAS INCREASE BEGINNING LATE MON NGT AS LOW PRES ORGANIZES S AND
E OF THE WATERS...POTENTIALLY REACHING SCA THRESHOLDS TUE AFTN...
THEN CONTG INTO WED MORN BEFORE SUBSIDING LATER WED. WE USED A BLEND
OF MODELS AND MOS GUIDANCE FOR WINDS AND BLENDED WW3 WITH SWAN NAM/GFS
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MEZ011-016-
017-032.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
432 AM EST SUN DEC 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM EST SUN DEC 1 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR GRT LKS TO THE SW OF UPR TROF CENTERED OVER NRN QUEBEC. IN
THE WAKE OF DEPARTING SHRTWV MOVING THRU SW QUEBEC...A SHRTWV RDG IS
SLIDING SEWD THRU NW ONTARIO...SUPPORTING A SFC HI PRES OVER FAR NW
ONTARIO. CLOSER TO UPR MI...A LO PRES TROF IS APRNT NEAR THE LK SUP
SHORE OF UPR MI AND EXTENDING WNW IN THE MN ARROWHEAD. THIS TROF HAS
BEEN THE FOCUS FOR SOME BANDS OF HIER REFLECTIVITY SHOWN ON THE MQT
88D REFLECTIVITY WITH UPSLOPE N WINDS NEAR LK SUP. SINCE H85 TEMPS
ARE ONLY -7 TO -8C AND THE ACCOMPANYING MSTR IS RELATIVELY SHALLOW
AS DIAGNOSED FM THE MQT 88D VWP AS WELL AS THE 00Z INL RAOB...WHICH
SHOWS INVRN BASE NEAR H85 UNDER VERY DRY MID LVLS AHEAD OF APRCHG
SHRTWV RDG...ASSOCIATED PCPN HAS BEEN A MIX OF -SHSN AND SOME -FZDZ.
THE 00Z YPL RAOB SHOWS SHALLOW MSTR AS WELL BLO AN INVRN NEAR
H925...SO PLENTY OF LO CLDS EXTEND WELL N INTO ONTARIO. THE AIR IS
MUCH COLDER THERE WITH SFC TEMPS IN THE TEENS...SO SPOTTY LGT PCPN
IS IN THE FORM OF SN.
MAIN FCST CONCERN IN THE SHORT TERM IS THE POTENTIAL FOR SOME LGT
-SN AND -FZDZ.
TODAY...WITH APRCH OF SHRTWV RDG NOW IN NW ONTARIO...LARGER SCALE
QVECTOR DVGC/MID LVL DRYING IS FCST TO SLOWLY WEAKEN...BUT NOT
ELIMINATE ALTOGETHER...THE SFC TROF NOW OVER LK SUP AND INHIBIT ANY
LARGER SCALE PCPN. SFC HI PRES NOW OVER FAR NW ONTARIO IS PROGGED TO
DRIFT ONLY SLOWLY SE ACRS NRN ONTARIO...WITH THE CWA DOMINATED BY
WEAKENING AND SLOWLY VEERING LLVL NE FLOW. WL CONT TO CARRY SOME CHC
POPS NEAR LK SUP IN AREA THAT WL EXPERIENCE AN UPSLOPE WIND
COMPONENT NEAR LINGERING LO PRES TROF OVER THE NCENTRAL. WHETHER
THIS PCPN IS ALL -SN OR REMAINS MIXED WITH SOME -FZDZ IS THE PRIMARY
CONCERN. MODELS REMAIN INCONSISTNET ON FCST H85 TEMPS AND MSTR
DEPTH. FCST H85 TEMPS ARE FCST TO FALL TO ARND -9C BY THE 00Z
NAM/LOCAL WRF-ARW TO -11C BY THE GFS. GIVEN THE WEAKENING WINDS THAT
WL LIMIT LLVL CAD AND EXPECTED NEGATIVE DYNAMICS AS WELL AS UPSTREAM
RAOBS...PREFER THE SOMEWHAT WARMER H85 TEMPS AND SHALLOWER MSTR
PROFILE/LOWER INVRN BASE SHOWN BY THE 00Z LOCAL WRF-ARW MODEL. THIS
MODEL SHOWS THE UPSLOPE UVV AND INVRN BASE REMAINING NR 5K FT AGL
AND BLO THE DGZ... SO WL RETAIN A MIX OF -SN/-FZDZ THRU THE DAY.
MARGINAL H85 TEMPS RELATIVE TO LK WATER TEMP ARND 4C WL LIMIT ANY SN
ACCUM. WITH PLENTY OF LO CLDS...TEMPS SHOULD REBOUND ONLY SLIGHTLY
THRU THE DAY.
TNGT...VERY LGT LLVL WINDS ARE PROGGED TO SLOWLY VEER TO THE E AND
SE AS THE CENTER OF SFC HI PRES SHIFTS INTO QUEBEC. SUSPECT
LINGERING LK EFFECT PCPN WL DRIFT INTO THE KEWEENAW AS THE FLOW
GRDLY SHIFTS TO THE ESE. IN THE ABSENCE OF ANY DYNAMIC SUPPORT...
EXPECT THE INVRN BASE TO REMAIN NEAR 5K FT. AS POINTED OUT BY THE
DAYSHIFT...LK VORTICES OFTEN DVLP WITH THE FCST LGT LLVL WINDS. BUT
MARGINAL H85 TEMPS ARND -9C WL LIMIT THE INTENSITY OF ANY SHSN THAT
WOULD ACCOMPANY THESE FEATURES...AND THE LGT WINDS WL INHIBIT
BANDING. SO ANY SN ACCUMS SHOULD REMAIN LGT. SINCE THE H85 TEMPS WL
REMAIN MARGINAL FOR LES AND UPSLOPE OMEGA WL REMAIN BLO THE
DGZ...INCLUDED A MENTION OF FZDZ. LINGERING LO CLDS WL LIMIT THE
DIURNAL TEMP FALL. BEST CHC FOR SOMEWHAT LOWER TEMPS WL BE OVER THE
E WITH A RELATIVELY UNMODIFIED/DOWNSLOPE E FLOW OFF ONTARIO THAT
MIGHT ALLOW FOR SOME BREAKS IN THE SC.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 430 AM EST SUN DEC 1 2013
MONDAY THROUGH TUESDAY MORNING...UPPER LEVEL 500MB TROUGHING IS
EXPECTED TO REMAIN IN PLACE ACROSS THE CWA THROUGH THIS TIME PERIOD
AS A WEAK INVERTED RIDGE WEDGES IN ACROSS THE AREA AT THE SURFACE. A
SLIGHTLY DRYER AIRMASS WILL ALSO LINGER THROUGH TUESDAY MORNING
WHICH CAN BE SEEN BY ANALYZING 1000-500MB RH. THE NEXT SURFACE LOW
CAN BE SEEN PUSHING ACROSS THE NORTHERN ROCKIES MONDAY NIGHT AND
EJECTING INTO THE NORTHERN OR CENTRAL PLAINS TUESDAY MORNING AS A
MUCH DEEPER UPPER LEVEL 500MB TROUGH BUILDS IN OVER THE WESTERN U.S.
THERE ARE STILL SOME MODEL DIFFERENCE HOWEVER WITH THE 00Z GFS/NAM
BEING A BIT FASTER AND STRONGER WITH THIS LOW. THE 00Z GFS/NAM
PLACE THE SURFACE LOW ALONG THE NORTH AND SOUTH DAKOTA BORDER BY 12Z
ON TUESDAY. THE 00Z EC/GEM ARE THE SLOWER OF THE SOLUTIONS KEEPING
THE LOW A BIT FARTHER SOUTH AND REMAINING OVER THE CENTRAL PLAINS
JUST A BIT EAST OF THE ROCKIES. EITHER WAY...BOTH SOLUTIONS KEEP THE
PRECIPITATION TO THE WEST OF THE AREA THROUGH THIS TIME PERIOD.
LIGHT EASTERLY WINDS THROUGH MONDAY NIGHT WILL SLOWLY BECOME
SOUTHEASTERLY BY TUESDAY. THIS ALONG WITH H850 TEMPS AROUND -8 TO
-10 C WILL HELP TO KEEP CONDITIONS CLOUDY WITH VERY LIGHT
PRECIPITATION POSSIBLE...MAINLY OVER THE KEWEENAW PENINSULA.
TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...THIS TIME PERIOD REMAINS
UNCERTAIN WHICH HAS BEEN THE CASE OVER THE PAST SEVERAL DAYS...WITH
POOR MODEL AGREEMENT EVEN AS THIS TIME PERIOD IS RAPIDLY
APPROACHING...HOWEVER...THE 00Z EC TENDS TO BE TRENDING A BIT CLOSER
TO THE NAM AND GFS SOLUTIONS. THE GFS/NAM SOLUTIONS BRING INCREASED
MOISTURE AND PRECIPITATION INTO THE CWA BY 18Z TUESDAY...WHILE THE
EC/CANADIAN KEEP THE SYSTEM CENTERED OVER NORTHEASTERN KS DURING
THAT TIME FRAME. THE 00Z GFS PLACES THE SURFACE LOW AND VERTICALLY
STACKED CLOSED UPPER LEVEL 500MB LOW OVER WESTERN WI AT 00Z WED
WHILE THE 00Z EC HAS THE MORE ELONGATED SURFACE LOW OVER CENTRAL
IOWA INTO CENTRAL PLAINS. BY 18Z WED THE 00Z RUN OF THE GFS PUSHES
THE LOW TO THE NORTHEAST OF LAKE SUPERIOR WHILE THE EC IS JUST
PLACING THE SURFACE LOW AND UPPER LEVEL ENERGY INTO THE WESTERN
PORTION OF WI. DEFINITELY EASY TO SEE THAT THERE ARE STILL
SIGNIFICANT DIFFERENCES BETWEEN THESE MODELS...HOWEVER...A BETTER
SIGNAL EXISTS SINCE THE EC IS TRENDING A BIT CLOSES TO THE FASTER
SOLUTIONS...THE BEST IDEA FOR THE TIME BEING WILL BE MORE OF A
MIDDLE OF THE ROAD APPROACH...WITH A SLIGHT LEAN TOWARD THE FASTER
SOLUTIONS. THIS WOULD FAVOR A LATE TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT TIME FRAME FOR THE MORE CONCENTRATED AREA OF PRECIPITATION.
SOUNDINGS FOR THIS TIME PERIOD INDICATE WARMER AIR LIFTING NORTHWARD
ON THE EAST SIDE OF THE LOW HELPING TO TRANSITION THE PRECIPITATION
OVER TO A RAIN SNOW MIXTURE FOR AT LEAST THE EASTERN HALF OF THE
UPPER PENINSULA AS A FAIRLY DEEP WARM LAYER BUILDS IN THROUGH MUCH
OF THE BOUNDARY LAYER. THE FAR WESTERN PORTION OF THE U.P. MAY END
UP SEEING MAINLY SNOW AS SHOWN BY ANALYZING BOTH THE EC AND GFS
PROFILES. IN ANY CASE THIS SYSTEM WILL BE CLOSELY WATCHED OVER THE
NEXT SEVERAL MODEL RUNS TO SEE IF BETTER UPPER AIR SAMPLING CAN
ENTERTAIN GREATER MODEL AGREEMENT.
THURSDAY THROUGH SATURDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME. EACH OF THE
MODELS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY 12Z
THURSDAY. AS THIS HAPPENS WINDS WILL SHIFT TO THE WEST ALLOWING LAKE
EFFECT SNOW TO DEVELOP IN AREAS FAVORED BY THAT PARTICULAR WIND
DIRECTION. THURSDAY THROUGH THURSDAY NIGHT THE LAKE EFFECT SNOW WILL
PROBABLY JUST BE STARTING ACROSS THE AREA...BUT SHOULD REMAIN LIGHT.
TRIED TO TREND THE LES CHANCES UPWARD FRIDAY THROUGH SATURDAY AS AN
UPPER LEVEL TROUGH/SHORTWAVE AND INCREASED MOISTURE SHIFTS INTO THE
AREA...ALLOWING FOR ENHANCED LIFT FOR LES TO DEVELOP. ITS STILL A
BIT TOO EARLY TO TELL FOR SURE ABOUT THE OVERALL SNOWFALL
TOTALS...BUT IT DOES LOOK LIKE FRIDAY INTO SATURDAY WILL BE SNOW FOR
WESTERLY WIND FAVORED AREAS OF THE UPPER PENINSULA. AS EARLIER SHIFT
STATED THE SNOW TO LIQUID RATIOS WILL LIKELY BE SLIGHTLY LOWER THAN
USUAL FOR LES AS THE DGZ IS FAIRLY SHALLOW AND FAIRLY LOW IN THE
ATMOSPHERE...WHICH TENDS TO INHIBIT THE MORE FAVORABLE GROWTH RATES
FOR SNOW. STAY TUNED THOUGH AS THIS LES EVENT GETS CLOSER TOWARD THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1208 AM EST SUN DEC 1 2013
COOLER AIR MOVING ACROSS LAKE SUPERIOR BEHIND A LOW PRESSURE SYSTEM
HAS RESULTED IN A MIX OF LIGHT LAKE EFFECT SNOW AND FREEZING DRIZZLE
ACROSS NW AND NCNTRL PORTIONS OF THE FCST AREA THIS EVENING. EXPECTATION
IS THAT THE SNOW/FZDZ WILL CAUSE MVFR TO IFR CONDITIONS AT TAF
SITES OVERNIGHT. A HIGH PRESSURE RIDGE MOVING OVER LAKE SUPERIOR OVERNIGHT
WILL SLOWLY VEER THE WINDS TO THE NORTH-NORTHEAST AND LEAD TO LESS
FAVORABLE WIND DIRECTIONS FOR KCMX/KIWD SO WILL CONTINUE TO SHOW A
DIMINISHING TREND IN SNOW SHOWERS AND RAISE CEILINGS SOMEWHAT BUT
STILL IN MVFR RANGE. CONFIDENCE IN SNOW SHOWER LOCATION/STRENGTH
DIMINISHES LATE TONIGHT INTO SUNDAY...DUE TO WINDS BECOMING LIGHT AND
VARIABLE THROUGH THE DAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 AM EST SUN DEC 1 2013
EXPECT NE WINDS UP TO 20 KTS EARLY THIS MORNING TO DIMINISH UNDER
15 KTS AND SLOWLY VEER INTO MON AS A WEAK PRES GRADIENT EXTENDING S
FROM HI PRES MOVING THRU ONTARIO DOMINATES THE UPPER LAKES. STRONGER
E TO SE WINDS UP TO 25 TO PERHAPS 30 KTS WILL THEN DEVELOP INTO MID
WEEK AS THE GRADIENT SHARPENS OVER LAKE SUP BETWEEN THE HI PRES
SHIFTING INTO QUEBEC AND LO PRES MOVING NE FROM THE PLAINS. THERE
WILL BE A SHARP WIND SHIFT TO THE WNW BY THU FOLLOWING THE PASSAGE
OF THE LO TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE A W GALE ON THU INTO FRI.
&&
.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 DETROIT/PONTIAC MI
1145 PM EST SAT NOV 30 2013
.AVIATION...
//DISCUSSION...
PLENTY OF MID LAYER CLOUD FOR THE OVERNIGHT HOURS. THERE IS AN AREA
OF MVFR CIGS AROUND THE FRONT AND THIS WILL MOVE INTO THE TAF SITES
ON SUNDAY MORNING FOR MBS AND FNT...BUT NOT UNTIL THE AFTERNOON FOR
THE SOUTHERN TAF SITES. ANY PRECIPITATION WITH THE FRONT WILL BE
LIMITED. WILL BRING A FEW HOURS OF LIGHT PRECIPITATION FOR THE
NORTHERN SITES...WITH ONLY MBS HAVING THE POTENTIAL TO HAVE MVFR
VSBY. WITH A LOOK AT THE CURRENT SOUNDING AT DTX AND MODEL
SOUNDINGS... WILL ADD SOME MIXED RAIN AND SNOW.
FOR DTW...DRY AIRMASS PRE COLD FRONT TONIGHT WILL KEEP CLOUDS ABOVE
5000 FT. MVFR CLOUD WILL THEN SETTLE OVER THE TAF SITE DURING SUNDAY
LATE MORNING AND EARLY AFTERNOON IN RESPONSE TO LOW LEVEL COLD AIR
ADVECTION.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILING HEIGHTS BELOW 5000 FT PRIOR TO 15Z
SUNDAY. HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET SUNDAY AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 916 PM EST SAT NOV 30 2013
UPDATE...
CURRENT CONDITIONS ARE CERTAINLY SUPPORTIVE OF FOLLOWING THE
PREVIOUS FORECASTS THOUGHTS ON LOWER CHANCES OF PRECIPITATION THAN
WHAT THE 12Z AND 18Z MODELS ARE SUGGESTING. NEARLY ALL OF THE
RADAR RETURNS OVER LOWER MICHIGAN ARE VIRGA. LATEST RUC RUNS ARE
MORE SUPPORTIVE OF A DRIER OVERNIGHT AND ARE REALLY IN LINE WITH
THE CURRENT FORECAST POPS...CLOUDS AND QPF. 00Z SOUNDINGS AND THE
LATEST RUC SOUNDINGS SUGGEST THAT IT WILL TAKE SOME TIME TO
SATURATE THE LAYER BETWEEN 3K AND 6K FEET. WHILE THERE IS SOME
MOISTURE ALONG THE FRONT BELOW 3K FEET...IT IS REALLY ABOVE THIS
THAT DRY AIR REMAINS IN PLACE TO LIMIT PRECIP. THE OTHER ITEM THAT
SHOWS WELL IN THE SOUNDINGS IS THAT THE FREEZING LEVEL WILL LIKELY
BE 1000 TO 2000 FEET ABOVE THE SURFACE WHEN WE FIRST SATURATE. ANY
PRECIP THAT HAS FALLEN ACROSS NRN LOWER THIS EVENING HAS BEEN
RAIN. THEREFORE WILL BRING IN A MIX OF RAIN...AT LEAST AT THE
START...FOR ANY PLACE THE DOES GET SOME PRECIP OVERNIGHT.
WILL RAISE TEMPS JUST A BIT OVERNIGHT DUE TO THE COMBINATION OF
THE CLOUDS AND SOUTHERLY WIND AHEAD OF THE COLD FRONT. TEMPS WILL
EVENTUALLY REACH THEIR FORECAST LOWS WITH THE FRONTAL PASSAGE OR
WITH THE EVAPORATE COOLING. THE EXCEPTION WILL BE IN THE FAR
SOUTH OF THE FORECAST AREA WHERE MOSTLY CLEAR SKIES ARE ALLOWING
TEMPS TO FALL.
PREV DISCUSSION...ISSUED 319 PM EST SAT NOV 30 2013
SHORT TERM...TONIGHT
A THERMAL WAVE DIGGING SOUTHEASTWARD ALONG THE TRAILING EDGE OF NE
NORTH AMERICAN UPPER LEVEL TROUGH WILL BE THE WEATHER AFFECTING THE
CENTRAL GREAT LAKES TONIGHT. THE CYCLONIC VORTICITY ENERGY
ASSOCIATED WITH THE SHORT WAVELENGTH THERMAL RIDGE IS FRAGMENTED
WITH THE INITIAL SHORTWAVE DAMPENING WHILE IT PUSHES EAST OF LAKE
SUPERIOR THIS AFTERNOON. A SECOND SHORTWAVE IS NOW SLIDING THROUGH
THE MINNESOTA ARROWHEAD AND INTO THE FAR WESTERN LAKE SUPERIOR BASIN
TAKING OVER WITH TIME. THIS SHORTWAVE WILL PROVIDE A NECESSARY
FORCING COMPONENT AFTER 9Z OVER THE FAR NORTHERN CWA WHICH SHOULD
FINALLY ALLOW PRECIPITATION TO FALL. OTHERWISE THE MIX OF DYNAMICS
SUPPORTIVE OF ASCENT IS LIMITED. ANALYSIS OF 285K SYSTEM RELATIVE
ISENTROPIC ASCENT IS VERY UNINSPIRING DESPITE SOME LINKAGE OF RIGHT
ENTRANCE REGION DYNAMICS ALOFT WITH 850-700MB DEFORMATION. THE
DEFORMATION IS MODELED TO BE ASSOCIATED WITH THE CONVERGENCE FEATURE
OF THE FRONT. EXPECT THIS FORCING TO STRIPE FOR A VERY LIMITED TIME
FROM WEST TO EAST NORTHEAST...PRIMARILY ACROSS THE FAR NORTHERN
COUNTIES. WET BULB AND OFFERED BUFKIT SOUNDINGS SUPPORT AN ALL SNOW
EVENT...TRENDED TO ALL SNOWFLAKES. A DUSTING WILL BE POSSIBLE NORTH
AFTER 8Z...PERHAPS A HALF TO 1 INCH IN THE NORTHERN THUMB.
LONG TERM...SUNDAY THROUGH NEXT SATURDAY
MID LEVEL ENERGY IS FORECAST TO RAPIDLY SHEER TO THE EAST OF THE
AREA LATE SUNDAY MORNING. THE 12Z MODEL SUITE ALL SUGGEST THE
ASSOCIATED MID LEVEL ASCENT WILL RESIDE ALONG THE 1-69 CORRIDOR INTO
THE THUMB REGION BY 12Z BEFORE QUICKLY WANING BY NOON. BOTH NAM AND
GFS APPEAR TOO AGRESSIVE IN MOISTENING THE LOW LEVELS...SUGGESTING
THAT WET BULB COOLING MAY BE STRONG ENOUGH TO KEEP ANY LINGERING
MORNING PRECIP AS LIGHT SNOW. UPSTREAM OBSERVATIONS DO HOWEVER
SUPPORT MODEL SOLUTIONS WHICH BRING A POST FRONTAL LOW STRATUS DECK
INTO THE AREA FOLLOWING THE PASSAGE OF A WEAK SURFACE COLD FRONT.
THESE LOW CLOUDS ARE EXPECTED TO ENVELOPE THE TRI CITIES AND THUMB
BY DAYBREAK...THEN OVERSPREAD METRO DETROIT EARLY SUN AFTERNOON.
OVERALL WEAK POST FRONTAL COLD AIR ADVECTION WILL SUPPORT SUN MAX
TEMPS IN THE MID/UPPER 30S ACROSS THE NORTH AND LOW 40S SOUTH OF THE
I-96/696 CORRIDOR.
THE DEPTH OF THE POST FRONTAL COLD AIR SUN AFTERNOON WILL BE GREATER
OVER LAKE HURON...WHICH WILL RESULT IN A DEEPENING CONVECTIVE DEPTH
OVER THE LAKE. MODEL SOLUTIONS SUGGEST A GOOD RESPONSE OFF THE
LAKE...ENOUGH TO SUPPORT A CHANCE OF SNOW SHOWERS OVER THE THUMB SUN
AFTERNOON INTO SUNDAY EVENING AS THE FLOW TURNS TOWARD THE NE. THE
EXPECTED DEGREE OF VARIABILITY IN THE LOW LEVEL WIND DIRECTION DOES
NOT SUPPORT A PROLONGED CONVERGENT BAND...SO FORECAST ACCUMS WILL BE
KEPT MINIMAL. MID LEVEL SUBSIDENCE WILL LOWER INVERSION HEIGHTS SUN
NIGHT AND WILL MAINTAIN THE LOW STRATUS OVER THE REGION. CONTINUED
LOW LEVEL MOISTURE FLUX UNDER THE NE FLOW MAY HOWEVER SUPPORT SOME
DRIZZLE SUN NIGHT INTO MON MORNING OVER A GOOD PORTION OF SE MI.
CONFIDENCE IS NOT QUITE HIGH ENOUGH TO ADD DRIZZLE TO THE
ZONE/GRIDS AT THIS POINT...BUT IS SOMETHING LATER SHIFTS WILL
HAVE TO MONITOR. AMPLE LOW CLOUDS AND WEAK LOW LEVEL THERMAL
ADVECTION IS LIKELY TO HOLD TEMPS IN THE 30S SUN NIGHT INTO MON
MORNING.
A LOW AMPLITUDE MID LEVEL TROUGH IS FORECAST TO TRAVERSE THE OHIO
VALLEY ON MONDAY. DESPITE THE OVERALL WEAK FORCING WITH THIS
FEATURE...MODEL SOLUTIONS DO SUGGEST A HEALTHY SURGE OF MID LEVEL
MOISTURE INTO SRN MI. THIS COUPLED WITH THE EXPECTED STRATUS AND
WEAK LARGE SCALE ASCENT MAY BE ABLE TO GENERATE A FEW LIGHT SNOW
AND/OR RAIN SHOWERS.
SOUTHEAST MICHIGAN CONTINUES TO BE ON A ROLLER COASTER AS FAR AS
TEMPERATURES ARE CONCERNED WITH TEMPS WARMING THROUGH THURSDAY
BEFORE COOLING OFF BY THE WEEKEND. UPPER LEVEL RIDGE WILL WORK INTO
THE AREA TUESDAY HELPING TO KEEP THINGS ON THE DRIER SIDE. PRECIP
CHANCES START TO INCREASE WEDNESDAY AS A LOW TRAVERSES OVER THE
NORTHERN GREAT LAKES. SOUTHERLY FLOW OUT AHEAD OF THIS SYSTEM WILL
HELP TO BRING IN MOISTURE AND WARMER AIR. PRECIP TYPE WILL LIKELY
START OFF AS SNOW BEFORE QUICKLY TRANSITIONING TO ALL RAIN AS
WARMER TEMPS OVERSPREAD THE AREA. BETTER CHANCE FOR MEASURABLE
PRECIP WILL COME THURSDAY INTO FRIDAY AS ANOTHER LOW DEVELOPS AND
MOVES TOWARDS THE GREAT LAKES. CURRENTLY THIS LOW LOOKS TO TRACK
SOUTH OF MICHIGAN WHICH WOULD PUT THE CWA IN THE COLD SECTOR WITH
SNOW BEING THE MAIN PRECIP TYPE. COOLER TEMPS MAKE A RETURN NEXT
WEEKEND AS WESTERLY FLOW INCREASES OVER SOUTHEAST MICHIGAN.
MARINE...
THE SOUTHERLY WINDS WILL DIMINISH DURING THE COURSE OF THE EVENING
AS THE GRADIENT RELAXES. THIS WILL OCCUR AS A WEAK AREA OF LOW
PRESSURE EXPANDS ACROSS LAKE HURON TONIGHT. THIS LOW WILL ADVANCE
INTO ONTARIO ON SUNDAY WHICH WILL CAUSE THE WINDS TO TURN
NORTHEASTERLY OVER LAKE HURON. WIND SPEEDS WILL INCREASE DURING THE
AFTERNOON. GUSTS SHOULD REMAIN AT OR BELOW 25 KNOTS. THE GRADIENT
WILL THEN RELAX BY MONDAY. WEAK HIGH PRESSURE WILL RESULT IN LIGHT
WINDS INTO WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....JVC
UPDATE.......JVC
SHORT TERM...CB
LONG TERM....SC/SS
MARINE.......SC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
339 AM CST Sun Dec 1 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Sun Dec 1 2013
Think the challenge for today will be forecasting cloud cover. A
stratus deck between 4000-5000ft is moving across he eastern Ozarks
and parts of Southern Illinois this morning. Think this area of
stratus will continue advecting eastward faster than the western
edge will erode as has been the case for the past few hours.
Therefore there should be substantial cloud cover over southeast
Missouri and parts of southern Illinois this morning. The 00Z NAM
eventually cleared it out and this matches well with satellite
trends at this time; however the RAP backbuilds the cloud cover, as
does the 06Z NAM and this suggests that areas generally southeast of
a line from Vichy, MO to Salem, IL may not see much sun today. Am
sticking closer to the less cloudy solution at this time, but this
may ultimately prove to be too optimistic.
Temperatures may be challenging as well. Can`t seem to forecast
warm enough the past couple of days. Missed highs both Friday and
Saturday by to to three degrees. Lingering cloud cover over the
eastern Ozarks and southwest Illinois may make this especially
challenging. For highs today, used a blend of 925 mix-down
temperatures and MOS. Tweaked southern zones down a couple of
degrees from that to account for cloud cover, and the rest of the
area up a degree or two to try to compensate for my apparent cool
bias.
Britt
.LONG TERM: (Tonight through Saturday)
Issued at 335 AM CST Sun Dec 1 2013
(Tonight - Tuesday)
Have not made too many changes to going forecast during this
period. Low level moisture progs suggest that stratus will
redevelop this evening, particularly over the southern and
eastern part of the CWA. Have kept chance of light drizzle in
these areas where this moisture will be the deepest and there will
be some very light ascent. As we go into Monday, GFS/NAM/ECMWF all
show a weak shortwave trough racing into the area from the west,
though it is not as deep as was forecast 24 hours ago. Have left
chance of sprinkles in for tomorrow morning as the trough axis
will move through the area by midday.
Temperatures will begin to warm up ahead ahead of the next storm
system. Expect temperatures to climb into the 50s on Monday with
some spots reaching 60 on Tuesday.
(Wednesday - Saturday)
Main concern continues to be the potential for a wintry precipitation
and the big cool down mid to late week. There still ia a great
deal of uncertainty regarding timing, precipitation types and
amounts. While the GFS is still the fastest with the passage of
the cold front, the 00Z ECMWF now brings the cold front through
the area during the day on Wednesday instead of Wednesday Night.
The cold front will have moved to the south of the area
Wednesday. Best forcing for precipitation will hinge on mid-level
frontogenesis and shortwave troughs moving through fast west-
southwesterly flow aloft. Have likely pops on Thursday and
Thursday Night over southeastern half of the CWA with the chance
continuing into Friday. Will continue to have a simple mix of rain
and snow because of the uncertainty for now, but thermal profiles
from forecast soundings certainly suggest the potential for sleet
or freezing rain over the southern half of the CWA. 850mb
temperatures by next Friday and Saturday will be in the -10 to
-12C range supporting highs only in the 20s with lows in the
single digits and teens.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1133 PM CST Sat Nov 30 2013
Weak surface frontal boundary extending from central Michigan
through far northwest Illinois and then becoming stationary over
northern Kansas. Front is expected to move southeast and move
through UIN-COU areas between 0900 and 1100 UTC and through STL
area after 1400 UTC. Scattered to broken area of clouds will move
through the southern half of Missouri from 0600 - 1100 UTC.
Scattered area of clouds will be east of COU and south of UIN
areas. Surface winds will shift from WSW to NW direction after
passage of front. Wind speeds will range from 4 to 7 kts.
Specifics for KSTL: Scattered to broken layer of clouds at 040
will move through STL area between 0600 and 0900 UTC. Surface
winds will be light southwest then shift to West-northwest
direction around 5 kts after 1400 UTC. Clouds will remain
scattered 040 with higher broken deck aob 200. Surface winds will
shift to north-northwest by early afternoon with speeds o0f 4 to 6
kts.
Przybylinski
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
303 AM EST SUN DEC 1 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE REGION TODAY. LOW PRESSURE DEVELOPS
ALONG THE CAROLINA COAST TONIGHT AND GRADUALLY STRENGTHENS AS IT
MOVES AWAY FROM THE REGION MONDAY. HIGH PRESSURE THEN RETURNS FOR
TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 300 AM SUNDAY...
THE SURFACE RIDGE AXIS EXTENDED NORTHEAST TO SOUTHWEST ACROSS
CENTRAL NORTH CAROLINA...WITH A SLACK GRADIENT IN PLACE. IN A FAST
WESTERLY FLOW ALOFT...AS ONE MID-LEVEL SHORTWAVE EXITED CENTRAL
NORTH CAROLINA TO THE EAST...ANOTHER WAS MOVING IN FROM THE TENNESEE
VALLEY. THE 00Z RAOB ANALYSIS SHOWED GREATER 850MB AND 700MB
MOISTURE JUST TO OUR SOUTH...AND SOME OF THIS MOISTURE HAS ADVECTED
NORTH...TO ABOUT U.S. 64. THE NAM AND THE GFS ARE FAIRLY SIMILAR AND
BOTH HAVE TRENDED DRIER CERTAINLY FROM THE PREVIOUS 00Z RUN...SUCH
THAT THE MID LEVELS TEND TO BE FAIRLY DRY FOR MUCH OF THE DAY
TODAY...WITH THE GREATEST MID-LEVEL MOISTURE OVER THE SOUTHERN
COASTAL PLAIN RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. THE
BEST 850MB LIFT IS CERTAINLY IN THE SOUTHEAST PART OF CENTRAL NORTH
CAROLINA TODAY WHERE 850MB THETA-E ADVECTION IS GREATEST. FAINT
RADAR RETURNS AND GUIDANCE FROM THE HRRR WRF SUGGEST A SMALL CHANCE
OF SPRINKLES IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN THIS
MORNING...WITH A CHANCE OF RAIN MAINLY THIS AFTERNOON ALONG AND
SOUTH OF A LINE FROM ABOUT KRWI TO KRCZ...WITH THE BEST CHANCE
TOWARD KCTZ IN VICINITY OF GREATER MOISTURE AND LIFT.
PRECIPITATION...IF ANY...SHOULD BE LIGHT...WITH THE GREATER
PROBABILITY OF PLURAL HUNDREDTHS IN SAMPSON AND POSSIBLY INTO WAYNE
COUNTIES AS OF THIS WRITING.
1000-850MB THICKNESSES WOULD SUPPORT WARMER TEMPERATURES THAN
FORECAST BY ABOUT A CATEGORY...BUT A BLEND OF GUIDANCE WORKED WELL
FOR SATURDAY HIGHS...AND WILL FOLLOW THE SAME FOR TODAY. FEWER AND
THINNER CLOUDS NORTHWEST...MORE TOWARD THE SOUTHEAST BUT WITH HIGHER
THICKNESSES AND MORE MOIST...RESULT IN A FAIRLY UNIFORM TEMPERATURE
FORECAST IN THE LOWER TO POSSIBLY MID 50S. WINDS SHOULD BE
LIGHT...WITH THE RELATIVELY GREATER SPEEDS TOWARD THE TRIAD...WHILE
STILL UNDER 10KT...FROM THE SOUTHWEST...WEST OF THE SURFACE RIDGE
AXIS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SUNDAY...
AGAIN THE NAM AND GFS ARE FAIRLY SIMILAR IN THE EVOLUTION OF THE
SURFACE LOW ALONG THE COAST...WITH AN INVERTED TROUGH DEVELOPING
EARLY TONIGHT FOLLOWED BY WEAK CYCLOGENESIS OVERNIGHT...THEN LOW
PRESSURE GRADUALLY STRENGTHENING MONDAY AS IT MOVES AWAY FROM THE
COASTAL CAROLINAS. 850MB LIFT IS NOT VERY STRONG OVERNIGHT INTO
MONDAY AFTERNOON...WITH THE GFS IN PARTICULAR HAVING TRENDED FARTHER
SOUTH WITH THE PASSAGE OF ITS MODERATE MID-LEVEL SHORTWAVE
ACCOMPANYING THE MID-LEVEL TROUGH. JET SUPPORT ALSO LOOKS TO HAVE
SHIFTED FARTHER SOUTH COMPARED TO RECENT RUNS. K INDICES ARE HIGHEST
TOWARD THE COAST LATE TONIGHT AND MONDAY MORNING...BUT 850MB THETA-E
STILL REMAINS MODEST WEST THROUGH THE COASTAL PLAIN...AND WITH THE
WEAK LIFT AS LOW PRESSURE ORGANIZES JUST OFFSHORE...WILL CONTINUE AT
LEAST A CHANCE OF RAIN EARLY TONIGHT MAINLY EAST OF INTERSTATE 95
WHEN OVERALL MOISTURE APPEARS HIGHEST FOR THE NIGHTTIME HOURS...
THEN AGAIN MAINLY MONDAY MORNING ALONG AND EAST OF ABOUT U.S. 1
DURING A PERIOD OF A MODEST INCREASE IN MID-LEVEL MOISTURE IN
CONJUNCTION WITH GOOD LOWER-LEVEL MOISTURE. FOR NOW WILL KEEP
CHANCES BELOW LIKELY GIVEN THE DRIER MODEL TRENDS...NO MOS GUIDANCE
IN CENTRAL NORTH CAROLINA CLOSE TO LIKELY...AND NAM AND GFS MODEL
QPF BEING PRETTY LOW. PLAN TO KEEP THE TRIAD AND THE FAR WESTERN
PIEDMONT DRY THIS PERIOD.
850MB THETA-E TROUGHINESS STARTS TO PUSH EAST MONDAY AFTERNOON WITH
INCREASING SUBSIDENCE. BUFR SOUNDINGS ARE FAIRLY STABLE AND DRYING
CERTAINLY BY 00Z TUESDAY...AND PRECIPITABLE WATER VALUES ARE AT OR
BELOW A HALF-INCH MONDAY NIGHT. WILL NOTE CHANCES BELOW SLIGHT IN
CENTRAL NORTH CAROLINA BY 00Z TUESDAY. LOWS TONIGHT AND HIGHS MONDAY
ARE A LITTLE TRICKY GIVEN THE UNCERTAINTY SURROUNDING CLOUD COVER
AND THE POTENTIAL VARIABLE THICKNESS OF SUCH CLOUD COVER. OPTED TO
TRIM LOWS TONIGHT SLIGHTLY ESPECIALLY ALONG AND NORTH OF INTERSTATE
85 WHERE CLOUD COVER SHOULD BE LEAST AND THINNEST OVERNIGHT. GIVEN
THE DRIER MODEL TREND OPTED TO RAISE MAXES INTO THE 50S THROUGHOUT
CENTRAL NORTH CAROLINA MONDAY...STILL KEEPING THE WARMER READINGS
OVER THE WESTERN PIEDMONT FOR NOW. OVERNIGHT LOWS MONDAY NIGHT NEAR
THE COOLER MAV MOS GUIDANCE ANTICIPATING FEWER CLOUDS...LOWER TO MID
30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...
WEAK HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY IN THE WAKE
OF THE DEPARTING COASTAL CYCLONE AS A WESTERLY FLOW DEVELOPS ALOFT.
FAIR WEATHER IS EXPECTED IN CENTRAL NC WITH A FEW LAYERS OF CLOUDS.
HIGHS WILL RANGE IN THE LOWER 50S NORTHEAST TO NEAR 60 TOWARD THE SC
BORDER.
HEIGHTS BEGIN RISING ON WEDNESDAY AND THURSDAY AS A BROAD TROUGH
DEVELOPS IN THE ROCKIES AND THE NORTHERN PLAINS. AN INCREASINGLY
MOIST SOUTHERLY FLOW WILL PROMOTE AN INCREASE IN CLOUDINESS ON
WEDNESDAY AND THURSDAY WITH WARMING TEMPERATURES ESPECIALLY ON
THURSDAY. BOTH THE EC EFS AND THE GFS HIGHLIGHT A SHALLOW
DISTURBANCE THAT WILL MOVE NORTHEAST ACROSS THE AREA ON WEDNESDAY
THAT SHOWS UP AS A REGION OF ISENTROPIC UPGLIDE IN THE 290-295
LAYER. DON`T EXPECT ANY PRECIPITATION AT THIS TIME BUT HAVE
INCREASED CLOUD PERCENTAGES DURING THE PERIOD. GFS BUFR SOUNDINGS
ALSO SUGGEST THAT THERE COULD BE SOME GUSTY WINDS ON WEDNESDAY
AFTERNOON WITH GUSTS UP TO 20-25 MPH AS MIXING TAPS INTO THE
STRONGER FLOW ASSOCIATED WITH THE LOW LEVEL JET. A SLIGHTLY BETTER
CHANCE OF RAIN ARRIVES IN THE NORTHWESTERN PORTION OF THE FORECAST
AREA LATE THURSDAY AND ESPECIALLY THURSDAY NIGHT AS A COLD FRONT
APPROACHES THE REGION FROM THE WEST. TEMPERATURES SHOULD WARM INTO
THE MID 50S TO NEAR 60 ON ON WEDNESDAY AND THEN THE 60S TO NEAR 70
ON THURSDAY.
DIFFERENCES IN THE GFS AND EC EFS BECOME MORE APPARENT ON FRIDAY AND
ESPECIALLY SATURDAY WITH THE GFS BEING FASTER AND PUSHING THE FRONT
THROUGH THE AREA LATE FRI/EARLY SAT WITH THE EC PERHAPS 12 HOURS
SLOWER. WHILE THE BEST FORCING FOR ASCENT STAYS NORTH OF THE
AREA...THE PLUME OF DEEP LAYER MOISTURE AND FORCING ASSOCIATED WITH
THE FRONT SHOULD BE SUFFICIENT FOR CHC POPS. MILD TEMPERATURES ARE
EXPECTED ON FRIDAY AHEAD OF THE FRONT AND AHEAD OF THE MAIN AREA OF
RAIN. MAX TEMPS HAVE BEEN ADJUSTED UPWARD INTO THE UPPER 60S
NORTHWEST TO NEAR 75 IN THE SOUTHEAST. ALSO ADJUSTED MIN TEMPS ON
SATURDAY UPWARD TO ACCOUNT FOR THE CLOUDS AND MILD CONDITIONS AHEAD
OF THE FRONT. MAX TEMPS ON SATURDAY WILL BE LIMITED GIVEN THE CLOUDS
AND AREAS OF LIGHT RAIN BUT STILL EXPECT TEMPS TO REACH THE UPPER
50S NORTHWEST TO MID 60S SOUTHEAST. AT THIS POINT WE DON`T EXPECT
ANY THUNDERSTORMS LATE FRIDAY INTO SATURDAY THUNDERSTORMS GIVEN THE
MARGINAL MID LEVEL LAPSE RATES.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1255 AM SUNDAY...
MOSTLY VFR CONDITIONS WILL CONTINUE THROUGH THE 06Z VALID TAF
PERIOD. AREAS OF MVFR CONDITIONS WILL OCCUR TOWARD KFAY AND KRWI
THIS MORNING...WITH PATCHY MVFR CONDITIONS IN EITHER LOW CLOUDS OR
LIGHT FOG TOWARD KRDU. MAINLY DURING THE AFTERNOON AND EVENING
PATCHY LIGHT RAIN IS POSSIBLE SOUTH OF A LINE FROM ABOUT KFAY TO
KRWI. THIS IS WHERE ANY THICKER CLOUDS SHOULD RESIDE DURING THAT
TIME...THOUGH THEY ARE EXPECTED CURRENTLY TO HAVE A HIGHER
PROBABILITY OF BEING VFR. WITH HIGH PRESSURE OVERHEAD...WINDS SHOULD
BE SOMEWHAT VARIABLE. JUST ON THE WEST SIDE OF THE SURFACE RIDGE
AXIS...WINDS SHOULD BE MORE SOUTHWEST TOWARD THE TRIAD. WINDS SHOULD
TEND TO FAVOR NORTHERLY TOWARD KFAY. AT KRWI AND ESPECIALLY KRDU...
THE LIGHT SURFACE WIND DIRECTION IS MORE CHALLENGING...LEANING
WESTERLY DURING THE DAYLIGHT HOURS THOUGH IT COULD BE QUITE VARIABLE.
BEYOND THE 06Z VALID TAF PERIOD...THE GREATEST PROBABILITY OF SUB-
VFR CONDITIONS OVERNIGHT INTO MONDAY MORNING IN CLOUDS AND PATCHY
LIGHT RAIN WILL BE ALONG AND EAST OF INTERSTATE 95...LEANING MVFR AS
A CATEGORY...WITH A CHANCE OF SUB-VFR CONDITIONS IN LIGHT FOG TOWARD
THE TRIAD. KRDU WILL BE IN BETWEEN...AND IT IS POSSIBLE FOR A PERIOD
OF BOTH LIGHT FOG AND LOWER CLOUDS THERE BEFORE DRIER AIR AND
SUBSIDENCE MOVING IN FROM THE WEST CREATE WIDESPREAD VFR CONDITIONS
ACROSS CENTRAL NORTH CAROLINA BY LATE MONDAY AFTERNOON. MVFR
CONDITIONS IN FOG ARE POSSIBLE LATE MONDAY NIGHT AND EARLY
TUESDAY...THEN AS MOISTURE INCREASES...THERE IS A CHANCE OF SUB-VFR
CONDITIONS IN LOW CLOUDS TUESDAY NIGHT INTO WEDNESDAY...WITH GREATER
CHANCES OF THOSE CONDITIONS CURRENTLY TOWARD THE TRIAD THOUGH
POSSIBLE THROUGHOUT CENTRAL NORTH CAROLINA PARTICULARLY WEDNESDAY
NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...BLAES
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
335 AM CST SUN DEC 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CST SUN DEC 1 2013
THE MAIN FOCUS IS ON THE INCREASING CHANCES FOR SNOW
TONIGHT...MAINLY IN SOUTHEAST MINNESOTA...NORTHEAST IOWA AND FAR
WESTERN WISCONSIN.
CURRENTLY...NORTHWESTERLY FLOW ALOFT IS IN PLACE WITH A SURFACE
RIDGE OF HIGH PRESSURE CENTERED ON THE EASTERN DAKOTAS. THE
INITIAL QUESTION THIS MORNING IS WITH A STRATUS DECK THAT EXTENDS
ACROSS NORTHERN WISCONSIN/MINNESOTA AND HOW FAR SOUTH IT WILL MAKE
IT TODAY. THERE HAS NOT BEEN MUCH OF A SOUTHERLY PUSH WITH IT OVER
THE PAST 6 HOURS OR SO...EXCEPT IN EASTERN WISCONSIN ALONG LAKE
MICHIGAN. THE PAST FEW RUNS OF THE HRRR SHOW THIS STRATUS DECK
HAVING TROUBLE MAKING IT SOUTH TODAY AS THE RIDGE OF HIGH PRESSURE
COMES IN AND WEAKENS THE NORTHERLY SURFACE FLOW. IF THIS DECK DOES
MAKE IT FURTHER SOUTH...IT WILL CAUSE TEMPERATURES TO BE ABOUT
5-10F COOLER FOR HIGHS.
GOING INTO TONIGHT...A LEAD/WEAK MID LEVEL SHORT WAVE TROUGH WILL
PROPAGATE EAST ACROSS THE NORTHERN PLAINS WHILE ISENTROPIC LIFT ON
THE 290K SURFACE INCREASES. THIS SHOULD PROVIDE ENOUGH
LIFT...ALBEIT WEAK...TO DEVELOP A BAND OF LIGHT SNOW FROM CENTRAL
MINNESOTA DOWN ALONG THE MISSISSIPPI RIVER. ANY ACCUMULATIONS
OVERNIGHT WILL BE ON THE LIGHT SIDE AT A FEW TENTHS OF AN INCH OR
LESS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM CST SUN DEC 1 2013
LIFT AND MOISTURE WILL BECOME DEEPER MONDAY INTO WEDNESDAY AS THE
CORE OF THE MID LEVEL TROUGH APPROACHES THE REGION. FOR
MONDAY...THE MAIN FOCUS CONTINUES TO BE ALONG THE NOSE OF THE LOW
LEVEL WARM AIR ADVECTION AND WHERE IT WILL SET UP. ALL OF THE
01.00Z GUIDANCE SHOW THE BAND OF PRECIPITATION EXPANDING THROUGH
THE DAY AS THIS ADVECTION STRENGTHENS. HOWEVER...AS WARMER AIR
COMES IN AT THE LOW LEVELS...SOME PRECIPITATION TYPE ISSUES ARISE
WITH THE WARM LAYER POSSIBLY CAUSING THE SNOW TO CHANGE OVER TO
RAIN. SURFACE TEMPERATURES SHOULD ALSO BE ON THE RISE ABOVE
FREEZING...SO AM NOT EXPECTING ANY FREEZING RAIN AT THE MOMENT.
THERE IS SOME UNCERTAINTY TOO WITH THE POSITION OF THE NORTHWEST
TO SOUTHEAST SWATH OF PRECIPITATION WITH THE 01.00Z NAM/01.03Z
SREF BEING THE FARTHEST NORTHEAST WHILE THE 01.00Z GFS/ECMWF
DEVELOP IS MORE TO THE SOUTHWEST IN SOUTHEAST MINNESOTA/NORTHEAST
IOWA. MAY BE UNDER-DOING THE SNOW AMOUNTS ON MONDAY...BUT THE
POTENTIAL MIX HAS ME CAUTIOUS TO GO MUCH ABOVE A FEW TENTHS OF AN
INCH.
THE BIGGEST STORY WITH THE 01.00Z GUIDANCE IS HOW THEY HAVE ALL
COME AROUND TO THIS THINKING OF A MUCH FASTER FRONTAL PASSAGE WITH
THE DEEPENING SURFACE LOW/MID LEVEL TROUGH MOVING THROUGH EARLY ON
WEDNESDAY. THE BEST CHANCES FOR ANY PRECIPITATION APPEARS TO BE
FROM MONDAY NIGHT THROUGH WEDNESDAY AS THIS TROUGH APPROACHES. THE
WARMER AIR COMING IN ON TUESDAY AHEAD OF THE SYSTEM SHOULD KEEP
THE P-TYPE MAINLY AS RAIN UNTIL THE COLD FRONT COMES THROUGH EARLY
ON WEDNESDAY. THE MAIN CHANCES FOR SNOW WILL BE ON MONDAY NIGHT
AHEAD OF THE WARM AIR..AND THEN AGAIN ON WEDNESDAY MORNING BETWEEN
THE LEAD COLD FRONT PASSAGE AND THE SECONDARY COLD FRONT WHICH
USHERS IN THE DRASTICALLY COLDER AIR IN. OVERALL...CONFIDENCE IN
GETTING ANY SPECIFIC DETAILS DOWN ON THE PRECIPITATION TRENDS IS
PRETTY LOW...PARTICULARLY WITH THE SNOW AMOUNTS. IF ANY SNOW IS
ABLE TO OCCUR WEDNESDAY MORNING AFTER THE FIRST FRONT COMES
THROUGH...IT WILL MEAN THAT TEMPERATURES COULD BE COLDER THAN
ADVERTISED GOING THROUGH THE REST OF THE WEEK. DUE TO THE FASTER
FROPA...HAVE DROPPED THE PRECIPITATION CHANCES FROM THURSDAY
INTO THE WEEKEND.
AS FOR THE COLD SPELL...850MB TEMPERATURES ARE FORECAST TO DROP
DOWN TO BETWEEN -15 TO -20C ON THURSDAY WITH THE POOL OF COLD AIR
LASTING THROUGHOUT THE REGION PAST NEXT WEEKEND. EVEN IF THERE IS
NO SNOW COVER DOWN ON THE GROUND...TEMPERATURES WILL BE MUCH
BELOW NORMAL THROUGH THE FORESEEABLE FUTURE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 1115 PM CST SAT NOV 30 2013
BAND OF MID LEVEL CLOUDS CONTINUES TO HANG WEST-EAST ACROSS THE
REGION...MOSTLY 8-12 KFT. HOWEVER...LARGE MVFR STRATUS DECK
CONTINUES TO SINK SOUTHWARD FROM NORTHERN MN/LAKE SUPERIOR. RAP13
FAVORS KEEPING THIS CLOUD DECK TOGETHER...BUT IS ALSO TRENDING
SLOWER WITH REACHING KRST/KLSE...MORE AFTER 15Z NOW. THE GFS/NAM NOT
AS BULLISH ON BRINGING THE MVFR CLOUDS THIS FAR SOUTH...KEEPING MOST
OF THEM TO THE NORTH AND EAST. MEANWHILE THE FOG/STRATUS SATELLITE
IMAGERY SHOWS A LARGE AREA OF STRATUS...WITH CURRENT TIMING EVEN
LATER THAN THE RAP...CLOSER TO 18Z. WILL CONTINUE TO HOLD WITH THE
IDEA THAT THESE MVFR CIGS WILL MAKE IT TO THE KRST/KLSE...BUT WILL
PUSH BACK THE TIMING. SOUNDINGS CONTINUE TO SUGGEST THAT THERE
SHOULD BE ENOUGH MIXING FOR A DIURNAL INCREASE IN CIG HEIGHT BY
18Z...AND POTENTIALLY BECOME SCT AS DRY AIR MIXES IN.
CLOUD FORECAST REMAINS TOUGH. TRENDS WILL HAVE TO BE MONITORED
CLOSELY AND ADJUSTMENTS MADE AS NECESSARY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1039 PM MST SAT NOV 30 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 350 PM MST SAT NOV 30 2013
MAIN CONCERN THROUGH THE SHORT TERM WILL BE WIND SPEEDS...
ESPECIALLY THROUGH THE HIGH WIND CORRIDORS. CONVERSE COUNTY HAS
BEEN ADDED TO THE HIGH WIND WATCH...OTHERWISE NO CHANGES TO THE
HAZARD GRIDS. TIMING OF WHEN WINDS WILL ACTUALLY START HITTING
HIGH WIND CRITERIA IS SOMEWHAT IN QUESTION. ARLINGTON AND BORDEAUX
COULD GET CLOSE LATE TONIGHT THROUGH ABOUT SUNRISE BUT IT LOOKS
LIKE THE MAIN THREAT FOR STRONGER WINDS WILL HOLD OFF UNTIL MONDAY
AFTERNOON WHEN A STRONG UPPER LEVEL JET PUSHES INTO SOUTHEAST
WYOMING. GFS IS FASTER WITH THE ARRIVAL OF THE UPPER JET AND THUS
FASTER RAMPING UP THE STRONG SURFACE WINDS AND THE GFS IS
INDICATING STRONGER WINDS OVERALL. THE NAM IS A GOOD 6 HOURS
SLOWER WITH THE ARRIVAL OF THE STRONGEST WINDS WHICH COULD BE
DELAYED UNTIL AROUND 00Z MONDAY FOR WIND PRONE AREAS. REGARDLESS
IT IS GOING TO BE VERY WINDY SUNDAY NIGHT AND CONTINUE INTO MONDAY
WITH STRONG WINDS SPREADING EAST INTO THE PLAINS.
WINTER STORM WATCH REMAINS IN EFFECT FOR THE SNOWY AND SIERRA
MADRE RANGES. 18Z NAM HAS BACKED OFF THE QPF AMOUNTS OVER THE
MOUNTAINS AND THE GFS IS BARELY GENERATING ANY QPF...OF COURSE THE
MODELS TEND TO UNDER ESTIMATE QPF IN THIS TYPE OF FLOW REGIME.
KEPT THE SNOW AMOUNTS AT THE HIGH END OF THE POTENTIAL RANGE FOR
NOW...BUT IF THE NAM CONTINUE TO TREND DRIER...MAY NEED TO LOWER
AMOUNTS. THE MAIN CONCERN IS THAT EVEN WITH LESSER SNOW AMOUNTS
SUSTAINED WINDS WILL LIKELY HIT 50 MPH WITH HIGHER GUSTS PRODUCING
BLOWING SNOW AND SIGNIFICANT REDUCTION IN VISIBILITIES. TOUGH CALL
BETWEEN A HIGH WIND WARNING...WINTER STORM WARNING OR A WINTER
WEATHER ADVISORY FOR THE MOUNTAINS...OF COURSE THE MAIN CHANCE FOR
HIGH SNOW ACCUMULATIONS OVER THE MOUNTAINS WILL NOT OCCUR UNTIL
TUESDAY AND WEDNESDAY.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 305 PM MST SAT NOV 30 2013
ARCTIC FRONT WILL SWEEP ACROSS THE CWA TUESDAY WITH GFS THE
FASTEST SOLUTION...SOMEWHAT AN OUTLIER WITH MOST OTHER MODELS A
BIT SLOWER. THIS WILL IMPACT MAX TEMPERATURES FOR TUESDAY AS
TEMPERATURES WILL PLUNGE ONCE THE FRONT PASSES. MUCH COLDER
TEMPERATURES EXPECTED FOR THE REST OF THE WEEK UNDER BROAD
CYCLONIC UPPER FLOW. VERY COLD CONDITIONS FOR THURSDAY AND FRIDAY
WHEN HIGHS MAY STRUGGLE TO REACH THE TEENS AS VERY LOW THICKNESSES
PASS ACROSS THE REGION.
PRECIPITATION-WISE...SNOW SHOULD BE ONGOING AT TIMES OVER THE
HIGHER MTNS AND WEST DURING THE DAY TUESDAY THEN POST-FRONTAL
LIGHT SNOWS SHOULD INCREASE OVER THE EASTERN PLAINS TUESDAY
AFTERNOON AND NIGHT AS UPSLOPE FLOW DEEPENS AND MOISTURE
INCREASES. SNOW SHOULD CONTINUE OVER MANY AREAS WEDS THEN TAPER
OFF FROM NORTH TO SOUTH WEDS EVENING AS SFC HIGH BUILDS IN AND
BETTER MOISTURE AND UPSLOPE FLOW SHIFTS SOUTH INTO COLORADO. COULD
BE SOME PRETTY GOOD SNOWFALL AMOUNTS MAINLY OVER AND NEAR THE MTNS
BUT VERY COLD AIRMASS SHOULD LIMIT ACCUMULATIONS SOME. MAINLY DRY
CONDITIONS THEN EXPECTED BY LATE THURSDAY THROUGH SATURDAY OUTSIDE
OF THE HIGHER MTNS WHERE SOME SNOW SHOWERS SHOULD RETURN BY THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 1027 PM MST SAT NOV 30 2013
SCATTERED TO BROKEN MID LEVEL CLOUDS WILL PREVAIL TONIGHT...WITH
MVFR TO IFR CIGS DEVELOPING OVER WESTERN AND SOUTHERN CARBON
COUNTY BY DAYBREAK SUNDAY. NAM MOS AND HRRR HAVE BEEN CONSISTENT
WITH AT LEAST IFR CIGS INVOF KRWL AND KSAA AIRFIELDS. KEPT
PREVAILING BKN015 THROUGH SUNDAY AFTERNOON AT KRWL. SNOW SHOWERS
WILL DEVELOP AND OBSCURE THE SNOWY AND SIERRA MTNS SUNDAY. IT WILL
BE BREEZY TO WINDY SUNDAY WITH WESTERLY WINDS POSSIBLY GUSTING AS
HIGH AS 50 KT FOR THE WIND CORRIDORS OF SOUTHEAST WY. GUSTS TO 35 KT
ARE EXPECTED ELSEWHERE...EXCEPT 25 KT IN WESTERN NEBRASKA.
&&
.FIRE WEATHER...
ISSUED AT 325 AM MST SAT NOV 30 2013
WINDS TO REMAIN BREEZY TODAY AND TONIGHT WITH INCREASING WINDS
THROUGH THE DAY SUNDAY INTO MONDAY. THEY COULD BECOME QUITE STRONG
SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR AREAS ALONG AND WEST
OF THE LARAMIE RANGE AND IMMEDIATELY TO THE EAST HERE NEAR
CHEYENNE AND UP BY WHEATLAND. FORTUNATELY...WE ARE LOOKING AT
AFTERNOON HUMIDITIES TO REMAIN IN THE 20S AND LOW 30S THROUGH
MONDAY WITH FAIR TO EXCELLENT OVERNIGHT RECOVERIES. SNOW WILL
BECOME WIDESPREAD NEXT WEEK FROM TUESDAY THROUGH THURSDAY. MOST
LOCATIONS WILL SEE ACCUMULATING SNOWS AS A LOW PRESSURE SYSTEM
TRACKS THROUGH THE AREA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY AFTERNOON
FOR WYZ112-114.
HIGH WIND WATCH FROM SUNDAY MORNING THROUGH MONDAY AFTERNOON
FOR WYZ106-110-116-117.
HIGH WIND WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON
FOR WYZ101-104-105-107-109-115-118.
NE...NONE.
&&
$$
SHORT TERM...LIEBL
LONG TERM...RE
AVIATION...JAMSKI
FIRE WEATHER...LIEBL
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
951 AM EST SUN DEC 1 2013
.UPDATE...
THE SHERIFF OFFICES AND THE OBSERVATIONS OVER THE INTERIOR AND
WEST COAST METRO AREAS OF SOUTH FLORIDA ARE NOW REPORTING
VISIBILITIES TO BE BETWEEN 1 TO 3 MILES IN THE FOG. SO WILL LET
THE DENSE FOG ADVISORY EXPIRED AT 10 AM EDT THIS MORNING FOR THE
INTERIOR AND WEST COAST METRO AREAS.
THE FOG SHOULD CONTINUE TO BURN OFF THROUGH NOON TIME ALLOWING FOR
THE SKIES TO BECOME PARTLY CLOUDY BY THIS AFTERNOON ALONG WITH DRY
WEATHER. SO WILL SHOW A TREND OF CLEARING SKIES ALONG WITH DRY
CONDITIONS FOR THE INTERIOR AND WEST COAST METRO AREAS.
FOR THE EAST COAST METRO AREAS...THERE HAS BEEN SOME ISOLATED
SHOWERS WORKING INTO THIS AREA FROM THE ATLANTIC WATERS. THE
ISOLATED SHOWERS WILL CONTINUE TO WORK INTO THE EAST COAST METRO
AREAS THROUGH THE AFTERNOON HOURS ON THE EASTERLY WIND FLOW. SO
WILL KEEP A SLIGHT CHANCE OF SHOWERS IN PLACE FOR THE EAST COAST
METRO AREAS THROUGH THIS AFTERNOON.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED.
&&
.UPDATE...54/BNB
.PREV DISCUSSION... /ISSUED 642 AM EST SUN DEC 1 2013/
AVIATION...
REDUCED VSBYS IN FOG ARE MAINLY IMPACTING THE APF SITE THIS
MORNING AND INLAND OF THE EAST COAST TERMINALS. THIS SHOULD BURN
OFF BY OR BETWEEN 8-9AM WITH VFR CONDITIONS RETURNING. THE BEST
CHANCE OF SHOWERS WILL BE ALONG THE EAST COAST TODAY...WHICH WILL
BE CAPABLE OF PRODUCING PERIODS OF REDUCED CIGS/VSBYS THROUGH THE
DAY. WINDS WILL REMAIN OUT OF THE NORTHEAST AND INCREASE TO AROUND
10 KT THROUGH THE LATE MORNING AND AFTERNOON HOURS. ALTHOUGH
CONFIDENCE REMAINS TOO LOW...WINDS COULD SHIFT TO THE WNW AT APF
DUE A GULF COAST SEA BREEZE THROUGH THE AFTERNOON PERIOD. WILL
MONITOR THIS AND UPDATE IF NEEDED.
&&
PREV DISCUSSION... /ISSUED 319 AM EST SUN DEC 1 2013/
DISCUSSION...
HIGH PRESSURE TO THE NORTH CONTINUES TO BRING NORTHEASTERLY FLOW
TO SOUTH FLORIDA. HOWEVER, THE HIGH WILL BEGIN TO WEAKEN TODAY,
ALLOWING THE WINDS TO BECOME LIGHTER. THERE IS STILL A FEW SHOWERS
OVER THE ATLANTIC WATERS. CURRENTLY, THEY ARE NOT IMPACTING THE
CWA, BUT STILL HAVE A SLIGHT CHANCE IN THE FORECAST. THE HRRR DOES
SHOW SOME ISOLATED SHOWERS OVER THE ATLANTIC COAST METRO AREAS
THIS AFTERNOON, SO BROUGHT SLIGHT CHANCE POPS SOMEWHAT MORE WEST.
MODELS STILL SHOWING A VERY WEAK FRONT PUSHING SOUTH THROUGH SOUTH
FLORIDA TOMORROW, BUT LOOKS BARELY DISCERNIBLE IN THE MODELS. GFS
HAS HIGH PRESSURE BUILDING OVER THE FLORIDA PENINSULA BY 00Z
TUESDAY WITH NO PRECIPITATION AT ALL. THE ECMWF IS SIMILAR, BUT
ABOUT 6 HOURS SLOWER WITH MORE BROAD WEAK HIGH PRESSURE BUILDING.
EITHER WAY. THE BEST EVIDENCE OF THIS FRONT WILL LIKELY BE A WEAK
WINDS SHIFT TOMORROW. BUT, LEFT A SLIGHT CHANCE OF SHOWERS ACROSS
THE CWA FOR THE AFTERNOON HOURS. BUT, GIVEN CURRENT MODEL RUNS,
COULD DEFINITELY SEE THIS BEING PULLED OUT OF THE FORECAST LATER
TODAY.
AFTER TOMORROW, IT IS HIGH PRESSURE FOR THE REMAINDER OF THE
FORECAST PERIOD. THE AIR MASS WILL WARM VERY SLIGHTLY THROUGH THE
WEEK, WITH PERHAPS A FEW LIGHT COASTAL SHOWERS POSSIBLE,
ESPECIALLY IN THE OVERNIGHT HOURS.
AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY
MORNING HOURS. HOWEVER...AN AREA OF CLOUDINESS AND EMBEDDED
SHOWERS IS MOVING WESTWARD INTO THE LOCAL ATLANTIC WATERS AND A FEW
SHOWERS COULD IMPACT THE EAST COAST TERMINALS FROM TIME TO TIME.
ONLY PASSING SHOWERS EXPECTED BUT WILL AMEND IF ANY VIS/CEILING
RESTRICTIONS OCCUR BUT NOT EXPECTED. WINDS ACROSS THE EAST COAST
TERMINALS STARTING TO BECOME LIGHT AND VARIABLE WITH AN OFF SHORE
DRAINAGE FLOW BEGINNING.
MARINE...
HIGH PRESSURE TO THE NORTH WILL WEAKEN TODAY, BUT STILL KEEP
EASTERLY FLOW OVER THE COASTAL WATERS. THE WEAKER WINDS WILL
RESULT IN SEAS CONTINUING TO SUBSIDE TODAY. GIVEN THIS ALL
ADVISORIES AND CAUTION STATEMENTS HAVE BEEN CANCELLED. THERE IS A
SLIGHT CHANCE OF SHOWERS OVER THE NEXT COUPLE OF DAYS AS A VERY
WEAK COLD FRONT SLIDES ACROSS THE AREA TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 63 77 61 / 20 10 10 -
FORT LAUDERDALE 79 64 77 63 / 20 10 10 -
MIAMI 80 65 78 63 / 20 10 10 -
NAPLES 77 63 75 62 / - - 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR COASTAL
COLLIER-GLADES-HENDRY-INLAND BROWARD-INLAND COLLIER-INLAND
PALM BEACH.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
642 AM EST SUN DEC 1 2013
.AVIATION...
REDUCED VSBYS IN FOG ARE MAINLY IMPACTING THE APF SITE THIS
MORNING AND INLAND OF THE EAST COAST TERMINALS. THIS SHOULD BURN
OFF BY OR BETWEEN 8-9AM WITH VFR CONDITIONS RETURNING. THE BEST
CHANCE OF SHOWERS WILL BE ALONG THE EAST COAST TODAY...WHICH WILL
BE CAPABLE OF PRODUCING PERIODS OF REDUCED CIGS/VSBYS THROUGH THE
DAY. WINDS WILL REMAIN OUT OF THE NORTHEAST AND INCREASE TO AROUND
10 KT THROUGH THE LATE MORNING AND AFTERNOON HOURS. ALTHOUGH
CONFIDENCE REMAINS TOO LOW...WINDS COULD SHIFT TO THE WNW AT APF
DUE A GULF COAST SEA BREEZE THROUGH THE AFTERNOON PERIOD. WILL
MONITOR THIS AND UPDATE IF NEEDED.
&&
.PREV DISCUSSION... /ISSUED 319 AM EST SUN DEC 1 2013/
DISCUSSION...
HIGH PRESSURE TO THE NORTH CONTINUES TO BRING NORTHEASTERLY FLOW
TO SOUTH FLORIDA. HOWEVER, THE HIGH WILL BEGIN TO WEAKEN TODAY,
ALLOWING THE WINDS TO BECOME LIGHTER. THERE IS STILL A FEW SHOWERS
OVER THE ATLANTIC WATERS. CURRENTLY, THEY ARE NOT IMPACTING THE
CWA, BUT STILL HAVE A SLIGHT CHANCE IN THE FORECAST. THE HRRR DOES
SHOW SOME ISOLATED SHOWERS OVER THE ATLANTIC COAST METRO AREAS
THIS AFTERNOON, SO BROUGHT SLIGHT CHANCE POPS SOMEWHAT MORE WEST.
MODELS STILL SHOWING A VERY WEAK FRONT PUSHING SOUTH THROUGH SOUTH
FLORIDA TOMORROW, BUT LOOKS BARELY DISCERNIBLE IN THE MODELS. GFS
HAS HIGH PRESSURE BUILDING OVER THE FLORIDA PENINSULA BY 00Z
TUESDAY WITH NO PRECIPITATION AT ALL. THE ECMWF IS SIMILAR, BUT
ABOUT 6 HOURS SLOWER WITH MORE BROAD WEAK HIGH PRESSURE BUILDING.
EITHER WAY. THE BEST EVIDENCE OF THIS FRONT WILL LIKELY BE A WEAK
WINDS SHIFT TOMORROW. BUT, LEFT A SLIGHT CHANCE OF SHOWERS ACROSS
THE CWA FOR THE AFTERNOON HOURS. BUT, GIVEN CURRENT MODEL RUNS,
COULD DEFINITELY SEE THIS BEING PULLED OUT OF THE FORECAST LATER
TODAY.
AFTER TOMORROW, IT IS HIGH PRESSURE FOR THE REMAINDER OF THE
FORECAST PERIOD. THE AIR MASS WILL WARM VERY SLIGHTLY THROUGH THE
WEEK, WITH PERHAPS A FEW LIGHT COASTAL SHOWERS POSSIBLE,
ESPECIALLY IN THE OVERNIGHT HOURS.
AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY
MORNING HOURS. HOWEVER...AN AREA OF CLOUDINESS AND EMBEDDED
SHOWERS IS MOVING WESTWARD INTO THE LOCAL ATLANTIC WATERS AND A FEW
SHOWERS COULD IMPACT THE EAST COAST TERMINALS FROM TIME TO TIME.
ONLY PASSING SHOWERS EXPECTED BUT WILL AMEND IF ANY VIS/CEILING
RESTRICTIONS OCCUR BUT NOT EXPECTED. WINDS ACROSS THE EAST COAST
TERMINALS STARTING TO BECOME LIGHT AND VARIABLE WITH AN OFF SHORE
DRAINAGE FLOW BEGINNING.
MARINE...
HIGH PRESSURE TO THE NORTH WILL WEAKEN TODAY, BUT STILL KEEP
EASTERLY FLOW OVER THE COASTAL WATERS. THE WEAKER WINDS WILL
RESULT IN SEAS CONTINUING TO SUBSIDE TODAY. GIVEN THIS ALL
ADVISORIES AND CAUTION STATEMENTS HAVE BEEN CANCELLED. THERE IS A
SLIGHT CHANCE OF SHOWERS OVER THE NEXT COUPLE OF DAYS AS A VERY
WEAK COLD FRONT SLIDES ACROSS THE AREA TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 62 78 61 / 20 10 10 -
FORT LAUDERDALE 80 64 78 63 / 20 10 10 -
MIAMI 80 64 79 63 / 20 10 10 -
NAPLES 78 63 76 62 / - - 10 -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...DENSE FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR GLADES-HENDRY-
INLAND BROWARD-INLAND COLLIER-INLAND PALM BEACH.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
804 AM CST SUN DEC 1 2013
.DISCUSSION...
302 AM CST
TODAY...
LOW PRESSURE IS SKIRTING EAST ACROSS THE CENTRAL GREAT LAKES WITH A
TRAILING COLD FRONT SAGGING SOUTH ACROSS THE CENTRAL PART OF THE CWA
EARLY THIS MORNING. A FEW RADAR RETURNS TO OUR NORTH MAINLY
ASSOCIATED WITH MID LEVEL CLOUD COVER...AND PRECIP IS NOT MAKING ITS
WAY TO THE SURFACE...NOR IS IT EXPECTED TO AS THE FRONT CONTINUES TO
SLIP ACROSS THE CWA THROUGH THE MORNING. STRATUS DECK IS EVIDENT ON
IR IMAGERY BUILDING SOUTH BEHIND THE FRONT. EXPECT THESE LOWER
CLOUDS TO BUILD ACROSS THE FORECAST AREA LATER THIS MORNING THEN
REMAIN IN PLACE THROUGH THE DAY AND TONIGHT. WEAK HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE AREA TONIGHT...THOUGH MODEL RH FIELDS
SHOW LITTLE IF ANY DISSIPATION OF THE STRATUS DECK. ASSUMING WE STAY
CLOUDY OVERNIGHT...TEMPERATURES SHOULD STAY PROPPED UP INTO THE
UPPER 20S TO LOW 30S DESPITE WINDS LIKELY GOING VERY LIGHT OR
CALM. HOWEVER...IF WE DO SEE CLEARING...WILL HAVE TO MAKE HEFTY
CHANGES TO OVERNIGHT LOWS WHICH COULD FALL 10+ DEGREES MORE THAN
CURRENTLY FORECAST UNDER A STRONG RADIATIONAL COOLING SETUP.
MONDAY...
UPPER LOW DIGS FROM BRITISH COLUMBIA INTO THE PACIFIC NORTHWEST THIS
PERIOD WHILE A LEAD WAVE KICKS EAST ACROSS THE NORTHERN PLAINS WITH
SURFACE LOW UNDERGOING CYCLOGENESIS. ECMWF NO LONGER ADVERTISING
SHORTWAVE EARLY MONDAY...WHICH IS IN LINE WITH OTHER MODEL SOLUTIONS
THUS PULLED MENTION OF POPS MONDAY. BY MONDAY EVENING...H85
BAROCLINIC ZONE SETS UP FROM THE DAKOTAS INTO THE MID MISSISSIPPI
VALLEY WITH A ZONE OF ISENTROPIC ASCENT FOCUSED JUST TO OUR WEST.
STILL UNCERTAIN HOW FAR EAST THE PRECIP WILL EXTEND...BUT BEST
CHANCES WILL BE IN THE NORTHWESTERN PORTIONS OF THE CWA AROUND
ROCKFORD. PRECIP MAY START OFF AS RAIN SNOW MIX...BUT SHOULD
TRANSITION TO ALL RAIN AS THE WARM AIR CONTINUES TO PUSH NORTHWARD.
TEMPERATURES MAY RISE OVERNIGHT MONDAY NIGHT ACROSS PORTIONS IF NOT
ALL OF THE CWA DEPENDING ON HOW QUICKLY THE WARM FRONT LIFTS ACROSS
THE AREA.
TUESDAY THROUGH WEDNESDAY...
LONGWAVE TROUGH CONTINUES TO DEEPEN ACROSS THE WESTERN CONUS WITH
DOWNSTREAM AMPLIFICATION OF THE RIDGE ACROSS THE CENTRAL CONUS.
SURFACE LOW PROGGED TO TRACK FROM THE DAKOTAS INTO THE NORTHERN
LAKES REGION THROUGH THE PERIOD WITH STRONG WARM ADVECTION AHEAD OF
THE LOW WARMING H85 TEMPS TO AROUND 7-8C TUE/WED. 01/00Z EMCWF
ACTUALLY THROWING A WRENCH INTO PREVIOUS FORECAST THINKING FOR
THIS SYSTEM MIDWEEK...TRENDING MUCH FASTER AND MORE IN LINE WITH
THE GFS. NOT QUITE READY TO BITE OFF ON THIS COMPLETELY AS OFTEN
TIMES WITH CLOSED UPPER LOWS SLOWER MODEL SOLUTIONS TEND TO BE
BETTER...AND WOULD NOT BE SURPRISED TO SEE THE GFS AND ECMWF TREND
SLOWER IN THE NEXT COUPLE DAYS. TEMPERATURES ON WEDNESDAY A BIT
TRICKY WITH BIG BUST POTENTIAL. SLIGHTLY FASTER OR SLOWER FROPA
WILL RESULT IN A 15-20 DEGREE RANGE OF POSSIBLE TEMPERATURES.
ECMWF CONTINUES TO BE AGGRESSIVE WITH TEMPERATURES AHEAD OF THE
FRONT...SUGGESTING MID TO UPPER 50S ACROSS MUCH OF THE EASTERN
HALF OF THE CWA EVEN WITH FASTER FROPA. THE GEM...WHICH IS SLOWER
THAN THE GFS/ECMWF NOW SUGGESTING LOW TO MID 60S WEDNESDAY.
TRENDED SLIGHTLY WARMER ACROSS THE EASTERN CWA WHICH WILL HAVE THE
BEST LIKELIHOOD OF SEEING FULL WARMTH AHEAD OF THE FRONT.
THURSDAY THROUGH SATURDAY...
BY THURSDAY...H85 TEMPS SHOULD QUICKLY FALL TO AROUND -10C...THEN
FURTHER COOL TO AROUND -15C TO -18C SATURDAY AS A COLD ARCTIC
AIRMASS TRICKLES INTO THE REGION. BOTH THE GFS AND ECMWF INDICATE
A SERIES OF WAVES LIFTING NORTHEAST ALONG THE FRONT CAUSING PRECIP
NORTH OF THE FRONT AND POSSIBLY IMPACTING EASTERN PORTIONS OF THE
CWA THURSDAY AND THURSDAY NIGHT. OTHERWISE...STRONG HIGH PRESSURE
OVER THE NORTHERN PLAINS WILL BUILD SOUTHEAST WITH RIDGING IN
PLACE FRIDAY INTO THE WEEKEND BRINGING MORE SETTLED AND COLD
WEATHER...WITH HIGHS IN THE TEENS TO LOW 20S...AND SINGLE DIGIT
LOWS FRIDAY AND SATURDAY.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* MVFR CIGS THROUGH MID-DAY AND MAY LINGER INTO TONIGHT.
JEE
//DISCUSSION...UPDATED 12Z...
COLD FRONT HAS JUST MOVED THROUGH TERMINALS EARLY THIS MORNING AND
WILL CONTINUE TO TRACK OFF TO THE SOUTHEAST TODAY. LIGHT WINDS
LESS THAN 10 KT INITIALLY SHIFTING NNW EXPECTED TO BECOME NORTH OR
NE LATER THIS MORNING. WITH THIS SWITCH TO NNE WINDS...CONCERN
BECOMES LARGE AREA OF MVFR STRATUS OVER NORTHERN LAKE MICHIGAN
WHICH MODEL GUIDANCE CONTINUES TO INDICATE WILL MOVE INTO THE
TERMINALS BY MID-DAY. CEILINGS UPSTREAM RANGE FROM 1500-3500 FT
CURRENTLY...THOUGH AREA OF 2500 FT STRATUS ALONG THE EAST SHORE OF
THE LAKE APPEARS TO BE BUILDING SOUTHWEST SIMILAR TO MODEL
FORECASTS AND IS EXPECTED INTO ORD/MDW AREA 16-18Z. WEAK HIGH
PRESSURE DEVELOPS ACROSS THE AREA TONIGHT...MAINTAINING LIGHT NNE
WINDS. LACK OF STRONG SUBSIDENCE OR STRONGER LOW LEVEL WINDS
RAISES QUESTION OF HOW LONG MVFR DECK WILL HANG AROUND. MODELS
DIFFER IN THEIR SOLUTIONS WHICH LOWERS CONFIDENCE. HAVE MAINTAINED
MVFR CIGS THROUGH THE NIGHT WHICH MAY BE ON THE PESSIMISTIC SIDE.
ONCE SURFACE HIGH PASSES AND WINDS VEER SOUTHEAST MONDAY
MORNING...IT DOES APPEAR THAT LOWER CLOUDS SHOULD SCATTER...WHILE
VFR CLOUDS INCREASE.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN CIG TRENDS.
* LOW CONFIDENCE IN HOW LONG MVFR...ESPECIALLY BKN014 CIGS...WILL
LAST.
* HIGH CONFIDENCE IN ALL OTHER FORECAST PARAMETERS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR PROBABLE. CHANCE OF -RASN.
TUESDAY INTO WEDNESDAY...MVFR CIGS POSSIBLE. CHANCE OF RAIN
ESPECIALLY WEDNESDAY.
THURSDAY...SLGT CHANCE OF SHSN WITH MVFR VSBY. OTHERWISE MAINLY
VFR.
FRIDAY AND SATURDAY...MAINLY VFR.
RATZER
&&
.MARINE...
252 AM CST
MAIN MARINE FORECAST CONCERNS FOCUS ON DEVELOPMENT OF STRONG LOW
PRESSURE OVER THE PLAINS MONDAY-TUESDAY...WHICH THEN IS EXPECTED TO
LIFT NORTHEAST ACROSS THE NORTHERN LAKES ON WEDNESDAY. THERE
CONTINUES TO BE SOME SPREAD IN MODEL SOLUTIONS WITH THE DEPTH...
TRACK AND TIMING OF THE LOW.
WEAK LOW PRESSURE WAS OVER LOWER MICHIGAN STATE EARLY THIS
MORNING...WITH A COLD FRONT TRAILING ACROSS SOUTHERN LAKE MICHIGAN.
THE LOW WILL CONTINUE TO TRACK EAST ACROSS THE EASTERN LAKES THROUGH
THIS EVENING...WITH THE FRONT PUSHING SOUTHEAST OF LAKE MICHIGAN
LATER THIS MORNING. WEAK HIGH PRESSURE RIDGING WILL THEN MOVE ACROSS
THE WESTERN LAKES LATER TODAY/TONIGHT...DRIFTING SLOWLY OFF TO THE
EAST ON MONDAY. WITH A RELATIVELY WEAK PUSH TO THE FRONT TODAY...
WINDS WILL SHIFT TO THE NORTH AT GENERALLY LESS THAN 15 KT.
FORECAST MODELS CONTINUE TO DEPICT AN AREA OF LOW PRESSURE
DEVELOPING ACROSS THE HIGH PLAINS BY EARLY MONDAY...WHICH THEN
DEEPENS ACROSS THE CENTRAL PLAINS MONDAY NIGHT. VARIOUS MODEL
SOLUTIONS CONTINUE TO SHOW DIFFERENCES WITH THE EVOLUTION OF THIS
LOW THROUGH MID-WEEK...THOUGH THERE IS SOME CONSENSUS IN LIFTING THE
LOW NORTHEAST ACROSS THE NORTHERN GREAT LAKES WEDNESDAY. GENERALLY
HAVE CONTINUED TO FOLLOW THE SLOWER SOLUTIONS OF THE ECMWF/GEM/UKMET
WITH THIS SYSTEM...THOUGH WILL HAVE TO SEE SOME OF THE DIFFERENCES
IRONED OUT BEFORE CONFIDENCE INCREASES IN DETAILS OF STRENGTH/TRACK
AND TIMING. IT DOES APPEAR THAT THE POTENTIAL EXISTS FOR SOUTHEAST
30-35 KT WINDS AHEAD OF THE LOW LATE TUESDAY INTO WEDNESDAY...AND
WEST GALES LATER WEDNESDAY INTO THURSDAY WITH THE PASSAGE OF THIS
STORM. STILL 3-4 DAYS OUT SO WILL NOT HAVE ANY HEADLINES...THOUGH
WILL MENTION POSSIBLE GALES IN FORECAST FOR THIS PERIOD.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
542 AM CST Sun Dec 1 2013
.DISCUSSION...
ISSUED 248 AM CST Sun Dec 1 2013
Main forecast challenge focuses on departing storm system for the
middle and end of the week...and whether or not it will produce
any wintry precipitation across central Illinois.
SHORT TERM...Today through Tuesday
Weak cold front currently across northern Illinois will sink
southward today, eventually becoming stationary along the Ohio
River by evening. Front will be accompanied by little in the way
of sensible weather other than a shift in the wind. Low-level
moisture seen on IR/fog satellite across southeast Missouri/far
southern Illinois is progged by HRRR to remain mostly south of
I-70 today, while patchy mid-level clouds over Iowa into far
northern Illinois stay mostly north of the area. End result will
be mostly sunny skies until later this afternoon when clouds begin
to approach from the northwest. High temperatures will be bit
cooler behind the cold front, ranging from the middle 40s far
northwest around Galesburg to the lower 50s south of I-70.
Boundary will remain in place along the Ohio River through Monday,
before lifting back northward in response to rising upper-level
heights Monday night into Tuesday. Models continue to show a
subtle short-wave rippling eastward out of the Plains late Sunday
night into Monday that could interact with the front to produce
scattered light showers. Forecast soundings remain dry at
low-levels: however, think forcing will be strong enough to
mention a slight chance for showers on Monday. As front lifts
northward, rain chances will shift into the southern Great Lakes
on Tuesday. Brisk southerly winds south of the departing warm
front will bring much warmer air into the region, with Tuesday
afternoon highs reaching the lower to middle 50s.
LONG TERM...Wednesday through Saturday
Forecast becomes more challenging in the extended, as upper low
currently over northwest British Columbia drops southward and
carves a deep trough across the western CONUS by the middle of the
week. Downstream ridging will place the Midwest/Great Lakes in a
broad southwesterly flow pattern, leading to increased precip
chances Wednesday into Thursday. Models have been struggling with
the evolution of a surface low pressure system and its associated
cold front for the past several runs: however, the 00z DEC 1 run
seems to be coming into better agreement. While GFS remains a fast
outlier, the latest ECMWF has sped up the front quite a bit.
Following an ECMWF/GEM consensus yields FROPA across central
Illinois on Wednesday followed by sharply colder conditions for
the end of the week. Main question will be how much precip will
hold back in the colder airmass Thursday and possibly Friday.
Previous runs of the ECMWF had featured quite a bit of wintry
precip Thursday night into Friday as a secondary wave of low
pressure tracked along the departing front. While it still shows the
potential for wintry precip, it has backed off/shifted E/SE with
its latest solution. GEM seems to be the most consistent model
over the past couple of days, so have trended toward its solution.
With cold front passing on Wednesday, will mention a chance for
showers. After FROPA, precip will largely shut off Wednesday
night, before a wave of low pressure tracking from the lower
Mississippi River Valley into the Ohio River Valley brings a
renewed round of precip primarily across the eastern half of the
KILX CWA on Thursday/Thursday night. Have focused highest POPs
along/east of I-57 for both Thursday and Thursday night, tapering
down to just slight chances further west along/west of the
Illinois River. Precip type during the day Thursday will be rain
across the east, with a rain/snow mix along I-55 and mostly light
snow in the Illinois River Valley. As deeper layer of cold air
arrives, precip will change to light snow across the board
Thursday night, with a light accumulation possible. After that,
will hold on to low chance POPs for snow across the far E/SE on
Friday, although if trends continue, these may need to be dropped
entirely. Main weather story for the end of the week will be the
much colder conditions. Highs by Friday and Saturday will only be
in the 20s, with overnight lows in the single digits and teens.
&&
.AVIATION...
ISSUED 535 AM CST Sun Dec 1 2013
Will see a few hours of MVFR vsbys in fog early this morning, then
VFR conditions are expected into this evening, before another threat
for some lower vsbys in fog late tonight. A weak cold front was
pushing across the forecast area early this morning with winds
ahead of the front light southwesterly, and light northwest to north
winds were reported behind the boundary. forecast soundings and
time-height cross sections indicate other than some sct-bkn cirrus
at times today, not much in the way of significant cloud cover
expected until this evening when a weak weather system well out to
our west spreads clouds into our area. Cig heights look to be
from 8000-1000 feet AGL later this evening. Due to the very light
wind regime and despite the expected cloud cover tonight, we do
expect some light fog to develop after 06z over most of the area
with short range ensembles suggesting areas around I-74 seeing
the higher probabilities for lower vsbys due to the fog. For now,
will bring vsbys down to 4-5sm in br late tonight.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1005 AM EST SUN DEC 1 2013
.UPDATE...
NEAR TERM FOR THE REST OF TODAY HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 329 AM EST SUN DEC 1 2013
A WEAK COLD FRONT WILL MOVE INTO THE REGION FROM THE NORTH LATER
TODAY...EVENTUALLY STALLING OUT NEAR THE OHIO RIVER EARLY MONDAY
BEFORE RETURNING NORTH AS A WARM FRONT. CLOUDS WILL INCREASE TODAY
AND TONIGHT...WITH A FEW RAIN SHOWERS DEVELOP ON MONDAY AS THE FRONT
LIFTS BACK NORTH. STRONG LOW PRESSURE WILL TRACK INTO THE GREAT
LAKES BY LATE WEDNESDAY...WITH A TRAILING COLD FRONT CROSSING
THROUGH THE OHIO VALLEY INTO WEDNESDAY NIGHT AND THURSDAY AND
BRINGING RAIN TO THE REGION. MUCH COLDER AIR WILL SPILL INTO CENTRAL
INDIANA BEHIND THE FRONT...WITH THE POTENTIAL FOR PRECIPITATION TO
END AS SNOW LATE WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1005 AM EST SUN DEC 1 2013
EXTENSIVE AREA OF STRATUS WAS ALONG AND SOUTH OF A VINCENNES TO
GREENSBURG LINE WHILE MOSTLY CLEAR CONDITIONS WERE TO THE NORTH.
HOWEVER AN AREA OF HIGH CLOUDS WAS SPREADING INTO OUR FAR NORTH.
A WEAK AND DIFFUSE COLD FRONT WILL MOVE SOUTH ACROSS OUR REGION AND
STALL OVER SOUTH CENTRAL SECTIONS BY THIS EVENING.
THE MAIN CHANGES TO THIS FORECAST WILL BE TO REDUCE CLOUD COVER AS
STRATUS TO OUR SOUTH HAS SHOWN NO PROGRESSION NORTHWARD AND RUC
SOUNDINGS INDICATE THIS COULD BREAK UP LATER TODAY. EXPECT MOST
AREAS NORTH AND CENTRAL TO START OUT MOSTLY SUNNY WITH PARTLY CLOUDY
CONDITIONS ALL AREAS LATE TODAY.
GIVEN THAT THERE WILL BE MORE SUNSHINE THAN PREVIOUSLY EXPECTED AND
BASED ON RUC 2 METER TEMPERATURES...WILL RAISE HIGH TEMPERATURES
TODAY ABOUT 3 DEGREES THAN WHAT PREVIOUSLY FORECASTED.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 329 AM EST SUN DEC 1 2013
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES WITH THE BOUNDARY IN THE
REGION LATE TONIGHT INTO EARLY TUESDAY.
THE FRONT WILL BECOME NEARLY STATIONARY ACROSS THE REGION TONIGHT
INTO EARLY MONDAY AS A BROADER WAVE ALOFT TRACKS OUT OF THE CENTRAL
PLAINS AND INTO THE OHIO AND TENNESSEE VALLEYS BY MONDAY MORNING.
MODEL SOUNDINGS INDICATING THE DEVELOPMENT OF A SHARP BUT SHALLOW
INVERSION IN THE LOWEST 1-2KFT OVERNIGHT WITH THE LIKELIHOOD OF A
LOW STRATUS DECK BECOMING WELL ESTABLISHED. HOWEVER WITH DRIER AIR
PRESENT FURTHER UP THROUGH THE BOUNDARY LAYER...THINK THE MOIST
LAYER WILL REMAIN TOO SHALLOW TO SUPPORT ANY
PRECIP/DRIZZLE/SPRINKLES OVERNIGHT...AND HAVE REMOVED PRECIP
CHANCES THROUGH DAYBREAK MONDAY.
BEST CHANCE FOR A FEW RAIN SHOWERS LIKELY COMES MONDAY WITH SLIGHTLY
BETTER FORCING ALOFT COURTESY OF THE AFOREMENTIONED UPPER WAVE AND
PRESENCE OF DEEPER MOISTURE. LOWER LEVELS SHOULD WARM ENOUGH TO
ALLOW PRECIP TO FALL AS ALL RAIN OVER FAR NORTHERN COUNTIES MONDAY
MORNING. RAINFALL AMOUNTS WILL BE ONLY A FEW HUNDREDTHS AT BEST AND
THE SPARSE NATURE OF THE RAIN SHOWERS WILL MEAN SOME LOCATIONS
PROBABLY SEE NO PRECIP AT ALL. WILL MAINTAIN ONLY LOW CHANCE POPS
INTO MONDAY EVENING.
THE FRONT WILL LIFT NORTH OF THE REGION LATE MONDAY NIGHT IN
RESPONSE TO LOW PRESSURE EJECTING OUT OF THE PACIFIC NORTHWEST AND
INTO THE NORTHERN PLAINS BY TUESDAY MORNING. GUIDANCE CONTINUING TO
VARY ON THE HANDLING OF THE SHARP POLAR VORTEX DIVING THROUGH THE
NORTHERN ROCKIES AND THE OVERALL COMPLEX NATURE OF THE UPPER LEVEL
FLOW. ONE TREND NOTED OVER THE LAST FEW MODEL RUNS HOWEVER IS A
GENERAL CONSENSUS TOWARDS A FASTER EASTWARD PROGRESSION TO THE
SURFACE WAVE AND ASSOCIATED COLD FRONT. THE OP GFS IS MOST
PROGRESSIVE AND HAS SUPPORT FROM ITS ENSEMBLE MEMBERS...BUT APPEARS
TO DAMPEN DOWNSTREAM UPPER RIDGING TOO QUICKLY. PREFER THE GROWING
CONSENSUS PRESENTED BY THE OTHER MODELS WITH THE COLD FRONT QUICKLY
APPROACHING THE MISSISSIPPI VALLEY BY WEDNESDAY MORNING. COULD SEE
RAIN SHOWERS DEVELOP AS EARLY AS TUESDAY NIGHT AS A LOW LEVEL JET
MOVES INTO THE OHIO VALLEY.
TEMPS...UNDERCUT AGGRESSIVE MOS GUIDANCE OVERALL FOR MONDAY HIGHS
WITH PRESENCE OF CLOUDS AND PRECIP LIKELY LIMITING WARMING. THE
EXPANSION OF STRONG WARM ADVECTION SOUTH OF THE WARM FRONT ON
TUESDAY SETTING THE STAGE FOR A MILD DAY EVEN DESPITE EXPECTED CLOUD
COVER. MOS AGAIN LOOKED SOMEWHAT AGGRESSIVE...BUT A SEVERAL DEGREE
BUMP IN TEMPS IS WARRANTED WITH THE ENTIRE AREA INTO THE MID/UPPER
50S. CLOSER TO THE WARMER MAVMOS TONIGHT WITH CLOUDS...THEN NEAR
MOS FOR LOWS MONDAY/TUESDAY NIGHTS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 329 AM EST SUN DEC 1 2013
ENSEMBLES ARE IN GOOD AGREEMENT ON THE EVOLVING WEATHER PATTERN
LATER THIS WEEK. MEAN UPPER TROUGHING EXPECTED FROM THE NORTHERN
PLAINS BACK INTO THE SOUTHWEST...WHILE UPPER RIDGING DEVELOPS OVER
THE SOUTHEAST. 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 WEDNESDAY. WILL KEEP SOME
RAIN CHANCES IN THE FORECAST FOR WEDNESDAY AS THE UPPER DISTURBANCE
MOVES THROUGH.
AFTER THAT...FORECAST BECOMES MORE MUDDLED AS THE POTENTIAL EXISTS
FOR WAVES TO EJECT OUT OF THE WESTERN TROUGH. AT THIS POINT...THE
ENSEMBLES DON/T INDICATE ANY MAJOR LOW PRESSURE SYSTEMS...BUT RATHER
STABLE TYPE SURFACE WAVES RIPPLING ALONG A PRIMARY FRONTAL ZONE
LOCATED OVER THE TENNESSEE VALLEY. ENSEMBLES SEEM TO KEY IN ON ONE
WAVE MOVING THROUGH AROUND THURSDAY INTO EARLY FRIDAY...AND ANOTHER
JUST AFTER THIS FORECAST PERIOD. ALTHOUGH AN ARGUMENT CAN BE MADE
FOR AT LEAST SOME PRECIPITATION THREAT EVERY DAY...FOR NOW WILL KEEP
THE POPS RESTRICTED TO THURSDAY AND FRIDAY. APPEARS THERE IS
POTENTIAL FOR SOME LIGHT SNOW ACCUMULATIONS THURSDAY NIGHT INTO
FRIDAY MORNING.
&&
.AVIATION /DISCUSSION FOR THE 011500Z TAF UPDATE/...
ISSUED AT 921 AM EST SUN DEC 1 2013
KIND TAF IS GOOD. ONLY MINOR TWEAKS MADE. LOOKS LIKE KIND WILL
REMAIN IN BETWEEN BKN050 DECK TO THE SOUTHEAST AND BKN150 DECK TO
THE NORTHWEST INTO THE AFTERNOON.
PREVIOUS DISCUSSION FOLLOWS...
VFR CEILINGS AROUND 050 CURRENTLY IN THE KBMG AREA SHOULD SCATTER
OUT BY ISSUANCE TIME.
OTHERWISE...WEAK FRONTAL SYSTEM EXPECTED TO DROP SOUTHEAST ACROSS
THE TAF SITES IN THE 011800Z-020000Z TIME FRAME...ACCOMPANIED BY A
GRADUAL WIND SHIFT TO 320-350 DEGREES. WIND SPEEDS SHOULD GENERALLY
REMAIN UNDER 10 KTS ACROSS THE FRONT.
FRONT SHOULD BE INACTIVE FOR THE MOST PART...OTHER THAN THE FACT
THAT IT WILL HELP PULL DOWN SOME OF THE MVFR CEILINGS AROUND 025
CURRENTLY OVER THE GREAT LAKES LATER THIS AFTERNOON AND EARLY THIS
EVENING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...JH
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...JAS/50
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AREA FORECAST DISCUSSION
NWS GRAY ME
956 AM EST SUN DEC 1 2013
.SYNOPSIS...
WEAK LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLIDE SOUTHEAST
ACROSS THE AREA THROUGH TONIGHT. A SECOND WEAK LOW WILL TRACK
NORTHEAST AND PASS JUST OFFSHORE TONIGHT AND EARLY MONDAY. THESE
TWO SYSTEMS WILL PRODUCE SOME OCCASIONAL LIGHT SNOW INTO TONIGHT,
WITH MIXING OR A CHANGEOVER TO LIGHT RAIN POSSIBLE NEAR THE COAST.
WEAK TROUGHING ALONG THE COAST KEEPS PRECIPITATION NEARBY ON
MONDAY. LOW PRESSURE TRAVELS UP THE ATLANTIC COASTLINE TUESDAY,
SPREADING MORE PRECIPITATION OVER THE REGION THROUGH WEDNESDAY
MORNING. RIDGING BUILDS IN BRIEFLY BEFORE A COLD FRONT CROSSES THE
REGION THURSDAY.
&&
.NEAR TERM /UNTIL 5 PM THIS AFTERNOON/...
945 AM...THE COASTAL FRONT IS SETTING UP SHOP JUST OFFSHORE THEN
EXTENDS INTO MY EASTERN ZONES AND TO THE WEST OF ROCKLAND. I LOWERED
MAXIMUM TEMPERATURES A BIT IN MANY AREAS AS A RESULT. MODELS HAVE A
WEAK LOW TRAVELING NORTHEAST ALONG THIS BOUNDARY LATE TODAY AND
TONIGHT WITH HEAVIEST QPF FOR MID COAST REGION. WHILE AREAS NEAR
ROCKLAND MAY STAY ON THE WARM SIDE OF THE BOUNDARY AND SEE MAINLY
RAIN...IMMEDIATELY ON THE OTHER SIDE OF THE BOUNDARY SEVERAL
INCHES OF WET SNOW WILL FALL. I MADE ADJUSTMENTS TO 1ST PERIOD
GRIDS BASED ON THE MESONET AND TO REFLECT THE LATEST RADAR TRENDS
FOR BANDED PRECIPITATION. ON THE WATERS...WINDS AND SEAS TOUCHED
MARGINAL SMALL CRAFT ALONG THE BOUNDARY AND I`VE ISSUED AN SCA FOR
AREA OUTSIDE THE BAY FOR THE NEXT FEW HOURS. HRR WINDS WERE USED
TO TAILOR WIND GRIDS TO BETTER REFLECT THE COASTAL BOUNDARY.
PREV DISC...
640 AM...FORECAST THINKING GENERALLY ON TRACK. ACTUALLY MODELS
SEEM TO HAVE A DECENT HANDLE ON THE CURRENT EVENTS...WITH 06Z
NAM12 HANDLING THE LARGER SCALE WELL...CAPTURING THE SHRA DEVELOPING
OVER CT AND LONG ISLAND SOUND...AND THE RUC PICKING UP ON THE VERY
LIGHT SHSN /MAYBE SNIZZLE?/...OVER THE COASTAL PLAIN....WHERE THIS
SHOULD REMAIN SPOTTY THRU THE MORNING...AND CHANGE TO RA ON THE
COAST....BEFORE STEADIER PRECIP DEVELOPS THIS AFTERNOON. ANY CHANGES
TO THE FORECAST BASED ON CURRENT OBS HAVE BEEN MINOR AND ONLY RUN
THRU APPROX THE FIRST 6 HOURS OF THE FORECAST.
PREVIOUSLY...A SOMEWHAT TRICKY FORECAST TODAY INTO TONIGHT AS
VERY WEAK IMPULSES ALOFT...ONE TO OUR S AND ONE TO OUR N PASS
THROUGH WITHIN LESS THAN 12 HOURS OF EACH OTHER...ALTHOUGH EITHER
ONE IS VERY DYNAMIC. THE FIST ONE...IN THE SRN STREAM ACTUALLY
MOVES THROUGH IN THE NEXT FEW HOURS...WITH VERY WEAK SFC
REFLECTION...AND LIGHT PRECIP ASSOCIATED WITH WEAK WAA AHEAD OF IT
MOVED THRU OVERNIGHT. THE SECOND APPROACHES TODAY...AND GENERATES A
BIT MORE LOW TO MID-LVL WAA...WHICH WORKS WITH COASTAL FRONT...AND
GENERATES AN INVERTED SFC TROUGH. THIS PRODUCES SOME MORE ORGANIZED
FORCING ALONG AND JUST INLAND FROM THE COAST THIS AFTERNOON. WHILE
SOME LIGHT PRECIP IS POSSIBLE THIS MORNING...THE BETTER CHC WILL BE
THIS AFTERNOON INTO THE EVENING AS THE FORCING INCREASES. THIS
PRECIP WILL NOT MOVE IN FROM THE WEST SO MUCH AS IT DEVELOPS ALONG
THE COASTAL FRONT.
COASTAL AREAS...FIRST TIER OF COASTAL ZONES...ARE LIKELY TO START
AS RAIN OR SHIFT TO RAIN QUICKLY...BUT P-TYPE WILL BE SOMEWHAT OF
AN ISSUE FOR INLAND AREAS OF THE COASTAL PLAIN. THE COASTAL FRONT
WILL MOVE INLAND TODAY...SO SOME AREAS THAT SEE SOME LIGHT SNOW
EARLY WILL CHANGE TO RAIN THIS AFTERNOON...AND MOST PLACES IN NH
AND FAR WRN ME WILL BE LIMITED TO ABOUT A TENTH OF TOTAL QPF
ANYWAY...WHICH WILL LIMIT TO SNOWFALL TO AN INCH OR SO...MAYBE A
LITTLE MORE IN THE MTNS...WHERE RATIOS WILL BE HIGHER.
MODELS SEEM TO BE FAIR AGREEMENT WHERE HIGHEST QPF WILL
OCCUR...MAINLY E OF KPWM-KLEW...WHERE QPF TODAY INTO THIS EVE
LOOKS BE 0.3-0.4 INCHES. SO INLAND AREAS OF THE KENNEBEC AND
PENOBSCOT VLYS ARE WHERE THE MOST SNOW IS EXPECTED TO FALL. HERE
WE ARE LOOKING AT GENERALLY ONE TO THREE INCHES...WITH SOME 4 INCH
AMOUNTS POSSIBLE. THE BULLSEYE FOR THE HIGHEST SNOWFALL LOOKS TO
BE IN THE SKOWHEGAN-WATERVILLE-UNITY VICINITY.
HOWEVER...MODELS ARE FAR FROM PERFECT WHEN IT COMES TO INVERTED
TROUGHS...AND THIS COULD END UP SHIFTING A BIT.
&&
.SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 PM MONDAY/...
AS THE WEAK
500MB TROUGH ACTUALLY DEEPENS SLIGHTLY JUST TO OUR E LATE
TONIGHT...EXPECTING SOME WEAK RIDGING ALOFT TO DEVELOP BEHIND IT FOR
MONDAY. WILL LOSE A FEW DEGREES AS WINDS SHIFT N ON THE BACK END OF
THE TROUGH...ESPECIALLY IN THE N...AND THIS COULD TURN BACK TO LIGHT
SN BEFORE IT ENDS IN ERN ZONES. SO PRECIP IS EXPECTED TO WIND DOWN
LATE TONIGHT...WITH A BREAK EXPECTED ON MONDAY...ALTHOUGH WE
PROBABLY WILL NOT SEE MUCH SUN ON MONDAY...AS STAGNANT LOW LVL FLOW
LINGERS. HIGHS SHOULD CLIMB BACK INTO THE MID 30S TO AROUND 40 AGAIN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS WAS THE CASE THE LAST COUPLE OF NIGHTS...NWP CONTINUES TO
INDICATE SRN STREAM S/WV TROF WILL OUTPACE ITS NRN STREAM
COUNTERPART. THE RESULT IS LOW PRES DEVELOPING OFF THE SOUTHEAST
COASTLINE...AND HEADING OUT TO SEA WITH A LATE CAPTURE THAT SWINGS
IT TOWARDS THE CANADIAN MARITIMES.
CONSENSUS IS THAT PCPN WILL ONLY BRUSH THE COAST...WITH THE
MIDCOAST PERHAPS SEEING A LITTLE LONGER DURATION AS LOW PRES CUTS
ACROSS BAROCLINIC ZONE. MODEL GUIDANCE HAS A VERY SHARP NRN EDGE
TO THE SATURATED SNOW GROWTH ZONE...SO WE WILL BE TREADING A VERY
FINE LINE OF SN OR NO SN HEADING INTO TUE. IN FACT...SFC TEMPS
WILL BE MARGINAL ENOUGH THAT SOME RNFL IS POSSIBLE NEAR THE COAST.
AS UPPER TROF CROSSES THE AREA THERE SHOULD BE ENOUGH FORCING AND
RESIDUAL MOISTURE TO BRING SCT SHSN TO MUCH OF THE AREA BEFORE
HIGH PRES BUILDS IN AND ENDS PCPN. THAT RIDGING WILL BE SHORT
LIVED THOUGH...AS NEXT LOW PRES DEVELOPS AND LIFTS INTO CANADA.
THIS WILL DRIVE A COLD FNT TOWARDS NEW ENGLAND. AFTER INITIAL
BURST OF WAA AHEAD OF THE LOW PRES...COLD WILL SLOWLY OOZE INTO
THE AREA AS FNT BECOMES ALIGNED WITH FLOW ALOFT. AS LONG AS
BOUNDARY REMAINS IN THE AREA IT WILL BE HARD TO RULE OUT
OVERRUNNING PCPN IN BROAD SWLY WAA REGIME.
LATE IN THE WEEK STRONG HIGH PRES WILL BUILD INTO THE
REGION...BEFORE WRN TROF EJECTS NEWD. GIVEN LOCATION OF HIGH
PRES...IT WOULD NOT BE SURPRISING TO SEE NWP TREND COOLER WITH
TIME...THOUGH THERE ARE SEVERAL DAYS BEFORE ANY DETAILS WILL
BECOME MORE CLEAR.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...SHOULD SEE ALL TERMINALS GET A PERIOD OF MVFR TO IFR
TODAY WITH SHSN INLAND...AND SHRA ON THE COAST. A STEADIER RA IS
EXPECTED AT KRKD...AND A STEADY MIX OF RASN AT KAUG. CONDITIONS
WILL IMPROVE LATE TONIGHT TO VFR FROM KPWM WWD...AND EVENTUALLY AT
KAUG/KRKD ON MONDAY.
LONG TERM...AREAS OF MVFR OR LOWER CONDITIONS WILL BE POSSIBLE TUE
INTO WED AS OCEAN LOW PRES PASS OUT TO SEA. COASTAL TERMINALS WILL
SEE LOWER CIGS AS WELL AS POSSIBLE SHSN LIMITING VSBYS. PASSAGE OF
UPPER TROF MAY ALSO RESULT IN SOME MTNS SHWRS INVOF OF KHIE.
&&
.MARINE...
SHORT TERM...SOUTHERLY SURGE IN WINDS OCCURRING ATTM AND COULD SEE
A FEW GUSTS UP TO 25 KT THRU SUNRISE. OTHERWISE...QUIET WEATHER
WITH VSBY RESTRICTIONS EXPECTED LATER TONIGHT THROUGH SUNDAY NIGHT
IN DEVELOPING RAIN AND SNOW.
LONG TERM...STILL SOME UNCERTAINTY REGARDING THE TRACK OF COASTAL
LOW PRES MIDWEEK. HOWEVER CONFIDENCE IS GROWING THAT SEAS WILL
BUILD TO AT OR ABOVE 5 FT FOR TUE AND WED. WINDS MORE THAN LIKELY
SHOULD REMAIN AT OR BELOW 25 KTS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR ANZ150-
152-154.
&&
$$
SCHWIBS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
915 AM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO CROSS THE STATE TODAY AND REDEVELOP IN
THE GULF OF MAINE TONIGHT, PASSING WELL E OF THE REGION ON MONDAY.
ANOTHER LOW MAY AFFECT THE REGION FROM THE SOUTH TOWARD THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...NO SIGNIFICANT CHANGES WERE NEEDED WITH THIS
UPDATE. MADE SOME SLIGHT ADJUSTMENTS TO POPS THROUGH THIS
AFTERNOON TO MATCH CURRENT RADAR TRENDS AND THE LATEST GUIDANCE.
ALSO BUMPED UP TEMPS JUST A BIT ALONG THE COAST, WHERE IT`S
ALREADY IN THE MID 30S. OTHERWISE, NO OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...WEAK LOW PRES MOVING ACROSS THE EASTERN
GREAT LAKES IS FCST TO MOVE ACROSS SOUTHERN NEW ENGLAND THIS
AFTERNOON AND THEN INTO THE GULF OF MAINE. THE CONCERN IS WHERE
TO DRAW THE RAIN/SNOW LINE AS WAA MAKES ITS WAY TO THE BLYR.
TEMPERATURES ARE FCST TO REACH INTO THE UPPER 20S TO AROUND 30
ACROSS THE NORTHERN 1/2 OF THE CWA WHILE LOW TO MID 30S ARE
EXPECTED FOR CENTRAL AND DOWNEAST AREAS. AN INVERTED TROF
EXTENDING FROM THE LOW COMBINED W/SOME FRONTOGENETICAL FORCING AT
1000-700MB WILL LEAD TO A REFORMATION OF PRECIP AND AN ENHANCEMENT
OF THE PRECIP. USING THE BUFKIT PROFILES AND SOUNDINGS, THINKING
HERE IS THAT SNOW WILL REDEVELOP ACROSS PORTION OF NORTHEAST MAINE
W/THE HEAVIEST AXIS ACROSS THE HOULTON AND DANFORTH REGION W/LESS
SNOW NORTH AND WEST. S OF OF THE HOULTON-DANFORTH LINE,
TEMPERATURES WILL WARM INTO THE MID 30S TO ALLOW FOR SNOW TO MIX
WITH AND CHANGEOVER TO RAIN. THIS IN TURN WILL CUT DOWN ON
SNOWFALL LATER THIS AFTERNOON INTO TONIGHT. DECISION WAS TO GO
AHEAD AND ADD NORTHERN PENOBSCOT AND SE AROOSTOOK COUNTY IN THE
WINTER WEATHER ADVISORY THROUGH MONDAY MORNING DUE TO ENHANCED
FRONTOGENTICAL FORCING LEADING TO HEAVY SNOW BURSTS. LATEST SNOW
TOTAL MAP SHOWS A GENERAL 4-8 INCHES IN THE ADVISORY AREA W/1-4
INCHES N AND W. THE COAST AND EXTREME EASTERN WASHINGTON COUNTY
FROM MEDDYBEMPS TO EASTPORT WILL SEE 0.30 TO 0.70 INCHES OF
RAINFALL AFTER SOME INITIAL SNOWFALL.
SNOW WILL CONTINUE INTO TONIGHT ACROSS THE NORTHEASTERN SECTION OF
MAINE INCLUDING CARIBOU-PRESQUE ISLE DOWN THROUGH DANFORTH. WEST
OF THIS AREA, LITTLE OR NO SNOW AND RAIN/SNOW S OF THIS AREA
W/RAIN FOR THE COAST AS THE WARM AIR IS FCST TO STAY IN. TEMPERATURES
WILL DROP BACK INTO THE UPPER TEENS AND LOWER 20S NORTH AND WEST
AND MID TO UPPER 20S FOR CENTRAL AREAS. LOW 30S FOR THE DOWNEAST
REGION INCLUDING THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
SNOW WILL CONTINUE TO WIND DOWN EARLY MONDAY AS THE INVERTED TROF
EXTENDING FROM THE CANADIAN MARITIMES THROUGH DOWNEAST MAINE MOVES
OFF TO THE NORTHEAST. THERE MAY STILL BE SOME LINGERING LIGHT SNOW
OR SNOW SHOWERS PARTICULARLY ACROSS EASTERN AREAS OTHERWISE EXPECT
MOSTLY CLOUDY SKIES ACROSS THE REGION. MONDAY NIGHT WILL BE MOSTLY
CLOUDY BUT DRY AS WEAK HIGH PRESSURE RIDGES DOWN FROM THE NORTH.
ATTENTION THEN TURNS TO ANOTHER LOW PRESSURE SYSTEM THAT WILL BE
MOVING NORTHEAST ACROSS THE WESTERN ATLANTIC. THIS SYSTEM MAY BRINGS
SOME PRECIPITATION TO THE REGION LATER TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS SEEM TO BE COMING INTO BETTER AGREEMENT FOR THE NEXT SYSTEM
TUESDAY NIGHT AND WEDNESDAY. STILL SOME MODEL DIFFERENCES BUT THE
CONSENSUS SOLUTION IS FOR THE LOW TO TRACK FAR ENOUGH EAST THAT ANY
IMPACTS IN OUR REGION WOULD BE ACROSS DOWNEAST/EASTERN MAINE.
A WEAK BOUNDARY WILL CROSS THE REGION BY LATE WEEK WITH SOME
SNOW/RAIN SHOWERS POSSIBLE. AGAIN...WILL STICK CLOSE TO THE
SUPERBLEND.
HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION BY SATURDAY.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MVFR W/PERIODS OF VFR THIS MORNING DROPPING TO MVFR AND
EVEN IFR LATER THIS MORNING ON INTO TONIGHT. SNOW ACROSS THE NORTHERN
TERMINALS W/SNOW TO RAIN FOR KBGR TO KBHB.
SHORT TERM: MVFR CONDS ARE POSSIBLE EARLY MONDAY THEN VFR CONDS
EXPECTED MONDAY NIGHT INTO TUESDAY. MVFR CONDS ARE POSSIBLE IN
SOME LIGHT PRECIP LATE TUESDAY AND INTO EARLY WEDNESDAY. VFR ON
THURSDAY.
&&
.MARINE...
NEAR TERM: DECIDED TO GO W/A SCA THROUGH LATE MORNING. WINDS
GUSTING TO 25 KTS AS LLVL JET OF 30 KT MOVES ACROSS THE WATERS.
THE GFS AND NAM AS WELL AS THE LATEST RAP MODEL PICK UP ON THIS
FEATURE. WINDS ARE FCST TO DROP OFF THIS AFTERNOON AS THE LLVL JET
SHIFTS TO THE E. SEAS ARE AT 5FT AND COULD TIP 6 FT ESPECIALLY AT
44027(JONESPORT) THIS MORNING. SEAS WILL GRADUALLY SUBSIDE TONIGHT
BELOW 4 FT.
SHORT TERM: WINDS/SEAS WILL BE BELOW SCA LEVELS MON AND MON NIGHT.
WIND/SEAS MAY INCREASE TO SCA LEVELS TUE/TUE NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MEZ005-006-
011-016-017-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR
ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS GRAY ME
817 AM EST SUN DEC 1 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK SOUTHEAST OUT OF QUEBEC AND ACROSS
THE AREA TONIGHT...PRODUCING SOME LIGHT SNOW INLAND AND A MIX OF
SNOW AND RAIN NEAR THE COAST. WEAK TROUGHING ALONG THE COAST KEEPS
PRECIPITATION NEARBY ON MONDAY. LOW PRESSURE TRAVELS UP THE
ATLANTIC COASTLINE TUESDAY...SPREADING MORE PRECIPITATION OVER THE
REGION THROUGH WEDNESDAY MORNING. RIDGING BUILDS IN BRIEFLY BEFORE
A COLD FRONT CROSSES THE REGION THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
640 AM...FORECAST THINKING GENERALLY ON TRACK. ACTUALLY MODELS
SEEM TO HAVE A DECENT HANDLE ON THE CURRENT EVENTS...WITH 06Z
NAM12 HANDLING THE LARGER SCALE WELL...CAPTURING THE SHRA DEVELOPING
OVER CT AND LONG ISLAND SOUND...AND THE RUC PICKING UP ON THE VERY
LIGHT SHSN /MAYBE SNIZZLE?/...OVER THE COASTAL PLAIN....WHERE THIS
SHOULD REMAIN SPOTTY THRU THE MORNING...AND CHANGE TO RA ON THE
COAST....BEFORE STEADIER PRECIP DEVELOPS THIS AFTERNOON. ANY CHANGES
TO THE FORECAST BASED ON CURRENT OBS HAVE BEEN MINOR AND ONLY RUN
THRU APPROX THE FIRST 6 HOURS OF THE FORECAST.
PREVIOUSLY...A SOMEWHAT TRICKY FORECAST TODAY INTO TONIGHT AS
VERY WEAK IMPULSES ALOFT...ONE TO OUR S AND ONE TO OUR N PASS
THROUGH WITHIN LESS THAN 12 HOURS OF EACH OTHER...ALTHOUGH EITHER
ONE IS VERY DYNAMIC. THE FIST ONE...IN THE SRN STREAM ACTUALLY
MOVES THROUGH IN THE NEXT FEW HOURS...WITH VERY WEAK SFC
REFLECTION...AND LIGHT PRECIP ASSOCIATED WITH WEAK WAA AHEAD OF IT
MOVED THRU OVERNIGHT. THE SECOND APPROACHES TODAY...AND GENERATES A
BIT MORE LOW TO MID-LVL WAA...WHICH WORKS WITH COASTAL FRONT...AND
GENERATES AN INVERTED SFC TROUGH. THIS PRODUCES SOME MORE ORGANIZED
FORCING ALONG AND JUST INLAND FROM THE COAST THIS AFTERNOON. WHILE
SOME LIGHT PRECIP IS POSSIBLE THIS MORNING...THE BETTER CHC WILL BE
THIS AFTERNOON INTO THE EVENING AS THE FORCING INCREASES. THIS
PRECIP WILL NOT MOVE IN FROM THE WEST SO MUCH AS IT DEVELOPS ALONG
THE COASTAL FRONT.
COASTAL AREAS...FIRST TIER OF COASTAL ZONES...ARE LIKELY TO START
AS RAIN OR SHIFT TO RAIN QUICKLY...BUT P-TYPE WILL BE SOMEWHAT OF
AN ISSUE FOR INLAND AREAS OF THE COASTAL PLAIN. THE COASTAL FRONT
WILL MOVE INLAND TODAY...SO SOME AREAS THAT SEE SOME LIGHT SNOW
EARLY WILL CHANGE TO RAIN THIS AFTERNOON...AND MOST PLACES IN NH
AND FAR WRN ME WILL BE LIMITED TO ABOUT A TENTH OF TOTAL QPF
ANYWAY...WHICH WILL LIMIT TO SNOWFALL TO AN INCH OR SO...MAYBE A
LITTLE MORE IN THE MTNS...WHERE RATIOS WILL BE HIGHER.
MODELS SEEM TO BE FAIR AGREEMENT WHERE HIGHEST QPF WILL
OCCUR...MAINLY E OF KPWM-KLEW...WHERE QPF TODAY INTO THIS EVE
LOOKS BE 0.3-0.4 INCHES. SO INLAND AREAS OF THE KENNEBEC AND
PENOBSCOT VLYS ARE WHERE THE MOST SNOW IS EXPECTED TO FALL. HERE
WE ARE LOOKING AT GENERALLY ONE TO THREE INCHES...WITH SOME 4 INCH
AMOUNTS POSSIBLE. THE BULLSEYE FOR THE HIGHEST SNOWFALL LOOKS TO
BE IN THE SKOWHEGAN-WATERVILLE-UNITY VICINITY.
HOWEVER...MODELS ARE FAR FROM PERFECT WHEN IT COMES TO INVERTED
TROUGHS...AND THIS COULD END UP SHIFTING A BIT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...AS THE WEAK
500MB TROUGH ACTUALLY DEEPENS SLIGHTLY JUST TO OUR E LATE
TONIGHT...EXPECTING SOME WEAK RIDGING ALOFT TO DEVELOP BEHIND IT FOR
MONDAY. WILL LOSE A FEW DEGREES AS WINDS SHIFT N ON THE BACK END OF
THE TROUGH...ESPECIALLY IN THE N...AND THIS COULD TURN BACK TO LIGHT
SN BEFORE IT ENDS IN ERN ZONES. SO PRECIP IS EXPECTED TO WIND DOWN
LATE TONIGHT...WITH A BREAK EXPECTED ON MONDAY...ALTHOUGH WE
PROBABLY WILL NOT SEE MUCH SUN ON MONDAY...AS STAGNANT LOW LVL FLOW
LINGERS. HIGHS SHOULD CLIMB BACK INTO THE MID 30S TO AROUND 40 AGAIN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS WAS THE CASE THE LAST COUPLE OF NIGHTS...NWP CONTINUES TO
INDICATE SRN STREAM S/WV TROF WILL OUTPACE ITS NRN STREAM
COUNTERPART. THE RESULT IS LOW PRES DEVELOPING OFF THE SOUTHEAST
COASTLINE...AND HEADING OUT TO SEA WITH A LATE CAPTURE THAT SWINGS
IT TOWARDS THE CANADIAN MARITIMES.
CONSENSUS IS THAT PCPN WILL ONLY BRUSH THE COAST...WITH THE
MIDCOAST PERHAPS SEEING A LITTLE LONGER DURATION AS LOW PRES CUTS
ACROSS BAROCLINIC ZONE. MODEL GUIDANCE HAS A VERY SHARP NRN EDGE
TO THE SATURATED SNOW GROWTH ZONE...SO WE WILL BE TREADING A VERY
FINE LINE OF SN OR NO SN HEADING INTO TUE. IN FACT...SFC TEMPS
WILL BE MARGINAL ENOUGH THAT SOME RNFL IS POSSIBLE NEAR THE COAST.
AS UPPER TROF CROSSES THE AREA THERE SHOULD BE ENOUGH FORCING AND
RESIDUAL MOISTURE TO BRING SCT SHSN TO MUCH OF THE AREA BEFORE
HIGH PRES BUILDS IN AND ENDS PCPN. THAT RIDGING WILL BE SHORT
LIVED THOUGH...AS NEXT LOW PRES DEVELOPS AND LIFTS INTO CANADA.
THIS WILL DRIVE A COLD FNT TOWARDS NEW ENGLAND. AFTER INITIAL
BURST OF WAA AHEAD OF THE LOW PRES...COLD WILL SLOWLY OOZE INTO
THE AREA AS FNT BECOMES ALIGNED WITH FLOW ALOFT. AS LONG AS
BOUNDARY REMAINS IN THE AREA IT WILL BE HARD TO RULE OUT
OVERRUNNING PCPN IN BROAD SWLY WAA REGIME.
LATE IN THE WEEK STRONG HIGH PRES WILL BUILD INTO THE
REGION...BEFORE WRN TROF EJECTS NEWD. GIVEN LOCATION OF HIGH
PRES...IT WOULD NOT BE SURPRISING TO SEE NWP TREND COOLER WITH
TIME...THOUGH THERE ARE SEVERAL DAYS BEFORE ANY DETAILS WILL
BECOME MORE CLEAR.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...SHOULD SEE ALL TERMINALS GET A PERIOD OF MVFR TO IFR
TODAY WITH SHSN INLAND...AND SHRA ON THE COAST. A STEADIER RA IS
EXPECTED AT KRKD...AND A STEADY MIX OF RASN AT KAUG. CONDITIONS
WILL IMPROVE LATE TONIGHT TO VFR FROM KPWM WWD...AND EVENTUALLY AT
KAUG/KRKD ON MONDAY.
LONG TERM...AREAS OF MVFR OR LOWER CONDITIONS WILL BE POSSIBLE TUE
INTO WED AS OCEAN LOW PRES PASS OUT TO SEA. COASTAL TERMINALS WILL
SEE LOWER CIGS AS WELL AS POSSIBLE SHSN LIMITING VSBYS. PASSAGE OF
UPPER TROF MAY ALSO RESULT IN SOME MTNS SHWRS INVOF OF KHIE.
&&
.MARINE...
SHORT TERM...SOUTHERLY SURGE IN WINDS OCCURRING ATTM AND COULD SEE
A FEW GUSTS UP TO 25 KT THRU SUNRISE. OTHERWISE...QUIET WEATHER
WITH VSBY RESTRICTIONS EXPECTED LATER TONIGHT THROUGH SUNDAY NIGHT
IN DEVELOPING RAIN AND SNOW.
LONG TERM...STILL SOME UNCERTAINTY REGARDING THE TRACK OF COASTAL
LOW PRES MIDWEEK. HOWEVER CONFIDENCE IS GROWING THAT SEAS WILL
BUILD TO AT OR ABOVE 5 FT FOR TUE AND WED. WINDS MORE THAN LIKELY
SHOULD REMAIN AT OR BELOW 25 KTS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS GRAY ME
644 AM EST SUN DEC 1 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK SOUTHEAST OUT OF QUEBEC AND ACROSS
THE AREA TONIGHT...PRODUCING SOME LIGHT SNOW INLAND AND A MIX OF
SNOW AND RAIN NEAR THE COAST. WEAK TROUGHING ALONG THE COAST KEEPS
PRECIPITATION NEARBY ON MONDAY. LOW PRESSURE TRAVELS UP THE
ATLANTIC COASTLINE TUESDAY...SPREADING MORE PRECIPITATION OVER THE
REGION THROUGH WEDNESDAY MORNING. RIDGING BUILDS IN BRIEFLY BEFORE
A COLD FRONT CROSSES THE REGION THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
640 AM...FORECAST THINKING GENERALLY ON TRACK. ACTUALLY MODELS
SEEM TO HAVE A DECENT HANDLE ON THE CURRENT EVENTS...WITH 06Z
NAM12 HANDLING THE LARGER SCALE WELL...CAPTURING THE SHRA
DEVELOPING OVER CT AND LI SOUND...AND THE RUC PICKING UP ON THE
VERY LIGHT SHSN /MAYBE SNIZZLE?/...OVER THE COASTAL PLAIN....WHERE
THIS SHOULD REMAIN SPOTTY THRU THE MORNING...AND CHANGE TO RA ON
THE COAST....BEFORE STEADIER PRECIP DEVELOPS THIS AFTERNOON. ANY
CHANGES TO THE FORECAST BASED ON CURRENT OBS HAVE BEEN MINOR AND
ONLY RUN THRU APPROX THE FIRST 6 HOURS OF THE FORECAST.
PREVIOUSLY...A SOMEWHAT TRICKY FORECAST TODAY INTO TONIGHT AS
VERY WEAK IMPULSES ALOFT...ONE TO OUR S AND ONE TO OUR N PASS
THROUGH WITHIN LESS THAN 12 HOURS OF EACH OTHER...ALTHOUGH EITHER
ONE IS VERY DYNAMIC. THE FIST ONE...IN THE SRN STREAM ACTUALLY
MOVES THROUGH IN THE NEXT FEW HOURS...WITH VERY WEAK SFC
REFLECTION...AND LIGHT PRECIP ASSOCIATED WITH WEAK WAA AHEAD OF IT
MOVED THRU OVERNIGHT. THE SECOND APPROACHES TODAY...AND GENERATES
A BIT MORE LOW TO MID- LVL WAA...WHICH WORKS WITH COASTAL
FRONT...AND GENERATES A AN INVERTED SFC TROUGH. THIS PRODUCES SOME
MORE ORGANIZED FORCING ALONG AND JUST INLAND FROM THE COAST THIS
AFTERNOON. WHILE SOME LIGHT PRECIP IS POSSIBLE THIS MORNING...THE
BETTER CHC WILL BE THIS AFTERNOON INTO THE EVENING AS THE FORCING
INCREASES. THIS PRECIP WILL NOT MOVE IN FROM THE WEST SO MUCH AS
IT DEVELOPS ALONG THE COASTAL FRONT.
COASTAL AREAS...FIRST TIER OF COASTAL ZONES...ARE LIKELY TO START
AS RAIN OR SHIFT TO RAIN QUICKLY...BUT P-TYPE WILL BE SOMEWHAT OF
AN ISSUE FOR INLAND AREAS OF THE COASTAL PLAIN. THE COASTAL FRONT
WILL MOVE INLAND TODAY...SO SOME AREAS THAT SEE SOME LIGHT SNOW
EARLY WILL CHANGE TO RAIN THIS AFTERNOON...AND MOST PLACES IN NH
AND FAR WRN ME WILL BE LIMITED TO ABOUT A TENTH OF TOTAL QPF
ANYWAY...WHICH WILL LIMIT TO SNOWFALL TO AN INCH OR SO...MAYBE A
LITTLE MORE IN THE MTNS...WHERE RATIOS WILL BE HIGHER.
MODELS SEEM TO BE FAIR AGREEMENT WHERE HIGHEST QPF WILL
OCCUR...MAINLY E OF KPWM-KLEW...WHERE QPF TODAY INTO THIS EVE
LOOKS BE 0.3-0.4 INCHES. SO INLAND AREAS OF THE KENNEBEC AND
PENOBSCOT VLYS ARE WHERE THE MOST SNOW IS EXPECTED TO FALL. HERE
WE ARE LOOKING AT GENERALLY ONE TO THREE INCHES...WITH SOME 4 INCH
AMOUNTS POSSIBLE. THE BULLSYEYE FOR THE HIGHEST SNOWFALL LOOKS TO
BE IN THE SKOWHEGAN-WATERVILLE-UNITY VICINITY.
HOWEVER...MODELS ARE FAR FROM PERFECT WHEN IT COMES TO INVERTED
TROUGHS...AND THIS COULD END UP SHIFTING A BIT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
AS THE WEAK 500MB TROUGH ACTUALLY DEEPENS SLIGHTLY JUST TOUR E
LATE TONIGHT...EXPECTING SOME WEAK RIDGING ALOFT TO DEVELOP BEHIND
IT FOR MONDAY. WILL LOSE A FEW DEGREES AS WINDS SHIFT N ON THE
BACK END OF THE TROUGH...ESPECIALLY IN THE N,...AND THIS COULD
TURN BACK TO LIGHT SN BEFORE IT ENDS IN ERN ZONES. SO PRECIP IS
EXPECTED TO WIND DOWN LATE TONIGHT...WITH A BREAK EXPECTED ON
MONDAY...ALTHOUGH WE PROBABLY WILL NOT SEE MUCH SUN ON MONDAY...AS
STAGNANT LOW LVL FLOW LINGERS. HIGHS SHOULD CLIMB BACK INTO THE
MID 30S TO AROUND 40 AGAIN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS WAS THE CAST THE LAST COUPLE OF NIGHTS...NWP CONTINUES TO
INDICATE SRN STREAM S/WV TROF WILL OUTPACE ITS NRN STREAM
COUNTERPART. THE RESULT IS LOW PRES DEVELOPING OFF THE SOUTHEAST
COASTLINE...AND HEADING OUT TO SEA WITH A LATE CAPTURE THAT SWINGS
IT TOWARDS THE CANADIAN MARITIMES.
CONSENSUS IS THAT PCPN WILL ONLY BRUSH THE COAST...WITH THE
MIDCOAST PERHAPS SEEING A LITTLE LONGER DURATION AS LOW PRES CUTS
ACROSS BAROCLINIC ZONE. MODEL GUIDANCE HAS A VERY SHARP NRN EDGE
TO THE SATURATED SNOW GROWTH ZONE...SO WE WILL BE TREADING A VERY
FINE LINE OF SN OR NO SN HEADING INTO TUE. IN FACT...SFC TEMPS
WILL BE MARGINAL ENOUGH THAT SOME RNFL IS POSSIBLE NEAR THE COAST.
AS UPPER TROF CROSSES THE AREA THERE SHOULD BE ENOUGH FORCING AND
RESIDUAL MOISTURE TO BRING SCT SHSN TO MUCH OF THE AREA BEFORE
HIGH PRES BUILDS IN AND ENDS PCPN. THAT RIDGING WILL BE SHORT
LIVED THOUGH...AS NEXT LOW PRES DEVELOPS AND LIFTS INTO CANADA.
THIS WILL DRIVE A COLD FNT TOWARDS NEW ENGLAND. AFTER INITIAL
BURST OF WAA AHEAD OF THE LOW PRES...COLD WILL SLOWLY OOZE INTO
THE AREA AS FNT BECOMES ALIGNED WITH FLOW ALOFT. AS LONG AS
BOUNDARY REMAINS IN THE AREA IT WILL BE HARD TO RULE OUT
OVERRUNNING PCPN IN BROAD SWLY WAA REGIME.
LATE IN THE WEEK STRONG HIGH PRES WILL BUILD INTO THE
REGION...BEFORE WRN TROF EJECTS NEWD. GIVEN LOCATION OF HIGH
PRES...IT WOULD NOT BE SURPRISING TO SEE NWP TREND COOLER WITH
TIME...THOUGH THERE ARE SEVERAL DAYS BEFORE ANY DETAILS WILL
BECOME MORE CLEAR.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...SHOULD SEE ALL TERMINALS GET A PREIOD OF MVFR TO IFR
TODAY WITH SHSN INLAND...AND SHRA ON THE COAST. A STEADIER RA IS
EXPECTED AT KRKD...AND A STEADY MIX OF RASN AT KAUG. CONDITIONS
WILL IMPROVE LATE TONIGHT TO VFR FROM KPWM WWD...AND EVENTUALLY AT
KAUG/KRKD ON MONDAY.
LONG TERM...AREAS OF MVFR OR LOWER CONDITIONS WILL BE POSSIBLE TUE
INTO WED AS OCEAN LOW PRES PASS OUT TO SEA. COASTAL TERMINALS WILL
SEE LOWER CIGS AS WELL AS POSSIBLE SHSN LIMITING VSBYS. PASSAGE OF
UPPER TROF MAY ALSO RESULT IN SOME MTNS SHWRS INVOF OF KHIE.
&&
.MARINE...
SHORT TERM...SOUTHERLY SURGE IN WINDS OCCURRING ATTM AND COULD SEE
A FEW GUSTS UP TO 25 KT THRU SUNRISE. OTHERWISE...QUIET WEATHER
WITH VSBY RESTRICTIONS EXPECTED LATER TONIGHT THROUGH SUNDAY NIGHT
IN DEVELOPING RAIN AND SNOW.
LONG TERM...STILL SOME UNCERTAINTY REGARDING THE TRACK OF COASTAL
LOW PRES MIDWEEK. HOWEVER CONFIDENCE IS GROWING THAT SEAS WILL
BUILD TO AT OR ABOVE 5 FT FOR TUE AND WED. WINDS MORE THAN LIKELY
SHOULD REMAIN AT OR BELOW 25 KTS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CARIBOU ME
630 AM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO CROSS THE STATE TODAY AND REDEVELOP IN
THE GULF OF MAINE TONIGHT, PASSING WELL E OF THE REGION ON MONDAY.
ANOTHER LOW MAY AFFECT THE REGION FROM THE SOUTH TOWARD THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: ADJUSTED THE PRECIP CHANCES LINING THEM UP W/THE RADAR
TRENDS AND OBS. KEPT THE HIGH PRECIP CHANCES(60-80%) TOWARD THE
EASTERN SIDE OF THE CWA AND SCALED THEM BACK FURTHER W THROUGH
THIS MORNING. REPORTS COMING SHOW AN INCH OR LESS OF ACCUMULATION
W/WHAT FELL OVERNIGHT
WEAK LOW PRES MOVING ACROSS THE EASTERN GREAT LAKES IS FCST TO
MOVE ACROSS SOUTHERN NEW ENGLAND THIS AFTERNOON AND THEN INTO THE
GULF OF MAINE. THE CONCERN IS WHERE TO DRAW THE RAIN/SNOW LINE AS
WAA MAKES ITS WAY TO THE BLYR. TEMPERATURES ARE FCST TO REACH INTO
THE UPPER 20S TO AROUND 30 ACROSS THE NORTHERN 1/2 OF THE CWA
WHILE LOW TO MID 30S ARE EXPECTED FOR CENTRAL AND DOWNEAST AREAS.
AN INVERTED TROF EXTENDING FROM THE LOW COMBINED W/SOME
FRONTOGENETICAL FORCING AT 1000-700MB WILL LEAD TO A REFORMATION
OF PRECIP AND AN ENHANCEMENT OF THE PRECIP. USING THE BUFKIT
PROFILES AND SOUNDINGS, THINKING HERE IS THAT SNOW WILL REDEVELOP
ACROSS PORTION OF NORTHEAST MAINE W/THE HEAVIEST AXIS ACROSS THE
HOULTON AND DANFORTH REGION W/LESS SNOW NORTH AND WEST. S OF OF
THE HOULTON-DANFORTH LINE, TEMPERATURES WILL WARM INTO THE MID 30S
TO ALLOW FOR SNOW TO MIX WITH AND CHANGEOVER TO RAIN. THIS IN TURN
WILL CUT DOWN ON SNOWFALL LATER THIS AFTERNOON INTO TONIGHT.
DECISION WAS TO GO AHEAD AND ADD NORTHERN PENOBSCOT AND SE
AROOSTOOK COUNTY IN THE WINTER WEATHER ADVISORY THROUGH MONDAY
MORNING DUE TO ENHANCED FRONTOGENTICAL FORCING LEADING TO HEAVY
SNOW BURSTS. LATEST SNOW TOTAL MAP SHOWS A GENERAL 4-8 INCHES IN
THE ADVISORY AREA W/1-4 INCHES N AND W. THE COAST AND EXTREME
EASTERN WASHINGTON COUNTY FROM MEDDYBEMPS TO EASTPORT WILL SEE
0.30 TO 0.70 INCHES OF RAINFALL AFTER SOME INITIAL SNOWFALL.
SNOW WILL CONTINUE INTO TONIGHT ACROSS THE NORTHEASTERN SECTION OF
MAINE INCLUDING CARIBOU-PRESQUE ISLE DOWN THROUGH DANFORTH. WEST
OF THIS AREA, LITTLE OR NO SNOW AND RAIN/SNOW S OF THIS AREA
W/RAIN FOR THE COAST AS THE WARM AIR IS FCST TO STAY IN. TEMPERATURES
WILL DROP BACK INTO THE UPPER TEENS AND LOWER 20S NORTH AND WEST
AND MID TO UPPER 20S FOR CENTRAL AREAS. LOW 30S FOR THE DOWNEAST
REGION INCLUDING THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
SNOW WILL CONTINUE TO WIND DOWN EARLY MONDAY AS THE INVERTED TROF
EXTENDING FROM THE CANADIAN MARITIMES THROUGH DOWNEAST MAINE MOVES
OFF TO THE NORTHEAST. THERE MAY STILL BE SOME LINGERING LIGHT SNOW
OR SNOW SHOWERS PARTICULARLY ACROSS EASTERN AREAS OTHERWISE EXPECT
MOSTLY CLOUDY SKIES ACROSS THE REGION. MONDAY NIGHT WILL BE MOSTLY
CLOUDY BUT DRY AS WEAK HIGH PRESSURE RIDGES DOWN FROM THE NORTH.
ATTENTION THEN TURNS TO ANOTHER LOW PRESSURE SYSTEM THAT WILL BE
MOVING NORTHEAST ACROSS THE WESTERN ATLANTIC. THIS SYSTEM MAY BRINGS
SOME PRECIPITATION TO THE REGION LATER TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS SEEM TO BE COMING INTO BETTER AGREEMENT FOR THE NEXT SYSTEM
TUESDAY NIGHT AND WEDNESDAY. STILL SOME MODEL DIFFERENCES BUT THE
CONSENSUS SOLUTION IS FOR THE LOW TO TRACK FAR ENOUGH EAST THAT ANY
IMPACTS IN OUR REGION WOULD BE ACROSS DOWNEAST/EASTERN MAINE.
A WEAK BOUNDARY WILL CROSS THE REGION BY LATE WEEK WITH SOME
SNOW/RAIN SHOWERS POSSIBLE. AGAIN...WILL STICK CLOSE TO THE
SUPERBLEND.
HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION BY SATURDAY.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MVFR W/PERIODS OF VFR THIS MORNING DROPPING TO MVFR AND
EVEN IFR LATER THIS MORNING ON INTO TONIGHT. SNOW ACROSS THE NORTHERN
TERMINALS W/SNOW TO RAIN FOR KBGR TO KBHB.
SHORT TERM: MVFR CONDS ARE POSSIBLE EARLY MONDAY THEN VFR CONDS
EXPECTED MONDAY NIGHT INTO TUESDAY. MVFR CONDS ARE POSSIBLE IN
SOME LIGHT PRECIP LATE TUESDAY AND INTO EARLY WEDNESDAY. VFR ON
THURSDAY.
&&
.MARINE...
NEAR TERM: DECIDED TO GO W/A SCA THROUGH LATE MORNING. WINDS
GUSTING TO 25 KTS AS LLVL JET OF 30 KT MOVES ACROSS THE WATERS.
THE GFS AND NAM AS WELL AS THE LATEST RAP MODEL PICK UP ON THIS
FEATURE. WINDS ARE FCST TO DROP OFF THIS AFTERNOON AS THE LLVL JET
SHIFTS TO THE E. SEAS ARE AT 5FT AND COULD TIP 6 FT ESPECIALLY AT
44027(JONESPORT) THIS MORNING. SEAS WILL GRADUALLY SUBSIDE TONIGHT
BELOW 4 FT.
SHORT TERM: WINDS/SEAS WILL BE BELOW SCA LEVELS MON AND MON NIGHT.
WIND/SEAS MAY INCREASE TO SCA LEVELS TUE/TUE NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MEZ005-006-
011-016-017-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
641 AM EST SUN DEC 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM EST SUN DEC 1 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR GRT LKS TO THE SW OF UPR TROF CENTERED OVER NRN QUEBEC. IN
THE WAKE OF DEPARTING SHRTWV MOVING THRU SW QUEBEC...A SHRTWV RDG IS
SLIDING SEWD THRU NW ONTARIO...SUPPORTING A SFC HI PRES OVER FAR NW
ONTARIO. CLOSER TO UPR MI...A LO PRES TROF IS APRNT NEAR THE LK SUP
SHORE OF UPR MI AND EXTENDING WNW IN THE MN ARROWHEAD. THIS TROF HAS
BEEN THE FOCUS FOR SOME BANDS OF HIER REFLECTIVITY SHOWN ON THE MQT
88D REFLECTIVITY WITH UPSLOPE N WINDS NEAR LK SUP. SINCE H85 TEMPS
ARE ONLY -7 TO -8C AND THE ACCOMPANYING MSTR IS RELATIVELY SHALLOW
AS DIAGNOSED FM THE MQT 88D VWP AS WELL AS THE 00Z INL RAOB...WHICH
SHOWS INVRN BASE NEAR H85 UNDER VERY DRY MID LVLS AHEAD OF APRCHG
SHRTWV RDG...ASSOCIATED PCPN HAS BEEN A MIX OF -SHSN AND SOME -FZDZ.
THE 00Z YPL RAOB SHOWS SHALLOW MSTR AS WELL BLO AN INVRN NEAR
H925...SO PLENTY OF LO CLDS EXTEND WELL N INTO ONTARIO. THE AIR IS
MUCH COLDER THERE WITH SFC TEMPS IN THE TEENS...SO SPOTTY LGT PCPN
IS IN THE FORM OF SN.
MAIN FCST CONCERN IN THE SHORT TERM IS THE POTENTIAL FOR SOME LGT
-SN AND -FZDZ.
TODAY...WITH APRCH OF SHRTWV RDG NOW IN NW ONTARIO...LARGER SCALE
QVECTOR DVGC/MID LVL DRYING IS FCST TO SLOWLY WEAKEN...BUT NOT
ELIMINATE ALTOGETHER...THE SFC TROF NOW OVER LK SUP AND INHIBIT ANY
LARGER SCALE PCPN. SFC HI PRES NOW OVER FAR NW ONTARIO IS PROGGED TO
DRIFT ONLY SLOWLY SE ACRS NRN ONTARIO...WITH THE CWA DOMINATED BY
WEAKENING AND SLOWLY VEERING LLVL NE FLOW. WL CONT TO CARRY SOME CHC
POPS NEAR LK SUP IN AREA THAT WL EXPERIENCE AN UPSLOPE WIND
COMPONENT NEAR LINGERING LO PRES TROF OVER THE NCENTRAL. WHETHER
THIS PCPN IS ALL -SN OR REMAINS MIXED WITH SOME -FZDZ IS THE PRIMARY
CONCERN. MODELS REMAIN INCONSISTNET ON FCST H85 TEMPS AND MSTR
DEPTH. FCST H85 TEMPS ARE FCST TO FALL TO ARND -9C BY THE 00Z
NAM/LOCAL WRF-ARW TO -11C BY THE GFS. GIVEN THE WEAKENING WINDS THAT
WL LIMIT LLVL CAD AND EXPECTED NEGATIVE DYNAMICS AS WELL AS UPSTREAM
RAOBS...PREFER THE SOMEWHAT WARMER H85 TEMPS AND SHALLOWER MSTR
PROFILE/LOWER INVRN BASE SHOWN BY THE 00Z LOCAL WRF-ARW MODEL. THIS
MODEL SHOWS THE UPSLOPE UVV AND INVRN BASE REMAINING NR 5K FT AGL
AND BLO THE DGZ... SO WL RETAIN A MIX OF -SN/-FZDZ THRU THE DAY.
MARGINAL H85 TEMPS RELATIVE TO LK WATER TEMP ARND 4C WL LIMIT ANY SN
ACCUM. WITH PLENTY OF LO CLDS...TEMPS SHOULD REBOUND ONLY SLIGHTLY
THRU THE DAY.
TNGT...VERY LGT LLVL WINDS ARE PROGGED TO SLOWLY VEER TO THE E AND
SE AS THE CENTER OF SFC HI PRES SHIFTS INTO QUEBEC. SUSPECT
LINGERING LK EFFECT PCPN WL DRIFT INTO THE KEWEENAW AS THE FLOW
GRDLY SHIFTS TO THE ESE. IN THE ABSENCE OF ANY DYNAMIC SUPPORT...
EXPECT THE INVRN BASE TO REMAIN NEAR 5K FT. AS POINTED OUT BY THE
DAYSHIFT...LK VORTICES OFTEN DVLP WITH THE FCST LGT LLVL WINDS. BUT
MARGINAL H85 TEMPS ARND -9C WL LIMIT THE INTENSITY OF ANY SHSN THAT
WOULD ACCOMPANY THESE FEATURES...AND THE LGT WINDS WL INHIBIT
BANDING. SO ANY SN ACCUMS SHOULD REMAIN LGT. SINCE THE H85 TEMPS WL
REMAIN MARGINAL FOR LES AND UPSLOPE OMEGA WL REMAIN BLO THE
DGZ...INCLUDED A MENTION OF FZDZ. LINGERING LO CLDS WL LIMIT THE
DIURNAL TEMP FALL. BEST CHC FOR SOMEWHAT LOWER TEMPS WL BE OVER THE
E WITH A RELATIVELY UNMODIFIED/DOWNSLOPE E FLOW OFF ONTARIO THAT
MIGHT ALLOW FOR SOME BREAKS IN THE SC.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 430 AM EST SUN DEC 1 2013
MONDAY THROUGH TUESDAY MORNING...UPPER LEVEL 500MB TROUGHING IS
EXPECTED TO REMAIN IN PLACE ACROSS THE CWA THROUGH THIS TIME PERIOD
AS A WEAK INVERTED RIDGE WEDGES IN ACROSS THE AREA AT THE SURFACE. A
SLIGHTLY DRYER AIRMASS WILL ALSO LINGER THROUGH TUESDAY MORNING
WHICH CAN BE SEEN BY ANALYZING 1000-500MB RH. THE NEXT SURFACE LOW
CAN BE SEEN PUSHING ACROSS THE NORTHERN ROCKIES MONDAY NIGHT AND
EJECTING INTO THE NORTHERN OR CENTRAL PLAINS TUESDAY MORNING AS A
MUCH DEEPER UPPER LEVEL 500MB TROUGH BUILDS IN OVER THE WESTERN U.S.
THERE ARE STILL SOME MODEL DIFFERENCE HOWEVER WITH THE 00Z GFS/NAM
BEING A BIT FASTER AND STRONGER WITH THIS LOW. THE 00Z GFS/NAM
PLACE THE SURFACE LOW ALONG THE NORTH AND SOUTH DAKOTA BORDER BY 12Z
ON TUESDAY. THE 00Z EC/GEM ARE THE SLOWER OF THE SOLUTIONS KEEPING
THE LOW A BIT FARTHER SOUTH AND REMAINING OVER THE CENTRAL PLAINS
JUST A BIT EAST OF THE ROCKIES. EITHER WAY...BOTH SOLUTIONS KEEP THE
PRECIPITATION TO THE WEST OF THE AREA THROUGH THIS TIME PERIOD.
LIGHT EASTERLY WINDS THROUGH MONDAY NIGHT WILL SLOWLY BECOME
SOUTHEASTERLY BY TUESDAY. THIS ALONG WITH H850 TEMPS AROUND -8 TO
-10 C WILL HELP TO KEEP CONDITIONS CLOUDY WITH VERY LIGHT
PRECIPITATION POSSIBLE...MAINLY OVER THE KEWEENAW PENINSULA.
TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...THIS TIME PERIOD REMAINS
UNCERTAIN WHICH HAS BEEN THE CASE OVER THE PAST SEVERAL DAYS...WITH
POOR MODEL AGREEMENT EVEN AS THIS TIME PERIOD IS RAPIDLY
APPROACHING...HOWEVER...THE 00Z EC TENDS TO BE TRENDING A BIT CLOSER
TO THE NAM AND GFS SOLUTIONS. THE GFS/NAM SOLUTIONS BRING INCREASED
MOISTURE AND PRECIPITATION INTO THE CWA BY 18Z TUESDAY...WHILE THE
EC/CANADIAN KEEP THE SYSTEM CENTERED OVER NORTHEASTERN KS DURING
THAT TIME FRAME. THE 00Z GFS PLACES THE SURFACE LOW AND VERTICALLY
STACKED CLOSED UPPER LEVEL 500MB LOW OVER WESTERN WI AT 00Z WED
WHILE THE 00Z EC HAS THE MORE ELONGATED SURFACE LOW OVER CENTRAL
IOWA INTO CENTRAL PLAINS. BY 18Z WED THE 00Z RUN OF THE GFS PUSHES
THE LOW TO THE NORTHEAST OF LAKE SUPERIOR WHILE THE EC IS JUST
PLACING THE SURFACE LOW AND UPPER LEVEL ENERGY INTO THE WESTERN
PORTION OF WI. DEFINITELY EASY TO SEE THAT THERE ARE STILL
SIGNIFICANT DIFFERENCES BETWEEN THESE MODELS...HOWEVER...A BETTER
SIGNAL EXISTS SINCE THE EC IS TRENDING A BIT CLOSES TO THE FASTER
SOLUTIONS...THE BEST IDEA FOR THE TIME BEING WILL BE MORE OF A
MIDDLE OF THE ROAD APPROACH...WITH A SLIGHT LEAN TOWARD THE FASTER
SOLUTIONS. THIS WOULD FAVOR A LATE TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT TIME FRAME FOR THE MORE CONCENTRATED AREA OF PRECIPITATION.
SOUNDINGS FOR THIS TIME PERIOD INDICATE WARMER AIR LIFTING NORTHWARD
ON THE EAST SIDE OF THE LOW HELPING TO TRANSITION THE PRECIPITATION
OVER TO A RAIN SNOW MIXTURE FOR AT LEAST THE EASTERN HALF OF THE
UPPER PENINSULA AS A FAIRLY DEEP WARM LAYER BUILDS IN THROUGH MUCH
OF THE BOUNDARY LAYER. THE FAR WESTERN PORTION OF THE U.P. MAY END
UP SEEING MAINLY SNOW AS SHOWN BY ANALYZING BOTH THE EC AND GFS
PROFILES. IN ANY CASE THIS SYSTEM WILL BE CLOSELY WATCHED OVER THE
NEXT SEVERAL MODEL RUNS TO SEE IF BETTER UPPER AIR SAMPLING CAN
ENTERTAIN GREATER MODEL AGREEMENT.
THURSDAY THROUGH SATURDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME. EACH OF THE
MODELS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY 12Z
THURSDAY. AS THIS HAPPENS WINDS WILL SHIFT TO THE WEST ALLOWING LAKE
EFFECT SNOW TO DEVELOP IN AREAS FAVORED BY THAT PARTICULAR WIND
DIRECTION. THURSDAY THROUGH THURSDAY NIGHT THE LAKE EFFECT SNOW WILL
PROBABLY JUST BE STARTING ACROSS THE AREA...BUT SHOULD REMAIN LIGHT.
TRIED TO TREND THE LES CHANCES UPWARD FRIDAY THROUGH SATURDAY AS AN
UPPER LEVEL TROUGH/SHORTWAVE AND INCREASED MOISTURE SHIFTS INTO THE
AREA...ALLOWING FOR ENHANCED LIFT FOR LES TO DEVELOP. ITS STILL A
BIT TOO EARLY TO TELL FOR SURE ABOUT THE OVERALL SNOWFALL
TOTALS...BUT IT DOES LOOK LIKE FRIDAY INTO SATURDAY WILL BE SNOW FOR
WESTERLY WIND FAVORED AREAS OF THE UPPER PENINSULA. AS EARLIER SHIFT
STATED THE SNOW TO LIQUID RATIOS WILL LIKELY BE SLIGHTLY LOWER THAN
USUAL FOR LES AS THE DGZ IS FAIRLY SHALLOW AND FAIRLY LOW IN THE
ATMOSPHERE...WHICH TENDS TO INHIBIT THE MORE FAVORABLE GROWTH RATES
FOR SNOW. STAY TUNED THOUGH AS THIS LES EVENT GETS CLOSER TOWARD THE
WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 641 AM EST SUN DEC 1 2013
EXPECT MVFR CIGS TO PREDOMINATE AT ALL 3 TAF SITES THIS FCST PERIOD
WITH RELATIVELY SHALLOW MOIST LYR TRAPPED BLO SUBSIDENCE INVRN
ASSOCIATED WITH HI PRES OVER ONTARIO. THERE MAY ALSO BE SOME -SN AND
PERHAPS SOME -FZDZ MAINLY THIS MRNG AT IWD AND SAW IN THE PRESENCE
OF AN UPSLOPE N-NE WIND OFF LK SUP ON THE SRN FLANK OF THE HI TO THE
N. BUT AS THE WIND DIMINISHES AND SLOWLY VEERS TO A MORE ESE
DIRECTION BY THIS EVNG...THE PCPN SHOULD DIMINISH AT THESE LOCATIONS
AND PERHAPS SHIFT INTO CMX. DOWNSLOPE NATURE OF THIS FLOW INTO IWD
AND PERSISTENT SUBSIDENCE MAY CAUSE THE LO CLDS TO BREAK UP AT THIS
SITE LATER TNGT...BUT LGT WIND SPEEDS MAY CAUSE THIS DOWNSLOPE
COMPONENT TO BE NEGLIGIBLE. SO MAINTAINED MVFR FCST FOR NOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 AM EST SUN DEC 1 2013
EXPECT NE WINDS UP TO 20 KTS EARLY THIS MORNING TO DIMINISH UNDER
15 KTS AND SLOWLY VEER INTO MON AS A WEAK PRES GRADIENT EXTENDING S
FROM HI PRES MOVING THRU ONTARIO DOMINATES THE UPPER LAKES. STRONGER
E TO SE WINDS UP TO 25 TO PERHAPS 30 KTS WILL THEN DEVELOP INTO MID
WEEK AS THE GRADIENT SHARPENS OVER LAKE SUP BETWEEN THE HI PRES
SHIFTING INTO QUEBEC AND LO PRES MOVING NE FROM THE PLAINS. THERE
WILL BE A SHARP WIND SHIFT TO THE WNW BY THU FOLLOWING THE PASSAGE
OF THE LO TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE A W GALE ON THU INTO FRI.
&&
.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...UPDATED AVIATION
NWS ST LOUIS MO
555 AM CST Sun Dec 1 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Sun Dec 1 2013
Think the challenge for today will be forecasting cloud cover. A
stratus deck between 4000-5000ft is moving across he eastern Ozarks
and parts of Southern Illinois this morning. Think this area of
stratus will continue advecting eastward faster than the western
edge will erode as has been the case for the past few hours.
Therefore there should be substantial cloud cover over southeast
Missouri and parts of southern Illinois this morning. The 00Z NAM
eventually cleared it out and this matches well with satellite
trends at this time; however the RAP backbuilds the cloud cover, as
does the 06Z NAM and this suggests that areas generally southeast of
a line from Vichy, MO to Salem, IL may not see much sun today. Am
sticking closer to the less cloudy solution at this time, but this
may ultimately prove to be too optimistic.
Temperatures may be challenging as well. Can`t seem to forecast
warm enough the past couple of days. Missed highs both Friday and
Saturday by to to three degrees. Lingering cloud cover over the
eastern Ozarks and southwest Illinois may make this especially
challenging. For highs today, used a blend of 925 mix-down
temperatures and MOS. Tweaked southern zones down a couple of
degrees from that to account for cloud cover, and the rest of the
area up a degree or two to try to compensate for my apparent cool
bias.
Britt
.LONG TERM: (Tonight through Saturday)
Issued at 335 AM CST Sun Dec 1 2013
(Tonight - Tuesday)
Have not made too many changes to going forecast during this
period. Low level moisture progs suggest that stratus will
redevelop this evening, particularly over the southern and
eastern part of the CWA. Have kept chance of light drizzle in
these areas where this moisture will be the deepest and there will
be some very light ascent. As we go into Monday, GFS/NAM/ECMWF all
show a weak shortwave trough racing into the area from the west,
though it is not as deep as was forecast 24 hours ago. Have left
chance of sprinkles in for tomorrow morning as the trough axis
will move through the area by midday.
Temperatures will begin to warm up ahead ahead of the next storm
system. Expect temperatures to climb into the 50s on Monday with
some spots reaching 60 on Tuesday.
(Wednesday - Saturday)
Main concern continues to be the potential for a wintry precipitation
and the big cool down mid to late week. There still ia a great
deal of uncertainty regarding timing, precipitation types and
amounts. While the GFS is still the fastest with the passage of
the cold front, the 00Z ECMWF now brings the cold front through
the area during the day on Wednesday instead of Wednesday Night.
The cold front will have moved to the south of the area
Wednesday. Best forcing for precipitation will hinge on mid-level
frontogenesis and shortwave troughs moving through fast west-
southwesterly flow aloft. Have likely pops on Thursday and
Thursday Night over southeastern half of the CWA with the chance
continuing into Friday. Will continue to have a simple mix of rain
and snow because of the uncertainty for now, but thermal profiles
from forecast soundings certainly suggest the potential for sleet
or freezing rain over the southern half of the CWA. 850mb
temperatures by next Friday and Saturday will be in the -10 to
-12C range supporting highs only in the 20s with lows in the
single digits and teens.
Britt
&&
.AVIATION: (For the 12z TAFs through 12z Monday Morning)
Issued at 541 AM CST Sun Dec 1 2013
Primary concern this morning is an area of fog over central
Missouri where VSBYS AOB 1SM are being reported. Expect this fog
to lift and dissipate after 14Z this morning. Some patchy fog
with VSBYS between 2-5SM have been reported further east this
morning as well, however the lower VSBYS have been intermittent.
At any rate, expect VFR flight conditions to prevail after 15-16Z
this morning. Am concerned that fog will again be an issue tonight
after 06Z. Not sure yet how low to go, so started out with MVFR
conditions, but will not be surprised to see lower VSBYS by 12Z
Monday morning. Winds will be variable through 12Z Monday as a
weak cold front becomes nearly stationary over the area, and then
begins to drift back to the north late in the period.
Specifics for KSTL:
Expect VFR flight conditions to prevail at Lambert at least
through 06Z tonight. Guidance is hinting that there could be some
MVFR VSBYS in fog after 06Z tonight, and I have lowered VSBYS in
the other STL Metro TAFs; however it`s tough to get fog at Lambert
due to the metro heat island so have left mention of fog out for
now. Winds will be pretty wishy-washy over the next 24 hours as a
weak cold front becomes nearly stationary over the area, but the
wind will pick up from the south after 12Z Monday as the front
moves back to the north.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
947 AM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE WILL GRADUALLY DEVELOP OFF THE CAROLINA COAST LATE
TODAY INTO TONIGHT...MOVING OUT TO SEA MONDAY. WEAK HIGH PRESSURE
WILL MOVE ACROSS THE AREA TUESDAY AND OFFSHORE WEDNESDAY...BRINGING
SEVERAL DAYS OF WARM TEMPERATURES LATE THIS WEEK. THE NEXT COLD
FRONT WILL APPROACH FROM THE WEST SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...MODELS OVER THE PAST TWO DAYS HAVE DONE AN
ABYSMAL JOB FORECASTING HOW THE WEATHER HAS ACTUALLY UNFOLDED OVER
THE PAST 6-12 HOURS. NOT ONLY IS ISENTROPIC LIFT STRONGER AND
COVERAGE OF SHOWERS MORE WIDESPREAD NOW OVER THE COASTAL WATERS THAN
WAS EXPECTED...BUT THE 06Z GFS AND NAM PLUS THE 12Z RUC PAINT A
PICTURE OF DRIER WEATHER DEVELOPING INTO TONIGHT AS WHAT ISENTROPIC
LIFT WE CURRENTLY HAVE TRICKLES OFFSHORE AND DRIER AIR ARRIVES FROM
THE WEST AND SOUTHWEST WITHIN THE 5000-10000 FOOT LAYER.
COMPARED TO 12Z SOUNDINGS ALL THE MODELS ARE STRUGGLING WITH WHAT IS
GOING ON BELOW 10000 FEET THIS MORNING. THIS WAS PARTICULARLY
APPARENT AT CHS WHERE THE GFS HAD A HORRIBLE HANDLE (TOO WET) ON
MOISTURE WITHIN THE 800-900 MB LAYER. ALL THE MODELS FAILED TO
PROPERLY SHOW WARM TEMPERATURES BETWEEN 850-1000 MB OBSERVED ON THE
MHX SOUNDING. NEEDLESS TO SAY...THIS CASTS DOUBT ON WHAT (IF ANY)
MODEL GUIDANCE IS TRUSTWORTHY GOING FORWARD THROUGH THIS AFTERNOON
INTO TONIGHT.
MY CURRENT IDEA (BASED ON CURRENT RADAR AND SATELLITE IMAGERY
SPRINKLED WITH RUC/HRRR GUIDANCE THROUGH THE AFTERNOON) IS FOR A
MUCH DRIER AFTERNOON THAN WAS EXPECTED. I HAVE REMOVED POPS FOR THE
PEE DEE COUNTIES IN SOUTH CAROLINA AND TRIMMED BACK POPS ALONG THE
COAST TO NO HIGHER THAN 30-40 PERCENT...HIGHEST ACROSS SOUTHPORT/
CAROLINA BEACH. WITH NO PRECIPITATION INLAND AND SATELLITE IMAGERY
SHOWING BREAKS IN THE OVERCAST ACROSS MUCH OF CENTRAL AND EASTERN
SOUTH CAROLINA I HAVE RAISED FORECAST HIGHS BY 3-4 DEGREES FROM
FLORENCE TO LUMBERTON...WITH UPPER 50S EXPECTED FOR MOST AREAS THIS
AFTERNOON. DRIER AIR ARRIVING THIS AFTERNOON WITHIN THE LAYER
CURRENTLY GENERATING ISENTROPIC LIFT AND SHOWERS (6000-10000 FT)
SHOULD LEAD TO DRY CONDITIONS EVEN ALONG THE COAST. SURPRISINGLY...
THIS DRIER TREND MAY EVEN CONTINUE INTO TONIGHT AS THE 06Z MODELS
(FOR WHAT THEY`RE WORTH) SHOWING SHOWERS REMAINING MAINLY OFFSHORE.
LET`S HOPE THE 12Z RUNS CAN LEND A HAND WITH THAT PORTION OF THE
FORECAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...A SLEW OF SHORTWAVES WILL CROSS THE CAROLINAS,
GA, AND NRN FL ON MONDAY...SOMEWHAT CONGEALING OFF THE SOUTHEAST
COAST LATE IN THE DAY. THE RESULTING SURFACE WAVE OF LOW PRESSURE
THAT HAD BEEN PROGGED TO DEVELOP NOW LOOKS CONSIDERABLY WEAKER.
MORNING RAIN CHANCES ASSOCIATED WITH THIS FEATURE WILL BE FOCUSED
ALONG THE CAPE FEAR/COASTAL NC ZONES BEFORE DECREASING PERHAPS
RAPIDLY LATER IN THE DAY AS DIFFERENTIAL VORTICITY ADVECTION TURNS
QUITE NEGATIVE AND THE LOW LEVEL UPGLIDE LOOKS TO SHUT OFF AS WELL.
TUESDAY THEN BRINGS ZONAL MID LEVEL FLOW THAT SHOULD KEEP THINGS
DRY. AT THE SURFACE THERE WILL WON`T BE MUCH GRADIENT AS A WEAK HIGH
OVER THE CAROLINAS FILLS THE SPACE IN BETWEEN THE DEEPENING ATLANTIC
LOW AND A LARGE SYSTEM GATHERING STRENGTH OVER THE NRN PLAINS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...RIDGE AXIS TO DRIFT OFFSHORE ON WEDNESDAY PAVING
THE WAY FOR SOME RETURN FLOW. EXPECT ABOVE NORMAL HIGHS FOR THE
FIRST TIME IN QUITE A WHILE DESPITE POSSIBLE INCREASE IN LOW TO MID
LEVEL CLOUDINESS. THURSDAY TOO WILL BE MILD AND RATHER CLOUDY AS THE
RETURN FLOW VEERS SOMEWHAT DUE TO THE APPROACH OF A COLD FRONT FROM
THE WEST. THE NE TO SW ORIENTATION OF THE BOUNDARY WILL HAVE IT
QUITE LINED UP WITH THE MID LEVEL FLOW MAKING FOR VERY SLOW
PROGRESSION. IN FACT WE SEE SOME DIFFERENCES IN THE SPEED AT WHICH
THE BOUNDARY APPROACHES AND MOVES THROUGH BETWEEN VARIOUS MODELS.
GIVEN THE VERTICAL DIRECTIONAL ALIGNMENT OF THE FLOW THE SLOWER
SOLUTIONS SEEM MORE PLAUSIBLE.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...QUITE A BIT OF STRATA CUMULUS OVER THE CWA...LOWEST AT
THE MYRTLES. THE STRATA CU WILL BE IN AND OUT...REPLACED WITH A MID
CLOUD CEILING THIS AFTERNOON. THE GRADIENT WILL BE VERY WEAK TODAY
WITH HIGH PRESSURE CENTERED OVERHEAD...PERHAPS LIGHT AND VARIABLE
WOULD BEST DESCRIBE THE WINDS TODAY. LOW PRESSURE DEVELOPS OFFSHORE
TONIGHT...WITH A FEW SPRINKLES POSSIBLE. AN MVFR CEILING IS POSSIBLE
THIS EVENING.
EXTENDED OUTLOOK...CHANCE OF RAIN ON MONDAY WITH INTERMITTENT
MVFR/IFR CONDITIONS EXPECTED. MAINLY VFR TUESDAY THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM SUNDAY...FAIRLY WIDESPREAD SHOWER ACTIVITY COVERS THE
OUTER PORTION OF THE COASTAL WATERS THIS MORNING...EXCEPT NEAR CAPE
FEAR WHERE THE SHOWERS ARE ALSO OCCURRING IN THE NEARSHORE WATERS.
THIS IS OCCURRING IN ASSOCIATION WITH A WEAK COASTAL TROUGH NEAR THE
WESTERN EDGE OF THE GULF STREAM. NORTH WINDS SHOULD VEER A LITTLE
MORE NORTHEASTERLY BY THIS AFTERNOON...WITH NO INCREASE IN WIND
SPEEDS EXPECTED. SEAS ARE THE BIG STORY AWAY FROM SHORE AS A
PERSISTENT 9-SECOND EASTERLY SWELL CONTINUES TO BRING SIGNIFICANT
WAVE ENERGY INTO THE AREA. THE GENESIS REGION FOR THIS SWELL IS
ACTUALLY WELL OUT INTO THE CENTRAL ATLANTIC WHERE A COUPLE THOUSAND
MILES OF EASTERLY FLOW ALONG THE SOUTH SIDE OF NORTH ATLANTIC HIGH
PRESSURE IS BUILDING QUITE A WAVE FETCH. SEAS OUT AT FRYING PAN
SHOALS ARE AROUND 5 FEET DUE TO THIS SWELL...WITH 3 FEET REPORTED AT
THE BUOY SEVERAL MILES SOUTH OF THE MOUTH OF THE CAPE FEAR RIVER.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...A SERIES OF CONGEALING UPPER LEVEL DISTURBANCES
WILL FORM A SURFACE LOW OFF THE COAST BY MONDAY MORNING. THIS
FEATURE IS NOW SUPPOSED TO BE WEAKER THAN EARLIER FORECASTS AND
POSSIBLY FURTHER OUT TO SEA AS WELL. THIS INCREASES FORECAST
CONFIDENCE THAT NO ADVISORIES OR HEADLINES WILL BE NEEDED AT THIS
TIME AS WINDS MAY BE CAPPED IN THE 10 TO 15 KT RANGE OVER NORTHERN
ZONES WITH PERHAPS JUST 10 KT SOUTH. EVEN LIGHTER WINDS AND SEAS MAY
BE IN THE OFFERING ON TUESDAY AS THIS SYSTEM EXITS AND ANOTHER
DEVELOPS OVER THE NORTHERN PLAINS...WITH ONLY A WEAK HIGH IN BETWEEN
OVER THE CAROLINAS.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...WIND SWINGS AROUND TO THE SOUTH ON WEDNESDAY AS
THE CENTER OF HIGH PRESSURE MOVES OFF THE COAST. NO REAL INCREASE IN
WIND SPEED TO SPEAK OF HOWEVER SO SEAS MAY ACTUALLY CONTINUE TO
SETTLE SOME FROM THEIR TUESDAY VALUES. A COLD FRONT WILL APPROACH
FROM THE NW ON THURSDAY ALBEIT QUITE SLOWLY AS THE BOUNDARY WILL BE
ALIGNED WITH ITS MID LEVEL STEERING FLOW. THE SLOW APPROACH OF THE
FRONT WILL VEER THE WIND SLIGHTLY AND YIELD A GRADUAL INCREASE IN
WIND SPEED. THIS WILL CONTINUE INTO THURSDAY NIGHT AT WHICH TIME
SEAS WILL START RESPONDING TO THE INCREASED FLOW AND FETCH DURATION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS RALEIGH NC
647 AM EST SUN DEC 1 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE REGION TODAY. LOW PRESSURE DEVELOPS
ALONG THE CAROLINA COAST TONIGHT AND GRADUALLY STRENGTHENS AS IT
MOVES AWAY FROM THE REGION MONDAY. HIGH PRESSURE THEN RETURNS FOR
TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 300 AM SUNDAY...
THE SURFACE RIDGE AXIS EXTENDED NORTHEAST TO SOUTHWEST ACROSS
CENTRAL NORTH CAROLINA...WITH A SLACK GRADIENT IN PLACE. IN A FAST
WESTERLY FLOW ALOFT...AS ONE MID-LEVEL SHORTWAVE EXITED CENTRAL
NORTH CAROLINA TO THE EAST...ANOTHER WAS MOVING IN FROM THE TENNESEE
VALLEY. THE 00Z RAOB ANALYSIS SHOWED GREATER 850MB AND 700MB
MOISTURE JUST TO OUR SOUTH...AND SOME OF THIS MOISTURE HAS ADVECTED
NORTH...TO ABOUT U.S. 64. THE NAM AND THE GFS ARE FAIRLY SIMILAR AND
BOTH HAVE TRENDED DRIER CERTAINLY FROM THE PREVIOUS 00Z RUN...SUCH
THAT THE MID LEVELS TEND TO BE FAIRLY DRY FOR MUCH OF THE DAY
TODAY...WITH THE GREATEST MID-LEVEL MOISTURE OVER THE SOUTHERN
COASTAL PLAIN RELATIVE TO THE REST OF CENTRAL NORTH CAROLINA. THE
BEST 850MB LIFT IS CERTAINLY IN THE SOUTHEAST PART OF CENTRAL NORTH
CAROLINA TODAY WHERE 850MB THETA-E ADVECTION IS GREATEST. FAINT
RADAR RETURNS AND GUIDANCE FROM THE HRRR WRF SUGGEST A SMALL CHANCE
OF SPRINKLES IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN THIS
MORNING...WITH A CHANCE OF RAIN MAINLY THIS AFTERNOON ALONG AND
SOUTH OF A LINE FROM ABOUT KRWI TO KRCZ...WITH THE BEST CHANCE
TOWARD KCTZ IN VICINITY OF GREATER MOISTURE AND LIFT.
PRECIPITATION...IF ANY...SHOULD BE LIGHT...WITH THE GREATER
PROBABILITY OF PLURAL HUNDREDTHS IN SAMPSON AND POSSIBLY INTO WAYNE
COUNTIES AS OF THIS WRITING.
1000-850MB THICKNESSES WOULD SUPPORT WARMER TEMPERATURES THAN
FORECAST BY ABOUT A CATEGORY...BUT A BLEND OF GUIDANCE WORKED WELL
FOR SATURDAY HIGHS...AND WILL FOLLOW THE SAME FOR TODAY. FEWER AND
THINNER CLOUDS NORTHWEST...MORE TOWARD THE SOUTHEAST BUT WITH HIGHER
THICKNESSES AND MORE MOIST...RESULT IN A FAIRLY UNIFORM TEMPERATURE
FORECAST IN THE LOWER TO POSSIBLY MID 50S. WINDS SHOULD BE
LIGHT...WITH THE RELATIVELY GREATER SPEEDS TOWARD THE TRIAD...WHILE
STILL UNDER 10KT...FROM THE SOUTHWEST...WEST OF THE SURFACE RIDGE
AXIS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 300 AM SUNDAY...
AGAIN THE NAM AND GFS ARE FAIRLY SIMILAR IN THE EVOLUTION OF THE
SURFACE LOW ALONG THE COAST...WITH AN INVERTED TROUGH DEVELOPING
EARLY TONIGHT FOLLOWED BY WEAK CYCLOGENESIS OVERNIGHT...THEN LOW
PRESSURE GRADUALLY STRENGTHENING MONDAY AS IT MOVES AWAY FROM THE
COASTAL CAROLINAS. 850MB LIFT IS NOT VERY STRONG OVERNIGHT INTO
MONDAY AFTERNOON...WITH THE GFS IN PARTICULAR HAVING TRENDED FARTHER
SOUTH WITH THE PASSAGE OF ITS MODERATE MID-LEVEL SHORTWAVE
ACCOMPANYING THE MID-LEVEL TROUGH. JET SUPPORT ALSO LOOKS TO HAVE
SHIFTED FARTHER SOUTH COMPARED TO RECENT RUNS. K INDICES ARE HIGHEST
TOWARD THE COAST LATE TONIGHT AND MONDAY MORNING...BUT 850MB THETA-E
STILL REMAINS MODEST WEST THROUGH THE COASTAL PLAIN...AND WITH THE
WEAK LIFT AS LOW PRESSURE ORGANIZES JUST OFFSHORE...WILL CONTINUE AT
LEAST A CHANCE OF RAIN EARLY TONIGHT MAINLY EAST OF INTERSTATE 95
WHEN OVERALL MOISTURE APPEARS HIGHEST FOR THE NIGHTTIME HOURS...
THEN AGAIN MAINLY MONDAY MORNING ALONG AND EAST OF ABOUT U.S. 1
DURING A PERIOD OF A MODEST INCREASE IN MID-LEVEL MOISTURE IN
CONJUNCTION WITH GOOD LOWER-LEVEL MOISTURE. FOR NOW WILL KEEP
CHANCES BELOW LIKELY GIVEN THE DRIER MODEL TRENDS...NO MOS GUIDANCE
IN CENTRAL NORTH CAROLINA CLOSE TO LIKELY...AND NAM AND GFS MODEL
QPF BEING PRETTY LOW. PLAN TO KEEP THE TRIAD AND THE FAR WESTERN
PIEDMONT DRY THIS PERIOD.
850MB THETA-E TROUGHINESS STARTS TO PUSH EAST MONDAY AFTERNOON WITH
INCREASING SUBSIDENCE. BUFR SOUNDINGS ARE FAIRLY STABLE AND DRYING
CERTAINLY BY 00Z TUESDAY...AND PRECIPITABLE WATER VALUES ARE AT OR
BELOW A HALF-INCH MONDAY NIGHT. WILL NOTE CHANCES BELOW SLIGHT IN
CENTRAL NORTH CAROLINA BY 00Z TUESDAY. LOWS TONIGHT AND HIGHS MONDAY
ARE A LITTLE TRICKY GIVEN THE UNCERTAINTY SURROUNDING CLOUD COVER
AND THE POTENTIAL VARIABLE THICKNESS OF SUCH CLOUD COVER. OPTED TO
TRIM LOWS TONIGHT SLIGHTLY ESPECIALLY ALONG AND NORTH OF INTERSTATE
85 WHERE CLOUD COVER SHOULD BE LEAST AND THINNEST OVERNIGHT. GIVEN
THE DRIER MODEL TREND OPTED TO RAISE MAXES INTO THE 50S THROUGHOUT
CENTRAL NORTH CAROLINA MONDAY...STILL KEEPING THE WARMER READINGS
OVER THE WESTERN PIEDMONT FOR NOW. OVERNIGHT LOWS MONDAY NIGHT NEAR
THE COOLER MAV MOS GUIDANCE ANTICIPATING FEWER CLOUDS...LOWER TO MID
30S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...
WEAK HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY IN THE WAKE
OF THE DEPARTING COASTAL CYCLONE AS A WESTERLY FLOW DEVELOPS ALOFT.
FAIR WEATHER IS EXPECTED IN CENTRAL NC WITH A FEW LAYERS OF CLOUDS.
HIGHS WILL RANGE IN THE LOWER 50S NORTHEAST TO NEAR 60 TOWARD THE SC
BORDER.
HEIGHTS BEGIN RISING ON WEDNESDAY AND THURSDAY AS A BROAD TROUGH
DEVELOPS IN THE ROCKIES AND THE NORTHERN PLAINS. AN INCREASINGLY
MOIST SOUTHERLY FLOW WILL PROMOTE AN INCREASE IN CLOUDINESS ON
WEDNESDAY AND THURSDAY WITH WARMING TEMPERATURES ESPECIALLY ON
THURSDAY. BOTH THE EC EFS AND THE GFS HIGHLIGHT A SHALLOW
DISTURBANCE THAT WILL MOVE NORTHEAST ACROSS THE AREA ON WEDNESDAY
THAT SHOWS UP AS A REGION OF ISENTROPIC UPGLIDE IN THE 290-295
LAYER. DON`T EXPECT ANY PRECIPITATION AT THIS TIME BUT HAVE
INCREASED CLOUD PERCENTAGES DURING THE PERIOD. GFS BUFR SOUNDINGS
ALSO SUGGEST THAT THERE COULD BE SOME GUSTY WINDS ON WEDNESDAY
AFTERNOON WITH GUSTS UP TO 20-25 MPH AS MIXING TAPS INTO THE
STRONGER FLOW ASSOCIATED WITH THE LOW LEVEL JET. A SLIGHTLY BETTER
CHANCE OF RAIN ARRIVES IN THE NORTHWESTERN PORTION OF THE FORECAST
AREA LATE THURSDAY AND ESPECIALLY THURSDAY NIGHT AS A COLD FRONT
APPROACHES THE REGION FROM THE WEST. TEMPERATURES SHOULD WARM INTO
THE MID 50S TO NEAR 60 ON ON WEDNESDAY AND THEN THE 60S TO NEAR 70
ON THURSDAY.
DIFFERENCES IN THE GFS AND EC EFS BECOME MORE APPARENT ON FRIDAY AND
ESPECIALLY SATURDAY WITH THE GFS BEING FASTER AND PUSHING THE FRONT
THROUGH THE AREA LATE FRI/EARLY SAT WITH THE EC PERHAPS 12 HOURS
SLOWER. WHILE THE BEST FORCING FOR ASCENT STAYS NORTH OF THE
AREA...THE PLUME OF DEEP LAYER MOISTURE AND FORCING ASSOCIATED WITH
THE FRONT SHOULD BE SUFFICIENT FOR CHC POPS. MILD TEMPERATURES ARE
EXPECTED ON FRIDAY AHEAD OF THE FRONT AND AHEAD OF THE MAIN AREA OF
RAIN. MAX TEMPS HAVE BEEN ADJUSTED UPWARD INTO THE UPPER 60S
NORTHWEST TO NEAR 75 IN THE SOUTHEAST. ALSO ADJUSTED MIN TEMPS ON
SATURDAY UPWARD TO ACCOUNT FOR THE CLOUDS AND MILD CONDITIONS AHEAD
OF THE FRONT. MAX TEMPS ON SATURDAY WILL BE LIMITED GIVEN THE CLOUDS
AND AREAS OF LIGHT RAIN BUT STILL EXPECT TEMPS TO REACH THE UPPER
50S NORTHWEST TO MID 60S SOUTHEAST. AT THIS POINT WE DON`T EXPECT
ANY THUNDERSTORMS LATE FRIDAY INTO SATURDAY THUNDERSTORMS GIVEN THE
MARGINAL MID LEVEL LAPSE RATES.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 645 AM SUNDAY...
MOSTLY VFR CONDITIONS WILL CONTINUE THROUGH THE 12Z VALID TAF
PERIOD. AREAS OF MVFR CONDITIONS NEAR INTERSTATE 95...EVEN VERY
BRIEFLY IFR AT KRWI...SHOULD END BY 14Z BASED ON TRENDS ON
OBSERVATIONS AND THE SATELLITE FOG PRODUCT. MAINLY DURING THE
AFTERNOON AND EVENING PATCHY LIGHT RAIN IS POSSIBLE SOUTH OF A LINE
FROM ABOUT KFAY TO KRWI. THIS IS WHERE ANY THICKER CLOUDS SHOULD
RESIDE DURING THAT TIME...THOUGH THEY ARE EXPECTED CURRENTLY TO HAVE
THE HIGHEST PROBABILITY OF BEING VFR. WITH HIGH PRESSURE OVERHEAD...
WINDS SHOULD BE SOMEWHAT VARIABLE. JUST ON THE WEST SIDE OF THE
SURFACE RIDGE AXIS...WINDS SHOULD BE MORE SOUTHWEST TOWARD THE
TRIAD. WINDS SHOULD TEND TO FAVOR NORTHERLY TOWARD KFAY. AT KRWI AND
ESPECIALLY KRDU...THE LIGHT SURFACE WIND DIRECTION IS MORE
CHALLENGING...BUT WILL CONTINUE TO LEAN WESTERLY DURING THE DAYLIGHT
HOURS WITH THE CONSENSUS OF GUIDANCE BEING CONSISTENT IN SHOWING
THAT DIRECTION...THOUGH IT COULD BE QUITE VARIABLE.
BEYOND THE 12Z VALID TAF PERIOD...VFR CONDITIONS WILL BE FORECAST.
AN ALTERNATIVE IS THE PROBABILITY OF SUB-VFR CONDITIONS OVERNIGHT
INTO MONDAY MORNING IN CLOUDS AND PATCHY LIGHT RAIN ALONG AND EAST
OF INTERSTATE 95...LEANING MVFR AS A CATEGORY IF IT OCCURS...WITH A
CHANCE OF SUB-VFR CONDITIONS IN LIGHT FOG TOWARD THE TRIAD WHERE
CLOUDS SHOULD BE LESSER AND THINNER. KRDU WILL BE IN BETWEEN...AND
IT IS POSSIBLE FOR A PERIOD OF BOTH LIGHT FOG AND LOWER CLOUDS THERE
BEFORE DRIER AIR AND SUBSIDENCE MOVE IN FROM THE WEST...CREATING
WIDESPREAD VFR CONDITIONS ACROSS CENTRAL NORTH CAROLINA BY LATE
MONDAY AFTERNOON. MVFR CONDITIONS IN FOG ARE POSSIBLE LATE MONDAY
NIGHT AND EARLY TUESDAY...THEN AS MOISTURE INCREASES...THERE IS A
CHANCE OF SUB-VFR CONDITIONS IN LOW CLOUDS TUESDAY NIGHT INTO
WEDNESDAY...WITH GREATER CHANCES OF THOSE CONDITIONS CURRENTLY
TOWARD THE TRIAD THOUGH POSSIBLE THROUGHOUT CENTRAL NORTH CAROLINA
PARTICULARLY WEDNESDAY NIGHT.
&&
.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
650 AM CST SUN DEC 1 2013
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 418 AM CST SUN DEC 1 2013
00Z/06Z MODELS ARE COMING MORE IN LINE TOWARD A GENERAL CONSENSUS
SOLUTION...WITH THE GFS REMAINING A FAST OUTLIER. EVEN THE NAM IS
SIMILAR TO THE CONSENSUS...JUST STRONGER. THE IDEA IS THAT AN
UPPER LOW WILL DIG INTO THE NORTHWEST CONUS/NORTHERN
ROCKIES...THEN EJECT INTO NORTHERN MINNESOTA BY 12Z WED. MODELS
HAVE REMAINED CONSISTENT INDICATING 3 ROUNDS OF SNOWFALL.
THE FIRST ROUND WILL BE LATER THIS AFTERNOON INTO TONIGHT.
FORCING IS WEAK AND AVAILABLE MOISTURE IS RELATIVELY
LOW...THINKING UP TO AN INCH OF SNOWFALL IS MOST LIKELY.
THE SECOND WAVE (MONDAY INTO MONDAY NIGHT) 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 WESTERN MN ON MONDAY...LOSING DEFINITION MONDAY
NIGHT AS IT PROPAGATES FURTHER TO THE EAST. ASSOCIATED WARM AIR
ADVECTION/FRONTOGENESIS COMBINED WITH THE 0.5 INCH PWATS SHOULD
LEAD TO A BAND OF SNOWFALL MOVING THROUGH THE REGION. MODELS
INDICATE 0.20-0.40 INCHES QPF ACROSS ALL BUT THE NE FA...AND
COMBINED WITH 12:1-13:1 SNOW RATIOS WOULD LEAD TO AN AREA OF 2-5
INCHES OF SNOW. MODELS INDICATE THAT THE MESOSCALE FORCING IS
RELATIVELY WEAK...WHICH WOULD MEAN THE MODELS SHOULD BE IN THE
BALL PARK WITH QPF.
THE THIRD ROUND OF SNOWFALL (TUESDAY-TUESDAY NIGHT) WILL BE
ASSOCIATED WITH THE MAIN STRONG MID-LEVEL LOW MOVING THROUGH THE
REGION. THE 00Z ECMWF IS SLIGHTLY FASTER WITH THIS FEATURE.
SYNOPTIC FORCING WILL BE VERY STRONG...WITH THE POTENTIAL FOR
MESOSCALE BANDING. WITH THAT SAID...THIS ROUND OF SNOWFALL STILL
HAS THE MOST UNCERTAINTY (DUE TO MODEL DIFFERENCES). GIVEN THE
AVAILABLE MOISTURE (PWATS 0.5+ INCHES) AND STRONG FORCING
EXPECTED...ALONG WITH THE SLOW MOVING NATURE OF THE SYSTEM...THIS
ROUND SHOULD BRING 6+ INCHES (CURRENT THOUGHTS ARE 5 TO 10 INCHES)
TO MOST AREAS. SOMETIME TOWARD THE TAIL END OF THE
SNOWFALL...WINDS SHOULD INCREASE...LIKELY STRONG ENOUGH FOR
BLOWING SNOW ISSUES.
SINCE THE TRUE WINTER WARNING CONDITIONS WILL LIKELY NOT OCCUR
UNTIL SOMETIME ON TUESDAY...WILL HOLD OFF ON ISSUING ANY
WINTER HEADLINES. THIS WILL ALLOW FOR ANOTHER SET OF MODEL RUNS TO
INCREASE CONFIDENCE. COULD SEE A SITUATION WHERE WE HAVE ADVISORY
CONDITIONS ON MONDAY/MONDAY NIGHT FOLLOWED BY A SHORT BREAK...THEN
WARNING CRITERIA SNOW TUESDAY/TUESDAY NIGHT (WITH WINDS AND
BLOWING SNOW LATER TUESDAY NIGHT INTO WEDNESDAY). WILL ADD SOME
DETAIL TO THE SPECIAL WEATHER STATEMENT AND HWO.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 418 AM CST SUN DEC 1 2013
WEDNESDAY-SATURDAY...BOTH THE GFS/ECMWF INDICATE SNOW WINDING
DOWN ON WEDNESDAY AS THE SFC LOW PULLS AWAY. DESPITE A TREND
TOWARDS A FASTER SOLUTION...THERE IS STILL SOME UNCERTAINTY WITH
THE 00Z GEM SLOWER WITH THE SFC LOW...KEEPING SNOW AROUND THROUGH
WEDNESDAY NIGHT. SOME LIGHT SNOW/SNOW SHOWERS COULD LINGER INTO
LATE WEEK AS A REINFORCING UPPER LOW PIVOTS SOUTHWARD INTO THE
REGION...MAINTAINING CYCLONIC FLOW. HOWEVER...THE MAIN CONCERN FOR
THE REMAINDER OF THE WEEK WILL BE TEMPS AS A BITTERLY COLD ARCTIC
AIR MASS TAKES UP RESIDENCE ACROSS THE NORTHERN PLAINS. BASED ON A
MORE PROGRESSIVE SOLUTION...STRONG LOW-LEVEL COLD ADVECTION MAY
PREVENT MUCH TEMPERATURE RISE ON WEDNESDAY. 1000-500 MB
THICKNESSES FALL BELOW 500 DAM BY THURSDAY/FRIDAY...WITH HIGHS NO
HIGHER THAN THE LOW SINGLE DIGITS. MODELS INDICATE THE SFC HIGH
AXIS DOES NOT APPROACH UNTIL NEXT WEEKEND. THUS...WITH ONLY A
GRADUAL SLACKENING OF THE PRESSURE GRADIENT...WINDS WILL REMAIN UP
A BIT THROUGH THE WORK WEEK. THE COMBINATION OF WINDS AND BITTERLY
COLD TEMPS LIKELY WILL LEAD TO DANGEROUS WIND CHILLS AT TIMES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CST SUN DEC 1 2013
IFR CONDITIONS WILL LIKELY CONTINUE THROUGH THE MORNING
HOURS...GRADUALLY RISING WITH DAYTIME HEATING (BUT NOT GREATER
THAN MVFR CRITERIA). 10Z RAP GUIDANCE SHOWS THE POTENTIAL FOR A
PERIOD OF VFR CONDITIONS TONIGHT AS LOW LEVEL FLOW INCREASES. THIS
SEEMS LIKE A LOW PROBABILITY OF OCCURRENCE CONSIDERING THAT THE
LOW-LEVEL AIRMASS IS EXPECTED TO REMAIN SATURATED. WILL MONITOR
THE SITUATION AND ADJUST THE FORECASTS AS NEEDED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
538 AM CST SUN DEC 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CST SUN DEC 1 2013
THE MAIN FOCUS IS ON THE INCREASING CHANCES FOR SNOW
TONIGHT...MAINLY IN SOUTHEAST MINNESOTA...NORTHEAST IOWA AND FAR
WESTERN WISCONSIN.
CURRENTLY...NORTHWESTERLY FLOW ALOFT IS IN PLACE WITH A SURFACE
RIDGE OF HIGH PRESSURE CENTERED ON THE EASTERN DAKOTAS. THE
INITIAL QUESTION THIS MORNING IS WITH A STRATUS DECK THAT EXTENDS
ACROSS NORTHERN WISCONSIN/MINNESOTA AND HOW FAR SOUTH IT WILL MAKE
IT TODAY. THERE HAS NOT BEEN MUCH OF A SOUTHERLY PUSH WITH IT OVER
THE PAST 6 HOURS OR SO...EXCEPT IN EASTERN WISCONSIN ALONG LAKE
MICHIGAN. THE PAST FEW RUNS OF THE HRRR SHOW THIS STRATUS DECK
HAVING TROUBLE MAKING IT SOUTH TODAY AS THE RIDGE OF HIGH PRESSURE
COMES IN AND WEAKENS THE NORTHERLY SURFACE FLOW. IF THIS DECK DOES
MAKE IT FURTHER SOUTH...IT WILL CAUSE TEMPERATURES TO BE ABOUT
5-10F COOLER FOR HIGHS.
GOING INTO TONIGHT...A LEAD/WEAK MID LEVEL SHORT WAVE TROUGH WILL
PROPAGATE EAST ACROSS THE NORTHERN PLAINS WHILE ISENTROPIC LIFT ON
THE 290K SURFACE INCREASES. THIS SHOULD PROVIDE ENOUGH
LIFT...ALBEIT WEAK...TO DEVELOP A BAND OF LIGHT SNOW FROM CENTRAL
MINNESOTA DOWN ALONG THE MISSISSIPPI RIVER. ANY ACCUMULATIONS
OVERNIGHT WILL BE ON THE LIGHT SIDE AT A FEW TENTHS OF AN INCH OR
LESS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM CST SUN DEC 1 2013
LIFT AND MOISTURE WILL BECOME DEEPER MONDAY INTO WEDNESDAY AS THE
CORE OF THE MID LEVEL TROUGH APPROACHES THE REGION. FOR
MONDAY...THE MAIN FOCUS CONTINUES TO BE ALONG THE NOSE OF THE LOW
LEVEL WARM AIR ADVECTION AND WHERE IT WILL SET UP. ALL OF THE
01.00Z GUIDANCE SHOW THE BAND OF PRECIPITATION EXPANDING THROUGH
THE DAY AS THIS ADVECTION STRENGTHENS. HOWEVER...AS WARMER AIR
COMES IN AT THE LOW LEVELS...SOME PRECIPITATION TYPE ISSUES ARISE
WITH THE WARM LAYER POSSIBLY CAUSING THE SNOW TO CHANGE OVER TO
RAIN. SURFACE TEMPERATURES SHOULD ALSO BE ON THE RISE ABOVE
FREEZING...SO AM NOT EXPECTING ANY FREEZING RAIN AT THE MOMENT.
THERE IS SOME UNCERTAINTY TOO WITH THE POSITION OF THE NORTHWEST
TO SOUTHEAST SWATH OF PRECIPITATION WITH THE 01.00Z NAM/01.03Z
SREF BEING THE FARTHEST NORTHEAST WHILE THE 01.00Z GFS/ECMWF
DEVELOP IS MORE TO THE SOUTHWEST IN SOUTHEAST MINNESOTA/NORTHEAST
IOWA. MAY BE UNDER-DOING THE SNOW AMOUNTS ON MONDAY...BUT THE
POTENTIAL MIX HAS ME CAUTIOUS TO GO MUCH ABOVE A FEW TENTHS OF AN
INCH.
THE BIGGEST STORY WITH THE 01.00Z GUIDANCE IS HOW THEY HAVE ALL
COME AROUND TO THIS THINKING OF A MUCH FASTER FRONTAL PASSAGE WITH
THE DEEPENING SURFACE LOW/MID LEVEL TROUGH MOVING THROUGH EARLY ON
WEDNESDAY. THE BEST CHANCES FOR ANY PRECIPITATION APPEARS TO BE
FROM MONDAY NIGHT THROUGH WEDNESDAY AS THIS TROUGH APPROACHES. THE
WARMER AIR COMING IN ON TUESDAY AHEAD OF THE SYSTEM SHOULD KEEP
THE P-TYPE MAINLY AS RAIN UNTIL THE COLD FRONT COMES THROUGH EARLY
ON WEDNESDAY. THE MAIN CHANCES FOR SNOW WILL BE ON MONDAY NIGHT
AHEAD OF THE WARM AIR..AND THEN AGAIN ON WEDNESDAY MORNING BETWEEN
THE LEAD COLD FRONT PASSAGE AND THE SECONDARY COLD FRONT WHICH
USHERS IN THE DRASTICALLY COLDER AIR IN. OVERALL...CONFIDENCE IN
GETTING ANY SPECIFIC DETAILS DOWN ON THE PRECIPITATION TRENDS IS
PRETTY LOW...PARTICULARLY WITH THE SNOW AMOUNTS. IF ANY SNOW IS
ABLE TO OCCUR WEDNESDAY MORNING AFTER THE FIRST FRONT COMES
THROUGH...IT WILL MEAN THAT TEMPERATURES COULD BE COLDER THAN
ADVERTISED GOING THROUGH THE REST OF THE WEEK. DUE TO THE FASTER
FROPA...HAVE DROPPED THE PRECIPITATION CHANCES FROM THURSDAY
INTO THE WEEKEND.
AS FOR THE COLD SPELL...850MB TEMPERATURES ARE FORECAST TO DROP
DOWN TO BETWEEN -15 TO -20C ON THURSDAY WITH THE POOL OF COLD AIR
LASTING THROUGHOUT THE REGION PAST NEXT WEEKEND. EVEN IF THERE IS
NO SNOW COVER DOWN ON THE GROUND...TEMPERATURES WILL BE MUCH
BELOW NORMAL THROUGH THE FORESEEABLE FUTURE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 538 AM CST SUN DEC 1 2013
LOWER LEVEL MOISTURE/MVFR STRATUS DECK THAT WAS HEADED TOWARD THE
AREA FROM NORTHERN MN/WI LAST EVENING HAS STALLED EARLY THIS
MORNING...LOOKING TO STRUGGLE WITH THE DOWN-SLOPING NORTH/NORTHEAST
FLOW FROM THE NORTHERN HIGHLAND TERRAIN OF WI. SFC-925MB WINDS FOR
ANY ADVECTION OF THIS MOISTURE/CLOUDS BECOMES LIGHT/VARIABLE TODAY.
HAVE LIMITED LOWER CLOUDS FOR TODAY TO SCT DIURNAL IN THE 2000-2500
FT RANGE DURING THE 17Z-22Z PERIOD. SFC/LOW LEVEL RIDGE AXIS PASSES
THIS EVENING WITH LOWER LEVEL WARM ADVECTION/INCREASING 850-500MB
MOISTURE SPREADING INTO THE AREA. CLOUD DECKS TO THICKEN/LOWER LATE
THIS AFTERNOON/TONIGHT AS THE MOISTURE/SOME LIFTING ARRIVE. MODEL
SIGNAL IS BECOMING MORE CONSISTENT THAT ENOUGH MOISTURE/LIFT WILL BE
PRESENT FOR SOME -SN WEST OF THE MS RIVER LATER TONIGHT. ADDED A
VCSH AFTER 05Z AT KRST FOR NOW AS APPEARS ANY LATE NIGHT -SN WOULD
BE QUITE LIGHT. LEFT CIGS LATER TONIGHT VFR AS WELL...AS BULK OF THE
MOISTURE/CLOUD INCREASE AND LIFTING IS ABOVE 850MB.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
337 AM MST SUN DEC 1 2013
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 337 AM MST SUN DEC 1 2013
WEATHER PATTERN CHANGE BEGINNING TO START TODAY. FORECAST
CHALLENGES DEAL WITH A HIGH WIND EVENT STARTING TODAY AND
PERSISTING THROUGH TUESDAY MORNING.
CURRENTLY...CONDITIONS ARE PRETTY QUIET SO FAR THIS MORNING. SKIES
ARE MOSTLY CLEAR WITH FAIRLY LIGHT WINDS OUTSIDE THE WIND PRONE
AREAS. TEMPERATURES QUITE WARM WITH MAINLY MID TO UPPER 30S BEING
REPORTED. WINDS SO FAR AT OUR WIND PRONE AREAS ARE GUSTING IN THE
UPPER 30S TO LOW 40S AND ARE EXPECTED TO CONTINUE INCREASING AS
THE MORNING PROGRESSES. TO THE NORTHWEST OVER WASHINGTON
STATE...OUR NEXT WINTER STORM COMING ONSHORE OVER SOUTHERN BRITISH
COLUMBIA AND WASHINGTON.
FOR TODAY...THE HIGH WIND EVENT IS STILL ON TRACK WITH LATEST
WRKHGT PRODUCT SHOWING CRAIG TO CASPER 850 AND 700MB HEIGHT
GRADIENTS INCREASING TO NEAR 60MTRS BY 18Z TODAY. THESE GRADIENTS
EXPECTED TO CONTINUE INCREASING THIS AFTERNOON AND OVERNIGHT TO
NEARLY 84 MTRS AT 850MBS AND 81 MTRS AT 700MB BY 12Z MONDAY. THIS
IS GOING TO BE A PRETTY IMPRESSIVE HIGH WIND EVENT AS WE DO NOT
NORMALLY SEE THESE TYPES OF GRADIENTS WITH OUR NORMAL RUN OF THE
MILL HIGH WIND EVENTS. WENT AHEAD AND STARTED THE WIND PRONE
AREAS OF SOUTHEAST WYOMING IN WIND WARNING CRITERIA BY 18Z TODAY.
LATEST MOS GUIDANCE SHOWING RAWLINS AND LARAMIE INCREASING IN
WINDS TODAY THROUGH THE LATE AFTERNOON AND OVERNIGHT. WENT AHEAD
WITH A HIGH WIND WARNING FOR CARBON AND ALBANY COUNTIES BEGINNING
AT 7 PM THIS EVENING. KEPT CONVERSE AND LARAMIE COUNTIES IN THE
HIGH WIND WATCH FOR NOW. DAY SHIFT CAN TAKE ANOTHER LOOK TO
UPGRADE AND/OR EXPAND FURTHER EAST LATER TODAY. LOOKS LIKE WE ARE
GOING TO NEED SOMETHING FOR THE PANHANDLE AS 850MB WINDS INCREASE
TO 45 KNOTS MONDAY MORNING.
ONE LAST THING FOR TODAY IS THE SNOWY AND SIERRA MADRE RANGES.
QPF OUTPUT PRETTY MEAGER FOR THESE TWO ZONES TODAY. STILL THINK
THE OUTPUT IS UNDERDONE...BUT WILL DEFER TO THE DAY SHIFT. DID GO
AHEAD AND ISSUE A WINTER WEATHER ADVISORY FOR SNOW AND BLOWING
SNOW. IF LATER SHIFTS SEE QPF AMOUNTS INCREASING...WE MAY NEED TO
ISSUE A SHORT FUSED WINTER STORM WARNING OUT THAT WAY.
700MB WINDS FOR MONDAY VERY IMPRESSIVE WITH THE 12Z GFS
FORECASTING 70 TO 75KTS AT 06Z TONIGHT AND LASTING THROUGH 06Z
TOMORROW NIGHT AHEAD OF THE APPROACHING COLD FRONT. LOOKS LIKE THE
FRONT MOVES INTO CONVERSE COUNTY LATE MONDAY EVENING AND THROUGH
THE CHEYENNE AREA/SOUTHERN PANHANDLE BY 12Z TUESDAY. PROBABLY WILL
NOT SEE MUCH IN THE WAY OF SNOW EAST OF THE LARAMIE RANGE UNTIL
THE WINDS SWITCH TO THE NORTHEAST BEHIND THE FRONT LATER TUESDAY
MORNING. VERY COLD 700MB TEMPERATURES BEHIND THE FRONT AS
WELL...DROPPING FROM 0C MONDAY AFTERNOON...TO -18C TUESDAY
AFTERNOON.
GOT A CALL FROM AN AREA RANCHER OVERNIGHT. THEY ARE IN THE MIDDLE
OF CALVING SEASON. PASSED ON THAT THEY PROBABLY WANT TO GET THEIR
CATTLE SHELTERED BEFORE TUESDAY AFTERNOON AS TEMPERATURES ARE
GOING TO BE SHARPLY DROPPING AND WIND CHILLS FALL WELL BELOW ZERO
TUESDAY NIGHT.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 337 AM MST SUN DEC 1 2013
00Z MODELS ARE IN FAIR AGREEMENT WITH THE LARGER SCALE SYNOPTIC
PATTERN AS THE DEEP UPPER TROUGH DIGS INTO THE WESTERN CONUS TUESDAY
NIGHT AND WEDNESDAY. A POTENT SHORTWAVE AT THE BOTTOM OF THE
TROUGH LOOKS TO MOVE ACROSS UT/NV AND INTO CO ON WEDNESDAY WITH SFC
CYCLOGENESIS OCCURRING OUT AHEAD OF THE WAVE. THE LOW CENTER IS
PROGGED TO BE OVER SOUTHWESTERN CO BY 18Z WEDNESDAY WITH AN INVERTED
TROUGH DEVELOPING ALONG THE ROCKIES. THIS COULD DO TWO THINGS. FIRST
IT COULD INCREASE NORTHEASTERLY WINDS AND THEREFORE UPSLOPE FORCING
ALONG THE LARAMIE RANGE DEPENDING WHERE EXACTLY THE INVERTED TROUGH
SETS UP. SECOND...IT COULD HOLD BACK THE SURGE OF ARCTIC AIR OVER
THE MOUNTAINS UNTIL LATER IN THE PERIOD. WITH SOME UNCERTAINTY YET
IN THIS SCENARIO...DID NOT MAKE ANY DRASTIC CHANGES TO THE ONGOING
FORECAST FOR POPS...WINDS AND TEMPS THROUGH WEDNESDAY. KEPT HIGHER
POPS OVER THE HIGH COUNTRY WHERE THE STRONGER PVA AND POTENTIAL
NORTHEASTERLY UPSLOPE COULD BE MAXIMIZED. PLENTY OF MOISTURE LOOKS
TO MOVE UP WITH THE SHORTWAVE SO IF THIS SCENARIO IS REALIZED...SNOW
WILL BE WIDESPREAD OVER THIS AREA AND COULD SEE MODERATE RATES AT
TIMES. ONE CAVEAT IS THAT VERY COLD TEMPS COULD LIMIT ACCUMULATION
OVERALL DUE TO A FINER SNOW TYPE. FURTHER EAST...BROADSCALE LIFT
AHEAD OF THE UPPER WAVE WILL BRING A GOOD CHANCE FOR SNOW THROUGH
WEDNESDAY AND WEDNESDAY NIGHT...ESPECIALLY FOR THE SOUTHERN HALF
OF THE CWA.
SNOW WILL STEADILY DIMINISH FROM NORTH TO SOUTH THURSDAY BUT
MODELS SHOW SOME LINGERING LIGHT QPF THROUGH THURSDAY. THIS
SUGGESTS LIGHT SNOW/FLURRIES WILL PERSIST AT TIMES AS THE ARCTIC
HIGH MAKES A STRONGER PUSH TOWARD THE FORECAST AREA AND INDUCES
WEAK UPSLOPE FLOW IN A VERY COLD AIRMASS. SKIES SHOULD BEGIN TO
CLEAR THURSDAY NIGHT WHICH WILL ALLOW TEMPS TO PLUMMET WELL BELOW
ZERO ACROSS THE MAJORITY OF THE FORECAST AREA. HOWEVER...ANY
LINGERING CLOUD COVER WILL IMPACT JUST HOW LOW TEMPS WILL FALL
OVERNIGHT. FRIDAY WILL REMAIN VERY COLD UNDER 700 MB TEMPS OF
MINUS 20 TO MINUS 26...AND LIGHT SNOW/FLURRIES COULD VERY WELL
CONTINUE IN THIS FRIGID ENVIRONMENT. ANOTHER SHORTWAVE WILL
APPROACH FROM THE WEST ON SATURDAY AND WILL REINFORCE THE COLD
AIRMASS AND POTENTIAL FOR LIGHT SNOW ACROSS THE CWA. SO AS IT
STANDS...LOOKS LIKE THIS WILL BE A LONG DURATION COLD
SPELL...WHICH WILL HAVE A HIGH IMPACT ON LIVESTOCK AND ANY PERSONS
PLANNING OUTDOOR RECREATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY MORNING)
ISSUED AT 1027 PM MST SAT NOV 30 2013
SCATTERED TO BROKEN MID LEVEL CLOUDS WILL PREVAIL TONIGHT...WITH
MVFR TO IFR CIGS DEVELOPING OVER WESTERN AND SOUTHERN CARBON
COUNTY BY DAYBREAK SUNDAY. NAM MOS AND HRRR HAVE BEEN CONSISTENT
WITH AT LEAST IFR CIGS INVOF KRWL AND KSAA AIRFIELDS. KEPT
PREVAILING BKN015 THROUGH SUNDAY AFTERNOON AT KRWL. SNOW SHOWERS
WILL DEVELOP AND OBSCURE THE SNOWY AND SIERRA MTNS SUNDAY. IT WILL
BE BREEZY TO WINDY SUNDAY WITH WESTERLY WINDS POSSIBLY GUSTING AS
HIGH AS 50 KT FOR THE WIND CORRIDORS OF SOUTHEAST WY. GUSTS TO 35 KT
ARE EXPECTED ELSEWHERE...EXCEPT 25 KT IN WESTERN NEBRASKA.
&&
.FIRE WEATHER...
ISSUED AT 337 AM MST SUN DEC 1 2013
WIDESPREAD HIGH WIND EVENT STILL ON TRACK TO BEGIN IMPACTING THE
AREA STARTING LATE THIS MORNING AND PERSISTING THROUGH TUESDAY
MORNING. WINDS INITIALLY INCREASING IN OUR SOUTHEAST WYOMING WIND
PRONE AREAS...BUT THEN SPREADING OUT TO OTHER AREAS LATER THIS
AFTERNOON AND TONIGHT. THIS IS ALL DUE TO A PACIFIC LOW PRESSURE
SYSTEM TRACKING INTO MONTANA TODAY. THIS LOW WILL DRAGS A COLD
FRONT THROUGH THE AREA MONDAY AFTERNOON WITH WINDS SHIFTING FROM
WEST TO NORTHEAST BEHIND THE FRONT. WIDESPREAD ACCUMULATING SNOW
AND BITTERLY COLD TEMPERATURES BEHIND THE FRONT FOR MOST AREAS
TUESDAY AND ON THROUGH THE WEEK. SNOW ENDING FOR MOST LOCATIONS BY
THURSDAY...BUT EXTREME COLD TEMPERATURES PERSISTING INTO THE
WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 11 AM MST
MONDAY FOR WYZ112-114.
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 5 AM MST TUESDAY
FOR WYZ106-107-110-116-117.
HIGH WIND WATCH FROM THIS EVENING THROUGH LATE MONDAY NIGHT FOR
WYZ101-118.
HIGH WIND WARNING FROM 7 PM THIS EVENING TO 5 AM MST TUESDAY FOR
WYZ104-105-109-115.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...RJM
AVIATION...JAMSKI
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS TAUNTON MA
430 PM EST SUN DEC 1 2013
.SYNOPSIS...
AN OCEAN STORM WILL LIKELY PASS FAR ENOUGH OFFSHORE TO BRING
SCATTERED RAIN SHOWERS MON NIGHT/TUE ACROSS THE COASTAL PLAIN. HIGH
PRESSURE AND RELATIVELY MILD WEATHER WILL PUSH IN WED AND THU. A
STRONG COLD FRONT WILL APPROACH DURING FRIDAY BRINGING A CHANCE FOR
PRECIPITATION...THEN PROGRESSIVELY COLDER AIR WORKS IN NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
425 PM UPDATE...
LATEST SURFACE MAP ALREADY SHOWING THE TRANSFER OF ENERGY FROM A
WEAK LOW PRESSURE IN THE LOWER GREAT LAKES TO A LOW PRESSURE OFF
THE MID ATLANTIC COAST. THIS LOW PRESSURE JUST OFF THE COAST WILL
SUPPLY JUST ENOUGH LIFT TO KEEP SHOWERS GOING ACROSS PORTIONS OF
EASTERN MA AND RI. THE HRRR HAD A GOOD HANDLE ON THESE LIGHT
SHOWERS...AND WAS LEANED ON HEAVILY FOR UPDATING THE FORECAST
THIS AFTERNOON. THE GOOD NEWS IS TEMPERATURES ARE ABOVE
FREEZING...SO NOT EXPECTING ANY MORE FREEZING DRIZZLE OR FREEZING
RAIN.
ISOLATED LOW-TOPPED CONVECTION DEVELOPED NEAR THE ENTRANCE TO
NARRAGANSETT BAY. THE MAIN THREAT WILL BE FOR BRIEF TORRENTIAL
RAINFALL. WE DID HAVE A REPORT FROM SOUTH KINGSTOWN RI OF PEA-
SIZED HAIL...A TESTAMENT TO NEARNESS OF COLDER AIR TO THE GROUND.
LATER TONIGHT...THE WEAK OFFSHORE LOW PRESSURE WILL CONTINUE TO
MOVE INTO THE GULF OF MAINE. THIS SHOULD BRING AN END TO MOST OF
THE PRECIPITATION ACROSS SOUTHERN NEW ENGLAND BEFORE CHANGING
PRECIPITATION TYPES BECOME A CONCERN.
LOW-LEVEL MOISTURE SHOULD LEAD TO AREAS OF FOG TONIGHT...
ESPECIALLY AFTER MIDNIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
SOUTHERN NEW ENGLAND IS IN BETWEEN A PAIR OF LOW PRESSURES MONDAY.
THE FIRST WILL BE A LOW PRESSURE MOVING TOWARD THE MARITIMES...THE
OTHER WILL BE A STRONGER LOW PRESSURE OFF THE MID ATLANTIC COAST.
THIS SHOULD MEAN A SLIGHT CHANCE OF SHOWERS TOWARD THE EAST COAST
OF MA DURING THE MORNING...WITH ANOTHER CHANCE OF SHOWERS ACROSS
RI AND SOUTHEAST MA DEVELOPING FROM THE SOUTH DURING LATE
AFTERNOON INTO MONDAY NIGHT. TIMING AND TEMPERATURES INDICATE RAIN
SHOULD BE THE DOMINANT PRECIPITATION TYPE.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS POSSIBLE TUE ACROSS COASTAL AREAS
* DRY AND MILDER WED INTO THU WITH SPOTTY SHOWERS POSSIBLE
* COLD FRONT MAY BRING PERIOD OF PRECIPITATION THU NIGHT-FRI...THEN
COLDER TEMPERATURES RETURN NEXT WEEKEND
OVERVIEW...
UPPER LEVEL PATTERN EVOLVES FROM BROAD TROUGHING TO AN EVENTUAL
CUTOFF H5 LOW BUT WELL E OF NEW ENGLAND TUE-WED. MEDIUM RANGE MODELS
CONTINUE TO SIGNAL LONG WAVE TROUGH DIVING INTO THE WESTERN U.S.
WITH TEMPS RUNNING AT LEAST 20 DEGREES BELOW SEASONAL NORMALS ACROSS
THE PLAINS BY LATE WEEK. THIS WILL TRANSLATE TO A BROAD RIDGE
BUILDING OVER THE EAST AS WELL AS A SURGE OF SOMEWHAT MILDER TEMPS.
WITH TWO LARGE CUTOFF LOWS SPINNING ACROSS CANADA...COLD AIR APPEARS
TO MIGRATE S AND E WHILE UPPER RIDGE BUILDS OFFSHORE LATER FRIDAY
INTO NEXT WEEKEND. SO...AFTER BRIEF WARMUP...APPEARS ANOTHER SURGE
OF COLD AIR WILL START TO WORK INTO THE REGION LATER SAT/NEXT
SUN...FOR NOW.
DETAILS...
TUESDAY...BACK EDGE OF PRECIP LINGER ACROSS COASTAL AREAS AS LOW
PRES PASSES WELL SE OF NANTUCKET DURING THE DAY. HAVE KEPT CHANCE
POPS GOING THERE...THOUGH SHOULD BE ENDING FOR MOST AREAS EXCEPT THE
CAPE AND ISLANDS DURING THE DAY. LEFTOVER CLOUDS SHOULD START
TO CLEAR DURING THE AFTERNOON. TEMPS WILL TOP OFF IN THE 40S.
TUESDAY NIGHT-WEDNESDAY...WEAK HIGH PRES RIDGE STEADILY CROSSES THE
REGION DURING THIS TIMEFRAME. EXPECT OVERNIGHT LOWS IN THE MID 20S
WELL INLAND TO THE MID-UPPER 30S ALONG THE IMMEDIATE COAST. ON
WED...CLOUDS WILL BEGIN TO PUSH E DURING THE AFTERNOON. HIGHS WILL
AGAIN BE IN THE 40S.
WEDNESDAY NIGHT...WARM FRONT APPROACHES WHICH MAY BRING SOME LIGHT
RAIN SHOWERS OR POSSIBLY SOME LIGHT FREEZING RAIN ACROSS S NH/N
CENTRAL AND NW MA TO BEGIN EARLY WED NIGHT. LOWS IN THE UPPER 20S TO
UPPER 30S EARLY WILL RISE THROUGH THE OVERNIGHT.
THURSDAY-FRIDAY...COLD FRONT SLOWLY SLIDES THROUGH THE REGION DURING
THU INTO THU NIGHT AS IT RUNS CLOSE TO PARALLEL TO THE W-SW UPPER
FLOW. THE FRONT APPEARS TO STALL THU NIGHT INTO FRIDAY WITH ANOTHER
WAVE OF LOW PRES MOVING ALONG IT. THIS WILL BRING RENEWED CHANCE FOR
PRECIP. LOOKS LIKE IT WILL MAINLY BE IN THE FORM OF RAIN. MAY SEE
BRIEF PERIOD OF FREEZING RAIN LATE THU NIGHT INTO FRI MORNING OVER
HIGHER TERRAIN OF S NH AS TEMPS TRY TO FALL AT OR SLIGHTLY BELOW
FREEZING.
FRIDAY NIGHT-SUNDAY...MODELS TRY TO MOVE ANOTHER SHORT WAVE IN THE
ELONGATED UPPER FLOW THAT MAY TRY TO FLATTEN OUT AS UPPER CUTOFF
LOWS ACROSS CENTRAL AND EASTERN CANADA PUSH SURGE OF COLD AIR INTO
THE REGION. TIMING IS STILL IN QUESTION...SO CONTINUED LOW
CONFIDENCE WITH THIS PORTION OF THE FORECAST. DOES LOOK LIKE PERIOD
OF PRECIP WILL CONTINUE INTO SAT...BUT MORE QUESTIONS AS TO PTYPE
DURING THE FRI NIGHT INTO EARLY SAT TIMEFRAME. FOR NOW...HAVE TENDED
TO DRY THINGS OUT DURING SAT BUT WILL TURN COLDER ESPECIALLY ON
SUNDAY.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...MODERATE CONFIDENCE IN TAFS.
LOW CONFIDENCE IN EXACT TIMING.
THROUGH 00Z...A MIX OF CONDITIONS WILL PERSIST THROUGH HIS
AFTERNOON...RANGING FROM VFR...TO IFR ACROSS THE MONADNOCKS OF
NH...THE CENTRAL WORCESTER HILLS...AND THE HIGHER TERRAIN OF
NORTHERN CT. LOW LEVEL RH IS STILL RATHER HIGH...SO EXPECTING CIGS
TO CRASH FOR BRIEF PERIOD THIS EVENING...ESPECIALLY ACROSS EASTERN
MA...INCLUDING KBOS.
TONIGHT...ONSHORE FLOW WILL ALLOW FOR VFR/MVFR CIGS TO DROP
OVERNIGHT TO LOW END MVFR/IFR. EXPECTING FOG TO DEVELOP AT THE
USUAL LOCATIONS...CAUSING SOME VSBYS RESTRICTIONS. LIGHT OFFSHORE
WINDS SHOULD DEVELOP...AND SHOULD KEEP MORE WIDESPREAD FOG FROM
DEVELOPING ACROSS EASTERN MA AND RI. SHOULD THESE WINDS NOT
DEVELOP AS EXPECTED...MORE WIDESPREAD FOG SHOULD RESULT. IFR
TOWARD THE COAST...WITH VFR FARTHER INLAND.
TOMORROW...CONDITIONS SLOWLY IMPROVE TO VFR ACROSS ALL AREAS.
PATCHY DRIZZLE TO START THE DAY ACROSS EASTERN MA.
MONDAY NIGHT...MAINLY MVFR TO VFR CONDITIONS. LOWER CONDITIONS
MOST LIKELY TOWARD THE COAST WHERE THE BEST CHANCE FOR A RAIN
SHOWER WILL EXIST.
KBOS TAF...MODERATE CONFIDENCE...MAINLY DUE TO TIMING ISSUES. FOG
COULD BE MORE WIDESPREAD IF OFFSHORE WIND DO NOT DEVELOP AS
STRONGLY AS CURRENT EXPECTATIONS. LOWER VSBYS AND CIGS WOULD
RESULT OTHERWISE. CIGS LESS THAN 1000 FEET CLOSE TO TERMINAL NOW.
HAVE HIGHER CONFIDENCE LOWER CIGS WILL IMPACT KBOS THIS EVENING.
ALSO SPED UP TIMING FOR LOWER CIGS TO ARRIVE.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING.
OUTLOOK...TUESDAY THROUGH FRIDAY...MODERATE CONFIDENCE.
TUESDAY...MAINLY VFR CONDITIONS ACROSS CENTRAL AND WESTERN AREAS.
MVFR CIGS/VSBYS WITH BRIEF IFR CONDITIONS POSSIBLE ALONG COASTAL
AREAS ESPECIALLY THROUGH MIDDAY...THEN SHOULD IMPROVE DURING THE
AFTERNOON. MAINLY VFR TUE NIGHT.
WEDNESDAY...MAINLY VFR DURING THE DAY. MAY SEE MVFR CIGS/VSBYS
DEVELOP FROM W-E WED NIGHT.
WEDNESDAY NIGHT-THURSDAY NIGHT...LOW END VFR CONDITIONS WITH PERIODS
OF MVFR-IFR IN SCT SHOWERS. MAY SEE BRIEF PERIOD OF -FZRA BOTH LATE
WED NIGHT AND THU NIGHT ACROSS HIGHER TERRAIN OF S NH POSSIBLY INTO
N CENTRAL AND NW MA.
FRIDAY...MAINLY MVFR CIGS/VSBYS IN SHOWERS DURING THE DAY. MAY SEE
BRIEF PERIOD OF IFR CONDITIONS FRI NIGHT AS PRECIP BEGINS TO MIX AS
COLDER AIR MOVES IN ACROSS S NH/N MA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.
CONDITIONS WILL BE BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THIS
PERIOD. DRIZZLE AND FOG WILL BE THE MAIN CONCERN TONIGHT INTO
MONDAY...WHICH COULD LOWER VISIBILITIES.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUESDAY...MODERATE TO HIGH CONFIDENCE. OCEAN STORMS PASSES WELL SE
OF NANTUCKET...BUT WILL STILL SEE NE WINDS GUSTING TO 25 KT ACROSS
THE EASTERN OUTER WATERS. SEAS WILL ALSO BUILD...UP TO 5-8 FT MAINLY
OVER THE OUTER WATERS.
WEDNESDAY...WINDS BACK TO NW AND START TO DIMINISH. MAY SEE SOME
GUSTS TO 25 KT. SEAS WILL REMAIN ABOVE SMALL CRAFT CRITERIA...THOUGH
SHOULD SUBSIDE DURING WED NIGHT.
THURSDAY-FRIDAY...EXPECT WINDS BELOW SMALL CRAFT CRITERIA. SEAS MAY
LINGER AROUND 5 FT ON THE OUTER WATERS.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES ARE QUITE HIGH TUESDAY MORNING...WITH AN 11.9
HIGH TIDE IN BOSTON. FORTUNATELY...IT LOOKS LIKE AN OCEAN STORM
WILL INTENSIFY TOO FAR EAST AND TOO LATE FOR A SIGNIFICANT COASTAL
FLOOD EVENT. HOWEVER...THE POTENTIAL FOR SPLASHOVER AND POCKETS
OF VERY MINOR COASTAL FLOODING ACROSS THE EASTERN MA COAST STILL
EXISTS GIVEN THE HIGH ASTRONOMICAL TIDES. IN ADDITION...MINOR
BEACH EROSION IS ALSO A POSSIBILITY DURING THE TUESDAY HIGH TIDE
CYCLES ALONG THE OUTER CAPE OCEAN SIDE AND THE EAST SHORE OF
NANTUCKET.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...BELK/EVT
MARINE...BELK/EVT
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
239 PM EST SUN DEC 1 2013
.SYNOPSIS...
A CLIPPER LOW TODAY WILL BRING A CHANCE OF LIGHT MIXED WINTRY
PRECIPITATION. AN OCEAN STORM WILL LIKELY PASS FAR ENOUGH EAST OF
OUR REGION TO JUST BRING THE RISK FOR A PERIOD OF RAIN SHOWERS MON
NIGHT/TUE...MAINLY ON THE COASTAL PLAIN. RELATIVELY MILD WEATHER
WED/THU WILL BE REPLACED BY MUCH COLDER WEATHER SOMETIME FRI OR
SAT...ALONG WITH THE POTENTIAL FOR A PERIOD OF PRECIPITATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
200 PM UPDATE...
LATEST SURFACE MAP ALREADY SHOWING THE TRANSFER OF ENERGY FROM A
WEAK LOW PRESSURE IN THE LOWER GREAT LAKES TO A LOW PRESSURE OFF
THE MID ATLANTIC COAST. THIS LOW PRESSURE JUST OFF THE COAST WILL
SUPPLY JUST ENOUGH LIFT TO KEEP SHOWERS GOING ACROSS PORTIONS OF
EASTERN MA AND RI. THE HRRR HAD A GOOD HANDLE ON THESE LIGHT
SHOWERS...AND WAS LEANED ON HEAVILY FOR UPDATING THE FORECAST
THIS AFTERNOON. THE GOOD NEWS IS TEMPERATURES ARE ABOVE
FREEZING...SO NOT EXPECTING ANY MORE FREEZING DRIZZLE OR FREEZING
RAIN.
LATER TONIGHT...THE WEAK OFFSHORE LOW PRESSURE WILL CONTINUE TO
MOVE INTO THE GULF OF MAINE. THIS SHOULD BRING AN END TO MOST OF
THE PRECIPITATION ACROSS SOUTHERN NEW ENGLAND BEFORE CHANGING
PRECIPITATION TYPES BECOME A CONCERN.
LOW-LEVEL MOISTURE SHOULD LEAD TO AREAS OF FOG TONIGHT...
ESPECIALLY AFTER MIDNIGHT.
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
SOUTHERN NEW ENGLAND IS IN BETWEEN A PAIR OF LOW PRESSURES MONDAY.
THE FIRST WILL BE A LOW PRESSURE MOVING TOWARD THE MARITIMES...THE
OTHER WILL BE A STRONGER LOW PRESSURE OFF THE MID ATLANTIC COAST.
THIS SHOULD MEAN A SLIGHT CHANCE OF SHOWERS TOWARD THE EAST COAST
OF MA DURING THE MORNING...WITH ANOTHER CHANCE OF SHOWERS ACROSS
RI AND SOUTHEAST MA DEVELOPING FROM THE SOUTH DURING LATE
AFTERNOON INTO MONDAY NIGHT. TIMING AND TEMPERATURES INDICATE RAIN
SHOULD BE THE DOMINANT PRECIPITATION TYPE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* PERIOD OF RAIN SHOWERS POSSIBLE MAINLY COASTAL PLAIN TUE
* MILDER WED/THU WITH JUST THE RISK OF A SPOT SHOWER OR TWO
* TURNING COLDER SOMETIME FRI INTO SAT WITH A PERIOD OF
PRECIPITATION POSSIBLE
DETAILS...
TUESDAY...LATEST MODELS ARE IN FAIRLY GOOD AGREEMENT IN LOW
PRESSURE EMERGING OFF THE CAROLINA COAST AND INTENSIFYING INTO A
STRONG OCEAN STORM. IT APPEARS THOUGH THAT THE SYSTEM WILL TRACK
TOO FAR EAST AND INTENSIFY TOO LATE FOR A SIGNIFICANT IMPACT IN
SOUTHERN NEW ENGLAND. THEREFORE...JUST EXPECT A GLANCING BLOW WITH
THE POTENTIAL FOR A PERIOD OF RAIN SHOWERS MAINLY ALONG THE
COASTAL PLAIN. IF SOME OF THE PRECIPITATION WERE TO REACH INTO THE
DISTANT INTERIOR...IT MAY BE COLD ENOUGH FOR A BIT OF SNOW.
HOWEVER...LATEST GUIDANCE SUGGEST THAT THE STEADY PRECIP MAY BE
CONFINED TO THE COASTAL PLAIN...BUT TOO EARLY TO COMPLETELY RULE
OUT THAT POSSIBILITY. HIGHS SHOULD GENERALLY BE IN THE 40S ON
TUESDAY WITH AN ABUNDANCE OF CLOUDS.
WEDNESDAY AND THURSDAY...
MOST OF THIS TIME WILL PROBABLY END UP DRY...BUT A WEAK SHORTWAVE
MOVING THROUGH IN WESTERLY FLOW ALOFT MAY TRIGGER A FEW SPOT
SHOWERS SOMETIME LATE WED OR THU. RISING HEIGHT FIELDS AHEAD OF A
DIGGING UPPER LEVEL TROUGH IN THE CENTRAL U.S. WILL YIELD
RELATIVELY MILD WEATHER. HIGHS SHOULD GENERALLY BE IN THE 40S TO
LOWER 50S.
FRIDAY AND SATURDAY...
A VERY LOW CONFIDENCE FORECAST OVER THIS TIME. A STRONG COLD
FRONT WILL BE APPROACHING THE REGION...AS A COUPLE WAVES OF LOW
PRESSURE RIDE ALONG IT. DEPENDING ON HOW QUICKLY THE FRONT SAGS
SOUTH AND WHERE WE END UP IN RELATION TO THE WAVES OF LOW
PRESSURE...WILL DETERMINE OUR WEATHER. WE DO KNOW THAT IT WILL
EVENTUALLY TURN COLDER...BUT WHEN THAT OCCURS IS HIGHLY UNCERTAIN.
WE ALSO WILL PROBABLY DEAL WITH A PERIOD OF WET WEATHER. ITS ALSO
NOT OUT OF THE QUESTION THAT SOME OF THE AREA ENDS UP WITH A BIT
OF WINTRY PRECIPITATION AT THE END. THIS WOULD OCCUR IF THE
BOUNDARY HANGS UP TO OUR SOUTH AND ANOTHER WAVE OF LOW PRESSURE
DEVELOPS ON IT. AGAIN THOUGH VERY LOW CONFIDENCE ON HOW THINGS
EVOLVE IN THIS TIME PERIOD.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...MODERATE CONFIDENCE IN TAFS.
LOW CONFIDENCE IN EXACT TIMING.
THROUGH 00Z...A MIX OF CONDITIONS WILL PERSIST THROUGH HIS
AFTERNOON...RANGING FROM VFR...TO IFR ACROSS THE MONADNOCKS OF
NH...THE CENTRAL WORCESTER HILLS...AND THE HIGHER TERRAIN OF
NORTHERN CT.
TONIGHT...ONSHORE FLOW WILL ALLOW FOR VFR/MVFR CIGS TO DROP
OVERNIGHT TO LOW END MVFR/IFR. EXPECTING FOG TO DEVELOP AT THE
USUAL LOCATIONS...CAUSING SOME VSBYS RESTRICTIONS. LIGHT OFFSHORE
WINDS SHOULD DEVELOP...AND SHOULD KEEP MORE WIDESPREAD FOG ACROSS
EASTERN MA AND RI. SHOULD THESE WINDS NOT DEVELOP AS EXPECTED...
MORE WIDESPREAD FOG SHOULD DEVELOP. IFR TOWARD THE COAST...WITH
VFR FARTHER INLAND.
TOMORROW...CONDITIONS SLOWLY IMPROVE TO VFR ACROSS ALL AREAS.
PATCHY DRIZZLE TO START THE DAY ACROSS EASTERN MA.
MONDAY NIGHT...MAINLY MVFR TO VFR CONDITIONS. LOWER CONDITIONS
MOST LIKELY TOWARD THE COAST WHERE THE BEST CHANCE FOR A RAIN
SHOWER WILL EXIST.
KBOS TAF...MODERATE CONFIDENCE...MAINLY DUE TO TIMING ISSUES. FOG
COULD BE MORE WIDESPREAD IF OFFSHORE WIND DO NOT DEVELOP AS
STRONGLY AS CURRENT EXPECTATIONS. LOWER VSBYS AND CIGS WOULD
RESULT OTHERWISE.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING.
OUTLOOK...TUESDAY THROUGH THURSDAY...MODERATE CONFIDENCE
TUESDAY...MAINLY MVFR TO VFR CONDITIONS OVER THIS TIME PERIOD.
LOWER CONDITIONS MOST LIKELY ALONG THE COASTAL PLAIN WHERE THE
BEST CHANCE FOR A PERIOD OF RAIN SHOWER WILL EXIST.
WEDNESDAY AND THURSDAY...MAINLY VFR BUT A PERIOD OF MVFR CONDITIONS
ARE POSSIBLE ESPECIALLY LATER THU OR THU NIGHT.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...HIGH CONFIDENCE.
CONDITIONS WILL BE BELOW SCA...HOWEVER THERE MAY BE AN HOUR OR
TWO WHERE SEAS INCREASE TO 5FT ACROSS THE SOUTHERN WATERS. BECAUSE
OF THE LOW CONFIDENCE LEFT IT OUT FOR NOW. OTHERWISE WINDS WILL
DECREASE THROUGH TONIGHT ALLOWING FOR SEAS TO RELAX. DRIZZLE AND
FOG WILL BE THE MAIN CONCERN TONIGHT AND INTO MONDAY...WHICH
COULD LOWER VISIBILITIES.
OUTLOOK...TUESDAY THROUGH THURSDAY...
TUESDAY...MODERATE TO HIGH CONFIDENCE. OCEAN STORM WILL PASS WELL
EAST OF THE REGION. PRESSURE GRADIENT SHOULD STILL INCREASE ENOUGH
FOR A PERIOD OF NORTHERLY SCA WIND GUSTS AND SCA SEAS ON TUESDAY.
WEDNESDAY AND THURSDAY...MODERATE TO HIGH CONFIDENCE. SOME UPPER
LEVEL RIDGING SHOULD KEEPS WINDS BELOW SCA THRESHOLDS.
HOWEVER...SWELL WILL RESULT IN SCA SEAS AT TIMES ACROSS THE SOUTHERN
AND EASTERN ATLANTIC WATERS.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES ARE QUITE HIGH TUESDAY MORNING...WITH AN 11.9
HIGH TIDE IN BOSTON. FORTUNATELY...IT LOOKS LIKE THE OCEAN STORM
WILL INTENSIFY TOO FAR EAST AND TOO LATE FOR A SIGNIFICANT COASTAL
FLOOD EVENT. HOWEVER...STILL THE POTENTIAL FOR SPLASH OVER AND
POCKETS OF VERY MINOR COASTAL FLOODING ACROSS THE EASTERN MA COAST
GIVEN THE HIGH ASTRONOMICAL TIDES. IN ADDITION...MINOR BEACH
EROSION IS ALSO A POSSIBILITY DURING THE TUESDAY HIGH TIDE CYCLES
ALONG THE OUTER CAPE OCEAN SIDE AND THE EAST SHORE OF NANTUCKET.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/FRANK
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...FRANK
AVIATION...BELK/FRANK
MARINE...BELK/FRANK
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
237 PM EST SUN DEC 1 2013
.DISCUSSION...
CURRENT THROUGH MONDAY...MSAS AND RUC13 SURFACE ANALYSIS STILL
SHOWING THAT A COASTAL TROUGH WAS SITUATED OFF THE VOLUSIA AND NORTH
BREVARD COASTS...AND ON TOP OF THE GULF STREAM. RADAR TRENDS SHOW
THAT THE SHOWERS EMBEDDED IN THE FLOW TO THE EAST OF THE TROUGH
AXIS WERE NOT MAKING IT VERY FAR WEST OF THE TROUGH AXIS WHILE
NORTHERLY WINDS ALONG THE COAST INTERACTING WITH EASTERLY WINDS
JUST OFF THE SURFACE FROM CAPE CANAVERAL SOUTH WERE PRODUCING
PERSISTENT LINES OF MODERATE TO OCCASIONALLY HEAVY RAIN FROM VERO
BEACH SOUTH.
STORM REPORTS INDICATED LOCALIZED AMOUNTS OF 3 TO 4 INCHES OR
MORE IN THE VERO BEACH AREA SINCE DAYBREAK WITH MORE RAIN MOVING
IN OFF THE OCEAN. VISIBLE SATELLITE IMAGES WERE SHOWING SEA FOG
ALONG THE VOLUSIA COUNTY COAST AND NEARSHORE WATERS. A RECENT
REPORT CALLED INTO THE OFFICE FROM PEOPLE ON THE INTRACOASTAL
WATERWAY IN THE PONCE INLET AREA INDICATED VISIBILITIES DOWN TO
LESS THAN HALF A MILE.
THE COASTAL TROUGH WL BEGIN TO LIFT NORTHEAST AFTER MIDNIGHT.
THIS WILL ALLOW THE WINDS TO SHIFT BACK TO THE NORTHWEST LATE
OVERNIGHT AND REMAIN OUT OF THE NORTHWEST AND WEST MONDAY AS THE
TROUGH DEEPENS INTO A LOW OFF THE GEORGIA SOUTH CAROLINA COAST.
MODELS DEPICT A WEAK FRONTAL TROUGH/BOUNDARY ASSOCIATED WITH THE
FORMING LOW MOVING DOWN THE PENINSULA MONDAY AND CLEARING EAST
CENTRAL FLORIDA MONDAY NIGHT. GUIDANCE NOT SHOWING MUCH PRECIP WITH
THE BOUNDARY OR A DRYING TREND WITH THE NORTHWEST FLOW BEHIND THE
DEPARTING BOUNDARY.
LOWS MONDAY MORNING EXPECTED TO BE IN THE MID AND UPPER 50S. THE
NORTHWEST FLOW WILL KEEP MONDAYS HIGHS IN THE LOW AND MIDDLE 70S.
THE RAIN CONFINED TO THE COAST AFTER MIDNIGHT AND OVER THE COASTAL
WATERS MONDAY.
A SECONDARY FRONTAL PSG TUE NIGHT SHOULD ONLY BRING INCRSD
CLOUDS/SPRINKLES. WILL HOLD POPS BELOW 20 PERCENT. TEMPS WILL
BEGIN A VERY SLOW/GRADUAL MODIFICATION TUE.
WED-SAT...(PREVIOUS DISC) LARGE ANTICYCLONE EXPANDS FROM THE
YUCATAN PENINSULA TO SOUTH FLORIDA TO NEAR BERMUDA DURING THIS
PERIOD. MEANWHILE...A SURFACE HIGH OVER THE WESTERN ATLANTIC
REMAINS NEARLY STATIONARY WITH ASSOCIATED RIDGE EXTENDING TO
CENTRAL FLORIDA. RESULTANT PATTERN WILL FAVOR A LIGHT SE/S FLOW
WITH NO LARGE SCALE WX IMPACTS. SOME PERIODS OF SHALLOW/ENHANCED
MOISTURE MAY EVENTUALLY PROMPT A SMALL CHANCE OF MARINE/COASTAL
SHOWERS...BUT PROSPECT TOO ILL-DEFINED AT THIS TIME TO INSERT
MENTIONABLE POPS. MAX TEMPS WILL GRADUALLY CLIMB TO LOWER 80S WITH
MINS LOWER/MID 60S BY THU...CONTINUING INTO THE WEEKEND.
EXCEPTIONS WILL BE ALONG COAST NORTH OF THE CAPE WHERE ONSHORE
FLOW ACROSS COLDER SHELF WATERS WILL MODIFY HIGHS TO UPPER
70S...AND COASTAL AREAS SOUTH OF VERO BEACH WHERE WARMER WATERS
WILL MODIFY LOWS TO THE UPPER 60S/NEAR 70.
&&
.AVIATION...
CURRENT-OVERNIGHT...VFR CEILINGS AND VISIBILITIES SANFORD ORLANDO
KISSIMMEE AND WEST. PREVAILING MVFR WITH TEMPO IFR AND LIFR
CONDITIONS ALONG THE COAST KOMN-JUPITER INLET. SCT-BKN FL010 OR BELOW
06Z-14Z THEN VFR AFTER 15Z AS THE NORTHWEST WINDS CLEARS OUT THE AIR
MASS NORTH TO SOUTH.
&&
.MARINE...
CURRENT THROUGH MONDAY...THE TROUGH OFF VOLUSIA AND NORTH BREVARD
COAST WAS PRODUCING NORTHERLY WINDS OVER THE NEARSHORE...THE
INTRACOASTAL WATERS...THE HALIFAX RIVER IN VOLUSIA AND THE INDIAN
RIVER LAGOON FROM BREVARD TO MARTIN COUNTY. BUOYS AND SURFACE
OBSERVATION ALONG THE COAST FROM SAINT AUGUSTINE TO JUPITER INLET
BACK THIS UP BY RECORDING INDICATING NORTHERLY WINDS IN THE 10 TO 15
KNOT RANGE. SEAS HEIGHTS BEING REPORTED WERE 7 FEET OR LESS.
WINDS START BACKING TO THE NORTHWEST OVERNIGHT AS THE COASTAL TROUGH
BEGINS TO MOVE OFF TO THE NORTHEAST. THE SEA FOG ALONG THE VOLUSIA
AND NORTH BREVARD COAST SHOULD DISSIPATE DURING THE EVENING. THE LOW
CLOUDS AND RAIN ALONG THE COAST FROM SOUTH BREVARD TO JUPITER INLET
WILL MOST LIKELY PERSIST AS LONG AS THE WIND STAYS NORTH AND NORTH
NORTHWEST. ONCE THE WINDS STEADY UP OUT OF THE NORTHWEST THE PRECIP
AT THE COAST AND JUST OFF THE BEACHES WILL END AND BECOME ISOLATED
AWAY FROM THE COAST.
TUE-THU...(PREV DISC) RATHER LIGHT/VARIABLE FLOW TUE THEN SE/S
BELOW 15 KT THROUGH THU AS SURFACE HIGH BUILDS OFFSHORE AND RIDGE
EXTENDS TO CENTRAL PENINSULA. SEAS WILL SUBSIDE TO NEAR 2 FEET
CLOSE TO THE COAST AND 3-4 FEET WITHIN THE GULF STREAM TUE-THU AS
RIDGE LIES OVERHEAD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 57 73 50 74 / 20 10 0 10
MCO 59 75 53 77 / 10 10 0 10
MLB 60 74 54 74 / 20 10 0 10
VRB 59 76 53 76 / 20 10 0 10
LEE 56 73 51 76 / 10 10 0 10
SFB 58 74 52 76 / 20 10 0 10
ORL 59 74 54 76 / 10 10 0 10
FPR 60 76 53 75 / 20 10 0 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST THIS
AFTERNOON FOR WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD
COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN
INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-WATERS FROM
VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM
OFFSHORE.
&&
$$
SHORT TERM...WIMMER
LONG TERM....PENDERGRAST
AREA FORECAST DISCUSSION
NWS MIAMI FL
104 PM EST SUN DEC 1 2013
.AVIATION...
SCATTERED SHOWERS WILL CONTINUE TO IMPACT THE EAST COAST TERMINALS
THROUGH THE LATE AFTERNOON HOURS BEFORE DIMINISHING. THESE WILL BE
CAPABLE OF PRODUCING SUB VFR CIGS/VSBYS PERIODICALLY...ESPECIALLY
IN THE HEAVIER SHOWERS THAT MOVE THROUGH. ANOTHER ROUND OF FOG
AROUND THE APF TERMINAL WILL REMAIN POSSIBLE LATE TONIGHT INTO
MONDAY MORNING AHEAD OF AN APPROACHING FRONTAL BOUNDARY. LIGHT
NORTHWEST WINDS WILL FOLLOW THIS BOUNDARY THROUGH THE DAY TOMORROW
WITH MOSTLY DRY CONDITIONS EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 951 AM EST SUN DEC 1 2013/
UPDATE...
THE SHERIFF OFFICES AND THE OBSERVATIONS OVER THE INTERIOR AND
WEST COAST METRO AREAS OF SOUTH FLORIDA ARE NOW REPORTING
VISIBILITIES TO BE BETWEEN 1 TO 3 MILES IN THE FOG. SO WILL LET
THE DENSE FOG ADVISORY EXPIRED AT 10 AM EDT THIS MORNING FOR THE
INTERIOR AND WEST COAST METRO AREAS.
THE FOG SHOULD CONTINUE TO BURN OFF THROUGH NOON TIME ALLOWING FOR
THE SKIES TO BECOME PARTLY CLOUDY BY THIS AFTERNOON ALONG WITH DRY
WEATHER. SO WILL SHOW A TREND OF CLEARING SKIES ALONG WITH DRY
CONDITIONS FOR THE INTERIOR AND WEST COAST METRO AREAS.
FOR THE EAST COAST METRO AREAS...THERE HAS BEEN SOME ISOLATED
SHOWERS WORKING INTO THIS AREA FROM THE ATLANTIC WATERS. THE
ISOLATED SHOWERS WILL CONTINUE TO WORK INTO THE EAST COAST METRO
AREAS THROUGH THE AFTERNOON HOURS ON THE EASTERLY WIND FLOW. SO
WILL KEEP A SLIGHT CHANCE OF SHOWERS IN PLACE FOR THE EAST COAST
METRO AREAS THROUGH THIS AFTERNOON.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED.
UPDATE...54/BNB
PREV DISCUSSION... /ISSUED 642 AM EST SUN DEC 1 2013/
AVIATION...
REDUCED VSBYS IN FOG ARE MAINLY IMPACTING THE APF SITE THIS
MORNING AND INLAND OF THE EAST COAST TERMINALS. THIS SHOULD BURN
OFF BY OR BETWEEN 8-9AM WITH VFR CONDITIONS RETURNING. THE BEST
CHANCE OF SHOWERS WILL BE ALONG THE EAST COAST TODAY...WHICH WILL
BE CAPABLE OF PRODUCING PERIODS OF REDUCED CIGS/VSBYS THROUGH THE
DAY. WINDS WILL REMAIN OUT OF THE NORTHEAST AND INCREASE TO AROUND
10 KT THROUGH THE LATE MORNING AND AFTERNOON HOURS. ALTHOUGH
CONFIDENCE REMAINS TOO LOW...WINDS COULD SHIFT TO THE WNW AT APF
DUE A GULF COAST SEA BREEZE THROUGH THE AFTERNOON PERIOD. WILL
MONITOR THIS AND UPDATE IF NEEDED.
PREV DISCUSSION... /ISSUED 319 AM EST SUN DEC 1 2013/
DISCUSSION...
HIGH PRESSURE TO THE NORTH CONTINUES TO BRING NORTHEASTERLY FLOW
TO SOUTH FLORIDA. HOWEVER, THE HIGH WILL BEGIN TO WEAKEN TODAY,
ALLOWING THE WINDS TO BECOME LIGHTER. THERE IS STILL A FEW SHOWERS
OVER THE ATLANTIC WATERS. CURRENTLY, THEY ARE NOT IMPACTING THE
CWA, BUT STILL HAVE A SLIGHT CHANCE IN THE FORECAST. THE HRRR DOES
SHOW SOME ISOLATED SHOWERS OVER THE ATLANTIC COAST METRO AREAS
THIS AFTERNOON, SO BROUGHT SLIGHT CHANCE POPS SOMEWHAT MORE WEST.
MODELS STILL SHOWING A VERY WEAK FRONT PUSHING SOUTH THROUGH SOUTH
FLORIDA TOMORROW, BUT LOOKS BARELY DISCERNIBLE IN THE MODELS. GFS
HAS HIGH PRESSURE BUILDING OVER THE FLORIDA PENINSULA BY 00Z
TUESDAY WITH NO PRECIPITATION AT ALL. THE ECMWF IS SIMILAR, BUT
ABOUT 6 HOURS SLOWER WITH MORE BROAD WEAK HIGH PRESSURE BUILDING.
EITHER WAY. THE BEST EVIDENCE OF THIS FRONT WILL LIKELY BE A WEAK
WINDS SHIFT TOMORROW. BUT, LEFT A SLIGHT CHANCE OF SHOWERS ACROSS
THE CWA FOR THE AFTERNOON HOURS. BUT, GIVEN CURRENT MODEL RUNS,
COULD DEFINITELY SEE THIS BEING PULLED OUT OF THE FORECAST LATER
TODAY.
AFTER TOMORROW, IT IS HIGH PRESSURE FOR THE REMAINDER OF THE
FORECAST PERIOD. THE AIR MASS WILL WARM VERY SLIGHTLY THROUGH THE
WEEK, WITH PERHAPS A FEW LIGHT COASTAL SHOWERS POSSIBLE,
ESPECIALLY IN THE OVERNIGHT HOURS.
AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY
MORNING HOURS. HOWEVER...AN AREA OF CLOUDINESS AND EMBEDDED
SHOWERS IS MOVING WESTWARD INTO THE LOCAL ATLANTIC WATERS AND A FEW
SHOWERS COULD IMPACT THE EAST COAST TERMINALS FROM TIME TO TIME.
ONLY PASSING SHOWERS EXPECTED BUT WILL AMEND IF ANY VIS/CEILING
RESTRICTIONS OCCUR BUT NOT EXPECTED. WINDS ACROSS THE EAST COAST
TERMINALS STARTING TO BECOME LIGHT AND VARIABLE WITH AN OFF SHORE
DRAINAGE FLOW BEGINNING.
MARINE...
HIGH PRESSURE TO THE NORTH WILL WEAKEN TODAY, BUT STILL KEEP
EASTERLY FLOW OVER THE COASTAL WATERS. THE WEAKER WINDS WILL
RESULT IN SEAS CONTINUING TO SUBSIDE TODAY. GIVEN THIS ALL
ADVISORIES AND CAUTION STATEMENTS HAVE BEEN CANCELLED. THERE IS A
SLIGHT CHANCE OF SHOWERS OVER THE NEXT COUPLE OF DAYS AS A VERY
WEAK COLD FRONT SLIDES ACROSS THE AREA TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 62 78 58 79 / 10 - - -
FORT LAUDERDALE 63 78 62 79 / 10 - - -
MIAMI 64 80 62 79 / 10 - - -
NAPLES 60 75 59 78 / - - - -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
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...
18Z UPDATE...
WINDS HAVE BEEN VERY SLOW TO SHIFT OVER TODAY BUT FINALLY STARTING
TO SEE SOME WESTERLY COMPONENT SHOW UP IN THE OBSERVATIONS AND
WILL CARRY AS PREVAILING AT ONSET OF THIS TAF SET. SOUTHEAST
CORNER OF FORECAST AREA INCLUDING MCN THE ONLY ONE HOLDING ONTO
MVFR CIGS BUT DIFFICULT TO DETERMINE EXTENT GIVEN MASKING CIRRUS.
FOR THE FORECAST...EXPECT MVFR TO REEMERGE MON MORNING BUT PERHAPS
A FEW HOURS EARLIER THAN PREVIOUS FORECAST. NOW LOOKING AT AROUND
15Z AT ATL FOR MVFR AND -RA TO DEVELOP. ANOTHER SYSTEM WILL MOVE
ACROSS MONDAY NIGHT AND MAY BRING ANOTHER CHANCE OF -RA BUT JUST
OUTSIDE THIS TAF PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON RA CHANCES AND MVFR TIMING.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.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...DEESE
LONG TERM....TDP
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
144 PM CST SUN DEC 1 2013
.DISCUSSION...
302 AM CST
TODAY...
LOW PRESSURE IS SKIRTING EAST ACROSS THE CENTRAL GREAT LAKES WITH A
TRAILING COLD FRONT SAGGING SOUTH ACROSS THE CENTRAL PART OF THE CWA
EARLY THIS MORNING. A FEW RADAR RETURNS TO OUR NORTH MAINLY
ASSOCIATED WITH MID LEVEL CLOUD COVER...AND PRECIP IS NOT MAKING ITS
WAY TO THE SURFACE...NOR IS IT EXPECTED TO AS THE FRONT CONTINUES TO
SLIP ACROSS THE CWA THROUGH THE MORNING. STRATUS DECK IS EVIDENT ON
IR IMAGERY BUILDING SOUTH BEHIND THE FRONT. EXPECT THESE LOWER
CLOUDS TO BUILD ACROSS THE FORECAST AREA LATER THIS MORNING THEN
REMAIN IN PLACE THROUGH THE DAY AND TONIGHT. WEAK HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE AREA TONIGHT...THOUGH MODEL RH FIELDS
SHOW LITTLE IF ANY DISSIPATION OF THE STRATUS DECK. ASSUMING WE STAY
CLOUDY OVERNIGHT...TEMPERATURES SHOULD STAY PROPPED UP INTO THE
UPPER 20S TO LOW 30S DESPITE WINDS LIKELY GOING VERY LIGHT OR
CALM. HOWEVER...IF WE DO SEE CLEARING...WILL HAVE TO MAKE HEFTY
CHANGES TO OVERNIGHT LOWS WHICH COULD FALL 10+ DEGREES MORE THAN
CURRENTLY FORECAST UNDER A STRONG RADIATIONAL COOLING SETUP.
MONDAY...
UPPER LOW DIGS FROM BRITISH COLUMBIA INTO THE PACIFIC NORTHWEST THIS
PERIOD WHILE A LEAD WAVE KICKS EAST ACROSS THE NORTHERN PLAINS WITH
SURFACE LOW UNDERGOING CYCLOGENESIS. ECMWF NO LONGER ADVERTISING
SHORTWAVE EARLY MONDAY...WHICH IS IN LINE WITH OTHER MODEL SOLUTIONS
THUS PULLED MENTION OF POPS MONDAY. BY MONDAY EVENING...H85
BAROCLINIC ZONE SETS UP FROM THE DAKOTAS INTO THE MID MISSISSIPPI
VALLEY WITH A ZONE OF ISENTROPIC ASCENT FOCUSED JUST TO OUR WEST.
STILL UNCERTAIN HOW FAR EAST THE PRECIP WILL EXTEND...BUT BEST
CHANCES WILL BE IN THE NORTHWESTERN PORTIONS OF THE CWA AROUND
ROCKFORD. PRECIP MAY START OFF AS RAIN SNOW MIX...BUT SHOULD
TRANSITION TO ALL RAIN AS THE WARM AIR CONTINUES TO PUSH NORTHWARD.
TEMPERATURES MAY RISE OVERNIGHT MONDAY NIGHT ACROSS PORTIONS IF NOT
ALL OF THE CWA DEPENDING ON HOW QUICKLY THE WARM FRONT LIFTS ACROSS
THE AREA.
TUESDAY THROUGH WEDNESDAY...
LONGWAVE TROUGH CONTINUES TO DEEPEN ACROSS THE WESTERN CONUS WITH
DOWNSTREAM AMPLIFICATION OF THE RIDGE ACROSS THE CENTRAL CONUS.
SURFACE LOW PROGGED TO TRACK FROM THE DAKOTAS INTO THE NORTHERN
LAKES REGION THROUGH THE PERIOD WITH STRONG WARM ADVECTION AHEAD OF
THE LOW WARMING H85 TEMPS TO AROUND 7-8C TUE/WED. 01/00Z EMCWF
ACTUALLY THROWING A WRENCH INTO PREVIOUS FORECAST THINKING FOR
THIS SYSTEM MIDWEEK...TRENDING MUCH FASTER AND MORE IN LINE WITH
THE GFS. NOT QUITE READY TO BITE OFF ON THIS COMPLETELY AS OFTEN
TIMES WITH CLOSED UPPER LOWS SLOWER MODEL SOLUTIONS TEND TO BE
BETTER...AND WOULD NOT BE SURPRISED TO SEE THE GFS AND ECMWF TREND
SLOWER IN THE NEXT COUPLE DAYS. TEMPERATURES ON WEDNESDAY A BIT
TRICKY WITH BIG BUST POTENTIAL. SLIGHTLY FASTER OR SLOWER FROPA
WILL RESULT IN A 15-20 DEGREE RANGE OF POSSIBLE TEMPERATURES.
ECMWF CONTINUES TO BE AGGRESSIVE WITH TEMPERATURES AHEAD OF THE
FRONT...SUGGESTING MID TO UPPER 50S ACROSS MUCH OF THE EASTERN
HALF OF THE CWA EVEN WITH FASTER FROPA. THE GEM...WHICH IS SLOWER
THAN THE GFS/ECMWF NOW SUGGESTING LOW TO MID 60S WEDNESDAY.
TRENDED SLIGHTLY WARMER ACROSS THE EASTERN CWA WHICH WILL HAVE THE
BEST LIKELIHOOD OF SEEING FULL WARMTH AHEAD OF THE FRONT.
THURSDAY THROUGH SATURDAY...
BY THURSDAY...H85 TEMPS SHOULD QUICKLY FALL TO AROUND -10C...THEN
FURTHER COOL TO AROUND -15C TO -18C SATURDAY AS A COLD ARCTIC
AIRMASS TRICKLES INTO THE REGION. BOTH THE GFS AND ECMWF INDICATE
A SERIES OF WAVES LIFTING NORTHEAST ALONG THE FRONT CAUSING PRECIP
NORTH OF THE FRONT AND POSSIBLY IMPACTING EASTERN PORTIONS OF THE
CWA THURSDAY AND THURSDAY NIGHT. OTHERWISE...STRONG HIGH PRESSURE
OVER THE NORTHERN PLAINS WILL BUILD SOUTHEAST WITH RIDGING IN
PLACE FRIDAY INTO THE WEEKEND BRINGING MORE SETTLED AND COLD
WEATHER...WITH HIGHS IN THE TEENS TO LOW 20S...AND SINGLE DIGIT
LOWS FRIDAY AND SATURDAY.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS WILL BE AROUND THROUGH AT LEAST MID AFTN.
* MFR CIGS RETURN OVERNIGHT.
JEE
//DISCUSSION...UPDATED 18Z...
MAJOR CONCERN IS MVFR CLOUDS FORMING OVER THE LAKE AND MOVING OVER
NE IL. CLOUD DEVELOPMENT AND COVER REALLY BLOSSOMED AFTER 16Z SO
ADJUSTED TAFS TO INCLUDE MVFR CIGS THROUGH MID AFTN. A MID LEVEL
CLOUD DECK IS OV IOWA AND SLOWLY ADVANCING EAST. THINKING THE MVFR
CLOUDS WILL DISSIPATE AS THE MID LEVEL DECK MOVES OVERHEAD. WINDS
ALSO TURN MORE NORTHERLY AT THIS TIME WHICH WOULD REDUCE THE
ADVECTION OF LAKE CLOUDS OVER LAND. THERE IS A CHANCE THAT THE
MVFR CLOUDS MAY LINGER A BIT LONGER THAN CURRENTLY FCST THIS AFTN.
LIGHT WINDS BCM LIGHT AND VARIABLE OVERNIGHT...WITH A NW COMPONENT
AT ORD AND MDW AND EAST AT RFD. THE LIGHT FLOW AND LOW LEVEL
MOISTURE SUGGEST MVFR CIGS REDEVELOP. GUIDANCE TRIES TO FORM FOG
AS WELL...BUT THINKING CLOUD COVER WILL TRUMP FOG. VRB WINDS
CONTINUE INTO THE AM WITH MVFR CIGS SCATTERING OUT. WINDS TURN SE
ON THE BACKSIDE OF THE HIGH TOMORROW WITH SPEEDS ARND 10KT.
THERE IS A SLIGHT CHANCE OF PRECIP IN THE LATE AFTN BUT GUIDANCE
CONTINUES TO PULL FORCING AND MAJORITY OF PRECIP NORTH INTO
WISCONSIN. THE PRECIP WOULD BE A WINTRY MIX OR ALL RAIN...BUT IT
IS SO SLIGHT THAT IT WAS LEFT OUT OF THE TAFS FOR NOW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN CIGS THROUGH 23Z.
* MEDIUM-HIGH CONFIDENCE IN CIG FCST AFT 23Z.
* HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR PROBABLE. CHANCE OF -RASN.
TUESDAY INTO WEDNESDAY...MVFR CIGS POSSIBLE. CHANCE OF RAIN
ESPECIALLY WEDNESDAY.
THURSDAY...SLGT CHANCE OF SHSN WITH MVFR VSBY. OTHERWISE MAINLY
VFR.
FRIDAY AND SATURDAY...MAINLY VFR.
RATZER
&&
.MARINE...
252 AM CST
MAIN MARINE FORECAST CONCERNS FOCUS ON DEVELOPMENT OF STRONG LOW
PRESSURE OVER THE PLAINS MONDAY-TUESDAY...WHICH THEN IS EXPECTED TO
LIFT NORTHEAST ACROSS THE NORTHERN LAKES ON WEDNESDAY. THERE
CONTINUES TO BE SOME SPREAD IN MODEL SOLUTIONS WITH THE DEPTH...
TRACK AND TIMING OF THE LOW.
WEAK LOW PRESSURE WAS OVER LOWER MICHIGAN STATE EARLY THIS
MORNING...WITH A COLD FRONT TRAILING ACROSS SOUTHERN LAKE MICHIGAN.
THE LOW WILL CONTINUE TO TRACK EAST ACROSS THE EASTERN LAKES THROUGH
THIS EVENING...WITH THE FRONT PUSHING SOUTHEAST OF LAKE MICHIGAN
LATER THIS MORNING. WEAK HIGH PRESSURE RIDGING WILL THEN MOVE ACROSS
THE WESTERN LAKES LATER TODAY/TONIGHT...DRIFTING SLOWLY OFF TO THE
EAST ON MONDAY. WITH A RELATIVELY WEAK PUSH TO THE FRONT TODAY...
WINDS WILL SHIFT TO THE NORTH AT GENERALLY LESS THAN 15 KT.
FORECAST MODELS CONTINUE TO DEPICT AN AREA OF LOW PRESSURE
DEVELOPING ACROSS THE HIGH PLAINS BY EARLY MONDAY...WHICH THEN
DEEPENS ACROSS THE CENTRAL PLAINS MONDAY NIGHT. VARIOUS MODEL
SOLUTIONS CONTINUE TO SHOW DIFFERENCES WITH THE EVOLUTION OF THIS
LOW THROUGH MID-WEEK...THOUGH THERE IS SOME CONSENSUS IN LIFTING THE
LOW NORTHEAST ACROSS THE NORTHERN GREAT LAKES WEDNESDAY. GENERALLY
HAVE CONTINUED TO FOLLOW THE SLOWER SOLUTIONS OF THE ECMWF/GEM/UKMET
WITH THIS SYSTEM...THOUGH WILL HAVE TO SEE SOME OF THE DIFFERENCES
IRONED OUT BEFORE CONFIDENCE INCREASES IN DETAILS OF STRENGTH/TRACK
AND TIMING. IT DOES APPEAR THAT THE POTENTIAL EXISTS FOR SOUTHEAST
30-35 KT WINDS AHEAD OF THE LOW LATE TUESDAY INTO WEDNESDAY...AND
WEST GALES LATER WEDNESDAY INTO THURSDAY WITH THE PASSAGE OF THIS
STORM. STILL 3-4 DAYS OUT SO WILL NOT HAVE ANY HEADLINES...THOUGH
WILL MENTION POSSIBLE GALES IN FORECAST FOR THIS PERIOD.
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:
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WWW.TWITTER.COM/NWSCHICAGO
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Area Forecast Discussion
National Weather Service Lincoln IL
1201 PM CST Sun Dec 1 2013
.DISCUSSION...
ISSUED 1027 AM CST Sun Dec 1 2013
Another weak cold front drifting southward over the FA this
morning with north winds behind it, although light. Morning warm
up very much ahead of diurnal curve yet again. Have adjusted the
forecast temps up a degree or two, but warm up will be countered
by weak cold air mixing in behind the boundary. Dryness of the
column underestimated and cloud cover not materializing. Have
adjusted the sky grids as well in the short term. Update out
momentarily, to include a removal of the fog wording from this morning.
&&
.AVIATION...
ISSUED 1157 AM CST Sun Dec 1 2013
Similar issues to yesterdays forecast. VFR in the short term,
light and variable winds. Trouble with late tonight and into
tomorrow is the model mishandling of the RH in general. Going with
more of a trend forecast, mid/high level clouds thin and allow
some radiational cooling to set up another fog scenario. Starting
at 3SM, but increasing dwpts at sfc and cooling in the overnight
may result in a drop to IFR for the morning vis. Conservative for
now, but will watch afternoon xovers as well.
HJS
&&
.PREV DISCUSSION...
ISSUED 248 AM CST Sun Dec 1 2013
Main forecast challenge focuses on departing storm system for the
middle and end of the week...and whether or not it will produce
any wintry precipitation across central Illinois.
SHORT TERM...Today through Tuesday
Weak cold front currently across northern Illinois will sink
southward today, eventually becoming stationary along the Ohio
River by evening. Front will be accompanied by little in the way
of sensible weather other than a shift in the wind. Low-level
moisture seen on IR/fog satellite across southeast Missouri/far
southern Illinois is progged by HRRR to remain mostly south of
I-70 today, while patchy mid-level clouds over Iowa into far
northern Illinois stay mostly north of the area. End result will
be mostly sunny skies until later this afternoon when clouds begin
to approach from the northwest. High temperatures will be bit
cooler behind the cold front, ranging from the middle 40s far
northwest around Galesburg to the lower 50s south of I-70.
Boundary will remain in place along the Ohio River through Monday,
before lifting back northward in response to rising upper-level
heights Monday night into Tuesday. Models continue to show a
subtle short-wave rippling eastward out of the Plains late Sunday
night into Monday that could interact with the front to produce
scattered light showers. Forecast soundings remain dry at
low-levels: however, think forcing will be strong enough to
mention a slight chance for showers on Monday. As front lifts
northward, rain chances will shift into the southern Great Lakes
on Tuesday. Brisk southerly winds south of the departing warm
front will bring much warmer air into the region, with Tuesday
afternoon highs reaching the lower to middle 50s.
LONG TERM...Wednesday through Saturday
Forecast becomes more challenging in the extended, as upper low
currently over northwest British Columbia drops southward and
carves a deep trough across the western CONUS by the middle of the
week. Downstream ridging will place the Midwest/Great Lakes in a
broad southwesterly flow pattern, leading to increased precip
chances Wednesday into Thursday. Models have been struggling with
the evolution of a surface low pressure system and its associated
cold front for the past several runs: however, the 00z DEC 1 run
seems to be coming into better agreement. While GFS remains a fast
outlier, the latest ECMWF has sped up the front quite a bit.
Following an ECMWF/GEM consensus yields FROPA across central
Illinois on Wednesday followed by sharply colder conditions for
the end of the week. Main question will be how much precip will
hold back in the colder airmass Thursday and possibly Friday.
Previous runs of the ECMWF had featured quite a bit of wintry
precip Thursday night into Friday as a secondary wave of low
pressure tracked along the departing front. While it still shows the
potential for wintry precip, it has backed off/shifted E/SE with
its latest solution. GEM seems to be the most consistent model
over the past couple of days, so have trended toward its solution.
With cold front passing on Wednesday, will mention a chance for
showers. After FROPA, precip will largely shut off Wednesday
night, before a wave of low pressure tracking from the lower
Mississippi River Valley into the Ohio River Valley brings a
renewed round of precip primarily across the eastern half of the
KILX CWA on Thursday/Thursday night. Have focused highest POPs
along/east of I-57 for both Thursday and Thursday night, tapering
down to just slight chances further west along/west of the
Illinois River. Precip type during the day Thursday will be rain
across the east, with a rain/snow mix along I-55 and mostly light
snow in the Illinois River Valley. As deeper layer of cold air
arrives, precip will change to light snow across the board
Thursday night, with a light accumulation possible. After that,
will hold on to low chance POPs for snow across the far E/SE on
Friday, although if trends continue, these may need to be dropped
entirely. Main weather story for the end of the week will be the
much colder conditions. Highs by Friday and Saturday will only be
in the 20s, with overnight lows in the single digits and teens.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1153 AM CST SUN DEC 1 2013
.DISCUSSION...
302 AM CST
TODAY...
LOW PRESSURE IS SKIRTING EAST ACROSS THE CENTRAL GREAT LAKES WITH A
TRAILING COLD FRONT SAGGING SOUTH ACROSS THE CENTRAL PART OF THE CWA
EARLY THIS MORNING. A FEW RADAR RETURNS TO OUR NORTH MAINLY
ASSOCIATED WITH MID LEVEL CLOUD COVER...AND PRECIP IS NOT MAKING ITS
WAY TO THE SURFACE...NOR IS IT EXPECTED TO AS THE FRONT CONTINUES TO
SLIP ACROSS THE CWA THROUGH THE MORNING. STRATUS DECK IS EVIDENT ON
IR IMAGERY BUILDING SOUTH BEHIND THE FRONT. EXPECT THESE LOWER
CLOUDS TO BUILD ACROSS THE FORECAST AREA LATER THIS MORNING THEN
REMAIN IN PLACE THROUGH THE DAY AND TONIGHT. WEAK HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE AREA TONIGHT...THOUGH MODEL RH FIELDS
SHOW LITTLE IF ANY DISSIPATION OF THE STRATUS DECK. ASSUMING WE STAY
CLOUDY OVERNIGHT...TEMPERATURES SHOULD STAY PROPPED UP INTO THE
UPPER 20S TO LOW 30S DESPITE WINDS LIKELY GOING VERY LIGHT OR
CALM. HOWEVER...IF WE DO SEE CLEARING...WILL HAVE TO MAKE HEFTY
CHANGES TO OVERNIGHT LOWS WHICH COULD FALL 10+ DEGREES MORE THAN
CURRENTLY FORECAST UNDER A STRONG RADIATIONAL COOLING SETUP.
MONDAY...
UPPER LOW DIGS FROM BRITISH COLUMBIA INTO THE PACIFIC NORTHWEST THIS
PERIOD WHILE A LEAD WAVE KICKS EAST ACROSS THE NORTHERN PLAINS WITH
SURFACE LOW UNDERGOING CYCLOGENESIS. ECMWF NO LONGER ADVERTISING
SHORTWAVE EARLY MONDAY...WHICH IS IN LINE WITH OTHER MODEL SOLUTIONS
THUS PULLED MENTION OF POPS MONDAY. BY MONDAY EVENING...H85
BAROCLINIC ZONE SETS UP FROM THE DAKOTAS INTO THE MID MISSISSIPPI
VALLEY WITH A ZONE OF ISENTROPIC ASCENT FOCUSED JUST TO OUR WEST.
STILL UNCERTAIN HOW FAR EAST THE PRECIP WILL EXTEND...BUT BEST
CHANCES WILL BE IN THE NORTHWESTERN PORTIONS OF THE CWA AROUND
ROCKFORD. PRECIP MAY START OFF AS RAIN SNOW MIX...BUT SHOULD
TRANSITION TO ALL RAIN AS THE WARM AIR CONTINUES TO PUSH NORTHWARD.
TEMPERATURES MAY RISE OVERNIGHT MONDAY NIGHT ACROSS PORTIONS IF NOT
ALL OF THE CWA DEPENDING ON HOW QUICKLY THE WARM FRONT LIFTS ACROSS
THE AREA.
TUESDAY THROUGH WEDNESDAY...
LONGWAVE TROUGH CONTINUES TO DEEPEN ACROSS THE WESTERN CONUS WITH
DOWNSTREAM AMPLIFICATION OF THE RIDGE ACROSS THE CENTRAL CONUS.
SURFACE LOW PROGGED TO TRACK FROM THE DAKOTAS INTO THE NORTHERN
LAKES REGION THROUGH THE PERIOD WITH STRONG WARM ADVECTION AHEAD OF
THE LOW WARMING H85 TEMPS TO AROUND 7-8C TUE/WED. 01/00Z EMCWF
ACTUALLY THROWING A WRENCH INTO PREVIOUS FORECAST THINKING FOR
THIS SYSTEM MIDWEEK...TRENDING MUCH FASTER AND MORE IN LINE WITH
THE GFS. NOT QUITE READY TO BITE OFF ON THIS COMPLETELY AS OFTEN
TIMES WITH CLOSED UPPER LOWS SLOWER MODEL SOLUTIONS TEND TO BE
BETTER...AND WOULD NOT BE SURPRISED TO SEE THE GFS AND ECMWF TREND
SLOWER IN THE NEXT COUPLE DAYS. TEMPERATURES ON WEDNESDAY A BIT
TRICKY WITH BIG BUST POTENTIAL. SLIGHTLY FASTER OR SLOWER FROPA
WILL RESULT IN A 15-20 DEGREE RANGE OF POSSIBLE TEMPERATURES.
ECMWF CONTINUES TO BE AGGRESSIVE WITH TEMPERATURES AHEAD OF THE
FRONT...SUGGESTING MID TO UPPER 50S ACROSS MUCH OF THE EASTERN
HALF OF THE CWA EVEN WITH FASTER FROPA. THE GEM...WHICH IS SLOWER
THAN THE GFS/ECMWF NOW SUGGESTING LOW TO MID 60S WEDNESDAY.
TRENDED SLIGHTLY WARMER ACROSS THE EASTERN CWA WHICH WILL HAVE THE
BEST LIKELIHOOD OF SEEING FULL WARMTH AHEAD OF THE FRONT.
THURSDAY THROUGH SATURDAY...
BY THURSDAY...H85 TEMPS SHOULD QUICKLY FALL TO AROUND -10C...THEN
FURTHER COOL TO AROUND -15C TO -18C SATURDAY AS A COLD ARCTIC
AIRMASS TRICKLES INTO THE REGION. BOTH THE GFS AND ECMWF INDICATE
A SERIES OF WAVES LIFTING NORTHEAST ALONG THE FRONT CAUSING PRECIP
NORTH OF THE FRONT AND POSSIBLY IMPACTING EASTERN PORTIONS OF THE
CWA THURSDAY AND THURSDAY NIGHT. OTHERWISE...STRONG HIGH PRESSURE
OVER THE NORTHERN PLAINS WILL BUILD SOUTHEAST WITH RIDGING IN
PLACE FRIDAY INTO THE WEEKEND BRINGING MORE SETTLED AND COLD
WEATHER...WITH HIGHS IN THE TEENS TO LOW 20S...AND SINGLE DIGIT
LOWS FRIDAY AND SATURDAY.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS WILL BE AROUND THROUGH AT LEAST MID AFTN...PSBLY
LONGER.
* MFR CIGS RETURN OVERNIGHT.
JEE
//DISCUSSION...UPDATED 18Z...
MAJOR CONCERN IS MVFR CLOUDS FORMING OVER THE LAKE AND MOVING OVER
NE IL. CLOUD DEVELOPMENT AND COVER REALLY BLOSSOMED AFTER 16Z SO
ADJUSTED TAFS TO INCLUDE MVFR CIGS THROUGH MID AFTN. A MID LEVEL
CLOUD DECK IS OV IOWA AND SLOWLY ADVANCING EAST. THINKING THE MVFR
CLOUDS WILL DISSIPATE AS THE MID LEVEL DECK MOVES OVERHEAD. WINDS
ALSO TURN MORE NORTHERLY AT THIS TIME WHICH WOULD REDUCE THE
ADVECTION OF LAKE CLOUDS OVER LAND. THERE IS A CHANCE THAT THE
MVFR CLOUDS MAY LINGER A BIT LONGER THAN CURRENTLY FCST THIS AFTN.
LIGHT WINDS BCM LIGHT AND VARIABLE OVERNIGHT...WITH A NW COMPONENT
AT ORD AND MDW AND EAST AT RFD. THE LIGHT FLOW AND LOW LEVEL
MOISTURE SUGGEST MVFR CIGS REDEVELOP. GUIDANCE TRIES TO FORM FOG
AS WELL...BUT THINKING CLOUD COVER WILL TRUMP FOG. VRB WINDS
CONTINUE INTO THE AM WITH MVFR CIGS SCATTERING OUT. WINDS TURN SE
ON THE BACKSIDE OF THE HIGH TOMORROW WITH SPEEDS ARND 10KT.
THERE IS A SLIGHT CHANCE OF PRECIP IN THE LATE AFTN BUT GUIDANCE
CONTINUES TO PULL FORCING AND MAJORITY OF PRECIP NORTH INTO
WISCONSIN. THE PRECIP WOULD BE A WINTRY MIX OR ALL RAIN...BUT IT
IS SO SLIGHT THAT IT WAS LEFT OUT OF THE TAFS FOR NOW.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIGS THROUGH 22Z...MEDIUM CONFIDENCE IN MVFR
CIGS SCATTERING OUT THIS AFTN.
* HIGH CONFIDENCE IN ALL OTHER FCST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR PROBABLE. CHANCE OF -RASN.
TUESDAY INTO WEDNESDAY...MVFR CIGS POSSIBLE. CHANCE OF RAIN
ESPECIALLY WEDNESDAY.
THURSDAY...SLGT CHANCE OF SHSN WITH MVFR VSBY. OTHERWISE MAINLY
VFR.
FRIDAY AND SATURDAY...MAINLY VFR.
RATZER
&&
.MARINE...
252 AM CST
MAIN MARINE FORECAST CONCERNS FOCUS ON DEVELOPMENT OF STRONG LOW
PRESSURE OVER THE PLAINS MONDAY-TUESDAY...WHICH THEN IS EXPECTED TO
LIFT NORTHEAST ACROSS THE NORTHERN LAKES ON WEDNESDAY. THERE
CONTINUES TO BE SOME SPREAD IN MODEL SOLUTIONS WITH THE DEPTH...
TRACK AND TIMING OF THE LOW.
WEAK LOW PRESSURE WAS OVER LOWER MICHIGAN STATE EARLY THIS
MORNING...WITH A COLD FRONT TRAILING ACROSS SOUTHERN LAKE MICHIGAN.
THE LOW WILL CONTINUE TO TRACK EAST ACROSS THE EASTERN LAKES THROUGH
THIS EVENING...WITH THE FRONT PUSHING SOUTHEAST OF LAKE MICHIGAN
LATER THIS MORNING. WEAK HIGH PRESSURE RIDGING WILL THEN MOVE ACROSS
THE WESTERN LAKES LATER TODAY/TONIGHT...DRIFTING SLOWLY OFF TO THE
EAST ON MONDAY. WITH A RELATIVELY WEAK PUSH TO THE FRONT TODAY...
WINDS WILL SHIFT TO THE NORTH AT GENERALLY LESS THAN 15 KT.
FORECAST MODELS CONTINUE TO DEPICT AN AREA OF LOW PRESSURE
DEVELOPING ACROSS THE HIGH PLAINS BY EARLY MONDAY...WHICH THEN
DEEPENS ACROSS THE CENTRAL PLAINS MONDAY NIGHT. VARIOUS MODEL
SOLUTIONS CONTINUE TO SHOW DIFFERENCES WITH THE EVOLUTION OF THIS
LOW THROUGH MID-WEEK...THOUGH THERE IS SOME CONSENSUS IN LIFTING THE
LOW NORTHEAST ACROSS THE NORTHERN GREAT LAKES WEDNESDAY. GENERALLY
HAVE CONTINUED TO FOLLOW THE SLOWER SOLUTIONS OF THE ECMWF/GEM/UKMET
WITH THIS SYSTEM...THOUGH WILL HAVE TO SEE SOME OF THE DIFFERENCES
IRONED OUT BEFORE CONFIDENCE INCREASES IN DETAILS OF STRENGTH/TRACK
AND TIMING. IT DOES APPEAR THAT THE POTENTIAL EXISTS FOR SOUTHEAST
30-35 KT WINDS AHEAD OF THE LOW LATE TUESDAY INTO WEDNESDAY...AND
WEST GALES LATER WEDNESDAY INTO THURSDAY WITH THE PASSAGE OF THIS
STORM. STILL 3-4 DAYS OUT SO WILL NOT HAVE ANY HEADLINES...THOUGH
WILL MENTION POSSIBLE GALES IN FORECAST FOR THIS PERIOD.
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
1038 AM CST Sun Dec 1 2013
.DISCUSSION...
ISSUED 1027 AM CST Sun Dec 1 2013
Another weak cold front drifting southward over the FA this
morning with north winds behind it, although light. Morning warm
up very much ahead of diurnal curve yet again. Have adjusted the
forecast temps up a degree or two, but warm up will be countered
by weak cold air mixing in behind the boundary. Dryness of the
column underestimated and cloud cover not materializing. Have
adjusted the sky grids as well in the short term. Update out
momentarily, to include a removal of the fog wording from this morning.
HJS
&&
.AVIATION...
ISSUED 535 AM CST Sun Dec 1 2013
Will see a few hours of MVFR vsbys in fog early this morning, then
VFR conditions are expected into this evening, before another threat
for some lower vsbys in fog late tonight. A weak cold front was
pushing across the forecast area early this morning with winds
ahead of the front light southwesterly, and light northwest to north
winds were reported behind the boundary. forecast soundings and
time-height cross sections indicate other than some sct-bkn cirrus
at times today, not much in the way of significant cloud cover
expected until this evening when a weak weather system well out to
our west spreads clouds into our area. Cig heights look to be
from 8000-1000 feet AGL later this evening. Due to the very light
wind regime and despite the expected cloud cover tonight, we do
expect some light fog to develop after 06z over most of the area
with short range ensembles suggesting areas around I-74 seeing
the higher probabilities for lower vsbys due to the fog. For now,
will bring vsbys down to 4-5sm in br late tonight.
Smith
&&
.PREV DISCUSSION...
ISSUED 248 AM CST Sun Dec 1 2013
Main forecast challenge focuses on departing storm system for the
middle and end of the week...and whether or not it will produce
any wintry precipitation across central Illinois.
SHORT TERM...Today through Tuesday
Weak cold front currently across northern Illinois will sink
southward today, eventually becoming stationary along the Ohio
River by evening. Front will be accompanied by little in the way
of sensible weather other than a shift in the wind. Low-level
moisture seen on IR/fog satellite across southeast Missouri/far
southern Illinois is progged by HRRR to remain mostly south of
I-70 today, while patchy mid-level clouds over Iowa into far
northern Illinois stay mostly north of the area. End result will
be mostly sunny skies until later this afternoon when clouds begin
to approach from the northwest. High temperatures will be bit
cooler behind the cold front, ranging from the middle 40s far
northwest around Galesburg to the lower 50s south of I-70.
Boundary will remain in place along the Ohio River through Monday,
before lifting back northward in response to rising upper-level
heights Monday night into Tuesday. Models continue to show a
subtle short-wave rippling eastward out of the Plains late Sunday
night into Monday that could interact with the front to produce
scattered light showers. Forecast soundings remain dry at
low-levels: however, think forcing will be strong enough to
mention a slight chance for showers on Monday. As front lifts
northward, rain chances will shift into the southern Great Lakes
on Tuesday. Brisk southerly winds south of the departing warm
front will bring much warmer air into the region, with Tuesday
afternoon highs reaching the lower to middle 50s.
LONG TERM...Wednesday through Saturday
Forecast becomes more challenging in the extended, as upper low
currently over northwest British Columbia drops southward and
carves a deep trough across the western CONUS by the middle of the
week. Downstream ridging will place the Midwest/Great Lakes in a
broad southwesterly flow pattern, leading to increased precip
chances Wednesday into Thursday. Models have been struggling with
the evolution of a surface low pressure system and its associated
cold front for the past several runs: however, the 00z DEC 1 run
seems to be coming into better agreement. While GFS remains a fast
outlier, the latest ECMWF has sped up the front quite a bit.
Following an ECMWF/GEM consensus yields FROPA across central
Illinois on Wednesday followed by sharply colder conditions for
the end of the week. Main question will be how much precip will
hold back in the colder airmass Thursday and possibly Friday.
Previous runs of the ECMWF had featured quite a bit of wintry
precip Thursday night into Friday as a secondary wave of low
pressure tracked along the departing front. While it still shows the
potential for wintry precip, it has backed off/shifted E/SE with
its latest solution. GEM seems to be the most consistent model
over the past couple of days, so have trended toward its solution.
With cold front passing on Wednesday, will mention a chance for
showers. After FROPA, precip will largely shut off Wednesday
night, before a wave of low pressure tracking from the lower
Mississippi River Valley into the Ohio River Valley brings a
renewed round of precip primarily across the eastern half of the
KILX CWA on Thursday/Thursday night. Have focused highest POPs
along/east of I-57 for both Thursday and Thursday night, tapering
down to just slight chances further west along/west of the
Illinois River. Precip type during the day Thursday will be rain
across the east, with a rain/snow mix along I-55 and mostly light
snow in the Illinois River Valley. As deeper layer of cold air
arrives, precip will change to light snow across the board
Thursday night, with a light accumulation possible. After that,
will hold on to low chance POPs for snow across the far E/SE on
Friday, although if trends continue, these may need to be dropped
entirely. Main weather story for the end of the week will be the
much colder conditions. Highs by Friday and Saturday will only be
in the 20s, with overnight lows in the single digits and teens.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
244 PM EST SUN DEC 1 2013
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 329 AM EST SUN DEC 1 2013
A WEAK COLD FRONT WILL MOVE INTO THE REGION FROM THE NORTH LATER
TODAY...EVENTUALLY STALLING OUT NEAR THE OHIO RIVER EARLY MONDAY
BEFORE RETURNING NORTH AS A WARM FRONT. CLOUDS WILL INCREASE TODAY
AND TONIGHT...WITH A FEW RAIN SHOWERS DEVELOP ON MONDAY AS THE FRONT
LIFTS BACK NORTH. STRONG LOW PRESSURE WILL TRACK INTO THE GREAT
LAKES BY LATE WEDNESDAY...WITH A TRAILING COLD FRONT CROSSING
THROUGH THE OHIO VALLEY INTO WEDNESDAY NIGHT AND THURSDAY AND
BRINGING RAIN TO THE REGION. MUCH COLDER AIR WILL SPILL INTO CENTRAL
INDIANA BEHIND THE FRONT...WITH THE POTENTIAL FOR PRECIPITATION TO
END AS SNOW LATE WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1005 AM EST SUN DEC 1 2013
EXTENSIVE AREA OF STRATUS WAS ALONG AND SOUTH OF A VINCENNES TO
GREENSBURG LINE WHILE MOSTLY CLEAR CONDITIONS WERE TO THE NORTH.
HOWEVER AN AREA OF HIGH CLOUDS WAS SPREADING INTO OUR FAR NORTH.
A WEAK AND DIFFUSE COLD FRONT WILL MOVE SOUTH ACROSS OUR REGION AND
STALL OVER SOUTH CENTRAL SECTIONS BY THIS EVENING.
THE MAIN CHANGES TO THIS FORECAST WILL BE TO REDUCE CLOUD COVER AS
STRATUS TO OUR SOUTH HAS SHOWN NO PROGRESSION NORTHWARD AND RUC
SOUNDINGS INDICATE THIS COULD BREAK UP LATER TODAY. EXPECT MOST
AREAS NORTH AND CENTRAL TO START OUT MOSTLY SUNNY WITH PARTLY CLOUDY
CONDITIONS ALL AREAS LATE TODAY.
GIVEN THAT THERE WILL BE MORE SUNSHINE THAN PREVIOUSLY EXPECTED AND
BASED ON RUC 2 METER TEMPERATURES...WILL RAISE HIGH TEMPERATURES
TODAY ABOUT 3 DEGREES THAN WHAT PREVIOUSLY FORECASTED.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 329 AM EST SUN DEC 1 2013
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES WITH THE BOUNDARY IN THE
REGION LATE TONIGHT INTO EARLY TUESDAY.
THE FRONT WILL BECOME NEARLY STATIONARY ACROSS THE REGION TONIGHT
INTO EARLY MONDAY AS A BROADER WAVE ALOFT TRACKS OUT OF THE CENTRAL
PLAINS AND INTO THE OHIO AND TENNESSEE VALLEYS BY MONDAY MORNING.
MODEL SOUNDINGS INDICATING THE DEVELOPMENT OF A SHARP BUT SHALLOW
INVERSION IN THE LOWEST 1-2KFT OVERNIGHT WITH THE LIKELIHOOD OF A
LOW STRATUS DECK BECOMING WELL ESTABLISHED. HOWEVER WITH DRIER AIR
PRESENT FURTHER UP THROUGH THE BOUNDARY LAYER...THINK THE MOIST
LAYER WILL REMAIN TOO SHALLOW TO SUPPORT ANY
PRECIP/DRIZZLE/SPRINKLES OVERNIGHT...AND HAVE REMOVED PRECIP
CHANCES THROUGH DAYBREAK MONDAY.
BEST CHANCE FOR A FEW RAIN SHOWERS LIKELY COMES MONDAY WITH SLIGHTLY
BETTER FORCING ALOFT COURTESY OF THE AFOREMENTIONED UPPER WAVE AND
PRESENCE OF DEEPER MOISTURE. LOWER LEVELS SHOULD WARM ENOUGH TO
ALLOW PRECIP TO FALL AS ALL RAIN OVER FAR NORTHERN COUNTIES MONDAY
MORNING. RAINFALL AMOUNTS WILL BE ONLY A FEW HUNDREDTHS AT BEST AND
THE SPARSE NATURE OF THE RAIN SHOWERS WILL MEAN SOME LOCATIONS
PROBABLY SEE NO PRECIP AT ALL. WILL MAINTAIN ONLY LOW CHANCE POPS
INTO MONDAY EVENING.
THE FRONT WILL LIFT NORTH OF THE REGION LATE MONDAY NIGHT IN
RESPONSE TO LOW PRESSURE EJECTING OUT OF THE PACIFIC NORTHWEST AND
INTO THE NORTHERN PLAINS BY TUESDAY MORNING. GUIDANCE CONTINUING TO
VARY ON THE HANDLING OF THE SHARP POLAR VORTEX DIVING THROUGH THE
NORTHERN ROCKIES AND THE OVERALL COMPLEX NATURE OF THE UPPER LEVEL
FLOW. ONE TREND NOTED OVER THE LAST FEW MODEL RUNS HOWEVER IS A
GENERAL CONSENSUS TOWARDS A FASTER EASTWARD PROGRESSION TO THE
SURFACE WAVE AND ASSOCIATED COLD FRONT. THE OP GFS IS MOST
PROGRESSIVE AND HAS SUPPORT FROM ITS ENSEMBLE MEMBERS...BUT APPEARS
TO DAMPEN DOWNSTREAM UPPER RIDGING TOO QUICKLY. PREFER THE GROWING
CONSENSUS PRESENTED BY THE OTHER MODELS WITH THE COLD FRONT QUICKLY
APPROACHING THE MISSISSIPPI VALLEY BY WEDNESDAY MORNING. COULD SEE
RAIN SHOWERS DEVELOP AS EARLY AS TUESDAY NIGHT AS A LOW LEVEL JET
MOVES INTO THE OHIO VALLEY.
TEMPS...UNDERCUT AGGRESSIVE MOS GUIDANCE OVERALL FOR MONDAY HIGHS
WITH PRESENCE OF CLOUDS AND PRECIP LIKELY LIMITING WARMING. THE
EXPANSION OF STRONG WARM ADVECTION SOUTH OF THE WARM FRONT ON
TUESDAY SETTING THE STAGE FOR A MILD DAY EVEN DESPITE EXPECTED CLOUD
COVER. MOS AGAIN LOOKED SOMEWHAT AGGRESSIVE...BUT A SEVERAL DEGREE
BUMP IN TEMPS IS WARRANTED WITH THE ENTIRE AREA INTO THE MID/UPPER
50S. CLOSER TO THE WARMER MAVMOS TONIGHT WITH CLOUDS...THEN NEAR
MOS FOR LOWS MONDAY/TUESDAY NIGHTS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 244 PM EST SUN DEC 1 2013
PLENTY OF UNCERTAINTY ON HOW FAST COLD AIR WILL ARRIVE INTO THE AREA
DURING THE EARLY PART OF THE LONG TERM. LATEST TREND HAS BEEN FOR A
QUICKER ARRIVAL...ALTHOUGH A VERY QUICK LOOK AT THE 12Z ECMWF SHOWS
THAT IT HAS DECIDED TO BE A LITTLE SLOWER ONCE AGAIN.
SINCE PREVIOUS FORECAST WAS SO WARM DUE TO SLOWER TIMING...DECIDED
TO GO A LITTLE COOLER THAN ALLBLEND EARLY IN THE EXTENDED. OTHERWISE
GENERALLY STAYED WITH ALLBLEND.
A COUPLE OF WAVES OF LOW PRESSURE WILL RIDE ALONG A FRONT TO OUR
EAST DURING THE FIRST HALF OF THE LONG TERM. WITH THE EXPECTED
THERMAL PROFILES...EXPECT A MIX OF RAIN AND SNOW THURSDAY WITH
MAINLY SNOW ON FRIDAY. COULD BE SOME LOW ACCUMULATIONS OF SNOW.
AS STATED EARLIER THOUGH...UNCERTAINTY IS HIGH SO FORECAST COULD
CHANGE SIGNIFICANTLY DEPENDING ON SPEED OF COLD AIR AND WHERE FRONT
ENDS UP.
SECOND HALF OF LONG TERM LOOKS COLD AND DRY AS ARCTIC AIR SETTLES
IN.
&&
.AVIATION /DISCUSSION FOR THE 011800Z TAF ISSUANCE/...
ISSUED AT 1150 AM EST SUN DEC 1 2013
VFR CONDITIONS THIS AFTERNOON WILL GIVE WAY TO MVFR OVERNIGHT.
COLD FRONT IS MOVING INTO CENTRAL INDIANA NOW AND WILL SHIFT WINDS
TO WEST THEN NORTHWEST THROUGH THE AFTERNOON. WIND SPEEDS WILL BE
LESS THAN 10KT. LOOKS LIKE MAINLY MID CLOUD WILL BE ASSOCIATED WITH
THE FRONT.
UNCERTAINTY INCREASES FOR THE EVENING INTO THE OVERNIGHT PERIOD.
FRONT WILL STALL OUT JUST SOUTH OF THE TAF SITES ALLOWING MOISTURE
TO BEGIN TO POOL ALONG IT. THIS SHOULD EVENTUALLY CREATE SOME FOG
AND MVFR CEILINGS. TIMING AND COVERAGE IS UNCERTAIN SO FOR NOW KEPT
AROUND 08Z AS START TIME FOR LOWER CONDITIONS.
LOWER CONDITIONS SHOULD PERSIST THROUGH MONDAY MORNING WITH FRONT
REMAINING IN THE AREA.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...JH
SHORT TERM...RYAN
LONG TERM....50
AVIATION...50
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FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1150 AM EST SUN DEC 1 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 329 AM EST SUN DEC 1 2013
A WEAK COLD FRONT WILL MOVE INTO THE REGION FROM THE NORTH LATER
TODAY...EVENTUALLY STALLING OUT NEAR THE OHIO RIVER EARLY MONDAY
BEFORE RETURNING NORTH AS A WARM FRONT. CLOUDS WILL INCREASE TODAY
AND TONIGHT...WITH A FEW RAIN SHOWERS DEVELOP ON MONDAY AS THE FRONT
LIFTS BACK NORTH. STRONG LOW PRESSURE WILL TRACK INTO THE GREAT
LAKES BY LATE WEDNESDAY...WITH A TRAILING COLD FRONT CROSSING
THROUGH THE OHIO VALLEY INTO WEDNESDAY NIGHT AND THURSDAY AND
BRINGING RAIN TO THE REGION. MUCH COLDER AIR WILL SPILL INTO CENTRAL
INDIANA BEHIND THE FRONT...WITH THE POTENTIAL FOR PRECIPITATION TO
END AS SNOW LATE WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1005 AM EST SUN DEC 1 2013
EXTENSIVE AREA OF STRATUS WAS ALONG AND SOUTH OF A VINCENNES TO
GREENSBURG LINE WHILE MOSTLY CLEAR CONDITIONS WERE TO THE NORTH.
HOWEVER AN AREA OF HIGH CLOUDS WAS SPREADING INTO OUR FAR NORTH.
A WEAK AND DIFFUSE COLD FRONT WILL MOVE SOUTH ACROSS OUR REGION AND
STALL OVER SOUTH CENTRAL SECTIONS BY THIS EVENING.
THE MAIN CHANGES TO THIS FORECAST WILL BE TO REDUCE CLOUD COVER AS
STRATUS TO OUR SOUTH HAS SHOWN NO PROGRESSION NORTHWARD AND RUC
SOUNDINGS INDICATE THIS COULD BREAK UP LATER TODAY. EXPECT MOST
AREAS NORTH AND CENTRAL TO START OUT MOSTLY SUNNY WITH PARTLY CLOUDY
CONDITIONS ALL AREAS LATE TODAY.
GIVEN THAT THERE WILL BE MORE SUNSHINE THAN PREVIOUSLY EXPECTED AND
BASED ON RUC 2 METER TEMPERATURES...WILL RAISE HIGH TEMPERATURES
TODAY ABOUT 3 DEGREES THAN WHAT PREVIOUSLY FORECASTED.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 329 AM EST SUN DEC 1 2013
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES WITH THE BOUNDARY IN THE
REGION LATE TONIGHT INTO EARLY TUESDAY.
THE FRONT WILL BECOME NEARLY STATIONARY ACROSS THE REGION TONIGHT
INTO EARLY MONDAY AS A BROADER WAVE ALOFT TRACKS OUT OF THE CENTRAL
PLAINS AND INTO THE OHIO AND TENNESSEE VALLEYS BY MONDAY MORNING.
MODEL SOUNDINGS INDICATING THE DEVELOPMENT OF A SHARP BUT SHALLOW
INVERSION IN THE LOWEST 1-2KFT OVERNIGHT WITH THE LIKELIHOOD OF A
LOW STRATUS DECK BECOMING WELL ESTABLISHED. HOWEVER WITH DRIER AIR
PRESENT FURTHER UP THROUGH THE BOUNDARY LAYER...THINK THE MOIST
LAYER WILL REMAIN TOO SHALLOW TO SUPPORT ANY
PRECIP/DRIZZLE/SPRINKLES OVERNIGHT...AND HAVE REMOVED PRECIP
CHANCES THROUGH DAYBREAK MONDAY.
BEST CHANCE FOR A FEW RAIN SHOWERS LIKELY COMES MONDAY WITH SLIGHTLY
BETTER FORCING ALOFT COURTESY OF THE AFOREMENTIONED UPPER WAVE AND
PRESENCE OF DEEPER MOISTURE. LOWER LEVELS SHOULD WARM ENOUGH TO
ALLOW PRECIP TO FALL AS ALL RAIN OVER FAR NORTHERN COUNTIES MONDAY
MORNING. RAINFALL AMOUNTS WILL BE ONLY A FEW HUNDREDTHS AT BEST AND
THE SPARSE NATURE OF THE RAIN SHOWERS WILL MEAN SOME LOCATIONS
PROBABLY SEE NO PRECIP AT ALL. WILL MAINTAIN ONLY LOW CHANCE POPS
INTO MONDAY EVENING.
THE FRONT WILL LIFT NORTH OF THE REGION LATE MONDAY NIGHT IN
RESPONSE TO LOW PRESSURE EJECTING OUT OF THE PACIFIC NORTHWEST AND
INTO THE NORTHERN PLAINS BY TUESDAY MORNING. GUIDANCE CONTINUING TO
VARY ON THE HANDLING OF THE SHARP POLAR VORTEX DIVING THROUGH THE
NORTHERN ROCKIES AND THE OVERALL COMPLEX NATURE OF THE UPPER LEVEL
FLOW. ONE TREND NOTED OVER THE LAST FEW MODEL RUNS HOWEVER IS A
GENERAL CONSENSUS TOWARDS A FASTER EASTWARD PROGRESSION TO THE
SURFACE WAVE AND ASSOCIATED COLD FRONT. THE OP GFS IS MOST
PROGRESSIVE AND HAS SUPPORT FROM ITS ENSEMBLE MEMBERS...BUT APPEARS
TO DAMPEN DOWNSTREAM UPPER RIDGING TOO QUICKLY. PREFER THE GROWING
CONSENSUS PRESENTED BY THE OTHER MODELS WITH THE COLD FRONT QUICKLY
APPROACHING THE MISSISSIPPI VALLEY BY WEDNESDAY MORNING. COULD SEE
RAIN SHOWERS DEVELOP AS EARLY AS TUESDAY NIGHT AS A LOW LEVEL JET
MOVES INTO THE OHIO VALLEY.
TEMPS...UNDERCUT AGGRESSIVE MOS GUIDANCE OVERALL FOR MONDAY HIGHS
WITH PRESENCE OF CLOUDS AND PRECIP LIKELY LIMITING WARMING. THE
EXPANSION OF STRONG WARM ADVECTION SOUTH OF THE WARM FRONT ON
TUESDAY SETTING THE STAGE FOR A MILD DAY EVEN DESPITE EXPECTED CLOUD
COVER. MOS AGAIN LOOKED SOMEWHAT AGGRESSIVE...BUT A SEVERAL DEGREE
BUMP IN TEMPS IS WARRANTED WITH THE ENTIRE AREA INTO THE MID/UPPER
50S. CLOSER TO THE WARMER MAVMOS TONIGHT WITH CLOUDS...THEN NEAR
MOS FOR LOWS MONDAY/TUESDAY NIGHTS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 329 AM EST SUN DEC 1 2013
ENSEMBLES ARE IN GOOD AGREEMENT ON THE EVOLVING WEATHER PATTERN
LATER THIS WEEK. MEAN UPPER TROUGHING EXPECTED FROM THE NORTHERN
PLAINS BACK INTO THE SOUTHWEST...WHILE UPPER RIDGING DEVELOPS OVER
THE SOUTHEAST. 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 WEDNESDAY. WILL KEEP SOME
RAIN CHANCES IN THE FORECAST FOR WEDNESDAY AS THE UPPER DISTURBANCE
MOVES THROUGH.
AFTER THAT...FORECAST BECOMES MORE MUDDLED AS THE POTENTIAL EXISTS
FOR WAVES TO EJECT OUT OF THE WESTERN TROUGH. AT THIS POINT...THE
ENSEMBLES DON/T INDICATE ANY MAJOR LOW PRESSURE SYSTEMS...BUT RATHER
STABLE TYPE SURFACE WAVES RIPPLING ALONG A PRIMARY FRONTAL ZONE
LOCATED OVER THE TENNESSEE VALLEY. ENSEMBLES SEEM TO KEY IN ON ONE
WAVE MOVING THROUGH AROUND THURSDAY INTO EARLY FRIDAY...AND ANOTHER
JUST AFTER THIS FORECAST PERIOD. ALTHOUGH AN ARGUMENT CAN BE MADE
FOR AT LEAST SOME PRECIPITATION THREAT EVERY DAY...FOR NOW WILL KEEP
THE POPS RESTRICTED TO THURSDAY AND FRIDAY. APPEARS THERE IS
POTENTIAL FOR SOME LIGHT SNOW ACCUMULATIONS THURSDAY NIGHT INTO
FRIDAY MORNING.
&&
.AVIATION /DISCUSSION FOR THE 011800Z TAF ISSUANCE/...
ISSUED AT 1150 AM EST SUN DEC 1 2013
VFR CONDITIONS THIS AFTERNOON WILL GIVE WAY TO MVFR OVERNIGHT.
COLD FRONT IS MOVING INTO CENTRAL INDIANA NOW AND WILL SHIFT WINDS
TO WEST THEN NORTHWEST THROUGH THE AFTERNOON. WIND SPEEDS WILL BE
LESS THAN 10KT. LOOKS LIKE MAINLY MID CLOUD WILL BE ASSOCIATED WITH
THE FRONT.
UNCERTAINTY INCREASES FOR THE EVENING INTO THE OVERNIGHT PERIOD.
FRONT WILL STALL OUT JUST SOUTH OF THE TAF SITES ALLOWING MOISTURE
TO BEGIN TO POOL ALONG IT. THIS SHOULD EVENTUALLY CREATE SOME FOG
AND MVFR CEILINGS. TIMING AND COVERAGE IS UNCERTAIN SO FOR NOW KEPT
AROUND 08Z AS START TIME FOR LOWER CONDITIONS.
LOWER CONDITIONS SHOULD PERSIST THROUGH MONDAY MORNING WITH FRONT
REMAINING IN THE AREA.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...JH
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS JACKSON KY
351 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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1229 PM EST SUN DEC 1 2013
RETURN FLOW BETWEEN HIGH PRESSURE TO OUR SOUTHEAST AND A WEAK
BOUNDARY CURRENTLY WORKING INTO THE OH VALLEY WILL CONTINUE THROUGH
THE PERIOD...AND MOISTURE WILL CONTINUE TO BE GRADUALLY TRANSPORTED
NORTHEASTWARD INTO THE REGION. THIS WILL LEAD TO A CONSIDERABLE
AMOUNT OF LOW LEVEL (3.5-5KFT AFL) CLOUDS THROUGH THE PERIOD. DUE TO
DRIER AIR IN THE LOWEST LEVELS...THESE CLOUDS SHOULD NOT LOWER BELOW
2KFT AGL...DURING THE 5Z TO 15Z PERIOD PER MODEL FORECAST SOUNDING
AND LAMP DATA. OTHERWISE...VFR CONDITIONS SHOULD PERSIST THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS GRAY ME
1155 AM EST SUN DEC 1 2013
.SYNOPSIS...
WEAK LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLIDE SOUTHEAST
ACROSS THE AREA THROUGH TONIGHT. A SECOND WEAK LOW WILL TRACK
NORTHEAST AND PASS JUST OFFSHORE TONIGHT AND EARLY MONDAY. THESE
TWO SYSTEMS WILL PRODUCE SOME OCCASIONAL LIGHT SNOW INTO TONIGHT,
WITH MIXING OR A CHANGEOVER TO LIGHT RAIN POSSIBLE NEAR THE COAST.
WEAK TROUGHING ALONG THE COAST KEEPS PRECIPITATION NEARBY ON
MONDAY. LOW PRESSURE TRAVELS UP THE ATLANTIC COASTLINE TUESDAY,
SPREADING MORE PRECIPITATION OVER THE REGION THROUGH WEDNESDAY
MORNING. RIDGING BUILDS IN BRIEFLY BEFORE A COLD FRONT CROSSES THE
REGION THURSDAY.
&&
.NEAR TERM /UNTIL 5 PM THIS AFTERNOON/...
1155 AM...ONLY MINOR ADJUSTMENTS FOR THIS ESTF UPDATE LARGELY TO
REFLECT THE CURRENT MESONET AND SHORT TERM TRENDS.
PREV DISC...
945 AM...THE COASTAL FRONT IS SETTING UP SHOP JUST OFFSHORE THEN
EXTENDS INTO MY EASTERN ZONES AND TO THE WEST OF ROCKLAND. I
LOWERED MAXIMUM TEMPERATURES A BIT IN MANY AREAS AS A RESULT.
MODELS HAVE A WEAK LOW TRAVELING NORTHEAST ALONG THIS BOUNDARY
LATE TODAY AND TONIGHT WITH HEAVIEST QPF FOR MID COAST REGION.
WHILE AREAS NEAR ROCKLAND MAY STAY ON THE WARM SIDE OF THE
BOUNDARY AND SEE MAINLY RAIN...IMMEDIATELY ON THE OTHER SIDE OF
THE BOUNDARY SEVERAL INCHES OF WET SNOW WILL FALL. I MADE
ADJUSTMENTS TO 1ST PERIOD GRIDS BASED ON THE MESONET AND TO
REFLECT THE LATEST RADAR TRENDS FOR BANDED PRECIPITATION. ON THE
WATERS...WINDS AND SEAS TOUCHED MARGINAL SMALL CRAFT ALONG THE
BOUNDARY AND I`VE ISSUED AN SCA FOR AREA OUTSIDE THE BAY FOR THE
NEXT FEW HOURS. HRR WINDS WERE USED TO TAILOR WIND GRIDS TO BETTER
REFLECT THE COASTAL BOUNDARY.
PREV DISC...
640 AM...FORECAST THINKING GENERALLY ON TRACK. ACTUALLY MODELS
SEEM TO HAVE A DECENT HANDLE ON THE CURRENT EVENTS...WITH 06Z
NAM12 HANDLING THE LARGER SCALE WELL...CAPTURING THE SHRA DEVELOPING
OVER CT AND LONG ISLAND SOUND...AND THE RUC PICKING UP ON THE VERY
LIGHT SHSN /MAYBE SNIZZLE?/...OVER THE COASTAL PLAIN....WHERE THIS
SHOULD REMAIN SPOTTY THRU THE MORNING...AND CHANGE TO RA ON THE
COAST....BEFORE STEADIER PRECIP DEVELOPS THIS AFTERNOON. ANY CHANGES
TO THE FORECAST BASED ON CURRENT OBS HAVE BEEN MINOR AND ONLY RUN
THRU APPROX THE FIRST 6 HOURS OF THE FORECAST.
PREVIOUSLY...A SOMEWHAT TRICKY FORECAST TODAY INTO TONIGHT AS
VERY WEAK IMPULSES ALOFT...ONE TO OUR S AND ONE TO OUR N PASS
THROUGH WITHIN LESS THAN 12 HOURS OF EACH OTHER...ALTHOUGH EITHER
ONE IS VERY DYNAMIC. THE FIST ONE...IN THE SRN STREAM ACTUALLY
MOVES THROUGH IN THE NEXT FEW HOURS...WITH VERY WEAK SFC
REFLECTION...AND LIGHT PRECIP ASSOCIATED WITH WEAK WAA AHEAD OF IT
MOVED THRU OVERNIGHT. THE SECOND APPROACHES TODAY...AND GENERATES A
BIT MORE LOW TO MID-LVL WAA...WHICH WORKS WITH COASTAL FRONT...AND
GENERATES AN INVERTED SFC TROUGH. THIS PRODUCES SOME MORE ORGANIZED
FORCING ALONG AND JUST INLAND FROM THE COAST THIS AFTERNOON. WHILE
SOME LIGHT PRECIP IS POSSIBLE THIS MORNING...THE BETTER CHC WILL BE
THIS AFTERNOON INTO THE EVENING AS THE FORCING INCREASES. THIS
PRECIP WILL NOT MOVE IN FROM THE WEST SO MUCH AS IT DEVELOPS ALONG
THE COASTAL FRONT.
COASTAL AREAS...FIRST TIER OF COASTAL ZONES...ARE LIKELY TO START
AS RAIN OR SHIFT TO RAIN QUICKLY...BUT P-TYPE WILL BE SOMEWHAT OF
AN ISSUE FOR INLAND AREAS OF THE COASTAL PLAIN. THE COASTAL FRONT
WILL MOVE INLAND TODAY...SO SOME AREAS THAT SEE SOME LIGHT SNOW
EARLY WILL CHANGE TO RAIN THIS AFTERNOON...AND MOST PLACES IN NH
AND FAR WRN ME WILL BE LIMITED TO ABOUT A TENTH OF TOTAL QPF
ANYWAY...WHICH WILL LIMIT TO SNOWFALL TO AN INCH OR SO...MAYBE A
LITTLE MORE IN THE MTNS...WHERE RATIOS WILL BE HIGHER.
MODELS SEEM TO BE FAIR AGREEMENT WHERE HIGHEST QPF WILL
OCCUR...MAINLY E OF KPWM-KLEW...WHERE QPF TODAY INTO THIS EVE
LOOKS BE 0.3-0.4 INCHES. SO INLAND AREAS OF THE KENNEBEC AND
PENOBSCOT VLYS ARE WHERE THE MOST SNOW IS EXPECTED TO FALL. HERE
WE ARE LOOKING AT GENERALLY ONE TO THREE INCHES...WITH SOME 4 INCH
AMOUNTS POSSIBLE. THE BULLSEYE FOR THE HIGHEST SNOWFALL LOOKS TO
BE IN THE SKOWHEGAN-WATERVILLE-UNITY VICINITY.
HOWEVER...MODELS ARE FAR FROM PERFECT WHEN IT COMES TO INVERTED
TROUGHS...AND THIS COULD END UP SHIFTING A BIT.
&&
.SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 PM MONDAY/...
AS THE WEAK
500MB TROUGH ACTUALLY DEEPENS SLIGHTLY JUST TO OUR E LATE
TONIGHT...EXPECTING SOME WEAK RIDGING ALOFT TO DEVELOP BEHIND IT FOR
MONDAY. WILL LOSE A FEW DEGREES AS WINDS SHIFT N ON THE BACK END OF
THE TROUGH...ESPECIALLY IN THE N...AND THIS COULD TURN BACK TO LIGHT
SN BEFORE IT ENDS IN ERN ZONES. SO PRECIP IS EXPECTED TO WIND DOWN
LATE TONIGHT...WITH A BREAK EXPECTED ON MONDAY...ALTHOUGH WE
PROBABLY WILL NOT SEE MUCH SUN ON MONDAY...AS STAGNANT LOW LVL FLOW
LINGERS. HIGHS SHOULD CLIMB BACK INTO THE MID 30S TO AROUND 40 AGAIN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS WAS THE CASE THE LAST COUPLE OF NIGHTS...NWP CONTINUES TO
INDICATE SRN STREAM S/WV TROF WILL OUTPACE ITS NRN STREAM
COUNTERPART. THE RESULT IS LOW PRES DEVELOPING OFF THE SOUTHEAST
COASTLINE...AND HEADING OUT TO SEA WITH A LATE CAPTURE THAT SWINGS
IT TOWARDS THE CANADIAN MARITIMES.
CONSENSUS IS THAT PCPN WILL ONLY BRUSH THE COAST...WITH THE
MIDCOAST PERHAPS SEEING A LITTLE LONGER DURATION AS LOW PRES CUTS
ACROSS BAROCLINIC ZONE. MODEL GUIDANCE HAS A VERY SHARP NRN EDGE
TO THE SATURATED SNOW GROWTH ZONE...SO WE WILL BE TREADING A VERY
FINE LINE OF SN OR NO SN HEADING INTO TUE. IN FACT...SFC TEMPS
WILL BE MARGINAL ENOUGH THAT SOME RNFL IS POSSIBLE NEAR THE COAST.
AS UPPER TROF CROSSES THE AREA THERE SHOULD BE ENOUGH FORCING AND
RESIDUAL MOISTURE TO BRING SCT SHSN TO MUCH OF THE AREA BEFORE
HIGH PRES BUILDS IN AND ENDS PCPN. THAT RIDGING WILL BE SHORT
LIVED THOUGH...AS NEXT LOW PRES DEVELOPS AND LIFTS INTO CANADA.
THIS WILL DRIVE A COLD FNT TOWARDS NEW ENGLAND. AFTER INITIAL
BURST OF WAA AHEAD OF THE LOW PRES...COLD WILL SLOWLY OOZE INTO
THE AREA AS FNT BECOMES ALIGNED WITH FLOW ALOFT. AS LONG AS
BOUNDARY REMAINS IN THE AREA IT WILL BE HARD TO RULE OUT
OVERRUNNING PCPN IN BROAD SWLY WAA REGIME.
LATE IN THE WEEK STRONG HIGH PRES WILL BUILD INTO THE
REGION...BEFORE WRN TROF EJECTS NEWD. GIVEN LOCATION OF HIGH
PRES...IT WOULD NOT BE SURPRISING TO SEE NWP TREND COOLER WITH
TIME...THOUGH THERE ARE SEVERAL DAYS BEFORE ANY DETAILS WILL
BECOME MORE CLEAR.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...SHOULD SEE ALL TERMINALS GET A PERIOD OF MVFR TO IFR
TODAY WITH SHSN INLAND...AND SHRA ON THE COAST. A STEADIER RA IS
EXPECTED AT KRKD...AND A STEADY MIX OF RASN AT KAUG. CONDITIONS
WILL IMPROVE LATE TONIGHT TO VFR FROM KPWM WWD...AND EVENTUALLY AT
KAUG/KRKD ON MONDAY.
LONG TERM...AREAS OF MVFR OR LOWER CONDITIONS WILL BE POSSIBLE TUE
INTO WED AS OCEAN LOW PRES PASS OUT TO SEA. COASTAL TERMINALS WILL
SEE LOWER CIGS AS WELL AS POSSIBLE SHSN LIMITING VSBYS. PASSAGE OF
UPPER TROF MAY ALSO RESULT IN SOME MTNS SHWRS INVOF OF KHIE.
&&
.MARINE...
SHORT TERM...SOUTHERLY SURGE IN WINDS OCCURRING ATTM AND COULD SEE
A FEW GUSTS UP TO 25 KT THRU SUNRISE. OTHERWISE...QUIET WEATHER
WITH VSBY RESTRICTIONS EXPECTED LATER TONIGHT THROUGH SUNDAY NIGHT
IN DEVELOPING RAIN AND SNOW.
LONG TERM...STILL SOME UNCERTAINTY REGARDING THE TRACK OF COASTAL
LOW PRES MIDWEEK. HOWEVER CONFIDENCE IS GROWING THAT SEAS WILL
BUILD TO AT OR ABOVE 5 FT FOR TUE AND WED. WINDS MORE THAN LIKELY
SHOULD REMAIN AT OR BELOW 25 KTS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR ANZ150-
152-154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1147 AM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE IS EXPECTED TO CROSS THE STATE TODAY AND REDEVELOP IN
THE GULF OF MAINE TONIGHT, PASSING WELL E OF THE REGION ON MONDAY.
ANOTHER LOW MAY AFFECT THE REGION FROM THE SOUTH TOWARD THE
MIDDLE PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1145 AM UPDATE...A SMALL BAND OF MODERATE SNOW HAS DEVELOPED
ACROSS PORTIONS OF NE AROOSTOOK COUNTY, STRETCHING FROM CARIBOU TO
PORTAGE. LOCATIONS UNDER THIS BAND HAVE PICKED UP A QUARTER TO A
HALF AN INCH OF NEW SNOW. ANOTHER LARGER AREA OF STEADY SNOW CAN
BE SEEN STRETCHING FROM BETWEEN HOULTON AND DANFORTH BACK TOWARD
LINCOLN AND DOVER-FOXCROFT. BOTH OF THESE BANDS OF SNOW WILL
SLOWLY SINK SOUTHWARD THROUGH THE REMAINDER OF THE AFTERNOON. HAVE
UPDATED POPS AND SNOW ACCUMULATIONS TO MATCH THESE TRENDS. ALSO
TWEAKED TEMPERATURES A BIT DOWNEAST AS THERE IS A VERY TIGHT
GRADIENT BETWEEN THE IMMEDIATE COAST (TEMPS IN UPPER 30S) AND
INTERIOR AREAS (BANGOR, WESLEY, AND CHERRYFIELD STILL IN THE LOWER
30S). WITH THIS GRADIENT TO HOLD FAIRLY STEADY, SOME OF THE
INTERIOR DOWNEAST COULD SEE SNOW HOLD ON LONGER WITH LITTLE TO NO
RAIN, MEANING SNOW AMOUNTS WILL BE A BIT HIGHER. SNOW
ACCUMULATIONS WERE ADJUSTED AS NEEDED FOR THIS, AS WELL. NO OTHER
CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...WEAK LOW PRES MOVING ACROSS THE EASTERN
GREAT LAKES IS FCST TO MOVE ACROSS SOUTHERN NEW ENGLAND THIS
AFTERNOON AND THEN INTO THE GULF OF MAINE. THE CONCERN IS WHERE
TO DRAW THE RAIN/SNOW LINE AS WAA MAKES ITS WAY TO THE BLYR.
TEMPERATURES ARE FCST TO REACH INTO THE UPPER 20S TO AROUND 30
ACROSS THE NORTHERN 1/2 OF THE CWA WHILE LOW TO MID 30S ARE
EXPECTED FOR CENTRAL AND DOWNEAST AREAS. AN INVERTED TROF
EXTENDING FROM THE LOW COMBINED W/SOME FRONTOGENETICAL FORCING AT
1000-700MB WILL LEAD TO A REFORMATION OF PRECIP AND AN ENHANCEMENT
OF THE PRECIP. USING THE BUFKIT PROFILES AND SOUNDINGS, THINKING
HERE IS THAT SNOW WILL REDEVELOP ACROSS PORTION OF NORTHEAST MAINE
W/THE HEAVIEST AXIS ACROSS THE HOULTON AND DANFORTH REGION W/LESS
SNOW NORTH AND WEST. S OF OF THE HOULTON-DANFORTH LINE,
TEMPERATURES WILL WARM INTO THE MID 30S TO ALLOW FOR SNOW TO MIX
WITH AND CHANGEOVER TO RAIN. THIS IN TURN WILL CUT DOWN ON
SNOWFALL LATER THIS AFTERNOON INTO TONIGHT. DECISION WAS TO GO
AHEAD AND ADD NORTHERN PENOBSCOT AND SE AROOSTOOK COUNTY IN THE
WINTER WEATHER ADVISORY THROUGH MONDAY MORNING DUE TO ENHANCED
FRONTOGENTICAL FORCING LEADING TO HEAVY SNOW BURSTS. LATEST SNOW
TOTAL MAP SHOWS A GENERAL 4-8 INCHES IN THE ADVISORY AREA W/1-4
INCHES N AND W. THE COAST AND EXTREME EASTERN WASHINGTON COUNTY
FROM MEDDYBEMPS TO EASTPORT WILL SEE 0.30 TO 0.70 INCHES OF
RAINFALL AFTER SOME INITIAL SNOWFALL.
SNOW WILL CONTINUE INTO TONIGHT ACROSS THE NORTHEASTERN SECTION OF
MAINE INCLUDING CARIBOU-PRESQUE ISLE DOWN THROUGH DANFORTH. WEST
OF THIS AREA, LITTLE OR NO SNOW AND RAIN/SNOW S OF THIS AREA
W/RAIN FOR THE COAST AS THE WARM AIR IS FCST TO STAY IN. TEMPERATURES
WILL DROP BACK INTO THE UPPER TEENS AND LOWER 20S NORTH AND WEST
AND MID TO UPPER 20S FOR CENTRAL AREAS. LOW 30S FOR THE DOWNEAST
REGION INCLUDING THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
SNOW WILL CONTINUE TO WIND DOWN EARLY MONDAY AS THE INVERTED TROF
EXTENDING FROM THE CANADIAN MARITIMES THROUGH DOWNEAST MAINE MOVES
OFF TO THE NORTHEAST. THERE MAY STILL BE SOME LINGERING LIGHT SNOW
OR SNOW SHOWERS PARTICULARLY ACROSS EASTERN AREAS OTHERWISE EXPECT
MOSTLY CLOUDY SKIES ACROSS THE REGION. MONDAY NIGHT WILL BE MOSTLY
CLOUDY BUT DRY AS WEAK HIGH PRESSURE RIDGES DOWN FROM THE NORTH.
ATTENTION THEN TURNS TO ANOTHER LOW PRESSURE SYSTEM THAT WILL BE
MOVING NORTHEAST ACROSS THE WESTERN ATLANTIC. THIS SYSTEM MAY BRINGS
SOME PRECIPITATION TO THE REGION LATER TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS SEEM TO BE COMING INTO BETTER AGREEMENT FOR THE NEXT SYSTEM
TUESDAY NIGHT AND WEDNESDAY. STILL SOME MODEL DIFFERENCES BUT THE
CONSENSUS SOLUTION IS FOR THE LOW TO TRACK FAR ENOUGH EAST THAT ANY
IMPACTS IN OUR REGION WOULD BE ACROSS DOWNEAST/EASTERN MAINE.
A WEAK BOUNDARY WILL CROSS THE REGION BY LATE WEEK WITH SOME
SNOW/RAIN SHOWERS POSSIBLE. AGAIN...WILL STICK CLOSE TO THE
SUPERBLEND.
HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION BY SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: MVFR W/PERIODS OF VFR THIS MORNING DROPPING TO MVFR AND
EVEN IFR LATER THIS MORNING ON INTO TONIGHT. SNOW ACROSS THE NORTHERN
TERMINALS W/SNOW TO RAIN FOR KBGR TO KBHB.
SHORT TERM: MVFR CONDS ARE POSSIBLE EARLY MONDAY THEN VFR CONDS
EXPECTED MONDAY NIGHT INTO TUESDAY. MVFR CONDS ARE POSSIBLE IN
SOME LIGHT PRECIP LATE TUESDAY AND INTO EARLY WEDNESDAY. VFR ON
THURSDAY.
&&
.MARINE...
NEAR TERM: THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED THROUGH 4 PM
THIS AFTERNOON FOR THE OUTER WATERS AS BUOYS ARE STILL REPORTING
WINDS GUSTING 20-25 KT AND WAVES 5-6 FT. CONDITIONS IN THE INNER
WATERS HAVE IMPROVED, SO THE SCA WAS ALLOWED TO EXPIRE THERE.
PREVIOUS DISCUSSION...DECIDED TO GO W/A SCA THROUGH LATE MORNING. WINDS
GUSTING TO 25 KTS AS LLVL JET OF 30 KT MOVES ACROSS THE WATERS.
THE GFS AND NAM AS WELL AS THE LATEST RAP MODEL PICK UP ON THIS
FEATURE. WINDS ARE FCST TO DROP OFF THIS AFTERNOON AS THE LLVL JET
SHIFTS TO THE E. SEAS ARE AT 5FT AND COULD TIP 6 FT ESPECIALLY AT
44027(JONESPORT) THIS MORNING. SEAS WILL GRADUALLY SUBSIDE TONIGHT
BELOW 4 FT.
SHORT TERM: WINDS/SEAS WILL BE BELOW SCA LEVELS MON AND MON NIGHT.
WIND/SEAS MAY INCREASE TO SCA LEVELS TUE/TUE NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MEZ005-006-
011-016-017-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ050-
051.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1250 PM EST SUN DEC 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM EST SUN DEC 1 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR GRT LKS TO THE SW OF UPR TROF CENTERED OVER NRN QUEBEC. IN
THE WAKE OF DEPARTING SHRTWV MOVING THRU SW QUEBEC...A SHRTWV RDG IS
SLIDING SEWD THRU NW ONTARIO...SUPPORTING A SFC HI PRES OVER FAR NW
ONTARIO. CLOSER TO UPR MI...A LO PRES TROF IS APRNT NEAR THE LK SUP
SHORE OF UPR MI AND EXTENDING WNW IN THE MN ARROWHEAD. THIS TROF HAS
BEEN THE FOCUS FOR SOME BANDS OF HIER REFLECTIVITY SHOWN ON THE MQT
88D REFLECTIVITY WITH UPSLOPE N WINDS NEAR LK SUP. SINCE H85 TEMPS
ARE ONLY -7 TO -8C AND THE ACCOMPANYING MSTR IS RELATIVELY SHALLOW
AS DIAGNOSED FM THE MQT 88D VWP AS WELL AS THE 00Z INL RAOB...WHICH
SHOWS INVRN BASE NEAR H85 UNDER VERY DRY MID LVLS AHEAD OF APRCHG
SHRTWV RDG...ASSOCIATED PCPN HAS BEEN A MIX OF -SHSN AND SOME -FZDZ.
THE 00Z YPL RAOB SHOWS SHALLOW MSTR AS WELL BLO AN INVRN NEAR
H925...SO PLENTY OF LO CLDS EXTEND WELL N INTO ONTARIO. THE AIR IS
MUCH COLDER THERE WITH SFC TEMPS IN THE TEENS...SO SPOTTY LGT PCPN
IS IN THE FORM OF SN.
MAIN FCST CONCERN IN THE SHORT TERM IS THE POTENTIAL FOR SOME LGT
-SN AND -FZDZ.
TODAY...WITH APRCH OF SHRTWV RDG NOW IN NW ONTARIO...LARGER SCALE
QVECTOR DVGC/MID LVL DRYING IS FCST TO SLOWLY WEAKEN...BUT NOT
ELIMINATE ALTOGETHER...THE SFC TROF NOW OVER LK SUP AND INHIBIT ANY
LARGER SCALE PCPN. SFC HI PRES NOW OVER FAR NW ONTARIO IS PROGGED TO
DRIFT ONLY SLOWLY SE ACRS NRN ONTARIO...WITH THE CWA DOMINATED BY
WEAKENING AND SLOWLY VEERING LLVL NE FLOW. WL CONT TO CARRY SOME CHC
POPS NEAR LK SUP IN AREA THAT WL EXPERIENCE AN UPSLOPE WIND
COMPONENT NEAR LINGERING LO PRES TROF OVER THE NCENTRAL. WHETHER
THIS PCPN IS ALL -SN OR REMAINS MIXED WITH SOME -FZDZ IS THE PRIMARY
CONCERN. MODELS REMAIN INCONSISTNET ON FCST H85 TEMPS AND MSTR
DEPTH. FCST H85 TEMPS ARE FCST TO FALL TO ARND -9C BY THE 00Z
NAM/LOCAL WRF-ARW TO -11C BY THE GFS. GIVEN THE WEAKENING WINDS THAT
WL LIMIT LLVL CAD AND EXPECTED NEGATIVE DYNAMICS AS WELL AS UPSTREAM
RAOBS...PREFER THE SOMEWHAT WARMER H85 TEMPS AND SHALLOWER MSTR
PROFILE/LOWER INVRN BASE SHOWN BY THE 00Z LOCAL WRF-ARW MODEL. THIS
MODEL SHOWS THE UPSLOPE UVV AND INVRN BASE REMAINING NR 5K FT AGL
AND BLO THE DGZ... SO WL RETAIN A MIX OF -SN/-FZDZ THRU THE DAY.
MARGINAL H85 TEMPS RELATIVE TO LK WATER TEMP ARND 4C WL LIMIT ANY SN
ACCUM. WITH PLENTY OF LO CLDS...TEMPS SHOULD REBOUND ONLY SLIGHTLY
THRU THE DAY.
TNGT...VERY LGT LLVL WINDS ARE PROGGED TO SLOWLY VEER TO THE E AND
SE AS THE CENTER OF SFC HI PRES SHIFTS INTO QUEBEC. SUSPECT
LINGERING LK EFFECT PCPN WL DRIFT INTO THE KEWEENAW AS THE FLOW
GRDLY SHIFTS TO THE ESE. IN THE ABSENCE OF ANY DYNAMIC SUPPORT...
EXPECT THE INVRN BASE TO REMAIN NEAR 5K FT. AS POINTED OUT BY THE
DAYSHIFT...LK VORTICES OFTEN DVLP WITH THE FCST LGT LLVL WINDS. BUT
MARGINAL H85 TEMPS ARND -9C WL LIMIT THE INTENSITY OF ANY SHSN THAT
WOULD ACCOMPANY THESE FEATURES...AND THE LGT WINDS WL INHIBIT
BANDING. SO ANY SN ACCUMS SHOULD REMAIN LGT. SINCE THE H85 TEMPS WL
REMAIN MARGINAL FOR LES AND UPSLOPE OMEGA WL REMAIN BLO THE
DGZ...INCLUDED A MENTION OF FZDZ. LINGERING LO CLDS WL LIMIT THE
DIURNAL TEMP FALL. BEST CHC FOR SOMEWHAT LOWER TEMPS WL BE OVER THE
E WITH A RELATIVELY UNMODIFIED/DOWNSLOPE E FLOW OFF ONTARIO THAT
MIGHT ALLOW FOR SOME BREAKS IN THE SC.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 430 AM EST SUN DEC 1 2013
MONDAY THROUGH TUESDAY MORNING...UPPER LEVEL 500MB TROUGHING IS
EXPECTED TO REMAIN IN PLACE ACROSS THE CWA THROUGH THIS TIME PERIOD
AS A WEAK INVERTED RIDGE WEDGES IN ACROSS THE AREA AT THE SURFACE. A
SLIGHTLY DRYER AIRMASS WILL ALSO LINGER THROUGH TUESDAY MORNING
WHICH CAN BE SEEN BY ANALYZING 1000-500MB RH. THE NEXT SURFACE LOW
CAN BE SEEN PUSHING ACROSS THE NORTHERN ROCKIES MONDAY NIGHT AND
EJECTING INTO THE NORTHERN OR CENTRAL PLAINS TUESDAY MORNING AS A
MUCH DEEPER UPPER LEVEL 500MB TROUGH BUILDS IN OVER THE WESTERN U.S.
THERE ARE STILL SOME MODEL DIFFERENCE HOWEVER WITH THE 00Z GFS/NAM
BEING A BIT FASTER AND STRONGER WITH THIS LOW. THE 00Z GFS/NAM
PLACE THE SURFACE LOW ALONG THE NORTH AND SOUTH DAKOTA BORDER BY 12Z
ON TUESDAY. THE 00Z EC/GEM ARE THE SLOWER OF THE SOLUTIONS KEEPING
THE LOW A BIT FARTHER SOUTH AND REMAINING OVER THE CENTRAL PLAINS
JUST A BIT EAST OF THE ROCKIES. EITHER WAY...BOTH SOLUTIONS KEEP THE
PRECIPITATION TO THE WEST OF THE AREA THROUGH THIS TIME PERIOD.
LIGHT EASTERLY WINDS THROUGH MONDAY NIGHT WILL SLOWLY BECOME
SOUTHEASTERLY BY TUESDAY. THIS ALONG WITH H850 TEMPS AROUND -8 TO
-10 C WILL HELP TO KEEP CONDITIONS CLOUDY WITH VERY LIGHT
PRECIPITATION POSSIBLE...MAINLY OVER THE KEWEENAW PENINSULA.
TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...THIS TIME PERIOD REMAINS
UNCERTAIN WHICH HAS BEEN THE CASE OVER THE PAST SEVERAL DAYS...WITH
POOR MODEL AGREEMENT EVEN AS THIS TIME PERIOD IS RAPIDLY
APPROACHING...HOWEVER...THE 00Z EC TENDS TO BE TRENDING A BIT CLOSER
TO THE NAM AND GFS SOLUTIONS. THE GFS/NAM SOLUTIONS BRING INCREASED
MOISTURE AND PRECIPITATION INTO THE CWA BY 18Z TUESDAY...WHILE THE
EC/CANADIAN KEEP THE SYSTEM CENTERED OVER NORTHEASTERN KS DURING
THAT TIME FRAME. THE 00Z GFS PLACES THE SURFACE LOW AND VERTICALLY
STACKED CLOSED UPPER LEVEL 500MB LOW OVER WESTERN WI AT 00Z WED
WHILE THE 00Z EC HAS THE MORE ELONGATED SURFACE LOW OVER CENTRAL
IOWA INTO CENTRAL PLAINS. BY 18Z WED THE 00Z RUN OF THE GFS PUSHES
THE LOW TO THE NORTHEAST OF LAKE SUPERIOR WHILE THE EC IS JUST
PLACING THE SURFACE LOW AND UPPER LEVEL ENERGY INTO THE WESTERN
PORTION OF WI. DEFINITELY EASY TO SEE THAT THERE ARE STILL
SIGNIFICANT DIFFERENCES BETWEEN THESE MODELS...HOWEVER...A BETTER
SIGNAL EXISTS SINCE THE EC IS TRENDING A BIT CLOSES TO THE FASTER
SOLUTIONS...THE BEST IDEA FOR THE TIME BEING WILL BE MORE OF A
MIDDLE OF THE ROAD APPROACH...WITH A SLIGHT LEAN TOWARD THE FASTER
SOLUTIONS. THIS WOULD FAVOR A LATE TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT TIME FRAME FOR THE MORE CONCENTRATED AREA OF PRECIPITATION.
SOUNDINGS FOR THIS TIME PERIOD INDICATE WARMER AIR LIFTING NORTHWARD
ON THE EAST SIDE OF THE LOW HELPING TO TRANSITION THE PRECIPITATION
OVER TO A RAIN SNOW MIXTURE FOR AT LEAST THE EASTERN HALF OF THE
UPPER PENINSULA AS A FAIRLY DEEP WARM LAYER BUILDS IN THROUGH MUCH
OF THE BOUNDARY LAYER. THE FAR WESTERN PORTION OF THE U.P. MAY END
UP SEEING MAINLY SNOW AS SHOWN BY ANALYZING BOTH THE EC AND GFS
PROFILES. IN ANY CASE THIS SYSTEM WILL BE CLOSELY WATCHED OVER THE
NEXT SEVERAL MODEL RUNS TO SEE IF BETTER UPPER AIR SAMPLING CAN
ENTERTAIN GREATER MODEL AGREEMENT.
THURSDAY THROUGH SATURDAY...ATTENTION TURNS TO A POTENTIALLY
PROLONGED PERIOD OF LAKE EFFECT SNOW. MODELS ACTUALLY BECOME IN
BETTER AGREEMENT WITH THE SYSTEM DURING THIS TIME FRAME. EACH OF THE
MODELS SHIFT THE SURFACE LOW NORTHEASTWARD TO NEAR JAMES BY BY 12Z
THURSDAY. AS THIS HAPPENS WINDS WILL SHIFT TO THE WEST ALLOWING LAKE
EFFECT SNOW TO DEVELOP IN AREAS FAVORED BY THAT PARTICULAR WIND
DIRECTION. THURSDAY THROUGH THURSDAY NIGHT THE LAKE EFFECT SNOW WILL
PROBABLY JUST BE STARTING ACROSS THE AREA...BUT SHOULD REMAIN LIGHT.
TRIED TO TREND THE LES CHANCES UPWARD FRIDAY THROUGH SATURDAY AS AN
UPPER LEVEL TROUGH/SHORTWAVE AND INCREASED MOISTURE SHIFTS INTO THE
AREA...ALLOWING FOR ENHANCED LIFT FOR LES TO DEVELOP. ITS STILL A
BIT TOO EARLY TO TELL FOR SURE ABOUT THE OVERALL SNOWFALL
TOTALS...BUT IT DOES LOOK LIKE FRIDAY INTO SATURDAY WILL BE SNOW FOR
WESTERLY WIND FAVORED AREAS OF THE UPPER PENINSULA. AS EARLIER SHIFT
STATED THE SNOW TO LIQUID RATIOS WILL LIKELY BE SLIGHTLY LOWER THAN
USUAL FOR LES AS THE DGZ IS FAIRLY SHALLOW AND FAIRLY LOW IN THE
ATMOSPHERE...WHICH TENDS TO INHIBIT THE MORE FAVORABLE GROWTH RATES
FOR SNOW. STAY TUNED THOUGH AS THIS LES EVENT GETS CLOSER TOWARD THE
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1248 PM EST SUN DEC 1 2013
A MVFR/VFR STRATUS DECK COVERS ALL OF UPPER MICHIGAN THIS AFTERNOON
AND WITH LIGHT NORTHERLY WINDS...EXPECT THAT TO CONTINUE INTO THE
EVENING HOURS. THERE COULD BE SOME BRIEF VISIBILITY RESTRICTIONS AS
KSAW LATE THIS AFTERNOON...AS A LAKE EFFECT BAND IN EASTERN ALGER
COUNTY DROPS SOUTHEAST. LATEST TRENDS ARE FOR SOME WEAKENING AND
WITH WINDS ALOFT WEAKENING AND BECOMING VARIABLE...IT MAY NOT EVEN
MAKE IT THERE. AS LOW LEVEL WINDS BEGIN TO TRANSITION TO THE SOUTH
THIS EVENING AND OVERNIGHT...EXPECT THE LINGERING LAKE EFFECT TO
SHIFT NORTH AND POTENTIALLY BRUSH KCMX. THIS SOUTHERLY WIND WILL
LIKELY LEAD TO CEILINGS RISING TOWARDS VFR OVERNIGHT INTO MONDAY
MORNING...BUT CONFIDENCE IS VERY LOW ON HOW QUICKLY THAT WILL OCCUR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 AM EST SUN DEC 1 2013
EXPECT NE WINDS UP TO 20 KTS EARLY THIS MORNING TO DIMINISH UNDER
15 KTS AND SLOWLY VEER INTO MON AS A WEAK PRES GRADIENT EXTENDING S
FROM HI PRES MOVING THRU ONTARIO DOMINATES THE UPPER LAKES. STRONGER
E TO SE WINDS UP TO 25 TO PERHAPS 30 KTS WILL THEN DEVELOP INTO MID
WEEK AS THE GRADIENT SHARPENS OVER LAKE SUP BETWEEN THE HI PRES
SHIFTING INTO QUEBEC AND LO PRES MOVING NE FROM THE PLAINS. THERE
WILL BE A SHARP WIND SHIFT TO THE WNW BY THU FOLLOWING THE PASSAGE
OF THE LO TO THE NE. DEPENDING ON THE TRACK AND INTENSITY OF THIS
LO...THERE COULD BE A W GALE ON THU INTO FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...SRF
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1148 AM CST Sun Dec 1 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Sun Dec 1 2013
Think the challenge for today will be forecasting cloud cover. A
stratus deck between 4000-5000ft is moving across he eastern Ozarks
and parts of Southern Illinois this morning. Think this area of
stratus will continue advecting eastward faster than the western
edge will erode as has been the case for the past few hours.
Therefore there should be substantial cloud cover over southeast
Missouri and parts of southern Illinois this morning. The 00Z NAM
eventually cleared it out and this matches well with satellite
trends at this time; however the RAP backbuilds the cloud cover, as
does the 06Z NAM and this suggests that areas generally southeast of
a line from Vichy, MO to Salem, IL may not see much sun today. Am
sticking closer to the less cloudy solution at this time, but this
may ultimately prove to be too optimistic.
Temperatures may be challenging as well. Can`t seem to forecast
warm enough the past couple of days. Missed highs both Friday and
Saturday by to to three degrees. Lingering cloud cover over the
eastern Ozarks and southwest Illinois may make this especially
challenging. For highs today, used a blend of 925 mix-down
temperatures and MOS. Tweaked southern zones down a couple of
degrees from that to account for cloud cover, and the rest of the
area up a degree or two to try to compensate for my apparent cool
bias.
Britt
.LONG TERM: (Tonight through Saturday)
Issued at 335 AM CST Sun Dec 1 2013
(Tonight - Tuesday)
Have not made too many changes to going forecast during this
period. Low level moisture progs suggest that stratus will
redevelop this evening, particularly over the southern and
eastern part of the CWA. Have kept chance of light drizzle in
these areas where this moisture will be the deepest and there will
be some very light ascent. As we go into Monday, GFS/NAM/ECMWF all
show a weak shortwave trough racing into the area from the west,
though it is not as deep as was forecast 24 hours ago. Have left
chance of sprinkles in for tomorrow morning as the trough axis
will move through the area by midday.
Temperatures will begin to warm up ahead ahead of the next storm
system. Expect temperatures to climb into the 50s on Monday with
some spots reaching 60 on Tuesday.
(Wednesday - Saturday)
Main concern continues to be the potential for a wintry precipitation
and the big cool down mid to late week. There still ia a great
deal of uncertainty regarding timing, precipitation types and
amounts. While the GFS is still the fastest with the passage of
the cold front, the 00Z ECMWF now brings the cold front through
the area during the day on Wednesday instead of Wednesday Night.
The cold front will have moved to the south of the area
Wednesday. Best forcing for precipitation will hinge on mid-level
frontogenesis and shortwave troughs moving through fast west-
southwesterly flow aloft. Have likely pops on Thursday and
Thursday Night over southeastern half of the CWA with the chance
continuing into Friday. Will continue to have a simple mix of rain
and snow because of the uncertainty for now, but thermal profiles
from forecast soundings certainly suggest the potential for sleet
or freezing rain over the southern half of the CWA. 850mb
temperatures by next Friday and Saturday will be in the -10 to
-12C range supporting highs only in the 20s with lows in the
single digits and teens.
Britt
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1050 AM CST Sun Dec 1 2013
Very weak cold front has just pushed se of CPS late this mrng.
Only expect light nely sfc winds at UIN and COU this aftn, and
nwly in the St Louis metro area veering around to a nely direction
by early evng. The sfc wind will remain light tgt and continue to
veer around to an e-sely direction by late tgt as the sfc ridge
over the nrn Plains moves ewd through the Great Lakes region. The
sfc wind will strengthen some from a sely direction Monday mrng.
Mid-high level clouds will advect into the region tgt. It appears
that there will be patchy fog and stratus clouds redeveloping late
tgt. The best potential for stratus clouds may be south of the taf
sites, but there will likely be at least light fog impacting the
COU and St Louis areas and possibly also UIN as well.
Specifics for KSTL: Light nwly sfc wind this aftn will gradually
veer around to a nely direction by this evng, e-sely direction by
late tgt, then strengthen to 7-9 kts from a s-sely direction Monday
aftn. Mid-high level cloudiness will advect into STL by late tgt.
May also have some light fog late tgt/early Monday mrng as well as
patchy stratus clouds mainly Monday mrng.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
325 PM MST SUN DEC 1 2013
.DISCUSSION...
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
&&
.AVIATION...
18Z TAF CYCLE
LOW CLOUDS AND FOG HANGING VERY TOUGH OVER NORTHWEST AND WEST
CENTRAL NM. UPDATED SKY COVER TO KEEP LOW CLOUDS OVER THE AREA
DESPITE MOST MODEL GUIDANCE SCOURING OUT CLOUD COVER. LATEST
VISIBLE SATELLITE IMAGERY SHOWS AREA ACTUALLY EXPANDING SLIGHTLY.
ALSO NEEDED TO LOWER MAX TEMPS QUITE A BIT ACROSS THIS AREA AS
VERY LITTLE WARMING IS NOW EXPECTED. LOW CLOUDS MAY EVEN STAY
IN PLACE TONIGHT SINCE THE AREA IS LIKELY PROVIDING A FEEDBACK
TO VERY STRONG INVERSIONS IN PLACE. BY MONDAY ATMOSPHERIC WINDS
AND THE SURFACE PRESSURE GRADIENT BEGIN INCREASING AHEAD OF A
STRONG PACIFIC FRONT FOR LATE TUESDAY/WEDNESDAY.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 28 44 28 50 / 0 0 0 0
DULCE........................... 20 47 21 44 / 0 0 0 10
CUBA............................ 25 50 25 49 / 0 0 0 0
GALLUP.......................... 24 52 24 50 / 0 0 0 0
EL MORRO........................ 23 51 24 48 / 0 0 0 0
GRANTS.......................... 23 54 24 52 / 0 0 0 0
QUEMADO......................... 26 55 27 54 / 0 0 0 0
GLENWOOD........................ 30 64 29 59 / 0 0 0 0
CHAMA........................... 17 44 19 37 / 0 0 0 20
LOS ALAMOS...................... 27 49 28 47 / 0 0 0 0
PECOS........................... 31 49 30 44 / 0 0 0 0
CERRO/QUESTA.................... 7 42 11 38 / 0 0 0 0
RED RIVER....................... 16 40 18 35 / 0 0 5 0
ANGEL FIRE...................... 23 42 24 38 / 0 0 0 0
TAOS............................ 12 45 16 43 / 0 0 0 0
MORA............................ 27 51 28 47 / 0 0 0 0
ESPANOLA........................ 24 51 26 50 / 0 0 0 0
SANTA FE........................ 27 48 27 45 / 0 0 0 0
SANTA FE AIRPORT................ 27 52 27 50 / 0 0 0 0
ALBUQUERQUE FOOTHILLS........... 33 55 33 56 / 0 0 0 0
ALBUQUERQUE HEIGHTS............. 33 57 34 57 / 0 0 0 0
ALBUQUERQUE VALLEY.............. 31 58 30 59 / 0 0 0 0
ALBUQUERQUE WEST MESA........... 31 58 32 59 / 0 0 0 0
LOS LUNAS....................... 30 58 29 61 / 0 0 0 0
RIO RANCHO...................... 31 57 32 58 / 0 0 0 0
SOCORRO......................... 33 61 33 65 / 0 0 0 0
SANDIA PARK/CEDAR CREST......... 31 52 32 53 / 0 0 0 0
TIJERAS......................... 32 54 33 54 / 0 0 0 0
MORIARTY/ESTANCIA............... 25 50 27 49 / 0 0 0 0
CLINES CORNERS.................. 31 51 32 50 / 0 0 0 0
GRAN QUIVIRA.................... 34 53 33 54 / 0 0 0 0
CARRIZOZO....................... 34 59 33 58 / 0 0 0 0
RUIDOSO......................... 39 60 39 57 / 0 0 0 0
CAPULIN......................... 30 58 31 51 / 0 0 0 0
RATON........................... 28 60 29 54 / 0 0 0 0
SPRINGER........................ 27 62 28 56 / 0 0 0 0
LAS VEGAS....................... 30 60 31 51 / 0 0 0 0
CLAYTON......................... 35 66 36 56 / 0 0 0 0
ROY............................. 34 65 35 59 / 0 0 0 0
CONCHAS......................... 37 67 37 63 / 0 0 0 0
SANTA ROSA...................... 40 66 40 64 / 0 0 0 0
TUCUMCARI....................... 37 69 38 68 / 0 0 0 0
CLOVIS.......................... 39 66 40 67 / 0 0 0 0
PORTALES........................ 41 68 41 68 / 0 0 0 0
FORT SUMNER..................... 42 68 42 69 / 0 0 0 0
ROSWELL......................... 42 74 42 77 / 0 0 0 0
PICACHO......................... 42 70 42 67 / 0 0 0 0
ELK............................. 42 67 42 62 / 0 0 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1203 AM EST SUN DEC 1 2013
.SYNOPSIS...
LOW PRESSURE WILL GRADUALLY DEVELOP OFF THE CAROLINA COAST LATE
TODAY INTO TONIGHT...MOVING OUT TO SEA MONDAY. WEAK HIGH PRESSURE
WILL MOVE ACROSS THE AREA TUESDAY AND OFFSHORE WEDNESDAY...BRINGING
SEVERAL DAYS OF WARM TEMPERATURES LATE THIS WEEK. THE NEXT COLD
FRONT WILL APPROACH FROM THE WEST SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SUNDAY...CHANGES WITH THIS EARLY AFTERNOON UPDATE
INCLUDING TRIMMING BACK POPS EVEN FURTHER...WITH THE CHANCE OF
MEASURABLE PRECIPITATION NOW CONFINED TO AREAS ALONG AND EAST OF
MYRTLE BEACH...ACME/DELCO...AND BURGAW. ON LAND MY HIGHEST POPS
THROUGH THE AFTERNOON REMAIN ON THE TIP OF CAPE FEAR...ABOUT A 40
PERCENT CHANCE OF 0.01 INCHES OR MORE REACHING THE BOTTOM OF A
HYPOTHETICAL RAIN GAUGE. NO SIGNIFICANT CHANGES HAVE BEEN MADE TO
SKY COVER OR TEMPERATURES. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS...
MODELS OVER THE PAST TWO DAYS HAVE DONE AN ABYSMAL JOB FORECASTING
HOW THE WEATHER HAS ACTUALLY UNFOLDED OVER THE PAST 6-12 HOURS. NOT
ONLY IS ISENTROPIC LIFT STRONGER AND COVERAGE OF SHOWERS MORE
WIDESPREAD NOW OVER THE COASTAL WATERS THAN WAS EXPECTED...BUT THE
06Z GFS AND NAM PLUS THE 12Z RUC PAINT A PICTURE OF DRIER WEATHER
DEVELOPING INTO TONIGHT AS WHAT ISENTROPIC LIFT WE CURRENTLY HAVE
TRICKLES OFFSHORE AND DRIER AIR ARRIVES FROM THE WEST AND SOUTHWEST
WITHIN THE 5000-10000 FOOT LAYER.
COMPARED TO 12Z SOUNDINGS ALL THE MODELS ARE STRUGGLING WITH WHAT IS
GOING ON BELOW 10000 FEET THIS MORNING. THIS WAS PARTICULARLY
APPARENT AT CHS WHERE THE GFS HAD A HORRIBLE HANDLE (TOO WET) ON
MOISTURE WITHIN THE 800-900 MB LAYER. ALL THE MODELS FAILED TO
PROPERLY SHOW WARM TEMPERATURES BETWEEN 850-1000 MB OBSERVED ON THE
MHX SOUNDING. NEEDLESS TO SAY...THIS CASTS DOUBT ON WHAT (IF ANY)
MODEL GUIDANCE IS TRUSTWORTHY GOING FORWARD THROUGH THIS AFTERNOON
INTO TONIGHT.
MY CURRENT IDEA (BASED ON CURRENT RADAR AND SATELLITE IMAGERY
SPRINKLED WITH RUC/HRRR GUIDANCE THROUGH THE AFTERNOON) IS FOR A
MUCH DRIER AFTERNOON THAN WAS EXPECTED. I HAVE REMOVED POPS FOR THE
PEE DEE COUNTIES IN SOUTH CAROLINA AND TRIMMED BACK POPS ALONG THE
COAST TO NO HIGHER THAN 30-40 PERCENT...HIGHEST ACROSS SOUTHPORT/
CAROLINA BEACH. WITH NO PRECIPITATION INLAND AND SATELLITE IMAGERY
SHOWING BREAKS IN THE OVERCAST ACROSS MUCH OF CENTRAL AND EASTERN
SOUTH CAROLINA I HAVE RAISED FORECAST HIGHS BY 3-4 DEGREES FROM
FLORENCE TO LUMBERTON...WITH UPPER 50S EXPECTED FOR MOST AREAS THIS
AFTERNOON. DRIER AIR ARRIVING THIS AFTERNOON WITHIN THE LAYER
CURRENTLY GENERATING ISENTROPIC LIFT AND SHOWERS (6000-10000 FT)
SHOULD LEAD TO DRY CONDITIONS EVEN ALONG THE COAST. SURPRISINGLY...
THIS DRIER TREND MAY EVEN CONTINUE INTO TONIGHT AS THE 06Z MODELS
(FOR WHAT THEY`RE WORTH) SHOWING SHOWERS REMAINING MAINLY OFFSHORE.
LET`S HOPE THE 12Z RUNS CAN LEND A HAND WITH THAT PORTION OF THE
FORECAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...A SLEW OF SHORTWAVES WILL CROSS THE CAROLINAS,
GA, AND NRN FL ON MONDAY...SOMEWHAT CONGEALING OFF THE SOUTHEAST
COAST LATE IN THE DAY. THE RESULTING SURFACE WAVE OF LOW PRESSURE
THAT HAD BEEN PROGGED TO DEVELOP NOW LOOKS CONSIDERABLY WEAKER.
MORNING RAIN CHANCES ASSOCIATED WITH THIS FEATURE WILL BE FOCUSED
ALONG THE CAPE FEAR/COASTAL NC ZONES BEFORE DECREASING PERHAPS
RAPIDLY LATER IN THE DAY AS DIFFERENTIAL VORTICITY ADVECTION TURNS
QUITE NEGATIVE AND THE LOW LEVEL UPGLIDE LOOKS TO SHUT OFF AS WELL.
TUESDAY THEN BRINGS ZONAL MID LEVEL FLOW THAT SHOULD KEEP THINGS
DRY. AT THE SURFACE THERE WILL WON`T BE MUCH GRADIENT AS A WEAK HIGH
OVER THE CAROLINAS FILLS THE SPACE IN BETWEEN THE DEEPENING ATLANTIC
LOW AND A LARGE SYSTEM GATHERING STRENGTH OVER THE NRN PLAINS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...RIDGE AXIS TO DRIFT OFFSHORE ON WEDNESDAY PAVING
THE WAY FOR SOME RETURN FLOW. EXPECT ABOVE NORMAL HIGHS FOR THE
FIRST TIME IN QUITE A WHILE DESPITE POSSIBLE INCREASE IN LOW TO MID
LEVEL CLOUDINESS. THURSDAY TOO WILL BE MILD AND RATHER CLOUDY AS THE
RETURN FLOW VEERS SOMEWHAT DUE TO THE APPROACH OF A COLD FRONT FROM
THE WEST. THE NE TO SW ORIENTATION OF THE BOUNDARY WILL HAVE IT
QUITE LINED UP WITH THE MID LEVEL FLOW MAKING FOR VERY SLOW
PROGRESSION. IN FACT WE SEE SOME DIFFERENCES IN THE SPEED AT WHICH
THE BOUNDARY APPROACHES AND MOVES THROUGH BETWEEN VARIOUS MODELS.
GIVEN THE VERTICAL DIRECTIONAL ALIGNMENT OF THE FLOW THE SLOWER
SOLUTIONS SEEM MORE PLAUSIBLE.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...MODERATE UNCERTAINTY WITH RESPECT TO CLOUD HEIGHTS. A
COASTAL LOW TRIES TO FORM OVERNIGHT...BUT IT WILL NOT PHASE UNTIL
LATE MONDAY...AFTER IT IS WELL NORTHEAST OF THE REGION. ANY PRECIP
ASSOCIATED WITH IT THIS AFTERNOON WILL BE VERY LIGHT AND PROBABLY
WILL NOT AFFECT VISIBILITY. THINK THE CEILINGS WILL FALL DIURNALLY
THIS EVENING...PERHAPS IFR AT THE MYRTLES MOST OF THE NIGHT. LIGHT
WINDS OVERNIGHT WILL BECOME NORTHERLY MONDAY AFTER THE LOW PULLS TO
THE NORTHEAST. CEILINGS SHOULD IMPROVE TO VFR...HOWEVER IT MAY TAKE
A FEW HOURS AFTER DAYBREAK TO ACCOMPLISH THIS.
EXTENDED OUTLOOK...MAINLY VFR TUESDAY AND WEDNESDAY. LOW CONFIDENCE
FOR SHOWERS THURSDAY AND FRIDAY...MAINLY WEST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM SUNDAY...NO SIGNIFICANT CHANGES ARE NEEDED FOR THIS
EARLY AFTERNOON UPDATE. PREVIOUS DISCUSSION FROM 930 AM FOLLOWS...
FAIRLY WIDESPREAD SHOWER ACTIVITY COVERS THE OUTER PORTION OF THE
COASTAL WATERS THIS MORNING...EXCEPT NEAR CAPE FEAR WHERE THE
SHOWERS ARE ALSO OCCURRING IN THE NEARSHORE WATERS. THIS IS
OCCURRING IN ASSOCIATION WITH A WEAK COASTAL TROUGH NEAR THE WESTERN
EDGE OF THE GULF STREAM. NORTH WINDS SHOULD VEER A LITTLE MORE
NORTHEASTERLY BY THIS AFTERNOON...WITH NO INCREASE IN WIND SPEEDS
EXPECTED. SEAS ARE THE BIG STORY AWAY FROM SHORE AS A PERSISTENT
9-SECOND EASTERLY SWELL CONTINUES TO BRING SIGNIFICANT WAVE ENERGY
INTO THE AREA. THE GENESIS REGION FOR THIS SWELL IS ACTUALLY WELL
OUT INTO THE CENTRAL ATLANTIC WHERE A COUPLE THOUSAND MILES OF
EASTERLY FLOW ALONG THE SOUTH SIDE OF NORTH ATLANTIC HIGH PRESSURE
IS BUILDING QUITE A WAVE FETCH. SEAS OUT AT FRYING PAN SHOALS ARE
AROUND 5 FEET DUE TO THIS SWELL...WITH 3 FEET REPORTED AT THE BUOY
SEVERAL MILES SOUTH OF THE MOUTH OF THE CAPE FEAR RIVER.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...A SERIES OF CONGEALING UPPER LEVEL DISTURBANCES
WILL FORM A SURFACE LOW OFF THE COAST BY MONDAY MORNING. THIS
FEATURE IS NOW SUPPOSED TO BE WEAKER THAN EARLIER FORECASTS AND
POSSIBLY FURTHER OUT TO SEA AS WELL. THIS INCREASES FORECAST
CONFIDENCE THAT NO ADVISORIES OR HEADLINES WILL BE NEEDED AT THIS
TIME AS WINDS MAY BE CAPPED IN THE 10 TO 15 KT RANGE OVER NORTHERN
ZONES WITH PERHAPS JUST 10 KT SOUTH. EVEN LIGHTER WINDS AND SEAS MAY
BE IN THE OFFERING ON TUESDAY AS THIS SYSTEM EXITS AND ANOTHER
DEVELOPS OVER THE NORTHERN PLAINS...WITH ONLY A WEAK HIGH IN BETWEEN
OVER THE CAROLINAS.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...WIND SWINGS AROUND TO THE SOUTH ON WEDNESDAY AS
THE CENTER OF HIGH PRESSURE MOVES OFF THE COAST. NO REAL INCREASE IN
WIND SPEED TO SPEAK OF HOWEVER SO SEAS MAY ACTUALLY CONTINUE TO
SETTLE SOME FROM THEIR TUESDAY VALUES. A COLD FRONT WILL APPROACH
FROM THE NW ON THURSDAY ALBEIT QUITE SLOWLY AS THE BOUNDARY WILL BE
ALIGNED WITH ITS MID LEVEL STEERING FLOW. THE SLOW APPROACH OF THE
FRONT WILL VEER THE WIND SLIGHTLY AND YIELD A GRADUAL INCREASE IN
WIND SPEED. THIS WILL CONTINUE INTO THURSDAY NIGHT AT WHICH TIME
SEAS WILL START RESPONDING TO THE INCREASED FLOW AND FETCH DURATION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
107 PM CST SUN DEC 1 2013
.UPDATE...
ISSUED AT 107 PM CST SUN DEC 1 2013
CANCELLED DENSE FOG ADVISORY AS VISIBILITY HAS RISEN ABOVE 1/2 MILE
AT ALL OBSERVATION SITES EXCEPT A COUPLE (VALLEY CITY/LANGDON).
THERE STILL MAY BE A FEW SPOTS WITH DENSE FOG THROUGH THE
AFTERNOON...BUT IT IS NO LONGER WIDESPREAD ENOUGH TO JUSTIFY AN
ADVISORY. MOTORISTS SHOULD STILL BE PREPARED FOR RAPIDLY CHANGING
DRIVING CONDITIONS...ESPECIALLY AROUND FAVORED LOW SPOTS FOR FOG
FORMATION. LOW CLOUDS ARE REALLY TAKING A BITE OUT OF TEMPERATURES...
SO DROPPED AFTERNOON HIGHS A HANDFUL OF DEGREES. BAND OF LIGHT
SNOW HAS MOVED INTO AREAS WEST OF THE VALLEY AND THIS IS HANDLED
WELL BY CURRENT POPS. REST OF THE FORECAST OK WITH NO OTHER
CHANGES AT THIS TIME.
UPDATE ISSUED AT 1015 AM CST SUN DEC 1 2013
CONCERNS THIS MORNING INCLUDE FOG AND LIGHT SNOW.
DENSE FOG DEVELOPED ACROSS AREAS WEST OF THE VALLEY FROM LANGDON
TO COOPERSTOWN TO GWINNER BETWEEN 7 AND 8 AM CST AND HAS
MAINTAINED ITSELF FOR MUCH OF THE MORNING. LATEST RAP/HRRR
GUIDANCE SUGGESTS POCKETS OF DENSE FOG WILL CONTINUE THROUGH LATE
MORNING AND INTO THE AFTERNOON AND WITH NO REAL CHANGE IN AIR MASS
AND/OR LOW LEVEL WIND FIELD...WILL ISSUE A DENSE FOG ADVISORY FOR
WESTERN TIER COUNTIES UNTIL 21 UTC. MAY VERY WELL BE ABLE TO
CANCEL IT EARLY...BUT VISIBILITIES AT OR BELOW 1/4 SM ARE
WIDESPREAD ENOUGH TO WARRANT ISSUANCE.
ALSO INCREASED POPS A BIT FARTHER EAST ACROSS EASTERN ND THROUGH
THE DAY WITH A NARROW BAND OF LIGHT SNOW JUST ENTERING THE DEVILS
LAKE BASIN. RAP SOUNDING AT KDVL SUGGESTS THERE MAY BE SOME
FREEZING DRIZZLE MIXED IN...BUT UPSTREAM OBSERVATIONS THUS FAR
HAVE BEEN ALL SNOW. PRIMARY MID-LEVEL WARM AIR ADVECTION SNOW
STILL STRETCHES FROM KENMARE TO GARRISON AND WILL IMPACT THE
REGION LATER THIS AFTERNOON AND EVENING. ALSO INTRODUCED SOME 20
POPS ACROSS THE LAKE OF THE WOODS REGION LATE THIS MORNING FOR
SOME LIGHT SNOW BEING REPORTED AT ROSEAU...BAUDETTE AND WASKISH.
TEMPERATURE/SKY/WIND GRIDS ARE IN GOOD SHAPE WITH NO MAJOR CHANGES
AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 418 AM CST SUN DEC 1 2013
00Z/06Z MODELS ARE COMING MORE IN LINE TOWARD A GENERAL CONSENSUS
SOLUTION...WITH THE GFS REMAINING A FAST OUTLIER. EVEN THE NAM IS
SIMILAR TO THE CONSENSUS...JUST STRONGER. THE IDEA IS THAT AN
UPPER LOW WILL DIG INTO THE NORTHWEST CONUS/NORTHERN
ROCKIES...THEN EJECT INTO NORTHERN MINNESOTA BY 12Z WED. MODELS
HAVE REMAINED CONSISTENT INDICATING 3 ROUNDS OF SNOWFALL.
THE FIRST ROUND WILL BE LATER THIS AFTERNOON INTO TONIGHT.
FORCING IS WEAK AND AVAILABLE MOISTURE IS RELATIVELY
LOW...THINKING UP TO AN INCH OF SNOWFALL IS MOST LIKELY.
THE SECOND WAVE (MONDAY INTO MONDAY NIGHT) 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 WESTERN MN ON MONDAY...LOSING DEFINITION MONDAY
NIGHT AS IT PROPAGATES FURTHER TO THE EAST. ASSOCIATED WARM AIR
ADVECTION/FRONTOGENESIS COMBINED WITH THE 0.5 INCH PWATS SHOULD
LEAD TO A BAND OF SNOWFALL MOVING THROUGH THE REGION. MODELS
INDICATE 0.20-0.40 INCHES QPF ACROSS ALL BUT THE NE FA...AND
COMBINED WITH 12:1-13:1 SNOW RATIOS WOULD LEAD TO AN AREA OF 2-5
INCHES OF SNOW. MODELS INDICATE THAT THE MESOSCALE FORCING IS
RELATIVELY WEAK...WHICH WOULD MEAN THE MODELS SHOULD BE IN THE
BALL PARK WITH QPF.
THE THIRD ROUND OF SNOWFALL (TUESDAY-TUESDAY NIGHT) WILL BE
ASSOCIATED WITH THE MAIN STRONG MID-LEVEL LOW MOVING THROUGH THE
REGION. THE 00Z ECMWF IS SLIGHTLY FASTER WITH THIS FEATURE.
SYNOPTIC FORCING WILL BE VERY STRONG...WITH THE POTENTIAL FOR
MESOSCALE BANDING. WITH THAT SAID...THIS ROUND OF SNOWFALL STILL
HAS THE MOST UNCERTAINTY (DUE TO MODEL DIFFERENCES). GIVEN THE
AVAILABLE MOISTURE (PWATS 0.5+ INCHES) AND STRONG FORCING
EXPECTED...ALONG WITH THE SLOW MOVING NATURE OF THE SYSTEM...THIS
ROUND SHOULD BRING 6+ INCHES (CURRENT THOUGHTS ARE 5 TO 10 INCHES)
TO MOST AREAS. SOMETIME TOWARD THE TAIL END OF THE
SNOWFALL...WINDS SHOULD INCREASE...LIKELY STRONG ENOUGH FOR
BLOWING SNOW ISSUES.
SINCE THE TRUE WINTER WARNING CONDITIONS WILL LIKELY NOT OCCUR
UNTIL SOMETIME ON TUESDAY...WILL HOLD OFF ON ISSUING ANY
WINTER HEADLINES. THIS WILL ALLOW FOR ANOTHER SET OF MODEL RUNS TO
INCREASE CONFIDENCE. COULD SEE A SITUATION WHERE WE HAVE ADVISORY
CONDITIONS ON MONDAY/MONDAY NIGHT FOLLOWED BY A SHORT BREAK...THEN
WARNING CRITERIA SNOW TUESDAY/TUESDAY NIGHT (WITH WINDS AND
BLOWING SNOW LATER TUESDAY NIGHT INTO WEDNESDAY). WILL ADD SOME
DETAIL TO THE SPECIAL WEATHER STATEMENT AND HWO.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 418 AM CST SUN DEC 1 2013
WEDNESDAY-SATURDAY...BOTH THE GFS/ECMWF INDICATE SNOW WINDING
DOWN ON WEDNESDAY AS THE SFC LOW PULLS AWAY. DESPITE A TREND
TOWARDS A FASTER SOLUTION...THERE IS STILL SOME UNCERTAINTY WITH
THE 00Z GEM SLOWER WITH THE SFC LOW...KEEPING SNOW AROUND THROUGH
WEDNESDAY NIGHT. SOME LIGHT SNOW/SNOW SHOWERS COULD LINGER INTO
LATE WEEK AS A REINFORCING UPPER LOW PIVOTS SOUTHWARD INTO THE
REGION...MAINTAINING CYCLONIC FLOW. HOWEVER...THE MAIN CONCERN FOR
THE REMAINDER OF THE WEEK WILL BE TEMPS AS A BITTERLY COLD ARCTIC
AIR MASS TAKES UP RESIDENCE ACROSS THE NORTHERN PLAINS. BASED ON A
MORE PROGRESSIVE SOLUTION...STRONG LOW-LEVEL COLD ADVECTION MAY
PREVENT MUCH TEMPERATURE RISE ON WEDNESDAY. 1000-500 MB
THICKNESSES FALL BELOW 500 DAM BY THURSDAY/FRIDAY...WITH HIGHS NO
HIGHER THAN THE LOW SINGLE DIGITS. MODELS INDICATE THE SFC HIGH
AXIS DOES NOT APPROACH UNTIL NEXT WEEKEND. THUS...WITH ONLY A
GRADUAL SLACKENING OF THE PRESSURE GRADIENT...WINDS WILL REMAIN UP
A BIT THROUGH THE WORK WEEK. THE COMBINATION OF WINDS AND BITTERLY
COLD TEMPS LIKELY WILL LEAD TO DANGEROUS WIND CHILLS AT TIMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 107 PM CST SUN DEC 1 2013
IFR AND LOWER CIGS WILL CONTINUE THROUGH THE EARLY AFTERNOON. SAT
LOOP SHOWS SOME CLEARING ON THE BACK SIDE OF THE TROUGH AXIS IN
WESTERN ND...BUT MODELS ALL HAVE THE SFC TROUGH STARTING TO WASH
OUT...WITH THE WESTERLY WINDS NEVER REACHING OUR FORECAST AREA.
THINK THAT THE STRATUS WILL CONTINUE THROUGH THE REST OF THE
DAY...POSSIBLY LIFTING TO MVFR LEVELS FOR A BRIEF PERIOD. CONDITIONS
WILL DETERIORATE AGAIN THIS EVENING AS CIGS DROP BACK DOWN BELOW
1000 FT AND A BAND OF LIGHT SNOW MOVES IN. THE SNOW WILL BE BRIEF
AND ONLY AFFECT TAF SITES FOR A FEW HOURS WITH VIS AROUND 2SM OR SO.
HOWEVER...AFTER THE SNOW MOVES OFF TO THE EAST THE LOW CIGS AND SOME
MIST WILL CONTINUE. THERE WILL BE ANOTHER...HEAVIER BAND OF SNOW
BEGINNING TO MOVE INTO THE FORECAST AREA LATE IN THE PERIOD. THE
BAND COULD BE AS FAR EAST AS KFAR AND KGFK BY 18Z...BUT FOR NOW WILL
JUST INCLUDE A MENTION AT KDVL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...TG
LONG TERM...MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1015 AM CST SUN DEC 1 2013
.UPDATE...
ISSUED AT 1015 AM CST SUN DEC 1 2013
CONCERNS THIS MORNING INCLUDE FOG AND LIGHT SNOW.
DENSE FOG DEVELOPED ACROSS AREAS WEST OF THE VALLEY FROM LANGDON
TO COOPERSTOWN TO GWINNER BETWEEN 7 AND 8 AM CST AND HAS
MAINTAINED ITSELF FOR MUCH OF THE MORNING. LATEST RAP/HRRR
GUIDANCE SUGGESTS POCKETS OF DENSE FOG WILL CONTINUE THROUGH LATE
MORNING AND INTO THE AFTERNOON AND WITH NO REAL CHANGE IN AIR MASS
AND/OR LOW LEVEL WIND FIELD...WILL ISSUE A DENSE FOG ADVISORY FOR
WESTERN TIER COUNTIES UNTIL 21 UTC. MAY VERY WELL BE ABLE TO
CANCEL IT EARLY...BUT VISIBILITIES AT OR BELOW 1/4 SM ARE
WIDESPREAD ENOUGH TO WARRANT ISSUANCE.
ALSO INCREASED POPS A BIT FARTHER EAST ACROSS EASTERN ND THROUGH
THE DAY WITH A NARROW BAND OF LIGHT SNOW JUST ENTERING THE DEVILS
LAKE BASIN. RAP SOUNDING AT KDVL SUGGESTS THERE MAY BE SOME
FREEZING DRIZZLE MIXED IN...BUT UPSTREAM OBSERVATIONS THUS FAR
HAVE BEEN ALL SNOW. PRIMARY MID-LEVEL WARM AIR ADVECTION SNOW
STILL STRETCHES FROM KENMARE TO GARRISON AND WILL IMPACT THE
REGION LATER THIS AFTERNOON AND EVENING. ALSO INTRODUCED SOME 20
POPS ACROSS THE LAKE OF THE WOODS REGION LATE THIS MORNING FOR
SOME LIGHT SNOW BEING REPORTED AT ROSEAU...BAUDETTE AND WASKISH.
TEMPERATURE/SKY/WIND GRIDS ARE IN GOOD SHAPE WITH NO MAJOR CHANGES
AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 418 AM CST SUN DEC 1 2013
00Z/06Z MODELS ARE COMING MORE IN LINE TOWARD A GENERAL CONSENSUS
SOLUTION...WITH THE GFS REMAINING A FAST OUTLIER. EVEN THE NAM IS
SIMILAR TO THE CONSENSUS...JUST STRONGER. THE IDEA IS THAT AN
UPPER LOW WILL DIG INTO THE NORTHWEST CONUS/NORTHERN
ROCKIES...THEN EJECT INTO NORTHERN MINNESOTA BY 12Z WED. MODELS
HAVE REMAINED CONSISTENT INDICATING 3 ROUNDS OF SNOWFALL.
THE FIRST ROUND WILL BE LATER THIS AFTERNOON INTO TONIGHT.
FORCING IS WEAK AND AVAILABLE MOISTURE IS RELATIVELY
LOW...THINKING UP TO AN INCH OF SNOWFALL IS MOST LIKELY.
THE SECOND WAVE (MONDAY INTO MONDAY NIGHT) 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 WESTERN MN ON MONDAY...LOSING DEFINITION MONDAY
NIGHT AS IT PROPAGATES FURTHER TO THE EAST. ASSOCIATED WARM AIR
ADVECTION/FRONTOGENESIS COMBINED WITH THE 0.5 INCH PWATS SHOULD
LEAD TO A BAND OF SNOWFALL MOVING THROUGH THE REGION. MODELS
INDICATE 0.20-0.40 INCHES QPF ACROSS ALL BUT THE NE FA...AND
COMBINED WITH 12:1-13:1 SNOW RATIOS WOULD LEAD TO AN AREA OF 2-5
INCHES OF SNOW. MODELS INDICATE THAT THE MESOSCALE FORCING IS
RELATIVELY WEAK...WHICH WOULD MEAN THE MODELS SHOULD BE IN THE
BALL PARK WITH QPF.
THE THIRD ROUND OF SNOWFALL (TUESDAY-TUESDAY NIGHT) WILL BE
ASSOCIATED WITH THE MAIN STRONG MID-LEVEL LOW MOVING THROUGH THE
REGION. THE 00Z ECMWF IS SLIGHTLY FASTER WITH THIS FEATURE.
SYNOPTIC FORCING WILL BE VERY STRONG...WITH THE POTENTIAL FOR
MESOSCALE BANDING. WITH THAT SAID...THIS ROUND OF SNOWFALL STILL
HAS THE MOST UNCERTAINTY (DUE TO MODEL DIFFERENCES). GIVEN THE
AVAILABLE MOISTURE (PWATS 0.5+ INCHES) AND STRONG FORCING
EXPECTED...ALONG WITH THE SLOW MOVING NATURE OF THE SYSTEM...THIS
ROUND SHOULD BRING 6+ INCHES (CURRENT THOUGHTS ARE 5 TO 10 INCHES)
TO MOST AREAS. SOMETIME TOWARD THE TAIL END OF THE
SNOWFALL...WINDS SHOULD INCREASE...LIKELY STRONG ENOUGH FOR
BLOWING SNOW ISSUES.
SINCE THE TRUE WINTER WARNING CONDITIONS WILL LIKELY NOT OCCUR
UNTIL SOMETIME ON TUESDAY...WILL HOLD OFF ON ISSUING ANY
WINTER HEADLINES. THIS WILL ALLOW FOR ANOTHER SET OF MODEL RUNS TO
INCREASE CONFIDENCE. COULD SEE A SITUATION WHERE WE HAVE ADVISORY
CONDITIONS ON MONDAY/MONDAY NIGHT FOLLOWED BY A SHORT BREAK...THEN
WARNING CRITERIA SNOW TUESDAY/TUESDAY NIGHT (WITH WINDS AND
BLOWING SNOW LATER TUESDAY NIGHT INTO WEDNESDAY). WILL ADD SOME
DETAIL TO THE SPECIAL WEATHER STATEMENT AND HWO.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 418 AM CST SUN DEC 1 2013
WEDNESDAY-SATURDAY...BOTH THE GFS/ECMWF INDICATE SNOW WINDING
DOWN ON WEDNESDAY AS THE SFC LOW PULLS AWAY. DESPITE A TREND
TOWARDS A FASTER SOLUTION...THERE IS STILL SOME UNCERTAINTY WITH
THE 00Z GEM SLOWER WITH THE SFC LOW...KEEPING SNOW AROUND THROUGH
WEDNESDAY NIGHT. SOME LIGHT SNOW/SNOW SHOWERS COULD LINGER INTO
LATE WEEK AS A REINFORCING UPPER LOW PIVOTS SOUTHWARD INTO THE
REGION...MAINTAINING CYCLONIC FLOW. HOWEVER...THE MAIN CONCERN FOR
THE REMAINDER OF THE WEEK WILL BE TEMPS AS A BITTERLY COLD ARCTIC
AIR MASS TAKES UP RESIDENCE ACROSS THE NORTHERN PLAINS. BASED ON A
MORE PROGRESSIVE SOLUTION...STRONG LOW-LEVEL COLD ADVECTION MAY
PREVENT MUCH TEMPERATURE RISE ON WEDNESDAY. 1000-500 MB
THICKNESSES FALL BELOW 500 DAM BY THURSDAY/FRIDAY...WITH HIGHS NO
HIGHER THAN THE LOW SINGLE DIGITS. MODELS INDICATE THE SFC HIGH
AXIS DOES NOT APPROACH UNTIL NEXT WEEKEND. THUS...WITH ONLY A
GRADUAL SLACKENING OF THE PRESSURE GRADIENT...WINDS WILL REMAIN UP
A BIT THROUGH THE WORK WEEK. THE COMBINATION OF WINDS AND BITTERLY
COLD TEMPS LIKELY WILL LEAD TO DANGEROUS WIND CHILLS AT TIMES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CST SUN DEC 1 2013
IFR CONDITIONS WILL LIKELY CONTINUE THROUGH THE MORNING
HOURS...GRADUALLY RISING WITH DAYTIME HEATING (BUT NOT GREATER
THAN MVFR CRITERIA). 10Z RAP GUIDANCE SHOWS THE POTENTIAL FOR A
PERIOD OF VFR CONDITIONS TONIGHT AS LOW LEVEL FLOW INCREASES. THIS
SEEMS LIKE A LOW PROBABILITY OF OCCURRENCE CONSIDERING THAT THE
LOW-LEVEL AIRMASS IS EXPECTED TO REMAIN SATURATED. WILL MONITOR
THE SITUATION AND ADJUST THE FORECASTS AS NEEDED.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR NDZ006-007-
014-015-024-026-028-038-049-052.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...TG
LONG TERM...MAKOWSKI
AVIATION...TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
419 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 /21Z SUNDAY THROUGH FRIDAY/...
A WEAK COLD FRONT/WIND SHIFT WILL DISSIPATE OVER THE OHIO VALLEY
OVERNIGHT TONIGHT AS IT PROGRESSES SOUTHEAST. CLOUD COVER
ASSOCIATED WITH THIS FRONT WILL PRIMARILY BE AN AS DECK. BEFORE
THIS OCCURS...SC OVER AND SOUTHEAST OF I-71 CORRIDOR WILL SLOWLY
ERODE FROM W-E THIS AFTERNOON. ABUNDANT MOISTURE SHOULD ALLOW SC
TO RE-DEVELOP THIS EVENING AND OVERNIGHT ONCE THE LOWER LEVELS
STRATIFY. SOME MVFR VSBYS ARE EXPECTED AND WILL BECOME MORE LIKELY
OVERNIGHT IF THE LOWER STRATUS IS A BIT MORE CUMULUS WITH WIDER
BREAKS. DISSIPATED FRONT OVER THE REGION WILL LEAD TO CONTINUED
LOW AND MID LEVEL MOISTURE WITH LIGHT AND SOMETIMES VARIABLE
WINDS.
OUTLOOK...MVFR CEILINGS POSSIBLE THROUGH TUESDAY MORNING. IFR
CEILINGS AND MVFR VISIBILITIES WILL BE POSSIBLE LATE MONDAY NIGHT.
MVFR CEILINGS AND VISIBILITIES POSSIBLE AGAIN WEDNESDAY INTO
THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
245 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
304 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 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...(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 PI 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.
AMD 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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1110 AM CST SUN DEC 1 2013
WINDS WILL REMAIN LIGHT THROUGH THE PERIOD...WITH A GRADUALLY SHIFT
TO SOUTH TOMORROW MORNING ALONG AND WEST OF I29. VFR CONDITIONS
EXPECTED AND NO PCPN EXPECT AT KHON...KFSD...AND KSUX. AT THIS
POINT...IF THERE IS ANY PCPN...MAY BE A SPRINKLE OR FLURRY
OVERNIGHT IN SW MN BUT VSBYS WOULD REMAIN ABOVE 6SM AND CIGS ABOVE
3000 FT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...SCHUMACHER
LONG TERM...
AVIATION...SCHUMACHER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
307 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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1146 AM CST SUN DEC 1 2013
AS WEAK WARM AIR ADVECTION DEVELOPS ACROSS THE AREA THIS
AFTERNOON A BROKEN 8-10K FOOT DECK OF CLOUDS WILL SPREAD ACROSS
THE AREA. THESE CLOUDS HAVE ALREADY MOVED INTO KRST AND WILL MOVE
INTO KLSE AROUND 01.21Z. THESE CLOUDS WILL GRADUALLY DROP INTO THE
4 TO 8K RANGE OVERNIGHT...AND THEN KRST WILL SEE A BKN015 DECK
DEVELOP AROUND 02.16Z.
WITH THE MODELS CONTINUING TO STRUGGLE ON WHERE THE PRECIPITATION
WILL OCCUR...DID NOT INCLUDE THEM IN EITHER TAF SITE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST 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 18Z TAF ISSUANCE
ISSUED AT 1206 PM CST SUN DEC 1 2013
MVFR CIGS ACROSS MUCH OF FORECAST AREA DURING PERIOD. ISOLATED
IFR CIGS NOTED IN VILAS COUNTY FROM TIME TO TIME. GENERALLY MVFR
CIGS EXPECTED BEFORE MUCH LOWER CIGS AND VSBYS ARRIVE LATE MONDAY
AND EARLY TUESDAY ASSOCIATED WITH NEXT STORM SYSTEM.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......TDH
AVIATION.......JKL
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 AM CST SUN DEC 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CST SUN DEC 1 2013
THE MAIN FOCUS IS ON THE INCREASING CHANCES FOR SNOW
TONIGHT...MAINLY IN SOUTHEAST MINNESOTA...NORTHEAST IOWA AND FAR
WESTERN WISCONSIN.
CURRENTLY...NORTHWESTERLY FLOW ALOFT IS IN PLACE WITH A SURFACE
RIDGE OF HIGH PRESSURE CENTERED ON THE EASTERN DAKOTAS. THE
INITIAL QUESTION THIS MORNING IS WITH A STRATUS DECK THAT EXTENDS
ACROSS NORTHERN WISCONSIN/MINNESOTA AND HOW FAR SOUTH IT WILL MAKE
IT TODAY. THERE HAS NOT BEEN MUCH OF A SOUTHERLY PUSH WITH IT OVER
THE PAST 6 HOURS OR SO...EXCEPT IN EASTERN WISCONSIN ALONG LAKE
MICHIGAN. THE PAST FEW RUNS OF THE HRRR SHOW THIS STRATUS DECK
HAVING TROUBLE MAKING IT SOUTH TODAY AS THE RIDGE OF HIGH PRESSURE
COMES IN AND WEAKENS THE NORTHERLY SURFACE FLOW. IF THIS DECK DOES
MAKE IT FURTHER SOUTH...IT WILL CAUSE TEMPERATURES TO BE ABOUT
5-10F COOLER FOR HIGHS.
GOING INTO TONIGHT...A LEAD/WEAK MID LEVEL SHORT WAVE TROUGH WILL
PROPAGATE EAST ACROSS THE NORTHERN PLAINS WHILE ISENTROPIC LIFT ON
THE 290K SURFACE INCREASES. THIS SHOULD PROVIDE ENOUGH
LIFT...ALBEIT WEAK...TO DEVELOP A BAND OF LIGHT SNOW FROM CENTRAL
MINNESOTA DOWN ALONG THE MISSISSIPPI RIVER. ANY ACCUMULATIONS
OVERNIGHT WILL BE ON THE LIGHT SIDE AT A FEW TENTHS OF AN INCH OR
LESS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 335 AM CST SUN DEC 1 2013
LIFT AND MOISTURE WILL BECOME DEEPER MONDAY INTO WEDNESDAY AS THE
CORE OF THE MID LEVEL TROUGH APPROACHES THE REGION. FOR
MONDAY...THE MAIN FOCUS CONTINUES TO BE ALONG THE NOSE OF THE LOW
LEVEL WARM AIR ADVECTION AND WHERE IT WILL SET UP. ALL OF THE
01.00Z GUIDANCE SHOW THE BAND OF PRECIPITATION EXPANDING THROUGH
THE DAY AS THIS ADVECTION STRENGTHENS. HOWEVER...AS WARMER AIR
COMES IN AT THE LOW LEVELS...SOME PRECIPITATION TYPE ISSUES ARISE
WITH THE WARM LAYER POSSIBLY CAUSING THE SNOW TO CHANGE OVER TO
RAIN. SURFACE TEMPERATURES SHOULD ALSO BE ON THE RISE ABOVE
FREEZING...SO AM NOT EXPECTING ANY FREEZING RAIN AT THE MOMENT.
THERE IS SOME UNCERTAINTY TOO WITH THE POSITION OF THE NORTHWEST
TO SOUTHEAST SWATH OF PRECIPITATION WITH THE 01.00Z NAM/01.03Z
SREF BEING THE FARTHEST NORTHEAST WHILE THE 01.00Z GFS/ECMWF
DEVELOP IS MORE TO THE SOUTHWEST IN SOUTHEAST MINNESOTA/NORTHEAST
IOWA. MAY BE UNDER-DOING THE SNOW AMOUNTS ON MONDAY...BUT THE
POTENTIAL MIX HAS ME CAUTIOUS TO GO MUCH ABOVE A FEW TENTHS OF AN
INCH.
THE BIGGEST STORY WITH THE 01.00Z GUIDANCE IS HOW THEY HAVE ALL
COME AROUND TO THIS THINKING OF A MUCH FASTER FRONTAL PASSAGE WITH
THE DEEPENING SURFACE LOW/MID LEVEL TROUGH MOVING THROUGH EARLY ON
WEDNESDAY. THE BEST CHANCES FOR ANY PRECIPITATION APPEARS TO BE
FROM MONDAY NIGHT THROUGH WEDNESDAY AS THIS TROUGH APPROACHES. THE
WARMER AIR COMING IN ON TUESDAY AHEAD OF THE SYSTEM SHOULD KEEP
THE P-TYPE MAINLY AS RAIN UNTIL THE COLD FRONT COMES THROUGH EARLY
ON WEDNESDAY. THE MAIN CHANCES FOR SNOW WILL BE ON MONDAY NIGHT
AHEAD OF THE WARM AIR..AND THEN AGAIN ON WEDNESDAY MORNING BETWEEN
THE LEAD COLD FRONT PASSAGE AND THE SECONDARY COLD FRONT WHICH
USHERS IN THE DRASTICALLY COLDER AIR IN. OVERALL...CONFIDENCE IN
GETTING ANY SPECIFIC DETAILS DOWN ON THE PRECIPITATION TRENDS IS
PRETTY LOW...PARTICULARLY WITH THE SNOW AMOUNTS. IF ANY SNOW IS
ABLE TO OCCUR WEDNESDAY MORNING AFTER THE FIRST FRONT COMES
THROUGH...IT WILL MEAN THAT TEMPERATURES COULD BE COLDER THAN
ADVERTISED GOING THROUGH THE REST OF THE WEEK. DUE TO THE FASTER
FROPA...HAVE DROPPED THE PRECIPITATION CHANCES FROM THURSDAY
INTO THE WEEKEND.
AS FOR THE COLD SPELL...850MB TEMPERATURES ARE FORECAST TO DROP
DOWN TO BETWEEN -15 TO -20C ON THURSDAY WITH THE POOL OF COLD AIR
LASTING THROUGHOUT THE REGION PAST NEXT WEEKEND. EVEN IF THERE IS
NO SNOW COVER DOWN ON THE GROUND...TEMPERATURES WILL BE MUCH
BELOW NORMAL THROUGH THE FORESEEABLE FUTURE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1146 AM CST SUN DEC 1 2013
AS WEAK WARM AIR ADVECTION DEVELOPS ACROSS THE AREA THIS
AFTERNOON A BROKEN 8-10K FOOT DECK OF CLOUDS WILL SPREAD ACROSS
THE AREA. THESE CLOUDS HAVE ALREADY MOVED INTO KRST AND WILL MOVE
INTO KLSE AROUND 01.21Z. THESE CLOUDS WILL GRADUALLY DROP INTO THE
4 TO 8K RANGE OVERNIGHT...AND THEN KRST WILL SEE A BKN015 DECK
DEVELOP AROUND 02.16Z.
WITH THE MODELS CONTINUING TO STRUGGLE ON WHERE THE PRECIPITATION
WILL OCCUR...DID NOT INCLUDE THEM IN EITHER TAF SITE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1101 AM CST SUN DEC 1 2013
.UPDATE...
CLOUDS OVER THE LAKE ARE GRADUALLY SWINGING WESTWARD ONTO THE
SHORELINE. RAP AND NAM 1000-850MB WIND DIRECTION AND RH DEPICT THIS
WELL. AT THIS TIME...THE CLOUDS APPEAR TO BE MIXING OUT A LITTLE
OVER LAND. EXPECTING THE CLOUDS TO PUSH A LITTLE FURTHER INLAND
LATER THIS AFTERNOON AS FLOW TURNS NNE.
TEMPERATURES ARE A LITTLE TRICKY TODAY. THEY ARE ALREADY CLOSE TO
REACHING THE FCST MAX TEMP...BUT 925MB TEMPS WILL REMAIN STEADY
AROUND -3C TODAY. THEREFORE...WILL LEAVE MAX TEMPS ALONE...IN THE
UPPER 30S.
&&
.AVIATION/18Z TAFS/...
LAKE CLOUDS ARE STARTING TO SHIFT WESTWARD ONTO THE SOUTHEAST WI
SHORELINE. CIGS ARE 1400-2500 FEET. EXPECT THESE TO AFFECT MKE...RAC
AND ENW THROUGH MUCH OF THE AFTERNOON.
FLOW IS EXPECTED TO SHIFT NORTHEAST THEN EAST TONIGHT SO STRATUS
FROM NORTHERN WI AND OVER THE LAKE ARE EXPECTED TO SPREAD INTO
SOUTHEAST WI AND POSSIBLY SOUTH CENTRAL WI TONIGHT. UNCERTAINTY
ABOUT CLOUD BASES...BUT PLANNING ON VFR INLAND AND MVFR NEAR THE
SHORELINE FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 330 AM CST SUN DEC 1 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH
NAM BRINGS STRATUS FIELD OVER EAST CENTRAL WI SWD THROUGH ERN WI AND
OVER LAKE MI THROUGH THE MORNING. ONCE ESTABLISHED IT WILL LIKELY BE
DIFFICULT TO ERODE ESPECIALLY NEAR LAKE MI DUE TO THE DEVELOPING
INSTABILITY OVER LAKE MI. THE INSTABILITY OVER THE LAKE WILL
CONTRIBUTE TO CLOUDS BUT NOT ENOUGH FOR PCPN. OVER SOUTH CENTRAL
WI...WILL BE EXPECTING A PARTLY CLOUDY AND NICE DAY...HOWEVER THE
WESTERN EXTENT OF THE EXPECTED STRATUS IS UNCERTAIN. HIGH PRESSURE
CURRENTLY MOVING INTO MN WILL ARRIVE BY THIS EVENING. MIDDLE TO HIGH
CLOUDS TO THEN INCREASE TONIGHT AS A SHORTWAVE TROUGH APPROACHES
FROM THE WEST. NO PCPN IS EXPECTED UNTIL MONDAY OR MONDAY NIGHT.
TEMPS NEAR NORMAL TODAY AND ABOVE NORMAL FOR TNT GIVEN EXPECTED
CLOUDS.
MONDAY - CONFIDENCE...MEDIUM
SUBSIDING INFLUENCE OF HIGH DRIFTS EAST WITH DEVELOPING WAA. WEAK
WAVE IN THE FLOW STILL GENERATED LIGHT QPF ON THE 12Z ECMWF IN THE
FAR SE. HOWEVER 00Z RUN HAS DRIED IT OUT CONVERTING WI DURING THE
MORNING SO WILL RETAIN SOME SMALL POPS FOR THIS. HOWEVER GFS AND
NAM BOTH DRY AND ECMWF APPEARS TO BE A LITTLE LESS IMPRESSIVE WITH
THIS. STILL WORTH A MENTION NONETHELESS. DURING THE AFTERNOON THE
00Z NAM AND 00Z GFS SHOW A PRONOUNCED UPSWING IN ISENTROPIC LIFT
INTO SRN WI...ESP SC WI. THE ECMWF IS SLOWER ON ERODING THE LOW
LEVEL THERMAL TROUGH AND SHOWS ALL QPF TIED TO THIS LIFT ACROSS IA
AND MN. THE GFS IS THE COMPROMISE APPROACH KEEPING THE BETTER
POTENTIAL ACROSS THE WESTERN CWA.
MONDAY NIGHT - CONFIDENCE...LOW TO MEDIUM
WARM AIR ADVECTION CONTINUES THIS PERIOD. THE 00Z NAM AND 00Z GFS
ARE MORE AGGRESSIVE WITH LIFTING THE WARMER TEMPERATURES NORTH.
MEANWHILE THE 12Z ECMWF SUGGESTS A SLOWER ARRIVAL OF THE WAA
PRECIP WITH THE COLDER PROFILE LINGERING LONGER. THE 00Z HAS
WARMED UP SOME BUT NOT AS MUCH AS THE NAM AND GFS SUGGEST.
TUESDAY - CONFIDENCE...MEDIUM
00Z NAM AND 00Z GFS BOTH SHOW WARM CONVEYOR WELL ENTRENCHED AHEAD
OF THE PLAINS LOW. 12Z ECMWF SHOWED A SLOWER SOLUTION WITH 850
TEMPS 5-8 DEGREES COLDER AND STILL IMPLYING A LINGERING MIX
POTENTIAL WHILE GFS AND NAM CLEARLY FAVOR ALL RAIN. THE NEW 00Z
ECMWF HAS WARMED CONSIDERABLY CONVERGING ON THE NAM AND GFS
SOLUTION. SO WILL TREND ANY MIX OVER TO RAIN FOR THE AFTERNOON.
WEDNESDAY AND WEDNESDAY NIGHT - CONFIDENCE...LOW
WHILE THE 00Z ECMWF HAS TRENDED FASTER ON THE FRONTAL
TIMING...THE GFS STILL REMAINS MUCH QUICKER WITH COLD ADVECTION
WELL UNDERWAY. THE ECMWF AND NAM SHOW THE MILD AIR LINGERING AT
LEAST THROUGH THE MORNING BEFORE THE FRONT ARRIVES TOWARDS MIDDAY.
SO HIGHS MAY END UP BEING IN THE MORNING PRIOR TO FRONTAL PASSAGE.
HOWEVER IF THE TREND OF THE ECMWF PLAYING CATCHUP TO THE GFS
CONTINUES...THEN THE DAY COULD END UP STARTING ON THE CHILLY SIDE.
FOR NOW WILL LEAN TO THE WARM WEDGE AT LEAST HAVING A SAY FOR A
PART OF THE DAY. 00Z ECMWF DOES SHOW SOME LIGHT SNOW POTENTIAL
WEDNESDAY NIGHT WITH SECONDARY FEATURE WITH AN UPTICK IN 700-300
MILLIBAR Q-VECTOR CONVERGENCE SO WILL RETAIN A SMALL CHANCE OF -SN
FOR WEDNESDAY NIGHT.
THURSDAY THROUGH SATURDAY - CONFIDENCE...MEDIUM
STEADY COLD ADVECTION FOR THIS PERIOD. COLDEST AIR ARRIVES
SATURDAY WITH 925 TEMPS -15 TO -20C. MOST OF THE CWA LOOKS TRAPPED
IN THE TEENS FOR HIGHS ON SATURDAY.
AVIATION/12Z TAFS/...STRATUS FIELD WITH CIGS OF 1.0-3.0 KFT
CONTINUES TO MOVE STEADILY SWD FROM NE WI INTO EAST CENTRAL WI. THE
NAM DOES BRING THE STRATUS FIELD INTO EAST CENTRAL AND SE WI FOR
TODAY AND TNT AND FOLLOWED THIS SCENARIO. LESS UNCERTAINTY OVER
SOUTH CENTRAL WI SINCE STRATUS HAS HALTED OVER CENTRAL AND NW WI AND
MODELS INDICATE A MUCH LOWER POTENTIAL OF STRATUS THERE. WILL GO
WITH FEW-SCT STRATUS AT KMSN THROUGH THE PERIOD.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
MONDAY THROUGH SATURDAY...COLLAR