Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/21/13
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
345 PM PST Wed Nov 20 2013
.Synopsis...
Moist Pacific storm will continue the threat of precipitation
into early Thursday. Strong easterly winds over the Sierra and
gusty northerly winds elsewhere are expected behind this system
Thursday into Saturday. Benign weather returns for later in the
weekend and into next week.
&&
.Discussion...
Area radars show two features impacting NorCal this afternoon as
an upper trough moves onshore. First, a vigorous batch of
moisture has pushed through the Bay Area and into the Northern
San Joaquin Valley. Thunderstorm activity has been fairly limited
as expected, with only a few lightning strikes in the more
convective cells on the southern side of the precip band. The
main threat with these few embedded thunderstorms is heavy rain.
The HRRR model has a good handle on the whole area of precip, and
continues its track into the Motherlode and Sierra by early this
evening. Meanwhile, colder air should bring snow levels down as
low as 6000ft. At this time, it appears the heavier snow (3-6 or
more") would be south of Highway 50, in an area where most passes
are now closed. For now, will handle snow possibility with short
term statements. Heavy precip over the large burn scar from the
Rim Fire remains a concern.
The other area of interest on regional radars is a circulation
center currently over the Eureka area. High res models show this
area of precip shifting southeastward overnight, bringing a
lingering chance of showers to the area. Radar returns are much
lighter with this feature so additional moderate to heavy precip
is not expected.
Shower activity should subside by mid-day tomorrow as the trough
pulls eastward. A few lingering showers are possible into the
afternoon along the Sierra, but mostly east of the Sierra Crest.
Clearing skies are expected by the afternoon.
Focus turns to the potential for strong winds over much of the
area by tomorrow afternoon as CAA ensues and tight pressure
gradients setup across the region. A roughly north-south MSLP
gradients sets up across the valley and coastal mountains, with
more of an east-west gradient of the Sierra. In addition to
surface gradients, 700mb winds are progged to strengthen
significantly as the trough closes off into a closed low over
SoCal and the flow over our area turns to northeasterly. The
NAEFS shows this area of elevated 850mb-700mb winds running about
5 standard deviations from the average for the east-west
component of the wind (in other words, the strongest east-west
winds the model has seen in its 30 year record). Expecting
advisory-level winds in the Sac Valley (mostly on the west side
of the valley), Delta area, Lake County vicinity, and foothills.
Valley winds look to be the strongest tomorrow, while the Delta
and Clearlake areas could see lingering winds into Friday. While
the winds speeds will not be unusual for the Delta, the northerly
direction may cause greater impact since it is not as common.
Over the Sierra, very strong winds are expected late tomorrow
through early Saturday. A cross section of the NAM12 shows the
strongest winds from the crest westward down to around 5000ft.
Latest guidance supports warning-criteria winds (>50 MPH),
bringing the possibility of downed trees and local power outages.
Meteorologically, this event looks to be similar to Nov 30th
2011, wherein strong winds led to toppled trees in the higher
Sierra.
Dry and benign weather returns Sunday as a the SoCal low shifts
eastward and a ridge builds in along the West Coast. Temperatures
across the area look to return to around normal for this time of
year. -DVC
.Extended Discussion (Sunday through Wednesday)
A high pressure ridge aloft will slide over the West Coast
through the extended period bringing dry conditions and continued
fair skies. Light pressure gradients at the surface and aloft will
keep winds generally light. The upper ridge axis will shift east
by early next week. Longer range models are indicating the
potential of a low pressure system approaching California around
Thanksgiving. Confidence is low in the details at this time
however.
Dang
&&
.Aviation...
Low pressure system currently over the region, bringing scattered
showers and poor flying conditions today. Widespread MVFR/IFR
conditions in the Valley will gradually improve to VFR/MVFR
tonight. Over the mountains, IFR/LIFR conditions will continue
for much of the next 24 hours with snow levels between 6000-7000
ft. There will be a slight chance of TSRA in the Valley generally
south of KSMF through early evening.
Winds will be south 5-15 kt today, becoming light tonight, then
shifting to the north 15-25 kt with local gusts up to 40 kt
Thursday.
An Airport Weather Warning has been issued for the Redding
Airport for gusty north winds Thursday.
Dang
&&
.STO Watches/Warnings/Advisories...
High wind warning from 7 PM Thursday to 4 AM PST Saturday West
Slope Northern Sierra Nevada...Western Plumas County/Lassen Park.
Wind advisory from 10 AM Thursday to 7 PM PST Friday Carquinez
Strait and Delta.
Wind advisory from 10 AM to 7 PM PST Thursday Central Sacramento
Valley...Northern Sacramento Valley...Southern Sacramento Valley.
Wind advisory from 7 PM Thursday to 4 AM PST Saturday
Motherlode...Northeast Foothills/Sacramento Valley.
Wind advisory from 7 PM Thursday to 7 PM PST Friday Clear
Lake/Southern Lake County.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
358 AM PST Tue Nov 19 2013
.Synopsis...
A moist system from the Pacific Ocean will continue widespread
precipitation across interior northern California through the
middle of the week.
&&
.Discussion...
Strong zonal flow continues over the EPAC with 120-130 kt upper
jet aligned along and south of 40N. Initial frontal band and
moisture plume (TPW of 1 to 1.25 inches) has moved inland across
NORCAL overnight, but its progress southward is stalling. Much of
the northern half of the Sacramento Valley has received 1 to 2
tenths of an inch of rain since Monday evening while the
mountains to the north of Redding have seen around 1/4 to 1/2
inch. Areas further to the south including the Sacramento area
have seen much lighter rainfall amounts with only a trace to a few
hundredths of an inch reported so far.
Snow levels will start out around 6000 to 6500 feet early this
morning, but are expected to rise over 7000 to 7500 feet later
today as warm advection increases and drier air is mixed out. The
higher elevation northern Sierra passes may see an inch or so of
slushy accumulation today.
Appears and front and moisture plume will stall out over the area
today, and with weak forcing only light amounts of QPF are
expected. Hi-res HRRR indicates a brief break early this morning
over the southern Sacramento Valley with more light precip
spreading into the region around 16Z. Some enhancement of precip
is expected by late this afternoon into Wednesday as the next
short-wave approaches leading to a little stronger lift across the
region.
Front forecast to shift south of the region Wednesday as a
stronger short-wave moves through. Precip expected to turn more
showery across the region, and appears there may be a chance for
thunderstorms across the southern half of the forecast area as the
short-wave moves through during the middle of the day.
Snow levels expected to remain high (generally at or above 7000
feet through Wednesday), so significant snow accumulation will be
limited to the crest of the northern Sierra. 60 hour snow
accumulations from today into early Thursday may approach 10
inches around the 8000 ft level and above.
Showers are expected to end over much of the interior of NORCAL
by early Thursday as the trough digs southward and closes off
vicinity of SOCAL. There may be some lingering showers through the
day along the northern Sierra crest south of Lake Tahoe due to
cyclonic (or backwash) flow of the upper low. By the end of the
day on THU...anticyclonic flow aloft over the nrn portion of the
CWA should begin to clear/erode cloud cover.
With moist ground and ridging developing late in the week...we
would be thinking about valley stratus/fog. However...at this time
strong enough pressure gradients should result in a katabatic wind
precluding fog/stratus formation most areas.
&&
.Extended Discussion (Saturday through Tuesday)...
Areas breezy to windy northeast to east winds continue over
interior NorCal Saturday as positively tilted upper ridge builds
inland. Pressure gradient weakens Sunday with lighter wind. Upper
ridge persists over Northern Cal through the weekend into early
next week bringing dry weather with slightly above normal
temperatures.
&&
.Aviation...
Wdsprd MVFR/IFR conds tda into Wed in pcpn with lcl LIFR omtns.
Snow lvls genly aoa 060. Isold tstms poss ovr srn hlf of fcst area
Wed aftn. W flow alf with Sly wnds up to 20 kts nr sfc tda into
tngt with Lcl SW sfc wnd gsts up to 35 kts ovr hyr mtn trrn.
&&
.STO Watches/Warnings/Advisories...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
311 PM MST TUE NOV 19 2013
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 310 PM MST TUE NOV 19 2013
MOIST LOW AMPLITUDE SHORT WAVE RACES ACROSS NORTHWEST COLORADO
TONIGHT. RADAR SHOWING LOW DBZ RETURNS AS THE MOISTURE INCREASES
THIS AFTERNOON...SOME OF THIS PCPN IS REACHING THE GROUND AS KCAG
MEASURED A TRACE AND SUNLIGHT MOUNTAIN AWOS REPORTS LIGHT SNOW.
THE COMBINATION OF OROGRAPHICS AND WEAK DYNAMICAL FORCING WILL
RESULT IN WIDESPREAD LIGHT PCPN OVERNIGHT ACROSS NW COLORADO...POSSIBLY
EXTENDING AS FAR SOUTH AS THE ELK MOUNTAINS. ENHANCED CLOUD COVER
IN THE INFRARED IS SOMEWHAT FRAGMENTED AND UPSTREAM RADAR
OBSERVATIONS SHOW BROKEN AREAS OF PCPN. THE RAP MODEL SHOW PCPN
EXPANDING AS THE SHORT WAVE GETS LIFTED OVER THE DIVIDE...BUT
APPEARS THAT THE TIME DURATION DOES NOT LAST LONG ENOUGH FOR
ADVISORY CRITERIA SNOWFALL. APPEARS THE ELKHEADS AND PARK RANGE
MAY GET A FEW INCHES OF SNOW TONIGHT...BUT TAPERING OFF AFTER
MIDNIGHT. THE SRN HALF HALF GETS EXTENSIVE CLOUD COVER BUT THE
MOISTURE IS NOT AS DEEP...FLURRIES OR BRIEF LIGHT SNOW MAY OCCUR
OVER THE SAN JUAN MOUNTAINS AS THE SHORT WAVE DRAGS ACROSS WRN
COLORADO.
SATELLITE INFRARED AND WATER VAPOR CLEARLY SHOWS A STREAM OF
MOISTURE FROM NW OF THE HAWAIIAN ISLES TO THE CALIFORNIA COAST.
THE FORECAST AREA MAY GET ONLY ONE SHOT AT THIS MOISTURE AND THAT
OCCURS FROM WEDNESDAY AFTERNOON INTO THURSDAY. BUT SHORT WAVE
ENERGY ADVECTING THIS MOISTURE TO THE FOUR CORNERS REGION IS WEAK
AND FRAGMENTED (SIMILAR TO THE LEAD SHORT WAVE). NO SHORTAGE OF
MOISTURE AS 700 MB SPECIFIC HUMIDITY VALUES EXCEED 4 G/KG...BUT
OTHER FEATURES THAT ARE NEEDED FOR EFFICIENT RAIN OR SNOW PRODUCTION
ARE MISSING. LACKING ELEMENTS INCLUDE BAROCLINICITY AND
DYNAMICAL/OROGRAPHICAL FORCING AS 700 MB GRADIENT FLOW IS LESS
THAN 20 KNOTS. THE AREA OF PRECIPITATION WILL BE EXPANDING
WEDNESDAY AFTERNOON OVER SW COLORADO AND SPREADING NEWD...CURRENT
QPF PROJECTIONS SUGGEST SNOW POTENTIAL OF 4 TO 8 INCHES OVER THE
SAN JUAN AND WRN COLORADO CENTRAL MOUNTAINS. THE DEEPEST MOISTURE
WILL BE POSITIONED ACROSS THE REGION ON WEDNESDAY NIGHT BEFORE
SHIFTING DOWNSTREAM BY THURSDAY MORNING...NOT COINCIDING WITH THE
COLD FRONT SURGING SOUTHWARD NEAR THE WYOMING BORDER. SNOW LEVELS
A BIT TRICKY AND WILL BE FLUCTUATING DEPENDING ON TIME OF DAY. IN
GENERAL TERMS...SNOW LEVELS WILL RANGE FROM 7000 TO 8000 FEET.
DIABATIC COOLING PROCESSES COULD RESULT IN WET SNOW TO NEAR THE
VALLEY FLOORS LATE WEDNESDAY NIGHT. LATER SHIFTS MAY NEED TO
CONSIDER HOISTING WINTER WEATHER ADVISORIES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 310 PM MST TUE NOV 19 2013
BY THU THE SPLIT IN THE FLOW WILL BECOME MORE DISTINCT AS THE LOW
BEGINS TO CLOSE OFF ROUGHLY OVER SOUTHERN CALIFORNIA. A MOIST AND
UNSETTLED SOUTHWEST FLOW AHEAD OF THE LOW WILL CONTINUE TO STREAM
OVER THE SOUTHWEST CORNER OF THE CONUS...AND ACROSS THE SOUTHERN
AND CENTRAL ROCKIES. IN ADDITION...A COLD FRONT ASSOCIATED WITH A
NORTHERN BRANCH SHORTWAVE WILL DROP INTO THE NORTHERN EDGE OF THE
CWA BY AROUND MIDDAY. WE CAN EXPECT MOUNTAIN SNOW AND THE CHANCE
FOR VALLEY RAIN TO CONTINUE THROUGH THU. MOST OF THE AREA WILL BE
DOMINATED BY THE MOIST UNSTABLE SOUTHWEST FLOW WITH SOUTH-
SOUTHWEST SLOPES FAVORED IN THIS REGIME. BUT THE OROGRAPHICS WILL
GENERALLY REMAIN ON THE WEAK SIDE AS THE SOUTHWEST FLOW IS NOT
EXPECTED TO BE OVERLY STRONG. OVER THE FAR NORTH HOWEVER...THE
AREA IMPACTED BY THE THE NORTHERN BRANCH COLD FRONT WILL SPREAD
SOUTH/SOUTHEAST. I EXPECT THAT THERE WILL BE A NICE ENHANCEMENT OF
THE PRECIPITATION IN THE VICINITY OF THE FRONT. BUT MODELS
INDICATE MUCH DRIER AIR WILL PUSH IN BEHIND THE FRONT. THIS WILL
BRING A DOWNTURN IN POPS OVER THE NORTHWEST CORNER BY LATE IN THE
AFTERNOON WITH THAT TREND EXTENDING SOUTH-SOUTHWEST THROUGH THE
EVENING. ALSO A LOCALIZED AREA OF STRONG NORTHERLY WINDS WILL
DEVELOP OVER WESTERN MOFFAT COUNTY INTO THE EASTERN UINTA BASIN
DURING THE EVENING. MUCH COLDER TEMPS WILL RESULT IN THIS DRIER
AIR BEHIND THE FRONT. MODELS DISAGREE ON JUST HOW FAR SOUTH THIS
FRONT WILL REACH BEFORE IT WASHES OUT IN THE SOUTHWEST FLOW AHEAD
OF THE SOUTHERN BRANCH LOW. BUT WE CAN CERTAINLY EXPECT MUCH
COLDER TEMPS OVER THE FAR NORTH...WITH LESS COOLING AS ONE TRAVELS
SOUTH.
MODELS AGREE THAT THE LOW WILL STALL IN THE VICINITY OF SAN DIEGO
BY EARLY FRIDAY...THEN PRETTY MUCH REMAIN STATIONARY UNTIL EARLY
SUNDAY. BY SUN AFTERNOON THE LOW BEGINS TO SLOWLY SHIFT
EAST...MAKING IT OVER NM/GFS...TO THE OK PANHANDLE/ECMWF ON
MONDAY. THIS KEEPS THE DESERT SOUTHWEST THROUGH THE SOUTHERN CO
MOUNTAINS UNDER A MOIST UNSETTLED FLOW AHEAD OF THIS LOW...AND
STILL UNSETTLED AS IT PASSES. OVER THE NORTH...MODELS SHOW A COL
AREA BETWEEN THE SOUTHERN BRANCH LOW AND THE NORTHERN BRANCH
NORTHWESTERLIES WILL MORE OR LESS SET UP OVER WY/NORTHERN CO...AND
EXTEND INTO NORTHEAST UT. THIS WILL KEEP THE NORTHERN HALF TO
TWO/THIRDS OF THE CWA ON THE DRY SIDE. BUT OUR SOUTHERN EDGE MAY
CONTINUE TO SEE PRECIPITATION TROUGH MONDAY. EXPECT THERE WILL BE
BREAKS AT TIMES. AND AS ANY EMBEDDED DISTURBANCES MOVE INTO THE
THE AREA... SHOWERS WILL BE ENHANCED.
MODELS ALL AGREE THAT BY TUE...A DRIER NORTH-NORTHWEST FLOW WILL
DOMINATE AREA-WIDE AS A LARGE AREA OF HIGH PRESSURE BUILDS TO OUR
WEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 310 PM MST TUE NOV 19 2013
MOUNTAIN TOPS WILL BE FREQUENTLY OBSCURED THROUGH THE NIGHT WITH
WIDESPREAD -RA/-SN NORTH OF A LINE FROM KVEL-KRIL-KASE-K7BM. AREAS
OF IFR CIGS/VIS WILL BE POSSIBLE NORTH OF THIS LINE. SNOW LEVELS
WILL BE LOWERING TO NEAR THE VALLEY FLOORS OR AROUND 5500 FEET.
VFR WITH AREA OF MVFR IS EXPECTED TONIGHT SOUTH OF A LINE FROM
KVEL-KGJT-KMTJ-KGUC. MOUNTAIN AREAS MAY BE PARTLY OBSCURED TONIGHT.
AFTER 12Z WEDNESDAY...VFR ALL TAF SITES EXCEPT LOWERING CIGS IN
THE AFTERNOON.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...PF
LONG TERM...EH
AVIATION...PF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
610 PM EST WED NOV 20 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
THE OVERALL WEATHER PATTERN WILL REMAIN QUITE MESSY...MAKING THE
OVERALL FORECAST TRICKY OVER THE NEXT DAY. A LIGHT WET SNOW IS
EXPECTED ACROSS THE INTERIOR WEST THIS EVENING BEFORE A COLD FRONT
PUSHES INTO THE WESTERN CWA THURSDAY AFTERNOON.
LATE THIS AFTERNOON AND TONIGHT...MID-LEVEL SW FLOW AHEAD OF DEEP
TROUGHING DEVELOPING ACROSS CENTRAL CANADA WILL CONTINUE THROUGH
THURSDAY. AN ASSOCIATED SFC TROUGH ORIENTED ACROSS THE UPPER MS
VALLEY BETWEEN LOW PRESSURE OVER HUDSON BAY AND DEVELOPING LOW
PRESSURE ACROSS THE SOUTHERN HIGH PLAINS WILL SLOWLY PUSH EAST. A
WELL-DEFINED MID-LEVEL SHORTWAVE TROUGH CURRENTLY CENTERED NEAR
SIOUX FALLS WILL CONTINUE ITS NORTHEASTWARD PROGRESSION THIS EVENING
AND BE THE MAIN PLAYER IN PRECIPITATION.
MANY CONVOLUTED FORCING MECHANISMS WILL BE AT WORK THIS EVENING. A
COMPLICATED LOW-LEVEL FGEN PATTERN SLOPING TO THE SE WITH HEIGHT AND
A WEAK UPPER-LEVEL JET STREAK MERGING WITH THE POLAR JET WILL IMPOSE
CONFLICTING OMEGA FIELDS ON EACH OTHER. THIS WEAK UPPER JET STREAK
APPEARS TO BE SOME CONVECTIVE FEEDBACK TIED TO A CLUSTER OF
PERSISTENT STORMS OVER IA AND MO. MEANWHILE...WEAK ISENTROPIC ASCENT
ON THE 290-295K SFCS WILL ASSIST SOME MID-LEVEL PRECIP DEVELOPMENT
THIS EVENING. OVERALL...PRECIP LOOKS TO BE CONTROLLED BY THE
ISENTROPIC ASCENT AND Q-VECTOR CONV WITH THE MID-LEVEL WAVE.
A BROKEN SHIELD OF RAIN AND SNOW SHOWERS HAS DEVELOPED ACROSS
WESTERN WI OVER THE PAST SEVERAL HOURS. THIS HAS EASED SOME CONCERNS
THAT THE MIXED OMEGA FIELD WOULD SUPPRESS PRECIP. THE RAP HAS
MAINTAINED A DECENT HANDLE ON THE PRECIP EVOLUTION...SO HAVE
FOLLOWED IT FOR THE OVERALL PRECIP PATTERN WHILE EMPLOYING THE NAM
FOR THE SYNOPTIC EVOLUTION. PRECIP HAS JUST STARTED TO SPREAD INTO
THE INTERIOR WEST NEAR WI AND WILL CONTINUE NORTHWARD INTO THE
EVENING. THERE IS GOOD AGREEMENT THAT THE GREATEST COVERAGE WILL BE
MID TO LATE EVENING ACROSS MUCH OF THE WEST HALF OF THE CWA BEFORE
PRECIP SPREADS EASTWARD OVERNIGHT WITH THE WAVE.
PTYPE LOOKS TO BE MOSTLY WET SNOW FOR ALL BUT THE NEAR LAKE SUPERIOR
SHORELINE AS WETBULB ZERO LEVELS WILL BE WELL BELOW 1KFT. A SUB
700MB DRY LAYER MAY INHIBIT PRECIP INITIALLY...BUT GIVEN CURRENT
RADAR RETURNS IN WI...PRECIP RATES SHOULD BE HIGH ENOUGH TO OVERCOME
THE DRY AIR IN A HOUR OR SO. SNOW RATIOS SHOULD BE QUITE
LOW...GENERALLY 8-10:1 AS MOST LIFT WILL BE W/IN TEMPS HIGHER THAN
THE DGZ. SOME AGGREGATION COULD BE POSSIBLE THROUGH A DEEP
ISOTHERMAL LAYER BETWEEN -3 AND -5C...SO LARGER WET FLAKES ARE
POSSIBLE. TOTAL SNOWFALL THROUGH TONIGHT IS FORECAST TO BE 0.5-1.5
INCHES FOR THE INTERIOR WEST HALF...HIGHEST FROM IRON RIVER TO
CHAMPION. WOULD NOT BE SURPRISED IF SOME LOCATIONS TOP 2 INCHES
GIVEN THE HEAVIER SHOWER ACTIVITY EXPECTED. SHORELINE LOCATIONS WILL
SEE MINIMAL ACCUMULATION AS A RESULT OF LOWER ELEVATION AND
DOWNSLOPING WITH A GENERAL SOUTH WIND.
OVERALL PRECIP COVERAGE WILL DIMINISH SLOWLY AS THE SHIELD
PROGRESSES EASTWARD. HOWEVER...CONTINUED SOUTH TO SSW FLOW OFF LAKE
MI SHOULD YIELD A LAKE-ENHANCED BAND OF RAIN AND SNOW SHOWERS
ACROSS EASTERN DELTA INTO SCHOOLCRAFT COUNTIES. MEANWHILE...MINIMAL
FZDZ WILL BE POSSIBLE ACROSS THE FAR WEST LATE TONIGHT AS SOME
MID-LEVEL DRYING BEHIND THE SHORTWAVE LIMITS LIFT TO THE BARELY
SUB-FREEZING LOW-LEVELS.
THURSDAY...AN OVERALL LULL IN PRECIP IS EXPECTED THROUGH THURSDAY
MORNING BEHIND THE MID-LEVEL WAVE...BUT THE SFC TROUGH WILL BEGIN TO
TRACK ACROSS THE CWA DURING THE AFTERNOON ACROSS THE WEST. HIGH
TEMPS WILL BE FAIRLY EARLY IN THE DAY FOR THE WEST HALF...WITH
FALLING TEMPS THROUGHOUT THE AFTERNOON. HIGHER MOISTURE WITH THE
FRONT AND DROPPING TEMPS WILL INCREASE SNOW SHOWER COVERAGE
WEST...ESPECIALLY FOR THE HIGHER TERRAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
SPLIT FLOW PATTERN PERSISTS THROUGH LATE THIS WEEK THEN FLOW PATTERN
BECOMES PHASED THIS WEEKEND INTO INTO FIRST PART OF NEXT WEEK WHICH
ALLOWS COLDEST AIR OF THE SEASON TO ARRIVE. COUPLE OF SHORTWAVES AND
SMALLER JET STREAKS LIFT ACROSS THURSDAY NIGHT INTO FRIDAY. BEST
CHANCE OF SYNOPTIC PRECIPITATION OCCURS THURSDAY NIGHT...ESPECIALLY
OVER THE SOUTH AND EAST. THOUGH THERE COULD BE SOME MIXED RAIN AND
SNOW EARLY THURSDAY EVENING IN THE EAST...SOUNDINGS AND THICKNESSES
BEYOND THAT TIME INDICATE COLD AIR WILL STAY IN PLACE LEADING TO SNOW
AS ONLY PTYPE THROUGH THE THANKSGIVING HOLIDAY.
MAY SEE ENHANCEMENT TO SNOW OVER THE WEST AND NORTH THURSDAY NIGHT
AS TEMPS AT INVERSION TOP OR H85 FALL TO -8C TO -10C GIVING A DELTA
T TO AROUND 13C. MORE SIGNIFICANT CONTRIBUTION FROM THE LAKE
ENHANCEMENT MAY BE OVER HIGHER TERRAIN OF NCNTRL AS LARGER SCALE
FORCING FOR SNOW PERSISTS INTO DAYBREAK ON FRIDAY. A FEW INCHES OF
SNOW MAY OCCUR OVER THURSDAY NIGHT FOR HIGHER TERRAIN OF MARQUETTE
COUNTY AND FOR FAVORED INLAND SNOWBELTS OF WESTERN ALGER COUNTY.
ELSEWHERE SNOW AMOUNTS OF AN INCH OR TWO ARE POSSIBLE.
ARCTIC FRONT WILL BE BLASTING SOUTH ACROSS MANITOBA AND NORTHERN
ONTARIO ON FRIDAY BUT WILL NOT ARRIVE OVER UPR LAKES UNTIL FRIDAY
EVENING. SO...FRIDAY MAY END UP A FAIRLY QUIET BTWN SYSTEMS DAY AS
CWA WILL BE IN WAKE OF THURSDAY NIGHT WAVE AND STILL AHEAD OF ARCTIC
FRONT/STRONG COLD AIR ADVECTION/LK EFFECT SNOWS FOR LATER FRIDAY
NIGHT INTO THE WEEKEND. PARTIAL CLEARING MAY OCCUR BUT WITH LIMITED
WARM AIR ADVECTION AHEAD OF THE FRONT...TEMPS WILL SILL END UP IN
THE 20S. WINDS WILL BE ON THE LIGHTER SIDE COMPARED TO THE WINDY
CONDITIONS COMING FOR THE WEEKEND.
ARCTIC FRONT SWEEPS THROUGH ON FRIDAY NIGHT. TEMPS STARTING OUT THE
EVENING IN THE UPR 20S WILL BE SOLIDLY IN THE TEENS OVER THE WEST BY
DAYBREAK ON SATURDAY AND GOING NOWHERE FAST. TEMPS WILL STAY STEADY
OR FALL SLIGHTLY ON SATURDAY AS PLUNGE OF COLD AIR AT H85 AND H7
DRIVES ACROSS THE GREAT LAKES REGION. EXPECT LK EFFECT SNOWS TO RAMP
UP SIGNIFICANTLY. INTITAL BURST OF SNOW OCCURS FRIDAY EVENING OVER
THE KEWEENAW WITH SUFFICIENT OVERWATER INSTABILITY COMBINING WITH
LOW-LEVEL CONVERGENCE ALONG FRONT. SOUNDINGS INDICATE FAVORABLE
MOISTURE AND LOCATION OF DGZ INTERSECTING PROJECTED UVM. SLR/S
SHOULD INCREASE TO MORE OF A FLUFFY 15-20:1 WITH STRONG NW WINDS IN
BLYR ONLY THING PROHIBITING SLR/S WELL OVER 20:1. ONCE BURST OF
HEAVIER SNOW SLIDES ACROSS CWA WITH THE ARCTIC FRONT...EXPECT
PERIOD OF HEAVY NNW FLOW LK EFFECT THROUGH THE DAY. NNW WINDS IN
BLYR AND A STILL OPEN LK NIPEGON COULD LEAD TO HEAVIEST SNOW
SHOWERS SETTING UP BTWN MQT AND MUNISING. SNOW TOTALS LATER
FRIDAY NIGHT THROUGH SATURDAY WILL BE AT LEAST ADVY ALONG MUCH OF
LK SUPERIOR WITH SOME AREAS SEEING WARNING AMOUNTS OF 10 INCHES IN
12 HOURS. STRONG WINDS WITH THE FLUFFIER SNOW WILL RESULT IN AREAS
OF BLOWING SNOW/REDUCED VSBY. PRETTY CONFIDENT HEADLINES FOR THIS
EVENT WILL BE COMING IN THE NEXT COUPLE DAYS. FOR NOW...WILL KEEP
GRAPHICAL MENTION IN THE EHWO AND A MENTION IN HAZARDOUS WEATHER
OUTLOOK.
DEPARTING DEEPER MOISTURE AND LOWERING INVERSIONS/INCREASING
ANTICYCLONIC FLOW WITH ARRIVAL OF SFC RIDGE WILL PUT A CRIMP IN LK
EFFECT BY SATURDAY NIGHT. STILL MAY SEE ADVY AMOUNTS OVER THE EAST
THOUGH AS OVERWATER INSTABILITY REMAINS MORE THAN SUFFICIENT AND
THERE WILL LIKELY BE SOME UPTICK OF LOW-LEVEL CONVERGENCE AS WINDS
BACK MORE WESTERLY OVR LAND WITH THE ARRIVAL OF THE SFC RIDGE TOWARD
WESTERN UPR MICHIGAN. TRANSITION ON SUNDAY AS SFC RIDGE CROSSES.
COULD BE TRICKY SINCE COLD AIR LINGERS AND WINDS BECOME FAVORABLE
FOR LK EFFECT OFF LK MICHIGAN. INITIALLY WINDS HAVE ENOUGH SOUTHERLY
COMPONENT TO INCLUDE HIGHER POPS OVER MUCH OF SCHOOLCRAFT AND LUCE
COUNTIES...THEN EVENTUALLY ON SUNDAY NIGHT THE WINDS HAVE ENOUGH OF
A WESTERLY COMPONENT TO PUSH MOST OF MORE SIGNIFICANT LK EFFECT
FARTHER TO THE EAST. HOWEVER...CLIPPER LOW PRESSURE SYSTEM DROPPING
TO NORTH OF LK SUPERIOR WILL SPREAD ADDITIONAL SNOW ACROSS NORTHERN
AND EASTERN UPR MICHIGAN.
ANOTHER BOUT OF COLD AIR AND LK EFFECT LIKELY IN WAKE OF THAT
CLIPPER TUESDAY AND WEDNESDAY. ONCE AGAIN AREAS FAVORED BY NNW
FLOW OVER CNTRL AND EASTERN CWA WILL SEE THE BEST SHOT AT HEAVIER
SNOW. PLENTY OF TIME TO ASSESS THIS POTENTIAL ONCE WE GET PAST THE
WEEKEND LK EFFECT SNOWS. PEEK AHEAD TO THANKSGIVING SHOWS THE COLD
AIR PERSISTS WHILE LINGERING LK EFFECT RUNS ITS COURSE. SO...AT
LEAST AT THIS POINT...NO LARGE SCALE LOW PRESSURE SYSTEM/WIDESPREAD
SNOW EXPECTED FOR THE THANKSGIVING TIME FRAME. PROBABLY GOES WITHOUT
SAYING...BUT OBVIOUSLY THERE IS PLENTY OF TIME FOR THIS TO CHANGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 610 PM EST WED NOV 20 2013
MAIN IMPACTS AT ALL SITES WILL DEVELOP THIS EVENING AS PRECIP
SPREADS OVER THE AREA. EXPECT LIGHT SNOW THIS EVENING...MAINLY AT
IWD AND CMX. EXPECTATIONS ARE THAT -SN AT CMX AND IWD WILL ONLY
LOWER VIS AND CIGS TO LOW-END MVFR. THOUGH MOISTURE WILL BE
INCREASING AT ALL SITES AS PRECIP PASSES THROUGH...DOWNSLOPING WITH
GENERALLY SOUTH WINDS SHOULD KEEP CIGS MVFR THROUGH THE EVENING. IFR
CIGS SHOULD THEN DEVELOP AT IWD AND SAW OVERNIGHT AS WINDS BECOME
MORE SSW AND LOW-LEVEL MOISTURE INCREASES BEHIND THE PRECIP. ALL
SITES SHOULD SEE SOME CIG IMPROVEMENT THURSDAY MORNING WITH SOME
LOW-LEVEL DRYING AND MINIMAL LIFT. THE EXCEPTION WILL BE CMX...WHERE
AN APPROACHING COLD FRONT WILL BRING NW WINDS AND INCREASINGLY
UPSLOPE FLOW. LAKE EFFECT SNOW SHOWERS AND MVFR CONDITIONS EXPECTED
AT ALL TAF SITES THU AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST WED NOV 20 2013
SOUTHERLY WINDS OF UP TO 30 KNOTS FOR EASTERN LAKE SUPERIOR LATE
THIS AFTERNOON WILL DIMINISH TO LESS THAN 20 KNOTS BY THURSDAY
MORNING AS A COLD FRONT NEARS WESTERN LAKE SUPERIOR. THE COLD FRONT
IS EXPECTED TO CROSS LAKE SUPERIOR BEGINNING FAR WEST MID-THURSDAY
MORNING...AND REACHING THE FAR EAST THURSDAY EVENING. WINDS WILL
QUICKLY VEER TO THE NW AROUND 30 KNOTS FOR MUCH OF LAKE SUPERIOR
BEHIND THE FRONT. EXPECT THESE WINDS TO CONTINUE THROUGH THURSDAY
EVENING BEFORE DIMINISHING ON FRIDAY.
STRONG HIGH PRESSURE BUILDING ACROSS CENTRAL CANADA WILL BEGIN TO
IMPINGE ON LOW PRESSURE DEVELOPING OVER THE LOWER GREAT LAKES FRIDAY
AFTERNOON AND EVENING. WEST WINDS OF 20-30 KNOTS ACROSS WESTERN LAKE
SUPERIOR FRIDAY EVENING WILL BECOME NW GALES TO 35 KNOTS WEST TO NW
GALES TO 45 KNOTS EAST SATURDAY MORNING. THE WINDS WILL GRADUALLY
DIMINISH TO UNDER 20 KNOTS BY SUNDAY MORNING. WITH ARCTIC AIR MOVING
OVER THE LAKE...THERE IS A POTENTIAL FOR WIDESPREAD FREEZING SPRAY
SATURDAY AND SATURDAY NIGHT. THEN AN APPROACHING LOW PRESSURE FROM
CANADA WILL BACK WINDS SW TO 20-30 KNOTS BY MONDAY MORNING. ANOTHER
COLD FRONT WILL FOLLOW MONDAY AFTERNOON WITH 20-30 KNOTS NW WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY NIGHT
FOR LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KLUBER
LONG TERM...JLA
AVIATION...07
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
740 PM EST WED NOV 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WITH RAIN SHOWERS WILL MOVE THROUGH THE
REGION THURSDAY NIGHT AND FRIDAY. A STRONG COLD FRONT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT, WHICH WILL USHER IN MUCH COLDER
AIR STARTING SUNDAY. THIS COLD AIR COULD GENERATE SIGNIFICANT
LAKE EFFECT SNOWS IN THE LAKE EFFECT SNOW BELTS OF NORTH CENTRAL
NEW YORK.
&&
.NEAR TERM /THROUGH THURSDAY/...
745 PM UPDATE... ONLY MINOR TWEAKS WERE MADE TO THE GRIDS EARLY
THIS EVE...WITH OUR EXISTING FCST IN GOOD SHAPE.
SAT IMAGERY/SFC OBS ARE SHOWING THIN HIGH CLDNS CROSSING CNY/NE PA
THIS EVE. GIVEN SAT TRENDS UPSTREAM...WE THINK WE`LL CONTINUE TO
SEE SOME HIGH CLOUD COVER OVERNIGHT...BUT GIVEN ITS FAIRLY
TRANSPARENT NATURE...PTLY CLDY SEEMS LIKE A GOOD SKY COVER
DESCRIPTOR. THERE WAS SOME THINKING EARLIER TDY THAT A MARINE LYR
CLOUD DECK COULD SNEAK UP INTO OUR SERN ZNS BY...OR JUST AFTER
09Z THU. ALTHOUGH THERE IS SOME PATCHY SC ATTM ACRS SRN VA...WE
THINK THAT LWR CLDS WILL NOT MAKE IT TO NE PA BY DAYBREAK FOR SVRL
REASONS...LACK OF CLOUD DVLPMT/ONSHORE FLOW ATTM OVER MOST OF THE
DELMARVA RGN OR NJ...WEAK LOW-LVL FLOW...AND A VERY DRY RESIDENT
AMS IN THE BLYR (SFC DEW PTS NEAR 10F OVER MUCH OF ERN PA ATTM).
WE STILL FEEL CONFIDENT SOME OF OUR NORMALLY COLDER SHELTERED VLYS
WILL DROP INTO THE TEENS BY DAYBREAK. AS A RESULT...WE BASICALLY
LEFT OUR LOW TEMP FCST ALONE...AND JUST MASSAGED SOME NEAR-TERM
TEMPS AND DEW PTS THIS EVE.
PREV DISC... HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO
THIS EVENING AS THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT
ONLY SOME PATCHY CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS
WHICH WILL BE MOVG OVHD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD
EARLIER IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN
SPREADING EWRD AS THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE
MIN/S OCCURRING IN THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI
AM WHEN THE BULK OF THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND
IT. THEN THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT
WAVE APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE
TRUE ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR
SAT...IT LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS
AND FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL
BE A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EXTENDED FORECAST BEGINS WITH A VERY COLD AIRMASS ACROSS THE
NORTHEAST AS A DEEP UPPER LEVEL TROF SWINGS THROUGH THE AREA. BOTH
THE GFS/ECMWF CONTINUE TO ADVERTISE T85 AROUND -16C/-18C FOR 18Z
SUN. THEY BOTH HAVE BEEN CONSISTENT WITH THIS COLD AIRMASS FOR
SEVERAL RUNS NOW INDICATING A HIGH LIKELY HOOD OF OCCURRENCE.
INITIALLY THE LOW LEVEL FLOW SATURDAY NIGHT LOOKS AROUND 290
DEGREES THEN SHIFTS MORE NORTHWEST AFTER 06Z AS A SECONDARY TROF
PASSES. ON SUNDAY, THE LOW LEVEL FLOW WILL BACK AS H85 RIDGE MOVES
THROUGH THE AREA. FOR SATURDAY NIGHT THROUGH SUNDAY WILL CONTINUE
TO ADVERTISE LIKELY POPS FOR LES PRIMARILY SOUTHEAST OF LAKE
ONTARIO. SNOW ACCUMS THROUGH THE PERIOD WILL LIKELY REACH SEVERAL
INCHES WITH A LAKE SNOW ADVISORY MOST LIKELY NEEDED SATURDAY NIGHT
INTO SUNDAY AS THE EVENT APPROACHES. A SHORT FETCH AND LIMITED
SYNOPTIC MOISTURE MAY LIMIT ACCUMS BUT THE AIRMASS IS VERY COLD
FOR THIS TIME OF THE YEAR.
MONDAY NIGHT INTO WEDNESDAY, A NORTHERN STREAM SYSTEM WILL MOVE
THROUGH THE UPPER GREAT LAKES AND ACROSS EASTERN CANADA. WILL
MENTION CHC/SLIGHT CHC POPS FOR SNOW SHOWERS. THE MEDIUM RANGE
MODELS HAVE HINTED AT A NORTHERN/SOUTHERN STREAM PHASING TUE INTO
WED WITH THE DEVELOPMENT OF A STRONG COAST LOW WHICH COULD IMPACT
THE FORECAST AREA. THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF
NOW SHOW THE SYSTEM REMAINING PRIMARILY EAST/SOUTH OF THE AREA.
IT`S STILL EARLY, SOMETHING TO WATCH.
TEMPS THROUGH THE PERIOD WILL BE AROUND 10-15 DEGREES BELOW
NORMAL.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
630 PM UPDATE...
HIGH PRESSURE IN THE VCNTY WILL MOVE TO THE EAST COAST THURSDAY,
WHILE A COLD FRONT DROPS INTO THE UPPER GREAT LAKES. IN GENERAL
VFR CONDITIONS ARE EXPECTED TO CONTINUE. THROUGH MID MORNING
THURSDAY, JUST CI ACROSS THE TERMINALS WITH A MID DECK DEVELOPING
OVER THE AREA LATE IN THE TAF PERIOD.
TONIGHT EAST TO SOUTHEAST WINDS AT 5 KTS BECOMING SOUTH AT 8 KTS
STARTING 15Z THU.
OUTLOOK...
THURSDAY NIGHT INTO FRIDAY...MVFR AND POSSIBLY IFR RESTRICTIONS
LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT
SHSN...ESPECIALLY CENTRAL NY TERMINALS.
SUNDAY NIGHT AND MONDAY MORNING...VFR.
MONDAY AFTN...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS
TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN/MLJ
SHORT TERM...DJN
LONG TERM...RRM
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
633 PM EST WED NOV 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WITH RAIN SHOWERS WILL MOVE THROUGH THE
REGION THURSDAY NIGHT AND FRIDAY. A STRONG COLD FRONT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT, WHICH WILL USHER IN MUCH COLDER
AIR STARTING SUNDAY. THIS COLD AIR COULD GENERATE SIGNIFICANT
LAKE EFFECT SNOWS IN THE LAKE EFFECT SNOW BELTS OF NORTH CENTRAL
NEW YORK.
&&
.NEAR TERM /THROUGH THURSDAY/...
HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO THIS EVENING AS
THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT ONLY SOME PATCHY
CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS WHICH WILL BE MOVG
OHVD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD
EARLIER IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN
SPREADING EWRD AS THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE
MIN/S OCCURRING IN THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI
AM WHEN THE BULK OF THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND
IT. THEN THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT
WAVE APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE
TRUE ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR
SAT...IT LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS
AND FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL
BE A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EXTENDED FORECAST BEGINS WITH A VERY COLD AIRMASS ACROSS THE
NORTHEAST AS A DEEP UPPER LEVEL TROF SWINGS THROUGH THE AREA. BOTH
THE GFS/ECMWF CONTINUE TO ADVERTISE T85 AROUND -16C/-18C FOR 18Z
SUN. THEY BOTH HAVE BEEN CONSISTENT WITH THIS COLD AIRMASS FOR
SEVERAL RUNS NOW INDICATING A HIGH LIKELY HOOD OF OCCURRENCE.
INITIALLY THE LOW LEVEL FLOW SATURDAY NIGHT LOOKS AROUND 290
DEGREES THEN SHIFTS MORE NORTHWEST AFTER 06Z AS A SECONDARY TROF
PASSES. ON SUNDAY, THE LOW LEVEL FLOW WILL BACK AS H85 RIDGE MOVES
THROUGH THE AREA. FOR SATURDAY NIGHT THROUGH SUNDAY WILL CONTINUE
TO ADVERTISE LIKELY POPS FOR LES PRIMARILY SOUTHEAST OF LAKE
ONTARIO. SNOW ACCUMS THROUGH THE PERIOD WILL LIKELY REACH SEVERAL
INCHES WITH A LAKE SNOW ADVISORY MOST LIKELY NEEDED SATURDAY NIGHT
INTO SUNDAY AS THE EVENT APPROACHES. A SHORT FETCH AND LIMITED
SYNOPTIC MOISTURE MAY LIMIT ACCUMS BUT THE AIRMASS IS VERY COLD
FOR THIS TIME OF THE YEAR.
MONDAY NIGHT INTO WEDNESDAY, A NORTHERN STREAM SYSTEM WILL MOVE
THROUGH THE UPPER GREAT LAKES AND ACROSS EASTERN CANADA. WILL
MENTION CHC/SLIGHT CHC POPS FOR SNOW SHOWERS. THE MEDIUM RANGE
MODELS HAVE HINTED AT A NORTHERN/SOUTHERN STREAM PHASING TUE INTO
WED WITH THE DEVELOPMENT OF A STRONG COAST LOW WHICH COULD IMPACT
THE FORECAST AREA. THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF
NOW SHOW THE SYSTEM REMAINING PRIMARILY EAST/SOUTH OF THE AREA.
IT`S STILL EARLY, SOMETHING TO WATCH.
TEMPS THROUGH THE PERIOD WILL BE AROUND 10-15 DEGREES BELOW
NORMAL.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
630 PM UPDATE...
HIGH PRESSURE IN THE VCNTY WILL MOVE TO THE EAST COAST THURSDAY,
WHILE A COLD FRONT DROPS INTO THE UPPER GREAT LAKES. IN GENERAL
VFR CONDITIONS ARE EXPECTED TO CONTINUE. THROUGH MID MORNING
THURSDAY, JUST CI ACROSS THE TERMINALS WITH A MID DECK DEVELOPING
OVER THE AREA LATE IN THE TAF PERIOD.
TONIGHT EAST TO SOUTHEAST WINDS AT 5 KTS BECOMING SOUTH AT 8 KTS
STARTING 15Z THU.
OUTLOOK...
THURSDAY NIGHT INTO FRIDAY...MVFR AND POSSIBLY IFR RESTRICTIONS
LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT
SHSN...ESPECIALLY CENTRAL NY TERMINALS.
SUNDAY NIGHT AND MONDAY MORNING...VFR.
MONDAY AFTN...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS
TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...RRM
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
121 PM EST TUE NOV 19 2013
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS FLURRIES AND EVEN SOME PATCHY FREEZING
DRIZZLE WILL GRADUALLY COME TO AN END EARLY THIS AFTERNOON AS HIGH
PRESSURE SLOWLY BUILDS INTO THE REGION. BRISK NORTHWEST WINDS
COMBINED WITH ABUNDANT CLOUD COVER WILL KEEP TEMPERATURES MAINLY
IN THE MIDDLE TO UPPER 30S FOR DAYTIME HIGHS THIS AFTERNOON ACROSS
CENTRAL NEW YORK...WITH UPPER 30S TO LOWER 40S ACROSS NORTHEAST
PENNSYLVANIA. HIGH PRESSURE WILL THEN DOMINATE THE WEATHER PATTERN
WITH DRY AND SLOWLY MODERATING TEMPERATURES EXPECTED THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADARS STILL SHOW PERSISTENT LAKE EFFECT SNOW SHOWERS/FLURRIES AND
DRIZZLE OR EVEN FREEZING DRIZZLE DOWNWIND OF LAKE ONTARIO. THE
LOW-LEVEL FLOW WAS ABT FROM 310 DEGREES AND CONTS TO DIRECT LAKE
EFFECT MOISTURE INTO THE HILLS OF CENTRAL NY AND FAR NE PA AS OF
LATE THIS MORNING. MEANWHILE ALOFT THERE WAS STRG SYNOPTIC SCALE SUBSC
ASSCTD WITH THE PASSAGE OF THE UPPER LEVEL TROF AXIS TO THE EAST
INTO NEW ENGLAND.
MODEL SOUNDINGS BETWEEN THE NAM...GFS AND RAP DIVERGE AS TO HOW
THE BNDRY LAYER MOISTURE WILL EVOLVE THIS AFTERNOON INTO THE EVENING.
THE NAM RAPIDLY CLEARS OUT THE AREA THIS AFTERNOON WITH
SIGNIFICANT LL DRY AIR ADVECTION. THE RAP HOLDS ONTO THE MOISTURE
TRAPPED BELOW THE INVERSION INTO THE EVENING HOURS. THE GFS IS IN
BETWEEN. LOOKING AT THE VSBL SATELLITE IMAGERY I AM LEANING TWD
THE RAP AS THERE WAS SIGNIFICANT CLD CVR N OF LAKE ONTARIO IN ERN
ONT AND QUE. SFC DWPTS DO COME DOWN DURG THE AFTERNOON BUT THE
SATELLITE IMAGERY STILL SHOWS CLD CVR EVEN WITH THE DROP IN SFC
DWPTS UPSTREAM. THIS DRIER SFC AIR WILL ADVECT SOUTHWARD THIS
AFTERNOON AND SHUD SNUFF OUT THE LAKE EFFECT SNOW SHOWERS AND
DZ/FZDZ BY 19Z THE LATEST.
ISSUED AN SPS EARLIER FOR PATCHY FZDZ WHICH IS ASSCTD WITH THE
LAKE EFFECT MOISTURE. FZDZ WAS CONFIRMED BY SOME OF OUR FACEBOOK
FANS OVER THE HIGHER TERRAIN IN C NY. CLD TOPS OUTSIDE THE LAKE
EFFECT SNOW BANDS WERE TOO SHALLOW FOR GLACIATION AND HENCE WE ARE
SEEING SOME PATCHY DRIZZLE. HIGHER TERRAIN AREAS REMAIN AT OR
BELOW FREEZING WITH PATCHY FZDZ AT TIMES. WILL REISSUE SPS SHORTLY TO
HIGHLIGHT THE END OF THE FREEZING DRIZZLE AND PRECIP.
CLD CVR SHUD HANG ON DOWNWIND OF LAKE ONTARIO WELL INTO THE EVE AS
PER RAP SOUNDINGS. GIVEN THE NW FLOW AND TRAJECTORIES ACRS LAKE
ONTARIO AND PRESENT CLD CVR UPSTREAM FROM THE LAKES IN
CANADA...HARD TO SEE CLRG IN THE HILLS OF C NY OR FAR NE PA B4 6Z.
SO WILL HANG ONTO CLDS SIMILAR TO THE 925 MB RH FIELDS ON THE RAP.
EVENTUALLY LATER TONIGHT...THE FLOW TURNS MORE N-NERLY AND THIS
IS WHEN CLRG SHUD FINALLY TAKE PLACE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
A VERY QUIET SHORT TERM PERIOD ANTICIPATED AS HIGH PRESSURE
REMAINS IN FIRM CONTROL. BY WEDNESDAY...SE FLOW WILL INCREASE AS
HIGH PRESSURE SLIDES TO OUR EAST. EXPECT A WARMER DAY THAN TODAY
WITH MOST PLACES EXPECTED TO WARM INTO THE LWR TO MIDDLE 40S FOR
HIGHS. SIMILAR CONDITIONS EXPECTED ON THURSDAY AS 850-HPA TEMPS
SLOWLY BEGIN WARMING IN DEVELOPING SOUTHWEST FLOW ALOFT. PRECIP TO
MAKE A POSSIBLE RETURN THU NGT/EARLY FRI AS WARM AIR ADVECTION
INTERACTS WITH A NORTHWARD LIFTING WARM FRONT LIFTING NORTH
THROUGH THE OHIO VLY. FOR NOW...HAVE CAPPED POPS IN THE SLGT CHC
CATEGORY AS BEST ISENTROPIC ASCENT IS EXPECTED WELL WEST OF OUR
REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
115 PM TUE UPDATE...
GENERALLY USED WPC GUIDANCE EXCEPT FOR LOCALIZED ENHANCEMENTS TO
POP AND SKY GRIDS FOR WHEN LAKE EFFECT SNOW WILL BE FAVORABLE.
INTERESTING PATTERN TAKING SHAPE WITH INCREASING CONFIDENCE FOR
SOLID SHOT OF ARCTIC AIR /COLDEST OF SEASON SO FAR/ DURING SECOND
HALF OF WEEKEND...AND FOR LAKE EFFECT SNOW. DETAILS OF THAT SNOW
OF COURSE WILL BE RESOLVED IN COMING DAYS...BUT IN THE BIG PICTURE
IT LOOKS FAVORABLE WITHIN OUR GENERAL AREA AND FORECAST HAS BEEN
ADJUSTED ACCORDINGLY WITH BEST CHANCES SUNDAY IN CENTRAL NEW YORK.
BEFORE THEN HOWEVER...TIMING OF INITIAL COLD FRONT LOOKS LIKELY
FOR SOMETIME FRIDAY NIGHT/EARLY SATURDAY. FRONTAL PRECIPITATION
WILL PROBABLY BE MAINLY RAIN. COLD AIR ADVECTION OCCURS DURING THE
DAY...ALLOWING LINGERING RAIN SHOWERS TO MIX WITH SNOW...THOUGH
AMOUNTS PROBABLY LIMITED BY THEN DUE TO DRY SLOTTING /LOSS OF
DEEPER MOISTURE/. ARCTIC FRONT WILL THEN BLAST THROUGH SOMETIME
SATURDAY NIGHT...PLUMMETING 850MB TEMPERATURES INTO AT LEAST THE
MID TEENS BELOW ZERO ON SUNDAY. WITH THE ARCTIC AIR MASS APPEARING
TO ADVECT IN FROM WNW INSTEAD OF THE NORTHERLY DIRECTION...AND
WITH THE DENDRITIC GROWTH LAYER BECOMING COMFORTABLY CONTAINED IN
THE LOWEST 8 KFT AGL...IT IS A FAVORABLE SET UP FOR ACCUMULATING
LAKE EFFECT SNOW INCLUDING UPSTREAM LAKE-TO-LAKE CONNECTIONS
SUNDAY INTO PERHAPS SUNDAY NIGHT.
IT HAS BEEN COMMON SO FAR THIS SEASON FOR AN INITIALLY VERY COLD
AIR MASS IN THE MODELS...TO MODERATE AS THE EVENT GETS CLOSER TO
THE POINT THAT IT IS NOT QUITE AS COLD AS ORIGINALLY ANTICIPATED
ONCE IT ARRIVES. HOWEVER...IN THIS CASE...THE MODELS HAVE
INDICATED THE ARCTIC AIR FOR AT LEAST A FEW RUNS AND ARE
MAINTAINING ITS MAGNITUDE IF NOT TRENDING EVEN SLIGHTLY COLDER.
BOTH 12Z GFS AND 00Z ECMWF DIVE 1000-500MB THICKNESSES BELOW 510
DECAMETER RANGE. GFS GUIDANCE TEMPERATURES HAVE NOW TRENDED
TOWARDS THE VERY COLD ECMWF GUIDANCE VALUES. WE NOW EXPECT MOST
LOCATIONS NOT TO GET OUT OF THE 20S FOR HIGHS SUNDAY.
DRY SURFACE RIDGE MONDAY WITH WARM AIR ADVECTION ALOFT...BUT
LIKELY MUCH MORE MUTED AT THE SURFACE AS WOULD BE TYPICAL ON BACK
SIDE OF ARCTIC AIR MASS. SO AFTER MAINLY TEENS FOR LOWS SUNDAY
NIGHT...ONLY UPPER 20S TO MID 30S ANTICIPATED FOR HIGHS MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
18Z UPDATE...
DRY AIR IS TRYING TO FURTHER ENTRENCH INTO THE REGION...BUT
SHALLOW LAYER OF GREAT LAKES MOISTURE REMAINS TRAPPED UNDER
SUBSIDENCE INVERSION FOR AT LEAST A LITTLE LONGER. MVFR...IN SOME
CASES AT FUEL ALT REG LEVEL...WILL PESTER THE TERMINALS THIS
AFTERNOON THROUGH EVENING /SOME LONGER THAN OTHERS WITH TIMING AS
NOTED IN SPECIFIC TAFS/. LAKE EFFECT FLURRIES ALSO STILL POSSIBLE
INITIALLY FOR KITH-KBGM. NNW WINDS GUSTING TO 15-20 KTS THIS
AFTERNOON...THEN SUBSIDING TO LIGHT NE OR VARIABLE OVERNIGHT INTO
WEDNESDAY MORNING. AS THAT FLOW VEERS LIGHT NORTHEASTERLY
OVERNIGHT...ANY REMAINING MVFR CIGS WILL SCATTER OUT AND CLEAR.
VFR FOR REMAINDER OF TAF PERIOD AS HIGH PRESSURE TAKES CHARGE.
OUTLOOK...
WED THROUGH THU...VFR.
FRI...VFR/MVFR. SHOWERS POSSIBLE.
FRI NGT/SAT...RESTRICTIONS POSSIBLE FROM SHRA AS COLD FRONT
PASSES.
SAT NGT/SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT SHSN ESPECIALLY
CENTRAL NY TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...CMG
LONG TERM...MDP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1127 AM EST TUE NOV 19 2013
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS FLURRIES AND EVEN SOME PATCHY FREEZING
DRIZZLE WILL GRADUALLY COME TO AN END EARLY THIS AFTERNOON AS HIGH
PRESSURE SLOWLY BUILDS INTO THE REGION. BRISK NORTHWEST WINDS
COMBINED WITH ABUNDANT CLOUD COVER WILL KEEP TEMPERATURES MAINLY
IN THE MIDDLE TO UPPER 30S FOR DAYTIME HIGHS THIS AFTERNOON ACROSS
CENTRAL NEW YORK...WITH UPPER 30S TO LOWER 40S ACROSS NORTHEAST
PENNSYLVANIA. HIGH PRESSURE WILL THEN DOMINATE THE WEATHER PATTERN
...WITH DRY AND SLOWLY MODERATING TEMPERATURES EXPECTED THROUGH
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADARS STILL SHOW PERSISTENT LAKE EFFECT SNOW SHOWERS/FLURRIES AND
DRIZZLE OR EVEN FREEZING DRIZZLE DOWNWIND OF LAKE ONTARIO. THE
LOW-LEVEL FLOW WAS ABT FROM 310 DEGREES AND CONTS TO DIRECT LAKE
EFFECT MOISTURE INTO THE HILLS OF CENTRAL NY AND FAR NE PA AS OF
LATE THIS MORNING. MEANWHILE ALOFT THERE WAS STRG SYNOPTIC SCALE SUBSC
ASSCTD WITH THE PASSAGE OF THE UPPER LEVEL TROF AXIS TO THE EAST
INTO NEW ENGLAND.
MODEL SOUNDINGS BETWEEN THE NAM...GFS AND RAP DIVERGE AS TO HOW
THE BNDRY LAYER MOISTURE WILL EVOLVE THIS AFTERNOON INTO THE EVENING.
THE NAM RAPIDLY CLEARS OUT THE AREA THIS AFTERNOON WITH
SIGNIFICANT LL DRY AIR ADVECTION. THE RAP HOLDS ONTO THE MOISTURE
TRAPPED BELOW THE INVERSION INTO THE EVENING HOURS. THE GFS IS IN
BETWEEN. LOOKING AT THE VSBL SATELLITE IMAGERY I AM LEANING TWD
THE RAP AS THERE WAS SIGNIFICANT CLD CVR N OF LAKE ONTARIO IN ERN
ONT AND QUE. SFC DWPTS DO COME DOWN DURG THE AFTERNOON BUT THE
SATELLITE IMAGERY STILL SHOWS CLD CVR EVEN WITH THE DROP IN SFC
DWPTS UPSTREAM. THIS DRIER SFC AIR WILL ADVECT SOUTHWARD THIS
AFTERNOON AND SHUD SNUFF OUT THE LAKE EFFECT SNOW SHOWERS AND
DZ/FZDZ BY 19Z THE LATEST.
ISSUED AN SPS EARLIER FOR PATCHY FZDZ WHICH IS ASSCTD WITH THE
LAKE EFFECT MOISTURE. FZDZ WAS CONFIRMED BY SOME OF OUR FACEBOOK
FANS OVER THE HIGHER TERRAIN IN C NY. CLD TOPS OUTSIDE THE LAKE
EFFECT SNOW BANDS WERE TOO SHALLOW FOR GLACIATION AND HENCE WE ARE
SEEING SOME PATCHY DRIZZLE. HIGHER TERRAIN AREAS REMAIN AT OR
BELOW FREEZING WITH PATCHY FZDZ AT TIMES. WILL REISSUE SPS SHORTLY TO
HIGHLIGHT THE END OF THE FREEZING DRIZZLE AND PRECIP.
CLD CVR SHUD HANG ON DOWNWIND OF LAKE ONTARIO WELL INTO THE EVE AS
PER RAP SOUNDINGS. GIVEN THE NW FLOW AND TRAJECTORIES ACRS LAKE
ONTARIO AND PRESENT CLD CVR UPSTREAM FROM THE LAKES IN
CANADA...HARD TO SEE CLRG IN THE HILLS OF C NY OR FAR NE PA B4 6Z.
SO WILL HANG ONTO CLDS SIMILAR TO THE 925 MB RH FIELDS ON THE RAP.
EVENTUALLY LATER TONIGHT...THE FLOW TURNS MORE N-NERLY AND THIS
IS WHEN CLRG SHUD FINALLY TAKE PLACE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A VERY QUIET SHORT TERM PERIOD ANTICIPATED AS HIGH PRESSURE
REMAINS IN FIRM CONTROL. BY WEDNESDAY...SE FLOW WILL INCREASE AS
HIGH PRESSURE SLIDES TO OUR EAST. EXPECT A WARMER DAY THAN TODAY
WITH MOST PLACES EXPECTED TO WARM INTO THE LWR TO MIDDLE 40S FOR
HIGHS. SIMILAR CONDITIONS EXPECTED ON THURSDAY AS 850-HPA TEMPS
SLOWLY BEGIN WARMING IN DEVELOPING SOUTHWEST FLOW ALOFT. PRECIP TO
MAKE A POSSIBLE RETURN THU NGT/EARLY FRI AS WARM AIR ADVECTION
INTERACTS WITH A NORTHWARD LIFTING WARM FRONT LIFTING NORTH
THROUGH THE OHIO VLY. FOR NOW...HAVE CAPPED POPS IN THE SLGT CHC
CATEGORY AS BEST ISENTROPIC ASCENT IS EXPECTED WELL WEST OF OUR
REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LATEST GFS AND ECMWF MODEL RUNS SUGGEST AT LEAST A SHORT TERM PATTERN
CHANGE FOR THE UPCOMING WEEKEND AS A HIGH AMPLITUDE 500 MB TROF IS
FORECAST TO DIG ACROSS THE NORTHEASTERN CONUS. DIFFERENCES EXIST
IN TIMING AND STRENGTH OF THE FEATURES ALOFT AND AT THE SURFACE...BUT
SUFFICE IT TO SAY THE FRI-SAT TIME FRAME LOOKS TO HAVE A HIGH POTENTIAL
FOR INCLEMENT WEATHER. THE SFC LOW TRACK CURRENTLY SUGGESTS A PASSAGE
RIGHT OVER THE CWA WHICH COULD BRING SOME WINTRY PRECIP TO THE REGION...
ALTHOUGH THERMAL PROFILES ONLY SEEM TO SUGGEST A RAIN OR WET SNOW ENVIRONMENT
FROM FRI-SAT AS WET BULB TEMPS APPEAR TO BE WELL ABOVE ZERO IN THE BOUNDARY
LAYER. IN SOME RESPECTS...THE MOS GUIDANCE TEMPS MAY BE A BIT TOO
COLD AT NIGHT ON FRIDAY NIGHT...AND AGAIN SATURDAY NIGHT. AT THIS
TIME THERE REMAINS TOO MUCH UNCERTAINTY IN HOW MUCH PRE-PRECIPITATION
COOLING WOULD TAKE PLACE FRI EVENING...AND HOW MUCH CAA COOLING MIGHT
OCCUR BEFORE SUNRISE ON SUNDAY AFTER THE FROPA TO MAKE ANY SIGNIFICANT
DEVIATIONS FROM THE MOS NUMBERS...OR OUR PREVIOUS FORECAST. SIGNIFICANTLY
COLDER AIR DOES APPEAR TO BE DRAWN SOUTH AT SOME POINT DURING THE
LATTER HALF OF THE WEEKEND INTO NEXT WEEK WITH DAILY TEMPS AVERAGING
WELL BELOW NORMAL ALONG WITH GOOD PROBABILITIES FOR NORTHWESTERLY
ORIENTED LAKE EFFECT SNOWS.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
GNRL VFR CONDS WILL CONT THRU THE TAF PD. NW FLOW OF CAA WILL
PRODUCE CLDS AND SOME LGT LE SNOW AND RAIN SHWRS EARLY. SKIES WILL
CLR AFT 21Z AS DRIER AIR MVES. WINDS WILL CONT TO BE GUSTY THRU
THE DAYLIGHT HRS...THEN BECOME LGTR AFT 00Z THE HIPRES BLDS INTO
THE AREA.
OUTLOOK...
WED THROUGH THU...VFR.
FRI...VFR/MVFR. SHOWERS POSSIBLE.
SAT...MVFR. PERIODS OF RAIN POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...CMG
LONG TERM...JAB
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
948 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 947 PM CST WED NOV 20 2013
DID ISSUE A WIND CHILL ADVISORY FOR THE NORTHWEST TONIGHT INTO
THURSDAY MORNING WITH WIND CHILLS OF -25 TO -30 EXPECTED.
TEMPERATURES WILL QUICKLY FALL BELOW ZERO ACROSS THE NORTHWEST BY
05 UTC AS SKIES CLEAR WITH FRESH SNOW AS THE SURFACE HIGH
CONTINUES TO BUILD INTO WESTERN NORTH DAKOTA.
UPDATE ISSUED AT 645 PM CST WED NOV 20 2013
UPDATE TO CANCEL THE WINTER WEATHER ADVISORY FOR
WILLIAMS...DUNN...MOUNTRAIL...MCKENZIE AND RENVILLE COUNTIES.
HOWEVER...A WIND CHILL ADVISORY MAY BE NEEDED TONIGHT ACROSS THE
NORTHWEST. WIND CHILL VALUES MAY APPROACH -25 AS A QUICK DROP OFF
IN SURFACE TEMPERATURES TO NEAR -10 ARE EXPECTED WITH THE NEW SNOW
COVER AND CLEARING SKIES.
UPDATE ISSUED AT 447 PM CST WED NOV 20 2013
QUICK UPDATE TO EXPAND THE WINTER WEATHER ADVISORY INTO
RENVILLE...TOWNER...BOTTINEAU...PIERCE AND ROLETTE COUNTIES.
HEAVY BANDED SNOW IS EXPECTED TO RESULT IN 3 TO 5 INCHES OF SNOW
FOR THESE AREAS WITH VISIBILITIES NEAR ONE QUARTER OF A MILE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
LATEST RADAR AND WEATHER CAMERAS INDICATE SNOW FROM WEST CENTRAL
INTO NORTH CENTRAL NORTH DAKOTA. SNOW HAS BEEN HEAVY AT TIMES WITH
VISIBILITY DOWN TO A QUARTER. LATEST REPORTS AND ESTIMATES INDICATE
1-2 INCHES HAS FALLEN FROM WILLISTON TO DICKINSON. LIKELY SOME
HIGHER AMOUNTS IN A PERSISTENT BAND ACROSS MAINLY MCKENZIE COUNTY.
THIS BAND HAS BECOMING MORE ENHANCED ACROSS MOUNTRAIL INTO WARD
COUNTY IN THE PAST HOUR.
EXPECT ANOTHER 2 TO 4 HOURS OF LIGHT TO MODERATE SNOW IN THE
ADVISORY AREA...BEFORE SHIFTING FARTHER SOUTH AND EAST. 12 UTC
MODEL GUIDANCE AND THE LATEST MESOSCALE RAP AND HRRR SHOW
PRECIPITATION ENDING QUICKLY AROUND 00 UTC IN WESTERN NORTH DAKOTA
AS BEST FRONTOGENETICAL FORCING SHIFTS INTO CENTRAL NORTH DAKOTA.
THIS SHOULD PUT AN END TO ACCUMULATING SNOW OVER THE ADVISORY AREA
BY MID EVENING. CURRENT HAZARD GOES UNTIL 10 PM AND EVENING SHIFT
CAN CANCEL EARLY IF NEEDED.
BEST SNOW CHANCES ARE OVER CENTRAL NORTH DAKOTA THIS EVENING. AND
ACCUMULATIONS OF AROUND AN INCH ARE POSSIBLE OVER THE SOUTH
CENTRAL AND FAR SOUTHWEST...FROM BOWMAN AND HETTINGER TO BISMARCK
AND JAMESTOWN. LESSER AMOUNTS...UNDER AN INCH ARE EXPECTED FROM
SELFRIDGE TO LAMOURE AND OAKES. MODEL SOUNDINGS INDICATE WARM
TEMPERATURES ALOFT IN THE FAR SOUTH CENTRAL...THUS HAVE INCLUDED A
MENTION OF MIXED PRECIPITATION SOUTH OF BISMARCK TO THE SOUTHERN
JAMES RIVER VALLEY.
PRECIPITATION ENDS QUICKLY IN THE CENTRAL AS THE UPPER TROUGH
TRANSLATES INTO THE AREA LATE TONIGHT. THEN WE ARE LOOKING AT VERY
COLD TEMPERATURES AND WIND CHILLS LATE TONIGHT AND THURSDAY. WIND
CHILLS FROM 10 BELOW SOUTH TO 20 BELOW NORTHWEST CAN BE EXPECTED
EARLY THURSDAY MORNING.
THURSDAY IS EXPECTED TO BE DRY BUT COLD WITH HIGHS OF 10 TO 20 ABOVE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE COLDEST AIR OF THE
SEASON THUS FAR FOR FRIDAY NIGHT INTO SATURDAY MORNING.
THE 12 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A WEAK
CLIPPER SYSTEM PROPAGATING NEAR THE INTERNATIONAL BORDER THURSDAY
NIGHT INTO FRIDAY MORNING. THIS IS FOLLOWED BY A 1050 MB HIGH
BUILDING ACROSS NORTH DAKOTA THROUGH THE REMAINDER OF THE DAY ON
FRIDAY. WHEN COMBINED WITH THE SNOW COVER THAT WILL BE ACROSS THE
NORTH...THE COLDEST NIGHT OF THE SEASON THUS FAR IS EXPECTED WITH
LOWS NEAR -15 NORTH...WITH THE SINGLE DIGITS BELOW ZERO ACROSS THE
SOUTH. DID UNDERCUT ALL GUIDANCE BY AT LEAST FIVE DEGREES ACROSS
THE SNOWPACK FOR LOWS FRIDAY NIGHT. WIND CHILLS MAY APPROACH
ADVISORY CRITERIA OF -25 TO -30 EARLY SATURDAY MORNING ACROSS THE
NORTH. HIGHS WARM BACK INTO THE 30S ON SUNDAY IN THE WARM SECTOR
OF A SOUTHERN CANADA CLIPPER. HOWEVER...THIS WARM UP IS BRIEF AS
ANOTHER COOL CANADIAN AIRMASS PROPAGATES SOUTH EARLY NEXT WEEK
UNDER NORTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY)
ISSUED AT 947 PM CST WED NOV 20 2013
IFR CONDITIONS IN SNOW AT KBIS AND KJMS THIS EVENING...WITH IFR
STRATUS AT KMOT THROUGH 06 UTC. OTHERWISE....CONDITIONS WILL
BECOME VFR ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE
NIGHT AS SURFACE HIGH PRESSURE BUILDS IN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 9 AM CST THURSDAY FOR NDZ001-002-009-
010.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
927 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 927 PM CST WED NOV 20 2013
MAIN ADJUSTMENT WAS TO PUT OUT A QUICK WINTER WX ADVISORY FOR OUR
NORTHWESTERN CWA AND FAR NORTHERN VALLEY COUNTIES AS WE HAVE HAD
REPORTS OF NEARLY 5 INCHES AT STARKWEATHER AND AROUND 4 AT MADDOCK
AND SNOW CONTINUES. PUTTING THE ROEBBER METHOD SNOW RATIO
CALCULATIONS FOR BOTH THE GFS AND NAM PUTS OUR NORTHWESTERN CWA
INTO AN OVER 20 TO 1 RATIO...WHICH MAY EXPLAIN THE HIGHER AMOUNTS
THAN EXPECTED. THE SNOW BAND WILL CONTINUE TO SLOWLY TRANSITION
EASTWARD AS THE 700MB FRONTOGENESIS BAND MOVES FURTHER INTO THE
NORTHERN RED RIVER VALLEY. THE STRENGTH OF THE FRONTOGENESIS BAND
IS EXPECTED TO DIMINISH AS IT MOVES EAST SO THINK THAT THE AMOUNTS
FROM GFK AND FURTHER SOUTH AND EAST WILL BE LIGHTER THAT THOSE IN
THE DVL AREA. CUT POPS IN THE SOUTH AS NOT MUCH HAS BEEN REACHING
THE GROUND OVER SOUTH CENTRAL ND AND MODELS HAVE BEEN TRENDING
LIGHTER WITH ANY SNOW IN THE SOUTHERN VALLEY. ALSO SLOWED THE
MOVEMENT OF SNOW INTO NORTHWESTERN MN. COOLED TEMPS DOWN A BIT
MORE IN THE NORTHWESTERN COUNTIES AS SINGLE DIGITS JUST TO OUR
NORTH AND WEST EVEN WITH CLOUD COVER CONTINUES TO FILTER INTO THE
AREA.
UPDATE ISSUED AT 642 PM CST WED NOV 20 2013
ADJUSTED POPS FOR GOING RADAR TRENDS. CURRENT SNOW BAND OVER THE
DVL AREA WILL MOVE SOUTHEASTWARD TONIGHT...WITH MODELS SHOWING
SOME WEAKENING. THE WRF AND ONE HRRR RUN SHOW VERY LITTLE SNOW
MAKING IT TO OUR SOUTHERN COUNTIES. THE 18Z NAM AND LATEST HRRR
RUN HOWEVER HAVE A NARROW BAND MOVING THROUGH LATE THIS EVENING.
CUT POPS IN THE SOUTH A BIT...BUT DID NOT REMOVE THEM COMPLETELY.
STILL THINK THAT THE 1 TO 3 INCHES NORTH OF HIGHWAY 200 WITH
HIGHEST AMOUNTS NEAR DVL SEEMS REASONABLE...SO WILL MAINTAIN SNOW
AMOUNTS. TEMPS HAVE BEEN FALLING IN THE NORTHWEST A BIT FASTER
THAN EXPECTED...AND THAT AREA HAS THE BEST CHANCE OF SEEING SOME
CLEARING TOWARDS MORNING. THUS...CUT LOWS A FEW DEGREES DOWN
FURTHER INTO THE SINGLE DIGITS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 339 PM CST WED NOV 20 2013
THE MAIN FORECAST CHALLENGES THIS AFTERNOON INCLUDE LIGHT SNOW
EVENT LATE TODAY AND TONIGHT...AND TEMPS THE NEXT SEVERAL DAYS.
THE COLD FRONT HAS PROGRESSED LITTLE OVER THE PAST FEW
HOURS...ALLOWING TEMPS INTO WC MN TO WARM NICELY...WITH KOTT SITTING
AT 49 DEGREES AS OF 21Z. AS AN UPPER SHORTWAVE TROUGH CONTINUES TO
PROPAGATE EASTWARD ACROSS SOUTHERN CANADA AND THE STRONGER COLD
SURGE ACCELERATES SOUTHEASTWARD...COLDER AIR WILL FILTER INTO THE
SOUTHEAST COUNTIES OVERNIGHT.
THE INITIAL BAND OF LIGHT SNOW THAT MOVED FROM PARTS OF THE DEVILS
LAKE BASIN INTO THE NORTHERN VALLEY HAS NOT BEEN HANDLED VERY WELL
BY THE MODELS...BUT HAS PUT DOWN SOME LIGHT SNOW ACCUMULATIONS FROM
THE DEVILS LAKE AREA EAST NORTHEASTWARD.
ATTENTION REMAINS FOCUSED ON AN AREA OF SNOW ACROSS NW AND NC ND
FORCED BY MID-LEVEL FRONTOGENESIS. SEVERAL RECENT OBS ACROSS NW ND
HAVE INDICATED +SN. 12Z RUNS OF THE NAM/ECMWF/GFS ALL BRING THE
BRUNT OF THIS BAND ACROSS THE DEVILS LAKE BASIN INTO THE NORTHERN
VALLEY...AND THIS MATCHES WELL WITH OBSERVED TRENDS. THUS AT THIS
POINT...IT STILL APPEARS THAT 1 TO 3 INCHES OF ACCUMULATION IS ON
TRACK FOR THESE AREAS....ALTHOUGH A FEW ISOLATED HIGHER AMOUNTS
CANNOT BE RULED OUT. MODELS DO SHOW A WEAKENING TREND OF THE
FRONTOGENETICAL BAND OVERNIGHT...SO CURRENT THINKING IS THAT
TOTALS WILL REMAIN MOSTLY BELOW ADVISORY THRESHOLDS.
HOWEVER...THE EXACT LOCATION OF THE BAND AND ITS INTENSITY WILL
NEED TO BE MONITORED OVERNIGHT. FARTHER SOUTHEAST...GENERALLY ONLY
VERY LIGHT ACCUMULATIONS ARE EXPECTED. WINDS WILL REMAIN IN THE 15
TO 20 MPH RANGE OVERNIGHT...WITH SOME HIGHER GUSTS. HAVE NOT
MENTIONED ANY BLOWING SNOW...BUT THIS WILL BE SOMETHING TO WATCH
AS WELL.
AS HIGH PRESSURE AREA BUILDS INTO WESTERN ND BY LATE
TONIGHT...THE COLUMN BEGINS TO DRY OUT...SO SOME CLEARING IS
POSSIBLE LATE TONIGHT OVER THE DEVILS LAKE REGION. THIS MAY AFFECT
HOW LOW TEMPS FALL IN THIS AREA. OTHERWISE...CLOUDS WILL PERSIST
OVER MOST OF THE AREA TONIGHT. DESPITE PERSISTENT LOW-LEVEL COLD
ADVECTION...TEMPS SHOULD STAY MAINLY IN THE TEENS ACROSS THE
SOUTHEAST HALF OF THE AREA OVERNIGHT. .
FOR THURSDAY...THERE COULD BE A BIT OF LINGERING LIGHT SNOW EAST OF
THE VALLEY...WITH SFC HIGH PRESSURE AND CONTINUED COLD ADVECTION
LIMITING THE TEMP RISE...EVEN WITH SOME SUNSHINE...ESPECIALLY ACROSS
THE NORTH. TOMORROW NIGHT...WARM ADVECTION DEVELOPS AHEAD OF AN
UPPER SHORTWAVE TROUGH DIVING SOUTHEASTWARD FROM CANADA ON THE
PERIPHERY OF AN AMPLIFYING RIDGE ACROSS THE WESTERN CONUS. A MAJOR
QUESTION WILL BE HOW FAR TEMPS CAN FALL WITH DEVELOPING WARM
ADVECTION GIVEN SOME NEW SNOW ON THE GROUND IN PLACES. AT THIS
POINT KEPT LOWS MAINLY IN THE SINGLE DIGITS TO LOW TEENS. THE 12Z
GFS/ECMWF/NAM ALL KEEP ANY PRECIP FROM SYSTEM TO THE SOUTH OUT OF
THE AREA. AS A RESULT...MOST AREAS SHOULD REMAIN DRY THURSDAY
NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 PM CST WED NOV 20 2013
THE NEXT WAVE DROPS ACROSS THE REGION ON FRIDAY...WITH A REINFORCING
COLD FRONT MOVING SOUTHWARD DURING THE DAY. SOME LIGHT SNOW MAY
ACCOMPANY THE SYSTEM WITH SOME Q-VECTOR CONVERGENCE IN THE
700-300MB LAYER AND A 300 MB JET STREAK NOSING INTO THE DAKOTAS.
A STRONG 1049 MB ARCTIC HIGH WILL BUILD SOUTHWARD FRIDAY NIGHT INTO
SATURDAY...CENTERED OVER CENTRAL OR WESTERN ND SATURDAY MORNING.
BEHIND THE FRONT...925 MB TEMPS WILL FALL TO AROUND -16 TO
-20C...HIGHEST TO THE NORTH. TEMPS FRIDAY NIGHT SHOULD BE DOWN INTO
AT LEAST THE SINGLE DIGITS...WITH THE BEST LIKELIHOOD FOR SUBZERO
READINGS ACROSS NORTHWESTERN AREAS...WHERE SOME SNOWCOVER MAY EXIST
AND WINDS WILL BE LIGHTEST. TEMPS ON SATURDAY WILL LIKELY REMAIN
WELL BELOW NORMAL IN THE SINGLE DIGITS AND TEENS...WITH WEAK MIXING
UNDER THE SFC HIGH.
500 MB PATTERN BECOMES A BIT MORE WEST-NORTHWEST AS TROUGH AND COLD
AIRMASS MOVE EAST SUNDAY AND MONDAY. THUS LOOK FOR TEMPS TO
MODERATE QUICKLY SUN-MON BACK TO NEAR NORMAL VALUES. A FAST MOVING
SFC LOW WILL MOVE THRU CNTRL MANITOBA INTO WRN ONTARIO TO LAKE
SUPERIOR SUNDAY-MON...SPREADING SOME LOW CHANCES FOR LIGHT SNOW INTO
LAKE OF THE WOODS REGION. A SHOT OF COLDER AIR FOLLOWS THIS SFC LOW
FOR MID WEEK AS HIGH PRESSURE DROPS SOUTH. OUTSIDE OF SOME LOW
CHANCES FOR LIGHT SNOW IN LAKE OF THE WOODS AREA...DRY FCST FOR
SUNDAY INTO NEXT WEDENSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 642 PM CST WED NOV 20 2013
MVFR CIGS WILL CONTINUE ACROSS MOST OF THE REGION TONIGHT. THE
BAND OF SNOW WILL MOVE IN FROM NORTHWEST TO SOUTHEAST AND DROP VIS
AT TIMES TO 1-3SM WITH KDVL GOING DOWN BELOW 1SM AT TIMES THIS
EVENING. THE SNOW WILL MOVE OUT OF THE REGION DURING THE EARLY
MORNING HOURS...ALTHOUGH THE MVFR CIGS MAY HANG AROUND A BIT
LONGER. CIGS SHOULD RETURN TO VFR CONDITIONS BY LATER IN THE
MORNING WITH ONLY CIRRUS EXPECTED BY THE END OF THE PERIOD.
NORTH WINDS WILL BE RATHER GUSTY OVERNIGHT TO ABOVE 20 KTS AT
TIMES...BUT SHOULD DIMINISH TOWARDS THE END OF THE TAF PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR NDZ006>008-
014>016-024-026-054.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ004.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
645 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 645 PM CST WED NOV 20 2013
UPDATE TO CANCEL THE WINTER WEATHER ADVISORY FOR
WILLIAMS...DUNN...MOUNTRAIL...MCKENZIE AND RENVILLE COUNTIES.
HOWEVER...A WIND CHILL ADVISORY MAY BE NEEDED TONIGHT ACROSS THE
NORTHWEST. WIND CHILL VALUES MAY APPROACH -25 AS A QUICK DROP OFF
IN SURFACE TEMPERATURES TO NEAR -10 ARE EXPECTED WITH THE NEW SNOW
COVER AND CLEARING SKIES.
UPDATE ISSUED AT 447 PM CST WED NOV 20 2013
QUICK UPDATE TO EXPAND THE WINTER WEATHER ADVISORY INTO
RENVILLE...TOWNER...BOTTINEAU...PIERCE AND ROLETTE COUNTIES.
HEAVY BANDED SNOW IS EXPECTED TO RESULT IN 3 TO 5 INCHES OF SNOW
FOR THESE AREAS WITH VISIBILITIES NEAR ONE QUARTER OF A MILE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
LATEST RADAR AND WEATHER CAMERAS INDICATE SNOW FROM WEST CENTRAL
INTO NORTH CENTRAL NORTH DAKOTA. SNOW HAS BEEN HEAVY AT TIMES WITH
VISIBILITY DOWN TO A QUARTER. LATEST REPORTS AND ESTIMATES INDICATE
1-2 INCHES HAS FALLEN FROM WILLISTON TO DICKINSON. LIKELY SOME
HIGHER AMOUNTS IN A PERSISTENT BAND ACROSS MAINLY MCKENZIE COUNTY.
THIS BAND HAS BECOMING MORE ENHANCED ACROSS MOUNTRAIL INTO WARD
COUNTY IN THE PAST HOUR.
EXPECT ANOTHER 2 TO 4 HOURS OF LIGHT TO MODERATE SNOW IN THE
ADVISORY AREA...BEFORE SHIFTING FARTHER SOUTH AND EAST. 12 UTC
MODEL GUIDANCE AND THE LATEST MESOSCALE RAP AND HRRR SHOW
PRECIPITATION ENDING QUICKLY AROUND 00 UTC IN WESTERN NORTH DAKOTA
AS BEST FRONTOGENETICAL FORCING SHIFTS INTO CENTRAL NORTH DAKOTA.
THIS SHOULD PUT AN END TO ACCUMULATING SNOW OVER THE ADVISORY AREA
BY MID EVENING. CURRENT HAZARD GOES UNTIL 10 PM AND EVENING SHIFT
CAN CANCEL EARLY IF NEEDED.
BEST SNOW CHANCES ARE OVER CENTRAL NORTH DAKOTA THIS EVENING. AND
ACCUMULATIONS OF AROUND AN INCH ARE POSSIBLE OVER THE SOUTH
CENTRAL AND FAR SOUTHWEST...FROM BOWMAN AND HETTINGER TO BISMARCK
AND JAMESTOWN. LESSER AMOUNTS...UNDER AN INCH ARE EXPECTED FROM
SELFRIDGE TO LAMOURE AND OAKES. MODEL SOUNDINGS INDICATE WARM
TEMPERATURES ALOFT IN THE FAR SOUTH CENTRAL...THUS HAVE INCLUDED A
MENTION OF MIXED PRECIPITATION SOUTH OF BISMARCK TO THE SOUTHERN
JAMES RIVER VALLEY.
PRECIPITATION ENDS QUICKLY IN THE CENTRAL AS THE UPPER TROUGH
TRANSLATES INTO THE AREA LATE TONIGHT. THEN WE ARE LOOKING AT VERY
COLD TEMPERATURES AND WIND CHILLS LATE TONIGHT AND THURSDAY. WIND
CHILLS FROM 10 BELOW SOUTH TO 20 BELOW NORTHWEST CAN BE EXPECTED
EARLY THURSDAY MORNING.
THURSDAY IS EXPECTED TO BE DRY BUT COLD WITH HIGHS OF 10 TO 20 ABOVE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE COLDEST AIR OF THE
SEASON THUS FAR FOR FRIDAY NIGHT INTO SATURDAY MORNING.
THE 12 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A WEAK
CLIPPER SYSTEM PROPAGATING NEAR THE INTERNATIONAL BORDER THURSDAY
NIGHT INTO FRIDAY MORNING. THIS IS FOLLOWED BY A 1050 MB HIGH
BUILDING ACROSS NORTH DAKOTA THROUGH THE REMAINDER OF THE DAY ON
FRIDAY. WHEN COMBINED WITH THE SNOW COVER THAT WILL BE ACROSS THE
NORTH...THE COLDEST NIGHT OF THE SEASON THUS FAR IS EXPECTED WITH
LOWS NEAR -15 NORTH...WITH THE SINGLE DIGITS BELOW ZERO ACROSS THE
SOUTH. DID UNDERCUT ALL GUIDANCE BY AT LEAST FIVE DEGREES ACROSS
THE SNOWPACK FOR LOWS FRIDAY NIGHT. WIND CHILLS MAY APPROACH
ADVISORY CRITERIA OF -25 TO -30 EARLY SATURDAY MORNING ACROSS THE
NORTH. HIGHS WARM BACK INTO THE 30S ON SUNDAY IN THE WARM SECTOR
OF A SOUTHERN CANADA CLIPPER. HOWEVER...THIS WARM UP IS BRIEF AS
ANOTHER COOL CANADIAN AIRMASS PROPAGATES SOUTH EARLY NEXT WEEK
UNDER NORTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 645 PM CST WED NOV 20 2013
IFR CONDITIONS IN SNOW ARE EXPECTED AT KDIK/KBIS/KMOT/KJMS THIS
EVENING...WITH CONDITIONS IMPROVING FROM WEST TO EAST OVERNIGHT.
VFR CONDITIONS ARE EXPECTED AT KISN THROUGHOUT THE 00 UTC TAF
CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 PM CST THIS EVENING FOR NDZ004-
005-011>013-021.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
642 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 642 PM CST WED NOV 20 2013
ADJUSTED POPS FOR GOING RADAR TRENDS. CURRENT SNOW BAND OVER THE
DVL AREA WILL MOVE SOUTHEASTWARD TONIGHT...WITH MODELS SHOWING
SOME WEAKENING. THE WRF AND ONE HRRR RUN SHOW VERY LITTLE SNOW
MAKING IT TO OUR SOUTHERN COUNTIES. THE 18Z NAM AND LATEST HRRR
RUN HOWEVER HAVE A NARROW BAND MOVING THROUGH LATE THIS EVENING.
CUT POPS IN THE SOUTH A BIT...BUT DID NOT REMOVE THEM COMPLETELY.
STILL THINK THAT THE 1 TO 3 INCHES NORTH OF HIGHWAY 200 WITH
HIGHEST AMOUNTS NEAR DVL SEEMS REASONABLE...SO WILL MAINTAIN SNOW
AMOUNTS. TEMPS HAVE BEEN FALLING IN THE NORTHWEST A BIT FASTER
THAN EXPECTED...AND THAT AREA HAS THE BEST CHANCE OF SEEING SOME
CLEARING TOWARDS MORNING. THUS...CUT LOWS A FEW DEGREES DOWN
FURTHER INTO THE SINGLE DIGITS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 339 PM CST WED NOV 20 2013
THE MAIN FORECAST CHALLENGES THIS AFTERNOON INCLUDE LIGHT SNOW
EVENT LATE TODAY AND TONIGHT...AND TEMPS THE NEXT SEVERAL DAYS.
THE COLD FRONT HAS PROGRESSED LITTLE OVER THE PAST FEW
HOURS...ALLOWING TEMPS INTO WC MN TO WARM NICELY...WITH KOTT SITTING
AT 49 DEGREES AS OF 21Z. AS AN UPPER SHORTWAVE TROUGH CONTINUES TO
PROPAGATE EASTWARD ACROSS SOUTHERN CANADA AND THE STRONGER COLD
SURGE ACCELERATES SOUTHEASTWARD...COLDER AIR WILL FILTER INTO THE
SOUTHEAST COUNTIES OVERNIGHT.
THE INITIAL BAND OF LIGHT SNOW THAT MOVED FROM PARTS OF THE DEVILS
LAKE BASIN INTO THE NORTHERN VALLEY HAS NOT BEEN HANDLED VERY WELL
BY THE MODELS...BUT HAS PUT DOWN SOME LIGHT SNOW ACCUMULATIONS FROM
THE DEVILS LAKE AREA EAST NORTHEASTWARD.
ATTENTION REMAINS FOCUSED ON AN AREA OF SNOW ACROSS NW AND NC ND
FORCED BY MID-LEVEL FRONTOGENESIS. SEVERAL RECENT OBS ACROSS NW ND
HAVE INDICATED +SN. 12Z RUNS OF THE NAM/ECMWF/GFS ALL BRING THE
BRUNT OF THIS BAND ACROSS THE DEVILS LAKE BASIN INTO THE NORTHERN
VALLEY...AND THIS MATCHES WELL WITH OBSERVED TRENDS. THUS AT THIS
POINT...IT STILL APPEARS THAT 1 TO 3 INCHES OF ACCUMULATION IS ON
TRACK FOR THESE AREAS....ALTHOUGH A FEW ISOLATED HIGHER AMOUNTS
CANNOT BE RULED OUT. MODELS DO SHOW A WEAKENING TREND OF THE
FRONTOGENETICAL BAND OVERNIGHT...SO CURRENT THINKING IS THAT
TOTALS WILL REMAIN MOSTLY BELOW ADVISORY THRESHOLDS.
HOWEVER...THE EXACT LOCATION OF THE BAND AND ITS INTENSITY WILL
NEED TO BE MONITORED OVERNIGHT. FARTHER SOUTHEAST...GENERALLY ONLY
VERY LIGHT ACCUMULATIONS ARE EXPECTED. WINDS WILL REMAIN IN THE 15
TO 20 MPH RANGE OVERNIGHT...WITH SOME HIGHER GUSTS. HAVE NOT
MENTIONED ANY BLOWING SNOW...BUT THIS WILL BE SOMETHING TO WATCH
AS WELL.
AS HIGH PRESSURE AREA BUILDS INTO WESTERN ND BY LATE
TONIGHT...THE COLUMN BEGINS TO DRY OUT...SO SOME CLEARING IS
POSSIBLE LATE TONIGHT OVER THE DEVILS LAKE REGION. THIS MAY AFFECT
HOW LOW TEMPS FALL IN THIS AREA. OTHERWISE...CLOUDS WILL PERSIST
OVER MOST OF THE AREA TONIGHT. DESPITE PERSISTENT LOW-LEVEL COLD
ADVECTION...TEMPS SHOULD STAY MAINLY IN THE TEENS ACROSS THE
SOUTHEAST HALF OF THE AREA OVERNIGHT. .
FOR THURSDAY...THERE COULD BE A BIT OF LINGERING LIGHT SNOW EAST OF
THE VALLEY...WITH SFC HIGH PRESSURE AND CONTINUED COLD ADVECTION
LIMITING THE TEMP RISE...EVEN WITH SOME SUNSHINE...ESPECIALLY ACROSS
THE NORTH. TOMORROW NIGHT...WARM ADVECTION DEVELOPS AHEAD OF AN
UPPER SHORTWAVE TROUGH DIVING SOUTHEASTWARD FROM CANADA ON THE
PERIPHERY OF AN AMPLIFYING RIDGE ACROSS THE WESTERN CONUS. A MAJOR
QUESTION WILL BE HOW FAR TEMPS CAN FALL WITH DEVELOPING WARM
ADVECTION GIVEN SOME NEW SNOW ON THE GROUND IN PLACES. AT THIS
POINT KEPT LOWS MAINLY IN THE SINGLE DIGITS TO LOW TEENS. THE 12Z
GFS/ECMWF/NAM ALL KEEP ANY PRECIP FROM SYSTEM TO THE SOUTH OUT OF
THE AREA. AS A RESULT...MOST AREAS SHOULD REMAIN DRY THURSDAY
NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 PM CST WED NOV 20 2013
THE NEXT WAVE DROPS ACROSS THE REGION ON FRIDAY...WITH A REINFORCING
COLD FRONT MOVING SOUTHWARD DURING THE DAY. SOME LIGHT SNOW MAY
ACCOMPANY THE SYSTEM WITH SOME Q-VECTOR CONVERGENCE IN THE
700-300MB LAYER AND A 300 MB JET STREAK NOSING INTO THE DAKOTAS.
A STRONG 1049 MB ARCTIC HIGH WILL BUILD SOUTHWARD FRIDAY NIGHT INTO
SATURDAY...CENTERED OVER CENTRAL OR WESTERN ND SATURDAY MORNING.
BEHIND THE FRONT...925 MB TEMPS WILL FALL TO AROUND -16 TO
-20C...HIGHEST TO THE NORTH. TEMPS FRIDAY NIGHT SHOULD BE DOWN INTO
AT LEAST THE SINGLE DIGITS...WITH THE BEST LIKELIHOOD FOR SUBZERO
READINGS ACROSS NORTHWESTERN AREAS...WHERE SOME SNOWCOVER MAY EXIST
AND WINDS WILL BE LIGHTEST. TEMPS ON SATURDAY WILL LIKELY REMAIN
WELL BELOW NORMAL IN THE SINGLE DIGITS AND TEENS...WITH WEAK MIXING
UNDER THE SFC HIGH.
500 MB PATTERN BECOMES A BIT MORE WEST-NORTHWEST AS TROUGH AND COLD
AIRMASS MOVE EAST SUNDAY AND MONDAY. THUS LOOK FOR TEMPS TO
MODERATE QUICKLY SUN-MON BACK TO NEAR NORMAL VALUES. A FAST MOVING
SFC LOW WILL MOVE THRU CNTRL MANITOBA INTO WRN ONTARIO TO LAKE
SUPERIOR SUNDAY-MON...SPREADING SOME LOW CHANCES FOR LIGHT SNOW INTO
LAKE OF THE WOODS REGION. A SHOT OF COLDER AIR FOLLOWS THIS SFC LOW
FOR MID WEEK AS HIGH PRESSURE DROPS SOUTH. OUTSIDE OF SOME LOW
CHANCES FOR LIGHT SNOW IN LAKE OF THE WOODS AREA...DRY FCST FOR
SUNDAY INTO NEXT WEDENSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 642 PM CST WED NOV 20 2013
MVFR CIGS WILL CONTINUE ACROSS MOST OF THE REGION TONIGHT. THE
BAND OF SNOW WILL MOVE IN FROM NORTHWEST TO SOUTHEAST AND DROP VIS
AT TIMES TO 1-3SM WITH KDVL GOING DOWN BELOW 1SM AT TIMES THIS
EVENING. THE SNOW WILL MOVE OUT OF THE REGION DURING THE EARLY
MORNING HOURS...ALTHOUGH THE MVFR CIGS MAY HANG AROUND A BIT
LONGER. CIGS SHOULD RETURN TO VFR CONDITIONS BY LATER IN THE
MORNING WITH ONLY CIRRUS EXPECTED BY THE END OF THE PERIOD.
NORTH WINDS WILL BE RATHER GUSTY OVERNIGHT TO ABOVE 20 KTS AT
TIMES...BUT SHOULD DIMINISH TOWARDS THE END OF THE TAF PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
945 AM EST TUE NOV 19 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON
WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY
INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY
ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CLEARING TREND CAN BE SEEN UPSTREAM ACROSS MICHIGAN AND HAVE
TRIED TO TIME THIS INTO OHIO THROUGH MID-DAY. CLOUDS MAY
EXPERIENCE SOME DIURNAL ENHANCEMENT TOWARDS LATE MORNING...WITH
THE DECREASING TREND RESUMING DURING THE AFTERNOON. NO SIGNIFICANT
DEVIATION FROM THIS WITH THE MID MORNING UPDATE.
PREVIOUS DISCUUSION...HIGH PRESSURE WILL CONTINUE TO BUILD IN
FROM THE WEST TODAY WHILE A TROUGH LINGERS OVER QUEBEC. WE HAD
LITTLE IN THE WAY OF LAKE EFFECT SNOW OVERNIGHT WITH RIDGING OVER
ALL BUT ABOUT THE EASTERN THIRD OF LAKE ERIE. SOME LIGHT SNOW
SHOWERS THAT WERE FOCUSED TOWARDS NEW YORK MAY SHIFT WESTWARD INTO
MAINLY NW PA AS WINDS THROUGH 850MB BECOME MORE NORTHERLY THIS
MORNING. AFTER THAT TIME THE MOISTURE DEPTH DECREASES WITH
STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME TO AN END. NO
ACCUMULATION EXPECTED.
MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE
REGION. INVERSION HEIGHTS LOWER TODAY AS THE HIGH BUILDS OVERHEAD
AND THE RUC SEEMS TO BE DOING THE BEST WITH WITH HIGH 925MB
MOISTURE THROUGH THE DAY. WILL FAVOR A MORE PESSIMISTIC CLOUD
FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT THIS EVENING. HIGHS
WILL ONLY RECOVER A FEW DEGREES WITH COOL NORTHERLY FLOW WITH
HIGHS IN THE UPPER 30S/LOW 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE
INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE
SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE
AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF
SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S.
UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD
TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH
NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE
WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS
SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND
SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE
ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH
THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT
THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA
IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS
CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER
LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE
MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER
CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE
SLOWER AND LESS ROBUST WITH PRECIPITATION.
PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON
THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM
TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND
WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE
TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY
STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY
ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY
PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY
12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE
EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM
LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP
FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN.
SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND
THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT
THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR
SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH
READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD
WARMER ON MONDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
STRATO CU CIGS CONTINUE TO BLANKET THE AREA THIS MORNING.
STARTING TO SEE THE CLOUDS BREAK UP OVER LOWER MICHIGAN AND EXPECT
CLEARING TO BEGIN ACROS THE AREA LATER THIS MORNING. IT WILL
LIKELY TAKE TILL LATE IN THE DAY BEFORE KERI AND KYNG LOSE THEIR
CIGS. FOR THE MOST PART CIGS SHOULD BE VFR THIS MORNING BUT A
COUPLE OF POCKETS OF MVFR REMAIN. THESE SHOULD LIFT SHORTLY. NW
FLOW WILL BECOME N THIS AFTERNOON AND THEN LIGHT AND VARIABLE
OVERNIGHT. THE SECOND HALF OF THE TAF PERIOD SHOULD BE MAINLY
CLEAR.
OUTLOOK...NON VFR POSSIBLE THURSDAY.
&&
.MARINE...
STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP
THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH
QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL
BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE
TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE
WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER
ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL
DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN
THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME
NORTHWEST ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148-
149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/OUDEMAN
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
652 AM EST TUE NOV 19 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON
WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY
INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY
ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CLEARING TREND CAN BE SEEN UPSTREAM ACROSS MICHIGAN AND HAVE
TRIED TO TIME THIS INTO OHIO THROUGH MID-DAY. CLOUDS MAY
EXPERIENCE SOME DIURNAL ENHANCEMENT TOWARDS LATE MORNING...WITH
THE DECREASING TREND RESUMING DURING THE AFTERNOON.
PREVIOUS DISCUUSION...HIGH PRESSURE WILL CONTINUE TO BUILD IN
FROM THE WEST TODAY WHILE A TROUGH LINGERS OVER QUEBEC. WE HAD
LITTLE IN THE WAY OF LAKE EFFECT SNOW OVERNIGHT WITH RIDGING OVER
ALL BUT ABOUT THE EASTERN THIRD OF LAKE ERIE. SOME LIGHT SNOW
SHOWERS THAT WERE FOCUSED TOWARDS NEW YORK MAY SHIFT WESTWARD INTO
MAINLY NW PA AS WINDS THROUGH 850MB BECOME MORE NORTHERLY THIS
MORNING. AFTER THAT TIME THE MOISTURE DEPTH DECREASES WITH
STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME TO AN END. NO
ACCUMULATION EXPECTED.
MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE
REGION. INVERSION HEIGHTS LOWER TODAY AS THE HIGH BUILDS OVERHEAD
AND THE RUC SEEMS TO BE DOING THE BEST WITH WITH HIGH 925MB
MOISTURE THROUGH THE DAY. WILL FAVOR A MORE PESSIMISTIC CLOUD
FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT THIS EVENING. HIGHS
WILL ONLY RECOVER A FEW DEGREES WITH COOL NORTHERLY FLOW WITH
HIGHS IN THE UPPER 30S/LOW 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE
INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE
SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE
AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF
SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S.
UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD
TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH
NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE
WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS
SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND
SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE
ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH
THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT
THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA
IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS
CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER
LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE
MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER
CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE
SLOWER AND LESS ROBUST WITH PRECIPITATION.
PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON
THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM
TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND
WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE
TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY
STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY
ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY
PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY
12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE
EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM
LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP
FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN.
SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND
THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT
THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR
SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH
READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD
WARMER ON MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
STRATO CU CIGS CONTINUE TO BLANKET THE AREA THIS MORNING.
STARTING TO SEE THE CLOUDS BREAK UP OVER LOWER MICHIGAN AND EXPECT
CLEARING TO BEGIN ACROS THE AREA LATER THIS MORNING. IT WILL
LIKELY TAKE TILL LATE IN THE DAY BEFORE KERI AND KYNG LOSE THEIR
CIGS. FOR THE MOST PART CIGS SHOULD BE VFR THIS MORNING BUT A
COUPLE OF POCKETS OF MVFR REMAIN. THESE SHOULD LIFT SHORTLY. NW
FLOW WILL BECOME N THIS AFTERNOON AND THEN LIGHT AND VARIABLE
OVERNIGHT. THE SECOND HALF OF THE TAF PERIOD SHOULD BE MAINLY
CLEAR.
OUTLOOK...NON VFR POSSIBLE THURSDAY.
&&
.MARINE...
STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP
THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH
QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL
BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE
TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE
WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER
ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL
DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN
THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME
NORTHWEST ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148-
149.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR
LEZ144>147.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
408 AM EST TUE NOV 19 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON
WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY
INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY
ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST TODAY WHILE A
TROUGH LINGERS OVER QUEBEC. WE HAD LITTLE IN THE WAY OF LAKE EFFECT
SNOW OVERNIGHT WITH RIDGING OVER ALL BUT ABOUT THE EASTERN THIRD OF
LAKE ERIE. SOME LIGHT SNOW SHOWERS THAT WERE FOCUSED TOWARDS NEW
YORK MAY SHIFT WESTWARD INTO MAINLY NW PA AS WINDS THROUGH 850MB
BECOME MORE NORTHERLY THIS MORNING. AFTER THAT TIME THE MOISTURE
DEPTH DECREASES WITH STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME
TO AN END. NO ACCUMULATION EXPECTED.
MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE REGION
WITH SKIES CLEARING BY LATE MORNING. INVERSION HEIGHTS LOWER TODAY
AS THE HIGH BUILDS OVERHEAD AND THE RUC SEEMS TO BE DOING THE BEST
WITH WITH HIGH 925MB MOISTURE THROUGH THE DAY. WILL FAVOR A MORE
PESSIMISTIC CLOUD FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT
THIS EVENING. HIGHS WILL ONLY RECOVER A FEW DEGREES WITH COOL
NORTHERLY FLOW WITH HIGHS IN THE UPPER 30S/LOW 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE
INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE
SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE
AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF
SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S.
UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD
TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH
NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE
WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS
SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND
SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE
ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH
THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT
THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA
IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS
CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER
LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE
MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER
CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE
SLOWER AND LESS ROBUST WITH PRECIPITATION.
PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON
THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM
TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND
WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE
TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY
STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY
ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY
PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY
12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE
EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM
LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP
FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN.
SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND
THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT
THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR
SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH
READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD
WARMER ON MONDAY.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
DEEP LOW PRESSURE IN WESTERN QUEBEC WILL CONTINUE NORTHEAST
OVERNIGHT AS HIGH PRESSURE BUILDS IN FROM THE WEST. LOW LEVEL WRAP
AROUND MOISTURE IS CURRENTLY ACROSS NRN OHIO AND NWRN PA TRAPPED
UNDER AN INVERSION. MOST CIGS VFR HOWEVER THERE ARE PATCHES OF
MVFR MIXED IN. DO EXPECT PERIODS OF MVFR TO CONTINUE ESPECIALLY
KERI WHERE COLD ADVECTION WILL INCREASINGLY TAP LAKE MOISTURE.
ALSO A DECENT CHANCE OF AN MVFR CIG AT KMFD IN UPSLOPE FLOW AND
ALSO KTOL...ADVECTING IN FROM SRN LWR MI. OTHERWISE EXPECT A LOW
VFR CIGS TO CONTINUE ACROSS THE REGION THROUGH THE NIGHT. DID KEEP
MVFR CONDITIONS AT KERI MOST OF THE NIGHT WITH A FEW LIGHT RAIN
AND SNOW SHOWERS POSSIBLE WITH THE INCREASING LAKE INFLUENCE.
TREND TO VFR FOR THE AREA TUESDAY WITH BUILDING HIGH PRESSURE
HOWEVER THERE IS A POTENTIAL THAT THE STRATUS WILL HANG ON
INTO/THRU THE MORNING HOURS...REMAINING TRAPPED UNDER THE
INVERSION.
OUTLOOK...NON VFR POSSIBLE THURSDAY.
&&
.MARINE...
STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP
THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH
QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL
BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE
TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE
WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER
ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL
DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN
THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME
NORTHWEST ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148-
149.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR
LEZ144>147.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...TK
MARINE...KUBINA
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
832 PM MST WED NOV 20 2013
.UPDATE...
ISSUED AT 806 PM MST WED NOV 20 2013
RADAR ECHOES HAVE BEEN ON THE INCREASE THE PAST COUPLE HOURS
ACROSS NERN WY INTO NWRN SD UNDER AREAS OF MID LVL FRONTOGENESIS.
HOWEVER...THIS SNOW IS LIKELY FIGHTING BOTH DRIER AIR ALOFT (SEE 00Z
KUNR SOUNDING) AND SOME DRIER SURFACE AIR WITH HIGH BUILDING QUICKLY
THROUGH MT. WOULD BE SURPRISED TO SEE MORE THAN AN INCH OR TWO FROM
THIS ACTIVITY. ATTENTION FOR LATER TONIGHT AND THURSDAY TURNS TOWARD
THE SHORT WAVE CURRENTLY LIFTING NEWD FROM FAR ERN UT. THIS WAVE
WILL ALLOW SNOW TO DEVELOP FURTHER SOUTH ACROSS THE CWFA LATER
TONIGHT AND THURSDAY...AND THE WINTER WX ADVISORY FOR SWRN/SCNTRL SD
STILL LOOKS PRETTY GOOD. BASED ON SOME OF THE EARLY 00Z MODEL
RUNS...AREAS ACROSS PARTS OF NERN WY INTO THE NRN BLKHLS AREA MAY
NOT GET QUITE AS MUCH SNOW AS PREVIOUSLY EXPECTED...AND WILL LET THE
MIDNIGHT SHIFT LOOK FURTHER AS TO WHETHER OR NOT THAT PORTION OF THE
ADVISORY CAN BE CANCELLED EARLY.
AS FAR AS THE WIND ADVISORY IS CONCERNED...GUSTS TO AROUND 40KTS
HAVE BEEN OBSERVED AT BOTH RAP AND RCA THE PAST FEW HOURS. DO
EXPECT THESE WINDS TO BEGIN RELAXING SLIGHTLY IN THE NEXT COUPLE
HOURS AS BEST PRES RISES SHIFT SOUTH OF THE CWFA. THUS...THE
ADVISORY IN EFFECT UNTIL MIDNIGHT FOR THE ERN SLOPES AND ADJACENT
PLAINS LOOKS GOOD.
DID LOWER SNOW AMOUNTS SLIGHTLY FOR THURSDAY OVER PARTS OF NERN WY
INTO WCNTRL SD AS EARLY 00Z FCST MODELS ARE SHIFTING HIGHER PCPN
TOTALS A TAD FURTHER SOUTH. FORECAST UPDATES WILL BE ISSUED
SHORTLY.
UPDATE ISSUED AT 503 PM MST WED NOV 20 2013
SNOW HAS DEVELOPED IN NERN WY INTO THE NRN BLKHLS...SO WENT AND
STARTED THE WINTER WX ADVISORY IMMEDIATELY THOSE AREAS. ALSO...SOME
LIGHT FREEZING DRIZZLE HAS DEVELOPED IN THE ERN FOOTHILLS INCLUDING
THE RAPID CITY AREA...SO HAVE UPDATED THE FCST TO ACCOUNT FOR THIS.
REST OF FCST UNCHANGED AT THIS TIME.
&&
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 307 PM MST WED NOV 20 2013
CURRENT SURFACE ANALYSIS SHOWS INITIAL ARCTIC FRONT TO THE SOUTH
OF THE CWA NOW...WITH COLDER AIR IN PLACE ACROSS MUCH OF THE
PLAINS. IT IS STILL RELATIVELY MILD OVER FAR SOUTHWESTERN
SD...PORTIONS OF NORTHEASTERN WY...AND THE HIGHER BLACK HILLS AS
FIRST SHOT OF COLD AIR IS SHALLOW. SECONDARY AND STRONGER PUSH OF
ARCTIC AIR WILL SLIDE IN LATE THIS AFTERNOON AND EVENING...BRINGING
COLDEST AIR OF THE SEASON SO FAR TO THE AREA FOR THE LATTER PART
OF THE WEEK.
UPPER LEVEL ANALYSIS SHOWS SHORTWAVE ENERGY TO THE NORTH AND WEST OF
THE AREA...FROM WESTERN ND...THROUGH EASTERN MT...AND WESTERN WY.
PCPN CONTINUES TO REMAIN NORTH AND WEST OF THE CWA SO FAR. BUT AS
THIS ENERGY SLIDES SOUTH AND EAST THIS EVENING WITH THE
FRONT...LIGHT SNOW WILL DEVELOP OVER MUCH OF THE AREA...ESPECIALLY
NORTHERN AND WESTERN PORTIONS OF THE CWA. SOME LIGHT
ACCUMULATIONS...MOSTLY AN INCH OR LESS...CAN BE EXPECTED OVER
NORTHERN AND WESTERN AREAS. LOWS TONIGHT WILL MOSTLY BE IN THE
TEENS...WITH SOME SINGLE DIGITS EXPECTED OVER NORTHERN AREAS.
GUSTY WINDS WILL DEVELOP BEHIND THE SECONDARY PUSH OF ARCTIC AIR AS
PRESSURE GRADIENT TIGHTENS. THE STRONGEST WINDS WILL BE AROUND THE
RAPID CITY AREA AND ADJACENT PLAINS TO THE NORTH AND EAST THIS
EVENING. HAVE DECIDED TO ISSUE A WIND ADVISORY FOR AREAS FROM BUTTE
CO TO EASTERN PENN CO. WINDS WILL GRADUALLY DECREASE OVERNIGHT.
A SECONDARY WAVE WILL PUSH EAST ACROSS WY AND THE CENTRAL PLAINS
LATE TONIGHT AND THURSDAY. LIGHT TO MODERATE SNOW WILL DEVELOP
ACROSS EASTERN WY AND TRACK EAST ACROSS SOUTHERN SD AND WESTERN NEB.
WILL ISSUE A WINTER WEATHER ADVISORY FOR WESTERN AND SOUTHERN
PORTIONS OF THE CWA FOR LATE TONIGHT AND THURSDAY. AT THIS POINT IT
LOOKS LIKE 2 TO 5 INCHES OF SNOW CAN GENERALLY BE EXPECTED ACROSS
MUCH OF NORTHEASTERN WY...AS WELL AS SOUTHWEST AND SOUTH CENTRAL SD.
THE HIGHER AMOUNTS WILL LIKELY BE NEAR THE SD/NEB BORDER WHERE THERE
IS A BETTER CHANCE FOR BANDED SNOWFALL. FORECAST SOUNDINGS SHOW THE
DENDRITIC GROWTH ZONE WILL BE FAVORABLE FOR LOCALLY HEAVIER SNOWFALL
AS WELL. SNOWFALL AMOUNTS WILL TAPER OFF DRASTICALLY TO THE NORTH OF
I-90 ON THURSDAY...WITH LITTLE OR NO SNOWFALL ACROSS MUCH OF
NORTHWESTERN SD. CONDITIONS WILL IMPROVE FROM WEST TO EAST IN THE
AFTERNOON...WITH CLEARING SKIES IN THE EVENING. TEMPS WILL REMAIN
WELL BELOW AVERAGE...WITH HIGHS MOSTLY IN THE MID TEENS TO LOWER
20S. LOWS THURSDAY NIGHT WILL RANGE FROM THE SINGLE DIGITS TO BELOW
ZERO IN THE USUAL COLD SPOTS.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 307 PM MST WED NOV 20 2013
UPPER FLOW BECOMES HIGHLY AMPLIFIED LATE THIS WEEK WITH A LONGWAVE
TROUGH SITUATED OVER THE EASTERN U.S. AND A REX BLOCK OVER THE WEST
COAST. ARCTIC SURFACE HIGH SETTLES INTO THE CENTRAL PLAINS ON
FRIDAY...WITH SOUTH TO SOUTHWEST RETURN FLOW ALLOWING TEMPERATURES
TO MODERATE INTO THE 20S AND 30S. HOWEVER REINFORCING SURGE OF
ARCTIC AIR IS ON TRACK TO ARRIVE LATE FRIDAY INTO SATURDAY. UPPER
LEVEL PATTERN IS FORECAST TO SHIFT SLIGHTLY EASTWARD DURING THE LAST
HALF OF THE WEEKEND...ALLOWING MILDER TEMPERATURES TO RETURN TO THE
AREA FOR SUNDAY INTO MONDAY. ANOTHER ARCTIC HIGH WILL SLIDE THROUGH
ON TUESDAY...WITH A SMALL REBOUND IN TEMPS FOR WEDNESDAY.
&&
.AVIATION...FOR THE 00Z/06Z TAFS THROUGH 00Z/06Z THURSDAY EVENING
ISSUED AT 830 PM MST WED NOV 20 2013
THE CHANCE FOR SNOW WILL INCREASE TONIGHT INTO THURSDAY AS UPPER
LEVEL ENERGY OVERRUNS THE COLDER ARCTIC AIR AT THE SURFACE.
EXPECT WDSPRD MVFR/IFR CONDITIONS ACROSS THE FORECAST AREA...WITH
AREAS OF LIFR ESPECIALLY FROM NERN WY THROUGH SWRN/SCNTRL SD.
CONDITIONS WILL BEGIN TO IMPROVE FROM NORTHWEST TO SOUTHEAST
THURSDAY AFTN. GUSTY NORTHERLY WINDS TO AROUND 40KTS...ESPECIALLY
NEAR THE KRAP TERMINAL...WILL GRADUALLY DECREASE AFTER MIDNIGHT
TONIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 2 PM MST THURSDAY FOR SDZ024-025-
028.
WINTER WEATHER ADVISORY FROM 5 AM MST /6 AM CST/ TO 5 PM MST /6
PM CST/ THURSDAY FOR SDZ030-042>044-046-047-049-074.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM MST
THURSDAY FOR SDZ027-029-041.
WIND ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR SDZ012-013-026-030-
031-072>074.
WY...WINTER WEATHER ADVISORY UNTIL 2 PM MST THURSDAY FOR WYZ054>058-
071.
&&
$$
UPDATE...JOHNSON
SHORT TERM...26
LONG TERM...15
AVIATION...JOHNSON
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
319 PM CST TUE NOV 19 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT
QUITE A CHANGE COMING IN THE SHORT TERM FROM THIS AFTERNOON
THROUGH THURSDAY NIGHT. FOR TONIGHT...EXPECT RR QUAD JET INDUCED
HIGH CLOUDS TO MOVE ON THIS EVENING WHILE MORE HIGH CLOUDS SPREAD
IN FROM THE WEST. BREEZY SOUTH WINDS WILL DECREASE THIS EVENING
WITH WINDS BECOMING NORTHWEST THROUGH NORTH BY MORNING AS A WEAK
SURFACE LOW PRESSURE TROUGH MOVES THROUGH. TEMPERATURES WILL NOT
FALL OFF MUCH TONIGHT WITH THE MILD AIR MASS REMAINING. LOWS ARE
EXPECTED TO RANGE FROM AROUND 30 DEGREES NORTH CENTRAL TO THE MID
TO UPPER 30S IN THE WATERTOWN/ORTONVILLE AREA. OTHERWISE...HIGHS
ON WEDNESDAY WILL LIKELY BE IN THE MORNING AS AN ARCTIC BOUNDARY
PUSHES IN DURING THE AFTERNOON WITH NORTH WINDS PICKING UP AND
TEMPERATURES FALLING ACROSS THE NORTH. EXPECT WINDS TO BECOME
BLUSTERY AT 15 TO 30 MPH WITH HIGHER GUSTS. THE OTHER ISSUE WILL
BE THE LIGHT SNOW DEVELOPING ALONG AND BEHIND THE SURFACE COLD
FRONT. MID LEVEL FRONTOGENESIS ALONG WITH SOME JET STREAK HELP
WILL BRING LIGHT SNOW TO NORTH CENTRAL SOUTH DAKOTA BY LATE
AFTERNOON. THE MODELS INDICATE LESSER AMOUNTS OF LIFT AND QPF AS
THIS REGION DESCENDS SOUTH ACROSS OUR CWA THROUGH WEDNESDAY NIGHT.
THUS...HAVE LIKELY CHANCES EARLY DIMINISHING THROUGH THE NIGHT.
SNOWFALL AMOUNTS SHOULD BE GENERALLY BELOW AN INCH BY THURSDAY
MORNING. ARCTIC AIR ENCOMPASSES THE ENTIRE CWA ON THURSDAY WITH
LESS WIND. MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED ON
THURSDAY WITH HIGHS IN THE 20 TO 25 DEGREE RANGE ACROSS THE CWA.
THE MODELS THEN SHOW AN UPPER LEVEL LOW PRESSURE TROUGH AND THE
ASSOCIATED LIFT SWINGING OVER THE REGION THURSDAY AND THURSDAY
EVENING. WITH MUCH OF THE NORTHERN CWA UNDER LOW LEVEL DRY
AIR...EXPECT THE BEST CHANCES OF LIGHT SNOW WITH THIS SYSTEM TO
BE FROM PIR TO HURON TO ATY. EXPECT MORE CLOUD COVER AND LIGHT
SNOW TO SPREAD QUICKLY WEST TO EAST ON THURSDAY ACROSS MAINLY THE
SOUTHERN CWA. COULD HAVE SOME MORE SNOWFALL ACCUMULATIONS OF AN INCH
OR TWO. THE LIGHT SNOW WILL END QUICKLY THURSDAY NIGHT WITH
CLEARING SKIES IN BEHIND AND SINGLE DIGIT LOWS.
.LONG TERM...FRIDAY THROUGH TUESDAY
NORTHWEST FLOW ALOFT WILL DOMINATE THE LONG TERM PORTION OF THE
FORECAST. A SURFACE LOW PRESSURE SYSTEM PASSING ACROSS THE GREAT
LAKES REGION ON FRIDAY WILL ALLOW FOR BITTER ARCTIC COLD
TEMPERATURES TO FILTER INTO THE AREA BY FRIDAY NIGHT. BY 12Z
SATURDAY TEMPERATURES AT H85 RANGE IN THE MID TO UPPER TEENS BELOW
ZERO...WHICH IS APPROACHING TWO STANDARD DEVIATIONS BELOW NORMAL. LOW
TEMPERATURES SHOULD EASILY DROP TO THE SINGLE DIGITS ON EITHER
SIDE OF ZERO BY SATURDAY MORNING. THE SURFACE HIGH PRESSURE WILL
EXIT THE REGION ON SATURDAY NIGHT ALLOWING FOR WAA TO SPREAD INTO
THE CWA. TEMPERATURES THROUGH THE REST OF THE PERIOD WILL BE
AROUND NORMAL...DUE TO EXPECTED SNOW COVER. NO SIGNIFICANT
PRECIPITATION CHANCES ARE EXPECTED FOR THE PERIOD.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
PREVAILING VFR CONDITIONS ARE EXPECTED FOR ALL TERMINALS THROUGH
THE VALID TAF PERIOD. AN AREA OF LOW PRESSURE WILL PASS THROUGH THE
REGION DRY WITH ONLY HIGH CIRRUS EXPECTED. STRONG SOUTHERLY WINDS
AFFECTING THE TERMINALS OF KABR/KATY WILL DIMINISH BELOW 12 KNOTS LATER
THIS EVENING. WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE
MORNING HOURS ON WEDNESDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...MOHR
LONG TERM...SD
AVIATION...SD
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
856 PM CST WED NOV 20 2013
.UPDATE...
MANY AREAS SAW A MIX OF RAIN/SNOW/SLEET THIS EVENING AS THE
TEMPERATURE PROFILES WERE PRECARIOUSLY HOVERING AROUND THE 0C
MARK. THE HEAVIER PRECIP FELL AS A MIX...BUT TURNED TO MOSTLY
LIQUID WITH THE LIGHTER INTENSITY STUFF...THAT/S TYPICAL IN THESE
SITUATIONS. THE SHORT WAVE RESPONSIBLE FOR THE PRECIP IS LIFTING
OFF TO THE NORTHEAST THIS EVENING. THERE IS SOME RESIDUAL WARM AIR
ADVECTION CONTINUING THROUGH ABOUT 06Z. RADAR TRENDS SHOW THE
PRECIP IS ENDING ACROSS OUR WESTERN CWA COINCIDENT WITH THE
EXITING SHORT WAVE. BUT THE HRRR SUGGESTS WE COULD SEE SOME LIGHT
DEVELOPMENT BACK THERE YET DUE TO THE WAA. ALL OF PRECIP SHOULD
MOVE EAST OF THE AREA BY OR SHORTLY AFTER MIDNIGHT. WE SHOULD HAVE
A QUIET PERIOD THROUGH THURSDAY MORNING. ANOTHER SHORT WAVE MOVING
THROUGH COULD BRING SOME LIGHT PRECIP THURSDAY AFTERNOON INTO
THURSDAY NIGHT.
&&
.AVIATION/06Z TAFS/...
THE PRECIPITATION SHOULD EXIT THE AREA BY THE TIME THE NEXT SET OF
TAFS GOES INTO EFFECT AT 06Z. MOISTURE WILL LINGER ACROSS THE AREA
AHEAD OF AN APPROACHING COLD FRONT TO THE NORTH. CIGS SHOULD GO
DOWN TO MVFR LEVELS MOST PLACES OVERNIGHT...LATEST IN THE
MILWAUKEE/KENOSHA AREAS. THE COLD FRONT WILL MOVE THROUGH LATE
THURSDAY AFTERNOON. WINDS TURNING TO THE NORTHEAST BEHIND THE
FRONT COULD BRING IN SOME IFR CIGS TO KUES/KMKE/KENW THURSDAY
NIGHT. MORE PRECIPITATION IS POSSIBLE THURSDAY
AFTERNOON...CONTINUING INTO THURSDAY NIGHT. IT WOULD BE RAIN
DURING THE DAY...BUT CHANGE TO LIGHT SNOW IN THE WAKE OF THE COLD
FRONT THURSDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 341 PM CST WED NOV 20 2013/
SHORT TERM...
TONIGHT AND THURSDAY...FORECAST CONFIDENCE IS MEDIUM
AREA OF PRECIPITATION HAS MOVED INTO THE WESTERN COUNTIES IN THE
PAST HOUR...AND SHOULD CONTINUE TO SHIFT EAST NORTHEAST INTO THE
EVENING. SEEING SOME LIGHT SNOW REPORTS AT OBSERVATION SITES TO THE
WEST OF THE AREA IN THE PAST HOUR OR TWO...BUT HAVE CHANGED BACK TO
LIGHT RAIN. LOOKING AT RAP/NAM/GFS FORECAST SOUNDINGS IN THE FAR
WESTERN COUNTIES...THE WET BULB PROFILE SUGGESTS THAT A LIGHT RAIN
AND LIGHT SNOW MIX CAN BE EXPECTED INTO THE EARLY EVENING
HOURS...BEFORE SLIGHTLY MILDER AIR MOVES IN BY MID EVENING. ADDED A
TENTH OR SO OF SNOW ACCUMULATION IN THIS AREA...EXPECTED TO BE
MAINLY ON GRASSY AREAS. THE REST OF THE AREA SHOULD SEE THE LIGHT
RAIN SPREAD ACROSS THE REST OF THE AREA THIS EVENING...EXITING
FROM SOUTHWEST TO NORTHEAST AFTER MIDNIGHT.
CLOUDS SHOULD HANG AROUND LATER TONIGHT AND THURSDAY...AHEAD OF NEXT
SYSTEM MOVING INTO THE REGION. THERE WILL BE A PERIOD OF QUIET
WEATHER LATER TONIGHT INTO THURSDAY MORNING...BEFORE POPS RETURN
THURSDAY AFTERNOON. SOME UNCERTAINTY HERE WITH MOISTURE...AS NAM IS
SOMEWHAT DRY VERSUS THE MOISTER GFS. 500MB VORTICITY MAXIMUM PASSES
NORTHEAST THROUGH THE AREA DURING THE DAY. SYNOPTIC MODELS ARE
KEEPING MOST OF THE QPF JUST SOUTH OF THE AREA WITH THE BEST LOW
LEVEL FRONTOGENESIS RESPONSE.
THURSDAY NIGHT THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM
A COLD FRONT WILL SLOWLY MOVE SEWD ACROSS SRN WI THU NT CHANGING
LIGHT RAIN TO LIGHT SNOW. THE PRECIPITATION WILL FORM AS A WEAK
VORTICITY MAXIMUM MOVES NEWD ACROSS THE AREA THU EVENING WHILE
FRONTOGENESIS IN THE 850-700 MB LAYER AFFECTS THE AREA LATER AT
NIGHT THROUGH FRI AM. THE BEST FRONTOGENESIS WILL SET UP TOWARD
CENTRAL WI AND THE NRN CWA. OVERALL THOUGH...THE LIFT WILL REMAIN
WEAK AND QPF WILL RANGE FROM 0.10-0.20 INCHES WITH THE MOST SNOW
ACCUM IN THE NW CWA WHERE AROUND ONE INCH IS EXPECTED.
NWLY WINDS AND COLD...DRY AIR ADVECTION WILL CONTINUE FRI AM BUT
WEAKEN IN THE AFTERNOON AS A RIDGE OF HIGH PRESSURE WILL MOVE
SOUTH THROUGH THE AREA INTO EARLY EVENING. SOME SUNSHINE IS
EXPECTED IN THE AFTERNOON BUT TEMPS WILL ONLY WARM SLIGHTLY FROM
THE MORNING LOWS.
CANADIAN LOW PRESSURE WILL TRACK ACROSS THE NORTHERN AND EASTERN
GREAT LAKES FRI NT AND SAT IN RESPONSE TO A LONGWAVE POLAR TROUGH
MOVING EAST ACROSS CANADA AND THE NRN USA. AN ARCTIC COLD FRONT
WILL PASS FRI NT INTO SAT WITH 850 MB TEMPS FALLING TO -18C. A
DRY FRONTAL PASSAGE IS EXPECTED BUT SCT-BKN STRATOCUMULUS ARE
EXPECTED ON SAT. HIGHS ONLY IN THE 20S ON SAT WITH LOWS SAT NT IN
THE UPPER SINGLE DIGITS TO TEENS.
LONG TERM...
SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE MEDIUM
ARCTIC HIGH PRESSURE WILL MOVE EWD ACROSS WI SUN AM AND QUICKLY
MOVE EAST AS ANOTHER CANADIAN LOW WILL MOVE EWD ACROSS SRN CANADA.
SWLY WINDS AND WARM ADVECTION WILL PREVAIL FROM SUN AFTERNOON
THROUGH MON AM. THEN ANOTHER ARCTIC COLD FRONT WILL MOVE SOUTH
THROUGH THE UPPER MS RIVER VALLEY AND GREAT LAKES. THE ARCTIC HIGH
WILL ARRIVE OVER WI FOR WED. COLD AND MAINLY DRY WX IS EXPECTED.
AVIATION/00Z TAFS/...
LIGHT RAIN SHOULD SPREAD EASTWARD ACROSS TAF SITES...FROM BETWEEN
22Z AT MADISON...TO AROUND 00Z THURSDAY AT THE EASTERN SITES. THE
LIGHT RAIN WILL END BETWEEN 05Z AT MADISON...AND 08Z AT THE EASTERN
TAF SITES. MVFR CEILINGS AND VISIBILITIES ARE EXPECTED ONCE THE RAIN
MOVES IN...AND CONTINUING THROUGH THE REST OF TONIGHT. THE MVFR
CEILINGS WILL LINGER ON THURSDAY.
THERE IS A CHANCE FOR SOME LIGHT SNOW TO MIX IN WITH THE RAIN AT
MADISON UNTIL AROUND 03Z THURSDAY...BUT CONFIDENCE IS MIXED SO LEFT
OUT MENTION IN TAFS.
SOUTHEAST WINDS WILL CONTINUE TO WEAKEN TONIGHT. LIGHT AND VARIABLE
WINDS ARE THEN EXPECTED LATER TONIGHT INTO THURSDAY...BEFORE
BECOMING LIGHT NORTH TO NORTHEAST LATE THURSDAY AFTERNOON.
MARINE...
SMALL CRAFT ADVISORY CONTINUES ACROSS THE NEARSHORE WATERS OF LAKE
MICHIGAN UNTIL 10Z THURSDAY. SOUTH SOUTHEAST WINDS WILL GRADUALLY
DIMINISH TONIGHT...ALONG WITH THE HIGH WAVES.
WINDS AND WAVES MAY REACH SMALL CRAFT ADVISORY LEVELS AT TIMES
THURSDAY NIGHT INTO EARLY NEXT WEEK...AS GUSTY OFFSHORE WINDS ARE
EXPECTED. HIGH WAVES TOWARD THE OPEN WATERS ARE POSSIBLE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM CST THURSDAY FOR LMZ643>646.
&&
$$
UPDATE...DAVIS
TONIGHT/THURSDAY AND AVIATION/MARINE...WOOD
THURSDAY NIGHT THROUGH WEDNESDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1128 AM CST TUE NOV 19 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS.
THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE
NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK
STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL
DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS
MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND
CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE
RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND
GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE
THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO
HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT
SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING
ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS
THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR
TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND
INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE.
FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW
THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF
A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST
SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON
WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO
50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A
TENTH OF AND INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF
THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY
DECLINE DURING THE EVENING.
ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS...
ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM
SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE
AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR
JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE
COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE
TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS
THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO
THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT.
HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON
WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE
MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE
TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD
POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT
SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES
EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT
PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND
SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN
AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE.
ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD
ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND
OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES
THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS
WILL BE LESS THAN A HALF INCH.
ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY
TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR
WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM
HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH
TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECMWF IS A BIT
LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S.
SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE
ALL BLEND MAXIMUM TEMPERATURES.
SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB
TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE
NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE
SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW
THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN
COLDER.
LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY
BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN
THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE
IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED
WITH THE ALL BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1128 AM CST TUE NOV 19 2013
PRESSURE GRADIENT ACROSS THE UPPER MIDWEST WILL CONTINUE TO TIGHTEN
FOR THIS AFTERNOON/TONIGHT AS LOW PRESSURE DEEPENS INTO THE CENTRAL/
NORTHERN PLAINS. SOUTHEAST TO SOUTH GRADIENT WINDS ARE GOING TO
INCREASE INTO THE 10-20KT G20-30KT RANGE THRU THE AFTERNOON AND
CONTINUE TONIGHT INTO WED. WINDS WILL INCREASE ON TOP OF THE
NOCTURNAL INVERSION /AROUND 2K FT/ TONIGHT...TO 50-60KTS. CONTINUED
THE MENTION OF LLWS AT BOTH KRST/KLSE IN THE 03Z-15Z TIME-FRAME FOR
THE RAPID SPEED AND DIRECTIONAL CHANGE OF THE WIND IN THE SFC-2K FT
LAYER.
CLOUDS TODAY WILL BE SCT-BKN HIGH CLOUDS. SOME MID LEVEL MOISTURE
ARRIVES ON THE SOUTHERLY FLOW TONIGHT...WITH CLOUDS EXPECTED TO BE
IN THE 8K-10K FT RANGE. MOISTURE CONTINUES TO DEEPEN ON WED ALONG
WITH AN INCREASE OF LIFTING. MODEL CONSENSUS CONTINUE TO PRODUCE
SOME -RA IN/AROUND THE AREA BY LATE MORNING. INCLUDED VCSH AND CIGS
IN THE 6K-7K FT RANGE AFTER 15Z WED. ANY PRECIP LATE WED MORNING
LOOKS TO BE LIGHT ENOUGH TO HAVE MINIMAL IMPACT ON VSBYS. BIT MORE
WIDESPREAD -RA WED AFTERNOON MAY PRODUCE SOME MVFR VSBYS AFTER 18Z
WED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
515 AM CST TUE NOV 19 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS.
THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE
NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK
STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL
DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS
MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND
CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE
RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND
GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE
THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO
HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT
SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING
ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS
THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR
TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND
INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE.
FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW
THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF
A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST
SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON
WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO
50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A
TENTH OF AND INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF
THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY
DECLINE DURING THE EVENING.
ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS...
ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM
SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE
AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR
JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE
COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE
TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS
THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO
THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT.
HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON
WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE
MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE
TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD
POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT
SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES
EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT
PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND
SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN
AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE.
ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD
ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND
OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES
THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS
WILL BE LESS THAN A HALF INCH.
ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY
TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR
WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM
HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH
TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECMWF IS A BIT
LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S.
SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE
ALL BLEND MAXIMUM TEMPERATURES.
SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB
TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE
NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE
SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW
THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN
COLDER.
LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY
BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN
THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE
IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED
WITH THE ALL BLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 515 AM CST TUE NOV 19 2013
PRESSURE GRADIENT WILL TIGHTEN TODAY ON THE BACKSIDE OF AN EASTWARD
MOVING HIGH PRESSURE SYSTEM. WINDS WILL INCREASE QUICKLY - BY
MID/LATE MORNING - FROM A SOUTHERLY DIRECTION. THERE WILL BE SOME
GUSTINESS...BUT MINIMALIZED SOMEWHAT AS LOW LEVEL WINDS ARE NOT
UNDIRECTIONAL AND MIXING IS INHIBITED SOMEWHAT. THE WINDS WILL STAY
UP TONIGHT...WITH BUFKIT SOUNDINGS VIA THE RAP/NAM/GFS ALL POINTING
TO A 50-60 KT 2 KFT JET DEVELOPING BY 03Z. LLWS A CONCERN AS A
RESULT...AND WILL CONTINUE MENTION AT KLSE...AND ADD TO THE TAF FOR
KRST.
SOME HIGH THIN CLOUDS WILL SWEEP ACROSS THE REGION TODAY...WITH SOME
MID 8-10 KFT CLOUDS TONIGHT. VFR CONDITIONS ARE ANTICIPATED INTO
WEDNESDAY MORNING.
&&
.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
348 AM CST TUE NOV 19 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS.
THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE
NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK
STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL
DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS
MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND
CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE
RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND
GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE
THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO
HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT
SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING
ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS
THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR
TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND
INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE.
FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW
THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF
A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST
SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON
WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO
50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A
TENTH OF AND INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF
THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY
DECLINE DURING THE EVENING.
ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS...
ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM
SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE
AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR
JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE
COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE
TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS
THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO
THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT.
HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON
WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE
MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE
TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD
POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT
SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES
EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT
PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND
SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN
AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE.
ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD
ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND
OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES
THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS
WILL BE LESS THAN A HALF INCH.
ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY
TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR
WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM
HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH
TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECWMF IS A BIT
LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S.
SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE
ALL BLEND MAXIMUM TEMPERATURES.
SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB
TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE
NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE
SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW
THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN
COLDER.
LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY
BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN
THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE
IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED
WITH THE ALL BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1125 PM CST MON NOV 18 2013
THE MAIN CONCERN WILL BE INCREASING WINDS TUE AND LLWS TUE EVENING.
THE SFC HIGH PRESSURE RIDGE AXIS WAS OVER THE AREA LATE THIS
EVENING. WINDS WILL BE LIGHT THRU MUCH OF THE OVERNIGHT HOURS AS THE
SFC HIGH DRIFTS ACROSS THE AREA. BY 12Z THE RIDGE AXIS WILL HAVE
MOVED INTO EASTERN WI...WITH WINDS BECOMING SOUTH TO SOUTHEAST AND
INCREASING LATE TONIGHT AND THRU TUE MORNING. BY TUE AFTERNOON THE
HIGH WILL BE IN OH. A TIGHT PRESSURE GRADIENT WILL ONCE AGAIN BE
OVER THE UPPER MIDWEST BY TUE AFTERNOON AND FOR TUE NIGHT. BY TUE
AFTERNOON SOUTHEAST-SOUTH WINDS WILL INCREASE INTO THE 10-20KT G20-
30KT RANGE. THESE WINDS WILL CONTINUE TUE NIGHT...BUT AS THE NIGHT-
TIME INVERSION DEVELOPS...WINDS 1500-2000FT AGL ARE GOING TO
INCREASE INTO THE 50KT RANGE FROM THE SOUTH-SOUTHWEST. INCLUDED LLWS
AT KLSE AFTER 00Z WED.
THE AIRMASS WITH THE HIGH AND ON THE BACK SIDE OF THE HIGH IS DRY.
SKC EXPECTED TONIGHT...MAINLY SCT-BKN HIGH CLOUDS TUE THEN SCT 8K-
10K FT CLOUDS TUE NIGHT...WITH VFR VSBYS THRU THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
359 AM EST THU NOV 21 2013
.DISCUSSION...
CURRENTLY...
EVENING SOUNDINGS CAME IN QUITE MOIST WITH BOTH KTBW/KMFL PWAT
VALUES NEARING 2.0". EVEN SO...LATEST RUC ANALYSIS SHOWS A POCKET OF
RELATIVELY DRY AIR IMMEDIATELY UPSTREAM WITH H100-H70 MEAN RH VALUES
DROPPING FROM AOA 90PCT OVER THE PENINSULA TO BLO 75PCT N OF THE
BAHAMAS. WEAK UPR LVL SUPPORT AS THE H30-H20 WINDS OVERHEAD ARE ARE
AOB 50KTS. HOWEVER...LCL H85-H50 VORT MAXES ALONG THE WEAKENING
BOUNDARY OVER S FL HAVE BEEN PROVIDING SUFFICIENT MID LVL SUPPORT TO
MAINTAIN SCT SHRA ACTIVITY OVER THE ATLC. DESPITE FAIRLY COOL TEMPS
ALOFT (H70 ARND 6C...H50 BTWN -8C AND -9C) LAPSE RATES ACRS THE
REGION ARE QUITE WEAK...GENERALLY AOB 5.5C/KM.
TODAY-TONIGHT...
THE CENTER OF THE LARGE H100-H70 RIDGE AXIS BLANKETING THE ERN CONUS
WILL PUSH OFF THE NEW ENGLAND COAST AND STEADILY WEAKEN. AS IT
DOES...ITS SRN EXTENSION TO BECOME DOMINANT OVER THE MID ATLC. THE
STATIONARY FRONTAL BOUNDARY OVER S FL WILL WASH OUT...ALLOWING THE
RELATIVELY TIGHT PGRAD TO THE N TO EXPAND SWD...RESULTING IN A DEEP
AND STEADY ERLY BREEZE ACRS CENTRAL FL.
DESPITE DECREASING MOISTURE UPSTREAM AND A WEAK THERMODYNAMIC
PROFILE...SHRA ACTIVITY OVER THE ATLC HAS PERSISTED FOR SVRL HRS.
DEPTH AND STRENGTH OF THE ONSHORE FLOW WILL CONTINUE TO PUSH POCKETS
OF ENHANCED MOISTURE ONSHORE...WILL STICK CLOSE TO MOS GUIDANCE FOR
PRECIP AND WORD FOR COVERAGE...NO THUNDER AS THE SUPPORT AND
INSTABILITY OVERHEAD AND UPSTREAM ARE TOO WEAK. WILL GO WITH
50-60PCT ALONG THE TREASURE COAST...40-50PCT SPACE COAST...
DECREASING TO 30-40PCT OVER THE INTERIOR FOR TODAY...DECREASING TO
20-30PCT S OF I-4...LESS THAN 20PCT N OF I-4.
DEEP ONSHORE FLOW AND MID/UPR LVL CLDS WILL RESULT IN FAIRLY UNIFORM
MAX TEMPS IN THE U70S ALONG THE COAST...L80S INTERIOR. MIN TEMPS
WILL BE QUITE MILD FOR LATE FALL...U60S/M70S ALONG THE COAST...
M/U60S INTERIOR...A SOLID 10-15F ABV AVG.
FRI...
HIGH PRESSURE RIDGE VICINITY OF THE CAROLINAS EARLY WILL WEAKEN
AND SHIFT SOUTHEAST AS A COLD FRONT PUSHES TOWARDS THE SOUTHEAST
STATES. THIS WILL CAUSE ONSHORE FLOW TO WEAKEN. THE GFS HAS GONE
BACK TO A LITTLE MORE DRYING WITH THIS RUN AND WITH THE WEAKENING
LOW LEVEL FLOW...THE MODEL FOCUSES POPS IN SOUTHERN SECTIONS...WITH
VALUES LESS THAN 10 PERCENT IN THE NORTH. WITH SOME WEAK RIDGING
ALOFT AND SUBSIDENCE WILL FOLLOW CLOSE TO THE MOS NUMBERS.
WEEKEND...
WEAK HIGH PRESSURE RIDGE WILL EXTEND OVER THE AREA ON SAT THEN A
COLD FRONT IS SHOWN ON OUR DOORSTEP FIRST THING SUNDAY MORNING.
PRE FRONTAL CONVERGENCE WILL BE WEAK SO WILL JUST MAINTAIN A
SLIGHT CHANCE FOR SHOWERS AS PER MOS GUIDANCE...EVEN THOUGH MOS IS
ALREADY SHOWING DRYING OCCURRING IN THE NORTH BY EARLY SUNDAY. THE
MAIN STORY SUNDAY WILL BE GUSTY NORTHERLY WINDS WHICH SHOULD
REQUIRE AT LEAST A LAKE WIND ADVISORY AND MAYBE EVEN A STRAIGHT
WIND ADVISORY AS 925 MB WINDS ARE FORECAST 25-30 KNOTS IN THE
AFTERNOON. TEMPS WILL CONTINUE ABOVE NORMAL SAT AND SAT NIGHT THEN
ON SUNDAY MAX TEMPS MAY STRUGGLE TO REACH 70 IN THE NORTH AND MID
70S CENTRAL. SOUTHERN SECTIONS MIGHT REACH THE UPPER 70S BEFORE
COLD ADVECTION KICKS IN.
MON-THU...
EARLY TO MID WEEK LOOKS LIKE A QUITE DYNAMIC PERIOD AS THE MODELS
ARE STILL DEVELOPING A LOW IN THE NORTHWEST GULF OF MEXICO ON MON
AND MOVING IT EAST/NORTHEAST THROUGH WED. THE GFS IS A TAD SLOWER
AND FARTHER SOUTH THAN THE ECMWF BUT OVERALL THE MODELS ARE IN
DECENT AGREEMENT.
ON MON...THE COOL/DRY AIR MASS WILL MODIFY AS LOW LEVEL FLOW
BECOMES EASTERLY. MOS HAS SLIGHT CHANCE POPS ACROSS THE SOUTH AS
SURFACE DEW POINTS ARE FORECAST TO MODIFY INTO THE UPPER 50S BUT
THE NORTH LOOKS TOO DRY FOR MENTIONABLE POPS WITH DEW POINTS IN THE
LOWER 50S.
MON NIGHT THE GFS SHOWS INCREASING EAST/SOUTHEAST LOW LEVEL FLOW
AND SOME ISENTROPIC LIFT DEVELOPING. EXPECT SOME ONSHORE MOVING
SHOWERS ALONG THE COAST AND THERE MAY ALSO BE SOME AREAS OF RAIN
BREAKING OUT. MOS POPS ARE AROUND 25 PERCENT AND WILL GO WITH THAT
ACROSS THE AREA.
FOR TUE AND WED...THE GFS SHOWS A BAND OF HIGHER MOISTURE LIFTING
NORTH ACROSS THE AREA TUE ALONG PSEUDO WARM FRONT. WITH
INCREASING LOW LEVEL WINDS IN RESPONSE TO LOW CENTER WHICH IS FORECAST
TO BE VICINITY MISSISSIPPI DELTA REGION...WILL INTRODUCE A SLIGHT
CHANCE FOR STORMS IN ADDITION TO BUMPING POPS TO 40 PERCENT
THROUGH THE PERIOD.
THE GENERAL SYNOPTIC PATTERN IS SUGGESTIVE OF A THREAT FOR STRONG-
SEVERE STORMS DUE TO DEEPENING LOW PRESSURE CLOSE TO THE STATE.
THE GFS SHOWED THE ASSOCIATED MID LEVEL SHORTWAVE TROUGH TAKING
ON A SLIGHT NEGATIVE TILT...HOWEVER QUITE STRONGLY DIFFLUENT FLOW
ALOFT SUGGESTS CONSIDERABLE DEBRIS CLOUDINESS OVERSPREADING THE
WARM SECTOR...LIMITING INSTABILITY.
TIMING IS FAR FROM CERTAIN AT THIS POINT AND THERE IS PLENTY OF
TIME TO REFINE THE FORECAST.
SNEAK PEAK FOR THANKSGIVING DAY...THE MODELS SHOW COLD FRONT EAST
OF THE AREA EARLY SO EXPECT A DRIER AIR MASS AND COOLER TEMPS.
&&
.AVIATION...
THRU 21/15Z...ERLY LLWS FL015 INTERIOR SITES...OCNL SFC WND G22KTS
ALONG THE COAST S OF KTIX...W OF KMLB-KOBE PREVAILING CIGS BTWN
FL060-080 WITH ISOLD MVFR COASTAL SHRAS N OF KTIX...E OF KMLB-KOBE
PREVAILING CIGS BTWN FL040-060 WITH SCT MVFR SHRAS.
BTWN 21/15Z-21/23Z...OCNL SFC WND G18-22KTS N OF KVRB-KISM...
PREVAILING CIGS BTWN FL040-060 WITH SCT MVFR SHRAS...BRIEF IFR VSBYS
IN +SHRAS.
AFT 21/23Z...PREVAILING CIGS BTWN FL080-100...CHC MVFR SHRAS S OF
KMLB-KOBE...SLGT CHC N OF KMLB-KOBE.
&&
.MARINE...
TODAY-TONIGHT...LCL DATA BUOY/C-MAN NETWORK SHOWING A CONSISTENT
15-20KTS OF ERLY FLOW WITH 5-7FT SEAS NEARSHORE AND 8-9FT OFFSHORE.
HOWEVER...BUOY012 IS STARTING TO PICK UP A NEW SWELL TRAIN...ONE
WITH DOMINANT PDS BTWN 11-12SEC AS OPPOSED TO BUOY008/009 WHOSE
DOMINANT PDS ARE BTWN 8-9SEC.
WHILE THE LONGER SWELL PD WILL HELP DAMPEN THE ROUGH SEAS...
CONDITIONS WILL REMAIN HAZARDOUS FOR SMALL CRAFT. THE CENTER OF
A LARGE HIGH PRES RIDGE OVER THE ERN CONUS WILL PUSH OFF THE NEW
ENGLAND COAST AND WEAKEN. THIS WILL ALLOW THE SRN EXTENSION OF THE
RIDGE TO BECOME DOMINANT AND BUILD OVER THE MID ATLC. LCL SFC/BNDRY
LYR WINDS WILL WEAKEN...ALBEIT SLOWLY..AS THE REDEVELOPING RIDGE
KEEPS A FAIRLY TIGHT PGRAD ACRS THE REGION...ONE CAPABLE OF
MAINTAINING A MODERATE TO FRESH ERLY BREEZE ACRS THE LCL ATLC. WILL
NEED TO ADJUST THE TIMING OF THE CURRENT SCA...AT MINIMUM PLANS ARE
TO EXTEND IT FOR THE OFFSHORE LEG THRU 22/09Z.
FRI-SAT...HIGH PRESSURE RIDGE NORTH OF THE AREA FRI WILL WEAKEN AND
SHIFT SOUTHEAST AHEAD OF A COLD FRONT. EASTERLY FLOW WILL
GRADUALLY WEAKEN FRI BUT THE COMBINATION OF WINDS AND SEAS SHOULD
PRODUCE POOR-HAZARDOUS CONDITIONS FOR SMALL CRAFT. WILL GO WITH AN
ADVISORY FOR SEAS THROUGH FRI AFTERNOON AS WINDS WILL BE CLOSE TO
15 KNOTS THEN AND SEAS STILL 5-8 FEET.
THE GOOD NEWS LOOKS TO BE THAT ON SAT THE WINDS WILL DIMINISH TO
5-10 KNOTS. CONDITIONS TRAVERSING THE INLETS MAY STILL BE
HAZARDOUS THOUGH AS SWELLS 4-5 FEET CONTINUE IN THE ATLANTIC.
SUN-MON...STRONG COLD FRONT IS STILL PROGGED TO SWEEP FROM THE
NORTHERN WATERS EARLY IN THE DAY TO SOUTH OF THE WATERS BY
AFTERNOON. MODEL LOW LEVEL WINDS STILL SUGGEST THAT NORTHERLY
WINDS GUSTING TO 30 KNOTS WILL BE POSSIBLE. THE FLOW WILL SWING
AROUND TO THE NORTHEAST/EAST ON MON AND STILL LOOK QUITE GUSTY
20-25 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 78 68 80 63 / 40 20 10 10
MCO 82 67 82 63 / 30 20 10 10
MLB 80 73 81 66 / 50 30 20 10
VRB 80 73 81 66 / 50 30 30 10
LEE 81 65 82 62 / 30 20 10 10
SFB 82 67 82 63 / 30 20 10 10
ORL 82 67 82 64 / 30 20 10 10
FPR 81 73 81 66 / 60 30 30 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-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.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 AM TO 4 PM EST
FRIDAY FOR COASTAL WATERS FROM FLAGLER BEACH TO VOLUSIA
BREVARD COUNTY LINE OUT 20 NM-COASTAL WATERS FROM SEBASTIAN
INLET TO JUPITER INLET OUT 20 NM-COASTAL WATERS FROM
VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET OUT 20 NM-
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...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
443 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE SLOWLY SLIDES DOWN THE NORTHEAST ATLANTIC COAST
TODAY AND FRIDAY. A STRONG COLD FRONT CROSSES THE REGION ON
SATURDAY. CANADIAN HIGH PRESSURE BUILDS INTO THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK...USHERING IN THE COLDEST
TEMPERATURES OF THE FALL SEASON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRONG ~1040MB (+2 STD DEV MSLP) HIGH OVER THE ST LAWRENCE RIVER
VALLEY THIS MORNING CONTINUES TO RIDGE OVER THE LOCAL AREA.
ALOFT...RIDGE HAS LOCATED OVER THE ERN CONUS AS THIS WEEKENDS
STORM SYSTEM TAKES SHAPE OVER SRN CANADA. H85 HIGH HAS LOCATED
OVER ERN NC WITH FLOW AROUND THE WRN PERIPHERY BECOMING S-SW BELOW
A STRONG SUBSIDENCE INVERSION. RETURN FLOW WILL ADVECT MOISTURE
OVER THE CAROLINAS NWD THIS MORNING. ALREADY BEGINNING TO SEE BKN-
OVC MID DECK SPREAD OVER THE LOCAL AREA. SHOWERS HAVE DEVELOPED
OFF THE SE NC COAST ALONG A WEAK COASTAL BOUNDARY EARLY THIS
MORNING. LATEST RUC GUIDANCE SUGGESTS THAT THE BOUNDARY WILL
LINGER THRU THE MORNING BEFORE WEAKENING. MODEST UPPER LEVEL
SUPPORT AND MOISTURE OVERRUNNING THE BOUNDARY WILL RESULT IN
ISOLATED SPRINKLES OVER MAINLY NE NC THRU MID MORNING. NO
MEASURABLE RAINFALL IS ANTICIPATED.
WITH AFOREMENTIONED STRONG HIGH TO THE NORTH AND RIDGING OVER THE
LOCAL AREA (CAD SETUP)...EXPECT CLOUD COVER TO CONTINUE TO THICKEN
THRU THE MORNING INTO THE AFTERNOON. WAA WILL ALSO ENHANCE THE
CLOUD COVER. OTHERWISE...SFC HIGH WILL BEGIN TO BREAK DOWN
TODAY...DRIFTING SWD OFF THE NE COAST BUT REMAINING RIDGED OVER
THE LOCAL AREA. RIDGE AXIS WILL PUSH OFFSHORE LATE TODAY...BUT WLY
FLOW WILL CONTINUE ALOFT. THE RESULTANT WAA WILL BE ENOUGH TO WARM
TEMPS INTO THE LOW-MID 50S INLAND TO UPPER 50S ALONG THE COAST
(SLIGHTLY BELOW NORMAL)...REGARDLESS OF CLOUDY SKIES AND
PERSISTENT ONSHORE FLOW. MODELS REMAIN RATHER AGGRESSIVE WITH LIGHT
RAIN/DRIZZLE TODAY BUT DRY LOW LEVELS WILL PREVENT ANY CHANCE FOR
PRECIP TO MATERIALIZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A STRONG COLD FRONT WILL CROSS THE LOCAL AREA LATE FRIDAY NIGHT
INTO EARLY SATURDAY MORNING...USHERING IN THE COLDEST AIR OF THE
FALL SEASON TO THE MID-ATLANTIC.
FRIDAY...
STRONG AMPLIFICATION OF NRN STREAM TROUGH ACROSS SRN CANADA AND
THE GREAT LAKES REGION WILL OCCUR FRIDAY. A LEAD SHORTWAVE WILL
PUSH AN ASSOCIATED COLD FRONT ACROSS THE OH VALLEY EARLY
FRI...REACHING THE CNTRL APPALACHIANS FRI AFTERNOON.
MEANWHILE...THE SFC HIGH WILL BREAK DOWN OVER THE REGION...WITH
SFC WINDS RETURNING TO THE SW. HOWEVER...WLY FLOW WILL CONTINUE
ALOFT...ADVECTING MOISTURE (+1 STD DEV PRECIP WATERS) FROM THE
KY/TN VALLEYS. INCREASING MOISTURE WILL REINFORCE THE CLOUD COVER
WITH MOSTLY CLOUDY-CLOUDY CONDITIONS EXPECTED AGAIN FRI.
INCREASING HEIGHTS/THICKNESSES AND H85 TEMPS +9C WILL TRANSLATE TO
TEMPS GENERALLY IN THE MID 60S...EVEN WITH CLOUD COVER. FRIDAY
WILL REMAIN DRY AS PRECIP WILL REMAIN ALONG THE FRONT OVER THE
CNTRL APPALACHIANS LATE FRIDAY.
FRIDAY NIGHT-SATURDAY...
LATEST MODEL GUIDANCE HAS BETTER RESOLVED THE DIFFERENCES WITH
THE LEADING SHORTWAVE FRIDAY...RESULTING IN BETTER AGREEMENT WITH
PUSHING THE FRONT OVER THE LOCAL AREA FRIDAY NIGHT. FORCING WILL
BE RATHER LIMITED AS THE TROUGH DYNAMICS WILL REMAIN WELL
NORTH...BUT SUFFICIENT MOISTURE ALONG THE FRONT WILL BE ENOUGH TO
PRODUCE SCATTERED LIGHT SHOWERS. BETTER MOISTURE AND OMEGA OVER
THE SE MAY LEAD TO BETTER DEVELOPMENT LATE FRI NIGHT...BUT WILL
ONLY LEAVE CHANCE POPS ATTM. QPF AMOUNTS WILL BE LIGHT WITH
AMOUNTS GENERALLY LESS THAN TWO TENTHS OF AN INCH. SEVERAL LOCALES
WILL ONLY RECEIVE A FEW HUNDREDTHS OF AN INCH. THE BIGGEST IMPACT
WILL NOT BE THE LIGHT PRECIP...BUT INSTEAD THE COLD AIR THAT WILL
ACCOMPANY THE FRONT. HIGHS WILL LIKELY BE REACHED SAT MORNING
(MID-UPPER 50S)...BEFORE TEMPS FALL DURING THE DAY SATURDAY. BY
6PM SAT...TEMPS ARE FORECAST TO BE IN THE LOW-MID 40S UNDER
RAPIDLY CLEARING SKIES. THE STRONGEST CAA WILL ARRIVE SAT NIGHT AS
NW WINDS INCREASE WITH GUSTS UP TO 25-30 MPH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CDFNT MOVES WELL OFF THE CST SAT NGT...AND ANY PCPN ASSOCIATED W/IT
XPCD TO END AFT MDNGT. DRY...MUCH COLDER AND WINDY WX XPCD SUN. SFC
HI PRES REACHES/BUILDS OVR THE RGN SUN NGT INTO MON. H85 TEMPS FCST
TO FALL TO OR BLO -10 DEGS C SUN NGT...THEN BE SLO TO RECOVER ON
MON. LO PRES TO SLO DEVELOP INVOF SRN PLAINS/WRN GULF STATES ERY
NEXT WEEK...THEN TRACK ENE TO THE MDATLC/SE STATES BY WED. WILL
BRING INCRSG CLDNS/POPS FM THE SW ON TUE. RIGHT NOW...HIGHEST PROB
FOR PCPN IS TUE NGT INTO WED AS SFC LO PRES TRACKS OFF THE CST OF
THE CAROLINAS.
LO TEMPS SAT NGT FM THE M20S W TO L30S AT THE CST. HI TEMPS SUN FM
THE M30S W AND N...TO ARND 40F SE (W/ WIND CHILLS IN THE 20S). LO
TEMPS SUN NGT FM ARND 20F INLAND TO U20S/ARND 30F AT THE CST. HI
TEMPS MON IN THE L/M40S. MODERATION CONTS MON NGT THROUGH TUE. LO
TEMPS MON NGT FM ARND 30F INLAND TO THE U30S NR THE CST...HI TEMPS
TUE FM THE M40S W TO L50S SE. HI TEMPS WED FM THE L40S WELL INLAND
TO L50S AT THE CST.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
STRONG HIGH PRESSURE (NEARLY 1040MB) WILL BE SLOW TO RETREAT TODAY.
MEANWHILE...MOISTURE WILL INCREASE FROM THE S RESULTING IN
WIDESPREAD OVC CIGS. NOT CURRENTLY GOING AS PESSIMISTIC AS THE
NAM/RUC...WHICH SUGGEST THE POTENTIAL FOR IFR/LOW MVFR CIGS LATER
TODAY ALONG WITH -RA/DZ...AS SREF PROBS INDICATE THE HIGHEST
LIKELIHOOD OF IFR OVER THE MOUNTAINS. THE 06Z FORECAST WILL HAVE
PREVAILING CIGS FALLING TO 4K FT AT MOST SITES WITH 2K FT AT
RIC/PHF. A LIGHT NE WIND SHOULD PREVAIL TODAY...BEFORE SHIFTING TO
SE TONIGHT.
HIGH PRESSURE SLOWLY SETTLES SSE THROUGH FRIDAY AS A STRONG COLD
FRONT APPROACHES FROM THE NW. A FEW -SHRA ARE POSSIBLE WITH THE
FRONTAL PASSAGE FRIDAY NIGHT/EARLY SATURDAY. A SECONDARY COLD FRONT
SWINGS THROUGH THE REGION SATURDAY NIGHT FOLLOWED BY A GUSTY NW WIND
SUNDAY. WIND SPEEDS ARE EXPECTED TO REACH 15-20KT...WITH GUSTS TO
25-30KT.
&&
.MARINE...
HIGH PRESSURE BUILDS ACROSS NEW ENGLAND THIS MORNING...BEFORE
SETTLING OFF OF CAPE COD AND GRADUALLY WEAKENING THIS AFTERNOON. THE
SURFACE PRESSURE GRADIENT SLACKENS ACROSS THE AREA ALLOWING THE
CURRENT E/NE WIND TO CONTINUE ITS DIMINISHING TREND. SCAS REMAIN IN
PLACE FOR WAVES/SEAS FOR THE MOUTH OF BAY THROUGH 12Z...OCEAN FROM
CAPE CHARLES TO VA/NC BORDER THROUGH 15Z...AND OCEAN OFF THE
CURRITUCK OUTER BANKS THROUGH 17Z. HIGH PRESSURE CONTINUES TO SINK S
AND WEAKEN OFF THE MID ATLANTIC AND SOUTHEAST COASTS TONIGHT THROUGH
FRIDAY. MEANWHILE...LOW PRESSURE TRACKS THROUGH THE SAINT LAWRENCE
VALLEY ALLOWING THE WIND TO SHIFT TO SW. THIS LOW PRESSURE SYSTEM
PULLS A COLD FRONT ACROSS THE MID ATLANTIC COAST FRIDAY
NIGHT...FOLLOWED BY A SHALLOW CAA SURGE. MINIMAL SCA CONDITIONS ARE
POSSIBLE FOR THE NON-OCEAN ZONES LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING. A SECONDARY COLD FRONT ARRIVES SATURDAY EVENING...FOLLOWED
BY A 24-36HR STRONG CAA NW SURGE. THERE IS A HIGH LIKELIHOOD FOR
HIGH-END SCA CONDITIONS SATURDAY NIGHT THROUGH SUNDAY
EVENING...ALONG WITH THE POTENTIAL FOR GALE FORCE WIND (MAINLY IN
GUSTS). A GRADUAL IMPROVEMENT IS EXPECTED MONDAY INTO TUESDAY. THERE
IS A POTENTIAL FOR A MODERATE TO STRONG NNE WIND BY THE MIDDLE OF
NEXT WEEK AS LOW PRESSURE DEEPENS AND TRACKS OFF THE SOUTHEAST COAST.
&&
.EQUIPMENT...
THE KAKQ RADAR WILL BE DOWN THROUGH AT LEAST TUESDAY, NOVEMBER 26TH
FOR RADOME REPAIRS. SEE THE PUBLIC INFORMATION STATEMENT (PNSAKQ)
FOR ADDITIONAL DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ658.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ656.
&&
$$
SYNOPSIS...BMD/SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...ALB
AVIATION...AJZ
MARINE...AJZ
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
405 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE SLOWLY SLIDES DOWN THE NORTHEAST ATLANTIC COAST
TODAY AND FRIDAY. A STRONG COLD FRONT CROSSES THE REGION ON SATURDAY.
ANOTHER CANADIAN HIGH PRESSURE SYSTEM BUILDS INTO THE AREA EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRONG ~1040MB (+2 STD DEV MSLP) HIGH OVER THE ST LAWRENCE RIVER
VALLEY THIS MORNING CONTINUES TO RIDGE OVER THE LOCAL AREA.
ALOFT...RIDGE HAS LOCATED OVER THE ERN CONUS AS THIS WEEKENDS
STORM SYSTEM TAKES SHAPE OVER SRN CANADA. H85 HIGH HAS LOCATED
OVER ERN NC WITH FLOW AROUND THE WRN PERIPHERY BECOMING S-SW BELOW
A STRONG SUBSIDENCE INVERSION. RETURN FLOW WILL ADVECT MOISTURE
OVER THE CAROLINAS NWD THIS MORNING. ALREADY BEGINNING TO SEE BKN-
OVC MID DECK SPREAD OVER THE LOCAL AREA. SHOWERS HAVE DEVELOPED
OFF THE SE NC COAST ALONG A WEAK COASTAL BOUNDARY EARLY THIS
MORNING. LATEST RUC GUIDANCE SUGGESTS THAT THE BOUNDARY WILL
LINGER THRU THE MORNING BEFORE WEAKENING. MODEST UPPER LEVEL
SUPPORT AND MOISTURE OVERRUNNING THE BOUNDARY WILL RESULT IN
ISOLATED SPRINKLES OVER MAINLY NE NC THRU MID MORNING. NO
MEASURABLE RAINFALL IS ANTICIPATED.
WITH AFOREMENTIONED STRONG HIGH TO THE NORTH AND RIDGING OVER THE
LOCAL AREA (CAD SETUP)...EXPECT CLOUD COVER TO CONTINUE TO THICKEN
THRU THE MORNING INTO THE AFTERNOON. WAA WILL ALSO ENHANCE THE
CLOUD COVER. OTHERWISE...SFC HIGH WILL BEGIN TO BREAK DOWN
TODAY...DRIFTING SWD OFF THE NE COAST BUT REMAINING RIDGED OVER
THE LOCAL AREA. RIDGE AXIS WILL PUSH OFFSHORE LATE TODAY...BUT WLY
FLOW WILL CONTINUE ALOFT. THE RESULTANT WAA WILL BE ENOUGH TO WARM
TEMPS INTO THE LOW-MID 50S INLAND TO UPPER 50S ALONG THE COAST
(SLIGHTLY BELOW NORMAL)...REGARDLESS OF CLOUDY SKIES AND
PERSISTENT ONSHORE FLOW. MODELS REMAIN RATHER AGGRESSIVE WITH LIGHT
RAIN/DRIZZLE TODAY BUT DRY LOW LEVELS WILL PREVENT ANY CHANCE FOR
PRECIP TO MATERIALIZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE WX PATTERN CHANGES ON FRIDAY AS SFC HIGH PRESSURE BREAKS DOWN
AND A STRONG COLD FRONT CROSSES THE OH VALLEY AND HEADS FOR THE
MID ATLANTIC REGION. WARM AIR ADVECTION FROM THE SW WILL CONTINUE
INCREASING TRENDS IN TEMP/DEWPOINT FIELDS DESPITE MOSTLY CLOUDY TO
CLOUDY SKIES. EXPECT HIGHS IN THE LOWER TO MID 60S AREAWIDE (UPPER
60S POSSIBLE COASTAL SE VA/NE NC). A LEE TROUGH DEVELOPS BY FRI
AFTN AND THE PERSISTENT ONSHORE WINDS FROM THE PAST SEVERAL DAY
WILL FINALLY TURN TO THE S-SW THROUGH THE DAY. THE MORE ROBUST
CONVECTIVE-BASED MODELS ARE GENERATING PRECIPITATION DURING THE
AFTN. CURRENT THINKING IS THAT THESE PARTICULAR MODELS ARE
OVERDONE. WEST WINDS ALOFT AND DEVELOPING SW SFC WINDS WILL ACT TO
DOWNSLOPE THE AREA AND KEEP CONDITIONS DRY...WHICH IS MORE IN LINE
WITH THE MORE BROAD-BRUSHED MODEL SOLUTIONS THAT TEND TO BE CLOSER
TO REALITY WHEN IT COMES TO THE DAY 3 FORECAST. WILL NEED TO SEE
HOW 12Z MODELS TREND TOMORROW REGARDING POTENTIAL PRECIP FRI AFTN.
A STRONG COLD FRONT WILL PUSH ACROSS THE MID ATLANTIC REGION LATE
FRI NIGHT INTO SATURDAY MORNING...WHICH WILL PROVIDE THE BEST SHOT
FOR PRECIPITATION WITHIN THE SHORT TERM FORECAST. OVERALL QPF
AMOUNTS ARE LESS THAN 0.25 INCHES AND WILL FALL AS ALL RAIN. THE
COLDER AIR MOVING IN BEHIND THE FRONT WILL NOT ARRIVE UNTIL AFTER
THE PRECIP HAS MOVED OFFSHORE. WILL NEED TO MONITOR ANY CHANGES
CLOSELY SINCE TIMING DIFFERENCES COULD INFLUENCE P-TYPE (MAINLY IF
THE FRONT IS SLOWER TO PUSH THROUGH THE AREA). THIS SYSTEM WILL
PRODUCE A TIGHT SFC PRESSURE GRADIENT AND A TIGHT TEMPERATURE
GRADIENT AS ANOTHER COLD ARCTIC AIRMASS MOVES IN BEHIND THE
DEPARTING FRONT. SW WINDS WILL SHIFT TO THE W JUST AHEAD OF THE
FRONTAL PASSAGE AND TEMPS WILL STAY ELEVATED OVERNIGHT...WITH LOWS
IN THE UPPER 40S NW TO LOWER 50S SE. HIGH TEMPS ON SAT SHOULD PEAK
IN THE MID 50S TO LOWER 60S SE BY LATE MORNING...THEN FALL THROUGH
THE DAY AS BREEZY WINDS TURN TO THE NW AND THE ARCTIC AIRMASS
BEGINS TO INFILTRATE THE REGION FROM THE NW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CDFNT MOVES WELL OFF THE CST SAT NGT...AND ANY PCPN ASSOCIATED W/IT
XPCD TO END AFT MDNGT. DRY...MUCH COLDER AND WINDY WX XPCD SUN. SFC
HI PRES REACHES/BUILDS OVR THE RGN SUN NGT INTO MON. H85 TEMPS FCST
TO FALL TO OR BLO -10 DEGS C SUN NGT...THEN BE SLO TO RECOVER ON
MON. LO PRES TO SLO DEVELOP INVOF SRN PLAINS/WRN GULF STATES ERY
NEXT WEEK...THEN TRACK ENE TO THE MDATLC/SE STATES BY WED. WILL
BRING INCRSG CLDNS/POPS FM THE SW ON TUE. RIGHT NOW...HIGHEST PROB
FOR PCPN IS TUE NGT INTO WED AS SFC LO PRES TRACKS OFF THE CST OF
THE CAROLINAS.
LO TEMPS SAT NGT FM THE M20S W TO L30S AT THE CST. HI TEMPS SUN FM
THE M30S W AND N...TO ARND 40F SE (W/ WIND CHILLS IN THE 20S). LO
TEMPS SUN NGT FM ARND 20F INLAND TO U20S/ARND 30F AT THE CST. HI
TEMPS MON IN THE L/M40S. MODERATION CONTS MON NGT THROUGH TUE. LO
TEMPS MON NGT FM ARND 30F INLAND TO THE U30S NR THE CST...HI TEMPS
TUE FM THE M40S W TO L50S SE. HI TEMPS WED FM THE L40S WELL INLAND
TO L50S AT THE CST.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
STRONG HIGH PRESSURE (NEARLY 1040MB) WILL BE SLOW TO RETREAT TODAY.
MEANWHILE...MOISTURE WILL INCREASE FROM THE S RESULTING IN
WIDESPREAD OVC CIGS. NOT CURRENTLY GOING AS PESSIMISTIC AS THE
NAM/RUC...WHICH SUGGEST THE POTENTIAL FOR IFR/LOW MVFR CIGS LATER
TODAY ALONG WITH -RA/DZ...AS SREF PROBS INDICATE THE HIGHEST
LIKELIHOOD OF IFR OVER THE MOUNTAINS. THE 06Z FORECAST WILL HAVE
PREVAILING CIGS FALLING TO 4K FT AT MOST SITES WITH 2K FT AT
RIC/PHF. A LIGHT NE WIND SHOULD PREVAIL TODAY...BEFORE SHIFTING TO
SE TONIGHT.
HIGH PRESSURE SLOWLY SETTLES SSE THROUGH FRIDAY AS A STRONG COLD
FRONT APPROACHES FROM THE NW. A FEW -SHRA ARE POSSIBLE WITH THE
FRONTAL PASSAGE FRIDAY NIGHT/EARLY SATURDAY. A SECONDARY COLD FRONT
SWINGS THROUGH THE REGION SATURDAY NIGHT FOLLOWED BY A GUSTY NW WIND
SUNDAY. WIND SPEEDS ARE EXPECTED TO REACH 15-20KT...WITH GUSTS TO
25-30KT.
&&
.MARINE...
HIGH PRESSURE BUILDS ACROSS NEW ENGLAND THIS MORNING...BEFORE
SETTLING OFF OF CAPE COD AND GRADUALLY WEAKENING THIS AFTERNOON. THE
SURFACE PRESSURE GRADIENT SLACKENS ACROSS THE AREA ALLOWING THE
CURRENT E/NE WIND TO CONTINUE ITS DIMINISHING TREND. SCAS REMAIN IN
PLACE FOR WAVES/SEAS FOR THE MOUTH OF BAY THROUGH 12Z...OCEAN FROM
CAPE CHARLES TO VA/NC BORDER THROUGH 15Z...AND OCEAN OFF THE
CURRITUCK OUTER BANKS THROUGH 17Z. HIGH PRESSURE CONTINUES TO SINK S
AND WEAKEN OFF THE MID ATLANTIC AND SOUTHEAST COASTS TONIGHT THROUGH
FRIDAY. MEANWHILE...LOW PRESSURE TRACKS THROUGH THE SAINT LAWRENCE
VALLEY ALLOWING THE WIND TO SHIFT TO SW. THIS LOW PRESSURE SYSTEM
PULLS A COLD FRONT ACROSS THE MID ATLANTIC COAST FRIDAY
NIGHT...FOLLOWED BY A SHALLOW CAA SURGE. MINIMAL SCA CONDITIONS ARE
POSSIBLE FOR THE NON-OCEAN ZONES LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING. A SECONDARY COLD FRONT ARRIVES SATURDAY EVENING...FOLLOWED
BY A 24-36HR STRONG CAA NW SURGE. THERE IS A HIGH LIKELIHOOD FOR
HIGH-END SCA CONDITIONS SATURDAY NIGHT THROUGH SUNDAY
EVENING...ALONG WITH THE POTENTIAL FOR GALE FORCE WIND (MAINLY IN
GUSTS). A GRADUAL IMPROVEMENT IS EXPECTED MONDAY INTO TUESDAY. THERE
IS A POTENTIAL FOR A MODERATE TO STRONG NNE WIND BY THE MIDDLE OF
NEXT WEEK AS LOW PRESSURE DEEPENS AND TRACKS OFF THE SOUTHEAST COAST.
&&
.EQUIPMENT...
THE KAKQ RADAR WILL BE DOWN THROUGH AT LEAST TUESDAY, NOVEMBER 26TH
FOR RADOME REPAIRS. SEE THE PUBLIC INFORMATION STATEMENT (PNSAKQ)
FOR ADDITIONAL DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ658.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR ANZ656.
&&
$$
SYNOPSIS...BMD
NEAR TERM...SAM
SHORT TERM...BMD
LONG TERM...ALB
AVIATION...AJZ
MARINE...AJZ
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1155 PM EST WED NOV 20 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
THE OVERALL WEATHER PATTERN WILL REMAIN QUITE MESSY...MAKING THE
OVERALL FORECAST TRICKY OVER THE NEXT DAY. A LIGHT WET SNOW IS
EXPECTED ACROSS THE INTERIOR WEST THIS EVENING BEFORE A COLD FRONT
PUSHES INTO THE WESTERN CWA THURSDAY AFTERNOON.
LATE THIS AFTERNOON AND TONIGHT...MID-LEVEL SW FLOW AHEAD OF DEEP
TROUGHING DEVELOPING ACROSS CENTRAL CANADA WILL CONTINUE THROUGH
THURSDAY. AN ASSOCIATED SFC TROUGH ORIENTED ACROSS THE UPPER MS
VALLEY BETWEEN LOW PRESSURE OVER HUDSON BAY AND DEVELOPING LOW
PRESSURE ACROSS THE SOUTHERN HIGH PLAINS WILL SLOWLY PUSH EAST. A
WELL-DEFINED MID-LEVEL SHORTWAVE TROUGH CURRENTLY CENTERED NEAR
SIOUX FALLS WILL CONTINUE ITS NORTHEASTWARD PROGRESSION THIS EVENING
AND BE THE MAIN PLAYER IN PRECIPITATION.
MANY CONVOLUTED FORCING MECHANISMS WILL BE AT WORK THIS EVENING. A
COMPLICATED LOW-LEVEL FGEN PATTERN SLOPING TO THE SE WITH HEIGHT AND
A WEAK UPPER-LEVEL JET STREAK MERGING WITH THE POLAR JET WILL IMPOSE
CONFLICTING OMEGA FIELDS ON EACH OTHER. THIS WEAK UPPER JET STREAK
APPEARS TO BE SOME CONVECTIVE FEEDBACK TIED TO A CLUSTER OF
PERSISTENT STORMS OVER IA AND MO. MEANWHILE...WEAK ISENTROPIC ASCENT
ON THE 290-295K SFCS WILL ASSIST SOME MID-LEVEL PRECIP DEVELOPMENT
THIS EVENING. OVERALL...PRECIP LOOKS TO BE CONTROLLED BY THE
ISENTROPIC ASCENT AND Q-VECTOR CONV WITH THE MID-LEVEL WAVE.
A BROKEN SHIELD OF RAIN AND SNOW SHOWERS HAS DEVELOPED ACROSS
WESTERN WI OVER THE PAST SEVERAL HOURS. THIS HAS EASED SOME CONCERNS
THAT THE MIXED OMEGA FIELD WOULD SUPPRESS PRECIP. THE RAP HAS
MAINTAINED A DECENT HANDLE ON THE PRECIP EVOLUTION...SO HAVE
FOLLOWED IT FOR THE OVERALL PRECIP PATTERN WHILE EMPLOYING THE NAM
FOR THE SYNOPTIC EVOLUTION. PRECIP HAS JUST STARTED TO SPREAD INTO
THE INTERIOR WEST NEAR WI AND WILL CONTINUE NORTHWARD INTO THE
EVENING. THERE IS GOOD AGREEMENT THAT THE GREATEST COVERAGE WILL BE
MID TO LATE EVENING ACROSS MUCH OF THE WEST HALF OF THE CWA BEFORE
PRECIP SPREADS EASTWARD OVERNIGHT WITH THE WAVE.
PTYPE LOOKS TO BE MOSTLY WET SNOW FOR ALL BUT THE NEAR LAKE SUPERIOR
SHORELINE AS WETBULB ZERO LEVELS WILL BE WELL BELOW 1KFT. A SUB
700MB DRY LAYER MAY INHIBIT PRECIP INITIALLY...BUT GIVEN CURRENT
RADAR RETURNS IN WI...PRECIP RATES SHOULD BE HIGH ENOUGH TO OVERCOME
THE DRY AIR IN A HOUR OR SO. SNOW RATIOS SHOULD BE QUITE
LOW...GENERALLY 8-10:1 AS MOST LIFT WILL BE W/IN TEMPS HIGHER THAN
THE DGZ. SOME AGGREGATION COULD BE POSSIBLE THROUGH A DEEP
ISOTHERMAL LAYER BETWEEN -3 AND -5C...SO LARGER WET FLAKES ARE
POSSIBLE. TOTAL SNOWFALL THROUGH TONIGHT IS FORECAST TO BE 0.5-1.5
INCHES FOR THE INTERIOR WEST HALF...HIGHEST FROM IRON RIVER TO
CHAMPION. WOULD NOT BE SURPRISED IF SOME LOCATIONS TOP 2 INCHES
GIVEN THE HEAVIER SHOWER ACTIVITY EXPECTED. SHORELINE LOCATIONS WILL
SEE MINIMAL ACCUMULATION AS A RESULT OF LOWER ELEVATION AND
DOWNSLOPING WITH A GENERAL SOUTH WIND.
OVERALL PRECIP COVERAGE WILL DIMINISH SLOWLY AS THE SHIELD
PROGRESSES EASTWARD. HOWEVER...CONTINUED SOUTH TO SSW FLOW OFF LAKE
MI SHOULD YIELD A LAKE-ENHANCED BAND OF RAIN AND SNOW SHOWERS
ACROSS EASTERN DELTA INTO SCHOOLCRAFT COUNTIES. MEANWHILE...MINIMAL
FZDZ WILL BE POSSIBLE ACROSS THE FAR WEST LATE TONIGHT AS SOME
MID-LEVEL DRYING BEHIND THE SHORTWAVE LIMITS LIFT TO THE BARELY
SUB-FREEZING LOW-LEVELS.
THURSDAY...AN OVERALL LULL IN PRECIP IS EXPECTED THROUGH THURSDAY
MORNING BEHIND THE MID-LEVEL WAVE...BUT THE SFC TROUGH WILL BEGIN TO
TRACK ACROSS THE CWA DURING THE AFTERNOON ACROSS THE WEST. HIGH
TEMPS WILL BE FAIRLY EARLY IN THE DAY FOR THE WEST HALF...WITH
FALLING TEMPS THROUGHOUT THE AFTERNOON. HIGHER MOISTURE WITH THE
FRONT AND DROPPING TEMPS WILL INCREASE SNOW SHOWER COVERAGE
WEST...ESPECIALLY FOR THE HIGHER TERRAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
SPLIT FLOW PATTERN PERSISTS THROUGH LATE THIS WEEK THEN FLOW PATTERN
BECOMES PHASED THIS WEEKEND INTO INTO FIRST PART OF NEXT WEEK WHICH
ALLOWS COLDEST AIR OF THE SEASON TO ARRIVE. COUPLE OF SHORTWAVES AND
SMALLER JET STREAKS LIFT ACROSS THURSDAY NIGHT INTO FRIDAY. BEST
CHANCE OF SYNOPTIC PRECIPITATION OCCURS THURSDAY NIGHT...ESPECIALLY
OVER THE SOUTH AND EAST. THOUGH THERE COULD BE SOME MIXED RAIN AND
SNOW EARLY THURSDAY EVENING IN THE EAST...SOUNDINGS AND THICKNESSES
BEYOND THAT TIME INDICATE COLD AIR WILL STAY IN PLACE LEADING TO SNOW
AS ONLY PTYPE THROUGH THE THANKSGIVING HOLIDAY.
MAY SEE ENHANCEMENT TO SNOW OVER THE WEST AND NORTH THURSDAY NIGHT
AS TEMPS AT INVERSION TOP OR H85 FALL TO -8C TO -10C GIVING A DELTA
T TO AROUND 13C. MORE SIGNIFICANT CONTRIBUTION FROM THE LAKE
ENHANCEMENT MAY BE OVER HIGHER TERRAIN OF NCNTRL AS LARGER SCALE
FORCING FOR SNOW PERSISTS INTO DAYBREAK ON FRIDAY. A FEW INCHES OF
SNOW MAY OCCUR OVER THURSDAY NIGHT FOR HIGHER TERRAIN OF MARQUETTE
COUNTY AND FOR FAVORED INLAND SNOWBELTS OF WESTERN ALGER COUNTY.
ELSEWHERE SNOW AMOUNTS OF AN INCH OR TWO ARE POSSIBLE.
ARCTIC FRONT WILL BE BLASTING SOUTH ACROSS MANITOBA AND NORTHERN
ONTARIO ON FRIDAY BUT WILL NOT ARRIVE OVER UPR LAKES UNTIL FRIDAY
EVENING. SO...FRIDAY MAY END UP A FAIRLY QUIET BTWN SYSTEMS DAY AS
CWA WILL BE IN WAKE OF THURSDAY NIGHT WAVE AND STILL AHEAD OF ARCTIC
FRONT/STRONG COLD AIR ADVECTION/LK EFFECT SNOWS FOR LATER FRIDAY
NIGHT INTO THE WEEKEND. PARTIAL CLEARING MAY OCCUR BUT WITH LIMITED
WARM AIR ADVECTION AHEAD OF THE FRONT...TEMPS WILL SILL END UP IN
THE 20S. WINDS WILL BE ON THE LIGHTER SIDE COMPARED TO THE WINDY
CONDITIONS COMING FOR THE WEEKEND.
ARCTIC FRONT SWEEPS THROUGH ON FRIDAY NIGHT. TEMPS STARTING OUT THE
EVENING IN THE UPR 20S WILL BE SOLIDLY IN THE TEENS OVER THE WEST BY
DAYBREAK ON SATURDAY AND GOING NOWHERE FAST. TEMPS WILL STAY STEADY
OR FALL SLIGHTLY ON SATURDAY AS PLUNGE OF COLD AIR AT H85 AND H7
DRIVES ACROSS THE GREAT LAKES REGION. EXPECT LK EFFECT SNOWS TO RAMP
UP SIGNIFICANTLY. INTITAL BURST OF SNOW OCCURS FRIDAY EVENING OVER
THE KEWEENAW WITH SUFFICIENT OVERWATER INSTABILITY COMBINING WITH
LOW-LEVEL CONVERGENCE ALONG FRONT. SOUNDINGS INDICATE FAVORABLE
MOISTURE AND LOCATION OF DGZ INTERSECTING PROJECTED UVM. SLR/S
SHOULD INCREASE TO MORE OF A FLUFFY 15-20:1 WITH STRONG NW WINDS IN
BLYR ONLY THING PROHIBITING SLR/S WELL OVER 20:1. ONCE BURST OF
HEAVIER SNOW SLIDES ACROSS CWA WITH THE ARCTIC FRONT...EXPECT
PERIOD OF HEAVY NNW FLOW LK EFFECT THROUGH THE DAY. NNW WINDS IN
BLYR AND A STILL OPEN LK NIPEGON COULD LEAD TO HEAVIEST SNOW
SHOWERS SETTING UP BTWN MQT AND MUNISING. SNOW TOTALS LATER
FRIDAY NIGHT THROUGH SATURDAY WILL BE AT LEAST ADVY ALONG MUCH OF
LK SUPERIOR WITH SOME AREAS SEEING WARNING AMOUNTS OF 10 INCHES IN
12 HOURS. STRONG WINDS WITH THE FLUFFIER SNOW WILL RESULT IN AREAS
OF BLOWING SNOW/REDUCED VSBY. PRETTY CONFIDENT HEADLINES FOR THIS
EVENT WILL BE COMING IN THE NEXT COUPLE DAYS. FOR NOW...WILL KEEP
GRAPHICAL MENTION IN THE EHWO AND A MENTION IN HAZARDOUS WEATHER
OUTLOOK.
DEPARTING DEEPER MOISTURE AND LOWERING INVERSIONS/INCREASING
ANTICYCLONIC FLOW WITH ARRIVAL OF SFC RIDGE WILL PUT A CRIMP IN LK
EFFECT BY SATURDAY NIGHT. STILL MAY SEE ADVY AMOUNTS OVER THE EAST
THOUGH AS OVERWATER INSTABILITY REMAINS MORE THAN SUFFICIENT AND
THERE WILL LIKELY BE SOME UPTICK OF LOW-LEVEL CONVERGENCE AS WINDS
BACK MORE WESTERLY OVR LAND WITH THE ARRIVAL OF THE SFC RIDGE TOWARD
WESTERN UPR MICHIGAN. TRANSITION ON SUNDAY AS SFC RIDGE CROSSES.
COULD BE TRICKY SINCE COLD AIR LINGERS AND WINDS BECOME FAVORABLE
FOR LK EFFECT OFF LK MICHIGAN. INITIALLY WINDS HAVE ENOUGH SOUTHERLY
COMPONENT TO INCLUDE HIGHER POPS OVER MUCH OF SCHOOLCRAFT AND LUCE
COUNTIES...THEN EVENTUALLY ON SUNDAY NIGHT THE WINDS HAVE ENOUGH OF
A WESTERLY COMPONENT TO PUSH MOST OF MORE SIGNIFICANT LK EFFECT
FARTHER TO THE EAST. HOWEVER...CLIPPER LOW PRESSURE SYSTEM DROPPING
TO NORTH OF LK SUPERIOR WILL SPREAD ADDITIONAL SNOW ACROSS NORTHERN
AND EASTERN UPR MICHIGAN.
ANOTHER BOUT OF COLD AIR AND LK EFFECT LIKELY IN WAKE OF THAT
CLIPPER TUESDAY AND WEDNESDAY. ONCE AGAIN AREAS FAVORED BY NNW
FLOW OVER CNTRL AND EASTERN CWA WILL SEE THE BEST SHOT AT HEAVIER
SNOW. PLENTY OF TIME TO ASSESS THIS POTENTIAL ONCE WE GET PAST THE
WEEKEND LK EFFECT SNOWS. PEEK AHEAD TO THANKSGIVING SHOWS THE COLD
AIR PERSISTS WHILE LINGERING LK EFFECT RUNS ITS COURSE. SO...AT
LEAST AT THIS POINT...NO LARGE SCALE LOW PRESSURE SYSTEM/WIDESPREAD
SNOW EXPECTED FOR THE THANKSGIVING TIME FRAME. PROBABLY GOES WITHOUT
SAYING...BUT OBVIOUSLY THERE IS PLENTY OF TIME FOR THIS TO CHANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM EST WED NOV 20 2013
LIGHT SNOW WILL MOVE OUT THIS MORNING WITH CONDITIONS SLOWLY
IMPROVING. IFR CIGS SHOULD DEVELOP AT IWD AND SAW OVERNIGHT AS WINDS
BECOME MORE SSW AND LOW-LEVEL MOISTURE INCREASES BEHIND THE PRECIP.
ALL SITES SHOULD SEE SOME CIG IMPROVEMENT THURSDAY MORNING WITH SOME
LOW-LEVEL DRYING AND MINIMAL LIFT. THE EXCEPTION WILL BE CMX...WHERE
AN APPROACHING COLD FRONT WILL BRING NW WINDS AND INCREASINGLY
UPSLOPE FLOW. LAKE EFFECT SNOW SHOWERS AND MVFR CONDITIONS EXPECTED
AT ALL TAF SITES THU AFTERNOON WHICH WILL REMAIN THROUGH THU EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST WED NOV 20 2013
SOUTHERLY WINDS OF UP TO 30 KNOTS FOR EASTERN LAKE SUPERIOR LATE
THIS AFTERNOON WILL DIMINISH TO LESS THAN 20 KNOTS BY THURSDAY
MORNING AS A COLD FRONT NEARS WESTERN LAKE SUPERIOR. THE COLD FRONT
IS EXPECTED TO CROSS LAKE SUPERIOR BEGINNING FAR WEST MID-THURSDAY
MORNING...AND REACHING THE FAR EAST THURSDAY EVENING. WINDS WILL
QUICKLY VEER TO THE NW AROUND 30 KNOTS FOR MUCH OF LAKE SUPERIOR
BEHIND THE FRONT. EXPECT THESE WINDS TO CONTINUE THROUGH THURSDAY
EVENING BEFORE DIMINISHING ON FRIDAY.
STRONG HIGH PRESSURE BUILDING ACROSS CENTRAL CANADA WILL BEGIN TO
IMPINGE ON LOW PRESSURE DEVELOPING OVER THE LOWER GREAT LAKES FRIDAY
AFTERNOON AND EVENING. WEST WINDS OF 20-30 KNOTS ACROSS WESTERN LAKE
SUPERIOR FRIDAY EVENING WILL BECOME NW GALES TO 35 KNOTS WEST TO NW
GALES TO 45 KNOTS EAST SATURDAY MORNING. THE WINDS WILL GRADUALLY
DIMINISH TO UNDER 20 KNOTS BY SUNDAY MORNING. WITH ARCTIC AIR MOVING
OVER THE LAKE...THERE IS A POTENTIAL FOR WIDESPREAD FREEZING SPRAY
SATURDAY AND SATURDAY NIGHT. THEN AN APPROACHING LOW PRESSURE FROM
CANADA WILL BACK WINDS SW TO 20-30 KNOTS BY MONDAY MORNING. ANOTHER
COLD FRONT WILL FOLLOW MONDAY AFTERNOON WITH 20-30 KNOTS NW WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY NIGHT
FOR LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KLUBER
LONG TERM...JLA
AVIATION...07
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
232 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WITH RAIN SHOWERS WILL MOVE THROUGH THE
REGION THURSDAY NIGHT AND FRIDAY. A STRONG COLD FRONT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT, WHICH WILL USHER IN MUCH COLDER
AIR STARTING SUNDAY. THIS COLD AIR COULD GENERATE SIGNIFICANT
LAKE EFFECT SNOWS IN THE LAKE EFFECT SNOW BELTS OF NORTH CENTRAL
NEW YORK.
&&
.NEAR TERM /THROUGH TODAY/...
745 PM UPDATE... ONLY MINOR TWEAKS WERE MADE TO THE GRIDS EARLY
THIS EVE...WITH OUR EXISTING FCST IN GOOD SHAPE.
SAT IMAGERY/SFC OBS ARE SHOWING THIN HIGH CLDNS CROSSING CNY/NE PA
THIS EVE. GIVEN SAT TRENDS UPSTREAM...WE THINK WE`LL CONTINUE TO
SEE SOME HIGH CLOUD COVER OVERNIGHT...BUT GIVEN ITS FAIRLY
TRANSPARENT NATURE...PTLY CLDY SEEMS LIKE A GOOD SKY COVER
DESCRIPTOR. THERE WAS SOME THINKING EARLIER TDY THAT A MARINE LYR
CLOUD DECK COULD SNEAK UP INTO OUR SERN ZNS BY...OR JUST AFTER
09Z THU. ALTHOUGH THERE IS SOME PATCHY SC ATTM ACRS SRN VA...WE
THINK THAT LWR CLDS WILL NOT MAKE IT TO NE PA BY DAYBREAK FOR SVRL
REASONS...LACK OF CLOUD DVLPMT/ONSHORE FLOW ATTM OVER MOST OF THE
DELMARVA RGN OR NJ...WEAK LOW-LVL FLOW...AND A VERY DRY RESIDENT
AMS IN THE BLYR (SFC DEW PTS NEAR 10F OVER MUCH OF ERN PA ATTM).
WE STILL FEEL CONFIDENT SOME OF OUR NORMALLY COLDER SHELTERED VLYS
WILL DROP INTO THE TEENS BY DAYBREAK. AS A RESULT...WE BASICALLY
LEFT OUR LOW TEMP FCST ALONE...AND JUST MASSAGED SOME NEAR-TERM
TEMPS AND DEW PTS THIS EVE.
PREV DISC... HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO
THIS EVENING AS THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT
ONLY SOME PATCHY CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS
WHICH WILL BE MOVG OVHD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD
EARLIER IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN
SPREADING EWRD AS THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE
MIN/S OCCURRING IN THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI
AM WHEN THE BULK OF THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND
IT. THEN THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT
WAVE APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE
TRUE ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR
SAT...IT LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS
AND FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL
BE A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
230 AM UPDATE...
SEE NO REASON TO MAKE TOO MANY CHGS TO EXTNDD FCST. COLD TEMPS
EXPECTED FOR SUNDAY AS THICKNESS VALUES DROP BLO 500DM FOR A TIME
DRG THE AFTN. H8 TEMPS EXPECTED TO RANGE BTWN -15C AND -20C,
YIELDING HIGHS IN THE 20S. THIS WL BE SOME 20F DEGREES BLO NORMAL
FOR THE DAY. AN UPR LOW WL BEGIN TO EJECT OUT OF THE PLAINS ON
TUESDAY WITH MED RANGE MODELS INDICATING A SFC LOW WL DVLP ACRS
THE NRN GOM BY 12Z TUESDAY. HWVR, WHERE IT GOES FM THERE IS UP IN
THE AIR AT THIS POINT, WITH 00Z EC BRINGING IT INTO MID-ATLANTIC
STATES BY MID-WEEK AND GFS KEEPING IT CONFINED TO SE COAST. HV
GONE WITH A VAGUE 30 POPS FOR TUE/WED DUE TO SIGNIFICANT AMNT OF
UNCERTAINTY.
PREVIOUS DISCUSSION...
EXTENDED FORECAST BEGINS WITH A VERY COLD AIRMASS ACROSS THE
NORTHEAST AS A DEEP UPPER LEVEL TROF SWINGS THROUGH THE AREA. BOTH
THE GFS/ECMWF CONTINUE TO ADVERTISE T85 AROUND -16C/-18C FOR 18Z
SUN. THEY BOTH HAVE BEEN CONSISTENT WITH THIS COLD AIRMASS FOR
SEVERAL RUNS NOW INDICATING A HIGH LIKELY HOOD OF OCCURRENCE.
INITIALLY THE LOW LEVEL FLOW SATURDAY NIGHT LOOKS AROUND 290
DEGREES THEN SHIFTS MORE NORTHWEST AFTER 06Z AS A SECONDARY TROF
PASSES. ON SUNDAY, THE LOW LEVEL FLOW WILL BACK AS H85 RIDGE MOVES
THROUGH THE AREA. FOR SATURDAY NIGHT THROUGH SUNDAY WILL CONTINUE
TO ADVERTISE LIKELY POPS FOR LES PRIMARILY SOUTHEAST OF LAKE
ONTARIO. SNOW ACCUMS THROUGH THE PERIOD WILL LIKELY REACH SEVERAL
INCHES WITH A LAKE SNOW ADVISORY MOST LIKELY NEEDED SATURDAY NIGHT
INTO SUNDAY AS THE EVENT APPROACHES. A SHORT FETCH AND LIMITED
SYNOPTIC MOISTURE MAY LIMIT ACCUMS BUT THE AIRMASS IS VERY COLD
FOR THIS TIME OF THE YEAR.
MONDAY NIGHT INTO WEDNESDAY, A NORTHERN STREAM SYSTEM WILL MOVE
THROUGH THE UPPER GREAT LAKES AND ACROSS EASTERN CANADA. WILL
MENTION CHC/SLIGHT CHC POPS FOR SNOW SHOWERS. THE MEDIUM RANGE
MODELS HAVE HINTED AT A NORTHERN/SOUTHERN STREAM PHASING TUE INTO
WED WITH THE DEVELOPMENT OF A STRONG COAST LOW WHICH COULD IMPACT
THE FORECAST AREA. THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF
NOW SHOW THE SYSTEM REMAINING PRIMARILY EAST/SOUTH OF THE AREA.
IT`S STILL EARLY, SOMETHING TO WATCH.
TEMPS THROUGH THE PERIOD WILL BE AROUND 10-15 DEGREES BELOW
NORMAL.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
HIGH PRESSURE WILL KEEP TERMINALS VFR FOR THE NEXT 24 HOURS. SCT-
BKN 25KFT CIGS EXPECTED THROUGH 13Z-17Z BEFORE MID-DECK BEGINS TO MOVE
IN. AFTER 21Z ACROSS WESTERN TERMINALS OVC050 EXPECTED BY 21Z AND
SLOWLY PROGRESSING EAST FROM THERE. OVERALL NO RESTRICTIONS
EXPECTED THROUGH 06Z FRIDAY THOUGH A STRAY SHOWER WILL BE POSSIBLE
TOWARD THE END OF TAF VALID TIME.
EAST TO SOUTHEAST WINDS AROUND 5 KTS OVERNIGHT BECOMING SOUTH
AROUND 8 KTS STARTING 15Z.
OUTLOOK...
LATE THURSDAY NIGHT INTO FRIDAY...MVFR AND POSSIBLY IFR
RESTRICTIONS LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT
SHSN...ESPECIALLY CENTRAL NY TERMINALS.
SUNDAY NIGHT AND MONDAY MORNING...VFR.
MONDAY AFTN...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS
TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/DJN/TAC
NEAR TERM...CMG/DJN/MLJ
SHORT TERM...DJN
LONG TERM...PVN/RRM
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1231 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WITH RAIN SHOWERS WILL MOVE THROUGH THE
REGION THURSDAY NIGHT AND FRIDAY. A STRONG COLD FRONT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT, WHICH WILL USHER IN MUCH COLDER
AIR STARTING SUNDAY. THIS COLD AIR COULD GENERATE SIGNIFICANT
LAKE EFFECT SNOWS IN THE LAKE EFFECT SNOW BELTS OF NORTH CENTRAL
NEW YORK.
&&
.NEAR TERM /THROUGH TODAY/...
745 PM UPDATE... ONLY MINOR TWEAKS WERE MADE TO THE GRIDS EARLY
THIS EVE...WITH OUR EXISTING FCST IN GOOD SHAPE.
SAT IMAGERY/SFC OBS ARE SHOWING THIN HIGH CLDNS CROSSING CNY/NE PA
THIS EVE. GIVEN SAT TRENDS UPSTREAM...WE THINK WE`LL CONTINUE TO
SEE SOME HIGH CLOUD COVER OVERNIGHT...BUT GIVEN ITS FAIRLY
TRANSPARENT NATURE...PTLY CLDY SEEMS LIKE A GOOD SKY COVER
DESCRIPTOR. THERE WAS SOME THINKING EARLIER TDY THAT A MARINE LYR
CLOUD DECK COULD SNEAK UP INTO OUR SERN ZNS BY...OR JUST AFTER
09Z THU. ALTHOUGH THERE IS SOME PATCHY SC ATTM ACRS SRN VA...WE
THINK THAT LWR CLDS WILL NOT MAKE IT TO NE PA BY DAYBREAK FOR SVRL
REASONS...LACK OF CLOUD DVLPMT/ONSHORE FLOW ATTM OVER MOST OF THE
DELMARVA RGN OR NJ...WEAK LOW-LVL FLOW...AND A VERY DRY RESIDENT
AMS IN THE BLYR (SFC DEW PTS NEAR 10F OVER MUCH OF ERN PA ATTM).
WE STILL FEEL CONFIDENT SOME OF OUR NORMALLY COLDER SHELTERED VLYS
WILL DROP INTO THE TEENS BY DAYBREAK. AS A RESULT...WE BASICALLY
LEFT OUR LOW TEMP FCST ALONE...AND JUST MASSAGED SOME NEAR-TERM
TEMPS AND DEW PTS THIS EVE.
PREV DISC... HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO
THIS EVENING AS THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT
ONLY SOME PATCHY CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS
WHICH WILL BE MOVG OVHD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD
EARLIER IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN
SPREADING EWRD AS THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE
MIN/S OCCURRING IN THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI
AM WHEN THE BULK OF THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND
IT. THEN THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT
WAVE APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE
TRUE ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR
SAT...IT LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS
AND FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL
BE A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EXTENDED FORECAST BEGINS WITH A VERY COLD AIRMASS ACROSS THE
NORTHEAST AS A DEEP UPPER LEVEL TROF SWINGS THROUGH THE AREA. BOTH
THE GFS/ECMWF CONTINUE TO ADVERTISE T85 AROUND -16C/-18C FOR 18Z
SUN. THEY BOTH HAVE BEEN CONSISTENT WITH THIS COLD AIRMASS FOR
SEVERAL RUNS NOW INDICATING A HIGH LIKELY HOOD OF OCCURRENCE.
INITIALLY THE LOW LEVEL FLOW SATURDAY NIGHT LOOKS AROUND 290
DEGREES THEN SHIFTS MORE NORTHWEST AFTER 06Z AS A SECONDARY TROF
PASSES. ON SUNDAY, THE LOW LEVEL FLOW WILL BACK AS H85 RIDGE MOVES
THROUGH THE AREA. FOR SATURDAY NIGHT THROUGH SUNDAY WILL CONTINUE
TO ADVERTISE LIKELY POPS FOR LES PRIMARILY SOUTHEAST OF LAKE
ONTARIO. SNOW ACCUMS THROUGH THE PERIOD WILL LIKELY REACH SEVERAL
INCHES WITH A LAKE SNOW ADVISORY MOST LIKELY NEEDED SATURDAY NIGHT
INTO SUNDAY AS THE EVENT APPROACHES. A SHORT FETCH AND LIMITED
SYNOPTIC MOISTURE MAY LIMIT ACCUMS BUT THE AIRMASS IS VERY COLD
FOR THIS TIME OF THE YEAR.
MONDAY NIGHT INTO WEDNESDAY, A NORTHERN STREAM SYSTEM WILL MOVE
THROUGH THE UPPER GREAT LAKES AND ACROSS EASTERN CANADA. WILL
MENTION CHC/SLIGHT CHC POPS FOR SNOW SHOWERS. THE MEDIUM RANGE
MODELS HAVE HINTED AT A NORTHERN/SOUTHERN STREAM PHASING TUE INTO
WED WITH THE DEVELOPMENT OF A STRONG COAST LOW WHICH COULD IMPACT
THE FORECAST AREA. THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF
NOW SHOW THE SYSTEM REMAINING PRIMARILY EAST/SOUTH OF THE AREA.
IT`S STILL EARLY, SOMETHING TO WATCH.
TEMPS THROUGH THE PERIOD WILL BE AROUND 10-15 DEGREES BELOW
NORMAL.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
HIGH PRESSURE WILL KEEP TERMINALS VFR FOR THE NEXT 24 HOURS. SCT-
BKN 25KFT CIGS EXPECTED THROUGH 13Z-17Z BEFORE MID-DECK BEGINS TO MOVE
IN. AFTER 21Z ACROSS WESTERN TERMINALS OVC050 EXPECTED BY 21Z AND
SLOWLY PROGRESSING EAST FROM THERE. OVERALL NO RESTRICTIONS
EXPECTED THROUGH 06Z FRIDAY THOUGH A STRAY SHOWER WILL BE POSSIBLE
TOWARD THE END OF TAF VALID TIME.
EAST TO SOUTHEAST WINDS AROUND 5 KTS OVERNIGHT BECOMING SOUTH
AROUND 8 KTS STARTING 15Z.
OUTLOOK...
LATE THURSDAY NIGHT INTO FRIDAY...MVFR AND POSSIBLY IFR
RESTRICTIONS LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT
SHSN...ESPECIALLY CENTRAL NY TERMINALS.
SUNDAY NIGHT AND MONDAY MORNING...VFR.
MONDAY AFTN...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS
TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN/MLJ
SHORT TERM...DJN
LONG TERM...RRM
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
312 AM EST THU NOV 21 2013
.SYNOPSIS...
A WEAK TROUGH WILL AFFECT THE NORTH CAROLINA COAST TODAY. STRONG HIGH
PRESSURE WILL LINGER NORTH AND EAST OF THE AREA TONIGHT AND FRIDAY.
A STRONG COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT AND MOVE
OFFSHORE SATURDAY AND SATURDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD
IN FROM THE NORTHWEST SUNDAY AND MONDAY. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST TUESDAY AND CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 310 AM THURSDAY...WITH A WEAK INVERTED TROUGH OFFSHORE...AND
AN ONSHORE FLOW BELOW 850 MB...SHOWERS HAVE BECOME A BIT MORE
WIDESPREAD OVER THE PAST COUPLE OF HOURS. THIS IS BEING BEST
HANDLED BY THE RAP MODEL...WHICH SHOWS THIS LIGHT RAINFALL
LINGERING IN THE AREA THROUGH ALOT OF THE DAY. AS A RESULT WILL
HAVE 20 TO 30 PCT POPS OVER MOST OF THE AREA FOR THE BALANCE OF
THE OVERNIGHT AND DAYTIME HOURS. WITH THE WARMER ONSHORE
FLOW...MAXIMUM TEMPERATURES WILL BE WELL INTO THE 60S OVER MOST OF
THE AREA TODAY. WINDS WILL DECREASE AS THE GRADIENT DIMINISHES
WITH A PIECE OF THE LARGE SURFACE HIGH BREAKING OFF OVER
SOUTHEASTERN VIRGINIA/NORTHEASTERN NORTH CAROLINA LATER TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 310 AM THURSDAY...THE THREAT OF ANY PRECIPITATION SHOULD END
BY THIS EVENING...WITH SOME PARTIAL CLEARING OVERNIGHT. THE AXIS
OF THE SURFACE RIDGE WILL SETTLE OVER THE AREA TONIGHT...BUT WITH
A LIGHT ONSHORE FLOW...MINIMUM TEMPERATURES WILL RANGE IN THE
UPPER 40S TO MID 50S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 3 AM THU...00Z GFS/ECMWF IN GOOD AGREEMENT THROUGH THE END
OF THE WEEK. UPPER RIDGE OVER THE REGION BECOMES ZONAL AS POWERFUL
UPPER TROF BEGINS TO MOVE TOWARD THE SOUTHEAST...WHILE AT THE
SURFACE THE HIGH OVER THE CAROLINAS WILL MOVE SOUTHEAST. THE STRONG
COLD FRONT SWEEPS THROUGH ON SATURDAY. PREFER THE TIMING OF THE
FRONTAL PASSAGE FROM THE ECMWF AS IT MATCHES UP WELL WITH THE HPC
SOLUTION. GFS APPEARS ABOUT 6 HOURS TOO FAST. THE FRONT WILL ENTER
THE NORTHERN COUNTIES AROUND 12Z AND WILL BE SOUTH OF THE ENTIRE
AREA BY 00Z SUNDAY. GOOD LIFT AND CONVERGENCE ALONG THE FRONT.
HAVE KEPT POPS AT 40%. MUCH COLDER AND DRIER AIRMASS QUICKLY
OVERSPREADS THE REGION BEHIND THE FRONT. LIKE THE LAST ARCTIC
BLAST NOT TOO LONG AGO IT APPEARS THIS ONE WILL NOT BE AROUND FOR
VERY LONG EITHER. THE SURFACE RIDGE OVER THE NORTHERN PLAINS
SATURDAY WILL BE OVER THE CAROLINAS MONDAY THEN OFF THE COAST
TUESDAY...SO COLD NORTHERLY FLOW SATURDAY WILL BECOME SOUTHERLY ON
TUESDAY. RESULTING HIGHS WILL BE ONLY IN THE LOWER TO MID 40S
SUNDAY BUT WARMING QUICKLY TO THE MID AND UPPER 50S ON TUESDAY.
MODELS NOT HANDLING VERY WELL THE SYSTEM HEADING OUT OF THE GULF
NEXT WEEK. LOOKS LIKE THE ECMWF HAS A SLIGHT EDGE AT THE SURFACE
WHEN COMPARED TO THE HPC SOLUTION. HAVE RAISED POPS TO 40-50
PERCENT TUESDAY AND 50 PERCENT FOR WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 1245 AM THU...DECK OF CLOUDS AROUND 4000 FEET WILL LINGER
THROUGH THE OVERNIGHT HOURS...ALTHOUGH A BRIEF PERIOD OF MVFR
CEILINGS MAY OCCUR...ESPECIALLY AT KOAJ. SOME LIGHT SHOWERS ARE
OCCURRING BUT THEY WILL BE LIGHT AND SHOULD NOT AFFECT CEILINGS OR
VSBYS VERY MUCH. NOT MUCH CHANGE IN THE CEILING HEIGHT IS EXPECTED
DURING THURSDAY AS GENERALLY VFR CONDITIONS CONTINUE. EXPECT A
BROKEN DECK AROUND 10000 FEET BY TONIGHT.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...VFR THROUGH FRIDAY. THE EXCEPTION WILL BE A FEW
HOURS EITHER SIDE OF 12Z FRIDAY AND SATURDAY WITH THE POSSIBILITY
OF SOME VFR/MVFR FOG. SCATTERED SHOWERS EXPECTED ON SATURDAY AHEAD
OF A STRONG COLD FRONT WITH MVFR CIGS/VSBYS. THE FRONT WILL PASS
THROUGH FROM THE NORTH DURING THE DAY WITH WINDS RAPIDLY VEERING
FROM SOUTHWEST IN THE MORNING TO DUE NORTH BY LATE AFTERNOON. MUCH
DRIER AND COLDER AIRMASS QUICKLY OVERSPREADS THE REGION BEHIND THE
FRONT. SKIES WILL BECOME CLEAR/VFR EARLY SATURDAY EVENING. BREEZY
CONDITIONS EXPECTED SUNDAY WITH NORTH WINDS 15-25 KNOTS. SURFACE
RIDGE WILL BUILD TOWARD THE AREA MONDAY. VFR CONDITIONS CONTINUE
WITH HIGH CLOUD DECK FILTERING IN DURING THE DAY AND GRADUALLY
LOWERING ALONG WITH LIGHT AND VARIABLE WINDS.
&&
.MARINE...
.SHORT TERM /TODAY AND TONIGHT/...
AS OF 315 AM THURSDAY...N/NE WINDS ARE GENERALLY 15 KNOTS OR LESS
CURRENTLY AS WINDS CONTINUE TO TREND DOWNWARD. SEAS AT ALL OF THE
PLATFORMS REMAIN AT 6 TO 7 FEET...SO A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT FOR TODAY...ENDING FROM NORTH TO SOUTH AS THE
DAYS WEARS ON. SEAS SHOULD SLOW SUBSIDE TO 5 FEET OR LESS BY LATE
TONIGHT AS EASTERLY WINDS DROP TO 10 KNOTS OR LESS OVER MOST OF
THE COASTAL WATERS AND SOUNDS.
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...USED A BLEND OF THE 00Z GFS/ECMWF FOR THE MARINE
WINDS THROUGH FRIDAY NIGHT. GFS IS RUNNING AROUND 6 HOURS TOO FAST
WITH THE TIMING OF THE FRONT ON SATURDAY AND PREFER THE ECMWF. THE
SURFACE RIDGE ALONG THE EAST COAST FRIDAY WILL QUICKLY MOVE
SOUTHEAST OFF THE COAST FRIDAY NIGHT. FRIDAY APPEARS TO BE THE
BEST BOATING DAY IN THE LONG TERM PORTION OF THE FORECAST. EAST
FLOW FRIDAY MORNING WILL BECOME SOUTHERLY IN THE AFTERNOON THEN
SOUTHWEST FRIDAY NIGHT AND CONTINUING INTO SATURDAY. WINDS WILL
AVERAGE 5-10 KNOTS AND SEAS 2-4 FEET FRIDAY. WINDS AND SEAS WILL
GRADUALLY INCREASE AFTER THAT FRIDAY NIGHT INTO SATURDAY AS A
STRONG COLD FRONT APPROACHES. THE FRONT WILL ENTER THE NORTHERN
WATERS SATURDAY AROUND 12Z...MOVE THROUGH THE CENTRAL WATERS
AROUND 18Z AND WILL BE SOUTH OF THE SOUTHERN WATERS BY 00Z SUNDAY.
STRONG SMALL CRAFT CONDITIONS WILL DEVELOP QUICKLY BEHIND THE
FRONT SPREADING ACROSS THE MARINE ZONES FROM NORTH TO SOUTH
SATURDAY NIGHT. CONDITIONS WILL IMPROVE EARLY NEXT WEEK AS A
SURFACE RIDGE BUILDS INTO THE AREA WITH WINDS/SEAS DIMINISHING AS
A RESULT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...HSA
AVIATION...CTC/HSA
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1242 AM EST THU NOV 21 2013
.SYNOPSIS...
STRONG HIGH PRESSURE WILL EXTEND SOUTHWEST INTO THE REGION THROUGH
THURSDAY THEN MOVE OFFSHORE FRIDAY. A COLD FRONT WILL APPROACH
FROM THE WEST FRIDAY NIGHT AND MOVE OFFSHORE LATE SATURDAY. STRONG
HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND MONDAY.
LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST TUESDAY AND CROSS
THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1240 AM THURSDAY...WEAK INVERTED TROUGH OFFSHORE IS LEADING
TO SOME LIGHT SHOWERS OFF CORE BANKS AND THE SOUTHERN PORTION OF
THE OUTER BANKS. THE RAP AND 4KM WRF MODELS INDICATE THAT SOME OF
THIS PRECIPITATION WILL REACH LAND AREAS OVERNIGHT AND HAVE ADDED
A SLIGHT POP TO THE FORECAST BASICALLY FROM CAPE LOOKOUT TO CAPE
HATTERAS. ANY RAINFALL AMOUNTS WILL BE VERY LIGHT. MID AND HIGH
CLOUDS WILL CONTINUE TO STREAM OVER THE AREA FROM THE WEST
OVERNIGHT AND TEMPERATURES WILL LIKELY ONLY FALL A COUPLE OF MORE
DEGREES BY MORNING.
&&
.SHORT TERM /FRIDAY/...
AS OF 210 PM WEDNESDAY...WL CONT TO SEE PLENTY OF CLOUDS OVER THE
AREA WITH MOISTURE BELOW 10000 FT PER ONSHORE FLOW AROUND HIGH PRES.
HGTS ALOFT WILL BE RISING SO NOT EXPECTING PRECIP OVER LAND WITH
NO FORCING. WILL SEE ENOUGH PEAKS OF SUN FOR HIGHS 60 TO 65. GRDNT
IS MUCH WEAKER ALONG THE CST THU AND EXPECT WINDS MAINLY IN THE 10
TO 15 MPH RANGE ESPCLY LATER IN THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WED...HIGH PRESSURE TO THE NORTH WILL REMAIN IN
CONTROL THU NIGHT THROUGH FRI. WILL CONTINUE TO KEEP FORECAST
DRY...THOUGH MODELS SHOW LOW LEVEL MOISTURE INCREASING AND
POSSIBLE LIGHT SHOWERS ALONG THE SOUTHERN ZONES. FRI AND SAT
EXPECT TEMPS NEAR CLIMO...WITH RETURN FLOW RE-
DEVELOPING...GENERALLY 65-70 DEGREES. A COLD FRONT WILL APPROACH
EASTERN NC FRI NIGHT...MOVING THROUGH THE AREA SATURDAY. WILL
MAINTAIN CHANCE POPS SAT THROUGH SAT EVENING...TAPERING OFF FROM W
TO E SAT NIGHT. COLD HIGH PRESSURE WILL BUILD IN FROM THE WEST
SUN/MON AS UPPER TROUGH MOVES OFF THE EASTERN US. A FEW COLD DAYS
EXPECTED WITH LOW LEVEL THICKNESS VALUES SUPPORTING HIGH TEMPS
GENERALLY IN THE 40S...ABOUT 20 DEGREES BELOW CLIMO. OVERNIGHT
LOWS SUN NIGHT/MON MORNING LIKELY IN THE 20S/MID 30S. COULD HAVE
POTENTIAL FOR FROST/FREEZE ALONG THE OUTER BANKS.
A LOW PRESSURE SYSTEM WILL DEVELOP IN THE GULF OF MEXICO
TUESDAY...AND MOVE THROUGH THE SE US TUESDAY AND WEDNESDAY. ECMWF
AND GFS CONTINUE TO DIFFER IN SPECIFIC DETAILS...MAINLY
TIMING...TRACK AND STRENGTH. WPC CONTINUES TO FAVOR THE SLOWER
SOLUTION LEANING SLIGHTLY CLOSER TO THE GFS...SO WILL LEAN TOWARDS
THAT FOR NOW. GOOD RAIN CHANCES EXPECTED WITH THIS SYSTEM...AND
INCREASED POPS TO HIGH CHANCE FOR TUE NIGHT/WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SHORT TERM /TONIGHT AND THU/...
AS OF 1245 AM THU...DECK OF CLOUDS AROUND 4000 FEET WILL LINGER
THROUGH THE OVERNIGHT HOURS...ALTHOUGH A BRIEF PERIOD OF MVFR
CEILINGS MAY OCCUR...ESPECIALLY AT KOAJ. NOT MUCH CHANGE IN THE
CEILING HEIGHT IS EXPECTED DURING THURSDAY AS GENERALLY VFR
CONDITIONS CONTINUE.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 215 PM WED...PRED VFR CONDITIONS EXPECTED THROUGH FRI NIGHT.
BRIEF PATCHY FOG AND STRATUS WILL BE POSSIBLE THU NIGHT AND FRI
NIGHT WITH INCREASING LOW LEVEL MOISTURE. A COLD FRONT WILL MOVE
THROUGH THE AREA SAT WITH SCT SHOWERS DEVELOPING...PERIODS OF SUB-
VFR CONDITIONS WILL BE POSSIBLE SAT AND SAT NIGHT. HIGH PRESSURE
WILL BUILD OVER THE AREA SUN AND MON WITH PRED VFR CONDITIONS WITH
GUSTY N/NW WINDS SUN.
&&
.MARINE...
.SHORT TERM /THROUGH THU/...
AS OF 1245 AM THURSDAY...SEAS REMAIN IN THE 6 TO 7 FOOT RANGE AT
THE BUOYS ALONG THE COAST WITH THE BUOY 10 MILES NORTHEAST OF
DUCK...THE BUOY 13 MILES EAST OF OREGON INLET AND DIAMOND BUOY ALL
REPORTING 7 FEET. WINDS HAVE SUBSIDING TO GENERALLY 15 TO 20 KNOTS
AT ALL SITE. ON THUR AS THE HIGH TO THE N WEAKENS AND SHIFTS E
WILL CONT TO SEE WINDS DIMINISH WITH DIR BECOMING MORE
ENE...SPEEDS SHOULD BE AOB 15 KTS LATE. SEAS WILL SLOWLY SUBSIDE
WITH SCA ENDING LATE DAY OR EVENING ALL WTRS.
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 215 PM WED...HIGH PRESSURE TO THE NORTH WILL CONTINUE TO BE
THE DOMINANT FEATURE THROUGH FRI NIGHT. E/NE WINDS GENERALLY 10KT
OR LESS THU NIGHT THROUGH FRI...WITH WINDS VEERING BECOMING SWLY
FRI NIGHT INTO SAT. SWLY WINDS WILL INCREASE TO 10-20KT SAT AHEAD
OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE
WATERS SAT EVENING. STRONG N/NW WINDS 15-25KT WILL DEVELOP BEHIND
THE FRONT LATE SAT NIGHT AND CONTINUE INTO SUN NIGHT. SEAS WILL
BUILD TO 4-8FT...HIGHEST NORTH OF OCRACOKE. SCA CONDITIONS
EXPECTED TO DEVELOP SAT EVENING AND CONTINUE THROUGH SUN NIGHT.
HIGH PRESSURE WILL BUILD OVER THE AREA SUN AND MON. NORTHERLY
WINDS WILL SLOWLY DIMINISH LATE SUN NIGHT AND BECOME SLY MON NIGHT
INTO TUE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...CQD
AVIATION...CTC/CQD
MARINE...CTC/CQD/RF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1251 AM CST THU NOV 21 2013
.UPDATE...
ISSUED AT 1251 AM CST THU NOV 21 2013
COLD HIGH PRESSURE CONTINUES TO PUSH INTO THE STATE FROM THE
NORTHWEST. CLEARING AT WILLISTON...AND WESTERN EDGE OF CLOUDS
EXPECTED TO MOVE EASTWARD DURING THE EARLY MORNING HOURS. LINGERING
FLURRIES FOR ANOTHER HOUR OR TWO FROM NEAR HETTINGER TO
BISMARCK/MANDAN TO HARVEY...LIGHT SNOW CONTINUING EAST OF THIS LINE
FOR 2-4 HOURS TAPERING TO FLURRIES. LITTLE ADDITIONAL ACCUMULATION
EXPECTED. TEMPERATURES AROUND ZERO IN CROSBY IN THE FAR NORTHWEST
CORNER OF NORTH DAKOTA. EXPECTING LOWS OF 5 BELOW TO NEAR 15 BELOW
IN THE FAR NORTHWEST CORNER THIS MORNING...WITH WIND CHILLS OF 20 TO
30 BELOW ZERO AND WILL KEEP THE CURRENT WIND CHILL ADVISORY GOING
FOR THE DIVIDE/WILLIAMS/BURKE/MOUNTRAIL COUNTY AREA.
UPDATE ISSUED AT 947 PM CST WED NOV 20 2013
DID ISSUE A WIND CHILL ADVISORY FOR THE NORTHWEST TONIGHT INTO
THURSDAY MORNING WITH WIND CHILLS OF -25 TO -30 EXPECTED.
TEMPERATURES WILL QUICKLY FALL BELOW ZERO ACROSS THE NORTHWEST BY
05 UTC AS SKIES CLEAR WITH FRESH SNOW AS THE SURFACE HIGH
CONTINUES TO BUILD INTO WESTERN NORTH DAKOTA.
UPDATE ISSUED AT 645 PM CST WED NOV 20 2013
UPDATE TO CANCEL THE WINTER WEATHER ADVISORY FOR
WILLIAMS...DUNN...MOUNTRAIL...MCKENZIE AND RENVILLE COUNTIES.
HOWEVER...A WIND CHILL ADVISORY MAY BE NEEDED TONIGHT ACROSS THE
NORTHWEST. WIND CHILL VALUES MAY APPROACH -25 AS A QUICK DROP OFF
IN SURFACE TEMPERATURES TO NEAR -10 ARE EXPECTED WITH THE NEW SNOW
COVER AND CLEARING SKIES.
UPDATE ISSUED AT 447 PM CST WED NOV 20 2013
QUICK UPDATE TO EXPAND THE WINTER WEATHER ADVISORY INTO
RENVILLE...TOWNER...BOTTINEAU...PIERCE AND ROLETTE COUNTIES.
HEAVY BANDED SNOW IS EXPECTED TO RESULT IN 3 TO 5 INCHES OF SNOW
FOR THESE AREAS WITH VISIBILITIES NEAR ONE QUARTER OF A MILE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
LATEST RADAR AND WEATHER CAMERAS INDICATE SNOW FROM WEST CENTRAL
INTO NORTH CENTRAL NORTH DAKOTA. SNOW HAS BEEN HEAVY AT TIMES WITH
VISIBILITY DOWN TO A QUARTER. LATEST REPORTS AND ESTIMATES INDICATE
1-2 INCHES HAS FALLEN FROM WILLISTON TO DICKINSON. LIKELY SOME
HIGHER AMOUNTS IN A PERSISTENT BAND ACROSS MAINLY MCKENZIE COUNTY.
THIS BAND HAS BECOMING MORE ENHANCED ACROSS MOUNTRAIL INTO WARD
COUNTY IN THE PAST HOUR.
EXPECT ANOTHER 2 TO 4 HOURS OF LIGHT TO MODERATE SNOW IN THE
ADVISORY AREA...BEFORE SHIFTING FARTHER SOUTH AND EAST. 12 UTC
MODEL GUIDANCE AND THE LATEST MESOSCALE RAP AND HRRR SHOW
PRECIPITATION ENDING QUICKLY AROUND 00 UTC IN WESTERN NORTH DAKOTA
AS BEST FRONTOGENETICAL FORCING SHIFTS INTO CENTRAL NORTH DAKOTA.
THIS SHOULD PUT AN END TO ACCUMULATING SNOW OVER THE ADVISORY AREA
BY MID EVENING. CURRENT HAZARD GOES UNTIL 10 PM AND EVENING SHIFT
CAN CANCEL EARLY IF NEEDED.
BEST SNOW CHANCES ARE OVER CENTRAL NORTH DAKOTA THIS EVENING. AND
ACCUMULATIONS OF AROUND AN INCH ARE POSSIBLE OVER THE SOUTH
CENTRAL AND FAR SOUTHWEST...FROM BOWMAN AND HETTINGER TO BISMARCK
AND JAMESTOWN. LESSER AMOUNTS...UNDER AN INCH ARE EXPECTED FROM
SELFRIDGE TO LAMOURE AND OAKES. MODEL SOUNDINGS INDICATE WARM
TEMPERATURES ALOFT IN THE FAR SOUTH CENTRAL...THUS HAVE INCLUDED A
MENTION OF MIXED PRECIPITATION SOUTH OF BISMARCK TO THE SOUTHERN
JAMES RIVER VALLEY.
PRECIPITATION ENDS QUICKLY IN THE CENTRAL AS THE UPPER TROUGH
TRANSLATES INTO THE AREA LATE TONIGHT. THEN WE ARE LOOKING AT VERY
COLD TEMPERATURES AND WIND CHILLS LATE TONIGHT AND THURSDAY. WIND
CHILLS FROM 10 BELOW SOUTH TO 20 BELOW NORTHWEST CAN BE EXPECTED
EARLY THURSDAY MORNING.
THURSDAY IS EXPECTED TO BE DRY BUT COLD WITH HIGHS OF 10 TO 20 ABOVE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE COLDEST AIR OF THE
SEASON THUS FAR FOR FRIDAY NIGHT INTO SATURDAY MORNING.
THE 12 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A WEAK
CLIPPER SYSTEM PROPAGATING NEAR THE INTERNATIONAL BORDER THURSDAY
NIGHT INTO FRIDAY MORNING. THIS IS FOLLOWED BY A 1050 MB HIGH
BUILDING ACROSS NORTH DAKOTA THROUGH THE REMAINDER OF THE DAY ON
FRIDAY. WHEN COMBINED WITH THE SNOW COVER THAT WILL BE ACROSS THE
NORTH...THE COLDEST NIGHT OF THE SEASON THUS FAR IS EXPECTED WITH
LOWS NEAR -15 NORTH...WITH THE SINGLE DIGITS BELOW ZERO ACROSS THE
SOUTH. DID UNDERCUT ALL GUIDANCE BY AT LEAST FIVE DEGREES ACROSS
THE SNOWPACK FOR LOWS FRIDAY NIGHT. WIND CHILLS MAY APPROACH
ADVISORY CRITERIA OF -25 TO -30 EARLY SATURDAY MORNING ACROSS THE
NORTH. HIGHS WARM BACK INTO THE 30S ON SUNDAY IN THE WARM SECTOR
OF A SOUTHERN CANADA CLIPPER. HOWEVER...THIS WARM UP IS BRIEF AS
ANOTHER COOL CANADIAN AIRMASS PROPAGATES SOUTH EARLY NEXT WEEK
UNDER NORTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1251 AM CST THU NOV 21 2013
IFR CONDITIONS IN SNOW AT KJMS THROUGH 10Z...THEN MVFR THROUGH 15Z.
MVFR STRATUS AT KBIS THROUGH 10 UTC. OTHERWISE....CONDITIONS WILL
REMAIN VFR ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE NIGHT
AS SURFACE HIGH PRESSURE BUILDS IN. NORTHWEST WINDS TO EVENTUALLY
BECOME SOUTHWEST LATER ON THURSDAY AFTERNOON/EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ001-002-
009-010.
&&
$$
UPDATE...JV
SHORT TERM...TWH
LONG TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1154 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 1154 PM CST WED NOV 20 2013
MADE SOME FURTHER ADJUSTMENTS TO POPS TO ALIGN WITH THE EASTWARD
PROGRESSION OF THE MAIN SNOW BAND. ADDED IN A PATCHY FREEZING
DRIZZLE MENTION DURING THE NEXT FEW HOURS FOR OUR SOUTH AND EAST
AS WE HAVE HAD SOME REPORTS FROM KFAR AND KBDE. HOWEVER...THE
FZDZ WILL NOT LAST LONG AS MODEL SOUNDINGS HAVE THE COLUMN
SATURATING FAIRLY QUICKLY AFTER 06Z. KEPT SNOW AMOUNTS CLOSE TO
WHAT WE HAD GOING WITH ONLY MINOR TWEAKS.
UPDATE ISSUED AT 927 PM CST WED NOV 20 2013
MAIN ADJUSTMENT WAS TO PUT OUT A QUICK WINTER WX ADVISORY FOR OUR
NORTHWESTERN CWA AND FAR NORTHERN VALLEY COUNTIES AS WE HAVE HAD
REPORTS OF NEARLY 5 INCHES AT STARKWEATHER AND AROUND 4 AT MADDOCK
AND SNOW CONTINUES. PUTTING THE ROEBBER METHOD SNOW RATIO
CALCULATIONS FOR BOTH THE GFS AND NAM PUTS OUR NORTHWESTERN CWA
INTO AN OVER 20 TO 1 RATIO...WHICH MAY EXPLAIN THE HIGHER AMOUNTS
THAN EXPECTED. THE SNOW BAND WILL CONTINUE TO SLOWLY TRANSITION
EASTWARD AS THE 700MB FRONTOGENESIS BAND MOVES FURTHER INTO THE
NORTHERN RED RIVER VALLEY. THE STRENGTH OF THE FRONTOGENESIS BAND
IS EXPECTED TO DIMINISH AS IT MOVES EAST SO THINK THAT THE AMOUNTS
FROM GFK AND FURTHER SOUTH AND EAST WILL BE LIGHTER THAT THOSE IN
THE DVL AREA. CUT POPS IN THE SOUTH AS NOT MUCH HAS BEEN REACHING
THE GROUND OVER SOUTH CENTRAL ND AND MODELS HAVE BEEN TRENDING
LIGHTER WITH ANY SNOW IN THE SOUTHERN VALLEY. ALSO SLOWED THE
MOVEMENT OF SNOW INTO NORTHWESTERN MN. COOLED TEMPS DOWN A BIT
MORE IN THE NORTHWESTERN COUNTIES AS SINGLE DIGITS JUST TO OUR
NORTH AND WEST EVEN WITH CLOUD COVER CONTINUES TO FILTER INTO THE
AREA.
UPDATE ISSUED AT 642 PM CST WED NOV 20 2013
ADJUSTED POPS FOR GOING RADAR TRENDS. CURRENT SNOW BAND OVER THE
DVL AREA WILL MOVE SOUTHEASTWARD TONIGHT...WITH MODELS SHOWING
SOME WEAKENING. THE WRF AND ONE HRRR RUN SHOW VERY LITTLE SNOW
MAKING IT TO OUR SOUTHERN COUNTIES. THE 18Z NAM AND LATEST HRRR
RUN HOWEVER HAVE A NARROW BAND MOVING THROUGH LATE THIS EVENING.
CUT POPS IN THE SOUTH A BIT...BUT DID NOT REMOVE THEM COMPLETELY.
STILL THINK THAT THE 1 TO 3 INCHES NORTH OF HIGHWAY 200 WITH
HIGHEST AMOUNTS NEAR DVL SEEMS REASONABLE...SO WILL MAINTAIN SNOW
AMOUNTS. TEMPS HAVE BEEN FALLING IN THE NORTHWEST A BIT FASTER
THAN EXPECTED...AND THAT AREA HAS THE BEST CHANCE OF SEEING SOME
CLEARING TOWARDS MORNING. THUS...CUT LOWS A FEW DEGREES DOWN
FURTHER INTO THE SINGLE DIGITS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 339 PM CST WED NOV 20 2013
THE MAIN FORECAST CHALLENGES THIS AFTERNOON INCLUDE LIGHT SNOW
EVENT LATE TODAY AND TONIGHT...AND TEMPS THE NEXT SEVERAL DAYS.
THE COLD FRONT HAS PROGRESSED LITTLE OVER THE PAST FEW
HOURS...ALLOWING TEMPS INTO WC MN TO WARM NICELY...WITH KOTT SITTING
AT 49 DEGREES AS OF 21Z. AS AN UPPER SHORTWAVE TROUGH CONTINUES TO
PROPAGATE EASTWARD ACROSS SOUTHERN CANADA AND THE STRONGER COLD
SURGE ACCELERATES SOUTHEASTWARD...COLDER AIR WILL FILTER INTO THE
SOUTHEAST COUNTIES OVERNIGHT.
THE INITIAL BAND OF LIGHT SNOW THAT MOVED FROM PARTS OF THE DEVILS
LAKE BASIN INTO THE NORTHERN VALLEY HAS NOT BEEN HANDLED VERY WELL
BY THE MODELS...BUT HAS PUT DOWN SOME LIGHT SNOW ACCUMULATIONS FROM
THE DEVILS LAKE AREA EAST NORTHEASTWARD.
ATTENTION REMAINS FOCUSED ON AN AREA OF SNOW ACROSS NW AND NC ND
FORCED BY MID-LEVEL FRONTOGENESIS. SEVERAL RECENT OBS ACROSS NW ND
HAVE INDICATED +SN. 12Z RUNS OF THE NAM/ECMWF/GFS ALL BRING THE
BRUNT OF THIS BAND ACROSS THE DEVILS LAKE BASIN INTO THE NORTHERN
VALLEY...AND THIS MATCHES WELL WITH OBSERVED TRENDS. THUS AT THIS
POINT...IT STILL APPEARS THAT 1 TO 3 INCHES OF ACCUMULATION IS ON
TRACK FOR THESE AREAS....ALTHOUGH A FEW ISOLATED HIGHER AMOUNTS
CANNOT BE RULED OUT. MODELS DO SHOW A WEAKENING TREND OF THE
FRONTOGENETICAL BAND OVERNIGHT...SO CURRENT THINKING IS THAT
TOTALS WILL REMAIN MOSTLY BELOW ADVISORY THRESHOLDS.
HOWEVER...THE EXACT LOCATION OF THE BAND AND ITS INTENSITY WILL
NEED TO BE MONITORED OVERNIGHT. FARTHER SOUTHEAST...GENERALLY ONLY
VERY LIGHT ACCUMULATIONS ARE EXPECTED. WINDS WILL REMAIN IN THE 15
TO 20 MPH RANGE OVERNIGHT...WITH SOME HIGHER GUSTS. HAVE NOT
MENTIONED ANY BLOWING SNOW...BUT THIS WILL BE SOMETHING TO WATCH
AS WELL.
AS HIGH PRESSURE AREA BUILDS INTO WESTERN ND BY LATE
TONIGHT...THE COLUMN BEGINS TO DRY OUT...SO SOME CLEARING IS
POSSIBLE LATE TONIGHT OVER THE DEVILS LAKE REGION. THIS MAY AFFECT
HOW LOW TEMPS FALL IN THIS AREA. OTHERWISE...CLOUDS WILL PERSIST
OVER MOST OF THE AREA TONIGHT. DESPITE PERSISTENT LOW-LEVEL COLD
ADVECTION...TEMPS SHOULD STAY MAINLY IN THE TEENS ACROSS THE
SOUTHEAST HALF OF THE AREA OVERNIGHT. .
FOR THURSDAY...THERE COULD BE A BIT OF LINGERING LIGHT SNOW EAST OF
THE VALLEY...WITH SFC HIGH PRESSURE AND CONTINUED COLD ADVECTION
LIMITING THE TEMP RISE...EVEN WITH SOME SUNSHINE...ESPECIALLY ACROSS
THE NORTH. TOMORROW NIGHT...WARM ADVECTION DEVELOPS AHEAD OF AN
UPPER SHORTWAVE TROUGH DIVING SOUTHEASTWARD FROM CANADA ON THE
PERIPHERY OF AN AMPLIFYING RIDGE ACROSS THE WESTERN CONUS. A MAJOR
QUESTION WILL BE HOW FAR TEMPS CAN FALL WITH DEVELOPING WARM
ADVECTION GIVEN SOME NEW SNOW ON THE GROUND IN PLACES. AT THIS
POINT KEPT LOWS MAINLY IN THE SINGLE DIGITS TO LOW TEENS. THE 12Z
GFS/ECMWF/NAM ALL KEEP ANY PRECIP FROM SYSTEM TO THE SOUTH OUT OF
THE AREA. AS A RESULT...MOST AREAS SHOULD REMAIN DRY THURSDAY
NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 PM CST WED NOV 20 2013
THE NEXT WAVE DROPS ACROSS THE REGION ON FRIDAY...WITH A REINFORCING
COLD FRONT MOVING SOUTHWARD DURING THE DAY. SOME LIGHT SNOW MAY
ACCOMPANY THE SYSTEM WITH SOME Q-VECTOR CONVERGENCE IN THE
700-300MB LAYER AND A 300 MB JET STREAK NOSING INTO THE DAKOTAS.
A STRONG 1049 MB ARCTIC HIGH WILL BUILD SOUTHWARD FRIDAY NIGHT INTO
SATURDAY...CENTERED OVER CENTRAL OR WESTERN ND SATURDAY MORNING.
BEHIND THE FRONT...925 MB TEMPS WILL FALL TO AROUND -16 TO
-20C...HIGHEST TO THE NORTH. TEMPS FRIDAY NIGHT SHOULD BE DOWN INTO
AT LEAST THE SINGLE DIGITS...WITH THE BEST LIKELIHOOD FOR SUBZERO
READINGS ACROSS NORTHWESTERN AREAS...WHERE SOME SNOWCOVER MAY EXIST
AND WINDS WILL BE LIGHTEST. TEMPS ON SATURDAY WILL LIKELY REMAIN
WELL BELOW NORMAL IN THE SINGLE DIGITS AND TEENS...WITH WEAK MIXING
UNDER THE SFC HIGH.
500 MB PATTERN BECOMES A BIT MORE WEST-NORTHWEST AS TROUGH AND COLD
AIRMASS MOVE EAST SUNDAY AND MONDAY. THUS LOOK FOR TEMPS TO
MODERATE QUICKLY SUN-MON BACK TO NEAR NORMAL VALUES. A FAST MOVING
SFC LOW WILL MOVE THRU CNTRL MANITOBA INTO WRN ONTARIO TO LAKE
SUPERIOR SUNDAY-MON...SPREADING SOME LOW CHANCES FOR LIGHT SNOW INTO
LAKE OF THE WOODS REGION. A SHOT OF COLDER AIR FOLLOWS THIS SFC LOW
FOR MID WEEK AS HIGH PRESSURE DROPS SOUTH. OUTSIDE OF SOME LOW
CHANCES FOR LIGHT SNOW IN LAKE OF THE WOODS AREA...DRY FCST FOR
SUNDAY INTO NEXT WEDENSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1154 PM CST WED NOV 20 2013
CIGS HAVE BEEN MOSTLY MVFR ALTHOUGH THERE HAS BEEN SOME IFR CIGS
AT KBJI. THE HEAVIER SNOW BAND OVER KGFK HAS DROPPING VIS TO
AROUND 1SM...ALTHOUGH KDVL HAS STARTED COMING BACK UP. ACCOUNTED
FOR THE EASTWARD MOVEMENT OF THE SNOW BAND AND INCLUDED SOME TEMPO
GROUPS FOR KGFK...KTVF...AND KBJI AS WELL AS KDVL FOR LINGERING
FLURRIES. DO NOT THINK THAT ANY VIS WILL GO DOWN TO BELOW A MILE
AS THERE HAS BEEN A WEAKENING TREND. SNOW SHOULD MOVE OUT OF THE
AREA AFTER 12Z...ALTHOUGH SOME MVFR CIGS WILL HANG AROUND A BIT
LONGER INTO THE MORNING. EVENTUALLY THE LOWER CLOUDS WILL CLEAR
OUT AND LEAVE SOME SCATTERED TO BROKEN CIRRUS. NORTH WINDS WITH
HIGH GUSTS OVERNIGHT WILL DIMINISH DURING THE DAY ON THURSDAY AND
EVENTUALLY BECOME LIGHT AND VARIBLE AND THEN SHIFT TO THE
SOUTHWEST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR NDZ006>008-
014>016-024-026-054.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ004.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
844 AM MST THU NOV 21 2013
.UPDATE...
ISSUED AT 843 AM MST THU NOV 21 2013
A COLD FRONT WAS SLIPPING SOUTH ACROSS NE UT/NW CO THIS MORNING
AND APPEARS TO HAVE PUSHED TO ROUGHLY A MEEKER TO PRICE LINE.
PRECIPITATION WAS IN THE FORM OF SNOW AT CRAIG...MEEKER...AND JUST
CHANGED TO SNOW AT VERNAL. SURFACE AIR NEAR SATURATION IN MANY
PLACES FOR AREAS OF FOG AS WELL. 14Z RUC SHOWED THE FRONT STALLING
AROUND THE I-70 CORRIDOR OR A LITTLE SOUTH THIS AFTERNOON...WITH
HI-RESOLUTION HRRR MODEL INDICATING SOME OVERRUNNING PRECIPITATION
ACROSS NE UT/NW CO INTO THE AFTERNOON. WILL HAVE TO WATCH THIS
AREA FOR SNOW ACCUMULATION BUT FOR NOW ANTICIPATE THE TEMPS WILL
BE WARM ENOUGH TO PREVENT HIGHLIGHT CRITERIA SNOW ACCUMS THERE
TODAY. CLOUDS HAVE A CONVECTIVE NATURE ON VISIBLE SATELLITE IMAGES
THIS MORNING ACROSS SE UT/SW CO FOR A SHIFT TO MORE SHOWERY
PRECIPITATION AT LEAST IN THE SOUTHERN VALLEYS DURING THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
DEEP MOISTURE CONTINUES TO LINGER OVER THE REGION FROM THE PAST
FEW DAYS OF ATMOSPHERIC SATURATION. 300K/305K MOISTURE TRANSPORT
VECTORS SHOW A STEADY STREAM OF ZONAL MOISTURE FROM ABOUT THE FOUR
CORNERS SOUTH...BUT THAT IS NOT STOPPING MOST OF WESTERN CO AND
EASTERN UT FROM CONTINUING TO PRECIPITATE EARLY THIS MORNING. IR
SATELLITE AND RADAR SHOW INDICATE SHOWERS WITH LOW CLOUD TOPS
MOVING NORTHEAST AND BEGINNING TO BREAK UP...BUT NEARLY EVERY WX
STATION IN THE CWA IS REPORTING LIGHT PRECIPITATION AND/OR FOG.
A CLOSED UPPER LEVEL LOW CURRENTLY OVER NORTHERN CA AND NEVADA IS
SLOWLY MAKING ITS WAY EASTWARD...AND AS IT DOES...A LONG FETCH OF
SOUTHWEST FLOW WILL PROVIDE STRONG ISENTROPIC UPLIFT OVER AN
ALREADY COOL AIRMASS. SIGNIFICANT SNOWFALL IS EXPECTED AT ALL
SOUTHERN CO/UT MOUNTAIN LOCATIONS.
ANOTHER MAJOR FACTOR IN TODAY/S WEATHER IS STRONG FRONTOGENESIS
WHICH WILL BE OVER NORTHERN UT AND CO AROUND NOON TODAY MAKING
IT/S WAY SOUTH TO THE FOUR CORNERS BY THURSDAY NIGHT. THIS
STRENGTHENING FRONTAL PASSAGE WILL LOWER SNOW LEVELS FROM NORTH TO
SOUTH TODAY BEFORE ERODING INTO THE LARGER TROUGH FUELED BY THE
CLOSED LOW OVER NEVADA. EXPECTING COLD ADVECTIVE-INDUCED SNOW
SHOWERS NORTH OF THE FRONT. SOUTHWEST FLOW WILL STRENGTHEN BY
THURSDAY NIGHT AND TRANSPORT A SLUG OF MOISTURE BACK INTO THE
REGION OVER A DEFORMATION ZONE LEFTOVER BY THE COLD FRONT FROM
THURSDAY AFTERNOON. WITH SUCH A SATURATED ENVIRONMENT ALREADY AND
A STRONG DEFORMATION ZONE...IT WILL NOT TAKE MUCH TO PRODUCE A LOT
OF PRECIPITATION WITHIN A MATTER OF HOURS OVERNIGHT AND FRIDAY
MORNING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
MODELS SHOW THE UPPER LEVEL LOW MOVING VERY SLOWLY WITH PIECES OF
ENERGY KEEPING CLOUD COVER AND PRECIPITATION IN THE PICTURE
THROUGH THE EARLY PART OF THE WEEKEND. NORTHERN UT/CO ARE NOT LIKELY TO
SEE MUCH IN THE WAY OF PRECIPITATION BY THE TIME FRIDAY NIGHT
ROLLS AROUND.
SATURDAY THROUGH WEDNESDAY...FOR THE MOST PART THE MID-RANGE
MODELS ARE IN MUCH BETTER AGREEMENT IN TIMING THE SW U.S. AS IT
MOVES FROM BAJA CALIFORNIA INTO NM SAT THROUGH MON. ON SAT THE
LOW CENTER SHOULD BE OVER SOUTHERN CA WITH ITS COLD FRONT
ORIENTATED N TO S OVER CENTRAL AND EASTERN AZ. THROUGHOUT SAT A
FOUNTAIN OF STRONG MOIST SOUTHERLY FLOW FEEDING INTO STRONG UPPER
DIVERGENCE WILL MOVE OVER SE UT AND SRN CO...ALL SPREADING OUT
INTO A DEFORMATION ZONE OVER CENTRAL AND NORTHERN CO AND UT. THIS
SETUP SHOULD CONTINUE WIDESPREAD PCPN OVER THE SOUTHERN TWO THIRDS
OF THE FORECAST AREA AND HAVE INCREASED CLOUD COVER AND POPS TO
REFLECT THIS.
THE GFS AND ECMWF BOTH PLACE THE CLOSED LOW OVER CENTRAL AZ AT
18Z ON SUNDAY AND PUSH THE COLD FRONT EAST OF THE AREA ALONG WITH
THE BEST UPWARD MOTION. ABOUT THIS TIME MOISTURE IS PROJECTED TO
BEGIN WRAPPING AROUND THE NORTH SIDE OF THE LOW...THOUGH THERE
ISN`T A STRONG TROWAL SIGNATURE IN THE TEMP FIELDS. STILL...THE
MOISTURE IN THE E AND NE FLOW TO THE NORTH OF THE LOW CENTER
SHOULD KEEP CLOUDS AND PCPN OVER THE SOUTHERN PART OF THE FORECAST
AREA UNTIL MONDAY MORNING.
TUESDAY AND WEDNESDAY...A RIDGE WILL BUILD OVER THE WESTERN U.S.
AND BRING A WARMING AND DRYING TREND OF CO AND UT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 348 AM MST THU NOV 21 2013
WIDESPREAD LOW CLOUDS AND PRECIPITATION OVER THE NEXT 24 HOURS WILL
PRODUCE PERIODS OF MVFR AND IFR CONDITIONS AT THE MOUNTAIN AND
HIGH VALLEY TAF SITES AND AIRPORTS. MOST MOUNTAINS AND HIGH
MOUNTAIN PASSES WILL BE OBSCURED BY CLOUDS AND SNOWFALL. OTHER TAF
SITES AND AIRPORTS WILL SEE PERIODS OF MVFR CIGS AND VSBYS FROM
RAIN OR SNOW.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR COZ018-019.
WINTER STORM WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR COZ014.
WINTER STORM WARNING UNTIL MIDNIGHT MST FRIDAY NIGHT FOR COZ009-
010-012-017.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM MST SATURDAY
FOR COZ022-023.
WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING FOR COZ013.
UT...WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR UTZ028.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR UTZ023.
&&
$$
UPDATE...JAD
SHORT TERM...JAM
LONG TERM...JAM/CC
AVIATION...CC
AREA FORECAST DISCUSSION
NWS MIAMI FL
932 AM EST THU NOV 21 2013
.UPDATE...
SOMEBODY APPARENTLY FORGOT TO FLIP THE CALENDAR AS THE 12Z MFL
SOUNDING LOOKS MORE LIKE EARLY TO MID OCTOBER WITH PWAT CLOSE TO
TWO INCHES AND CAPE OF OVER 1000 J/KG. WATER VAPOR IMAGERY
CONTINUES TO SHOW ZONAL FLOW ACROSS THE PENINSULA WITH A DEEP
PLUME OF MOISTURE STRETCHING FROM THE WESTERN GULF OF MEXICO INTO
THE ATLANTIC WITH SURFACE ANALYSIS SHOWING AN OLD DECAYING FRONTAL
BOUNDARY LYING UNDERNEATH. SOUTH FLORIDA IS IN THE WARM SECTOR AND
PLENTY OF DIURNAL HEATING WILL TAKE PLACE TODAY WITH AMPLE
SUNSHINE SOUTH OF A CLOUD DECK THAT IS LOCATED NEAR LAKE
OKEECHOBEE. THE SOUNDING ALSO SHOWS THE LOW LEVEL FLOW HAS BECOME
MORE EASTERLY BUT THEN BECOMES WESTERLY ABOVE 12-13 K FEET.
CURRENTLY ONGOING IS A BAND OF SHOWERS EAST OF PALM BEACH COUNTY
AND THE TREND WILL BE FOR ADDITIONAL ACTIVITY TO BUILD INLAND FROM
THIS BAND IN THE LOW LEVEL FLOW AND THEN SLOWLY PROPAGATE INLAND.
THIS IS WHAT THE HRRR SHOWS WHICH THEREFORE SEEMS REASONABLE AND
IT HAS BEEN PERFORMING QUITE WELL OVER THE LAST FEW DAYS. THE
WESTERLY FLOW ALOFT WILL OFFSET THE LOW LEVEL EASTERLIES AND ONCE
CONVECTION DEVELOPS INTO A FEW THUNDERSTORMS, MOVEMENT WILL BE
VERY SLOW SO THE POSSIBILITY OF LOCALLY HEAVY RAINS STILL WILL BE
PRESENT. IN ADDITION, THE ATMOSPHERE HAS DESTABILIZED SOMEWHAT
FROM 24 HOURS AGO AND CONVECTION WILL LIKELY DEVELOP OVER THE
MAINLAND EARLIER WHICH THE HRRR ALSO DEPICTS.
KOB
&&
.PREV DISCUSSION... /ISSUED 609 AM EST THU NOV 21 2013/
AVIATION...
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE OVER THE EAST COAST
TAF SITES TODAY INTO TONIGHT. SO WILL KEEP VCSH IN THE EAST COAST
TAF SITES THROUGH TONIGHT. THE WINDS WILL INCREASE FROM LIGHT AND
VARIABLE EARLY THIS MORNING TO 5 TO 10 KNOTS FROM THE EAST BY LATE
THIS MORNING INTO EARLY THIS AFTERNOON. THE CEILING AND VIS WILL
ALSO REMAIN IN THE VFR CONDITIONS TODAY INTO TONIGHT FOR THE EAST
COAST TAF SITES DUE TO THE UNKNOWN TIMING OF THE SHOWERS.
FOR KAPF TAF SITE...THE WINDS WILL REMAIN EASTERLY TODAY INTO
TONIGHT WITH SPEEDS OF 5 KNOTS OR LESS EXCEPT 5 TO 10 KNOTS DURING
THE AFTERNOON HOURS. THERE COULD BE SOME SHOWERS THIS AFTERNOON AT
KAPF TAF SITE...SO WILL KEEP THE VCSH IN THE FORECAST BETWEEN 15Z
AND 23Z TODAY. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR
CONDITIONS AT KAPF TAF SITE.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 346 AM EST THU NOV 21 2013/
SHORT TERM (TODAY-SATURDAY)...
DEEP MOISTURE PLUME EXTENDING FROM EAST TO WEST ALONG AND AHEAD OF A
STALLED FRONTAL BOUNDARY WILL CONTINUE TO SUPPORT SCATTERED SHOWERS
AND A FEW THUNDERSTORMS THROUGH A GOOD PORTION OF THE SHORT-TERM
PERIOD. MODEL SOUNDINGS AROUND THE LOCAL AREA REFLECT THIS MOIST
ENVIRONMENT AND SHOW PRECIPITABLE WATER VALUES RANGING FROM 1.6-1.9"
THROUGH FRIDAY...THEN DECREASING INTO THE 1.25-1.5" RANGE THROUGH
THE DAY SATURDAY AS SOME DRIER AIR FILTERS IN FROM NORTH TO SOUTH
AND THE BOUNDARY CONTINUES TO DIMINISH. RECENTLY ANIMATED WATER
VAPOR LOOP SHOWED MOSTLY ZONAL FLOW ACROSS THE REGION WITH PLENTY OF
MID/UPPER MOISTURE STREAMING OVERHEAD. THE LATEST SHORT-RANGE MODEL
GUIDANCE INDICATES RISING UPPER HEIGHTS AS A RIDGE BUILDS OVERHEAD
THROUGH FRIDAY. TEMPERATURES WILL REMAIN SEVERAL DEGREES ABOVE
AVERAGE WITH OVERNIGHT LOWS RANGING FROM THE MID 60S INLAND TO THE
LOWER 70S ALONG THE EAST COAST/METRO LOCATIONS EACH NIGHT. AFTERNOON
HIGHS ARE FORECAST TO REACH THE LOW TO MID 80S EACH DAY. THIS
COMBINED WITH DEWPOINTS REMAINING IN THE UPPER 60S WILL KEEP THE
HUMID CONDITIONS IN PLACE.
LONG TERM (SUNDAY-THURSDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS CONSISTENT AND IN DECENT
AGREEMENT ON THE LARGE SCALE SHOWING A QUITE PROGRESSIVE PATTERN
THROUGH THE UPCOMING WEEK FEATURING TWO FRONTAL BOUNDARIES OF
INTEREST TO OUR LOCAL AREA. THE FIRST OF THE TWO IS FORECAST TO
APPROACH AND MOVE THROUGH THE LOCAL AREA THROUGH THE DAY SUNDAY.
ALTHOUGH VERY LITTLE SENSIBLE WEATHER IS ANTICIPATED WITH THIS
BOUNDARY DUE TO A LIMITED SOURCE OF DEEP LAYER MOISTURE...THE MAIN
IMPACTS WILL COME ALONG THE COAST AND OUT ACROSS THE ADJACENT
COASTAL WATERS DUE TO STRONG NORTHEAST WINDS AND BUILDING SEAS/SURF
IN THE WAKE OF THE BOUNDARY...ESPECIALLY OVER THE ADJACENT ATLANTIC
WATERS. THIS WILL TRANSLATE TO A PERIOD OF HAZARDOUS RIP CURRENTS
ALONG THE EAST COAST BEACHES FROM JUPITER TO MIAMI BEACH LATE SUNDAY
THROUGH MONDAY.
FOR THE SECOND SYSTEM...CYCLOGENESIS IN RESPONSE TO A STRONG
SHORTWAVE TROUGH IS FORECAST THROUGH THE DAY MONDAY ALONG THE TEXAS
COAST BEFORE RACING ENE ALONG THE NORTHERN GULF COAST THROUGH
TUESDAY. A COLD FRONT ASSOCIATED WITH THIS FEATURE WILL APPROACH THE
FLORIDA PENINSULA THROUGH THIS TIME AND SWEEP THROUGH OUR LOCAL AREA
THROUGH THE DAY WEDNESDAY. THERE ARE SOME MINOR TIMING DIFFERENCES
BETWEEN THE GFS AND ECMWF DUE TO A MORE PROGRESSIVE ECMWF SOLUTION.
ALTHOUGH THERE REMAINS PLENTY OF UNCERTAINTY BEING THIS FAR OUT INTO
THE PERIOD...WE WILL ADVERTISE HIGHER RAIN CHANCES ASSOCIATED WITH
THIS BOUNDARY DUE TO BETTER FORCING AND MOISTURE ALONG AND AHEAD OF
THE FRONTAL BOUNDARY. DESPITE THE TWO FRONTAL PASSAGES NEXT WEEK...
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE AVERAGE THROUGH THE
EXTENDED PERIOD.
AVIATION...
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO AFFECT THE EAST
COAST TAF SITES TODAY...AS THE WINDS WILL REMAIN LIGHT AND
VARIABLE EARLY THIS MORNING INCREASING TO 5 TO 10 KNOTS FROM THE
EASTERLY DIRECTION LATE THIS MORNING INTO EARLY AFTERNOON. KFLL
AND KFXE COULD EVEN SEE HEAVY RAINFALL OFF AND ON IN THE NEXT
COUPLE OF HOURS WITH VIS AND CEILING FALL INTO THE MVFR
CONDITIONS. SO HAVE ADDED A TEMPO GROUP FOR THE VIS AND CEILING
UNTIL 08Z FOR KFLL AND KFXE TAF SITES. THE CEILING AND VIS OVER
REST OF THE EAST COAST TAF SITES WILL REMAIN IN THE VFR CONDITIONS
WITH VCSH.
THE WINDS AT KAPF TAF SITE WILL REMAIN LIGHT AND VARIABLE THROUGH
EARLY THIS MORNING BEFORE INCREASING TO 5 TO 10 KNOTS FROM THE
EASTERLY DIRECTION LATE THIS MORNING IN EARLY THIS AFTERNOON. THE
WEATHER WILL REMAIN DRY THROUGH 15Z BEFORE SOME SHOWERS COULD
AFFECT THE TAF SITE FOR THE AFTERNOON HOURS. SO HAVE ADDED VCSH TO
KAPF TAF SITE AFTER 15Z TODAY. THE CEILING AND VIS WILL REMAIN IN
THE VFR CONDITIONS TODAY...DUE TO THE UNKNOWN TIMING OF THE
SHOWERS.
BNB
MARINE...
LIGHT WINDS WILL REMAIN IN PLACE ACROSS THE LOCAL WATERS THROUGH
FRIDAY AS A FRONTAL BOUNDARY STALLS OVER THE AREA. THE BEST CHANCE
FOR SHOWERS AND STORMS WILL REMAIN ALONG THE ATLANTIC COAST INTO
FRIDAY. A SMALL TO MODERATE NORTHERLY SWELL ASSOCIATED WITH FRESH TO
STRONG NORTHEAST WINDS NORTH OF THE FRONT WILL CONTINUE TO SPREAD
SOUTH OVER THE ATLANTIC WATERS THROUGH THE REMAINDER OF THE WEEK. A
STRONG COLD FRONT WILL PUSH THROUGH THE MARINE AREA BY THE END OF
THE WEEKEND WITH STRONG NORTHEAST WINDS AND BUILDING SEAS EXPECTED
SUNDAY NIGHT THROUGH MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 74 83 70 / 50 50 40 20
FORT LAUDERDALE 83 75 82 74 / 50 40 40 20
MIAMI 84 73 83 72 / 40 40 40 20
NAPLES 86 68 85 68 / 40 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
929 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE MOVING OFF THE COAST OF THE NORTHEAST STATES WILL
DIRECT A MOIST ONSHORE FLOW INTO THE FORECAST AREA TODAY AND
TONIGHT. WEAK HIGH PRESSURE WILL BE OVER THE AREA FRIDAY. AN
APPROACHING COLD FRONT WILL MOVE INTO THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPIC LIFT OVER THE PRESSURE RIDGE EXTENDING INTO THE
FORECAST AREA FROM THE NORTH WILL BRING CLOUDY SKIES TODAY. THE
NAM AND GFS SHOW BUILDING H5 HEIGHTS. BELIEVE THE MOISTURE WILL
REMAIN SHALLOW SO ANY RAINFALL SHOULD BE LIGHT AND IT IS
QUESTIONABLE WHETHER MEASURABLE RAIN WILL OCCUR. EXPECT MOST
OF THE AREA WILL HAVE OCCASIONAL SPRINKLES. USED AN AVERAGE OF
THE GFS AND ECMWF MOS FOR THE POP FORECAST. THE CHANCE OF
MEASURABLE RAIN WILL BE HIGHEST IN THE SOUTH AND WEST WHERE
MOISTURE WILL BE A LITTLE DEEPER. THE HRRR INDICATES GREATER
COVERAGE OF RAIN AREAS IN SOUTH AND WEST SECTIONS TODAY. WE USED
THE COOLER TEMPERATURE GUIDANCE BECAUSE OF THE WEDGE PATTERN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
ISENTROPIC LIFT OVER THE WEDGE RIDGE WILL CONTINUE TO BRING
CLOUDINESS TONIGHT. THE NAM AND GFS MOS POPS WERE IN POOR
AGREEMENT. THE NAM MOS DISPLAYED CATEGORICAL POPS WHILE THE GFS
MOS HAD SLIGHT CHANCE POPS. WE HAVE CONTINUED TO LEAN TOWARD THE
MORE CONSISTENT GFS...THINKING THE MOISTURE WILL REMAIN SHALLOW
UNDER H5 RIDGING. HOWEVER...EXPECT OCCASIONAL SPRINKLES WITH MORE
OF A CHANCE OF MEASURABLE RAIN IN THE SOUTH AND WEST CLOSER TO
DEEPER MOISTURE. THE NAM AND GFS SHOW LESS ISENTROPIC LIFT LATE
TONIGHT AS THE LOW-LEVEL FLOW DIMINISHES WITH WEAK HIGH PRESSURE
SETTLING OVER THE AREA. HIGH LOW-LEVEL MOISTURE AND LIGHT WIND
WILL LIKELY LEAD TO FOG. ALL OF THE GFS AND NAM MOS INDICATE FOG
LATE TONIGHT INTO FRIDAY MORNING. THE FOG MAY BECOME DENSE. WEAK
HIGH PRESSURE SHOULD REMAIN OVER THE AREA FRIDAY INTO FRIDAY NIGHT
AHEAD OF THE APPROACHING COLD FRONT. SUPPORT FOR RAIN APPEARS WEAK
DURING THIS TIME WITH THE MAIN FORCING ASSOCIATED WITH THE FRONT
STILL WEST OF THE AREA. WE USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE TONIGHT. USED THE COOLER HIGH TEMPERATURE GUIDANCE
BECAUSE OF CLOUDINESS FRIDAY. BELIEVE THE WARMER LOW TEMPERATURE
GUIDANCE IS BETTER FRIDAY NIGHT BECAUSE OF MIXING AHEAD OF THE
FRONT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DISPLAY A COLD FRONT MOVING THROUGH THE AREA
SATURDAY. MOST OF THE MOS GUIDANCE INDICATES CHANCE POPS SATURDAY AND
THIS APPEARS REASONABLE WITH H85 WESTERLY FLOW AHEAD OF THE FRONT
LIMITING CONVERGENCE AND MOISTURE. DRY AND COLD HIGH PRESSURE
SHOULD DOMINATE BEHIND THE FRONT FOR SUNDAY THROUGH MONDAY. THE GFS...
ECMWF...AND EKD MOS HAVE LOWS MAINLY IN THE MIDDLE 20S MONDAY
MORNING WITH THE HIGH OVER THE FORECAST AREA AND STRONG NET RADIATIONAL
COOLING. THE MODELS ARE ALSO IN GOOD AGREEMENT SHOWING LOW
PRESSURE FROM THE GULF OF MEXICO SPREADING DEEP MOISTURE INTO THE
FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. WE HAVE FORECASTED
LIKELY POPS BECAUSE OF THE MODEL CONSISTENCY. THE ECMWF WAS A
LITTLE FASTER LIFTING THE LOW NORTHEAST OF THE AREA WEDNESDAY SO
WE DID NOT FORECAST QUITE SO HIGH A POP ON THAT DAY. THE MODELS
INDICATE ENOUGH WARMING WILL OCCUR AHEAD OF THE SYSTEM FOR AN ALL-
LIQUID EVENT.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN MVFR CEILINGS WITH DETERIORATING CONDITIONS
TONIGHT.
WEAK ISENTROPIC LIFT OVER THE SURFACE HIGH PRESSURE SYSTEM
CURRENTLY IN PLACE HAS RESULTED IN MVFR STRATUS FOR TODAY. RADAR
CONTINUES TO SHOW PATCHY LIGHT RAIN OR SPRINKLES WHICH ARE
EXPECTED FOR MUCH OF THE DAY. THIS ACTIVITY IS NOT EXPECTED TO
BE MUCH IMPACT AT THE TERMINALS WITH MINIMAL IMPACT. MVFR
CEILINGS BELOW 2000FT SHOULD PERSIST THROUGH EARLY AFTERNOON BUT
THINK CEILINGS WILL RISE ABOVE 2000FT AFTER 18Z ALL TERMINALS AND
LOW VFR CEILINGS MAY BRIEFLY OCCUR TIL AROUND 01Z-03Z CAE/CUB/OGB.
STRONG AGREEMENT IN THE MODEL GUIDANCE IN ABUNDANT LOW LEVEL
MOISTURE RESULTING IN DEVELOPING IFR CEILINGS AND VISIBILITY
REDUCTION INTO THE MVFR/IFR RANGE AFTER 03Z-06Z. WINDS THROUGH THE
PERIOD WILL BE FROM THE NORTHEAST...WITH WIND SPEEDS AROUND 5 TO
10 MPH THROUGH 21Z THEN GRADUALLY WEAKENING TO LESS THAN 5 MPH
OVERNIGHT.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE EARLY FRIDAY.
SHOWERS AND ASSOCIATED RESTRICTIONS LATE FRIDAY INTO SATURDAY AS A
COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
649 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE MOVING OFF THE COAST OF THE NORTHEAST STATES WILL
DIRECT A MOIST ONSHORE FLOW INTO THE FORECAST AREA TODAY AND
TONIGHT. WEAK HIGH PRESSURE WILL BE OVER THE AREA FRIDAY. AN
APPROACHING COLD FRONT WILL MOVE INTO THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPIC LIFT OVER THE PRESSURE RIDGE EXTENDING INTO THE
FORECAST AREA FROM THE NORTH WILL BRING CLOUDY SKIES TODAY. THE
NAM AND GFS SHOW BUILDING H5 HEIGHTS. BELIEVE THE MOISTURE WILL
REMAIN SHALLOW SO ANY RAINFALL SHOULD BE LIGHT AND IT IS
QUESTIONABLE WHETHER MEASURABLE RAIN WILL OCCUR. EXPECT MOST
OF THE AREA WILL HAVE OCCASIONAL SPRINKLES. USED AN AVERAGE OF
THE GFS AND ECMWF MOS FOR THE POP FORECAST. THE CHANCE OF
MEASURABLE RAIN WILL BE HIGHEST IN THE SOUTH AND WEST WHERE
MOISTURE WILL BE A LITTLE DEEPER. THE HRRR INDICATES GREATER
COVERAGE OF RAIN AREAS IN SOUTH AND WEST SECTIONS TODAY. WE USED
THE COOLER TEMPERATURE GUIDANCE BECAUSE OF THE WEDGE PATTERN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
ISENTROPIC LIFT OVER THE WEDGE RIDGE WILL CONTINUE TO BRING
CLOUDINESS TONIGHT. THE NAM AND GFS MOS POPS WERE IN POOR
AGREEMENT. THE NAM MOS DISPLAYED CATEGORICAL POPS WHILE THE GFS
MOS HAD SLIGHT CHANCE POPS. WE HAVE CONTINUED TO LEAN TOWARD THE
MORE CONSISTENT GFS...THINKING THE MOISTURE WILL REMAIN SHALLOW
UNDER H5 RIDGING. HOWEVER...EXPECT OCCASIONAL SPRINKLES WITH MORE
OF A CHANCE OF MEASURABLE RAIN IN THE SOUTH AND WEST CLOSER TO
DEEPER MOISTURE. THE NAM AND GFS SHOW LESS ISENTROPIC LIFT LATE
TONIGHT AS THE LOW-LEVEL FLOW DIMINISHES WITH WEAK HIGH PRESSURE
SETTLING OVER THE AREA. HIGH LOW-LEVEL MOISTURE AND LIGHT WIND
WILL LIKELY LEAD TO FOG. ALL OF THE GFS AND NAM MOS INDICATE FOG
LATE TONIGHT INTO FRIDAY MORNING. THE FOG MAY BECOME DENSE. WEAK
HIGH PRESSURE SHOULD REMAIN OVER THE AREA FRIDAY INTO FRIDAY NIGHT
AHEAD OF THE APPROACHING COLD FRONT. SUPPORT FOR RAIN APPEARS WEAK
DURING THIS TIME WITH THE MAIN FORCING ASSOCIATED WITH THE FRONT
STILL WEST OF THE AREA. WE USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE TONIGHT. USED THE COOLER HIGH TEMPERATURE GUIDANCE
BECAUSE OF CLOUDINESS FRIDAY. BELIEVE THE WARMER LOW TEMPERATURE
GUIDANCE IS BETTER FRIDAY NIGHT BECAUSE OF MIXING AHEAD OF THE
FRONT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DISPLAY A COLD FRONT MOVING THROUGH THE AREA
SATURDAY. MOST OF THE MOS GUIDANCE INDICATES CHANCE POPS SATURDAY AND
THIS APPEARS REASONABLE WITH H85 WESTERLY FLOW AHEAD OF THE FRONT
LIMITING CONVERGENCE AND MOISTURE. DRY AND COLD HIGH PRESSURE
SHOULD DOMINATE BEHIND THE FRONT FOR SUNDAY THROUGH MONDAY. THE GFS...
ECMWF...AND EKD MOS HAVE LOWS MAINLY IN THE MIDDLE 20S MONDAY
MORNING WITH THE HIGH OVER THE FORECAST AREA AND STRONG NET RADIATIONAL
COOLING. THE MODELS ARE ALSO IN GOOD AGREEMENT SHOWING LOW
PRESSURE FROM THE GULF OF MEXICO SPREADING DEEP MOISTURE INTO THE
FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. WE HAVE FORECASTED
LIKELY POPS BECAUSE OF THE MODEL CONSISTENCY. THE ECMWF WAS A
LITTLE FASTER LIFTING THE LOW NORTHEAST OF THE AREA WEDNESDAY SO
WE DID NOT FORECAST QUITE SO HIGH A POP ON THAT DAY. THE MODELS
INDICATE ENOUGH WARMING WILL OCCUR AHEAD OF THE SYSTEM FOR AN ALL-
LIQUID EVENT.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN MVFR CEILINGS WITH DETERIORATING CONDITIONS
TONIGHT.
WEAK ISENTROPIC LIFT OVER THE SURFACE HIGH PRESSURE SYSTEM
CURRENTLY IN PLACE HAS RESULTED IN A LOWERING MVFR STRATUS DECK
EARLY THIS MORNING. RADAR SHOWING SOME PATCHY SPRINKLES OR EVEN A
POSSIBLE SHOWER AND THIS WILL LIKELY PERSIST THROUGH THE DAY TODAY
BUT THERE IS NOT EXPECTED TO BE MUCH IMPACT AT THE TERMINALS FROM
THESE LIGHT SHOWERS AND THEREFORE IS NOT INCLUDED IN THE FORECAST
DUE TO THE SCATTERED NATURE AND MINIMAL IMPACT. MVFR CEILINGS
BELOW 2000FT SHOULD PERSIST THROUGH EARLY AFTERNOON BUT THINK
CEILINGS WILL RISE ABOVE 2000FT AFTER 18Z ALL TERMINALS AND LOW
VFR CEILINGS MAY BRIEFLY OCCUR TIL AROUND 01Z-03Z CAE/CUB/OGB.
STRONG AGREEMENT IN THE MODEL GUIDANCE IN ABUNDANT LOW LEVEL
MOISTURE RESULTING IN DEVELOPING IFR CEILINGS AND VISIBILITY
REDUCTION INTO THE MVFR/IFR RANGE AFTER 03Z-06Z. WINDS THROUGH THE
PERIOD WILL BE FROM THE NORTHEAST...WITH WIND SPEEDS AROUND 5 TO
10 MPH THROUGH 21Z THEN GRADUALLY WEAKENING TO LESS THAN 5 MPH
OVERNIGHT.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE EARLY FRIDAY.
SHOWERS AND ASSOCIATED RESTRICTIONS LATE FRIDAY INTO SATURDAY AS A
COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
543 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE MOVING OFF THE COAST OF THE NORTHEAST STATES WILL
DIRECT A MOIST ONSHORE FLOW INTO THE FORECAST AREA TODAY AND
TONIGHT. WEAK HIGH PRESSURE WILL BE OVER THE AREA FRIDAY. AN
APPROACHING COLD FRONT WILL MOVE INTO THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPIC LIFT OVER THE PRESSURE RIDGE EXTENDING INTO THE
FORECAST AREA FROM THE NORTH WILL BRING CLOUDY SKIES TODAY. THE
NAM AND GFS SHOW BUILDING H5 HEIGHTS. BELIEVE THE MOISTURE WILL
REMAIN SHALLOW SO ANY RAINFALL SHOULD BE LIGHT AND IT IS
QUESTIONABLE WHETHER MEASURABLE RAIN WILL OCCUR. EXPECT MOST
OF THE AREA WILL HAVE OCCASIONAL SPRINKLES. USED AN AVERAGE OF
THE GFS AND ECMWF MOS FOR THE POP FORECAST. THE CHANCE OF
MEASURABLE RAIN WILL BE HIGHEST IN THE SOUTH AND WEST WHERE
MOISTURE WILL BE A LITTLE DEEPER. THE HRRR INDICATES GREATER
COVERAGE OF RAIN AREAS IN SOUTH AND WEST SECTIONS TODAY. WE USED
THE COOLER TEMPERATURE GUIDANCE BECAUSE OF THE WEDGE PATTERN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
ISENTROPIC LIFT OVER THE WEDGE RIDGE WILL CONTINUE TO BRING
CLOUDINESS TONIGHT. THE NAM AND GFS MOS POPS WERE IN POOR
AGREEMENT. THE NAM MOS DISPLAYED CATEGORICAL POPS WHILE THE GFS
MOS HAD SLIGHT CHANCE POPS. WE HAVE CONTINUED TO LEAN TOWARD THE
MORE CONSISTENT GFS...THINKING THE MOISTURE WILL REMAIN SHALLOW
UNDER H5 RIDGING. HOWEVER...EXPECT OCCASIONAL SPRINKLES WITH MORE
OF A CHANCE OF MEASURABLE RAIN IN THE SOUTH AND WEST CLOSER TO
DEEPER MOISTURE. THE NAM AND GFS SHOW LESS ISENTROPIC LIFT LATE
TONIGHT AS THE LOW-LEVEL FLOW DIMINISHES WITH WEAK HIGH PRESSURE
SETTLING OVER THE AREA. HIGH LOW-LEVEL MOISTURE AND LIGHT WIND
WILL LIKELY LEAD TO FOG. ALL OF THE GFS AND NAM MOS INDICATE FOG
LATE TONIGHT INTO FRIDAY MORNING. THE FOG MAY BECOME DENSE. WEAK
HIGH PRESSURE SHOULD REMAIN OVER THE AREA FRIDAY INTO FRIDAY NIGHT
AHEAD OF THE APPROACHING COLD FRONT. SUPPORT FOR RAIN APPEARS WEAK
DURING THIS TIME WITH THE MAIN FORCING ASSOCIATED WITH THE FRONT
STILL WEST OF THE AREA. WE USED THE GUIDANCE CONSENSUS FOR THE LOW
TEMPERATURE TONIGHT. USED THE COOLER HIGH TEMPERATURE GUIDANCE
BECAUSE OF CLOUDINESS FRIDAY. BELIEVE THE WARMER LOW TEMPERATURE
GUIDANCE IS BETTER FRIDAY NIGHT BECAUSE OF MIXING AHEAD OF THE
FRONT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DISPLAY A COLD FRONT MOVING THROUGH THE AREA
SATURDAY. MOST OF THE MOS GUIDANCE INDICATES CHANCE POPS SATURDAY AND
THIS APPEARS REASONABLE WITH H85 WESTERLY FLOW AHEAD OF THE FRONT
LIMITING CONVERGENCE AND MOISTURE. DRY AND COLD HIGH PRESSURE
SHOULD DOMINATE BEHIND THE FRONT FOR SUNDAY THROUGH MONDAY. THE GFS...
ECMWF...AND EKD MOS HAVE LOWS MAINLY IN THE MIDDLE 20S MONDAY
MORNING WITH THE HIGH OVER THE FORECAST AREA AND STRONG NET RADIATIONAL
COOLING. THE MODELS ARE ALSO IN GOOD AGREEMENT SHOWING LOW
PRESSURE FROM THE GULF OF MEXICO SPREADING DEEP MOISTURE INTO THE
FORECAST AREA FOR TUESDAY AND TUESDAY NIGHT. WE HAVE FORECASTED
LIKELY POPS BECAUSE OF THE MODEL CONSISTENCY. THE ECMWF WAS A
LITTLE FASTER LIFTING THE LOW NORTHEAST OF THE AREA WEDNESDAY SO
WE DID NOT FORECAST QUITE SO HIGH A POP ON THAT DAY. THE MODELS
INDICATE ENOUGH WARMING WILL OCCUR AHEAD OF THE SYSTEM FOR AN ALL-
LIQUID EVENT.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGH CONFIDENCE IN VFR VISIBILITIES THROUGH THE PERIOD...BUT LOWER
CONFIDENCE REGARDING CEILINGS.
STRONG SURFACE HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST
COAST OVER THE FORECAST AREA. A WEAK UPPER DISTURBANCE MOVING OVER
THE REGION IS AIDING IN WEAK REFLECTIVITY RETURNS OVER THE
MIDLANDS AND CSRA THOUGH NO OBSERVATIONS REPORT PRECIPITATION.
WEAK ISENTROPIC LIFTING HAS RESULTED IN FAIRLY WIDESPREAD MVFR
CEILINGS ACROSS THE SOUTHEAST. CAE/CUB BEGIN FORECAST WITH MVFR
CEILINGS AND EXPECT AGS/DNL/OGB WILL LOWER INTO MVFR RANGE BY 08Z
DESPITE CONFLICTING MOS GUIDANCE. EXPECT MVFR CEILINGS TO PERSIST
THROUGH THE MORNING HOURS BEFORE CEILINGS RISE DUE TO DIURNAL
INSOLATION AROUND 18Z. CEILINGS LIKELY TO FALL BACK TO MVFR AFTER
03Z AS ONSHORE FLOW CONTINUES WITH WEAK ISENTROPIC LIFT. SPRINKLES
POSSIBLE THROUGH THE PERIOD BUT MEASURABLE RAIN CHANCES ARE LOW
AND WILL NOT INCLUDE IN FORECAST DUE TO LACK OF VISIBILITY
RESTRICTIONS EXPECTED. WINDS SHOULD REMAIN NORTHEASTERLY AROUND 5
TO 10 MPH THROUGH THE FORECAST PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE THRU THU NT/EARLY
FRI. SHOWERS AND ASSOCIATED RESTRICTIONS LATE FRIDAY INTO SATURDAY
AS A COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
712 AM EST THU NOV 21 2013
.SYNOPSIS...
HIGH PRESSURE SLOWLY SLIDES DOWN THE NORTHEAST ATLANTIC COAST
TODAY AND FRIDAY. A STRONG COLD FRONT CROSSES THE REGION ON
SATURDAY. CANADIAN HIGH PRESSURE BUILDS INTO THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK...USHERING IN THE COLDEST
TEMPERATURES OF THE FALL SEASON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRONG ~1040MB (+2 STD DEV MSLP) HIGH OVER THE ST LAWRENCE RIVER
VALLEY THIS MORNING CONTINUES TO RIDGE OVER THE LOCAL AREA.
ALOFT...RIDGE HAS LOCATED OVER THE ERN CONUS AS THIS WEEKENDS
STORM SYSTEM TAKES SHAPE OVER SRN CANADA. H85 HIGH HAS LOCATED
OVER ERN NC WITH FLOW AROUND THE WRN PERIPHERY BECOMING S-SW BELOW
A STRONG SUBSIDENCE INVERSION. RETURN FLOW WILL ADVECT MOISTURE
OVER THE CAROLINAS NWD THIS MORNING. ALREADY BEGINNING TO SEE BKN-
OVC MID DECK SPREAD OVER THE LOCAL AREA. SHOWERS HAVE DEVELOPED
OFF THE SE NC COAST ALONG A WEAK COASTAL BOUNDARY EARLY THIS
MORNING. LATEST RUC GUIDANCE SUGGESTS THAT THE BOUNDARY WILL
LINGER THRU THE MORNING BEFORE WEAKENING. MODEST UPPER LEVEL
SUPPORT AND MOISTURE OVERRUNNING THE BOUNDARY WILL RESULT IN
ISOLATED SPRINKLES OVER MAINLY NE NC THRU MID MORNING. NO
MEASURABLE RAINFALL IS ANTICIPATED.
WITH AFOREMENTIONED STRONG HIGH TO THE NORTH AND RIDGING OVER THE
LOCAL AREA (CAD SETUP)...EXPECT CLOUD COVER TO CONTINUE TO THICKEN
THRU THE MORNING INTO THE AFTERNOON. WAA WILL ALSO ENHANCE THE
CLOUD COVER. OTHERWISE...SFC HIGH WILL BEGIN TO BREAK DOWN
TODAY...DRIFTING SWD OFF THE NE COAST BUT REMAINING RIDGED OVER
THE LOCAL AREA. RIDGE AXIS WILL PUSH OFFSHORE LATE TODAY...BUT WLY
FLOW WILL CONTINUE ALOFT. THE RESULTANT WAA WILL BE ENOUGH TO WARM
TEMPS INTO THE LOW-MID 50S INLAND TO UPPER 50S ALONG THE COAST
(SLIGHTLY BELOW NORMAL)...REGARDLESS OF CLOUDY SKIES AND
PERSISTENT ONSHORE FLOW. MODELS REMAIN RATHER AGGRESSIVE WITH LIGHT
RAIN/DRIZZLE TODAY BUT DRY LOW LEVELS WILL PREVENT ANY CHANCE FOR
PRECIP TO MATERIALIZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A STRONG COLD FRONT WILL CROSS THE LOCAL AREA LATE FRIDAY NIGHT
INTO EARLY SATURDAY MORNING...USHERING IN THE COLDEST AIR OF THE
FALL SEASON TO THE MID-ATLANTIC.
FRIDAY...
STRONG AMPLIFICATION OF NRN STREAM TROUGH ACROSS SRN CANADA AND
THE GREAT LAKES REGION WILL OCCUR FRIDAY. A LEAD SHORTWAVE WILL
PUSH AN ASSOCIATED COLD FRONT ACROSS THE OH VALLEY EARLY
FRI...REACHING THE CNTRL APPALACHIANS FRI AFTERNOON.
MEANWHILE...THE SFC HIGH WILL BREAK DOWN OVER THE REGION...WITH
SFC WINDS RETURNING TO THE SW. HOWEVER...WLY FLOW WILL CONTINUE
ALOFT...ADVECTING MOISTURE (+1 STD DEV PRECIP WATERS) FROM THE
KY/TN VALLEYS. INCREASING MOISTURE WILL REINFORCE THE CLOUD COVER
WITH MOSTLY CLOUDY-CLOUDY CONDITIONS EXPECTED AGAIN FRI.
INCREASING HEIGHTS/THICKNESSES AND H85 TEMPS +9C WILL TRANSLATE TO
TEMPS GENERALLY IN THE MID 60S...EVEN WITH CLOUD COVER. FRIDAY
WILL REMAIN DRY AS PRECIP WILL REMAIN ALONG THE FRONT OVER THE
CNTRL APPALACHIANS LATE FRIDAY.
FRIDAY NIGHT-SATURDAY...
LATEST MODEL GUIDANCE HAS BETTER RESOLVED THE DIFFERENCES WITH
THE LEADING SHORTWAVE FRIDAY...RESULTING IN BETTER AGREEMENT WITH
PUSHING THE FRONT OVER THE LOCAL AREA FRIDAY NIGHT. FORCING WILL
BE RATHER LIMITED AS THE TROUGH DYNAMICS WILL REMAIN WELL
NORTH...BUT SUFFICIENT MOISTURE ALONG THE FRONT WILL BE ENOUGH TO
PRODUCE SCATTERED LIGHT SHOWERS. BETTER MOISTURE AND OMEGA OVER
THE SE MAY LEAD TO BETTER DEVELOPMENT LATE FRI NIGHT...BUT WILL
ONLY LEAVE CHANCE POPS ATTM. QPF AMOUNTS WILL BE LIGHT WITH
AMOUNTS GENERALLY LESS THAN TWO TENTHS OF AN INCH. SEVERAL LOCALES
WILL ONLY RECEIVE A FEW HUNDREDTHS OF AN INCH. THE BIGGEST IMPACT
WILL NOT BE THE LIGHT PRECIP...BUT INSTEAD THE COLD AIR THAT WILL
ACCOMPANY THE FRONT. HIGHS WILL LIKELY BE REACHED SAT MORNING
(MID-UPPER 50S)...BEFORE TEMPS FALL DURING THE DAY SATURDAY. BY
6PM SAT...TEMPS ARE FORECAST TO BE IN THE LOW-MID 40S UNDER
RAPIDLY CLEARING SKIES. THE STRONGEST CAA WILL ARRIVE SAT NIGHT AS
NW WINDS INCREASE WITH GUSTS UP TO 25-30 MPH.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CDFNT MOVES WELL OFF THE CST SAT NGT...AND ANY PCPN ASSOCIATED W/IT
XPCD TO END AFT MDNGT. DRY...MUCH COLDER AND WINDY WX XPCD SUN. SFC
HI PRES REACHES/BUILDS OVR THE RGN SUN NGT INTO MON. H85 TEMPS FCST
TO FALL TO OR BLO -10 DEGS C SUN NGT...THEN BE SLO TO RECOVER ON
MON. LO PRES TO SLO DEVELOP INVOF SRN PLAINS/WRN GULF STATES ERY
NEXT WEEK...THEN TRACK ENE TO THE MDATLC/SE STATES BY WED. WILL
BRING INCRSG CLDNS/POPS FM THE SW ON TUE. RIGHT NOW...HIGHEST PROB
FOR PCPN IS TUE NGT INTO WED AS SFC LO PRES TRACKS OFF THE CST OF
THE CAROLINAS.
LO TEMPS SAT NGT FM THE M20S W TO L30S AT THE CST. HI TEMPS SUN FM
THE M30S W AND N...TO ARND 40F SE (W/ WIND CHILLS IN THE 20S). LO
TEMPS SUN NGT FM ARND 20F INLAND TO U20S/ARND 30F AT THE CST. HI
TEMPS MON IN THE L/M40S. MODERATION CONTS MON NGT THROUGH TUE. LO
TEMPS MON NGT FM ARND 30F INLAND TO THE U30S NR THE CST...HI TEMPS
TUE FM THE M40S W TO L50S SE. HI TEMPS WED FM THE L40S WELL INLAND
TO L50S AT THE CST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
STRONG HIGH PRESSURE (NEARLY 1040MB) WILL BE SLOW TO RETREAT TODAY.
MEANWHILE...MOISTURE WILL INCREASE FROM THE S RESULTING IN
WIDESPREAD OVC CIGS. NAM/RUC HAVE BACKED-OFF FROM EARLIER
PESSIMISTIC FORECASTS WITH RESPECT TO CIGS. WILL CONTINUE WITH PREVAILING
CIGS FALLING TO 4K FT...WITH PERIODIC MVFR CIGS PRIMARILY AT
RIC/PHF. A LIGHT NE WIND SHOULD PREVAIL TODAY...BEFORE SHIFTING TO
SE TONIGHT.
HIGH PRESSURE SLOWLY SETTLES SSE THROUGH FRIDAY AS A STRONG COLD
FRONT APPROACHES FROM THE NW. A FEW -SHRA ARE POSSIBLE WITH THE
FRONTAL PASSAGE FRIDAY NIGHT/EARLY SATURDAY. A SECONDARY COLD FRONT
SWINGS THROUGH THE REGION SATURDAY NIGHT FOLLOWED BY A GUSTY NW WIND
SUNDAY. WIND SPEEDS ARE EXPECTED TO REACH 15-20KT...WITH GUSTS TO
25-30KT.
&&
.MARINE...
HIGH PRESSURE BUILDS ACROSS NEW ENGLAND THIS MORNING...BEFORE
SETTLING OFF OF CAPE COD AND GRADUALLY WEAKENING THIS AFTERNOON. THE
SURFACE PRESSURE GRADIENT SLACKENS ACROSS THE AREA ALLOWING THE
CURRENT E/NE WIND TO CONTINUE ITS DIMINISHING TREND. SCAS REMAIN IN
PLACE FOR WAVES/SEAS FOR THE MOUTH OF BAY THROUGH 12Z...OCEAN FROM
CAPE CHARLES TO VA/NC BORDER THROUGH 15Z...AND OCEAN OFF THE
CURRITUCK OUTER BANKS THROUGH 17Z. HIGH PRESSURE CONTINUES TO SINK S
AND WEAKEN OFF THE MID ATLANTIC AND SOUTHEAST COASTS TONIGHT THROUGH
FRIDAY. MEANWHILE...LOW PRESSURE TRACKS THROUGH THE SAINT LAWRENCE
VALLEY ALLOWING THE WIND TO SHIFT TO SW. THIS LOW PRESSURE SYSTEM
PULLS A COLD FRONT ACROSS THE MID ATLANTIC COAST FRIDAY
NIGHT...FOLLOWED BY A SHALLOW CAA SURGE. MINIMAL SCA CONDITIONS ARE
POSSIBLE FOR THE NON-OCEAN ZONES LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING. A SECONDARY COLD FRONT ARRIVES SATURDAY EVENING...FOLLOWED
BY A 24-36HR STRONG CAA NW SURGE. THERE IS A HIGH LIKELIHOOD FOR
HIGH-END SCA CONDITIONS SATURDAY NIGHT THROUGH SUNDAY
EVENING...ALONG WITH THE POTENTIAL FOR GALE FORCE WIND (MAINLY IN
GUSTS). A GRADUAL IMPROVEMENT IS EXPECTED MONDAY INTO TUESDAY. THERE
IS A POTENTIAL FOR A MODERATE TO STRONG NNE WIND BY THE MIDDLE OF
NEXT WEEK AS LOW PRESSURE DEEPENS AND TRACKS OFF THE SOUTHEAST COAST.
&&
.EQUIPMENT...
THE KAKQ RADAR WILL BE DOWN THROUGH AT LEAST TUESDAY, NOVEMBER 26TH
FOR RADOME REPAIRS. SEE THE PUBLIC INFORMATION STATEMENT (PNSAKQ)
FOR ADDITIONAL DETAILS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ634.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ656-
658.
&&
$$
SYNOPSIS...BMD/SAM
NEAR TERM...SAM
SHORT TERM...SAM
LONG TERM...ALB
AVIATION...AJZ
MARINE...AJZ
EQUIPMENT...AKQ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
921 AM EST THU NOV 21 2013
.SYNOPSIS...
A COASTAL TROUGH WILL BRING PERIODS OF ATLANTIC CLOUD COVER ONSHORE
THROUGH FRIDAY. A COLD FRONT WILL CROSS THE AREA LATE SATURDAY
FOLLOWED BY A BRIEF PERIOD OF VERY COLD AIR. A SIGNIFICANT RAIN
EVENT IS BECOMING MORE LIKELY TOWARD THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...EAST TO NORTHEAST LOW-LEVEL FLOW WILL
PROVIDE SOME ATLANTIC MOISTURE WHILE WESTERLY WINDS ALOFT SPREAD A
VARIETY OF MID AND HIGH CLOUDS INTO THE REGION. REGARDLESS...ENOUGH
BREAKS IN THE CLOUDS THIS MORNING TO ALLOW FOR A RAPID WARM-UP...
ESPECIALLY ACROSS COASTAL SOUTHEAST NC WHERE TEMPS ARE ALREADY IN
THE MID TO UPPER 50S. COOLER TEMPERATURES (LOWER 50S) PREVAIL ACROSS
REMAINING AREAS...AND THE MODELS CONTINUE TO VARY SIGNIFICANTLY WITH
MAX TEMPS THIS AFTERNOON. PLAN TO LOWER TEMPS WHERE THE CLOUD
COVER IS EXPECTED TO HAVE THE MOST IMPACT WHILE NUDGING THEM UPWARDS
WHERE THE BIGGEST BREAKS ARE ANTICIPATED. OVERALL...A TRICKY TEMP
FORECAST TODAY GIVEN THE RESIDUAL WEDGE...VARYING CLOUD COVER... AND
LOWER MID-LATE NOVEMBER SUN ANGLE. WIDELY SCATTERED SHOWER ACTIVITY
ASSOCIATED WITH THE WEAK TROUGH WILL PRIMARILY REMAIN OVER THE WATER
THROUGH MUCH OF THE DAY...THOUGH A COUPLE OF THEM MAY MAKE IT TO THE
COAST LATER IN THE DAY.
PREVIOUS DISCUSSION...
DRY RIDGING AT 700 AND 500 MILLIBARS USUALLY IMPLIES BENIGN WEATHER
DOWN HERE AT THE SURFACE. NOT SO THIS TIME AS A TIGHT PRESSURE
GRADIENT AROUND THE SOUTHERN PERIPHERY OF 1038 MB HIGH PRESSURE OVER
NEW ENGLAND...PLUS A WEAK COASTAL TROUGH OUT NEAR THE GULF STREAM
ARE ADVECTING ATLANTIC MOISTURE ONSHORE. THIS MOISTURE EXTENDS
VERTICALLY TO AROUND 8000 FEET AT WHICH POINT A SIGNIFICANT LAYER OF
DRY AIR EXISTS WITHIN THE WESTERLY FLOW ALOFT.
AS WAS TRUE ON THE 00Z MODEL RUNS...THERE ARE STILL UNANSWERED BASIC
QUESTIONS CONCERNING TODAY`S FORECAST USING THE 06Z RUNS. THE AMOUNT
OF LOW CLOUD COVER THAT REMAINS INTO THE AFTERNOON WILL LARGELY
DETERMINE OUR TEMPERATURES. ANY ISENTROPIC LIFT IS SITUATED VERY LOW
IN THE ATMOSPHERE AND BECOMES QUITE WEAK BY AFTERNOON. THERE IS
NEARLY A TEN-DEGREE DIFFERENCE BETWEEN THE 00Z NAM AND GFS INLAND...
AND NO CLEAR SIGNAL WHICH MODEL...IF EITHER...IS RIGHT. THE WEDGE
PATTERN TO THE PRESSURE AND WIND FIELDS ACROSS THE CAROLINAS IMPLIES
THE COOLER GFS MAY BE THE WAY TO GO...ALTHOUGH I WOULD FEEL MORE
CONFIDENT IN THIS DECISION IF THERE WERE RAIN AND/OR WIDESPREAD LOW
STRATUS ACROSS CENTRAL NORTH CAROLINA TO HELP OFFSET INSOLATION. THE
06Z RUNS ESSENTIALLY MIRRORED THEIR 00Z COUNTERPARTS...BUT THE
LATEST RUC AND HRRR HAVE COME FIRMLY INTO LINE WITH THE WARMER 00Z
AND 06Z NAM.
THE AIRMASS IS MODIFYING QUICKLY OVERHEAD WITH WARM ADVECTION IN THE
800-950 MB LAYER ADDING A GOOD 2-3 DEGREES C THROUGH THIS EVENING.
ALONG THIS COAST THIS SHOULD YIELD HIGHS IN THE UPPER 60S...PERHAPS
EVEN SQUEAKING OUT A 70 DEGREE READING HERE AND THERE AWAY FROM THE
BEACHES. FARTHER INLAND IS WHERE LARGER QUESTIONS REMAIN. WITH LOW
CONFIDENCE I AM FORECASTING HIGHS IN THE 62-64 RANGE ALONG THE I-95
CORRIDOR...60-61 FOR BENNETTSVILLE AND DARLINGTON...AND 64-67 FROM
ELIZABETHTOWN AND WHITEVILLE THROUGH MARION...LAKE CITY AND
KINGSTREE.
ALTHOUGH RADAR SHOWS A BAND OF SHOWERS ALONG THE WESTERN EDGE OF THE
GULF STREAM...PROBABILITIES OF MEASURABLE RAIN ARE LOW TODAY GIVEN
POOR ISENTROPIC LIFT SHOWN ON ANY MODEL. LINEAR EXTRAPOLATION OF THE
SHOWERS SHOULD HAVE ALREADY PUSHED THEM ONSHORE HOURS AGO...
INDICATING LOCAL ENVIRONMENTAL CONDITIONS OUT AT THE EDGE OF THE
GULF STREAM ARE PROBABLY KEY TO SUSTAINING THIS ACTIVITY. I AM
INCLUDING A 20 POP NEAR THE COAST LATER TODAY JUST IN CASE SOMETHING
SNEAKS IN OFF THE WATER DURING THE BEST WARM ADVECTION AROUND NOON.
WIND FIELDS SHOULD WEAKEN TONIGHT AS THE HIGH OVER NEW ENGLAND
RAPIDLY WEAKENS AND SHIFTS OFFSHORE. PLENTY OF LOW LEVEL ATLANTIC
MOISTURE WILL MODERATE TEMPERATURES...AND LOWS SHOULD RANGE FROM
AROUND 50 IN LUMBERTON TO THE MID 50S AT THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE FORECAST CHALLENGE CONTINUES TO THE BE
THE WEAK FORCING AND MOISTURE ASSOCIATED WITH A COASTAL TROUGH
FRIDAY THEN THE MOISTURE WITH A LONG ADVERTISED FRONT MOVING ACROSS
LATE SATURDAY/EARLY SUNDAY. THE GUIDANCE HAS WALKED BACK MOISTURE
WITH THE COASTAL TROUGH FRIDAY AND WITH THE ERRATIC NATURE OF THESE
TYPE OF FEATURES AND VOLATILITY OF GUIDANCE...THE BEST OPTION IS TO
KEEP POPS AS THEY ARE. FOR SATURDAY I HAVE FINE TUNED POPS TO
EMPHASIZE THE AFTERNOON AND EVENING HOURS PER THE LATEST MODEL
GUIDANCE. AS FOR TEMPERATURES...THE MET NUMBERS ARE WARMER ACROSS
THE BOARD AND GENERALLY LEANED TOWARD THESE NUMBERS THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...THE EXTENDED FORECAST LOOKS TO BE VERY
ACTIVE WITH THE EMPHASIS NOW SHIFTING TO THE END OF THE PERIOD WHEN
A CUTOFF LOW OUT WEST OPENS UP AND MOVES ACROSS THE SOUTHEAST.
SUNDAY AND MONDAY ARE FAIRLY CLEAR CUT AS COLD AIR ADVECTION
DOMINATES WITH TEMPERATURES MOST LIKELY NOT GETTING OUT OF THE 40S
SUNDAY AND DEPENDING ON DECOUPLING...MONDAY MORNINGS LOWS WELL INTO
THE 20S. FOR TUESDAY AND WEDNESDAY...THE LOW TAKES SHAPE IN THE GULF
OF MEXICO WITH A RELATIVELY WEAK AND FLEETING COLD AIR WEDGE HANGING
ON. ISENTROPIC LIFT DEVELOPS IN EARNEST LATE TUESDAY. THE LOW
ATTEMPTS TO REDEVELOP ALONG THE COASTAL FRONT WEDNESDAY BUT AT LEAST
AT THIS POINT DOESN/T BECOME DOMINANT. TOUGH CALL ON MILLER A OR B
SCENARIO HOWEVER THIS FAR OUT THIS IS HAGGLING OVER DETAILS AND RAIN
WILL CONTINUE WEDNESDAY AS THE MID LEVEL SYSTEM MOVES ACROSS. WE
HAVE FAIRLY HIGH POPS FOR TUESDAY AND ESPECIALLY WEDNESDAY ALREADY
SO I ONLY INCREMENTALLY INCREASED POPS. NO CHANGES TO TEMPERATURE
FORECAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SURFACE ANALYSIS THIS MORNING SHOWS HIGH PRESSURE
WEDGING DOWN FROM NEW ENGLAND AND A COASTAL TROUGH OFFSHORE. THE
ASSOCIATED E-NE LOW LEVEL FLOW IS ADVECTING PLENTY OF LOW/MID LEVEL
MOISTURE OVER THE CAROLINAS. EXPECT VFR CIGS 5-8KFT TO PREVAIL TODAY
WITH FEW/SCT MVFR CLOUDS DURING THE DAY. FCST SOUNDINGS AND GUIDANCE
INDICATE POCKETS OF MVFR CIGS MAY DEVELOP THIS MORNING...SO HAVE
INCLUDED TEMPO GROUPS TO ACCOUNT FOR THIS. THE BEST CHANCES FOR MVFR
WILL BE AT OUR SOUTHERN TERMINALS...AS MORE WIDESPREAD MVFR IS BEING
REPORTED DOWN TOWARD KCHS. NORTHEAST WINDS 6-10 KTS TODAY WILL
BECOME AOB 5 KTS AFTER 00Z FRIDAY. ABUNDANT LOW LEVEL MOISTURE MAY
SUPPORT FOG/STRATUS DEVELOPMENT OVERNIGHT...ESPECIALLY INLAND. WILL
INCLUDE MVFR VSBYS AFTER 06Z FOR ALL TAF SITES.
EXTENDED OUTLOOK...CHANCE OF SHOWERS/MVFR CIGS ON SATURDAY WITH A
COLD FRONT. VFR SUNDAY AND MONDAY. EXPECT GUSTY NORTH WINDS ON
SUNDAY BEHIND THE FRONT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...BASED ON THE MARINE OBSERVATIONS IT IS
IMPLIED THAT SMALL CRAFT CONDITIONS LIKELY CONTINUE ACROSS THE OUTER
COASTAL WATERS...EXCEPT FROM MURRELLS INLET TO LITTLE RIVER INLET.
CONDITIONS WILL SLOWLY IMPROVE AS THE WEAKENING COASTAL TROUGH
SHIFTS FARTHER WEST. MAY NEED TO REFINE THE ENDING TIME OF THE
REMAINING SMALL CRAFT AREAS BASED ON TRENDS HEADING INTO THIS
AFTERNOON...BUT UNTIL THEN CHOPPY SEAS WILL CONTINUE WITH THE
NORTHEAST TO EAST FETCH THAT HAS BEEN IN PLACE. WIDELY SCATTERED
SHOWERS WILL PRIMARILY AFFECT THE OUTER COASTAL WATERS THROUGH MOST
OF THE DAY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...THE PROLONGED NORTHEAST FLOW WILL BE ABATING
AT THE BEGINNING OF THE PERIOD AS SURFACE HIGH PRESSURE WEAKENS AND
ELONGATES WEST TO EAST. A WEAK SOUTH TO SOUTHWEST TO EVENTUALLY
WESTERLY FLOW WILL THEN TAKE PLACE. SPEEDS WILL REMAIN TEPID AROUND
TEN KNOTS. SATURDAY EVENING THE FRONT WILL CROSS THE WATERS AND BY
0600 UTC SUNDAY ELEMENTS WILL BE VERY DIFFERENT FROM JUST A FEW
HOURS EARLIER AS NORTH WINDS OF 25-30 KNOTS DEVELOP. A BRIEF GALE
WARNING CANNOT BE RULED OUT. SEAS OF COURSE WILL BE BENIGN FOR MOST
OF THE PERIOD BUT RAMPING UP QUICKLY ESPECIALLY ACROSS THE OUTER
WATERS LATE WITH THE RAPID INCREASE IN WIND SPEEDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...POTENT COLD AIR ADVECTION WILL DOMINATE THE
COASTAL WATERS SUNDAY WITH NORTH WINDS OF 20-25 KNOTS. WITH THE
PROGRESSIVE PATTERN...THE SURFACE HIGH WILL QUICKLY MOVE ACROSS THE
WATERS MONDAY WITH NORTHEAST WINDS DOWN TO 10-15 KNOTS AND EVEN LESS
BY THE END OF THE DAY. SEAS WILL BE HIGH SUNDAY BUT CONFINED TO THE
OUTER WATERS CONSIDERING THE FETCH WITH A SMALL CRAFT ADVISORY
LIKELY CONTINUING. MONDAY SEAS DROP TO 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
AMZ250-252-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
659 AM EST THU NOV 21 2013
.SYNOPSIS...
A WEAK TROUGH WILL AFFECT THE NORTH CAROLINA COAST TODAY. STRONG HIGH
PRESSURE WILL LINGER NORTH AND EAST OF THE AREA TONIGHT AND FRIDAY.
A STRONG COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT AND MOVE
OFFSHORE SATURDAY AND SATURDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD
IN FROM THE NORTHWEST SUNDAY AND MONDAY. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST TUESDAY AND CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 650 AM THURSDAY...A WEAK INVERTED TROUGH CONTINUES TO
PRODUCE SHOWERS FROM THE SOUTHERN COASTAL SECTION AND THEN NORTH
ALONG THE HIGHWAY 17 CORRIDOR. PER THE LATEST RAP AND HRR-R 4 KM
MODEL...THESE SHOWERS WILL CONTINUE INTO THE AFTERNOON. AMOUNTS
WILL BE LIGHT...LARGELY ONE-TENTH OF AN INCH OR LESS. HAVE KEPT
POPS IN THE 20 TO 30 PCT RANGE GIVEN THE LIGHT NATURE OF THE
SHOWERS. HAVE ALSO BEEFED UP CLOUD COVER ACROSS THE REGION FOR THE
REMAIN OF THE DAY...AND ACCORDINGLY HAVE LOWERED MAXIMUM
TEMPERATURES A COUPLE OF DEGREES AS WELL...GIVEN THE CLOUDINESS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
AS OF 310 AM THURSDAY...THE THREAT OF ANY PRECIPITATION SHOULD END
BY THIS EVENING...WITH SOME PARTIAL CLEARING OVERNIGHT. THE AXIS
OF THE SURFACE RIDGE WILL SETTLE OVER THE AREA TONIGHT...BUT WITH
A LIGHT ONSHORE FLOW...MINIMUM TEMPERATURES WILL RANGE IN THE
UPPER 40S TO MID 50S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 3 AM THU...00Z GFS/ECMWF IN GOOD AGREEMENT THROUGH THE END
OF THE WEEK. UPPER RIDGE OVER THE REGION BECOMES ZONAL AS POWERFUL
UPPER TROF BEGINS TO MOVE TOWARD THE SOUTHEAST...WHILE AT THE
SURFACE THE HIGH OVER THE CAROLINAS WILL MOVE SOUTHEAST. THE STRONG
COLD FRONT SWEEPS THROUGH ON SATURDAY. PREFER THE TIMING OF THE
FRONTAL PASSAGE FROM THE ECMWF AS IT MATCHES UP WELL WITH THE HPC
SOLUTION. GFS APPEARS ABOUT 6 HOURS TOO FAST. THE FRONT WILL ENTER
THE NORTHERN COUNTIES AROUND 12Z AND WILL BE SOUTH OF THE ENTIRE
AREA BY 00Z SUNDAY. GOOD LIFT AND CONVERGENCE ALONG THE FRONT.
HAVE KEPT POPS AT 40%. MUCH COLDER AND DRIER AIRMASS QUICKLY
OVERSPREADS THE REGION BEHIND THE FRONT. LIKE THE LAST ARCTIC
BLAST NOT TOO LONG AGO IT APPEARS THIS ONE WILL NOT BE AROUND FOR
VERY LONG EITHER. THE SURFACE RIDGE OVER THE NORTHERN PLAINS
SATURDAY WILL BE OVER THE CAROLINAS MONDAY THEN OFF THE COAST
TUESDAY...SO COLD NORTHERLY FLOW SATURDAY WILL BECOME SOUTHERLY ON
TUESDAY. RESULTING HIGHS WILL BE ONLY IN THE LOWER TO MID 40S
SUNDAY BUT WARMING QUICKLY TO THE MID AND UPPER 50S ON TUESDAY.
MODELS NOT HANDLING VERY WELL THE SYSTEM HEADING OUT OF THE GULF
NEXT WEEK. LOOKS LIKE THE ECMWF HAS A SLIGHT EDGE AT THE SURFACE
WHEN COMPARED TO THE HPC SOLUTION. HAVE RAISED POPS TO 40-50
PERCENT TUESDAY AND 50 PERCENT FOR WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 655 AM THU...PATCHY SHOWERS ARE AFFECTING EASTERN PORTIONS
OF THE CWA...INCLUDING THE KEWN AIRPORT. SOME LIGHT RAIN MAY ALSO
IMPACT THE OTHER THREE TAF SITES. ANY CEILINGS SHOULD REMAIN AOA
3000 FEET AS AREA OF BROKEN MID AND HIGH CLOUDS WILL OVERSPREAD
THE AREA FROM THE WEST AS THE DAY WEARS ON. SOME BREAKS IN THE
CLOUDS COUPLED WITH A LOW-LEVEL INVERSION MAY LEAD TO SOME PATCHY
FOG LATE TONIGHT AND HAVE INCLUDED MVFR LEVEL FOG AT ALL TAF SITES
LATER TONIGHT/EARLY FRIDAY MORNING.
LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...VFR THROUGH FRIDAY. THE EXCEPTION WILL BE A FEW
HOURS EITHER SIDE OF 12Z FRIDAY AND SATURDAY WITH THE POSSIBILITY
OF SOME VFR/MVFR FOG. SCATTERED SHOWERS EXPECTED ON SATURDAY AHEAD
OF A STRONG COLD FRONT WITH MVFR CIGS/VSBYS. THE FRONT WILL PASS
THROUGH FROM THE NORTH DURING THE DAY WITH WINDS RAPIDLY VEERING
FROM SOUTHWEST IN THE MORNING TO DUE NORTH BY LATE AFTERNOON. MUCH
DRIER AND COLDER AIRMASS QUICKLY OVERSPREADS THE REGION BEHIND THE
FRONT. SKIES WILL BECOME CLEAR/VFR EARLY SATURDAY EVENING. BREEZY
CONDITIONS EXPECTED SUNDAY WITH NORTH WINDS 15-25 KNOTS. SURFACE
RIDGE WILL BUILD TOWARD THE AREA MONDAY. VFR CONDITIONS CONTINUE
WITH HIGH CLOUD DECK FILTERING IN DURING THE DAY AND GRADUALLY
LOWERING ALONG WITH LIGHT AND VARIABLE WINDS.
&&
.MARINE...
.SHORT TERM /TODAY AND TONIGHT/...
AS OF 7 AM THURSDAY...NOT MUCH CHANGE TO THE MARINE CONDITIONS AT
THIS TIME. WINDS ARE GENERALLY E/NE AT 10 TO 15 KNOTS ON ALL
WATERS. SEAS REMAIN AT 6 TO 7 FEET AT ALL LOCATIONS SO NO CHANGES
TO THE CURRENT SMALL CRAFT ADVISORY STATUS. SEAS SHOULD SLOW
SUBSIDE TO 5 FEET OR LESS BY LATE TONIGHT AS EASTERLY WINDS DROP
TO 10 KNOTS OR LESS OVER MOST OF THE COASTAL WATERS AND SOUNDS.
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM THU...USED A BLEND OF THE 00Z GFS/ECMWF FOR THE MARINE
WINDS THROUGH FRIDAY NIGHT. GFS IS RUNNING AROUND 6 HOURS TOO FAST
WITH THE TIMING OF THE FRONT ON SATURDAY AND PREFER THE ECMWF. THE
SURFACE RIDGE ALONG THE EAST COAST FRIDAY WILL QUICKLY MOVE
SOUTHEAST OFF THE COAST FRIDAY NIGHT. FRIDAY APPEARS TO BE THE
BEST BOATING DAY IN THE LONG TERM PORTION OF THE FORECAST. EAST
FLOW FRIDAY MORNING WILL BECOME SOUTHERLY IN THE AFTERNOON THEN
SOUTHWEST FRIDAY NIGHT AND CONTINUING INTO SATURDAY. WINDS WILL
AVERAGE 5-10 KNOTS AND SEAS 2-4 FEET FRIDAY. WINDS AND SEAS WILL
GRADUALLY INCREASE AFTER THAT FRIDAY NIGHT INTO SATURDAY AS A
STRONG COLD FRONT APPROACHES. THE FRONT WILL ENTER THE NORTHERN
WATERS SATURDAY AROUND 12Z...MOVE THROUGH THE CENTRAL WATERS
AROUND 18Z AND WILL BE SOUTH OF THE SOUTHERN WATERS BY 00Z SUNDAY.
STRONG SMALL CRAFT CONDITIONS WILL DEVELOP QUICKLY BEHIND THE
FRONT SPREADING ACROSS THE MARINE ZONES FROM NORTH TO SOUTH
SATURDAY NIGHT. CONDITIONS WILL IMPROVE EARLY NEXT WEEK AS A
SURFACE RIDGE BUILDS INTO THE AREA WITH WINDS/SEAS DIMINISHING AS
A RESULT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 11 AM EST THIS MORNING FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...HSA
AVIATION...CTC/HSA
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
625 AM EST THU NOV 21 2013
.SYNOPSIS...
A COASTAL TROUGH WILL BRING PERIODS OF ATLANTIC CLOUD COVER ONSHORE
THROUGH FRIDAY. A COLD FRONT WILL CROSS THE AREA LATE SATURDAY
FOLLOWED BY A BRIEF PERIOD OF VERY COLD AIR. A SIGNIFICANT RAIN
EVENT IS BECOMING MORE LIKELY TOWARD THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...DRY RIDGING AT 700 AND 500 MILLIBARS USUALLY
IMPLIES BENIGN WEATHER DOWN HERE AT THE SURFACE. NOT SO THIS TIME AS
A TIGHT PRESSURE GRADIENT AROUND THE SOUTHERN PERIPHERY OF 1038 MB
HIGH PRESSURE OVER NEW ENGLAND...PLUS A WEAK COASTAL TROUGH OUT NEAR
THE GULF STREAM ARE ADVECTING ATLANTIC MOISTURE ONSHORE. THIS
MOISTURE EXTENDS VERTICALLY TO AROUND 8000 FEET AT WHICH POINT A
SIGNIFICANT LAYER OF DRY AIR EXISTS WITHIN THE WESTERLY FLOW ALOFT.
AS WAS TRUE ON THE 00Z MODEL RUNS...THERE ARE STILL UNANSWERED BASIC
QUESTIONS CONCERNING TODAY`S FORECAST USING THE 06Z RUNS. THE AMOUNT
OF LOW CLOUD COVER THAT REMAINS INTO THE AFTERNOON WILL LARGELY
DETERMINE OUR TEMPERATURES. ANY ISENTROPIC LIFT IS SITUATED VERY LOW
IN THE ATMOSPHERE AND BECOMES QUITE WEAK BY AFTERNOON. THERE IS
NEARLY A TEN-DEGREE DIFFERENCE BETWEEN THE 00Z NAM AND GFS
INLAND...AND NO CLEAR SIGNAL WHICH MODEL...IF EITHER...IS RIGHT. THE
WEDGE PATTERN TO THE PRESSURE AND WIND FIELDS ACROSS THE CAROLINAS
IMPLIES THE COOLER GFS MAY BE THE WAY TO GO...ALTHOUGH I WOULD FEEL
MORE CONFIDENT IN THIS DECISION IF THERE WERE RAIN AND/OR WIDESPREAD
LOW STRATUS ACROSS CENTRAL NORTH CAROLINA TO HELP OFFSET INSOLATION.
THE 06Z RUNS ESSENTIALLY MIRRORED THEIR 00Z COUNTERPARTS...BUT THE
LATEST RUC AND HRRR HAVE COME FIRMLY INTO LINE WITH THE WARMER 00Z
AND 06Z NAM.
THE AIRMASS IS MODIFYING QUICKLY OVERHEAD WITH WARM ADVECTION IN THE
800-950 MB LAYER ADDING A GOOD 2-3 DEGREES C THROUGH THIS EVENING.
ALONG THIS COAST THIS SHOULD YIELD HIGHS IN THE UPPER 60S...PERHAPS
EVEN SQUEAKING OUT A 70 DEGREE READING HERE AND THERE AWAY FROM THE
BEACHES. FARTHER INLAND IS WHERE LARGER QUESTIONS REMAIN. WITH LOW
CONFIDENCE I AM FORECASTING HIGHS IN THE 62-64 RANGE ALONG THE I-95
CORRIDOR...60-61 FOR BENNETTSVILLE AND DARLINGTON...AND 64-67 FROM
ELIZABETHTOWN AND WHITEVILLE THROUGH MARION...LAKE CITY AND
KINGSTREE.
ALTHOUGH RADAR SHOWS A BAND OF SHOWERS ALONG THE WESTERN EDGE OF THE
GULF STREAM...PROBABILITIES OF MEASURABLE RAIN ARE LOW TODAY GIVEN
POOR ISENTROPIC LIFT SHOWN ON ANY MODEL. LINEAR EXTRAPOLATION OF THE
SHOWERS SHOULD HAVE ALREADY PUSHED THEM ONSHORE HOURS AGO...
INDICATING LOCAL ENVIRONMENTAL CONDITIONS OUT AT THE EDGE OF THE
GULF STREAM ARE PROBABLY KEY TO SUSTAINING THIS ACTIVITY. I AM
INCLUDING A 20 POP NEAR THE COAST LATER TODAY JUST IN CASE SOMETHING
SNEAKS IN OFF THE WATER DURING THE BEST WARM ADVECTION AROUND NOON.
WIND FIELDS SHOULD WEAKEN TONIGHT AS THE HIGH OVER NEW ENGLAND
RAPIDLY WEAKENS AND SHIFTS OFFSHORE. PLENTY OF LOW LEVEL ATLANTIC
MOISTURE WILL MODERATE TEMPERATURES...AND LOWS SHOULD RANGE FROM
AROUND 50 IN LUMBERTON TO THE MID 50S AT THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE FORECAST CHALLENGE CONTINUES TO THE BE
THE WEAK FORCING AND MOISTURE ASSOCIATED WITH A COASTAL TROUGH
FRIDAY THEN THE MOISTURE WITH A LONG ADVERTISED FRONT MOVING ACROSS
LATE SATURDAY/EARLY SUNDAY. THE GUIDANCE HAS WALKED BACK MOISTURE
WITH THE COASTAL TROUGH FRIDAY AND WITH THE ERRATIC NATURE OF THESE
TYPE OF FEATURES AND VOLATILITY OF GUIDANCE...THE BEST OPTION IS TO
KEEP POPS AS THEY ARE. FOR SATURDAY I HAVE FINE TUNED POPS TO
EMPHASIZE THE AFTERNOON AND EVENING HOURS PER THE LATEST MODEL
GUIDANCE. AS FOR TEMPERATURES...THE MET NUMBERS ARE WARMER ACROSS
THE BOARD AND GENERALLY LEANED TOWARD THESE NUMBERS THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...THE EXTENDED FORECAST LOOKS TO BE VERY
ACTIVE WITH THE EMPHASIS NOW SHIFTING TO THE END OF THE PERIOD WHEN
A CUTOFF LOW OUT WEST OPENS UP AND MOVES ACROSS THE SOUTHEAST.
SUNDAY AND MONDAY ARE FAIRLY CLEAR CUT AS COLD AIR ADVECTION
DOMINATES WITH TEMPERATURES MOST LIKELY NOT GETTING OUT OF THE 40S
SUNDAY AND DEPENDING ON DECOUPLING...MONDAY MORNINGS LOWS WELL INTO
THE 20S. FOR TUESDAY AND WEDNESDAY...THE LOW TAKES SHAPE IN THE GULF
OF MEXICO WITH A RELATIVELY WEAK AND FLEETING COLD AIR WEDGE HANGING
ON. ISENTROPIC LIFT DEVELOPS IN EARNEST LATE TUESDAY. THE LOW
ATTEMPTS TO REDEVELOP ALONG THE COASTAL FRONT WEDNESDAY BUT AT LEAST
AT THIS POINT DOESN/T BECOME DOMINANT. TOUGH CALL ON MILLER A OR B
SCENARIO HOWEVER THIS FAR OUT THIS IS HAGGLING OVER DETAILS AND RAIN
WILL CONTINUE WEDNESDAY AS THE MID LEVEL SYSTEM MOVES ACROSS. WE
HAVE FAIRLY HIGH POPS FOR TUESDAY AND ESPECIALLY WEDNESDAY ALREADY
SO I ONLY INCREMENTALLY INCREASED POPS. NO CHANGES TO TEMPERATURE
FORECAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SURFACE ANALYSIS THIS MORNING SHOWS HIGH PRESSURE
WEDGING DOWN FROM NEW ENGLAND AND A COASTAL TROUGH OFFSHORE. THE
ASSOCIATED E-NE LOW LEVEL FLOW IS ADVECTING PLENTY OF LOW/MID LEVEL
MOISTURE OVER THE CAROLINAS. EXPECT VFR CIGS 5-8KFT TO PREVAIL TODAY
WITH FEW/SCT MVFR CLOUDS DURING THE DAY. FCST SOUNDINGS AND GUIDANCE
INDICATE POCKETS OF MVFR CIGS MAY DEVELOP THIS MORNING...SO HAVE
INCLUDED TEMPO GROUPS TO ACCOUNT FOR THIS. THE BEST CHANCES FOR MVFR
WILL BE AT OUR SOUTHERN TERMINALS...AS MORE WIDESPREAD MVFR IS BEING
REPORTED DOWN TOWARD KCHS. NORTHEAST WINDS 6-10 KTS TODAY WILL
BECOME AOB 5 KTS AFTER 00Z FRIDAY. ABUNDANT LOW LEVEL MOISTURE MAY
SUPPORT FOG/STRATUS DEVELOPMENT OVERNIGHT...ESPECIALLY INLAND. WILL
INCLUDE MVFR VSBYS AFTER 06Z FOR ALL TAF SITES.
EXTENDED OUTLOOK...CHANCE OF SHOWERS/MVFR CIGS ON SATURDAY WITH A
COLD FRONT. VFR SUNDAY AND MONDAY. EXPECT GUSTY NORTH WINDS ON
SUNDAY BEHIND THE FRONT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...THE PRESSURE GRADIENT ALONG THE SOUTHERN
PERIPHERY OF STRONG HIGH PRESSURE OVER NEW ENGLAND IS FUELING OUR
STRONG NORTHEAST WINDS THIS MORNING. A WEAK COASTAL TROUGH OUT NEAR
THE GULF STREAM IS HELPING MAINTAIN NORTHEASTERLY WINDS RATHER THAN
EASTERLY. WIND SPEEDS WILL GRADUALLY DIMINISH...BUT IT WILL TAKE
TIME FOR MARINE CONDITIONS TO SIGNIFICANTLY IMPROVE. SMALL CRAFT
ADVISORY CONDITIONS (BOTH WINDS AND SEAS) SHOULD CONTINUE THROUGH
LATE THIS EVENING FOR ALL BUT THE PROTECTED PORTION OF LONG BAY
WHERE LOWER WINDS AND SEAS SHOULD ALLOW THE ADVISORY TO BE DROPPED
LATER THIS MORNING.
BY TONIGHT THE STRONG HIGH OVER NEW ENGLAND SHOULD RAPIDLY WEAKEN AS
IT PUSHES EAST INTO THE ATLANTIC. THIS WILL RESULT IN A TREND TOWARD
LIGHTER WIND SPEEDS LOCALLY...AND EVENTUALLY LOWER SEA HEIGHTS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...THE PROLONGED NORTHEAST FLOW WILL BE ABATING
AT THE BEGINNING OF THE PERIOD AS SURFACE HIGH PRESSURE WEAKENS AND
ELONGATES WEST TO EAST. A WEAK SOUTH TO SOUTHWEST TO EVENTUALLY
WESTERLY FLOW WILL THEN TAKE PLACE. SPEEDS WILL REMAIN TEPID AROUND
TEN KNOTS. SATURDAY EVENING THE FRONT WILL CROSS THE WATERS AND BY
0600 UTC SUNDAY ELEMENTS WILL BE VERY DIFFERENT FROM JUST A FEW
HOURS EARLIER AS NORTH WINDS OF 25-30 KNOTS DEVELOP. A BRIEF GALE
WARNING CANNOT BE RULED OUT. SEAS OF COURSE WILL BE BENIGN FOR MOST
OF THE PERIOD BUT RAMPING UP QUICKLY ESPECIALLY ACROSS THE OUTER
WATERS LATE WITH THE RAPID INCREASE IN WIND SPEEDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...POTENT COLD AIR ADVECTION WILL DOMINATE THE
COASTAL WATERS SUNDAY WITH NORTH WINDS OF 20-25 KNOTS. WITH THE
PROGRESSIVE PATTERN...THE SURFACE HIGH WILL QUICKLY MOVE ACROSS THE
WATERS MONDAY WITH NORTHEAST WINDS DOWN TO 10-15 KNOTS AND EVEN LESS
BY THE END OF THE DAY. SEAS WILL BE HIGH SUNDAY BUT CONFINED TO THE
OUTER WATERS CONSIDERING THE FETCH WITH A SMALL CRAFT ADVISORY
LIKELY CONTINUING. MONDAY SEAS DROP TO 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
AMZ250-252-256.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR AMZ254.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NORMAN OK
956 AM CST THU NOV 21 2013
.UPDATE...
COLD FRONT IS MOVING QUICKLY AND IS WELL AHEAD OF SCHEDULE. NONE
OF THE SYNOPTIC SCALE MODELS HAVE DONE WELL WITH THIS TIMING AND
THE TIMING IS EVEN QUICKER THAN THE ACCELERATED TIMING THAT THE
MIDNIGHT SHIFT WORKED IN. HAVE UPDATED THE FORECAST WITH AN EVEN
FASTER ARRIVAL OF THE COLD FRONT CLOSER TO WHAT THE RAP IS
FORECASTING.
&&
.PREV DISCUSSION... /ISSUED 625 AM CST THU NOV 21 2013/
DISCUSSION...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
HIGH CONFIDENCE IN MVFR TO IFR CONDITIONS THROUGH THE ENTIRE
FORECAST PERIOD. AN AREA OF SHRA/TSRA WILL CONTINUE TO MOVE ACROSS
NORTHERN OK NEAR PNC THROUGH LATE THIS MORNING. A STRONG COLD
FRONT WILL THEN MOVE INTO WWR/GAG AROUND 14-15Z RESULTING IN A
WIND SHIFT FROM THE NORTH. SUSTAINED WINDS AROUND 25 TO 30 KT...LOW
CIGS...AND EVENTUALLY FZRA/DZ WILL ACCOMPANY THIS ARCTIC FRONT
THROUGH 12Z TOMORROW.
PREV DISCUSSION... /ISSUED 529 AM CST THU NOV 21 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE ACROSS PORTIONS OF NORTHERN OK
EARLY THIS MORNING WITHIN ZONE OF ISENTROPIC ASCENT AHEAD OF A MID
LEVEL SHORTWAVE TROUGH. EXPECT MOST OF THIS ACTIVITY TO SHIFT OUT
OF OUR FA AROUND 15-18Z. AROUND 430 AM...THE HIGHLY ANTICIPATED
COLD FRONT WAS MOVING INTO SW KS. THIS IS A BIT FASTER THAN MOST
OF THE MODELS SUGGESTED YESTERDAY...WHICH OFTEN OCCURS WITH ARCTIC
AIRMASSES. DECIDED TO SPEED UP THE FRONT CLOSER TO THE FASTEST
SOLUTIONS...THE CANADIAN AND HRRR. EXPECT THE FRONT FROM NEAR PNC
TO KINGFISHER AND ELK CITY AROUND NOON. TEMPS WILL HAVE A CHANCE
TO CLIMB AHEAD OF IT WITHIN SW 850 FLOW ACROSS CENTRAL/SW OK AND
WESTERN NORTH TEXAS FROM THE MID 60S TO UPPER 70S
RESPECTIVELY...BUT WILL QUICKLY DROP BEHIND IT. STILL EXPECT
ENOUGH INSTABILITY AHEAD OF THE FRONT OVER WESTERN NORTH TEXAS AND
SOUTHERN OK FOR SOME STRONGER STORMS TO DEVELOP LATE THIS
AFTERNOON AND EARLY THIS EVENING. THE PRESSURE GRADIENT WITH THE
FRONT WILL ALSO SUPPORT HIGH ENOUGH WINDS FOR AN ADVISORY THROUGH
LATE TONIGHT. THE MAIN CONCERN...HOWEVER...WILL BE POST-FRONTAL
FREEZING RAIN AND DRIZZLE EARLY TOMORROW MORNING.
CONFIDENCE IS HIGH ENOUGH THAT AT LEAST SOME ICING WILL OCCUR ON
ELEVATED SURFACES AS PERSISTENT LIGHT FREEZING RAIN/DRIZZLE
DEVELOPS BEHIND THE FRONT WITH ENOUGH LOW TO MID LEVEL MOISTURE
PRESENT....AND SOME SUBTLE ISENTROPIC ASCENT NEAR SC/S/SW OK. THE
NAM12 IS STILL THE MOST AGGRESSIVE SOLUTION WITH REGARDS TO
QPF...KEEPING SOUTHERLY TO EASTERLY FLOW PRESENT ON THE 290-300K
SURFACES THROUGH FRIDAY MORNING AND THUS MORE SIGNFICANT
ISENTROPIC ASCENT. IT CONTINUES TO BE THE OUTLIER THOUGH AND AM
NOT VERY CONFIDENT IN IT VERIFYING. ALSO HAVE INCLUDED SNOW AND
SLEET FOR W/N/NW OK. THIS IS WHERE A WEAK MID LEVEL SHORTWAVE
TROUGH WILL ROUND A SHORTWAVE RIDGE THROUGH LATE FRIDAY
MORNING...ENOUGH MOISTURE WILL BE PRESENT THROUGH THE DENDRITIC
ZONE...AND DIV ALOFT WILL ASSIST IN LIFT. EXPECT MAYBE AN INCH
ACROSS THE NW ZONES FRIDAY. FREEZING DRIZZLE MAY LINGER MAINLY
ALONG AND SOUTH OF I40 THROUGH LATE FRI NIGHT...BUT DO NOT EXPECT
MUCH ICE ACCUMULATION WITH THIS AS MUCH DRIER LOW-MID LEVEL AIR
QUICKLY DIVES SOUTH.
THE NEXT CHALLENGE IN THE FORECAST WILL BE THE PROGRESSION OF A
CLOSED LOW MOVING OVER THE SW CONUS SUN. SOLUTIONS SUGGEST AT
LEAST A NORTHERN BRANCH OF THE LOW MOVING CLOSER TO OUR NECK OF
THE WOODS WITH THIS SYSTEM. CONFIDENCE IS INCREASING THAT
SNOW/SLEET AND RAIN WILL ACCOMPANY THIS FEATURE SUNDAY THROUGH AT
LEAST MONDAY. WILL CONTINUE TO INCREASE POPS AND MENTION
SNOW...ALTHOUGH AMOUNTS ARE STILL UNCLEAR.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 29 34 29 / 40 70 50 30
HOBART OK 70 27 32 27 / 30 30 40 20
WICHITA FALLS TX 76 32 34 30 / 80 60 60 40
GAGE OK 55 23 27 24 / 20 60 30 20
PONCA CITY OK 57 28 34 29 / 70 40 40 20
DURANT OK 67 41 41 36 / 50 80 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR OKZ004>030-033>038.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
OKZ014>017-021>025-027>029-033>038-044.
TX...WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
TXZ083>086.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
525 AM CST THU NOV 21 2013
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 347 AM CST THU NOV 21 2013/
DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
06Z TAF CYCLE
STRATUS SEEMS TO STILL HAVING TROUBLE MAKING IT TO TUP...BUT STILL
FEEL LIKE IT WILL MAKE IN BY SUNRISE. OTHERWISE VFR AT THE OTHER
SITES THROUGH MOST OF THE DAY.
LIGHT SHOWERS WILL BEGIN TO APPROACH JBR DURING THE MID
AFTERNOON...MEM SLIGHTLY BEFORE SUNSET...MKL JUST AFTER
SUNSET...AND TUP BY MIDNIGHT...STEADY RAIN WILL FOLLOW BY 3-4
HOURS. CIGS WILL LOWER TO MVFR LEVELS AS THE STEADIER RAIN
BEGINS...AND LIKELY TO IFR LEVELS BY MIDNIGHT AT ALL SITES.
WINDS SOUTHEAST 5 TO 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 57 60 42 / 30 70 100 70
MKL 66 54 59 41 / 20 50 100 60
JBR 62 52 54 37 / 40 100 90 40
TUP 68 55 65 47 / 10 20 70 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
347 AM CST THU NOV 21 2013
.DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
06Z TAF CYCLE
SAME FORECAST THINKING THIS TAF PERIOD. MVFR CIGS STILL ADVANCING
NORTHWEST ACROSS ALABAMA WILL HAVE A SLIGHT DELAY IN REACHING TUP.
OTHERWISE VFR AT THE OTHER SITES. BY NOON LIGHT SHOWERS WILL BEGIN
TO AFFECT JBR...WITH ACTIVITY SLOWLY WORKING IT`S WAY SOUTH INTO MEM
AND MKL. LATER IN THE PERIOD CIGS WILL DEVELOP NEAR THE IFR/MVFR
THRESHOLD AT JBR AS A COLD FRONT PUSHES IN...OTHERWISE VFR CIGS
WILL CONTINUE ELSEWHERE THRU 22/06Z. THOUGH NOT LONG AFTER THIS
TIME FRAME CIGS AND VSBY WILL START DETERIORATING AT MEM AND MKL.
WINDS WILL BE SOUTHEAST THROUGH SOUTH AT MAINLY 5 TO 10 KTS.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 57 60 42 / 30 70 100 70
MKL 66 54 59 41 / 20 50 100 60
JBR 62 52 54 37 / 40 100 90 40
TUP 68 55 65 47 / 10 20 70 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
549 AM CST THU NOV 21 2013
.AVIATION...
LOW STRATUS AND LIGHT FOG ARE EXPECTED TO HANG ON IN THE VICINITY
OF KLBB THROUGH 14 OR 15 UTC. OTHERWISE....VFR CONDITIONS ARE
EXPECTED AT BOTH TERMINALS WITH WESTERLY WINDS THROUGH MIDDAY.
THEN...A STRONG COLD FRONT WILL SWEEP THROUGH THE AREA...BRINGING A
WIND SHIFT TO THE NORTH...PERHAPS SOME BLOWING DUST ALONG THE FRONT...AND
SUSTAINED WIND SPEEDS RAMPING UP TO ABOUT 25 KTS BY 23 UTC. LOW
STRATUS IS EXPECTED TO FILL BACK IN TONIGHT WITH A RETURN TO IFR
CONDITIONS AND THERE WILL ALSO BE A CHANCE OF DRIZZLE...FREEZING
DRIZZLE AND SLEET OVERNIGHT...WITH VERY LIGHT ACCUMULATIONS.
&&
.PREV DISCUSSION... /ISSUED 409 AM CST THU NOV 21 2013/
SHORT TERM...
A STRONG COLD FRONT WAS BARRELING SOUTH THIS MORNING THROUGH THE
HIGH PLAINS. AT 3 AM CST THE LEADING EDGE OF THE FRONT WAS LOCATED
NEAR PUEBLO COLORADO TO GREAT BEND KANSAS. NORTHERLY WINDS OF 25 TO
35 MPH WERE BLOWING BEHIND THE FRONT WITH 6 TO 8 MB/6 HR PRESSURE
RISES AND TEMPERATURES WERE QUICKLY DROPPING INTO THE SINGLE DIGITS
ACROSS MUCH OF WYOMING. THE FRONT/S ADVANCE WAS A COUPLE HRS AHEAD OF
NAM AND GFS GUIDANCE...NOT UNUSUAL...WHILE THE HRRR AND RAP
SHORT-RANGE PROGS WERE MORE IN LINE WITH THE FRONT/S ACTUAL
PROGRESS. THE RAP SUGGESTS A WEAK NW-N WIND SHIFT WILL WORK THROUGH
THE CWFA THIS MORNING. THIS SHOULD HELP SCOUR OUT THE LOW STRATUS AND
FOG FROM NORTH TO SOUTH EARLY TO MID MORNING. THE ACTUAL FRONT COULD
BE ON THE DOORSTEP OF OUR NORTHERN COUNTIES BY ABOUT NOON...AND
CLEAR OUR SRN COUNTIES BY 5 PM OR SO. HIGH TEMPERATURES MAY BE
REACHED AROUND NOON ACROSS THE NORTH...WITH TEMPS FALLING IN THE
AFTERNOON...THEN FALLING QUICKLY FOR ALL AREAS IN THE EVENING AS THE
CAA REALLY TAKES HOLD. WE/VE COOLED TEMPS DOWN QUITE A BIT ACROSS
THE NORTH WHILE WE STILL EXPECT SOUTHERN ZONES TO REACH THE UPPER
60S AND LOW 70S BEFORE THE FRONT HITS.
IT APPEARS THAT THE PRE-FRONTAL WIND SHIFT AND EARLIER FROPA WILL
REALLY LIMIT T-STORM CHANCES THIS AFTERNOON AND EVENING...LIKELY
CONFINING THE RISK AREA TO THE EASTERN AND SOUTHERN ROLLING
PLAINS...AND WE/VE TRIMMED POPS BACK ACCORDINGLY. STRONG LIFT ALONG
THE FRONT MAY LEAD TO THE DEVELOPMENT OF A THIN LINE OF STORMS AS
SUGGESTED BY THE TTU-WRF. SOME ISOLD STRONGER CORES WITH SMALL HAIL
ARE POSSIBLE...BUT SEVERE POTENTIAL LOOKS SMALL.
THEN THE MAIN FOCUS WILL QUICKLY SHIFT TO TIMING THE CHANGEOVER TO
FREEZING PRECIP FRIDAY EVENING AND WHAT ARE THE POTENTIAL
ACCUMULATIONS. FORECAST TEMP PROFILES SHOW THAT THE SWITCH COULD
BEGIN AS EARLY AS 8 OR 9 PM ACROSS THE FAR SRN PANHANDLE WITH TEMPS
LIKELY COLD ENOUGH TO SUPPORT FROZEN PRECIP ACROSS THE ENTIRE CWA
ASIDE FROM THE SOUTHERN ROLLING PLAINS BY AROUND MIDNIGHT.
HOWEVER...FRIDAY EVENING...FORECAST SOUNDINGS DO NOT SHOW DEEP
SATURATION THUS WE ANTICIPATE THAT PRECIP INITIALLY IN THE WAKE OF
THE FRONT WILL START OUT AS DRIZZLE...THEN MIX AND SWITCH TO
FREEZING DRIZZLE. DEEPER SATURATION AND BETTER MID-LVL LIFT IS
PROGGED TO ARRIVE AFTER MIDNIGHT AND DURING THE MIDNIGHT TO 6 AM
PERIOD WE SHOULD SEE BETTER CHANCES AT SOME SLEET AND FREEZING RAIN.
SLEET WILL ALSO BE MORE LIKELY ACROSS THE COLDER AREAS OF THE NW
SPLNS AND SW TX PANHANDLE...WITH FREEZING DRIZZLE/RAIN DOMINANT IN
THE ROLLING PLAINS. FORECAST ICE/SLEET PRECIP ACCUMULATIONS LOOK
MINIMAL BEFORE MIDNIGHT...THEN INCREASE SOMEWHAT BY 6 AM...ALTHOUGH
REMAINING LIGHT. THE INITIAL ACCUMULATIONS WILL ALSO /HOPEFULLY/ BE
MITIGATED SOMEWHAT BY THE RELATIVELY WARM GROUND. THUS...AT THIS
TIME WE WILL NOT HOIST ANY WINTER WEATHER ADVISORIES...ALTHOUGH IT
IS NOT OUT OF THE QUESTION THAT ONE MAY BE NEEDED AFTER MIDNIGHT.
ALSO OF NOTE WILL BE THE GUSTY NORTH WINDS AND THE COLD WIND CHILL
TEMPS. BOTH OF THESE ARE EXPECTED TO FALL SHORT OF ADVISORY
CONDITIONS BUT WILL CONTRIBUTE TO AN OVERALL WINTRY ATMOSPHERE.
LONG TERM...
A COMPLEX FORECAST CONTINUES ON IN THE LONG TERM FORECAST THROUGH
AT LEAST EARLY NEXT WEEK. THE MAIN ISSUE WILL BE THE PRECIPITATION
TYPE AND INTENSITY. BEST CHANCES OF PRECIPITATION WILL BE
MAINTAINED DURING THE DAY ON FRIDAY WITH LESSER CHANCES ON
SATURDAY. LIFT FROM WARM AIR ADVECTION ABOVE THE COLD AIR DOME
WILL GENERALLY BE WEAK. FLOW ON THE MOIST ISENTROPIC SURFACES WILL
BE ONLY 5-10 KNOTS THROUGH THE DURATION OF THE EVENT.
HOWEVER...SOME STRONGER FLOW MAY BE POSSIBLE NEAR THE TEXAS/NEW
MEXICO STATE LINE. A MID LEVEL DRY LAYER AROUND 700MB WILL ENTER
THE AREA ON FRIDAY WHICH ADDS SOME ADDITIONAL COMPLEXITY TO THE
PRECIPITATION TYPE. AS COLD AS THE TEMPERATURE WILL BE AT THE
SURFACE...WOULD MOSTLY EXPECT EITHER FREEZING DRIZZLE OR SLEET.
THE WARM LAYER ALOFT WILL START OUT ON FRIDAY AROUND AN ASTOUNDING
7-9C BUT SLOWLY WEAKEN THROUGH THE EVENT. THE SUBFREEZING LAYER AT
THE SURFACE ON FRIDAY WILL BE AROUND 3KFT ALLOWING FOR POSSIBLE
SLEET TO DEVELOP. WITH THE LIFT GENERALLY BEING WEAK...WOULD
ANTICIPATE MORE DRIZZLE THAN RAINFALL. THERE MAY BE A SLIGHT LULL
IN PRECIPITATION ON SATURDAY WITH SOME LOW LEVEL DRYING BEFORE THE
NEXT SYSTEM AFFECTS THE REGION.
MODELS ARE COMING IN AN AGREEMENT IN MOVING A CLOSED LOW FROM WEST
TO EAST DIRECTLY OVER THE AREA INSTEAD OF EJECTING IT OUT MORE
NORTH. PRECIPITATION TYPE STILL IS AMBIGUOUS AT THIS TIME BUT
PRECIPITATION CHANCES WERE RAISED AREA WIDE WITH GROWING
CONFIDENCE IN THE TRACK OF THIS SYSTEM. THE UPPER LEVEL SYSTEM IS
FORECAST TO SWEEP OUT OF WEST TEXAS ON TUESDAY BUT WE COULD SEE
SOME TROWAL PRECIPITATION BEFORE THE SYSTEM FINALLY DEPARTS EAST.
AFTERWARDS...TEMPERATURES WILL WARM IN TIME FOR A THANKSGIVING DAY
FEAST. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 17 26 19 31 / 0 20 40 30 20
TULIA 59 19 27 23 34 / 10 20 40 30 20
PLAINVIEW 64 21 27 23 33 / 10 20 40 30 20
LEVELLAND 67 22 29 21 33 / 0 30 40 30 20
LUBBOCK 69 24 29 25 34 / 10 30 40 30 20
DENVER CITY 68 23 29 22 33 / 0 40 40 30 20
BROWNFIELD 70 24 29 24 34 / 10 40 40 30 20
CHILDRESS 65 24 31 27 38 / 20 30 40 30 20
SPUR 72 25 31 26 37 / 20 40 40 30 20
ASPERMONT 73 27 32 29 39 / 20 50 40 30 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS AMARILLO TX
523 AM CST THU NOV 21 2013
.DISCUSSION...
MULTIPLE CHANCES TO SEE A WINTRY MIX OF PRECIPITATION STILL EXPECTED
FROM TODAY THROUGH EARLY NEXT WEEK.
THE ARCTIC COLD FRONT CONTINUES TO SURGE SOUTHWARD ABOUT 3 HOURS
AHEAD OF SCHEDULE FROM YESTERDAY. THE MODELS WITH THE CLOSEST
DEPICTION OF THE FASTER FRONTAL TIMING HAS BEEN THE RUC AND THE 00Z
GFS. WITH A BLEND OF THESE TWO MODELS THE FRONT IS EXPECTED TO BE
MOSTLY THROUGH THE PANHANDLES BY NOON TODAY. THIS WILL CAUSE HIGH
TEMPERATURES TO BE COLDER THAN PREVIOUSLY ADVERTISED. THE MOST
NOTICEABLE CHANCE IN TEMPERATURE FROM YESTERDAY WILL BE IN THE
OKLAHOMA PANHANDLE WHICH REACHED INTO THE 60S BUT WILL STRUGGLE TO
REACH THE 40 DEGREE MARK TODAY.
THE FORECAST STILL SHOWS DECENT CHANCES FOR THE TEXAS AND OKLAHOMA
PANHANDLE TO SEE SOME FORM OF WINTRY PRECIPITATION BETWEEN NOW AND
SATURDAY MORNING. THE QUESTION WILL BE WHERE CAN WE GET ENOUGH
MOISTURE IN THE DENDRITIC SNOW GROWTH ZONE TO MAKE A SOLID TRANSITION
TO MOSTLY OR ALL SNOW. THE BEST AREA FOR THIS TO HAPPEN IS EXPECTED
TO BE NORTH OF A DALHART TO ELKHART LINE. THE REMAINDER OF THE AREA
WILL HAVE A CHANCE TO SEE A FEW FLAKES BUT FREEZING DRIZZLE AND OR
FREEZING RAIN SEEMS A MORE LIKELY FORECAST. WHILE WE ARE EXPECTING
ANY WINTRY PRECIPITATION ACCUMULATIONS TO REMAIN LIGHT LOCATIONS NORTH
OF THE DALHART TO ELKHART LINE COULD SEE BETWEEN 1 TO 3 INCHES OF
SNOW WHILE THERE WILL BE A CHANCE FOR LIGHT ICE ACCUMULATIONS ACROSS
ELEVATED SURFACES ACROSS THE PANHANDLES.
SATURDAY REMAINS THE LULL DAY BEFORE A CLOSED UPPER LEVEL LOW EJECTS
FROM THE DESERT SOUTHWEST. AS THIS LOW MOVES ACROSS THE PANHANDLES WE
COULD SEE ANOTHER ROUND OF WINTRY PRECIPITATION WHICH MAY NEED AN
ADVISORY FOR THE SATURDAY NIGHT AND SUNDAY TIME FRAME. BY MONDAY DRIER
CONDITIONS BEGIN TO SETTLE IN FOR THE LATER HALF OF THIS FORECAST
CYCLE.
&&
.FIRE WEATHER...
NEITHER ELEVATED NOR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
FOR THE NEXT SEVEN DAYS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/14
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
409 AM CST THU NOV 21 2013
.SHORT TERM...
A STRONG COLD FRONT WAS BARRELING SOUTH THIS MORNING THROUGH THE
HIGH PLAINS. AT 3 AM CST THE LEADING EDGE OF THE FRONT WAS LOCATED
NEAR PUEBLO COLORADO TO GREAT BEND KANSAS. NORTHERLY WINDS OF 25 TO
35 MPH WERE BLOWING BEHIND THE FRONT WITH 6 TO 8 MB/6 HR PRESSURE
RISES AND TEMPERATURES WERE QUICKLY DROPPING INTO THE SINGLE DIGITS
ACROSS MUCH OF WYOMING. THE FRONT/S ADVANCE WAS A COUPLE HRS AHEAD OF
NAM AND GFS GUIDANCE...NOT UNUSUAL...WHILE THE HRRR AND RAP
SHORT-RANGE PROGS WERE MORE IN LINE WITH THE FRONT/S ACTUAL
PROGRESS. THE RAP SUGGESTS A WEAK NW-N WIND SHIFT WILL WORK THROUGH
THE CWFA THIS MORNING. THIS SHOULD HELP SCOUR OUT THE LOW STRATUS AND
FOG FROM NORTH TO SOUTH EARLY TO MID MORNING. THE ACTUAL FRONT COULD
BE ON THE DOORSTEP OF OUR NORTHERN COUNTIES BY ABOUT NOON...AND
CLEAR OUR SRN COUNTIES BY 5 PM OR SO. HIGH TEMPERATURES MAY BE
REACHED AROUND NOON ACROSS THE NORTH...WITH TEMPS FALLING IN THE
AFTERNOON...THEN FALLING QUICKLY FOR ALL AREAS IN THE EVENING AS THE
CAA REALLY TAKES HOLD. WE/VE COOLED TEMPS DOWN QUITE A BIT ACROSS
THE NORTH WHILE WE STILL EXPECT SOUTHERN ZONES TO REACH THE UPPER
60S AND LOW 70S BEFORE THE FRONT HITS.
IT APPEARS THAT THE PRE-FRONTAL WIND SHIFT AND EARLIER FROPA WILL
REALLY LIMIT T-STORM CHANCES THIS AFTERNOON AND EVENING...LIKELY
CONFINING THE RISK AREA TO THE EASTERN AND SOUTHERN ROLLING
PLAINS...AND WE/VE TRIMMED POPS BACK ACCORDINGLY. STRONG LIFT ALONG
THE FRONT MAY LEAD TO THE DEVELOPMENT OF A THIN LINE OF STORMS AS
SUGGESTED BY THE TTU-WRF. SOME ISOLD STRONGER CORES WITH SMALL HAIL
ARE POSSIBLE...BUT SEVERE POTENTIAL LOOKS SMALL.
THEN THE MAIN FOCUS WILL QUICKLY SHIFT TO TIMING THE CHANGEOVER TO
FREEZING PRECIP FRIDAY EVENING AND WHAT ARE THE POTENTIAL
ACCUMULATIONS. FORECAST TEMP PROFILES SHOW THAT THE SWITCH COULD
BEGIN AS EARLY AS 8 OR 9 PM ACROSS THE FAR SRN PANHANDLE WITH TEMPS
LIKELY COLD ENOUGH TO SUPPORT FROZEN PRECIP ACROSS THE ENTIRE CWA
ASIDE FROM THE SOUTHERN ROLLING PLAINS BY AROUND MIDNIGHT.
HOWEVER...FRIDAY EVENING...FORECAST SOUNDINGS DO NOT SHOW DEEP
SATURATION THUS WE ANTICIPATE THAT PRECIP INITIALLY IN THE WAKE OF
THE FRONT WILL START OUT AS DRIZZLE...THEN MIX AND SWITCH TO
FREEZING DRIZZLE. DEEPER SATURATION AND BETTER MID-LVL LIFT IS
PROGGED TO ARRIVE AFTER MIDNIGHT AND DURING THE MIDNIGHT TO 6 AM
PERIOD WE SHOULD SEE BETTER CHANCES AT SOME SLEET AND FREEZING RAIN.
SLEET WILL ALSO BE MORE LIKELY ACROSS THE COLDER AREAS OF THE NW
SPLNS AND SW TX PANHANDLE...WITH FREEZING DRIZZLE/RAIN DOMINANT IN
THE ROLLING PLAINS. FORECAST ICE/SLEET PRECIP ACCUMULATIONS LOOK
MINIMAL BEFORE MIDNIGHT...THEN INCREASE SOMEWHAT BY 6 AM...ALTHOUGH
REMAINING LIGHT. THE INITIAL ACCUMULATIONS WILL ALSO /HOPEFULLY/ BE
MITIGATED SOMEWHAT BY THE RELATIVELY WARM GROUND. THUS...AT THIS
TIME WE WILL NOT HOIST ANY WINTER WEATHER ADVISORIES...ALTHOUGH IT
IS NOT OUT OF THE QUESTION THAT ONE MAY BE NEEDED AFTER MIDNIGHT.
ALSO OF NOTE WILL BE THE GUSTY NORTH WINDS AND THE COLD WIND CHILL
TEMPS. BOTH OF THESE ARE EXPECTED TO FALL SHORT OF ADVISORY
CONDITIONS BUT WILL CONTRIBUTE TO AN OVERALL WINTRY ATMOSPHERE.
&&
.LONG TERM...
A COMPLEX FORECAST CONTINUES ON IN THE LONG TERM FORECAST THROUGH
AT LEAST EARLY NEXT WEEK. THE MAIN ISSUE WILL BE THE PRECIPITATION
TYPE AND INTENSITY. BEST CHANCES OF PRECIPITATION WILL BE
MAINTAINED DURING THE DAY ON FRIDAY WITH LESSER CHANCES ON
SATURDAY. LIFT FROM WARM AIR ADVECTION ABOVE THE COLD AIR DOME
WILL GENERALLY BE WEAK. FLOW ON THE MOIST ISENTROPIC SURFACES WILL
BE ONLY 5-10 KNOTS THROUGH THE DURATION OF THE EVENT.
HOWEVER...SOME STRONGER FLOW MAY BE POSSIBLE NEAR THE TEXAS/NEW
MEXICO STATE LINE. A MID LEVEL DRY LAYER AROUND 700MB WILL ENTER
THE AREA ON FRIDAY WHICH ADDS SOME ADDITIONAL COMPLEXITY TO THE
PRECIPITATION TYPE. AS COLD AS THE TEMPERATURE WILL BE AT THE
SURFACE...WOULD MOSTLY EXPECT EITHER FREEZING DRIZZLE OR SLEET.
THE WARM LAYER ALOFT WILL START OUT ON FRIDAY AROUND AN ASTOUNDING
7-9C BUT SLOWLY WEAKEN THROUGH THE EVENT. THE SUBFREEZING LAYER AT
THE SURFACE ON FRIDAY WILL BE AROUND 3KFT ALLOWING FOR POSSIBLE
SLEET TO DEVELOP. WITH THE LIFT GENERALLY BEING WEAK...WOULD
ANTICIPATE MORE DRIZZLE THAN RAINFALL. THERE MAY BE A SLIGHT LULL
IN PRECIPITATION ON SATURDAY WITH SOME LOW LEVEL DRYING BEFORE THE
NEXT SYSTEM AFFECTS THE REGION.
MODELS ARE COMING IN AN AGREEMENT IN MOVING A CLOSED LOW FROM WEST
TO EAST DIRECTLY OVER THE AREA INSTEAD OF EJECTING IT OUT MORE
NORTH. PRECIPITATION TYPE STILL IS AMBIGUOUS AT THIS TIME BUT
PRECIPITATION CHANCES WERE RAISED AREA WIDE WITH GROWING
CONFIDENCE IN THE TRACK OF THIS SYSTEM. THE UPPER LEVEL SYSTEM IS
FORECAST TO SWEEP OUT OF WEST TEXAS ON TUESDAY BUT WE COULD SEE
SOME TROWAL PRECIPITATION BEFORE THE SYSTEM FINALLY DEPARTS EAST.
AFTERWARDS...TEMPERATURES WILL WARM IN TIME FOR A THANKSGIVING DAY
FEAST. JDV
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 55 17 26 19 31 / 0 20 40 30 20
TULIA 59 19 27 23 34 / 10 20 40 30 20
PLAINVIEW 64 21 27 23 33 / 10 20 40 30 20
LEVELLAND 67 22 29 21 33 / 0 30 40 30 20
LUBBOCK 69 23 29 24 33 / 10 30 40 30 20
DENVER CITY 68 23 29 22 33 / 0 40 40 30 20
BROWNFIELD 70 24 29 24 34 / 10 40 40 30 20
CHILDRESS 65 24 31 27 38 / 20 30 40 30 20
SPUR 72 25 31 26 37 / 20 40 40 30 20
ASPERMONT 73 27 32 29 39 / 20 50 40 30 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/01
AREA FORECAST DISCUSSION
NWS PUEBLO CO
315 PM MST THU NOV 21 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 248 PM MST THU NOV 21 2013
...SNOW BAND TO BRING LOCALLY HEAVY SNOW AMOUNTS TO PART OF SOUTHERN
COLORADO...
CURRENTLY...
ARCTIC AIRMASS HAS MOVED ACROSS THE PLAINS...WITH TEMPS IN THE 20S
PLAINS AND OVC SKIES. COLD AIR HAS NOT MADE IT OVER THE MTNS YET AND
THE SLV STILL HAD TEMPS AOA 50F.
A WELL DEFINED JET STREAK WAS NOTED RAGING ACROSS S CALIF INTO THE 4
CORNERS.
REST OF TODAY THROUGH TOMORROW...
SIMULATIONS CONTINUE TO INDICATE A SNOW BAND CAPABLE OF LOCALLY
HEAVY SNOW WILL SET UP OVER SOUTHERN COLORADO LATER THIS EVENING
INTO TOMORROW. THE GUIDANCE HAS BEEN VERY CONSISTENT WITH THIS BAND
OVER THE LAST SEVERAL DAYS. LATEST 18Z NAM CONTINUES TO SHOW THIS
PATTERN AND THE HRRR SUPPORTS THE DEVELOPMENT OF THIS BAND. THIS
BAND IS ASSOCIATED WITH A BAROCLINIC ZONE IN THE 600-7000MB LAYER
THAT IS PROGGED NOT TOO MOVE TOO MUCH. IT APPEARS AT THIS TIME THE
BEST CHANCE OF HEAVIER SNOW WILL FALL GENERALLY ALONG AND SOUTH OF
US HIGHWAY 50.
SNOWFALL AMOUNTS WITH THIS BAND FOR TONIGHT THROUGH TOMORROW
ACCORDING TO GUIDANCE ARE RATHER IMPRESSIVE..AND HAVE CUT BACK FROM
GUIDANCE...STILL 4-7" AMOUNTS WILL BE POSSIBLE OVER NEARLY ALL OF
THE SAN LUIS VALLEY AND MOST OF THE PLAINS GENERALLY SOUTH OF
HIGHWAY 50 AND WEST OF SPRINGFIELD.
THE SANGRES...WETS AND SAN JUANS SHOULD DO VERY WELL WITH THIS
EVENT...WITH 12-18" OVER THE SAN JUANS AND NEAR A FOOT OVER THE
SANGRES AND WETS.
FARTHER NORTH LESS SNOW IS LIKELY AND HAVE CUT BACK ON AMOUNTS IN
THE CENTRAL MOUNTAINS. HAVE ALSO DOWNGRADED WARNINGS TO ADVISORIES
FOR PARTS OF THE CENTRAL MOUNTAIN REGION.
THE PIKES PEAK REGION WILL SEE ON AND OF SNOW SHOWERS WITH 1-3"
POSSIBLE THROUGH THE PERIOD. THE BEST CHANCE OF SNOW MAY OCCUR LATER
TOMORROW AS THE BAND LIFTS A BIT TO THE NORTH. HOWEVER THE SNOW IS
EXPECTED TO BE DECREASING AS THE FRONTOGENETICAL FORCING LESSENS
WITH TIME.
TOMORROW WILL BE ANOTHER COLD DAY WITH HIGHS ON THE 20S ALL AREAS.
WE MAY SEE SOME BREAKS IN THE CLOUDS LATE IN THE DAY OVER THE
NORTHERN PARTS OF THE CWA. /HODANISH
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 248 PM MST THU NOV 21 2013
...SNOW AND COLD CONTINUES...
FRIDAY NIGHT-SATURDAY...SNOW ACROSS THE EASTERN PLAINS WILL SLOWLY
WIND DOWN BETWEEN 06Z-09Z EARLY SATURDAY MORNING ACROSS THE EASTERN
PLAINS AS THE BEST LIFT MOVES AWAY FROM THE AREA.
ATTENTION THEN TURNS TO THE CUT OFF LOW SPINNING OVER SOUTHERN
CALIFORNIA. THE GFS AND THE NAM ARE IN SOMEWHAT BETTER AGREEMENT
WITH THE EC MODELS HANDLING OF THE LOW AND AM NOW MORE CONFIDENT THE
LOW WILL TAKE A MORE NORTHERLY TRACK THEN PREVIOUS GFS FORECASTS
HAVE SHOWN. IN COORDINATION WITH DDC/GLD/GJT I HAVE INCREASED POPS
ACROSS ALL OF THE MOUNTAIN AREAS SATURDAY AND SUNDAY...AND ACROSS
THE PLAINS ON SUNDAY. IF CURRENT MODEL TRENDS CONTINUE...I AM FAIRLY
CERTAIN THE WINTER STORM WARNING FOR THE SAN JUANS WILL NEED TO BE
EXTENDED THROUGH AT LEAST SATURDAY EVENING. THE 18Z NAM12 SHOWS 30
INCHES OF SNOWFALL BETWEEN 00Z SATURDAY AND 12Z SUNDAY ACROSS THE
SAN JUANS. THE 12Z GFS PAINTS 20 INCHES DURING THE SAME TIME FRAME.
TOO EARLY TO EXTEND THE WARNING AT THIS TIME.
SUNDAY...AS SNOW CHANCES REMAIN HIGH ALONG THE CONTINENTAL
DIVIDE...MODELS DIFFER ON HOW MUCH SNOW WILL FALL ACROSS THE EASTERN
MOUNTAINS AND THE PLAINS ON SUNDAY. THE GFS/NAM12 SHOW A
VORT MAX ROTATING AROUND THE CUTOFF LOW BETWEEN 09Z-12Z SUNDAY
MORNING...AND PUSHING IT THROUGH THE EASTERN PLAINS. THE GFS IS MUCH
WEAKER WITH THIS FEATURE AND SHOWS NO MORE THEN A DUSTING OF SNOW
ACROSS THE PLAINS...3 TO 6 INCHES IN THE WET MOUNTAINS AND THE
SANGRES THROUGH 00Z MONDAY. THE NAM SHOWS ALMOST A FOOT OF SNOW
ACROSS THE SAME MOUNTAIN ZONES AND UP TO 3 INCHES ALONG THE HIGHWAY
50 CORRIDOR EAST OF PUB (LAA/LHX). I HAVE TAKEN THE MORE
CONSERVATIVE GFS ROUTE AT THIS TIME...INCREASING POPS AND SNOW
AMOUNTS SLIGHTLY. HIGHLIGHT CRITERIA MAY BE REACHED IN THE
SANGRES/WETS IF THE NAM SOLUTION VERIFIES.
MONDAY-THURSDAY...MODELS DRY OUT THE FORECAST AREA RATHER QUICKLY
MONDAY...WITH ONLY A FEW REMAINING SNOW SHOWERS MONDAY MORNING. WEST
AND NORTHWEST FLOW WILL KEEP THE AREA DRY THROUGHOUT THE PERIOD.
500MB AND 700MB WINDS TURN MORE WEST AND SOUTHWEST LATE WEDNESDAY
THROUGH THURSDAY AHEAD OF ANOTHER PACIFIC STORM SYSTEM. TEMPERATURES
WILL REBOUND BACK TO AVERAGE LEVELS AS WELL. -PJC
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 248 PM MST THU NOV 21 2013
A SNOW BAND WILL DEVELOP OVER SOUTHERN COLORADO LATER THIS AFTERNOON
AND LAST INTO TOMORROW. THE HEAVIEST SNOW WILL FALL GENERALLY ALONG
AND SOUTH OF HIGHWAY 50. KALS WILL BE IMPACTED WITH SIGNIFICANT
ACCUMULATING SNOW LIKELY...WITH UP TO 6" POSSIBLE. SNOW WILL BEGIN
AT KALS THIS EVENING...~03Z...AND LAST INTO TOMORROW.
KPUB WILL BE ON THE NORTHERN GRADIENT BUT STILL EXPECT 1-3" OF
ACCUMULATING SNOW TONIGHT INTO TOMORROW.
KCOS WILL SEE MUCH SNOW...BUT LOW CIGS WILL LIKELY LAST THROUGH
TOMORROW. THE BEST CHANCE FORM SOME ACCUMULATING SNOW MAY ACTUALLY
BE TOMORROW AFTERNOON AS THE BAND LIFTS A BIT TO THE NORTH.
GIVEN THE CURRENT GUIDANCE...ALL AIRPORTS...KCOS...KALS AND KPUB
WILL SEE IFR CONDITIONS FORM MOST IF NOT ALL OF THE NEXT 24H.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 6 PM MST
FRIDAY FOR COZ062-063-076>078-083-086-089-093-097>099.
WINTER WEATHER ADVISORY UNTIL 6 PM MST FRIDAY FOR COZ058-059-061-
064.
WINTER STORM WARNING FROM 11 PM THIS EVENING TO 6 PM MST FRIDAY
FOR COZ069>075-079-080-087-088-094.
WINTER STORM WARNING UNTIL 6 PM MST FRIDAY FOR COZ060-065>068.
&&
$$
SHORT TERM...HODANISH
LONG TERM...PJC
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1239 PM MST THU NOV 21 2013
.UPDATE...
ISSUED AT 1238 PM MST THU NOV 21 2013
SHALLOW COLD FRONT HAS SLIPPED TO THE NORTH SIDE OF THE
ROAN/TAVAPUTS PLATEAUS BY MIDDAY...SETTING UP FOR SOME OVERRUNNING
PRECIPITATION THERE WITH MOIST SOUTHERLY FLOW ALOFT. VALLEY TEMPS
WERE GENERALLY IN THE 20S TO AROUND 30 ACROSS NW CO AND NEAR
FREEZING IN VERNAL...AND DON/T EXPECT MUCH WARMING UNDER THE
CLOUDS. ROADS WERE GENERALLY WET FROM FROM WEBCAMS AND SPOTTER
REPORTS WITH SOME ACCUMULATING ON THE GRASS...BUT THINK ROADS WILL
BEGIN COLLECTING SNOW HEADING INTO EVENING. THUS...HAVE ISSUED A
WINTER WEATHER ADVISORY UNTIL 9 PM FOR THE NW CO VALLEYS
EXCLUDING STEAMBOAT WITH 2-4 INCHES EXPECTED GENERALLY SOUTH OF
HWY 4O. ALSO EXTENDED THE ADVISORY FOR THE EASTERN UINTAS AND
FLATTOPS...AND ADDED ZONE 4 TO THE ADVISORY BASED ON SPOTTER
REPORTS OF 6-8 INCHES AROUND HAHNS PEAK AND STEAMBOAT LAKES.
CLOUDS CONTINUE TO INDICATE A CONVECTIVE NATURE ON VISIBLE
SATELLITE IMAGES ACROSS SE UT/SW CO FOR A SHIFT TO MORE SHOWERY
PRECIPITATION...WITH SOME BREAKS IN THE CLOUD COVER. WITH THE
LIGHTNING POTENTIAL INDEX SHOWING SOME THREAT OF
THUNDERSTORMS AND THE AREA BEING IN SPC DAY 1 CONVECTIVE OUTLOOK...
HAVE ADDED ISOLATED THUNDERSTORMS THIS AFTERNOON TO SE UT AND SW CO.
UPDATE ISSUED AT 843 AM MST THU NOV 21 2013
A COLD FRONT WAS SLIPPING SOUTH ACROSS NE UT/NW CO THIS MORNING
AND APPEARS TO HAVE PUSHED TO ROUGHLY A MEEKER TO PRICE LINE.
PRECIPITATION WAS IN THE FORM OF SNOW AT CRAIG...MEEKER...AND JUST
CHANGED TO SNOW AT VERNAL. SURFACE AIR NEAR SATURATION IN MANY
PLACES FOR AREAS OF FOG AS WELL. 14Z RUC SHOWED THE FRONT STALLING
AROUND THE I-70 CORRIDOR OR A LITTLE SOUTH THIS AFTERNOON...WITH
HI-RESOLUTION HRRR MODEL INDICATING SOME OVERRUNNING PRECIPITATION
ACROSS NE UT/NW CO INTO THE AFTERNOON. WILL HAVE TO WATCH THIS
AREA FOR SNOW ACCUMULATION BUT FOR NOW ANTICIPATE THE TEMPS WILL
BE WARM ENOUGH TO PREVENT HIGHLIGHT CRITERIA SNOW ACCUMS THERE
TODAY. CLOUDS HAVE A CONVECTIVE NATURE ON VISIBLE SATELLITE IMAGES
THIS MORNING ACROSS SE UT/SW CO FOR A SHIFT TO MORE SHOWERY
PRECIPITATION AT LEAST IN THE SOUTHERN VALLEYS DURING THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
DEEP MOISTURE CONTINUES TO LINGER OVER THE REGION FROM THE PAST
FEW DAYS OF ATMOSPHERIC SATURATION. 300K/305K MOISTURE TRANSPORT
VECTORS SHOW A STEADY STREAM OF ZONAL MOISTURE FROM ABOUT THE FOUR
CORNERS SOUTH...BUT THAT IS NOT STOPPING MOST OF WESTERN CO AND
EASTERN UT FROM CONTINUING TO PRECIPITATE EARLY THIS MORNING. IR
SATELLITE AND RADAR SHOW INDICATE SHOWERS WITH LOW CLOUD TOPS
MOVING NORTHEAST AND BEGINNING TO BREAK UP...BUT NEARLY EVERY WX
STATION IN THE CWA IS REPORTING LIGHT PRECIPITATION AND/OR FOG.
A CLOSED UPPER LEVEL LOW CURRENTLY OVER NORTHERN CA AND NEVADA IS
SLOWLY MAKING ITS WAY EASTWARD...AND AS IT DOES...A LONG FETCH OF
SOUTHWEST FLOW WILL PROVIDE STRONG ISENTROPIC UPLIFT OVER AN
ALREADY COOL AIRMASS. SIGNIFICANT SNOWFALL IS EXPECTED AT ALL
SOUTHERN CO/UT MOUNTAIN LOCATIONS.
ANOTHER MAJOR FACTOR IN TODAY/S WEATHER IS STRONG FRONTOGENESIS
WHICH WILL BE OVER NORTHERN UT AND CO AROUND NOON TODAY MAKING
IT/S WAY SOUTH TO THE FOUR CORNERS BY THURSDAY NIGHT. THIS
STRENGTHENING FRONTAL PASSAGE WILL LOWER SNOW LEVELS FROM NORTH TO
SOUTH TODAY BEFORE ERODING INTO THE LARGER TROUGH FUELED BY THE
CLOSED LOW OVER NEVADA. EXPECTING COLD ADVECTIVE-INDUCED SNOW
SHOWERS NORTH OF THE FRONT. SOUTHWEST FLOW WILL STRENGTHEN BY
THURSDAY NIGHT AND TRANSPORT A SLUG OF MOISTURE BACK INTO THE
REGION OVER A DEFORMATION ZONE LEFTOVER BY THE COLD FRONT FROM
THURSDAY AFTERNOON. WITH SUCH A SATURATED ENVIRONMENT ALREADY AND
A STRONG DEFORMATION ZONE...IT WILL NOT TAKE MUCH TO PRODUCE A LOT
OF PRECIPITATION WITHIN A MATTER OF HOURS OVERNIGHT AND FRIDAY
MORNING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 AM MST THU NOV 21 2013
MODELS SHOW THE UPPER LEVEL LOW MOVING VERY SLOWLY WITH PIECES OF
ENERGY KEEPING CLOUD COVER AND PRECIPITATION IN THE PICTURE
THROUGH THE EARLY PART OF THE WEEKEND. NORTHERN UT/CO ARE NOT LIKELY TO
SEE MUCH IN THE WAY OF PRECIPITATION BY THE TIME FRIDAY NIGHT
ROLLS AROUND.
SATURDAY THROUGH WEDNESDAY...FOR THE MOST PART THE MID-RANGE
MODELS ARE IN MUCH BETTER AGREEMENT IN TIMING THE SW U.S. AS IT
MOVES FROM BAJA CALIFORNIA INTO NM SAT THROUGH MON. ON SAT THE
LOW CENTER SHOULD BE OVER SOUTHERN CA WITH ITS COLD FRONT
ORIENTATED N TO S OVER CENTRAL AND EASTERN AZ. THROUGHOUT SAT A
FOUNTAIN OF STRONG MOIST SOUTHERLY FLOW FEEDING INTO STRONG UPPER
DIVERGENCE WILL MOVE OVER SE UT AND SRN CO...ALL SPREADING OUT
INTO A DEFORMATION ZONE OVER CENTRAL AND NORTHERN CO AND UT. THIS
SETUP SHOULD CONTINUE WIDESPREAD PCPN OVER THE SOUTHERN TWO THIRDS
OF THE FORECAST AREA AND HAVE INCREASED CLOUD COVER AND POPS TO
REFLECT THIS.
THE GFS AND ECMWF BOTH PLACE THE CLOSED LOW OVER CENTRAL AZ AT
18Z ON SUNDAY AND PUSH THE COLD FRONT EAST OF THE AREA ALONG WITH
THE BEST UPWARD MOTION. ABOUT THIS TIME MOISTURE IS PROJECTED TO
BEGIN WRAPPING AROUND THE NORTH SIDE OF THE LOW...THOUGH THERE
ISN`T A STRONG TROWAL SIGNATURE IN THE TEMP FIELDS. STILL...THE
MOISTURE IN THE E AND NE FLOW TO THE NORTH OF THE LOW CENTER
SHOULD KEEP CLOUDS AND PCPN OVER THE SOUTHERN PART OF THE FORECAST
AREA UNTIL MONDAY MORNING.
TUESDAY AND WEDNESDAY...A RIDGE WILL BUILD OVER THE WESTERN U.S.
AND BRING A WARMING AND DRYING TREND OF CO AND UT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT
1226 PM MST THU NOV 21 2013
WIDESPREAD LOW CLOUDS AND PRECIPITATION OVER THE NEXT 24 HOURS WILL
PRODUCE PERIODS OF MVFR AND IFR CONDITIONS AT THE MOUNTAIN AND
HIGH VALLEY TAF SITES AND AIRPORTS. MOST MOUNTAINS AND HIGH
MOUNTAIN PASSES WILL BE OBSCURED BY CLOUDS AND SNOWFALL. OTHER TAF
SITES AND AIRPORTS WILL SEE PERIODS OF MVFR CIGS AND VSBYS FROM
RAIN OR SNOW.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING FOR
COZ001>003.
WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR COZ018-019.
WINTER STORM WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR COZ014.
WINTER STORM WARNING UNTIL MIDNIGHT MST FRIDAY NIGHT FOR COZ009-
010-012-017.
WINTER WEATHER ADVISORY UNTIL 6 AM MST FRIDAY FOR COZ004-013.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM MST SATURDAY
FOR COZ022-023.
UT...WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING FOR UTZ023-
025.
WINTER STORM WARNING UNTIL 6 PM MST SATURDAY FOR UTZ028.
&&
$$
UPDATE...JAD
SHORT TERM...JAM
LONG TERM...JAM/CC
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1013 AM MST THU NOV 21 2013
.UPDATE...
&&
.SHORT TERM...MAIN BATCH OF LIFT HAS MOVED ONTO THE FAR EASTERN
PLAINS...RADAR IS INDICATING THE WIDESPREAD LIGHT TO MODERATE
SNOW IS CURRENTLY LOCATED THERE. STILL SOME LIGHT SNOW ALONG THE
FOOTHILLS AND URBAN CORRIDOR. FROM WEB CAMS...IT LOOKS LIKE ONLY
SCATTERED AREAS OF LIGHT SNOW ACROSS THE MOUNTAINS. STILL
EXPECTED OCCASIONAL LIGHT SNOW TO CONTINUE THROUGH THE
AFTERNOON...AS THERE WILL STILL BE WEAK LIFT ACROSS THE AREA WITH
THE MAIN LOW STILL SOUTHWEST OF COLORADO. LATEST MODELS INDICATING
ANY ADDITIONAL SNOW ACCUMULATION TO BE 3 INCHES OR LESS THROUGH
THE AFTERNOON...WITH THE HIGHEST AMOUNTS FAR EASTERN PLAINS. WITH
COLD AIRMASS IN PLACE...SHOULDN`T TAKE MUCH FOR SNOW TO BE
GENERATED WITH THE WEAK LIFT. WITH ONLY LIGHT SNOW EXPECTED...WILL
LET THE ADVISORY FOR THE FOOTHILLS AND URBAN CORRIDOR EXPIRE AT
NOON AND KEEP THE ADVISORY FOR THE REST OF THE PLAINS GOING FOR
THE AFTERNOON WHERE THERE IS BETTER LIFT. LATEST RAP IS HINTING AT
AN INCREASE IN MID LEVEL QG ASCENT LATER THIS AFTERNOON AND EARLY
EVENING WHICH COULD INCREASE THE SNOW. FOR NOW WILL LEAVE THE
CURRENT POPS GOING AND WILL ADDRESS THIS LATER.
.AVIATION...MAIN BATCH OF SNOW HAS MOVED EAST ONTO THE PLAINS.
STILL LIGHT SNOW ONGOING ACROSS THE DENVER AREA...WITH AN AREA OF
MODERATE SNOW MOVING EAST ACROSS WESTERN ADAMS COUNTY INTO THE
DENVER AREA. STILL EXPECTING MFR CONDITIONS TO PREVAIL THROUGH THE
AFTERNOON WITH AREAS OF IFR CONDITIONS. IMPROVEMENT STILL EXPECTED
BY MIDNIGHT. OVERALL CURRENT TAF TRENDS SEEM REASONABLE.
ADDITIONAL ACCUMULATIONS OF AROUND AN INCH.
&&
.PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 21 2013/
SHORT TERM...IT APPEARS THAT THE STRONGEST WINDS...GREATEST
TEMPERATURE GRADIENT...AND STRONGEST LIFT ASSOCIATED WITH THE
OVERNIGHT COLD FRONT HAVE PASSED OUR AREA. COLD ADVECTION ON NORTH
WINDS WILL CONTINUE TODAY WITH TEMPERATURES ON THE PLAINS STEADY
OR FALLING AND LITTLE TEMPERATURE RISE IN THE MOUNTAINS. THERE
STILL APPEARS TO BE WIDESPREAD LIGHT SNOW IN THE COLD AIR. MAIN
CHANGE FROM LAST NIGHTS FORECAST IS TO ACCOUNT FOR THE SECONDARY
AREA OF WEAK LIFT EVIDENT ON THE SATELLITE PICTURES AND RADARS NOW
OVER NORTHWESTERN COLORADO. WHILE THE OROGRAPHIC ENHANCEMENT ON
THE PALMER DIVIDE SHOULD FADE THIS MORNING...THIS AREA OF LIFT
WILL MOVE OVER THE COLD AIR COVERING NORTHEASTERN COLORADO. SO THE
FOCUS SHOULD SHIFT FROM THE SOUTHERN PART OF OUR AREA BACK TOWARD
THE NORTH THIS MORNING...THEN WE SHOULD SEE A FURTHER DECREASE IN
THE SNOW THIS AFTERNOON BUT THERE COULD STILL BE SOME WEAK LIFT
OVER THE NORTHERN BORDER AREAS. THE NEXT BATCH OF LIFT STILL
EXPECTED TO GO FURTHER SOUTH...MAINLY SOUTH OF OUR AREA...BUT THIS
WILL NEED TO BE WATCHED AS WELL AS IT WILL NOT TAKE MUCH TO
GENERATE MORE LIGHT SNOW. THIS THREAT SEEMS TO BE DEALT WITH
ADEQUATELY AT THIS TIME...BUT WE MAY NEED HIGHER POPS FURTHER
NORTH TONIGHT.
SNOWFALL SHOULD REMAIN LIGHT FOR THE MOST PART...PERHAPS NOT UP TO
THE USUAL ADVISORY CRITERIA IN MOST PLACES. HOWEVER THE ROADS GOT
WETTED DOWN PRETTY WELL LAST NIGHT AND TEMPERATURES WILL BE IN THE
TEENS THIS MORNING...SO IT SEEMS THERE IS A PRETTY SUBSTANTIAL
THREAT OF ICY ROADS. I WILL HANG ON TO THE ADVISORIES WE HAVE AND
ADD AN ADVISORY THROUGH 4 PM FOR NORTHEASTERN COLORADO WHERE THE
MOST SNOW MAY BE DURING THE DAY.
LONG TERM...AN UPPER LEVEL LOW WILL REMAIN CUT OFF OVER NEAR
BAJA CALIFORNIA ON FRI WITH WSW FLOW ALOFT. MEANWHILE COLD HIGH
PRES AT THE SFC WILL REMAIN OVER ERN CO. CROSS-SECTIONS SHOW
ABUNDANT MOISTURE ACROSS THE MTNS HOWEVER LAPSE RATES ARE POOR AND
THERE IS NO MID LVL ASCENT. AT THIS TIME IT LOOKS LIKE THE BEST
CHC OF SNOW IN THE MTNS WILL BE SOUTH OF I-70 WITH ONLY LIGHT
ACCUMULATIONS. OVER NERN CO THERE IS NO UPSLOPE COMPONENT AS A
SHALLOW LYR OF COLD AIR WILL REMAIN OVER THE AREA SO WILL KEEP
HIGHS IN THE UPPER 20S TO LOWER 30S. THERE COULD BE SOME LINGERING
LIGHT SNOW OVER THE SRN FOOTHILLS AND OVER THE PALMER DIVIDE SO
WILL KEEP IN SOME LOW POPS IN THESE AREAS.
BY SAT THE UPPER LEVEL LOW WILL BE OVER SRN CALIFORNIA WITH QUITE A
BIT OF MID AND HIGH LEVEL MOISTURE IN SWLY FLOW ALOFT MOVING ACROSS
THE AREA. ONCE AGAIN COULD SEE A CHC OF SNOW SHOWERS IN THE MTNS
THRU THE DAY HOWEVER WITH POOR LAPSE RATES AMOUNTS SHOULD BE LIGHT.
MEANWHILE ANOTHER SURGE OF COLD AIR IS FCST TO MOVE SE ACROSS THE
NRN AND CNTRL PLAINS ON SAT WITH SOME OF THIS AIR POSSIBLY AFFECTING
NERN CO. AS A RESULT 850-700 MB TEMPS DO NOT CHANGE MUCH ON SAT SO
WILL KEEP READINGS IN THE 30S.
FOR SUN THE UPPER LEVEL LOW OVER THE SWRN US WILL BEGIN TO MOVE ENE
THRU SUN NIGHT. THE GFS KEEPS THE BULK OF THIS SYSTEM OVER THE SRN
ROCKIES WITH MOST OF THE MOISTURE AND PCPN STAYING OVER SRN CO.
MEANWHILE THE ECMWF AND GEM SHOW A SIGNIFICANT PIECE OF ENERGY
MOVING NE INTO ERN CO BY SUN EVENING WITH PCPN THREAT MUCH FURTHER
NORTH AFFECTING THE NERN PLAINS. AT THIS TIME WILL MENTIONS SOME
LOW POPS MAINLY OVER SRN AREAS OF THE CWA FOR SUN AFTN AND NIGHT.
IN THE MTNS LOOKS LIKE THE BEST CHC OF SNOW WILL BE MAINLY SOUTH OF
I-70. AS FOR HIGHS WILL WRM HIGHS BACK INTO THE LOWER TO MID 40S
OVER NERN CO ALTHOUGH THE FAR ERN PLAINS COULD STAY IN THE 30S
DEPENDING ON CLOUD COVER.
BY MON THE UPPER LEVEL LOW IS FCST TO MOVE MORE ESE WITH DRIER AIR
MOVING INTO NRN CO. THUS THIS WOULD END PCPN CHANCES AND ALLOW FOR
WARMER TEMPS WITH READINGS IN THE 45 TO 50 DEGREE RANGE OVER NERN
CO. FOR TUE A FLAT UPPER LEVEL RIDGE WILL BE OVER NRN CO WITH DRY
CONDITIONS. TEMPS SHOULD CONTINUE TO MODERATE WITH READINGS NEAR
SEASONAL LEVELS. ON WED THE FLAT UPPER LEVEL RIDGE IS FCST TO
CONTINUE WITH LITTLE CHC FOR PCPN. MEANWHILE ANOTHER COLD FNT MAY
MOVE INTO NERN CO DURING THE DAY BRINGING COOLER TEMPS.
AVIATION...LIGHT SNOW IS EXPECTED THROUGH THE MORNING WITH IFR
CONDITIONS PREVAILING. GRADUAL IMPROVEMENT WITH MVFR PREVAILING
THIS AFTERNOON AND EVENING...BUT STILL AREAS OF IFR. FURTHER
IMPROVEMENT IS POSSIBLE AFTER MIDNIGHT...AND LIKELY BY FRIDAY
MORNING. ADDITIONAL SNOWFALL AT THE DENVER AREA AIRPORTS WILL
LIKELY BE IN THE 1 TO 2 INCH RANGE...MAINLY THIS MORNING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR COZ042-
044-048>051.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ035-036-
038>041-043-045-046.
&&
$$
SHORT TERM...D-L
LONG TERM....RPK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 PM CST THU NOV 21 2013
.DISCUSSION...
304 PM CST
TONIGHT...
CONSIDERABLE SOLAR SHIELDING HAS KEPT TEMPERATURES IN CHECK FOR MUCH
OF THE DAY IN THE MID/UPR 40S...EXCEPT FOR THE FEW THIN SPOTS IN THE
CLOUDS THAT ALLOWED TEMPS TO QUICKLY BUMP TO 50 DEGREES. HOWEVER
THESE THIN SPOTS HAVE SINCE DISSIPATED. A QUASI-STATIONARY BOUNDARY
WAS ORIENTED FROM CENTRAL MISSOURI NORTHEAST THROUGH LEE/OGLE COUNTY
AND TO AROUND MILWAUKEE...THEN STRETCHING EAST ACROSS LOWER
MICHIGAN. NORTH OF THIS BOUNDARY SLIGHTLY DRIER AIR WAS BEGINNING TO
SEEP SOUTH/SOUTHEAST...MEANWHILE SOUTH OF THE BOUNDARY DEW PTS HAVE
RISEN INTO THE LOW/MID 40S. JUST WEST OF THE CWFA...TEMPS HAVE BEEN
ABLE TO COOL INTO LOW 30S AND PRECIP WAS FALLING AS A MIX OF
RA/SN/SLEET. ACROSS NORTHCENTRAL IOWA TEMPS ARE MUCH COOLER IN THE
20S AND PRECIP IS MAINLY LIGHT SNOW.
A VERY WEAK WAVE WILL RIDE ALONG THE FRONTAL BOUNDARY AND HELP TO
RE-DEVELOP PRECIP...SLOWLY OVERSPREADING THE REMAINDER OF NORTHERN
IL/NORTHWEST IN LATER THIS EVE. LATEST GUIDANCE COUPLED WITH
SOUNDINGS...SUGGEST ANY PRECIP OVER OUR CWFA THIS EVENING SHOULD
REMAIN IN LIQUID FORM AND BE LIGHT WITH MINIMAL LIFT IN THE NEAR SFC
ENVIRONMENT. HOWEVER AS THE BOUNDARY BEGINS TO SLOWLY SHIFT
SOUTHEAST OVERNIGHT...TEMPS WILL STEADILY COOL AND START TO
INTRODUCE A RAIN/SNOW MIX FOR THE FAR NORTH/NORTHWEST PORTIONS OF
THE CWFA.
TEMPS OVERNIGHT WILL HINGE UPON THE PLACEMENT OF THE FRONTAL
BOUNDARY...WITH TEMPS ALONG AND SOUTHEAST OF A PONTIAC TO CHICAGO
LINE HOLDING ARND 40 DEGREES. TO THE NORTHWEST OF THIS LINE TEMPS
WILL LIKELY FALL INTO THE MID/UPR 30S.
CONFIDENCE...HIGH.
FRIDAY THROUGH FRIDAY NIGHT...
MAIN FOCUS FOR FRI WILL BE ON THE ENDING TIME OF PRECIP...WHICH
GUIDANCE DIFFERS ON. WITH THE LACK OF A STRONG PUSH TO THE FRONTAL
BOUNDARY EARLY FRI...IT APPEARS LIGHT PRECIP/DRIZZLE/FLURRIES WILL
PERSIST FOR PORTIONS OF THE CWFA. AS THE DAY
PROGRESSES...ANTI-CYCLONIC FLOW ACROSS THE NORTHERN PLAINS WILL
SLIDE SOUTH/SOUTHEAST...AND HELP TO FURTHER ERODE ANY LINGERING
MOISTURE. LCL ARW 8KM SIMULATION INDICATES PRECIP ENDING ARND
13-15Z...HOWEVER RH FIELDS IN THE 1050-850MB LAYER HOLD TOUGH AT 90%
WOULD COULD SUGGEST SOME DRIZZLE/FLURRIES OR POSSIBLY A LGT RA/SN
MIX MAY BE PATCHY THRU MID-MORNING. NORTHERLY FLOW WILL STRENGTHEN
THROUGHOUT THE DAY...WHICH WILL HELP BRING LOWER DEW PTS AND ANY
LINGERING PRECIP THAT DOES ENCOUNTER A PARTIAL MELT WILL LIKELY
MAINTAIN THE DENDRITIC FORM BY LATE MORNING BEFORE DRYING BY EARLY
AFTN HOURS.
LCL WRF INDICATES A NARROW LAKE EFFECT SNOW BAND BEGINNING EARLY FRI
MORNING...PUSHING INTO SOUTHWEST LOWER MICHIGAN. AT THIS TIME IT
APPEARS FAR NORTHWEST IN WILL REMAIN WEST OF THIS BAND OF LIGHT
SNOW.
HIGH TEMPS ACROSS THE CWFA WILL OCCUR IN THE MORNING HOURS...HOLDING
IN THE MID 30S TO LOW 40S. THERMAL TROUGH OF -4 TO -8 DEG C WILL
ARRIVE BY FRI AFTN...WHICH WILL BE MILD COMPARED TO WHAT CONTINUES
TO BE PROGGED FOR SAT.
CONFIDENCE IN PRECIP ENDING MID-MORNING...MEDIUM/HIGH.
CONFIDENCE IN TEMPS...HIGH.
SATURDAY THROUGH WEDNESDAY...
ARCTIC AIR MASS CONTINUES TO BE THE MAIN FEATURE FOR THE UPCOMING
WEEKEND...WITH A SLUG OF TEMPS AT 850MB ARND -16 TO -18 DEG C
ARRIVING SAT. BY SUN THE 500MB TROUGH AXIS WILL BEGIN TO PIVOT
EAST...AS THE SFC RIDGE ARRIVES SAT NGT/SUN ACROSS THE REGION
PROVIDING CONTINUED DRY BUT COLD WEATHER. TEMPS SAT WILL STRUGGLE TO
WARM BEYOND THE UPR 20S...THEN IF WINDS CAN DIMINISH AS ADVERTISED
SAT NGT...TEMPS MAY TUMBLE TO THE SINGLE DIGITS ABOVE ZERO ACROSS
PORTIONS OF THE WESTERN/NORTHWEST CWFA EARLY SUN. CLOSER TO CHICAGO
AND NORTHWEST IN TEMPS WILL REMAIN IN THE LOW/MID TEENS.
THEN FOR DESPITE P-CLOUDY TO MOSTLY SUNNY SKIES...TEMPS SUN WILL
HOLD IN THE MID/UPR 20S.
A SHORTWAVE WILL TRAVERSE THE GREAT LAKES MON...WITH A CHC FOR A
PERIOD OF RAIN/SNOW. YET ANOTHER SFC RIDGE IS PROGGED TO SLIDE SOUTH
INTO THE NORTHERN PLAINS TUE AFTN/EVE...WITH NORTHWEST FLOW
RETURNING TO THE FORECAST AREA. SOME DEGREE OF CONCERN EXISTS FOR
TUE/WED AS GUIDANCE HAS HINTED THAT THE SOUTHERN STREAM VORT MAY
NUDGE FURTHER NORTH. IF THIS TREND CONTINUES...THIS MAY BECOME A
WEATHER SYSTEM OF CONCERN FOR THE HOLIDAY TRAVEL PERIOD NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS LOWERING TO IFR THIS EVENING.
* -RA THIS AFTN TAPERING TO -DZ THIS EVENING.
* GUSTY N WINDS OVERNIGHT THROUGH FRIDAY.
* -RA RETURNS EARLY FRIDAY MORNING AND CHANGES OVER TO -RASN BY
MID MORNING...AND ENDS LATE MORNING/EARLY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE IS OVER SOUTHERN ONTARIO WITH ITS COLD FRONT SLOWLY
APPROACHING NORTHERN IL FROM THE NW. THE COLD FRONT STRETCHES FROM
MILWAUKEE TO DUBUQUE WITH LIGHT WINDS JUST AHEAD OF IT. NW TO N
WINDS AND IFR TO LIFR CIGS ARE BEHIND THE FRONT. A WEAK UPPER
LEVEL DISTURBANCE IS ALSO PUSHING INTO SOUTHERN IL AND EXPECTING
THE PRECIP TO OUR SOUTH TO PUSH NORTH AHEAD OF THE DISTURBANCE.
THERE IS STILL A BIT OF UNCERTAINTY ABOUT HOW FAR NORTH THE PRECIP
WILL REACH. KEPT PRECIP AT ALL OF THE EASTERN TERMINALS BUT
DOWNGRADED RFD TO VCSH BECAUSE I THINK -RA WILL REMAIN JUST TO
ITS SOUTH. ATMOSPHERIC MOISTURE REMAINS PLENTIFUL SO CONTINUED -DZ
THROUGH THE EVENING AT ALL LOCATIONS...AND THROUGH THE MORNING AT
RFD.
CIGS HAVE BEEN DIFFICULT AS THE LOWER CIGS OVER IA AND WI HAVE NOT
BUDGED THIS MORNING. THEREFORE TIMING WHEN IF AND WHEN THEY WILL
MOVE INTO ORD HAS BEEN EXTREMELY DIFFICULT. A FEW SOUTHERN WI
SITES HAVE FINALLY REGISTERED IFR CIGS SO USED THAT TO GET THE
TIMING FEATURED IN THE TAFS. THINKING THE LOWER CIGS WILL BE TIED
TO THE PRECIP...AND IFR CIGS ARE ASSOCIATED WITH THE FRONTAL
PASSAGE. CONFIDENCE IS HIGH THAT CIGS WILL FALL...BUT LOW AS FAR
AS WHEN. ALSO KEPT LIFR OUT OF MOST OF THE TAFS DUE TO A LACK OF
CONFIDENCE...BUT LOOKING UPSTREAM THEY ARE STILL POSSIBLE.
WINDS WILL GO LIGHT AND VARIABLE AHEAD OF THE FRONT AND THEN
BECOME NNE ARND 6KT IMMEDIATELY BEHIND THE FRONT. THE GRADIENT
CONTINUES TO TIGHTEN WITH N WINDS 15G20+ KT BY FRIDAY MORNING.
RAIN ALSO RETURNS AHEAD OF THE UPPER LEVEL TROUGH AXIS. COLD AIR
MOVES IN AND PRECIP WILL BECOME A RAIN/SNOW MIX BY MID MORNING.
MAY SEE A BRIEF PERIOD OF SNOW NEAR THE END OF THE PRECIP IN THE
LATE MORNING/EARLY AFTERNOON BUT SOUNDINGS INDICATE ICE CRYSTALS
MAY NOT BE PRESENT SO ALL SNOW WILL BE DIFFICULT. NO ACCUMULATION
IS EXPECTED AT THIS TIME BUT SLICK RUNWAYS ARE LIKELY. VSBY COULD
BE MORE REDUCED THAN INDICATED BUT CIGS SHOULD BE ON A SLOW RISE.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIG TRENDS...MEDIUM-LOW CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN LIFR CIGS FORMING.
* HIGH CONFIDENCE IN PRECIP THIS EVENING AND TOMORROW...MEDIUM
CONFIDENCE IN TIMING AND CHANGE OVER TO -RASN.
* MEDIUM CONFIDENCE IN VSBY ASSOCIATED WITH PRECIP.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...DRY/VFR.
* SATURDAY...DRY/VFR. STRONG/GUSTY NORTHWEST WINDS.
* SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF RAIN/SNOW SHOWERS. MVFR POSSIBLE.
* TUESDAY AND WEDNESDAY...DRY/VFR.
&&
.MARINE...
132 PM CST
MAIN MARINE FORECAST CONCERNS INCLUDE PERIODS OF STRONG
NORTH-NORTHWEST WINDS TONIGHT INTO EARLY FRIDAY...AND AGAIN LATE
FRIDAY NIGHT THROUGH SATURDAY. A PERIOD OF GALES APPEARS LIKELY
DURING THE LATE FRIDAY NIGHT THROUGH SATURDAY TIME FRAME. WESTERLY
GALES APPEAR POSSIBLE MONDAY...IN ASSOCIATION WITH ANOTHER LOW AND
APPROACHING COLD FRONT AT THAT TIME.
WEAK LOW PRESSURE OVER THE NORTHERN LAKES WILL PULL AWAY TO THE
NORTHEAST TONIGHT...TRAILING A COLD FRONT ACROSS LAKE MICHIGAN THIS
EVENING. COLD CANADIAN HIGH PRESSURE SPREADING SOUTH ACROSS THE
PLAINS WILL RESULT IN A FAIRLY TIGHT SURFACE PRESSURE GRADIENT
DEVELOPING ACROSS THE WESTERN LAKES...WITH NORTHERLY WINDS
INCREASING TO 30 KT ACROSS LAKE MICHIGAN TONIGHT THROUGH MIDDAY
FRIDAY. WEAK HIGH PRESSURE RIDGING FROM THE EASTERN PERIPHERY OF THE
PLAINS HIGH WILL THEN MOVE ACROSS THE LAKE FRIDAY AFTERNOON ALLOWING
WINDS TO DECREASE/BACK WEST. ANOTHER LOW WILL MOVE ACROSS THE
NORTHERN LAKES LATE FRIDAY HOWEVER...TRAILING ANOTHER COLD FRONT
ACROSS THE LAKE FRIDAY NIGHT. EVEN STRONGER HIGH PRESSURE BUILDING
SOUTH FROM CANADA SATURDAY AND SATURDAY NIGHT BEHIND THIS FRONT WILL
SET UP ANOTHER PERIOD OF STRONG NORTHERLY WINDS...WITH FORECAST
SOUNDINGS CONTINUING TO DEPICT GALES FROM LATE FRIDAY NIGHT THROUGH
SATURDAY EVENING. COLD CANADIAN AIR WILL PRODUCE STEEP LOW LEVEL
LAPSE RATES DURING THIS PERIOD...WITH DEEP MIXING HELPING TO
MAXIMIZE TRANSFER OF WIND MOMENTUM TO THE SURFACE. AIR TEMPERATURES
FALLING INTO THE MID/UPPER 20S MAY PRODUCE SOME FREEZING SPRAY...BUT
WITH WATER TEMPERATURES STILL IN THE MID 40S...CONFIDENCE REMAINS
TOO LOW TO INCLUDE ANY WIDESPREAD FREEZING SPRAY CONDITIONS IN THE
FORECAST AT THIS TIME.
WINDS WILL DECREASE SUNDAY...AS THE NORTHERN PERIPHERY OF THE STRONG
SURFACE HIGH PUSHES EAST ACROSS LAKE MICHIGAN. LONGER RANGE MODEL
RUNS INDICATE ANOTHER LOW WILL MOVE ACROSS THE NORTHERN LAKES SUNDAY
NIGHT AND MONDAY HOWEVER...WITH ANOTHER COLD FRONT MOVING ACROSS THE
LAKE MONDAY NIGHT AS THE ACTIVE PATTERN CONTINUES. FORECAST GUIDANCE
INDICATES A PERIOD OF WEST-SOUTHWEST GALES ARE POSSIBLE SUNDAY NIGHT
INTO MONDAY AHEAD OF THE COLD FRONT.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...4 AM FRIDAY TO 6 AM SATURDAY.
&&
$$
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
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
217 PM CST Thu Nov 21 2013
.DISCUSSION...
ISSUED 205 PM CST Thu Nov 21 2013
Another surge of light rain was tracking northeast into our
area early this afternoon ahead of a weak shortwave over
Kansas. A nearly stationary frontal boundary stretching from
southwest Missouri northeast through eastern Wisconsin will move
little until the aforementioned wave in Kansas pushes to our
northeast tonight. Behind that boundary, Arctic air was spilling
south into the southern Plains with temperatures early this
afternoon ranging from the mid 20s to lower 30s from Kansas south
into the Panhandle of Texas.
SHORT TERM...Tonight through Sunday
Main forecast concern this period will be how quickly the precip
shuts down Friday morning and then after that, its how cold
temperatures will be this weekend. Not too much to argue about as
far as the models are concerned in the short-term as the Arctic
boundary, now to our west, will push through our area tonight with
the colder air mass lagging behind some as the low level flow turns
more north-northeast for a time on Friday, with the bigger push of
much colder air more south than east. But that will change later
tomorrow afternoon and evening as the boundary shifts well off to
our east and cold high pressure settles in from the west. As far
as precip is concerned, forecast soundings to our north continue
to indicate we lose the ice crystals at the cloud top layer by
morning suggesting only a very narrow window of opportunity for
any mix of rain and snow. Just based off the NAM-WRF soundings
it looks more like drizzle than anything else but for now will
hold with the rain-snow mix wording in the grids Friday morning.
Based off the forecast soundings and time height cross sections we
should hold on to the low level moisture/clouds for a time on
Friday. But with the initial push of Arctic air more to our west,
we should see a slow climb in temperatures during the late morning
into the early afternoon hours. The real push of cold air moves
in late in the afternoon and into the overnight hours as the surface
high edges east into the region setting up for a cold and blustery
weekend. A gusty north to northwest wind is expected on Saturdy with
highs struggling to reach 30 in the north and edging into the middle
30s south with wind chills ranging from the teens north to the upper
20s south. With the center of the Arctic air mass pushing right into
central Illinois Sunday morning, look for overnight lows ranging from
around 9 degrees far northwest to the upper teens far southeast. Wind
chills will be in the 5 to 10 degree range. Winds will be quite a bit
lighter on Sunday as Arctic high pressure moves slowly across central
Illinois, but afternoon temperatures will be slow to recover from the
early morning chill with readings mostly in the 20s.
LONG TERM...Monday through Thursday
Split upper flow pattern forecast into early next week with model
differences still seen with respect to how strongly the northern
stream wave amplifies across the Great Lakes starting on Tuesday.
The GFE remains the least amplified, and as a result, does not
bring as much cold air south into our area, while the ECMWF and UK
models were much more amplified with the northern stream, resulting
in another push of Arctic air south into our area by mid-week. The
latest GFS ensemble mean has trended a bit more amplified with the
northern stream by late Tuesday into early Wednesday, before the
flow quickly deamplifies after Wednesday. We have seen this type of
scenario before with the models this fall season with the ECMWF usually
the most aggressive with the push of cold air south, while the GFS
has been quite a bit more conservative with respect to how deep the
upper trofs become off to our east. So far, the GFS has done a better
job with respect to verifying the amount of cold air spilling south
into our area.
As far as precip is concerned, with a return flow setting up across
the region on Monday. The combination of moisture from the southwest
cutoff low and a northern stream wave and associated frontal boundary
approaching from the northwest, warrants at least a slight chance for
light snow in the morning, and the possibility for a light snow and
rain mix in the afternoon. After that, we start to see some significant
differences with the models with again, the ECMWF more aggressive with
the northern stream and actually shows a phases soultion with the
southwest cutoff low by Tuesday of next week, opening up the cold air
flood gates once more. The GFS is quite a bit less amplified with
no phasing indicated late Tuesday into Wednesday. For now, will not
make any significant changes to the extended with temperatures still
expected to average well below normal thru the week with the most
significant threat for widespread precip over the lower Mississippi
valley, and then up the East coast late Tuesday night through
Thanksgiving day.
Smith
&&
.AVIATION...
ISSUED 1144 AM CST Thu Nov 21 2013
An area of rain is currently pushing into central Illinois from
the southwest and will overspread the entire area over the next
1 to 2 hours. While VFR ceilings are initially present as the rain
first begins, upstream obs and latest HRRR data both suggest
ceilings dropping to IFR later this afternoon into tonight.
Steadiest rains and lowest ceilings will generally be focused
along and south of a KIJX to KBMI line, meaning the period of IFR
ceilings will be a bit shorter at KPIA than the other central
Illinois terminals. As a cold front pushes eastward across the
state overnight, ceilings will climb back into the MVFR category
after 10z at KPIA, then after 13z further east at KCMI. Winds will
initially be southerly this afternoon, then will go light/variable
this evening. Once front passes, strong northwesterly winds
gusting over 20kt will develop by Friday morning.
Barnes
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1224 PM CST THU NOV 21 2013
.DISCUSSION...
303 AM CST
PERIODS OF PRECIP AND FALLING TEMPS WILL BE THE FOCUS FOR THE NEXT
SEVERAL DAYS. WATER VAPOR IMAGERY SHOWS VERY BROAD TROUGHING OVER
THE CONUS WITH THE LOCAL AREA UNDERNEATH THE BELT OF SOUTHWESTERLY
FLOW EAST OF THE TROUGH AXIS. SEVERAL WAVES CONTINUE TO TRAVERSE
THIS FLOW...ONE OF WHICH HAS DEPARTED TO THE NORTHEAST WITH ANOTHER
MOVING ACROSS SOUTHERN ILLINOIS AND A THIRD MOVING ACROSS EASTERN
KANSAS/OKLAHOMA AND SOUTHWEST MISSOURI. ON THE LARGER SCALE...A LOW
CIRCULATION OVER CALIFORNIA/NEVADA IS IN THE PROCESS OF CUTTING OFF
FROM A STRONGER STREAM OVER BRITISH COLUMBIA. AT THE SURFACE...AN
EXPANSIVE AREA OF HIGH PRESSURE IS OVER NORTHERN NEW ENGLAND WITH A
RIDGE AXIS EXTENDING DOWN TO THE FLORIDA PANHANDLE. AN INVERTED
TROUGH AXIS IS STRETCHED FROM THE SOUTHERN PLAINS TO THE ARROWHEAD
OF MINNESOTA WITH A 1040 MB HIGH STRENGTHENING AS IT SPREADS INTO
THE NORTHERN HIGH PLAINS.
TODAY THROUGH FRIDAY...THE SURFACE INVERTED TROUGH CURRENTLY ACROSS
IOWA WILL BE SHIFTING EASTWARD TODAY AND SHOULD BE EAST OF THE CWA
LATER TONIGHT. THE TROUGH WILL REMAIN FAIRLY WEAK AS IT AFFECTS THE
AREA GIVEN THAT PHASING BETWEEN THE AMPLIFYING UPPER TROUGH MOVING
INTO THE NORTHERN PLAINS AND THE WAVES TRAVERSING THE SOUTHWESTERLY
FLOW NOW OVER THE LOCAL AREA IS NOT MATERIALIZING. THE FOCUS FOR
PRECIPITATION WILL BE MORE CLOSELY TIED TO THE AFOREMENTIONED
SHORTWAVES UPSTREAM OF THE AREA AND A STRENGTHENING MID LEVEL
BAROCLINIC ZONE. RADAR MOSAIC SHOWS A CORRIDOR OF RAIN SHOWERS FROM
SOUTHERN ILLINOIS NORTHEAST TO LAKE ERIE TIED TO THE DEPARTING WAVE
TO THE EAST AND THE WAVE MOVING ACROSS SOUTHERN ILLINOIS. THE TAIL
END OF THIS WAVE MAY HELP TO PUSH SHOWER ACTIVITY INTO THE FAR
SOUTHEAST CWA THIS MORNING. AS THE KS/OK/MO WAVE WORKS IN LATER THIS
AFTERNOON THE PRECIP SHIELD LOOKS TO SPREAD ACROSS THE REST OF THE
AREA WHICH WILL BE ABOUT THE TIME THAT THE SURFACE TROUGH AXIS
CROSSES THE AREA. EXPECT THE BULK OF THE PRECIP TO FALL ACROSS THE
SOUTHEAST HALF TO TWO-THIRDS OF THE AREA THROUGH THIS EVENING...WITH
THE MOST WIDESPREAD COVERAGE LIKELY OCCURRING LATE THIS AFTERNOON
THROUGH THE EVENING. ONCE THE LAST OF THE MAIN WAVES DEPARTS THIS
EVENING PRECIP COVERAGE BECOMES MORE OF A CHALLENGE BUT WILL
PROBABLY DIMINISH LATE THIS EVENING OR EARLY TONIGHT. THE UPPER
TROUGH NOW WORKING INTO THE NORTHERN PLAINS WILL BE WORKING EAST
PUSHING COLDER AIR SOUTHEAST WITH IT FRIDAY MORNING. THE COLD
ADVECTION MAY BE ABLE TO WRING OUT SOME ADDITIONAL SHOWERS AS IT
SPREADS IN FRIDAY WITH RESIDUAL MOISTURE STILL IN PLACE. FORCING AND
MOISTURE REALLY DROP OFF DURING THE AFTERNOON OR EVEN BY AFTERNOON
SO WILL HASTEN THE DECREASE IN POPS WITH MOST IF NOT ALL AREAS DRY
BY AFTERNOON. WITH THE FALLING MID LEVEL TEMPS...ANY RAIN ACTIVITY
WILL TRY TO MIX WITH SNOW AS THE COLD AIR ARRIVES BUT IT MAY BE THAT
PRECIP ENDS BEFORE THIS REALLY HAS A CHANCE TO OCCUR. HIGHS TODAY
WILL BE IN THE UPPER 40S TO NEAR 50 WITH HIGHS FRIDAY LIKELY
OCCURRING DURING THE MORNING WITH UPPER 30S NORTHWEST AND MID 40S
SOUTHEAST...WITH FALLING TEMPS DURING THE AFTERNOON.
SATURDAY AND SUNDAY...ANOTHER WAVE WILL BE MOVING DOWN THE WESTERN
PORTION OF THE UPPER TROUGH HELPING TO AMPLIFY IT AND BRINGING A
SECOND PUSH OF COLD AIR SATURDAY MORNING. A 1042+MB HIGH WILL BE
BUILDING INTO THE PLAINS WITH BREEZY NORTHWEST WINDS DEVELOPING TO
ITS EAST ACROSS THE LOCAL AREA. WITH H85 TEMPS FALLING TO AROUND
-16C SURFACE TEMPS WILL HAVE A HARD TIME WARMING FROM THEIR MORNING
READINGS...WITH HIGHS EXPECTED TO RANGE FROM THE MID/UPPER 20S NORTH
TO AROUND 30/LOWER 30S SOUTH. THE CENTER OF THE HIGH WILL BE
CROSSING CENTRAL ILLINOIS SUNDAY WITH THE RIDGE AXIS CROSSING THE
CWA. THIS WILL ALLOW FOR LITTLE MIXING FOR MOST OF THE DAY THOUGH A
LIGHT SOUTHWEST WIND MAY SET UP LATER IN THE DAY. H85 TEMPS WILL BE
WARNING TO AROUND -6 TO -8C BY LATE DAY AS THE UPPER TROUGH AXIS
MOVES TO THE EAST AND LOW AMPLITUDE UPPER RIDGING BRINGS WARM
ADVECTION BACK TO THE MID AND UPPER MISSISSIPPI RIVER VALLEY AND
WESTERN GREAT LAKES. WILL CONTINUE WITH HIGHS MAINLY IN THE MID 20S
DESPITE THE WARMING ALOFT DUE TO THE WEAK MIXING AND NEED TO REBOUND
FROM MORNING READINGS IN THE TEENS.
MONDAY THROUGH WEDNESDAY...A TROUGH WILL MOVE SOUTHEAST ACROSS
CENTRAL CANADA SHUNTING THE UPPER RIDGING TO THE EAST SUNDAY NIGHT
AND MONDAY WITH THE PASSAGE OF THE TROUGH AXIS POSSIBLY BRINGING
SOME SNOW SHOWERS DURING THE DAY MONDAY. A SOUTHWEST WIND AND H85
TEMPS AROUND -3 OR -4C SHOULD ALLOW TEMPS TO RECOVER INTO THE MID
30S. GUIDANCE IS AT ODDS FROM TUESDAY ONWARD WITH THE HANDLING OF
THE CUTOFF LOW /THE ONE CUTTING OFF OVER SOUTHERN CALIFORNIA TODAY
AND TOMORROW/ AND POTENTIAL PHASING WITH THE NORTHERN STREAM TROUGH.
CONFIDENCE IS LOW IN WHETHER TEMPS REMAIN NEAR MONDAYS VALUES OR
COOL OFF ONCE AGAIN THANKS TO DISCREPANCIES ON WHETHER A SECOND
TROUGH TRAILS THE MONDAY TROUGH BRINGING ANOTHER PUSH OF COLD AIR OR
NOT.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS LOWERING TO IFR THIS EVENING.
* -RA THIS AFTN TAPERING TO -DZ THIS EVENING.
* GUSTY N WINDS OVERNIGHT THROUGH FRIDAY.
* -RA RETURNS EARLY FRIDAY MORNING AND CHANGES OVER TO -RASN BY
MID MORNING...AND ENDS LATE MORNING/EARLY AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE IS OVER SOUTHERN ONTARIO WITH ITS COLD FRONT SLOWLY
APPROACHING NORTHERN IL FROM THE NW. THE COLD FRONT STRETCHES FROM
MILWAUKEE TO DUBUQUE WITH LIGHT WINDS JUST AHEAD OF IT. NW TO N
WINDS AND IFR TO LIFR CIGS ARE BEHIND THE FRONT. A WEAK UPPER
LEVEL DISTURBANCE IS ALSO PUSHING INTO SOUTHERN IL AND EXPECTING
THE PRECIP TO OUR SOUTH TO PUSH NORTH AHEAD OF THE DISTURBANCE.
THERE IS STILL A BIT OF UNCERTAINTY ABOUT HOW FAR NORTH THE PRECIP
WILL REACH. KEPT PRECIP AT ALL OF THE EASTERN TERMINALS BUT
DOWNGRADED RFD TO VCSH BECAUSE I THINK -RA WILL REMAIN JUST TO
ITS SOUTH. ATMOSPHERIC MOISTURE REMAINS PLENTIFUL SO CONTINUED -DZ
THROUGH THE EVENING AT ALL LOCATIONS...AND THROUGH THE MORNING AT
RFD.
CIGS HAVE BEEN DIFFICULT AS THE LOWER CIGS OVER IA AND WI HAVE NOT
BUDGED THIS MORNING. THEREFORE TIMING WHEN IF AND WHEN THEY WILL
MOVE INTO ORD HAS BEEN EXTREMELY DIFFICULT. A FEW SOUTHERN WI
SITES HAVE FINALLY REGISTERED IFR CIGS SO USED THAT TO GET THE
TIMING FEATURED IN THE TAFS. THINKING THE LOWER CIGS WILL BE TIED
TO THE PRECIP...AND IFR CIGS ARE ASSOCIATED WITH THE FRONTAL
PASSAGE. CONFIDENCE IS HIGH THAT CIGS WILL FALL...BUT LOW AS FAR
AS WHEN. ALSO KEPT LIFR OUT OF MOST OF THE TAFS DUE TO A LACK OF
CONFIDENCE...BUT LOOKING UPSTREAM THEY ARE STILL POSSIBLE.
WINDS WILL GO LIGHT AND VARIABLE AHEAD OF THE FRONT AND THEN
BECOME NNE ARND 6KT IMMEDIATELY BEHIND THE FRONT. THE GRADIENT
CONTINUES TO TIGHTEN WITH N WINDS 15G20+ KT BY FRIDAY MORNING.
RAIN ALSO RETURNS AHEAD OF THE UPPER LEVEL TROUGH AXIS. COLD AIR
MOVES IN AND PRECIP WILL BECOME A RAIN/SNOW MIX BY MID MORNING.
MAY SEE A BRIEF PERIOD OF SNOW NEAR THE END OF THE PRECIP IN THE
LATE MORNING/EARLY AFTERNOON BUT SOUNDINGS INDICATE ICE CRYSTALS
MAY NOT BE PRESENT SO ALL SNOW WILL BE DIFFICULT. NO ACCUMULATION
IS EXPECTED AT THIS TIME BUT SLICK RUNWAYS ARE LIKELY. VSBY COULD
BE MORE REDUCED THAN INDICATED BUT CIGS SHOULD BE ON A SLOW RISE.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIG TRENDS...MEDIUM-LOW CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN LIFR CIGS FORMING.
* HIGH CONFIDENCE IN PRECIP THIS EVENING AND TOMORROW...MEDIUM
CONFIDENCE IN TIMING AND CHANGE OVER TO -RASN.
* MEDIUM CONFIDENCE IN VSBY ASSOCIATED WITH PRECIP.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT...DRY/VFR.
* SATURDAY...DRY/VFR. STRONG/GUSTY NORTHWEST WINDS.
* SUNDAY...DRY/VFR.
* MONDAY...CHANCE OF RAIN/SNOW SHOWERS. MVFR POSSIBLE.
* TUESDAY AND WEDNESDAY...DRY/VFR.
&&
.MARINE...
318 AM...A COLD FRONT WILL MOVE SOUTH ACROSS THE NORTHERN PART OF
LAKE MICHIGAN THIS EVENING AND THEN MOVE SOUTH OF THE LAKE BY
FRIDAY MORNING. WINDS WILL SHIFT NORTHERLY BEHIND THE FRONT AND
INCREASE TO 30KTS. THERE APPEARS TO BE A SHORT PERIOD IMMEDIATELY
BEHIND THE FRONT WHERE GUSTS COULD REACH LOW END GALES. AT THIS
POINT...NOT SURE HOW LONG THAT PERIOD MAY LAST AND HAVE OPTED TO
INCLUDE JUST GALE GUST WORDING WITH THIS FORECAST. STRONG HIGH
PRESSURE WILL SURGE SOUTH ACROSS THE PLAINS TONIGHT INTO FRIDAY
WHILE ANOTHER STRONGER HIGH SPREADS ACROSS SOUTH CENTRAL CANADA.
IN BETWEEN THESE TWO SYSTEMS...A TROUGH OF LOWER PRESSURE WILL
MOVE ACROSS THE NORTHERN LAKES LATE FRIDAY NIGHT AND SLOWLY DEEPEN
AS IT MOVES ACROSS THE EASTERN LAKE SATURDAY. NORTHERLY WINDS WILL
SLOWLY DIMINISH FRIDAY AFTERNOON...THEN SHIFT WESTERLY...PERHAPS
BRIEFLY SOUTHWESTERLY...AHEAD OF THIS TROUGH. AS IT SHIFTS EAST...
THE TWO HIGH PRESSURE SYSTEMS WILL MERGE INTO ONE SPRAWLING HIGH
OVER THE PLAINS FRIDAY NIGHT INTO SATURDAY. THE GRADIENT WILL
TIGHTEN BEHIND THE DEPARTING TROUGH AND THIS STRONG HIGH. WINDS
WILL SHIFT NORTHWEST FRIDAY NIGHT AND INCREASE TO GALES BY
SATURDAY MORNING WITH A PERIOD OF 40KTS IN THE MORNING ESPECIALLY
ACROSS THE NORTH HALF. THE WINDS WILL SLOWLY DIMINISH BY SATURDAY
EVENING AND CONTINUE DIMINISHING SATURDAY NIGHT. AIR TEMPERATURES
ARE EXPECTED TO FALL INTO THE MID TO UPPER 20S BY SATURDAY EVENING
AND LIKELY REMAIN IN THE LOWER TO MID 20S FOR MUCH OF SATURDAY
NIGHT. ITS POSSIBLE THERE COULD BE SOME FREEZING SPRAY BUT WITH
WATER TEMPERATURES STILL IN THE MID 40S...CONFIDENCE IS TOO LOW TO
INCLUDE ANY MENTION WITH THIS FORECAST.
THE HIGH WILL SLOWLY WEAKEN AS IT MOVES SOUTHEAST TO THE OHIO
VALLEY SUNDAY AND TO THE MID ATLANTIC MONDAY. A WEAKER RIDGE
AXIS EXTENDING NORTH WILL CROSS LAKE MICHIGAN SUNDAY AFTERNOON
SHIFTING WINDS TO THE SOUTHWEST. ANOTHER LOW PRESSURE WILL MOVE
ACROSS SOUTH CENTRAL ONTARIO AND THE NORTHERN LAKES SUNDAY NIGHT
INTO MONDAY. THE GRADIENT WILL TIGHTEN QUICKLY SUNDAY EVENING
WITH SOUTHWEST GALES DEVELOPING SUNDAY NIGHT...TURNING WESTERLY
MONDAY WITH THE GALES DIMINISHING MONDAY AFTERNOON INTO MONDAY
EVENING. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...4 AM FRIDAY TO 6 AM SATURDAY.
&&
$$
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
1144 AM CST Thu Nov 21 2013
.DISCUSSION...
ISSUED 1041 AM CST Thu Nov 21 2013
Nearly stationary frontal boundary extending from far northern
Illinois southwestward to the Texas panhandle will serve as the
primary focusing mechanism for rain today and tonight. Short-wave
trough evident on 16z/10am water vapor imagery over Kansas/Oklahoma
will track along the boundary this afternoon, providing enhanced
synoptic lift. As a result, expect rain to become widespread across
all of central and southeast Illinois as the day progresses.
Upstream obs have shown mainly rain: however, a few lightning
strikes were observed earlier in southwest Missouri. Will
therefore maintain isolated thunder wording across the southern
half of the KILX this afternoon. Despite a light southerly wind,
extensive cloud cover and precip will keep high temperatures
mainly in the lower 50s. Forecast update will be issued shortly.
Barnes
&&
.AVIATION...
ISSUED 1144 AM CST Thu Nov 21 2013
An area of rain is currently pushing into central Illinois from
the southwest and will overspread the entire area over the next
1 to 2 hours. While VFR ceilings are initially present as the rain
first begins, upstream obs and latest HRRR data both suggest
ceilings dropping to IFR later this afternoon into tonight.
Steadiest rains and lowest ceilings will generally be focused
along and south of a KIJX to KBMI line, meaning the period of IFR
ceilings will be a bit shorter at KPIA than the other central
Illinois terminals. As a cold front pushes eastward across the
state overnight, ceilings will climb back into the MVFR category
after 10z at KPIA, then after 13z further east at KCMI. Winds will
initially be southerly this afternoon, then will go light/variable
this evening. Once front passes, strong northwesterly winds
gusting over 20kt will develop by Friday morning.
Barnes
&&
.PREV DISCUSSION...
ISSUED 228 AM CST Thu Nov 21 2013
Showers have been scattered over about the southeast half of the
forecast area the last few hours, with regional radar imagery at 2
am showing a sizable break in the rain across much of Missouri.
Latest surface map showed low pressure over the Texas panhandle,
with a frontal boundary arcing northeast to link up with a cold
front across central Minnesota and western Iowa. Water vapor
imagery over the last few hours has shown the split upper flow
taking better hold as a trough digs across California, and another
trough over eastern Saskatchewan in the northern stream. This
split flow will play a big part in the arrival of a couple shots
of very cold air over the next week.
SHORT TERM...Today through Friday:
Cold front will get a healthy kick eastward later today, as the
two upper streams interact somewhat over the Plains. Another surge
of moisture will stream northeast into the forecast area, and will
maintain categorical rain chances over about the southeast 2/3 of
the CWA by afternoon. Cannot rule out a rumble or two of thunder,
but that should be few and far between. The front should push
through the CWA tonight, with the brunt of the precipitation more
toward the Ohio River by sunrise, but am expecting some post-
frontal rain to linger over the southeast at least into early
afternoon.
LONG TERM...Saturday through Wednesday:
Arctic air will plunge over the Great Lakes region this weekend,
bringing the coldest air of the season to central Illinois. 850 mb
temps of -14C expected Saturday night. Northwest CWA will struggle
to reach freezing Saturday, and much of the area will only be
around 30 for Sunday. A fairly stiff northwest wind is expected as
strong Canadian high pressure moves in, resulting in wind chills
in the single digits by Sunday morning.
The high pressure will exit to our southeast Sunday night as the
next storm system approaches from the northern Plains. Longer
range models remain agreeable with a storm system developing over
the Gulf in response to the large cutoff low in the southern
stream finally ejecting eastward, and that will prevent meaningful
moisture return to aid the northern front. Will see some light
snow with this front on Monday, perhaps mixing with some afternoon
rain, but only a dusting of accumulation expected.
Longer range models experiencing some timing differences in
how far to plunge the next Arctic outbreak southward. The GFS
keeps us relatively mild with the ECMWF remaining much more
aggressive, with 850 mb temperatures ranging from zero to -15C
by midweek. The discrepancy is because the GFS is much slower with
the progression of the closed low over the southeast U.S., helping
to bottle the cold air mass much further north. Have not made much
change to the forecast at this point, which had been trending toward
the colder solution. However, both are in agreement with dry
weather for the pre-Thanksgiving travel rush in the immediate area.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
303 PM CST Thu Nov 21 2013
.SHORT TERM...(This Evening through Friday)
Issued at 256 PM CST THU NOV 21 2013
.Synopsis...
Water vapor imagery shows a shortwave trough over the northern
plains propagating east towards the great lakes, while energy
begins to cut off over central CA. At the surface, a strong cold
front has pushed through the entire forecast area with
temperatures continuing to fall in response to strong cold air
advection.
.Short Term... (Tonight)
For tonight the forcing for continued precipitation looks to be
mainly driven by mid level frontogenesis. The NAM and RAP progs
show weakening isentropic upglide early in the evening as the 850
front continues to push south. Then by the late evening and
overnight mid level drying near the better mid level
frontogenetical forcing suggests that precip could come to an end
since there is no lift within the low level cloud from isentropic
features for light freezing drizzle. With this in mind have
trended POPs down for most areas overnight. The latest
HRRR/RAP13/NAM12 continue to show this band of precip currently
from Minneapolis to Hiawatha, associated with some mid level
frontogenesis, to lift northeast into northwest MO. Therefore have
some likely pops for the early evening across far northeast KS.
Otherwise the forecast will only have some chance pops through the
rest of tonight. Did not feel confident enough to lower pops any
further since there will be some mid level frontogenesis through
the night. Also will not make any major changes to the advisory
other than to end it earlier in the day Friday. It is one of those
situations that with the advisory already out it doesn`t make
sense to cancel it early since there remains the potential for
some light frozen precip with reports of slick roads coming in.
Since forcing is weak and moisture will continue to lessen through
the night, additional precipitation is anticipated to be on the
light side with accumulations generally around a tenth of an inch in
water equivalent. The mid level drying will also make it difficult
for snow to occur since the dendritic growth zone is not expected to
be saturated. Because of this there shouldn`t be any ice crystals
for snow. So think freezing rain and sleet will be the primary
precip type through the night if precip does fall. Continued cold
air advection should cause temperatures to fall into the teens and
mid 20s for the forecast area by sunrise Friday.
.LONG TERM...(Friday Night through Thursday)
Issued at 256 PM CST THU NOV 21 2013
Friday...Becomes a race with the incoming drier air as to how much
precipitation can fall on Friday as high pressure continues to surge
into the southern plains through the day. Back to the west an upper
low advances into Baja, lifting a lobe of moisture into southern
Kansas in the mid levels. Frontogenesis gets some further
enhancement from northern trof dropping energy into the area mid to
late day. Isentropic charts indicate downglide in the lower levels,
with 700mb chart showing some broad convergence in the wind field
through the noon hour. With lack of strong lift and incoming drier
air have pulled back on precip chances and amounts but not ready to
remove entirely for the southern counties just yet. Enough
consensus in incoming dry air from north to end the advisory earlier
for generally the I70 counties, but will hang onto it through noon
for those south of I70. Temperature profiles are finally cold enough
for all snow along the northern edge but hold onto a weak warm nose
across the SE and will keep a S/IP mix for these areas. Went colder
on both highs and lows given current reflection in observations with
highs upper 20s to near freezing and dropping overnight into the
upper teens.
Saturday and Sunday... Continue to go on the cool side of guidance
on Saturday with high pressure still on the move to the south. Have
highs near freezing and lows in the lower to middle teens. Incoming
clouds from the southwest on Sunday plus a return to southerly
surface low on the wrn side of the high should bring highs back into
the middle 30s on Sunday.
Monday: An upper level trough forming out of the Four Corners region
will propagate to the east. The 12Z ECMWF/GFS are in reasonable
agreement pertaining to the location of the trough. A jet streak of
up to 100kt winds associated with this trough should eject
additional moisture into Oklahoma and Kansas. Southerly winds in
this region should help support moisture transfer over eastern
Kansas. This additional moisture, along with freezing temperatures,
could support light snow over eastern Kansas.
By Tuesday, the trough should pivot to the south due to a ridging
stream wave over the western CONUS. The trough should stay further
south into Texas and Oklahoma. Winds shift from southerly to
northerly as the trough moves south. The ridging pattern over the
western CONUS will translate towards the east by Wednesday, bringing
quiet weather to the region. Lows will be in the 20s overnight and
highs will be in the upper 30s/lower 40s for the rest of the week.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1121 AM CST THU NOV 21 2013
Think CIGS and VSBY could bounce around between IFR and MVFR
through this evening. Forcing for precip looks to be weak such
that precip intensity should remain light through the evening so
do not anticipate LIFR or VLIFR conditions at this time. Think
precip type is likely to remain FZRAPL. See the updated discussion
for further details. With the quicker frontal timing and cold air
moving south, will start freezing precip a little sooner at the
terminals. Also with dry air working in overnight from the north,
will bring an end to precip sooner as well which should also allow
VSBY to improve. Models show CIGS gradually improving by mid
morning Friday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 6 AM CST Friday FOR KSZ008>012-
020>024-026-034>036-038-039.
WINTER WEATHER ADVISORY from 6 PM this evening to 6 AM CST
Friday FOR KSZ040.
WINTER WEATHER ADVISORY until Noon CST Friday FOR KSZ037.
WINTER WEATHER ADVISORY from 6 PM this evening to Noon CST
Friday FOR KSZ054>056-058-059.
&&
$$
SHORT TERM...67/Wolters
LONG TERM...67/JTS
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1121 AM CST Thu Nov 21 2013
...AVIATION UPDATE...
.UPDATE...
Issued at 1034 AM CST THU NOV 21 2013
Updated the forecast to go with a quicker trend in bringing the
cold air south behind the front. Also tweaked pops for this
afternoon and tonight to follow latest trends in short term model
trends.
Forcing...
NAM and RAP progs continue to show isentropic lift and weak moisture
advection up over the shallow layer of cold air. In addition the
higher resolution models suggest a band of precip forming by mid
afternoon across northern KS in response to a band of mid level
frontogenesis. However by the early evening the low level
isentropic lift dissipates along with any weak moisture advection and
the layer where the stronger frontogenetical forcing starts to dry
out. because of this have trended pops down for the late night
hours.
Precip type...
Model forecast soundings do not have much saturation in the
dendritic growth zone for ice crystals. The one exception may be
across far north central KS during the late afternoon where the
cold air may be deep enough with some saturation in the dendritic
growth zone for a brief period of snow. Otherwise the forecast
anticipates mainly light freezing rain as surface temps continue
to fall through the day. Sleet should become mixed in with any
freezing rain as the shallow cold air approaches -10C allowing for
any supper cooled water to freeze before hitting the ground.
&&
.SHORT TERM...(Today and Tonight)
Issued at 517 AM CST THU NOV 21 2013
The main focus for the short term is on the approaching system that
will bring a wintry mix of precipitation to the forecast area. Early
this morning, another embedded shortwave skimmed across southern
Kansas. The combination of an increasing mid-level jet advecting more
moisture into the region and decent isentropic lift in the 300K-315K
layer resulted in the development of scattered showers and a few
isolated thunderstorms across northern Oklahoma and southern Kansas
early this morning. At 11z, this activity was beginning to lift
northward into central Kansas. This precipitation will continue to
spread across much of the outlook area through the day with
scattered areas of precipitation persisting through the evening and
overnight hours.
The main focus with this activity will be precipitation type as
plummeting temperatures will result in the development of a wintry
mix. Early this morning, a mid-level trough continued to dig
southward across Canada and into the Northern Plains, ultimately
helping to push a cold front into the region. As of 11z, this cold
front had already advanced into north central Kansas with regional
observation sites showing breezy northerly winds behind this front
advecting much colder air into the area. In fact, temperatures had
already dropped into the mid 30s in north central Kansas with
readings in the teens and 20s across much of Nebraska. This cold air
will overspread the forecast area today as the cold front tracks
southeast of the area by this afternoon. As a result, went with a
non-diurnal trend for temperatures today as most locations will see
temperatures steadily dropping through the day. High temperatures
will range from the lower 50s over east central Kansas down into the
middle 30s over north central Kansas. These plummeting temperatures
combined with scattered precipitation today through tonight will
result in a mixed bag of precipitation types. Over eastern Kansas,
temperatures should stay above freezing through the daytime hours
and keep precipitation in the form of light rain through this
afternoon and into early this evening. However, across north central
Kansas, temperatures are expected to drop into the middle 20s to
middle 30s through the day. Model soundings have consistently been
showing a prevailing warm nose of roughly +3C to +5C this afternoon
in that region, with saturation diminishing within the dendritic
growth zone. These features combined with dropping surface
temperatures will result in areas of light freezing rain, freezing
drizzle and/or sleet developing late this morning through this
afternoon across locations generally along and west of a line
stretching from Marysville to Manhattan and Council Grove. As
temperatures continue to plummet across eastern Kansas, expect to
see this mix of light freezing rain/drizzle and sleet shift into
northeast Kansas tonight. Locations generally southeast of I-35
likely won`t see this transition from rain to mixed wintry precip
until around midnight. Across north central Kansas, model soundings
show the warm nose diminishing this evening, so the loss of this
warmer air aloft combined with dropping surface temperatures will
result in the precipitation type transitioning over toward a mix of
sleet and snow before eventually becoming all snow by around 9pm
over far north central Kansas and closer to midnight over much of
northern and north central Kansas. Overnight low temperatures will
ultimately bottom out in the upper teens to upper 20s from northwest
to southeast over the CWA.
While several wintry precipitation types are expected with this
system, the one thing it lacks is abundant moisture. As a result,
much of the region will likely see a prolonged period of just light
precipitation. Snow accumulations over north central Kansas are
expected to be less than one inch and less than one-half inch over
east central Kansas. Ice accumulations are also expected to be light
at less than one-tenth inch. However, this light precipitation could
still be enough to cause slick road conditions across the region,
especially on bridges and overpasses. As a result, have extended the
Winter Weather Advisory to cover the entire outlook area by tonight.
One very noteworthy trend with the 00z model runs is the speed at
which the drier air moves into the area as surface high pressure
advances southward along the lee-side of the Rockies. The
GFS/ECMWF/GEM are all in agreement in having this precipitation
diminishing over north central Kansas after 06z with much of the
forecast area shown as being dry by around 12z Friday. However, both
the 00z and 06z runs of the NAM are much slower with the progression
of the dry air and keep precipitation across much of the CWA into
Friday morning. Considering the combination of these model trends
and current observations further north of the CWA, have trended more
with the progressive dry-air solutions of the GFS/ECMWF/GEM and thus
have trended downward with the PoPs after midnight, especially
across north central Kansas.
.LONG TERM...(Friday through Wednesday)
Issued at 517 AM CST THU NOV 21 2013
Southwest to zonal flow will be present across the Central Plains on
Friday. A northern Plains upper trough with energy extending south
into the Central Plains will move east into the Great Lakes and
Ontario Province by 00Z Saturday. The cold air depth increases
through the day on Friday. Drier air will move south into Kansas by
afternoon, effectively ending light snow in the northern counties.
Forecast soundings from models show a wintry mix as dry air aloft
will keep the dendritic snow growth portion of the sounding
unsaturated. So expect to see some periods of freezing drizzle,
freezing rain and sleet will all be possible at one time or another.
The GFS and ECMWF are much drier than the NAM with the moisture
profiles. Have gone with a compromise with them for this forecast.
With drier air advecting into northern Kansas in the afternoon
expect precipitation along the Nebraska border to come to an end
while light precipitation is expected to continue across east
central Kansas into the afternoon hours. Temperatures will be near
or below freezing through the day. Models show the the warm nose
around 850 MB to 800 MB going away by late afternoon in east central
Kansas and could see a brief period of light snow before sunset.
Cold arctic air will spread eastward across eastern Kansas with lows
dropping down into the teens to lower 20s.
For the weekend an upper level low in the southwest begins to move
out into the Southern Plains early next week. This may bring a
chance of the light snow or sleet into northeast and east central
Kansas Sunday night. The Upper low is forecast to move across Texas
then into the Gulf Coast States by mid week. With the low passing
well south it will keep any precipitation well to the south. Highs
int he 30s and 40s will be common with lows in the 20s Sunday
through Wednesday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1121 AM CST THU NOV 21 2013
Think CIGS and VSBY could bounce around between IFR and MVFR
through this evening. Forcing for precip looks to be weak such
that precip intensity should remain light through the evening so
do not anticipate LIFR or VLIFR conditions at this time. Think
precip type is likely to remain FZRAPL. See the updated discussion
for further details. With the quicker frontal timing and cold air
moving south, will start freezing precip a little sooner at the
terminals. Also with dry air working in overnight from the north,
will bring an end to precip sooner as well which should also allow
VSBY to improve. Models show CIGS gradually improving by mid
morning Friday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 9 PM this evening to 9 AM CST
Friday FOR KSZ011-012-023-024-026.
WINTER WEATHER ADVISORY until 9 AM CST Friday FOR KSZ008>010-
020>022-034.
WINTER WEATHER ADVISORY from 9 PM this evening to 3 PM CST
Friday FOR KSZ037>040-054>056-058-059.
WINTER WEATHER ADVISORY until 3 PM CST Friday FOR KSZ035-036.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1035 AM CST Thu Nov 21 2013
.UPDATE...
Issued at 1034 AM CST THU NOV 21 2013
Updated the forecast to go with a quicker trend in bringing the
cold air south behind the front. Also tweaked pops for this
afternoon and tonight to follow latest trends in short term model
trends.
Forcing...
NAM and RAP progs continue to show isentropic lift and weak moisture
advection up over the shallow layer of cold air. In addition the
higher resolution models suggest a band of precip forming by mid
afternoon across northern KS in response to a band of mid level
frontogenesis. However by the early evening the low level
isentropic lift dissipates along with any weak moisture advection and
the layer where the stronger frontogenetical forcing starts to dry
out. because of this have trended pops down for the late night
hours.
Precip type...
Model forecast soundings do not have much saturation in the
dendritic growth zone for ice crystals. The one exception may be
across far north central KS during the late afternoon where the
cold air may be deep enough with some saturation in the dendritic
growth zone for a brief period of snow. Otherwise the forecast
anticipates mainly light freezing rain as surface temps continue
to fall through the day. Sleet should become mixed in with any
freezing rain as the shallow cold air approaches -10C allowing for
any supper cooled water to freeze before hitting the ground.
&&
.SHORT TERM...(Today and Tonight)
Issued at 517 AM CST THU NOV 21 2013
The main focus for the short term is on the approaching system that
will bring a wintry mix of precipitation to the forecast area. Early
this morning, another embedded shortwave skimmed across southern
Kansas. The combination of an increasing mid-level jet advecting more
moisture into the region and decent isentropic lift in the 300K-315K
layer resulted in the development of scattered showers and a few
isolated thunderstorms across northern Oklahoma and southern Kansas
early this morning. At 11z, this activity was beginning to lift
northward into central Kansas. This precipitation will continue to
spread across much of the outlook area through the day with
scattered areas of precipitation persisting through the evening and
overnight hours.
The main focus with this activity will be precipitation type as
plummeting temperatures will result in the development of a wintry
mix. Early this morning, a mid-level trough continued to dig
southward across Canada and into the Northern Plains, ultimately
helping to push a cold front into the region. As of 11z, this cold
front had already advanced into north central Kansas with regional
observation sites showing breezy northerly winds behind this front
advecting much colder air into the area. In fact, temperatures had
already dropped into the mid 30s in north central Kansas with
readings in the teens and 20s across much of Nebraska. This cold air
will overspread the forecast area today as the cold front tracks
southeast of the area by this afternoon. As a result, went with a
non-diurnal trend for temperatures today as most locations will see
temperatures steadily dropping through the day. High temperatures
will range from the lower 50s over east central Kansas down into the
middle 30s over north central Kansas. These plummeting temperatures
combined with scattered precipitation today through tonight will
result in a mixed bag of precipitation types. Over eastern Kansas,
temperatures should stay above freezing through the daytime hours
and keep precipitation in the form of light rain through this
afternoon and into early this evening. However, across north central
Kansas, temperatures are expected to drop into the middle 20s to
middle 30s through the day. Model soundings have consistently been
showing a prevailing warm nose of roughly +3C to +5C this afternoon
in that region, with saturation diminishing within the dendritic
growth zone. These features combined with dropping surface
temperatures will result in areas of light freezing rain, freezing
drizzle and/or sleet developing late this morning through this
afternoon across locations generally along and west of a line
stretching from Marysville to Manhattan and Council Grove. As
temperatures continue to plummet across eastern Kansas, expect to
see this mix of light freezing rain/drizzle and sleet shift into
northeast Kansas tonight. Locations generally southeast of I-35
likely won`t see this transition from rain to mixed wintry precip
until around midnight. Across north central Kansas, model soundings
show the warm nose diminishing this evening, so the loss of this
warmer air aloft combined with dropping surface temperatures will
result in the precipitation type transitioning over toward a mix of
sleet and snow before eventually becoming all snow by around 9pm
over far north central Kansas and closer to midnight over much of
northern and north central Kansas. Overnight low temperatures will
ultimately bottom out in the upper teens to upper 20s from northwest
to southeast over the CWA.
While several wintry precipitation types are expected with this
system, the one thing it lacks is abundant moisture. As a result,
much of the region will likely see a prolonged period of just light
precipitation. Snow accumulations over north central Kansas are
expected to be less than one inch and less than one-half inch over
east central Kansas. Ice accumulations are also expected to be light
at less than one-tenth inch. However, this light precipitation could
still be enough to cause slick road conditions across the region,
especially on bridges and overpasses. As a result, have extended the
Winter Weather Advisory to cover the entire outlook area by tonight.
One very noteworthy trend with the 00z model runs is the speed at
which the drier air moves into the area as surface high pressure
advances southward along the lee-side of the Rockies. The
GFS/ECMWF/GEM are all in agreement in having this precipitation
diminishing over north central Kansas after 06z with much of the
forecast area shown as being dry by around 12z Friday. However, both
the 00z and 06z runs of the NAM are much slower with the progression
of the dry air and keep precipitation across much of the CWA into
Friday morning. Considering the combination of these model trends
and current observations further north of the CWA, have trended more
with the progressive dry-air solutions of the GFS/ECMWF/GEM and thus
have trended downward with the PoPs after midnight, especially
across north central Kansas.
.LONG TERM...(Friday through Wednesday)
Issued at 517 AM CST THU NOV 21 2013
Southwest to zonal flow will be present across the Central Plains on
Friday. A northern Plains upper trough with energy extending south
into the Central Plains will move east into the Great Lakes and
Ontario Province by 00Z Saturday. The cold air depth increases
through the day on Friday. Drier air will move south into Kansas by
afternoon, effectively ending light snow in the northern counties.
Forecast soundings from models show a wintry mix as dry air aloft
will keep the dendritic snow growth portion of the sounding
unsaturated. So expect to see some periods of freezing drizzle,
freezing rain and sleet will all be possible at one time or another.
The GFS and ECMWF are much drier than the NAM with the moisture
profiles. Have gone with a compromise with them for this forecast.
With drier air advecting into northern Kansas in the afternoon
expect precipitation along the Nebraska border to come to an end
while light precipitation is expected to continue across east
central Kansas into the afternoon hours. Temperatures will be near
or below freezing through the day. Models show the the warm nose
around 850 MB to 800 MB going away by late afternoon in east central
Kansas and could see a brief period of light snow before sunset.
Cold arctic air will spread eastward across eastern Kansas with lows
dropping down into the teens to lower 20s.
For the weekend an upper level low in the southwest begins to move
out into the Southern Plains early next week. This may bring a
chance of the light snow or sleet into northeast and east central
Kansas Sunday night. The Upper low is forecast to move across Texas
then into the Gulf Coast States by mid week. With the low passing
well south it will keep any precipitation well to the south. Highs
int he 30s and 40s will be common with lows in the 20s Sunday
through Wednesday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 545 AM CST THU NOV 21 2013
For the 12z TAFs, light rain showers will gradually spread northward
into the TAF sites this morning, with CIGS/VIS gradually diminishing
to MVFR conditions this morning and eventually to IFR conditions by
this afternoon. Breezy northerly winds behind the passage of the
cold front will be ushering much colder air into the region today
and tonight, resulting in these light rain showers transitioning
over to a wintry mix of freezing rain/drizzle, sleet, and eventually
light snow this afternoon through Friday morning. Late tonight into the
overnight hours, CIGS/VIS conditions may improve slightly to low-end
MVFR, but will need to continue to monitor the trends with this
precipitation.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 9 PM this evening to 9 AM CST
Friday FOR KSZ011-012-023-024-026.
WINTER WEATHER ADVISORY until 9 AM CST Friday FOR KSZ008>010-
020>022-034.
WINTER WEATHER ADVISORY from 9 PM this evening to 3 PM CST
Friday FOR KSZ037>040-054>056-058-059.
WINTER WEATHER ADVISORY until 3 PM CST Friday FOR KSZ035-036.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1201 PM CST THU NOV 21 2013
.DISCUSSION...
HAVE ISSUED A WINTER WEATHER ADVISORY FROM SOUTHEAST NEB TO
SOUTHWEST/WEST CENTRAL IA. LIGHT FREEZING RAIN IS ACCUMULATING ON
ELEVATED SURFACES...AND EVEN ON SOME ROADWAYS. SLEET HAS BEGUN TO
MIX IN...WHICH WILL AT LEAST PUT A DAMPER ON THE ICING..BUT COULD
ALSO KEEP ROADS ON THE SLICK SIDE. PRECIPITATION SHOULD TRANSITION
TO SLEET AND SNOW THROUGH THE AFTERNOON...BUT OVERALL...RISK OF
HAZARDOUS TRAVEL WAS HIGH ENOUGH IN BAND OF HEAVIEST PRECIPITATION
TO WARRANT A HEADLINE.
MAYES
&&
.PREV DISCUSSION... /ISSUED 1127 AM CST THU NOV 21 2013/
AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK
MESSY CONDITIONS ARE LARGELY FOCUSED ON THE FIRST 12 HOURS OF THE
TAF PERIOD. PERIODS OF MVFR CEILINGS MAY BECOME IFR OR EVEN LIFR
IN SNOWY AREAS LATER THIS EVENING. AT KOMA/KLNK...HAVE INCLUDED A
TEMPO MENTION OF LIGHT FREEZING RAIN FROM 18-20Z...WITH LIGHT
FREEZING RAIN REPORTS IN BOTH METRO AREAS ALREADY...THEN A MIX OF
SLEET AND SNOW LATER THIS AFTERNOON AS PRECIPITATION CHANGES OVER.
MOST LIKELY PERIOD FOR MODERATE SNOWFALL RATES WOULD BE 00-06Z AT
KOMA/KLNK...AND AROUND 22-04Z AT KOFK. GUSTY NORTH WINDS WILL
CONTINUE THROUGH AROUND 06Z AS WELL. SNOW WILL END AND CEILINGS
WILL SCATTER OUT AROUND OR SHORTLY AFTER MIDNIGHT...WITH WINDS
AROUND 12-15KT CONTINUING THROUGH MUCH OF THE NIGHT BEFORE
DIMINISHING IN THE MORNING.
MAYES
PREV DISCUSSION... /ISSUED 1047 AM CST THU NOV 21 2013/
DISCUSSION...
A BAND OF LIGHT PRECIPITATION HAS DEVELOPED IN SOUTHEAST NEBRASKA.
TEMPERATURES ARE FALLING BELOW FREEZING FASTER THAN MOST MODELS
HAD PROGGED...AND HAVE UPDATED TEMPERATURES FOR A FASTER FALL THIS
MORNING...LEVELING OFF SOMEWHAT TODAY BEFORE FALLING AGAIN THIS
EVENING. RAP ANALYSIS INDICATES A WARM NOSE ABOVE THE
SURFACE...WITH ABOVE-FREEZING TEMPERATURES AROUND 850-700 MB STILL
IN PLACE IN MOST AREAS SOUTH OF I-80. UPDATED PRECIPITATION TYPES
TO INCLUDE MORE OF A FREEZING RAIN MENTION IN THE SOUTHEAST
CWA...BEFORE MIXING WITH AND CHANGING TO SLEET IN THE EARLY
TO MID AFTERNOON. REPORTS INDICATE SOME LIGHT ICE ACCUMULATION ON
ELEVATED SURFACES /I.E. WINDOWS AND VEHICLES/ BUT NOT YET ON
ROADS...THUS WILL STICK WITH AN SPS FOR NOW TO HIGHLIGHT THE
BRIEF/LIGHT FREEZING RAIN.
MAYES
PREV DISCUSSION... /ISSUED 423 AM CST THU NOV 21 2013/
DISCUSSION...
THE BULK OF THE WEATHER WILL BE IN THE FIRST 36HRS OF THE
FORECAST WITH THE MAIN FORECAST CONCERNS ONSET OF PRECIPITATION
AND PRECIPITATION TYPE AND SNOWFALL AMOUNTS.
LATEST SATELLITE AND RADAR TRENDS SHOW ENHANCED CLOUDS QUICKLY
LIFTING NORTHEAST THIS MORNING ACROSS KANSAS AND MISSOURI. THE
WSR-88D RADAR HAD A BAND OF RAIN FROM HAYS TO EMPORIA INTO
SOUTHEAST KANSAS...SHIFTING EAST AND LIFTING NORTHEAST. AT THE
SURFACE...ALL SITES HAD NORTH WINDS...WITH THE GUSTY WINDS TO A
NEBRASKA CITY RED OAK LINE. TEMPERATURES WERE IN THE LOWER 20S
NORTH TO 40 SOUTH.
COMPLEX PATTERN TODAY RESULTING FROM SPLIT FLOW REGIME. A SHORTWAVE
TROF ENERGY WITHIN THE LONGWAVE TROF PASSES TO OUR SOUTH THIS
MORNING. 40M HT FALLS WERE NOTED WITH THE CA H5 TROF AND A 100-140KT
JET EXTENDED FROM OFF THE CAL COAST INTO SOUTHERN ARIZONA. THE
FORECAST AREA IS UNDER THE INFLUENCE OF THESE WEATHER
SYSTEMS...HOWEVER THE FORCING IS WEAKER DUE TO THE LACK OF FOCUS.
THIS MORNING...AS THE H3 JET MOVES INTO KANSAS AND MISSOURI...UPPER
LEVEL DIVERGENCE IN THE LEFT EXIT REGION OVER THE AREA QUICKLY MOVES
INTO ILLINOIS BY 18Z. THE H5 LOW CLOSES OFF OVER SOUTHERN CALIFORNIA
THIS AFTERNOON...MEANWHILE...ENERGY FROM THE NORTHERN STREAM MOVES
THROUGH THE NORTHERN PLAINS WITH UPPER LEVEL DIVERGENCE FROM THE
RIGHT ENTRANCE REGION OF THE JET INCREASING OVER THE WESTERN PLAINS.
THERE IS SOME FRONTOGENESIS OVER CENTRAL NEBRASKA THIS
MORNING...THEN LIFTS BACK TO THE NORTHWEST BY MIDDAY...IS FAIRLY
WEAK IN NORTHEAST NEBRASKA THIS AFTERNOON THEN STRENGTHENS AND MOVES
THROUGH THE REST OF THE FORECAST AREA TONIGHT.
HAVE LOWERED POPS FOR MUCH OF THE FORECAST AREA THIS MORNING AS
THE BEST CHANCE FOR MEASURABLE PRECIPITATION LOOKS TO BE SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA. ALTHOUGH THE GFS/EC HAVE SOME TENTH
OF AN INCH PRECIP AMOUNTS IN THE SOUTHEAST NEBRASKA...HI
RESOLUTION HRRR/RAP/NAM ARE A BIT DRIER. THE NAM SEEMED TO HAVE
THE BEST HANDLE ON THE LOW LEVEL TEMPS AND DEWPOINTS. THE GFS/EC
WERE WAY TOO MOIST. FOR THIS PACKAGE LEANED TOWARD THE
NAM/HOPWRF/4KM WRF. HAVE HIGHER POPS SOUTH OF A BEATRICE TO RED
OAK LINE THIS MORNING WITH SLIGHT CHANCES FARTHER NORTH TOWARD
OMAHA. DUE TO THE COLD AIR...FORECAST SOUNDINGS AND TIMESECTIONS
SHOW A MIX OF PRECIP TYPES. WHERE THE PRECIPITATION IS EXPECTED
TO ACCUMULATE...IT SHOULD BE MAINLY RAIN...HOWEVER THERE COULD BE
A MIX FARTHER NORTH IN THE COLDER AIR. DID NOT ISSUE ANY HEADLINES
DUE TO LOW CONFIDENCE IN EXTENT OF ACCUMULATION OF ANY MIXED
PRECIPITATION. NORTHWEST WINDS AT 20 TO 30 MPH SUSTAINED WILL
CONTINUE AND TEMPERATURES WILL NOT GO ANYWHERE...HOLDING MAINLY IN
THE 20S NORTH AND 30S SOUTH.
THIS AFTERNOON...THE COLD AIR WILL BECOME DEEPER AND SNOW IS
EXPECTED TO DEVELOP OVER NORTHERN NEBRASKA WITH THE NORTHERN
STREAM TROF...WITH AREA OF PRECIPITATION OVER FAR SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA SHIFTING EASTWARD. LIGHT SNOW SHOULD
THEN OVERSPREAD THE AREA...MOVING OUT OF THE FORECAST AREA AFTER
06Z. DUE TO THE SHORTER DURATION OF PRECIPITATION HAVE LOWERED
AMOUNTS AND THEY NOW AVERAGE A TRACE TO 1.5 INCHES.
SURFACE HIGH PRESSURE WILL BUILD IN FRIDAY THEN A REINFORCING SHOT
OF COLD AIR SATURDAY. THE ARCTIC FRONT MOVES THROUGH SATURDAY WITH
THE BRUNT OF THE COLD AIR SLIDING TO OUR EAST OVER IOWA AND THE
GREAT LAKES AS THE MID LEVEL TROF DIG INTO THE EASTERN U.S. BY
SUNDAY...SOUTHWEST FLOW WILL RETURN AND TEMPERATURES WILL
RECOVER...BUT WILL REMAIN WELL BELOW NORMAL. THE STORM SYSTEM OVER
THE SOUTHWEST U.S. WILL SHIFT TOWARD THE FOUR CORNERS REGION AND
PRECIP CHANCES MAY BE NEEDED SUNDAY NIGHT INTO MONDAY. ANY
PRECIPITATION LOOKS TO BE LIGHT AND MAY NOT MEASURE. MONDAY ANOTHER
WEAK COLD FRONT MOVES THROUGH WITH A MID LEVEL TROF MOVING THROUGH
THE GREAT LAKES AND THE CLOSE LOW SLOWLY TRACKING ACROSS THE
SOUTHERN PLAINS. THERE ARE SOME AMPLITUDE DIFFERENCE IN THE H5
PATTERN BY WEDNESDAY. THE EC HAS A SHARPENING TROF OVER THE GREAT
LAKES WITH BACKDOOR COOLING...WHILE THE GFS IS FLATTER WITH WARMING
AHEAD OF A WEAK FRONT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NEZ067-
068-088>093.
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ056-
069-079-080-090-091.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1127 AM CST THU NOV 21 2013
.AVIATION...
MESSY CONDITIONS ARE LARGELY FOCUSED ON THE FIRST 12 HOURS OF THE
TAF PERIOD. PERIODS OF MVFR CEILINGS MAY BECOME IFR OR EVEN LIFR
IN SNOWY AREAS LATER THIS EVENING. AT KOMA/KLNK...HAVE INCLUDED A
TEMPO MENTION OF LIGHT FREEZING RAIN FROM 18-20Z...WITH LIGHT
FREEZING RAIN REPORTS IN BOTH METRO AREAS ALREADY...THEN A MIX OF
SLEET AND SNOW LATER THIS AFTERNOON AS PRECIPITATION CHANGES
OVER. MOST LIKELY PERIOD FOR MODERATE SNOWFALL RATES WOULD BE
00-06Z AT KOMA/KLNK...AND AROUND 22-04Z AT KOFK. GUSTY NORTH WINDS
WILL CONTINUE THROUGH AROUND 06Z AS WELL. SNOW WILL END AND
CEILINGS WILL SCATTER OUT AROUND OR SHORTLY AFTER MIDNIGHT...WITH
WINDS AROUND 12-15KT CONTINUING THROUGH MUCH OF THE NIGHT BEFORE
DIMINISHING IN THE MORNING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 1047 AM CST THU NOV 21 2013/
DISCUSSION...
A BAND OF LIGHT PRECIPITATION HAS DEVELOPED IN SOUTHEAST NEBRASKA.
TEMPERATURES ARE FALLING BELOW FREEZING FASTER THAN MOST MODELS
HAD PROGGED...AND HAVE UPDATED TEMPERATURES FOR A FASTER FALL THIS
MORNING...LEVELING OFF SOMEWHAT TODAY BEFORE FALLING AGAIN THIS
EVENING. RAP ANALYSIS INDICATES A WARM NOSE ABOVE THE
SURFACE...WITH ABOVE-FREEZING TEMPERATURES AROUND 850-700 MB STILL
IN PLACE IN MOST AREAS SOUTH OF I-80. UPDATED PRECIPITATION TYPES
TO INCLUDE MORE OF A FREEZING RAIN MENTION IN THE SOUTHEAST
CWA...BEFORE MIXING WITH AND CHANGING TO SLEET IN THE EARLY
TO MID AFTERNOON. REPORTS INDICATE SOME LIGHT ICE ACCUMULATION ON
ELEVATED SURFACES /I.E. WINDOWS AND VEHICLES/ BUT NOT YET ON
ROADS...THUS WILL STICK WITH AN SPS FOR NOW TO HIGHLIGHT THE
BRIEF/LIGHT FREEZING RAIN.
MAYES
PREV DISCUSSION... /ISSUED 423 AM CST THU NOV 21 2013/
DISCUSSION...
THE BULK OF THE WEATHER WILL BE IN THE FIRST 36HRS OF THE
FORECAST WITH THE MAIN FORECAST CONCERNS ONSET OF PRECIPITATION
AND PRECIPITATION TYPE AND SNOWFALL AMOUNTS.
LATEST SATELLITE AND RADAR TRENDS SHOW ENHANCED CLOUDS QUICKLY
LIFTING NORTHEAST THIS MORNING ACROSS KANSAS AND MISSOURI. THE
WSR-88D RADAR HAD A BAND OF RAIN FROM HAYS TO EMPORIA INTO
SOUTHEAST KANSAS...SHIFTING EAST AND LIFTING NORTHEAST. AT THE
SURFACE...ALL SITES HAD NORTH WINDS...WITH THE GUSTY WINDS TO A
NEBRASKA CITY RED OAK LINE. TEMPERATURES WERE IN THE LOWER 20S
NORTH TO 40 SOUTH.
COMPLEX PATTERN TODAY RESULTING FROM SPLIT FLOW REGIME. A SHORTWAVE
TROF ENERGY WITHIN THE LONGWAVE TROF PASSES TO OUR SOUTH THIS
MORNING. 40M HT FALLS WERE NOTED WITH THE CA H5 TROF AND A 100-140KT
JET EXTENDED FROM OFF THE CAL COAST INTO SOUTHERN ARIZONA. THE
FORECAST AREA IS UNDER THE INFLUENCE OF THESE WEATHER
SYSTEMS...HOWEVER THE FORCING IS WEAKER DUE TO THE LACK OF FOCUS.
THIS MORNING...AS THE H3 JET MOVES INTO KANSAS AND MISSOURI...UPPER
LEVEL DIVERGENCE IN THE LEFT EXIT REGION OVER THE AREA QUICKLY MOVES
INTO ILLINOIS BY 18Z. THE H5 LOW CLOSES OFF OVER SOUTHERN CALIFORNIA
THIS AFTERNOON...MEANWHILE...ENERGY FROM THE NORTHERN STREAM MOVES
THROUGH THE NORTHERN PLAINS WITH UPPER LEVEL DIVERGENCE FROM THE
RIGHT ENTRANCE REGION OF THE JET INCREASING OVER THE WESTERN PLAINS.
THERE IS SOME FRONTOGENESIS OVER CENTRAL NEBRASKA THIS
MORNING...THEN LIFTS BACK TO THE NORTHWEST BY MIDDAY...IS FAIRLY
WEAK IN NORTHEAST NEBRASKA THIS AFTERNOON THEN STRENGTHENS AND MOVES
THROUGH THE REST OF THE FORECAST AREA TONIGHT.
HAVE LOWERED POPS FOR MUCH OF THE FORECAST AREA THIS MORNING AS
THE BEST CHANCE FOR MEASURABLE PRECIPITATION LOOKS TO BE SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA. ALTHOUGH THE GFS/EC HAVE SOME TENTH
OF AN INCH PRECIP AMOUNTS IN THE SOUTHEAST NEBRASKA...HI
RESOLUTION HRRR/RAP/NAM ARE A BIT DRIER. THE NAM SEEMED TO HAVE
THE BEST HANDLE ON THE LOW LEVEL TEMPS AND DEWPOINTS. THE GFS/EC
WERE WAY TOO MOIST. FOR THIS PACKAGE LEANED TOWARD THE
NAM/HOPWRF/4KM WRF. HAVE HIGHER POPS SOUTH OF A BEATRICE TO RED
OAK LINE THIS MORNING WITH SLIGHT CHANCES FARTHER NORTH TOWARD
OMAHA. DUE TO THE COLD AIR...FORECAST SOUNDINGS AND TIMESECTIONS
SHOW A MIX OF PRECIP TYPES. WHERE THE PRECIPITATION IS EXPECTED
TO ACCUMULATE...IT SHOULD BE MAINLY RAIN...HOWEVER THERE COULD BE
A MIX FARTHER NORTH IN THE COLDER AIR. DID NOT ISSUE ANY HEADLINES
DUE TO LOW CONFIDENCE IN EXTENT OF ACCUMULATION OF ANY MIXED
PRECIPITATION. NORTHWEST WINDS AT 20 TO 30 MPH SUSTAINED WILL
CONTINUE AND TEMPERATURES WILL NOT GO ANYWHERE...HOLDING MAINLY IN
THE 20S NORTH AND 30S SOUTH.
THIS AFTERNOON...THE COLD AIR WILL BECOME DEEPER AND SNOW IS
EXPECTED TO DEVELOP OVER NORTHERN NEBRASKA WITH THE NORTHERN
STREAM TROF...WITH AREA OF PRECIPITATION OVER FAR SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA SHIFTING EASTWARD. LIGHT SNOW SHOULD
THEN OVERSPREAD THE AREA...MOVING OUT OF THE FORECAST AREA AFTER
06Z. DUE TO THE SHORTER DURATION OF PRECIPITATION HAVE LOWERED
AMOUNTS AND THEY NOW AVERAGE A TRACE TO 1.5 INCHES.
SURFACE HIGH PRESSURE WILL BUILD IN FRIDAY THEN A REINFORCING SHOT
OF COLD AIR SATURDAY. THE ARCTIC FRONT MOVES THROUGH SATURDAY WITH
THE BRUNT OF THE COLD AIR SLIDING TO OUR EAST OVER IOWA AND THE
GREAT LAKES AS THE MID LEVEL TROF DIG INTO THE EASTERN U.S. BY
SUNDAY...SOUTHWEST FLOW WILL RETURN AND TEMPERATURES WILL
RECOVER...BUT WILL REMAIN WELL BELOW NORMAL. THE STORM SYSTEM OVER
THE SOUTHWEST U.S. WILL SHIFT TOWARD THE FOUR CORNERS REGION AND
PRECIP CHANCES MAY BE NEEDED SUNDAY NIGHT INTO MONDAY. ANY
PRECIPITATION LOOKS TO BE LIGHT AND MAY NOT MEASURE. MONDAY ANOTHER
WEAK COLD FRONT MOVES THROUGH WITH A MID LEVEL TROF MOVING THROUGH
THE GREAT LAKES AND THE CLOSE LOW SLOWLY TRACKING ACROSS THE
SOUTHERN PLAINS. THERE ARE SOME AMPLITUDE DIFFERENCE IN THE H5
PATTERN BY WEDNESDAY. THE EC HAS A SHARPENING TROF OVER THE GREAT
LAKES WITH BACKDOOR COOLING...WHILE THE GFS IS FLATTER WITH WARMING
AHEAD OF A WEAK FRONT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1047 AM CST THU NOV 21 2013
.DISCUSSION...
A BAND OF LIGHT PRECIPITATION HAS DEVELOPED IN SOUTHEAST NEBRASKA.
TEMPERATURES ARE FALLING BELOW FREEZING FASTER THAN MOST MODELS
HAD PROGGED...AND HAVE UPDATED TEMPERATURES FOR A FASTER FALL THIS
MORNING...LEVELING OFF SOMEWHAT TODAY BEFORE FALLING AGAIN THIS
EVENING. RAP ANALYSIS INDICATES A WARM NOSE ABOVE THE
SURFACE...WITH ABOVE-FREEZING TEMPERATURES AROUND 850-700 MB STILL
IN PLACE IN MOST AREAS SOUTH OF I-80. UPDATED PRECIPITATION TYPES
TO INCLUDE MORE OF A FREEZING RAIN MENTION IN THE SOUTHEAST
CWA...BEFORE MIXING WITH AND CHANGING TO SLEET IN THE EARLY
TO MID AFTERNOON. REPORTS INDICATE SOME LIGHT ICE ACCUMULATION ON
ELEVATED SURFACES /I.E. WINDOWS AND VEHICLES/ BUT NOT YET ON
ROADS...THUS WILL STICK WITH AN SPS FOR NOW TO HIGHLIGHT THE
BRIEF/LIGHT FREEZING RAIN.
MAYES
&&
.PREV DISCUSSION... /ISSUED 532 AM CST THU NOV 21 2013/
AVIATION...12Z TAFS FOR KOFK...KLNK AND KOMA.
MVFR CIGS AND NORTH WINDS 20 TO 30KT CAN BE EXPECTED INTO THE
AFTERNOON WITH PRECIPITATION STAYING TO THE NORTH AND SOUTH OF TAF
SITES. IN THE 20Z TO 00Z TIMEFRAME...LIGHT SNOW WILL BEGIN TO
DEVELOP AND COULD BECOME MODERATE AT TIMES BETWEEN 00Z AND 06Z.
CIGS WILL FALL TO BELOW FL010 WITH VSBYS BETWEEN 1 AND 2 MILES AT
TIMES. ISOLATED VSBYS BELOW A MILE ARE CERTAINLY POSSIBLE...AND A
BRIEF MIX OF SLEET COULD OCCUR AT KLNK AND KOMA BEFORE 00Z. THE
SNOW SHOULD MOVE EAST OF TAF SITES BETWEEN 06Z AND 09Z WITH THE
NORTH WINDS DECREASING TO 15KT. CIGS WILL LIKELY LIFT TO VFR
BEFORE THE END OF THE TAF PERIOD.
DERGAN
PREV DISCUSSION... /ISSUED 423 AM CST THU NOV 21 2013/
DISCUSSION...
THE BULK OF THE WEATHER WILL BE IN THE FIRST 36HRS OF THE
FORECAST WITH THE MAIN FORECAST CONCERNS ONSET OF PRECIPITATION
AND PRECIPITATION TYPE AND SNOWFALL AMOUNTS.
LATEST SATELLITE AND RADAR TRENDS SHOW ENHANCED CLOUDS QUICKLY
LIFTING NORTHEAST THIS MORNING ACROSS KANSAS AND MISSOURI. THE
WSR-88D RADAR HAD A BAND OF RAIN FROM HAYS TO EMPORIA INTO
SOUTHEAST KANSAS...SHIFTING EAST AND LIFTING NORTHEAST. AT THE
SURFACE...ALL SITES HAD NORTH WINDS...WITH THE GUSTY WINDS TO A
NEBRASKA CITY RED OAK LINE. TEMPERATURES WERE IN THE LOWER 20S
NORTH TO 40 SOUTH.
COMPLEX PATTERN TODAY RESULTING FROM SPLIT FLOW REGIME. A SHORTWAVE
TROF ENERGY WITHIN THE LONGWAVE TROF PASSES TO OUR SOUTH THIS
MORNING. 40M HT FALLS WERE NOTED WITH THE CA H5 TROF AND A 100-140KT
JET EXTENDED FROM OFF THE CAL COAST INTO SOUTHERN ARIZONA. THE
FORECAST AREA IS UNDER THE INFLUENCE OF THESE WEATHER
SYSTEMS...HOWEVER THE FORCING IS WEAKER DUE TO THE LACK OF FOCUS.
THIS MORNING...AS THE H3 JET MOVES INTO KANSAS AND MISSOURI...UPPER
LEVEL DIVERGENCE IN THE LEFT EXIT REGION OVER THE AREA QUICKLY MOVES
INTO ILLINOIS BY 18Z. THE H5 LOW CLOSES OFF OVER SOUTHERN CALIFORNIA
THIS AFTERNOON...MEANWHILE...ENERGY FROM THE NORTHERN STREAM MOVES
THROUGH THE NORTHERN PLAINS WITH UPPER LEVEL DIVERGENCE FROM THE
RIGHT ENTRANCE REGION OF THE JET INCREASING OVER THE WESTERN PLAINS.
THERE IS SOME FRONTOGENESIS OVER CENTRAL NEBRASKA THIS
MORNING...THEN LIFTS BACK TO THE NORTHWEST BY MIDDAY...IS FAIRLY
WEAK IN NORTHEAST NEBRASKA THIS AFTERNOON THEN STRENGTHENS AND MOVES
THROUGH THE REST OF THE FORECAST AREA TONIGHT.
HAVE LOWERED POPS FOR MUCH OF THE FORECAST AREA THIS MORNING AS
THE BEST CHANCE FOR MEASURABLE PRECIPITATION LOOKS TO BE SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA. ALTHOUGH THE GFS/EC HAVE SOME TENTH
OF AN INCH PRECIP AMOUNTS IN THE SOUTHEAST NEBRASKA...HI
RESOLUTION HRRR/RAP/NAM ARE A BIT DRIER. THE NAM SEEMED TO HAVE
THE BEST HANDLE ON THE LOW LEVEL TEMPS AND DEWPOINTS. THE GFS/EC
WERE WAY TOO MOIST. FOR THIS PACKAGE LEANED TOWARD THE
NAM/HOPWRF/4KM WRF. HAVE HIGHER POPS SOUTH OF A BEATRICE TO RED
OAK LINE THIS MORNING WITH SLIGHT CHANCES FARTHER NORTH TOWARD
OMAHA. DUE TO THE COLD AIR...FORECAST SOUNDINGS AND TIMESECTIONS
SHOW A MIX OF PRECIP TYPES. WHERE THE PRECIPITATION IS EXPECTED
TO ACCUMULATE...IT SHOULD BE MAINLY RAIN...HOWEVER THERE COULD BE
A MIX FARTHER NORTH IN THE COLDER AIR. DID NOT ISSUE ANY HEADLINES
DUE TO LOW CONFIDENCE IN EXTENT OF ACCUMULATION OF ANY MIXED
PRECIPITATION. NORTHWEST WINDS AT 20 TO 30 MPH SUSTAINED WILL
CONTINUE AND TEMPERATURES WILL NOT GO ANYWHERE...HOLDING MAINLY IN
THE 20S NORTH AND 30S SOUTH.
THIS AFTERNOON...THE COLD AIR WILL BECOME DEEPER AND SNOW IS
EXPECTED TO DEVELOP OVER NORTHERN NEBRASKA WITH THE NORTHERN
STREAM TROF...WITH AREA OF PRECIPITATION OVER FAR SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA SHIFTING EASTWARD. LIGHT SNOW SHOULD
THEN OVERSPREAD THE AREA...MOVING OUT OF THE FORECAST AREA AFTER
06Z. DUE TO THE SHORTER DURATION OF PRECIPITATION HAVE LOWERED
AMOUNTS AND THEY NOW AVERAGE A TRACE TO 1.5 INCHES.
SURFACE HIGH PRESSURE WILL BUILD IN FRIDAY THEN A REINFORCING SHOT
OF COLD AIR SATURDAY. THE ARCTIC FRONT MOVES THROUGH SATURDAY WITH
THE BRUNT OF THE COLD AIR SLIDING TO OUR EAST OVER IOWA AND THE
GREAT LAKES AS THE MID LEVEL TROF DIG INTO THE EASTERN U.S. BY
SUNDAY...SOUTHWEST FLOW WILL RETURN AND TEMPERATURES WILL
RECOVER...BUT WILL REMAIN WELL BELOW NORMAL. THE STORM SYSTEM OVER
THE SOUTHWEST U.S. WILL SHIFT TOWARD THE FOUR CORNERS REGION AND
PRECIP CHANCES MAY BE NEEDED SUNDAY NIGHT INTO MONDAY. ANY
PRECIPITATION LOOKS TO BE LIGHT AND MAY NOT MEASURE. MONDAY ANOTHER
WEAK COLD FRONT MOVES THROUGH WITH A MID LEVEL TROF MOVING THROUGH
THE GREAT LAKES AND THE CLOSE LOW SLOWLY TRACKING ACROSS THE
SOUTHERN PLAINS. THERE ARE SOME AMPLITUDE DIFFERENCE IN THE H5
PATTERN BY WEDNESDAY. THE EC HAS A SHARPENING TROF OVER THE GREAT
LAKES WITH BACKDOOR COOLING...WHILE THE GFS IS FLATTER WITH WARMING
AHEAD OF A WEAK FRONT.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1225 PM EST THU NOV 21 2013
.SYNOPSIS...
A COASTAL TROUGH WILL BRING PERIODS OF ATLANTIC CLOUD COVER ONSHORE
THROUGH FRIDAY. A COLD FRONT WILL CROSS THE AREA LATE SATURDAY
FOLLOWED BY A BRIEF PERIOD OF VERY COLD AIR. A SIGNIFICANT RAIN
EVENT IS BECOMING MORE LIKELY TOWARD THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...EAST TO NORTHEAST LOW-LEVEL FLOW WILL
PROVIDE SOME ATLANTIC MOISTURE WHILE WESTERLY WINDS ALOFT SPREAD A
VARIETY OF MID AND HIGH CLOUDS INTO THE REGION. REGARDLESS...ENOUGH
BREAKS IN THE CLOUDS THIS MORNING TO ALLOW FOR A RAPID WARM-UP...
ESPECIALLY ACROSS COASTAL SOUTHEAST NC WHERE TEMPS ARE ALREADY IN
THE MID TO UPPER 50S. COOLER TEMPERATURES (LOWER 50S) PREVAIL ACROSS
REMAINING AREAS...AND THE MODELS CONTINUE TO VARY SIGNIFICANTLY WITH
MAX TEMPS THIS AFTERNOON. PLAN TO LOWER TEMPS WHERE THE CLOUD
COVER IS EXPECTED TO HAVE THE MOST IMPACT WHILE NUDGING THEM UPWARDS
WHERE THE BIGGEST BREAKS ARE ANTICIPATED. OVERALL...A TRICKY TEMP
FORECAST TODAY GIVEN THE RESIDUAL WEDGE...VARYING CLOUD COVER... AND
LOWER MID-LATE NOVEMBER SUN ANGLE. WIDELY SCATTERED SHOWER ACTIVITY
ASSOCIATED WITH THE WEAK TROUGH WILL PRIMARILY REMAIN OVER THE WATER
THROUGH MUCH OF THE DAY...THOUGH A COUPLE OF THEM MAY MAKE IT TO THE
COAST LATER IN THE DAY.
PREVIOUS DISCUSSION...
DRY RIDGING AT 700 AND 500 MILLIBARS USUALLY IMPLIES BENIGN WEATHER
DOWN HERE AT THE SURFACE. NOT SO THIS TIME AS A TIGHT PRESSURE
GRADIENT AROUND THE SOUTHERN PERIPHERY OF 1038 MB HIGH PRESSURE OVER
NEW ENGLAND...PLUS A WEAK COASTAL TROUGH OUT NEAR THE GULF STREAM
ARE ADVECTING ATLANTIC MOISTURE ONSHORE. THIS MOISTURE EXTENDS
VERTICALLY TO AROUND 8000 FEET AT WHICH POINT A SIGNIFICANT LAYER OF
DRY AIR EXISTS WITHIN THE WESTERLY FLOW ALOFT.
AS WAS TRUE ON THE 00Z MODEL RUNS...THERE ARE STILL UNANSWERED BASIC
QUESTIONS CONCERNING TODAY`S FORECAST USING THE 06Z RUNS. THE AMOUNT
OF LOW CLOUD COVER THAT REMAINS INTO THE AFTERNOON WILL LARGELY
DETERMINE OUR TEMPERATURES. ANY ISENTROPIC LIFT IS SITUATED VERY LOW
IN THE ATMOSPHERE AND BECOMES QUITE WEAK BY AFTERNOON. THERE IS
NEARLY A TEN-DEGREE DIFFERENCE BETWEEN THE 00Z NAM AND GFS INLAND...
AND NO CLEAR SIGNAL WHICH MODEL...IF EITHER...IS RIGHT. THE WEDGE
PATTERN TO THE PRESSURE AND WIND FIELDS ACROSS THE CAROLINAS IMPLIES
THE COOLER GFS MAY BE THE WAY TO GO...ALTHOUGH I WOULD FEEL MORE
CONFIDENT IN THIS DECISION IF THERE WERE RAIN AND/OR WIDESPREAD LOW
STRATUS ACROSS CENTRAL NORTH CAROLINA TO HELP OFFSET INSOLATION. THE
06Z RUNS ESSENTIALLY MIRRORED THEIR 00Z COUNTERPARTS...BUT THE
LATEST RUC AND HRRR HAVE COME FIRMLY INTO LINE WITH THE WARMER 00Z
AND 06Z NAM.
THE AIRMASS IS MODIFYING QUICKLY OVERHEAD WITH WARM ADVECTION IN THE
800-950 MB LAYER ADDING A GOOD 2-3 DEGREES C THROUGH THIS EVENING.
ALONG THIS COAST THIS SHOULD YIELD HIGHS IN THE UPPER 60S...PERHAPS
EVEN SQUEAKING OUT A 70 DEGREE READING HERE AND THERE AWAY FROM THE
BEACHES. FARTHER INLAND IS WHERE LARGER QUESTIONS REMAIN. WITH LOW
CONFIDENCE I AM FORECASTING HIGHS IN THE 62-64 RANGE ALONG THE I-95
CORRIDOR...60-61 FOR BENNETTSVILLE AND DARLINGTON...AND 64-67 FROM
ELIZABETHTOWN AND WHITEVILLE THROUGH MARION...LAKE CITY AND
KINGSTREE.
ALTHOUGH RADAR SHOWS A BAND OF SHOWERS ALONG THE WESTERN EDGE OF THE
GULF STREAM...PROBABILITIES OF MEASURABLE RAIN ARE LOW TODAY GIVEN
POOR ISENTROPIC LIFT SHOWN ON ANY MODEL. LINEAR EXTRAPOLATION OF THE
SHOWERS SHOULD HAVE ALREADY PUSHED THEM ONSHORE HOURS AGO...
INDICATING LOCAL ENVIRONMENTAL CONDITIONS OUT AT THE EDGE OF THE
GULF STREAM ARE PROBABLY KEY TO SUSTAINING THIS ACTIVITY. I AM
INCLUDING A 20 POP NEAR THE COAST LATER TODAY JUST IN CASE SOMETHING
SNEAKS IN OFF THE WATER DURING THE BEST WARM ADVECTION AROUND NOON.
WIND FIELDS SHOULD WEAKEN TONIGHT AS THE HIGH OVER NEW ENGLAND
RAPIDLY WEAKENS AND SHIFTS OFFSHORE. PLENTY OF LOW LEVEL ATLANTIC
MOISTURE WILL MODERATE TEMPERATURES...AND LOWS SHOULD RANGE FROM
AROUND 50 IN LUMBERTON TO THE MID 50S AT THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE FORECAST CHALLENGE CONTINUES TO THE BE
THE WEAK FORCING AND MOISTURE ASSOCIATED WITH A COASTAL TROUGH
FRIDAY THEN THE MOISTURE WITH A LONG ADVERTISED FRONT MOVING ACROSS
LATE SATURDAY/EARLY SUNDAY. THE GUIDANCE HAS WALKED BACK MOISTURE
WITH THE COASTAL TROUGH FRIDAY AND WITH THE ERRATIC NATURE OF THESE
TYPE OF FEATURES AND VOLATILITY OF GUIDANCE...THE BEST OPTION IS TO
KEEP POPS AS THEY ARE. FOR SATURDAY I HAVE FINE TUNED POPS TO
EMPHASIZE THE AFTERNOON AND EVENING HOURS PER THE LATEST MODEL
GUIDANCE. AS FOR TEMPERATURES...THE MET NUMBERS ARE WARMER ACROSS
THE BOARD AND GENERALLY LEANED TOWARD THESE NUMBERS THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM WEDNESDAY...THE EXTENDED FORECAST LOOKS TO BE VERY
ACTIVE WITH THE EMPHASIS NOW SHIFTING TO THE END OF THE PERIOD WHEN
A CUTOFF LOW OUT WEST OPENS UP AND MOVES ACROSS THE SOUTHEAST.
SUNDAY AND MONDAY ARE FAIRLY CLEAR CUT AS COLD AIR ADVECTION
DOMINATES WITH TEMPERATURES MOST LIKELY NOT GETTING OUT OF THE 40S
SUNDAY AND DEPENDING ON DECOUPLING...MONDAY MORNINGS LOWS WELL INTO
THE 20S. FOR TUESDAY AND WEDNESDAY...THE LOW TAKES SHAPE IN THE GULF
OF MEXICO WITH A RELATIVELY WEAK AND FLEETING COLD AIR WEDGE HANGING
ON. ISENTROPIC LIFT DEVELOPS IN EARNEST LATE TUESDAY. THE LOW
ATTEMPTS TO REDEVELOP ALONG THE COASTAL FRONT WEDNESDAY BUT AT LEAST
AT THIS POINT DOESN/T BECOME DOMINANT. TOUGH CALL ON MILLER A OR B
SCENARIO HOWEVER THIS FAR OUT THIS IS HAGGLING OVER DETAILS AND RAIN
WILL CONTINUE WEDNESDAY AS THE MID LEVEL SYSTEM MOVES ACROSS. WE
HAVE FAIRLY HIGH POPS FOR TUESDAY AND ESPECIALLY WEDNESDAY ALREADY
SO I ONLY INCREMENTALLY INCREASED POPS. NO CHANGES TO TEMPERATURE
FORECAST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...CURRENT VISIBLE SATELLITE IMAGERY SHOWS PATCHES OF
ALTOCUMULUS 8-10KFT MAINLY OVER KFLO AND OUR INLAND COUNTIES. THERE
ARE ALSO SOME SCT 2-3KFT CLOUDS LINGERING ALONG THE COAST. VFR
SHOULD PREVAIL THIS AFTN WITH NORTHEAST WINDS AOB 10 KTS...THOUGH WE
COULD SEE SOME TEMPO MVFR CIGS ALONG THE COAST. LIGHT WINDS TONIGHT
WITHIN A VERY MOIST LOW LEVEL ENVIRONMENT SHOULD SUPPORT FOG AFTER
06Z FRIDAY. HOWEVER...MODEL SOUNDINGS AND GUIDANCE SUGGEST MID LEVEL
CIGS WILL PREVAIL TONIGHT...WHICH WOULD PREVENT OPTIMAL RADIATIONAL
COOLING. THEREFORE...WILL ONLY INCLUDE MVFR FOG FOR ALL SITES...
BEGINNING WITH KLBT AND KFLO BY 06Z. THESE INLAND SITES HAVE THE
BEST CHANCES FOR FOG...BUT WIDESPREAD IFR SEEMS UNLIKELY WITH THE
EXPECTED CLOUD COVER. EXPECT VFR DURING THE DAY ON FRIDAY WITH S-SE
WINDS AROUND 5 KTS.
EXTENDED OUTLOOK...CHANCE OF SHOWERS/MVFR CIGS ON SATURDAY WITH A
COLD FRONT. VFR SUNDAY AND MONDAY. EXPECT GUSTY NORTH WINDS ON
SUNDAY BEHIND THE FRONT. INCREASING CHANCE FOR SHOWERS ON TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 920 AM THURSDAY...BASED ON THE MARINE OBSERVATIONS IT IS
IMPLIED THAT SMALL CRAFT CONDITIONS LIKELY CONTINUE ACROSS THE OUTER
COASTAL WATERS...EXCEPT FROM MURRELLS INLET TO LITTLE RIVER INLET.
CONDITIONS WILL SLOWLY IMPROVE AS THE WEAKENING COASTAL TROUGH
SHIFTS FARTHER WEST. MAY NEED TO REFINE THE ENDING TIME OF THE
REMAINING SMALL CRAFT AREAS BASED ON TRENDS HEADING INTO THIS
AFTERNOON...BUT UNTIL THEN CHOPPY SEAS WILL CONTINUE WITH THE
NORTHEAST TO EAST FETCH THAT HAS BEEN IN PLACE. WIDELY SCATTERED
SHOWERS WILL PRIMARILY AFFECT THE OUTER COASTAL WATERS THROUGH MOST
OF THE DAY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...THE PROLONGED NORTHEAST FLOW WILL BE ABATING
AT THE BEGINNING OF THE PERIOD AS SURFACE HIGH PRESSURE WEAKENS AND
ELONGATES WEST TO EAST. A WEAK SOUTH TO SOUTHWEST TO EVENTUALLY
WESTERLY FLOW WILL THEN TAKE PLACE. SPEEDS WILL REMAIN TEPID AROUND
TEN KNOTS. SATURDAY EVENING THE FRONT WILL CROSS THE WATERS AND BY
0600 UTC SUNDAY ELEMENTS WILL BE VERY DIFFERENT FROM JUST A FEW
HOURS EARLIER AS NORTH WINDS OF 25-30 KNOTS DEVELOP. A BRIEF GALE
WARNING CANNOT BE RULED OUT. SEAS OF COURSE WILL BE BENIGN FOR MOST
OF THE PERIOD BUT RAMPING UP QUICKLY ESPECIALLY ACROSS THE OUTER
WATERS LATE WITH THE RAPID INCREASE IN WIND SPEEDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...POTENT COLD AIR ADVECTION WILL DOMINATE THE
COASTAL WATERS SUNDAY WITH NORTH WINDS OF 20-25 KNOTS. WITH THE
PROGRESSIVE PATTERN...THE SURFACE HIGH WILL QUICKLY MOVE ACROSS THE
WATERS MONDAY WITH NORTHEAST WINDS DOWN TO 10-15 KNOTS AND EVEN LESS
BY THE END OF THE DAY. SEAS WILL BE HIGH SUNDAY BUT CONFINED TO THE
OUTER WATERS CONSIDERING THE FETCH WITH A SMALL CRAFT ADVISORY
LIKELY CONTINUING. MONDAY SEAS DROP TO 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS NORMAN OK
1216 PM CST THU NOV 21 2013
.AVIATION...
STRONG COLD FRONT IS MOVING THROUGH THE AREA. BRISK NORTH WINDS
AND MVFR CONDITIONS WILL OCCUR BEHIND THE FRONT. PRECIPITATION IS
CHANCES ARE SOMEWHAT UNCERTAIN AS MODELS HAVE VERY DIFFERENT
SOLUTIONS WITH RESPECT TO PRECIPITATION DEVELOPMENT... ESPECIALLY
NORTHWEST. BUT PRECIPITATION THAT OCCURS WILL MAINLY BE IN THE
FORM OF RAIN WHERE SURFACE TEMPERATURES ARE ABOVE FREEZING... AND
FREEZING RAIN WHERE TEMPERATURES ARE BELOW FREEZING. THERE WILL
ALSO BE SOME SLEET POSSIBLE AT KGAG AND KWWR LATE IN THE FORECAST
PERIOD.
&&
.PREV DISCUSSION... /ISSUED 956 AM CST THU NOV 21 2013/
UPDATE...
COLD FRONT IS MOVING QUICKLY AND IS WELL AHEAD OF SCHEDULE. NONE
OF THE SYNOPTIC SCALE MODELS HAVE DONE WELL WITH THIS TIMING AND
THE TIMING IS EVEN QUICKER THAN THE ACCELERATED TIMING THAT THE
MIDNIGHT SHIFT WORKED IN. HAVE UPDATED THE FORECAST WITH AN EVEN
FASTER ARRIVAL OF THE COLD FRONT CLOSER TO WHAT THE RAP IS
FORECASTING.
PREV DISCUSSION... /ISSUED 625 AM CST THU NOV 21 2013/
DISCUSSION...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
HIGH CONFIDENCE IN MVFR TO IFR CONDITIONS THROUGH THE ENTIRE
FORECAST PERIOD. AN AREA OF SHRA/TSRA WILL CONTINUE TO MOVE ACROSS
NORTHERN OK NEAR PNC THROUGH LATE THIS MORNING. A STRONG COLD
FRONT WILL THEN MOVE INTO WWR/GAG AROUND 14-15Z RESULTING IN A
WIND SHIFT FROM THE NORTH. SUSTAINED WINDS AROUND 25 TO 30 KT...LOW
CIGS...AND EVENTUALLY FZRA/DZ WILL ACCOMPANY THIS ARCTIC FRONT
THROUGH 12Z TOMORROW.
PREV DISCUSSION... /ISSUED 529 AM CST THU NOV 21 2013/
DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE ACROSS PORTIONS OF NORTHERN OK
EARLY THIS MORNING WITHIN ZONE OF ISENTROPIC ASCENT AHEAD OF A MID
LEVEL SHORTWAVE TROUGH. EXPECT MOST OF THIS ACTIVITY TO SHIFT OUT
OF OUR FA AROUND 15-18Z. AROUND 430 AM...THE HIGHLY ANTICIPATED
COLD FRONT WAS MOVING INTO SW KS. THIS IS A BIT FASTER THAN MOST
OF THE MODELS SUGGESTED YESTERDAY...WHICH OFTEN OCCURS WITH ARCTIC
AIRMASSES. DECIDED TO SPEED UP THE FRONT CLOSER TO THE FASTEST
SOLUTIONS...THE CANADIAN AND HRRR. EXPECT THE FRONT FROM NEAR PNC
TO KINGFISHER AND ELK CITY AROUND NOON. TEMPS WILL HAVE A CHANCE
TO CLIMB AHEAD OF IT WITHIN SW 850 FLOW ACROSS CENTRAL/SW OK AND
WESTERN NORTH TEXAS FROM THE MID 60S TO UPPER 70S
RESPECTIVELY...BUT WILL QUICKLY DROP BEHIND IT. STILL EXPECT
ENOUGH INSTABILITY AHEAD OF THE FRONT OVER WESTERN NORTH TEXAS AND
SOUTHERN OK FOR SOME STRONGER STORMS TO DEVELOP LATE THIS
AFTERNOON AND EARLY THIS EVENING. THE PRESSURE GRADIENT WITH THE
FRONT WILL ALSO SUPPORT HIGH ENOUGH WINDS FOR AN ADVISORY THROUGH
LATE TONIGHT. THE MAIN CONCERN...HOWEVER...WILL BE POST-FRONTAL
FREEZING RAIN AND DRIZZLE EARLY TOMORROW MORNING.
CONFIDENCE IS HIGH ENOUGH THAT AT LEAST SOME ICING WILL OCCUR ON
ELEVATED SURFACES AS PERSISTENT LIGHT FREEZING RAIN/DRIZZLE
DEVELOPS BEHIND THE FRONT WITH ENOUGH LOW TO MID LEVEL MOISTURE
PRESENT....AND SOME SUBTLE ISENTROPIC ASCENT NEAR SC/S/SW OK. THE
NAM12 IS STILL THE MOST AGGRESSIVE SOLUTION WITH REGARDS TO
QPF...KEEPING SOUTHERLY TO EASTERLY FLOW PRESENT ON THE 290-300K
SURFACES THROUGH FRIDAY MORNING AND THUS MORE SIGNFICANT
ISENTROPIC ASCENT. IT CONTINUES TO BE THE OUTLIER THOUGH AND AM
NOT VERY CONFIDENT IN IT VERIFYING. ALSO HAVE INCLUDED SNOW AND
SLEET FOR W/N/NW OK. THIS IS WHERE A WEAK MID LEVEL SHORTWAVE
TROUGH WILL ROUND A SHORTWAVE RIDGE THROUGH LATE FRIDAY
MORNING...ENOUGH MOISTURE WILL BE PRESENT THROUGH THE DENDRITIC
ZONE...AND DIV ALOFT WILL ASSIST IN LIFT. EXPECT MAYBE AN INCH
ACROSS THE NW ZONES FRIDAY. FREEZING DRIZZLE MAY LINGER MAINLY
ALONG AND SOUTH OF I40 THROUGH LATE FRI NIGHT...BUT DO NOT EXPECT
MUCH ICE ACCUMULATION WITH THIS AS MUCH DRIER LOW-MID LEVEL AIR
QUICKLY DIVES SOUTH.
THE NEXT CHALLENGE IN THE FORECAST WILL BE THE PROGRESSION OF A
CLOSED LOW MOVING OVER THE SW CONUS SUN. SOLUTIONS SUGGEST AT
LEAST A NORTHERN BRANCH OF THE LOW MOVING CLOSER TO OUR NECK OF
THE WOODS WITH THIS SYSTEM. CONFIDENCE IS INCREASING THAT
SNOW/SLEET AND RAIN WILL ACCOMPANY THIS FEATURE SUNDAY THROUGH AT
LEAST MONDAY. WILL CONTINUE TO INCREASE POPS AND MENTION
SNOW...ALTHOUGH AMOUNTS ARE STILL UNCLEAR.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 65 29 34 29 / 40 70 50 30
HOBART OK 70 27 32 27 / 30 30 40 20
WICHITA FALLS TX 76 32 34 30 / 80 60 60 40
GAGE OK 55 23 27 24 / 20 60 30 20
PONCA CITY OK 57 28 34 29 / 70 40 40 20
DURANT OK 67 41 41 36 / 50 80 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR OKZ004>030-033>038.
WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
OKZ014>017-021>025-027>029-033>038-044.
TX...WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST FRIDAY FOR
TXZ083>086.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1156 AM CST THU NOV 21 2013
.UPDATE...
UPDATED FOR AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1032 AM CST THU NOV 21 2013/
UPDATE...MORNING UPDATE.
CURRENTLY...A COLD FRONT EXTENDS FROM NORTHWEST MISSOURI...THROUGH
EASTERN KANSAS...AND PARALLEL TO THE OKLAHOMA PANHANDLE. MOST
HEAVY RAIN IS OCCURRING OUT AHEAD OF THE FRONT...WHERE WAA OVERRUNNING
IS OCCURRING IN SOUTHERN MISSOURI AND EASTERN KANSAS. TEMPERATURES
BEHIND THE FRONT ARE IN THE 30S...WITH 50S OUT AHEAD OF THE FRONT.
TEMPERATURES ACROSS THE MID-SOUTH ARE HOLDING STEADY IN THE UPPER
50S AND SLOWLY WARMING UNDER PARTLY SUNNY SKIES AND MODERATE WAA.
TEMPERATURES TODAY MAY LEVEL OUT SOONER RATHER THAN LATER...DUE TO
THE ABUNDANT CLOUD COVER LOCATED JUST TO THE WEST OF THE
MISSISSIPPI RIVER. WINDS ARE BEGINNING TO GUST A BIT...PREDOMINANTLY
NEAR THE MISSISSIPPI RIVER...WITH GUSTS TO 20 MPH OUT OF THE SSE.
RAIN SHOWERS ARE CURRENTLY HOLDING BACK IN CENTRAL ARKANSAS...BUT
ARE EXPECTED TO MOVE INTO THE MEMPHIS METRO AREA AROUND 5PM WITH
WIDESPREAD SHOWERS DEVELOPING LATER THIS EVENING.
FORECAST IS ON TRACK AND NO IMMEDIATE CHANGES ARE NEEDED.
AC3
PREV DISCUSSION... /ISSUED 525 AM CST THU NOV 21 2013/
DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
18Z TAFS
MOIST GULF AIR WAS FLOWING INTO THE MIDSOUTH A LITTLE AHEAD OF
SCHEDULE 1730Z. WIDESPREAD SHOWERS WERE NOTED ON RADAR AROUND
JBR AND SHOULD BE INTO MEM TOWARD 20Z. MVFR CIGS HAD STREAMED
NORTH THROUGH THE DELTA INTO MEM...AND EXPECT THE CLEAR SPOT
BETWEEN TUP AND MKL TO CLOSE DOWN BY MID AFTERNOON. JBR AND MEM
WILL LIKELY SEE CIGS DROP BELOW THE FL020 FUEL ALTERNATE THIS
AFTERNOON. AMD FOR BOTH SITES HAVE BEEN SENT ACCORDINGLY.
PREFRONTAL IFR CIGS APPEAR A GOOD BET BY LATE EVENING...PERSISTING
THROUGH THE OVERNIGHT...AHEAD OF THE APPROACHING COLD FRONT.
VSBY SHOULD IMPROVE WITH THE ARRIVAL OF THE ARCTIC AIR 11Z TO 14Z...
BUT POST FRONTAL IFR CIGS WILL LIKELY BE QUITE STUBBORN TO IMPROVE
TO MVFR BY 22/18Z.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1032 AM CST THU NOV 21 2013
.UPDATE...MORNING UPDATE.
CURRENTLY...A COLD FRONT EXTENDS FROM NORTHWEST MISSOURI...THROUGH
EASTERN KANSAS...AND PARALLEL TO THE OKLAHOMA PANHANDLE. MOST
HEAVY RAIN IS OCCURRING OUT AHEAD OF THE FRONT...WHERE WAA OVERRUNNING
IS OCCURRING IN SOUTHERN MISSOURI AND EASTERN KANSAS. TEMPERATURES
BEHIND THE FRONT ARE IN THE 30S...WITH 50S OUT AHEAD OF THE FRONT.
TEMPERATURES ACROSS THE MID-SOUTH ARE HOLDING STEADY IN THE UPPER
50S AND SLOWLY WARMING UNDER PARTLY SUNNY SKIES AND MODERATE WAA.
TEMPERATURES TODAY MAY LEVEL OUT SOONER RATHER THAN LATER...DUE TO
THE ABUNDANT CLOUD COVER LOCATED JUST TO THE WEST OF THE
MISSISSIPPI RIVER. WINDS ARE BEGINNING TO GUST A BIT...PREDOMINANTLY
NEAR THE MISSISSIPPI RIVER...WITH GUSTS TO 20 MPH OUT OF THE SSE.
RAIN SHOWERS ARE CURRENTLY HOLDING BACK IN CENTRAL ARKANSAS...BUT
ARE EXPECTED TO MOVE INTO THE MEMPHIS METRO AREA AROUND 5PM WITH
WIDESPREAD SHOWERS DEVELOPING LATER THIS EVENING.
FORECAST IS ON TRACK AND NO IMMEDIATE CHANGES ARE NEEDED.
AC3
&&
.PREV DISCUSSION... /ISSUED 525 AM CST THU NOV 21 2013/
&&
.DISCUSSION...
A DEVELOPING LOW PRESSURE SYSTEM NEAR THE OKLAHOMA PANHANDLE IS
ALREADY BEGINNING TO SPREAD RAIN INTO NORTH CENTRAL ARKANSAS.
EXPECT THIS BAND TO CONTINUE PUSHING EAST THIS MORNING AND WILL
PUSH INTO NORTHEAST ARKANSAS BY LATER THIS MORNING. IN
ADDITION...LATEST HRRR CONTINUES TO SHOW SPOTTY WAA SHOWERS
DEVELOPING THIS MORNING INTO THIS AFTERNOON OVER A GOOD PORTION OF
THE CWA. AS A RESULT...HAVE EITHER BUMPED UP POPS OR ADDED POPS TO
MUCH OF THE CWA. THE ONLY LOCATIONS THAT MAY STAY DRY WILL BE LONG
THE TENNESSEE RIVER IN WEST TENNESSEE AND NORTHEAST MISSISSIPPI.
IN ADDITION...STRATUS CONTINUES TO STREAM TOWARD NORTHEAST
MISSISSIPPI FROM THE SOUTHEAST WHILE ABUNDANT MID TO HIGH CLOUDS
STREAM IN FROM THE WEST. THUS EXPECT BY THIS AFTERNOON THE ENTIRE
CWA WILL BE MOSTLY CLOUDY. THE CLOUDS AND SHOWERS MAY HINDER
TEMPERATURES FROM WARMING AS MUCH AS PREVIOUSLY THOUGHT BUT SINCE
THERE IS DECENT WAA OCCURRING TODAY HAVE LEFT HIGHS RANGING FROM
THE LOWER 60S TO UPPER 60S FOR NOW.
BY TONIGHT...EXPECT RAIN TO BE FALLING ACROSS AT LEAST THE
EASTERN ARKANSAS...THE MISSOURI BOOTHEEL...MUCH OF WEST TENNESSEE
AND NORTHWEST MISSISSIPPI. THE ASSOCIATED COLD FRONT WILL BEGIN TO
PUSH INTO THE AREA AFTER MIDNIGHT. CAN/T RULE OUT A FEW EMBEDDED
THUNDERSTORMS OCCURRING AHEAD OF THE FRONT. THE FRONT WILL
CONTINUE TO PUSH THROUGH THE MIDSOUTH ON FRIDAY INTO FRIDAY NIGHT
NUMEROUS TO WIDESPREAD SHOWERS WILL OCCUR ON FRIDAY AND FRIDAY
NIGHT ACROSS THE ENTIRE MIDSOUTH. COLDER AIR WILL USHER INTO THE
MIDSOUTH BEHIND THE FRONT. EXPECT HIGHS ON SATURDAY TO OCCUR IN
THE MORNING WITH NEAR STEADY TEMPERATURES OR SLIGHTLY FALLING
TEMPERATURES IN THE AFTERNOON. SOME LINGERING RAIN MAY OCCUR
ACROSS NORTH MISSISSIPPI SATURDAY MORNING OTHERWISE CONDITIONS
WILL BE DRY. EXPECT THE HIGHS ON SATURDAY MORNING TO BE IN THE THE
LOWER 40S TO LOWER 50S WITH TEMPERATURES DROPPING INTO UPPER 30S
TO UPPER 40S IN THE AFTERNOON.
HIGH PRESSURE WILL BRIEFLY BUILD INTO THE MIDSOUTH ON SUNDAY BUT BY
SUNDAY NIGHT CLOUDS WILL BEGIN INCREASING AHEAD OF A DEVELOPING
LOW PRESSURE SYSTEM ALONG THE GULF COAST WHICH WOULD IMPACT THE
MIDSOUTH MONDAY THROUGH TUESDAY EVENING. WITH COLD AIR IN
PLACE...THIS IS A SYSTEM THAT BEARS WATCHING. PRECIPITATION WILL BEGIN TO
SPREAD INTO THE MIDSOUTH SUNDAY EVENING. EXPECT LOWS TO ACTUALLY OCCUR
IN THE EVENING. TEMPERATURES WILL LIKELY HOLD STEADY OR SLIGHTLY
RISE AFTER MIDNIGHT AS CLOUDS AHEAD OF THE SYSTEM SPREAD INTO THE
AREA. THE BIG QUESTION WILL BE WHAT THE TEMPERATURE IS AT A GIVEN
LOCATION WHEN THE PRECIPITATION STARTS. EXPECT MOST LOCATIONS TO
BE NEAR OR SLIGHTLY ABOVE FREEZING THUS PRECIPITATION WILL LIKELY
BE RAIN. HOWEVER WOULD NOT BE SURPRISED TO SEE AN INITIAL PERIOD
OF SLEET OCCUR DUE TO THE AMOUNT OF DRY AIR IN THE LOW LEVELS TO
OVERCOME BEFORE RAIN REACHES THE SURFACE. THE POSSIBLE EXCEPTION
MAY BE EXTREME NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL...AND
EXTREME NORTHWEST TENNESSEE WHERE TEMPERATURES MAY BE SLIGHTLY
BELOW FREEZING THUS ALLOWING PRECIPITATION WOULD FALL AS SNOW BUT
AGAIN COULD INITIALLY BEGIN AS SLEET. EVEN IF THIS WOULD OCCUR THE
GROUND IS TOO WARM FOR ANY ACCUMULATION TO OCCUR. ANY SNOW THAT
WOULD BE OCCURRING MONDAY MORNING WOULD QUICKLY CHANGEOVER TO RAIN
AS TEMPERATURES RISE ABOVE FREEZING.
AS THE SFC LOW TRACKS EASTWARD ALONG THE GULF COAST...COLDER AIR
WILL BEGIN TO WRAP AROUND THE BACK SIDE OF THE LOW ON TUESDAY INTO
TUESDAY NIGHT. BOTH THE 00Z ECMWF AND THE 00Z GFS SHOW THAT
TEMPERATURES WILL BE FALLING ON TUESDAY. ONE THING THAT BEARS
WATCHING IS HOW LOW THE TEMPERATURES DROP TUESDAY AFTERNOON INTO
TUESDAY NIGHT AS THE POTENT UPPER LOW SWINGS INTO THE AREA BEHIND
THE DEPARTING SFC LOW. THE 00Z ECMWF IS COLDER THAN THE 00Z GFS
WHICH IF ECMWF SOLUTION WERE TO END UP BEING
CORRECT...PRECIPITATION COULD CHANGEOVER TO SNOW TUESDAY NIGHT.
HOWEVER A LOT OF TIMES...THE PRECIPITATION CUTS OFF BEFORE THE
REALLY COLD AIR GETS INTO THE AREA SO WILL JUST HAVE TO WAIT AND
SEE. COLD HIGH PRESSURE WILL BUILD INTO THE MIDSOUTH ON WEDNESDAY. THE
ONLY SURE BET FROM THE WEEKEND TIME PERIOD THROUGH THE END OF THE
FORECAST PERIOD IS THAT TEMPERATURES WILL BE WAY BELOW NORMAL.
HIGHS WILL RANGE FROM THE MID 30S TO THE UPPER 40S.
KRM
&&
.AVIATION...
12Z TAF CYCLE
STRATUS SEEMS TO STILL HAVING TROUBLE MAKING IT TO TUP...BUT STILL
FEEL LIKE IT WILL MAKE IN BY SUNRISE. OTHERWISE VFR AT THE OTHER
SITES THROUGH MOST OF THE DAY.
LIGHT SHOWERS WILL BEGIN TO APPROACH JBR DURING THE MID
AFTERNOON...MEM SLIGHTLY BEFORE SUNSET...MKL JUST AFTER
SUNSET...AND TUP BY MIDNIGHT...STEADY RAIN WILL FOLLOW BY 3-4
HOURS. CIGS WILL LOWER TO MVFR LEVELS AS THE STEADIER RAIN
BEGINS...AND LIKELY TO IFR LEVELS BY MIDNIGHT AT ALL SITES.
WINDS SOUTHEAST 5 TO 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 57 60 42 / 30 70 100 70
MKL 66 54 59 41 / 20 50 100 60
JBR 62 52 54 37 / 40 100 90 40
TUP 68 55 65 47 / 10 20 70 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
348 PM CST THU NOV 21 2013
.DISCUSSION...
THERE HAS BEEN PRETTY GOOD SHOWER COVERAGE TODAY ACROSS MAINLY THE WESTERN
PORTIONS OF THE AREA...WITH A COUPLE 1 TO 2 INCH RAINFALL ESTIMATED
AMOUNTS EMBEDDED IN THE ACTIVITY. THE HRRR HAS DONE A DECENT JOB ON
TODAY`S COVERAGE...AND IF IT HOLDS TRUE EXPECT TO SEE LESS COVERAGE
LATER THIS AFTERNOON AND THIS EVENING. THE STRONG COLD FRONT WITH ASSOCIATED
SHOWERS AND THUNDERSTORMS IS STILL ON SCHEDULE TO MOVE INTO OUR NORTHERN
COUNTIES CLOSE TO SUNRISE TOMORROW...THEN MOVE THROUGH THE REST OF THE
AREA DURING THE MORNING AND AFTERNOON HOURS. BREEZY NORTH WINDS AND
A SHARP TEMPERATURE DROP WILL FOLLOW THE FRONTAL PASSAGE...AND HIGHS
FOR THE DAY WILL LIKELY OCCUR IN THE EARLY MORNING HOURS UP NORTH AND
IN THE LATE MORNING OR EARLY AFTERNOON HOURS NEAR THE COAST. COLDER
TEMPERATURES AND LINGERING RAIN/SHOWER CHANCES ARE THEN SET TO PERSIST
THROUGH MUCH OF THE WEEKEND. INCREASING RAIN CHANCES ARE THEN EXPECTED
BEGINNING LATE SUNDAY AND ON INTO TUESDAY MORNING AS THE NEXT STORM
SYSTEM DEVELOPS AND MOVES ACROSS THE AREA. MODELS CONTINUE TO DIFFER
ON THE TIMING AND LOCATION OF THIS SYSTEM`S WESTERN GULF OF MEXICO SURFACE
LOW. IF THIS SYSTEM STAYS CLOSER TO THE COAST PER ECMWF...THERE COULD
BE A BRIEF WINDOW OF STRONG/SEVERE STORMS NEAR THE COAST ON MONDAY MORNING.
IF THE LOW IS FURTHER OFFSHORE PER GFS...MUCH OF THE AREA WILL JUST
SEE COLD RAIN. OVERALL...HAVE LOWERED ALL TEMPERATURES A COUPLE OF DEGREES
OVER THE WEEKEND AND INTO THE START OF NEXT WEEK. IF THIS TREND PERSISTS
AND LOTS OF PARAMETERS COME TOGETHER AND FALL INTO PLACE...WE MIGHT
NEED TO TAKE A CLOSER LOOK AT THE POSSIBILITY OF SOME FROZEN PRECIPITATION
CHANCES SUNDAY NIGHT THROUGH MONDAY MORNING ACROSS PORTIONS OF OUR FAR
NORTHERN COUNTIES. AT THIS TIME...FROZEN STUFF HAS MUCH BETTER CHANCES
OF OCCURRING WELL OFF TO OUR NORTHWEST AND WEST. EVERYTHING IS STILL
ON SCHEDULE TO CLEAR ON OUT OF THE AREA ON TUESDAY RESULTING IN MUCH
QUIETER WEATHER AS WE HEAD TOWARD THE THANKSGIVING HOLIDAY. AFTER
TOMORROW...THANKSGIVING DAY WILL PROBABLY BE THE FIRST DAY THE AREA
HAS HIGH TEMPERATURES COME BACK ABOVE 60 DEGREES.
42
&&
.MARINE...
MODERATE ONSHORE WINDS WILL CONTINUE THROUGH TONIGHT AS THE NEXT
COLD FRONT APPROACHES THE AREA. THERE IS AGAIN A CHANCE OF SEA FOG
TOMORROW MORNING. IT WILL BE A CHALLENGE THOUGH GIVEN HOW WATER
TEMPERATURES HAVE WARMED A BIT. DEWPOINTS ARE IN THE MID 70S
THOUGH. IF WINDS DUE BACK MORE EASTERLY NEAR THE COAST AS ECMWF
AND NAM HINT WOULD BE A MORE FAVORABLE SET UP FOR SEA FOG
DEVELOPMENT. RAP AND TEXAS TECH WRF ARE FASTEST WITH THE FRONT
HAVING IT ON PACE TO REACH THE COAST BY MID AFTERNOON. BEHIND THE
FRONT WINDS WILL BE ON THE INCREASE. WINDS WILL REACH ADVISORY
CRITERIA LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING. WINDS
SHOULD PEAK IN THE 20 TO 30KT RANGE SATURDAY AFTERNOON WITH GUSTS
APPROACHING GALE FORCE. SEAS IN OFFSHORE AREAS WILL BUILD TO
AROUND 9 TO 12 FEET. STRONG NORTHERLY WINDS WILL BEGIN TO TURN
NORTHEASTERLY SUNDAY BUT REMAIN STRONG.
MODELS CONTINUE TO ADVERTISE A COASTAL LOW DEVELOPING MONDAY AND
MOVING ACROSS THE WATERS TUESDAY. THE GFS IS SLOWER WITH THE COASTAL
LOW AND KEEPS IT FARTHER OFFSHORE. THE ECMWF IS FASTER WITH THE LOW
AND HUGS IT CLOSER TO THE COAST LINE. EASTERLY WINDS WILL HELP TO
ELEVATE TIDES AND WE WILL NEED TO MONITOR FOR ANY COASTAL FLOODING.
23
&&
.PREV DISCUSSION... /ISSUED 1130 AM CST THU NOV 21 2013/
DISCUSSION...
SEE AVIATION FOR 18Z TAF ISSUANCE.
AVIATION...
MANY THINGS IN CONSIDERATION WITH THE TAF PACKAGE THIS MORNING.
SHOWERS HAVE BEEN SCATTERED IN THE WESTERN HALF OF OUR CWA AND
BECOME MORE ISOLATED TOWARDS THE EAST. SHOWERS ARE FORMING OFF OF
ISENTROPIC LIFT OR UPGLIDE. MORE UPPER LEVEL CONVERGENCE EXISTS
OFF TO OUR EAST WHICH HAS LIMITED SHOWER PRODUCTION. IN GENERAL
TERMINALS IN OUR WESTERN AREAS HAVE THE BEST CHANCE OF SEEING RAIN
WITH TERMINALS TOWARDS THE EAST HAVING A LESSER CHANCE. THIS IS
SUPPORTED BY THE HRRR AND TEXAS TECH WRF MODELS. THE HRRR SEEMS TO
HAVE THE BEST HANDLE OF WHAT IS CURRENTLY GOING ON. HRRR HAS
PRECIP MOVING NORTHWARDS WITH MORE REDEVELOPMENT AT KCLL.
WIDESPREAD MVFR AND IFR CIGS TODAY WILL CONTINUE TO LOWER TOWARDS
IFR AND LIFR BY FRIDAY MORNING. THERE IS A SLIGHT CHANCE OF SOME
SEA FOG AS ECMWF AND NAM SHOWING EASTERLY WINDS TONIGHT. CHANCES
APPEARS LOW BUT GIVEN HIGH DEWPOINTS CAN`T RULE IT OUT.
A COLD FRONT CURRENTLY LOCATED IN THE TEXAS PANHANDLE WILL
CONTINUE TO PUSH SOUTHWARDS TODAY AND MAKE IT TO KCLL AROUND 5 TO
7AM. A LINE OF THUNDERSTORMS WILL BE WITH THE FRONT. BEST UPPER
LEVEL SUPPORT IS OFF TO OUR NORTH THOUGH SO LINE SHOULD BE
WEAKENING AS IT MOVES SOUTHWARDS. THE FRONT WILL MOST LIKELY BE
AT THE COAST AROUND 12 TO 3PM. THE EXACT TIMING WILL BE TRICKY
THOUGH AS FRONTS GENERALLY SLOW DOWN DURING THE DAY. WITH THIS
BEING SAID MODELS ARE SLOW GIVEN THE CURRENT FRONTAL POSITION. THE
TEXAS TECH WRF IS THE FASTEST BRINGING THE FRONT TO THE COAST
AROUND 1PM. BEHIND THE FRONT LIGHT RAIN AND SOME WIND WITH IFR TO
LIFR CONDITIONS CAN BE EXPECTED. 23
CLIMATE...
THE RECORD HIGH MINIMUM TEMPERATURE FOR COLLEGE STATION (CLL) TODAY
IS 67 DEGREES SET IN 1982. THE LOW TEMPERATURE THIS MORNING AT CLL
WAS 67 DEGREES. IF CLL`S TEMPERATURE DOES NOT FALL BELOW 67 BEFORE
MIDNIGHT...TODAY`S RECORD HIGH MINIMUM TEMPERATURE WILL BE TIED. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 56 56 38 45 36 / 70 70 50 40 20
HOUSTON (IAH) 69 70 43 51 41 / 50 70 60 50 20
GALVESTON (GLS) 69 75 50 55 45 / 40 70 60 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...42
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1205 PM CST THU NOV 21 2013
.AVIATION...
FOR THE 18Z TAFS...A DIFFICULT FORECAST FOR THE NEXT 24 HOURS. NORTH
WINDS OF 20-30KTS ARE EXPECTED THROUGH THE PERIOD. IFR CEILINGS AT
KAMA AND KDHT MAY FLIRT WITH LIFR HEIGHTS AT TIMES TODAY...THEN ARE
EXPECTED TO IMPROVE TO MVFR BY AROUND 03Z. CEILINGS AT ALL 3 TAF SITES
SHOULD THEN DEGRADE TO IFR AGAIN BETWEEN 09Z AND 12Z FRIDAY. PERIODS
OF LIGHT FREEZING DRIZZLE AND FREEZING MIST OR FOG WILL GIVE WAY TO
FREEZING DRIZZLE AND SNOW GRAINS OR FLURRIES BETWEEN 03Z AND 06Z
FRIDAY. THE LOWEST VISIBILITIES WILL GENERALLY OCCUR WITH HEAVIER
PERIODS OF PRECIPITATION. CONFIDENCE IN THE EXACT TIMING OF
PRECIPITATION REMAINS LOW...THOUGH POOR CONDITIONS WILL PERSIST PAST
THE END OF THIS TAF PERIOD.
NF
&&
.PREV DISCUSSION... /ISSUED 1148 AM CST THU NOV 21 2013/
UPDATE...
ARCTIC COLD FRONT HAS PLOWED THROUGH MOST OF THE AREA THIS
MORNING...AND IS CURRENTLY PUSHING THROUGH THE FAR SOUTHEAST TX
PANHANDLE. TEMPERATURES AT 11 AM RANGING FROM THE UPPER 20S IN THE
WESTERN OK PANHANDLE TO THE UPPER 60S IN THE SOUTHEAST TX
PANHANDLE...AN IMPRESSIVE 40 DEGREE RANGE. STRATUS HAS SPILLED SOUTH
BEHIND THE FRONT IN THE STRONG COLD AIR ADVECTION...WITH SOME POST-
FRONTAL FOG AS WELL AND A FEW REPORTS OF SOME MIST/LIGHT DRIZZLE. FOG
HAS BEEN MOST PREVALENT IMMEDIATELY BEHIND THE FRONT...WITH SOME LOW-
LEVEL DRIER AIR FILTERING IN FROM THE NORTH ALLOWING FOR VSBYS TO COME
UP SOME FARTHER NORTH OF THE FRONT.
FOR THE REST OF THIS AFTERNOON...TEMPS WILL CONTINUE TO FALL INTO THE
20S AND 30S AS STRONG COLD AIR ADVECTION PERSISTS. ANY PRECIPITATION
THROUGH LATE THIS AFTERNOON IS EXPECTED TO BE VERY LIGHT. MID-LEVELS
STAY DRY THROUGH THIS TIME...SO ANY LIGHT PRECIPITATION WILL LIKELY
BE IN THE FORM OF DRIZZLE OR FREEZING DRIZZLE...WITH THE BETTER
CHANCES OF THIS ACROSS THE NORTHERN HALF OF THE AREA WHERE THE LOW-
LEVEL MOIST LAYER WILL DEEPEN SOONER. FARTHER SOUTH...THINK SOME
FOG/FREEZING FOG WILL BE THE MORE LIKELY SCENARIO FOR THE REST OF THE
AFTERNOON UNTIL THE MOIST LAYER CAN DEEPEN FURTHER. FORECAST
SOUNDINGS SHOW TEMPERATURES IN THE LOW-LEVEL MOIST LAYER POSSIBLY
DIPPING TO AROUND -6C OR LOWER ACROSS THE OK PANHANDLE LATE THIS
AFTERNOON...WHICH MAY BE COLD ENOUGH TO SUPPORT SOME ICE CRYSTAL
GROWTH AND RESULTANT VERY LIGHT SNOW/FLURRIES. GIVEN THE LIGHT
NATURE OF ANY PRECIP THROUGH THE AFTERNOON AND WARM GROUND TEMPS TO
START THE DAY...EXPECT ANY IMPACTS TO BE FAIRLY MINIMAL THROUGH THIS
AFTERNOON AND THUS WILL KEEP THE WINTER WEATHER ADVISORY START TIME
AT 6 PM THIS EVENING.
KB
PREV DISCUSSION... /ISSUED 523 AM CST THU NOV 21 2013/
DISCUSSION...
MULTIPLE CHANCES TO SEE A WINTRY MIX OF PRECIPITATION STILL EXPECTED
FROM TODAY THROUGH EARLY NEXT WEEK.
THE ARCTIC COLD FRONT CONTINUES TO SURGE SOUTHWARD ABOUT 3 HOURS
AHEAD OF SCHEDULE FROM YESTERDAY. THE MODELS WITH THE CLOSEST
DEPICTION OF THE FASTER FRONTAL TIMING HAS BEEN THE RUC AND THE 00Z
GFS. WITH A BLEND OF THESE TWO MODELS THE FRONT IS EXPECTED TO BE
MOSTLY THROUGH THE PANHANDLES BY NOON TODAY. THIS WILL CAUSE HIGH
TEMPERATURES TO BE COLDER THAN PREVIOUSLY ADVERTISED. THE MOST
NOTICEABLE CHANCE IN TEMPERATURE FROM YESTERDAY WILL BE IN THE
OKLAHOMA PANHANDLE WHICH REACHED INTO THE 60S BUT WILL STRUGGLE TO
REACH THE 40 DEGREE MARK TODAY.
THE FORECAST STILL SHOWS DECENT CHANCES FOR THE TEXAS AND OKLAHOMA
PANHANDLE TO SEE SOME FORM OF WINTRY PRECIPITATION BETWEEN NOW AND
SATURDAY MORNING. THE QUESTION WILL BE WHERE CAN WE GET ENOUGH
MOISTURE IN THE DENDRITIC SNOW GROWTH ZONE TO MAKE A SOLID TRANSITION
TO MOSTLY OR ALL SNOW. THE BEST AREA FOR THIS TO HAPPEN IS EXPECTED
TO BE NORTH OF A DALHART TO ELKHART LINE. THE REMAINDER OF THE AREA
WILL HAVE A CHANCE TO SEE A FEW FLAKES BUT FREEZING DRIZZLE AND OR
FREEZING RAIN SEEMS A MORE LIKELY FORECAST. WHILE WE ARE EXPECTING
ANY WINTRY PRECIPITATION ACCUMULATIONS TO REMAIN LIGHT LOCATIONS NORTH
OF THE DALHART TO ELKHART LINE COULD SEE BETWEEN 1 TO 3 INCHES OF
SNOW WHILE THERE WILL BE A CHANCE FOR LIGHT ICE ACCUMULATIONS ACROSS
ELEVATED SURFACES ACROSS THE PANHANDLES.
SATURDAY REMAINS THE LULL DAY BEFORE A CLOSED UPPER LEVEL LOW EJECTS
FROM THE DESERT SOUTHWEST. AS THIS LOW MOVES ACROSS THE PANHANDLES WE
COULD SEE ANOTHER ROUND OF WINTRY PRECIPITATION WHICH MAY NEED AN
ADVISORY FOR THE SATURDAY NIGHT AND SUNDAY TIME FRAME. BY MONDAY DRIER
CONDITIONS BEGIN TO SETTLE IN FOR THE LATER HALF OF THIS FORECAST
CYCLE.
FIRE WEATHER...
NEITHER ELEVATED NOR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
FOR THE NEXT SEVEN DAYS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
06/02
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1148 AM CST THU NOV 21 2013
.UPDATE...
ARCTIC COLD FRONT HAS PLOWED THROUGH MOST OF THE AREA THIS
MORNING...AND IS CURRENTLY PUSHING THROUGH THE FAR SOUTHEAST TX
PANHANDLE. TEMPERATURES AT 11 AM RANGING FROM THE UPPER 20S IN THE
WESTERN OK PANHANDLE TO THE UPPER 60S IN THE SOUTHEAST TX
PANHANDLE...AN IMPRESSIVE 40 DEGREE RANGE. STRATUS HAS SPILLED SOUTH
BEHIND THE FRONT IN THE STRONG COLD AIR ADVECTION...WITH SOME POST-
FRONTAL FOG AS WELL AND A FEW REPORTS OF SOME MIST/LIGHT DRIZZLE. FOG
HAS BEEN MOST PREVALENT IMMEDIATELY BEHIND THE FRONT...WITH SOME LOW-
LEVEL DRIER AIR FILTERING IN FROM THE NORTH ALLOWING FOR VSBYS TO COME
UP SOME FARTHER NORTH OF THE FRONT.
FOR THE REST OF THIS AFTERNOON...TEMPS WILL CONTINUE TO FALL INTO THE
20S AND 30S AS STRONG COLD AIR ADVECTION PERSISTS. ANY PRECIPITATION
THROUGH LATE THIS AFTERNOON IS EXPECTED TO BE VERY LIGHT. MID-LEVELS
STAY DRY THROUGH THIS TIME...SO ANY LIGHT PRECIPITATION WILL LIKELY
BE IN THE FORM OF DRIZZLE OR FREEZING DRIZZLE...WITH THE BETTER
CHANCES OF THIS ACROSS THE NORTHERN HALF OF THE AREA WHERE THE LOW-
LEVEL MOIST LAYER WILL DEEPEN SOONER. FARTHER SOUTH...THINK SOME
FOG/FREEZING FOG WILL BE THE MORE LIKELY SCENARIO FOR THE REST OF THE
AFTERNOON UNTIL THE MOIST LAYER CAN DEEPEN FURTHER. FORECAST
SOUNDINGS SHOW TEMPERATURES IN THE LOW-LEVEL MOIST LAYER POSSIBLY
DIPPING TO AROUND -6C OR LOWER ACROSS THE OK PANHANDLE LATE THIS
AFTERNOON...WHICH MAY BE COLD ENOUGH TO SUPPORT SOME ICE CRYSTAL
GROWTH AND RESULTANT VERY LIGHT SNOW/FLURRIES. GIVEN THE LIGHT
NATURE OF ANY PRECIP THROUGH THE AFTERNOON AND WARM GROUND TEMPS TO
START THE DAY...EXPECT ANY IMPACTS TO BE FAIRLY MINIMAL THROUGH THIS
AFTERNOON AND THUS WILL KEEP THE WINTER WEATHER ADVISORY START TIME
AT 6 PM THIS EVENING.
KB
&&
.PREV DISCUSSION... /ISSUED 523 AM CST THU NOV 21 2013/
DISCUSSION...
MULTIPLE CHANCES TO SEE A WINTRY MIX OF PRECIPITATION STILL EXPECTED
FROM TODAY THROUGH EARLY NEXT WEEK.
THE ARCTIC COLD FRONT CONTINUES TO SURGE SOUTHWARD ABOUT 3 HOURS
AHEAD OF SCHEDULE FROM YESTERDAY. THE MODELS WITH THE CLOSEST
DEPICTION OF THE FASTER FRONTAL TIMING HAS BEEN THE RUC AND THE 00Z
GFS. WITH A BLEND OF THESE TWO MODELS THE FRONT IS EXPECTED TO BE
MOSTLY THROUGH THE PANHANDLES BY NOON TODAY. THIS WILL CAUSE HIGH
TEMPERATURES TO BE COLDER THAN PREVIOUSLY ADVERTISED. THE MOST
NOTICEABLE CHANCE IN TEMPERATURE FROM YESTERDAY WILL BE IN THE
OKLAHOMA PANHANDLE WHICH REACHED INTO THE 60S BUT WILL STRUGGLE TO
REACH THE 40 DEGREE MARK TODAY.
THE FORECAST STILL SHOWS DECENT CHANCES FOR THE TEXAS AND OKLAHOMA
PANHANDLE TO SEE SOME FORM OF WINTRY PRECIPITATION BETWEEN NOW AND
SATURDAY MORNING. THE QUESTION WILL BE WHERE CAN WE GET ENOUGH
MOISTURE IN THE DENDRITIC SNOW GROWTH ZONE TO MAKE A SOLID TRANSITION
TO MOSTLY OR ALL SNOW. THE BEST AREA FOR THIS TO HAPPEN IS EXPECTED
TO BE NORTH OF A DALHART TO ELKHART LINE. THE REMAINDER OF THE AREA
WILL HAVE A CHANCE TO SEE A FEW FLAKES BUT FREEZING DRIZZLE AND OR
FREEZING RAIN SEEMS A MORE LIKELY FORECAST. WHILE WE ARE EXPECTING
ANY WINTRY PRECIPITATION ACCUMULATIONS TO REMAIN LIGHT LOCATIONS NORTH
OF THE DALHART TO ELKHART LINE COULD SEE BETWEEN 1 TO 3 INCHES OF
SNOW WHILE THERE WILL BE A CHANCE FOR LIGHT ICE ACCUMULATIONS ACROSS
ELEVATED SURFACES ACROSS THE PANHANDLES.
SATURDAY REMAINS THE LULL DAY BEFORE A CLOSED UPPER LEVEL LOW EJECTS
FROM THE DESERT SOUTHWEST. AS THIS LOW MOVES ACROSS THE PANHANDLES WE
COULD SEE ANOTHER ROUND OF WINTRY PRECIPITATION WHICH MAY NEED AN
ADVISORY FOR THE SATURDAY NIGHT AND SUNDAY TIME FRAME. BY MONDAY DRIER
CONDITIONS BEGIN TO SETTLE IN FOR THE LATER HALF OF THIS FORECAST
CYCLE.
FIRE WEATHER...
NEITHER ELEVATED NOR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
FOR THE NEXT SEVEN DAYS.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...
COLLINGSWORTH...DALLAM...DEAF SMITH...DONLEY...GRAY...
HANSFORD...HARTLEY...HEMPHILL...HUTCHINSON...LIPSCOMB...
MOORE...OCHILTREE...OLDHAM...POTTER...RANDALL...ROBERTS...
SHERMAN...WHEELER.
OK...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
SATURDAY FOR THE FOLLOWING ZONES: BEAVER...CIMARRON...TEXAS.
&&
$$
08/02
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1130 AM CST THU NOV 21 2013
.DISCUSSION...
SEE AVIATION FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
MANY THINGS IN CONSIDERATION WITH THE TAF PACKAGE THIS MORNING.
SHOWERS HAVE BEEN SCATTERED IN THE WESTERN HALF OF OUR CWA AND
BECOME MORE ISOLATED TOWARDS THE EAST. SHOWERS ARE FORMING OFF OF
ISENTROPIC LIFT OR UPGLIDE. MORE UPPER LEVEL CONVERGENCE EXISTS
OFF TO OUR EAST WHICH HAS LIMITED SHOWER PRODUCTION. IN GENERAL
TERMINALS IN OUR WESTERN AREAS HAVE THE BEST CHANCE OF SEEING RAIN
WITH TERMINALS TOWARDS THE EAST HAVING A LESSER CHANCE. THIS IS
SUPPORTED BY THE HRRR AND TEXAS TECH WRF MODELS. THE HRRR SEEMS TO
HAVE THE BEST HANDLE OF WHAT IS CURRENTLY GOING ON. HRRR HAS
PRECIP MOVING NORTHWARDS WITH MORE REDEVELOPMENT AT KCLL.
WIDESPREAD MVFR AND IFR CIGS TODAY WILL CONTINUE TO LOWER TOWARDS
IFR AND LIFR BY FRIDAY MORNING. THERE IS A SLIGHT CHANCE OF SOME
SEA FOG AS ECMWF AND NAM SHOWING EASTERLY WINDS TONIGHT. CHANCES
APPEARS LOW BUT GIVEN HIGH DEWPOINTS CAN`T RULE IT OUT.
A COLD FRONT CURRENTLY LOCATED IN THE TEXAS PANHANDLE WILL
CONTINUE TO PUSH SOUTHWARDS TODAY AND MAKE IT TO KCLL AROUND 5 TO
7AM. A LINE OF THUNDERSTORMS WILL BE WITH THE FRONT. BEST UPPER
LEVEL SUPPORT IS OFF TO OUR NORTH THOUGH SO LINE SHOULD BE
WEAKENING AS IT MOVES SOUTHWARDS. THE FRONT WILL MOST LIKELY BE
AT THE COAST AROUND 12 TO 3PM. THE EXACT TIMING WILL BE TRICKY
THOUGH AS FRONTS GENERALLY SLOW DOWN DURING THE DAY. WITH THIS
BEING SAID MODELS ARE SLOW GIVEN THE CURRENT FRONTAL POSITION. THE
TEXAS TECH WRF IS THE FASTEST BRINGING THE FRONT TO THE COAST
AROUND 1PM. BEHIND THE FRONT LIGHT RAIN AND SOME WIND WITH IFR TO
LIFR CONDITIONS CAN BE EXPECTED. 23
&&
.PREV DISCUSSION... /ISSUED 954 AM CST THU NOV 21 2013/
DISCUSSION...
MADE SOME MINOR CHANGES TO THE FORECAST...WITH SOME UPWARD ADJUSTMENTS
TO DEW POINTS (READINGS ALREADY IN THE 70S ALONG AND SOUTH OF A LINE
FROM COLLEGE STATION TO HOUSTON TO GALVESTON) AND SOME TWEAKS TO TODAY`S
POPS. OTHER THAN THAT...FORECAST LOOKS TO BE ON TRACK. THE STRONG COLD
FRONT IS CURRENTLY MOVING SOUTHWARD INTO THE NORTHERN OKLAHOMA AREA...AND
THIS IS THE BOUNDARY THAT WILL BE MOVING THROUGH OUR AREA DURING THE
DAY TOMORROW. STILL EXPECTING A SHARP TEMPERATURE DROP TO OCCUR BEHIND
THE FRONT WITH READINGS LIKELY FALLING INTO THE 40S AND 50S NORTH AND
CENTRAL BEFORE SUNSET. THERE WILL ALSO BE A GOOD SHOT OF RAINFALL WITH
THE FRONT. THE WEEKEND LOOKS COLD...AND NO REAL WARMUP IS ANTICIPATED
UNTIL AROUND THE END OF NEXT WEEK. THANKSGIVING IS STILL LOOKING DRY.
42
CLIMATE...
THE RECORD HIGH MINIMUM TEMPERATURE FOR COLLEGE STATION (CLL) TODAY
IS 67 DEGREES SET IN 1982. THE LOW TEMPERATURE THIS MORNING AT CLL
WAS 67 DEGREES. IF CLL`S TEMPERATURE DOES NOT FALL BELOW 67 BEFORE
MIDNIGHT...TODAY`S RECORD HIGH MINIMUM TEMPERATURE WILL BE TIED. 42
PREV DISCUSSION... /ISSUED 606 AM CST THU NOV 21 2013/
DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION...
AVIATION...
GULF MOISTURE CONTINUES TO INCREASE OVER SE TX THIS MORNING WITH
SOME SHOWER ACTIVITY. LIFR/IFR TO MVFR CIGS HAVE BEEN WIDESPREAD
THIS MORNING. MOST TERMINALS ARE AT IFR CIGS WITH MAINLY THE
HOUSTON TERMINALS AND KGLS BEING THE EXCEPTIONS. EXPECT CIGS TO
IMPROVE LATE THIS MORNING BUT WRF/HRRR HINT AT INCREASE IN
COVERAGE OF SHOWERS. COULD GET SOME MVFR/VFR CIGS THIS AFTERNOON
BEFORE CIGS CRASH BACK TO IFR OR EVEN LIFR FOR THE OVERNIGHT.
MODELS SEEM TO BE SPEEDING UP THE FRONT AS EXPECTED FOR EARLY
FRIDAY. FRONT MAINLY IMPACT KCLL BEFORE 12Z FRI AND THEN BEFORE
18Z FRI IN THE 30HR KIAH TAF. THE UPCOMING 18Z TAFS WILL REFLECT
THE FRONTAL PASSAGE AND EXPECTED TSRA.
KCLL/KUTS/KCXO...LOOKS LIKE IFR CIGS THROUGH THE MORNING AND
AFTERNOON AND IMPROVING LATE. SHOWERS POSSIBLE DURING THIS TIME AS
WELL. THINK THERE COULD BE A BREAK IN ACTIVITY FROM 20-21Z THROUGH
01Z FRI. CIGS WILL THEN BEGIN TO CRASH. CONVECTION IMPACT KCLL
AFTER 05Z WITH TSRA LIKELY AT TERMINAL BEFORE 12Z FRI WITH THE
FRONT.
KIAH/KHOU/KSGR...MAINLY MVFR CIGS THIS MORNING INTO THE AFTERNOON
WITH SHOWERS DEVELOPING. EXPECT THERE TO BE SOMEWHAT OF A BREAK IN
THE LATE AFTERNOON INTO THE EVENING BEFORE CIGS GO BACK DOWN TO
MVFR/IFR LEVELS. MAY SEEN LIFR CIGS WITH WINDS DECREASING
OVERNIGHT AS COLD FRONT APPROACHES. FRONT SHOULD REACH KIAH AROUND
15-18Z FRI WITH TSRA LIKELY.
KLBX/KGLS...AGAIN MVFR/IFR CIGS BUT LOOKS LIKE LESS CLOUD COVER AT
GLS FOR NOW. MAY GET SOME SHOWER ACTIVITY INCREASE LIKE MOST
INLAND TERMINALS. DO THINK MVFR/IFR CIGS LIKELY IN THE EVENING AND
PERHAPS PERIODS OF LIFR CIGS OVERNIGHT. WILL NEED TO WATCH KGLS
FOR SEA FOG FORMATION AND VSBY BECOMING MORE RESTRICTED THAN 4SM.
39
PREV DISCUSSION... /ISSUED 416 AM CST THU NOV 21 2013/
DISCUSSION...
A COUPLE OF RAINY PERIODS WILL AFFECT SE TX OVER THE NEXT FIVE
DAYS. A COLD FRONT WHICH WAS MOVING SOUTHWARD ACROSS THE NORTHERN
PLAINS EARLY THIS MORNING WILL PUSH INTO THE STATE TONIGHT AND
ACROSS SE TX ON FRIDAY. ISENTROPIC LIFT WILL KEEP CLOUDS AND RAIN
CHANCES OVERHEAD THROUGH SATURDAY WITH A BRIEF BREAK FROM THE
RAINY CONDITIONS SATURDAY NIGHT INTO SUNDAY. HOWEVER...THE SECOND
RAIN EVENT WILL OCCUR SUNDAY NIGHT THROUGH TUESDAY AS A STRONG
UPPER LEVEL LOW MOVES ACROSS THE STATE AND A SURFACE LOW MOVES UP
THE COAST.
A FAIRLY DEEP MOISTURE LAYER WILL BE FOCUSED BY WARM AIR ADVECTION
TO HELP BRING SCATTERED RAIN SHOWERS TODAY. THERE IS A SEA FOG
THREAT TONIGHT -- SEE THE MARINE SECTION BELOW FOR MORE DETAILS.
EXPECT WIDESPREAD RAIN AND ISOLATED THUNDERSTORMS TO BEGIN OUT
WEST LATE TONIGHT AND AREA WIDE ON FRIDAY AS THE COLD FRONT MOVES
THROUGH. MODEL PW/S GET AS HIGH AS 1.8 INCHES...ABOUT 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. GOING FOR JUST
ISOLATED THUNDER GIVEN THE LACK UP UPPER LEVEL SUPPORT. BOTH THE
GFS AND ECMWF ADVERTISE A BREAK ON SATURDAY NIGHT AND SUNDAY.
SUNDAY NIGHT AND EARLY MONDAY MORNING WILL THEN LIKELY BE THE
COLDEST NIGHT OF THE PERIOD AS TEMPERATURES FALL INTO THE 30S OVER
MOST OF THE INLAND COUNTIES...WITH MID 30S EXPECTED NORTH OF A
LINE FROM BRENHAM TO LIBERTY.
CHILLY AND RAINY CONDITIONS ARE LIKELY ON MONDAY AS THE SURFACE
LOW GETS ORGANIZED OFF BROWNSVILLE AND MOVES UP THE COAST. THE GFS
AND ECMWF DIFFER A BIT ON THE TIMING AND LENGTH OF THE EVENT...BUT
THINK THAT THE BULK OF THE RAINFALL WILL PUSH EAST OF THE STATE
BY TUESDAY. KEPT A CHANCE OF RAIN ON TUESDAY WITH THE UPPER TROUGH
PUSHING EASTWARD OVERHEAD.
MARINE...
SFC LOW OVER THE PLAINS WILL KEEP SE WINDS IN PLACE TODAY AT
MODERATE LEVELS. SEAS SHOULD BE SLOWLY SUBSIDING BUT SHOULD REMAIN
AT MODERATE LEVELS. WINDS WILL CONTINUE TO DECREASE THROUGH THE
EVENING HOURS INTO FRIDAY. STRONG COLD FRONT IS STILL ON TRACK TO
PUSH THROUGH THE COASTAL WATERS FRI NIGHT INTO SATURDAY. LIKELY
HAVE ADVISORY CONDITIONS WITH GUSTS TO NEAR GALE FORCE. THERE MAY
BE AN COUPLE OF HOURS WITH WIND GUSTS TO GALE FORCE BUT NOT ENOUGH
TO NEED A GALE WATCH/WARNING AT THIS TIME. LIKELY HAVE 20 TO 30KT
WINDS WITH GUSTS TO 35KTS. SEAS IN OFFSHORE AREAS WILL BUILD TO
AROUND 8 TO 11 FEET BY SAT AFTERNOON. STRONG NORTHERLY WINDS WILL
PERSIST INTO SUNDAY BUT TURN MORE TO THE NORTHEAST.
MODELS BECOMING A MORE CONSISTENT WITH THE DEVELOPMENT OF A
COASTAL LOW SUN NIGHT INTO MON AS A STRONG UPPER LEVEL SYSTEM
MOVES THROUGH TX. COASTAL LOW SHOULD REMAIN OFF THE COAST BUT
SUPPORT STRONG EASTERLY WINDS. THIS SHOULD ELEVATE TIDES AND WILL
NEED TO MONITOR FOR ANY COASTAL FLOODING. AGAIN THIS IS STILL FOR
EARLY NEXT WEEK AND NEEDS TO BE WATCHED CLOSELY FOR ANY CHANGES.
SEA FOG POTENTIAL...ANOTHER CHALLENGING FORECAST FOR SEA FOG. THE
PROBLEMS FOR SEA FOG FORMATION SEEM TO BE SLIGHTLY HIGHER WATER
TEMPS THAN THE PREVIOUS SEA FOG EVENT AND NOT QUITE AS DEEP
MOISTURE. THAT SAID...SOME OBS IN THE GULF SHOW LOW/MID 70
DEWPOINT TEMPS WHICH SHOULD ADVECT TOWARDS THE COAST. THINK BEST
CHANCES FOR FOG FORMATION WILL BE LATE THIS EVENING THROUGH FRIDAY
MORNING AHEAD OF THE FRONT. FOG MAY THICKEN AGAIN FRIDAY EVENING
JUST AHEAD OF THE FRONT BUT ONCE THE FRONT PUSHES THROUGH...THREAT
FOR FOG WILL END.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 60 61 40 49 / 40 60 80 40 30
HOUSTON (IAH) 79 69 69 45 55 / 40 50 70 60 40
GALVESTON (GLS) 77 69 71 52 59 / 40 30 70 60 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
327 PM CST THU NOV 21 2013
.SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
LATEST RUNS OF HRRR AND 4 KM WRF/NMM MODELS ARE INDICATING THAT THE
MOISTURE WILL BE DELAYED UNTIL LATER THIS EVENING FOR THE ARRIVAL OF
THE EXPECTED AREA OF PRECIPITATION. CURRENT AREA OF PRECIPITATION
OVER SOUTH CENTRAL IOWA MAY STRUGGLE TO MAKE IT HERE...AS THIS WILL
FIGHT DRY LOW LEVELS OVER THE AREA. FOR NOW...WILL PUSH BACK ARRIVAL
OF PRECIPITATION A BIT THIS EVENING...AS WELL AS THE CHANGEOVER TO
LIGHT SNOW LATER TONIGHT.
SYNOPTIC AND MESOSCALE MODELS ARE SLOWING THE SATURATION OF THE AIR
COLUMN UNTIL MID TO LATE EVENING FROM SOUTHWEST TO NORTHEAST. AREA
OF GOOD 850MB TO 700MB FRONTOGENESIS RESPONSE WILL PUSH EAST
SOUTHEAST THROUGH THE AREA BETWEEN 06Z AND 15Z FRIDAY...DRIVING THE
MAIN AREA OF PRECIPITATION. BEST UPWARD VERTICAL MOTION WILL BE OVER
THE NORTHWEST HALF OF THE AREA LATER TONIGHT...WITH AREAS TO THE
SOUTHEAST SEEING LESS.
AIR COLUMN WILL COOL FROM THE TOP DOWN AS COLD AIR ADVECTION KICKS
IN TONIGHT...SO WILL CONTINUE THE TRANSITION FROM RAIN OR RAIN/SNOW
MIX TO ALL LIGHT SNOW FROM NORTHWEST TO SOUTHEAST. EXPECTING AROUND
0.5 INCHES ON GRASSY AREAS FROM DARLINGTON TO MADISON TO SHEBOYGAN
AND NORTHWESTWARD...WITH LOWER AMOUNTS TO THE SOUTHEAST.
MILWAUKEE...RACINE AND KENOSHA MAY ONLY SEE A DUSTING AT BEST.
CLOUDS WILL GRADUALLY MIX OUT LATER ON FRIDAY...WITH COLD AIR
ADVECTION CONTINUING. WINDS WILL GRADUALLY WEAKEN AS THE DAY GOES
ON...BUT TEMPERATURES WILL STRUGGLE TO RISE MUCH OUT OF THE LOWER
TO MID 30S.
FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE HIGH
LOW PRESSURE MOVING EAST ACROSS THE NORTHERN GREAT LAKES AND NEW
ENGLAND WILL SWEEP AN ARCTIC COLD FRONT ACROSS THE REGION FRI NT
INTO SAT. 850 MB TEMPS TO DROP TO -17C ON SAT AND SCT-BKN
STRATOCUMULUS CLOUDS ARE EXPECTED. HIGH TEMPS ONLY IN THE 20S
ARE FORECAST AND BRISK WINDS WILL MAKE FOR WIND CHILLS IN THE
SINGLE DIGITS AND TEENS ALL WEEKEND. ARCTIC HIGH PRESSURE TO THEN
MOVE FROM THE NRN PLAINS TO THE UPPER MS RIVER VALLEY BY 12Z SUN.
LIGHTER WIND AND RADIATIONAL COOLING WILL SUPPORT VERY COLD TEMPS
IN THE SINGLE DIGITS OVER SOUTH CENTRAL WI AND TEENS IN ERN WI.
THE HIGH WILL MOVE EAST FOR SUN AFTERNOON WITH SWLY WINDS AND WARM
ADVECTION BEGINNING. HIGH TEMPS ONCE AGAIN STUCK IN THE 20S.
.LONG TERM...
SUNDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM
SWLY WINDS AND WARM ADVECTION WILL CONTINUE SUN NT INTO MON AS LOW
PRESSURE ONCE AGAIN TRACKS EAST ACROSS SRN CANADA. THERE ARE SMALL
CHANCES OF LGT SNOW WITH THE WARM ADVECTION DURING THIS TIME. A
COLD FRONT...WEAKER THAN PREVIOUS FRONTS...WILL MOVE ACROSS THE
REGION MON NT AND WILL BE ABLE TO MAINTAIN BELOW NORMAL TEMPS.
NWLY WINDS WILL THEN PREVAIL TUE-WED WITH A POLAR HIGH FINALLY
ARRIVING OVER WI FOR THANKSGIVING DAY. MAINLY DRY AND COLD
CONDITIONS ARE EXPECTED.
&&
.AVIATION/00Z TAFS/...
MVFR CEILINGS ARE EXPECTED TO SPREAD EAST ACROSS THE EASTERN SITES
BY EARLY THIS EVENING. MADISON WILL SEE MVFR CEILINGS AS WELL. WINDS
WILL BECOME NORTH NORTHWESTERLY THIS EVENING...GRADUALLY BECOMING
STRONGER AS THE NIGHT GOES ON.
EXPECTING LIGHT RAIN WITH MVFR VISIBILITIES AND IFR CEILINGS TO MOVE
INTO MADISON AROUND 03Z FRIDAY...AND AROUND 05Z FRIDAY AT THE
EASTERN SITES. THE LIGHT RAIN SHOULD MIX WITH LIGHT SNOW FOR A FEW
HOURS STARTING BETWEEN 06Z TO 08Z FRIDAY...BEFORE BECOMING ALL LIGHT
SNOW BETWEEN 08Z AND 10Z FRIDAY.
ANY LINGERING LIGHT SNOW SHOULD END BETWEEN 13Z TO 15Z FRIDAY WEST
TO EAST. GUSTY NORTH NORTHWEST WINDS SHOULD OCCUR BY 10Z
FRIDAY...LINGERING THROUGH FRIDAY.
SNOW ACCUMULATIONS ON GRASSY AREAS SHOULD BE AROUND 0.5 INCHES AT
MADISON...WITH A DUSTING AT BEST AT THE EASTERN SITES. RUNWAYS
SHOULD REMAIN JUST WET DURING THIS TIME...AS GROUND TEMPERATURES
REMAIN AROUND OR JUST ABOVE FREEZING DURING THE LIGHT SNOW. MVFR
CLOUDS SHOULD GRADUALLY MIX OUT IN THE AFTERNOON...WITH
NORTH NORTHWEST WINDS GRADUALLY WEAKENING BY LATE AFTERNOON.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM LATE TONIGHT INTO LATE
FRIDAY NIGHT ACROSS THE NEARSHORE WATERS. A TIGHT PRESSURE GRADIENT
WILL DEVELOP WITH THE COLD AIRMASS MOVING INTO THE REGION DURING
THIS TIME...GENERATING GUSTY NORTH NORTHWEST WINDS. THESE WINDS WILL
GENERATE HIGH WAVES UP TO 4 TO 7 FEET FRIDAY.
THE SMALL CRAFT ADVISORY WILL LIKELY NEED TO BE EXTENDED THROUGH
SATURDAY NIGHT...AS ANOTHER SHOT OF COLD AIR SURGES INTO THE AREA.
NORTHWEST WIND GUSTS MAY REACH 35 KNOTS AT TIMES...SO A GALE WATCH
WOULD NEED TO BE CONSIDERED AS WELL. HIGH WAVES WOULD REMAIN TOWARD
AND OVER THE OPEN WATERS.
WINDS WILL BE NEAR SMALL CRAFT ADVISORY LEVELS AT TIMES INTO EARLY
NEXT WEEK...AS THE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE AREA.
HIGH WAVES MAY OCCUR TOWARD THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO 6 AM CST SATURDAY FOR
LMZ643>646.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD
FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
115 PM CST THU NOV 21 2013
.UPDATE...
LATEST RUNS OF HRRR AND 4 KM WRF/NMM MODELS ARE INDICATING THAT
THE MOISTURE WILL BE DELAYED UNTIL THIS EVENING FOR THE ARRIVAL OF
THE EXPECTED AREA OF PRECIPITATION. THEY KEEP THE AREA FAIRLY DRY
THROUGH 00Z FRIDAY. THUS...WILL LIKELY BE TRENDING DOWNWARD WITH
POPS LATER THIS AFTERNOON. CLOUDY SKIES WILL CONTINUE...KEEPING
TEMPERATURES IN THE LOWER TO MID 40S.
WILL LIKELY PUSH BACK ARRIVAL OF PRECIPITATION THIS EVENING...AS
WELL AS THE CHANGEOVER TO LIGHT SNOW LATER TONIGHT. SYNOPTIC AND
MESOSCALE MODELS ARE SLOWING THE SATURATION OF THE AIR COLUMN
UNTIL MID TO LATE EVENING FROM SOUTHWEST TO NORTHEAST. AREA OF
GOOD 850MB TO 700MB FRONTOGENESIS RESPONSE WILL PUSH EAST
SOUTHEAST THROUGH THE AREA BETWEEN 06Z AND 15Z FRIDAY...DRIVING
THE MAIN AREA OF PRECIPITATION.
AIR COLUMN WILL COOL FROM THE TOP DOWN AS COLD AIR ADVECTION
KICKS IN TONIGHT...SO WILL CONTINUE THE TRANSITION FROM RAIN OR
RAIN/SNOW MIX TO ALL LIGHT SNOW FROM NORTHWEST TO SOUTHEAST. STILL
EXPECTING UP TO AN INCH NEAR THE WISCONSIN DELLS AREA...TO A FEW
TENTHS OF AN INCH TOWARD KENOSHA.
&&
.AVIATION/18Z TAFS/...
VFR CEILINGS ARE EXPECTED AT THE EASTERN SITES THIS AFTERNOON AND
EVENING. MADISON MAY SEE SOME MVFR/IFR CEILINGS PERIODICALLY...BUT
SHOULD COME UP TO VFR AS WELL. LIGHT AND VARIABLE WINDS THIS
AFTERNOON WILL GRADUALLY BECOME NORTH NORTHWEST THIS
EVENING...WITH THE PASSAGE OF THE COLD FRONT.
EXPECTING LIGHT RAIN WITH MVFR VISIBILITIES AND IFR CEILINGS TO
MOVE INTO TAF SITES AT 03Z AT MADISON...AND AROUND 05Z AT THE
EASTERN SITES. THE LIGHT RAIN SHOULD MIX WITH LIGHT SNOW FOR AN
HOUR OR TWO BEGINNING BETWEEN 06Z AND 08Z FRIDAY...BEFORE
BECOMING ALL LIGHT SNOW BETWEEN 08Z AND 10Z FRIDAY.
THE LIGHT SNOW SHOULD END BETWEEN 14Z TO 16Z FRIDAY WEST TO EAST.
GUSTY NORTH NORTHWEST WINDS SHOULD OCCUR BY 10Z FRIDAY...LINGERING
THROUGH FRIDAY.
SNOW ACCUMULATIONS ON GRASSY AREAS SHOULD BE AROUND 0.5 INCHES AT
MADISON...WITH A DUSTING AT THE EASTERN SITES. RUNWAYS SHOULD
REMAIN JUST WET DURING THIS TIME...AS GROUND TEMPERATURES REMAIN
AROUND OR JUST ABOVE FREEZING DURING THE LIGHT SNOW. MVFR CLOUDS
SHOULD GRADUALLY MIX OUT IN THE AFTERNOON.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM LATE TONIGHT INTO LATE
FRIDAY NIGHT ACROSS THE NEARSHORE WATERS. A TIGHT PRESSURE
GRADIENT WILL DEVELOP WITH THE COLD AIRMASS MOVING INTO THE REGION
DURING THIS TIME...GENERATING GUSTY NORTH NORTHWEST WINDS. THESE
WINDS WILL GENERATE HIGH WAVES UP TO 4 TO 7 FEET FRIDAY.
THE SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED THROUGH SATURDAY
NIGHT...AS ANOTHER SHOT OF COLD AIR SURGES INTO THE AREA.
NORTHWEST WIND GUSTS MAY REACH 35 KNOTS AT TIMES...SO A GALE
WATCH WOULD NEED TO BE CONSIDERED AS WELL. HIGH WAVES WOULD REMAIN
TOWARD AND OVER THE OPEN WATERS.
&&
.PREV DISCUSSION... /ISSUED 511 AM CST THU NOV 21 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
CURRENT LULL IN PCPN SHOULD CONTINUE UNTIL LATE THIS AFTERNOON WITH
APPROACH OF FORCING WITH NEXT SHORT WAVE. LIGHT FOG WILL CONTINUE
WITH LIGHT...MOIST SRLY LOW LEVEL FLOW AHEAD OF SURFACE TROUGH AXIS
UNTIL IT SAGS SOUTHEAST OF CWA AROUND MIDDAY. BLENDED TIMING HAS
PCPN MOVING IN LATE THIS AFTERNOON AND EARLY EVENING PER LAYER Q-
VECTOR CONVERGENCE...WITH THE MAJORITY OF QPF FALLING BETWEEN 03Z
AND 09Z FRIDAY WITH STRONGER 850-700 MB FRONTOGENESIS. TEMPS WARM
ENOUGH FOR ALL RAIN TO START...THEN RAIN WILL MIX AND CHANGE OVER TO
SNOW WITH COLLAPSE OF COLUMN TEMPS ON FORECAST SOUNDINGS OVERNIGHT.
LOW QPF AMOUNTS WILL HOLD SNOW TOTALS IN THE NW TO AROUND 1
INCH...WHILE SE WILL ONLY SEE A DUSTING TO A FEW TENTHS OF AN INCH
WITH LATER TURNOVER.
MODELS KEEP 925 MB TEMPS AT/ABOVE 0C UNTIL 00Z FRI...WITH NAM FCST
SOUNDINGS SHOWING MIXING UP TO THESE 925 MB TEMPS WHILE GFS AND
ECMWF DO NOT MIX AS DEEP. WITH WARM OVERNIGHT TEMPERATURES WILL
FOLLOW CONSENSUS TEMPS THAT BRING HIGHS INTO THE LOW TO MID 40S.
THESE SHOULD BE REACHED BY EARLY AFTERNOON...THEN STEADY OR SLOWLY
COOL WITH NORTHWEST WINDS BEHIND PASSAGE OF TROUGH. SLOW COOLING
THROUGH THE EVENING ACCELERATES WITH COLD ADVECTION DROPPING 925 MB
TEMPS COOL TO -3C TO -7C BY 12Z FRIDAY.
FRIDAY - CONFIDENCE...MEDIUM 500 MILLIBAR SHORTWAVE SHIFTS EAST
DURING THE AFTERNOON. THE NAM IS A BIT MORE GENEROUS LINGERING LIGHT
QPF IN THE MORNING WHILE THE GFS AND ECMWF SHOW JUST A HINT IN THE
FAR SE CORNER. 700 WAVE WHISKS EAST FAIRLY QUICK THOUGH STILL A
DECENT FRONTOGENETICAL BAND LINGERING SO WILL KEEP SOME POPS DURING
THE MORNING. AIRMASS COLD ENOUGH FOR ALL SNOW PER BUFKIT SOUNDING
PROFILE. DRIER AIR STARTS TO WORK IN DURING THE AFTERNOON...WITH
SOME AREAS POSSIBLY SEEING SOME SUN BEFORE NOONTIME. BUFKIT/MOS/LOW
LEVEL RH PROGS ALL SUGGESTING THIS SO WILL TREND THE SKY
GRIDS IN THIS DIRECTION.
FRIDAY NIGHT AND SATURDAY - CONFIDENCE...MEDIUM COLD FRONT
ARRIVES WITH 850 TEMPS PLUNGING FROM AROUND -5C EARLY FRIDAY
EVENING TO AROUND -15 TO -18C SATURDAY MORNING. 925 TEMPS AROUND
-11 TO -13C WITH BLUSTERY CONDITIONS. SO TEMPS WILL STRUGGLE IN
THE 20S SATURDAY. UPPER FLOW IS STILL STRONGLY CYCLONIC THOUGH
AIRMASS PROGGED TO BE VERY DRY.
SATURDAY NIGHT AND SUNDAY - CONFIDENCE... VERY COLD AIRMASS IN
PLACE. 925 TEMPS AVERAGING -14C. WINDS EXPECTED TO DROP OFF ESP IN
SC WI WHERE SFC RIDGE AXIS NUDGES IN WITH TIME. SINGLE DIGIT TEMPS
QUITE LIKELY IN THESE AREAS. RIDGE AXIS SHIFTS EAST LATER ON SUNDAY
ALLOWING FOR EASTWARD DISPLACEMENT OF LOW LEVEL THERMAL TROUGH.
TEMPS WILL ONCE AGAIN STRUGGLE INTO THE 20S FOR DAYTIME HIGHS.
SUNDAY NIGHT AND MONDAY - CONFIDENCE...MEDIUM GFS/ECMWF SHOWING
PRECIP DEVELOPMENT WITH SURFACE/850 FRONTS. SOME RIGHT ENTRANCE
REGION JET DYNAMICS AT PLAY AS WELL. 1000-500 MILLIBAR THICKNESSES
BORDERLINE THOUGH BUFKIT SOUNDINGS...850/925 TEMPS PRETTY SUPPORTIVE
OF ALL SNOW. ECMWF A BIT MORE ROBUST WITH QPF AMOUNTS IN THE SE
BETWEEN 12-18Z MONDAY SHOWING OVER 0.10 LIQUID. POPS MAY NEED TO BE
RAISED IF MODEL CONSISTENCY/CONSENSUS BECOMES ESTABLISHED.
TUESDAY AND WEDNESDAY - CONFIDENCE...MEDIUM COLD AIRMASS GETS
REINFORCED ON THE ECMWF WITH ANOTHER COLD TROUGH BEING CARVED OUT
ACROSS THE WESTERN LAKES...WHILE THE GFS KEEPS THIS FURTHER NORTH
WHILE THE GFS HAS MORE OF A GLANCING SHOT OF THIS FURTHER NORTH. SO
A DISCREPANCY EXISTS WITH THE THERMAL FIELDS DURING THIS PERIOD.
LEANED ON THE ALLBLEND AT THIS POINT.
AVIATION/12Z TAFS/...
CURRENT MVFR VSBYS AND CEILINGS WILL LINGER THROUGH MOST OF THE DAY
..EXCEPT AT EASTERN TAF SITES WHERE TEMPS HAVE HELD UP WITH FLOW
OFF OF RELATIVELY WARMER LAKE. THESE LOCATIONS ARE EXPECTED TO DIP
TO MVFR LEVELS LATER THIS MORNING INTO THE AFTERNOON AS TEMPS COOL
WITH WINDS BECOME LIGHT WESTERLY...THEN NORTHWEST AS SURFACE TROUGH
SAG SOUTH. NEXT SHORT WAVE BRINGS CHC OF PCPN INTO SRN WI AROUND
21Z...WITH STEADY LIGHT PCPN BY MID-EVENING. WILL START OUT AS
RAIN...THEN MIX WITH SNOW AT KMSN BY 04Z...AND EASTERN SITES AROUND
MIDNIGHT.
KMSN WILL GO OVER TO ALL LIGHT SNOW BY MIDNIGHT...WITH SNOW TOTALS
AROUND 1/2 INCH. KENW AND KMKE WILL STAY MIXY UNTIL 09Z..THEN ALL
LIGHT SNOW. LATE TURNOVER WILL LIMIT ACCUMULATIONS TO A FEW TENTHS
OF AN INCH...MAINLY ON GRASSY AREAS. WILL SEE OCCASIONAL IFR VSBYS
DURING THE PERIOD OF STEADY LIGHT PCPN.
MARINE...
SMALL CRAFT ADVISORY ALLOWED TO EXPIRE AS WINDS AND WAVES HAD
SUBSIDED BY 10Z. ISSUED ANOTHER ADVISORY FOR LATE TONIGHT THROUGH
FRIDAY NIGHT AS NORTH WINDS INCREASE BEHIND SURFACE TROUGH TONIGHT
WITH THE LONG FETCH BUILDING WAVES TO 3 TO 6 FEET BY FRIDAY MORNING.
WINDS EASE FOR A TIME FRIDAY AFTERNOON AS SURFACE RIDGE PASSES
THROUGH...THEN INCREASE AGAIN FROM THE WEST BACK TO SMALL CRAFT
LEVELS. TIME PERIOD WAS TOO SHORT TO BREAK HEADLINE.
CURRENT END TIME REFLECTS POTENTIAL FOR GALES SATURDAY...BUT TOO
MUCH UNCERTAINTY TO ISSUE A WATCH. IF LATER FORECASTS DO NOT SUPPORT
A GALE HEADLINE...THEN CURRENT ADVISORY WILL HAVE TO BE EXTENDED AS
CURRENT FORECAST WINDS STAY UP INTO SUNDAY MORNING.
WINDS AND WAVES MAY REACH SMALL CRAFT ADVISORY LEVELS AT TIMES
EARLY NEXT WEEK...AS GUSTY OFFSHORE WINDS ARE EXPECTED AS LOW
PRESSURE PASSES THOUGH NORTH OF LAKE SUPERIOR. HIGH WAVES TOWARD THE
OPEN WATERS ARE POSSIBLE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO 6 AM CST SATURDAY FOR
LMZ643>646.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...COLLAR